The ultrasonic velocity, density and viscosity have been measured for the liquid mixtures of cresols namely, m-cresols, o-cresols and p-cresols with N,N-Dimethyl formamide (DMF) in CCl4  at 303, 308 and 313K. The experimental data have been used to calculate the acoustical parameters such as adiabatic compressibility (β), free length (Lf), free volume (Vf), internal pressure (πi), acoustic impedance (Z) and molar volume (Vm). The excess values of some of the above parameters have also been evaluated and fitted to Redlich-Kister Polynomials and the results are interpreted in terms of molecular interactions present in the mixtures.

Unsteady flow of a Bingham fluid in contact with a Newtonian fluid between two permeable beds of different permeabilities is studied. We used the Brinkman model for this problem. Expressions for the interface velocity, velocity distributions in the porous and non-porous regions and mass flow rate are obtained. These expressions are evaluated numerically for different values of the parameters.

In early stage of civilization, people constructed mostly masonry buildings based on those low-engineered and empirical approaches. In design of new buildings, the structural behaviour of masonry elements is of interest mostly in case of infilled frames or mixed RC frames, where masonry element are also being utilized as participating in structural behaviour of the building. The infilled frames show larger ductility than isolated masonry walls. Very few codes have made provisions on RC frames with brick masonry infill. Euro code (8) and Nepal Building Code (201) make some provisions for ordinary building up to three storey in the low seismic zones, whereas the Indian seismic code IS: 1893 recommends linear elastic analysis for the bare RC frames excluding the effect of brick infill. In the present case study, the author makes an attempt to evaluate contributions of such infill on RC frames using the literature of Aliaari (2005) and effectively utilizes in design of mixed masonry RC frame structures.

We proposed an inverse method, using a simply supported circular plate under lateral concentrated load, for the simultaneous determination of two elastic constants E and u from strain data of two-element strain-gage rectangular rosette. Several series and different position of strain-gauges provided full field information about strain field of the plate. An overdeterministic approach using least-square method is implemented to fit the experimentally determined strain field to the theoretical solution. Accuracy of the proposed method is verified experimentally.

Neural networks are often used as a powerful discriminating estimator for tasks in system identification. This paper describes a neural-network-based method relies on the Radial Basis Function Network (RBF network), for estimating the variable damping factor C (n) and spring constant K (n) of a weighting platform that first learns key properties of the step response of the weighting platform and then predicts the damping factor C (n) and spring constant K (n) of other systems with different step responses before the platform settled to the steady state. In the simulation and the experimental results, with the related applied masses, the correlation rates between the actual C(n), K(n) and estimated C(n) and K(n) are presented that shows the success of this method.

Abstract:

Tool wear monitoring is of great concern in machining industry, as it affects the surface qualities, dimensional accuracy and production costs of the machined components. The orthodox methods of measuring tool wear are time consuming and limited in accuracy and application. In this study, machine vision system based on digital image processing was developed for measurement of tool wear. The basic components of the system are: a charge coupled device (CCD) camera, PC, Microsoft Windows Video Maker, frame grabber, Video to USB cable, digital image processing software (Photoshop and digital image processing toolbox for MATLAB), multi-directional insert fixture, and light source. Tool wear images were captured and ten different wear features: length, width, area, equivalent diameter, centroid, major axis length, minor axis length, solidity, eccentricity and orientation were extracted from the images. The pixels dimension of the system was found to be Px = 0.03306 and Py = 0.03333. The accuracy of the system compared to SANDVIK Coromant hand-held microscopic lens was found to have an absolute error less than 3.13%. The system has been applied in the analysis tool wear of uncoated cemented carbide inserts used for turning of NST 37.2 steel. A tool wear index (TWI) was proposed as a potential indicator for tool wear monitoring. A graphical user interface (GUI) was designed for easy application of system.

