594 research outputs found
A methodology for estimating dog noise in an animal housing facility
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
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
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
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
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
The effects of the first nonlinear corrections to the DGLAP evolution
equations are studied by using the recent HERA data for the structure function
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 GeV for the nonlinear scale
evolution. We show that the nonlinear corrections improve the agreement with
the data in the region of and
GeV without paying the price of obtaining a worse agreement at larger
values of and . For the gluon distribution the nonlinear effects are
found to play an increasingly important role at x\lsim 10^{-3} and
Q^2\lsim10 GeV, but rapidly vanish at larger values of and .
Consequently, contrary to CTEQ6L, the obtained gluon distribution at
GeV shows a power-like growth at small . Relative to the CTEQ6L gluons,
an enhancement up to a factor at , GeV
reduces to a negligible difference at Q^2\gsim 10 GeV.Comment: 13 pages, 5 eps-figures; revision: references added, Fig. 3 revise
A Qualitative Study of Healers and Their Clients in Germany
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
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
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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