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Sample records for chandrasekhar mass limit

  1. White dwarf stars exceeding the Chandrasekhar mass limit

    Science.gov (United States)

    Tomaschitz, Roman

    2018-01-01

    The effect of nonlinear ultra-relativistic electron dispersion on the mass-radius relation of high-mass white dwarfs is studied. The dispersion is described by a permeability tensor in the Dirac equation, generated by the ionized high-density stellar matter, which constitutes the neutralizing background of the nearly degenerate electron plasma. The electron dispersion results in a stable mass-radius relation for high-mass white dwarfs, in contrast to a mass limit in the case of vacuum permeabilities. In the ultra-relativistic regime, the dispersion relation is a power law whose amplitude and scaling exponent is inferred from mass and radius estimates of two high-mass white dwarfs, Sirius B and LHS 4033. Evidence for the existence of super-Chandrasekhar mass white dwarfs is provided by several Type Ia supernovae (e.g., SN 2013cv, SN 2003fg, SN 2007if and SN 2009dc), whose mass ejecta exceed the Chandrasekhar limit by up to a factor of two. The dispersive mass-radius relation is used to estimate the radii, central densities, Fermi temperatures, bulk and compression moduli and sound velocities of their white dwarf progenitors.

  2. Chandrasekhar Limit: An Elementary Approach Based on Classical Physics and Quantum Theory

    Science.gov (United States)

    Pinochet, Jorge; Van Sint Jan, Michael

    2016-01-01

    In a brief article published in 1931, Subrahmanyan Chandrasekhar made public an important astronomical discovery. In his article, the then young Indian astrophysicist introduced what is now known as the "Chandrasekhar limit." This limit establishes the maximum mass of a stellar remnant beyond which the repulsion force between electrons…

  3. Chandrasekhar limit: an elementary approach based on classical physics and quantum theory

    Science.gov (United States)

    Pinochet, Jorge; Van Sint Jan, Michael

    2016-05-01

    In a brief article published in 1931, Subrahmanyan Chandrasekhar made public an important astronomical discovery. In his article, the then young Indian astrophysicist introduced what is now known as the Chandrasekhar limit. This limit establishes the maximum mass of a stellar remnant beyond which the repulsion force between electrons due to the exclusion principle can no longer stop the gravitational collapse. In the present article, we create an elemental approximation to the Chandrasekhar limit, accessible to non-graduate science and engineering students. The article focuses especially on clarifying the origins of Chandrasekhar’s discovery and the underlying physical concepts. Throughout the article, only basic algebra is used as well as some general notions of classical physics and quantum theory.

  4. Sub-Chandrasekhar-mass White Dwarf Detonations Revisited

    Science.gov (United States)

    Shen, Ken J.; Kasen, Daniel; Miles, Broxton J.; Townsley, Dean M.

    2018-02-01

    The detonation of a sub-Chandrasekhar-mass white dwarf (WD) has emerged as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. Recent studies have suggested that the rapid transfer of a very small amount of helium from one WD to another is sufficient to ignite a helium shell detonation that subsequently triggers a carbon core detonation, yielding a “dynamically driven double-degenerate double-detonation” SN Ia. Because the helium shell that surrounds the core explosion is so minimal, this scenario approaches the limiting case of a bare C/O WD detonation. Motivated by discrepancies in previous literature and by a recent need for detailed nucleosynthetic data, we revisit simulations of naked C/O WD detonations in this paper. We disagree to some extent with the nucleosynthetic results of previous work on sub-Chandrasekhar-mass bare C/O WD detonations; for example, we find that a median-brightness SN Ia is produced by the detonation of a 1.0 {M}ȯ WD instead of a more massive and rarer 1.1 {M}ȯ WD. The neutron-rich nucleosynthesis in our simulations agrees broadly with some observational constraints, although tensions remain with others. There are also discrepancies related to the velocities of the outer ejecta and light curve shapes, but overall our synthetic light curves and spectra are roughly consistent with observations. We are hopeful that future multidimensional simulations will resolve these issues and further bolster the dynamically driven double-degenerate double-detonation scenario’s potential to explain most SNe Ia.

  5. ON THE PROGENITORS OF SUPER-CHANDRASEKHAR MASS TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Chen Wencong; Li Xiangdong

    2009-01-01

    Type Ia supernovae (SNe Ia) can be used as the standard candle to determine the cosmological distances because they are thought to have a uniform fuel amount. Recent observations of several overluminous SNe Ia suggest that the white dwarf masses at supernova explosion may significantly exceed the canonical Chandrasekhar mass limit. These massive white dwarfs may be supported by rapid differential rotation. Based on a single-degenerate model and the assumption that the white dwarf would differentially rotate when the accretion rate M-dot>3 x 10 -7 M-odot yr -1 , we have calculated the evolutions of close binaries consisting of a white dwarf and a normal companion. To include the effect of rotation, we introduce an effective mass M eff for white dwarfs. For the donor stars with two different metallicities Z = 0.02 and 0.001, we present the distribution of the initial donor star masses and the orbital periods of the progenitors of super-Chandrasekhar mass SNe Ia. The calculation results indicate that, for an initial massive white dwarf of 1.2 M sun , a considerable fraction of SNe Ia may result from super-Chandrasekhar mass white dwarfs, but very massive (> 1.7 M sun ) white dwarfs are difficult to form, and none of them could be found in old populations. However, super-Chandrasekhar mass SNe Ia are very rare when the initial mass of white dwarfs is 1.0 M sun . Additionally, SNe Ia in low metallicity environment are more likely to be homogeneous.

  6. J Chandrasekhar

    Indian Academy of Sciences (India)

    Resonance - Origins and Usage · J Chandrasekhar · More Details ... Molecule of the Month Maitotoxin - Holder of Two World Records · J Chandrasekhar ... Molecule of the Month Adamantane - A Plastic Piece of Diamond · J Chandrasekhar.

  7. Evidence for a Sub-Chandrasekhar-mass Type Ia Supernova in the Ursa Minor Dwarf Galaxy

    Science.gov (United States)

    McWilliam, Andrew; Piro, Anthony L.; Badenes, Carles; Bravo, Eduardo

    2018-04-01

    A long-standing problem is identifying the elusive progenitors of Type Ia supernovae (SNe Ia), which can roughly be split into Chandraksekhar and sub-Chandrasekhar-mass events. An important difference between these two cases is the nucleosynthetic yield, which is altered by the increased neutron excess in Chandrasekhar progenitors due to their pre-explosion simmering and high central density. Based on these arguments, we show that the chemical composition of the most metal-rich star in the Ursa Minor dwarf galaxy, COS 171, is dominated by nucleosynthesis from a low-metallicity, low-mass, sub-Chandrasekhar-mass SN Ia. Key diagnostic abundance ratios include Mn/Fe and Ni/Fe, which could not have been produced by a Chandrasekhar-mass SN Ia. Large deficiencies of Ni/Fe, Cu/Fe and Zn/Fe also suggest the absence of alpha-rich freeze-out nucleosynthesis, favoring low-mass white dwarf progenitors of SNe Ia, near 0.95 M ⊙, from comparisons to numerical detonation models. We also compare Mn/Fe and Ni/Fe ratios to the recent yields predicted by Shen et al., finding consistent results. To explain the [Fe/H] at ‑1.35 dex for COS 171 would require dilution of the SN Ia ejecta with ∼104 M ⊙ of material, which is expected for an SN remnant expanding into a warm interstellar medium with n ∼ 1 cm‑3. In the future, finding more stars with the unique chemical signatures we highlight here will be important for constraining the rate and environments of sub-Chandrasekhar SNe Ia.

  8. A CHANDRASEKHAR MASS PROGENITOR FOR THE TYPE Ia SUPERNOVA REMNANT 3C 397 FROM THE ENHANCED ABUNDANCES OF NICKEL AND MANGANESE

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Hiroya; Williams, Brian J.; Petre, Robert [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260 (United States); Foster, Adam R.; Brickhouse, Nancy S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bravo, Eduardo [E.T.S. Arquitectura del Vallès, Universitat Politècnica de Catalunya, Carrer Pere Serra 1-15, E-08173 Sant Cugat del Vallès (Spain); Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Nobukawa, Masayoshi; Koyama, Katsuji [Department of Physics, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Eriksen, Kristoffer A., E-mail: hiroya.yamaguchi@nasa.gov [Theoretical Design Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

    2015-03-10

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  9. A CHANDRASEKHAR MASS PROGENITOR FOR THE TYPE Ia SUPERNOVA REMNANT 3C 397 FROM THE ENHANCED ABUNDANCES OF NICKEL AND MANGANESE

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroya; Williams, Brian J.; Petre, Robert; Badenes, Carles; Foster, Adam R.; Brickhouse, Nancy S.; Bravo, Eduardo; Maeda, Keiichi; Nobukawa, Masayoshi; Koyama, Katsuji; Eriksen, Kristoffer A.

    2015-01-01

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies

  10. T Chandrasekhar

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. T Chandrasekhar. Articles written in Resonance – Journal of Science Education. Volume 7 Issue 8 August 2002 pp 29-39 General Article. The Mystery and Beauty of Total Solar Eclipses · T Chandrasekhar · More Details Fulltext PDF ...

  11. The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star.

    Science.gov (United States)

    Howell, D Andrew; Sullivan, Mark; Nugent, Peter E; Ellis, Richard S; Conley, Alexander J; Le Borgne, Damien; Carlberg, Raymond G; Guy, Julien; Balam, David; Basa, Stephane; Fouchez, Dominique; Hook, Isobel M; Hsiao, Eric Y; Neill, James D; Pain, Reynald; Perrett, Kathryn M; Pritchet, Christopher J

    2006-09-21

    The accelerating expansion of the Universe, and the need for dark energy, were inferred from observations of type Ia supernovae. There is a consensus that type Ia supernovae are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that have accreted matter from a companion star, although the nature of this companion remains uncertain. These supernovae are thought to be reliable distance indicators because they have a standard amount of fuel and a uniform trigger: they are predicted to explode when the mass of the white dwarf nears the Chandrasekhar mass of 1.4 solar masses (M(o)). Here we show that the high-redshift supernova SNLS-03D3bb has an exceptionally high luminosity and low kinetic energy that both imply a super-Chandrasekhar-mass progenitor. Super-Chandrasekhar-mass supernovae should occur preferentially in a young stellar population, so this may provide an explanation for the observed trend that overluminous type Ia supernovae occur only in 'young' environments. As this supernova does not obey the relations that allow type Ia supernovae to be calibrated as standard candles, and as no counterparts have been found at low redshift, future cosmology studies will have to consider possible contamination from such events.

  12. Information-entropic stability bound for compact objects: Application to Q-balls and the Chandrasekhar limit of polytropes

    Energy Technology Data Exchange (ETDEWEB)

    Gleiser, Marcelo, E-mail: mgleiser@dartmouth.edu; Sowinski, Damian, E-mail: Damian.Sowinski.GR@dartmouth.edu

    2013-11-25

    Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE) [1]. Investigating solitonic Q-balls and stars with a polytropic equation of state P=Kρ{sup γ}, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs (γ=4/3) with an accuracy of a few percent.

  13. The detonation of a sub-Chandrasekhar-mass white dwarf at the origin of the low-luminosity Type Ia supernova 1999by

    Science.gov (United States)

    Blondin, Stéphane; Dessart, Luc; Hillier, D. John

    2018-03-01

    While Chandrasekhar-mass (MCh) models with a low 56Ni yield can match the peak luminosities of fast-declining, 91bg-like Type Ia supernovae (SNe Ia), they systematically fail to reproduce their faster light-curve evolution. Here, we illustrate the impact of a low ejecta mass on the radiative display of low-luminosity SNe Ia, by comparing a sub-MCh model resulting from the pure central detonation of a C-O white dwarf (WD) to an MCh delayed-detonation model with the same 56Ni yield of 0.12 M⊙. Our sub-MCh model from a 0.90 M⊙ WD progenitor has a ˜5 d shorter rise time in the integrated UV-optical-IR (uvoir) luminosity, as well as in the B band, and a ˜20 per cent higher peak uvoir luminosity (˜1 mag brighter peak MB). This sub-MCh model also displays bluer maximum-light colours due to the larger specific heating rate, and larger post-maximum uvoir and B-band decline rates. The luminosity decline at nebular times is also more pronounced, reflecting the enhanced escape of gamma rays resulting from the lower density of the progenitor WD. The deficit of stable nickel in the innermost ejecta leads to a notable absence of forbidden lines of [Ni II] in the nebular spectra. In contrast, the MCh model displays a strong line due to [Ni II] 1.939 μm, which could in principle serve to distinguish between different progenitor scenarios. Our sub-MCh model offers an unprecedented agreement with optical and near-infrared observations of the 91bg-like SN 1999by, making a strong case for a WD progenitor significantly below the Chandrasekhar-mass limit for this event and other low-luminosity SNe Ia.

  14. Theoretical models of highly magnetic white dwarf stars that violate the Chandrasekhar Limit

    Science.gov (United States)

    Shah, Hridaya

    2017-08-01

    Until recently, white dwarf (WD) stars were believed to be no more massive than 1.44 solar masses (M ⊙ ). This belief has been changed now with the observations of over-luminous or 'peculiar' Type la supernovae that have lead researchers to hypothesize the existence of WDs in the mass range 2.4 - 2.8 M ⊙ . This discovery also raises some doubt over the reliability of the Type Ia supernova as a standard candle. It is thought that these super-massive WDs are their most likely progenitors and that they probably have a very strong magnetic field inside them. A degenerate electron gas in a magnetic field, such as that present inside this star, will be Landau quantized. Magnetic field changes the momentum space of electrons which in turn changes their density of states (DOS) and that in turn changes the equation of state (EoS) of matter inside the star, as opposed to that without a field. When this change in the DOS is taken into account and a link between the DOS and the EoS is established, as is done in this work, I find a physical reason behind the theoretical mass-radius (M-R) relations of a super-massive WD. I start with different equations of state with at most three Landau levels occupied and then construct stellar models of magnetic WDs (MWDs) using the same. I also show the M-R relations of these stars for a particular chosen value of maximum electron Fermi energy. Once a multiple Landau level system of electrons is considered, I find that it leads to such an EoS that gives multiple branches in the MR relations. Super-massive MWDs are obtained only when the Landau level occupancy is limited to just one level and some of the mass values fall within the mass range given above.

  15. An Accreting White Dwarf near the Chandrasekhar Limit in the Andromeda Galaxy

    Science.gov (United States)

    Tang, Sumin; Bildsten, Lars; Wolf, William M.; Li, K. L.; Kong, Albert K. H.; Cao, Yi; Cenko, S. Bradley; De Cia, Annalisa; Kasliwal, Mansi M.; Kulkarni, Shrinivas R.; hide

    2014-01-01

    The iPTF (Intermediate Palomar Transient Factory) detection of the most recent outburst of the recurrent nova system RX J0045.4+4154 in the Andromeda Galaxy has enabled the unprecedented study of a massive (mass is greater than 1.3 solar masses) accreting white dwarf (WD). We detected this nova as part of the near daily iPTF monitoring of M31 to a depth of R (red band-pass filter) approximately equal to magnitude 21 and triggered optical photometry, spectroscopy and soft X-ray monitoring of the outburst. Peaking at an absolute magnitude of MR (red, mid-infrared band-pass filter) equals magnitude -6.6, and with a decay time of 1 magnitude per day, it is a faint and very fast nova. It shows optical emission lines of He/N and expansion velocities of 1900 to 2600 kilometers per second 1-4 days after the optical peak. The Swift monitoring of the X-ray evolution revealed a supersoft source (SSS) with kT (energy: Boltzmann constant times temperature) (sub eff (effective)) approximately equal to 90-110 electronvolts that appeared within 5 days after the optical peak, and lasted only 12 days. Most remarkably, this is not the first event from this system, rather it is a recurrent nova with a time between outbursts of approximately 1 year, the shortest known. Recurrent X-ray emission from this binary was detected by ROSAT in 1992 and 1993, and the source was well characterized as a mass greater than 1.3 solar masses WD SSS. Based on the observed recurrence time between different outbursts, the duration and effective temperature of the SS phase, MESA models of accreting WDs allow us to constrain the accretion rate to mass greater than 1.7x10 (sup -7) solar masses per year and WD mass greater than 1.30 solar masses. If the WD keeps 30 percent of the accreted material, it will take less than a million years to reach core densities high enough for carbon ignition (if made of C/O) or electron capture (if made of O/Ne) to end the binary evolution.

  16. An accreting white dwarf near the Chandrasekhar limit in the Andromeda galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Sumin; Bildsten, Lars [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Wolf, William M. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Li, K. L.; Kong, Albert K. H. [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Cao, Yi; Kulkarni, Shrinivas R.; Perley, Daniel A.; Prince, Thomas A. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); De Cia, Annalisa [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Kasliwal, Mansi M. [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Laher, Russ R.; Surace, Jason [Spitzer Science Center, California Institute of Technology, M/S 314-6, Pasadena, CA 91125 (United States); Masci, Frank [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2014-05-01

    The intermediate Palomar Transient Factory (iPTF) detection of the most recent outburst of the recurrent nova (RN) system RX J0045.4+4154 in the Andromeda galaxy has enabled the unprecedented study of a massive (M > 1.3 M {sub ☉}) accreting white dwarf (WD). We detected this nova as part of the near-daily iPTF monitoring of M31 to a depth of R ≈ 21 mag and triggered optical photometry, spectroscopy and soft X-ray monitoring of the outburst. Peaking at an absolute magnitude of M{sub R} = –6.6 mag, and with a decay time of 1 mag per day, it is a faint and very fast nova. It shows optical emission lines of He/N and expansion velocities of 1900-2600 km s{sup –1} 1-4 days after the optical peak. The Swift monitoring of the X-ray evolution revealed a supersoft source (SSS) with kT {sub eff} ≈ 90-110 eV that appeared within 5 days after the optical peak, and lasted only 12 days. Most remarkably, this is not the first event from this system, rather it is an RN with a time between outbursts of approximately 1 yr, the shortest known. Recurrent X-ray emission from this binary was detected by ROSAT in 1992 and 1993, and the source was well characterized as a M > 1.3 M {sub ☉} WD SSS. Based on the observed recurrence time between different outbursts, the duration and effective temperature of the SS phase, MESA models of accreting WDs allow us to constrain the accretion rate to M-dot >1.7×10{sup −7} M{sub ⊙} yr{sup −1} and WD mass >1.30 M {sub ☉}. If the WD keeps 30% of the accreted material, it will take less than a Myr to reach core densities high enough for carbon ignition (if made of C/O) or electron capture (if made of O/Ne) to end the binary evolution.

  17. Hydrodynamic Simulations of Classical Nova explosions: predictions of 7Be and 7Li production and the growth to the Chandrasekhar Limit

    Science.gov (United States)

    Starrfield, Sumner; Bose, Maitrayee; Iliadis, Christian; Hix, William R.; Wagner, R. Mark; Woodward, Charles E.; Jose', Jordi; Hernanz, Margarita

    2018-01-01

    We have continued our studies of Classical Nova explosions by following the evolution of thermonuclear runaways (TNRs) on Carbon Oxygen white dwarfs (WDs). We have varied both the mass of the WD and the composition of the accreted material. We now rely on the results of multi-D studies of TNRs in WDs that accrete only Solar matter. They find that mixing with the core occurs after the TNR is well underway, reaching enrichment levels in agreement with observations of the ejecta abundances. We, therefore, accrete only Solar matter with NOVA (our 1-D, fully implicit, hydro code) until the TNR is initiated and then switch the accreted composition to a mixed composition: either 25% core and 75% Solar or 50% core and 50% Solar. Because the amount of accreted material is inversely proportional to the initial 12C abundance, by accreting Solar matter the amount of material taking part in the outburst is larger than if we had used mixed material from the beginning. We follow the TNR through the peak and tabulate the amount of ejected gases, their velocities and abundances. We also predict the amount of 7Li and 7Be produced and ejected by the explosion and compare our predictions to the observations in a companion poster describing the LBT measurements of 7Li in V5668 Sgr. We also compare our abundance predictions to those measured in pre-solar grains that may arise from Classical Nova explosions. Our predictions are also compared to results with SHIVA (Josè and Hernanz). Finally, many of these simulations eject significantly less mass than accreted and, therefore, the WD is growing in mass toward the Chandrasekhar Limit. This suggests that the single degenerate scenario is still a viable option for SN Ia progenitors. This work was supported in part by NASA under the Astrophysics Theory Program grant 14-ATP14-0007 and the U.S. DOE under Contract No. DE-FG02- 97ER41041. SS acknowledges partial support from NASA and HST grants to ASU and WRH is supported by the U.S. Department

  18. On the type Ia supernovae 2007on and 2011iv: evidence for Chandrasekhar-mass explosions at the faint end of the luminosity-width relationship

    Science.gov (United States)

    Ashall, C.; Mazzali, P. A.; Stritzinger, M. D.; Hoeflich, P.; Burns, C. R.; Gall, C.; Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Foley, Ryan J.

    2018-06-01

    Radiative transfer models of two transitional type Ia supernovae (SNe Ia) have been produced using the abundance stratification technique. These two objects - designated SN 2007on and SN 2011iv - both exploded in the same galaxy, NGC 1404, which allows for a direct comparison. SN 2007on synthesized 0.25 M_{⊙} of 56Ni and was less luminous than SN 2011iv, which produced 0.31 M_{⊙} of 56Ni. SN 2007on had a lower central density (ρc) and higher explosion energy (Ekin ˜1.3 ± 0.3 × 1051erg) than SN 2011iv, and it produced less nuclear statistical equilibrium (NSE) elements (0.06 M_{⊙}). Whereas, SN 2011iv had a larger ρc, which increased the electron capture rate in the lowest velocity regions, and produced 0.35 M_{⊙} of stable NSE elements. SN 2011iv had an explosion energy of ˜Ekin ˜0.9 ± 0.2 × 1051erg. Both objects had an ejecta mass consistent with the Chandrasekhar mass (Ch-mass), and their observational properties are well described by predictions from delayed-detonation explosion models. Within this framework, comparison to the sub-luminous SN 1986G indicates SN 2011iv and SN 1986G have different transition densities (ρtr) but similar ρc. Whereas SN 1986G and SN 2007on had a similar ρtr but different ρc. Finally, we examine the colour-stretch parameter sBV versus Lmax relation and determine that the bulk of SNe Ia (including the sub-luminous ones) are consistent with Ch-mass delayed-detonation explosions, where the main parameter driving the diversity is ρtr. We also find ρc to be driving the second-order scatter observed at the faint end of the luminosity-width relationship.

  19. Accretion onto Carbon-Oxygen White Dwarfs as a possible mechanism for growth to the Chandrasekhar Limit

    Science.gov (United States)

    Starrfield, Sumner; Bose, Maitrayee; Iliadis, Christian; Hix, William R.; José, Jordi; Hernanz, Margarita

    2017-08-01

    We have continued our studies of accretion onto white dwarfs by following the evolution of thermonuclear runaways (TNRs) on Carbon Oxygen (CO) white dwarfs. We have varied the mass of the white dwarf and the composition of the accreted material. We use the results of the multi-dimensional studies of TNRs in white dwarfs, accreting only Solar matter, which show that sufficient core material is dredged-up by the TNR and then ejected by the explosion to agree with the observations of the ejecta abundances. We have also found that the initial 12C abundance is inversely proportional to the amount of material accreted prior to the TNR. Therefore, we first accrete Solar material and follow the evolution until a TNR occurs. Because the 12C abundance is significantly smaller then if we had initially mixed the accreting gas with the carbon-oxygen core, more matter takes part in the explosion than if we had begun the evolution with the mixed composition. We then instantaneously switch the composition to a mixture with either 25% core material or 50% core material (plus accreted material) and follow the resulting evolution of the TNR. We use our 1D, Lagrangian, hydrodynamic code: NOVA. We report on the results of these new simulations and compare the ejecta abundances to those measured in pre-solar grains that are thought to arise from classical nova explosions. These results will also be compared to recent results with SHIVA (Josè and Hernanz). We find that there are some white dwarf masses where significantly less mass is ejected than accreted during the Classical Nova event and, therefore, the white dwarf is growing in mass as a result of the accretion and in spite of the resulting explosion.This work was supported in part by NASA under the Astrophysics Theory Program grant 14-ATP14-0007 and the U.S. DOE under Contract No. DE-FG02- 97ER41041. SS acknowledges partial support from NASA, NSF, and HST grants to ASU and WRH is supported by the U.S. Department of Energy, Office

  20. Integration of Chandrasekhar's integral equation

    International Nuclear Information System (INIS)

    Tanaka, Tasuku

    2003-01-01

    We solve Chandrasekhar's integration equation for radiative transfer in the plane-parallel atmosphere by iterative integration. The primary thrust in radiative transfer has been to solve the forward problem, i.e., to evaluate the radiance, given the optical thickness and the scattering phase function. In the area of satellite remote sensing, our problem is the inverse problem: to retrieve the surface reflectance and the optical thickness of the atmosphere from the radiance measured by satellites. In order to retrieve the optical thickness and the surface reflectance from the radiance at the top-of-the atmosphere (TOA), we should express the radiance at TOA 'explicitly' in the optical thickness and the surface reflectance. Chandrasekhar formalized radiative transfer in the plane-parallel atmosphere in a simultaneous integral equation, and he obtained the second approximation. Since then no higher approximation has been reported. In this paper, we obtain the third approximation of the scattering function. We integrate functions derived from the second approximation in the integral interval from 1 to ∞ of the inverse of the cos of zenith angles. We can obtain the indefinite integral rather easily in the form of a series expansion. However, the integrals at the upper limit, ∞, are not yet known to us. We can assess the converged values of those series expansions at ∞ through calculus. For integration, we choose coupling pairs to avoid unnecessary terms in the outcome of integral and discover that the simultaneous integral equation can be deduced to the mere integral equation. Through algebraic calculation, we obtain the third approximation as a polynomial of the third degree in the atmospheric optical thickness

  1. Limits on the photon mass

    International Nuclear Information System (INIS)

    Vasseur, G.

    1996-03-01

    Is the photon mass strictly null as it is told in quantum electrodynamics. In fact, a coherent theory can be build with a massive photon. Experiences have been regularly led to try to make obvious an eventual non null photon mass. Superior limits more and more strict have been found. Here is given a general survey of the consequences of a non null photon mass, different methods to measure it and the achieved limits. (author). 30 refs., 1 fig

  2. The mass limit of white dwarfs with strong magnetic fields in general relativity

    International Nuclear Information System (INIS)

    Wen De-Hua; Liu He-Lei; Zhang Xiang-Dong

    2014-01-01

    Recently, U. Das and B. Mukhopadhyay proposed that the Chandrasekhar limit of a white dwarf could reach a new high level (2.58M⊙) if a superstrong magnetic field were considered (Das U and Mukhopadhyay B 2013 Phys. Rev. Lett. 110 071102), where the structure of the strongly magnetized white dwarf (SMWD) is calculated in the framework of Newtonian theory (NT). As the SMWD has a far smaller size, in contrast with the usual expectation, we found that there is an obvious general relativistic effect (GRE) in the SMWD. For example, for the SMWD with a one Landau level system, the super-Chandrasekhar mass limit in general relativity (GR) is approximately 16.5% lower than that in NT. More interestingly, the maximal mass of the white dwarf will be first increased when the magnetic field strength keeps on increasing and reaches the maximal value M = 2.48M⊙ with B D = 391.5. Then if we further increase the magnetic fields, surprisingly, the maximal mass of the white dwarf will decrease when one takes the GRE into account. (geophysics, astronomy, and astrophysics)

  3. The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428.

    Science.gov (United States)

    Santander-García, M; Rodríguez-Gil, P; Corradi, R L M; Jones, D; Miszalski, B; Boffin, H M J; Rubio-Díez, M M; Kotze, M M

    2015-03-05

    The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (M(⊙)). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche lobe as the star expands during the asymptotic giant branch phase. The excess gas eventually forms a common envelope surrounding both stars. Drag forces then result in the envelope being ejected into a bipolar planetary nebula whose equator is coincident with the orbital plane of the system. Systems in which both stars have ejected their envelopes and are evolving towards the white dwarf stage are said to be double degenerate. Here we report that Henize 2-428 has a double-degenerate core with a combined mass of ∼1.76M(⊙), which is above the Chandrasekhar limit (the maximum mass of a stable white dwarf) of 1.4M(⊙). This, together with its short orbital period (4.2 hours), suggests that the system should merge in 700 million years, triggering a type Ia supernova event. This supports the hypothesis of the double-degenerate, super-Chandrasekhar evolutionary pathway for the formation of type Ia supernovae.

  4. Photon and graviton mass limits

    International Nuclear Information System (INIS)

    Goldhaber, Alfred Scharff; Nieto, Michael Martin

    2010-01-01

    Efforts to place limits on deviations from canonical formulations of electromagnetism and gravity have probed length scales increasing dramatically over time. Historically, these studies have passed through three stages: (1) testing the power in the inverse-square laws of Newton and Coulomb, (2) seeking a nonzero value for the rest mass of photon or graviton, and (3) considering more degrees of freedom, allowing mass while preserving explicit gauge or general-coordinate invariance. Since the previous review the lower limit on the photon Compton wavelength has improved by four orders of magnitude, to about one astronomical unit, and rapid current progress in astronomy makes further advance likely. For gravity there have been vigorous debates about even the concept of graviton rest mass. Meanwhile there are striking observations of astronomical motions that do not fit Einstein gravity with visible sources. ''Cold dark matter'' (slow, invisible classical particles) fits well at large scales. ''Modified Newtonian dynamics'' provides the best phenomenology at galactic scales. Satisfying this phenomenology is a requirement if dark matter, perhaps as invisible classical fields, could be correct here too. ''Dark energy''might be explained by a graviton-mass-like effect, with associated Compton wavelength comparable to the radius of the visible universe. Significant mass limits are summarized in a table.

  5. Photon and graviton mass limits

    Science.gov (United States)

    Goldhaber, Alfred Scharff; Nieto, Michael Martin

    2010-01-01

    Efforts to place limits on deviations from canonical formulations of electromagnetism and gravity have probed length scales increasing dramatically over time. Historically, these studies have passed through three stages: (1) testing the power in the inverse-square laws of Newton and Coulomb, (2) seeking a nonzero value for the rest mass of photon or graviton, and (3) considering more degrees of freedom, allowing mass while preserving explicit gauge or general-coordinate invariance. Since the previous review the lower limit on the photon Compton wavelength has improved by four orders of magnitude, to about one astronomical unit, and rapid current progress in astronomy makes further advance likely. For gravity there have been vigorous debates about even the concept of graviton rest mass. Meanwhile there are striking observations of astronomical motions that do not fit Einstein gravity with visible sources. “Cold dark matter” (slow, invisible classical particles) fits well at large scales. “Modified Newtonian dynamics” provides the best phenomenology at galactic scales. Satisfying this phenomenology is a requirement if dark matter, perhaps as invisible classical fields, could be correct here too. “Dark energy” might be explained by a graviton-mass-like effect, with associated Compton wavelength comparable to the radius of the visible universe. Significant mass limits are summarized in a table.

  6. Photon and graviton mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

    2008-01-01

    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  7. S Chandrasekhar the man behind the legend

    CERN Document Server

    1997-01-01

    Subrahmanyan Chandrasekhar - known simply as Chandra throughout the scientific world - has become a legendary figure for his prolific contributions to physics, astrophysics, and applied mathematics. Before his death in 1995, Chandra had forbidden a memorial of the conventional sort, celebrating his life. This book, which contains some thirty articles by his former students, his associates, and his colleagues, is in a sense a memorial volume. It says little about Chandra's great scientific achievements, but shows his human side and the various facets of his brilliant personality, his incredible

  8. Supernova constraints on neutrino mass and mixing

    Indian Academy of Sciences (India)

    the Chandrasekhar limiting mass the pressure of the relativistic electron gas alone can ... and facilitates electron capture by nuclei and free protons leading to .... the neutrino luminosity in units of 10 ¾ ergs/sec, Т and Ф are the neutron and proton ... would be changed to М . One can make a rough estimate of the increase in ...

  9. Limits on the electron-antineutrino mass

    International Nuclear Information System (INIS)

    Wilkerson, J.F.

    1987-01-01

    New measurements near the endpoint of the tritium beta-decay spectrum are producing limits on the electron-antineutrino mass which are below the central mass value of 30 eV reported by ITEP. The factors that influence the neutrino mass sensitivity of tritium beta decay measurements will be discussed followed by a review of the current experimental results. 9 refs., 5 figs., 2 tabs

  10. Mass limit for the lightest neutralino

    CERN Document Server

    Buskulic, D.; Decamp, D.; Ghez, Philippe; Goy, C.; Lees, J.P.; Lucotte, A.; Minard, M.N.; Nief, J.Y.; Odier, P.; Pietrzyk, B.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I.C.; Pascual, A.; Perlas, J.A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A.O.; Bright-Thomas, P.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R.W.; Frank, M.; Hagelberg, R.; Harvey, John; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E.B.; Mato, P.; Minten, A.; Miquel, R.; Mir, L.M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.F.; Ranjard, F.; Rensing, P.; Rolandi, Gigi; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I.R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.M.; Fearnley, T.; Hansen, J.B.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Rensch, B.; Waananen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.C.; Rouge, A.; Rumpf, M.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D.E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S.J.; Halley, A.W.; Knowles, I.G.; Lynch, J.G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J.M.; Smith, K.; Teixeira-Dias, P.; Thompson, A.S.; Thomson, F.; Thorn, S.; Turnbull, R.M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Morawitz, P.; Moutoussi, A.; Nash, J.; Sedgbeer, J.K.; Stacey, A.M.; Williams, M.D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A.P.; Bowdery, C.K.; Colrain, P.; Crawford, G.; Finch, A.J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E.P.; Williams, M.I.; Galla, A.; Greene, A.M.; Hoffmann, C.; Jacobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J.J.; Bencheikh, A.M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Bauer, C.; Berlich, R.; Blum, W.; Buescher, Volker; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lutjens, G.; Lutz, G.; Manner, W.; Moser, H.G.; Richter, Robert; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, Richard Dante; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Hocker, Andreas; Jacholkowska, A.; Jacquet, M.; Kim, D.W.; Le Diberder, F.; Lefrancois, J.; Lutz, A.M.; Nikolic, Irina; Park, H.J.; Schune, M.H.; Simion, S.; Veillet, J.J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, Giuseppe; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M.A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P.S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciaba, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P.G.; Walsh, J.; Blair, G.A.; Bryant, L.M.; Cerutti, F.; Chambers, J.T.; Gao, Y.; Green, M.G.; Medcalf, T.; Perrodo, P.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Botterill, D.R.; Clifft, R.W.; Edgecock, T.R.; Haywood, S.; Maley, P.; Norton, P.R.; Thompson, J.C.; Wright, A.E.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Boswell, R.; Brew, C.A.J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W.M.; Reeve, J.; Thompson, L.F.; Boehrer, Armin; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, N.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Elmer, P.; Feng, Z.; Ferguson, D.P.S.; Gao, Y.S.; Gonzales, S.; Grahl, J.; Greening, T.C.; Hayes, O.J.; Hu, H.; McNamara, P.A., III; Nachtman, J.M.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, A.M.; Wu, Sau Lan; Wu, X.; Yamartino, J.M.; Zheng, M.; Zobernig, G.

    1996-01-01

    Indirect limits on the mass of the lightest neutralino are derived from the results of searches for charginos, neutralinos, and sleptons performed with data taken by the ALEPH Collaboration at centre-of-mass energies near the Z peak and at 130 and 136 GeV. Within the context of the Minimal Supersymmetric Standard Model and when $M_{\\tilde\

  11. A theoretical limit on the Higgs mass

    International Nuclear Information System (INIS)

    Temiraliev, A.T.

    2007-01-01

    Full text: The standard model of particle physics, which describes masses through the Higgs mechanism, contains parameters - such as particle masses - whose origins are still unknown and which cannot be exactly predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark and W boson constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. Several more or less precise arguments can set the upper limit for a standard model Higgs particle. All of them follows the line that the standard model breaks down of the Higgs mass is pushed too far upwards. The theoretical bounds will be reviewed. With gauge-top quark Yukawa coupling unification the standard model Higgs boson mass is estimated to be about 135 GeV. In the article will be consider an approximation of 4-fermion interactions. And as a result, the most likely Higgs mass is 150 GeV. The upper limit on the Higgs mass at the 90 % confidence level is about 250 GeV

  12. About limit masses of elementary particles

    International Nuclear Information System (INIS)

    Ibadova, U.R.

    2002-01-01

    when the mass of particles can be compared with the mass of automobiles. The modern QFT does not forbid such physically meaningless extrapolation. Perhaps, it is a principal defect of the theory? In 1965 Markov put forward a hypothesis, according to which the spectrum of masses of elementary particles must jump into discontinuity on the Planck's mass m plank = √hℎc/G , well-known universal constants ℎ, c and G-gravitational constant take place in this expression. Markov named particles of a limiting mass as 'maximons'. The concept of 'maximon' is placed in a basis of the Markov plot of the early Universe. It is necessary to mention that the standard theoretical-field apparatus is used for the description of the 'maximon'. The Markov's idea concerning the existence of finite limit for value of the mass of elementary particles as fundamental physical principle, that is similar to the relativistic and quantum postulates in basis of QFT was realized by V.G.Kadyshevsky. Here the Markov's condition is noted as m< M, considering a limiting mass M simply as new universal constant in the theory of 'fundamental mass'. In the given work, we have strived for the connection of the universal constants (ℎ, c, G), 'Planck's mass' 'maximon' and 'fundamental mass' on basis of the spontaneous breaking of symmetry

  13. Limit on the tau neutrino mass

    International Nuclear Information System (INIS)

    Cinabro, D.; Henderson, S.; Kinoshita, K.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Sadoff, A.J.; Ammar, R.; Ball, S.; Baringer, P.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Patton, S.; Perticone, D.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; O'Neill, J.J.; Romero, V.; Severini, H.; Sun, C.R.; Zoeller, M.M.; Crawford, G.; Fulton, R.; Fujino, D.; Gan, K.K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Skovpen, Y.; Sung, M.; White, C.; Whitmore, J.; Wilson, P.; Butler, F.; Fu, X.; Kalbfleisch, G.; Lambrecht, M.; Ross, W.R.; Skubic, P.; Snow, J.; Wang, P.L.; Wood, M.; Bortoletto, D.; Brown, D.N.; Dominick, J.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Schaffner, S.F.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Kroha, H.; Roberts, S.; Sparks, K.; Thorndike, E.H.; Wang, C.H.; Sanghera, S.; Skwarnicki, T.; Stroynowski, R.; Artuso, M.; He, D.; Goldberg, M.; Horwitz, N.; Kennett, R.; Moneti, G.C.; Muheim, F.; Mukhin, Y.; Playfer, S.; Rozen, Y.; Rubin, P.; Stone, S.; Thulasidas, M.; Vasseur, G.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Egyed, Z.; Jain, V.; Sheldon, P.; Akerib, D.S.; Barish, B.; Chadha, M.; Chan, S.; Cowen, D.F.; Eigen, G.; Miller, J.S.; Urheim, J.; Weinstein, A.J.; Acosta, D.; Athanas, M.; Masek, G.; Ong, B.; Paar, H.; Sivertz, M.; Bean, A.; Gronberg, J.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Richman, J.D.; Tajima, H.; Schmidt, D.; Sperka, D.; Witherell, M.S.; Procario, M.; Yang, S.; Balest, R.; Cho, K.; Daoudi, M.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Besson, D.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Drell, P.S.; Ehrlich, R.; Galik, R.S.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.

    1993-01-01

    A limit on the tau neutrino mass M ντ is obtained from a study of tau decays in the reaction e + e-→τ + τ - at center-of-mass energies ∼10.6 GeV. The result is based on an end-point analysis of the invariant mass spectrum of the decay products in the decay modes τ - →3h - 2h + ν τ and τ - →2h - h+2π 0 ν τ . The data sample used in this analysis contains 1.77x10 6 tau pairs, corresponding to an integrated luminosity of 1.92 fb -1 , and is substantially larger than previous data samples used to place a limit on M ντ . The limit obtained for both five-hadron modes together is 32.6 MeV at 95% C.L

  14. Mass limits for the muon neutrino

    International Nuclear Information System (INIS)

    Hoffman, C.M.; Sandberg, V.D.

    1982-01-01

    The possibility of improving the present limit on the mass of the muon neutrino is discussed. It is found that decays of muons and pions are not useful means to significantly improve this limit. On the other hand, the decays K 0 /sub L/ → π/sup +-/μ/sup -+/nu/sub μ/ and K + → π 0 μ + nu/sub μ/ appear to be quite promising. Possible experiments are discussed

  15. Mass limit for the lightest neutralino

    Science.gov (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Nief, J.-Y.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Quyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bright-Thomas, P.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J. C.; Rougé, A.; Rumpf, M.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Morawitz, P.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Hoffmann, C.; Jacobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Bauer, C.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacholkowska, A.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignain, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emerya, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Williams, R. W.; Armstrong, S. R.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.

    1996-12-01

    Indirect limits on the mass of the lightest neutralino are derived from the results of searches for charginos, neutralinos, and sleptons performed with data taken by the ALEPH Collaboration at centre-of-mass energies near the Z peak and at 130 and 136 GeV. Within the context of the Minimal Supersymmetric Standard Model and whenM_{tilde ν } ≥slant 200 GeV/c^2 , the bound M x > 12.8 GeV/ c 2 at the 95% confidence level applies for any tan β. The impact of lighter sneutrinos is presented in the framework of SUSY grand unified theories; a massless neutralino is allowed only for a narrow range of tan β, μ, and the scalar mass parameter m 0. Finally, by including Higgs mass constraints and requiring that radiative electroweak symmetry breaking occur, more stringent bounds on M x as a function of tan β are derived.

  16. Axion mass limits from pulsar x rays

    International Nuclear Information System (INIS)

    Morris, D.E.

    1984-12-01

    Axions thermally emitted by a neutron star would be converted into x rays in the strong magnetic field surrounding the star. An improvement in the observational upper limit of pulsed x rays from the Vela pulsar (PSR 0833-45) by a factor of 12 would constrain the axion mass M/sub a/ -3 eV if the core is non-superfluid and at temperature T/sub c/ greater than or equal to 2 x 10 8 K. If the core is superfluid throughout, an improvement factor of 240 would be needed to provide the same constraint on the axion mass, while in the absence of superfluidity, an improvement factor of 200 could constrain M/sub a/ -4 eV. A search for modulated hard x rays from PSR 1509-58 or other young pulsars at presently attainable sensitivities may enable the setting of an upper limit for the axion mass. Observation of hard x rays from a very young hot pulsar with T/sub c/ greater than or equal to 7 x 10 8 K could set a firm bound on the axion mass, since neutron superfluidity is not expected above this temperature. The remaining axion mass range 6 x 10 -4 eV > M/sub a/ > 10 -5 eV (the cosmological lower bound) can be covered by an improved Sikivie type laboratory cavity detector for relic axions constituting the galactic halo. 48 refs

  17. Pulsation, Mass Loss and the Upper Mass Limit

    Science.gov (United States)

    Klapp, J.; Corona-Galindo, M. G.

    1990-11-01

    RESUMEN. La existencia de estrellas con masas en exceso de 100 M0 ha sido cuestionada por mucho tiempo. Lfmites superiores para la masa de 100 M0 han sido obtenidos de teorfas de pulsaci6n y formaci6n estelar. En este trabajo nosotros primero investigamos la estabilidad radial de estrellas masivas utilizando la aproximaci6n clasica cuasiadiabatica de Ledoux, la aproximaci6n cuasiadiabatica de Castor y un calculo completamente no-adiabatico. Hemos encontrado que los tres metodos de calculo dan resultados similares siempre y cuando una pequefia regi6n de las capas externas de la estrella sea despreciada para la aproximaci6n clasica. La masa crftica para estabilidad de estrellas masivas ha sido encontrada en acuerdo a trabajos anteriores. Explicamos Ia discrepancia entre este y trabajos anteriores por uno de los autores. Discunmos calculos no-lineales y perdida de masa con respecto a) lfmite superior de masa. The existence of stars with masses in excess of 100 M0 has been questioned for a very long time. Upper mass limits of 100 Me have been obtained from pulsation and star formation theories. In this work we first investigate the radial stability of massive stars using the classical Ledoux's quasiadiabatic approximation. the Castor quasiadiabatic approximation and a fully nonadiabatic calculation. We have found that the three methods of calculation give similar results provided that a small region in outer layers of the star be neglected for the classical approximation. The critical mass for stability of massive stars is found to be in agreement with previous work. We explain the reason for the discrepancy between this and previous work by one of the authors. We discuss non-linear calculations and mass loss with regard to the upper mass limit. Key words: STARS-MASS FUNCTION - STARS-MASS LOSS - STARS-PULSATION

  18. Mass limits on neutralino dark matter

    International Nuclear Information System (INIS)

    Gilmore, Rudy C.

    2007-01-01

    We set an upper limit on the mass of a supersymmetric neutralino dark matter particle using the MicrOMEGAS and DarkSUSY software packages and the most recent constraints on relic density from combined Wilkinson Microwave Anisotropy Probe and Sloan Digital Sky Survey data. We explore several different possible scenarios within the minimal supersymmetric standard model, including coannihilation with charginos and sfermions and annihilation through a massive Higgs resonance, using low-energy mass inputs. We find that no coannihilation scenario is consistent with dark matter in observed abundance with a mass greater than 2.5 TeV for a W-ino-type particle or 1.8 TeV for a Higgsino-type. Contrived scenarios involving Higgs resonances with finely tuned mass parameters can allow masses as high as 34 TeV. The resulting gamma-ray energy distribution is not in agreement with the recent multi-TeV gamma-ray spectrum observed by H. E. S. S. originating from the center of the Milky Way. Our results are relevant only for dark matter densities resulting from a thermal origin

  19. Mrs. Chandrasekhar addresses the media in TRW Media Hospitality Tent

    Science.gov (United States)

    1999-01-01

    Mrs. Lalitha Chandrasekhar (right), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC as Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C., looks on. The name 'Chandra,' a shortened version of her husband's name which he preferred among friends and colleagues, was chosen in a contest to rename the Advanced X-ray Astrophysics Facility. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.

  20. Photon Mass Limits from Fast Radio Bursts

    CERN Document Server

    Bonetti, Luca; Mavromatos, Nikolaos E.; Sakharov, Alexander S.; Sarkisyan-Grinbaum, Edward K.G.; Spallicci, Alessandro D.A.M.

    2016-06-10

    The frequency-dependent time delays in fast radio bursts (FRBs) can be used to constrain the photon mass, if the FRB redshifts are known, but the similarity between the frequency dependences of dispersion due to plasma effects and a photon mass complicates the derivation of a limit on $m_\\gamma$. The redshift of FRB 150418 has been measured to $\\sim 2$% and its dispersion measure (DM) is known to $\\sim 0.1$%, but the strength of the constraint on $m_\\gamma$ is limited by uncertainties in the modelling of the host galaxy and the Milky Way, as well as possible inhomogeneities in the intergalactic medium (IGM). Allowing for these uncertainties, the recent data on FRB 150418 indicate that $m_\\gamma \\lesssim 1.7 \\times 10^{-14}$ eV c$^{-2}$ ($4.6 \\times 10^{-50}$ kg). In the future, the different redshift dependences of the plasma and photon mass contributions to DM can be used to improve the sensitivity to $m_\\gamma$ if more FRB redshifts are measured. For a fixed fractional uncertainty in the extra-galactic cont...

  1. The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-masswhite dwarf star

    Energy Technology Data Exchange (ETDEWEB)

    Howell, D.Andrew; Sullivan, Mark; Nugent, Peter E.; Ellis,Richard S.; Conley, Alexander J.; Le Borgne, Damien; Carlberg, RaymondG.; Guy, Julien; Balam, David; Basa, Stephane; Fouchez, Dominique; Hook,Isobel M.; Hsiao, Eric Y.; Neill, James D.; Pain, Reynald; Perrett,Kathryn M.; Pritchet, Christopher J.

    2006-02-01

    The acceleration of the expansion of the universe, and theneed for Dark Energy, were inferred from the observations of Type Iasupernovae (SNe Ia) 1;2. There is consensus that SNeIa are thermonuclearexplosions that destroy carbon-oxygen white dwarf stars that accretematter from a companion star3, although the nature of this companionremains uncertain. SNe Ia are thought to be reliable distance indicatorsbecause they have a standard amount of fuel and a uniform trigger theyare predicted to explode when the mass of the white dwarf nears theChandrasekhar mass 4 - 1.4 solar masses. Here we show that the highredshift supernova SNLS-03D3bb has an exceptionally high luminosity andlow kinetic energy that both imply a super-Chandrasekhar mass progenitor.Super-Chandrasekhar mass SNeIa shouldpreferentially occur in a youngstellar population, so this may provide an explanation for the observedtrend that overluminous SNe Ia only occur in young environments5;6. Sincethis supernova does not obey the relations that allow them to becalibrated as standard candles, and since no counterparts have been foundat low redshift, future cosmology studies will have to considercontamination from such events.

  2. Beyond the Chandrasekhar limit: Structure and formation of compact ...

    Indian Academy of Sciences (India)

    sparked the thought that the ultimate fate of more massive stars might be ... pressure of quarks balances the configuration against the combined action ... At the centres of stars massive enough to undergo all stages of nuclear fusion, inert iron.

  3. Resolution of the mystery behind Chandrasekhar's black hole transformations

    Energy Technology Data Exchange (ETDEWEB)

    Heading, J [University Coll. of Wales, Aberystwyth (UK)

    1977-06-01

    Investigating three differential equations in normal form governing the perturbations of the Schwarzschild black hole, Chandrasekhar (Chandrasekhar, S., Proc. Royal Soc. A.; 343, 289-298 (1975)) has demonstrated the somewhat complicated transformations between these equations. This complication hides the basic nature of the transformations and their mutual connections. The whole scheme can be parametrized, with one condition imposed, yielding for every functional parameter inevitably three potentials of the above types. Any Schroedinger equation in normal form can be similarly treated, but the analogous Bardeen and Press potential is more complicated than the original. Thus an investigation is undertaken as to why the Bardeen and Press potential for the black hole is analytically 'simple'; conditions for this simplicity inevitably lead to this particular potential, and hence to the other two potentials. Every symbol occurring in these three potentials is thereby explained analytically.

  4. Limit on mass differences in the Weinberg model

    NARCIS (Netherlands)

    Veltman, M.J.G.

    1977-01-01

    Within the Weinberg model mass differences between members of a multiplet generate further mass differences between the neutral and charged vector bosons. The experimental situation on the Weinberg model leads to an upper limit of about 800 GeV on mass differences within a multiplet. No limit on the

  5. Improved Limits on Spin-Mass Interactions

    Science.gov (United States)

    Lee, Junyi; Almasi, Attaallah; Romalis, Michael

    2018-04-01

    Very light particles with C P -violating couplings to ordinary matter, such as axions or axionlike particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces between unpolarized nucleons in two 250 kg Pb weights and polarized neutrons and electrons in a 3He -K comagnetometer located about 15 cm away. We place improved constraints on the products of scalar and pseudoscalar coupling constants, gpngsNneutron laboratory limit.

  6. A biased review of tau neutrino mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Duboscq, J.E

    2001-04-01

    After a quick review of astrophysically relevant limits, I present a summary of MeV scale tau neutrino mass limits derived from accelerator based experiments. I argue that the current published limits appear to be too consistent, and that we therefore cannot conclude that the tau neutrino mass limit is as low as usually claimed. I provide motivational arguments calling into question the assumed statistical properties of the usual maximum likelihood estimators, and provide a prescription for deriving a more robust and understandable mass limit.

  7. The zero mass limit in Yang-Mills theory

    International Nuclear Information System (INIS)

    Dombey, N.

    1976-01-01

    The zero mass limit of massive Yang-Mills theory is investigated and it is shown that there is a conflict between Lorentz invariance and the internal symmetry group in the theory. A necessary but not sufficient condition for the resolution of this conflict is the introduction of zero mass scalar fields. (author)

  8. On the scalar electron mass limit from single photon experiments

    International Nuclear Information System (INIS)

    Grivaz, J.F.

    1987-03-01

    We discuss how the 90% C.L. lower limit on the mass of the scalar electron, as extracted from the single photon experiments, is affected by the way the background from radiative neutrino pair production is handled. We argue that some of the results presented at the Berkeley conference are overoptimistic, and that the mass lower limit is 65 GeV rather than the advertized value of 84 GeV, for the case of degenerate scalar electrons with massless photinos

  9. Limits on neutrino masses from tritium beta decay

    CERN Document Server

    Bonn, J; Bornschein, L; Flatt, B; Kraus, C V; Otten, E W; Schall, J P; Thuemmler, T; Weinheimer, C

    2002-01-01

    The presently lowest limit for the mass of the electron neutrino is m nu < 2.2 eV (95 % C.L.) derived from measurements at Mainz up to 1999. The data taken in 2000 are not fully analyzed yet but limits of possible distortions as reported by the Troitsk group can be given. The next generation neutrino mass experiment KATRIN is briefly discussed.

