WorldWideScience

Sample records for cubr gamma modification

  1. Electrical conductivity studies on CuBr containing Al2O3 particles

    Science.gov (United States)

    Dubec, P. M.; Wagner, J. B., Jr.

    1984-01-01

    The conductivity of CuBr was studied and the role of a second phase, Al2O3, dispersed in CuBr was tested. CuBr melts at 493 C and exhibits three phases in the solid state. CuBr is a good ionic conductor with a transport number for copper ions of virtually unity with weighed proportions of the appropriate chemicals used. The CuBr materials were heated above melting point of CuBr, and the samples were sandwiched between copper electrodes. The ac conductivity, was determined at 1 kHz between 25 and 440 C depending on the sample. It was shown that at low temperatures, the conductivity for CuBr (Al2O3) increased by as much as 100, whereas in the beta phase the conductivity of CuBr containing Al2O3 decreased. The electrical conductivity studies are in agreement with earlier data.

  2. O-GlcNAc modification of PPAR{gamma} reduces its transcriptional activity

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Suena; Park, Sang Yoon [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Roth, Juergen [Department of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Hoe Suk, E-mail: hoeskim@snu.ac.kr [Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of); Cho, Jin Won, E-mail: chojw311@yonsei.ac.kr [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer We found that PPAR{gamma} is modified by O-GlcNAc in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer The Thr54 of PPAR{gamma}1 is the major O-GlcNAc site. Black-Right-Pointing-Pointer Transcriptional activity of PPAR{gamma}1 was decreased on treatment with the OGA inhibitor. -- Abstract: The peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), a member of the nuclear receptor superfamily, is a key regulator of adipogenesis and is important for the homeostasis of the adipose tissue. The {beta}-O-linked N-acetylglucosamine (O-GlcNAc) modification, a posttranslational modification on various nuclear and cytoplasmic proteins, is involved in the regulation of protein function. Here, we report that PPAR{gamma} is modified by O-GlcNAc in 3T3-L1 adipocytes. Mass spectrometric analysis and mutant studies revealed that the threonine 54 of the N-terminal AF-1 domain of PPAR{gamma} is the major O-GlcNAc site. Transcriptional activity of wild type PPAR{gamma} was decreased 30% by treatment with the specific O-GlcNAcase (OGA) inhibitor, but the T54A mutant of PPAR{gamma} did not respond to inhibitor treatment. In 3T3-L1 cells, an increase in O-GlcNAc modification by OGA inhibitor reduced PPAR{gamma} transcriptional activity and terminal adipocyte differentiation. Our results suggest that the O-GlcNAc state of PPAR{gamma} influences its transcriptional activity and is involved in adipocyte differentiation.

  3. Modification of ethylene-norbornene copolymer by Gamma irradiation

    Directory of Open Access Journals (Sweden)

    Kačarević-Popović Zorica M.

    2006-01-01

    Full Text Available The possibility of modifying polyethylene and many other polymers with high energy radiation has led to many useful applications. Due to their new combination of properties and the shortage of experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC, polymerised from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and the physics of polymeric systems. Ethylenenorbornene copolymer, pristine and containing an antioxidant were subjected to gamma irradiation in the presence of air and in water. The irradiated copolymer was studied using IR and UV-vis spectrophotometric analysis. The radiation-induced changes in the molecular structure were correlated to changes in the glass transition temperature measured by the DSC method.

  4. Improvement of plant parameters of the ROBO gamma irradiation facility due to design modification

    Science.gov (United States)

    Kovacs, A.; Moussa, A.; Othman, I.; Del Valle Odar, C.; Seminario, A.; Linares, M.; Huamanlazo, P.; Aymar, J.; Chu, R.

    1998-06-01

    Two industrial scale, "ROBO" type 60Co gamma irradiation facilities have recently been put into operation in Syria and Peru, and the dosimetry commissioning of both plants have been carried out to determine dose distribution within products and to calculate plant parameters such as efficiency, dose uniformity ratio and throughput. There are some design modifications between the two plants in connection with the location of the carriers with respect to the source plaque and also to each other. The effect of these construction modifications on the plant parameters is discussed in the analysis of the dose distribution data measured in the carriers with depth and height among the four irradiation rows on both sides of the source plaque. The plant parameters were also calculated for different product densities using the technical data of the facilities, and the calculated and measured results were compared to each other.

  5. Surface modification of biomaterials by pulsed laser ablation deposition and plasma/gamma polymerization

    Science.gov (United States)

    Rau, Kaustubh R.

    Surface modification of stainless-steel was carried out by two different methods: pulsed laser ablation deposition (PLAD) and a combined plasma/gamma process. A potential application was the surface modification of endovascular stents, to enhance biocompatibility. The pulsed laser ablation deposition process, had not been previously reported for modifying stents and represented a unique and potentially important method for surface modification of biomaterials. Polydimethylsiloxane (PDMS) elatomer was studied using the PLAD technique. Cross- linked PDMS was deemed important because of its general use for biomedical implants and devices as well as in other fields. Furthermore, PDMS deposition using PLAD had not been previously studied and any information gained on its ablation characteristics could be important scientifically and technologically. The studies reported here showed that the deposited silicone film properties had a dependence on the laser energy density incident on the target. Smooth, hydrophobic, silicone-like films were deposited at low energy densities (100-150 mJ/cm2). At high energy densities (>200 mJ/cm2), the films had an higher oxygen content than PDMS, were hydrophilic and tended to show a more particulate morphology. It was also determined that (1)the deposited films were stable and extremely adherent to the substrate, (2)silicone deposition exhibited an `incubation effect' which led to the film properties changing with laser pulse number and (3)films deposited under high vacuum were similar to films deposited at low vacuum levels. The mechanical properties of the PLAD films were determined by nanomechanical measurements which are based on the Atomic Force Microscope (AFM). From these measurements, it was possible to determine the modulus of the films and also study their scratch resistance. Such measurement techniques represent a significant advance over current state-of-the-art thin film characterization methods. An empirical model for

  6. Modifications in structural and electrical properties of gamma irradiated CdSe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Manju, E-mail: manjuyadav.jnv@gmail.com; Rana, Pallavi, E-mail: prana.phy@gmail.com; Chauhan, R.P., E-mail: chauhanrpc@gmail.com

    2014-07-01

    Semiconducting nanowires have gained huge interest of researchers due to their interesting properties and potential application in the field of nanoelectronics and optoelectronics. Present study reports the effect of gamma (γ) irradiation on structural and electrical properties of CdSe nanowires. These nanowires were synthesized by a template assisted electrodeposition method which provides uniform and standing nanowires of cylindrical shape. These synthesized nanowires were exposed to gamma rays using a {sup 60}Co source. Before and after irradiation, the nanowires were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray (EDX) and Keithley 2400 series source meter to study their structural and electrical properties. XRD patterns of irradiated samples showed increase in grain size with radiation dose and increase in the peak intensity was observed corresponding to different planes of hexagonal CdSe structure. SEM images confirmed the cylindrical morphology of nanowires and EDX analysis revealed the stoichiometric formation of CdSe. The electrical properties from I–V characteristics showed an enhancement in the electrical conductivity of the nanowires with radiation dose and applied potential. This modification in electrical conductivity may be attributed to decrease in grain boundary scattering of charge carriers. - Highlights: • CdSe nanowires were synthesized via the template-assisted electrodeposition method. • Synthesized nanowires were irradiated with gamma rays using {sup 60}Co source. • In XRD spectra, no shifting was observed in 2θ position of peaks with irradiation. • An enhancement in the electrical conductivity observed with radiation and potential.

  7. Modifications of a method for low energy gamma-ray incident angle reconstruction in the GAMMA-400 gamma-ray telescope

    Science.gov (United States)

    Leonov, A. A.; Galper, A. M.; Topchiev, N. P.; Bonvicini, V.; Adriani, O.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Bakaldin, A. V.; Bobkov, S. G.; Boezio, M.; Dalkarov, O. D.; Egorov, A. E.; Glushkov, N. A.; Gorbunov, M. S.; Gusakov, Yu V.; Hnatyk, B. I.; Kadilin, V. V.; Kaplin, V. A.; Kheymits, M. D.; Korepanov, V. E.; Longo, F.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Moskalenko, I. V.; Naumov, P. Yu; Picozza, P.; Runtso, M. F.; Serdin, O. V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu I.; Suchkov, S. I.; Taraskin, A. A.; Tavani, M.; Yurkin, Yu T.; Zverev, V. G.

    2017-01-01

    The GAMMA-400 gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to ∼1 TeV, performing a sensitive search for high-energy gamma-ray emission when annihilating or decaying dark matter particles. Such measurements will be also associated with the following scientific goals: searching for new and studying known Galactic and extragalactic discrete high-energy gamma-ray sources (supernova remnants, pulsars, accreting objects, microquasars, active galactic nuclei, blazars, quasars). It will be possible to study their structure with high angular resolution and measuring their energy spectra and luminosity with high-energy resolution; identify discrete gamma-ray sources with known sources in other energy ranges. The major advantage of the GAMMA-400 instrument is excellent angular and energy resolutions for gamma rays above 10 GeV. The gamma-ray telescope angular and energy resolutions for the main aperture at 100-GeV gamma rays are ∼0.01% and ∼1%, respectively. The motivation of presented results is to improve physical characteristics of the GAMMA-400 gamma-ray telescope in the energy range of ∼20-100 MeV, most unexplored range today. Such observations are crucial today for a number of high-priority problems faced by modern astrophysics and fundamental physics, including the origin of chemical elements and cosmic rays, the nature of dark matter, and the applicability range of the fundamental laws of physics. To improve the reconstruction accuracy of incident angle for low-energy gamma rays the special analysis of topology of pair-conversion events in thin layers of converter performed. Choosing the pair-conversion events with more precise vertical localization allows us to obtain significantly better angular resolution in comparison with previous and current space and ground-based experiments. For 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is better than 50.

  8. Modifications in structural, cation distribution and magnetic properties of {sup 60}Co gamma irradiated Li-ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Mane, Maheshkumar L. [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India); Shirsath, Sagar E., E-mail: shirsathsagar@hotmail.com [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India); Dhage, Vinod N.; Jadhav, K.M. [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India)

    2011-09-15

    Highlights: {yields} Gamma irradiation induced defects in lithium ferrite. {yields} Modifications in structural and magnetic properties. {yields} Fe{sup 3+} changes to Fe{sup 2+} after gamma irradiation. - Abstract: Polycrystalline samples of Li{sub 0.5}Fe{sub 2.5}O{sub 4} ferrite precursor were prepared by conventional standard double sintering ceramic technique and then irradiated with three different doses of {sup 60}Co gamma rays. The crystal structure and phase orientation of the irradiated and unirradiated samples of Li{sub 0.5}Fe{sub 2.5}O{sub 4} ferrite was done by using X-ray diffraction technique at room temperature. The lattice parameter of the studied samples increased due to the formation of Fe{sup 2+} ions under the ionizing effect of gamma radiation. The strain in the materials due to the irradiation was calculated from XRD data. Scanning electron microscope (SEM) studies indicate that the irradiation causes amorphization, especially at the grain boundaries. The cation distribution was calculated from XRD data analysis. By using cation distribution structural parameters such as theoretical lattice constant, ionic radii of available sites and the oxygen parameter 'u' have been calculated. The estimated cation distribution and other structural parameters shows strong influence of gamma rays on polycrystalline Li-ferrite. The magnetic properties of irradiated and unirradiated lithium ferrite were performed by using pulse field hysteresis loop technique at room temperature. Electrical properties such as diffusion coefficient and dielectric properties were carried out with the influence of gamma irradiation. Activation energy of diffusion process decreased after irradiation. The increase of diffusion coefficient with increasing dose rate of gamma irradiation was reinforced by the increase of Fe{sup 2+} ions and the displacement of metal ions from its original sites under the effect of gamma irradiation.

  9. Modulation of Radio-response by the Modification and Stabilization of c-Myc by IKK{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bu Yeon; Han, Young Hoon [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-05-15

    The transcription factor c-Myc plays a critical role in multiple cellular processes including cell cycle progression, proliferation, differentiation, and apoptosis. The expression of c-Myc is generally upregulated in most of human cancers during tumor progression. Correct regulation of c-Myc accumulation is thus essential, and achieved by multiple mechanisms acting at different stages of protein expression including the regulation of transcription, mRNA stability, translation, and protein stability. Various mechanisms have been reported to regulate the stability of c-Myc. IKK{gamma} is a critical component for the activity of IKK complex, which is essential for NF-{kappa}B activation in response to a variety of stress stimuli. Besides the cytoplasmic role of IKK{gamma} in regulating the activity of IKK complex, IKK{gamma} was shown to shuttle between cytoplasm and nucleus and play a nuclear role in transcriptional repression of the NF-{kappa}B pathway. Here, we report that IKK{gamma} stabilizes c-Myc protein through direct interaction and the stabilization and possible modification of c-Myc by IKK{gamma} modulates the cellular response to ionizing radiation.

  10. Multiple {gamma}-glutamylation: A novel type of post-translational modification in a diapausing Artemia cyst protein

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Mai [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Ikeda, Yuka [Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda 386-8567 (Japan); Kanzawa, Hideaki [Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Sakamoto, Mika [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Goto, Mina [Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Tsunasawa, Susumu [Analytical and Measuring Instruments Division, Shimadzu Corporation, Nishinokyo Kuwabaracho 1, Nakagyo-Ku, Kyoto 604-8511 (Japan); Uchiumi, Toshio, E-mail: uchiumi@bio.sc.niigata-u.ac.jp [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Odani, Shoji [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan)

    2010-03-26

    A highly hydrophilic, glutamate-rich protein was identified in the aqueous phenol extract from the cytosolic fraction of brine shrimp (Artemia franciscana) diapausing cysts and termed Artemia phenol soluble protein (PSP). Mass spectrometric analysis revealed the presence of many protein peaks around m/z 11,000, separated by 129 atomic mass units; this value corresponds to that of glutamate, which is strongly suggestive of heterogeneous polyglutamylation. Polyglutamylation has long been known as the functionally important post-translational modification of tubulins, which carry poly(L-glutamic acid) chains of heterogeneous length branching off from the main chain at the {gamma}-carboxy groups of a few specific glutamate residues. In Artemia PSP, however, Edman degradation of enzymatic peptides revealed that at least 13, and presumably 16, glutamate residues were modified by the attachment of a single L-glutamate, representing a hitherto undescribed type of post-translational modification: namely, multiple {gamma}-glutamylation or the addition of a large number of glutamate residues along the polypeptide chain. Although biological significance of PSP and its modification is yet to be established, suppression of in vitro thermal aggregation of lactate dehydrogenase by glutamylated PSP was observed.

  11. Structural, chemical surface and transport modifications of regenerated cellulose dense membranes due to low-dose {gamma}-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.I. [Grupo de Caracterizacion Electrocinetica en Membranas e Interfases, Departamento de Fisica Aplicada I, Facultad de Ciencias, Universidad de Malaga, E-29071 Malaga (Spain); Heredia-Guerrero, J.A., E-mail: jose.alejandro@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, Avda, Americo Vespuccio 49, 41092 Sevilla (Spain); Galan, P. [Grupo de Caracterizacion Electrocinetica en Membranas e Interfases, Departamento de Fisica Aplicada I, Facultad de Ciencias, Universidad de Malaga, E-29071 Malaga (Spain); Benitez, J.J. [Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, Avda, Americo Vespuccio 49, 41092 Sevilla (Spain); Benavente, J. [Grupo de Caracterizacion Electrocinetica en Membranas e Interfases, Departamento de Fisica Aplicada I, Facultad de Ciencias, Universidad de Malaga, E-29071 Malaga (Spain)

    2011-04-15

    Research highlights: {yields} Low dose {gamma}-radiation causes slight structural, chemical and morphological changes on regenerated cellulose films. {yields} Induced structural changes increase the fragility of irradiated films. {yields} Structural modifications reduce ion permeability of films. - Abstract: Modifications caused in commercial dense regenerated cellulose (RC) flat membranes by low-dose {gamma}-irradiation (average photons energy of 1.23 MeV) are studied. Slight structural, chemical and morphological surface changes due to irradiation in three films with different RC content were determined by ATR-FTIR, XRD, XPS and AFM. Also, the alteration of their mechanical elasticity has been studied. Modification of membrane performance was determined from solute diffusion coefficient and effective membrane fixed charge concentration obtained from NaCl diffusion measurements. Induced structural changes defining new and effective fracture propagation directions are considered to be responsible for the increase of fragility of irradiated RC membranes. The same structural changes are proposed to explain the reduction of the membrane ion permeability through a mechanism involving either ion pathways elongation and/or blocking.

  12. [Oxidation of mercury by CuBr2 decomposition under controlled-release membrane catalysis condition].

    Science.gov (United States)

    Hu, Lin-Gang; Qu, Zan; Yan, Nai-Qiang; Guo, Yong-Fu; Xie, Jiang-Kun; Jia, Jin-Ping

    2014-02-01

    CuBr2 in the multi-porous ceramic membrane can release Br2 at high temperature, which was employed as the oxidant for Hg0 oxidation. Hg0 oxidation efficiency was studied by a membrane catalysis device. Meanwhile, a reaction and in situ monitoring device was designed to avoid the impact of Br2 on the downstream pipe. The result showed that the MnO(x)/alpha-Al2O3 catalysis membrane had a considerable "controlled-release" effect on Br2 produced by CuBr2 decomposition. The adsorption and reaction of Hg0 and Br2 on the surface of catalysis membrane obeyed the Langmuir-Hinshelwood mechanism. The removal efficiency of Hg0 increased with the rising of Br2 concentration. However, when Br2 reached a certain concentration, the removal efficiency was limited by adsorption rate and reaction rate of Hg0 and Br2 on the catalysis membrane. From 473 K to 573 K, the variation of Hg0 oxidation efficiency was relatively stable. SO2 in flue gas inhibited the oxidation of Hg0 while NO displayed no obvious effect.

  13. Gamma irradiation-induced modifications of resins found in nuclear waste embedding processes; Modifications induites par irradiation gamma dans les differentes resines rencontrees dans le traitement des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Allali, H. [Faculte des Science et Techniques, Settat (Morocco); Debre, O.; Lambert, M.; Nsouli, B.; Thomas, J.P. [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France); Collaboration: IPN-Lyon, Laboratoire d`Etude des Materiaux Plastiques et des Biomateriaux, URA 507, UCBL, Agence Nationale pour la Gestion des Dechets Radiactifs

    1998-12-31

    The various resins involved in nuclear waste disposal are subject to gamma irradiation-induced modifications. From Time-of-Flight Mass Spectrometry of Secondary ions emitted under High Energy Projectiles bombardment (HSF-SIMS) of such materials the following results are obtained: the embedding epoxy resin DGEBA-DDM does not exhibit significant bulk changes in chemical structure, whatever the dose rate and irradiation medium (air or water), at least up to 2 MGy. However, oxidation processes are well observed at the very surface. Under the same conditions Ion exchange resins to be embedded are subjected to scissions of their functional sites, leading to fixed ion release. Dehydration under irradiation is observed pointing out the crucial role of water in ion transport outside of the material. (authors)

  14. Modification of silicone sealant to improve gamma radiation resistance, by addition of protective agents

    Science.gov (United States)

    González-Pérez, Giovanni; Burillo, Guillermina

    2013-09-01

    Poly (dimethylsiloxane) (PDMS) sealant (SS) was modified with the addition of different protective compounds to conserve its physical-chemical properties during gamma irradiation. 2-Vinyl naphthalene (2-VN), bisphenol-A (BPA) and poly (vinyl carbazole) (PVK) were used to evaluate radiation protection through the crosslinking effect of radiation. The samples were irradiated with doses from 100 kGy to 500 kGy at room temperature in air, with a 60Co gamma source, and the changes in molecular weight, thermal behavior, elastic properties and infrared spectra (FTIR-ATR) absorbance analysis were determined. The molecular weight of unmodified silicone sealant increases with the absorbed dose because of crosslinking as predominant effect. However, the crosslinking effect was inhibited with the addition of protective agent due to the aromatic compounds present. Modified silicone sealant films present better radiation resistance than unmodified system.

  15. Field-controlled magnetic order in the quantum spin-ladder system (Hpip)2CuBr4

    DEFF Research Database (Denmark)

    Thielemann, B.; Rüegg, C.; Kiefer, K.

    2009-01-01

    Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)(2)CuBr4. This "classical" phase, a consequence of weak interladder coupling, is nevertheless highly unconventional: its properties are influenced strongly b...

  16. Gamma-irradiation effects to posttranslational modification and chaperon function of bovine {alpha}-crystalline

    Energy Technology Data Exchange (ETDEWEB)

    Hiroki, K; Matsumoto, S.; Awakura, M. [Kyoto Univ., Graduate School of Science, Kyoto (Japan); Fujii, N. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    2001-01-01

    The formation of D-asparate (D-Asp) in {alpha}A-crystallin of the aged human eye and the cataract crystalline lens has been reported. Crystalline lens keeps the transparency by forming {alpha}-crystallin which consists of a high order association of {alpha}A-and {alpha}B-crystallin. Bovine {alpha}-crystallin for investigating a chaperone function which protects the crystalline lens from getting to opaque or disordered agglutination with heat or light, is irradiated by gamma-ray (Co-60) at 0, 1, 2, 3, and 4 kGy, respectively. The irradiated bovine {alpha}-crystallin are analyzed with electrophoresis, gel permeation chromatograph, and UV absorption spectrometer for checking on the agglutination and the isomerization of macromolecules. Oxidation of methionine residues (Met-1) and isomerization of asparagine residues (Asp-151) in the {alpha}A-crystallin are ascertained in molecular levels with reversed phase liquid chromatography. The Met-1 oxidation and the Asp-151 isomerization depend on gamma-irradiation doses. It is thought that OH radical and H radical in water generated by the irradiation lead to the oxidation and the isomerization. Stereoinversion in the {alpha}-crystallin following to such a chemical change are considered to lead to the agglutination of polymer and the reduction of chaperon function. (M. Suetake)

  17. Comparison of gamma- and beta radiation stress responses on anti-oxidative defense system and DNA modifications in Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoeck, Arne [SCK.CEN, Boeretang 200 2400 Mol (Belgium); University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Horemans, Nele; Van Hees, May; Nauts, Robin; Vandenhove, Hildegarde [SCK.CEN, Boeretang 200 2400 Mol (Belgium); Knapen, Dries; Blust, Ronny [University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

    2014-07-01

    frond have been implemented in a dosimetric model derived from ERICA tool. This enabled a reliable comparison of dose-dependent endpoints between gamma- and beta radiation. Dose rates varied from 15 and 1500 mGy/hr, and 19 from 19000 μGy/hr for gamma- and beta radiation respectively. The classic growth related endpoints, like biomass and frond area, were measured and compared with biochemical and molecular endpoints. Therefore, DNA modifications were analyzed to evaluate biological DNA damage and ROS accumulation in plants together with activities of anti-oxidative enzymes to evaluate oxidative stress response. A dose-response curve with 60 percent growth inhibition was determined for gamma radiation and morphological growth effects in root system were observed for beta radiation. Preliminary results showed similar responses in peroxidase activities between both radiation types. These results and ongoing investigations will help to unravel the differences and similarities in response mechanisms for various radiation types in plant systems. As multiple levels in biological organisation of the organism were considered, and also different dose rates taken into account, this approach allows a better understanding the toxic mode of action of radiation stress in higher plants. This research was supported by the European Commission Contract Fission-2010-3.5.1-269672 to Strategy for Allied Radioecology (www.star-radioecology.org) and a project of the Fund for Scientific Research (FWO-Vlaanderen, G.A040.11N) (authors)

  18. Influence of radiation dose distribution in radiobiological modifications after Gamma Knife radiosurgery

    OpenAIRE

    Massager, Nicolas

    2008-01-01

    La radiochirurgie par Gamma Knife constitue une modalité thérapeutique reconnue de certaines affections cérébrales. Le traitement se base sur l’administration d’un rayonnement focalisé au niveau d’une cible intracrânienne. L’efficacité de ce traitement repose sur la délivrance d’une dose d’irradiation efficace au sein d’un volume-cible associé à la délivrance d’une dose d’irradiation négligeable à l’extérieur de ce même volume-cible. En pratique, la dose d’irradiation administrée à l’intérieu...

  19. Surface modification by {gamma}-ray-induced grafting of PDMAEMA/PEGMEMA onto PE films

    Energy Technology Data Exchange (ETDEWEB)

    Titaux, G.A. [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Contreras-Garcia, A. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: ebucio@nucleares.unam.mx

    2009-07-15

    Radiation grafting of poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) onto polyethylene (PE) films was synthesized using gamma radiation from a {sup 60}Co source. PE was modified by the PDMAEMA and PEGMEMA by pre-irradiation and one-step method. Grafting as a function of the pre-irradiation dose between 50 and 200 kGy, dose rate of 9 kGy h{sup -1}, and monomer concentration 50% of PDMAEMA/PEGMEMA (1/1) in toluene. The characterization of the graft copolymer obtained was carried out by FTIR-ATR, TGA, and DSC. Stimuli-responsive behavior and critical pH point were studied by swelling in water, pH and thermo-responsive films of PE-g-(DMAEMA/PEGMEMA) presented a lower critical solution temperature (LCST) of 55 deg. C and critical pH point around 8.5.

  20. Shifting Phases for Patchy Particles - Effect of mutagenesis and chemical modification on the phase diagram of human gamma D crystallin

    Science.gov (United States)

    McManus, Jennifer J.; James, Susan; McNamara, Ruth; Quinn, Michelle

    2014-03-01

    Single mutations in human gamma D crystallin (HGD), a protein found in the eye lens are associated with several childhood cataracts. Phase diagrams for several of these protein mutants have been measured and reveal that phase boundaries are shifted compared with the native protein, leading to condensation of protein in a physiologically relevant regime. Using HGD as a model protein, we have constructed phase diagrams for double mutants of the protein, incorporating two single amino acid substitutions for which phase diagrams are already known. In doing so, the characteristics of each of the single mutations are maintained but both are now present in the same protein particle. While these proteins are not of interest physiologically, this strategy allows the controlled synthesis of nano-scale patchy particles in which features associated with a known phase behavior can be included. It can also provide a strategy for the controlled crystallisation of proteins. Phase boundaries also change after the chemical modification of the protein, through the covalent attachment of fluorescent labels, for example, and this will also be discussed. The authors acknowledge Science Foundation Ireland Stokes Lectureship and Grant 11/RFP.1/PHY/3165. The authors also acknowledge the Irish Research Council and the John and Pat Hume Scholarship.

  1. Bone embrittlement and collagen modifications due to high-dose gamma-irradiation sterilization.

    Science.gov (United States)

    Burton, Brianne; Gaspar, Anne; Josey, David; Tupy, Jindra; Grynpas, Marc D; Willett, Thomas L

    2014-04-01

    DSC, there was a 20% decrease in thermal stability (pmelting). HIT testing also showed a decrease in thermal stability (20% lower denaturation temperature, pmelt), perhaps a result of alterations in the hydrogen bonding sites (increased carbonyl content detected in the insoluble collagen) on the irradiated bone collagen. Altogether, this new data strongly indicates that a large loss of overall collagen connectivity due to collagen fragmentation resulting from γ-irradiation sterilization leads to inferior cortical bone toughness. In addition, notable changes in the thermal denaturation of the bone collagen along with chemical indicators of oxidative modification of the bone collagen indicate that the embrittlement may be a function not only of collagen fragmentation but also of changes in bonding. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Photoluminescence characteristics of polariton condensation in a CuBr microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Masaaki, E-mail: nakayama@a-phys.eng.osaka-cu.ac.jp; Murakami, Katsuya; Furukawa, Yoshiaki; Kim, DaeGwi [Department of Applied Physics, Graduate School of Engineering, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan)

    2014-07-14

    We have investigated the photoluminescence (PL) properties of a CuBr microcavity at 10 K, including the temporal profiles, from the viewpoint of cavity-polariton condensation. The excitation energy density dependence of the PL intensity (band width) of the lower polariton branch at an in-plane wave vector of k{sub //} = 0 exhibits a threshold-like increase (decrease). A large blueshift in the PL energy of ∼10 meV caused by the cavity-polariton renormalization is correlated with the excitation energy density dependence of the PL intensity. The estimated density of photogenerated electron-hole pairs at the threshold is two orders lower than the Mott transition density. These results consistently demonstrate the occurrence of cavity-polariton condensation. In addition, we found that the PL rise and decay times are shortened dramatically by the cavity-polariton condensation, which reflects the bosonic final state stimulation in the relaxation process and the intrinsic cavity-polariton lifetime in the decay process.

  3. Modifications by {gamma} irradiation of polyethylene at very high molecular weight. Tribological behaviour for orthopedic applications; Modifications par irradiation {gamma} du polyethylene a tres haut poids moleculaire. Comportement tribologique pour des applications orthopediques

    Energy Technology Data Exchange (ETDEWEB)

    Chaix, N

    2001-07-01

    A new mode of sterilization by vacuum gamma irradiation is studied. This new mode improves significantly the polyethylene behaviour during the study in friction-corrosion against a stainless steel-316L sphere. (N.C.)

  4. Enhanced one-carbon flux towards DNA methylation: Effect of dietary methyl supplements against gamma-radiation-induced epigenetic modifications.

    Science.gov (United States)

    Batra, Vipen; Sridhar, Swathi; Devasagayam, Thomas Paul Asir

    2010-02-12

    Radiation exposure poses a major risk for workers in the nuclear power plants and other radiation related industry. In this context, we demonstrate that gamma-radiation is an efficient DNA demethylating agent and its injurious effect can be minimized by dietary methyl supplements (folate, choline and vitamin B12). To elucidate the possible underlying mechanism(s), male Swiss mice were maintained on normal control diet (NCD) and methyl-supplemented diet (MSD). After 2 weeks of NCD and MSD dietary regimen, we exposed the animals to gamma-radiation (2, 4 and 6Gy) and investigated the profile of downstream metabolites and activity levels of one-carbon (C(1)) flux generating enzymes. In MSD fed and irradiated animals, hepatic folate levels increased (Pmaintenance of genomic DNA methylation under gamma-radiation stress might be a very dynamic, progressive diet dependent process that could involve increased one-carbon flux through various C(1) metabolites.

  5. Spontaneous piezoelectric effect as order parameter in (NH4)2CuBr4·2H2O crystal

    Science.gov (United States)

    Tylczyński, Z.; Wiesner, M.; Trzaskowska, A.

    2016-11-01

    Temperature change of piezoelectric properties of (NH4)2CuBr4·2H2O crystal in the low-temperature ferroelastoelectric phase is studied. The macroscopic order parameter is proved to be the h36 component of the spontaneous piezoelectric tensor. The critical exponent related with the phase transition is α=0.60±0.05.

  6. Prenatal Dexamethasone and Postnatal High-Fat Diet Decrease Interferon Gamma Production through an Age-Dependent Histone Modification in Male Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Hong-Ren Yu

    2016-09-01

    Full Text Available Overexposure to prenatal glucocorticoid (GC disturbs hypothalamic-pituitary-adrenocortical axis-associated neuroendocrine metabolism and susceptibility to metabolic syndrome. A high-fat (HF diet is a major environmental factor that can cause metabolic syndrome. We aimed to investigate whether prenatal GC plus a postnatal HF diet could alter immune programming in rat offspring. Pregnant Sprague-Dawley rats were given intraperitoneal injections of dexamethasone or saline at 14–21 days of gestation. Male offspring were then divided into four groups: vehicle, prenatal dexamethasone exposure, postnatal HF diet (VHF, and prenatal dexamethasone exposure plus a postnatal HF diet (DHF. The rats were sacrificed and adaptive immune function was evaluated. Compared to the vehicle, the DHF group had lower interferon gamma (IFN-γ production by splenocytes at postnatal day 120. Decreases in H3K9 acetylation and H3K36me3 levels at the IFN-γ promoter correlated with decreased IFN-γ production. The impaired IFN-γ production and aberrant site-specific histone modification at the IFN-γ promoter by prenatal dexamethasone treatment plus a postnatal HF diet resulted in resilience at postnatal day 180. Prenatal dexamethasone and a postnatal HF diet decreased IFN-γ production through a site-specific and an age-dependent histone modification. These findings suggest a mechanism by which prenatal exposure to GC and a postnatal environment exert effects on fetal immunity programming.

  7. Prenatal Dexamethasone and Postnatal High-Fat Diet Decrease Interferon Gamma Production through an Age-Dependent Histone Modification in Male Sprague-Dawley Rats

    Science.gov (United States)

    Yu, Hong-Ren; Tain, You-Lin; Sheen, Jiunn-Ming; Tiao, Mao-Meng; Chen, Chih-Cheng; Kuo, Ho-Chang; Hung, Pi-Lien; Hsieh, Kai-Sheng; Huang, Li-Tung

    2016-01-01

    Overexposure to prenatal glucocorticoid (GC) disturbs hypothalamic-pituitary-adrenocortical axis-associated neuroendocrine metabolism and susceptibility to metabolic syndrome. A high-fat (HF) diet is a major environmental factor that can cause metabolic syndrome. We aimed to investigate whether prenatal GC plus a postnatal HF diet could alter immune programming in rat offspring. Pregnant Sprague-Dawley rats were given intraperitoneal injections of dexamethasone or saline at 14–21 days of gestation. Male offspring were then divided into four groups: vehicle, prenatal dexamethasone exposure, postnatal HF diet (VHF), and prenatal dexamethasone exposure plus a postnatal HF diet (DHF). The rats were sacrificed and adaptive immune function was evaluated. Compared to the vehicle, the DHF group had lower interferon gamma (IFN-γ) production by splenocytes at postnatal day 120. Decreases in H3K9 acetylation and H3K36me3 levels at the IFN-γ promoter correlated with decreased IFN-γ production. The impaired IFN-γ production and aberrant site-specific histone modification at the IFN-γ promoter by prenatal dexamethasone treatment plus a postnatal HF diet resulted in resilience at postnatal day 180. Prenatal dexamethasone and a postnatal HF diet decreased IFN-γ production through a site-specific and an age-dependent histone modification. These findings suggest a mechanism by which prenatal exposure to GC and a postnatal environment exert effects on fetal immunity programming. PMID:27669212

  8. Cotton fabric modification for imparting high water and oil repellency using perfluoroalkyl phosphate acrylate via gamma-ray-induced grafting

    Energy Technology Data Exchange (ETDEWEB)

    Miao Hui; Bao Fenfen; Cheng Liangliang [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China); Shi Wenfang, E-mail: wfshi@ustc.ed [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026 (China)

    2010-07-15

    The perfluoroalkyl phosphate acrylates were grafted onto a cotton fabric via gamma-ray irradiation to improve the hydrophobic and oleophobic properties. The change in chemical structure of grafted cotton fabric was detected by the Fourier transform infrared spectroscopy and the X-ray photoelectron spectroscopy. The contact angles for water and sunflower oil were determined to be over 150 deg. and 140 deg., respectively, after irradiated with a dose range of 471-5664 Gy. The flame retardancy of the fabric with a grafting ratio of over 13.0 wt% was improved, reaching to 24 compared with 18 of which before grafted, according to the limiting oxygen index measurement. The microstructure of the fabric before and after grafted was observed by the scanning electron microscope.

  9. Hysteresis effect of ammonium and water protons by 1H MAS NMR in (NH4)2CuBr4·2H2O

    Science.gov (United States)

    Lim, Ae Ran; Cho, Jiung

    2017-10-01

    The chemical shifts, linewidths, and spin-lattice relaxation times for ammonium and water protons in (NH4)2CuBr4·2H2O were investigated by 1H magic angle spinning nuclear magnetic resonance (MAS NMR) with a focus on the roles of NH4+ and H2O at high temperatures. The changes in the temperature dependence of the data near Td (=360 K) were related to variations of the H environments; the mechanism above Td was related to hydrogen-bond transfer involving breakage of the weak part of the hydrogen bond. The hysteresis effects for the ammonium and water protons in (NH4)2CuBr4·2H2O by MAS NMR were described with respect to heating and cooling.

  10. Modification of chemical, optical and structural properties of Bayfol CR-6-2 using gamma and neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, Mohamed M.; Radwan, Samh I.; Hassan, Amin [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Centre; Waly, Sayed A. [Atomic Energy Authority, Cairo (Egypt). Second Research Reactor; Badawy, Zaynab M. [Atomic Energy Authority, Cairo (Egypt). Experimental Nuclear Physics Dept.

    2016-08-01

    The effects of gamma and neutron irradiations on the chemical, optical and structural properties of Bayfol CR-6-2 were investigated. The samples were irradiated by γ-rays from a {sup 60}Co source at various doses ranging between 16 and 900 kGy at room temperature in atmospheric air. For neutrons, an Am-Be neutron facility was used for the sample irradiation in thermal mode which had an activity of 185 GBq. Samples were irradiated with different doses of neutrons ranging from 15.7 to 564.2 mGy. The changes induced were analyzed using UV-Vis and Fourier transform infrared (FTIR) spectrometry. The results demonstrated an occurrence of oxidative degradation, resulting in the formation of carbonyl groups at 1700 cm{sup -1}. Simultaneous thermo-gravimetric investigation (TGA) has been performed on the samples of 0.3 mm thickness. The results obtained indicate that cross-linking predominates at small neutron doses and main chain scission happens at higher doses.

  11. Quantum Monte Carlo simulation of antiferromagnetic spin ladder (C5H12N)2CuBr4

    Science.gov (United States)

    Freitas, Augusto S.

    2016-07-01

    In this paper I present a Quantum Monte Carlo (QMC) study of the magnetic properties of an antiferromagnetic spin ladder (C5H12N)2CuBr4. This compound is the prototype of the Heisenberg model for a two leg spin ladder in the presence of an external magnetic field. The susceptibility phase diagram has a rounded peak in the vicinity of T=7.4 K, obeys Troyer's law for low temperatures, and Curie's law for high temperatures. I also study the susceptibility diagram in low temperatures and I found the spin gap Δ=9.26 K, in good concordance with the experimental value, 9.5 K. In high field, I present a diagram of magnetization as a function of temperature. In the vicinity of a critical field, Hci, the magnetization scales with T1/2 and this result was found also in the QMC simulation. In all the results, there is a very good concordance with the experimental data. I also show in this paper that the spin gap is null and the susceptibility is proportional to T for low temperatures when relatively high values of the ladders' coupling is taken in account.

  12. Aqueous copper-mediated living polymerization: exploiting rapid disproportionation of CuBr with Me6TREN.

    Science.gov (United States)

    Zhang, Qiang; Wilson, Paul; Li, Zaidong; McHale, Ronan; Godfrey, Jamie; Anastasaki, Athina; Waldron, Christopher; Haddleton, David M

    2013-05-15

    A new approach to perform single-electron transfer living radical polymerization (SET-LRP) in water is described. The key step in this process is to allow full disproportionation of CuBr/Me6TREN (TREN = tris(dimethylamino)ethyl amine to Cu(0) powder and CuBr2 in water prior to addition of both monomer and initiator. This provides an extremely powerful tool for the synthesis of functional water-soluble polymers with controlled chain length and narrow molecular weight distributions (polydispersity index approximately 1.10), including poly(N-isopropylacrylamide), N,N-dimethylacrylamide, poly(ethylene glycol) acrylate, 2-hydroxyethyl acrylate (HEA), and an acrylamido glyco monomer. The polymerizations are performed at or below ambient temperature with quantitative conversions attained in minutes. Polymers have high chain end fidelity capable of undergoing chain extensions to full conversion or multiblock copolymerization via iterative monomer addition after full conversion. Activator generated by electron transfer atom transfer radical polymerization of N-isopropylacrylamide in water was also conducted as a comparison with the SET-LRP system. This shows that the addition sequence of l-ascorbic acid is crucial in determining the onset of disproportionation, or otherwise. Finally, this robust technique was applied to polymerizations under biologically relevant conditions (PBS buffer) and a complex ethanol/water mixture (tequila).

  13. Comparative study on gamma irradiation and cold plasma pretreatment for a cellulosic substrate modification with phenolic compounds

    Science.gov (United States)

    Irimia, Anamaria; Ioanid, Ghiocel Emil; Zaharescu, Traian; Coroabă, Adina; Doroftei, Florica; Safrany, Agnes; Vasile, Cornelia

    2017-01-01

    The efficiency of the activation of the cellulose/chitin mix substrate by cold plasma or γ-radiation exposure in order to modify it with bioactive compounds was studied. The eugenol or vegetable oils such as grape seed oil and rosehip seed oil have been grafted onto activated substrate. The examination of modified cellulose/chitin mix substrate by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy confirms that the structural and morphological changes took place in both cases. The grafting degrees of the surface layer estimated from XPS data varied from 31.1% to 58.7% for air cold plasma activation and from 9.7% to 22.8% for γ-irradiation treatment. They depend both on bioactive compound used and procedure of substrate activation. Higher grafting degree are obtain by using vegetable oils than in the case of modification with eugenol and the air cold plasma activation seems to be much efficient than γ-irradiation. By grafting the polymeric substrate with bioactive compounds, antimicrobial and antioxidant properties have been conferred. Such materials can be considered promising for food packaging applications and medical textiles and also the applied procedures are environmental friendly ones.

  14. Study of high energy (MeV) N{sup 6+} ion and gamma radiation induced modifications in low density polyethylene (LDPE) polymer

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, Ramandeep Kaur [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Singh, Paramjit [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078 (India); Gupta, Sanjeev Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078 (India); Department of Physics, Aggarwal College, Ballabgarh 121004 Faridabad (India); Singh, Surinder [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078 (India)

    2013-04-15

    The optical and structural response of low density polyethylene (LDPE) under the influence of 80 MeV N{sup 6+} ion at various fluences (5 × 10{sup 11} to 1 × 10{sup 13} ions/cm{sup 2}) and gamma rays at doses 100 and 1000 kGy were studied using UV–Vis spectroscopy and X-ray diffraction (XRD). The optical absorption spectra of N{sup 6+} ion irradiated LDPE showed a shift in the absorption edge towards higher wavelength side, which indicated a significant decrease in the direct and indirect band gaps of the films. The optical data showed decrease in the calculated band gap with increasing gamma dose. The diffraction pattern of pristine sample showed the semi crystalline nature of the polymer. The decrease in peak intensity and hence increase in amorphous nature was observed in N{sup 6+} ion irradiated samples. The opposite behavior is seen in case of gamma ray exposed samples at 100 kGy dose. The crystallite size (L) decreased but the other factors like interchain separation (R), interplanar distance (d), micro strain (ε), dislocation density (δ) and distortion parameters (g) increased for N{sup 6+} ion irradiated samples.

  15. A study on the effect of gamma irradiation on Poly [-Ethylene Oxide]: structural modification and variation in the kinetics of isoconversional phenomena

    Science.gov (United States)

    Mukhopadhyay, M.; Saha, M.; Ray, R.; Tarafdar, S.

    2016-10-01

    Interactions of Poly [-Ethylene Oxide] [PEO of molecular weight 105] and gamma irradiation with variable doses (1-30 kGy) are studied for the thermal, crystalline and structural properties using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) technique. Two states of PEO, viz. powder (P-S-series) and methanol solution (P-L-series) are subjected to irradiation and then cast into uniform films at room temperature. DSC results have revealed steady increment of crystallinity up to 20 kGy for P-S-series which starts reducing till 30 kGy. Conversely, P-L-series shows much enhanced crystallinity retained within low irradiation regime of 7 kGy, followed by sharp declining trend till 30 kGy. DSC is employed to study the influence of gamma radiation on multiple kinetic processes in an isoconversional melting of PEO using Friedman differential analysis. This study illustrates the variation of activation with degree of conversion of melting for different doses on irradiated PEO powder and methanol solution. Gamma irradiation is found to generate newer functional groups which are also established from FTIR study. Presence of -C=O and -C=C- groups in FTIR spectra reveals the predominance of scission during air assisted irradiation. FTIR spectra also prove higher degree of cross-linking in irradiation of methanol solution. The observations of DSC and FTIR are correlated with polymer microstructures. Therefore, selective irradiation dose can effectively be utilized to tailor the properties of PEO depending upon the exposed powder or methanol solution of polymer.

  16. Measurements of the work function of single-walled carbon nanotubes encapsulated by AgI, AgCl, and CuBr using Kelvin probe technique with different kinds of probes

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, A. A., E-mail: azhukov@issp.ac.ru [Russian Academy of Science, Institute of Solid State Physics (Russian Federation); Chernysheva, M. V.; Eliseev, A. A. [Moscow State University, Department of Materials Science (Russian Federation)

    2016-07-15

    We report the results on the measurements of the work function of single-walled carbon nanotubes encapsulated by Agl (AgI@SWCNT), AgCl (AgCl@SWCNT), and CuBr (CuBr@SWCNT) by the local Kelvin probe technique. We found the values of the work function of tubes encapsulated with AgI and AgCl (Φ(AgI@SWCNT) = 5.08 ± 0.02, Φ(AgCl@SWCNT) = 5.10 ± 0.02 eV) to exceed substantially that of pristine carbon nanotubes, and the value of the work function of carbon nanotubes encapsulated with CuBr is Φ(CuBr@SWCNT) = 4.89 ± 0.03 (eV). The measurements are carried out using different kinds of microscope probes including multi-walled carbon nanotube tips.

  17. Temperature calibration for high-temperature MAS NMR to 913 K: 63Cu MAS NMR of CuBr and CuI, and 23Na MAS NMR of NaNbO3.

    Science.gov (United States)

    Wu, Jingshi; Kim, Namjun; Stebbins, Jonathan F

    2011-09-01

    The solid-state phase transitions of CuBr, CuI and NaNbO(3) can be readily observed using (63)Cu and (23)Na high-temperature magic-angle spinning nuclear magnetic resonance spectroscopy. Temperature has large, linear effects on the peak maximum of (63)Cu in each solid phase of CuBr and CuI, and there is large jump in shift across each phase transition. The (23)Na MAS NMR peak intensities and the line widths in NaNbO(3) also clearly show its high-temperature transition to the cubic phase. These data can be used to calibrate high-temperature MAS NMR probes up to 913 K, which is two hundred degrees higher than the commonly-used temperature calibration based on the chemical shift of (207)Pb in Pb(NO(3))(2). Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Multilayer epitaxial growth of lead phthalocyanine and C(70) using CuBr as a templating layer for enhancing the efficiency of organic photovoltaic cells.

    Science.gov (United States)

    Kim, Tae-Min; Shim, Hyun-Sub; Choi, Min-Soo; Kim, Hyo Jung; Kim, Jang-Joo

    2014-03-26

    The molecular orientation and crystallinity of donor and acceptor molecules are important for high-efficiency organic photovoltaic cells (OPVs) because they significantly influence both the absorption of light and charge-transport characteristics. We report that the templating effect extends to multilayers to increase the crystallinity and to modify the orientation of the crystals of lead phthalocyanine (PbPc) and C70 layers at the same time by adopting CuBr as a new templating layer on indium tin oxide (ITO). The formation of a monoclinic phase with a preferred orientation of (320) for PbPc and a fcc phase with a preferred orientation of (220) for C70 on the PbPc layer is revealed by X-ray diffraction (XRD) patterns. The multilayer epitaxy results in an increase of the exciton diffusion lengths from 5.6 to 8.8 nm for PbPc and from 6.9 to 13.8 nm for C70 to enhance the power conversion efficiency (PCE) of the planar heterojunction OPVs composed of PbPc and C70 from 1.4 to 2.3%. The quasi-epitaxy model is proposed to explain the multilayer epitaxy.

  19. Oxidative stress promotes JNK-dependent amyloidogenic processing of normally expressed human APP by differential modification of alpha-, beta- and gamma-secretase expression.

    Science.gov (United States)

    Quiroz-Baez, Ricardo; Rojas, Emilio; Arias, Clorinda

    2009-12-01

    The pathogenesis of Alzheimer disease (AD) is complex and is certain to involve diverse etiological factors, but a central role has been strongly suggested for amyloid beta-protein (Abeta), based on genetic, biochemical and neurotoxicological evidence. In contrast with the well-documented effect of genetic mutations in Abeta overproduction, not much is known about the mechanisms involved in sporadic AD (SAD) which account for more than 95% of cases. Extensive data from patients and in vivo animal models indicate that oxidative stress is one of the cardinal factors most frequently associated with this neurodegenerative disease. The aim of the present study was to explore the effect of oxidative stress on the normally expressed wild-type amyloid precursor protein (APP) in human neuroblastoma cells, which represents a more physiological model of neuronal Abeta generation. Since H(2)O(2) is the main source of the highly reactive hydroxyl radical in the brain, and FeCl(2) can stimulate oxidative stress, including the formation of the hydroxyl radical from H(2)O(2), in the present work we studied the effect of these two pro-oxidant molecules on the levels and processing of human APP by alpha-, beta- and gamma-secretase, and the role of the stress-activated kinase c-jun N-terminal kinase (JNK). We provide evidence for a dual modulation of amyloid precursor protein metabolism in differentiated human neuroblastoma cells related with a down-regulation of alpha-secretase and up-regulation of gamma-secretase, and particularly of beta-secretase and also a JNK depending Abeta generation.

  20. Effects of modifications of the linker in a series of phenylpropanoic acid derivatives: Synthesis, evaluation as PPARalpha/gamma dual agonists, and X-ray crystallographic studies.

    Science.gov (United States)

    Casimiro-Garcia, Agustin; Bigge, Christopher F; Davis, Jo Ann; Padalino, Teresa; Pulaski, James; Ohren, Jeffrey F; McConnell, Patrick; Kane, Christopher D; Royer, Lori J; Stevens, Kimberly A; Auerbach, Bruce J; Collard, Wendy T; McGregor, Christine; Fakhoury, Stephen A; Schaum, Robert P; Zhou, Hairong

    2008-05-01

    A new series of alpha-aryl or alpha-heteroarylphenyl propanoic acid derivatives was synthesized that incorporate acetylene-, ethylene-, propyl-, or nitrogen-derived linkers as a replacement of the commonly used ether moiety that joins the central phenyl ring with the lipophilic tail. The effect of these modifications in the binding and activation of PPARalpha and PPARgamma was first evaluated in vitro. Compounds possessing suitable profiles were then evaluated in the ob/ob mouse model of type 2 diabetes. The propylene derivative 40 and the propyl derivative 53 demonstrated robust plasma glucose lowering activity in this model. Compound 53 was also evaluated in male Zucker diabetic fatty rats and was found to achieve normalization of glucose, triglycerides, and insulin levels. An X-ray crystal structure of the complex of 53 with the PPARgamma-ligand-binding domain was obtained and discussed in this report.

  1. Gamma Knife

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Gamma Knife Gamma Knife® is a radiation therapy that uses computerized treatment planning software to help ... sparing surrounding tissue. If you're scheduled for radiation therapy using Gamma Knife®, a treatment team consisting of a radiation ...

  2. Gamma Knife

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Gamma Knife Gamma Knife® is a radiation therapy that uses computerized treatment ... If you're scheduled for radiation therapy using Gamma Knife®, a treatment team consisting of a radiation oncologist, ...

  3. Preparation and characterization of poly(glycidyl methacrylate)-grafted magnetic nanoparticles: Effects of the precursor concentration on polyol synthesis of Fe3O4 and [PMDETA]0/[CuBr2]0 ratios on SI-AGET ATRP

    Science.gov (United States)

    Jiang, Liping; Zhou, Xuyang; Wei, Guyun; Lu, Xiaoduo; Wei, Weiping; Qiu, Jianhua

    2015-12-01

    Polymer brushes based on poly(glycidyl methacrylate) (PGMA) have been successfully grafted from the surface of silica coated iron oxide (Fe3O4@SiO2) nanoparticles via surface-initiated activators generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). The size of the nanoparticles could be adjusted from 7.3 to 9.6 nm by varying the precursor concentration of iron(III) acetylacetonate. The Fe3O4 nanoparticles possessed a highly crystalline structure, and the saturation magnetization of the as-prepared magnetite was strongly related to the particle size. Furthermore, the grafted PGMA content on the magnetic nanoparticles could be controlled by varying the ligand to transition metal ratio in a N,N,N‧,N″,N″-pentamethyldiethylenetriamine (PMDETA)/CuBr2 catalyst system. The maximum grafted content was 23.1% at a ratio of [PMDETA]0/[CuBr2]0 = 2:1.

  4. Crystal structure, thermal studies, Hirshfeld surface analysis, vibrational and DFT investigation of organic-inorganic hybrid compound [C9H6NOBr2]2CuBr4·2H2O

    Science.gov (United States)

    Mesbeh, Radhia; Hamdi, Besma; Zouari, Ridha

    2016-12-01

    Single crystals of a hybrid organic/inorganic material with the formula [C9H6NOBr2]2CuBr4·2H2O were studied by X-ray diffraction. The compound crystallizes in the monoclinic system, space group C2/c with the following unit cell parameters: a = 7.8201 (12) Ǻ, b = 18.203 (3) Ǻ, c = 19.486 (3) Ǻ, β = 98.330 (5)°, Z = 4, V = 2744.6 (7) Ǻ3. Crystal structure was solved with a final R = 5.66% for 3483 independent reflections. The atomic arrangement shows an alternation of organic and inorganic layers. Between layers, the cohesion is performed via Osbnd H⋯Br, Csbnd H⋯Br, Nsbnd H⋯Br, Nsbnd H⋯O and Osbnd H⋯O hydrogen bending. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) measurements have been carried out on [C9H6NOBr2]2CuBr4·2H2O crystal in the temperature range between 50 and 500 °C. The assignment of the observed bands in the solid state FTIR and Raman spectra of the compound was assisted by the theoretically predicted frequencies and compared with data previously reported for similar compounds. The theoretical geometrical parameters in the ground state have been investigated by density functional theory (DFT) with the B3LYP/LanL2DZ level of theory. The optical properties were investigated by optical absorption and show two bands at 279, 300 nm. The percentages of hydrogen bonding interactions are analyzed by Fingerprint plots of Hirshfeld surface.

  5. Ubiquitin modifications

    OpenAIRE

    Swatek, Kirby N.; Komander, David

    2016-01-01

    Protein ubiquitination is a dynamic multifaceted post-translational modification involved in nearly all aspects of eukaryotic biology. Once attached to a substrate, the 76-amino acid protein ubiquitin is subjected to further modifications, creating a multitude of distinct signals with distinct cellular outcomes, referred to as the 'ubiquitin code'. Ubiquitin can be ubiquitinated on seven lysine (Lys) residues or on the N-terminus, leading to polyubiquitin chains that can encompass complex top...

  6. Chemical modification of high molecular weight polyethylene through gamma radiation for biomaterials applications; Modificacao quimica de polietileno de alto peso molecular atraves de radiacao gama para aplicacao em biomateriais

    Energy Technology Data Exchange (ETDEWEB)

    Raposo, Matheus P.; Rocha, Marisa C.G., E-mail: matheusmerlim@hotmail.com [Universidade Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico

    2015-07-01

    Ultra high molecular weight polyethylene has been used in the medical field due to its high mechanical properties compared to the other polymers. Its main application is in the development of orthopedic implants, which requires high resistance to abrasion. One of the most used methods is the introduction of crosslinks in the polymer through gamma irradiation. In order to prevent oxidation reactions, studies have been developed using tacoferol (vitamin E) as an antioxidant for the material. The ascorbic acid (vitamin C), however, has been appointed as a viable alternative for vitamin E. In this work, a high molecular weight polyethylene grade (HMWPE) and polyethylene samples formulated with vitamin C were submitted to gamma radiation. Thermodynamic-mechanical methods and gel content determinations were used to characterize the samples obtained. The sample containing 1% of vitamin C and irradiated with 50 KGy of gamma radiation presented the highest content of crosslinks. (author)

  7. Synthesis, Crystal Structure and Third-order Nonlinear Optical Properties of Nest-shaped Cluster [CuBr (bpy) 2 ] [MoOS3Cu3-Br2 (bpy)

    Institute of Scientific and Technical Information of China (English)

    宋瑛林; 侯红卫; 樊耀亭; 杜晨霞; 朱玉

    2001-01-01

    Nest-shaped cluster [CuBr(bpy)2][MoOS3Cu3Br2(bpy)] was synthesized by the treatment of (NH4)2MoO2S2,CuBr and Et4NBr with bpy (2,2'-bipyridyl) in CH3CN. Its structure has been characterized by X-ray diffraction:monoclinic,space group P21/n, with a=1.0092(4), b=2.6347(7), c =1.4087(3) nm, β = 91.744(9)°, V=3.7438 nm3, Z=4,and final R=0.051, Rw=0.053. It consists of two parts:nest-shaped structural unit [MoOS3Cu3Br2(bpy)]- and complex ion [CuBr(bpy)2]+. We determined its third-order nonlinear optical (NLO) properties with a 7-ns pulsed laser at 532 nm. The cluster exhibits strong NIO refractive behavior, its third-order susceptibility X(3) was calculated to be 2.7× 10-11esu in a 7.8×10-4 g/cm3 DMF solution.The value is comparable to those of inorganic clusters.

