WorldWideScience

Sample records for residually protonated samples

  1. Peptides containing internal residues of pyroglutamic acid: proton NMR characteristics

    International Nuclear Information System (INIS)

    Khan, S.A.

    1986-01-01

    The proton NMR characteristics of internal pyroglutamic acid (Glp; 5-oxoproline) residues in seven tripeptides of the general structure Boc-Xxx-Glp-Yyy-NH 2 were studied. In general, the chemical shifts of several diagnostic protons moved downfield on going from the Glu-containing peptides (Boc-Xxx-Glu-Yyy-NH 2 ) to the corresponding Glp-containing peptides. The C-2 proton of the Xxx residue was shifted by about 1.1 ppm. The N-2 proton of the Yyy residue was shifted by about 0.5 ppm. The C-2 proton of the Glx residue itself was shifted by about 0.5 ppm. One of the Glx C-3 protons was also shifted by about 0.5 ppm, but the other remained essentially unchanged. Finally, the Glx C-4 protons were shifted by about 0.3 ppm. Internal Glu residues are readily converted chemically into internal Glp residues. This conversion also occurs as a side reaction during HP cleavage of the protecting group from Glu(OBzl) residues. The spontaneous fragmentation of serum proteins C3, C4 and λ 2 -macroglobulin under denaturing conditions is probably due to regioselective hydrolysis of an internal Glp residue formed in each of these proteins upon denaturation. These proton NMR characteristics may be useful in establishing the presence of internal Glp residues in synthetic and natural peptides

  2. Protein-protein docking with dynamic residue protonation states.

    Directory of Open Access Journals (Sweden)

    Krishna Praneeth Kilambi

    2014-12-01

    Full Text Available Protein-protein interactions depend on a host of environmental factors. Local pH conditions influence the interactions through the protonation states of the ionizable residues that can change upon binding. In this work, we present a pH-sensitive docking approach, pHDock, that can sample side-chain protonation states of five ionizable residues (Asp, Glu, His, Tyr, Lys on-the-fly during the docking simulation. pHDock produces successful local docking funnels in approximately half (79/161 the protein complexes, including 19 cases where standard RosettaDock fails. pHDock also performs better than the two control cases comprising docking at pH 7.0 or using fixed, predetermined protonation states. On average, the top-ranked pHDock structures have lower interface RMSDs and recover more native interface residue-residue contacts and hydrogen bonds compared to RosettaDock. Addition of backbone flexibility using a computationally-generated conformational ensemble further improves native contact and hydrogen bond recovery in the top-ranked structures. Although pHDock is designed to improve docking, it also successfully predicts a large pH-dependent binding affinity change in the Fc-FcRn complex, suggesting that it can be exploited to improve affinity predictions. The approaches in the study contribute to the goal of structural simulations of whole-cell protein-protein interactions including all the environmental factors, and they can be further expanded for pH-sensitive protein design.

  3. Tank 12H residuals sample analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shine, E. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  4. Residual correlation in two-proton interferometry from Λ-proton strong interactions

    International Nuclear Information System (INIS)

    Wang, Fuqiang

    1999-01-01

    We investigate the residual effect of Λp strong interactions in pp correlations with one proton from Λ decays. It is found that the residual correlation is about 10% of the Λp correlation strength, and has a broad distribution centered around q≅40 MeV/c. The residual correlation cannot explain the observed structure on the tail of the recently measured pp correlation function in central Pb+Pb collisions by NA49 at the Super Proton Synchrotron. (c) 1999 The American Physical Society

  5. Sampling and sample processing in pesticide residue analysis.

    Science.gov (United States)

    Lehotay, Steven J; Cook, Jo Marie

    2015-05-13

    Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

  6. Application of proton-induced X-ray emission technique to gunshot residue analyses

    International Nuclear Information System (INIS)

    Sen, P.; Panigrahi, N.; Rao, M.S.; Varier, K.M.; Sen, S.; Mehta, G.K.

    1982-01-01

    The proton-induced X-ray emission (PIXE) technique was applied to the identification and analysis of gunshot residues. Studies were made of the type of bullet and bullet hole identification, firearm discharge element profiles, the effect of various target backings, and hand swabbings. The discussion of the results reviews the sensitivity of the PIXE technique, its nondestructive nature, and its role in determining the distance from the gun to the victim and identifying the type of bullet used and whether a wound was made by a bullet or not. The high sensitivity of the PIXE technique, which is able to analyze samples as small as 0.1 to 1 ng, and its usefulness for detecting a variety of elements should make it particularly useful in firearms residue investigations

  7. Distribution of pesticide residues in soil and uncertainty of sampling.

    Science.gov (United States)

    Suszter, Gabriela K; Ambrus, Árpád

    2017-08-03

    Pesticide residues were determined in about 120 soil cores taken randomly from the top 15 cm layer of two sunflower fields about 30 days after preemergence herbicide treatments. Samples were extracted with acetone-ethyl acetate mixture and the residues were determined with GC-TSD. Residues of dimethenamid, pendimethalin, and prometryn ranged from 0.005 to 2.97 mg/kg. Their relative standard deviations (CV) were between 0.66 and 1.13. The relative frequency distributions of residues in soil cores were very similar to those observed in root and tuber vegetables grown in pesticide treated soils. Based on all available information, a typical CV of 1.00 was estimated for pesticide residues in primary soil samples (soil cores). The corresponding expectable relative uncertainty of sampling is 20% when composite samples of size 25 are taken. To obtain a reliable estimate of the average residues in the top 15 cm layer of soil of a field up to 8 independent replicate random samples should be taken. To obtain better estimate of the actual residue level of the sampled filed would be marginal if larger number of samples were taken.

  8. The residual proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The essential role of the valence, residual p-n interaction in the development of collectivity, though long known in general terms, has recently become increasingly apparent. A brief review of the p-n interaction is given, including some very basic nuclear data that illustrate its effects and the phenomenological N p N n scheme and the P-factor. This is followed by a discussion of recent experimental extractions of p-n matrix elements throughout the periodic table and theoretical efforts to understand them, in terms of both Shell and Nilsson models. 20 refs., 13 figs

  9. Extended Lipkin-type models with residual proton-neutron interaction

    International Nuclear Information System (INIS)

    Stoica, S.

    1999-01-01

    Extended Lipkin-Meshkov-Glick (LMG) models for testing the Random Phase Approximation (RPA) and proton-neutron Random Phase Approximation (pnRPA) methods are developed taking into account explicitly the proton and neutron degrees of freedom. First, an extended LMG model for testing RPA is developed. The proton and neutron Hamiltonians are taken to be of the LMG form and, in addition, a residual proton-neutron interaction is included. Exact solutions in a SU(2) x SU(2) basis as well as the RPA solutions for the energy spectrum of the model Hamiltonian are obtained. Then, the behaviour of the first collective excited state is studied as a function of the interaction parameters of the model using the exact and RPA methods. Secondly, an extended LMG model for testing pnRPA method is developed. Besides the proton and neutron single particle terms two types of residual proton-neutron interactions, one simulating a particle-particle and the other a particle-hole interaction, are included in the model Hamiltonian, so that the model is exactly solvable in an isospin SU(2) x SU(2) basis. The exact and pnRPA spectra of the model Hamiltonian are calculated as a function of the model parameters and compared to each other. Furthermore, charge-changing operators simulating a nuclear beta decay and their action on eigenfunctions of the model Hamiltonian are defined, and transition amplitude of them are calculated using exact and pnRPA wave functions. The best agreement between the exact RPA-type calculations for spectra and transitions, was obtained when the correlated RPA ground state, instead of the uncorrelated HF ground state was employed and when both kinds of residual interactions (i.e. like- and unlike-particle two-body interactions) are included in the model Hamiltonians. (author)

  10. NMR experiments for the measurement of proton-proton and carbon-carbon residual dipolar couplings in uniformly labelled oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Pastor, Manuel [Universidad de Santiago de Compostela, Laboratorio Integral de Estructura de Biomoleculas Jose. R. Carracido, Unidade de Resonancia Magnetica, RIAIDT (Spain)], E-mail: mmartin@usc.es; Canales-Mayordomo, Angeles; Jimenez-Barbero, Jesus [Departamento de Estructura y funcion de proteinas, Centro de Investigaciones Biologicas, CSIC (Spain)], E-mail: jjbarbero@cib.csic.es

    2003-08-15

    A 2D-HSQC-carbon selective/proton selective-constant time COSY, 2D-HSQC-(sel C, sel H)-CT COSY experiment, which is applicable to uniformly {sup 13}C isotopically enriched samples (U-{sup 13}C) of oligosaccharides or oligonucleotides is proposed for the measurement of proton-proton RDC in crowded regions of 2D-spectra. In addition, a heteronuclear constant time-COSY experiment, {sup 13}C-{sup 13}C CT-COSY, is proposed for the measurement of one bond carbon-carbon RDC in these molecules. These two methods provide an extension, to U-{sup 13}C molecules, of the original homonuclear constant time-COSY experiment proposed by Tian et al. (1999) for saccharides. The combination of a number of these RDC with NOE data may provide the method of choice to study oligosaccharide conformation in the free and receptor-bound state.

  11. Residual Nuclides Induced in Cu Target by a 250 MeV Proton Beam

    International Nuclear Information System (INIS)

    Zhang Hong-Bin; Zhang Xue-Ying; Ma Fei; Ju Yong-Qin; Ge Hong-Lin; Chen Liang; Zhang Yan-Bin; Li Yan-Yan; Luo Peng; Wang Jian-Guo; Wan Bo; Xu Xiao-Wei; Wei Ji-Fang; Zhou Bin

    2015-01-01

    Residual nuclide production is studied experimentally by bombarding a Cu target with a 250 MeV proton beam. The data are measured by the off-line γ-spectroscopy method. Six nuclides are identified and their cross sections are determined. The corresponding calculated results by the MCNPX and GEANT4 codes are compared with the experimental data to check the validity of the codes. A comparison shows that the MCNPX simulation has a better agreement with the experiment. The energy dependence of residual nuclide production is studied with the aid of MCNPX simulation, and it is found that the mass yields for the nuclides in the light mass region increase significantly with the proton energy. (paper)

  12. Analysis of industrial coke samples by activation with cyclotron protons

    International Nuclear Information System (INIS)

    Chaudhri, M.A.; Lee, M.M.; Spicer, B.M.

    1982-01-01

    A Melbourne Petrochemical Company was experiencing excessive coke formation in its ''cracking furnaces'', which was causing unnecessary stoppage of production and wastage of energy due to additional insulation. In order to investigate the possible causes of this excessive coke formation, we analyzed various coke samples and other coke-like materials obtained from these furnaces by activation with cyclotron-protons. Our results showed that, out of the two suspected coke promoters As and Sb whose small concentration in feed would produce greatly accelerated coke formation, As could not be detected in any of the eight samples investigated, while Sb was present in only one sample. However, we did observe Ca, Cr and Fe in all the samples, with surprisingly high concentrations in some of them. It has, therefore, been suggested that Ca, and perhaps Cr and Fe, but not As or Sb, could have been responsible for the excessive coke formation in the ''cracking furnaces''

  13. Protonation states of histidine and other key residues in deoxy normal human adult hemoglobin by neutron protein crystallography

    International Nuclear Information System (INIS)

    Kovalevsky, Andrey; Chatake, Toshiyuki; Shibayama, Naoya; Park, Sam-Yong; Ishikawa, Takuya; Mustyakimov, Marat; Fisher, S. Zoe; Langan, Paul; Morimoto, Yukio

    2010-01-01

    Using neutron diffraction analysis, the protonation states of 35 of 38 histidine residues were determined for the deoxy form of normal human adult hemoglobin. Distal and buried histidines may contribute to the increased affinity of the deoxy state for hydrogen ions and its decreased affinity for oxygen compared with the oxygenated form. The protonation states of the histidine residues key to the function of deoxy (T-state) human hemoglobin have been investigated using neutron protein crystallography. These residues can reversibly bind protons, thereby regulating the oxygen affinity of hemoglobin. By examining the OMIT F o − F c and 2F o − F c neutron scattering maps, the protonation states of 35 of the 38 His residues were directly determined. The remaining three residues were found to be disordered. Surprisingly, seven pairs of His residues from equivalent α or β chains, αHis20, αHis50, αHis58, αHis89, βHis63, βHis143 and βHis146, have different protonation states. The protonation of distal His residues in the α 1 β 1 heterodimer and the protonation of αHis103 in both subunits demonstrates that these residues may participate in buffering hydrogen ions and may influence the oxygen binding. The observed protonation states of His residues are compared with their ΔpK a between the deoxy and oxy states. Examination of inter-subunit interfaces provided evidence for interactions that are essential for the stability of the deoxy tertiary structure

  14. The Generation of Dehydroalanine Residues in Protonated Polypeptides: Ion/Ion Reactions for Introducing Selective Cleavages

    Science.gov (United States)

    Peng, Zhou; Bu, Jiexun; McLuckey, Scott A.

    2017-09-01

    We examine a gas-phase approach for converting a subset of amino acid residues in polypeptide cations to dehydroalanine (Dha). Subsequent activation of the modified polypeptide ions gives rise to specific cleavage N-terminal to the Dha residue. This process allows for the incorporation of selective cleavages in the structural characterization of polypeptide ions. An ion/ion reaction within the mass spectrometer between a multiply protonated polypeptide and the sulfate radical anion introduces a radical site into the multiply protonated polypeptide reactant. Subsequent collisional activation of the polypeptide radical cation gives rise to radical side chain loss from one of several particular amino acid side chains (e.g., leucine, asparagine, lysine, glutamine, and glutamic acid) to yield a Dha residue. The Dha residues facilitate preferential backbone cleavages to produce signature c- and z-ions, demonstrated with cations derived from melittin, mechano growth factor (MGF), and ubiquitin. The efficiencies for radical side chain loss and for subsequent generation of specific c- and z-ions have been examined as functions of precursor ion charge state and activation conditions using cations of ubiquitin as a model for a small protein. It is noted that these efficiencies are not strongly dependent on ion trap collisional activation conditions but are sensitive to precursor ion charge state. Moderate to low charge states show the greatest overall yields for the specific Dha cleavages, whereas small molecule losses (e.g., water/ammonia) dominate at the lowest charge states and proton catalyzed amide bond cleavages that give rise to b- and y-ions tend to dominate at high charge states. [Figure not available: see fulltext.

  15. Measurement of residual stresses in welded sample of dissimilar materials

    International Nuclear Information System (INIS)

    Mansur, Tanius Rodrigues; Gomes, Paulo de Tarso Vida; Scaldaferri, Denis Henrique Bianchi; Martins, Geraldo Antonio Scoralick; Atanazio Filho, Nelson do Nascimento

    2008-01-01

    reactors, what can generate significant residual stresses due so much to the welding procedure as for the difference of the coefficients of thermal expansion of the involved materials. In this work, are shown the results of the measurement of residual tensions in welded sample of steel carbon SA 508 Cl 3 and stainless steel 316L. The Inconel 182 was used as weld metal. (author)

  16. Hall effect measurements on proton-irradiated ROSE samples

    International Nuclear Information System (INIS)

    Biggeri, U.; Bruzzi, M.; Borchi, E.

    1997-01-01

    Bulk samples obtained from two wafers of a silicon monocrystal material produced by Float-Zone refinement have been analyzed using the four-point probe method. One of the wafers comes from an oxygenated ingot; two sets of pure and oxygenated samples have been irradiated with 24 GeV/c protons in the fluence range from 10 13 p/cm 2 to 2x10 14 p/cm 2 . Van der Pauw resistivity and Hall coefficient have been measured before and after irradiation as a function of the temperature. A thermal treatment (30 minutes at 100C) has been performed to accelerate the reverse annealing effect in the irradiated silicon. The irradiated samples show the same exponential dependence of the resistivity and of the Hall coefficient on the temperature from 370K to 100K, corresponding to the presence of radiation-induced deep energy levels around 0.6-0.7eV in the silicon gap. The free carrier concentrations (n, p) have been evaluated in the investigated fluence range. The inversion of the conductivity type from n to p occurred respectively at 7x10 13 p/cm 2 and at 4x10 13 p/cm 2 before and after the annealing treatment, for both the two sets. Only slight differences have been detected between the pure and oxygenated samples

  17. Development of residual gas ionization profile monitor for high intensity proton beams

    CERN Document Server

    Sato, Y; Hirose, E; Ieiri, M; Igarashi, Y; Inaba, S; Katoh, Y; Minakawa, M; Noumi, H; Saitó, M; Suzuki, Y; Takahashi, H; Takasaki, M; Tanaka, K; Toyoda, A; Yamada, Y; Yamanoi, Y; Watanabe, H

    2006-01-01

    Nondestructive beam profile monitor utilizing ionizations of residual gas has been developed for continuous monitoring of 3?0(J-PARC). Knock-on electrons produced in the ionizations of residual gas vacuumed to 1 Pa are collected with a uniform electric field applied between electrodes. Applying a uniform electric field parallel to the electric field is essential to reduce diffusion of electrons crossing over magnetic flux. A prototype monitor has been constructed and installed in EP2-C beam line at KEK 12 GeV proton synchrotron (12 Ge V-PS). The profiles measured with the present monitor agree with the ones measured with the existing destructive profile monitor. The present monitor shows sufficient performances as a candidate of the profile monitor at J-PARC. In the present article, the working principle of the present monitor, the results of test experiments, and further developments are described in detail.

  18. Factors associated with residual gastroesophageal reflux disease symptoms in patients receiving proton pump inhibitor maintenance therapy.

    Science.gov (United States)

    Kawara, Fumiaki; Fujita, Tsuyoshi; Morita, Yoshinori; Uda, Atsushi; Masuda, Atsuhiro; Saito, Masaya; Ooi, Makoto; Ishida, Tsukasa; Kondo, Yasuyuki; Yoshida, Shiei; Okuno, Tatsuya; Yano, Yoshihiko; Yoshida, Masaru; Kutsumi, Hiromu; Hayakumo, Takanobu; Yamashita, Kazuhiko; Hirano, Takeshi; Hirai, Midori; Azuma, Takeshi

    2017-03-21

    To elucidate the factors associated with residual gastroesophageal reflux disease (GERD) symptoms in patients receiving proton pump inhibitor (PPI) maintenance therapy in clinical practice. The study included 39 GERD patients receiving maintenance PPI therapy. Residual symptoms were assessed using the Frequency Scale for Symptoms of GERD (FSSG) questionnaire and the Gastrointestinal Symptom Rating Scale (GSRS). The relationships between the FSSG score and patient background factors, including the CYP2C19 genotype, were analyzed. The FSSG scores ranged from 1 to 28 points (median score: 7.5 points), and 19 patients (48.7%) had a score of 8 points or more. The patients' GSRS scores were significantly correlated with their FSSG scores (correlation coefficient = 0.47, P reflux-related symptom scores: 12 ± 1.9 vs 2.5 ± 0.8, P reflux disease patients were significantly lower than those of the other patients (total scores: 5.5 ± 1.0 vs 11.8 ± 6.3, P < 0.05; dysmotility symptom-related scores: 1.0 ± 0.4 vs 6.0 ± 0.8, P < 0.01). Approximately half of the GERD patients receiving maintenance PPI therapy had residual symptoms associated with a lower quality of life, and the CYP2C19 genotype appeared to be associated with these residual symptoms.

  19. Long-term residual radioactivity in an intermediate-energy proton linac

    Science.gov (United States)

    Blaha, J.; La Torre, F. P.; Silari, M.; Vollaire, J.

    2014-07-01

    A new 160 MeV H- linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling water circuit were also quantified. The aim of this paper is to provide data of sufficiently general interest to be used for similar studies at other intermediate-energy proton accelerator facilities.

  20. Long-term residual radioactivity in an intermediate-energy proton linac

    International Nuclear Information System (INIS)

    Blaha, J.; La Torre, F.P.; Silari, M.; Vollaire, J.

    2014-01-01

    A new 160 MeV H − linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling water circuit were also quantified. The aim of this paper is to provide data of sufficiently general interest to be used for similar studies at other intermediate-energy proton accelerator facilities

  1. Impact of Intrafraction and Residual Interfraction Effect on Prostate Proton Pencil Beam Scanning

    International Nuclear Information System (INIS)

    Tang, Shikui; Deville, Curtiland; Tochner, Zelig; Wang, Ken Kang-Hsin; McDonough, James; Vapiwala, Neha; Both, Stefan

    2014-01-01

    Purpose: To quantitatively evaluate the impact of interplay effect and plan robustness associated with intrafraction and residual interfraction prostate motion for pencil beam scanning proton therapy. Methods and Materials: Ten prostate cancer patients with weekly verification CTs underwent pencil beam scanning with the bilateral single-field uniform dose (SFUD) modality. A typical field had 10-15 energy layers and 500-1000 spots. According to their treatment logs, each layer delivery time was <1 s, with average time to change layers of approximately 8 s. Real-time intrafraction prostate motion was determined from our previously reported prospective study using Calypso beacon transponders. Prostate motion and beam delivering sequence of the worst-case scenario patient were synchronized to calculate the “true” dose received by the prostate. The intrafraction effect was examined by applying the worst-case scenario prostate motion on the planning CT, and the residual interfraction effect was examined on the basis of weekly CT scans. The resultant dose variation of target and critical structures was examined to evaluate the interplay effect. Results: The clinical target volume (CTV) coverage was degraded because of both effects. The CTV D 99 (percentage dose to 99% of the CTV) varied up to 10% relative to the initial plan in individual fractions. However, over the entire course of treatment the total dose degradation of D 99 was 2%-3%, with a standard deviation of <2%. Absolute differences between SFUD, intensity modulate proton therapy, and one-field-per-day SFUD plans were small. The intrafraction effect dominated over the residual interfraction effect for CTV coverage. Mean dose to the anterior rectal wall increased approximately 10% because of combined residual interfraction and intrafraction effects, the interfraction effect being dominant. Conclusions: Both intrafraction and residual interfraction prostate motion degrade CTV coverage within a clinically

  2. Impact of Intrafraction and Residual Interfraction Effect on Prostate Proton Pencil Beam Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Shikui, E-mail: shktang@gmail.com [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); ProCure Proton Therapy Center, Somerset, New Jersey (United States); Deville, Curtiland; Tochner, Zelig [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wang, Ken Kang-Hsin [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); McDonough, James; Vapiwala, Neha; Both, Stefan [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2014-12-01

    Purpose: To quantitatively evaluate the impact of interplay effect and plan robustness associated with intrafraction and residual interfraction prostate motion for pencil beam scanning proton therapy. Methods and Materials: Ten prostate cancer patients with weekly verification CTs underwent pencil beam scanning with the bilateral single-field uniform dose (SFUD) modality. A typical field had 10-15 energy layers and 500-1000 spots. According to their treatment logs, each layer delivery time was <1 s, with average time to change layers of approximately 8 s. Real-time intrafraction prostate motion was determined from our previously reported prospective study using Calypso beacon transponders. Prostate motion and beam delivering sequence of the worst-case scenario patient were synchronized to calculate the “true” dose received by the prostate. The intrafraction effect was examined by applying the worst-case scenario prostate motion on the planning CT, and the residual interfraction effect was examined on the basis of weekly CT scans. The resultant dose variation of target and critical structures was examined to evaluate the interplay effect. Results: The clinical target volume (CTV) coverage was degraded because of both effects. The CTV D{sub 99} (percentage dose to 99% of the CTV) varied up to 10% relative to the initial plan in individual fractions. However, over the entire course of treatment the total dose degradation of D{sub 99} was 2%-3%, with a standard deviation of <2%. Absolute differences between SFUD, intensity modulate proton therapy, and one-field-per-day SFUD plans were small. The intrafraction effect dominated over the residual interfraction effect for CTV coverage. Mean dose to the anterior rectal wall increased approximately 10% because of combined residual interfraction and intrafraction effects, the interfraction effect being dominant. Conclusions: Both intrafraction and residual interfraction prostate motion degrade CTV coverage within a

  3. Field sampling of residual aviation gasoline in sandy soil

    International Nuclear Information System (INIS)

    Ostendorf, D.W.; Hinlein, E.S.; Yuefeng, Xie; Leach, L.E.

    1991-01-01

    Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions

  4. From the HINDAS Project: Excitation Functions for Residual Nuclide Production by Proton-Induced Reactions

    International Nuclear Information System (INIS)

    Michel, R.; Gloris, M.; Protoschill, J.; Uosif, M.A.M.; Weug, M.; Herpers, U.; Kuhnhenn, J.; Kubik, P.-W.; Schumann, D.; Synal, H.-A.; Weinreich, R.; Leya, I.; David, J.C.; Leray, S.; Duijvestijn, M.; Koning, A.; Kelic, A.; Schmidt, K.H.; Cugnon, J.

    2005-01-01

    A survey is given about efforts undertaken during the HINDAS project to investigate the energy dependence of residual nuclide production by proton-induced reactions from thresholds up to 2.6 GeV. For proton-induced reactions, our experiments aimed to further develop and complete the cross-section database that was established by our collaboration in recent years. It was extended to the heavy-target elements Ta, W, Pb, and Bi for energies up to 2.6 GeV. In addition, new measurements for the target element iron were performed up to 2.6 GeV and for natural uranium for energies from 21 MeV to 69 MeV. For the target element lead, a comprehensive set of excitation functions published recently was completed by AMS-measurements of cross sections for the production of the long-lived radionuclides Be-10, Al-26, Cl-36, and I-129 and by mass spectrometric measurements for stable and radioactive rare gas isotopes of He, Ne, Ar, Kr, and Xe. Comprehensive tests of the nuclear-reaction codes TALYS and INCL4+ABLA, which were developed within the HINDAS project, were performed with the new experimental results over the entire energy range

  5. Long-term residual radioactivity in an intermediate-energy proton linac

    CERN Document Server

    Blaha, J; Silari, M; Vollaire, J

    2014-01-01

    A new 160 MeV H−H− linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling w...

  6. Production of residual nuclides by proton-induced reactions on target W at the energy of 72 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Moazzem Hossain [Univ. of Chittagong, Dept. of Physics, Chittagong (Bangladesh); Kuhnhenn, Jochen; Herpers, Ulrich [Univ. of Cologne, Dept. of Nuclear Chemistry, Cologne (Germany); Michel, Rolf [University of Hannover, Centre for Radiation Protection and Radioecology (Germany); Kubik, Peter [Paul Scherrer Inst., c/o Institute for Particle Physics, ETH Hoenggerberg, Zuerich (Switzerland)

    2002-08-01

    Investigations of cross-sections for residual nuclide production on the target element W by proton-induced reactions were performed by irradiating the target with 72 MeV protons using the cyclotron facilities at Paul-Scherrer Institute, Zurich, Switzerland. Residual nuclides were measured by gamma-spectrometry of HpGe detectors calibrated with standard gamma sources. The measured data contains 104 individual cross-sections for 20 identified nuclides in the proton energies between 52.5 - 68.9 MeV. These nuclear data is important in the study of spallation neutron source and in accelerator driven technologies such as waste transmutation and energy amplification. The present data are compared with the shape of the excitation functions of earlier only one measurement at higher energies and they are in good agreement to each other. (author)

  7. Umbrella sampling of proton transfer in a creatine-water system

    Science.gov (United States)

    Ivchenko, Olga; Bachert, Peter; Imhof, Petra

    2014-04-01

    Proton transfer reactions are among the most common processes in chemistry and biology. Proton transfer between creatine and surrounding solvent water is underlying the chemical exchange saturation transfer used as a contrast in magnetic resonance imaging. The free energy barrier, determined by first-principles umbrella sampling simulations (EaDFT 3 kcal/mol) is in the same order of magnitude as the experimentally obtained activation energy. The underlying mechanism is a first proton transfer from the guanidinium group to the water pool, followed by a second transition where a proton is "transferred back" from the nearest water molecule to the deprotonated nitrogen atom of creatine.

  8. Effects of the residual proton-neutron interaction in the development of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The widespread effects of the residual T=0 proton-neutron (p-n) interaction in the evolution of nuclear structure are discussed. Although these effects in inducing single nucleon configuration mixing, and hence in the development of non-spherical nuclear shapes, collectivity, and the associated shape and phase transitions have been known for four decades, it is only in recent years that their deep ramifications have become more fully appreciated. This had led to a unified phenomenological understanding of the role of the p-n interaction in nuclear collectivity and to, for example, the proposal of the N p N n scheme and the associated concept of the P factor, which is a normalized value of N p N n reflecting the average number of p-n interactions per valence nucleon. Simultaneously, experimentally-determined p-n matrix elements for many nuclei have been extracted: they disclose striking anomalies for N=Z nuclei, and intriguing microstructure. These developments and empirical results will be discussed along with microscopic calculations that can be used to interpret them. 18 refs., 13 figs

  9. Suitability of the line intersect method for sampling hardwood logging residues

    Science.gov (United States)

    A. Jeff Martin

    1976-01-01

    The line intersect method of sampling logging residues was tested in Appalachian hardwoods and was found to provide unbiased estimates of the volume of residue in cubic feet per acre. Thirty-two chains of sample line were established on each of sixteen 1-acre plots on cutover areas in a variety of conditions. Estimates from these samples were then compared to actual...

  10. Clarification on the decarboxylation mechanism in KasA based on the protonation state of key residues in the acyl-enzyme state.

    Science.gov (United States)

    Lee, Wook; Engels, Bernd

    2013-07-11

    The β-ketoacyl ACP synthase I (KasA) is a promising drug target because it is essential for the survival of Mycobacterium tuberculosis , a causative agent of tuberculosis. It catalyzes a condensation reaction that comprises three steps. The resulting elongated acyl chains are subsequently needed for the cell wall construction. While the mechanism of the first step (acylation of Cys171 in the active site) is straightforward already, the second step (decarboxylation of malonyl substrate) has been controversial due to the difficulty in determining the correct protonation states of the involved residues (His311, His345, Lys340, Glu354). Available experimental data suggest three possible mechanisms which differ considerably. They are not consistent with each other because these studies could not be performed for KasA at the beginning of decarboxylation step (acyl-enzyme state of KasA). Instead, different mutants had to be used which are expected to resemble this situation. In this first computational study about this topic, we use the free energy perturbation (FEP) method to compute the relevant pKa values in the acyl-enzyme state of KasA and use molecular dynamics (MD) simulations to rationalize the results. Subsequent density functional theory (DFT)-based quantum mechanical/molecular mechanical (QM/MM) MD simulations and umbrella samplings have been used to disentangle the close relationships between the protonation states of the involved residues. By these simulations, we can address the preferred protonation states and roles of the residues involved in decarboxylation reaction, thereby suggesting the possible mechanism for the decarboxylation step.

  11. Prevalence of antimicrobial residues in eggs, tissue and feed samples in the State of Kuwait

    International Nuclear Information System (INIS)

    Alomirah, H.; Al-Mazeedi, H.; Al-Zenki, S.; Al-Faili, B.; Al-Foudary, M.; Abuzid, A.; Al-Sayed, I.; Sidhu, J.

    2007-01-01

    A total of 238 locally produced and imported eggs, tissue (meat, poultry and aquacultured fish) and feed and feedstuffs samples were collected at different seasonal periods from different farms and retail outlets in Kuwait and screened for presence of beta-lactams, tetracyclines, sulfonamides, streptomycin, macrolides and chloramphenicol (799 tests) using Charm II system. The results indicated that all of the 222 tests performed on table egg samples were negative for the analyzed antimicrobial residues indicating adherence to the guidelines for microbial use and withdrawal. Similarly, all of the 268 tests performed on tissue samples were negative for the analyzed antimicrobial residues except for chloramphenicol. These chloramphenicol positive samples, all of the 66 tests performed were negative for beta-lactams residues. Out of the 79 feed and feedstuff samples analyzed for teracyclines residues, broiler diet and concentrate samples (5%) were above the tetracyclines MRL (100 ppb.). On the other hands, results have revealed a widespread of sulfonamide residues and to a less extent chloramphenicol in tested feed and feedstuff samples. The Charm II system was reliable for rapid screening of antimicrobial residues. In general, results obtained in our study necessitate more effective and well planned national antimicrobial residues surveillance programs focusing particularly on samples imported from highly risk sources. (author)

  12. INC Model interpretation of the proton induced residual nuclide production cross sections below 2 GeV

    International Nuclear Information System (INIS)

    Divadeenam, M.; Ward, T.E.; Spergel, M.S.; Lakatos, S.; Manche, E.P.

    1991-01-01

    For the purposes of interpreting the abundances of various isotopes in meteorites or on lunar and planetary surfaces exposed to fragmentation by cosmic rays, Webber et al. recently reported the measured total elemental and isotopic cross sections with heavy ions as projectiles on H, He, and C targets with beam energies of 0.33 - 1.7 GeV/nucleon. We employ the INC model to predict the fragmentation of the heavy ions in a hydrogen target with the inverse reaction process: proton bombardment of a heavy-ion nucleus leading to spallation products. Charge-changing and mass-changing cross sections are calculated for proton bombardment of an 56 Fe target with beam energies ranging from 0.33 to 1.88 GeV. Total Z-changing and A-changing cross sections in the energy range 0.6 to 1.88 GeV are in excellent agreement with the corresponding experimental data of Webber et al. and Westfall at al., while the agreement below 0.6 GeV proton energy is not as good. The general trend of the Z-changing cross sections are reproduced by the model calculations at each proton incident energy. The interaction of 200-MeV protons with synthetic Stony Meteorite samples was undertaken to explain radionuclide production in a cosmic-ray environment. The BNL Linac 200-MeV-proton beam was used to irradiate synthetic Stony Meteorites to simulate cosmic-ray exposures corresponding to 6.4 and 16.4 million years. Each irradiated sample was analyzed with the help of a high-resolution gamma-ray spectrometer for long-lived radioisotopes. The intranuclear cascade code HETC was employed to simulate the 200-MeV proton bombardment on the meteorite samples to predict the radionuclides 7 Be, 22 Na, 46 Mn, and 56 Co produced in the experimental investigation

  13. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India

    Directory of Open Access Journals (Sweden)

    Korrapati Kotinagu

    2015-04-01

    Full Text Available Aim: The present study was conducted to find the organochlorine pesticide (OCP and organophosphorus pesticide (OPP residues in fodder and milk samples along Musi river belt, India. Materials and Methods: Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. Results: The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077. Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167. The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. Conclusion: The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  14. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India.

    Science.gov (United States)

    Kotinagu, Korrapati; Krishnaiah, Nelapati

    2015-04-01

    The present study was conducted to find the organochlorine pesticide (OCP) and organophosphorus pesticide (OPP) residues in fodder and milk samples along Musi river belt, India. Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077). Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167). The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL) values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  15. Quantum-mechanical analysis of amino acid residues function in the proton transport during F0F1-ATP synthase catalytic cycle

    Science.gov (United States)

    Ivontsin, L. A.; Mashkovtseva, E. V.; Nartsissov, Ya R.

    2017-11-01

    Implications of quantum-mechanical approach to the description of proton transport in biological systems are a tempting subject for an overlapping of fundamental physics and biology. The model of proton transport through the integrated membrane enzyme FoF1-ATP synthase responsible for ATP synthesis was developed. The estimation of the mathematical expectation of the proton transfer time through the half-channel was performed. Observed set of proton pathways through the inlet half-channel showed the nanosecond timescale highly dependable of some amino acid residues. There were proposed two types of crucial amino acids: critically localized (His245) and being a part of energy conserving system (Asp119).

  16. Isotopic production cross sections of fission residues in 197Au-on-proton collisions at 800 A MeV

    International Nuclear Information System (INIS)

    Benlliure, J.; Armbruster, P.; Bernas, M.

    2000-02-01

    Interactions of 197 Au projectiles at 800 A MeV with protons leading to fission are investigated. We measured the production cross sections and velocities of all fission residues which are fully identified in atomic and mass number by using the in-flight separator FRS at GSI. The new data are compared with partial measurements of the characteristics of fission in similar reactions. Both the production cross sections and the recoil energies are relevant for a better understanding of spallation reactions. (orig.)

  17. Cross-sections of spallation residues produced in 1A GeV 208Pb on proton reactions

    International Nuclear Information System (INIS)

    Wlazlo, W.; Uniwersytet Jagiellonski, Cracow; Enqvist, T.; Armbruster, P.

    2000-02-01

    Spallation residues produced in 1 GeV per nucleon 208 Pb on proton reactions have been studied using the fragment separator facility at GSI. Isotopic production cross-sections of elements from 61 Pm to 82 Pb have been measured down to 0.1 mb with a high accuracy. The recoil kinetic energies of the produced fragments were also determined. The obtained cross-sections agree with most of the few existing gamma-spectroscopy data. Data are compared with different intranuclear-cascade and evaporation-fission models. Drastic deviations were found for a standard code used in technical applications. (orig.)

  18. Measurement of nuclide cross-sections of spallation residues in 1 A GeV 238U + proton collisions

    International Nuclear Information System (INIS)

    Taieb, J.; Tassan-Got, L.; Bernas, M.; Mustapha, B.; Rejmund, F.; Stephan, C.; Schmidt, K.H.; Armbruster, P.; Benlliure, J.; Enqvist, T.; Boudard, A.; Legrain, R.; Leray, S.; Volant, C.; Wlazlo, W.; Casarejos, E.; Czajkowski, S.; Pravikoff, M.

    2003-02-01

    The production of heavy nuclides from the spallation-evaporation reaction of 238 U induced by 1 GeV protons was studied in inverse kinematics. The evaporation residues from tungsten to uranium were identified in-flight in mass and atomic number. Their production cross-sections and their momentum distributions were determined. The data are compared with empirical systematics. A comparison with previous results from the spallation of 208 Pb and 197 Au reveals the strong influence of fission in the spallation of 238 U. (orig.)

  19. Cross Sections for the Production of Residual Nuclides by Proton-Induced Reactions with Uranium at Medium Energies

    International Nuclear Information System (INIS)

    Issa, S.A.M.; Michel, R.; Uosif, M.A.M.; Issa, S.A.M.; Flamentc, J.L.; David, J.C.; Leray, S.

    2009-01-01

    The production of residual nuclides by proton-induced reactions on uranium is investigated using activated targets from irradiation experiments at Saturne II synchrocyclotron at the Laboratory National Saturne/Saclay. These investigations contribute to the European research project NUDATRA within the IP EUROTRANS in which the feasibility of accelerator-driven transmutation of nuclear waste is evaluated. Experimental cross sections are derived from gamma-spectrometric measurements. A total of 1894 cross-section was deter-mined covering 44 residual nuclides in the energy range from 211 MeV to 2530 MeV. The experimental data together with those of earlier work of our group are discussed in the context of theoretical excitation functions calculated by the newly developed INCL4 + ABLA and the TALYS codes

  20. Standardization of proton-induced x-ray emission technique for analysis of thick samples

    Science.gov (United States)

    Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

    2015-09-01

    This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

  1. Proton induced x-ray emission analysis of trace elements in thick bread samples

    International Nuclear Information System (INIS)

    Mohamed Baker Al-bedri; Ikram Jameel Abdul Ghani; Ibrahim Abdul Rahman Al-aghil

    2009-01-01

    Proton induced X-ray emission (PIXE) technique has been used for identification and quantitative analysis of the elemental concentration in thick bread samples. Bread samples were air-oven dried at 60degC and milled in a clean agate mortar to homogenize the sample and pressed into a pellet. PIXE technique relies on the analysis of the energy spectra of the characteristic X-ray emitted from the thick bread sample and the orchard leaf standard (NIST-SRM-1571) bombarded with 2.0 MeV protons. The concentration of the elements (Cl, K, Ca, Mn, Fe, Cu, and Zn) in the bread samples was determined by comparison with NIST orchard leaf standard. The accuracy of the measurements ranged between ±2% and ±10% for the most elements detected in this method. The aim of this study is to establish the reference concentration of trace elements in the Iraqi bread using PIXE technique. (author)

  2. Pesticide residues in individual versus composite samples of apples after fine or coarse spray quality application

    DEFF Research Database (Denmark)

    Poulsen, Mette E.; Wenneker, Marcel; Withagen, Jacques

    2012-01-01

    . None of the results for the pesticides residues measured in individual apples exceeded the EU Maximum Residue Levels (MRLs). However, there was a large variation in the residues levels in the apples, with levels from 0.01 to 1.4 mg kg−1 for captan, the pesticide with the highest variation, and from 0.......01 to 0.2 mg kg−1 for pyraclostrobin, the pesticide with the lowest variation. Residues of fenoxycarb and indoxacarb were only found in a few apples, probably due to the early application time of these two compounds. The evaluation of the effect of spray quality did not show any major difference between......In this study, field trials on fine and coarse spray quality application of pesticides on apples were performed. The main objectives were to study the variation of pesticide residue levels in individual fruits versus composite samples, and the effect of standard fine spray quality application...

  3. Cross-sections of spallation residues produced in Proton –Induced reactions

    International Nuclear Information System (INIS)

    Al-Haydari, A.; Khan, A.A.; Abdul Ganai, A.; Hassan, G.S.

    2013-01-01

    The recent available GSI data for proton-induced spallation reactions by using inverse kinematics at different energies are analyzed for different reactions in terms of the percolation model together with the intranuclear cascade model (MCAS). The simulation results obtained for the cross sections of production of light ions and isotopes as a function of mass and charge number is calculated. Results of calculations are in good agreement with experiment

  4. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    Energy Technology Data Exchange (ETDEWEB)

    Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Prime, Michael Bruce [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clausen, Bjorn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); DeWald, Adrian T. [Hill Engineering, LLC, Rancho Cordova, CA (United States)

    2015-12-08

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  5. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    International Nuclear Information System (INIS)

    Stroud, Mary Ann; Prime, Michael Bruce; Veirs, Douglas Kirk; Berg, John M.; Clausen, Bjorn; Worl, Laura Ann; DeWald, Adrian T.

    2015-01-01

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  6. The empirical residual proton-neutron interaction and the onset of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.

    1991-01-01

    The critical role of the residual valence p-n interaction in the development and evolution of collectivity, and the onset of shape/phase transitions, is discussed from the standpoint of phenomenological approaches, and empirical extraction of individual p-n interaction strengths, and simple model calculation of them. 22 refs., 18 figs

  7. Trace element studies in bioenvironmental samples using 3-MeV protons

    International Nuclear Information System (INIS)

    Walter, R.L.; Willis, R.D.; Gutknecht, W.F.

    1974-01-01

    Trace metal compositions of a wide range of biological, environmental, medical and clinical samples were investigated using proton-induced x-ray emission analysis (PIXEA). The x-rays were detected with a Si(Li) detector and spectra from over 3000 irradiations have been recorded on magnetic tape. The chi 2 fitting code TRACE developed at our laboratory was used in a semi-automatic mode to extract abundances of elements from S to Cd. Various methods of overcoming analytical problems and specimen preparation difficulties are reported. Results from some samples for typical studies are illustrated along with the reasons for interest in the sample types

  8. Clinical value of proton magnetic resonance spectroscopy for differentiating recurrent or residual brain tumor from delayed cerebral necrosis

    International Nuclear Information System (INIS)

    Taylor, June S.; Langston, James W.; Reddick, Wilburn E.; Kingsley, Peter B.; Ogg, Robert J.; Pui, Margaret H.; Kun, Larry E.; Jenkins, Jesse J.; Gang, Chen; Ochs, Judith J.; Sanford, Robert A.; Heideman, Richard L.

    1996-01-01

    Purpose: Delayed cerebral necrosis (DN) is a significant risk for brain tumor patients treated with high-dose irradiation. Although differentiating DN from tumor progression is an important clinical question, the distinction cannot be made reliably by conventional imaging techniques. We undertook a pilot study to assess the ability of proton magnetic resonance spectroscopy ( 1 H MRS) to differentiate prospectively between DN or recurrent/residual tumor in a series of children treated for primary brain tumors with high-dose irradiation. Methods and Materials: Twelve children (ages 3-16 years), who had clinical and MR imaging (MRI) changes that suggested a diagnosis of either DN or progressive/recurrent brain tumor, underwent localized 1 H MRS prior to planned biopsy, resection, or other confirmatory histological procedure. Prospective 1 H MRS interpretations were based on comparison of spectral peak patterns and quantitative peak area values from normalized spectra: a marked depression of the intracellular metabolite peaks from choline, creatine, and N-acetyl compounds was hypothesized to indicate DN, and median-to-high choline with easily visible creatine metabolite peaks was labeled progressive/recurrent tumor. Subsequent histological studies identified the brain lesion as DN or recurrent/residual tumor. Results: The patient series included five cases of DN and seven recurrent/residual tumor cases, based on histology. The MRS criteria prospectively identified five out of seven patients with active tumor, and four out of five patients with histologically proven DN correctly. Discriminant analysis suggested that the primary diagnostic information for differentiating DN from tumor lay in the normalized MRS peak areas for choline and creatine compounds. Conclusions: Magnetic resonance spectroscopy shows promising sensitivity and selectivity for differentiating DN from recurrent/progressive brain tumor. A novel diagnostic index based on peak areas for choline and

  9. Tracking protons from respiratory chain complexes to ATP synthase c-subunit: The critical role of serine and threonine residues.

    Science.gov (United States)

    Panfoli, Isabella; Ponassi, Marco; Ravera, Silvia; Calzia, Daniela; Beitia, Maider; Morelli, Alessandro; Rosano, Camillo

    2017-01-22

    F 1 F o -ATP synthase is a multisubunit enzyme responsible for the synthesis of ATP. Among its multiple subunits (8 in E. coli, 17 in yeast S. cerevisiae, 16 in vertebrates), two subunits a and c are known to play a central role controlling the H + flow through the inner mitochondrial membrane which allows the subsequent synthesis of ATP, but the pathway followed by H + within the two proteins is still a matter of debate. In fact, even though the structure of ATP synthase is now well defined, the molecular mechanisms determining the function of both F 1 and F O domains are still largely unknown. In this study, we propose a pathway for proton migration along the ATP synthase by hydrogen-bonded chain mechanism, with a key role of serine and threonine residues, by X-ray diffraction data on the subunit a of E. coli Fo. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Elementary analysis of massive samples at excitation of characteristic x-radiation by proton beams

    International Nuclear Information System (INIS)

    Altynov, V.A.; Blokhin, S.M.; Brazevich, Eh.; Brazevich, Ya.; Lyu Zaj Ik; Osetinskij, G.M.; Purehv, A.

    1982-01-01

    A simplified method is described for calculating the elementary composition in the massive samples in the case of the detection of the characteristic X-radiation emitted under the bombardment of the samples by a beam of protons. The method was experimentally verified by measuring the characteristic X-radiation from the elements with a known concentration entering the one-component and multi-component matrix. It was shown that within the experimental accuracy the discussed method gave results analogous to those obtained with the earlier used methods

  11. The SAMPLE experiment: Parity-violating electron scattering from the proton and deuteron

    International Nuclear Information System (INIS)

    Pitt, M.; Arrington, J.; Beck, D.; Beise, E.; Candell, E.; Cardman, L.; Carr, R.; Dodson, G.; Dow, K.; Duncan, F.; Farkhondeh, M.; Filippone, B.; Forest, T.; Gao, H.; Korsch, W.; Kowalski, S.; Lung, A.; McKeown, R.; Mohring, R.; Mueller, B.; Napolitano, J.; Simicevic, N.; Terburg, B.; Witkowski, M.

    1995-01-01

    Recent experimental evidence on nucleon structure has provided indications that some strange quark matrix elements can be comparable to those involving up and down quarks. The SAMPLE experiment will determine the strange magnetic form factor G s M at Q 2 =0.1 (GeV/c) 2 from a measurement of the asymmetry in the scattering of polarized electrons from the proton. The error on the extraction of G s M is ultimately limited by a theoretical uncertainty---the uncertain electroweak hadronic radiative correction to the axial form factor, R T=1 A . To address this issue, the collaboration is also approved to measure the asymmetry in parity-violating quasielastic electron scattering from the deuteron. The combination of the proton and deuteron measurements will yield a value of G s M that is almost completely free of the uncertainty in R T=1 A

  12. Pesticide residues in individual versus composite samples of apples after fine or coarse spray quality application

    NARCIS (Netherlands)

    Poulsen, M.; Wenneker, M.; Withagen, J.C.M.; Christensen, H.B.

    2012-01-01

    In this study, field trials on fine and coarse spray quality application of pesticides on apples were performed. The main objectives were to study the variation of pesticide residue levels in individual fruits versus composite samples, and the effect of standard fine spray quality application versus

  13. Identification and quantification of pesticide residues in water samples of Dhamrai Upazila, Bangladesh

    Science.gov (United States)

    Hasanuzzaman, M.; Rahman, M. A.; Salam, M. A.

    2017-10-01

    Being agricultural country, different types of pesticides are widely used in Bangladesh to prevent the crop losses due to pest attack which are ultimately drain to the water bodies. The present study was conducted to identify and quantify the organochlorine (DDT, DDE and DDD), organophosphorus (malathion, diazinon and chloropyrifos) and carbamate (carbaryl) residues in water samples of different sources from Dhamrai upazila of Bangladesh using high performance liquid chromatography (HPLC) equipped with ultra violate (UV) detector. Thirty water samples from fish pond, cultivated land and tube-well were collected in winter season to analyze the pesticide residues. Among the organophosphorus pesticides, malathion was present in seven water samples ranging from 42.58 to 922.8 μg/L, whereas diazinon was detected in water sample-8 (WS-8) and the concentration was 31.5 μg/L. None of the tested water samples was found to be contaminated with chlorpyrifos, carbaryl or DDT and its metabolites (DDE and DDD). Except for a tube-well water sample, concentrations of the detected residues are above the acceptable limit for human body as assigned by different organizations. To avoid the possible health hazards, the indiscriminate application of pesticides should be restricted and various substitute products like bio-pesticide should be introduced in a broad scale as soon as possible.

  14. An extension of command shaping methods for controlling residual vibration using frequency sampling

    Science.gov (United States)

    Singer, Neil C.; Seering, Warren P.

    1992-01-01

    The authors present an extension to the impulse shaping technique for commanding machines to move with reduced residual vibration. The extension, called frequency sampling, is a method for generating constraints that are used to obtain shaping sequences which minimize residual vibration in systems such as robots whose resonant frequencies change during motion. The authors present a review of impulse shaping methods, a development of the proposed extension, and a comparison of results of tests conducted on a simple model of the space shuttle robot arm. Frequency shaping provides a method for minimizing the impulse sequence duration required to give the desired insensitivity.

  15. [Determination of buprofezin, methamidophos, acephate, and triazophos residues in Chinese tea samples by gas chromatography].

    Science.gov (United States)

    Zhang, Shuiba; Yi, Jun; Ye, Jianglei; Zheng, Wenhui; Cai, Xueqin; Gong, Zhenbin

    2004-03-01

    A method has been developed for the simultaneous determination of buprofezin, methamidophos, acephate and triazophos residues in Chinese tea samples. The pesticide residues were extracted from tea samples with a mixture of ethyl acetate and n-hexane (50:50, v/v) at 45 degrees C. The extracts were subsequently treated with a column packed with 40 mg of active carbon by gradient elution with ethyl acetate and n-hexane. Buprofenzin and the three organophosphorus pesticides were analyzed by gas chromatography using a DB-210 capillary column and a nitrogen-phosphorus detector. The recoveries for spiked standards were 73.4%-96.9%. The relative standard deviations were all within 4.63%. The limits of quantitation (3sigma) in the tea samples were about 7.0-12.0 microg/kg.

  16. Analysis of Residual Nuclide in a ACM and ACCT of 100-MeV proton beamline By measurement X-ray Spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong-Min; Yun, Sang-Pil; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2015-10-15

    The proton beam is provides to users as various energy range from 20 MeV to 100 MeV. After protons generated from the ion source are accelerated to 100 MeV and irradiated to target through bending magnet and AC magnet. At this time, relatively high dose X-ray is emitted due to collision of proton and components of beamline. The generated X-ray is remaining after the accelerator is turned off and analyzing residual nuclides through the measurement of X-ray spectrum. Then identify the components that are the primary cause of residual nuclides are detected form the AC magnet(ACM) and associated components (ACCT). Analysis of the X-ray spectrum generated form the AC magnet(ACM) and AC current transformer(ACCT) of 100 MeV beamline according to the proton beam irradiation, most of the residual nuclides are identified it can be seen that emission in the stainless steel by beam loss.

  17. Hydrogen determination using secondary processes of recoil proton interaction with sample material

    International Nuclear Information System (INIS)

    Muminov, V.A.; Khajdarov, R.A.; Navalikhin, L.V.; Pardaev, Eh.

    1980-01-01

    Possibilities of hydrogen content determination in different materials according to secondary processes of interaction of recoil protons(irradiation in the field of fast neutrons) with sample material resulting in the appearance of characteristic X-ray irradiation are studied. Excitated irradiation is recorded with a detector placed in the protective screen and located at a certain distance from the object analyzed and neutron source. The method is tested taking as an example analysis of bromine-containing samples (30% Br, 0.5% H) and tungsten dioxide. The determination limit of hydrogen content constitutes 0.05% at confidence coefficient of 0.9. Neutron flux constituted 10 3 neutrons/cm 2 xs, the time of measurement being 15-20 minutes, the distance from the sample to the detector being 12-15 cm [ru

  18. Solid Phase Microextraction (SPME in Determination of Pesticide Residues in Soil Samples

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2011-01-01

    Full Text Available The basic principles and application possibilities of the methods based on solid phase microextraction (SPME in the analysis of pesticide residues in soil samples are presented in the paper. The most important experimental parameters which affect SPME efficacy inpesticide determination (type and thickness of microextraction fiber, duration of microextraction,temperature at which it is conducted, effect of addition of salts (the effect of efflorescence,temperature and time of desorption, the choice of optimal solvent for pesticide exctraction from the soil and the optimal number of extraction steps, as well as general guidelines for their optimization are also shown. In the end, current applications of SPMEmethods in the analysis of pesticide residues in soil samples are presented.

  19. Protonation of key acidic residues is critical for the K⁺-selectivity of the Na/K pump.

    Science.gov (United States)

    Yu, Haibo; Ratheal, Ian M; Artigas, Pablo; Roux, Benoît

    2011-09-11

    The sodium-potassium (Na/K) pump is a P-type ATPase that generates Na(+) and K(+) concentration gradients across the cell membrane. For each hydrolyzed ATP molecule, the pump extrudes three Na(+) and imports two K(+) by alternating between outward- and inward-facing conformations that preferentially bind K(+) or Na(+), respectively. Remarkably, the selective K(+) and Na(+) binding sites share several residues, and how the pump is able to achieve the selectivity required for the functional cycle is unclear. Here, free energy-perturbation molecular dynamics (FEP/MD) simulations based on the crystal structures of the Na/K pump in a K(+)-loaded state (E2·P(i)) reveal that protonation of the high-field acidic side chains involved in the binding sites is crucial to achieving the proper K(+) selectivity. This prediction is tested with electrophysiological experiments showing that the selectivity of the E2P state for K(+) over Na(+) is affected by extracellular pH.

