1,035 research outputs found

    Transition matrix approach for Monte Carlo simulation of coupled electron/phonon/photon dynamics

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    A new approach for simulating the dynamics of electrons, phonons, and photons is described. The technique provides a Monte Carlo simulation of particle dynamics without the statistical noise associated with direct Monte Carlo simulation, treats physical phenomena with a wide range of time scales, and has a good computational efficiency. A transition matrix is first precomputed by direct Monte Carlo simulation. Particle populations are then updated at regular time steps by simple matrix multiplication while correcting for nonlinear effects such as carrier–carrier scattering, band filling, hot phonons, etc. The technique is well suited to studies of quantum well laser devices and pump-probe experiments where direct Monte Carlo simulation is exceedingly difficult

    AN OVERALL VIEW ON GEMSTONE MINING IN GILGIT-BALTISTAN: PROBLEMS AND MITIGATIONS

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    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.  &nbsp

    Dosis de azufre y tiempos de aplicación en el rendimiento y la calidad del aceite de canola cultivada en suelo calcáreo

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    Pakistan has been constantly deficient in its oil seed production and it is very difficult to meet the edible oil requirement of its ever-increasing population. A field experiment was conducted at the Agronomy Research Farm, The University of Agriculture Peshawar, Northern Pakistan during winter (2013–14). Five sulphur levels (15, 30, 45, 60 and 75 kg·ha-1) and times of application (at seedling, bolting and flowering stages) were used for the canola variety Abasin-95. The experiment was laid out in a randomized complete block design replicated four times on a 5 m × 3.2 m plot size. The results showed that the sulphur-applied plots gave the highest seed yield, biological yield, glucosinolate, erucic acid, oil content, protein content, oleic acid and linoleic acid compared to the control plots. Sulphur applied at the rate of 60 kg·ha-1 and applied at the bolting stage increased seed yield, biological yield, oil content, and protein content.Pakistán ha sido constante y crónicamente deficiente en producción de semillas oleaginosas y es muy difícil cumplir con la demanda de aceites comestibles para una población cada vez mayor. Se realizó un experimento de campo en la granja de investigación agronómica de la Universidad de Agricultura Peshawar, en el norte de Pakistán, durante el invierno (2013–14). Los cinco niveles de azufre (15, 30, 45, 60 y 75 kg·ha-1) y su tiempo de aplicación (en las etapas de plántula, floración y floración) se utilizaron para la variedad de canola (Abasin-95). El experimento se realizó en un diseño de bloques completos al azar que se replicó cuatro veces con un tamaño de parcela de 5 m × 3,2 m. Los resultados mostraron que las parcelas aplicadas con azufre dieron el mayor rendimiento de semilla, rendimiento biológico, glucosinolato, ácido erúcico, contenido de aceite, contenido de proteína, ácido oleico y ácido linoleico en comparación con las parcelas de control. El azufre se aplicó en una tasa de 60 kg·ha-1 y se aplicó en la etapa de empernado, incrementando el rendimiento de las semillas, el rendimiento biológico, el contenido de aceite y el contenido de proteínas

    A Spectral Flux Method for Solving the Boltzmann Equation

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    A spectral method for solving the Boltzmann equation by the scattering matrix approach is presented, The algorithm discussed can be used to simulate both bulk and device properties with arbitrary field profiles. Although the primary goal is to reduce the data storage problem of the scattering matrix approach, many of the concepts and mathematical properties developed may be useful for other traditional spectral methods as well
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