  8. Gamma watermarking

    Science.gov (United States)

    Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

    2004-05-25

    A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

  9. Gamma watermarking

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

    2004-05-25

    A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

  10. Observation of in-medium modifications of the omega Meson

    NARCIS (Netherlands)

    Trnka, D.; Anton, G.; Bacelar, J.C.S; Bartholomy, O.; Bayadilov, D.; Beloglazov, Y.A.; Bogendorfer, R.; Castelijns, R.J.J.; Crede, V.; Dutz, H.; Ehmanns, A.; Elsner, D.; Ewald, R.; Fabry, I.; Fuchs, M.; Essig, K.; Funke, Ch.; Gothe, R.; Gregor, R.; Gridnev, A.; Gutz, E.; Hoffgen, S.K.; Hoffmeister, P.; Horn, I.; Hössl, J.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Klein, Frank; Klein, Fritz; Klempt, E.; Konrad, M.; Kopf, B.; Kotulla, M.; Krusche, B.; Langheinrich, J.; Löhner, H.; Lopatin, I.; Lotz, J.; Lugert, S.; Menze, D.W.; Messchendorp, J.G.; Mertens, T.; Metag, V.; Morales, C.; Nanova, M.; Novotny, R.; Ostrick, M.; Pant, L.M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Radkov, A.; Schadmand, S.; Schmidt, Ch.; Schmieden, H.; Schoch, B.; Shende, S.; Suft, G.; Sumachev, V.; Szczepanek, T.; Sule, A.; Thoma, U.; Varma, R.; Walther, D.; Weinheimer, Ch.; Wendel, Ch.

    2005-01-01

    The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction gamma+A ->omega+X ->pi(0)gamma+X-'. Results obtained for N

  11. gamma-gamma Interactions from Real to Virtual Photons

    CERN Document Server

    Sjöstrand, Torbjörn

    2000-01-01

    A `complete' framework for gamma-gamma / gamma*-gamma / gamma*-gamma* interactions is presented. The emphasis is on providing a model for gamma-gamma physics at all photon virtualities, including the difficult transition region around the rho meson mass.

  12. The interplay of post-translational modification and gene therapy

    Directory of Open Access Journals (Sweden)

    Osamor VC

    2016-02-01

    Full Text Available Victor Chukwudi Osamor,1–3 Shalom N Chinedu,3,4 Dominic E Azuh,3,5 Emeka Joshua Iweala,3,4 Olubanke Olujoke Ogunlana3,4 1Covenant University Bioinformatics Research (CUBRe Unit, Department of Computer and Information Sciences, College of Science and Technology (CST, Covenant University, Ota, Ogun State, Nigeria; 2Institute of Informatics (Computational biology and Bioinformatics, Faculty of Mathematics, Informatics and Mechanics, University of Warsaw (Uniwersytet Warszawski, Warszawa, Poland; 3Covenant University Public Health and Well-being Research Group (CUPHWERG, Covenant University, 4Biochemistry and Molecular Biology Unit, Department of Biological Sciences, College of Science and Technology, Covenant University, Canaan Land, 5Department of Economics and Development Studies, Covenant University, Ota, Ogun State, Nigeria Abstract: Several proteins interact either to activate or repress the expression of other genes during transcription. Based on the impact of these activities, the proteins can be classified into readers, modifier writers, and modifier erasers depending on whether histone marks are read, added, or removed, respectively, from a specific amino acid. Transcription is controlled by dynamic epigenetic marks with serious health implications in certain complex diseases, whose understanding may be useful in gene therapy. This work highlights traditional and current advances in post-translational modifications with relevance to gene therapy delivery. We report that enhanced understanding of epigenetic machinery provides clues to functional implication of certain genes/gene products and may facilitate transition toward revision of our clinical treatment procedure with effective fortification of gene therapy delivery. Keywords: post-translational modification, gene therapy, epigenetics, histone, methylation

  13. GAMMA-400 gamma-ray observatory

    CERN Document Server

    Topchiev, N P; Bonvicini, V; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bakaldin, A V; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Cumani, P; Dalkarov, O D; Dedenko, G L; De Donato, C; Dogiel, V A; Finetti, N; Gascon, D; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Martinez, M; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Paredes, J M; Pearce, M; Picozza, P; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Stozhkov, Yu I; Suchkov, S I; Taraskin, A A; Tavani, M; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Ward, J E; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The energy range of GAMMA-400 is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 20 TeV for electrons + positrons, and up to 10E15 eV for cosmic-ray nuclei. For high-energy gamma rays with energy from 10 to 100 GeV, the GAMMA-400 angular resolution improves from 0.1{\\deg} to ~0.01{\\deg} and energy resolution from 3% to ~1%; the proton rejection factor is ~5x10E5. GAMMA-400 will be installed onboard the Russian space observatory.

  14. Readers of histone modifications

    Institute of Scientific and Technical Information of China (English)

    Miyong Yun; Jun Wu; Jerry L Workman; Bing Li

    2011-01-01

    Histone modifications not only play important roles in regulating chromatin structure and nuclear processes but also can be passed to daughter cells as epigenetic marks.Accumulating evidence suggests that the key function of histone modifications is to signal for recruitment or activity of downstream effectors. Here, we discuss the latest discovery of histone-modification readers and how the modification language is interpreted.

  15. A scheme for assessing the performance characteristics of small field-of-view gamma cameras.

    Science.gov (United States)

    Bhatia, B S; Bugby, S L; Lees, J E; Perkins, A C

    2015-02-01

    Existing protocols for assessing the performance characteristics of large field-of-view (LFOV) gamma cameras can be inappropriate and require modification for use with small field-of-view (SFOV) gamma camera systems. This communication proposes a generic scheme suitable for evaluating the performance characteristics of SFOV gamma cameras, based on modifications to the standard procedures of NEMA NU1-2007. Key differences in methodology between tests for LFOV and SFOV gamma cameras are highlighted along with the rationale for these changes. It is envisaged that this scheme will provide more appropriate methods for equipment characterisation, ensuring quality and consistency for all SFOV cameras.

  16. GammaWorkshops Proceedings

    DEFF Research Database (Denmark)

    Strålberg, Elisabeth; Klemola, Seppo; Nielsen, Sven Poul;

    Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activitie...

  17. Behavior Modification in Coaching.

    Science.gov (United States)

    Lynch, Annette Rutt; Stillman, Stephen M.

    1979-01-01

    An example of behavior modification used in athletic coaching is presented. The case study involves a member of a women's basketball team and details the use of behavior modification for both weight reduction and skill improvement. (JMF)

  18. Rehabilitation of gamma

    Science.gov (United States)

    Poynton, Charles A.

    1998-07-01

    Gamma characterizes the reproduction of tone scale in an imaging system. Gamma summarizes, in a single numerical parameter, the nonlinear relationship between code value--in an 8-bit system, from 0 through 255--and physical intensity. Nearly all image coding systems are nonlinear, and so involve values of gamma different from unity. Owing to poor understanding of tone scale reproduction, and to misconceptions about nonlinear coding, gamma has acquired a terrible reputation in computer graphics and image processing. In addition, the world-wide web suffers from poor reproduction of grayscale and color images, due to poor handling of nonlinear image coding. This paper aims to make gamma respectable again.

  19. Raman and AFM study of gamma irradiated plastic bottle sheets

    Science.gov (United States)

    Ali, Yasir; Kumar, Vijay; Sonkawade, R. G.; Dhaliwal, A. S.

    2013-02-01

    In this investigation, the effects of gamma irradiation on the structural properties of plastic bottle sheet are studied. The Plastic sheets were exposed with 1.25MeV 60Co gamma rays source at various dose levels within the range from 0-670 kGy. The induced modifications were followed by micro-Raman and atomic force microscopy (AFM). The Raman spectrum shows the decrease in Raman intensity and formation of unsaturated bonds with an increase in the gamma dose. AFM image displays rough surface morphology after irradiation. The detailed Raman analysis of plastic bottle sheets is presented here, and the results are correlated with the AFM observations.

  20. MODIFICATION OF DELTA FOR CHOOSER OPTIONS

    Directory of Open Access Journals (Sweden)

    Marek Ďurica

    2015-09-01

    Full Text Available Correctly used financial derivatives can help investors increase their expected returns and minimize their exposure to risk. To ensure the specific needs of investors, a large number of different types of non-standard exotic options is used. Chooser option is one of them. It is an option that gives its holder the right to choose at some predetermined future time whether the option will be a standard call or put with predetermined strike price and maturity time. Although the chooser options are more expensive than standard European-style options, in many cases they are a more suitable instrument for investors in hedging their portfolio value. For an effective use of the chooser option as a hedging instrument, it is necessary to check the values of the Greek parameters delta and gamma for the options. Especially, if the value of the parameter gamma is too large, hedging of the portfolio value using only parameter delta is insufficient and brings high transaction costs because the portfolio has to be reviewed relatively often. Therefore, in this article, a modification of delta-hedging as well as using the value of parameter gamma is suggested. Error of the delta modification is analyzed and compared with the error of widely used parameter delta. Typical patterns for the modified hedging parameter variation with various time to choose time for chooser options are also presented in this article.

  1. Measurement of. gamma. gamma. widths of charmonium states

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.Y.; McIlwain, R.L.; Miller, D.H.; Ng, C.R.; Schaffner, S.F.; Shibata, E.I.; Yao, W.M. (Purdue Univ., Lafayette, IN (USA)); Sparks, K.; Thorndike, E.H.; Wang, C.H. (Rochester Univ., NY (USA)); Alam, M.S.; Kim, I.J.; Li, W.C.; Lou, X.C.; Sun, C.R.; Wang, P.N.; Zoeller, M.I. (State Univ. of New York, Albany (USA)); Bortoletto, D.; Goldberg, M.; Horwitz, N.; Jain, V.; Mestayer, M.D.; Moneti, G.C.; Sharma, V.; Shipsey, I.P.J.; Skwarnicki, T.; Thulasidas, M. (Syracuse Univ., NY (USA)); Csorna, S.E.; Letson, T. (Vanderbilt Univ., Nashville, TN (USA)); Alexander, J.; Artuso, M.; Bebek, C.; Berkelman, K.; Cassel, D.G.; Cheu, E.; Coffman, D.M.; Crawford, G.; DeWire, J.W.; Dell, P.S.; Ehrlich, R.; Galik, R.S.; Gittelman, B.; Gray, S.W.; Halling, A.M.; Hartill, D.L.; Heltsley, B.K.; Kandaswamy, J.; Katayama, N.; Kreinick, D.L.; Lewis, J.D.; Mistry, N.B.; Mueller, J.; Namjoshi, R.; Nandi, S.; Nordberg, E.; O' Grady, C.; Peterson, D.; Pisharody, M.; Riley, D.; Sapper, M.; Silverman, A.

    1990-06-21

    Using the CLEO detector at the Cornell Electron Storage Ring, we have searched for two-phonon production of charmonium in four-track final states. We have measured {Gamma}{sub {gamma}{gamma}}({eta}{sub c})=5.9{sub -1.8}{sup +2.1}{plus minus}1.9 keV, and we have obtained 95% CL upper limits of {Gamma}{sub {gamma}{gamma}}({chi}{sub c0})<6.2 keV and {Gamma}{sub {gamma}{gamma}}({chi}{sub c2})<1.0 keV. (orig.).

  2. Gamma Splines and Wavelets

    Directory of Open Access Journals (Sweden)

    Hannu Olkkonen

    2013-01-01

    Full Text Available In this work we introduce a new family of splines termed as gamma splines for continuous signal approximation and multiresolution analysis. The gamma splines are born by -times convolution of the exponential by itself. We study the properties of the discrete gamma splines in signal interpolation and approximation. We prove that the gamma splines obey the two-scale equation based on the polyphase decomposition. to introduce the shift invariant gamma spline wavelet transform for tree structured subscale analysis of asymmetric signal waveforms and for systems with asymmetric impulse response. Especially we consider the applications in biomedical signal analysis (EEG, ECG, and EMG. Finally, we discuss the suitability of the gamma spline signal processing in embedded VLSI environment.

  3. Enzymatic modification of starch

    DEFF Research Database (Denmark)

    Jensen, Susanne Langgård

    In the food industry approaches for using bioengineering are investigated as alternatives to conventional chemical and physical starch modification techniques in development of starches with specific properties. Enzyme-assisted post-harvest modification is an interesting approach to this, since...... branching connecting larger chain segments. In case of high BE activity this transfer happened prior to hydration and phase separation. The starch substrates thereby became locked in their granular structure and blocked furher access of BE. Transferase-based modification of starch has today almost...... exclusively been conducted on gelatinized starch. This study provides a new concept for transferase-based modification of starches in granular state....

  4. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  5. How the $\\gamma \\gamma$ Resonance Stole Christmas

    CERN Document Server

    Craig, Nathaniel; Kilic, Can; Thomas, Scott

    2015-01-01

    The experimental and theoretical implications of heavy di-gauge boson resonances that couple to, or are comprised of, new charged and strongly interacting matter are investigated. Observation and measurement of ratios of the resonant di-gauge boson channels $WW$, $ZZ$, $\\gamma \\gamma$, $Z \\gamma$, and $gg$ in the form of di-jets, provide a rather direct -- and for some ratios a rather robust -- probe of the gauge representations of the new matter. For a spin-zero resonance with the quantum numbers of the vacuum, the ratios of resonant $WW$ and $ZZ$ to $\\gamma \\gamma$ channels, as well as the longitudinal versus transverse polarization fractions in the $WW$ and $ZZ$ channels, provide extraordinarily sensitive probes for possible mixing with the Higgs boson, while di-Higgs and di-top resonant channels, $hh$ and $tt$, provide somewhat less sensitivity. We present a survey of possible underlying models for di-gauge boson resonances by considering various limits for the mass of the new charged and strongly interac...

  6. Licensing by modification Licensing by modification

    Directory of Open Access Journals (Sweden)

    Veneeta Dayal

    2008-04-01

    Full Text Available Abstract: This paper looks at the phenomena of licensing by modification, whereby an unacceptable noun phrase is redeemed by the presence of a modifier or an unavailable reading for a noun phrase is made available with the addition of a modifier. It argues that an optimal account of such phenomena should derive these effects from the interaction of the meanings of individual expressions in the sentence rather than by positing a formal licensing relation between the modifier and the noun it modifies. The general approach is explicated by considering the distribution of bare plurals in Italian and the availability of generic readings for plural definites in English. The overall goal is a modest one. It seeks to draw attention to properties of modification that go beyond set intersection by focusing on phenomena that have not so far been closely scrutinized in the literature. It uses the particular results to draw some conclusions about questions of general interest.Licensing by modification Abstract: This paper looks at the phenomena of licensing by modification, whereby an unacceptable noun phrase is redeemed by the presence of a modifier or an unavailable reading for a noun phrase is made available with the addition of a modifier. It argues that an optimal account of such phenomena should derive these effects from the interaction of the meanings of individual expressions in the sentence rather than by positing a formal licensing relation between the modifier and the noun it modifies. The general approach is explicated by considering the distribution of bare plurals in Italian and the availability of generic readings for plural definites in English. The overall goal is a modest one. It seeks to draw attention to properties of modification that go beyond set intersection by focusing on phenomena that have not so far been closely scrutinized in the literature. It uses the particular results to draw some conclusions about questions of general

  7. Permit application modifications

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils.

  8. The effect of a gamma ray flare on Schumann resonances

    Directory of Open Access Journals (Sweden)

    A. P. Nickolaenko

    2012-09-01

    Full Text Available We describe the ionospheric modification by the SGR 1806-20 gamma flare (27 December 2004 seen in the global electromagnetic (Schumann resonance. The gamma rays lowered the ionosphere over the dayside of the globe and modified the Schumann resonance spectra. We present the extremely low frequency (ELF data monitored at the Moshiri observatory, Japan (44.365° N, 142.24° E. Records are compared with the expected modifications, which facilitate detection of the simultaneous abrupt change in the dynamic resonance pattern of the experimental record. The gamma flare modified the current of the global electric circuit and thus caused the "parametric" ELF transient. Model results are compared with observations enabling evaluation of changes in the global electric circuit.

  9. Transition Distribution Amplitudes for gamma* gamma collisions

    CERN Document Server

    Lansberg, J P; Szymanowski, L

    2008-01-01

    We study the exclusive production of pi-pi and rho-pi in hard gamma* gamma scattering in the forward kinematical region where the virtuality of one photon provides us with a hard scale in the process. The newly introduced concept of Transition Distribution Amplitudes (TDA) is used to perform a QCD calculation of these reactions thanks to two simple models for TDAs. The sizable cross sections for rho-pi and pi-pi production may be tested at intense electron-positron colliders such as CLEO and B factories (Belle and BaBar).

  10. Gamma-ray triangles

    DEFF Research Database (Denmark)

    Ibarra, Alejandro; Lopez-Gehler, Sergio; Molinaro, Emiliano

    2016-01-01

    We introduce a new type of gamma-ray spectral feature, which we denominate gamma-ray triangle. This spectral feature arises in scenarios where dark matter self-annihilates via a chiral interaction into two Dirac fermions, which subsequently decay in flight into another fermion and a photon. The r...

  11. Galactic gamma ray astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, V.

    1982-05-01

    During the last decade the exploration of the sky in the light of gamma rays has begun by means of satellite-and balloon-borne instruments. Like in other ranges of the electromagnetic spectrum the Milky Way clearly stands out against the rest of the sphere. Part of the galactic ..gamma..-ray emission is due to discrete sources, part is diffuse in origin and is produced in interstellar space. Some of the discrete ..gamma..-ray sources are radio pulsars, the nature of the other sources is still unknown. The intensity distribution of the diffuse galactic ..gamma..-ray component is consistent with a decrease of the cosmic-ray intensity towards the outer part of the galaxy. The identification of the cosmic-ray sources will be one of the main objectives of the next generation of ..gamma..-ray telescopes.

  12. Momentum Dependent Vertices $\\sigma \\gamma \\gamma$, $\\sigma \\rho \\gamma$ and $\\sigma \\rho \\rho$ : The NJL Scalar Hidden by Chiral Symmetry

    OpenAIRE

    Bajc, B.; Blin, A. H.; Hiller, B.; Nemes, M. C.; Rosina, M.

    1994-01-01

    We calculate the momentum dependence of three particle vertices $\\sigma \\gamma \\gamma$, $\\sigma \\rho \\gamma$ and $\\sigma \\rho \\rho$ in the context of a Nambu Jona Lasinio type model. We show how they influence the processes $\\gamma \\gamma \\rightarrow \\sigma \\rightarrow \\pi \\pi$, $\\rho \\rightarrow \\gamma \\sigma$ and $\\gamma \\gamma \\rightarrow \\rho \\rho$ and how chiral symmetry shadows the presence of the $\\sigma$.

  13. Colliding. gamma. e- and. gamma gamma. -beams on the basis of electron-positron linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Tel' nov, V.I.

    1983-08-01

    Main properties of the ..gamma..e and ..gamma gamma.. collisions are discussed in some detail with application to the generation of colliding ..gamma..e and ..gamma gamma.. beams basing on the designed linear accelerators with colliding e/sup +/e/sup -/ beams, VLEEP and SLC, as it was proposed in a previous work. Intensive ..gamma.. beams with the energy 50 GeV would be produced from scattering of the laser light focused to the electron beams of the accelerators. Laser radiation is focused to the electron beam in the conversion region at a distance of about 10 cm from the place of collision. After scattering on electrons high-energy photons move practically along the electron primary trajectories and are focused in the collision region. The electrons are deflected from the collision region by means of approximately 1 T magnetic field. Then the produced ..gamma..-beam collides with an electron beam or a similar ..gamma..-beam. In the case when the maximum luminosity (L) is attained, the luminosity distribution in the invariant mass of the ..gamma..e or ..gamma gamma.. systems is wide. A monochromatization of the collisions up to the level of 5-10% is possible. That will entail a decrease in the luminosity, the procedure is most effective if one uses the electrons and the laser photons with opposite helicities. Examples of physically interesting problems to be investigated with the proposed ..gamma..e and ..gamma gamma.. beams are suggested.

  14. Enzymatic modification of starch

    DEFF Research Database (Denmark)

    Jensen, Susanne Langgård

    substrate, and granular products were only obtained at low hydration of the starch. Hence, limiting hydration and gelatinization by using low-phosphate starch and high substrate oncentration was required for obtaining these products. Also high BE activity was a requirement and could partly compensate...... exclusively been conducted on gelatinized starch. This study provides a new concept for transferase-based modification of starches in granular state.......In the food industry approaches for using bioengineering are investigated as alternatives to conventional chemical and physical starch modification techniques in development of starches with specific properties. Enzyme-assisted post-harvest modification is an interesting approach to this, since...

  15. GammaWorkshops Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramebaeck, H. (ed.) (Swedish Defence Research Agency (Sweden)); Straalberg, E. (Institute for Energy Technology, Kjeller (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority, STUK (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (Iceland))

    2012-01-15

    Due to a sparse interaction during the last years between practioners in gamma ray spectrometry in the Nordic countries, a NKS activity was started in 2009. This GammaSem was focused on seminars relevant to gamma spectrometry. A follow up seminar was held in 2010. As an outcome of these activities it was suggested that the 2011 meeting should be focused on practical issues, e.g. different corrections needed in gamma spectrometric measurements. This three day's meeting, GammaWorkshops, was held in September at Risoe-DTU. Experts on different topics relevant for gamma spectrometric measurements were invited to the GammaWorkshops. The topics included efficiency transfer, true coincidence summing corrections, self-attenuation corrections, measurement of natural radionuclides (natural decay series), combined measurement uncertainty calculations, and detection limits. These topics covered both lectures and practical sessions. The practical sessions included demonstrations of tools for e.g. corrections and calculations of the above meantioned topics. (Author)

  16. The gamma function

    CERN Document Server

    Artin, Emil

    2015-01-01

    This brief monograph on the gamma function was designed by the author to fill what he perceived as a gap in the literature of mathematics, which often treated the gamma function in a manner he described as both sketchy and overly complicated. Author Emil Artin, one of the twentieth century's leading mathematicians, wrote in his Preface to this book, ""I feel that this monograph will help to show that the gamma function can be thought of as one of the elementary functions, and that all of its basic properties can be established using elementary methods of the calculus."" Generations of teachers

  17. Benign Weather Modification

    Science.gov (United States)

    2007-11-02

    operational interest in modifying weather to support combat operations increased, ultimately leading to a multi-service effort called PROJECT POPEYE . The goal...This, coupled with the revelations concerning weather modification use in the Vietnam War (PROJECT POPEYE ), was a double blow to weather modification...AWS-TR-74-247, June 1984. Cobb, James T., Jr., et. al. Project Popeye : Final Report. China Lake, CA: Naval Weapons Center, 1967. Langmuir, Irving

  18. Antimicrobial Modifications of Polymers

    OpenAIRE

    Sedlarik, Vladimir

    2013-01-01

    This chapter is focused on antimicrobial modifications of polymer materials intended for medical devices production. Firstly, a brief introduction into the field of medical application of polymers is presented. Considering the fact that polymer medical devices are often connected with occurrence of nosocomial infections, the next part refers to this phenomenon and its causes. One of the possibilities of reducing of the infection occurrence is aimed at polymer modification. It is a key topic o...

  19. Modification as a propositional act

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2014-01-01

    in Functional Discourse Grammar. Apart from Attitudinal Modification, there are at least five Subacts of Modification that are required for an adequate functional analysis of noun phrases and clauses: classifying modification, qualifying modification, quantifying modification, localizing modification......A complete functional theory of grammar should be able to specify the communicative function of each constituent in a sentence (or rather ‘Discourse Act’). Whereas predicating and referring have been given due attention in functional approaches to grammar, the modifying function of linguistic...

  20. Human Rights and Behavior Modification

    Science.gov (United States)

    Roos, Philip

    1974-01-01

    Criticisms of behavior modification, which charge that it violates ethical and legal principles, are discussed and reasons are presented to explain behavior modification's susceptibility to attack. (GW)

  1. Stereotactic radiosurgery - Gamma Knife

    Science.gov (United States)

    ... being treated. As compared to other types of radiation therapy, Gamma Knife treatment is much less likely to damage ... of radiosurgery alone vs radiosurgery with whole brain radiation ... Knife radiosurgery patient resource center. 2015. www.elekta. ...

  2. Dynamic gamma knife radiosurgery.

    Science.gov (United States)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-21

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C and Perfexion units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the dose

  3. Dynamic gamma knife radiosurgery

    Science.gov (United States)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

  4. Dynamic gamma knife radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shuang; Swanson, Nathan; Chen Zhe [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Ma Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143 (United States)], E-mail: sluan@cs.unm.edu, E-mail: nate@cs.unm.edu, E-mail: zchen@cs.unm.edu, E-mail: lijunma@radonc.ucsf.edu

    2009-03-21

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can

  5. Characterizations of {\\Gamma}-AG^{**}-groupoids by their {\\Gamma}-ideals

    CERN Document Server

    Khan, Madad

    2010-01-01

    In this paper we have discusses {\\Gamma}-left, {\\Gamma}-right, {\\Gamma}-bi-, {\\Gamma}-quasi-, {\\Gamma}-interior and {\\Gamma}-ideals in {\\Gamma}-AG^{**}-groupoids and regular {\\Gamma}-AG^{**}-groupoids. Moreover we have proved that the set of {\\Gamma}-ideals in a regular {\\Gamma}-AG^{**}-groupoid form a semilattice structure. Also we have characterized a regular {\\Gamma}-AG^{**}-groupoid in terms of left ideals.

  6. Characterizations of gamma-AG^{**}-groupoids by the properties their gamma-ideals

    CERN Document Server

    Khan, Madad; Rehman, Inayatur

    2010-01-01

    In this paper we have discusses {\\Gamma}-left, {\\Gamma}-right, {\\Gamma}-bi-, {\\Gamma}-quasi-, {\\Gamma}-interior and {\\Gamma}-ideals in {\\Gamma}-AG^{**}-groupoids and regular {\\Gamma}-AG^{**}-groupoids. Moreover we have proved that the set of {\\Gamma}-ideals in a regular {\\Gamma}-AG^{**}-groupoid form a semilattice structure. Also we have characterized a regular {\\Gamma}-AG^{**}-groupoid in terms of left ideals.

  7. Structural dynamic modification

    Indian Academy of Sciences (India)

    A Sestieri

    2000-06-01

    Vibration and acoustic requirements are becoming increasingly important in the design of mechanical structures, but they are not usually of primary concern in the design process. So the need to vary the structural behaviour to solve noise and vibration problems often occurs at the prototype stage, giving rise to the so-called structural modification problem. In this paper, the direct problem of determing the new response of a system, after some modifications are introduced into the sestem, is analysed using two different databases: the modal database and the frequency response function database. The limitaions of the modal database are discussed. Structural modifications that can be accounted for are lumped masses, springs, dampers and dynamic absorbers.

  8. Organic modification of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic modification of carbon nanotubes is a novel research field being developed recently. In this article, the history and newest progress of organic modification of carbon nanotubes are reviewed from two aspects:organic covalent modification and organic noncovalent modification of carbon nanotubes. The preparation and properties of organic modified carbon nanotubes are discussed in detail. In addition, the prospective development of organic modification of carbon nanotubes is suggested.

  9. Gamma ray camera

    Science.gov (United States)

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  10. Gamma Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

  11. Gamma ray camera

    Science.gov (United States)

    Perez-Mendez, Victor

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  12. Bremsstrahlung gamma rays from light Dark Matter

    CERN Document Server

    Cirelli, Marco; Zaharijas, Gabrijela

    2013-01-01

    We discuss the often-neglected role of bremsstrahlung processes on the interstellar gas in computing indirect signatures of Dark Matter (DM) annihilation in the Galaxy, particularly for light DM candidates in the phenomenologically interesting O(10) GeV mass range. Especially from directions close to the Galactic Plane, the expected gamma-ray spectrum is altered via two effects: directly, by the photons emitted in the bremsstrahlung process on the interstellar gas by energetic electrons which are among the DM annihilation byproducts; indirectly, by the modification of the same electron spectrum, due to the additional energy loss process in the diffusion-loss equation (e.g. the resulting inverse Compton emission is altered). We quantify the importance of the bremsstrahlung emission in the GeV energy range, showing that it is the dominant component of the gamma-ray spectrum for some cases. We also find that, in regions in which bremsstrahlung dominates energy losses, the related gamma-ray emission is only moder...

  13. Biblical behavior modification.

    Science.gov (United States)

    Lasure, L C; Mikulas, W L

    1996-07-01

    Although we may have formalized and systematized the field of behavior modification in the last few decades, people around the world have been using behavioral change strategies throughout history. Premack's (1965) theory of reinforcement is often called "Grandma's rule" because grandmothers have long been using it (e.g. You must finish your vegetables before you may go out and play). Franks (1969, p. 4), in one of the first behavioral texts, gave historical examples from China, Turkey, France, and Italy. Knapp and Shodahl (1974) showed how Benjamin Franklin used behavior modification. And de Silva (1984, 1985) gave examples of behavior modification by the Buddha and other early Buddhists. Conspicuously absent from our literature are examples from the Judeo-Christian tradition. In this paper, we provide a number of behavior modification examples from the Bible (New International Version). Footnotes provide references for many more examples. In the discussion, we explore implications for education and therapy. Examples are grouped by the following categories: operant conditioning, respondent conditioning, modeling, and cognitive interventions. However, the Biblical examples, like contemporary case studies, do not always fall neatly into discrete categories. They often are a combination, particularly operant and respondent conditioning interweaving.

  14. Context modification in action

    NARCIS (Netherlands)

    Visser, A.

    2008-01-01

    In this paper we develop the positive fragment of Context Modification Logic. This logical system is a variant of Dynamic Predicate Logic that employs multiple-access variables and that treats argument places in the same way as Latin. The positive fragment is purely incremental.

  15. SVOM Gamma Ray Monitor

    CERN Document Server

    Dong, Yongwei; Li, Yanguo; Zhang, Yongjie; Zhang, Shuangnan

    2009-01-01

    The Space-based multi-band astronomical Variable Object Monitor (SVOM) mission is dedicated to the detection, localization and broad-band study of Gamma-Ray Bursts (GRBs) and other high-energy transient phenomena. The Gamma Ray Monitor (GRM) onboard is designed to observe the GRBs up to 5 MeV. With this instrument one of the key GRB parameter, Epeak, can be easily measured in the hard x-ray band. It can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

  16. Measurement of the gamma gamma* --> eta and gamma gamma* --> eta' transition form factors

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez et al, P.

    2011-02-07

    We study the reactions e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sup (/)} in the single-tag mode and measure the {gamma}{gamma}* {yields} {eta}{sup (/)} transition form factors in the momentum transfer range from 4 to 40 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

  17. Gamma measurements at LHCb

    CERN Document Server

    Cheung, Faye

    2016-01-01

    Recent measurements of the CKM angle g from charged and neutral B$\\rightarrow$ DK(*) decays, with a variety of D final states, are presented. The measurements are performed using proton-proton collision data corresponding to an integrated luminosity of 3 fb$^{-1}$ collected at the LHCb experiment during Run I of the LHC. The results of a combination of LHCb g measurements are discussed. The combined value of $\\gamma$ is $(70.9^{+7.1}_{-8.5})^{\\circ}$ and is the most precise measurement of $\\gamma$ from a single experiment.

  18. SVOM gamma ray monitor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient phenomena.The gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 MeV.With this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray band.It can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

  19. Effect of gamma irradiation on Anaplasma marginale in bovines

    Energy Technology Data Exchange (ETDEWEB)

    Romero, H.Q.; de Fernandez, M.V.G. (Universidad Nacional Autonoma de Mexico, Mexico City. Centro de Estudios Nucleares); Meza, B.R.; Rodriguez, E. (Universidad Nacional Autonoma de Mexico, Mexico City)

    1981-01-01

    Because the costs of treatment of anaplasmosis are very high, it was considered of great usefulness to obtain the modification of the pathogenecity and the antigenicity of A. marginale by means of gamma radiation (/sup 60/Co) to obtain a vaccine. This would be reflected favorably in saving lives as well as to obviate losses of meat and dairy production and the elimination of the risks derived from the introduction of selected cattle into the tropics. The main purpose of this study was to determine the optimal modification of the pathogenecity of A. marginale in splenectomized calves and adult cows, among 4 different radiation doses.

  20. Posttranslational protein modification in Archaea.

    Science.gov (United States)

    Eichler, Jerry; Adams, Michael W W

    2005-09-01

    One of the first hurdles to be negotiated in the postgenomic era involves the description of the entire protein content of the cell, the proteome. Such efforts are presently complicated by the various posttranslational modifications that proteins can experience, including glycosylation, lipid attachment, phosphorylation, methylation, disulfide bond formation, and proteolytic cleavage. Whereas these and other posttranslational protein modifications have been well characterized in Eucarya and Bacteria, posttranslational modification in Archaea has received far less attention. Although archaeal proteins can undergo posttranslational modifications reminiscent of what their eucaryal and bacterial counterparts experience, examination of archaeal posttranslational modification often reveals aspects not previously observed in the other two domains of life. In some cases, posttranslational modification allows a protein to survive the extreme conditions often encountered by Archaea. The various posttranslational modifications experienced by archaeal proteins, the molecular steps leading to these modifications, and the role played by posttranslational modification in Archaea form the focus of this review.

  1. Wsup(+-) boson production at the e/sup +/e/sup -/,. gamma. e and. gamma gamma. colliding beams

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Panfil, S.L.; Serbo, V.G.

    1983-11-21

    Wsup(+-) boson production in e/sup +/e/sup -/->W/sup +/W/sup -/, ..gamma..e->W/sup +/W/sup -/, ..gamma..e->W, ..gamma gamma..->W/sup +/W/sup -/ reactions at the e/sup +/e/sup -/, ..gamma..e and ..gamma gamma.. colliding beams is considered. What physical information can be extracted from such experiments, including those with polarized beams, is discussed. Conditions of observation, are considered together with the background problems.

  2. CKM angle $\\gamma$ from LHCb

    CERN Multimedia

    Smith, Jackson

    2015-01-01

    Results of the latest $\\gamma$ combination from LHCb are presented, along with the six LHCb measurements used as inputs. In addition, the anticipated precision attainable for measuring $\\gamma$ after the LHCb Upgrade is outlined

  3. Gamma knife surgery for craniopharyngioma.

    Science.gov (United States)

    Prasad, D; Steiner, M; Steiner, L

    1995-01-01

    We present our results of Gamma Knife surgery for craniopharyngioma in nine patients. The current status of surgery, radiation therapy, intracavitary instillation of radionucleides and Gamma Knife surgery in the management of craniopharyngiomas is discussed.

  4. Interferon Gamma-1b Injection

    Science.gov (United States)

    Interferon gamma-1b injection is used to reduce the frequency and severity of serious infections in people with ... with severe, malignant osteopetrosis (an inherited bone disease). Interferon gamma-1b is in a class of medications called ...

  5. Construction of a {gamma}-{gamma} and {beta}-{gamma} coincidence measurement system for precise determination of nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Furutaka, Kazuyoshi; Nakamura, Shoji; Harada, Hideo; Katoh, Toshio [Japan Nuclear Cycle Development Institute, Tokai Works, Tokai, Ibaraki (Japan)

    1999-03-01

    A {gamma}-{gamma} and {beta}-{gamma} coincidence measurement system was constructed for the precise determination of nuclear data, such as thermal neutron capture cross sections and {gamma}-ray emission probabilities. The validity of the system was tested by a {gamma}-{gamma} coincidence measurement with a {sup 60}Co standard source. (author)

  6. Gamma rays from Galactic pulsars

    OpenAIRE

    2014-01-01

    Gamma rays from young pulsars and milli-second pulsars are expected to contribute to the diffuse gamma-ray emission measured by the {\\it Fermi} Large Area Telescope (LAT) at high latitudes. We derive the contribution of the pulsars undetected counterpart by using information from radio to gamma rays and we show that they explain only a small fraction of the isotropic diffuse gamma-ray background.

  7. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...

  8. The shifting gamma perception

    NARCIS (Netherlands)

    Besuijen, J.

    2005-01-01

    True to life, color display and color management depend on a proper technical model of the display used. Current gamma models and fitting procedures are not accurate in modeling the lower part of the tone reproduction curve. The GOG- and GOGO-model used in color management standards tend to clip the

  9. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.;

    2007-01-01

    to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

  10. Miniature gamma-ray camera for tumor localization

    Energy Technology Data Exchange (ETDEWEB)

    Lund, J.C.; Olsen, R.W.; James, R.B.; Cross, E. [and others

    1997-08-01

    The overall goal of this LDRD project was to develop technology for a miniature gamma-ray camera for use in nuclear medicine. The camera will meet a need of the medical community for an improved means to image radio-pharmaceuticals in the body. In addition, this technology-with only slight modifications-should prove useful in applications requiring the monitoring and verification of special nuclear materials (SNMs). Utilization of the good energy resolution of mercuric iodide and cadmium zinc telluride detectors provides a means for rejecting scattered gamma-rays and improving the isotopic selectivity in gamma-ray images. The first year of this project involved fabrication and testing of a monolithic mercuric iodide and cadmium zinc telluride detector arrays and appropriate collimators/apertures. The second year of the program involved integration of the front-end detector module, pulse processing electronics, computer, software, and display.

  11. Pectin modifications: a review.

    Science.gov (United States)

    Chen, Jun; Liu, Wei; Liu, Cheng-Mei; Li, Ti; Liang, Rui-Hong; Luo, Shun-Jing

    2015-01-01

    In recent years, the interest in studying modification of pectin has increased. A number of hydroxyl and carboxyl groups distributed along the backbone as well as a certain amount of neutral sugars presented as side chains make pectin capable of preparing a broad spectrum of derivatives. By forming pectin derivatives, their properties may be modified and some other new functional properties may be created. This article attempts to review the information about various methods used for pectin modification, including substitution (alkylation, amidation, quaternization, thiolation, sulfation, oxidation, etc.), chain elongation (cross-linking and grafting) and depolymerization (chemical, physical, and enzymatic degradation). Characteristics and applications of some pectin derivatives are also presented. In addition, the safety and regulatory status of pectin and its derivatives were reviewed.

  12. Gamma-ray performance of the GAMMA-400 detector

    CERN Document Server

    Cumani, P; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Sarkar, R; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    GAMMA-400 is a new space mission, designed as a dual experiment, capable to study both high energy gamma rays (from $\\sim$100 MeV to few TeV) and cosmic rays (electrons up to 20 TeV and nuclei up to $\\sim$10$^{15}$ eV). The full simulation framework of GAMMA-400 is based on the Geant4 toolkit. The details of the gamma-ray reconstruction pipeline in the three main instruments (Tracker, Imaging Calorimeter, Homogeneous Calorimeter) will be outlined. The performance of GAMMA-400 (PSF, effective area and sensitivity) have been obtained using this framework. The most updated results on them will be shown.

  13. Measurement of {\\eta} meson production in {\\gamma}{\\gamma} interactions and {\\Gamma}({\\eta}-->{\\gamma}{\\gamma}) with the KLOE detector

    CERN Document Server

    :,; Badoni, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bossi, F; Branchini, P; Budano, A; Balkestaahl, L Caldeira; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; Di Domenico, A; Di Donato, C; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giardina, G; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Heijkenskj, L; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Longhi, I Prado; Ranieri, A; Redmer, C F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Wislicki, W; Wolke, M; Zdebik, J

    2012-01-01

    We present a measurement of {\\eta} meson production in photon-photon interactions produced by electron-positron beams colliding with \\sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the \\phi-factory DA{\\Phi}NE with an integrated luminosity of 0.24 fb^{-1}. The e^+e^- --> e^+e^-{\\eta} cross section is measured without detecting the outgoing electron and positron, selecting the decays {\\eta}-->{\\pi}^+{\\pi}^-{\\pi}^0 and {\\eta}-->{\\pi}^0{\\pi}^0{\\pi}^0. The most relevant background is due to e^+e^- --> {\\eta}{\\gamma} when the monochromatic photon escapes detection. The cross section for this process is measured as {\\sigma}(e^+e^- -->{\\eta}{\\gamma}) = (856 \\pm 8_{stat} \\pm 16_{syst}) pb. The combined result for the e^+e^- -->e^+e^-{\\eta} cross section is {\\sigma}(e^+e^- -->e^+e^-{\\eta}) = (32.72 \\pm 1.27_{stat} \\pm 0.70_{syst}) pb. From this we derive the partial width {\\Gamma}({\\eta}-->{\\gamma}{\\gamma}) = (520 \\pm 20_{stat} \\pm 13_{syst}) eV. This is in agreement with the world average and is the ...

  14. Geometrically Consistent Mesh Modification

    KAUST Repository

    Bonito, A.

    2010-01-01

    A new paradigm of adaptivity is to execute refinement, coarsening, and smoothing of meshes on manifolds with incomplete information about their geometry and yet preserve position and curvature accuracy. We refer to this collectively as geometrically consistent (GC) mesh modification. We discuss the concept of discrete GC, show the failure of naive approaches, and propose and analyze a simple algorithm that is GC and accuracy preserving. © 2010 Society for Industrial and Applied Mathematics.

  15. Neutron spectroscopy of gamma-MgH2

    Science.gov (United States)

    Kolesnikov, Alexander; Antonov, Vladimir; Efimchenko, Vadim; Granroth, Garrett; Klyamkin, S. N.; Levchenko, A. V.; Sakharov, Michael; Ren, Yang; Ramirez-Cuesta, Timmy

    2011-03-01

    Under ambient conditions, magnesium dihydride exists in two forms, alpha-MgH2 (the most stable modification) and gamma-MgH2 (a less stable modification). The alpha-phase partly transforms to gamma-MgH2 in the course of ball-milling and under high pressure and temperature. Due to the high hydrogen content of 7.6 wt.%, MgH2 has been intensively studied as a prospective material for hydrogen storage. By exposing of alpha-MgH2 to a pressure of 5 GPa and temperature 840 K, we prepared a sample, in which about 60% of the alpha-MgH2 was transformed to gamma-MgH2. We have measured inelastic neutron scattering (INS) spectra of both the high pressure treated MgH2 and starting alpha-MgH2, and extracted the spectrum for gamma-MgH2. The differences between the INS spectra and their agreement with the first-principles calculations for these compounds will be discussed.

  16. Gamma radiation effects on polymeric materials and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Barrera D, C. E. (ed.); Martinez B, G. (ed.) [Universidad Autonoma del Estado de Mexico, Paseo Colon Interseccion Paseo Tollocan, Toluca 50120, Estado de Mexico (Mexico)

    2009-07-01

    This book provides a comprehensive study of the effects of gamma irradiation on polymeric materials and the principal applications. The eight chapters cover a broad range of synthesis and modification applications, from polymerization of metal methacrylates, copolymer films, and organometallic catalysts to the modification of nylons, functionalism of polyethylene, and improvement of polymer concrete, as well as a thorough explanation of the principles. The nature of gamma-initiated polymerization makes it a good method for polymers, as well as graft and block copolymers. Metal methacrylates have been made for use as metal sorbents in wastewater remediation and water treatment. Likewise, metal polyethylene copolymers have been synthesized for use as catalytic surfaces. The synthesis of stimuli-response graft copolymers for sensitive coatings can be well controlled. Gamma irradiation is also used for modification of bonds through functionalism and crosslinking. In polymer-reinforced concrete, irradiation both crosslinks the polymer and enhances bonding between the resin and mineral components. It improves compatibility and bonding in polyethylene rubber composites. It can be used to increase crosslinks in a polymer or polymer matrix to improve strength or hardness. In view of these considerations, this book would be a very useful source of information to scientists, engineers and postgraduate students alike. (Author)

  17. Precise measurement of {gamma}(K{yields}e {nu}({gamma}))/{gamma}(K{yields}{mu} {nu}({gamma})) and study of K{yields}e {nu} {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosino, F.; Massarotti, P.; Meola, S.; Napolitano, M. [Dipartimento di Scienze Fisiche dell' Universita ' ' Federico II' ' , Napoli (Italy); INFN Sezione di Napoli, Napoli (Italy); Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bloise, C.; Bossi, F.; Capon, G.; Capussela, T.; Ciambrone, P.; De Lucia, E.; De Simone, P.; Dreucci, M.; Felici, G.; Gatti, C.; Giovannella, S.; Jacewicz, M.; Lanfranchi, G.; Miscetti, S.; Moulson, M.; Murtas, F.; Palutan, M.; Santangelo, P.; Sciascia, B.; Sibidanov, A.; Spadaro, T.; Venanzoni, G. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Archilli, F. [Dipartimento di Fisica dell' Universita ' ' Tor Vergata' ' , Rome (Italy); INFN Sezione di Roma Tor Vergata, Rome (Italy); Beltrame, P.; Denig, A.; Mueller, S. [Johannes Gutenberg-Universitaet, Institut fuer Kernphysik, Mainz (Germany); Bini, C.; De Santis, A.; De Zorzi, G.; Di Domenico, A.; Fiore, S.; Franzini, P.; Gauzzi, P. [Dipartimento di Fisica dell' Universita ' ' La Sapienza' ' , Rome (Italy); INFN Sezione di Roma, Rome (Italy); Bocchetta, S.; Ceradini, F.; Di Micco, B.; Nguyen, F. [Dipartimento di Fisica dell' Universita ' ' Roma Tre' ' , Rome (Italy); INFN Sezione di Roma Tre, Rome (Italy); Branchini, P.; Graziani, E.; Passeri, A.; Tortora, L. [INFN Sezione di Roma Tre, Rome (Italy); Capriotti, D. [Dipartimento di Fisica dell' Universita ' ' Roma Tre' ' , Rome (Italy); Di Donato, C. [INFN Sezione di Napoli, Napoli (Italy); Kulikov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Lee-Franzini, J. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); State University of New York, Physics Department, Stony Brook (United States); Martini, M.; Patera, V.; Versaci, R. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dipartimento di Energetica dell' Universita ' ' La Sapienza' ' , Rome (Italy); Valente, P. [INFN Sezione di Roma, Rome (Italy)

    2009-12-15

    We present a precise measurement of the ratio R{sub K}={gamma}(K{yields}e{nu}({gamma}))/{gamma}(K{yields}{mu}{nu}({gamma})) and a study of the radiative process K{yields}e{nu}{gamma}, performed with the KLOE detector. The results are based on data collected at the Frascati e{sup +}e{sup -} collider DA {phi}NE for an integrated luminosity of 2.2 fb{sup -1}. We find R{sub K}=(2.493{+-}0.025{sub stat}{+-}0.019{sub syst}) x 10{sup -5}, in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation. We also measured the differential decay rate d {gamma}(K{yields}e{nu}{gamma})/dE{sub {gamma}} for photon energies 10gamma}}<250 MeV. Results are compared with predictions from theory. (orig.)

  18. Spectroscopy of a Gamma Irradiated Poly(Acrylic Acid)-Clotrimazole System

    Institute of Scientific and Technical Information of China (English)

    M.Todica; C.V.Pop; Luciana Udrescu; Traian Stefan

    2011-01-01

    A poly(acrylic acid)-clotrimazole system,gamma irradiated at different doses,is investigated by Raman spectroscopy.Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy,whereas the spectrum of clotrimazole remains unaffected at these doses of radiation.These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.%A poly(acrylic acid)-clotrimazole system, gamma irradiated at different doses, is investigated by Raman spec-troscopy. Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy, whereas the spectrum of clotrimazole remains unaffected at these doses of radiation. These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.

  19. Genetic modification and genetic determinism.

    Science.gov (United States)

    Resnik, David B; Vorhaus, Daniel B

    2006-06-26

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

  20. Interferon Gamma in Leishmaniasis

    OpenAIRE

    2013-01-01

    Leishmaniasis is a complex disease that is caused by parasites of the Leishmania genus. Leishmania are further classified into several complexes, each of which can engage in distinct interactions with mammalian hosts resulting in differing disease presentations. It is therefore not unexpected that host immune responses to Leishmania are variable. The induction of interferon gamma (IFN-γ) and response to it in these infections has received considerable attention. In this review, we summarize o...

  1. NIF Gamma Reaction History

    Science.gov (United States)

    Herrmann, H. W.; Kim, Y.; Young, C. S.; Mack, J. M.; McEvoy, A. M.; Hoffman, N. M.; Wilson, D. C.; Langenbrunner, J. R.; Evans, S.; Batha, S. H.; Stoeffl, W.; Lee, A.; Horsfield, C. J.; Rubery, M.; Miller, E. K.; Malone, R. M.; Kaufman, M. I.

    2010-11-01

    The primary objective of the NIF Gamma Reaction History (GRH) diagnostics is to provide bang time and burn width information based upon measurement of fusion gamma-rays. This is accomplished with energy-thresholded Gas Cherenkov detectors that convert MeV gamma-rays into UV/visible photons for high-bandwidth optical detection. In addition, the GRH detectors can perform γ-ray spectroscopy to explore other nuclear processes from which additional significant implosion parameters may be inferred (e.g., plastic ablator areal density). Implementation is occurring in 2 phases: 1) four PMT-based channels mounted to the outside of the NIF target chamber at ˜6 m from TCC (GRH-6m) for the 3e13-3e16 DT neutron yield range expected during the early ignition-tuning campaigns; and 2) several channels located just inside the target bay shield wall at ˜15 m from TCC (GRH-15m) with optical paths leading through the wall into well-shielded streak cameras and PMTs for the 1e16-1e20 yield range expected during the DT ignition campaign. This suite of diagnostics will allow exploration of interesting γ-ray physics well beyond the ignition campaign. Recent data from OMEGA and NIF will be shown.

  2. Transient liquid phase bonding of a third generation gamma-titanium aluminum alloy: Gamma Met PX

    Science.gov (United States)

    Butts, Daniel A.

    The research work presented here discusses transient liquid phase (TLP) bonding of a current (i.e. third) generation gamma-TiAl alloy known as Gamma Met PX (GMPX). Effective implementation of GMPX in service is likely to require fabrication of complicated geometries for which a high performance metallurgical joining technique must be developed. Although a number of joining processes have been investigated, all have significant disadvantages that limit their ability to achieve sound joints. TLP bonding has proved to be a successful method of producing joints with microstructures and compositions similar to that of the bulk substrates. Hence, bonds with parent-like mechanical and oxidation properties are possible. The interlayer and bonding conditions employed for joining of GMPX were based on successful wide-gap TLP joining trials of an earlier generation cast gamma-TiAl alloy with a composition of Ti-48Al-2Cr-2Nb in atomic percent (abbreviated here to 48-2-2). A composite interlayer consisting of a 6:1 weight ratio (7 vol.% copper) of gas atomized 48-2-2 powders (-270 mesh) and pure copper powders (-325 mesh) was employed. When applied to GMPX, these interlayer ratio and bonding conditions produced undesirable microstructures and poor mechanical performance in as-bonded joints. Thus, modifications to the joining technique were required. Initially these modifications were based purely on empirical and phenomenological studies, however, detailed mechanistic studies of the underlying joining mechanisms were conducted to aid in selecting these modifications. Mechanisms such as diffusion, solubility and wettability of copper in/on GMPX and 48-2-2 bulk substrates were investigated and compared. A difference in solubility of copper in GMPX and 48-2-2 bulk substrates was attributed to (at least in part) to the observed differences in GMPX and 48-2-2 bonds. The copper solubility, at the bonding temperature, in the 48-2-2 and GMPX alloys was determined to be ˜2 at.% and ˜1

  3. Probing cluster environments of blazars through gamma-gamma absorption

    CERN Document Server

    Sushch, Iurii

    2014-01-01

    Most blazars are known to be hosted in giant elliptic galaxies, but their cluster environments have not been thoroughly investigated. Cluster environments may contain radiation fields of low-energy photons created by nearby galaxies and/or stars in the intracluster medium that produce diffuse intracluster light. These radiation fields may absorb very high energy gamma rays ($E\\gtrsim100$ GeV; VHE) and trigger pair cascades with further production of subsequent generations of gamma rays with lower energies via inverse Compton scattering on surrounding radiation fields leaving a characteristic imprint in the observed spectral shape. The change of the spectral shape of the blazar reflects the properties of its ambient medium. We show, however, that neither intracluster light nor the radiation field of an individual nearby galaxy can cause substantial gamma-gamma absorption. Substantial gamma-gamma absorption is possible only in the case of multiple, $\\gtrsim5$, luminous nearby galaxies. This situation is not fou...

  4. Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes

    CERN Document Server

    Marisaldi, M; Trois, A; Giuliani, A; Tavani, M; Labanti, C; Fuschino, F; Bulgarelli, A; Longo, F; Barbiellini, G; Del Monte, E; Moretti, E; Trifoglio, M; Costa, E; Caraveo, P; Cattaneo, P W; Chen, A; D'Ammando, F; De Paris, G; Di Cocco, G; Di Persio, G; Donnarumma, I; Evangelista, Y; Feroci, M; Ferrari, A; Fiorini, M; Froysland, T; Galli, M; Gianotti, F; Lapshov, I; Lazzarotto, F; Lipari, P; Mereghetti, S; Morselli, A; Pacciani, L; Pellizzoni, A; Perotti, F; Picozza, P; Piano, G; Pilia, M; Prest, M; Pucella, G; Rapisarda, M; Rappoldi, A; Rubini, A; Sabatini, S; Soffitta, P; Striani, E; Vallazza, E; Vercellone, S; Vittorini, V; Zambra, A; Zanello, D; Antonelli, L A; Colafrancesco, S; Cutini, S; Giommi, P; Lucarelli, F; Pittori, C; Santolamazza, P; Verrecchia, F; Salotti, L; 10.1103/PhysRevLett.105.128501

    2010-01-01

    Terrestrial Gamma-Ray Flashes (TGFs) are very short bursts of high energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of 5-10 degrees at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the sub-satellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

  5. Neutronic Analyses in Support of the HFIR Beamline Modifications and Lifetime Extension

    Science.gov (United States)

    Remec, I.; Blakeman, E. D.

    2009-08-01

    At the High Flux Isotope Reactor, in operation since 1966 at the Oak Ridge National Laboratory, a larger HB-2 beam tube was installed to enhance capabilities for neutron science research. Neutronic analyses, including dosimetry measurements, radiation transport simulations, and simultaneous neutron and gamma spectrum adjustment calculations, performed to assess the impact of modifications on the PV lifetime are presented.

  6. Murine concanavalin A-induced hepatitis is prevented by interleukin 12 (IL-12) antibody and exacerbated by exogenous IL-12 through an interferon-gamma-dependent mechanism

    DEFF Research Database (Denmark)

    Nicoletti, F; Di Marco, R; Zaccone, P;

    2000-01-01

    and anti-IL-12 mAb were associated with profound and reverse modifications of a ConA-induced increase in the circulating levels of IL-4, IL-6, interferon gamma (IFN-gamma) and tumor necrosis factor (TNF). Relative to control animals receiving ConA alone, the plasma levels of these cytokines were all...

  7. Gamma Oscillations and Visual Binding

    Science.gov (United States)

    Robinson, Peter A.; Kim, Jong Won

    2006-03-01

    At the root of visual perception is the mechanism the brain uses to analyze features in a scene and bind related ones together. Experiments show this process is linked to oscillations of brain activity in the 30-100 Hz gamma band. Oscillations at different sites have correlation functions (CFs) that often peak at zero lag, implying simultaneous firing, even when conduction delays are large. CFs are strongest between cells stimulated by related features. Gamma oscillations are studied here by modeling mm-scale patchy interconnections in the visual cortex. Resulting predictions for gamma responses to stimuli account for numerous experimental findings, including why oscillations and zero-lag synchrony are associated, observed connections with feature preferences, the shape of the zero-lag peak, and variations of CFs with attention. Gamma waves are found to obey the Schroedinger equation, opening the possibility of cortical analogs of quantum phenomena. Gamma instabilities are tied to observations of gamma activity linked to seizures and hallucinations.

  8. The GAMMA-400 Space Mission

    CERN Document Server

    Cumani, P; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    GAMMA-400 is a new space mission which will be installed on board the Russian space platform Navigator. It is scheduled to be launched at the beginning of the next decade. GAMMA-400 is designed to study simultaneously gamma rays (up to 3 TeV) and cosmic rays (electrons and positrons from 1 GeV to 20 TeV, nuclei up to 10$^{15}$-10$^{16}$ eV). Being a dual-purpose mission, GAMMA-400 will be able to address some of the most impelling science topics, such as search for signatures of dark matter, cosmic-rays origin and propagation, and the nature of transients. GAMMA-400 will try to solve the unanswered questions on these topics by high-precision measurements of the Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission and the spectra of cosmic-ray electrons + positrons and nuclei, thanks to excellent energy and angular resolutions.