  20. Presence of pesticide residues in water, sediment and biological samples taken from aquatic environments in Honduras

    International Nuclear Information System (INIS)

    Meyer, D.E.

    1999-01-01

    The objective of this study was to detect the presence of persistent pesticides in water, sediment and biological samples taken from aquatic environments in Honduras during the period 1995-98. Additionally, the LC 50 for 2 fungicides and 2 insecticides on post-larval Penaeus vannamei was determined in static water bioassays. A total of 80 water samples, 16 sediment samples and 7 biological samples (fish muscle tissue) were analyzed for detection of organochlorine and organophosphate pesticide residues. The results of sample analyses indicate a widespread contamination of Honduran continental and coastal waters with organochlorine pesticides. Most detections were of low ( 50 values and were therefore found to be much more toxic to the post-larval shrimp than the fungicides tridemorph and propiconazole. (author)

  1. An overview of the main foodstuff sample preparation technologies for tetracycline residue determination.

    Science.gov (United States)

    Pérez-Rodríguez, Michael; Pellerano, Roberto Gerardo; Pezza, Leonardo; Pezza, Helena Redigolo

    2018-05-15

    Tetracyclines are widely used for both the treatment and prevention of diseases in animals as well as for the promotion of rapid animal growth and weight gain. This practice may result in trace amounts of these drugs in products of animal origin, such as milk and eggs, posing serious risks to human health. The presence of tetracycline residues in foods can lead to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. In order to ensure food safety and avoid exposure to these substances, national and international regulatory agencies have established tolerance levels for authorized veterinary drugs, including tetracycline antimicrobials. In view of that, numerous sensitive and specific methods have been developed for the quantification of these compounds in different food matrices. One will note, however, that the determination of trace residues in foods such as milk and eggs often requires extensive sample extraction and preparation prior to conducting instrumental analysis. Sample pretreatment is usually the most complicated step in the analytical process and covers both cleaning and pre-concentration. Optimal sample preparation can reduce analysis time and sources of error, enhance sensitivity, apart from enabling unequivocal identification, confirmation and quantification of target analytes. The development and implementation of more environmentally friendly analytical procedures, which involve the use of less hazardous solvents and smaller sample sizes compared to traditional methods, is a rapidly increasing trend in analytical chemistry. This review seeks to provide an updated overview of the main trends in sample preparation for the determination of tetracycline residues in foodstuffs. The applicability of several extraction and clean-up techniques employed in the analysis of foodstuffs, especially milk and egg samples, is also thoroughly discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Effects of fretting fatigue on the residual stress of shot peened Ti-6Al-4V samples

    International Nuclear Information System (INIS)

    Martinez, S.A.; Sathish, S.; Blodgett, M.P.; Mall, S.; Namjoshi, S.

    2005-01-01

    X-ray diffraction residual stress measurement has been utilized as nondestructive tool for the characterization of fretting fatigue damage in shot peened samples of Ti-6Al-4V. Prior to fretting fatigue damage, compressive residual stresses were found to be uniform over the entire face of the sample and independent of the measurement direction. After fretting fatigue, inside and in the vicinity of the fretting damage zone large relaxation of compressive residual stress was observed. An anisotropic residual stress distribution has been observed in the fretting fatigue damaged region. Residual stress measurements in interrupted fretting fatigue experiments showed that the relaxation of residual stress increases as the number of fretting fatigue cycles increase. The results are discussed in the light of their importance in establishing X-ray diffraction residual stress measurement technique as a nondestructive tool to characterize fretting fatigue damage

  3. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Science.gov (United States)

    Ebert, M.; Worringen, A.; Benker, N.; Mertes, S.; Weingartner, E.; Weinbruch, S.

    2010-10-01

    During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI). Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated) aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN) were identified from the significant enrichment of particle groups in the ice residual (IR) samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and soot (C-O-S particles) by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates) observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2). In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3-8 nm sized primary particles (PbS, elemental Pb). C-O-S particles are present in the IR at an abundance of 17-27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9-15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent), and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the separate components contained within the individual particles.

  4. Enhanced Cleaning of Genesis Solar Wind Sample 61348 for Film Residue Removal

    Science.gov (United States)

    Allums, K. K.; Gonzalez, C. P.; Kuhlman, K. R.; Allton, J. H.

    2015-01-01

    The Genesis mission returned to Earth on September 8, 2004, experiencing a nonnominal reentry. During the recovery of the collector materials from the capsule, many of the collector fragments were placed on the adhesive protion of post-it notes to prevent the fragments from moving during transport back to Johnson Space Center. This unknowingly provided an additional contaminate that would prove difficult to remove with the limited chemistries allowed in the Genesis Curation Laboratory. Generally when collector material samples are prepared for allocation to PIs, the samples are cleaned front side only with Ultra-Pure Water (UPW) via megasonic dispersion to the collector surface to remove crash debris and contamination. While this cleaning method works well on samples that were not placed on post-its during recovery, it has caused movement of the residue on the back of the sample to be deposited on the front in at least two examples. Therefore, samples placed on the adhesive portion on post-it note, require enhanced cleaning methods since post-it residue has proved resistant to UPW cleaning.

  5. Experimental and theoretical study of the yields of residual product nuclei produced in thin targets irradiated by 100-2600 MeV protons

    CERN Document Server

    Titarenko, Y E; Karpikhin, E I

    2003-01-01

    The objective of the project is measurements and computer simulations of independent and cumulative yields of residual product nuclei in thin targets relevant as target materials and structure materials for hybrid accelerator-driven systems coupled to high-energy proton accelerators. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of hybrid facility targets as the total target activity, target 'poisoning', buildup of long-lived nuclides that, in turn, are to be transmuted, product nuclide (Po) alpha-activity, content of low-pressure evaporated nuclides (Hg), content of chemically-active nuclides that spoil drastically the corrosion resistance of the facility structure materials, etc. In view of the above, radioactive product nuclide yields from targets and structure materials were determined by an experiment using the ITEP U-10 proton accelerator in 51 irradiation runs for different thin targets: sup 1 sup 8 sup 2 sup , sup 1 sup 8 ...

  6. Residues of PCDDs and PCDFs in human milk samples in Ahmedabad, India

    Energy Technology Data Exchange (ETDEWEB)

    Kashyap, R.; Bhatnagar, V.; Sadhu, H.; Jhamb, N.; Karanjkar, R.; Saiyed, H. [National Inst. of Occupational Health, Ahmedabad (India)

    2004-09-15

    Polychlorinated dibenzo-p-dioxins (PCDDs) and Polychlorinated dibenzo furans (PCDFs) represent a class of organic environmental pollutants. They are unwanted byproduct of incineration, uncontrolled burning and certain industrial processes. They are persistent in nature and bioaccumulates through food chain. These are hazardous to human health and environment. The residues of these toxicants have been detected in human adipose tissue, blood and milk. WHO has coordinated two rounds of follow up studies on levels of PCDD/Fs and PCBs in human milk and the data shows a decreasing trend during the last 30 years. However, in India there is no data available on the exposure and residues of these contaminants. This study presents first time the levels of dioxin and furans in human milk samples collected from the Ahmedabad city in India.

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

    Science.gov (United States)

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

    2013-09-07

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

  8. A proton nuclear magnetic resonance investigation of proximal histidyl residues in human normal and abnormal hemoglobins: a probe for the heme pocket

    International Nuclear Information System (INIS)

    Takahashi, S.; Lin, A.K.L.; Ho, C.

    1982-01-01

    Proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate the conformations of proximal histidyl residues of human normal adult hemoglobin, hemoglobin Kempsey [K145(HC2) Tyr #betta# Asp], and hemoglobin McKees Rocks [K145(HC2) Tyr #betta# Term] around neutral pH in H 2 O at 27 0 C, all in the deoxy form. Two resonances that occur between 58 and 76 ppm downfield from the water proton signal have been assigned to the hyperfine shifted proximal histidyl NH-exchangeable protons of the J and K-chains of deoxyhemoglobin. These two resonances are sensitive to the quaternary state of hemoglobin, amino acid substitutions in the J 1 K 2 -subunit interface and in the carboxy-terminal region of the K-chain, and the addition of organic phosphates. The experimental results show that there are differences in the heme pockets among these four hemoglobins studied. The structural and dynamic information derived from the hyperfine shifted proximal histidyl NH-exchangeable proton resonances complement that obtained from the ferrous hyperfine shifted and exchangeable proton resonances of deoxyhemoglobin over the spectral region from 5 to 20 ppm downfield from H 2 O. The relationship between these findings and Perutz's stereochemical mechanism for the cooperative oxygenation of hemoglobin is discussed

  9. Veterinary antibiotic resistance, residues, and ecological risks in environmental samples obtained from poultry farms, Egypt.

    Science.gov (United States)

    Dahshan, Hesham; Abd-Elall, Amr Mohamed Mohamed; Megahed, Ayman Mohamed; Abd-El-Kader, Mahdy A; Nabawy, Ehab Elsayed

    2015-02-01

    In Egypt, poultry production constitutes one of the main sources of pollution with veterinary antibiotics (VAs) into the environment. About 80 % of meat production in Egypt is of poultry origin, and the potential environmental risks associated with the use of VAs in these farms have not yet been properly evaluated. Thus, the main purpose of this research was to evaluate the prevalence of antibiotic-resistant enteric key bacteria and the incidence of residual antibiotics in poultry farm environmental samples and to determine whether fertilizing soils with poultry litter from farms potentially brings ecological risks. From December 2011 to September 2012, a total of 225 litter, bird dropping, and water samples were collected from 75 randomly selected boiler poultry farms. A high prevalence of Escherichia coli (n = 179; 79.5 %) in contrast to the low prevalence of Salmonella spp. (n = 7; 3.1 %) was detected. Amongst E. coli isolates, serotypes O142:K86, O125:K70, O91:K, and O119:K69 were the most common. Meanwhile, Salmonella enterica serotypes emek and enteritidis were recovered. The antibiograms using the disc diffusion method revealed significantly more common resistant and multi-resistant isolates in broiler poultry farms. Residues of tetracycline and ciprofloxacin were detected at 2.125 and 1.401 mg kg(-1) mean levels, respectively, in environmental samples contaminated with E. coli-resistant strains by HPLC. The risk evaluations highlighted that tetracycline residues in poultry litter significantly display environmental risks with a hazard quotient value above 1 (1.64). Our study implies that ineffective implementation of veterinary laws which guide and guard against incorrect VA usage may potentially bring health and environmental risks.

  10. A method for assessing residual NAPL based on organic chemical concentrations in soil samples

    International Nuclear Information System (INIS)

    Feenstra, S.; Mackay, D.M.; Cherry, J.A.

    1991-01-01

    Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or >10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil chemical analyses indicate the presence of residual NAPL in the subsurface

  11. Study of Organochlorinated Pesticide Residues and Polychlorinated Biphenyls in Soil Samples

    Directory of Open Access Journals (Sweden)

    MSc. Vlora Gashi

    2013-12-01

    Full Text Available This paper presents and discusses the data obtained for organochlorinated pesticides and their residues in the soil samples of agricultural areas. Soil contamination is one of most important factors influencing the quality of agricultural products. Usage of heavy farm equipment, the land drainage, an exces­sive application of agrochemicals, emissions originating from mining, metallurgical, and chemical and coal power plants and transport, all generate a number of undesired substances (nitric and sulphur oxides, PAHs, heavy metals, pesticides, which after deposition in soil may influence crop quality. Thus, input of these contaminants into the environment should be carefully monitored. Levels of organochlorinated pesticides contamination were evaluated in agriculture areas that are in use. 10 soil samples were taken in agricultural areas  Plane of  Dugagjini , Kosovo. Representa­tive soil samples were collected from 0-30 cm top layer of the soil. In the analytical method we combined ultrasonic bath extraction and a Florisil column for samples clean-up. The analysis of the organochlorinated pesticides in soil samples was performed by gas chromatography technique using electron capture detector (GC/ECD. Optima-5 (low/mid polarity, 5% phenyl methyl siloxane 60 m x 0.33 mm x 0.25μm film capillary column was used for isolation and determination of organochlorinated pesticides. Low concentrations of organochlorinated pesticide and their metabolites were found in the studied samples. The presence of organochlorinated pesticides and their residues is probably resulting of their previous uses for agricultural purposes.

  12. Simultaneous Determination of TetracyclinesResidues in Bovine Milk Samples by Solid Phase Extraction and HPLC-FL Method

    Directory of Open Access Journals (Sweden)

    Mehra Mesgari Abbasi

    2011-06-01

    Full Text Available Introduction:Tetracyclines (TCs are widely used in animal husbandry and their residues in milk may resultinharmful effects on human. The aim of this study was to investigate the presence of TCs residues in various bovine milk samples from local markets of Ardabil, Iran. Methods:One hundred and fourteen pasteurized, sterilized and raw milk samples were collected from markets of Ardabil. Tetracycline, Oxytetracycline and Chlortetracycline (TCs residues extraction carried out by Solid Phase Extraction method. Determination of TCs residues were performed by high performance liquid chromatography (HPLC method using Fluorescence detector.Results: The mean of total TCs residues in all samples (114 samples was 97.6 ±16.9ng/g and that of pasteurized, sterilized and raw milk samples were 87.1 ± 17.7, 112.0 ± 57.3 and 154.0 ± 66.3ng/g respectively. Twenty five point four percent of the all samples, and24.4%, 30% and 28.6% of the pasteurized, sterilized and raw milk samples, respectively had higher TCs residues than the recommended maximum levels (100ng/g. Conclusion:This study indicates the presence of tetracycline residues more than allowed amount. Regulatory authorities should ensure proper withdrawal period before milking the animals and definite supervisions are necessary on application of these drugs.

  13. Roles of the β 146 histidyl residue in the molecular basis of the Bohr Effect of hemoglobin: A proton nuclear magnetic resonance study

    International Nuclear Information System (INIS)

    Busch, M.R.; Mace, J.E.; Ho, N.T.; Ho, Chien

    1991-01-01

    Assessment of the roles of the carboxyl-terminal β146 histidyl residues in the alkaline Bohr effect in human and normal adult hemoglobin by high-resolution proton nuclear magnetic resonance spectroscopy requires assignment of the resonances corresponding to these residues. By a careful spectroscopic study of human normal adult hemoglobin, enzymatically prepared des(His146β)-hemoglobin, and the mutant hemoglobins Cowtown (β146His → Leu) and York (β146His → Pro), the authors have resolved some of these conflicting results. By a close incremental variation of pH over a wide range in chloride-free 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid buffer, a single resonance has been found to be consistently missing in the proton nuclear magnetic resonance spectra of these hemoglobin variants. The results indicate that the contribution of the β146 histidyl residues is 0.52 H + /hemoglobin tetramer at pH 7.6, markedly less than 0.8 H + /hemoglobin tetramer estimated by study of the mutant hemoglobin Cowtown (β146His → Leu) by Shih and Perutz. They have found that at least two histidyl residues in the carbonmonoxy form of this mutant have pK values that are perturbed, and they suggest that these pK differences may in part account for this discrepancy. The results show that the pK values of β146 histidyl residues in the carbonmonoxy form of hemoglobin are substantially affected by the presence of chloride and other anions in the solvent, and thus, the contribution of this amino acid residue to the alkaline Bohr effect can be shown to vary widely in magnitude, depending on the solvent composition. These results demonstrate that the detailed molecular mechanisms of the alkaline Bohr effect are not unique but are affected both by the hemoglobin structure and by the interactions with the solvent components in which the hemoglobin molecule resides

  14. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Directory of Open Access Journals (Sweden)

    M. Ebert

    2011-03-01

    Full Text Available During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI. Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN were identified from the significant enrichment of particle groups in the ice residual (IR samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and carbonaceous material (C-O-S particles by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2. In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3–8 nm sized primary particles (PbS, elemental Pb. C-O-S particles are present in the IR at an abundance of 17–27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9–15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent, and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the sole knowledge of the main component of an individual particle.

  15. Important aspects of residue sampling in drilling dikes; Aspectos importantes para a amostragem de residuos em diques de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gilvan Ferreira da [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

    1989-12-31

    This paper describes the importance of sampling in the evaluation of physical and chemical properties of residues found in drilling dikes, considering the later selection of treatment methods or discard of these residues. We present the fundamental concepts of applied statistics, which are essential to the elaboration of sampling plans, with views of obtaining exact and precise results. Other types of samples are also presented, as well as sampling equipment and methods for storage and preservation of the samples. As a conclusion, we the example of the implementation of a sampling plan. (author) 3 refs., 9 figs., 3 tabs.

  16. Pesticide Residues in Commercial Lettuce, Onion, and Potato Samples From Bolivia—A Threat to Public Health?

    DEFF Research Database (Denmark)

    Skovgaard, Marlene; Renjel, Susana; Jensen, Olaf Chresten

    2017-01-01

    lettuce samples from La Paz were sampled on August 15, 2015 at a local market and screened for 283 pesticides. Residues of cypermethrin, chlorpyrifos, difenoconazol, or/and λ-cyhalothrin were detected in 50% of the lettuce samples, whereas no pesticides were found in potatoes and onions. In 20......% of the lettuce samples, the measurements were above the maximum residue limits, and 2 or 3 pesticides were identified simultaneously. Washing almost halved the pesticide levels, but still 20% of the samples showed measurements above the limits. No samples contained concentrations of pesticides which alone...

  17. Important aspects of residue sampling in drilling dikes; Aspectos importantes para a amostragem de residuos em diques de perfuracao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gilvan Ferreira da [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

    1990-12-31

    This paper describes the importance of sampling in the evaluation of physical and chemical properties of residues found in drilling dikes, considering the later selection of treatment methods or discard of these residues. We present the fundamental concepts of applied statistics, which are essential to the elaboration of sampling plans, with views of obtaining exact and precise results. Other types of samples are also presented, as well as sampling equipment and methods for storage and preservation of the samples. As a conclusion, we the example of the implementation of a sampling plan. (author) 3 refs., 9 figs., 3 tabs.

  18. Polycyclic Aromatic Hydrocarbon Residues in Serum Samples of Autopsied Individuals from Tennessee

    Directory of Open Access Journals (Sweden)

    Aramandla Ramesh

    2014-12-01

    Full Text Available This study reports the concentrations of Polycyclic Aromatic Hydrocarbons (PAHs in human blood sera samples (n = 650 obtained at autopsy from individuals who died of drug abuse, alcohol toxicity, homicide, suicide and other unknown causes. The analyzed samples from decedents revealed the presence of PAHs of which B(aP was the most predominant one, followed by benzo(bfluoranthene and benzo(kfluoranthene. The other PAHs detected sporadically and measured were benzo(g,h,iperylene, acenaphthene, anthracene, phenanthrene, and fluoranthene The mean concentrations of PAHs were greater in the twenties to fifties age groups compared to others. The PAH residue levels detected were high in African Americans compared to Caucasians, Asians, and Hispanics. It appears that environmental exposure, dietary intake and in some cases occupational exposure may have contributed to the PAH body burden. While the PAH residue concentrations measured fall within the range of those reported for healthy adults elsewhere, in isolated cases, the concentrations detected were high, calling the need for a reduction in PAH emissions and human biomonitoring studies for purposes of risk assessment.

  19. Clinical usefulness of limited sampling strategies for estimating AUC of proton pump inhibitors.

    Science.gov (United States)

    Niioka, Takenori

    2011-03-01

    Cytochrome P450 (CYP) 2C19 (CYP2C19) genotype is regarded as a useful tool to predict area under the blood concentration-time curve (AUC) of proton pump inhibitors (PPIs). In our results, however, CYP2C19 genotypes had no influence on AUC of all PPIs during fluvoxamine treatment. These findings suggest that CYP2C19 genotyping is not always a good indicator for estimating AUC of PPIs. Limited sampling strategies (LSS) were developed to estimate AUC simply and accurately. It is important to minimize the number of blood samples because of patient's acceptance. This article reviewed the usefulness of LSS for estimating AUC of three PPIs (omeprazole: OPZ, lansoprazole: LPZ and rabeprazole: RPZ). The best prediction formulas in each PPI were AUC(OPZ)=9.24 x C(6h)+2638.03, AUC(LPZ)=12.32 x C(6h)+3276.09 and AUC(RPZ)=1.39 x C(3h)+7.17 x C(6h)+344.14, respectively. In order to optimize the sampling strategy of LPZ, we tried to establish LSS for LPZ using a time point within 3 hours through the property of pharmacokinetics of its enantiomers. The best prediction formula using the fewest sampling points (one point) was AUC(racemic LPZ)=6.5 x C(3h) of (R)-LPZ+13.7 x C(3h) of (S)-LPZ-9917.3 x G1-14387.2×G2+7103.6 (G1: homozygous extensive metabolizer is 1 and the other genotypes are 0; G2: heterozygous extensive metabolizer is 1 and the other genotypes are 0). Those strategies, plasma concentration monitoring at one or two time-points, might be more suitable for AUC estimation than reference to CYP2C19 genotypes, particularly in the case of coadministration of CYP mediators.

  20. Efficiency of analytical and sampling-based uncertainty propagation in intensity-modulated proton therapy

    Science.gov (United States)

    Wahl, N.; Hennig, P.; Wieser, H. P.; Bangert, M.

    2017-07-01

    The sensitivity of intensity-modulated proton therapy (IMPT) treatment plans to uncertainties can be quantified and mitigated with robust/min-max and stochastic/probabilistic treatment analysis and optimization techniques. Those methods usually rely on sparse random, importance, or worst-case sampling. Inevitably, this imposes a trade-off between computational speed and accuracy of the uncertainty propagation. Here, we investigate analytical probabilistic modeling (APM) as an alternative for uncertainty propagation and minimization in IMPT that does not rely on scenario sampling. APM propagates probability distributions over range and setup uncertainties via a Gaussian pencil-beam approximation into moments of the probability distributions over the resulting dose in closed form. It supports arbitrary correlation models and allows for efficient incorporation of fractionation effects regarding random and systematic errors. We evaluate the trade-off between run-time and accuracy of APM uncertainty computations on three patient datasets. Results are compared against reference computations facilitating importance and random sampling. Two approximation techniques to accelerate uncertainty propagation and minimization based on probabilistic treatment plan optimization are presented. Runtimes are measured on CPU and GPU platforms, dosimetric accuracy is quantified in comparison to a sampling-based benchmark (5000 random samples). APM accurately propagates range and setup uncertainties into dose uncertainties at competitive run-times (GPU ≤slant {5} min). The resulting standard deviation (expectation value) of dose show average global γ{3% / {3}~mm} pass rates between 94.2% and 99.9% (98.4% and 100.0%). All investigated importance sampling strategies provided less accuracy at higher run-times considering only a single fraction. Considering fractionation, APM uncertainty propagation and treatment plan optimization was proven to be possible at constant time complexity

  1. Impact of recharge through residual oil upon sampling of underlying ground water

    International Nuclear Information System (INIS)

    Wise, W.R.; Chang, Chichung; Klopp, R.A.; Bedient, P.B.

    1991-01-01

    At an aviation gasoline spill site in Traverse City, Michigan, historical records indicate a positive correlation between significant rainfall events and increased concentrations of slightly soluble organic compounds in the monitoring wells of the site. To investigate the recharge effect on ground water quality due to infiltrating water percolating past residual oil and into the saturated zone, an in situ infiltration experiment was performed at the site. Sampling cones were set at various depths below a circular test area, 13 feet (4 meters) in diameter. Rainfall was simulated by sprinkling the test area at a rate sufficiently low to prevent runoff. The sampling cones for soil-gas and ground water quality were installed in the unsaturated and saturated zones to observed the effects of the recharge process. Infiltrated water was determined to have transported organic constituents of the residual oil, specifically benzene, toluene, ethylbenzene, and ortho-xylene (BTEX), into the ground water beneath the water table, elevating the aqueous concentrations of these constituents in the saturated zone. Soil-gas concentrations of the organic compounds in the unsaturated zone increased with depth and time after the commencement of infiltration. Reaeration of the unconfined aquifer via the infiltrated water was observed. It is concluded that water quality measurements are directly coupled to recharge events for the sandy type of aquifer with an overlying oil phase, which was studied in this work. Ground water sampling strategies and data analysis need to reflect the effect of recharge from precipitation on shallow, unconfined aquifers where an oil phase may be present

  2. Collision-Induced Dissociation of Deprotonated Peptides. Relative Abundance of Side-Chain Neutral Losses, Residue-Specific Product Ions, and Comparison with Protonated Peptides.

    Science.gov (United States)

    Liang, Yuxue; Neta, Pedatsur; Yang, Xiaoyu; Stein, Stephen E

    2018-03-01

    High-accuracy MS/MS spectra of deprotonated ions of 390 dipeptides and 137 peptides with three to six residues are studied. Many amino acid residues undergo neutral losses from their side chains. The most abundant is the loss of acetaldehyde from threonine. The abundance of losses from the side chains of other amino acids is estimated relative to that of threonine. While some amino acids lose the whole side chain, others lose only part of it, and some exhibit two or more different losses. Side-chain neutral losses are less abundant in the spectra of protonated peptides, being significant mainly for methionine and arginine. In addition to the neutral losses, many amino acid residues in deprotonated peptides produce specific negative ions after peptide bond cleavage. An expanded list of fragment ions from protonated peptides is also presented and compared with those of deprotonated peptides. Fragment ions are mostly different for these two cases. These lists of fragments are used to annotate peptide mass spectral libraries and to aid in the confirmation of specific amino acids in peptides. Graphical Abstract ᅟ.

  3. Pesticide residues analysis in water samples of Nagarpur and Saturia Upazila, Bangladesh

    Science.gov (United States)

    Hasanuzzaman, M.; Rahman, M. A.; Islam, M. S.; Salam, M. A.; Nabi, M. R.

    2018-03-01

    Pesticides used to protect the crops from pest attack in the agricultural fields pose harmful effect to the non-target organisms such as human and many other aquatic and terrestrial organisms either directly or indirectly through food chain. The present study was conducted to monitor a total of seven pesticide residues under organochlorine, organophosphorus and carbamate pesticides in three different sources of pond water, paddy field water and tube-well water from Nagarpur Upazila and paddy field water in the company of Dhaleshwari and Gazikhali river water from Saturia Upazila, Bangladesh. A total of 40 water samples were analyzed using high-performance liquid chromatography equipped with ultraviolet detector. Among the organophosphorus pesticides, diazinon was detected in eight water samples at a concentration ranging from 4.11 to 257.91 μg/l whereas, malathion was detected only in one water sample at a concentration of 84.64 μg/l and chlorpyrifos pesticide was also detected only in one water sample and the concentration was 37.3 μg/l. Trace amount of carbaryl was identified but it was below the detection limit. None of the tested water samples was found to be contaminated with DDT or its metabolites (DDE and DDD). The water samples contaminated with the suspected pesticides were above the acceptable limit except for the fish pond samples of Sahabatpur and Dubaria union. To control the misuse of pesticides and to reduce the possible health risk, appropriate control systems of pests such as integrated pest management system should be implemented immediately by the authorities of the country.

  4. Determination of five nitroimidazole residues in artificial porcine muscle tissue samples by capillary electrophoresis.

    Science.gov (United States)

    Lin, Yingyun; Su, Yan; Liao, Xiulin; Yang, Na; Yang, Xiupei; Choi, Martin M F

    2012-01-15

    A capillary electrophoresis (CE) method with ultraviolet detection has been developed for simultaneous detection and quantification of five nitroimidazoles including benzoylmetronidazole, dimetridazole, metronidazole, ronidazole, and secnidazole in porcine muscles. Nitroimidazoles in samples were extracted by ethyl acetate with subsequent clean-up by a strong cation exchange solid phase extraction column. The clean extracts were subjected to CE separation with optimal experimental conditions: pH 3.0 running buffer containing 25mM sodium phosphate and 0.10mM tetrabutylammonium bromide, 5s hydrodynamic injection at 0.5psi and 28kV separation voltage. The nitroimidazoles could be monitored and detected at 320nm within 18min. The limits of detection were below 1.0μg/kg and limits of quantification were lower than 3.2μg/kg for all nitroimidazoles in the muscle samples. The recoveries and relative standard deviations were 85.4-96.0, 83.5-92.5, 1.3-3.9, and 1.1-4.2%, respectively for the intra-day and inter-day analyses. The proposed CE method has been successfully applied to determine nitroimidazoles in artificial porcine muscle samples with good accuracy and recovery, demonstrating that it has potential for detection and quantification of multi-nitroimidazole residue in real muscle samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Review of sample preparation techniques for the analysis of pesticide residues in soil.

    Science.gov (United States)

    Tadeo, José L; Pérez, Rosa Ana; Albero, Beatriz; García-Valcárcel, Ana I; Sánchez-Brunete, Consuelo

    2012-01-01

    This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination. The optimization of sample preparation is a very important part of the method development that can reduce the analysis time, the amount of solvent, and the size of samples. This review considers all aspects of sample preparation, including extraction and cleanup. Classical extraction techniques, such as shaking, Soxhlet, and ultrasonic-assisted extraction, and modern techniques like pressurized liquid extraction, microwave-assisted extraction, solid-phase microextraction and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) are reviewed. The different cleanup strategies applied for the purification of soil extracts are also discussed. In addition, the application of these techniques to environmental studies is considered.

  6. Headspace Solid Phase Microextraction in Pesticide Residues Analysis: 2. Apple Samples

    Directory of Open Access Journals (Sweden)

    Jelena Milinović

    2007-01-01

    Full Text Available Headspace solid phase microextraction method (HS/SPME, optimised previously for pesticide water solutions, was applied to trace residues of the pesticides chlorpyrifos, fenthion and bifenthrin in apple samples. One-hour extraction procedure was performed at 60oC extraction temperature. Nonpolar polydimethyl siloxane (PDMS fiber was used. Detection and quantification were carried out by gas chromatography/mass spectrometry (GC/MS. A non-pesticide treated apple sample was fortified with the pesticides over a 0.025-1.25 mg/kg concentration range in order to determine analytical parameters of the method applied. Linearity with regression coefficient (R values higher than 0.99 were obtained over the whole concentration range investigated for chlorpyrifos and fenthion, while linear dependence was observed in the 0.1-1.25 mg/kg range for bifenthrin. Relative recovery values for samples fortified at different levels were in the 56.68-82.91% range. Limit of detection (LOD values were determined as follows: 0.014 mg/kg for chlorpyrifos, 0.021 mg/kg for fenthion and 0.053 mg/kg for bifenthrin. Relative standard deviation (RSD values obtained for multiple analysis of the sample fortified at 0.6 mg/kg level were not higher than 20%.

  7. Investigation of organochlorine pesticide residues in samples of 40 nursing mothers residing in Tehran

    Directory of Open Access Journals (Sweden)

    Afshar M

    1997-09-01

    Full Text Available Organochlorine pesticides are a group of persistant compounds which have been used for a long time. Due to their stability, some of them such as DDT, BHC and their derivatives are still used in the areas with malaria epidemic condition, hence the chance of food contamination always exists. The present survey demonstrated that human milk is one of the best indicator substances in monitoring the environment and human body contamination by organochlorine compounds. We studied the level of residues in the milk of nursing mothers who could be exposed to these compounds through food chain in their contaminated environment. In this investigation, we collected 40 samples from the nursing mothers of two hospitals located in the north and south of Tehran. Detection was carried out by Gas chromatography (GC with 3% OV17 column and Ni63 ECD (Electron Capture Detector. Reference substances were obtained from WHO. Results are discussed in the text.

  8. Comparison of Methods for Bifenthrin Residues Determination in Fermented Wheat Samples

    Directory of Open Access Journals (Sweden)

    Tijana Đorđević

    2012-01-01

    Full Text Available Efficiency of three different sample preparation methods for GC/MS determinationof bifenthrin residues in wheat (Triticum spelta samples fermented by Lactobacillusplantarum was tested. The first method was based on a methanol:acetone=1:1 extractionfolowed by a purification on columns containing mixture of aluminium oxide and activatedcharcoal slurry-packed and eluted with dichlormethane, the second was based onmethanol:acetone=1:1 extraction folowed by the purification on florisil column and elutionby ethil acetate:acetone=4:1, while the third tested method was based on a combinationof the first two mentioned methods, thus methanol:acetone=1:1 extraction and clean-upthrought columns filled with a mixture of aluminum oxide and activated charcoal slurrypackedand eluted with ethil acetate:acetone=4:1. The second method was the most effectivefor obtaining satisfactory recoveries for bifenthrin in a range of 79-83% for four fortificationlevels, with good reproducibility i.e. RSD% in a range of 2.2-7.4%. The chosen methodwas further optimized by assessing the optimum volume of elution solvent used duringthe clean-up procedures. The highest recovery of 82.1% was obtained after elution with25 ml of solvent. Overall, two-step extraction with 25 ml of methanol:acetone=1:1 solventmix for 30 min, followed by clean-up procedure through a glass column with florisil coupledwith elution with 25 ml of ethyl acetate: acetone=4:1, allows simple, efficient and reliableGC/MS detection of bifenthrin residues from wheat grain fermented by L. plantarum.

  9. Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

    Science.gov (United States)

    Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

    1976-01-01

    Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

  10. Unexpected alignment patterns in high-j intruder bands evidence for a strong residual neutron proton interaction?

    International Nuclear Information System (INIS)

    Wyss, R.; Johnson, A.; Royal Inst. of Tech., Stockholm

    1990-01-01

    The alignment of h 11/12 protons in νi 13/2 intruder bands in mass A = 130 region is investigated. The lack of a clear h 11/12 band crossing is compared with the alignment pattern of i 13/2 neutrons in πi 13/2 intruder bands in mass A = 180 region. The very smooth rise in angular momentum in the intruder bands is related to a possible neutron proton interaction between the single intruder orbital and the aligned two-quasiparticle configuration. 36 refs., 3 figs

  11. Proton NMR relaxivity of blood samples in the presence of some gadolinium and dysprosium compounds

    International Nuclear Information System (INIS)

    Coroiu, I.; Darabont, Al.; Bogdan, M.

    1999-01-01

    The use of some new compounds in MRI tissue and blood characterisation based on nuclear spin relaxation time measurements cannot be sustained until the molecular sources of these variations are understood. Tissues and blood are complex molecular systems with complex NMR properties. A better comprehension of the molecular basis of relaxation offers the possibility to predict the changes expected for a given pathology. The purpose of this contribution is to evidence the different relaxation characteristics of some gadolinium and dysprosium compounds in the presence and absence of the blood and to give a possible explanation about the molecular processes that cause occurrence of changes. Some gadolinium and dysprosium compounds such as: Gd-CIT (gadolinium citrate), Dy-DTPA (DTPA-diethylenetriamine pentaacetic acid), iron oxide - gadolinium oxide (or dysprosium oxide)- dextran complexes were prepared. The longitudinal T 1 -1 and transverse T 2 -1 'relaxation rates' measurements have been carried out as a function of molar concentrations. All measurements have been made at room temperature (about 25 deg.C) and the proton Larmor frequency ν o = 90 MHz. The pulsed NMR spectrometer utilised was a commercial Bruker SXP4/100 spectrometer. Transverse relaxation rate measurements have been made using the Carr-Purcell method, while longitudinal relaxation rate measurements using the inversion recovery pulse sequence, 180 angle-τ-90 angle. The accuracy was about 2-3% for the longitudinal relaxation rates and about 5-7% for the transverse relaxation rates. R 1 and R 2 relaxivities, in mM -1 s -1 were determined from the least square determination of the slopes of plots 1/T 1,2 versus compound molar concentration, using at least five independent measurements at several concentrations between 0 and 2 mM. Increased R 2 relaxivity observed for dysprosium compounds in the blood presence can be explained by PRE effect. The largest gain in R 2 relaxivity seems to imply a noncovalent

  12. Optimization of Region-of-Interest Sampling Strategies for Hepatic MRI Proton Density Fat Fraction Quantification

    Science.gov (United States)

    Hong, Cheng William; Wolfson, Tanya; Sy, Ethan Z.; Schlein, Alexandra N.; Hooker, Jonathan C.; Dehkordy, Soudabeh Fazeli; Hamilton, Gavin; Reeder, Scott B.; Loomba, Rohit; Sirlin, Claude B.

    2017-01-01

    BACKGROUND Clinical trials utilizing proton density fat fraction (PDFF) as an imaging biomarker for hepatic steatosis have used a laborious region-of-interest (ROI) sampling strategy of placing an ROI in each hepatic segment. PURPOSE To identify a strategy with the fewest ROIs that consistently achieves close agreement with the nine-ROI strategy. STUDY TYPE Retrospective secondary analysis of prospectively acquired clinical research data. POPULATION A total of 391 adults (173 men, 218 women) with known or suspected NAFLD. FIELD STRENGTH/SEQUENCE Confounder-corrected chemical-shift-encoded 3T MRI using a 2D multiecho gradientrecalled echo technique. ASSESSMENT An ROI was placed in each hepatic segment. Mean nine-ROI PDFF and segmental PDFF standard deviation were computed. Segmental and lobar PDFF were compared. PDFF was estimated using every combinatorial subset of ROIs and compared to the nine-ROI average. STATISTICAL TESTING Mean nine-ROI PDFF and segmental PDFF standard deviation were summarized descriptively. Segmental PDFF was compared using a one-way analysis of variance, and lobar PDFF was compared using a paired t-test and a Bland–Altman analysis. The PDFF estimated by every subset of ROIs was informally compared to the nine-ROI average using median intraclass correlation coefficients (ICCs) and Bland–Altman analyses. RESULTS The study population’s mean whole-liver PDFF was 10.1±8.9% (range: 1.1–44.1%). Although there was no significant difference in average segmental (P=0.452) or lobar (P=0.154) PDFF, left and right lobe PDFF differed by at least 1.5 percentage points in 25.1% (98/391) of patients. Any strategy with ≥ 4 ROIs had ICC >0.995. 115 of 126 four-ROI strategies (91%) had limits of agreement (LOA) 0.995, and 2/36 (6%) of two-ROI strategies and 46/84 (55%) of three-ROI strategies had LOA <1.5%. DATA CONCLUSION Four-ROI sampling strategies with two ROIs in the left and right lobes achieve close agreement with nine-ROI PDFF. Level of

  13. Optimization of region-of-interest sampling strategies for hepatic MRI proton density fat fraction quantification.

    Science.gov (United States)

    Hong, Cheng William; Wolfson, Tanya; Sy, Ethan Z; Schlein, Alexandra N; Hooker, Jonathan C; Fazeli Dehkordy, Soudabeh; Hamilton, Gavin; Reeder, Scott B; Loomba, Rohit; Sirlin, Claude B

    2018-04-01

    Clinical trials utilizing proton density fat fraction (PDFF) as an imaging biomarker for hepatic steatosis have used a laborious region-of-interest (ROI) sampling strategy of placing an ROI in each hepatic segment. To identify a strategy with the fewest ROIs that consistently achieves close agreement with the nine-ROI strategy. Retrospective secondary analysis of prospectively acquired clinical research data. A total of 391 adults (173 men, 218 women) with known or suspected NAFLD. Confounder-corrected chemical-shift-encoded 3T MRI using a 2D multiecho gradient-recalled echo technique. An ROI was placed in each hepatic segment. Mean nine-ROI PDFF and segmental PDFF standard deviation were computed. Segmental and lobar PDFF were compared. PDFF was estimated using every combinatorial subset of ROIs and compared to the nine-ROI average. Mean nine-ROI PDFF and segmental PDFF standard deviation were summarized descriptively. Segmental PDFF was compared using a one-way analysis of variance, and lobar PDFF was compared using a paired t-test and a Bland-Altman analysis. The PDFF estimated by every subset of ROIs was informally compared to the nine-ROI average using median intraclass correlation coefficients (ICCs) and Bland-Altman analyses. The study population's mean whole-liver PDFF was 10.1 ± 8.9% (range: 1.1-44.1%). Although there was no significant difference in average segmental (P = 0.452) or lobar (P = 0.154) PDFF, left and right lobe PDFF differed by at least 1.5 percentage points in 25.1% (98/391) of patients. Any strategy with ≥4 ROIs had ICC >0.995. 115 of 126 four-ROI strategies (91%) had limits of agreement (LOA) 0.995, and 2/36 (6%) of two-ROI strategies and 46/84 (55%) of three-ROI strategies had LOA <1.5%. Four-ROI sampling strategies with two ROIs in the left and right lobes achieve close agreement with nine-ROI PDFF. 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:988-994. © 2017 International Society for Magnetic Resonance

  14. Evidence for a Proton Transfer Network and a Required Persulfide-Bond-Forming Cysteine Residue in Ni-Containing Carbon Monoxide Dehydrogenases

    International Nuclear Information System (INIS)

    Eun Jin Kim; Jian Feng; Bramlett, Matthew R.; Lindahl, Paul A.

    2004-01-01

    OAK-B135 Carbon monoxide dehydrogenase from Moorella thermoacetica catalyzes the reversible oxidation of CO to CO2 at a nickel-iron-sulfur active-site called the C-cluster. Mutants of a proposed proton transfer pathway and of a cysteine residue recently found to form a persulfide bond with the C-cluster were characterized. Four semi-conserved histidine residues were individually mutated to alanine. His116 and His122 were essential to catalysis, while His113 and His119 attenuated catalysis but were not essential. Significant activity was ''rescued'' by a double mutant where His116 was replaced by Ala and His was also introduced at position 115. Activity was also rescued in double mutants where His122 was replaced by Ala and His was simultaneously introduced at either position 121 or 123. Activity was also ''rescued'' by replacing His with Cys at position 116. Mutation of conserved Lys587 near the C-cluster attenuated activity but did not eliminate it. Activity was virtually abolished in a double mutant where Lys587 and His113 were both changed to Ala. Mutations of conserved Asn284 also attenuated activity. These effects suggest the presence of a network of amino acid residues responsible for proton transfer rather than a single linear pathway. The Ser mutant of the persulfide-forming Cys316 was essentially inactive and displayed no EPR signals originating from the C-cluster. Electronic absorption and metal analysis suggests that the C-cluster is absent in this mutant. The persulfide bond appears to be essential for either the assembly or stability of the C-cluster, and/or for eliciting the redox chemistry of the C-cluster required for catalytic activity

  15. Experimental and theoretical study of the residual nuclide production in 40-2600 MeV proton-irradiated thin targets of ads structure materials

    International Nuclear Information System (INIS)

    Titarenko, Yu.E.; Batyaev, V.F.; Belonozhenko, A.A.; Borovlev, S.P.; Butko, M.A.; Florya, S.N.; Pavlov, K.V.; Rogov, V.I.; Tikhonov, R.S.; Titarenko, A.Yu.; Zhivun, V.M.

    2011-10-01

    The Project is aimed at experimental and theoretical studying the independent and cumulative yields of residual radioactive nuclei produced in high-energy proton-irradiated structure materials intended for constructing the high-power Accelerator-Driven Systems (ADS) with a high-current proton accelerator. The Project is an extension of the researches carried out earlier under the ISTC Projects #017, #839, and #2002 which provided more 10000 residual nuclide production cross sections mainly in materials intended to use as target materials of the ADS. This Project includes 57 measurement runs carried out using the 97 targets made only of the ADS structural materials of both monoisotopic ( 56 Fe, 93 Nb, 181 Ta) and natural ( nat Cr, nat Ni, nat W) compositions within minutely fractionated proton energy range, namely, at 0.04, 0.07, 0.1, 0.15, 0.25, 0.4, 0.6, 0.8, 1.2, 1.6 and 2.6GeV. All the targets were irradiated using the ITEP U-10 proton synchrotron. The experimental nuclide yields are determined by the direct γ-spectrometry and α-spectrometry methods. As a result, 3839 cumulative and independent yields of residual β-radioactive product nuclei with lifetimes range from 6 minutes to 10 years as well as 12 cumulative yields of α- radioactive 148 Gd whose lifetime is 74.6 years have been measured. Besides, the cross sections for the 27 Al(p,x) 22 Na , 27 Al(p,x) 24 Na and 27 Al(p,x) 7 Be monitor reactions have been measured at the same proton energies with the use of the current transformer technique. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60 Co γ-line. The experimental γ-spectra were processed by the GENIE2000 code. The γ-lines were identified, and the cross sections calculated, by the ITEP-developed SIGMA code using the PCNUDAT database. The proton fluence was monitored by the 27 Al(p,x) 22 Na reaction. Measurement data have been compared with the calculation results of the BERTINI and ISABEL models of MCNPX code, CEM03.02, INCL 4.2, INCL4

  16. Evaluating organochlorine pesticide residues in the aquatic environment of the Lake Naivasha River basin using passive sampling techniques.

    Science.gov (United States)

    Abbasi, Yasser; Mannaerts, Chris M

    2018-05-18

    Passive sampling techniques can improve the discovery of low concentrations by continuous collecting the contaminants, which usually go undetected with classic and once-off time-point grab sampling. The aim of this study was to evaluate organochlorine pesticide (OCP) residues in the aquatic environment of the Lake Naivasha river basin (Kenya) using passive sampling techniques. Silicone rubber sheet and Speedisk samplers were used to detect residues of α-HCH, β-HCH, γ-HCH, δ-HCH, heptachlor, aldrin, heptachlor epoxide, pp-DDE, endrin, dieldrin, α-endosulfan, β-endosulfan, pp-DDD, endrin aldehyde, pp-DDT, endosulfan sulfate, and methoxychlor in the Malewa River and Lake Naivasha. After solvent extraction from the sampling media, the residues were analyzed using gas chromatography electron capture detection (GC-ECD) for the OCPs and gas chromatography-mass spectrometry (GC-MS) for the PCB reference compounds. Measuring the OCP residues using the silicone rubber samplers revealed the highest concentration of residues (∑OCPs of 81 (± 18.9 SD) μg/L) to be at the Lake site, being the ultimate accumulation environment for surficial hydrological, chemical, and sediment transport through the river basin. The total OCP residue sums changed to 71.5 (± 11.3 SD) μg/L for the Middle Malewa and 59 (± 12.5 SD) μg/L for the Upper Malewa River sampling sites. The concentration sums of OCPs detected using the Speedisk samplers at the Upper Malewa, Middle Malewa, and the Lake Naivasha sites were 28.2 (± 4.2 SD), 31.3 (± 1.8 SD), and 34.2 (± 6.4 SD) μg/L, respectively. An evaluation of the different pesticide compound variations identified at the three sites revealed that endosulfan sulfate, α-HCH, methoxychlor, and endrin aldehyde residues were still found at all sampling sites. However, the statistical analysis of one-way ANOVA for testing the differences of ∑OCPs between the sampling sites for both the silicone rubber sheet and Speedisk samplers

  17. Effect of thermal exposure on the residual stress relaxation in a hardened cylindrical sample under creep conditions

    Science.gov (United States)

    Radchenko, V. P.; Saushkin, M. N.; Tsvetkov, V. V.

    2016-05-01

    This paper describes the effect of thermal exposure (high-temperature exposure) ( T = 675°C) on the residual creep stress relaxation in a surface hardened solid cylindrical sample made of ZhS6UVI alloy. The analysis is carried out with the use of experimental data for residual stresses after micro-shot peening and exposures to temperatures equal to T = 675°C during 50, 150, and 300 h. The paper presents the technique for solving the boundary-value creep problem for the hardened cylindrical sample with the initial stress-strain state under the condition of thermal exposure. The uniaxial experimental creep curves obtained under constant stresses of 500, 530, 570, and 600 MPa are used to construct the models describing the primary and secondary stages of creep. The calculated and experimental data for the longitudinal (axial) tensor components of residual stresses are compared, and their satisfactory agreement is determined.

  18. A method for the determination of residual beta activity in drinking water samples

    Energy Technology Data Exchange (ETDEWEB)

    Idoeta, R. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)], E-mail: raquel.idoeta@ehu.es; Herranz, M.; Abelairas, A.; Legarda, F. [Dpto. Ingenieria Nuclear y Mecanica de Fluidos, E. T. S. Ingenieria de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n. 48013 Bilbao (Spain)

    2007-09-15

    The determination of residual beta activity in drinking water is usually needed in most monitoring programs. In this work a procedure for its determination is described and expressions for the calculations of detection limits and uncertainties are proposed.

  19. A method for the determination of residual beta activity in drinking water samples

    International Nuclear Information System (INIS)

    Idoeta, R.; Herranz, M.; Abelairas, A.; Legarda, F.

    2007-01-01

    The determination of residual beta activity in drinking water is usually needed in most monitoring programs. In this work a procedure for its determination is described and expressions for the calculations of detection limits and uncertainties are proposed

  20. Experimental and theoretical studies of the yields of residual product nuclei produced in thin Pb and Bi targets irradiated by 40 - 2600 MeV protons

    International Nuclear Information System (INIS)

    Titarenko, Yu. E.; Batyaev, V.F.; Karpikhin, E.I.; Zhivun, V.M.; Ignatyuk, A.V.; Lunev, V.P.; Titarenko, N.N.; Shubin, Yu.N.; Barashenkov, V.S.

    2009-10-01

    The Project is aimed at experimental determining and computer-aided theoretical simulating the independent and cumulative yields of residual radioactive product nuclei in high-energy protonirradiated thin targets made of high-isotopic and natural lead ( 206 Pb, 207 Pb, 208 PB, natPb) and bismuth ( 209 Bi) that are the most probable choice to be the target materials in the acceleratordriven (hybrid) systems (ADS) coupled to a high-current proton accelerator. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of the hybrid facility targets as the total target activity, the target 'poisoning', the buildup of long-lived nuclides, the α-activity, the content of low-pressure evaporated nuclides (Hg), the content of the chemically-active nuclides that drastically spoil the corrosion resistance of the facility structure materials, etc. In view of the above, the radioactive product nuclide yields from targets materials were experimentally determined using the ITEP U-10 proton accelerator in 55 measurement runs using the monoisotopic and natural lead ( 206 Pb, 207 Pb, 208 PB, natPb) and bismuth ( 209 Bi) targets within the proton energy range fractionated minutely, namely at 0.04, 0.07, 0.10, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV to cover the entire range of the internuclear hadron cascading. As a result, 5972 cumulative and independent yields of residual radioactive product nuclei, whose lifetimes range from 8 minutes to 32 years, have been measured. Besides, the cross sections for the 27 Al(p,x) 24 Na and 27 Al(p,x)7Be monitor reactions have been measured at the same proton energies together with the 27 Al(n,p) 27 Mg reaction rate that characterizes the neutron background contributions in each experiment. The experimental nuclide yields are determined by the direct γ-spectrometry method. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60 Co γ-line. The experimental γ-spectra are processed by

  1. Mannobiose Binding Induces Changes in Hydrogen Bonding and Protonation States of Acidic Residues in Concanavalin A As Revealed by Neutron Crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Gerlits, Oksana O. [UT/ORNL; Coates, Leighton [Biology; Woods, Robert J. [Complex; Kovalevsky, Andrey [Biology

    2017-08-30

    Plant lectins are carbohydrate-binding proteins with various biomedical applications. Concanavalin A (Con A) holds promise in treating cancerous tumors. To better understand the Con A carbohydrate binding specificity, we obtained a room-temperature neutron structure of this legume lectin in complex with a disaccharide Manα1–2Man, mannobiose. The neutron structure afforded direct visualization of the hydrogen bonding between the protein and ligand, showing that the ligand is able to alter both protonation states and interactions for residues located close to and distant from the binding site. An unprecedented low-barrier hydrogen bond was observed forming between the carboxylic side chains of Asp28 and Glu8, with the D atom positioned equidistant from the oxygen atoms having an O···D···O angle of 101.5°.

  2. Detection of pesticides residues in water samples from organic and conventional paddy fields of Ledang, Johor, Malaysia

    Science.gov (United States)

    Abdullah, Md Pauzi; Othman, Mohamed Rozali; Ishak, Anizan; Nabhan, Khitam Jaber

    2016-11-01

    Pesticides have been used extensively by the farmers in Malaysia during the last few decades. Sixteen water samples, collected from paddy fields both organic and conventional, from Ledang, Johor, were analyzed to determine the occurrence and distribution of organochlorine (OCPs) and organophosphorus (OPPs) pesticide residues. GC-ECD instrument was used to identify and determine the concentrations of these pesticide residues. Pesticide residues were detected in conventional fields in the range about 0.036-0.508 µg/L higher than detected in organic fields about 0.015-0.428 µg/L. However the level of concentration of pesticide residues in water sample from both paddy fields are in the exceed limit for human consumption, according to European Economic Commission (EEC) (Directive 98/83/EC) at 0.1 µg/L for any pesticide or 0.5 µg/L for total pesticides. The results that the organic plot is still contaminated with pesticides although pesticides were not use at all in plot possibly from historical used as well as from airborne contamination.

  3. Proton Induced X-Rays Emission (PIXE) and Atomic Absorption Spectrometry (AAS) applied in the environmental sample analysis

    International Nuclear Information System (INIS)

    Popescu, Ion V.; Iordan, M.; Stihi, C.; Bancuta, A.; Dima, G.; Busuioc, G.; Ciupina, V.; Belc, M.; Badica, T.

    2003-01-01

    The aim of this work is to determine the elemental composition of tree leaves using Proton-Induced X-Rays Emission (PIXE) and Atomic Absorption Spectrophotometry (AAS) methods. By PIXE Spectrometry we identified and determined the concentration of S, Cl, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu Zn, As, Br, Sr and by AAS method the concentration of elements: Cr, Mn, Fe, Co, Cu, Zn, Se, Cd. Pb was identified in only 2 samples from 29. For tree leave samples collected at a large distance to the polluting source the Sr concentration decreased and the Mg, Ca, Se, Zn and Fe concentrations increased. Also, we can observe a small affinity of these leaves for the environmental Pb which was detected for two samples at a small distance to polluting source. (authors)

  4. Investigation of hydrophobic substrates for solution residue analysis utilizing an ambient desorption liquid sampling-atmospheric pressure glow discharge microplasma.

    Science.gov (United States)

    Paing, Htoo W; Marcus, R Kenneth

    2018-03-12

    A practical method for preparation of solution residue samples for analysis utilizing the ambient desorption liquid sampling-atmospheric pressure glow discharge optical emission spectroscopy (AD-LS-APGD-OES) microplasma is described. Initial efforts involving placement of solution aliquots in wells drilled into copper substrates, proved unsuccessful. A design-of-experiment (DOE) approach was carried out to determine influential factors during sample deposition including solution volume, solute concentration, number of droplets deposited, and the solution matrix. These various aspects are manifested in the mass of analyte deposited as well as the size/shape of the product residue. Statistical analysis demonstrated that only those initial attributes were significant factors towards the emission response of the analyte. Various approaches were investigated to better control the location/uniformity of the deposited sample. Three alternative substrates, a glass slide, a poly(tetrafluoro)ethylene (PTFE) sheet, and a polydimethylsiloxane (PDMS)-coated glass slide, were evaluated towards the microplasma analytical performance. Co-deposition with simple organic dyes provided an accurate means of determining the location of the analyte with only minor influence on emission responses. The PDMS-coated glass provided the best performance by virtue of its providing a uniform spatial distribution of the residue material. This uniformity yielded an improved limits of detection by approximately 22× for 20 μL and 4 x for 2 μL over the other two substrates. While they operate by fundamentally different processes, this choice of substrate is not restricted to the LS-APGD, but may also be applicable to other AD methods such as DESI, DART, or LIBS. Further developments will be directed towards a field-deployable ambient desorption OES source for quantitative analysis of microvolume solution residues of nuclear forensics importance.

