WorldWideScience

Sample records for fragment mass distributions

  1. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  2. Fission fragment mass distributions via prompt γ-ray spectroscopy

    Indian Academy of Sciences (India)

    The distribution of fragment masses formed in nuclear fission is one of the most strik- ing features .... 80. 100. 120. 140. 160. 10. 3. 10. 4. Fragment Mass. Relative yield. Sn. Cd. Te. Pd ... the secondary fragment at Z = 50 and N = 82 shells, where the yields are depleted. Both ... More systematic experimental data are required.

  3. Analysis of fission-fragment mass distribution within the quantum-mechanical fragmentation theory

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pardeep; Kaur, Harjeet [Guru Nanak Dev University, Department of Physics, Amritsar (India)

    2016-11-15

    The fission-fragment mass distribution is analysed for the {sup 208}Pb({sup 18}O, f) reaction within the quantum-mechanical fragmentation theory (QMFT). The reaction potential has been calculated by taking the binding energies, Coulomb potential and proximity potential of all possible decay channels and a stationary Schroedinger equation has been solved numerically to calculate the fission-fragment yield. The overall results for mass distribution are compared with those obtained in experiment. Fine structure dips in yield, corresponding to fragment shell closures at Z = 50 and N=82, which are observed by Bogachev et al., are reproduced successfully in the present calculations. These calculations will help to estimate the formation probabilities of fission fragments and to understand many related phenomena occurring in the fission process. (orig.)

  4. Mass distribution law of systems of protocluster fragments

    Energy Technology Data Exchange (ETDEWEB)

    Ferraioli, F; Virgopia, N [Rome Univ. (Italy). Ist. di Matematica

    1979-02-01

    Starting from the hypothesis of coalescence through inelastic collisions of small fast moving interstellar gas clouds, an attempt has been made to study the evolutionary mass distribution of a system of fragments simulating a protocluster. The assumption of a mass spectrum with a continuous injection of newly formed entities into the primeval system, and the condition of gravitational reduction of the impact cross-section, have been considered. Comparisons of numerical experiments with the mass spectrum in some well-known young galactic clusters, confirm the mass distribution power-law already obtained by other authors. The empirical Schmidt's law concerning the rate of star formation is also confirmed. The hypothesis of the universal validity of the luminosity function, should not be 'a priori' rejected.

  5. 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

  6. Effects of fissioning nuclei distributions on fragment mass distributions for high energy fission

    Directory of Open Access Journals (Sweden)

    Rossi P C R

    2012-02-01

    Full Text Available We study the effects of fissioning nuclei mass- and energy-distributions on the formation of fragments for fission induced by high energy probes. A Monte Carlo code called CRISP was used for obtaining mass distributions and spectra of the fissioning nuclei for reactions induced by 660 MeV protons on 241Am and on 239Np, by 500 MeV protons on 208Pb, and by Bremsstrahlung photons with end-point energies at 50 MeV and 3500 MeV on 238U. The results show that even at high excitation energies, asymmetric fission may still contribute significantly to the fission cross section of actinide nuclei, while it is the dominante mode in the case of lead. However, more precise data for high energy fission on actinide are necessary in order to allow definite conclusions.

  7. Mass distribution of fission fragments within the Born-Oppenheimer approximation

    Energy Technology Data Exchange (ETDEWEB)

    Pomorski, K.; Nerlo-Pomorska, B. [M.C.S. University, Department of Theoretical Physics, Lublin (Poland); Ivanyuk, F.A. [Institute for Nuclear Research, Kiev (Ukraine)

    2017-03-15

    The fission fragments mass-yield of {sup 236} U is obtained by an approximate solution of the eigenvalue problem of the collective Hamiltonian that describes the dynamics of the fission process whose degrees of freedom are: the fission (elongation), the neck and mass-asymmetry modes. The macroscopic-microscopic method is used to evaluate the potential energy surface. The macroscopic energy part is calculated using the liquid drop model and the microscopic corrections are obtained using a Woods-Saxon single-particle levels. The four-dimensional modified Cassini ovals shape parametrization is used to describe the shape of the fissioning nucleus. The mass tensor is taken within a cranking-type approximation. The final fragment mass distribution is obtained by weighting the adiabatic density distribution in the collective space with the neck-dependent fission probability. The neck degree of freedom is found to play a significant role in determining the final fragment mass distribution. (orig.)

  8. Mass distribution of fission fragments using SSNTDs based image analysis system

    International Nuclear Information System (INIS)

    Kolekar, R.V.; Sharma, D.N.

    2006-01-01

    Lexan polycarbonate track detector was used to obtain mass distribution of fission fragments from 252 Cf planchette source, Normally, if the fission fragments are incident perpendicular to the lexan surface, the diameter of heavy fragment is greater than that of lighter fragment. In practical problems fission fragments are incident on the detector at all angles. So, in the present experiment, lexan detector was exposed to 252 Cf planchette source in 2π geometry. Fission fragments were incident on the detector with various angles. So the projected fission track length for fission fragment of same energy is different because of different angle of incidence. Image analysis software was used to measure the projected track length. But the problem is that for fission fragment having greater angle of incidence the entire track length is not focused on the surface. So reduced track length is measured. This problem is solved by taking two images, one at the surface and one at the tip of track and then overlapping both the images using image analysis software. The projected track length and the depth of the track were used to get the angle of incidence. Fission track lengths were measured for same angle of incidence. In all 500 track lengths were measured and plot for mass distribution for fission fragment was obtained.(author)

  9. Fission fragment mass and angular distributions: Probes to study ...

    Indian Academy of Sciences (India)

    In the following discussion, we shall attempt to broadly classify the nuclear landscape. (what we ... need for extra push energy (excess energy over the Coulomb barrier) to achieve fusion. It ... τM (∼ 5 × 10−21 s) of mass degree of freedom. 304.

  10. Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

    Science.gov (United States)

    Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.

    2018-03-01

    The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236-246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the Born-Oppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.

  11. Fission fragment mass distribution in the 13C+182W and 176Yb reactions

    International Nuclear Information System (INIS)

    Ramachandran, K.; Hinde, D.J.; Dasgupta, M.; Williams, E.; Wakhle, A.; Luong, D.H.; Evers, M.; Carter, I.P.; Das, S.

    2014-01-01

    Fission fragment mass distributions have been measured for many systems and found to be asymmetric in the fission of nuclei with nucleon number A in the range 228-258 and proton number Z in the range 90-100. For lighter systems, it has been observed that fission fragment mass distributions are usually symmetric. At high excitation energies the shell effects are expected to vanish and the nuclei are expected to behave like a charged liquid drop; hence, only symmetric fission is expected for all the nuclei. Even after much experimental and theoretical work in this field, the rate of damping of shell effects with excitation energy is not well known. This abstract reports our measurements with 13 C beams on 182 W and 176 Yb targets

  12. Formation of fission-fragment mass distribution for nuclei lighter than thorium

    International Nuclear Information System (INIS)

    Itkis, M.G.; Mul'gin, S.I.; Rusanov, A.Y.; Okolovich, A.N.; Smirenkin, G.N.

    1986-01-01

    A phenomenological approach to description of fission-fragment mass distribution Y(M) for nuclei in the vicinity of Pb is developed and used to extract from the experimental Y(M) data the nuclear deformation potential energy V(M) and its components: the macroscopic (liquid-drop) part and the shell correction in the transition state. The results of the analysis are compared with the theoretically obtained V(M) and Y(M). The three-hump fragment-mass distributions observed in Ra fission are satisfactorily described within the framework of the approach developed. The properties of the symmetric and asymmetric fission valleys and the related Y(M) components are discussed

  13. Observed mass distribution of spontaneous fission fragments from samples of lime - an SSNTD study

    CERN Document Server

    Paul, D; Ghose, D; Sastri, R C

    1999-01-01

    SSNTD is one of the most commonly used detectors in the studies involving nuclear phenomena. The ease of registration of the presence of alpha particles and fission fragments has made it particularly suitable in studies where stable long exposures are needed to extract reliable information. Studies on the presence of alpha emitting nuclides in the environment assume importance since they are found to be carcinogenic. Lime samples from Silchar in Assam of Eastern India have shown the presence of spontaneous fission fragments besides alphas. In the present study we look at the ratio of the average mass distribution of these fission fragments, that gives us an indication of the presence of the traces of transuranic elements.

  14. Langevin description of mass distributions of fragments originating from the fission of excited nuclei

    International Nuclear Information System (INIS)

    Vanin, D.V.; Nadtochy, P.N.; Adeev, G.D.; Kosenko, G.I.

    2000-01-01

    A stochastic approach to fission dynamics is proposed. The approach, which is based on Langevin equations, is used to calculate the mass distributions of fragments originating from the fission of excited nuclei. The effect of viscosity and light-particle emission on the variance of mass distributions is studied. The results of the calculations based on the above approach reveal that, in order to obtain a simultaneous description of mass-distribution parameters and the multiplicities of prescission particles, it is necessary to use sufficiently large values of nuclear viscosity both for the one-body and for the two-body viscosity mechanism, anomalously large values of the viscosity coefficient being required in the latter case

  15. Influence of mass-asymmetry and ground state spin on fission fragment angular distributions

    International Nuclear Information System (INIS)

    Thomas, R.G.; Biswas, D.C.; Saxena, A.; Pant, L.M.; Nayak, B.K.; Vind, R.P.; Sahu, P.K.; Sinha, Shrabani; Choudhury, R.K.

    2001-01-01

    The strong influence of the target or/and projectile ground state spin on the anomalously large anisotropies of fission fragments produced in the heavy-ion induced fission of actinide targets were reported earlier. Interestingly, all those systems studied were having a mass asymmetry greater than the Businaro-Gallone critical asymmetry and hence the presence of pre-equilibrium fission was unambiguously ruled out. The observed anisotropies were successfully explained using the ECD-K-States model. It is of interest to know the influence of the target/projectile ground state spin on systems having an entrance channel mass asymmetry less than the critical value where pre-equilibrium fission cannot be ignored. With this motivation we performed measurements of fission fragment angular distributions of the 16 O+ 235 U (spin=7/2) system

  16. Mass distribution and multiple fragmentation events in high energy cluster-cluster collisions: evidence for a predicted phase transition

    International Nuclear Information System (INIS)

    Farizon, B.; Farizon, M.; Gaillard, M.J.; Genre, R.; Louc, S.; Martin, J.; Senn, G.; Scheier, P.; Maerk, T.D.

    1996-09-01

    Fragment size distributions including multiple fragmentation events have been measured for high energy H 25 + cluster ions (60 keV/amu) colliding with a neutral C 60 target. In contrast to earlier collision experiments with a helium target the present studies do not show a U-shaped fragment mass distribution, but a single power-law falloff with increasing fragment mass. This behaviour is similar to what is known for the intermediate regime in nuclear collision physics and thus confirms a recently predicted scaling from nuclear to molecular collisions

  17. Monte Carlo simulation for fragment mass and kinetic energy distributions from the neutron-induced fission of 235U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Saettone, E.

    2007-01-01

    The mass and kinetic energy distribution of nuclear fragments from the thermal neutron-induced fission of 235 U have been studied using a Monte Carlo simulation. Besides reproducing the pronounced broadening on the standard deviation of the final fragment kinetic energy distribution (σ e (m)) around the mass number m = 109, our simulation also produces a second broadening around m = 125 that is in agreement with the experimental data obtained by Belhafaf et al. These results are a consequence of the characteristics of the neutron emission, the variation in the primary fragment mean kinetic energy, and the yield as a function of the mass. (Author)

  18. Monte Carlo simulation for fragment mass and kinetic energy distributions from the neutron-induced fission of {sup 235}U

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Saettone, E. [Facultad de Ciencias, Universidad Nacional de lngenieria, Av. Tupac Amaru 210, Apartado 31-139, Lima (Peru)

    2007-07-01

    The mass and kinetic energy distribution of nuclear fragments from the thermal neutron-induced fission of {sup 235}U have been studied using a Monte Carlo simulation. Besides reproducing the pronounced broadening on the standard deviation of the final fragment kinetic energy distribution ({sigma}{sub e}(m)) around the mass number m = 109, our simulation also produces a second broadening around m = 125 that is in agreement with the experimental data obtained by Belhafaf et al. These results are a consequence of the characteristics of the neutron emission, the variation in the primary fragment mean kinetic energy, and the yield as a function of the mass. (Author)

  19. Effects of Neutron Emission on Fragment Mass and Kinetic Energy Distribution from Thermal Neutron-Induced Fission of 235U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Saetone, E.

    2007-01-01

    The mass and kinetic energy distribution of nuclear fragments from thermal neutron-induced fission of 235 U(n th ,f) have been studied using a Monte-Carlo simulation. Besides reproducing the pronounced broadening in the standard deviation of the kinetic energy at the final fragment mass number around m = 109, our simulation also produces a second broadening around m = 125. These results are in good agreement with the experimental data obtained by Belhafaf et al. and other results on yield of mass. We conclude that the obtained results are a consequence of the characteristics of the neutron emission, the sharp variation in the primary fragment kinetic energy and mass yield curves. We show that because neutron emission is hazardous to make any conclusion on primary quantities distribution of fragments from experimental results on final quantities distributions

  20. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of 234U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Lobato, I.

    2008-01-01

    The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  1. Influence of angular momentum on fission fragment mass distribution: Interpretation within Langevin dynamics

    International Nuclear Information System (INIS)

    Ryabov, E.G.; Karpov, A.V.; Adeev, G.D.

    2006-01-01

    Dependence of fission fragments mass distribution on the angular momentum within Langevin dynamics is studied. The calculations are performed in the framework of the rotating temperature-dependent finite-range liquid drop model. The calculations are done for the five nuclei, representing heavy fissioning nuclei, medium fissioning nuclei and light fissioning one with the angular momentum varied in the wide range from l=0 to l=70-bar . The dependence coefficients dσ M 2 /dl 2 for the investigated nuclei are extracted. The comparison of the extracted values with the experimental data reveals a good agreement for all the cases (the heavy, medium, and light fissioning nuclei). It is found out that the obtained dependence of σ M 2 on l can be explained with the help of temperature at scission as a function of l. The latter dependence is determined by dependence of the mean prescission neutron multiplicity on l. The analysis of this dependence is done as a competition between fission process and neutron evaporation. 'Remembering of the former large fluctuations of mass asymmetry coordinate during descent from the saddle to scission' is considered. It is shown that the 'remembering effect' takes place, but does not play a crucial role for the investigated dependence of σ M 2 on l

  2. Neutron emission effects on fragment mass and kinetic energy distribution from fission of 239Pu induced by thermal neutrons

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Lobato, I.

    2010-01-01

    The average of fragment kinetic energy (E-bar sign*) and the multiplicity of prompt neutrons (ν(bar sign)) as a function of fragment mass (m*), as well as the fragment mass yield (Y(m*)) from thermal neutron-induced fission of 239 Pu have been measured by Tsuchiya et al.. In that work the mass and kinetic energy are calculated from the measured kinetic energy of one fragment and the difference of time of flight of the two complementary fragments. However they do not present their results about the standard deviation σ E *(m*). In this work we have made a numerical simulation of that experiment which reproduces its results, assuming an initial distribution of the primary fragment kinetic energy (E(A)) with a constant value of the standard deviation as function of fragment mass (σ E (A)). As a result of the simulation we obtain the dependence σ E *(m*) which presents an enhancement between m* = 92 and m* = 110, and a peak at m* = 121.

  3. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of {sup 234}U

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Lobato, I. [Facultad de Ciencias, Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Apartado Postal 31-139, Lima (Peru)]. e-mail: mmontoya@ipen.gob.pe

    2008-07-01

    The standard deviation of the final kinetic energy distribution ({sigma}{sub e}) as a function of mass of final fragments (m) from low energy fission of {sup 234}U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution ({sigma}{sub E}) as a function of primary fragment mass (A). The second peak is attributed to a real peak on {sigma}{sub E}(A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on {sigma}{sub E}(A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on {sigma}{sub e} (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the {sigma}{sub E} (A) curve, and the observed peaks on {sigma}{sub e} (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  4. Percolation-fission model study of the fragment mass distribution for the 1 GeV proton induced reaction

    International Nuclear Information System (INIS)

    Katsuma, Masahiko; Kobayashi, Hiroshi; Sawada, Tetsuo; Sasa, Toshinobu

    2005-01-01

    The 1 GeV proton induced reaction on 208 Pb targets is analyzed by using the percolation model combined with the Atchison fission model. The fragment mass distribution and the isotopic production cross sections obtained from our model are compared with the experimental data. The trends of the fragment mass distribution for the 1 GeV proton induced reaction can be reproduced by our calculation in some degree. The order of magnitude for the calculated isotopic production cross sections at the calculated peak positions is similar to that of the experimental peak values. The calculated peak positions of the isotopic production cross sections are shifted to the heavier region than those of the experimental data. (author)

  5. A semi-empirical formula on the pre-neutron-emission fragment mass distribution in nuclear fission

    International Nuclear Information System (INIS)

    Wang Fucheng; Hu Jimin

    1988-03-01

    A 5-Gauss semi-empirical formula on the pre-neutron-emission fragment mass distribution is given. The absolute standard deviation and maximum departure between calculated values and experimental data for (n,f) and (n,n'f) fission reactions from 232 Th to 245 Cm are approximately 0.4% and 0.8%, respectively. The error will get bigger if the formula is used at higher excitation energies

  6. Mass and kinetic-energy distributions of fragments formed in the heavy-ion-induced fission of 208Po

    International Nuclear Information System (INIS)

    Cuninghame, J.G.; Goodall, J.A.B.

    1980-01-01

    Fission fragments following the decay of a 208 Po compound nucleus have been observed by using radiochemical and particle-counting techniques. The (α+ 204 Pb), ( 12 C+ 196 Pt) and ( 16 O+ 192 Os) reactions were studied at two or three bombarding energies, covering overlapping ranges of excitation energies. - Radiochemical separations of As, Br, Y, Nb, Tc, Ag, Sb and I isotopes were made from catcher foils sandwiching isotopic targets, and their isotopic yield distributions determined. The distributions are used to estimate the average number of neutrons associated with each fission event, including neutrons emitted before and after fission. - Prompt coincidence measurements of fragments are used to derive the overall mass and kinetic-energy distributions of primary fragments, taking into account the effects of pre- and post-fission neutron emission. The mass distributions are well fitted by the statistical theory, at a temperature corresponding to an excitation about 10 MeV above that at the saddle point. No evidence is found for an increase of kinetic-energy with increasing angular momentum of the compound nucleus. (author)

  7. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    Science.gov (United States)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  8. Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the 18O+232Th reaction

    Directory of Open Access Journals (Sweden)

    R. Léguillon

    2016-10-01

    Full Text Available It is shown that the multinucleon transfer reactions is a powerful tool to study fission of exotic neutron-rich actinide nuclei, which cannot be accessed by particle-capture or heavy-ion fusion reactions. In this work, multinucleon transfer channels of the 18O+232Th reaction are used to study fission of fourteen nuclei 231,232,233,234Th, 232,233,234,235,236Pa, and 234,235,236,237,238U. Identification of fissioning nuclei and of their excitation energy is performed on an event-by-event basis, through the measurement of outgoing ejectile particle in coincidence with fission fragments. Fission fragment mass distributions are measured for each transfer channel, in selected bins of excitation energy. In particular, the mass distributions of 231,234Th and 234,235,236Pa are measured for the first time. Predominantly asymmetric fission is observed at low excitation energies for all studied cases, with a gradual increase of the symmetric mode towards higher excitation energy. The experimental distributions are found to be in general agreement with predictions of the fluctuation–dissipation model.

  9. Mass distribution of fission-like fragments formed in 20Ne + 165Ho system at Elab≈ 8.2 MeV/A

    International Nuclear Information System (INIS)

    Singh, D.; Linda, Sneha Bharti; Giri, Pankaj K.

    2017-01-01

    In the present work, an attempt has been made to study CFF and IFF in 20 Ne + 165 Ho system at projectile energy ≈ 8.2 MeV/A. Twelve fission like fragments (FLF) produced through complete fusion-fission (CFF) and/or incomplete fusion-fission (IFF) in the present system have been identified. The production cross-sections of identified fission like fragments have been measured and the mass distribution of fission like fragments studied

  10. Measurement of Fragment Mass Distributions in Neutron-induced Fission of 238U and 232Th at Intermediate Energies

    International Nuclear Information System (INIS)

    Simutkin, V.D.

    2008-01-01

    Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the 238 U(n,f) and 232 Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both 238 U and 232 Th. Up to now, the intermediate energy measurements have been performed for 238 U only, and there are no data for the 232 Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the 232 Th(n,f) and 238 U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

  11. Angular distributions of intermediate mass fragments emitted in 30 MeV/u 40Ar induced reactions

    International Nuclear Information System (INIS)

    Gou Quanbu; Zhu Yongtai; Xu Hushan; Wei Zhiyong; Lu Jun; Zhang Yuhu; Wang Qi; Li Songlin; Wu Zhongli

    1999-01-01

    The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40 Ar + 58,64 Ni and 115 In reactions over an angular range of 5 degree-140 degree have been measured. In different angular region an exponential distribution function dσ/dΩ = N exp(-θ/α) was used to fit the measured angular distributions. The decay factor α which can be connected with the interaction time τ and the factor N which is related to the intensity of the emission sources have been extracted. The relationship of α(Z) and N(Z) with Z for different reaction systems and different angular regions has been discussed. The different behavior of dσ/dΩ, α(Z), and N(Z) for the three studied reaction systems exists mainly in the middle and backward angular regions. The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed

  12. Velocity distribution of fragments of catastrophic impacts

    Science.gov (United States)

    Takagi, Yasuhiko; Kato, Manabu; Mizutani, Hitoshi

    1992-01-01

    Three dimensional velocities of fragments produced by laboratory impact experiments were measured for basalts and pyrophyllites. The velocity distribution of fragments obtained shows that the velocity range of the major fragments is rather narrow, at most within a factor of 3 and that no clear dependence of velocity on the fragment mass is observed. The NonDimensional Impact Stress (NDIS) defined by Mizutani et al. (1990) is found to be an appropriate scaling parameter to describe the overall fragment velocity as well as the antipodal velocity.

  13. Angular distributions of evaporated particles, fission and intermediate-mass fragments: on the search for consistent models

    International Nuclear Information System (INIS)

    Alexander, J.M.

    1987-01-01

    During the last two years there has been a true cacophony concerning the meaning of experimental angular distributions for fission and fission-like fragments. The heavily used, saddle-point, transition-state model has been shown to be of limited value for high-spin systems, and a wide variety of proposals has appeared often with mutual inconsistencies and conflicting views. Even though equilibrium statistical models for fragment emission and particle evaporation must have a very close kinship, this relationship, often left as murky, has now come onto center stage for understanding reactions at ≥ 100 MeV. Basic questions concern the nature of the decision-point configurations, their degrees of freedom, the role of deformation and the relevant moments of inertia. This paper points out serious inconsistencies in several recent scission-point models and discusses conditions for applicability of saddle-point and scission-point approaches

  14. Excitation energy dependence of fragment-mass distributions from fission of 180,190Hg formed in fusion reactions of 36Ar + 144,154Sm

    Directory of Open Access Journals (Sweden)

    K. Nishio

    2015-09-01

    Full Text Available Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E⁎(Hg180=33–66 MeV and E⁎(Hg190=48–71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A¯L/A¯H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A¯L/A¯H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.

  15. Fission-fragment mass distribution and estimation of the cluster emission probability in the γ + 232Th and 181Ta reactions

    International Nuclear Information System (INIS)

    Karamyan, S.A.; Adam, J.; Belov, A.G.; Chaloun, P.; Norseev, Yu.V.; Stegajlov, V.I.

    1997-01-01

    Fission-fragment mass distribution has been measured by the cumulative yields of radionuclides detected in the 232 Th(γ,f)-reaction at the Bremsstrahlung endpoint energies of 12 and 24 MeV. The yield upper limits have been estimated for the light nuclei 24 Na, 28 Mg, 38 S etc. at the Th and Ta targets exposure to the 24 MeV Bremsstrahlung. The results are discussed in terms of the multimodal fission phenomena and cluster emission >from a deformed fissioning system or from a compound nucleus

  16. Mass spectrometry for fragment screening.

    Science.gov (United States)

    Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

    2017-11-08

    Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  17. Measurement of Fragment Mass Distributions in Neutron-induced Fission of {sup 238}U and {sup 232}Th at Intermediate Energies

    Energy Technology Data Exchange (ETDEWEB)

    Simutkin, V.D. [Uppsala University, P.O Box 525, SE-751 20 Uppsala (Sweden)

    2008-07-01

    Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the {sup 238}U(n,f) and {sup 232}Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both {sup 238}U and {sup 232}Th. Up to now, the intermediate energy measurements have been performed for {sup 238}U only, and there are no data for the {sup 232}Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

  18. Fission fragment distributions within dynamical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, K. [Institute of Nuclear, Physics Polish Academy of Sciences, Krakow (Poland); Nadtochy, P.N. [Omsk State Technical University, Omsk (Russian Federation); Ryabov, E.G.; Adeev, G.D. [Omsk State University, Physics Department, Omsk (Russian Federation)

    2017-04-15

    The review covers recent developments and achievements in the dynamical description of fission process at high excitation energy. It is shown that the dynamical approach based on multidimensional Langevin equations combined with the statistical description of nuclear decay by particles evaporation is capable of fairly well describing the formation of fission fragment mass-energy, charge, and angular distributions of fission fragments in coincidence with the pre- and post-scission particle emission. The final yields of fission and evaporation residues channels products could be obtained. The detailed description of fission dynamics allows studying different stages of fission process, indicating the most important ingredients governing fission process and studying in detail such fundamental nuclear properties as nuclear viscosity and fission timescale. The tasks and perspectives of multidimensional dynamical approach are also discussed. (orig.)

  19. Fission Fragment Mass Distributions and Total Kinetic Energy Release of 235-Uranium and 238-Uranium in Neutron-Induced Fission at Intermediate and Fast Neutron Energies

    Energy Technology Data Exchange (ETDEWEB)

    Duke, Dana Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-12

    This Ph.D. dissertation describes a measurement of the change in mass distributions and average total kinetic energy (TKE) release with increasing incident neutron energy for fission of 235U and 238U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, En, changes the division of energy release in the resulting fission fragments, however, the details of energy partitioning remain ambiguous because the nucleus is a many-body quantum system. Creating a full theoretical model is difficult and experimental data to validate existing models are lacking. Additional fission measurements will lead to higher-quality models of the fission process, therefore improving applications such as the development of next-generation nuclear reactors and defense. This work also paves the way for precision experiments such as the Time Projection Chamber (TPC) for fission cross section measurements and the Spectrometer for Ion Determination in Fission (SPIDER) for precision mass yields.

  20. Charge distribution in the ternary fragmentation of {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Kannan, M.T.; Balasubramaniam, M. [Bharathiar University, Department of Physics, Coimbatore (India)

    2017-08-15

    We present here, for the first time, a study on ternary fragmentation charge distribution of {sup 252}Cf using the convolution integral method and the statistical theory. The charge distribution for all possible charge combinations of a ternary breakup are grouped as a bin containing different mass partitions. Different bins corresponding to various third fragments with mass numbers from A{sub 3} = 16 to 84 are identified with the available experimental masses. The corresponding potential energy surfaces are calculated using the three cluster model for the two arrangements A{sub 1} + A{sub 2} + A{sub 3} and A{sub 1} + A{sub 3} + A{sub 2}. The ternary fragmentation yield values are calculated for the ternary combination from each bin possessing minimum potential energy. The yields of the resulting ternary combinations as a function of the charge numbers of the three fragments are analyzed for both the arrangements. The calculations are carried out at different excitation energies of the parent nucleus. For each excitation energy the temperature of the three fragments are iteratively computed conserving the total energy. The distribution of fragment temperatures corresponding to different excitation energies for some fixed third fragments are discussed. The presence of the closed shell nucleus Sn in the favourable ternary fragmentation is highlighted. (orig.)

  1. Jet mass dependence of fragmentation in positron-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Urmossy, K. [Shandong University, School of Physics and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Jinan, Shandong (China)

    2017-02-15

    We propose the characterization of fragmentation functions by the energy fraction x a hadron takes away from the energy of the jet measured in the frame co-moving with the jet. Besides, we propose the usage of the jet mass as the fragmentation scale Q. We show that these two Lorentz-invariant variables emerge naturally in a microcanonical ensemble with conserved four-momentum. Then, we construct a statistical hadronisation model, in which, two features of the hadronic final states in various high-energy reactions (power law spectra and negative-binomial multiplicity distributions) can be connected simply. Finally, we analyse the scale dependence of the parameters of the model (power of the spectrum and mean energy per hadron) in the φ{sup 3} theory. Fitting fragmentation functions in diffractive positron-proton collisions, we obtain a prediction for the jet mass dependence of the hadron multiplicity distribution inside jets. (orig.)

  2. SSNTD study of the probable influence of alpha activity on the mass distribution of sup 2 sup 5 sup 2 Cf fission fragments

    CERN Document Server

    Paul, D; Sastri, R C; Ghose, D

    1999-01-01

    The SSNTD has come a long way in its application for the study of nuclear phenomena. Spontaneous fission of transuranic elements is one such phenomena wherein use of SSNTD offers easy registration of the signature of the fission fragments. The object of the present study is to explore whether any one of the track parameters such as the diameter can be used to estimate the atomic mass ratios of the spontaneous fission fragments. The spontaneous fission data from sup 2 sup 5 sup 2 Cf recorded almost at the end of one and four half-life periods for alpha decay are analysed, taking a plot of the number of tracks versus the track diameter. From these plots it is seen that initially, when significant alpha activity of sup 2 sup 5 sup 2 Cf persists, the fission fragments appear to cluster into two predominant groups as indicated by two peaks. The ratio of the diameters at these peak positions appear to be related to the ratio of average mass numbers of the light and heavy groups of fission fragments. However, absenc...

  3. Phenomenological relation between distribution and fragmentation functions

    International Nuclear Information System (INIS)

    Ma Boqiang; Schmidt, Ivan; Soffer, Jacques; Yang Jianjun

    2002-01-01

    We study the relation between the quark distribution function q(x) and the fragmentation function D q (z) based on a general form D q (x)=C(z)z α q(z) for valence and sea quarks. By adopting two known parametrizations of quark distributions for the proton, we find three simple options for the fragmentation functions that can provide a good description of the available experimental data on proton production in e + e - inelastic annihilation. These three options support the revised Gribov-Lipatov relation D q (z)=zq(z) at z→1, as an approximate relation for the connection between distribution and fragmentation functions. The three options differ in the sea contributions and lead to distinct predictions for antiproton production in the reaction p+p→p-bar+X, thus they are distinguishable in future experiments at RHIC-BNL

  4. The mass and radius of exotic fragment

    International Nuclear Information System (INIS)

    Schutz, Y.

    1989-01-01

    Recent developments in the study of exotic nuclei are presented. A method to measure the ground-state mass is presented and the results are compared with standard models. Total reaction cross section measurements for exotic nuclei are also presented and interpreted in terms of matter distribution in the nucleus

  5. Element Distribution and Multiplicity of Heavy Fragments

    CERN Multimedia

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  6. Possible mass distributions in the nebulae of other solar systems

    International Nuclear Information System (INIS)

    Brown, W.K.

    1987-01-01

    The supernova shell fragmentation model of solar system formation - previously shown to be successful in describing the mass distribution of our solar system - is used to calculate the mass distributions of other solar nebulae. (Auth.)

  7. On widths of mass distributions in statistical theory of fission

    International Nuclear Information System (INIS)

    Volkov, N.G.; Emel'yanov, V.M.

    1979-01-01

    The process of nucleon tunneling from one fragment to another near the point of the compoUnd-nucleus fragmentation has been studied in the model of a two-center oscillator. The effect of the number of transferred nucleons on the mass distribution of fragments is estimated. Sensitivity of the model to the form of the single-particle potential, excitation eneraies and deformation of fragments is examined. The calculations performed show that it is possible to calculate the mass distributions at the point of fragment contact in the statistical fission model, taking account of the nucleon exchange between fragments

  8. Quantification and micron-scale imaging of spatial distribution of trace beryllium in shrapnel fragments and metallurgic samples with correlative fluorescence detection method and secondary ion mass spectrometry (SIMS).

    Science.gov (United States)

    Abraham, J L; Chandra, S; Agrawal, A

    2014-11-01

    Recently, a report raised the possibility of shrapnel-induced chronic beryllium disease from long-term exposure to the surface of retained aluminum shrapnel fragments in the body. Since the shrapnel fragments contained trace beryllium, methodological developments were needed for beryllium quantification and to study its spatial distribution in relation to other matrix elements, such as aluminum and iron, in metallurgic samples. In this work, we developed methodology for quantification of trace beryllium in samples of shrapnel fragments and other metallurgic sample-types with main matrix of aluminum (aluminum cans from soda, beer, carbonated water and aluminum foil). Sample preparation procedures were developed for dissolving beryllium for its quantification with the fluorescence detection method for homogenized measurements. The spatial distribution of trace beryllium on the sample surface and in 3D was imaged with a dynamic secondary ion mass spectrometry instrument, CAMECA IMS 3f secondary ion mass spectrometry ion microscope. The beryllium content of shrapnel (∼100 ppb) was the same as the trace quantities of beryllium found in aluminum cans. The beryllium content of aluminum foil (∼25 ppb) was significantly lower than cans. SIMS imaging analysis revealed beryllium to be distributed in the form of low micron-sized particles and clusters distributed randomly in X-Y- and Z dimensions, and often in association with iron, in the main aluminum matrix of cans. These observations indicate a plausible formation of Be-Fe or Al-Be alloy in the matrix of cans. Further observations were made on fluids (carbonated water) for understanding if trace beryllium in cans leached out and contaminated the food product. A direct comparison of carbonated water in aluminum cans and plastic bottles revealed that beryllium was below the detection limits of the fluorescence detection method (∼0.01 ppb). These observations indicate that beryllium present in aluminum matrix was either

  9. Quantification and micron-scale imaging of spatial distribution of trace beryllium in shrapnel fragments and metallurgic samples with correlative fluorescence detection method and secondary ion mass spectrometry (SIMS)

    Science.gov (United States)

    Abraham, Jerrold L.; Chandra, Subhash; Agrawal, Anoop

    2014-01-01

    Recently, a report raised the possibility of shrapnel-induced chronic beryllium disease (CBD) from long-term exposure to the surface of retained aluminum shrapnel fragments in the body. Since the shrapnel fragments contained trace beryllium, methodological developments were needed for beryllium quantification and to study its spatial distribution in relation to other matrix elements, such as aluminum and iron, in metallurgic samples. In this work, we developed methodology for quantification of trace beryllium in samples of shrapnel fragments and other metallurgic sample-types with main matrix of aluminum (aluminum cans from soda, beer, carbonated water, and aluminum foil). Sample preparation procedures were developed for dissolving beryllium for its quantification with the fluorescence detection method for homogenized measurements. The spatial distribution of trace beryllium on the sample surface and in 3D was imaged with a dynamic secondary ion mass spectrometry (SIMS) instrument, CAMECA IMS 3f SIMS ion microscope. The beryllium content of shrapnel (~100 ppb) was the same as the trace quantities of beryllium found in aluminum cans. The beryllium content of aluminum foil (~25 ppb) was significantly lower than cans. SIMS imaging analysis revealed beryllium to be distributed in the form of low micron-sized particles and clusters distributed randomly in X-Y-and Z dimensions, and often in association with iron, in the main aluminum matrix of cans. These observations indicate a plausible formation of Be-Fe or Al-Be alloy in the matrix of cans. Further observations were made on fluids (carbonated water) for understanding if trace beryllium in cans leached out and contaminated the food product. A direct comparison of carbonated water in aluminum cans and plastic bottles revealed that beryllium was below the detection limits of the fluorescence detection method (~0.01 ppb). These observations indicate that beryllium present in aluminum matrix was either present in an

  10. The size distributions of fragments ejected at a given velocity from impact craters

    Science.gov (United States)

    O'Keefe, John D.; Ahrens, Thomas J.

    1987-01-01

    The mass distribution of fragments that are ejected at a given velocity for impact craters is modeled to allow extrapolation of laboratory, field, and numerical results to large scale planetary events. The model is semi-empirical in nature and is derived from: (1) numerical calculations of cratering and the resultant mass versus ejection velocity, (2) observed ejecta blanket particle size distributions, (3) an empirical relationship between maximum ejecta fragment size and crater diameter, (4) measurements and theory of maximum ejecta size versus ejecta velocity, and (5) an assumption on the functional form for the distribution of fragments ejected at a given velocity. This model implies that for planetary impacts into competent rock, the distribution of fragments ejected at a given velocity is broad, e.g., 68 percent of the mass of the ejecta at a given velocity contains fragments having a mass less than 0.1 times a mass of the largest fragment moving at that velocity. The broad distribution suggests that in impact processes, additional comminution of ejecta occurs after the upward initial shock has passed in the process of the ejecta velocity vector rotating from an initially downward orientation. This additional comminution produces the broader size distribution in impact ejecta as compared to that obtained in simple brittle failure experiments.

  11. Proton fragmentation functions considering finite-mass corrections

    Energy Technology Data Exchange (ETDEWEB)

    Moosavi Nejad, S.M. [Yazd University, Faculty of Physics, Yazd (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of); Soleymaninia, M. [Payame Noor Universtiy, Department of Physics, Tehran (Iran, Islamic Republic of); Maktoubian, A. [Yazd University, Faculty of Physics, Yazd (Iran, Islamic Republic of)

    2016-10-15

    We present new sets of proton fragmentation functions (FFs) describing the production of protons from the gluon and each of the quarks, obtained by the NLO QCD fits to all relevant data sets of single-inclusive electron-positron annihilation. Specifically, we determine their uncertainties using the Gaussian method for error estimation. Our analysis is in good agreement with the e{sup +}e{sup -} annihilation data. We also include finite-mass effects of the proton in our calculations, a topic to which very little attention is paid in the literature. Proton mass effects turn out to be appreciable for gluon and light quark FFs. The inclusion of finite-mass effects tends to improve the overall description of the data by reducing the minimized χ{sup 2} values significantly. As an application, we apply the extracted FFs to make predictions for the scaled-energy distribution of protons inclusively produced in top quark decays at next-to-leading order, relying on the universality and scaling violations of FFs. (orig.)

  12. Research at the fragment mass analyser at ATLAS

    International Nuclear Information System (INIS)

    Davids, C.N.; Back, B.; Bearden, I.G.

    1993-01-01

    The experimental program at the Fragment Mass Analyzer (FMA) at the ATLAS heavy ion accelerator of the Argonne National Laboratory is described. The brief description and operational properties of the FMA are presented. The highest mass resolution obtained with the FMA is 525/1. Some experimental results are presented. 5 refs., 7 figs

  13. On angular distribution of nucleus fission fragments by fast neutrons

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1987-01-01

    Evaluation of amplitudes of quadrupole and hexadecapole components of angular distribution of nucleus fission fragments by neutrons with the energies E n < or approx. 6 MeV is conducted. Stability of this amplitude to permeability optical coefficient variations for neutrons is revealed. It is shown, that the ratio of these amplitudes as well as the character of their dependence on the target nucleus orientation degree are sensitive to the type of fission probability distribution along K projection if fissile nucleus J spin to the fragment scattering axis. This sensitivity may be used for fragment angular distribution anisotropy formation statistical model verification

  14. Fragment size distribution in viscous bag breakup of a drop

    Science.gov (United States)

    Kulkarni, Varun; Bulusu, Kartik V.; Plesniak, Michael W.; Sojka, Paul E.

    2015-11-01

    In this study we examine the drop size distribution resulting from the fragmentation of a single drop in the presence of a continuous air jet. Specifically, we study the effect of Weber number, We, and Ohnesorge number, Oh on the disintegration process. The regime of breakup considered is observed between 12 phase Doppler anemometry. Both the number and volume fragment size probability distributions are plotted. The volume probability distribution revealed a bi-modal behavior with two distinct peaks: one corresponding to the rim fragments and the other to the bag fragments. This behavior was suppressed in the number probability distribution. Additionally, we employ an in-house particle detection code to isolate the rim fragment size distribution from the total probability distributions. Our experiments showed that the bag fragments are smaller in diameter and larger in number, while the rim fragments are larger in diameter and smaller in number. Furthermore, with increasing We for a given Ohwe observe a large number of small-diameter drops and small number of large-diameter drops. On the other hand, with increasing Oh for a fixed We the opposite is seen.

  15. Fission fragment mass and angular distributions

    Indian Academy of Sciences (India)

    2015-07-22

    Jul 22, 2015 ... Synthesis of heavy and superheavy elements is severely hindered by fission and fission-like processes. The probability of these fission-like, non-equilibrium processes strongly depends on the entrance channel parameters. This article attempts to summarize the recent experimental findings and classify the ...

  16. Mass spectrometry with ionization induced by 252Cf fission fragments

    International Nuclear Information System (INIS)

    Sysoev, A.A.; Artaev, V.B.

    1991-01-01

    The review deals with mass-spectrometry with ionization induced by 252 Cf fission fragments. Equipment and technique of the analysis, analytic possibilities of the method are considered. The method permits to determine molecular masses of large nonvolatile biological molecules. The method is practically nondestructive, it possesses a high resolution over the depth and surface, which permits to use it for the analysis of surface of semiconductors, dielectrics, catalysts, for the study of formation kinetics of complex unstable molecules on the surface

  17. About total kinetic energy distribution between fragments of binary fission

    International Nuclear Information System (INIS)

    Khugaev, A.V.; Koblik, Yu.N.; Pikul, V.P.; Ioannou, P.; Dimovasili, E.

    2002-01-01

    At the investigation of binary fission reactions one of the main characteristic of process is total kinetic energy (TKE) of fission fragments and it distribution between them. From the values of these characteristics it is possible to extract the information about structure of fission fragments in the break up point of initial fissionable nuclear system. In our work TKE dependence from the deformation parameters of shape and density distribution of charge in the fission fragments are investigated. In the end of paper some generalizations of obtaining results are carried out and presented in the form of tables and figures

  18. Primary Distributions of Nuclear Charge for Fission-Fragment Masses 132, 134, 136 and 137 from Thermal Fission of U{sup 235}; Repartition Primaire de la Charge Nucleaire pour les Fragments de Masse 132, 134, 136 et 137, Provenant de la Fission de {sup 235}U par Neutrons Thermiques; 041f 0415 0420 0414 ; Distribuciones Primarias de las Cargas Nucleares de los Fragmentos de Masa 132, 134, 136 y 137, Resultantes de la Fision del {sup 235}U por Neutrones Termicos

    Energy Technology Data Exchange (ETDEWEB)

    Konecny, E.; Opower, H.; Guenther, H.; Goebel, H. [Physik-Department der Technischen Hochschule Muenchen, Munich and II. Physikalisches Institut der Justus Liebig-Universitaet Giessen, Federal Republic of Germany (Germany)

    1965-07-15

    By a mass spectrometer fission fragments from thermal fission of U{sup 235} are exactly separated with respect to mass and kinetic energy within a time of 10{sup -6} s after fission. The separated fragments are caught in a {beta}-sensitive Ilford G 5 emulsion that is located in the focal plane of the spectrometer. Development of the irradiated emulsions is carried out, if possible, after a time long compared with the longest half-life of the regarded decay chain. Half-lives of days or longer are not taken into account, but corrections can be easily made for them. After development of the emulsions all beta tracks emerging from the end of every fission-fragment track can be seen under the microscope. The possibility of correlating every single {beta}-track with a particular fission-fragment track allows the evaluation of the number n(x) of fission fragments possessing x {beta}-tracks, thus giving not only the mean chain length but also the {beta}-particle distribution. As the stable end product of each decay chain is known, this {beta}-distribution is an exact image of the primary nuclear charge distribution. In the measurements done up to now only {beta}-particles emitted into the half solid angle formed by the emulsion plate were registered, buta simple statistical calculation enables the desired 4{pi}-distribution to be evaluated. By this method {beta}-distributions at fixed kinetic energies near the mean kinetic energy of each fragment mass are given for the masses 132, 134, 136 and 137. For the lower masses 132 and 134 the neutron shell N = 82 is responsible for the most probable primary charges near 50 and 52 respectively. For M = 136 and 137 the primary charge is about 53 and 53.2. Additional approximative corrections in respect of conversion electrons (by omitting very short {beta}-tracks corresponding to very low {beta}-energies) and to delayed neutrons (for mass 137) were not very large. Similar measurements carried out directly in 4{pi}-geometry to avoid

  19. Seed-dispersal distributions by trumpeter hornbills in fragmented landscapes

    Science.gov (United States)

    Lenz, Johanna; Fiedler, Wolfgang; Caprano, Tanja; Friedrichs, Wolfgang; Gaese, Bernhard H.; Wikelski, Martin; Böhning-Gaese, Katrin

    2011-01-01

    Frugivorous birds provide important ecosystem services by transporting seeds of fleshy fruited plants. It has been assumed that seed-dispersal kernels generated by these animals are generally leptokurtic, resulting in little dispersal among habitat fragments. However, little is known about the seed-dispersal distribution generated by large frugivorous birds in fragmented landscapes. We investigated movement and seed-dispersal patterns of trumpeter hornbills (Bycanistes bucinator) in a fragmented landscape in South Africa. Novel GPS loggers provide high-quality location data without bias against recording long-distance movements. We found a very weakly bimodal seed-dispersal distribution with potential dispersal distances up to 14.5 km. Within forest, the seed-dispersal distribution was unimodal with an expected dispersal distance of 86 m. In the fragmented agricultural landscape, the distribution was strongly bimodal with peaks at 18 and 512 m. Our results demonstrate that seed-dispersal distributions differed when birds moved in different habitat types. Seed-dispersal distances in fragmented landscapes show that transport among habitat patches is more frequent than previously assumed, allowing plants to disperse among habitat patches and to track the changing climatic conditions. PMID:21177686

  20. Mass distributions in disk galaxies

    NARCIS (Netherlands)

    Martinsson, Thomas; Verheijen, Marc; Bershady, Matthew; Westfall, Kyle; Andersen, David; Swaters, Rob

    We present results on luminous and dark matter mass distributions in disk galaxies from the DiskMass Survey. As expected for normal disk galaxies, stars dominate the baryonic mass budget in the inner region of the disk; however, at about four optical scale lengths (hR ) the atomic gas starts to

  1. Scaling analysis of meteorite shower mass distributions

    DEFF Research Database (Denmark)

    Oddershede, Lene; Meibom, A.; Bohr, Jakob

    1998-01-01

    Meteorite showers are the remains of extraterrestrial objects which are captivated by the gravitational field of the Earth. We have analyzed the mass distribution of fragments from 16 meteorite showers for scaling. The distributions exhibit distinct scaling behavior over several orders of magnetude......; the observed scaling exponents vary from shower to shower. Half of the analyzed showers show a single scaling region while the orther half show multiple scaling regimes. Such an analysis can provide knowledge about the fragmentation process and about the original meteoroid. We also suggest to compare...... the observed scaling exponents to exponents observed in laboratory experiments and discuss the possibility that one can derive insight into the original shapes of the meteoroids....

  2. Native Mass Spectrometry in Fragment-Based Drug Discovery.

    Science.gov (United States)

    Pedro, Liliana; Quinn, Ronald J

    2016-07-28

    The advent of native mass spectrometry (MS) in 1990 led to the development of new mass spectrometry instrumentation and methodologies for the analysis of noncovalent protein-ligand complexes. Native MS has matured to become a fast, simple, highly sensitive and automatable technique with well-established utility for fragment-based drug discovery (FBDD). Native MS has the capability to directly detect weak ligand binding to proteins, to determine stoichiometry, relative or absolute binding affinities and specificities. Native MS can be used to delineate ligand-binding sites, to elucidate mechanisms of cooperativity and to study the thermodynamics of binding. This review highlights key attributes of native MS for FBDD campaigns.

  3. Fission profits of thorium: Distribution in charge and mass

    International Nuclear Information System (INIS)

    Guarnieri, A.A.

    1985-01-01

    It is presented the improvement of a semi-empiric model to describe behavior fo the 235 U + thermal neutrons system. The model is applied to fission of the 232 Th case reproducing the distribution of mass profits of fission products from the behavior of independent profits of fragments related the mass and charge, and the emission of prompt neutrons per fragment. (M.C.K.) [pt

  4. The neutron star mass distribution

    Energy Technology Data Exchange (ETDEWEB)

    Kiziltan, Bülent [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kottas, Athanasios; De Yoreo, Maria [Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064 (United States); Thorsett, Stephen E., E-mail: bkiziltan@cfa.harvard.edu [Department of Astronomy and Astrophysics, University of California and UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)

    2013-11-20

    In recent years, the number of pulsars with secure mass measurements has increased to a level that allows us to probe the underlying neutron star (NS) mass distribution in detail. We critically review the radio pulsar mass measurements. For the first time, we are able to analyze a sizable population of NSs with a flexible modeling approach that can effectively accommodate a skewed underlying distribution and asymmetric measurement errors. We find that NSs that have evolved through different evolutionary paths reflect distinctive signatures through dissimilar distribution peak and mass cutoff values. NSs in double NS and NS-white dwarf (WD) systems show consistent respective peaks at 1.33 M {sub ☉} and 1.55 M {sub ☉}, suggesting significant mass accretion (Δm ≈ 0.22 M {sub ☉}) has occurred during the spin-up phase. The width of the mass distribution implied by double NS systems is indicative of a tight initial mass function while the inferred mass range is significantly wider for NSs that have gone through recycling. We find a mass cutoff at ∼2.1 M {sub ☉} for NSs with WD companions, which establishes a firm lower bound for the maximum NS mass. This rules out the majority of strange quark and soft equation of state models as viable configurations for NS matter. The lack of truncation close to the maximum mass cutoff along with the skewed nature of the inferred mass distribution both enforce the suggestion that the 2.1 M {sub ☉} limit is set by evolutionary constraints rather than nuclear physics or general relativity, and the existence of rare supermassive NSs is possible.

  5. Looking for bimodal distributions in multi-fragmentation reactions

    International Nuclear Information System (INIS)

    Gulminelli, F.

    2007-01-01

    The presence of a phase transition in a finite system can be deduced, together with its order, from the form of the distribution of the order parameter. This issue has been extensively studied in multifragmentation experiments, with results that do not appear fully consistent. In this paper we discuss the effect of the statistical ensemble or sorting conditions on the form of fragment distributions, and propose a new method, which can be easily implemented experimentally, to discriminate between different fragmentation scenarios. This method, based on a re-weighting of the measured distribution to account for the experimental constraints linked to the energy deposit, is tested on different simple models, and appears to provide a powerful discrimination. (author)

  6. Native Mass Spectrometry in Fragment-Based Drug Discovery

    Directory of Open Access Journals (Sweden)

    Liliana Pedro

    2016-07-01

    Full Text Available The advent of native mass spectrometry (MS in 1990 led to the development of new mass spectrometry instrumentation and methodologies for the analysis of noncovalent protein–ligand complexes. Native MS has matured to become a fast, simple, highly sensitive and automatable technique with well-established utility for fragment-based drug discovery (FBDD. Native MS has the capability to directly detect weak ligand binding to proteins, to determine stoichiometry, relative or absolute binding affinities and specificities. Native MS can be used to delineate ligand-binding sites, to elucidate mechanisms of cooperativity and to study the thermodynamics of binding. This review highlights key attributes of native MS for FBDD campaigns.

  7. Analytical Core Mass Function (CMF) from Filaments: Under Which Circumstances Can Filament Fragmentation Reproduce the CMF?

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yueh-Ning; Hennebelle, Patrick [IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Chabrier, Gilles, E-mail: yueh-ning.lee@cea.fr [École normale supérieure de Lyon, CRAL, UMR CNRS 5574, Université de Lyon, F-69364 Lyon Cedex 07 (France)

    2017-10-01

    Observations suggest that star formation in filamentary molecular clouds occurs in a two-step process, with the formation of filaments preceding that of prestellar cores and stars. Here, we apply the gravoturbulent fragmentation theory of Hennebelle and Chabrier to a filamentary environment, taking into account magnetic support. We discuss the induced geometrical effect on the cores, with a transition from 3D geometry at small scales to 1D at large ones. The model predicts the fragmentation behavior of a filament for a given mass per unit length (MpL) and level of magnetization. This core mass function (CMF) for individual filaments is then convolved with the distribution of filaments to obtain the final system CMF. The model yields two major results. (i) The filamentary geometry naturally induces a hierarchical fragmentation process, first into groups of cores, separated by a length equal to a few filament Jeans lengths, i.e., a few times the filament width. These groups then fragment into individual cores. (ii) Non-magnetized filaments with high MpL are found to fragment excessively, at odds with observations. This is resolved by taking into account the magnetic field (treated simply as additional pressure support). The present theory suggests two complementary modes of star formation: although small (spherical or filamentary) structures will collapse directly into prestellar cores, according to the standard Hennebelle–Chabrier theory, the large (filamentary) ones, the dominant population according to observations, will follow the aforedescribed two-step process.

  8. Gamma Radiation from Fission Fragments Experimental Apparatus-Mass Spectrum Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-08-15

    The gamma-radiation from fission fragments was studied as a function of the fragment mass. The mass was determined from the fragment energies using solid state detectors. The mass resolution which can be achieved by this method is treated in detail. The average initial fragment mass and the initial mass resolution is calculated as a function of the measured (apparent) mass yield for three different thicknesses of the fissile material deposit. This treatment gives a clear indication of those factors most important for good mass resolution work. A detailed description of the experimental apparatus is given in the appendices.

  9. High mass-asymmetry distributions of fissioning nuclei

    International Nuclear Information System (INIS)

    Sandulescu, A.; Lusting, H.J.; Hahn, J.; Greiner, W.

    1978-07-01

    It is shown that new mass-asymmetry valleys are appearing in the fragmentation potential V(l,eta) as function of the length l and mass-asymmetry coordinate eta = (A 1 - A 2 )to a correct treatment of the shell effects such that for separated fragments the shell effects equal the sum of the shell effects of the individual fragments and correspond to the double magic fragments 48 Ca, 78 Ni, 132 Sn and 208 Pb or may be 56 Ni. Also is shown that the fission mass-distributions have additional peaks corresponding to the bottom of these new valleys. The calculations are illustrated for 252 No and 238 U. The preliminary results show for 238 U relatively high percent yields in agreement with present available experimental data. (author)

  10. A new statistical scission-point model fed with microscopic ingredients to predict fission fragments distributions

    International Nuclear Information System (INIS)

    Heinrich, S.

    2006-01-01

    Nucleus fission process is a very complex phenomenon and, even nowadays, no realistic models describing the overall process are available. The work presented here deals with a theoretical description of fission fragments distributions in mass, charge, energy and deformation. We have reconsidered and updated the B.D. Wilking Scission Point model. Our purpose was to test if this statistic model applied at the scission point and by introducing new results of modern microscopic calculations allows to describe quantitatively the fission fragments distributions. We calculate the surface energy available at the scission point as a function of the fragments deformations. This surface is obtained from a Hartree Fock Bogoliubov microscopic calculation which guarantee a realistic description of the potential dependence on the deformation for each fragment. The statistic balance is described by the level densities of the fragment. We have tried to avoid as much as possible the input of empirical parameters in the model. Our only parameter, the distance between each fragment at the scission point, is discussed by comparison with scission configuration obtained from full dynamical microscopic calculations. Also, the comparison between our results and experimental data is very satisfying and allow us to discuss the success and limitations of our approach. We finally proposed ideas to improve the model, in particular by applying dynamical corrections. (author)

  11. An Empirical Mass Function Distribution

    Science.gov (United States)

    Murray, S. G.; Robotham, A. S. G.; Power, C.

    2018-03-01

    The halo mass function, encoding the comoving number density of dark matter halos of a given mass, plays a key role in understanding the formation and evolution of galaxies. As such, it is a key goal of current and future deep optical surveys to constrain the mass function down to mass scales that typically host {L}\\star galaxies. Motivated by the proven accuracy of Press–Schechter-type mass functions, we introduce a related but purely empirical form consistent with standard formulae to better than 4% in the medium-mass regime, {10}10{--}{10}13 {h}-1 {M}ȯ . In particular, our form consists of four parameters, each of which has a simple interpretation, and can be directly related to parameters of the galaxy distribution, such as {L}\\star . Using this form within a hierarchical Bayesian likelihood model, we show how individual mass-measurement errors can be successfully included in a typical analysis, while accounting for Eddington bias. We apply our form to a question of survey design in the context of a semi-realistic data model, illustrating how it can be used to obtain optimal balance between survey depth and angular coverage for constraints on mass function parameters. Open-source Python and R codes to apply our new form are provided at http://mrpy.readthedocs.org and https://cran.r-project.org/web/packages/tggd/index.html respectively.

  12. Formation and distribution of fragments in the spontaneous fission of 240Pu

    Science.gov (United States)

    Sadhukhan, Jhilam; Zhang, Chunli; Nazarewicz, Witold; Schunck, Nicolas

    2017-12-01

    Background: Fission is a fundamental decay mode of heavy atomic nuclei. The prevalent theoretical approach is based on mean-field theory and its extensions where fission is modeled as a large amplitude motion of a nucleus in a multidimensional collective space. One of the important observables characterizing fission is the charge and mass distribution of fission fragments. Purpose: The goal of this Rapid Communication is to better understand the structure of fission fragment distributions by investigating the competition between the static structure of the collective manifold and the stochastic dynamics. In particular, we study the characteristics of the tails of yield distributions, which correspond to very asymmetric fission into a very heavy and a very light fragment. Methods: We use the stochastic Langevin framework to simulate the nuclear evolution after the system tunnels through the multidimensional potential barrier. For a representative sample of different initial configurations along the outer turning-point line, we define effective fission paths by computing a large number of Langevin trajectories. We extract the relative contribution of each such path to the fragment distribution. We then use nucleon localization functions along effective fission pathways to analyze the characteristics of prefragments at prescission configurations. Results: We find that non-Newtonian Langevin trajectories, strongly impacted by the random force, produce the tails of the fission fragment distribution of 240Pu. The prefragments deduced from nucleon localizations are formed early and change little as the nucleus evolves towards scission. On the other hand, the system contains many nucleons that are not localized in the prefragments even near the scission point. Such nucleons are distributed rapidly at scission to form the final fragments. Fission prefragments extracted from direct integration of the density and from the localization functions typically differ by more than

  13. Langevin description of fission fragment charge distribution from excited nuclei

    CERN Document Server

    Karpov, A V

    2002-01-01

    A stochastic approach to fission dynamics based on a set of three-dimensional Langevin equations was applied to calculate fission-fragment charge distribution of compound nucleus sup 2 sup 3 sup 6 U. The following collective coordinates have been chosen - elongation coordinate, neck-thickness coordinate, and charge-asymmetry coordinate. The friction coefficient of charge mode has been calculated in the framework of one-body and two-body dissipation mechanisms. Analysis of the results has shown that Langevin approach is appropriate for investigation of isobaric distribution. Moreover, the dependences of the variance of the charge distribution on excitation energy and on the two-body viscosity coefficient has been studied

  14. Study of momentum distributions for projectile fragments of 22Ne and 28Si nuclei in collisions with emulsion

    International Nuclear Information System (INIS)

    Abou-Steit, S.A.H.