This paper describes the problem of voltage sags and swells and its severe impact on non linear loads or sensitive loads. The dynamic voltage restorer (DVR) has become popular as a cost effective solution for the protection of sensitive loads from voltage sags and swells. The control for DVR based on dqo algorithm is discussed. The proposed control scheme is simple to design. Simulation results using Matlab/Simulink are presented to illustrate and understand the performances of DVR in load voltage compensation.

Abstract:

The controllability of torque in an induction motor without any peak overshoot and less ripples with good transient and steady state responses form the main criteria in the designing of a controller. Though PI controller is able to achieve these but with certain drawbacks as the gains can not be increased beyond certain limit so as to have an improved response. Moreover, it introduces non linearity into the system making it more complex for analysis. Also it deteriorates the controller performance. With the advent of artificial intelligent techniques, these drawbacks can be mitigated. One such technique is the use of Fuzzy Logic in the design of controller either independently or in hybrid with PI controller. This paper proposes a unique set of fuzzy logics for the speed controller design to be used in vector controlled three phase induction motor. The results obtained from the model using proposed Fuzzy Logic Controller and PI Controller are compared. It can be concluded that use of Fuzzy logic improves and smoothens out the ripples in the motor torque and stator currents. It also facilitates in limiting the magnitude of the torque and current values within the specified range in any kind of disturbance, either provided by the speed removal or by sudden application and removal of load torque. This has been verified through the simulation results of the model built completely in a MATLAB/SIMULINK environment.

Abstract:

Geopolymer is a class of aluminosilicate binding materials synthesized by thermal activation of solid aluminosilicate base materials such as fly ash, metakaolin, GGBS etc. with an alkali metal hydroxide and silicate solution. These binders are currently attracting widespread attention due to their potential utilization as a high performance, environmental friendly and sustainable alternative to Portland cement. The present paper reports results of an experimental study on development of compressive strength and microstructure of geopolymer paste and mortar specimens prepared by thermal activation of Indian fly ash with sodium hydroxide and sodium silicate solution. The effect of main synthesis parameters such as alkali content(Na2O/Al2O3), silica content (SiO2/Al2O3), water to geopolymer solid ratio and sand to fly ash ratio of geopolymer mixture and processing parameters such as curing time and curing temperature on development of compressive strength and microstructure of fly ash based geopolymer paste and mortar were studied. The compressive strength of 48.20MPa was obtained for geopolymer mixture cured at 850C for 24 hours with alkali content of 0.62 and silica content of 4.0. The mineralogical and microstructure studies on hardened geopolymer performed by means Scanning electron microscope (SEM) and X-ray diffraction (XRD), showed formation of a new amorphous alumino-silicate phase such as hydroxysodalite and herschelite influenced development of compressive strength. The results obtained in the current research will be useful for developing of mix design guidelines for commercial exploitation of the new binding material.

Abstract:

Energy study was conducted in an organic fertilizer plant in Ibadan, Nigeria, to determine the energy requirement for production of both powdered and pelletised organic fertilizer. The energy consumption patterns of the unit operations were evaluated for production of 9,000 kg of the finished products. The analysis revealed that eight and nine defined unit operations were required production of powder and pellets, respectively. The electrical and manual energy required for the production of powder were 94.45 and 5.55% of the total energy, respectively, with corresponding 93.9 and 5.07% for the production of pellets. The respective average energy intensities were estimated to be 0.20 and 0.35 MJ/kg for powder and pellets. The most energy intensive operation was identified as the pulverizing unit with energy intensity of 0.09 MJ/kg, accounting for respective proportions of 33.4 and 27.0% of the total energy for production of powder and pellets. Optimization of the pulverizing process is suggested to make the system energy efficient.