  9. Enzymatic Modification of Sphingomyelin

    DEFF Research Database (Denmark)

    Due to its major role in maintaining the water-retaining properties of the epidermis, ceramide is of great commercial potential in cosmetic and pharmaceuticals such as hair and skin care products. Currently, chemical synthesis of ceramide is a costly process, and developments of alternative cost......-efficient, high yield production methods are of great interest. In the present study, the potential of producing ceramide through the enzymatic hydrolysis of sphingomyelin have been studied. sphingomyelin is a ubiquitous membrane-lipid and rich in dairy products or by-products. It has been verified...... that sphingomyelin modification gives a feasible approach to the potential production of ceramide. The reaction system has been improved through system evaluation and the optimization of several important factors, and phospholipase C from Clostridium perfringens shows higher activity towards the hydrolysis reaction...

  10. End Group Modification

    DEFF Research Database (Denmark)

    Jahnsen, Rasmus O; Sandberg-Schaal, Anne; Frimodt-Møller, Niels

    2015-01-01

    Increased incidence of infections with multidrug-resistant bacterial strains warrants an intensive search for novel potential antimicrobial agents. Here, an antimicrobial peptide analogue with a cationic/hydrophobic alternating design displaying only moderate activity against Gram-positive pathog......Increased incidence of infections with multidrug-resistant bacterial strains warrants an intensive search for novel potential antimicrobial agents. Here, an antimicrobial peptide analogue with a cationic/hydrophobic alternating design displaying only moderate activity against Gram......-positive pathogens was optimized. Generally, introduction of hydrophobic moieties at the N-terminus resulted in analogues with remarkably increased activity against multidrug-resistant Staphylococcus aureus and Enterococcus faecium. Interestingly, the potency against Escherichia coli strains was unaffected, whereas...... modification with hydrophobic moieties led to increased activity towards the Gram-negative Acinetobacter baumannii. Despite increased cytotoxicity against murine fibroblasts and human umbilical vein endothelial cells, the optimized peptide analogues exhibited significantly improved cell selectivity. Overall...

  11. Surface modification technology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wonbaek; Yu, Hyosin; Chung, Inwha; Rhee, Kang In; Choi, Good Sun; Lee, Chulkyung; Youn, In Ju; Chung, Jinki; Suh, Chang Youl; Yang, Dong Hyo [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    Domestic production of rare metals has not been achieved due to the low metal content in their ores in the nation. For these reasons, a strategy for the value addition of rare metal sponges by processes like vacuum melting should be seek to meet the growing domestic demand for titanium metals and alloys. However, current domestic market appears not to be sufficient enough for the large scale investment for the expensive vacuum-melting equipment. Besides, related ingot-processing technologies like rolling, extrusion, and forging of titanium should be prepared in advance. In the mean time, the attempt to recycle expensive titanium scraps produced in our nation would be worthwhile in view of the reduction of import from foreign countries and of saving valuable secondary resources. The objectives for this research is to develop a multipurpose inductively-coupled plasma enhanced-surface modification (ICPESM) process to upgrade powder products. Stable plasma was obtained by the impedance harmonization between plasma generator and matching networks maintaining the reflected power at near zero. The chamber vacuum went down to 10{sup -3} torr offering no difficulties to maintain 1.0 torr at which the present experiments were conducted. However, the fluidization in the chamber was unstable when operated in vacuum. The gas distributor and chamber design may need modifications. Argon plasma treatment on the titanium powders changed the surface morphology slightly even though the effect was not significant due possibly to the short treatment duration of 60 minutes. Oxygen plasma oxidized the surface of titanium powders to TiO{sub 2} as confirmed by XRD. The carbon black powders were clustered during oxidation treatment by the fluidization or surface activation by the high power of low temperature plasma. (author). 4 tabs., 15 figs.

  12. Applied gamma-ray spectrometry

    CERN Document Server

    Dams, R; Crouthamel, Carl E

    1970-01-01

    Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

  13. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  14. Observation of in-medium modifications of the omega meson.

    Science.gov (United States)

    Trnka, D; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Kotulla, M; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch

    2005-05-20

    The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction gamma + A --> omega + X --> pi(0)gamma + X('). Results obtained for Nb are compared to a reference measurement on a LH2 target. While for recoiling, long-lived mesons (pi(0), eta, and eta;(')), which decay outside of the nucleus, a difference in the line shape for the two data samples is not observed, we find a significant enhancement towards lower masses for omega mesons produced on the Nb target. For momenta less than 500 MeV/c an in-medium omega meson mass of M(medium) = [722(+4)(-4)(stat)+35-5(syst)] MeV/c(2) has been deduced at an estimated average nuclear density of 0.6rho(0).

  15. Genetic modification and genetic determinism

    OpenAIRE

    Vorhaus Daniel B; Resnik David B

    2006-01-01

    Abstract In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound....

  16. Search for C-parity violation in $J/ \\psi \\to \\gamma\\gamma$ and $ \\gamma \\phi$

    CERN Document Server

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Bondarenko, O; Boyko, I; Braun, S; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Chu, Y P; Cibinetto, G; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Du, S X; Fan, J Z; Fang, J; Fang, S S; Fang, Y; Fava, L; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fu, C D; Gao, Q; Gao, Y; Garzia, I; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, T; Guo, Y P; Haddadi, Z; Han, S; Han, Y L; Harris, F A; He, K L; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, G S; Huang, H P; Huang, J S; Huang, X T; Huang, Y; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L L; Jiang, L W; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kuehn, W; Kupsc, A; Lai, W; Lange, J S; Lara, M; Larin, P; Leyhe, M; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, Jin; Li, K; Li, Q J; Li, T; Li, W D; Li, W G; Li, X H; Li, X L; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Lin, D X; Liu, B J; Liu, C L; Liu, C X; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H M; Liu, J; Liu, J P; Liu, K; Liu, K Y; Liu, Q; Liu, S B; Liu, X; Liu, X X; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, R Q; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Lyu, X R; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Moeini, H; Morales, C Morales; Moriya, K; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Pu, Y N; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ren, H L; Ripka, M; Rong, G; Ruan, X D; Santoro, V; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, W M; Song, X Y; Sosio, S; Spataro, S; Spruck, B; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Toth, D; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q J; Wang, S G; Wang, W; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Werner, M; Wiedner, U; Wolke, M; Wu, L H; Wu, Z; Xia, L G; Xia, Y; Xiao, D; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Xue, Z; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H X; Yang, L; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, H W; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J J; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, L; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhou, L; Zhou, Li; Zhou, X; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

    2014-01-01

    Using $1.06\\times10^8$ $\\psi(3686)$ events recorded in $e^{+}e^{-}$ collisions at $\\sqrt{s}=$ 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in $J/\\psi \\to \\gamma\\gamma$ and $ \\gamma \\phi$ decays via $\\psi(3686) \\to J/\\psi \\pi^+\\pi^-$. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be $\\mathcal{B}(J/\\psi \\to \\gamma\\gamma) < 2.7 \\times 10^{-7}$ and $\\mathcal{B}(J/\\psi \\to \\gamma\\phi) < 1.4 \\times 10^{-6}$ at the 90\\% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.

  17. Determination of the $e^+ e^- \\to \\gamma \\gamma (\\gamma)$ cross-section at LEP 2

    CERN Document Server

    Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, B P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L; Murray, W; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, R; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Pozdnyakov, V; Pukhaeva, N; Pullia, Antonio; Rames, J; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Sander, C; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W A; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M

    2004-01-01

    A test of the benchmark QED process e+e- -> gamma gamma (gamma) is reported, using the data collected with the DELPHI detector at LEP 2. The data analysed were recorded at centre-of-mass energies ranging from 161 GeV to 208 GeV and correspond to a total integrated luminosity of 656.4 pb^{-1}. The Born cross-section for the process e+e- -> gamma gamma (gamma) was determined, confirming the validity of QED at the highest energies ever attained in electron-positron collisions. Lower limits on the parameters of a number of possible deviations from QED, predicted within theoretical frameworks expressing physics beyond the Standard Model, were derived.

  18. Digital gamma-gamma coincidence HPGe system for environmental analysis

    DEFF Research Database (Denmark)

    Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

    2017-01-01

    The performance of a new gamma-gamma coincidence spectrometer system for environmental samples analysis at the Center for Nuclear Technologies of the Technical University of Denmark (DTU) is reported. Nutech Coincidence Low Energy Germanium Sandwich (NUCLeGeS) system consists of two HPGe detector...

  19. Advantages of exclusive \\gamma\\gamma production to probe high mass systems

    CERN Document Server

    Martin, A D

    2016-01-01

    We recall that the exclusive production of high mass objects via \\gamma\\gamma fusion at the LHC is not strongly suppressed in comparison with inclusive \\gamma\\gamma fusion. Therefore it may be promising to study new objects produced by the \\gamma\\gamma subprocess in experiments with exclusive kinematics. We list the main advantages of exclusive experiments.

  20. The GAMMA-400 Space Experiment: Gammas, Electrons and Nuclei Measurements

    Science.gov (United States)

    Mocchiutti, E.; Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Carbone, R.; Cumani, P.; Fradkin, M. I.; Gusakov, Yu. V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu.; Papini, P.; Picozza, P.; Rodin, V. G.; Runtso, M. F.; Sarkar, R.; Sparvoli, R.; Spillantini, P.; Suchkov, S. I.; Tavani, M.; Topchiev, N. P.; Vacchi, A.; Vannuccini, E.; Yurkin, Yu. T.; Zampa, N.; Zverev, V. G.; Zirakashvili, V. N.

    2013-06-01

    The present design of the new space gamma-ray telescope GAMMA-400 for the energy range 50 MeV-3 TeV is presented. The proposed instrument has an angular resolution of 1-2 degrees at E(γ)˜100 MeV and ˜0.01 degrees at E(γ)>100 GeV and an energy resolution ˜1% at E(γ)>100 GeV. By means of a deep segmented calorimeter high energy electron flux can be studied, with a proton rejection factor of about 106. The GAMMA-400 experiment is optimized to address a broad range of science topics, such as search for signatures of dark matter, studies of galactic and extragalactic gamma-ray sources, galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of high energy electrons, protons and nuclei up to the knee.

  1. Effects of gamma irradiation on deteriorated paper

    Science.gov (United States)

    Bicchieri, Marina; Monti, Michela; Piantanida, Giovanna; Sodo, Armida

    2016-08-01

    Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State (http://www.icpal.beniculturali.it/allegati/DM-7

  2. Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the gamma-gamma opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to $\\gamma\\gamma$ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the gamma-ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the cen...

  3. Colliding. gamma. e and. gamma gamma. beams from single-pass e/sup +/e/sup -/ accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Tel' nov, V.I.

    1983-08-01

    A detailed discussion is given of the main characteristics of ..gamma..e and ..gamma gamma.. collisions in the scheme previously proposed by the authors for obtaining colliding ..gamma..e and ..gamma gamma.. beams on the basis of the planned linear accelerators with e/sup +/e/sup -/ colliding beams VLEPP and SLC. It is proposed to obtain intense ..gamma.. beams with energy ..omega..approx.E/sub e/> or =50 GeV by scattering of laser light focused onto the electron beams of these accelerators. In the case when the maximum luminosity is achieved, L/sub gammae/approx.L/sub e/e or L/sub gammagamma/approx.L/sub e/e, the distribution of the luminosity in the invariant mass of the ..gamma..e or ..gamma gamma.. system is broad. Monochromatization of the collisions to a level 5--10% is possible. It involves a decrease of luminosity and is most efficient for use of electrons and laser photons with helicities of opposite sign. Examples of interesting physics problems for the proposed ..gamma..e and ..gamma gamma.. beams are given.

  4. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  5. Surface modification of cellulose nanocrystals

    Science.gov (United States)

    Eyley, Samuel; Thielemans, Wim

    2014-06-01

    Chemical modification of cellulose nanocrystals is an increasingly popular topic in the literature. This review analyses the type of cellulose nanocrystal modification reactions that have been published in the literature thus far and looks at the steps that have been taken towards analysing the products of the nanocrystal modifications. The main categories of reactions carried out on cellulose nanocrystals are oxidations, esterifications, amidations, carbamations and etherifications. More recently nucleophilic substitutions have been used to introduce more complex functionality to cellulose nanocrystals. Multi-step modifications are also considered. This review emphasizes quantification of modification at the nanocrystal surface in terms of degree of substitution and the validity of conclusions drawn from different analysis techniques in this area. The mechanisms of the modification reactions are presented and considered with respect to the effect on the outcome of the reactions. While great strides have been made in the quality of analytical data published in the field of cellulose nanocrystal modification, there is still vast scope for improvement, both in data quality and the quality of analysis of data. Given the difficulty of surface analysis, cross-checking of results from different analysis techniques is fundamental for the development of reliable cellulose nanocrystal modification techniques.

  6. Surface Modification of Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Qi Huang

    2016-01-01

    Full Text Available Objective: This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs. Data Sources: All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect. Study Selection: The articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded. Results: Technology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol, polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO 2 , heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments. Conclusion: The surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs.

  7. AGATA - Advanced Gamma Tracking Array

    CERN Document Server

    Akkoyun, S; Alikhani, B; Ameil, F; de Angelis, G; Arnold, L; Astier, A; Ataç, A; Aubert, Y; Aufranc, C; Austin, A; Aydin, S; Azaiez, F; Badoer, S; Balabanski, D L; Barrientos, D; Baulieu, G; Baumann, R; Bazzacco, D; Beck, F A; Beck, T; Bednarczyk, P; Bellato, M; Bentley, M A; Benzoni, G; Berthier, R; Berti, L; Beunard, R; Bianco, G Lo; Birkenbach, B; Bizzeti, P G; Bizzeti-Sona, A M; Blanc, F Le; Blasco, J M; Blasi, N; Bloor, D; Boiano, C; Borsato, M; Bortolato, D; Boston, A J; Boston, H C; Bourgault, P; Boutachkov, P; Bouty, A; Bracco, A; Brambilla, S; Brawn, I P; Brondi, A; Broussard, S; Bruyneel, B; Bucurescu, D; Burrows, I; Bürger, A; Cabaret, S; Cahan, B; Calore, E; Camera, F; Capsoni, A; Carrió, F; Casati, G; Castoldi, M; Cederwall, B; Cercus, J -L; Chambert, V; Chambit, M El; Chapman, R; Charles, L; Chavas, J; Clément, E; Cocconi, P; Coelli, S; Coleman-Smith, P J; Colombo, A; Colosimo, S; Commeaux, C; Conventi, D; Cooper, R J; Corsi, A; Cortesi, A; Costa, L; Crespi, F C L; Cresswell, J R; Cullen, D M; Curien, D; Czermak, A; Delbourg, D; Depalo, R; Descombes, T; Désesquelles, P; Detistov, P; Diarra, C; Didierjean, F; Dimmock, M R; Doan, Q T; Domingo-Pardo, C; Doncel, M; Dorangeville, F; Dosme, N; Drouen, Y; Duchêne, G; Dulny, B; Eberth, J; Edelbruck, P; Egea, J; Engert, T; Erduran, M N; Ertürk, S; Fanin, C; Fantinel, S; Farnea, E; Faul, T; Filliger, M; Filmer, F; Finck, Ch; de France, G; Gadea, A; Gast, W; Geraci, A; Gerl, J; Gernhäuser, R; Giannatiempo, A; Giaz, A; Gibelin, L; Givechev, A; Goel, N; González, V; Gottardo, A; Grave, X; Grȩbosz, J; Griffiths, R; Grint, A N; Gros, P; Guevara, L; Gulmini, M; Görgen, A; Ha, H T M; Habermann, T; Harkness, L J; Harroch, H; Hauschild, K; He, C; Hernández-Prieto, A; Hervieu, B; Hess, H; Hüyük, T; Ince, E; Isocrate, R; Jaworski, G; Johnson, A; Jolie, J; Jones, P; Jonson, B; Joshi, P; Judson, D S; Jungclaus, A; Kaci, M; Karkour, N; Karolak, M; Kaşkaş, A; Kebbiri, M; Kempley, R S; Khaplanov, A; Klupp, S; Kogimtzis, M; Kojouharov, I; Korichi, A; Korten, W; Kröll, Th; Krücken, R; Kurz, N; Ky, B Y; Labiche, M; Lafay, X; Lavergne, L; Lazarus, I H; Leboutelier, S; Lefebvre, F; Legay, E; Legeard, L; Lelli, F; Lenzi, S M; Leoni, S; Lermitage, A; Lersch, D; Leske, J; Letts, S C; Lhenoret, S; Lieder, R M; Linget, D; Ljungvall, J; Lopez-Martens, A; Lotodé, A; Lunardi, S; Maj, A; van der Marel, J; Mariette, Y; Marginean, N; Marginean, R; Maron, G; Mather, A R; Mȩczyński, W; Mendéz, V; Medina, P; Melon, B; Menegazzo, R; Mengoni, D; Merchan, E; Mihailescu, L; Michelagnoli, C; Mierzejewski, J; Milechina, L; Million, B; Mitev, K; Molini, P; Montanari, D; Moon, S; Morbiducci, F; Moro, R; Morrall, P S; Möller, O; Nannini, A; Napoli, D R; Nelson, L; Nespolo, M; Ngo, V L; Nicoletto, M; Nicolini, R; Noa, Y Le; Nolan, P J; Norman, M; Nyberg, J; Obertelli, A; Olariu, A; Orlandi, R; Oxley, D C; Özben, C; Ozille, M; Oziol, C; Pachoud, E; Palacz, M; Palin, J; Pancin, J; Parisel, C; Pariset, P; Pascovici, G; Peghin, R; Pellegri, L; Perego, A; Perrier, S; Petcu, M; Petkov, P; Petrache, C; Pierre, E; Pietralla, N; Pietri, S; Pignanelli, M; Piqueras, I; Podolyak, Z; Pouhalec, P Le; Pouthas, J; Pugnére, D; Pucknell, V F E; Pullia, A; Quintana, B; Raine, R; Rainovski, G; Ramina, L; Rampazzo, G; La Rana, G; Rebeschini, M; Recchia, F; Redon, N; Reese, M; Reiter, P; Regan, P H; Riboldi, S; Richer, M; Rigato, M; Rigby, S; Ripamonti, G; Robinson, A P; Robin, J; Roccaz, J; Ropert, J -A; Rossé, B; Alvarez, C Rossi; Rosso, D; Rubio, B; Rudolph, D; Saillant, F; Şahin, E; Salomon, F; Salsac, M -D; Salt, J; Salvato, G; Sampson, J; Sanchis, E; Santos, C; Schaffner, H; Schlarb, M; Scraggs, D P; Seddon, D; Şenyiğit, M; Sigward, M -H; Simpson, G; Simpson, J; Slee, M; Smith, J F; Sona, P; Sowicki, B; Spolaore, P; Stahl, C; Stanios, T; Stefanova, E; Stézowski, O; Strachan, J; Suliman, G; Söderström, P -A; Tain, J L; Tanguy, S; Tashenov, S; Theisen, Ch; Thornhill, J; Tomasi, F; Toniolo, N; Touzery, R; Travers, B; Triossi, A; Tripon, M; Tun-Lanoë, K M M; Turcato, M; Unsworth, C; Ur, C A; Valiente-Dobon, J J; Vandone, V; Vardaci, E; Venturelli, R; Veronese, F; Veyssiere, Ch; Viscione, E; Wadsworth, R; Walker, P M; Warr, N; Weber, C; Weisshaar, D; Wells, D; Wieland, O; Wiens, A; Wittwer, G; Wollersheim, H J; Zocca, F; Zamfir, N V; Ziȩbliński, M; Zucchiatti, A

    2011-01-01

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorith...

  8. Genetic modification and genetic determinism

    Directory of Open Access Journals (Sweden)

    Vorhaus Daniel B

    2006-06-01

    Full Text Available Abstract In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

  9. Chemical Protein Modification through Cysteine.

    Science.gov (United States)

    Gunnoo, Smita B; Madder, Annemieke

    2016-04-01

    The modification of proteins with non-protein entities is important for a wealth of applications, and methods for chemically modifying proteins attract considerable attention. Generally, modification is desired at a single site to maintain homogeneity and to minimise loss of function. Though protein modification can be achieved by targeting some natural amino acid side chains, this often leads to ill-defined and randomly modified proteins. Amongst the natural amino acids, cysteine combines advantageous properties contributing to its suitability for site-selective modification, including a unique nucleophilicity, and a low natural abundance--both allowing chemo- and regioselectivity. Native cysteine residues can be targeted, or Cys can be introduced at a desired site in a protein by means of reliable genetic engineering techniques. This review on chemical protein modification through cysteine should appeal to those interested in modifying proteins for a range of applications.

  10. RNA modification in Cajal bodies.

    Science.gov (United States)

    Meier, U Thomas

    2016-10-24

    Aside from nucleoli, Cajal bodies (CBs) are the best-characterized organelles of mammalian cell nuclei. Like nucleoli, CBs concentrate ribonucleoproteins (RNPs), in particular, spliceosomal small nuclear RNPs (snRNPs) and small nucleolar RNPs (snoRNPs). In one of the best-defined functions of CBs, most of the snoRNPs are involved in site-specific modification of snRNAs. The two major modifications are pseudouridylation and 2'-O-methylation that are guided by the box H/ACA and C/D snoRNPs, respectively. This review details the modifications, their function, the mechanism of modification, and the machineries involved. We dissect the different classes of noncoding RNAs that meet in CBs, guides and substrates. Open questions and conundrums, often raised and appearing due to experimental limitations, are pointed out and discussed. The emphasis of the review is on mammalian CBs and their function in modification of noncoding RNAs.

  11. CIENCIA Y TECNOLOGÍA EN LOS TELEDIARIOS COLOMBIANOS: SOBRE LO QUE SE CUBRE Y NO SE CUBRE

    Directory of Open Access Journals (Sweden)

    Tania Arboleda Castrillón

    Full Text Available En este artículo, analizamos un corpus de noticias de ciencia y tecnología emitidas por el telediario Noticias Caracol - el de mayor rating en Colombia. Este trabajo atiende el doble objetivo de verificar si la demanda de los colombianos por este tipo de información es mínimamente atendida y de dar cuenta de las principales características de la cobertura de la ciencia y la tecnología en este telediario. Los resultados muestran que estos temas tienen una relativa poca relevancia en la agenda de este telediario y que los miembros del gobierno cumplen un papel preponderante, no sólo como voces, sino como fuentes en la construcción de los hechos noticiosos. También se encontró que este telediario no es necesariamente democrático a la hora de elegir sus fuentes, sus voces y sus referencias, pero además tampoco se dan elementos de contexto fuertes para estas informaciones.

  12. Pixelated gamma detector

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei Ivanovich; Yanoff, Brian David; Guida, Renato; Ivan, Adrian

    2016-12-27

    A pixelated gamma detector includes a scintillator column assembly having scintillator crystals and optical transparent elements alternating along a longitudinal axis, a collimator assembly having longitudinal walls separated by collimator septum, the collimator septum spaced apart to form collimator channels, the scintillator column assembly positioned adjacent to the collimator assembly so that the respective ones of the scintillator crystal are positioned adjacent to respective ones of the collimator channels, the respective ones of the optical transparent element are positioned adjacent to respective ones of the collimator septum, and a first photosensor and a second photosensor, the first and the second photosensor each connected to an opposing end of the scintillator column assembly. A system and a method for inspecting and/or detecting defects in an interior of an object are also disclosed.

  13. Surface modification of bioceramics

    Science.gov (United States)

    Monkawa, Akira

    Hydroxyapatite [Ca10(PO4)6(OH)2, HAp] is a major inorganic component of bone and teeth tissues and has the excellent biocompatibility and high osteoconductivity. The interactions between HAp and protein or cell have been studied. The HAp related bioceramics such as bone substitute, coating substance of metal implants, inorganic-polymer composites, and cell culture. We described two methods; (1) surface modification of HAp using organosilane; (2) fabrication of HAp ultra-thin layer on gold surface for protein adsorption analyzed with QCM-D technique. The interfacial interaction between collagen and HAp in a nano-region was controlled by depositing the organosilane of n-octadecyltrimethoxysilane (ODS: -CH3) or aminopropyltriethoxysilane (APTS: -NH2) with a chemical vapor deposition method. The morphologies of collagen adsorbed on the surfaces of HAp and HAp deposited with APTS were similar, however that of the surface with ODS was apparently different, due to the hydrophobic interaction between the organic head group of -CH3 and residual groups of collagen. We present a method for coating gold quartz crystal microbalance with dissipation (QCM-D) sensor with ultra-thin layer of hydroxyapatite nanocrystals evenly covering and tightly bound to the surface. The hydroxyapatite sensor operated in liquid with high stability and sensitivity. The in-situ adsorption mechanism and conformational change of fibrinogen on gold, titanium and hydroxyapatite surfaces were investigated by QCM-D technique and Fourier-transform infrared spectroscopy. The study indicates that the hydroxyapatite sensor is applicable for qualitative and conformational analysis of protein adsorption.

  14. Effect of gamma irradiation on HPMC/ZnO nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shivananda, C. S.; Harish, K. V.; Sangappa, E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore – 574199 (India); Shetty, G. Rajesha [Department of Physics, Government First Grade College, Hiriadka, Udupi – 576113 (India)

    2015-06-24

    The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films.

  15. System Evolution by Metalevel Modification

    Directory of Open Access Journals (Sweden)

    Michal Vagač

    2009-05-01

    Full Text Available This paper describes system evolution managed by corresponding metasystem. The metasystem builds a metamodel of base system and allows its modification. The modification is propagated back to the base system. The application model presents the example of standard graphics user interface developed with Java Abstract Windowing Toolkit (AWT, which is a part of the Java Foundation Classes (JFC. The main aim is to confirm the possibility of application properties monitoring using aspect-oriented programming, their abstraction in ametamodel, possibility of their alternations by metamodel modifications and consequent change in the original application model.

  16. $\\gamma\\gamma$ physics with the KLOE experiment

    CERN Document Server

    Archilli, F.; Badoni, D.; Balwierz, I.; Bencivenni, G.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Budano, A.; Bulychjev, S.A.; Campana, P.; Capon, G.; Ceradini, F.; Ciambrone, P.; Czerwiński, E.; Dané, E.; De Lucia, E.; De Robertis, G.; De Santis, A.; De Zorzi, G.; Di Domenico, A.; Di Donato, C.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Felici, G.; Fiore, S.; Franzini, P.; Gauzzi, P.; Giovannella, S.; Gonnella, F.; Graziani, E.; Happacher, F.; Höistad, B.; Iarocci, E.; Jacewicz, M.; Johansson, T.; Kulikov, V.; Kupsc, A.; Lee-Franzini, J.; Loddo, F.; Martemianov, M.; Martini, M.; Matsyuk, M.; Messi, R.; Miscetti, S.; Morello, G.; Moricciani, D.; Moskal, P.; Nguyen, F.; Passeri, A.; Patera, V.; Prado Longhi, I.; Ranieri, A.; Santangelo, P.; Sarra, I.; Schioppa, M.; Sciascia, B.; Sciubba, A.; Silarski, M.; Taccini, C.; Tortora, L.; Venanzoni, G.; Versaci, R.; Wiślicki, W.; Wolke, M.; Zdebik, J.

    2011-01-01

    The processes $e^+e^-\\to e^+e^-X$, with $X$ being either the $\\eta$ meson or $\\pi^0\\pi^0$, are studied at DA$\\Phi$NE, with $e^+e^-$ beams colliding at $\\sqrt{s}\\simeq1$ GeV, below the $\\phi$ resonance peak. The data sample is from an integrated luminosity of 240 pb$^{-1}$, collected by the KLOE experiment without tagging of the outgoing $e^+e^-$. Preliminary results are presented on the observation of the $\\gamma\\gamma\\to\\eta$ process, with both $\\eta\\to\\pi^+\\pi^-\\pi^0$ and $\\eta\\to\\pi^0\\pi^0\\pi^0$ channels, and the evidence for $\\gamma\\gamma\\to\\pi^0\\pi^0$ production at low $\\pi^0\\pi^0$ invariant mass.

  17. Inference on Reliability in the Gamma and Inverted Gamma Distributions

    Directory of Open Access Journals (Sweden)

    Jungsoo Woo

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} We derive distributions of ratio for two independent gamma variables and two independent inverted gamma variables and then we observe the skewness of two ratio densities. We then consider inference on reliability in two independent gamma random variables and two independent inverted gamma random variables each having known shape parameters.

  18. Total Cross Section in $\\gamma\\gamma$ Collisions at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Todorova-Nová, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ewers, A; Extermann, Pierre; Fabre, M; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M

    2001-01-01

    The reaction e+e- -> e+e- gamma* gamma* -> e+e- hadrons for quasi-real photons is studied using data from root(s) = 183 GeV up to 202 GeV. Results on the total cross sections sigma(e+e- -> e+e- hadrons) and sigma(+e- gamma* gamma* -> e+e- hadrons) are given for the two-photon centre-of-mass energies 5 GeV < Wgammagamma < 185 GeV. The total cross section of two real photons is described by a Regge parametrisation. We observe a steeper rise with the two-photon centre-of-mass energy as compared to the hadron-hadron and the photon-proton cross sections. The data are also compared to the expectations of different theoretical models.

  19. Microbiological, physico-chemical, and sensorial modifications during the useful life of the shrimps (Penaeus brasiliensis e Penaeus Paulensis) submitted to gamma radiation.; Alteracoes microbiologicas, fisico-quimicas e sensoriais durante a vida util do camarao-rosa (Penaeus brasiliensis e Penaeus Paulensis) submetido a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Mariana Del Ben

    2000-07-01

    During the last years, there has been an increase in the consumption of seafood and freshwater fish as a healthier diet option. Shrimps are the most important product in the international trade market. This kind of food easily deteriorates due to autolysis, oxidation and microbial action. This research was carried out in order to study the effectiveness of radiation in preserving shrimps. Samples of shrimps (Penaeus brasiliensis and P. paulensi) were submitted to gamma radiation doses of O kGy, 1 kGy, 2 kGy, 2.5 kGy, 3 kGy and 3.5 kGy and stored under refrigeration. The microbiological analysis was performed on days O, 2, 4, 7 10 and 14 post processing. Simultaneously, the pH and total, volatile bases (TVBN) were determined. The psychotropic population varied from <2.0 log to 8.08 log CFU/g while the mesophilic ranged from <1.0 109 to 6.03 log CFU/g; pH varied from 7.52 to 8.33 and TVBN from 28.47 to 56.00 mg N/100g, according to the radiation dose and the day of analysis. Black spots, changes in the characteristic odour and TVBN levels showed the beginning of a chemical deterioration as of the 4 th day of analysis. Doses of 3 kGy and 3.5 kGy presented the best results. Pseudomonas spp. showed the highest sensitivity to radiation. Due to the lapse of time between capturing shrimps and returning to land together with inadequate manipulation and storage in the boat, the quality of raw material is prejudiced which makes the radiation process unfeasible. (author)

  20. Light speed variation from gamma ray burst GRB 160509A

    CERN Document Server

    Xu, Haowei

    2016-01-01

    It is postulated in Einstein's relativity that the speed of light in vacuum is a constant for all observers. However, the effect of quantum gravity could bring an energy dependence of light speed. Even a tiny speed variation, when amplified by the cosmological distance, may be revealed by the observed time lags between photons with different energies from astrophysical sources. From the newly detected long gamma ray burst GRB~160509A, we find evidence to support the prediction for a linear form modification of light speed in cosmological space.

  1. Light speed variation from gamma ray burst GRB 160509A

    Directory of Open Access Journals (Sweden)

    Haowei Xu

    2016-09-01

    Full Text Available It is postulated in Einstein's relativity that the speed of light in vacuum is a constant for all observers. However, the effect of quantum gravity could bring an energy dependence of light speed. Even a tiny speed variation, when amplified by the cosmological distance, may be revealed by the observed time lags between photons with different energies from astrophysical sources. From the newly detected long gamma ray burst GRB 160509A, we find evidence to support the prediction for a linear form modification of light speed in cosmological space.

  2. Light speed variation from gamma ray burst GRB 160509A

    Science.gov (United States)

    Xu, Haowei; Ma, Bo-Qiang

    2016-09-01

    It is postulated in Einstein's relativity that the speed of light in vacuum is a constant for all observers. However, the effect of quantum gravity could bring an energy dependence of light speed. Even a tiny speed variation, when amplified by the cosmological distance, may be revealed by the observed time lags between photons with different energies from astrophysical sources. From the newly detected long gamma ray burst GRB 160509A, we find evidence to support the prediction for a linear form modification of light speed in cosmological space.

  3. Respiratory psychophysiology and behavior modification.

    Science.gov (United States)

    Ley, R

    2001-09-01

    This article was written as an introduction to a special issue of Behavior Modification dedicated to studies in the field of respiratory psychophysiology. Although the invited articles that constitute this special issue cover a fairly broad range of topics, priority was given to articles that focus on the role of respiration in panic disorder. Attention is directed to the fundamental role of breathing in applied psychophysiology and to the encouragement of research in the modification of breathing behavior. The connection between respiratory psychophysiology and behavior modification is explained by reference to (a) a recent article on Pavlovian and operant control of breathing behavior and (b) four published volumes of selected articles dedicated exclusively to the field of respiratory psychophysiology. The present special issue of Behavior Modification marks the fifth volume.

  4. Search for the Radiative Decays B -> rho gamma and B0 -> omega gamma

    CERN Document Server

    Aubert, Bernard; Boutigny, D; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Robbe, P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kral, J F; Kukartsev, G; Le Clerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Romosan, A; Ronan, Michael T; Shelkov, V G; Telnov, A V; Wenzel, W A; Harrison, T J; Hawkes, C M; Knowles, D J; Penny, R C; Watson, A T; Watson, N K; Deppermann, T; Goetzen, K; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmücker, H; Steinke, M; Barlow, N R; Bhimji, W; Boyd, J T; Chevalier, N; Cottingham, W N; MacKay, C; Wilson, F F; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Chao, M; Kirkby, D; Lankford, A J; Mandelkern, M A; McMahon, S; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Schwanke, U; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Kuznetsova, N; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dorsten, M P; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Barillari, T; Blanc, F; Bloom, P; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; Van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Dubitzky, R S; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, Klaus R; Schwierz, R; Spaan, B; Wilden, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Thiebaux, C; Vasileiadis, G; Verderi, M; Khan, A; Lavin, D; Muheim, F; Playfer, S; Swain, J E; Tinslay, J; Bozzi, C; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; Falciai, D; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Pastore, F C; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Aspinwall, M L; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Morton, G W; Nash, J A; Sanders, P; Taylor, G P; Grenier, G J; Lee, S J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Bionta, R M; Brigljevic, V; Cheng, C H; Lange, D J; Wright, D M; Bevan, A J; Fry, J R; Gabathuler, Erwin; Gamet, R; Kay, M; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Bellodi, G; Harrison, P F; Shorthouse, H W; Strother, P; Vidal, P B; Cowan, G; Flächer, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, R J; Forti, A C; Hart, P A; Jackson, F; Lafferty, G D; Lyon, A J; Weatherall, J H; Williams, J C; Farbin, A; Jawahery, A; Kovalskyi, D; Laé, K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Milek, M; Patel, P M; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Hast, C; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; LoSecco, J M; Gabriel, T A; Brau, B; Pulliam, T; Brau, J E; Frey, R; Iwasaki, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; Leruste, P; Ocariz, J; Pivk, M; Roos, L; Stark, J; T'Jampens, S; Manfredi, P F; Re, V; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Varnes, E W; Bellini, F; Cavoto, G; Del Re, D; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Leonardi, E; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Serra, M; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Langer, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Convery, M R; Coupal, D P; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graugès-Pous, E; Hadig, T; Halyo, V; Hrynóva, T; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocian, M L; Langenegger, U; Leith, D W G S; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Menke, S; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Robertson, S H; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Tanaka, H A; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, Patricia R; Meyer, T I; Roat, C; Ahmed, S; Ernst, J A; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Hu, H; Johnson, J R; Liu, R; Di Lodovico, F; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; Von Wimmersperg-Töller, J H; Wu, J; Wu Sau Lan; Yu, Z; Neal, H

    2003-01-01

    A search for the exclusive radiative decays B --> rho(770) gamma and B0 --> omega(782) gamma is performed on a sample of about 84times 10^{6} Bbar B events collected by the BaBar detector at the PEP-II asymmetric-energy e+e- storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions of BR(B^0 -> rho^0 gamma) rho^+ gamma) omega gamma) rho gamma) = Gamma(B+ --> rho+ gamma) =2timesGamma(B0 --> rho0 gamma), we find the combined limit BR(B --> rho gamma) rho gamma)/BR(B --> K* gamma) < 0.047 at 90% C.L.

  5. HMG Modifications and Nuclear Function

    OpenAIRE

    Zhang, Qingchun; Wang, Yinsheng

    2010-01-01

    High mobility group (HMG) proteins assume important roles in regulating chromatin dynamics, transcriptional activities of genes and other cellular processes. Post-translational modifications of HMG proteins can alter their interactions with DNA and proteins, and consequently, affect their biological activities. Although the mechanisms through which these modifications are involved in regulating biological processes in different cellular contexts are not fully understood, new insights into the...

  6. Posttranslational Protein Modification in Archaea

    OpenAIRE

    Eichler, Jerry; Adams, Michael W. W.

    2005-01-01

    One of the first hurdles to be negotiated in the postgenomic era involves the description of the entire protein content of the cell, the proteome. Such efforts are presently complicated by the various posttranslational modifications that proteins can experience, including glycosylation, lipid attachment, phosphorylation, methylation, disulfide bond formation, and proteolytic cleavage. Whereas these and other posttranslational protein modifications have been well characterized in Eucarya and B...

  7. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Ferreto, H. F. R., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Parra, D. F., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br; Lugão, A. B., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br [Center of Chemistry and Environment, Institute of Energy and Nuclear Research - IPEN (Brazil); Gaia, R., E-mail: renan-gaia7@hotmail.com [Faculdades Oswaldo Cruz (Brazil)

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  8. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    Science.gov (United States)

    Ferreto, H. F. R.; Oliveira, A. C. F.; Gaia, R.; Parra, D. F.; Lugão, A. B.

    2014-05-01

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of 60Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  9. Gamma-ray-selected AGN

    Science.gov (United States)

    Giommi, Paolo

    2016-08-01

    The gamma-ray band is the most energetic part of the electromagnetic spectrum. As such it is also where selection effects are most severe, as it can only be reached by the most extreme non-thermal AGN. Blazars, with their emission dominated by non-thermal blue-shifted radiation arising in a relativistic jet pointed in the direction of the observer, naturally satisfy this though requirement. For this reason, albeit these sources are intrisically very rare (orders of magnitude less abundant than radio quiet AGN of the same optical magnitude) they almost completely dominate the extragalactic gamma-ray and very high energy sky. I will discuss the emission of different types of blazars and the selection effects that are at play in the gamma-ray band based on recent results from the current generation of gamma-ray astronomy satellites, ground-based Cherenkov telescopes, and Monte Carlo simulations.

  10. Gamma Knife Radiosurgery for Acromegaly

    National Research Council Canada - National Science Library

    Rolston, John D; Blevins, Lewis S

    2012-01-01

    .... Stereotactic radiosurgery, and in particular Gamma Knife surgery (GKS), has proven to be an effective noninvasive adjunct to traditional treatments, leading to disease remission in a substantial proportion of patients...

  11. The GAMMA-400 Space Experiment

    Science.gov (United States)

    Bongi, M.

    2014-06-01

    GAMMA-400 is a new space experiment which will study gamma rays and cosmic rays from about 100 MeV up to some TeVs. The proposed instrument has an angular resolution ˜ 0.1 degrees at 10 GeV and better than ˜ 0.02 degrees above 100 GeV, and an energy resolution ˜ 1% at E > 100 GeV for gamma rays. With these characteristics the experiment will be able to contribute to the search for signatures of Dark Matter, and to the study of Galactic and ex-tragalactic gamma sources and diffuse emission. A large segmented calorimeter more than 25 X0 deep will allow the study of high-energy electrons, and the measurement of the flux of protons and nuclei up to the "knee" region.

  12. Modification Management for Construction Processes

    Institute of Scientific and Technical Information of China (English)

    Wolfgang Huhnt; Sven Richter; Felix Enge

    2008-01-01

    This paper presents an approach to handle different types of subsequent modifications in con-struction processes. It is focused on a formalized approach with the objective that effects of subsequent modifications are detected automatically. The approach presented in this paper makes use of an existing modeling technique specifically focused on construction processes. The modeling techniques result in a process description where all technological interdependencies between construction activities are consid-ered and where consistency between the sequence of activities and the history of components is guaran-teed. This modeling technique is expanded by an existing concept for handling versions and dependencies between objects. The integration of these different concepts makes it possible to track effects of relevant types of subsequent modifications in construction processes on a formalized basis. Effects of subsequent modifications are detected by algorithms, different versions can be compared by algorithms and different versions are stored so that subsequent modifications are documented. The innovation of the approach pre-sented is the completeness. Effects of different relevant types of subsequent modifications in construction processes are tracked on a formalized basis.

  13. Weather Modification: Finding Common Ground.

    Science.gov (United States)

    Garstang, Michael; Bruintjes, Roelof; Serafin, Robert; Orville, Harold; Boe, Bruce; Cotton, William; Warburton, Joseph

    2005-05-01

    Research and operational approaches to weather modification expressed in the National Research Council's 2003 report on “Critical Issues in Weather Modification Research” and in the Weather Modification Association's response to that report form the basis for this discussion. There is agreement that advances in the past few decades over a broad front of understanding physical processes and in technology have not been comprehensively applied to weather modification. Such advances need to be capitalized upon in the form of a concerted and sustained national effort to carry out basic and applied research in weather modification. The need for credible scientific evidence and the pressure for action should be resolved. Differences in the perception of current knowledge, the utility of numerical models, and the specific needs of research and operations in weather modification must be addressed. The increasing demand for water and the cost to society inflicted by severe weather require that the intellectual, technical, and administrative resources of the nation be combined to resolve whether and to what degree humans can influence the weather.The National Center for Atmospheric Research is sponsored by the National Science Foundation

  14. Gamma Astrometric Measurement Experiment

    Science.gov (United States)

    Gai, M.; Lattanzi, M. G.; Ligori, S.; Loreggia, D.; Vecchiato, A.

    GAME aims at the measurement of gravitational deflection of the light by the Sun, by an optimised telescope on board a small class satellite. The targeted precision on the gamma parameter of the Parametrised Post-Newtonian formulation of General Relativity is below 10-6, i.e. one to two orders of magnitude better than the best current results. Such precision is suitable to detect possible deviations from the unity value, associated to generalised Einstein models for gravitation, with potentially huge impacts on the cosmological distribution of dark matter and dark energy. The measurement principle is based on differential astrometry. The observations also allow additional scientific objectives related to tests of General Relativity and to the study of exo-planetary systems. The instrument concept is based on a dual field, multiple aperture Fizeau interferometer, observing simultaneously two regions close to the Solar limb. The diluted optics achieves efficient rejection of the solar radiation, with good angular resolution on the science targets. We describe the science motivation, the proposed mission implementation and the expected performance.

  15. About cosmic gamma ray lines

    Science.gov (United States)

    Diehl, Roland

    2017-06-01

    Gamma ray lines from cosmic sources convey the action of nuclear reactions in cosmic sites and their impacts on astrophysical objects. Gamma rays at characteristic energies result from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. The gamma-ray line from the annihilation of positrons at 511 keV falls into the same energy window, although of different origin. We present here the concepts of cosmic gamma ray spectrometry and the corresponding instruments and missions, followed by a discussion of recent results and the challenges and open issues for the future. Among the lessons learned are the diffuse radioactive afterglow of massive-star nucleosynthesis in 26Al and 60Fe gamma rays, which is now being exploited towards the cycle of matter driven by massive stars and their supernovae; large interstellar cavities and superbubbles have been recognised to be of key importance here. Also, constraints on the complex processes making stars explode as either thermonuclear or core-collapse supernovae are being illuminated by gamma-ray lines, in this case from shortlived radioactivities from 56Ni and 44Ti decays. In particular, the three-dimensionality and asphericities that have recently been recognised as important are enlightened in different ways through such gamma-ray line spectroscopy. Finally, the distribution of positron annihilation gamma ray emission with its puzzling bulge-dominated intensity disctribution is measured through spatially-resolved spectra, which indicate that annihilation conditions may differ in different parts of our Galaxy. But it is now understood that a variety of sources may feed positrons into the interstellar medium, and their characteristics largely get lost during slowing down and propagation of positrons before annihilation; a recent microquasar flare was caught as an opportunity to see positrons annihilate at a source.

  16. Notes on the gamma kernel

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.

    The density function of the gamma distribution is used as shift kernel in Brownian semistationary processes modelling the timewise behaviour of the velocity in turbulent regimes. This report presents exact and asymptotic properties of the second order structure function under such a model......, and relates these to results of von Karmann and Horwath. But first it is shown that the gamma kernel is interpretable as a Green’s function....

  17. Dark Matter Search Perspectives with GAMMA-400

    CERN Document Server

    Moiseev, A A; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Avanesov, G A; Bergstrom, L; Boezio, M; Bonvicini, V; Boyarchuk, K A; Dogiel, V A; Gusakov, Yu V; Fradkin, M I; Fuglesang, Ch; Hnatyk, B I; Kachanov, V A; Kaplin, V A; Kheymits, M D; Korepanov, V; Larsson, J; Leonov, A A; Longo, F; Maestro, P; Marrocchesi, P; Mazets, E P; Mikhailov, V V; Mocchiutti, E; Mori, N; Moskalenko, I; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Runtso, M F; Ryde, F; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Topchiev, N P; Vacchi, A; Vannuccini, E; Yurkin, Yu T; Zampa, N; Zarikashvili, V N; Zverev, V G

    2013-01-01

    GAMMA-400 is a future high-energy gamma-ray telescope, designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of dark matter particles, and to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to ~3000 GeV. Its angular resolution is ~0.01 deg(Eg > 100 GeV), and the energy resolution ~1% (Eg > 10 GeV). GAMMA-400 is planned to be launched on the Russian space platform Navigator in 2019. The GAMMA-400 perspectives in the search for dark matter in various scenarios are presented in this paper

  18. Stress Assessment by Prefrontal Relative Gamma

    Science.gov (United States)

    Minguillon, Jesus; Lopez-Gordo, Miguel A.; Pelayo, Francisco

    2016-01-01

    Stress assessment has been under study in the last years. Both biochemical and physiological markers have been used to measure stress level. In neuroscience, several studies have related modification of stress level to brain activity changes in limbic system and frontal regions, by using non-invasive techniques such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). In particular, previous studies suggested that the exhibition or inhibition of certain brain rhythms in frontal cortical areas indicates stress. However, there is no established marker to measure stress level by EEG. In this work, we aimed to prove the usefulness of the prefrontal relative gamma power (RG) for stress assessment. We conducted a study based on stress and relaxation periods. Six healthy subjects performed the Montreal Imaging Stress Task (MIST) followed by a stay within a relaxation room while EEG and electrocardiographic signals were recorded. Our results showed that the prefrontal RG correlated with the expected stress level and with the heart rate (HR; 0.8). In addition, the difference in prefrontal RG between time periods of different stress level was statistically significant (p < 0.01). Moreover, the RG was more discriminative between stress levels than alpha asymmetry, theta, alpha, beta, and gamma power in prefrontal cortex. We propose the prefrontal RG as a marker for stress assessment. Compared with other established markers such as the HR or the cortisol, it has higher temporal resolution. Additionally, it needs few electrodes located at non-hairy head positions, thus facilitating the use of non-invasive dry wearable real-time devices for ubiquitous assessment of stress. PMID:27713698

  19. Gamma-ray Pulsar Revolution

    CERN Document Server

    Caraveo, Patrizia A

    2013-01-01

    Isolated Neutron Stars (INSs) were the first sources identified in the field of high-energy gamma-ray astronomy. At first, in the 70s, there were only two identified sources, the Crab and Vela pulsars. However, although few in number, these objects were crucial in establishing the very concept of a gamma-ray source. Moreover, they opened up significant discovery space both in the theoretical and phenomenological fronts. The need to explain the copious gamma-ray emission of these pulsars led to breakthrough developments in understanding the structure and physics of neutron star magnetospheres. In parallel, the 20-year-long chase to understand the nature of Geminga unveiled the existence of a radio-quiet, gamma-ray-emitting, INS, adding a new dimension to the INS family. Today we are living through an extraordinary time of discovery. The current generation of gamma-ray detectors has vastly increased the population of known of gamma-ray-emitting neutron stars. The 100 mark was crossed in 2011 and we are now appr...

  20. Observation of B_s to phi gamma and Search for B_s to gamma gamma Decays at Belle

    CERN Document Server

    Wicht, J; Aihara, H; Arinstein, K; Aulchenko, V; Aushev, T; Bakich, A M; Balagura, V; Bay, A; Belous, K S; Bhardwaj, V; Bitenc, U; Bondar, A; Bozek, A; Brako, M; Browder, T E; Chang, cP; Chao, Y; Chen, A; Chen, K F; Chen, W T; Cheon, B G; Chistov, R; Cho, I S; Choi, Y; Dalseno, J; Dash, M; Drutskoy, A; Eidelman, S; Gabyshev, N; Goldenzweig, P; Golob, B; Haba, J; Hayasaka, K; Hazumi, M; Heffernan, D; Hoshi, Y; Hou, W S; Hsiung, Y B; Hyun, H J; Iijima, T; Inami, K; Ishikawa, A; Ishino, H; Itoh, R; Iwasaki, Y; Kah, D H; Kaji, H; Kang, J H; Kapusta, P; Kawai, H; Kawasaki, T; Kichimi, H; Kim, H J; Kim, H O; Kim, S K; Kim, Y J; Kinoshita, K; Korpar, S; Krian, P; Kumar, R; Kuo, C C; Kwon, Y J; Lange, J S; Lee, J; Lee, z J S; Lee, S E; Lesiak, T; Limosani, A; Lin, S W; Liu, Y; Liventsev, D; Mandl, F; McOnie, S; Medvedeva, T; Mitaroff, W A; Miyabayashi, K; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Mohapatra, D; Moloney, G R; Nakao, M; Natkaniec, Z; Nishida, S; Nitoh, O; Nozaki, T; Ogawa, S; Ohshima, T; Okuno, S; Ozaki, H; Pakhlov, P; Pakhlova, G; Palka, H; Park, C W; Park, H; Park, K S; Pestotnik, R; Piilonen, L E; Sakai, Y; Schneider, O; Schümann, J; Schwartz, A J; Senyo, K; Sevior, M E; Shapkin, M; Shibuya, H; Shiu, J G; Shwartz, B; Singh, J B; Somov, A; Stani, S; Stari, M; Sumisawa, K; Sumiyoshi, T; Takasaki, F; Tamai, K; Tanaka, M; Taylor, G N; Teramoto, Y; Trabelsi, cK; Tsuboyama, T; Uehara, S; Ueno, K; Unno, Y; Uno, S; Ushiroda, Y; Usov, Yu; Varner, G; Vervink, K; Villa, S; Wang, C H; Wang, P; Wang, X L; Watanabe, Y; Won, E; Yabsley, B D; Yamashita, Y; Yamauchi, M; Yusa, Y; Zhang, Z P; Zhilich, V; Zupanc, A; Zwahlen, N

    2007-01-01

    We search for the radiative penguin decays B_s to phi gamma and B_s to gamma gamma in a 23.6 fb-1 data sample collected at the Upsilon(5S) resonance with the Belle detector at the KEKB e+e- asymmetric-energy collider. We observe for the first time a radiative penguin decay of the B_s meson in the B_s to phi gamma mode. No significant B_s to gamma gamma signal is observed.

  1. Search for the Radiative Penguin Decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Allmendinger, T; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2004-01-01

    A search for the decays B --> rho(770) gamma and B0 --> omega(782)gamma is performed on a sample of 211 million Y(4S)->BBbar events collected by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions BF(B --> rho+ gamma) rho0 gamma) omega gamma) (rho/omega) gamma]<1.2 x 10^-6 and constrain V_td/V_ts< 0.19 at the 90% C.L.

  2. The Gamma-ray Sky with Fermi

    Science.gov (United States)

    Thompson, David

    2012-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  3. Laser modification of polyamide fabrics

    Science.gov (United States)

    Bahtiyari, M. İ.

    2011-02-01

    A new method for the modification of the properties of polyamide fabric, based on exposure to the output from a CO 2 laser, has been investigated. It was found that, after laser modification of polyamide fabric, the dyeability of fabric was increased significantly, while the bursting strength was decreased. The reasons for this drastic increase in dyeability of polyamide fabrics have been analyzed with the help of FTIR and iodine sorption methods, revealing a relationship with a decrease in the crystallinity of the polyamide. It was observed that, as the laser modification of the fabric was carried out with low intensity, the concentration of free amino groups, which are necessary during dyeing with acid and reactive dyes, increased.

  4. Functionalised Polymers by Surface Modification

    Institute of Scientific and Technical Information of China (English)

    Jon-Paul Griffiths; M. G. Moloney

    2005-01-01

    @@ 1Introduction Surface-active polymers are of substantial importance in many diverse aspects of modern technology, with applications ranging from solid phase chemical synthesis related to drug discovery and chemical catalysis to biocompatible/bioactive medical implants and prostheses, and to surface-modified fabrics. Whilst there are a number of existing physical (e. g. corona or plasma discharge, ion beam irradiation[1] ) and chemical (e. g.silanisation, oxidation, chlorination, acylation and quaternisation[2-4]) methods for the surface modification of polymers, the frequent requirement for significant infrastructure, harsh reaction conditions, and limitation to specific polymer types (e. g. polybutadiene[5] ), which must possess suitable chemical functionality capable of direct modification, led us to consider alternative chemical methods. Desirable was an alternative that would be amenable to a large range of polymers, permitting direct chemical modification under mild conditions and using inexpensive reagents.

  5. Surface modification for corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1993-06-01

    The raw gas environments that arise from coal gasification have chemical compositions that are low in pO{sub 2} and moderate-to-high in pS{sub 2}. Metallic materials for service in such an environment undergo predominantly sulfidation attack at temperatures of 400 to 700{degree}C. Modification of alloy compositions in bulk can alter the scaling processes and lead to improvements in corrosion resistance, but the benefits can only be attained at temperatures much higher than the service temperatures of the components. Modification of surfaces of structural components by several of the coating techniques examined in this study showed substantial benefit in corrosion resistance when tested in simulated coal gasification environments. The paper presents several examples of surface modification and their corrosion performance.

  6. Measurement of the Branching Ratios Gamma(D_s*+ -> D_s+ pi0)/Gamma(D_s*+ -> D_s+ gamma) and Gamma(D0+ -> D0 pi0)/Gamma(D0* -> D0 gamma)

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Minamora, J S; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Altenburg, D; Feltresi, E; Hauke, A; Spaan, B; Brandt, T; Brose, J; Dickopp, M; Klose, V; Lacker, H M; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Wu, J; Dubitzky, R S; Langenegger, U; Marks, J; Schenk, S; Uwer, U; Schott, G; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Chai, X; Charles, M J; Mader, W F; Mallik, U; Mohapatra, A K; Ziegler, V; Cochran, J; Crawley, H B; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Petersen, T C; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Schofield, K C; Touramanis, C; Cormack, C M; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flächer, H U; Green, M G; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Edgar, C L; Hodgkinson, M C; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Li, X; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côte, D; Taras, P; Viaud, B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pacetti, S; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Wilson, F F; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Graziani, G; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Martínez-Vidal, F; Panvini, R S; Banerjee, S; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Tan, P; Wu, S L; Yu, Z; Neal, H

    2005-01-01

    Data samples corresponding to the isospin-violating decay $D_s^{*+}\\to D_s^+ \\pi^0$ and the decays $D_s^{*+}\\to D_s^+\\gamma$, $D^{*0}\\to D^0\\pi^0$ and $D^{*0}\\to D^0\\gamma$ are reconstructed using 90.4 ${\\rm fb}^{-1}$ of data recorded by the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ collider. The following branching ratios are extracted: $\\Gamma(D_s^{*+}\\to D_s^+ \\pi^0)/\\Gamma(D_s^{*+}\\to D_s^+\\gamma) = 0.062\\pm0.005 ({\\rm stat.})\\pm0.006 ({\\rm syst.})$ and $\\Gamma(D^{*0}\\to D^0\\pi^0)/\\Gamma(D^{*0}\\to D^0\\gamma) = 1.74\\pm0.02 ({\\rm stat.})\\pm0.13 ({\\rm syst.})$. Both measurements represent significant improvements over present world averages.