    2000-01-01

    The charge and mass yield curves and the momentum distributions of the projectile fragments produced in the interactions of 4.1 A GeV/c 22 Ne and 4.5 A GeV/c 28 Si with emulsion have been studied. The overall charge distributions of the projectile fragments resulting from these interactions are presented. The dependence of the mass yield distributions of the projectile fragments on the impact parameter has been tested. The momentum distributions for the considered reactions have been investigated by two methods. First, the projected momentum distributions in the plane of the microscope have been achieved by fitting the projected angular distributions to gaussian ones. It has been found that the width of the distribution changes with the charge of the projectile fragment and it decreases with the increase of the projectile fragment charge. Secondly, the transverse momentum distributions have been compared with previous studies. The momentum distribution, in the forward cone, is a typically narrow gaussian one

  15. Complete isotopic distributions of fragments produced in transfer- and fusion-induced reactions

    International Nuclear Information System (INIS)

    Delaune, O.; Caamano, M.; Farget, F.; Tarasov, O. B.; Derkx, X.; Schmidt, K. H.; Audouin, L.; Amthor, A. M.; Bacri, C. O.; Barreau, G.; Bastin, B.; Bazin, D.; Benlliure, J.; Blank, B.; Caceres, L.; Casarejos, E.; Fernandez-Dominguez, B.; Gaudefroy, L.; Golabek, C.; Grevy, S.; Jurado, B.; Kamalou, O.; Lemasson, A.; Lukyanov, S. M.; Mittig, W.; Morrissey, D. J.; Navin, A.; Pereira, J.; Perrot, L.; Rejmund, M.; Roger, T.; Saint-Laurent, M. G.; Savajols, H.; Schmitt, C.; Sherrill, B. M.; Stodel, C.; Thomas, J. C.; Villari, A. C. C.

    2013-01-01

    Two fission experiments have been performed at GANIL using 238 U beams at different energies and light targets. Different fissioning systems were produced with centre of mass energies from 10 to 240 MeV and their decay by fission was investigated with GANIL spectrometers. Fission-fragment isotopic distributions have been obtained. The evolution with impinging energy of their properties, the neutron excess and the width of the neutron-number distributions, gives important insights into the dynamics of the fusion-fission mechanism. (authors)

  16. Percolation versus microcanonical fragmentation - comparison of fragment size distribution: Where is the liquid-gas transition in nuclei?

    International Nuclear Information System (INIS)

    Jaqaman, H.R.; Birzeit Univ.; Papp, G.; Eoetvoes Lorand Tudomanyegyetem, Budapest; Gross, D.H.E.; Freie Univ. Berlin

    1990-01-01

    The distributions of fragments produced by microcanonical multifragmentation of hot nuclei are compared with the cluster distributions predicted by a bond percolation model on a finite lattice. The conditional moments of these distributions are used together with the correlations between the largest three fragments in each event. Whereas percolation and statistical nuclear fragmentation agree in many details as in the usual plots of the averaged moments of the fragment distributions which yield the critical exponents, they turn out to be essentially different when less averaged quantities or correlations are considered. The differences between the predictions of the two models are mainly due to the particularities of the nuclear problem, especially the effect of the long-range Coulomb force which favours the break-up of the highly excited nucleus into two large fragments (pseudo-fission) and, to a somewhat lesser extent, enhances the possibility for the cracking of the nucleus into more than two large fragments. The fission events are, however, clearly separated from a second branch of critical correlations which shows up clearly in both nuclear fragmentation and percolation. We think that this critical correlation branch is due to the liquid-gas phase transition in finite nuclei. (orig.)

  17. Direct Determination of Molecular Weight Distribution of Calf-Thymus DNAs and Study of Their Fragmentation under Ultrasonic and Low-Energy IR Irradiations. A Charge Detection Mass Spectrometry Investigation.

    Science.gov (United States)

    Halim, Mohammad A; Bertorelle, Franck; Doussineau, Tristan; Antoine, Rodolphe

    2018-06-09

    Calf-thymus (CT-DNA) is widely used as binding agent. The commercial samples are known to be "highly polymerized DNA" samples. CT-DNA is known to be fragile in particular upon ultrasonic wave irradiation. Degradation products might have dramatic consequence on its bio-sensing activity, and an accurate determination of the molecular weight distribution and stability of commercial samples is highly demanded. We investigated the sensitivity of charge detection mass spectrometry (CDMS), a single-molecule MS method, both with single-pass and ion trap CDMS ("Benner" trap) modes to the determination of the composition and stability (under multiphoton IR irradiation) of calf-thymus DNAs. We also investigated the changes of molecular weight distributions in the course of sonication by irradiating ultrasonic wave to CT-DNA. We report for the first time, the direct molecular weight (MW) distribution of DNA sodium salt from calf-thymus revealing two populations at high (~10 MDa) and low (~3 MDa) molecular weights. We evidence a transition between the high-MW to the low-MW distribution, confirming that the low-MW distribution results from degradation of CT-DNA. Finally, we report also IRMPD experiments carried out on trapped single-stranded linear DNAs from calf-thymus allowing to extract their activation energy for unimolecular dissociation. We show that single-pass CDMS is a direct, efficient and accurate MS-based approach to determine the composition of calf-thymus DNAs. Furthermore, ion trap CDMS allows us to evaluate the stability (both under multiphoton IR irradiation and in the course of sonication by irradiating ultrasonic wave) of calf-thymus DNAs. This article is protected by copyright. All rights reserved.

  18. Exact Solutions of Fragmentation Equations with General Fragmentation Rates and Separable Particles Distribution Kernels

    Directory of Open Access Journals (Sweden)

    S. C. Oukouomi Noutchie

    2014-01-01

    Full Text Available We make use of Laplace transform techniques and the method of characteristics to solve fragmentation equations explicitly. Our result is a breakthrough in the analysis of pure fragmentation equations as this is the first instance where an exact solution is provided for the fragmentation evolution equation with general fragmentation rates. This paper is the key for resolving most of the open problems in fragmentation theory including “shattering” and the sudden appearance of infinitely many particles in some systems with initial finite particles number.

  19. Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    Science.gov (United States)

    van Agthoven, Maria A; Barrow, Mark P; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O'Connor, Peter B

    2015-12-01

    Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a sample. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules. Graphical Abstract ᅟ.

  20. Comprehensive and accurate tracking of carbon origin of LC-tandem mass spectrometry collisional fragments for 13C-MFA.

    Science.gov (United States)

    Kappelmann, Jannick; Klein, Bianca; Geilenkirchen, Petra; Noack, Stephan

    2017-03-01

    In recent years the benefit of measuring positionally resolved 13 C-labeling enrichment from tandem mass spectrometry (MS/MS) collisional fragments for improved precision of 13 C-Metabolic Flux Analysis ( 13 C-MFA) has become evident. However, the usage of positional labeling information for 13 C-MFA faces two challenges: (1) The mass spectrometric acquisition of a large number of potentially interfering mass transitions may hamper accuracy and sensitivity. (2) The positional identity of carbon atoms of product ions needs to be known. The present contribution addresses the latter challenge by deducing the maximal positional labeling information contained in LC-ESI-MS/MS spectra of product anions of central metabolism as well as product cations of amino acids. For this purpose, we draw on accurate mass spectrometry, selectively labeled standards, and published fragmentation pathways to structurally annotate all dominant mass peaks of a large collection of metabolites, some of which with a complete fragmentation pathway. Compiling all available information, we arrive at the most detailed map of carbon atom fate of LC-ESI-MS/MS collisional fragments yet, comprising 170 intense and structurally annotated product ions with unique carbon origin from 76 precursor ions of 72 metabolites. Our 13 C-data proof that heuristic fragmentation rules often fail to yield correct fragment structures and we expose common pitfalls in the structural annotation of product ions. We show that the positionally resolved 13 C-label information contained in the product ions that we structurally annotated allows to infer the entire isotopomer distribution of several central metabolism intermediates, which is experimentally demonstrated for malate using quadrupole-time-of-flight MS technology. Finally, the inclusion of the label information from a subset of these fragments improves flux precision in a Corynebacterium glutamicum model of the central carbon metabolism.

  1. Assessment of fragment projection hazard: probability distributions for the initial direction of fragments.

    Science.gov (United States)

    Tugnoli, Alessandro; Gubinelli, Gianfilippo; Landucci, Gabriele; Cozzani, Valerio

    2014-08-30

    The evaluation of the initial direction and velocity of the fragments generated in the fragmentation of a vessel due to internal pressure is an important information in the assessment of damage caused by fragments, in particular within the quantitative risk assessment (QRA) of chemical and process plants. In the present study an approach is proposed to the identification and validation of probability density functions (pdfs) for the initial direction of the fragments. A detailed review of a large number of past accidents provided the background information for the validation procedure. A specific method was developed for the validation of the proposed pdfs. Validated pdfs were obtained for both the vertical and horizontal angles of projection and for the initial velocity of the fragments. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. On the Mass Distribution of Stellar-Mass Black Holes

    Directory of Open Access Journals (Sweden)

    Malkov O. Yu.

    2014-12-01

    Full Text Available The observational stellar-mass black hole mass distribution exhibits a maximum at about 8 M⊙. It can be explained via the details of the massive star evolution, supernova explosions, or consequent black hole evolution. We propose another explanation, connected with an underestimated influence of the relation between the initial stellar mass and the compact remnant mass. We show that an unimodal observational mass distribution of black holes can be produced by a power-law initial mass function and a monotonic “remnant mass versus initial mass” relation.

  3. Using fragmentation trees and mass spectral trees for identifying unknown compounds in metabolomics.

    Science.gov (United States)

    Vaniya, Arpana; Fiehn, Oliver

    2015-06-01

    Identification of unknown metabolites is the bottleneck in advancing metabolomics, leaving interpretation of metabolomics results ambiguous. The chemical diversity of metabolism is vast, making structure identification arduous and time consuming. Currently, comprehensive analysis of mass spectra in metabolomics is limited to library matching, but tandem mass spectral libraries are small compared to the large number of compounds found in the biosphere, including xenobiotics. Resolving this bottleneck requires richer data acquisition and better computational tools. Multi-stage mass spectrometry (MSn) trees show promise to aid in this regard. Fragmentation trees explore the fragmentation process, generate fragmentation rules and aid in sub-structure identification, while mass spectral trees delineate the dependencies in multi-stage MS of collision-induced dissociations. This review covers advancements over the past 10 years as a tool for metabolite identification, including algorithms, software and databases used to build and to implement fragmentation trees and mass spectral annotations.

  4. Rock fragment distributions and regolith evolution in the Ouachita Mountains, Arkansas, USA

    Science.gov (United States)

    Jonathan D. Phillips; Ken Luckow; Daniel A. Marion; Kristin R. Adams

    2005-01-01

    Rock fragments in the regolith are a persistent property that reflects the combined influences of geologic controls, erosion, deposition, bioturbation, and weathering. The distribution of rock fragments in regoliths of the Ouachita Mountains, Arkansas, shows that sandstone fragments are common in all layers, even if sandstone is absent in parent material. Shale and...

  5. A fragmentation study of kaempferol using electrospray quadrupole time-of-flight mass spectrometry at high mass resolution

    Science.gov (United States)

    March, Raymond E.; Miao, Xiu-Sheng

    2004-02-01

    A mass spectrometric method based on the combined use of electrospray ionization, collision-induced dissociation and tandem mass spectrometry at high mass resolution has been applied to an investigation of the structural characterization of protonated and deprotonated kaempferol (3,5,7,4'-tetrahydroxyflavone). Low-energy product ion mass spectra of [M+H]+ ions showed simple fragmentations of the C ring that permitted characterization of the substituents in the A and B rings. In addition, four rearrangement reactions accompanied by losses of C2H2O, CHO[radical sign], CO, and H2O were observed. Low-energy product ion mass spectra of [M-H]- ions showed only four rearrangement reactions accompanied by losses of OH[radical sign], CO, CH2O, and C2H2O. The use of elevated cone voltages permitted observation of product ion mass spectra of selected primary and secondary fragment ions so that each fragment ion reported was observed as a direct product of its immediate precursor ion. Product ion mass spectra examined at high mass resolution allowed unambiguous determination of the elemental composition of fragment ions and resolution of two pairs of isobars. Fragmentation mechanisms and ion structures have been proposed.

  6. THE SMALL-SCALE PHYSICAL STRUCTURE AND FRAGMENTATION DIFFERENCE OF TWO EMBEDDED INTERMEDIATE-MASS PROTOSTARS IN ORION

    International Nuclear Information System (INIS)

    Van Kempen, T. A.; Longmore, S. N.; Johnstone, D.; Pillai, T.; Fuente, A.

    2012-01-01

    Intermediate-mass (IM) protostars, the bridge between the very common solar-like protostars and the more massive, but rarer, O and B stars, can only be studied at high physical spatial resolutions in a handful of clouds. In this paper, we present and analyze the continuum results from an observing campaign at the Submillimeter Array (SMA) targeting two well-studied IM protostars in Orion, NGC 2071 and L1641 S3 MMS 1. The extended SMA (eSMA) probes structure at angular resolutions up to 0.''2, revealing protostellar disks on scales of ∼200 AU. Continuum flux measurements on these scales indicate that a significant amount of mass, a few tens of M ☉ , is present. Envelope, stellar, and disk masses are derived using compact, extended, and eSMA configurations and compared against spectral energy distribution fitting models. We hypothesize that fragmentation into three components occurred within NGC 2071 at an early time, when the envelopes were less than 10% of their current masses, e.g., ☉ . No fragmentation occurred for L1641 S3 MMS 1. For NGC 2071, evidence is given that the bulk of the envelope material currently around each source was accreted after the initial fragmentation. In addition, about 30% of the total core mass is not yet associated to one of the three sources. A global accretion model is favored and a potential accretion history of NGC 2071 is presented. It is shown that the relatively low level of fragmentation in NGC 2071 was stifled compared to the expected fragmentation from a Jeans argument. Similarly, the lack of fragmentation in L1641 S3 MMS 1 is likely due to similar arguments.

  7. THE SMALL-SCALE PHYSICAL STRUCTURE AND FRAGMENTATION DIFFERENCE OF TWO EMBEDDED INTERMEDIATE-MASS PROTOSTARS IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Van Kempen, T. A. [Joint ALMA Offices, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Longmore, S. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Johnstone, D. [National Research Council Canada, Herzberg Institute for Astronomy, 5071 West Saanich Road, Victoria, BC (Canada); Pillai, T. [Caltech, MC 249-17, 1200 East California Blvd, Pasadena, CA 91125 (United States); Fuente, A., E-mail: tkempen@alma.cl [Observatorio Astronomico Nacional (OAN), Apdo. 112, E-28803 Alcala de Henares, Madrid (Spain)

    2012-06-01

    Intermediate-mass (IM) protostars, the bridge between the very common solar-like protostars and the more massive, but rarer, O and B stars, can only be studied at high physical spatial resolutions in a handful of clouds. In this paper, we present and analyze the continuum results from an observing campaign at the Submillimeter Array (SMA) targeting two well-studied IM protostars in Orion, NGC 2071 and L1641 S3 MMS 1. The extended SMA (eSMA) probes structure at angular resolutions up to 0.''2, revealing protostellar disks on scales of {approx}200 AU. Continuum flux measurements on these scales indicate that a significant amount of mass, a few tens of M{sub Sun }, is present. Envelope, stellar, and disk masses are derived using compact, extended, and eSMA configurations and compared against spectral energy distribution fitting models. We hypothesize that fragmentation into three components occurred within NGC 2071 at an early time, when the envelopes were less than 10% of their current masses, e.g., <0.5 M{sub Sun }. No fragmentation occurred for L1641 S3 MMS 1. For NGC 2071, evidence is given that the bulk of the envelope material currently around each source was accreted after the initial fragmentation. In addition, about 30% of the total core mass is not yet associated to one of the three sources. A global accretion model is favored and a potential accretion history of NGC 2071 is presented. It is shown that the relatively low level of fragmentation in NGC 2071 was stifled compared to the expected fragmentation from a Jeans argument. Similarly, the lack of fragmentation in L1641 S3 MMS 1 is likely due to similar arguments.

  8. THE MASS DISTRIBUTION OF STELLAR-MASS BLACK HOLES

    International Nuclear Information System (INIS)

    Farr, Will M.; Sravan, Niharika; Kalogera, Vicky; Cantrell, Andrew; Kreidberg, Laura; Bailyn, Charles D.; Mandel, Ilya

    2011-01-01

    We perform a Bayesian analysis of the mass distribution of stellar-mass black holes using the observed masses of 15 low-mass X-ray binary systems undergoing Roche lobe overflow and 5 high-mass, wind-fed X-ray binary systems. Using Markov Chain Monte Carlo calculations, we model the mass distribution both parametrically—as a power law, exponential, Gaussian, combination of two Gaussians, or log-normal distribution—and non-parametrically—as histograms with varying numbers of bins. We provide confidence bounds on the shape of the mass distribution in the context of each model and compare the models with each other by calculating their relative Bayesian evidence as supported by the measurements, taking into account the number of degrees of freedom of each model. The mass distribution of the low-mass systems is best fit by a power law, while the distribution of the combined sample is best fit by the exponential model. This difference indicates that the low-mass subsample is not consistent with being drawn from the distribution of the combined population. We examine the existence of a 'gap' between the most massive neutron stars and the least massive black holes by considering the value, M 1% , of the 1% quantile from each black hole mass distribution as the lower bound of black hole masses. Our analysis generates posterior distributions for M 1% ; the best model (the power law) fitted to the low-mass systems has a distribution of lower bounds with M 1% >4.3 M sun with 90% confidence, while the best model (the exponential) fitted to all 20 systems has M 1% >4.5 M sun with 90% confidence. We conclude that our sample of black hole masses provides strong evidence of a gap between the maximum neutron star mass and the lower bound on black hole masses. Our results on the low-mass sample are in qualitative agreement with those of Ozel et al., although our broad model selection analysis more reliably reveals the best-fit quantitative description of the underlying mass

  9. ON THE MASS DISTRIBUTION AND BIRTH MASSES OF NEUTRON STARS

    International Nuclear Information System (INIS)

    Özel, Feryal; Psaltis, Dimitrios; Santos Villarreal, Antonio; Narayan, Ramesh

    2012-01-01

    We investigate the distribution of neutron star masses in different populations of binaries, employing Bayesian statistical techniques. In particular, we explore the differences in neutron star masses between sources that have experienced distinct evolutionary paths and accretion episodes. We find that the distribution of neutron star masses in non-recycled eclipsing high-mass binaries as well as of slow pulsars, which are all believed to be near their birth masses, has a mean of 1.28 M ☉ and a dispersion of 0.24 M ☉ . These values are consistent with expectations for neutron star formation in core-collapse supernovae. On the other hand, double neutron stars, which are also believed to be near their birth masses, have a much narrower mass distribution, peaking at 1.33 M ☉ , but with a dispersion of only 0.05 M ☉ . Such a small dispersion cannot easily be understood and perhaps points to a particular and rare formation channel. The mass distribution of neutron stars that have been recycled has a mean of 1.48 M ☉ and a dispersion of 0.2 M ☉ , consistent with the expectation that they have experienced extended mass accretion episodes. The fact that only a very small fraction of recycled neutron stars in the inferred distribution have masses that exceed ∼2 M ☉ suggests that only a few of these neutron stars cross the mass threshold to form low-mass black holes.

  10. Theoretical study of intermediate-mass fragments in proton-nucleus reactions at 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sabra, Mohammad S. [NASA Marshall Space Flight Center, USRA Space Science Department, Huntsville, AL (United States)

    2017-03-15

    We have analyzed energy spectra, angular distributions, and mass and charge distributions of intermediate-mass fragments (IMFs) from the interaction of {sup 27}Al, {sup 59}Co, and {sup 197}Au with 200 MeV protons. Calculations within the modified statistical model with final-state interaction were performed using SAPTON code. Within the experimental uncertainty and constraint, SAPTON shows good agreement with the data, and suggests that the IMFs are produced after the intra-nuclear cascade stage, and during the surface coalescence, as well as the evaporation/fission stages. (orig.)

  11. Advancement of magma fragmentation by inhomogeneous bubble distribution.

    Science.gov (United States)

    Kameda, M; Ichihara, M; Maruyama, S; Kurokawa, N; Aoki, Y; Okumura, S; Uesugi, K

    2017-12-01

    Decompression times reported in previous studies suggest that thoroughly brittle fragmentation is unlikely in actual explosive volcanic eruptions. What occurs in practice is brittle-like fragmentation, which is defined as the solid-like fracture of a material whose bulk rheological properties are close to those of a fluid. Through laboratory experiments and numerical simulation, the link between the inhomogeneous structure of bubbles and the development of cracks that may lead to brittle-like fragmentation was clearly demonstrated here. A rapid decompression test was conducted to simulate the fragmentation of a specimen whose pore morphology was revealed by X-ray microtomography. The dynamic response during decompression was observed by high-speed photography. Large variation was observed in the responses of the specimens even among specimens with equal bulk rheological properties. The stress fields of the specimens under decompression computed by finite element analysis shows that the presence of satellite bubbles beneath a large bubble induced the stress concentration. On the basis of the obtained results, a new mechanism for brittle-like fragmentation is proposed. In the proposed scenario, the second nucleation of bubbles near the fragmentation surface is an essential process for the advancement of fragmentation in an upward magma flow in a volcanic conduit.

  12. Critical Evaluation of Native Electrospray Ionization Mass Spectrometry for Fragment-Based Screening.

    Science.gov (United States)

    Göth, Melanie; Badock, Volker; Weiske, Jörg; Pagel, Kevin; Kuropka, Benno

    2017-08-08

    Fragment-based screening presents a promising alternative to high-throughput screening and has gained great attention in recent years. So far, only a few studies have discussed mass spectrometry as a screening technology for fragments. Herein, we report the application of native electrospray ionization mass spectrometry (MS) for screening defined sets of fragments against four different target proteins. Fragments were selected from a primary screening conducted with a thermal shift assay (TSA) and represented different binding categories. Our data indicated that, beside specific complex formation, many fragments show extensive multiple binding and also charge-state shifts. Both of these factors complicate automated data analysis and decrease the attractiveness of native MS as a primary screening tool for fragments. A comparison of the hits identified by native MS and TSA showed good agreement for two of the proteins. Furthermore, we discuss general challenges, including the determination of an optimal fragment concentration and the question of how to rank fragment hits according to their affinity. In conclusion, we consider native MS to be a highly valuable tool for the validation and deeper investigation of promising fragment hits rather than a method for primary screening. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Characteristic relation for the mass and energy distribution of the nuclear fission products

    International Nuclear Information System (INIS)

    Alexandru, G.

    1977-01-01

    The dispersion relation for nuclear fission is written in the two part fragmentation approach which allows to obtain the characteristic relation for the mass and energy distribution of the nuclear fission products. One explains the resonance approximation in the mass distribution of the fission products taking into account the high order resonances too. (author)

  14. Effects of Mixtures on Liquid and Solid Fragment Size Distributions

    Science.gov (United States)

    2016-05-01

    bins, too few size bins, fixed bin widths, or inadequately- varying bin widths. Overpopulated bins – which typically occur for smaller fragments...2010 C. V. B. Cunningham, The Kuz-Ram Fragmentation Model – 20 Years On, In R. Holmberg et. al., Editors, Proceedings of the 3 rd World ...1992 P. K. Sahoo and T. Riedel, Mean Value Theorems and Functional Equations, World Scientific, 1998 K. A. Sallam, C. Aalburg, G.M. Faeth

  15. De novo analysis of electron impact mass spectra using fragmentation trees

    International Nuclear Information System (INIS)

    Hufsky, Franziska; Rempt, Martin; Rasche, Florian; Pohnert, Georg; Böcker, Sebastian

    2012-01-01

    Highlights: ► We present a method for de novo analysis of accurate mass EI mass spectra of small molecules. ► This method identifies the molecular ion and thus the molecular formula where the molecular ion is present in the spectrum. ► Fragmentation trees are constructed by automated signal extraction and evaluation. ► These trees explain relevant fragmentation reactions. ► This method will be very helpful in the automated analysis of unknown metabolites. - Abstract: The automated fragmentation analysis of high resolution EI mass spectra based on a fragmentation tree algorithm is introduced. Fragmentation trees are constructed from EI spectra by automated signal extraction and evaluation. These trees explain relevant fragmentation reactions and assign molecular formulas to fragments. The method enables the identification of the molecular ion and the molecular formula of a metabolite if the molecular ion is present in the spectrum. These identifications are independent of existing library knowledge and, thus, support assignment and structural elucidation of unknown compounds. The method works even if the molecular ion is of very low abundance or hidden under contaminants with higher masses. We apply the algorithm to a selection of 50 derivatized and underivatized metabolites and demonstrate that in 78% of cases the molecular ion can be correctly assigned. The automatically constructed fragmentation trees correspond very well to published mechanisms and allow the assignment of specific relevant fragments and fragmentation pathways even in the most complex EI-spectra in our dataset. This method will be very helpful in the automated analysis of metabolites that are not included in common libraries and it thus has the potential to support the explorative character of metabolomics studies.

  16. Fission fragment angular distributions and fission cross section validation

    International Nuclear Information System (INIS)

    Leong, Lou Sai

    2013-01-01

    The present knowledge of angular distributions of neutron-induced fission is limited to a maximal energy of 15 MeV, with large discrepancies around 14 MeV. Only 238 U and 232 Th have been investigated up to 100 MeV in a single experiment. The n-TOF Collaboration performed the fission cross section measurement of several actinides ( 232 Th, 235 U, 238 U, 234 U, 237 Np) at the n-TOF facility using an experimental set-up made of Parallel Plate Avalanche Counters (PPAC), extending the energy domain of the incident neutron above hundreds of MeV. The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. I will show the methods we used to reconstruct the full angular resolution by the tracking of fission fragments. Below 10 MeV our results are consistent with existing data. For example in the case of 232 Th, below 10 MeV the results show clearly the variation occurring at the first (1 MeV) and second (7 MeV) chance fission, corresponding to transition states of given J and K (total spin and its projection on the fission axis), and a much more accurate energy dependence at the 3. chance threshold (14 MeV) has been obtained. In the spallation domain, above 30 MeV we confirm the high anisotropy revealed in 232 Th by the single existing data set. I'll discuss the implications of this finding, related to the low anisotropy exhibited in proton-induced fission. I also explore the critical experiments which is valuable checks of nuclear data. The 237 Np neutron-induced fission cross section has recently been measured in a large energy range (from eV to GeV) at the n-TOF facility at CERN. When compared to previous measurements, the n-TOF fission cross section appears to be higher by 5-7 % beyond the fission threshold. To check the relevance of n-TOF data, we simulate a criticality experiment performed at Los Alamos with a 6 kg sphere of 237 Np. This

  17. Mass distributions in nucleon-induced fission at intermediate energies

    CERN Document Server

    Duijvestijn, M C; Hambsch, F J

    2001-01-01

    Temperature-dependent fission barriers and fission-fragment mass distributions are calculated in the framework of the multimodal random neck-rupture model (MM-RNRM). It is shown how the distinction between the different fission modes disappears at higher excitation energies, due to the melting of shell effects. The fission-fragment mass yield calculations are coupled to the nuclear reaction code ALICE-91, which takes into account the competition between the other reaction channels and fission. With the combination of the temperature-dependent MM-RNRM and ALICE-91 nucleon-induced fission is investigated at energies between 10 and 200 MeV for nuclei varying from Au to Am. (72 refs).

  18. Native State Mass Spectrometry, Surface Plasmon Resonance, and X-ray Crystallography Correlate Strongly as a Fragment Screening Combination.

    Science.gov (United States)

    Woods, Lucy A; Dolezal, Olan; Ren, Bin; Ryan, John H; Peat, Thomas S; Poulsen, Sally-Ann

    2016-03-10

    Fragment-based drug discovery (FBDD) is contingent on the development of analytical methods to identify weak protein-fragment noncovalent interactions. Herein we have combined an underutilized fragment screening method, native state mass spectrometry, together with two proven and popular fragment screening methods, surface plasmon resonance and X-ray crystallography, in a fragment screening campaign against human carbonic anhydrase II (CA II). In an initial fragment screen against a 720-member fragment library (the "CSIRO Fragment Library") seven CA II binding fragments, including a selection of nonclassical CA II binding chemotypes, were identified. A further 70 compounds that comprised the initial hit chemotypes were subsequently sourced from the full CSIRO compound collection and screened. The fragment results were extremely well correlated across the three methods. Our findings demonstrate that there is a tremendous opportunity to apply native state mass spectrometry as a complementary fragment screening method to accelerate drug discovery.

  19. Hypoxia, Radiosensitizers and high-LET radiation - Nimorazole fragmentation using mass spectrometry

    DEFF Research Database (Denmark)

    Feketeova, Linda; Bassler, Niels

    (s): Fragmentation experiments have been performed using a Finnigan- LTQ-FT mass spectrometer equipped with an electrospray ionisation source. Collision-induced dissociation (CID) and electron-induced dissociation (EID) have been carried out by mass selecting the desired ions and subjecting them to activation energy...... using mass spectrometry. Understanding the fragmentation of radiosensitizers is crucial in evaluating the radiosensitization potential and developing new and more effective drugs, which may improve TCP in hypoxic tumours when using ion beams such as carbon-12 along with LET-painting techniques. Method...

  20. Proposal for a common nomenclature for fragment ions in mass spectra of lipids

    DEFF Research Database (Denmark)

    Pauling, Josch K; Hermansson, Martin; Hartler, Jürgen

    2017-01-01

    Advances in mass spectrometry-based lipidomics have in recent years prompted efforts to standardize the annotation of the vast number of lipid molecules that can be detected in biological systems. These efforts have focused on cataloguing, naming and drawing chemical structures of intact lipid...... molecules, but have provided no guidelines for annotation of lipid fragment ions detected using tandem and multi-stage mass spectrometry, albeit these fragment ions are mandatory for structural elucidation and high confidence lipid identification, especially in high throughput lipidomics workflows. Here we...... propose a nomenclature for the annotation of lipid fragment ions, describe its implementation and present a freely available web application, termed ALEX123 lipid calculator, that can be used to query a comprehensive database featuring curated lipid fragmentation information for more than 430...

  1. Fragmentation

    Science.gov (United States)

    K.H. Riitters

    2009-01-01

    Effective resource management takes into account the administrative and biophysical settings within which natural resources occur. A setting may be described in many ways; for example, by forest land ownership, by reserved and roadless designation, or by the distribution of human populations in relation to forest (chapter 3). The physical arrangement of forest in a...

  2. Soil erosion and effluent particle size distribution under different initial conditions and rock fragment coverage

    Science.gov (United States)

    Jomaa, S.; Barry, D. A.; Brovelli, A.; Heng, B. C. P.; Sander, G. C.; Parlange, J.-Y.

    2012-04-01

    It is well known that the presence of rock fragments on the soil surface and the soil's initial characteristics (moisture content, surface roughness, bulk density, etc.) are key factors influencing soil erosion dynamics and sediment delivery. In addition, the interaction of these factors increases the complexity of soil erosion patterns and makes predictions more difficult. The aim of this study was (i) to investigate the effect of soil initial conditions and rock fragment coverage on soil erosion yields and effluent particle size distribution and (ii) to evaluate to what extent the rock fragment coverage controls this relationship. Three laboratory flume experiments with constant precipitation rate of 74 mm/h on a loamy soil parcel with a 2% slope were performed. Experiments with duration of 2 h were conducted using the 6-m × 2-m EPFL erosion flume. During each experiment two conditions were considered, a bare soil and a rock fragment-protected (with 40% coverage) soil. The initial soil surface state was varied between the three experiments, from a freshly re-ploughed and almost dry condition to a compacted soil with a well-developed shield layer and high moisture content. Experiments were designed so that rain splash was the primary driver of soil erosion. Results showed that the amount of eroded mass was highly controlled by the initial soil conditions and whether the steady-state equilibrium was un-, partially- or fully- developed during the previous event. Additionally, results revealed that sediment yields and particle size composition in the initial part of an erosion event are more sensitive to the erosion history than the long-time behaviour. This latter appears to be mainly controlled by rainfall intensity. If steady-state was achieved for a previous event, then the next event consistently produced concentrations for each size class that peaked rapidly, and then declined gradually to steady-state equilibrium. If steady state was not obtained, then

  3. On the Mass Distribution of Animal Species

    Science.gov (United States)

    Redner, Sidney; Clauset, Aaron; Schwab, David

    2009-03-01

    We develop a simple diffusion-reaction model to account for the broad and asymmetric distribution of adult body masses for species within related taxonomic groups. The model assumes three basic evolutionary features that control body mass: (i) a fixed lower limit that is set by metabolic constraints, (ii) a species extinction risk that is a weakly increasing function of body mass, and (iii) cladogenetic diffusion, in which daughter species have a slight tendency toward larger mass. The steady-state solution for the distribution of species masses in this model can be expressed in terms of the Airy function. This solution gives mass distributions that are in good agreement with data on 4002 terrestrial mammal species from the late Quaternary and 8617 extant bird species.

  4. Coherent control of indirect photofragmentation in the weak-field limit: Control of transient fragment distributions

    DEFF Research Database (Denmark)

    Shu, Chuan-Cun; Henriksen, Niels Engholm

    2011-01-01

    I molecule, where it is shown that the probability of observing atomic fragments as well as the distribution of their relative momenta can be changed by a phase modulated pulse with a fixed bandwidth. This type of control is restricted to finite times during the indirect fragmentation. (C) 2011 American...

  5. Multiplicity distributions in the binary fragmenting with inhibition at the transition line

    Energy Technology Data Exchange (ETDEWEB)

    Botet, R. [Paris-11 Univ., 91 - Orsay (France); Ploszajczak, M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)

    1996-03-01

    Properties of the fragment multiplicity distribution obtained in the sequential binary fragmentation process at the transition line are investigated. It is shown that the multifragment cumulant correlation functions have the hierarchical, linked-pair structure. Several distinct classes of multiplicity domains are clearly identified, and the asymptotic appearance of the Koba - Nielsen - Olesen scaling is discussed. (author). 36 refs.

  6. Multiplicity distributions in the binary fragmenting with inhibition at the transition line

    International Nuclear Information System (INIS)

    Botet, R.; Ploszajczak, M.

    1996-03-01

    Properties of the fragment multiplicity distribution obtained in the sequential binary fragmentation process at the transition line are investigated. It is shown that the multifragment cumulant correlation functions have the hierarchical, linked-pair structure. Several distinct classes of multiplicity domains are clearly identified, and the asymptotic appearance of the Koba - Nielsen - Olesen scaling is discussed. (author)

  7. Double-arm time-of-flight mass-spectrometer of nuclear fragments

    International Nuclear Information System (INIS)

    Ajvazian, G.M.; Astabatyan, R.A.

    1995-01-01

    A double-arm time-of-flight spectrometer of nuclear fragments for the investigation of heavy nuclei photofission in the intermediate energy range is described. The calibration results and working characteristics of the spectrometer, obtained using 252 Cf as a source of spontaneous fission, are presented. A mass resolution of σ m ∼2-3 a.m.u. was obtained within the registered fragments mass range of 80-160 a.m.u. The spectrometer was tested in the experiment on the investigation of 238 U nuclei fission by Bremsstahlung photons with Eγ max=1.75 GeV

  8. Estimating the Grain Size Distribution of Mars based on Fragmentation Theory and Observations

    Science.gov (United States)

    Charalambous, C.; Pike, W. T.; Golombek, M.

    2017-12-01

    We present here a fundamental extension to the fragmentation theory [1] which yields estimates of the distribution of particle sizes of a planetary surface. The model is valid within the size regimes of surfaces whose genesis is best reflected by the evolution of fragmentation phenomena governed by either the process of meteoritic impacts, or by a mixture with aeolian transportation at the smaller sizes. The key parameter of the model, the regolith maturity index, can be estimated as an average of that observed at a local site using cratering size-frequency measurements, orbital and surface image-detected rock counts and observations of sub-mm particles at landing sites. Through validation of ground truth from previous landed missions, the basis of this approach has been used at the InSight landing ellipse on Mars to extrapolate rock size distributions in HiRISE images down to 5 cm rock size, both to determine the landing safety risk and the subsequent probability of obstruction by a rock of the deployed heat flow mole down to 3-5 m depth [2]. Here we focus on a continuous extrapolation down to 600 µm coarse sand particles, the upper size limit that may be present through aeolian processes [3]. The parameters of the model are first derived for the fragmentation process that has produced the observable rocks via meteorite impacts over time, and therefore extrapolation into a size regime that is affected by aeolian processes has limited justification without further refinement. Incorporating thermal inertia estimates, size distributions observed by the Spirit and Opportunity Microscopic Imager [4] and Atomic Force and Optical Microscopy from the Phoenix Lander [5], the model's parameters in combination with synthesis methods are quantitatively refined further to allow transition within the aeolian transportation size regime. In addition, due to the nature of the model emerging in fractional mass abundance, the percentage of material by volume or mass that resides

  9. Manifestation of the halo structure in momentum distributions from {sup 6}He fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Aumann, T. [Mainz Univ. (Germany). Inst. fuer Kernchemie; Chulkov, L.V.; Pribora, V.N. [Rossijskij Nauchnyj Tsentr ``Kurchatovskij Inst.``, Moscow (Russian Federation); Smedberg, M.H. [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1998-03-01

    Experimental data on momentum distribution in the fragmentation of a 240 MeV/u {sup 6}He beam on a carbon target are compared with several models of the {sup 6}He nucleus based on different physical assumptions. It is shown that a lack of a strict theoretical description of the fragmentation mechanism and, in particular, of the final state interaction prevents from any contra or versa arguments for these models. The requirement of a fragment ({sup 5}He) survival or spatial localization of a fragment in the {sup 6}He wave function is an essential point in the reaction mechanism. The analysis of the {sup 5}He momentum (sum of the neutron and the {alpha}-particle momenta) distribution is free from the effect of final state interaction and thus more promising. It is shown that due to the requirement of fragment survival this distribution is determined mainly by the asymptotic of the {sup 6}He wave function. Large sensitivity to the outer part of the halo structure gives a unique possibility to estimate the admixture of s-waves in the ground states of {sup 11}Li and {sup 14}Be directly from the momentum distribution of {sup 10}Li (in fragmentation of {sup 11}Li) and from the momentum distribution of {sup 13}Be (in fragmentation of {sup 14}Be). The shell structure of these nuclei is of great interest in understanding the neutron-halo properties. (orig.)

  10. A Ligand-observed Mass Spectrometry Approach Integrated into the Fragment Based Lead Discovery Pipeline

    Science.gov (United States)

    Chen, Xin; Qin, Shanshan; Chen, Shuai; Li, Jinlong; Li, Lixin; Wang, Zhongling; Wang, Quan; Lin, Jianping; Yang, Cheng; Shui, Wenqing

    2015-01-01

    In fragment-based lead discovery (FBLD), a cascade combining multiple orthogonal technologies is required for reliable detection and characterization of fragment binding to the target. Given the limitations of the mainstream screening techniques, we presented a ligand-observed mass spectrometry approach to expand the toolkits and increase the flexibility of building a FBLD pipeline especially for tough targets. In this study, this approach was integrated into a FBLD program targeting the HCV RNA polymerase NS5B. Our ligand-observed mass spectrometry analysis resulted in the discovery of 10 hits from a 384-member fragment library through two independent screens of complex cocktails and a follow-up validation assay. Moreover, this MS-based approach enabled quantitative measurement of weak binding affinities of fragments which was in general consistent with SPR analysis. Five out of the ten hits were then successfully translated to X-ray structures of fragment-bound complexes to lay a foundation for structure-based inhibitor design. With distinctive strengths in terms of high capacity and speed, minimal method development, easy sample preparation, low material consumption and quantitative capability, this MS-based assay is anticipated to be a valuable addition to the repertoire of current fragment screening techniques. PMID:25666181

  11. Electron impact ionization of size selected hydrogen clusters (H2)N: ion fragment and neutral size distributions.

    Science.gov (United States)

    Kornilov, Oleg; Toennies, J Peter

    2008-05-21

    Clusters consisting of normal H2 molecules, produced in a free jet expansion, are size selected by diffraction from a transmission nanograting prior to electron impact ionization. For each neutral cluster (H2)(N) (N=2-40), the relative intensities of the ion fragments Hn+ are measured with a mass spectrometer. H3+ is found to be the most abundant fragment up to N=17. With a further increase in N, the abundances of H3+, H5+, H7+, and H9+ first increase and, after passing through a maximum, approach each other. At N=40, they are about the same and more than a factor of 2 and 3 larger than for H11+ and H13+, respectively. For a given neutral cluster size, the intensities of the ion fragments follow a Poisson distribution. The fragmentation probabilities are used to determine the neutral cluster size distribution produced in the expansion at a source temperature of 30.1 K and a source pressure of 1.50 bar. The distribution shows no clear evidence of a magic number N=13 as predicted by theory and found in experiments with pure para-H2 clusters. The ion fragment distributions are also used to extract information on the internal energy distribution of the H3+ ions produced in the reaction H2+ + H2-->H3+ +H, which is initiated upon ionization of the cluster. The internal energy is assumed to be rapidly equilibrated and to determine the number of molecules subsequently evaporated. The internal energy distribution found in this way is in good agreement with data obtained in an earlier independent merged beam scattering experiment.

  12. Novel scaling of the multiplicity distributions in the sequential fragmentation process and in the percolation

    International Nuclear Information System (INIS)

    Botet, R.

    1996-01-01

    A novel scaling of the multiplicity distributions is found in the shattering phase of the sequential fragmentation process with inhibition. The same scaling law is shown to hold in the percolation process. (author)

  13. Reexamination of fission fragment angular distributions and the fission process: Formalism

    International Nuclear Information System (INIS)

    Bond, P.D.

    1985-01-01

    The theory of fission fragment angular distributions is examined and the universally used expression is found to be valid only under restrictive assumptions. A more general angular distribution formula is derived and applied to recent data of high spin systems. At the same time it is shown that the strong anisotropies observed from such systems can be understood without changing the essential basis of standard fission theory. The effects of reaction mechanisms other than complete fusion on fission fragment angular distributions are discussed and possible angular distribution signatures of noncompound nucleus formation are mentioned

  14. Multiplicity distributions of shower particles and target fragments in ...

    Indian Academy of Sciences (India)

    2Institute of Theoretical Physics, Shanxi University, Taiyuan, Shanxi 030006, China. *Corresponding ... describes the probability distributions of different quantities [17–19]. ... In the Monte Carlo method, let Rij denote random numbers in [0,1].

  15. Universal elements of fragmentation

    International Nuclear Information System (INIS)

    Yanovsky, V. V.; Tur, A. V.; Kuklina, O. V.

    2010-01-01

    A fragmentation theory is proposed that explains the universal asymptotic behavior of the fragment-size distribution in the large-size range, based on simple physical principles. The basic principles of the theory are the total mass conservation in a fragmentation process and a balance condition for the energy expended in increasing the surface of fragments during their breakup. A flux-based approach is used that makes it possible to supplement the basic principles and develop a minimal theory of fragmentation. Such a supplementary principle is that of decreasing fragment-volume flux with increasing energy expended in fragmentation. It is shown that the behavior of the decreasing flux is directly related to the form of a power-law fragment-size distribution. The minimal theory is used to find universal asymptotic fragment-size distributions and to develop a natural physical classification of fragmentation models. A more general, nonlinear theory of strong fragmentation is also developed. It is demonstrated that solutions to a nonlinear kinetic equation consistent with both basic principles approach a universal asymptotic size distribution. Agreement between the predicted asymptotic fragment-size distributions and experimental observations is discussed.

  16. Distribution of rock fragments and their effects on hillslope soil erosion in purple soil, China

    Science.gov (United States)

    Wang, Xiaoyan

    2017-04-01

    Purple soil is widely distributed in Sichuan Basin and Three Gorges Reservoir Area. Purple soil region is abundant in soil fertility and hydrothermal resources, playing an important role in the agricultural development of China. Soil erosion has long been recognized as a major environmental problem in the purple soil region where the population is large and slope farming is commonly practiced, and rainstorm is numerous. The existence of rock fragments is one of the most important characteristics of purple soil. Rock fragments at the soil surface or in the soil layer affect soil erosion processes by water in various direct and indirect ways, thus the erosion processes of soil containing rock fragments have unique features. Against the severe soil degradation by erosion of purple soil slope, carrying out the research about the characteristics of purple soil containing rock fragments and understanding the influence of rock fragments on soil erosion processes have important significance, which would promote the rational utilization of purple soil slope land resources and accurate prediction of purple soil loss. Therefore, the aims of this study were to investigate the distribution of rock fragments in purple soil slope and the impact of rock fragment content on soil physical properties and soil erosion. First, field sampling methods were used to survey the spatial variability of rock fragments in soil profiles and along slope and the physical properties of soils containing rock fragments. Secondly, indoor simulated rainfall experiments were used to exam the effect of rock fragments in the soil layer on soil erosion processes and the relationships between rainfall infiltration, change of surface flow velocity, surface runoff volume and sediment on one hand, and rock fragment content (Rv, 0% 30%, which was determined according the results of field investigation for rock fragment distribution) on the other were investigated. Thirdly, systematic analysis about the

  17. Mass measurements of {sup 238}U-projectile fragments for the first time with a multiple-reflection time-of-flight mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Jens

    2016-07-01

    Mass measurements of short-lived uranium projectile fragments were performed for the first time with a Multiple-Reflexion-Time-of-Flight Mass Spectrometer (MR-TOF-MS). A major part of this doctoral work was a novel development of a data analysis method for the MR-TOF-MS mass measurements of exotic nuclei at the fragment separator FRS at GSI. The developed method was successfully applied to the data obtained from two pilot experiments with the MR-TOF-MS at the FRS in 2012 and 2014. A substantial upgrade of the experimental setup of the MR-TOF-MS was also performed in the frame work of this doctoral thesis after the first run. In the experiments projectile fragments were created with 1000 MeV/u {sup 238}U ions in a Be/Nb target at the entrance of the in-flight separator FRS. The exotic nuclei were spatially separated, energy bunched and slowed down with the ion-optical system of the FRS combined with monoenergetic and homogeneous degraders. At the final focal plane of the FRS the fragments were completely slowed down and thermalized in a cryogenic stopping cell (CSC) filled with 3-5 mg/cm{sup 2} pure helium gas. The exotic nuclei were fast extracted from the CSC to enable mass measurements of very short-lived fragments with the MR-TOF-MS. The achievement of this goal was successfully demonstrated with the mass measurement of {sup 220}Ra ions with a half-life of 17.9 ms and 11 detected events. The mass measurements of the isobars {sup 211}Fr, {sup 211}Po and {sup 211}Rn have clearly demonstrated the scientific potential of the MR-TOF-MS for the investigation of exotic nuclei and the power of the data analysis system. Difficult measurements with overlapping mass distributions with only a few counts in the measured spectra were the challenge for the new data analysis method based on the maximum likelihood method. The drifts during the measurements were corrected with the developed time-resolved calibration method. After the improvements of the setup as a consequence of

  18. The jet mass distribution after Soft Drop

    Science.gov (United States)

    Marzani, Simone; Schunk, Lais; Soyez, Gregory

    2018-02-01

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects.

  19. Regularity and mass conservation for discrete coagulation–fragmentation equations with diffusion

    KAUST Repository

    Cañizo, J.A.

    2010-03-01

    We present a new a priori estimate for discrete coagulation-fragmentation systems with size-dependent diffusion within a bounded, regular domain confined by homogeneous Neumann boundary conditions. Following from a duality argument, this a priori estimate provides a global L2 bound on the mass density and was previously used, for instance, in the context of reaction-diffusion equations. In this paper we demonstrate two lines of applications for such an estimate: On the one hand, it enables to simplify parts of the known existence theory and allows to show existence of solutions for generalised models involving collision-induced, quadratic fragmentation terms for which the previous existence theory seems difficult to apply. On the other hand and most prominently, it proves mass conservation (and thus the absence of gelation) for almost all the coagulation coefficients for which mass conservation is known to hold true in the space homogeneous case. © 2009 Elsevier Masson SAS. All rights reserved.

  20. Invariant mass distributions in cascade decays

    International Nuclear Information System (INIS)

    Miller, David J.; Osland, Per; Raklev, Are R.

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D→Cc→Bbc→Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through 'feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be included in the distributions

  1. Charge distributions of fission fragments of low- and high-energy fission of Fm, No, and Rf isotopes

    Science.gov (United States)

    Paşca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.

    2018-03-01

    The charge (mass) distributions of fission fragments resulting from low- and high-energy fission of the even-even nuclei 254 -260 ,264Fm , 258 -264No , and 262 -266Rf are studied with the statistical scission-point model. The calculated results are compared with the available experimental data. In contrast to the experimental data, the calculated mass distribution for 258Fm (s.f.) is strikingly similar to the experimental one for 257Fm (s.f.). The transformation of the shape of charge distribution with increasing isospin and excitation energy occurs gradually and in a similar fashion like that of the mass distribution, but slower. For 254Fm(i.f.), 257Fm(nt h,f), and 260Fm (s.f.), the unexpected difference (symmetric or asymmetric) between the shapes of charge and mass distributions is predicted for the first time. At some critical excitation energy, the saturation of the symmetric component of charge (mass) yields is demonstrated.

  2. Differential fragmentation patterns of pectin oligogalacturonides observed by nanoelectrospray quadrupole ion-trap mass spectrometry using automated spectra interpretation

    DEFF Research Database (Denmark)

    Mutenda, Kudzai E; Matthiesen, Rune; Roepstorff, Peter

    2007-01-01

    Oligogalacturonides of different degrees of polymerization (DP) and methyl esterification (DE) were structurally analyzed by nanoESI quadrupole ion-trap mass spectrometry. The fragmentation patterns of the oligogalacturonides were compared using the program 'Virtual Expert Mass Spectrometrist...... with free carboxylic acid groups underwent higher water loss compared to fully methyl-esterified oligogalacturonides under the same fragmentation conditions. Cross-ring cleavage, in which fragmentation occurs across the ring system of the galacturonate residue and signified by unique mass losses...... water loss than methyl-esterified ones will be postulated. In addition, the VEMS program was extended to automatically interpret and assign the fragment ions peaks generated in this study....

  3. Mass and charge distributions in Fe-induced reactions

    International Nuclear Information System (INIS)

    Madani, H.; Mignerey, A.C.; Marchetti, A.A.; Weston-Dawkes, A.P.; Kehoe, W.L.; Obenshain, F.

    1995-01-01

    The charge and mass of the projectile-like fragments produced in the 12-MeV/nucleon 56 Fe + 165 Ho reaction were measured at a laboratory scattering angle of 16 degrees. The mass and charge distributions of the projectile-like fragments were generated as a function of total kinetic energy loss (TKEL), and characterized by their neutron and proton centroids and variances, and correlation factors. A weak drift of the system towards mass asymmetry, opposite to the direction which minimizes the potential energy of the composite system, was observed. The increase in the variances with energy loss is consistent with a nucleon exchange mechanism as a means for energy dissipation. Predictions of two nucleon exchange models, Randrup's and, Tassan-Got's models, are compared to the experimental results of the 672-MeV 56 Fe + 165 Ho reaction and to other Fe-induced reactions. The proton and neutron centroids were found to be generally better reproduced by Tassan-Got's model than by Randrup's model. The variances and correlation factor are well reproduced for asymmetric systems by both models

  4. Angular distribution of photofission fragments in 238U at 5.43 MeV

    International Nuclear Information System (INIS)

    Kuniyoshi, S.; Mafra, O.Y.; Renner, C.; Goldemberg, J.

    1974-01-01

    The angular distribution of photofission fragments of 238 U, produced by 5.43 MeV monochromatic photons from the eta,γ reaction in sulphur, has been measured using glass plates as detectors. In the analysis of the results only the contributions from the (J sup(π), K) 1= (1 - ,0), (1 - ,1) and (2 + ,0) terms were considered. The coefficients of the angular distributions of the fission fragments were obtained. An analysis of the data available in the literature on the angular distribution near the photofission threshold is also presented

  5. Angular distribution of photofission fragments in 238U at 5.43 MeV

    International Nuclear Information System (INIS)

    Kuniyoshi, Susumo

    1973-01-01

    The angular distribution of photofission fragments of 238 U, produced by 5.43 MeV monochromatic photons from the η,γ reaction in sulphur, has been measured using glass plates as detectors. In the analysis of the results only the contributions from the (J π , K) 1= (1 - ,0), (1 - ,1) and (2 + ,0) terms were considered. The coefficients of the angular distributions of the fission fragments were obtained. An analysis of the data available in the literature on the angular distribution near the photofission threshold is also presented. (author)

  6. Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment

    OpenAIRE

    Syvänen, Stina; Edén, Desireé; Sehlin, Dag

    2017-01-01

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to d...

  7. Angular distributions of target black fragments in nucleus–nucleus collisions at high energy

    International Nuclear Information System (INIS)

    Liu, Fuhu; Abd Allah, N.N.; Zhang, Donghai; Duan, Maiying

    2003-01-01

    The experimental results of space, azimuthal, and projected angular distributions of target black fragments produced in silicon-emulsion collisions at 4.5A GeV/c (the Dubna energy) are reported. A multi-source ideal gas model is suggested to describe the experimental angular distributions. The Monte Carlo calculated results are in agreement with the experimental data. (author)

  8. Characterizing the spatial distribution of giant pandas (Ailuropoda melanoleuca) in fragmented forest landscapes

    NARCIS (Netherlands)

    Wang, T.; Ye, X.P.; Skidmore, A.K.; Toxopeus, A.G.

    2010-01-01

    Aim. To examine the effects of forest fragmentation on the distribution of the entire wild giant panda (Ailuropoda melanoleuca) population, and to propose a modelling approach for monitoring the spatial distribution and habitat of pandas at the landscape scale using Moderate Resolution Imaging

  9. Global climate change and fragmentation of native brook trout distribution in the southern Appalachian Mountains

    Science.gov (United States)

    Patricia A. Flebbe

    1997-01-01

    Current distributions of native brook trout (Salvelinus fontinalis) in the Southern Appalachians are restricted to upper elevations by multiple factors, including habitat requirements, introduced rainbow (Oncorhynchus mykiss) and brown (Salmo trutta) trout, and other human activities. Present-day distribution of brook trout habitat is already fragmented. Increased...

  10. Charge distributions and correlations in fragmentation models for soft hadron collisions

    International Nuclear Information System (INIS)

    Wolf, E.A. de

    1984-01-01

    Data on charge distributions and charge correlations in pp and meson-proton interactions at PS and SPS energies are successfully compared with the Lund fragmentation model for low-psub(T) hadron collisions. It is argued that local conservation of quantum numbers and resonance production, as implemented in fragmentation models, are sufficient ingredients to explain most of the available experimental results at these energies. No necessity is found for dual-sheet contributions considered in DTU-based parton models. (orig.)

  11. Fragment ion distribution in charge-changing collisions of 2-MeV Si ions with C60

    Science.gov (United States)

    Itoh, A.; Tsuchida, H.; Miyabe, K.; Majima, T.; Nakai, Y.

    2001-09-01

    We have measured positive fragment ions produced in collisions of 2 MeV Siq+ (q=0, 1, 2, 4) projectiles with a C60 molecular target. The measurement was performed with a time-of-flight coincidence method between fragment ions and charge-selected outgoing projectiles. For all the charge-changing collisions investigated here, the mass distribution of small fragment ions C+n (n=1-12) can be approximated fairly well by a power-law form of n-λ as a function of the cluster size n. The power λ derived from each mass distribution is found to change strongly according to different charge-changing collisions. As a remarkable experimental finding, the values of λ(loss) in electron loss collisions are almost the same for the same final charge states k irrespective of the initial charge q, exhibiting a nearly perfect linear relationship with k. We also performed calculations of the projectile ionization on the basis of the semiclassical approximation and obtained inelastic energy deposition for individual collision processes. The estimated energy deposition is found to have a simple correlation with the experimentally determined values of λ(loss).

  12. Charmed-meson fragmentation functions with finite-mass corrections and their application in various processes

    Energy Technology Data Exchange (ETDEWEB)

    Kneesch, Torben

    2010-12-15

    We have calculated the single-inclusive production cross section of massive quarks in electron-positron-annihilation with next-to-leading order QCD corrections. With these results we have extracted fragmentation functions for the fragmentation from partons into D{sup 0}, D{sup +} and D{sup *} mesons, where we have used experimental data from the B factories Belle and CLEO and from the ALEPH and OPAL experiments at the LEP collider. In our analysis we have included the masses of c and b quarks and of the D mesons and tested the evolution of fragmentation functions with a global fit spanning the B factories' center-of-mass energy of {radical}(s)=10.5 GeV to LEP's run at the Z boson resonance at M{sub Z}. We have applied this fragmentation functions in deep inelastic scattering for comparisons with HERA data using parton cross sections from the literature available in program form. We have then modified this cross section to calculate predictions for deep inelastic two-photon-scattering. By applying the Weizsaecker-Williams spectrum on the real photon we have calculated predictions for LEP1, LEP2 and the future ILC experiments. For ILC we have also included a beamstrahlung spectrum. Finally we have calculated production cross sections for the planned e{gamma} mode of the ILC with the help of a Compton spectrum. (orig.)

  13. Invariant mass distributions in cascade decays

    CERN Document Server

    Miller, D J; Raklev, A R

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D -> Cc -> Bbc -> Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through `feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be inclu...