Abstract:

Green concrete capable for sustainable development is characterized by application of industrial wastes to reduce consumption of natural resources and energy and pollution of the environment. Marble sludge powder can be used as filler and helps to reduce the total voids content in concrete. Natural sand in many parts of the country is not graded properly and has excessive silt on other hand quarry rock dust does not contain silt or organic impurities and can be produced to meet desired gradation and fineness as per requirement. Consequently, this contributes to improve the strength of concrete. Through reaction with the concrete admixture, Marble powder and quarry rock dust improved pozzolanic reaction, micro-aggregate filling, and concrete durability. This paper presents the feasibility of the usage of Quarry Rock Dust and Marble sludge powder as hundred percent substitutes for Natural Sand in concrete.  An attempt has been made to durability studies on Green Concrete compared with the Natural Sand concrete. It is found that the compressive, split tensile strength and Durability Studies of concrete made of Quarry Rock Dust are nearly 14 % more than the conventional concrete. .  The concrete resistance to sulphate attack was enhanced greatly. Application of Green Concrete is an effective way to reduce environment pollution and improve durability of concrete under severe conditions.

Abstract:

This paper presents hunting network method to analyze the behavior of poly-phase induction machine under the influence of a periodic pulsating torque. The differential equation, which describes the dynamic behavior of induction machine, is nonlinear and until the advent of mechanical differential analyzer in the early 1940’s, it was not feasible to solve these equations. Now solution of these equations is common place using either digital or analog computers. In this paper digital simulation of induction machine dynamics using MATLAB package is analyzed. The calculation method is outlined to predict the current, power and torque pulsation along with power factor and slip. While considering induction generator driven by a diesel engine, a large error can occur in the prediction of current, power and torque pulsation if the induction generator steady state characteristics are used in the analytical solution. A numerical solution in which the induction generator is analyzed by using hunting network method.

Abstract:

Nanocrystalline soft magnetic materials are interesting from both the fundamental and applied viewpoints. Because of various superior mechanical, magnetic and electrical properties, in comparison with those of the crystalline state, these alloys (metallic glasses) form a class of technologically important materials. In order to study the effect of Nb on the magnetotransport properties of the nanocrystalline soft magnetic material (Fe0.9Co0.1)73.5-Cu1-Nb3-Si13.5-B9, temperature and field dependent resistivity as well as magnetoresistance have been measured using conventional four-probe technique. This alloy exhibits metallic behavior in the high temperature range due to the formation of microcrystallites around the crystallization temperature Tx since more and more conduction electrons participating in the conduction mechanism. The value of magnetoresistance is found to vary (1~15%) at different temperatures (28°C~ 240°C). The complex permeability of this magnetic alloy has been measured for both as cast and annealed samples. Permeability measurement has been taken at low frequency (1 KHz-13 MHz). The permeability is found to be in the order of 104. The real part of the complex permeability is found to increase while the imaginary part is found to decrease with annealing temperatures due to local segregations. The best response is obtained for the sample annealed at 450°C for 5 minutes only. The overall permeability of the sample has low value when annealed at 450°C for 1 hour. The frequency range where the sample can be useful as a soft magnetic material is found out as 10 KHz to 1MHz. The magnetization of the sample has been measured as a function of magnetic field at room temperature (28°C) using a vibrating sample magnetometer (VSM). Saturation magnetization for the sample is observed to be around 179emu/gm.

Abstract:

In the design of frequency-selective filters, the desired filter characteristics are specified in the frequency domain in terms of desired magnitude and phase response of the filter. In this paper we present a design approach by determining the closely approximated coefficients using powerful Evolutionary Programming to find the solution for the optimization problem in selecting the coefficients. In this paper the design of Causal FIR filter with desired frequency response and phase response is presented. In practice, FIR filters are employed in filtering problems where there is a requirement for linear phase characteristics within the passband of the filter. The Evolutionary Programming is the best search procedure and most powerful than Linear Programming in providing the optimal solution that is desired to minimize the ripple content in both passband and stopband. We presented here how the values of δ1 and δ2 are minimized with best optimized approach using Evolutionary Computation. The optimized filter bank structure is implemented in our research work for effective compression of images.