12,105 research outputs found
AN OVERALL VIEW ON GEMSTONE MINING IN GILGIT-BALTISTAN: PROBLEMS AND MITIGATIONS
Gilgit-Baltistan has tremendous amount of gemstone wealth and thousands of miners are busy to explore this wealth, but due to unscientific and crude mining methods this mineral wealth goes into waste in many ways, like fractures, damages and total destructions of gemstone due to ill blasting methods and lack of proper training. Gemstone mining is done in all districts of Gilgit-Baltistan. According to a careful survey in July 2007, 32 types of Gemstones (Precious and Semiprecious) are found in GB, out of total production of gemstones produced in Pakistan 95% come from GB. According to this survey there are more than 2000 mines which produce different variety of gemstones and numbers of miners involved in this mining industry directly or indirectly are more than 25000. Due to these crude and unscientific mining methods, improper camps without hygienic facilities, lack of proper mining equipment, lack of basic health facilities and safety tools and lack of mining equipment repairing facilities at mining sites, number of problems are arising. These problems include damage to the fauna and flora in mining areas, damage to the eco system due to blasting and flow of people; mountains are becoming vulnerable due to improper mines development, glaciers melting due to use of thermal generators, spreading of human filth and waste like plastic and at last polluting of the water. This research is based on the mitigation of all these problems to some extent. The damage to the fauna and flora may be reduced by controlling spreading of human filth and waste, controlled blasting may be done by using modern blasting techniques, proper mines of international standard may be developed by enforcing the mining rules, use of thermal generators may be prohibited by developing small hydro projects at sites and at last pollution of water may be controlled by training people to adopt the cleanliness drives time to time and equipment repairing facilities at sites as well.  
New Physics and the Landau Pole
In scalar field theories the Landau pole is an ultraviolet singularity in the
running coupling constant that indicates a mass scale at which the theory
breaks down and new physics must intervene. However, new physics at the pole
will in general affect the running of the low energy coupling constant, which
will in turn affect the location of the pole and the related upper limit
(``triviality'' bound) on the low energy coupling constant. If the new physics
is strongly coupled to the scalar fields these effects can be significant even
though they are power suppressed. We explore the possible range of such effects
by deriving the one loop renormalization group equations for an effective
scalar field theory with a dimension 6 operator representing the low energy
effects of the new physics. As an independent check we also consider a
renormalizable model of the high-scale physics constructed so that its low
energy limit coincides with the effective theory.Comment: 26 pages, 5 figure
Threshold-coloring and unit-cube contact representation of planar graphs
In this paper we study threshold-coloring of graphs, where the vertex colors represented by integers are used to describe any spanning subgraph of the given graph as follows. A pair of vertices with a small difference in their colors implies that the edge between them is present, while a pair of vertices with a big color difference implies that the edge is absent. Not all planar graphs are threshold-colorable, but several subclasses, such as trees, some planar grids, and planar graphs with no short cycles can always be threshold-colored. Using these results we obtain unit-cube contact representation of several subclasses of planar graphs. Variants of the threshold-coloring problem are related to well-known graph coloring and other graph-theoretic problems. Using these relations we show the NP-completeness for two of these variants, and describe a polynomial-time algorithm for another. © 2015 Elsevier B.V
Reconstructing generalized ghost condensate model with dynamical dark energy parametrizations and observational datasets
Observations of high-redshift supernovae indicate that the universe is
accelerating at the present stage, and we refer to the cause for this cosmic
acceleration as ``dark energy''. In particular, the analysis of current data of
type Ia supernovae (SNIa), cosmic large-scale structure (LSS), and the cosmic
microwave background (CMB) anisotropy implies that, with some possibility, the
equation-of-state parameter of dark energy may cross the cosmological-constant
boundary () during the recent evolution stage. The model of ``quintom''
has been proposed to describe this crossing behavior for dark energy. As
a single-real-scalar-field model of dark energy, the generalized ghost
condensate model provides us with a successful mechanism for realizing the
quintom-like behavior. In this paper, we reconstruct the generalized ghost
condensate model in the light of three forms of parametrization for dynamical
dark energy, with the best-fit results of up-to-date observational data.Comment: 8 pages, 3 figures; references added; accepted for publication in
Mod. Phys. Lett.
