297 research outputs found
Implementation of a Gauss convoluted Pandel PDF for track reconstruction in Neutrino Telescopes
A probability distribution function is presented which provides a realistic
description of the detection of scattered photons. The resulting probabilities
can be described analytically by means of a superposition of several special
functions. These exact expressions can be evaluated numerically only for small
distances and limited time residuals, due to computer accuracy limitations. In
this report we provide approximations for the exact expressions in different
regions of the distance-time residual space, defined by the detector geometry
and the space-time scale of an event. These approximations can be evaluated
numerically with a relative error with respect to the exact expression at the
boundaries of less than 0.001.Comment: 9 pages, 4 figures Revision 1 : extended content 12 pages, 4 figures
Accepted for publication in Astroparticle Physic
Giant inguino scrotal hernia: a case report
A journal article on scrotal hernia diseases in developing countries.Giant inguino — scrotal hernia is largely a problem of developing countries. A case of an unusually giant inguino-scrotal hernia is reported highlighting the problems encountered in management. Orchidectomy, bowel resection and relaxing epigastric incision were successfully employed in repairing the hernia. Hernias may not be difficult to manage if they ar not neglected. Efforts of health education need intensifying in this direction. We propose thorough peri-operative pulmonary exercises to cut down the post-operative pulmonary morbidity
A WEIGHT CHECKER BASED ON DIGITAL TECHNIQUE
Recent advances in digital computer and digital communications systems have led to a corresponding growing interest in digital weight techniques because of engineering advances offered by digital systems over its analogue counterpart. In this work, a digital weight checker liquid crystal display has been designed. The weight checker uses linear voltage differential transformer (LVDT) transducer in which position of displacement of spiral is proportional to the output voltage of transducer. Its accuracy and provision of constant impedance with infinite resolution makes it suitable for most applications. The system has its range from 0 to 20v corresponding to 0 to 20kg
EFFECTS OF ORGANIC FERTILISERS ON GROWTH, YIELD AND NUTRITIONAL CONTENT OF SNOW PEAS (Pisum sativum var. saccharatum)
Snow peas (Pisum sativum var. saccharatum) are one of the widely used baby vegetable in Swaziland; however, there is a dearth of information pertaining to its organic production. A field study laid out in Factorial Randomised Complete Block Design was conducted at the Horticulture Farm, Luyengo Campus, of the University of Swaziland. Organic fertilisers used were kraal manure, broiler manure, and Igrow, applied at 20, 40, and 60 (t/ha). Inorganic fertilisers 2:3:2 (22) + 0.5% zinc and limestone ammonium nitrate (28%) were applied at 100 kg/ha and 80 kg/ha respectively. A trend of superiority of the different levels of organic manure application was observed as snow peas provided with 40 t/ha and 60 t/ha exhibited higher values in vegetative and reproductive growth, marketable yield and protein content especially on broiler and kraal manure application. The use of broiler manure at 40 t/ha and 60 t/ha in the production of vegetables like snow peas should be encouraged, because their application resulted in increased growth and yield compared to synthetic fertilisers
Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna
The random superposition of many weak sources will produce a stochastic
background of gravitational waves that may dominate the response of the LISA
(Laser Interferometer Space Antenna) gravitational wave observatory. Unless
something can be done to distinguish between a stochastic background and
detector noise, the two will combine to form an effective noise floor for the
detector. Two methods have been proposed to solve this problem. The first is to
cross-correlate the output of two independent interferometers. The second is an
ingenious scheme for monitoring the instrument noise by operating LISA as a
Sagnac interferometer. Here we derive the optimal orbital alignment for
cross-correlating a pair of LISA detectors, and provide the first analytic
derivation of the Sagnac sensitivity curve.Comment: 9 pages, 11 figures. Significant changes to the noise estimate
Calibration and Characterization of the IceCube Photomultiplier Tube
Over 5,000 PMTs are being deployed at the South Pole to compose the IceCube
neutrino observatory. Many are placed deep in the ice to detect Cherenkov light
emitted by the products of high-energy neutrino interactions, and others are
frozen into tanks on the surface to detect particles from atmospheric cosmic
ray showers. IceCube is using the 10-inch diameter R7081-02 made by Hamamatsu
Photonics. This paper describes the laboratory characterization and calibration
of these PMTs before deployment. PMTs were illuminated with pulses ranging from
single photons to saturation level. Parameterizations are given for the single
photoelectron charge spectrum and the saturation behavior. Time resolution,
late pulses and afterpulses are characterized. Because the PMTs are relatively
large, the cathode sensitivity uniformity was measured. The absolute photon
detection efficiency was calibrated using Rayleigh-scattered photons from a
nitrogen laser. Measured characteristics are discussed in the context of their
relevance to IceCube event reconstruction and simulation efforts.Comment: 40 pages, 12 figure
Search for Relativistic Magnetic Monopoles with IceCube
We present the first results in the search for relativistic magnetic
monopoles with the IceCube detector, a subsurface neutrino telescope located in
the South Polar ice cap containing a volume of 1 km. This analysis
searches data taken on the partially completed detector during 2007 when
roughly 0.2 km of ice was instrumented. The lack of candidate events
leads to an upper limit on the flux of relativistic magnetic monopoles of
\Phi_{\mathrm{90%C.L.}}\sim 3\e{-18}\fluxunits for . This is a
factor of 4 improvement over the previous best experimental flux limits up to a
Lorentz boost below . This result is then interpreted for a
wide range of mass and kinetic energy values.Comment: 11 pages, 11 figures. v2 is minor text edits, no changes to resul
Search for non-relativistic Magnetic Monopoles with IceCube
The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting
of Antarctic ice. The detector can be used to search for
signatures of particle physics beyond the Standard Model. Here, we describe the
search for non-relativistic, magnetic monopoles as remnants of the GUT (Grand
Unified Theory) era shortly after the Big Bang. These monopoles may catalyze
the decay of nucleons via the Rubakov-Callan effect with a cross section
suggested to be in the range of to
. In IceCube, the Cherenkov light from nucleon decays
along the monopole trajectory would produce a characteristic hit pattern. This
paper presents the results of an analysis of first data taken from May 2011
until May 2012 with a dedicated slow-particle trigger for DeepCore, a
subdetector of IceCube. A second analysis provides better sensitivity for the
brightest non-relativistic monopoles using data taken from May 2009 until May
2010. In both analyses no monopole signal was observed. For catalysis cross
sections of the flux of non-relativistic
GUT monopoles is constrained up to a level of at a 90% confidence level,
which is three orders of magnitude below the Parker bound. The limits assume a
dominant decay of the proton into a positron and a neutral pion. These results
improve the current best experimental limits by one to two orders of magnitude,
for a wide range of assumed speeds and catalysis cross sections.Comment: 20 pages, 20 figure
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