  14. The particle size distribution of fragmented melt debris from molten fuel coolant interactions

    International Nuclear Information System (INIS)

    Fletcher, D.F.

    1984-04-01

    Results are presented of a study of the types of statistical distributions which arise when examining debris from Molten Fuel Coolant Interactions. The lognormal probability distribution and the modifications of this distribution which result from the mixing of two distributions or the removal of some debris are described. Methods of fitting these distributions to real data are detailed. A two stage fragmentation model has been developed in an attempt to distinguish between the debris produced by coarse mixing and fine scale fragmentation. However, attempts to fit this model to real data have proved unsuccessful. It was found that the debris particle size distributions from experiments at Winfrith with thermite generated uranium dioxide/molybdenum melts were Upper Limit Lognormal. (U.K.)

  15. BINARY FORMATION MECHANISMS: CONSTRAINTS FROM THE COMPANION MASS RATIO DISTRIBUTION

    International Nuclear Information System (INIS)

    Reggiani, Maddalena M.; Meyer, Michael R.

    2011-01-01

    We present a statistical comparison of the mass ratio distribution of companions, as observed in different multiplicity surveys, to the most recent estimate of the single-object mass function. The main goal of our analysis is to test whether or not the observed companion mass ratio distribution (CMRD) as a function of primary star mass and star formation environment is consistent with having been drawn from the field star initial mass function (IMF). We consider samples of companions for M dwarfs, solar-type stars, and intermediate-mass stars, both in the field as well as clusters or associations, and compare them with populations of binaries generated by random pairing from the assumed IMF for a fixed primary mass. With regard to the field we can reject the hypothesis that the CMRD was drawn from the IMF for different primary mass ranges: the observed CMRDs show a larger number of equal-mass systems than predicted by the IMF. This is in agreement with fragmentation theories of binary formation. For the open clusters α Persei and the Pleiades we also reject the IMF random-pairing hypothesis. Concerning young star-forming regions, currently we can rule out a connection between the CMRD and the field IMF in Taurus but not in Chamaeleon I. Larger and different samples are needed to better constrain the result as a function of the environment. We also consider other companion mass functions and we compare them with observations. Moreover the CMRD both in the field and clusters or associations appears to be independent of separation in the range covered by the observations. Combining therefore the CMRDs of M (1-2400 AU) and G (28-1590 AU) primaries in the field and intermediate-mass primary binaries in Sco OB2 (29-1612 AU) for mass ratios, q = M 2 /M 1 , from 0.2 to 1, we find that the best chi-square fit follows a power law dN/dq∝q β , with β = -0.50 ± 0.29, consistent with previous results. Finally, we note that the Kolmogorov-Smirnov test gives a ∼1

  16. The jet mass distribution after Soft Drop

    Energy Technology Data Exchange (ETDEWEB)

    Marzani, Simone [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN, Sezione di Genova (Italy); Schunk, Lais [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Soyez, Gregory [IPhT, CEA Saclay, CNRS UMR 3681, Gif-Sur-Yvette (France)

    2018-02-15

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects. (orig.)

  17. Coupling of mass and charge distributions for low excited nuclear fission

    International Nuclear Information System (INIS)

    Salamatin, V.S.; )

    2000-01-01

    The simple model for calculation of charge distributions of fission fragments for low exited nuclear fission from experimental mass distributions is offered. The model contains two parameters, determining amplitude of even-odd effect of charge distributions and its dependence on excitation energy. Results for reactions 233 U(n th ,f), 235 U(n th ,f), 229 Th(n th ,f), 249 Cf(n th ,f) are spent [ru

  18. Kriterijum efikasnosti i optimizacija mase fragmenta projektila parčadnog dejstva / Efficiency criterion and optimization of fragment mass in fragmentation projectiles

    Directory of Open Access Journals (Sweden)

    Predrag Elek

    2003-07-01

    Full Text Available U radu se razmatra problem optimizacije mase parčadi koja nastaju fragmentacijom projektila parčadnog dejstva. Pokazano je da optimalna masa parčeta prvenstveno zavisi od njegovih kinetičkih karakteristika na cilju kao i od usvojenog kriterijuma efikasnosti. Proračuni pokazuju da su postojeći kriterijumi, minimalna zahtevana kinetička energija fragmenta odnosno minimalna kinetička energija po jedinici napadne površine, nesaglasni - odnosno da daju bitno različite vrednosti optimalne mase. Zaključeno je da kriterijum specifične energije parčeta podrazumeva manju masu optimalnog parčeta i ukazuje na značaj parčadi veoma male mase sa stanovišta efikasnosti. Jasno je da ovako određena optimalna masa efikasnog parčeta predstavlja veoma važan parametar projektila parčadnog dejstva, pa je neophodna eksperimentalna verifikacija dobijenih teorijskih rezultata. / This paper considers the problem of optimizing the mass of HE projectile fragments. It is shown that the optimum fragment mass is a function of its kinetic characteristics at the target and an adopted efficiency criterion. Computations show that the most prominent criteria, minimum required kinetic energy and minimum kinetic energy per unit of cross--sectional area, are incompatible - i. e. they provide significantly different values of the optimum mass. It is concluded that the criterion of specific kinetic energy corresponds to a lower optimum fragment mass, which indicates the importance of fragments of low masses from the aspect of efficiency. The theoretically determined optimum fragment mass represents a very significant parameter for design optimization of fragmentation projectiles, but experimental verification of obtained results is essentially important as well.

  19. Reconsideration of mass-distribution models

    Directory of Open Access Journals (Sweden)

    Ninković S.

    2014-01-01

    Full Text Available The mass-distribution model proposed by Kuzmin and Veltmann (1973 is revisited. It is subdivided into two models which have a common case. Only one of them is subject of the present study. The study is focused on the relation between the density ratio (the central one to that corresponding to the core radius and the total-mass fraction within the core radius. The latter one is an increasing function of the former one, but it cannot exceed one quarter, which takes place when the density ratio tends to infinity. Therefore, the model is extended by representing the density as a sum of two components. The extension results into possibility of having a correspondence between the infinite density ratio and 100% total-mass fraction. The number of parameters in the extended model exceeds that of the original model. Due to this, in the extended model, the correspondence between the density ratio and total-mass fraction is no longer one-to-one; several values of the total-mass fraction can correspond to the same value for the density ratio. In this way, the extended model could explain the contingency of having two, or more, groups of real stellar systems (subsystems in the diagram total-mass fraction versus density ratio. [Projekat Ministarstva nauke Republike Srbije, br. 176011: Dynamics and Kinematics of Celestial Bodies and Systems

  20. Angular distribution measurement of fragment ions from a molecule using a new beamline consisting of a Grasshopper monochromator

    Science.gov (United States)

    Saito, Norio; Suzuki, Isao H.; Onuki, Hideo; Nishi, Morotake

    1989-07-01

    Optical characteristics of a new beamline consisting of a premirror, a Grasshopper monochromator, and a refocusing mirror have been investigated. The intensity of the monochromatic soft x-ray was estimated to be about 108 photons/(s 100 mA) at 500 eV with the storage electron energy of 600 MeV and the minimum slit width. This slit width provides a resolution of about 500. Angular distributions of fragment ions from an inner-shell excited nitrogen molecule have been measured with a rotatable time-of-flight mass spectrometer by using this beamline.

  1. Angular distribution measurement of fragment ions from a molecule using a new beamline consisting of a Grasshopper monochromator

    International Nuclear Information System (INIS)

    Saito, N.; Suzuki, I.H.; Onuki, H.; Nishi, M.

    1989-01-01

    Optical characteristics of a new beamline consisting of a premirror, a Grasshopper monochromator, and a refocusing mirror have been investigated. The intensity of the monochromatic soft x-ray was estimated to be about 10 8 photons/(s 100 mA) at 500 eV with the storage electron energy of 600 MeV and the minimum slit width. This slit width provides a resolution of about 500. Angular distributions of fragment ions from an inner-shell excited nitrogen molecule have been measured with a rotatable time-of-flight mass spectrometer by using this beamline

  2. In silico fragmentation for computer assisted identification of metabolite mass spectra

    Directory of Open Access Journals (Sweden)

    Müller-Hannemann Matthias

    2010-03-01

    Full Text Available Abstract Background Mass spectrometry has become the analytical method of choice in metabolomics research. The identification of unknown compounds is the main bottleneck. In addition to the precursor mass, tandem MS spectra carry informative fragment peaks, but the coverage of spectral libraries of measured reference compounds are far from covering the complete chemical space. Compound libraries such as PubChem or KEGG describe a larger number of compounds, which can be used to compare their in silico fragmentation with spectra of unknown metabolites. Results We created the MetFrag suite to obtain a candidate list from compound libraries based on the precursor mass, subsequently ranked by the agreement between measured and in silico fragments. In the evaluation MetFrag was able to rank most of the correct compounds within the top 3 candidates returned by an exact mass query in KEGG. Compared to a previously published study, MetFrag obtained better results than the commercial MassFrontier software. Especially for large compound libraries, the candidates with a good score show a high structural similarity or just different stereochemistry, a subsequent clustering based on chemical distances reduces this redundancy. The in silico fragmentation requires less than a second to process a molecule, and MetFrag performs a search in KEGG or PubChem on average within 30 to 300 seconds, respectively, on an average desktop PC. Conclusions We presented a method that is able to identify small molecules from tandem MS measurements, even without spectral reference data or a large set of fragmentation rules. With today's massive general purpose compound libraries we obtain dozens of very similar candidates, which still allows a confident estimate of the correct compound class. Our tool MetFrag improves the identification of unknown substances from tandem MS spectra and delivers better results than comparable commercial software. MetFrag is available through a web

  3. Correlations of intermediate mass fragments from Fe+Ta, Au, and Th collisions

    International Nuclear Information System (INIS)

    Sangster, T.C.; Begemann-Blaich, M.; Blaich, T.; Britt, H.C.; Hansen, L.F.; Namboodiri, M.N.; Peilert, G.

    1995-01-01

    Charge, velocity, and angular correlations between intermediate mass fragments (IMF) are presented for 50 and 100 MeV/nucleon Fe bombardments of Ta, Au, and Th targets. Correlation functions generated as a function of the relative velocity and the opening angle between two IMF's are qualitatively independent of the projectile energy and target mass and show a suppression at small relative velocities and opening angles due to the Coulomb repulsion between the fragments. The correlations are consistent with IMF's emitted primarily from a highly excited target residue following a rapid preequilibrium cascade. The correlation data are compared to model calculations using the event generator MENEKA and the quantum molecular dynamics (QMD) code with a statistical deexcitation of residual fragments utilizing the multifragmentation code SMM. All data are consistent with a simultaneous multifragmentation at a freeze-out density of 0.1--0.3 times normal nuclear matter density or a more sequential emission with time constant τ≤500 fm/c

  4. Gas-phase fragmentation of peptides to increase the spatial resolution of the Hydrogen Exchange Mass Spectrometry experiment

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    are produced after precursor ion selection and thus do not add complexity to the LC-MS analysis. The key to obtaining optimal spatial resolution in a hydrogen exchange mass spectrometry (HX-MS) experiment is the fragmentation efficiency. This chapter discusses common fragmentation techniques like collision....../D scrambling, thus making them suitable for HX applications. By combining the classic bottom-up HX-MS workflow with gas-phase fragmentation by ETD, detailed information on protein HX can be obtained....

  5. A Microchannel Inlet to Reduce High-Velocity Impact Fragmentation of Molecules in Orbital and Fly-by Mass Spectrometers

    Science.gov (United States)

    Turner, Brandon; Anupriya, Anupriya; Sevy, Eric; Austin, Daniel E.

    2017-10-01

    Closed source neutral mass spectrometers are often used on flyby missions to characterize the molecular components of planetary exospheres. In a typical closed source, neutrals are thermalized as they deflect off the walls within a spherical antechamber prior to ionization and mass analysis. However, the high kinetic energy of each molecule as it impacts the chamber can lead to fragmentation before the ionization region is reached. Due to this fragmentation, the original composition of the molecule can be altered, leading to ambiguous identification.Even knowing the fragmentation pathways that occur may not allow deconvolution of data to give the correct composition. Only stable, volatile fragments will be observed in the subsequent mass spectrometer and different organic compounds likely give similar fragmentation products. Simply detecting these products will not lead to unambiguous identication of the precursor molecules. Here, we present a hardware solution to this problem—an inlet that reduces the fragmentation of molecules that impact at high velocities.We present a microchannel inlet that reduces the impact fragmentation by allowing the molecules to dissipate kinetic energy faster than their respective dissociation lifetimes. Preliminary calculations indicate that impact-induced fragmentation will be reduced up to three orders of magnitude compared with conventional closed sources by using this inlet. The benefits of such an inlet apply to any orbital or flyby velocity. The microchannel inlet enables detection of semi-volatile molecules that were previously undetectable due to impact fragmentation.

  6. Competition and fragmentation: a simple model generating lognormal-like distributions

    International Nuclear Information System (INIS)

    Schwaemmle, V; Queiros, S M D; Brigatti, E; Tchumatchenko, T

    2009-01-01

    The current distribution of language size in terms of speaker population is generally described using a lognormal distribution. Analyzing the original real data we show how the double-Pareto lognormal distribution can give an alternative fit that indicates the existence of a power law tail. A simple Monte Carlo model is constructed based on the processes of competition and fragmentation. The results reproduce the power law tails of the real distribution well and give better results for a poorly connected topology of interactions.

  7. The grain-size distribution of pyroclasts: Primary fragmentation, conduit sorting or abrasion?

    Science.gov (United States)

    Kueppers, U.; Schauroth, J.; Taddeucci, J.

    2013-12-01

    Explosive volcanic eruptions expel a mixture of pyroclasts and lithics. Pyroclasts, fragments of the juvenile magma, record the state of the magma at fragmentation in terms of porosity and crystallinity. The grain size distribution of pyroclasts is generally considered to be a direct consequence of the conditions at magma fragmentation that is mainly driven by gas overpressure in bubbles, high shear rates, contact with external water or a combination of these factors. Stress exerted by any of these processes will lead to brittle fragmentation by overcoming the magma's relaxation timescale. As a consequence, most pyroclasts exhibit angular shapes. Upon magma fragmentation, the gas pyroclast mixture is accelerated upwards and eventually ejected from the vent. The total grain size distribution deposited is a function of fragmentation conditions and transport related sorting. Porous pyroclasts are very susceptible to abrasion by particle-particle or particle-conduit wall interaction. Accordingly, pyroclastic fall deposits with angular clasts should proof a low particle abrasion upon contact to other surfaces. In an attempt to constrain the degree of particle interaction during conduit flow, monomodal batches of washed pyroclasts have been accelerated upwards by rapid decompression and subsequently investigated for their grain size distribution. In our set-up, we used a vertical cylindrical tube without surface roughness as conduit. We varied grain size (0.125-0.25; 0.5-1; 1-2 mm), porosity (0; 10; 30 %), gas-particle ratio (10 and 40%), conduit length (10 and 28 cm) and conduit diameter (2.5 and 6 cm). All ejected particles were collected after settling at the base of a 3.3 m high tank and sieved at one sieve size below starting size (half-Φ). Grain size reduction showed a positive correlation with starting grain size, porosity and overpressure at the vent. Although milling in a volcanic conduit may take place, porous pyroclasts are very likely to be a primary product

  8. The Study of Prompt and Delayed Muon Induced Fission. I.Total kinetic energies and mass distributions

    NARCIS (Netherlands)

    David, P; Hartfiel, J.; Janszen, H.; Petitjean, C.; Reist, H.W.; Polikanov, S.M.; Konijn, J.; Laat, de C.T.A.M.; Taal, A.; Krogulski, T.; Johansson, T.; Tibell, G.; Achard van Enschut, d' J.F.M.

    1987-01-01

    Mass yield and total kinetic energy release (TKE) distributions of fragments from prompt and delayed muon induced fission, separately, have been measured for the isotopes235U,238U,237Np and242Pu. The distributions from prompt muon induced fission are compared with the corresponding distributions

  9. [Determination of strobilurin fungicides in fruits and their mass fragmentation routes by ultra performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhou, Yao; Yang, Huiqin; Shi, Yiyin; Chen, Jiaxian; Zhu, Jian; Deng, Xiaojun; Guo, Dehua

    2017-09-08

    A method was developed for the simultaneous determination of six strobilurin fungicide ( E -metominostrobin, azoxystrobin, kresoxim-methyl, picoxystrobin, pyraclostrobin and trifloxystrobin) residues in orange, banana, apple and pineapple samples by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The fragmentation routes of all the compounds were explained by the aid of a fragment predicting software ACD Lab/MS Fragmenter. The samples were extracted by acetonitrile, then cleaned up by amino solid phase extraction cartridges (SupelClean LC-NH 2 ). The extracts were separated on a ACQUITY UPLC BEH C 18 column (50 mm×2.1 mm, 1.7 μm) with gradient elution. Acetonitrile containing 0.1% (v/v) formic acid and 10 mmol/L ammonium acetate containing 0.1% (v/v) formic acid were used as mobile phases. The samples were detected by electrospray ionization (ESI)-MS/MS in positive ion and multiple reaction monitoring (MRM) mode, quantified by external standard method. Good linearities were obtained in the range of 5-100 μg/L (for pyraclostrobin, 1-20 μg/L) with correlation coefficients ( r 2 ) greater than 0.999. The recoveries ranged from 60.4% to 120% with the relative standard deviations between 2.15% and 15.1% ( n =6). The developed method can meet the inspection of the six strobilurin residues in the orange, banana, apple and pineapple samples.

  10. A theoretical and mass spectrometry study of the fragmentation of mycosporine-like amino acids

    Science.gov (United States)

    Cardozo, Karina H. M.; Vessecchi, Ricardo; Carvalho, Valdemir M.; Pinto, Ernani; Gates, Paul J.; Colepicolo, Pio; Galembeck, Sérgio E.; Lopes, Norberto P.

    2008-06-01

    In the present study, the mycosporine-like amino acids (MAAs) were isolated from the marine red alga Gracilaria tenuistipitata and analysed by high-resolution accurate-mass sequential mass spectrometry (MSn). In addition to the proposed fragmentation mechanism based on the MSn analysis, it is clearly demonstrated that the elimination of mass 15 is a radical processes taking place at the methoxyl substituent of the double bond. This characteristic loss of a methyl radical was studied by theoretical calculations and the homolytic cleavage of the OC bond is suggested to be dependent on the bond weakening. The protonation site of the MAAs was indicated by analysis of the Fukui functions and the relative Gibbs energies of the several possible protonated forms.

  11. Mass Distribution in Galaxy Cluster Cores

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, M. T.; McNamara, B. R.; Pulido, F.; Vantyghem, A. N. [Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1 (Canada); Nulsen, P. E. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Russell, H. R. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Edge, A. C. [Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Main, R. A., E-mail: m4hogan@uwaterloo.ca [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON, M5S 3H8 (Canada)

    2017-03-01

    Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and active galactic nucleus feedback, are dependent upon local dynamical timescales. However, accurate mapping of the mass distribution within individual clusters is challenging, particularly toward cluster centers where the total mass budget has substantial radially dependent contributions from the stellar ( M {sub *}), gas ( M {sub gas}), and dark matter ( M {sub DM}) components. In this paper we use a small sample of galaxy clusters with deep Chandra observations and good ancillary tracers of their gravitating mass at both large and small radii to develop a method for determining mass profiles that span a wide radial range and extend down into the central galaxy. We also consider potential observational pitfalls in understanding cooling in hot cluster atmospheres, and find tentative evidence for a relationship between the radial extent of cooling X-ray gas and nebular H α emission in cool-core clusters. At large radii the entropy profiles of our clusters agree with the baseline power law of K ∝ r {sup 1.1} expected from gravity alone. At smaller radii our entropy profiles become shallower but continue with a power law of the form K ∝ r {sup 0.67} down to our resolution limit. Among this small sample of cool-core clusters we therefore find no support for the existence of a central flat “entropy floor.”.

  12. Neighbouring charge fragmentations in low energy fission

    International Nuclear Information System (INIS)

    Montoya, M.

    1986-10-01

    Shell and odd-even effects in fission have been largely studied until now. The structure in fragment mass, charge and kinetic energy distributions of fragments were interpreted as shell and even-odd effects. In this paper, we want to show that the discret change of fragment charge symmetry should produce also structures in those distribution. 19 refs

  13. Deeply inelastic collisions as a source of intermediate mass fragments at E/A = 27 MeV

    International Nuclear Information System (INIS)

    Borderie, B.; Montoya, M.; Rivet, M.F.; Jouan, D.; Cabot, C.; Fuchs, H.; Gardes, D.; Gauvin, H.; Jacquet, D.; Monnet, F.

    1988-01-01

    Intermediate-mass fragments detected in coincidence with heavy residues were measured in 40 Ar induced reactions on Ag at E/A = 27 MeV. From the observed characteristics, it is inferred that intermediate-mass fragments associated with the so-called intermediate-velocity source come mainly from deeply inelastic collisions occurring after or at the same time as preequilibrium particle emission. (orig.)

  14. Search for ternary fragmentation in the reaction 856 MeV 98Mo + 51V: Kinematic probing of intermediate-mass-fragment emissions

    International Nuclear Information System (INIS)

    Vardaci, Emanuele; Kaplan, Morton; Parker, Winifred E.; Moses, David J.; Boger, J.T.; Gilfoyle, G.T.; McMahan, M.A.; Montoya, M.

    2000-05-01

    A new technique has been applied to coincidence measurements between fission fragments (FF) and intermediate mass fragments (IMF) emitted from the composite system 149 65 Tb at an excitation energy of 224 MeV. The method permits simultaneous observation of IMF emissions along and normal to the FF separation axes. For the integrated total of 0.10 +-0.02 IMF emitted per fission, we find no significant correlation with FF direction, suggesting that IMFs associated with fission reactions are predominantly emitted from the system prior to fission

  15. Fragmentation of toxicologically relevant drugs in positive-ion liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Niessen, W M A

    2011-01-01

    The identification of drugs and related compounds by LC-MS-MS is an important analytical challenge in several application areas, including clinical and forensic toxicology, doping control analysis, and environmental analysis. Although target-compound based analytical strategies are most frequently applied, at some point the information content of the MS-MS spectra becomes relevant. In this article, the positive-ion MS-MS spectra of a wide variety of drugs and related substances are discussed. Starting point was an MS-MS mass spectral library of toxicologically relevant compounds, available on the internet. The positive-ion MS-MS spectra of ∼570 compounds were interpreted by chemical and therapeutic class, thus involving a wide variety of drug compound classes, such benzodiazepines, beta-blockers, angiotensin-converting enzyme inhibitors, phenothiazines, dihydropyridine calcium channel blockers, diuretics, local anesthetics, vasodilators, as well as various subclasses of anti-diabetic, antidepressant, analgesic, and antihistaminic drugs. In addition, the scientific literature was searched for available MS-MS data of these compound classes and the interpretation thereof. The results of this elaborate study are presented in this article. For each individual compound class, the emphasis is on class-specific fragmentation, as discussing fragmentation of all individual compounds would take far too much space. The recognition of class-specific fragmentation may be quite informative in determining the compound class of a specific unknown, which may further help in the identification. In addition, knowledge on (class-specific) fragmentation may further help in the optimization of the selectivity in targeted analytical approaches of compounds of one particular class. Copyright © 2011 Wiley Periodicals, Inc.

  16. Determination of size distribution of small DNA fragments by polyacrylamide gel electrophoresis

    International Nuclear Information System (INIS)

    Lau How Mooi

    1998-01-01

    Size distribution determination of DNA fragments can be normally determined by the agarose gel electrophoresis, including the normal DNA banding pattern analysis. However this method is only good for large DNA, such as the DNA of the size of kilo base pairs to mega base pairs range. DNA of size less than kilo base pairs is difficult to be quantified by the agarose gel method. Polyacrylamide gel electrophoresis however can be used to measure the quantity of DNA fragments of size less than kilo base pairs in length, down to less than ten base pairs. This method is good for determining the quantity of the smaller size DNA, single stranded polymers or even some proteins, if the known standards are available. In this report detail description of the method of preparing the polyacrylamide gel, and the experimental set up is discussed. Possible uses of this method, and the comparison with the standard sizes of DNA is also shown. This method is used to determine the distribution of the amount of the fragmented DNA after the Calf-thymus DNA has been exposed to various types of radiation and of different doses. The standards were used to determine the sizes of the fragmented Calf-thymus DNA. The higher the dose the higher is the amount of the smaller size DNA measured

  17. Optimizing recoil-isomer tagging with the Argonne fragment mass analyzer

    International Nuclear Information System (INIS)

    Garnsworthy, A.B.; Lister, C.J.; Regan, P.H.; Blank, B.B.; Cullen, I.J.; Gros, S.; Henderson, D.J.; Jones, G.A.; Liu, Z.; Seweryniak, D.; Shumard, B.R.; Thompson, N.J.; Williams, S.J.; Zhu, S.

    2008-01-01

    A new focal plane detector arrangement for the Fragment Mass Analyzer (FMA) has been built and tested at Argonne National Laboratory. This set-up is particularly sensitive for performing Recoil-Isomer Tagging on nuclei with isomeric states with lifetimes in the microsecond range. Recoiling nuclei from fusion-evaporation reactions at the target position are dispersed by their ratio of mass to charge (A/q) by the FMA and stopped in low pressure gas (air) at the focal plane. Subsequent gamma decays from isomeric states in the reaction products are observed using Ge detectors. A constant gas flow through the focal plane chamber efficiently removes longer-lived beta-decaying species from sight of the detectors. This set-up has been commissioned successfully with the microsecond isomer in 80 Rb, populated via the 52 Cr( 32 S, 3pn) reaction at 135 MeV

  18. Fragments emission from light mass composite nuclei within collective clusterization mechanism

    International Nuclear Information System (INIS)

    Singh, BirBikram

    2016-01-01

    Based on the quantum mechanical fragmentation theory (QMFT) the dynamical cluster decay model (DCM) has been developed by Gupta and Collaborators to study the decay of hot and rotating compound systems. Number of compound nuclei (CN) in different mass regions have been studied quite extensively while taking into consideration nuclear structure effects in the same. It is quite relevant to mention here that in the binary decay of CN nuclear structure effects comes into picture, within DCM, via preformation probability P_0 of the complimentary fragments before penetrating the potential barrier between them with certain probability P . It is interesting to note here that the statistical models treat various decay modes of the CN on different footing contrary to the DCM. In very light mass region the decay of number of composite systems "2"0","2"1","2"2Ne*, "2"6"-"2"9Al, "2"8Si, "3"1P, "3"2S, "3"9K and "4"0Ca*, formed in low energy heavy ion reactions, have been investigated for different reaction mechanisms particularly fusion-fission (FF) and deep inelastic orbiting (DIO) from equilibrated and non-equilibrated compound nucleus processes, respectively

  19. Fission fragment angular distribution in the reaction 28Si+176Yb

    International Nuclear Information System (INIS)

    Tripathi, R.; Sudarshan, K.; Sharma, S.K.; Reddy, A.V.R.; Pujari, P.K.; Dutta, D.; Goswami, A.; Ramachandran, K.

    2009-01-01

    Fission fragment angular distribution has been measured in the reaction 28 Si+ 176 Yb at beam energies of 145 and 155 MeV to investigate the contribution from non-compound nucleus fission. Experiments were carried out at BARC-TIFR Pelletron-LINAC accelerator facility, Mumbai. Experimental angular anisotropies in this reaction were observed to be higher than those calculated using statistical theory, indicating contribution from non-compound nucleus fission in this reaction. (author)

  20. Intermediate mass distribution of the dual resonance pomeron

    International Nuclear Information System (INIS)

    Chiu, C.B.; Matsuda, S.

    1978-01-01

    The intermediate mass distribution of the dual resonance pomeron is determined at the one-loop level and it is shown that the mass distribution obtained is remarkably similar to a suitably defined mass distribution in the dual multiperipheral model. Thus it is suggestive to identify the intermediate states of the dual resonance pomeron with multiperipheral processes. (Auth.)

  1. Influence of primary fragment excitation energy and spin distributions on fission observables

    Science.gov (United States)

    Litaize, Olivier; Thulliez, Loïc; Serot, Olivier; Chebboubi, Abdelaziz; Tamagno, Pierre

    2018-03-01

    Fission observables in the case of 252Cf(sf) are investigated by exploring several models involved in the excitation energy sharing and spin-parity assignment between primary fission fragments. In a first step the parameters used in the FIFRELIN Monte Carlo code "reference route" are presented: two parameters for the mass dependent temperature ratio law and two constant spin cut-off parameters for light and heavy fragment groups respectively. These parameters determine the initial fragment entry zone in excitation energy and spin-parity (E*, Jπ). They are chosen to reproduce the light and heavy average prompt neutron multiplicities. When these target observables are achieved all other fission observables can be predicted. We show here the influence of input parameters on the saw-tooth curve and we discuss the influence of a mass and energy-dependent spin cut-off model on gamma-rays related fission observables. The part of the model involving level densities, neutron transmission coefficients or photon strength functions remains unchanged.

  2. Mass and charge distributions in chlorine-induced nuclear reactions

    International Nuclear Information System (INIS)

    Marchetti, A.A.

    1991-01-01

    Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions 37 Cl on 40 Ca and 209 Bi at E/A = 7.3 MeV, and 35 Cl, on 209 Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corresponding to the 31 Cl on 209 Bi reaction was very poor. This prompted the study and application of a deconvolution technique for peak enhancement. The drifts of the charge and mass centroids for the system 37 Cl on 40 Ca are consistent with a process of mass and charge equilibration mediated by nucleon exchange between the two partners, followed by evaporation. The asymmetric systems show a strong drift towards larger asymmetry, with the production of neutron-rich nuclei. It was concluded that this is indicative of a net transfer of protons from the light to the heavy partner, and a net flow of neutrons in the opposite direction. The variances for all systems increase with energy loss, as it would be expected from a nucleon exchange mechanism; however, the variances for the reaction 37 Cl on 40 Ca are higher than those expected from that mechanism. The coefficients of correlation indicate that the transfer of nucleons between projectile and target is correlated. The results were compared to the predictions of two current models based on a stochastic nucleon exchange mechanism. In general, the comparisons between experimental and predicted variances support this mechanism; however, the need for more realistic driving forces in the model calculations is indicated by the disagreement between predicted and experimental centroids

  3. Coincidence measurements of intermediate mass fragments produced in /sup 32/S-induced reactions on Ag at E/A = 22.5 MeV

    International Nuclear Information System (INIS)

    Fields, D.J.; Lynch, W.G.; Nayak, T.K.

    1986-01-01

    Single- and two-particle inclusive cross sections for the production of light nuclei and intermediate mass fragments, 3< or =Z< or =24, were measured at angles well beyond the grazing angle for /sup 32/S-induced reactions on Ag at 720 MeV. Information about fragment multiplicities and reaction dynamics was extracted from measurements of light particles, intermediate mass fragments, and targetlike residues in coincidence with intermediate mass fragments. Incomplete linear momentum transfer and non-compound-particle emission are important features of collisions producing intermediate mass fragments. About half of the incident kinetic energy in these collisions is converted into internal excitation. The mean multiplicity of intermediate mass fragments is of the order of 1. Particle correlations are strongly enhanced in the plane which contains the intermediate mass fragment and the beam axis

  4. Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

    International Nuclear Information System (INIS)

    Durand, O.; Soulard, L.

    2013-01-01

    Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10 8 atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle

  5. Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2013-11-21

    Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10{sup 8} atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle.

  6. The mass (charge) spectrum of superheavy nuclei fission fragments: the new perspectives for the theory of nucleosynthesis

    International Nuclear Information System (INIS)

    Maslyuk, V.T.

    2012-01-01

    A new approach to the problem of nucleosynthesis based on assumption of a nuclear matter or superheavy nuclei series fragmentation up to atomic nuclei is proposed. It is shown that studies of the mass (charge) fragments yields (MCFY) after nuclear matter disintegration is possible within proposed statistical theory. The data of MCFY calculation for exotic superheavy nuclei multifragmentation with A=300, 900 and 1200 and arbitrary Z values are demonstrated

  7. Fragmentation of atomic clusters: A theoretical study

    International Nuclear Information System (INIS)

    Lopez, M.J.; Jellinek, J.

    1994-01-01

    Collisionless fragmentation of nonrotating model n-atom metal clusters (n=12, 13, and 14) is studied using isoergic molecular-dynamics simulations. Minimum-energy paths for fragmentation are mapped out as functions of the distance between the centers of mass of the fragments. These paths provide information on the fragmentation energies for the different fragmentation channels. Fragmentation patterns (distributions of the fragmentation channel probabilities) and global and channel-specific fragmentation rate constants are computed and analyzed as functions of the internal energy and of the size of the clusters. The trends derived from the dynamics are compared with those obtained using the RRK and TST statistical approaches. The dynamics of the fragmentation process is analyzed in terms of characteristic quantities such as the distance between the centers of mass of the fragments, their relative translational energy, and their interaction energy, all considered as functions of time

  8. Fragmentation study of iridoid glucosides through positive and negative electrospray ionization, collision-induced dissociation and tandem mass spectrometry.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Kerhoas, Lucien; Ducrot, Paul-Henri

    2007-01-01

    Mass spectrometric methodology based on the combined use of positive and negative electrospray ionization, collision-induced dissociation (CID) and tandem mass spectrometry (MS/MS) has been applied to the mass spectral study of a series of six naturally occurring iridoids through in-source fragmentation of the protonated [M+H]+, deprotonated [M--H]- and sodiated [M+Na]+ ions. This led to the unambiguous determination of the molecular masses of the studied compounds and allowed CID spectra of the molecular ions to be obtained. Valuable structural information regarding the nature of both the glycoside and the aglycone moiety was thus obtained. Glycosidic cleavage and ring cleavages of both aglycone and sugar moieties were the major fragmentation pathways observed during CID, where the losses of small molecules, the cinnamoyl and the cinnamate parts were also observed. The formation of the ionized aglycones, sugars and their product ions was thus obtained giving information on their basic skeleton. The protonated, i.e. [M+H]+ and deprotonated [M--H]-, ions were found to fragment mainly by glycosidic cleavages. MS/MS spectra of the [M+Na]+ ions gave complementary information for the structural characterization of the studied compounds. Unlike the dissociation of protonated molecular ions, that of sodiated molecules also provided sodiated sugar fragments where the C0+ fragment corresponding to the glucose ion was obtained as base peak for all the studied compounds. Copyright (c) 2007 John Wiley & Sons, Ltd.

  9. Target-fragment angular distributions for the interaction of 86 MeV/A 12C with 197Au

    International Nuclear Information System (INIS)

    Kraus, R.H. Jr.; Loveland, W.; McGaughey, P.L.; Seaborg, G.T.; Morita, Y.; Hageboe, E.; Haldorsen, I.R.; Sugihara, T.T.

    1985-01-01

    Target-fragment angular distributions were measured using radiochemical techniques for 69 different fragments (44 12 C with 197 Au. The angular distributions in the laboratory system are forward-peaked with some distributions also showing a backward peaking. The shapes of the laboratory system distributions were compared with the predictions of the nuclear firestreak model. The measured angular distributions differed markedly from the predictions of the firestreak model in most cases. This discrepancy could be due, in part, to overestimation of the transferred longitudinal momentum by the firestreak model, the assumption of isotropic angular distributions for fission and particle emission in the moving frame and incorrect assumptions about how the lightest (A 145) fragment distributions were symmetric about 90 0 . (orig.)

  10. Self-organized criticality in fragmenting

    DEFF Research Database (Denmark)

    Oddershede, L.; Dimon, P.; Bohr, J.

    1993-01-01

    The measured mass distributions of fragments from 26 fractured objects of gypsum, soap, stearic paraffin, and potato show evidence of obeying scaling laws; this suggests the possibility of self-organized criticality in fragmenting. The probability of finding a fragment scales inversely to a power...

  11. The potential effects of climate change on amphibian distribution, range fragmentation and turnover in China.

    Science.gov (United States)

    Duan, Ren-Yan; Kong, Xiao-Quan; Huang, Min-Yi; Varela, Sara; Ji, Xiang

    2016-01-01

    Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5) and two time periods (the 2050s and 2070s). Our results show that climate change may cause a major shift in spatial patterns of amphibian diversity. Amphibians in China would lose 20% of their original ranges on average; the distribution outside current ranges would increase by 15%. Suitable habitats for over 90% of species will be located in the north of their current range, for over 95% of species in higher altitudes (from currently 137-4,124 m to 286-4,396 m in the 2050s or 314-4,448 m in the 2070s), and for over 75% of species in the west of their current range. Also, our results predict two different general responses to the climate change: some species contract their ranges while moving westwards, southwards and to higher altitudes, while others expand their ranges. Finally, our analyses indicate that range dynamics and fragmentation are related, which means that the effects of climate change on Chinese amphibians might be two-folded.

  12. The potential effects of climate change on amphibian distribution, range fragmentation and turnover in China

    Directory of Open Access Journals (Sweden)

    Ren-Yan Duan

    2016-07-01

    Full Text Available Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5 and two time periods (the 2050s and 2070s. Our results show that climate change may cause a major shift in spatial patterns of amphibian diversity. Amphibians in China would lose 20% of their original ranges on average; the distribution outside current ranges would increase by 15%. Suitable habitats for over 90% of species will be located in the north of their current range, for over 95% of species in higher altitudes (from currently 137–4,124 m to 286–4,396 m in the 2050s or 314–4,448 m in the 2070s, and for over 75% of species in the west of their current range. Also, our results predict two different general responses to the climate change: some species contract their ranges while moving westwards, southwards and to higher altitudes, while others expand their ranges. Finally, our analyses indicate that range dynamics and fragmentation are related, which means that the effects of climate change on Chinese amphibians might be two-folded.

  13. An optimized approach for simultaneous horizontal data fragmentation and allocation in Distributed Database Systems (DDBSs).

    Science.gov (United States)

    Amer, Ali A; Sewisy, Adel A; Elgendy, Taha M A

    2017-12-01

    With the substantial ever-upgrading advancement in data and information management field, Distributed Database System (DDBS) is still proven to be the most growingly-demanded tool to handle the accompanied constantly-piled volumes of data. However, the efficiency and adequacy of DDBS is profoundly correlated with the reliability and precision of the process in which DDBS is set to be designed. As for DDBS design, thus, several strategies have been developed, in literature, to be used in purpose of promoting DDBS performance. Off these strategies, data fragmentation, data allocation and replication, and sites clustering are the most immensely-used efficacious techniques that otherwise DDBS design and rendering would be prohibitively expensive. On one hand, an accurate well-architected data fragmentation and allocation is bound to incredibly increase data locality and promote the overall DDBS throughputs. On the other hand, finding a practical sites clustering process is set to contribute remarkably in reducing the overall Transmission Costs (TC). Consequently, consolidating all these strategies into one single work is going to undoubtedly satisfy a massive growth in DDBS influence. In this paper, therefore, an optimized heuristic horizontal fragmentation and allocation approach is meticulously developed. All the drawn-above strategies are elegantly combined into a single effective approach so as to an influential solution for DDBS productivity promotion is set to be markedly fulfilled. Most importantly, an internal and external evaluations are extensively illustrated. Obviously, findings of conducted experiments have maximally been recorded to be in favor of DDBS performance betterment.

  14. Energy distribution in selected fragment vibrations in dissociation processes in polyatomic molecules

    International Nuclear Information System (INIS)

    Band, Y.B.; Freed, K.F.

    1977-01-01

    The full quantum theory of dissociation processes in polyatomic molecules is converted to a form enabling the isolation of a selected fragment vibration. This form enables the easy evaluation of the probability distribution for energy partitioning between this vibration and all other degrees of freedom that results from the sudden Franck--Condon rearrangement process. The resultant Franck--Condon factors involve the square of the one-dimensional overlap integral between effective oscillator wavefunctions and the wavefunctions for the selected fragment vibration, a form that resembles the simple golden rule model for polyatomic dissociation and reaction processes. The full quantum theory can, therefore, be viewed as providing both a rigorous justification for certain generic aspects of the simple golden rule model as well as providing a number of important generalizations thereof. Some of these involve dealing with initial bound state vibrational excitation, explicit molecule, fragment and energy dependence of the effective oscillator, and the incorporation of all isotopic dependence. In certain limiting situations the full quantum theory yields simple, readily usable analytic expressions for the frequency and equilibrium position of the effective oscillator. Specific applications are presented for the direct photodissociation of HCN, DCN, and CO 2 where comparisons between the full theory and the simple golden rule are presented. We also discuss the generalizations of the previous theory to enable the incorporation of effects of distortion in the normal modes as a function of the reaction coordinate on the repulsive potential energy surface

  15. Multiplicity distributions and multiplicity correlations in sequential, off-equilibrium fragmentation process

    International Nuclear Information System (INIS)

    Botet, R.

    1996-01-01

    A new kinetic fragmentation model, the Fragmentation - Inactivation -Binary (FIB) model is described where a dissipative process stops randomly the sequential, conservative and off-equilibrium fragmentation process. (K.A.)

  16. Nuclear fragmentation energy and momentum transfer distributions in relativistic heavy-ion collisions

    Science.gov (United States)

    Khandelwal, Govind S.; Khan, Ferdous

    1989-01-01

    An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.

  17. Charge distribution of the 236U* fission fragments with accounting for angular momentum of the compound nuclei

    International Nuclear Information System (INIS)

    Volkov, N.G.; Emel'yanov, V.M.; Krajnov, V.P.

    1979-01-01

    In a statistical fission model calculated are charge distributions of fission fragments (CDFF) of a 236 U* nucleus and their dispersions as the functions of excitation energy and angular momentum (AM) of a compound nucleus as well as the effect of one-particle potential parameter on CDFF. The potential of two-center oscillator was choosen as the one-particle potential. The function of fissioning nucleus level density, which is necessary for calculations in the statistical approach, has been determined from one-particle spectrum. The scheme of calculations is realized with a computer. Presented are the results of calculating the dependence of a neutron gap size on nuclear temperature for various projections of total AM; CDFF for different values of E* excitation energy of AM projection and others. Calculated CDFF and experimental data were compared. Notwithstanding the availability of many parameters and a large volume of numerical calculations the model under consideration permits to describe many common regularities of heavy nucleus CDFF (experimental yields of charges, dispersion dependence on excitation energies and masses of nuclear fragments)

  18. Fragment-Based Screening of a Natural Product Library against 62 Potential Malaria Drug Targets Employing Native Mass Spectrometry

    Science.gov (United States)

    2018-01-01

    Natural products are well known for their biological relevance, high degree of three-dimensionality, and access to areas of largely unexplored chemical space. To shape our understanding of the interaction between natural products and protein targets in the postgenomic era, we have used native mass spectrometry to investigate 62 potential protein targets for malaria using a natural-product-based fragment library. We reveal here 96 low-molecular-weight natural products identified as binding partners of 32 of the putative malarial targets. Seventy-nine (79) fragments have direct growth inhibition on Plasmodium falciparum at concentrations that are promising for the development of fragment hits against these protein targets. This adds a fragment library to the published HTS active libraries in the public domain. PMID:29436819

  19. Combining Fragment-Ion and Neutral-Loss Matching during Mass Spectral Library Searching: A New General Purpose Algorithm Applicable to Illicit Drug Identification.

    Science.gov (United States)

    Moorthy, Arun S; Wallace, William E; Kearsley, Anthony J; Tchekhovskoi, Dmitrii V; Stein, Stephen E

    2017-12-19

    A mass spectral library search algorithm that identifies compounds that differ from library compounds by a single "inert" structural component is described. This algorithm, the Hybrid Similarity Search, generates a similarity score based on matching both fragment ions and neutral losses. It employs the parameter DeltaMass, defined as the mass difference between query and library compounds, to shift neutral loss peaks in the library spectrum to match corresponding neutral loss peaks in the query spectrum. When the spectra being compared differ by a single structural feature, these matching neutral loss peaks should contain that structural feature. This method extends the scope of the library to include spectra of "nearest-neighbor" compounds that differ from library compounds by a single chemical moiety. Additionally, determination of the structural origin of the shifted peaks can aid in the determination of the chemical structure and fragmentation mechanism of the query compound. A variety of examples are presented, including the identification of designer drugs and chemical derivatives not present in the library.

  20. Asymmetric Facial Bone Fragmentation Mirrors Asymmetric Distribution of Cranial Neuromasts in Blind Mexican Cavefish

    Directory of Open Access Journals (Sweden)

    Joshua B. Gross

    2016-10-01

    Full Text Available Craniofacial asymmetry is a convergent trait widely distributed across animals that colonize the extreme cave environment. Although craniofacial asymmetry can be discerned easily, other complex phenotypes (such as sensory organ position and numerical variation are challenging to score and compare. Certain bones of the craniofacial complex demonstrate substantial asymmetry, and co-localize to regions harboring dramatically expanded numbers of mechanosensory neuromasts. To determine if a relationship exists between this expansion and bone fragmentation in cavefish, we developed a quantitative measure of positional symmetry across the left-right axis. We found that three different cave-dwelling populations were significantly more asymmetric compared to surface-dwelling fish. Moreover, cave populations did not differ in the degree of neuromast asymmetry. This work establishes a method for quantifying symmetry of a complex phenotype, and demonstrates that facial bone fragmentation mirrors the asymmetric distribution of neuromasts in different cavefish populations. Further developmental studies will provide a clearer picture of the developmental and cellular changes that accompany this extreme phenotype, and help illuminate the genetic basis for facial asymmetry in vertebrates.

  1. Unpolarised transverse momentum dependent distribution and fragmentation functions from SIDIS multiplicities

    International Nuclear Information System (INIS)

    Anselmino, M.; Boglione, M.; Gonzalez, H. J.O.; Melis, S.; Prokudin, A.

    2014-01-01

    In this study, the unpolarised transverse momentum dependent distribution and fragmentation functions are extracted from HERMES and COMPASS experimental measurements of SIDIS multiplicities for charged hadron production. The data are grouped into independent bins of the kinematical variables, in which the TMD factorisation is expected to hold. A simple factorised functional form of the TMDs is adopted, with a Gaussian dependence on the intrinsic transverse momentum, which turns out to be quite adequate in shape. HERMES data do not need any normalisation correction, while fits of the COMPASS data much improve with a y-dependent overall normalisation factor. A comparison of the extracted TMDs with previous EMC and JLab data confirms the adequacy of the simple gaussian distributions. The possible role of the TMD evolution is briefly considered

  2. Dimensional crossover in fragmentation

    Science.gov (United States)

    Sotolongo-Costa, Oscar; Rodriguez, Arezky H.; Rodgers, G. J.

    2000-11-01

    Experiments in which thick clay plates and glass rods are fractured have revealed different behavior of fragment mass distribution function in the small and large fragment regions. In this paper we explain this behavior using non-extensive Tsallis statistics and show how the crossover between the two regions is caused by the change in the fragments’ dimensionality during the fracture process. We obtain a physical criterion for the position of this crossover and an expression for the change in the power-law exponent between the small and large fragment regions. These predictions are in good agreement with the experiments on thick clay plates.

  3. Emsission of intermediate mass fragments in the p(1.9 GeV)+natNI reaction

    International Nuclear Information System (INIS)

    Bubak, A.

    2004-06-01

    The emission of the intermediate mass fragments (IMFs; 2 ≤ Z ≤ 14) produced in the interaction of 1.9 GeV protons with nickel ( nat Ni) has been a subject of interest of the present study. Energy spectra of isotopically and elementally identified ejectiles have been measured at angles 15 and 120 with the respect to the beam direction. The identification of the emitted IMFs has been performed by means of the Bragg curve spectroscopy and the time-of-flight technique (TOF). The Bragg curve detectors (BCDs) were employed for the charge identification, whereas the TOF method combined with the BCD, for the mass identification. The main task of the present PhD thesis was to built appropriate data acquisition system, to perform the experiment on the internal beam of the COSY accelerator, to propose the methodology of the off-line analysis of the data, to apply it to the event-by-event stored data, and to perform the phenomenological analysis of the obtained data. The results, experimental procedures, and different techniques of the element and isotope identification by means of the BCD + TOF are presented. The determination of the power law parameter τ characterizing the mass and charge distributions of the reaction products is discussed. Various methods of the nuclear matter temperature determination, the comparison between nuclear matter thermometers, and the discussion of the obtained results, shown in the energy-temperature diagram (the so called caloric curve), are presented as well. The results suggest two different mechanisms of the IMFs production: from the equilibrated (IMFs measured at 120 ), and non-equilibrated (IMFs measured at 15 ) state of the nucleus. (orig.)

  4. In vitro and in vivo tumor models for studies of distribution of radiolabelled monoclonal antibodies and fragments

    International Nuclear Information System (INIS)

    Buchegger, F.; Halpern, S.E.; Sutherland, R.M.; Schreyer, M.; Mach, J.P.; Rochester Univ., NY

    1986-01-01

    Colon carcinoma multicellular spheroids were incubated in vitro with radiolabelled MAbs. The more rapid penetration of fragments as compared to intact MAbs was clearly demonstrated. For the study of antibody localization in tumors in vivo, the model of nude mice with ligated kidneys was used. Although very artificial, this model allowed to demonstrate that, without urinary excretion, Fab fragments accumulated more rapidly into the tumor than intact MAbs and disappeared faster from the blood. This difference was less striking for F(ab') 2 fragments. In the liver a decreased accumulation of both types of fragments as compared to intact MAbs was observed. Concerning radio-immunotherapy we think that Fab fragments are not useful because of their too short half-life the circulation and in tumor and because they will probably be too toxic for the kidneys. Intact MAbs and F(ab') 2 fragments have each their advantages. Intact MAbs show highest tumor accumulation in mice without ligated kidney, however, they remain mostly on the periphery of tumor nodules, as shown by autoradiography. F(ab') 2 fragments have been found to penetrate deeper into the tumor and to accumulate less in the liver. It might be therefore an advantage to combine intact MAbs with F(ab') 2 fragments, so that in the tumor two different regions could be attacked whereas in normal tissues toxicity could be distributed to different organs such as to the liver with intact MAbs and to the kidney with F(ab') 2 fragments. (orig.) [de

  5. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  6. Liquid-vapor phase transition, collective flow and entropy determination from future measurements of intermediate mass fragments

    International Nuclear Information System (INIS)

    Coffin, J.P.

    1991-01-01

    Some global variables reflecting the highly collective character of nuclear matter produced in relativistic heavy-ion collisions are briefly reviewed on the basis of presently available experimental results and of Quantum Statistical Model and Quantum Molecular Dynamic Model predictions relative to intermediate mass fragments. Possible future measurements are suggested. (author) 27 refs., 8 figs

  7. Measurement of mass distribution of U-235 fission products in the intermediate neutron region

    International Nuclear Information System (INIS)

    Nakagomi, Yoshihiro; Kobayashi, Shohei; Yamamoto, Shuji; Kanno, Ikuo; Wakabayashi, Hiroaki.

    1982-01-01

    The mass distribution and the momentum distribution of U-235 fission products in the intermediate neutron region were measured by using a combination system of the Yayoi intermediate neutron column and an electron linear accelerator. The double energy measurement method was applied. A fission chamber, which consists of an enriched uranium target and two Si surface barrier detectors, was used for the measurement of the neutrons with energy above 1.3 eV. The linear accelerator was operated at the repetition rate of 100 Hz and the pulse width of 10 ns. The data obtained by the two-dimensional pulse height analysis were analyzed by the Schmitt's method. The preliminary results of the mass distribution and the momentum distribution of fission fragments were obtained. (Kato, T.)

  8. Heavy neutron-deficient radioactive beams: fission studies and fragment distributions

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, K.H.; Benlliure, J.; Heinz, A.; Voss, B. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Boeckstiegel, C.; Grewe, A.; Steinhaeuser, S.; Clerc, H.G.; Jong, M. de; Junghans, A.R.; Mueller, J. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Pfuetzner, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics

    1998-02-01

    The secondary-beam facility of GSI Darmstadt was used to study the fission process of short-lived radioactive nuclei. Relativistic secondary projectiles were produced by fragmentation of a 1 A GeV {sup 238}U primary beam and identified in nuclear charge and mass number. Their production cross sections were determined, and the fission competition in the statistical deexcitation was deduced for long isotopical chains. New results on the enhancement of the nuclear level density in spherical and deformed nuclei due to collective rotational and vibrational excitations were obtained. Using these reaction products as secondary beams, the dipole giant resonance was excited by electromagnetic interactions in a secondary lead target, and fission from excitation energies around 11 MeV was induced. The fission fragments were identified in nuclear charge, and their velocity vectors were determined. Elemental yields and total kinetic energies have been determined for a number of neutron-deficient actinides and preactinides which were not accessible with conventional techniques. The characteristics of multimodal fission of nuclei around {sup 226}Th were systematically investigated and related to the influence of shell effects on the potential energy and on the level density between fission barrier and scission. A systematic view on the large number of elemental yields measured gave rise to a new interpretation of the enhanced production of even elements in nuclear fission and allowed for a new understanding of pair breaking in large-scale collective motion. (orig.)

  9. Fission-fragment angular distributions and total kinetic energies for 235U(n,f) from .18 to 8.83 MeV

    International Nuclear Information System (INIS)

    Meadows, J.W.; Budtz-Joergensen, C.

    1982-01-01

    A gridded ion chamber was used to measure the fission fragment angular distribution and total kinetic energy for the 235 U(n,f) reaction from 0.18 to 8.81 MeV neutron energy. The anisotropies are in generally good agreement with earlier measurements. The average total kinetic energy is approx. 0.2 MeV greater than the thermal value at neutron energies < 2 MeV and shows a sudden decrease of approx. 0.8 MeV between 4 and 5 MeV neutron energy, well below the (n, n'f) threshold. Possible causes of this decrease are a change in the mass distribution or decreased shell effects in the heavy fragment

  10. Multiplicity correlations of intermediate-mass fragments with pions and fast protons in 12C + 197AU

    International Nuclear Information System (INIS)

    Turzo, K.; Begemann-Blaich, M.L.; Auger, G.

    2003-12-01

    Low-energy π + (E π 12 C+ 197 Au collisions at incident energies from 300 to 1800 MeV per nucleon were detected with the Si-Si(Li)-CsI(Tl) calibration telescopes of the INDRA multidetector. The inclusive angular distributions are approximately isotropic, consistent with multiple rescattering in the target spectator. The multiplicity correlations of the low-energy pions and of energetic protons (E p >or ≤ 150 MeV) with intermediate-mass fragments were determined from the measured coincidence data. The deduced correlation functions 1 + R ∼ 1.3 for inclusive event samples reflect the strong correlations evident from the common impact-parameter dependence of the considered multiplicities. For narrow impact-parameter bins (based on charged-particle multiplicity), the correlation functions are close to unity and do not indicate strong additional correlations. Only for pions at high particle multiplicities (central collisions) a weak anticorrelation is observed, probably due to a limited competition between these emissions. Overall, the results are consistent with the equilibrium assumption made in statistical multifragmentation scenarios. Predictions obtained with intranuclear cascade models coupled to the statistical multifragmentation model are in good agreement with the experimental data. (orig.)

  11. Quark fragmentation and trigger side momentum distributions in high-Psub(T) processes

    International Nuclear Information System (INIS)

    Antolin, J.; Azcoiti, V.; Bravo, J.R.; Alonso, J.L.; Cruz, A.; Ringland, G.A.

    1979-11-01

    It has been widely argued that the experimental evidence concerning the momentum accompanying high Psub(T) triggers is a grave problem for models which take the trigger hadron to be a quark fragment. It is claimed that the trigger hadron takes much too large a fraction (zsub(c)) of the jet momentum for the trigger side jet to be a quark. The jet momentum is not directly measured, but deduced from the derivative of the momentum (psub(x)) accompanying the trigger with respect to the trigger transverse momentum - psub(T)sup(t). This argument is shown to be unsafe. Using both an approximate analytic approach to illustrate the physics and subsequently a full numerical computation it is proved that the deduction of the fractional momentum accompanying the trigger, 1/zsub(c) -1, from dpsub(x)/dpsub(T)sup(t) is not correct. Further it is shown that models which do take the trigger to be a quark fragment are essentially in agreement with the data on trigger side momentum distributions. A surprising prediction of the present analysis is that psub(x) should be approximately constant for psub(T)sup(t) >= 6 GeV/c. (author)

  12. Spatial and energy distributions of the fragments resulting from the dissociation of swift molecular ions in solids

    International Nuclear Information System (INIS)

    Heredia-Avalos, Santiago; Garcia-Molina, Rafael; Abril, Isabel

    2002-01-01

    We have simulated the spatial evolution and energy loss of the fragments that result when swift molecular ions dissociate inside solid targets. In our calculations we have considered that these fragments undergo the following interactions: Coulomb repulsion (among like charged particles), stopping and wake forces (due to electronic excitations induced in the target), and nuclear scattering (with the target nuclei). We study the case of silicon targets irradiated with boron molecular or atomic ions; our results show that the main differences in the energy and spatial distributions of molecular fragments or atomic ions appear at shallow regions, and these tend to disappear at deeper depths

  13. arXiv Fragmentation Uncertainties in Hadronic Observables for Top-quark Mass Measurements

    CERN Document Server

    Corcella, Gennaro; Kim, Doojin

    We study the Monte Carlo uncertainties due to modeling of hadronization and showering in the extraction of the top-quark mass from observables that use exclusive hadronic final states in top decays, such as t→anything+J/ψ or t→anything+(B→charged tracks) , where B is a B -hadron. To this end, we investigate the sensitivity of the top-quark mass, determined by means of a few observables already proposed in the literature as well as some new proposals, to the relevant parameters of event generators, such as HERWIG 6 and PYTHIA 8. We find that constraining those parameters at O(1%–10%) is required to avoid a Monte Carlo uncertainty on mt greater than 500 MeV. For the sake of achieving the needed accuracy on such parameters, we examine the sensitivity of the top-quark mass measured from spectral features, such as peaks, endpoints and distributions of EB , mBℓ , and some mT2 -like variables. We find that restricting oneself to regions sufficiently close to the endpoints enables one to substantially decr...