  7. In-medium modifications of the $\\pi\\pi$ interaction in photon-induced reactions

    CERN Document Server

    Messchendorp, J G; Kotulla, M; Ahrens, J; Annand, J R M; Beck, R; Bloch, Felix; Caselotti, G; Fog, L; Hornidge, D; Krusche, B; Langgärtner, W; McGeorge, J C; MacGregor, I J D; Mengel, K; Metag, V; Novotny, R; Owens, R O; Pfeiffer, M; Sack, S; Sanderson, R; Schadmand, S

    2002-01-01

    Differential cross sections of the reactions $(\\gamma,\\pi^\\circ\\pi^\\circ)$ and $(\\gamma,\\pi^\\circ\\pi^++\\pi^\\circ\\pi^-)$ have been measured for several nuclei ($^1$H,$^{12}$C, and $^{\\rm nat}$Pb) at an incident-photon energy of $E_{\\gamma}$=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the $\\pi\\pi$ invariant-mass distribution is found in the $\\pi^\\circ\\pi^\\circ$ channel. This dependence is not observed in the $\\pi^\\circ\\pi^{+/-}$ channel and is consistent with an in-medium modification of the $\\pi\\pi$ interaction in the $I$=$J$=0 channel. The data are compared to $\\pi$-induced measurements and to calculations within a chiral-unitary approach.

  8. In-medium modifications of the pipi interaction in photon-induced reactions.

    Science.gov (United States)

    Messchendorp, J G; Janssen, S; Kotulla, M; Ahrens, J; Annand, J R H; Beck, R; Bloch, F; Caselotti, G; Fog, L; Hornidge, D; Krusche, B; Langgärtner, W; McGeorge, J C; MacGregor, I J D; Mengel, K; Metag, V; Novotny, R; Owens, R O; Pfeiffer, M; Sack, S; Sanderson, R; Schadmand, S

    2002-11-25

    Differential cross sections of the reactions (gamma,pi(0)pi(0)) and (gamma,pi(0)pi(+/-)) have been measured for several nuclei (1H,12C, and (nat)Pb) at an incident-photon energy of E(gamma)=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the pipi invariant-mass distribution is found in the pi(0)pi(0) channel. This dependence is not observed in the pi(0)pi(+/-) channel and is consistent with an in-medium modification of the pipi interaction in the I=J=0 channel. The data are compared to pi-induced measurements and to calculations within a chiral-unitary approach.

  9. Extragalactic Gamma-Ray Astrophysics

    CERN Document Server

    CERN. Geneva

    2016-01-01

    During the last decades, various classes of radio-loud active galactic nuclei have been established as sources of high-energy radiation extending over a very broad range from soft gamma-rays (photon energies E~MeV) up to very-high-energy gamma-rays (E>100 GeV). These include blazars of different types, as well as young and evolved radio galaxies. The observed gamma-ray emission from such implies efficient particle acceleration processes taking place in highly magnetized and relativistic jets produced by supermassive black holes, processes that have yet to be identified and properly understood. In addition, nearby starforming and starburst galaxies, some of which host radio-quiet Seyfert-type nuclei, have been detected in the gamma-ray range as well. In their cases, the observed gamma-ray emission is due to non-thermal activity in the interstellar medium, possibly including also a contribution from accretion disks and nuclear outflows. Finally, the high-energy emission from clusters of galaxies remains elusive...

  10. AGATA - Advanced GAmma Tracking Array

    Energy Technology Data Exchange (ETDEWEB)

    Akkoyun, S. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Algora, A. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); Alikhani, B. [IKP, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Ameil, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Angelis, G. de [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Arnold, L. [Universite de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg (France); CNRS, UMR 7178, 67037 Strasbourg (France); Astier, A. [CSNSM, CNRS, IN2P3, Universite Paris-Sud, F-91405 Orsay (France); Atac, A. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Royal Institute of Technology, SE-10691 Stockholm (Sweden); Aubert, Y. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Aufranc, C. [Universite de Lyon, Universite Lyon 1, CNRS-IN2P3, Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne (France); Austin, A. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Aydin, S. [INFN Sezione di Padova, IT-35131 Padova (Italy); Azaiez, F. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Badoer, S. [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Balabanski, D.L. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Barrientos, D. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); and others

    2012-03-11

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation {gamma}-ray spectrometer. AGATA is based on the technique of {gamma}-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a {gamma} ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of {gamma}-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  11. FEL system for gamma-gamma collider at TESLA

    CERN Document Server

    Saldin, E L; Yurkov, M V

    2001-01-01

    The present paper contains the results of optimization of the free electron laser for the gamma-gamma collider at TESLA. A superconducting linear accelerator, similar to the TTF (TESLA Test Facility) accelerator, produces a driving electron beam for the FEL. The MOPA FEL scheme is studied when the radiation from a master oscillator is amplified in the FEL amplifier with tapered undulator. The FEL produces a radiation of TW level with a wavelength of 1 mu m. Optimization of the FEL amplifier is performed with a three-dimensional, time-dependent simulation code FAST.

  12. Free electron laser for gamma-gamma collider at TESLA

    CERN Document Server

    Saldin, E L; Yurkov, M V

    2000-01-01

    The present paper contains the results of optimization of the free electron laser for the gamma-gamma collider at TESLA. A superconducting linear accelerator, similar to the TESLA test facility (TTF) accelerator, produces a driving electron beam for the FEL. The MOPA FEL scheme is studied when the radiation from a master oscillator is amplified in the FEL amplifier with tapered undulator. The FEL produces the radiation of TW level with a wavelength of 1 mu m. Optimization of the FEL amplifier is performed with three-dimensional, time-dependent simulation code FAST.

  13. Mirror matter admixtures in K_S to gamma gamma

    CERN Document Server

    Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto

    2006-01-01

    The latest measurement of the K_S to gamma gamma branching ratio clearly shows an enhancement over the current theoretical prediction. As in other K and B meson decays, this invites to consider the possibility of the contribution of new physics. We study a particular form of the latter, which may be referred to as manifest mirror symmetry. The experimental data are described using previously determined values for the mixing angles of the admixtures of mirror matter in ordinary hadrons and by assuming that for pi^0, eta, eta', the mirror decay amplitudes have the same magnitudes as their ordinary counterparts.

  14. Signals for Majorana neutrinos in a $\\gamma \\gamma$ collider

    CERN Document Server

    Peressutti, G

    2003-01-01

    We study the possibilities to detect Majorana neutrinos in $\\gamma \\gamma$ colliders for different center of mass energies. We study the $W^\\pm W^\\pm l_j^{\\mp} l_k^{\\mp}$ ($l_j\\equiv e ,\\mu ,\\tau$) final states which are, due to leptonic number violation, a clear signature for intermediate Majorana neutrino contribution. Such a signal (final dileptons of the same sign) is not possible if the heavy neutrinos are Dirac particles. We present our results for the total cross-section as a function of the neutrino mass and the center of mass energies.

  15. Revisiting \\gamma\\gamma->\\pi^+\\pi^- at low energies

    CERN Document Server

    Gasser, J; Sainio, M E; Gasser, Juerg; Ivanov, Mikhail A.; Sainio, Mikko E.

    2006-01-01

    We complete the recalculation of the available two-loop expressions for the reaction \\gamma\\gamma->\\pi\\pi in the framework of chiral perturbation theory. Here, we present the results for charged pions. The cross section and the values of the dipole polarizabilities agree very well with the earlier calculation, provided the same set of low-energy constants (LECs) is used. With updated values for the LECs at order p^4, we find for the dipole polarizabilities (\\alpha_1-\\beta_1)_{\\pi^\\pm} = (5.7\\pm 1.0) 10^{-4} fm^3, which is in conflict with the experimental result recently reported by the MAMI Collaboration.

  16. Modification on epoxy-based adhesive

    Institute of Scientific and Technical Information of China (English)

    ZhengXiaoxia; QianChunxiang

    2003-01-01

    This research adopted four methods to toughen epoxy adhesives. They were liquid hydroxyl group terminated polybutadiene (HTPB) rubber modification, silicon rubber modification, polyacrylate multiplicity elastomer particulates emulsion modification and chemical grafting modification. After modification, the shearing strength and the rapture elongation were tested. The interface and the chemical reaction between the modifiers and the epoxy were analyzed by scanning electron microscope (SEM) and infrared optical spectrum. The results show that the elastomer particulates modification and the chemical grafting modification can reach the better toughening effects.

  17. [Targeted genome modifications using TALEN].

    Science.gov (United States)

    Dupret, Barbara; Angrand, Pierre-Olivier

    2014-02-01

    Precise modifications of genomes have been one of the biggest goals in the fields of biotechnology and biomedical research. Recent discovery of TALE (transcription activator-like effectors) and the engineering of customized TALEN (transcription activator-like effector nucleases) allowed rapid genome editing in a variety of cell types and different model organisms. TALEN are molecular scissors used to induce a wide range of specific and efficient genomic modifications. TALEN promise to have profound impacts on biological and medical research over the coming years.

  18. Structural dynamic modifications via models

    Indian Academy of Sciences (India)

    T K Kundra

    2000-06-01

    Structural dynamic modification techniques attempt to reduce dynamic design time and can be implemented beginning with spatial models of structures, dynamic test data or updated models. The models assumed in this discussion are mathematical models, namely mass, stiffness, and damping matrices of the equations of motion of a structure. These models are identified/extracted from dynamic test data viz. frequency response functions (FRFs). Alternatively these models could have been obtained by adjusting or updating the finite element model of the structure in the light of the test data. The methods of structural modification for getting desired dynamic characteristics by using modifiers namely mass, beams and tuned absorbers are discussed.

  19. Mechanical performance of gamma irradiated surgical sutures

    Energy Technology Data Exchange (ETDEWEB)

    Pino, Eddy S.; Rela, Paulo P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2000-07-01

    Surgical sutures are medical devices made of natural or synthetic polymeric materials that, due to its end-use, have to be sterilized. Historically, the sterilization by heat or using ethylene oxide had presented so numerous drawbacks that today the non-pollutant radiation sterilization has become a well established sterilization process, that brings, environmental, technical, and economical advantages. The amount of irradiation doses required for sterilization of health care products is 25 kGy in most instances to achieve the necessary sterility assurance level. As high energy radiation produces modifications in the molecular structure of organic materials with changes in its mechanical properties, the aim of this work was to evaluate the mechanical behavior of surgical sutures under irradiation. Silk, polyamide and catgut sutures were gamma irradiated up to doses of 50 kGy in an industrial irradiation sterilization plant. Afterwards, these sutures were mechanical tested for tensile strength under knot following the specifications of the NBR13904 draft standard, using the CTRD-INSTRON at IPEN. The mechanical lab results show that sutures made of Silk and Polyamide do not present any change in their mechanical performance up to the dose of 50 kGy. On the other hand, Catgut present mechanical stability up to 30 kGy and afterwards, a slight decrease in its tensile strength was detected. (author)

  20. Depth of interaction detection for {gamma}-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain)], E-mail: lerche@ific.uv.es; Doering, M. [Institut fuer Kernphysik, Forschungszentrum Juelich GmbH, D52425 Juelich (Germany); Ros, A. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain); Herrero, V.; Gadea, R.; Aliaga, R.J.; Colom, R.; Mateo, F.; Monzo, J.M.; Ferrando, N.; Toledo, J.F.; Martinez, J.D.; Sebastia, A. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain); Sanchez, F.; Benlloch, J.M. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain)

    2009-03-11

    A novel design for an inexpensive depth of interaction capable detector for {gamma}-ray imaging has been developed. The design takes advantage of the strong correlation between the width of the scintillation light distribution in monolithic crystals and the interaction depth of {gamma}-rays. We present in this work an inexpensive modification of the commonly used charge dividing circuits which enables the instantaneous and simultaneous computation of the second order moment of light distribution. This measure provides a good estimate for the depth of interaction and does not affect the determination of the position centroids and the energy release of {gamma}-ray impact. The method has been tested with a detector consisting of a monolithic LSO block sized 42x42x10mm{sup 3} and a position-sensitive photomultiplier tube H8500 from Hamamatsu. The mean spatial resolution of the detector was found to be 3.4mm for the position centroids and 4.9mm for the DOI. The best spatial resolutions were observed at the center of the detector and yielded 1.4mm for the position centroids and 1.9mm for the DOI.

  1. Terrestrial gamma-ray flashes

    Energy Technology Data Exchange (ETDEWEB)

    Marisaldi, Martino, E-mail: marisaldi@iasfbo.inaf.it [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Fuschino, Fabio; Labanti, Claudio [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Tavani, Marco [INAF-IASF Roma, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Argan, Andrea [INAF, Viale del Parco Mellini 84, 00136 Roma (Italy); Del Monte, Ettore [INAF-IASF Roma, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Longo, Francesco; Barbiellini, Guido [Dipartimento di Fisica Università di Trieste and INFN Trieste, via A. Valerio 2, I-34127 Trieste (Italy); Giuliani, Andrea [INAF-IASF Milano, Via Bassini 15, I-20133 Milano (Italy); Trois, Alessio [INAF Osservatorio Astronomico di Cagliari, loc. Poggio dei Pini, strada 54, I-09012 Capoterra (Italy); Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy)

    2013-08-21

    Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.

  2. Zeptosecond $\\gamma$-ray pulses

    CERN Document Server

    Klaiber, Michael; Keitel, Christoph H

    2007-01-01

    High-order harmonic generation (HHG) in the relativistic regime is employed to obtain zeptosecond pulses of $\\gamma$-rays. The harmonics are generated from atomic systems in counterpropagating strong attosecond laser pulse trains of linear polarization. In this setup recollisions of the ionized electrons can be achieved in the highly relativistic regime via a reversal of the commonly deteriorating drift and without instability of the electron dynamics such as in a standing laser wave. As a result, coherent attosecond $\\gamma$-rays in the 10 MeV energy range as well as coherent zeptosecond $\\gamma$-ray pulses of MeV photon energy for time-resolved nuclear spectroscopy become feasible.

  3. Design and Performance of the GAMMA-400 Gamma-Ray Telescope for the Dark Matter Searches

    CERN Document Server

    Galper, A M; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Boezio, M; Bonvicini, V; Boyarchuk, K A; Fradkin, M I; Gusakov, Yu V; Kaplin, V A; Kachanov, V A; Kheymits, M D; Leonov, A A; Longo, F; Mazets, E P; Maestro, P; Marrocchesi, P; Mereminskiy, I A; Mikhailov, V V; Moiseev, A A; Mocchiutti, E; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Picozza, P; Rodin, V G; Runtso, M F; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Topchiev, N P; Vacchi, A; Vannuccini, E; Yurkin, Yu T; Zampa, N; Zverev, V G; Zirakashvili, V N

    2012-01-01

    The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. The GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ~0.01 deg (E{\\gamma} > 100 GeV), the energy resolution ~1% (E{\\gamma} > 10 GeV), and the proton rejection factor ~10E6. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

  4. Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

    Science.gov (United States)

    Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu

    2012-01-01

    The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons (+) positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is approximately 0.01deg (E(sub gamma) greater than 100 GeV), the energy resolution approximately 1% (E(sub gamma) greater than 10 GeV), and the proton rejection factor approximately 10(exp 6). GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

  5. Characterization and improvement of water compatibility of {gamma}-LiAlO{sub 2} ceramic breeders

    Energy Technology Data Exchange (ETDEWEB)

    Lin Jiu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 DingXi Road, Shanghai 200050 (China); Wen Zhaoyin, E-mail: zywen@mail.sic.ac.cn [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 DingXi Road, Shanghai 200050 (China); Xu Xiaogang; Li Ning; Song Shufeng [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 DingXi Road, Shanghai 200050 (China)

    2010-12-15

    The influence of water treatment at 473 K on the phase and morphology of the {gamma}-LiAlO{sub 2} ceramics was studied. It was implied that a AlO(OH) layer was formed on the surface of the {gamma}-LiAlO{sub 2} ceramics, at the same time LiAl{sub 2}(OH){sub 7}.xH{sub 2}O was obtained in the water. The process of the interaction between {gamma}-LiAlO{sub 2} ceramics and water was deduced. The attempts to improve the water compatibility of {gamma}-LiAlO{sub 2} ceramics were made. It was confirmed that the surface modification by LiAl{sub 5}O{sub 8} decreased the surface alkalinity and restrained the hydrolysis of the {gamma}-LiAlO{sub 2} ceramics in water due to the low hydrolysis of the lithium deficient phase LiAl{sub 5}O{sub 8}. The experimental results revealed that the introduction of the lithium deficient phase, LiAl{sub 5}O{sub 8}, effectively improved the water compatibility of the {gamma}-LiAlO{sub 2} ceramics.

  6. Peroxisomal beta-oxidation activities and gamma-decalactone production by the yeast Yarrowia lipolytica.

    Science.gov (United States)

    Pagot, Y; Le Clainche, A; Nicaud, J M; Wache, Y; Belin, J M

    1998-03-01

    gamma-Decalactone is a peachy aroma compound resulting from the peroxisomal beta-oxidation of ricinoleic acid by yeasts. The expression levels of acyl-CoA oxidase (gene deletion) and 3-ketoacyl-CoA thiolase activities (gene amplification on replicative plasmids) were modified in the yeast Yarrowia lipolytica. The effects of these modifications on beta-oxidation were measured. Overexpression of thiolase activity did not have any effect on the overall beta-oxidation activity. The disruption of one of the acyl-CoA oxidase genes resulted in an enhanced activity. The enhancement led to an increase of overall beta-oxidation activity but reduced the gamma-decalactone production rates. This seemed to indicate a non-rate-limiting role for beta-oxidation in the biotransformation of ricinoleic acid to gamma-decalactone by the yeast Yarrowia lipolytica. All strains produced and then consumed gamma-decalactone. We checked the ability of the different strains to consume gamma-decalactone in a medium containing the lactone as sole carbon source. The consumption of the strain overexpressing acyl-CoA oxidase activity was higher than that of the wild-type strain. We concluded that peroxisomal beta-oxidation is certainly involved in gamma-decalactone catabolism by the yeast Y. lipolytica. The observed production rates probably depend on an equilibrium between production and consumption of the lactone.

  7. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  8. Gamma-ray burst spectra

    Science.gov (United States)

    Teegarden, B. J.

    1982-01-01

    A review of recent results in gamma-ray burst spectroscopy is given. Particular attention is paid to the recent discovery of emission and absorption features in the burst spectra. These lines represent the strongest evidence to date that gamma-ray bursts originate on or near neutron stars. Line parameters give information on the temperature, magnetic field and possibly the gravitational potential of the neutron star. The behavior of the continuum spectrum is also discussed. A remarkably good fit to nearly all bursts is obtained with a thermal-bremsstrahlung-like continuum. Significant evolution is observed of both the continuum and line features within most events.

  9. Plasma surface modification of polymers

    Science.gov (United States)

    Hirotsu, T.

    1980-01-01

    Thin plasma polymerization films are discussed from the viewpoint of simplicity in production stages. The application of selective, absorbent films and films used in selective permeability was tested. The types of surface modification of polymers discussed are: (1) plasma etching, (2) surface coating by plasma polymerized thin films, and (3) plasma activation surface graft polymerization.

  10. Electrostatic modification of novel materials

    NARCIS (Netherlands)

    Ahn, C.H.; Bhattacharya, A.; Di Ventra, M.; Eckstein, J.N.; Frisbie, C.D.; Gershenson, M.E.; Goldman, A.M.; Inoue, I.H.; Mannhart, J.; Millis, A.J.; Morpurgo, A.F.; Natelson, D.; Triscone, J.M.

    2006-01-01

    Application of the field-effect transistor principle to novel materials to achieve electrostatic doping is a relatively new research area. It may provide the opportunity to bring about modifications of the electronic and magnetic properties of materials through controlled and reversible changes of t

  11. Behavior Modification in Marriage Counseling

    Science.gov (United States)

    Baird, Emily; Redfering, David L.

    1975-01-01

    The spouses were counseled jointly with a cognitive approach and separately with behavior modification techniques for the husband's obesity and the wife's lack of affective verbalization. After eight weeks, the husband had lost thirty pounds and the wife's affective language had increased markedly. (Author)

  12. A NEW "PROCESSABLE" POLYACETYLENE MODIFICATION

    OpenAIRE

    Hocker, J.; Schneider, G.

    1983-01-01

    Using a special catalyst on the Ziegler-Natta basis and special reaction conditions it is possible to polymerize acetylene for obtaining a new polyacetylene modification with burr- or fibre-shaped particles which can be processed to foils, non-wovens and coatings.

  13. Supervisory Workbook on Behavior Modification.

    Science.gov (United States)

    Arkin, Ronald; And Others

    This workbook is designed to be used with the trainer's manual in supervisory training sessions on behavior modification of employees. This is one of four manuals prepared to aid supervisors in training disadvantaged groups using social reinforcement techniques. Related documents are available as VT 018 031-VT 018 035 in this issue. (MF)

  14. Synthesis and Modification of Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Pavlina Ambrozova

    2017-07-01

    Full Text Available Clinoptilolite is a natural mineral with exceptional physical characteristics resulting from its special crystal structure, mainstreamed into a large zeolite group called heulandites. An overall view of the research related to the synthesis, modification and application of synthetic clinoptilolite is presented. A single phase of clinoptilolite can be hydrothermally synthesized for 1–10 days in an autoclave from various silica, alumina, and alkali sources with initial Si/Al ratio from 3.0 to 5.0 at a temperature range from 120 to 195 °C. Crystallization rate and crystallinity of clinoptilolite can be improved by seeding. The modification of clinoptilolite has received noticeable attention from the research community, since modified forms have specific properties and therefore their area of application has been broadening. This paper provides a review of the use of organic compounds such as quarter alkyl ammonium, polymer, amine and inorganic species used in the modification process, discusses the processes and mechanisms of clinoptilolite modification, and identifies research gaps and new perspectives.

  15. Synthesis and Modification of Clinoptilolite.

    Science.gov (United States)

    Ambrozova, Pavlina; Kynicky, Jindrich; Urubek, Tomas; Nguyen, Vinh Dinh

    2017-07-04

    Clinoptilolite is a natural mineral with exceptional physical characteristics resulting from its special crystal structure, mainstreamed into a large zeolite group called heulandites. An overall view of the research related to the synthesis, modification and application of synthetic clinoptilolite is presented. A single phase of clinoptilolite can be hydrothermally synthesized for 1-10 days in an autoclave from various silica, alumina, and alkali sources with initial Si/Al ratio from 3.0 to 5.0 at a temperature range from 120 to 195 °C. Crystallization rate and crystallinity of clinoptilolite can be improved by seeding. The modification of clinoptilolite has received noticeable attention from the research community, since modified forms have specific properties and therefore their area of application has been broadening. This paper provides a review of the use of organic compounds such as quarter alkyl ammonium, polymer, amine and inorganic species used in the modification process, discusses the processes and mechanisms of clinoptilolite modification, and identifies research gaps and new perspectives.

  16. Production of high-energy colliding. gamma gamma. and. gamma. e beams with a high luminosity at VLEPP accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Tel' nov, V.I.

    1981-11-05

    Colliding ..gamma gamma.. and ..gamma..e beams with an energy and luminosity of the same order of magnitude as for e/sup +/e/sup -/ beams can be produced by scattering a laser light at the accelerators with colliding e/sup +/e/sup -/ beams with an energy > or approx. =100 GeV. Such accelerators are currently in the design stage.

  17. Pion Polarizabilities from $\\gamma\\gamma\\to\\pi\\pi$ Analysis

    CERN Document Server

    Dai, Ling-Yun

    2016-01-01

    We present results for pion polarizabilities predicted using dispersion relations from our earlier Amplitude Analysis of world data on two photon production of meson pairs. The helicity-zero polarizabilities are rather stable and insensitive to uncertainties in cross-channel exchanges. The need is first to confirm the recent result on $(\\alpha_1-\\beta_1)$ for the charged pion by COMPASS at CERN to an accuracy of 10\\% by measuring the $\\gamma\\gamma\\to\\pi^+\\pi^-$ cross-section to an uncertainty of ~1\\%. Then the same polarizability, but for the $\\pi^0$, is fixed to be $(\\alpha_1-\\beta_1)_{\\pi^0}=(0.9\\pm0.2)\\times 10^{-4}$ fm$^{3}$. By analyzing the correlation between uncertainties in the meson polarizability and those in $\\gamma\\gamma$ cross-sections, we suggest experiments need to measure these cross-sections between $\\sqrt{s}\\simeq 350$ and 600~MeV. The $\\pi^0\\pi^0$ cross-section then makes the $(\\alpha_2-\\beta_2)_{\\pi^0}$ the easiest helicity-two polarizability to determine.

  18. QCD and $\\gamma\\,\\gamma$ studies at FCC-ee

    CERN Document Server

    Skands, Peter

    2016-01-01

    The Future Circular Collider (FCC) is a post-LHC project aiming at searches for physics beyond the SM in a new 80--100~km tunnel at CERN. Running in its first phase as a very-high-luminosity electron-positron collider (FCC-ee), it will provide unique possibilities for indirect searches of new phenomena through high-precision tests of the SM. In addition, by collecting tens of ab$^{-1}$ integrated luminosity in the range of center-of-mass energies $\\sqrt{s}$~=90--350~GeV, the FCC-ee also offers unique physics opportunities for precise measurements of QCD phenomena and of photon-photon collisions through, literally, billions of hadronic final states as well as unprecedented large fluxes of quasireal $\\gamma$'s radiated from the $\\rm e^+e^-$ beams. We succinctly summarize the FCC-ee perspectives for high-precision extractions of the QCD coupling, for detailed analyses of parton radiation and fragmentation, and for SM and BSM studies through $\\gamma\\gamma$ collisions.

  19. A {beta} - {gamma} coincidence; Metodo de coincidencias {beta} - {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Agullo, F.

    1960-07-01

    A {beta} - {gamma} coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from {sup 1}98 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs.

  20. gamma. radiolysis of polyethylene grafted with sytrene. [Gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, H.; Shimizu, Y.

    1981-06-01

    ..gamma.. radiolysis of polyethylene grafted with styrene of 0-76 wt % was carried out at 30-100/sup 0/C in vacuo with a dose rate of 6.35 x 10/sup 5/ rad/hr. The formation of hydrogen and trans-vinylene unsaturation decreased as the content of styrene unit in polymer increased and the rate of formulation was described by zero-order formation kinetics with respect to each concentration combined with first-order disappearance. The gel fraction changed with the content of styrene unit according to irradation time and temperature. The gel data were evaluated by using the Charlesby-Pinner equation. Kinetic analysis showed that in ..gamma.. radiolysis of polyethylene grafted with styrene the formation of hydrogen is somewhat retarded, the crosslinking and main chain scission are accelerated, and the disappearance of hydrogen and formation and disappearance of trans-vinylene unsaturation are almost entirely unaffected. On the basis of these results the reactions induced by ..gamma.. rays in graft polymer were discussed in connection with the reaction mechanisms of the ..gamma.. radiolyses of polyethylene and polystyrene.

  1. Gamma photometric redshifts for long gamma-ray bursts

    CERN Document Server

    Bagoly, Z; Mészáros, A; Mészáros, P; Horváth, I; Balázs, L G; Vavrek, R

    2003-01-01

    It is known that the soft tail of the gamma-ray bursts' spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy channels. This effect allows to estimate the redshift of the bright long gamma-ray bursts in the BATSE Catalog. A verification of these redshifts is obtained for the 8 GRB which have both BATSE DISCSC data and measured optical spectroscopic redshifts. There is good correlation between the measured and esti redshifts, and the average error is $\\Delta z \\approx 0.33$. The method is similar to the photometric redshift estimation of galaxies in the optical range, hence it can be called as "gamma photometric redshift estimation". The estimated redshifts for the long bright gamma-ray bursts are up to $z \\simeq 4$. For the the faint long bursts - which should be up to $z \\simeq 20$ - the redshifts cannot be determined unambiguously with this method.

  2. Towards an improved understanding of eta --> gamma^* gamma^*

    CERN Document Server

    Xiao, C W; Hanhart, C; Kubis, B; Meißner, U -G; Wirzba, A

    2015-01-01

    We argue that high-quality data on the reaction $e^+e^-\\to \\pi^+\\pi^-\\eta$ will allow one to determine the double off-shell form factor $\\eta \\to \\gamma^*\\gamma^*$ in a model-independent way with controlled accuracy. This is an important step towards a reliable evaluation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. When analyzing the existing data for $e^+e^- \\to \\pi^+\\pi^-\\eta$ in the range of total energies $1\\text{GeV}^2gamma^*\\gamma^*}(Q_1^2,Q_2^2)$ is consistent with the commonly employed factorization ansatz at least for $Q_1^2<1\\text{GeV}^2$, if the effect of the $a_2$ meson is taken into account. However, better data are needed to draw firm conclusions.

  3. ATLAS Searches for VH, HH, VV, V+$\\gamma$/$\\gamma\\gamma$ Resonances

    CERN Document Server

    Biesuz, Nicolo Vladi; The ATLAS collaboration

    2017-01-01

    The discovery of a Higgs boson at the Large Hadron Collider motivates searches for physics beyond the Standard Model in channels involving coupling to the Higgs boson. A search for massive resonances decaying into couples of bosons is described. The considered final states are: $HH$, $VH$, $VV$, $V\\gamma$ and $\\gamma\\gamma$ with $V$ indicating either the $W$ or the $Z$ boson. Final states with different number of leptons or photons and where, in many cases, at least one Higgs decays into a b-quark pair are studied using different jet reconstruction techniques which allow to optimize the signal acceptance for low or Higgs boson transverse momentum. The most recent diboson resonance searches using LHC Run 2 data are described.

  4. The Gamma-ray Sky with Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.J. [NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 (United States)

    2013-10-15

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent limit on Lorentz invariance violation derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure in the direction of the center of our Galaxy, and strong constraints on some Weakly Interacting Massive Particle (WIMP) models for dark matter.

  5. A Double Inequality for Gamma Function

    Directory of Open Access Journals (Sweden)

    Xiaoming Zhang

    2009-01-01

    Full Text Available Using the Alzer integral inequality and the elementary properties of the gamma function, a double inequality for gamma function is established, which is an improvement of Merkle's inequality.

  6. Cosmic Rays: What Gamma Rays Can Say

    OpenAIRE

    2014-01-01

    We will review the main channels of gamma ray emission due to the acceleration and propagation of cosmic rays, discussing the cases of both galactic and extra-galactic cosmic rays and their connection with gamma rays observations.

  7. The Gamma-ray Universe through Fermi

    Science.gov (United States)

    Thompson, David J.

    2012-01-01

    Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  8. Search for Anomalous $ZZ\\gamma$ and $Z\\gamma\\gamma$ couplings in the process $e^{+}e^{-} \\to Z\\gamma$ at LEP

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; Durán, I; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lassila-Perini, K M; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marchesini, P A; Marian, G; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Molnár, P; Moulik, T; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Rubio, Juan Antonio; Ruggiero, G; Ruschmeier, D; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Sciarrino, D; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zöller, M

    2000-01-01

    We search for anomalous trilinear gauge couplings in the ${\\rm ZZ}\\gamma$ and ${\\rm Z}\\gamma\\gamma$ vertices using data collected with the L3 detectorat LEP at a centre--of--mass energy $\\sqrt{s}=189$ GeV. No evidence is found and limits on these couplings and on new physics scales are derived from the analysis of the process ${\\rm e}^{+}{\\rm e}^{-} \\rightarrow {\\rm Z} \\gamma$.

  9. Chiral-loop and vector-meson contributions to $\\eta \\to \\pi \\pi \\gamma \\gamma$ decays

    CERN Document Server

    Ametller, L; Bramon, A; Talavera, P; Ametller, Ll.

    1997-01-01

    The process eta -> pi0 pi0 gamma gamma is discussed in Chiral Perturbation Theory (ChPT) extending two recent analyses. Special attention is devoted to one-loop corrections, eta-eta' mixing effects and vector-meson dominance of ChPT counter-terms. The less interesting eta -> pi^+ pi^- gamma gamma transition is briefly discussed too.

  10. A New Search for tau -> mu gamma and tau -> e gamma Decays at Belle

    CERN Document Server

    Abe, K; Aihara, H; Anipko, D; Aoki, K; Arakawa, T; Arinstein, K; Asano, Y; Aso, T; Aulchenko, V M; Aushev, T; Aziz, T; Bahinipati, S; Bakich, A M; Balagura, V; Ban, Y; Banerjee, S; Barberio, E; Barbero, M; Bay, A; Bedny, I; Belous, K S; Bitenc, U; Bizjak, I; Blyth, S; Bondar, A; Bozek, A; Bracko, M; Brodzicka, J; Browder, T E; Chang, M C; Chang, P; Chao, Y; Chen, A; Chen, K F; Chen, W T; Cheon, B G; Chistov, R; Choi, J H; Choi, S K; Choi, Y; Choi, Y K; Chuvikov, A; Cole, S; Dalseno, J; Danilov, M; Dash, M; Dowd, R; Dragic, J; Drutskoy, A; Eidelman, S; Enari, Y; Epifanov, D A; Fratina, S; Fujii, H; Fujikawa, M; Gabyshev, N; Garmash, A; Gershon, T; Go, A; Gokhroo, G; Goldenzweig, P; Golob, B; Gorisek, A; Grosse-Perdekamp, M; Guler, H; Ha, H; Haba, J; Hara, K; Hara, T; Hasegawa, Y; Hastings, N C; Hayasaka, K; Hayashii, H; Hazumi, M; Heffernan, D; Higuchi, T; Hinz, L; Hokuue, T; Hoshi, Y; Hoshina, K; Hou, S; Hou, W S; Hsiung, Y B; Igarashi, Y; Iijima, T; Ikado, K; Imoto, A; Inami, K; Ishikawa, A; Ishino, H; Itoh, K; Itoh, R; Iwabuchi, M; Iwasaki, M; Iwasaki, Y; Jacoby, C; Jones, M; Kakuno, H; Kang, J H; Kang, J S; Kapusta, P; Kataoka, S U; Katayama, N; Kawai, H; Kawasaki, T; Khan, H R; Kibayashi, A; Kichimi, H; Kikuchi, N; Kim, H J; Kim, H O; Kim, J H; Kim, S K; Kim, T H; Kim, Y J; Kinoshita, K; Kishimoto, N; Korpar, S; Kozakai, Y; Krizan, P; Krokovnyi, P P; Kubota, T; Kulasiri, R; Kumar, R; Kuo, C C; Kurihara, E; Kusaka, A; Kuzmin, A; Kwon, Y J; Lange, J S; Leder, G; Lee, J; Lee, S E; Lee, Y J; Lesiak, T; Li, J; Limosani, A; Lin, C Y; Lin, S W; Liu, Y; Liventsev, D; MacNaughton, J; Majumder, G; Mandl, F; Marlow, D; Matsumoto, T; Matyja, A; McOnie, S; Medvedeva, T; Mikami, Y; Mitaroff, W A; Miyabayashi, K; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Mohapatra, D; Moloney, G R; Mori, T; Müller, J; Murakami, A; Nagamine, T; Nagasaka, Y; Nakagawa, T; Nakahama, Y; Nakamura, I; Nakano, E; Nakao, M; Nakazawa, H; Natkaniec, Z; Neichi, K; Nishida, S; Nishimura, K; Nitoh, O; Noguchi, S; Nozaki, T; Ogawa, A; Ogawa, S; Ohshima, T; Okabe, T; Okuno, S; Olsen, S L; Ono, S; Ostrowicz, W; Ozaki, H; Pakhlov, P; Pakhlova, G; Palka, H; Park, C W; Park, H; Park, K S; Parslow, N; Peak, L S; Pernicka, M; Pestotnik, R; Peters, M; Piilonen, L E; Poluektov, A; Ronga, F J; Root, N; Rorie, J; Rózanska, M; Sahoo, H; Saitoh, S; Sakai, Y; Sakamoto, H; Sakaue, H; Sarangi, T R; Sato, N; Satoyama, N; Sayeed, K; Schietinger, T; Schneider, O; Schonmeier, P; Schümann, J; Schwanda, C; Schwartz, A J; Seidl, R; Seki, T; Senyo, K; Sevior, M E; Shapkin, M; Shen, Y T; Shibuya, H; Shwartz, B; Sidorov, V; Singh, J B; Sokolov, A; Somov, A; Soni, N; Stamen, R; Stanic, S; Staric, M; Stöck, H; Sugiyama, A; Sumisawa, K; Sumiyoshi, T; Suzuki, S; Suzuki, S Y; Tajima, O; Takada, N; Takasaki, F; Tamai, K; Tamura, N; Tanabe, K; Tanaka, M; Taylor, G N; Teramoto, Y; Tian, X C; Tikhomirov, I; Trabelsi, K; Tsai, Y T; Tse, Y F; Tsuboyama, T; Tsukamoto, T; Uchida, K; Uchida, Y; Uehara, S; Uglov, T; Ueno, K; Unno, Y; Uno, S; Urquijo, P; Ushiroda, Y; Usov, Yu; Varner, G; Varvell, K E; Villa, S; Wang, C C; Wang, C H; Wang, M Z; Watanabe, M; Watanabe, Y; Wicht, J; Widhalm, L; Wiechczynski, J; Won, E; Wu, C H; Xie, Q L; Yabsley, B D; Yamaguchi, A; Yamamoto, H; Yamamoto, S; Yamashita, Y; Yamauchi, M; Heyoung Yang; Yoshino, S; Yuan, Y; Yusa, Y; Zang, S L; Zhang, C C; Zhang, J; Zhang, L M; Zhang, Z P; Zhilich, V; Ziegler, T; Zupanc, A; Zürcher, D

    2006-01-01

    We update our search for the lepton flavor violating tau -> mu gamma and tau -> e gamma decays based on 535/fb of data accumulated at the Belle experiment. No signal is found and we set preliminary 90% confidence level upper limits: B(tau -> mu gamma) e gamma) < 1.2x 10^-7.

  11. Novae in gamma-rays

    CERN Document Server

    Hernanz, M

    2013-01-01

    Classical novae produce radioactive nuclei which are emitters of gamma-rays in the MeV range. Some examples are the lines at 478 and 1275 keV (from 7Be and 22Na) and the positron-electron annihilation emission (511 keV line and a continuum below this energy, with a cut-off at 20-30 keV). The analysis of gamma-ray spectra and light curves is a potential unique and powerful tool both to trace the corresponding isotopes and to give insights on the properties of the expanding envelope determining its transparency. Another possible origin of gamma-rays is the acceleration of particles up to very high energies, so that either neutral pions or inverse Compton processes produce gamma-rays of energies larger than 100 MeV. MeV photons during nova explosions have not been detected yet, although several attempts have been made in the last decades; on the other hand, GeV photons from novae have been detected in some particular novae, in symbiotic binaries, where the companion is a red giant with a wind, instead of a main ...

  12. Short duration gamma ray bursts

    Indian Academy of Sciences (India)

    Patrick Das Gupta

    2004-10-01

    After a short review of gamma ray bursts (GRBs), we discuss the physical implications of strong statistical correlations seen among some of the parameters of short duration bursts (90 < 2 s). Finally, we conclude with a brief sketch of a new unified model for long and short GRBs.

  13. Effect of gamma irradiation on the thermal and rheological properties of grain amaranth starch

    Energy Technology Data Exchange (ETDEWEB)

    Kong Xiangli [School of Biological Sciences, University of Hong Kong, Pokfulam Road, Hong Kong (China); Kasapis, Stefan [School of Applied Sciences, RMIT University, City Campus, Melbourne, Vic 3001 (Australia); Bao Jinsong [Institute of Nuclear Agricultural Sciences, Key Laboratory of Zhejiang Province and Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Zhejiang University, Huajiachi Campus, Hangzhou 310029 (China); Corke, Harold [School of Biological Sciences, University of Hong Kong, Pokfulam Road, Hong Kong (China)], E-mail: hcorke@yahoo.com

    2009-11-15

    Physical properties of starch from two cultivars of gamma-irradiated grain amaranth with different amylose content were investigated. Pasting viscosities decreased continuously with the increase in dosages of irradiation. Furthermore, different irradiation dosages resulted in modification of the thermal properties and crystallinity of starch. Dynamic oscillation on shear was also employed, temperature and frequency sweeps showed that changes in storage modulus and loss modulus were significant, with Tibet Yellow producing more elastic gels as compared to Hy030 at different irradiation dosages.

  14. Effect of gamma irradiation on the thermal and rheological properties of grain amaranth starch

    Science.gov (United States)

    Kong, Xiangli; Kasapis, Stefan; Bao, Jinsong; Corke, Harold

    2009-11-01

    Physical properties of starch from two cultivars of gamma-irradiated grain amaranth with different amylose content were investigated. Pasting viscosities decreased continuously with the increase in dosages of irradiation. Furthermore, different irradiation dosages resulted in modification of the thermal properties and crystallinity of starch. Dynamic oscillation on shear was also employed, temperature and frequency sweeps showed that changes in storage modulus and loss modulus were significant, with Tibet Yellow producing more elastic gels as compared to Hy030 at different irradiation dosages.

  15. Influence of Water Potential on gamma-Decalactone Production by the Yeast Sporidiobolus salmonicolor.

    Science.gov (United States)

    Gervais, P; Battut, G

    1989-11-01

    The influence of water potential on gamma-decalactone production by the yeast Sporidiobolus salmonicolor cultivated in a liquid medium was evaluated by gas-chromatographic analysis. Modifications in water potential led to a number of variations in the aroma production. Maximum extracellular production occurred at water activity (a(w)) with a value of 0.99. Further analyses revealed an important phenomenon of cellular accumulation of aroma for a(w) values between 0.97 and 0.99.

  16. SNM gamma-ray fingerprint monitor functional requirements and design specifications

    Energy Technology Data Exchange (ETDEWEB)

    Bieber, A.M. Jr.; Kane, W.R.

    1994-07-01

    A number of DOE facilities need to perform confirmatory inventory measurements on items of special nuclear material (SNM). The DOE Office of Safeguards and Security (OSS) has tasked the Safeguards, Safety and Nonproliferation Division (SSN) of the Department of Advanced Technology at Brookhaven National Laboratory (BNL) to develop a high-resolution gamma-ray-spectroscopy-based instrument for performing confirmatory inventory measurements on such materials, a ``gamma-ray fingerprint monitor`` (GRFM). This document is a conceptual design for the SSN GRFM system. This conceptual design is based on previous experience with measurements of plutonium-bearing materials and comparison of gamma-ray spectrum features, not on actual tests of the procedures or hardware described. As a result, modifications may be necessary when actual prototype hardware and software are tested in realistic circumstances on actual materials of interest.

  17. Thermal analysis evaluation of mechanical properties changes promoted by gamma radiation on surgical polymeric textiles

    Science.gov (United States)

    Ferreira, L. M.; Casimiro, M. H.; Oliveira, C.; Cabeço Silva, M. E.; Marques Abreu, M. J.; Coelho, A.

    2002-05-01

    The large number of surgical operations with post-operative infection problems and the appearing of new infectious diseases, contribute to the development of new materials in order to answer the needs of health care services. This development must take into account the modifications promoted by sterilisation methods in materials, namely by gamma radiation. The differential scanning calorimetry (DSC) and thermogravimetry (TGA) techniques show that a nonwoven and a laminate textiles maintain a good molecular cohesion, do not showing high levels of degradation, for gamma radiation dose values lower than 100 kGy in nonwoven and 200 kGy in laminate materials. The tensile strength and the elongation decrease slowly for the nonwoven textile and decrease faster for the laminate textile for 25 and 80 kGy absorbed dose. This paper shows that the DSC and TGA techniques can be helpful for the prevision of mechanical changes occurred in the materials as a consequence of the gamma irradiation.

  18. Gamma and Related Functions Generalized for Sequences

    Science.gov (United States)

    Ollerton, R. L.

    2008-01-01

    Given a sequence g[subscript k] greater than 0, the "g-factorial" product [big product][superscript k] [subscript i=1] g[subscript i] is extended from integer k to real x by generalizing properties of the gamma function [Gamma](x). The Euler-Mascheroni constant [gamma] and the beta and zeta functions are also generalized. Specific examples include…

  19. The topological filtration of gamma-structures

    DEFF Research Database (Denmark)

    Li, T. J.; Reidys, C. M.

    2013-01-01

    In this paper we study gamma-structures filtered by topological genus. gamma-structures are a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A gamma-structure is composed by specific building blocks, that have topol...

  20. Gamma-Ray Interactions for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-02

    This presentation is a part of the DHS LSS spectroscopy training course and presents an overview of the following concepts: identification and measurement of gamma rays; use of gamma counts and energies in research. Understanding the basic physics of how gamma rays interact with matter can clarify how certain features in a spectrum were produced.

  1. Modulation of Enzymatic Activities of Dual Functional Peroxiredoxin by Gamma Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Hyun; Lee, Seung Sik; Park, Chul Hong; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2012-05-15

    Recently, enzymes have frequently been used as catalysts in various bio-industrial, commercial, and pharmaceutical applications, because they are more stable, more efficient, and less toxic than the synthetic catalysts. However, one of their major disadvantages is their low thermostability, which leads the researchers to develop new forms of industrially important enzymes with increased resistance to inactivation and aggregation. This study describes a strategy for modifying the molecular chaperone activity of peroxiredoxin (Prx) by using gamma irradiation. Prxs are a ubiquitous family of antioxidant enzymes. Upon oxidation of their peroxidatic Cys, the molecules undergo a structural conversion from a low-molecular-weight (LMW) species acting as a peroxidase to a high-molecular-weight (HMW) complex functioning as a chaperone. In the present study, we examined the effect of gamma irradiation on PP1084 with respect to its protein structure and enzymatic function. The use of gamma irradiation as a physical treatment can increase the cohesive strength of the protein by forming cross-links. The aims of the present work were (1) to improve the chaperone activity of PP1084 by gamma irradiation, (2) to identify the 'optimal' intensity of gamma irradiation, and (3) to investigate the influence of gamma irradiation on protein hydrophobicity as related to chaperone function. Following PP1084 treatment with 30 kGy gamma irradiation, the PP1084 chaperone activity enhanced by about 3-4-fold compared with nonirradiated PP1084, while the peroxidase activity decreased. Ongoing research efforts are addressing the physical modifications of PP1084 protein by gamma irradiation

  2. Modification to the Klein-Nishina cross section for Ge electrons at high statistics limit

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.F.

    1995-11-03

    Modification factors for the Klein-Nishina cross-sections for gamma-ray with energies between 50 keV and 250 keV incident on Ge electrons have been obtained at the high statistics limit. In this limit, the Ge electrons can then be treated as they are obtained from the self-consistent augmented plane wave calculations, without considering the orientation of crystal lattice with respect to incident photons. The kinematics corrections (i.e. outgoing momenta), on the other hand, have to be taken into account on an event by event basis. Even so, the computing time has been reduced dramatically since the relativistic calculation of the modifications to the Klein-Nishina cross sections is the most tedious one. The modification factors are almost linear with respect to incident photon energy in the interesting energy range with respect to a given photon outgoing angle.

  3. UV and gamma irradiation effects on surface properties of polyurethane derivative from castor oil

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Elaine C.; Nascimento, Eduardo M., E-mail: helunica@yahoo.com.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Chierice, Gilberto O.; Claro Neto, Salvador [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Lepienski, Carlos M. [Universidade Federal do Parana (UFPR), Curitiba (Brazil)

    2013-07-01

    Gamma and ultraviolet radiation effects on hardness, elastic modulus and viscoelastic properties of polyurethane derived from castor oil (PU) were investigated by nanoindentation tests. Modifications on surface morphology, induce by radiation, were observed by atomic force microscopy. The polyurethane derivative from castor oil shows good resistance to gamma radiation, with only small changes in hardness, elastic modulus, viscoelastic properties and contact angle. The hardness of PY increases at the near surface region due to UVA radiation and decreases after UVC radiation. The contact angle for water drop decreases after UVC radiation, by not after gamma radiation, despite a significant increase in roughness. Such results are attributed to different responses from polyurethane to radiation energy. Increase in hardness due to UVA is attributed to a higher crosslinking at shallow depths, while a decrease in mechanical properties may be attributed to chain scission. These results are consistent with the modifications on viscoelastic properties. Shore D hardness did not show the same trend as observed by nanoindentation results. Hardness, viscoelastic properties and contact angle of castor oil polyurethane are more severely influenced by UVC radiation, while gamma radiation does not have a significant effect. (author)

  4. UV and gamma irradiation effects on surface properties of polyurethane derivate from castor oil

    Directory of Open Access Journals (Sweden)

    Elaine C. Azevedo

    2013-01-01

    Full Text Available Gamma and ultraviolet radiation effects on hardness, elastic modulus and viscoelastic properties of polyurethane derived from castor oil (PU were investigated by nanoindentation tests. Modifications on surface morphology, induced by radiation, were observed by atomic force microscopy. The polyurethane derivate from castor oil shows good resistance to gamma radiation, with only small changes in hardness, elastic modulus, viscoelastic properties and contact angle. The hardness of PU increases at the near surface region due to UVA radiation and decreases after UVC radiation. The contact angle for water drop decreases after UVC radiation, but not after gamma radiation, despite a significant increase in roughness. Such results are attributed to different responses from polyurethane to radiation energy. Increase in hardness due to UVA is attributed to a higher crosslinking at shallow depths, while a decrease in mechanical properties may be attributed to chain scission. These results are consistent with the modifications on viscoelastic properties. Shore D hardness did not show the same trend as observed by nanoindentation results. Hardness, viscoelastic properties and contact angle of castor oil polyurethane are more severely influenced by UVC radiation, while gamma radiation does not have a significant effect.

  5. Aging of magnesium stearate under high doses gamma irradiation and oxidative conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lebeau, D.; Beuvier, L.; Cornaton, M. [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France); Miserque, F. [CEA, DEN, DPC, SCCME, LECA, F-91191 Gif-sur-Yvette (France); Tabarant, M. [CEA, DEN, DPC, SEARS, LISL, F-91191 Gif-sur-Yvette (France); Esnouf, S. [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France); Ferry, M., E-mail: muriel.ferry@cea.fr [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France)

    2015-05-15

    Highlights: • Magnesium stearate was radio-oxidized at very high doses using gamma-rays. • H{sub 2} emission was estimated as a function of the integrated dose. • Modifications in the organic solid were followed as a function of the integrated dose. • A non-exhaustive degradation mechanism of magnesium stearate was proposed. - Abstract: In nuclear waste packages conditioning processes, magnesium stearate is widely used because of its high lubricating properties. For safety purposes, the radiolytic degradation of these organic materials has to be better understood to be able to predict their aging in repository conditions. This study reports the radiolytic degradation of magnesium stearate, using gamma-rays at room temperature and under air. Modifications were followed using different analytical tools (XPS, ATR-FTIR, ICP-AES, ATG and mass spectrometry). It has been observed that molecules mainly formed up to 1000 kGy of gamma irradiation dose under radio-oxidation are alkanes, hydroperoxides, double bonds in the aliphatic chain, carboxylates with aliphatic chain shorter than the one of stearate and ketones. At a dose of 4000 kGy, dicarboxylic acids are observed: the formation of these molecules needs a dose of at least 1000 kGy to be created under radio-oxidation. These observations allow us to propose a non-exhaustive degradation mechanism of magnesium stearate under gamma-irradiation at room temperature and under air.

  6. Branching Fraction Measurements of B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Ben-Haim, E; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Bettarini, S; Bettoni, D; Bevan, A J; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Boyd, J T; Bozzi, C; Brandt, T; Brau, J E; Briand, H; Brown, D N; Bruinsma, M; Brunet, S; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Castelli, G; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Dasu, S; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Escalier, M; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, W T; Forster, I J; Forti, F; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Koeneke, K; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, W; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lang, M I; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, F; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martin, E C; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Morris, J P; Muheim, F; Müller, D R; Nagel, M; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro-Vazquez, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Pelliccioni, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petrella, A; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Piredda, G; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prencipe, E; Prepost, R; Pripstein, M; Prudent, X; Pruvot, S; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rahmat, R; Rama, M; Ratcliff, B N; Raven, G; Regensburger, J J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roberts, D A; Robertson, A I; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Röthel, W; Sacco, R; Saeed, M A; Saleem, M; Salnikov, A A; Salvati, E; Salvatore, F; Sanders, D A; Santroni, A; Saremi, S; Schalk, T; Schenk, S; Schilling, C J; Schindler, R H; Schofield, K C; Schott, G; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Serrano, J; Sharma, V; Shen, B C; Sherwood, D J; Simard, M; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Tackmann, K; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Thiebaux, C; Thompson, J M; Tisserand, V; Todyshev, K Yu; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasseur, G; Vavra, J; Verderi, M; Viaud, F B; Vitale, L; Voci, C; Voena, C; Volk, A; Wacker, K; Wagner, A P; Wagner, S R; Waldi, R; Walker, D; Walsh, J J; Wang, P; Wang, W F; Wappler, F R; Watson, A T; Weaver, M; Wenzel, W A; West, T J; Wilden, L; Williams, D C; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winklmeier, F; Winstrom, L O; Wisniewski, W J; Wittgen, M; Wong, Q K; Wormser, G; Wren, A C; Wright, D H; Wright, D M; Wu, J; Wu, S L; Wulsin, H W; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J I; Yi, K; Yi, M; Young, C C; Yu, Z; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T; al, et

    2006-01-01

    We present a study of the decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma. The analysis is based on data containing 347 million BBbar events recorded with the BaBar detector at the PEP-II asymmetric B factory. We measure the branching fractions BR(B+ -> rho+ gamma) = (1.10 +0.37/-0.33 +/- 0.09) x 10-6 and BR(B0 -> rho0 gamma) = (0.79 +0.22/-0.20 +/- 0.06) x 10-6, and set a 90% C.L. upper limit BR(B0 -> omega gamma) rho/omega gamma) = (1.25 +0.25/-0.24 +/- 0.09) x 10-6, from which we determine |Vtd/Vts| = 0.200 +0.021/-0.020 +/- 0.015, where the first uncertainty is experimental and the second is theoretical.

  7. Medium Modification of Vector Mesons

    Energy Technology Data Exchange (ETDEWEB)

    Chaden Djalali, Michael Paolone, Dennis Weygand, Michael H. Wood, Rakhsha Nasseripour

    2011-03-01

    The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance scale experiments has been a major challenge. Various QCD-inspired models predict a partial restoration of chiral symmetry in nuclear matter with modifications of the properties of hadrons from their free-space values. Measurable changes such as a shift in mass and/or a change of width are predicted at normal nuclear density. Photoproduction of vector mesons off nuclei have been performed at different laboratories. The properties of the ρ, ω and φ mesons are investigated either directly by measuring their mass spectra or indirectly through transparency ratios. The latest results regarding medium modifications of the vector mesons in the nuclear medium will be discussed.

  8. Posttranslational modification and quality control.

    Science.gov (United States)

    Wang, Xuejun; Pattison, J Scott; Su, Huabo

    2013-01-18

    Protein quality control functions to minimize the level and toxicity of misfolded proteins in the cell. Protein quality control is performed by intricate collaboration among chaperones and target protein degradation. The latter is performed primarily by the ubiquitin-proteasome system and perhaps autophagy. Terminally misfolded proteins that are not timely removed tend to form aggregates. Their clearance requires macroautophagy. Macroautophagy serves in intracellular quality control also by selectively segregating defective organelles (eg, mitochondria) and targeting them for degradation by the lysosome. Inadequate protein quality control is observed in a large subset of failing human hearts with a variety of causes, and its pathogenic role has been experimentally demonstrated. Multiple posttranslational modifications can occur to substrate proteins and protein quality control machineries, promoting or hindering the removal of the misfolded proteins. This article highlights recent advances in posttranslational modification-mediated regulation of intracellular quality control mechanisms and its known involvement in cardiac pathology.

  9. Laser surface modification and adhesion

    CERN Document Server

    Mittal, K L

    2014-01-01

    The book provides a unique overview on laser techniques and applications for the purpose of improving adhesion by altering surface chemistry and topography/morphology of the substrate. It details laser surface modification techniques for a wide range of industrially relevant materials (plastics, metals, ceramics, composites) with the aim to improve and enhance their adhesion to other materials. The joining of different materials is of critical importance in the fabrication of many and varied products.

  10. Synthesis and Modification of Clinoptilolite

    OpenAIRE

    Pavlina Ambrozova; Jindrich Kynicky; Tomas Urubek; Vinh Dinh Nguyen

    2017-01-01

    Clinoptilolite is a natural mineral with exceptional physical characteristics resulting from its special crystal structure, mainstreamed into a large zeolite group called heulandites. An overall view of the research related to the synthesis, modification and application of synthetic clinoptilolite is presented. A single phase of clinoptilolite can be hydrothermally synthesized for 1–10 days in an autoclave from various silica, alumina, and alkali sources with initial Si/Al ratio from 3.0 to 5...

