Archives-December 

In this study, comparison between two controllers i.e. PID controller and fuzzy logic controller is done for the proposed dc-dc closed loop boost converter. The simulation, modeling and stability analysis of DC-DC Boost converter for Solar Electric system is done using space averaging technique in order to study its time domain, frequency domain and pole-zero domain analysis. A feedback controller for DC-DC boost converter is Designed to obtain constant output voltage of 24 V.A fuzzy logic controller is later used to control the output voltage of the boost converter. Simulation results show that fuzzy logic controlled boost converter has fast transient response, better steady-state response, and the proposed converter is less sensitive to load changes as compared to that of PID controller.

The aim of this paper is to examine the issue convergence of per capita income of North Africa countries to the per capita income level of countries in Southern Europe. We have applied tests of sigma-convergence and polynomial beta-convergence of Chatterji to assess convergence. We have applied the multiple endogenous breaks test advocated by Bai & Perron (2003) in order to evaluate the sigma-convergence hypothesis. According to our results, the process of sigma-convergence is not uniform over time. There exists a movement of convergence of per capita income of NA countries towards the income level of countries of Southern Europe during the period 1980-1984. The estimate of convergence clubs can refine the results for countries that have started catching up. This test rejects the hypothesis of beta-convergence on the whole period (1980-2007). If the model is estimated for each country, then there is a movement of beta-convergence only for Tunisia and Morocco on the period 1985-2000.On the other sub-periods, the assumption of divergence is accepted. The per capita income level of countries of Southern Europe does not seem to be a target toward which converge the countries of the NA region in the long term.

The performance of a computer system is heavily dependent on the characteristics of it’s interconnect architecture. A poorly designed system bus can throttle the transfer of instructions and data between memory and processor, or between peripheral devices and memory. This communication bottleneck is the focus of attention among many microprocessor and system manufacturers have adopted a number of bus standards. Hence memory access time has been a bottleneck which limits system performance. Memory controller (MC) is designed to tackle this problem. The Advanced Microcontroller Bus Architecture (AMBA) specification defines an on chip communications standard for designing high-performance embedded microcontrollers. This paper focuses on how to build an AMBA Advanced High performance Bus (AHB) based memory controller that can work efficiently in multi- master and multi- slave communication model.

Hair loss (technically known as alopecia) is a loss of hair from the head or body. Baldness can refer to general hair loss or male pattern baldness specifically. Some types of baldness can be caused by Alopecia areata, an autoimmune disorder. Eclipta alba (Asteraceae), Bacopa monnieri (Plantaginaceae), Trigonella foenugraecum (Fabaceae) are well known Ayurvedic herbs with purported claims of hair growth promotion. Hair formulation of Eclipta alba 10% w/v, Bacopa monnieri 10 % w/v, Trigonella foenugraecum 5 % w/v concentration in the form of herbal oil were studied and showed excellent hair growth activity with standard (2% minoxidil ethanolic solution) in wister albino rats. Hair growth initiation time was significantly reduced to half on treatment with the oil, as compared to control animals. The time required for complete hair growth was also significantly reduced. Quantitative analysis of hair growth after treatment with oil exhibited greater number of hair follicles in anagenic phase i.e. 82 which were higher as compared to control (52). The results of treatment with oil were better than the positive control minoxidil 2% treatment. It holds the promise of potent herbal alternative for minoxidil.

Teaching grammar has always been an area of concern for the practitioners and EFL/ESL teachers. While it seems more commitment has been given to this task, yet there is still room for more attention to innovative methods of grammar instruction which can help learners practice grammar through working on a combination of meaning and form which makes grammar learning more meaningful. The idea of teaching grammar as "Dictogloss Method" comes from a paper by Ruth Wajnryb (1990) in which learners use their grammar resources to reconstruct a text and become aware of their shortcomings and needs through learning-based procedure in which noticing, hypothesis-testing and metatalk are involved. This research is an attempt to find out if teaching grammar through Dictogloss method will significantly help Iranian EFL learners develop their grammatical competence. This study was based on a quasi-experimental research strategy with a pre-test post-test control group design. Eighty intermediate EFL students studying English at Sana'ato Ma'adan Language Institute (Isfahan) with the age range of 16-18, participated in this study. The performance of the learners who were exposed to Dictogloss method in the experimental group was compared with that of control group which did not undergo such a procedure. The analysis of the data indicated that utilizing Dictogloss method in experimental group helped the participants improve their grammatical competence upon verb tense usages significantly. In addition, the results suggested that Dictogloss can provide learners with opportunities to use their productive grammar in the task of text creation and meaningful communication.

