Visibility Fringe Reduction Due to Noise-Induced Effects: Microscopic Approach to Interference Experiments

Decoherence is the main process behind the quantum to classical transition. It is a purely quantum mechanical effect by which the system looses its ability to exhibit coherent behavior. The recent experimental observation of diffraction and interference patterns for large molecules raises some interesting questions. In this context, we identify possible agents of decoherence to take into account when modeling these experiments and study theirs visible (or not) effects on the interference pattern. Thereby, we present an analysis of matter wave interferometry in the presence of a dynamic quantum environment and study how much the visibility fringe is reduced and in which timescale the decoherence effects destroy the interference of massive objects. Finally, we apply our results to the experimental data reported on fullerenes and cold neutrons.Comment: 14 pages, 5 figures. Version to appear in Mod. Phys.

Synthesis and characterization of silver nanoarticles from extract of Eucalyptus citriodora

The primary motivation for the study to develop simple eco-friendly green synthesis of silver nanoparticles using leaf extract of Eucalyptus citriodora as reducing and capping agent. The green synthesis process was quite fast and silver nanoparticles were formed within 0.5 h. The synthesis of the particles was observed by UV-visible spectroscopy by noting increase in absorbance. Characterization of the particles was carried out by X-ray diffraction, FTIR and electron microscopy. The developed nanoparticles demonstrated that E. citriodora is good source of reducing agents. UV-visible absorption spectra of the reaction medium containing silver nanoparticles showed maximum absorbance at 460 nm. FTIR analysis confirmed reduction of Ag+ to Ag0 atom in silver nanoparticles. The XRD pattern revealed the crystalline structure of silver nanoparticles. The SEM analysis showed the size and shape of the nanoparticles. The method being green, fast, easy and cost effective can be recommended for large scale production of AgNPs for their use in food, medicine and materials

Biocompatible/ Bioresorbable Polymer Based Silver Nanaomaterial Coatng for Chronic Indwelling Medical Devices and Bioscaffolds for Tissue Regrowth

The objective of this study is to synthesize and characterize antimicrobial, bio-polymer based silver nanomaterials composite coatings, for use in chronic indwelling medical devices, and bioscaffolds. The coatings and bioscaffolds are comprised of novel biomass mediated silver nano particles (SNP) that are biocompatible, highly concentrated, highly pure, cost-effective, polydispersed and compatible with a range of polymer systems applicable for use with existing chronic indwelling medical devices. This thesis is divided into three main chapters. In Chapter 1, detailed review on the need for antimicrobial nanocomposite coatings for chronic indwelling medical devices along with different SNP synthesis and characterization methods is provided. In Chapter 2 a comprehensive description of biocompatible/bioresorbable poly (L-lactide) (PLLA) based thin film coatings comprised of novel 25-75 nm silver nano particles SNP is provided. The particle and film morphology is characterized using Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM) and UV-Visible Spectroscopy. The release rate of SNP is profiled by Thermogravimetric Analysis (TGA) and Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). These coatings, suitable for chronic indwelling devices, drastically reduce the microbial biofilm formed by Staphylococcus aureus and Escherichia coli by 3-5 log reduction. This chapter details the synthesis of PLLA cast-coatings and the procedure to embed SNP, an antimicrobial agent, at a range of concentrations to identify an optimal SNP concentration of 700-800 ppm that efficacious and non-cytotoxic to human epithelial carcinoma cells (HeLa). Chapter 3 explains the procedure of making biocompatible/bioresorbable PLLA-PEG co-polymer block bioscaffolds designed to degrade and resorb at a controlled rate while providing a suitable substrate for tissue regrowth. The antimicrobial properties of these porous bioscaffolds are tested across varying concentrations of biomass mediated SNP, to determine an efficacious antimicrobial concentration. The bioscaffolds are efficacious as it reduces the Staphylococcus aureus and Escherichia coli biofilm by 92.5- 99.9%, respectively, at an antimicrobial SNP concentration of 800ppm

Decentralization, local government elections and voter turnout in Pakistan:

"Decentralization has the potential to improve the accountability of government and lead to a more efficient provision of public services. However, accountability requires broad groups of people to participate in local government. Thus, voter turnout at local government elections is an important component of government accountability. This study used survey data on the 2005 local government elections in Pakistan to analyze the impact of electoral mechanisms, the credibility of elections, and voters' socioeconomic characteristics on voter turnout. The rational-choice perspective is applied to develop the specifications of the empirical model. The empirical analysis is based on a series of standard and multilevel random-intercept logistic models. Our important findings reveal that (1) voter turnout is strongly associated with the personal and social gratifications people derive from voting; (2) the preference-matching ability of candidates for local government positions is marginal; and (3) the introduction of direct elections of the district nazims—a key position in local government—might improve electoral participation and thus create a precondition for better local government accountability. The findings also suggest that less educated people, farmers, and rural people are more likely to vote." Authors' AbstractDecentralization, local government elections, political participation, voter turnout, Public service provision, Governance,

MODLEACH: A Variant of LEACH for WSNs

Wireless sensor networks are appearing as an emerging need for mankind. Though, Such networks are still in research phase however, they have high potential to be applied in almost every field of life. Lots of research is done and a lot more is awaiting to be standardized. In this work, cluster based routing in wireless sensor networks is studied precisely. Further, we modify one of the most prominent wireless sensor network's routing protocol "LEACH" as modified LEACH (MODLEACH) by introducing \emph{efficient cluster head replacement scheme} and \emph{dual transmitting power levels}. Our modified LEACH, in comparison with LEACH out performs it using metrics of cluster head formation, through put and network life. Afterwards, hard and soft thresholds are implemented on modified LEACH (MODLEACH) that boast the performance even more. Finally a brief performance analysis of LEACH, Modified LEACH (MODLEACH), MODLEACH with hard threshold (MODLEACHHT) and MODLEACH with soft threshold (MODLEACHST) is undertaken considering metrics of throughput, network life and cluster head replacements.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

Dynamics of Tunneling Centers in Metallic Systems

Dynamics of tunneling centers (TC) in metallic systems is studied, using the technique of bosonization. The interaction of the TC with the conduction electrons of the metal involves two processes, namely, the screening of the TC by electrons, and the so-called electron assisted tunneling. The presence of the latter process leads to a different form of the renormalized tunneling frequency of the TC, and the tunneling motion is damped with a temperature dependent relaxation rate. As the temperature is lowered, the relaxation rate per temperature shows a steep rise as opposed to that in the absence of electron assisted process. It is expected that this behavior should be observed at very low temperatures in a careful experiment. The present work thus tries to go beyond the existing work on the {\it dynamics} of a two-level system in metals, by treating the electron assisted process.Comment: REVTeX twocolumn format, 5 pages, two PostScript figures available on request. Preprint # : imsc 94/3

Women\u27s empowerment and health: The role of institutions of power in Pakistan

Women\u27s right to health has been reiterated many times. However, there are social and cultural barriers in developing countries that hinder their empowerment. Women\u27s low status, deprivation of education and lack of control over their own lives and bodies have a negative impact on their health status and that of their families. This paper discusses women\u27s empowerment and health within the framework of the 4 institutions of power in a society-family, community, health care systems and the state--with special reference to the situation in Pakistan. It concludes that to improve women\u27s health status, concerted efforts are needed by all these institutions of power to work towards gender equality and the greater empowerment of women