  5. Proton spectroscopy of the thalamus in a homogeneous sample of patients with easy-to-control juvenile myoclonic epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Claudia da Costa; Valente, Kette Dualibi Ramos; Fiore, Lia Arno; Otaduy, Maria Concepcion Garcia, E-mail: claudia.leite@hc.fm.usp.br [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

    2017-09-15

    Objective: Juvenile myoclonic epilepsy (JME) is a subtype of genetically determined generalized epilepsy that does not present abnormalities on conventional magnetic resonance imaging. The aim of this study was to identify metabolic alterations in the thalamus in a clinically homogeneous sample of patients with easy-to-control JME, using short-echo time proton magnetic resonance spectroscopy (MRS). Materials and Methods: We performed single-voxel (2 cm × 2 cm × 2 cm), short-echo time (TE = 35 ms) proton MRS of the thalamus in 21 patients with JME and in 14 healthy age-matched controls. We quantified N-acetylaspartate (NAA), total NAA, creatine (Cr), choline, and myo-inositol (MI), as well as the sum of glutamate and glutamine signals, all scaled to internal water content, and we calculated metabolite ratios using Cr as a reference. Values of p < 0.05 were considered significant. Results: The MI level and the MI/Cr ratio were significantly lower in the thalami of patients diagnosed with JME than in those of the controls. Other metabolites and their ratios did not differ significantly between the two groups. Conclusion: In our sample of 21 JME patients, we identified lower levels of MI in the thalamus. No significant abnormalities were observed in the concentrations or ratios of other metabolites. (author)

  6. pH-induced conformational change of IscU at low pH correlates with protonation/deprotonation of two conserved histidine residues.

    Science.gov (United States)

    Dai, Ziqi; Kim, Jin Hae; Tonelli, Marco; Ali, Ibrahim K; Markley, John L

    2014-08-19

    IscU, the scaffold protein for the major iron-sulfur cluster biosynthesis pathway in microorganisms and mitochondria (ISC pathway), plays important roles in the formation of [2Fe-2S] and [4Fe-4S] clusters and their delivery to acceptor apo-proteins. Our laboratory has shown that IscU populates two distinct, functionally relevant conformational states, a more structured state (S) and a more dynamic state (D), that differ by cis/trans isomerizations about two peptidyl-prolyl peptide bonds [Kim, J. H., Tonelli, M., and Markley, J. L. (2012) Proc. Natl. Acad. Sci. U.S.A., 109, 454-459. Dai Z., Tonelli, M., and Markley, J. L. (2012) Biochemistry, 51, 9595-9602. Cai, K., Frederick, R. O., Kim, J. H., Reinen, N. M., Tonelli, M., and Markley, J. L. (2013) J. Biol. Chem., 288, 28755-28770]. Here, we report our findings on the pH dependence of the D ⇄ S equilibrium for Escherichia coli IscU in which the D-state is stabilized at low and high pH values. We show that the lower limb of the pH dependence curve results from differences in the pKa values of two conserved histidine residues (His10 and His105) in the two states. The net proton affinity of His10 is about 50 times higher and that of His105 is 13 times higher in the D-state than in the S-state. The origin of the high limb of the D ⇄ S pH dependence remains to be determined. These results show that changes in proton inventory need to be taken into account in the steps in iron-sulfur cluster assembly and transfer that involve transitions of IscU between its S- and D-states.

  7. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    International Nuclear Information System (INIS)

    Rubio-Gonzalez, C.; Gomez-Rosas, G.; Ocana, J.L.; Molpeceres, C.; Banderas, A.; Porro, J.; Morales, M.

    2006-01-01

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm 2 with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy

  8. Green and efficient sample preparation method for the determination of catalyst residues in margarine by ICP-MS.

    Science.gov (United States)

    Hartwig, Carla Andrade; Pereira, Rodrigo Mendes; Novo, Diogo La Rosa; Oliveira, Dirce Taina Teixeira; Mesko, Marcia Foster

    2017-11-01

    Responding to the need for green and efficient methods to determine catalyst residues with suitable precision and accuracy in samples with high fat content, the present work evaluates a microwave-assisted ultraviolet digestion (MW-UV) system for margarines and subsequent determination of Ni, Pd and Pt using inductively coupled plasma mass spectrometry (ICP-MS). It was possible to digest up to 500mg of margarine using only 10mL of 4molL -1 HNO 3 with a digestion efficiency higher than 98%. This allowed the determination of catalyst residues using the ICP-MS and free of interferences. For this purpose, the following experimental parameters were evaluated: concentration of digestion solution, sample mass and microwave irradiation program. The residual carbon content was used as a parameter to evaluate the efficiency of digestion and to select the most suitable experimental conditions. The accuracy evaluation was performed by recovery tests using a standard solution and certified reference material, and recoveries ranging from 94% to 99% were obtained for all analytes. The limits of detection for Ni, Pd and Pt using the proposed method were 35.6, 0.264 and 0.302ngg -1 , respectively. When compared to microwave-assisted digestion (MW-AD) in closed vessels using concentrated HNO 3 (used as a reference method for sample digestion), the proposed MW-UV could be considered an excellent alternative for the digestion of margarine, as this method requires only a diluted nitric acid solution for efficient digestion. In addition, MW-UV provides appropriate solutions for further ICP-MS determination with suitable precision (relative standard deviation < 7%) and accuracy for all evaluated analytes. The proposed method was applied to margarines from different brands produced in Brazil, and the concentration of catalyst residues was in agreement with the current legislation or recommendations. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Quantitative determination and sampling of azathioprine residues for cleaning validation in production area.

    Science.gov (United States)

    Fazio, Tatiana Tatit; Singh, Anil Kumar; Kedor-Hackmann, Erika Rosa Maria; Santoro, Maria Inês Rocha Miritello

    2007-03-12

    Cleaning validation is an integral part of current good manufacturing practices in any pharmaceutical industry. Nowadays, azathioprine and several other pharmacologically potent pharmaceuticals are manufactured in same production area. Carefully designed cleaning validation and its evaluation can ensure that residues of azathioprine will not carry over and cross contaminate the subsequent product. The aim of this study was to validate simple analytical method for verification of residual azathioprine in equipments used in the production area and to confirm efficiency of cleaning procedure. The HPLC method was validated on a LC system using Nova-Pak C18 (3.9 mm x 150 mm, 4 microm) and methanol-water-acetic acid (20:80:1, v/v/v) as mobile phase at a flow rate of 1.0 mL min(-1). UV detection was made at 280 nm. The calibration curve was linear over a concentration range from 2.0 to 22.0 microg mL(-1) with a correlation coefficient of 0.9998. The detection limit (DL) and quantitation limit (QL) were 0.09 and 0.29 microg mL(-1), respectively. The intra-day and inter-day precision expressed as relative standard deviation (R.S.D.) were below 2.0%. The mean recovery of method was 99.19%. The mean extraction-recovery from manufacturing equipments was 83.5%. The developed UV spectrophotometric method could only be used as limit method to qualify or reject cleaning procedure in production area. Nevertheless, the simplicity of spectrophotometric method makes it useful for routine analysis of azathioprine residues on cleaned surface and as an alternative to proposed HPLC method.

  10. Derivation of residual radioactive material guidelines for uranium in soil at the Middlesex Sampling Plant Site, Middlesex, New Jersey

    International Nuclear Information System (INIS)

    Dunning, D.E.

    1995-02-01

    Residual radioactive material guidelines for uranium in soil were derived for the Middlesex Sampling Plant (MSP) site in Middlesex, New Jersey. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy. The site became contaminated from operations conducted in support of the Manhattan Engineer District (MED) and the Atomic Energy Commission (AEC) between 1943 and 1967. Activities conducted at the site included sampling, storage, and shipment of uranium, thorium, and beryllium ores and residues. Uranium guidelines for single radioisotopes and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the MSP site should not exceed a dose of 30 mrem/yr following remedial action for the current-use and likely future-use scenarios or a dose of 100 mrem/yr for less likely future-use scenarios. The RESRAD computer code, which implements the methodology described in the DOE manual for establishing residual radioactive material guidelines, was used in this evaluation. Four scenarios were considered for the site. These scenarios vary regarding future land use at the site, sources of water used, and sources of food consumed

  11. Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

    Directory of Open Access Journals (Sweden)

    Gabriela Islas

    2018-01-01

    Full Text Available Solid-phase extraction in combination with large-volume sample stacking-capillary electrophoresis (SPE-LVSS-CE was applied to measure chlortetracycline, doxycycline, oxytetracycline, and tetracycline in milk samples. Under optimal conditions, the proposed method had a linear range of 29 to 200 µg·L−1, with limits of detection ranging from 18.6 to 23.8 µg·L−1 with inter- and intraday repeatabilities < 10% (as a relative standard deviation in all cases. The enrichment factors obtained were from 50.33 to 70.85 for all the TCs compared with a conventional capillary zone electrophoresis (CZE. This method is adequate to analyze tetracyclines below the most restrictive established maximum residue limits. The proposed method was employed in the analysis of 15 milk samples from different brands. Two of the tested samples were positive for the presence of oxytetracycline with concentrations of 95 and 126 µg·L−1. SPE-LVSS-CE is a robust, easy, and efficient strategy for online preconcentration of tetracycline residues in complex matrices.

  12. Detection of clarithromycin-resistant Helicobacter pylori by polymerase chain reaction using residual samples from rapid urease test

    Directory of Open Access Journals (Sweden)

    Jae-Sik Jeon

    2017-01-01

    Full Text Available Background: Approximately 50% of the world population is infected with Helicobacter pylori, which corresponds to a high infection rate. Furthermore, the incidence of antibiotic-resistant H. pylori has increased with the recent rise in use of antibiotics for H. pylori elimination, suggesting growing treatment failures. Aim: The study was aimed to assess the use of residual samples from rapid urease test (RUT for biomolecular testing as an effective and accurate method to detect antibiotic-resistant H. pylori. Settings and Design: This study was a retrospective study performed using data obtained from medical records of previously isolated H. pylori strains. Materials and Methods: RUT was conducted for 5440 biopsy samples from individuals who underwent health examination in South Korea. Subsequently, 469 RUT residual samples were randomly selected and subjected to polymerase chain reaction (PCR to detect antibiotic-resistant H. pylori. Statistical Analysis Used: The Chi-square test was used to analyse categorical data. P < 0.05 was considered statistically significant. Results: The results showed a concordance between the results of PCR and conventional RUT in 450 of 469 samples, suggesting that the H. pylori PCR test is a time- and cost-effective detection method. Conclusions: This study demonstrated that PCR test can aid physicians to prescribe the appropriate antibiotics at the time of diagnosis, thus preventing the reduction in H. pylori eradication due to antibiotic resistance, averting progression to serious diseases and increasing the treatment success rate.

  13. Enantioselective analysis of chloramphenicol residues in honey samples by chiral LC-MS/MS and results of a honey survey.

    Science.gov (United States)

    Rimkus, Gerhard G; Hoffmann, Dirk

    2017-06-01

    Chloramphenicol (CAP) is a broad-spectrum antibiotic used widely in both human and veterinary medication. Since 1994, CAP has not been authorised for use in food-producing animals in the European Union due to several adverse effects. A minimum required performance level (MRPL) of 0.3 µg kg - 1 was established in 2003. The CAP molecule contains two asymmetric centres, thus in total four para-CAP stereoisomers exist. Only the RR-CAP enantiomer is bioactive, having significant antimicrobial activity. For the first time a chiral LC-MS/MS method is reported to identify and quantify the four CAP enantiomers at residue levels in honey samples. The method was validated at two concentration levels. The decision limits (CCα) and detection capabilities (CCß) were well below 0.3 µg kg - 1 , with limits of quantification (LOQs) between 0.08 and 0.12 µg kg - 1 for all four enantiomers. The method provides a sensitive and reliable analysis of CAP enantiomers in honey, and proved its robustness during the daily routine analyses of numerous honey samples. In an internal honey survey, in total 40 honey samples from different geographical regions with identified CAP residues at or above the MRPL were reanalysed by chiral LC-MS/MS. In nine honey samples only the bioactive RR-CAP was detected as anticipated. However, in all other 31 honey samples the non-bioactive SS-CAP was also identified and quantified unambiguously. In 10 of these samples, mixtures of RR- and SS-CAP were analysed, and in 21 samples only the SS-CAP enantiomer, with concentrations up to 2.2 µg kg - 1 . Most of these samples are honeys from Ukraine and Eastern Europe. This is the first report of SS-CAP residues in food samples. The potential sources for these findings are discussed and the need of further systematic studies emphasised. It is recommended to examine in more depth the toxicological profile of the individual CAP stereoisomers.

  14. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Nissen, Poul

    2008-01-01

    molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...... proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK (a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires....

  15. Laboratory Guide for Residual Stress Sample Alignment and Experiment Planning-October 2011 Version

    Energy Technology Data Exchange (ETDEWEB)

    Cornwell, Paris A [ORNL; Bunn, Jeffrey R [ORNL; Schmidlin, Joshua E [ORNL; Hubbard, Camden R [ORNL

    2012-04-01

    The December 2010 version of the guide, ORNL/TM-2008/159, by Jeff Bunn, Josh Schmidlin, Camden Hubbard, and Paris Cornwell, has been further revised due to a major change in the GeoMagic Studio software for constructing a surface model. The Studio software update also includes a plug-in module to operate the FARO Scan Arm. Other revisions for clarity were also made. The purpose of this revision document is to guide the reader through the process of laser alignment used by NRSF2 at HFIR and VULCAN at SNS. This system was created to increase the spatial accuracy of the measurement points in a sample, reduce the use of neutron time used for alignment, improve experiment planning, and reduce operator error. The need for spatial resolution has been driven by the reduction in gauge volumes to the sub-millimeter level, steep strain gradients in some samples, and requests to mount multiple samples within a few days for relating data from each sample to a common sample coordinate system. The first step in this process involves mounting the sample on an indexer table in a laboratory set up for offline sample mounting and alignment in the same manner it would be mounted at either instrument. In the shared laboratory, a FARO ScanArm is used to measure the coordinates of points on the sample surface ('point cloud'), specific features and fiducial points. A Sample Coordinate System (SCS) needs to be established first. This is an advantage of the technique because the SCS can be defined in such a way to facilitate simple definition of measurement points within the sample. Next, samples are typically mounted to a frame of 80/20 and fiducial points are attached to the sample or frame then measured in the established sample coordinate system. The laser scan probe on the ScanArm can then be used to scan in an 'as-is' model of the sample as well as mounting hardware. GeoMagic Studio 12 is the software package used to construct the model from the point cloud the

  16. Laboratory Guide for Residual Stress Sample Alignment and Experiment Planning-October 2011 Version

    International Nuclear Information System (INIS)

    Cornwell, Paris A.; Bunn, Jeffrey R.; Schmidlin, Joshua E.; Hubbard, Camden R.

    2012-01-01

    The December 2010 version of the guide, ORNL/TM-2008/159, by Jeff Bunn, Josh Schmidlin, Camden Hubbard, and Paris Cornwell, has been further revised due to a major change in the GeoMagic Studio software for constructing a surface model. The Studio software update also includes a plug-in module to operate the FARO Scan Arm. Other revisions for clarity were also made. The purpose of this revision document is to guide the reader through the process of laser alignment used by NRSF2 at HFIR and VULCAN at SNS. This system was created to increase the spatial accuracy of the measurement points in a sample, reduce the use of neutron time used for alignment, improve experiment planning, and reduce operator error. The need for spatial resolution has been driven by the reduction in gauge volumes to the sub-millimeter level, steep strain gradients in some samples, and requests to mount multiple samples within a few days for relating data from each sample to a common sample coordinate system. The first step in this process involves mounting the sample on an indexer table in a laboratory set up for offline sample mounting and alignment in the same manner it would be mounted at either instrument. In the shared laboratory, a FARO ScanArm is used to measure the coordinates of points on the sample surface ('point cloud'), specific features and fiducial points. A Sample Coordinate System (SCS) needs to be established first. This is an advantage of the technique because the SCS can be defined in such a way to facilitate simple definition of measurement points within the sample. Next, samples are typically mounted to a frame of 80/20 and fiducial points are attached to the sample or frame then measured in the established sample coordinate system. The laser scan probe on the ScanArm can then be used to scan in an 'as-is' model of the sample as well as mounting hardware. GeoMagic Studio 12 is the software package used to construct the model from the point cloud the scan arm creates. Once

  17. Sampling and Analysis Plan for Verification Sampling of LANL-Derived Residual Radionuclides in Soils within Tract A-18-2 for Land Conveyance

    Energy Technology Data Exchange (ETDEWEB)

    Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-30

    Public Law 105-119 directs the U.S. Department of Energy (DOE) to convey or transfer parcels of land to the Incorporated County of Los Alamos or their designees and to the Department of Interior, Bureau of Indian Affairs, in trust for the Pueblo de San Ildefonso. Los Alamos National Security is tasked to support DOE in conveyance and/or transfer of identified land parcels no later than September 2022. Under DOE Order 458.1, Radiation Protection of the Public and the Environment (O458.1, 2013) and Los Alamos National Laboratory (LANL or the Laboratory) implementing Policy 412 (P412, 2014), real property with the potential to contain residual radioactive material must meet the criteria for clearance and release to the public. This Sampling and Analysis Plan (SAP) is a second investigation of Tract A-18-2 for the purpose of verifying the previous sampling results (LANL 2017). This sample plan requires 18 projectspecific soil samples for use in radiological clearance decisions consistent with LANL Procedure ENV-ES-TP-238 (2015a) and guidance in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM, 2000). The sampling work will be conducted by LANL, and samples will be evaluated by a LANL-contracted independent lab. However, there will be federal review (verification) of all steps of the sampling process.

  18. Evaluation of Total Nitrite Pattern Visualization as an Improved Method for Gunshot Residue Detection and its Application to Casework Samples.

    Science.gov (United States)

    Berger, Jason; Upton, Colin; Springer, Elyah

    2018-04-23

    Visualization of nitrite residues is essential in gunshot distance determination. Current protocols for the detection of nitrites include, among other tests, the Modified Griess Test (MGT). This method is limited as nitrite residues are unstable in the environment and limited to partially burned gunpowder. Previous research demonstrated the ability of alkaline hydrolysis to convert nitrates to nitrites, allowing visualization of unburned gunpowder particles using the MGT. This is referred to as Total Nitrite Pattern Visualization (TNV). TNV techniques were modified and a study conducted to streamline the procedure outlined in the literature to maximize the efficacy of the TNV in casework, while reducing the required time from 1 h to 5 min, and enhancing effectiveness on blood-soiled samples. The TNV method was found to provide significant improvement in the ability to detect significant nitrite residues, without sacrificing efficiency, that would allow for the determination of the muzzle-to-target distance. © 2018 American Academy of Forensic Sciences.

  19. Estimating the spatial scale of herbicide and soil interactions by nested sampling, hierarchical analysis of variance and residual maximum likelihood

    Energy Technology Data Exchange (ETDEWEB)

    Price, Oliver R., E-mail: oliver.price@unilever.co [Warwick-HRI, University of Warwick, Wellesbourne, Warwick, CV32 6EF (United Kingdom); University of Reading, Soil Science Department, Whiteknights, Reading, RG6 6UR (United Kingdom); Oliver, Margaret A. [University of Reading, Soil Science Department, Whiteknights, Reading, RG6 6UR (United Kingdom); Walker, Allan [Warwick-HRI, University of Warwick, Wellesbourne, Warwick, CV32 6EF (United Kingdom); Wood, Martin [University of Reading, Soil Science Department, Whiteknights, Reading, RG6 6UR (United Kingdom)

    2009-05-15

    An unbalanced nested sampling design was used to investigate the spatial scale of soil and herbicide interactions at the field scale. A hierarchical analysis of variance based on residual maximum likelihood (REML) was used to analyse the data and provide a first estimate of the variogram. Soil samples were taken at 108 locations at a range of separating distances in a 9 ha field to explore small and medium scale spatial variation. Soil organic matter content, pH, particle size distribution, microbial biomass and the degradation and sorption of the herbicide, isoproturon, were determined for each soil sample. A large proportion of the spatial variation in isoproturon degradation and sorption occurred at sampling intervals less than 60 m, however, the sampling design did not resolve the variation present at scales greater than this. A sampling interval of 20-25 m should ensure that the main spatial structures are identified for isoproturon degradation rate and sorption without too great a loss of information in this field. - Estimating the spatial scale of herbicide and soil interactions by nested sampling.

  20. Estimating the spatial scale of herbicide and soil interactions by nested sampling, hierarchical analysis of variance and residual maximum likelihood

    International Nuclear Information System (INIS)

    Price, Oliver R.; Oliver, Margaret A.; Walker, Allan; Wood, Martin

    2009-01-01

    An unbalanced nested sampling design was used to investigate the spatial scale of soil and herbicide interactions at the field scale. A hierarchical analysis of variance based on residual maximum likelihood (REML) was used to analyse the data and provide a first estimate of the variogram. Soil samples were taken at 108 locations at a range of separating distances in a 9 ha field to explore small and medium scale spatial variation. Soil organic matter content, pH, particle size distribution, microbial biomass and the degradation and sorption of the herbicide, isoproturon, were determined for each soil sample. A large proportion of the spatial variation in isoproturon degradation and sorption occurred at sampling intervals less than 60 m, however, the sampling design did not resolve the variation present at scales greater than this. A sampling interval of 20-25 m should ensure that the main spatial structures are identified for isoproturon degradation rate and sorption without too great a loss of information in this field. - Estimating the spatial scale of herbicide and soil interactions by nested sampling.

  1. Filter paper saturated by urine sample in metabolic disorders detection by proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Blasco, Hélène; Garrigue, Marie-Ange; De Vos, Aymeric; Antar, Catherine; Labarthe, François; Maillot, François; Andres, Christian R; Nadal-Desbarats, Lydie

    2010-02-01

    NMR spectroscopy of urine samples is able to diagnose many inborn errors of metabolism (IEM). However, urinary metabolites have a poor stability, requiring special care for routine analysis (storage of urine at -20 or -80 degrees C, fast transport). The aim of our study was to investigate the reliability of dried urine filter paper for urine storage and transport and to evaluate the ability of NMR to detect several IEM using this method. Urine samples from five healthy subjects were analyzed by (1)H NMR following different storage conditions (-20 vs 4 degrees C vs dried on filter paper) and at different time points (24 h, 48 h, 96 h, and 7 days). Urine pattern of fresh urine was considered as a reference. We analyzed the conservation of some amino acids and organic acids using Bland and Altman plot with intraclass correlation coefficient determination. Then, we evaluated the use of filter paper to detect four different IEM (methylmalonic and isovaleric acidurias, ornithine transcarbamylase deficiency, and cystinuria). Analysis of urine samples from healthy subjects revealed a high stability of studied molecules (ICC > 0.8) even after 7 days of storage on filter paper. Moreover, an excellent preservation of metabolites specifically accumulated in IEM was observed when analysis of dried urine filter paper was compared to fresh urine (coefficient of variation storage of dried urine on filter paper is reliable for (1)H NMR spectroscopy analysis. Preservation of urine molecules over time using that method is convenient for routine clinical practice.

  2. Guidance Document: Surface Soils Sampling for Munitions Residues in Military Live Fire Training Ranges: Canadian Protocol

    Science.gov (United States)

    2012-12-01

    nitrocellulose fibres. For samples larger than 500 g, multiple batches are used and the final fine powder (which looks like flour ) is mixed thoroughly on a...Clausen, J., Hewitt, A.D., Brochu, S., Dubé, P., Lewis, J., Ranney, T., Faucher, D., Gagnon, A., Stark, J., Brousseau, P., Price , C., Lambert, D

  3. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    Energy Technology Data Exchange (ETDEWEB)

    D' Andrea, Chris B. [Univ. of Pennsylvania, Philadelphia, PA (United States); et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  4. Proton Induced X-ray Emission Spectroscopy of Red Wine Samples Using the Union College Pelletron Accelerator

    Science.gov (United States)

    Schuff, Katie; Labrake, Scott

    2010-11-01

    A 1-megavolt tandem electrostatic Pelletron particle accelerator housed at Union College was used to measure the elemental composition and concentration of homemade Cabernet and Merlot red wine samples. A beam of 1.8-MeV protons directed at an approximately 12-μm thin Mylar substrate onto which 8-μL of concentrated red wine was dried caused inner shell electrons to be ejected from the target nuclei and these vacancies are filled through electronic transitions of higher orbital electrons accompanied by the production of an x-ray photon characteristic of the elemental composition of the target. This is the PIXE Method. Data on the intensity versus energy of the x-rays were collected using an Amptek silicon drift detector and were analyzed to determine the elemental composition and the samples were found to contain P, S, K, Cl, Ca, Sc, Mn, Al, Fe, & Co. Elemental concentrations were determined using the analysis package GUPIX. It is hypothesized that the cobalt seen is a direct result of the uptake by the grapes and as a product of the fermentation process a complex of vitamin B12 is produced.

  5. Sample-based reporting of official national control of veterinary drug residues

    DEFF Research Database (Denmark)

    Andersen, Jens Hinge; Jensen, Louise Grønhøj Hørbye; Madsen, Helle L.

    assessment as well as risk management. The European Food Safety Authority has been assigned with the task to set up a system for data collection based on individual analytical results. A pilot project has been launched with participants from eleven Member States for parallel reporting of monitoring results...... from 2015 in aggregated form as well as individual analytical results using a standardised data model. The challenges that face the pilot participants include provisions for categorised sample information, specific method performance data, result evaluation and follow-up actions. Experience gained...

  6. Pesticide residues in fruit samples: comparison of different QuEChERS methods using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Christia, C; Bizani, E; Christophoridis, C; Fytianos, K

    2015-09-01

    Acetate- and citrate-buffered quick, easy, cheap, effective, rugged, safe (QuEChERS) pretreatment methods were evaluated for the determination of various pesticides in peaches, grapes, apples, bananas, pears, and strawberries from various regions of Greece, using LC-MS/MS. The purposes of this study were (i) to evaluate which type of QuEChERS method was the most appropriate and effective for each matrix; (ii) to apply the selected QuEChERS method for each matrix, in order to detect and quantify pesticide residues in various fruit samples using UPLC-MS/MS; (iii) to examine the concentration distribution of pesticide classes among fruit originating from various areas; and (iv) to assess pesticide concentration distribution between peel and flesh of fruit in order to evaluate the penetration of pesticide residues in the fruit flesh. Acetate-buffered QuEChERS was found to be the most suitable technique for most of the fruit matrices. According to the recovery values at two different concentration levels, peaches should preferably be treated by the citrate-buffered type, whereas grapes, bananas, apples, pears, and strawberries are best treated by the acetate-buffered version, although the differences in efficiency were small. The addition of graphitized carbon black significantly decreases the recovery of specific pesticides in all matrices except for strawberries. The majority of values do not exceed the official maximum residue levels set by the European Commission. Organophosphates proved to be the most commonly detected category along with triazines-triazoles-conazoles group and by carbamates. Apples and pears seem to be the most contaminated fruit matrices among those tested. Distribution of pesticide classes shows variations between different regions, suggesting different pesticide application practices. In the case of peaches and pears, there is an equal distribution of detected pesticides between peel and flesh, indicating penetration of contaminants into the

  7. Combination of QuEChERS and DLLME for GC-MS determination of pesticide residues in orange samples.

    Science.gov (United States)

    Andraščíková, Mária; Hrouzková, Svetlana; Cunha, Sara C

    2013-01-01

    A new method combining QuEChERS (quick, easy, cheap, effective, rugged and safe) and DLLME (dispersive liquid-liquid microextraction) followed by gas chromatography-mass spectrometry with selected ion monitoring (SIM) was developed for the simultaneous determination of 19 pesticides from nine chemical groups exhibiting or suspected to exhibit endocrine-disrupting properties in orange samples. Acetonitrile extract obtained from QuEChERS extraction was used for DLLME as dispersive solvent and carbon tetrachloride as extractive solvent to increase the enrichment factor of the extraction procedure. The effect of several extraction parameters, such as volume extract achieved by the QuEChERS method and subsequently used for DLLME, selection of extractive solvent and its volume, was tested. Under optimum conditions, good linearity, satisfactory recoveries and repeatability were obtained. Limits of quantification (LOQs) achieved (ranging from 0.02 to 47 ng/g) were below the maximum residue limits established by the European Union. The proposed method was applied to the monitoring of pesticide residue levels in oranges commercialised in Portugal.

  8. Determination of organophosphorus pesticides and their major degradation product residues in food samples by HPLC-UV.

    Science.gov (United States)

    Peng, Guilong; He, Qiang; Lu, Ying; Mmereki, Daniel; Zhong, Zhihui

    2016-10-01

    A simple method based on dispersive solid-phase extraction (DSPE) and dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) was developed for the extraction of chlorpyrifos (CP), chlorpyrifos-methyl (CPM), and their main degradation product 3,5,6-trichloro-2-pyridinol (TCP) in tomato and cucumber samples. The determination was carried out by high performance liquid chromatography with ultraviolet detection (HPLC-UV). In the DSPE-DLLME-SFO, the analytes were first extracted with acetone. The clean-up of the extract by DSPE was carried out by directly adding activated carbon sorbent into the extract solution, followed by shaking and filtration. Under the optimum conditions, the proposed method was sensitive and showed a good linearity within a range of 2-500 ng/g, with the correlation coefficients (r) varying from 0.9991 to 0.9996. The enrichment factors ranged from 127 to 138. The limit of detections (LODs) were in the range of 0.12-0.68 ng/g, and the relative standard deviations (RSDs) for 50 ng/g of each analytes in tomato samples were in the range of 3.25-6.26 % (n = 5). The proposed method was successfully applied for the extraction and determination of the mentioned analytes residues in tomato and cucumber samples, and satisfactory results were obtained.

  9. Single-particle characterization of ice-nucleating particles and ice particles residuals sampled by three different techniques

    Science.gov (United States)

    Kandler, Konrad; Worringen, Annette; Benker, Nathalie; Dirsch, Thomas; Mertes, Stephan; Schenk, Ludwig; Kästner, Udo; Frank, Fabian; Nillius, Björn; Bundke, Ulrich; Rose, Diana; Curtius, Joachim; Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Schneider, Johannes; Schmidt, Susan; Weinbruch, Stephan; Ebert, Martin

    2015-04-01

    During January/February 2013, at the High Alpine Research Station Jungfraujoch a measurement campaign was carried out, which was centered on atmospheric ice-nucleating particles (INP) and ice particle residuals (IPR). Three different techniques for separation of INP and IPR from the non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed phase clouds and allow for the analysis of the residuals. The combination of the Fast Ice Nucleus Chamber (FINCH) and the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated INP for analysis. Collected particles were analyzed by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine size, chemical composition and mixing state. All INP/IPR-separating techniques had considerable abundances (median 20 - 70 %) of instrumental contamination artifacts (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH+IN-PCVI: steel particles). Also, potential sampling artifacts (e.g., pure soluble material) occurred with a median abundance of separated by all three techniques. Soot was a minor contributor. Lead was detected in less than 10 % of the particles, of which the majority were internal mixtures with other particle types. Sea-salt and sulfates were identified by all three methods as INP/IPR. Most samples showed a maximum of the INP/IPR size distribution at 400 nm geometric diameter. In a few cases, a second super-micron maximum was identified. Soot/carbonaceous material and metal oxides were present mainly in the submicron range. ISI and FINCH yielded silicates and Ca-rich particles mainly with diameters above 1 µm, while the Ice-CVI also separated many submicron IPR. As strictly parallel sampling could not be performed, a part of the discrepancies between the different techniques may result from

  10. Multi-rate cubature Kalman filter based data fusion method with residual compensation to adapt to sampling rate discrepancy in attitude measurement system.

    Science.gov (United States)

    Guo, Xiaoting; Sun, Changku; Wang, Peng

    2017-08-01

    This paper investigates the multi-rate inertial and vision data fusion problem in nonlinear attitude measurement systems, where the sampling rate of the inertial sensor is much faster than that of the vision sensor. To fully exploit the high frequency inertial data and obtain favorable fusion results, a multi-rate CKF (Cubature Kalman Filter) algorithm with estimated residual compensation is proposed in order to adapt to the problem of sampling rate discrepancy. During inter-sampling of slow observation data, observation noise can be regarded as infinite. The Kalman gain is unknown and approaches zero. The residual is also unknown. Therefore, the filter estimated state cannot be compensated. To obtain compensation at these moments, state error and residual formulas are modified when compared with the observation data available moments. Self-propagation equation of the state error is established to propagate the quantity from the moments with observation to the moments without observation. Besides, a multiplicative adjustment factor is introduced as Kalman gain, which acts on the residual. Then the filter estimated state can be compensated even when there are no visual observation data. The proposed method is tested and verified in a practical setup. Compared with multi-rate CKF without residual compensation and single-rate CKF, a significant improvement is obtained on attitude measurement by using the proposed multi-rate CKF with inter-sampling residual compensation. The experiment results with superior precision and reliability show the effectiveness of the proposed method.

  11. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  12. Detection of Residual Levels and Associated Health Risk of Seven Pesticides in Fresh Eggplant and Tomato Samples from Narayanganj District, Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Nur Alam

    2015-01-01

    Full Text Available Residual levels of seven frequently used pesticides were investigated in 140 samples of two common vegetables, eggplants and tomatoes, from agricultural fields in the Narayanganj district of Bangladesh. The analysis of pesticide residues was performed by high-performance liquid chromatography with photodiode array detection. A large percentage of the eggplants (50% and tomatoes (60% from the Narayanganj district were contaminated with pesticides, and all of the levels were above the maximum residual limit (MRL proposed by the EC regulation. Diazinon was the most common (35% pesticide detected in the vegetable samples at a concentration of 45–450 times higher than the MRL. The health risk index for diazinon was highest for both eggplant and tomato samples, which may be due to its physiochemical properties. Fenitrothion and linuron are the two second most common types of pesticides detected in the vegetable samples. Regular monitoring of the use of common pesticides on vegetables should be conducted.

  13. Pre-concentration of pesticide residues in environmental water samples using Silica nanoparticles and identification of residues By GC-MS method

    OpenAIRE

    Tentu. Nageswara Rao; A. Muralidhar Reddy; SNVS. Murthy; Prathipati Revathi; K. Suneel Kumar

    2016-01-01

    The silica nanoparticles prepared by stober’s mechanism by reaction of tetraethylorthosilicate (TEOS) with ammonia was tested for their adsorption capacity in the pre-concentration of residues of pesticides in water. The synthesized nanoparticles were characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The size of the silica nanoparticles were 50 to 250 nm. The solid phase extraction (SPE) cartridges were prepared by filling...

  14. Residues of lindane and endosulfan in water and fish samples from rivers, farms in Besease, Agogo and Akomadan in the Ashanti region of Ghana

    International Nuclear Information System (INIS)

    Osafo-Acquaah, S.; Frimpong, E.

    1997-01-01

    Pesticide residue analyses were performed on water and fish samples from River Oda in Besease, River Aframso in Nobewam near Kumasi, River Atwetwe in Akomadan, and River Kowire at Agogo. Residues of lindane and endosulfan were found in water and fish (Oreochromis niloticus, Tilapia zillii, Barbus trispulis, Heterobranchus sp., Tilapia busumana, Ophiocephalus obscura and Chana obscura) samples. The residues of lindane varied between the years and months in the year but were in the range of 0.3 - 15 ng L -1 (1993-94) and 8.7-32.0 ng L -1 (1995) for the water samples and 0.2-24 ng g -1 (1993-93) and 8.4-120.4 ng g -1 (1995) for the fish samples. Residues of endosulfan in the water and the fish samples were zero in 1993-1994 but, in 1995, were in the range of 6.4-35.2 ng L -1 for the water samples and 5.0-267.5 ng g -1 for the fish samples. In all cases the lindane and ensofulfan concentrations in the water were 10,000-20,000 times lower than known toxic concentration levels and therefore unlikely to cause fish toxicity problems. (author). 11 refs, 4 tabs

  15. Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques

    Science.gov (United States)

    Worringen, A.; Kandler, K.; Benker, N.; Dirsch, T.; Mertes, S.; Schenk, L.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Curtius, J.; Kupiszewski, P.; Weingartner, E.; Vochezer, P.; Schneider, J.; Schmidt, S.; Weinbruch, S.; Ebert, M.

    2015-04-01

    In the present work, three different techniques to separate ice-nucleating particles (INPs) as well as ice particle residuals (IPRs) from non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed-phase clouds and allow after evaporation in the instrument for the analysis of the residuals. The Fast Ice Nucleus Chamber (FINCH) coupled with the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated particles for analysis. The instruments were run during a joint field campaign which took place in January and February 2013 at the High Alpine Research Station Jungfraujoch (Switzerland). INPs and IPRs were analyzed offline by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Online analysis of the size and chemical composition of INP activated in FINCH was performed by laser ablation mass spectrometry. With all three INP/IPR separation techniques high abundances (median 20-70%) of instrumental contamination artifacts were observed (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). After removal of the instrumental contamination particles, silicates, Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types obtained by all three techniques. In addition, considerable amounts (median abundance mostly a few percent) of soluble material (e.g., sea salt, sulfates) were observed. As these soluble particles are often not expected to act as INP/IPR, we consider them as potential measurement artifacts. Minor types of INP/IPR include soot and Pb-bearing particles. The Pb-bearing particles are mainly present as an internal mixture with other particle types. Most samples showed a maximum of the INP/IPR size distribution at 200

  16. Optimization of a method by liquid chromatography of high resolution to determine residues of ethilenthiourea in samples of tomato

    International Nuclear Information System (INIS)

    Mora, D.; Rodriguez, O.M.

    2002-01-01

    A method was optimized to determine the present residues of ethilenthiourea in samples of tomatoes. The method consisted of three stages: a extraction of ultrasonic bath with methanol; a cleaning of the extract through a glass column of 11 mm of diameter stuffed with 2,5 g of neutral aluminium's mixture and activated coal (97,5:2,5) and 2,5 g of pure-neutral aluminium, it is dissolved with 250 ml of methanol. The third stage was of quantification by HPLC in a C 18 ' column with a methanol and water mixture (90:10) like a mobile phase to an flow of 2,0 ml/min. and with UV detection to 232 nm. The retention's time under theses conditions was of 2,15 minutes. The merit's parameters of the method were determined, proving and lineal sphere between 1,0 and 28,0 (g/ml of ETU; some quantification and detection limits have been calculated by the method of Hubaux and Vos (22) of 0,153 and 0,306 mg/ml respectively and a recuperation of 84%. (Author) [es

  17. The determination of trace quantities of thorium and uranium in thick ore samples by proton-induced x-ray emission

    International Nuclear Information System (INIS)

    Cohen, D.D.; Duerden, P.; Clayton, E.

    1979-07-01

    Proton-induced X-ray emission (PIXE) techniques have been used to estimate the concentrations of trace quantities of thorium and uranium in powdered rock and ore samples. Standards of known concentrations were prepared in a carbon matrix and the yields from these used to determine simultaneously the concentrations of thorium and uranium in the ore samples. The experimental detection limit of the technique was found to be 3 to 4 μg g -1 for a 100 μC irradiation. The appropriate matrix corrections for a carbon and ore matrix have been calculated for thick targets and taken into consideration

  18. Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex III: Neutron Devices and Computational and Sample Environments

    Directory of Open Access Journals (Sweden)

    Kaoru Sakasai

    2017-08-01

    Full Text Available Neutron devices such as neutron detectors, optical devices including supermirror devices and 3He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF of the Japan Proton Accelerator Research Complex (J-PARC, Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

  19. Investigation of the formation of residual nuclei from the radiactive .sup.237 Np and .sup.241 Am targets in the reaction with 660-MeV protons

    Czech Academy of Sciences Publication Activity Database

    Adam, Jindřich; Balabekyan, A. R.; Brandt, R.; Dzhelepov, V. P.; Gustov, S. A.; Kalinnikov, V. G.; Krivopustov, M. I.; Mirokhin, I. V.; Mrázek, Jaromír; Odoj, R.

    2002-01-01

    Roč. 65, č. 5 (2002), s. 797-809 ISSN 0044-0027 R&D Projects: GA AV ČR KSK1048102 Keywords : protons * spallation * target activation * radionuclides Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  20. Apparatus for proton radiography

    International Nuclear Information System (INIS)

    Martin, R.L.

    1976-01-01

    An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors. 10 claims, 7 drawing figures

  1. Estimates of diet selection in cattle grazing cornstalk residues by measurement of chemical composition and near infrared reflectance spectroscopy of diet samples collected by ruminal evacuation.

    Science.gov (United States)

    Petzel, Emily A; Smart, Alexander J; St-Pierre, Benoit; Selman, Susan L; Bailey, Eric A; Beck, Erin E; Walker, Julie A; Wright, Cody L; Held, Jeffrey E; Brake, Derek W

    2018-05-04

    Six ruminally cannulated cows (570 ± 73 kg) fed corn residues were placed in a 6 × 6 Latin square to evaluate predictions of diet composition from ruminally collected diet samples. After complete ruminal evacuation, cows were fed 1-kg meals (dry matter [DM]-basis) containing different combinations of cornstalk and leaf and husk (LH) residues in ratios of 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. Diet samples from each meal were collected by removal of ruminal contents after 1-h and were either unrinsed, hand-rinsed or machine-rinsed to evaluate effects of endogenous compounds on predictions of diet composition. Diet samples were analyzed for neutral (NDF) and acid (ADF) detergent fiber, acid detergent insoluble ash (ADIA), acid detergent lignin (ADL), crude protein (CP), and near infrared reflectance spectroscopy (NIRS) to calculate diet composition. Rinsing type increased NDF and ADF content and decreased ADIA and CP content of diet samples (P content of diet samples. Differences in concentration between cornstalk and LH residues within each chemical component were standardized by calculating a coefficient of variation (CV). Accuracy and precision of estimates of diet composition were analyzed by regressing predicted diet composition and known diet composition. Predictions of diet composition were improved by increasing differences in concentration of chemical components between cornstalk and LH residues up to a CV of 22.6 ± 5.4%. Predictions of diet composition from unrinsed ADIA and machine-rinsed NIRS had the greatest accuracy (slope = 0.98 and 0.95, respectively) and large coefficients of determination (r2 = 0.86 and 0.74, respectively). Subsequently, a field study (Exp. 2) was performed to evaluate predictions of diet composition in cattle (646 ± 89 kg) grazing corn residue. Five cows were placed in 1 of 10 paddocks and allowed to graze continuously or to strip-graze corn residues. Predictions of diet composition from ADIA, ADL, and NIRS did not

  2. Different Analytical Procedures for the Study of Organic Residues in Archeological Ceramic Samples with the Use of Gas Chromatography-mass Spectrometry.

    Science.gov (United States)

    Kałużna-Czaplińska, Joanna; Rosiak, Angelina; Kwapińska, Marzena; Kwapiński, Witold

    2016-01-01

    The analysis of the composition of organic residues present in pottery is an important source of information for historians and archeologists. Chemical characterization of the materials provides information on diets, habits, technologies, and original use of the vessels. This review presents the problem of analytical studies of archeological materials with a special emphasis on organic residues. Current methods used in the determination of different organic compounds in archeological ceramics are presented. Particular attention is paid to the procedures of analysis of archeological ceramic samples used before gas chromatography-mass spectrometry. Advantages and disadvantages of different extraction methods and application of proper quality assurance/quality control procedures are discussed.

  3. Organophosphorus and Carbamate Pesticide Residues Detected in Water Samples Collected from Paddy and Vegetable Fields of the Savar and Dhamrai Upazilas in Bangladesh

    Directory of Open Access Journals (Sweden)

    Nurul Karim

    2012-09-01

    Full Text Available Several types of organophosphorous and carbamate pesticides have been used extensively by the farmers in Bangladesh during the last few decades. Twenty seven water samples collected from both paddy and vegetable fields in the Savar and Dhamrai Upazilas in Bangladesh were analyzed to determine the occurrence and distribution of organo-phosphorus (chlorpyrifos, malathion and diazinon and carbamate (carbaryl and carbofuran pesticide residues. A high performance liquid chromatograph instrument equipped with a photodiode array detector was used to determine the concentrations of these pesticide residues. Diazinon and carbofuran were detected in water samples collected from Savar Upazila at 0.9 μg/L and 198.7 μg/L, respectively. Malathion was also detected in a single water sample at 105.2 μg/L from Dhamrai Upazila. Carbaryl was the most common pesticide detected in Dhamrai Upazila at 14.1 and 18.1 μg/L, while another water sample from Dhamrai Upazila was contaminated with carbofuran at 105.2 μg/L. Chlorpyrifos was not detected in any sample. Overall, the pesticide residues detected were well above the maximum acceptable levels of total and individual pesticide contamination, at 0.5 and 0.1 μg/L, respectively, in water samples recommended by the European Economic Community (Directive 98/83/EC. The presence of these pesticide residues may be attributed by their intense use by the farmers living in these areas. Proper handling of these pesticides should be ensured to avoid direct or indirect exposure to these pesticides.

  4. Role of Sample Processing Strategies at the European Union National Reference Laboratories (NRLs) Concerning the Analysis of Pesticide Residues

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Herrmann, Susan Strange; Poulsen, Mette Erecius

    2017-01-01

    to the European Union Reference Laboratory on Cereals and Feedingstuff (EURL) for the determination of the particle size distribution and pesticide residue recovery. The results showed that the NRLs used several different brands and types of mills. Large variations in the particle size distributions and pesticide...

  5. The relationship between blood and muscle samples to monitor for residues of the antibiotic enrofloxacin in chickens

    Science.gov (United States)

    Use of antibiotics in food animals has generated concern as the presence of these residues in food may contribute to increased microbial resistance in humans. Fluoroquinolone antibiotics are thus now no longer allowed by the U.S. Food and Drug Administration for use in poultry and monitoring of the...

  6. Solid phase microextraction sampling of high explosive residues in the presence of radionuclides and radionuclide surrogate metals

    International Nuclear Information System (INIS)

    Duff, M.C.; Crump, S.L.; Ray, R.J.; Beals, D.; Cotham, W.E.; Mount, K.; Koons, R.D.; Leggitt, J.

    2008-01-01

    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) evidence while maintaining evidentiary value. One experimental method for the isolation of HE residue involves using solid phase microextraction (SPME) fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ( 239/240 Pu, 238 U, 237 Np, 85 Sr, 133 Ba, 137 Cs, 60 Co and 226 Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection. (author)

  7. A review of novel strategies of sample preparation for the determination of antibacterial residues in foodstuffs using liquid chromatography-based analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Marazuela, M.D., E-mail: marazuela@quim.ucm.es [Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Bogialli, S [Department of Chemistry, University of Rome ' La Sapienza' , Piazza Aldo Moro, 5 00185 Rome (Italy)

    2009-07-10

    The determination of trace residues and contaminants in food has been of growing concern over the past few years. Residual antibacterials in food constitute a risk to human health, especially because they can contribute to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. Therefore, to ensure food safety EU and USA regulatory agencies have established lists of forbidden or banned substances and tolerance levels for authorized veterinary drugs (e.g. antibacterials). In addition, the EU Commission Decision 2002/657/EC has set requirements about the performance of analytical methods for the determination of veterinary drug residues in food and feedstuffs. During the past years, the use of powerful mass spectrometric detectors in combination with innovative chromatographic technologies has solved many problems related to sensitivity and selectivity of this type of analysis. However sample preparation still remains as the bottleneck step, mainly in terms of analysis time and sources of error. This review covering research published between 2004 and 2008 intends to provide an update overview of the past five years, on recent trends in sample preparation for the determination of antibacterial residues in foods, making special emphasis in on-line, high-throughput, multi-class methods and including several applications in detail.

  8. Prospects for future proton studies at HRIBF

    International Nuclear Information System (INIS)

    Bingham, C.R.; Batchelder, J. C.; Ginter, T.N.; Gross, C.J.; Grzywacz, R.; Janas, Z.; Karny, M.; McConnell, J.W.; Toth, K.S.; Rykaczewski, K.; Zganjar, E. F.

    2000-01-01

    Great progress has been made in the last 20 years in the study of proton emission from unstable nuclei, but the prospects for additional strides in the next several years are bright. The present main limitations on the study of proton radioactivity are related to the inability to produce copious quantities of nuclides beyond the proton drip line, and the difficulty of measuring proton radioactivity of a mass-separated nucleus in the first few microseconds of its existence. At the Holifield Facility we will attack the second of these limitations by using new signal processing CAMAC modules DGF-4C. Digitizing of the preamplifier signals should enable the analysis of a proton decay occurring at times even less than 1 microsecond after an implant in a strip detector. In the same process, the threshold energy at which we can make measurements will be lowered. These two things will hopefully enable the measurement of lower-energy, but faster decays of isotopes in the 100 Sn region and below. For the latter region, the proton decays crucial for a rp-process scenario are of particular interest (e.g. 69 Br decay). Secondly, for very short-lived species, we plan to make measurements (without residue separation) at points much closer to the target, thus reducing the flight time between the target and detector. As more intense radioactive beams become available, eg. 56 Ni, we will utilize these to produce more neutron-deficient nuclides by use of colder reactions than is possible with stable beams. In some cases where delayed proton emitters are present in the same isobaric chain, the use of the cold reactions with radioactive beams can provide purer samples of the isotope of interest, with a reduction in background from the delayed proton emitters in the same mass chain

  9. The proton induced X-ray emission (PIXE) for the quantitative analysis of elements in thin samples, in surface layers of thick samples, and in aerosol filters

    International Nuclear Information System (INIS)

    Waetjen, U.

    1983-01-01

    The PIXE analysis method for the determination of elements in thick samples was investigated. The text of the present thesis is arranged under the following headings: physical fundamentals and measuring equipment, quantitative analysis of thin samples, matrix effects at the PIXE analysis of thick samples, matrix correction methods, analysis of 'infinite thick' model substances, PIXE analysis of aerosol filters. (GSCH)

  10. Optimization of Proton CT Detector System and Image Reconstruction Algorithm for On-Line Proton Therapy.

    Directory of Open Access Journals (Sweden)

    Chae Young Lee

    Full Text Available The purposes of this study were to optimize a proton computed tomography system (pCT for proton range verification and to confirm the pCT image reconstruction algorithm based on projection images generated with optimized parameters. For this purpose, we developed a new pCT scanner using the Geometry and Tracking (GEANT 4.9.6 simulation toolkit. GEANT4 simulations were performed to optimize the geometric parameters representing the detector thickness and the distance between the detectors for pCT. The system consisted of four silicon strip detectors for particle tracking and a calorimeter to measure the residual energies of the individual protons. The optimized pCT system design was then adjusted to ensure that the solution to a CS-based convex optimization problem would converge to yield the desired pCT images after a reasonable number of iterative corrections. In particular, we used a total variation-based formulation that has been useful in exploiting prior knowledge about the minimal variations of proton attenuation characteristics in the human body. Examinations performed using our CS algorithm showed that high-quality pCT images could be reconstructed using sets of 72 projections within 20 iterations and without any streaks or noise, which can be caused by under-sampling and proton starvation. Moreover, the images yielded by this CS algorithm were found to be of higher quality than those obtained using other reconstruction algorithms. The optimized pCT scanner system demonstrated the potential to perform high-quality pCT during on-line image-guided proton therapy, without increasing the imaging dose, by applying our CS based proton CT reconstruction algorithm. Further, we make our optimized detector system and CS-based proton CT reconstruction algorithm potentially useful in on-line proton therapy.

  11. Proton NMR Studies of a Large Protein. pH, Substrate Titrations, and NOESY Experiments with Perdeuterated Yeast Phosphoglycerate Kinase Containing [ 1H]Histidine Residues

    Science.gov (United States)

    Pappu, K. M.; Serpersu, E. H.

    Fully deuterated yeast phosphoglycerate kinase ([ 2H]PGK) was prepared biosynthetically with only histidine side chains of normal ( 1H) isotopic composition. The 1H NMR spectrum of this enzyme([ 1H]His[ 2H]PGK) showed that the histidine side chains are clearly visible as sharp signals. Thus detailed structural studies by 1H NMR became feasible with isotope-hybrid phosphoglycerate kinase which is otherwise too large ( Mr ˜ 46,000) for conventional 1H NMR studies. Proton signals of bound substrates were visible in the 1H NMR spectrum even with a substrate-to-enzyme ratio of less than 1/2 (mol/mol). The 2D NOESY spectrum of enzyme-MgdATP-glycerol 3-phosphate complex showed that, although protein concentration was very high (1.5 m M), no intraprotein cross peaks were observed other than those of intraresidue histidine NOE cross peaks. In addition, intrasubstrate NOEs and intermolecular NOEs between histidine and substrate protons were visible at a 1.5/1 substrate/enzyme (mol/mol) ratio. Paramagnetic effects of a substrate analog, Cr(III)ATP, on some of the histidine side chains indicated that the formation of the ternary enzyme-substrate complex causes large conformational changes in the enzyme.

  12. Detection and quantification of Roundup Ready soybean residues in sausage samples by conventional and real-time PCR.

    OpenAIRE

    MARCELINO-GUIMARÃES, F. C.; GUIMARÃES, M. F. M.; DE-BARROS, E. G.

    2009-01-01

    The increasing presence of products derived from genetically modified (GM) plants in human and animal diets has led to the development of detection methods to distinguish biotechnology-derived foods from conventional ones. The conventional and real-time PCR have been used, respectively, to detect and quantify GM residues in highly processed foods. DNA extraction is a critical step during the analysis process. Some factors such as DNA degradation, matrix effects, and the presence of PCR inhibi...

  13. Pesticide Residues in Commercial Lettuce, Onion, and Potato Samples From Bolivia—A Threat to Public Health?

    DEFF Research Database (Denmark)

    Skovgaard, Marlene; Renjel, Susana; Jensen, Olaf Chresten

    2017-01-01

    Bolivia does not have a surveillance program for pesticide residues in food. The few published studies have suggested that pesticide contamination in food may present a public health problem. Data are lacking for all foods except tomatoes and breast milk. In this study 10 potato, 10 onion, and 10...... or together would lead to exposures that exceeded the acceptable daily intake or the acute reference dose. To protect consumers from pesticide poisonings and chronic effects, the development of measures for prevention, control, and monitoring of food contamination by pesticides in Bolivia is suggested....