  14. Melt Fragmentation Characteristics of Metal Fuel with Melt Injection Mass during Initiating Phase of SFR Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Hyo; Lee, Min Ho; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Jerng, Dong Wook [Chung-Ang Univ., Seoul (Korea, Republic of)

    2016-05-15

    The PGSFR has adopted the metal fuel for its inherent safety under severe accident conditions. However, this fuel type is not demonstrated clearly yet under the such severe accident conditions. Additional experiments for examining these issues should be performed to support its licensing activities. Under initiating phase of hypothetic core disruptive accident (HCDA) conditions, the molten metal could be better dispersed and fragmented into the coolant channel than in the case of using oxide fuel. This safety strategy provides negative reactivity driven by a good dispersion of melt. If the coolant channel does not sufficient coolability, the severe recriticality would occur within the core region. Thus, it is important to examine the extent of melt fragmentation. The fragmentation behaviors of melt are closely related to a formation of debris shape. Once the debris shape is formed through the fragmentation process, its coolability is determined by the porosity or thermal conductivity of the melt. There were very limited studies for transient irradiation experiments of the metal fuel. These studies were performed by Transient Reactor Test Facility (TREAT) M series tests in U.S. The TREAT M series tests provided basic information of metal fuel performance under transient conditions. The effect of melt injection mass was evaluated in terms of the fragmentation behaviors of melt. These behaviors seemed to be similar between single-pin and multi-pins failure condition. However, the more melt was agglomerated in case of multi-pins failure.

  15. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    International Nuclear Information System (INIS)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M.; Paes Leme, A.F.; Benede, S.; Molina, E.

    2012-01-01

    Full text: The β-Lactoglobulin (β-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on β-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the β-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of β-Lg w/w in distilled water; 25 U enzyme g 1 of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g 1 protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The β-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified βLg -A showed 18.362 Da and the non modified βLg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified β-Lg showed fragments that present high antigenicity (such as Leu 95 - Leu 104 , Asp 95 - Phe 105 , Tyr 42 - Leu 54 , lle 29 - Val 41 ), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr 42 - Leu 54 was still present, however the other fragments that were observed in the non modified β-Lg were not detected by LC-MS/MS, suggesting that structural change occurred in

  16. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Benede, S.; Molina, E. [Universidad Autonoma de Madrid (Spain)

    2012-07-01

    Full text: The {beta}-Lactoglobulin ({beta}-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on {beta}-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the {beta}-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of {beta}-Lg w/w in distilled water; 25 U enzyme g{sup 1} of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g{sup 1} protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The {beta}-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified {beta}Lg -A showed 18.362 Da and the non modified {beta}Lg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified {beta}-Lg showed fragments that present high antigenicity (such as Leu{sub 95} - Leu{sub 104}, Asp{sub 95} - Phe{sub 105}, Tyr{sub 42} - Leu{sub 54}, lle{sub 29} - Val{sub 41}), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr{sub 42} - Leu{sub 54} was still present, however the other fragments that were observed in the non

  17. Regularity and mass conservation for discrete coagulation–fragmentation equations with diffusion

    KAUST Repository

    Cañ izo, J.A.; Desvillettes, L.; Fellner, K.

    2010-01-01

    We present a new a priori estimate for discrete coagulation-fragmentation systems with size-dependent diffusion within a bounded, regular domain confined by homogeneous Neumann boundary conditions. Following from a duality argument, this a priori

  18. Mass and energy distribution of fragments of sup 232 Th nucleus fission by 21-26. 4 MeV. alpha. -particles. Massovye i ehnergeticheskie raspredeleniya oskolkov deleniya yadra sup 232 Th. alpha. -chastitsami s ehnergiyami 21-26,4 MehV

    Energy Technology Data Exchange (ETDEWEB)

    Zaika, N I; Kibkalo, Yu V; Parlag, O A; Sikora, D I; Tokarev, V P; Shityuk, V A [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Yadernykh Issledovanij

    1989-04-01

    Two-parameter measurements of the mass and energy distributions of fission products in the fission of {sup 232}Th by 21.0-26.4 MeV {alpha}-particles (h=1 MeV) are conducted using the correlation method. The obtained results show that in the region under investigation the average total kinetic energies of the fission products E-bar{sub k} have no noticeable variations within the experimental error of {plus minus} 1.5 MeV and the dispersion {sigma}{sup 2}E{sub k} slowly increases. For the E-bar{sub k} mass dependence of heavy fraction the maximum is observed at A=132, that confirms a hypothesis on the influence of the closed-shell effects at the magic numbers of Z=50 and N=82. Assuming the existence of different barrier values for two models of the fission the ratio of symmetric and asymmetric fission yields are analyzed in the statistical model. It is shown that the barrier difference for two modes of fission is 1.3-1.4 MeV, which is in good agreement with the model of two fission modes.

  19. Fragmentation of neck-like structures

    International Nuclear Information System (INIS)

    Montoya, C.; Bowman, D.R.; Peaslee, G.F.; Michigan State Univ., East Lansing, MI

    1994-01-01

    Evidence for intermediate mass fragment emission from neck-like structures joining projectile- and target-like residues has been observed for peripheral 129 Xe+ nat Cu collisions at E/A=50 MeV. These framents are emitted primarily at velocities intermediate between those of the projectile and the target. Relative to the charge distribution for fragments evaporated from the projectile-like residue, the distribution for ''neck'' emission shows an enhanced emission for fragments with 4 f < 8. (orig.)

  20. Mass formula dependence of calculated spallation reaction product distributions

    International Nuclear Information System (INIS)

    Nishida, Takahiko; Nakahara, Yasuaki

    1990-01-01

    A new version of the spallation reaction simulation code NUCLEUS was developed by incorporating Uno and Yamada's mass formula. This version was used to calculate the distribution of products from the spallation of uranium nuclei by high-energy protons. The dependence of the distributions on the mass formula was examined by comparing the results with those from the original version, which is based on Cameron's mass formula and the mass table compiled by Wapstra et al. As regards the fission component of spallation products, the new version reproduces the reaction product data obtained from thin foil experiments much better, especially on the neutron excess side. (orig.) [de

  1. Fragmentation uncertainties in hadronic observables for top-quark mass measurements

    Directory of Open Access Journals (Sweden)

    Gennaro Corcella

    2018-04-01

    Full Text Available We study the Monte Carlo uncertainties due to modeling of hadronization and showering in the extraction of the top-quark mass from observables that use exclusive hadronic final states in top decays, such as t→anything+J/ψ or t→anything+(B→charged tracks, where B is a B-hadron. To this end, we investigate the sensitivity of the top-quark mass, determined by means of a few observables already proposed in the literature as well as some new proposals, to the relevant parameters of event generators, such as HERWIG 6 and PYTHIA 8. We find that constraining those parameters at O(1%–10% is required to avoid a Monte Carlo uncertainty on mt greater than 500 MeV. For the sake of achieving the needed accuracy on such parameters, we examine the sensitivity of the top-quark mass measured from spectral features, such as peaks, endpoints and distributions of EB, mBℓ, and some mT2-like variables. We find that restricting oneself to regions sufficiently close to the endpoints enables one to substantially decrease the dependence on the Monte Carlo parameters, but at the price of inflating significantly the statistical uncertainties. To ameliorate this situation we study how well the data on top-quark production and decay at the LHC can be utilized to constrain the showering and hadronization variables. We find that a global exploration of several calibration observables, sensitive to the Monte Carlo parameters but very mildly to mt, can offer useful constraints on the parameters, as long as such quantities are measured with a 1% precision.

  2. Fragmentation uncertainties in hadronic observables for top-quark mass measurements

    Science.gov (United States)

    Corcella, Gennaro; Franceschini, Roberto; Kim, Doojin

    2018-04-01

    We study the Monte Carlo uncertainties due to modeling of hadronization and showering in the extraction of the top-quark mass from observables that use exclusive hadronic final states in top decays, such as t →anything + J / ψ or t →anything + (B →charged tracks), where B is a B-hadron. To this end, we investigate the sensitivity of the top-quark mass, determined by means of a few observables already proposed in the literature as well as some new proposals, to the relevant parameters of event generators, such as HERWIG 6 and PYTHIA 8. We find that constraining those parameters at O (1%- 10%) is required to avoid a Monte Carlo uncertainty on mt greater than 500 MeV. For the sake of achieving the needed accuracy on such parameters, we examine the sensitivity of the top-quark mass measured from spectral features, such as peaks, endpoints and distributions of EB, mBℓ, and some mT2-like variables. We find that restricting oneself to regions sufficiently close to the endpoints enables one to substantially decrease the dependence on the Monte Carlo parameters, but at the price of inflating significantly the statistical uncertainties. To ameliorate this situation we study how well the data on top-quark production and decay at the LHC can be utilized to constrain the showering and hadronization variables. We find that a global exploration of several calibration observables, sensitive to the Monte Carlo parameters but very mildly to mt, can offer useful constraints on the parameters, as long as such quantities are measured with a 1% precision.

  3. Conserved peptide fragmentation as a benchmarking tool for mass spectrometers and a discriminating feature for targeted proteomics.

    Science.gov (United States)

    Toprak, Umut H; Gillet, Ludovic C; Maiolica, Alessio; Navarro, Pedro; Leitner, Alexander; Aebersold, Ruedi

    2014-08-01

    Quantifying the similarity of spectra is an important task in various areas of spectroscopy, for example, to identify a compound by comparing sample spectra to those of reference standards. In mass spectrometry based discovery proteomics, spectral comparisons are used to infer the amino acid sequence of peptides. In targeted proteomics by selected reaction monitoring (SRM) or SWATH MS, predetermined sets of fragment ion signals integrated over chromatographic time are used to identify target peptides in complex samples. In both cases, confidence in peptide identification is directly related to the quality of spectral matches. In this study, we used sets of simulated spectra of well-controlled dissimilarity to benchmark different spectral comparison measures and to develop a robust scoring scheme that quantifies the similarity of fragment ion spectra. We applied the normalized spectral contrast angle score to quantify the similarity of spectra to objectively assess fragment ion variability of tandem mass spectrometric datasets, to evaluate portability of peptide fragment ion spectra for targeted mass spectrometry across different types of mass spectrometers and to discriminate target assays from decoys in targeted proteomics. Altogether, this study validates the use of the normalized spectral contrast angle as a sensitive spectral similarity measure for targeted proteomics, and more generally provides a methodology to assess the performance of spectral comparisons and to support the rational selection of the most appropriate similarity measure. The algorithms used in this study are made publicly available as an open source toolset with a graphical user interface. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Dynamics of NO2 dissociation. Study by resonance-enhanced multi-photon ionisation of energy distribution and of anisotropies in fragments

    International Nuclear Information System (INIS)

    Mons, Michel

    1988-01-01

    In this research thesis, the author reports the use of laser resonance-enhanced multi-photon ionization and of time-of-flight mass spectrometry for a detailed characterization of fragments produced by a photo-dissociation process. The author more particularly addressed the case of a NO 2 molecule excited at low energies above the dissociation threshold. In the first part, the author discusses issues and problems related to molecular photo-dissociation. In the second part, he presents the developed method and shows that the combined use of both techniques allows a precise characterisation of photo-fragments in terms of internal or translational energies as well as in terms of angle distributions. Finally, the author presents and discusses results obtained in the case of NO 2 [fr

  5. Multiplicity distributions of projectile fragments in interactions of nuclei with emulsion at 4.1-4.5 A GeV/c

    International Nuclear Information System (INIS)

    Fakhraddin, S; Rahim, Magda A

    2008-01-01

    The results of our systematic studies of projectile fragments (PFs) multiplicity distributions in interactions of 4 He, 12 C, 16 O, 22 Ne and 28 Si with emulsion at 4.1-4.5 A GeV/c are presented in this paper. The mean values for the three different multiplicities of PFs at nearly the same energy are given. The dependence of these mean values on the projectile mass number A p , as well as the dependence of the PFs on target groups (H, CNO and AgBr), has been investigated

  6. Multiplicity distributions of projectile fragments in interactions of nuclei with emulsion at 4.1-4.5 A GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Fakhraddin, S; Rahim, Magda A [Physics Department, Faculty of Science, Sana' a University, Republic of Yemen (Yemen)], E-mail: sakinafa1@hotmail.com, E-mail: dr.magda2006@hotmail.com

    2008-07-15

    The results of our systematic studies of projectile fragments (PFs) multiplicity distributions in interactions of {sup 4}He, {sup 12}C, {sup 16}O, {sup 22}Ne and {sup 28}Si with emulsion at 4.1-4.5 A GeV/c are presented in this paper. The mean values for the three different multiplicities of PFs at nearly the same energy are given. The dependence of these mean values on the projectile mass number A{sub p}, as well as the dependence of the PFs on target groups (H, CNO and AgBr), has been investigated.

  7. Differential Fragmentation of Mobility-Selected Glycans via Ultraviolet Photodissociation and Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Morrison, Kelsey A.; Clowers, Brian H.

    2017-06-01

    The alternative dissociation pathways initiated by ultraviolet photodissociation (UVPD) compared with collision-induced dissociation (CID) may provide useful diagnostic fragments for biomolecule identification, including glycans. However, underivatized glycans do not commonly demonstrate strong UV absorbance, resulting in low fragmentation yields for UVPD spectra. In contrast to UVPD experiments that leverage covalent modification of glycans, we detail the capacity of metal adduction to yield comparatively rich UVPD fragmentation patterns and enhance separation factors for an isomeric glycan set in a drift tube ion mobility system. Ion mobility and UVPD-MS spectra for two N-acetyl glycan isomers were examined, each adducted with sodium or cobalt cations, with the latter providing fragment yield gains of an order of magnitude versus sodium adducts. Furthermore, our glycan analysis incorporated front-end ion mobility separation such that the structural glycan isomers could still be identified even as a mixture and not simply composite spectra of isomeric standards. Cobalt adduction proved influential in the glycan separation by yielding an isomer resolution of 0.78 when analyzed simultaneously versus no discernable separation obtained with the sodium adducts. It is the combined enhancement of both isomeric drift time separation and isomer distinction with improved UVPD fragment ion yields that further bolster multivalent metal adduction for advancing glycan IM-MS experiments. [Figure not available: see fulltext.

  8. Fragment profiling of low molecular weight heparins using reversed phase ion pair liquid chromatography-electrospray mass spectrometry.

    Science.gov (United States)

    Xu, Xiaohui; Li, Daoyuan; Chi, Lequan; Du, Xuzhao; Bai, Xue; Chi, Lianli

    2015-04-30

    Low molecular weight heparins (LMWHs) are linear and highly charged carbohydrate polymers prepared by chemical or enzymatic depolymerization of heparin. Compared to unfractionated heparin (UFH), LMWHs are prevalently used as clinical anticoagulant drugs due to their lower side effects and better bioavailability. The work presented herein provides a rapid and powerful fragment mapping method for structural characterization of LMWHs. The chain fragments of two types of LMWHs, enoxaparin and nadroparin, were generated by controlled enzymatic digestion with each of heparinase I (Hep I, Enzyme Commission (EC) # 4.2.2.7), heparinase II (Hep II, no EC # assigned) and heparinase III (Hep III, EC # 4.2.2.8). Reversed phase ion pair high performance liquid chromatography (RPIP-HPLC) coupled with electrospray ion trap time-of-flight mass spectrometry (ESI-IT-TOF-MS) was used to profile the oligosaccharide chains ranging from disaccharides to decasaccharides. A database containing all theoretical structural compositions was established to assist the mass spectra interpretation. The six digests derived by three enzymes from two types of LMWHs exhibited distinguishable fingerprinting patterns. And a total of 94 enoxaparin fragments and 109 nadroparin fragments were detected and identified. Besides the common LMWH oligosaccharides, many components containing characteristic LMWH structures such as saturated L-idopyranosuronic acid, 2,5-anhydro-D-mannitol, 1,6-anhydro-D-aminopyranose, as well as odd number oligosaccharides were also revealed. Quantitative comparison of major components derived from innovator and generic nadroparin products was presented. This approach to profile LMWHs' fragments offers a highly reproducible, high resolution and information-rich tool for evaluating the quality of this category of anticoagulant drugs or comparing structural similarities among samples from various sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Measurement of the angular distribution of fission fragments using a PPAC assembly at CERN n{sub T}OF

    Energy Technology Data Exchange (ETDEWEB)

    Tarrío, D., E-mail: dtarriov@gmail.com [Universidade de Santiago de Compostela (Spain); Leong, L.S.; Audouin, L. [Centre National de la Recherche Scientifique/IN2P3 -Université Paris-Sud - IPN, Orsay (France); Duran, I.; Paradela, C. [Universidade de Santiago de Compostela (Spain); Tassan-Got, L.; Le Naour, C.; Bacri, C.O.; Petitbon, V.; Mottier, J. [Centre National de la Recherche Scientifique/IN2P3 -Université Paris-Sud - IPN, Orsay (France); Caamaño, M. [Universidade de Santiago de Compostela (Spain); Altstadt, S. [Johann-Wolfgang-Goethe Universität, Frankfurt (Germany); Andrzejewski, J. [Uniwersytet Łódzki, Lodz (Poland); Barbagallo, M. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Bécares, V. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); Bečvář, F. [Charles University, Prague (Czech Republic); Belloni, F. [Commissariat à l’Énergie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); Berthoumieux, E. [Commissariat à l’Énergie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Billowes, J. [University of Manchester, Oxford Road, Manchester (United Kingdom); Boccone, V. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); and others

    2014-04-11

    A fission reaction chamber based on Parallel Plate Avalanche Counters (PPACs) was built for measuring angular distributions of fragments emitted in neutron-induced fission of actinides at the neutron beam available at the Neutron Time-Of-Flight (n{sub T}OF) facility at CERN. The detectors and the samples were tilted 45° with respect to the neutron beam direction to cover all the possible values of the emission angle of the fission fragments. The main features of this setup are discussed and results on the fission fragment angular distribution are provided for the {sup 232}Th(n,f) reaction around the fission threshold. The results are compared with the available data in the literature, demonstrating the good capabilities of this setup.

  10. Search for new physics in dijet mass and angular distributions

    Indian Academy of Sciences (India)

    We present a search for physics beyond the Standard Model in proton–proton collisions at a centre-of-mass energy of s = 7 TeV, performed with the ATLAS detector at the Large Hadron Collider (LHC). No evidence for new physics is found in dijet mass and angular distributions and stringent limits are set on a variety of ...

  11. Angular distributions of target fragments from the reactions of 292 MeV - 25.2 GeV 12C with 197Au and 238U

    International Nuclear Information System (INIS)

    Morita, Y.

    1983-01-01

    The angular distributions of the 197 Au target fragments were all forwardly peaked. Extensively forward peaked angular distributions were observed at the non-relativistic projectile energies (292 MeV, 1.0 GeV). No obvious differences were observed in the angular distributions at the different relativistic projectile energies of 3.0 GeV, 12.0 GeV and 25.2 GeV. The characteristic angular distribution pattern from the relativistic projectile energy experiments was also observed in the non-relativistic energy experiments. Maximum degree of forward-peaking in the angular distributions at each projectile energy was observed at the product mass number (A) around 190 from the 292 MeV projectile energy, at A = 180 from 1.0 GeV and at A =175 from 3.0 GeV and 12.0 GeV. In general, two different types of angular distributions were observed in the relativistic projectile energy experiments with the 238 U target. Isotropic angular distributions were observed for the fission product nuclides. The angular distributions of the fission products at the intermediate (292 MeV) energy showed slightly forward peaked angular distributions. Because of the long projectile-target interaction time in the primary nuclear reaction, larger momentum was transferred from the projectile to the target nucleus. Steep forward-peaked angular distributions were also observed with the 238 U target

  12. Occurrence of C-Terminal Residue Exclusion in Peptide Fragmentation by ESI and MALDI Tandem Mass Spectrometry

    Science.gov (United States)

    Dupré, Mathieu; Cantel, Sonia; Martinez, Jean; Enjalbal, Christine

    2012-02-01

    By screening a data set of 392 synthetic peptides MS/MS spectra, we found that a known C-terminal rearrangement was unexpectedly frequently occurring from monoprotonated molecular ions in both ESI and MALDI tandem mass spectrometry upon low and high energy collision activated dissociations with QqTOF and TOF/TOF mass analyzer configuration, respectively. Any residue localized at the C-terminal carboxylic acid end, even a basic one, was lost, provided that a basic amino acid such arginine and to a lesser extent histidine and lysine was present in the sequence leading to a fragment ion, usually depicted as (bn-1 + H2O) ion, corresponding to a shortened non-scrambled peptide chain. Far from being an epiphenomenon, such a residue exclusion from the peptide chain C-terminal extremity gave a fragment ion that was the base peak of the MS/MS spectrum in certain cases. Within the frame of the mobile proton model, the ionizing proton being sequestered onto the basic amino acid side chain, it is known that the charge directed fragmentation mechanism involved the C-terminal carboxylic acid function forming an anhydride intermediate structure. The same mechanism was also demonstrated from cationized peptides. To confirm such assessment, we have prepared some of the peptides that displayed such C-terminal residue exclusion as a C-terminal backbone amide. As expected in this peptide amide series, the production of truncated chains was completely suppressed. Besides, multiply charged molecular ions of all peptides recorded in ESI mass spectrometry did not undergo such fragmentation validating that any mobile ionizing proton will prevent such a competitive C-terminal backbone rearrangement. Among all well-known nondirect sequence fragment ions issued from non specific loss of neutral molecules (mainly H2O and NH3) and multiple backbone amide ruptures (b-type internal ions), the described C-terminal residue exclusion is highly identifiable giving raise to a single fragment ion in

  13. Energy distribution of projectile fragment particles in heavy ion therapeutic beam

    Energy Technology Data Exchange (ETDEWEB)

    Matsufuji, Naruhiro; Tomura, Hiromi; Futami, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)] [and others

    1998-03-01

    Production of fragment particles in a patient`s body is one of important problems for heavy charged particle therapy. It is required to know the yield and the energy spectrum for each fragment element - so called `beam quality` to understand the effect of therapeutic beam precisely. In this study, fragment particles produced by practical therapeutic beam of HIMAC were investigated with using tissue-equivalent material and a detector complex. From the results, fragment particles were well identified by difference of their atomic numbers and the beam quality was derived. Responses of the detectors in this energy region were also researched. (author)

  14. Measurement of Fission Fragment Angular Distributions for 14 N+ 232 Th and 11 B+ 235 U at Near-Barrier Energies

    International Nuclear Information System (INIS)

    Behera, B.R.; Jena, S.; Satapathy, M.; Ison, V.V.; Kailas, S.; Chatterjee, A.; Shrivastava, A.; Mahata, K.; Satpathy, L.; Basu, P.; Roy, S.; Sharan, M.; Chatterjee, M.L; Datta, S.K.

    2000-01-01

    Fission fragment angular distributions of heavy-ion induced fission in actinide nuclei at near-barrier energies show anomalous fragment anisotropies. At above barrier energies entrance channel dependence is a probable cause and explanation in terms of pre-equilibrium fission and the critical mass asymmetry parameter (Businaro-Gallone) has been tried. Target deformation and ground state spin also seem to influence the measured anisotropy. To understand the extent of importance of some or all of these features, we performed a set of experiments where (i) entrance channel dependence (ii) mass asymmetry on the two sides of Businaro-Gallone and (iii) different ground state spins are present. The channels chosen are 14 N+ 232 Th and 11 B+ 235 U. Experiments were done using the Pelletron accelerators at NSC, New Delhi and BARC-TIFR, Bombay. Compound nucleus populated in both cases is 246 Bk. 232 Th has ground state spin zero and 235 U has spin 7/2. Fragment anisotropies have been measured from 10-15 % above barrier to 10 % below barrier at similar excitation energy (around 40 MeV to 58 MeV). The mean square angular momentum is matched at least at one energy. Results indicate that when both excitation energy and angular momentum are matched, there are differences in the measured values of fission anisotropies. This implies entrance channel dependence consistent with the expectation of pre-equilibrium fission model. (authors)

  15. Dynamical scenario of intermediary mass fragments formation in heavy ion collisions

    International Nuclear Information System (INIS)

    Ayik, S.; Belkacem, M.; Gregoire, C.; Stryjewski, J.; Suraud, E.

    1989-01-01

    We briefly remind the possible dynamical scenario of fragments formation in heavy-ion collisions at some tens fo MeV/A. We discuss how present day dynamical models can describe fragment formation. We next turn to the Boltzmann-Langevin formalism which provides a well defined theoretical framework for the understanding of the growing of the dynamical instabilities leading to multifragmentation. We present a first numerical solution of the Boltzmann-Langevin equation and we apply the formalism to the onset of multifragmentation of the 40 Ca + 40 Ca system between 20 and 60 MeV/A beam energy [fr

  16. Practical application of in silico fragmentation based residue screening with ion mobility high-resolution mass spectrometry.

    Science.gov (United States)

    Kaufmann, Anton; Butcher, Patrick; Maden, Kathry; Walker, Stephan; Widmer, Mirjam

    2017-07-15

    A screening concept for residues in complex matrices based on liquid chromatography coupled to ion mobility high-resolution mass spectrometry LC/IMS-HRMS is presented. The comprehensive four-dimensional data (chromatographic retention time, drift time, mass-to-charge and ion abundance) obtained in data-independent acquisition (DIA) mode was used for data mining. An in silico fragmenter utilizing a molecular structure database was used for suspect screening, instead of targeted screening with reference substances. The utilized data-independent acquisition mode relies on the MS E concept; where two constantly alternating HRMS scans (low and high fragmentation energy) are acquired. Peak deconvolution and drift time alignment of ions from the low (precursor ion) and high (product ion) energy scan result in relatively clean product ion spectra. A bond dissociation in silico fragmenter (MassFragment) supplied with mol files of compounds of interest was used to explain the observed product ions of each extracted candidate component (chromatographic peak). Two complex matrices (fish and bovine liver extract) were fortified with 98 veterinary drugs. Out of 98 screened compounds 94 could be detected with the in silico based screening approach. The high correlation among drift time and m/z value of equally charged ions was utilized for an orthogonal filtration (ranking). Such an orthogonal ion mobility based filter removes multiply charged ions (e.g. peptides and proteins from the matrix) as well as noise and artefacts. Most significantly, this filtration dramatically reduces false positive findings but hardly increases false negative findings. The proposed screening approach may offer new possibilities for applications where reference compounds are hardly or not at all commercially available. Such areas may be the analysis of metabolites of drugs, pyrrolizidine alkaloids, marine toxins, derivatives of sildenafil or novel designer drugs (new psychoactive substances

  17. Competitive fragmentation pathways of acetic acid dimer explored by synchrotron VUV photoionization mass spectrometry and electronic structure calculations

    Science.gov (United States)

    Guan, Jiwen; Hu, Yongjun; Zou, Hao; Cao, Lanlan; Liu, Fuyi; Shan, Xiaobin; Sheng, Liusi

    2012-09-01

    In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH3COOH)n.H+, the feature related to the fragment ions (CH3COOH)H+.COO (105 amu) via β-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH3COOH).H+ and (CH3COOH)H+.COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C-C bond cleavage product (CH3COOH)H+.COO. After surmounting the methyl hydrogen-transfer barrier 10.84 ± 0.05 eV, the opening of dissociative channel to produce ions (CH3COOH)+ becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH3COOH).CH3CO+. Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9-15 eV.

  18. Long-term fragmentation effects on the distribution and dynamics of canopy gaps in a tropical montane forest

    Science.gov (United States)

    Nicholas R. Vaughn; Gregory P. Asner; Christian P. Giardina

    2015-01-01

    Fragmentation alters forest canopy structure through various mechanisms, which in turn drive subsequent changes to biogeochemical processes and biological diversity. Using repeated airborne LiDAR (Light Detection and Ranging) mappings, we investigated the size distribution and dynamics of forest canopy gaps across a topical montane forest landscape in Hawaii naturally...

  19. Angular distributions of light projectile fragments in deep inelastic Pb+Em interactions at 160 A GeV

    CERN Document Server

    Adamovich, M I; Alexandrov, Yu A; Andreeva, N P; Badyal, S K; Basova, E E; Bhalla, K B; Bhasin, A; Bhatia, V S; Bradnova, V; Bubnov, V I; Cai, X; Chasnikov, I Yu; Chen, G M; Chernova, L P; Chernyavsky, M M; Dhamija, S; El-Chenawi, K F; Felea, D; Feng, S Q; Gaitinov, A S; Ganssauge, E R; Garpman, S I A; Gerassimov, S G; Gheata, A; Gheata, M; Grote, J; Gulamov, K G; Sen-Gupta, S K; Gupta, V K; Henjes, U; Jakobsson, B; Kanygina, E K; Karabova, M; Kharlamov, S P; Kovalenko, A D; Krasnov, S A; Kumar, V; Larionova, V G; Lepekhin, F G; Levitskaya, O V; Li, Y X; Liu, L S; Lokanathan, S; Lord, J J; Lukicheva, N S; Lu, Y; Luo, S B; Mangotra, L K; Manhas, I; Mittra, I S; Musaeva, A K; Nasyrov, S Z; Navotny, V S; Nystrand, J; Otterlund, I; Peresadko, N G; Qian, W Y; Qin, Y M; Raniwala, R; Rao, N K; Röper, M D; Rusakova, V V; Saidkhanov, N; Salmanova, N A; Seitimbetov, A M; Seliverstov, D M; Simonov, B B; Sethi, R; Singh, B; Skelding, D; Söderström, K; Stenlund, E; Svechnikova, L N; Svensson, T; Tawfik, A M; Tothova, M; Tretyakova, M I; Trofimova, T P; Tuleeva, U I; Vashisht, V; Vokal, S; Vrláková, J; Wang, H Q; Wang, X R; Weng, Z Q; Wilkes, R J; Yang, C B; Yin, Z B; Yu, L Z; Zhang, D H; Zheng, P Y; Zhokhova, S I; Zhou, D C

    1999-01-01

    The nuclear emulsion was exposed at CERN by the lead projectile at 160 A GeV. The angles between any pair of fragments with Z=2-4 have been measured in the emulsion plane for the events which did not contain heavy fragments. The constant characterizing the normal angle ( phi ) distribution of the fragment momentum projection onto the emulsion plane with respect to initial projectile momentum p/sub 0/ is found to be sigma /sub phi /=(0.37+or-0.02) mrad. Corresponding value sigma /sub 0/=(121+or-6) MeV/c of nucleon momentum distribution in the lead nucleus coincides with that expected from Fermi momentum distribution for this nucleus. The peak in the pair-angle distribution of double-charged fragments, /sup 8/Be to 2 alpha , is presented for the region of small angles (<0.1 mrad). The fraction of alpha -particles coming from the decay of the ground state /sup 8/Be is found to be (13+or-2)601130f their whole number. (14 refs).

  20. Transverse Momentum Dependent Parton Distribution/Fragmentation Functions at an Electron-Ion Collider

    International Nuclear Information System (INIS)

    Anselmino, M.; Avakian, H.; Boer, D.; Bradamante, F.; Burkardt, M.; Chen, J.P.; Cisbani, E.; Contalbrigo, M.; Crabb, D.; Dutta, D.; Gamberg, L.; Gao, H.; Hasch, D.; Huang, J.; Huang, M.; Kang, Z.; Keppel, C.; Laskaris, G.; Liang, Z.-T.; Liu, M.X.; Makins, N.; Mckeown, R.D.; Metz, A.; Meziani, Z.-E.; Musch, B.; Peng, J.-C.; Prokudin, A.; Qian, X.; Qiang, Y.; Qiu, J.W.; Rossi, P.; Schweitzer, P.; Soffer, J.; Sulkosky, V.; Wang, Y.; Xiao, B.; Ye, Q.; Ye, Q.-J.; Yuan, F.; Zhan, X.; Zhang, Y.; Zheng, W.; Zhou, J.

    2011-01-01

    We present a summary of a recent workshop held at Duke University on Partonic Transverse Momentum in Hadrons: Quark Spin-Orbit Correlations and Quark-Gluon Interactions. The transverse momentum dependent parton distribution functions (TMDs), parton-to-hadron fragmentation functions, and multi-parton correlation functions, were discussed extensively at the Duke workshop. In this paper, we summarize first the theoretical issues concerning the study of partonic structure of hadrons at a future electron-ion collider (EIC) with emphasis on the TMDs. We then present simulation results on experimental studies of TMDs through measurements of single spin asymmetries (SSA) from semi-inclusive deep-inelastic scattering (SIDIS) processes with an EIC, and discuss the requirement of the detector for SIDIS measurements. The dynamics of parton correlations in the nucleon is further explored via a study of SSA in D ((bar D)) production at large transverse momenta with the aim of accessing the unexplored tri-gluon correlation functions. The workshop participants identified the SSA measurements in SIDIS as a golden program to study TMDs in both the sea and valence quark regions and to study the role of gluons, with the Sivers asymmetry measurements as examples. Such measurements will lead to major advancement in our understanding of TMDs in the valence quark region, and more importantly also allow for the investigation of TMDs in the sea quark region along with a study of their evolution.

  1. Vicinage forces between molecular and atomic fragments dissociated from small hydrogen clusters and their effects on energy distributions

    International Nuclear Information System (INIS)

    Barriga-Carrasco, Manuel D.; Garcia-Molina, Rafael

    2003-01-01

    In this paper we analyze the dynamic evolution of molecular and atomic fragments of small hydrogen clusters interacting with thin solid foils. We compare the vicinage forces, calculated within the dielectric formalism, for H + , H 0 , and H 2 + fragments. Using a molecular dynamics numerical code we determine the energy distribution of the fragments after interacting with the target. This distribution is compared to experimental results for protons coming from the fragmentation of v=2.02 a.u. H 2 + ions impinging on an aluminum foil; a fraction of neutral H 0 is needed to be included in the simulation to get a good agreement with the experimental results. The H 2 + energy spectra for v=5.42 a.u. H 3 + interacting with amorphous carbon is also determined. The asymmetry in the Coulomb peaks appearing in the energy spectra both experimentally and in our calculation is opposite for H 2 + than in H + ; kinematic effects and differences in the electronic stopping are enough to reproduce the difference in the alignment of H 2 + and H + fragments

  2. Gamma-carboxylation and fragmentation of osteocalcin in human serum defined by mass spectrometry

    Science.gov (United States)

    Serum osteocalcin (Oc) concentration is a highly specific measure of bone turnover, but its circulating proteoform(s) have not been well defined. Based on immunological methods, the major forms are thought to be the intact polypeptide and a large N-terminal-mid molecule fragment for which there is n...

  3. High precision mass measurements of thermalized relativistic uranium projectile and fission fragments with a multiple-reflection time-of-flight mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ayet San Andres, Samuel [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Justus Liebig Universitaet, Giessen (Germany); Collaboration: FRS Ion Catcher-Collaboration

    2016-07-01

    At the FRS Ion Catcher at GSI, a relativistic beam of {sup 238}U at 1GeV/u was used to produce fission and projectile fragments on a beryllium target. The ions were separated in-flight at the FRS, thermalized in a cryogenic stopping cell and transferred to a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) where high precision mass measurements were performed. The masses of several fission and projectile fragments were measured (including short-lived nuclei with half-lives down to 18 ms) and the possibility of tailoring an isomerically clean beam for other experiments was demonstrated. With the demonstrated performance of the MR-TOF-MS and the expected production rates of exotic nuclei far from stability at the next-generation facilities such as FAIR, novel mass measurements of nuclei close to the neutron drip line will be possible and key information for understanding the r-process will be available. The results from the last experiment and an outlook of possible future mass measurements close to the neutron drip line at FAIR with the MR-TOF-MS are presented.

  4. IS THE MATRIX REALLY INHOSPITABLE? VOLE RUNWAY DISTRIBUTION IN AN EXPERIMENTALLY FRAGMENTED LANDSCAPE

    Science.gov (United States)

    Habitat fragmentation is a common feature of modern landscapes, with significant impacts on the population densities of and space use by animals. A frequest model system for studying these effects is that of voles (Microtus spp.) and other rodents in experimentally fragmented gr...

  5. Projectile fragmentation of neutron-rich nuclei on light target (momentum distribution and nucleon-removal cross section)

    International Nuclear Information System (INIS)

    Kobayashi, T.; Tanihata, I.; Suzuki, T.

    1992-01-01

    Transverse momentum distributions of the projectile fragments from β-unstable nuclei have been measured with various projectile and target combinations. The momentum correlation of two neutrons in the neutron halo is extracted from the P c t distribution of 9 Li and hat of the neutrons. It is found that the two neutrons are moving in the same direction on average and thus strongly suggests the formation of a di-neutron in 11 Li. (Author)

  6. Affleck-Dine baryogenesis, condensate fragmentation and gravitino dark matter in gauge-mediation with a large messenger mass

    International Nuclear Information System (INIS)

    Doddato, Francesca; McDonald, John

    2011-01-01

    We study the conditions for successful Affleck-Dine baryogenesis and the origin of gravitino dark matter in GMSB models. AD baryogenesis in GMSB models is ruled out by neutron star stability unless Q-balls are unstable and decay before nucleosynthesis. Unstable Q-balls can form if the messenger mass scale is larger than the flat-direction field Φ when the condensate fragments. We provide an example based on AD baryogenesis along a d = 6 flat direction for the case where m 3/2 ≈ 2GeV, as predicted by gravitino dark matter from Q-ball decay. Using a phenomenological GMSB potential which models the Φ dependence of the SUSY breaking terms, we numerically solve for the evolution of Φ and show that the messenger mass can be sufficiently close to the flat-direction field when the condensate fragments. We compute the corresponding reheating temperature and the baryonic charge of the condensate fragments and show that the charge is large enough to produce late-decaying Q-balls which can be the origin of gravitino dark matter

  7. Vertical and horizontal distribution of pollination systems in cerrado fragments of central Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Quintas Martins

    2007-05-01

    Full Text Available In fragments of the cerrado, we determined the frequency of pollination systems and analyzed their spatial distribution. We placed 38 transects, sampling 2,280 individuals and 121 species. As expected in Neotropical regions, bee-pollination was the most frequent pollination system. We found a decrease in the frequency of plants pollinated by beetles towards the fragment interior. Similarly, we found significant variation in relation to height just for the bats; there was an increase in the frequency of plants pollinated by bats towards the higher heights. In general, we found no horizontal and vertical variation in the pollination systems, probably as consequence of the more open physiognomy of the cerrado vegetation.As principais pressões seletivas nas estratégias de polinização originam principalmente do ambiente em que plantas ocorrem, como subdossel, dossel, borda ou interior de um fragmento. Diferentes condições ambientais aumentam as diferenças entre os nichos ecológicos e podem implicar diferenças nas proporções dos sistemas de polinização. Em fragmentos de cerrado, determinamos a freqüência dos sistemas de polinização e analisamos sua distribuição espacial. Lançamos 38 transecções aleatoriamente, amostrando 2.280 indivíduos e 121 espécies. Como esperado para regiões neotropicais, a polinização por abelhas foi o sistema de polinização mais freqüente. Encontramos uma diminuição na freqüência de plantas polinizadas por besouros em direção ao interior do fragmento. De modo similar, encontramos uma variação significativa em relação à altura somente para os morcegos, havendo um aumento na freqüência de plantas em direção a alturas mais altas. Em geral, não encontramos variações horizontais e verticais nos sistemas de polinização, provavelmente, como conseqüência da fisionomia mais aberta de cerrado.

  8. PELE弹丸靶后破片尺寸分布研究%A study on fragmentation distribution of PELE

    Institute of Scientific and Technical Information of China (English)

    樊自建; 冉宪文; 汤文辉; 黄秋生

    2017-01-01

    Target plate rear damage effect is closely related to the fragment's size and quantity which are produced by penetrator with enhanced lateral effect (PELE).In order to study the factors influencing the scale of projectile shell fragments and determine the fragment distribution scale,the expansion process of PELE projectile shell was analyzed,according to the Mott-Grady fragmentation theory.The theoretical analysis method of the distribution range of the fragment scale was given.The correctness of the theoretical analysis was tested by experiments.By theoretical analysis and experimental study,the results show that projectile shell fragment size distribution is mainly affected by material density,crushing energy consumption,critical fracture strain and strain rate.The fragments width and number are greatly influenced by inner core material.With the increasing of density and elastic modulus of the inner core material,the width of front-end fragment decreases the number,the radial velocity becomes large.The shell fragment length is determined by projectile impacting target speed and less affected by the inner core material.%横向效应增强型弹丸(PELE)靶后毁伤效果与穿靶后形成的破片数量及大小密切相关.依据Mott-Grady破碎理论和PELE弹丸壳体膨胀过程假设,提出了弹丸壳体破片尺寸分布范围的理论分析方法,并通过实验回收弹体破片尺寸的统计分析,验证了理论分析方法的合理性.理论与实验研究表明,PELE弹丸壳体破片尺寸分布与壳体材料密度、破碎耗能、临界破碎应变、应变率等因素相关;破片的环向宽度和数量受内芯材料的影响较大,存在随着内芯材料的密度和弹性模量的增加前端破片环向宽度减小,数量增多,径向飞散速度变大的规律;但从实验结果看,外壳破片轴向长度则受内芯材料的影响较小,主要与弹靶碰撞速度相关.

  9. Procedure of non-contacting local mass density and mass density distribution measurements

    International Nuclear Information System (INIS)

    Menzel, M.; Winkler, K.

    1985-01-01

    The invention has been aimed at a procedure of non-contacting local mass density and/or mass density distribution measurements i.e. without the interfering influence of sensors or probes. It can be applied to installations, apparatuses and pipings of chemical engineering, to tank constructions and transportation on extreme temperature and/or pressure conditions and aggressive media influences respectively. The procedure has utilized an ionizing quantum radiation whereby its unknown weakening and scattering is compensated by a suitable combination of scattering and transmission counter rate measurements in such a way that the local mass densities and the mass density distribution respectively are determinable

  10. Analysis of human blood plasma cell-free DNA fragment size distribution using EvaGreen chemistry based droplet digital PCR assays.

    Science.gov (United States)

    Fernando, M Rohan; Jiang, Chao; Krzyzanowski, Gary D; Ryan, Wayne L

    2018-04-12

    Plasma cell-free DNA (cfDNA) fragment size distribution provides important information required for diagnostic assay development. We have developed and optimized droplet digital PCR (ddPCR) assays that quantify short and long DNA fragments. These assays were used to analyze plasma cfDNA fragment size distribution in human blood. Assays were designed to amplify 76,135, 490 and 905 base pair fragments of human β-actin gene. These assays were used for fragment size analysis of plasma cell-free, exosome and apoptotic body DNA obtained from normal and pregnant donors. The relative percentages for 76, 135, 490 and 905 bp fragments from non-pregnant plasma and exosome DNA were 100%, 39%, 18%, 5.6% and 100%, 40%, 18%,3.3%, respectively. The relative percentages for pregnant plasma and exosome DNA were 100%, 34%, 14%, 23%, and 100%, 30%, 12%, 18%, respectively. The relative percentages for non-pregnant plasma pellet (obtained after 2nd centrifugation step) were 100%, 100%, 87% and 83%, respectively. Non-pregnant Plasma cell-free and exosome DNA share a unique fragment distribution pattern which is different from pregnant donor plasma and exosome DNA fragment distribution indicating the effect of physiological status on cfDNA fragment size distribution. Fragment distribution pattern for plasma pellet that includes apoptotic bodies and nuclear DNA was greatly different from plasma cell-free and exosome DNA. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rader, D.J.; Benson, D.A.

    1995-05-01

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 {mu}m and a geometric standard deviation, {sigma}{sub g} of about 2; the CMD was found to increase and {sigma}{sub g} decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 {mu}m and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented.

  12. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    International Nuclear Information System (INIS)

    Rader, D.J.; Benson, D.A.

    1995-05-01

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 μm and a geometric standard deviation, σ g of about 2; the CMD was found to increase and σ g decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 μm and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented

  13. Prompt neutron emission from fragments in spontaneous fission of {sup 244,248}Cm and {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyev, A. S.; Shcherbakov, O. A. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300 (Russian Federation); Dushin, V. N.; Jakovlev, V. A.; Kalinin, V. A.; Petrov, B. F. [V.G. Khlopin Radium Institute, St. Petersburg, 194021 (Russian Federation); Hambsch, F.J [EC-JRC-Institute for Reference Materials and Measurements Retieseweg 111, B-2440 Geel (Belgium); Laptev, A. B. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300 (Russian Federation); Japan Nuclear Cycle Development Institute, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan)

    2005-07-01

    Neutrons emitted in fission were measured separately for each complementary fragment in correlation with fission fragment energies. Two high efficiency Gd-loaded liquid scintillator tanks were used for neutron registration. Fission fragment energies were measured using a twin Frisch gridded ionization chamber with a pin-hole collimator. The neutron multiplicity distributions were obtained for each value of the fission fragment mass and energy and corrected for neutron registration efficiency, background and pile-up. The dependencies of these distributions on fragment mass and energy for different energy and mass bins, as well as the mass and energy distribution of the fission fragments are presented and discussed. (authors)

  14. First Isochronous Time-of-Flight Mass Measurements of Short-Lived Projectile Fragments in the ESR

    International Nuclear Information System (INIS)

    Stadlmann, J.; Geissel, H.; Hausmann, M.; Nolden, F.; Radon, T.; Schatz, H.; Scheidenberger, C.; Attallah, F.; Beckert, K.; Bosch, F.; Falch, M.; Franczak, B.; Franzke, B.; Kerscher, Th.; Klepper, O.; Kluge, H.J.; Kozhuharov, C.; Loebner, K.E.G.; Muenzenberg, G.; Novikov, Yu.N.; Steck, M.; Sun, Z.; Suemmerer, K.; Weick, H.; Wollnik, H.

    2000-01-01

    A new method for precise mass measurements of short-lived hot nuclei is presented. These nuclei were produced via projectile fragmentation, separated with the FRS and injected into the storage ring ESR being operated in the isochronous mode. The revolution time of the ions is measured with a time-of-flight detector sensitive to single particles. This new method allows access to exotic nuclei with half-lives in the microsecond region. First results from this novel method obtained with measurements on neutron-deficient fragments of a chromium primary beam with half-lives down to 50 ms are reported. A precision of deltam/m ≤ 5 · 10 -6 has been achieved

  15. THE MASS DISTRIBUTION OF COMPANIONS TO LOW-MASS WHITE DWARFS

    International Nuclear Information System (INIS)

    Andrews, Jeff J.; Price-Whelan, Adrian M.; Agüeros, Marcel A.

    2014-01-01

    Measuring the masses of companions to single-line spectroscopic binary stars is (in general) not possible because of the unknown orbital plane inclination. Even when the mass of the visible star can be measured, only a lower limit can be placed on the mass of the unseen companion. However, since these inclination angles should be isotropically distributed, for a large enough, unbiased sample, the companion mass distribution can be deconvolved from the distribution of observables. In this work, we construct a hierarchical probabilistic model to infer properties of unseen companion stars given observations of the orbital period and projected radial velocity of the primary star. We apply this model to three mock samples of low-mass white dwarfs (LMWDs; M ≲ 0.45 M ☉ ) and a sample of post-common-envelope binaries. We use a mixture of two Gaussians to model the WD and neutron star (NS) companion mass distributions. Our model successfully recovers the initial parameters of these test data sets. We then apply our model to 55 WDs in the extremely low-mass (ELM) WD Survey. Our maximum a posteriori model for the WD companion population has a mean mass μ WD = 0.74 M ☉ , with a standard deviation σ WD = 0.24 M ☉ . Our model constrains the NS companion fraction f NS to be <16% at 68% confidence. We make samples from the posterior distribution publicly available so that future observational efforts may compute the NS probability for newly discovered LMWDs

  16. A polymer, random walk model for the size-distribution of large DNA fragments after high linear energy transfer radiation

    Science.gov (United States)

    Ponomarev, A. L.; Brenner, D.; Hlatky, L. R.; Sachs, R. K.

    2000-01-01

    DNA double-strand breaks (DSBs) produced by densely ionizing radiation are not located randomly in the genome: recent data indicate DSB clustering along chromosomes. Stochastic DSB clustering at large scales, from > 100 Mbp down to simulations and analytic equations. A random-walk, coarse-grained polymer model for chromatin is combined with a simple track structure model in Monte Carlo software called DNAbreak and is applied to data on alpha-particle irradiation of V-79 cells. The chromatin model neglects molecular details but systematically incorporates an increase in average spatial separation between two DNA loci as the number of base-pairs between the loci increases. Fragment-size distributions obtained using DNAbreak match data on large fragments about as well as distributions previously obtained with a less mechanistic approach. Dose-response relations, linear at small doses of high linear energy transfer (LET) radiation, are obtained. They are found to be non-linear when the dose becomes so large that there is a significant probability of overlapping or close juxtaposition, along one chromosome, for different DSB clusters from different tracks. The non-linearity is more evident for large fragments than for small. The DNAbreak results furnish an example of the RLC (randomly located clusters) analytic formalism, which generalizes the broken-stick fragment-size distribution of the random-breakage model that is often applied to low-LET data.

  17. Quantifying the linear and nonlinear relations between the urban form fragmentation and the carbon emission distribution

    Science.gov (United States)

    Zuo, S.; Dai, S.; Ren, Y.; Yu, Z.

    2017-12-01

    Scientifically revealing the spatial heterogeneity and the relationship between the fragmentation of urban landscape and the direct carbon emissions are of great significance to land management and urban planning. In fact, the linear and nonlinear effects among the various factors resulted in the carbon emission spatial map. However, there is lack of the studies on the direct and indirect relations between the carbon emission and the city functional spatial form changes, which could not be reflected by the land use change. The linear strength and direction of the single factor could be calculated through the correlation and Geographically Weighted Regression (GWR) analysis, the nonlinear power of one factor and the interaction power of each two factors could be quantified by the Geodetector analysis. Therefore, we compared the landscape fragmentation metrics of the urban land cover and functional district patches to characterize the landscape form and then revealed the relations between the landscape fragmentation level and the direct the carbon emissions based on the three methods. The results showed that fragmentation decreased and the fragmented patches clustered at the coarser resolution. The direct CO2 emission density and the population density increased when the fragmentation level aggregated. The correlation analysis indicated the weak linear relation between them. The spatial variation of GWR output indicated the fragmentation indicator (MESH) had the positive influence on the carbon emission located in the relatively high emission region, and the negative effects regions accounted for the small part of the area. The Geodetector which explores the nonlinear relation identified the DIVISION and MESH as the most powerful direct factor for the land cover patches, NP and PD for the functional district patches, and the interactions between fragmentation indicator (MESH) and urban sprawl metrics (PUA and DIS) had the greatly increased explanation powers on the

  18. THE DYNAMICAL EVOLUTION OF LOW-MASS HYDROGEN-BURNING STARS, BROWN DWARFS, AND PLANETARY-MASS OBJECTS FORMED THROUGH DISK FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yun; Kouwenhoven, M. B. N. [Department of Astronomy, School of Physics, Peking University, Yiheyuan Lu 5, Haidian Qu, Beijing 100871 (China); Stamatellos, D. [Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire, Preston, PR1 2HE (United Kingdom); Goodwin, S. P., E-mail: yunli@pku.edu.cn [Department of Physics and Astronomy, The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2015-06-01

    Theory and simulations suggest that it is possible to form low-mass hydrogen-burning stars, brown dwarfs (BDs), and planetary-mass objects (PMOs) via disk fragmentation. As disk fragmentation results in the formation of several bodies at comparable distances to the host star, their orbits are generally unstable. Here, we study the dynamical evolution of these objects. We set up the initial conditions based on the outcomes of the smoothed-particle hydrodynamics simulations of Stamatellos and Whitworth, and for comparison we also study the evolution of systems resulting from lower-mass fragmenting disks. We refer to these two sets of simulations as set 1 and set 2, respectively. At 10 Myr, approximately half of the host stars have one companion left, and approximately 22% (set 1) to 9.8% (set 2) of the host stars are single. Systems with multiple secondaries in relatively stable configurations are common (about 30% and 44%, respectively). The majority of the companions are ejected within 1 Myr with velocities mostly below 5 km s{sup −1}, with some runaway escapers with velocities over 30 km s{sup −1}. Roughly 6% (set 1) and 2% (set 2) of the companions pair up into very low-mass binary systems, resulting in respective binary fractions of 3.2% and 1.2%. The majority of these pairs escape as very low-mass binaries, while others remain bound to the host star in hierarchical configurations (often with retrograde inner orbits). Physical collisions with the host star (0.43 and 0.18 events per host star for set 1 and set 2, respectively) and between companions (0.08 and 0.04 events per host star for set 1 and set 2, respectively) are relatively common and their frequency increases with increasing disk mass. Our study predicts observable properties of very low-mass binaries, low-mass hierarchical systems, the BD desert, and free-floating BDs and PMOs in and near young stellar groupings, which can be used to distinguish between different formation scenarios of very low-mass

  19. Distinguishing Aspartic and Isoaspartic Acids in Peptides by Several Mass Spectrometric Fragmentation Methods

    Science.gov (United States)

    DeGraan-Weber, Nick; Zhang, Jun; Reilly, James P.

    2016-12-01

    Six ion fragmentation techniques that can distinguish aspartic acid from its isomer, isoaspartic acid, were compared. MALDI post-source decay (PSD), MALDI 157 nm photodissociation, tris(2,4,6-trimethoxyphenyl)phosphonium bromide (TMPP) charge tagging in PSD and photodissociation, ESI collision-induced dissociation (CID), electron transfer dissociation (ETD), and free-radical initiated peptide sequencing (FRIPS) with CID were applied to peptides containing either aspartic or isoaspartic acid. Diagnostic ions, such as the y-46 and b+H2O, are present in PSD, photodissociation, and charge tagging. c•+57 and z-57 ions are observed in ETD and FRIPS experiments. For some molecules, aspartic and isoaspartic acid yield ion fragments with significantly different intensities. ETD and charge tagging appear to be most effective at distinguishing these residues.

  20. Fragment ion and electron emission from C sub 6 sub 0 by fast heavy ion impact

    CERN Document Server

    Mizuno, T; Itoh, A; Tsuchida, H; Nakai, Y

    2003-01-01

    Correlation between electron emission and fragmentation of C sub 6 sub 0 was studied using 847keV Si sup + ions. Mass distribution of fragment ions, number distribution of secondary electrons, and final charge distribution of outgoing projectiles were successfully measured by means of a triple coincidence time-of-flight method. Strong correlation was observed for electron emission and fragmentation.

  1. Production cross sections and momentum distributions of the projectile fragments of a 500 MeV/u 86Kr beam

    International Nuclear Information System (INIS)

    Weber, M.

    1993-07-01

    The projectile fragmentation of a 500 MeV/u 86 Kr beam in a beryllium, copper, respectively tantalum target was studied at the projectile-fragment separator of the GSI. The new neutron-rich isotopes 58 Ti, 61 V, 63 Cr, 66 Mn, 69 Fe, and 71 Co could be uniquely identified, furthermore a hint on the existence of 64 Cr, 72 Co, and 75 Ni resulted. The experimental production cross sections, which were determined for a large A and Z range, were compared with the predictions of three different models. The studies presented in the present thesis allow an extrapolation of the production cross section for the double-magic nucleus 78 Ni of only 0.6 pb. With increasing nuclear-charge number of the target material a larger production cross section for light fragments was observed. From these data it can be concluded that projectile-like fragments arise in peripheral and light fragments in central reactions. Furthermore production cross sections and parallel momentum distributions of the rubidium isotopes and the 86 Br were measured. To the experimentally observed charge-exchange products two possible processes can be assigned, namely the quasi-free nucleon-nucleon collision respectively the excitation of a Δresonance. (HSI)

  2. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly...

  3. Distribution of mass in the planetary system and solar nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Weidenschilling, S J [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism

    1977-09-01

    A model 'solar nebula' is constructed by adding the solar complement of light elements to each planet, using recent models of planetary compositions. Uncertainties in this approach are estimated. The computed surface density varies approximately as rsup(-3/2). Mercury, Mars and the asteroid belt are anomalously low in mass, but processes exist which would preferentially remove matter from these regions. Planetary masses and compositions are generally consistent with a monotonic density distribution in the primordial solar nebula.

  4. Mass distribution in 20Ne+232Th reaction

    International Nuclear Information System (INIS)

    Sodaye, Suparna; Tripathi, R.; Sudarshan, K.

    2011-01-01

    Mass distribution was measured in 20 Ne+ 232 Th reaction at E lab =145 MeV using recoil catcher technique followed by off-line gamma-ray spectrometry. Significant contribution from transfer fission was observed in the yield of comparatively neutron rich fission products. The variance of mass distribution for complete fusion fission, obtained by excluding neutron rich fission products, was observed to be consistent with the values reported in literature for similar reaction systems which showed a deviation from the systematics obtained using random neck rupture and liquid drop model. (author)

  5. Sideward peak of intermediate mass fragments in high energy proton induced reactions

    International Nuclear Information System (INIS)

    Ohnishi, A.; Hirata, Y.; Otuka, N.; Nara, Y.; Kido, T.; Maruyama, T.; Takada, H.; Chiba, S.

    2002-01-01

    We study the sideward enhanced IMF emission mechanism by using a combined framework of a transport model (JAM/MF) and a newly developed Non-Equilibrium Percolation (NEP) model. We find that the sideward enhancement may emerge if the fragmentation takes place within a short time scale around 20 fm/c. Within this short time period, the un-heated part of the residual nucleus is kept to have doughnut shape, then the Coulomb repulsion from this shape strengthens the sideward emission of IMFs. (author)

  6. Competitive fragmentation pathways of acetic acid dimer explored by synchrotron VUV photoionization mass spectrometry and electronic structure calculations.

    Science.gov (United States)

    Guan, Jiwen; Hu, Yongjun; Zou, Hao; Cao, Lanlan; Liu, Fuyi; Shan, Xiaobin; Sheng, Liusi

    2012-09-28

    In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH(3)COOH)(n)·H(+), the feature related to the fragment ions (CH(3)COOH)H(+)·COO (105 amu) via β-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH(3)COOH)·H(+) and (CH(3)COOH)H(+)·COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C-C bond cleavage product (CH(3)COOH)H(+)·COO. After surmounting the methyl hydrogen-transfer barrier 10.84 ± 0.05 eV, the opening of dissociative channel to produce ions (CH(3)COOH)(+) becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH(3)COOH)·CH(3)CO(+). Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9-15 eV.

  7. Low Mass MS/MS Fragments of Protonated Amino Acids Used for Distinction of Their 13C- Isotopomers in Metabolic Studies

    Science.gov (United States)

    Ma, Xin; Dagan, Shai; Somogyi, Árpád; Wysocki, Vicki H.; Scaraffia, Patricia Y.

