Archives-August 2012

Gradual development in power systems has caused so many problems in control and optimum using of electrical storage systems. Storing of electrical energy has made new capabilities in improving the current control methods. Quick access to these kinds of energies lets us direct control for supplying the consumers in electrical grid network. These methods are powerful to control and solve the current economical and technical problems of the compound and large power systems. On the other hand, using the various methods of direct energy storage can produce suitable capacity to store the electrical energy for the power industry. Among all of the energy storage systems, pumped storage power plants when they committed, because of their special characteristics, have a unique situation. In this paper, the feasibility assessment of the usage of pumped storage power plants for the Iranian grid has been discussed by WASP-IV program.

This study summarizes the steps for forecasting Natural gas consumption in Bangladesh’s power sector using Box-Jenkins autoregressive integrated moving average (ARIMA) time series model. For this study a structure for ARIMA forecasting model is being proposed where a time series is expressed in terms of past values of itself plus current and lagged values of a ‘white noise’ error term. Validity of the model was tested using standard statistical techniques and the best model is proposed on the basis of various diagnostic and selection & evaluation criteria. The findings of the study will provide policy makers in Bangladesh a long term perspective of natural gas consumption in power sector along with necessity of exploring other alternative energy sources and assist in adopting proper strategies to address the power supply situation of Bangladesh.

Copper (II) phthalocyanine and 2, 9, 16, 23 tetrakis nitro copper (II) phthalocyanine  has been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalysts. 4-Nitro phthalonitrile synthesized from phthalimide in three steps. The reaction time of ruthenium chloride and HZSM-5 catalysts was very shorter than ammonium molybdate and H? catalysts. The yield while we used ruthenium chloride and HZSM-5 catalysts were very higher than another. The newly prepared compound has been characterized by IR, UV-Vis, ¹HNMR and XRD spectra.

Dihydro-3,4-dihydroxy-5-(hydroxymethyl)furan-2(3H)-one has been prepared in two steps from galactose. The first step potassium-2,3,4,5-tetrahedroxypentanoate was obtained in 64% yield and the title compound has been isolated in next step with 75% yield. The structures of the products were characterized by IR, 1H, 13C, mass and microanalysis study.

The state of any system can be defined completely by four observable properties, namely composition, pressure, volume and temperature. Study of thermodynamical properties of liquids and liquid mixtures play an important role in elucidation of the nature of molecular interactions. Internal pressure (?i) and free volume (Vf.) are the thermo dynamical parameters, which are useful in understanding the intra and inter molecular interactions in polymer solutions[1,2]. The internal pressure is known to be an inverse function of free volume. In the present work, the ultrasonic velocity, density and viscosity measurements have been made for the temperatures 303K, 313 K, 318 K and 323 K and at different concentrations of polyvinylidene fluoride in polar aprotic solvent i.e Dimethylacetamide. The variation of internal pressure and free volume with temperature and concentration has been carried out. The nature of polymer-solvent interaction and the effect of temperature and concentration on the molecular interaction are studied. The internal pressure is found to vary inversely with free volume and the values reveals that the relation ?i Vf x = constant, holds good for the above system.

Designing of Very Large Scale Integrated Circuits (VLSI) operates at Megahertz and Gigahertz satisfying the design constraints for desired applications is a challenging job due to various reasons like transient time effect, high power requirement and consumption etc. Phase Locked Loop (PLL) is an important integrated circuit used in various areas of communications. Frequency synthesizers when used in Frequency Hopping Spread Spectrum (FH-SS) requires strict timing synchronization between transmitting and receiving system for successfully despreading and the power consumption is also high due to high frequency operation. In this contribution a new scheme has been proposed, in which frequency hopping transmitter and receiver has been operated at intermediate frequency and the same hopping rate was obtained as can be achieved by fast hopping spread spectrum operated at high frequency and therefore requires low speed frequency synthesizers and offers many advantages like more user capability, Low cost and simple amplifiers, filters, ADC and DAC converters requirement. The IFH-SS transmitter and receiver based on proposed intermediate frequency hopping spread spectrum has been experimentally verified. The results of experimental investigation have been presented in the paper. The waveforms obtained at various check nodes have also been presented.

Viscometric methods play a dominant role in studying the Polymer-Solvent interaction. Due to this interaction, there is an increase in viscosity of polymer solution over that of pure solvent. The intrinsic viscosity is the limiting value of the reduced viscosity at infinite dilution. The intrinsic viscosity has been used to study the extent of interaction between polymer and the solvent. In the present work, the intrinsic viscosity obtained through   adiabatic compressibility and viscosity data is applied to the solution of Poly Vinyl Pyrrolidone in polar solvent at 308 K, 313 K & 318 K.  Viscosity of the solvated part (?_s) is computed and its variation with molar concentration (n₂) is studied. The molar solvated volume (?_s) obtained from ?_s is compared with the values of ?_s computed using the traditional equation. The Huggin’s coefficients A_?   and B_? are determined from Viscosity study and compared with those obtained from solvation study.

We all have faced different learning experiences in life. Just go back a few years when you were sitting in the class, the professor or teacher teaching a subject. Suddenly he shoots up a question few hands goes up in the air and you are left wondering, why I am not able to grasp fast like them. With time the explanation you give to yourself ranges from “they being smart” to “me being not so smart”. This research paper gives an insight to a more rational reason for these differences. Which is - each person has their own learning styles and their own natural intelligences. This empirical research paper captures information based on Howard Gardner multiple intelligence questionnaire. The essence of it is as Howard believed is different individuals possess different multiple intelligence. And how these intelligences, provides the panacea by making use of this test, which can be considerably used by the HR managers while designing training program for the employees and designing the learning style of the individuals. This research paper will provide a powerful tool to be used during the employee training design.

An engaged employee is considered as a panacea for most of the organizational problems. This article focuses on the critical aspects of need for the engaged employee, how an organization can redesign its employee engagement drivers, with the use of different models available in literature. It reviews the traditional method, current studies and research performed on the employee engagement and views that human resource leaders needs to adopt the innovative way and real transformation that happens in corporate world to retain and engage employees to remain competitive in today’s global marketplace.

The study of liquid properties using spectroscopy and acoustic methods In the present investigation, non-aqueous solutions of constitutes mining field for scientists. L. Arginine are studied. FTIR spectra have been taken for the sample solutions. The observed vibrational spectra are analysed. Ultrasonic velocity and density are measured for different temperatures(278.15K to 328.15K) and at various molalities. Using the above measurements, adiabatic compressibility solvation number, apparent molal compressibility, apparent molal volume and equivalent conductivity are computed. From the computed results structural influence of the salt in the solvent is studied. The results obtained from spectroscopic study are corroborated with the acoustic behavior of the solutions.