  14. Evaluation of the QuEChERS sample preparation approach for the analysis of pesticide residues in olives.

    Science.gov (United States)

    Cunha, Sara C; Lehotay, Steven J; Mastovska, Katerina; Fernandes, José O; Beatriz, Maria; Oliveira, P P

    2007-03-01

    This paper describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and cleanup of 16 pesticide residues of interest in olives and olive oil. These products contain a high lipid content, which can adversely affect pesticide recoveries and harm traditional chromatographic systems. For extraction, the main factors (oil and water content) were studied and optimized in experiments to maximize pesticide recoveries. Dispersive SPE with different sorbents was also investigated to minimize matrix coextractives and interferences. For analysis, a new automated DSI device was tested in GC-MS to avoid nonvolatile coextractives from contaminating the instrument. LC-MS/MS with positive ESI was used for those pesticides that were difficult to detect by GC-MS. The final method was validated for olives in terms of recoveries, repeatabilities, and reproducibilities using both detection techniques. The results demonstrated that the method achieved acceptable quantitative recoveries of 70-109% with RSDs < 20% for DSI-GC-MS and 88-130% with RSDs < 10% for LC-MS/MS, and LOQ at or below the regulatory maximum residue limits for the pesticides were achieved.

  15. Residual neutron-induced radionuclides in a soil sample collected in the vicinity of the criticality accident site in Tokai-mura, Japan: A Progress Report

    International Nuclear Information System (INIS)

    Nakanishi, Takashi; Hosotani, Risa; Komura, Kazuhisa; Muroyama, Toshiharu; Kofuji, Hisaki; Murata, Yoshimasa; Kimura, Shinzo; Kumar Sahoo, Sarata; Yonehara, Hidenori; Watanabe, Yoshito; Ban-nai, Tada-aki

    2000-01-01

    Residual neutron-induced radionuclides were measured in a soil sample collected in the vicinity of the location where a criticality accident occurred (in Tokai-mura, from 30 September to 1 October, 1999). Concentrations of 24 Na, 140 La, 122 Sb, 59 Fe, 124 Sb, 46 Sc, 65 Zn, 134 Cs and 60 Co in the soil sample were determined by γ-ray spectrometry, and neutron activation analysis was carried out for selected target elements in the sample. Tentative estimates of the apparent thermal and epithermal neutron fluences which reached the sample were obtained through combined analyses of 59 Fe/ 58 Fe, 124 Sb/ 123 Sb, 46 Sc/ 45 Sc, 65 Zn/ 64 Zn, 134 Cs/ 133 Cs and 60 Co/ 59 Co

  16. Consensus of sample-balanced classifiers for identifying ligand-binding residue by co-evolutionary physicochemical characteristics of amino acids

    KAUST Repository

    Chen, Peng

    2013-01-01

    Protein-ligand binding is an important mechanism for some proteins to perform their functions, and those binding sites are the residues of proteins that physically bind to ligands. So far, the state-of-the-art methods search for similar, known structures of the query and predict the binding sites based on the solved structures. However, such structural information is not commonly available. In this paper, we propose a sequence-based approach to identify protein-ligand binding residues. Due to the highly imbalanced samples between the ligand-binding sites and non ligand-binding sites, we constructed several balanced data sets, for each of which a random forest (RF)-based classifier was trained. The ensemble of these RF classifiers formed a sequence-based protein-ligand binding site predictor. Experimental results on CASP9 targets demonstrated that our method compared favorably with the state-of-the-art. © Springer-Verlag Berlin Heidelberg 2013.

  17. Development of an enzyme-linked immunosorbent assay for seven sulfonamide residues and investigation of matrix effects from different food samples.

    Science.gov (United States)

    Zhang, Hongyan; Wang, Lei; Zhang, Yan; Fang, Guozhen; Zheng, Wenjie; Wang, Shuo

    2007-03-21

    Direct competitive enzyme-linked immunosorbent assays (ELISA) were developed to detect a broad range of sulfonamides in various matrices. Screening for this class of antibiotics in pig muscle, chicken muscle, fish, and egg extracts was accomplished by simple, rapid extraction methods carried out with only phosphate-buffered saline (PBS) buffer. Twenty milliliters of extract solution was added to 4 g of sample to extract the sulfonamide residues, and sample extracts diluted with assay buffer were directly analyzed by ELISA; matrix effects could be avoided with 1:5 dilution of pig muscle, chicken muscle, and egg extracts with PBS and 1:5 dilution of fish extract with 1% bovine serum albumin (BSA)-PBS. For liver sample, the extraction method was a little more complicated; 2 g of sample was added to 20 mL of ethanol, mixed, and then centrifuged. The solvent of 10 mL of the upper liquid was removed, and the residues were dissolved in 10 mL of PBS and then filtered; the filtrate was diluted two-fold with 0.5% BSA-PBS for ELISA. These common methods were able to detect seven sulfonamide residues such as sulfisozole, sulfathiazole, sufameter, sulfamethoxypyridazine, sulfapyridine, sulfamethizole, and sulfachlorpyridazine in pig muscle, liver, chicken muscle, egg, and fish. The assay's detection limits for these compounds were less than 100 microg kg-1. Various extraction methods were tested, and the average recovery (n=3) of 100 microg kg-1 for the matrices was found to range from 77.3 to 123.7%.

  18. MRI-determined liver proton density fat fraction, with MRS validation: Comparison of regions of interest sampling methods in patients with type 2 diabetes.

    Science.gov (United States)

    Vu, Kim-Nhien; Gilbert, Guillaume; Chalut, Marianne; Chagnon, Miguel; Chartrand, Gabriel; Tang, An

    2016-05-01

    To assess the agreement between published magnetic resonance imaging (MRI)-based regions of interest (ROI) sampling methods using liver mean proton density fat fraction (PDFF) as the reference standard. This retrospective, internal review board-approved study was conducted in 35 patients with type 2 diabetes. Liver PDFF was measured by magnetic resonance spectroscopy (MRS) using a stimulated-echo acquisition mode sequence and MRI using a multiecho spoiled gradient-recalled echo sequence at 3.0T. ROI sampling methods reported in the literature were reproduced and liver mean PDFF obtained by whole-liver segmentation was used as the reference standard. Intraclass correlation coefficients (ICCs), Bland-Altman analysis, repeated-measures analysis of variance (ANOVA), and paired t-tests were performed. ICC between MRS and MRI-PDFF was 0.916. Bland-Altman analysis showed excellent intermethod agreement with a bias of -1.5 ± 2.8%. The repeated-measures ANOVA found no systematic variation of PDFF among the nine liver segments. The correlation between liver mean PDFF and ROI sampling methods was very good to excellent (0.873 to 0.975). Paired t-tests revealed significant differences (P sampling methods that exclusively or predominantly sampled the right lobe. Significant correlations with mean PDFF were found with sampling methods that included higher number of segments, total area equal or larger than 5 cm(2) , or sampled both lobes (P = 0.001, 0.023, and 0.002, respectively). MRI-PDFF quantification methods should sample each liver segment in both lobes and include a total surface area equal or larger than 5 cm(2) to provide a close estimate of the liver mean PDFF. © 2015 Wiley Periodicals, Inc.

  19. Selectivity in the sample preparation for the analysis of drug residues in products of animal origin using LC-MS

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Stolker, A.A.M.; Nielen, M.W.F.

    2013-01-01

    Sample preparation is critical in relation to analysis time, sample throughput and therefore analysis costs. Due to recent advances in liquid chromatography-mass spectrometry (LC-MS) instrumentation, the detection of many compounds within one run became possible, and methods for the simultaneous

  20. Application of acetone acetals as water scavengers and derivatization agents prior to the gas chromatographic analysis of polar residual solvents in aqueous samples.

    Science.gov (United States)

    van Boxtel, Niels; Wolfs, Kris; Van Schepdael, Ann; Adams, Erwin

    2015-12-18

    The sensitivity of gas chromatography (GC) combined with the full evaporation technique (FET) for the analysis of aqueous samples is limited due to the maximum tolerable sample volume in a headspace vial. Using an acetone acetal as water scavenger prior to FET-GC analysis proved to be a useful and versatile tool for the analysis of high boiling analytes in aqueous samples. 2,2-Dimethoxypropane (DMP) was used in this case resulting in methanol and acetone as reaction products with water. These solvents are relatively volatile and were easily removed by evaporation enabling sample enrichment leading to 10-fold improvement in sensitivity compared to the standard 10μL FET sample volumes for a selection of typical high boiling polar residual solvents in water. This could be improved even further if more sample is used. The method was applied for the determination of residual NMP in an aqueous solution of a cefotaxime analogue and proved to be considerably better than conventional static headspace (sHS) and the standard FET approach. The methodology was also applied to determine trace amounts of ethylene glycol (EG) in aqueous samples like contact lens fluids, where scavenging of the water would avoid laborious extraction prior to derivatization. During this experiment it was revealed that DMP reacts quantitatively with EG to form 2,2-dimethyl-1,3-dioxolane (2,2-DD) under the proposed reaction conditions. The relatively high volatility (bp 93°C) of 2,2-DD makes it possible to perform analysis of EG using the sHS methodology making additional derivatization reactions superfluous. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Comparison of sample digestion techniques for the determination of trace and residual catalyst metal content in single-wall carbon nanotubes by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grinberg, Patricia, E-mail: patricia.grinberg@nrc.ca [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Sturgeon, Ralph E. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Diehl, Liange de O.; Bizzi, Cezar A. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil); Flores, Erico M.M. [Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil)

    2015-03-01

    A single-wall carbon nanotube material produced by laser ablation of renewable biochar in the presence of Ni and Co catalyst was characterized for residual catalyst (Co and Ni) as well as trace metal impurity content (Fe, Mo, Cr, Pb and Hg) by isotope dilution ICP-MS following sample digestion. Several matrix destruction procedures were evaluated, including a multi-step microwave-assisted acid digestion, dry ashing at 450 °C and microwave-induced combustion with oxygen. Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements. Although laborious to execute, the multi-step microwave-assisted acid digestion proved to be most reliable for recovery of the majority of the analytes, although content of Cr remained biased low for each approach, likely due to its presence as refractory carbide. - Highlights: • Determination of trace and residual catalyst metal content in Single-Wall Carbon Nanotubes by Inductively Coupled Plasma Mass Spectrometry. • Comparative study of digestion methodology combined with high precision isotope dilution ICP-MS for quantitation of elements of toxicologic relevance. • Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements.

  2. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Qingda [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Snowdon, Inc., Monmouth Junction, NJ (United States); University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Keire, David A.; Buhse, Lucinda F.; Trehy, Michael L. [Food and Drug Administration, CDER, Division of Pharmaceutical Analysis, St. Louis, MO (United States); Wood, Richard D. [Snowdon, Inc., Monmouth Junction, NJ (United States); Mital, Dinesh P.; Haque, Syed; Srinivasan, Shankar [University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Moore, Christine M.V.; Nasr, Moheb; Al-Hakim, Ali [Food and Drug Administration, CDER, Office of New Drug Quality Assessment, Silver Spring, MD (United States); Welsh, William J. [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2011-08-15

    Chemometric analysis of a set of one-dimensional (1D) {sup 1}H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D {sup 1}H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS {<=} 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D {sup 1}H NMR spectroscopy

  3. Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Directory of Open Access Journals (Sweden)

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatography – tandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  4. Study of the production of residual evaporation nuclei issued from the spallation reaction of uranium-238 by 1 GeV protons; Etude de la production de noyaux residuels d'evaporation issus de la reaction de spallation de l'uranium-238 par des protons a 1 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Taieb, J

    2000-10-01

    The spallation reaction by high energy protons is one of the envisaged nuclear reactions for production of exotic nuclei. We have measured the production of more than 300 different evaporation residues issued by the spallation reaction of Uranium-238 by 1 GeV protons. We used the reverse kinematics technique in order to produce the relativistic nuclei and therefore to be able to detect those nuclides within a very short time, shorter in most cases than the radioactive disintegration period. The achieved nuclear charge and mass resolution are excellent. They allow a good accuracy on the values of the measured cross-sections (10 to 15%). We have observed for the first time the nuclide Actinium-235 obtained consequently to the loss of 3 protons by the projectile. The measured isotopic distribution are strongly influenced by the mechanism of fission which leads to a strong reduction of the production of the heavy neutron deficient isotopes. We have compared our results to some other measurements achieved with radio-chemical methods at a similar energy. We observed a systematic disagreement of about 40%. Some comparison with the available systematics show that those are presently not able to reproduce the data with a reasonable precision. We could also measure the recoil momentum distribution for each studied isotopes. We show that Goldhaber's model agrees very well with the experiment in case. of 'cold' channels where the evaporation of particles never occurs. On the other hand, when the produced pre-fragment is excited the data show that Goldhaber's model does not reproduce.the data showing the limitation of such an approach. We finally tried to reproduce the measurement of evaporation residue cross-section thanks to the coupling of intra-nuclear cascade and statistical evaporation codes. The influence of the fission process is rather important is the system p+U; we therefore had to account for the dynamical aspect of the fission. We also showed

  5. [Determination of 51 carbamate pesticide residues in vegetables by liquid chromatography-tandem mass spectrometry based on optimization of QuEChERS sample preparation method].

    Science.gov (United States)

    Wang, Lianzhu; Zhou, Yu; Huang, Xiaoyan; Wang, Ruilong; Lin, Zixu; Chen, Yong; Wang, Dengfei; Lin, Dejuan; Xu, Dunming

    2013-12-01

    The raw extracts of six vegetables (tomato, green bean, shallot, broccoli, ginger and carrot) were analyzed using gas chromatography-mass spectrometry (GC-MS) in full scan mode combined with NIST library search to confirm main matrix compounds. The effects of cleanup and adsorption mechanisms of primary secondary amine (PSA) , octadecylsilane (C18) and PSA + C18 on co-extractives were studied by the weight of evaporation residue for extracts before and after cleanup. The suitability of the two versions of QuEChERS method for sample preparation was evaluated for the extraction of 51 carbamate pesticides in the six vegetables. One of the QuEChERS methods was the original un-buffered method published in 2003, and the other was AOAC Official Method 2007.01 using acetate buffer. As a result, the best effects were obtained from using the combination of C18 and PSA for extract cleanup in vegetables. The acetate-buffered version was suitable for the determination of all pesticides except dioxacarb. Un-buffered QuEChERS method gave satisfactory results for determining dioxacarb. Based on these results, the suitable QuEChERS sample preparation method and liquid chromatography-positive electrospray ionization-tandem mass spectrometry under the optimized conditions were applied to determine the 51 carbamate pesticide residues in six vegetables. The analytes were quantified by matrix-matched standard solution. The recoveries at three levels of 10, 20 and 100 microg/kg spiked in six vegetables ranged from 58.4% to 126% with the relative standard deviations of 3.3%-26%. The limits of quantification (LOQ, S/N > or = 10) were 0.2-10 microg/kg except that the LOQs of cartap and thiofanox were 50 microg/kg. The method is highly efficient, sensitive and suitable for monitoring the 51 carbamate pesticide residues in vegetables.

  6. Ionic Liquid-Assisted Liquid-Liquid Microextraction based on the Solidification of Floating Organic Droplet in Sample Preparation for Simultaneous Determination of Herbicide Residues in Fruits.

    Science.gov (United States)

    Vichapong, Jitlada; Santaladchaiyakit, Yanawath; Burakham, Rodjana; Srijaranai, Supalax

    2017-09-01

    An ionic liquid-assisted liquid-liquid microextraction based on the solidification of floating organic droplet (ILSFODLLME) was investigated for analysis of four herbicide residues (i.e. simazine, atrazine, propazine, and linuron) by high performance liquid chromatography. For ILSFOD-LLME, the optimal extraction conditions were 5% w/v Na2SO4, 30 μL [C4MIM][PF6]RTIL, 100 μL of 1-octanol, ultrasonication time 30 s and centrifugation at 5000 rpm for 5 min. Under the optimal conditions, linearity was obtained within the range of 0.1-1000 μg kg-1, with the correlation coefficients greater than 0.999. The high enrichment factors of the target analytes were in the range of 64.5-139.9 and low limit of detection could be obtained. A modified QuEChERS was applied for fruit sample preparation before analysis. Matrix effects were also investigated using matrix matched standards for construction of the calibration graph. The proposed method has been successfully applied for extraction and preconcentration of herbicide residues in fruit samples, and good recoveries in the range of 87.32% to 99.93% were obtained.

  7. Can cadaverous pollution from environmental lead misguide to false positive results in the histochemical determination of gunshot residues? Study on cadaveric skin samples.

    Science.gov (United States)

    Boracchi, Michele; Andreola, Salvatore; Collini, Federica; Gentile, Guendalina; Maciocco, Francesca; Maghin, Francesca; Zoja, Riccardo

    2017-08-01

    Histochemical determination of lead in gunshot residues (GSR) raises the question of possible environmental contamination by heavy metals. Authors assess the specificity of the Sodium Rhodizonate Test in the search of lead derived from environmental pollution. Sodium Rhodizonate Test and 5% HCl Sodium Rhodizonate test were applied to skin samples taken from two groups of victims, whose cause of death was not related to gunshot wounds: group A included 25 corpses found in open spaces after a long time; group B included 16 corpses exhumed after a period of 11 years. The use of these histochemical tests to skin samples from these two groups did not show metal debris histochemically similar to the lead present in GSR. These tests were confirmed to be specific in highlighting the GSR coming from gunshot, without being affected by the potential environmental contamination of the heavy metal pollutants, coming from air or soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Forensic analysis of high explosives residues in post-blast water samples employing solid phase extraction for analyte pro-concentration

    International Nuclear Information System (INIS)

    Umi Kalsom Ahmad; Rajendran, Sumathy; Ling, Lee Woan

    2008-01-01

    Nitro aromatic, nitramine and nitrate ester compounds are a major group of high order explosive or better known as military explosives. Octahydro-1,3,5,7-tetrazocine (HMX), 1,3,5-hexahydro-1,3,5-trinitro triazine (RDX), 2,4,6-trinitro-toluene (TNT), pentaerythritol tetranitrate (PETN) and 2,4-dinitrotoluene (2,4-DNT) are secondary high explosives classified as most commonly used explosives components. There is an increasing demand for pre-concentration of these compounds in water samples as the sensitivity achieved by instrumental analytical methods for these high explosives residues are the main drawback in the application at trace levels for forensic analysis. Hence, a simple cartridge solid phase extraction (SPE) procedure was optimized as the off-line extraction and pre-concentration method to enhance the detection limit of high explosive residues using micellar electrokinetic chromatography (MEKC) and gas chromatography with electron-capture detection (GC-ECD) methods. The SPE cartridges utilized LiChrolut EN as the SPE adsorbent. By emplying pre-concentration using SPE, the detection limits of the target analytes in water sample were lowered by more than 1000 times with good percentage recovery (>87%) for MEKC method and lowered by 120 times with more than 2 % percentage recovery for GC-ECD methods. In order to test the feasibility of the developed method to real cases, post-blast water samples were analyzed. The post-blast water samples which were collected from Baling Bom training range, Ulu Kinta, Perak contained RDX and PETN in the range of 0.05 - 0.17 ppm and 0.0124 - 0.0390 ppm respectively. (author)

  9. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiangwei [Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101 (China); College of Science, China Agricultural University, Beijing 100193 (China); Xing, Zhuokan [College of Science, China Agricultural University, Beijing 100193 (China); Liu, Fengmao, E-mail: liufengmao@cau.edu.cn [College of Science, China Agricultural University, Beijing 100193 (China); Zhang, Xu [College of Science, China Agricultural University, Beijing 100193 (China)

    2015-05-22

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L{sup −1}. The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

  10. [Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometry].

    Science.gov (United States)

    Zhu, Jing; Zhou, Xin; Fu, Chunmei; Liu, Sankang; Li, Zhangwan

    2004-11-01

    Solid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

  11. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    International Nuclear Information System (INIS)

    You, Xiangwei; Xing, Zhuokan; Liu, Fengmao; Zhang, Xu

    2015-01-01

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L −1 . The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly

  12. Evaluation of bi-functionalized mesoporous silicas as reversed phase/cation-exchange mixed-mode sorbents for multi-residue solid phase extraction of veterinary drug residues in meat samples.

    Science.gov (United States)

    Casado, Natalia; Pérez-Quintanilla, Damián; Morante-Zarcero, Sonia; Sierra, Isabel

    2017-04-01

    A SBA-15 type mesoporous silica was synthesized and bi-functionalized with octadecylsilane (C18) or octylsilane (C8), and sulfonic acid (SO 3 - ) groups in order to obtain materials with reversed-phase/strong cation-exchange mixed-mode retention mechanism. The resulting hybrid materials (SBA-15-C18-SO 3 - and SBA-15-C8-SO 3 - ) were comprehensively characterized. They showed high surface area, high pore volume and controlled porous size. Elemental analysis of the materials revealed differences in the amount of C18 and C8. SBA-15-C18-SO 3 - contained 0.19mmol/g of C18, while SBA-15-C8-SO 3 - presented 0.54mmol/g of C8. The SO 3 - groups anchored to the silica surface of the pore walls were 0.20 and 0.09mmol/g, respectively. The bi-functionalized materials were evaluated as SPE sorbents for the multi-residue extraction of 26 veterinary drug residues in meat samples using ultra-high-performance liquid chromatography coupled to mass spectrometry detector (UHPLC-MS/MS). Different sorbent amounts (100 and 200mg) and organic solvents were tested to optimize the extraction procedure. Both silicas showed big extraction potential and were successful in the extraction of the target analytes. The mixed-mode retention mechanism was confirmed by comparing both silicas with SBA-15 mesoporous silica mono-functionalized with C18 and C8. Best results were achieved with 200mg of SBA-15-C18-SO 3 - obtaining recoveries higher than 70% for the majority of analytes. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. The influence of the calibration standard and the chemical composition of the water samples residue in the counting efficiency of proportional detectors for gross alpha and beta counting. Application on the radiologic control of the IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Santos, Cecilia Martins

    2003-01-01

    In this work the efficiency calibration curves of thin-window and low background gas-flow proportional counters were determined for calibration standards with different energies and different absorber thicknesses. For the gross alpha counting we have used 241 Am and natural uranium standards and for the gross beta counting we have used 90 Sr/ 90 Y and 137 Cs standards in residue thicknesses ranging from 0 to approximately 18 mg/cm 2 . These sample thicknesses were increased with a previously determined salted solution prepared simulating the chemical composition of the underground water of IPEN The counting efficiency for alpha emitters ranged from 0,273 +- 0,038 for a weightless residue to only 0,015 +- 0,002 in a planchet containing 15 mg/cm 2 of residue for 241 Am standard. For natural uranium standard the efficiency ranged from 0,322 +- 0,030 for a weightless residue to 0,023 +- 0,003 in a planchet containing 14,5 mg/cm 2 of residue. The counting efficiency for beta emitters ranged from 0,430 +- 0,036 for a weightless residue to 0,247 +- 0,020 in a planchet containing 17 mg/cm 2 of residue for 137 Cs standard. For 90 Sr/ 90 Y standard the efficiency ranged from 0,489 +- 0,041 for a weightless residue to 0,323 +- 0,026 in a planchet containing 18 mg/cm 2 of residue. Results make evident the counting efficiency variation with the alpha or beta emitters energies and the thickness of the water samples residue. So, the calibration standard, the thickness and the chemical composition of the residue must always be considered in the gross alpha and beta radioactivity determination in water samples. (author)

  14. Proton therapy

    International Nuclear Information System (INIS)

    Smith, Alfred R

    2006-01-01

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  15. A supersensitive silver nanoprobe based aptasensor for low cost detection of malathion residues in water and food samples

    Science.gov (United States)

    Bala, Rajni; Mittal, Sherry; Sharma, Rohit K.; Wangoo, Nishima

    2018-05-01

    In the present study, we report a highly sensitive, rapid and low cost colorimetric monitoring of malathion (an organophosphate insecticide) employing a basic hexapeptide, malathion specific aptamer (oligonucleotide) and silver nanoparticles (AgNPs) as a nanoprobe. AgNPs are made to interact with the aptamer and peptide to give different optical responses depending upon the presence or absence of malathion. The nanoparticles remain yellow in color in the absence of malathion owing to the binding of aptamer with peptide which otherwise tends to aggregate the particles because of charge based interactions. In the presence of malathion, the agglomeration of the particles occurs which turns the solution orange. Furthermore, the developed aptasensor was successfully applied to detect malathion in various water samples and apple. The detection offered high recoveries in the range of 89-120% with the relative standard deviation within 2.98-4.78%. The proposed methodology exhibited excellent selectivity and a very low limit of detection i.e. 0.5 pM was achieved. The developed facile, rapid and low cost silver nanoprobe based on aptamer and peptide proved to be potentially applicable for highly selective and sensitive colorimetric sensing of trace levels of malathion in complex environmental samples. Figure S2. HPLC Chromatogram of KKKRRR. Figure S3. UV- Visible spectra of AgNPs in the presence of increasing peptide concentrations. Inset shows respective color changes of AgNPs with peptide concentrations ranging from 0.1 mM to 100 mM (a to e). Figure S4. UV- Visible spectra of AgNPs in the presence 10 mM peptide and varying aptamer concentrations. Inset shows the corresponding color changes. a to e shows aptamer concentrations ranging from 10 nM to 1000 nM. Figure S5. Interference Studies. Ratio of A520 nm/390 nm of AgNPs in the presence of 10 mM peptide, 500 nM aptamer, 0.5 nM malathion and 0.5 mM interfering components i.e. sodium, potassium, calcium, alanine, arginine

  16. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  17. Elemental quantification of large gunshot residues

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, A. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil); Silva, L.M. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil); Forensic Institute of Porto Alegre, Av. Princesa Isabel 1056, CEP 90230-010 Porto Alegre, RS (Brazil); Souza, C.T. de; Stori, E.M. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Boufleur, L.A. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil); Amaral, L. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); and others

    2015-04-01

    In the present work we embarked on the evaluation of the Sb/Pb, Ba/Pb and Sb/Ba elemental ratios found in relatively large particles (of the order of 50–150 μm across) ejected in the forward direction when a gun is fired. These particles are commonly referred to as gunshot residues (GSR). The aim of this work is to compare the elemental ratios of the GSR with those found in the primer of pristine cartridges in order to check for possible correlations. To that end, the elemental concentration of gunshot residues and the respective ammunition were investigated through PIXE (Particle-Induced X-ray Emission) and micro-PIXE techniques. The ammunition consisted of a .38 SPL caliber (ogival lead type) charged in a Taurus revolver. Pristine cartridges were taken apart for the PIXE measurements. The shooting sessions were carried out in a restricted area at the Forensic Institute at Porto Alegre. Residues ejected at forward directions were collected on a microporous tape. The PIXE experiments were carried out employing 2.0 MeV proton beams with a beam spot size of 1 mm{sup 2}. For the micro-PIXE experiments, the samples were irradiated with 2.2 MeV proton beams of 2 × 2 μm{sup 2}. The results found for the ratios of Sb/Pb, Ba/Pb and Sb/Ba do not correlate with those stemming from the analysis of the primer.

  18. Elemental quantification of large gunshot residues

    International Nuclear Information System (INIS)

    Duarte, A.; Silva, L.M.; Souza, C.T. de; Stori, E.M.; Boufleur, L.A.; Amaral, L.

    2015-01-01

    In the present work we embarked on the evaluation of the Sb/Pb, Ba/Pb and Sb/Ba elemental ratios found in relatively large particles (of the order of 50–150 μm across) ejected in the forward direction when a gun is fired. These particles are commonly referred to as gunshot residues (GSR). The aim of this work is to compare the elemental ratios of the GSR with those found in the primer of pristine cartridges in order to check for possible correlations. To that end, the elemental concentration of gunshot residues and the respective ammunition were investigated through PIXE (Particle-Induced X-ray Emission) and micro-PIXE techniques. The ammunition consisted of a .38 SPL caliber (ogival lead type) charged in a Taurus revolver. Pristine cartridges were taken apart for the PIXE measurements. The shooting sessions were carried out in a restricted area at the Forensic Institute at Porto Alegre. Residues ejected at forward directions were collected on a microporous tape. The PIXE experiments were carried out employing 2.0 MeV proton beams with a beam spot size of 1 mm 2 . For the micro-PIXE experiments, the samples were irradiated with 2.2 MeV proton beams of 2 × 2 μm 2 . The results found for the ratios of Sb/Pb, Ba/Pb and Sb/Ba do not correlate with those stemming from the analysis of the primer

  19. Determination of neonicotinoid pesticides residues in agricultural samples by solid-phase extraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xie, Wen; Han, Chao; Qian, Yan; Ding, Huiying; Chen, Xiaomei; Xi, Junyang

    2011-07-15

    This work reports a new sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, confirmation and quantification of six neonicotinoid pesticides (dinotefuran, thiamethoxam, clothiandin, imidacloprid, acetamiprid and thiacloprid) in agricultural samples (chestnut, shallot, ginger and tea). Activated carbon and HLB solid-phase extraction cartridges were used for cleaning up the extracts. Analysis is performed by LC-MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Quantification was carried by the internal standard method with D(4)-labeled imidacloprid. The method showed excellent linearity (R(2)≥0.9991) and precision (relative standard deviation, RSD≤8.6%) for all compounds. Limits of quantification (LOQs) were 0.01 mg kg(-1) for chestnut, shallot, ginger sample and 0.02 mg kg(-1) for tea sample. The average recoveries, measured at three concentrations levels (0.01 mg kg(-1), 0.02 mg kg(-1) and 0.1 mg kg(-1) for chestnut, shallot, ginger sample, 0.02 mg kg(-1), 0.04 mg kg(-1) and 0.2 mg kg(-1) for tea sample), were in the range 82.1-108.5%. The method was satisfactorily validated for the analysis of 150 agricultural samples (chestnut, shallot, ginger and tea). Imidacloprid and acetamiprid were detected at concentration levels ranging from 0.05 to 3.6 mg kg(-1). Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Protein proton-proton dynamics from amide proton spin flip rates

    International Nuclear Information System (INIS)

    Weaver, Daniel S.; Zuiderweg, Erik R. P.

    2009-01-01

    Residue-specific amide proton spin-flip rates K were measured for peptide-free and peptide-bound calmodulin. K approximates the sum of NOE build-up rates between the amide proton and all other protons. This work outlines the theory of multi-proton relaxation, cross relaxation and cross correlation, and how to approximate it with a simple model based on a variable number of equidistant protons. This model is used to extract the sums of K-rates from the experimental data. Error in K is estimated using bootstrap methodology. We define a parameter Q as the ratio of experimental K-rates to theoretical K-rates, where the theoretical K-rates are computed from atomic coordinates. Q is 1 in the case of no local motion, but decreases to values as low as 0.5 with increasing domination of sidechain protons of the same residue to the amide proton flips. This establishes Q as a monotonous measure of local dynamics of the proton network surrounding the amide protons. The method is applied to the study of proton dynamics in Ca 2+ -saturated calmodulin, both free in solution and bound to smMLCK peptide. The mean Q is 0.81 ± 0.02 for free calmodulin and 0.88 ± 0.02 for peptide-bound calmodulin. This novel methodology thus reveals the presence of significant interproton disorder in this protein, while the increase in Q indicates rigidification of the proton network upon peptide binding, confirming the known high entropic cost of this process

  1. UNE-EN ISO/IEC 17025:2005-accredited method for the determination of pesticide residues in fruit and vegetable samples by LC-MS/MS.

    Science.gov (United States)

    Camino-Sánchez, F J; Zafra-Gómez, A; Oliver-Rodríguez, B; Ballesteros, O; Navalón, A; Crovetto, G; Vílchez, J L

    2010-11-01

    A rapid, simple and sensitive multi-residue method was developed and validated for the simultaneous quantification and confirmation of 69 pesticides in fruit and vegetables using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted following the quick, easy, cheap, effective, rugged and safe method known as QuEChERS. Mass spectrometric conditions were individually optimised for each analyte in order to achieve maximum sensitivity in multiple reaction monitoring (MRM) mode. Using the developed chromatographic conditions, 69 pesticides can be separated in less than 17 min. Two selected reaction monitoring (SRM) assays were used for each pesticide to obtain simultaneous quantification and identification in one run. With this method in SRM mode, more than 150 pesticides can be analysed and quantified, but their confirmation is not possible in all cases according to the European regulations on pesticide residues. Nine common representative matrices (zucchini, melon, cucumber, watermelon, tomato, garlic, eggplant, lettuce and pepper) were selected to investigate the effect of different matrices on recovery and precision. Mean recoveries ranged from 70% to 120%, with relative standard deviations (RSDs) lower than 20% for all the pesticides. The proposed method was applied to the analysis of more than 2000 vegetable samples from the extensive greenhouse cultivation in the province of Almeria, Spain, during one year. The methodology combines the advantages of both QuEChERS and LC-MS/MS producing a very rapid, sensitive, accurate and reliable procedure that can be applied in routine analytical laboratories. The method was validated and accredited according to UNE-EN-ISO/IEC 17025:2005 international standard (accreditation number 278/LE1027).

  2. Using solvent-free sample preparation to promote protonation of poly(ethylene oxide)s with labile end-groups in matrix-assisted laser desorption/ionisation.

    Science.gov (United States)

    Mazarin, Michael; Phan, Trang N T; Charles, Laurence

    2008-12-01

    Protonation is usually required to observe intact ions during matrix-assisted laser desorption/ionization (MALDI) of polymers containing fragile end-groups while cation adduction induces chain-end degradation. These polymers, generally obtained via living free radical polymerization techniques, are terminated with a functionality in which a bond is prone to homolytic cleavage, as required by the polymerization process. A solvent-free sample preparation method was used here to avoid salt contaminant from the solvent traditionally used in the dried-droplet MALDI procedure. Solvent-based and solvent-free sample preparations were compared for a series of three poly(ethylene oxide) polymers functionalized with a labile end-group in a nitroxide-mediated polymerization reaction, using 2,4,6-trihydroxyacetophenone (THAP) as the matrix without any added salt. Intact oligomer ions could only be produced as protonated molecules in solvent-free MALDI while sodium adducts of degraded polymers were formed from the dried-droplet samples. Although MALDI analysis was performed at the laser threshold, fragmentation of protonated macromolecules was still observed to occur. However, in contrast to sodiated molecules, dissociation of protonated oligomers does not involve the labile C--ON bond of the end-group. As the macromolecule size increased, protonation appeared to be less efficient and sodium adduction became the dominant ionization process, although no sodium salt was added in the preparation. Formation of sodiated degraded macromolecules would be dictated by increasing cation affinity as the size of the oligomers increases and would reveal the presence of salts at trace levels in the MALDI samples.

  3. A Qualitative Interpretation of Residual Magnetic Anomaly using ...

    African Journals Online (AJOL)

    A Qualitative Interpretation of Residual Magnetic Anomaly using Ground ... The magnetic data was collected using a G816 proton precision magnetometer. ... Analysis of residual anomaly graph reveals the existence of some structural features ...

  4. Sampling and Analysis Plan for Assessment of LANL-Derived Residual Radionuclides in Soils within Tract A-16-e for Land Conveyance

    Energy Technology Data Exchange (ETDEWEB)

    Gillis, Jessica [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    Public Law 105-119 directs the U.S. Department of Energy (DOE) to convey or transfer parcels of land to the Incorporated County of Los Alamos or their designees and to the Department of Interior, Bureau of Indian Affairs, in trust for the Pueblo de San Ildefonso. Los Alamos National Security is tasked to support DOE in conveyance and/or transfer of identified land parcels no later than September 2022. Under DOE Order 458.1, Radiation Protection of the Public and the Environment (O458.1, 2013), and Los Alamos National Laboratory (LANL) implementing Policy 412 (P412, 2014a), real property with the potential to contain residual radioactive material must meet the criteria for clearance and release to the public. This Sampling and Analysis Plan (SAP) investigates Tract A-16-e and proposes 50 project-specific soil samples for use in radiological clearance decisions consistent with LANL Procedure ENV-ES-TP-238 (2015a) and guidance in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM, 2000).

  5. Sampling and Analysis Plan for Assessment of LANL-Derived Residual Radionuclides in Soils within Tract A-16-e for Land Conveyance

    International Nuclear Information System (INIS)

    Gillis, Jessica; Ruedig, Elizabeth

    2016-01-01

    Public Law 105-119 directs the U.S. Department of Energy (DOE) to convey or transfer parcels of land to the Incorporated County of Los Alamos or their designees and to the Department of Interior, Bureau of Indian Affairs, in trust for the Pueblo de San Ildefonso. Los Alamos National Security is tasked to support DOE in conveyance and/or transfer of identified land parcels no later than September 2022. Under DOE Order 458.1, Radiation Protection of the Public and the Environment (O458.1, 2013), and Los Alamos National Laboratory (LANL) implementing Policy 412 (P412, 2014a), real property with the potential to contain residual radioactive material must meet the criteria for clearance and release to the public. This Sampling and Analysis Plan (SAP) investigates Tract A-16-e and proposes 50 project-specific soil samples for use in radiological clearance decisions consistent with LANL Procedure ENV-ES-TP-238 (2015a) and guidance in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM, 2000).

  6. A parametric study of laser spot size and coverage on the laser shock peening induced residual stress in thin aluminium samples

    Directory of Open Access Journals (Sweden)

    M. Sticchi

    2015-07-01

    Full Text Available Laser Shock Peening is a fatigue enhancement treatment using laser energy to induce compressive Residual Stresses (RS in the outer layers of metallic components. This work describes the variations of introduced RS-field with peen size and coverage for thin metal samples treated with under-water-LSP. The specimens under investigation were of aluminium alloy AA2024-T351, AA2139-T3, AA7050-T76 and AA7075-T6, with thickness 1.9 mm. The RS were measured by using Hole Drilling with Electronic Speckle Pattern Interferometry and X-ray Diffraction. Of particular interest are the effects of the above mentioned parameters on the zero-depth value, which gives indication of the amount of RS through the thickness, and on the value of the surface compressive stresses, which indicates the magnitude of induced stresses. A 2D-axisymmetrical Finite Element model was created for a preliminary estimation of the stress field trend. From experimental results, correlated with numerical and analytical analysis, the following conclusions can be drawn: increasing the spot size the zero-depth value increases with no significant change of the maximum compressive stress; the increase of coverage leads to significant increase of the compressive stress; thin samples of Al-alloy with low Hugoniot Elastic Limit (HEL reveal deeper compression field than alloy with higher HEL value.

  7. Experimental Analysis of Residual Stresses in Samples of Austenitic Stainless Steel Welded on Martensitic Stainless Steel Used for Kaplan Blades Repairs

    Directory of Open Access Journals (Sweden)

    Vasile Cojocaru

    2011-01-01

    Full Text Available Residual stresses occur in materials as a result of mechanical processes: welding, machining, grinding etc. If residual stresses reach high values they can accelerate the occurrence of cracks and erosion of material. An experimental research was made in order to study the occurrence of residual stresses in the repaired areas of hydraulic turbine components damaged by cavitation erosion. An austenitic stainless steel was welded in various layer thicknesses on a martensitic stainless steel base. The residual stresses were determined using the hole drilling strain gage method.

  8. Surface, structural and tensile properties of proton beam irradiated zirconium

    Science.gov (United States)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 1013 to 1 × 1016 protons/cm2. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples' surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson-Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  9. Orthogonal identification of gunshot residue with complementary detection principles of voltammetry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy: sample, screen, and confirm.

    Science.gov (United States)

    O'Mahony, Aoife M; Samek, Izabela A; Sattayasamitsathit, Sirilak; Wang, Joseph

    2014-08-19

    Field-deployable voltammetric screening coupled with complementary laboratory-based analysis to confirm the presence of gunshot residue (GSR) from the hands of a subject who has handled, loaded, or discharged a firearm is described. This protocol implements the orthogonal identification of the presence of GSR utilizing square-wave stripping voltammetry (SWSV) as a rapid screening tool along with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to confirm the presence of the characteristic morphology and metal composition of GSR particles. This is achieved through the judicious modification of the working electrode of a carbon screen-printed electrode (CSPE) with carbon tape (used in SEM analysis) to fix and retain a sample. A comparison between a subject who has handled and loaded a firearm and a subject who has had no contact with GSR shows the significant variations in voltammetric signals and the presence or absence of GSR-consistent particles and constituent metals. This initial electrochemical screening has no effect on the integrity of the metallic particles, and SEM/EDX analysis conducted prior to and postvoltammetry show no differences in analytical output. The carbon tape is instrumental in retaining the GSR sample after electrochemical analysis, supported by comparison with orthogonal detection at a bare CSPE. This protocol shows great promise as a two-tier detection system for the presence of GSR from the hands of a subject, whereby initial screening can be conducted rapidly onsite by minimally trained operators; confirmation can follow at the same substrate to substantiate the voltammetric results.

  10. Measurement methodology of vegetable samples from an area affected by residual contamination due to uranium mining sterile; Metodologia de medida de muestras vegetales procedentes de un terreno afectado por contaminacion residual debida a esteriles de mineria de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, N.; Suarez, J. A.; Yague, L.; Ortiz Gandia, M. I.; Marijuan, M. J.; Garcia, E.; Ortiz, T.; Alvarez, A.

    2013-07-01

    This paper presents the methodology established for radiological characterization of plant material generated during the first stage of the realization of a movement of land in an area of land affected by residual contamination due to the burial of sterile of uranium mining. (Author)

  11. Proton Beam Writing

    International Nuclear Information System (INIS)

    Rajta, I.; Szilasi, S.Z.; Csige, I.; Baradacs, E.

    2005-01-01

    Complete text of publication follows. Refractive index depth profile in PMMA due to proton irradiation Proton Beam Writing has been successfully used to create buried channel waveguides in PMMA, which suggested that proton irradiation increases the refractive index. To investigate this effect, PMMA samples were irradiated by 1.7-2.1 MeV proton beam. Spectroscopic Ellipsometry has been used to investigate the depth profile of the refractive index. An increase of the refractive index was observed in the order of 0.01, which is approximately one order of magnitude higher than the detection limit. The highest increase of the refractive index occurs at the end of range, i.e. we found a good correlation with the Bragg curve of the energy loss. Hardness changes in PMMA due to proton beam micromachining As protons penetrate a target material and lose their energy according to the Bragg curve, the energy loss is different at different depths. This causes depth-dependent changes of some physical properties in the target material (e.g. refractive index, hardness). In order to characterize the changes of hardness and other mechanical properties as a function of beam penetration depth, systematic investigations have been performed on PMMA, the most common resist material used in proton beam micromachining. Silicon check valve made by proton beam micromachining The possible application of Proton Beam Micromachining (PBM) has been demonstrated by a few authors for creating 3D Si microstructures. In this work we present alternative methods for the formation of a simple a non-return valve for microfluidic applications. Two different approaches have been applied, in both cases we exploited characteristic features of the PBM technique and the selective formation and dissolution of porous Si over the implantation damaged areas. In the first case we implanted 10 μm thick cantilever-type membrane of the valve normally to the crystal surface and at 30-60 degrees to the sidewalls of the

  12. Surface, structural and tensile properties of proton beam irradiated zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo, E-mail: yongskim@hanyang.ac.kr

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 10{sup 13} to 1 × 10{sup 16} protons/cm{sup 2}. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples’ surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson–Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  13. Do protons decay

    International Nuclear Information System (INIS)

    Litchfield, P.J.

    1984-09-01

    The experimental status of proton decay is reviewed after the Leipzig International conference, July 1984. A brief comparative description of the currently active experiments is given. From the overall samples of contained events it can be concluded that the experiments are working well and broadly agree with each other. The candidates for proton decay from each experiment are examined. Although several experiments report candidates at a higher rate than expected from background calculations, the validity of these calculations is still open to doubt. (author)

  14. Residual stresses

    International Nuclear Information System (INIS)

    Sahotra, I.M.

    2006-01-01

    The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

  15. Proton decay theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

  16. Risk-based approach to developing a national residue sampling plan for testing under European Union regulation for veterinary medicinal products and coccidiostat feed additives in domestic animal production.

    Science.gov (United States)

    Danaher, Martin; Shanahan, Conor; Butler, Francis; Evans, Rhodri; O'Sullivan, Dan; Glynn, Denise; Camon, Tim; Lawlor, Peadar; O'Keeffe, Michael

    2016-07-01

    A ranking system for veterinary medicinal products and coccidiostat feed additives has been developed as a tool to be applied in a risk-based approach to the residue testing programme for foods of animal origin in the Irish National Residue Control Plan (NRCP). Three characteristics of substances that may occur as residues in food are included in the developed risk ranking system: Potency, as measured by the acceptable daily intake assigned by the European Medicines Agency Committee for Medicinal Products for Veterinary Use, to each substance; Usage, as measured by the three factors of Number of Doses, use on Individual animals or for Group treatment, and Withdrawal Period; and Residue Occurrence, as measured by the number of Non-Compliant Samples in the NRCP. For both Number of Doses and Non-Compliant Samples, data for the 5-year period 2008-12 have been used. The risk ranking system for substances was developed for beef cattle, sheep and goats, pigs, chickens and dairy cattle using a scoring system applied to the various parameters described above to give an overall score based on the following equation: Potency × Usage (Number of Doses + Individual/Group Use + Withdrawal Period) × Residue Occurrence. Applying this risk ranking system, the following substances are ranked very highly: antimicrobials such as amoxicillin (for all species except pigs), marbofloxacillin (for beef cattle), oxytetracycline (for all species except chickens), sulfadiazine with trimethoprim (for pigs and chickens) and tilmicosin (for chickens); antiparasitic drugs, such as the benzimidazoles triclabendazole (for beef and dairy cattle), fenbendazole/oxfendazole (for sheep/goats and dairy cattle) and albendazole (for dairy cattle), the avermectin ivermectin (for beef cattle), and anti-fluke drugs closantel and rafoxanide (for sheep/goats); the anticoccidials monensin, narasin, nicarbazin and toltrazuril (for chickens). The risk ranking system described is a relatively simple system

  17. Proton therapy

    International Nuclear Information System (INIS)

    Jongen, Y.

    1995-01-01

    Ideal radiotherapy deposits a large amount of energy in the tumour volume, and none in the surrounding healthy tissues. Proton therapy comes closer to this goal because of a greater concentration of dose, well defined proton ranges and points of energy release which are precisely known - the Bragg peak1. In the past, the development of clinical proton therapy has been hampered by complexity, size, and cost. To be clinically effective, energies of several hundred MeV are required; these were previously unavailable for hospital installations, and pioneering institutions had to work with complex, inadequate equipment originally intended for nuclear physics research. Recently a number of specialist organizations and commercial companies have been working on dedicated systems for proton therapy. One, IBA of Belgium, has equipment for inhouse hospital operation which encompasses a complete therapy centre, delivered as a turnkey package and incorporating a compact, automated, higher energy cyclotron with isocentric gantries. Their system will be installed at Massachusetts General Hospital, Boston. The proton therapy system comprises: - a 235 MeV isochronous cyclotron to deliver beams of up to 1.5 microamps, but with a hardware limitation to restrict the maximum possible dose; - variable energy beam (235 to 70 MeV ) with energy spread and emittance verification; - a beam transport and switching system to connect the exit of the energy selection system to the entrances of a number of gantries and fixed beamlines. Along the beam transport system, the beam characteristics are monitored with non-interceptive multiwire ionization chambers for automatic tuning; - gantries fitted with nozzles and beamline elements for beam control; both beam scattering and beam wobbling techniques are available for shaping the beam;

  18. Variability of matrix effects in liquid and gas chromatography - mass spectrometry analysis of pesticide residues after QuEChERS sample preparation of different food crops

    Science.gov (United States)

    Gas and liquid chromatography (GC and LC) coupled to sophisticated mass spectrometry (MS) instruments are among the most powerful analytical tools currently available to monitor pesticide residues in food, among other applications. However, both GC-MS and LC-MS are susceptible to matrix effects whi...

  19. Consensus of sample-balanced classifiers for identifying ligand-binding residue by co-evolutionary physicochemical characteristics of amino acids

    KAUST Repository

    Chen, Peng

    2013-01-01

    Protein-ligand binding is an important mechanism for some proteins to perform their functions, and those binding sites are the residues of proteins that physically bind to ligands. So far, the state-of-the-art methods search for similar, known

  20. Residual stresses

    International Nuclear Information System (INIS)

    Macherauch, E.

    1978-01-01

    Residual stresses are stresses which exist in a material without the influence of external powers and moments. They come into existence when the volume of a material constantly changes its form as a consequence of mechanical, thermal, and/or chemical processes and is hindered by neighbouring volumes. Bodies with residual stress are in mechanical balance. These residual stresses can be manifested by means of all mechanical interventions disturbing this balance. Acoustical, optical, radiological, and magnetical methods involving material changes caused by residual stress can also serve for determining residual stress. Residual stresses have an ambivalent character. In technical practice, they are feared and liked at the same time. They cause trouble because they can be the cause for unexpected behaviour of construction elements. They are feared since they can cause failure, in the worst case with catastrophical consequences. They are appreciated, on the other hand, because, in many cases, they can contribute to improvements of the material behaviour under certain circumstances. But they are especially liked for their giving convenient and (this is most important) mostly uncontrollable explanations. For only in very few cases we have enough knowledge and possibilities for the objective evaluation of residual stresses. (orig.) [de

  1. Application of multi-station time sequence aerosol sampling and proton induced x-ray emission analysis techniques to the St. Louis regional air pollution study for investigating sulfur-trace metal relationships

    International Nuclear Information System (INIS)

    Pilotte, J.O.; Nelson, J.W.; Winchester, J.W.

    1976-01-01

    Time sequence streaker samplers, employing Nuclepore filters for aerosol collection, have been deployed over the 25-station St. Louis regional air monitoring network and operated for the months of July and August 1975 so as to determine aerosol composition variations with 2-hour time resolution. Elemental analysis of the 84 individual time steps per station for each week of sampling is carried out by 5 MeV proton irradiation and X-ray counting by Si(Li) detector, using a Van de Graaff accelerator with a special automated step drive sample handling device. Computer resolution of the X-ray spectra for the elements S, Cl, K, Ca, Ti, V, Cr, Mn, Fe Ni, Cu, Zn, Br, and Pb is carried out at a rate equal to the proton irradiation rate, five minutes or less for each time step analysis. The aerosol particle sampling equipment and conditions have been designed to take advantage of the high sensitivity of PIXE analysis, in the nanogram range for the elements determined

  2. Solid-state NMR analysis of membrane proteins and protein aggregates by proton detected spectroscopy

    International Nuclear Information System (INIS)

    Zhou, Donghua H.; Nieuwkoop, Andrew J.; Berthold, Deborah A.; Comellas, Gemma; Sperling, Lindsay J.; Tang, Ming; Shah, Gautam J.; Brea, Elliott J.; Lemkau, Luisel R.; Rienstra, Chad M.

    2012-01-01

    Solid-state NMR has emerged as an important tool for structural biology and chemistry, capable of solving atomic-resolution structures for proteins in membrane-bound and aggregated states. Proton detection methods have been recently realized under fast magic-angle spinning conditions, providing large sensitivity enhancements for efficient examination of uniformly labeled proteins. The first and often most challenging step of protein structure determination by NMR is the site-specific resonance assignment. Here we demonstrate resonance assignments based on high-sensitivity proton-detected three-dimensional experiments for samples of different physical states, including a fully-protonated small protein (GB1, 6 kDa), a deuterated microcrystalline protein (DsbA, 21 kDa), a membrane protein (DsbB, 20 kDa) prepared in a lipid environment, and the extended core of a fibrillar protein (α-synuclein, 14 kDa). In our implementation of these experiments, including CONH, CO(CA)NH, CANH, CA(CO)NH, CBCANH, and CBCA(CO)NH, dipolar-based polarization transfer methods have been chosen for optimal efficiency for relatively high protonation levels (full protonation or 100 % amide proton), fast magic-angle spinning conditions (40 kHz) and moderate proton decoupling power levels. Each H–N pair correlates exclusively to either intra- or inter-residue carbons, but not both, to maximize spectral resolution. Experiment time can be reduced by at least a factor of 10 by using proton detection in comparison to carbon detection. These high-sensitivity experiments are especially important for membrane proteins, which often have rather low expression yield. Proton-detection based experiments are expected to play an important role in accelerating protein structure elucidation by solid-state NMR with the improved sensitivity and resolution.

  3. Patients' experiences towards the donation of their residual biological samples and the impact of these experiences on the type of consent given for secondary use: A systematic review.

    Science.gov (United States)

    Wai, Chan Tuck; Mackey, Sandra Jane; Hegney, Desley Gail

    Background Residual or leftover clinical tissues are valuable resources for biomedical research. There is on-going discussion about the methodological, legal, and ethical issues on the collection, storage and use of these tissues for future research. This systematic review will consider qualitative studies previously conducted, which report on patients' preferences, experiences and willingness to donate their tissues.Objectives The aim of this review was to critically appraise, synthesize and present the best available evidence related to the experiences of patients toward consent when donating their leftover tissue for research.Search strategy The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized. An initial limited search of MEDLINE and CINAHL was undertaken, followed by analysis of text words contained in the title and abstract, and of the index terms used to describe the article. A second search using all identified keywords and index terms was then undertaken across all included databases. Thirdly, the reference lists of all identified reports and articles were searched for additional studies.Data collection & analysis The standardised data extraction tool from the Joanna Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI) was used to extract data from each paper. The qualitative research findings were presented as thematic pooling using the JBI-QARI approach in a narrative form. During the analysis, 131 study findings from 18 publications were aggregated into 19 categories to form four synthesized findings.Main results The synthesized findings generated were: (1) Healthcare professionals should be aware that patients' consent to the use of their left-over tissues are influenced by many and varied factors. Primarily these factors included: benefits to self and other and trust in research and researchers; (2) Healthcare institutions and regulatory authorities must provide strict

  4. Proton radiography to improve proton therapy treatment

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

  5. Estratégias de amostragem para determinação do nitrato residual no solo após o cultivo do tomateiro adubado em sulcos = Sampling strategies for determining residual nitrate soil levels after growing tomatoes in fertilized furrows

    Directory of Open Access Journals (Sweden)

    Charles de Araújo

    2010-07-01

    Full Text Available O efeito de diferentes critérios para o manejo da adubação nitrogenada e do posicionamento de amostragem para a quantificação do N-NO3 residual no solo foi determinado após o cultivo do tomateiro adubado por sulcos. Dois experimentos foram conduzidos, no campo sem proteção, com aplicação de adubo sólido e irrigação por sulcos. Em cada experimento, os tratamentos foram arranjados em parcela subdivida, com dez critérios para o manejo da adubação nitrogenada na parcela e posições de amostragem do solo na subparcela. Esses foram arranjados no delineamento experimental de blocos ao acaso. Foi determinado o teor de N-NO3 no solo de amostras retiradas no final do ciclo de cada experimento, em diferentes posições. Em todos os experimentos o teor de N-NO3 residual no solo foi proporcional àquantidade de N aplicada nos diferentes critérios. Em condições de campo sem proteção e fertilizante nitrogenado aplicado em sulco, a melhor estratégia de amostragem do solo para a determinação do teor de N-NO3 residual foi obtida pela utilização de amostra composta tomada em posições sobre o sulco e entre o sulco e as plantas.Management of nitrogen fertilizer programs and sampling strategies to determine the levels of N-NO3 in the soil after growing tomatoes in fertilized furrows were studied. Two groups were studied, one without protection and another grown in an irrigated furrow in which a solid nitrogen fertilizer had been applied. In each plot, 10 treatments or criteria were evaluated. In each experiment, the treatments were arranged in a split-plot design, with 10 different nitrogen fertilizer conditions as the main treatment and soil sampling positions in a split-plot treatment. The sampling positions were arranged in a randomized complete block design. Soil N-NO3 levels were determined at the end of each sampling cycle. In all groups, residual soil N-NO3 levels were proportional to the amount of N applied. In fields without

  6. Solid residues

    International Nuclear Information System (INIS)

    Mulder, E.; Duin, P.J. van; Grootenboer, G.J.