    2013-04-01

    Glu, Gln, Pro, and Ala are the main amino acids involved in ammonia detoxification in mosquitoes. In order to develop a tandem mass spectrometry method (MS2) to monitor each carbon of the above isotopically-labeled 13C-amino acids for metabolic studies, the compositions and origins of atoms in fragments of the protonated amino acid should be first elucidated. Thus, various electrospray (ESI)-based MS2 tools were employed to study the fragmentation of these unlabeled and isotopically-labeled amino acids and better understand their dissociation pathways. A broad range of fragments, including previously-undescribed low m/z fragments was revealed. The formulae of the fragments (from m/z 130 down to m/z 27) were confirmed by their accurate masses. The structures and conformations of the larger fragments of Glu were also explored by ion mobility mass spectrometry (IM-MS) and gas-phase hydrogen/deuterium exchange (HDX) experiments. It was found that some low m/z fragments ( m/z 27-30) are common to Glu, Gln, Pro, and Ala. The origins of carbons in these small fragments are discussed and additional collision induced dissociation (CID) MS2 fragmentation pathways are proposed for them. It was also found that small fragments (≤ m/z 84) of protonated, methylated Glu, and methylated Gln are the same as those of the underivatized Glu and Gln. Taken together, the new approach of utilizing low m/z fragments can be applied to distinguish, identify, and quantify 13C-amino acids labeled at various positions, either in the backbone or side chain.

  8. Mass distribution studies in 28Si + 232Th

    International Nuclear Information System (INIS)

    Sodaye, Suparna; Tripathi, R.; Sudarshan, K.; Pujari, P.K.

    2014-01-01

    Mass distribution is one of the important observables to understand the fusion-fission potential energy landscape. In the fission involving composite systems with Z ∼ 100, the fission barrier is lower and the saddle point is compact. Thus, apart from transfer induced fission,various non compound nucleus (NCN) fission processes like quasi-fission, pre-equilibrium fission and fast fission compete with the complete fusion fission (CFF). This would be further affected by the entrance channel parameters like choice of the target-projectile combination (mass asymmetry) and the projectile energy. Charge and mass distribution studies in such system would provide information about various fission processes such as complete fusion fission, non-compound nucleus fission and transfer induced fission, which would help in understanding the fusion-fission process in heavy ion collisions forming composite system in the heavy and trans-actinide region. In view of this, a systematic study of the charge and mass distribution in 28 Si+ 232 Th reaction was planned at beam energy close to and above the entrance channel Coulomb barrier. The experiments were carried out at the TIFR-LINAC booster facility. Self supporting foils of 232 Th were bombarded with 180 and 160 MeV 28 Si beam in a stack foil arrangement. The recoiling fission products were assayed radiochemically by off-line gamma-ray spectrometry. Results of charge distribution studies at E lab =180 MeV have been reported earlier. In the poster, the data on charge and mass distribution distribution will be presented.The results of the present studies will be compared with those from the reactions involving lighter and heavier composite systems

  9. The extended sum-rule model view of light and intermediate mass fragment emission in nuclear reactions at intermediate energies

    International Nuclear Information System (INIS)

    Brancus, I.M.; Rebel, H.; Wentz, J.; Corcalciuc, V.

    1989-11-01

    The original sum-rule model worked out by Wilczynski et al. and successfully used for a global description of complete and incomplete fusion reactions has been extended by a term accounting for dissipative processes of the dinuclear system on its way to fusion. When applying to light and heavy ion collisions with various targets at energies in the transitional region, the new term proves to be rather essential for reproducing the element distributions of the fragments emitted from rather asymmetric systems. (orig.) [de

  10. A model for projectile fragmentation

    International Nuclear Information System (INIS)

    Chaudhuri, G; Mallik, S; Gupta, S Das

    2013-01-01

    A model for projectile fragmentation is developed whose origin can be traced back to the Bevalac era. The model positions itself between the phenomenological EPAX parametrization and transport models like 'Heavy Ion Phase Space Exploration' (HIPSE) model and antisymmetrised molecular dynamics (AMD) model. A very simple impact parameter dependence of input temperature is incorporated in the model which helps to analyze the more peripheral collisions. The model is applied to calculate the charge, isotopic distributions, average number of intermediate mass fragments and the average size of largest cluster at different Z bound of different projectile fragmentation reactions at different energies.

  11. A new statistical scission-point model fed with microscopic ingredients to predict fission fragments distributions; Developpement d'un nouveau modele de point de scission base sur des ingredients microscopiques

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, S

    2006-07-01

    Nucleus fission process is a very complex phenomenon and, even nowadays, no realistic models describing the overall process are available. The work presented here deals with a theoretical description of fission fragments distributions in mass, charge, energy and deformation. We have reconsidered and updated the B.D. Wilking Scission Point model. Our purpose was to test if this statistic model applied at the scission point and by introducing new results of modern microscopic calculations allows to describe quantitatively the fission fragments distributions. We calculate the surface energy available at the scission point as a function of the fragments deformations. This surface is obtained from a Hartree Fock Bogoliubov microscopic calculation which guarantee a realistic description of the potential dependence on the deformation for each fragment. The statistic balance is described by the level densities of the fragment. We have tried to avoid as much as possible the input of empirical parameters in the model. Our only parameter, the distance between each fragment at the scission point, is discussed by comparison with scission configuration obtained from full dynamical microscopic calculations. Also, the comparison between our results and experimental data is very satisfying and allow us to discuss the success and limitations of our approach. We finally proposed ideas to improve the model, in particular by applying dynamical corrections. (author)

  12. Statistical analysis of fragmentation patterns of electron ionization mass spectra of enolized-trimethylsilylated anabolic androgenic steroids

    Science.gov (United States)

    Fragkaki, A. G.; Angelis, Y. S.; Tsantili-Kakoulidou, A.; Koupparis, M.; Georgakopoulos, C.

    2009-08-01

    Anabolic androgenic steroids (AAS) are included in the List of prohibited substances of the World Anti-Doping Agency (WADA) as substances abused to enhance athletic performance. Gas chromatography coupled to mass spectrometry (GC-MS) plays an important role in doping control analyses identifying AAS as their enolized-trimethylsilyl (TMS)-derivatives using the electron ionization (EI) mode. This paper explores the suitability of complementary GC-MS mass spectra and statistical analysis (principal component analysis, PCA and partial least squares-discriminant analysis, PLS-DA) to differentiate AAS as a function of their structural and conformational features expressed by their fragment ions. The results obtained showed that the application of PCA yielded a classification among the AAS molecules which became more apparent after applying PLS-DA to the dataset. The application of PLS-DA yielded a clear separation among the AAS molecules which were, thus, classified as: 1-ene-3-keto, 3-hydroxyl with saturated A-ring, 1-ene-3-hydroxyl, 4-ene-3-keto, 1,4-diene-3-keto and 3-keto with saturated A-ring anabolic steroids. The study of this paper also presents structurally diagnostic fragment ions and dissociation routes providing evidence for the presence of unknown AAS or chemically modified molecules known as designer steroids.

  13. FRAGMENTATION STUDIES OF D6,7-ANHIDROERITROMISIN-A BY LIQUID CHROMATOGRAPHY-MASS SPECTROSCOPY (LC-MS

    Directory of Open Access Journals (Sweden)

    Khairan Khairan

    2010-06-01

    Full Text Available Semisynthesis of D6,7-Anhydroerythromycin-A was done by biomodification technique by addition of 0.2% INH into a culture fermentation of Saccharopolyspora erythraea ATCC 11635 in medium Hutchinson. The aim of this research is to studies of fragmentation pattern from new matabolite of D6,7-Anhydroerythromycin-A by Liquid Chromatography-Mass Spectroscopy (LC-MS and the ionization of mass spectroscopy is use by ESI (Electrospray Ionization pattern. The FT-IR spectrometric analyzes showed a stretching vibration of C=C conjugated group at wave number 1602.7 cm-1. This C=C conjugated vibration indicated the existence of double bond between C6 and C7 (D6,7, this confirmed that isolate contained D6,7-Anhydroerythromycin-A (the possibility of D6,7 was positive. For complementation, a LC-MS (Liquid Chromatography-Mass Spectroscopy analyzes using ESI-MS (Electrospray Ionization-Mass Spectroscopy ionization pattern was conducted to the isolate which resulted Quassimolecular ions [M+H]+ of D7,8- and D6,7-Anhydroerythromycin-A. LC-MS spectrogram of the isolate, which gave two peaks of m/z 732.2460 and m/z 716.2522, confirmed that the m/z 732.2460 possibly was D7,8-Anhydroerythromycin-A, while the m/z 716.2502 and m/z 715.2522 possibly were D6,7-Anhydroerythromycin-A.   Keywords: isoniazid, enoyl reduction, D6,7-Anhidroeritromisin-A, fragmentation, LC-MS.

  14. A rationale for continuing mass antibiotic distributions for trachoma

    Directory of Open Access Journals (Sweden)

    House Jenafir

    2007-08-01

    Full Text Available Abstract Background The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. Methods We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Results Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Conclusion Local

  15. A rationale for continuing mass antibiotic distributions for trachoma.

    Science.gov (United States)

    Ray, Kathryn J; Porco, Travis C; Hong, Kevin C; Lee, David C; Alemayehu, Wondu; Melese, Muluken; Lakew, Takele; Yi, Elizabeth; House, Jenafir; Chidambaram, Jaya D; Whitcher, John P; Gaynor, Bruce D; Lietman, Thomas M

    2007-08-07

    The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Local elimination from a community is theoretically possible, even in the

  16. Goodness of isospin in neutron rich systems from the fission fragment distribution

    Science.gov (United States)

    Garg, Swati; Jain, Ashok Kumar

    2017-09-01

    We present the results of our calculations for the relative yields of neutron-rich fission fragments emitted in 208Pb (18O, fission) reaction by using the concept of the conservation of isospin and compare with the experimental data. We take into account a range of isospin values allowed by the isospin algebra and assume that the fission fragments are formed in isobaric analog states. We also take into account the neutron multiplicity data for various neutron-emission channels in each partition, and use them to obtain the weight factors in calculating the yields. We then calculate the relative yields of the fission fragments. Our calculated results are able to reproduce the experimental trends reasonably well. This is the first direct evidence of the isospin conservation in neutron-rich systems and may prove a very useful tool in their studies.

  17. A reconsideration of fission fragment angular distributions from nuclei of high spin

    International Nuclear Information System (INIS)

    Vaz, L.C.; Alexander, J.M.

    1983-01-01

    It has often been stated that fission fragment angular anisotropy, as predicted by equilibrium statistical theory, should disappear with increasing spin of the composite nucleus. However, several recent experimental studies reveal strong anisotropies for fission fragments from high-spin nuclear systems. We discuss this apparent discrepancy and its relationship to the rigid-rotor approximation used in the standard theory. A systematic comparison is given for fission fragment anisotropies from many experiments via the empirical parameters K 0 2 and Ssub(eff). These systematics indicate a strong regularity, provided one allows for the perturbing effects of fission after transfer reactions. Many of the observed anisotropies exceed the predictions of the standard theory, but, as these predictions are based on a rigid rotor model, this does not seem particularly noteworthy. (orig.)

  18. The Mass-Ratio Distribution of Visual Binary Stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1990-01-01

    The selection effects that govern the observations of Visual Binary Stars are in- vestigated, in order to obtain a realistic statistical distribution of the mass-ratio q = Msec=Mprim. To this end a numerical simulation programme has been developed, which `generates' binary stars and `looks' at

  19. Storage ion trap of an 'In-Flight Capture' type for precise mass measurement of radioactive nuclear reaction products and fission fragments

    International Nuclear Information System (INIS)

    Tarantin, N.I.

    2001-01-01

    Data on nuclear masses provide a basis for creating and testing various nuclear models. A tandem system of FLNR comprised of the U-400M cyclotron, the COMBAS magnetic separator and the mass-spectrometric ion trap of an 'in-flight capture' type is considered as a possible complex for producing of the short-lived nuclei in fragmentation reactions by heavy ions and for precise mass measurement of these nuclei. The plan of scientific and technical FLNR research includes a project DRIBs for producing beams of accelerated radioactive nuclear reaction products and photofission fragments. This project proposes also precise mass measurements of the fission fragment with the help of the ion trap. The in-flight entrance of the ions and their capture in the mass-spectrometric ion trap using the monochromatizing degrader, the static electric and magnetic fields and a new invention, a magnetic unidirectional transporting ventil, is considered

  20. Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Le Neindre, N.; Alderighi, M.; Anzalone, A.; Barna, R.; Bartolucci, M.; Berceanu, I.; Borderie, B.; Bougault, R.; Bruno, M.; Cardella, G.; Cavallaro, S.; D' Agostino, M. E-mail: dagostino@bo.infn.it; Dayras, R.; De Filippo, E.; De Pasquale, D.; Geraci, E.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Italiano, A.; Kowalski, S.; Lanchais, A.; Lanzano, G.; Lanzalone, G.; Li, S.; Lo Nigro, S.; Maiolino, C.; Manfredi, G.; Moisa, D.; Pagano, A.; Papa, M.; Paduszynski, T.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Politi, G.; Pop, A.; Porto, F.; Rivet, M.F.; Rosato, E.; Russo, S.; Sambataro, S.; Sechi, G.; Simion, V.; Sperduto, M.L.; Steckmeyer, J.C.; Sutera, C.; Trifiro, A.; Tassan-Got, L.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W

    2002-09-01

    Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus are presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlations between {delta}E and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.

  1. Aspect Ratio Dependence of Impact Fragmentation

    International Nuclear Information System (INIS)

    Inaoka, H.; Toyosawa, E.; Takayasu, H.; Inaoka, H.

    1997-01-01

    A numerical model of three-dimensional impact fragmentation produces a power-law cumulative fragment mass distribution followed by a flat tail. The result is consistent with an experimental result in a recent paper by Meibom and Balslev [Phys. Rev. Lett. 76, 2492 (1996)]. Our numerical simulation also implies that the fragment mass distribution changes from a power law with a flat tail to a power law with a sudden cutoff, depending on the aspect ratio of the fractured object. copyright 1997 The American Physical Society

  2. Implications of the Cosmological Constant for Spherically Symmetric Mass Distributions

    Science.gov (United States)

    Zubairi, Omair; Weber, Fridolin

    2013-04-01

    In recent years, scientists have made the discovery that the expansion rate of the Universe is increasing rather than decreasing. This acceleration leads to an additional term in Albert Einstein's field equations which describe general relativity and is known as the cosmological constant. This work explores the aftermath of a non-vanishing cosmological constant for relativistic spherically symmetric mass distributions, which are susceptible to change against Einstein's field equations. We introduce a stellar structure equation known as the Tolman-Oppenhiemer-Volkoff (TOV) equation modified for a cosmological constant, which is derived from Einstein's modified field equations. We solve this modified TOV equation for these spherically symmetric mass distributions and obtain stellar properties such as mass and radius and investigate changes that may occur depending on the value of the cosmological constant.

  3. THE MASS DISTRIBUTION OF COMPANIONS TO LOW-MASS WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Jeff J.; Price-Whelan, Adrian M.; Agüeros, Marcel A. [Department of Astronomy, Columbia University, 550 W 120th Street, New York, NY 10027 (United States)

    2014-12-20

    Measuring the masses of companions to single-line spectroscopic binary stars is (in general) not possible because of the unknown orbital plane inclination. Even when the mass of the visible star can be measured, only a lower limit can be placed on the mass of the unseen companion. However, since these inclination angles should be isotropically distributed, for a large enough, unbiased sample, the companion mass distribution can be deconvolved from the distribution of observables. In this work, we construct a hierarchical probabilistic model to infer properties of unseen companion stars given observations of the orbital period and projected radial velocity of the primary star. We apply this model to three mock samples of low-mass white dwarfs (LMWDs; M ≲ 0.45 M {sub ☉}) and a sample of post-common-envelope binaries. We use a mixture of two Gaussians to model the WD and neutron star (NS) companion mass distributions. Our model successfully recovers the initial parameters of these test data sets. We then apply our model to 55 WDs in the extremely low-mass (ELM) WD Survey. Our maximum a posteriori model for the WD companion population has a mean mass μ{sub WD} = 0.74 M {sub ☉}, with a standard deviation σ{sub WD} = 0.24 M {sub ☉}. Our model constrains the NS companion fraction f {sub NS} to be <16% at 68% confidence. We make samples from the posterior distribution publicly available so that future observational efforts may compute the NS probability for newly discovered LMWDs.

  4. Measurement of the jet fragmentation function and transverse profile in proton-proton collisions at a center-of-mass energy of 7 TeV with the ATLAS detector

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Akesson, Torsten Paul; Akimoto, Ginga; Akimov, Andrei; Akiyama, Kunihiro; 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; Aliyev, Magsud; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amoros, Gabriel; 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; Angerami, Aaron; Anghinolfi, Francis; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Archambault, John-Paul; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Asman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Atoian, Grigor; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Austin, Nicholas; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Bachy, Gerard; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barashkou, Andrei; Galtieri, Angela Barbaro; 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 Guimaraes da Costa, Joao; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Detlef; Bartsch, Valeria; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Battistoni, Giuseppe; Bauer, Florian; Bawa, Harinder Singh; Beare, Brian; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Benchouk, Chafik; Bendel, Markus; Benekos, Nektarios; Benhammou, Yan; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jurg; Bernardet, Karim; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertin, Antonio; Bertinelli, Francesco; Bertolucci, Federico; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; 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; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; 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; Boelaert, Nele; Boser, Sebastian; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bona, Marcella; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Boorman, Gary; Booth, Chris; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borroni, Sara; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Botterill, David; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozhko, Nikolay; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Braem, Andre; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Breton, Dominique; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodbeck, Timothy; Brodet, Eyal; Broggi, Francesco; Bromberg, Carl; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Brown, Heather; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Bucci, Francesca; Buchanan, James; Buchanan, Norman; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Buscher, Volker; Bugge, Lars; Buira-Clark, Daniel; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, Francois; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Cabrera Urban, 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; Cambiaghi, Mario; Cameron, David; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Garrido, Maria Del Mar Capeans; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Montoya, German D.Carrillo; Carter, Antony; Carter, Janet; Carvalho, Joao; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Cataneo, Fernando; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cauz, Diego; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Cevenini, Francesco; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; 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, Tingyang; Chen, Xin; Cheng, Shaochen; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciba, Krzysztof; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Ciubancan, Mihai; Clark, Allan G.; Clark, Philip; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Clifft, Roger; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H.; Coe, Paul; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Cojocaru, Claudiu; Colas, Jacques; Colijn, Auke-Pieter; Collard, Caroline; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Conde Muino, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cook, James; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, Maria Jose; Costanzo, Davide; Costin, Tudor; Cote, David; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crepe-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristobal; Donszelmann, Tulay Cuhadar; Curatolo, Maria; Curtis, Chris; Cwetanski, Peter; Czirr, Hendrik; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Silva, Paulo Vitor; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Daum, Cornelis; Dauvergne, Jean-Pierre; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Dawson, John; Daya, Rozmin; De, Kaushik; De Asmundis, Riccardo; De Castro, Stefano; De Castro Faria Salgado, Pedro; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; de la Taille, Christophe; de la Torre, Hector; De Lotto, Barbara; De Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; de Vivie De Regie, Jean-Baptiste; Dean, Simon; Debbe, Ramiro; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; del Papa, Carlo; del Peso, Jose; del Prete, Tarcisio; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delpierre, Pierre; Delruelle, Nicolas; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; 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 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; Diblen, Faruk; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Yagci, Kamile Dindar; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, Andre; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dobson, Marc; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; dos Anjos, Andre; Dosil, Mireia; Dotti, Andrea; Dova, Maria-Teresa; Dowell, John; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Drees, Jurgen; Dressnandt, Nandor; Drevermann, Hans; Driouichi, Chafik; Dris, Manolis; Dubbert, Jorg; Dubbs, Tim; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Duhrssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Duren, Michael; Ebenstein, William; Ebke, Johannes; Eckert, Simon; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Ehrich, Thies; 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; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; 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; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Felzmann, Ulrich; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipcic, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Fisher, Steve; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Flores Castillo, Luis; Flowerdew, Michael; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galyaev, Eugene; Gan, K.K.; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; Garcia, Carmen; Garcia Navarro, Jose Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaumer, Olivier; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geerts, Dani\\|{e}l Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Helene; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghez, Philippe; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilchriese, Murdock; Gilewsky, Valentin; 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; Giusti, Paolo; Gjelsten, Borge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Gopfert, Thomas; Goeringer, Christian; Gossling, Claus; Gottfert, Tobias; Goldfarb, Steven; Golling, Tobias; Golovnia, Serguei; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Goncalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonidec, Allain; Gonzalez, Saul; Gonzalez de la Hoz, Santiago; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorisek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Grabowska-Bold, Iwona; Grafstrom, Per; Grah, Christian; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenfield, Debbie; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guarino, Victor; Guest, Daniel; Guicheney, Christophe; Guida, Angelo; Guillemin, Thibault; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Andrea; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jorgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Donovan; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Mathieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frederic; Hensel, Carsten; Henss, Tobias; Medina Hernandez, Carlos; Hernandez Jimenez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hessey, Nigel; Hidvegi, Attila; Higon-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; 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; Homma, Yasuhiro; Hong, Tae Min; Hooft van Huysduynen, Loek; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Horton, Katherine; Hostachy, Jean-Yves; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Imbault, Didier; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Irles Quiles, Adrian; Ishikawa, Akimasa; Ishino, Masaya; 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; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jantsch, Andreas; Janus, Michel; Jarlskog, Goran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jez, Pavel; Jezequel, Stephane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joram, Christian; Jorge, Pedro; Joseph, John; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Keates, James Robert; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kelly, Marc; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kersevan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Ketterer, Christian; Keung, Justin; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Peter; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Lawrence; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimentov, Alexei; Klingenberg, Reiner; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Knobloch, Juergen; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kocnar, Antonin; Kodys, Peter; Koneke, Karsten; Konig, Adriaan; Koenig, Sebastian; Kopke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollar, Daniel; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Kopikov, Sergey; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamaki, Miikka Juhani; 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, James; Kraus, Jana; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Kruger, Hans; Kruker, Tobias; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuze, Masahiro; Kuzhir, Polina; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramon; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Landsman, Hagar; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Lebel, Celine; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Leltchouk, Mikhail; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Leveque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewandowska, Marta; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhihua; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Shengli; 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; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Losada, Marta; Loscutoff, Peter; Sterzo, Francesco Lo; 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, Dorthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Bjorn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lupi, Anna; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Macek, Bostjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mattig, Peter; Mattig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amelia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; 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; Mandic, Igor; Mandrysch, Rocco; Maneira, Jose; Mangeard, Pierre-Simon; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian Thomas; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; 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; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maxfield, Stephen; Maximov, Dmitriy; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meinhardt, Jens; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W.Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Miele, Paola; Migas, Sylwia; Mijovic, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuz, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Minano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A.; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjornmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Monig, Klaus; Moser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Mohrdieck-Mock, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; 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; Morii, Masahiro; Morin, Jerome; Morley, Anthony Keith; Mornacchi, Giuseppe; Morozov, Sergey; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Muller, Thomas; Muenstermann, Daniel; Muir, Alex; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Nesterov, Stanislav; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Hong, Van Nguyen Thi; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nordberg, Markus; Nordkvist, Bjoern; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nyman, Tommi; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olcese, Marco; Olchevski, Alexander; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, Antonio; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pasztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Cavalcanti, Tiago Perez; Perez Codina, Estel; Perez Garcia-Estan, Maria Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Peshekhonov, Vladimir; 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, Alan; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Pickford, Andrew; Piec, Sebastian Marcin; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pina, Joao Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommes, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Bueso, Xavier Portell; Porter, Robert; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Lawrence; Price, Michael John; Prichard, Paul; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Ramstedt, Magnus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rauter, Emanuel; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Reljic, Dusan; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rieke, Stefan; 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; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodier, Stephane; Rodriguez, Diego; Roe, Adam; Roe, Shaun; Rohne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romanov, Victor; Romeo, Gaston; 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; Rossi, Lucio; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Rubinskiy, Igor; Ruckert, Benjamin; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Ruhr, Frederik; Ruggieri, Federico; Ruiz-Martinez, Aranzazu; Rulikowska-Zarebska, Elzbieta; Rumiantsev, Viktor; Rumyantsev, Leonid; Runge, Kay; Runolfsson, Ogmundur; Rurikova, Zuzana; Rusakovich, Nikolai; Rust, Dave; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Ryadovikov, Vasily; Ryan, Patrick; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Rzaeva, Sevda; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, Jose; Salvachua Ferrando, Belen; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Bjorn Hallvard; Sanchez, Arturo; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, Joao; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Takashi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Savva, Panagiota; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scallon, Olivia; Scannicchio, Diana; Schaarschmidt, Jana; Schacht, Peter; Schafer, Uli; 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; Schlereth, James; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitz, Martin; Schoning, Andre; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, Jose; Sekhniaidze, Givi; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shichi, Hideharu; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siebel, Anca-Mirela; Siegert, Frank; Siegrist, James; Sijacki, Djordje; Silbert, Ohad; Silva, Jose; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjolin, Jorgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloper, John erik; Smakhtin, Vladimir; Smirnov, Sergei; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Sondericker, John; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sorbi, Massimo; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spano, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiriti, Eleuterio; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St. Denis, Richard Dante; Stahl, Thorsten; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Kyle; Stewart, Graeme; Stillings, Jan Andre; Stockmanns, Tobias; 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; Strohmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Succurro, Antonella; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sanchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Terwort, Mark; Testa, Marianna; Teuscher, Richard; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothee; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tian, Feng; Tic, Tom\\'{a}\\v{s}; Tikhomirov, Vladimir; Tikhonov, Yury; Timmermans, Charles; Tipton, Paul; Viegas, Florbela De Jes Tique Aires; Tisserant, Sylvain; Tobias, Jurgen; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokar, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torres, Heberth; Torro Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Traynor, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Trischuk, William; Trivedi, Arjun; Trocme, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; 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; Tyrvainen, Harri; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urkovsky, Evgeny; Urrejola, Pedro; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Ferrer, Juan Antonio Valls; Van der Graaf, Harry; van der Kraaij, Erik; van der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; Van Gemmeren, Peter; van Kesteren, Zdenko; Van Vulpen, Ivo; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; 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; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Anh, Tuan Vu; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Joshua C.; Wang, Rui; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Jens; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Weydert, Carole; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, 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; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wraight, Kenneth; Wright, Catherine; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wunstorf, Renate; Wynne, Benjamin; Xaplanteris, Leonidas; Xella, Stefania; Xie, Song; Xie, Yigang; Xu, Chao; Xu, Da; Xu, Guofa; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zaets, Vassilli; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zalite, Youris; Zanello, Lucia; Zarzhitsky, Pavel; Zaytsev, Alexander; Zeitnitz, Christian; Zeller, Michael; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Zenis, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi Della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Zivkovic, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2011-01-01

    The jet fragmentation function and transverse profile for jets with 25 GeV < ptJet < 500 GeV and etaJet<1.2 produced in proton-proton collisions with a center-of-mass energy of 7 TeV are presented. The measurement is performed using data with an integrated luminosity of 36 pb^-1. Jets are reconstructed and their momentum measured using calorimetric information. The momenta of the charged particle constituents are measured using the tracking system. The distributions corrected for detector effects are compared with various Monte Carlo event generators and generator tunes. Several of these choices show good agreement with the measured fragmentation function. None of these choices reproduce both the transverse profile and fragmentation function over the full kinematic range of the measurement.

  5. Models of fragmentation with composite power laws

    Science.gov (United States)

    Tavassoli, Z.; Rodgers, G. J.

    1999-06-01

    Some models for binary fragmentation are introduced in which a time dependent transition size produces two regions of fragment sizes above and below the transition size. In the first model we assume a fixed rate of fragmentation for the largest fragment and two different rates of fragmentation in the two regions of sizes above and below the transition size. The model is solved exactly in the long time limit to reveal stable time-invariant solutions for the fragment size and mass distributions. These solutions exhibit composite power law behaviours; power laws with two different exponents for fragments in smaller and larger regions. A special case of the model with no fragmentation in the smaller size region is also examined. Another model is also introduced which have three regions of fragment sizes with different rates of fragmentation. The similarities between the stable distributions in our models and composite power law distributions from experimental work on shock fragmentation of long thin glass rods and thick clay plates are discussed.

  6. Targeted Multiplex Imaging Mass Spectrometry with Single Chain Fragment Variable (scfv) Recombinant Antibodies

    Science.gov (United States)

    Thiery, Gwendoline; Mernaugh, Ray L.; Yan, Heping; Spraggins, Jeffrey M.; Yang, Junhai; Parl, Fritz F.; Caprioli, Richard M.

    2012-10-01

    Recombinant scfv antibodies specific for CYP1A1 and CYP1B1 P450 enzymes were combined with targeted imaging mass spectrometry to simultaneously detect the P450 enzymes present in archived, paraffin-embedded, human breast cancer tissue sections. By using CYP1A1 and CYP1B1 specific scfv, each coupled to a unique reporter molecule (i.e., a mass tag) it was possible to simultaneously detect multiple antigens within a single tissue sample with high sensitivity and specificity using mass spectrometry. The capability of imaging multiple antigens at the same time is a significant advance that overcomes technical barriers encountered when using present day approaches to develop assays that can simultaneously detect more than a single antigen in the same tissue sample.

  7. Effects of introduction of new resources and fragmentation of existing resources on limiting wealth distribution in asset exchange models

    Science.gov (United States)

    Ali Saif, M.; Gade, Prashant M.

    2009-03-01

    Pareto law, which states that wealth distribution in societies has a power-law tail, has been the subject of intensive investigations in the statistical physics community. Several models have been employed to explain this behavior. However, most of the agent based models assume the conservation of number of agents and wealth. Both these assumptions are unrealistic. In this paper, we study the limiting wealth distribution when one or both of these assumptions are not valid. Given the universality of the law, we have tried to study the wealth distribution from the asset exchange models point of view. We consider models in which (a) new agents enter the market at a constant rate (b) richer agents fragment with higher probability introducing newer agents in the system (c) both fragmentation and entry of new agents is taking place. While models (a) and (c) do not conserve total wealth or number of agents, model (b) conserves total wealth. All these models lead to a power-law tail in the wealth distribution pointing to the possibility that more generalized asset exchange models could help us to explain the emergence of a power-law tail in wealth distribution.

  8. Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice.

    Science.gov (United States)

    Andersen, Steven Arild Wuyts; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

    2015-10-01

    Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal in understanding skills acquisition and best-practice implementation and organization of training. To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training. A prospective trial with a 2 × 2 design was conducted at an academic teaching hospital. Participants included 43 novice medical students. Of these, 21 students completed time-distributed practice from October 14 to November 29, 2013, and a separate group of 19 students completed massed practice on May 16, 17, or 18, 2014. Data analysis was performed from June 6, 2014, to March 3, 2015. Participants performed 12 repeated virtual mastoidectomies using a temporal bone surgical simulator in either a distributed (practice blocks spaced in time) or massed (all practice in 1 day) training program with randomization for simulator-integrated tutoring during the first 5 sessions. Performance was assessed using a modified Welling Scale for final product analysis by 2 blinded senior otologists. Compared with the 19 students in the massed practice group, the 21 students in the distributed practice group were older (mean age, 25.1 years), more often male (15 [62%]), and had slightly higher mean gaming frequency (2.3 on a 1-5 Likert scale). Learning curves were established and distributed practice was found to be superior to massed practice, reported as mean end score (95% CI) of 15.7 (14.4-17.0) in distributed practice vs. 13.0 (11.9-14.1) with massed practice (P = .002). Simulator-integrated tutoring accelerated the initial performance, with mean score for tutored sessions of 14.6 (13.9-15.2) vs. 13.4 (12.8-14.0) for

  9. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide

    NARCIS (Netherlands)

    Chacko, Shaji K.; Sunehag, Agneta L.; Sharma, Susan; Sauer, Pieter J. J.; Haymond, Morey W.

    We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of

  10. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide.

    Science.gov (United States)

    We report a new method to measure the fraction of glucose derived from gluconeogenesis using gas chromatography-mass spectrometry and positive chemical ionization. After ingestion of deuterium oxide by subjects, glucose derived from gluconeogenesis is labeled with deuterium. Our calculations of gluc...

  11. Uniformity measure for power-law mass spectrum in nuclear fragmentation

    International Nuclear Information System (INIS)

    Wislicki, W.

    1992-11-01

    Description is given in terms of the Renyi entropy and the uniformity for the canonical ensemble, the grand canonical ensemble and the power-law probability measures. The study is presented of the power-law spectra of cluster masses observed in nuclear interactions in the vicinity of the liquid-gas transition point. 6 figs., 1 tab., 15 refs. (author)

  12. Nuclear fragmentation by nucleation approach

    International Nuclear Information System (INIS)

    Chung, K.C.

    1992-01-01

    The nucleation model is used to simulate nuclear fragmentation processes. The critical value of the effective interaction radius is shown to vary linearly with the expansion factor α. The calculated mass and charge distributions are compared with some experimental data. (author)

  13. Choice of initial conditions in dynamical calculations of distributions of nuclear fission fragments

    International Nuclear Information System (INIS)

    Kosenko, G.I.

    1993-01-01

    The distribution function in the coordinates and momenta for a fissioning system traversing a barrier is determined in terms of Langevin fluctuation-dissipation dynamics. It is shown that this distribution is best described by the Kramers distribution. The equilibrium distribution can be used as the initial condition, provided that the system is in the overdamping regime. 28 refs., 5 figs., 3 tabs

  14. A multivariate rank test for comparing mass size distributions

    KAUST Repository

    Lombard, F.

    2012-04-01

    Particle size analyses of a raw material are commonplace in the mineral processing industry. Knowledge of particle size distributions is crucial in planning milling operations to enable an optimum degree of liberation of valuable mineral phases, to minimize plant losses due to an excess of oversize or undersize material or to attain a size distribution that fits a contractual specification. The problem addressed in the present paper is how to test the equality of two or more underlying size distributions. A distinguishing feature of these size distributions is that they are not based on counts of individual particles. Rather, they are mass size distributions giving the fractions of the total mass of a sampled material lying in each of a number of size intervals. As such, the data are compositional in nature, using the terminology of Aitchison [1] that is, multivariate vectors the components of which add to 100%. In the literature, various versions of Hotelling\\'s T 2 have been used to compare matched pairs of such compositional data. In this paper, we propose a robust test procedure based on ranks as a competitor to Hotelling\\'s T 2. In contrast to the latter statistic, the power of the rank test is not unduly affected by the presence of outliers or of zeros among the data. © 2012 Copyright Taylor and Francis Group, LLC.

  15. Fragmentation Pathways of Trifluoroacetyl Derivatives of Methamphetamine, Amphetamine, and Methylenedioxyphenylalkylamine Designer Drugs by Gas Chromatography/Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Takeshi Kumazawa

    2011-01-01

    Full Text Available Methamphetamine (MA, amphetamine (AM, and the methylenedioxyphenylalkylamine designer drugs, such as 3,4-methylenedioxymethamphetamine (MDMA, 3,4-methylenedioxyethylamphetamine (MDEA, N-methyl-1-(3,4-methylenedioxyphenyl-2-butanamine (MBDB, 3,4-methylenedioxyamphetamine (MDA, and 3,4-(methylenedioxyphenyl-2-butanamine (BDB, are widely abused as psychedelics. In this paper, these compounds were derivatized with trifluoroacetic (TFA anhydride and analyzed by gas chromatography/mass spectrometry using electron ionization in positive mode. Gas chromatographic separation for TFA derivatives of all compounds was successfully resolved using an Equity-5 fused silica capillary column with a poly (5% diphenyl-95% dimethylsiloxane stationary phase. Base peaks or prominent peaks of MA, AM, MDMA, MDEA, MBDB, MDA, and BDB appeared at m/z 154, 140, 154, 168, 168, 135, and 135, respectively. These occurred due to α-cleavage from the amide nitrogen, splitting into the TFA imine species and benzyl or methylenedioxybenzyl cations. Further prominent fragment ions at m/z 118 for MA and AM, m/z 162 for MDMA, MDEA, and MDA, and m/z 176 for MBDB and BDB were produced by cleavage of the phenylpropane or methylenedioxypropane hydrocarbon radical cation via a hydrogen rearrangement. These fragmentation pathways for the TFA derivatives of all the compounds are summarized and illustrated in this paper.

  16. Fragmentation Pathways of Trifluoroacetyl Derivatives of Methamphetamine, Amphetamine, and Methylenedioxyphenyl alkylamine Designer Drugs by Gas Chromatography/Mass Spectrometry

    International Nuclear Information System (INIS)

    Kumazawa, T.; Xiao-Pen, L.; Sato, K.

    2011-01-01

    Methamphetamine (MA), amphetamine (AM), and the methylenedioxyphenyl alkylamine designer drugs, such as 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy ethylamphetamine (MDEA), N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB), 3,4-methylenedioxyamphetamine (MDA), and 3,4-(methylenedioxyphenyl)-2-butanamine (BDB), are widely abused as psychedelics. In this paper, these compounds were derivatized with trifluoroacetic (TFA) anhydride and analyzed by gas chromatography/mass spectrometry using electron ionization in positive mode. Gas chromatographic separation for TFA derivatives of all compounds was successfully resolved using an Equity-5 fused silica capillary column with a poly (5% diphenyl-95% dimethylsiloxane) stationary phase. Base peaks or prominent peaks of MA, AM, MDMA, MDEA, MBDB, MDA, and BDB appeared at m/z 154, 140, 154, 168, 168, 135, and 135, respectively. These occurred due to a-cleavage from the amide nitrogen, splitting into the TFA imine species and benzyl or methylenedioxybenzyl cations. Further prominent fragment ions at m/z 118 for MA and AM, m/z 162 for MDMA, MDEA, and MDA, and m/z 176 for MBDB and BDB were produced by cleavage of the phenylpropane or methylenedioxy propane hydrocarbon radical cation via a hydrogen rearrangement. These fragmentation pathways for the TFA derivatives of all the compounds are summarized and illustrated in this paper.

  17. Mass and charge distribution in heavy-ion collisions

    International Nuclear Information System (INIS)

    Beck, F.; Dworzecka, M.; Feldmeier, H.

    1978-01-01

    A statistical model based on the independent particle picture is used to calculate mass and charge distributions in deep inelastic heavy-ion collisions. Different assumptions on volume and charge equilibrations are compared with measured variances of charge distributions. One combination of assumptions is clearly favoured by experiment, and gives a reasonable description of the variance versus energy loss curves up to energy losses of about 200 MeV in the heavy systems Kr+Ho and Xe+Bi, and up to about 60 MeV for the light system Ar+Ca [af

  18. Fragmentation of Relativistic 56Fe Nuclei in Emulsion

    International Nuclear Information System (INIS)

    Chernov, G.M.; Gulamov, K.G.; Gulyamov, U.G.; Navotny, V.Sh.; Petrov, N.V.; Svechnikova, L.N.; Jakobsson, B.; Oskarsson, A.; Otterlund, I.

    1983-03-01

    Experimental data on general characteristics of projectile fragments in inelastic interactions of relativistic 56 Fe nuclei in emulsion (multiplicities, transverse momentum distributions, azimuthal correlations) are presented and discussed. A strong dependence on the mass number of the projectile nucleus is observed for the transverse momenta of the emitted projectile fragments. These fragments exhibit an azimuthal asymmetry caused by the transverse motion of the fragmenting residue, but it is shown that this motion can be responsible only for a part of the increase in the average transverse momentum of the fragments with increasing mass of the projectile. (author)

  19. Evaluation of mass distribution data from 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Liu Tingjin

    2003-01-01

    The mass distribution data of 252 Cf spontaneous fission were evaluated based on 7 sets of available experimental data. The measured data were corrected for the standards and γ intensity used by using the new evaluated ones. The errors were made necessary adjusting. The evaluated experimental data were fitted with spline function without any restriction and with symmetric restriction. These two sets of fit data were recommended as reference data of the mass distribution of 252 Cf spontaneous fission. The errors of the recommended data were considerably reduced comparing with the measured ones. The light and heavy peaks are not completely symmetric. Also there are fine structures on the right side of the light peak at A=109-111 and left side of the heavy peak at A=137-139. These should be paid attention and studied further. (author)

  20. Unexplained structure in (μ,π) invariant mass distribution

    International Nuclear Information System (INIS)

    Ramm, C.A.

    2000-01-01

    Structures in invariant mass distributions from (μ,π) combinations in the range 0.380 μ -π 0.470 GeV from neutrino and kaon experiments are presented in comparable formats. No artifacts have been found to account for any part of the structure. Hypotheses that the similarities are due to recurrent statistical fluctuations are beyond credibility. My conclusion is that the similarities are overwhelming evidence that the structure is of an unexplained physical origin. It includes an enhancement which would accord with the decay of a narrow (μ,π) state of mass 0.429 GeV. The purpose of this report is to request and enable every experimenter with precise M μ , π distributions to investigate their degree of correspondence with these analyses (author)

  1. Quark-diquark fragmentation in 'high mass' diffraction dissociation in proton-proton collisions at 360 GeV/c

    International Nuclear Information System (INIS)

    Asai, Makoto

    1986-01-01

    Using the European Hybrid spectrometer (EHS) system, we have investigated the properties of the four-prong 'high mass' diffraction dissociation process in the exclusive processes pp → pX, where X represents pπ + π - nπ 0 (n = 0, 1, 2). We present experimental evidences that Pomeron couples with a single valence quark in the incident proton and that the other two valence quarks in the proton behaves as the spectator diquark. We also show that most of the baryons are produced from the spectator diquark system in these processes. The p t suppression is also shown in the Gottfried-Jackson frame, the frame in which the excited system composed of Pomeron and the incident proton is at rest. Characteristic features in the hadronization of this process are very much similar to those of quark-diquark fragmentation in lepton-hardron deep inelastic scattering. (author)

  2. Mass distribution for the two-photon channel

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Mass distribution for the two-photon channel. The strongest evidence for this new particle comes from analysis of events containing two photons. The smooth dotted line traces the measured background from known processes. The solid line traces a statistical fit to the signal plus background. The new particle appears as the excess around 126.5 GeV. The full analysis concludes that the probability of such a peak is three chances in a million.

  3. Mass distribution for the four-lepton channel.

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Mass distribution for the four-lepton channel. The search with the purest expected signal is done by examining events with two Z bosons that have decayed to pairs of electrons or muons. In the region from 120 to 130 GeV, 13 events are seen where only 5.3 were expected. The complete analysis concludes that the probability of such an excess would be three times in ten thousand if there were no new particle.

  4. Functional traits variation explains the distribution of Aextoxicon punctatum (Aextoxicaceae in pronounced moisture gradients within fog-dependent forest fragments

    Directory of Open Access Journals (Sweden)

    Beatriz eSalgado-Negret

    2015-07-01

    Full Text Available Climate change and fragmentation are major threats to world forests. Understanding how functional traits related to drought tolerance change across small-scale, pronounced moisture gradients in fragmented forests is important to predict species’ responses to these threats. In the case of Aextoxicon punctatum, a dominant canopy tree in fog-dependent rain forest patches in semiarid Chile, we explored how the magnitude, variability and correlation patterns of leaf and xylem vessel traits and hydraulic conductivity varied across soil moisture gradients established within and among forest patches of different size, which are associated with differences in tree establishment and mortality patterns. Leaf traits varied across soil-moisture gradients produced by fog interception. Trees growing at drier leeward edges showed higher LMA (leaf mass per area, trichome and stomatal density than trees from the wetter core and windward zones. In contrast, xylem vessel traits (vessels diameter and density did not vary producing loss of hydraulic conductivity at drier leeward edges. We also detected higher levels of phenotypic integration and variability at leeward edges. The ability of A. punctatum to modify leaf traits in response to differences in soil moisture availability established over short distances (<500 m facilitates its persistence in contrasting microhabitats within forest patches. However, xylem anatomy showed limited plasticity, which increases cavitation risk at leeward edges. Greater patch fragmentation, together with fluctuations in irradiance and soil moisture in small patches, could result in higher risk of drought-related tree mortality, with profound impacts on hydrological balances at the ecosystem scale.

  5. Sulphur-containing compounds in the essential oil of Ferula alliacea roots and their mass spectral fragmentation patterns.

    Science.gov (United States)

    Kasaian, Jamal; Asili, Javad; Iranshahi, Mehrdad

    2016-10-01

    Context GC-MS analysis is the best way to characterize volatile sulphur-containing compounds. Ferula (Apiaceae) is a genus of perennial herbs. Due to the occurrence of essential oils or oleoresins in the Ferula species, these plants usually possess strong aromatic scent. Terpenoid compounds were the most abundant constituents of Ferula oils, however, in some of Ferula species, the essential oils were dominated by volatile sulphur-containing compounds. Objectives Ferula alliacea Boiss. is considered one of the sources of the oleo-gum-resin asafoetida. In this study, we analyzed the hydrodistilled essential oil from its dried roots and provide new data about retention indices and mass fragmentation patterns of some volatile sulphur-containing compounds that are useful for future studies on this class of compounds. Materials and methods The roots of F. alliacea were collected during the flowering stage of plant, from Bezgh, Kashmar to Neishabour road, Khorasan-Razavi province, Iran, in June 2012. The oil was obtained by hydrodistillation using a Clevenger apparatus and analyzed by GC-MS. Results This is the first report on phytochemical analysis of F. alliacea roots. Seventy-six components, representing 99.5% of the oil, were characterized. The major components were 10-epi-γ-eudesmol (22.3%), valerianol (12.5%), hinesol (8.3%), guaiol (7.3%) and Z-propenyl-sec-butyl trisulphide (6.5%). Predominant mass fragment ions of the identified sulphur-containing compounds are explained in this paper. Conclusion The volatile oil of F. alliacea mostly contains oxygenated sesquiterpenes, however, its odour was dominated by sulphur-containing compounds. The most abundant sulphur-containing compound includes Z-propenyl-sec-butyl trisulphide (6.5%).

  6. Mass measurement errors of Fourier-transform mass spectrometry (FTMS): distribution, recalibration, and application.

    Science.gov (United States)

    Zhang, Jiyang; Ma, Jie; Dou, Lei; Wu, Songfeng; Qian, Xiaohong; Xie, Hongwei; Zhu, Yunping; He, Fuchu

    2009-02-01

    The hybrid linear trap quadrupole Fourier-transform (LTQ-FT) ion cyclotron resonance mass spectrometer, an instrument with high accuracy and resolution, is widely used in the identification and quantification of peptides and proteins. However, time-dependent errors in the system may lead to deterioration of the accuracy of these instruments, negatively influencing the determination of the mass error tolerance (MET) in database searches. Here, a comprehensive discussion of LTQ/FT precursor ion mass error is provided. On the basis of an investigation of the mass error distribution, we propose an improved recalibration formula and introduce a new tool, FTDR (Fourier-transform data recalibration), that employs a graphic user interface (GUI) for automatic calibration. It was found that the calibration could adjust the mass error distribution to more closely approximate a normal distribution and reduce the standard deviation (SD). Consequently, we present a new strategy, LDSF (Large MET database search and small MET filtration), for database search MET specification and validation of database search results. As the name implies, a large-MET database search is conducted and the search results are then filtered using the statistical MET estimated from high-confidence results. By applying this strategy to a standard protein data set and a complex data set, we demonstrate the LDSF can significantly improve the sensitivity of the result validation procedure.

  7. Distribution of mitochondrial nucleoids upon mitochondrial network fragmentation and network reintegration in HEPG2 cells

    Czech Academy of Sciences Publication Activity Database

    Tauber, Jan; Dlasková, Andrea; Šantorová, Jitka; Smolková, Katarína; Alán, Lukáš; Špaček, Tomáš; Plecitá-Hlavatá, Lydie; Ježek, Petr

    2013-01-01

    Roč. 45, č. 3 (2013), s. 593-603 ISSN 1357-2725 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GPP304/10/P204; GA ČR(CZ) GAP305/12/1247 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : mitochondrial DNA nucleoids * mitochondrial fission * mitochondrial network fragmentation * mitochondrial network reintegration Subject RIV: ED - Physiology Impact factor: 4.240, year: 2013

  8. Isotopic distributions of the sup 1 sup 8 N fragmentation products in coincidence with neutrons on targets sup 1 sup 9 sup 7 Au and sup 9 Be

    CERN Document Server

    Li Xiang Qing; Ye Yan Lin; Hua Hui; Chen Tao; Li Zhi Huan; Ge Yuch Eng; Wang Quan Jin; Wu He Yu; Jin Ge; Duan Li Min; Xiao Zhi Gang; Wang Hong Wei; Li Zhu Yu; Wang Su Fang

    2002-01-01

    The authors present the experimental isotopic distributions of the sup 1 sup 8 N projectile fragmentation products Li, Be, B and C in coincidence with neutrons, as well as the inclusive ones on sup 1 sup 9 sup 7 Au and sup 9 Be targets. In the framework of the abrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projectile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence with neutrons shows that the information on the nucleon density distribution of the sup 1 sup 8 N projectile can be extracted

  9. Angular distribution of fragments from neutron-induced fission of 238U in the intermediate energy region

    International Nuclear Information System (INIS)

    Carlsson, Magnus

    2004-06-01

    Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of 238 U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of 238 U

  10. DLNA: a simple one-dimensional dynamical model as a possible interpretation of fragment size distribution in nuclear multifragmentation

    International Nuclear Information System (INIS)

    Lacroix, D.; Dayras, R.

    1996-08-01

    The possibility of interpreting multifragmentation data obtained from heavy-ion collisions at intermediate energies, by a new type of model: the DLNA (Dynamical Limited Nuclear Aggregation) is discussed. This model is connected to a more general class of models presenting Self-Organization Criticality (SOC). It is shown that the fragment size distributions exhibit a power-law dependence comparable to those obtained in second-order phase transition or percolation models. Fluctuations in term of scaled-factorial moments and cumulants are also studied: no signal of intermittency is seen. (K.A.)

  11. Fragmentation analysis of water-soluble atmospheric organic matter using ultrahigh-resolution FT-ICR mass spectrometry.

    Science.gov (United States)

    Leclair, Jeffrey P; Collett, Jeffrey L; Mazzoleni, Lynn R

    2012-04-17

    Isolated water-soluble atmospheric organic matter (AOM) analytes extracted from radiation fogwater samples were analyzed using collision induced dissociation with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Tandem mass analysis was performed on several mass ranges between 100 and 400 Da to characterize the functional groups of AOM species. Compounds containing nitrogen and/or sulfur were targeted because of the high number of oxygen atoms contained in their molecular formulas. Due to the large number of isobaric ions in the precursor isolation ranges, large numbers of product ions resulted from collision induced dissociation. Common neutral losses were assigned by matching the molecular formulas of the expected product ions with the detected product ions within the appropriate mass spectra. Since polar functional groups are expected to affect the hygroscopic properties of aerosols, the losses of H(2)O, CO(2), CH(3)OH, HNO(3), CH(3)NO(3), SO(3), SO(4) and combinations of these were specifically targeted. Among the 421 compounds studied, the most frequently observed neutral losses were CO(2) (54%), H(2)O (43%) and CH(3)OH (40%). HNO(3) losses were observed for 63% of the studied nitrogen containing compounds and 33% of the studied compounds containing both nitrogen and sulfur. SO(3) losses were observed for 85% of the studied sulfur containing compounds and 42% of studied compounds containing both nitrogen and sulfur. A number of molecular formulas matching those of monoterpene ozonolysis SOA were observed; they include organonitrates, organosulfates, and nitroxy-organosulfates. Overall, the results of fragmentation analysis of 400+ individual molecular precursors elucidate the complexity and multifunctional nature of the isolated water-soluble AOM.

  12. Neutron-induced fission fragment angular distribution at CERN n TOF: The Th-232 case

    CERN Document Server

    Tarrio, Diego; Paradela, Carlos

    This thesis work was done in the frame of the study of the neutron-induced fission of actinides and subactinides at the CERN n TOF facility using a fast Parallel Plate Avalanche Counters (PPACs) setup. This experimental setup provide us with an intense neutron beam with a white spectrum from thermal to 1 GeV and with an outstanding high resolution provided by its flight path of 185 m. In our experiment, fission events were identified by detection of both fission fragments in time coincidence in the two PPAC detectors flanking the corresponding target. This technique allowed us to discriminate the fission events from the background produced by α disintegration of radioactive samples and by particles produced in spallation reactions. Because PPAC detectors are insensitive to the γ flash, it is possible to reach energies as high as 1 GeV. The stripped cathodes provide the spatial position of the hits in the detectors, so that the emission angle of the fission fragments can be measured. Inside the reaction cham...

  13. Elemental mass size distribution of the Debrecen urban aerosol

    International Nuclear Information System (INIS)

    Kertesz, Zs.; Szoboszlai, Z.; Dobos, E.; Borbely-Kiss, I.

    2007-01-01

    Complete text of publication follows. Size distribution is one of the basic properties of atmospheric aerosol. It is closely related to the origin, chemical composition and age of the aerosol particles, and it influences the optical properties, environmental effects and health impact of aerosol. As part of the ongoing aerosol research in the Group of Ion Beam Applications of the Atomki, elemental mass size distribution of urban aerosol were determined using particle induced X-ray emission (PIXE) analytical technique. Aerosol sampling campaigns were carried out with 9-stage PIXE International cascade impactors, which separates the aerosol into 10 size fractions in the 0.05-30 ?m range. Five 48-hours long samplings were done in the garden of the Atomki, in April and in October, 2007. Both campaigns included weekend and working day samplings. Basically two different kinds of particles could be identified according to the size distribution. In the size distribution of Al, Si, Ca, Fe, Ba, Ti, Mn and Co one dominant peak can be found around the 3 m aerodynamic diameter size range, as it is shown on Figure 1. These are the elements of predominantly natural origin. Elements like S, Cl, K, Zn, Pb and Br appears with high frequency in the 0.25-0.5 mm size range as presented in Figure 2. These elements are originated mainly from anthropogenic sources. However sometimes in the size distribution of these elements a 2 nd , smaller peak appears at the 2-4 μm size ranges, indicating different sources. Differences were found between the size distribution of the spring and autumn samples. In the case of elements of soil origin the size distribution was shifted towards smaller diameters during October, and a 2 nd peak appeared around 0.5 μm. A possible explanation to this phenomenon can be the different meteorological conditions. No differences were found between the weekend and working days in the size distribution, however the concentration values were smaller during the weekend

  14. A midrapidity source of intermediate mass fragments in highly central collisions of Au+Au at 150 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Alard, J P; Bastid, N; Crouau, M; Dupieux, P; Fraysse, L; Jorio, M; Montarou, G; Morel, P [Laboratoire de Physique Corpusculaire, 63 - Clermont-Ferrand (France); Basrak, Z; Caplar, R; Cindro, N; Hoelbling, S [Rudjer Boskovic Inst., Zagreb (Yugoslavia); Belayev, I M; Frolov, S; Korchagin, Y; Lebedev, A; Smolyankin, S; Zhilin, A V [Institute for Experimental and Theoretical Physics, Moscow (Russia); Bini, M; Olmi, A; Pasquali, G; Poggi, G; Taccetti, N [Florence Univ. (Italy); [INFN, Florence (Italy); Blaich, T [Mainz Univ. (Germany); Buta, A; Legrand, I; Moisa, D; Petrovici, M; Simion, V [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cerruti, C; Coffin, J P; Fintz, P; Guillaume, G; Houari, O; Jundt, F; Kuhn, C; Maguire, C; Rami, F; Tezkratt, R; Wagner, P [Centre de Recherches Nucleaires, 67 - Strasbourg (France); [Strasbourg Univ., 67 (France); Eroe, J; Fodor, Z; Kecskemeti, J; Koncz, P; Seres, Z [Central Research Inst. for Physics, Budapest (Hungary); Grigoriyan, Y; Manko, V; Mgebrishvili, G; Sadchikov, A; Vasiliev, M A [Kurchatov Inst. for Atomic Energy, Moscow (Russia); Herrmann, N; Pelte, D; Trzaska, M; Wienold, T [Heidelberg Univ. (Germany). Physikalisches Inst.; Kotte, R; Moesner, J; Neubert, W; Wohlfarth, D [Forschungszentrum Rossendorf (Germany); Matulewicz, T; Sikora, B; Wilhelmi, Z [Warsaw Univ. (Poland). Inst. of Experimental Physics; Bock, R; Fan, Z G; Freifelder, R; Gobbi, A; Hildenbrand, K D; Jeong, S C; Kraemer, M; Reisdorf, W; Schuell, D; Sodan, U; Teh, K; Wessels, J P; FOPI Collaboration at GSI

    1992-02-01

    Charged particles have been observed in collisions of Au on Au at incident energy of 150 A MeV using a high-granularity detector system covering approximatley the forward hemisphere in the center-of-mass system. Highly central collisions have been studied using a double selection criterion which combines large charged particle multiplicities with small transverse momentum directivities. In this class of events about one quarter of the total nuclear charge emerges as intermediate mass fragments with nuclear charges Z>2. These fragments are centred at midrapidity and are produced with large transverse velocities. (orig.).

  15. A midrapidity source of intermediate mass fragments in highly central collisions of Au+Au at 150 A MeV

    International Nuclear Information System (INIS)

    Alard, J.P.; Bastid, N.; Crouau, M.; Dupieux, P.; Fraysse, L.; Jorio, M.; Montarou, G.; Morel, P.; Basrak, Z.; Caplar, R.; Cindro, N.; Hoelbling, S.; Belayev, I.M.; Frolov, S.; Korchagin, Y.; Lebedev, A.; Smolyankin, S.; Zhilin, A.V.; Bini, M.; Olmi, A.; Pasquali, G.; Poggi, G.; Taccetti, N.; Blaich, T.; Buta, A.; Legrand, I.; Moisa, D.; Petrovici, M.; Simion, V.; Cerruti, C.; Coffin, J.P.; Fintz, P.; Guillaume, G.; Houari, O.; Jundt, F.; Kuhn, C.; Maguire, C.; Rami, F.; Tezkratt, R.; Wagner, P.; Eroe, J.; Fodor, Z.; Kecskemeti, J.; Koncz, P.; Seres, Z.; Grigoriyan, Y.; Manko, V.; Mgebrishvili, G.; Sadchikov, A.; Vasiliev, M.A.; Herrmann, N.; Pelte, D.; Trzaska, M.; Wienold, T.; Matulewicz, T.; Sikora, B.; Wilhelmi, Z.; Bock, R.; Fan, Z.G.; Freifelder, R.; Gobbi, A.; Hildenbrand, K.D.; Jeong, S.C.; Kraemer, M.; Reisdorf, W.; Schuell, D.; Sodan, U.; Teh, K.; Wessels, J.P.