  11. [Advances in genetic modification technologies].

    Science.gov (United States)

    Zhang, Baixue; Sun, Qixin; Li, Haifeng

    2015-08-01

    Genetic modification technology is a new molecular tool for targeted genome modification. It includes zinc finger nucleases (ZFN) technology, transcription activator-like effector nucleases (TALEN) technology and clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) (CRISPR-Cas) nucleases technology. All of these nucleases create DNA double-strand breaks (DSB) at chromosomal targeted sites and induce cell endogenous mechanisms that are primarily repaired by the non-homologous end joining (NHEJ) or homologous recombination (HR) pathway, resulting in targeted endogenous gene knock-out or exogenous gene insertion. In recent years, genetic modification technologies have been successfully applied to bacteria, yeast, human cells, fruit fly, zebra fish, mouse, rat, livestock, cynomolgus monkey, Arabidopsis, rice, tobacco, maize, sorghum, wheat, barley and other organisms, showing its enormous advantage in gene editing field. Especially, the newly developed CRISPR-Cas9 system arose more attention because of its low cost, high effectiveness, simplicity and easiness. We reviewed the principles and the latest research progress of these three technologies, as well as prospect of future research and applications.

  12. A $\\gamma\\gamma$ Collider for the 750 GeV Resonant State

    CERN Document Server

    He, Min; Tang, Yong

    2016-01-01

    Recent data collected by ATLAS and CMS at 13 TeV collision energy of the LHC indicate the existence of a new resonant state $\\phi$ with a mass of 750 GeV decaying into two photons $\\gamma\\gamma$. The properties of $\\phi$ should be studied further at the LHC and also future colliders. Since only $\\phi \\to \\gamma\\gamma$ decay channel has been measured, one of the best ways to extract more information about $\\phi$ is to use a $\\gamma\\gamma$ collider to produce $\\phi$ at the resonant energy. In this work we show how $\\gamma\\gamma$ collider help to verify the existence of $\\phi$ and to provide some of the most important information about the properties of $\\phi$ such as branching fractions of $\\phi\\to V_1V_2$. Here $V_i$ can be $\\gamma$, $Z$, or $W^\\pm$. We also show that by studying angular distributions of the final $\\gamma$'s in $\\gamma\\gamma \\to \\phi \\to \\gamma\\gamma$, one can determine whether this state is a spin-0 or a spin-2 state.

  13. Measurement of the gamma gamma* -> pi0 transition form factor

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2009-06-02

    We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

  14. Chromatin proteins and modifications as drug targets

    DEFF Research Database (Denmark)

    Helin, Kristian; Dhanak, Dashyant

    2013-01-01

    A plethora of groundbreaking studies have demonstrated the importance of chromatin-associated proteins and post-translational modifications of histones, proteins and DNA (so-called epigenetic modifications) for transcriptional control and normal development. Disruption of epigenetic control...

  15. Laser source for the gamma-gamma collider

    CERN Document Server

    Early, J T

    2001-01-01

    The production of high energy gammas from collisions between the NLC high energy electrons and low energy photons places difficult requirements on the laser low energy photon source. The electrons are produced in macro-pulses at 120 Hz. Each macro-pulse consists of around 100 subpulses separated by 2.8 nanoseconds. To interact efficiently with the electrons the laser subpulses must have approximately a 2 picosecond pulse duration. The laser macro-pulse energy must be 100 joules per beam at 120 Hz, or a total laser average power of 24 kW. The Mercury laser consists of a Yb:S-FAP laser instead of the usual Nd-glass as it has better thermal conductivity for cooling, longer storage lifetime for efficient pumping, and a high quantum efficiency to minimise waste heat. The laser will operate at 10 Hz with 100 J pulses. Twelve such laser would have to be multiplexed to achieve the gamma - gamma laser requirements. (2 refs).

  16. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  17. Measurement of the $ \\mathrm{ Z } \\gamma \\rightarrow \

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, Vardan; et al.

    2016-02-23

    A measurement of the Z gamma to nu nu-bar gamma production cross section in pp collisions at sqrt(s) = 8 TeV is presented, using data corresponding to an integrated luminosity of 19.6 inverse-femtobarns collected with the CMS detector at the LHC. This measurement is based on the observation of events with large missing energy and with a single photon with transverse momentum above 145 GeV and absolute pseudorapidity in the range |eta| < 1.44. The measured Z gamma to nu nu-bar gamma production cross section, 52.7 +/- 2.1(stat) +/- 6.4 (syst) +/- 1.4 (lumi) fb, agrees well with the standard model prediction of 50.0+2.4-2.2 fb. A study of the photon transverse momentum spectrum yields the most stringent limits to date on the anomalous Z-Z-gamma and Z-gamma-gamma trilinear gauge boson couplings.

  18. Energy conservation potential of surface modification technologies

    Energy Technology Data Exchange (ETDEWEB)

    Le, H.K.; Horne, D.M.; Silberglitt, R.S.

    1985-09-01

    This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

  19. Gamma rays from dark matter

    CERN Document Server

    Bringmann, Torsten

    2011-01-01

    A leading hypothesis for the nature of the elusive dark matter are thermally produced, weakly interacting massive particles that arise in many theories beyond the standard model of particle physics. Their self-annihilation in astrophysical regions of high density provides a potential means of indirectly detecting dark matter through the annihilation products, which nicely complements direct and collider searches. Here, I review the case of gamma rays which are particularly promising in this respect: distinct and unambiguous spectral signatures would not only allow a clear discrimination from astrophysical backgrounds but also to extract important properties of the dark matter particles; powerful observational facilities like the Fermi Gamma-ray Space Telescope or upcoming large, ground-based Cherenkov telescope arrays will be able to probe a considerable part of the underlying, e.g. supersymmetric, parameter space. I conclude with a more detailed comparison of indirect and direct dark matter searches, showing...

  20. Temperature dependence of gamma-gamma prime lattice mismatch in nickel-base superalloys

    Science.gov (United States)

    Nathal, M. V.; Mackay, R. A.; Garlick, R. G.

    1985-01-01

    High temperature X-ray diffraction techniques were used to determine the gamma-gamma prime lattice mismatch of three different nickel-base superalloys at temperatures between 18 and 1000 C. The measurements were performed on oriented single-crystal disks which had been aged to produce a semicoherent gamma-gamma prime structure. The thermal expansion of the lattice parameters of the gamma and gamma-prime phases was described by a second-order polynomial expression. The expansion of the gamma-prime phase was consistently smaller than that of the gamma phase, which caused the lattice mismatch to become more negative at higher temperatures. It was also shown that high values of lattice mismatch resulted in increased rates of directional gamma-prime coarsening during elevated temperature creep exposure.

  1. Supernovae and Gamma Ray Bursts

    Directory of Open Access Journals (Sweden)

    M. Della Valle

    2007-01-01

    Full Text Available Se revisa el estatus observacional de la conexi on Supernova (SN/Estallido de Rayos-Gamma (GRB. Recientes (y no tan recientes observaciones de GRBs largos sugieren que una fracci on signi cativa de ellos (pero no todos est an asociados con supernovas brillantes del tipo Ib/c. Estimaciones actuales de las tasas de producci on de GRBs y SNs dan una raz on para GRB/SNe-Ibc en el rango 0:4%

  2. Gamma knife therapy for craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Tatsuya; Kida, Yoshihisa; Tanaka, Takayuki; Yoshida, Kazuo; Yoshimoto, Masayuki; Maezawa, Satoshi; Hasegawa, Toshinori [Komaki Hospital, Aichi (Japan)

    1997-01-01

    Gamma knife therapy in stereotactic radiosurgery was evaluated as a tool to solve problems raised in therapy for craniopharyngioma. Subjects were 9 childhood patients (<16 y, mean age 9.75 y) and 16 adult patients (mean age 43.9 y), 23 cases of whom had been treated with surgery before gamma knife. Planning of irradiation to the solid part of the tumor was based on their T1-weighted MRI images of 3 mm-thick slice. The mean size of the tumors was 20.7 (9.6-31.2) mm in diameter. The mean central dose of 23.3 (20-30) Gy was irradiated with the mean marginal dose of 11.8 (18-11.3) Gy through the mean shot of 4.8. Results were followed in every 3-6 months by MRI, neurological and endocrinological examinations for 7-52 (mean 23.3) months. Reduction of tumor size including its disappearance (7 cases) were observed in 22 cases (88%) with adverse effects of hypopituitarism (3 cases) and hemianopsia (1). Gamma knife therapy was thus safe and effective. (K.H.)

  3. DUAL Gamma-Ray Mission

    CERN Document Server

    Boggs, S; von Ballmoos, P; Takahashi, T; Gehrels, N; Tueller, J; Baring, M; Beacom, J; Diehl, R; Greiner, J; Grove, E; Hartmann, D; Hernanz, M; Jean, P; Johnson, N; Kanbach, G; Kippen, M; Knödlseder, J; Leising, M; Madejski, G; McConnell, M; Milne, P; Motohide, K; Nakazawa, K; Oberlack, U; Phlips, B; Ryan, J; Skinner, G; Starrfield, S; Tajima, H; Wulf, E; Zoglauer, A; Zych, A

    2010-01-01

    Gamma-ray astronomy presents an extraordinary scientific potential for the study of the most powerful sources and the most violent events in the Universe. In order to take full advantage of this potential, the next generation of instrumentation for this domain will have to achieve an improvement in sensitivity over present technologies of at least an order of magnitude. The DUAL mission concept takes up this challenge in two complementary ways: a very long observation of the entire sky, combined with a large collection area for simultaneous observations of Type Ia SNe. While the Wide-Field Compton Telescope (WCT) accumulates data from the full gamma-ray sky (0.1-10 MeV) over the entire mission lifetime, the Laue-Lens Telescope (LLT) focuses on 56Co emission from SNe Ia (0.8-0.9 MeV), collecting gamma-rays from its large area crystal lens onto the WCT. Two separated spacecraft flying in formation will maintain the DUAL payloads at the lens' focal distance.

  4. Drilling azimuth gamma embedded design

    Directory of Open Access Journals (Sweden)

    Zhou Yi Ren

    2016-01-01

    Full Text Available Embedded drilling azimuth gamma design, the use of radioactive measuring principle embedded gamma measurement while drilling a short section analysis. Monte Carlo method, in response to the density of horizontal well logging numerical simulation of 16 orientation, the orientation of horizontal well analysed, calliper, bed boundary location, space, different formation density, formation thickness, and other factors inclined strata dip the impact by simulating 137Cs sources under different formation conditions of the gamma distribution, to determine the orientation of drilling density tool can detect window size and space, draw depth of the logging methods. The data 360° azimuth imaging, image processing method to obtain graph, display density of the formation, dip and strata thickness and other parameters, the logging methods obtain real-time geo-steering. To establish a theoretical basis for the orientation density logging while drilling method implementation and application of numerical simulation in-depth study of the MWD azimuth and density log response factors of horizontal wells.

  5. Modified the optical and electrical properties of CR-39 by gamma ray irradiation

    Directory of Open Access Journals (Sweden)

    A.M. Abdul-Kader

    2014-07-01

    Full Text Available The radiation technique is a useful technology technique to induce suitable modifications of the polymeric materials. In the present work, poly allyl diglycol carbonate (CR-39 solid state nuclear track detector samples were irradiated using different doses (150–950 kGy of gamma ray irradiations. The effect of gamma ray irradiations on the optical and electrical, properties of CR-39 was investigated. The obtained results showed a decrease in the optical energy gap with increasing the gamma dose. Increase in the numbers of carbon atoms (N in a formed cluster with increasing the irradiation dose was observed. Meanwhile, an increase in the Ac conductivity was obtained with increasing the gamma dose. Also, the variation in the dielectric constant and loss with irradiation dose was studied at the room temperature. The results indicate that the gamma ray irradiations in the dose range 150–950 kGy enhance the optical and electrical properties of the CR-39 polymer samples.

  6. Epigenetic modifications and diabetic nephropathy

    Directory of Open Access Journals (Sweden)

    Marpadga A. Reddy

    2012-09-01

    Full Text Available Diabetic nephropathy (DN is a major complication associated with both type 1 and type 2 diabetes, and a leading cause of end-stage renal disease. Conventional therapeutic strategies are not fully efficacious in the treatment of DN, suggesting an incomplete understanding of the gene regulation mechanisms involved in its pathogenesis. Furthermore, evidence from clinical trials has demonstrated a “metabolic memory” of prior exposure to hyperglycemia that continues to persist despite subsequent glycemic control. This remains a major challenge in the treatment of DN and other vascular complications. Epigenetic mechanisms such as DNA methylation, nucleosomal histone modifications, and noncoding RNAs control gene expression through regulation of chromatin structure and function and post-transcriptional mechanisms without altering the underlying DNA sequence. Emerging evidence indicates that multiple factors involved in the etiology of diabetes can alter epigenetic mechanisms and regulate the susceptibility to diabetes complications. Recent studies have demonstrated the involvement of histone lysine methylation in the regulation of key fibrotic and inflammatory genes related to diabetes complications including DN. Interestingly, histone lysine methylation persisted in vascular cells even after withdrawal from the diabetic milieu, demonstrating a potential role of epigenetic modifications in metabolic memory. Rapid advances in high-throughput technologies in the fields of genomics and epigenomics can lead to the identification of genome-wide alterations in key epigenetic modifications in vascular and renal cells in diabetes. Altogether, these findings can lead to the identification of potential predictive biomarkers and development of novel epigenetic therapies for diabetes and its associated complications.

  7. MAP kinases and histone modification

    Institute of Scientific and Technical Information of China (English)

    Tamaki Suganuma; Jerry L. Workman

    2012-01-01

    Signal transduction pathways alter the gene expression program in response to extracellular or intracellular cues.Mitogen-activated protein kinases (MAPKs) govern numerous cellular processes including cell growth,stress response,apoptosis,and differentiation.In the past decade,MAPKs have been shown to regulate the transcription machinery and associate with chromatin-modifying complexes.Moreover,recent studies demonstrate that several MAPKs bind directly to chromatin at target genes.This review highlights the recent discoveries of MAPK signaling in regard to histone modifications and chromatin regulation.Evidence suggesting that further unknown mechanisms integrate signal transduction with chromatin biology is discussed.

  8. Mechanochemical modification of natural rubber

    Science.gov (United States)

    Mikhaylov, I. A.; Sukhareva, K. V.; Andriasyan, Yu. O.; Popov, A. A.; Vorontsov, N. V.

    2016-11-01

    Thermomechanochemical changes of SVR 3L natural rubber after the treatment in the internal rubber mixer in the self-heating mode were studied. The effect of the molecular mass and content of the gel fraction of natural rubber is shown. Properties of rubber compounds and vulcanized rubber are presented. Taking into account modern requirements, a new alternative technology of obtaining halogenated elastomers based on the solid-phase (mechanochemical) halide modification is created. New halogen-containing natural rubber produced by this technology proves themselves in the conditions of rubber production. New fluorinated natural rubber produced by this technology proves themselves in the conditions of rubber production.

  9. Chemical Modification of Food Proteins

    Institute of Scientific and Technical Information of China (English)

    Allaoua Achouri; Wang Zhang; Xu Shiying

    1999-01-01

    Acylation has been shown to be an effective tool for improving surface functional properties of plant proteins.Soy bean protein has been extensively modified through chemical and enzymatic treatments. Their effectiveness lies in their high nutritional value and low cost, which promote their use as ingredients for the formulation of food products.This paper reports a complete review of chemical modification of various proteins from plant and animal sources. The nutritive and toxicological aspects through in vitro and in vivo tests are also described.

  10. Modifications to Ivor Lewis esophagectomy.

    Science.gov (United States)

    David, Elizabeth A; Marshall, M Blair

    2010-11-01

    The surgical approach to esophagectomy is variable. A number of factors are considered when determining the optimal approach to esophagectomy: location and extent of disease, fibrosis, additional patient factors and surgeon preference. One of the disadvantages to some approaches is the need for a change in position, which increases operative time. Also, because typically the abdomen is initially explored, patients may later be deemed unresectable at thoracotomy. We describe time saving modifications to the standard Ivor Lewis esophagectomy that eliminate the need for repositioning and facilitate a stapled end-to-end anastomosis.

  11. [Bronchial morphologic modification in asthma].

    Science.gov (United States)

    Cataldo, D; Louis, R; Godon, A; Munaut, C; Noël, A; Foidart, J M; Bartsch, P

    2000-07-01

    Asthma is an inflammatory disease of the airways clinically characterised by recurrent bronchial obstructions at least partially reversible. Recent epidemiologic data suggest that asthmatics have an increased rate of decrease of their expiratory volumes during life. This irreversible lung function impairment is associated with fundamental structural changes of the bronchial wall in terms of conjunctive tissue and smooth muscle composition. We describe these changes and explore the different mechanisms proposed to explain these structural modifications. We also review their consequences in terms of bronchial physiology and their potential influence on bronchial hyperresponsiveness.

  12. Backgound Gluon Effects on $B \\rightarrow X_{S} \\gamma \\gamma$

    CERN Document Server

    Choudhury, S R; Yao, York-Peng

    1998-01-01

    We consider non-perturbative QCD effects on the energy spectrum of either one of the photons in B -> X_s gamma gamma. These are due to the subprocesses in which a charm quark loop interacts with a self-consistently produced background static QCD field. The magnitude is estimated to be a few percents in B -> X_s gamma gamma, but can be quite substantial in B_s -> gamma gamma. An extension of the Euler-Heisenberg Lagrangian is given.

  13. Search for the decay $K_{S} \\to \\pi^{0} \\gamma\\gamma$

    CERN Document Server

    Lai, A; Batley, J Richard; Bevan, A; Dosanjh, R S; Gershon, T J; Kalmus, George Ernest; Munday, D J; Olaiya, E; Parker, M A; White, T; Wotton, S A; Barr, G; Bocquet, G; Ceccucci, Augusto; Çuhadar-Dönszelmann, T; Cundy, Donald C; Doble, Niels T; Falaleev, V P; Gatignon, L; Gonidec, A; Gorini, B; Govi, G; Grafström, P; Kubischta, Werner; Lacourt, A; Lenti, M; Norton, A; Palestini, S; Panzer-Steindel, B; Tatishvili, G T; Taureg, Hans; Velasco, M; Wahl, H; Cheshkov, C; Khristov, P Z; Kekelidze, V D; Madigozhin, D T; Molokanova, N A; Potrebenikov, Yu K; Tkatchev, A; Zinchenko, A I; Knowles, I; Lazzeroni, C; Martin, V; Sacco, R; Walker, A; Contalbrigo, M; Dalpiaz, Pietro; Duclos, J; Frabetti, P L; Gianoli, A; Martini, M; Masetti, L; Petrucci, F; Savrié, M; Bizzeti, A; Calvetti, M; Collazuol, G; Graziani, G; Iacopini, E; Becker, H G; Eppard, M; Fox, H; Holtz, K; Kalter, A; Kleinknecht, K; Koch, U; Köpke, L; Lopes da Silva, P; Marouelli, P; Pellmann, I A; Peters, A; Renk, B; Schmidt, S A; Schönharting, V; Schué, Yu; Wanke, R; Winhart, A; Wittgen, M; Chollet, J C; Fayard, Louis; Iconomidou-Fayard, L; Ocariz, J; Unal, G; Wingerter-Seez, I; Anzivino, Giuseppina; Cenci, P; Imbergamo, E; Lubrano, P; Mestvirishvili, A; Nappi, A; Pepé-Altarelli, M; Piccini, M; Carosi, R; Casali, R; Cerri, C; Cirilli, M; Costantini, F; Fantechi, R; Giudici, Sergio; Mannelli, I; Pierazzini, G M; Sozzi, M; Chèze, J B; Cogan, J; De Beer, M; Debu, P; Formica, A; Granier de Cassagnac, R; Mazzucato, E; Peyaud, B; Turlay, René; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Arcidiacono, R; Biino, C; Cartiglia, N; Guida, R; Marchetto, R; Menichetti, E; Pastrone, N; Nassalski, J P; Rondio, Ewa; Szleper, M; Wislicki, W; Wronka, S; Dibon, Heinz; Fischer, G; Jeitler, Manfred; Markytan, Manfred; Mikulec, I; Neuhofer, Günther; Pernicka, Manfred; Taurok, Anton; Widhalm, L

    2003-01-01

    A search for the decay K/sub S/ to pi /sup 0/ gamma gamma has been made using the NA48 detector at the CERN SPS. Using data collected in 1999 during a 40-hour run with a high-intensity K/sub S/ beam, an upper limit for the branching ratio BR(K/sub S/ to pi /sup 0/ gamma gamma , z to >or= 0.2) < 3.3 * 10/sup -7/ has been obtained at 90% confidence level, where z = m/sub gamma gamma //sup 2//m(K/sub 0/) /sup 2/. (8 refs).

  14. Determination of the e{sup +}e{sup -}{yields}{gamma}{gamma}({gamma}) cross-section at LEP 2

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, J. [CNRS, Paris (France). LPNHE; Paris-6 Univ. (France); Abreu, P. [FCUL, Lisboa (Portugal). IST; Adam, W. [Warsaw Univ. (PL). Inst. Nuclear Studies] [and others

    2004-11-01

    A test of the benchmark QED process e{sup +}e{sup -}{yields}{gamma}{gamma}({gamma}) is reported, using the data collected with the DELPHI detector at LEP 2. The data analysed were recorded at centre-of-mass energies ranging from 161 GeV to 208 GeV and correspond to a total integrated luminosity of 656.4 pb{sup -1}. The Born cross-section for the process e{sup +}e{sup -}{yields}{gamma}{gamma}({gamma}) was determined, confirming the validity of QED at the highest energies ever attained in electron-positron collisions. Lower limits on the parameters of a number of possible deviations from QED, predicted within theoretical frameworks expressing physics beyond the Standard Model, were derived. (orig.)

  15. Evidence for $\\eta_{c} \\rightarrow \\gamma\\gamma$ and Measurement of $J/\\psi\\rightarrow 3\\gamma$

    CERN Document Server

    Ablikim, M; Ambrose, D J; An, F F; An, Q; An, Z H; Bai, J Z; Ban, Y; Becker, J; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Briere, R A; Bytev, V; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, Y B; Cheng, H P; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, L Y; Dong, M Y; Du, S X; Fang, J; Fang, S S; Fava, L; Feldbauer, F; Feng, C Q; Ferroli, R B; Fu, C D; Fu, J L; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y P; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, J S; Huang, X T; Huang, Y P; Hussain, T; Ji, C S; Ji, Q; Ji, X B; Ji, X L; Jiang, L L; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Jing, F F; Kalantar-Nayestanaki, N; Kavatsyuk, M; Kuehn, W; Lai, W; Lange, J S; Li, C H; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, K; Li, Lei; Li, Q J; Li, S L; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, X R; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Liao, X T; Liu, B J; Liu, C L; Liu, C X; Liu, C Y; Liu, F H; Liu, Fang; Liu, Feng; Liu, H; Liu, H B; Liu, H H; Liu, H M; Liu, H W; Liu, J P; Liu, K Y; Liu, Kai; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, X H; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lu, G R; Lu, H J; Lu, J G; Lu, Q W; Lu, X R; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Ma, C L; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Ma, Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Morales, C Morales; Motzko, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nicholson, C; Nikolaev, I B; Ning, Z; Olsen, S L; Ouyang, Q; Pacetti, S; Park, J W; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Prencipe, E; Qi, M; Qian, S; Qiao, C F; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Rong, G; Ruan, X D; Sarantsev, A; Schaefer, B D; Schulze, J; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, X Y; Spataro, S; Spruck, B; Sun, D H; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Toth, D; Ullrich, M; Varner, G S; Wang, B; Wang, B Q; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q; Wang, Q J; Wang, S G; Wang, X L; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z Y; Wei, D H; Weidenkaff, P; Wen, Q G; Wen, S P; Werner, M; Wiedner, U; Wu, L H; Wu, N; Wu, S X; Wu, W; Wu, Z; Xia, L G; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, G M; Xu, H; Xu, Q J; Xu, X P; Xu, Z R; Xue, F; Xue, Z; Yan, L; Yan, W B; Yan, Y H; Yang, H X; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, J S; Yu, S P; Yuan, C Z; Yuan, Y; Zafar, A A; Zallo, A; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y S; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, H S; Zhao, J W; Zhao, K X; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhong, J; Zhou, L; Zhou, X K; Zhou, X R; Zhu, C; Zhu, K; Zhu, K J; Zhu, S H; Zhu, X L; Zhu, X W; Zhu, Y C; Zhu, Y M; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

    2012-01-01

    The decay of $J/\\psi$ to three photons is studied using $\\psi^\\prime\\to\\pi^+\\pi^-J/\\psi$ in a sample of 106 million $\\psi^\\prime$ events collected with the BESIII detector. First evidence of the decay $\\eta_c\\to\\gamma\\gamma$ is reported, and the product branching fraction is determined to be $\\br{J/\\psi\\to\\gamma\\eta_c,\\eta_c\\to \\gamma\\gamma}=(4.5\\pm1.2\\pm0.6)\\times10^{-6}$, where the first error is statistical and the second systematic. The branching ratio for the direct decay is $\\br{J/\\psi\\to3\\gamma} = (11.3\\pm1.8\\pm2.0)\\times 10^{-6}$.

  16. The close-range gamma-graphy control - {gamma}-prox; Le controle par gammagraphie de proximite - {gamma}-prox

    Energy Technology Data Exchange (ETDEWEB)

    Blettner, A. [Institut de Soudure, 93 - Villepinte (France)

    2011-01-15

    This work deals with the {gamma}-prox: a modular device for proximity gamma-graphy. The dose rates obtained between the standard collimator and the {gamma}-prox are compared. A study, among the tools developed by the Welding Institute Industry, to estimate the occupational dosimetry is presented in order to determine the dose limits for a welding control of 255 mm diameter and 5 mm thickness, as well as the calculation of the signalling distances. (O.M.)

  17. Alterations induced in Escherichia Coli cells by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da [Federal University of Technology of Parana (CPGEI/UTFPR), Curitiba, PR (Brazil)]. E-mails: jaquekap@yahoo.com.br; schelin@cpgei.cefetpr.br; sergei@utfpr.edu.br; Jesus, E.F.O. de; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: ricardo@lin.ufrj.br; edgar@lin.ufrj.br; Carlin, N.; Toledo, E.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica]. E-mail: nelson.carlin@dfn.if.usp.br

    2007-07-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ({sup 60}Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

  18. New Scalar Contributions to $h\\to Z\\gamma$

    CERN Document Server

    Chen, Chian-Shu; Huang, Da; Tsai, Lu-Hsing

    2013-01-01

    We calculate the decay rate of $h\\to Z\\gamma$ by including the contributions from new scalars with arbitrary quantum numbers of the weak isospin ($T$) and hypercharge ($Y$) in the standard model. We find that our general formula for the decay rate of $h\\to Z\\gamma$ matches with that for $h\\to \\gamma\\gamma$ in the limit of $m_Z=0$, but it is different from those in the literature. To illustrate our result, by taking the current $2\\sigma$ excess of the $h\\to \\gamma\\gamma$rate measured by the LHC, we examine the corresponding shift for the $Z\\gamma$ decay channel due to the new scalar. We show that the enhancement or reduction of the $h\\to Z\\gamma$ rate only depends on the relative size of $T$ and the absolute value of $Y$. Explicitly, we predict $0.76gamma}\\equiv \\Gamma(h\\to Z\\gamma)/\\Gamma_{SM}(h\\to Z\\gamma)<2.05$ by imposing the observed range of $1.5gamma\\gamma}\\equiv \\Gamma(h\\to Z\\gamma\\gamma)/\\Gamma_{SM}(h\\to\\gamma\\gamma)<2$, which is independent of the number of multiplets and the c...

  19. DNA Modifications and Alzheimer's Disease.

    Science.gov (United States)

    Smith, Rebecca G; Lunnon, Katie

    2017-01-01

    Alzheimer's disease (AD) is a complex neurodegenerative disease, affecting millions of people worldwide. While a number of studies have focused on identifying genetic variants that contribute to the development and progression of late-onset AD, the majority of these only have a relatively small effect size. There are also a number of other risk factors, for example, age, gender, and other comorbidities; however, how these influence disease risk is not known. Therefore, in recent years, research has begun to investigate epigenetic mechanisms for a potential role in disease etiology. In this chapter, we discuss the current state of play for research into DNA modifications in AD, the most well studied being 5-methylcytosine (5-mC). We describe the earlier studies of candidate genes and global measures of DNA modifications in human AD samples, in addition to studies in mouse models of AD. We focus on recent epigenome-wide association studies (EWAS) in human AD, using microarray technology, examining a number of key study design issues pertinent to such studies. Finally, we discuss how new technological advances could further progress the research field.

  20. Slow gamma rhythms in CA3 are entrained by slow gamma activity in the dentate gyrus.

    Science.gov (United States)

    Hsiao, Yi-Tse; Zheng, Chenguang; Colgin, Laura Lee

    2016-12-01

    In hippocampal area CA1, slow (∼25-55 Hz) and fast (∼60-100 Hz) gamma rhythms are coupled with different CA1 afferents. CA1 slow gamma is coupled to inputs from CA3, and CA1 fast gamma is coupled to inputs from the medial entorhinal cortex (Colgin LL, Denninger T, Fyhn M, Hafting T, Bonnevie T, Jensen O, Moser MB, Moser EI. Nature 462: 353-357, 2009). CA3 gives rise to highly divergent associational projections, and it is possible that reverberating activity in these connections generates slow gamma rhythms in the hippocampus. However, hippocampal gamma is maximal upstream of CA3, in the dentate gyrus (DG) region (Bragin A, Jando G, Nadasdy Z, Hetke J, Wise K, Buzsaki G. J Neurosci 15: 47-60, 1995). Thus it is possible that slow gamma in CA3 is driven by inputs from DG, yet few studies have examined slow and fast gamma rhythms in DG recordings. Here we investigated slow and fast gamma rhythms in paired recordings from DG and CA3 in freely moving rats to determine whether slow and fast gamma rhythms in CA3 are entrained by DG. We found that slow gamma rhythms, as opposed to fast gamma rhythms, were particularly prominent in DG. We investigated directional causal influences between DG and CA3 by Granger causality analysis and found that DG slow gamma influences CA3 slow gamma. Moreover, DG place cell spikes were strongly phase-locked to CA3 slow gamma rhythms, suggesting that DG excitatory projections to CA3 may underlie this directional influence. These results indicate that slow gamma rhythms do not originate in CA3 but rather slow gamma activity upstream in DG entrains slow gamma rhythms in CA3. Copyright © 2016 the American Physiological Society.

  1. Realities of craniofacial growth modification.

    Science.gov (United States)

    Kluemper, G T; Spalding, P M

    2001-03-01

    Facial growth modification can be an effective method of resolving skeletal discrepancies. There still is much controversy regarding our understanding of the nature and extent of skeletal orthopedic change possible in individual patients and the most effective appliances and timing of such treatment. In the treatment of class II patients, growth modification can lead to an improvement, if not complete correction of the class II malocclusion. Although two-phase treatment with an early first prepubertal phase can be effective, a later single-phase approach during early puberty seems to be equally effective. Certainly, before surgical correction of the mild to moderate skeletal class II problem in a growing patient is considered, an orthopedic phase of treatment prior to the pubertal growth spurt is an appropriate first step. Skeletal class III patients with a maxillary deficiency stand to gain significant benefits from early orthopedic treatment. However, such therapy may produce more favorable changes for older children and adolescents than previously thought. Nevertheless, orthopedic correction of the mild to moderate skeletal class III should be accompanied by regular progress evaluations to avoid creating significant dental compensations in the face with little skeletal change that ultimately requires surgery anyway. Skeletal class III patients with mandibular excess and/or vertical excess are poor candidates for growth modification. Orthopedic palatal expansion appears to be effective and stable at any time prior to late puberty, a stage of development when ossification of the maxillary sutures is more advanced. Consequently, the timing for expansion may be better determined by the specific needs of each patient. A functional shift resulting from a crossbite is optimally corrected early, so that asymmetric growth of the mandible can be reduced or even prevented. Postpubertal orthopedic expansion is likely to result in bone bending, which will reverse itself over

  2. Germline modification of domestic animals.

    Science.gov (United States)

    Tang, L; González, R; Dobrinski, I

    2015-01-01

    Genetically-modified domestic animal models are of increasing significance in biomedical research and agriculture. As authentic ES cells derived from domestic animals are not yet available, the prevailing approaches for engineering genetic modifications in those animals are pronuclear microinjection and somatic cell nuclear transfer (SCNT, also known as cloning). Both pronuclear microinjection and SCNT are inefficient, costly, and time-consuming. In animals produced by pronuclear microinjection, the exogenous transgene is usually inserted randomly into the genome, which results in highly variable expression patterns and levels in different founders. Therefore, significant efforts are required to generate and screen multiple founders to obtain animals with optimal transgene expression. For SCNT, specific genetic modifications (both gain-of-function and loss-of-function) can be engineered and carefully selected in the somatic cell nucleus before nuclear transfer. SCNT has been used to generate a variety of genetically modified animals such as goats, pigs, sheep and cattle; however, animals resulting from SCNT frequently suffer from developmental abnormalities associated with incomplete nuclear reprogramming. Other strategies to generate genetically-modified animals rely on the use of the spermatozoon as a natural vector to introduce genetic material into the female gamete. This sperm mediated DNA transfer (SMGT) combined with intracytoplasmatic sperm injection (ICSI) has relatively high efficiency and allows the insertion of large DNA fragments, which, in turn, enhance proper gene expression. An approach currently being developed to complement SCNT for producing genetically modified animals is germ cell transplantation using genetically modified male germline stem cells (GSCs). This approach relies on the ability of GSCs that are genetically modified in vitro to colonize the recipient testis and produce donor derived sperm upon transplantation. As the genetic change

  3. Instrumentation for gamma-ray astronomy

    Science.gov (United States)

    Bertsch, David L.; Fichtel, Carl E.; Trombka, Jacob I.

    1988-01-01

    The current status of gamma-ray-telescope technology for ground, airborne, and space observations is surveyed and illustrated with drawings, diagrams, and graphs and tables of typical data. For the low- and medium-energy ranges, consideration is given to detectors and detector cooling systems, background-rejection methods, radiation damage, large-area detectors, gamma-ray imaging, data analysis, and the Compton-interaction region. Also discussed are the gamma-ray interaction process at high energies; multilevel automated spark-chamber gamma-ray telescopes; the Soviet Gamma-1 telescope; the EGRET instrument for the NASA Gamma-Ray Observatory; and Cerenkov, air-shower, and particle-detector instruments for the TeV and PeV ranges. Significant improvements in resolution and sensitivity are predicted for the near future.

  4. The topological filtration of $\\gamma$-structures

    CERN Document Server

    Li, Thomas J X

    2012-01-01

    In this paper we study $\\gamma$-structures filtered by topological genus. $\\gamma$-structures are a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal to $\\gamma$, where composition means concatenation and nesting of such blocks. Our main results are the derivation of a new bivariate generating function for $\\gamma$-structures via symbolic methods, the singularity analysis of the solutions and a central limit theorem for the distribution of topological genus in $\\gamma$-structures of given length. In our derivation specific bivariate polynomials play a central role. Their coefficients count particular motifs of fixed topological genus and they are of relevance in the context of genus recursion and novel folding algorithms.

  5. Gravitational microlensing of gamma-ray blazars

    DEFF Research Database (Denmark)

    F. Torres, Diego; E. Romero, Gustavo; F. Eiroa, Ernesto

    2003-01-01

    We present a detailed study of the effects of gravitational microlensing on compact and distant $\\gamma$-ray blazars. These objects have $\\gamma$-ray emitting regions which are small enough as to be affected by microlensing effects produced by stars lying in intermediate galaxies. We analyze...... the temporal evolution of the gamma-ray magnification for sources moving in a caustic pattern field, where the combined effects of thousands of stars are taken into account using a numerical technique. We propose that some of the unidentified $\\gamma$-ray sources (particularly some of those lying at high...... galactic latitude whose gamma-ray statistical properties are very similar to detected $\\gamma$-ray blazars) are indeed the result of gravitational lensing magnification of background undetected Active Galactic Nuclei (AGNs)....

  6. Improved enzymatic hydrolysis of wheat straw by combined use of gamma ray and dilute acid for bioethanol production

    Science.gov (United States)

    Hyun Hong, Sung; Taek Lee, Jae; Lee, Sungbeom; Gon Wi, Seung; Ju Cho, Eun; Singh, Sudhir; Sik Lee, Seung; Yeoup Chung, Byung

    2014-01-01

    Pretreating wheat straw with a combination of dilute acid and gamma irradiation was performed in an attempt to enhance the enzymatic hydrolysis for bioethanol production. The glucose yield was significantly affected by combined pretreatment (3% sulfuric acid-gamma irradiation), compared with untreated wheat straw and individual pretreatment. The increasing enzymatic hydrolysis after combined pretreatment is resulting from decrease in crystallinity of cellulose, loss of hemicelluloses, and removal or modification of lignin. Therefore, combined pretreatment is one of the most effective methods for enhancing the enzymatic hydrolysis of wheat straw biomass.

  7. Gamma Imaging using Rotational Modulation Collimation

    Science.gov (United States)

    2014-01-01

    in detection probabilities over traditional gamma detection, especially when the radiation source was shielded . Within DSTO the gamma imaging program...container Figure A2: Experimental setup used to measure radiation source stored in its lead and steel shielding transport container 16 UNCLASSIFIED...characterise the performance of two rotating modulation collimator (RMC) gamma imagers built by DSTO. The ability of these devices to image shielded and

  8. Constraining the CKM angle $\\gamma$ at LHCb

    CERN Document Server

    Vallier, Alexis

    2015-01-01

    A selection of latest LHCb measurements related to the determination of the CKM angle $\\gamma$ is presented. Included are: the current combination of direct $\\gamma$ measurements, the first observation of the $B^0_s \\to D^{*±} K^±$ decay, the first observation and amplitude analysis of the $B^- \\to D^+ K^- \\pi^-$ decay and the constraint on $\\gamma$ from charmless B decays

  9. Gamma-Ray Astronomy Technology Needs

    Science.gov (United States)

    Gehrels, N.; Cannizzo, J. K.

    2012-01-01

    In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

  10. Cross-Section of Hadron Production in $\\gamma\\gamma$ Collisions at LEP

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Button, A M; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hong, S J; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sassowsky, M; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1997-01-01

    The reaction $\\mathrm{e}^{+} \\mathrm{e}^{-} \\rightarrow \\mathrm{e}^{+} \\mathrm{e}^{-} \\gamma ^{*} \\gamma ^{*} \\rightarrow \\mathrm{e}^{+} \\mathrm{e}^{-} $ {\\sl hadrons} is analysed using data collected by the L3 detector during the LEP runs at $\\sqrt {s}$ = 130-140 GeV and $\\sqrt {s}$ = 161 GeV. The cross sections $\\sigma(\\mathrm{e}^{+} \\mathrm{e}^{-} \\rightarrow \\mathrm{e}^{+} \\mathrm{e}^{-} $ {\\sl hadrons}) and $\\sigma (\\gamma\\gamma \\rightarrow $ {\\sl hadrons}) are measured in the interval 5 $\\leq W_{\\gamma\\gamma} \\leq$ 75 GeV. The energy dependence of the $\\sigma (\\gamma\\gamma \\rightarrow $ {\\sl hadrons}) cross section is consistent with the universal Regge behaviour of total hadronic cross sections. %\\end{abstract}

  11. Multiple elliptic gamma functions associated to cones

    CERN Document Server

    Winding, Jacob

    2016-01-01

    We define generalizations of the multiple elliptic gamma functions and the multiple sine functions, associated to good rational cones. We explain how good cones are related to collections of $SL_r(\\mathbb{Z})$-elements and prove that the generalized multiple sine and multiple elliptic gamma functions enjoy infinite product representations and modular properties determined by the cone. This generalizes the modular properties of the elliptic gamma function studied by Felder and Varchenko, and the results about the usual multiple sine and elliptic gamma functions found by Narukawa.

  12. Roy-Steiner equations for gamma gamma -> pi pi

    CERN Document Server

    Hoferichter, Martin; Schat, Carlos

    2011-01-01

    Starting from hyperbolic dispersion relations, we derive a system of Roy--Steiner equations for pion Compton scattering that respects analyticity, unitarity, gauge invariance, and crossing symmetry. It thus maintains all symmetries of the underlying quantum field theory. To suppress the dependence of observables on high-energy input, we also consider once- and twice-subtracted versions of the equations, and identify the subtraction constants with dipole and quadrupole pion polarizabilities. Based on the assumption of Mandelstam analyticity, we determine the kinematic range in which the equations are valid. As an application, we consider the resolution of the $\\gamma\\gamma\\to\\pi\\pi$ partial waves by a Muskhelishvili--Omn\\`es representation with finite matching point. We find a sum rule for the isospin-two $S$-wave, which, together with chiral constraints, produces an improved prediction for the charged-pion quadrupole polarizability $(\\alpha_2-\\beta_2)^{\\pi^\\pm}=(15.3\\pm 3.7)\\cdot 10^{-4} {\\rm fm}^5$. We inves...

  13. $\\gamma\\gamma$ \\to $\\pi\\pi\\pi$ to one loop in chiral perturbation theory

    CERN Document Server

    Talavera, P; Bijnens, J; Bramon, A; Cornet, F

    1995-01-01

    The \\gamma\\gamma \\to \\pi^0 \\pi^0 \\pi^0 and \\gamma\\gamma \\to \\pi^+ \\pi^- \\pi^0 amplitudes are discussed in the general context of Chiral Perturbation Theory (ChPT) to O(p^6). Chiral loops are found to play a major role. This makes these processes a good test of ChPT, mainly in its anomalous sector. We correct earlier numerical results at tree level and determine the one-loop results as well.

  14. Search for the decay $K_{s} \\to \\pi^{0}\\gamma\\gamma$

    CERN Document Server

    Lai, A; Batley, J Richard; Bevan, A; Dosanjh, R S; Gershon, T J; Kalmus, George Ernest; Munday, D J; Olaiya, E; Parker, M A; White, T; Wotton, S A; Barr, Giles David; Bocquet, G; Ceccucci, Augusto; Çuhadar-Dönszelmann, T; Cundy, Donald C; Doble, Niels T; Falaleev, V P; Gatignon, L; Gonidec, A; Gorini, B; Govi, G; Grafström, P; Kubischta, Werner; Lacourt, A; Lenti, M; Norton, Alan Robert; Palestini, S; Panzer-Steindel, B; Tatishvili, G T; Taureg, Hans; Velasco, M; Wahl, H; Cheshkov, C; Khristov, P Z; Kekelidze, V D; Madigozhin, D T; Molokanova, N A; Potrebenikov, Yu K; Tkachev, A L; Zinchenko, A I; Knowles, I; Lazzeroni, C; Martin, V; Sacco, R; Walker, A; Contalbrigo, M; Dalpiaz, Pietro; Duclos, J; Frabetti, P L; Gianoli, A; Martini, M; Masetti, L; Petrucci, F; Savrié, M; Bizzeti, A; Calvetti, M; Collazuol, G; Graziani, G; Iacopini, E; Becker, H G; Eppard, M; Fox, H; Holtz, K; Kalter, A; Kleinknecht, K; Koch, U; Köpke, L; Lopes da Silva, P; Marouelli, P; Pellmann, I A; Peters, A; Renk, B; Schmidt, S A; Schönharting, V; Schué, Yu; Wanke, R; Winhart, A; Wittgen, M; Chollet, J C; Fayard, Louis; Iconomidou-Fayard, L; Ocariz, J; Unal, G; Wingerter-Seez, I; Anzivino, Giuseppina; Cenci, P; Imbergamo, E; Lubrano, P; Mestvirishvili, A; Nappi, A; Pepé, M; Piccini, M; Carosi, R; Casali, R; Cerri, C; Cirilli, M; Costantini, F; Fantechi, R; Giudici, Sergio; Mannelli, I; Pierazzini, G M; Sozzi, M; Chèze, J B; Cogan, J; De Beer, M; Debu, P; Formica, A; Granier de Cassagnac, R; Mazzucato, E; Peyaud, B; Turlay, René; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Arcidiacono, R; Biino, C; Cartiglia, N; Guida, R; Marchetto, F; Menichetti, E; Pastrone, N; Nassalski, J P; Rondio, Ewa; Szleper, M; Wislicki, W; Wronka, S; Dibon, Heinz; Fischer, G; Jeitler, Manfred; Markytan, Manfred; Mikulec, I; Neuhofer, Günther; Pernicka, Manfred; Taurok, Anton; Widhalm, L

    2003-01-01

    A search for the decay $K_S\\to\\pi^0\\gamma\\gamma$ has been made using the NA48 detector at the CERN SPS. Using data collected in 1999 during a 40-hour run with a high-intensity $K_S$ beam, an upper limit for the branching ratio $BR(K_S\\to\\pi^0\\gamma\\gamma, z\\ge 0.2)<3.3\\times\

  15. Study of double-tagged $\\gamma\\gamma$ events at LEP2

    CERN Document Server

    Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, D; Barker, G; Baroncelli, A; Battaglia, M; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N; Benvenuti, A C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F; Chapkin, M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crawley, B; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J; Gandelman, M; García, C; Gavillet, P; Gazis, E; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, B P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Meyer, W T; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L; Murray, W; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, R; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Pukhaeva, N; Pullia, A; Rames, J; Ramler, L; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Rosenberg, E I; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sisakian, A; Smadja, G; Smirnova, O; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W; Verdier, P; Vertogradova, Yu L; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M

    2006-01-01

    Double-tagged interactions of photons with virtualities Q^2 between 10GeV^2 and 200GeV^2 are studied with the data collected by DELPHI at LEP2 from 1998 to 2000, corresponding to an integrated luminosity of 550pb^-1. The gamma*gamma* -> mu+mu- data agree with QED predictions. The cross-section of the reaction gamma*gamma* -> hadrons is measured and compared to the LO and NLO BFKL calculations.

  16. Performance Analysis of Decode-and-Forward Relaying in Gamma-Gamma Fading Channels

    CERN Document Server

    Bhatnagar, Manav R

    2012-01-01

    Decode-and-forward (DF) cooperative communication based on free space optical (FSO) links is studied in this letter. We analyze performance of the DF protocol in the FSO links following the Gamma-Gamma distribution. The cumulative distribution function (CDF) and probability density function (PDF) of a random variable containing mixture of the Gamma- Gamma and Gaussian random variables is derived. By using the derived CDF and PDF, average bit error rate of the DF relaying is obtained.

  17. High Redshift Gamma Ray Bursts

    Science.gov (United States)

    Gehrels, Neil

    2012-01-01

    The Swift Observatory has been detecting 100 gamma-ray bursts per year for 7 years and has greatly stimulated the field with new findings. Observations are made of the X-ray and optical afterglow from 1 minute after the burst, continuing for days. GRBs are providing a new tool to study the high redshift universe. Swift has detected several events at z>5 and one at z=9.4 giving information on metallicity, star formation rate and reionization. The talk will present the latest results.

  18. Gamma ray observatory productivity showcase

    Science.gov (United States)

    Davis, R. L.; Molgaard, D. A.

    1985-01-01

    The Gamma Ray Observatory (GRO) Program has been proclaimed to be the showcase productivity program for NASA and TRW. Among the multiple disciplines of a large-scale program, there is opportunity and need for improved efficiency, effectiveness, and reduction in the cost of doing business. The efforts and tools that will or have been implemented to achieve this end are described. Since the GRO Program is mainly an engineering program with the build of one satellite, the primary emphasis is placed on improving the efficiency and quality of management and engineering.

  19. Surface Modification for Microreactor Fabrication

    Directory of Open Access Journals (Sweden)

    Wladyslaw Torbicz

    2006-04-01

    Full Text Available In this paper, methods of surface modification of different supports, i.e. glass andpolymeric beads for enzyme immobilisation are described. The developed method ofenzyme immobilisation is based on Schiff’s base formation between the amino groups onthe enzyme surface and the aldehyde groups on the chemically modified surface of thesupports. The surface of silicon modified by APTS and GOPS with immobilised enzymewas characterised by atomic force microscopy (AFM, time-of-flight secondary ion massspectroscopy (ToF-SIMS and infrared spectroscopy (FTIR. The supports withimmobilised enzyme (urease were also tested in combination with microreactors fabricatedin silicon and Perspex, operating in a flow-through system. For microreactors filled withurease immobilised on glass beads (Sigma and on polymeric beads (PAN, a very high andstable signal (pH change was obtained. The developed method of urease immobilisationcan be stated to be very effective.

  20. Soy protein modification: A review

    Directory of Open Access Journals (Sweden)

    Barać Miroljub B.

    2004-01-01

    Full Text Available Soy protein products such as flour, concentrates and isolates are used in food formulation because of their functionality, nutritional value and low cost. To obtain their optimal nutritive and functional properties as well as desirable flavor different treatments are used. Soybean proteins can be modified by physical, chemical and enzymatic treatments. Different thermal treatments are most commonly used, while the most appropriate way of modifying soy proteins from the standpoint of safety is their limited proteolysis. These treatments cause physical and chemical changes that affect their functional properties. This review discusses three principal methods used for modification of soy protein products, their effects on dominant soy protein properties and some biologically active compounds.

  1. Surface modification of cellulose nanocrystals

    Institute of Scientific and Technical Information of China (English)

    WANG Neng; DING Enyong; CHENG Rongshi

    2007-01-01

    In order to improve the dispersibility of cellulose nanocrystal(CNC) particles,three difierent grafted reactions of acetylation,hydroxyethylation and hydroxypropylation were introduced to modify the CNC surface.The main advantages of these methods were the simple and easily controlled reaction conditions,and the dispersibility of the resulting products was distinctly improved.The properties of the modified CNC were characterized by means of Fourier transform infrared spectroscopy(FT-IR),13 C nuclear magnetic resonance(NMR),transmission electron microscopy(TEM)and thermogravimetric analyses(TGA).The results indicated mat after desiccation,the modification products could be dispersed again in the proper solvents by ultrasonic treatments,and the diameter of their particles had no obvious changes.However,their thermal degradation behaviors were quite different.The initial decomposition temperature of the modified products via hydroxyethylation or hydroxypropylation was lower than that of modified products via acetylation.

  2. Test of compositeness in p anti p ->. gamma gamma. X processes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Canal, C.A.; Grifols, J.A.; Mendez, A. (Universidad Autonoma de Barcelona (Spain). Dept. de Fisica Teorica)

    1984-10-11

    If composite spin-zero states are introduced in order to explain the measured abundance of Z -> e/sup +/e/sup -/..gamma.. events, it is shown that these states should be observed in the two-photon energy spectrum of p anti p -> ..gamma gamma..X. The possible choices for the coupling constants involved are discussed.

  3. Four-fermion production at gamma gamma colliders: 1. Lowest-order predictions and anomalous couplings

    CERN Document Server

    Bredenstein, A; Roth, M

    2004-01-01

    We have constructed a Monte Carlo generator for lowest-order predictions for the processes gamma gamma -> 4f and gamma gamma -> 4f+gamma in the Standard Model and extensions thereof by an effective gamma gamma Higgs coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes gamma gamma -> 4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size of various contributions to cross sections, such as from weak charged- or neutral-current, or from strong interactions, is analyzed. Particular attention is paid to W-pair production channels gamma gamma -> W W -> 4f(+gamma) wher...

  4. Interferon gamma increases survival in urine experimental cryptococcosis El Interferon gamma incrementa la sobrevida de un modelo experimental murino de criptococosis

    Directory of Open Access Journals (Sweden)

    Amadeo J. Bava

    1995-10-01

    Full Text Available Systemic disease by Cryptococcus neoformans (C. neoformans is a common opportunistic infection in immunodeficient patients. Cellular immunity seems to be the most important determinant of resistance. The aim of this study was to assess the effect of recombinant rat interferon gamma (IFN-gamma in murine cryptococcosis (Balb/c mice infected by IP route with the Rivas strain of C. neoformans, evaluating survival time, macroscopic and microscopic examination of the organs, and massive seeding of brain homogenate. IFN-gamma treatment, at a daily dose of 10,000 IU, did not modify significantly these variables when mice were challenged with a high inoculum (10(7 yeasts and treatment was delayed to 5 days after infection (median survival 21 days in control mice vs. 23 days in IFN-treated. Another set of experiments suggested that IFN-gamma treatment, at a dose of 10,000 IU/day, begun at the moment of infection could be useful (it prolonged survival from 20 to 28 days, although the difference did not achieve statistical signification. When used simultaneously with infection by 3.5 x 10(5 yeasts, IFN-gamma at 10,000 IU/day for 15 days significantly prolonged survival of mice (p = 0.004. These results suggest that, depending on the experimental conditions, IFN-gamma can improve survival of mice infected with a lethal dose of C. neoformans.Se evaluó la efectividad del interferon-gamma (IFN-gamma recombinante de rata en un modelo experimental de criptococosis desarollado en ratones Balb/C inoculados por vía intraperitoneal con la cepa Rivas de Cryptococcus neoformans (C. neoformans. Se tuvieron en cuenta el tiempo de sobrevida de los animales, el aspecto macroscópico de los órganos en la autopsia, la presencia de levaduras capsuladas en los tejidos y la siembra masiva de un homogenato de cerebro. El tratamiento con IFN-gamma, en dosis diarias de 10.000 UI, no modificó estos parámetros cuando la dosis infectante fue de 10(7 levaduras y el tratamiento se

  5. Post-Translational Modifications of Desulfovibrio vulgaris Hildenborough Sulfate Reduction Pathway Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Gaucher, S.P.; Redding, A.M.; Mukhopadhyay, A.; Keasling, J.D.; Singh, A.K.

    2008-03-01

    Recent developments in shotgun proteomics have enabled high-throughput studies of a variety of microorganisms at a proteome level and provide experimental validation for predicted open reading frames in the corresponding genome. More importantly, advances in mass spectrometric data analysis now allow mining of large proteomics data sets for the presence of post-translational modifications(PTMs). Although PTMs are a critical aspectof cellular activity, such information eludes cell-wide studies conducted at the transcript level. Here, we analyze several mass spectrometric data sets acquired using two-dimensional liquid chromatography tandem mass spectrometry, 2D-LC/MS/MS, for the sulfate reducing bacterium, Desulfovibrio vulgaris Hildenborough. Our searches of the raw spectra led us to discover several post-translationally modified peptides in D. vulgaris. Of these, several peptides containing a lysine with a +42 Da modification were found reproducibly across all data sets. Both acetylation and trimethylation have the same nominal +42 Da mass, and are therefore candidates for this modification. Several spectra were identified having markers for trimethylation, while one is consistent with an acetylation. Surprisingly, these modified peptides predominantly mapped to proteins involved in sulfate respiration. Other highly expressed proteins in D. vulgaris, such as enzymes involved in electron transport and other central metabolic processes, did not contain this modification. Decoy database searches were used to control for random spectrum/sequence matches. Additional validation for these modifications was provided by alternate workflows, for example, two-dimensional gel electrophoresis followed by mass spectrometry analysis of the dissimilatory sulfite reductase gamma-subunit(DsrC) protein. MS data for DsrC in this alternate workflow also contained the +42 Da modification at the same loci. Furthermore, the DsrC homologue in another sulfate reducing bacterium

  6. Review of Rule Modification in Sport

    OpenAIRE

    Arias, Jose L.; Francisco M. Argudo; Alonso, Jose I.

    2011-01-01

    The goal of this qualitative review was to analyze the state of the bibliography about rule modification in sport. In the literature reviewed, there are few studies of rule modification and related aspects. Most studies omit mentioning the purpose of the modifications, but they do refer to the goals of their analysis (improving players' performance, attracting spectators and athletes, attending to commercial pressure, adapting the sport to children's needs and interests, preventing injuries)....

  7. Climate modification directed by control theory

    CERN Document Server

    Liang, Wang

    2008-01-01

    Climate modification measures to counteract global warming receive some more new attentions in these years. Most current researches only discuss the impact of these measures to climate, but how to design such a climate regulator is still unknown. This paper shows the control theory could give the systematic direction for climate modification. But the control analyzing also reveals that climate modifications should only be regarded as a last-ditch measure.

  8. Proteomic analysis of post-translational modifications

    DEFF Research Database (Denmark)

    Mann, Matthias; Jensen, Ole N

    2003-01-01

    Post-translational modifications modulate the activity of most eukaryote proteins. Analysis of these modifications presents formidable challenges but their determination generates indispensable insight into biological function. Strategies developed to characterize individual proteins are now...... mass spectrometric peptide sequencing and analysis technologies hold tremendous potential. Finally, stable isotope labeling strategies in combination with mass spectrometry have been applied successfully to study the dynamics of modifications....

