594 research outputs found

    A methodology for estimating dog noise in an animal housing facility

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    A rectangular reverberation chamber was designed, constructed and calibrated for the experimental measurement of the sound power level (acoustic power) of a dog. Calibration of the chamber consisted of comparing the acoustic power measured for a random noise source in the chamber with that for the identical source in a free field environment. Data from dogs indicate that barking noise can be modeled as a square wave pattern with short duration and peak sound power levels in the 500 Hz octave band. A-weighted sound pressure levels of up to 114.7 dBA were absorbed, indicating a potential concern for both animals and man chronically exposed to such environments

    Gas gain and signal length measurements with a triple-GEM at different pressures of Ar-, Kr- and Xe-based gas mixtures

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    We investigate the gas gain behaviour of a triple-GEM configuration in gas mixtures of argon, krypton and xenon with ten and thirty percent of carbon dioxide at pressures between 1 and 3 bar. Since the signal widths affect the dead time behaviour of the detector we present signal length measurements to evaluate the use of the triple-GEM in time-resolved X-ray imaging.Comment: 19 pages, 21 figures, revised version, accepted for publication in Nucl. Instr. and Meth.

    Bloom-Gilman duality of the nucleon structure function and the elastic peak contribution

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    The occurrence of the Bloom-Gilman duality in the nucleon structure function is investigated by analyzing the Q**2-behavior of low-order moments, both including and excluding the contribution arising from the nucleon elastic peak. The Natchmann definition of the moments has been adopted in order to cancel out target-mass effects. It is shown that the onset of the Bloom-Gilman duality occurs around Q**2 ~ 2 (GeV/c)**2 if only the inelastic part of the nucleon structure function is considered, whereas the inclusion of the nucleon elastic peak contribution leads to remarkable violations of the Bloom-Gilman duality.Comment: in Proc. of the XVI European Conference on Few-body Problems in Physics, Autrans (France), July 199

    Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements

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    A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche charge multiplication in gas filled radiation detectors has been optimised with respect to maximum electron transparency and minimum ion feedback. We report on the charge transfer behaviour and the achievable gas gain of this device. A three-dimensional electron and ion transfer simulation is compared to results derived from electric current measurements. Similarly, we present studies of the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current measurements and simulations. Finally, we investigate the combination of the MicroCAT and the GEM by measurements with respect to the performance at different voltage settings, gas mixtures and gas pressures.Comment: 26 pages, 32 figure

    Chronic acceleration studies - Physiological responses to artificial alterations in weight Progress report

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    Influence of chronic acceleration on energy metabolism of chickens and animals, as indicated by maintenance feed requiremen

    Nonlinear corrections to the DGLAP equations in view of the HERA data

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    The effects of the first nonlinear corrections to the DGLAP evolution equations are studied by using the recent HERA data for the structure function F2(x,Q2)F_2(x,Q^2) of the free proton and the parton distributions from CTEQ5L and CTEQ6L as a baseline. By requiring a good fit to the H1 data, we determine initial parton distributions at Q02=1.4Q_0^2=1.4 GeV2^2 for the nonlinear scale evolution. We show that the nonlinear corrections improve the agreement with the F2(x,Q2)F_2(x,Q^2) data in the region of x3105x\sim 3\cdot 10^{-5} and Q21.5Q^2\sim 1.5 GeV2^2 without paying the price of obtaining a worse agreement at larger values of xx and Q2Q^2. For the gluon distribution the nonlinear effects are found to play an increasingly important role at x\lsim 10^{-3} and Q^2\lsim10 GeV2^2, but rapidly vanish at larger values of xx and Q2Q^2. Consequently, contrary to CTEQ6L, the obtained gluon distribution at Q2=1.4Q^2=1.4 GeV2^2 shows a power-like growth at small xx. Relative to the CTEQ6L gluons, an enhancement up to a factor 6\sim6 at x=105x=10^{-5}, Q02=1.4Q_0^2=1.4 GeV2^2 reduces to a negligible difference at Q^2\gsim 10 GeV2^2.Comment: 13 pages, 5 eps-figures; revision: references added, Fig. 3 revise

    A Qualitative Study of Healers and Their Clients in Germany

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    Background. The aim of this study was to investigate the nature of the relationships between healers and their clients in Germany. Methods. An interdisciplinary research team performed semistructured interviews with healers and clients and participatory observation of healing sessions. All interviews were digitally recorded, transcribed, and analyzed using content analysis. Results. Fifteen healers and sixteen clients were included. The healer-client relationship was described as a profound and unique experience, which brought forth interpersonal and spiritual connections. The healers were seen as role models for healing to occur and support for being connected spiritually. The clients had to be open-minded and responsible. The importance of the healers’ empathy was emphasized. Discussion. The relationship between healer and client can be seen as a triangular connection between client, healer, and a transcendent source which is not the case in typical patient- doctor relationships. The spiritual connection is also said to enhance the empathetic understanding of the healer. The personality and a partner-like attitude of the healer supported the client in giving a more positive meaning to his life, in reconnecting to his spirituality, and in taking responsibility. Future studies should address the role of spirituality in health care and the development of enduring healer-client relationships

    Towards a Precise Parton Luminosity Determination at the CERN LHC

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    A new approach to determine the LHC luminosity is investigated. Instead of employing the proton-proton luminosity measurement, we suggest to measure directly the parton-parton luminosity. It is shown that the electron and muon pseudorapidity distributions, originating from the decay of W+, W- and Z0 bosons produced at 14 TeV pp collisions (LHC), constrain the x distributions of sea and valence quarks and antiquarks in the range from about 3 x 10**-4 to about 10**-1 at a Q**2 of about 10**4 GeV**2. Furthermore, it is demonstrated that, once the quark and antiquark structure functions are constrained from the W+,W- and Z0 production dynamics, other quark-antiquark related scattering processes at the LHC like q-qbar --> W+W- can be predicted accurately. Thus, the lepton pseudorapidity distributions provide the key to a precise parton luminosity monitor at the LHC, with accuracies of about +-1% compared to the so far considered goal of +-5%.Comment: plain tex, 14 pages, 5 figure

    Electroweak instantons as a solution to the ultrahigh energy cosmic ray puzzle

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    We propose a scenario in which a simple power-like primary spectrum for protons with sources at cosmological distances leads to a quantitative description of all the details of the observed cosmic ray spectrum for energies from 10^{17} eV to 10^{21} eV. As usual, the ultrahigh energy protons with energies above E_{GZK} ~ 4 x 10^{19} eV loose a large fraction of their energies by the photoproduction of pions on the cosmic microwave background, which finally decay mainly into neutrinos. In our scenario, these so-called cosmogenic neutrinos interact with nucleons in the atmosphere through Standard Model electroweak instanton-induced processes and produce air showers which are hardly distinguishable from ordinary hadron-initiated air showers. In this way, they give rise to a second contribution to the observed cosmic ray spectrum -- in addition to the one from above mentioned protons -- which reaches beyond E_{GZK}. Since the whole observed spectrum is uniquely determined by a single primary injection spectrum, no fine tuning is needed to fix the ratio of the spectra below and above E_{GZK}. The statistical analysis shows an excellent goodness of this scenario. Possible tests of it range from observations at cosmic ray facilities and neutrino telescopes to searches for QCD instanton-induced processes at HERA.Comment: 14 pages, 7 figure
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