    1992-02-01

    Charged particles have been observed in collisions of Au on Au at incident energy of 150 A MeV using a high-granularity detector system covering approximatley the forward hemisphere in the center-of-mass system. Highly central collisions have been studied using a double selection criterion which combines large charged particle multiplicities with small transverse momentum directivities. In this class of events about one quarter of the total nuclear charge emerges as intermediate mass fragments with nuclear charges Z>2. These fragments are centred at midrapidity and are produced with large transverse velocities. (orig.)

  16. Multi-Scale Particle Size Distributions of Mars, Moon and Itokawa based on a time-maturation dependent fragmentation model

    Science.gov (United States)

    Charalambous, C. A.; Pike, W. T.

    2013-12-01

    We present the development of a soil evolution framework and multiscale modelling of the surface of Mars, Moon and Itokawa thus providing an atlas of extra-terrestrial Particle Size Distributions (PSD). These PSDs are profoundly based on a tailoring method which interconnects several datasets from different sites captured by the various missions. The final integrated product is then fully justified through a soil evolution analysis model mathematically constructed via fundamental physical principles (Charalambous, 2013). The construction of the PSD takes into account the macroscale fresh primary impacts and their products, the mesoscale distributions obtained by the in-situ data of surface missions (Golombek et al., 1997, 2012) and finally the microscopic scale distributions provided by Curiosity and Phoenix Lander (Pike, 2011). The distribution naturally extends at the magnitudinal scales at which current data does not exist due to the lack of scientific instruments capturing the populations at these data absent scales. The extension is based on the model distribution (Charalambous, 2013) which takes as parameters known values of material specific probabilities of fragmentation and grinding limits. Additionally, the establishment of a closed-form statistical distribution provides a quantitative description of the soil's structure. Consequently, reverse engineering of the model distribution allows the synthesis of soil that faithfully represents the particle population at the studied sites (Charalambous, 2011). Such representation essentially delivers a virtual soil environment to work with for numerous applications. A specific application demonstrated here will be the information that can directly be extracted for the successful drilling probability as a function of distance in an effort to aid the HP3 instrument of the 2016 Insight Mission to Mars. Pike, W. T., et al. "Quantification of the dry history of the Martian soil inferred from in situ microscopy

  17. Fluctuations in projectile fragment distributions from 1 GeV/nucleon Au + C multifragmentation

    International Nuclear Information System (INIS)

    Elliott, J.B.; Gilkes, M.L.; Hauger, A.; Hirsch, A.S.

    1993-01-01

    Fluctuations in cluster distributions play an important role in distinguishing critical and non-critical cluster forming phenomena. The magnitude of the reduced variance (γ 2 ) of a cluster distribution is a direct measure of the size of its fluctuations. Preliminary examinations of γ 2 are made for cluster distributions from 1 GeV/nucleon Au+C data obtained in the EOS experiment at the Bevalac. Values of γ 2 are compared to those from percolation and statistical multifragmentation models

  18. A study of jet mass distributions with grooming

    Science.gov (United States)

    Marzani, Simone; Schunk, Lais; Soyez, Gregory

    2017-07-01

    We perform a phenomenological study of the invariant mass distribution of hadronic jets produced in proton-proton collisions, in conjunction with a grooming algorithm. In particular, we consider the modified MassDrop Tagger (mMDT), which corresponds to Soft Drop with angular exponent β = 0. Our calculation, which is differential in both jet mass and jet transverse momentum, resums large logarithms of the jet mass, including the full dependence on the groomer's energy threshold z cut, and it is matched to fixed-order QCD matrix elements at next-to-leading order. In order to account for non-perturbative contributions, originating from the hadronisation process and from the underlying event, we also include a phenomenological correction factor derived from Monte Carlo parton shower simulations. Furthermore, we consider two different possibilities for the jet transverse momentum: before or after grooming. We show that the former should be preferred for comparisons with upcoming experimental data essentially because the mMDT transverse momentum spectrum is not collinear safe, though the latter exhibits less sensitivity to underlying event and displays properties that may provide complementary information for probing non-perturbative effects.

  19. Fragmentation pathways and structural characterization of organophosphorus compounds related to the Chemical Weapons Convention by electron ionization and electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Hosseini, Seyed Esmaeil; Saeidian, Hamid; Amozadeh, Ali; Naseri, Mohammad Taghi; Babri, Mehran

    2016-12-30

    For unambiguous identification of Chemical Weapons Convention (CWC)-related chemicals in environmental samples, the availability of mass spectra, interpretation skills and rapid microsynthesis of suspected chemicals are essential requirements. For the first time, the electron ionization single quadrupole and electrospray ionization tandem mass spectra of a series of O-alkyl N-[bis(dimethylamino)methylidene]-P-methylphosphonamidates (Scheme 1, cpd 4) were studied for CWC verification purposes. O-Alkyl N-[bis(dimethylamino)methylidene]-P-methylphosphonamidates were prepared through a microsynthetic method and were analyzed using electron ionization and electrospray ionization mass spectrometry with gas and liquid chromatography, respectively, as MS-inlet systems. General EI and ESI fragmentation pathways were proposed and discussed, and collision-induced dissociation studies of the protonated derivatives of these compounds were performed to confirm proposed fragment ion structures by analyzing mass spectra of deuterated analogs. Mass spectrometric studies revealed some interesting fragmentation pathways during the ionization process, such as McLafferty rearrangement, hydrogen rearrangement and a previously unknown intramolecular electrophilic aromatic substitution reaction. The EI and ESI fragmentation routes of the synthesized compounds 4 were investigated with the aim of detecting and identifying CWC-related chemicals during on-site inspection and/or off-site analysis and toxic chemical destruction monitoring. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Compression behavior of cellular metals with inhomogeneous mass distribution

    International Nuclear Information System (INIS)

    Foroughi, B.

    2001-05-01

    Mechanical behavior of two types of closed cell metals (ALULIGHT and ALPORAS) is investigated experimentally and numerically. Compressive tests performed on prismatic specimens indicate that inhomogeneities in the mass density distribution are a key factor in the deformation behavior of cellular metals. The three dimensional cellular structure of the investigated specimens is recorded using x-ray medical computed tomography (CT). A special procedure called density mapping method has been used to transfer the recorded CT data into a continuum by averaging over a certain domain (averaging domain). This continuum model is implemented using finite elements to study the effect of variations in local mass densities. The finite element model is performed by a simple regular discretization of a specimen's volume with elements which have constant edge length. Mechanical properties derived from compression tests of ALPORAS samples are assigned to the corresponding mesoscopic density value of each element. The effect of averaging domain size is studied to obtain a suitable dimension which fulfils the homogenization requirements and allows the evaluation of inhomogenities in the specimens. The formation and propagation of deformation band(s) and stress-strain responses of tested cellular metals are modeled with respect to their mass distribution. It is shown that the inhomogeneous density distribution leads to plastic strain localization and causes a monotonically increase of the stress in the plateau regime although no hardening response was considered for homogeneous material in this regime. The simulated plastic strain localization and the calculated stress-strain responses are compared with the experimental results. The stiffness values of experiment and simulation agree very well for both cellular materials. The values of plateau strength as well, but it differs in some cases of ALULIGHT samples, where the hardening response can be predicted at least qualitatively

  1. Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2015-04-28

    The mass (volume and areal densities) versus velocity as well as the size versus velocity distributions of a shock-induced cloud of particles are investigated using large scale molecular dynamics simulations. A generic three-dimensional tin crystal with a sinusoidal free surface roughness (single wavelength) is set in contact with vacuum and shock-loaded so that it melts directly on shock. At the reflection of the shock wave onto the perturbations of the free surface, two-dimensional sheets/jets of liquid metal are ejected. The simulations show that the distributions may be described by an analytical model based on the propagation of a fragmentation zone, from the tip of the sheets to the free surface, in which the kinetic energy of the atoms decreases as this zone comes closer to the free surface on late times. As this kinetic energy drives (i) the (self-similar) expansion of the zone once it has broken away from the sheet and (ii) the average size of the particles which result from fragmentation in the zone, the ejected mass and the average size of the particles progressively increase in the cloud as fragmentation occurs closer to the free surface. Though relative to nanometric scales, our model may help in the analysis of experimental profiles.

  2. Fission Fragment Angular Distributions in the $^{234}$U(n,f) and $^{236}$U(n,f) reactions

    CERN Multimedia

    We propose to measure the fission fragment angular distribution (FFAD) of the $^{234}$U(n,f) and $^{236}$U (n,f) reactions with the PPAC detection setup used in previous n_TOF-14 experiment. This experiment would take advantage of the high resolution of the n_TOF facility to investigate the FFAD behaviour in the pronounced vibrational resonances that have been observed between 0.1 and 2 MeV for the thorium cycle isotopes. In addition, the angular distribution of these isotopes will be measured for the first time beyond 14 MeV. Furthermore, the experiment will also provide the fission cross section with reduced statistical uncertainty, extending the $^{236}$U(n,f) data up to 1 GeV

  3. Controlled fragmentation

    International Nuclear Information System (INIS)

    Arnold, Werner

    2002-01-01

    Contrary to natural fragmentation, controlled fragmentation offers the possibility to adapt fragment parameters like size and mass to the performance requirements in a very flexible way. Known mechanisms like grooves inside the casing, weaken the structure. This is, however, excluded for applications with high accelerations during launch or piercing requirements for example on a semi armor piercing penetrator. Another method to achieve controlled fragmentation with an additional grid layer is presented with which the required grooves are produced 'just in time' inside the casing during detonation of the high explosive. The process of generating the grooves aided by the grid layer was studied using the hydrocode HULL with respect to varying grid designs and material combinations. Subsequent to this, a large range of these theoretically investigated combinations was contemplated in substantial experimental tests. With an optimised grid design and a suitable material selection, the controlled fragment admits a very flexible adaptation to the set requirements. Additional advantages like the increase of perforation performance or incendiary amplification can be realized with the grid layer

  4. Phenotyping polyclonal kappa and lambda light chain molecular mass distributions in patient serum using mass spectrometry.

    Science.gov (United States)

    Barnidge, David R; Dasari, Surendra; Ramirez-Alvarado, Marina; Fontan, Adrian; Willrich, Maria A V; Tschumper, Renee C; Jelinek, Diane F; Snyder, Melissa R; Dispenzieri, Angela; Katzmann, Jerry A; Murray, David L

    2014-11-07

    We previously described a microLC-ESI-Q-TOF MS method for identifying monoclonal immunoglobulins in serum and then tracking them over time using their accurate molecular mass. Here we demonstrate how the same methodology can be used to identify and characterize polyclonal immunoglobulins in serum. We establish that two molecular mass distributions observed by microLC-ESI-Q-TOF MS are from polyclonal kappa and lambda light chains using a combination of theoretical molecular masses from gene sequence data and the analysis of commercially available purified polyclonal IgG kappa and IgG lambda from normal human serum. A linear regression comparison of kappa/lambda ratios for 74 serum samples (25 hypergammaglobulinemia, 24 hypogammaglobulinemia, 25 normal) determined by microflowLC-ESI-Q-TOF MS and immunonephelometry had a slope of 1.37 and a correlation coefficient of 0.639. In addition to providing kappa/lambda ratios, the same microLC-ESI-Q-TOF MS analysis can determine the molecular mass for oligoclonal light chains observed above the polyclonal background in patient samples. In 2 patients with immune disorders and hypergammaglobulinemia, we observed a skewed polyclonal molecular mass distribution which translated into biased kappa/lambda ratios. Mass spectrometry provides a rapid and simple way to combine the polyclonal kappa/lambda light chain abundance ratios with the identification of dominant monoclonal as well as oligoclonal light chain immunoglobulins. We anticipate that this approach to evaluating immunoglobulin light chains will lead to improved understanding of immune deficiencies, autoimmune diseases, and antibody responses.

  5. Generalised extreme value distributions provide a natural hypothesis for the shape of seed mass distributions.

    Directory of Open Access Journals (Sweden)

    Will Edwards

    Full Text Available Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually log-transformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs, a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm.

  6. Attentionally splitting the mass distribution of hand-held rods.

    Science.gov (United States)

    Burton, G; Turvey, M T

    1991-08-01

    Two experiments on the length-perception capabilities of effortful or dynamic touch differed only in terms of what the subject intended to perceive, while experimental conditions and apparatus were held constant. In each trial, a visually occluded rod was held as still as possible by the subject at an intermediate position. For two thirds of the trials, a weight was attached to the rod above or below the hand. In Experiment 1, in which the subject's task was to perceive the distance reachable with the portion of the rod forward of the hand, perceived extent was a function of the first moment of the mass distribution associated with the forward portion of the rod, and indifferent to the first moment of the entire rod. In Experiment 2, in which the task was to perceive the distance reachable with the entire rod if it was held at an end, the pattern of results was reversed. These results indicate the capability of selective sensitivity to different aspects of a hand-held object's mass distribution, without the possibility of differential exploration specific to these two tasks. Results are discussed in relation to possible roles of differential information, intention, and self-organization in the explanations of selective perceptual abilities.

  7. Mass and Angular Distributions of Charged Dihadron Production

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Mary Clare [Michigan U.

    1990-01-01

    Experiment 711, conducted at Fermilab. provided a unique handle towards understanding valence quark scattering by studying pairs of single. charged, high transverse momentum hadrons produced in collisions of 800 GeV /c protons on fixed metal targets. The apparatus consisted of a double-arm spectrometer. calorimetrically triggered. with high momentum resolution and a large angular acceptance for all charge states of particle pairs. The experiment was designed to select those hadron pairs that carrted most of the momentum and energy of the underlying scattered quarks and gluons. The charge of such "leading" hadrons is correlated with the charge of the quark that produced it. Quantum Chromodynamics (QCD) assumes that the scattering behavior of quarks ts independent of their charge, or "flavour": Experiment 711 could test this assumption. Tilis dissertation descrtbes the analysis of the mass and angular distributions of hadron pair production for three separate charge states: +-, ++ and --. The angular distributions are found to deviate from theory predictions of flavour symmetry. Also. the mass cross sections indicate ratios of positive to negative hard-scattered particles that are larger than expected from theory. These results could warrant reconsideration of the assumptions and approximations currently made in leading-order QCD calculations.

  8. Distribution and dosimetry of indium-111 labeled F(ab')2 fragments in humans

    International Nuclear Information System (INIS)

    Doherty, P.; Schwinger, R.; King, M.; Gionet, M.

    1986-01-01

    The purpose of this study was to obtain quantitative biodistribution data in patients injected with the indium-111 labeled F(ab') 2 fragments of mouse monoclonal antibody. From this data dosimetric calculations were made for the individual organs. The authors also evaluated the quantitative properties of SPECT in this application and compared it with the more conventional two view planar technique in both phantom and patient studies. For one antibody (19-9) the mean dose in rads/mCi for the organs of highest accumulation, namely, the liver and kidneys was 3.2 and 2.6 respectively. Preliminary data from another antibody (OC 125) showed much higher blood levels and a significantly lower liver dose of 2.3 indicating that antibody type is another significant determinant in dosimetry. The SPECT approach particularly in the presence of background activity, was more accurate in the phantom studies and resulted in larger estimated doses in the patient studies. Also, SPECT has the added advantage of providing an index of organ volume, which has to be balanced with the fact the planar is more rapid, and does not require special hardware. 24 references, 5 figures, 1 table

  9. Distribution of nuclear charge and angular momentum in chains 132-137, 99, and 102 of thermal neutron fission of 235U at various kinetic energies and charge states of the fragments

    International Nuclear Information System (INIS)

    Denschlag, H.O.; Braun, H.; Wolfsberg, K.

    1979-01-01

    The fission product yields of the members of the decay chains 132 to 137, 99, and 102 in 235 U(n/sub th/,f) were measured at various kinetic energies and ionic charge states of the fragments using the mass separator for unslowed fission products LOHENGRIN. The results are discussed with respect to four aspects: A preferential formation of neutron rich chain members found at high kinetic energy of the fragments is predominantly due to decreasing prompt neutron evaporation. A particularly large effect in chain 132 is attributed to the double shell closure in Sn-132. The persistence of an even-odd pairing effect in the yields throughout the range of kinetic energies studied leads to the conclusion that the high internal excitation energy of the fragments is tied up mainly in the form of collective energy (e.g., deformation energy) rather than single particle excitation. Generally, the yield distribution at constant kinetic energy is invariant with respect to the ionic charge state of the isotopes separated. Deviations from this behavior found in chains 99, 102, 133, and 136 are interpreted as being due to Auger events following a converted transition in the decay of ns-isomers taking place in the vacuum of the separator. A pronounced variation of the independent formation ratio of single isomeric states with the kinetic energy of the fragments is providing direct information on the controversial topic of the change of angular momentum of fission fragments as a function of deformation (scission distance). 34 references

  10. Mass and velocity of fragments from the reaction 17-115 MeV/u 40Ar + Cu, Ag and Au

    International Nuclear Information System (INIS)

    Colin, E.; Guinet, D.; Stern, M.

    1998-01-01

    Measurements are reported for fragment masses and velocities from the reactions 17-115 MeV/u 40 Ar + Cu, Ag and Au. High momentum and energy deposition are reported for selected events, even for higher incident energy. Further study is needed to understand their origin. (authors)

  11. Analysis of fragment size distributions in collisions of monocharged ions with the C{sub 60} molecule

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A; Moretto-Capelle, P; Bordenave-Montesquieu, D; Bordenave-Montesquieu, A [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

    2005-04-14

    Fragmentation of the C{sub 60} molecule is investigated using a multicorrelation technique. We first focus on the transition from asymmetrical dissociation (AD) to multifragmentation (MF). These processes are studied in collisions between H{sup +}{sub x}(x = 1-3) hydrogenic projectiles and C{sub 60} fullerene in the gas phase, in the 2-130 keV collisional energy range. A rather sharp transition from pure AD to predominant MF is observed when plotting the AD/(AD + MF) ratio against the average deposited energy E{sub dep}; it occurs in the 80-240 eV E{sub dep} range; this ratio is also found to be independent of the projectile species (scaling law). The evolution of the size distribution shape is also discussed and compared with other data available in the literature. A pure power law is never reached in the present experimental conditions. Finally, an event-by-event analysis of the fragmentation data is developed for the first time in the study of the C{sub 60} molecule fragmentation and discussed in terms of the predictions of the percolation model near a critical behaviour. Moments of order 2, 3 and 5 are determined for each correlation event. Moments of order 3 and 5 follow a linear behaviour when plotted against the moment of order 2, as predicted, and the exponent {tau} that is extracted takes a value near 2. The Campi scatter plot is also determined and discussed for total and multiplicity-selected events. Both slopes of the two branches in the Campi plots and {tau} value are near those that are expected in the percolation of a 2D lattice.

  12. New results from isochronous mass measurements of neutron-rich uranium fission fragments with the FRS-ESR-facility at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Knoebel, R.; Litvinov, Yu.A.; Weick, H.; Bosch, F.; Boutin, D.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S.A.; Matos, M.; Mazzocco, M.; Muenzenberg, G.; Nociforo, C.; Nolden, F.; Stadlmann, J.; Steck, M.; Winkler, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Diwisch, M. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Geissel, H.; Plass, W.R.; Scheidenberger, C.; Chen, L. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Patyk, Z. [National Centre for Nuclear Research - NCBJ Swierk, Warszawa (Poland); Sun, B. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Hausmann, M. [Michigan State University, East Lansing, MI (United States); Nakajima, S.; Suzuki, T.; Yamaguchi, T. [Saitama University, Department of Physics, Saitama (Japan); Ohtsubo, T. [Niigata University, Department of Physics, Niigata (Japan); Ozawa, A. [University of Tsukuba, Institute of Physics, Ibaraki (Japan); Walker, P.M. [University of Surrey, Department of Physics, Guildford (United Kingdom)

    2016-05-15

    Masses of uranium fission fragments have been measured with the FRagment Separator (FRS) combined with the Experimental Storage Ring (ESR) at GSI. A 410-415 MeV/u {sup 238}U projectile beam was fast extracted from the synchrotron SIS-18 with an average intensity of 10{sup 9}/spill. The projectiles were focused on a 1g/cm{sup 2} beryllium target at the entrance of the FRS to create neutron-rich isotopes via abrasion-fission. The fission fragments were spatially separated with the FRS and injected into the isochronous storage ring ESR for fast mass measurements without applying cooling. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B ρ-tagging at the high-resolution dispersive central focal plane of the FRS. The evaluation has been done for the combined data sets from both experiments with a new method of data analysis. The use of a correlation matrix has provided experimental mass values for 23 different neutron-rich isotopes for the first time and 6 masses with improved values. The new masses were obtained for nuclides in the element range from Se to Ce. The applied analysis has given access even to rare isotopes detected with an intensity of a few atoms per week. The novel data analysis and systematic error determination are described and the results are compared with extrapolations of experimental values and theoretical models. (orig.)

  13. Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

    CSIR Research Space (South Africa)

    Cho, Moses A

    2013-10-01

    Full Text Available the utility of new remote sensing tools to model the spatial distribution of leaf N concentration in a forested landscape undergoing deforestation in KwaZulu-Natal, South Africa. Leaf N was mapped using models developed from RapidEye imagery; a relatively new...

  14. Distribution of polyethylene wear particles and bone fragments in periprosthetic tissue around total hip joint replacements

    Czech Academy of Sciences Publication Activity Database

    Zolotarevova, E.; Entlicher, G.; Pavlova, Ewa; Šlouf, Miroslav; Pokorný, D.; Veselý, F.; Gallo, J.; Sosna, A.

    2010-01-01

    Roč. 6, č. 9 (2010), s. 3595-3600 ISSN 1742-7061 R&D Projects: GA MŠk 2B06096 Institutional research plan: CEZ:AV0Z40500505 Keywords : joint replacement * polyethylene * wear particles distribution Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.824, year: 2010

  15. Determination of the isotope distribution in 14C-labelled hydrocarbons by thermal fragmentation

    International Nuclear Information System (INIS)

    Kopinke, F.D.; Dermietzel, J.; Jockisch, W.; Raeuber, G.

    1986-01-01

    The gas chromatographic analysis of pyrolysis products of properly labelled hydrocarbons allows a definite and quantitative determination of the 14 C-distribution in those compounds. For this purpose a simple, fast, and versatilely applicable method has been developed and described

  16. Spatial distribution of bird communities in small forest fragments in central Europe in relation to distance to the forest edge, fragment size and type of forest

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, Jeňýk; Hošek, J.; Brabec, Marek; Kočvara, R.

    2017-01-01

    Roč. 401, OCT (2017), s. 255-263 ISSN 0378-1127 Institutional support: RVO:67179843 ; RVO:67985807 Keywords : Clearing * Dryocopus martius * Forest bird * Forest management * Generalized additive model * Habitat fragmentation Subject RIV: GK - Forestry; BB - Applied Statistics, Operational Research (UIVT-O) OBOR OECD: Forestry; Statistics and probability (UIVT-O) Impact factor: 3.064, year: 2016

  17. Mass size distribution of particle-bound water

    Science.gov (United States)

    Canepari, S.; Simonetti, G.; Perrino, C.

    2017-09-01

    The thermal-ramp Karl-Fisher method (tr-KF) for the determination of PM-bound water has been applied to size-segregated PM samples collected in areas subjected to different environmental conditions (protracted atmospheric stability, desert dust intrusion, urban atmosphere). This method, based on the use of a thermal ramp for the desorption of water from PM samples and the subsequent analysis by the coulometric KF technique, had been previously shown to differentiate water contributes retained with different strength and associated to different chemical components in the atmospheric aerosol. The application of the method to size-segregated samples has revealed that water showed a typical mass size distribution in each one of the three environmental situations that were taken into consideration. A very similar size distribution was shown by the chemical PM components that prevailed during each event: ammonium nitrate in the case of atmospheric stability, crustal species in the case of desert dust, road-dust components in the case of urban sites. The shape of the tr-KF curve varied according to the size of the collected particles. Considering the size ranges that better characterize the event (fine fraction for atmospheric stability, coarse fraction for dust intrusion, bi-modal distribution for urban dust), this shape is coherent with the typical tr-KF shape shown by water bound to the chemical species that predominate in the same PM size range (ammonium nitrate, crustal species, secondary/combustion species - road dust components).

  18. IDENTIFICATION OF THE MASS DISTRIBUTIONS OF THE MILK FAT PHASE USING UNIVERSAL PEARSON DISTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    A. A. Khvostov

    2015-01-01

    Full Text Available In this paper we consider the problem of approximating the experimental values of the coefficient of attenuation of ultrasonic oscillations and the mass distribution of the fat globules in the milk and milk products. The analysis of experimental data in terms of the choice of the method of approximation was done. A approximating dependence is based on the solution of Pearson differential equations. The advantages of the proposed method for the type of approximation of the experimental data obtained. An algorithm for constructing a mathematical model describing the relaxation spectrum and mass distribution of the fat globules in the milk and milk products was implemented. As a result, a family of Pearson approximation curves of the experimental data shows the ability to qualitatively correctly describe the change in the distribution of the fat phase in the process of homogenization. It estimates the error of approximating dependence, which amounted to 18 %. It is shown that during of the process of homogenization of dairy products changes shape of the curve describing the distribution of the fat globules, in view of the fact that there is a local extremum, caused by the presence of the non-homogenized fat globules. The accuracy of the selected mathematical model is significantly reduced. At the same time, it loses its physical meaning and its parameters. To address the identified deviations in the proposed mass distribution of fat globules as a function with two modes. It is proved that the complexity of the model is not only doubles the number of its parameters, but also complicates the interpretation of measurement results in a control system, and makes it difficult to analyze the obtained parameters of approximation by decision-maker. As a result of approximation of experimental data suggested to use statistical moments of the distribution for problem decision.

  19. Multiple and sequential data acquisition method: an improved method for fragmentation and detection of cross-linked peptides on a hybrid linear trap quadrupole Orbitrap Velos mass spectrometer.

    Science.gov (United States)

    Rudashevskaya, Elena L; Breitwieser, Florian P; Huber, Marie L; Colinge, Jacques; Müller, André C; Bennett, Keiryn L

    2013-02-05

    The identification and validation of cross-linked peptides by mass spectrometry remains a daunting challenge for protein-protein cross-linking approaches when investigating protein interactions. This includes the fragmentation of cross-linked peptides in the mass spectrometer per se and following database searching, the matching of the molecular masses of the fragment ions to the correct cross-linked peptides. The hybrid linear trap quadrupole (LTQ) Orbitrap Velos combines the speed of the tandem mass spectrometry (MS/MS) duty circle with high mass accuracy, and these features were utilized in the current study to substantially improve the confidence in the identification of cross-linked peptides. An MS/MS method termed multiple and sequential data acquisition method (MSDAM) was developed. Preliminary optimization of the MS/MS settings was performed with a synthetic peptide (TP1) cross-linked with bis[sulfosuccinimidyl] suberate (BS(3)). On the basis of these results, MSDAM was created and assessed on the BS(3)-cross-linked bovine serum albumin (BSA) homodimer. MSDAM applies a series of multiple sequential fragmentation events with a range of different normalized collision energies (NCE) to the same precursor ion. The combination of a series of NCE enabled a considerable improvement in the quality of the fragmentation spectra for cross-linked peptides, and ultimately aided in the identification of the sequences of the cross-linked peptides. Concurrently, MSDAM provides confirmatory evidence from the formation of reporter ions fragments, which reduces the false positive rate of incorrectly assigned cross-linked peptides.

  20. A Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry (LC-Q-TOF MS) Study for Analyzing 35 Corticosteroid Compounds: Elucidation of MS/MS Fragmentation Pathways

    International Nuclear Information System (INIS)

    Noh, Eunyoung; Yoon, Chang-Yong; Lee, Ji Hyun; Baek, Sun-Young; Do, Jung-Ah; Lee, Jung-min; Oh, Han Bin

    2016-01-01

    Corticosteroids have been often found to be added to a dietary supplement for the purpose of illegally improving the effect of their products. Thus, it is imperative to develop or improve a method that enables one to rapidly and reliably analyze corticosteroids in health or dietary supplements, for the safety management purpose. In the present study, results from liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) experiments for the selected 35 corticosteroid compounds are presented, which can be useful for the qualitative screening of corticosteroids in health or dietary supplements. Specifically, retention times, accurate mass data of the protonated steroids, m/z values of major fragment ions are given for the 35 corticosteroids. Further, fragmentation pathways for the selected steroids are also suggested. Based on the suggested fragmentation pathways, it was shown that an unknown steroid compound can be readily identified using the knowledge of a group of unique and specific common skeletal fragments. The high selectivity and sensitivity of the LC-Q-TOF-MS/MS results combined with the knowledge of the fragmentation pathways can offer a new opportunity for rapid and accurate screening of corticosteroids, thus preventing health-related incidents involving adulterated products and clamping down on illegally circulated health products.

  1. A Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry (LC-Q-TOF MS) Study for Analyzing 35 Corticosteroid Compounds: Elucidation of MS/MS Fragmentation Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Eunyoung; Yoon, Chang-Yong; Lee, Ji Hyun; Baek, Sun-Young; Do, Jung-Ah [Ministry of Food and Drug Safety, Cheongju (Korea, Republic of); Lee, Jung-min; Oh, Han Bin [Sogang University, Seoul (Korea, Republic of)

    2016-07-15

    Corticosteroids have been often found to be added to a dietary supplement for the purpose of illegally improving the effect of their products. Thus, it is imperative to develop or improve a method that enables one to rapidly and reliably analyze corticosteroids in health or dietary supplements, for the safety management purpose. In the present study, results from liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) experiments for the selected 35 corticosteroid compounds are presented, which can be useful for the qualitative screening of corticosteroids in health or dietary supplements. Specifically, retention times, accurate mass data of the protonated steroids, m/z values of major fragment ions are given for the 35 corticosteroids. Further, fragmentation pathways for the selected steroids are also suggested. Based on the suggested fragmentation pathways, it was shown that an unknown steroid compound can be readily identified using the knowledge of a group of unique and specific common skeletal fragments. The high selectivity and sensitivity of the LC-Q-TOF-MS/MS results combined with the knowledge of the fragmentation pathways can offer a new opportunity for rapid and accurate screening of corticosteroids, thus preventing health-related incidents involving adulterated products and clamping down on illegally circulated health products.

  2. Energy distributions of H+ fragments ejected by fast proton and electron projectiles in collision with H2O molecules

    International Nuclear Information System (INIS)

    Barros, A. L. F. de; Lecointre, J.; Luna, H.; Montenegro, E. C.; Shah, M. B.

    2009-01-01

    Experimental measurements of the kinetic energy distribution spectra of H + fragment ions released during radiolysis of water molecules in collision with 20, 50, and 100 keV proton projectiles and 35, 200, 400, and 1000 eV electron projectiles are reported using a pulsed beam and drift tube time-of-flight based velocity measuring technique. The spectra show that H + fragments carrying a substantial amount of energy are released, some having energies well in excess of 20 eV. The majority of the ions lie within the 0-5 eV energy range with the proton spectra showing an almost constant profile between 1.5 and 5 eV and, below this, increasing gradually with decreasing ejection energy up to the near zero energy value while the electron spectra, in contrast, show a broad maximum between 1 and 3 eV and a pronounced dip around 0.25 eV. Beyond 5 eV, both projectile spectra show a decreasing profile with the electron spectra decreasing far more rapidly than the proton spectra. Our measured spectra thus indicate that major differences are present in the collision dynamics between the proton and the electron projectiles interacting with gas phase water molecules.

  3. Differentiating chondroitin sulfate glycosaminoglycans using collision-induced dissociation; uronic acid cross-ring diagnostic fragments in a single stage of tandem mass spectrometry.

    Science.gov (United States)

    Kailemia, Muchena J; Patel, Anish B; Johnson, Dane T; Li, Lingyun; Linhardt, Robert J; Amster, I Jonathan

    2015-01-01

    The stereochemistry of the hexuronic acid residues of the structure of glycosaminoglycans (GAGs) is a key feature that affects their interactions with proteins and other biological functions. Electron based tandem mass spectrometry methods, in particular electron detachment dissociation (EDD), have been able to distinguish glucuronic acid (GlcA) from iduronic acid (IdoA) residues in some heparan sulfate tetrasaccharides by producing epimer-specific fragments. Similarly, the relative abundance of glycosidic fragment ions produced by collision-induced dissociation (CID) or EDD has been shown to correlate with the type of hexuronic acid present in chondroitin sulfate GAGs. The present work examines the effect of charge state and degree of sodium cationization on the CID fragmentation products that can be used to distinguish GlcA and IdoA containing chondroitin sulfate A and dermatan sulfate chains. The cross-ring fragments (2,4)A(n) and (0,2)X(n) formed within the hexuronic acid residues are highly preferential for chains containing GlcA, distinguishing it from IdoA. The diagnostic capability of the fragments requires the selection of a molecular ion and fragment ions with specific ionization characteristics, namely charge state and number of ionizable protons. The ions with the appropriate characteristics display diagnostic properties for all the chondroitin sulfate and dermatan sulfate chains (degree of polymerization of 4-10) studied.

  4. Radial distributions of surface mass density and mass-to-luminosity ratio in spiral galaxies

    Science.gov (United States)

    Sofue, Yoshiaki

    2018-03-01

    We present radial profiles of the surface mass density (SMD) in spiral galaxies directly calculated using rotation curves of two approximations of flat-disk (SMD-F) and spherical mass distribution (SMD-S). The SMDs are combined with surface brightness using photometric data to derive radial variations of the mass-to-luminosity ratio (ML). It is found that the ML generally has a central peak or a plateau, and decreases to a local minimum at R ˜ 0.1-0.2 h, where R is the radius and h is the scale radius of optical disk. The ML, then, increases rapidly until ˜0.5 h, and is followed by gradual rise till ˜2 h, remaining at around ˜2 [M_{⊙} L^{-1}_{⊙}] in the w1 band (infrared λ3.4 μm) and ˜ 10 [M_⊙ L_⊙ ^{-1}] in the r band (λ6200-7500 Å). Beyond this radius, the ML increases steeply with approaching the observed edges at R ˜ 5 h, attaining to as high values as ˜20 in w1 and ˜ 10^2 [M_⊙ L_⊙ ^{-1}] in the r band, which are indicative of dominant dark matter. The general properties of the ML distributions will be useful for constraining cosmological formation models of spiral galaxies.

  5. Fission cross section and fission fragment angular distribution for oriented nucleus fission by intermediate energy neutrons (epsilon < or approximately 1 Mev)

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1985-01-01

    General analysis is conducted, and formulae for fission cross section and angular distribution of fission fragments of oriented nuclei by fast neutrons are presented. Geometrical coefficients making up the formulae permitting to carry out calculations for target nuclei with spins I=3/2, 5/2, 7/2 at interaction energies epsilon < or approximately 1 MeV are tabulated. Results of demonstrative calculation of fission fragment angular distribution of oriented sup(235)U nuclei by 0.1 <= epsilon <= 1.0 MeV neutrons reveal that angular distribution weakly depends on the set of permeability factors of neutron waves applied in the calculations

  6. Charge and mass distribution in 20Ne induced fission of 181Ta

    International Nuclear Information System (INIS)

    Tripathi, R.; Sudarshan, K.; Goswami, A.; Reddy, A.V.R.; Guin, R.

    2005-01-01

    Charge and mass distribution studies have been carried out at E lab =180 MeV in 20 Ne induced fission of 181 Ta. The mass distribution has been found to be symmetric. The width of the mass distribution has been theoretically calculated using the random neck rupture of Brosa et al. A good agreement between the calculated and experimental mass distribution has been observed. (author)

  7. Angular distribution of fragments from neutron-induced fission of {sup 238}U in the intermediate energy region

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Magnus

    2004-06-01

    Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of {sup 238}U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of {sup 238}U.

  8. Imaging of mass distribution in paper by electrography technique, (3)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Baba, Susumu; Luner, P.

    1991-01-01

    Characteristics of photographic films and a TV monitor system as electron beam detectors were studied. A photographic film with thin emulsion layer showed a peak in the basis weight calibration curve because of its limited absorption of electron energy. On the other hand, a photographic film with thick emulsion layer showed no peak and provided wide measurable basis weight range. However, films with thick emulsion layer were found unsuitable for practical use since it requires very long development time. Real-time mass distribution image of a paper sample were obtained with a TV monitor system for transmission electron microscope combined with an image analyzer. The system can image the sample of 11x9 mm with spatial resolution of 20 μm at different electron accelerating voltages. The TV monitor system gave no peak in the basis weight calibration curve and provided wide measurable basis weight range. (author)

  9. Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy.

    Science.gov (United States)

    Juan, Hsu-Cheng; Lin, Hung-Yu; Chou, Yii-Her; Yang, Yi-Hsin; Shih, Paul Ming-Chen; Chuang, Shu-Mien; Shen, Jung-Tsung; Juan, Yung-Shun

    2012-08-01

    To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. • Unenhanced CT is now widely used to assess ureteric calculi. • The same CT protocol can provide measurements of abdominal fat distribution. • Ureteric calculi are usually treated by shock wave lithotripsy (SWL). • Greater intra-abdominal fat stores are generally associated with poorer SWL results.

  10. Effect of land cover, habitat fragmentation and ant colonies on the distribution and abundance of shrews in southern California

    Science.gov (United States)

    Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

    2001-01-01

    Because effects of habitat fragmentation and anthropogenic disturbance on native animals have been relatively little studied in arid areas and in insectivores, we investigated the roles of different land covers, habitat fragmentation and ant colonies on the distribution and abundance of shrews, Notiosorex crawfordi and Sorex ornatus, in southern California.Notiosorex crawfordi was the numerically dominant species (trap-success rate 0·52) occurring in 21 of the 22 study sites in 85% of the 286 pitfall arrays used in this study.Sorex ornatus was captured in 14 of the sites, in 52% of the arrays with a total trap-success rate of 0·2. Neither of the species was found in one of the sites.The population dynamics of the two shrew species were relatively synchronous during the 4–5-year study; the peak densities usually occurred during the spring. Precipitation had a significant positive effect, and maximum temperature a significant negative effect on the trap-success rate of S. ornatus.Occurrence and abundance of shrews varied significantly between sites and years but the size of the landscape or the study site had no effect on the abundance of shrews. The amount of urban edge had no significant effect on the captures of shrews but increased edge allows invasion of the Argentine ants, which had a highly significant negative impact on the abundance of N. crawfordi.At the trap array level, the percentage of coastal sage scrub flora had a significant positive, and the percentage of other flora had a significant negative effect on the abundance of N. crawfordi. The mean canopy height and the abundance of N. crawfordi had a significant positive effect on the occurrence of S. ornatus.Our study suggests that the loss of native coastal sage scrub flora and increasing presence of Argentine ant colonies may significantly effect the distribution and abundance of N. crawfordi. The very low overall population densities of both shrew species in most study sites make both species

  11. Mass distribution and evolutionary scheme for central stars of planetary nebulae

    International Nuclear Information System (INIS)

    Heap, S.R.; Augensen, H.J.; Widener Univ., Chester, PA)

    1987-01-01

    IUE data and a distance measuring method that considered central stars in optically thick nebulae were used to examine mass distributions of planetary nebulae. Other data such as spectral type, spatial and kinematic characteristics, etc., were studied to derive relationships between population type and mass distribution. A central star mass range of at least 0.55 solar mass was obtained. Stars with masses of at least 0.64 solar mass, concentrated in the galactic disk, originated from 1.5 solar mass stars. Low mass nuclei originated in old disk or halo populations and evolved from 1.0 solar mass objects. A mass-loss parameter value of 1/3 was calculated for red giants, implying that white dwarfs evolve from stars of under 5 solar masses. Mass distributions around planetary nuclei were concluded to follow patterns associated with the individual mass. 75 references

  12. Mass Distribution and Gravitational Potential of the Milky Way

    Directory of Open Access Journals (Sweden)

    Ninković Slobodan

    2017-04-01

    Full Text Available Models of mass distribution in the Milky Way are discussed where those yielding the potential analytically are preferred. It is noted that there are three main contributors to the Milky Way potential: bulge, disc and dark halo. In the case of the disc the Miyamoto-Nagai formula, as simple enough, has shown as a very good solution, but it has not been able to satisfy all requirements. Therefore, improvements, such as adding new terms or combining several Miyamoto-Nagai terms, have been attempted. Unlike the disc, in studying the bulge and dark halo the flattening is usually neglected, which offers the possibility of obtaining an exact solution of the Poisson equation. It is emphasized that the Hernquist formula, used very often for the bulge potential, is a special case of another formula and the properties of that formula are analysed. In the case of the dark halo, the slopes of its cumulative mass for the inner and outer parts are explained through a new formalism presented here for the first time.

  13. Yields of correlated fragment pairs and neutron multiplicity in spontaneous fission of {sup 242}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Veselsky, M.; Kliman, J.; Morhaccaron, M. [Institute of Physics of Slovak Academy of Sciences, Dubravska 9, 84228 Bratislava (Slovakia); Ramayya, A.V.; Kormicki, J.; Daniel, A.V. [Physics Department, Vanderbilt University, Nashville (United States)] Rasmussen, J.O. [Lawrence Berkeley National Laboratory, Berkeley (United States)] Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore (United States); Daniel, A.V.; Popeko, G.S.; Oganessian, Yu. Ts. [Joint Institute for Nuclear Research, Dubna (Russia)] Greiner, W. [Institut fur Theoretische Physik, J. W. Goethe Universitaet, Frankfurt a. M. (Germany); Aryaeinejad, R. [Idaho National Engineering Laboratory, Idaho Falls (United States)

    1998-10-01

    Yields of correlated fragment pairs were obtained in spontaneous fission of {sup 242}Pu. Charge, mass and neutron multiplicity distributions of fragment pairs were determined and compared to available data. The yield of cold fission without neutron emission was determined to about 10{percent} for the set of observed correlated fragment pairs. {copyright} {ital 1998 American Institute of Physics.}

  14. Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy

    International Nuclear Information System (INIS)

    Juan, Hsu-Cheng; Chou, Yii-Her; Lin, Hung-Yu; Yang, Yi-Hsin; Shih, Paul Ming-Chen; Chuang, Shu-Mien; Shen, Jung-Tsung; Juan, Yung-Shun

    2012-01-01

    To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. (orig.)

  15. Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy

    Energy Technology Data Exchange (ETDEWEB)

    Juan, Hsu-Cheng; Chou, Yii-Her [Kaohsiung Medical University Hospital, Department of Urology, Kaohsiung (China); Lin, Hung-Yu [Kaohsiung Medical University, Graduate Institute of Medicine, Kaohsiung (China); E-Da Hospital/ I-Shou University, Department of Urology, Kaohsiung (China); Yang, Yi-Hsin [Kaohsiung Medical University, Institute of Oral Health Sciences, Kaohsiung (China); Shih, Paul Ming-Chen [Kaohsiung Municipal Hsiao-Kang Hospital, Department of Radiology, Kaohsiung (China); Kaohsiung Medical University, Department of Radiology, Kaohsiung (China); Chuang, Shu-Mien [Yuh-Ing Junior College of Health Care and Management, Kaohsiung (China); Shen, Jung-Tsung [Kaohsiung Municipal Hsiao-Kang Hospital, Department of Urology, Kaohsiung (China); Juan, Yung-Shun [Kaohsiung Medical University Hospital, Department of Urology, Kaohsiung (China); Kaohsiung Medical University, Graduate Institute of Medicine, Kaohsiung (China); Kaohsiung Medical University, Department of Urology, Faculty of Medicine, Kaohsiung (China)

    2012-08-15

    To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. (orig.)

  16. Towards a dynamical description of intermediate mass fragment formation in heavy-ion collisions at some tens of MeV/A

    International Nuclear Information System (INIS)

    Suraud, E.

    1990-01-01

    We briefly remind the possible dynamical scenario of fragments formation in central heavy-ion collisions at some tens of MeV/A. We discuss how present day dynamical models can describe fragment formation. We show that particle methods provide a reasonable solution of Boltzman-like equations. We next turn to the Boltzmann-Langevin formalism which gives a well defined framework for the understanding of Intermediate Mass Fragments formation. We present a first numerical solution of this equation and show the importance of fluctuations in the dynamics of the collision. We finally apply the formalism to the onset of multifragmentation in the 40 Ca + 40 Ca system between 20 and 60 MeV/A beam energy

  17. Fragment production in 12-GeV proton-induced reactions

    International Nuclear Information System (INIS)

    Hirata, Yuichi; Ohnishi, Akira; Ohtsuka, Naohiko; Nara, Yasushi; Niida, Koji; Chiba, Satoshi; Takada, Hiroshi

    2000-01-01

    We study mass and angular distribution of Intermediate Mass Fragment (IMF) produced from p(12 GeV)+ 197 Au reaction by using JAM cascade model combined with percolation model. Although the mass distribution of IMF is well reproduced, the experimentally observed sideward peak of IMF angular distribution is not explained within present JAM + percolation model. (author)

  18. Binary fragmentation based studies for the near super-heavy compound nucleus {sup 256}Rf

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Meenu; Behera, B.R.; Mahajan, Ruchi; Kaur, Gurpreet; Sharma, Priya; Kapoor, Kushal; Rani, Kavita [Panjab University, Department of Physics, Chandigarh (India); Saneesh, N.; Dubey, R.; Yadav, A.; Sugathan, P.; Jhingan, A.; Chatterjee, A.; Chatterjee, M.B. [Inter University Accelerator Centre, New Delhi (India); Kumar, Neeraj; Mandal, S. [University of Delhi, Department of Physics and Astrophysics, Delhi (India); Kumar, S. [Andhra University, Department of Nuclear Physics, Visakhapatnam (India); Saxena, A.; Kailas, S. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Pal, Santanu [CS, Kolkata (India); Nasirov, Avazbek [JINR, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation); National University, Department of Physics, Tashkent (Uzbekistan); Kayumov, Bakhodir [National University, Department of Physics, Tashkent (Uzbekistan)

    2017-06-15

    Binary fragmentation of the near super-heavy compound nucleus {sup 256}Rf has been studied through the reaction {sup 48}Ti + {sup 208}Pb at a bombarding energy well above the Coulomb barrier. For a better understanding of its reaction dynamics, the mass distribution, mass-energy distribution and mass-angle distribution of the fission fragments produced from {sup 256}Rf have been investigated thoroughly. The masses and kinetic energies of the fission fragments were reconstructed event-by-event from their measured velocities and emission angles. From the mass-energy analysis, a sizeable contribution from the asymmetric fission was observed on the edges of symmetric mass distribution. Evidence of asymmetric fission was also clued from the observed correlation between the masses and emission angles of the fission fragments. Contribution of the quasi-fission products has also been estimated by performing the theoretical dinuclear system calculations. (orig.)

  19. An (e, 2e + ion) study of low-energy electron-impact ionization and fragmentation of tetrahydrofuran with high mass and energy resolutions

    Science.gov (United States)

    Ren, Xueguang; Pflüger, Thomas; Weyland, Marvin; Baek, Woon Yoon; Rabus, Hans; Ullrich, Joachim; Dorn, Alexander

    2014-10-01

    We study the low-energy (E0 = 26 eV) electron-impact induced ionization and fragmentation of tetrahydrofuran using a reaction microscope. All three final-state charged particles, i.e., two outgoing electrons and one fragment ion, are detected in triple coincidence such that the momentum vectors and, consequently, the kinetic energies for charged reaction products are determined. The ionic fragments are clearly identified in the experiment with a mass resolution of 1 amu. The fragmentation pathways of tetrahydrofuran are investigated by measuring the ion kinetic energy spectra and the binding energy spectra where an energy resolution of 1.5 eV has been achieved using the recently developed photoemission electron source. Here, we will discuss the fragmentation reactions for the cations C4H8O+, C4H7O+, C2H3O+, C3H_6^+, C3H_5^+, C3H_3^+, CH3O+, CHO+, and C2H_3^+.

  20. Modelling the distribution of the invasive Roesel’s bush-cricket (Metrioptera roeselii in a fragmented landscape

    Directory of Open Access Journals (Sweden)

    Sonja Preuss

    2011-11-01

    Full Text Available The development of conservation strategies to mitigate the impact of invasive species requires knowledge of the species ecology and distribution. This is, however, often lacking as collecting biological data may be both time-consuming and resource intensive. Species distribution models can offer a solution to this dilemma by analysing the species-environment relationship with help of Geographic information systems (GIS. In this study, we model the distribution of the non-native bush-cricket Metrioptera roeselii in the agricultural landscape in mid-Sweden where the species has been rapidly expanding in its range since the 1990s. We extract ecologically relevant landscape variables from Swedish CORINE land-cover maps and use species presence-absence data from large-scale surveys to construct a species distribution model (SDM. The aim of the study is to increase the knowledge of the species range expansion pattern by examining how its distribution is affected by landscape composition and structure, and to evaluate SDM performance at two different spatial scales. We found that models including data on a scale of 1 × 1 km were able to explain more of the variation in species distribution than those on the local scale (10 m buffer on each side of surveyed road. The amount of grassland in the landscape, estimated from the area of arable land, pasture and rural settlements, was a good predictor of the presence of the species on both scales. The measurements of landscape structure – linear elements and fragmentation - gave ambivalent results which differed from previous small scaled studies on species dispersal behaviour and occupancy patterns. The models had good predictive ability and showed that areas dominated by agricultural fields and their associated grassland edges have a high probability being colonised by the species. Our study identified important landscape variables that explain the distribution of M. roeselii in Mid-Sweden that may also

  1. Evolution of size distribution, optical properties, and structure of Si nanoparticles obtained by laser-assisted fragmentation

    Science.gov (United States)

    Plautz, G. L.; Graff, I. L.; Schreiner, W. H.; Bezerra, A. G.

    2017-05-01

    We investigate the physical properties of Si-based nanoparticles produced by an environment-friendly three-step method relying on: (1) laser ablation of a solid target immersed in water, (2) centrifugation and separation, and (3) laser-assisted fragmentation. The evolution of size distribution is followed after each step by means of dynamic light scattering (DLS) measurements and crosschecked by transmission electron microscopy (TEM). The as-ablated colloidal suspension of Si nanoparticles presents a large size distribution, ranging from a few to hundreds of nanometers. Centrifugation drives the very large particles to the bottom eliminating them from the remaining suspension. Subsequent irradiation of height-separated suspensions with a second high-fluence (40 mJ/pulse) Nd:YAG laser operating at the fourth harmonic (λ =266 nm) leads to size reduction and ultra-small nanoparticles are obtainable depending on the starting size. Si nanoparticles as small as 1.5 nm with low dispersion (± 0.7 nm) are observed for the uppermost part after irradiation. These nanoparticles present a strong blue photoluminescence that remains stable for at least 8 weeks. Optical absorption (UV-Vis) measurements demonstrate an optical gap widening as a consequence of size decrease. Raman spectra present features related to pure silicon and silicon oxides for the irradiated sample. Interestingly, a defect band associated with silicon oxide is also identified, indicating the possible formation of defect states, which, in turn, supports the idea that the blue photoluminescence has its origin in defects.

  2. Metabolic behavior and distribution of the synthetic nonapeptide fragment 163-171 of human IL-1 beta.

    Science.gov (United States)

    Pessina, G P; Bocci, V; Nicoletti, C; Becherucci, C; Presentini, R; Parente, L; Villa, L; Tagliabue, A; Boraschi, D

    1990-01-01

    The pharmacokinetic parameters and distribution of the adjuvant synthetic nonapeptide VQGEESNDK, corresponding to the fragment in position 163-171 in human IL-1, were analyzed after administration to rabbit through different routes. The radiolabeled peptide did not bind to plasma proteins and, when inoculated i.v., it disappeared very rapidly from the circulation, with a t1/2 alpha of 1 min and a t 1/2 beta of 166 min. Upon administration through i.m., s.c. and oral route, the Cmax was reached between 30 and 90 min after inoculum and ranged between 7 and 4% of the administered dose. Organ distribution showed that most of the radioactivity was concentrated in kidneys and excreted in urine. From Sephadex G-10 chromatography, about 60% of the peptide recovered in the urine 4h after i.v. inoculum was intact, whereas it was more than 85% degraded when administered by other routes. The amount of intact peptide recovered in the urine correlated with the biological effectiveness through different routes, suggesting that the adjuvant effect in vivo is exerted by the intact peptide, rather than by its metabolites.

  3. Investigation of prompt gamma-ray yields as a function of mass and charge of 236U fission fragments

    International Nuclear Information System (INIS)

    Bogdzel', A.A.; Gundorin, N.A.; Duka-Zojomi, A.; Kliman, Ya.; Krishtiak, J.

    1987-01-01

    New experimental results determining yields of the prompt gamma-rays from the excited states decay of fission fragments are presented. 80 gamma-transitions were observed in 51 fission fragments. The measurements were performed by Ge(Li)-spectrometry in coincidence with fast ionization chamber (10g 235 U). The beam of the resonance neutrons with energy range from 0.7 to 36 eV was used

  4. THE EFFECTS OF VIEWING ANGLE ON THE MASS DISTRIBUTION OF EXOPLANETS

    International Nuclear Information System (INIS)

    Lopez, S.; Jenkins, J. S.

    2012-01-01

    We present a mathematical method to statistically decouple the effects of unknown inclination angles on the mass distribution of exoplanets that have been discovered using radial-velocity (RV) techniques. The method is based on the distribution of the product of two random variables. Thus, if one assumes a true mass distribution, the method makes it possible to recover the observed distribution. We compare our prediction with available RV data. Assuming that the true mass function is described by a power law, the minimum mass function that we recover proves a good fit to the observed distribution at both mass ends. In particular, it provides an alternative explanation for the observed low-mass decline, usually explained as sample incompleteness. In addition, the peak observed near the low-mass end arises naturally in the predicted distribution as a consequence of imposing a low-mass cutoff in the true distribution. If the low-mass bins below 0.02 M J are complete, then the mass distribution in this regime is heavily affected by the small fraction of lowly inclined interlopers that are actually more massive companions. Finally, we also present evidence that the exoplanet mass distribution changes form toward low mass, implying that a single power law may not adequately describe the sample population.

  5. Large armored bridging over fractured vertebra with intraspinal tumor mimicking bony mass caused by migrated fragments of burst cervical vertebra presenting with severe cervical myelopathy

    Directory of Open Access Journals (Sweden)

    Satyarthee Guru Dutta

    2017-06-01

    Full Text Available Vertebral body may get displaced anterior or posteror with elements of rotation. However, burst cervical spine vertebral fracture may migrate anteriorly and posteriorly simultaneously. However anterior displaced fragment forming armor like mass is very rare. Similarly, the posteriorly propelled fragments migrating caudally and posterolaterally producing a large osseous mass inside spinal canal mimicking bony tumour causing severe cervical canal stenosis and presenting with marked myelopathy is extremely rare. To the best knowledge of authors, association of such traumatic dual pathology represents first of its kind in western literature, who was neglected early medical advice and presenting with marked compressive cervical myelopathy. She underwent successful surgical decompression with gradual recovery of spastic limb weakness and recovery of sensation. Authors also highlights the importance of early resuscitation and adequate maintainace of mean arterial pressure following acute spinal cord injury. Pertinent literature is briefly reviewed.

  6. Fragmentation in DNA double-strand breaks

    International Nuclear Information System (INIS)

    Wei Zhiyong; Suzhou Univ., Suzhou; Zhang Lihui; Li Ming; Fan Wo; Xu Yujie

    2005-01-01

    DNA double strand breaks are important lesions induced by irradiations. Random breakage model or quantification supported by this concept is suitable to analyze DNA double strand break data induced by low LET radiation, but deviation from random breakage model is more evident in high LET radiation data analysis. In this work we develop a new method, statistical fragmentation model, to analyze the fragmentation process of DNA double strand breaks. After charged particles enter the biological cell, they produce ionizations along their tracks, and transfer their energies to the cells and break the cellular DNA strands into fragments. The probable distribution of the fragments is obtained under the condition in which the entropy is maximum. Under the approximation E≅E 0 + E 1 l + E 2 l 2 , the distribution functions are obtained as exp(αl + βl 2 ). There are two components, the one proportional to exp(βl 2 ), mainly contributes to the low mass fragment yields, the other component, proportional to exp(αl), decreases slowly as the mass of the fragments increases. Numerical solution of the constraint equations provides parameters α and β. Experimental data, especially when the energy deposition is higher, support the statistical fragmentation model. (authors)

  7. [Edge effect on lichen's distribution and chlorophyll content, in fragments of Polylepis quadrijuga (Rosaceae) in Páramo de la Rusia (Boyacá-Colombia)].

    Science.gov (United States)

    Pulido Herrera, Karen; Ramos Montaño, Carolina

    2016-12-01

    The ecosystems fragmentation is one of the anthropic phenomena with highest impact at global level and the edge effect causes that only the fragments interior conserve their original biotic and abiotic characteristics. Lichens are organisms especially susceptible to environmental variability, what could be useful for bio-indication of edge effect. In this work, we evaluated the edge effect in two fragments of Polylepis quadrijuga in the Páramo de la Rusia (Boyacá-Colombia) to determine if there is an edge effect on distribution of lichens associated to P. quadrijuga and their chlorophyll content. We used three transects of 70 m across the matrix-edge-interior gradient in each fragment. We chose nine phorophytes per transect to measure the environmental variables: photosynthetically active radiation, relative humidity and air temperature, and the biological variables: richness and cover per species. Besides, we employed the species that were present in all the three zones of the gradient to quantify the content of chlorophylls a and b, and determine if there are changes in the ratio of chlorophylls a/b that could suggest physiological plasticity as a response to the edge effect. Our results showed that fragment 2 had a higher edge exposition because of its high relation perimeter/area, allowing to an environmental homogenization and lose of biodiversity in relation with fragment 1. Overall, we found 55 differentially distributed species in relation with the fragments and the matrix-edge-interior gradient. The interior of fragment 1 was the most conserved zone, harboring a composition different in more than 40 % to the composition of any other zone. We classified the lichens according with their habits: gelatinous, fruticose, crusty or foliose, but we did not find any relationship between the habit distribution and the edge effect. Six species of wide distribution showed changes in the chlorophyll content along the matrix-edge-interior gradient, what is an evidence

  8. Mass-storage management for distributed image/video archives

    Science.gov (United States)

    Franchi, Santina; Guarda, Roberto; Prampolini, Franco

    1993-04-01

    The realization of image/video database requires a specific design for both database structures and mass storage management. This issue has addressed the project of the digital image/video database system that has been designed at IBM SEMEA Scientific & Technical Solution Center. Proper database structures have been defined to catalog image/video coding technique with the related parameters, and the description of image/video contents. User workstations and servers are distributed along a local area network. Image/video files are not managed directly by the DBMS server. Because of their wide size, they are stored outside the database on network devices. The database contains the pointers to the image/video files and the description of the storage devices. The system can use different kinds of storage media, organized in a hierarchical structure. Three levels of functions are available to manage the storage resources. The functions of the lower level provide media management. They allow it to catalog devices and to modify device status and device network location. The medium level manages image/video files on a physical basis. It manages file migration between high capacity media and low access time media. The functions of the upper level work on image/video file on a logical basis, as they archive, move and copy image/video data selected by user defined queries. These functions are used to support the implementation of a storage management strategy. The database information about characteristics of both storage devices and coding techniques are used by the third level functions to fit delivery/visualization requirements and to reduce archiving costs.