On the Prospects for Laser Cooling of TlF
We measure the upper state lifetime and two ratios of vibrational branching
fractions f_{v'v} on the B^{3}\Pi_{1}(v') - X^{1}\Sigma^{+}(v) transition of
TlF. We find the B state lifetime to be 99(9) ns. We also determine that the
off-diagonal vibrational decays are highly suppressed: f_{01}/f_{00} <
2x10^{-4} and f_{02}/f_{00} = 1.10(6)%, in excellent agreement with their
predicted values of f_{01}/f_{00} < 8x10^{-4} and f_{02}/f_{00} = 1.0(2)% based
on Franck-Condon factors calculated using Morse and RKR potentials. The
implications of these results for the possible laser cooling of TlF and
fundamental symmetries experiments are discussed.Comment: 5 pages, 2 figure
Two body decays of the -quark: Applications to direct CP violation, searches for electro-weak penguins and new physics
A systematic experimental search for two-body hadronic decays of the b-quark
of the type b to quark + meson is proposed. These reactions have a well defined
experimental signature and they should be theoretically cleaner compared to
exclusive decays. Many modes have appreciable branching ratios and partial rate
asymmetries may also be quite large (about 8-50%) in several of them. In a few
cases electroweak penguins appear to be dominant and may be measurable. CP
violating triple correlation asymmetries provide a clean test of the Standard
Model.Comment: 12 pages 1 figure 1 tabl
Uniform shear flow in dissipative gases. Computer simulations of inelastic hard spheres and (frictional) elastic hard spheres
In the preceding paper (cond-mat/0405252), we have conjectured that the main
transport properties of a dilute gas of inelastic hard spheres (IHS) can be
satisfactorily captured by an equivalent gas of elastic hard spheres (EHS),
provided that the latter are under the action of an effective drag force and
their collision rate is reduced by a factor (where is
the constant coefficient of normal restitution). In this paper we test the
above expectation in a paradigmatic nonequilibrium state, namely the simple or
uniform shear flow, by performing Monte Carlo computer simulations of the
Boltzmann equation for both classes of dissipative gases with a dissipation
range and two values of the imposed shear rate .
The distortion of the steady-state velocity distribution from the local
equilibrium state is measured by the shear stress, the normal stress
differences, the cooling rate, the fourth and sixth cumulants, and the shape of
the distribution itself. In particular, the simulation results seem to be
consistent with an exponential overpopulation of the high-velocity tail. The
EHS results are in general hardly distinguishable from the IHS ones if
, so that the distinct signature of the IHS gas (higher
anisotropy and overpopulation) only manifests itself at relatively high
dissipationsComment: 23 pages; 18 figures; Figs. 2 and 9 include new simulations; two new
figures added; few minor changes; accepted for publication in PR
Reconstructing f(R) model from Holographic DE: Using the observational evidence
We investigate the corresponding relation between gravity and an
interacting holographic dark energy. By obtaining conditions needed for some
observational evidence such as, positive acceleration expansion of universe,
crossing the phantom divide line and validity of thermodynamics second law in
an interacting HDE model and corresponding it with mode of gravity we
find a viable model which can explain the present universe. We also
obtain the explicit evolutionary forms of the corresponding scalar field,
potential and scale factor of universe.Comment: 11page. phys. Scr (2012
Uniqueness Theorem for Static Black Hole Solutions of sigma-models in Higher Dimensions
We prove the uniqueness theorem for self-gravitating non-linear sigma-models
in higher dimensional spacetime. Applying the positive mass theorem we show
that Schwarzschild-Tagherlini spacetime is the only maximally extended, static
asymptotically flat solution with non-rotating regular event horizon with a
constant mapping.Comment: 5 peges, Revtex, to be published in Class.Quantum Gra
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