6,576 research outputs found
Velocity and Distribution of Primordial Neutrinos
The Cosmic Neutrinos Background (\textbf{CNB}) are Primordial Neutrinos
decoupled when the Universe was very young. Its detection is complicated,
especially if we take into account neutrino mass and a possible breaking of
Lorentz Invariance at high energy, but has a fundamental relevance to study the
Big-Bang. In this paper, we will see that a Lorentz Violation does not produce
important modification, but the mass does. We will show how the neutrinos
current velocity, with respect to comobile system to Universe expansion, is of
the order of 1065 , much less than light velocity. Besides, we
will see that the neutrinos distribution is complex due to Planetary motion.
This prediction differs totally from the usual massless case, where we would
get a correction similar to the Dipolar Moment of the \textbf{CMB}.Comment: 16 pages, latex, 7 figure
Small clique number graphs with three trivial critical ideals
The critical ideals of a graph are the determinantal ideals of the
generalized Laplacian matrix associated to a graph. In this article we provide
a set of minimal forbidden graphs for the set of graphs with at most three
trivial critical ideals. Then we use these forbidden graphs to characterize the
graphs with at most three trivial critical ideals and clique number equal to 2
and 3.Comment: 33 pages, 3 figure
The Large- Limit of the Two-Hermitian-matrix model by the hidden BRST method
This paper discusses the large N limit of the two-Hermitian-matrix model in
zero dimensions, using the hidden BRST method. A system of integral equations
previously found is solved, showing that it contained the exact solution of the
model in leading order of large .Comment: 19 pages, Latex,CERN--TH-6531/9
Development of an energy-absorbing passenger seat for a transport aircraft
Commercial air transport passenger safety and survivability, in the event of an impact-survivable crash, are subjects receiving increased technical focus/study by the aviation community. A B-720 aircraft, highly instrumented, and remotely controlled from the ground by a pilot in a simulated cockpit, was crashed on a specially prepared gravel covered impact site. The aircraft was impacted under controlled conditions in an air-to-ground gear-up mode, at a nominal speed of 150 knots and 4-1/2 deg glide slope. Data from a number of on board, crash worthiness experiments provided valuable information related to structural loads/failure modes, antimisting kerosene fuel, passenger and attendant restraint systems and energy absorbing seats. The development of an energy absorbing (EA) seat accomplished through innovative modification of a typical modern standard commercial aviation transport, three passenger seat is described
A New Supersymmetric Extension of Conformal Mechanics
In this paper a new supersymmetric extension of conformal mechanics is put
forward. The beauty of this extension is that all variables have a clear
geometrical meaning and the super-Hamiltonian turns out to be the
Lie-derivative of the Hamiltonian flow of standard conformal mechanics. In this
paper we also provide a supersymmetric extension of the other conformal
generators of the theory and find their "square-roots". The whole superalgebra
of these charges is then analyzed in details. We conclude the paper by showing
that, using superfields, a constraint can be built which provides the exact
solution of the system.Comment: 11 pages, no figure
Optimisation of the weighting functions of an H<sub>â</sub> controller using genetic algorithms and structured genetic algorithms
In this paper the optimisation of the weighting functions for an H<sub>â</sub> controller using genetic algorithms and structured genetic algorithms is considered. The choice of the weighting functions is one of the key steps in the design of an H<sub>â</sub> controller. The performance of the controller depends on these weighting functions since poorly chosen weighting functions will provide a poor controller. One approach that can solve this problem is the use of evolutionary techniques to tune the weighting parameters. The paper presents the improved performance of structured genetic algorithms over conventional genetic algorithms and how this technique can assist with the identification of appropriate weighting functions' orders
Light airplane crash tests at three roll angles
Three similar twin engine general aviation airplanes were crash tested at the Langley impact dynamics research facility at 27 m/sec and at nominal roll angles of 0 deg, -15 deg, and -30 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed
Ammonia emissions from livestock production in Chile: an inventory and uncertainty analysis
IndexaciĂłn: Web of Science; Scielo.The objective of this work was to quantify the country's NH3 emissions from livestock production. This calculation was based on the mass flow of total ammoniacal nitrogen (TAN). The analysis was performed for all 15 geographical regions in Chile. The definition of livestock subcategories was based on data from the Chilean Agriculture and Forestry Census as well as technical reports published by the Chilean National Statistics Institute. Significant differences were observed among the sources of livestock emissions in Chile's regions, and there was high variability depending on the degree of livestock confinement. In 2013, the total calculated emissions were 69.1 kt NH3/year (± 31.1). The OâHiggins Region had the highest NH3 emissions in Chile, representing 45% of the total. In terms of livestock production, 45% of the emissions were generated by pigs, 22% by poultry, 16% by cattle, 11% by equines and 4% by sheep. Emissions from the TAN that was available during manure and slurry management and the degree of animal confinement were the primary sources of uncertainty. This uncertainty could be greatly reduced by developing regional emission factors and by including the degree of animal confinement in Chile's national statistics such as the Agriculture, Livestock and Forestry Census.http://www.scielo.cl/scielo.php?pid=S0718-95162016005000005&script=sci_abstrac
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