  9. On the nuclear fragmentation mechanisms in nuclear collisions at intermediate and high energies

    International Nuclear Information System (INIS)

    Jipa, Al.; Besliu, C.; Felea, D.; Iliescu, B.; Ristea, O.; Ristea, M.; Calin, C.; Horbuniev, A.; Arsene, I.; Esanu, T.; Ochesanu, S.; Caramarcu, C.; Bordeianu, C.; Rosu, I.; Grossu, V.; Zgura, I.S.; Stan, E.; Mitu, C.; Potlog, M.; Cherciu, M.; Stefan, I.

    2004-01-01

    The nuclear fragmentation mechanisms can be discussed taking into account different scales. These scales are related to the fragment sizes. Taking into account the possible different fragmentation mechanisms of the nuclei at the same incident energy an analysis of the experimental results obtained in different experiments performed at the JINR Dubna (Russia), KEK Tsukuba (Japan), GSI Darmstadt (Germany) is done. Results on apparent temperatures, angular distributions, fragment momentum spectra, multiplicities of the intermediate mass fragments are used to analyse the competition between two possible nuclear fragmentation mechanisms, namely: a sudden fragmentation by explosive mechanisms, like shock waves, and a slow fragmentation by the 'fission' of the spectator regions, mainly, because of the interactions with the particles or fragments emitted from the participant region at transverse angles on the incident nucleus, in CMS.Some connections with chaos dynamics and fractal structure of the fragmentation patterns are included. (authors)

  10. Dynamic anthropogenic edge effects on the distribution and diversity of fungi in fragmented old-growth forests.

    Science.gov (United States)

    Ruete, Alejandro; Snäll, Tord; Jönsson, Mari

    2016-07-01

    Diversity patterns and dynamics at forest edges are not well understood. We disentangle the relative importance of edge-effect variables on spatio-temporal patterns in species richness and occupancy of deadwood-dwelling fungi in fragmented old-growth forests. We related richness and log occupancy by 10 old-growth forest indicator fungi and by two common fungi to log conditions in natural and anthropogenic edge habitats of 31 old-growth Picea abies forest stands in central Sweden. We compared edge-to-interior gradients (100 m) to the forest interior (beyond 100 m), and we analyzed stand-level changes after 10 yr. Both richness and occupancy of logs by indicator species was negatively related to adjacent young clear-cut edges, but this effect decreased with increasing clear-cut age. The occupancy of logs by indicator species also increased with increasing distance to the natural edges. In contrast, the occupancy of logs by common species was positively related or unrelated to distance to clear-cut edges regardless of the edge age, and this was partly explained by fungal specificity to substrate quality. Stand-level mean richness and mean occupancy of logs did not change for indicator or common species over a decade. By illustrating the importance of spatial and temporal dimensions of edge effects, we extend the general understanding of the distribution and diversity of substrate-confined fungi in fragmented old-growth forests. Our results highlight the importance of longer forest rotation times adjacent to small protected areas and forest set-asides, where it may take more than 50 yr for indicator species richness levels to recover to occupancy levels observed in the forest interior. Also, non-simultaneous clear-cutting of surrounding productive forests in a way that reduces the edge effect over time (i.e., dynamic buffers) may increase the effective core area of small forest set-asides and improve their performance on protecting species of special concern for

  11. Rapid profiling of polymeric phenolic acids in Salvia miltiorrhiza by hybrid data-dependent/targeted multistage mass spectrometry acquisition based on expected compounds prediction and fragment ion searching.

    Science.gov (United States)

    Shen, Yao; Feng, Zijin; Yang, Min; Zhou, Zhe; Han, Sumei; Hou, Jinjun; Li, Zhenwei; Wu, Wanying; Guo, De-An

    2018-04-01

    Phenolic acids are the major water-soluble components in Salvia miltiorrhiza (>5%). According to previous studies, many of them contribute to the cardiovascular effects and antioxidant effects of S. miltiorrhiza. Polymeric phenolic acids can be considered as the tanshinol derived metabolites, e.g., dimmers, trimers, and tetramers. A strategy combined with tanshinol-based expected compounds prediction, total ion chromatogram filtering, fragment ion searching, and parent list-based multistage mass spectrometry acquisition by linear trap quadropole-orbitrap Velos mass spectrometry was proposed to rapid profile polymeric phenolic acids in S. miltiorrhiza. More than 480 potential polymeric phenolic acids could be screened out by this strategy. Based on the fragment information obtained by parent list-activated data dependent multistage mass spectrometry acquisition, 190 polymeric phenolic acids were characterized by comparing their mass information with literature data, and 18 of them were firstly detected from S. miltiorrhiza. Seven potential compounds were tentatively characterized as new polymeric phenolic acids from S. miltiorrhiza. This strategy facilitates identification of polymeric phenolic acids in complex matrix with both selectivity and sensitivity, which could be expanded for rapid discovery and identification of compounds from complex matrix. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. A new instrument of VUV laser desorption/ionization mass spectrometry imaging with micrometer spatial resolution and low level of molecular fragmentation.

    Science.gov (United States)

    Wang, Jia; Liu, Feng; Mo, Yuxiang; Wang, Zhaoying; Zhang, Sichun; Zhang, Xinrong

    2017-11-01

    Mass spectrometry imaging (MSI) has important applications in material research, biology, and medicine. The MSI method based on UV laser desorption/ionization (UVLDI) can obtain images of intact samples, but has a high level of molecular fragmentation. In this work, we report a new MSI instrument that uses a VUV laser (125.3 nm) as a desorption/ionization source to exploit its advantages of high single photon energy and small focus size. The new instrument was tested by the mass spectra of Nile red and FGB (Fibrinogen beta chain) samples and mass spectrometric images of a fly brain section. For the tested samples, the VUVDI method offers lower levels of molecular fragmentations and higher sensitivities than those of the UVLDI method and second ion mass spectrometry imaging method using a Bi 3 + beam. The ablation crater produced by the focused VUV laser on a quartz plate has an area of 10 μm 2 . The VUV laser is prepared based on the four-wave mixing method using three collimated laser beams and a heated Hg cell.

  13. A new instrument of VUV laser desorption/ionization mass spectrometry imaging with micrometer spatial resolution and low level of molecular fragmentation

    Science.gov (United States)

    Wang, Jia; Liu, Feng; Mo, Yuxiang; Wang, Zhaoying; Zhang, Sichun; Zhang, Xinrong

    2017-11-01

    Mass spectrometry imaging (MSI) has important applications in material research, biology, and medicine. The MSI method based on UV laser desorption/ionization (UVLDI) can obtain images of intact samples, but has a high level of molecular fragmentation. In this work, we report a new MSI instrument that uses a VUV laser (125.3 nm) as a desorption/ionization source to exploit its advantages of high single photon energy and small focus size. The new instrument was tested by the mass spectra of Nile red and FGB (Fibrinogen beta chain) samples and mass spectrometric images of a fly brain section. For the tested samples, the VUVDI method offers lower levels of molecular fragmentations and higher sensitivities than those of the UVLDI method and second ion mass spectrometry imaging method using a Bi3+ beam. The ablation crater produced by the focused VUV laser on a quartz plate has an area of 10 μm2. The VUV laser is prepared based on the four-wave mixing method using three collimated laser beams and a heated Hg cell.

  14. Water masses and property distribution in the EEZ of Mauritius

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Singbal, S.Y.S.; George, M.D.

    Water masses and their properties have been studied in the Mauritian during September-October, 1987. Surface water is characterizEd. by two water masses: 1) a warm (temp. 27 degrees C) and relatively saline water (salinity 35.3 x 10 sup(-3)) which...

  15. Emission of intermediate mass fragments in the heavy ion interaction of (14.0 MeV/u) Pb+Au

    International Nuclear Information System (INIS)

    Khan, E.U.; Qureshi, I.E.; Shahzad, M.I.; Khattak, F.N.; Khan, H.A.

    2001-01-01

    We have studied the heavy ion interactions of (14.0 MeV/u) Pb + Au using two threshold detectors, mica and CN-85. A thin layer of Au was deposited on each of the three mica and two CN-85 detector pieces. These target-detector assemblies were exposed to a beam of 14.0 MeV/u Pb ions having the fluence of 1.5x10 6 cm 2 at GSI, Darmstadt, Germany. After removing the target material and etching the samples in appropriate etchants, we scanned 32.29 cm 2 and 24.97 cm 2 area of mica and CN-85, respectively. Based on the observed number of events of various multiplicities, we have determined the total as well as partial experimental reaction cross-sections. It is shown that a significant number of intermediate mass fragments are emitted along with the heavy fragments in the present reaction

  16. Patient distribution in a mass casualty event of an airplane crash

    NARCIS (Netherlands)

    Postma, Ingri L. E.; Weel, Hanneke; Heetveld, Martin J.; van der Zande, Ineke; Bijlsma, Taco S.; Bloemers, Frank W.; Goslings, J. Carel

    2013-01-01

    Difficulties have been reported in the patient distribution during Mass Casualty Incidents. In this study we analysed the regional patient distribution protocol (PDP) and the actual patient distribution after the 2009 Turkish Airlines crash near Amsterdam. Analysis of the patient distribution of 126

  17. Mass distributions of a macromolecular assembly based on ...

    Indian Academy of Sciences (India)

    Unknown

    Because of variation in the number and masses of subunits, ... and scanning transmission electron microscopy (STEM) appearances ... 36 linker chains, in agreement with the model proposed ... Each of them is determined by the two integer.

  18. Mass measurement of cooled neutron-deficient bismuth projectile fragments with time-resolved Schottky mass spectrometry at the FRS-ESR facility

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, Yu.A.; Geissel, H. [Giessen Univ. (Germany); Radon, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (DE)] [and others

    2005-06-01

    Masses of 582 neutron-deficient nuclides (30{<=}Z{<=}85) were measured with time-resolved Schottky mass spectrometry at the FRS-ESR facility at GSI, 117 were used for calibration. The masses of 71 nuclides were obtained for the first time. A typical mass accuracy of 30 {mu}u was achieved. These data have entered the latest atomic mass evaluation. The mass determination of about 140 additional nuclides was possible via known energies (Q-values) of {alpha}-, {beta}-, or proton decays. The obtained results are compared with the results of other measurements. (orig.)

  19. Fragmentation of high-energy ionic hydrogen clusters by single collision with helium

    International Nuclear Information System (INIS)

    Ouaskit, S.; Farizon, B.; Farizon, M.; Gaillard, M.J.; Chevarier, A.; Chevarier, N.; Gerlic, E.; Stern, M.

    1994-09-01

    Fragmentation of mass-selected 60-keV/amu-H n + induced by single collision with helium has been studied for various cluster sizes n (9, 13,21, 25, and 31). The absolute cross sections of the charged fragments H p + are measured from p equal to n-2. The deduced mass distributions are strongly different from those obtained at lower collision energy (where molecular evaporation is mainly involved) due to a strong production of ionic fragments with a size of p/n -τ , where A is the normalized fragment mass (p/n) and τ an exponent close to 2.6. (authors)

  20. USE OF THE DE LIOCOURT QUOTIENT IN THE EVALUATION OF THE DIAMETRIC DISTRIBUTION IN FRAGMENTS OF OMBROPHYLOUS FOREST, PERNAMBUCO STATE-BRAZIL

    Directory of Open Access Journals (Sweden)

    Francisco Tarcísio Alves Junior

    2010-08-01

    Full Text Available Great part of the biodiversity of the ecosystem of tropical forests is being lost even before we have full knowledge of its natural wealth, making it important perform studies that can provide knowledge and the maintenance of its structure, besides making possible the exploration of its products, goods and/or services in a planned and rational form, guaranteeing the continuous flow of these resources. The general objective of this study was to use the De Liocourt quotient in the evaluation of the diametric distribution in fragments of Ombrophylous Forest located in the city of Catende, Pernambuco state - Brazil, having as specific objectives: to describe the diametric structure of the fragments and the species of greater importance using the Value of Importance Index (VI; and to evaluate the degradation and the state of succession of the studied areas. The diametric distribution revealed uneven-aged forests as the diametric curve of distribution resembled a reverse J-shape. The values of basal area in the fragments were of 23.6 and 20.9 m2.ha-1, for Mata das Caldeiras and Mata das Galinhas. The fragments were, on average, in the secondary period of succession. Some species presented difficulties in the rate of recruitment, which could lead to the extinguishing of some species in the future. Species, such as Tapirira guianensis Aubl., Dialium guianense (Aubl. Sandwith and Brosimum discolor Schott, demonstrated a distinct diametric structure among the fragments. The species Plathymenia foliolosa Benth. presented accented discontinuities in the diametric structure in both areas.

  1. A Dual Power Law Distribution for the Stellar Initial Mass Function

    Science.gov (United States)

    Hoffmann, Karl Heinz; Essex, Christopher; Basu, Shantanu; Prehl, Janett

    2018-05-01

    We introduce a new dual power law (DPL) probability distribution function for the mass distribution of stellar and substellar objects at birth, otherwise known as the initial mass function (IMF). The model contains both deterministic and stochastic elements, and provides a unified framework within which to view the formation of brown dwarfs and stars resulting from an accretion process that starts from extremely low mass seeds. It does not depend upon a top down scenario of collapsing (Jeans) masses or an initial lognormal or otherwise IMF-like distribution of seed masses. Like the modified lognormal power law (MLP) distribution, the DPL distribution has a power law at the high mass end, as a result of exponential growth of mass coupled with equally likely stopping of accretion at any time interval. Unlike the MLP, a power law decay also appears at the low mass end of the IMF. This feature is closely connected to the accretion stopping probability rising from an initially low value up to a high value. This might be associated with physical effects of ejections sometimes (i.e., rarely) stopping accretion at early times followed by outflow driven accretion stopping at later times, with the transition happening at a critical time (therefore mass). Comparing the DPL to empirical data, the critical mass is close to the substellar mass limit, suggesting that the onset of nuclear fusion plays an important role in the subsequent accretion history of a young stellar object.

  2. Molecular Isotopic Distribution Analysis (MIDAs) with adjustable mass accuracy.

    Science.gov (United States)

    Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo

    2014-01-01

    In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

  3. The fragment ion C13H9O2 m/z 197 in the mass spectra of 2-(2'-R-phenyl)benzoic acids

    International Nuclear Information System (INIS)

    Gills, R.G.; Porter, Q.N.

    1990-01-01

    In the electron impact mass spectrum of 2-( ' -R-phenyl)benzoic acids where R = H, NO 2 , OCH 3 , COOH, or Br, and abundant fragment ion m/z 197 is formed by an ipso substitution in which R is expelled as a radical. The structure of the ion m/z 197 has been shown by collision-activated dissociation to be identical with that of the protonated molecule formed by methane chemical ionization of 6H-dibenzo[b,d]pyran-6-one. 11 refs., 1 fig., ills

  4. Hypervelocity Impact Test Fragment Modeling: Modifications to the Fragment Rotation Analysis and Lightcurve Code

    Science.gov (United States)

    Gouge, Michael F.

    2011-01-01

    Hypervelocity impact tests on test satellites are performed by members of the orbital debris scientific community in order to understand and typify the on-orbit collision breakup process. By analysis of these test satellite fragments, the fragment size and mass distributions are derived and incorporated into various orbital debris models. These same fragments are currently being put to new use using emerging technologies. Digital models of these fragments are created using a laser scanner. A group of computer programs referred to as the Fragment Rotation Analysis and Lightcurve code uses these digital representations in a multitude of ways that describe, measure, and model on-orbit fragments and fragment behavior. The Dynamic Rotation subroutine generates all of the possible reflected intensities from a scanned fragment as if it were observed to rotate dynamically while in orbit about the Earth. This calls an additional subroutine that graphically displays the intensities and the resulting frequency of those intensities as a range of solar phase angles in a Probability Density Function plot. This document reports the additions and modifications to the subset of the Fragment Rotation Analysis and Lightcurve concerned with the Dynamic Rotation and Probability Density Function plotting subroutines.

  5. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    Contemporary industrialized architecture based on advanced information technology and highly technological production processes, implies a radically different approach to architecture than what we have experienced in the past. Works of architecture composed of prefabricated building components......, contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... tries to develop a strategy for the architect dealing with industrially based architecture; a strategy which exploits architectural potentials in industrial building, which recognizes the rules of mass production and which redefines the architect’s position among the agents of building. If recent...

  6. Identification of fission-like events in the 16O + 181Ta system: Mass and isotopic yield distribution

    International Nuclear Information System (INIS)

    Sharma, Vijay R.; Yadav, Abhishek; Singh, Devendra P.; Unnati,; Singh, B. P.; Prasad, R.; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Golda, K. S.; Sinha, A. K.

    2011-01-01

    In this paper, nuclear reaction cross sections for 24 fission-like fragments (30≤Z≤60) have been measured for the 6.5 MeV/A 16 O + 181 Ta system. The recoil-catcher activation technique was employed followed by off-line γ spectroscopy. The isotopic yield distributions for yttrium and indium isotopes have been obtained from the experimental data. The variance of the presently measured isotopic yield distributions have been found to be in agreement with the literature values. However, the variance of the mass distribution of fission residues has found to be narrower as compared to other relatively heavier systems. A self-consistent approach to determining the isobaric charge dispersion parameters has been adopted. The measured fission cross sections at 97 and 100 MeV are satisfactorily described by a statistical model code. An attempt has been made to explain the production cross sections of intermediate mass residues in the fission of heavy residues populated via complete and/or incomplete fusion processes.

  7. Determination of the mass-ratio distribution, I: single-lined spectroscopic binary stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1992-01-01

    For single-lined spectroscopic binary stars (sbi), the mass ratio q = Msec=Mprim is calculated from the mass function f(m), which is determined from observations. For statistical investigations of the mass-ratio distribution, the term sin^3 i, that remains in the cubic equation from which q is

  8. Conservation laws and mass distribution in the planet formation process

    International Nuclear Information System (INIS)

    Farinella, P.; Paolicchi, P.

    1977-01-01

    Within the framework of the nebular theory of the origin of the solar system, conservation laws are applied to the condensation of a ring-shaped cloud of orbiting particles. The final configuration is assumed to be a point-like planet in a circular orbit around the Sun. On this ground, it is possible to relate the masses of the planets with the interplanetary distances. This relation is confirmed satisfactorily by the observed masses and orbital radii of several planets and satellites of the solar system. (Auth.)

  9. Simultaneous investigation of fission fragments and neutrons in 252Cf(s,f)

    International Nuclear Information System (INIS)

    Budtz-Joergensen, C.; Knitter, H.H.

    1986-01-01

    The gridded twin ion chamber developed at CBNM is used to measure the kinetic energy-, mass- and angular distributions of the fission fragments of 252 Cf in an advantageous 4π-geometry. Together with a neutron time-of-flight detector this experimental arrangement permits to measure the correlation between neutron emission, fragment angle, mass and energy in the spontaneous fission of 252 Cf. With the present experimental set-up a mass resolution for fission fragments of 0.5 a.m.u., an angular resolution of Δcosθ = 0.05 and a timing resolution of 0.7 ns FWHM were observed. Preliminary evaluations of the raw experimental data are presented for the fission fragment mass distribution, the average total kinetic energy and their variance as function of mass, the angular distribution between fragments and neutrons, the number of neutrons emitted per fragment as function of fragment mass, the average neutron emission energies as function of mass, and the prompt fission neutron spectrum averaged over all fragments. (author)

  10. A multivariate rank test for comparing mass size distributions

    KAUST Repository

    Lombard, F.; Potgieter, C. J.

    2012-01-01

    Particle size analyses of a raw material are commonplace in the mineral processing industry. Knowledge of particle size distributions is crucial in planning milling operations to enable an optimum degree of liberation of valuable mineral phases

  11. DNA double-strand breaks in mammalian cells exposed to γ-rays and very heavy ions. Fragment-size distributions determined by pulsed-field gel electrophoresis

    International Nuclear Information System (INIS)

    Kraxenberger, F.; Friedl, A.A.; Eckardt-Schupp, F.; Weber, K.J.; Flentje, M.; Quicken, P.; Kellerer, A.M.; Ludwig-Maximilians University, Munich

    1998-01-01

    The spatial distribution of DNA double-strand breaks (DSB) was assessed after treatment of mammalian cells (V79) with densely ionizing radiation. Cells were exposed to beams of heavy charged particles (calcium ions: 6.9 MeV/u, 2.1.10 3 keV/μm; uranium ions: 9.0 MeV/u, 1.4.10 4 keV/μm) at the linear accelerator UNILAC of GSI, Darmstadt. DNA was isolated in agarose plugs and subjected to pulsed-field gel electrophoresis under conditions that separated DNA fragments of size 50 kbp to 5 Mbp. The measured fragment distributions were compared to those obtained after γ-irradiation and were analyzed by means of a convolution and a deconvolution technique. In contrast to the finding for γ-radiation, the distributions produced by heavy ions do not correspond to the random breakage model. Their marked overdispersion and the observed excess of short fragments reflect spatial clustering of DSB that extends over large regions of the DNA, up to several mega base pairs (Mbp). At fluences of 0.75 and 1.5/μm 2 , calcium ions produce nearly the same shape of fragment spectrum, merely with a difference in the amount of DNA entering the gel; this suggests that the DNA is fragmented by individual calcium ions. At a fluence of 0.8/μm 2 uranium ions produce a profile that is shifted to smaller fragment sizes in comparison to the profile obtained at a fluence of 0.4/μm 2 ; this suggests cumulative action of two separate ions in the formation of fragments. These observations are not consistent with the expectation that the uranium ions, with their much larger LET, should be more likely to produce single particle action than the calcium ions. However, a consideration of the greater lateral extension of the tracks of the faster uranium ions explains the observed differences; it suggests that the DNA is closely coiled so that even DNA locations several Mbp apart are usually not separated by less than 0.1 or 0.2 μm. (orig.)

  12. Distribution of pagerank mass among principle components of the web

    NARCIS (Netherlands)

    Avrachenkov, Konstatin; Litvak, Nelli; Pham, Kim Son; Bonato, A.; Chung, F.R.K.

    2007-01-01

    We study the PageRank mass of principal components in a bow-tie Web Graph, as a function of the damping factor c. Using a singular perturbation approach, we show that the PageRank share of IN and SCC components remains high even for very large values of the damping factor, in spite of the fact that

  13. Fission fragment angular distributions in proton-induced fission of 209Bi (p,f) and 197Au (p,f)

    International Nuclear Information System (INIS)

    Soheily, S.; Noshad, H.; Lamehi-Rashti, M.

    2002-01-01

    The fission fragment angular distributions have been measured for proton-induced fission of 209 B i and 197 A u nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model. The fission cross sections of 209 B i and 197 A u nuclei were also measured and compared with the previous works

  14. Universality of fragment shapes.

    Science.gov (United States)

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-03-16

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.

  15. Measuring Distributional Inequality: Relative Body Mass Index Distributions by Gender, Race/Ethnicity, and Education, United States (1999–2006

    Directory of Open Access Journals (Sweden)

    Brian C. Houle

    2010-01-01

    Full Text Available Few studies consider obesity inequalities as a distributional property. This study uses relative distribution methods to explore inequalities in body mass index (BMI; kg/m2. Data from 1999–2006 from the National Health and Nutrition Examination Survey were used to compare BMI distributions by gender, Black/White race, and education subgroups in the United States. For men, comparisons between Whites and Blacks show a polarized relative distribution, with more Black men at increased risk of over or underweight. Comparisons by education (overall and within race/ethnic groups effects also show a polarized relative distribution, with more cases of the least educated men at the upper and lower tails of the BMI distribution. For women, Blacks have a greater probability of high BMI values largely due to a right-shifted BMI distribution relative to White women. Women with less education also have a BMI distribution shifted to the right compared to the most educated women.

  16. Imaging of mass distribution in paper by electrography technique, (2)

    International Nuclear Information System (INIS)

    Tomimasu, Hiroshi; Luner, P.

    1991-01-01

    Four paper imaging techniques (β-radiography, electrography, light transmission, and soft x-radiography) were compared in terms of their process parameters and image characteristics (exposure time, spatial variation, contrast, spatial resolution, correlation with mass, and limitation in basis weight range) with the same newsprint sample and electron microscope film. As far as the imaging conditions chosen here are concerned, electrography gave a higher spatial resolution, shorter exposure time, and the wider basis weight range than β-radiography. Light transmission image could be obtained in a very short time, but gave the poorest spatial resolution and correlation with mass. Soft x-radiography gave the highest spatial resolution, but the poorest spatial variation and contrast. The proper imaging technique and conditions need to be selected depending on the specific paper property in question. (author)

  17. Detection of irradiated food by the changes in protein molecular mass distribution

    International Nuclear Information System (INIS)

    Niciforovic, A.; Radojcic, M.; Milosavljevic, B.H.

    1998-01-01

    Complete text of publication follows. The present work deals with the radiation-induced damage of proteins, which is followed by the change in the molecular mass. The phenomenon was studied on protein rich samples, i.e., chicken meat and dehydrated egg white. The radiation dose applied was in the range of the ones used for food microbial control. Chicken drumstick and chicken white meat proteins were separated according to their molecular mass. The protein profile was compared to the meat samples irradiated in the frozen state with 5 kGy at 60 Co source. In the case of chicken white meat, irradiation produces both nonselective protein scission (e.g. the amount of proteins of molecular mass larger than 30 kDa decreases, while the amount of proteins of molecular mass smaller than 30 kDa increases), and selective protein scission (e.g. appearance of a protein fragment of molecular mass equal to 18 kDa). In the case of chicken drumstick proteins the irradiation induces both the protein scission and the aggregation. The changes are nonspecific as well as specific and the generation of Mm = 18 kDa protein fragment was observed again. Irradiation of aerated dehydrated egg white proteins produces only nonselective protein scission. The results are discussed in view of the routine application of SDS-PAGE method for the detection of irradiated foodstuff

  18. STRESS DISTRIBUTION IN THE STRATIFIED MASS CONTAINING VERTICAL ALVEOLE

    Directory of Open Access Journals (Sweden)

    Bobileva Tatiana Nikolaevna

    2017-08-01

    Full Text Available Almost all subsurface rocks used as foundations for various types of structures are stratified. Such heterogeneity may cause specific behaviour of the materials under strain. Differential equations describing the behaviour of such materials contain rapidly fluctuating coefficients, in view of this, solution of such equations is more time-consuming when using today’s computers. The method of asymptotic averaging leads to getting homogeneous medium under study to averaged equations with fixed factors. The present article is concerned with stratified soil mass consisting of pair-wise alternative isotropic elastic layers. In the results of elastic modules averaging, the present soil mass with horizontal rock stratification is simulated by homogeneous transversal-isotropic half-space with isotropy plane perpendicular to the standing axis. Half-space is loosened by a vertical alveole of circular cross-section, and virgin ground is under its own weight. For horizontal parting planes of layers, the following two types of surface conditions are set: ideal contact and backlash without cleavage. For homogeneous transversal-isotropic half-space received with a vertical alveole, the analytical solution of S.G. Lekhnitsky, well known in scientific papers, is used. The author gives expressions for stress components and displacements in soil mass for different marginal conditions on the alveole surface. Such research problems arise when constructing and maintaining buildings and when composite materials are used.

  19. Effect of distributive mass of spring on power flow in engineering test

    Science.gov (United States)

    Sheng, Meiping; Wang, Ting; Wang, Minqing; Wang, Xiao; Zhao, Xuan

    2018-06-01

    Mass of spring is always neglected in theoretical and simulative analysis, while it may be a significance in practical engineering. This paper is concerned with the distributive mass of a steel spring which is used as an isolator to simulate isolation performance of a water pipe in a heating system. Theoretical derivation of distributive mass effect of steel spring on vibration is presented, and multiple eigenfrequencies are obtained, which manifest that distributive mass results in extra modes and complex impedance properties. Furthermore, numerical simulation visually shows several anti-resonances of the steel spring corresponding to impedance and power flow curves. When anti-resonances emerge, the spring collects large energy which may cause damage and unexpected consequences in practical engineering and needs to be avoided. Finally, experimental tests are conducted and results show consistency with that of the simulation of the spring with distributive mass.

  20. The calibration of the intramolecular nitrogen isotope distribution in nitrous oxide measured by isotope ratio mass spectrometry.

    Science.gov (United States)

    Westley, Marian B; Popp, Brian N; Rust, Terri M

    2007-01-01

    Two alternative approaches for the calibration of the intramolecular nitrogen isotope distribution in nitrous oxide using isotope ratio mass spectrometry have yielded a difference in the 15N site preference (defined as the difference between the delta15N of the central and end position nitrogen in NNO) of tropospheric N2O of almost 30 per thousand. One approach is based on adding small amounts of labeled 15N2O to the N2O reference gas and tracking the subsequent changes in m/z 30, 31, 44, 45 and 46, and this yields a 15N site preference of 46.3 +/- 1.4 per thousand for tropospheric N2O. The other involves the synthesis of N2O by thermal decomposition of isotopically characterized ammonium nitrate and yields a 15N site preference of 18.7 +/- 2.2 per thousand for tropospheric N2O. Both approaches neglect to fully account for isotope effects associated with the formation of NO+ fragment ions from the different isotopic species of N2O in the ion source of a mass spectrometer. These effects vary with conditions in the ion source and make it impossible to reproduce a calibration based on the addition of isotopically enriched N2O on mass spectrometers with different ion source configurations. These effects have a much smaller impact on the comparison of a laboratory reference gas with N2O synthesized from isotopically characterized ammonium nitrate. This second approach was successfully replicated and leads us to advocate the acceptance of the site preference value 18.7 +/- 2.2 per thousand for tropospheric N2O as the provisional community standard until further independent calibrations are developed and validated. We present a technique for evaluating the isotope effects associated with fragment ion formation and revised equations for converting ion signal ratios into isotopomer ratios. Copyright 2007 John Wiley & Sons, Ltd.

  1. Fragment charge and energy distributions in the 1.8-4.8 GeV 3He + natAg, 197Au reactions

    International Nuclear Information System (INIS)

    Bracken, D.S.; Foxford, E.R.; Kwiatkowski, K.

    1995-01-01

    Moving source fits have been performed for IMFs as a function of observables related to collision violence in the 1.8-4.8 GeV 3 He + nat Ag, l97 Au reactions. The systematic behavior of the source properties and fragment charge distributions will be reviewed. The evolution of the spectral Coulomb parameters provides evidence for nuclear expansion prior to multifragmentation, suggesting a breakup density of p/p o ∼ 1/3. The charge distributions will be examined in terms of power-law fits and moment analyses

  2. Anisotropy in angular distributions of 238U fission fragments by photons, produced in high energy electron interaction with Si monocrystal

    International Nuclear Information System (INIS)

    Kasilov, V.I.; Lapin, N.N.

    1981-01-01

    An enhancement is detected under the angle of 90 deg in the fission fragment yield from 238 U nuclei produced by photons emitted by high-energy electrons passing through a silicon monocrystal. The results enable one to select the most optimal conditions to obtain maximal yields of nuclear particles [ru

  3. The supernova progenitor mass distributions of M31 and M33: further evidence for an upper mass limit

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Weisz, Daniel R. [University of California Observatories, Santa Cruz, CA 95064 (United States); Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan [Box 351580, The University of Washington Seattle, WA 98195 (United States); Murphy, Jeremiah W. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Dolphin, Andrew E., E-mail: zgjennin@ucsc.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States)

    2014-11-10

    Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form dN/dM∝M {sup –α}. Our new larger sample of M31 progenitors follows a distribution with α=4.4{sub −0.4}{sup +0.4}, and the M33 sample follows a distribution with α=3.8{sub −0.5}{sup +0.4}. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives α=4.2{sub −0.3}{sup +0.3}. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function, which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix α = 2.35 and treat the maximum mass as a free parameter, we find M {sub max} ∼ 35-45 M {sub ☉}, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.

  4. Jet fragmentation

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1985-10-01

    The paper reviews studies on jet fragmentation. The subject is discussed under the topic headings: fragmentation models, charged particle multiplicity, bose-einstein correlations, identified hadrons in jets, heavy quark fragmentation, baryon production, gluon and quark jets compared, the string effect, and two successful models. (U.K.)

  5. THE FORMATION OF THE PRIMITIVE STAR SDSS J102915+172927: EFFECT OF THE DUST MASS AND THE GRAIN-SIZE DISTRIBUTION

    International Nuclear Information System (INIS)

    Bovino, S.; Banerjee, R.; Grassi, T.; Schleicher, D. R. G.

    2016-01-01

    Understanding the formation of the extremely metal-poor star SDSS J102915+172927 is of fundamental importance to improve our knowledge on the transition between the first and second generation of stars in the universe. In this paper, we perform three-dimensional cosmological hydrodynamical simulations of dust-enriched halos during the early stages of the collapse process including a detailed treatment of the dust physics. We employ the astrochemistry package krome coupled with the hydrodynamical code enzo assuming grain-size distributions produced by the explosion of core-collapse supernovae (SNe) of 20 and 35 M ⊙ primordial stars, which are suitable to reproduce the chemical pattern of the SDSS J102915+172927 star. We find that the dust mass yield produced from Population III SNe explosions is the most important factor that drives the thermal evolution and the dynamical properties of the halos. Hence, for the specific distributions relevant in this context, the composition, the dust optical properties, and the size range have only minor effects on the results due to similar cooling functions. We also show that the critical dust mass to enable fragmentation provided by semi-analytical models should be revised, as we obtain values one order of magnitude larger. This determines the transition from disk fragmentation to a more filamentary fragmentation mode, and suggests that likely more than one single SN event or efficient dust growth should be invoked to get such high dust content.

  6. THE FORMATION OF THE PRIMITIVE STAR SDSS J102915+172927: EFFECT OF THE DUST MASS AND THE GRAIN-SIZE DISTRIBUTION

    Energy Technology Data Exchange (ETDEWEB)

    Bovino, S.; Banerjee, R. [Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, D-21029 Hamburg (Germany); Grassi, T. [Niels Bohr Institute and Centre for Star and Planet Formation, Øster Voldgade 5-7, DK-1350 Copenhagen (Denmark); Schleicher, D. R. G., E-mail: stefano.bovino@uni-hamburg.de [Departamento de Astronomía, Facultad Ciencias Físicas y Matemáticas, Universidad de Concepción, Av. Esteban Iturra s/n Barrio Universitario, Casilla 160, Concepción (Chile)

    2016-12-01

    Understanding the formation of the extremely metal-poor star SDSS J102915+172927 is of fundamental importance to improve our knowledge on the transition between the first and second generation of stars in the universe. In this paper, we perform three-dimensional cosmological hydrodynamical simulations of dust-enriched halos during the early stages of the collapse process including a detailed treatment of the dust physics. We employ the astrochemistry package krome coupled with the hydrodynamical code enzo assuming grain-size distributions produced by the explosion of core-collapse supernovae (SNe) of 20 and 35 M {sub ⊙} primordial stars, which are suitable to reproduce the chemical pattern of the SDSS J102915+172927 star. We find that the dust mass yield produced from Population III SNe explosions is the most important factor that drives the thermal evolution and the dynamical properties of the halos. Hence, for the specific distributions relevant in this context, the composition, the dust optical properties, and the size range have only minor effects on the results due to similar cooling functions. We also show that the critical dust mass to enable fragmentation provided by semi-analytical models should be revised, as we obtain values one order of magnitude larger. This determines the transition from disk fragmentation to a more filamentary fragmentation mode, and suggests that likely more than one single SN event or efficient dust growth should be invoked to get such high dust content.

  7. Spatial and mass distributions of molecular clouds and spiral structure

    International Nuclear Information System (INIS)

    Kwan, J.; Valdes, F.; National Optical Astronomy Observatories, Tucson, AZ)

    1987-01-01

    The growth of molecular clouds resulting from cloud-cloud collisions and coalescence in the Galactic ring between 4 and 8 kpc are modeled, taking into account the presence of a spiral potential and the mutual cloud-cloud gravitational attraction. The mean lifetime of molecular clouds is determined to be about 200 million years. The clouds are present in both spiral arm and interarm regions, but a spiral pattern in their spatial distribution is clearly discernible, with the more massive clouds showing a stronger correlation with the spiral arms. As viewed from within the Galactic disk, however, it is very difficult to ascertain that the molecular cloud distribution in longitude-velocity space has a spiral pattern. 19 references

  8. Differential distributions for top-quark hadro-production with a running mass

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2013-05-15

    We take a look at how the differential distributions for top-quark production are affected by changing to the running mass scheme. Specifically we consider the transverse momentum, rapidity and pair-invariant mass distributions at NLO for the top-quark mass in the MS scheme. It is found that, similar to the total cross section, the perturbative expansion converges faster and the scale dependence improves using the mass in the MS scheme as opposed to the on-shell scheme. We also update the analysis for the total cross section using the now available full NNLO contribution.

  9. Differential distributions for top-quark hadro-production with a running mass

    International Nuclear Information System (INIS)

    Dowling, M.; Moch, S.; Hamburg Univ.

    2013-05-01

    We take a look at how the differential distributions for top-quark production are affected by changing to the running mass scheme. Specifically we consider the transverse momentum, rapidity and pair-invariant mass distributions at NLO for the top-quark mass in the MS scheme. It is found that, similar to the total cross section, the perturbative expansion converges faster and the scale dependence improves using the mass in the MS scheme as opposed to the on-shell scheme. We also update the analysis for the total cross section using the now available full NNLO contribution.

  10. Medium-scale melt-sodium fragmentation experiments

    International Nuclear Information System (INIS)

    Chu, T.Y.; Beattie, A.G.; Drotning, W.D.; Powers, D.A.

    1979-01-01

    The results of a series of fragmentation experiments involving up to 20 Kg of thermitically produced high temperature melts and 23 Kg of sodium are presented. Except for one experiment where some centimeter size particles are observed, the fragment distributions seem to be in the range of previous data. Spatial distribution of the fragments in the debris bed appears to be stratified. Scanning electron micrographs of fragments indicate fragmentation to be occurring in the molten state for the more intense interactions observed. Interaction data obtained show quiescent periods of 0.5 to 1.5 second between pressure pulses. The force impulse values per unit mass of melt seems to be in the same range as previous experiments

  11. High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Hourani, Nadim; Kuhnert, Nikolai

    2012-10-15

    High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Observational Constraints on Quasar Black Hole Mass Distributions, Eddington Ratio Distributions, and Lifetimes

    DEFF Research Database (Denmark)

    Kelly, Brandon C.; Vestergaard, Marianne; Fan, X.

    2010-01-01

    I will present the black hole mass function (BHMF) of broad line quasars in the SDSS DR3. We employ a powerful Bayesian statistical technique that corrects for incompleteness and the statistical uncertainty in the mass estimates. We find evidence that the most massive black hole appeared as quasars...... earlier in the universe, and that most quasars are not radiating at or near the Eddington limit. I will also present constraints on the quasar lifetime and maximum black hole mass, derived from the mass functions....

  13. Rack Distribution Effects on MPLM Center of Mass

    Science.gov (United States)

    Tester, John T.

    2005-01-01

    This research was in support of exploring the need for more flexible "center of gravity (CG) specifications than those currently established by NASA for the Multi-Purpose Logistics Module (MPLM). The MPLM is the cargo carrier for International Space Station (ISS) missions. The MPLM provides locations for 16 standard racks, as shown in Figure 1; not all positions need to be filled in any given flight. The MPLM coordinate system (X(sub M), Y(sub M), Z(sub M)) is illustrated as well. For this project, the primary missions of interest were those which supply the ISS and remove excess materials on the return flights. These flights use a predominate number of "Resupply Stowage Racks" (RSR) and "Resupply Stowage Platforms" (RSP). In these two types of racks, various smaller items are stowed. Hence, these racks will exhibit a considerable range of mass values as well as a range as to where their individual CG are located.

  14. THE DEPENDENCE OF PRESTELLAR CORE MASS DISTRIBUTIONS ON THE STRUCTURE OF THE PARENTAL CLOUD

    International Nuclear Information System (INIS)

    Parravano, Antonio; Sánchez, Néstor; Alfaro, Emilio J.

    2012-01-01

    The mass distribution of prestellar cores is obtained for clouds with arbitrary internal mass distributions using a selection criterion based on the thermal and turbulent Jeans mass and applied hierarchically from small to large scales. We have checked this methodology by comparing our results for a log-normal density probability distribution function with the theoretical core mass function (CMF) derived by Hennebelle and Chabrier, namely a power law at large scales and a log-normal cutoff at low scales, but our method can be applied to any mass distributions representing a star-forming cloud. This methodology enables us to connect the parental cloud structure with the mass distribution of the cores and their spatial distribution, providing an efficient tool for investigating the physical properties of the molecular clouds that give rise to the prestellar core distributions observed. Simulated fractional Brownian motion (fBm) clouds with the Hurst exponent close to the value H = 1/3 give the best agreement with the theoretical CMF derived by Hennebelle and Chabrier and Chabrier's system initial mass function. Likewise, the spatial distribution of the cores derived from our methodology shows a surface density of companions compatible with those observed in Trapezium and Ophiucus star-forming regions. This method also allows us to analyze the properties of the mass distribution of cores for different realizations. We found that the variations in the number of cores formed in different realizations of fBm clouds (with the same Hurst exponent) are much larger than the expected root N statistical fluctuations, increasing with H.

  15. Identification of Estrogen-responsive Vitelline Envelope Protein Fragments from Rainbow Trout (Oncorhynchus mykiss) Plasma Using Mass Spectrometry

    Science.gov (United States)

    Plasma protein biomarkers associated with exposure of rainbow trout (Oncorhynchus mykiss) to 17β-estradiol were isolated and identified using novel sample preparation techniques and state-of-the-art mass spectrometry and bioinformatics approaches. Juvenile male and female trout ...

  16. Mass yield distributions for the reactions Ca+Ca, Nb+Nb and Ca+Ca at E/A=800 MeV in the molecular-dynamical model

    International Nuclear Information System (INIS)

    Kiselev, S.M.

    1987-01-01

    Mass yield distributions obtained on the basis of the molecular-dynamical model are presented for the Ca+Ca, Nb+Nb reactions at E/A=400 MeV and Ca+Ca reaction at E/A=800 MeV. For the fragments with masses upto quarter of the mass of initial nucleus the model predicts a power law for mass spectra with almost the same value of the exponent. Such the behaviour is roughly a result of the superposition of the fireball breakup and the disintegration of spectator regions rather than the evidence of a liquid-gas-like phase transition in hot nuclear matter

  17. Topographical distribution of phosphorylation sites of phosvitins by mass spectrometry.

    Science.gov (United States)

    Czernick, Drew; Liu, Jess; Serge, Dibart; Salih, Erdjan

    2013-05-27

    Phosvitin, derived from the vitellogenin II gene protein, is a highly phosphorylated protein found in egg yolk. A second hypothetical protein has been predicted based on the vitellogenin I gene, but has not been defined at the protein level. Mass spectrometric analysis was used to identify the phosphopeptide sequences and the precise sites of phosphorylation of two phosvitins, phosvitin 1 and phosvitin 2 derived from vitellogenins I and II, respectively. Samples of native phosvitin were subjected to tryptic digestion followed by mass spectrometric analysis: (i) native phosvitin peptides, (ii) after treatment with NaOH, and (iii) after chemical derivatization of P-Ser/P-Thr residues by dithiothreitol under base-catalyzed conditions. A combination of these approaches led to the identification of 68 and 35 phosphopeptides with 89 (81 P-Ser and 8 P-Thr residues) and 62 (57 P-Ser and 5 P-Thr residues) phosphorylation sites of phosvitin 1 and phosvitin 2, respectively. These data for the first time documented on a large scale the major states and sites of phosphorylation of phosvitins with a total of 151 phosphorylation sites. Importantly, the present work also provided the first direct de novo protein amino-acid sequence data for phosvitin 1 protein and evidence for the full expression of vitellogenin I gene. We have for the first time generated a large number of phosphopeptides (~100) and identified 151 phosphorylation sites of phosvitin 1 and phosvitin 2, respectively. Importantly, this study also led to the discovery of a novel phosvitin 1 and provided the first direct de novo protein amino-acid sequence data for the full expression of vitellogenin I gene. There is considerable interest in naturally occurring phosphopeptides/phosphoproteins and their application in biomedical fields and in the food industry because of their molecular characteristics and non-toxic nature, hence, our work opens new avenues to pursue such endeavors. In addition, the results provide

  18. Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice

    DEFF Research Database (Denmark)

    Andersen, Steven Arild Wuyts; Konge, Lars; Cayé-Thomasen, Per

    2015-01-01

    IMPORTANCE: Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal...... in understanding skills acquisition and best-practice implementation and organization of training. OBJECTIVE: To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training. DESIGN, SETTING...... plateaued on a score of 16.0 (15.3-16.7) at approximately the ninth repetition, but the individual learning curves were highly variable. CONCLUSIONS AND RELEVANCE: Novices can acquire basic mastoidectomy competencies with self-directed VR simulation training. Training should be organized with distributed...

  19. Analysis of intensities of positive and negative ion species from silicon dioxide films using time-of-flight secondary ion mass spectrometry and electronegativity of fragments

    International Nuclear Information System (INIS)

    Chiba, Kiyoshi

    2010-01-01

    Intensities of positive and negative ion species emitted from thermally oxidized and plasma-enhanced chemical vapor deposited (PECVD) SiO 2 films were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and the Saha-Boltzmann equation. Intensities of positive and negative secondary ion species were normalized to those of 28 Si + and 28 Si - ions, respectively, and an effective temperature of approximately (7.2 ± 0.1) x 10 3 K of the sputtered region bombarded with pulsed 22 kV Au 3 + primary ions was determined. Intensity spectra showed polarity dependence on both n and m values of Si n O m fragments, and a slight shift to negative polarity for PECVD SiO 2 compared to thermally oxidized SiO 2 films. By dividing the intensity ratios of negative-to-positive ions for PECVD SiO 2 by those for thermally oxidized SiO 2 films to cancel statistical factors, the difference in absolute electronegativity (half the sum of ionization potential and electron affinity of fragments) between both films was obtained. An increase in electronegativity for SiO m (m = 1, 2) and Si 2 O m (m = 1-4) fragments for PECVD SiO 2 films compared to thermally oxidized films was obtained to be 0.1-0.2 Pauling units, indicating a more covalent nature of Si-O bonds for PECVD SiO 2 films compared to the thermally oxidized SiO 2 films.

  20. Optimization of orthotropic distributed-mode loudspeaker using attached masses and multi-exciters.

    Science.gov (United States)

    Lu, Guochao; Shen, Yong; Liu, Ziyun

    2012-02-01

    Based on the orthotropic model of the plate, the method to optimize the sound response of the distributed-mode loudspeaker (DML) using the attached masses and the multi-exciters has been investigated. The attached masses method will rebuild the modes distribution of the plate, based on which multi-exciter method will smooth the sound response. The results indicate that the method can be used to optimize the sound response of the DML. © 2012 Acoustical Society of America

  1. Mass Distribution in Rotating Thin-Disk Galaxies According to Newtonian Dynamics

    Directory of Open Access Journals (Sweden)

    James Q. Feng

    2014-04-01

    Full Text Available An accurate computational method is presented for determining the mass distribution in a mature spiral galaxy from a given rotation curve by applying Newtonian dynamics for an axisymmetrically rotating thin disk of finite size with or without a central spherical bulge. The governing integral equation for mass distribution is transformed via a boundary-element method into a linear algebra matrix equation that can be solved numerically for rotation curves with a wide range of shapes. To illustrate the effectiveness of this computational method, mass distributions in several mature spiral galaxies are determined from their measured rotation curves. All the surface mass density profiles predicted by our model exhibit approximately a common exponential law of decay, quantitatively consistent with the observed surface brightness distributions. When a central spherical bulge is present, the mass distribution in the galaxy is altered in such a way that the periphery mass density is reduced, while more mass appears toward the galactic center. By extending the computational domain beyond the galactic edge, we can determine the rotation velocity outside the cut-off radius, which appears to continuously decrease and to gradually approach the Keplerian rotation velocity out over twice the cut-off radius. An examination of circular orbit stability suggests that galaxies with flat or rising rotation velocities are more stable than those with declining rotation velocities especially in the region near the galactic edge. Our results demonstrate the fact that Newtonian dynamics can be adequate for describing the observed rotation behavior of mature spiral galaxies.

  2. Mapping the Binding Interface of VEGF and a Monoclonal Antibody Fab-1 Fragment with Fast Photochemical Oxidation of Proteins (FPOP) and Mass Spectrometry

    Science.gov (United States)

    Zhang, Ying; Wecksler, Aaron T.; Molina, Patricia; Deperalta, Galahad; Gross, Michael L.

    2017-05-01

    We previously analyzed the Fab-1:VEGF (vascular endothelial growth factor) system described in this work, with both native top-down mass spectrometry and bottom-up mass spectrometry (carboxyl-group or GEE footprinting) techniques. This work continues bottom-up mass spectrometry analysis using a fast photochemical oxidation of proteins (FPOP) platform to map the solution binding interface of VEGF and a fragment antigen binding region of an antibody (Fab-1). In this study, we use FPOP to compare the changes in solvent accessibility by quantitating the extent of oxidative modification in the unbound versus bound states. Determining the changes in solvent accessibility enables the inference of the protein binding sites (epitope and paratopes) and a comparison to the previously published Fab-1:VEGF crystal structure, adding to the top-down and bottom-up data. Using this method, we investigated peptide-level and residue-level changes in solvent accessibility between the unbound proteins and bound complex. Mapping these data onto the Fab-1:VEGF crystal structure enabled successful characterization of both the binding region and regions of remote conformation changes. These data, coupled with our previous higher order structure (HOS) studies, demonstrate the value of a comprehensive toolbox of methods for identifying the putative epitopes and paratopes for biotherapeutic antibodies.

  3. Bounds on the distribution of the number of gaps when circles and lines are covered by fragments: Theory and practical application to genomic and metagenomic projects

    Directory of Open Access Journals (Sweden)

    Marchesi Julian R

    2007-03-01

    Full Text Available Abstract Background The question of how a circle or line segment becomes covered when random arcs are marked off has arisen repeatedly in bioinformatics. The number of uncovered gaps is of particular interest. Approximate distributions for the number of gaps have been given in the literature, one motivation being ease of computation. Error bounds for these approximate distributions have not been given. Results We give bounds on the probability distribution of the number of gaps when a circle is covered by fragments of fixed size. The absolute error in the approximation is typically on the order of 0.1% at 10× coverage depth. The method can be applied to coverage problems on the interval, including edge effects, and applications are given to metagenomic libraries and shotgun sequencing.

  4. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-01-01

    The center-of-mass angular distribution of direct photon events, resulting from proton-antiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermi lab ( CDF) during the 1988-1089 experimental run, is presented. The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momentum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator.

  5. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-04-01

    The center-of-mass angular distribution of direct photon events, resulting from protonantiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermilab ( CDF) during the 1988-1089 experimental run, is presented . The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momemtum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator

  6. Complex fragments from excited actinide nuclei. A new test of the finite range model

    International Nuclear Information System (INIS)

    Sarantities, D.G.; Bowman, D.R.; Wozniak, G.J.; Charity, R.J.; Liu, Z.H.; McDonald, R.J.; McMahan, M.A.; Moretto, L.G.

    1989-01-01

    Complex fragments ranging in charge from 7 ≤ Z ≤ 45 have been detected in binary coincidence following the reaction of 8.4 MeV/u 232 Th+ 12 C, and are shown to arise from the binary decay of a 244 Cm compound nucleus. This work confirms earlier radiochemical observations of very light fragments in the fission fragment mass distribution, establishes their binary character, and interprets their yield in terms of finite range potential energy barriers. (orig.)

  7. Complex fragments from excited actinide nuclei: A new test of the finite range model

    International Nuclear Information System (INIS)

    Sarantities, D.G.; Bowman, D.R.; Wozniak, G.J.; Charity, R.J.; Liu, Z.H.; McDonald, R.J.; McMahan, M.A.; Moretto, L.G.

    1988-05-01

    Complex fragments ranging in charge from 7≤Z≤45 have been detected in binary coincidence following the reaction of 8.4 MeV/u 232 Th+ 12 C, and are shown to arise from the binary decay of a 244 Cm compound nucleus. This work confirms earlier radiochemical observations of very light fragments in the fission fragment mass distribution, establishes their binary character, and interprets their yield in terms of finite range potential energy barriers. 15 refs., 3 figs

  8. MID Max: LC–MS/MS Method for Measuring the Precursor and Product Mass Isotopomer Distributions of Metabolic Intermediates and Cofactors for Metabolic Flux Analysis Applications

    DEFF Research Database (Denmark)

    McCloskey, Douglas; Young, Jamey D.; Xu, Sibei

    2016-01-01

    The analytical challenges to acquire accurate isotopic data of intracellular metabolic intermediates for stationary, nonstationary, and dynamic metabolic flux analysis (MFA) are numerous. This work presents MID Max, a novel LC–MS/MS workflow, acquisition, and isotopomer deconvolution method for MFA...... that takes advantage of additional scan types that maximizes the number of mass isotopomer distributions (MIDs) that can be acquired in a given experiment. The analytical method was found to measure the MIDs of 97 metabolites, corresponding to 74 unique metabolite-fragment pairs (32 precursor spectra and 42...

  9. Measurements of jet fragmentation and the angular distributions of charged particles within and around jets in $pp$ and Pb+Pb with ATLAS

    CERN Document Server

    Rybar, Martin; The ATLAS collaboration

    2018-01-01

    Highly energetic jets produced in ultra-relativistic nuclear collisions are considered to be direct probes to study the properties of the hot and dense QCD matter created in these collisions. The measurement of the fragmentation functions of jets into charged particles in Pb+Pb collisions is sensitive to the strength and mechanism of jet quenching. In this talk, we present the latest measurement of the internal structure of jets and the angular distributions of charged particles within and around jets performed with the ATLAS detector. Fragmentation functions in Pb+Pb collisions and distributions of the transverse momentum of charged particles are compared to the same quantities measured in pp collisions at the same collision energy. Measurements are presented as a function of collision centrality, jet transverse momentum, and jet rapidity at 2.76 and 5.02 TeV. Furthermore, a new measurement of the angular distributions of charged-particles with respect to jet axis extended to distances outside the jet radius...

  10. Universality of projectile fragmentation model

    International Nuclear Information System (INIS)

    Chaudhuri, G.; Mallik, S.; Das Gupta, S.

    2012-01-01

    Presently projectile fragmentation reaction is an important area of research as it is used for the production of radioactive ion beams. In this work, the recently developed projectile fragmentation model with an universal temperature profile is used for studying the charge distributions of different projectile fragmentation reactions with different projectile target combinations at different incident energies. The model for projectile fragmentation consists of three stages: (i) abrasion, (ii) multifragmentation and (iii) evaporation

  11. Insecticide-treated nets mass distribution campaign: benefits and lessons in Zambia.

    Science.gov (United States)

    Masaninga, Freddie; Mukumbuta, Nawa; Ndhlovu, Ketty; Hamainza, Busiku; Wamulume, Pauline; Chanda, Emmanuel; Banda, John; Mwanza-Ingwe, Mercy; Miller, John M; Ameneshewa, Birkinesh; Mnzava, Abraham; Kawesha-Chizema, Elizabeth

    2018-04-24

    Zambia was an early adopter of insecticide-treated nets strategy in 2001, and policy for mass distribution with long-lasting insecticidal nets (LLINs) in 2005. Since then, the country has implemented mass distribution supplemented with routine delivery through antenatal care and under five clinics in health facilities. The national targets of universal (100%) coverage and 80% utilization of LLINs have not been attained. Free mass LLIN distribution campaign in Zambia offers important lessons to inform future campaigns in the African region. This study reviewed LLIN free mass distribution campaign information derived from Zambia's national and World Health Organization Global Malaria Programme annual reports and strategic plans published between 2001 and 2016. In 2014, a nationwide mass distribution campaign in Zambia delivered all the 6.0 million LLINs in 6 out of 10 provinces in 4 months between June and September before the onset of the rainy season. Compared with 235,800 LLINs and 2.9 million LLINs distributed on a rolling basis in 2008 and 2013, respectively, the 2014 mass campaign, which distributed 6 million LLINs represented the largest one-time-nationwide LLIN distribution in Zambia. The province (Luapula) with highest malaria transmission, mostly with rural settings recorded 98-100% sleeping spaces in homes covered with LLINs. The percentage of households owning at least 1 LLIN increased from 50.9% in 2006 to 77.7% in 2015. The 2014 mass campaign involved a coordinated response with substantial investments into macro (central) and micro (district) level planning, capacity building, tracking and logistics management supported by a new non-health sector partnership landscape. Coordination of LLIN distribution and logistics benefited from the mobile phone technology to transmit "real time" data on commodity tracking that facilitated timely delivery to districts. Free mass distribution of LLINs policy was adopted in 2005 in Zambia. Consistently implemented

  12. A liquid chromatography-mass spectrometry method based on class characteristic fragmentation pathways to detect the class of indole-derivative synthetic cannabinoids in biological samples.