    1995-01-01

    A summary is presented of the many investigations that have been done on solid residues of atmospheric fluid bed combustion (AFBC). These residues are bed ash, cyclone ash and bag filter ash. Physical and chemical properties are discussed and then the various uses of residues (in fillers, bricks, gravel, and for recovery of aluminium) are summarised. Toxicological properties of fly ash and stack ash are discussed as are risks of pneumoconiosis for workers handling fly ash, and contamination of water by ashes. On the basis of present information it is concluded that risks to public health from exposure to emissions of coal fly ash from AFBC appear small or negligible as are health risk to workers in the coal fly ash processing industry. 35 refs., 5 figs., 12 tabs

  7. Direct sampling of sub-µm atmospheric particulate organic matter in sub-ng m-3 mass concentrations by proton-transfer-reaction mass spectrometry

    Science.gov (United States)

    Armin, W.; Mueller, M.; Klinger, A.; Striednig, M.

    2017-12-01

    A quantitative characterization of the organic fraction of atmospheric particulate matter is still challenging. Herein we present the novel modular "Chemical Analysis of Aerosol Online" (CHARON) particle inlet system coupled to a new-generation proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF 6000 X2, Ionicon Analytik, Austria) that quantitatively detects organic analytes in real-time and sub-pptV levels by chemical ionization with hydronium reagent ions. CHARON consists of a gas-phase denuder for stripping off gas-phase analytes (efficiency > 99.999%), an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. With typical particle enrichment factors of around 30 for particle diameters (DP) between 120 nm and 1000 nm (somewhat reduced enrichment for 60 nm 6000) and excellent mass accuracies (< 10 ppm) chemical compositions can be assigned and included in further analyses. In addition to a detailed characterization of the CHARON PTR-TOF 6000 X2 we will present first results on the chemical composition of sub-µm particulate organic matter in the urban atmosphere in Innsbruck (Austria).

  8. The underlying event in proton-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, F.

    2009-05-15

    In this thesis, studies of the underlying event in proton-proton collisions at a center-of-mass energy of {radical}(s) = 10 TeV are presented. Crucial ingredient to underlying event models are multiple parton-parton scatters in single proton-proton collisions. The feasibility of measuring the underlying event was investigated with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) using charged particles and charged-particle jets. Systematic uncertainties of the underlying event measurement due to detector misalignment and imperfect track reconstruction are found to be negligible after {integral}Ldt=1 pb{sup -1} of data are available. Different model predictions are compared with each other using fully simulated Monte Carlo samples. It is found, that distinct models differ strongly enough to tell them apart with early data. (orig.)

  9. Proton diffraction

    International Nuclear Information System (INIS)

    Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.

    1998-01-01

    The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)

  10. Characterization of Hospital Residuals

    International Nuclear Information System (INIS)

    Blanco Meza, A.; Bonilla Jimenez, S.

    1997-01-01

    The main objective of this investigation is the characterization of the solid residuals. A description of the handling of the liquid and gassy waste generated in hospitals is also given, identifying the source where they originate. To achieve the proposed objective the work was divided in three stages: The first one was the planning and the coordination with each hospital center, in this way, to determine the schedule of gathering of the waste can be possible. In the second stage a fieldwork was made; it consisted in gathering the quantitative and qualitative information of the general state of the handling of residuals. In the third and last stage, the information previously obtained was organized to express the results as the production rate per day by bed, generation of solid residuals for sampled services, type of solid residuals and density of the same ones. With the obtained results, approaches are settled down to either determine design parameters for final disposition whether for incineration, trituration, sanitary filler or recycling of some materials, and storage politics of the solid residuals that allow to determine the gathering frequency. The study concludes that it is necessary to improve the conditions of the residuals handling in some aspects, to provide the cleaning personnel of the equipment for gathering disposition and of security, minimum to carry out this work efficiently, and to maintain a control of all the dangerous waste, like sharp or polluted materials. In this way, an appreciable reduction is guaranteed in the impact on the atmosphere. (Author) [es

  11. Selection bias in dynamically measured supermassive black hole samples: scaling relations and correlations between residuals in semi-analytic galaxy formation models

    Science.gov (United States)

    Barausse, Enrico; Shankar, Francesco; Bernardi, Mariangela; Dubois, Yohan; Sheth, Ravi K.

    2017-07-01

    Recent work has confirmed that the scaling relations between the masses of supermassive black holes and host-galaxy properties such as stellar masses and velocity dispersions may be biased high. Much of this may be caused by the requirement that the black hole sphere of influence must be resolved for the black hole mass to be reliably estimated. We revisit this issue with a comprehensive galaxy evolution semi-analytic model. Once tuned to reproduce the (mean) correlation of black hole mass with velocity dispersion, the model cannot account for the correlation with stellar mass. This is independent of the model's parameters, thus suggesting an internal inconsistency in the data. The predicted distributions, especially at the low-mass end, are also much broader than observed. However, if selection effects are included, the model's predictions tend to align with the observations. We also demonstrate that the correlations between the residuals of the scaling relations are more effective than the relations themselves at constraining models for the feedback of active galactic nuclei (AGNs). In fact, we find that our model, while in apparent broad agreement with the scaling relations when accounting for selection biases, yields very weak correlations between their residuals at fixed stellar mass, in stark contrast with observations. This problem persists when changing the AGN feedback strength, and is also present in the hydrodynamic cosmological simulation Horizon-AGN, which includes state-of-the-art treatments of AGN feedback. This suggests that current AGN feedback models are too weak or simply not capturing the effect of the black hole on the stellar velocity dispersion.

  12. Proton NMR-based metabolite analyses of archived serial paired serum and urine samples from myeloma patients at different stages of disease activity identifies acetylcarnitine as a novel marker of active disease.

    Directory of Open Access Journals (Sweden)

    Alessia Lodi

    Full Text Available BACKGROUND: Biomarker identification is becoming increasingly important for the development of personalized or stratified therapies. Metabolomics yields biomarkers indicative of phenotype that can be used to characterize transitions between health and disease, disease progression and therapeutic responses. The desire to reproducibly detect ever greater numbers of metabolites at ever diminishing levels has naturally nurtured advances in best practice for sample procurement, storage and analysis. Reciprocally, since many of the available extensive clinical archives were established prior to the metabolomics era and were not processed in such an 'ideal' fashion, considerable scepticism has arisen as to their value for metabolomic analysis. Here we have challenged that paradigm. METHODS: We performed proton nuclear magnetic resonance spectroscopy-based metabolomics on blood serum and urine samples from 32 patients representative of a total cohort of 1970 multiple myeloma patients entered into the United Kingdom Medical Research Council Myeloma IX trial. FINDINGS: Using serial paired blood and urine samples we detected metabolite profiles that associated with diagnosis, post-treatment remission and disease progression. These studies identified carnitine and acetylcarnitine as novel potential biomarkers of active disease both at diagnosis and relapse and as a mediator of disease associated pathologies. CONCLUSIONS: These findings show that samples conventionally processed and archived can provide useful metabolomic information that has important implications for understanding the biology of myeloma, discovering new therapies and identifying biomarkers potentially useful in deciding the choice and application of therapy.

  13. Proton imaging apparatus for proton therapy application

    International Nuclear Information System (INIS)

    Sipala, V.; Lo Presti, D.; Brianzi, M.; Civinini, C.; Bruzzi, M.; Scaringella, M.; Talamonti, C.; Bucciolini, M.; Cirrone, G.A.P.; Cuttone, G.; Randazzo, N.; Stancampiano, C.; Tesi, M.

    2011-01-01

    Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.

  14. Proton radioactivity from proton-rich nuclei

    International Nuclear Information System (INIS)

    Guzman, F.; Goncalves, M.; Tavares, O.A.P.; Duarte, S.B.; Garcia, F.; Rodriguez, O.

    1999-03-01

    Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)

  15. Determination of Pesticide Residues in Honeybees using Modified QUEChERS Sample Work-Up and Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Żaneta Bargańska

    2014-03-01

    Full Text Available Increasing emissions of chemical compounds to the environment, especially of pesticides, is one of factors that may explain present honeybee colony losses. In this work, an analytical method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS was optimized for the simultaneous screening of 19 pesticides which have not been yet determined in honeybee samples from northern Poland (Pomerania. The sample preparation, based on the QuEChERS method combining salting-out liquid-liquid extraction to acetonitrile and a dispersive-SPE clean-up, was adjusted to honeybee samples by adding a small amount of hexane to eliminate beeswax. The recovery of analytes ranged from 70% to 120% with relative standard deviation ≤20%. The limits of detection were in the range of 0.91–25 ng/g. A total of 19 samples of honeybees from suspected pesticide poisoning incidents were analyzed, in which 19 different pesticides were determined.

  16. MEASUREMENT OF PYRETHROID RESIDUES IN ENVIRONMENTAL AND FOOD SAMPLES BY ENHANCED SOLVENT EXTRACTION/SUPERCRITICAL FLUID EXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

    Science.gov (United States)

    The abstract summarizes pyrethorid methods development research. It provides a summary of sample preparation and analytical techniques such as supercritical fluid extraction, enhance solvent extraction, gas chromatography and tandem mass spectrometry.

  17. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  18. Rapid analysis of pesticide residues in drinking water samples by dispersive solid-phase extraction based on multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry.

    Science.gov (United States)

    Zou, Nan; Gu, Kejia; Liu, Shaowen; Hou, Yanbing; Zhang, Jialei; Xu, Xiang; Li, Xuesheng; Pan, Canping

    2016-03-01

    An analytical method based on dispersive solid-phase extraction with a multiwalled carbon nanotubes sorbent coupled with positive pulse glow discharge ion mobility spectrometry was developed for analysis of 30 pesticide residues in drinking water samples. Reduced ion mobilities and the mass-mobility correlation of 30 pesticides were measured. The pesticides were divided into five groups to verify the separation capability of pulse glow discharge in mobility spectrometry. The extraction conditions such as desorption solvent, ionic strength, conditions of adsorption and desorption, the amounts of multiwalled carbon nanotubes, and solution pH were optimized. The enrichment factors of pesticides were 5.4- to 48.7-fold (theoretical enrichment factor was 50-fold). The detection limits of pesticides were 0.01∼0.77 μg/kg. The linear range was 0.005-0.2 mg/L for pesticide standard solutions, with determination coefficients from 0.9616 to 0.9999. The method was applied for the analysis of practical and spiked drinking water samples. All results were confirmed by high-performance liquid chromatography with tandem mass spectrometry. The proposed method was proven to be a commendably rapid screening qualitative and semiquantitative technique for the analysis of pesticide residues in drinking water samples on site. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Proton tracking in a high-granularity Digital Tracking Calorimeter for proton CT purposes

    Science.gov (United States)

    Pettersen, H. E. S.; Alme, J.; Biegun, A.; van den Brink, A.; Chaar, M.; Fehlker, D.; Meric, I.; Odland, O. H.; Peitzmann, T.; Rocco, E.; Ullaland, K.; Wang, H.; Yang, S.; Zhang, C.; Röhrich, D.

    2017-07-01

    Radiation therapy with protons as of today utilizes information from x-ray CT in order to estimate the proton stopping power of the traversed tissue in a patient. The conversion from x-ray attenuation to proton stopping power in tissue introduces range uncertainties of the order of 2-3% of the range, uncertainties that are contributing to an increase of the necessary planning margins added to the target volume in a patient. Imaging methods and modalities, such as Dual Energy CT and proton CT, have come into consideration in the pursuit of obtaining an as good as possible estimate of the proton stopping power. In this study, a Digital Tracking Calorimeter is benchmarked for proof-of-concept for proton CT purposes. The Digital Tracking Calorimeter was originally designed for the reconstruction of high-energy electromagnetic showers for the ALICE-FoCal project. The presented prototype forms the basis for a proton CT system using a single technology for tracking and calorimetry. This advantage simplifies the setup and reduces the cost of a proton CT system assembly, and it is a unique feature of the Digital Tracking Calorimeter concept. Data from the AGORFIRM beamline at KVI-CART in Groningen in the Netherlands and Monte Carlo simulation results are used to in order to develop a tracking algorithm for the estimation of the residual ranges of a high number of concurrent proton tracks. High energy protons traversing the detector leave a track through the sensor layers. These tracks are spread out through charge diffusion processes. A charge diffusion model is applied for acquisition of estimates of the deposited energy of the protons in each sensor layer by using the size of the charge diffused area. A model fit of the Bragg Curve is applied to each reconstructed track and through this, estimating the residual range of each proton. The range of the individual protons can at present be estimated with a resolution of 4%. The readout system for this prototype is able to

  20. Proton tracking in a high-granularity Digital Tracking Calorimeter for proton CT purposes

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, H.E.S., E-mail: helge.pettersen@helse-bergen.no [Department of Oncology and Medical Physics, Haukeland University Hospital, Postbox 1400, 5021 Bergen (Norway); Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway); Alme, J. [Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway); Biegun, A. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747 AA Groningen (Netherlands); Brink, A. van den [Nikhef, Utrecht University, Postbox 41882, 1009 DB Amsterdam (Netherlands); Chaar, M.; Fehlker, D. [Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway); Meric, I. [Department of Electrical Engineering, Bergen University College, Postbox 7030, 5020 Bergen (Norway); Odland, O.H. [Department of Oncology and Medical Physics, Haukeland University Hospital, Postbox 1400, 5021 Bergen (Norway); Peitzmann, T.; Rocco, E. [Nikhef, Utrecht University, Postbox 41882, 1009 DB Amsterdam (Netherlands); Ullaland, K. [Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway); Wang, H. [Nikhef, Utrecht University, Postbox 41882, 1009 DB Amsterdam (Netherlands); Yang, S. [Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway); Zhang, C. [Nikhef, Utrecht University, Postbox 41882, 1009 DB Amsterdam (Netherlands); Röhrich, D. [Department of Physics and Technology, University of Bergen, Postbox 7803, 5020 Bergen (Norway)

    2017-07-11

    Radiation therapy with protons as of today utilizes information from x-ray CT in order to estimate the proton stopping power of the traversed tissue in a patient. The conversion from x-ray attenuation to proton stopping power in tissue introduces range uncertainties of the order of 2–3% of the range, uncertainties that are contributing to an increase of the necessary planning margins added to the target volume in a patient. Imaging methods and modalities, such as Dual Energy CT and proton CT, have come into consideration in the pursuit of obtaining an as good as possible estimate of the proton stopping power. In this study, a Digital Tracking Calorimeter is benchmarked for proof-of-concept for proton CT purposes. The Digital Tracking Calorimeter was originally designed for the reconstruction of high-energy electromagnetic showers for the ALICE-FoCal project. The presented prototype forms the basis for a proton CT system using a single technology for tracking and calorimetry. This advantage simplifies the setup and reduces the cost of a proton CT system assembly, and it is a unique feature of the Digital Tracking Calorimeter concept. Data from the AGORFIRM beamline at KVI-CART in Groningen in the Netherlands and Monte Carlo simulation results are used to in order to develop a tracking algorithm for the estimation of the residual ranges of a high number of concurrent proton tracks. High energy protons traversing the detector leave a track through the sensor layers. These tracks are spread out through charge diffusion processes. A charge diffusion model is applied for acquisition of estimates of the deposited energy of the protons in each sensor layer by using the size of the charge diffused area. A model fit of the Bragg Curve is applied to each reconstructed track and through this, estimating the residual range of each proton. The range of the individual protons can at present be estimated with a resolution of 4%. The readout system for this prototype is able to

  1. Cross section measurement of residues produced in proton- and deuteron-induced spallation reactions on 93Zr at 105 MeV/u using the inverse kinematics method

    Directory of Open Access Journals (Sweden)

    Kawase Shoichiro

    2017-01-01

    Full Text Available Isotopic production cross sections in the proton- and deuteron-induced spallation reactions on 93Zr at an energy of 105 MeV/u were measured in inverse kinematics conditions for the development of realistic nuclear transmutation processes for long-lived fission products (LLFPs with neutron and light-ion beams. The experimental results were compared to the PHITS calculations describing the intra-nuclear cascade and evaporation processes. Although an overall agreement was obtained, a large overestimation of the production cross sections for the removal of a few nucleons was seen. A clear shell effect associated with the neutron magic number N = 50 was observed in the measured isotopic production yields of Zr and Y isotopes, which can be reproduced reasonably by the PHITS calculation.

  2. Production cross sections of proton-induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sung-Chul; Song, Tae-Yung; Lee, Young-Ouk [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 41566 (Korea, Republic of)

    2017-05-01

    The production cross sections of residual radionuclides such as {sup 86,88,89g}Zr, {sup 86g,87m,87g,88}Y, {sup 83g,85g}Sr, and {sup 83,84g}Rb in the {sup 89}Y(p,x) reaction were measured using a stacked-foil activation and offline γ-ray spectrometric technique with proton energies of 57 MeV and 69 MeV at the 100 MeV proton linac in the Korea Multi-purpose Accelerator Complex (KOMAC), Gyeongju, Korea. The induced activities of the activated samples were measured using a high purity germanium (HPGe) detector, and the proton flux was determined using the {sup nat}Cu(p,x){sup 62}Zn reaction. The measured data was compared with other experimental data and the data from the TENLD-2015 library based on the TALYS code. The present results are generally lower than those in literature, but are found to be in agreement with the shape of the excitation functions. The integral yields for the thick target using the measured cross sections are given.

  3. QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices: a critical review.

    Science.gov (United States)

    Bruzzoniti, Maria Concetta; Checchini, Leonardo; De Carlo, Rosa Maria; Orlandini, Serena; Rivoira, Luca; Del Bubba, Massimo

    2014-07-01

    Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up technique originally developed for recovering pesticide residues from fruits and vegetables. Since its introduction, and until December 2013, about 700 papers have been published using the QuEChERS technique, according to a literature overview carried out using SciFinder, Elsevier SciVerse, and Google search engines. Most of these papers were dedicated to pesticide multiresidue analysis in food matrices, and this topic has been thoroughly reviewed over recent years. The QuEChERS approach is now rapidly developing beyond its original field of application to analytes other than pesticides, and matrices other than food, such as biological fluids and non-edible plants, including Chinese medicinal plants. Recently, the QuEChERS concept has spread to environmental applications by analyzing not only pesticides but also other compounds of environmental concern in soil, sediments, and water. To the best of our knowledge, QuEChERS environmental applications have not been reviewed so far; therefore, in this contribution, after a general discussion on the evolution and changes of the original QuEChERS method, a critical survey of the literature regarding environmental applications of conventional and modified QuEChERS methodology is provided. The overall recoveries obtained with QuEChERS and other extraction approaches (e.g., accelerated solvent extraction, ultrasonic solvent extraction, liquid/solid extraction, and soxhlet extraction) were compared, providing evidence for QuEChERS higher recoveries for various classes of compounds, such as biopesticides, chloroalkanes, phenols, and perfluoroalkyl substances. The role of physicochemical properties of soil (i.e., clay and organic carbon content, as well as cation exchange capacity) and target analytes (i.e., log KOW, water solubility, and vapor pressure) were also evaluated in order to interpret recovery and matrix effect data.

  4. Aerosol composition studies using accelerator proton bombardment

    International Nuclear Information System (INIS)

    Nelson, J.W.; Winchester, J.W.; Akselsson, R.

    1974-01-01

    The proton beam of the Florida State University Tandem Van de Graaff Accelerator is being used to make quantitative determinations of the composition of particulate matter found in the atmosphere. Proton scattering using 16 MeV incident particle energy is employed to resolve the light elements (up to Cl), while elements Al and heavier are observed via proton induced x-ray emission analysis. In order to realize advantages of these proton excited analyses, specialized techniques are used, such as the use of uniform beams which entirely cover the area of targets of nonuniform areal density. Also, specialized air sampling equipment was built to take advantage of the small size of samples required for proton-induced analyses. The multielement character, ease of automation, and short time (several minutes) needed for analysis make these techniques attractive from the standpoint of analysis cost per sample

  5. Expected proton signal sizes in the PRaVDA Range Telescope for proton Computed Tomography

    International Nuclear Information System (INIS)

    Price, T.; Parker, D.J.; Green, S.; Esposito, M.; Waltham, C.; Allinson, N.M.; Poludniowski, G.; Evans, P.; Taylor, J.; Manolopoulos, S.; Anaxagoras, T.; Nieto-Camero, J.

    2015-01-01

    Proton radiotherapy has demonstrated benefits in the treatment of certain cancers. Accurate measurements of the proton stopping powers in body tissues are required in order to fully optimise the delivery of such treaments. The PRaVDA Consortium is developing a novel, fully solid state device to measure these stopping powers. The PRaVDA Range Telescope (RT), uses a stack of 24 CMOS Active Pixel Sensors (APS) to measure the residual proton energy after the patient. We present here the ability of the CMOS sensors to detect changes in the signal sizes as the proton traverses the RT, compare the results with theory, and discuss the implications of these results on the reconstruction of proton tracks

  6. Sample-scale zircon geochemical and geochronological heterogeneities as indicators of residual liquid infiltration events in the incrementally assembled Caleu Pluton, Central Chile

    Science.gov (United States)

    Molina, P. G.; Parada, M. A.; Gutiérrez, F. J.; Ma, C.; Li, J.; Liu, Y.

    2013-12-01

    The Upper Cretaceous metaluminous Caleu Pluton is emplaced at a depth equivalent of 2kbar and consists of four lithological zones: the Gabbro-Dioritic Zone (GDZ), the Quartz-Monzodioritic Zone (QMDZ), the Granodioritic Zone (GZ) and the Monzogranitic Zone (MGZ). The zones would have been fed from a deeper magma reservoir emplaced at a 4 kbar. U238/Pb206 LA-ICP-MS geochronology of zircon grains of the four lithological zones (82 analyzed spots, 4 samples) indicates a maximum zircon crystallization range of ca. 106-91 Ma for the pluton as a whole. The U-Pb zircon age distribution of the four samples shows three inflection points at about 101, 99 and 96 Ma, separating four zircon crystallization events with the following weighted average ages and 2σ confidence intervals: 103.×1.6 Ma (n=4), 100.3×0.68 Ma (n=14), 97.49×0.49 Ma (n=25) and 94.66×0.44 Ma (n=30). The GDZ sample records the first three events, the GZ and QMDZ samples record the last three events while the MGZ only have zircons formed during the last two events. It is interesting to note that the youngest event of zircon formation coincide with the Ar/Ar cooling ages (95-93 Ma) previously obtained in hornblende, biotite and plagioclase of the four lithological zones, as a consequence of a rapid pluton exhumation. Temperatures of zircon crystallization (Ti-in-Zrn) obtained in each sample are variable and roughly lower than the zircon saturation temperatures. Most of the Ti-in-Zrn temperatures indicate late-stage crystallization conditions, consistent with the calculated melt composition from which zircons would have crystallized and the observed coexistence of zircons with quartz-orthoclase symplectites, hornblende and interstitial anhedral biotite. There are variable and overlapped total incompatible element concentrations in zircons of the four lithological zones regardless its age and Ti-in-Zrn temperatures, indicating that the melts from which zircon crystallized at different moments, were equivalent

  7. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    Khan, Rashiduzzman

    1976-09-01

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  8. Proton movies

    CERN Multimedia

    2009-01-01

    A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...

  9. Development and validation of a solid-phase extraction method coupled to liquid chromatography with fluorescence detection for the determination of fluoroquinolone residues in powdered infant formulae. Application to the analysis of samples from the Spanish and Latin American market.

    Science.gov (United States)

    Rodriguez, E; Moreno-Bondi, M C; Marazuela, M D

    2008-10-31

    This paper describes a new method for the effective extraction, clean-up and chromatographic analysis of residues of four fluoroquinolones (ciprofloxacin, enrofloxacin, danofloxacin and sarafloxacin) in powdered infant formulae and follow-on preparations. Samples were reconstituted following the manufacturer's recommendations and treated with trichloroacetic acid in methanol 10% (w/v) for deproteinization. Two solid-phase extraction cartridges have been evaluated for sample clean-up and preconcentration, Strata Screen A and Strata X and the later provided the best recoveries for all the analytes tested. Chromatographic analysis has been carried out using a polar endcapped column (AQUA C(18)) and fluorescence detection, with lomefloxacin (LOME) as internal standard. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC(alpha)) and detection capability (CC(beta)). Typical recoveries ranged between 70 and 110% at levels below and above the maximum residue limits of the target analytes in bovine milk, with an excellent intralab reproducibility (RSDsmarket, using LC-MS/MS as confirmatory technique.

  10. Application of dispersive Liquid-Liquid microextraction based on solidification of floating organic droplet multi-residue method for the simultaneous determination of polychlorinated biphenyls, organochlorine, and pyrethroid pesticides in aqueous sample

    International Nuclear Information System (INIS)

    Zuo, Mei; Li, Man-Liang; Cheng, Jing; Matsadiq, Guzalnur; Liu, Lu; Zhang, Miao

    2012-01-01

    Dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) technique was successfully applied for simultaneous assay of eight polychlorinated biphenyls, two organochlorine, and four pyrethroid pesticides multi-residue in aqueous samples by using GC-electron capture detection. The effects of various parameters such as kind of extractant and dispersant and volume of them, extraction time, effect of salt addition, and pH were optimized. As a result, 5.0 μL 1-dodecanol was chosen as extraction solvent, 600 μL methanol were used as dispersive solvent without salt addition, pH was adjusted to 7. Under the optimized conditions, the limits of detection (LOD) were ranged from 1.4 to 8.3 ng L -1 . Satisfactory linear range was observed from 5.0 to 2000 ng L -1 with correlation coefficient better than 0.9909. Good precisions were also acquired with RSD better than 13.6% for all target analytes. The enrichment factors of the method were ranged from 786 to 1427. The method can be successfully applied to simultaneous separation and determination of three class residues in real water samples and good recoveries were obtained ranging from 76 to 130, 73 to 129, and 78 to 130% for tap water, lake water, and industrial waste water, respectively. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Rapid monitoring of residual UV-stabilizers in seawater samples from beaches using fabric phase sorptive extraction and UHPLC-MS/MS.

    Science.gov (United States)

    García-Guerra, Romualdo B; Montesdeoca-Esponda, Sarah; Sosa-Ferrera, Zoraida; Kabir, Abuzar; Furton, Kenneth G; Santana-Rodríguez, José Juan

    2016-12-01

    Benzotriazole UV stabilizers (BUVSs) are a group of compounds added to personal care products such as sunscreens, hair dyes, make up formulations, soaps or shampoos, among others. Direct input from beaches or another aquatic recreational areas is the main source of BUVSs incorporation to the environment, where they can be mutagenic, toxic, pseudo-persistent and bioaccumulative. Due to the low levels of concentration of these compounds found in environmental samples, an extraction process is required prior to their determination. Fabric phase sorptive extraction integrates the advanced material properties of sol-gel hybrid inorganic-organic sorbents with flexible, permeable and functionally active fabric substrates, being a highly responsive, efficient and cheap device that also can be reused. In this paper, we applied fabric phase sorptive extraction methodology to analyse six BUVSs in twenty-four seawater samples from different coastal areas of Gran Canaria Island (Spain). It was coupled to ultra high performance liquid chromatography with tandem mass spectrometry in order to achieve a fast, reliable and sensitive separation and determination of the analytes from different simple matrices, regardless of its complexity and composition. Under the optimum conditions, the proposed method provided enrichment factors of 25 times with limits of detection from 1.06 to 8.96 ng L -1 and limits of quantification from 3.54 to 29.9 ng L -1 for the analytes under study in spiked samples. Intra and inter-day relative standard deviations were between 3.97 and 20.8% for all compounds. The application of the optimized methodology to non-spiked seawater samples allows detecting and quantifying the UV 360 in the range from 41.12 to 544.9 ng L -1 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Ultra-high performance liquid chromatography with fluorescence detection following salting-out assisted liquid-liquid extraction for the analysis of benzimidazole residues in farm fish samples.

    Science.gov (United States)

    Tejada-Casado, Carmen; Lara, Francisco J; García-Campaña, Ana M; Del Olmo-Iruela, Monsalud

    2018-03-30

    Ultra-high performance liquid chromatography (UHPLC) coupled with fluorescence detection (FL) has been proposed for the first time to determine thirteen benzimidazoles (BZs) in farmed fish samples. In order to optimize the chromatographic separation, parameters such as mobile phase composition and flow rate were carefully studied, establishing a gradient mode with a mobile phase consisted of water (solvent A) and acetonitrile (solvent B) at a flow rate of 0.4 mL/min. The separation was performed on a Zorbax Eclipse Plus RRHD C 18 column (50 × 2.1 mm, 1.8 μm), involving a total analysis time lower than 12 min. Salting-out assisted liquid-liquid extraction (SALLE) was applied as sample treatment to different types of farmed fish (trout, sea bream and sea bass). To obtain satisfactory extraction efficiencies for the studied analytes, several parameters affecting the SALLE procedure were optimized including the amount of sample, type and volume of the extraction solvent, and the nature and amount of the salt used. Characterization of the method in terms of performance characteristics was carried out, obtaining satisfactory results for the linearity (R 2  ≥ 0.997), repeatability (RSD ≤ 6.1%), reproducibility (RSD ≤ 10.8%) and recoveries (R ≥ 79%; RSD ≤ 7.8%). Detection limits between 0.04-29.9 μg kg -1 were obtained, demonstrating the applicability of this fast, simple and environmentally friendly method. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Nuclear structure at the proton dripline

    International Nuclear Information System (INIS)

    Maglione, Enrico; Ferreira, Lidia S.; Costa Lopes, Miguel

    2007-01-01

    Recent studies with exotic nuclei far from the stability region, lead to the discovery of one and two proton radioactivity, from ground state of spherical, as well as deformed nuclei. Isomeric decay and fine structure were also measured, and in some cases, a prompt proton and alpha particle emission was observed. It was established that, the majority of prompt particle decays proceeds from superdeformed initial states, into spherical daughter states, revealing a change of deformation during the decay. Proton radioactivity has been the unique way to probe nuclear structure mechanisms in this region of stability. Since proton emitters lie beyond the proton drip-line, they also give the possibility of observing Nilsson resonances. In fact, the experimental data on proton radioactivity in regionswhere theoretical models predict a certain deformation for the nucleus is consistent with the idea that the proton was in a single particle resonance state, in the field of the daughter nucleus. An important aspect of such calculations is the inclusion of the nuclear structure properties of the core,like the rotational spectrum of the daughter nucleus, and the pairing residual interaction. We will address various questions concerning what we have learned from the data and how far our theoretical models have taken us in the region of neutron deficient nuclei at the borders of stability. (Author)

  14. Data acquisition system for a proton imaging apparatus

    CERN Document Server

    Sipala, V; Bruzzi, M; Bucciolini, M; Candiano, G; Capineri, L; Cirrone, G A P; Civinini, C; Cuttone, G; Lo Presti, D; Marrazzo, L; Mazzaglia, E; Menichelli, D; Randazzo, N; Talamonti, C; Tesi, M; Valentini, S

    2009-01-01

    New developments in the proton-therapy field for cancer treatments, leaded Italian physics researchers to realize a proton imaging apparatus consisting of a silicon microstrip tracker to reconstruct the proton trajectories and a calorimeter to measure their residual energy. For clinical requirements, the detectors used and the data acquisition system should be able to sustain about 1 MHz proton rate. The tracker read-out, using an ASICs developed by the collaboration, acquires the signals detector and sends data in parallel to an FPGA. The YAG:Ce calorimeter generates also the global trigger. The data acquisition system and the results obtained in the calibration phase are presented and discussed.

  15. Determination of residual nonsteroidal anti-inflammatory drugs in aqueous sample using magnetic nanoparticles modified with cetyltrimethylammonium bromide by high performance liquid chromatography.

    Science.gov (United States)

    Khoeini Sharifabadi, Malihe; Saber-Tehrani, Mohammad; Waqif Husain, Syed; Mehdinia, Ali; Aberoomand-Azar, Parviz

    2014-01-01

    A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe3O4 magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface of MNPs was modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98-9.83% (n = 6) for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity (R (2) > 0.99) and the limit of detection (LODs) ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

  16. Multi-residue analysis method for analysis of pharmaceuticals using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS) in water sample

    Science.gov (United States)

    Al-Qaim, Fouad Fadhil; Abdullah, Md Pauzi; Othman, Mohamed Rozali

    2013-11-01

    In this work, a developed method using solid - phase extraction (SPE) followed by liquid chromatography - time of flight mass spectrometry (LC-ESI-TOF/MS) was developed and validated for quantification and confirmation of eleven pharmaceuticals with different therapeutic classes in water samples, Malaysia. These compounds are caffeine (CAF), prazosin (PRZ), enalapril (ENL), carbamazepine (CBZ), nifedipine (NFD), levonorgestrel (LNG), simvastatin (SMV), hydrochlorothiazide (HYD), gliclazide (GLIC), diclofenac-Na (DIC-Na) and mefenamic acid (MEF). LC was performed on a Dionex Ultimate 3000/LC 09115047 (USA) system. Chromatography was performed on a Thermo Scientific C18 (250 mm × 2.1 mm, i.d.: 5μm) column. Several parameters were optimised such as; mobile phase, gradient elution, collision energy and solvent elution for extraction of compounds from water. The recoveries obtained ranged from 30-148 % in river water. Five pharmaceutical compounds were detected in the surface water samples: caffeine, prazosin, enalpril, diclofenac-Na and mefenamic acid. The developed method is precise and accepted recoveries were got. In addition, this method is suitable to identify and quantify trace concentrations of pharmaceuticals in surface water.

  17. Sparse-view proton computed tomography using modulated proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiseoc; Kim, Changhwan; Cho, Seungryong, E-mail: scho@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejon 305-701 (Korea, Republic of); Min, Byungjun [Department of Radiation Oncology, Kangbuk Samsung Hospital, 110–746 (Korea, Republic of); Kwak, Jungwon [Department of Radiation Oncology, Asan Medical Center, 138–736 (Korea, Republic of); Park, Seyjoon; Lee, Se Byeong [Proton Therapy Center, National Cancer Center, 410–769 (Korea, Republic of); Park, Sungyong [Proton Therapy Center, McLaren Cancer Institute, Flint, Michigan 48532 (United States)

    2015-02-15

    Purpose: Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Methods: Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method–projection onto convex sets (SM-POCS), superiorization method–expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Results: Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed

  18. Proton-air and proton-proton cross sections

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2013-06-01

    Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

  19. Determination of Residual Nonsteroidal Anti-Inflammatory Drugs in Aqueous Sample Using Magnetic Nanoparticles Modified with Cetyltrimethylammonium Bromide by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Malihe Khoeini Sharifabadi

    2014-01-01

    Full Text Available A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen using Fe3O4 magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface of MNPs was modified with cetyltrimethylammonium bromide (CTAB as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02 acetonitrile (65 : 35 v/v as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD% of the method was investigated at three concentrations (25, 50, and 200 ng/mL and was in the range of 3.98–9.83% (n=6 for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity (R2>0.99 and the limit of detection (LODs ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

  20. Solid-phase extraction combined with dispersive liquid-liquid microextraction and chiral liquid chromatography-tandem mass spectrometry for the simultaneous enantioselective determination of representative proton-pump inhibitors in water samples.

    Science.gov (United States)

    Zhao, Pengfei; Deng, Miaoduo; Huang, Peiting; Yu, Jia; Guo, Xingjie; Zhao, Longshan

    2016-09-01

    This report describes, for the first time, the simultaneous enantioselective determination of proton-pump inhibitors (PPIs-omeprazole, lansoprazole, pantoprazole, and rabeprazole) in environmental water matrices based on solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME) and chiral liquid chromatography-tandem mass spectrometry. The optimized results of SPE-DLLME were obtained with PEP-2 column using methanol-acetonitrile (1/1, v/v) as elution solvent, dichloroethane, and acetonitrile as extractant and disperser solvent, respectively. The separation and determination were performed using reversed-phase chromatography on a cellulose chiral stationary phase, a Chiralpak IC (250 mm × 4.6 mm, 5 μm) column, under isocratic conditions at 0.6 mL min(-1) flow rate. The analytes were detected in multiple reaction monitoring (MRM) mode by triple quadrupole mass spectrometry. Isotopically labeled internal standards were used to compensate matrix interferences. The method provided enrichment factors of around 500. Under optimal conditions, the mean recoveries for all eight enantiomers from the water samples were 89.3-107.3 % with 0.9-10.3 % intra-day RSD and 2.3-8.1 % inter-day RSD at 20 and 100 ng L(-1) levels. Correlation coefficients (r (2)) ≥ 0.999 were achieved for all enantiomers within the range of 2-500 μg L(-1). The method detection and quantification limits were at very low levels, within the range of 0.67-2.29 ng L(-1) and 2.54-8.68 ng L(-1), respectively. This method was successfully applied to the determination of the concentrations and enantiomeric fractions of the targeted analytes in wastewater and river water, making it applicable to the assessment of the enantiomeric fate of PPIs in the environment. Graphical Abstract Simultaneous enantioselective determination of representative proton-pump inhibitors in water samples.

  1. Inexpensive, effective novel activated carbon fibers for sample cleanup: application to multipesticide residue analysis in food commodities using a QuEChERS method.

    Science.gov (United States)

    Singh, Shiv; Srivastava, Anshuman; Singh, Sheelendra Pratap

    2018-03-01

    Phenolic resin based activated carbon fibers (ACFs) were applied for the first time as a reversed-dispersive solid-phase extraction (r-DSPE) sorbent. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was applied to determine 26 pesticides (organophosphates, organochlorines, synthetic pyrethroids, and herbicides) in different complex matrices, including cauliflower, cucumber, banana, apple, wheat, and black gram. Different physicochemical characterization techniques were used to investigate the engineering and structural properties of the r-DSPE sorbent. All the chromatographic analyses were performed with a gas chromatograph equipped with an electron capture detector. The recoveries of all 26 pesticides were acceptable (70-120%), with relative standard deviations of less than 15%. The limit of detection and the limit of quantification were 1.13-5.48 ng/g and 3.42-16.60 ng/g, respectively. In the original QuEChERS method, primary secondary amine is extensively used as the r-DSPE sorbent in the cleanup process, but it is eightfold more expensive than the ACFs used in this study. Therefore, the modified QuEChERS method using ACFs during the cleanup process is more efficient, cheaper, and more robust to determine pesticides from different types of matrices, including vegetables, grains, and fruits, and ACFs could be used as a cost-effective alternative to primary secondary amine. Graphical Abstract Sample clean-up using PSA and ACF as r-DSPE sorbent in QuEChERS method.

  2. Molecular mechanisms controlling proton pumping by bacteriorhodopsin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, Rosalie K.; Ebrey, Thomas G.

    2000-02-10

    Bacteriorhodopsin (bR) is the simplest biological system for the transduction of light energy. Light energy is directly converted to transmembrane proton gradient by a single, small membrane protein. The extraordinary stability of bR makes it an outstanding subject for bioenergetic studies. This project has focused on the role of interactions between key residues of the pigment involved in light-induced proton transfer. Methods to estimate the strength of these interactions and their correlation with the rate and efficiency of proton transfer have been developed. The concept of the coupling of the protonation states of key groups has been applied to individual steps of the proton transfer with the ultimate goal of understanding on the molecular level the driving forces for proton transport and the pathway of the transported proton in bT. The mechanism of light-induced proton release, uptake and the mechanism of recovery of initial state of bT has been examined. The experiments were performed with genetically engineered, site-specific mutants of bR. This has enabled us to characterize the role of individual amino acid residues in bR. Time resolved and low temperature absorption spectroscopy and light-induced photocurrent measurements were used in order to study the photochemical cycle and proton transfer in mutant pigments. Chemical modification and crosslinking of both the specific amino acids to the chromophore or to other amino acids were used to elucidate the role of light-induced conformational changes in the photocycle and the structure of the protein in the ground state. The results of this project provided new knowledge on the architecture of the proton transfer pathways inside the protein, on the mechanism of proton release in bR, and on the role of specific amino acid residues in the structure and function of bR.

  3. Residual nilpotence and residual solubility of groups

    International Nuclear Information System (INIS)

    Mikhailov, R V

    2005-01-01

    The properties of the residual nilpotence and the residual solubility of groups are studied. The main objects under investigation are the class of residually nilpotent groups such that each central extension of these groups is also residually nilpotent and the class of residually soluble groups such that each Abelian extension of these groups is residually soluble. Various examples of groups not belonging to these classes are constructed by homological methods and methods of the theory of modules over group rings. Several applications of the theory under consideration are presented and problems concerning the residual nilpotence of one-relator groups are considered.

  4. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  5. Neutron residual stress measurements in linepipe

    International Nuclear Information System (INIS)

    Law, Michael; Gnaepel-Herold, Thomas; Luzin, Vladimir; Bowie, Graham

    2006-01-01

    Residual stresses in gas pipelines are generated by manufacturing and construction processes and may affect the subsequent pipe integrity. In the present work, the residual stresses in eight samples of linepipe were measured by neutron diffraction. Residual stresses changed with some coating processes. This has special implications in understanding and mitigating stress corrosion cracking, a major safety and economic problem in some gas pipelines

  6. Benchmarking residual dose rates in a NuMI-like environment

    Energy Technology Data Exchange (ETDEWEB)

    Igor L. Rakhno et al.

    2001-11-02

    Activation of various structural and shielding materials is an important issue for many applications. A model developed recently to calculate residual activity of arbitrary composite materials for arbitrary irradiation and cooling times is presented in the paper. Measurements have been performed at the Fermi National Accelerator Laboratory using a 120 GeV proton beam to study induced radioactivation of materials used for beam line components and shielding. The calculated residual dose rates for the samples studied behind the target and outside of the thick shielding are presented and compared with the measured ones. Effects of energy spectra, sample material and dimensions, their distance from the shielding, and gaps between the shielding modules and walls as well as between the modules themselves were studied in detail.

  7. Restrained Proton Indicator in Combined Quantum-Mechanics/Molecular-Mechanics Dynamics Simulations of Proton Transfer through a Carbon Nanotube.

    Science.gov (United States)

    Duster, Adam W; Lin, Hai

    2017-09-14

    Recently, a collective variable "proton indicator" was purposed for tracking an excess proton solvated in bulk water in molecular dynamics simulations. In this work, we demonstrate the feasibility of utilizing the position of this proton indicator as a reaction coordinate to model an excess proton migrating through a hydrophobic carbon nanotube in combined quantum-mechanics/molecular-mechanics simulations. Our results indicate that applying a harmonic restraint to the proton indicator in the bulk solvent near the nanotube pore entrance leads to the recruitment of water molecules into the pore. This is consistent with an earlier study that employed a multistate empirical valence bond potential and a different representation (center of excess charge) of the proton. We attribute this water recruitment to the delocalized nature of the solvated proton, which prefers to be in high-dielectric bulk solvent. While water recruitment into the pore is considered an artifact in the present simulations (because of the artificially imposed restraint on the proton), if the proton were naturally restrained, it could assist in building water wires prior to proton transfer through the pore. The potential of mean force for a proton translocation through the water-filled pore was computed by umbrella sampling, where the bias potentials were applied to the proton indicator. The free energy curve and barrier heights agree reasonably with those in the literature. The results suggest that the proton indicator can be used as a reaction coordinate in simulations of proton transport in confined environments.

  8. Elastic proton-proton scattering at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  9. Baryon production in proton-proton collisions

    International Nuclear Information System (INIS)

    Liu, F.M.; Werner, K.

    2002-01-01

    Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions

  10. Sol-gel-graphene-based fabric-phase sorptive extraction for cow and human breast milk sample cleanup for screening bisphenol A and residual dental restorative material before analysis by HPLC with diode array detection.

    Science.gov (United States)

    Samanidou, Victoria; Filippou, Olga; Marinou, Eirini; Kabir, Abuzar; Furton, Kenneth G

    2017-06-01

    Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Proton: the particle.

    Science.gov (United States)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

  12. Proton: The Particle

    Energy Technology Data Exchange (ETDEWEB)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  13. Proton-proton, anti-proton-anti-proton, proton-anti-proton correlations in Au+Au collisions measured by STAR at RHIC

    International Nuclear Information System (INIS)

    Gos, H.P.

    2007-01-01

    The analysis of two-particle correlations provides a powerful tool to study the properties of hot and dense matter created in heavy-ion collisions at ultra-relativistic energies. Applied to identical and non-identical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing complete information about the source characteristics. In this paper we present the correlation functions obtained for identical and non-identical baryon pairs of protons and anti-protons. The data were collected recently in Au+Au collisions at √(s NN )=62 GeV and √(s NN )=200 GeV by the STAR detector at the RHIC accelerator. We introduce corrections to the baryon-baryon correlations taking into account: residual correlations from weak decays, particle identification probability and the fraction of primary baryons. Finally we compare our results to theoretical predictions. (orig.)

  14. Studying the destruction of various fluoropolymers caused by gamma - irradiation and MeV protons

    International Nuclear Information System (INIS)

    Allayarov, S.R.; Ol'khov, Yu.A.; Gordon, D.A.; Muntele, C.I.; Muntele, I.C.; Ila, D.; Dixon, D.A.; Kispert, L.D.; Nikolskij, V.G.

    2007-01-01

    While fluoropolymers are normally used as anti-adherent coating, they are intensely investigated for potential use in various radiation dosimeter applications as well as space technology. In order to understand the discrepancy between high chemical and thermal stability and low radiation stability of various fluoropolymers, we are bombarding them with 1 MeV protons to fluences up to 2·10 15 protons/cm 2 as well as subjected some of them to gamma-irradiation by dose of 10 kGy. During bombardment we are monitoring the emission of chemical species with a residual gas analyzer. Gamma-irradiated samples were tested by radio thermoluminescence method. The results we present here are a good indicator that material damage happens much earlier than 2·10 15 protons/cm 2 and that further work should be addressed at much smaller exposures. Radio thermoluminescence also can be used at small doses of irradiation (10-30 kGy). The thermomechanical curve of radiation-free polyvinyledenefluoride (PVDF) is characteristic for topologically di-block amorphous polymer of quasi-crossing structure. In the temperature range of from 173 K up to 228 K polymer is vitrified. The vitrification temperature of PVDF is 228 K. All molecular-relaxation and quantitative characteristics of PVDF were determined before and after its irradiation by protons. Protons caused significant changes in PVDF. From di-block amorphous it transformed in to amorphous-crystalline structure. An appreciable influence of dose at proton irradiation of polymer was revealed both on topological level and on molecular-relaxation one. (authors)

  15. Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Balek, Petr; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Bremer, Johan; Brendlinger, Kurt; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brown, Gareth; Brown, Heather; Bruce, Roderik; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bundock, Aaron Colin; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Ilektra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Cole, Stephen; Colijn, Auke-Pieter; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Dassoulas, James; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lorenzi, Francesco; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dinut, Florin; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobos, Daniel; Dobson, Ellie; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dotti, Andrea; Dova, Maria-Teresa; Doxiadis, Alexander; Doyle, Tony; Dressnandt, Nandor; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Duguid, Liam; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edson, William; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fonseca Martin, Teresa; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fowler, Andrew; Fox, Harald; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilchriese, Murdock; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramstad, Eirik; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guest, Daniel; Guicheney, Christophe; Guido, Elisa; Guindon, Stefan; Gul, Umar; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Hong, Tae Min; Hooft van Huysduynen, Loek; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Jantsch, Andreas; Janus, Michel; Jared, Richard; Jarlskog, Göran; Jeanty, Laura; Jen-La Plante, Imai; Jennens, David; Jenni, Peter; Loevschall-Jensen, Ask Emil; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Joram, Christian; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karakostas, Konstantinos; Karnevskiy, Mikhail; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Kekelidze, George; Keller, John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kreiss, Sven; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Mark; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lambourne, Luke; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larner, Aimee; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Lepold, Florian; Leroy, Claude; Lessard, Jean-Raphael; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Lulu; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, XinChou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lukas, Wolfgang; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundberg, Olof; Lundquist, Johan; Lungwitz, Matthias; Lynn, David; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Mackeprang, Rasmus; Madaras, Ronald; Maddocks, Harvey Jonathan; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marroquim, Fernando; Marshall, Zach; Martens, Kalen; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzaferro, Luca; Mazzanti, Marcello; Mc Donald, Jeffrey; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meehan, Samuel; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Moles-Valls, Regina; Molfetas, Angelos; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Paredes Hernandez, Daniela; Park, Woochun; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pashapour, Shabnaz; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Lopez, Sebastian; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pinto, Belmiro; Pizio, Caterina; Plamondon, Mathieu; Pleier, Marc-Andre; Plotnikova, Elena; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radeka, Veljko; Radescu, Voica; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Roe, Adam; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rumyantsev, Leonid; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruzicka, Pavel; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarrazin, Bjorn; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schäfer, Uli; Schaelicke, Andreas; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schneider, Basil; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Sciolla, Gabriella; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snyder, Scott; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Staude, Arnold; Stavina, Pavel; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valentinetti, Sara; Valero, Alberto; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vazquez Schroeder, Tamara; Vegni, Guido; Veillet, Jean-Jacques; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wahrmund, Sebastian; Wakabayashi, Jun; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Rui; Wang, Song-Ming; Wang, Tan; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Michele; Weber, Pavel; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Wetter, Jeffrey; Weydert, Carole; Whalen, Kathleen; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xu, Chao; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Liwen; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zinonos, Zinonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zibell, Andre; Zieminska, Daria; Zimin, Nikolai; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2013-07-17

    This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstra...

  16. Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

    International Nuclear Information System (INIS)

    Poludniowski, G; Esposito, M; Evans, P M; Allinson, N M; Anaxagoras, T; Green, S; Parker, D J; Price, T; Manolopoulos, S; Nieto-Camero, J

    2014-01-01

    Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed. (paper)

  17. Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology.

    Science.gov (United States)

    Poludniowski, G; Allinson, N M; Anaxagoras, T; Esposito, M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Price, T; Evans, P M

    2014-06-07

    Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed.

  18. Electron clearing for the ISA proton beam

    International Nuclear Information System (INIS)

    Herrera, J.C.

    1976-01-01

    The circulating protons in the ISABELLE intersecting storage ring accelerator will collide with the residual gas in the vacuum chamber. The electrons produced will tend to be captured by the potential well of the beam itself and result in a neutralization of the space charge of the beam. A detailed analysis is given of the various mechanisms which can be used to reduce the net degree of beam neutralization. It is concluded that the average neutralization will be about 10 -4 for a residual gas pressure of 3 x 10 -11 torr of hydrogen

  19. Matrix Effect Evaluation and Method Validation of Azoxystrobin and Difenoconazole Residues in Red Flesh Dragon Fruit (Hylocereus polyrhizus) Matrices Using QuEChERS Sample Preparation Methods Followed by LC-MS/MS Determination.

    Science.gov (United States)

    Noegrohati, Sri; Hernadi, Elan; Asviastuti, Syanti

    2018-03-30

    Production of red flesh dragon fruit (Hylocereus polyrhizus) was hampered by Colletotrichum sp. Pre-harvest application of azoxystrobin and difenoconazole mixture is recommended, therefore, a selective and sensitive multi residues analytical method is required in monitoring and evaluating the commodity's safety. LC-MS/MS is a well-established analytical technique for qualitative and quantitative determination in complex matrices. However, this method is hurdled by co-eluted coextractives interferences. This work evaluated the pH effect of acetate buffered and citrate buffered QuEChERS sample preparation in their effectiveness of matrix effect reduction. Citrate buffered QuEChERS proved to produce clean final extract with relative matrix effect 0.4%-0.7%. Method validation of the selected sample preparation followed by LC-MS/MS for whole dragon fruit, flesh and peel matrices fortified at 0.005, 0.01, 0.1 and 1 g/g showed recoveries 75%-119%, intermediate repeatability 2%-14%. The expanded uncertainties were 7%-48%. Based on the international acceptance criteria, this method is valid.

  20. Trace determination of five triazole fungicide residues in traditional Chinese medicine samples by dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction and UHPLC-MS/MS.

    Science.gov (United States)

    Ma, Shuping; Yuan, Xucan; Zhao, Pengfei; Sun, Hong; Ye, Xiu; Liang, Ning; Zhao, Longshan

    2017-08-01

    A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol, and hexaconazol) in traditional Chinese medicine samples was developed using dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction before ultra-high performance liquid chromatography with tandem mass spectrometry. The clean up of the extract was conducted using dispersive solid-phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation. After that, a mixture of 400 μL trichloromethane (extraction solvent) and 0.5 mL of the above supernatant was injected rapidly into water for the dispersive liquid-liquid microextraction procedure. The factors affecting the extraction efficiency were optimized. Under the optimum conditions, the calibration curves showed good linearity in the range of 2.0-400 (tebuconazole, diniconazole, and hexaconazole) and 4.0-800 ng/g (triadimenol and flutriafol) with the regression coefficients higher than 0.9958. The limit of detection and limit of quantification for the present method were 0.5-1.1 and 1.8-4.0 ng/g, respectively. The recoveries of the target analytes ranged from 80.2 to 103.2%. The proposed method has been successfully applied to the analysis of five triazole fungicides in traditional Chinese medicine samples, and satisfactory results were obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  2. Proton therapy physics

    CERN Document Server

    2012-01-01

    Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also exami...

  3. Proton solvation and proton transfer in chemical and electrochemical processes

    International Nuclear Information System (INIS)

    Lengyel, S.; Conway, B.E.

