Mechanization and Import Substitution in Zimbabwean Farmers' Equipment: A Case Study of the Revitalization of an Abandoned Tractor Trailer
Drill String Vibrational Analysis and Parametric Optimization for a Portable Water Well Rig Development
An Efficient Deep Neural Network with Amplifying Sine Unit for Nonlinear Oscillatory Systems
The Occupational Directness of Nanorobots in Medical Surgeries
Recent Trends in Solar Thermal Cooling Technologies
Design of Oil-Ammonia Separator for Refrigeration Systems
A Review on Mechanical and Tribological Characteristics of Hybrid Composites
Design and Experimental Investigation of a Natural Draft Improved Biomass Cookstove
Progressive Development of Various Production and Refining Process of Biodiesel
Optimization of Wire-ED Turning Process Parameters by Taguchi-Grey Relational Analysis
Evaluation Of Mechanical Behavior Of Al-Alloy/SiC Metal Matrix Composites With Respect To Their Constituents Using Taguchi Techniques
Multistage Extractive Desulfurization of Liquid Fuel by Ionic Liquids
Isomorphism Identification of Compound Kinematic Chain and Their Mechanism
Development of Electroplating Setup for Plating Abs Plastics
A Comprehensive Review of Biodiesel Application in IDI Engines with Property Improving Additives
A numerical technique for solving time and robust time-optimal control problems has been presented. The method relies on the special feature that the optimal control structure contains as many free parameters as there are interior or boundary conditions. Two Boundary Value Problems (BVPs) are formulated for the state variables and co-states independently, thus, reducing the dimension of the original problem into half. Then, a numerical algorithm is developed, that is based on the shooting method, to solve the resulting BVPs. The computed optimal solution is verified by comparing the control input resulting from the first BVP with the switching function obtained by solving the second BVP. Next, the numerical technique is modified to solve robust time-optimal control problems. The capability of the proposed method is demonstrated through numerical examples, whose output optimal solution is shown to be identical to those presented in the literature. These examples include linear as well as non-linear systems. Finally, the numerical technique is utilized to design a time-optimal control for a rest-to-rest maneuver of flexible structure while eliminating the residual vibrations at the end of the maneuver.
Wire Electric Discharge Machining (WEDM) is a thermal-erosion process to machine the hard to cut conductive material. This process is used for complex shapes, which have sharp edges that are difficult to machine using conventional machining processes. SKD11 is used as a work piece and performance analysis is done to find out the significant control factors for SKD11 by using one factor approach at a time. In this research paper, effect of various control factors like pulse on time, pulse off time, servo voltage, peak current, water pressure, wire tension, wire feed, peak voltage and, servo feed on cutting rate has been investigated while machining on SKD11 using one variable at a time approach. Experiments show the response for different parameters on WEDM. Cutting rate increases as the pulse on time and peak current increases. Cutting rate decreases with the pulse off time and servo voltage increases. Wire feed and wire tension has no effect on cutting rate.
The available fuel sources in the market are less than demand, therefore the alternative fuels are substitutes for different commercial and residential applications, such as diesel and petrol for automobiles. Currently, many countries need to import significant amount of crude oil and other petroleum products. Also the air pollution is another environmental problem caused by the pollutant emissions from the automobiles running on petroleum products. The biogas is a renewable clean fuel that can potentially replace the traditional petroleum fuels in the future. Biogas contains 55% CH4, 40.5% Co2, and 4.5% pollutants including H2, N2, H2S, and O2 to minimize the pollutant amount. Biogas can be processed by going through the enrichment system of scrubbing and bottling mechanisms to produce Bio-CNG gas for automobiles. Biogas can be widely utilized after performing purification process to remove pollutants. The pure Bio- Methane in this analysis is pressurized to 19.5 MPa to fill in CNG cylinder by compressor. The capacity of producing Biogas is about 148 m3 daily and Biogas production efficiency will rely on environment and other conditions. The design analysis of bio-reactor in this biomass system is accomplished by performing the mathematical modeling, computer aided simulation, and prototype experiment.
Fluid Catalytic Cracking Unit (FCCU) is an important processing unit in an oil refinery. Fluid catalytic cracking is a process used to convert heavy petroleum products to light products such as gasoline, light fuel oil, and petroleum gas. In the fluid catalytic cracking reactor, heavy gas oil is cracked into more valuable lighter hydrocarbon products. The reactor input (the gas oil feed to the reactor) is a mixture of hydrocarbons that makes the reaction kinetics very complicated due to the involved reactions. The process is highly nonlinear and multi variable with severe interactions. For the simulated dynamic model of FCCU plugged with yield model, sensitivity studies has been carried out to study the effects of independent variables such as feed preheat temperature, feed flow rate and air flow rate in maximizing gasoline yield. With the optimized model, the closed loop studies have been carried out for reactor and regenerator temperature control of FCCU with minimum overshoot as the performance criteria.
AISI 304 stainless steel has wide applications in fabrication, architectural panelling, paper industry, food and pharmaceutical production equipment, nuclear vessels and cryogenic vessels. Austenitic steels are hard materials to machine, due to their high strength, high ductility, low thermal conductivity and excellent corrosion resistance in a wide variety of environments. This paper presents optimisation of machining parameters for milling AISI 304 stainless steel. In this work, a plan of experiments based on Taguchi's L orthogonal array was established and milling experiments were 27 conducted with prefixed process parameters using tungsten carbide end mill. The machining parameters such as, cutting speed, feed rate and depth of cut were optimised with the objective of minimizing the surface roughness (Ra) and maximizing the Material Removal Rate (MRR). Finally an analysis of variance (ANOVA) was performed for finding the effects of each parameter on the surface roughness and the Material Removal Rate. It is being inferred that cutting speed has the main influence on the surface roughness and as it increases, the surface roughness also increases. The depth of cut has the most important influence on material removal rate and as it increases, the material removal rate also increases.