    Science.gov (United States)

    Mazzarino, Monica; de la Torre, Xavier; Botrè, Francesco

    2014-07-21

    This article describes a liquid chromatographic/tandem mass spectrometric method, based on the use of precursor ion scan as the acquisition mode, specifically developed to detect indole-derived cannabinoids (phenylacetylindoles, naphthoylindoles and benzoylindoles) in biological fluids (saliva, urine and blood). The method is designed to recognize one or more common "structural markers", corresponding to mass spectral fragments originating from the specific portion of the molecular structure that is common to the aminoalkylindole analogues and that is fundamental for their pharmacological classification. As such, the method is also suitable for detecting unknown substances, provided they contain the targeted portion of the molecular structure. The pre-treatment procedure consists in a liquid/liquid extraction step carried out at neutral pH: this is the only pretreatment in the case of analyses carried out in saliva, while it follows an enzymatic hydrolysis procedure in the case of urine samples, or a protein precipitation step in the case of blood samples. The chromatographic separation is achieved using an octadecyl reverse-phase 5 μm fused-core particle column; while the mass spectrometric detection is carried out by a triple-quadrupole instrument in positive electrospray ionization and precursor ion scan as acquisition mode, selecting, as mass spectral fragments, the indole (m/z 144), the carbonylnaphthalenyl (m/z 155) and the naphthalenyl (m/z 127) moieties. Once developed and optimized, the analytical procedure was validated in term of sensitivity (lower limits of detection in the range of 0.1-0.5 ng mL(-1)), specificity (no interference was detected at the retention times of the analytes under investigation), recovery (higher than 65% with a satisfactory repeatability: CV% lower than 10), matrix effect (lower than 30% for all the biological specimens tested), repeatability of the retention times (CV% lower than 0.1), robustness, and carry over (the positive

  13. Dynamical Mass Measurements of Contaminated Galaxy Clusters Using Support Distribution Machines

    Science.gov (United States)

    Ntampaka, Michelle; Trac, Hy; Sutherland, Dougal; Fromenteau, Sebastien; Poczos, Barnabas; Schneider, Jeff

    2018-01-01

    We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach. We create two mock catalogs from Multidark’s publicly available N-body MDPL1 simulation, one with perfect galaxy cluster membership infor- mation and the other where a simple cylindrical cut around the cluster center allows interlopers to contaminate the clusters. In the standard approach, we use a power-law scaling relation to infer cluster mass from galaxy line-of-sight (LOS) velocity dispersion. Assuming perfect membership knowledge, this unrealistic case produces a wide fractional mass error distribution, with a width E=0.87. Interlopers introduce additional scatter, significantly widening the error distribution further (E=2.13). We employ the support distribution machine (SDM) class of algorithms to learn from distributions of data to predict single values. Applied to distributions of galaxy observables such as LOS velocity and projected distance from the cluster center, SDM yields better than a factor-of-two improvement (E=0.67) for the contaminated case. Remarkably, SDM applied to contaminated clusters is better able to recover masses than even the scaling relation approach applied to uncon- taminated clusters. We show that the SDM method more accurately reproduces the cluster mass function, making it a valuable tool for employing cluster observations to evaluate cosmological models.

  14. Does mass azithromycin distribution impact child growth and nutrition in Niger? A cluster-randomized trial.

    Directory of Open Access Journals (Sweden)

    Abdou Amza

    2014-09-01

    Full Text Available Antibiotic use on animals demonstrates improved growth regardless of whether or not there is clinical evidence of infectious disease. Antibiotics used for trachoma control may play an unintended benefit of improving child growth.In this sub-study of a larger randomized controlled trial, we assess anthropometry of pre-school children in a community-randomized trial of mass oral azithromycin distributions for trachoma in Niger. We measured height, weight, and mid-upper arm circumference (MUAC in 12 communities randomized to receive annual mass azithromycin treatment of everyone versus 12 communities randomized to receive biannual mass azithromycin treatments for children, 3 years after the initial mass treatment. We collected measurements in 1,034 children aged 6-60 months of age.We found no difference in the prevalence of wasting among children in the 12 annually treated communities that received three mass azithromycin distributions compared to the 12 biannually treated communities that received six mass azithromycin distributions (odds ratio = 0.88, 95% confidence interval = 0.53 to 1.49.We were unable to demonstrate a statistically significant difference in stunting, underweight, and low MUAC of pre-school children in communities randomized to annual mass azithromycin treatment or biannual mass azithromycin treatment. The role of antibiotics on child growth and nutrition remains unclear, but larger studies and longitudinal trials may help determine any association.

  15. Mass and chemically speciated size distribution of Prague aerosol using an aerosol dryer - The influence of air mass origin

    Czech Academy of Sciences Publication Activity Database

    Schwarz, Jaroslav; Štefancová, Lucia; Maenhaut, W.; Smolík, Jiří; Ždímal, Vladimír

    2012-01-01

    Roč. 437, OCT 15 (2012), s. 348-362 ISSN 0048-9697 R&D Projects: GA ČR GA205/09/2055; GA ČR GAP209/11/1342; GA MŠk ME 941 Grant - others:SRF GU(BE) 01S01306 Institutional support: RVO:67985858 Keywords : atmospheric aerosols * mass size distribution * chemical composition Subject RIV: DI - Air Pollution ; Quality Impact factor: 3.258, year: 2012

  16. Nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.

    1989-01-01

    An introduction to nuclear fragmentation, with emphasis in percolation ideas, is presented. The main theoretical models are discussed and as an application, the uniform expansion approximation is presented and the statistical multifragmentation model is used to calculate the fragment energy spectra. (L.C.)

  17. Azimuthal Anisotropies in Nuclear Fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Szarska, M.; Trzupek, A.; Wolter, W.; Wosiek, B.

    2002-01-01

    The directed and elliptic flow of fragments emitted from the excited projectile nuclei has been observed for 158 AGeV Pb collisions with the lead and plastic targets. For comparison the flow analysis has been performed for 10.6 AGeV Au collisions with the emulsion target. The strong directed flow of heaviest fragments is found. Light fragments exhibit directed flow opposite to that of heavy fragments. The elliptic flow for all multiply charged fragments is positive and increases with the charge of the fragment. The observed flow patterns in the fragmentation of the projectile nucleus are practically independent of the mass of the target nucleus and the collision energy. Emission of fragments in nuclear multifragmentation shows similar, although weaker, flow effects. (author)

  18. Attitude dynamics and control of a spacecraft using shifting mass distribution

    Science.gov (United States)

    Ahn, Young Tae

    Spacecraft need specific attitude control methods that depend on the mission type or special tasks. The dynamics and the attitude control of a spacecraft with a shifting mass distribution within the system are examined. The behavior and use of conventional attitude control actuators are widely developed and performing at the present time. However, the advantage of a shifting mass distribution concept can complement spacecraft attitude control, save mass, and extend a satellite's life. This can be adopted in practice by moving mass from one tank to another, similar to what an airplane does to balance weight. Using this shifting mass distribution concept, in conjunction with other attitude control devices, can augment the three-axis attitude control process. Shifting mass involves changing the center-of-mass of the system, and/or changing the moments of inertia of the system, which then ultimately can change the attitude behavior of the system. This dissertation consists of two parts. First, the equations of motion for the shifting mass concept (also known as morphing) are developed. They are tested for their effects on attitude control by showing how shifting the mass changes the spacecraft's attitude behavior. Second, a method for optimal mass redistribution is shown using a combinatorial optimization theory under constraints. It closes with a simple example demonstrating an optimal reconfiguration. The procedure of optimal reconfiguration from one mass distribution to another to accomplish attitude control has been demonstrated for several simple examples. Mass shifting could work as an attitude controller for fine-tuning attitude behavior in small satellites. Various constraints can be applied for different situations, such as no mass shift between two tanks connected by a failed pipe or total amount of shifted mass per pipe being set for the time optimum solution. Euler angle changes influenced by the mass reconfiguration are accomplished while stability

  19. The Effect of Stiffness Parameter on Mass Distribution in Heavy-Ion Induced Fission

    Science.gov (United States)

    Soheyli, Saeed; Khalil Khalili, Morteza; Ashrafi, Ghazaaleh

    2018-06-01

    The stiffness parameter of the composite system has been studied for several heavy-ion induced fission reactions without the contribution of non-compound nucleus fission events. In this research, determination of the stiffness parameter is based on the comparison between the experimental data on the mass widths of fission fragments and those predicted by the statistical model treatments at the saddle and scission points. Analysis of the results shows that for the induced fission reactions of different targets by the same projectile, the stiffness parameter of the composite system decreases with increasing the fissility parameter, as well as with increasing the mass number of the compound nucleus. This parameter also exhibits a similar behavior for the reactions of a given target induced by different projectiles. As expected, nearly same stiffness values are obtained for different reactions leading to the same compound nucleus.

  20. Distribution of a Nocardia brasiliensis Catalase Gene Fragment in Members of the Genera Nocardia, Gordona, and Rhodococcus

    Science.gov (United States)

    Vera-Cabrera, Lucio; Johnson, Wendy M.; Welsh, Oliverio; Resendiz-Uresti, Francisco L.; Salinas-Carmona, Mario C.

    1999-01-01

    An immunodominant protein from Nocardia brasiliensis, P61, was subjected to amino-terminal and internal sequence analysis. Three sequences of 22, 17, and 38 residues, respectively, were obtained and compared with the protein database from GenBank by using the BLAST system. The sequences showed homology to some eukaryotic catalases and to a bromoperoxidase-catalase from Streptomyces violaceus. Its identity as a catalase was confirmed by analysis of its enzymatic activity on H2O2 and by a double-staining method on a nondenaturing polyacrylamide gel with 3,3′-diaminobenzidine and ferricyanide; the result showed only catalase activity, but no peroxidase. By using one of the internal amino acid sequences and a consensus catalase motif (VGNNTP), we were able to design a PCR assay that generated a 500-bp PCR product. The amplicon was analyzed, and the nucleotide sequence was compared to the GenBank database with the observation of high homology to other bacterial and eukaryotic catalases. A PCR assay based on this target sequence was performed with primers NB10 and NB11 to confirm the presence of the NB10-NB11 gene fragment in several N. brasiliensis strains isolated from mycetoma. The same assay was used to determine whether there were homologous sequences in several type strains from the genera Nocardia, Rhodococcus, Gordona, and Streptomyces. All of the N. brasiliensis strains presented a positive result but only some of the actinomycetes species tested were positive in the PCR assay. In order to confirm these findings, genomic DNA was subjected to Southern blot analysis. A 1.7-kbp band was observed in the N. brasiliensis strains, and bands of different molecular weight were observed in cross-reacting actinomycetes. Sequence analysis of the amplicons of selected actinomycetes showed high homology in this catalase fragment, thus demonstrating that this protein is highly conserved in this group of bacteria. PMID:10325357

  1. Penetration of Hydrogen clusters from 10 to 120 kev/u in carbon foils. Study of their slowing-down and charge distribution of emerging fragments

    International Nuclear Information System (INIS)

    Ray, E.M.

    1991-06-01

    This work is devoted to the experimental study of the interaction between fast (10 to 120 keV/p) hydrogen clusters with thin solid targets. First, we have studied the slowing-down of H n + (2≤n≤21) clusters through carbon foils. Up to date this had been made only with molecular ions. We obtain evidence for vicinage effects on the energy loss of proton-clusters. We show that for projectile energies larger than 50 keV/p, the energy loss of a proton in a cluster is enhanced when compared to that of an isolated proton of the same velocity. At lower incident energies, it is a decrease of the energy loss which is observed. The same effect is also observed in the energy lost in the entrance window of a surface barrier detector bombarded by clusters. This phenomenon is interpreted in terms of interferences between individual polarisation wakes induced by each proton of the cluster. In the second part, we propose an accurate method to study the charge state of the atomic fragments resulting from the dissociation of fast H n + (2≤n≤15) clusters through a carbon foil. This method gives also the distribution of the neutral atoms among the emerging fragments. These distributions are finally compared with binomial laws expected from independent particles

  2. Modeling The GRB Host Galaxy Mass Distribution: Are GRBs Unbiased Tracers of Star Formation?

    Energy Technology Data Exchange (ETDEWEB)

    Kocevski, Daniel; /KIPAC, Menlo Park; West, Andrew A.; /UC, Berkeley, Astron. Dept. /MIT, MKI; Modjaz, Maryam; /UC, Berkeley, Astron. Dept.

    2009-08-03

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity (M-Z) relationship for galaxies, along with a sharp host metallicity cut-off suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that sub-solar metallicity cut-offs effectively limit GRBs to low stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low metallicity cut-offs of 0.1 to 0.5 Z{sub {circle_dot}} are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H){sub KK04} = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z {approx} 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  3. MODELING THE GRB HOST GALAXY MASS DISTRIBUTION: ARE GRBs UNBIASED TRACERS OF STAR FORMATION?

    International Nuclear Information System (INIS)

    Kocevski, Daniel; West, Andrew A.; Modjaz, Maryam

    2009-01-01

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low-metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity relationship for galaxies, along with a sharp host metallicity cutoff suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that subsolar metallicity cutoffs effectively limit GRBs to low-stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low-metallicity cutoffs of 0.1 to 0.5 Z sun are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H) KK04 = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z ∼ 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity-biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  4. On-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry using Fab´antibody fragments for the analysis of serum transthyretin.

    Science.gov (United States)

    Pont, Laura; Benavente, Fernando; Barbosa, José; Sanz-Nebot, Victoria

    2017-08-01

    This paper describes an on-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry (IA-SPE-CE-MS) method using an immunoaffinity sorbent with Fab' antibody fragments (Fab'-IA) for the analysis of serum transthyretin (TTR), a homotetrameric protein (M r ~56,000) involved in different types of amyloidosis. The IA sorbent was prepared by covalent attachment of Fab' fragments obtained from a polyclonal IgG antibody against TTR to succinimidyl silica particles. The Fab'-IA-SPE-CE-MS methodology was first established analyzing TTR standard solutions. Under optimized conditions, repeatability and reproducibility were acceptable, the method was linear between 1 and 25µgmL -1 , limits of detection (LODs) were around 0.5µgmL -1 (50-fold lower than by CE-MS, ~25µgmL -1 ) and different TTR conformations were observed (folded and unfolded). The applicability of the developed method to screen for familial amyloidotic polyneuropathy type I (FAP-I), which is the most common hereditary systemic amyloidosis, was evaluated analyzing serum samples from healthy controls and FAP-I patients. For the analysis of sera, the most abundant proteins were precipitated with 5% (v/v) of phenol before Fab'-IA-SPE-CE-MS. The current method enhanced our previous results for the analysis of TTR using intact antibodies immobilized on magnetic beads. It allowed a slight improvement on LODs (2-fold), the detection of proteoforms found at lower concentrations and the preparation of microcartridges with extended durability. Copyright © 2017. Published by Elsevier B.V.

  5. Radar meteors range distribution model. II. Shower flux density and mass distribution index

    Czech Academy of Sciences Publication Activity Database

    Pecinová, Drahomíra; Pecina, Petr

    2007-01-01

    Roč. 37, č. 2 (2007), s. 107-124 ISSN 1335-1842 R&D Projects: GA ČR GA205/03/1405 Institutional research plan: CEZ:AV0Z10030501 Keywords : physics of meteors * radar meteors * range distribution Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  6. Physics of projectile fragments

    International Nuclear Information System (INIS)

    Minamisono, Tadanori

    1982-01-01

    This is a study report on the polarization phenomena of the projectile fragments produced by heavy ion reactions, and the beta decay of fragments. The experimental project by using heavy ions with the energy from 50 MeV/amu to 250 MeV/amu was designed. Construction of an angle-dispersion spectrograph for projectile fragments was proposed. This is a two-stage spectrograph. The first stage is a QQDQQ type separator, and the second stage is QDQD type. Estimation shows that Co-66 may be separated from the nuclei with mass of 65 and 67. The orientation of fragments can be measured by detecting beta-ray. The apparatus consists of a uniform field magnet, an energy absorber, a stopper, a RF coil and a beta-ray hodoscope. This system can be used for not only this purpose but also for the measurement of hyperfine structure. (Kato, T.)

  7. Mass and angular distributions of the reaction products in heavy ion collisions

    Science.gov (United States)

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Kayumov, B. M.; Tashkhodjaev, R. B.

    2018-05-01

    The optimal reactions and beam energies leading to synthesize superheavy elements is searched by studying mass and angular distributions of fission-like products in heavy-ion collisions since the evaporation residue cross section consists an ignorable small part of the fusion cross section. The intensity of the yield of fission-like products allows us to estimate the probability of the complete fusion of the interacting nuclei. The overlap of the mass and angular distributions of the fusion-fission and quasifission products causes difficulty at estimation of the correct value of the probability of the compound nucleus formation. A study of the mass and angular distributions of the reaction products is suitable key to understand the interaction mechanism of heavy ion collisions.

  8. Search for Z' --> e+ e- using dielectron mass and angular distribution.

    Science.gov (United States)

    Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cresciolo, F; Cruz, A; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciveres, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giokaris, N; Giolo, K; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Heijboer, A; Heinemann, B; Heinrich, J; Herndon, M; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Mitra, A; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spezziga, M; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

    2006-06-02

    We search for Z' bosons in dielectron events produced in pp collisions at square root of s = 1.96 TeV, using 0.45 fb(-1) of data accumulated with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. To identify the Z' --> e+ e- signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z' mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z', as well as on the contact-interaction mass scales for different helicity structure scenarios.

  9. Multiplicity and energy of neutrons from {sup 233}U(n{sub th},f) fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, Katsuhisa; Kimura, Itsuro; Nakagome, Yoshihiro [Kyoto Univ. (Japan)

    1998-03-01

    The correlation between fission fragments and prompt neutrons from the reaction {sup 233}U(n{sub th},f) was measured with improved accuracy. The results determined the neutron multiplicity and emission energy as a function of fragment mass and total kinetic energy. The average energy as a function of fragment mass followed a nearly symmetric distribution centered about the equal mass-split and formed a remarkable contrast with the saw-tooth distribution of the average neutron multiplicity. The neutron multiplicity from the specified fragment decreases linearly with total kinetic energy, and the slope of multiplicity with kinetic energy had the minimum value at about 130 u. The level density parameter versus mass determined from the neutron data showed a saw-tooth structure with the pronounced minimum at about 128 and generally followed the formula by Gilbert and Cameron, suggesting that the neutron emission process was very much affected by the shell-effect of the fission fragment. (author)

  10. Asymmetry distributions and mass effects in dijet-events at a polarized HERA

    CERN Document Server

    Maul, M; Mirkes, E; Rädel, G

    1998-01-01

    The asymmetry distributions for several kinematic variables are considered for finding a systematic way to maximize the signal for the extraction of the polarized gluon density. The relevance of mass effects for the corresponding dijet cross section is discussed and the different approximations for including mass effects are compared. We also compare via the programs PEPSI and MEPJET two different Monte Carlo (MC) approaches for simulating the expected signal in the dijet asymmetry at a polarized HERA.

  11. Gas puff radiation performance as a function of radial mass distribution

    International Nuclear Information System (INIS)

    Coleman, Philip L.; Krishnan, Mahadevan; Prasad, Rahul; Qi, Niansheng; Waisman, Eduardo; Failor, B.H.; Levine, J.S.; Sze, H.

    2002-01-01

    The basic concept of a z-pinch, that JxB forces implode a shell of mass, creating a hot dense plasma on-axis, is coming under closer scrutiny. Wire arrays may start with an initial cold mass in a near 'ideal' shell, but in fact they appear to develop complex radial mass distributions well before the final x-ray output. We consider here the situation for gas puff z-pinches. While the ideal of a gas 'shell' has been the nominal objective for many years, detailed measurements of gas flow show that nozzles used for plasma radiation sources (PRS) also have complex radial distributions. In particular, there are significant data showing that the best x-ray yield comes from the least shell-like distributions. Recent experiments on the Double Eagle generator with argon have further enhanced this view. For those tests with a double 'shell' nozzle, there was a factor of almost 4 increase in yield when the relative mass (outer:inner) in the two shells was changed from 2:1 to less than 1:1. We suggest the following explanation. A configuration with most of its mass at large radii is subject to severe disruption by instabilities during the implosion. A more continuous radial mass distribution with dρ/dr < 0 may mitigate instability development (via the 'snowplow stabilization' mechanism) and thus enhance the thermalization of the kinetic energy of the imploding mass. In addition, the appropriate balance of outer to inner mass maximizes the formation of a strong shock in the core of the pinch that heats the plasma and leads to x-ray emission

  12. The distribution of mass in the planetary system and solar nebulae

    International Nuclear Information System (INIS)

    Weidenschilling, S.J.

    1977-01-01

    A model 'solar nebula' is constructed by adding the solar complement of light elements to each planet, using recent models of planetary compositions. Uncertainties in this approach are estimated. The computed surface density varies approximately as rsup(-3/2). Mercury, Mars and the asteroid belt are anomalously low in mass, but processes exist which would preferentially remove matter from these regions. Planetary masses and compositions are generally consistent with a monotonic density distribution in the primordial solar nebula. (Auth.)

  13. Surface micro-distributions of pigment and the relation between smearing and local mass distribution

    International Nuclear Information System (INIS)

    Buelow, K.; Kristiansson, P.; Larsson, T.; Malmberg, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

    2001-01-01

    In this work, the process of smearing and its time evolution have been investigated. When smearing occurs, the print is removed from the printed paper and colours other parts of the paper or the printing press and destroys the final product. To study the re-distribution of ink, cyan ink with Cu as a tracer in the coloured pigment has been used. Non-printed paper has been pressed against the paper, 1 and 5 s after the printing. The micro-distributions of ink on both printed and non-printed papers have then been studied using particle-induced X-ray emission (PIXE). Basis weight was measured with the off-axis scanning transmission ion microscopy (STIM) technique and this data was correlated with the data from the print. One conclusion is that the process of smearing is not dependent on the shape of the pigment distribution, i.e. copper, or the content of copper in a specific pixel. On the contrary, the smearing was found to be related to the structure of the paper and that it mainly occurs where the paper is thicker

  14. Vibration Analysis of Inclined Laminated Composite Beams under Moving Distributed Masses

    Directory of Open Access Journals (Sweden)

    E. Bahmyari

    2014-01-01

    Full Text Available The dynamic response of laminated composite beams subjected to distributed moving masses is investigated using the finite element method (FEM based on the both first-order shear deformation theory (FSDT and the classical beam theory (CLT. Six and ten degrees of freedom beam elements are used to discretize the CLT and FSDT equations of motion, respectively. The resulting spatially discretized beam governing equations including the effect of inertial, Coriolis, and centrifugal forces due to moving distributed mass are evaluated in time domain by applying Newmark’s scheme. The presented approach is first validated by studying its convergence behavior and comparing the results with those of existing solutions in the literature. Then, the effect of incline angle, mass, and velocity of moving body, layer orientation, load length, and inertial, Coriolis, and centrifugal forces due to the moving distributed mass and friction force between the beam and the moving distributed mass on the dynamic behavior of inclined laminated composite beams are investigated.

  15. Mass resolved angular distribution of fission products in 20Ne + 232Th reaction

    International Nuclear Information System (INIS)

    Tripathi, R.; Sodaye, S.; Sudarshan, K.; Kumar, Amit; Guin, R.

    2011-01-01

    Mass resolved angular distribution of fission products was measured in 20 Ne + 232 Th reaction at beam energy of 120 MeV. A preliminary analysis of the angular distribution data of fission products shows higher average anisotropy compared to that calculated using statistical theory. A signature of rise in anisotropy near symmetry, as reported in earlier studies in literature, is also seen. Further study is in progress to get more detailed information about the contribution from non-compound nucleus fission and dependence of angular anisotropy on asymmetry of mass division

  16. Subchannel measurements of the equilibrium quality and mass flux distribution in a rod bundle

    International Nuclear Information System (INIS)

    Lahey, R.T. Jr.

    1986-01-01

    An experiment was performed to measure the equilibrium subchannel void and mass flux distribution in a simulated BWR rod bundle. These new equilibrium subchannel data are unique and represent an excellent basis for subchannel ''void drift'' model development and assessment. Equilibrium subchannel void and mass flux distributions have been determined from the data presented herein. While the form of these correlations agree with the results of previous theoretical investigations, they should be generalized with caution since the current data base has been taken at only one (low) system pressure. Clearly there is a need for equilibrium subchannel data at higher system pressures if mechanistic subchannel models are to be developed

  17. The effect of nuclear gas distribution on the mass determination of supermassive black holes

    Science.gov (United States)

    Mejía-Restrepo, J. E.; Lira, P.; Netzer, H.; Trakhtenbrot, B.; Capellupo, D. M.

    2018-01-01

    Supermassive black holes reside in the nuclei of most galaxies. During their active episodes, black holes are powered by accretion discs where gravitational energy is converted into radiation1. Accurately determining black hole masses is key to understand how the population evolves over time and how the black holes relate to their host galaxies2-4. Beyond the local universe, z ≳ 0.2, the mass is commonly estimated assuming a virialized motion of gas in the close vicinity of the active black holes, traced through broad emission lines5,6. However, this procedure has uncertainties associated with the unknown distribution of the gas clouds. Here, we show that the black hole masses derived from the properties of the accretion disk and virial mass estimates differ by a factor that is inversely proportional to the width of the broad emission lines. This leads to virial mass misestimations up to a factor of six. Our results suggest that a planar gas distribution that is inclined with respect to the line of sight may account for this effect. However, radiation pressure effects on the distribution of gas can also reproduce our results. Regardless of the physical origin, our findings contribute to mitigating the uncertainties in current black hole mass estimations and, in turn, will help us to better understand the evolution of distant supermassive black holes and their host galaxies.

  18. Gas-phase behaviour of Ru(II) cyclopentadienyl-derived complexes with N-coordinated ligands by electrospray ionization mass spectrometry: fragmentation pathways and energetics.

    Science.gov (United States)

    Madeira, Paulo J Amorim; Morais, Tânia S; Silva, Tiago J L; Florindo, Pedro; Garcia, M Helena

    2012-08-15

    The gas-phase behaviour of six Ru(II) cyclopentadienyl-derived complexes with N-coordinated ligands, compounds with antitumor activities against several cancer lines, was studied. This was performed with the intent of establishing fragmentation pathways and to determine the Ru-L(N) and Ru-L(P) ligand bond dissociation energies. Such knowledge can be an important tool for the postulation of the mechanisms of action of these anticancer drugs. Two types of instruments equipped with electrospray ionisation were used (ion trap and a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer). The dissociation energies were determined using energy-variable collision-induced dissociation measurements in the ion trap. The FTICR instrument was used to perform MS(n) experiments on one of the compounds and to obtain accurate mass measurements. Theoretical calculations were performed at the density functional theory (DFT) level using two different functionals (B3LYP and M06L) to estimate the dissociation energies of the complexes under study. The influence of the L(N) on the bond dissociation energy (D) of RuCp compounds with different nitrogen ligands was studied. The lability order of L(N) was: imidazole<1-butylimidazole<5-phenyl-1H-tetrazole<1-benzylimidazole. Both the functionals used gave the following ligand lability order: imidazole<1-benzylimidazole<5-phenyl-1H-tetrazole<1-butylimidazole. It is clear that there is an inversion between 1-benzylimidazole and 1-butylimidazole for the experimental and theoretical lability orders. The M06L functional afforded values of D closer to the experimental values. The type of phosphane (L(P) ) influenced the dissociation energies, with values of D being higher for Ru-L(N) with 1-butylimidazole when the phosphane was 1,2-bis(diphenylphosphino)ethane. The Ru-L(P) bond dissociation energy for triphenylphosphane was independent of the type of complex. The D values of Ru-L(N) and Ru-L(P) were determined for all six compounds and

  19. Mass exchange and angular distribution in a dynamical treatment of heavy ion collisions

    International Nuclear Information System (INIS)

    Ngo, C.; Hofmann, H.

    1977-01-01

    One presents a first numerical computation of the absolute value of the double differential cross section as a function of mass asymmetry and detection angle including a dynamical coupling between relative motion and mass asymmetry. One applies it to the 63 Cu+ 197 Au experiment at two different energies. The equation of motion used is a Fokker-Planck equation for distribution function in classical phase space. The coefficients needed are those known from classical model calculations, besides a friction coefficient introduced for the mass asymmetry degree. Encouraging agreement between the calculated and experimental curves is found

  20. Present and future isochronous mass spectrometry at GSI-FAIR. 25 new masses of fission fragments novel analysis method design of a new time-of-flight detector system

    Energy Technology Data Exchange (ETDEWEB)

    Diwisch, Marcel

    2015-07-01

    In this work the basic features of isochronous mass spectroscopy (IMS) for the present facilities at GSI and also for the future experiments at FAIR have been experimentally and theoretically investigated. The prospects and limitations of IMS have been carefully studied with calculations and experiments. The data of two different previous IMS experiments at GSI have been combined and analyzed with a novel correlation-matrix method (CMM). Both experiments were performed with the fragment separator FRS and the experimental ion storage ring ESR. In both experiments fission fragments, created by {sup 238}U projectiles in a beryllium target at the entrance of the FRS, were spatially separated and injected into the isochronous ESR. In the first experiment the full Bρ acceptance of the ESR was used whereas in the second one the Bρ of each fragment was defined by slits in the dispersive central focal plane of the FRS. In this way the magnetic rigidity was well-determined for all injected fragments to ΔBρ/Bρ=1.5.10{sup -4}. The harvest of this analysis is 25 new masses near and at the N=82 shell closure. The comparison of the experimental results with the AME extrapolation and different theoretical models reveal significant differences due to the low theoretical prediction power of the calculations in this mass range. In this respect one has to emphasize that due to the novel analysis method in this work these 25 new masses could be extracted additional to our previously already published results. It is almost needless to mention that the new mass values will contribute to improved r-process calculations which are in progress. In the present analysis the existing matrix method was extended with a variable scaling factor (s). The scaling factor was determined for each mass-to-charge ratio (m/q) of the measured ions and implemented as a function of m/q in the analysis. This has extended the accessible m/q range. The revolution time was determined via a 3rd-order fit of

  1. Present and future isochronous mass spectrometry at GSI-FAIR. 25 new masses of fission fragments novel analysis method design of a new time-of-flight detector system

    International Nuclear Information System (INIS)

    Diwisch, Marcel

    2015-01-01

    In this work the basic features of isochronous mass spectroscopy (IMS) for the present facilities at GSI and also for the future experiments at FAIR have been experimentally and theoretically investigated. The prospects and limitations of IMS have been carefully studied with calculations and experiments. The data of two different previous IMS experiments at GSI have been combined and analyzed with a novel correlation-matrix method (CMM). Both experiments were performed with the fragment separator FRS and the experimental ion storage ring ESR. In both experiments fission fragments, created by 238 U projectiles in a beryllium target at the entrance of the FRS, were spatially separated and injected into the isochronous ESR. In the first experiment the full Bρ acceptance of the ESR was used whereas in the second one the Bρ of each fragment was defined by slits in the dispersive central focal plane of the FRS. In this way the magnetic rigidity was well-determined for all injected fragments to ΔBρ/Bρ=1.5.10 -4 . The harvest of this analysis is 25 new masses near and at the N=82 shell closure. The comparison of the experimental results with the AME extrapolation and different theoretical models reveal significant differences due to the low theoretical prediction power of the calculations in this mass range. In this respect one has to emphasize that due to the novel analysis method in this work these 25 new masses could be extracted additional to our previously already published results. It is almost needless to mention that the new mass values will contribute to improved r-process calculations which are in progress. In the present analysis the existing matrix method was extended with a variable scaling factor (s). The scaling factor was determined for each mass-to-charge ratio (m/q) of the measured ions and implemented as a function of m/q in the analysis. This has extended the accessible m/q range. The revolution time was determined via a 3rd-order fit of the time

  2. Studies of nontarget-mediated distribution of human full-length IgG1 antibody and its FAb fragment in cardiovascular and metabolic-related tissues.

    Science.gov (United States)

    Davidsson, Pia; Söderling, Ann-Sofi; Svensson, Lena; Ahnmark, Andrea; Flodin, Christine; Wanag, Ewa; Screpanti-Sundqvist, Valentina; Gennemark, Peter

    2015-05-01

    Tissue distribution and pharmacokinetics (PK) of full-length nontargeted antibody and its antigen-binding fragment (FAb) were evaluated for a range of tissues primarily of interest for cardiovascular and metabolic diseases. Mice were intravenously injected with a dose of 10 mg/kg of either human IgG1or its FAb fragment; perfused tissues were collected at a range of time points over 3 weeks for the human IgG1 antibody and 1 week for the human FAb antibody. Tissues were homogenized and antibody concentrations were measured by specific immunoassays on the Gyros system. Exposure in terms of maximum concentration (Cmax ) and area under the curve was assessed for all nine tissues. Tissue exposure of full-length antibody relative to plasma exposure was found to be between 1% and 10%, except for brain (0.2%). Relative concentrations of FAb antibody were the same, except for kidney tissue, where the antibody concentration was found to be ten times higher than in plasma. However, the absolute tissue uptake of full-length IgG was significantly higher than the absolute tissue uptake of the FAb antibody. This study provides a reference PK state for full-length whole and FAb antibodies in tissues related to cardiovascular and metabolic diseases that do not include antigen or antibody binding. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  3. Tandem mass spectrometry approach for the investigation of the steroidal metabolism: structure-fragmentation relationship (SFR) in anabolic steroids and their metabolites by ESI-MS/MS analysis.

    Science.gov (United States)

    Musharraf, Syed Ghulam; Ali, Arslan; Khan, Naik Tameem; Yousuf, Maria; Choudhary, Muhammad Iqbal; Atta-ur-Rahman

    2013-02-01

    Electrospray ionization tandem mass spectrometry (ESI-MS/MS) was used to investigate the effect of different substitutions introduced during metabolism on fragmentation patterns of four anabolic steroids including methyltestosterone, methandrostenolone, cis-androsterone and adrenosterone, along with their metabolites. Collision-induced dissociation (CID) analysis was performed to correlate the major product ions of 19 steroids with structural features. The analysis is done to portray metabolic alteration, such as incorporation or reduction of double bonds, hydroxylations, and/or oxidation of hydroxyl moieties to keto functional group on steroidal skeleton which leads to drastically changed product ion spectra from the respective classes of steroids, therefore, making them difficult to identify. The comparative ESI-MS/MS study also revealed some characteristic peaks to differentiate different steroidal metabolites and can be useful for the unambiguous identification of anabolic steroids in biological fluid. Moreover, LC-ESI-MS/MS analysis of fermented extract of methyltestosterone, obtained by Macrophomina phaseolina was also investigated. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Physical conditions, dynamics and mass distribution in the center of the galaxy

    Science.gov (United States)

    Genzel, R.; Townes, C. H.

    1987-01-01

    Investigations of the central 10 pc of the Galaxy, and conclusions on energetics, dynamics, and mass distribution derived from X and gamma ray measurements and from infrared and microwave studies, especially from spectroscopy, high resolution imaging, and interferometry are reviewed. Evidence for and against a massive black hole is analyzed.

  5. The dijet mass spectrum and angular distributions with the D0 detector

    International Nuclear Information System (INIS)

    Abachi, S.

    1996-07-01

    We present preliminary results from an analysis of dijet data collected during the 1994-95 Tevatron Collider run with an integrated luminosity of 91 pb -1 . Measurements of dijet mass spectra and dijet angular distributions in anti pp collisions at √s- = 1.8 TeV are compared with next-to-leading order QCD theory

  6. Analysis for mass distribution of proton-induced reactions in intermediate energy range

    CERN Document Server

    Xiao Yu Heng

    2002-01-01

    The mass and charge distribution of residual products produced in the spallation reactions needs to be studied, because it can provide useful information for the disposal of nuclear waste and residual radioactivity generated by the spallation neutron target system. In present work, the Many State Dynamical Model (MSDM) is based on the Cascade-Exciton Model (CEM). The authors use it to investigate the mass distribution of Nb, Au and Pb proton-induced reactions in energy range from 100 MeV to 3 GeV. The agreement between the MSDM simulations and the measured data is good in this energy range, and deviations mainly show up in the mass range of 90 - 150 for the high energy proton incident upon Au and Pb

  7. The link between the baryonic mass distribution and the rotation curve shape

    Science.gov (United States)

    Swaters, R. A.; Sancisi, R.; van der Hulst, J. M.; van Albada, T. S.

    2012-09-01

    The observed rotation curves of disc galaxies, ranging from late-type dwarf galaxies to early-type spirals, can be fitted remarkably well simply by scaling up the contributions of the stellar and H I discs. This 'baryonic scaling model' can explain the full breadth of observed rotation curves with only two free parameters. For a small fraction of galaxies, in particular early-type spiral galaxies, H I scaling appears to fail in the outer parts, possibly due to observational effects or ionization of H I. The overall success of the baryonic scaling model suggests that the well-known global coupling between the baryonic mass of a galaxy and its rotation velocity (known as the baryonic Tully-Fisher relation) applies at a more local level as well, and it seems to imply a link between the baryonic mass distribution and the distribution of total mass (including dark matter).

  8. Dependence of black fragment azimuthal and projected angular distributions on polar angle in silicon-emulsion collisions at 4.5A GeV/c

    International Nuclear Information System (INIS)

    Liu Fuhu; Abd Allah, Nabil N.; Singh, B.K.

    2004-01-01

    The experimental results of dependence of black fragment azimuth (φ) and projected angle (ψ) distributions on polar angle θ in silicon-emulsion collisions at 4.5A GeV/c (the Dubna momentum) are reported. There are two regions of enhancement around φ=±90 deg. for different θ ranges. These enhancements are due to directed (v 1 ) and elliptic (v 2 ) flows. The v 1 and v 2 dependence of values on θ shows that the directed flow is weak and the elliptic flow is strong in these collisions. A multisource ideal gas model is used to describe the experimental results of dependence. The Monte Carlo calculated results are approximately in agreement with the experimental data

  9. The distribution of mass for spiral galaxies in clusters and in the field

    International Nuclear Information System (INIS)

    Forbes, D.A.; Whitmore, B.C.

    1989-01-01

    A comparison is made between the mass distributions of spiral galaxies in clusters and in the field using Burstein's mass-type methodology. Both the H-alpha emission-line rotation curves and more extended H I rotation curves are used. The fitting technique for determining mass types used by Burstein and coworkers has been replaced by an objective chi-sq method. Mass types are shown to be a function of both the Hubble type and luminosity, contrary to earlier results. The present data show a difference in the distribution of mass types for spiral galaxies in the field and in clusters, in the sense that mass type I galaxies, where the inner and outer velocity gradients are similar, are generally found in the field rather than in clusters. This can be understood in terms of the results of Whitmore, Forbes, and Rubin (1988), who find that the rotation curves of galaxies in the central region of clusters are generally failing, while the outer galaxies in a cluster and field galaxies tend to have flat or rising rotation curves. 15 refs

  10. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Energy Technology Data Exchange (ETDEWEB)

    Dai, De-Chang, E-mail: diedachung@gmail.com [Institute of Natural Sciences, Shanghai Key Lab for Particle Physics and Cosmology, and Center for Astrophysics and Astronomy, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Stojkovic, Dejan [HEPCOS, Department of Physics, SUNY, University at Buffalo, Buffalo, NY 14260-1500 (United States)

    2016-07-10

    Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  11. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Directory of Open Access Journals (Sweden)

    De-Chang Dai

    2016-07-01

    Full Text Available Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  12. Calculating the mass distribution of heavy nucleus fission product by neutrons

    International Nuclear Information System (INIS)

    Gudkov, A.N.; Koldobskij, A.B.; Kolobashkin, V.M.; Semenova, E.V.

    1981-01-01

    The technique of calculating the fission product mass yields by neutrons which are necessary for performing nucleus physical calculations in designing nuclear reactor cores is considered. The technique is based on the approximation of fission product mass distribution over the whole mass range by five Gauss functions. New analytical expressions for determining energy weights of used gaussians are proposed. The results of comparison of experimental data with calculated values for fission product mass obtained for reference processes in the capacity of which the fission reactions are chosen: 233 U, 235 U fission by thermal neutrons, 232 Th, 233 U, 235 U, 238 U by fission spectrum neutrons and 14 MeV neutrons and for 232 Th fission reactions by 11 MeV neutrons and 238 U by 7.7 MeV neutrons. On the basis of the analysis of results obtained the conclusion is drawn on a good agreement of fission product mass yield calculation values obtained using recommended values of mass distribution parameters with experimental data [ru

  13. Throwing behavior and mass distribution of stone selection in tufted capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Cleveland, A; Rocca, A R; Wendt, E L; Westergaard, G C

    2003-12-01

    Cannell [Journal of Archaeological Science 29:335-339, 2002] argued that sex-based differences among humans in terms of the mass of chosen throwing stones could be used to infer body mass and patterns of sexual dimorphism in early hominids from Olduvai and Koobi Fora by examining the mass distributions of unaltered stone tools at those sites. We examined this hypothesis in tufted capuchin monkeys using a comparative approach, by investigating the relationships among body mass, sex, stone weight preference, and accuracy in a throwing task. The subject sample consisted of nine monkeys trained to perform an aimed-throwing task in which a food reward could be obtained by throwing a stone into a bucket. We found that 1) the subjects showed a strong mean stone mass preference; 2) the females chose heavier stones than the males, in terms of absolute mean selected stone mass and selected stone mass relative to body mass; 3) subjects threw more accurately when they used stones of preferred mass vs. stones of nonpreferred mass; and 4) overall, the males were more accurate in the throwing task than the females. We conclude that capuchins are highly selective when choosing throwing stones, and that this confers an advantage for throwing accuracy. Our results indicate that the sexually dimorphic pattern in stone mass preference observed among humans does not generalize to Cebus apella. We suggest that researchers examining this pattern in humans in an attempt to explain early hominid patterns of dimorphism and behavior should take into account not only stone weight preference, but also its adaptive advantage. Copyright 2003 Wiley-Liss, Inc.

  14. Impact of fat mass distribution body shapes on muscles strength and the joints pain

    Directory of Open Access Journals (Sweden)

    Zerf Mohammed

    2016-01-01

    Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

  15. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  16. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  17. POPULATION STRUCTURE AND SPATIAL DISTRIBUTION OF Bauhinia cheilantha (Bong. Steud. IN TWO FRAGMENTS AT DIFFERENT REGENERATION STAGES IN THE CAATINGA, IN SERGIPE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Ana Cecília da Cruz Silva

    2015-06-01

    Full Text Available ABSTRACTThis study aimed to analyze the vertical and diameter structure and the spatial distribution pattern of Bauhinia cheilantha in two Caatinga fragments in Sergipe, Brazil, at different regeneration stages. Thirty plots were demarcated in area I (Canindé de São Francisco and Poço Redondo, which has vegetation regeneration, and 25 plots in area II (Porto da Folha with preserved vegetation, both having 400 m2. All B. cheilanthaindividuals had their height and circumference (circumference at breast height > 6 cm measured. Possible differences in height and diameter at breast height were tested in the two populations by using Student’s T-test. The distribution pattern of species was calculated through Payandeh’s index. We sampled 154 B. cheilantha individuals, equivalent to 33.3% of the plots in area I and in 1,027 individuals in area II, totaling 100% frequency. Height and the diameter of the two populations were statistically different, where AI achieved all values lower than AII. The spatial distribution pattern of B. cheilantha found in both areas was aggregate, with values of 11.85 and 9.00, respectively. Thus, it became clear that the population in AII is at a more advanced successional status than AI, due to its longer conservation time.

  18. String fragmentation; La fragmentation des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Laboratoire de Physique Subatomique et des Technologies Associees - SUBATECH, Centre National de la Recherche Scientifique, 44 - Nantes (France)

    1997-10-01

    The classical string model is used in VENUS as a fragmentation model. For the soft domain simple 2-parton strings were sufficient, whereas for higher energies up to LHC, the perturbative regime of the QCD gives additional soft gluons, which are mapped on the string as so called kinks, energy singularities between the leading partons. The kinky string model is chosen to handle fragmentation of these strings by application of the Lorentz invariant area law. The `kinky strings` model, corresponding to the perturbative gluons coming from pQCD, takes into consideration this effect by treating the partons and gluons on the same footing. The decay law is always the Artru-Menessier area law which is the most realistic since it is invariant to the Lorentz and gauge transformations. For low mass strings a manipulation of the rupture point is necessary if the string corresponds already to an elementary particle determined by the mass and the flavor content. By means of the fragmentation model it will be possible to simulate the data from future experiments at LHC and RHIC 3 refs.

  19. Free Vibrations of a Cantilevered SWCNT with Distributed Mass in the Presence of Nonlocal Effect

    Directory of Open Access Journals (Sweden)

    M. A. De Rosa

    2015-01-01

    Full Text Available The Hamilton principle is applied to deduce the free vibration frequencies of a cantilever single-walled carbon nanotube (SWCNT in the presence of an added mass, which can be distributed along an arbitrary part of the span. The nonlocal elasticity theory by Eringen has been employed, in order to take into account the nanoscale effects. An exact formulation leads to the equations of motion, which can be solved to give the frequencies and the corresponding vibration modes. Moreover, two approximate semianalytical methods are also illustrated, which can provide quick parametric relationships. From a more practical point of view, the problem of detecting the mass of the attached particle has been solved by calculating the relative frequency shift due to the presence of the added mass: from it, the mass value can be easily deduced. The paper ends with some numerical examples, in which the nonlocal effects are thoroughly investigated.

  20. Fractal statistics of brittle fragmentation

    Directory of Open Access Journals (Sweden)

    M. Davydova

    2013-04-01

    Full Text Available The study of fragmentation statistics of brittle materials that includes four types of experiments is presented. Data processing of the fragmentation of glass plates under quasi-static loading and the fragmentation of quartz cylindrical rods under dynamic loading shows that the size distribution of fragments (spatial quantity is fractal and can be described by a power law. The original experimental technique allows us to measure, apart from the spatial quantity, the temporal quantity - the size of time interval between the impulses of the light reflected from the newly created surfaces. The analysis of distributions of spatial (fragment size and temporal (time interval quantities provides evidence of obeying scaling laws, which suggests the possibility of self-organized criticality in fragmentation.

  1. Reassessment of fission fragment angular distributions from continuum states in the context of transition-state theory

    International Nuclear Information System (INIS)

    Vaz, L.C.; Alexander, J.M.

    1983-01-01

    Fission angular distributions have been studied for years and have been treated as classic examples of transition-state theory. Early work involving composite nuclei of relatively low excitation energy Esup(*) ( 2 0 (K 2 0 = Psub(eff)T/(h/2π) 2 ) are presented along with comparissons of Psub(eff) to moments of inertia for saddle-point nuclei from the rotating liquid drop model. This model gives an excellent guide for the intermediate spin zone (30 < or approx. I < or approx. 65), while strong shell and/or pairing effects are evident for excitations less than < or approx. 35 MeV. Observations of strong anisotropies for very high-spin systems signal the demise of certain approximations commonly made in the theory, and suggestions are made toward this end. (orig.)

  2. Fission mass yields of excited medium heavy nuclei

    International Nuclear Information System (INIS)

    Sandulescu, A.; Depta, K.; Herrmann, R.; Greiner, W.; Scheid, W.

    1985-01-01

    The mass distributions resulting from the fission of excited medium mass nuclei are discussed on the basis of the fragmentation theory. It is shown that very asymmetric fission events can be expected with rates which are only a few orders of magnitude smaller than the rates for symmetric fission. As an example a calculation of the fission mass distribution of the excited 172 Yb compound nucleus is presented. This mass distribution reveals observable structures over the entire range of the mass asymmetry due to valleys in the potential energy surface for fission fragments with closed proton and neutron shells

  3. Angular correlation between the heavy fragments and the light charged particles in tripartition of 236U and 252Cf

    International Nuclear Information System (INIS)

    Sowinski, M.

    1975-05-01

    The energy distributions and relative intensities of protons, deuterons, tritons and alpha-particles emitted along the fission axis during thermal neutron fission of 236 U are measured simultaneously with the energies of the two fission fragments. The mass distributions of the fragments, the total kinetic energy (TKE), the dependence of the mean TKE on the fragment mass, as well as the mean kinetic energy dependence of polar particles on the fragment mass and energy are deduced from these data. Although some experimental results agree remarkably well with the hypothesis that polar particles are evaporated in-flight from fission fragments, the general conclusion is that these particles are emitted according to some other mechanism

  4. Core-powered mass-loss and the radius distribution of small exoplanets

    Science.gov (United States)

    Ginzburg, Sivan; Schlichting, Hilke E.; Sari, Re'em

    2018-05-01

    Recent observations identify a valley in the radius distribution of small exoplanets, with planets in the range 1.5-2.0 R⊕ significantly less common than somewhat smaller or larger planets. This valley may suggest a bimodal population of rocky planets that are either engulfed by massive gas envelopes that significantly enlarge their radius, or do not have detectable atmospheres at all. One explanation of such a bimodal distribution is atmospheric erosion by high-energy stellar photons. We investigate an alternative mechanism: the luminosity of the cooling rocky core, which can completely erode light envelopes while preserving heavy ones, produces a deficit of intermediate sized planets. We evolve planetary populations that are derived from observations using a simple analytical prescription, accounting self-consistently for envelope accretion, cooling and mass-loss, and demonstrate that core-powered mass-loss naturally reproduces the observed radius distribution, regardless of the high-energy incident flux. Observations of planets around different stellar types may distinguish between photoevaporation, which is powered by the high-energy tail of the stellar radiation, and core-powered mass-loss, which depends on the bolometric flux through the planet's equilibrium temperature that sets both its cooling and mass-loss rates.

  5. Fragmentation of relativistic nuclei

    International Nuclear Information System (INIS)

    Cork, B.

    1975-06-01

    Nuclei with energies of several GeV/n interact with hadrons and produce fragments that encompass the fields of nuclear physics, meson physics, and particle physics. Experimental results are now available to explore problems in nuclear physics such as the validity of the shell model to explain the momentum distribution of fragments, the contribution of giant dipole resonances to fragment production cross sections, the effective Coulomb barrier, and nuclear temperatures. A new approach to meson physics is possible by exploring the nucleon charge-exchange process. Particle physics problems are explored by measuring the energy and target dependence of isotope production cross sections, thus determining if limiting fragmentation and target factorization are valid, and measuring total cross sections to determine if the factorization relation, sigma/sub AB/ 2 = sigma/sub AA/ . sigma/sub BB/, is violated. Also, new experiments have been done to measure the angular distribution of fragments that could be explained as nuclear shock waves, and to explore for ultradense matter produced by very heavy ions incident on heavy atoms. (12 figures, 2 tables)

  6. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2017-01-01

    The PhD project Bespoke Fragments is investigating the space emerging in the exploration of the relationship between digital drawing and fabrication, and the field of materials and their properties and capacities. Through a series of different experiments, the project situates itself in a shuttli...

  7. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  8. Teacher candidates' mastery of phoneme-grapheme correspondence: massed versus distributed practice in teacher education.

    Science.gov (United States)

    Sayeski, Kristin L; Earle, Gentry A; Eslinger, R Paige; Whitenton, Jessy N

    2017-04-01

    Matching phonemes (speech sounds) to graphemes (letters and letter combinations) is an important aspect of decoding (translating print to speech) and encoding (translating speech to print). Yet, many teacher candidates do not receive explicit training in phoneme-grapheme correspondence. Difficulty with accurate phoneme production and/or lack of understanding of sound-symbol correspondence can make it challenging for teachers to (a) identify student errors on common assessments and (b) serve as a model for students when teaching beginning reading or providing remedial reading instruction. For students with dyslexia, lack of teacher proficiency in this area is particularly problematic. This study examined differences between two learning conditions (massed and distributed practice) on teacher candidates' development of phoneme-grapheme correspondence knowledge and skills. An experimental, pretest-posttest-delayed test design was employed with teacher candidates (n = 52) to compare a massed practice condition (one, 60-min session) to a distributed practice condition (four, 15-min sessions distributed over 4 weeks) for learning phonemes associated with letters and letter combinations. Participants in the distributed practice condition significantly outperformed participants in the massed practice condition on their ability to correctly produce phonemes associated with different letters and letter combinations. Implications for teacher preparation are discussed.

  9. Large-Scale Ichthyoplankton and Water Mass Distribution along the South Brazil Shelf

    Science.gov (United States)

    de Macedo-Soares, Luis Carlos Pinto; Garcia, Carlos Alberto Eiras; Freire, Andrea Santarosa; Muelbert, José Henrique

    2014-01-01

    Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27′ and 34°51′S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients. PMID:24614798

  10. Large-scale ichthyoplankton and water mass distribution along the South Brazil Shelf.

    Directory of Open Access Journals (Sweden)

    Luis Carlos Pinto de Macedo-Soares

    Full Text Available Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27' and 34°51'S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients.

  11. Large-scale ichthyoplankton and water mass distribution along the South Brazil Shelf.

    Science.gov (United States)

    de Macedo-Soares, Luis Carlos Pinto; Garcia, Carlos Alberto Eiras; Freire, Andrea Santarosa; Muelbert, José Henrique

    2014-01-01

    Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27' and 34°51'S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients.

  12. System effectiveness of a targeted free mass distribution of long lasting insecticidal nets in Zanzibar, Tanzania

    Directory of Open Access Journals (Sweden)

    Abass Ali K

    2010-06-01

    Full Text Available Abstract Background Insecticide-treated nets (ITN and long-lasting insecticidal treated nets (LLIN are important means of malaria prevention. Although there is consensus regarding their importance, there is uncertainty as to which delivery strategies are optimal for dispensing these life saving interventions. A targeted mass distribution of free LLINs to children under five and pregnant women was implemented in Zanzibar between August 2005 and January 2006. The outcomes of this distribution among children under five were evaluated, four to nine months after implementation. Methods Two cross-sectional surveys were conducted in May 2006 in two districts of Zanzibar: Micheweni (MI on Pemba Island and North A (NA on Unguja Island. Household interviews were conducted with 509 caretakers of under-five children, who were surveyed for socio-economic status, the net distribution process, perceptions and use of bed nets. Each step in the distribution process was assessed in all children one to five years of age for unconditional and conditional proportion of success. System effectiveness (the accumulated proportion of success and equity effectiveness were calculated, and predictors for LLIN use were identified. Results The overall proportion of children under five sleeping under any type of treated net was 83.7% (318/380 in MI and 91.8% (357/389 in NA. The LLIN usage was 56.8% (216/380 in MI and 86.9% (338/389 in NA. Overall system effectiveness was 49% in MI and 87% in NA, and equity was found in the distribution scale-up in NA. In both districts, the predicting factor of a child sleeping under an LLIN was caretakers thinking that LLINs are better than conventional nets (OR = 2.8, p = 0.005 in MI and 2.5, p = 0.041 in NA, in addition to receiving an LLIN (OR = 4.9, p Conclusions Targeted free mass distribution of LLINs can result in high and equitable bed net coverage among children under five. However, in order to sustain high effective coverage, there

  13. Determination of isotope ratio of elements by mass distribution in molecules of varied chemical compounds

    International Nuclear Information System (INIS)

    Gladkikh, I.S.; Babichev, A.P.

    1999-01-01

    The procedure and program for calculation of isotope ratio of elements involving in the compound being studied using data of mass spectrometry were elaborated. The methods developed for the O 2 , SiH 4 , Cd(CH 3 ) 2 molecules were demonstrated for the illustration. The results of calculation provide support for the efficiency of the program and satisfactory reliability of the results during calculation of the isotope and complex compound concentrations. The program may be used for the estimation of the degree of nonequilibrium isotope distributions, it may indicate on the errors of the mass spectroscopy results [ru

  14. Generalized conditions for the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space

    International Nuclear Information System (INIS)

    Manoukian, E.B.

    1986-01-01

    Generalized conditions (rules) are set up for the existence of the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space. These rules are generalizations of rules that have been set up earlier by us and hence are applicable to a larger class of graphs. The study is very general as the vanishing masses are led to vanish at different rates. All subtractions of renormalization are carried out directly in momentum space, about the origin, with the degree of divergence of a subtraction coinciding with the dimensionality of the corresponding subdiagram

  15. Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Maganas, A.

    1993-01-01

    An experiment was designed to measure the fully-developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a BWR-5 rod bundle. Data collected with Refrigerant-144 at pressures ranging from 7 to 14 bar, simulating operation with water in the range 55 to 103 bar are reported. The average mass flux and quality in the test section were in the ranges 1300 to 1750 kg/m s and -0.03 to 0.25, respectively. The data are analyzed and presented in various forms

  16. Mid-winter European dabbling duck distributions are not linked to species body mass

    DEFF Research Database (Denmark)

    Dalby, Lars; Delany, Simon; Fox, Anthony David

    are likely to play a major role in determining the wintering distribution of short- to medium-distance migratory bird species and its inter-annual variability. As avian thermoregulatory costs scale allometrically with body size, we predicted that the mean mid-winter temperature experienced by six species...... of dabbling ducks wintering in Western Europe would be negatively correlated with body mass. We found no evidence for such a relationship in a large-scale analysis testing for a link between temperature and dabbling duck distributions, suggesting that other factors such as those related to feeding ecology......In order to understand the current changes and to predict future changes in wintering dabbling duck (Anas sp.) distributions in response to climate change, it is important to understand how species distribute themselves on a continental scale in response to temperature. Thermoregulatory costs...

  17. Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

    Science.gov (United States)

    García-Ibáñez, Maribel I.; Pérez, Fiz F.; Lherminier, Pascale; Zunino, Patricia; Mercier, Herlé; Tréguer, Paul

    2018-04-01

    We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP) analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW) dominated the upper part of the GEOTRACES-GA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland-Scotland Overflow Water (ISOW) and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section) by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014 OVIDE line and the 2002-2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002-2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002-2010, with the increase being consistent with other estimates of ISOW transports along 58-59° N. We also observed an increase in SPMW in the East Greenland Irminger Current in 2014 with respect to 2002-2010, which supports the recent deep convection events in the Irminger Sea. From the assessment of the relative water mass contribution to the Atlantic Meridional Overturning Circulation (AMOC) across the OVIDE line, we conclude that the larger AMOC intensity in

  18. Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

    Directory of Open Access Journals (Sweden)

    M. I. García-Ibáñez

    2018-04-01

    Full Text Available We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW dominated the upper part of the GEOTRACES-GA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland–Scotland Overflow Water (ISOW and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014 OVIDE line and the 2002–2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002–2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002–2010, with the increase being consistent with other estimates of ISOW transp