    1983-01-01

    This chapter examines the proton solvation and characterization of the H 3 O + ion, proton transfer in chemical ionization processes in solution, continuous proton transfer in conductance processes, and proton transfer in electrode processes. Topics considered include the condition of the proton in solution, the molecular structure of the H 3 O + ion, thermodynamics of proton solvation, overall hydration energy of the proton, hydration of H 3 O + , deuteron solvation, partial molal entropy and volume and the entropy of proton hydration, proton solvation in alcoholic solutions, analogies to electrons in semiconductors, continuous proton transfer in conductance, definition and phenomenology of the unusual mobility of the proton in solution, solvent structure changes in relation to anomalous proton mobility, the kinetics of the proton-transfer event, theories of abnormal proton conductance, and the general theory of the contribution of transfer reactions to overall transport processes

  4. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  5. Proton minibeam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Girst, Stefanie

    2016-03-08

    in the skin tissue, but with significantly increased doses (up to 5000 Gy) compared to the average dose of 2 Gy, which was applied homogeneously in further skin samples for comparison. Gaussian-shaped minibeams of even larger sizes (σ=260 μm and 520 μm, inter-beam distance 1.8 mm) were analyzed in further experiments to evaluate the effect of increasing beam sizes as in deeper-lying tissues. Acute side effects were quantified via the MTT tissue viability test and the release of inflammatory proteins into the culture medium and showed improved results for minibeam compared to homogeneous irradiation. Genetic damage, an indicator for secondary tumor induction, was analyzed via the micronucleus test in the epidermal keratinocytes and was less than half for minibeams up to 180 μm size compared to homogeneous fields. Increasing minibeam sizes, i.e. increasing fractions of irradiated skin (receiving a dose higher than the average dose of 2 Gy) increased the number of micronuclei per divided cell, but never exceeded the genetic damage induced by a homogeneous dose distribution. A more authentic and representative in-vivo skin model, accounting for higher complexity with blood vessels, further cell types, follicles, glands and especially a working immune system, was used in the next step to further examine the side effects of minibeam radiotherapy compared to homogeneous irradiation. The central part of the ear of adult BALB/c mice was irradiated with 20 MeV protons, using an average dose of 60 Gy in a field of 7.2 x 7.2 mm{sup 2}. The 4 x 4 minibeams of nominal 6000 Gy had a size of 180 x 180 μm{sup 2} and inter-beam distances of 1.8 mm, as in previous in-vitro skin experiments. Minibeam irradiation induced no ear swelling or other visible skin reaction at any time, while significant ear swelling (up to 4-fold), skin reddening (erythema) and desquamation developed in homogeneously irradiated ears 3-4 weeks after irradiation. Loss of hair and sebaceous glands only

  6. SU-E-J-63: Feasibility Study of Proton Digital Tomosynthesis in Proton Beam Therapy.

    Science.gov (United States)

    Min, B; Kwak, J; Lee, J; Cho, S; Park, S; Yoo, S; Chung, K; Cho, S; Lim, Y; Shin, D; Lee, S; Kim, J

    2012-06-01

    We investigated the feasibility of proton tomosynthesis as daily positioning of patients and compared the results with photon tomosynthesis as an alternative to conventional portal imaging or on-board cone-beam computed tomography. Dedicated photon-like proton beam using the passively scattered proton beams by the cyclotron was generated for proton imaging. The eleven projections were acquired over 30 degree with 3 degree increment in order to investigate the performance of proton tomosynthesis. The cylinder blocks and resolution phantom were used to evaluate imaging performance. Resolution phantom of a cylinder of diameter 12 cm was used to investigate the reconstructed imaging characteristics. Electron density cylinder blocks with diameter of 28 mm and height of 70 mm were employed to assess the imaging quality. The solid water, breast, bone, adipose, lung, muscle, and liver, which were tissue equivalent inserts, were positioned around the resolution phantom. The images were reconstructed by projection onto convex sets (POCS) algorithm and total variation minimization (TVM) methods. The Gafchromic EBT films were utilized for measuring the photon-like proton beams as a proton detector. In addition, the photon tomosynthesis images were obtained for a comparison with proton tomosynthesis images. The same angular sampling data were acquired for both proton and photon tomosynthesis. In the resolution phantom image obtained proton tomosynthesis, down to 1.6 mm diameter rods were resolved visually, although the separation between adjacent rods was less distinct. In contrast, down to 1.2 mm diameter rods were resolved visually in the reconstructed image obtained photon tomosynthesis. Both proton and photon tomosynthesis images were similar in intensities of different density blocks. Our results demonstrated that proton tomosynthesis could make it possible to provide comparable tomography imaging to photon tomosynthesis for positioning as determined by manual registration

  7. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  8. Validation of an off line solid phase extraction liquid chromatography-tandem mass spectrometry method for the determination of systemic insecticide residues in honey and pollen samples collected in apiaries from NW Spain.

    Science.gov (United States)

    García-Chao, María; Agruña, María Jesús; Flores Calvete, Gonzalo; Sakkas, Vasilis; Llompart, María; Dagnac, Thierry

    2010-07-05

    The use of pesticides to protect crops against plagues and insects is one of the most important ways to assure agricultural quality and productivity. However, bad application practices may cause the contamination of different environmental compartments and animal species, as a consequence of migration or accumulation of those compounds. Fipronil, imidacloprid and thiametoxam are systemic or systemic-like insecticides widely used in maize crops. Their heavy action in the nervous system of target insects also means a high toxicity to non-target pollinator insects such as honey bees which can get in touch with them through pollen and nectar during foraging activities. These insecticides have even been suspected to cause a significant decrease of honeybee colonies that has been observed in many countries since the past decade. Since September 1st 2008, the European Commission set new MRLs in food and feed of plant and animal origin. The pesticides included in this study have MRLs in honey and pollen between 10 and 50 ng g(-1). In the present work, an analytical method was developed with the aim of determining residues of fipronil and some of its metabolites (fipronil sulfone, fipronil sulfide, fipronil desulfinyl and fipronil carboxamide), thiamethoxam and imidacloprid in honey and pollen samples. The extraction optimization was performed using a Doehlert experimental design by studying two factors, the mixture and the ratio of solvents used. Prior to the extraction procedure, raw hive samples containing honey, pollen and wax were centrifuged at 4000 rpm. The upper solid material was removed, and 1 g of the lower phase was mixed with 3 mL of the optimized mixture of methanol/water (10/90). The extract was passed through a florisil cartridge and the target compounds were eluted with methanol and analysed by LC-MS/MS in selective reaction monitoring (SRM) mode. The method was validated according to the guidelines included in the SANCO/10684/2009 document and the ISO

  9. Proton Fast Ignition

    International Nuclear Information System (INIS)

    Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

    2006-04-01

    Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

  10. Proton decay: spectroscopic probe beyond the proton drip line

    International Nuclear Information System (INIS)

    Seweryniak, D; Davids, C N; Robinson, A; Woods, P J; Blank, B; Carpenter, M P; Davinson, T; Freeman, S J; Hammond, N; Hoteling, N; Janssens, R V F; Khoo, T L; Liu, Z; Mukherjee, G; Shergur, J; Sinha, S; Sonzogni, A A; Walters, W B; Woehr, A

    2005-01-01

    Proton decay has been transformed in recent years from an exotic phenomenon into a powerful spectroscopic tool. The frontiers of experimental and theoretical proton-decay studies will be reviewed. Different aspects of proton decay will be illustrated with recent results on the deformed proton emitter 135 Tb, the odd-odd deformed proton emitter 130 Eu, the complex fine structure in the odd-odd 146 Tm nucleus and on excited states in the transitional proton emitter 145 Tm

  11. Review of inelastic proton-proton reactions

    CERN Document Server

    Morrison, Douglas Robert Ogston

    1973-01-01

    The most important new results on inelastic proton-proton scattering obtained with the new machines, I.S.R. and N.A.L., are: (1) The inelastic cross-section increases monotonically with energy from threshold to 1500 GeV/c. Above 6 GeV/c the energy variation has a s /sup +0.04/ behaviour. (2) Scaling is observed at I.S.R. energies in pion production. Confirmation is obtained of the hypothesis of limiting fragmentation. (3) The results are in general, consistent with the two-component model-one class of events being produced by diffraction dissociation and the other by a short-range-order process (e.g. the multiperipheral model). (4) There are indications that the protons have a granular structure; this from observation of secondaries of large transverse momenta. (33 refs).

  12. Fragment mass distribution of proton-induced spallation reaction with intermediate energy

    International Nuclear Information System (INIS)

    Fan Sheng; Ye Yanlin; Xu Chuncheng; Chen Tao; Sobolevsky, N.M.

    2000-01-01

    The test of part benchmark of SHIELD code is finished. The fragment cross section and mass distribution and excitation function of the residual nuclei from proton-induced spallation reaction on thin Pb target with intermediate energy have been calculated by SHIELD code. And the results are in good agreement with measured data. The fragment mass distribution of the residual nuclei from proton-induced spallation reaction on thick Pb target with incident energy 1.6 GeV have been simulated

  13. Giving Protons a Boost

    CERN Multimedia

    2004-01-01

    The first of LHC's superconducting radio-frequency cavity modules has passed its final test at full power in the test area of building SM18. These modules carry an oscillating electric field that will accelerate protons around the LHC ring and help maintain the stability of the proton beams.

  14. On the proton decay

    International Nuclear Information System (INIS)

    Fonda, L.; Ghirardi, G.C.; Weber, T.

    1983-07-01

    The problem of the proton decay is considered taking into account that in actual experiments there is an interaction of the proton with its environment which could imply an increase of its theoretical lifetime. It is seen that, by application of the time-energy uncertainty relation, no prolongation of the lifetime is obtained in this case. (author)

  15. PS proton source

    CERN Multimedia

    1959-01-01

    The first proton source used at CERN's Proton Synchrotron (PS) which started operation in 1959. This is CERN's oldest accelerator still functioning today (2018). It is part of the accelerator chain that supplies proton beams to the Large Hadron Collider. The source is a Thonemann type. In order to extract and accelerate the protons at high energy, a high frequency electrical field is used (140Mhz). The field is transmitted by a coil around a discharge tube in order to maintain the gas hydrogen in an ionised state. An electrical field pulse, in the order of 15kV, is then applied via an impulse transformer between anode and cathode of the discharge tube. The electrons and protons of the plasma formed in the ionised gas in the tube, are then separated. Currents in the order of 200mA during 100 microseconds have benn obtained with this type of source.

  16. Proton adsorption onto alumina: extension of multisite complexation (MUSIC) theory

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, K.; Blum, F.D.

    1999-09-01

    The adsorption isotherm of protons onto a commercial {gamma}-alumina sample was determined in aqueous nitric acid with sodium nitrate as a background electrolyte. Three discrete regions could be discerned in the log-log plots of the proton isotherm determined at the solution pH 5 to 2. The multisite complexation (MUSIC) model was modified to analyze the simultaneous adsorption of protons onto various kinds of surface species.

  17. Proton-proton colliding beam facility ISABELLE

    International Nuclear Information System (INIS)

    Hahn, H.

    1980-01-01

    This paper attempts to present the status of the ISABELLE construction project, which has the objective of building a 400 + 400 GeV proton colliding beam facility. The major technical features of the superconducting accelerators with their projected performance are described. Progress made so far, difficulties encountered, and the program until completion in 1986 is briefly reviewed

  18. Pesticide residues in locally available cereals and vegetables

    International Nuclear Information System (INIS)

    Cunanan, S.A.; Santos, F.L.; Bonoan, L.S.

    1976-03-01

    Vegetable samples (pechay, cabbage, lettuce, green beans and tomatoes) bought from public markets in the Metro Manila area were analyzed for pesticide residues using gas chromatography. The samples analyzed in 1968-69 contained high levels of chlorinated pesticides such as DDT, Aldrin, Endrin, and Thiodan, while in the samples analyzed in January 1976, no chlorinated and organophosphate pesticides were detected. Cereal samples (rice, corn and sorghum) were obtained from the National Grains Authority and analyzed for pesticide residues and bromine residues. Total bromine residues was determined by neutron activation analysis. In most of the samples analyzed, the concentrations of pesticide residues were below the tolerance levels set by the FAO/WHO Committee on Pesticide Residues in Foods. An exception was one rice sample from Thailand, the bromine residue content (110ppm) of which exceeds the tolerance level of 50ppm

  19. Coking of residue hydroprocessing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gray, M.R.; Zhao, Y.X. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical Engineering; McKnight, C.A. [Syncrude Canada Ltd., Edmonton, AB (Canada); Komar, D.A.; Carruthers, J.D. [Cytec Industries Inc., Stamford, CT (United States)

    1997-11-01

    One of the major causes of deactivation of Ni/Mo and Co/Mo sulfide catalysts for hydroprocessing of heavy petroleum and bitumen fractions is coke deposition. The composition and amount of coke deposited on residue hydroprocessing catalysts depends on the composition of the liquid phase of the reactor. In the Athabasca bitumen, the high molecular weight components encourage coke deposition at temperatures of 430 to 440 degrees C and at pressures of 10 to 20 MPa hydrogen pressure. A study was conducted to determine which components in the heavy residual oil fraction were responsible for coking of catalysts. Seven samples of Athabasca vacuum residue were prepared by supercritical fluid extraction with pentane before being placed in the reactor. Carbon content and hydrodesulfurization activity was measured. It was concluded that the deposition of coke depended on the presence of asphaltenes and not on other compositional variables such as content of nitrogen, aromatic carbon or vanadium.

  20. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  1. ATLAS Forward Proton Detector

    CERN Document Server

    Grieco, Chiara; The ATLAS collaboration

    2018-01-01

    The aim of the ATLAS Forward Proton (AFP) detector system is the measurement of protons scattered diffractively or electromagnetically at very small angles. The full two-arm setup was installed during the 2016/2017 EYETS. This allows measurements of processes with two forward protons: central diffraction, exclusive production, and two-photon processes. In 2017, AFP participated in the ATLAS high-luminosity data taking on the day-by-day basis. In addition, several special runs with reduced luminosity were taken. The poster will present the AFP detectors and the lessons learned from the last year operation and some performance from 2016 and 2017.

  2. Laryngeal adenocystic carcinoma treated by proton therapy

    International Nuclear Information System (INIS)

    Sugiyama, Tomonori; Araki, Mamika; Fukukita, Kouhei; Yamada, Hiroyuki

    2013-01-01

    Adenocystic carcinoma most commonly develops in the major salivary glands, on the other hand it is rare for adenocystic carcinoma to develop in the larynx. We report a case of adenocystic carcinoma in the larynx. A 54-year-old male was hospitalized with symptoms of hoarseness and dyspnea on exertion. He presented a tumor that developed at the base of the right arytenoid, and covered over the glottis. It was confirmed to be adenocystic carcinoma (solid type) by biopsy. Positron emission tomography (PET)-CT also revealed a left cervical lymph node metastasis and multiple pulmonary metastases (T1N2cM1). He was treated with proton therapy to the larynx to prevent airway obstruction by growth of the tumor and to preserve the larynx because he had uncontrollable pulmonary metastasis. Although the tumor vanished after the treatment, one month later he had halitosis, dyspnea and bilateral vocal cord palsy. Despite administration of an antibacterial drug and steroid, there was no improvement to the narrowness of the glottis. A tracheotomy was therefore performed three months after the proton therapy. PET-CT, which was performed after the tracheotomy, suggested growth of the residual tumor or laryngeal radionecrosis. This study confirmed that proton therapy is effective for adenocystic carcinoma in the larynx. However, proton therapy also was found to cause laryngeal radionecrosis. These results indicate the importance of evaluating the side effects of radiation therapy and providing that information to the patient. (author)

  3. Addendum to Sampling and Analysis Plan (SAP) for Assessment of LANL-Derived Residual Radionuclides in Soils within Tract A-16-d for Land Conveyance and Transfer for Sewage Treatment Facility Area

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey Jay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gillis, Jessica Mcdonnel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-21

    This report summarizes the sampling design used, associated statistical assumptions, as well as general guidelines for conducting post-sampling data analysis. Sampling plan components presented here include how many sampling locations to choose and where within the sampling area to collect those samples. The type of medium to sample (i.e., soil, groundwater, etc.) and how to analyze the samples (in-situ, fixed laboratory, etc.) are addressed in other sections of the sampling plan.

  4. Using cotton plant residue to produce briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Coates, W. [University of Arizona, Tucson, AZ (United States). Bioresources Research Facility

    2000-07-01

    In Arizona, cotton (Gossypium) plant residue left in the field following harvest must be buried to prevent it from serving as an overwintering site for insects such as the pink bollworm. Most tillage operations employed to incorporate the residue into the soil are energy intensive and often degrade soil structure. Trials showed that cotton plant residue could be incorporated with pecan shells to produce commercially acceptable briquettes. Pecan shell briquettes containing cotton residue rather than waste paper were slightly less durable, when made using equivalent weight mixtures and moisture contents. Proximate and ultimate analyses showed the only difference among briquette samples to be a higher ash content in those made using cotton plant residue. Briquettes made with paper demonstrated longer flame out time, and lower ash percentage, compared to those made with cotton plant residue. (author)

  5. PROTON RADIOGRAPHY WITH THE PIXEL DETECTOR TIMEPIX

    Directory of Open Access Journals (Sweden)

    Václav Olšanský

    2016-12-01

    Full Text Available This article presents the processing of radiographic data acquired using the position-sensitive hybrid semiconductor pixel detector Timepix. Measurements were made on thin samples at the medical ion-synchrotron HIT [1] in Heidelberg (Germany with a 221 MeV proton beam. The charge is energy by the particles crossing the sample is registered for generation of image contrast. Experimental data from the detector were processed for derivation of the energy loss of each proton using calibration matrices. The interaction point of the protons on the detector were determined with subpixel resolution by model fitting of the individual signals in the pixelated matrix. Three methods were used for calculation of these coordinates: Hough transformation, 2D Gaussian fitting and estimate the 2D mean. Parameters of calculation accuracy and calculation time are compared for each method. The final image was created by method with best parameters.

  6. Proton computed tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1978-01-01

    The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible

  7. Electron - proton colliders

    International Nuclear Information System (INIS)

    Wiik, B.H.

    1985-01-01

    Electron-proton storage rings allow us to study the interaction between the two basic constituents of matter, electrons and quarks at very short distances. Such machines were first discussed in connection with the ISR but the idea was abandoned because of the anticipated low counting rate. The interest in electron-proton storage rings was rekindeled by the discovery of large pointlike cross sections in lepton-hardon interactions and several/sup 2-15/ projects have been discussed during the past decade. However, despite a glorious past, which includes the discovery of quarks and neutral currents, and a multitude of proposals no electron-proton storage ring has ever been built. What we might learn by studying electron-proton collisions at high energies is discussed. After some brief comments on present proposals the proposed DESY ep project HERA is described as an example of how to realize such a machine

  8. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react...

  9. Inauguration of Proton Synchrotron

    CERN Multimedia

    1960-01-01

    On 5 February 1960, the Proton Synchrotron (PS) was formally inaugurated. The great Danish physicist, Niels Bohr, releases a bottle of champagne against a shielding block to launch the PS on its voyage in physics.

  10. Proton beam therapy facility

    International Nuclear Information System (INIS)

    1984-01-01

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs

  11. Proton beam therapy facility

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-09

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs.

  12. Out-and-back {sup 13}C-{sup 13}C scalar transfers in protein resonance assignment by proton-detected solid-state NMR under ultra-fast MAS

    Energy Technology Data Exchange (ETDEWEB)

    Barbet-Massin, Emeline; Pell, Andrew J. [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France); Jaudzems, Kristaps [Latvian Institute of Organic Synthesis (Latvia); Franks, W. Trent; Retel, Joren S. [Leibniz-Institut fuer Molekulare Pharmakologie (Germany); Kotelovica, Svetlana; Akopjana, Inara; Tars, Kaspars [Biomedical Research and Study Center (Latvia); Emsley, Lyndon [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France); Oschkinat, Hartmut [Leibniz-Institut fuer Molekulare Pharmakologie (Germany); Lesage, Anne; Pintacuda, Guido, E-mail: guido.pintacuda@ens-lyon.fr [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France)

    2013-08-15

    We present here {sup 1}H-detected triple-resonance H/N/C experiments that incorporate CO-CA and CA-CB out-and-back scalar-transfer blocks optimized for robust resonance assignment in biosolids under ultra-fast magic-angle spinning (MAS). The first experiment, (H)(CO)CA(CO)NH, yields {sup 1}H-detected inter-residue correlations, in which we record the chemical shifts of the CA spins in the first indirect dimension while during the scalar-transfer delays the coherences are present only on the longer-lived CO spins. The second experiment, (H)(CA)CB(CA)NH, correlates the side-chain CB chemical shifts with the NH of the same residue. These high sensitivity experiments are demonstrated on both fully-protonated and 100 %-H{sup N} back-protonated perdeuterated microcrystalline samples of Acinetobacter phage 205 (AP205) capsids at 60 kHz MAS.

  13. PROTON MICROSCOPY AT FAIR

    International Nuclear Information System (INIS)

    Merrill, F. E.; Mariam, F. G.; Golubev, A. A.; Turtikov, V. I.; Varentsov, D.

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and a facility has been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international effort has investigated a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located in Darmstadt, Germany. This new Proton microscope for FAIR(PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. It is also proposed to install the PRIOR system at the GSI Helmholtzzentrum fuer Schwerionenforschung before installation at FAIR for dynamic experiments with different drivers including high explosives, pulsed power and lasers. The design of the proton microscope and expected radiographic performance is presented.

  14. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  15. Proton Radiography to Improve Proton Radiotherapy : Simulation Study at Different Proton Beam Energies

    NARCIS (Netherlands)

    Biegun, Aleksandra; Takatsu, Jun; van Goethem, Marc-Jan; van der Graaf, Emiel; van Beuzekom, Martin; Visser, Jan; Brandenburg, Sijtze

    To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a

  16. Ionization of tyrosine residues in human serum albumin and in its complexes with bilirubin and laurate

    DEFF Research Database (Denmark)

    Honoré, B; Brodersen, R

    1992-01-01

    Spectrophotometric titration of human serum albumin indicates that ionization of the 18 tyrosine residues takes place between pH 9 and 12.7. A Hill plot indicates that protons dissociate co-operatively from tyrosine residues, in pure albumin between pH 11.0 and 11.4 with a Hill coefficient 1.7, a...

  17. The NAP-M proton storage

    International Nuclear Information System (INIS)

    Anashin, V.V.; Budker, G.I.; Bulushev, A.F.

    1976-01-01

    A magnetic and vacuum system is described of a proton accumulator designed for electronic-cooling experiments. The magnetic system of the accumulator is determined by the specific nature of electronic cooling and accumulation. To improve the cooling efficiency, the accumulator is provided with long rectilinear gaps for placing installations with an electron beam. A system with a zero gradient and edge focusing has been chosen as the focusing system. The vacuum system of the accumulator provides a residual pressure of 5x10 -11 Torr

  18. Activation of 45-MeV proton irradiation and proton-induced neutron irradiation in polymers

    International Nuclear Information System (INIS)

    Ra, Se-Jin; Kim, Kye-Ryung; Jung, Myung-Hwan; Yang, Tae-Keon

    2010-01-01

    During beam irradiation experiments with more than a few MeV energetic protons, the sample activation problem can be very severe because it causes many kinds of additional problems for the post-processing of the samples, such as time loss, inconvenience of sample handling, personal radiation safety, etc. The most serious problem is that immediate treatment of the sample is impossible in some experiments, such as nano-particle synthesizing. To solve these problems, we studied why the samples are activated and how the level of the activation can be reduced. It is known that the main reasons of activation are nuclear reactions with elements of the target material by primary protons and secondary produced neutrons. Even though the irradiation conditions are same, the level of the activation can be different depending on the target materials. For the nanoparticle synthesizing experiments, the target materials can be defined as the container and the sample itself. The reduction of the activation from the container is easier than the reduction from the sample. Therefore, we tried to reduce the activation level by changing the container materials. In this paper, the results are displayed for some candidate container materials, such as polymethyl methacrylate, polystyrene, Glass, etc., with 45-MeV and 10-nA proton beams. As a result, PS is the most suitable material for the container because of its relatively low level of the activation by protons. Also the contribution of secondary produced neutrons to the activation is negligible.

  19. Proton therapy in Australia

    International Nuclear Information System (INIS)

    Jackson, M.

    2000-01-01

    Full text: Proton therapy has been in use since 1954 and over 25,000 patients have been treated worldwide. Until recently most patients were treated at physics research facilities but with the development of more compact and reliable accelerators it is now possible to realistically plan for proton therapy in an Australian hospital. The Australian National Proton Project has been formed to look at the feasibility of a facility which would be primarily for patient treatment but would also be suitable for research and commercial applications. A detailed report will be produced by the end of the year. The initial clinical experience was mainly with small tumours and other lesions close to critical organs. Large numbers of eye tumours have also been treated. Protons have a well-defined role in these situations and are now being used in the treatment of more common cancers. With the development of hospital-based facilities, over 2,500 patients with prostate cancer have been treated using a simple technique which gives results at least as good as radical surgery, external beam radiotherapy or brachytherapy. Importantly, the incidence of severe complications is very low. There are encouraging results in many disease sites including lung, liver, soft tissue sarcomas and oesophagus. As proton therapy becomes more widely available, randomised trials comparing it with conventional radiotherapy or Intensity Modulated Radiation Therapy (IMRT) will be possible. In most situations the use of protons will enable a higher dose to be given safely but in situations where local control rates are already satisfactory, protons are expected to produce less complications than conventional treatment. The initial costs of a proton facility are high but the recurrent costs are similar to other forms of high technology radiotherapy. . Simple treatment techniques with only a few fields are usually possible and proton therapy avoids the high integral doses associated with IMRT. This reduction in

  20. A survey of residual analysis and a new test of residual trend.

    Science.gov (United States)

    McDowell, J J; Calvin, Olivia L; Klapes, Bryan

    2016-05-01

    A survey of residual analysis in behavior-analytic research reveals that existing methods are problematic in one way or another. A new test for residual trends is proposed that avoids the problematic features of the existing methods. It entails fitting cubic polynomials to sets of residuals and comparing their effect sizes to those that would be expected if the sets of residuals were random. To this end, sampling distributions of effect sizes for fits of a cubic polynomial to random data were obtained by generating sets of random standardized residuals of various sizes, n. A cubic polynomial was then fitted to each set of residuals and its effect size was calculated. This yielded a sampling distribution of effect sizes for each n. To test for a residual trend in experimental data, the median effect size of cubic-polynomial fits to sets of experimental residuals can be compared to the median of the corresponding sampling distribution of effect sizes for random residuals using a sign test. An example from the literature, which entailed comparing mathematical and computational models of continuous choice, is used to illustrate the utility of the test. © 2016 Society for the Experimental Analysis of Behavior.

  1. Proton dynamics in cancer.

    Science.gov (United States)

    Huber, Veronica; De Milito, Angelo; Harguindey, Salvador; Reshkin, Stephan J; Wahl, Miriam L; Rauch, Cyril; Chiesi, Antonio; Pouysségur, Jacques; Gatenby, Robert A; Rivoltini, Licia; Fais, Stefano

    2010-06-15

    Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth.Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  2. Proton dynamics in cancer

    Directory of Open Access Journals (Sweden)

    Pouysségur Jacques

    2010-06-01

    Full Text Available Abstract Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth. Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  3. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  4. Journal of Proton Therapy

    Directory of Open Access Journals (Sweden)

    Editorial Office

    2015-01-01

    Full Text Available Journal of Proton Therapy (JPT is an international open access, peer-reviewed journal, which publishes original research, technical reports, reviews, case reports, editorials, and other materials on proton therapy with focus on radiation oncology, medical physics, medical dosimetry, and radiation therapy.No article processing/submission feeNo publication feePeer-review completion within 3-6 weeksImmediate publication after the completion of final author proofreadDOI assignment for each published articleFree access to published articles for all readers without any access barriers or subscriptionThe views and opinions expressed in articles are those of the author/s and do not necessarily reflect the policies of the Journal of Proton Therapy.Authors are encouraged to submit articles for publication in the inaugural issue of the Journal of Proton Therapy by online or email to editor@protonjournal.comOfficial Website of Journal of Proton Therapy: http://www.protonjournal.org/

  5. Medical Proton Accelerator Project

    International Nuclear Information System (INIS)

    Comsan, M.N.H.

    2008-01-01

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  6. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  7. Proton relativistic model; Modelo relativistico do proton

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wilson Roberto Barbosa de

    1996-12-31

    In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author) 42 refs., 22 figs., 1 tab.

  8. Modification of polycrystalline copper by proton irradiation

    International Nuclear Information System (INIS)

    Garcia S, F.; Cabral P, A.; Saniger B, J.M.; Banuelos, J.G.; Barragan V, A.

    1997-01-01

    Polished copper samples were irradiated with proton beams of 300 and 700 keV at room temperature and at -150 Centigrade. In this work the obtained results are reported when such copper irradiated samples are analysed with Sem, Tem, AFM. The Sem micrographs showed evident changes in surface of these copper samples, therefore an EDAX microanalysis was done for its characterization. additionally, the Tem micrographs showed heaps formation until 200 nm. Its electron diffraction spectra indicated that these heaps consist of a copper compound. Finally with AFM were observed changes in coloration of the irradiated sample surface, as well as changes in texture and rugosity of them. These results show in general that irradiation process with protons which is known as an innocuo process produces changes in the copper properties. (Author)

  9. Proton-gamma coincidence experiment on medium mass nuclei at 400MeV and study of reaction mechanisms

    International Nuclear Information System (INIS)

    Baldit, Alain.

    1981-01-01

    Previous γ ray production experiments produced by proton on nuclei show important cross sections for residual nuclei corresponding to a four nucleon (2p + 2n) removal. With our (p - γ) coincidence experiment the forward emitted proton reflects the primary interaction and the γ spectra characterizes the final state of the reaction. Protons are detected with a magnetic spectrometer and γ rays are selected with a Ge(Li) diode. Angular and momentum analysis of scattered protons demonstrate a primary quasi free process on nucleons. No indication of knock out reactions on clusters has been seen. The residual nuclei are mainly produced by evaporation processes. A theoretical calculation involving intranuclear cascades and evaporation processes has been performed. The nucleus model is based upon a Fermi gas and nuclear density agrees with diffusion electron experiments. Residual nuclei far from target are well described with a such model. Residual nuclei near the target are sensitive to the nuclear structure [fr

  10. Stabilization of plutonium bearing residues at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Bronson, M.C.; Van Konynenburg, R.A.; Ebbinghaus, B.B.

    1995-01-01

    The US Department of Energy's (US DOE) Lawrence Livermore National Laboratory (LLNL) has plutonium holdings including metal, oxide and residue materials, all of which need stabilization of some type. Residue materials include calcined ash, calcined precipitates, pyrochemical salts, glove box sweepings, metallurgical samples, graphite, and pyrochemical ceramic crucibles. These residues are typical of residues stored throughout the US DOE plutonium sites. The stabilization process selected for each of these residues requires data on chemical impurities, physical attributes, and chemical forms of the plutonium. This paper outlines the characterization and stabilization of LLNL ash residues, pyrochemical salts, and graphite

  11. Synchrotron radiation from protons

    International Nuclear Information System (INIS)

    Dutt, S.K.

    1992-12-01

    Synchrotron radiation from protons, though described by the same equations as the radiation from electrons, exhibits a number of interesting features on account of the parameters reached in praxis. In this presentation, we shall point out some of the features relating to (i) normal synchrotron radiation from dipoles in proton machines such as the High Energy Booster and the Superconducting Super Collider; (ii) synchrotron radiation from short dipoles, and its application to light monitors for proton machines, and (iii) synchrotron radiation from undulators in the limit when, the deflection parameter is much smaller than unity. The material for this presentation is taken largely from the work of Hofmann, Coisson, Bossart, and their collaborators, and from a paper by Kim. We shall emphasize the qualitative aspects of synchrotron radiation in the cases mentioned above, making, when possible, simple arguments for estimating the spectral and angular properties of the radiation. Detailed analyses can be found in the literature

  12. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  13. Long-Range Electrostatics-Induced Two-Proton Transfer Captured by Neutron Crystallography in an Enzyme Catalytic Site.

    Science.gov (United States)

    Gerlits, Oksana; Wymore, Troy; Das, Amit; Shen, Chen-Hsiang; Parks, Jerry M; Smith, Jeremy C; Weiss, Kevin L; Keen, David A; Blakeley, Matthew P; Louis, John M; Langan, Paul; Weber, Irene T; Kovalevsky, Andrey

    2016-04-11

    Neutron crystallography was used to directly locate two protons before and after a pH-induced two-proton transfer between catalytic aspartic acid residues and the hydroxy group of the bound clinical drug darunavir, located in the catalytic site of enzyme HIV-1 protease. The two-proton transfer is triggered by electrostatic effects arising from protonation state changes of surface residues far from the active site. The mechanism and pH effect are supported by quantum mechanics/molecular mechanics (QM/MM) calculations. The low-pH proton configuration in the catalytic site is deemed critical for the catalytic action of this enzyme and may apply more generally to other aspartic proteases. Neutrons therefore represent a superb probe to obtain structural details for proton transfer reactions in biological systems at a truly atomic level. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Current-current interaction picture for proton-proton scattering

    International Nuclear Information System (INIS)

    Clarke, D.J.; Lo, S.Y.

    1979-01-01

    The authors propose that color current - color current interaction is reponsible for small angle elastic proton proton scattering at asymptotic energy. Excellent fits are obtained for all data above 12 GeV/c which covers twelve orders of magnitude

  15. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Veierskov, Bjarke

    2008-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells...... of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic...... molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...

  16. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  17. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-01-01

    It was found that female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was determined to be 7 years after the proton exposure. The doses and energies of the radiation received by the experimental animals were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event. It is concluded that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crew members. 15 references

  18. Diagnosis by proton bombardment

    International Nuclear Information System (INIS)

    Steward, V.W.; Koehler, A.M.

    1976-01-01

    Beams of monoenergetic protons or other charged ions are passed through the living human body to detect abnormalities and obstructions in body tissue, which abnormalities and obstructions are visualized as density variations in the particle image emerging from the body part under investigation. The particles used are preferably protons having an energy of 100 to 300 MeV, more especially 200 to 300 MeV. The method is of use in detecting inter alia tumors, blood clots, infarcts, soft tissue lesions and multiple sclerosis in patients without exposure to high radiation dosages. 6 claims, 2 drawing figures

  19. Proton tunneling in solids

    International Nuclear Information System (INIS)

    Kondo, J.

    1998-01-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  20. H+-type and OH−-type biological protonic semiconductors and complementary devices

    Science.gov (United States)

    Deng, Yingxin; Josberger, Erik; Jin, Jungho; Rousdari, Anita Fadavi; Helms, Brett A.; Zhong, Chao; Anantram, M. P.; Rolandi, Marco

    2013-01-01

    Proton conduction is essential in biological systems. Oxidative phosphorylation in mitochondria, proton pumping in bacteriorhodopsin, and uncoupling membrane potentials by the antibiotic Gramicidin are examples. In these systems, H+ hop along chains of hydrogen bonds between water molecules and hydrophilic residuesproton wires. These wires also support the transport of OH− as proton holes. Discriminating between H+ and OH− transport has been elusive. Here, H+ and OH− transport is achieved in polysaccharide- based proton wires and devices. A H+- OH− junction with rectifying behaviour and H+-type and OH−-type complementary field effect transistors are demonstrated. We describe these devices with a model that relates H+ and OH− to electron and hole transport in semiconductors. In turn, the model developed for these devices may provide additional insights into proton conduction in biological systems. PMID:24089083

  1. H+-type and OH- -type biological protonic semiconductors and complementary devices.

    Science.gov (United States)

    Deng, Yingxin; Josberger, Erik; Jin, Jungho; Roudsari, Anita Fadavi; Rousdari, Anita Fadavi; Helms, Brett A; Zhong, Chao; Anantram, M P; Rolandi, Marco

    2013-10-03

    Proton conduction is essential in biological systems. Oxidative phosphorylation in mitochondria, proton pumping in bacteriorhodopsin, and uncoupling membrane potentials by the antibiotic Gramicidin are examples. In these systems, H(+) hop along chains of hydrogen bonds between water molecules and hydrophilic residues - proton wires. These wires also support the transport of OH(-) as proton holes. Discriminating between H(+) and OH(-) transport has been elusive. Here, H(+) and OH(-) transport is achieved in polysaccharide- based proton wires and devices. A H(+)- OH(-) junction with rectifying behaviour and H(+)-type and OH(-)-type complementary field effect transistors are demonstrated. We describe these devices with a model that relates H(+) and OH(-) to electron and hole transport in semiconductors. In turn, the model developed for these devices may provide additional insights into proton conduction in biological systems.

  2. Proton-proton bremsstrahlung in a relativistic covariant model

    NARCIS (Netherlands)

    Martinus, Gerard Henk

    1998-01-01

    Proton-proton bremsstrahlung is one of the simplest processes involving the half off-shell NN interaction. Since protons are equally-charged particles with the same mass, electric-dipole radiation is suppressed and higher-order effects play an important role. Thus it is possible to get information

  3. Predictions of diffractive cross sections in proton-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Goulianos, Konstantin [Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States)

    2013-04-15

    We review our pre-LHC predictions of the total, elastic, total-inelastic, and diffractive components of proton-proton cross sections at high energies, expressed in the form of unitarized expressions based on a special parton-model approach to diffraction employing inclusive proton parton distribution functions and QCD color factors and compare with recent LHC results.

  4. Electron transfer activation of a second water channel for proton transport in [FeFe]-hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Sode, Olaseni; Voth, Gregory A., E-mail: gavoth@uchicago.edu [Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, Computation Institute, The University of Chicago, Chicago, Illinois 60637, USA and Computing, Environment and Life Sciences, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-12-14

    Hydrogenase enzymes are important because they can reversibly catalyze the production of molecular hydrogen. Proton transport mechanisms have been previously studied in residue pathways that lead to the active site of the enzyme via residues Cys299 and Ser319. The importance of this pathway and these residues has been previously exhibited through site-specific mutations, which were shown to interrupt the enzyme activity. It has been shown recently that a separate water channel (WC2) is coupled with electron transport to the active site of the [FeFe]-hydrogenase. The water-mediated proton transport mechanisms of the enzyme in different electronic states have been studied using the multistate empirical valence bond reactive molecular dynamics method, in order to understand any role WC2 may have in facilitating the residue pathway in bringing an additional proton to the enzyme active site. In a single electronic state A{sup 2−}, a water wire was formed through which protons can be transported with a low free energy barrier. The remaining electronic states were shown, however, to be highly unfavorable to proton transport in WC2. A double amino acid substitution is predicted to obstruct proton transport in electronic state A{sup 2-} by closing a cavity that could otherwise fill with water near the proximal Fe of the active site.

  5. Electron transfer activation of a second water channel for proton transport in [FeFe]-hydrogenase

    International Nuclear Information System (INIS)

    Sode, Olaseni; Voth, Gregory A.

    2014-01-01

    Hydrogenase enzymes are important because they can reversibly catalyze the production of molecular hydrogen. Proton transport mechanisms have been previously studied in residue pathways that lead to the active site of the enzyme via residues Cys299 and Ser319. The importance of this pathway and these residues has been previously exhibited through site-specific mutations, which were shown to interrupt the enzyme activity. It has been shown recently that a separate water channel (WC2) is coupled with electron transport to the active site of the [FeFe]-hydrogenase. The water-mediated proton transport mechanisms of the enzyme in different electronic states have been studied using the multistate empirical valence bond reactive molecular dynamics method, in order to understand any role WC2 may have in facilitating the residue pathway in bringing an additional proton to the enzyme active site. In a single electronic state A 2− , a water wire was formed through which protons can be transported with a low free energy barrier. The remaining electronic states were shown, however, to be highly unfavorable to proton transport in WC2. A double amino acid substitution is predicted to obstruct proton transport in electronic state A 2- by closing a cavity that could otherwise fill with water near the proximal Fe of the active site

  6. Progresses in proton radioactivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, L. S., E-mail: flidia@ist.utl.pt [Center of Physics and Engineering of Advanced Materials, CeFEMA and Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Maglione, E. [Dipartimento di Fisica e Astronomia “G. Galilei”, Via Marzolo 8, I-35131 Padova, Italy and Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    2016-07-07

    In the present talk, we will discuss recent progresses in the theoretical study of proton radioactivity and their impact on the present understanding of nuclear structure at the extremes of proton stability.

  7. Proton Radiography (pRad)

    Data.gov (United States)

    Federal Laboratory Consortium — The proton radiography project has used 800 MeV protons provided by the LANSCE accelerator facility at LANL, to diagnose more than 300 dynamic experiments in support...

  8. Fractionated proton beam irradiation of pituitary adenomas

    International Nuclear Information System (INIS)

    Ronson, Brian B.; Schulte, Reinhard W.; Han, Khanh P.; Loredo, Lilia N.; Slater, James M.; Slater, Jerry D.

    2006-01-01

    Purpose: Various radiation techniques and modalities have been used to treat pituitary adenomas. This report details our experience with proton treatment of these tumors. Methods and Materials: Forty-seven patients with pituitary adenomas treated with protons, who had at least 6 months of follow-up, were included in this analysis. Forty-two patients underwent a prior surgical resection; 5 were treated with primary radiation. Approximately half the tumors were functional. The median dose was 54 cobalt-gray equivalent. Results: Tumor stabilization occurred in all 41 patients available for follow-up imaging; 10 patients had no residual tumor, and 3 had greater than 50% reduction in tumor size. Seventeen patients with functional adenomas had normalized or decreased hormone levels; progression occurred in 3 patients. Six patients have died; 2 deaths were attributed to functional progression. Complications included temporal lobe necrosis in 1 patient, new significant visual deficits in 3 patients, and incident hypopituitarism in 11 patients. Conclusion: Fractionated conformal proton-beam irradiation achieved effective radiologic, endocrinological, and symptomatic control of pituitary adenomas. Significant morbidity was uncommon, with the exception of postradiation hypopituitarism, which we attribute in part to concomitant risk factors for hypopituitarism present in our patient population

  9. Statistical Characterization of the Charge State and Residue Dependence of Low-Energy CID Peptide Dissociation Patterns

    International Nuclear Information System (INIS)

    Huang, Yingying; Triscari, Joseph M.; Tseng, George C.; Pasa-Tolic, Ljiljana; Lipton, Mary S.; Smith, Richard D.; Wysocki, Vicki H.

    2005-01-01

    Data mining was performed on 28 330 unique peptide tandem mass spectra for which sequences were assigned with high confidence. By dividing the spectra into different sets based on structural features and charge states of the corresponding peptides, chemical interactions involved in promoting specific cleavage patterns in gas-phase peptides were characterized. Pairwise fragmentation maps describing cleavages at all Xxx-Zzz residue combinations for b and y ions reveal that the difference in basicity between Arg and Lys results in different dissociation patterns for singly charged Arg- and Lys-ending tryptic peptides. While one dominant protonation form (proton localized) exists for Arg-ending peptides, a heterogeneous population of different protonated forms or more facile interconversion of protonated forms (proton partially mobile) exists for Lys-ending peptides. Cleavage C-terminal to acidic residues dominates spectra from peptides that have a localized proton and cleavage N-terminal to Pro dominates those that have a mobile or partially mobile proton. When Pro is absent from peptides that have a mobile or partially mobile proton, cleavage at each peptide bond becomes much more prominent. Whether the above patterns can be found in b ions, y ions, or both depends on the location of the proton holder(s). Enhanced cleavages C-terminal to branched aliphatic residues (Ile, Val, Leu) are observed in both b and y ions from peptides that have a mobile proton, as well as in y ions from peptides that have a partially mobile proton; enhanced cleavages N-terminal to these residues are observed in b ions from peptides that have a partially mobile proton. Statistical tools have been designed to visualize the fragmentation maps and measure the similarity between them. The pairwise cleavage patterns observed expand our knowledge of peptide gas-phase fragmentation behaviors and should be useful in algorithm development that employs improved models to predict fragment ion

  10. Violent collisions of spinning protons

    Energy Technology Data Exchange (ETDEWEB)

    Krisch, A.D. [Michigan Univ., Spin Physics Center, Ann Arbor, MI (United States)

    2005-07-01

    The author draws the history of polarized proton beams that has relied on experiments that took place in different accelerators like ZGS (zero gradient synchrotron, Argonne), AGS (Brookhaven) and Fermilab from 1973 till today. The first studies of the behavior and spin-manipulation of polarized protons helped in developing polarized beams around the world: Brookhaven now has 200 GeV polarized protons in the RHIC collider, perhaps someday the 7 TeV LHC at CERN might have polarized protons.

  11. Neutron-proton scattering

    International Nuclear Information System (INIS)

    Doll, P.

    1990-02-01

    Neutron-proton scattering as fundamental interaction process below and above hundred MeV is discussed. Quark model inspired interactions and phenomenological potential models are described. The seminar also indicates the experimental improvements for achieving new precise scattering data. Concluding remarks indicate the relevance of nucleon-nucleon scattering results to finite nuclei. (orig.) [de

  12. Radiotherapy : proton therapy

    International Nuclear Information System (INIS)

    1991-01-01

    The first phase of proton therapy at the National Accelerator Centre will be the development of a 200 MeV small-field horizontal beam radioneurosurgical facility in the south treatment vault. A progressive expansion of this facility is planned. The patient support and positioning system has been designed and developed by the Departments of Mechanical Engineering and Surveying of the University of Cape Town to ensure the accurate positioning in the proton beam of the lesion to be treated. The basic components of the system are an adjustable chair, a series of video cameras and two computers. The specifications for the proton therapy interlock system require that the inputs to and the outputs from the system be similar to those of the neutron therapy system. Additional facilities such as a full diagnostic system which would assist the operators in the event of an error will also be provided. Dosimeters are required for beam monitoring, for monitor calibration and for determining dose distributions. Several designs of transmission ionization chambers for beam monitoring have been designed and tested, while several types of ionization chambers and diodes have been used for the dose distribution measurements. To facilitate the comparison of measured ranges and energy losses of proton beams in the various materials with tabled values, simple empirical approximations, which are sufficiently accurate for most applications, have been used. 10 refs., 10 fig., 4 tabs

  13. Proton Pulse Radiolysis

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, H C; Nilsson, G; Reitberger, T; Thuomas, K A

    1973-03-15

    A 5 MeV proton accelerator (Van de Graaff) has been used for pulse radiolysis of a number of organic gases and the transient spectra obtained from the alkanes methane, ethane, propane, n-butane and neopentane have tentatively been assigned to alkyl radicals. Some methodological aspects of this new technique are discussed

  14. The Melbourne proton microprobe

    International Nuclear Information System (INIS)

    Legge, G.J.F.; McKenzie, C.D.; Mazzolini, A.P.

    1979-01-01

    A scanning proton microprobe is described which operates in ultra-high vacuum with a resolution of ten microns. The operating principles and main features of the design are discussed and the ability of such an instrument to detect trace elements down to a few ppm by mass is illustrated

  15. Proton microanalysis in plants

    International Nuclear Information System (INIS)

    Garrec, J.P.

    Micro-analyses by nuclear reactions and atomic excitation are used to determine the distribution of fluorine and calcium in the needles of Abies Alba. Fluorine is detected by the nuclear reaction 19 F(p,α) 16 O at the 1.35 MeV resonance. Calcium is measured by its characteristic X-rays due to proton excitation [fr

  16. Making MUSIC: A multiple sampling ionization chamber

    International Nuclear Information System (INIS)

    Shumard, B.; Henderson, D.J.; Rehm, K.E.; Tang, X.D.

    2007-01-01

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction

  17. Making MUSIC: A multiple sampling ionization chamber

    Science.gov (United States)

    Shumard, B.; Henderson, D. J.; Rehm, K. E.; Tang, X. D.

    2007-08-01

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. × 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction.

  18. Making MUSIC: A multiple sampling ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

    2007-08-15

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

  19. Proton transfer events in GFP

    NARCIS (Netherlands)

    Di Donato, M.; van Wilderen, L.J.G.W.; van Stokkum, I.H.M.; Cohen Stuart, T.A.; Kennis, J.T.M.; Hellingwerf, K.J.; van Grondelle, R.; Groot, M.L.

    2011-01-01

    Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton

  20. Handling of Solid Residues

    International Nuclear Information System (INIS)

    Medina Bermudez, Clara Ines

    1999-01-01

    The topic of solid residues is specifically of great interest and concern for the authorities, institutions and community that identify in them a true threat against the human health and the atmosphere in the related with the aesthetic deterioration of the urban centers and of the natural landscape; in the proliferation of vectorial transmitters of illnesses and the effect on the biodiversity. Inside the wide spectrum of topics that they keep relationship with the environmental protection, the inadequate handling of solid residues and residues dangerous squatter an important line in the definition of political and practical environmentally sustainable. The industrial development and the population's growth have originated a continuous increase in the production of solid residues; of equal it forms, their composition day after day is more heterogeneous. The base for the good handling includes the appropriate intervention of the different stages of an integral administration of residues, which include the separation in the source, the gathering, the handling, the use, treatment, final disposition and the institutional organization of the administration. The topic of the dangerous residues generates more expectation. These residues understand from those of pathogen type that are generated in the establishments of health that of hospital attention, until those of combustible, inflammable type, explosive, radio-active, volatile, corrosive, reagent or toxic, associated to numerous industrial processes, common in our countries in development

  1. Dielectric properties of residual water in amorphous lyophilized mixtures of sugar and drug

    Energy Technology Data Exchange (ETDEWEB)

    Moznine, R El [School of Pharmacy, De Montfort University, Leiceste (United Kingdom); Smith, G [School of Pharmacy, De Montfort University, Leicester (United Kingdom); Polygalov, E [School of Pharmacy, De Montfort University, Leicester (United Kingdom); Suherman, P M [School of Pharmacy, De Montfort University, Leicester (United Kingdom); Broadhead, J [AstraZeneca Charnwood R and D, Bakewell Rd, Loughborough (United Kingdom)

    2003-02-21

    Dielectric relaxation spectroscopy was used to investigate the properties of residual water in lyophilized formulations of a proprietary tri-phosphate drug containing a sugar (trehalose, lactose or sucrose) or dextran. The dielectric properties of each formulation were determined in the frequency range (0.1 Hz-0.1 MHz) and temperature range (30 deg. C-T{sub g}). The temperature dependence of the relaxation times for all samples showed Arrhenuis behaviour, from which the activation energy was derived. Proton hopping through the hydrogen-bonded network (clusters) of water molecules was suggested as the principle mode of charge transport. Significant differences in dielectric relaxation kinetics and activation energy were observed for the different formulations, which were found to correlate with the amount of monophosphate degradation product.

  2. Australian national proton facility

    International Nuclear Information System (INIS)

    Jackson, M.

    2000-01-01

    Full text: Proton therapy has been in use since 1954 and over 25,000 patients have been treated worldwide. Until recently most patients were treated at physics research facilities and apart from the Harvard Cyclotron Laboratory and some low energy machines for eye treatment, only small numbers of patients were treated in each centre and conditions were less than optimal. Limited beam time and lack of support facilities restricted the type of patient treated and conventional fractionation could not be used. The initial clinical experience was mainly with small tumours and other lesions close to critical organs. Large numbers of eye tumours have also been treated. Protons have a well-defined role in these situations and are now being used in the treatment of more common cancers. Since the development of hospital-based facilities, such as the one in Loma Linda in California, over 2,500 patients with prostate cancer have been treated using a simple technique which gives results at least as good as radical surgery, external beam radiotherapy or brachytherapy. Importantly, the incidence of severe complications is very low. There are encouraging results in many disease sites including lung, liver, soft tissue sarcomas and oesophagus. As proton therapy becomes more widely available, randomised trials comparing it with conventional radiotherapy or intensity modulated radiotherapy (IMRT) will be possible. In most situations the use of protons will enable a higher dose to be given safely but in situations where local control rates are already satisfactory, protons are expected to produce less complications than conventional treatment. The initial costs of a proton facility are high but the recurrent costs are similar to other forms of high technology radiotherapy. Simple treatment techniques with only a few fields are usually possible and proton therapy avoids the high integral doses associated with IMRT. This reduction in the low dose volume is likely to be particularly

  3. Protonation of pyridine. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Zahran, N F; Ghoniem, H; Helal, A I [Physics Dept., Nuclear Research Center, AEA., Cairo, (Egypt); Rasheed, N [Nuclear Material Authority, Cairo, (Egypt)

    1996-03-01

    Field ionization mass spectra of pyridine is measured using 10{mu}m activated wire. protonation of pyridine, is observed as an intense peak in the mass spectra. Charge distribution of pyridine molecule is calculated using the modified neglect of diatomic overlap (MNDO) technique, and consequently proton attachment is proposed to be on the nitrogen atom. Temperature dependence of (M+H){sup +} ion is investigated and discussed. MNDO calculations of the protonated species are done, and the proton affinity of pyridine molecule is estimated. Time dependence of the field ionization process of pyridine and protonated ions are observed and discussed. 5 figs.

  4. Proton induced luminescence of minerals

    Energy Technology Data Exchange (ETDEWEB)

    Calvo del Castillo, H.; Millan, A.; Calderon, T. [Depto. Geologia y Geoquimica, Universidad Autonoma de Madrid, Ctra. Colmenar, km. 15, 28049, Madrid (Spain); Beneitez, P. [Departamento Quimica Fisica Aplicada, Universidad Autonoma de Madrid Cantoblanco, Madrid (Spain); Ruvalcaba S, J.L. [lFUNAM, Circuito de la lnvestigacion Cientifica s/n, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

    2008-07-01

    This paper presents a summary of Ionoluminescence (IL) for several minerals commonly found in jewellery pieces and/or artefacts of historical interest. Samples including silicates and non-silicates (native elements, halide, oxide, carbonate and phosphate groups) have been excited with a 1.8 MeV proton beam, and IL spectra in the range of 200- 900 nm have been collected for each one using a fiber optic coupled spectrometer. Light emissions have been related to Cr{sup 3+}, Mn{sup 2+} and Pr{sup 3+} ions, as well as intrinsic defects in these minerals. Results show the potential of IL for impurity characterization with high detection limits, local symmetry studies, and the study of the origin of minerals. (Author)

  5. Protonation of caffeine: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami, Hamed [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Tabrizchi, Mahmoud, E-mail: m-tabriz@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Farrokhpour, Hossein [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-03-29

    Highlights: ► Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources. ► Experimental and theoretical evidence was collected to assign the observed peaks to caffeine related ionic species. ► A new concept of “internal proton affinity”, the protonation tendency for each atom in a molecule, was defined. - Abstract: Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources, corona discharge (CD) and UV photoionization. Three peaks were observed in ion mobility spectrum by simultaneously running the two ionization sources. Experimental and theoretical evidence was collected to link the observed peaks to caffeine related ionic species. One peak was attributed to the M{sup +} ion while the other two were assigned to different protonated isomers of caffeine. In the case of CD ionization source, it was observed that different sites of caffeine compete for protonation and their relative intensities, depends on the sample concentration as well as the nature of the reactant ions. The new concept of “internal proton affinity” (IPA) was defined to express the tendency of holding the added proton for each atom in a molecule.