  10. Electron self-mass in the semiclassical limit

    International Nuclear Information System (INIS)

    Pradham, T.; Khare, A.

    1978-01-01

    The semiclassical limit of the electron self-mass, which is the first order term in an expansion of the exact Dyson self-mass in powers of h/2π, is calculated. The result is quadratically divergent in the limit of the cut-off radius tending to zero. It is noted that the present result is quantum mechanical in the same sense as any WKB result and is exact to all orders in e 2 , in contrast to the logarithmically divergent self-mass given by other resuls. (U.K.)

  11. The high mass frontier: limits on heavy neutrinos

    International Nuclear Information System (INIS)

    Gronau, M.

    1984-01-01

    The theoretical motivation for a search for heavy neutrinos is discussed followed by the presentation of typical model dependent expectations for the mixing of the latter with ordinary neutrinos. Present mass and mixing limits on such heavy neutral leptons are based on search for secondary peaks in π and K leptonic decays and on the absence of neutrino decay signatures in neutrino beams from conventional sources and beam dumps. While these limits are quite poor for masses above 1 GeV, we describe methods to extend the limits to masses in the many GeV region. Such limits may be derived from search in b decays, high statistics neutrino experiments, search in ep colliders, W and Z decays and finally - decays of very heavy gauge bosons (if such exist in the TeV region) when produced in multi-TeV pp and antipp colliders

  12. Avinash-Shukla mass limit for the maximum dust mass supported against gravity by electric fields

    Science.gov (United States)

    Avinash, K.

    2010-08-01

    The existence of a new class of astrophysical objects, where gravity is balanced by the shielded electric fields associated with the electric charge on the dust, is shown. Further, a mass limit MA for the maximum dust mass that can be supported against gravitational collapse by these fields is obtained. If the total mass of the dust in the interstellar cloud MD > MA, the dust collapses, while if MD < MA, stable equilibrium may be achieved. Heuristic arguments are given to show that the physics of the mass limit is similar to the Chandrasekar's mass limit for compact objects and the similarity of these dust configurations with neutron and white dwarfs is pointed out. The effect of grain size distribution on the mass limit and strong correlation effects in the core of such objects is discussed. Possible location of these dust configurations inside interstellar clouds is pointed out.

  13. On the mass of rotating stars in Newtonian gravity and GR

    International Nuclear Information System (INIS)

    Reina, Borja; Vera, Raül

    2016-01-01

    We show how the correction to the calculation of the mass in the original relativistic model of a rotating star by Hartle (1967 Astrophys. J. 150 1005–29), found recently by Reina and Vera (2015 Class. Quantum Grav. 32 155008), appears in the Newtonian limit, and that the correcting term is indeed present, albeit hidden, in the original Newtonian approach by Chandrasekhar (1933 Mon. Not. Roy. Astr. Soc. 93 390–406). (note)

  14. Lower Limits on Soft Supersymmetry-Breaking Scalar Masses

    CERN Document Server

    Ellis, John R.; Olive, Keith A.; Ellis, John; Olive, Keith A.

    2002-01-01

    Working in the context of the CMSSM, we argue that phenomenological constraints now require the universal soft supersymmetry-breaking scalar mass m_0 be non-zero at the input GUT scale. This conclusion is primarily imposed by the LEP lower limit on the Higgs mass and the requirement that the lightest supersymmetric particle not be charged. We find that m_0 > 0 for all tan beta if mu 0 only when tan beta sim 8 and one allows an uncertainty of 3+ GeV in the theoretical calculation of the Higgs mass. Upper limits on flavour-changing neutral interactions in the MSSM squark sector allow substantial violations of non-universality in the m_0 values, even if their magnitudes are comparable to the lower limit we find in the CMSSM. Also, we show that our lower limit on m_0 at the GUT scale in the CMSSM is compatible with the no-scale boundary condition m_0 = 0 at the Planck scale.

  15. Feedback Limits to Maximum Seed Masses of Black Holes

    International Nuclear Information System (INIS)

    Pacucci, Fabio; Natarajan, Priyamvada; Ferrara, Andrea

    2017-01-01

    The most massive black holes observed in the universe weigh up to ∼10 10 M ⊙ , nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M • ≳ 10 4 M ⊙ ) hosted in small isolated halos ( M h ≲ 10 9 M ⊙ ) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M • – σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10 4–6 M ⊙ , we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  16. Large mass limit of the continuum theories in Kaplan's formulation

    International Nuclear Information System (INIS)

    Kawano, T.; Kikukawa, Y.

    1994-01-01

    Being inspired by Kaplan's proposal for simulating chiral fermions on a lattice, we examine the continuum analogue of his domain-wall construction for two-dimensional chiral Schwinger models. Adopting a slightly unusual dimensional regularization, we explicitly evaluate the one-loop effective action in the limit that the domain-wall mass goes to infinity. For anomaly-free cases, the effective action turns out to be gauge invariant in the two-dimensional sense

  17. Rigorous quantum limits on monitoring free masses and harmonic oscillators

    Science.gov (United States)

    Roy, S. M.

    2018-03-01

    There are heuristic arguments proposing that the accuracy of monitoring position of a free mass m is limited by the standard quantum limit (SQL): σ2( X (t ) ) ≥σ2( X (0 ) ) +(t2/m2) σ2( P (0 ) ) ≥ℏ t /m , where σ2( X (t ) ) and σ2( P (t ) ) denote variances of the Heisenberg representation position and momentum operators. Yuen [Phys. Rev. Lett. 51, 719 (1983), 10.1103/PhysRevLett.51.719] discovered that there are contractive states for which this result is incorrect. Here I prove universally valid rigorous quantum limits (RQL), viz. rigorous upper and lower bounds on σ2( X (t ) ) in terms of σ2( X (0 ) ) and σ2( P (0 ) ) , given by Eq. (12) for a free mass and by Eq. (36) for an oscillator. I also obtain the maximally contractive and maximally expanding states which saturate the RQL, and use the contractive states to set up an Ozawa-type measurement theory with accuracies respecting the RQL but beating the standard quantum limit. The contractive states for oscillators improve on the Schrödinger coherent states of constant variance and may be useful for gravitational wave detection and optical communication.

  18. Composition gradients across spiral galaxies II. The stellar mass limit

    International Nuclear Information System (INIS)

    Shields, G.A.; Tinsley, B.M.

    1976-01-01

    The equivalent width of the Hβ emission from H ii regions in spiral galaxies increases with distance from the nucleus. This W (Hβ) gradient is interpreted in terms of a radial gradient in the temperature of the hottest exciting stars. (T/subu/). From Searle's observations of M101, an increase Δ log T/subu/=0.02--0.13 from the intermediate to outermost spiral arms of M101 is inferred. There is also a radial decrease in the metal abundance (Z) across M101, and the T/subu/ gradient is consistent with the prediction of Kahn's recent theory that the upper mass limit for star formation should be smaller in regions of high Z. It is noted also that, even in the absence of changes in the upper mass limit, a T/subu/ gradient is expected because metal-rich stars of given mass have smaller effective temperatures. Several observational and theoretical improvements are needed before firm conclusions can be drawn, but it is clear that the presence of a T/subu/ gradient may lead to several important systematic changes in the interpretation of gradients in the properties of H ii regions across galaxies. A T/subu/ gradient reduces the Z gradient that is inferred from emission-line ratios, and it may help to explain why O ii is strong in the innermost regions where O iii is weak. A T/subu/ gradient may also partly camouflage a helium abundance gradient

  19. Quantum limits to center-of-mass measurements

    International Nuclear Information System (INIS)

    Vaughan, Timothy; Drummond, Peter; Leuchs, Gerd

    2007-01-01

    We discuss the issue of measuring the mean position (center of mass) of a group of bosonic or fermionic quantum particles, including particle number fluctuations. We introduce a standard quantum limit for these measurements at ultralow temperatures, and discuss this limit in the context of both photons and ultracold atoms. In the case of non-interacting harmonically trapped fermions, we present evidence that the Pauli exclusion principle has a strongly beneficial effect, giving rise to a 1/N scaling in the position standard deviation--as opposed to a 1/√(N) scaling for bosons. The difference between the actual mean-position fluctuation and this limit is evidence for quantum wave-packet spreading in the center of mass. This macroscopic quantum effect cannot be readily observed for noninteracting particles, due to classical pulse broadening. For this reason, we also study the evolution of photonic and matter-wave solitons, where classical dispersion is suppressed. In the photonic case, we show that the intrinsic quantum diffusion of the mean position can contribute significantly to uncertainties in soliton pulse arrival times. We also discuss ways in which the relatively long lifetimes of attractive bosons in matter-wave solitons may be used to demonstrate quantum interference between massive objects composed of thousands of particles

  20. Force Limited Random Vibration Test of TESS Camera Mass Model

    Science.gov (United States)

    Karlicek, Alexandra; Hwang, James Ho-Jin; Rey, Justin J.

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a spaceborne instrument consisting of four wide field-of-view-CCD cameras dedicated to the discovery of exoplanets around the brightest stars. As part of the environmental testing campaign, force limiting was used to simulate a realistic random vibration launch environment. While the force limit vibration test method is a standard approach used at multiple institutions including Jet Propulsion Laboratory (JPL), NASA Goddard Space Flight Center (GSFC), European Space Research and Technology Center (ESTEC), and Japan Aerospace Exploration Agency (JAXA), it is still difficult to find an actual implementation process in the literature. This paper describes the step-by-step process on how the force limit method was developed and applied on the TESS camera mass model. The process description includes the design of special fixtures to mount the test article for properly installing force transducers, development of the force spectral density using the semi-empirical method, estimation of the fuzzy factor (C2) based on the mass ratio between the supporting structure and the test article, subsequent validating of the C2 factor during the vibration test, and calculation of the C.G. accelerations using the Root Mean Square (RMS) reaction force in the spectral domain and the peak reaction force in the time domain.

  1. Feedback Limits to Maximum Seed Masses of Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Pacucci, Fabio; Natarajan, Priyamvada [Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Ferrara, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

    2017-02-01

    The most massive black holes observed in the universe weigh up to ∼10{sup 10} M {sub ⊙}, nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M {sub •} ≳ 10{sup 4} M {sub ⊙}) hosted in small isolated halos ( M {sub h} ≲ 10{sup 9} M {sub ⊙}) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M {sub •}– σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10{sup 4–6} M {sub ⊙}, we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  2. Black hole fusion in the extreme mass ratio limit

    Science.gov (United States)

    Emparan, Roberto; Martínez, Marina; Zilhão, Miguel

    2018-02-01

    We present a simple, general, and accurate construction of the event horizons for the fusion of two neutral, rotating black holes with arbitrary orientation and values of their spins, in the extreme mass ratio limit where one black hole is much larger than the other. We compute several parameters that characterize the fusion and investigate their dependence on the black hole spin and orientation axis. We also exhibit and study the appearance of transient toroidal topology of the horizon. An earlier conjecture about universal critical exponents before and after an axisymmetric pinch is proven.

  3. Analytic Models of Brown Dwarfs and the Substellar Mass Limit

    Directory of Open Access Journals (Sweden)

    Sayantan Auddy

    2016-01-01

    Full Text Available We present the analytic theory of brown dwarf evolution and the lower mass limit of the hydrogen burning main-sequence stars and introduce some modifications to the existing models. We give an exact expression for the pressure of an ideal nonrelativistic Fermi gas at a finite temperature, therefore allowing for nonzero values of the degeneracy parameter. We review the derivation of surface luminosity using an entropy matching condition and the first-order phase transition between the molecular hydrogen in the outer envelope and the partially ionized hydrogen in the inner region. We also discuss the results of modern simulations of the plasma phase transition, which illustrate the uncertainties in determining its critical temperature. Based on the existing models and with some simple modification, we find the maximum mass for a brown dwarf to be in the range 0.064M⊙–0.087M⊙. An analytic formula for the luminosity evolution allows us to estimate the time period of the nonsteady state (i.e., non-main-sequence nuclear burning for substellar objects. We also calculate the evolution of very low mass stars. We estimate that ≃11% of stars take longer than 107 yr to reach the main sequence, and ≃5% of stars take longer than 108 yr.

  4. Phosphoproteomics by mass spectrometry: insights, implications, applications and limitations.

    Science.gov (United States)

    Mayya, Viveka; Han, David K

    2009-12-01

    Phosphorylation of proteins is a predominant, reversible post-translational modification. It is central to a wide variety of physiological responses and signaling mechanisms. Recent advances have allowed the global scope of phosphorylation to be addressed by mass spectrometry using phosphoproteomic approaches. In this perspective, we discuss four aspects of phosphoproteomics: the insights and implications from recently published phosphoproteomic studies and the applications and limitations of current phosphoproteomic strategies. Since approximately 50,000 known phosphorylation sites do not yet have any ascribed function, we present our perspectives on a major function of protein phosphorylation that may be of predictive value in hypothesis-based investigations. Finally, we discuss strategies to measure the stoichiometry of phosphorylation in a proteome-wide manner that is not provided by current phosphoproteomic approaches.

  5. Experimental limit on the ratio of the gravitational mass to the inertial mass of antihydrogen

    Science.gov (United States)

    Fajans, Joel; Wurtele, Jonathan; Charman, Andrew; Zhmoginov, Andrey

    2012-10-01

    Physicists have long wondered if the gravitational interactions between matter and antimatter might be different from those between matter and itself. While there are many indirect indications that no such differences exist, i.e., that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. By searching for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap, we have determined that we can reject ratios of the gravitational mass to the inertial mass of antihydrogen greater than about 100 at a statistical significance level of 5%. A similar search places somewhat lower limits on a negative gravitational mass, i.e., on antigravity.

  6. Plutonium Critical Mass Curve Comparison to Mass at Upper Subcritical Limit (USL) Using Whisper

    International Nuclear Information System (INIS)

    Alwin, Jennifer Louise; Zhang, Ning

    2016-01-01

    Whisper is computational software designed to assist the nuclear criticality safety analyst with validation studies with the MCNP ® Monte Carlo radiation transport package. Standard approaches to validation rely on the selection of benchmarks based upon expert judgment. Whisper uses sensitivity/uncertainty (S/U) methods to select relevant benchmarks to a particular application or set of applications being analyzed. Using these benchmarks, Whisper computes a calculational margin. Whisper attempts to quantify the margin of subcriticality (MOS) from errors in software and uncertainties in nuclear data. The combination of the Whisper-derived calculational margin and MOS comprise the baseline upper subcritical limit (USL), to which an additional margin may be applied by the nuclear criticality safety analyst as appropriate to ensure subcriticality. A series of critical mass curves for plutonium, similar to those found in Figure 31 of LA-10860-MS, have been generated using MCNP6.1.1 and the iterative parameter study software, WORM S olver. The baseline USL for each of the data points of the curves was then computed using Whisper 1.1. The USL was then used to determine the equivalent mass for plutonium metal-water system. ANSI/ANS-8.1 states that it is acceptable to use handbook data, such as the data directly from the LA-10860-MS, as it is already considered validated (Section 4.3 4) ''Use of subcritical limit data provided in ANSI/ANS standards or accepted reference publications does not require further validation.''). This paper attempts to take a novel approach to visualize traditional critical mass curves and allows comparison with the amount of mass for which the k eff is equal to the USL (calculational margin + margin of subcriticality). However, the intent is to plot the critical mass data along with USL, not to suggest that already accepted handbook data should have new and more rigorous requirements for validation.

  7. Maximum mass of magnetic white dwarfs

    International Nuclear Information System (INIS)

    Paret, Daryel Manreza; Horvath, Jorge Ernesto; Martínez, Aurora Perez

    2015-01-01

    We revisit the problem of the maximum masses of magnetized white dwarfs (WDs). The impact of a strong magnetic field on the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into parallel and perpendicular components. We first construct stable solutions of the Tolman-Oppenheimer-Volkoff equations for parallel pressures and find that physical solutions vanish for the perpendicular pressure when B ≳ 10 13 G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WDs with super-Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we can apply results for structure equations appropriate for a cylindrical metric with anisotropic pressures that were derived in our previous work. From the solutions of the structure equations in cylindrical symmetry we have confirmed the same bound for B ∼ 10 13 G, since beyond this value no physical solutions are possible. Our tentative conclusion is that massive WDs with masses well beyond the Chandrasekhar limit do not constitute stable solutions and should not exist. (paper)

  8. New Ideas and Fertility Limitation: The Role of Mass Media

    Science.gov (United States)

    Barber, Jennifer S.; Axinn, William G.

    2004-01-01

    This article investigates the mass media as a social change that shapes individual behavior primarily via ideational mechanisms. We construct a theoretical framework drawing on social demography and social psychology to explain how mass media may affect behavior via attitudinal change. Empirical analyses of 1,091 couples in the Chitwan Valley…

  9. Dynamical limits on dark mass in the outer solar system

    International Nuclear Information System (INIS)

    Hogg, D.W.; Quinlan, G.D.; Tremaine, S.

    1991-01-01

    Simplified model solar systems with known observational errors are considered in conducting a dynamical search for dark mass and its minimum detectable amount, and in determining the significance of observed anomalies. The numerical analysis of the dynamical influence of dark mass on the orbits of outer planets and comets is presented in detail. Most conclusions presented are based on observations of the four giant planets where the observational errors in latitude and longitude are independent Gaussian variables with a standard deviation. Neptune's long orbital period cannot be predicted by modern ephemerides, and no evidence of dark mass is found in considering this planet. Studying the improvement in fit when observations are fitted to models that consider dark mass is found to be an efficient way to detect dark mass. Planet X must have a mass of more than about 10 times the minimum detectable mass to locate the hypothetical planet. It is suggested that the IRAS survey would have already located the Planet X if it is so massive and close that it dynamically influences the outer planets. Orbital residuals from comets are found to be more effective than those from planets in detecting the Kuiper belt. 35 refs

  10. LOW MACH NUMBER MODELING OF CONVECTION IN HELIUM SHELLS ON SUB-CHANDRASEKHAR WHITE DWARFS. II. BULK PROPERTIES OF SIMPLE MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, A. M.; Zingale, M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Nonaka, A.; Almgren, A. S.; Bell, J. B. [Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-08-10

    The dynamics of helium shell convection driven by nuclear burning establish the conditions for runaway in the sub-Chandrasekhar-mass, double-detonation model for SNe Ia, as well as for a variety of other explosive phenomena. We explore these convection dynamics for a range of white dwarf core and helium shell masses in three dimensions using the low Mach number hydrodynamics code MAESTRO. We present calculations of the bulk properties of this evolution, including time-series evolution of global diagnostics, lateral averages of the 3D state, and the global 3D state. We find a variety of outcomes, including quasi-equilibrium, localized runaway, and convective runaway. Our results suggest that the double-detonation progenitor model is promising and that 3D dynamic convection plays a key role.

  11. A new way of obtaining analytic approximations of Chandrasekhar's H function

    International Nuclear Information System (INIS)

    Vukanic, J.; Arsenovic, D.; Davidovic, D.

    2007-01-01

    Applying the mean value theorem for definite integrals in the non-linear integral equation for Chandrasekhar's H function describing conservative isotropic scattering, we have derived a new, simple analytic approximation for it, with a maximal relative error below 2.5%. With this new function as a starting-point, after a single iteration in the corresponding integral equation, we have obtained a new, highly accurate analytic approximation for the H function. As its maximal relative error is below 0.07%, it significantly surpasses the accuracy of other analytic approximations

  12. EROS and MACHO combined limits on planetary-mass dark matter in the galactic halo

    NARCIS (Netherlands)

    Alcock, C; Allsman, RA; Alves, D; Ansari, R; Aubourg, E; Axelrod, TS; Bareyre, P; Beaulieu, JP; Becker, AC; Bennett, DP; Brehin, S; Cavalier, F; Char, S; Cook, KH; Ferlet, R; Fernandez, J; Freeman, KC; Griest, K; Grison, P; Gros, M; Gry, C; Guibert, J; Lachieze-Rey, M; Laurent, B; Lehner, MJ; Lesquoy, E; Magneville, C; Marshall, SL; Maurice, E; Milsztajn, A; Minniti, D; Moniez, M; Moreau, O; Moscoso, L; Palanque-Delabrouille, N; Peterson, BA; Pratt, MR; Prevot, L; Queinnec, F; Quinn, PJ; Renault, C; Rich, J; Spiro, M; Stubbs, CW; Sutherland, W; Tomaney, A; Vandehei, T; Vidal-Madjar, A; Vigroux, L; Zylberajch, S

    1998-01-01

    The EROS and MACHO collaborations have each published upper limits on the amount of planetary-mass dark matter in the Galactic halo obtained from gravitational microlensing searches. In this Letter, the two limits are combined to give a much stronger constraint on the abundance of low-mass MACHOs.

  13. Neutron-star mass limit in the bimetric theory of gravitation

    International Nuclear Information System (INIS)

    Caporaso, G.; Brecher, K.

    1977-01-01

    The ''neutron''-star upper mass limit is examined in Rosen's bimetric theory of gravitation. An exact solution, approximate scaling law, and numerical integration of the hydrostatic equilibrium equation show the dependence of the mass limit on the assumed equation of state. As in general relativity, that limit varies roughly as 1/√rho 0 , where rho 0 is the density above which the equation of state becomes ''stiff.'' Unlike general relativity, the stiffer the equation of state, the higher the mass limit. For rho 0 = 2 x 10 14 g/cm 3 and P = (rho - rho 0 ) c 2 , we found M/sub max/ = 81M/sub sun/. This mass is consistent with causality and experimental tests of gravitation and nuclear physics. For dp/drho > c 2 it appears that the upper mass limit can become arbitrarily large

  14. Effect of minimal length uncertainty on the mass-radius relation of white dwarfs

    Science.gov (United States)

    Mathew, Arun; Nandy, Malay K.

    2018-06-01

    Generalized uncertainty relation that carries the imprint of quantum gravity introduces a minimal length scale into the description of space-time. It effectively changes the invariant measure of the phase space through a factor (1 + βp2) - 3 so that the equation of state for an electron gas undergoes a significant modification from the ideal case. It has been shown in the literature (Rashidi 2016) that the ideal Chandrasekhar limit ceases to exist when the modified equation of state due to the generalized uncertainty is taken into account. To assess the situation in a more complete fashion, we analyze in detail the mass-radius relation of Newtonian white dwarfs whose hydrostatic equilibria are governed by the equation of state of the degenerate relativistic electron gas subjected to the generalized uncertainty principle. As the constraint of minimal length imposes a severe restriction on the availability of high momentum states, it is speculated that the central Fermi momentum cannot have values arbitrarily higher than pmax ∼β - 1 / 2. When this restriction is imposed, it is found that the system approaches limiting mass values higher than the Chandrasekhar mass upon decreasing the parameter β to a value given by a legitimate upper bound. Instead, when the more realistic restriction due to inverse β-decay is considered, it is found that the mass and radius approach the values 1.4518 M⊙ and 601.18 km near the legitimate upper bound for the parameter β.

  15. Stringent limits on the ionized mass loss from A and F dwarfs

    International Nuclear Information System (INIS)

    Brown, A.; Veale, A.; Judge, P.; Bookbinder, J.A.; Hubeny, I.

    1990-01-01

    Following the suggestion of Willson et al. (1987) that A- and F-type main-sequence stars might undergo significant mass loss due to pulsationally driven winds, upper limits to the ionized mass loss from A and F dwarfs have been obtained using VLA observations. These stringent upper limits show that the level of ionized mass loss would have at most only a small effect on stellar evolution. Radiative-equilibrium atmospheric and wind models for early A dwarfs indicate that it is highly likely that a wind flowing from such stars would be significantly ionized. In addition, late A and early F dwarfs exhibit chromospheric emission indicative of significant nonradiative heating. The present mass-loss limits are thus representative of the total mass-loss rates for these stars. It is concluded that A and F dwarfs are not losing sufficient mass to cause A dwarfs to evolve into G dwarfs. 24 refs

  16. Limited-sequence magnetic resonance imaging in the evaluation of the ultrasonographically indeterminate pelvic mass

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.D. [Univ. of British Columbia, Vancouver Hospital and Helath Services Centre, Dept. of Radiology, Vancouver, British Columbia (Canada)]. E-mail: schang@vanhosp.bc.ca; Cooperberg, P.L.; Wong, A.D. [Univ. of British Columbia, St. Paul' s Hospital, Dept. of Radiology, Vancouver, British Columbia (Canada); Llewellyn, P.A. [Lion' s Gate Hospital, Dept. of Radiology, North Vancouver, British Columbia (Canada); Bilbey, J.H. [Royal Inland Hospital, Dept. of Radiology, Kamloops, British Columbia (Canada)

    2004-04-01

    To evaluate the usefulness of limited-sequence magnetic resonance imaging (MRI) in the elucidation of ultrasonographically indeterminate pelvic masses. This study focused only on pelvic masses in which the origin of the mass (uterine v. extrauterine) could not be determined by ultrasonography (US). The origin of a pelvic mass has clinical implications. A mass arising from the uterus is most likely to be a leiomyoma, which is a benign lesion, whereas an extrauterine mass will have a higher likelihood of malignancy and usually requires surgery. Eighty-one female patients whose pelvic mass was of indeterminate origin on US also underwent limited-sequence MRI of the pelvis. Most of the MRI examinations were performed on the same day as the US. Limited-sequence MRI sequences included a quick gradient-echoT{sub 1}-weighted localizer and a fast spin-echoT{sub 2}-weighted sequence. Final diagnoses were established by surgical pathology or by clinical and imaging follow-up. Limited-sequence MRI was helpful in 79 of the 81 cases (98%). Fifty-two of the 81 masses (64%) were leiomyomas. One was a leiomyosarcoma. The extrauterine masses (26/81 [32%]) were identified as 14 ovarian malignancies, 4 endometriomas, 3 dermoids, an ovarian fibroma, an infarcted fibrothecoma, an infarcted hemorrhagic cyst, a sigmoid diverticular abscess and a gastrointestinal stromal tumour of the ileum. In the other 2 cases (2/81 [2%]), the origin of the pelvic mass remained indeterminate. Both of these indeterminate masses showed low signal onT{sub 2}-weighted images and were interpreted as probable leiomyomas. They were not surgically removed but were followed clinically and had a stable course. Limited-sequence MRI is a quick and efficient way to further evaluate ultrasonographically indeterminate pelvic masses. Limited-sequence MRI of the pelvis can suffice, in these cases, without requiring a full MRI examination. (author)

  17. Limited-sequence magnetic resonance imaging in the evaluation of the ultrasonographically indeterminate pelvic mass

    International Nuclear Information System (INIS)

    Chang, S.D.; Cooperberg, P.L.; Wong, A.D.; Llewellyn, P.A.; Bilbey, J.H.

    2004-01-01

    To evaluate the usefulness of limited-sequence magnetic resonance imaging (MRI) in the elucidation of ultrasonographically indeterminate pelvic masses. This study focused only on pelvic masses in which the origin of the mass (uterine v. extrauterine) could not be determined by ultrasonography (US). The origin of a pelvic mass has clinical implications. A mass arising from the uterus is most likely to be a leiomyoma, which is a benign lesion, whereas an extrauterine mass will have a higher likelihood of malignancy and usually requires surgery. Eighty-one female patients whose pelvic mass was of indeterminate origin on US also underwent limited-sequence MRI of the pelvis. Most of the MRI examinations were performed on the same day as the US. Limited-sequence MRI sequences included a quick gradient-echoT 1 -weighted localizer and a fast spin-echoT 2 -weighted sequence. Final diagnoses were established by surgical pathology or by clinical and imaging follow-up. Limited-sequence MRI was helpful in 79 of the 81 cases (98%). Fifty-two of the 81 masses (64%) were leiomyomas. One was a leiomyosarcoma. The extrauterine masses (26/81 [32%]) were identified as 14 ovarian malignancies, 4 endometriomas, 3 dermoids, an ovarian fibroma, an infarcted fibrothecoma, an infarcted hemorrhagic cyst, a sigmoid diverticular abscess and a gastrointestinal stromal tumour of the ileum. In the other 2 cases (2/81 [2%]), the origin of the pelvic mass remained indeterminate. Both of these indeterminate masses showed low signal onT 2 -weighted images and were interpreted as probable leiomyomas. They were not surgically removed but were followed clinically and had a stable course. Limited-sequence MRI is a quick and efficient way to further evaluate ultrasonographically indeterminate pelvic masses. Limited-sequence MRI of the pelvis can suffice, in these cases, without requiring a full MRI examination. (author)

  18. Past, present, and possible future limits on the photon rest mass

    International Nuclear Information System (INIS)

    Nieto, M.M.

    1992-01-01

    In an historical context, present limits on the photon rest mass are reviewed. More stringent, yet speculative, limits which have been proposed are mentioned. Finally, new theoretical ideas and possible experimental improvements on the present limits are discussed, along with possible relationships between these two areas

  19. Compact stars with a small electric charge: the limiting radius to mass relation and the maximum mass for incompressible matter

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Jose P.S.; Lopes, Francisco J.; Quinta, Goncalo [Universidade de Lisboa, UL, Departamento de Fisica, Centro Multidisciplinar de Astrofisica, CENTRA, Instituto Superior Tecnico, IST, Lisbon (Portugal); Zanchin, Vilson T. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil)

    2015-02-01

    One of the stiffest equations of state for matter in a compact star is constant energy density and this generates the interior Schwarzschild radius to mass relation and the Misner maximum mass for relativistic compact stars. If dark matter populates the interior of stars, and this matter is supersymmetric or of some other type, some of it possessing a tiny electric charge, there is the possibility that highly compact stars can trap a small but non-negligible electric charge. In this case the radius to mass relation for such compact stars should get modifications. We use an analytical scheme to investigate the limiting radius to mass relation and the maximum mass of relativistic stars made of an incompressible fluid with a small electric charge. The investigation is carried out by using the hydrostatic equilibrium equation, i.e., the Tolman-Oppenheimer-Volkoff (TOV) equation, together with the other equations of structure, with the further hypothesis that the charge distribution is proportional to the energy density. The approach relies on Volkoff and Misner's method to solve the TOV equation. For zero charge one gets the interior Schwarzschild limit, and supposing incompressible boson or fermion matter with constituents with masses of the order of the neutron mass one finds that the maximum mass is the Misner mass. For a small electric charge, our analytical approximating scheme, valid in first order in the star's electric charge, shows that the maximum mass increases relatively to the uncharged case, whereas the minimum possible radius decreases, an expected effect since the new field is repulsive, aiding the pressure to sustain the star against gravitational collapse. (orig.)

  20. An upper limit on the $\\tau$ neutrino mass from three- and five-prong tau decays

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bright-Thomas, P G; Casper, David William; Cattaneo, M; Cerutti, F; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Boccali, T; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Lynch, J G; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Spagnolo, P; Stacey, A M; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Buck, P G; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Sloan, Terence; Williams, M I; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Leroy, O; Motsch, F; Payre, P; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Antonelli, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Mannert, C; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Schune, M H; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Reeve, J; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1998-01-01

    A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at Ecm = M(Z) with the ALEPH detector. Two separate limits are derived by fitting the distribution of visible energy vs invariant mass in tau+ -> pi+ pi+ pi- nu and tau+ -> pi+ pi+ pi- pi- pi+ (pi0) nu decays. The two results are combined to obtain a 95 % confidence level upper limit of 18.2 MeV/c^2 on the mass of the tau neutrino.

  1. Rotational Energy as Mass in H3 + and Lower Limits on the Atomic Masses of D and 3He

    Science.gov (United States)

    Smith, J. A.; Hamzeloui, S.; Fink, D. J.; Myers, E. G.

    2018-04-01

    We have made precise measurements of the cyclotron frequency ratios H3 +/HD+ and H3 +/ 3He+ and observe that different H3+ ions result in different cyclotron frequency ratios. We interpret these differences as due to the molecular rotational energy of H3 + changing its inertial mass. We also confirm that certain high J , K rotational levels of H3+ have mean lifetimes exceeding several weeks. From measurements with the lightest H3+ ion we obtain lower limits on the atomic masses of deuterium and helium-3 with respect to the proton.

  2. Rotational Energy as Mass in H_{3}^{+} and Lower Limits on the Atomic Masses of D and ^{3}He.

    Science.gov (United States)

    Smith, J A; Hamzeloui, S; Fink, D J; Myers, E G

    2018-04-06

    We have made precise measurements of the cyclotron frequency ratios H_{3}^{+}/HD^{+} and H_{3}^{+}/^{3}He^{+} and observe that different H_{3}^{+} ions result in different cyclotron frequency ratios. We interpret these differences as due to the molecular rotational energy of H_{3}^{+} changing its inertial mass. We also confirm that certain high J, K rotational levels of H_{3}^{+} have mean lifetimes exceeding several weeks. From measurements with the lightest H_{3}^{+} ion we obtain lower limits on the atomic masses of deuterium and helium-3 with respect to the proton.

  3. New method for laser driven ion acceleration with isolated, mass-limited targets

    International Nuclear Information System (INIS)

    Paasch-Colberg, T.; Sokollik, T.; Gorling, K.; Eichmann, U.; Steinke, S.; Schnuerer, M.; Nickles, P.V.; Andreev, A.; Sandner, W.

    2011-01-01

    A new technique to investigate laser driven ion acceleration with fully isolated, mass-limited glass spheres with a diameter down to 8μm is presented. A Paul trap was used to prepare a levitating glass sphere for the interaction with a laser pulse of relativistic intensity. Narrow-bandwidth energy spectra of protons and oxygen ions have been observed and were attributed to specific acceleration field dynamics in case of the spherical target geometry. A general limiting mechanism has been found that explains the experimentally observed ion energies for the mass-limited target.

  4. EDDINGTON-LIMITED ACCRETION AND THE BLACK HOLE MASS FUNCTION AT REDSHIFT 6

    International Nuclear Information System (INIS)

    Willott, Chris J.; Crampton, David; Hutchings, John B.; Schade, David; Albert, Loic; Arzoumanian, Doris; Bergeron, Jacqueline; Omont, Alain; Delorme, Philippe; Reyle, Celine

    2010-01-01

    We present discovery observations of a quasar in the Canada-France High-z Quasar Survey (CFHQS) at redshift z = 6.44. We also use near-infrared spectroscopy of nine CFHQS quasars at z ∼ 6 to determine black hole masses. These are compared with similar estimates for more luminous Sloan Digital Sky Survey quasars to investigate the relationship between black hole mass and quasar luminosity. We find a strong correlation between Mg II FWHM and UV luminosity and that most quasars at this early epoch are accreting close to the Eddington limit. Thus, these quasars appear to be in an early stage of their life cycle where they are building up their black hole mass exponentially. Combining these results with the quasar luminosity function, we derive the black hole mass function at z = 6. Our black hole mass function is ∼10 4 times lower than at z = 0 and substantially below estimates from previous studies. The main uncertainties which could increase the black hole mass function are a larger population of obscured quasars at high redshift than is observed at low redshift and/or a low quasar duty cycle at z = 6. In comparison, the global stellar mass function is only ∼10 2 times lower at z = 6 than at z = 0. The difference between the black hole and stellar mass function evolution is due to either rapid early star formation which is not limited by radiation pressure as is the case for black hole growth or inefficient black hole seeding. Our work predicts that the black hole mass-stellar mass relation for a volume-limited sample of galaxies declines rapidly at very high redshift. This is in contrast to the observed increase at 4 < z < 6 from the local relation if one just studies the most massive black holes.

  5. Emden-Chandrasekhar axisymmetric, solid-body rotating polytropes. Pt. 1. Exact solutions for the special cases N = 0, 1 and 5

    Energy Technology Data Exchange (ETDEWEB)

    Caimmi, R [Padua Univ. (Italy). Ist. di Astronomia

    1980-08-01

    The basic theory on polytropes is revisited and EC polytropes are defined. The first-order approximation theory of Chandrasekhar (1933a, b, c) and Chandrasekhar and Lebovitz (1962) is reviewed, refined and extended in such a way that better results are obtained without involving hard analytical or numerical techniques. A more precise equation is given in defining non-outer equipotential surfaces, and a new method is adopted in determining the explicit expression of the gravitational potential.

  6. Mass Transfer Limited Enhanced Bioremediation at Dnapl Source Zones: a Numerical Study

    Science.gov (United States)

    Kokkinaki, A.; Sleep, B. E.

    2011-12-01

    The success of enhanced bioremediation of dense non-aqueous phase liquids (DNAPLs) relies on accelerating contaminant mass transfer from the organic to the aqueous phase, thus enhancing the depletion of DNAPL source zones compared to natural dissolution. This is achieved by promoting biological activity that reduces the contaminant's aqueous phase concentration. Although laboratory studies have demonstrated that high reaction rates are attainable by specialized microbial cultures in DNAPL source zones, field applications of the technology report lower reaction rates and prolonged remediation times. One possible explanation for this phenomenon is that the reaction rates are limited by the rate at which the contaminant partitions from the DNAPL to the aqueous phase. In such cases, slow mass transfer to the aqueous phase reduces the bioavailability of the contaminant and consequently decreases the potential source zone depletion enhancement. In this work, the effect of rate limited mass transfer on bio-enhanced dissolution of DNAPL chlorinated ethenes is investigated through a numerical study. A multi-phase, multi-component groundwater transport model is employed to simulate DNAPL mass depletion for a range of source zone scenarios. Rate limited mass transfer is modeled by a linear driving force model, employing a thermodynamic approach for the calculation of the DNAPL - water interfacial area. Metabolic reductive dechlorination is modeled by Monod kinetics, considering microbial growth and self-inhibition. The model was utilized to identify conditions in which mass transfer, rather than reaction, is the limiting process, as indicated by the bioavailability number. In such cases, reaction is slower than expected, and further increase in the reaction rate does not enhance mass depletion. Mass transfer rate limitations were shown to affect both dechlorination and microbial growth kinetics. The complex dynamics between mass transfer, DNAPL transport and distribution, and

  7. Mass deformed ABJM theory on three sphere in large N limit

    Energy Technology Data Exchange (ETDEWEB)

    Nosaka, Tomoki [Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Shimizu, Kazuma; Terashima, Seiji [Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan)

    2017-03-23

    In this paper the free energy of the mass deformed ABJM theory on S{sup 3} in the large N limit is studied. We find a new solution of the large N saddle point equation which exists for an arbitrary value of the mass parameter, and compute the free energies for these solutions. We also show that the solution corresponding to an asymptotically AdS{sub 4} geometry is singular at a certain value of the mass parameter and does not exist over this critical value. It is not clear that what is the gravity dual of the mass deformed ABJM theory on S{sup 3} for the mass parameter larger than the critical value.

  8. On the zero mass limit of the non linear sigma model in four dimensions

    International Nuclear Information System (INIS)

    Gomes, M.; Koeberle, R.

    The existence of the zero mass limit for the non-linear sigma-model in four dimensions is shown to all orders in renormalized perturbation theory. The main ingredient in the proof is the imposition of many current axial vector Ward identities and the tool used is Lowenstein's momentum-space subtraction procedure. Instead of introducing anisotropic symmetry breaking mass terms, which do not vanish in the symmetry limit, it is necessary to allow for 'soft' anisotropic derivative coupling in order to obtain the correct Ward indentities [pt

  9. On the quantum-mechanical Fokker-Planck and Kramers-Chandrasekhar equation

    International Nuclear Information System (INIS)

    Balazs, N.L.

    1978-01-01

    In the classical theory of Brownian motion the Langevin equation can be considered as an infinitesimal transformation between the coordinates and momenta of a Brownian particle, given probabilistically, since the impulse appearing is characterized by a Gaussian random process. This probabilistic infinitesimal transformation generates a streaming on the distribution function, expressed by the classical Fokker-Planck and Kramers-Chandrasekhar equations. If the laws obeyed by the Brownian particle are quantum mechanical, the Langevin equation can be reinterpreted as an operator relation expressing an infinitesimal transformation of these operators. Since the impulses are independent of the coordinates and momenta one can think of them as c numbers described by a Gaussian random process. The so resulting infinitesimal operator transformation induces a streaming on the density matrix. One may associate, according to Weyl, functions with operators. The function associated with the density matrix is the Wigner function. Expressing, then, these operator relations in terms of these functions the streaming can be expressed as a continuity equation of the Wigner function. It is found that in this parametrization the extra terms which appear are the same as in the classical theory, augmenting the usual Wigner equation. (Auth.)

  10. Determination of external and internal mass transfer limitation in nitrifying microbial aggregates.

    Science.gov (United States)

    Wilén, Britt-Marie; Gapes, Daniel; Keller, Jürg

    2004-05-20

    In this article we present a study of the effects of external and internal mass transfer limitation of oxygen in a nitrifying system. The oxygen uptake rates (OUR) were measured on both a macro-scale with a respirometric reactor using off-gas analysis (Titrimetric and Off-Gas Analysis (TOGA) sensor) and on a micro-scale with microsensors. These two methods provide independent, accurate measurements of the reaction rates and concentration profiles around and in the granules. The TOGA sensor and microsensor measurements showed a significant external mass transfer effect at low dissolved oxygen (DO) concentrations in the bulk liquid while it was insignificant at higher DO concentrations. The oxygen distribution with anaerobic or anoxic conditions in the center clearly shows major mass transfer limitation in the aggregate interior. The large drop in DO concentration of 22-80% between the bulk liquid and aggregate surface demonstrates that the external mass transfer resistance is also highly important. The maximum OUR even for floccular biomass was only attained at much higher DO concentrations (approximately 8 mg/L) than typically used in such systems. For granules, the DO required for maximal activity was estimated to be >20 mg/L, clearly indicating the effects of the major external and internal mass transfer limitations on the overall biomass activity. Smaller aggregates had a larger volumetric OUR indicating that the granules may have a lower activity in the interior part of the aggregate. Copyright 2004 Wiley Periodicals, Inc.

  11. Heterogeneous chemical kinetics by modulated molecular beam mass spectrometry: limitations of technique

    International Nuclear Information System (INIS)

    Olander, D.R.

    1977-01-01

    The advantages and limitations of modulated molecular beam, mass spectrometry as applied to the study of heterogeneous chemical kinetics are reviewed. The process of deducing a model of the surface reaction from experimental data is illustrated by analysis of the hydrogen reduction of uranium dioxide

  12. ''Anomalous'' air showers from point sources: Mass limits and light curves

    International Nuclear Information System (INIS)

    Domokos, G.; Elliott, B.; Kovesi-Domokos, S.

    1993-01-01

    We describe a method to obtain upper limits on the mass of the primaries of air showers associated with point sources. One also obtains the UHE pulse shape of a pulsar if its period is observed in the signal. As an example, we analyze the data obtained during a recent burst of Hercules-X1

  13. SITE-94. CAMEO: A model of mass-transport limited general corrosion of copper canisters

    International Nuclear Information System (INIS)

    Worgan, K.J.; Apted, M.J.

    1996-12-01

    This report describes the technical basis for the CAMEO code, which models the general, uniform corrosion of a copper canister either by transport of corrodants to the canister, or by transport of corrosion products away from the canister. According to the current Swedish concept for final disposal of spent nuclear fuels, extremely long containment times are achieved by thick (60-100 mm) copper canisters. Each canister is surrounded by a compacted bentonite buffer, located in a saturated, crystalline rock at a depth of around 500 m below ground level. Three diffusive transport-limited cases are identified for general, uniform corrosion of copper: General corrosion rate-limited by diffusive mass-transport of sulphide to the canister surface under reducing conditions; General corrosion rate-limited by diffusive mass-transport of oxygen to the canister surface under mildly oxidizing conditions; General corrosion rate-limited by diffusive mass-transport of copper chloride away from the canister surface under highly oxidizing conditions. The CAMEO code includes general corrosion models for each of the above three processes. CAMEO is based on the well-tested CALIBRE code previously developed as a finite-difference, mass-transfer analysis code for the SKI to evaluate long-term radionuclide release and transport in the near-field. A series of scoping calculations for the general, uniform corrosion of a reference copper canister are presented

  14. Search for high-mass diphoton states and limits on Randall-Sundrum gravitons at CDF.

    Science.gov (United States)

    Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; 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; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, 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; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, 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; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; 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; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; 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; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; 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; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; 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; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; 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; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; 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; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; 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; Zhang, X; Zhou, J; Zucchelli, S

    2007-10-26

    We have performed a search for new particles which decay to two photons using 1.2 fb(-1) of integrated luminosity from pp[over] collisions at square root s = 1.96 TeV collected using the CDF II detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230 GeV/c(2) and 850 GeV/c(2), at the 95% confidence level, for coupling parameters (k/M[over](Pl)) of 0.01 and 0.1, respectively.

  15. Improved squark and gluino mass limits from searches for supersymmetry at hardon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Beenakker, Wim; Niessen, Irene [Theoretical High Energy Physics, IMAPP, Nijmegen (Netherlands); Brensing, Silja [DESY, Hamburg (Germany). Theory Group; D' Onofrio, Monica [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Kraemer, Michael; Kulesza, Anna [RWTH Aachen Univ. (Germany). Inst. for Theoretical Particle Physics and Cosmology; Laenen, Eric [ITFA, Amsterdam Univ. (Netherlands); Nikhef, Amsterdam (Netherlands); ITF, Utrecht Univ. (Netherlands); Martinez, Mario [Barcelona Univ., Bellaterra (Spain). ICREA and Inst. de Fisica d' Altes Energies, IFAE

    2011-09-15

    Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the squark and gluino masses. We present an improved analysis of squark and gluino mass bounds which is based on state-of-the-art cross section calculations including the summation of large threshold corrections. For illustration, we consider experimental data obtained by the CDF collaboration at the Fermilab Tevatron and discuss the impact of the improved cross section predictions on the squark and gluino mass limits. (orig.)

  16. Improved squark and gluino mass limits from searches for supersymmetry at hardon colliders

    International Nuclear Information System (INIS)

    Beenakker, Wim; Niessen, Irene; Brensing, Silja; Martinez, Mario

    2011-09-01

    Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the squark and gluino masses. We present an improved analysis of squark and gluino mass bounds which is based on state-of-the-art cross section calculations including the summation of large threshold corrections. For illustration, we consider experimental data obtained by the CDF collaboration at the Fermilab Tevatron and discuss the impact of the improved cross section predictions on the squark and gluino mass limits. (orig.)

  17. Aerosol quantification with the Aerodyne Aerosol Mass Spectrometer: detection limits and ionizer background effects

    Directory of Open Access Journals (Sweden)

    S. Borrmann

    2009-02-01

    Full Text Available Systematic laboratory experiments were performed to investigate quantification of various species with two versions of the Aerodyne Aerosol Mass Spectrometer, a Quadrupole Aerosol Mass Spectrometer (Q-AMS and a compact Time-of-Flight Aerosol Mass Spectrometer (c-ToF-AMS. Here we present a new method to continuously determine the detection limits of the AMS analyzers during regular measurements, yielding detection limit (DL information under various measurement conditions. Minimum detection limits range from 0.03 μg m−3 (nitrate, sulfate, and chloride up to 0.5 μg m−3 (organics for the Q-AMS. Those of the c-ToF-AMS are found between 0.003 μg m−3 (nitrate, sulfate and 0.03 μg m−3 (ammonium, organics. The DL values found for the c-ToF-AMS were ~10 times lower than those of the Q-AMS, mainly due to differences in ion duty cycle. Effects causing an increase of the detection limits include long-term instrument contamination, measurement of high aerosol mass concentrations and short-term instrument history. The self-cleaning processes which reduce the instrument background after measurement of large aerosol concentrations as well as the influences of increased instrument background on mass concentration measurements are discussed. Finally, improvement of detection limits by extension of averaging time intervals, selected or reduced ion monitoring, and variation of particle-to-background measurement ratio are investigated.

  18. On the mass ejected by supernova explosions

    International Nuclear Information System (INIS)

    Bohigas, J.

    1984-01-01

    A simple model is developed in order to calculate the mass ejected by superonovae. We find that the 185, 1006, 1572 and 1604 AD events, all of them classified as either probable or possible type I supernovae, ejected between 0.1 and 0.4 solar masses with an expansion velocity of roughly 10,000 km s -1 . This range of masses suggests that a collapsed object is at the center of the remnants produced by these supernovae if the precursor was a white dwarf whose mass was closed to the Chandrasekhar limit. For the Crab we obtain an ejected mass of 0.45 Msub(sun) and point out that this value is not in contradiction with a proposal in which the moderate helium stars are good candidates for producing this kind of supernovae. Finally we obtain an ejected mass of 3.1 Msub(sun) for Cas A, indicating that a type II event produced this remnant. This ejected mass is closed to what would be expected for a progenitor like an OBN star. (author)

  19. A lower limit on the dark particle mass from dSphs

    Energy Technology Data Exchange (ETDEWEB)

    Angus, G.W., E-mail: angus@ph.unito.it [Dipartimento di Fisica Generale ' ' Amedeo Avogadro' ' , Università degli Studi di Torino, Via P. Giuria 1, I-10125, Torino (Italy)

    2010-03-01

    We use dwarf spheroidal galaxies as a tool to attempt to put precise lower limits on the mass of the dark matter particle, assuming it is a sterile neutrino. We begin by making cored dark halo fits to the line of sight velocity dispersions as a function of projected radius (taken from Walker et al. 2007) for six of the Milky Way's dwarf spheroidal galaxies. We test Osipkov-Merritt velocity anisotropy profiles, but find that no benefit is gained over constant velocity anisotropy. In contrast to previous attempts, we do not assume any relation between the stellar velocity dispersions and the dark matter ones, but instead we solve directly for the sterile neutrino velocity dispersion at all radii by using the equation of state for a partially degenerate neutrino gas (which ensures hydrostatic equilibrium of the sterile neutrino halo). This yields a 1:1 relation between the sterile neutrino density profile and the velocity dispersion profile, and therefore gives us an accurate estimate of the Tremaine-Gunn limit at all radii. By varying the sterile neutrino particle mass, we locate the minimum mass for all six dwarf spheroidals such that the Tremaine-Gunn limit is not exceeded at any radius (in particular at the centre). We find sizeable differences between the ranges of feasible sterile neutrino particle mass for each dwarf, but interestingly there exists a small range 270-280eV which is consistent with all dSphs at the 1-σ level.

  20. A lower limit on the dark particle mass from dSphs

    International Nuclear Information System (INIS)

    Angus, G.W.

    2010-01-01

    We use dwarf spheroidal galaxies as a tool to attempt to put precise lower limits on the mass of the dark matter particle, assuming it is a sterile neutrino. We begin by making cored dark halo fits to the line of sight velocity dispersions as a function of projected radius (taken from Walker et al. 2007) for six of the Milky Way's dwarf spheroidal galaxies. We test Osipkov-Merritt velocity anisotropy profiles, but find that no benefit is gained over constant velocity anisotropy. In contrast to previous attempts, we do not assume any relation between the stellar velocity dispersions and the dark matter ones, but instead we solve directly for the sterile neutrino velocity dispersion at all radii by using the equation of state for a partially degenerate neutrino gas (which ensures hydrostatic equilibrium of the sterile neutrino halo). This yields a 1:1 relation between the sterile neutrino density profile and the velocity dispersion profile, and therefore gives us an accurate estimate of the Tremaine-Gunn limit at all radii. By varying the sterile neutrino particle mass, we locate the minimum mass for all six dwarf spheroidals such that the Tremaine-Gunn limit is not exceeded at any radius (in particular at the centre). We find sizeable differences between the ranges of feasible sterile neutrino particle mass for each dwarf, but interestingly there exists a small range 270-280eV which is consistent with all dSphs at the 1-σ level

  1. Sub-seasonal thaw slump mass wasting is not consistently energy limited at the landscape scale

    Directory of Open Access Journals (Sweden)

    S. Zwieback

    2018-02-01

    Full Text Available Predicting future thaw slump activity requires a sound understanding of the atmospheric drivers and geomorphic controls on mass wasting across a range of timescales. On sub-seasonal timescales, sparse measurements indicate that mass wasting at active slumps is often limited by the energy available for melting ground ice, but other factors such as rainfall or the formation of an insulating veneer may also be relevant. To study the sub-seasonal drivers, we derive topographic changes from single-pass radar interferometric data acquired by the TanDEM-X satellites. The estimated elevation changes at 12 m resolution complement the commonly observed planimetric retreat rates by providing information on volume losses. Their high vertical precision (around 30 cm, frequent observations (11 days and large coverage (5000 km2 allow us to track mass wasting as drivers such as the available energy change during the summer of 2015 in two study regions. We find that thaw slumps in the Tuktoyaktuk coastlands, Canada, are not energy limited in June, as they undergo limited mass wasting (height loss of around 0 cm day−1 despite the ample available energy, suggesting the widespread presence of early season insulating snow or debris veneer. Later in summer, height losses generally increase (around 3 cm day−1, but they do so in distinct ways. For many slumps, mass wasting tracks the available energy, a temporal pattern that is also observed at coastal yedoma cliffs on the Bykovsky Peninsula, Russia. However, the other two common temporal trajectories are asynchronous with the available energy, as they track strong precipitation events or show a sudden speed-up in late August respectively. The observed temporal patterns are poorly related to slump characteristics like the headwall height. The contrasting temporal behaviour of nearby thaw slumps highlights the importance of complex local and temporally varying controls on mass wasting.