  9. Chemical Modifications of Starch: Microwave Effect

    OpenAIRE

    Kamila Lewicka; Przemysław Siemion; Piotr Kurcok

    2015-01-01

    This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation ...

  10. Electron-gamma directional correlations; Correlations directionnelles electron-gamma

    Energy Technology Data Exchange (ETDEWEB)

    Gerholm, T.R. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-10-01

    The theory of the angular correlation between conversion electrons and gamma rays is briefly outlined. The experimental methods used for the study of the electron-gamma correlation are described. The effects of the formation of a hole and the hyperfine structure magnetic coupling dependent on time are then considered. The experimental results showed that the attenuations found for different metallic media plainly conform to a simple quadrupolar interaction mechanism. For a source surrounded by an insulator, however, the results show that a rapidly disappearing coupling occurs as a supplement to the quadrupolar interaction mechanism. This coupling attenuates the angular correlation by about 75% of the non-perturbed value. It was concluded that for an intermediate half life of the level of the order of the nanosecond, the attenuations produced by the secondary effects of the hole formation can not be completely neglected. The metallic media considered were Ag, Au, Al, and Ga. In the study of E2 conversion processes, the radical matrix elements governing the E2 conversion process in the 412-KeV transition of {sup 198}Hg were determined. The results exclude the presence of dynamic contributions within the limits of experimental error. The values b{sub 2} (E2) and {alpha}-k (E2) obtained indirectly from the experimentally determined b{sub 4} particle parameter are in complete agreement with the theoretical values obtained by applying the corrections due to the shielding effect and to the finite dimension of the nucleus and excluding the dynamic contributions. The value for the internal conversion coefficient was also in good agreement. Experimental results from the intensity ratios between the peak and the continuum, however, seem to show significant deviations with respect to other experimental and theoretical values. There is good agreement between experimental and theoretical results on the internal conversion of {sup 203}Tl, {sup 201}Tl, and {sup 181}Ta. The theory

  11. Safety assessment of gamma-cyclodextrin.

    Science.gov (United States)

    Munro, I C; Newberne, P M; Young, V R; Bär, A

    2004-06-01

    Gamma-cyclodextrin (gamma-CD) is a cyclic alpha-(1,4)-linked oligosaccharide consisting of eight glucose molecules. Like other cyclodextrins, gamma-CD can form inclusion complexes with a variety of organic molecules because the inner side of the torus-like molecule is less polar than the outer side. In foods, gamma-CD may be used as a carrier for flavors, vitamins, polyunsaturated fatty acids, and other ingredients. It also has useful properties as a stabilizer in different food systems. The daily intake from all its intended uses in food at highest feasible concentrations has been estimated at 4.1g/person/day for consumers of gamma-CD containing foods. The present review summarizes the safety data of gamma-CD. The toxicity studies consist of standard genotoxicity tests, subchronic rat studies with oral and intravenous administration of gamma-CD for up to 3 months, a subchronic (3-month) toxicity study in dogs, a (1-year) oral toxicity study in rats, and embryotoxicity/teratogenicity studies in rats and rabbits. In the studies with oral administration, gamma-CD was given at dietary concentrations of up to 20%. All these studies demonstrated that gamma-CD is well tolerated and elicits no toxicological effects. Metabolic studies in rats showed that gamma-CD is rapidly and essentially completely digested by salivary and pancreatic amylase. Therefore, the metabolism of gamma-CD closely resembles that of starch and linear dextrins. A human study with ingestion of single doses of 8 g gamma-CD or 8 g maltodextrin did not reveal a difference in gastrointestinal tolerance of these two products. An interaction of ingested gamma-CD with the absorption of fat-soluble vitamins or other lipophilic nutrients is not to be expected because the formation of inclusion complexes is a reversible process, gamma-CD is readily digested in the small intestine, and studies with beta-CD, a non-digestible cyclodextrin, have shown that the bioavailability of vitamins (A, D, and E) is not

  12. Magnetars and Gamma Ray Bursts

    CERN Document Server

    Bucciantini, N

    2012-01-01

    In the last few years, evidences for a long-lived and sustained engine in Gamma Ray Bursts (GRBs) have increased the attention to the so called millisecond-magnetar model, as a competitive alternative to the standard collapsar scenario. I will review here the key aspects of the {\\it millisecond magnetar} model for Long Duration Gamma Ray Bursts (LGRBs). I will briefly describe what constraints, present observations put on any engine model, both in term of energetic, outflow properties, and the relation with the associated Supernova (SN). For each of these I will show how the millisecond magnetar model satisfies the requirements, what are the limits of the model, how can it be further tested, and what observations might be used to discriminate against it. I will also discuss numerical results that show the importance of the confinement by the progenitor star in explaining the formation of a collimated outflow, how a detailed model for the evolution of the central engine can be built, and show that a wide varie...

  13. Gemstone dedicated gamma irradiation development

    Energy Technology Data Exchange (ETDEWEB)

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  14. Food irradiation: Gamma processing facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

    1997-12-31

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  15. Gamma-ray burst models.

    Science.gov (United States)

    King, Andrew

    2007-05-15

    I consider various possibilities for making gamma-ray bursts, particularly from close binaries. In addition to the much-studied neutron star+neutron star and black hole+neutron star cases usually considered good candidates for short-duration bursts, there are also other possibilities. In particular, neutron star+massive white dwarf has several desirable features. These systems are likely to produce long-duration gamma-ray bursts (GRBs), in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions and could have any type of host galaxy. Thus, a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that this type of GRB may be quite common, in agreement with the fact that the absence of a supernova can only be established in nearby bursts.

  16. Epigenetic Modifications and Plant Hormone Action.

    Science.gov (United States)

    Yamamuro, Chizuko; Zhu, Jian-Kang; Yang, Zhenbiao

    2016-01-04

    The action of phytohormones in plants requires the spatiotemporal regulation of their accumulation and responses at various levels. Recent studies reveal an emerging relationship between the function of phytohormones and epigenetic modifications. In particular, evidence suggests that auxin biosynthesis, transport, and signal transduction is modulated by microRNAs and epigenetic factors such as histone modification, chromatin remodeling, and DNA methylation. Furthermore, some phytohormones have been shown to affect epigenetic modifications. These findings are shedding light on the mode of action of phytohormones and are opening up a new avenue of research on phytohormones as well as on the mechanisms regulating epigenetic modifications.

  17. Methodological guidelines for developing accident modification functions

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use...... limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. © 2015 Elsevier Ltd. All rights...

  18. Chemical biology approaches for studying posttranslational modifications.

    Science.gov (United States)

    Yang, Aerin; Cho, Kyukwang; Park, Hee-Sung

    2017-09-13

    Posttranslational modification (PTM) is a key mechanism for regulating diverse protein functions, and thus critically affects many essential biological processes. Critical for systematic study of the effects of PTMs is the ability to obtain recombinant proteins with defined and homogenous modifications. To this end, various synthetic and chemical biology approaches, including genetic code expansion and protein chemical modification methods, have been developed. These methods have proven effective for generating site-specific authentic modifications or structural mimics, and have demonstrated their value for in vitro and in vivo functional studies of diverse PTMs. This review will discuss recent advances in chemical biology strategies and their application to various PTM studies.

  19. Chemical Modifications of Starch: Microwave Effect

    Directory of Open Access Journals (Sweden)

    Kamila Lewicka

    2015-01-01

    Full Text Available This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation are discussed. Properties of microwave radiation and its impact on starch (with particular regard to modifications described in literature are characterized.

  20. Effect of gamma irradiation on the optical properties of UHMWPE (Ultra-high-molecular-weight-polyethylene) polymer

    Energy Technology Data Exchange (ETDEWEB)

    Raghuvanshi, S.K., E-mail: sraghu06@gmail.com [Department of Physics, Faculty of Natural Science, Jamia Millia Islamia, New Delhi 110025 (India); Ahmad, Bashir; Siddhartha [Department of Physics, Faculty of Natural Science, Jamia Millia Islamia, New Delhi 110025 (India); Srivastava, A.K. [Department of Applied Science, Sharda University, Plot No. 32-34, Knowledge Park-III, Greater Noida, Uttar Pradesh 201306 (India); Krishna, J.B.M. [UGC-DAEF Consortium for Scientific Research, Kolkata Center, III/LB-8 Bidhannagar, Kolkata 700098 (India); Wahab, M.A. [Department of Physics, Faculty of Natural Science, Jamia Millia Islamia, New Delhi 110025 (India)

    2012-01-15

    The UV-Visible absorption spectra of virgin and high dose gamma irradiated (up to 2000 kGy) UHMWPE polymer have been studied by using UV-Visible spectrophotometer (JASCO, V-570). The existence of the peaks, their shifting and broadening as a result of gamma irradiation has been observed. In the present work the Urbach energy is calculated by using Urbach edge method. Also the direct and indirect energy band gap in virgin and gamma irradiated UHMWPE polymer has been calculated. The values of indirect energy band gap have been found to be lower than the corresponding values of direct energy band gap. A decrease in the optical energy band gap with increasing gamma irradiation has been discussed on the basis of gamma-irradiation-induced modification in the UHMWPE polymer. The correlation between optical energy band gap and the number of carbon atoms in a cluster with modified Tauc's equation has been discussed in this polymer. We have also observed the color formation which became more and more prominent with increasing dose and at the highest dose the fully transparent sample became completely opaque. Looking at the trend of the absorption curve this polymer can be used as a very good dosimeter for the gamma ray irradiation.

  1. Covariant tensor formalism for partial wave analyses of $\\psi$ decays into $\\gamma\\gamma V$

    OpenAIRE

    Dulat, Sayipjamal; Zou, Bing-Song; Wu, Ji-Min

    2004-01-01

    The double radiative decays $\\psi\\to\\gamma\\gamma V$ with $V\\equiv \\rho,\\omega,\\phi$ have a potential to provide information on the flavor content of any meson resonances (R) with positive charge parity ($C=+$) and mass above 1 GeV through $\\psi\\to\\gamma R \\to\\gamma\\gamma V$. To get the information, one needs both high statistic data and partial wave analysis (PWA). While high statistic data will be available soon at CLEO-c and BES-III, here we provide theoretical PWA formulae for these $\\psi$...

  2. Measurement of the radiative decay width \\Gamma[\\Lambda(1520) --> \\Lambda \\gamma] with the SPHINX spectrometer

    CERN Document Server

    Antipov, Y M; Batarin, V A; Vavilov, D V; Victorov, V A; Eroshin, O V; Golovkin, S V; Gorin, Yu P; Kolganov, V Z; Kozhevnikov, A P; Konstantinov, A S; Kubarovskii, V P; Kurshetsov, V F; Landsberg, L G; Leontiev, V M; Lomkatsi, G S; Molchanov, V V; Mukhin, V A; Nilov, A F; Patalakha, D I; Petrenko, S V; Smolyankin, V T; Antipov, Yu.M.; Gorin, Yu.P.

    2004-01-01

    The radiative decay \\Lambda(1520) --> \\Lambda \\gamma was measured directly in the study of exclusive diffractive-like reaction p + N --> \\Lambda(1520) K^+ + N, \\Lambda(1520) --> \\Lambda \\gamma with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR[\\Lambda(1520) --> \\Lambda \\gamma] = (1.02+/-0.21)x10^{-2} and \\Gamma[\\Lambda(1520) \\to \\Lambda \\gamma] = 159+/-35 keV (statistical uncertainty). The systematic uncertainty is estimated to be below 15%.

  3. Photon structure functions and azimuthal correlations of lepton pairs in tagged $\\gamma\\gamma$ collisions

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Easo, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, A; Ziegler, F; Zilizi, G

    1998-01-01

    Measurements of the QED structure of the photon based on the reaction ee to ee gamma /sup (*)/(P/sup 2/) gamma *(Q/sup 2/) to ee mu mu are discussed. This review is an update of the discussion of the results on the QED structure of the photon and covers the published measurements of the photon structure functions F/sub 2//sup gamma /, F/sub A//sup gamma / and F/sub B//sup gamma / and of the differential cross-section d sigma /dx for the exchange of two virtual photons. (10 refs).

  4. Gamma-hydroxybutyrate abuse and dependence

    NARCIS (Netherlands)

    Noorden, M.S. van; Kamal, R.M.; Dijkstra, B.A.G.; Brunt, T.M.; Jong, C.A.J. de

    2016-01-01

    Gamma-hydroxybutyrate (GHB) is a short-chain fatty acid that naturally occurs in the brain, where it acts as a neurotransmitter and as a neuromodulator. GHB is a gamma-aminobutyric acid (GABA) analogue that passes the blood–brain barrier. GHB exerts its actions by binding to the GHB receptor

  5. Shielding for beta-gamma radiation.

    Science.gov (United States)

    Fletcher, J J

    1993-06-01

    The build-up factor, B, for lead was expressed as a polynominal cubic function of the relaxation length, mu x, and incorporated in a "general beta-gamma shielding equation." A computer program was written to determine shielding thickness for polyenergetic beta-gamma sources without resorting to the conventional "add-one-HVL" method.

  6. Prompt gamma-ray activation analysis (PGAA)

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J. [Fribourg Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The paper deals with a brief description of the principles of prompt gamma-ray activation analysis (PGAA), with the detection of gamma-rays, the PGAA project at SINQ and with the expected performances. 8 figs., 3 tabs., 10 refs.

  7. Multiple Scatters in Single Site Gamma Backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, J. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-16

    nEXO aims to reduce its gamma backgrounds by taking advantage of the fact that a large number of gammas that would otherwise be backgrounds will undergo multiple compton scattering in the TPC and produce spatially distinct signals. These multi-sited (MS) events can be excluded from the 0νββ search.

  8. On the incomparability of Gamma and Linda

    NARCIS (Netherlands)

    G. Zavattaro

    1998-01-01

    htmlabstractWe compare Gamma and Linda, two of the most prominent coordination languages based on generative communication via a shared data space. In Gamma computation is obtained by applying multiset rewriting rules, reminiscent of the way chemical reactions happen in a solution. On the other

  9. On the incomparability of Gamma and Linda

    NARCIS (Netherlands)

    Zavattaro, G.

    1998-01-01

    We compare Gamma and Linda, two of the most prominent coordination languages based on generative communication via a shared data space. In Gamma computation is obtained by applying multiset rewriting rules, reminiscent of the way chemical reactions happen in a solution. On the other hand, Linda perm

  10. Gamma ray spectroscopy with PPM resolving power

    CERN Document Server

    Börner, H; Mutti, P

    2002-01-01

    Applications of gamma-ray spectroscopy with ppm resolving power are presented. The extraordinary resolution allows via the Gamma Ray Induced Doppler broadening (GRID) technique to determine lifetimes of excited nuclear levels. This has contributed to important nuclear structure information. We report on the current status of the technique

  11. Gamma-hydroxybutyrate abuse and dependence

    NARCIS (Netherlands)

    Noorden, M.S. van; Kamal, R.M.; Dijkstra, B.A.G.; Brunt, T.M.; Jong, C.A.J. de

    2016-01-01

    Gamma-hydroxybutyrate (GHB) is a short-chain fatty acid that naturally occurs in the brain, where it acts as a neurotransmitter and as a neuromodulator. GHB is a gamma-aminobutyric acid (GABA) analogue that passes the blood–brain barrier. GHB exerts its actions by binding to the GHB receptor in the

  12. Genetics Home Reference: mucolipidosis III gamma

    Science.gov (United States)

    ... inside lysosomes, including mucolipidosis III gamma , are called lysosomal storage disorders. The signs and symptoms of mucolipidosis III gamma are most likely due to the shortage of digestive enzymes inside lysosomes and the effects these enzymes have outside the cell. Learn more ...

  13. Airborne Gamma-Ray Survey RISØ 2004

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor.......The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor....

  14. Gamma ray astronomy from satellites and balloons

    Science.gov (United States)

    Schoenfelder, V.

    1986-01-01

    A survey is given of gamma ray astronomy topics presented at the Cosmic Ray Conference. The major conclusions at the Cosmic Ray Conference in the field of gamma ray astronomy are given. (1) MeV-emission of gamma-ray bursts is a common feature. Variations in duration and energy spectra from burst to burst may explain the discrepancy between the measured log N - log S dependence and the observed isotropy of bursts. (2) The gamma-ray line at 1.809 MeV from Al(26) is the first detected line from a radioactive nucleosynthesis product. In order to understand its origin it will be necessary to measure its longitude distribution in the Milky Way. (3) The indications of a gamma-ray excess found from the direction of Loop I is consistent with the picture that the bulk of cosmic rays below 100 GeV is produced in galactic supernova remnants. (4) The interpretation of the large scale distribution of gamma rays in the Milky Way is controversial. At present an extragalactic origin of the cosmic ray nuclei in the GeV-range cannot be excluded from the gamma ray data. (5) The detection of MeV-emission from Cen A is a promising step towards the interesting field of extragalactic gamma ray astronomy.

  15. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  16. Gamma-hydroxybutyrate abuse and dependence

    NARCIS (Netherlands)

    Noorden, M.S. van; Kamal, R.M.; Dijkstra, B.A.G.; Brunt, T.M.; Jong, C.A.J. de

    2016-01-01

    Gamma-hydroxybutyrate (GHB) is a short-chain fatty acid that naturally occurs in the brain, where it acts as a neurotransmitter and as a neuromodulator. GHB is a gamma-aminobutyric acid (GABA) analogue that passes the blood–brain barrier. GHB exerts its actions by binding to the GHB receptor in the

  17. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  18. Colliding. gamma. e and. gamma gamma. beams based in single-pass e/sup +/e/sup -/ accelerators. Pt. 2. Polarization effects, monochromatization improvement

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Panfil, S.L.; Telnov, V.I.

    Polarization effects are considered in colliding ..gamma..e and ..gamma gamma.. beams, which are proposed to be obtained on the basis of linear e/sup +/e/sup -/ colliders (by backward Compton scattering of laser light on electron beams). It is shown that using electrons and laser photons with helicities lambda and Psub(c), such that lambdaPsub(c) < 0, essentially improves the monochromatization. The characteristic laser flash energy, A/sub 0/, which is necessary to obtain a conversion coefficient k proportional 1 with a definite degree of monochromatization, is considerably less (somestimes by one order of magnitude) in the case 2 lambdaPsub(c) = -1 in contrast to the case lambdaPsub(c) = 0. Simultaneously the luminosities Lsub(..gamma..e) and Lsub(..gamma gamma..) essentially increase. Formulae are obtained which allow one to extract the polarization information about ..gamma..e -> X and ..gamma gamma.. -> X reactions. Perculiarities connected with the specific scheme of the ..gamma.. beam preparation are discussed. Problems of the calibration of the ..gamma..e and ..gamma gamma.. collisions for the polarized beams are discussed.

  19. HIGGS PHYSICS WITH A GAMMA GAMMA COLLIDER BASED ON CLIC 1*.

    Energy Technology Data Exchange (ETDEWEB)

    ASNER,D.; BURKHARDT,H.; DE ROECK,A.; ELLIS,J.; GRONBERG,J.; HEINEMEYER,S.; SCHMITT,M.; SCHULTE,D.; VELASCO,M.; ZIMMERMAN,F.

    2001-11-01

    We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy {gamma}{gamma} collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a {gamma}{gamma} total (peak) luminosity of 2.0 (0.36) x 10{sup 34} cm{sup -2} s{sup -1} with E{sub CM}({gamma}{gamma}) 115 GeV. We show how CLICHE could be used to measure accurately the mass, {bar b}b, WW and {gamma}{gamma} decays of a light Higgs boson. We illustrate how these measurements may distinguish between the Standard Model Higgs boson and those in supersymmetric and more general two-Higgs-doublet models, complementing the measurements to be made with other accelerators. We also comment on other prospects in {gamma}{gamma} and e{sup -}{gamma} physics with CLICHE.

  20. The GAMMA-400 gamma-ray telescope characteristics. Angular resolution and electrons/protons separation

    CERN Document Server

    Leonov, A A; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Boyarchuk, K A; Castellini, G; Cattaneo, P W; Cumani, P; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2014-01-01

    The measurements of gamma-ray fluxes and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV, which will be implemented by the specially designed GAMMA-400 gamma-ray telescope, concern with the following broad range of science topics. Searching for signatures of dark matter, surveying the celestial sphere in order to study gamma-ray point and extended sources, measuring the energy spectra of Galactic and extragalactic diffuse gamma-ray emission, studying gamma-ray bursts and gamma-ray emission from the Sun, as well as high precision measuring spectra of high-energy electrons and positrons, protons and nuclei up to the knee. To clarify these scientific problems with the new experimental data the GAMMA-400 gamma-ray telescope possesses unique physical characteristics comparing with previous and present experiments. For gamma-ray energies more than 100 GeV GAMMA-400 provides the energy resolution of ~1% and angular resolution better than 0.02 deg. The methods developed to reconstru...

  1. HIGGS PHYSICS WITH A GAMMA GAMMA COLLIDER BASED ON CLIC 1*.

    Energy Technology Data Exchange (ETDEWEB)

    ASNER,D.; BURKHARDT,H.; DE ROECK,A.; ELLIS,J.; GRONBERG,J.; HEINEMEYER,S.; SCHMITT,M.; SCHULTE,D.; VELASCO,M.; ZIMMERMAN,F.

    2001-11-01

    We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy {gamma}{gamma} collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a {gamma}{gamma} total (peak) luminosity of 2.0 (0.36) x 10{sup 34} cm{sup -2} s{sup -1} with E{sub CM}({gamma}{gamma}) 115 GeV. We show how CLICHE could be used to measure accurately the mass, {bar b}b, WW and {gamma}{gamma} decays of a light Higgs boson. We illustrate how these measurements may distinguish between the Standard Model Higgs boson and those in supersymmetric and more general two-Higgs-doublet models, complementing the measurements to be made with other accelerators. We also comment on other prospects in {gamma}{gamma} and e{sup -}{gamma} physics with CLICHE.

  2. First observation of in-medium modifications of the omega meson

    CERN Document Server

    Trnka, D; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglasov, Yu A; Bogendorfer, R; Castelijns, R; Credé, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, C; Gothe, R W; Gregor, R; Gridnev, A B; Gutz, E; Hoffgen, S; Hoffmeister, P; Horn, I; Hossl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, F; Klempt, E; Konrad, M; Kopf, B; Kotulla, M; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; Van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, C; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Sule, A; Thoma, U; Varma, R; Walther, D; Weinheimer, C; Wendel, C; Powai, I I T

    2005-01-01

    The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction A(gamma, omega)X. Results obtained for Nb are compared to a reference measurement on a liquid hydrogen target. While for recoiling, long-lived mesons (pi, eta and etaprime), which decay outside of the nucleus, a difference in the lineshape for the two data samples is not observed, we find a significant enhancement towards lower masses for omega mesons with low momenta produced on the Nb target.

  3. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

    2006-03-15

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  4. The Space-Based Gamma-Ray Telescope GAMMA-400 and Its Scientific Goals

    CERN Document Server

    Galper, A M; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Avanesov, G A; Bergstrom, L; Bogomolov, E A; Boezio, M; Bonvicini, V; Boyarchuk, K A; Dogiel, V A; Gusakov, Yu V; Fradkin, M I; Fuglesang, Ch; Hnatyk, B I; Kachanov, V A; Kadilin, V V; Kaplin, V A; Kheymits, M D; Korepanov, V; Larsson, J; Leonov, A A; Longo, F; Maestro, P; Marrocchesi, P; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Runtso, M F; Ryde, F; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Topchiev, N P; Vacchi, A; Vannuccini, E; Vasiliev, G I; Yurkin, Yu T; Zampa, N; Zarikashvili, V N; Zverev, V G

    2013-01-01

    The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimized for the energy 100 GeV with the best parameters: the angular resolution ~0.01 deg, the energy resolution ~1%, and the proton rejection factor ~10E6, but is able to measure gamma-ray and electron + positron fluxes in the energy range from 100 MeV to 10 TeV. GAMMA-400 is aimed to a broad range of science topics, such as search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of cosmic-ray electrons + positrons, and nuclei.

  5. Study of $\\psi(2S)$ decays into $\\gamma K^+K^-$ and $\\gamma \\pi^+\\pi^-$

    CERN Document Server

    Ablikim, M; Bai, J Z; Ban, Y; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Chen, Jin; Chen, Y B; Chu, Y P; Dai, Y S; Diao, L Y; Deng, Z Y; Dong, Q F; Du, S X; Fang, J; Fang, S S; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; Guo, Z J; Harris, F A; LHe, K; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, J H; Hu, T; Huang, X T; Ji, X B; Jiang, X S; Jiang, X Y; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, G; Li, H B; Li, J; Li, R Y; Li, S M; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liao, H B; Liu, B J; Liu, C X; Liu, F; Liu, Fang; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, Jian; Liu, Q; Liu, R G; Liu, Z A; Lou, Y C; Lu, F; Lu, G R; Lu, J G; Lundborg, A; Luo, C L; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Mao, Z P; Mo, X H; Nie, J; Olsen, S L; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Ren, Z Y; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, C P; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tong, G L; Varner, G S; Wang, D Y; Wang, L; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Y F; Wang, Z; Wang, Z Y; Wang, Zheng; Wei, C L; Wei, D H; Weng, Y; Wiedner, U; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, Y X; Ye, M H; Ye, Y X; Yu, G W; Yuan, C Z; Yuan, Y; Zhang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, S H; Zhang, X Y; Zhang, Yiyun; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, W J; Zhao, M G; Zhao, P P; Zhao, W R; Zhao, Z G; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A; Zhuang, X A; Zou, B S

    2007-01-01

    Radiative charmonium decays from the BESII sample of 14$\\times10^{6}$ $\\psi(2S)$-events into two different final states, $\\gamma K^+K^-$ and $\\gamma\\pi^+\\pi^-$, are analyzed. Product branching fractions for $\\psi(2S)\\to\\gamma X\\to \\gamma\\pi^+\\pi^-$, $\\gamma K^+K^-$ are given, where $X=f_2(1270)$, $f_0(1500)$, and $f_0(1710)$ in $\\pi^+\\pi^-$ and $f_2(1270)$, $f_2'(1525)$, and $f_0(1700)$ in $K^+K^-$. An angular analysis gives the ratios of the helicity projections for the $f_2(1270)$ in $\\psi(2S)\\to\\gamma f_2(1270)\\to\\gamma\\pi^+\\pi^-$.

  6. Zapping Mars Rocks with Gamma Rays

    Science.gov (United States)

    Taylor, G. J.

    1999-12-01

    Because we do not know what deadly microorganisms might be lurking inside samples returned from Mars, the samples will either have to be sterilized before release or kept in isolation until biological studies declare them safe. One way to execute microorganisms is with radiation, such as gamma rays. Although quite effective in snuffing out bacteria and viruses, gamma rays might also affect the mineralogical, chemical, and isotopic compositions of the zapped rocks and soils. Carl Allen (Lockheed Martin Space Operations, Houston) and a team of 18 other analysts tested the effect of gamma rays on rock and mineral samples like those we expect on Mars. Except for some darkening of some minerals, high doses of gamma rays had no significant effect on the rocks, making gamma radiation a feasible option for sterilizing samples returned from Mars.

  7. GEANT simulation of the $\\gamma$ nuclear gauge

    CERN Document Server

    Ouardi, A; Benchekroun, D; Hoummada, A

    2003-01-01

    The gamma nuclear gauging technique used for monitoring the sediment load suspended in water, is based on the detection of gamma rays emitted by a radioactive source. The GEANT321 Monte Carlo simulation tool, originally developed at CERN for high energy physics experiments, is used for the evaluation and calibration of gamma nuclear gauges. A set of parameters, principally the source energy, the source-detector separation, the lead block thickness and the energy threshold below which the sediments elemental composition affects the measurement or the energy corresponding to the Compton and photoelectric windows separation, are discussed and evaluated in the case of the gamma scattering gauge. For the gamma transmission gauge, the GEANT321 code has been used to define the optimal source detector distance interval, particularly for the Moroccan sediment samplers, and to check the influence of the radionuclide existing in the suspension, on the gauge response accuracy. Experimental calibration was also carried ou...

  8. Thermal neutron capture gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Tuli, J.K.

    1983-01-01

    The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.

  9. Transitional $\\gamma$ strength in Cd isotopes

    CERN Document Server

    Larsen, A C; Bürger, A; Goriely, S; Guttormsen, M; Görgen, A; Hagen, T W; Harissopulos, S; Nyhus, H T; Renstrøm, T; Schiller, A; Siem, S; Tveten, G M; Voinov, A V; Wiedeking, M

    2013-01-01

    The level densities and $\\gamma$-ray strength functions of $^{105,106,111,112}$Cd have been extracted from particle-$\\gamma$ coincidence data using the Oslo method. The level densities are in very good agreement with known levels at low excitation energy. The $\\gamma$-ray strength functions display no strong enhancement for low $\\gamma$ energies. However, more low-energy strength is apparent for $^{105,106}$Cd than for $^{111,112}$Cd. For $\\gamma$ energies above $\\approx$ 4 MeV, there is evidence for some extra strength, similar to what has been previously observed for the Sn isotopes. The origin of this extra strength is unclear; it might be due to $E1$ and $M1$ transitions originating from neutron skin oscillations or the spin-flip resonance, respectively.

  10. Gamma-ray pulsars: a gold mine

    CERN Document Server

    Grenier, Isabelle A

    2015-01-01

    The most energetic neutron stars, powered by their rotation, are capable of producing pulsed radiation from the radio up to gamma rays with nearly TeV energies. These pulsars are part of the universe of energetic and powerful particle accelerators, using their uniquely fast rotation and formidable magnetic fields to accelerate particles to ultra-relativistic speed. The extreme properties of these stars provide an excellent testing ground, beyond Earth experience, for nuclear, gravitational, and quantum-electrodynamical physics. A wealth of gamma-ray pulsars has recently been discovered with the Fermi Gamma-Ray Space Telescope. The energetic gamma rays enable us to probe the magnetospheres of neutron stars and particle acceleration in this exotic environment. We review the latest developments in this field, beginning with a brief overview of the properties and mysteries of rotation-powered pulsars, and then discussing gamma-ray observations and magnetospheric models in more detail.

  11. PPAR-gamma in the Cardiovascular System.

    Science.gov (United States)

    Duan, Sheng Zhong; Ivashchenko, Christine Y; Usher, Michael G; Mortensen, Richard M

    2008-01-01

    Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), an essential transcriptional mediator of adipogenesis, lipid metabolism, insulin sensitivity, and glucose homeostasis, is increasingly recognized as a key player in inflammatory cells and in cardiovascular diseases (CVD) such as hypertension, cardiac hypertrophy, congestive heart failure, and atherosclerosis. PPAR-gamma agonists, the thiazolidinediones (TZDs), increase insulin sensitivity, lower blood glucose, decrease circulating free fatty acids and triglycerides, lower blood pressure, reduce inflammatory markers, and reduce atherosclerosis in insulin-resistant patients and animal models. Human genetic studies on PPAR-gamma have revealed that functional changes in this nuclear receptor are associated with CVD. Recent controversial clinical studies raise the question of deleterious action of PPAR-gamma agonists on the cardiovascular system. These complex interactions of metabolic responsive factors and cardiovascular disease promise to be important areas of focus for the future.

  12. Bioactive Surface Modification of Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Yasuhiko Abe

    2013-01-01

    Full Text Available The purpose of this study was to establish an acid-etching procedure for altering the Ca/P ratio of the nanostructured surface of hydroxyapatite (HAP by using surface chemical and morphological analyses (XPS, XRD, SEM, surface roughness, and wettability and to evaluate the in vitro response of osteoblast-like cells (MC3T3-E1 cells to the modified surfaces. This study utilized HAP and HAP treated with 10%, 20%, 30%, 40%, 50%, or 60% phosphoric acid solution for 10 minutes at 25°C, followed by rinsing 3 times with ultrapure water. The 30% phosphoric acid etching process that provided a Ca/P ratio of 1.50, without destruction of the grain boundary of HAP, was selected as a surface-modification procedure. Additionally, HAP treated by the 30% phosphoric acid etching process was stored under dry conditions at 25°C for 12 hours, and the Ca/P ratio approximated to 1.00 accidentally. The initial adhesion, proliferation, and differentiation (alkaline phosphatase (ALP activity and relative mRNA level for ALP of MC3T3-E1 cells on the modified surfaces were significantly promoted (P<0.05 and 0.01. These findings show that the 30% phosphoric acid etching process for the nanostructured HAP surface can alter the Ca/P ratio effectively and may accelerate the initial adhesion, proliferation, and differentiation of MC3T3-E1 cells.

  13. Modifications of radiation detection response of PADC track detectors by photons

    CERN Document Server

    Sinha, D

    1998-01-01

    Photon induced modifications in polyalyldiglycol carbonate (PADC) track detectors have been studied in the dose range of 10 sup 1 -10 sup 6 Gy. It was found that some of the properties like bulk-etch rate, track-etch rate got enhanced at the dose of 10 sup 6 Gy. Activation energy for bulk-etching has been determined for different gamma doses. In order to correlate the high etch rate with the chemical modifications, UV-Vis, IR and ESR studies were carried out. These studies clearly give the indication that radiation damage results into radical formation through bond cleavage. TGA study was performed for understanding the thermal resistance of this detector. The results are presented and discussed.

  14. 38 CFR 36.4315 - Loan modifications.

    Science.gov (United States)

    2010-07-01

    ... back from the modification. (j) This section does not create a right of a borrower to have a loan... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Loan modifications. 36...) LOAN GUARANTY Guaranty or Insurance of Loans to Veterans With Electronic Reporting § 36.4315...

  15. Histone modifications: Cycling with chromosomal replication

    DEFF Research Database (Denmark)

    Thon, Genevieve

    2008-01-01

    Histone modifications tend to be lost during chromosome duplication. Several recent studies suggest that the RNA interference pathway becomes active during the weakened transcriptional repression occurring at centromeres in S phase, resulting in the re-establishment of histone modifications that ...

  16. Characterization of Surface Modification of Polyethersulfone Membrane

    Science.gov (United States)

    Surface modification of polyethersulfone (PES) membrane surface using UV/ozone-treated grafting and interfacial polymerization on membrane surface was investigated in order to improve the resistance of membrane surface to protein adsorption. These methods of surface modification were compared in te...

  17. Gamma Knife Radiosurgery for Acromegaly

    Directory of Open Access Journals (Sweden)

    John D. Rolston

    2012-01-01

    Full Text Available Acromegaly is debilitating disease occasionally refractory to surgical and medical treatment. Stereotactic radiosurgery, and in particular Gamma Knife surgery (GKS, has proven to be an effective noninvasive adjunct to traditional treatments, leading to disease remission in a substantial proportion of patients. Such remission holds the promise of eliminating the need for expensive medications, along with side effects, as well as sparing patients the damaging sequelae of uncontrolled acromegaly. Numerous studies of radiosurgical treatments for acromegaly have been carried out. These illustrate an overall remission rate over 40%. Morbidity from radiosurgery is infrequent but can include cranial nerve palsies and hypopituitarism. Overall, stereotactic radiosurgery is a promising therapy for patients with acromegaly and deserves further study to refine its role in the treatment of affected patients.

  18. Study of rice. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lien, J.J.; Chau, R.S.; Chen, S.C.; Chu, S.L.; Fu, Y.K.; Fang, C.K.; Fu, Y.H.

    1981-03-01

    The purpose of this experiment was to investigate whether the /sup 60/Co gamma-irradiated milled rice packed in economic and practical sealed bags could be preserved in common granaries in Taiwan for more than one year rather than slightly over one month without quality deterioration. As a result of this experiment we found that during the preservation of over a period of 18 months, the contents, such as moisture, ash, protein and fiber, of Tainan-5 Bon-Lai (Japonica Type) rice irradiated with 20 and 40 krad doses were quite stable, whereas reducing sugar showed slight fluctuations but did not vary significantly either. The fat, vitamin B/sub 1/ and niacin contents were found being reduced, while the increase in fatty acid content was an inevitable phenomenon along with the proceeding of the preservation.

  19. Origin of $\\gamma$ Ray Bursters

    CERN Document Server

    Mészáros, P

    1999-01-01

    The successful discovery of X-ray, optical and radio afterglows of GRB hasmade possible the identification of host galaxies at cosmological distances.The energy release inferred in these outbursts place them among the mostenergetic and violent events in the Universe. They are thought to be theoutcome of a cataclysmic stellar collapse or compact stellar merger, leading toa relativistically expanding fireball, in which particles are accelerated atshocks and produce nonthermal radiation. The substantial agreement betweenobservations and the theoretical predictions of the fireball shock modelprovide confirmation of the basic aspects of this scenario. Among recent issuesare the collimation of the outflow and its implications for the energetics, theproduction of prompt bright flashes at wavelenghts much longer than gamma-rays,the time structure of the afterglow, its dependence on the central engine orprogenitor system behavior, and the role of the environment on the afterglow.

  20. The IRMA gamma irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Berger, L.; Raboin, M.; Corbiere, J. [IRSN, Fontenat-aux-roses (France)

    2011-07-01

    The IRMA cobalt-60 irradiation cell has been installed at the Saclay research centre (25 km from Paris) for 40 years. IRMA is a facility with a maximum authorized capacity of 1, 700 TBq (i.e. approx. 46, 000 Ci). It is a test facility intended primarily for research and development studies on how equipment and materials respond to dose or dose rate exposure. Cobalt-60 gamma photons are the reference in this field. Irradiation is panoramic and achieved using 4, independent, cylindrical sealed sources (11 mm in diameter and 452 mm in length). When not in use, the sources are stored in a lead cask with 0.30 m thick walls to allow safe access inside the cell (uncontaminated environment). With an internal volume of 24 m{sup 3}, it can accommodate a very wide variety of geometric configurations for exposure to gamma radiation. Available dose rates range from 5 {mu}Gy/h (which is the background radiation in the cell when the sources are enclosed in their lead cask) to 25 kGy/h (value obtained 10 cm from a source holder containing all four sources). The resulting doses can be used in experiments representing relatively extreme situations (reactor accidents, dose after x years for equipment in hot cells, reprocessing plants, and so on).The IRMA facility has performed several irradiation tests on new components for EPR and LWR. The IRMA facility is also adapted to check the performance of new biological shieldings and protections for reactors and reprocessing plants. In several other fields of nuclear applications, this facility is useful to characterize and calibrate radiation detectors for the nuclear, space, and military industries

  1. Durability Assessment of Gamma Tial

    Science.gov (United States)

    Draper, Susan L.; Lerch, Bradley A.; Pereira, J. Michael; Miyoshi, Kazuhisa; Arya, Vinod K.; Zhuang, Wyman

    2004-01-01

    Gamma TiAl was evaluated as a candidate alloy for low-pressure turbine blades in aeroengines. The durability of g-TiAl was studied by examining the effects of impact or fretting on its fatigue strength. Cast-to-size Ti-48Al-2Cr-2Nb was studied in impact testing with different size projectiles at various impact energies as the reference alloy and subsequently fatigue tested. Impacting degraded the residual fatigue life. However, under the ballistic impact conditions studied, it was concluded that the impacts expected in an aeroengine would not result in catastrophic damage, nor would the damage be severe enough to result in a fatigue failure under the anticipated design loads. In addition, other gamma alloys were investigated including another cast-to-size alloy, several cast and machined specimens, and a forged alloy. Within this Ti-48-2-2 family of alloys aluminum content was also varied. The cracking patterns as a result of impacting were documented and correlated with impact variables. The cracking type and severity was reasonably predicted using finite element models. Mean stress affects were also studied on impact-damaged fatigue samples. The fatigue strength was accurately predicted based on the flaw size using a threshold-based, fracture mechanics approach. To study the effects of wear due to potential applications in a blade-disk dovetail arrangement, the machined Ti-47-2-2 alloy was fretted against In-718 using pin-on-disk experiments. Wear mechanisms were documented and compared to those of Ti-6Al-4V. A few fatigue samples were also fretted and subsequently fatigue tested. It was found that under the conditions studied, the fretting was not severe enough to affect the fatigue strength of g-TiAl.

  2. Electrochemical modification process of anodic alumina membrane

    Institute of Scientific and Technical Information of China (English)

    YU Mei; LIU Jian-hua; LI Song-mei

    2006-01-01

    The modification procedure of anodic alumina membrane(AAM) was studied. The AAM structure after modification was characterized by nickel nanowires prepared in AAM. Scanning electron microscopy was used to characterize the topography and structure properties of the AAM and nickel nanowires. The transformation of the current during the voltage reduction was studied. The mechanism of current and structure change during modification was discussed. The results show that a root structure produces after the AAM modification. The length of the root structure depends on the velocity of the voltage reduction. Slow voltage reduction leads to a large length of the root structure,otherwise,a short length of the root structure. At the end of the modification,the barrier layer is thin enough to be passed by electrons. Hence,the direct electrodeposition of one-dimensional nanowires can be carried out on the AAM with barrier layer and aluminum matrix successfully without any other treatments.

  3. Modification Semantics in Now-Relative Databases

    DEFF Research Database (Denmark)

    Torp, Kristian; Jensen, Christian Søndergaard; Snodgrass, R. T.

    2004-01-01

    Most real-world databases record time-varying information. In such databases, the notion of ??the current time,?? or NOW, occurs naturally and prominently. For example, when capturing the past states of a relation using begin and end time columns, tuples that are part of the current state have some...... past time as their begin time and NOW as their end time. While the semantics of such variable databases has been described in detail and is well understood, the modification of variable databases remains unexplored. This paper defines the semantics of modifications involving the variable NOW. More...... specifically,  the problems with modifications in the presence of NOW are explored, illustrating that the main problems are with modifications of tuples that reach into the future. The paper defines the semantics of modifications?including insertions, deletions, and updates?of databases without NOW, with NOW...

  4. Study of the effect of gamma irradiation on a commercial polycyclooctene I. Thermal and mechanical properties

    Science.gov (United States)

    García-Huete, N.; Laza, J. M.; Cuevas, J. M.; Vilas, J. L.; Bilbao, E.; León, L. M.

    2014-09-01

    A gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical, chemical and mechanical properties. Gamma irradiation originates free radicals able to induce chain scission or recombination of radicals, which induces annihilation, branching or crosslinking processes. The aim of this work is to research the structural, thermal and mechanical changes induced on a commercial polycyclooctene (PCO) when it is irradiated with a gamma source of 60Co at different doses (25-200 kGy). After gamma irradiation, gel content was determined by Soxhlet extraction in cyclohexane. Furthermore, thermal properties were evaluated before and after Soxhlet extraction by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as mechanical properties were measured by Dynamic Mechanical Thermal Analysis (DMTA). The results showed the variations of the properties depending on the irradiation dose. Finally, a first approach to evaluate qualitatively the shape memory behaviour of all irradiated PCO samples was performed by a visually monitoring shape recovery process.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  6. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    Energy Technology Data Exchange (ETDEWEB)

    Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh��user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil' kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K��ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

    2014-08-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  7. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    CERN Document Server

    Nefkens, B M K; Aguar-Bartolomé, P; Annand, J R M; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Berghäuser, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; Käser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmüller, D; Witthauer., L

    2014-01-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  8. REVIEW OF RULE MODIFICATION IN SPORT

    Directory of Open Access Journals (Sweden)

    Jose L. Arias

    2011-03-01

    Full Text Available The goal of this qualitative review was to analyze the state of the bibliography about rule modification in sport. In the literature reviewed, there are few studies of rule modification and related aspects. Most studies omit mentioning the purpose of the modifications, but they do refer to the goals of their analysis (improving players' performance, attracting spectators and athletes, attending to commercial pressure, adapting the sport to children's needs and interests, preventing injuries. Eighty percent of the studies did not report the outcome of the previous modifications they analyzed. More than half of the studies (60% achieved the proposed goals. Nearly two-thirds (63.83% analyzed the effect of rule modification on game actions occurring during the game or through a test. Most of the studies (91.5% did not consult the participants. Three-fourths of the studies (74.46% examined the effect of rule modification without any knowledge of a previous analysis or without any previous analysis, and 74.47% studied rule modification related to internal logic. Modifications to be introduced in a sport should be analyzed through a reflective process before their final introduction. The following points should be considered: establishing goals, respecting the basic rules without modifying them, becoming familiar with players' and coaches' opinions, determining the effect of the modification on a wide spectrum of variables, elaborating useful proposals for the organizations that are responsible for competitions, using more than one type of data, modifying the internal logic and, preferably, the functional rules, and following some basic stages to consolidate rule modification.

  9. Search for the decays $J/\\psi\\to\\gamma \\rho \\phi$ and $J/\\psi\\to\\gamma \\rho \\omega$

    CERN Document Server

    Bai, J Z; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Chen, Jin; Chen, Y B; Chu, Y P; Dai, Y S; Diao, L Y; Deng, Z Y; Dong, Q F; Du, S X; Fang, J; Fang, S S; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; Guo, Z J; Harris, F A; He, K L; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, J H; Hu, T; Huang, G S; Huang, X T; Ji, X B; Jiang, X S; Jiang, X Y; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, G; Li, H B; Li, J; Li, R Y; Li, S M; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liao, H B; Liu, B J; Liu, C X; Liu, F; Fang Liu; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, Jian; Liu, Q; Liu, R G; Liu, Z A; Lou, Y C; Lu, F; Lu, G R; Lu, J G; Luo, C L; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Mao, Z P; Mo, X H; Nie, J; Olsen, S L; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Ren, Z Y; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, C P; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tong, G L; Varner, G S; Wang, D Y; Wang, L; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Y F; Wang, Z; Wang, Z Y; Wang, Zheng; Wei, C L; Wei, D H; Weng, Y; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, Y X; Ye, M H; Ye, Y X; Yu, G W; Yuan, C Z; Yuan, Y; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, S H; Zhang, X Y; Zhang, Yiyun; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, J W; Zhao, M G; Zhao, P P; Zhao, W R; Zhao, Z G; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A; Zhuang, X A; Zou, B S

    2007-01-01

    Using 58 million $J/\\psi$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the decays $J/\\psi\\to \\gamma\\phi\\rho$ and $J/\\psi\\to \\gamma\\omega\\rho$ are searched for, and upper limits on their branching fractions are reported at the 90% C. L. No clear structures are observed in the $\\gamma \\rho$, $\\gamma \\phi$, or $\\rho \\phi $ mass spectra for $J/\\psi\\to \\gamma\\phi\\rho$ nor in the $\\gamma \\rho$, $\\gamma \\omega$, or $\\rho \\omega$ mass spectra for $J/\\psi\\to \\gamma\\omega\\rho$.

  10. Modification of EEG power spectra and EEG connectivity in autobiographical memory: a sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Brunetti, Riccardo; Farina, Benedetto; Speranza, Anna Maria; Losurdo, Anna; Testani, Elisa; Contardi, Anna; Della Marca, Giacomo

    2014-08-01

    The aim of the present study was to explore the modifications of scalp EEG power spectra and EEG connectivity during the autobiographical memory test (AM-T) and during the retrieval of an autobiographical event (the high school final examination, Task 2). Seventeen healthy volunteers were enrolled (9 women and 8 men, mean age 23.4 ± 2.8 years, range 19-30). EEG was recorded at baseline and while performing the autobiographical memory (AM) tasks, by means of 19 surface electrodes and a nasopharyngeal electrode. EEG analysis was conducted by means of the standardized LOw Resolution Electric Tomography (sLORETA) software. Power spectra and lagged EEG coherence were compared between EEG acquired during the memory tasks and baseline recording. The frequency bands considered were as follows: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta1 (13-17.5 Hz); beta2 (18-30 Hz); gamma (30.5-60 Hz). During AM-T, we observed a significant delta power increase in left frontal and midline cortices (T = 3.554; p < 0.05) and increased EEG connectivity in delta band in prefrontal, temporal, parietal, and occipital areas, and for gamma bands in the left temporo-parietal regions (T = 4.154; p < 0.05). In Task 2, we measured an increased power in the gamma band located in the left posterior midline areas (T = 3.960; p < 0.05) and a significant increase in delta band connectivity in the prefrontal, temporal, parietal, and occipital areas, and in the gamma band involving right temporo-parietal areas (T = 4.579; p < 0.05). These results indicate that AM retrieval engages in a complex network which is mediated by both low- (delta) and high-frequency (gamma) EEG bands.

  11. Lipid composition of liver microsomes and mitochondria after acute and chronic {gamma}-irradiation of rats

    Energy Technology Data Exchange (ETDEWEB)

    Markevich, L.N.; Kolomiitseva, I.K. [Institute of Cell Biophysics, Moscow (Russian Federation)

    1994-07-01

    Acute {gamma}-irradiation of rats at doses of 100 and 270 Gy stimulates lipid synthesis and changes the lipid composition of liver cell organelles. The content of cholesterol and cholesterol esters in microsomes increased at 100 Gy and decreased at 270 Gy, with total phospholipid content remaining unchanged. The lipid content in mitochondria decreased considerably 1 h after irradiation at 270 Gy. This change was significantly less pronounced 47 h later. Under chronic {gamma}-irradiation (0.129 Gy/day), cholesterol and cardiolipin in mitochondria increased. The changes in lipid content caused by acute irradiation are presumed to be related to activated synthesis of lipids in the liver. The modification of the lipid content of mitochondria observed in chronically irradiated rats may indicate that energy-metabolizing liver cell systems are involved in the adaptation to irradiation.

  12. Gamma ray degradation of electrolytes containing alkylcarbonate solvents and a lithium salt

    Energy Technology Data Exchange (ETDEWEB)

    Caillon-Caravanier, Magaly; Jones, Jennifer; Anouti, Meriem; Lemordant, Daniel [Laboratoire CIME/PCMB (EA4244), Universite F. Rabelais, Faculte des Sciences et Techniques, Parc de Grandmont, 37200 Tours (France); Montigny, Frederic [Plateau d' Analyse Chimique, Universite F. Rabelais, Faculte de Pharmacie, 31 avenue Monge 37200 Tours (France); Willmann, Patrick [CNES, 18 avenue E. Belin, 31055 Toulouse (France); David, Jean-Pierre; Soonckindt, Sabine [Departement Environnement Spatial DSEP/ONERA, 2, avenue E. Belin, 31055 Toulouse (France)

    2010-01-15

    Lithium-ion batteries for space applications, such as satellites, are subjected to cosmic radiations, in particular, {gamma}-irradiation. In this study, the effects of this radiation on electrolytes and their components used in the lithium-ion batteries are investigated. The conductivity and viscosity of the samples have been measured before and after the irradiation. The modifications are evaluated by spectral analyses such as Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy ({sup 1}H and {sup 13}C NMR), solid phase microextraction-gas chromatography (SPME-GC) and gas chromatography-mass spectroscopy (GC-MS). The experimental results show that only the samples containing vinylene carbonate and/or the lithium salt LiPF{sub 6} are degraded by {gamma}-radiation. (author)

  13. Quark Deconfinement inside Compact Stars and Gamma Ray Bursts Inner Engine

    CERN Document Server

    Drago, A; Parenti, I; Drago, Alessandro; Pagliara, Giuseppe; Parenti, Irene

    2006-01-01

    The temporal structure of Gamma Ray Bursts can be interpreted assuming as a inner engine a neutron star which undergoes a progressive compactification via production of strangeness (hyperons and kaons) and quarks. We will propose a tentative identification of various emission periods of the burst with specific structural changes of the star. Each of these modifications of the composition of the compact star takes place as a deflagration and not as a detonation, so the energy released in the transition goes mainly into heat and not into a mechanical wave. This is important in order to avoid an excessive baryonic contamination of the region surrounding the compact star. In this way a ultrarelativistic plasma of electron-positron pairs and of photons can be obtained, powering the Gamma Ray Burst.

  14. A separation of electrons and protons in the GAMMA-400 gamma-ray telescope

    CERN Document Server

    Leonov, A A; Bonvicini, V; Topchiev, N P; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, S; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Cumani, P; Dedenko, G L; De Donato, C; Dogiel, V A; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Pearce, M; Picozza, P; Popov, A V; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Suchkov, S I; Tavani, M; Taraskin, A A; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern with the following scientific goals: search for signatures of dark matter, investigation of gamma-ray point and extended sources, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the active Sun, as well as high-precision measurements of spectra of high-energy electrons and positrons, protons, and nuclei up to the knee. The main components of cosmic rays are protons and helium nuclei, whereas the part of lepton component in the total flux is ~10E-3 for high energies. In present paper, the capability of the GAMMA-400 gamma-ray telescope to distinguish electrons and positrons from protons in cosmic rays is investigated. The individual contribution to the proton rejection is studied for each detector system of the GAMMA-400 gamma-ray tel...

  15. Modifications to the INSPECT model

    Energy Technology Data Exchange (ETDEWEB)

    Dickinson, S. [AEA Technology, Winfrith (United Kingdom); Sims, H.E. [AEA Technology, Harwell (United Kingdom)

    1996-12-01

    The prediction of iodine behaviour in the containment of a PWR following a loss of coolant accident requires a reliable model of the chemistry of iodine in aqueous solution. The INSPECT model, which was developed several years ago, contains a large number of the relevant chemical reactions of iodine and water radiation chemistry. Since the reactions set was first assembled, however, new data on rate constants and mechanisms have become available. In addition, the application of the model to various small-scale experiments has revealed problems in the modelling of some reactions, leading to an under-prediction of the iodine volatility at high pH, although the experiments have demonstrated that the high pH volatility remains satisfactory low. This paper describes the modifications which have been made to the INSPECT model to take account of new data and to improve the modelling where appropriate. The main changes which have been made to the reaction set are as follows: - The rate constants and activation energies for the reactions describing the radiolysis of water have been updated in with recent assessments, and the temperature dependence of the G value for the primary species have been accordance taken into account, - The mechanism and rates of I{sub 2} hydrolysis have been modified in accordance with the latest assessments of this reaction, - The mechanism for the reaction of I{sub 2} with H{sub 2}O{sub 2} has been changed to a form which produces a more realistic pH dependence under neutral and alkaline conditions, - An addition mechanism for the disproportionation of the O{sub 2} ion has been included, reflecting experimental observations that this reaction has a significant first-order component under all but the purest conditions, - Atomic I is treated as a volatile species, with a partition coefficient of 1.9 at 298 K. (Abstract Truncated)

  16. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  17. Gamma-Ray Burst Early Afterglows

    CERN Document Server

    Zhang, B

    2005-01-01

    The successful launch and operation of NASA's Swift Gamma-Ray Burst Explorer open a new era for the multi-wavelength study of the very early afterglow phase of gamma-ray bursts (GRBs). GRB early afterglow information is essential to explore the unknown physical composition of GRB jets, the link between the prompt gamma-ray emission and the afterglow emission, the GRB central engine activity, as well as the immediate GRB environment. Here I review some of the recent theoretical efforts to address these problems and describe how the latest Swift data give answers to these outstanding questions.

  18. Atmospheric Cherenkov Gamma-ray Telescopes

    CERN Document Server

    Holder, Jamie

    2015-01-01

    The stereoscopic imaging atmospheric Cherenkov technique, developed in the 1980s and 1990s, is now used by a number of existing and planned gamma-ray observatories around the world. It provides the most sensitive view of the very high energy gamma-ray sky (above 30 GeV), coupled with relatively good angular and spectral resolution over a wide field-of-view. This Chapter summarizes the details of the technique, including descriptions of the telescope optical systems and cameras, as well as the most common approaches to data analysis and gamma-ray reconstruction.

  19. The propagation of gamma quanta in matter

    CERN Document Server

    Lejpunskij, Ovsej Ilich; Sakharov, Vsevolod Nikolaevich

    1965-01-01

    The Propagation of Gamma Quanta in Matter deals with various problems of the propagation and absorption of gamma quanta in matter, particularly the occurrence of multiple scattering of radiation. The ultimate objective is to determine the material, size, and configuration that will ensure the safe absorption of nuclear radiation. Shield design problems are given, the solution of which is achieved using numerical data presented in graphs and tables. This volume is comprised of three chapters and begins with an overview of the interaction of gamma radiation with matter and multiple scattering of

  20. Gamma-Knife: operation ohne Skalpell

    OpenAIRE

    АБЛЯЕВА В.И.; НИКОЛАЕВА Н.А.; ДЕНИСОВА О.С.

    2015-01-01

    Das Gamma-Knife ist ein Operationsroboter, mit dem Ärzte durch Photonenstrahlen im Körper operieren können. Die Photonen beschädigen die DNA von Zellen, so dass diese sich nicht mehr teilen können. Gutartige Tumoren vernarben in den Wochen und Monaten nach der Behandlung, bösartige zerfallen. Mit dem Gamma-Knife können unterschiedliche Arten von Tumoren behandelt werden, gutartige ebenso wie bösartige. Zu den Diagnosen, bei denen das Gamma-Knife in Frage kommt, gehören zum Beispiel Akustikusn...