  6. Protonation of caffeine: A theoretical and experimental study

    International Nuclear Information System (INIS)

    Bahrami, Hamed; Tabrizchi, Mahmoud; Farrokhpour, Hossein

    2013-01-01

    Highlights: ► Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources. ► Experimental and theoretical evidence was collected to assign the observed peaks to caffeine related ionic species. ► A new concept of “internal proton affinity”, the protonation tendency for each atom in a molecule, was defined. - Abstract: Protonation of caffeine was examined by ion mobility spectrometry equipped with two ionization sources, corona discharge (CD) and UV photoionization. Three peaks were observed in ion mobility spectrum by simultaneously running the two ionization sources. Experimental and theoretical evidence was collected to link the observed peaks to caffeine related ionic species. One peak was attributed to the M + ion while the other two were assigned to different protonated isomers of caffeine. In the case of CD ionization source, it was observed that different sites of caffeine compete for protonation and their relative intensities, depends on the sample concentration as well as the nature of the reactant ions. The new concept of “internal proton affinity” (IPA) was defined to express the tendency of holding the added proton for each atom in a molecule

  7. Proton transfer events in GFP.

    Science.gov (United States)

    Di Donato, Mariangela; van Wilderen, Luuk J G W; Van Stokkum, Ivo H M; Stuart, Thomas Cohen; Kennis, John T M; Hellingwerf, Klaas J; van Grondelle, Rienk; Groot, Marie Louise

    2011-09-28

    Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton transfer through a 'proton-wire', formed by the chromophore (the proton donor), water molecule W22, Ser205 and Glu222 (the acceptor), on a picosecond time scale. To obtain a more refined view of this process, we have used a combined approach of time resolved mid-infrared spectroscopy and visible pump-dump-probe spectroscopy to resolve with atomic resolution how and how fast protons move through this wire. Our results indicate that absorption of light by GFP induces in 3 ps (10 ps in D(2)O) a shift of the equilibrium positions of all protons in the H-bonded network, leading to a partial protonation of Glu222 and to a so-called low barrier hydrogen bond (LBHB) for the chromophore's proton, giving rise to dual emission at 475 and 508 nm. This state is followed by a repositioning of the protons on the wire in 10 ps (80 ps in D(2)O), ultimately forming the fully deprotonated chromophore and protonated Glu222.

  8. Solar proton fluxes since 1956

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1977-01-01

    The fluxes of protons emitted during solar flares since 1956 were evaluated. The depth-versus-activity profiles of 56 Co in several lunar rocks are consistent with the solar-proton fluxes detected by experiments on several satellites. Only about 20% of the solar-proton-induced activities of 22 Na and 55 Fe in lunar rocks from early Apollo missions were produced by protons emitted from the sun during solar cycle 20 (1965--1975). The depth-versus-activity data for these radionuclides in several lunar rocks were used to determine the fluxes of protons during solar cycle 19 (1954--1964). The average proton fluxes for cycle 19 are about five times those for both the last million years and for cycle 20. These solar-proton flux variations correlate with changes in sunspot activity

  9. AN INVESTIGATION OF THE PROTONATION STATES OF HUMAN LACTOFERRIN IRON-BINDING PROTEIN

    Directory of Open Access Journals (Sweden)

    Lilia Anghel

    2015-06-01

    Full Text Available In this study, the protonation states of ionizable groups of human lactoferrin in various conformations were investigated theoretically, at physiological pH (7.365. These calculations show that the transition of the protein from a conformation to another one is accompanied by changes in the protonation state of specific amino acid residues. Analysis of the pKa calculatons underlined the importance of participation of two arginines and one lysine in the opening / closing of the protein. In addition, it was found that the mechanism of iron release depends on the protonation state of TYR-192. Protonated state of this residue in the closed form of lactoferrin will trigger the opening of protein and release of iron ions.

  10. Proton mass decomposition

    Science.gov (United States)

    Yang, Yi-Bo; Chen, Ying; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2018-03-01

    We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of Nf = 2 + 1 DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop pertur-bative calculation and proper normalization of the glue operator, we find that the u, d, and s quark masses contribute 9(2)% to the proton mass. The quark energy and glue field energy contribute 31(5)% and 37(5)% respectively in the MS scheme at µ = 2 GeV. The trace anomaly gives the remaining 23(1)% contribution. The u, d, s and glue momentum fractions in the MS scheme are consistent with the global analysis at µ = 2 GeV.

  11. Proton solar flares

    International Nuclear Information System (INIS)

    Shaposhnikova, E.F.

    1979-01-01

    The observations of proton solar flares have been carried out in 1950-1958 using the extrablackout coronograph of the Crimea astrophysical observatory. The experiments permit to determine two characteristic features of flares: the directed motion of plasma injection flux from the solar depths and the appearance of a shock wave moving from the place of the injection along the solar surface. The appearance of the shock wave is accompanied by some phenomena occuring both in the sunspot zone and out of it. The consistent flash of proton flares in the other groups of spots, the disappearance of fibres and the appearance of eruptive prominences is accomplished in the sunspot zone. Beyond the sunspot zone the flares occur above spots, the fibres disintegrate partially or completely and the eruptive prominences appear in the regions close to the pole

  12. The Amsterdam proton microbeam

    International Nuclear Information System (INIS)

    Bos, A.J.J.

    1984-01-01

    The aim of the work presented in this thesis is to develop a microbeam setup such that small beam spot sizes can be produced routinely, and to investigate the capabilities of the setup for micro-PIXE analysis. The development and performance of the Amsterdam proton microbeam setup are described. The capabilities of the setup for micro-PIXE are shown with an investigation into the presence of trace elements in human hair. (Auth.)

  13. Analysis of protein content in grain by proton activation

    International Nuclear Information System (INIS)

    Dohan, D.A.; Standing, K.G.

    1976-01-01

    The total protein content of grain is an important measure of its nutritional value. More than one million protein analyses are carried out each year in Canada alone. The traditional method of measurement has been the Kjeldahl chemical technique, which measures total nitrogen. A new method of protein analysis which also measures total nitrogen has been developed. A beam of 16 MeV protons strikes a sample of grain and produces radioactive 14 0 nuclei through the reaction 14 N(p,n) 14 0. The effective sample thickness is determined by the proton range. The 14 0 decay (tausub(1/2)=71sec) is detected off-line by its characteristic 2.31 MeV γ-ray. The total number of protons hitting the sample is measured by integrating the beam current. The ratio of the number of γ-rays counted to the total number of protons striking the sample determines the abundance of nitrogen. The measurement is unambiguous, since no other reaction can produce 14 0 at 16 MeV proton energy. A mechanized system for sample handling has been constructed. Samples are carried into the irradiation area on a conveyor belt, then back through a shielding wall into a counting area. The laboratory PDP 15/40 computer controls the entire operation. At present the system is being tested at a rate of about two samples per minute. (author)

  14. Proton implantation effect on (SUS-316) stainless steel

    International Nuclear Information System (INIS)

    Das, A.K.; Ishigami, R.; Kamal, I.

    2015-01-01

    Microstructural damage and nano hardness of the industrial grade stainless steel (SUS-316) have been studied under proton (H + ) implanted condition applying different doses at room temperature. The implantation scheme such as proton energy, fluence, irradiation time, and penetration depth in the target materials were estimated by Monte Carlo Simulation Code SRIM-2008. In the simulation, the parameters were chosen in such a way that the damage density (displacement per atom or dpa) would be uniform up to certain depth from the surface. X-ray diffraction study of the annealed samples prior to the proton implantation showed the austenitic fcc structure and no significant change was observed after proton implantation in it. Microstructural observation made by Scanning Transmission Electron Microscopy (STEM) revealed that 1 dpa of proton-irradiation induced the structural damage extended up to 1 μm depth from the surface. The nano hardness study showed that the hardness level of the irradiated samples increased monotonically with the irradiation doses. Proton dose of 1 dpa caused 65% increment of hardness level on average in case of uniformly irradiated samples. It was realized that the increment of hardness was a consequence of microstructural damages caused by the formation of interstitial dislocation loops in the sample matrix keeping the lattice structure unaffected

  15. Proton microprobe analysis of zinc in skeletal tissues. [Proton induced x-ray emission analysis

    Energy Technology Data Exchange (ETDEWEB)

    Doty, S B; Jones, K W; Kraner, H W; Shroy, R E; Hanson, A L

    1980-06-01

    A proton microprobe with windowless exit port was used to study zinc distributions in various types of skeletal tissues. The use of an external beam facilitated positioning of the targets for examination of particular points of interest. The proton microprobe is uniquely suited to this work since it combines high sensitivity for zinc determinations in thick samples with good spatial resolution. Measurements on rat and rabbit Achilles tendon showed a significant increase in zinc concentrations as the beam moved from the unmineralized collagen into the mineralized attachment site. Cartilage gave a similar result, with calcified cartilage having a greater zinc level than the articular surface on unmineralized epiphyseal cartilage.

  16. The proton radius puzzle

    Science.gov (United States)

    Bonesini, Maurizio

    2017-12-01

    The FAMU (Fisica degli Atomi Muonici) experiment has the goal to measure precisely the proton Zemach radius, thus contributing to the solution of the so-called proton radius "puzzle". To this aim, it makes use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target with an high-Z gas admixture and a tunable mid-IR high power laser, to measure the hyperfine (HFS) splitting of the 1S state of the muonic hydrogen. From the value of the exciting laser frequency, the energy of the HFS transition may be derived with high precision ( 10-5) and thus, via QED calculations, the Zemach radius of the proton. The experimental apparatus includes a precise fiber-SiPMT beam hodoscope and a crown of eight LaBr3 crystals and a few HPGe detectors for detection of the emitted characteristic X-rays. Preliminary runs to optimize the gas target filling and its operating conditions have been taken in 2014 and 2015-2016. The final run, with the pump laser to drive the HFS transition, is expected in 2018.

  17. Heavy quarks in proton

    CERN Document Server

    AUTHOR|(SzGeCERN)655637

    The measurement of prompt photon associated with a b jet in proton-proton interactions can provide us insight into the inner structure of proton. This is because precision of determination of parton distribution functions of b quark and gluon can be increased by such a measurement. The measurement of cross-section of prompt photon associated with a b jet (process $pp\\longrightarrow \\gamma + b + X$) at $\\sqrt{s}$= 8 TeV with the ATLAS detector is presented. Full 8 TeV dataset collected by ATLAS during the year 2012 was used in this analysis. Corresponding integrated luminosity is 20.3 $fb^{-1}$. Fiducial differential cross-section as a function of photon transverse momentum at particle level was extracted from data and compared with the prediction of leading order event generator Pythia 8. Cross-section extracted from data is normalised independently on the Monte Carlo prediction. Values of data distribution lie above Monte Carlo values. The difference can be explained by presence of higher order effects not ...

  18. An imaging proton spectrometer for short-pulse laser plasma experiments

    International Nuclear Information System (INIS)

    Chen Hui; Hazi, A. U.; Maren, R. van; Chen, S. N.; Le Pape, S.; Rygg, J. R.; Shepherd, R.; Fuchs, J.; Gauthier, M.

    2010-01-01

    The ultraintense short pulse laser pulses incident on solid targets can generate energetic protons. In addition to their potentially important applications such as in cancer treatments and proton fast ignition, these protons are essential to understand the complex physics of intense laser plasma interaction. To better characterize these laser-produced protons, we designed and constructed a novel spectrometer that will not only measure proton energy distribution with high resolution but also provide its angular characteristics. The information obtained from this spectrometer compliments those from commonly used diagnostics including radiochromic film packs, CR39 nuclear track detectors, and nonimaging magnetic spectrometers. The basic characterizations and sample data from this instrument are presented.

  19. An imaging proton spectrometer for short-pulse laser plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hui; Hazi, A. U.; Maren, R. van; Chen, S. N.; Le Pape, S.; Rygg, J. R.; Shepherd, R. [Lawrence Livermore National Laboratory, Livemore, California 94551 (United States); Fuchs, J.; Gauthier, M. [LULI Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2010-10-15

    The ultraintense short pulse laser pulses incident on solid targets can generate energetic protons. In addition to their potentially important applications such as in cancer treatments and proton fast ignition, these protons are essential to understand the complex physics of intense laser plasma interaction. To better characterize these laser-produced protons, we designed and constructed a novel spectrometer that will not only measure proton energy distribution with high resolution but also provide its angular characteristics. The information obtained from this spectrometer compliments those from commonly used diagnostics including radiochromic film packs, CR39 nuclear track detectors, and nonimaging magnetic spectrometers. The basic characterizations and sample data from this instrument are presented.

  20. Modification of polycrystalline copper by proton irradiation; Modificacion de cobre policristalino por irradiacion con protones

    Energy Technology Data Exchange (ETDEWEB)

    Garcia S, F.; Cabral P, A. [Instituto Nacional de Investigaciones Nucleares, Hipodromo Condesa, 06100 Mexico D.F. (Mexico); Saniger B, J.M.; Banuelos, J.G. [UNAM Centro de Instrumentos, Mexico D.F. (Mexico); Barragan V, A. [UNAM Instituto de Fisica, Mexico D.F. (Mexico)

    1997-07-01

    Polished copper samples were irradiated with proton beams of 300 and 700 keV at room temperature and at -150 Centigrade. In this work the obtained results are reported when such copper irradiated samples are analysed with Sem, Tem, AFM. The Sem micrographs showed evident changes in surface of these copper samples, therefore an EDAX microanalysis was done for its characterization. additionally, the Tem micrographs showed heaps formation until 200 nm. Its electron diffraction spectra indicated that these heaps consist of a copper compound. Finally with AFM were observed changes in coloration of the irradiated sample surface, as well as changes in texture and rugosity of them. These results show in general that irradiation process with protons which is known as an innocuo process produces changes in the copper properties. (Author)

  1. DDT residues in sediments from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    in the sediments from the Bay of Bengal. Peterson grab and hydrographic winch was used to collect the sediment samples. Each sample was extracted and cleaned. Residues were detected by electron capture gas chromatography. A range variation in the concentration...

  2. Detecting organic gunpowder residues from handgun use

    Science.gov (United States)

    MacCrehan, William A.; Ricketts, K. Michelle; Baltzersen, Richard A.; Rowe, Walter F.

    1999-02-01

    The gunpowder residues that remain after the use of handguns or improvised explosive devices pose a challenge for the forensic investigator. Can these residues be reliably linked to a specific gunpowder or ammunition? We investigated the possibility by recovering and measuring the composition of organic additives in smokeless powder and its post-firing residues. By determining gunpowder additives such as nitroglycerin, dinitrotoluene, ethyl- and methylcentralite, and diphenylamine, we hope to identify the type of gunpowder in the residues and perhaps to provide evidence of a match to a sample of unfired powder. The gunpowder additives were extracted using an automated technique, pressurized fluid extraction (PFE). The conditions for the quantitative extraction of the additives using neat and solvent-modified supercritical carbon dioxide were investigated. All of the major gunpowder additives can be determined with baseline resolution using capillary electrophoresis (CE) with a micellar agent and UV absorbance detection. A study of candidate internal standards for use in the CE method is also presented. The PFE/CE technique is used to evaluate a new residue sampling protocol--asking shooters to blow their noses. In addition, an initial investigation of the compositional differences among unfired and post-fired .22 handgun residues is presented.

  3. Dielectric properties of proton irradiated PES

    International Nuclear Information System (INIS)

    Shah, Nilam; Singh, N.L.; Singh, K.P.

    2005-01-01

    Polyethersulfone films were irradiated with 3 MeV proton beam at fluences ranging from 10 13 to 10 15 ions/cm 2 . AC electrical properties of irradiated samples were studied in the frequency range 100 Hz to 1MHz by LCR meter. There is an exponential increase in conductivity with frequency but the effect of irradiation is not significant. The dielectric loss/constant are observed to change with fluence. (author)

  4. [Why proton therapy? And how?

    Science.gov (United States)

    Thariat, Juliette; Habrand, Jean Louis; Lesueur, Paul; Chaikh, Abdulhamid; Kammerer, Emmanuel; Lecomte, Delphine; Batalla, Alain; Balosso, Jacques; Tessonnier, Thomas

    2018-03-01

    Proton therapy is a radiotherapy, based on the use of protons, charged subatomic particles that stop at a given depth depending on their initial energy (pristine Bragg peak), avoiding any output beam, unlike the photons used in most of the other modalities of radiotherapy. Proton therapy has been used for 60 years, but has only become ubiquitous in the last decade because of recent major advances in particle accelerator technology. This article reviews the history of clinical implementation of protons, the nature of the technological advances that now allows its expansion at a lower cost. It also addresses the technical and physical specificities of proton therapy and the clinical situations for which proton therapy may be relevant but requires evidence. Different proton therapy techniques are possible. These are explained in terms of their clinical potential by explaining the current terminology (such as cyclotrons, synchrotrons or synchrocyclotrons, using superconducting magnets, fixed line or arm rotary with passive diffusion delivery or active by scanning) in basic words. The requirements associated with proton therapy are increased due to the precision of the depth dose deposit. The learning curve of proton therapy requires that clinical indications be prioritized according to their associated uncertainties (such as range uncertainties and movement in lung tumors). Many clinical indications potentially fall under proton therapy ultimately. Clinical strategies are explained in a paralleled manuscript. Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  5. Range verification for eye proton therapy based on proton-induced x-ray emissions from implanted metal markers

    Science.gov (United States)

    La Rosa, Vanessa; Kacperek, Andrzej; Royle, Gary; Gibson, Adam

    2014-06-01

    Metal fiducial markers are often implanted on the back of the eye before proton therapy to improve target localization and reduce patient setup errors. We aim to detect characteristic x-ray emissions from metal targets during proton therapy to verify the treatment range accuracy. Initially gold was chosen for its biocompatibility properties. Proton-induced x-ray emissions (PIXE) from a 15 mm diameter gold marker were detected at different penetration depths of a 59 MeV proton beam at the CATANA proton facility at INFN-LNS (Italy). The Monte Carlo code Geant4 was used to reproduce the experiment and to investigate the effect of different size markers, materials, and the response to both mono-energetic and fully modulated beams. The intensity of the emitted x-rays decreases with decreasing proton energy and thus decreases with depth. If we assume the range to be the depth at which the dose is reduced to 10% of its maximum value and we define the residual range as the distance between the marker and the range of the beam, then the minimum residual range which can be detected with 95% confidence level is the depth at which the PIXE peak is equal to 1.96 σbkg, which is the standard variation of the background noise. With our system and experimental setup this value is 3 mm, when 20 GyE are delivered to a gold marker of 15 mm diameter. Results from silver are more promising. Even when a 5 mm diameter silver marker is placed at a depth equal to the range, the PIXE peak is 2.1 σbkg. Although these quantitative results are dependent on the experimental setup used in this research study, they demonstrate that the real-time analysis of the PIXE emitted by fiducial metal markers can be used to derive beam range. Further analysis are needed to demonstrate the feasibility of the technique in a clinical setup.

  6. Proton permeation of lipid bilayers.

    Science.gov (United States)

    Deamer, D W

    1987-10-01

    Proton permeation of the lipid bilayer barrier has two unique features. First, permeability coefficients measured at neutral pH ranges are six to seven orders of magnitude greater than expected from knowledge of other monovalent cations. Second, proton conductance across planar lipid bilayers varies at most by a factor of 10 when pH is varied from near 1 to near 11. Two mechanisms have been proposed to account for this anomalous behavior: proton conductance related to contaminants of lipid bilayers, and proton translocation along transient hydrogen-bonded chains (tHBC) of associated water molecules in the membrane. The weight of evidence suggests that trace contaminants may contribute to proton conductance across planar lipid membranes at certain pH ranges, but cannot account for the anomalous proton flux in liposome systems. Two new results will be reported here which were designed to test the tHBC model. These include measurements of relative proton/potassium permeability in the gramicidin channel, and plots of proton flux against the magnitude of pH gradients. (1) The relative permeabilities of protons and potassium through the gramicidin channel, which contains a single strand of hydrogen-bonded water molecules, were found to differ by at least four orders of magnitude when measured at neutral pH ranges. This result demonstrates that a hydrogen-bonded chain of water molecules can provide substantial discrimination between protons and other cations. It was also possible to calculate that if approximately 7% of bilayer water was present in a transient configuration similar to that of the gramicidin channel, it could account for the measured proton flux. (2) The plot of proton conductance against pH gradient across liposome membranes was superlinear, a result that is consistent with one of three alternative tHBC models for proton conductance described by Nagle elsewhere in this volume.

  7. Proton pump inhibitors and gastroenteritis

    International Nuclear Information System (INIS)

    Hassing, Robert-Jan; Verbon, Annelies; Visser, Herman de; Hofman, Albert; Stricker, Bruno H.

    2016-01-01

    An association between proton pump inhibitor (PPI) therapy and bacterial gastroenteritis has been suggested as well as contradicted. The aim of this study was to examine the association between the use of PPIs and occurrence of bacterial gastroenteritis in the prospective Rotterdam Study. The Rotterdam Study is a population-based cohort study among 14,926 subjects aged 45 years and older with up to 24 years of follow-up. Analyses were performed with a generalized estimating equations method in participants who handed-in a diagnostic stool sample. Furthermore, a nested case–control analysis was performed using the total cohort as a reference group. A bacterial microorganism was isolated in 125 samples, whereas 1174 samples were culture negative. In the generalized estimating equations analysis, we found that participants with a bacterial gastroenteritis were more likely than controls to be current users of PPIs (adjusted OR 1.94; 95 % CI 1.15–3.25). Different sensitivity analyses did not change this result. A considerably higher effect was observed (adjusted OR 6.14; 95 % CI 3.81–9.91), using the total cohort as a reference in a nested case–control analysis. Current PPI therapy is associated with an increased risk of bacterial gastroenteritis. However, by reducing the risk of selection and information bias in our study design, we demonstrated that the effect is lower than previously assumed.

  8. Multielement proton activation analysis: application to airborne particulate matter

    International Nuclear Information System (INIS)

    Priest, P.; Devillers, M.; Desaedeleer, G.

    1980-01-01

    Proton activation analysis in the range of 25 to 30 MeV proton energies allows the determination of Na, Mg, Ca, Ti, Fe, Zn, As, Sr, Sn and Pb in airborne particles collected by 4 to 7 stage impactors. Under normal, not limitative irradiation and counting conditions, the determination is accurate for samples collected from 1 to 10 m 3 of air in rural atmospheres

  9. MUSE: Measuring the proton radius with muon-proton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, Jan Christopher [Massachusetts Institute of Technology, Cambridge (United States)

    2014-07-01

    The proton radius has been measured so far using electron-proton scattering, electronic Hydrogen spectroscopy and muonic Hydrogen spectroscopy, the latter producing a much more accurate, but seven sigma different, result, leading to the now famous proton radius puzzle. The MUSE collaboration aims to complete the set of measurements by using muon scattering to determine the proton radius and to shed light on possible explanations of the discrepancy. The talk gives an overview of the experiment motivation and design and a status report on the progress.

  10. Vibrational spectroscopy on protons and deuterons in proton conducting perovskites

    DEFF Research Database (Denmark)

    Glerup, M.; Poulsen, F.W.; Berg, R.W.

    2002-01-01

    A short review of IR-spectroscopy on protons in perovskite structure oxides is given. The nature of possible proton sites, libration and combination tones and degree of hydrogen bonding is emphasised. Three new spectroscopic experiments and/or interpretations are presented. An IR-microscopy exper......A short review of IR-spectroscopy on protons in perovskite structure oxides is given. The nature of possible proton sites, libration and combination tones and degree of hydrogen bonding is emphasised. Three new spectroscopic experiments and/or interpretations are presented. An IR...

  11. Management of NORM Residues

    International Nuclear Information System (INIS)

    2013-06-01

    The IAEA attaches great importance to the dissemination of information that can assist Member States in the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support the nuclear fuel cycle and nuclear applications, and that address the legacy of past practices and accidents. However, radioactive residues are found not only in nuclear fuel cycle activities, but also in a range of other industrial activities, including: - Mining and milling of metalliferous and non-metallic ores; - Production of non-nuclear fuels, including coal, oil and gas; - Extraction and purification of water (e.g. in the generation of geothermal energy, as drinking and industrial process water; in paper and pulp manufacturing processes); - Production of industrial minerals, including phosphate, clay and building materials; - Use of radionuclides, such as thorium, for properties other than their radioactivity. Naturally occurring radioactive material (NORM) may lead to exposures at some stage of these processes and in the use or reuse of products, residues or wastes. Several IAEA publications address NORM issues with a special focus on some of the more relevant industrial operations. This publication attempts to provide guidance on managing residues arising from different NORM type industries, and on pertinent residue management strategies and technologies, to help Member States gain perspectives on the management of NORM residues

  12. Tyrosine and carboxyl protonation changes in the bacteriorhodopsin photocycle. 2. Tyrosine-26 and -64

    International Nuclear Information System (INIS)

    Roepe, P.; Scherrer, P.; Ahl, P.L.; Gupta, S.K.D.; Bogomolni, R.A.; Herzfeld, J.; Rothschild, K.J.

    1987-01-01

    Low-temperature Fourier transform infrared (FTIR) and UV difference spectroscopies combined with selective tyrosine nitration and tyrosine isotopic labeling have been used to investigate the participation of tyrosines-26 and -64 in the bacteriorhodopsin (bR) photocycle. Nitration of Tyr-26 has no detectable effect on the FTIR or UV difference spectra of the BR 570 → K 630 or BR 570 → M 412 transitions. In contrast, nitration of Tyr-64 causes changes in both the FTIR and UV spectra of these transitions. However, this nitration does not alter tyrosine peaks in the FTIR difference spectra which have previously been associated with the protonation of a tyrosinate by K 630 and the deprotonation of a tyrosine by M 412 . Instead, Tyr-64 nitration appears to affect other tyrosine peaks. These results and changes in UV difference spectra upon Tyr-64 nitration are consistent with the deprotonation of Tyr-64 by M 412 as concluded previously. Effects on chromophore vibrations caused by Tyr-64 nitration are unaltered upon reducing the nitrotyrosine to aminotyrosine with sodium dithionite. Finally, nitro-Tyr-64 causes a shift in the frequency of a positive peak at 1739 cm -1 in the BR 570 → M 412 FTIR difference spectrum which reflects the protonation of a carboxyl-containing residue. The shift does not occur for samples containing amino-Tyr-64. These data suggest that Tyr-64 may interact with this carboxyl group

  13. PDMS patterning by proton beam

    International Nuclear Information System (INIS)

    Szilasi, S.Z.; Huszank, R.; Csik, A.; Rajta, I.; Cserhati, C.

    2008-01-01

    Complete text of publication follows. In this paper the poly-(dimethylsiloxane) (PDMS) is introduced as a resist material for proton beam writing. We were looking for a biocompatible micropatternable polymer in which the chemical structure changes significantly due to proton beam exposure making the polymer capable of proton beam writing. PDMS is a commonly used silicon-based organic polymer, optically clear, and generally considered to be inert, non-toxic biocompatible polymer. PDMS is also notably hydrophobic, meaning that water cannot easily penetrate its surface. This property has led extended use of PDMS in microfluidics too. PDMS is a crosslinkable polymer, it acts like a rubbery solid when it is cross-linked. In this state, the polymer does not deform permanently under stress or strain. Up to now the PDMS has been used as a casting or replicating material in microfabrication to form microchannels, micromolding, or creating microstamps, etc. PDMS has not been used as a resist material for direct write techniques. In this work we investigated the surface topography of the irradiated regions of PDMS under and without stress (on the cut surface and on the original fluid surface, respectively). In the samples wherein stress was not developed, noticeable compaction was observed. In case of those samples wherein stress was developed, noticeable swelling occurred. During the irradiation around the actual position of the beam spot we experienced significant swelling that reduced in time. To determine the large scale remaining changes in the surface topography at the cut edges of the samples we used Scanning Electron Microscope (SEM). After numerous profilometer measurements we experienced that the irradiated areas became harder, so the probe could move on it without sinking. The unirradiated areas of the PDMS were so soft, that the probe sank in the medium even with the smallest load (5 x 10 -7 N). Because of this phenomenon the irradiated areas seem to be higher

  14. YAP(Ce) crystal characterization with proton beam up to 60 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Randazzo, N. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy)], E-mail: nunzio.randazzo@ct.infn.it; Sipala, V.; Aiello, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy); Lo Presti, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Cirrone, G.A.P.; Cuttone, G.; Di Rosa, F. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud (Italy)

    2008-02-21

    A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ (http://www.lns.infn.it/CATANA/CATANA)] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application.

  15. YAP(Ce) crystal characterization with proton beam up to 60 MeV

    International Nuclear Information System (INIS)

    Randazzo, N.; Sipala, V.; Aiello, S.; Lo Presti, D.; Cirrone, G.A.P.; Cuttone, G.; Di Rosa, F.

    2008-01-01

    A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ (http://www.lns.infn.it/CATANA/CATANA)] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application

  16. YAP(Ce) crystal characterization with proton beam up to 60 MeV

    Science.gov (United States)

    Randazzo, N.; Sipala, V.; Aiello, S.; Lo Presti, D.; Cirrone, G. A. P.; Cuttone, G.; Di Rosa, F.

    2008-02-01

    A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ http://www.lns.infn.it/CATANA/CATANA] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application.

  17. Measurement of small-angle antiproton-proton and proton-proton elastic scattering at the CERN intersecting storage rings

    NARCIS (Netherlands)

    Amos, N.; Block, M.M.; Bobbink, G.J.; Botje, M.A.J.; Favart, D.; Leroy, C.; Linde, F.; Lipnik, P.; Matheys, J-P.; Miller, D.

    1985-01-01

    Antiproton-proton and proton-proton small-angle elastic scattering was measured for centre-of-mass energies at the CERN Intersectung Storage Rings. In addition, proton-proton elastic scattering was measured at . Using the optical theorem, total cross sections are obtained with an accuracy of about

  18. Effect of a pH Gradient on the Protonation States of Cytochrome c Oxidase: A Continuum Electrostatics Study.

    Science.gov (United States)

    Magalhães, Pedro R; Oliveira, A Sofia F; Campos, Sara R R; Soares, Cláudio M; Baptista, António M

    2017-02-27

    Cytochrome c oxidase (CcO) couples the reduction of dioxygen to water with transmembrane proton pumping, which leads to the generation of an electrochemical gradient. In this study we analyze how one of the components of the electrochemical gradient, the difference in pH across the membrane, or ΔpH, influences the protonation states of residues in CcO. We modified our continuum electrostatics/Monte Carlo (CE/MC) method in order to include the ΔpH and applied it to the study of CcO, in what is, to our best knowledge, the first CE/MC study of CcO in the presence of a pH gradient. The inclusion of a transmembrane pH gradient allows for the identification of residues whose titration behavior depends on the pH on both sides of the membrane. Among the several residues with unusual titration profiles, three are well-known key residues in the proton transfer process of CcO: E286 I , Y288 I , and K362 I . All three residues have been previously identified as being critical for the catalytic or proton pumping functions of CcO. Our results suggest that when the pH gradient increases, these residues may be part of a regulatory mechanism to stem the proton flow.

  19. Fan-beam intensity modulated proton therapy.

    Science.gov (United States)

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-11-01

    falloff of a proton depth-dose distribution was found to provide sufficient control over the dose distribution to meet objectives, even with coarse lateral resolution and channel widths as large as 2 cm. Treatment plans on both phantom and patient data show that dose conformity suffers when treatments are delivered from less than approximately ten angles. Treatment time for a sample prostate delivery is estimated to be on the order of 10 min, and neutron production is estimated to be comparable to that found for existing collimated systems. Fan beam proton therapy is a method of delivering intensity modulated proton therapy which may be employed as an alternative to magnetic scanning systems. A fan beam of protons can be created by a set of quadrupole magnets and modified by a dual-purpose range and intensity modulator. This can be used to deliver inversely planned treatments, with spot intensities optimized to meet user defined dose objectives. Additionally, the ability of a fan beam delivery system to effectively treat multiple beam spots simultaneously may provide advantages as compared to spot scanning deliveries.

  20. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

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

  1. The PIREX proton irradiation facility

    International Nuclear Information System (INIS)

    Victoria, M.

    1995-01-01

    The proton Irradiation Experiment (PIREX) is a materials irradiation facility installed in a beam line of the 590 MeV proton accelerator at the Paul Scherrer Institute. Its main purpose is the testing of candidate materials for fusion reactor components. Protons of this energy produce simultaneously displacement damage and spallation products, amongst them helium and can therefore simulate any possible synergistic effects of damage and helium, that would be produced by the fusion neutrons

  2. The PIREX proton irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Victoria, M. [Association EURATOM, Villigen (Switzerland)

    1995-10-01

    The proton Irradiation Experiment (PIREX) is a materials irradiation facility installed in a beam line of the 590 MeV proton accelerator at the Paul Scherrer Institute. Its main purpose is the testing of candidate materials for fusion reactor components. Protons of this energy produce simultaneously displacement damage and spallation products, amongst them helium and can therefore simulate any possible synergistic effects of damage and helium, that would be produced by the fusion neutrons.

  3. Search for proton decay: introduction

    International Nuclear Information System (INIS)

    Goldhaber, M.

    1984-01-01

    In interpreting contained events observed in various proton decay detectors one can sometimes postulate, though usually not unambiguously, a potential decay mode of the proton, called a candidate. It is called a candidate, because for any individual event it is not possible to exclude the possibility that it is instead due to cosmic ray background, chiefly atmospheric neutrinos. Some consistency checks are proposed which could help establish proton decay, if it does occur in the presently accessible lifetime window

  4. Sea Quarks in the Proton

    Directory of Open Access Journals (Sweden)

    Reimer Paul E

    2016-01-01

    Full Text Available The proton is a composite particle in which the binding force is responsible for the majority of its mass. To understand this structure, the distributions and origins of the quark-antiquark pairs produced by the strong force must be measured. The SeaQuest collaboration is using the Drell-Yan process to elucidate antiquark distributions in the proton and to study their modification when the proton is held within a nucleus.

  5. Nuclear breakup of 17Ne and its two-proton halo structure

    Energy Technology Data Exchange (ETDEWEB)

    Wamers, Felix; Aumann, Thomas [Institut fuer Kernphysik, TU Darmstadt (Germany); Bertulani, Carlos [Texas A and M University-Commerce, Commerce (United States); Chulkov, Leonid; Heil, Michael; Simon, Haik [Kernreaktionen und Nukleare Astrophysik, GSI, Darmstadt (Germany); Marganiec, Justyna [Extreme Matter Institute, GSI, Darmstadt (Germany); JINA, Notre Dame (United States); Plag, Ralf [Kernreaktionen und Nukleare Astrophysik, GSI, Darmstadt (Germany); Goethe Universitaet, Frankfurt am Main (Germany); Collaboration: R3B-Collaboration

    2012-07-01

    {sup 17}Ne is a proton-dripline nucleus that has raised interest in nuclear-structure physics in recent years. As a ({sup 15}O+2p) Borromean 3-body system, it is often considered to be a 2-proton-halo nucleus, yet lacking concluding experimental quantification of structure. We have studied breakup reactions of 500 AMeV {sup 17}Ne secondary beams in inverse kinematics using the R3B-LAND setup at GSI. The foci were on (p,2p) quasi-free scattering on a CH{sub 2} target, and on one-proton-knockout reactions on a carbon target. Recoil protons have been detected with Si-Strip detectors and a surrounding 4{pi} NaI spectrometer. Furthermore, projectile-like forward protons after one-proton knockout from {sup 17}Ne have been measured in coincidence with the {sup 15}O residual core. The resulting relative-energy spectrum of the unbound {sup 16}F, as well as proton-removal cross sections with CH{sub 2} and C targets, and the transverse-momentum distributions of the residual fragments are presented. Conclusions on the ground-state structure of {sup 17}Ne are discussed.

  6. CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography

    International Nuclear Information System (INIS)

    Esposito, M.; Waltham, C.; Allinson, N.M.; Anaxagoras, T.; Evans, P.M.; Poludniowski, G.; Green, S.; Parker, D.J.; Price, T.; Manolopoulos, S.; Nieto-Camero, J.

    2015-01-01

    Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs

  7. CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography.

    Science.gov (United States)

    Esposito, M; Anaxagoras, T; Evans, P M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Poludniowski, G; Price, T; Waltham, C; Allinson, N M

    2015-06-03

    Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs.

  8. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A N; Webster, G A [Imperial College, London (United Kingdom); Webster, P J [Salford Univ. (United Kingdom)

    1997-04-01

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  9. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-01-01

    Female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was 7 years after exposure. The doses and energies of the radiation received were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event, leading to the conclusion that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crewmembers

  10. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Duchazeaubeneix, J.C.; Faivre, J.C.; Garreta, D.

    1982-10-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: direct 3- dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore, it is a well adapted method to gating techniques allowing the radiography of fast periodic moving systems. Results obtained on different objects (light and heavy materials) are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiography faster and to get a practical method are discussed

  11. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Saudinos, J.

    1982-04-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: 3-dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore the nuclear scattering radiography (NSR) is a well adapted method to gating techniques allowing the radiography of fast periodic moving objects. Results obtained on phantoms, formalin fixed head and moving object are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiograph faster and to get a practical method are discussed

  12. Proton relativistic model

    International Nuclear Information System (INIS)

    Araujo, Wilson Roberto Barbosa de

    1995-01-01

    In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author)

  13. Ex vivo validation of a stoichiometric dual energy CT proton stopping power ratio calibration

    Science.gov (United States)

    Xie, Yunhe; Ainsley, Christopher; Yin, Lingshu; Zou, Wei; McDonough, James; Solberg, Timothy D.; Lin, Alexander; Teo, Boon-Keng Kevin

    2018-03-01

    A major source of uncertainty in proton therapy is the conversion of Hounsfield unit (HU) to proton stopping power ratio relative to water (SPR). In this study, we measured and quantified the accuracy of a stoichiometric dual energy CT (DECT) SPR calibration. We applied a stoichiometric DECT calibration method to derive the SPR using CT images acquired sequentially at 80 kVp and 140 kVp . The dual energy index was derived based on the HUs of the paired spectral images and used to calculate the effective atomic number (Z eff), relative electron density ({{ρ }e} ), and SPRs of phantom and biological materials. Two methods were used to verify the derived SPRs. The first method measured the sample’s water equivalent thicknesses to deduce the SPRs using a multi-layer ion chamber (MLIC) device. The second method utilized Gafchromic EBT3 film to directly compare relative ranges between sample and water after proton pencil beam irradiation. Ex vivo validation was performed using five different types of frozen animal tissues with the MLIC and three types of fresh animal tissues using film. In addition, the residual ranges recorded on the film were used to compare with those from the treatment planning system using both DECT and SECT derived SPRs. Bland-Altman analysis indicates that the differences between DECT and SPR measurement of tissue surrogates, frozen and fresh animal tissues has a mean of 0.07% and standard deviation of 0.58% compared to 0.55% and 1.94% respectively for single energy CT (SECT) and SPR measurement. Our ex vivo study indicates that the stoichiometric DECT SPR calibration method has the potential to be more accurate than SECT calibration under ideal conditions although beam hardening effects and other image artifacts may increase this uncertainty.

  14. Feasibility of proton-activated implantable markers for proton range verification using PET

    Science.gov (United States)

    Cho, Jongmin; Ibbott, Geoffrey; Gillin, Michael; Gonzalez-Lepera, Carlos; Titt, Uwe; Paganetti, Harald; Kerr, Matthew; Mawlawi, Osama

    2013-11-01

    Proton beam range verification using positron emission tomography (PET) currently relies on proton activation of tissue, the products of which decay with a short half-life and necessitate an on-site PET scanner. Tissue activation is, however, negligible near the distal dose fall-off region of the proton beam range due to their high interaction energy thresholds. Therefore Monte Carlo simulation is often supplemented for comparison with measurement; however, this also may be associated with systematic and statistical uncertainties. Therefore, we sought to test the feasibility of using long-lived proton-activated external materials that are inserted or infused into the target volume for more accurate proton beam range verification that could be performed at an off-site PET scanner. We irradiated samples of ≥98% 18O-enriched water, natural Cu foils, and >97% 68Zn-enriched foils as candidate materials, along with samples of tissue-equivalent materials including 16O water, heptane (C7H16), and polycarbonate (C16H14O3)n, at four depths (ranging from 100% to 3% of center of modulation (COM) dose) along the distal fall-off of a modulated 160 MeV proton beam. Samples were irradiated either directly or after being embedded in Plastic Water® or balsa wood. We then measured the activity of the samples using PET imaging for 20 or 30 min after various delay times. Measured activities of candidate materials were up to 100 times greater than those of the tissue-equivalent materials at the four distal dose fall-off depths. The differences between candidate materials and tissue-equivalent materials became more apparent after longer delays between irradiation and PET imaging, due to the longer half-lives of the candidate materials. Furthermore, the activation of the candidate materials closely mimicked the distal dose fall-off with offsets of 1 to 2 mm. Also, signals from the foils were clearly visible compared to the background from the activated Plastic Water® and balsa wood

  15. Agrochemical residues in rivers sediments, Poas, Costa Rica

    International Nuclear Information System (INIS)

    Masis, Federico; Valdez, Juan; Leon, Sandra; Coto, Tatiana

    2008-01-01

    The organophosphorus and organochlorine agrochemical residues distribution in sediments of 3 rivers located in an ornamental plant production area were analyzed in Poas canton, Alajuela, Costa Rica. The study comprised 8 months in order to assure 3 seasonal episodes: dry, transitional, and rainy seasons. Sediments were taken in 10 sampling stations along the rivers and characterized by a determination of their organic matter and texture. In 7 out of 10 sampling stations pesticide residues were detected in at least 1 of 4 samplings, but quantified only in 4 stations. Agrochemical residues evaluated included 21 organophosphorus and organochlorine pesticides; however, we found residues of only 3 organochlorine pesticides, due their high persistence in the sediment. Residues corresponded to PCNB (80-800 μg.kg -1 ), Endosulfan-β (40-50 μg.kg -1 ), and Endosulfan-α (90 μg.kg -1 ). Chlorothalonil was detected in only one sample. (author) [es

  16. Proton-proton bremsstrahlung towards the elastic limit

    Science.gov (United States)

    Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacelar, J. C. S.; Castelijns, R.; Ermisch, K.; van Garderen, E.; Gašparić, I.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.

    2005-05-01

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed.

  17. Proton-proton bremsstrahlung towards the elastic limit

    International Nuclear Information System (INIS)

    Mahjour-Shafiei, M.; Amir-Ahmadi, H.R.; Bacelar, J.C.S.; Castelijns, R.; Ermisch, K.; Garderen, E. van; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Loehner, H.; Gasparic, I.

    2005-01-01

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed

  18. Designing with residual materials

    NARCIS (Netherlands)

    Walhout, W.; Wever, R.; Blom, E.; Addink-Dölle, L.; Tempelman, E.

    2013-01-01

    Many entrepreneurial businesses have attempted to create value based on the residual material streams of third parties. Based on ‘waste’ materials they designed products, around which they built their company. Such activities have the potential to yield sustainable products. Many of such companies

  19. Improved proton computed tomography by dual modality image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, David C., E-mail: dch@ki.au.dk; Bassler, Niels [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark); Petersen, Jørgen Breede Baltzer [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark); Sørensen, Thomas Sangild [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)

    2014-03-15

    Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65 linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91 linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360

  20. Improved proton computed tomography by dual modality image reconstruction

    International Nuclear Information System (INIS)

    Hansen, David C.; Bassler, Niels; Petersen, Jørgen Breede Baltzer; Sørensen, Thomas Sangild

    2014-01-01

    Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65 linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91 linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360

  1. The FAIR proton linac

    International Nuclear Information System (INIS)

    Kester, O.

    2015-01-01

    FAIR - the Facility for Antiproton and Ion Research in Europe - constructed at GSI in Darmstadt comprises an international centre of heavy ion accelerators that will drive heavy ion and antimatter research. FAIR will provide worldwide unique accelerator and experimental facilities, allowing a large variety of fore-front research in physics and applied science. FAIR will deliver antiproton and ion beams of unprecedented intensities and qualities. The main part of the FAIR facility is a sophisticated accelerator system, which delivers beams to different experiments of the FAIR experimental collaborations - APPA, NuSTAR, CBM and PANDA - in parallel. Modern H-type cavities offer highest shunt impedances of resonant structures of heavy ion linacs at low beam energies < 20 MeV/u and enable the acceleration of intense proton and ion beams. One example is the interdigital H-type structure. The crossed-bar H-cavities extend these properties to high energies even beyond 100 MeV/u. Compared to conventional Alvarez cavities, these crossed-bar (CH) cavities feature much higher shunt impedance at low energies. The design of the proton linac is based on those cavities

  2. Berkeley Proton Linear Accelerator

    Science.gov (United States)

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  3. Ensemble Kalman filtering with residual nudging

    KAUST Repository

    Luo, X.

    2012-10-03

    Covariance inflation and localisation are two important techniques that are used to improve the performance of the ensemble Kalman filter (EnKF) by (in effect) adjusting the sample covariances of the estimates in the state space. In this work, an additional auxiliary technique, called residual nudging, is proposed to monitor and, if necessary, adjust the residual norms of state estimates in the observation space. In an EnKF with residual nudging, if the residual norm of an analysis is larger than a pre-specified value, then the analysis is replaced by a new one whose residual norm is no larger than a pre-specified value. Otherwise, the analysis is considered as a reasonable estimate and no change is made. A rule for choosing the pre-specified value is suggested. Based on this rule, the corresponding new state estimates are explicitly derived in case of linear observations. Numerical experiments in the 40-dimensional Lorenz 96 model show that introducing residual nudging to an EnKF may improve its accuracy and/or enhance its stability against filter divergence, especially in the small ensemble scenario.

  4. Ensemble Kalman filtering with residual nudging

    Directory of Open Access Journals (Sweden)

    Xiaodong Luo

    2012-10-01

    Full Text Available Covariance inflation and localisation are two important techniques that are used to improve the performance of the ensemble Kalman filter (EnKF by (in effect adjusting the sample covariances of the estimates in the state space. In this work, an additional auxiliary technique, called residual nudging, is proposed to monitor and, if necessary, adjust the residual norms of state estimates in the observation space. In an EnKF with residual nudging, if the residual norm of an analysis is larger than a pre-specified value, then the analysis is replaced by a new one whose residual norm is no larger than a pre-specified value. Otherwise, the analysis is considered as a reasonable estimate and no change is made. A rule for choosing the pre-specified value is suggested. Based on this rule, the corresponding new state estimates are explicitly derived in case of linear observations. Numerical experiments in the 40-dimensional Lorenz 96 model show that introducing residual nudging to an EnKF may improve its accuracy and/or enhance its stability against filter divergence, especially in the small ensemble scenario.

  5. The method for measuring residual stress in stainless steel pipes

    International Nuclear Information System (INIS)

    Shimov, Georgy; Rozenbaum, Mikhail; Serebryakov, Alexandr; Serebryakov, Andrey

    2016-01-01

    The main reason of appearance and growth of corrosion damages of the nuclear steam generator heat exchanger tubes is the process of stress-corrosion cracking of metal under the influence of residual tensile stress. Methods used in the production for estimating residual stresses (such as a method of ring samples) allow measuring only the average tangential stress of the pipe wall. The method of ring samples does not allow to assess the level of residual stress in the surface layer of the pipe. This paper describes an experimental method for measuring the residual stresses on the pipe surface by etching a thin surface layer of the metal. The construction and working principle of a trial installation are described. The residual stresses in the wall of the tubes 16 × 1.5 mm (steel AISI 321) for nuclear steam generators is calculated. Keywords: heat exchange pipes, stress corrosion cracking, residual stresses, stress distribution, stress measurement.

  6. Characterization of residual oils for biodiesel production

    Directory of Open Access Journals (Sweden)

    Edmilson Antonio Canesin

    2014-01-01

    Conclusions: The obtained results suggesting that it is possible to take advantage of these residues for biodiesel production as the obtained products were approved according to the rules established by the National Association of Petroleum (ANP; the bovine samples were the exception regarding moisture and acidity.

  7. QA/QC in pesticide residue analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ambrus, A [Agrochemicals Unit, Agency' s Laboratories, Seibersdorf (Austria)

    2002-07-01

    This paper outlines problems related to pesticide residue analysis in a regulatory laboratory that are related to: availability of reference materials, as over 1000 pesticide active ingredients are currently in use and over 400 crops represent a large part of a healthy diet; analysis time; availability of samples in sufficient numbers; uncertainties of the procedures.

  8. QA/QC in pesticide residue analysis

    International Nuclear Information System (INIS)

    Ambrus, A.

    2002-01-01

    This paper outlines problems related to pesticide residue analysis in a regulatory laboratory that are related to: availability of reference materials, as over 1000 pesticide active ingredients are currently in use and over 400 crops represent a large part of a healthy diet; analysis time; availability of samples in sufficient numbers; uncertainties of the procedures

  9. Proton-/sup 90/Zr interaction at sub-Coulomb proton energies

    International Nuclear Information System (INIS)

    Laird, C.E.; Flynn, D.; Hershberger, R.L.; Gabbard, F.

    1987-01-01

    The proton-/sup 90/Zr interaction at sub-Coulomb energies has been investigated in the context of the Lane model, with isospin coupling included, and with alternate decay modes represented with the Hauser-Feshbach model. Scattering and reaction cross sections were accurately measured in order to obtain enough information to constrain the real and absorptive parts of the proton potential. Differential elastic scattering excitation functions were measured at back angles of 135 0 and 165 0 from 2 to 7 MeV, with cross section accuracies of 3%. The energy range was sufficient to go from a region where the backscattering was predominantly Coulomb, enabling additional checks on the cross section accuracies, to a region where the gross structure of the cross sections deviated significantly from Rutherford scattering. Radiative capture cross sections were measured from 1.9 to 5.7 MeV proton energies. The capture cross sections were obtained by summing the measured cross sections for the first two primary gamma rays in addition to some 34 other transitions which terminated on the ground and first excited state. The total inelastic scattering cross section to all /sup 90/Zr excited states (except the first excited state which has been previously measured) was measured at several energies between 3.9 and 5.7 MeV by observing the radiative decay of the residual, excited /sup 90/Zr nuclei. The analysis yielded several model parameters suggestive of large nuclear structure effects. The depth of the absorptive potential was found to vary as W/sub D/ = 2.73+0.70 E/sub p/ in the 2 to 7 MeV proton energy range studied. A real diffuseness of 0.54 fm, significantly smaller than that obtained in neighboring nuclei, was obtained

  10. Construction and test of a polarized proton target

    International Nuclear Information System (INIS)

    Aures, R.

    1983-12-01

    This work describes experiments in which for the first time a proton target has been constructed which is polarized by the ''brute-force'' method. This method requires very low temperatures and high magnetic fields. The low temperatures (down to 10 mK) are obtained by a 3 He/ 4 He dilution refrigerator, the magnetic field (up to 9 T) is produced by a superconducting split pair magnet. The proton target has a volume of about 18 cm 3 and consists of pressed titaniumhydride powder, which has a titanium/-hydrogen ratio of 1:1,96. The hydrogen content is 1,3 mol. Titaniumhydride has the advantage of sufficient heat conductivity at low temperatures and a very high proton density. The heat conductivity of the sample is measured, with and without the presence of a magnetic field. Thermodynamical measurements and adiabatic demagnetisation experiments proved quantitatively the polarization of the protons. The polarization of the proton has been measured in a transmission experiment using polarized neutrons of 1.2 MeV. The result shows a good agreement of theoretical and actual polarization. From the results it can be concluded, that this sample can be used successfully as a polarized proton target for neutron scattering experiments to measure spin-correlations. (orig.) [de

  11. Drug and chemical residues in domestic animals.

    Science.gov (United States)

    Mussman, H C

    1975-02-01

    Given the large number of chemical substances that may find their way into the food supply, a system is needed to monitor their presence. The U. S. Department of Agriculture's Meat and Poultry Inspection Program routinely tests for chemical residues in animals coming to slaughter. Pesticides, heavy metals, growth promotants (hormones and hormonelike agents), and antibiotics are included. Samples are taken statistically so that inferences as to national incidence of residues can be drawn. When a problem is identified, a more selective sampling is designed to help follow up on the initial regulatory action. In testing for pesticides, only DDT and dieldrin are found with any frequency and their levels are decreasing; violative residues of any chlorinated hydrocarbon are generally a result of an industrial accident rather than agricultural usage. Analyses for heavy metals have revealed detectable levels of mercury, lead, and others, but none at levels that are considered a health hazard. Of the hormone or hormonelike substances, only diethylstilbestrol has been a residue problem and its future is uncertain. The most extensive monitoring for veterinary drugs is on the antimicrobials, including sulfonamides, streptomycin, and the tetracycline group of antibiotics that constitute the bulk of the violations; their simultaneous use prophylactically and therapeutically has contributed to the problem in certain cases. A strong, well-designed user education program on proper application of pesticides, chemicals, and veterinary drugs appears to be one method of reducing the incidence of unwanted residues.

  12. Natural radioactivity in petroleum residues

    International Nuclear Information System (INIS)

    Gazineu, M.H.P.; Gazineu, M.H.P.; Hazin, C.A.; Hazin, C.A.

    2006-01-01

    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the 238 U and 232 Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of 226 Ra, 228 Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for 226 Ra, 228 Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for 226 Ra, 40.5 to 1,550.0 kBq/kg for 228 Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  13. Investigation of the utility of selective methyl protonation for determination of membrane protein structures

    International Nuclear Information System (INIS)

    Shih, Steve C. C.; Stoica, Ileana; Goto, Natalie K.

    2008-01-01

    Polytopic α-helical membrane proteins present one of the final frontiers for protein structural biology, with significant challenges causing severe under-representation in the protein structure databank. However, with the advent of hardware and methodology geared to the study of large molecular weight complexes, solution NMR is being increasingly considered as a tool for structural studies of these types of membrane proteins. One method that has the potential to facilitate these studies utilizes uniformly deuterated samples with protons reintroduced at one or two methyl groups of leucine, valine and isoleucine. In this work we demonstrate that in spite of the increased proportion of these amino acids in membrane proteins, the quality of structures that can be obtained from this strategy is similar to that obtained for all α-helical water soluble proteins. This is partly attributed to the observation that NOEs between residues within the transmembrane helix did not have an impact on structure quality. Instead the most important factors controlling structure accuracy were the strength of dihedral angle restraints imposed and the number of unique inter-helical pairs of residues constrained by NOEs. Overall these results suggest that the most accurate structures will arise from accurate identification of helical segments and utilization of inter-helical distance restraints from various sources to maximize the distribution of long-range restraints

  14. Gold processing residue from Jacobina Basin: chemical and physical properties

    OpenAIRE

    Lima, Luiz Rogério Pinho de Andrade; Bernardez, Letícia Alonso; Barbosa, Luís Alberto Dantas

    2007-01-01

    p. 848-852 Gold processing residues or tailings are found in several areas in the Itapicuru River region (Bahia, Brazil), and previous studies indicated significant heavy metals content in the river sediments. The present work focused on an artisanal gold processing residue found in a site from this region. Samples were taken from the processing residue heaps and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron...