  2. 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

  3. Improved limit on the electron anti neutrino rest mass from tritium β decay

    International Nuclear Information System (INIS)

    Weinheimer, C.; Przyrembel, M.; Backe, H.; Barth, H.; Bonn, J.; Degen, B.; Edling, T.; Fischer, H.; Fleischmann, L.; Grooss, J.U.; Haid, R.; Hermanni, A.; Kube, G.; Loeken, T.; Molz, A.; Osipowicz, A.; Otten, E.W.; Picard, A.; Schrader, M.; Steininger, M.

    1993-01-01

    This paper presents the results of a re-measurement of the endpoint region of the beta-spectrum of tritium by an electrostatic spectrometer with magnetic guiding field. It enables the search for a rest mass of the electron anti neutrino with improved precision. The result is: m ν 2 =(-39±34 stat ±15 syst ) (eV/c 2 ) 2 , from which an upper limit of: m ν 2 may be derived. The experiment yields the atomic mass difference: m(T)-m( 3 He)=(18591±3) eV/c 2 . (TEC). 31 refs., 4 figs., 3 tabs

  4. Mass Limit for the standard model Higgs boson with the full LEP I ALEPH data sample

    CERN Document Server

    Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Büscher, V; Cowan, G D; Grupen, Claus; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    background from the electroweak process e+e- --> l+ l- q qbar. This search results in a 95% C.L. lower limit on the Higgs boson mass of $63.9$~\\Gcs. The reaction e+e- --> HZ* is used to search for the standard model Higgs boson in the H nu nubar and the H l+ l- channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the H mu+ mu- channel, in agreement with the expected

  5. New limits on the mass of neutral Higgses in general models

    International Nuclear Information System (INIS)

    Comelli, D.

    1996-07-01

    In general electroweak models with weakly coupled (and otherwise arbitrary) Higgs sector there always exists in the spectrum a scalar state with mass controlled by the electroweak scale. A new and simple recipe to compute an analytical tree-level upper bound on the mass of this light scalar is given. We compare this new bound with similar ones existing in the literature and show how to extract extra information on heavier neutral scalars in the spectrum from the interplay of independent bounds. Production of these states at future colliders is addressed and the implications for the decoupling limit in which only one Higgs is expected to remain light are discussed. (orig.)

  6. Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing

    International Nuclear Information System (INIS)

    Chanowitz, Michael S.

    2010-01-01

    Theoretical and experimental limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on m H already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order θ Cabbibo is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of m H . We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.

  7. Mass-transport limitation to in-cloud reaction rates: Implications of new accommodation coefficient measurements

    International Nuclear Information System (INIS)

    Schwartz, S.E.

    1988-10-01

    Although it has been recognized for some time that the rate of reactive uptake of gases in cloudwater can depend on the value of the mass-accommodation coefficient (α) describing interfacial mass transport (MT), definitive evaluation of such rates is only now becoming possible with the availability of measurements of α for gases of atmospheric interest at air-water interfaces. Examination of MT limitation to the rate of in-cloud aqueous-phase oxidation of SO 2 by O 3 and H 2 O 2 shows that despite the low value of α/sub O3/ (5 /times/ 10/sup /minus/4/), interfacial MT of this species is not limiting under essentially all conditions of interest; the high values of α for SO 2 (≥ 0.2) and H 2 O 2 (≥ 0.08) indicate no interfacial MT limitation for these species also. Although gas- and aqueous-phase MT can be limiting under certain extremes of conditions, treating the system as under chemical kinetic control is generally an excellent approximation. Interfacial MT limitation also is found not to hinder the rate of H 2 O 2 formation by aqueous-phase disproportionation of HO 2 . Finally, the rapid uptake of N 2 O 5 by cloud droplets implies that the yield of aqueous HNO 3 from in-cloud gas-phase oxidation of NO 2 by O 3 can be substantial even under daytime conditions. This report consists of copies of viewgraphs prepared for this presentation

  8. Limits on runaway growth of intermediate mass black holes from advanced LIGO

    Science.gov (United States)

    Kovetz, Ely D.; Cholis, Ilias; Kamionkowski, Marc; Silk, Joseph

    2018-06-01

    There is growing evidence that intermediate-mass black holes (IMBHs), defined here as having a mass in the range M =500 -105 M⊙ , are present in the dense centers of certain globular clusters (GCs). Gravitational waves from their mergers with other IMBHs or with stellar BHs in the cluster are mostly emitted in frequencies ≲10 Hz , which unfortunately is out of reach for current ground-based observatories such as advanced LIGO (aLIGO). Nevertheless, we show that aLIGO measurements can be used to efficiently probe one of the possible formation mechanisms of IMBHs in GCs, namely a runaway merger process of stellar seed BHs. In this case, aLIGO will be sensitive to the lower-mass rungs of the merger ladder, ranging from the seed BH mass to masses ≳50 - 300 M⊙ , where the background from standard mergers is expected to be very low. Assuming this generic IMBH formation scenario, we calculate the mass functions that correspond to the limiting cases of possible merger trees. Based on estimates for the number density of GCs and taking into account the instrumental sensitivity, we show that current observations do not effectively limit the occupation fraction focc of IMBHs formed by runaway mergers of stellar BHs in GCs. However, we find that if runaway mergers occur steadily throughout the lifetimes of GCs (as opposed to happening mainly early in their lifetimes), then a six-year run of aLIGO at design sensitivity will be able to probe down to focc≲3 % at a 99.9% confidence level, either finding evidence for this formation mechanism, or necessitating others if the fraction of GCs that harbor IMBHs is higher.

  9. Heavy quark masses in the continuum limit of quenched Lattice QCD

    International Nuclear Information System (INIS)

    De Divitiis, G.M.; Guagnelli, M.; Palombi, F.; Petronzio, R.; Tantalo, N.

    2003-01-01

    We compute charm and bottom quark masses in the quenched approximation and in the continuum limit of lattice QCD. We make use of a step scaling method, previously introduced to deal with two scale problems, that allows to take the continuum limit of the lattice data. We determine the RGI quark masses and make the connection to the MS-bar scheme. The continuum extrapolation gives us a value m b RGI =6.73(16) GeV for the b-quark and m c RGI =1.681(36) GeV for the c-quark, corresponding, respectively, to m b MS-bar (m b MS-bar =4.33(10) GeV and m c MS-bar (m c MS-bar =1.319(28) GeV. The latter result, in agreement with current estimates, is for us a check of the method. Using our results on the heavy quark masses we compute the mass of the B c meson, M B c =6.46(15) GeV

  10. On the vanishing electron-mass limit in plasma hydrodynamics in unbounded media

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Feireisl, Eduard; Novotný, A.

    2012-01-01

    Roč. 22, č. 6 (2012), s. 985-1012 ISSN 0938-8974 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : vanishing electron mass limit * plasma hydrodynamics * compressible fluid Subject RIV: BA - General Mathematics Impact factor: 1.566, year: 2012 http://link.springer.com/article/10.1007%2Fs00332-012-9134-5

  11. Unitarity limits on the mass and radius of dark matter particles

    Science.gov (United States)

    Griest, Kim; Kamionkowski, Marc

    1989-01-01

    Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

  12. Limited influence of climate change mitigation on short-term glacier mass loss

    Science.gov (United States)

    Marzeion, Ben; Kaser, Georg; Maussion, Fabien; Champollion, Nicolas

    2018-04-01

    Glacier mass loss is a key contributor to sea-level change1,2, slope instability in high-mountain regions3,4 and the changing seasonality and volume of river flow5-7. Understanding the causes, mechanisms and time scales of glacier change is therefore paramount to identifying successful strategies for mitigation and adaptation. Here, we use temperature and precipitation fields from the Coupled Model Intercomparison Project Phase 5 output to force a glacier evolution model, quantifying mass responses to future climatic change. We find that contemporary glacier mass is in disequilibrium with the current climate, and 36 ± 8% mass loss is already committed in response to past greenhouse gas emissions. Consequently, mitigating future emissions will have only very limited influence on glacier mass change in the twenty-first century. No significant differences between 1.5 and 2 K warming scenarios are detectable in the sea-level contribution of glaciers accumulated within the twenty-first century. In the long-term, however, mitigation will exert strong control, suggesting that ambitious measures are necessary for the long-term preservation of glaciers.

  13. Mass current in 3He - A: Some exact representations and their London limit near zero temperature

    International Nuclear Information System (INIS)

    Malyshev, C.

    1995-09-01

    New representations for normal Green's function of the superfluid A-phase of helium-3 are obtained by an exact solution of the Dyson-Gor'kov equation. These representations result in new formulae for the mass current j-vector near zero temperature. Specific limiting cases for j-vector such ast the limit of lowest order in gradients, following the limit of zero temperature, and vice versa, are investigated. It is shown that the mass current previously known as j-vector = j-vector 0 , where j-vector 0 is an expression of first order in gradients, should be treated as a ''quasiclassical'' object in view of the approximations chosen. The parameter 1/χ implying the ''quasiclassics'', is a small quantity, as the London limit condition holds. Expansion of j-vector in powers of 1/χ is considered and first corrections to j-vector 0 are obtained at zero temperature, for two gauges of the order parameter. (author). 26 refs

  14. Isotope dilution mass spectrometry: some present limitations and possibilities to overcome these

    International Nuclear Information System (INIS)

    De Bievre, P.

    1981-01-01

    Thermionic mass spectrometry still has great potential for more precise and accurate measurements but it is going to place tremendous requirements on (1) the chemical purity of the samples we measure, (2) the temperature of both ionization and the filaments and (3) the number of molecular species being handled in ion sources which could increase to several dozen for one type of isotopic analysis. The lack of control by mass spectrometrists over the chemical preparation of the samples for isotopic analysis is an inherent limitation to further improvement of isotope dilution mass spectrometry. A limiting factor in isotope dilution is the ability to measure the ratio. At present, uranium isotopic reference materials are 0.1% and recently one was prepared at 0.05%. As these serve to calibrate isotope ratio measurements one cannot do better than these valves. There is no way in which isotope dilution can be improved until these reference values improve. For plutonium there are not even absolute isotope ratio standards. An agreement has been established between CBNM, Geel and the National Bureau of Standards, Washington, to prepare isotope ratio reference materials jointly so that they will be common to both communities. It is recommended that common batches of reference be established and stored at several places to guarantee accessibility at all times

  15. A Limit on the Warm Dark Matter Particle Mass from the Redshifted 21 cm Absorption Line

    Science.gov (United States)

    Safarzadeh, Mohammadtaher; Scannapieco, Evan; Babul, Arif

    2018-06-01

    The recent Experiment to Detect the Global Epoch of Reionization Signature (EDGES) collaboration detection of an absorption signal at a central frequency of ν = 78 ± 1 MHz points to the presence of a significant Lyα background by a redshift of z = 18. The timing of this signal constrains the dark matter particle mass (m χ ) in the warm dark matter (WDM) cosmological model. WDM delays the formation of small-scale structures, and therefore a stringent lower limit can be placed on m χ based on the presence of a sufficiently strong Lyα background due to star formation at z = 18. Our results show that coupling the spin temperature to the gas through Lyα pumping requires a minimum mass of m χ > 3 keV if atomic cooling halos dominate the star formation rate at z = 18, and m χ > 2 keV if {{{H}}}2 cooling halos also form stars efficiently at this redshift. These limits match or exceed the most stringent limits cited to date in the literature, even in the face of the many uncertainties regarding star formation at high redshift.

  16. The direct limit on the Higgs Mass and the SM Fit

    International Nuclear Information System (INIS)

    Chanowitz, Michael S.

    2003-01-01

    Because of two 3σ anomalies, the Standard Model (SM) fit of the precision electroweak data has a poor confidence level, CL = 0.02. Since both anomalies involve challenging systematic issues, it might appear that the SM could still be valid if the anomalies resulted from underestimated systematic error. Indeed the CL of the global fit could then increase to 0.71, but that fit predicts a small Higgs boson mass, m H = 45 GeV, that is inconsistent at 95% CL with the lower limit, m H > 114 GeV, established by direct searches. The data then favor new physics whether the anomalous measurements are excluded from the fit or not, and the Higgs boson mass cannot be predicted until the new physics is understood. Some measure of statistical fluctuation would be needed to maintain the validity of the SM. New physics is favored, but the SM is not definitively excluded

  17. Performance of intact and partially degraded concrete barriers in limiting mass transport

    International Nuclear Information System (INIS)

    Walton, J.C.

    1992-06-01

    Mass transport through concrete barriers and release rate from concrete vaults are quantitatively evaluated. The thorny issue of appropriate diffusion coefficients for use in performance assessment calculations is covered, with no ultimate solution found. Release from monolithic concrete vaults composed of concrete waste forms is estimated with a semi-analytical solution. A parametric study illustrates the importance of different parameters on release. A second situation of importance is the role of a concrete shell or vault placed around typical waste forms in limiting mass transport. In both situations, the primary factor controlling concrete performance is cracks. The implications of leaching behavior on likely groundwater concentrations is examined. Frequently, lower groundwater concentrations can be expected in the absence of engineered covers that reduce infiltration

  18. Mass limit for the standard model Higgs boson with the full LEP I ALEPH data sample

    Science.gov (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Nief, J.-Y.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Rensch, B.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Williams, M. I.; Galla, A.; Giehl, I.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Choi, Y.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, A. M.; Lan Wu, Sau; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1996-02-01

    The reaction e +e - → HZ ∗ is used to search for the standard model Higgs boson in the Hν overlineν and the Hℓ +ℓ - channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the H μ+μ- channel, in agreement with the expected background from the electroweak process e +e -ℓ +ℓ -q overlineq. This search results in a 95% C.L. lower limit on the Higgs boson mass of 63.9 GeV/ c2.

  19. First Dark Matter Limits from a Large-Mass, Low-Background Superheated Droplet Detector

    CERN Document Server

    Collar, J.I.; Girard, T.A.; Limagne, D.; Miley, H.S.; Waysand, G.

    2000-01-01

    We report on the fabrication aspects and calibration of the first large active mass ($\\sim15$ g) modules of SIMPLE, a search for particle dark matter using Superheated Droplet Detectors (SDDs). While still limited by the statistical uncertainty of the small data sample on hand, the first weeks of operation in the new underground laboratory of Rustrel-Pays d'Apt already provide a sensitivity to axially-coupled Weakly Interacting Massive Particles (WIMPs) competitive with leading experiments, confirming SDDs as a convenient, low-cost alternative for WIMP detection.

  20. Determination of the upper mass limit for stars producing white-dwarf remnants

    International Nuclear Information System (INIS)

    Romanishin, W.; Angel, J.R.P.

    1980-01-01

    We have searched ultraviolet and red plates of four open clusters (NGC 2168, 2287, 2422, and 6633) for faint blue objects which might be white dwarf members of the clusters. The most massive stars in these clusters range from 3 to 6 M/sub sun/. We find a definite concentration of faint blue objects in the clusters. This fact, plus initial photoelectric photometry, provides strong support for the identification of many of these objects as cluster white dwarfs. By modeling the expected number of possible white dwarfs in each cluster, we are able to put some limits on m/sub w/, the upper stellar mass limit for formation of white dwarfs. Our data require that some stars of at least 5 M/sub sun/ have evolved into white dwarfs and give a most probable value of 7 M/sub sun/ for m/sub w/

  1. Continuum limit of overlap valence quarks on a twisted mass sea

    International Nuclear Information System (INIS)

    Cichy, Krzysztof; Herdoiza, Gregorio; Univ. Autonoma de Madrid; Jansen, Karl

    2010-12-01

    We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using three values of the lattice spacing ranging from a∼0.05 fm to 0.08 fm. A particular emphasis is put on the effect on physical observables of the topological zero modes appearing in the valence overlap operator. We estimate the region of parameter space where the contribution from these zero modes is sufficiently small such that their effects can be safely controlled and a restoration of unitarity of the mixed action in the continuum limit is reached. (orig.)

  2. Thermal ionization mass spectrometry (TIMS) of actinides: Pushing the limits of accuracy and detection

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, Stefan; Boulyga, Sergei; Cunningham, Alan; Klose, Dilani; Koepf, Andreas; Poths, Jane [Safeguards Analytical Laboratory, International Atomic Energy Agency, Vienna (Austria); Richter, Stephan [Institute for Reference Materials and Measurements, JRC-EU, Geel (Belgium)

    2010-07-01

    New method developments in multi-collector thermal ionization mass spectrometry (MC-TIMS) for actinide isotope ratio analysis to improve accuracy and limits of detection will be presented. With respect to limits of detection, results on improving work function using various carbon additives will be reviewed and presented as well as developments in cavity ion source (as compared to standard flat ribbon filament ion source) for femto- and attogram levels of uranium, plutonium, and americium. With respect to accuracy, results on isotope ratio measurements of isotopes of uranium (relative accuracy of 0.3% to 0.01%) are presented with an example being U-234-Th-230 age-dating (NBL CRM 112-A). In this context, the importance of traceability (to the S.I. units) and the use of (certified) reference materials are emphasized. The focus of this presentation is on applications to nuclear safeguards / forensics.

  3. Continuum limit of overlap valence quarks on a twisted mass sea

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, Krzysztof [Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Herdoiza, Gregorio [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC; Univ. Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Jansen, Karl [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

    2010-12-15

    We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using three values of the lattice spacing ranging from a{approx}0.05 fm to 0.08 fm. A particular emphasis is put on the effect on physical observables of the topological zero modes appearing in the valence overlap operator. We estimate the region of parameter space where the contribution from these zero modes is sufficiently small such that their effects can be safely controlled and a restoration of unitarity of the mixed action in the continuum limit is reached. (orig.)

  4. The subcritical mass limit, 2.4 kgU, for the JCO's precipitation tank

    International Nuclear Information System (INIS)

    Komuro, Yuichi

    1999-01-01

    The critical safety on the precipitation tank in JCO Corporation forming a critical accident in September 30, 1999 had to be guaranteed by limiting amount of uranium contained into charging solution. The limited value of uranic mass in the precipitation tank was determined to be 2.4 kg, and from the dissolution tank positioned at upstream of this tank a solution not excess amount of solution to this value was designed to be transferred. In the 2nd Accident Survey Committee, there were found some discussions on a leading method of this value. In order to answer some requirements for this, here was described on outlines on U.S. Nuclear Safety Guide, TID-7016 Rev. 1, leading method of the limited value in 2.4 kg, and safety tolerance. As a result of reinvestigation, as it was confirmed that 2.4 kg in the limited amount contained an sufficient safety tolerance qualitatively and in comparison with already critical data. (G.K.)

  5. Limits on the Masses of Supersymmetric Particles at $\\sqrt{s}$=189 GeV

    CERN Document Server

    Abreu, P.; Adye, T.; Adzic, P.; Azhinenko, I.; Albrecht, Z.; Alderweireld, T.; Alekseev, G.D.; Alemany, R.; Allmendinger, T.; Allport, P.P.; Almehed, S.; Amaldi, U.; Amapane, N.; Amato, S.; Anassontzis, E.G.; Andersson, P.; Andreazza, A.; Andringa, S.; Antilogus, P.; Apel, W.D.; Arnoud, Y.; Asman, B.; Augustin, J.E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barao, F.; Barbiellini, G.; Barbier, R.; Bardin, D.Yu.; Barker, G.J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.H.; Begalli, M.; Behrmann, A.; Beilliere, P.; Belokopytov, Yu.; Benekos, N.C.; Benvenuti, A.C.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Bilenky, Mikhail S.; Bizouard, M.A.; Bloch, D.; Blom, H.M.; Bonesini, M.; Boonekamp, M.; Booth, P.S.L.; Borisov, G.; Bosio, C.; Botner, O.; Boudinov, E.; Bouquet, B.; Bourdarios, C.; Bowcock, T.J.V.; Boyko, I.; Bozovic, I.; Bozzo, M.; Bracko, M.; Branchini, P.; Brenner, R.A.; Bruckman, P.; Brunet, J.M.; Bugge, L.; Buran, T.; Buschbeck, B.; Buschmann, P.; Cabrera, S.; Caccia, M.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Carroll, L.; Caso, C.; Castillo Gimenez, M.V.; Cattai, A.; Cavallo, F.R.; Charpentier, P.; Checchia, P.; Chelkov, G.A.; Chierici, R.; Shlyapnikov, P.; Chochula, P.; Chorowicz, V.; Chudoba, J.; Cieslik, K.; Collins, P.; Contri, R.; Cortina, E.; Cosme, G.; Cossutti, F.; Costa, M.; Crawley, H.B.; Crennell, D.; Crosetti, G.; Cuevas Maestro, J.; Czellar, S.; D'Hondt, J.; Dalmau, J.; Davenport, M.; Da Silva, W.; Della Ricca, G.; Delpierre, P.; Demaria, N.; De Angelis, A.; De Boer, W.; De Clercq, C.; De Lotto, B.; De Min, A.; De Paula, L.; Dijkstra, H.; Di Ciaccio, L.; Dolbeau, J.; Doroba, K.; Dracos, M.; Drees, J.; Dris, M.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Engel, J.P.; Espirito Santo, M.C.; Fanourakis, G.K.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferrer-Ribas, E.; Ferro, F.; Firestone, A.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fontanelli, F.; Franek, B.; Frodesen, A.G.; Fruhwirth, R.; Fulda-Quenzer, F.; Fuster, J.; Galloni, A.; Gamba, D.; Gamblin, S.; Gandelman, M.; Garcia, C.; Gaspar, C.; Gaspar, M.; Gasparini, U.; Gavillet, P.; Gazis, Evangelos; Gele, D.; Geralis, T.; Gerdyukov, L.; Ghodbane, N.; Gil Botella, Ines; Glege, F.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Gonzalez Caballero, I.; Gopal, G.; Gorn, L.; Gouz, Yu.; Gracco, V.; Grahl, J.; Graziani, E.; Gris, P.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hahn, F.; Hahn, S.; Haider, S.; Hallgren, A.; Hamacher, K.; Hansen, J.; Harris, F.J.; Hauler, F.; Hedberg, V.; Heising, S.; Hernandez, J.J.; Herquet, P.; Herr, H.; Higon, E.; Holmgren, S.O.; Holt, P.J.; Hoorelbeke, S.; Houlden, M.; Hrubec, J.; Huber, M.; Hughes, G.J.; Hultqvist, K.; Jackson, John Neil; Jacobsson, R.; Jalocha, P.; Janik, R.; Jarlskog, C.; Jarlskog, G.; Jarry, P.; Jean-Marie, B.; Jeans, D.; Johansson, Erik Karl; Jonsson, P.; Joram, C.; Juillot, P.; Jungermann, L.; Kapusta, Frederic; Karafasoulis, K.; Katsanevas, S.; Katsoufis, E.C.; Keranen, R.; Kernel, G.; Kersevan, B.P.; Khokhlov, Yu.A.; Khomenko, B.A.; Khovansky, N.N.; Kiiskinen, A.; King, B.J.; Kinvig, A.; Kjaer, N.J.; Klapp, O.; Kluit, P.; Kokkinias, P.; Kostyukhin, V.; Kourkoumelis, C.; Kuznetsov, O.; Krammer, M.; Kriznic, E.; Krumshtein, Z.; Kubinec, P.; Kurowska, J.; Kurvinen, K.; Lamsa, J.W.; Lane, D.W.; Laugier, J.P.; Lauhakangas, R.; Leder, G.; Ledroit, Fabienne; Leinonen, L.; Leisos, A.; Leitner, R.; Lenzen, G.; Lepeltier, V.; Lesiak, T.; Lethuillier, M.; Libby, J.; Liebig, W.; Liko, D.; Lipniacka, A.; Lippi, I.; Lorstad, B.; Loken, J.G.; Lopes, J.H.; Lopez, J.M.; Lopez-Fernandez, R.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Mahon, J.R.; Maio, A.; Malek, A.; Maltezos, S.; Malychev, V.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Marti i Garcia, S.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Matthiae, G.; Mazzucato, F.; Mazzucato, M.; McCubbin, M.; McKay, R.; McNulty, R.; McPherson, G.; Merle, E.; Meroni, C.; Meyer, W.T.; Migliore, E.; Mirabito, L.; Mitaroff, W.A.; Mjornmark, U.; Moa, T.; Moch, M.; Moller, Rasmus; Monig, Klaus; Monge, M.R.; Moraes, D.; Morettini, P.; Morton, G.; Muller, U.; Munich, K.; Mulders, M.; Mulet-Marquis, C.; Mundim, L.M.; Muresan, R.; Murray, W.J.; Muryn, B.; Myatt, G.; Myklebust, T.; Naraghi, F.; Nassiakou, M.; Navarria, F.L.; Nawrocki, K.; Negri, P.; Neufeld, N.; Nicolaidou, R.; Nielsen, B.S.; Niezurawski, P.; Nikolenko, M.; Nomokonov, V.; Nygren, A.; Obraztsov, V.F.; Olshevsky, A.G.; Onofre, A.; Orava, R.; Orazi, G.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Pain, R.; Paiva, R.; Palacios, J.; Palka, H.; Papadopoulou, T.D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Pavel, T.; Pegoraro, M.; Peralta, L.; Pernicka, M.; Perrotta, A.; Petridou, C.; Petrolini, A.; Phillips, H.T.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M.E.; Polok, G.; Poropat, P.; Pozdnyakov, V.; Privitera, P.; Pukhaeva, N.; Pullia, A.; Radojicic, D.; Ragazzi, S.; Rahmani, H.; Rames, J.; Ratoff, P.N.; Read, Alexander L.; Rebecchi, P.; Redaelli, Nicola Giuseppe; Regler, M.; Rehn, J.; Reid, D.; Reinertsen, P.; Reinhardt, R.; Renton, P.B.; Resvanis, L.K.; Richard, F.; Ridky, J.; Rinaudo, G.; Ripp-Baudot, Isabelle; Romero, A.; Ronchese, P.; Rosenberg, E.I.; Rosinsky, P.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ruiz, A.; Saarikko, H.; Sacquin, Y.; Sadovsky, A.; Sajot, G.; Salt, J.; Sampsonidis, D.; Sannino, M.; Savoy-Navarro, A.; Schwemling, P.; Schwering, B.; Schwickerath, U.; Scuri, Fabrizio; Seager, P.; Sedykh, Yu.; Segar, A.M.; Seibert, N.; Sekulin, R.; Sette, G.; Shellard, R.C.; Siebel, M.; Simard, L.; Simonetto, F.; Sisakian, A.N.; Smadja, G.; Smirnov, N.; Smirnova, O.; Smith, G.R.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassoff, T.; Spiriti, E.; Squarcia, S.; Stanescu, C.; Stanitzki, M.; Stevenson, K.; Stocchi, A.; Strauss, J.; Strub, R.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Tabarelli, T.; Taffard, A.; Chikilev, O.; Tegenfeldt, F.; Terranova, F.; Timmermans, Jan; Tinti, N.; Tkachev, L.G.; Tobin, M.; Todorova, S.; Tome, B.; Tonazzo, A.; Tortora, L.; Tortosa, P.; Transtromer, G.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.L.; Tyapkin, I.A.; Tyapkin, P.; Tzamarias, S.; Ullaland, O.; Uvarov, V.; Valenti, G.; Vallazza, E.; Vander Velde, C.; Van Dam, Piet; Van Den Boeck, W.; Van Eldik, J.; Van Lysebetten, A.; Van Remortel, N.; Van Vulpen, I.; Vegni, G.; Ventura, L.; Venus, W.; Verbeure, F.; Verdier, P.; Verlato, M.; Vertogradov, L.S.; Verzi, V.; Vilanova, D.; Vitale, L.; Vlasov, E.; Vodopianov, A.S.; Voulgaris, G.; Vrba, V.; Wahlen, H.; Washbrook, A.J.; Weiser, C.; Wicke, D.; Wickens, J.H.; Wilkinson, G.R.; Winter, M.; Witek, M.; Wolf, G.; Yi, J.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zevgolatakos, E.; Zimine, N.I.; Zinchenko, A.; Zoller, P.; Zumerle, G.; Zupan, M.

    2000-01-01

    Searches for charginos, neutralinos and sleptons at LEP2 centre-of-mass energies from 130 GeV to 189 GeV have been used to set lower limits on the mass of the Lightest Supersymmetric Particle and other supersymmetric particles within the MSSM framework. R-parity conservation has been assumed. The lightest neutralino was found to be heavier than 32.3~\\mbox{$ {\\mathrm{GeV}}/c^2$} independent of the $m_0$ value. The lightest chargino, the second-to-lightest neutralino, the next-to-heaviest neutralino, the heaviest neutralino, the sneutrino and the right-handed selectron %{\\mbox{$ {\\tilde{\\mathrm e}_R} $}} were found to be heavier than 62.4~\\mbox{$ {\\mathrm{GeV}}/c^2$}, 62.4~\\mbox{$ {\\mathrm{GeV}}/c^2$}, 99.9~\\mbox{$ {\\mathrm{GeV}}/c^2$}, 116.0~\\mbox{$ {\\mathrm{GeV}}/c^2$}, 61.0~\\mbox{$ {\\mathrm{GeV}}/c^2$}, and 87.0 GeV=c$^{2}$ , respectively. These limits do not depend on m0 or M2 and are valid for 1 $\\le tan\\beta \\le 40$, in the $\\mu$ region where the lightest neutralino is the LSP. If the sneutrino is heavier...

  6. Dynamics of laser mass-limited foil interaction at ultra-high laser intensities

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T. P., E-mail: tongpu@nudt.edu.cn [College of Science, National University of Defense Technology, Changsha 410073 (China); State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073 (China); Sheng, Z. M. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, Y.; Zhuo, H. B.; Ma, Y. Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Pukhov, A. [Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf (Germany)

    2014-05-15

    By using three-dimensional particle-in-cell simulations with synchrotron radiation damping incorporated, dynamics of ultra-intense laser driven mass-limited foils is presented. When a circularly polarized laser pulse with a peak intensity of ∼10{sup 22} W/cm{sup 2} irradiates a mass-limited nanofoil, electrons are pushed forward collectively and a strong charge separation field forms which acts as a “light sail” and accelerates the protons. When the laser wing parts overtake the foil from the foil boundaries, electrons do a betatron-like oscillation around the center proton bunch. Under some conditions, betatron-like resonance takes place, resulting in energetic circulating electrons. Finally, bright femto-second x rays are emitted in a small cone. It is also shown that the radiation damping does not alter the foil dynamics radically at considered laser intensities. The effects of the transverse foil size and laser polarization on x-ray emission and foil dynamics are also discussed.

  7. Improved detection limit for {sup 59}Ni using the technique of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Per; Erlandsson, Bengt; Hellborg, Ragnar; Kiisk, Madis; Larsson, Ragnar; Skog, Goeran; Stenstroem, Kristina [Lund Univ. (Sweden). Dept. of Nuclear Physics

    2002-11-01

    59 Ni is produced by neutron activation in the stainless steel close to the core of a nuclear reactor. To be able to classify the different parts of the reactor with respect to their content of long-lived radionuclides before final storage it is important to measure the 59 Ni level. Accelerator mass spectrometry is an ultra-sensitive method for counting atoms, suitable for 59 Ni measurements. Improvements in the reduction of the background and in the chemical reduction of cobalt, the interfering isobar, have been made. This chemical purification is essential when using small tandem accelerators, <3 MV, combined with the detection of characteristic projectile X-rays. These improvements have lowered the detection limit for 59 Ni by a factor of twenty compared with the first value reported for the Lund AMS facility. Material from the Swedish nuclear industry has been analysed and examples of the results are presented.

  8. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  9. Mass fractionation of noble gases in diffusion-limited hydrodynamic hydrogen escape

    International Nuclear Information System (INIS)

    Zahnle, K.; Pollack, J.B.; Kasting, J.F.

    1990-01-01

    The theory of mass fractionation by hydrogen is presently extended to atmospheres in which hydrogen is not the major constituent. This theoretical framework is applied to three different cases. In the first, it is shown that the fractionation of terrestrial atmospheric neon with respect to mantle neon is explainable as a consequence of diffusion-limited hydrogen escape from a steam atmosphere toward the end of the accretion process. In the second, the anomalously high Ar-38/Ar-36 ratio of Mars is shown to be due to hydrodynamic fractionation by a vigorously escaping and very pure hydrogen wind. In the last case, it is speculated that the currently high Martian D/H ratio emerged during the hydrodynamic escape phase which fractionated Ar. 35 refs

  10. Limit behavior of mass critical Hartree minimization problems with steep potential wells

    Science.gov (United States)

    Guo, Yujin; Luo, Yong; Wang, Zhi-Qiang

    2018-06-01

    We consider minimizers of the following mass critical Hartree minimization problem: eλ(N ) ≔inf {u ∈H1(Rd ) , ‖u‖2 2=N } Eλ(u ) , where d ≥ 3, λ > 0, and the Hartree energy functional Eλ(u) is defined by Eλ(u ) ≔∫Rd|∇u (x ) |2d x +λ ∫Rdg (x ) u2(x ) d x -1/2 ∫Rd∫Rdu/2(x ) u2(y ) |x -y |2 d x d y . Here the steep potential g(x) satisfies 0 =g (0 ) =infRdg (x ) ≤g (x ) ≤1 and 1 -g (x ) ∈Ld/2(Rd ) . We prove that there exists a constant N* > 0, independent of λg(x), such that if N ≥ N*, then eλ(N) does not admit minimizers for any λ > 0; if 0 N N*, then there exists a constant λ*(N) > 0 such that eλ(N) admits minimizers for any λ > λ*(N) and eλ(N) does not admit minimizers for 0 N). For any given 0 N N*, the limit behavior of positive minimizers for eλ(N) is also studied as λ → ∞, where the mass concentrates at the bottom of g(x).

  11. Breeding limits foraging time : Evidence of interrupted foraging response from body mass variation in a tropical environment

    NARCIS (Netherlands)

    Nwaogu, Chima J.; Dietz, Maurine W.; Tieleman, B. Irene; Cresswell, Will

    Birds should store body reserves if starvation risk is anticipated; this is known as an ‘interrupted foraging response’. If foraging remains unrestricted, however, body mass should remain low to limit the predation risk that gaining and carrying body reserves entails. In temperate environments mass

  12. Strategies to reduce mass and photons transfer limitations in heterogeneous photocatalytic processes: Hexavalent chromium reduction studies.

    Science.gov (United States)

    Marinho, Belisa A; Cristóvão, Raquel O; Djellabi, Ridha; Caseiro, Ana; Miranda, Sandra M; Loureiro, José M; Boaventura, Rui A R; Dias, Madalena M; Lopes, José Carlos B; Vilar, Vítor J P

    2018-07-01

    The current work presents different approaches to overcome mass and photon transfer limitations in heterogeneous photocatalytic processes applied to the reduction of hexavalent chromium to its trivalent form in the presence of a sacrificial agent. Two reactor designs were tested, a monolithic tubular photoreactor (MTP) and a micro-meso-structured photoreactor (NETmix), both presenting a high catalyst surface area per reaction liquid volume. In order to reduce photon transfer limitations, the tubular photoreactor was packed with transparent cellulose acetate monolithic structures (CAM) coated with the catalyst by a dip-coating method. For the NETmix reactor, a thin film of photocatalyst was uniformly deposited on the front glass slab (GS) or on the network of channels and chambers imprinted in the back stainless steel slab (SSS) using a spray system. The reaction rate for the NETmix photoreactor was evaluated for two illumination sources, solar light or UVA-LEDs, using the NETmix with the front glass slab or/and back stainless steel slab coated with TiO 2 -P25. The reusability of the photocatalytic films on the NETmix walls was also evaluated for three consecutive cycles using fresh Cr(VI) solutions. The catalyst reactivity in combination with the NETmix-SSS photoreactor is almost 70 times superior to one obtained with the MTP. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Patient-specific lean body mass can be estimated from limited-coverage computed tomography images.

    Science.gov (United States)

    Devriese, Joke; Beels, Laurence; Maes, Alex; van de Wiele, Christophe; Pottel, Hans

    2018-06-01

    In PET/CT, quantitative evaluation of tumour metabolic activity is possible through standardized uptake values, usually normalized for body weight (BW) or lean body mass (LBM). Patient-specific LBM can be estimated from whole-body (WB) CT images. As most clinical indications only warrant PET/CT examinations covering head to midthigh, the aim of this study was to develop a simple and reliable method to estimate LBM from limited-coverage (LC) CT images and test its validity. Head-to-toe PET/CT examinations were retrospectively retrieved and semiautomatically segmented into tissue types based on thresholding of CT Hounsfield units. LC was obtained by omitting image slices. Image segmentation was validated on the WB CT examinations by comparing CT-estimated BW with actual BW, and LBM estimated from LC images were compared with LBM estimated from WB images. A direct method and an indirect method were developed and validated on an independent data set. Comparing LBM estimated from LC examinations with estimates from WB examinations (LBMWB) showed a significant but limited bias of 1.2 kg (direct method) and nonsignificant bias of 0.05 kg (indirect method). This study demonstrates that LBM can be estimated from LC CT images with no significant difference from LBMWB.

  14. 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.

  15. Active structural control of a floating wind turbine with a stroke-limited hybrid mass damper

    Science.gov (United States)

    Hu, Yaqi; He, Erming

    2017-12-01

    Floating wind turbines are subjected to more severe structural loads than fixed-bottom wind turbines due to additional degrees of freedom (DOFs) of their floating foundations. It's a promising way of using active structural control method to improve the structural responses of floating wind turbines. This paper investigates an active vibration control strategy for a barge-type floating wind turbine by setting a stroke-limited hybrid mass damper (HMD) in the turbine's nacelle. Firstly, a contact nonlinear modeling method for the floating wind turbine with clearance between the HMD and the stroke limiters is presented based on Euler-Lagrange's equations and an active control model of the whole system is established. The structural parameters are validated for the active control model and an equivalent load coefficient method is presented for identifying the wind and wave disturbances. Then, a state-feedback linear quadratic regulator (LQR) controller is designed to reduce vibration and loads of the wind turbine, and two optimization methods are combined to optimize the weighting coefficients when considering the stroke of the HMD and the active control power consumption as constraints. Finally, the designed controllers are implemented in high fidelity simulations under five typical wind and wave conditions. The results show that active HMD control strategy is shown to be achievable and the designed controllers could further reduce more vibration and loads of the wind turbine under the constraints of stroke limitation and power consumption. "V"-shaped distribution of the TMD suppression effect is inconsistent with the Weibull distribution in practical offshore floating wind farms, and the active HMD control could overcome this shortcoming of the passive TMD.

  16. Upper limit of the muon-neutrino mass and charged-pion mass from the momentum analysis of a surface muon beam

    Energy Technology Data Exchange (ETDEWEB)

    Kettle, P R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    Using a surface muon beam and a magnetic spectrometer equipped with a position-sensitive detector, we have measured the muon momentum from pion decay at rest {pi}{sup +}{yields}{mu}{sup +}{nu}{sub {mu}}, to be p{sub {mu}{sup +}}=(29.79200{+-}0.00011)MeV/c. This value together with the muon mass and the favoured pion mass leads to an upper limit of 0.17 MeV (90%CL) for the muon-neutrino mass. (author) 4 figs., 5 refs.

  17. Usefulness limitation of 3D-ultrasound diagnosis of breast masses

    International Nuclear Information System (INIS)

    Cheon, Yong Seok; Chung, Soo Young; Yang, Ik; Lee, Kyung Won; Kim, Hong Dae; Shin, Sang Joon; Chung, Bong Wha

    2001-01-01

    To compare 3D ultrasound (3D-US) with 2D ultrasound (2D-US) in terms of their usefulness and limitations in the diagnosis of breast masses. We obtained 2D and 3D US images of 37 breast lesions present in 20 cases of fibroadenoma, nine of cancer, and eight of fibrocystic disease proven in a total of 26 cases [ fibroadenoma (n=13), breast cancer (n=9), fibrocystic disease (n=4)] by histologic examination, and by clinical evaluation and clinical evaluation with sonographic imaging in eleven. When comparing 3D and 2D-US images we had no prior information regarding detection rate according to the size of lesions, whether or not internal and boundary echo patterns could be interpreted, accurate differentiation between tumorous and non-tumorous lesions, or the accuracy with which benign and malignant tumors could be differentiated. For lesions of 1 cm or less in diameter the detection rate of 3D-US was lower than that of 2D-US, but for lesions over 1 cm there was no difference between the two modalities. In fibroadenoma and breast cancer, 3D-US was more useful than 2D-US for the evaluation of both internal and boundary echo, but with fibrocystic disease and in the diagnosis of tumor/non-tumor, there was no significant difference. In breast cancer, however, 3D-US more accurately determined malignancy, and in fibroadenoma, because of the pseudospicule revealed by 3D-US, this modality was less exact in determining benignancy. In the evaluation of internal and boundary echo in breast mass diagnosis, 3D-US was more useful than its 2D counterpart. For lesions of 1 cm or less in diameter, however, the detection rate of 3D-US was more useful than its 2D counterpart. For lesions of 1 cm or less in diameter, however, the detection rate of 3D-US was low, and since in some benign cases a pseudospicule was apparent, the possibility of confusion with malignancy arose. For these reasons, the usefulness of 3D-US was limited

  18. Usefulness limitation of 3D-ultrasound diagnosis of breast masses

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Yong Seok; Chung, Soo Young; Yang, Ik; Lee, Kyung Won; Kim, Hong Dae; Shin, Sang Joon; Chung, Bong Wha [College of Medicine, Hallym Univ., Seoul (Korea, Republic of)

    2001-09-01

    To compare 3D ultrasound (3D-US) with 2D ultrasound (2D-US) in terms of their usefulness and limitations in the diagnosis of breast masses. We obtained 2D and 3D US images of 37 breast lesions present in 20 cases of fibroadenoma, nine of cancer, and eight of fibrocystic disease proven in a total of 26 cases [ fibroadenoma (n=13), breast cancer (n=9), fibrocystic disease (n=4)] by histologic examination, and by clinical evaluation and clinical evaluation with sonographic imaging in eleven. When comparing 3D and 2D-US images we had no prior information regarding detection rate according to the size of lesions, whether or not internal and boundary echo patterns could be interpreted, accurate differentiation between tumorous and non-tumorous lesions, or the accuracy with which benign and malignant tumors could be differentiated. For lesions of 1 cm or less in diameter the detection rate of 3D-US was lower than that of 2D-US, but for lesions over 1 cm there was no difference between the two modalities. In fibroadenoma and breast cancer, 3D-US was more useful than 2D-US for the evaluation of both internal and boundary echo, but with fibrocystic disease and in the diagnosis of tumor/non-tumor, there was no significant difference. In breast cancer, however, 3D-US more accurately determined malignancy, and in fibroadenoma, because of the pseudospicule revealed by 3D-US, this modality was less exact in determining benignancy. In the evaluation of internal and boundary echo in breast mass diagnosis, 3D-US was more useful than its 2D counterpart. For lesions of 1 cm or less in diameter, however, the detection rate of 3D-US was more useful than its 2D counterpart. For lesions of 1 cm or less in diameter, however, the detection rate of 3D-US was low, and since in some benign cases a pseudospicule was apparent, the possibility of confusion with malignancy arose. For these reasons, the usefulness of 3D-US was limited.

  19. New high (> or =6M/sub sun/) upper mass limit for planetary nebula formation, and a new high lower mass bound for carbon detonation supernova models

    International Nuclear Information System (INIS)

    Tuchman, Y.; Sack, N.; Barkat, Z.

    1978-01-01

    Envelope ejection leading to a planetary nebula has been recently shown to occur as the terminal point of the Mira stage. The ejection is due to a diverging pulsational instability, not to a dynamical one. It is found that in this case (and for Population I, mixing length=1 pressure scale height) the upper mass limit for formation of planetary nebulae is at least 6 M/sub sun/. It thus follows that the lower mass limit for realization of carbon detonation model configurations is also at last 6 M/sub sun/

  20. Ages of young star clusters, massive blue stragglers, and the upper mass limit of stars: Analyzing age-dependent stellar mass functions

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, F. R. N.; Izzard, R. G.; Langer, N.; Stolte, A.; Hußmann, B. [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); De Mink, S. E. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); De Koter, A.; Sana, H. [Astronomical Institute " Anton Pannekoek" , Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands); Gvaramadze, V. V. [Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetskij Pr. 13, Moscow 119992 (Russian Federation); Liermann, A., E-mail: fschneid@astro.uni-bonn.de [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)

    2014-01-10

    Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M {sub ☉} limit and observations of four stars with initial masses of 165-320 M {sub ☉} in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M {sub ☉} star. Using the stellar population of R136, we revise the upper mass limit to values in the range

  1. Ages of young star clusters, massive blue stragglers, and the upper mass limit of stars: Analyzing age-dependent stellar mass functions

    International Nuclear Information System (INIS)

    Schneider, F. R. N.; Izzard, R. G.; Langer, N.; Stolte, A.; Hußmann, B.; De Mink, S. E.; Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" data-affiliation=" (Astronomical Institute Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" >De Koter, A.; Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" data-affiliation=" (Astronomical Institute Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" >Sana, H.; Gvaramadze, V. V.; Liermann, A.

    2014-01-01

    Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M ☉ limit and observations of four stars with initial masses of 165-320 M ☉ in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M ☉ star. Using the stellar population of R136, we revise the upper mass limit to values in the range 200-500 M ☉ .

  2. Ages of Young Star Clusters, Massive Blue Stragglers, and the Upper Mass Limit of Stars: Analyzing Age-dependent Stellar Mass Functions

    Science.gov (United States)

    Schneider, F. R. N.; Izzard, R. G.; de Mink, S. E.; Langer, N.; Stolte, A.; de Koter, A.; Gvaramadze, V. V.; Hußmann, B.; Liermann, A.; Sana, H.

    2014-01-01

    Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M ⊙ limit and observations of four stars with initial masses of 165-320 M ⊙ in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M ⊙ star. Using the stellar population of R136, we revise the upper mass limit to values in the range 200-500 M ⊙.

  3. Plot showing ATLAS limits on Standard Model Higgs production in the mass range 100-600 GeV

    CERN Multimedia

    ATLAS Collaboration

    2011-01-01

    The combined upper limit on the Standard Model Higgs boson production cross section divided by the Standard Model expectation as a function of mH is indicated by the solid line. This is a 95% CL limit using the CLs method in the entire mass range. The dotted line shows the median expected limit in the absence of a signal and the green and yellow bands reflect the corresponding 68% and 95% expected

  4. Plot showing ATLAS limits on Standard Model Higgs production in the mass range 110-150 GeV

    CERN Multimedia

    ATLAS Collaboration

    2011-01-01

    The combined upper limit on the Standard Model Higgs boson production cross section divided by the Standard Model expectation as a function of mH is indicated by the solid line. This is a 95% CL limit using the CLs method in in the low mass range. The dotted line shows the median expected limit in the absence of a signal and the green and yellow bands reflect the corresponding 68% and 95% expected

  5. Light stop mass limits from Higgs rate measurements in the MSSM: is MSSM electroweak baryogenesis still alive after all?

    Energy Technology Data Exchange (ETDEWEB)

    Liebler, Stefan [Deutsches Elektronen-Synchrotron (DESY),Notkestraße 85, 22607 Hamburg (Germany); Profumo, Stefano; Stefaniak, Tim [Department of Physics and Santa Cruz Institute for Particle Physics (SCIPP),University of California Santa Cruz, CA 95064 (United States)

    2016-04-22

    We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the second, heavy stop and the gluino to the multi-TeV range in order to obtain a Higgs mass of ∼125 GeV. We derive lower mass limits for the light stop within various scenarios, taking into account the effects of a possibly light scalar tau partner (stau) or chargino on the Higgs rates, of additional Higgs decays to undetectable “new physics”, as well as of non-decoupling of the heavy Higgs sector. Under conservative assumptions, the stop can be as light as 123 GeV. Relaxing certain theoretical and experimental constraints, such as vacuum stability and model-dependent bounds on sparticle masses from LEP, we find that the light stop mass can be as light as 116 GeV. Our indirect limits are complementary to direct limits on the light stop mass from collider searches and have important implications for electroweak baryogenesis in the MSSM as a possible explanation for the observed matter-antimatter asymmetry of the Universe.

  6. Light stop mass limits from Higgs rate measurements in the MSSM. Is MSSM electroweak baryogenesis still alive after all?

    Energy Technology Data Exchange (ETDEWEB)

    Liebler, Stefan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Profumo, Stefano; Stefaniak, Tim [California Univ., Santa Cruz, CA (United States). Dept. of Physics; California Univ., Santa Cruz, CA (United States). Santa Cruz Inst. for Particle Physics (SCIPP)

    2015-12-15

    We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the second, heavy stop and the gluino to the multi-TeV range in order to obtain a Higgs mass of ∝125 GeV. We derive lower mass limits for the light stop within various scenarios, taking into account the effects of a possibly light scalar tau partner (stau) or chargino on the Higgs rates, of additional Higgs decays to undetectable new physics, as well as of non-decoupling of the heavy Higgs sector. Under conservative assumptions, the stop can be as light as 123 GeV. Relaxing certain theoretical and experimental constraints, such as vacuum stability and model-dependent bounds on sparticle masses from LEP, we find that the light stop mass can be as light as 116 GeV. Our indirect limits are complementary to direct limits on the light stop mass from collider searches and have important implications for electroweak baryogenesis in the MSSM as a possible explanation for the observed matter-antimatter asymmetry of the Universe.

  7. Improved limit on the mass of ν/sub e/ from the beta decay of molecular tritium

    International Nuclear Information System (INIS)

    Bowles, T.J.; Friar, J.L.; Robertson, R.G.H.; Stephenson, G.J. Jr.; Wark, D.L.; Wilkerson, J.F.; Knapp, D.A.

    1989-01-01

    We report a new upper limit of 13.4 eV (95% confidence level) on the mass of the electron antineutrino from a study of the shape of the beta spectrum of free molecular tritium. This result appears to be inconsistent with a reported value for the mass of 26(5) eV. The electron neutrino is evidently not massive enough to close the universe by itself. 23 refs., 1 fig., 2 tabs

  8. Improved limit on the mass of bar νe from the beta decay of molecular tritium

    International Nuclear Information System (INIS)

    Bowles, T.J.; Robertson, R.G.H.; Wark, D.L.; Wilkerson, J.F.; Stephenson, G.J.; Friar, J.L.; Knapp, D.A.

    1990-01-01

    We report a new upper limit of 13.4 eV (95% confidence level) on the mass of the electron antineutrino from a study of the shape of the beta spectrum of free molecular tritium. This result appears to be inconsistent with a reported value for the mass of 26(5) eV. The electron neutrino is evidently not massive enough to close the universe by itself. 21 refs., 1 fig., 2 tabs

  9. Determination of the mass transfer limiting step of dye adsorption onto commercial adsorbent by using mathematical models.

    Science.gov (United States)

    Marin, Pricila; Borba, Carlos Eduardo; Módenes, Aparecido Nivaldo; Espinoza-Quiñones, Fernando R; de Oliveira, Silvia Priscila Dias; Kroumov, Alexander Dimitrov

    2014-01-01

    Reactive blue 5G dye removal in a fixed-bed column packed with Dowex Optipore SD-2 adsorbent was modelled. Three mathematical models were tested in order to determine the limiting step of the mass transfer of the dye adsorption process onto the adsorbent. The mass transfer resistance was considered to be a criterion for the determination of the difference between models. The models contained information about the external, internal, or surface adsorption limiting step. In the model development procedure, two hypotheses were applied to describe the internal mass transfer resistance. First, the mass transfer coefficient constant was considered. Second, the mass transfer coefficient was considered as a function of the dye concentration in the adsorbent. The experimental breakthrough curves were obtained for different particle diameters of the adsorbent, flow rates, and feed dye concentrations in order to evaluate the predictive power of the models. The values of the mass transfer parameters of the mathematical models were estimated by using the downhill simplex optimization method. The results showed that the model that considered internal resistance with a variable mass transfer coefficient was more flexible than the other ones and this model described the dynamics of the adsorption process of the dye in the fixed-bed column better. Hence, this model can be used for optimization and column design purposes for the investigated systems and similar ones.