  1. Modeling gamma-ray bursts

    Science.gov (United States)

    Maxham, Amanda

    Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground to those who study them, from relativistic effects such as beaming, jets, shocks and blastwaves to radiation mechanisms such as synchrotron radiation to galatic and stellar populations and history. Through the Swift and Fermi space telescopes dedicated to observing GRBs over a wide range of energies (from keV to GeV), combined with accurate pinpointing that allows ground based follow-up observations in the optical, infrared and radio, a rich tapestry of GRB observations has emerged. The general picture is of a mysterious central engine (CE) probably composed of a black hole or neutron star that ejects relativistic shells of matter into intense magnetic fields. These shells collide and combine, releasing energy in "internal shocks" accounting for the prompt emission and flaring we see and the "external shock" or plowing of the first blastwave into the ambient surrounding medium has well-explained the afterglow radiation. We have developed a shell model code to address the question of how X-ray flares are produced within the framework of the internal shock model. The shell model creates randomized GRB explosions from a central engine with multiple shells and follows those shells as they collide, merge and spread, producing prompt emission and X-ray flares. We have also included a blastwave model, which can constrain X-ray flares and explain the origin of high energy (GeV) emission seen by the Fermi telescope. Evidence suggests that gamma-ray prompt emission and X-ray flares share a common origin and that at least some flares can only be explained by long-lasting central engine activity. We pay special attention to the time history of central engine activity, internal shocks, and observed flares. We calculate the gamma-ray (Swift/BAT band) and X-ray (Swift/XRT band) lightcurves for arbitrary

  2. Dipole strength in 144Sm studied via (gamma,n), (gamma,p) and (gamma,alpha) reactions

    CERN Document Server

    Nair, Chithra; Erhard, Martin; Bemmerer, Daniel; Beyer, Roland; Grosse, Eckart; Kosev, Krasimir; Marta, Michele; Rusev, Gencho; Schilling, Klaus-Dieter; Schwengner, Ronald; Wagner, Andreas

    2010-01-01

    Photoactivation measurements on 144Sm have been performed with bremsstrahlung endpoint energies from 10.0 to 15.5 MeV at the bremsstrahlung facility of the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf. The measured activation yield for the 144Sm(gamma,n) reaction is compared with the calculated yield using cross sections from previous photoneutron experiments. The activation yields measured for all disintegration channels 144Sm(gamma,n), (gamma,p) and (gamma,alpha) are compared to the yield calculated by using Hauser-Feshbach statistical models. A new parametrization of the photon strength function is presented and the yield simulated by using the modified photon strength parameters are compared to the experimental data.

  3. Gamma-Gamma Angular Correlation Measurements With GRIFFIN

    Science.gov (United States)

    Maclean, Andrew; Griffin Collaboration

    2016-09-01

    The goal of this work was to explore the sensitivity of the Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) 16 clover-detector γ-ray spectrometer at TRIUMF-ISAC to such γ - γ angular correlations. The methodology was established using both experimental measurements and Geant4 simulations that were used to create angular correlation templates for the GRIFFIN geometry. Direct comparisons were made between experimental data sets and the simulated angular correlation templates. A first in-beam test of the γ - γ angular correlation measurements with GRIFFIN was performed with a radioactive beam of 66Ga. Mixing ratios of δ = - 2 . 1(2) and δ = - 0 . 08(3) were measured for the 2+ ->2+ ->0+ 833-1039 keV and 1+ ->2+ ->0+ 2752-1039 keV cascades in the daughter nucleus 66Zn. These results are in good agreement with pervious literature values and the mixing ratio for the 833-1039 keV cascade has a higher precision. Also, the sensitivity to the 1333-1039 keV cascade, with its pronounced 0+ ->2+ ->0+ angular correlation, was measured.A test measurement of the superallowed Fermi β emitter 62Ga will also be discussed. Canada Foundation of Innovation, Natural Sciences and Engineering Research Council of Canada, National Research Council of Canada and Canadian Research Chairs Program.

  4. GammaLib - A new framework for the analysis of Astronomical Gamma-Ray Data

    CERN Document Server

    Knödlseder, Jürgen

    2011-01-01

    With the advent of a new generation of telescopes (INTEGRAL, Fermi, H.E.S.S., MAGIC, VERITAS, MILAGRO) and the prospects of planned observatories such as CTA or HAWC, gamma-ray astronomy is becoming an integral part of modern astrophysical research. Analysing gamma-ray data is still a major challenge, and today relies on a large diversity of tools and software frameworks that were specifically developed for each instrument. With the goal of facilitating and unifying the analysis of gamma-ray data, we are currently developing an innovative data analysis toolbox, called the GammaLib, that enables gamma-ray data analysis in an instrument independent way. We will present the basic ideas that are behind the GammaLib, and describe its architecture and usage.

  5. GammaLib: A New Framework for the Analysis of Astronomical Gamma-Ray Data

    Science.gov (United States)

    Knödlseder, J.

    2012-09-01

    With the advent of a new generation of telescopes (INTEGRAL, Fermi, H.E.S.S., MAGIC, VERITAS, MILAGRO) and the prospects of planned observatories such as CTA or HAWC, gamma-ray astronomy is becoming an integral part of modern astrophysical research. Analysing gamma-ray data is still a major challenge, and today relies on a large diversity of tools and software frameworks that were specifically developed for each instrument. With the goal of facilitating and unifying the analysis of gamma-ray data, we are currently developing an innovative data analysis toolbox, called the GammaLib, that enables gamma-ray data analysis in an instrument independent way. We will present the basic ideas that are behind the GammaLib, and describe its architecture and usage.

  6. A Search for the Rare Decay $B\\rightarrow\\gamma\\gamma$

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-06-02

    We report the result of a search for the rare decay B{sup 0} {yields} {gamma}{gamma} in 426 fb{sup -1} of data, corresponding to 226 million B{sup 0}{bar B}{sup 0} pairs, collected on the {Upsilon}(4S) resonance at the PEP-II asymmetric-energy e{sup +}e{sup -} collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 21{sub -12}{sup +13} signal events with a statistical signficance of 1.9 {sigma}. This corresponds to a branching fraction {Beta}(B{sup 0} {yields} {gamma}{gamma}) = (1.7 {+-} 1.1(stat.) {+-} 0.2(syst.)) x 10{sup -7}. Based on this result, we set a 90% confidence level upper limit of {Beta}(B{sup 0} {yields} {gamma}{gamma}) < 3.2 x 10{sup -7}.

  7. GAMMA-RAY AND X-RAY EMISSION FROM GAMMA-RAY-LOUD BLAZARS

    Institute of Scientific and Technical Information of China (English)

    ZHANG XIONG; ZHAO GANG; XIE GUANG-ZHONG; ZHENG GUANG-SHENG; ZHANG LI

    2001-01-01

    We present a strong correlation of the gamma-ray (above 100 MeV) mean spectral indices aγ and X-ray (1 keV)mean spectral indices cX for 34 gamma-ray-loud blazars (16 BL Lac objects and 18 flat spectrum radio quasars). Astrong correlation is also found between the gamma-ray flux densities F-γ and X-ray flux densities Fx in the low state for 47 blazars (17 BL Lac and 30 flat spectrum radio quasars). Possible correlation on the gamma-ray emission mechanism is discussed. We suggest that the main gamma-ray radiation mechanism is probably the synchrotron process. The gamma-ray emission may be somewhat different from that of BL Lac objects and flat spectrum radio quasars.

  8. Effect of gamma-irradiation on the foaming behavior of ethylene-co-octene polymers

    Energy Technology Data Exchange (ETDEWEB)

    Vachon, C. E-mail: caroline.vachon@nrc.ca; Gendron, R

    2003-04-01

    Ethylene-co-octene polymers containing different branching levels were irradiated in air and under vacuum at 25, 50 and 100 kGy. Gel fraction measurements, thermal analysis and rheology were used to assess the effect of the treatment on polymer structure modifications. The copolymer with 24 wt% octene was shown to be more sensitive to gamma rays and degradation was observed in some cases. Cross-linking in the amorphous phase also occurred as a consequence of irradiation and affected the foaming behavior of these materials.

  9. Physical modification of polyetheretherketone for orthopedic implants

    Science.gov (United States)

    Du, Ya-Wei; Zhang, Li-Nan; Hou, Zeng-Tao; Ye, Xin; Gu, Hong-Sheng; Yan, Guo-Ping; Shang, Peng

    2014-12-01

    Polyetheretherketone (PEEK) is regarded as one of the most potential candidates for replacing current implant applications. To obtain good bone-implant interfaces, many modification methods have been developed to enable PEEK and PEEK-based composites from bio-inert to bioactive. Among them, physical methods have aroused significant attention and been widely used to modify PEEK for orthopedic implants. This review summarizes current physical modification techniques of PEEK for orthopedic applications, which include composite strategies, surface coating methods and irradiation treatments. The positive consequences of those modification methods will encourage continuing investigations and stimulate the wide range of applications of PEEK-based implants in orthopedics.

  10. [Behavior modification therapy: application in renal nursing].

    Science.gov (United States)

    Wang, Lu-Mei; Hung, Shih-Yuan; Chiou, Chou-Ping

    2011-04-01

    Kidney patients often suffer numerous comorbidities (e.g., hyperphosphatemia, renal osteodystrophy, and bodyweight gain induced by fluid overload or hypertension), which often impart discomfort and a significantly reduced quality of life. The literatures points to the efficacy of behavior modification therapy in changing inappropriate self-health care behavior in order to improve comorbidity symptoms. This article introduces behavior modification theory and its application as well as clinical strategies related to kidney patient care. The authors hope this article will promote knowledge of behavior modification theory among healthcare professionals and facilitate to the application of this theory in clinical practice to improve nursing care.

  11. Epigenetic Modifications: Therapeutic Potential in Cancer

    Directory of Open Access Journals (Sweden)

    Manisha Sachan

    2015-08-01

    Full Text Available Epigenetic modifications and alterations in chromatin structure and function contribute to the cumulative changes observed as normal cells undergo malignant transformation. These modifications and enzymes (DNA methyltransferases, histone deacetylases, histone methyltransferases, and demethylases related to them have been deeply studied to develop new drugs, epigenome-targeted therapies and new diagnostic tools. Epigenetic modifiers aim to restore normal epigenetic modification patterns through the inhibition of epigenetic modifier enzymes. Four of them (azacitidine, decitabine, vorinostat and romidepsin are approved by the U.S. Food and Drug Administration. This article provides an overview about the known functional roles of epigenetic enzymes in cancer development.

  12. Renormalization of dimension-six operators relevant for the Higgs decays $h\\rightarrow \\gamma\\gamma,\\gamma Z$

    CERN Document Server

    Elias-Miró, J; Masso, E; Pomarol, A

    2013-01-01

    The discovery of the Higgs boson has opened a new window to test the SM through the measurements of its couplings. Of particular interest is the measured Higgs coupling to photons which arises in the SM at the one-loop level, and can then be significantly affected by new physics. We calculate the one-loop renormalization of the dimension-six operators relevant for $h\\rightarrow \\gamma\\gamma, \\gamma Z$, which can be potentially important since it could, in principle, give log-enhanced contributions from operator mixing. We find however that there is no mixing from any current-current operator that could lead to this log-enhanced effect. We show how the right choice of operator basis can make this calculation simple. We then conclude that $h\\rightarrow \\gamma\\gamma, \\gamma Z$ can only be affected by RG mixing from operators whose Wilson coefficients are expected to be of one-loop size, among them fermion dipole-moment operators which we have also included.

  13. Measurement of \\Gamma(\\eta -> \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta -> \\pi^+\\pi^-\\pi^0) with the KLOE Detector

    CERN Document Server

    Babusci, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Budano, A; Caldeira Balkest, L; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; De Simone, P; Di Domenico, A; Di Donato, C; Di Micco, B; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giardina, G; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Prado Longhi, I; Ranieri, A; Redmer, C.F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Versaci, R; Wislicki, W; Wolke, M; Xu, G; Zdebik, J

    2013-01-01

    The ratio R_{\\eta}=\\Gamma(\\eta -> \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta -> \\pi^+\\pi^-\\pi^0) has been measured by analyzing 22 million \\phi \\to \\eta \\gamma decays collected by the KLOE experiment at DA\\PhiNE, corresponding to an integrated luminosity of 558 pb^{-1}. The \\eta \\to \\pi^+\\pi^-\\gamma proceeds both via the \\rho resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, R_{\\eta}= 0.1856\\pm 0.0005_{stat} \\pm 0.0028_{syst}, points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the \\eta -> \\pi^+\\pi^-\\gamma decay could be described in a model-independent approach in terms of a single free parameter, \\alpha. The determined value of the parameter \\alpha is \\alpha = (1.32 \\pm 0.08_{stat} +0.10/-0.09_{syst}\\pm 0.02_{theo}) GeV^{-2}

  14. Tests of quantum chromodynamics in exclusive e sup + e sup minus and. gamma. gamma. processes

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1989-09-01

    This paper discusses the following topics: Factorization theorem for exclusive processes; Electromagnetic form factors of baryons; Suppression of final state interactions; The {gamma}{pi}{sub 0} Transition form factor; Exclusive charmonium decays; The {pi}-{rho} puzzle; Time-like compton processes; Multi-hadron production; Heavy Quark exclusive states and form factor zeros in QCD; Exclusive {gamma}{gamma} reactions; Higher twist effects; and Tauonium and threshold {tau}{sup +}{tau}{sup {minus}} production. 41 refs., 15 figs. (LSP)

  15. Effect of radiation-induced modification in fluoroelastomer

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto; Lugao, Ademar Benevolo, E-mail: helozen@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Polymers exposed to ionizing irradiation, even at low doses, often undergo structural changes accompanied by molecular crosslinking and chain scission (degradation) reactions. The general effect of the radiation on polymers is determined by the ratio of crosslinking to chain scission events. This ratio depends on parameters such as chemical structure, physical state, radicals stability and mobility, irradiation rate and irradiation atmosphere. The radiation process is a large used technique to promote modification in their structures to apply them in different areas and is well known for its merits and potential in modifying the chemical and the physical properties of polymeric materials without cause drastic changes in their inherent properties, depend on the dose irradiated. In this study was used fluoroelastomer with 70% - fluor that having excellent thermal, chemical and mechanical properties. Vulcanized and non-vulcanized samples of this material were submitted to gamma radiation under air atmosphere in order to observe the effect of atmosphere in the polymer matrix. The irradiated doses were 5, 10 and 20kGy, at room temperature. The characterization was made by scanning electron microscope (SEM), infrared spectroscopy using attenuate reflectance (ATR-IR) and X-ray diffraction. The results demonstrated which was expected, the degradation reactions were observed. (author)

  16. Strong Equivalence, Lorentz and CPT Violation, Anti-Hydrogen Spectroscopy and Gamma-Ray Burst Polarimetry

    CERN Document Server

    Shore, G M

    2004-01-01

    The strong equivalence principle, local Lorentz invariance and CPT symmetry are fundamental ingredients of the quantum field theories used to describe elementary particle physics. Nevertheless, each may be violated by simple modifications to the dynamics while apparently preserving the essential fundamental structure of quantum field theory itself. In this paper, we analyse the construction of strong equivalence, Lorentz and CPT violating Lagrangians for QED and review and propose some experimental tests in the fields of astrophysical polarimetry and precision atomic spectroscopy. In particular, modifications of the Maxwell action predict a birefringent rotation of the direction of linearly polarised radiation from synchrotron emission which may be studied using radio galaxies or, potentially, gamma-ray bursts. In the Dirac sector, changes in atomic energy levels are predicted which may be probed in precision spectroscopy of hydrogen and anti-hydrogen atoms, notably in the Doppler-free, two-photon $1s-2s$ and...

  17. Supernova remnants and gamma-ray sources

    CERN Document Server

    Torres, D F; Dame, T M; Combi, J A; Butt, Y M; Torres, Diego F.; Romero, Gustavo E.; Dame, Thomas M.; Combi, Jorge A.; Butt, Yousaf M.

    2003-01-01

    A review of the possible relationship between $\\gamma$-ray sources and supernova remnants (SNRs) is presented. Particular emphasis is given to the analysis of the observational status of the problem of cosmic ray acceleration at SNR shock fronts. All positional coincidences between SNRs and unidentified $\\gamma$-ray sources listed in the Third EGRET Catalog at low Galactic latitudes are discussed on a case by case basis. For several coincidences of particular interest, new CO(J=1-0) and radio continuum maps are shown, and the mass content of the SNR surroundings is determined. The contribution to the $\\gamma$-ray flux observed that might come from cosmic ray particles (particularly nuclei) locally accelerated at the SNR shock fronts is evaluated. We discuss the prospects for future research in this field and remark on the possibilities for observations with forthcoming $\\gamma$-ray instruments.

  18. HotSpotter? Neutron/Gamma Detector

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.W.

    2003-04-01

    The HotSpotter{trademark} Neutron/Gamma Detector combines in a single detecting module high sensitivity to gamma rays up to 3 MeV and sensitivity to neutrons. Using a 15 mm cubic CdWO{sub 4} (cadmium tungstate) crystal mounted on a 25 mm photomultiplier, the instrument realizes a factor of 5 increased photopeak efficiency over NaI(Tl) at 1 MeV, and a factor of 2 improvement over CsI(Tl). The addition of a 0.5 mm layer of {sup 10}B- impregnated epoxy covering the crystal provides neutron sensitivity without sacrificing gamma ray spectroscopic characteristics. Neutrons are detected by the presence of the 478 keV gamma from the {sup 10}B(n,{alpha}){sup 7}Li* reaction. In this paper, we describe the electronics and software of the instrument, and some of its characteristics.

  19. Scalar decays to $\\gamma\\gamma$, $Z\\gamma$, and $W\\gamma$ in the Georgi-Machacek model arXiv

    CERN Document Server

    Degrande, Celine; Logan, Heather E.

    We compute the decay widths for the neutral and singly-charged Higgs bosons in the Georgi-Machacek model into the final states $\\gamma\\gamma$, $Z\\gamma$, and $W\\gamma$. These decays are most phenomenologically interesting for the fermiophobic custodial fiveplet states $H_5^0$ and $H_5^{\\pm}$ when their masses are below threshold for decays into $WW$, $ZZ$, or $WZ$. We study the allowed branching ratios into these final states using scans over the allowed parameter space, and show how the model can be constrained by LEP searches for a fermiophobic Higgs boson decaying to two photons. The calculation involves evaluating one-loop diagrams in which the loop contains particles with two different masses, some of which do not appear in the existing literature. We give results for these diagrams in a form convenient for numerical implementation using the LoopTools package.

  20. Bound-state effects in $\\mu^{+}e^{-} \\to \\gamma\\gamma$ and $\\overline{B}^{0}_{s} \\to \\gamma\\gamma$ decays

    CERN Document Server

    Eeg, Jan O; Picek, I

    2000-01-01

    We demonstrate that in the double-radiative decays of heavy-light QED and QCD atoms, \\mu^{+} e^{-} \\to \\gamma\\gamma and \\bar{B}^{0}_{s} \\to \\gamma\\gamma, there is a contribution coming from operators that vanish on the free-quark mass shell. This off-shell effect is suppressed with respect to the effect of the well known flavour-changing magnetic-moment operator by the bound-state binding factor. Accordingly, the negligible off-shellness of the weakly bound QED atoms becomes important for strongly bound QCD atoms. We present this effect in two different model-approaches to QCD, one of them enabling us to keep close contact to the related effect in QED.

  1. Measuring cosmology with Gamma-Ray Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Z.G.; Xu, D.; Liang, W. [Nanjing Univ., Nanjing (Switzerland). Department of Astronomy

    2005-07-15

    Gamma-Ray Bursts (GRBs) are becoming more and more standardizable candles. Different methods have been proposed to measure cosmology with the relation between the {gamma}-ray energy E{sub {gamma}} of a GRB jet and the peak energy E{sub p} of the {nu}F{nu} spectrum in the burst frame. We compare the procedures and results of these methods. Using the present sample of 17 GRBs, we obtain a constraint on the mass density {omega}M 0.22{sub -0.07}{sup +0.42} (1{sigma}) for a flat ACDM universe with the median circumburst density n {approx_equal} 3.0 cm{sup -3}. Theoretical investigations of the E{sub {gamma}} {alpha} E{sub p}{sup a} relation reach a {approx} 1.5. A larger sample in the Swift era is expected to provide further constraints on the GRB cosmography.

  2. Monochromatic gamma emitter for low energy quanta

    CERN Document Server

    Tomova, Z R; Mironova, S A

    2004-01-01

    The possibility of creating of a monochromatic gamma emitter of low energy quanta is analyzed. The idea is based on Daning's scheme. Except for purely scientific problems the monochromator is actual for therapy of wide range of diseases.

  3. A localized excess of diffuse gamma radiation

    Science.gov (United States)

    Chen, A.; Dwyer, J.; Kaaret, P.

    1995-01-01

    Using archival Energetic Gamma Ray Experiment Telescope (EGRET) gamma-ray data and atomic hydrogen (H I) column densities derived from 21 cm radio observations, we have found a large irregular region in the northern Galactic hemisphere extending from (l approximately 90 deg, b approximately 52 deg) to (l approximately 45 deg, b approximately 77 deg) with a significant enhancement in the gamma-ray emissivity compared to the surrounding sky. The region contains no previously identified gamma-ray point sources. The emission may arise from a localized enhancement in cosmic-ray density or from the presence of matter other than H I. If the emission is due to unseen matter, a column density enhancement equivalent to approximately 2 x 10(exp 20) H-atoms/sq cm is required.

  4. Gamma knife radiosurgery for cerebral arteriovenous malformations.

    Science.gov (United States)

    Kemeny, A A; Radatz, M W R; Rowe, J G; Walton, L; Hampshire, A

    2004-01-01

    Since its introduction, gamma knife radiosurgery has become an important treatment modality for cerebral arteriovenous malformations. This paper is a brief overview of the technique used, of the clinical results achieved and of the experience gained in Sheffield.

  5. Gamma beam system at ELI-NP

    Energy Technology Data Exchange (ETDEWEB)

    Ur, Calin Alexandru, E-mail: calin.ur@eli-np.ro [Extreme Light Infrastructure, IFIN-HH, Magurele-Bucharest (Romania)

    2015-02-24

    The Gamma Beam System of ELI-NP will produce brilliant, quasi-monochromatic gamma-ray beams via Inverse Compton Scattering of short laser pulses on relativistic electron beam pulses. The scattered radiation is Doppler upshifted by more than 1,000,000 times and is forward focused in a narrow, polarized, tunable, laser-like beam. The gamma-ray beam at ELI-NP will be characterized by large spectral density of about 10{sup 4} photons/s/eV, narrow bandwidth (< 0.5%) and tunable energy from 200 keV up to about 20 MeV. The Gamma Beam System is a state-of-the-art equipment employing techniques and technologies at the limits of the present-day's knowledge.

  6. Gamma-Ray Astrophysics NSSTC Fermi GBM

    Data.gov (United States)

    National Aeronautics and Space Administration — The Fermi Gamma-Ray Burst Monitor (GBM) is not a pointed or imaging instrument. To determine fluxes for known sources, we measure the change in the count rate...

  7. The $e^+ e^- \\to Z\\gamma\\gamma \\to q\\overline{q}\\gamma\\gamma$ Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, Michael; Doria, A; Dova, M T; Duchesneau, D; Echenard, B; Eline, A; El-Mamouni, H; Engler, A; Eppling, F J; Ewers, A; Extermann, Pierre; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Latt, J; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Pandoulas, D; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R P; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wallraff, W; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2002-01-01

    The cross section of the process e^+ e^- -> Z \\gamma\\gamma -> qq~ \\gamma \\gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/\\Lambda^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/\\Lambda^2 < 0.05 GeV^-2, at 95% confidence level.

  8. Search for the rare decay $D^0\\to\\gamma\\gamma$ at Belle

    CERN Document Server

    Nisar, N K; Trabelsi, K; Aziz, T; Abdesselam, A; Adachi, I; Aihara, H; Asner, D M; Aulchenko, V; Aushev, T; Ayad, R; Babu, V; Badhrees, I; Bahinipati, S; Barberio, E; Behera, P; Bhardwaj, V; Biswal, J; Bobrov, A; Bozek, A; Bračko, M; Breibeck, F; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Dash, N; Doležal, Z; Drásal, Z; Drutskoy, A; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Fulsom, B G; Gaur, V; Garmash, A; Gillard, R; Goh, Y M; Goldenzweig, P; Greenwald, D; Grzymkowska, O; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; He, X H; Hou, W -S; Inami, K; Ishikawa, A; Iwasaki, Y; Jacobs, W W; Jaegle, I; Jeon, H B; Joffe, D; Joo, K K; Julius, T; Kang, K H; Kato, E; Kawasaki, T; Kiesling, C; Kim, D Y; Kim, H J; Kim, K T; Kim, M J; Kim, S H; Kinoshita, K; Kodyš, P; Korpar, S; Križan, P; Krokovny, P; Kuhr, T; Kumar, R; Kumita, T; Kuzmin, A; Kwon, Y -J; Lee, I S; Lange, J S; Li, H; Li, L; Gioi, L Li; Libby, J; Liventsev, D; Lukin, P; Masuda, M; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Mohanty, S; Moll, A; Moon, H K; Mori, T; Mussa, R; Nakano, E; Nakao, M; Nanut, T; Natkaniec, Z; Nayak, M; Niiyama, M; Nishida, S; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Pal, B; Park, C W; Park, H; Paul, S; Pedlar, T K; Pesántez, L; Pestotnik, R; Petrič, M; Piilonen, L E; Prasanth, K; Pulvermacher, C; Rauch, J; Ribežl, E; Ritter, M; Rostomyan, A; Ryu, S; Sahoo, H; Sandilya, S; Sanuki, T; Sato, Y; Savinov, V; Schlüter, T; Schneider, O; Schnell, G; Schwanda, C; Schwartz, A J; Seino, Y; Senyo, K; Seon, O; Seong, I S; Shebalin, V; Shibata, T -A; Shiu, J -G; Shwartz, B; Simon, F; Singh, J B; Sohn, Y -S; Solovieva, E; Stanič, S; Starič, M; Stypula, J; Sumihama, M; Sumiyoshi, T; Tamponi, U; Teramoto, Y; Uchida, M; Uglov, T; Uno, S; Urquijo, P; Van Hulse, C; Vanhoefer, P; Varner, G; Varvell, K E; Vinokurova, A; Vossen, A; Wagner, M N; Wang, C H; Wang, M -Z; Wang, X L; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yelton, J; Yuan, C Z; Yusa, Y; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A

    2015-01-01

    We search for the rare radiative decay $D^0\\to\\gamma\\gamma$ using a data sample with an integrated luminosity of $832{\\rm fb^{-1}}$ recorded by the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. We find no statistically significant signal and set an upper limit on the branching fraction of ${\\cal B}(D^0\\to\\gamma\\gamma)<8.5\\times10^{-7}$ at $90\\%$ confidence level. This is the most restrictive limit on the decay channel to date.

  9. The HAWC Gamma-Ray Observatory: Sensitivity to Steady and Transient Sources of Gamma Rays

    CERN Document Server

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiñana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, L X; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivière, C; Rosa-González, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseñor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2013-01-01

    The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is designed to record air showers produced by cosmic rays and gamma rays between 100 GeV and 100 TeV. Because of its large field of view and high livetime, HAWC is well-suited to measure gamma rays from extended sources, diffuse emission, and transient sources. We describe the sensitivity of HAWC to emission from the extended Cygnus region as well as other types of galactic diffuse emission; searches for flares from gamma-ray bursts and active galactic nuclei; and the first measurement of the Crab Nebula with HAWC-30.

  10. Investigation of selected toxicological parameters of gamma-pentachlorocyclohexene (gamma-PCCH).

    Science.gov (United States)

    Mazzag, E; Nagymajtenyi, L; Huszta, E; Desi, I; Macholz, R

    1991-01-01

    The toxic effects of the gamma-hexachlorocyclohexane metabolite gamma-pentachlorocyclohexene (gamma-PCCH) were studied by acute and subacute (6 weeks) experiments. The investigations included cerebral convulsibility with chemoshock (Tetrazolium), reactivity with hot plate method, the learning ability with learning tests, and peripheral nervous activity (EMG). Nociceptive reaction time was not influenced, the learning process (6 weeks) was inhibited by gamma-PCCH. The conduction velocity of the peripheral nerve was decreased. At the end of the 6th week liver enlargement was found.

  11. Electrophoretic separation of A gamma and G gamma human globin chains in Nonidet P-40.

    Science.gov (United States)

    Guerrasio, A; Saglio, G; Mazza, U; Pich, P; Camaschella, C; Ricco, G; Gianazza, E; Righetti, P G

    1979-11-15

    Electrophoresis in cellulose acetate in the presence of 3% Nonidet P-40 can resolve two neutral genetic variants, A gamma and G gamma human fetal globin chains. The ratio of these two chains, determined by densitometry of the electrophoretic strips, is in excellent agreement with the Gly-Ala ratio obtained by chemical analysis of the cyanogen bromide fragment gamma CB3. It is suggested that the detergent binds preferentially to the hydrophobic amino acid segment 133-141 in the A gamma chain, thus masking either a Lys or an Arg residue at the two extremes.

  12. The decay eta$_{c}$ --> $\\gamma$. gamma.: a test for potential models

    CERN Document Server

    Ahmady, M R; Mohammad R Ahmady; Roberto R Mendel

    1995-01-01

    We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\\Gamma (\\psi_{NS} \\rightarrow e^+e^-)$ to estimate the ratio \\mbox{$R_\\circ \\equiv {\\vert \\Psi _{\\eta_{c1S}}(0) \\vert}^2 /{\\vert\\Psi_{\\psi_{1 S}}(0)\\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\\circ = 1.4 \\pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )/\\Gamma (\\psi_{1S} \\rightarrow e^+e^-) \\approx 2.2\\pm 0.2$. The central value for $\\Gamma (\\psi_{1S} \\rightarrow e^+ e^-)$ in the 1992 Particle Data Tables then leads to a prediction $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )\\approx 11.8\\pm 0.8 $keV. This prediction is in good agreement with a recent measurement by the ARGUS collaboration, is consistent with a recent measurement by the L3 collaboration but is significantly higher than several earlier measurements and than previous theoretical estimates, which usually assum...

  13. The Decay $\\eta_c \\rightarrow \\gamma \\gamma$ : A Test for Potential Models

    OpenAIRE

    Ahmady, M. R.; Mendel, R. R.

    1994-01-01

    We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\\Gamma (\\psi_{NS} \\rightarrow e^+e^-)$ to estimate the ratio \\mbox{$R_\\circ \\equiv {\\vert \\Psi _{\\eta_{c1S}}(0) \\vert}^2 /{\\vert\\Psi_{\\psi_{1 S}}(0)\\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\\circ = 1.4 \\pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )/\\...

  14. The Decay $\\eta_c \\rightarrow \\gamma \\gamma$ : A Test for Potential Models

    CERN Document Server

    Ahmady, M R

    1995-01-01

    We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\\Gamma (\\psi_{NS} \\rightarrow e^+e^-)$ to estimate the ratio \\mbox{$R_\\circ \\equiv {\\vert \\Psi _{\\eta_{c1S}}(0) \\vert}^2 /{\\vert\\Psi_{\\psi_{1 S}}(0)\\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\\circ = 1.4 \\pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )/\\Gamma (\\psi_{1S} \\rightarrow e^+e^-) \\approx 2.2\\pm 0.2$. The central value for $\\Gamma (\\psi_{1S} \\rightarrow e^+ e^-)$in the 1992 Particle Data Tables then leads to a (non relativistic) prediction $\\Gamma (\\eta_c \\rightarrow \\gamma \\gamma )\\approx 11.8\\pm 0.8 $ keV. This prediction is in good agreement with a recent measurement by the ARGUS collaboration, is consistent with a recent measurement by the L3 collaboration but is significantly higher than several earlier measurements and than previous theoretical estimates, ...

  15. Gamma-Ray Burst Progenitors

    Science.gov (United States)

    Levan, Andrew; Crowther, Paul; de Grijs, Richard; Langer, Norbert; Xu, Dong; Yoon, Sung-Chul

    2016-12-01

    We review our current understanding of the progenitors of both long and short duration gamma-ray bursts (GRBs). Constraints can be derived from multiple directions, and we use three distinct strands; (i) direct observations of GRBs and their host galaxies, (ii) parameters derived from modelling, both via population synthesis and direct numerical simulation and (iii) our understanding of plausible analog progenitor systems observed in the local Universe. From these joint constraints, we describe the likely routes that can drive massive stars to the creation of long GRBs, and our best estimates of the scenarios that can create compact object binaries which will ultimately form short GRBs, as well as the associated rates of both long and short GRBs. We further discuss how different the progenitors may be in the case of black hole engine or millisecond-magnetar models for the production of GRBs, and how central engines may provide a unifying theme between many classes of extremely luminous transient, from luminous and super-luminous supernovae to long and short GRBs.

  16. On Gamma-Ray Bursts

    CERN Document Server

    Ruffini, Remo; Bianco, Carlo Luciano; Caito, Letizia; Chardonnet, Pascal; Cherubini, Christian; Dainotti, Maria Giovanna; Fraschetti, Federico; Geralico, Andrea; Guida, Roberto; Patricelli, Barbara; Rotondo, Michael; Hernandez, Jorge Armando Rueda; Vereshchagin, Gregory; Xue, She-Sheng

    2008-01-01

    (Shortened) We show by example how the uncoding of Gamma-Ray Bursts (GRBs) offers unprecedented possibilities to foster new knowledge in fundamental physics and in astrophysics. After recalling some of the classic work on vacuum polarization in uniform electric fields by Klein, Sauter, Heisenberg, Euler and Schwinger, we summarize some of the efforts to observe these effects in heavy ions and high energy ion collisions. We then turn to the theory of vacuum polarization around a Kerr-Newman black hole, leading to the extraction of the blackholic energy, to the concept of dyadosphere and dyadotorus, and to the creation of an electron-positron-photon plasma. We then present a new theoretical approach encompassing the physics of neutron stars and heavy nuclei. It is shown that configurations of nuclear matter in bulk with global charge neutrality can exist on macroscopic scales and with electric fields close to the critical value near their surfaces. These configurations may represent an initial condition for the...

  17. Gamma-scintigraphy; La gammascintigraphie

    Energy Technology Data Exchange (ETDEWEB)

    Desgrez, H.A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-06-15

    Gamma-scintigraphy is a medical technique making it possible to fix the image of certain organs after the concentration in these of emitting radioactive products. It is already widely used in the case of the thyroid gland with iodine-132 by applying the isotope iodine 131. The study of the liver and gall bladder is carried out using colloidal gold 198 and Bengal pink marked with iodine 131. Serum albumin marked with iodine 131 makes it possible to study rachidian blockages. Other applications can already be foreseen in this direction. (author) [French] La gammascintigraphie est une technique medicale permettant de faire l'image de certains organes apres concentration dans ceux-ci de produits radioactifs emetteurs. Son utilisation deja repandue en ce qui concerne la thyroidine et l'iode-131 est possible avec l'iode-132 pour cette meme glande. Avec l'or colloidal 198 et le rose bengale marque a l'iode-131, on pratique des etudes du foie et de la vesicule biliaire. La serumalbumine marquee a l'iode-131 permet d'etudier les blocages rachidiens. D'autres possibilites sont des maintenant envisageables dans cette direction. (auteur)

  18. Gamma-ray burst progenitors

    CERN Document Server

    Levan, Andrew; de Grijs, Richard; Langer, Norbert; Xu, Dong; Yoon, Sung-Chul

    2016-01-01

    We review our current understanding of the progenitors of both long and short duration gamma-ray bursts (GRBs). Constraints can be derived from multiple directions, and we use three distinct strands; i) direct observations of GRBs and their host galaxies, ii) parameters derived from modeling, both via population synthesis and direct numerical simulation and iii) our understanding of plausible analog progenitor systems observed in the local Universe. From these joint constraints, we describe the likely routes that can drive massive stars to the creation of long GRBs, and our best estimates of the scenarios that can create compact object binaries which will ultimately form short GRBs, as well as the associated rates of both long and short GRBs. We further discuss how different the progenitors may be in the case of black hole engine or millisecond-magnetar models for the production of GRBs, and how central engines may provide a unifying theme between many classes of extremely luminous transient, from luminous an...

  19. Gamma-ray Burst Cosmology

    CERN Document Server

    Wang, F Y; Liang, E W

    2015-01-01

    Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to $8.8\\times10^{54}$ erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the largest distances yet explored in the Universe. GRBs, as bright beacons in the deep Universe, would be the ideal tool to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal enrichment history of the Universe. In this article, we review the luminosity correlations of GRBs, and implications for constraining the cosmological parameters and dark energy. Observations show that the progenitors of long GRBs are massive stars. So it is expected that long GRBs are tracers of star formation rate. We also review the high-redshift star formation rate derived from GRBs, and implications for the cosmic reionization history. The afterglows of GRBs generally have broken power-law spectra, so it...

  20. Parameter Estimation in Multivariate Gamma Distribution

    OpenAIRE

    V S Vaidyanathan; R Vani Lakshmi

    2015-01-01

    Multivariate gamma distribution finds abundant applications in stochastic modelling, hydrology and reliability. Parameter estimation in this distribution is a challenging one as it involves many parameters to be estimated simultaneously. In this paper, the form of multivariate gamma distribution proposed by Mathai and Moschopoulos [10] is considered. This form has nice properties in terms of marginal and conditional densities. A new method of estimation based on optimal search is proposed for...

  1. Ballerina - pirouettes in search of gamma bursts

    Science.gov (United States)

    Brandt, S.; Lund, N.; Pedersen, H.; Hjorth, J.; BALLERINA Collaboration

    1999-09-01

    The cosmological origin of gamma ray bursts has now been established with reasonable certainty. Many more bursts will need to be studied to establish the typical distance scale, and to map out the large diversity in properties which have been indicated by the first handful of events. We are proposing Ballerina, a small satellite to provide accurate positions and new data on the gamma-ray bursts. We anticipate a detection rate an order of magnitude larger than obtained from Beppo-SAX.

  2. Track finding in gamma conversions in CMS

    CERN Document Server

    Marinelli, Nancy

    2008-01-01

    A track finding algorithm has been developed for reconstruction of e+e- pairs. It combines the information of the electromagnetic calorimeter with the information provided by the Tracker. Results on reconstruction efficiency of converted photons, as well as on fake rate are shown for single isolated photons and for photons from H->gamma gamma events with pile-up events at 10^33 cm^-2 s^-1 LHC luminosity.

  3. Polarization measurements of proton capture gamma rays

    NARCIS (Netherlands)

    Suffert, M.; Endt, P.M.; Hoogenboom, A.M.

    1959-01-01

    The linear polarization has been measured of eight different gamma rays of widely differing energies (Eγ = 0.8 - 8.0 MeV) emitted at resonances in the 24Mg(p, γ)25Al, 30Si(p, γ)31P, and 32S(p, γ)33Cl reactions. The gamma rays emitted at 90° to the proton beam were Compton scattered in a 2″ NaI scint

  4. Latest Results from VERITAS: Gamma 2016

    CERN Document Server

    Holder, J

    2016-01-01

    The VERITAS imaging atmospheric Cherenkov telescope array has been observing the northern TeV sky with four telescopes since summer 2007. Over 50 gamma-ray sources have been studied, including active and starburst galaxies, pulsars and their nebulae, supernova remnants and Galactic binary systems. We review here some of the most recent VERITAS results, and discuss the status and prospects for collaborative work with other gamma-ray instruments, and with multimessenger observatories.

  5. Investigation of WW$\\gamma$ couplings

    CERN Document Server

    Kim, C S; Song, H S; Kim, C S; Lee, Jungil; Song, H S

    1995-01-01

    We investigated how measurements of weak boson production at high energy ep and e\\gamma collisions can provide important information on anomalous WW\\gamma couplings. We also considerd the sinlge muon production through the virtual W-decay at the Pohang Light Source (PLS) facility, and found this process is not adequate to be detected at the PLS until a large luminosity (\\sim 10^{33}/sec/cm^2) Free Electron Laser is installed.

  6. Soft gamma rays from heavy WIMPs

    Science.gov (United States)

    Krauss, Manuel Ernst; Opferkuch, Toby; Staub, Florian; Winkler, Martin Wolfgang

    2016-12-01

    We propose an explanation of the galactic center gamma ray excess by supersymmetric WIMPs as heavy as 500 GeV. The lightest neutralino annihilates into vector-like leptons or quarks which cascade decay through intermediate Higgs bosons. Due to the long decay chains, the gamma ray spectrum is much softer than naively expected and peaks at GeV energies. The model predicts correlated diboson and dijet signatures to be tested at the LHC.

  7. Two-gluon exchange contribution to elastic $\\gamma \\gamma \\to \\gamma \\gamma$ scattering and production of two-photons in ultraperipheral ultrarelativistic heavy ion and proton-proton collisions

    CERN Document Server

    Klusek-Gawenda, Mariola; Szczurek, Antoni

    2016-01-01

    We discuss the two-gluon exchange contribution (formally three-loops) to elastic photon-photon scattering in the high-energy approximation. The elastic $\\gamma\\gamma \\to \\gamma \\gamma$ amplitude is given in the impact-factor representation for all helicity configurations and finite quark masses. We discuss the importance of including the charm quark, which contribution, due to interference, can enhance the cross section considerably. We investigate the contribution to the $\\gamma \\gamma \\to \\gamma \\gamma$ amplitude from the soft region, by studying its dependence on nonperturbative gluon mass. Helicity-flip contributions are shown to be much smaller than helicity-conserving ones. We identify region(s) of phase space where the two-gluon exchange contribution becomes important ingredient compared to box and nonperturbative VDM-Regge mechanisms considered in the literature. Consequences for the $A A \\to A A \\gamma \\gamma$ reaction are discussed. Several differential distributions are shown. A feasibility study t...

  8. Nanomaterials Applied in Asphalt Modification: A Review

    Institute of Scientific and Technical Information of China (English)

    Changqing Fang; Ruien Yu; Shaolong Liu; Yan Li

    2013-01-01

    Nanotechnology has been gradually penetrated into the field of asphalt modification.Seemingly magic effects of nanomaterials have now been brought to improve the performance of asphalt.To demonstrate many of the prospective applications,researchers have conducted a series of positive and effective efforts dealing with the preparation of modified asphalt to demonstrate the mechanism of modification and the resultant improvement in performance.In this review,various nanomaterials used in asphalt modification are initially presented,followed by the methods employed to modify the asphalt with these materials and finally the effects of nanomaterials on the performance of base asphalt are presented and the modification mechanisms are discussed.Based on the current research results,the influence of preparation process parameters on the compatibility of every phase in the modified asphalt and the stability of the modified asphalt system are described.Finally,the development trend of the topic field is projected.

  9. Preventing cancer through lifestyle modification: An essential ...

    African Journals Online (AJOL)

    Preventing cancer through lifestyle modification: An essential strategy for primary ... The ten most common cancers include Cervical, Breast, Prostate, Liver, ... viral, bacterial and helminthic infections; tobacco use, poor dietary habits, obesity, ...

  10. Diagonal chromatography to study plant protein modifications

    NARCIS (Netherlands)

    Walton, Alan; Tsiatsiani, Liana; Jacques, Silke; Stes, Elisabeth; Messens, Joris; Van Breusegem, Frank; Goormachtig, Sofie; Gevaert, Kris

    2016-01-01

    An interesting asset of diagonal chromatography, which we have introduced for contemporary proteome research, is its high versatility concerning proteomic applications. Indeed, the peptide modification or sorting step that is required between consecutive peptide separations can easily be altered and

  11. Similarity Arguments in the Genetic Modification Debate

    DEFF Research Database (Denmark)

    Christiansen, Andreas

    2017-01-01

    In the ethical debate on genetic modification (GM), it is common to encounter the claim that some anti-GM argument would also apply an established, ethically accepted technology, and that the anti-GM argument is therefore unsuccessful. The paper discusses whether this argumentative strategy...... transferability of reasons from one case to another; and (iii) it runs the risk of equivocations, especially in cases where the anti-genetic-modification argument relies on gradable features. The paper then shows how these issues play out in three specific Similarity Arguments that can be found in the literature....... Finally, the paper discusses what conclusions we can draw from the fact that genetic modification and established technologies are similar for the ethical status of genetic modification....

  12. Assessment of posttranslational modification of mitochondrial proteins.

    Science.gov (United States)

    Ande, Sudharsana R; Padilla-Meier, G Pauline; Mishra, Suresh

    2015-01-01

    Mitochondria play vital roles in the maintenance of cellular homeostasis. They are a storehouse of cellular energy and antioxidative enzymes. Because of its immense role and function in the development of an organism, this organelle is required for the survival. Defects in mitochondrial proteins lead to complex mitochondrial disorders and heterogeneous diseases such as cancer, type 2 diabetes, and cardiovascular and neurodegenerative diseases. It is widely known in the literature that some of the mitochondrial proteins are regulated by posttranslational modifications. Hence, designing methods to assess these modifications in mitochondria will be an important way to study the regulatory roles of mitochondrial proteins in greater detail. In this chapter, we outlined procedures to isolate mitochondria from cells and separate the mitochondrial proteins by two-dimensional gel electrophoresis and identify the different posttranslational modifications in them by using antibodies specific to each posttranslational modification.

  13. Post-Translational Modifications of TRP Channels

    Directory of Open Access Journals (Sweden)

    Olaf Voolstra

    2014-04-01

    Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

  14. Surface Modification of Water Purification Membranes.

    Science.gov (United States)

    Miller, Daniel J; Dreyer, Daniel R; Bielawski, Christopher W; Paul, Donald R; Freeman, Benny D

    2017-04-18

    Polymeric membranes are an energy-efficient means of purifying water, but they suffer from fouling during filtration. Modification of the membrane surface is one route to mitigating membrane fouling, as it helps to maintain high levels of water productivity. Here, a series of common techniques for modification of the membrane surface are reviewed, including surface coating, grafting, and various treatment techniques such as chemical treatment, UV irradiation, and plasma treatment. Historical background on membrane development and surface modification is also provided. Finally, polydopamine, an emerging material that can be easily deposited onto a wide variety of substrates, is discussed within the context of membrane modification. A brief summary of the chemistry of polydopamine, particularly as it may pertain to membrane development, is also described. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Gamma Putty dosimetric studies in electron beam

    Science.gov (United States)

    Gloi, Aime M.

    2016-01-01

    Traditionally, lead has been used for field shaping in megavoltage electron beams in radiation therapy. In this study, we analyze the dosimetric parameters of a nontoxic, high atomic number (Z = 83), bismuth-loaded material called Gamma Putty that is malleable and can be easily molded to any desired shape. First, we placed an ionization chamber at different depths in a solid water phantom under a Gamma Putty shield of thickness (t = 0, 3, 5, 10, 15, 20, and 25 mm, respectively) and measured the ionizing radiation on the central axis (CAX) for electron beam ranging in energies from 6 to 20 MeV. Next, we investigated the relationship between the relative ionization (RI) measured at a fixed depth for several Gamma Putty shield at different cutout diameters ranging from 2 to 5 cm for various beam energies and derived an exponential fitting equation for clinical purposes. The dose profiles along the CAX show that bremsstrahlung dominates for Gamma Putty thickness >15 mm. For high-energy beams (12–20 MeV) and all Gamma Putty thicknesses up to 25 mm, RI below 5% could not be achieved due to the strong bremsstrahlung component. However, Gamma Putty is a very suitable material for reducing the transmission factor below 5% and protecting underlying normal tissues for low-energy electron beams (6–9 MeV). PMID:27651563

  16. Gamma tracking with the AGATA detector

    CERN Document Server

    Söderström, P -A; Nyberg, J; Recchia, F; Farnea, E; Gadea, A

    2008-01-01

    The next generation of radioactive ion beam facilities, which will give experimental access to many exotic nuclei, are presently being developed. At the same time the next generation of high resolution gamma-ray spectrometers, based on gamma-ray tracking, for studying the structure of these exotic nuclei are being developed. One of the main differences in tracking of $\\gamma$ rays versus charged particles is that the gamma rays do not deposit their energy "continuously" in the detector, but in a few discrete steps. Also, in the field of nuclear spectroscopy, the location of the source is mostly well known while the exact interaction position in the detector is the unknown quantity. This makes the challenges of gamma-ray tracking in germanium somewhat different compared to vertexing in silicon detectors. In these proceedings we present the methods for determining the 3D interaction positions in the detector and how these are used to reconstruct the gamma-ray tracks in the AGATA detector array. We also present ...

  17. Gamma Putty dosimetric studies in electron beam

    Directory of Open Access Journals (Sweden)

    Aime M Gloi

    2016-01-01

    Full Text Available Traditionally, lead has been used for field shaping in megavoltage electron beams in radiation therapy. In this study, we analyze the dosimetric parameters of a nontoxic, high atomic number (Z = 83, bismuth-loaded material called Gamma Putty that is malleable and can be easily molded to any desired shape. First, we placed an ionization chamber at different depths in a solid water phantom under a Gamma Putty shield of thickness (t = 0, 3, 5, 10, 15, 20, and 25 mm, respectively and measured the ionizing radiation on the central axis (CAX for electron beam ranging in energies from 6 to 20 MeV. Next, we investigated the relationship between the relative ionization (RI measured at a fixed depth for several Gamma Putty shield at different cutout diameters ranging from 2 to 5 cm for various beam energies and derived an exponential fitting equation for clinical purposes. The dose profiles along the CAX show that bremsstrahlung dominates for Gamma Putty thickness >15 mm. For high-energy beams (12-20 MeV and all Gamma Putty thicknesses up to 25 mm, RI below 5% could not be achieved due to the strong bremsstrahlung component. However, Gamma Putty is a very suitable material for reducing the transmission factor below 5% and protecting underlying normal tissues for low-energy electron beams (6-9 MeV.

  18. Hippocampal theta rhythm and its coupling with gamma oscillations require fast inhibition onto parvalbumin-positive interneurons.

    Science.gov (United States)

    Wulff, Peer; Ponomarenko, Alexey A; Bartos, Marlene; Korotkova, Tatiana M; Fuchs, Elke C; Bähner, Florian; Both, Martin; Tort, Adriano B L; Kopell, Nancy J; Wisden, William; Monyer, Hannah

    2009-03-03

    Hippocampal theta (5-10 Hz) and gamma (35-85 Hz) oscillations depend on an inhibitory network of GABAergic interneurons. However, the lack of methods for direct and cell-type-specific interference with inhibition has prevented better insights that help link synaptic and cellular properties with network function. Here, we generated genetically modified mice (PV-Deltagamma(2)) in which synaptic inhibition was ablated in parvalbumin-positive (PV+) interneurons. Hippocampal local field potential and unit recordings in the CA1 area of freely behaving mice revealed that theta rhythm was strongly reduced in these mice. The characteristic coupling of theta and gamma oscillations was strongly altered in PV-Deltagamma(2) mice more than could be accounted for by the reduction in theta rhythm only. Surprisingly, gamma oscillations were not altered. These data indicate that synaptic inhibition onto PV+ interneurons is indispensable for theta- and its coupling to gamma oscillations but not for rhythmic gamma-activity in the hippocampus. Similar alterations in rhythmic activity were obtained in a computational hippocampal network model mimicking the genetic modification, suggesting that intrahippocampal networks might contribute to these effects.

  19. A Study of Optimization of Alpha-Beta-Gamma-Eta Filter for Tracking a High Dynamic Target

    Directory of Open Access Journals (Sweden)

    Tae-Gweon Jeong

    2017-03-01

    Full Text Available The tracking filter plays a key role in accurate estimation and prediction of maneuvering vessel’s position and velocity. Different methods are used for tracking. However, the most commonly used method is the Kalman filter and its modifications. The Alpha-Beta-Gamma filter is one of the special cases of the general solution pro-vided by the Kalman filter. It is a third order filter that computes the smoothed estimates of position, velocity and acceleration for the nth observation, and also predicts the next position and velocity. Although found to track a maneuvering target with a good accuracy than the constant velocity, Alpha-Beta filter, the Alpha-Beta-Gamma filter does not perform impressively under high maneuvers such as when the target is undergoing changing accelerations. This study, therefore, aims to track a highly maneuvering target experiencing jerky motions due to changing accelerations. The Alpha-Beta-Gamma filter is extended to include the fourth state that is, constant jerk to correct the sudden change of acceleration in order to improve the filter’s performance. Results obtained from simulations of the input model of the target dynamics under consideration indicate an improvement in performance of the jerky model, Alpha-Beta-Gamma-Eta, algorithm as compared to the constant acceleration model, Alpha-Beta-Gamma in terms of error reduction and stability of the filter during target maneuver.

  20. Covalent Surface Modifications of Carbon Nanotubes.

    Energy Technology Data Exchange (ETDEWEB)

    Pavia Sanders, Adriana [Sandia National Lab. (SNL-CA), Livermore, CA (United States); O' Bryan, Greg [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-07-01

    A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

  1. DNA Methylation: Bisulphite Modification and Analysis

    OpenAIRE

    Patterson, Kate; Molloy, Laura; Qu, Wenjia; Clark, Susan

    2011-01-01

    Epigenetics describes the heritable changes in gene function that occur independently to the DNA sequence. The molecular basis of epigenetic gene regulation is complex, but essentially involves modifications to the DNA itself or the proteins with which DNA associates. The predominant epigenetic modification of DNA in mammalian genomes is methylation of cytosine nucleotides (5-MeC). DNA methylation provides instruction to gene expression machinery as to where and when the gene should be expres...

  2. Molecular recognition of nitrated fatty acids by PPAR[gamma

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yong; Zhang, Jifeng; Schopfer, Francisco J.; Martynowski, Dariusz; Garcia-Barrio, Minerva T.; Kovach, Amanda; Suino-Powell, Kelly; Baker, Paul R.S.; Freeman, Bruce A.; Chen, Y. Eugene; Xu, H. Eric (Pitt); (Michigan); (Van Andel); (Morehouse-MED)

    2010-03-08

    Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.

  3. Recombinant mouse interferon-gamma regulation of antibody production.

    OpenAIRE

    1983-01-01

    Interferon-gamma produced in monkey cells by transfection with mouse interferon-gamma cDNA suppressed the mouse in vitro antibody response in a manner similar to that of natural mouse interferon-gamma. Significant suppression was obtained with as little as 1 U of interferon. Recombinant human interferon-gamma produced by cloning in a similar fashion was not suppressive. Both the suppressive and the antiviral activities of recombinant interferon-gamma were neutralized by antibodies to mouse na...

  4. Post-translational modifications in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Federico Benetti

    2015-12-01

    Full Text Available Post-translational modifications increase proteome functionality for managing all aspects of normal cell biology. They are based on the covalent attachment of functional groups, leading to phosphorylation, acetylation, glycosylation, acylation, ubiquitination, SUMOylation and oxidation of protein targets. Post-translational modifications occur at any step of protein life cycle, modulating in time and space protein folding, subcellular localization and activity. Aberrant post-translational modifications of one or more culprit proteins may lead to neurodegeneration, as shown in paradigmatic neurological disorders such as Alzheimer’s, Parkinson’s and prion diseases. In this review, we report the most important post-translational modifications found in neurodegenerative disorders, illustrating the pathophysiological mechanisms in which they are involved. This work highlights the lack of a global framework of post-translational modifications in terms of complexity and regulation. Therefore, in the next future many efforts are required to describe the interplay existing between post-translational modifications and their combinatorial patterns on protein targets.

  5. Search for Charmonium States Decaying to J/psi gamma gamma Using Initial-State Radiation Events

    CERN Document Server

    Aubert, B; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo-Sánchez, P; Barrett, M; Ford, K E; Hart, A J; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, Y K; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H; al, et

    2006-01-01

    We study the processes e+e- -> (J/psi gamma gamma) gamma and e+e- -> (J/psi pi- pi+) gamma where the hard photon radiated from an initial e+e- collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/psi gamma gamma we consider J/psi pi0, J/psi eta, chi_{c1} gamma, and chi_{c2} gamma candidates. The invariant mass of the hadronic final state defines the effective e+e- CM energy in each event, so these data can be compared with direct e+e- measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/psi gamma gamma channels in the Y(4260) mass region.