In India, the wastewater at large from distilleries is known as spent wash, which is highly acidic in nature. In India 2004, distillery industry number has gone up to 319, producing 3.25x109 l of alcohol and generating 40.4x1010 l of wastewater annually (Uppal, 2004). Because of using large quantities of water in distillery industries it is essential to treat and reuse their waste water. In the most of time the discharge standards applied for distilleries are often too tough and below the level that can be achieved with appropriate biological treatment technologies (Pant and Adholeya, 2007a,b). In distillery industry, the production and characteristics of spent wash is highly variable and dependent on feed stocks and various aspects of the ethanol production process. The molasses spent wash (MSW) is a potential water pollutant in two ways. First, the highly coloured nature of MSW can block out sun light from rivers and streams thus reducing oxygenation of the water by photosynthesis and hence becomes injurious to aquatic life. Secondly, it has a high pollution load which would result in eutrophication of contaminated water sources (FitzGibbon et al., 1998). The first reason is due to the presence of water soluble recalcitrant colouring compound called melanoidin (Evershed et al., 1997). Melanoidin are dark brown to black coloured natural condensation product of sugar and amino acids produced by nonenzymatic browning reactions called maillard reactions (Plavsic et al., 2006). Ohmomo et al. (1988a) concluded that microbial decolourization of melanoidin is due to two decomposition mechanisms; in the first the smaller molecular weight melanoidin are attacked and in the second the larger molecular weight melanoidin are attacked. Satyawali and Balakrishnan (2008 a b) have investigated that the degradation of low molecular weight compound occurred in the membrane bioreactor (MBR) while the higher molecular weight compounds comprising the colour imparting melanoidin remained unaffected. As melanoidins are recalcitrant to biodegradation, the elimination of colored effluents in molasses-based distillery wastewater treatment system is mainly based on physical or chemical procedures such as adsorption, coagulation, precipitation, and oxidation. Although these methods are effective, they suffer from such short coming as requiring high reagent dosage, high cost, and formation of hazardous byproducts and intensive energy consumption.

The distribution of selected hydrophytes and their pollen morphology was carried out in six water bodies of Puducherry outskirts during the years 2006-07. Fifteen angiosperm species belonging to fifteen genera and fifteen families were identified (Aeschynomene indica, Aponogeton natans, Eichhornia crassipes, Ipomoea aquatica, Limnophila polystachia , Ludwigia adscendens, Nelumbo nucifera, Neptunia oleracea, Nymphaea pubescens, Nymphoides hydrophylla, Ottelia alismoides, Persicaria pulchra, Pistia stratiotes, Scirpus articulatus, Typha angustata). Many of the species observed were found in all the places studied. The mean number of pollen production per anther ranged from 847 to 41416. The pollen grains are mostly apolar or isopolar rarely heteropolar. The shape is commonly spheroidal or oblate-spheroidal rarely boat shaped (Nymphaea pubescens) and sub-prolate (Nelumbo nucifera). In Typha angustata the pollen grains are found in tetrads. Similarly exine sculpturing is also extremely varied ranging from reticulate to regulate. Apertures are mostly colpate or porate. The present study for the first time documents the diversity and pollen morphology of selected species in water bodies of the coastal environs.

In present year ad-hoc parallel data processing has emerged to be one of the killer applications for Infrastructure-as-a-Service (IAAS) clouds. Major Cloud computing companies have started to integrate frameworks for parallel data and making it easy for customers to access these. However, the processing frameworks which are currently used have been designed for static, homogeneous cluster setups and disregard the particular nature of a cloud. Consequently, the allocated compute resources may be inadequate for big parts of the submitted job and unnecessarily increase processing time and cost. In this project the data processing framework to explicitly exploit the dynamic resource allocation offered by today’s IAAS clouds for both, task scheduling and execution is constructed. Particular tasks of a processing job can be assigned to different types of virtual machines which are automatically instantiated and terminated during the job execution.

Heat pipe is a device which absorbs heat from hot junction and transfer heat to other junction. If space available is more than straight heat pipes are used but when space availability is problem in electronic circuits or cards bend heat pipes are used. According to investigation it is found that bend heat pipes of angle 90 and 120 degree are most suitable in electronic systems. Experimental analysis of bend copper heat pipes for different orientations which are suitable in electronic circuits mostly are taken for study and effect of bend Angle and heat transfer rate is calculated on a test rig by using methanol as a working fluid . Study is done on bend copper Heat pipe having 8 mm diameter and length 180 mm long and find out most suitable bend heat pipe and maximum heat transfer rate.

Heat pipes are heat transfer devices that enhances large amount of heat which works on the principle of evaporation and condensation of a working fluid. Inspite of wide application of heat pipe in microelectronics cooling system the trend of the chips performance and power utilization has been increased each year and a complete understanding of mechanism has not yet been completed even though it has the ability to operate against gravity and a greater maximum heat transport capability. This paper gives you a detailed literature review about the various parameters that affect the operational characteristics of circular heat pipe. Moreover the thermal resistance and heat transfer capability are affected by the choice of working fluid, the tilt angle, the fill ratio, thermal properties, angle of inclination and heat input.