  10. The zero mass limit of Kerr and Kerr-(anti-)de-Sitter space-times: exact solutions and wormholes

    Science.gov (United States)

    Birkandan, T.; Hortaçsu, M.

    2018-03-01

    Heun-type exact solutions emerge for both the radial and the angular equations for the case of a scalar particle coupled to the zero mass limit of both the Kerr and Kerr-(anti)de-Sitter spacetime. Since any type D metric has Heun-type solutions, it is interesting that this property is retained in the zero mass case. This work further refutes the claims that M going to zero limit of the Kerr metric is both locally and globally the same as the Minkowski metric.

  11. Laser microprobe mass spectrometry: Potential and limitations for inorganic and organic micro-analysis. Pt. 2

    International Nuclear Information System (INIS)

    Vaeck, I. van; Gijbels, R.

    1990-01-01

    Laser microprobe mass spectrometry (LMMS) employs a highly focused UV laser beam to ionise a microvolume in the order of 1 μm 3 . The produced ions are then mass-separated in a time-of-flight (TOF) or a Fourier Transform (FT) mass spectrometer. The technique allows element localisation, detailed speciation of inorganic substances and structural information of organic molecules. Inorganic applications are treated in the preceding part. This paper will focus on the organic aspects. Selected examples illustrate that TOF LMMS can achieve structural characterisation of molecules, untractable by conventional mass spectrometric techniques. Applicability to the analysis with high spatial resolution is shown and the need for surface availability of organic target molecules is discussed. The recently developed FT LMMS may fulfil the need for better mass resolution. However, the comparability of FT LMMS results with TOF LMMS data is not yet obvious. (orig.)

  12. The Top Quark Mass, Systematic Limitations, and my Tracker-Driven Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Garberson, Ford [Univ. of California, Santa Barbara, CA (United States)

    2008-08-01

    Top quark mass measurements have achieved an unexpected level of accu- racy in the last several years. This accuracy is only possible because of a new procedure that calibrates away the dominant jet energy uncertainty of past mea- surements. In this thesis I present some studies illustrating my suspicions that this procedure is leading them to claim overly optimistic results. Additionally, I present three measurements of the top quark mass that will be almost entirely independent of jet energies, and will thus serve as important cross checks of the standard measurements once enough statistics have been collected. I perform my measurements of the top quark mass in the lepton plus jets channel with approximately 1.9 fb-1 of integrated luminosity collected with the CDF detector using quantities with minimal dependence on the jet energies. One measurement exploits the transverse decay length of b-tagged jets to determine a top quark mass of 166.9+9.5 (stat)±2.9 (syst) GeV/c2, and another the transverse momentum of electrons and muons from W decays to determine a top quark mass of 173.5+8.8 - (stat) ± 3.8 (syst) GeV/c2. I combine these quantities in a vi third, simultaneous mass measurement to determine a top quark mass of 170.7 ± 6.3 (stat) ± 2.6 (syst) GeV/c2.

  13. Limits on the Mass and Abundance of Primordial Black Holes from Quasar Gravitational Microlensing

    Energy Technology Data Exchange (ETDEWEB)

    Mediavilla, E. [Instituto de Astrofísica de Canarias, Vía Láctea S/N, La Laguna E-38200, Tenerife (Spain); Jiménez-Vicente, J.; Calderón-Infante, J. [Departamento de Física Teórica y del Cosmos, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada (Spain); Muñoz, J. A.; Vives-Arias, H. [Departamento de Astronomía y Astrofísica, Universidad de Valencia, E-46100 Burjassot, Valencia (Spain)

    2017-02-20

    The idea that dark matter can be made of intermediate-mass primordial black holes (PBHs) in the 10 M {sub ⊙} ≲ M ≲ 200 M {sub ⊙} range has recently been reconsidered, particularly in the light of the detection of gravitational waves by the LIGO experiment. The existence of even a small fraction of dark matter in black holes should nevertheless result in noticeable quasar gravitational microlensing. Quasar microlensing is sensitive to any type of compact objects in the lens galaxy, to their abundance, and to their mass. We have analyzed optical and X-ray microlensing data from 24 gravitationally lensed quasars to estimate the abundance of compact objects in a very wide range of masses. We conclude that the fraction of mass in black holes or any type of compact objects is negligible outside of the 0.05 M {sub ⊙} ≲ M ≲ 0.45 M {sub ⊙} mass range and that it amounts to 20% ± 5% of the total matter, in agreement with the expected masses and abundances of the stellar component. Consequently, the existence of a significant population of intermediate-mass PBHs appears to be inconsistent with current microlensing observations. Therefore, primordial massive black holes are a very unlikely source of the gravitational radiation detected by LIGO.

  14. Experimental design for estimating parameters of rate-limited mass transfer: Analysis of stream tracer studies

    Science.gov (United States)

    Wagner, Brian J.; Harvey, Judson W.

    1997-01-01

    Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or subsurface water where flow is stagnant or slow moving. We present a methodology for (1) evaluating and comparing alternative stream tracer experiment designs and (2) identifying those combinations of stream transport properties that pose limitations to parameter estimation and therefore a challenge to tracer test design. The methodology uses the concept of global parameter uncertainty analysis, which couples solute transport simulation with parameter uncertainty analysis in a Monte Carlo framework. Two general conclusions resulted from this work. First, the solute injection and sampling strategy has an important effect on the reliability of transport parameter estimates. We found that constant injection with sampling through concentration rise, plateau, and fall provided considerably more reliable parameter estimates than a pulse injection across the spectrum of transport scenarios likely encountered in high-gradient streams. Second, for a given tracer test design, the uncertainties in mass transfer and storage-zone parameter estimates are strongly dependent on the experimental Damkohler number, DaI, which is a dimensionless combination of the rates of exchange between the stream and storage zones, the stream-water velocity, and the stream reach length of the experiment. Parameter uncertainties are lowest at DaI values on the order of 1.0. When DaI values are much less than 1.0 (owing to high velocity, long exchange timescale, and/or short reach length), parameter uncertainties are high because only a small amount of tracer interacts with storage zones in the reach. For the opposite conditions (DaI ≫ 1.0), solute

  15. Agent-Based Simulation of Mass Shootings: Determining How to Limit the Scale of a Tragedy

    OpenAIRE

    Roy Hayes; Reginald Hayes

    2014-01-01

    An agent-based simulation was created to examine key parameters in mass shootings. The goal of the simulation was to examine the potential effectiveness of Senator Dianne Feinstein’s (D-Calif.) assault weapons and high-capacity magazines bill. Based on the analysis, the proposed law would have a negligible effect on the number of people shot during mass shootings. The assault weapons portion of the proposed bill will have no effect on the number of people killed or wounded in a mass shootin...

  16. Interaction of ultra-high intensity laser pulse with a mass limited targets

    International Nuclear Information System (INIS)

    Andreev, A.A.; Platonov, K.Yu.; Limpouch, J.; Psikal, J.; Kawata, S.

    2006-01-01

    Complete test of publication follows. Ultra-high intensity laser pulses may be produced now via CPA scheme by using very short laser pulses of a relatively low energy. Interaction of such pulses with massive target is not very efficient as the energy delivered to charged particles spreads out quickly over large distances and it is redistributed between many secondary particles. One possibility to limit this undesirable energy spread is to use mass limited targets (MLT), for example droplets, big clusters or small foil sections. This is an intermediate regime in target dimensions between bulk solid and nanometer-size atomic cluster targets. A few experimental and theoretical studies have been carried out on laser absorption, fast particle generation and induced nuclear fusion reactions in the interaction of ultrashort laser pulses with MLT plasma. We investigate here laser interactions with MLT via 2D3V relativistic electromagnetic PIC simulations. We assume spherical droplet as a typical MLT. However, the sphere is represented in 2D simulations by an infinite cylinder irradiated uniformly along its length. We assume that MLT is fully ionized before main pulse interaction either due to insufficient laser contrast or due to a prepulse. For simplicity, we assume homogeneous plasma of high initial temperature. We analyze the interaction of relativistic laser pulses of various polarizations with targets of different shapes, such as a foil, quadrant and sphere. The mechanisms of laser absorption, electron and ion acceleration are clarified for different laser and target parameters. When laser interacts with the target front side, kinetic energy of electrons rises rapidly with fast oscillations in the kinetic and field energy, caused by electron oscillations in the laser field. Small energy oscillations, observed later, are caused by the electron motion back and forth through the droplet. Approximately 40% of laser energy is transferred to the kinetic energy of electrons

  17. Limit to mass sensitivity of nanoresonators with random rough surfaces due to intrinsic sources and interactions with the surrounding gas

    NARCIS (Netherlands)

    Palasantzas, G.

    2008-01-01

    We investigate initially the influence of thermomechanical and momentum exchange noise on the limit to mass sensitivity Delta m of nanoresonators with random rough surfaces, which are characterized by the roughness amplitude w, the correlation length xi, and the roughness exponent 0

  18. Influence of external mass transfer limitation on apparent kinetic parameters of penicillin G acylase immobilized on nonporous ultrafine silica particles.

    Science.gov (United States)

    Kheirolomoom, Azadeh; Khorasheh, Farhad; Fazelinia, Hossein

    2002-01-01

    Immobilization of enzymes on nonporous supports provides a suitable model for investigating the effect of external mass transfer limitation on the reaction rate in the absence of internal diffusional resistance. In this study, deacylation of penicillin G was investigated using penicillin acylase immobilized on ultrafine silica particles. Kinetic studies were performed within the low-substrate-concentration region, where the external mass transfer limitation becomes significant. To predict the apparent kinetic parameters and the overall effectiveness factor, knowledge of the external mass transfer coefficient, k(L)a, is necessary. Although various correlations exist for estimation of k(L)a, in this study, an optimization scheme was utilized to obtain this coefficient. Using the optimum values of k(L)a, the initial reaction rates were predicted and found to be in good agreement with the experimental data.

  19. Calibration and Limitations of the Mg II Line-based Black Hole Masses

    Science.gov (United States)

    Woo, Jong-Hak; Le, Huynh Anh N.; Karouzos, Marios; Park, Dawoo; Park, Daeseong; Malkan, Matthew A.; Treu, Tommaso; Bennert, Vardha N.

    2018-06-01

    We present single-epoch black hole mass ({M}BH}) calibrations based on the rest-frame ultraviolet (UV) and optical measurements of Mg II 2798 Å and Hβ 4861 Å lines and the active galactic nucleus (AGN) continuum, using a sample of 52 moderate-luminosity AGNs at z ∼ 0.4 and z ∼ 0.6 with high-quality Keck spectra. We combine this sample with a large number of luminous AGNs from the Sloan Digital Sky Survey to increase the dynamic range for a better comparison of UV and optical velocity and luminosity measurements. With respect to the reference {M}BH} based on the line dispersion of Hβ and continuum luminosity at 5100 Å, we calibrate the UV and optical mass estimators by determining the best-fit values of the coefficients in the mass equation. By investigating whether the UV estimators show a systematic trend with Eddington ratio, FWHM of Hβ, Fe II strength, or UV/optical slope, we find no significant bias except for the slope. By fitting the systematic difference of Mg II-based and Hβ-based masses with the L 3000/L 5100 ratio, we provide a correction term as a function of the spectral index as ΔC = 0.24 (1 + α λ ) + 0.17, which can be added to the Mg II-based mass estimators if the spectral slope can be well determined. The derived UV mass estimators typically show >∼0.2 dex intrinsic scatter with respect to the Hβ-based {M}BH}, suggesting that the UV-based mass has an additional uncertainty of ∼0.2 dex, even if high-quality rest-frame UV spectra are available.

  20. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  1. Laser microprobe mass spectrometry: Potential and limitations for inorganic and organic micro-analysis. Pt. 1

    International Nuclear Information System (INIS)

    Vaeck, I. van; Gijbels, R.

    1990-01-01

    Laser microprobe mass spectrometry (LMMS) employs a highly focused UV laser beam to ionise a microvolume in the order of 1 μm 3 . The ions produced are then mass-separated in a time-of-flight (TOF) or a Fourier Transform (FT) mass spectrometer. TOF LMMS allows element localisation, detailed speciation of inorganic substances and structural information of organic molecules. Quantitation is difficult. This paper focuses on instrumental aspects and inorganic analysis. Organic applications are treated in part II of this series. Selected examples illustrate that TOF LMMS is a valuable tool for the qualitative characterisation of micro-samples. Also, the applicability to the analysis with high spatial resolution is shown. The current technology and the prospects from the recent FTMS development are discussed. (orig.)

  2. Low appendicular skeletal muscle mass (ASM) with limited mobility and poor health outcomes in middle-aged African Americans.

    Science.gov (United States)

    Malmstrom, Theodore K; Miller, Douglas K; Herning, Margaret M; Morley, John E

    2013-09-01

    Recent efforts to provide a consensus definition propose that sarcopenia be considered a clinical syndrome associated with the loss of both skeletal muscle mass and muscle function that occurs with aging. Validation of sarcopenia definitions that include both low muscle mass and poor muscle function is needed. In the population-based African American Health (AAH) study (N = 998 at baseline/wave 1), muscle mass and mobility were evaluated in a clinical testing center in a subsample of N = 319 persons (ages 52-68) at wave 4 (2004). Muscle mass was measured using dual energy x-ray absorptiometry and mobility by a 6-min walk test and 4-m gait walk test. Height corrected appendicular skeletal mass (ASM; 9.0 ± 1.5 in n = 124 males, 8.3 ± 2.2 in n = 195 females) was computed as total lean muscle mass in arms and legs (kilograms) divided by the square of height (meters). Cross-sectional and longitudinal (6-year) associations of low ASM (bottom 25 % AAH sample; ASM with limited mobility (4-m gait walk ≤1 m/s or 6-min walk ASM with limited mobility was associated with IADL difficulties (p = .008) and frailty (p = .040) but not with ADL difficulties or falls in cross-sectional analyses; and with ADL difficulties (p = .022), IADL difficulties (p = .006), frailty (p = .039), and mortality (p = .003) but not with falls in longitudinal analyses adjusted for age and gender. Low ASM alone was marginally associated with mortality (p = .085) but not with other outcomes in cross-sectional or longitudinal analyses. Low ASM with limited mobility is associated with poor health outcomes among late middle-aged African Americans.

  3. Mass of the Stabilized Radion in the Limit of Finite Quartic Coupling

    Directory of Open Access Journals (Sweden)

    Ali Tofighi

    2017-01-01

    Full Text Available We present an exact treatment of the modulus stabilization condition with the general boundary conditions of the bulk scalar field in the Randall-Sundrum model. We find analytical expressions for the value of the modulus and the mass of the radion.

  4. Limit on the anti nu/sub e/ mass in free molecular tritium beta decay

    International Nuclear Information System (INIS)

    Bowles, T.J.; Wilkerson, J.F.; Browne, J.C.; Maley, M.P.; Robertson, R.G.H.; Knapp, D.A.; Helffrich, J.A.

    1986-01-01

    The question of a nonzero neutrino mass has received considerable attention since the claims of Lyubimov et al in 1980 were published which showed evidence for an electron antineutrino mass between 14 and 46 eV, with a best fit value of 35 eV. However, there are still considerable concerns about possible systematic problems in thier experiment. Many of these concerns revolve around the use of a tritiated valine source, in which the energy given up in final state excitations of the molecule following the veta decay of one of the tritium atoms is comparable to the size of the neutrino mass observed. The effect of these final state effects is difficult to calculate in a molecule as complex as valine. In addition, ionization energy loss and backscattering of the betas in traversing the solid source are appreciable and must be very accurately accounted for. These concerns have led us to carry out an experiment using free molecular tritium as the source material. The final state effects have been accurately calculated for the tritium molecule and the uncertainties in these calculations cannot generate a spurious neutrino mass greater than 1 eV. in addition, the energy loss in the source is small because the source consists of tritium only and there is no backscattering

  5. Dynamical instability of the envelope of red supergiants and the lower mass limit for carbon detonation supernovae

    International Nuclear Information System (INIS)

    Fujimoto, M.Y.; Nomoto, K.; Sugimoto, D.

    1976-01-01

    The lower mass limit Msub(l) for the carbon detonation supernovae was investigated by testing the dynamical instability of the envelopes of red supergiants. It was found that the dependence of Msub(l) on the mixing length l of convection is appreciable. As a smaller value of l is assumed, Msub(l) becomes larger. It may be as large as 8 solar masses if l is a third of the pressure scale-height. This is one of the ways to remove the difficulty of overproduction of iron-peak elements involved in the model of the carbon detonation supernovae. (Auth.)

  6. Dynamical instability of the envelope of red supergiants and the lower mass limit for carbon detonation supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, M Y [Tokyo Univ. (Japan); Nomoto, K; Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education

    1976-11-01

    The lower mass limit Msub(l) for the carbon detonation supernovae was investigated by testing the dynamical instability of the envelopes of red supergiants. It was found that the dependence of Msub(l) on the mixing length l of convection is appreciable. As a smaller value of l is assumed, Msub(l) becomes larger. It may be as large as 8 solar masses if l is a third of the pressure scale-height. This is one of the ways to remove the difficulty of overproduction of iron-peak elements involved in the model of the carbon detonation supernovae.

  7. The impact of mass transfer limitations on size distributions of particle associated SVOCs in outdoor and indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cong; Zhang, Yinping [Department of Building Science, Tsinghua University, Beijing (China); Weschler, Charles J., E-mail: weschlch@rwjms.rutgers.edu [Department of Building Science, Tsinghua University, Beijing (China); Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ (United States); International Center for Indoor Environment and Energy, Technical University of Denmark, Lyngby (Denmark)

    2014-11-01

    Semi-volatile organic compounds (SVOCs) partition between the gas phase and airborne particles. The size distribution of particle-associated SVOCs impacts their fate in outdoor and indoor environments, as well as human exposure to these compounds and subsequent health risks. Allen et al. (1996) previously proposed that the rate of mass transfer can impact polycyclic aromatic hydrocarbon (PAH) partitioning among different sized particles, especially for time scales relevant to urban aerosols. The present study quantitatively builds on this idea, presenting a model that incorporates dynamic SVOC/particle interaction and applying this model to typical outdoor and indoor scenarios. The model indicates that the impact of mass transfer limitations on the size distribution of a particle-associated SVOC can be evaluated by the ratio of the time to achieve gas–particle equilibrium relative to the residence time of particles. The higher this ratio, the greater the influence of mass transfer limitations on the size distribution of particle-associated SVOCs. The influence of such constraints is largest on the fraction of particle-associated SVOCs in the coarse mode (> 2 μm). Predictions from the model have been found to be in reasonable agreement with size distributions measured for PAHs at roadside and suburban locations in Japan. The model also quantitatively explains shifts in the size distributions of particle associated SVOCs compared to those for particle mass, and the manner in which these shifts vary with temperature and an SVOC's molecular weight. - Highlights: • Rate of mass transfer can impact SVOC partitioning among different sized particles. • Model was developed that incorporates dynamic SVOC/particle sorption. • Key parameters: mass-transfer coefficients, partition coefficient, residence time • Model explains observed SVOC size distribution shifts with temperature and MW. • Largest impact of mass transfer constraints: SVOC sorption to coarse

  8. Quantum limitations on the sensitivity of gravitational wave detectors with free masses

    International Nuclear Information System (INIS)

    Tsyplyaev, S.A.

    1989-01-01

    The problem of recording a classical disturbance by tracking the coordinate of a free particle is examined within the scope of nonrelativistic quantum mechanics. The absence of the fundamental limitation on the sensitivity - the standard quantum limit - is proven. An arbitrarily small disturbance can be recorded with preparation of the system in a quantum state having a negative quantum correlation coefficient between the observable coordinate and momentum. It is shown that it belongs to the collective coherent states - the condensed states. Arguments are presented for the absence of fundamental quantum limits on the magnitude of the recordable disturbance in the measurement of an arbitrary observable with a continuous spectrum

  9. Measurement of the High-Mass Drell-Yan Cross Section and Limits on Quark-Electron Compositeness Scales

    International Nuclear Information System (INIS)

    Grinstein, S.; Mostafa, M.; Piegaia, R.; Alves, G.A.; Carvalho, W.; Maciel, A.K.; Motta, H. da; Oliveira, E.; Santoro, A.; Lima, J.G.; Oguri, V.; Gomez, B.; Hoeneisen, B.; Mooney, P.; Negret, J.P.; Ducros, Y.; Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B.; Shivpuri, R.K.; Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Parua, N.; Shankar, H.C.; Park, Y.M.; Choi, S.; Kim, S.K.; Castilla-Valdez, H.; Gonzalez Solis, J.L.; Hernandez-Montoya, R.; Magana-Mendoza, L.; Sanchez-Hernandez, A.; Pawlik, B.; Gavrilov, V.; Gershtein, Y.; Kuleshov, S.; Belyaev, A.; Dudko, L.V.; Ermolov, P.; Karmanov, D.; Leflat, A.; Manankov, V.; Merkin, M.; Shabalina, E.; Abramov, V.; Babintsev, V.V.; Bezzubov, V.A.; Bojko, N.I.; Burtovoi, V.S.; Chekulaev, S.V.; Denisov, S.P.; Dyshkant, A.; Eroshin, O.V.; Evdokimov, V.N.; Galyaev, A.N.; Goncharov, P.I.; Gurzhiev, S.N.; Kostritskiy, A.V.; Kozelov, A.V.; Kozlovsky, E.A.; Mayorov, A.A.; Babukhadia, L.; Davis, K.; Fein, D.; Forden, G.E.; Guida, J.A.; Johns, K.; Nang, F.; Narayanan, A.; Rutherfoord, J.; Shupe, M.; Aihara, H.; Barberis, E.; Clark, A.R.

    1999-01-01

    We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120 pb -1 of data collected in p bar p collisions at √ (s) =1.8 TeV by the D0 Collaboration during 1992 - 1996. No deviation from standard model expectations is observed. We use the data to set limits on the quark-electron compositeness scale. The 95% confidence level lower limits on the compositeness scale vary between 3.3 and 6.1thinspthinspTeV depending on the assumed form of the effective contact interaction. copyright 1999 The American Physical Society

  10. Low mass SN Ia and the late light curve

    International Nuclear Information System (INIS)

    Colgate, S.A.; Fryer, C.L.

    1995-01-01

    The late bolometric light curves of type Ia supernovae, when measured accurately over several years, show an exponential decay with a 56d half-life over a drop in luminosity of 8 magnitudes (10 half-lives). The late-time light curve is thought to be governed by the decay of Co 56 , whose 77d half-life must then be modified to account for the observed decay time. Two mechanisms, both relying upon the positron fraction of the Co 56 decay, have been proposed to explain this modification. One explanation requires a large amount of emission at infra-red wavelengths where it would not be detected. The other explanation has proposed a progressive transparency or leakage of the high energy positrons (Colgate, Petschek and Kriese, 1980). For the positrons to leak out of the expanding nebula at the required rate necessary to produce the modified 56d exponential, the mass of the ejecta from a one foe (10 51 erg in kinetic energy) explosion must be small, M ejec = 0.4M circle-dot with M ejec ∝ KE 0.5 . Thus, in this leakage explanation, any reasonable estimate of the total energy of the explosion requires that the ejected mass be very much less than the Chandrasekhar mass of 1.4M circle-dot . This is very difficult to explain with the ''canonical'' Chandrasekhar-mass thermonuclear explosion that disintegrates the original white dwarf star. This result leads us to pursue alternate mechanisms of type Ia supernovae. These mechanisms include sub-Chandrasekhar thermonuclear explosions and the accretion induced collapse of Chandrasekhar mass white dwarfs. We will summarize the advantages and disadvantages of both mechanisms with considerable detail spent on our new accretion induced collapse simulations. These mechanisms lead to lower Ni 56 production and hence result in type Ia supernovae with luminosities decreased down to ∼ 50% that predicted by the ''standard'' model

  11. Limits on cosmological variation of strong interaction and quark masses from big bang nucleosynthesis, cosmic, laboratory and Oklo data

    International Nuclear Information System (INIS)

    Flambaum, V.V.; Shuryak, E.V.

    2002-01-01

    Recent data on the cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra have inspired a more general discussion of the possible variation of other constants. We discuss the variation of strong scale and quark masses. We derive limits on their relative change from (i) primordial big bang nucleosynthesis, (ii) the Oklo natural nuclear reactor, (iii) quasar absorption spectra, and (iv) laboratory measurements of hyperfine intervals

  12. Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Giacintucci, Simona; Clarke, Tracy E. [Naval Research Laboratory, 4555 Overlook Avenue SW, Code 7213, Washington, DC 20375 (United States); Markevitch, Maxim [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cassano, Rossella; Venturi, Tiziana; Brunetti, Gianfranco, E-mail: simona.giacintucci@nrl.navy.mil [INAF—Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy)

    2017-06-01

    We investigate the occurrence of radio minihalos—diffuse radio sources of unknown origin observed in the cores of some galaxy clusters—in a statistical sample of 58 clusters drawn from the Planck Sunyaev–Zel’dovich cluster catalog using a mass cut ( M {sub 500} > 6 × 10{sup 14} M {sub ⊙}). We supplement our statistical sample with a similarly sized nonstatistical sample mostly consisting of clusters in the ACCEPT X-ray catalog with suitable X-ray and radio data, which includes lower-mass clusters. Where necessary (for nine clusters), we reanalyzed the Very Large Array archival radio data to determine whether a minihalo is present. Our total sample includes all 28 currently known and recently discovered radio minihalos, including six candidates. We classify clusters as cool-core or non-cool-core according to the value of the specific entropy floor in the cluster center, rederived or newly derived from the Chandra X-ray density and temperature profiles where necessary (for 27 clusters). Contrary to the common wisdom that minihalos are rare, we find that almost all cool cores—at least 12 out of 15 (80%)—in our complete sample of massive clusters exhibit minihalos. The supplementary sample shows that the occurrence of minihalos may be lower in lower-mass cool-core clusters. No minihalos are found in non-cool cores or “warm cores.” These findings will help test theories of the origin of minihalos and provide information on the physical processes and energetics of the cluster cores.

  13. Improved squark and gluino mass limits from searches for supersymmetry at hadron colliders

    NARCIS (Netherlands)

    Beenakker, W.; Brensing, S.; D'Onofrio, M.; Krämer, M.; Kulesza, A.; Laenen, E.; Martinzez, M.; Niessen, I.

    2012-01-01

    Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the

  14. Neutron star mass limit at 2M{sub ⊙} supports the existence of a CEP

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Castillo, D. [JINR Dubna, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation); Benic, S. [University of Zagreb, Department of Physics, Zagreb (Croatia); Blaschke, D. [JINR Dubna, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation); National Research Nuclear University (MEPhI), Moscow (Russian Federation); University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); Han, Sophia [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN (United States); Typel, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2016-08-15

    We point out that the very existence of a ''horizontal branch'' in the mass-radius characteristics for neutron stars indicates a strong first-order phase transition and thus supports the existence of a critical endpoint (CEP) of first-order phase transitions in the QCD phase diagram. This branch would sample a sequence of hybrid stars with quark matter core, leading to the endpoint of stable compact star configurations with the highest possible baryon densities. Since we know of the existence of compact stars with 2M{sub ⊙}, this hypothetical branch has to lie in the vicinity of this mass value, if it exists. We report here a correlation between the maximal radius of the horizontal branch and the pressure at the onset of hadron-to-quark matter phase transition, which is likely to be a universal quantity of utmost relevance to the upcoming experiments with heavy-ion collisions at NICA and FAIR. (orig.)

  15. Testing the limits in a greenhouse ocean: Did low nitrogen availability limit marine productivity during the end-Triassic mass extinction?

    Science.gov (United States)

    Schoepfer, Shane D.; Algeo, Thomas J.; Ward, Peter D.; Williford, Kenneth H.; Haggart, James W.

    2016-10-01

    The end-Triassic mass extinction has been characterized as a 'greenhouse extinction', related to rapid atmospheric warming and associated changes in ocean circulation and oxygenation. The response of the marine nitrogen cycle to these oceanographic changes, and the extent to which mass extinction intervals represent a deviation in nitrogen cycling from other ice-free 'greenhouse' periods of Earth history, remain poorly understood. The well-studied Kennecott Point section in Haida Gwaii, British Columbia, Canada, was deposited in the open Panthalassic Ocean, and is used here as a test case to better understand changes in the nitrogen cycle and marine productivity from the pre-crisis greenhouse of the Rhaetian to the latest-Rhaetian crisis interval. We estimated marine productivity from the late Norian to the early Hettangian using TOC- and P-based paleoproductivity transform equations, and then compared these estimates to records of sedimentary nitrogen isotopes, redox-sensitive trace elements, and biomarker data. Major negative excursions in δ15N (to ≤ 0 ‰) correspond to periods of depressed marine productivity. During these episodes, the development of a stable pycnocline below the base of the photic zone suppressed vertical mixing and limited N availability in surface waters, leading to low productivity and increased nitrogen fixation, as well as ecological stresses in the photic zone. The subsequent shoaling of euxinic waters into the ocean surface layer was fatal for most Triassic marine fauna, although the introduction of regenerated NH4+ into the photic zone may have allowed phytoplankton productivity to recover. These results indicate that the open-ocean nitrogen cycle was influenced by climatic changes during the latest Triassic, despite having existed in a greenhouse state for over 50 million years previously, and that low N availability limited marine productivity for hundreds of thousands of years during the end-Triassic crisis.

  16. Mass loss by stars at the stage of the asymptotic giant branch

    International Nuclear Information System (INIS)

    Frantsman, Y.L.

    1986-01-01

    For a given initial stellar mass function, star formation function, and initial chemical composition, distributions have been constructed for stars of the asymptotic giant branch by luminosity, and for white dwarfs by mass, by calculating the approximate evolution of a large number of stars. Variants are calculated with different assumptions about the mass loss in the asymptotic branch. Theory can be reconciled with observation only if it is assumed that at this stage there is also a still large mass loss in addition to the stellar wind and the ejection of a planetary nebula shell. This provides the explanation for the absence in the Magellanic clouds of carbon stars with M /sub bol/ 1.0M /sub ./. The degenerate carbon-oxygen nuclei of stars evolving along the asymptotic giant branch cannot attain the Chandrasekhar limit on account of the great mass loss by the stars. The luminosity of stars of the asymptotic giant branch in the globular clusters of the Magellanic Clouds is a good indicator of the age of the clusters

  17. OBSERVATIONAL LIMITS ON THE GAS MASS OF A z = 4.9 GALAXY

    International Nuclear Information System (INIS)

    Livermore, R. C.; Swinbank, A. M.; Smail, Ian; Bower, R. G.; Coppin, K. E. K.; Edge, A. C.; Geach, J. E.; Richard, J.; Crain, R. A.

    2012-01-01

    We present the results of a search for molecular gas emission from a star-forming galaxy at z = 4.9. The galaxy benefits from magnification of 22 ± 5 × due to strong gravitational lensing by the foreground cluster MS1358+62. We target the CO(5-4) emission at a known position and redshift from existing Hubble Space Telescope/Advanced Camera for Surveys imaging and Gemini/NIFS [O II]3727 imaging spectroscopy, and obtain a tentative detection at the 4.3σ level with a flux of 0.104 ± 0.024 Jy km s –1 . From the CO line luminosity and assuming a CO-to-H 2 conversion factor α = 2, we derive a gas mass M gas ∼ 1 +1 –0.6 × 10 9 M ☉ . Combined with the existing data, we derive a gas fraction M gas /(M gas + M * ) = 0.59 +0.11 –0.06 . The faint line flux of this galaxy highlights the difficulty of observing molecular gas in representative galaxies at this epoch, and suggests that routine detections of similar galaxies in the absence of gravitational lensing will remain challenging even with ALMA in full science operations.

  18. Drift effect and "negative" mass transport in an inhomogeneous medium: limiting case of a two-component lattice gas.

    Science.gov (United States)

    Lukyanets, Sergei P; Kliushnychenko, Oleksandr V

    2010-11-01

    The mass transport in an inhomogeneous medium is modeled as the limiting case of a two-component lattice gas with excluded volume constraint and one of the components fixed. In the long-wavelength approximation, the density relaxation of mobile particles is governed by diffusion and interaction with a medium inhomogeneity represented by the static component distribution. It is shown that the density relaxation can be locally accompanied by density distribution compression, i.e., the local mass transport directed from low-to high-density regions. The origin of such a "negative" mass transport is shown to be associated with the presence of a stationary drift flow defined by the medium inhomogeneity. In the quasi-one-dimensional case, the compression dynamics manifests itself in the hoppinglike motion of packet front position of diffusing substance due to staged passing through inhomogeneity barriers, and it leads to fragmentation of the packet and retardation of its spreading. The root-mean-square displacement reflects only the averaged packet front dynamics and becomes inappropriate as the transport characteristic in this regime. In the stationary case, the mass transport throughout the whole system may be directed from the boundary with lower concentration towards the boundary with higher concentration. Implications of the excluded volume constraint and particle distinguishability for these effects are discussed.

  19. Improved detection limits for electrospray ionization on a magnetic sector mass spectrometer by using an array detector.

    Science.gov (United States)

    Cody, R B; Tamura, J; Finch, J W; Musselman, B D

    1994-03-01

    Array detection was compared with point detection for solutions of hen egg-white lysozyme, equine myoglobin, and ubiquitin analyzed by electrospray ionization with a magnetic sector mass spectrometer. The detection limits for samples analyzed by using the array detector system were at least 10 times lower than could be achieved by using a point detector on the same mass spectrometer. The minimum detectable quantity of protein corresponded to a signal-to-background ratio of approximately 2∶1 for a 500 amol/μL solution of hen egg-white lysozyme. However, the ultimate practical sample concentrations appeared to be in the 10-100 fmol/μL range for the analysis of dilute solutions of relatively pure proteins or simple mixtures.

  20. Chronic airflow limitation in a rural Indian population: etiology and relationship to body mass index

    Directory of Open Access Journals (Sweden)

    Chakrabarti B

    2011-10-01

    Full Text Available Biswajit Chakrabarti1, Sabita Purkait2, Punyabrata Gun2, Vicky C Moore3, Samadrita Choudhuri4, MJ Zaman5,6, Christopher J Warburton1, Peter MA Calverley7, Rahul Mukherjee3 1Aintree Chest Centre, University Hospital Aintree, Liverpool, UK; 2Moitri Swasthya Kendra, Shramajibi Swasthya Udyog, Chengail, West Bengal, India; 3Department of Respiratory Medicine and Physiology, Birmingham Heartlands Hospital, Birmingham, UK; 4National Medical College, Birgunj, Nepal; 5Department of Epidemiology and Public Health, University College, London, UK; 6The George Institute for Global Health, Sydney, Australia; 7Clinical Sciences Centre, University Hospital Aintree, Liverpool, UK Purpose: Respiratory conditions remain a source of morbidity globally. As such, this study aimed to explore factors associated with the development of airflow obstruction (AFO in a rural Indian setting and, using spirometry, study whether underweight is linked to AFO. Methods: Patients > 35 years old attending a rural clinic in West Bengal, India, took a structured questionnaire, had their body mass index (BMI measured, and had spirometry performed by an ancillary health care worker. Results: In total, 416 patients completed the study; spirometry was acceptable for analysis of forced expiratory volume in 1 second in 286 cases (69%; 16% were noted to exhibit AFO. Factors associated with AFO were: increasing age (95% confidence interval (CI 0.004–0.011; P = 0.005, smoking history (95% CI 0.07–0.174; P = 0.006, male gender (95% CI 0.19–0.47; P = 0.012, reduced BMI (95% CI 0.19–0.65; P = 0.02, and occupation (95% CI 0.12–0.84; P = 0.08. The mean BMI in males who currently smoked (n = 60; 19.29 kg/m2; standard deviation [SD] 3.46 was significantly lower than in male never smokers (n = 33; 21.15 kg/m2 SD 3.38; P < 0.001. AFO was observed in 27% of subjects with a BMI <18.5 kg/m2, falling to 13% with a BMI ≥18.5 kg/m2 (P = 0.013. AFO was observed in 11% of housewives, 22% of farm

  1. Subrahmanyan Chandrasekhar- Nobel Laureate

    Indian Academy of Sciences (India)

    undergraduate at the Presidency College,. Madras, when he began to ...... education programme, organized a Workshop on Materials and .... was also his teacher. He retired In 1970 .... structure of integrated pulse profiles; M Vivekanand and.

  2. Chandrasekhar: The all rounder

    Indian Academy of Sciences (India)

    recruited a young relativist (Sunil Maharaj) and we (Dan Krige and I) were anxious to ..... The wave normal curve in (ky, kx ) space is a circle of radius β/2ω whose origin is the dis- ... [2] A I Miller, Empire of the stars (Little, Brown, Boston, 2005).

  3. DID FOMALHAUT, HR 8799, AND HL TAURI FORM PLANETS VIA THE GRAVITATIONAL INSTABILITY? PLACING LIMITS ON THE REQUIRED DISK MASSES

    International Nuclear Information System (INIS)

    Nero, D.; Bjorkman, J. E.

    2009-01-01

    Disk fragmentation resulting from the gravitational instability has been proposed as an efficient mechanism for forming giant planets. We use the planet Fomalhaut b, the triple-planetary system HR 8799, and the potential protoplanet associated with HL Tau to test the viability of this mechanism. We choose the above systems since they harbor planets with masses and orbital characteristics favored by the fragmentation mechanism. We do not claim that these planets must have formed as the result of fragmentation, rather the reverse: if planets can form from disk fragmentation, then these systems are consistent with what we should expect to see. We use the orbital characteristics of these recently discovered planets, along with a new technique to more accurately determine the disk cooling times, to place both lower and upper limits on the disk surface density-and thus mass-required to form these objects by disk fragmentation. Our cooling times are over an order of magnitude shorter than those of Rafikov, which makes disk fragmentation more feasible for these objects. We find that the required mass interior to the planet's orbital radius is ∼0.1 M sun for Fomalhaut b, the protoplanet orbiting HL Tau, and the outermost planet of HR 8799. The two inner planets of HR 8799 probably could not have formed in situ by disk fragmentation.

  4. Limits on the masses of supersymmetric particles at $\\sqrt{s}$ up to 202 GeV

    CERN Document Server

    Espirito-Santo, M C; Johansson, P; Lipniacka, A; Mazzucato, F

    2001-01-01

    Searches for charginos, neutralinos, sleptons and squarks at LEP2 centre-of-mass energies ($\\sqrt{s}$) from 130 GeV to 202 GeV have been used to exclude regions of the MSSM parameter space and to set lower limits on the mass of the Lightest Supersymmetric Particle (LSP) and other supersymmetric particles within the MSSM framework. R-parity conservation has been assumed. The lightest neutralino was found to be heavier than 36.3~\\mbox{$ {\\mathrm{GeV}}/c^2$} independent of the $m_0$ value. The lightest chargino, the the sneutrino and the right-handed selectron were found to be heavier than 69.5~\\mbox{$ {\\mathrm{GeV}}/c^2$}, 83.0~\\mbox{$ {\\mathrm{GeV}}/c^2$}, and 91.0~\\mbox{$ {\\mathrm{GeV}}/c^2$}, respectively. The results do not depend on $m_0$ and are valid for $1 \\le $~tan$\\beta \\le 40 $, $M_2 \\le $~1000~\\mbox{${\\mathrm{GeV}}/c^2$}, and in the $\\mu$ region where the lightest neutralino is the LSP. The effects of mixings in the third family of sfermions are discussed. The confidence level of all limits given is...

  5. Blood group genotyping: the power and limitations of the Hemo ID Panel and MassARRAY platform.

    Science.gov (United States)

    McBean, Rhiannon S; Hyland, Catherine A; Flower, Robert L

    2015-01-01

    Matrix-assisted laser desorption/ionization, time-of-flight mass spectrometry (MALDI-TOF MS), is a sensitive analytical method capable of resolving DNA fragments varying in mass by a single nucleotide. MALDI-TOF MS is applicable to blood group genotyping, as the majority of blood group antigens are encoded by single nucleotide polymorphisms. Blood group genotyping by MALDI-TOF MS can be performed using a panel (Hemo ID Blood Group Genotyping Panel, Agena Bioscience Inc., San Diego, CA) that is a set of genotyping assays that predict the phenotype for 101 antigens from 16 blood group systems. These assays involve three fundamental stages: multiplex target-specific polymerase chain reaction amplification, allele-specific single base primer extension, and MALDI-TOFMS analysis using the MassARRAY system. MALDI-TOF MS-based genotyping has many advantages over alternative methods including high throughput, high multiplex capability, flexibility and adaptability, and the high level of accuracy based on the direct detection method. Currently available platforms for MALDI-TOF MS-based genotyping are not without limitations, including high upfront instrumentation costs and the number of non-automated steps. The Hemo ID Blood Group Genotyping Panel, developed and optimized in a collaboration between the vendor and the Blood Transfusion Service of the Swiss Red Cross in Zurich, Switzerland, is not yet widely utilized, although several laboratories are currently evaluating the MassARRAY system for blood group genotyping. Based on the accuracy and other advantages offered by MALDITOF MS analysis, in the future, this method is likely to become widely adopted for blood group genotyping, in particular, for population screening.

  6. PROBING THE LOWER MASS LIMIT FOR SUPERNOVA PROGENITORS AND THE HIGH-MASS END OF THE INITIAL-FINAL MASS RELATION FROM WHITE DWARFS IN THE OPEN CLUSTER M35 (NGC 2168)

    International Nuclear Information System (INIS)

    Williams, Kurtis A.; Bolte, Michael; Koester, Detlev

    2009-01-01

    We present a photometric and spectroscopic study of the white dwarf (WD) population of the populous, intermediate-age open cluster M35 (NGC 2168); this study expands upon our previous study of the WDs in this cluster. We spectroscopically confirm 14 WDs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 DB star. For each DA, we determine the WD mass and cooling age, from which we derive each star's progenitor mass. These data are then added to the empirical initial-final mass relation (IFMR), where the M35 WDs contribute significantly to the high-mass end of the relation. The resulting points are consistent with previously published linear fits to the IFMR, modulo moderate systematics introduced by the uncertainty in the star cluster age. Based on this cluster alone, the observational lower limit on the maximum mass of WD progenitors is found to be ∼5.1 M sun - 5.2 M sun at the 95% confidence level; including data from other young open clusters raises this limit to as high as 7.1 M sun , depending on the cluster membership of three massive WDs and the core composition of the most massive WDs. We find that the apparent distance modulus and extinction derived solely from the cluster WDs ((m - M) V = 10.45 ± 0.08 and E(B-V) = 0.185 ± 0.010, respectively) is fully consistent with that derived from main-sequence fitting techniques. Four M35 WDs may be massive enough to have oxygen-neon cores; the assumed core composition does not significantly affect the empirical IFMR. Finally, the two non-DA WDs in M35 are photometrically consistent with cluster membership; further analysis is required to determine their memberships.

  7. Radionuclide mass transfer rates from a pinhole in a waste container for an inventory-limited and a constant concentration source

    International Nuclear Information System (INIS)

    LeNeveu, D.M.

    1996-03-01

    Analytical solutions for transient and steady state diffusive mass transfer rates from a pinhole in a waste container are developed for constant concentration and inventory-limited source conditions. Mass transport in three media are considered, inside the pinhole (medium 2), outside the container (medium 3) and inside the container (medium 1). Simple equations are developed for radionuclide mass transfer rates from a pinhole. It is shown that the medium with the largest mass transfer resistance need only be considered to provide a conservative estimate of mass transfer rates. (author) 11 refs., 3 figs

  8. Protein biomarkers on tissue as imaged via MALDI mass spectrometry: A systematic approach to study the limits of detection.

    Science.gov (United States)

    van de Ven, Stephanie M W Y; Bemis, Kyle D; Lau, Kenneth; Adusumilli, Ravali; Kota, Uma; Stolowitz, Mark; Vitek, Olga; Mallick, Parag; Gambhir, Sanjiv S

    2016-06-01

    MALDI mass spectrometry imaging (MSI) is emerging as a tool for protein and peptide imaging across tissue sections. Despite extensive study, there does not yet exist a baseline study evaluating the potential capabilities for this technique to detect diverse proteins in tissue sections. In this study, we developed a systematic approach for characterizing MALDI-MSI workflows in terms of limits of detection, coefficients of variation, spatial resolution, and the identification of endogenous tissue proteins. Our goal was to quantify these figures of merit for a number of different proteins and peptides, in order to gain more insight in the feasibility of protein biomarker discovery efforts using this technique. Control proteins and peptides were deposited in serial dilutions on thinly sectioned mouse xenograft tissue. Using our experimental setup, coefficients of variation were biomarkers and a new benchmarking strategy that can be used for comparing diverse MALDI-MSI workflows. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Ages of Young Star Clusters, Massive Blue Stragglers, and the Upper Mass Limit of Stars: Analyzing Age-dependent Stellar Mass Functions

    NARCIS (Netherlands)

    Schneider, F.R.N.; Izzard, R.G.; de Mink, S.E.; Langer, N.; Stolte, A.; de Koter, A.; Gvaramadze, V.V.; Huβman, B.; Liermann, A.; Sana, H.

    2014-01-01

    Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass

  10. Ultrafast Desorption by Impulsive Vibrational Excitation (DIVE). Applications in laser surgery, mass spectrometry and towards ultimate limits in biodiagnosis

    International Nuclear Information System (INIS)

    Ren, Ling

    2015-07-01

    The prospects for minimally invasive surgery, spatial imaging with mass spectrometry and rapid high throughput biodiagnosis require new means of tissue incision and biomolecule extraction with conserved molecular structure. Towards this aim, a laser ablation process is utilized in this dissertation, which is capable of performing precise tissue incision with minimal collateral damage and extracting intact biological entities with conserved biological functions. The method is based on the recently developed Picosecond Infrared Laser (PIRL) designed to excite selectively the water vibrational modes under the condition of ultrafast Desorption by Impulsive Vibrational Excitation (DIVE). The basic concept is that the selectively excited water molecules act as propellant to ablate whole biological complexes into the plume, faster than any thermal deleterious effect or fragmentation that would mask molecular identities.The PIRL ablation under DIVE condition is applied for the first time to six types of ocular tissues, rendering precise and minimally invasive incisions in a well-controlled and reproducible way. An eminent demonstration is the contact-free and applanation-free corneal trephination with the PIRL. Mass spectrometry and other analytical techniques show that great abundance of proteins with various molecular weights are extracted from the tissue by the PIRL ablation, and that fragmentation or other chemical alternation does not occur to the proteins in the ablation plume. With various microscope imaging and biochemical analysis methods, nano-scale single protein molecules, viruses and cells in the ablation plume are found to be morphologically and functionally identical to their corresponding controls. The PIRL ablation provides a new means to push the frontiers of laser surgery in ophthalmology and can be applied to resolve chemical activities in situ and in vivo. The most important finding is the conserved nature of the extracted biological entities

  11. Ultrafast Desorption by Impulsive Vibrational Excitation (DIVE). Applications in laser surgery, mass spectrometry and towards ultimate limits in biodiagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Ling

    2015-07-15

    The prospects for minimally invasive surgery, spatial imaging with mass spectrometry and rapid high throughput biodiagnosis require new means of tissue incision and biomolecule extraction with conserved molecular structure. Towards this aim, a laser ablation process is utilized in this dissertation, which is capable of performing precise tissue incision with minimal collateral damage and extracting intact biological entities with conserved biological functions. The method is based on the recently developed Picosecond Infrared Laser (PIRL) designed to excite selectively the water vibrational modes under the condition of ultrafast Desorption by Impulsive Vibrational Excitation (DIVE). The basic concept is that the selectively excited water molecules act as propellant to ablate whole biological complexes into the plume, faster than any thermal deleterious effect or fragmentation that would mask molecular identities.The PIRL ablation under DIVE condition is applied for the first time to six types of ocular tissues, rendering precise and minimally invasive incisions in a well-controlled and reproducible way. An eminent demonstration is the contact-free and applanation-free corneal trephination with the PIRL. Mass spectrometry and other analytical techniques show that great abundance of proteins with various molecular weights are extracted from the tissue by the PIRL ablation, and that fragmentation or other chemical alternation does not occur to the proteins in the ablation plume. With various microscope imaging and biochemical analysis methods, nano-scale single protein molecules, viruses and cells in the ablation plume are found to be morphologically and functionally identical to their corresponding controls. The PIRL ablation provides a new means to push the frontiers of laser surgery in ophthalmology and can be applied to resolve chemical activities in situ and in vivo. The most important finding is the conserved nature of the extracted biological entities

  12. Effect of Protein Intake on Lean Body Mass in Functionally Limited Older Men: A Randomized Clinical Trial.

    Science.gov (United States)

    Bhasin, Shalender; Apovian, Caroline M; Travison, Thomas G; Pencina, Karol; Moore, Lynn L; Huang, Grace; Campbell, Wayne W; Li, Zhuoying; Howland, Andrew S; Chen, Ruo; Knapp, Philip E; Singer, Martha R; Shah, Mitali; Secinaro, Kristina; Eder, Richard V; Hally, Kathleen; Schram, Haley; Bearup, Richelle; Beleva, Yusnie M; McCarthy, Ashley C; Woodbury, Erin; McKinnon, Jennifer; Fleck, Geeta; Storer, Thomas W; Basaria, Shehzad

    2018-04-01

    The Institute of Medicine set the recommended dietary allowance (RDA) for protein at 0.8 g/kg/d for the entire adult population. It remains controversial whether protein intake greater than the RDA is needed to maintain protein anabolism in older adults. To investigate whether increasing protein intake to 1.3 g/kg/d in older adults with physical function limitations and usual protein intake within the RDA improves lean body mass (LBM), muscle performance, physical function, fatigue, and well-being and augments LBM response to a muscle anabolic drug. This randomized clinical trial with a 2 × 2 factorial design was conducted in a research center. A modified intent-to-treat analytic strategy was used. Participants were 92 functionally limited men 65 years or older with usual protein intake less thanor equal to 0.83 g/kg/d within the RDA. The first participant was randomized on September 21, 2011, and the last participant completed the study on January 19, 2017. Participants were randomized for 6 months to controlled diets with 0.8 g/kg/d of protein plus placebo, 1.3 g/kg/d of protein plus placebo, 0.8 g/kg/d of protein plus testosterone enanthate (100 mg weekly), or 1.3 g/kg/d of protein plus testosterone. Prespecified energy and protein contents were provided through custom-prepared meals and supplements. The primary outcome was change in LBM. Secondary outcomes were muscle strength, power, physical function, health-related quality of life, fatigue, affect balance, and well-being. Among 92 men (mean [SD] age, 73.0 [5.8] years), the 4 study groups did not differ in baseline characteristics. Changes from baseline in LBM (0.31 kg; 95% CI, -0.46 to 1.08 kg; P = .43) and appendicular (0.04 kg; 95% CI, -0.48 to 0.55 kg; P = .89) and trunk (0.24 kg; 95% CI, -0.17 to 0.66 kg; P = .24) lean mass, as well as muscle strength and power, walking speed and stair-climbing power, health-related quality of life, fatigue, and well-being, did not differ between men

  13. Binary black hole coalescence in the large-mass-ratio limit: The hyperboloidal layer method and waveforms at null infinity

    International Nuclear Information System (INIS)

    Bernuzzi, Sebastiano; Nagar, Alessandro; Zenginoglu, Anil

    2011-01-01

    We compute and analyze the gravitational waveform emitted to future null infinity by a system of two black holes in the large-mass-ratio limit. We consider the transition from the quasiadiabatic inspiral to plunge, merger, and ringdown. The relative dynamics is driven by a leading order in the mass ratio, 5PN-resummed, effective-one-body (EOB), analytic-radiation reaction. To compute the waveforms, we solve the Regge-Wheeler-Zerilli equations in the time-domain on a spacelike foliation, which coincides with the standard Schwarzschild foliation in the region including the motion of the small black hole, and is globally hyperboloidal, allowing us to include future null infinity in the computational domain by compactification. This method is called the hyperboloidal layer method, and is discussed here for the first time in a study of the gravitational radiation emitted by black hole binaries. We consider binaries characterized by five mass ratios, ν=10 -2,-3,-4,-5,-6 , that are primary targets of space-based or third-generation gravitational wave detectors. We show significative phase differences between finite-radius and null-infinity waveforms. We test, in our context, the reliability of the extrapolation procedure routinely applied to numerical relativity waveforms. We present an updated calculation of the final and maximum gravitational recoil imparted to the merger remnant by the gravitational wave emission, v kick end /(cν 2 )=0.04474±0.00007 and v kick max /(cν 2 )=0.05248±0.00008. As a self-consistency test of the method, we show an excellent fractional agreement (even during the plunge) between the 5PN EOB-resummed mechanical angular momentum loss and the gravitational wave angular momentum flux computed at null infinity. New results concerning the radiation emitted from unstable circular orbits are also presented. The high accuracy waveforms computed here could be considered for the construction of template banks or for calibrating analytic models such

  14. Missing mass spectra in hadronic events from $e^+ e^-$ collisions at $\\sqrt{s}$=161-172 GeV and limits on invisible Higgs decays

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Button, A M; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; Alessandro, R D; De Asmundis, R; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hong, S J; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sassowsky, M; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1998-01-01

    Events characterised by large hadronic energy and transverse momentum are selected from the data collected by the L3 detector at LEP at centre-of-mass energies between 161 and 172 GeV, corresponding to an integrated luminosity of 21 $\\rm pb^{-1}$. The visible mass and the missing mass distributions of the selected events are consistent with those expected from Standard Model processes. This result is combined with that from data taken at the Z resonance to set an upper limit on the production rate and decay into invisible final states of a non-minimal Higgs boson, as a function of the Higgs mass. Assuming the non-minimal Higgs production cross section to be the same as for the Standard Model Higgs boson and the decay branching fraction into invisible final states to be 100\\%, a Higgs mass lower limit of 69.6 GeV is derived at 95\\% confidence level.