  6. Dark Matter versus h into gamma gamma and h into gamma Z with supersymmetric triplets

    CERN Document Server

    Arina, Chiara; Nardini, Germano

    2014-01-01

    The Triplet extension of the MSSM (TMSSM) alleviates the little hierarchy problem and provides a significant enhancement of the loop-induced diphoton rate of the lightest CP-even Higgs h. In this paper we pursue the analysis of the TMSSM Higgs phenomenology by computing for the first time the h into Z + gamma decay. Interestingly we find that the rates of loop-induced decays are correlated and their signal strengths can rise up to 40% - 60% depending on the channel. We furthermore study the dark matter phenomenology of the TMSSM. The lightest neutralino is a good dark matter candidate in two regions. The first one is related to the Higgs and Z resonances and the LSP is mostly Bino. The second one is achieved for a mass larger than 90 GeV and the LSP behaves as the well-tempered neutralino. An advantage of the triplet contribution is that the well-tempered neutralino can be a Bino-Triplino mixture, relieving the problem of achieving M_2 ~ M_1 in unified scenarios. The dark matter constraints strongly affect th...

  7. Supernovae and Gamma-Ray Bursts

    Science.gov (United States)

    Livio, Mario; Panagia, Nino; Sahu, Kailash

    2001-07-01

    Participants; Preface; Gamma-ray burst-supernova relation B. Paczynski; Observations of gamma-ray bursts G. Fishman; Fireballs T. Piran; Gamma-ray mechanisms M. Rees; Prompt optical emission from gamma-ray bursts R. Kehoe, C. Akerlof, R. Balsano, S. Barthelmy, J. Bloch, P. Butterworth, D. Casperson, T. Cline, S. Fletcher, F. Frontera, G. Gisler, J. Heise, J. Hills, K. Hurley, B. Lee, S. Marshall, T. McKay, A. Pawl, L. Piro, B. Priedhorsky, J. Szymanski and J. Wren; X-ray afterglows of gamma-ray bursts L. Piro; The first year of optical-IR observations of SN1998bw I. Danziger, T. Augusteijn, J. Brewer, E. Cappellaro, V. Doublier, T. Galama, J. Gonzalez, O. Hainaut, B. Leibundgut, C. Lidman, P. Mazzali, K. Nomoto, F. Patat, J. Spyromilio, M. Turatto, J. Van Paradijs, P. Vreeswijk and J. Walsh; X-ray emission of Supernova 1998bw in the error box of GRB980425 E. Pian; Direct analysis of spectra of type Ic supernovae D. Branch; The interaction of supernovae and gamma-ray bursts with their surroundings R. Chevalier; Magnetars, soft gamma-ray repeaters and gamma-ray bursts A. Harding; Super-luminous supernova remnants Y. -H. Chu, C. -H. Chen and S. -P. Lai; The properties of hypernovae: SNe Ic 1998bw, 1997ef, and SN IIn 1997cy K. Nomoto, P. Mazzali, T. Nakamura, K. Iwanmoto, K. Maeda, T. Suzuki, M. Turatto, I. Danziger and F. Patat; Collapsars, Gamma-Ray Bursts, and Supernovae S. Woosley, A. MacFadyen and A. Heger; Pre-supernova evolution of massive stars N. Panagia and G. Bono; Radio supernovae and GRB 980425 K. Weiler, N. Panagia, R. Sramek, S. Van Dyk, M. Montes and C. Lacey; Models for Ia supernovae and evolutionary effects P. Hoflich and I. Dominguez; Deflagration to detonation A. Khokhlov; Universality in SN Iae and the Phillips relation D. Arnett; Abundances from supernovae F. -K. Thielemann, F. Brachwitz, C. Freiburghaus, S. Rosswog, K. Iwamoto, T. Nakamura, K. Nomoto, H. Umeda, K. Langanke, G. Martinez-Pinedo, D. Dean, W. Hix and M. Strayer; Sne, GRBs, and the

  8. Gravitational Gamma Spectrometer for Studying the Gamma Resonance of the Long-Lived Isomer 103mRh

    CERN Document Server

    Davydov, A V; Kalantarov, V D; Korotkov, M M; Migachev, V V; Novozhilov, Yu B; Stepanov, A M

    2015-01-01

    The principle of operation and the construction are described of the gravitational gamma spectrometer to study the gamma resonance of the long-lived isomer $^{103m}$Rh. This is a table-top device which measures the form of gamma resonance by the dependence of counting rate of gamma-rays in collimated beams on the angle of their inclination with respect of the horizontal plane. Methods of fabrication of gamma-sources for this device are considered.

  9. Measurement of $\\Gamma(\\eta \\to \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta \\to \\pi^+\\pi^-\\pi^0)$ with KLOE experiment

    CERN Document Server

    Ambrosino, F.; Antonelli, M.; Archilli, F.; Balwierz, I.; Bencivenni, G.; Bini, C.; Bloise, C.; Bocchetta, S.; Bossi, F.; Branchini, P.; Capon, G.; Capussela, T.; Ceradini, F.; Ciambrone, P.; Czerwiński, E.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Jacewicz, M.; Lee-Franzini, J.; Martemianov, M.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Morello, G.; Moulson, M.; Müller, S.; Napolitano, M.; Nguyen, F.; Palutan, M.; Passeri, A.; Patera, V.; Prado Longhi, I.; Santangelo, P.; Sciascia, B.; Silarski, M.; Spadaro, T.; Taccini, C.; Tortora, L.; Venanzoni, G.; Versaci, R.; Xu, G.; Zdebik, J.; Babusci, D.; Badoni, D.; Bocci, V.; Budano, A.; Bulychjev, S.A.; Campana, P.; Dané, E.; De Robertis, G.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Gonnella, F.; Happacher, F.; Höistad, B.; Iarocci, E.; Johansson, T.; Kulikov, V.; Kupsc, A.; Loddo, F.; Matsyuk, M.; Messi, R.; Moricciani, D.; Moskal, P.; Ranieri, A.; Sarra, I.; Schioppa, M.; Sciubba, A.; Wiślicki, W.; Wolke, M.

    2011-01-01

    We report the measurement of the ratio $\\Gamma(\\eta \\to \\pi^+\\pi^-\\gamma)/\\Gamma(\\eta \\to \\pi^+\\pi^-\\pi^0)$ analyzing a large sample of $\\phi \\to \\eta \\gamma$ decays recorded with the KLOE experiment at the DA$\\Phi$NE $e^+ e^-$ collider, corresponding to an integrated luminosity of 558 pb$^{-1}$. The $\\eta \\to \\pi^+\\pi^-\\gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $\\rho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Our result $R_{\\eta}=\\Gamma(\\eta \\to \\pi^+ \\pi^- \\gamma)/\\Gamma(\\eta \\to \\pi^+ \\pi^- \\pi^0)= 0.1838\\pm 0.0005_{stat} \\pm 0.0030_{syst}$ is in agreement with a recent CLEO measurement, which differs by more 3 $\\sigma$ from the average of previous results.

  10. Measurement of the Branching Ratio Gamma(D_s^* -> D_s pi0)/Gamma(D_s^* --> D_s gamma)

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Nesom, G; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Fabozzi, F; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2004-01-01

    The (Delta I = 1) decay D_s^* --> Ds pi0 and (\\Delta I = 0) decay D_s^* --> Ds gamma have been reconstructed using 90.4 fb^-1 of data recorded by the BaBar detector at the PEP-II asymmetric-energy e^+e^- collider. The relative branching fraction of isospin violating decay to isospin conserving decay has been measured. Our preliminary result for this ratio is Gamma(D_s^* -> D_s pi0)/Gamma(D_s^* --> D_s gamma) = 0.0621 +/- 0.0049 (stat) +/- 0.0063 (syst). In addition we reconstruct the decays D^* --> D0 pi0 and D^* --> D0 gamma for completeness and measure a preliminary relative branching fraction to be Gamma(D^* --> D0 pi0)/Gamma(D&* --> D0 gamma) = = 1.740 +/- 0.020 (stat) +/- 0.125 (syst). Both measurements represent significant improvements over present world averages.

  11. On the difference between gamma-ray-detected and non-gamma-ray-detected pulsars

    CERN Document Server

    Rookyard, Simon C; Johnston, Simon; Kerr, Matthew

    2016-01-01

    We compare radio profile widths of young, energetic gamma-ray-detected and non-gamma-ray-detected pulsars. We find that the latter typically have wider radio profiles, with the boundary between the two samples exhibiting a dependence on the rate of rotational energy loss. We also find that within the sample of gamma-ray-detected pulsars, radio profile width is correlated with both the separation of the main gamma-ray peaks and the presence of narrow gamma-ray components. These findings lead us to propose that these pulsars form a single population where the main factors determining gamma ray detectability are the rate of rotational energy loss and the proximity of the line of sight to the rotation axis. The expected magnetic inclination angle distribution will be different for radio pulsars with and without detectable gamma rays, naturally leading to the observed differences. Our results also suggest that the geometry of existing radio and outer-magnetosphere gamma-ray emission models are at least qualitative...

  12. High resolution {gamma} per-operative imaging; Imagerie {gamma} per-operatoire

    Energy Technology Data Exchange (ETDEWEB)

    Charon, Y.; Cohen-Solal, M.; Menard, L.; Laniece, P.; Mastrippolito, R.; Ploux, L.; Valentin, L. [Groupe I.P.B., Experimental Research Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1999-11-01

    The development of hand-held {gamma} imaging probe, for inside body localization of small tumors, is of first interest for radio-guided operative cancer surgery. In that context, we have developed a sub-millimeter spatial resolution, small field of view, {gamma} per-operative compact imager (POCI). (authors)

  13. Searches for ttH and tH with H \\rightarrow \\gamma \\gamma

    CERN Document Server

    Cinca, Diane; The ATLAS collaboration

    2016-01-01

    Presentation of the latest results concerning ttH with Higgs decaying to gamma gamma for 13 TeV data. Results are from both ATLAS and CMS. The talk is planned for Top2016, September 19-23, in Olomouc.

  14. The Z-> gamma gamma,gg decays in the non-commutative standard model

    CERN Document Server

    Behr, W; Duplancic, G; Schupp, P; Trampetic, J; Wess, J

    2003-01-01

    On non-commutative spacetime, the standard model (SM) allows new, usually SM forbidden, triple gauge boson interactions to occur. In this letter we propose the SM strictly forbidden Z-> gamma gamma and Z->gg decay modes coming from the gauge sector of the non-commutative standard model (NCSM) as a place where non-commutativity could be experimentally discovered. (orig.)

  15. Structure of the human G gamma-A gamma-delta-beta-globin gene locus

    NARCIS (Netherlands)

    Bernards, R.A.; Little, P.F.R.; Annison, F.; Williamson, R.; Flavell, R.A.

    1979-01-01

    We have constructed a physical map of the human G gamma-, A gamma-, delta-, and beta-globin genes. The previously described maps of the fetal and adult beta-like globin genes have been linked to one another by identification of a DNA fragment, generated by BamHI, that contains part of each of the A

  16. Higgs, SUSY and the Standard Model at $\\gamma\\gamma$ Colliders

    CERN Document Server

    Hagiwara, K

    2001-01-01

    In this report I surveyed physics potential of the gamma-gamma option of a Linear e+e- Collider with the following questions in mind: What new discovery can be expected at a gamma-gamma collider in addition to what will be learned at its `parent' e+e- Linear Collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e- beams, we find that a gamma-gamma collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e-e- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a gamma-gamma collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay angular correlations of final state particles, and the pattern of ...

  17. Consequences of the gamma-gamma attenuation in GRBs: a detailed study

    CERN Document Server

    Hascoët, R; Mochkovitch, R; Vennin, V

    2011-01-01

    Recent detections of GeV photons in a few GRBs by Fermi-LAT have led to strong constraints on the bulk Lorentz factor in GRB outflows. To avoid a large gamma-gamma optical depth, minimum values of the Lorentz factor have been estimated to be as high as 800-1200 in some bursts. Here we present a detailed calculation of the gamma-gamma optical depth taking into account both the geometry and the dynamics of the jet. In the framework of the internal shock model, we compute lightcurves in different energy bands and the corresponding spectrum and we show how the limits on the Lorentz factor can be significantly lowered compared to previous estimates. Our detailed model of the propagation of high energy photons in GRB outflows is also appropriate to study many other consequences of gamma-gamma annihilation in GRBs: (i) the gamma-gamma cutoff transition in a time-integrated spectrum is expected to be closer to a power-law steepening of the spectrum than to a sharp exponential decay; (ii) the temporal evolution of the...

  18. Gravitational Light Bending Prevents $\\gamma\\gamma$ Absorption in Gravitational Lenses

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The magnification effect due to gravitational lensing enhances the chances of detecting moderate-redshift ($z \\sim 1$) sources in very-high-energy (VHE; $E > 100$ GeV) $\\gamma$-rays by ground-based Atmospheric Cherenkov Telescope facilities. It has been shown in previous work that this prospect is not hampered by potential $\\gamma-\\gamma$ absorption effects by the intervening (lensing) galaxy, nor by any individual star within the intervening galaxy. In this paper, we expand this study to simulate the light-bending effect of a realistic ensemble of stars. We first demonstrate that, for realistic parameters of the galaxy's star field, it is extremely unlikely (probability $\\lesssim 10^{-6}$) that the direct line of sight between the $\\gamma$-ray source and the observer passes by any star in the field close enough to be subject to significant $\\gamma\\gamma$ absorption. Our simulations then focus on the rare cases where $\\gamma\\gamma$ absorption by (at least) one individual star might be non-negligible. We show ...

  19. Development of a Second Generation Bovigam Interferon Gamma (IFN-gamma) Assay

    Science.gov (United States)

    In search for better tools to control bovine tuberculosis, the development of diagnostic tests with improved performance and enhanced ease-of-use has a high priority. BOVIGAM®, a rapid laboratory assay, measures gamma interferon (IFN-gamma) production in whole blood samples after induction of a ce...

  20. Effective action for. omega. -> 3. pi. ,. omega. ->. pi gamma. and rho ->. pi gamma

    Energy Technology Data Exchange (ETDEWEB)

    Golterman, M.F.L.

    1988-10-31

    It is argued that the decay widths for ..omega.. -> 3..pi.., ..omega.. -> ..pi gamma.. and rho -> ..pi gamma.. do not follow from the gauged Wess-Zumino-Witten action. An alternative effective action for these decays is constructed and its parameters are fitted to the experimental values of the widths.

  1. Study of the hadronic $\\gamma\\gamma$ interactions at $\\sqrt{s}$ = 200 GeV

    CERN Document Server

    Alderweireld, T; Verdier, P

    2000-01-01

    A comparison between real data and Monte Carlo is presented, based on a data sample corresponding to the 84.3 pb-1 recorded by the DELPHI detector in 1999, at centre-of-mass energy of 200 GeV. Two hadronic gamma gamma generators have been used for this present analysis, TWOGAM 2.04 and PYTHIA 6.143.

  2. Higgs Boson Self-Coupling at High Energy $\\gamma \\gamma$ Collider

    CERN Document Server

    Gutierrez-Rodriguez, A; Sampayo, O A

    2011-01-01

    We analyzed the double production and the triple self-coupling of the standard model Higgs boson at future $\\gamma \\gamma$ collider energies, with the reactions $\\gamma\\gamma \\rightarrow f \\bar f HH$ $(f=b, t)$. We evaluated the total cross section for $f\\bar fHH$ and calculated the total number of events considering the complete set of Feynman diagrams at tree-level and for different values of the triple coupling $\\kappa\\lambda_{HHH}$. We have also analyzed the sensitivity for the considered reaction and we show the results as 95% C.L. regions in the $\\kappa-M_H$ plane for different values of the center of mass energy and different levels of background. The numerical computation was done for the energies which are expected to be available at a possible Future Linear $\\gamma\\gamma$ Collider with a center-of-mass energy 500-3000 $GeV$ and luminosities of 1 and $5 ab^{-1}$. We found that the number of events for the process $\\gamma\\gamma \\rightarrow t \\bar t HH$, taking into account the decay products of both $...

  3. Single Higgs-boson production through gamma-gamma scattering within the general 2HDM

    CERN Document Server

    Bernal, Nicolas; Sola, Joan

    2009-01-01

    The production of a single neutral Higgs boson h through (loop-induced) gamma-gamma collisions is explored in the context of the linear colliders within the general Two-Higgs-Doublet Model (2HDM). Two different mechanisms are analyzed: on the one hand, the scattering gamma gamma-> h of two real photons in a gamma-gamma collider; on the other, the more traditional mechanism of virtual photon fusion, e+e- -->e+e- + h. Owing to the peculiar properties of the Higgs boson self-interactions within the general 2HDM, we find that the overall production rates can be boosted up significantly, provided the charged Higgs mass is not too heavy. For example, if the latter is slightly above 100 GeV and, in addition, the lightest CP-even Higgs boson falls in the ballpark of the LEP bound on the SM Higgs mass up to a few hundred GeV, the cross-sections may typically render \\sigma(gamma gamma-> h)= 0.1-1 pb and \\sigma(e+e- --> e+e- + h)\\sim 0.01 pb -- in both cases well above the SM prediction. Although for charged Higgs masse...

  4. Perspectives of the GAMMA-400 space observatory for high-energy gamma rays and cosmic rays measurements

    Science.gov (United States)

    Topchiev, N. P.; Galper, A. M.; Bonvicini, V.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Bakaldin, A. V.; Bergstrom, L.; Berti, E.; Bigongiari, G.; Bobkov, S. G.; Boezio, M.; Bogomolov, E. A.; Bonechi, S.; Bongi, M.; Bottai, S.; Castellini, G.; Cattaneo, P. W.; Cumani, P.; Dalkarov, O. D.; Dedenko, G. L.; De Donato, C.; Dogiel, V. A.; Finetti, N.; Gorbunov, M. S.; Gusakov, Yu V.; Hnatyk, B. I.; Kadilin, V. V.; Kaplin, V. A.; Kaplun, A. A.; Kheymits, M. D.; Korepanov, V. E.; Larsson, J.; Leonov, A. A.; Loginov, V. A.; Longo, F.; Maestro, P.; Marrocchesi, P. S.; Men'shenin, A. L.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu; Papini, P.; Pearce, M.; Picozza, P.; Rappoldi, A.; Ricciarini, S.; Runtso, M. F.; Ryde, F.; Serdin, O. V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu I.; Suchkov, S. I.; Taraskin, A. A.; Tavani, M.; Tiberio, A.; Tyurin, E. M.; Ulanov, M. V.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Yurkin, Yu T.; Zampa, N.; Zirakashvili, V. N.; Zverev, V. G.

    2016-02-01

    The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma-rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern the following scientific tasks: investigation of point sources of gamma-rays, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the Sun, as well as high precision measurements of spectra of high-energy electrons and positrons. Also the GAMMA- 400 instrument provides the possibility for protons and nuclei measurements up to knee. But the main goal for the GAMMA-400 mission is to perform a sensitive search for signatures of dark matter particles in high-energy gamma-ray emission. To fulfill these measurements the GAMMA-400 gamma-ray telescope possesses unique physical characteristics in comparison with previous and present experiments. The major advantage of the GAMMA-400 instrument is excellent angular and energy resolution for gamma-rays above 10 GeV. The GAMMA-400 experiment will be installed onboard of the Navigator space platform, manufactured by the NPO Lavochkin Association. The expected orbit will be a highly elliptical orbit (with apogee 300.000 km and perigee 500 km) with 7 days orbital period. An important profit of such an orbit is the fact that the full sky coverage will always be available for gamma ray astronomy.

  5. New insights from cosmic gamma rays

    Science.gov (United States)

    Roland, Diehl

    2016-04-01

    The measurement of gamma rays from cosmic sources at ~MeV energies is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and their impacts on objects and phenomena throughout the universe. Gamma rays trace nuclear processes most directly, as they originate from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. Additionally, the unique gamma-ray signature from the annihilation of positrons falls into this astronomical window and is discussed here: Cosmic positrons are often produced from β-decays, thus also of nuclear physics origins. The nuclear reactions leading to radioactive isotopes occur inside stars and stellar explosions, which therefore constitute the main objects of such studies. In recent years, both thermonuclear and core-collapse supernova radioactivities have been measured though 56Ni, 56Co, and 44Ti lines, and a beginning has thus been made to complement conventional supernova observations with such measurements of the prime energy sources of supernova light created in their deep interiors. The diffuse radioactive afterglow of massive-star nucleosynthesis in gamma rays is now being exploited towards astrophysical studies on how massive stars feed back their energy and ejecta into interstellar gas, as part of the cosmic cycle of matter through generations of stars enriching the interstellar gas and stars with metals. Large interstellar cavities and superbubbles have been recognised to be the dominating structures where new massive-star ejecta are injected, from 26Al gamma-ray spectroscopy. Also, constraints on the complex interiors of stars derive from the ratio of 60Fe/26Al gamma rays. Finally, the puzzling bulge-dominated intensity distribution of positron annihilation gamma rays is measured in greater detail, but still not understood; a recent microquasar flare provided evidence that such objects may be prime sources for positrons in interstellar space, rather than

  6. Neutron and Gamma-ray Measurements

    Science.gov (United States)

    Krasilnikov, Anatoly V.; Sasao, Mamiko; Kaschuck, Yuri A.; Kiptily, Vasily G.; Nishitani, Takeo; Popovichev, Sergey V.; Bertalot, Luciano

    2008-03-01

    Due to high neutron and gamma-ray yields and large size plasmas many future fusion reactor plasma parameters such as fusion power, fusion power density, ion temperature, fuel mixture, fast ion energy and spatial distributions can be well measured by various fusion product diagnostics. Neutron diagnostics provide information on fusion reaction rate, which indicates how close is the plasma to the ultimate goal of nuclear fusion and fusion power distribution in the plasma core, which is crucial for optimization of plasma breakeven and burn. Depending on the plasma conditions neutron and gamma-ray diagnostics can provide important information, namely about dynamics of fast ion energy and spatial distributions during neutral beam injection, ion cyclotron heating and generated by fast ions MHD instabilities. The influence of the fast particle population on the 2-D neutron source profile was clearly demonstrated in JET experiments. 2-D neutron and gamma-ray source measurements could be important for driven plasma heating profile optimization in fusion reactors. To meat the measurement requirements in ITER the planned set of neutron and gamma ray diagnostics includes radial and vertical neutron and gamma cameras, neutron flux monitors, neutron activation systems and neutron spectrometers. The necessity of using massive radiation shielding strongly influences the diagnostic designs in fusion reactor, determines angular fields of view of neutron and gamma-ray cameras and spectrometers and gives rise to unavoidable difficulties in the absolute calibration. The development, testing in existing tokomaks and a possible engineering integration of neuron and gamma-ray diagnostic systems into ITER are presented.

  7. Gamma Astrometric Measurement Experiment (GAME) - Science case

    Science.gov (United States)

    Vecchiato, Alberto; Gai, Mario; Lattanzi, Mario G.; Crosta, Maria Teresa; Sozzetti, Alessandro

    GAME (Gamma Astrometric Measurement Experiment) is a concept for a small mission whose main goal is to measure from space the γ parameter of the Parameterized Post-Newtonian formalism. A satellite looking as close as possible to the Solar limb implements a technique similar to that used during the solar eclipse of 1919, when Dyson, Eddington and collaborators measured for the first time the gravitational bending of light. Preliminary simulations have shown that the expected final accuracy can reach the 10-7 level or better. This makes GAME a decisive experiment for the understanding of gravity physics, cosmology and the Universe evolution at a fundamental level. During the last decade, in fact, a strong experimental evidence of an acceleration of the expansion of the Universe at the present time has been provided by several observational data. This has been interpreted as the effect of a long range perturbation of the gravity field of the visible matter generated by the so-called Dark Energy. These data add to those available for long time at different scale length, which are explained with the existence of non-barionic Dark Matter (e.g. galaxy rotation curves) or with some kind of modification of the General Relativity theory (e.g. Pioneer anomalies). However, there are claims that these data can be explained with a modified version of General Relativity, in which the curvature invariant R is no longer constant in the Einstein equations (f (R) gravity theories). Present experimental data are not accurate enough to discriminate between these scenarios, but this could be done with a 10-7 -level measure of γ. Moreover, the limited fraction of time needed for the main experiment with respect to the overall mission duration opens interesting possibilities for other kinds of measurements. One is to measure the light deflection induced by the quadrupole moment of giant planets like Jupiter or Saturn, an effect predicted by General Relativity but never measured up to

  8. Gamma-Ray Lenses for Astrophysics-and the Gamma-Ray Imager Mission GRI

    DEFF Research Database (Denmark)

    Wunderer, C. B.; Ballmoos, P. V.; Barriere, N.

    2009-01-01

    Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles...... are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are major science themes that are addressed in the gamma-ray regime. While Fermi will take......, albeit at much more modest sensitivities. There will be clearly a growing need to perform deeper, more focused investigations of gamma-ray sources in the 100-keV to MeV regime. Recent technological advances in the domain of gamma-ray focusing using Lane diffraction and multilayer-coated mirror techniques...

  9. The Infrared-Gamma-Ray Connection: A WISE View of the Extragalactic Gamma-Ray Sky

    CERN Document Server

    Massaro, F

    2016-01-01

    Using data from the WISE all-sky survey we discovered that the non-thermal infrared (IR) emission of blazars, the largest known population of extragalactic gamma-ray sources, has peculiar spectral properties. In this work, we confirm and strengthen our previous analyses using the latest available releases of both the WISE and the Fermi source catalogs. We also show that there is a tight correlation between the mid-IR colors and the gamma-ray spectral index of Fermi blazars. We name this correlation "the infrared--gamma-ray connection". We discuss how this connection links both the emitted powers and the spectral shapes of particles accelerated in jets arising from blazars over ten decades in energy. Based on this evidence, we argue that the infrared--gamma-ray connection is stronger than the well known radio--gamma-ray connection.

  10. Gamma-Ray Pulsars Expected in the Outer Gap Model of Gamma-Ray Emission

    Institute of Scientific and Technical Information of China (English)

    张力; 吴杰; 姜泽军; 梅冬成

    2003-01-01

    We study the possibility of high-energy gamma-ray emission from the known 1130 radio pulsars based on the outer gap model of high-energy emission from pulsars. We estimate the fractional size of outer gap, the integrated flux, the gamma-ray luminosity for each known radio pulsar, and find that only 14% of the known radio pulsars are gamma-ray emitters according to the outer gap model. In the sample of possible 156 gamma-ray pulsars, our statistical analysis indicates that the distributions of the spin-down powers and the ages of these pulsars concentrate mainly on 1033.5-1039 erg/s and 103-107 y, respectively. The predictions of gamma-ray pulsars detected by the AGILE and GLAST missions are given.

  11. Gamma response study of radiation sensitive MOSFETs for their use as gamma radiation sensor

    Science.gov (United States)

    Srivastava, Saurabh; Aggarwal, Bharti; Singh, Arvind; Kumar, A. Vinod; Topkar, Anita

    2016-05-01

    Continuous monitoring of gamma dose is important in various fields like radiation therapy, space-related research, nuclear energy programs and high energy physics experiment facilities. The present work is focused on utilization of radiation-sensitive Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) to monitor gamma radiation doses. Static characterization of these detectors was performed to check their expected current-voltage relationship. Threshold voltage and transconductance per unit gate to source voltage (K factor) were calculated from the experimental data. The detector was exposed to gamma radiation in both, with and without gate bias voltage conditions, and change in threshold voltage was monitored at different gamma doses. The experimental data was fitted to obtain equation for dependence of threshold voltage on gamma dose. More than ten times increase in sensitivity was observed in biased condition (+3 V) compared to the unbiased case.

  12. Enhancement of $h \\to \\gamma \\gamma$ by seesaw-motivated exotic scalars

    CERN Document Server

    Picek, Ivica

    2012-01-01

    We examine the role of seesaw motivated exotic scalars in loop-mediated Higgs decays. We consider a simple TeV-scale seesaw model built upon the fermionic quintuplet mediator in conjunction with the scalar quadruplet, where we examine portions of the model parameter space for which the contributions of charged components of the scalar quadruplet significantly increase the $h \\to \\gamma \\gamma$ decay rate. The most significant change in the diphoton width comes from a doubly charged scalar \\Phi^{--} which should be the lightest component in the scalar quadruplet. There is a mild suppression of the $h \\to Z \\gamma$ decay width by a factor 0.9 -- 0.7 in the part of the parameter space where the $h \\to \\gamma \\gamma$ decay width is enhanced by a factor 1.25 -- 2.

  13. Measurement of K{sup {+-}}{yields}{pi}{sup {+-}}{gamma}{gamma} decays

    Energy Technology Data Exchange (ETDEWEB)

    Morales Morales, Cristina

    2009-07-21

    The goal of this thesis was an experimental test of an effective theory of strong interactions at low energy, called Chiral Perturbation Theory (ChPT). Weak decays of kaon mesons provide such a test. In particular, K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays are interesting because there is no tree-level O(p{sup 2}) contribution in ChPT, and the leading contributions start at O(p{sup 4}). At this order, these decays include one undetermined coupling constant, c. Both the branching ratio and the spectrum shape of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays are sensitive to this parameter. O(p{sup 6}) contributions to K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} ChPT predict a 30-40% increase in the branching ratio. From the measurement of the branching ratio and spectrum shape of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} decays, it is possible to determine a model dependent value of c and also to examine whether the O(p{sup 6}) corrections are necessary and enough to explain the rate. About 40% of the data collected in the year 2003 by the NA48/2 experiment have been analyzed and 908 K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} candidates with about 8% background contamination have been selected in the region with z=m{sup 2}{sub {gamma}}{sub {gamma}}/m{sub K}{sup 2}{>=}0.2. Using 5,750,121 selected K{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup 0} decays as normalization channel, a model independent differential branching ratio of K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma} has been measured to be: BR(K{sup {+-}} {yields} {pi}{sup {+-}}{gamma}{gamma}, z{>=}0.2)=(1.018{+-}0.038{sub stat}{+-}0.039{sub syst}{+-}0.004{sub ext}).10{sup -6}. From the fit to the O(p{sup 6}) ChPT prediction of the measured branching ratio and the shape of the z-spectrum, a value of c=1.54{+-}0.15{sub stat}{+-}0.18{sub syst} has been extracted. Using the measured c value and the O(p{sup 6}) ChPT prediction, the branching ratio for z=m{sup 2}{sub

  14. Effect of gamma irradiation on the change of solubility and anti-inflammation activity of chrysin in macrophage cells and LPS-injected endotoxemic mice

    Science.gov (United States)

    Byun, Eui-Baek; Jang, Beom-Su; Byun, Eui-Hong; Sung, Nak-Yun

    2016-10-01

    This study evaluated the changes of solubility and anti-inflammatory properties of structurally modified gamma-irradiated chrysin. Chrysin was irradiated at various doses for a physical analysis and determining any structural changes and solubility. As shown through the physical analysis, the main peak of the chrysin was decreased as the irradiation dose increased, and it was concomitant with the appearance of several new peaks, which were highly increased in 50 kGy gamma-irradiated chrysin. The solubility was markedly increased in the gamma-irradiated groups. As shown through a physiological analysis, both gamma-irradiated- (15-50 kGy) and intact-chrysin (0 kGy) did not exert cytotoxicity to bone-marrow derived macrophages. The treatment of LPS-stimulated macrophages with 50 kGy gamma-irradiated chrysin resulted in a dose-dependent decrease in pro-inflammatory mediators, such as iNOS-mediated NO, PGE2, COX-2, and cell surface marker (CD80 and CD86), as well as pro-inflammatory cytokines (TNF-α and IL-6), when compared to the intact-chrysin treated group. Mechanically, we found that the inhibition of these pro-inflammatory mediators induced by gamma-irradiated chrysin occurred through an inhibition of MAPKs (ERK1/2 and p38) and the NF-κB signaling pathways. Furthermore, the anti-inflammatory activity remained in the LPS-injected animal model. In this model, gamma-irradiated chrysin treatment highly increased the mouse survival, and significantly decreased the serum cytokine (TNF-α, IL-6 and IL-1β) levels. From these findings, the anti-inflammatory action by gamma-irradiated chrysin may be closely mediated with structural modification. It seems likely that gamma irradiation can be an effective tool for improvement of the physical and physiological properties of polyphenols.

  15. Evaluation of gamma interferon (IFN-gamma)-induced protein 10 (IP-10) responses for detection of cattle infected with Mycobacterium bovis: comparisons to IFN-gamma responses

    Science.gov (United States)

    Gamma interferon (IFN-gamma)-induced protein 10 (IP-10) has recently shown promise as a diagnostic biomarker of Mycobacterium tuberculosis infection of humans. The aim of the current study was to compare IP-10 and IFN-gamma responses upon Mycobacterium bovis infection in cattle using archived sample...

  16. Gamma-ray Output Spectra from 239Pu Fission

    Directory of Open Access Journals (Sweden)

    Ullmann John

    2015-01-01

    Full Text Available Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.

  17. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  18. Peroxisome proliferator activated receptor-gamma (PPAR-gamma) mediates the action of gamma linolenic acid in breast cancer cells.

    Science.gov (United States)

    Jiang, W G; Redfern, A; Bryce, R P; Mansel, R E

    2000-02-01

    Gamma linolenic acid (GLA) is a polyunsaturated fatty acid, which induces cytotoxicity and regulates cell adhesion in cancer cells. The molecular mechanism of these actions is not clear. We have shown that GLA acts via peroxisome proliferator activated receptors (PPARs), by stimulating their phosphorylation and translocation to the nucleus. Removing PPAR gamma with antisense oligos abolished the effect of GLA on the expression of adhesion molecules and tumour suppressor genes, whereas removal of PPAR alpha had no effect. Tissues from patients with breast cancer showed a reduction of expression of both PPARs in cancer tissues, as compared with normal. Thus, PPAR gamma serves as the receptor for GLA in the regulation of gene expression in breast cancer cells.

  19. Modification and characterization of sites giving acid cracking on aluminium oxide supports; Modification et caracterisation des sites responsables du craquage acide sur des supports a base d`alumine

    Energy Technology Data Exchange (ETDEWEB)

    Guillaume, D.

    1997-10-23

    The aim of this work is to characterize the surface acid properties of {gamma} alumina, especially the nature, the amount, the strength and the environment of acid sites. The techniques that have been used are: the thermo-desorption of trimethyl-phosphine followed by {sup 31}P MAS NMR, the infrared spectroscopy, the n-heptane cracking, the modification of {gamma} alumina by the addition of chlorine, silicon and alkali (K{sup +}, Na{sup +}), alkaline-earths (Mg{sup 2+}, Ca{sup 2+}), lanthanum (La{sup 3+}) cations. The combination of these techniques has allowed to identify the surface acid properties of {gamma} alumina through the n-heptane transformation reactions under reforming conditions. We have shown that Lewis acidity is responsible for cracking reactions leading to C{sub 1}-C{sub 6} and C{sub 2}-C{sub 5} whereas the cracking of n-heptane producing C{sub 3}-C{sub 4} is due to Broensted acid sites. The isomerization and cyclization reactions both require weaker Broensted acid sites than cracking leading to C{sub 3}-C{sub 4}. The mechanisms involved in the formation of products of these reactions have been identified. Despite the complexity of surface acid properties of {gamma} alumina, this study has determined the environment of catalytically active sites, considering the presence of cation vacancies. (author) 206 refs.

  20. The antiviral response to gamma interferon.

    Science.gov (United States)

    Costa-Pereira, Ana P; Williams, Timothy M; Strobl, Birgit; Watling, Diane; Briscoe, James; Kerr, Ian M

    2002-09-01

    A role for alpha/beta interferon (IFN-alpha/beta) in the IFN-gamma antiviral response has long been suggested. Accordingly, possible roles for autocrine or double-stranded-RNA (dsRNA)-induced IFN-alpha/beta in the IFN-gamma response were investigated. Use was made of wild-type and a variety of mutant human fibrosarcoma cell lines, including mutant U5A cells, which lack a functional IFN-alpha/beta receptor and hence an IFN-alpha/beta response. IFN-gamma did not induce detectable levels of IFN-alpha/beta in any of the cell lines, nor was the IFN-gamma response per se dependent on autocrine IFN-alpha/beta. On the other hand, a number of responses to dsRNA [poly(I). poly(C)] and encephalomyocarditis virus were greatly enhanced by IFN-gamma pretreatment (priming) of wild-type cells or of mutant cells lacking an IFN-alpha/beta response; these include the primary induction of dsRNA-inducible mRNAs, including IFN-beta mRNA, and, to a lesser extent, the dsRNA-mediated activation of the p38 mitogen-activated protein (MAP) kinase(s). IFN-gamma priming of mRNA induction by dsRNA is dependent on JAK1 and shows biphasic kinetics, with an initial rapid (<30-min) response being followed by a more substantial effect on overnight incubation. The IFN-gamma-primed dsRNA responses appear to be subject to modulation through the p38, phosphatidylinositol 3-kinase, and ERK1/ERK2 MAP kinase pathways. It can be concluded that despite efficient priming of IFN-beta production, the IFN-alpha/beta pathways play no significant role in the primary IFN-gamma antiviral response in these cell-virus systems. The observed IFN-gamma priming of dsRNA responses, on the other hand, will likely play a significant role in combating virus infection in vivo.

  1. Chromatin Modifications Associated With Diabetes and Obesity.

    Science.gov (United States)

    Schones, Dustin E; Leung, Amy; Natarajan, Rama

    2015-07-01

    The incidence of obesity across the globe has doubled over the past several decades, leading to escalating rates of diabetes mellitus, cardiovascular disease, and other complications. Given this dramatic rise in disease incidence, understanding the cause of these diseases is therefore of paramount importance. Metabolic diseases, such as obesity and diabetes mellitus, result from a multitude of genetic and environmental factors. Although the genetic basis of these diseases has been extensively studied, the molecular pathways whereby environmental factors influence disease progression are only beginning to be understood. One manner by which environmental factors can contribute to disease progression is through modifications to chromatin. The highly structured packaging of the genome into the nucleus through chromatin has been shown to be fundamental to tissue-specific gene regulation. Modifications to chromatin can regulate gene expression and are involved in a myriad of biological functions, and hence, disruption of these modifications is central to many human diseases. These modifications can furthermore be epigenetic in nature, thereby contributing to prolonged disease risk. Recent work has demonstrated that modifications to chromatin are associated with the progression of both diabetes mellitus and obesity, which is the subject of this review. © 2015 American Heart Association, Inc.

  2. Effect of gamma irradiation on opto-structural, dielectric, and thermoluminescence properties of natural phlogopite mica

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Sukhnandan; Singh, Surinder; Singh, Lakhwant [Department of Physics, Guru Nanak Dev University, Amritsar 143005, Punjab (India); Lochab, S. P. [Inter University Accelerator Centre, New Delhi 110067 (India)

    2013-09-07

    Gamma ray induced modifications in natural phlogopite mica have been studied in the dose range of 1–2000 kGy. These modifications were monitored using different techniques viz: ultraviolet-visible spectroscopy, Fourier Transform Infrared spectroscopy, dielectric measurements, X-ray diffraction, and thermoluminescence dosimeter. The analysis of the results reveals that the dose of 100 kGy produces significant change in the natural phlogopite mica as compared to pristine and other exposed samples. Ultraviolet-visible analysis provides the value of optical indirect, direct band gap, and Urbach energy. Cody model was used to calculate structural disorder from Urbach energy. Different dielectric parameters such as dielectric constant, dielectric loss, ac conductivity, and real and imaginary parts of electric modulus were calculated for pristine and irradiated samples at room temperature. Williamson Hall analysis was employed to calculate crystallite size and micro-strain of pristine and irradiated sheets. No appreciable changes in characteristic bands were observed after irradiation, indicating that natural phlogopite mica is chemically stable. The natural phlogopite mica may be recommended as a thermoluminescent dosimeter for gamma dose within 1 kGy–300 kGy.

  3. Dielectric relaxation of gamma irradiated muscovite mica

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navjeet [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Singh, Mohan, E-mail: mohansinghphysics@gmail.com [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Singh, Lakhwant [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Awasthi, A.M. [Thermodynamics Laboratory, UGC-DAE Consortium for Scientific Research, Indore 452001 (India); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-03-15

    Highlights: • The present article reports the effect of gamma irradiation on the dielectric relaxation characteristics of muscovite mica. • Dielectric and electrical relaxations have been analyzed in the framework of dielectric permittivity, electric modulus and Cole–Cole formalisms. • The frequency dependent electrical conductivity has been rationalized using Johnsher’s universal power law. • The experimentally measured electric modulus and conductivity data have been fitted using Havriliak–Negami dielectric relaxation function. - Abstract: In the present research, the dielectric relaxation of gamma irradiated muscovite mica was studied in the frequency range of 0.1 Hz–10 MHz and temperature range of 653–853 K, using the dielectric permittivity, electric modulus and conductivity formalisms. The dielectric constants (ϵ′ and ϵ′′) are found to be high for gamma irradiated muscovite mica as compared to the pristine sample. The frequency dependence of the imaginary part of complex electric modulus (M′′) and dc conductivity data conforms Arrhenius law with single value of activation energy for pristine sample and two values of activation energy for gamma irradiated mica sample. The experimentally assessed electric modulus and conductivity information have been interpreted by the Havriliak–Negami dielectric relaxation explanation. Using the Cole–Cole framework, an analysis of real and imaginary characters of the electric modulus for pristine and gamma irradiated sample was executed which reflects the non-Debye relaxation mechanism.

  4. Stellar Photon Archaeology with Gamma-Rays

    Science.gov (United States)

    Stecker, Floyd W.

    2009-01-01

    Ongoing deep surveys of galaxy luminosity distribution functions, spectral energy distributions and backwards evolution models of star formation rates can be used to calculate the past history of intergalactic photon densities and, from them, the present and past optical depth of the Universe to gamma-rays from pair production interactions with these photons. The energy-redshift dependence of the optical depth of the Universe to gamma-rays has become known as the Fazio-Stecker relation (Fazio & Stecker 1970). Stecker, Malkan & Scully have calculated the densities of intergalactic background light (IBL) photons of energies from 0.03 eV to the Lyman limit at 13.6 eV and for 0$ < z < $6, using deep survey galaxy observations from Spitzer, Hubble and GALEX and have consequently predicted spectral absorption features for extragalactic gamma-ray sources. This procedure can also be reversed. Determining the cutoff energies of gamma-ray sources with known redshifts using the recently launched Fermi gamma-ray space telescope may enable a more precise determination of the IBL photon densities in the past, i.e., the "archaeo-IBL.", and therefore allow a better measure of the past history of the total star formation rate, including that from galaxies too faint to be observed.

  5. Gamma-Ray Astronomy from the Ground

    CERN Document Server

    Horns, D

    2016-01-01

    The observation of cosmic gamma-rays from the ground is based upon the detection of gamma-ray initiated air showers. At energies between approximately $10^{11}$ eV and $10^{13}$ eV, the imaging air Cherenkov technique is a particularly successful approach to observe gamma-ray sources with energy fluxes as low as $\\approx 10^{-13}$ erg\\,cm$^{-2}\\,$s$^{-1}$. The observations of gamma-rays in this energy band probe particle acceleration in astrophysical plasma conditions and are sensitive to high energy phenomena beyond the standard model of particle physics (e.g., self-annihilating or decaying dark matter, violation of Lorentz invariance, mixing of photons with light pseudo-scalars). The current standing of the field and its major instruments are summarised briefly by presenting selected highlights. A new generation of ground based gamma-ray instruments is currently under development. The perspectives and opportunities of these future facilities will be discussed.

  6. Improved gamma bang time measurements on omega

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, H W; Caldwell, S E; Evans, S C; Mack, J M; Sanchez, P; Sedillo, T; Wilson, D C; Young, C S [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Drew, D; Horsfield, C J [Atomic Weapons Establishment, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Glebov, V Y; Stoeckl, C [Laboratory for Laser Energetics, University of Rochester, Rochester, NY (United States); Macrum, G S; Miller, E K [National Security Technologies/Special Technologies Lab, Santa Barbara, CA (United States)], E-mail: herrmann@lanl.gov

    2008-05-15

    The time of peak fusion reactivity with respect to the impingement of laser light on an Inertial Confinement Fusion (ICF) capsule is known as Bang Time (BT). For deuterium-tritium fueling, fusion reactivity and BT can be measured using either fusion neutrons or fusion gammas. Initial gamma bang time (GBT) measurements on Omega using a Gas Cherenkov Detector (GCD) have been previously reported. Recent improvements have significantly enhanced the ability to measure GBT precisely. By relating the peak of the GCD gamma signal to laser timing fiducials, and cross calibrating the resulting raw bang time to the neutron bang time obtained using the absolutely calibrated Neutron Temporal Diagnostic (NTD), we demonstrate a precision of better than 25 ps on Omega. Bang time, along with other aspects of reaction history (RH), is an essential component of diagnosing failed attempts at ICF ignition. For the NIF, gammas are preferred over neutrons for this application due to the unacceptably large neutron temporal spreading resulting from detector standoff limitations on the NIF. The NIF System Design Requirement specifies a gamma bang time accuracy of better than 50 ps.

  7. Stellar Photon Archaeology with Gamma-Rays

    Science.gov (United States)

    Stecker, Floyd W.

    2009-01-01

    Ongoing deep surveys of galaxy luminosity distribution functions, spectral energy distributions and backwards evolution models of star formation rates can be used to calculate the past history of intergalactic photon densities and, from them, the present and past optical depth of the Universe to gamma-rays from pair production interactions with these photons. The energy-redshift dependence of the optical depth of the Universe to gamma-rays has become known as the Fazio-Stecker relation (Fazio & Stecker 1970). Stecker, Malkan & Scully have calculated the densities of intergalactic background light (IBL) photons of energies from 0.03 eV to the Lyman limit at 13.6 eV and for 0$ < z < $6, using deep survey galaxy observations from Spitzer, Hubble and GALEX and have consequently predicted spectral absorption features for extragalactic gamma-ray sources. This procedure can also be reversed. Determining the cutoff energies of gamma-ray sources with known redshifts using the recently launched Fermi gamma-ray space telescope may enable a more precise determination of the IBL photon densities in the past, i.e., the "archaeo-IBL.", and therefore allow a better measure of the past history of the total star formation rate, including that from galaxies too faint to be observed.

  8. Gamma-ray limits on neutrino lines

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Farinaldo S.; Yaguna, Carlos E.; Weniger, Christoph [Max-Planck-Institut für Kernphysik,Saupfercheckweg 1, 69117 Heidelberg (Germany); GRAPPA Institute, University of Amsterdam,Science Park 904, 1090 GL Amsterdam, Netherland (Netherlands)

    2016-05-23

    Monochromatic neutrinos from dark matter annihilations (χχ→νν-bar) are always produced in association with a gamma-ray spectrum generated by electroweak bremsstrahlung. Consequently, these neutrino lines can be searched for not only with neutrino detectors but also indirectly with gamma-ray telescopes. Here, we derive limits on the dark matter annihilation cross section into neutrinos based on recent Fermi-LAT and HESS data. We find that, for dark matter masses above 200 GeV, gamma-ray data actually set the most stringent constraints on neutrino lines from dark matter annihilation and, therefore, an upper bound on the dark matter total annihilation cross section. In addition, we point out that gamma-ray telescopes, unlike neutrino detectors, have the potential to distinguish the flavor of the final state neutrino. Our results indicate that we have already entered into a new era where gamma-ray telescopes are more sensitive than neutrino detectors to neutrino lines from dark matter annihilation.

  9. Influence of the temperature in the measurement of the gamma automatic probe Gamma Tracer; Influencia de la temperatura en la medicion de la sonda gamma automatica Gamma Tracer

    Energy Technology Data Exchange (ETDEWEB)

    Caveda R, C.A.; Dominguez L, O.; Alonso A, D. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba); Montalvan E, A.; Fabelo B, O. [CIAC, Ave. Finlay Km 2 1/2, Rpto. Puerto Principe, Camaguey 70800 (Cuba)]. e-mail: caveda@cphr.edu.cu

    2006-07-01

    In the following work an analysis of the existent relationship among the measurement of the absorbed dose rate in air due to the environmental gamma radiation and the temperature, magnitudes measured to intervals of 10 minutes by the gamma probe Gamma Tracer located in the post of occident of the National Net of Environmental Radiological Surveillance (RNVRA), in the Center of Protection and Hygiene of the Radiations (CPHR) is made. For it its were analyzed near 100,000 measurements corresponding to the period 2004-2005. For a better processing and interpretation of the data, these were analyzed with one frequency time zone and monthly using the Gamma Red software to which was necessary to add it some options. Finally it was submitted the probe to a heating process inside a stove. The results of the carried out experiments confirmed that the absorbed dose rate in air due to the environmental gamma radiation depends potentially of the probe temperature in the range of environmental temperature to which is subjected daily the same one. (Author)

  10. Gamma Radiation Effects on Peanut Skin Antioxidants

    Directory of Open Access Journals (Sweden)

    Adriano Costa de Camargo

    2012-03-01

    Full Text Available Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ. Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h, measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts’ antioxidative properties when added to soybean oil.

  11. Gamma radiation effects on peanut skin antioxidants.

    Science.gov (United States)

    de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D'Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.

  12. Urban gamma spectrometry. Report 1

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  13. Research on novel crosslinkers of polyolefins using {gamma}-ray

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Dong Hack; Lee, In jai; Yang, Nam Choul; Hwang, Jo Il; Chung, Woo Young [Hanyang University, Seoul (Korea)

    2001-04-01

    The radiation processing has been widely used as the modification technique to develop new materials such as high performance polymers in which the conventional chemical processing has been unable to apply. For the purpose of using in nuclear power plants, cable materials are required to have excellent physical and chemical properties such as high thermal, radiation and chemical stabilities. Conventional crosslinkers for cable materials such as triallyl cyanurate-based amine derivatives show low melting points and high vapor pressures, which causes the large weight loss due to the high working temperature during the procedure of the film preparation. In this research, we synthesized crosslinkers having imide groups to increase thermal and radiation stabilities. The mixture of LDPE and these crosslinkers was irradiated with 60Co {gamma}-rays at room temperature in nitrogen. The absorbed does range from 1-160KGy. The synthesized crosslinkers showed a good compatibility with LDPE. Among these crosslinkers, m-xylylenedimaleimide is the best in gel fraction enhancement. LDPE crosslinked with m-xylylenedimaleimide displays higher tensile strength than that crosslinked with triallyl cyanurate. In case of elongation property, the usage of m-xylylenedimaleimide crosslinker shows the best result than those of commercial crosslinkers such as triallyl cyanurate and trimethylol propane triacrylate. 24 refs., 21 figs., 1 tabs. (Author)

  14. Positron annihilation induced Auger and gamma spectroscopies of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, A.H. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States)]. E-mail: weiss@uta.edu; Fazleev, N.G. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States); Nadesalingam, M.P. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States); Mukherjee, S. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States); Xie, S. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States); Zhu, J. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States); Davis, B.R. [Physics Department, Box 19059, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2007-02-15

    The annihilation of positrons with core electrons results in an element specific signature in the spectra of Auger-electron and annihilation gamma rays. Because a large fraction of positrons implanted at low energies become trapped just outside the surface, annihilation induced Auger and Gamma signals probe the surfaces of solids with single atomic layer depth resolution. Recent applications of positron annihilation-induced Auger electron spectroscopy (PAES) and Auger-gamma coincidence spectroscopy (AGCS) and future applications of Auger-gamma and gamma-gamma coincidence spectroscopy are discussed.

  15. Positron annihilation induced Auger and gamma spectroscopies of surfaces

    Science.gov (United States)

    Weiss, A. H.; Fazleev, N. G.; Nadesalingam, M. P.; Mukherjee, S.; Xie, S.; Zhu, J.; Davis, B. R.

    2007-02-01

    The annihilation of positrons with core electrons results in an element specific signature in the spectra of Auger-electron and annihilation gamma rays. Because a large fraction of positrons implanted at low energies become trapped just outside the surface, annihilation induced Auger and Gamma signals probe the surfaces of solids with single atomic layer depth resolution. Recent applications of positron annihilation-induced Auger electron spectroscopy (PAES) and Auger-gamma coincidence spectroscopy (AGCS) and future applications of Auger-gamma and gamma-gamma coincidence spectroscopy are discussed.

  16. Identification and Interrogation of Combinatorial Histone Modifications

    Directory of Open Access Journals (Sweden)

    Kelly R Karch

    2013-12-01

    Full Text Available Histone proteins are dynamically modified to mediate a variety of cellular processes including gene transcription, DNA damage repair, and apoptosis. Regulation of these processes occurs through the recruitment of non-histone proteins to chromatin by specific combinations of histone post-translational modifications (PTMs. Mass spectrometry has emerged as an essential tool to discover and quantify histone PTMs both within and between samples in an unbiased manner. Developments in mass spectrometry that allow for characterization of large histone peptides or intact protein has made it possible to determine which modifications occur simultaneously on a single histone polypeptide. A variety of techniques from biochemistry, biophysics, and chemical biology have been employed to determine the biological relevance of discovered combinatorial codes. This review first describes advancements in the field of mass spectrometry that have facilitated histone PTM analysis and then covers notable approaches to probe the biological relevance of these modifications in their nucleosomal context.

  17. Design inspections for systems undergoing design modifications

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, B.K.; Norkin, D.P.

    1987-01-01

    The US Nuclear Regulatory Commission's (NRC's) Office of Inspection and Enforcement (IE) has conducted direct inspections (integrated design inspections) of the technical aspects of the nuclear plant design process for several plants under construction. It has also evaluated independent design verification programs and engineering assurance programs at a number of other plants under construction. Many of the lessons learned from these construction phase efforts are directly applicable to operating plants undergoing major modifications. This has been confirmed by IE direct inspections of the design aspects of safety systems outage modifications, which have identified significant potential safety-related deficiencies. The paper discusses methodology for design inspections; failure to maintain up-to-date design basis documentation; and lessons learned common to plants under construction and undergoing major modifications.

  18. Proposed Modification of the Progressive Retirement Programme

    CERN Document Server

    2003-01-01

    After discussion at TREF on 29 October 2003, the Management proposes in this document a modification affecting one of the general principles of the Progressive Retirement Programme (PRP), decided by the Council in December 1996 and introduced in April 1997. This modification would authorise the Director-General, in exceptional cases, as indicated in section 3 below, and, with the staff member's consent, to cancel his or her participation in the PRP and to reinstate the staff member in his or her original contractual situation. No modifications to the Staff Rules and Regulations are required. The proposal set out in section 3 of the present document is submitted by the Management, after consultation of the Governing Board of the Pension Fund, for recommendation by the Finance Committee to the Council and for approval by the Council, to enter into force as of 1 January 2004.

  19. [Epigenic modifications associated with low benzene exposure].

    Science.gov (United States)

    Fustinoni, Silvia; Bollati, Valentina; Bertazzi, Pier Alberto

    2013-01-01

    DNA methylation, mitochondrial DNA copy number and telomeres shortening are cellular modifications associated with an increasing number of tumors, cardiovascular and aging diseases. In our studies these modifications were evaluated in subjects occupationally exposed to low levels of benzene and in the general population. In peripheral blood lymphocytes a decrease of DNA methylation with the increase of personal benzene exposure was found, both in Alu and LINE-1 repetitive elements, and in the global DNA. Telomere length shortening in subjects exposed to traffic exhausts and an increase in mitochondrial DNA copy number correlated to benzene exposure was also found. DNA methylation measured in specimen repeats collected at intervals of 8 years decreased more markedly in exposed subjects than in controls. Our studies highlighted the association of epigenetic modifications of DNA with low benzene exposure.

  20. Alkyl- and fluoroalkyltrialkoxysilanes for wettability modification

    Energy Technology Data Exchange (ETDEWEB)

    Dopierala, Katarzyna, E-mail: katarzyna.dopierala@put.poznan.pl [Institute of Chemical Technology and Engineering, Poznan University of Technology, Pl. Marii Skłodowskiej-Curie 2, Poznań 60-965 (Poland); Maciejewski, Hieronim [Poznań Science and Technology Park, Rubież 46, Poznań 61-612 (Poland); Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, Poznań 60-780 (Poland); Karasiewicz, Joanna [Poznań Science and Technology Park, Rubież 46, Poznań 61-612 (Poland); Prochaska, Krystyna [Institute of Chemical Technology and Engineering, Poznan University of Technology, Pl. Marii Skłodowskiej-Curie 2, Poznań 60-965 (Poland)

    2013-10-15

    Alkyl- and fluoroalkyltriethoxysilanes were investigated as potential surface modifiers. Many aspects concerning trialkoxysilanes were discussed, starting from hydrolysis of silanes in water solutions, the effect of this hydrolysis on the surface tension, wettability of the modified surface to the morphology of the modified surface. Surface tension and contact angle measurements as well as scanning electron microscopy were used to characterise alkyl- and fluoroalkyltriethoxysilanes and their ability to modify the wettability of glass. The effect of such modification was superhydrophobic surface with high values of contact angles. Superhydrophobic behaviour was observed as a result of two-step modification providing increased surface roughness thanks to the use of different size silica particles and surface chemical modification with fluorosilane molecules.