Design and realization for radar cross section reduction of patch antennas using shorted stubs metamaterial absorbers

This thesis is devoted to analyzing of the Radar Cross Section (RCS) of rectangular patch antenna using Metamaterial Absorber (MMA) and the analysis of its reducing techniques. The addressed theme has a great complexity and it covers various areas that include designing and optimization of target geometrical model of rectangular patch antenna structures and making it compatible with respect to metamaterial geometry. Analyses have been made to optimize and validate the structure performances that include numerical methods for electromagnetic field computation, MMA behavior, characterization, extraction of parameters, antenna radiation performance analyses, simulation, fabrication, testing, and optimization with back validating the designs. The MMA structure finds its applications in antenna designing for the reduction of Monostatic and Bistatic RCS in stealth platform for lower detectable objects. However, there is still more emphasis needed to devote for in-band frequency response for low RCS of the antenna. Therefore, making these assumptions, we have been proposing novel designs of single-band, dual-band, and triple-band MMA structures. These structures provide significant scattering characteristics and offering flexibility to the designer to control and tune the resonant frequency, based on the specific applications as compared to that of the other MMAs in the microwave regime of the Electromagnetic (EM) spectrum. To explore the research scope, a three dimensional Frequency Selective Surface (FSS) structure has been analyzed and its simulation responses with respect to parametric analyses have been made. The research investigation further extended to Electronic Band Gap (EBG) Structure and Defected Ground Structure (DGS). A hybrid structure of patch antenna is proposed and designed for an inset feed rectangular microstrip patch antenna operating at 2.45 GHz in the Industrial, Scientific, and Medical (ISM) band. This hybrid structure claims the size reduction, bandwidth, and gains enhancement. The main focus of this research work is limited to determine the potential and practical feasibility of MMA’s to enhance the stealth performance of rectangular patch antennas. For this purpose, Monostatic and Bistatic RCS simulation and measurements are carried out in an anechoic chamber and practical methods for Radar Cross Section reduction are discussed and analyzed

In silico comparative analysis of conserved genes expressed in solanaceous plants under abiotic stresses

The gene expression data was studied in order to analyze genes involved in different abiotic stresses in solanaceous plants. Salt, temperature (heat & cold) and drought are the main abiotic stresses to the plants. Abiotic stress responses are important for sessile organisms like plants because they have to cope with environmental changes to survive. The idea was to analyze those differentially expressed genes, which show common expression in response to different abiotic stress conditions in each plant. Mitogen activated protein kinases (MAPK) are important mediators in signal transmission, connecting the perception of external stimuli to cellular responses. In plants, MAPKs plays a major role in the signaling of abiotic stresses. The expression data were retrieved from gene expression omnibus (GEO) database at NCBI. The set of genes were selected showing up or down regulation in at least two abiotic stresses. These genes were used for searching their involvement in different steps of MAP kinase pathway. Our findings suggest that a common set of genes are the key players in signaling pathway responsible for initiation of cascade of reaction in response to stress. The study will help to understand how the conserved genes are expressing differentially in response to various abiotic stresses. The common genes affecting the MAP kinase pathway might be highly conserved. These genes may be used to study the response of different abiotic stresses in other plant species

Implementation of an efficient Fuzzy Logic based Information Retrieval System

This paper exemplifies the implementation of an efficient Information Retrieval (IR) System to compute the similarity between a dataset and a query using Fuzzy Logic. TREC dataset has been used for the same purpose. The dataset is parsed to generate keywords index which is used for the similarity comparison with the user query. Each query is assigned a score value based on its fuzzy similarity with the index keywords. The relevant documents are retrieved based on the score value. The performance and accuracy of the proposed fuzzy similarity model is compared with Cosine similarity model using Precision-Recall curves. The results prove the dominance of Fuzzy Similarity based IR system.Comment: arXiv admin note: substantial text overlap with http://ntz-develop.blogspot.in/ , http://www.micsymposium.org/mics2012/submissions/mics2012_submission_8.pdf , http://www.slideshare.net/JeffreyStricklandPhD/predictive-modeling-and-analytics-selectchapters-41304405 by other author

Evaluation of contact spermicidal potential of Lantana camara leaf extracts on human spermatozooa

Background: The Present study was designed to evaluate the spermicidal potential of various Lantana camara leaf extracts on healthy human spermatozoa.Methods: Four different extracts viz. Petroleum ether, Chloroform, Methanol and Water were prepared and diluted to various concentrations. These were then treated with suitably diluted human semen samples. Various parameters like sperm motility, sperm viability, sperm count, hypoosmotic swelling, acrosomal status and function were noted.Results: The results showed that methanolic and aqueous extracts possessed maximum spermicidal potential in terms of above mentioned sperm health and function parameters. Therefore, methanolic and aqueous extracts were further studied for In-vitro evaluation of pro-oxidant activity by detection of ROS generation using fluorescent probe detection method.Conclusions: The results revealed that both methanolic and aqueous extracts of Lantana camara possessed pro-oxidant potential which could be attributed for its observed contact spermicidal activity

Claudin Family of Proteins and Cancer: An Overview

Tight junctions are the apical cell-cell adhesion that regulate paracellular permeability and are critical for epithelial cell polarity. Molecular architecture of tight junction has been studied extensively, which has confirmed that claudin family of proteins is integral component of tight junction. Loss of cell-cell adhesion is central to the cellular transformation and acquisition of metastatic potential; however, the role of claudin family of proteins play in a series of pathophysiological events, including human carcinoma development, is only now beginning to be understood. Several claudin mouse knockout models have been generated and the diversity of phenotypes observed clearly demonstrates their important roles in the maintenance of tissue integrity in various organs and suggest that claudins also participate in cellular contexts other than tight junctions. The mechanisms of claudin regulation and their exact roles in normal physiology and disease are being elucidated, but much work remains to be done. In this review, we have discussed the conceptual framework concerning claudins and their potential implication in cancer. We predict that next several years will likely witness a boom in our understanding of the potential role of claudins in the regulation of tumorigenesis, which may, in turn, provide new approaches for the targeted therapy

Giant mucinous cystadenoma of ovary in an adolescent girl: a case report

Ovarian masses are rarer in children and adolescent than adults. Simple ovarian cysts are most common non-neoplastic masses in children. We report this case to emphasize that mass abdomen in adolescents can be missed being asymptomatic. A 16-year-old girl presented intermittent pain abdomen, nausea and decreased appetite for 3 months. Her menstrual cycles were normal and regular. Tumor markers were within normal limits. Exploratory laparotomy with decompression of cyst followed by cystectomy was done. The histopathology revealed the mass to be a mucinous cystadenoma. Post op course was smooth. The patients’ age, size of the cyst and menopausal status of the patient are the important deciding factor in the plan of management. A conservative surgical procedure should be the primary aim in order to preserve patient’s fertility