  15. On the two-loop corrections to the pole mass of the B quark in the gaugeless limit of the MSSM

    International Nuclear Information System (INIS)

    Bednyakov, A.V.; Kazakov, D.I.; )

    2007-01-01

    The result for the two-loop corrections to the pole mass of the b quark in the gaugeless limit of the MSSM is presented. In this limit it is assumed that the contribution from the electroweak gauge interactions is small. The result presented here differs from one obtained earlier, especially in some particular regions of the MSSM parameter space [ru

  16. K{sub α} x-ray imaging of laser-irradiated, limited-mass zirconium foils

    Energy Technology Data Exchange (ETDEWEB)

    Storm, M.; Orban, C.; Jiang, S.; Freeman, R. R.; Akli, K. [Department of Physics, The Ohio State University, 191 West Woodruff Road, Columbus, Ohio 43210 (United States); Eichman, B.; Fiksel, G.; Stoeckl, C.; Theobald, W.; Delettrez, J. A. [The Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Dyer, G.; Ditmire, T. [The Texas Center of High Energy Density Science, The University of Texas at Austin, 2511 Speedway Street, Austin, Texas 78712 (United States); Stephens, R. [General Atomics, 3550 General Atomics Court, San Diego, California 92121-1200 (United States)

    2014-07-15

    X-ray fluorescence measurements to determine the effect of target heating on imaging efficiency, at a photon energy of 15.7 keV corresponding to the K{sub α} line of zirconium, have been carried out using limited-mass foils irradiated by the Texas Petawatt Laser. Zirconium foils that ranged in volume from 3000 × 3000 × 21 μm{sup 3} to 150 × 150 × 6 μm{sup 3} were irradiated with 100 J, 8 ps-long pulses and a mean intensity of 4 × 10{sup 19} W/cm{sup 2}. The K{sub α} emission was measured simultaneously using a highly ordered pyrolytic graphite crystal spectrometer and a curved quartz imaging crystal. The measured ratio of the integrated image signal to the integrated spectral signal was, within the experimental error, constant, indicating that the imaging efficiency's dependence on temperature is weak throughout the probed range. Based on our experience of target heating under similar conditions, we estimate a temperature of ∼200 eV for the smallest targets. The successful imaging of K{sub α} emission for temperatures this high represents an important proof of concept for Zr K{sub α} imaging. At these temperatures, the imaging of K{sub α} emission from lower-Z materials (such as Cu) is limited by temperature-dependent shifts in the K{sub α} emission energy.

  17. Strong Relation between Muscle Mass Determined by D3-creatine Dilution, Physical Performance and Incidence of Falls and Mobility Limitations in a Prospective Cohort of Older Men.

    Science.gov (United States)

    Cawthon, Peggy M; Orwoll, Eric S; Peters, Katherine E; Ensrud, Kristine E; Cauley, Jane A; Kado, Deborah M; Stefanick, Marcia L; Shikany, James M; Strotmeyer, Elsa S; Glynn, Nancy W; Caserotti, Paolo; Shankaran, Mahalakshmi; Hellerstein, Marc; Cummings, Steven R; Evans, William J

    2018-06-12

    Direct assessment of skeletal muscle mass in older adults is clinically challenging. Relationships between lean mass and late-life outcomes have been inconsistent. The D3-creatine dilution method provides a direct assessment of muscle mass. Muscle mass was assessed by D3-creatine (D3Cr) dilution in 1,382 men (mean age, 84.2 yrs). Participants completed the Short Physical Performance Battery (SPPB); usual walking speed (6 meters); and DXA lean mass. Men self-reported mobility limitations (difficulty walking 2-3 blocks or climbing 10 steps); recurrent falls (2+); and serious injurious falls in the subsequent year. Across quartiles of D3Cr muscle mass/body mass, multivariate linear models calculated means for SPPB and gait speed; multivariate logistic models calculated odds ratios for incident mobility limitations or falls. Compared to men in the highest quartile, those in the lowest quartile of D3Cr muscle mass/body mass had slower gait speed (Q1: 1.04 vs Q4: 1.17 m/s); lower SPPB (Q1: 8.4 vs Q4: 10.4 points); greater likelihood of incident serious injurious falls (OR Q1 vs Q4: 2.49, 95% CI: 1.37, 4.54); prevalent mobility limitation (OR Q1 vs Q4,: 6.1, 95%CI: 3.7, 10.3) and incident mobility limitation (OR Q1 vs Q4: 2.15 95% CI: 1.42, 3.26); p for trend strongly related to physical performance, mobility and incident injurious falls in older me.

  18. STRAIN-STRESS DISTRIBUTION OF “HOMOGENEOUS” SOIL MASS DURING THE LOAD TRANSMITTED THROUGH THE LIMITED AREA IN THE PLAN, APPLIED INSIDE THE ELASTIC HOMOGENEOUS SOIL MASS

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2017-03-01

    Full Text Available Summary. Based on the current understanding of the piles work in clayey soils; that is forming during driving process a compacted core (compacted platform in the pile tip plane and transferring the load from the pile (from the piling foundation not through the pile tip but through the pressed core (compacted platform, the stress in the soil mass by the load applied inside the elastic half-space is determined with the change in the calculated scheme of load transferring to the “homogeneous” soil mass.

  19. Limits on charmed-meson production in e+e- annihilation at 4.8-GeV center-of-mass energy

    International Nuclear Information System (INIS)

    Boyarski, A.M.; Breidenbach, M.; Bulos, F.

    1975-01-01

    Data from e + e - annihilation into hadrons at 4.8 GeV center-of-mass energy were used to search for charmed mesons in the mass range 1.5 to 4.0 GeV/c 2 . Narrow peaks in the invariant-mass distributions for K -+ π +- , K 0 /sub s/π + π - , π + π - , K + K - , K -+ , π +- π +- , K 0 /sub s/π +- , K 0 /sub s/K +- , and π + π - π +- were sought. Upper limits are presented for the inclusive production cross section times the branching ratio for charmed mesons having these decay modes. 2 figures, 1 table

  20. Compact stars and the evolution of binary systems

    NARCIS (Netherlands)

    van den Heuvel, E.P.J.

    2011-01-01

    The Chandrasekhar limit is of key importance for the evolution of white dwarfs in binary systems and for the formation of neutron stars and black holes in binaries. Mass transfer can drive a white dwarf in a binary over the Chandrasekhar limit, which may lead to a Type Ia supernova (in case of a CO

  1. PLANETS AROUND LOW-MASS STARS. III. A YOUNG DUSTY L DWARF COMPANION AT THE DEUTERIUM-BURNING LIMIT ,

    Energy Technology Data Exchange (ETDEWEB)

    Bowler, Brendan P.; Liu, Michael C. [Institute for Astronomy, University of Hawai' i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Shkolnik, Evgenya L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Dupuy, Trent J., E-mail: bpbowler@ifa.hawaii.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-09-01

    We report the discovery of an L-type companion to the young M3.5V star 2MASS J01225093-2439505 at a projected separation of 1.''45 ( Almost-Equal-To 52 AU) as part of our adaptive optics imaging search for extrasolar giant planets around young low-mass stars. 2MASS 0122-2439 B has very red near-infrared colors similar to the HR 8799 planets and the reddest known young/dusty L dwarfs in the field. Moderate-resolution (R Almost-Equal-To 3800) 1.5-2.4 {mu}m spectroscopy reveals a near-infrared spectral type of L4-L6 and an angular H-band shape, confirming its cool temperature and young age. The kinematics of 2MASS 0122-2439 AB are marginally consistent with members of the {approx}120 Myr AB Dor young moving group based on the photometric distance to the primary (36 {+-} 4 pc) and our radial velocity measurement of 2MASS 0122-2439 A from Keck/HIRES. We adopt the AB Dor group age for the system, but the high energy emission, lack of Li I {lambda}6707 absorption, and spectral shape of 2MASS 0122-2439 B suggest a range of {approx}10-120 Myr is possible. The age and luminosity of 2MASS 0122-2439 B fall in a strip where ''hot-start'' evolutionary model mass tracks overlap as a result of deuterium burning. Several known substellar companions also fall in this region (2MASS J0103-5515 ABb, AB Pic b, {kappa} And b, G196-3 B, SDSS 2249+0044 B, LP 261-75 B, HD 203030 B, and HN Peg B), but their dual-valued mass predictions have largely been unrecognized. The implied mass of 2MASS 0122-2439 B is Almost-Equal-To 12-13 M{sub Jup} or Almost-Equal-To 22-27 M{sub Jup} if it is an AB Dor member, or possibly as low as 11 M{sub Jup} if the wider age range is adopted. Evolutionary models predict an effective temperature for 2MASS 0122-2439 B that corresponds to spectral types near the L/T transition ( Almost-Equal-To 1300-1500 K) for field objects. However, we find a mid-L near-infrared spectral type, indicating that 2MASS 0122-2439 B represents another case

  2. PLANETS AROUND LOW-MASS STARS. III. A YOUNG DUSTY L DWARF COMPANION AT THE DEUTERIUM-BURNING LIMIT ,

    International Nuclear Information System (INIS)

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Dupuy, Trent J.

    2013-01-01

    We report the discovery of an L-type companion to the young M3.5V star 2MASS J01225093-2439505 at a projected separation of 1.''45 (≈52 AU) as part of our adaptive optics imaging search for extrasolar giant planets around young low-mass stars. 2MASS 0122-2439 B has very red near-infrared colors similar to the HR 8799 planets and the reddest known young/dusty L dwarfs in the field. Moderate-resolution (R ≈ 3800) 1.5-2.4 μm spectroscopy reveals a near-infrared spectral type of L4-L6 and an angular H-band shape, confirming its cool temperature and young age. The kinematics of 2MASS 0122-2439 AB are marginally consistent with members of the ∼120 Myr AB Dor young moving group based on the photometric distance to the primary (36 ± 4 pc) and our radial velocity measurement of 2MASS 0122-2439 A from Keck/HIRES. We adopt the AB Dor group age for the system, but the high energy emission, lack of Li I λ6707 absorption, and spectral shape of 2MASS 0122-2439 B suggest a range of ∼10-120 Myr is possible. The age and luminosity of 2MASS 0122-2439 B fall in a strip where ''hot-start'' evolutionary model mass tracks overlap as a result of deuterium burning. Several known substellar companions also fall in this region (2MASS J0103-5515 ABb, AB Pic b, κ And b, G196-3 B, SDSS 2249+0044 B, LP 261-75 B, HD 203030 B, and HN Peg B), but their dual-valued mass predictions have largely been unrecognized. The implied mass of 2MASS 0122-2439 B is ≈12-13 M Jup or ≈22-27 M Jup if it is an AB Dor member, or possibly as low as 11 M Jup if the wider age range is adopted. Evolutionary models predict an effective temperature for 2MASS 0122-2439 B that corresponds to spectral types near the L/T transition (≈1300-1500 K) for field objects. However, we find a mid-L near-infrared spectral type, indicating that 2MASS 0122-2439 B represents another case of photospheric dust being retained to cooler temperatures at low surface gravities, as seen in the spectra of young (8-30 Myr

  3. Low skeletal muscle mass is a predictive factor for chemotherapy dose-limiting toxicity in patients with locally advanced head and neck cancer

    NARCIS (Netherlands)

    Wendrich, Anne W; Swartz, Justin E; Bril, Sandra I; Wegner, Inge; de Graeff, Alexander; Smid, Ernst J; de Bree, Remco; Pothen, Ajit J

    OBJECTIVES: Low skeletal muscle mass (SMM) or sarcopenia is emerging as an adverse prognostic factor for chemotherapy dose-limiting toxicity (CLDT) and survival in cancer patients. Our aim was to determine the impact of low SMM on CDLT in patients with locally advanced head and neck squamous cell

  4. Abelian Chern-Simons theory as the strong large-mass limit of topologically massive abelian gauge theory: the Wilson loop

    International Nuclear Information System (INIS)

    Giavarini, G.; Martin, C.P.; Ruiz Ruiz, F.

    1993-01-01

    We show that the renormalized vacuum expectation value of the Wilson loop for topologically massive abelian gauge theory in bbfR 3 can be defined so that its large-mass limit be the renormalized vaccum expectation value of the Wilson loop for abelian Chern-Simons theory also in bbfR 3 . (orig.)

  5. Project 8, Phase III Design: Placing an eV-Scale Limit on the Neutrino Mass using Cyclotron Radiation Emission Spectroscopy

    Science.gov (United States)

    Oblath, Noah; Project 8 Collaboration

    2016-09-01

    We report on the design concept for Phase III of the Project 8 experiment. In the third phase of Project 8 we aim to place a limit on the neutrino mass that is similar to the current limits set by tritium beta-decay experiments, mν radioastronomy will be employed to search for and track electron signals in the fiducial volume. This talk will present the quantitative design concept for the phased-array receiver, and illustrate how we are progressing towards the Phase IV experiment, which will have sensitivity to the neutrino mass scale allowed by the inverted mass hierarchy. This work is supported by the DOE Office of Science Early Career Research Program, and the Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory.

  6. Search for Supersymmetric Particles in $e^{+}e^{-}$ Collisions at $\\sqrt{s}$ up to 202 GeV and Mass Limit for the Lightest Neutralino

    CERN Document Server

    Barate, R; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Jézéquel, S; Lees, J P; Martin, F; Merle, E; Minard, M N; Pietrzyk, B; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; López, J; Martínez, M; Merino, G; Miquel, R; Mir, L M; Pacheco, A; Paneque, D; Ruiz, H; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Azzurri, P; Barklow, Timothy L; Boix, G; Buchmüller, O L; Cattaneo, M; Cerutti, F; Clerbaux, B; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Gianotti, F; Greening, T C; Hansen, J B; Harvey, J; Hutchcroft, D E; Janot, P; Jost, B; Kado, M; Lemaître, V; Maley, P; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tournefier, E; Valassi, Andrea; Ward, J J; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Dessagne, S; Falvard, A; Fayolle, D; Gay, P; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Blondel, A; Brient, J C; Machefert, F P; Rougé, A; Swynghedauw, M; Tanaka, R; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Chalmers, M; Halley, A W; Kennedy, J; Lynch, J G; Negus, P; O'Shea, V; Räven, B; Smith, D; Teixeira-Dias, P; Thompson, A S; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hepp, V; Kluge, E E; Leibenguth, G; Putzer, A; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Davies, G; Dornan, Peter J; Girone, M; Marinelli, N; Nowell, J; Przysiezniak, H; Sedgbeer, J K; Thompson, J C; Thomson, E; White, R; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Pearson, M R; Robertson, N A; Smizanska, M; Giehl, I; Hölldorfer, F; Jakobs, K; Kleinknecht, K; Kröcker, M; Müller, A S; Nürnberger, H A; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H W; Zeitnitz, C; Ziegler, T; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Fouchez, D; Leroy, O; Kachelhoffer, T; Payre, P; Rousseau, D; Tilquin, A; Aleppo, M; Gilardoni, S S; Ragusa, F; David, A; Dietl, H; Ganis, G; Heister, A; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Stenzel, H; Wolf, G; Boucrot, J; Callot, O; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Serin, L; Veillet, J J; Videau, I; De Vivie de Régie, J B; Yuan, C; Zerwas, D; Bagliesi, G; Boccali, T; Calderini, G; Ciulli, V; Foà, L; Giammanco, A; Giassi, A; Ligabue, F; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Coles, J; Cowan, G D; Green, M G; Jones, L T; Medcalf, T; Strong, J A; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Bloch-Devaux, B; Boumediene, D E; Colas, P; Fabbro, B; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Rosowsky, A; Seager, P; Trabelsi, A; Tuchming, B; Vallage, B; Konstantinidis, N P; Loomis, C; Litke, A M; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Hodgson, P N; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Hess, J; Misiejuk, A; Prange, G; Sieler, U; Borean, C; Giannini, G; Gobbo, B; He, H; Pütz, J; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Cranmer, K; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Von Wimmersperg-Töller, J H; Walsh, J; Wiedenmann, W; Wu, J; Wu Sau Lan; Wu, X; Zobernig, G

    2001-01-01

    Searches for pair production of squarks, sleptons, charginos and neutralinos are performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies from 188.6 to 201.6 GeV. No evidence for any such signals is observed in a total integrated luminosity of about 410 pb**-1. The negative results of the searches are translated into exclusion domains in the space of the relevant MSSM parameters, which improve significantly on the constraints set previously. Under the assumptions of gaugino and sfermion mass unification, these results allow a 95% C.L. lower limit of 37 GeV/c**2 to be set on the mass of the lightest neutralino for any tan(beta) and sfermion mass. Additional constraints in the MSSM parameter space are derived from the negative results of ALEPH searches for Higgs bosons. The results are also interpreted in the framework of minimal supergravity.

  7. Limits on the production of large transverse momentum direct photons deduced from the measurement of low-mass electron pairs

    International Nuclear Information System (INIS)

    Cobb, J.H.; Iwata, S.; Palmer, R.B.; Rahm, D.C.; Rehak, P.; Stumer, I.; Fabjan, C.W.; Fowler, E.; Mannelli, I.; Mouzourakis, P.; Nakamura, K.; Nappi, A.; Willis, W.J.; Goldberg, M.; Horwitz, N.; Moneti, G.C.; Lankford, A.J.; Kourkoumelis, C.

    1978-01-01

    The hadronic production of electron pairs with masses between 200 and 500 MeV and large transverse momentum has been measured at the CERN Intersecting Storage Rings (ISR). The expected relation between low-mass electron pairs and real photons is used to determine the direct hadronic production of photons. Contrary to indications from some previous experiments, the observed spectrum is consistent with expectations from the decay of known mesons, and leads to a value for the ratio of direct photons to π 0 of γ/π 0 =(0.55+-0.92)% for 2 = 55 GeV. (Auth.)

  8. INITIAL EXPERIENCE WITH ENDOSCOPIC ULTRASOUND-GUIDED FINE NEEDLE ASPIRATION OF RENAL MASSES: indications, applications and limitations

    Directory of Open Access Journals (Sweden)

    Renata Nobre MOURA

    2014-12-01

    Full Text Available Context Tissue sampling of renal masses is traditionally performed via the percutaneous approach or laparoscopicaly. The utility of endoscopic ultrasound to biopsy renal lesions it remains unclear and few cases have been reported. Objectives To evaluate the feasibility and outcome of endoscopic ultrasound fine needle aspiration of renal tumors. Methods Consecutive subjects undergoing attempted endoscopic ultrasound fine needle aspiration of a kidney mass after evaluation with computerized tomography or magnetic resonance. Results Ten procedures were performed in nine male patients (median age 54.7 years on the right (n = 4 and left kidney (n = 4 and bilaterally (n = 1. Kidney masses (median diameter 55 mm ; range 13-160 mm were located in the upper pole (n = 3, the lower pole (n = 2 and the mesorenal region (n = 3. In two cases, the mass involved more than one kidney region. Surgical resection confirmed renal cell carcinoma in six patients in whom pre-operative endoscopic ultrasound fine needle aspiration demonstrated renal cell carcinoma. No complications were reported. Conclusions Endoscopic ultrasound fine needle aspiration appears as a safe and feasible procedure with good results and minimal morbidity.

  9. Contrasting effects of summer and winter warming on body mass explain population dynamics in a food-limited Arctic herbivore.

    Science.gov (United States)

    Albon, Steve D; Irvine, R Justin; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif E; Ropstad, Erik; Veiberg, Vebjørn; van der Wal, René; Bjørkvoll, Eirin M; Duff, Elizabeth I; Hansen, Brage B; Lee, Aline M; Tveraa, Torkild; Stien, Audun

    2017-04-01

    The cumulative effects of climate warming on herbivore vital rates and population dynamics are hard to predict, given that the expected effects differ between seasons. In the Arctic, warmer summers enhance plant growth which should lead to heavier and more fertile individuals in the autumn. Conversely, warm spells in winter with rainfall (rain-on-snow) can cause 'icing', restricting access to forage, resulting in starvation, lower survival and fecundity. As body condition is a 'barometer' of energy demands relative to energy intake, we explored the causes and consequences of variation in body mass of wild female Svalbard reindeer (Rangifer tarandus platyrhynchus) from 1994 to 2015, a period of marked climate warming. Late winter (April) body mass explained 88% of the between-year variation in population growth rate, because it strongly influenced reproductive loss, and hence subsequent fecundity (92%), as well as survival (94%) and recruitment (93%). Autumn (October) body mass affected ovulation rates but did not affect fecundity. April body mass showed no long-term trend (coefficient of variation, CV = 8.8%) and was higher following warm autumn (October) weather, reflecting delays in winter onset, but most strongly, and negatively, related to 'rain-on-snow' events. October body mass (CV = 2.5%) increased over the study due to higher plant productivity in the increasingly warm summers. Density-dependent mass change suggested competition for resources in both winter and summer but was less pronounced in recent years, despite an increasing population size. While continued climate warming is expected to increase the carrying capacity of the high Arctic tundra, it is also likely to cause more frequent icing events. Our analyses suggest that these contrasting effects may cause larger seasonal fluctuations in body mass and vital rates. Overall our findings provide an important 'missing' mechanistic link in the current understanding of the population biology of a

  10. Characterization of the intragranular water regime within subsurface sediments: pore volume, surface area, and mass transfer limitations

    Science.gov (United States)

    Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

    2011-01-01

    Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ~1% of the solid volume and intragranular surface areas of ~20%–35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

  11. Do we really know Mup (i.e. the transition mass between Type Ia and core-collapse supernova progenitors)?

    International Nuclear Information System (INIS)

    Straniero, O; Piersanti, L; Cristallo, S

    2016-01-01

    M up is the minimum stellar mass that, after the core-helium burning, develops temperature and density conditions for the occurrence of a hydrostatic carbon burning. Stars whose mass is lower than this limit are the progenitors of C-O white dwarfs and, when belong to a close binary system, may give rise to explosive phenomena, such as novae or type Ia supernovae. Stars whose mass is only slightly larger than M up ignite C in a degenerate core and, in turn, experience a thermonuclear runaway. Their final fate may be a massive O-Ne WDs or, if the core mass approaches the Chandrasekhar limit, an e-capture SNe. More massive objects ignite C in non-degenerate conditions. These “massive “ stars are the progenitors of various kind of core-collapse supernovae (type IIp. IIL, IIN, Ib, Ic). It goes without saying that M up is a fundamental astrophysical parameter. From its knowledge depends our understanding of the SNe progenitors, of their rates, of the chemical evolution, of the WD luminosity functions and much more. A precise evaluation of M up relies on our knowledge of various input physics used in stellar modeling, such as the plasma neutrino rate, responsible of the cooling of the core, the equation of state of high density plasma, which affects the heating of the contracting core and its compressibility, and some key nuclear reaction rates, such as, in particular, the 12 C+ 12 C and the 12 C+α. In this paper we review the efforts made to determine this important parameter and we provide an up-to-date evaluation of the uncertainties due to the relevant nuclear physics inputs. (paper)

  12. Hydrodynamic Studies of the Evolution of Recurrent, Symbiotic and Dwarf Novae: the White Dwarf Components are Growing in Mass

    Directory of Open Access Journals (Sweden)

    Starrfield S.

    2012-06-01

    Full Text Available Symbiotic binaries are systems containing white dwarfs (WDs and red giants. Symbiotic novae are those systems in which thermonuclear eruptions occur on the WD components. These are to be distinguished from events driven by accretion disk instabilities analogous to dwarf novae eruptions in cataclysmic variable outbursts. Another class of symbiotic systems are those in which the WD is extremely luminous and it seems likely that quiescent nuclear burning is ongoing on the accreting WD. A fundamental question is the secular evolution of the WD. Do the repeated outbursts or quiescent burning in these accreting systems cause the WD to gain or lose mass? If it is gaining mass, can it eventually reach the Chandrasekhar Limit and become a supernova (a SN Ia if it can hide the hydrogen and helium in the system? In order to better understand these systems, we have begun a new study of the evolution of Thermonuclear Runaways (TNRs in the accreted envelopes of WDs using a variety of initial WD masses, luminosities and mass accretion rates. We use our 1-D hydro code, NOVA, which includes the new convective algorithm of Arnett, Meakin and Young, the Hix and Thielemann nuclear reaction solver, the Iliadis reaction rate library, the Timmes equation of state, and the OPAL opacities. We assume a solar composition (Lodders abundance distribution and do not allow any mixing of accreted material with core material. This assumption strongly influences our results. We report here (1 that the WD grows in mass for all simulations so that ‘steady burning’ does not occur, and (2 that only a small fraction of the accreted matter is ejected in some (but not all simulations. We also find that the accreting systems, before thermonuclear runaway, are too cool to be seen in X-ray searches for SN Ia progenitors.

  13. Limits on a gravitational field dependence of the proton-electron mass ratio from H2 in white dwarf stars.

    Science.gov (United States)

    Bagdonaite, J; Salumbides, E J; Preval, S P; Barstow, M A; Barrow, J D; Murphy, M T; Ubachs, W

    2014-09-19

    Spectra of molecular hydrogen (H2) are employed to search for a possible proton-to-electron mass ratio (μ) dependence on gravity. The Lyman transitions of H2, observed with the Hubble Space Telescope towards white dwarf stars that underwent a gravitational collapse, are compared to accurate laboratory spectra taking into account the high temperature conditions (T∼13 000  K) of their photospheres. We derive sensitivity coefficients Ki which define how the individual H2 transitions shift due to μ dependence. The spectrum of white dwarf star GD133 yields a Δμ/μ constraint of (-2.7±4.7stat±0.2syst)×10(-5) for a local environment of a gravitational potential ϕ∼10(4) ϕEarth, while that of G29-38 yields Δμ/μ=(-5.8±3.8stat±0.3syst)×10(-5) for a potential of 2×10(4) ϕEarth.

  14. Severe obesity is a limitation for the use of body mass index standard deviation scores in children and adolescents.

    Science.gov (United States)

    Júlíusson, Pétur B; Roelants, Mathieu; Benestad, Beate; Lekhal, Samira; Danielsen, Yngvild; Hjelmesaeth, Jøran; Hertel, Jens K

    2018-02-01

    We analysed the distribution of the body mass index standard deviation scores (BMI-SDS) in children and adolescents seeking treatment for severe obesity, according to the International Obesity Task Force (IOTF), World Health Organization (WHO) and the national Norwegian Bergen Growth Study (BGS) BMI reference charts and the percentage above the International Obesity Task Force 25 cut-off (IOTF-25). This was a cross-sectional study of 396 children aged four to 17 years, who attended a tertiary care obesity centre in Norway from 2009 to 2015. Their BMI was converted to SDS using the three growth references and expressed as the percentage above IOTF-25. The percentage of body fat was assessed by bioelectrical impedance analysis. Regardless of which BMI reference chart was used, the BMI-SDS was significantly different between the age groups, with a wider range of higher values up to 10 years of age and a more narrow range of lower values thereafter. The distributions of the percentage above IOTF-25 and percentage of body fat were more consistent across age groups. Our findings suggest that it may be more appropriate to use the percentage above a particular BMI cut-off, such as the percentage above IOTF-25, than the IOTF, WHO and BGS BMI-SDS in paediatric patients with severe obesity. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  15. Determining eligibility for antiretroviral therapy in resource-limited settings using total lymphocyte counts, hemoglobin and body mass index

    Directory of Open Access Journals (Sweden)

    Solberg Peter

    2007-01-01

    Full Text Available Abstract Background CD4+ T lymphocyte (CD4 cell count testing is the standard method for determining eligibility for antiretroviral therapy (ART, but is not widely available in sub-Saharan Africa. Total lymphocyte counts (TLCs have not proven sufficiently accurate in identifying subjects with low CD4 counts. We developed clinical algorithms using TLCs, hemoglobin (Hb, and body mass index (BMI to identify patients who require ART. Methods We conducted a cross-sectional study of HIV-infected adults in Uganda, who presented for assessment for ART-eligibility with WHO clinical stages I, II or III. Two by two tables were constructed to examine TLC thresholds, which maximized sensitivity for CD4 cell counts ≤ 200 cells μL, while minimizing the number offered ART with counts > 350 cells μL. Hb and BMI values were then examined to try to improve model performance. Results 1787 subjects were available for analysis. Median CD4 cell counts and TLCs, were 239 cells/μL and 1830 cells/μL, respectively. Offering ART to all subjects with a TLCs ≤ 2250 cells/μL produced a sensitivity of 0.88 and a false positive ratio of 0.21. Algorithms that treated all patients with a TLC 3000 cells/μL, and used Hb and/or BMI values to determine eligibility for those with TLC values between 2000 and 3000 cells/μL, marginally improved accuracy. Conclusion TLCs appear useful in predicting who would be eligible for ART based on CD4 cell count criteria. Hb and BMI values may be useful in prioritizing patients for ART, but did not improve model accuracy.

  16. Limit on the production of a low-mass vector boson in e+e−→Uγ, U→e+e− with the KLOE experiment

    Directory of Open Access Journals (Sweden)

    A. Anastasi

    2015-11-01

    Full Text Available The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e− collider. Using an integrated luminosity of 1.54 fb−1, we studied the process e+e−→Uγ, with U→e+e−, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ε2, at 10−6–10−4 in the 5–520 MeV/c2 mass range.

  17. Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity.

    Science.gov (United States)

    Ernersson, Asa; Nystrom, Fredrik H; Lindström, Torbjörn

    2010-08-25

    A sedentary lifestyle and increased consumption of energy dense food have become more common in many parts of the world. The aim of this study was to study long term effects on body composition after a four week intervention with fast food based hyper-alimentation and limited physical activity in young normal weight subjects. Eighteen subjects, mean age 26 (6.6) years, increased their energy intake with in average 70% and physical activity were not to exceed 5000 steps/day. Body composition was measured by Dual energy x-ray (DXA) at baseline, after the intervention and after 12 months. A matched control group was also included. ANOVA and Student's paired and unpaired t-test were used. During the intervention body weight increased with 6.4 (2.8) kg and DXA measurements showed increases of both fat free mass and fat mass. Six months after the intervention the subjects had lost most of the weight gain, - 4.7 (3.1) kg. Twelve months after the intervention body weight had increased with 1.5 (2.4) kg compared to baseline (p = 0.018). DXA measurements at 12 months showed unchanged fat free mass compared to baseline but higher fat mass, + 1.4 (1.9) kg (p = 0.01). After 2.5 years the increase of body weight was 3.1 (4.0) kg (p = 0.01) while there was no change in controls compared to baseline, + 0.1(2.5) kg (p = 0.88). One year after a short term intervention with increased fast food based hyper-alimentation there was an increase of fat mass but unchanged fat free mass. As the change of fat mass was larger than expected from prospective epidemiological studies and as there was no increase of body weight in controls it raises the issue whether there is a long-term effect to increase fat mass of a short period of hyper-alimentation.

  18. Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity

    Directory of Open Access Journals (Sweden)

    Ernersson Åsa

    2010-08-01

    Full Text Available Abstract Background A sedentary lifestyle and increased consumption of energy dense food have become more common in many parts of the world. The aim of this study was to study long term effects on body composition after a four week intervention with fast food based hyper-alimentation and limited physical activity in young normal weight subjects. Methods Eighteen subjects, mean age 26 (6.6 years, increased their energy intake with in average 70% and physical activity were not to exceed 5000 steps/day. Body composition was measured by Dual energy x-ray (DXA at baseline, after the intervention and after 12 months. A matched control group was also included. ANOVA and Student's paired and unpaired t-test were used. Results During the intervention body weight increased with 6.4 (2.8 kg and DXA measurements showed increases of both fat free mass and fat mass. Six months after the intervention the subjects had lost most of the weight gain, - 4.7 (3.1 kg. Twelve months after the intervention body weight had increased with 1.5 (2.4 kg compared to baseline (p = 0.018. DXA measurements at 12 months showed unchanged fat free mass compared to baseline but higher fat mass, + 1.4 (1.9 kg (p = 0.01. After 2.5 years the increase of body weight was 3.1 (4.0 kg (p = 0.01 while there was no change in controls compared to baseline, + 0.1(2.5 kg (p = 0.88. Conclusion One year after a short term intervention with increased fast food based hyper-alimentation there was an increase of fat mass but unchanged fat free mass. As the change of fat mass was larger than expected from prospective epidemiological studies and as there was no increase of body weight in controls it raises the issue whether there is a long-term effect to increase fat mass of a short period of hyper-alimentation.

  19. The Legacy of S Chandrasekhar

    Indian Academy of Sciences (India)

    broader perspective of a life devoted to science. It is from this broader perspective that I want to reflect upon Chandra's life in this article. ... He wrapped up his findings in a monograph, his first book titled, An .... During the second world war, he.

  20. Properties of the Higgs boson in the 4 leptons final state with the ATLAS experiment at the LHC: mass, limit on the high mass contribution and on the Higgs width

    International Nuclear Information System (INIS)

    Calandri, Alessandro

    2015-01-01

    The theme of the analyses presented in this Thesis is the measurement of the Higgs boson properties in the H→ZZ→4l decay channel with the ATLAS experiment at the LHC. A detailed overview on the electron calibration process is first presented. In this regard, the track-cluster combination algorithm is found to improve the energy resolution of low ET electrons by exploiting both track and cluster information into a maximum likelihood fit. The improvement in resolution is approximately 18-20% for J/ψ dielectron decays, and of the order of 3% for Z→ee events. In addition, the E-p combination algorithm has also been applied to the H→ZZ→4l channel with electrons in the final state resulting in a non-negligible gain on the invariant mass distribution (4-5%). Secondly, the Higgs mass and its total width are evaluated in the H→ZZ→4l channel. The Higgs mass is measured in the 4l decay channel with particular interest on the beneficial effects brought by the improved electron calibration and the track-cluster combination. The mass on the full 2011 and 2012 datasets is worked out with a 2-dimensional fit on the invariant mass of the 4 lepton final state, m4l, and on a boosted decision tree (BDT)-based output conceived against the main ZZ irreducible background and constructed on variables that are sensitive to the Higgs boson spin-parity state. Regarding the Higgs width, results are based on a relatively recent approach aimed at indirectly constraining the Higgs boson width by exploiting the m4l high-mass region where the Higgs boson acts as a propagator. The Higgs production cross section in the on-shell m4l region, where the Higgs boson is a resonance, depends on the total Higgs width, whereas this is not the case for the high mass m4l (off-shell). Limits on the Higgs width can be therefore set when merging the off-shell results with the on-shell ones. A limit of 6.7 times ΓSMH is obtained in the four lepton channel. Secondly, by combining with the on

  1. Contributions of Function-Altering Variants in Genes Implicated in Pubertal Timing and Body Mass for Self-Limited Delayed Puberty.

    Science.gov (United States)

    Howard, Sasha R; Guasti, Leonardo; Poliandri, Ariel; David, Alessia; Cabrera, Claudia P; Barnes, Michael R; Wehkalampi, Karoliina; O'Rahilly, Stephen; Aiken, Catherine E; Coll, Anthony P; Ma, Marcella; Rimmington, Debra; Yeo, Giles S H; Dunkel, Leo

    2018-02-01

    Self-limited delayed puberty (DP) is often associated with a delay in physical maturation, but although highly heritable the causal genetic factors remain elusive. Genome-wide association studies of the timing of puberty have identified multiple loci for age at menarche in females and voice break in males, particularly in pathways controlling energy balance. We sought to assess the contribution of rare variants in such genes to the phenotype of familial DP. We performed whole-exome sequencing in 67 pedigrees (125 individuals with DP and 35 unaffected controls) from our unique cohort of familial self-limited DP. Using a whole-exome sequencing filtering pipeline one candidate gene [fat mass and obesity-associated gene (FTO)] was identified. In silico, in vitro, and mouse model studies were performed to investigate the pathogenicity of FTO variants and timing of puberty in FTO+/- mice. We identified potentially pathogenic, rare variants in genes in linkage disequilibrium with genome-wide association studies of age at menarche loci in 283 genes. Of these, five genes were implicated in the control of body mass. After filtering for segregation with trait, one candidate, FTO, was retained. Two FTO variants, found in 14 affected individuals from three families, were also associated with leanness in these patients with DP. One variant (p.Leu44Val) demonstrated altered demethylation activity of the mutant protein in vitro. Fto+/- mice displayed a significantly delayed timing of pubertal onset (P puberty in the general population may contribute to the pathogenesis of self-limited DP. Copyright © 2017 Endocrine Society

  2. Controlling the properties of ultraintense laser-proton sources using transverse refluxing of hot electrons in shaped mass-limited targets

    International Nuclear Information System (INIS)

    Tresca, O; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Gray, R J; Quinn, M N; McKenna, P; Aurand, B; Bagnoud, V; Fils, J; Kuehl, T; Zielbauer, B; Li, C; Li, Y T; Lin, X X; Evans, R G; Roth, M; Neely, D

    2011-01-01

    We report on the transverse refluxing of energetic electrons in mass-limited foil targets irradiated with high intensity (1 x 10 19 W cm -2 ), picosecond laser pulses. It is shown experimentally that the maximum energies of protons accelerated by sheath fields formed at the rear and at the edges of the target increase with decreasing target size. This is due to the modification of the sheath field by the energetic electrons which spread laterally along the target surface and reflect from the edges. In addition, it is shown that this transverse refluxing of energetic electrons can be used to tailor the spatial-intensity distribution of the proton beam by engineering the shape and size of the target.

  3. Controlling the properties of ultraintense laser-proton sources using transverse refluxing of hot electrons in shaped mass-limited targets

    Energy Technology Data Exchange (ETDEWEB)

    Tresca, O; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Gray, R J; Quinn, M N; McKenna, P [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Aurand, B; Bagnoud, V; Fils, J; Kuehl, T; Zielbauer, B [PHELIX Department, GSI mbH, 64291 Darmstadt (Germany); Li, C; Li, Y T; Lin, X X [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Evans, R G [Plasma Physics Group, Blackett Laboratory, Imperial College, London, SW7 2AZ (United Kingdom); Roth, M [Technical University of Darmstadt, 64289 Darmstadt (Germany); Neely, D, E-mail: paul.mckenna@strath.ac.uk [STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom)

    2011-10-15

    We report on the transverse refluxing of energetic electrons in mass-limited foil targets irradiated with high intensity (1 x 10{sup 19} W cm{sup -2}), picosecond laser pulses. It is shown experimentally that the maximum energies of protons accelerated by sheath fields formed at the rear and at the edges of the target increase with decreasing target size. This is due to the modification of the sheath field by the energetic electrons which spread laterally along the target surface and reflect from the edges. In addition, it is shown that this transverse refluxing of energetic electrons can be used to tailor the spatial-intensity distribution of the proton beam by engineering the shape and size of the target.

  4. Combined Tevatron upper limit on gg -> H -> W^+W^- and constraints on the Higgs boson mass in fourth-generation fermion models

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Adelman, J.; Aguilo, E.; Alexeev, G.D.; Alkhazov, G.; /Helsinki Inst. of Phys. /Dubna, JINR /Oklahoma U. /Michigan State U. /Tata Inst. /Illinois U., Chicago /Florida State U. /Chicago U., EFI /Simon Fraser U. /York U., Canada /St. Petersburg, INP /Illinois U., Urbana /Sao Paulo, IFT /Munich U. /University Coll. London /Oxford U. /St. Petersburg, INP /Duke U. /Kyungpook Natl. U. /Chonnam Natl. U. /Florida U. /Osaka City U.

    2010-05-01

    We combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg {yields} H {yields} W{sup +}W{sup -} in p{bar p} collisions at the Fermilab Tevatron Collider at {radical}s = 1.o6 TeV. With 4.8 fb{sup -1} of itnegrated luminosity analyzed at CDF and 5.4 fb{sup -1} at D0, the 95% Confidence Level upper limit on {sigma}(gg {yields} H) x {Beta}(H {yields} W{sup +}W{sup -}) is 1.75 pb at m{sub H} = 120 GeV, 0.38 pb at m{sub H} = 165 GeV, and 0.83 pb at m{sub H} = 200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, they exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass between 131 and 204 Gev.

  5. The White Dwarf Mass and the Accretion Rate of Recurrent Novae: An X-ray Perspective

    Science.gov (United States)

    Mukai, Koji; Sokoloski, Jennifer L.; Nelson, Thomas; Luna, Gerardo J. M.

    2011-01-01

    We present recent results of quiescent X-ray observations of recurrent novae (RNe) and related objects. Several RNe are luminous hard X-ray sources in quiescence, consistent with accretion onto a near Chandrasekhar mass white dwarf. Detection of similar hard X-ray emissions in old novae and other cataclysmic variables may lead to identification of additional RN candidates. On the other hand, other RNe are found to be comparatively hard X-ray faint. We present several scenarios that may explain this dichotomy, which should be explored further.

  6. UPPER LIMITS ON THE MASSES OF 105 SUPERMASSIVE BLACK HOLES FROM HUBBLE SPACE TELESCOPE/SPACE TELESCOPE IMAGING SPECTROGRAPH ARCHIVAL DATA

    International Nuclear Information System (INIS)

    Beifiori, A.; Corsini, E. M.; Bonta, E. Dalla; Pizzella, A.; Coccato, L.; Bertola, F.; Sarzi, M.

    2009-01-01

    Based on the modeling of the central emission-line width measured over subarcsecond apertures with the Hubble Space Telescope, we present stringent upper bounds on the mass of the central supermassive black hole, M . , for a sample of 105 nearby galaxies (D c (58-419 km s -1 ). For the vast majority of the objects, the derived M . upper limits run parallel and above the well-known M . -σ c relation independently of the galaxy distance, suggesting that our nebular line-width measurements trace rather well the nuclear gravitational potential. For values of σ c between 90 and 220 km s -1 , 68% of our upper limits falls immediately above the M . -σ c relation without exceeding the expected M . values by more than a factor 4.1. No systematic trends or offsets are observed in this σ c range as a function of the galaxy Hubble type or with respect to the presence of a bar. For 6 of our 12 M . upper limits with σ c -1 , our line-width measurements are more sensitive to the stellar contribution to the gravitational potential, either due to the presence of a nuclear stellar cluster or because of a greater distance compared to the other galaxies at the low-σ c end of the M . -σ c relation. Conversely, our M . upper bounds appear to lie closer to the expected M . in the most massive elliptical galaxies with values of σ c above 220 km s -1 . Such a flattening of the M . -σ c relation at its high-σ c end would appear consistent with a coevolution of supermassive black holes and galaxies driven by dry mergers, although better and more consistent measurements for σ c and K-band luminosity are needed for these kinds of objects before systematic effects can be ruled out.

  7. The accretion of solar material onto white dwarfs: No mixing with core material implies that the mass of the white dwarf is increasing

    Directory of Open Access Journals (Sweden)

    Sumner Starrfield

    2014-02-01

    Full Text Available Cataclysmic Variables (CVs are close binary star systems with one component a white dwarf (WD and the other a larger cooler star that fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and some unknown fraction of this material is accreted by the WD. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia explosion and is designated the Single Degenerate Progenitor (SD scenario. This paper is concerned with the SD scenario for SN Ia progenitors. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen CO core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova explosion. Both observations and theoretical studies of these explosions imply that more mass is ejected than is accreted. Thus, the WD in a Classical Nova system is losing mass and cannot be a SN Ia progenitor. However, the composition in the nuclear burning region is important and, in new calculations reported here, the consequences to the WD of no mixing of accreted material with core material have been investigated so that the material involved in the explosion has only a Solar composition. WDs with a large range in initial masses and mass accretion rates have been evolved. I find that once sufficient material has been accreted, nuclear burning occurs in all evolutionary sequences and continues until a thermonuclear runaway (TNR occurs and the WD either ejects a small amount of material or its radius grows to about 1012 cm and the evolution is ended. In all cases where mass ejection occurs

  8. Linking chloride mass balance infiltration rates with chlorofluorocarbon and SF6 groundwater dating in semi-arid settings: potential and limitations.

    Science.gov (United States)

    Stadler, Susanne; Osenbruck, Karsten; Duijnisveld, Wilhelmus H M; Schwiede, Martin; Bottcher, Jurgen

    2010-09-01

    In the framework of the investigation of enrichment processes of nitrate in groundwater of the Kalahari of Botswana near Serowe, recharge processes were investigated. The thick unsaturated zone extending to up to 100 m of mostly unconsolidated sediments and very low recharge rates pose a serious challenge to study solute transport related to infiltration and recharge processes, as this extends past the conventional depths of soil scientific investigations and is difficult to describe using evidence from the groundwater due to the limitations imposed by available tracers. To determine the link between nitrate in the vadose zone and in the uppermost groundwater, sediment from the vadose zone was sampled up to a depth of 15-20 m (in one case also to 65 m) on several sites with natural vegetation in the research area. Among other parameters, sediment and water were analysed to determine chloride and nitrate concentration depth profiles. Using the chloride mass balance method, an estimation of groundwater infiltration rates produced values of 0.2-4 mm a(-1). The uncertainty of these values is, however, high. Because of the extreme thickness of the vadose zone, the travel time in the unsaturated zone might reach extreme values of up to 500 years and more. For investigations using groundwater, we applied the chlorofluorocarbons CFC-113, CFC-12, sulphur hexafluoride (SF(6)) and tritium to identify potential recharge, and found indications for some advective transport of the CFCs and SF(6), which we accounted for as constituting potential active localised recharge. In our contribution, we show the potential and limitations of the applied methods to determine groundwater recharge and coupled solute transport in semi-arid settings, and compare travel time ranges derived from soil science and groundwater investigations.

  9. A Simple Approach for Obtaining High Resolution, High Sensitivity ¹H NMR Metabolite Spectra of Biofluids with Limited Mass Supply

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Zhi; Rommereim, Donald N.; Wind, Robert A.; Minard, Kevin R.; Sears, Jesse A.

    2006-11-01

    A simple approach is reported that yields high resolution, high sensitivity ¹H NMR spectra of biofluids with limited mass supply. This is achieved by spinning a capillary sample tube containing a biofluid at the magic angle at a frequency of about 80Hz. A 2D pulse sequence called ¹H PASS is then used to produce a high-resolution ¹H NMR spectrum that is free from magnetic susceptibility induced line broadening. With this new approach a high resolution ¹H NMR spectrum of biofluids with a volume less than 1.0 µl can be easily achieved at a magnetic field strength as low as 7.05T. Furthermore, the methodology facilitates easy sample handling, i.e., the samples can be directly collected into inexpensive and disposable capillary tubes at the site of collection and subsequently used for NMR measurements. In addition, slow magic angle spinning improves magnetic field shimming and is especially suitable for high throughput investigations. In this paper first results are shown obtained in a magnetic field of 7.05T on urine samples collected from mice using a modified commercial NMR probe.

  10. Precision Timing of PSR J0437-4715: An Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton's Gravitational Constant

    Science.gov (United States)

    Verbiest, J. P. W.; Bailes, M.; van Straten, W.; Hobbs, G. B.; Edwards, R. T.; Manchester, R. N.; Bhat, N. D. R.; Sarkissian, J. M.; Jacoby, B. A.; Kulkarni, S. R.

    2008-05-01

    Analysis of 10 years of high-precision timing data on the millisecond pulsar PSR J0437-4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, dot Pb , determined at the 1.5% level of precision (Dk = 157.0 +/- 2.4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy between this measurement and a previously published parallax distance estimate is attributed to errors in the DE200 solar system ephemerides. The precise measurement of dot Pb allows a limit on the variation of Newton's gravitational constant, |Ġ/G| <= 23 × 10-12 yr-1. We also constrain any anomalous acceleration along the line of sight to the pulsar to |a⊙/c| <= 1.5 × 10-18 s-1 at 95% confidence, and derive a pulsar mass, mpsr = 1.76 +/- 0.20 M⊙, one of the highest estimates so far obtained.

  11. Low skeletal muscle mass is a predictive factor for chemotherapy dose-limiting toxicity in patients with locally advanced head and neck cancer.

    Science.gov (United States)

    Wendrich, Anne W; Swartz, Justin E; Bril, Sandra I; Wegner, Inge; de Graeff, Alexander; Smid, Ernst J; de Bree, Remco; Pothen, Ajit J

    2017-08-01

    Low skeletal muscle mass (SMM) or sarcopenia is emerging as an adverse prognostic factor for chemotherapy dose-limiting toxicity (CLDT) and survival in cancer patients. Our aim was to determine the impact of low SMM on CDLT in patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC) treated with primary radiochemotherapy (RCT). Consecutive patients diagnosed with LA-HNSCC and treated with primary RCT between 2007 and 2011 in our center were included. Clinical variables were retrospectively retrieved and SMM was measured at the level of the third cervical vertebra using pre-treatment head and neck CT-scans. After determining a cut-off value for low SMM, multivariate analysis was performed to identify prognostic factors for CDLT. Of 112 patients included, 30.4% experienced CDLT. The optimal cut-off value for low SMM as a predictor of CDLT was ≤43.2cm 2 /m 2 . Using this cut-off, 54.5% patients had low SMM. Patients with low SMM experienced CDLT more frequently than patients with normal SMM (44.3% vs. 13.7%, pSMM, p=0.044). At multivariate analysis, low SMM was independently inversely associated with CDLT (OR 0.93, 95%CI: 0.88-0.98). Patients experiencing CDLT had a lower overall survival than patients who did not (mean 36.6vs. 54.2months, p=0.038). Low SMM is an independent risk factor for CDLT in LA-HNSCC patients treated with primary RCT. Pre-therapeutic estimation of SMM using routine CT-scans of the head and neck region may identify patients at risk of CDLT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Lean body mass as an independent determinant of dose-limiting toxicity and neuropathy in patients with colon cancer treated with FOLFOX regimens

    International Nuclear Information System (INIS)

    Ali, Raafi; Sawyer, Michael B.; Bianchi, Laurent; Roberts, Sarah; Mollevi, Caroline; Senesse, Pierre; Baracos, Vickie E.; Assenat, Eric

    2016-01-01

    Evidence suggests that lean body mass (LBM) may be useful to normalize chemotherapy doses. Data from one prospective and one retrospective study were used to determine if the highest doses of oxaliplatin/kg LBM within FOLFOX regimens would be associated with dose-limiting toxicity (DLT) in colon cancer patients. Toxicity over four cycles was graded according to NCI Common Toxicity Criteria V2 or V3 (Common Terminology Criteria for Adverse Events, National Cancer Institute, Bethesda, MD). Muscle tissue was measured by computerized tomography (CT) and used to evaluate the LBM compartment of the whole body. In prospective randomized clinical trials conducted in France (n = 58), for patients given FOLFOX-based regimens according to body surface area, values of oxaliplatin/kg LBM were highly variable, ranging from 2.55 to 6.6 mg/kg LBM. A cut point of 3.09 mg oxaliplatin/kg LBM for developing toxicity was determined by Receiver Operating Characteristic (ROC) analysis, below this value 0/17 (0.0%) of patients experienced DLT; in contrast above this value 18/41 (44.0%) of patients were dose reduced or had treatment terminated owing to toxicity (≥Grade 3 or neuropathy ≥Grade 2); for 9/41 the DLT was sensory neuropathy. These findings were validated in an independent cohort of colon cancer patients (n = 80) receiving FOLFOX regimens as part of standard care, in Canada. Low LBM is a significant predictor of toxicity and neuropathy in patients administered FOLFOX-based regimens using conventional body surface area (BSA) dosing

  13. Unconventional application of the two-flux approximation for the calculation of the Ambartsumyan-Chandrasekhar function and the angular spectrum of the backward-scattered radiation for a semi-infinite isotropically scattering medium

    Science.gov (United States)

    Remizovich, V. S.

