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Table of contents for the month of June 2018

Table of contents for the month of March 2017

We discuss two dark energy models on LRS Bianchi Type-I magnetized anisotropic space –time with a variable equation of state (EoS). The EoS for dark energy is found to be time dependent and its existing range for derive models is in good agreement with the recent observations. Using the suitable condition, the anisotropic models approach to isotropic scenario. We also find that during the evolution of the universe, the EoS parameter for DE changes from to in first model whereas from to in second model which is consistent with recent observations. The cosmological constant is found to be a positive decreasing function of time and it approaches a small positive value at late time (i.e. the present epoch) which is corroborated by results from recent supernovae Ia observations. The physical and geometric properties are also discussed.

Owing to the poor academic performances of students in Secondary Schools in Ekiti State, Nigeria, the study examined gender differences and the influence of parenting styles on the academic performances of secondary school students in Ekiti State, Nigeria. A sample of 116 participants comprising of 62 males and 54 females with ages ranging from 13 to 16 years and a mean age of 15.2 years was drawn from among the students of Christ School, Ado-Ekiti, Nigeria. The 20 items Parental Care Scale developed by Baumrind (1971) to measure what children perceive as the styles or approaches that their parents dominantly use in taking care of them was administered on the students and it was found out that parenting style influences children’s academic performances, with authoritative parenting style being most influential [ t (113) = 20.95, p <.01]. No significant difference was found in the academic performances of males and females owing to differing parental styles. Findings were therefore discussed in light of available literature and recommendations were made.

The study of fully developed mixed convection Couette flow of a nano fluid between two vertical parallel plates, with asymmetric thermal and nanoparticle concentration conditions at the walls, filled by a nanofluid has been studied. The nanofluid model used in this paper takes into account the lower plate moving velocity, Brownian diffusion and the thermophoresis effects and the analysis is based on analytical solutions. Analytical expressions for the fully developed velocity, temperature and nanoparticle concentration profiles as well as for the Nusselt and Sherwood numbers at the left wall of the channel are obtained and analysed.

We are very happy to announce that from 13th October 2017, Mr.K.Hari Krishna has joined the team of Elixir Editorial Advisory Board. He/She will carry a special responsibility for dealing with manuscripts based on Management. Mr.K.Hari Krishna working as Assistant Professor, Sphoorthy Engineering College, Naderul, Hyderabad, India. The appointment of Mr.K.Hari Krishna as member Editorial Advisory Board strengthens the links and will make it easier for prospective authors to establish contact with the journal. Please send any expressions of interest to elixirpublishers@gmail.com.

Power has been an important issue for the present day microelectronic circuits of Soc designs. In the entire phase of design controlling power and dealing with power dissipation is very important. There are six leakage components in a MOS transistor. About 50 % of the total power consumption is through leakage components alone. Out of this 40 % power dissipation is through transistors. Out of them subthreshold leakage and gate leakage are of important concern for sub 100 nm devices. In this work we presented the main leakages in a 6T- SRAM cell. Later we presented an existing variable body biasing method and its performance. We proposed two novel methodologies HSVR, GSVE to reduce the subthreshold and gate leakage components. These methods are toplogy based leakage reduction methods applied for leakage reduction in the circuit level. We observed considerable reduction of both the components through the proposed methods.

In submerged arc welding (SAW), selecting appropriate values for process variables is essential in order to control heat-affected zone (HAZ) dimensions and get the required bead size and quality. Also, conditions must be selected that will ensure a predictable and reproducible weld bead, which is critical for obtaining high quality. In this investigation, mathematical models were developed to study the effects of process variables and heat input on various metallurgical aspects, namely, the widths of the HAZ, weld interface, and grain growth and grain refinement regions of the HAZ. The color metallography technique and response surface methodology were also used.The thermal effect of Submerged Arc that specially depends on the electrical arc, flux type and temperature field of it in workpiece, is the main key of analysis and optimization of this process, from which the main goal of this paper has been defined. Numerical simulation of welding process in SIMPELC method and by ANSYS software for gaining the temperature field of copper, the effect of parameter variation on temperature field and process optimization for different cases of Submerged Arc are done. The influence of the welding parameter for each mode on the dimensions and shape of the welds and on their ferrite contents is investigated.

An efficient and adequate transportation system is one of the key indicators of a nation’s prosperity, its developmental status and overall economic growth. The roads pass through areas with extreme climatic conditions from heavy rainfall to desert conditions; diverse terrains from plains to extremely high mountains, plateaus and varying soil grades, rocky and gravelly to marshy land. Over the past four decades, the share of total rail and road traffic carrying passengers and goods is gradually increasing because of fast and ever-increasing industrial, commercial, and other socioeconomic development activities, the road transport vehicle population, especially the vehicles carrying goods, has also increased phenomenally during this period. Because of economies in road transportation, overloading by truck operators is common. The majority of the arterial road system experiences overloading, as much as 18 to 20-tonne axle loads versus the permissible legal limit of 10.2 tonnes. The existing road network has shown signs of premature distress because of the unexpected demands of growing traffic volume and heavier axle loads. The network has fallen short of its structural capacity and hence it is greatly overstrained. The majority of allocated funds are utilized for providing maintenance and rehabilitation measures to the existing network rather than for new construction. With this background, in the present study, a road section is identified in Kurnool district of Andhra Pradesh to carry out the pavement performance study on distresses. For the selected stretch, data was collected on rutting, ravelling, potholes, edge failures, traffic, etc. The detailed analysis was performed using NCSS statistical tool and to develop a pavement performance model for the selected stretch.

Jhansi is located in the plateau of central India, an area dominated by rocky reliefs and minerals underneath the soil. Barua Sagar is a historical place located about 25 km from Jhansi in Uttar Pradesh, India.  It is situated on the bank of the Betwa River; the place is named after the Barua Sagar Taal, a large lake created about 260 years ago when Raja Udit Singh of Orchha built the embankment. Present study has been undertaken to investigate the physico-chemical properties of Barua Sagar lake water to assess the utility of lake water for fish production, irrigation, drinking and aesthetic purposes etc. Water Quality Index (WQI) was applied in Barua sagar  Lake,  using different water quality parameters ( Temperature, pH, Dissolved Oxygen, Turbidity, Conductivity, Hardness, Alkalinity, Sodium, Biochemical Oxygen Demand (BOD), Chemical  Oxygen Demand(COD), Nitrate, Chloride, Iron, Free residual Chlorine, Fluoride, TS, TDS and TSS). The water body is divided in to five sites for proper sampling and collection of water sample from whole lake. The impact of various anthropogenic activities was evident on some parameters such as the EC, BOD and DO. It is suggested that regular monitoring of the lake water quality is necessary for proper management.