Abstract

Fuzzy logic has gained wide acceptance as a useful tool for merging objectivity with flexibility particularly in the area of process control. Fuzzy logic is reminiscent of human thinking processes and natural language enabling decisions to be made based on vague information. This paper deals with the development of a fuzzy logic based system for the efficient working of Rubber Roll Sheller machine which is used in rice mills. The aim of this study is to determine important factors that affect the operation of Rubber Roll Sheller machine and utilizing them in a fuzzy based expert system in order to decrease the amount of grain breakage. This newly developed fuzzy based expert system is capable of improving the rice quality as the output of a Rubber Roll Sheller with minimum grain breakage.

Abstract

Isomorphism is an imperative topic in the field of mechanism. Isomorphism identification is a difficult problem in kinematic chains. There are number of method given by many researchers. This paper presents  the application of the [JJ] matrix proposed by Hasan A[1] for the identification of the distinct mechanisms (DM) from a given kinematic chain (KC). The method is based on the Joint —Joint matrix. The process  is fully computational and easy to apply for the purpose. With the help of this method, we can determine easily their distinct mechanism and identify the isomorphism of kinematic chains.

Abstract

Under normal operating conditions, catalytic converters appear to be the most effective means of reducing air pollution from SI engines. The conversion efficiency, however, declines very steeply for temperatures below about 350 °C and is practically zero during the starting and warming-up period. Improving the conversion efficiency under these conditions is important, particularly in large cities, where the number of starting per vehicle per day tends to be high. Among the other solutions are preheating of the catalyst electrically, warming up of the catalyst in an external combustion chamber, installation of an auxiliary small-capacity catalytic converter, and employment of an adsorbing unit between two catalysts. Although these methods are quite effective, their disadvantage lies in the fact that they require an external energy source, an additional component (a control unit) or a three-stage catalyst. An Cold-Start Emissions Adsorber System (CSEAS) for reducing cold-start emission (HC,NOx and CO) have been developed combining existing catalyst  technologies with a zeolite based Adsorber. The series flow in-line concept offers a passive and simplified alternative to other technologies by incorporating one additional existing converter with additional valving, purging lines and secondary air.

Important technical issues to be resolved for practical use of this CSEAS are,

1. The ability to absorb a wide range of HC, NOx and CO in the exhaust gas.

2. The temperature difference between emissions desorption from the Adsorber and activation desorbed emission.

The CSEAS reduced up to 100% of cold-start emissions beyond the three-way catalyst only base line system [1] . The in-line CSEAS could be one of the potential technologies to meet EURO-V and future regulations without the need for ancillary electrically and its associated costs.

Abstract

Wire electric discharge machine (WEDM) is a non conventional machining method to cut hard to machine material with the help of a wire electrode. High strength low alloy steel (HSLA) is a hard alloy with high hardness and wear resisting property. The purpose of this study is to investigate the effect of parameters on cutting rate for WEDM using HSLA as workpiece and brass wire as electrode. HSLA used in cars, trucks, cranes, bridges, roller coasters and other structures that are designed to handle large amounts of stress. It is seen that cutting rate increases with increase in pulse on time and peak current. Cutting rate decreases with increase in pulse off time and servo voltage. Wire mechanical tension has no significant effect on cutting rate. In order to evaluate the effect of selected process parameters, the Response Surface Methodology (RSM) is used to formulate a mathematical model which correlates the independent process parameters with the desired cutting rate. The central composite rotatable design has been used to conduct the experiments. The analysis of results indicates that the pulse on time, pulse off time, servo voltage and peak current have a significant effect on cutting rate.

Abstract

The fluid flow and thermal modeling of oil recovery from a porous medium is studied.A model using steady state 2dimension heat equation s developed.The model is solved by operator splitting and I order upwind schemes.

A thermal mixing layer forms at interface of the two streams in which the temperature changes gradually from 0 to ?.The thickness of this layer grows in the downstream direction.At high peclet numbers ,the mixing layer is thin and the temperature is not continuous.If Pe?0,the mixing layer spreads quickly to touch the boundaries For the fully evolved mixing layer it was found that the mixing layer thickness ? based on a temperature variation from 0.1 to 0.99 varies as ??pe=constant.

Abstract

Titanium alloys are difficult to cut materials due to their physical and mechanical properties. Cutting fluids are employed in machining in order to improve machinability, tribological characteristics, tool life, reduce tool wear, helps in carrying away the heat and debris produced during machining. The use of cutting fluids in machining leads to higher machining cost, hazards to operator and environmental issues. Alternatives have been investigated to reduce the use of cutting fluids in machining. One of the alternatives is machining with Minimum Quantity Lubrication (MQL), where the cutting fluid flow rate is 10 to 500 ml/hr. Tool wear plays an important role on the components like surface finish, dimensional accuracy and cost of tools. In order to minimize the tool wear, it is required to select proper cutting fluid, optimize the process parameters such as cutting speed, feed rate and depth of cut while machining on titanium alloys. This paper deals the effect of process parameters and optimization of process parameters in turning of Ti-6Al-4V alloy under different cutting fluids such as Vegetable, Synthetic and Servo cut oils with Minimum Quantity Lubrication (MQL) and found that with synthetic oil, tool wear is low compared to vegetable and servo cut oils. It is observed that the high cutting speed at 580 rpm, moderate feed rate at 0.167 mm/rev and high depth of cut at 1.6 mm are found to be optimum cutting conditions. From ANOVA, It is observed that feed rate has major contribution in optimization of process parameters.

Abstract

Prediction of surface errors in milling of thin-walled structures is not trivial due to cutting force induced deflections of workpiece. The situation becomes more complicated when the end mill adds cutter deflection errors to workpiece deflection. It is important to predict and analyze such variation of surface error from process planning and process control point of view. The study of surface error is also essential while overcoming the same by applying various compensation methods. This paper investigates cutter and workpiece deflection induced surface errors in peripheral milling of thin-walled straight and curved geometries. A flexible tool-workpiece system has been developed to estimate surface error in the presence of both tool and workpiece deflections. The effects of chip load and workpiece curvature on surface errors have also been investigated by using experimental and computational methodology. Based on the outcomes of the present study, it is concluded that the complex nature of tool and workpiece deflection induced surface error can be predicted both qualitatively and quantitatively in thin-walled machining. The results presented here provide useful insights into qualitative and quantitative nature of surface errors which will be helpful for product designers as well as process planners in improving machining productivity without sacrificing quality.

Abstract

A finite element model, based on first-order shear deformation theory, is used in this study for the free vibration analysis of laminated composite plates. In this paper, the free vibration analysis of laminated composite plates are studied for different support conditions, aspect ratio, lamination scheme, material anisotropy, span to thickness ratios and stacking sequences. It is revealed that the first-order shear deformation theory provides reasonably dependable results for natural frequencies of laminated composite plates.  The good agreement with other methods demonstrates the validity and the reliability of the proposed method.