    2010-06-01

    It is commonly accepted that the Schwarzschild-Schuster two-flux approximation (1905, 1914) can be employed only for the calculation of the energy characteristics of the radiation field (energy density and energy flux density) and cannot be used to characterize the angular distribution of radiation field. However, such an inference is not valid. In several cases, one can calculate the radiation intensity inside matter and the reflected radiation with the aid of this simplest approximation in the transport theory. In this work, we use the results of the simplest one-parameter variant of the two-flux approximation to calculate the angular distribution (reflection function) of the radiation reflected by a semi-infinite isotropically scattering dissipative medium when a relatively broad beam is incident on the medium at an arbitrary angle relative to the surface. We do not employ the invariance principle and demonstrate that the reflection function exhibits the multiplicative property. It can be represented as a product of three functions: the reflection function corresponding to the single scattering and two identical h functions, which have the same physical meaning as the Ambartsumyan-Chandrasekhar function ( H) has. This circumstance allows a relatively easy derivation of simple analytical expressions for the H function, total reflectance, and reflection function. We can easily determine the relative contribution of the true single scattering in the photon backscattering at an arbitrary probability of photon survival Λ. We compare all of the parameters of the backscattered radiation with the data resulting from the calculations using the exact theory of Ambartsumyan, Chandrasekhar, et al., which was developed decades after the two-flux approximation. Thus, we avoid the application of fine mathematical methods (the Wiener-Hopf method, the Case method of singular functions, etc.) and obtain simple analytical expressions for the parameters of the scattered radiation

  14. An upper limit on the contribution of accreting white dwarfs to the type Ia supernova rate.

    Science.gov (United States)

    Gilfanov, Marat; Bogdán, Akos

    2010-02-18

    There is wide agreement that type Ia supernovae (used as standard candles for cosmology) are associated with the thermonuclear explosions of white dwarf stars. The nuclear runaway that leads to the explosion could start in a white dwarf gradually accumulating matter from a companion star until it reaches the Chandrasekhar limit, or could be triggered by the merger of two white dwarfs in a compact binary system. The X-ray signatures of these two possible paths are very different. Whereas no strong electromagnetic emission is expected in the merger scenario until shortly before the supernova, the white dwarf accreting material from the normal star becomes a source of copious X-rays for about 10(7) years before the explosion. This offers a means of determining which path dominates. Here we report that the observed X-ray flux from six nearby elliptical galaxies and galaxy bulges is a factor of approximately 30-50 less than predicted in the accretion scenario, based upon an estimate of the supernova rate from their K-band luminosities. We conclude that no more than about five per cent of type Ia supernovae in early-type galaxies can be produced by white dwarfs in accreting binary systems, unless their progenitors are much younger than the bulk of the stellar population in these galaxies, or explosions of sub-Chandrasekhar white dwarfs make a significant contribution to the supernova rate.

  15. Limited Access to Food and Physiological Trade-Offs in a Long-Distance Migrant Shorebird. I. Energy Metabolism, Behavior, and Body-Mass Regulation

    NARCIS (Netherlands)

    Vezina, Francois; Petit, Magali; Buehler, Deborah M.; Dekinga, Anne; Piersma, Theunis

    2009-01-01

    Previous experiments showed reduction of basal metabolic rate (BMR) in birds facing energetic challenges. We alternately exposed two groups of red knots (Calidris canutus) to either 6 h or 22 h of food availability for periods of 22 d. Six h of access to food led to a 6%-10% loss of body mass over

  16. Efficacy of whey protein supplementation on resistance exercise-induced changes in muscle strength, lean mass, and function in mobility-limited older adults

    Science.gov (United States)

    Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to functionally compromised older adults. The objectives of the study were to compare the effects of whey protein concent...

  17. ASTROMETRY AND RADIAL VELOCITIES OF THE PLANET HOST M DWARF GJ 317: NEW TRIGONOMETRIC DISTANCE, METALLICITY, AND UPPER LIMIT TO THE MASS OF GJ 317b

    International Nuclear Information System (INIS)

    Anglada-Escudé, Guillem; Boss, Alan P.; Weinberger, Alycia J.; Butler, R. Paul; Thompson, Ian B.; Vogt, Steven S.; Rivera, Eugenio J.

    2012-01-01

    We have obtained precision astrometry of the planet host M dwarf GJ 317 in the framework of the Carnegie Astrometric Planet Search project. The new astrometric measurements give a distance determination of 15.3 pc, 65% further than previous estimates. The resulting absolute magnitudes suggest that it is metal-rich and more massive than previously assumed. This result strengthens the correlation between high metallicity and the presence of gas giants around low-mass stars. At 15.3 pc, the minimal astrometric amplitude for planet candidate GJ 317b is 0.3 mas (edge-on orbit), just below our astrometric sensitivity. However, given the relatively large number of observations and good astrometric precision, a Bayesian Monte Carlo Markov Chain analysis indicates that the mass of planet b has to be smaller than twice the minimum mass with a 99% confidence level, with a most likely value of 2.5 M Jup . Additional radial velocity (RV) measurements obtained with Keck by the Lick-Carnegie Planet search program confirm the presence of an additional very long period planet candidate, with a period of 20 years or more. Even though such an object will imprint a large astrometric wobble on the star, its curvature is yet not evident in the astrometry. Given high metallicity, and the trend indicating that multiple systems are rich in low-mass companions, this system is likely to host additional low-mass planets in its habitable zone that can be readily detected with state-of-the-art optical and near-infrared RV measurements.

  18. ASTROMETRY AND RADIAL VELOCITIES OF THE PLANET HOST M DWARF GJ 317: NEW TRIGONOMETRIC DISTANCE, METALLICITY, AND UPPER LIMIT TO THE MASS OF GJ 317b

    Energy Technology Data Exchange (ETDEWEB)

    Anglada-Escude, Guillem; Boss, Alan P.; Weinberger, Alycia J.; Butler, R. Paul [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Thompson, Ian B. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Vogt, Steven S.; Rivera, Eugenio J., E-mail: anglada@dtm.ciw.edu [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)

    2012-02-10

    We have obtained precision astrometry of the planet host M dwarf GJ 317 in the framework of the Carnegie Astrometric Planet Search project. The new astrometric measurements give a distance determination of 15.3 pc, 65% further than previous estimates. The resulting absolute magnitudes suggest that it is metal-rich and more massive than previously assumed. This result strengthens the correlation between high metallicity and the presence of gas giants around low-mass stars. At 15.3 pc, the minimal astrometric amplitude for planet candidate GJ 317b is 0.3 mas (edge-on orbit), just below our astrometric sensitivity. However, given the relatively large number of observations and good astrometric precision, a Bayesian Monte Carlo Markov Chain analysis indicates that the mass of planet b has to be smaller than twice the minimum mass with a 99% confidence level, with a most likely value of 2.5 M{sub Jup}. Additional radial velocity (RV) measurements obtained with Keck by the Lick-Carnegie Planet search program confirm the presence of an additional very long period planet candidate, with a period of 20 years or more. Even though such an object will imprint a large astrometric wobble on the star, its curvature is yet not evident in the astrometry. Given high metallicity, and the trend indicating that multiple systems are rich in low-mass companions, this system is likely to host additional low-mass planets in its habitable zone that can be readily detected with state-of-the-art optical and near-infrared RV measurements.

  19. Multiple analyte adduct formation in liquid chromatography-tandem mass spectrometry - Advantages and limitations in the analysis of biologically-related samples.

    Science.gov (United States)

    Dziadosz, Marek

    2018-05-01

    Multiple analyte adduct formation was examined and discussed in the context of reproducible signal detection in liquid chromatography-tandem mass spectrometry applied in the analysis of biologically-related samples. Appropriate infusion solutions were prepared in H 2 O/methanol (3/97, v/v) with 1 mM sodium acetate and 10 mM acetic acid. An API 4000 QTrap tandem mass spectrometer was used for experiments performed in the negative scan mode (-Q1 MS) and the negative enhanced product ion mode (-EPI). γ‑Hydroxybutyrate and its deuterated form were used as model compounds to highlight both the complexity of adduct formation in popular mobile phases used and the effective signal compensation by the application of isotope-labelled analytes as internal standards. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis

    Czech Academy of Sciences Publication Activity Database

    Španěl, Patrik; Dryahina, Kseniya; Smith, D.

    2007-01-01

    Roč. 267, 1-3 (2007), s. 117-124 ISSN 1387-3806 R&D Projects: GA ČR GA202/06/0776 Institutional research plan: CEZ:AV0Z40400503 Keywords : microwave plasma ion source * selected ion flow tube mass spectrometry * SIFT-MS * breath analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.411, year: 2007

  1. Exploring the supersymmetric U(1 ) B -L×U(1 ) R model with dark matter, muon g - 2 , and Z' mass limits

    Science.gov (United States)

    Frank, Mariana; Özdal, Özer

    2018-01-01

    We study the low scale predictions of the supersymmetric standard model extended by U (1 )B -L×U (1 )R symmetry, obtained from S O (10 ) breaking via a left-right supersymmetric model, imposing universal boundary conditions. Two singlet Higgs fields are responsible for the radiative U (1 )B -L×U (1 )R symmetry breaking, and a singlet fermion S is introduced to generate neutrino masses through an inverse seesaw mechanism. The lightest neutralino or sneutrino emerge as dark matter candidates, with different low scale implications. We find that the composition of the neutralino lightest supersymmetric particle (LSP) changes considerably depending on the neutralino LSP mass, from roughly half U (1 )R bino, half minimal supersymmetric model (MSSM) bino, to a singlet higgsino, or completely dominated by the MSSM higgsino. The sneutrino LSP is statistically much less likely, and when it occurs it is a 50-50 mixture of right-handed sneutrino and the scalar S ˜. Most of the solutions consistent with the relic density constraint survive the XENON 1T exclusion curve for both LSP cases. We compare the two scenarios and investigate parameter space points and find consistency with the muon anomalous magnetic moment only at the edge of a 2 σ deviation from the measured value. However, we find that the sneutrino LSP solutions could be ruled out completely by the strict reinforcement of the recent Z' mass bounds. We finally discuss collider prospects for testing the model.

  2. Properties of the Higgs boson in the 4 lepton final state at the LHC with the ATLAS experiment: mass, limits on the high mass contribution and on the total width

    CERN Document Server

    AUTHOR|(SzGeCERN)719049

    The theme of the analyses presented in this Thesis is the measurement of the Higgs boson properties in the H$\\rightarrow$ZZ$\\rightarrow$4l decay channel with the ATLAS experiment at the LHC. A detailed overview on the electron calibration process is first presented. In this regard, the track-cluster combination algorithm is found to improve the energy resolution of low $E_{T}$ electrons by exploiting both track and cluster information into a maximum likelihood fit. The improvement in resolution is approximately 18-20% for J/$\\Psi$ dielectron decays, and of the order of 3% for Z$\\rightarrow$ee events. In addition, the E-p combination algorithm has also been applied to the H$\\rightarrow$ZZ$\\rightarrow$4l channel with electrons in the final state resulting in a non-negligible gain on the invariant mass distribution (4-5%). Secondly, the Higgs mass and its total width are evaluated in the H$\\rightarrow$ZZ$\\rightarrow$4l channel. The Higgs mass is measured in the 4l decay channel with particular interest on the be...

  3. 2D elemental mapping of sections of human kidney stones using laser ablation inductively-coupled plasma-mass spectrometry: Possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Vašinová Galiová, Michaela [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Čopjaková, Renata; Škoda, Radek [Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Štěpánková, Kateřina; Vaňková, Michaela [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Kuta, Jan [Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University, Kamenice 126/3, 625 00 Brno (Czech Republic); Prokeš, Lubomír [Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Kynický, Jindřich [Department of Pedology and Geology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno (Czech Republic); and others

    2014-10-01

    A 213 nm Nd:YAG-based laser ablation (LA) system coupled to quadrupole-based inductively coupled plasma-mass spectrometer and an ArF* excimer-based LA-system coupled to a double-focusing sector field inductively coupled plasma-mass spectrometer were employed to study the spatial distribution of various elements in kidney stones (uroliths). Sections of the surfaces of uroliths were ablated according to line patterns to investigate the elemental profiles for the different urolith growth zones. This exploratory study was mainly focused on the distinguishing of the main constituents of urinary calculus fragments by means of LA-ICP-mass spectrometry. Changes in the ablation rate for oxalate and phosphate phases related to matrix density and hardness are discussed. Elemental association was investigated on the basis of 2D mapping. The possibility of using NIST SRM 1486 Bone Meal as an external standard for calibration was tested. It is shown that LA-ICP-MS is helpful for determination of the mineralogical composition and size of all phases within the analyzed surface area, for tracing down elemental associations and for documenting the elemental content of urinary stones. LA-ICP-MS results (elemental contents and maps) are compared to those obtained with electron microprobe analysis and solution analysis ICP-MS. - Highlights: • Elements in phosphate and oxalate urolith phases were quantified by LA-ICP-MS. • SRM NIST 1486 Bone Meal was proved suitable for quantification in uroliths. • Different ablation rates in particular phases were included at quantification. • Oxalate and apatite phases show opposite hardness order to natural minerals. • Uroliths were classified according to elemental association to phases.

  4. Fourier Transform Mass Spectrometry.

    Science.gov (United States)

    Gross, Michael L.; Rempel, Don L.

    1984-01-01

    Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

  5. An isotope dilution gas chromatography/mass spectrometry method for trace analysis of xylene and its metabolites in tissues following threshold limit value exposures

    Energy Technology Data Exchange (ETDEWEB)

    Pyon, K.H.; Kracko, D.A.; Strunk, M.R. [and others

    1995-12-01

    The existence of a nose-brain barrier that functions to protect the central nervous system (CNS) from inhaled toxicants has been postulated. Just as a blood-brain barrier protects the CNS from systemic toxicants, the nose-brain barrier may have similar characteristic functions. One component of interest is nasal xenobiotic metabolism and its effect on the transport of pollutants into the CNS at environmentally plausible levels of exposure. Previous results have shown that inhaled xylene are dimethyl phenol (DMP) and methyl benzyl alcohol (MBA), and the nonvolatile metabolites are toluic acid (TA) and methyl hippuric acid (MHA). The nonvolatile metabolites of xylene, along with a small quantity of volatiles, representing either parent xylene or volatile metabolites, are transported via the olfactory epithelium to the glomeruli within the olfactory bulbs of the brain. Further work will be done to establish the linearity for each analyte at the actual highest detection limit of the GC/MS.

  6. An isotope dilution gas chromatography/mass spectrometry method for trace analysis of xylene and its metabolites in tissues following threshold limit value exposures

    International Nuclear Information System (INIS)

    Pyon, K.H.; Kracko, D.A.; Strunk, M.R.

    1995-01-01

    The existence of a nose-brain barrier that functions to protect the central nervous system (CNS) from inhaled toxicants has been postulated. Just as a blood-brain barrier protects the CNS from systemic toxicants, the nose-brain barrier may have similar characteristic functions. One component of interest is nasal xenobiotic metabolism and its effect on the transport of pollutants into the CNS at environmentally plausible levels of exposure. Previous results have shown that inhaled xylene are dimethyl phenol (DMP) and methyl benzyl alcohol (MBA), and the nonvolatile metabolites are toluic acid (TA) and methyl hippuric acid (MHA). The nonvolatile metabolites of xylene, along with a small quantity of volatiles, representing either parent xylene or volatile metabolites, are transported via the olfactory epithelium to the glomeruli within the olfactory bulbs of the brain. Further work will be done to establish the linearity for each analyte at the actual highest detection limit of the GC/MS

  7. Mass-accreting white dwarfs and type Ia supernovae

    Science.gov (United States)

    Wang, Bo

    2018-05-01

    Type Ia supernovae (SNe Ia) play a prominent role in understanding the evolution of the Universe. They are thought to be thermonuclear explosions of mass-accreting carbon-oxygen white dwarfs (CO WDs) in binaries, although the mass donors of the accreting WDs are still not well determined. In this article, I review recent studies on mass-accreting WDs, including H- and He-accreting WDs. I also review currently most studied progenitor models of SNe Ia, i.e., the single-degenerate model (including the WD+MS channel, the WD+RG channel and the WD+He star channel), the double-degenerate model (including the violent merger scenario) and the sub-Chandrasekhar mass model. Recent progress on these progenitor models is discussed, including the initial parameter space for producing SNe Ia, the binary evolutionary paths to SNe Ia, the progenitor candidates for SNe Ia, the possible surviving companion stars of SNe Ia, some observational constraints, etc. Some other potential progenitor models of SNe Ia are also summarized, including the hybrid CONe WD model, the core-degenerate model, the double WD collision model, the spin-up/spin-down model and the model of WDs near black holes. To date, it seems that two or more progenitor models are needed to explain the observed diversity among SNe Ia.

  8. Parental body mass index and blood pressure are associated with higher body mass index and blood pressure in their adult offspring: a cross-sectional study in a resource-limited setting in northern Peru.

    Science.gov (United States)

    Carrillo-Larco, Rodrigo M; Bernabé-Ortiz, Antonio; Sal Y Rosas, Víctor G; Sacksteder, Katherine A; Diez-Canseco, Francisco; Cárdenas, María K; Gilman, Robert H; Miranda, J Jaime

    2018-05-01

    High body mass index (BMI) and blood pressure (BP) are major contributors to the high burden of non-communicable diseases in adulthood. Individual high-risk and population approaches for prevention require newer strategies to target these risk factors and focusing on the family to introduce prevention initiatives appears as a promising scenario. Characterisation of the relationship between BMI and BP among the adult members of a given family merits evaluation. We conducted a secondary analysis of an implementation study in Tumbes, Peru, benefiting from data derived from families with at least one adult offspring. The exposures of interest were the BMI, systolic BP (SBP) and diastolic BP (DBP) of the mother and father. The outcomes were the BMI, SBP and DBP of the offspring. Mixed-effects linear regression models were conducted. The mean age of the offspring, mothers and fathers was 29 (SD: 9.5), 54 (SD: 11.8) and 59 (SD: 11.6) years, respectively. Father's BMI was associated with a quarter-point increase in offspring BMI, regardless of the sex of the offspring. Mother's BMI had a similar effect on the BMI of her sons, but had no significant effect on her daughters'. Mother's SBP was associated with almost one-tenth of mmHg increase in the SBP of the adult offspring. There was no evidence of an association for DBP. In families with adult members, the higher the parents' BMI and SBP, the higher their adult offspring's levels will be. © 2018 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  9. Text messaging as a strategy to address the limits of audio-based communication during mass-gathering events with high ambient noise.

    Science.gov (United States)

    Lund, Adam; Wong, Daniel; Lewis, Kerrie; Turris, Sheila A; Vaisler, Sean; Gutman, Samuel

    2013-02-01

    The provision of medical care in environments with high levels of ambient noise (HLAN), such as concerts or sporting events, presents unique communication challenges. Audio transmissions can be incomprehensible to the receivers. Text-based communications may be a valuable primary and/or secondary means of communication in this type of setting. To evaluate the usability of text-based communications in parallel with standard two-way radio communications during mass-gathering (MG) events in the context of HLAN. This Canadian study used outcome survey methods to evaluate the performance of communication devices during MG events. Ten standard commercially available handheld smart phones loaded with basic voice and data plans were assigned to health care providers (HCPs) for use as an adjunct to the medical team's typical radio-based communication. Common text messaging and chat platforms were trialed. Both efficacy and provider satisfaction were evaluated. During a 23-month period, the smart phones were deployed at 17 events with HLAN for a total of 40 event days or approximately 460 hours of active use. Survey responses from health care providers (177) and dispatchers (26) were analyzed. The response rate was unknown due to the method of recruitment. Of the 155 HCP responses to the question measuring difficulty of communication in environments with HLAN, 68.4% agreed that they "occasionally" or "frequently" found it difficult to clearly understand voice communications via two-way radio. Similarly, of the 23 dispatcher responses to the same item, 65.2% of the responses indicated that "occasionally" or "frequently" HLAN negatively affected the ability to communicate clearly with team members. Of the 168 HCP responses to the item assessing whether text-based communication improved the ability to understand and respond to calls when compared to radio alone, 86.3% "agreed" or "strongly agreed" that this was the case. The dispatcher responses (n = 21) to the same item also

  10. Neutrino mass matrix

    International Nuclear Information System (INIS)

    Strobel, E.L.

    1985-01-01

    Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed

  11. Heavy quark masses

    Science.gov (United States)

    Testa, Massimo

    1990-01-01

    In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.

  12. S Chandrasekhar: His Life and Science

    Indian Academy of Sciences (India)

    his beautiful writings on the problems of beauty and motivation in scientific life and on .... The final decision to do so was however not so easy and was even painful. .... Eddington did not breathe a word about it, making Chandra apprehensive.

  13. Scalar quarkonium masses

    International Nuclear Information System (INIS)

    Lee, W.; Weingarten, D.

    1996-01-01

    We evaluate the valence approximation to the mass of scalar quarkonium for a range of different parameters. Our results strongly suggest that the infinite volume continuum limit of the mass of ss scalar quarkonium lies well below the mass of f J (1710). The resonance f 0 (1500) appears to the best candidate for ss scalar quarkonium. (orig.)

  14. Why a New Code for Novae Evolution and Mass Transfer in Binaries?

    Directory of Open Access Journals (Sweden)

    G. Shaviv

    2015-02-01

    Full Text Available One of the most interesting problems in Cataclysmic Variables is the long time scale evolution. This problem appears in long time evolution, which is also very important in the search for the progenitor of SN Ia. The classical approach to overcome this problem in the simulation of novae evolution is to assume: (1 A constant in time, rate of mass transfer. (2 The mass transfer rate that does not vary throughout the life time of the nova, even when many eruptions are considered. Here we show that these assumptions are valid only for a single thermonuclear flash and such a calculation cannot be the basis for extrapolation of the behavior over many flashes. In particular, such calculation cannot be used to predict under what conditions an accreting WD may reach the Chandrasekhar mass and collapse. We report on a new code to attack this problem. The basic idea is to create two parallel processes, one calculating the mass losing star and the other the accreting white dwarf. The two processes communicate continuously with each other and follow the time depended mass loss.

  15. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  16. Quench limits

    International Nuclear Information System (INIS)

    Sapinski, M.

    2012-01-01

    With thirteen beam induced quenches and numerous Machine Development tests, the current knowledge of LHC magnets quench limits still contains a lot of unknowns. Various approaches to determine the quench limits are reviewed and results of the tests are presented. Attempt to reconstruct a coherent picture emerging from these results is taken. The available methods of computation of the quench levels are presented together with dedicated particle shower simulations which are necessary to understand the tests. The future experiments, needed to reach better understanding of quench limits as well as limits for the machine operation are investigated. The possible strategies to set BLM (Beam Loss Monitor) thresholds are discussed. (author)

  17. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  18. Accelerator-based ultrasensitive mass spectrometry

    International Nuclear Information System (INIS)

    Gove, H.E.

    1985-01-01

    This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

  19. Gamow's calculation of the neutron star's critical mass revised

    International Nuclear Information System (INIS)

    Ludwig, Hendrik; Ruffini, Remo

    2014-01-01

    It has at times been indicated that Landau introduced neutron stars in his classic paper of 1932. This is clearly impossible because the discovery of the neutron by Chadwick was submitted more than one month after Landau's work. Therefore, and according to his calculations, what Landau really did was to study white dwarfs, and the critical mass he obtained clearly matched the value derived by Stoner and later by Chandrasekhar. The birth of the concept of a neutron star is still today unclear. Clearly, in 1934, the work of Baade and Zwicky pointed to neutron stars as originating from supernovae. Oppenheimer in 1939 is also well known to have introduced general relativity (GR) in the study of neutron stars. The aim of this note is to point out that the crucial idea for treating the neutron star has been advanced in Newtonian theory by Gamow. However, this pioneering work was plagued by mistakes. The critical mass he should have obtained was 6.9 M, not the one he declared, namely, 1.5 M. Probably, he was taken to this result by the work of Landau on white dwarfs. We revise Gamow's calculation of the critical mass regarding calculational and conceptual aspects and discuss whether it is justified to consider it the first neutron-star critical mass. We compare Gamow's approach to other early and modern approaches to the problem.

  20. Double-detonation model of type Ia supernovae with a variable helium layer ignition mass

    International Nuclear Information System (INIS)

    Zhou Wei-Hong; Zhao Gang; Wang Bo

    2014-01-01

    Although Type Ia supernovae (SNe Ia) play an important role in the study of cosmology, their progenitors are still poorly understood. Thermonuclear explosions from the helium double-detonation sub-Chandrasekhar mass model have been considered as an alternative method for producing SNe Ia. By adopting the assumption that a double detonation occurs when a He layer with a critical ignition mass accumulates on the surface of a carbon—oxygen white dwarf (CO WD), we perform detailed binary evolution calculations for the He double-detonation model, in which a He layer from a He star accumulates on a CO WD. According to these calculations, we obtain the initial parameter spaces for SNe Ia in the orbital period and secondary mass plane for various initial WD masses. We implement these results into a detailed binary population synthesis approach to calculate SN Ia birthrates and delay times. From this model, the SN Ia birthrate in our Galaxy is ∼0.4 − 1.6 × 10 −3 yr −1 . This indicates that the double-detonation model only produces part of the SNe Ia. The delay times from this model are ∼ 70 – 710 Myr, which contribute to the young population of SNe Ia in the observations. We found that the CO WD + sdB star system CD–30 11223 could produce an SN Ia via the double-detonation model in its future evolution. (research papers)

  1. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  2. Measurements of neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1985-01-01

    Direct experimental information of neutrino mass as derived from the study of nuclear and elementary-particle weak decays is reviewed. Topics include tritium beta decay; the 3 He-T mass difference; electron capture decay of 163 Ho and 158 Tb; and limits on massive neutrinos from cosmology. 38 references

  3. Mass of the photon

    International Nuclear Information System (INIS)

    Goldhaber, A.S.; Nieto, M.M.

    1976-01-01

    Several experiments are discussed for which results are equivalent to the catching and weighing of a photon. It is noted that none of the experiments has proved the rest mass to be zero and that such a proof may be impossible. It is shown by such experiments that the rest mass is less than the limit of accuracy of the experiment. These limits have approached ever closer to zero, and the most recent values are exceedingly small

  4. Power limit and quality limit of natural circulation reactor

    International Nuclear Information System (INIS)

    Zhao Guochang; Ma Changwen

    1997-01-01

    The circulation characteristics of natural circulation reactor in boiling regime are researched. It is found that, the circulation mass flow rate and the power have a peak value at a mass quality respectively. Therefore, the natural circulation reactor has a power limit under certain technological condition. It can not be increased steadily by continually increasing the mass quality. Corresponding to this, the mass quality of natural circulation reactor has a reasonable limit. The relations between the maximum power and the reactor parameters, such as the resistance coefficient, the working pressure and so on, are analyzed. It is pointed out that the power limit of natural circulation reactor is about 1000 MW at present technological condition. Taking the above result and low quality stability experimental result into account, the authors recommend that the reasonable mass quality of natural circulation reactor working in boiling regime is from 2% to 3% under the researched working pressure

  5. Fourier Transform Mass Spectrometry

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-01-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook. PMID:21742802

  6. Masses of supernova progenitors

    International Nuclear Information System (INIS)

    Tinsley, B.M.

    1977-01-01

    The possible nature and masses of supernovae progenitors, and the bearing of empirical results on some unsolved theoretical problems concerning the origin of supernovae, are discussed. The author concentrates on two main questions: what is the lower mass limit for stars to die explosively and what stars initiate type I supernovae. The evidence considered includes local supernova rates, empirical estimates of msub(w) (the upper mass limit for death as a white dwarf), the distributions of supernovae among stellar populations in galaxies and the colors of supernova producing galaxies. (B.D.)

  7. Limits of Nuclear Stability

    CERN Document Server

    Nerlo-Pomorska, B; Kleban, M

    2003-01-01

    The modern version of the liquid-drop model (LSD) is compared with the macroscopic part of the binding energy evaluated within the Hartree-Fock- Bogoliubov procedure with the Gogny force and the relativistic mean field theory. The parameters of a liquid-drop like mass formula which approximate on the average the self-consistent results are compared with other models. The limits of nuclear stability predicted by these models are discussed.

  8. Mass discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Broeckman, A. [Rijksuniversiteit Utrecht (Netherlands)

    1978-12-15

    In thermal ionization mass spectrometry the phenomenon of mass discrimination has led to the use of a correction factor for isotope ratio-measurements. The correction factor is defined as the measured ratio divided by the true or accepted value of this ratio. In fact this factor corrects for systematic errors of the whole procedure; however mass discrimination is often associated just with the mass spectrometer.

  9. Negative mass

    International Nuclear Information System (INIS)

    Hammond, Richard T

    2015-01-01

    Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given. (paper)

  10. Tachyons in the Galilean limit

    Energy Technology Data Exchange (ETDEWEB)

    Batlle, Carles [Departament de Matemàtiques and IOC, Universitat Politècnica de Catalunya, EPSEVG,Av. V. Balaguer 1, Vilanova i la Geltrú, E-08808 (Spain); Gomis, Joaquim [Departament de Física Quàntica i Astrofísica and Institut de Ciències del Cosmos (ICCUB),Universitat de Barcelona, Martí i Franquès 1, Barcelona, E-08028 (Spain); Mezincescu, Luca [Department of Physics, University of Miami,P.O. Box 248046, Coral Gables, FL, 33124 (United States); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences,University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2017-04-20

    The Souriau massless Galilean particle of “colour” k and spin s is shown to be the Galilean limit of the Souriau tachyon of mass m=ik and spin s. We compare and contrast this result with the Galilean limit of the Nambu-Goto string and Green-Schwarz superstring.

  11. Nominal Mass?

    Science.gov (United States)

    Attygalle, Athula B; Pavlov, Julius

    2017-08-01

    The current IUPAC-recommended definition of the term "nominal mass," based on the most abundant naturally occurring stable isotope of an element, is flawed. We propose that Nominal mass should be defined as the sum of integer masses of protons and neutrons in any chemical species. In this way, all isotopes and isotopologues can be assigned a definitive identifier. Graphical Abstract ᅟ.

  12. Nuclear Structure at the Limits

    International Nuclear Information System (INIS)

    Nazarewicz, W.

    1998-01-01

    One of the frontiers of todays nuclear science is the journey to the limits of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei

  13. Very low mass stars

    International Nuclear Information System (INIS)

    Liebert, J.; Probst, R.G.

    1987-01-01

    This paper discusses several theoretical and observational topics involved in discovering and analyzing very low mass stellar objects below about 0.3 M circle, as well as their likely extension into the substellar range. The authors hereafter refer to these two classes of objects as VLM stars and brown dwarfs, respectively; collectively, they are called VLM objects. The authors outline recent theoretical work on low-mass stellar interiors and atmospheres, the determination of the hydrogen-burning mass limit, important dynamical evidence bearing on the expected numbers of such objects, and the expectations for such objects from star-formation theory. They focus on the properties of substellar objects near the stellar mass limit. Observational techniques used to discover and analyze VLM objects are summarized

  14. Evolutionary effects of mass loss in low-mass stars

    International Nuclear Information System (INIS)

    Renzini, A.

    1981-01-01

    The effects of mass loss on the evolution of low-mass stars (actual mass smaller than 1.4 solar masses) are reviewed. The case of globular cluster stars is discussed in some detail, and it is shown that evolutionary theory sets quite precise limits to the mass-loss rate in population II red giants. The effects of mass loss on the final evolutionary stages of stars producing white dwarfs is also discussed. In particular, the interaction of the wind from the hot central star with the surrounding planetary nebula is considered. Finally, the problem of the origin of hydrogen-deficient stars is briefly discussed. (Auth.)

  15. Localizability and the planck mass

    International Nuclear Information System (INIS)

    Ne'eman, Y.; Univ. of Texas, Austin, TX

    1993-06-01

    The author combines the assumption of environmental decoherence, as the mechanism generating the classical (i.e. no quantum interferences) nature of spacetime, with the limit on its other classical feature, point-like continuity, namely Planck length. As a result, quantum extended objects with masses larger than Planck mass have to derive their quantum behavior from long-range correlations; objects with masses smaller than Planck mass cannot display classical behavior

  16. Photon mass experiment

    International Nuclear Information System (INIS)

    Crandall, R.E.

    1983-01-01

    A Coulomb null experiment is described that enables physics students to obtain rigorous upper bounds on photon mass. The experimenter searches for subnanovolt signals that would escape a closed shell were photon mass to be positive. The approach can be adapted for several college levels. At the simplest level, a ''miniature'' low-cost experiment allows a student to verify the exponent ''-2'' in Coulomb's law to eight or more decimal places. An advanced student given a full-size apparatus (at greater cost) can obtain mass bounds very close to the established laboratory limit

  17. Neutrino mass experiments

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1989-01-01

    The current status of the experimental search for neutrino mass is reviewed, with emphasis on direct kinematic methods. Simpson and Hime report finding new evidence for a 17-keV neutrino in the β decay of 3 H and 35 S. The situation concerning the electron neutrino mass as measured in tritium beta decay has not changed significantly in the last two years. We discuss the ''model independent'' lower limit of 17 eV obtained by the ITEP group in light of existing data on the 3 H-- 3 He mass difference. 42 refs., 1 fig., 1 tab

  18. NEUTRINO MASS

    OpenAIRE

    Kayser, Boris

    1988-01-01

    This is a review article about the most recent developments on the field of neutrino mass. The first part of the review introduces the idea of neutrino masses and mixing angles, summarizes the most recent experimental data then discusses the experimental prospects and challenges in this area. The second part of the review discusses the implications of these results for particle physics and cosmology, including the origin of neutrino mass, the see-saw mechanism and sequential dominance, and la...

  19. Neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1992-01-01

    Despite intensive experimental work since the neutrino's existence was proposed by Pauli 60 years ago, and its first observation by Reines and Cowan almost 40 years ago, the neutrino's fundamental properties remain elusive. Among those properties are the masses of the three known flavors, properties under charge conjugation, parity and time-reversal, and static and dynamic electromagnetic moments. Mass is perhaps the most fundamental, as it constrains the other properties. The present status of the search for neutrino mass is briefly reviewed

  20. Limit of detection in the presence of instrumental and non-instrumental errors: study of the possible sources of error and application to the analysis of 41 elements at trace levels by inductively coupled plasma-mass spectrometry technique

    International Nuclear Information System (INIS)

    Badocco, Denis; Lavagnini, Irma; Mondin, Andrea; Tapparo, Andrea; Pastore, Paolo

    2015-01-01

    In this paper the detection limit was estimated when signals were affected by two error contributions, namely instrumental errors and operational-non-instrumental errors. The detection limit was theoretically obtained following the hypothesis testing schema implemented with the calibration curve methodology. The experimental calibration design was based on J standards measured I times with non-instrumental errors affecting each standard systematically but randomly among the J levels. A two-component variance regression was performed to determine the calibration curve and to define the detection limit in these conditions. The detection limit values obtained from the calibration at trace levels of 41 elements by ICP-MS resulted larger than those obtainable from a one component variance regression. The role of the reagent impurities on the instrumental errors was ascertained and taken into account. Environmental pollution was studied as source of non-instrumental errors. The environmental pollution role was evaluated by Principal Component Analysis technique (PCA) applied to a series of nine calibrations performed in fourteen months. The influence of the seasonality of the environmental pollution on the detection limit was evidenced for many elements usually present in the urban air particulate. The obtained results clearly indicated the need of using the two-component variance regression approach for the calibration of all the elements usually present in the environment at significant concentration levels. - Highlights: • Limit of detection was obtained considering a two variance component regression. • Calibration data may be affected by instrumental and operational conditions errors. • Calibration model was applied to determine 41 elements at trace level by ICP-MS. • Non instrumental errors were evidenced by PCA analysis

  1. Mass Society

    DEFF Research Database (Denmark)

    Borch, Christian

    2017-01-01

    the negative features usually ascribed by late nineteenth-century crowd psychology to spontaneous crowds, and attributes these to the entire social fabric. However, in contrast to crowd psychology, theorists of mass society often place greater emphasis on how capitalism, technological advances, or demographic......Mass society is a societal diagnosis that emphasizes – usually in a pejorative, modernity critical manner – a series of traits allegedly associated with modern society, such as the leveling of individuality, moral decay, alienation, and isolation. As such, the notion of mass society generalizes...... developments condition such negative features, and some theorists argue that mass society produces a propensity to totalitarianism. Discussions of mass society culminated in the early and mid-twentieth century....

  2. Mass hysteria

    CERN Document Server

    Hellemans, Alexander

    2004-01-01

    Considerable research is being undertaken to identify the Higgs particle that is believed to give things their mass. According to the standard model, what we call mass is really an indication of how strongly particles interact with an invisible syrupy substance called the Higgs field. Quantum mechanics say that the mass-giving field can also be thought of as a sea of electrically neutral Higgs particles that should be dislodged in collisions between subatomic particles with high enough energies. Particle physicists expect the Higgs to exist only for a fleeting moment before decaying into other particles, which are caught in a detector. (Edited abstract).

  3. The phantom menace. Determination of the true Method Detection Limit (MDL) for background levels of PCDDs, PCDFs, and cPCBs in human serum by high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Turner, W.; Welch, S.; DiPietro, E.; Cash, T.; McClure, C.; Needham, L.; Patterson, D. [CDC/ATSDR, Atlanta, GA (United States)

    2004-09-15

    The recent worldwide decline in background serum levels of polychlorinated dibenzo-p-dioxins, furans, and coplanar biphenyls (PCDDs/PCDFs/cPCBs) is unquestionably an important finding. However, as serum levels continue to diminish, our analytical methods for measuring these toxicants will continue to be ''pushed to their limit''. In a previous article, we investigated some of the variables that influence the quantification of ''ultra-trace'' (fg/g) concentrations of PCDDs/PCDFs and cPCBs in human serum. In this report, we continue to explore parameters that can affect the determination of the ''true'' detection limit of our method (MDL), using both analytical standards and matrix-based samples.

  4. Nucleon and delta masses in twisted mass chiral perturbation theory

    International Nuclear Information System (INIS)

    Walker-Loud, Andre; Wu, Jackson M.S.

    2005-01-01

    We calculate the masses of the nucleons and deltas in twisted mass heavy baryon chiral perturbation theory. We work to quadratic order in a power counting scheme in which we treat the lattice spacing, a, and the quark masses, m q , to be of the same order. We give expressions for the mass and the mass splitting of the nucleons and deltas both in and away from the isospin limit. We give an argument using the chiral Lagrangian treatment that, in the strong isospin limit, the nucleons remain degenerate and the delta multiplet breaks into two degenerate pairs to all orders in chiral perturbation theory. We show that the mass splitting between the degenerate pairs of the deltas first appears at quadratic order in the lattice spacing. We discuss the subtleties in the effective chiral theory that arise from the inclusion of isospin breaking

  5. THE POST-MERGER MAGNETIZED EVOLUTION OF WHITE DWARF BINARIES: THE DOUBLE-DEGENERATE CHANNEL OF SUB-CHANDRASEKHAR TYPE Ia SUPERNOVAE AND THE FORMATION OF MAGNETIZED WHITE DWARFS

    International Nuclear Information System (INIS)

    Ji Suoqing; Fisher, Robert T.; García-Berro, Enrique; Tzeferacos, Petros; Jordan, George; Lee, Dongwook; Lorén-Aguilar, Pablo; Cremer, Pascal; Behrends, Jan

    2013-01-01

    Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths ∼2 × 10 8 G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs

  6. The Post-merger Magnetized Evolution of White Dwarf Binaries: The Double-degenerate Channel of Sub-Chandrasekhar Type Ia Supernovae and the Formation of Magnetized White Dwarfs

    Science.gov (United States)

    Ji, Suoqing; Fisher, Robert T.; García-Berro, Enrique; Tzeferacos, Petros; Jordan, George; Lee, Dongwook; Lorén-Aguilar, Pablo; Cremer, Pascal; Behrends, Jan

    2013-08-01

    Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths ~2 × 108 G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.

  7. THE POST-MERGER MAGNETIZED EVOLUTION OF WHITE DWARF BINARIES: THE DOUBLE-DEGENERATE CHANNEL OF SUB-CHANDRASEKHAR TYPE Ia SUPERNOVAE AND THE FORMATION OF MAGNETIZED WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Ji Suoqing; Fisher, Robert T. [University of Massachusetts Dartmouth, Department of Physics, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Garcia-Berro, Enrique [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, E-08860 Castelldefels (Spain); Tzeferacos, Petros; Jordan, George; Lee, Dongwook [Center for Astrophysical Thermonuclear Flashes, The University of Chicago, Chicago, IL 60637 (United States); Loren-Aguilar, Pablo [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Cremer, Pascal [Bethe Center for Theoretical Physics, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany); Behrends, Jan [Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    2013-08-20

    Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths {approx}2 Multiplication-Sign 10{sup 8} G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.

  8. Anisotropic dynamic mass density for fluidsolid composites

    KAUST Repository

    Wu, Ying; Mei, Jun; Sheng, Ping

    2012-01-01

    By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle

  9. Atomic mass spectrometry

    International Nuclear Information System (INIS)

    Sanz-Medel, A.

    1997-01-01

    The elemental inorganic analysis seems to be dominated today by techniques based on atomic spectrometry. After an evaluation of advantages and limitations of using mass analysers (ion detectors) versus conventional photomultipliers (photon detector) a brief review of the more popular techniques of the emerging Atomic Mass spectrometry is carried out. Their huge potential for inorganic trace analysis is such that in the future we could well witness how this end of the century and millennium marked the fall of the photons empire in Analytical Atomic Spectrometry. (Author)

  10. Towards absolute neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr [Kellogg Radiation Laboratory 106-38, Caltech, Pasadena, CA 91125 (United States)

    2007-06-15

    Various ways of determining the absolute neutrino masses are briefly reviewed and their sensitivities compared. The apparent tension between the announced but unconfirmed observation of the 0{nu}{beta}{beta} decay and the neutrino mass upper limit based on observational cosmology is used as an example of what could happen eventually. The possibility of a 'nonstandard' mechanism of the 0{nu}{beta}{beta} decay is stressed and the ways of deciding which of the possible mechanisms is actually operational are described. The importance of the 0{nu}{beta}{beta} nuclear matrix elements is discussed and their uncertainty estimated.

  11. Efficient mass calibration of magnetic sector mass spectrometers

    International Nuclear Information System (INIS)

    Roddick, J.C.

    1996-01-01

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A·Mass 1/2 + B·(Mass) p where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs

  12. Efficient mass calibration of magnetic sector mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Roddick, J C

    1997-12-31

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A{center_dot}Mass{sup 1/2} + B{center_dot}(Mass){sup p} where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs.

  13. Limits to power system growth

    International Nuclear Information System (INIS)

    Slater, S.M.; Klein, A.C.; Webb, B.J.; Pauley, K.A.

    1993-01-01

    In the design of space nuclear power systems a variety of conversion techniques may be used, each with its own advantages and disadvantages. A study was performed which analyzed over 120 proposed system designs. The designs were compared to identify the optimum conversion system as a function of power level and find limits to specific mass (kg/kWe) for each power cycle. Furthermore, the component masses were studied to determine which component of the overall design contributes the most to total system mass over a variety of power levels. The results can provide a focus for future research efforts by selecting the best conversion technology for the desired power range, and optimizing the system component which contributes most to the total mass

  14. Neutrino mass?

    International Nuclear Information System (INIS)

    Kayser, B.

    1992-01-01

    After arguing that we should be looking for evidence of neutrino mass, we illustrate the possible consequences of neutrino mass and mixing. We then turn to the question of whether neutrinos are their own antiparticles, and to the process which may answer this question: neutrinoless double beta decay. Next, we review the proposed Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem, and discuss models which can generate neutrino electromagnetic moments large enough to play a role in the sun. Finally, we consider how the possible 17 keV neutrino, if real, would fit in with everything we know about neutrinos. (orig.)

  15. Mass metrology

    CERN Document Server

    Gupta, S V

    2012-01-01

    This book presents the practical aspects of mass measurements. Concepts of gravitational, inertial and conventional mass and details of the variation of acceleration of gravity are described. The Metric Convention and International Prototype Kilogram and BIPM standards are described. The effect of change of gravity on the indication of electronic balances is derived with respect of latitude, altitude and earth topography. The classification of weights by OIML is discussed. Maximum permissible errors in different categories of weights prescribed by national and international organizations are p

  16. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained...

  17. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  18. Definition of the limit of quantification in the presence of instrumental and non-instrumental errors. Comparison among various definitions applied to the calibration of zinc by inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Badocco, Denis; Lavagnini, Irma; Mondin, Andrea; Favaro, Gabriella; Pastore, Paolo

    2015-12-01

    The limit of quantification (LOQ) in the presence of instrumental and non-instrumental errors was proposed. It was theoretically defined combining the two-component variance regression and LOQ schemas already present in the literature and applied to the calibration of zinc by the ICP-MS technique. At low concentration levels, the two-component variance LOQ definition should be always used above all when a clean room is not available. Three LOQ definitions were accounted for. One of them in the concentration and two in the signal domain. The LOQ computed in the concentration domain, proposed by Currie, was completed by adding the third order terms in the Taylor expansion because they are of the same order of magnitude of the second ones so that they cannot be neglected. In this context, the error propagation was simplified by eliminating the correlation contributions by using independent random variables. Among the signal domain definitions, a particular attention was devoted to the recently proposed approach based on at least one significant digit in the measurement. The relative LOQ values resulted very large in preventing the quantitative analysis. It was found that the Currie schemas in the signal and concentration domains gave similar LOQ values but the former formulation is to be preferred as more easily computable.

  19. Neutrino masses and mixings

    International Nuclear Information System (INIS)

    Wolfenstein, L.

    1991-01-01

    Theoretical prejudices, cosmology, and neutrino oscillation experiments all suggest neutrino mass are far below present direct experimental limits. Four interesting scenarios and their implications are discussed: (1) a 17 keV ν τ , (2) a 30 ev ν τ making up the dark matter, (3) a 10 -3 ev ν μ to solve the solar neutrino problem, and (4) a three-neutrino MSW solution

  20. Status of neutrino mass experiments

    International Nuclear Information System (INIS)

    Fackler, O.

    1985-01-01

    In 1980 two experiments ignited a fertile field of research - the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily the author discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. Section I begins with a discussion of astronomical and terrestrial observations which motivated these experiments. In Section II, the author quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other paper. The author continues by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations are reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks

  1. Status of neutrino mass experiments

    International Nuclear Information System (INIS)

    Fackler, O.

    1985-12-01

    In 1980 two experiments ignited a fertile field of research the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily I will discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. However, let me begin in Section I to discuss astronomical and terrestrial observations which motivated these experiments. In Section II, I will quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other papers. I will continue by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations will be reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks. 24 refs., 24 figs

  2. Correlations among static quark masses

    International Nuclear Information System (INIS)

    Lewin, K.; Motz, G.B.

    1987-01-01

    Nonrelativistic heavy quarkonia potentials with Coulomb and linearly rising limiting behaviour are correlated additively by Taylor expansion extracting the limiting structure and a constant term. Relations between fit parameters of different potentials including the quark masses m b and m c , are obtained. The known stability of the difference m b -m c , appears as direct consequence of flavour invariance of the potentials

  3. Mass and heat transfers in the parietal boundary layer and inside a flat porous wall submitted to effusion or transpiration; Transferts de masse et de chaleur dans la couche limite parietale et a l'interieur d'une paroi poreuse plane soumise a de l'effusion ou de la transpiration

    Energy Technology Data Exchange (ETDEWEB)

    Bellettre, J.

    1998-12-01

    The flows and the heat transfer near and inside a porous wall subjected to an internal flow are numerically and experimentally studied. Numerical simulations of the main flow are performed using a classical model of turbulence (RNG k-{xi} model). A discrete modeling of blowing through a porous plate is developed in order to predict interactions between the main flow and the injected fluid. Numerical results are in good agreement with experimental data obtained with a subsonic wind tunnel. The coupling between the heat transfer near and inside porous plates is studied for different injection rates, main flow temperatures and internal exchange surfaces of porous media. Surfaces temperatures are calculated using a nodal model of internal heat transfer, linked to the model of boundary layer submitted to injection. By comparing numerical and experimental temperatures of walls, the heat transfer coefficients inside porous media are calculated. In order to improve the thermal protection of walls, the transpiration with a liquid is studied. Experimental results, obtained with ethanol injection whereas the main flow is gaseous, show an important enhancement of the protection process. The coolant evaporation rate is calculated using measurement of mass fraction in the boundary layer and is used for the numerical study of mass transfer in the boundary layer. (author)

  4. Chandrasekhar's book An Introduction to the Study of Stellar Structure

    Indian Academy of Sciences (India)

    How close are we to seeing a book with the title 'The Last Word on the Study ... believe) no one at that time had taken the trouble to translate into English. ... When I first saw the solution (6), I thought that perhaps a use can be found for it as an.

  5. The legacy of S Chandrasekhar (1910–1995)

    Indian Academy of Sciences (India)

    chiefly responsible for making it the foremost Journal of this kind in the world. ... essays exploring aesthetics and motivations in science and some historical ..... In the face of such opposition, Chandra made a wise decision to gracefully ...

  6. Mass Sports

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2017-03-01

    Fitness has become one of the most popular kinds of the mass sport and has completely replaced the traditional “physical culture”. Dozens of variations of fitness and millions of participants pose a great challenge to contemporary architecture. The articles of our issue show the present and the future of architecture for fitness. We present a topical collection with a wide geographical range, including the Irkutsk Agglomeration, Tomsk, Krasnodar, sports in the Moscow Palace of Young Pioneers, and the anthology of the top foreign sports venues.

  7. Critical Mass

    CERN Multimedia

    AUTHOR|(CDS)2070299

    2017-01-01

    Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. At CERN it is held once a year in conjunction with the national Swiss campaing "Bike to work".

  8. Additivity of quark masses in gauge theories

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1987-01-01

    It is shown that, in spite of the confinement of quarks in (color-singlet) hadrons, effective quark masses of all types (dynamically generated, constituent and current masses), naturally form hadron masses in an additivity fashion. For the purposes of brevity, the discussion is limited primarily to the nonstrange flavor sector

  9. Limit cycles in quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Patrick

    2015-04-27

    In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

  10. Boundaries of mass resolution in native mass spectrometry.

    Science.gov (United States)

    Lössl, Philip; Snijder, Joost; Heck, Albert J R

    2014-06-01

    Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)-protein interactions, to nanomachineries such as the proteasome and ribosome, to even virus assembly. In native MS, ions attain high m/z values, requiring special mass analyzers for their detection. Depending on the particular mass analyzer used, instrumental mass resolution does often decrease at higher m/z but can still be above a couple of thousand at m/z 5000. However, the mass resolving power obtained on charge states of protein complexes in this m/z region is experimentally found to remain well below the inherent instrument resolution of the mass analyzers employed. Here, we inquire into reasons for this discrepancy and ask how native MS would benefit from higher instrumental mass resolution. To answer this question, we discuss advantages and shortcomings of mass analyzers used to study intact biomolecules and biomolecular complexes in their native state, and we review which other factors determine mass resolving power in native MS analyses. Recent examples from the literature are given to illustrate the current status and limitations.

  11. The Mass/Eccentricity Limit in Double Star Astronomy

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    tems – essential for the computation of the semi-axis major and thus of the areal constant in astronomical units – has been the most important stumbling-block. In order to evade this difficulty, we systematically used the dynamical parallaxes because they are available for each orbit and because they have a uniform accuracy.

  12. Direct neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Weinheimer, Christian, E-mail: weinheimer@uni-muenster.de [Westfaelische Wilhelms-Universitaet, Institut fuer Kernphysik (Germany)

    2013-03-15

    Direct neutrino mass experiments are complementary to searches for neutrinoless double {beta}-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c{sup 2} . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c{sup 2} by increasing strongly the statistics and-at the same time-reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium {beta}-decay experiments cryo-bolometers investigating the endpoint region of {sup 187}Re {beta}-decay or the electron capture of {sup 163}Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.

  13. Glueball masses in quantum chromodynamics

    International Nuclear Information System (INIS)

    Luo Xiangqian; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Chen Qizhou; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Guo Shuohong; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Fang Xiyan; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou; Liu Jinming; Zhongshan Univ., Guangzhou, GD; Zhongshan Univ., Guangzhou

    1996-01-01

    We review the recent glueball mass calculations using an efficient method for solving the Schroedinger equation order by order with a scheme preserving the continuum limit. The reliability of the method is further supported by new accurate results for (1+1)-dimensional σ models and (2+1)-dimensional non-abelian models. We present first and encouraging data for the glueball masses in 3+1 dimensional QCD. (orig.)

  14. Neutrino mass: Recent results

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1989-01-01

    Some recent developments in the experimental search for neutrino mass are discussed. Simpson and Hime report finding new evidence for a 17-keV neutrino in the β decay of 3 H and 35 S. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 13.5 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a ''model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. 38 refs., 1 figs., 2 tabs

  15. Subcritical limits for special fissile actinides

    International Nuclear Information System (INIS)

    Clark, H.K.

