Archives-August 2011

Corrosion inhibition of mild steel in 0.5 M H₂SO₄ was investigated in the absence and presence of different concentrations of extract of Crossandra infudibuliformis leaves [C.I.L]. Weight loss measurements and electrochemical studies were employed. The results obtained show that the inhibition was found to increase with increasing concentration of the plant extract. The inhibitive actions of plant extract are discussed on the basis of adsorption of stable complex at the mild steel surface. Theoretical fitting of different isotherms were tested to clarify the nature of adsorption. Polarization curves revealed that C.I.L inhibitor acts as mixed type inhibitor and the inhibition efficiency up to 96.40% was obtained.

Various ethyl-2-(2- substituted phenyl hydrazono)-3-oxobutyrate (2a-h) condensation with isonicotinyl hydrazide (i.e. isoniazide) (3) to 1-isonicotinoyl-3-methyl-4-(2-substituted phenylhydrazono)-1H-pyrazol-5(4H)-one (4a-h). The structures of all these compounds (4a-h) were recognized on basis of analytical and spectral data. The newly synthesized compounds were evaluated for their antimicrobial activity against various bacteria and fungi.

One of the most important natural resources that cover much of the earth's surface is soil. Most life on earth depends upon the soil as a direct or indirect source of food. Plants are rooted in the soil and obtain nutrients from it. Animals also get nutrients from eating the plants on the soil. Soil is home of many organisms such as seeds, spores, insects, and worms. The contents of soil change constantly and there are many different kinds of soil. It forms very slowly and is destroyed easily, so it must be conserved in order to continue to support life.

This research examines the effects of nationality on attitudes of students to study science and mathematics. The main aim is to identify attitude variations of the students living in different geographical areas of the world with particular focus on students from developing and developed countries. It compares data from ‘Trends in International Mathematics and Science Studies’ (TIMSS) 1996, 1999, 2003, 2007, ‘Relevance of Science Education’ (ROSE) 2004, ‘Programme for International Students Assessment’ (PISA) 2003, 2006, ‘Science and Scientists’ (SAS) 2002. Findings make it clear that students are positive internationally but students in developing countries are more positive than the students in rich and developed countries in science, mathematics, biology and physics with chemistry as an exception. Overall East Asian students are lowest in their attitude scores in integrated science followed by Australia, North America and Western Europe while South East Asian and African Students are on other end followed by North Asia, and Middle East. It is also observed that the students’ interest in science subjects is increasing with the years. For mathematics again the students of East Asia are lowest in their average scores in all international studies followed by West Europe, Australia and East Europe. On the other end are the nations like Africa, South East Asia, and Middle East. It was suggested that instead of only measuring level and dimension of attitudes, large-scale projects must look for the factors behind the tremendous variance that exists among countries, as well as how and when these attitudes change.

Polyaniline/ poly(o-toluidine) /MMT-clay nanocomposites can be prepared by mechano chemical method in which, interaction of precursor anilinium ion into the clay lattices accomplished by mechanical grinding of Na-MMT in presence of anilinium hydrochloride at room temperature using mortar and a pestle for about 30 minutes and subsequent grinding with oxidizing agent, ammoniumperoxysulphate. The appearance of green colour indicates the formation of polyaniline/ poly (o-toluidine)/ MMT-clay nanocomposites. The morphology and structural characteristics of the polyaniline clay nanocomposites were investigated using FTIR, XRD, Cyclic voltammogram and SEM.

This paper expounds processes of read understood and information transferred from epistemology and ontology according to customers’ requirements of knowledge service. It points out that method frames of content contrast were to access knowledge points via study on definition of knowledge and forms of semantic description. Some literatures would be contrasted with couple to couple by computer technology in order to raise read understanding efficiency.

In the fast growing Quartz watch segment there are many competitors in the market environment for TITAN who captured the market with their innovative and energetic strategies. Nowadays, the quartz watch market has been emerged with global competitors and others with introduction of their style and fashion watches in India. In view of the background, this research tries to examine the present marketing strategy of TITAN and to suggest an improved system for widening the market base and also to increase the sales volume. The purpose of the study also includes to the awareness level of TITAN quartz watch from the public. The sampling method adopted is non – probability convenience sampling. To analyse the data and interpret the results, various statistical tools like simple percentage analysis, Chi – square Test and ANOVA – one way are applied.

The decision Mechanism is the concluding phase of any decision making process. This paper discusses on the different methodologies available for implementing the decision mechanisms. The paper preambles with a brief description on set of conventional MCDM techniques like Analytical Hierarchy Process (AHP), Simple Additive weighting Method (SAW) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), Grey Rational Analysis (GRA), along with benefits and limitations of each technique. The different intelligent/soft computing techniques that are widely used in decision making processes like fuzzy logic, neural networks are discussed and finally confines the discussion is confined to the different neural network (NN) based decision support systems. The paper proposes an architecture for fuzzy neural network based call admission control decision mechanism for heterogeneous wireless networks environment.

Constructed wetlands (CWs) have a great potential for the treatment of wastewater. These systems consist of beds or channels which have been planted with helophytes (water loving plants), which rely upon physical, chemical and biological processes to remove contaminants from wastewater. CWs are generally classified into two categories: surface-flow and subsurface-flow. Both the systems are capable of removing nitrogen, phosphorus, biochemical oxygen demand, chemical oxygen demand, total suspended solids, metals and pathogens from different types of domestic and industrial wastewaters. This paper provides a review of the mechanism of removal of contaminants from wastewaters in the root zone of constructed wetlands which includes both aerobic and anaerobic microbiological conversions, sedimentation, mineralization, chemical transformations, physicochemical adsorption, chemical precipitation and ion exchange. This technology act as a natural and low cost treatment facility for wastewaters of different origin.

A new hybrid approach of Genetic Algorithm (GA) with local search algorithm is proposed to solve Course Timetabling Problems (CTP). In which, GA architecture is enhanced by proposing various selection, crossover and mutation operators. Diversity in population helps to get global optimum. In order to accommodate diversity of population and to avoid local optima, grade selection and combinatorial partially matched crossover operators are proposed. To increase the convergence rate and to produce guaranteed result, various mutation strategies are proposed with gene tuning approach. To improve the quality of the solution, steepest ascent hill climbing local search algorithm has been proposed. With these, hybrid approach with enhanced GA is implemented on CTP and hence its quality is proved by getting more promising and consistent results in all operations of the possible twelve combination of GA proposed operators. Also, proved experimentally that combination of grade selection, combinatorial partially matched crossover and adaptive mutation strategy operators is performing the best among all twelve proposed combinations and a combination of operators from the literature by yielding the average relative convergence rate as 31% which is greater than all others’ convergence rate.