  15. 14 MeV proton activation analysis

    International Nuclear Information System (INIS)

    Constantinescu, B.; Ivanov, E.; Plostinaru, D.; Popa-Nemoiu, A.; Pascovichi, G.

    1985-01-01

    A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14 N (p,n) 14 O, (Tsub(1/2)=71 s). The 14 O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)

  16. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  17. Polarized proton collider at RHIC

    International Nuclear Information System (INIS)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N.

    2003-01-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

  18. Protonic decay of oriented nuclei

    International Nuclear Information System (INIS)

    Kadmensky, S.G.

    2002-01-01

    On the basis of the multiparticle theory of protonic decay, the angular distributions of protons emitted by oriented spherical and deformed nuclei in the laboratory frame and in the internal coordinate frame of deformed parent nuclei are constructed with allowance for symmetry with respect to time inversion. It is shown that, because of the deep-subbarrier character of protonic decay, the adiabatic approximation is not applicable to describing the angular distributions of protons emitted by oriented deformed nuclei and that the angular distribution of protons in the laboratory frame does not coincide with that in the internal coordinate frame. It is demonstrated that these angular distributions coincide only if the adiabatic and the semiclassical approximation are simultaneously valid

  19. Direct determination of protonation states and visualization of hydrogen bonding in a glycoside hydrolase with neutron crystallography

    Science.gov (United States)

    Wan, Qun; Parks, Jerry M.; Hanson, B. Leif; Fisher, Suzanne Zoe; Ostermann, Andreas; Schrader, Tobias E.; Graham, David E.; Coates, Leighton; Langan, Paul; Kovalevsky, Andrey

    2015-01-01

    Glycoside hydrolase (GH) enzymes apply acid/base chemistry to catalyze the decomposition of complex carbohydrates. These ubiquitous enzymes accept protons from solvent and donate them to substrates at close to neutral pH by modulating the pKa values of key side chains during catalysis. However, it is not known how the catalytic acid residue acquires a proton and transfers it efficiently to the substrate. To better understand GH chemistry, we used macromolecular neutron crystallography to directly determine protonation and ionization states of the active site residues of a family 11 GH at multiple pD (pD = pH + 0.4) values. The general acid glutamate (Glu) cycles between two conformations, upward and downward, but is protonated only in the downward orientation. We performed continuum electrostatics calculations to estimate the pKa values of the catalytic Glu residues in both the apo- and substrate-bound states of the enzyme. The calculated pKa of the Glu increases substantially when the side chain moves down. The energy barrier required to rotate the catalytic Glu residue back to the upward conformation, where it can protonate the glycosidic oxygen of the substrate, is 4.3 kcal/mol according to free energy simulations. These findings shed light on the initial stage of the glycoside hydrolysis reaction in which molecular motion enables the general acid catalyst to obtain a proton from the bulk solvent and deliver it to the glycosidic oxygen. PMID:26392527

  20. TU-FG-BRB-01: Dual Energy CT Proton Stopping Power Ratio Calibration and Validation with Animal Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y; Yin, L; Ainsley, C; McDonough, J; Solberg, T; Lin, A; Teo, B [University of Pennsylvania, Philadelphia, PA (United States)

    2016-06-15

    Purpose: The conversion of Hounsfield Unit (HU) to proton stopping power ratio (SPR) is a main source of uncertainty in proton therapy. In this study, the SPRs of animal tissues were measured and compared with prediction from dual energy CT (DECT) and single energy CT (SECT) calibrations. Methods: A stoichiometric calibration method for DECT was applied to predict the SPR using CT images acquired at 80 kVp and 140 kVp. The dual energy index was derived based on the HUs of the paired spectral images and used to calculate the SPRs of the materials. Tissue surrogates with known chemical compositions were used for calibration, and animal tissues (pig brain, liver, kidney; veal shank, muscle) were used for validation. The materials were irradiated with proton pencil beams, and SPRs were deduced from the residual proton range measured using a multi-layer ion chamber device. In addition, Gafchromic EBT3 films were used to measure the distal dose profiles after irradiation through the tissue samples and compared with those calculated by the treatment planning system using both DECT and SECT predicted SPRs. Results: The differences in SPR between DECT prediction and measurement were −0.31±0.36% for bone, 0.47±0.42% for brain, 0.67±0.15% for liver, 0.51±0.52% for kidney, and −0.96±0.15% for muscle. The corresponding results using SECT were 3.1±0.12%, 1.90±0.45%, −0.66±0.11%, 2.33±0.21%, and −1.70±0.17%. In the film measurements, average distances between film and calculated distal dose profiles were 0.35±0.12 mm for DECT calibration and −1.22±0.12 mm for SECT calibration for a beam with a range of 15.79 cm. Conclusion: Our study indicates that DECT is superior to SECT for proton SPR prediction and has the potential to reduce the range uncertainty to less than 2%. DECT may permit the use of tighter distal and proximal range uncertainty margins for treatment, thereby increasing the precision of proton therapy.

  1. Residual Stresses In 3013 Containers

    International Nuclear Information System (INIS)

    Mickalonis, J.; Dunn, K.

    2009-01-01

    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  2. Evaluation of residue-residue contact predictions in CASP9

    KAUST Repository

    Monastyrskyy, Bohdan; Fidelis, Krzysztof; Tramontano, Anna; Kryshtafovych, Andriy

    2011-01-01

    This work presents the results of the assessment of the intramolecular residue-residue contact predictions submitted to CASP9. The methodology for the assessment does not differ from that used in previous CASPs, with two basic evaluation measures

  3. Proton femtoscopy at STAR

    International Nuclear Information System (INIS)

    Zbroszczyk, H.P.

    2011-01-01

    The analysis of two-particle femtoscopy provides a powerful tool to study the properties of matter created in heavy-ion collisions. Applied to identical and nonidentical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing additional information about source characteristics. In this paper we present the correlation functions obtained for protons and antiprotons for Au + Au collisions at √ s NN = 62.4 and 200 GeV. On the other hand, as STAR experiment participates in the Beam Energy Scan (BES) program, we present theoretical predictions of p - p , p-bar - p-bar and p - p-bar femtoscopic measurements, based on UrQMD simulation for √ s NN = 5-39 GeV

  4. Proton synchrotron accelerator theory

    International Nuclear Information System (INIS)

    Wilson, E.J.N.

    1977-01-01

    This is the text of a series of lectures given as part of the CERN Academic Training Programme and primarily intended for young engineers and technicians in preparation for the running-in of the 400 GeV Super Proton Synchrotron (SPS). Following the definition of basic quantities, the problems of betatron motion and the effect of momentum spread and orbital errors on the transverse motion of the beam are reviewed. Consideration is then given to multipole fields, chromaticity and non-linear resonances. After dealing with basic relations governing longitudinal beam dynamics, the space-charge, resistive-wall and other collective effects are treated, with reference to precautions in the SPS to prevent their occurrence. (Auth.)

  5. Proton decay: 1982

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1982-01-01

    Employing the current world average Λ/sub MS/ = 0.160 GeV as input, the minimal Georgi-Glashow SU(5) model predicts sin 2 theta/sub W/(m/sub W/) = 0.214, m/sub b//m/sub tau/ approx. = 2.8 and tau/sub p/ approx. = (0.4 approx. 12) x 10 29 yr. The first two predictions are in excellent agreement with experiment; but the implied proton lifetime is already somewhat below the present experimental bound. In this status report, uncertainties in tau/sub p/ are described and effects of appendages to the SU(5) model (such as new fermion generations, scalars, supersymmetry, etc.) are examined

  6. Evaluation of pesticide residues in fruits and vegetables from Algeria.

    Science.gov (United States)

    Mebdoua, Samira; Lazali, Mohamed; Ounane, Sidi Mohamed; Tellah, Sihem; Nabi, Fahima; Ounane, Ghania

    2017-06-01

    A total of 160 samples of 13 types of fresh fruits and vegetables from domestic production and import were analysed to detect the presence of pesticide residues. Analysis was performed by multi-residual extraction followed by gas chromatography-mass spectrometry. In 42.5% of the tested samples, no residues were found and 12.5% of samples contained pesticide residues above maximum residue limits. Risk assessment for long-term exposure was done for all pesticides detected in this study. Except chlorpyrifos and lambda-cyhalothrin, exposure to pesticides from vegetables and fruits was below 1% of the acceptable daily intake. Short-term exposure assessment revealed that in seven pesticide/commodity combinations, including three pesticides (chlorpyrifos, deltamethrin and lambda-cyhalothrin), the acute reference dose had been exceeded.

  7. BROOKHAVEN: Proton goal reached

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10 13 protons per pulse (ppp), by accelerating 6.3 x 10 13 ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10 13 ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10 13 ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10 13 ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10 13 ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found

  8. BROOKHAVEN: Proton goal reached

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10{sup 13} protons per pulse (ppp), by accelerating 6.3 x 10{sup 13} ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10{sup 13} ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10{sup 13} ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10{sup 13} ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10{sup 13} ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found.

  9. Sharing Residual Liability

    DEFF Research Database (Denmark)

    Carbonara, Emanuela; Guerra, Alice; Parisi, Francesco

    2016-01-01

    Economic models of tort law evaluate the efficiency of liability rules in terms of care and activity levels. A liability regime is optimal when it creates incentives to maximize the value of risky activities net of accident and precaution costs. The allocation of primary and residual liability...... for policy makers and courts in awarding damages in a large number of real-world accident cases....

  10. Residual water treatment for gamma radiation

    International Nuclear Information System (INIS)

    Mendez, L.

    1990-01-01

    The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs

  11. Some problems of residual activity measurements

    International Nuclear Information System (INIS)

    Katrik, P.; Mustafin, E.; Strasik, I.; Pavlovic, M.

    2013-01-01

    As a preparatory work for constructing the Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt, samples of copper were irradiated by 500 MeV/u 238 U ion beam and investigated by gamma-ray spectroscopy. The nuclides that contribute dominantly to the residual activity have been identified and their contributions have been quantified by two different methods: from the whole-target gamma spectra and by integration of depth-profiles of residual activity of individual nuclides. Results obtained by these two methods are compared and discussed in this paper. (authors)

  12. Color center formation in plutonium electrorefining residues

    International Nuclear Information System (INIS)

    Morris, D.E.; Eller, P.G.; Hobart, D.E.; Eastman, M.P.; McCurry, L.E.

    1989-01-01

    Plutonium electrorefining residues containing Pu(III) in KCl exhibit dramatic reversible, light-induced color changes. Similar color changes were observed in Ln-doped (Ln = La, Nd, Gd, and Lu) and undoped KCl samples which were subjected to intense gamma irradiation. Diffuse reflectance electronic and electron paramagnetic resonance spectroscopies were used to show conclusively that Pu(III) is present in both the bleached and unbleached plutonium-bearing residues and the spectacular color changes are the result of color center formation and alternation by visible light. (orig.)

  13. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    International Nuclear Information System (INIS)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-01-01

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A

  14. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    Energy Technology Data Exchange (ETDEWEB)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-09-22

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A.

  15. A first look at logging residue characteristics in West Virginia

    Science.gov (United States)

    A. Jeff Martin

    1975-01-01

    In 1973 and 1974, the Forest Products Marketing Laboratory obtained some preliminary information about characteristics of logging residues in West Virginia. Sixteen 1-acre plots were measured in conjunction with a test of the line-intersect sampling method. Findings from the 16 plots showed that hardwood residue volumes ranged from 100 to 1,300 cubic feet per acre,...

  16. Assessment of pesticide residues in tomatoes and watermelons ...

    African Journals Online (AJOL)

    This study investigated the levels of pesticide residues in selected fruits from major markets in Dar es Salaam city. Samples of tomatoes and watermelons were analysed for eighteen organochlorine, organophosphorus and pyrethroid pesticide residues. Extraction was performed using acetone followed by dichloromethane: ...

  17. Evaluation of Some Pesticide Residues in Stored Beans in Jos ...

    African Journals Online (AJOL)

    Qualitative and quantitative analysis were performed by gas chromatography with electron capture and flame ionization. All the 3 samples (100%) contained pesticide residues beyond the allowed beans maximum residue levels (MRLs) of 0.01 mg/kg and 0.2 mg/kg, respectively, for chlorpyrifos and endosulfan. The present ...

  18. Residual Wage Differences by Gender: Bounding the Estimates.

    Science.gov (United States)

    Sakellariou, Chris N.; Patrinos, Harry A.

    1996-01-01

    Uses data from the 1986 Canadian labor market activity survey file to derive estimates of residual gender wage gap differences. Investigates these estimates' dependence on experimental design and on assumptions about discrimination-free wage structures. Residual differences persist, even after restricting the sample to a group of highly motivated,…

  19. PIXE analysis using external proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Potocek, V; Potockova, J; Dzmuran, R; Sikora, J

    1985-03-01

    The possibilities were studied of the practical use of the analytical PIXE method. Calibration samples were analyzed of Cu, Cd, Hg and Pb in concentrations of 50 to 500 ..mu..g/l as well as natural samples of drinking water, pond water, human blood plasma, dry waste from ground vegetation, mushrooms, pine needles, aerosols, human hair, leaves and flowers, etc. The samples were processed using precipitation, mineralization or incineration and were trapped on a membrane filter (Synpor) or on a Tatrafan ON 15 foil. Some samples were freeze-dried and compressed into pellets. A proton beam with an intensity of 10 to 70 nA was used for analysis and the proton energy was selected 2.2 MeV. For most targets an exposure of 120 s was preset and the measurement lasted at least 60 s and 600 s at the most. It was found that Synpor filters browned and became more brittle during longer exposures. The other targets did not change during analysis.

  20. Two proton decay in 12O

    International Nuclear Information System (INIS)

    Kumawat, M.; Singh, U.K.; Jain, S.K.; Saxena, G.; Kaushik, M.; Aggarwal, Mamta

    2017-01-01

    Two-proton radioactivity was observed experimentally in the decay of 45 Fe, 54 Zn and 48 Ni. From then many theoretical studies of one and two-proton radioactivity have been carried out within the framework of different models including RMF+BCS approach for medium mass region. Towards light mass region proton-proton correlations were observed in two-proton decay of 19 Mg and 16 Ne. Recently, different mechanism of two-proton emission from proton-rich nuclei 23 Al and 22 Mg has been investigated and transition from direct to sequential two-proton decay in sd shell nuclei is observed. Encouraged with these recent studies of two proton emission in light mass nuclei, we have applied our RMF+BCS approach for the study of two proton emission in light mass region and in this paper we present our result of two proton emission in 12 O

  1. Neutron protein crystallography hydrogen protons and hydration in bio-macromolecules

    CERN Document Server

    Niimura, Nobuo

    2011-01-01

    This text is dedicated to the emerging field of neutron protein crystallography (NPC). It covers all of the practical aspects of NPC and demonstrates how NPC can explore protein features such as hydrogen bonds, protonation and deprotonation of amino acid residues, and hydration structures.

  2. Deamidation reactions of protonated asparagine and glutamine investigated by ion spectroscopy

    NARCIS (Netherlands)

    Kempkes, L.J.M.; Martens, J.K.; Grzetic, J.; Berden, G.; Oomens, J.

    2016-01-01

    RATIONALE: Deamidation of Asn and Gln residues is a primary route for spontaneous post-translational protein modification. Several structures have been proposed for the deamidation products of the protonated amino acids. Here we verify these structures by ion spectroscopy, as well as the structures

  3. Kinetic enantioselectivity of a protonated bis(diamido)-bridged basket resorcin[4]arene towards alanine peptides.

    Science.gov (United States)

    Fraschetti, C; Montagna, M; Crestoni, M E; Calcaterra, A; Aiello, F; Santi, L; Filippi, A

    2017-02-01

    Efficient enantiodiscrimination of some alanine-containing di- and tri-peptides by using chiral protonated bis(diamido)-bridged basket resorcin[4]arenes depends on several factors, including the basicity of the amino acid residues at the C- and N-termini of the peptide.

  4. Model-based fault detection for proton exchange membrane fuel cell ...

    African Journals Online (AJOL)

    In this paper, an intelligent model-based fault detection (FD) is developed for proton exchange membrane fuel cell (PEMFC) dynamic systems using an independent radial basis function (RBF) networks. The novelty is that this RBF networks is used to model the PEMFC dynamic systems and residuals are generated based ...

  5. Probing hydrogen bonding interactions and proton transfer in proteins

    Science.gov (United States)

    Nie, Beining

    Scope and method of study. Hydrogen bonding is a fundamental element in protein structure and function. Breaking a single hydrogen bond may impair the stability of a protein. It is therefore important to probe dynamic changes in hydrogen bonding interactions during protein folding and function. Time-resolved Fourier transform infrared spectroscopy is highly sensitive to hydrogen bonding interactions. However, it lacks quantitative correlation between the vibrational frequencies and the number, type, and strength of hydrogen bonding interactions of ionizable and polar residues. We employ quantum physics theory based ab initio calculations to study the effects of hydrogen bonding interactions on vibrational frequencies of Asp, Glu, and Tyr residues and to develop vibrational spectral markers for probing hydrogen bonding interactions using infrared spectroscopy. In addition, proton transfer process plays a crucial role in a wide range of energy transduction, signal transduction, and enzymatic reactions. We study the structural basis for proton transfer using photoactive yellow protein as an excellent model system. Molecular dynamics simulation is employed to investigate the structures of early intermediate states. Quantum theory based ab initio calculations are used to study the impact of hydrogen bond interactions on proton affinity and proton transfer. Findings and conclusions. Our extensive density function theory based calculations provide rich structural, spectral, and energetic information on hydrogen bonding properties of protonated side chain groups of Asp/Glu and Tyr. We developed vibrational spectral markers and 2D FTIR spectroscopy for structural characterization on the number and the type of hydrogen bonding interactions of the COOH group of Asp/Glu and neutral phenolic group of Tyr. These developments greatly enhance the power of time-resolved FTIR spectroscopy as a major experimental tool for structural characterization of functionally important

  6. High intensity proton accelerator and its application (Proton Engineering Center)

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi

    1995-01-01

    A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, Spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

  7. Proton-proton elastic scattering measurements at COSY

    Energy Technology Data Exchange (ETDEWEB)

    Bagdasarian, Zara [Forschungszentrum Juelich, Juelich (Germany); Tbilisi State University, Tbilisi (Georgia); Collaboration: ANKE-Collaboration

    2014-07-01

    To construct the reliable phase shift analysis (PSA) that can successfully describe the nucleon-nucleon (NN) interaction it is necessary to measure variety of experimental observables for both proton-proton (pp) and neutron-proton (np) elastic scattering. The polarized beams and targets at COSY-ANKE facility allow a substantial contribution to the existing database. The experiment was carried out in April 2013 at ANKE using a transversely polarized proton beam incident on an unpolarized hydrogen cluster target. Six beam energies of T{sub p}=0.8,1.6,1.8,2.0,2.2,2.4 GeV were used. The aim of this talk is to present the preliminary results for the analyzing power (A{sub y}) for the pp elastic scattering in the so-far unexplored 5 <θ{sub cm}<30 angular range. Our measurements are also compared to the world data and current partial wave solutions.

  8. Where is the proton's spin?

    International Nuclear Information System (INIS)

    Close, F.E.

    1988-01-01

    There has been much recent excitement arising from the claim by the EMC collaboration that none of the proton's spin is carried by quarks. There are many textbooks, including those written by some members of this audience, which assert that the proton's spin is carried by quarks. I will review the history of deep inelastic scattering of polarized leptons from polarized protons, culminating in this most recent dramatic claim. I will show that, for the last decade, data have appeared consistent with predictions of the quark model and highlight what the new and potentially exciting data are. I will conclude with suggestions for the future. 33 refs

  9. Acceleration of polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1998-01-01

    The acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. Full Siberian snakes are being developed for RHIC to make the acceleration of polarized protons to 250 GeV possible. A similar scheme is being studied for the 800 GeV HERA proton accelerator

  10. Where is the proton's spin?

    International Nuclear Information System (INIS)

    Close, F.E.

    1989-01-01

    There has been much recent excitement arising from the claim by the EMC collaboration that none of the proton's spin is carried by quarks. There are many textbooks, including those written by some members of this audience, which assert that the proton's spin is carried by quarks. I will review the history of deep inelastic scattering of polarized leptons from polarized protons, culminating in this most recent dramatic claim. I will show that, for the last decade, data have appeared consistent with predictions of the quark model and highlight what the new and potentially exciting data are. I will conclude with suggestions for the future

  11. Measurement of proton autoneutralization potential

    International Nuclear Information System (INIS)

    Garcia, M.

    1984-09-01

    A proton space charge having multi-MeV kinetic energy was injected through a thin ground plane to extract electrons and produce a time-dependent autoneutralization space potential. An electon-emitting floating-potential resistive divider was used to measure the space potential during 20 ns of the proton current pulse. During this time, proton kinetic energy fell from 10.6 MeV to 8.5 MeV and thus the space potential (taken as 1.09 x the floating potential) fell from 5.8 kV to 4.6 kV

  12. Scattering of intermediate energy protons

    International Nuclear Information System (INIS)

    Chaumeaux, Alain.

    1980-06-01

    The scattering of 1 GeV protons appears to be a powerful means of investigating nuclear matter. We worked with SPESI and the formalism of Kerman-Mc Manus and Thaler. The amplitude of nucleon-nucleon scattering was studied as were the aspects of 1 GeV proton scattering (multiple scattering, absorption, spin-orbit coupling, N-N amplitude, KMT-Glauber comparison, second order effects). The results of proton scattering on 16 O, the isotopes of calcium, 58 Ni, 90 Zr and 208 Pb are given [fr

  13. Correlation of beam loss to residual activation in the AGS

    International Nuclear Information System (INIS)

    Brown, K.A.

    1991-01-01

    Studies of beam loss and activation at the AGS have provided a better understanding of measurements of beam loss and how they may be used to predict activation. Studies have been done in which first order correlations have been made between measured beam losses on the distributed ionization chamber system in the AGS and the health physics recorded residual activation. These studies have provided important insight into the ionization chamber system, its limitations, and its usefulness in the prediction of activation based on monitored beam loss. In recent years the AGS has run high intensity protons primarily for rare kaon decay experiments. In this mode of running the AGS typically accelerates beam from an injection momentum of 0.644 GeV/c up to a slow extracted beam (SEB) momentum of 24.2 GeV/c. The beam intensities are on the order of 4.5 x 10 13 protons per AGS cycle at injection to as high as 1.9 x 10 13 protons per AGS cycle at extraction. Residual activation varies around the AGS ring from the order of 5 mR/hour to levels of the order at 5 R/hour. The highest levels occur around the AGS beam catcher and the extraction equipment

  14. Machine for compacting solid residues

    International Nuclear Information System (INIS)

    Herzog, J.

    1981-11-01

    Machine for compacting solid residues, particularly bulky radioactive residues, constituted of a horizontally actuated punch and a fixed compression anvil, in which the residues are first compacted horizontally and then vertically. Its salient characteristic is that the punch and the compression anvil have embossments on the compression side and interpenetrating plates in the compression position [fr

  15. Aspects of the fundamental theory of proton-proton scattering

    CERN Document Server

    Martin, A

    1973-01-01

    After recalling the existence of a high energy bound on proton-proton total cross-sections, the author discusses the various phenomena which occur when these cross-sections rise and especially when they have the qualitative behaviour of the bound: rising elastic cross- sections, shrinking diffraction peak, validity of the Pomeranchuk theorem for total and elastic cross-sections, existence of a positive real part of the forward amplitude at high energies. (16 refs).

  16. Proton-proton elastic scattering at ultrahigh energies

    International Nuclear Information System (INIS)

    Saleem, M.; Shaukat, M.A.; Fazal-e-Aleem

    1981-01-01

    Recent experimental results on proton-proton elastic scattering at high energies are discussed in the context of the comments by Chou and Yang. There does not appear to be any tendency that the experimental results would agree with the predictions of the geometrical model even at ultrahigh energies. The angular distribution structure as described by using the dipole pomeron is consistent with the experimental data at presently available high energies and predicts results quite different from the geometrical model. (author)

  17. Proton-proton elastic scattering at ultrahigh energies

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Shaukat, M.A.; Fazal-e-Aleem (University of the Punjab, Lahore (Pakistan). Dept. of Physics)

    1981-05-30

    Recent experimental results on proton-proton elastic scattering at high energies are discussed in the context of the comments by Chou and Yang. There does not appear to be any tendency that the experimental results would agree with the predictions of the geometrical model even at ultrahigh energies. The angular distribution structure as described by using the dipole pomeron is consistent with the experimental data at presently available high energies and predicts results quite different from the geometrical model.

  18. Proton current measurements using the prompt gamma ray diagnostic technique

    International Nuclear Information System (INIS)

    Leeper, R.J.; Burns, E.J.T.; Johnson, D.J.; McMurtry, W.M.

    1981-01-01

    Prompt gamma ray signals from the nuclear reaction 7 Li(p,γ) 8 Be have been used to make time resolved proton current measurements. In these measurements, the proton beam was allowed to strike cylindrical thick lithium metal targets. The time integrated proton current was measured using gamma activation of copper via the reaction 63 Cu(γ,n) 62 Cu(β+). The positron activity of the copper sample was easily measured using coincidence counting techniques. The number of 62 Cu atoms produced per proton incident on a thick Li metal target was determined with separate calibration runs performed on the Sandia 2.5 MeV Van de Graaff accelerator. The time history of the prompt gamma production was measured using six EGG NPM-54 scintillator photomultiplier combinations shielded by 96.5 cm of concrete and 5.1 cm of Pb. The use of six scintillator photomultiplier combinations was necessary to increase the statistical precision of the data. The normalization of the prompt gamma time history data with the total time integrated proton-current measurement yielded the absolute time resolved proton current on target. Data from runs performed on the Sandia Proto I accelerator will be presented

  19. Quadratic residues and non-residues selected topics

    CERN Document Server

    Wright, Steve

    2016-01-01

    This book offers an account of the classical theory of quadratic residues and non-residues with the goal of using that theory as a lens through which to view the development of some of the fundamental methods employed in modern elementary, algebraic, and analytic number theory. The first three chapters present some basic facts and the history of quadratic residues and non-residues and discuss various proofs of the Law of Quadratic Reciprosity in depth, with an emphasis on the six proofs that Gauss published. The remaining seven chapters explore some interesting applications of the Law of Quadratic Reciprocity, prove some results concerning the distribution and arithmetic structure of quadratic residues and non-residues, provide a detailed proof of Dirichlet’s Class-Number Formula, and discuss the question of whether quadratic residues are randomly distributed. The text is a valuable resource for graduate and advanced undergraduate students as well as for mathematicians interested in number theory.

  20. Proton-bound cluster ions in ion mobility spectrometry

    Science.gov (United States)

    Ewing, R. G.; Eiceman, G. A.; Stone, J. A.

    1999-01-01

    Gaseous oxygen and nitrogen bases, both singly and as binary mixtures, have been introduced into ion mobility spectrometers to study the appearance of protonated molecules, and proton-bound dimers and trimers. At ambient temperature it was possible to simultaneously observe, following the introduction of molecule A, comparable intensities of peaks ascribable to the reactant ion (H2O)nH+, the protonated molecule AH+ and AH+ H2O, and the symmetrical proton bound dimer A2H+. Mass spectral identification confirmed the identifications and also showed that the majority of the protonated molecules were hydrated and that the proton-bound dimers were hydrated to a much lesser extent. No significant peaks ascribable to proton-bound trimers were obtained no matter how high the sample concentration. Binary mixtures containing molecules A and B, in some cases gave not only the peaks unique to the individual compounds but also peaks due to asymmetrical proton bound dimers AHB+. Such ions were always present in the spectra of mixtures of oxygen bases but were not observed for several mixtures of oxygen and nitrogen bases. The dimers, which were not observable, notable for their low hydrogen bond strengths, must have decomposed in their passage from the ion source to the detector, i.e. in a time less than approximately 5 ms. When the temperature was lowered to -20 degrees C, trimers, both homogeneous and mixed, were observed with mixtures of alcohols. The importance of hydrogen bond energy, and hence operating temperature, in determining the degree of solvation of the ions that will be observed in an ion mobility spectrometer is stressed. The possibility is discussed that a displacement reaction involving ambient water plays a role in the dissociation.

  1. Proton mobility on the surface of some acid salt crystal hydrates

    International Nuclear Information System (INIS)

    Yaroslavtsev, A.B.; Mirak'yan, A.L.; Chuvaev, V.F.; Sokolova, L.N.

    1997-01-01

    Mobility of proton-containing groupings on the surface of Zr(HPO 4 ) 2 xH 2 O and InH(SO 4 ) 2 x4H 2 O crystals of different dispersion has been studied by 1 H NMR and conductometry methods. It is shown that translational mobility of proton-containing groupings on the surface is much greater than in the sample bulk. A ratio describing the dependence of protonic conductivity on particle sizes of the compounds considered is suggested and its applicability is demonstrated. An increase in conductivity with a decrease in anion proton-accepting ability is pointed out

  2. Conformation of antifreeze glycoproteins as determined from conformational energy calculations and fully assigned proton NMR spectra

    International Nuclear Information System (INIS)

    Bush, C.A.; Rao, B.N.N.

    1986-01-01

    The 1 H NMR spectra of AFGP's ranging in molecular weight from 2600 to 30,000 Daltons isolated from several different species of polar fish have been measured. The spectrum of AFGP 1-4 from Pagothenia borchgrevinki with an average of 30 repeating subunits has a single resonance for each proton of the glycotripeptide repeating unit, (ala-[gal-(β-1→3) galNAc-(α--O-]thr-ala)/sub n/. Its 1 H NMR spectrum including resonances of the amide protons has been completely assigned. Coupling constants and nuclear Overhauser enhancements (n.O.e.) between protons on distant residues imply conformational order. The 2600 dalton molecular weight glycopeptides (AFGP-8) have pro in place of ala at certain specific points in the sequence and AFGP-8R of Eleginus gracilis has arg in place of one thr. The resonances of pro and arg were assigned by decoupling. The resonances of the carboxy and amino terminals have distinct chemical shifts and were assigned in AFGP-8 of Boreogadus saida by titration. n.O.e. between α--protons and amide protons of the adjacent residue (sequential n.O.e.) were used in assignments of additional resonances and to assign the distinctive resonances of thr followed by pro. Conformational energy calculations on the repeating glycotripeptide subunit of AFGP show that the α--glucosidic linkage has a fixed conformation while the β--linkage is less rigid. A conformational model for AFGP 1-4, which is based on the calculations has the peptide in an extended left-handed helix with three residues per turn similar to polyproline II. The model is consistent with CD data, amide proton coupling constants, temperature dependence of amide proton chemical shifts

  3. Nonadiabatic rate constants for proton transfer and proton-coupled electron transfer reactions in solution: Effects of quadratic term in the vibronic coupling expansion.

    Science.gov (United States)

    Soudackov, Alexander V; Hammes-Schiffer, Sharon

    2015-11-21

    Rate constant expressions for vibronically nonadiabatic proton transfer and proton-coupled electron transfer reactions are presented and analyzed. The regimes covered include electronically adiabatic and nonadiabatic reactions, as well as high-frequency and low-frequency proton donor-acceptor vibrational modes. These rate constants differ from previous rate constants derived with the cumulant expansion approach in that the logarithmic expansion of the vibronic coupling in terms of the proton donor-acceptor distance includes a quadratic as well as a linear term. The analysis illustrates that inclusion of this quadratic term in the framework of the cumulant expansion framework may significantly impact the rate constants at high temperatures for proton transfer interfaces with soft proton donor-acceptor modes that are associated with small force constants and weak hydrogen bonds. The effects of the quadratic term may also become significant in these regimes when using the vibronic coupling expansion in conjunction with a thermal averaging procedure for calculating the rate constant. In this case, however, the expansion of the coupling can be avoided entirely by calculating the couplings explicitly for the range of proton donor-acceptor distances sampled. The effects of the quadratic term for weak hydrogen-bonding systems are less significant for more physically realistic models that prevent the sampling of unphysical short proton donor-acceptor distances. Additionally, the rigorous relation between the cumulant expansion and thermal averaging approaches is clarified. In particular, the cumulant expansion rate constant includes effects from dynamical interference between the proton donor-acceptor and solvent motions and becomes equivalent to the thermally averaged rate constant when these dynamical effects are neglected. This analysis identifies the regimes in which each rate constant expression is valid and thus will be important for future applications to proton

  4. Nonadiabatic rate constants for proton transfer and proton-coupled electron transfer reactions in solution: Effects of quadratic term in the vibronic coupling expansion

    International Nuclear Information System (INIS)

    Soudackov, Alexander V.; Hammes-Schiffer, Sharon

    2015-01-01

    Rate constant expressions for vibronically nonadiabatic proton transfer and proton-coupled electron transfer reactions are presented and analyzed. The regimes covered include electronically adiabatic and nonadiabatic reactions, as well as high-frequency and low-frequency proton donor-acceptor vibrational modes. These rate constants differ from previous rate constants derived with the cumulant expansion approach in that the logarithmic expansion of the vibronic coupling in terms of the proton donor-acceptor distance includes a quadratic as well as a linear term. The analysis illustrates that inclusion of this quadratic term in the framework of the cumulant expansion framework may significantly impact the rate constants at high temperatures for proton transfer interfaces with soft proton donor-acceptor modes that are associated with small force constants and weak hydrogen bonds. The effects of the quadratic term may also become significant in these regimes when using the vibronic coupling expansion in conjunction with a thermal averaging procedure for calculating the rate constant. In this case, however, the expansion of the coupling can be avoided entirely by calculating the couplings explicitly for the range of proton donor-acceptor distances sampled. The effects of the quadratic term for weak hydrogen-bonding systems are less significant for more physically realistic models that prevent the sampling of unphysical short proton donor-acceptor distances. Additionally, the rigorous relation between the cumulant expansion and thermal averaging approaches is clarified. In particular, the cumulant expansion rate constant includes effects from dynamical interference between the proton donor-acceptor and solvent motions and becomes equivalent to the thermally averaged rate constant when these dynamical effects are neglected. This analysis identifies the regimes in which each rate constant expression is valid and thus will be important for future applications to proton

  5. Elastic scattering of protons at the TOTEM experiment at the LHC

    CERN Document Server

    AUTHOR|(CDS)2080719; Csanád, Máté; Niewiadomski, Hubert

    The TOTEM experiment at the LHC at CERN is optimized to measure elastic and diffractive scattering at the LHC and measures the total proton-proton cross-section with\tthe luminosity-independent method. The TOTEM experiment uses the special technique of movable beam pipe insertions -- called Roman Pots -- to detect very forward protons. The reconstruction of the forward proton kinematics requires the precise understanding of the LHC beam optics. A new method of LHC optics determination is reported, which exploits kinematical distributions of elastically scattered proton-proton data measured by the Roman Pots of the TOTEM experiment. The method has been successfully applied to data samples recorded since 2010. The interpretation of the proton-proton elastic differential cross-section is a challenging task. The geometrical model of proton-proton elastic scattering of Bialas and Bzdak is fitted to ISR data and to data measured by the TOTEM experiment at LHC energy of $\\sqrt{s}=7$~TeV. The Bialas-Bzdak model is g...

  6. Proton dose distribution measurements using a MOSFET detector with a simple dose-weighted correction method for LET effects.

    Science.gov (United States)

    Kohno, Ryosuke; Hotta, Kenji; Matsuura, Taeko; Matsubara, Kana; Nishioka, Shie; Nishio, Teiji; Kawashima, Mitsuhiko; Ogino, Takashi

    2011-04-04

    We experimentally evaluated the proton beam dose reproducibility, sensitivity, angular dependence and depth-dose relationships for a new Metal Oxide Semiconductor Field Effect Transistor (MOSFET) detector. The detector was fabricated with a thinner oxide layer and was operated at high-bias voltages. In order to accurately measure dose distributions, we developed a practical method for correcting the MOSFET response to proton beams. The detector was tested by examining lateral dose profiles formed by protons passing through an L-shaped bolus. The dose reproducibility, angular dependence and depth-dose response were evaluated using a 190 MeV proton beam. Depth-output curves produced using the MOSFET detectors were compared with results obtained using an ionization chamber (IC). Since accurate measurements of proton dose distribution require correction for LET effects, we developed a simple dose-weighted correction method. The correction factors were determined as a function of proton penetration depth, or residual range. The residual proton range at each measurement point was calculated using the pencil beam algorithm. Lateral measurements in a phantom were obtained for pristine and SOBP beams. The reproducibility of the MOSFET detector was within 2%, and the angular dependence was less than 9%. The detector exhibited a good response at the Bragg peak (0.74 relative to the IC detector). For dose distributions resulting from protons passing through an L-shaped bolus, the corrected MOSFET dose agreed well with the IC results. Absolute proton dosimetry can be performed using MOSFET detectors to a precision of about 3% (1 sigma). A thinner oxide layer thickness improved the LET in proton dosimetry. By employing correction methods for LET dependence, it is possible to measure absolute proton dose using MOSFET detectors.

  7. Proton dose distribution measurements using a MOSFET detector with a simple dose‐weighted correction method for LET effects

    Science.gov (United States)

    Hotta, Kenji; Matsuura, Taeko; Matsubara, Kana; Nishioka, Shie; Nishio, Teiji; Kawashima, Mitsuhiko; Ogino, Takashi

    2011-01-01

    We experimentally evaluated the proton beam dose reproducibility, sensitivity, angular dependence and depth‐dose relationships for a new Metal Oxide Semiconductor Field Effect Transistor (MOSFET) detector. The detector was fabricated with a thinner oxide layer and was operated at high‐bias voltages. In order to accurately measure dose distributions, we developed a practical method for correcting the MOSFET response to proton beams. The detector was tested by examining lateral dose profiles formed by protons passing through an L‐shaped bolus. The dose reproducibility, angular dependence and depth‐dose response were evaluated using a 190 MeV proton beam. Depth‐output curves produced using the MOSFET detectors were compared with results obtained using an ionization chamber (IC). Since accurate measurements of proton dose distribution require correction for LET effects, we developed a simple dose‐weighted correction method. The correction factors were determined as a function of proton penetration depth, or residual range. The residual proton range at each measurement point was calculated using the pencil beam algorithm. Lateral measurements in a phantom were obtained for pristine and SOBP beams. The reproducibility of the MOSFET detector was within 2%, and the angular dependence was less than 9%. The detector exhibited a good response at the Bragg peak (0.74 relative to the IC detector). For dose distributions resulting from protons passing through an L‐shaped bolus, the corrected MOSFET dose agreed well with the IC results. Absolute proton dosimetry can be performed using MOSFET detectors to a precision of about 3% (1 sigma). A thinner oxide layer thickness improved the LET in proton dosimetry. By employing correction methods for LET dependence, it is possible to measure absolute proton dose using MOSFET detectors. PACS number: 87.56.‐v

  8. Inelastic proton scattering at medium energy

    International Nuclear Information System (INIS)

    Love, W.G.

    1980-01-01

    Some of the most essential characteristics of the nucleon-nucleon interaction for probing nuclear structure at bombarding energies between 100 and 800 MeV are considered. With a local representation of the on-shell N-N t-matrix, data for a variety of specific transitions at IUCF and LAMPF energies are discussed with an emphasis on the nuclear structure information sampled by proton scattering. The importance of incorporating constraints on nuclear structure imposed by electron scattering is stressed. Some rather unique aspects of the (p,n) reaction at intermediate energies are discussed in terms of its energy dependence and nuclear structure sum rules. 11 figures

  9. Observation of Z production in proton-lead collisions at LHCb

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Onderwater, G.; Pellegrino, A.

    2014-01-01

    The first observation of Z boson production in proton-lead collisions at a centre-of-mass energy per proton-nucleon pair of root(s) N N = 5TeV is presented. The data sample corresponds to an integrated luminosity of 1.6 nb(-1) collected with the LHCb detector. The Z candidates are reconstructed from

  10. Emittance growth induced by electron cloud in proton storage rings

    CERN Document Server

    Benedetto, Elena; Coppa, G

    2006-01-01

    In proton and positron storage rings with many closely spaced bunches, a large number of electrons can accumulate in the beam pipe due to various mechanisms (photoemission, residual gas ionization, beam-induced multipacting). The so-formed electron cloud interacts with the positively charged bunches, giving rise to instabilities, emittance growth and losses. This phenomenon has been observed in several existing machines such as the CERN Super Proton Synchrotron (SPS), whose operation has been constrained by the electron-cloud problem, and it is a concern for the Large Hadron Collider (LHC), under construction at CERN. The interaction between the beam and the electron cloud has features which cannot be fully taken into account by the conventional and known theories from accelerators and plasma physics. Computer simulations are indispensable for a proper prediction and understanding of the instability dynamics. The main feature which renders the beam-cloud interactions so peculiar is that the the electron cloud...

  11. Source identification of a tar residue from Mumbai Beach

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A; Rokade, M.A

    A tar residue from Mumbai Beach, Maharashtra, India was matched with the suspected source sample from a tanker using UV, IR and GLC techniques. Negligible differences in several ratios of UV absorbances and ratios of infrared transmittances...

  12. Proton radiotherapy: some perspectives

    International Nuclear Information System (INIS)

    Kirn, T.F.

    1988-01-01

    A news article highlighting the use of protons in radiotherapy is presented. Development of stereotaxic radiosurgery is the result of contributions from physicists, radiologists, and neurosurgeons, says Jacob Fabrikant, MD, head of the Arteriovenous Malformation Program at the University of California's Lawrence Berkeley laboratory. It also appears to have been the product of Harvard University (Boston) and University of California (Berkeley) cooperation. Robert R. Wilson, PhD, now a professor emeritus at Cornell University, Ithaca, NY, is credited with proposing the medical use of charged particles. Wilson, a physicist, says that the idea occurred to him while he was at Berkeley in the mid-1940's, designing the cyclotron to be built at Harvard. Although he was aware of their work, he does not remember discussing it with Robert Stone, MD, or John Lawrence, MD, who only a few years earlier at Berkeley had begun the initial medical experiments with neutrons. Wilson says that it simply occurred to him that in certain instances charged particles had two advantages over x-rays

  13. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  14. Proton-proton and deuteron-deuteron correlations in interactions of relativistic helium nuclei with protons

    International Nuclear Information System (INIS)

    Galazka-Friedman, J.; Sobczak, T.; Stepaniak, J.; Zielinski, I.P.; Bano, M.; Hlavacova, J.; Martinska, G.; Patocka, J.; Seman, M.; Sandor, L.; Urban, J.

    1993-01-01

    The reactions 4 Hep→pp+X, 3 Hep→pp+X and 4 Hep→ddp have been investigated and the correlation function has been measured for protons and deuterons with small relative momenta. Strong positive correlation has been observed for protons related mainly to the final state interactions in 1 S 0 state. The root mean square radius of the proton source calculated from the correlation function has been found to be equal to (1.7±0.3) fm and (2.1±0.3) fm for 4 He and 3 He respectively. It agrees with the known radii of these nuclei. (orig.)

  15. Dynamics of Anti-Proton -- Protons and Anti-Proton -- Nucleus Reactions

    CERN Document Server

    Galoyan, A; Uzhinsky, V

    2016-01-01

    A short review of simulation results of anti-proton-proton and anti-proton-nucleus interactions within the framework of Geant4 FTF (Fritiof) model is presented. The model uses the main assumptions of the Quark-Gluon-String Model or Dual Parton Model. The model assumes production and fragmentation of quark-anti-quark and diquark-anti-diquark strings in the mentioned interactions. Key ingredients of the model are cross sections of string creation processes and an usage of the LUND string fragmentation algorithm. They allow one to satisfactory describe a large set of experimental data, especially, a strange particle production, Lambda hyperons and K mesons.

  16. Proton beam induced dynamics of tungsten granules

    Science.gov (United States)

    Caretta, O.; Loveridge, P.; O'Dell, J.; Davenne, T.; Fitton, M.; Atherton, A.; Densham, C.; Charitonidis, N.; Efthymiopoulos, I.; Fabich, A.; Guinchard, M.; Lacny, L. J.; Lindstrom, B.

    2018-03-01

    This paper reports the results from single-pulse experiments of a 440 GeV /c proton beam interacting with granular tungsten samples in both vacuum and helium environments. Remote high-speed photography and laser Doppler vibrometry were used to observe the effect of the beam on the sample grains. The majority of the results were derived from a trough containing ˜45 μ m diameter spheres (not compacted) reset between experiments to maintain the same initial conditions. Experiments were also carried out on other open and contained samples for the purposes of comparison both with the 45 μ m grain results and with a previous experiment carried out with sub-250 μ m mixed crystalline tungsten powder in helium [Phys. Rev. ST Accel. Beams 17, 101005 (2014), 10.1103/PhysRevSTAB.17.101005]. The experiments demonstrate that a greater dynamic response is produced in a vacuum than in a helium environment and in smaller grains compared with larger grains. The examination of the dynamics of the grains after a beam impact leads to the hypothesis that the grain response is primarily the result of a charge interaction of the proton beam with the granular medium.

  17. Proton beam induced dynamics of tungsten granules

    Directory of Open Access Journals (Sweden)

    O. Caretta

    2018-03-01

    Full Text Available This paper reports the results from single-pulse experiments of a 440  GeV/c proton beam interacting with granular tungsten samples in both vacuum and helium environments. Remote high-speed photography and laser Doppler vibrometry were used to observe the effect of the beam on the sample grains. The majority of the results were derived from a trough containing ∼45  μm diameter spheres (not compacted reset between experiments to maintain the same initial conditions. Experiments were also carried out on other open and contained samples for the purposes of comparison both with the 45  μm grain results and with a previous experiment carried out with sub-250  μm mixed crystalline tungsten powder in helium [Phys. Rev. ST Accel. Beams 17, 101005 (2014PRABFM1098-440210.1103/PhysRevSTAB.17.101005]. The experiments demonstrate that a greater dynamic response is produced in a vacuum than in a helium environment and in smaller grains compared with larger grains. The examination of the dynamics of the grains after a beam impact leads to the hypothesis that the grain response is primarily the result of a charge interaction of the proton beam with the granular medium.

  18. Determination of Pesticides Residues in Cucumbers Grown in Greenhouse and the Effect of Some Procedures on Their Residues.

    Science.gov (United States)

    Leili, Mostafa; Pirmoghani, Amin; Samadi, Mohammad Taghi; Shokoohi, Reza; Roshanaei, Ghodratollah; Poormohammadi, Ali

    2016-11-01

    The objective of this study was to determine the residual concentrations of ethion and imidacloprid in cucumbers grown in greenhouse. The effect of some simple processing procedures on both ethion and imidacloprid residues were also studied. Ten active greenhouses that produce cucumber were randomly selected. Ethion and imidacloprid as the most widely used pesticides were measured in cucumber samples of studied greenhouses. Moreover, the effect of storing, washing, and peeling as simple processing procedures on both ethion and imidacloprid residues were investigated. One hour after pesticide application; the maximum residue levels (MRLs) of ethion and imidacloprid were higher than that of Codex standard level. One day after pesticide application, the levels of pesticides were decreased about 35 and 31% for ethion and imidacloprid, respectively, which still were higher than the MRL. Washing procedure led to about 51 and 42.5% loss in ethion and imidacloprid residues, respectively. Peeling procedure also led to highest loss of 93.4 and 63.7% in ethion and imidacloprid residues, respectively. The recovery for both target analytes was in the range between 88 and 102%. The residue values in collected samples one hour after pesticides application were higher than standard value. The storing, washing, and peeling procedures lead to the decrease of pesticide residues in greenhouse cucumbers. Among them, the peeling procedure has the greatest impact on residual reduction. Therefore, these procedures can be used as simple and effective processing techniques for reducing and removing pesticides from greenhouse products before their consumption.

  19. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Niklas [KTH Royal Institute of Technology, Stockholm (Sweden)

    2007-01-01

    Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e±, ve, $\\bar{v}$e, vμ and $\\bar{μ}$e--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the Δ(1232) and the other multiple resonances with masses around 1600 MeV/c2. The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on the Feynman-scaling hypothesis. The applications of the presented model in astrophysics are plentiful. It has been implemented into the Galprop code to calculate the contribution due to pion decays in the Galactic plane. The model has also been used to estimate the cosmic-ray flux in the Large Magellanic Cloud based on HI, CO and gamma-ray observations. The transverse momentum distributions enable calculations when the proton distribution is anisotropic. It is shown that the gamma-ray spectrum and flux due to a

  20. Proton beam monitor chamber calibration

    International Nuclear Information System (INIS)

    Gomà, C; Meer, D; Safai, S; Lorentini, S

    2014-01-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

  1. On the proton radius problem

    OpenAIRE

    Giannini, M. M.; Santopinto, E.

    2013-01-01

    The recent values of the proton charge radius obtained by means of muonic-hydrogen laser spectroscopy are about $4\\%$ different from the electron scattering data. It has been suggested that the proton radius is actually measured in different frames and that, starting from a non relativistic quark model calculation, the Lorentz transformation of the form factors accounts properly for the discepancy. We shall show that the relation between the charge radii measured in different frames can be de...

  2. LHC Optics Measurement with Proton Tracks Detected by the Roman Pots of the TOTEM Experiment

    CERN Document Server

    INSPIRE-00062364; Aspell, P; Atanassov, I; Avati, V; Baechler, J; Berardi, V; Berretti, M; Bossini, E; Bottigli, U; Bozzo, M; Brücken, E; Buzzo, A; Cafagna, F S; Catanesi, M G; Covault, C; Csanád, M; Csörgö, T; Deile, M; Doubek, M; Eggert, K; Eremin, V; Ferro, F; Fiergolski, A; Garcia, F; Georgiev, V; Giani, S; Grzanka, L; Hammerbauer, J; Heino, J; Hilden, T; Karev, A; Kašpar, J; Kopal, J; Kundrát, V; Lami, S; Latino, G; Lauhakangas, R; Leszko, T; Lippmaa, E; Lippmaa, J; Lokajíček, M V; Losurdo, L; Lo Vetere, M; Lucas Rodríguez, F; Macrí, M; Mäki, T; Mercadante, A; Minafra, N; Minutoli, S; Nemes, F; Niewiadomski, H; Oliveri, E; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Palazzi, P; Peroutka, Z; Procházka, J; Quinto, M; Radermacher, E; Radicioni, E; Ravotti, F; Robutti, E; Ropelewski, L; Ruggiero, G; Saarikko, H; Scribano, A; Smajek, J; Snoeys, W; Sziklai, J; Taylor, C; Turini, N; Vacek, V; Welti, J; Whitmore, J; Wyszkowski, P; Zielinski, K

    2014-10-28

    Precise knowledge of the beam optics at the LHC is crucial to fulfil the physics goals of the TOTEM experiment, where the kinematics of the scattered protons is reconstructed with the near-beam telescopes -- so-called Roman Pots (RP). Before being detected, the protons' trajectories are influenced by the magnetic fields of the accelerator lattice. Thus precise understanding of the proton transport is of key importance for the experiment. A novel method of optics evaluation is proposed which exploits kinematical distributions of elastically scattered protons observed in the RPs. Theoretical predictions, as well as Monte Carlo studies, show that the residual uncertainty of this optics estimation method is smaller than 0.25 percent.

  3. Bioenergy from sisal residues

    Energy Technology Data Exchange (ETDEWEB)

    Jungersen, G. [Dansk Teknologisk Inst. (Denmark); Kivaisi, A.; Rubindamayugi, M. [Univ. of Dar es Salaam (Tanzania, United Republic of)

    1998-05-01

    The main objectives of this report are: To analyse the bioenergy potential of the Tanzanian agro-industries, with special emphasis on the Sisal industry, the largest producer of agro-industrial residues in Tanzania; and to upgrade the human capacity and research potential of the Applied Microbiology Unit at the University of Dar es Salaam, in order to ensure a scientific and technological support for future operation and implementation of biogas facilities and anaerobic water treatment systems. The experimental work on sisal residues contains the following issues: Optimal reactor set-up and performance; Pre-treatment methods for treatment of fibre fraction in order to increase the methane yield; Evaluation of the requirement for nutrient addition; Evaluation of the potential for bioethanol production from sisal bulbs. The processing of sisal leaves into dry fibres (decortication) has traditionally been done by the wet processing method, which consumes considerable quantities of water and produces large quantities of waste water. The Tanzania Sisal Authority (TSA) is now developing a dry decortication method, which consumes less water and produces a waste product with 12-15% TS, which is feasible for treatment in CSTR systems (Continously Stirred Tank Reactors). (EG)

  4. Proton therapy project at PSI

    International Nuclear Information System (INIS)

    Nakagawa, K.; Akanuma, A.; Karasawa, K.

    1990-01-01

    Particle radiation which might present steeper dose distribution has received much attention as the third particle facility at the Paul Scherrer Institute (PSI), Switzerland. Proton conformation with sharp fall-off is considered to be the radiation beam suitable for confining high doses to a target volume without complications and for verifying which factor out of high RBE or physical dose distribution is more essential for local control in malignant tumors. This paper discusses the current status of the spot scanning method, which allows three dimensional conformation radiotherapy, and preliminary results. Preliminary dose distribution with proton conformation technique was acquired by modifying a computer program for treatment planning in pion treatment. In a patient with prostate carcinoma receiving both proton and pion radiation therapy, proton conformation was found to confine high doses to the target area and spare both the bladder and rectum well; and pion therapy was found to deliver non-homogeneous radiation to these organs. Although there are some obstacles in the proton project at PSI, experimental investigations are encouraging. The dynamic spot scanning method with combination of the kicker magnet, wobbler magnet, range shifter, patient transporter, and position sensitive monitor provides highly confined dose distribution, making it possible to increase total doses and thus to improve local control rate. Proton confirmation is considered to be useful for verifying possible biological effectiveness of negative pion treatment of PSI as well. (N.K.)

  5. When the proton becomes larger

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The TOTEM experiment at the LHC has just confirmed that, at high energy, protons behave as if they were becoming larger. In more technical terms, their total cross-section – a parameter linked to the proton-proton interaction probability – increases with energy. This phenomenon, expected from previous measurements performed at much lower energy, has now been confirmed for the first time at the LHC’s unprecedented energy.   One arm of a T