    1980-01-01

    Critical masses and subcritical mass limits in oxide-water mixtures were calculated for actinide nuclides other than 233 U, 235 U, and 239 Pu that have an odd number of neutrons in the nucleus: S/sub n/ transport theory was used together with cross sections, drawn from the GLASS multigroup library, developed to provide accurate forecasts of actinide production at Savannah River. The subcritical limits are 201 g for 241 Pu, 13 g for 242 /sup m/Am, 90 g for 243 Cm, 30 g for 245 Cm, 900 g for 247 Cm, 10 g for 249 Cf, and 5 g for 251 Cf. Association of 241 Pu with an equal mass of 240 Pu increases the 241 Pu limit to a value greater than that for pure 239 Pu. Association of 242 /sup m/Am with 241 Am increases the limit for the mixture to that for dry, theoretical density AmO 2 at isotopic concentrations of 242 /sup m/Am less than approx. 6%. Association of 245 Cm with 244 Cm increases the limit according to the formula 30 + 0.3 244 Cm/ 245 Cm up to the limit for dry CmO 2 . A limiting mass of 8.15 kg for plutonium containing at least 67% 238 Pu as oxide was calculated that applies (provided 240 Pu exceeds 241 Pu) with no limit on moderation. 1 figure, 5 tables

  16. Partnerships – Limited partnerships and limited liability limited partnerships

    OpenAIRE

    Henning, Johan J.

    2000-01-01

    Consideration of the Limited Liability Partnership Act 2000 which introduced a new corporate entity, carrying the designations “partnership” and “limited” which allow members to limit their liability whilst organising themselves internally as a partnership. Article by Professor Johan Henning (Director of the Centre for Corporate Law and Practice, IALS and Dean of the Faculty of Law, University of the Free State, South Africa). Published in Amicus Curiae - Journal of the Institute of Advanced ...

  17. Mass splitting induced by gravitation

    International Nuclear Information System (INIS)

    Maia, M.D.

    1982-08-01

    The exact combination of internal and geometrical symmetries and the associated mass splitting problem is discussed. A 10-parameter geometrical symmetry is defined in a curved space-time in such a way that it is a combination of de Sitter groups. In the flat limit it reproduces the Poincare-group and its Lie algebra has a nilpotent action on the combined symmetry only in that limit. An explicit mass splitting expression is derived and an estimation of the order of magnitude for spin-zero mesons is made. (author)

  18. Twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Shindler, A.

    2007-07-01

    I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

  19. Twisted mass lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Shindler, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2007-07-15

    I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

  20. 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.

  1. HOME Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

  2. Masses of Nix and Hydra

    Science.gov (United States)

    Tholen, David J.; Buie, M. W.; Grundy, W.

    2007-05-01

    Two new, small satellites of Pluto were discovered in 2005 using deep images from the Hubble Space Telescope. The IAU has approved the name Hydra for the outermost satellite and the name Nix for the one orbiting at an intermediate distance between Charon and Hydra. We used the two discovery observations of Nix and Hydra from 2005, the two confirmation observations from 2006, and the twelve prediscovery observations from 2001 and 2002, as well as available observations of Charon, to perform a four-body orbit solution for the Pluto system. Mutual perturbations have placed constraints on the masses of each member of the system. Previous work placed useful limits on the masses of Pluto and Charon, as well as their densities, given the known sizes of the bodies based on stellar occultation and mutual event observations, therefore our new work is aimed at placing constraints on the masses of Nix and Hydra. The best-fit GM values for Nix and Hydra are 0.040 and 0.021 km3 sec-2. The uncertainty in the GM of Hydra is large enough to allow for a negligible mass. At the one-sigma level, we can rule out masses near the upper limit of what is physically reasonable (correpsonding to a combination of low albedos and high densities) for both satellites, and in the case of Nix, we can also rule out a mass near the lower limit (corresponding to a high albedo and low density). We have determined empirically that the rate of precession of the line of apsides of Charon's slightly eccentric orbit is proportional to the mass of Nix and Hydra. New HST observations of the satellites are scheduled, which should improve the orbit solution and reduce the uncertainties in the masses. Ultimately, these results will place constraints on models for the formation of the system.

  3. The 2011 Outburst of Recurrent Nova T Pyx: X-Ray Observations Expose the White Dwarf Mass and Ejection Dynamics

    Science.gov (United States)

    Chomiuk, Laura; Nelson, Thomas; Mukai, Koji; Solokoski, J. L.; Rupen, Michael P.; Page, Kim L.; Osborne, Julian P.; Kuulkers, Erik; Mioduszewski, Amy J.; Roy, Nirupam; hide

    2014-01-01

    The recurrent nova T Pyx underwent its sixth historical outburst in 2011, and became the subject of an intensive multi-wavelength observational campaign.We analyze data from the Swift and Suzaku satellites to produce a detailed X-ray light curve augmented by epochs of spectral information. X-ray observations yield mostly non-detections in the first four months of outburst, but both a super-soft and hard X-ray component rise rapidly after Day 115. The super-soft X-ray component, attributable to the photosphere of the nuclear-burning white dwarf, is relatively cool (approximately 45 electron volts) and implies that the white dwarf in T Pyx is significantly below the Chandrasekhar mass (approximately 1 M). The late turn-on time of the super-soft component yields a large nova ejecta mass (approximately greater than 10(exp -5) solar mass), consistent with estimates at other wavelengths. The hard X-ray component is well fit by a approximately 1 kiloelectron volt thermal plasma, and is attributed to shocks internal to the 2011 nova ejecta. The presence of a strong oxygen line in this thermal plasma on Day 194 requires a significantly super-solar abundance of oxygen and implies that the ejecta are polluted by white dwarf material. The X-ray light curve can be explained by a dual-phase ejection, with a significant delay between the first and second ejection phases, and the second ejection finally released two months after outburst. A delayed ejection is consistent with optical and radio observations of T Pyx, but the physical mechanism producing such a delay remains a mystery.

  4. Limits on fundamental limits to computation.

    Science.gov (United States)

    Markov, Igor L

    2014-08-14

    An indispensable part of our personal and working lives, computing has also become essential to industries and governments. Steady improvements in computer hardware have been supported by periodic doubling of transistor densities in integrated circuits over the past fifty years. Such Moore scaling now requires ever-increasing efforts, stimulating research in alternative hardware and stirring controversy. To help evaluate emerging technologies and increase our understanding of integrated-circuit scaling, here I review fundamental limits to computation in the areas of manufacturing, energy, physical space, design and verification effort, and algorithms. To outline what is achievable in principle and in practice, I recapitulate how some limits were circumvented, and compare loose and tight limits. Engineering difficulties encountered by emerging technologies may indicate yet unknown limits.

  5. The luminosity and mass functions of the Pleiades: low-mass stars and brown dwarfs

    International Nuclear Information System (INIS)

    Hambly, N.C.; Jameson, R.F.

    1991-01-01

    COSMOS measurements of R and I Schmidt plates are used to determine the luminosity function and hence mass function of the Pleiades open cluster. Star counts are made in the cluster and the field star contribution, measured outside the cluster, is subtracted. A lower limit of 30 brown dwarfs is found; the mass function is flat at the lowest masses. (author)

  6. Penrose limits and RG flows

    International Nuclear Information System (INIS)

    Gimon, Eric G.; Sonnenschein, Jacob; Pando Zayas, Leopoldo A.

    2002-01-01

    The Penrose-Gueven limit simplifies a given supergravity solution into a pp-wave background. Aiming at clarifying its relation to renormalization group flow we study the Penrose-Guven limit of supergravity backgrounds that are dual to non-conformal gauge theories. The resulting backgrounds fall in a class simple enough that the quantum particle is exactly solvable. We propose a map between the effective time-dependent quantum mechanical problem and the RG flow in the gauge theory. As a testing ground we consider explicitly two Penrose limits of the infrared fixed point of the Pilch-Warner solution. We analyze the corresponding gauge theory picture and write down the operators which are the duals of the low lying string states. We also address RG flows of a different nature by considering the Penrose-Gueven limit of a stack of N D p branes. We note that in the far IR (for p<3)the limit generically has negative mass-squared. This phenomenon signals, in the world sheet picture, the necessity to transform to another description. In this regard, we consider explicitly the cases of M2 from D2 and F1 from D1. (author)

  7. Determination of the Meteor Limiting Magnitude

    Science.gov (United States)

    Kingery, A.; Blaauw, R.; Cooke, W. J.

    2016-01-01

    The limiting meteor magnitude of a meteor camera system will depend on the camera hardware and software, sky conditions, and the location of the meteor radiant. Some of these factors are constants for a given meteor camera system, but many change between meteor shower or sporadic source and on both long and short timescales. Since the limiting meteor magnitude ultimately gets used to calculate the limiting meteor mass for a given data set, it is important to have an understanding of these factors and to monitor how they change throughout the night, as a 0.5 magnitude uncertainty in limiting magnitude translates to a uncertainty in limiting mass by a factor of two.

  8. Possible nonvanishing mass of photon

    International Nuclear Information System (INIS)

    Nakazato, Hiromichi; Namiki, Mikio; Yamanaka, Yoshiya; Yokoyama, Kan-ichi.

    1985-05-01

    From phenomenological and field-theoretical considerations on photon mass, we first show that photon is not limitted to being massless at the present stage. Next we illustrate a possibility of formulating a local field theory for massive photons coupled with nonconserved currents, while we cannot do for massless photons. (author)

  9. Mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

  10. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging.

    Science.gov (United States)

    Kiss, András; Smith, Donald F; Jungmann, Julia H; Heeren, Ron M A

    2013-12-30

    Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with polyatomic primary ion sources, are required to exploit the full potential of microscope mode mass spectrometry imaging, i.e. to efficiently push the limits of ultra-high spatial resolution, sample throughput and sensitivity. In this work, a C60 primary source was combined with a commercial mass microscope for microscope mode secondary ion mass spectrometry imaging. The detector setup is a pixelated detector from the Medipix/Timepix family with high-voltage post-acceleration capabilities. The system's mass spectral and imaging performance is tested with various benchmark samples and thin tissue sections. The high secondary ion yield (with respect to 'traditional' monatomic primary ion sources) of the C60 primary ion source and the increased sensitivity of the high voltage detector setup improve microscope mode secondary ion mass spectrometry imaging. The analysis time and the signal-to-noise ratio are improved compared with other microscope mode imaging systems, all at high spatial resolution. We have demonstrated the unique capabilities of a C60 ion microscope with a Timepix detector for high spatial resolution microscope mode secondary ion mass spectrometry imaging. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Subcritical limits for special fissile actinides

    International Nuclear Information System (INIS)

    Clark, H.K.

    1980-01-01

    Critical masses and subcritical mass limits in oxide-water mixtures were calculated for actinide nuclides other than /sup 233/U, /sup 235/U, and /sup 239/Pu that have an odd number of neutrons in the nucleus; S/sub n/ transport theory was used together with cross sections, drawn from the GLASS multigroup library, developed to provide accurate forecasts of actinide production at Savannah River

  12. Toward quantum-limited position measurements using optically levitated microspheres

    International Nuclear Information System (INIS)

    Libbrecht, Kenneth G.; Black, Eric D.

    2004-01-01

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements

  13. Toward quantum-limited position measurements using optically levitated microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Libbrecht, Kenneth G.; Black, Eric D

    2004-01-26

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements.

  14. Fundamental gravitational limitations to quantum computing

    International Nuclear Information System (INIS)

    Gambini, R.; Porto, A.; Pullin, J.

    2006-01-01

    Lloyd has considered the ultimate limitations the fundamental laws of physics place on quantum computers. He concludes in particular that for an 'ultimate laptop' (a computer of one liter of volume and one kilogram of mass) the maximum number of operations per second is bounded by 10 51 . The limit is derived considering ordinary quantum mechanics. Here we consider additional limits that are placed by quantum gravity ideas, namely the use of a relational notion of time and fundamental gravitational limits that exist on time measurements. We then particularize for the case of an ultimate laptop and show that the maximum number of operations is further constrained to 10 47 per second. (authors)

  15. Nucleon form factors. Probing the chiral limit

    Energy Technology Data Exchange (ETDEWEB)

    Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Technische Univ. Muenchen, Garching (Germany). Physik-Dept.; Horsley, R. [Edinburgh Univ. (GB). School of Physics] (and others)

    2006-10-15

    The electromagnetic form factors provide important hints for the internal structure of the nucleon and continue to be of major interest for experimentalists. For an intermediate range of momentum transfers the form factors can be calculated on the lattice. However, reliability of the results is limited by systematic errors due to the required extrapolation to physical quark masses. Chiral effective field theories predict a rather strong quark mass dependence in a range which was yet unaccessible for lattice simulations. We give an update on recent results from the QCDSF collaboration using gauge configurations with Nf=2, non-perturbatively O(a)-improved Wilson fermions at very small quark masses down to 340 MeV pion mass, where we start to probe the relevant quark mass region. (orig.)

  16. Nucleon form factors. Probing the chiral limit

    International Nuclear Information System (INIS)

    Goeckeler, M.; Haegler, P.; Horsley, R.

    2006-10-01

    The electromagnetic form factors provide important hints for the internal structure of the nucleon and continue to be of major interest for experimentalists. For an intermediate range of momentum transfers the form factors can be calculated on the lattice. However, reliability of the results is limited by systematic errors due to the required extrapolation to physical quark masses. Chiral effective field theories predict a rather strong quark mass dependence in a range which was yet unaccessible for lattice simulations. We give an update on recent results from the QCDSF collaboration using gauge configurations with Nf=2, non-perturbatively O(a)-improved Wilson fermions at very small quark masses down to 340 MeV pion mass, where we start to probe the relevant quark mass region. (orig.)

  17. Robust test limits

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

    1997-01-01

    Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

  18. Light baryon masses with dynamical twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, C. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Baron, R. [CEA-Saclay, IRFU/Service de Physique Nucleaire, Gif-sur-Yvette (France); Blossier, B. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (DE). John von Neumann-Inst. fuer Computing NIC] (and others)

    2008-03-15

    We present results on the mass of the nucleon and the {delta} using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at {beta}=3.9 and {beta}=4.05 and on a lattice of 2.4 fm at {beta}=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at {beta}=3.9 and {beta}=4.05 we find a nucleon mass of 964{+-}28(stat.){+-}8(syst.) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p{sup 3}) and O(p{sup 4}) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p{sup 3}) we find a{sub {beta}}{sub =3.9}=0.0890{+-}0.0039(stat.){+-}0.0014(syst.) fm, and a{sub {beta}}{sub =4.05}=0.0691{+-}0.0034(stat.){+-}0.0010(syst.) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r0m we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the {delta}-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at {beta}=3.9 and {beta}=4.05 we find for the masses of the {delta}{sup ++,-} and {delta}{sup +,0} 1316{+-}60(stat.) MeV and 1330{+-}74(stat.) MeV respectively. We confirm

  19. Light baryon masses with dynamical twisted mass fermions

    International Nuclear Information System (INIS)

    Alexandrou, C.; Blossier, B.

    2008-03-01

    We present results on the mass of the nucleon and the Δ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at β=3.9 and β=4.05 and on a lattice of 2.4 fm at β=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find a nucleon mass of 964±28(stat.)±8(syst.) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p 3 ) and O(p 4 ) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p 3 ) we find a β=3.9 =0.0890±0.0039(stat.)±0.0014(syst.) fm, and a β=4.05 =0.0691±0.0034(stat.)±0.0010(syst.) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r0m we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the Δ-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find for the masses of the Δ ++,- and Δ +,0 1316±60(stat.) MeV and 1330±74(stat.) MeV respectively. We confirm that in the continuum limit they are also degenerate. (orig.)

  20. Light baryon masses with dynamical twisted mass fermions

    International Nuclear Information System (INIS)

    Alexandrou, C.; Korzec, T.; Koutsou, G.; Baron, R.; Guichon, P.; Blossier, B.; Herdoiza, G.; Jansen, K.; Brinet, M.; Carbonell, J.; Drach, V.; Dimopoulos, P.; Frezzotti, R.; Farchioni, F.; Liu, Z.; Pene, O.; Michael, C.; Shindler, A.; Urbach, C.; Wenger, U.

    2008-01-01

    We present results on the mass of the nucleon and the Δ using two dynamical degenerate twisted mass quarks and the tree-level Symanzik improved gauge action. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm at three lattice spacings less than 0.1 fm. We check for cutoff effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at β=3.9 and β=4.05 and on a lattice of 2.4 fm at β=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find a nucleon mass of 963±12(stat)±8(syst) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p 3 ) and O(p 4 ) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p 3 ) we find a β=3.9 =0.0889±0.0012(stat)±0.0014(syst) fm, and a β=4.05 =0.0691±0.0010(stat)±0.0010(syst) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r 0 m π we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the Δ-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find for the masses of the Δ ++,- and Δ +,0 1315±24(stat) MeV and 1329±30(stat) MeV, respectively. We confirm that in the continuum limit

  1. Mass Customization Services

    DEFF Research Database (Denmark)

    Friedrich, Gerhard

    Topics of the IMCM’08 & PETO’08 and this book are: Mass customization in service, mass customizing financial services, mass customization in supply networks, implementation issues in logistics, product life cycle and mass customization. The research field of mass customization is more than 15 years...

  2. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  3. Masses in the Weinberg-Salam model

    International Nuclear Information System (INIS)

    Flores, F.A.

    1984-01-01

    This thesis is a detailed discussion of the currently existing limits on the masses of Higgs scalars and fermions in the Weinberg-Salam model. The spontaneous breaking of the gauge symmetry of the model generates arbitrary masses for Higgs scalars and fermions, which for the known fermions have to be set to their experimentally known values. In this thesis, the authors discuss in detail both the theoretical and experimental constraints on these otherwise arbitrary masses

  4. Neutrino masses and mixing

    International Nuclear Information System (INIS)

    Fogli, G.

    1998-01-01

    The paper presents an analysis of the solar neutrino problem in terms of both Mikheyev-Smirnov-Wolfenstein (MSW) and vacuum neutrino oscillations, with the inclusion of the data collected by the SuperKamiokande experiment during 306.3 days of operation. In particular, the observed energy spectrum of the recoil electrons from 8 B neutrino scattering is discussed in detail and used to constrain the mass-mixing parameter space. Going to the atmospheric neutrino anomaly, the paper performs both a two- and three-flavor analysis of the most recent SuperKamiokande atmospheric neutrino data. The variations of the zenith distributions of ν events in the presence of flavor oscillations are investigated. It is seen that fits to the SK data, with and without the addition of the CHOOZ constrains, strongly limit the parameter space. Detailed bounds in triangle graphs are reported

  5. Common Psycholinguistic Themes in Mass Murderer Manifestos

    Science.gov (United States)

    Hamlett, Laura E.

    2017-01-01

    Mass murder in the United States is increasing, yet understanding of mass murderers is still relatively limited. Many perpetrators compose manifestos, which include journals, blogs, letters, videos, and other writings. Previous research has indicated that personal messages are of great social and psychological importance; however, there remains an…

  6. 7 CFR 1400.204 - Limited partnerships, limited liability partnerships, limited liability companies, corporations...

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Limited partnerships, limited liability partnerships..., limited liability partnerships, limited liability companies, corporations, and other similar legal entities. (a) A limited partnership, limited liability partnership, limited liability company, corporation...

  7. From Stars to Superplanets: The Low-Mass Initial Mass Function in the Young Cluster IC 348

    National Research Council Canada - National Science Library

    Najita, Joan R; Tiede, Glenn P; Carr, John S

    2000-01-01

    We investigate the low-mass population of the young cluster IC 348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using a new and innovative...

  8. JET pump limiter

    International Nuclear Information System (INIS)

    Sonnenberg, K.; Deksnis, E.; Shaw, R.; Reiter, D.

    1988-01-01

    JET plans to install two pump limiter modules which can be used for belt-limiter, inner-wall and X-point discharges and, also, for 1-2s as the main limiter. A design is presented which is compatible with two diagnostic systems, and which allows partial removal of the pump limiter to provide access for remote-handling operations. The high heat-flux components are initially cooled during a pulse. Heat is removed between discharges by radiation and pressure contacts to a water-cooled support structure. The pumping edge will be made of annealed pyrolytic graphite. Exhaust efficiency has been estimated, for a 1-d edge model, using a Monte-Carlo calculation of neutral gas transport. When the pump limiter is operated together with other wall components we expect an efficiency of ≅ 5% (2.5 x 10 21 part/s). As a main limiter the efficiency increases to about 10%. (author)

  9. UV DRIVEN EVAPORATION OF CLOSE-IN PLANETS: ENERGY-LIMITED, RECOMBINATION-LIMITED, AND PHOTON-LIMITED FLOWS

    International Nuclear Information System (INIS)

    Owen, James E.; Alvarez, Marcelo A.

    2016-01-01

    We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization front becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes

  10. Reactor limit control system

    International Nuclear Information System (INIS)

    Rubbel, F.E.

    1982-01-01

    The very extensive use of limitations in the operational field between protection system and closed-loop controls is an important feature of German understanding of operational safety. The design of limitations is based on very large activities in the computational field but mostly on the high level of the plant-wide own commissioning experience of a turnkey contractor. Limitations combine intelligence features of closed-loop controls with the high availability of protection systems. (orig.)

  11. Detector limitations, STAR

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D. G.

    1998-07-13

    Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

  12. Performance limitations at ISABELLE

    International Nuclear Information System (INIS)

    Keil, E.

    1975-01-01

    The transverse stability of coasting beams in the planned ISABELLE storage rings was studied. The beam--beam tune shift limitation at 0.005 can be avoided, and a computer simulation seems to show 0.005 is a pessimistic limit. For beams of reasonable smoothness on the edge, the actual limit should be somewhat higher. Some coupling effects due to the beam--beam interaction are also examined

  13. Limit loads in nozzles

    International Nuclear Information System (INIS)

    Zouain, N.

    1983-01-01

    The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author) [pt

  14. Limit analysis via creep

    International Nuclear Information System (INIS)

    Taroco, E.; Feijoo, R.A.

    1981-07-01

    In this paper it is presented a variational method for the limit analysis of an ideal plastic solid. This method has been denominated as Modified Secundary Creep and enables to find the collapse loads through a minimization of a functional and a limit process. Given an ideal plastic material it is shown how to determinate the associated secundary creep constitutive equation. Finally, as an application, it is found the limit load in an pressurized von Mises rigid plastic sphere. (Author) [pt

  15. Limiting rotational period of neutron stars

    Science.gov (United States)

    Glendenning, Norman K.

    1992-11-01

    We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442Msolar neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars.

  16. Limiting rotational period of neutron stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1992-01-01

    We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442M circle-dot neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars

  17. Impact-limiting materials characterization

    International Nuclear Information System (INIS)

    Glass, R.E.; Duffey, T.A.; McConnell, P.

    1993-01-01

    Three types of impact-limiting materials have been characterized which have applications in packages for the transport of radioactive materials. These materials are aluminum honeycombs, polyurethane foams, and aluminum foams. The results of the materials characterization have indicated strengths and weaknesses for each type of material. The polyurethane foams provide good impact limiting ability and excellent thermal insulation. However, they burn when subjected to the regulatory thermal event in the presence of air. The aluminum honeycombs provide excellent impact resistance in specific impact orientations. However, they provide relatively poor resistance to thermal assault. Finally, the aluminum foams exhibit relatively poor impact energy absorption capacities, significant variability in energy absorption, and limited thermal insulation. The development of the figures of merit examined the response of the materials to the impact event with the intent of maximizing the energy absorption of the materials with respect to either the volume or mass of the materials. Three figures of merit will be presented for the structural response. The figure of merit for the thermal event is based on minimizing the heat flux to the containment boundary. The paper presents a discussion of the test methods, a summary of the data and the figures of merit for each material. (J.P.N.)

  18. Workshop on confidence limits. Proceedings

    International Nuclear Information System (INIS)

    James, F.; Lyons, L.; Perrin, Y.

    2000-01-01

    The First Workshop on Confidence Limits was held at CERN on 17-18 January 2000. It was devoted to the problem of setting confidence limits in difficult cases: number of observed events is small or zero, background is larger than signal, background not well known, and measurements near a physical boundary. Among the many examples in high-energy physics are searches for the Higgs, searches for neutrino oscillations, B s mixing, SUSY, compositeness, neutrino masses, and dark matter. Several different methods are on the market: the CL s methods used by the LEP Higgs searches; Bayesian methods; Feldman-Cousins and modifications thereof; empirical and combined methods. The Workshop generated considerable interest, and attendance was finally limited by the seating capacity of the CERN Council Chamber where all the sessions took place. These proceedings contain all the papers presented, as well as the full text of the discussions after each paper and of course the last session which was a discussion session. The list of participants and the 'required reading', which was expected to be part of the prior knowledge of all participants, are also included. (orig.)

  19. Absolute limit on rotation of gravitationally bound stars

    Science.gov (United States)

    Glendenning, N. K.

    1994-03-01

    The authors seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass-shedding would occur, is 0.33 ms for a M = 1.442 solar mass neutron star (the mass of PSR1913+16). If the limit were found to be broken by any pulsar, it would signal that the confined hadronic phase of ordinary nucleons and nuclei is only metastable.

  20. Numerical Limit Analysis:

    DEFF Research Database (Denmark)

    Damkilde, Lars

    2007-01-01

    Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...... also enabled engineers to solve practical problems within reinforced concrete, steel structures and geotechnics....

  1. Advanced limiters for ISX

    International Nuclear Information System (INIS)

    Mioduszewski, P.K.; Edmonds, P.H.; Sheffield, J.

    1982-01-01

    Continuous removal of heat and particles becomes a vital necessity in future steady-state fusion devices. The pump limiter seems to be an attractive concept to combine these two tasks. On ISX, various schemes of pump limiters are being explored with the final goal to furnish the ISX--C device with a pump limiter to handle heat removal and particle control in steady state. The emphasis of the present paper is on pump limiters based on ballistic particle collection. If this concept turns out to be successful in supplying sufficient pumping efficiency, it may be possible to design pump limiters without a leading edge. Analytical calculations of the particle collection efficiency are given for various limiter configurations. Pumping efficiencies of approximately 4--10%, depending on the specific configuration, seem to be feasible and should be sufficient for steady-state operation. Initial experimental results on pump limiter studies in ISX--B confirm the calculated collection efficiencies. By measuring the ion saturation current to the limiter blade and the pressure buildup simultaneously, we found a correlation between the incident particle flux and the pressure rise that agrees well with a simple model

  2. Limits to Inclusion

    Science.gov (United States)

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  3. Smooth massless limit of field theories

    International Nuclear Information System (INIS)

    Fronsdal, C.

    1980-01-01

    The massless limit of Fierz-Pauli field theories, describing fields with fixed mass and spin interacting with external sources, is examined. Results are obtained for spins, 1, 3/2, 2 and 3 using conventional models, and then for all half-integral spins in a relatively model-independent manner. It is found that the massless limit is smooth provided that the sources satisfy certain conditions. In the massless limit these conditions reduce to the conservation laws required by internal consistency of massless field theory. Smoothness simply requires that quantities that vanish in the massless case approach zero in a certain well-defined manner. (orig.)

  4. Mitigating greenhouse: Limited time, limited options

    International Nuclear Information System (INIS)

    Moriarty, Patrick; Honnery, Damon

    2008-01-01

    Most human-caused climate change comes from fossil fuel combustion emissions. To avoid the risk of serious climate change, very recent research suggests that emission reductions will need to be both large and rapidly implemented. We argue that technical solutions-improving energy efficiency, use of renewable and nuclear energy, and carbon capture and sequestration-can only be of minor importance, mainly given the limited time available to take effective climate action. Only curbing energy use, perhaps through 'social efficiency' gains, particularly in the high-energy consumption countries, can provide the rapid emissions reductions needed. The social efficiency approach requires a basic rethinking in how we can satisfy our human needs with low environmental impacts. Large cuts in emissions could then occur rapidly, but only if resistance to such changes can be overcome. Particularly in transport, there are also serious potential conflicts between the technical and the social efficiency approaches, requiring a choice to be made

  5. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  6. Moving toroidal limiter

    International Nuclear Information System (INIS)

    Ikuta, Kazunari; Miyahara, Akira.

    1983-06-01

    The concept of the limiter-divertor proposed by Mirnov is extended to a toroidal limiter-divertor (which we call moving toroidal limiter) using the stream of ferromagnetic balls coated with a low Z materials such as plastics, graphite and ceramics. An important advantage of the use of the ferromagnetic materials would be possible soft landing of the balls on a catcher, provided that the temperature of the balls is below Curie point. Moreover, moving toroidal limiter would work as a protector of the first wall not only against the vertical movement of plasma ring but also against the violent inward motion driven by major disruption because the orbit of the ball in the case of moving toroidal limiter distributes over the small major radius side of the toroidal plasma. (author)

  7. Automatic identification of mass spectra

    International Nuclear Information System (INIS)

    Drabloes, F.

    1992-01-01

    Several approaches to preprocessing and comparison of low resolution mass spectra have been evaluated by various test methods related to library search. It is shown that there is a clear correlation between the nature of any contamination of a spectrum, the basic principle of the transformation or distance measure, and the performance of the identification system. The identification of functionality from low resolution spectra has also been evaluated using several classification methods. It is shown that there is an upper limit to the success of this approach, but also that this can be improved significantly by using a very limited amount of additional information. 10 refs

  8. Galaxy Masses : A Review

    NARCIS (Netherlands)

    Courteau, Stephane; Cappellari, Michele; Jong, Roelof S. de; Dutton, Aaron A.; Koopmans, L.V.E.

    2013-01-01

    Galaxy masses play a fundamental role in our understanding of structure formation models. This review addresses the variety and reliability of mass estimators that pertain to stars, gas, and dark matter. The dierent sections on masses from stellar populations, dynamical masses of gas-rich and

  9. Neutrino mass matrix and hierarchy

    International Nuclear Information System (INIS)

    Kaus, Peter; Meshkov, Sydney

    2003-01-01

    We build a model to describe neutrinos based on strict hierarchy, incorporating as much as possible, the latest known data, for Δsol and Δatm, and for the mixing angles determined from neutrino oscillation experiments, including that from KamLAND. Since the hierarchy assumption is a statement about mass ratios, it lets us obtain all three neutrino masses. We obtain a mass matrix, Mν and a mixing matrix, U, where both Mν and U are given in terms of powers of Λ, the analog of the Cabibbo angle λ in the Wolfenstein representation, and two parameters, ρ and κ, each of order one. The expansion parameter, Λ, is defined by Λ2 = m2/m3 = √(Δsol/Δatm) ≅ 0.16, and ρ expresses our ignorance of the lightest neutrino mass m1, (m1 ρΛ4m3), while κ scales s13 to the experimental upper limit, s13 = κΛ2 ≅ 0.16κ. These matrices are similar in structure to those for the quark and lepton families, but with Λ about 1.6 times larger than the λ for the quarks and charged leptons. The upper limit for the effective neutrino mass in double β-decay experiments is 4 x 10-3eV if s13 = 0 and 6 x 10-3eV if s13 is maximal. The model, which is fairly unique, given the hierarchy assumption and the data, is compared to supersymmetric extension and texture zero models of mass generation

  10. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    International Nuclear Information System (INIS)

    Batygin, Konstantin; Stevenson, David J.

    2013-01-01

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M ⊕ , multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  11. Food Mass Reduction Trade Study

    Science.gov (United States)

    Perchonok, Michele H.; Stoklosa, Adam M.

    2009-01-01

    Future long duration manned space flights beyond low earth orbit will require the food system to remain safe, acceptable, and nutritious while efficiently balancing appropriate vehicle resources such as mass, volume, power, water, and crewtime. Often, this presents a challenge since maintaining the quality of the food system can result in a higher mass and volume. The Orion vehicle is significantly smaller than the Shuttle vehicle and the International Space Station and the mass and volume available for food is limited. Therefore, the food team has been challenged to reduce the mass of the packaged food from 1.82 kg per person per day to 1.14 kg per person per day. Past work has concentrated on how to reduce the mass of the packaging which contributes to about 15% of the total mass of the packaged food system. Designers have also focused on integrating and optimizing the Orion galley equipment as a system to reduce mass. To date, there has not been a significant effort to determine how to reduce the food itself. The objective of this project is to determine how the mass and volume of the packaged food can be reduced while maintaining caloric and hydration requirements. The following tasks are the key elements to this project: (1) Conduct further analysis of the ISS Standard Menu to determine moisture, protein, carbohydrate, and fat levels. (2) Conduct trade studies to determine how to bring the mass of the food system down. Trade studies may include removing the water of the total food system and/or increasing the fat content. (3) Determine the preferred method for delivery of the new food (e.g. bars, or beverages) and the degree of replacement. (4) Determine whether there are commercially available products that meet the requirements. By the end of this study, an estimate of the mass and volume savings will be provided to the Constellation Program. In addition, if new technologies need to be developed to achieve the mass savings, the technologies, timeline, and

  12. Perturbative current quark masses in QCD

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1982-01-01

    Neutral PCAC current quark masses follow from the covariant light plane of QCD requirement that α-m-circumflex(M), which is not inconsistent with the spontaneous breakdown of chiral symmetry. The resulting current quark mass ratio (m sub(s)/m-circumflex) sub(curr)=5 and scale m-circumflex sub(curr)=62 MeV at M=2 Gev are compatible with the observed πNσ - term, the Goldberger-Treiman discrepancy, the low-lying 0 - , 1/2 + , 1 - , 3/2 + hadron mass spectrum, the flavor independence of the dynamically generated quark mass and the perturbative weak binding limit. (author)

  13. Limits of electrodynamics: paraphotons

    International Nuclear Information System (INIS)

    Okun, L.B.

    1982-01-01

    The paper discusses the accuracy with which electromagnetic interaction is studied at large distances. Possible deviations from standard electrodynamics are investigated. The consideration is carried out the framework of a model which contains two (para) photons, the mass of one of them being non-negligible

  14. Mass formula for quasi-black holes

    International Nuclear Information System (INIS)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-01-01

    A quasi-black hole, either nonextremal or extremal, can be broadly defined as the limiting configuration of a body when its boundary approaches the body's quasihorizon. We consider the mass contributions and the mass formula for a static quasi-black hole. The analysis involves careful scrutiny of the surface stresses when the limiting configuration is reached. It is shown that there exists a strict correspondence between the mass formulas for quasi-black holes and pure black holes. This perfect parallelism exists in spite of the difference in derivation and meaning of the formulas in both cases. For extremal quasi-black holes the finite surface stresses give zero contribution to the total mass. This leads to a very special version of Abraham-Lorentz electron in general relativity in which the total mass has pure electromagnetic origin in spite of the presence of bare stresses.

  15. Pseudoscaler meson masses in the quark model

    International Nuclear Information System (INIS)

    Karl, G.

    1976-10-01

    Pseudoscaler meson masses and sum rules are compared in two different limits of a quark model with 4 quarks. The conventional limit corresponds to a heavy c anti c state and generalizes ideal mixing in a nonet. The second limit corresponds to a missing SU 4 unitary singlet and appears more relevant to the masses of π, K, eta, eta'. If SU 3 is broken only by the mass difference between the strange and nonstrange quarks, the physical masses imply that the u anti u, d anti d and s anti s pairs account only for 33% of the composition of the eta'(960), while for the eta(548) this fraction is 86%. If some of the remaining matter is in the form of the constituents of J/psi, the relative proportion of the relative decays J/psi → eta γ vs J/psi → etaγ is accounted for in satisfactory agreement with experiment. (author)

  16. Limits to fuel/coolant mixing

    International Nuclear Information System (INIS)

    Corradini, M.L.; Moses, G.A.

    1985-01-01

    The vapor explosion process involves the mixing of fuel with coolant prior to the explosion. A number of analysts have identified limits to the amount of fuel/coolant mixing that could occur within the reactor vessel following a core melt accident. Past models are reviewed and a sim plified approach is suggested to estimate the upper limit on the amount of fuel/coolant mixing pos sible. The approach uses concepts first advanced by Fauske in a different way. The results indicat that water depth is an important parameter as well as the mixing length scale D /SUB mix/ , and for large values of D /SUB mix/ the fuel mass mixed is limited to <7% of the core mass

  17. The Origin of Mass

    OpenAIRE

    森岡, 達史

    2013-01-01

    The quark-lepton mass problem and the ideas of mass protection are reviewed. The hierarchy problem and suggestions for its resolution, including Little Higgs models, are discussed. The Multiple Point Principle is introduced and used within the Standard Model to predict the top quark and Higgs particle masses. Mass matrix ans\\"{a}tze are considered; in particular we discuss the lightest family mass generation model, in which all the quark mixing angles are successfully expressed in terms of si...

  18. Neutrino masses and oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A Yu

    1996-11-01

    New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described. Recent results on neutrino mass generation are presented. They include neutrino masses in SO(10) GUT`s and models with anomalous U(1), generation of neutrino mass via neutrino-neutralino mixing, models of sterile neutrino. (author). 95 refs, 9 figs.

  19. Tokamak pump limiters

    International Nuclear Information System (INIS)

    Conn, R.W.

    1984-05-01

    Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6MW of auxiliary neutral beam heating. Experiments have also been done with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a region may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this Z-mode of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described

  20. Tokamak pump limiters

    International Nuclear Information System (INIS)

    Conn, R.W.; California Univ., Los Angeles

    1984-01-01

    Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scrape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this 'Z-mode' of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described. (orig.)

  1. Alienation, Mass Society and Mass Culture.

    Science.gov (United States)

    Dam, Hari N.

    This monograph examines the nature of alienation in mass society and mass culture. Conceptually based on the "Gemeinschaft-Gesellschaft" paradigm of sociologist Ferdinand Tonnies, discussion traces the concept of alienation as it appears in the philosophies of Hegel, Marx, Kierkegaard, Sartre, and others. Dwight Macdonald's "A Theory of Mass…

  2. Novel limiter pump topologies

    International Nuclear Information System (INIS)

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure

  3. Novel limiter pump topologies

    International Nuclear Information System (INIS)

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topologies are suggested which allow high erosion without limiter failure

  4. Imaging in cardiac mass lesions

    International Nuclear Information System (INIS)

    Mundinger, A.; Gruber, H.P.; Dinkel, E.; Geibel, A.; Beck, A.; Wimmer, B.; Schlosser, V.

    1992-01-01

    In 26 patients with cardiac mass lesions confirmed by surgery, diagnostic imaging was performed preoperatively by means of two-dimensional echocardiography (26 patients), angiography (12 patients), correlative computed tomography (CT, 8 patients), and magnetic resonance imaging (MRI, 3 patients). Two-dimensional echocardiography correctly identified the cardiac masses in all patients. Angiography missed two of 12 cardiac masses; CT missed one of eight. MRI identified three of three cardiac masses. Although the sensitivity of two-dimensional echocardiography was high (100%), all methods lacked specificity. None of the methods allowed differentiation between myxoma (n=13) and thrombus (n=7). Malignancy of the lesions was successfully predicted by noninvasive imaging methods in all six patients. However, CT and MRI provided additional information concerning cardiac mural infiltration, pericardial involvement, and extracardiac tumor extension, and should be integrated within a preoperative imaging strategy. Thus two-dimensional echocardiography is the method of choice for primary assessment of patients with suspected cardiac masses. Further preoperative imaging by CT or MRI can be limited to patients with malignancies suspected on the grounds of pericardial effusion or other clinical results. (author)

  5. Constraints on WIMP masses and interactions

    International Nuclear Information System (INIS)

    Enqvist, K.

    1991-01-01

    It is shown that cosmology, experiments and unitarity considerations limit the mass and coupling g' of a generic, heavy WIMP from the above as well as from the below. There are absolute lower limits of 4x10 -5 g and 6x10 -5 g for the couplings of Diracn and Majorana WIMPs, respectively. In U(1)' models cosmology implies an upper limit of about 1 TeV on the Z' and on the WIMP masses, but only in the absence of Z-Z' mixing. (orig.)

  6. HUD Program Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — Income limits used to determine the income eligibility of applicants for assistance under three programs authorized by the National Housing Act. These programs are...

  7. Limited Income and Resources

    Data.gov (United States)

    U.S. Department of Health & Human Services — Information for those with limited income and resources (those who may qualify for or already have the Low Income Subsidy to lower their prescription drug coverage...

  8. SIS - Annual Catch Limit

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Annual Catch Limit (ACL) dataset within the Species Information System (SIS) contains information and data related to management reference points and catch data.

  9. Limited Denial of Participation

    Data.gov (United States)

    Department of Housing and Urban Development — A Limited Denial of Participation (LDP) is an action taken by a HUD Field Office or the Deputy Assistant Secretary for Single Family (DASSF) or Multifamily (DASMF)...

  10. Towards Improved Optical Limiters

    National Research Council Canada - National Science Library

    Huffman, Peter

    2002-01-01

    .... The first approach was to synthesize and study soluble thallium phthalocyanines. Thallium, due to its proximity to lead and indium on the periodic table, should exhibit favorable optical limiting properties...

  11. ACA Federal Upper Limits

    Data.gov (United States)

    U.S. Department of Health & Human Services — Affordable Care Act Federal Upper Limits (FUL) based on the weighted average of the most recently reported monthly average manufacturer price (AMP) for...

  12. HOME Rent Limits

    Data.gov (United States)

    Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...

  13. Limit lines for risk

    International Nuclear Information System (INIS)

    Cox, D.C.; Baybutt, P.

    1982-01-01

    Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

  14. Adjusting estimative prediction limits

    OpenAIRE

    Masao Ueki; Kaoru Fueda

    2007-01-01

    This note presents a direct adjustment of the estimative prediction limit to reduce the coverage error from a target value to third-order accuracy. The adjustment is asymptotically equivalent to those of Barndorff-Nielsen & Cox (1994, 1996) and Vidoni (1998). It has a simpler form with a plug-in estimator of the coverage probability of the estimative limit at the target value. Copyright 2007, Oxford University Press.

  15. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Abstract. Let S be a scheme. Assume that we are given an action of the one dimen- sional split torus Gm,S on a smooth affine S-scheme X. We consider the limit (also called attractor) subfunctor Xλ consisting of points whose orbit under the given action. 'admits a limit at 0'. We show that Xλ is representable by a smooth ...

  16. Safety and design limits

    International Nuclear Information System (INIS)

    Shishkov, L. K.; Gorbaev, V. A.; Tsyganov, S. V.

    2007-01-01

    The paper touches upon the issues of NPP safety ensuring at the stage of fuel load design and operation by applying special limitations for a series of parameters, that is, design limits. Two following approaches are compared: the one used by west specialists for the PWR reactor and the Russian approach employed for the WWER reactor. The closeness of approaches is established, differences that are mainly peculiarities of terms are noted (Authors)

  17. Altruism and Reproductive Limitations

    Directory of Open Access Journals (Sweden)

    Carey J. Fitzgerald

    2009-04-01

    Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

  18. Neutron scattering from a substitutional mass defect

    International Nuclear Information System (INIS)

    Williams, R.D.; Lovesey, S.W.

    1985-06-01

    The dynamic structure factor is calculated for a low concentration of light mass scatterers substituted in a cubic crystal matrix. A new numerical method for the exact calculation is demonstrated. A local density of states for the low momentum transfer limit, and the shifts and widths of the oscillator peaks in the high momentum transfer limit are derived. The limitations of an approximation which decouples the defect from the lattice is discussed. (author)

  19. 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.

  20. Hadronic thermodynamics: Is there a limiting temperature

    International Nuclear Information System (INIS)

    Olive, K.E.

    1984-01-01

    The hadron mass spectrum continues to be a topic of theoretical interest and will remain so until there can be some experimental verification in future heavy ion collisions. There are a variety of models such as the bootstrap, dual, bag etc., which all predict an exponentially rising density of states approx.= exp(m/T 0 ), T 0 approx.=160 MeV. Once one assumes an exponential mass spectrum, one generally finds singularities in thermodynamic quantities and hence possibly a limiting temperature at T 0 . In this talk, I point out some possible ways out of this dilemma. (orig./HSI)

  1. Force Limit System

    Science.gov (United States)

    Pawlik, Ralph; Krause, David; Bremenour, Frank

    2011-01-01

    The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

  2. Theory of limit cycles

    CERN Document Server

    Ye, Yan-Qian; Lo, Chi Y

    1986-01-01

    Over the past two decades the theory of limit cycles, especially for quadratic differential systems, has progressed dramatically in China as well as in other countries. This monograph, updating the 1964 first edition, includes these recent developments, as revised by eight of the author's colleagues in their own areas of expertise. The first part of the book deals with limit cycles of general plane stationary systems, including their existence, nonexistence, stability, and uniqueness. The second section discusses the global topological structure of limit cycles and phase-portraits of quadratic systems. Finally, the last section collects important results that could not be included under the subject matter of the previous two sections or that have appeared in the literature very recently. The book as a whole serves as a reference for college seniors, graduate students, and researchers in mathematics and physics.

  3. Some mass measurement problems

    International Nuclear Information System (INIS)

    Merritt, J.S.

    1976-01-01

    Concerning the problem of determining the thickness of a target, an uncomplicated approach is to measure its mass and area and take the quotient. This paper examines the mass measurement aspect of such an approach. (author)

  4. Biodiesel Mass Transit Demonstration

    Science.gov (United States)

    2010-04-01

    The Biodiesel Mass Transit Demonstration report is intended for mass transit decision makers and fleet managers considering biodiesel use. This is the final report for the demonstration project implemented by the National Biodiesel Board under a gran...

  5. Hadron collider luminosity limitations

    CERN Document Server

    Evans, Lyndon R

    1992-01-01

    The three colliders operated to date have taught us a great deal about the behaviour of both bunched and debunched beams in storage rings. The main luminosity limitations are now well enough understood that most of them can be stronglu attenuated or eliminated by approriate design precautions. Experience with the beam-beam interaction in both the SPS and the Tevatron allow us to predict the performance of the new generation of colliders with some degree of confidence. One of the main challenges that the accelerator physicist faces is the problem of the dynamic aperture limitations due to the lower field quality expected, imposed by economic and other constraints.

  6. SLC kicker magnet limitations

    International Nuclear Information System (INIS)

    Cassel, R.; Donaldson, A.; Mattison, T.; Bowden, G.; Weaver, J.; Bulos, F.; Fiander, D.

    1991-01-01

    The SLC Damping Ring kicker magnets requires a fast magnetic field rise time of 58 nsec, a peak field of 800 gauss, a pulse amplitude stability of 0.01%, and a reasonable operational lifetime. The original kicker magnets designed by SLAC and at Fermi were not able to fulfill the SLC kicker requirements. Extensive studies were conducted to determine the limitation in the magnets, response of the ferrite in kicker magnet, and the modifications needed to improve the kicker magnet performance. The paper details the SLAC and Fermi kicker magnets limitation of performance

  7. Experimental limits from ATLAS on Standard Model Higgs production.

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Experimental limits from ATLAS on Standard Model Higgs production in the mass range 110-600 GeV. The solid curve reflects the observed experimental limits for the production of a Higgs of each possible mass value (horizontal axis). The region for which the solid curve dips below the horizontal line at the value of 1 is excluded with a 95% confidence level (CL). The dashed curve shows the expected limit in the absence of the Higgs boson, based on simulations. The green and yellow bands correspond (respectively) to 68%, and 95% confidence level regions from the expected limits. Higgs masses in the narrow range 123-130 GeV are the only masses not excluded at 95% CL

  8. Mass Customization Measurements Metrics

    DEFF Research Database (Denmark)

    Nielsen, Kjeld; Brunø, Thomas Ditlev; Jørgensen, Kaj Asbjørn

    2014-01-01

    A recent survey has indicated that 17 % of companies have ceased mass customizing less than 1 year after initiating the effort. This paper presents measurement for a company’s mass customization performance, utilizing metrics within the three fundamental capabilities: robust process design, choice...... navigation, and solution space development. A mass customizer when assessing performance with these metrics can identify within which areas improvement would increase competitiveness the most and enable more efficient transition to mass customization....

  9. Radiative Majorana Neutrino Masses

    OpenAIRE

    Hou, Wei-Shu; Wong, Gwo-Guang

    1994-01-01

    We present new radiative mechanisms for generating Majorana neutrino masses, within an extension of the standard model that successfully generates radiative charged lepton masses, order by order, from heavy sequential leptons. Only the new sequential neutral lepton has a right-handed partner, and its Majorana mass provides the seed for Majorana neutrino mass generation. Saturating the cosmological bound of $50$ eV with $m_{\

  10. Holograms for the Masses

    International Nuclear Information System (INIS)

    Newswanger, Craig; Klug, Michael

    2013-01-01

    Traditional holography subject matter has been generally limited to small dead things (SMD). Pulse lasers and the advent of holographic stereography have made it easier to make holograms of scaled objects and those that live (un-SMD), at a cost of single dimensional parallax or monochromaticity. While stunning results have been produced, all of these required access to a lab, expensive lasers and optics, and infinite patience, care and skill to collect and record content. This complexity has generally kept holography out of reach for the masses. The recent introduction of new 3D data sources, free or inexpensive composition and editing software, and fast, consistent print services may make it possible to finally 'democratize' holography, and enable image makers to focus on message rather than medium. This paper will outline several photogrammetry-based methods for producing 3D content for holograms (with a camera and mouse finger), software applications for editing, positioning and lighting, and production means that are usable by anyone, from novice to professional. We will present step-by-step examples and display results depicting various subject matter, from color holographic portraits made from smart phone input to holographic maps made from movies collected with remote control airplanes. The aim is to inspire image making, spontaneity, and maybe even social media-based collaboration to make EVERYONE a holographer.

  11. Asteroids mass determination

    International Nuclear Information System (INIS)

    Hoffmann, M.

    1989-01-01

    Basic methods for asteroid mass determinations and their errors are discussed. New results and some current developments in the astrometric method are reviewed. New methods and techniques, such as electronic imaging, radar ranging and space probes are becoming important for asteroid mass determinations. Mass and density estimations on rotational properties and possible satelites are also discussed

  12. What masses for Cepheids

    International Nuclear Information System (INIS)

    Davis, C.G.

    To understand the evolution of giant stars, it is important to pin down the masses for Cepheids. The 7- to 10-day bump Cepheids imply lower than evolutionary mass (60%). Recent theoretical work, though, indicates that for Cepheids with periods of 15 to 16 days, the best understanding of the light curves results from using evolutionary masses

  13. Activation analysis. Detection limits

    International Nuclear Information System (INIS)

    Revel, G.

    1999-01-01

    Numerical data and limits of detection related to the four irradiation modes, often used in activation analysis (reactor neutrons, 14 MeV neutrons, photon gamma and charged particles) are presented here. The technical presentation of the activation analysis is detailed in the paper P 2565 of Techniques de l'Ingenieur. (A.L.B.)

  14. Thermal background noise limitations

    Science.gov (United States)

    Gulkis, S.

    1982-01-01

    Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

  15. The Copyright Agency Limited.

    Science.gov (United States)

    Morgan, Caroline

    1993-01-01

    The evolution and functions of Australia's Copyright Agency Limited are described. The agency is a copyright collecting organization which collectively administers the rights of authors and publishers whose works are copied in education, and enters into blanket agreements with educational authorities outside the existing statutory license. Some…

  16. Occupational dose equivalent limits

    International Nuclear Information System (INIS)

    Goldfinch, E.P.

    1980-01-01

    This paper considers methods of limiting individual radiation risks by recognizing the variation of risk with age at exposure, taking into account both somatic and genetic risks and proposes a simple formula for controlling individual cumulative exposure and hence risk. (Author)

  17. The Limits of Accountability.

    Science.gov (United States)

    Bailey, Stephen K.

    This discussion, presented at the Regent's Trustees' Conference, February 1973, reviews the limits of accountability in higher education. Managerial efficiency is suggested to assist in eliminating educational and financial waste. This, however, is the secondary concept emphasized. The primary emphasis indicates the legitimacy of the claims that a…

  18. RSMASS: A simple model for estimating reactor and shield masses

    International Nuclear Information System (INIS)

    Marshall, A.C.; Aragon, J.; Gallup, D.

