2,876 research outputs found

    Development and Characterization of Eudragit RS 100 Loaded Microsponges and its Colonic Delivery Using Natural Polysaccharides

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    In the present work, paracetamol loaded eudragit based microsponges were prepared using quasi-emulsion solvent diffusion method. The compatibility of the drug with various formulation components was established. Process parameters were analyzed in order to optimize the formulation. Shape and surface morphology of the microsponges were examined using scanning electron microscopy. The colon specific formulations were prepared by compression coating of microsponges with pectin:hydroxypropylmethylcellulose (HPMC) mixture followed by tabletting. The in vitro dissolution studies were done on all formulations and the results were evaluated kinetically and statically. The kinetics of release study showed that the release data followed Higuchi matrix and the main mechanism of drug release from microsponges was diffusion. In vitro studies exhibited that compression coated colon specific tablet formulations started the release the drug at the 6th hour corresponding to the arrival time to proximal colon

    Stochastic Coalitional Better-response Dynamics and Strong Nash Equilibrium

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    We consider coalition formation among players in an n-player finite strategic game over infinite horizon. At each time a randomly formed coalition makes a joint deviation from a current action profile such that at new action profile all players from the coalition are strictly benefited. Such deviations define a coalitional better-response (CBR) dynamics that is in general stochastic. The CBR dynamics either converges to a strong Nash equilibrium or stucks in a closed cycle. We also assume that at each time a selected coalition makes mistake in deviation with small probability that add mutations (perturbations) into CBR dynamics. We prove that all strong Nash equilibria and closed cycles are stochastically stable, i.e., they are selected by perturbed CBR dynamics as mutations vanish. Similar statement holds for strict strong Nash equilibrium. We apply CBR dynamics to the network formation games and we prove that all strongly stable networks and closed cycles are stochastically stable

    Two dimensional sediment transport model using parallel computers

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    Management and development of water bodies is vital for meeting domestic, agricultural, energy and industrial needs. To that end, dams, artificial channels, lakes and other water structures have been constructed. Management and development of these structures encounter problems of land erosion, reservoir silting, and degradation and aggradation of channel beds, which need to be addressed. Fundamental to these problems are sediment transport, erosion and deposition. Numerical modeling of sediment transport is the best tool to simulate sediment transport in a water body. This study develops a vertically integrated two-dimensional numerical sediment transport model. Sediment transport is simulated in two parts in this model: suspended load and bed load. A fractional step approach is used to solve the two-dimensional advection diffusion equation, which splits the advection-diffusion equation in to two separate parts: advection and diffusion. High resolution conservative algorithm is used to solve the advection part and a semi implicit finite difference scheme is used to solve the diffusion part. Different parallel numerical solvers are developed to solve linear system of equations resulting from diffusion part. Non-uniformity in sediment mixture which is quite common in real world problems is considered. The model is tested for different analytical and laboratory test cases. The model is coded for parallel computers so that enormous power of parallel computers can be exploited

    Managing Disaster In select Institutional Libraries in Delhi

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    Abstracts: The present paper seeks to contribute some insights into the different potential disasters that libraries are vulnerable to. The study is primarily built upon a comprehensive review of the literature. Further, the study is divided into two parts; first part, covers different disasters, policies, insurance, and role of the government in managing such disasters. The second part of the study throw light on the level of preparedness for mitigating different disasters, frequency of inspection of the equipment’s, safety guidelines and so on, to lessen the impact of disasters, basic strategies to protect any disaster in the library, frequency of power-backups, technicalities to avoid digital disasters and availability of insurance policy in the libraries. finally, the manuscript also consists of a disaster preparedness model which will be helpful in understanding the librarian to do/have list for their respective libraries

    Solid State Protective Device Topological Trade-offs for Mvdc Systems

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    Presently accepted approaches to protection are “Unit-Based” which means the power converter(s) feeding the bus coordinate with no-load electromechanical switches to isolate faulted portions of the bus. However, “Breaker-Based” approaches, which rely upon solid state circuit breakers for fault mitigation can result in higher reliability of power and potentially higher survivability. The inherent speed of operation of solid state protective devices will also play a role in fault isolation, hence reducing stress level on all system components. A comparison study is performed of protective device topologies that are suitable for shipboard distribution systems rated between 4kVdc and 20kVdc from the perspectives of size and number of passive components required to manage the commutation energy during sudden fault events and packaging scalability to higher current and voltage systems. The implementation assumes a multi-chip Silicon Carbide 10kV, 240A MOSFET/JBS diode module. A static fault simulator device is proposed to characterize DC faults
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