Archives-October 2014

The aim of the present study is to formulate and evaluate Captopril micro-encapsules. Microspheres and micropellets of captopril prepared with different polymers through the techniques of microencapsulation were found to have a good spherical shape, and were non-aggregated exhibiting good flow properties. In addition, all the formulations prepared, showed a good drug incorporation efficiency and an extended release of the drug, thereby enhancing the duration of action. The different techniques used in the preparation such as, emulsion-phase separation, solvent-evaporation and ionotropic- gelation techniques were found to be simple and reproducible. All the polymers used viz, chitosan, ethyl cellulose, sodium alginate and HPMC were economic, easily available and biocompatible. And hence, the industrial applicability of the methods would be simple and rapid, provided the work being extended to in-vivo studies. It is obvious from the above work that, the study has engineered a drug delivery profile in which the drug release is controlled to a great extend and that the formulations in therapy can minimize untoward side effects, thus improving patient compliance.

This study investigates the mechanical properties of Chrysophyllum albidum to determine its potential for utilization in Nigeria. The test samples were obtained from tree at breast height. Results of test on Chrysophyllum albidum showed that the mean impact bending was 1.08m which increased from the corewood to the outerwood and remained constant upward along the tree. The mean MOR was 155.18N/mm2, which ranged from 151.46 to 157.53N/mm2 radially. Also the axial values ranged from 158.77 to 152.58N/mm2. There was an increase in MOR from the corewood to the outerwood and there is a decrease in MOR from the top of the tree (25%) to the base (75%). The mean MOE was 39309.04N/mm2, and ranged from 36303.84 to 40409.65N/mm2 radially and from 40993.7 to 39547.57N/mm2 axially. There was an increase in MOE from corewood to the outerwood. Conversely, there was a decrease from the base to the top of the tree.The mean maximum compression strength parallel to the grain was 45.55N/mm2, the highest value was obtained at the middlewood and decrease from the base (25%, 46.91N/mm2) to the top (75%, 43.95N/mm2) of the wood. In conclusion, a comparison of the strength properties values obtained with economic tree species such as Milicia excelsa, Mansonia altissima, Khaya species e.t.c shows that Chrysophyllum albidum wood has almost the same values with these economic species.

This paper proposed the Proportional Integral Derivative (PID) type multiple stabilizers to damp inter-area and intra-area low frequency oscillations in power system utility. To improve power system stability, optimal tuning of the PID type stabilizer gains and non-smooth nonlinear parameters is importance and a challenging task to accommodate variations in the power system dynamics, mainly when multiple PSSs are applied. Because, it is a computationally expensive combinational and nonlinear optimization problem. In this paper, Elitist Gravitational Search Algorithm (EGSA) is proposed to optimize multiple PID type PSSs gains tuning problem, simultaneously in order to reduce stabilizer design effort and find the best possible solution. The EGSA is a novel meta-heuristic stochastic optimization algorithm and simulates the masses cooperate using a direct form of communication through gravitational force to find the best possible solution within a reasonable computation time. It provides both global and local search by changing the velocities over time to determine distance and direction of agents (masses) for significant increasing the probability of finding the optimal solution and efficiently avoiding local optimum to a large extent. To optimize of multiple PSSs gains a nonlinear time domain-based objective function under various operating conditions is considered. It is solved using EGSA technique that has strong and robust search capability than the other heuristic optimization algorithm, as well as is being easy to implement. The effectiveness of the proposed EGSA based stabilizers is investigated on a two-area four machine power system through the nonlinear time domain simulation and some performance indices under different operation condition and system configurations. The performance of the proposed stabilizer is compared with those of standard Particle Swarm Optimization (PSO) and PSO with time variant acceleration coefficients based designed PSSs to illustrate its robustness and damping quality. The results analysis reveals that the EGSA based tuned PID type PSS is effective and achieves good low frequency oscillations damping capability. Moreover, it is superior that of the PSO method in terms of accuracy, convergence and computational effort.

Wavelet transforms enable us to represent signals with a high degree of scarcity. Wavelet thresholding is a signal estimation technique that exploits the capabilities of wavelet transform for signal denoising. The aim of this paper is to study various thresholding techniques such as Sure Shrink, Visu Shrink and Bayes Shrink and determine the best one for image denoising. This paper presents an overview of various threshold methods for image denoising. Wavelet transform based denoising techniques are of greater interest because of their performance over Fourier and other spatial domain techniques. Selection of optimal threshold is crucial since threshold value governs the performance of denoising algorithms. Hence it is required to tune the threshold parameter for better PSNR values. In this paper, we present various wavelet based shrinkage methods for optimal threshold selection for noise removal.