    1987-01-01

    A simple mathematical model (RSMASS) has been developed to provide rapid estimates of reactor and shield masses for space-based reactor power systems. Approximations are used rather than correlations or detailed calculations to estimate the reactor fuel mass and the masses of the moderator, structure, reflector, pressure vessel, miscellaneous components, and the reactor shield. The fuel mass is determined either by neutronics limits, thermal/hydraulic limits, or fuel damage limits, whichever yields the largest mass. RSMASS requires the reactor power and energy, 24 reactor parameters, and 20 shield parameters to be specified. This parametric approach should be applicable to a very broad range of reactor types. Reactor and shield masses calculated by RSMASS were found to be in good agreement with the masses obtained from detailed calculations

  19. Neutrino mass constraints on β decay

    International Nuclear Information System (INIS)

    Ito, Takeyasu M.; Prezeau, Gary

    2005-01-01

    Using the general connection between the upper limit on the neutrino mass and the upper limits on certain types of non-standard-model interactions that can generate loop corrections to the neutrino mass, we derive constraints on some non-standard-model d→ue - ν interactions. When cast into limits on n→pe - ν coupling constants, our results yield constraints on scalar and tensor weak interactions improved by more than an order of magnitude over the current experimental limits. When combined with the existing limits, our results yield vertical bar C S /C V vertical bar or approx. 5x10 -3 , vertical bar C S ' /C V vertical bar or approx. 5x10 -3 , vertical bar C T /C A vertical bar -2 , and vertical bar C T ' /C A vertical bar -2

  20. Limitations on blanket performance

    International Nuclear Information System (INIS)

    Malang, S.

    1999-01-01

    The limitations on the performance of breeding blankets in a fusion power plant are evaluated. The breeding blankets will be key components of a plant and their limitations with regard to power density, thermal efficiency and lifetime could determine to a large degree the attractiveness of a power plant. The performance of two rather well known blanket concepts under development in the frame of the European Blanket Programme is assessed and their limitations are compared with more advanced (and more speculative) concepts. An important issue is the question of which material (structure, breeder, multiplier, coatings) will limit the performance and what improvement would be possible with a 'better' structural material. This evaluation is based on the premise that the performance of the power plant will be limited by the blankets (including first wall) and not by other components, e.g. divertors, or the plasma itself. However, the justness of this premise remains to be seen. It is shown that the different blanket concepts cover a large range of allowable power densities and achievable thermal efficiencies, and it is concluded that there is a high incentive to go for better performance in spite of possibly higher blanket cost. However, such high performance blankets are usually based on materials and technologies not yet developed and there is a rather high risk that the development could fail. Therefore, it is explained that a part of the development effort should be devoted to concepts where the materials and technologies are more or less in hand in order to ensure that blankets for a DEMO reactor can be developed and tested in a given time frame. (orig.)

  1. TRAIL: a tokamak rail gun limiter

    International Nuclear Information System (INIS)

    Yu, W.S.; Powell, J.R.; Usher, J.L.

    1980-01-01

    An attractive new limiter concept is investigated. The TRAIL (Tokamak Rail Gun Limiter) system impacts a stream of moderate velocity pellets (100 to 200 m/sec through the plasma edge region to absorb energy and define the plasma boundary. The pellets are recycled after cooling, to the injector of an E-M mass accelerator. Heat fluxes of approx. 30,000 W/cm 2 can be readily accommodated by the pellets, with very low recirculating power requirements (approx. 0.1%) for the accelerator. The mass accelerator velocity requirements are well within the present state of the art (several Km/sec). Accelerators injecting pellets at approx. 1 Km/sec can be used to control local plasma temperature and current profiles and to act as energy absorbers to shut down the plasma without damage to the first wall if a plasma disruption occurs

  2. On Defining Mass

    Science.gov (United States)

    Hecht, Eugene

    2011-01-01

    Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement surrounding the Large Hadron Collider at CERN is associated with discovering the mechanism responsible for the masses of the elementary particles. This paper will first briefly examine the leading definitions, pointing out their shortcomings. Then, utilizing relativity theory, it will propose—for consideration by the community of physicists—a conceptual definition of mass predicated on the more fundamental concept of energy, more fundamental in that everything that has mass has energy, yet not everything that has energy has mass.

  3. The Point Mass Concept

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2011-04-01

    Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the spec- ulation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

  4. The Point Mass Concept

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2011-04-01

    Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the speculation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

  5. W mass and W asymmetry at CDF

    International Nuclear Information System (INIS)

    Leone, S.

    1991-05-01

    The lepton charge asymmetry from W decaying into a lepton and a neutrino is discussed (preliminary result). This measurement gives information on parton distribution functions at low x values. The derivation of the recently published W mass value of 79.91 ± 0.39 GeV/c 2 is also presented. M W is used to set an upper limit on the top quark mass. 13 refs., 4 figs., 1 tab

  6. Scalar field mass in generalized gravity

    International Nuclear Information System (INIS)

    Faraoni, Valerio

    2009-01-01

    The notions of mass and range of a Brans-Dicke-like scalar field in scalar-tensor and f(R) gravity are subject to an ambiguity that hides a potential trap. We spell out this ambiguity and identify a physically meaningful and practical definition for these quantities. This is relevant when giving a mass to this scalar in order to circumvent experimental limits on the PPN parameters coming from solar system experiments.

  7. Polymer and Additive Mass Spectrometry Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-06

    The use of mass spectrometry in fields related to polymers has increased significantly over the past three decades and will be explored in this literature review. The importance of this technique is highlighted when exploring how polymers degrade, verifying purchased materials, and as internal requirements change. The primary focus will be on four ionization techniques and the triple quadrupole and quadrupole / time-of-flight mass spectrometers. The advantages and limitations of each will also be explored.

  8. Age Limit of Pediatrics.

    Science.gov (United States)

    Hardin, Amy Peykoff; Hackell, Jesse M

    2017-09-01

    Pediatrics is a multifaceted specialty that encompasses children's physical, psychosocial, developmental, and mental health. Pediatric care may begin periconceptionally and continues through gestation, infancy, childhood, adolescence, and young adulthood. Although adolescence and young adulthood are recognizable phases of life, an upper age limit is not easily demarcated and varies depending on the individual patient. The establishment of arbitrary age limits on pediatric care by health care providers should be discouraged. The decision to continue care with a pediatrician or pediatric medical or surgical subspecialist should be made solely by the patient (and family, when appropriate) and the physician and must take into account the physical and psychosocial needs of the patient and the abilities of the pediatric provider to meet these needs. Copyright © 2017 by the American Academy of Pediatrics.

  9. FTU pump limiter

    International Nuclear Information System (INIS)

    Alessandrini, C.; Ciotti, M.; Mattei, A. De; Maddaluno, G.; Mazzitelli, G.

    1989-01-01

    The control of the refuelling and recycling of the plasma is crucial in providing enhanced performances in tokamaks and steady-state operation in future reactors. In this paper, we report details of the design and analysis for the pump limiter to be incorporated into the FTU tokamak. The FTU, presently under commissioning, is a compact high field (B=8T), medium high density, circular cross section machine with small accesses. The dimensions of the equatorial port (width 8 cm) would reduce the length of the entrance throat to a few centimeters, which is unacceptable for efficient particle trapping. We have, therefore, designed a rotating blade of the pump limiter head that, in the working position, extends in the toroidal direction inside the vacuum chamber. (author) 8 refs., 4 figs

  10. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  11. Imaging Mass Spectrometry in Neuroscience

    Science.gov (United States)

    2013-01-01

    Imaging mass spectrometry is an emerging technique of great potential for investigating the chemical architecture in biological matrices. Although the potential for studying neurobiological systems is evident, the relevance of the technique for application in neuroscience is still in its infancy. In the present Review, a principal overview of the different approaches, including matrix assisted laser desorption ionization and secondary ion mass spectrometry, is provided with particular focus on their strengths and limitations for studying different neurochemical species in situ and in vitro. The potential of the various approaches is discussed based on both fundamental and biomedical neuroscience research. This Review aims to serve as a general guide to familiarize the neuroscience community and other biomedical researchers with the technique, highlighting its great potential and suitability for comprehensive and specific chemical imaging. PMID:23530951

  12. Ion detection in mass spectrometry

    International Nuclear Information System (INIS)

    Bolbach, Gerard

    2016-03-01

    This course aims at providing some elements for a better understanding of ion detectors used in mass spectrometers, of their operations, and of their limitations. A first part addresses the functions and properties of an ideal detector, how to detect ions in gas phase, and particle detectors and ion detectors used in mass spectrometry. The second part proposes an overview of currently used detectors with respect to their operation principle: detection from the ion charge (Faraday cylinder), detection by inductive effects (FTICR, Fourier Transform Ion Cyclotron Resonance), and detection by secondary electron emission. The third part discusses the specificities of secondary electron emission. The fourth one addresses operating modes and parameters related to detectors. The sixth part proposes a prospective view on future detectors by addressing the following issues: cryo-detector, inductive effect and charge detectors, ion detection and nano materials

  13. Direct measurements of neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1991-01-01

    Some recent developments in the experimental search for neutrino mass are discussed. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 9.3 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a ''model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. Hime and Jelley report finding new evidence for a 17-keV neutrino in the Β decay of 35 S and 63 Ni. Many other experiments are being reported and the situation is still unresolved. 56 refs., 1 fig., 3 tabs

  14. Are Limit Orders Rational?

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Martin

    2007-01-01

    Roč. 14, č. 4 (2007), s. 32-38 ISSN 0572-3043 R&D Projects: GA ČR(CZ) GA402/06/1417; GA ČR GA402/04/1294; GA ČR GD402/03/H057 Institutional research plan: CEZ:AV0Z10750506 Keywords : market microstructure * limit order market * portfolio selection Subject RIV: AH - Economics

  15. INAA - application and limitation

    International Nuclear Information System (INIS)

    Heydorn, K.

    1990-01-01

    The uncertainties associated with performing Instrumental Neutron Activation Analysis (INAA) are discussed in relation to their category. The Comite International de Poids et Mesure (CIPM) distinguishes between uncertainties according to how their contribution to the overall uncertainty is evaluated. INAA is a potentially definitive method, if all sources of uncertainty can be accounted for. The limitation of the method is reached when uncertainties, which cannot be accounted for, assume significance, and the method cannot be brought in statistical control. (orig.)

  16. Density limits in Tokamaks

    International Nuclear Information System (INIS)

    Tendler, M.

    1984-06-01

    The energy loss from a tokamak plasma due to neutral hydrogen radiation and recycling is of great importance for the energy balance at the periphery. It is shown that the requirement for thermal equilibrium implies a constraint on the maximum attainable edge density. The relation to other density limits is discussed. The average plasma density is shown to be a strong function of the refuelling deposition profile. (author)

  17. Photovoltaic energy cost limit

    International Nuclear Information System (INIS)

    Coiante, D.

    1992-01-01

    Referring to a photovoltaic system for grid connected applications, a parametric expression of kWh cost is derived. The limit of kWh cost is carried out extrapolating the values of cost components to their lowest figure. The reliability of the forecast is checked by disaggregating kWh cost in direct and indirect costs and by discussing the possible cost reduction of each component

  18. Heat flux limiting sleeves

    Science.gov (United States)

    Harris, William G.

    1985-01-01

    A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

  19. Superconductive AC current limiter

    International Nuclear Information System (INIS)

    Bekhaled, M.

    1987-01-01

    This patent describes an AC current limiter for a power transport line including a power supply circuit and feeding a load circuit via an overload circuit-breaker member. The limiter comprises a transformer having a primary winding connected in series between the power supply circuit and the load circuit and at least one secondary winding of superconductor material contained in a cryogenic enclosure and short-circuited on itself. The leakage reactance of the transformer as seen from the primary winding is low, and the resistance of the at least one secondary winding when in the non-superconducting state and as seen from the primary is much greater than the nominal impedance of the transformer. The improvement whereby the at least one secondary winding of the transformer comprises an active winding in association with a set of auxiliary windings. The set of auxiliary windings is constituted by an even number of series-connected auxiliary windings wound in opposite directions, with the total number of turns in one direction being equal to the total number of turns in the opposite direction, and with the thermal capacity of the secondary winding as a whole being sufficiently high to limit the expansion thereof to a value which remains small during the time it takes the circuit-breaking member to operate

  20. Indigenously built resonance ionization mass spectrometer

    International Nuclear Information System (INIS)

    Razvi, M.A.N.; Jayasekharan, T.; Thankarajan, K.; Guhagarkar, M.B.; Dixit, M.N.; Bhale, G.L.

    2000-04-01

    Design, fabrication and performance testing of an indigenously built Resonance Ionization Mass Spectrometer (RIMS) is presented in this report. The instrument is totally indigenous, but for the laser components consisting of the excimer laser and tunable dye lasers. Constructional details of atomic beam source and linear time-of-flight mass spectrometer are included. Finally, commissioning and performance testing of the instrument is described. Mass resolving power of 400 and a detection limit of 100 atoms has been achieved using this RIMS set-up. (author)

  1. A weight limit emerges for neutron stars

    Science.gov (United States)

    Cho, Adrian

    2018-02-01

    Astrophysicists have long wondered how massive a neutron star—the corpse of certain exploding stars—could be without collapsing under its own gravity to form a black hole. Now, four teams have independently deduced a mass limit for neutron stars of about 2.2 times the mass of the sun. To do so, all four groups analyzed last year's blockbuster observations of the merger of two neutron stars, spied on 17 September 2017 by dozens of observatories. That approach may seem unpromising, as it might appear that the merging neutron stars would have immediately produced a black hole. However, the researchers argue that the merger first produced a spinning, overweight neutron star momentarily propped up by centrifugal force. They deduce that just before it collapsed, the short-lived neutron star had to be near the maximum mass for one spinning as a solid body. That inference allowed them to use a scaling relationship to estimate the maximum mass of a nonrotating, stable neutron star, starting from the total mass of the original pair and the amount of matter spewed into space.

  2. Protein Analysis by Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Cindic, M.

    2008-04-01

    Full Text Available Soft ionization techniques, electrospray (ESI and matrix-assisted laser desorption/ionization (MALDI make the analysis of biomolecules by mass spectrometry (MS possible. MS is used for determination of the molecular weight of peptides and protein, sequence analysis, characterization of protein-ligand interactions etc. The detection limit, resolution and mass accuracy depend on instrument used (Table 1. Impurities (buffers, salts, detergents can reduce the ion intensities or even totally suppress them, so a separation method (chromatography, 2D-gel electrophoresis must be used for purification of the sample.Molecular mass of intact protein can be determined by ESI or MALDI MS. Multiply charged ions are produced by ESI MS, while singly charged ions are predominant in MALDI spectra (Fig. 2.Sequence analysis of proteins by MS can be performed using peptide mass fingerprint. In this method, proteins are separated by 2-D gel electrophoresis and digested with specific protease (Table 2 or digested and then separated by two-dimensional chromatography (Fig. 1. The obtained peptide mixtures are analyzed by MS or MALDI-TOF technique. The masses determined by MS are compared with calculated masses from database entries. Different algorithms have been developed for protein identification. Example of posttranslational modifications (N- and O-glycosylation and protein sequence complex analysis after dual digestion (endoproteinase digestion followed by endoglycosidase digestion is shown in Fig. 3.It is known that detection of peptides by MS is influenced by intrinsic properties like amino acid composition, the basicity of the C-terminal amino acid, hydrophobicity, etc. Arginine-containing peptides dominate in MS spectra of tryptic digest, so the chemical derivatization of lysine terminal residue by O-methilisourea or 2-methoxy-4,5-1H-imidazole was suggested (Fig. 4.The peptide mass fingerprint method can be improved further by peptide fragmentation using tandem

  3. Dijet invariant mass spectrum at CDF

    International Nuclear Information System (INIS)

    Incagli, M.

    1992-11-01

    A summary of QCD results obtained using the dijet invariant mass spectrum dσ/dM jj is presented. The spectrum is compared with QCD Leader Order and with the recently published Next to Leading Order calculations. A limit on the scale of an eventual quark compositness can be set at Λ=1300 GeV. Limits on the production of new particles, decaying hadronically, are presented, too. Axigluons are ruled out in the mass range [240, 640] GeV, for a theory with N=10 strong interacting fermions, and in the two windows [260, 280] GeV and [450, 550] GeV, for N=20

  4. Principle of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Matsuzaki, Hiroyuki

    2007-01-01

    The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

  5. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/pram/077/01/0213-0226. Keywords. White dwarfs; Chandrasekhar limit; relativistic degeneracy. Abstract. Subrahmanyan Chandrasekhar, known simply as Chandra in the scientific world, is one of the foremost scientists of the 20th century. In celebrating his birth centenary, ...

  6. Strategic arms limitation

    Science.gov (United States)

    Allen Greb, G.; Johnson, Gerald W.

    1983-10-01

    Following World War II, American scientists and politicians proposed in the Baruch plan a radical solution to the problem of nuclear weapons: to eliminate them forever under the auspices of an international nuclear development authority. The Soviets, who as yet did not possess the bomb, rejected this plan. Another approach suggested by Secretary of War Henry Stimson to negotiate directly with the Soviet Union was not accepted by the American leadership. These initial arms limitation failures both reflected and exacerbated the hostile political relationship of the superpowers in the 1950s and 1960s. Since 1969, the more modest focus of the Soviet-American arms control process has been on limiting the numbers and sizes of both defensive and offensive strategic systems. The format for this effort has been the Strategic Arms Limitatins Talks (Salt) and more recently the Strategic Arms Reduction Talks (START). Both sides came to these negotiations convinced that nuclear arsenals had grown so large that some for of mutual restraint was needed. Although the SALT/START process has been slow and ponderous, it has produced several concrete the agreements and collateral benefits. The 1972 ABM Treaty restricts the deployment of ballistic missile defense systems, the 1972 Interim Agreement places a quantitative freeze on each side's land based and sea based strategic launchers, and the as yet unratified 1979 SALT II Treaty sets numerical limits on all offensive strategic systems and sublimits on MIRVed systems. Collateral benefits include improved verification procedures, working definitions and counting rules, and permanent bureaucratic apparatus which enhance stability and increase the chances for achieving additional agreements.

  7. Is Mass Customization Sustainable?

    DEFF Research Database (Denmark)

    Petersen, Thomas Ditlev; Jørgensen, Kaj Asbjørn; Nielsen, Kjeld

    2011-01-01

    Mass customizers are like other companies currently experiencing an increasing customer demand for environmentally sustainable products as well as an increasingly strict legislation regarding environmental sustainability. This paper addresses the issue whether the concepts mass customization...... and sustainability are fundamentally compatible by asking the question: can a mass customized product be sustainable? Several factors could indicate that mass customized products are less sustainable than standardized products; however other factors suggest the opposite. This paper explores these factors during...... three life cycle phases for a product: Production, Use and End of Life. It is concluded that there is not an unambiguous causal relationship between mass customization and sustainability; however several factors unique to mass customized products are essential to consider during product and process...

  8. Main sequence mass loss

    International Nuclear Information System (INIS)

    Brunish, W.M.; Guzik, J.A.; Willson, L.A.; Bowen, G.

    1987-01-01

    It has been hypothesized that variable stars may experience mass loss, driven, at least in part, by oscillations. The class of stars we are discussing here are the δ Scuti variables. These are variable stars with masses between about 1.2 and 2.25 M/sub θ/, lying on or very near the main sequence. According to this theory, high rotation rates enhance the rate of mass loss, so main sequence stars born in this mass range would have a range of mass loss rates, depending on their initial rotation velocity and the amplitude of the oscillations. The stars would evolve rapidly down the main sequence until (at about 1.25 M/sub θ/) a surface convection zone began to form. The presence of this convective region would slow the rotation, perhaps allowing magnetic braking to occur, and thus sharply reduce the mass loss rate. 7 refs

  9. Beta limits for ETF

    International Nuclear Information System (INIS)

    Helton, F.J.; Miller, R.L.

    1982-01-01

    ETF (Engineering Test Facility) one-dimensional transport simulations indicate that a volume-average beta of 4% is required for ignition. It is therefore important that theoretical beta limits, determined by requiring equilibria to be stable to all ideal modes, exceed 4%. This paper documents an ideal MHD analysis wherein it is shown that, with appropriate plasma cross-sectional shape and current profile optimization, operation near 5% is possible. The critical beta value, however, depends on the functional form used for ff', which suggests that higher critical betas could be achieved by directly optimizing the safety factor profile. (author)

  10. Limitations of Boltzmann's principle

    International Nuclear Information System (INIS)

    Lavenda, B.H.

    1995-01-01

    The usual form of Boltzmann's principle assures that maximum entropy, or entropy reduction, occurs with maximum probability, implying a unimodal distribution. Boltzmann's principle cannot be applied to nonunimodal distributions, like the arcsine law, because the entropy may be concave only over a limited portion of the interval. The method of subordination shows that the arcsine distribution corresponds to a process with a single degree of freedom, thereby confirming the invalidation of Boltzmann's principle. The fractalization of time leads to a new distribution in which arcsine and Cauchy distributions can coexist simultaneously for nonintegral degrees of freedom between √2 and 2

  11. Fault current limiter

    Science.gov (United States)

    Darmann, Francis Anthony

    2013-10-08

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  12. Dose. Detriment. Limit assessment

    International Nuclear Information System (INIS)

    Breckow, J.

    2015-01-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  13. Marketing with limited budget

    OpenAIRE

    Smirnova, Daria

    2017-01-01

    The purpose of this research-based thesis was to get an idea how managers of two small resembling hotels of a specific region deal with marketing process with a limited budget. In addition, the aim of the thesis was to examine if hotel managers who were interviewed perceive marketing only in the way of ‘promotion’ rather than marketing research, marketing mix and marketing environment theories. It was also found out if hotel managers of those hotels consider marketing as a key to successful h...

  14. Limitation of Auditors' Liability

    DEFF Research Database (Denmark)

    Werlauff, Erik; Foged-Ladefoged, Lise Kolding

    2014-01-01

    The article examines the question of whether rules on the limitation of auditors’ liability within the perspective of EU law are needed, and if so, which rules can provide an appropriate balance between the potential injured party’s interests and those of the auditing sector, including with respect...... to the fact that the insurance premiums associated with an unlimited liability must of course make the auditor’s tasks more expensive. Relevant EU recommendations and a comparative glance at other EU countries’ proposed solutions to the problem are included....

  15. MassTRIX: mass translator into pathways.

    Science.gov (United States)

    Suhre, Karsten; Schmitt-Kopplin, Philippe

    2008-07-01

    Recent technical advances in mass spectrometry (MS) have brought the field of metabolomics to a point where large numbers of metabolites from numerous prokaryotic and eukaryotic organisms can now be easily and precisely detected. The challenge today lies in the correct annotation of these metabolites on the basis of their accurate measured masses. Assignment of bulk chemical formula is generally possible, but without consideration of the biological and genomic context, concrete metabolite annotations remain difficult and uncertain. MassTRIX responds to this challenge by providing a hypothesis-driven approach to high precision MS data annotation. It presents the identified chemical compounds in their genomic context as differentially colored objects on KEGG pathway maps. Information on gene transcription or differences in the gene complement (e.g. samples from different bacterial strains) can be easily added. The user can thus interpret the metabolic state of the organism in the context of its potential and, in the case of submitted transcriptomics data, real enzymatic capacities. The MassTRIX web server is freely accessible at http://masstrix.org.

  16. Glycomics using mass spectrometry

    OpenAIRE

    Wuhrer, Manfred

    2013-01-01

    Mass spectrometry plays an increasingly important role in structural glycomics. This review provides an overview on currently used mass spectrometric approaches such as the characterization of glycans, the analysis of glycopeptides obtained by proteolytic cleavage of proteins and the analysis of glycosphingolipids. The given examples are demonstrating the application of mass spectrometry to study glycosylation changes associated with congenital disorders of glycosylation, lysosomal storage di...

  17. Mass spectrometry in oceanography

    International Nuclear Information System (INIS)

    Aggarwal, Suresh K.

    2000-01-01

    Mass spectrometry plays an important role in oceanography for various applications. Different types of inorganic as well as organic mass spectrometric techniques are being exploited world-wide to understand the different aspects of marine science, for palaeogeography, palaeoclimatology and palaeoecology, for isotopic composition and concentrations of different elements as well as for speciation studies. The present paper reviews some of the applications of atomic mass spectrometric techniques in the area of oceanography

  18. Large mass storage facility

    International Nuclear Information System (INIS)

    Peskin, A.M.

    1978-01-01

    The report of a committee to study the questions surrounding possible acquisition of a large mass-storage device is presented. The current computing environment at BNL and justification for an online large mass storage device are briefly discussed. Possible devices to meet the requirements of large mass storage are surveyed, including future devices. The future computing needs of BNL are prognosticated. 2 figures, 4 tables

  19. The origin of mass

    International Nuclear Information System (INIS)

    Cashmore, R.; Sutton, C.

    1992-01-01

    The existence of mass in the Universe remains unexplained but recent high-energy experiments, described in this article, are close to testing the most plausible explanation for the masses of fundamental particles, which may, in turn, lead to a clearer understanding of mass on the macro-scale. The Standard Model includes the concept of the Higgs mechanism which endows particles with mass. Actual evidence for the existence of the postulated particle known as the Higgs boson would lead to confirmation of the theory and efforts to detect it at CERN are complex and determined. (UK)

  20. MassAI

    DEFF Research Database (Denmark)

    2011-01-01

    A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX.......A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX....

  1. Masses of Cepheids

    International Nuclear Information System (INIS)

    Fox, A.N.

    1980-01-01

    About ten years ago it became apparent that the masses of Cepheids predicted from the theory of stellar evolution were larger than those predicted by pulsation theory. This mass anomaly for the classical Cepheids was displayed by Christy (1968) and Stobie (1969a,b,c) using nonlinear hydrodynamic calculations and by Cogan (1970) using linear theory. Rodgers (1970) has also discussed the several mass anomalies in some detail. These mass anomalies, and some others to be discussed, have not yet been completely resolved, but many of the discrepancies have been alleviated mostly by an increase in the Cepheid luminosities and a decrease in their surface temperatures

  2. Limits to biofuels

    Directory of Open Access Journals (Sweden)

    Johansson S.

    2013-06-01

    Full Text Available Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays’ use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years’ agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2–6000TWh (biogas from residues and waste and ethanol from woody biomass in the more optimistic cases.

  3. Limits to biofuels

    Science.gov (United States)

    Johansson, S.

    2013-06-01

    Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays' use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years' agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2-6000TWh (biogas from residues and waste and ethanol from woody biomass) in the more optimistic cases.

  4. (Limiting the greenhouse effect)

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  5. Limitations of inclusive fitness.

    Science.gov (United States)

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.

  6. The limitation and modification of flux-limited diffusion theory

    International Nuclear Information System (INIS)

    Liu Chengan; Huang Wenkai

    1986-01-01

    The limitation of various typical flux-limited diffusion theory and advantages of asymptotic diffusion theory with time absorption constant are analyzed and compared. The conclusions are as following: Though the flux-limited problem in neutron diffusion theory are theoretically solved by derived flux-limited diffusion equation, it's going too far to limit flux due to the inappropriate assumption in deriving flux-limited diffusion equation. The asymptotic diffusion theory with time absorption constant has eliminated the above-mentioned limitation, and it is more accurate than flux-limited diffusion theory in describing neutron transport problem

  7. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    as delivered stainless steel surfaces implying microstructure changes in terms of larger ratio of closed lubricant pockets due to selective grain boundary etching. Strategic surfaces have also been created by macroscopic texturing using spherical indentations having a very small edge slope in order to promote...... by strategic surfaces in comparison to normal stainless steel surfaces implying a larger extent of bi-axial stretching. Numerical simulations have been applied in order to evaluate limits of lubrication in the simulative strip reduction based on predictions of critical parameters appearing in terms......-models corresponds well to experimental results in terms of lubricant film breakdown and subsequently pick-up development. Punching and blanking have been investigated regarding tribological conditions in case of using stainless steel workpiece materials. However, this has called for development of a new test method...

  8. Personal Freedom beyond Limits

    Directory of Open Access Journals (Sweden)

    Juan Fernando Sellés

    2013-07-01

    Full Text Available In this work we distinguish between freedom in the human manifestations (intelligence, will,actions and personal freedom in the personal intimacy. This second is beyond the freedom reached bythe classic and modern thought, since it takes root in the personnel act of being. Because of it, it is not possible to characterize this freedom like the classic description as ‘domain over the own acts’, becauseit is a description of ‘categorial’ order; neither like present day ‘autonomy’ or ‘independence’, becausethe existence of one person alone is impossible, since ‘person’ means relation, personal free openingto other persons, description of the ‘transcendental’ order and, therefore, to the margin of limits.

  9. [Does medicine limit enlightenment?].

    Science.gov (United States)

    Schipperges, H

    1977-01-01

    In the first, historical part the most important programs of "Medical Enlightenment", are pointed out, beginning with Leibniz, followed by the public health movement of the 18th century, up to the time of Immanuel Kant. Based on this historical background several concepts of a "Medical Culture" are analysed in detail, for instance the "Theorie einer Medizinal-Ordnung" by Johann Benjamin Ehrhard (1800), the "Medicinische Reform" by Rudolf Virchow (1848) and the programs of the "Gesellschaft Deutscher Naturforscher und Arzte" (about 1850-1890), the latter bearing both scientific and political character. Following the historical part, the question is raised whether "Enlightenment" is limited by medicine and whether medicine is able to provide a program for individual health education resulting in a more cultivated style of private life, and lastly how this might be realized.

  10. The Limits to Relevance

    Science.gov (United States)

    Averill, M.; Briggle, A.

    2006-12-01

    Science policy and knowledge production lately have taken a pragmatic turn. Funding agencies increasingly are requiring scientists to explain the relevance of their work to society. This stems in part from mounting critiques of the "linear model" of knowledge production in which scientists operating according to their own interests or disciplinary standards are presumed to automatically produce knowledge that is of relevance outside of their narrow communities. Many contend that funded scientific research should be linked more directly to societal goals, which implies a shift in the kind of research that will be funded. While both authors support the concept of useful science, we question the exact meaning of "relevance" and the wisdom of allowing it to control research agendas. We hope to contribute to the conversation by thinking more critically about the meaning and limits of the term "relevance" and the trade-offs implicit in a narrow utilitarian approach. The paper will consider which interests tend to be privileged by an emphasis on relevance and address issues such as whose goals ought to be pursued and why, and who gets to decide. We will consider how relevance, narrowly construed, may actually limit the ultimate utility of scientific research. The paper also will reflect on the worthiness of research goals themselves and their relationship to a broader view of what it means to be human and to live in society. Just as there is more to being human than the pragmatic demands of daily life, there is more at issue with knowledge production than finding the most efficient ways to satisfy consumer preferences or fix near-term policy problems. We will conclude by calling for a balanced approach to funding research that addresses society's most pressing needs but also supports innovative research with less immediately apparent application.

  11. Cyclotrons as mass spectrometers

    International Nuclear Information System (INIS)

    Clark, D.J.

    1984-04-01

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures

  12. ABSOLUTE NEUTRINO MASSES

    DEFF Research Database (Denmark)

    Schechter, J.; Shahid, M. N.

    2012-01-01

    We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos.......We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos....

  13. Systematics of quark mass

    International Nuclear Information System (INIS)

    Frampton, P.H.; Jarlskog, C.

    1985-01-01

    It is shown that the quark mass matrices in the Standard Electroweak Model satisfy the empirical relation M = M 1 + Ψ(Λ 2 ), where M(M sp (')) refers to the mass matrix of the charge 2/3(-1/3) quarks normalized to the largest eigenvalue, m sub (t)(m sub (b)), and Λ = V sub (us) = 0.22

  14. The Origin of Mass

    Energy Technology Data Exchange (ETDEWEB)

    Giese, Albrecht

    2010-07-01

    The world of physics presently looks to the LHC (CERN), where many expect the Higgs boson to be found. The Higgs is supposed to (partly) explain the cause of mass. There are indications that neither the Higgs nor Supersymmetric Particles will be found. In order to understand mass, the Higgs is not needed. Inertial mass is caused by a fundamental process. Binding fields propagate at the finite speed of light. An inevitable consequence is that every expanded object has an inertial behaviour, even if the constituents of the object are mass-less. To explain the mass of elementary particles, we have to accept that these particles are expanded. This is on the one hand in conflict with the concept of present physics; on the other hand it is in no conflict with any experiment. And it conforms to the analysis of Schroedinger with respect to the Dirac function of the electron. The corresponding particle model explains particle properties, like the magnetic moment (and therefore also the Bohr Magneton) and the constancy of the spin, correctly without any use of QM. Also the dynamic properties of mass, i.e. the relativistic increase of mass at motion and the mass-energy-relation, follow in a straight way from this concept.

  15. Mass spectrometers in medicine

    International Nuclear Information System (INIS)

    Bushman, J.A.

    1975-01-01

    This paper describes how the mass spectrometer enables true lung function, namely the exchange of gases between the environment and the organism, to be measured. This has greatly improved the understanding of respiratory disease and the latest generation of respiratory mass spectrometers will do much to increase the application of the technique. (author)

  16. Mass of AC Andromedae

    International Nuclear Information System (INIS)

    King, D.S.; Cox, A.N.; Hodson, S.W.

    1975-01-01

    Calculations indicate that AC Andromedae is population I rather than population II. A mass and radius for this star are calculated using a new set of opacities for the Kippenhahn Ia mixture. It is concluded that the mass is too high for an ordinary RR Lyrae star. (BJG)

  17. Mass preserving image registration

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Sporring, Jon; Lo, Pechin Chien Pau

    2010-01-01

    The paper presents results the mass preserving image registration method in the Evaluation of Methods for Pulmonary Image Registration 2010 (EMPIRE10) Challenge. The mass preserving image registration algorithm was applied to the 20 image pairs. Registration was evaluated using four different...

  18. Elbow mass flow meter

    Science.gov (United States)

    McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

    1994-08-16

    The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

  19. Flavor symmetries and fermion masses

    International Nuclear Information System (INIS)

    Rasin, A.

    1994-04-01

    We introduce several ways in which approximate flavor symmetries act on fermions and which are consistent with observed fermion masses and mixings. Flavor changing interactions mediated by new scalars appear as a consequence of approximate flavor symmetries. We discuss the experimental limits on masses of the new scalars, and show that the masses can easily be of the order of weak scale. Some implications for neutrino physics are also discussed. Such flavor changing interactions would easily erase any primordial baryon asymmetry. We show that this situation can be saved by simply adding a new charged particle with its own asymmetry. The neutrality of the Universe, together with sphaleron processes, then ensures a survival of baryon asymmetry. Several topics on flavor structure of the supersymmetric grand unified theories are discussed. First, we show that the successful predictions for the Kobayashi-Maskawa mixing matrix elements, V ub /V cb = √m u /m c and V td /V ts = √m d /m s , are a consequence of a large class of models, rather than specific properties of a few models. Second, we discuss how the recent observation of the decay β → sγ constrains the parameter space when the ratio of the vacuum expectation values of the two Higgs doublets, tanΒ, is large. Finally, we discuss the flavor structure of proton decay. We observe a surprising enhancement of the branching ratio for the muon mode in SO(10) models compared to the same mode in the SU(5) model

  20. Upper bounds on superpartner masses from upper bounds on the Higgs boson mass.

    Science.gov (United States)

    Cabrera, M E; Casas, J A; Delgado, A

    2012-01-13

    The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanβ, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11)  GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.

  1. Miniature mass analyzer

    CERN Document Server

    Cuna, C; Lupsa, N; Cuna, S; Tuzson, B

    2003-01-01

    The paper presents the concept of different mass analyzers that were specifically designed as small dimension instruments able to detect with great sensitivity and accuracy the main environmental pollutants. The mass spectrometers are very suited instrument for chemical and isotopic analysis, needed in environmental surveillance. Usually, this is done by sampling the soil, air or water followed by laboratory analysis. To avoid drawbacks caused by sample alteration during the sampling process and transport, the 'in situ' analysis is preferred. Theoretically, any type of mass analyzer can be miniaturized, but some are more appropriate than others. Quadrupole mass filter and trap, magnetic sector, time-of-flight and ion cyclotron mass analyzers can be successfully shrunk, for each of them some performances being sacrificed but we must know which parameters are necessary to be kept unchanged. To satisfy the miniaturization criteria of the analyzer, it is necessary to use asymmetrical geometries, with ion beam obl...

  2. Proton mass decomposition

    Science.gov (United States)

    Yang, Yi-Bo; Chen, Ying; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2018-03-01

    We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of Nf = 2 + 1 DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop pertur-bative calculation and proper normalization of the glue operator, we find that the u, d, and s quark masses contribute 9(2)% to the proton mass. The quark energy and glue field energy contribute 31(5)% and 37(5)% respectively in the MS scheme at µ = 2 GeV. The trace anomaly gives the remaining 23(1)% contribution. The u, d, s and glue momentum fractions in the MS scheme are consistent with the global analysis at µ = 2 GeV.

  3. Linear mass reflectron

    International Nuclear Information System (INIS)

    Mamyrin, B.A.; Shmikk, D.V.

    1979-01-01

    A description and operating principle of a linear mass reflectron with V-form trajectory of ion motion -a new non-magnetic time-of-flight mass spectrometer with high resolution are presented. The ion-optical system of the device consists of an ion source with ionization by electron shock, of accelerating gaps, reflector gaps, a drift space and ion detector. Ions move in the linear mass refraction along the trajectories parallel to the axis of the analyzer chamber. The results of investigations into the experimental device are given. With an ion drift length of 0.6 m the device resolution is 1200 with respect to the peak width at half-height. Small-sized mass spectrometric transducers with high resolution and sensitivity may be designed on the base of the linear mass reflectron principle

  4. Top Quark Mass

    CERN Document Server

    Mulders, Martijn

    2016-01-01

    Ever since the discovery of the top quark at the Tevatron collider in 1995 the measurement of its mass has been a high priority. As one of the fundamental parameters of the Standard Theory of particle physics, the precise value of the top quark mass together with other inputs provides a test for the self-consistency of the theory, and has consequences for the stability of the Higgs field that permeates the Universe. In this review I will briefly summarize the experimental techniques used at the Tevatron and the LHC experiments throughout the years to measure the top quark mass with ever improving accuracy, and highlight the recent progress in combining all measurements in a single world average combination. As experimental measurements became more precise, the question of their theoretical interpretation has become important. The difficulty of relating the measured quantity to the fundamental top mass parameter has inspired alternative measurement methods that extract the top mass in complementary ways. I wil...

  5. Origins of mass

    Science.gov (United States)

    Wilczek, Frank

    2012-10-01

    Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. That mass-concept is tremendously useful in the approximate description of baryon-dominated matter at low energy — that is, the standard "matter" of everyday life, and of most of science and engineering — but it originates in a highly contingent and non-trivial way from more basic concepts. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). Additional quantitatively small, though physically crucial, contributions come from the intrinsic masses of elementary quanta (electrons and quarks). The equations for massless particles support extra symmetries — specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ( W and Z bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive ( i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of W and Z boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle. The mass of the Higgs particle itself is not explained in the theory, but appears as a free parameter. Earlier results suggested, and recent observations at the Large Hadron Collider (LHC) may indicate, the actual existence of the Higgs particle, with mass m H

  6. Thermal effects on the photon mass

    International Nuclear Information System (INIS)

    Woloshyn, R.M.

    1982-09-01

    It is shown that processes of O(αGsub(F)) in which the photon interacts indirectly with the thermal neutrino background dominate electric screening at low temperature. The photon electric mass still comes out to be much smaller than the present experimental limit

  7. Limit, breakthrough and prosperity

    International Nuclear Information System (INIS)

    Takahashi, Minoru

    1973-01-01

    It is pointed out that the flow toward serious crises is in progress with regard to energy and industrial problems. Technical and industrial preparation and countermeasure to the flow are proposed, and the existence of a certain new world attainable on the assumption that the countermeasure is successful is described. The relation between oil output and the increasing demand for energy is pointed out as a subject matter of the crisis. The contribution of oil energy to total energy, after the output turns to decreasing process, decreases by 177.87x10 6 tons (converted to coal at the rate 6848 kcal/kg) per year at maximum. Converted to the GNP of the world, this becomes (425 dollar/ton x 177.87 x 10 6 ton=75.6 x 10 9 dollar). This fluctuation width in a year must be compensated by the change of industrial structure and energy supplying means. The countermeasure and preparation are proposed from the viewpoints of the energy and the industrial structure in which nuclear power generation plays important role. The largest production on the earth limited by energy consumption and the temperature balance on the earth is investigated, and the perspective in the future is given. (Yamamoto, Y.)

  8. What value, detection limits

    International Nuclear Information System (INIS)

    Currie, L.A.

    1986-01-01

    Specific approaches and applications of LLD's to nuclear and ''nuclear-related'' measurements are presented in connection with work undertaken for the U.S. Nuclear Regulatory Commission and the International Atomic Energy Agency. In this work, special attention was given to assumptions and potential error sources, as well as to different types of analysis. For the former, the authors considered random and systematic error associated with the blank and the calibration and sample preparation processes, as well as issues relating to the nature of the random error distributions. Analysis types considered included continuous monitoring, ''simple counting'' involving scalar quantities, and spectrum fitting involving data vectors. The investigation of data matrices and multivariate analysis is also described. The most important conclusions derived from this study are: that there is a significant lack of communication and compatibility resulting from diverse terminology and conceptual bases - including no-basis ''ad hoc'' definitions; that the distinction between detection decisions and detection limits is frequently lost sight of; and that quite erroneous LOD estimates follow from inadequate consideration of the actual variability of the blank, and systematic error associated with the blank, the calibration-recovery factor, matrix effects, and ''black box'' data reduction models

  9. Mass of a Black Hole Firewall

    Science.gov (United States)

    Abramowicz, M. A.; Kluźniak, W.; Lasota, J.-P.

    2014-03-01

    Quantum entanglement of Hawking radiation has been supposed to give rise to a Planck density "firewall" near the event horizon of old black holes. We show that Planck density firewalls are excluded by Einstein's equations for black holes of mass exceeding the Planck mass. We find an upper limit of 1/(8πM) to the surface density of a firewall in a Schwarzschild black hole of mass M, translating for astrophysical black holes into a firewall density smaller than the Planck density by more than 30 orders of magnitude. A strict upper limit on the firewall density is given by the Planck density times the ratio MPl/(8πM).

  10. A Review of Target Mass Corrections

    Energy Technology Data Exchange (ETDEWEB)

    I. Schienbein; V. Radescu; G. Zeller; M. E. Christy; C. E. Keppel; K. S. McFarland; W. Melnitchouk; F. I. Olness; M. H. Reno; F. Steffens; J.-Y. Yu

    2007-09-06

    With recent advances in the precision of inclusive lepton-nuclear scattering experiments, it has become apparent that comparable improvements are needed in the accuracy of the theoretical analysis tools. In particular, when extracting parton distribution functions in the large-x region, it is crucial to correct the data for effects associated with the nonzero mass of the target. We present here a comprehensive review of these target mass corrections (TMC) to structure functions data, summarizing the relevant formulas for TMCs in electromagnetic and weak processes. We include a full analysis of both hadronic and partonic masses, and trace how these effects appear in the operator product expansion and the factorized parton model formalism, as well as their limitations when applied to data in the x -> 1 limit. We evaluate the numerical effects of TMCs on various structure functions, and compare fits to data with and without these corrections.

  11. Dynamical Mass Generation.

    Science.gov (United States)

    Mendel Horwitz, Roberto Ruben

    1982-03-01

    In the framework of the Glashow-Weinberg-Salem model without elementary scalar particles, we show that masses for fermions and intermediate vector bosons can be generated dynamically. The mechanism is the formation of fermion-antifermion pseudoscalar bound states of zero total four momentum, which form a condensate in the physical vacuum. The force responsible for the binding is the short distance part of the net Coulomb force due to photon and Z exchange. Fermions and bosons acquire masses through their interaction with this condensate. The neutrinos remain massless because their righthanded components have no interactions. Also the charge -1/3 quarks remain massless because the repulsive force from the Z exchange dominates over the Coulomb force. To correct this, we propose two possible modifications to the theory. One is to cut off the Z exchange at very small distances, so that all fermions except the neutrinos acquire masses, which are then, purely electromagnetic in origin. The other is to introduce an additional gauge boson that couples to all quarks with a pure vector coupling. To make this vector boson unobservable at usual energies, at least two new fermions must couple to it. The vector boson squared masses receive additive contributions from all the fermion squared masses. The photon remains massless and the masses of the Z and W('(+OR -)) bosons are shown to be related through the Weinberg angle in the conventional way. Assuming only three families of fermions, we obtain estimates for the top quark mass.

  12. Probabilistic Mass Growth Uncertainties

    Science.gov (United States)

    Plumer, Eric; Elliott, Darren

    2013-01-01

    Mass has been widely used as a variable input parameter for Cost Estimating Relationships (CER) for space systems. As these space systems progress from early concept studies and drawing boards to the launch pad, their masses tend to grow substantially, hence adversely affecting a primary input to most modeling CERs. Modeling and predicting mass uncertainty, based on historical and analogous data, is therefore critical and is an integral part of modeling cost risk. This paper presents the results of a NASA on-going effort to publish mass growth datasheet for adjusting single-point Technical Baseline Estimates (TBE) of masses of space instruments as well as spacecraft, for both earth orbiting and deep space missions at various stages of a project's lifecycle. This paper will also discusses the long term strategy of NASA Headquarters in publishing similar results, using a variety of cost driving metrics, on an annual basis. This paper provides quantitative results that show decreasing mass growth uncertainties as mass estimate maturity increases. This paper's analysis is based on historical data obtained from the NASA Cost Analysis Data Requirements (CADRe) database.

  13. Top quark mass measurement

    International Nuclear Information System (INIS)

    Maki, Tuula; Helsinki Inst. of Phys.; Helsinki U. of Tech.

    2008-01-01

    The top quark is the heaviest elementary particle. Its mass is one of the fundamental parameters of the standard model of particle physics, and an important input to precision electroweak tests. This thesis describes three measurements of the top-quark mass in the dilepton decay channel. The dilepton events have two neutrinos in the final state; neutrinos are weakly interacting particles that cannot be detected with a multipurpose experiment. Therefore, the signal of dilepton events consists of a large amount of missing energy and momentum carried off by the neutrinos. The top-quark mass is reconstructed for each event by assuming an additional constraint from a top mass independent distribution. Template distributions are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. The final top-quark mass is derived using a likelihood fit to compare the reconstructed top mass distribution from data to the parameterized templates. One of the analyses uses a novel technique to add top mass information from the observed number of events by including a cross-section-constraint in the likelihood function. All measurements use data samples collected by the CDF II detector

  14. Organ mass measurements

    International Nuclear Information System (INIS)

    Kawamura, H.

    1998-01-01

    The term, anatomical measurements, in the context of this Co-ordinated Research Programme refers to measurements of masses of internal organs, although the human body is composed of internal organs and tissues such as skeleton, muscle, skin and adipose. The mass of an organ containing a radionuclide (source organ), and the mass of a target organ which absorbs energy of the radiation, are essential parameters in the ICRP dosimetric model derived from the MIRD method. Twelve specific organs of interest were proposed at the Coordinated Research Programme Project Formulation Meeting (PFM) in 1988. A slightly different set of thirteen organs with potential significance for radiation protection were selected for study at the Research Co-ordination Meeting held at the Bhabha Atomic Research Centre in 1991. The dimensions of the organs could also be useful information, but were considered unimportant for internal dose assessment. Due to the strong concern about the unified method for collecting organ mass data at the PFM, a guide-line was established stressing the need for organ data from subjects that were healthy and normal, at least until shortly before death, or from sudden death cases, following the Japanese experience. In this report, masses of nine to thirteen organs are presented from seven participating countries. Three participants have also reported the organ masses as fractions of the total body mass

  15. Ultraluminous supersoft X-ray sources

    Science.gov (United States)

    Liu, Jifeng; Bai, Yu; Wang, Song; Justham, Stephen; Lu, You-Jun; Gu, Wei-Min; Liu, Qing-Zhong; di Stefano, Rosanne; Guo, Jin-Cheng; Cabrera-Lavers, Antonio; Álvarez, Pedro; Cao, Yi; Kulkarni, Shri

    2017-06-01

    While ultraluminous supersoft X-ray sources (ULSs) bear features for intermediate mass black holes or very massive white dwarfs possibly close to Chandrasekhar mass limit, our recent discovery of processing relativistic baryonic jets from a prototype ULS in M81 demonstrate that they are not IMBHs or WDs, but black holes accreting at super-Eddington rates. This discovery strengthens the recent ideas that ULXs are stellar black holes with supercritical accretion, and provides a vivid manifestation of what happens when a black hole devours too much, that is, it will generate thick disk winds and fire out sub-relativistic baryonic jets along the funnel as predicted by recent numerical simulations.

  16. Effects of magnetic fields in white dwarfs

    International Nuclear Information System (INIS)

    Franzon, Bruno; Schramm, Stefan

    2017-01-01

    We perform calculations of white dwarfs endowed with strong magnetic fields. White dwarfs are the progenitors of supernova Type Ia explosions and they are widely used as candles to show that the Universe is expanding and accelerating. However, observations of ultraluminous supernovae have suggested that the progenitor of such an explosion should be a white dwarf with mass above the well-known Chandrasekhar limit ∼ 1.4 M⊙. In corroboration with other works, but by using a fully general relativistic framework, we obtained also strongly magnetized white dwarfs with masses M ∼ 2.0 M⊙. (paper)

  17. Masses of Formal Philosophy

    DEFF Research Database (Denmark)

    Masses of Formal Philosophy is an outgrowth of Formal Philosophy. That book gathered the responses of some of the most prominent formal philosophers to five relatively open and broad questions initiating a discussion of metaphilosophical themes and problems surrounding the use of formal methods i...... in philosophy. Including contributions from a wide range of philosophers, Masses of Formal Philosophy contains important new responses to the original five questions.......Masses of Formal Philosophy is an outgrowth of Formal Philosophy. That book gathered the responses of some of the most prominent formal philosophers to five relatively open and broad questions initiating a discussion of metaphilosophical themes and problems surrounding the use of formal methods...

  18. Minimum critical mass systems

    International Nuclear Information System (INIS)

    Dam, H. van; Leege, P.F.A. de

    1987-01-01

    An analysis is presented of thermal systems with minimum critical mass, based on the use of materials with optimum neutron moderating and reflecting properties. The optimum fissile material distributions in the systems are obtained by calculations with standard computer codes, extended with a routine for flat fuel importance search. It is shown that in the minimum critical mass configuration a considerable part of the fuel is positioned in the reflector region. For 239 Pu a minimum critical mass of 87 g is found, which is the lowest value reported hitherto. (author)

  19. The limits of deterrence

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2009-01-01

    The objective of this contribution is to propose a better insight of the validity of the theory of deterrence, and of related doctrines in more complex and more various situations than in the past: emergence of powers like China and India, of new nuclear States like North Korea and Pakistan, of countries planning to acquire nuclear weapons like Iran, and possibility of a new wave of nuclear proliferation in Middle-East and north-eastern Asia. It also aims at providing arguments in the debates on the struggle against nuclear proliferation and on the future of deterrence. The author first presents and comments the principles of deterrence, and illustrates them by more or less recent historical situations (Iran during the war with Iraq, USA after Pearl Harbour, Arab-Israeli wars, Iraq, and so on). He notably outlines that the notion of deterrence is present in Islamic culture, and that Iran has well integrated it in its defence strategy. Examples of statements and behaviours of other Arab leaders are discussed. The author also briefly indicates how the deterrence strategy is present in the official doctrines of Russia, India, Pakistan, and North Korea. In a second part, based on various examples, the author analyses the practical limitations of deterrence by distinguishing the psychological dimension (bounded rationality, political leaders suffering from various psychological problems, importance of the ideological and spiritual dimension, values prevailing on interests, the case of Iran), and the strategic dimension (good understanding of the enemy, sensitivity of the threat of massive damages, existence of a single decision centre and of an efficient communication). The author finally proposes seven recommendations for better deterrence efficiency

  20. Over the limit.

    Science.gov (United States)

    Qu, G

    1989-01-01

    With over 1 billion population, China is adding some 15 million to that total each year. And in the 18 years from 1982 to 2000, the net increase of Chinese population is expected to exceed 200 million. Because of the gigantic pressure from population and some mistakes in policies, the levels of ecological destruction and environment pollution are both serious. This includes deforestation, grassland degradation, desert encroachment, water resources shortage, and waste of mineral resources. Natural disasters including floods and droughts caused by those problems happen more and more frequently. If development damages the resource base, it can only result in a false prosperity, the so-called hollow economy. A large number of environmental problems result directly or indirectly from the pressure of population growth. Studies show that the appropriate number of people that can be supported by China's 9.6 million sq. km is about 700 million. However, this limit is now exceeded by over 300 million people, and will be exceeded by 500 million by the end of this century. Therefore, the task is to implement a birth control policy. At present, in urban areas, the goal of family planning has been reached, but in rural areas hard work is needed. Population control in urban areas, especially in big and medium-sized cities, includes dealing with the inflow of migrants from the countryside. There are 13 cities with a population above 2 million, 37 cities above 1-2 million, and 75 cities above 0.5-1 million. A lot of cities are very crowded, exerting great pressure on the environment. The booming of rural enterprises could provide a good solution to control the flow of rural people into big and medium-sized cities. The relationship between population, resources, environment, and development should be managed properly.