The leaves of Tectona grandis (Verbanaceae) was subjected to hydrodistillation in order to obtain the essential oil from the plant. The pale yellow essential oil gave a percentage yield of 0.184%. Relative percentages of individual component were analyzed by GC/GC-MS. A total of fifty-four (54) constituents were identified representing 86.5% of the total essential oil fraction. Oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, apocarotenoids, phenylpropanoids and non-terpene derivatives were the various classes of compounds identified. The LC50 value from the brine shrimp toxicity assay was 183.29µg/ml. The oil extract was also subjected to antibacterial assay and it showed significant activities against all the clinical test organisms used except Pseudomonas aeruginosa.

Crack growth characteristics of rubbery materials are an important factor in determining the strength and durability of the materials. The present work studied three stocks composed of Natural Rubber (NR), Styrene Butadiene Rubber (SBR) and Polybutadiene Rubber (BRcis) filled with carbon black N330. Three percentages of (NR/SBR/BRcis) were studied, namely (40/60/0), (40/50/10) and (40/40/20). The intent was to develop the Standard Italian Perilli Recipe (SPR) for Truck Tires Sidewall manufactured in Al-Dewaniya Tires Factory that have (30NR/70SBR) filled with carbon black N550. The results of constant amplitude loading have verified the applicability of the Paris law to the flexing fatigue behaviour of truck tire sidewall components. The accumulative fatigue damage was studied by the application of Miner’s rule to variable amplitude loading and gave unacceptable safe results at both sequence (L-H) and (H-L). The recipe that has (NR/SBR/BRcis) blending with percentages of (40/50/10) was generally the best in combined properties.

The purpose of writing the current paper is to identify and classify the driving affecting factors on customer relationship management. For measuring customer relationship management, we utilized 6 dimensions includes: knowledge management, technology, top management, personnel, service customizing and system integration. 2 questionnaires for identify and rank factors were designed and after proving their validity and reliability distributed participants. The results of applying Chi Square and Friedman tests show all dimension have positive and meaningful influence on customer relationship management. Finally by applying fuzzy TOPSIS technique, the sub criteria of customer relationship management were ranked in which “Reviewing and changing customers’ activities and other ones to achieve more customer orientation”, “Putting comprehensive information to customers about organizational services” and “Leading executive customer oriented plans by top managers” were selected as the most important sub criteria.

The conventional electric grid is continuously shifted towards technological transformation of Smart Grid. The gradually increasing electricity cost, inadequate infrastructure, electricity losses at various stages, carbon footprint and climate changes are some of the major player for paradigm shift towards smart grid. The smart grid is next generation grid network that promises advantage such as decentralized control, digitalization, flexibility, intelligence, resilience, sustainability, and customization. In this article, we are put forth some of pioneer development and challenges faced in the smart grid environment. This article also discusses the smart grid development regarding with Indian perspectives.

Soil, plant and indicators are the main criteria to recognize the function of natural ecosystems and evaluate their potentials. Rangeland ecosystem contains various patches with different functions. The structural and functional characteristics of fertilized patches in Bozdaghy rangeland, in North-Khorasan Province was measured and analyzed in this study. A group of measurable and simple indices of landscape function analysis (LFA) methods were used to evaluate these characteristics. The data were measured from seven land unit which is developed from overlaying of geology map on the dem and slope map. In this research the length and width of ecological patches by the forms of Grass, forb, shrub and bare soil with litter measured. Also we measured 11 soil surface parameters on three, 50 meters transects in the seven mentioned regions. These 11 parameters are belonging to 3 major attributes of soil: Stability, infiltration and nutrients. Statistical analysis of data using the software landscape function analysis, carried. Using multivariate analysis of variance and Duncan's test, functional characteristics associated with each of the land units were studied. Stability, infiltration and nutrients indices of Shrub, forbs and Grass showed significant differences in seven land unit (p<0.05). shrub was most important ecological indicators of areas.

The aim of the present study was to investigate the antimicrobial activity of the Cinnamomum cassia against the fungi, Penicillium notatum and Aspergillus niger. Cinnamomum cassia is the dried bark of an evergreen busy tree. It is commonly known as Cinnamon. Cinnamon bark is widely used as a spice. It is principally employed in cookery as a condiment and flavoring material. In the present study different concentration of the crude extracts samples of Cinnamomun cassia and media were prepared (i.e-10%, 20%, 30% and 40%) and one plate is maintained as Control which contains only MRBA(Martin Rose Bengal Agar) media and fungal culture, not the extracts of the Cinnamomum cassia, are poured onto the different petri plates. This was left to solidify for 20 minutes. With the help of cork borer one hole was made in the center of each petri plate. The Fungus cultures of A.niger and P.notatum with the help of cork borer were removed from the pure culture one by one. This was then inoculated onto the Petri plates containing different concentration of the Cinnamomum cassia samples. Petri plates were wrapped with paraffin and incubated .After incubation of 4days at room temperature with P.notatum and A.niger the growth of fungus was observed. It was observed that as increase in the concentration of the Cinnamomum cassia sample the growth is inhibited. The growth is very less at the 40% of the sample used. The growth was totally inhibited by the Cinnamon extract as 40% against the fungus P. notatum.