During rough sea conditions, ships undergo extreme rolling which hinders deployment/retrieval operation. It also leads to seasickness for the scientists and crew onboard. Stabilizers and fluid-filled Anti-Roll Tanks (ART) are quite effective in suppressing the risk. In the paper, “Seakeeping Analysis of an Indian Research Vessel”, by D Rajasekhar, U S Ramesh, G V V Pavankumar, Ananthakrishna, P S Deepaksankar, D Narendrakumar, K Ramsundaram and N Ravi, evaluation of a vessel has been carried out to improve its seakeeping qualities. A multidisciplinary research vessel ‘Sagar Manjusha’ is considered for seakeeping analysis and the parameters studied include relative velocity, acceleration, propeller emergence, slamming and motion sickness incidence, etc. The experimental study included the development and installation of ART having U-tube configuration. The roll experimental analysis of the tank and ship resulted in the transformation of an innovative idea into a successful model so that similar problems in ships can be solved. Seakeeping analysis and installation of ART resulted in considerable improvement in the safety and comfort of vessel, machineries and instruments used for scientific research, and the quality of life and the productivity of the scientists and crew onboard.

Energy management is an important factor in all fields of engineering, especially in making compact and efficient electronic components. This leads to the development of Pulsating Heat Pipes (PHPs)—based on a concept proposed by Akachi. PHP is basically a capillary tube filled with two-phase of fluid inside it and seems to meet all the present-day cooling requirements. PHPs differ by their geometry and the mechanism of fluid transport inside the heat pipe. The various parameters which affect the performance of Closed Loop Pulsating Heat Pipes (CLPHP) directly or indirectly are design/geometrical parameters, operating parameters and properties of working fluids. In the paper, “Experimental Investigation of Thermal Performance Characteristics of Different Fluids in a Closed Loop Pulsating Heat Pipe”, the authors, Sahil Gupta and Parinam Anuradha, have studied the performance of CLPHP with three different fluids—methanol, acetone and ethyl acetate—by varying the input parameters such as heating power and evaporator temperature. The study observed that acetone exhibits the best performance among the three fluids in heat transfer performance due to least value of dynamic viscosity and that acetone and ethyl acetate show less start-up period due to higher value of surface tension.

Normally, different additives are added separately to the quenching media to improve the mechanical properties. However, cow urine, which contains many elements mixed homogeneously, when mixed with base quenching media improves the microstructure and mechanical properties marginally. In the paper, “Enhancement of Microstructure and Mechanical Properties of Al-Alloy Materials Using Biological Quenching Medium”, the authors, M Maruthi Rao and N V V S Sudheer, have studied the effect of cow urine as an additive in the base quenching media, on the microstructure of cast Al-alloy and its mechanical properties for use in the manufacture of piston heads. The study observed that the use of cow urine and water in equal proportions at a temperature of about 450 oC and quenching time of 90 min improves the performance of pistons considerably. Further, it is noticed that the cow urine mix contributes to an overall improvement in the microstructure and the mechanical properties of Al alloy.

Surface roughness measures the finer irregularities of the surface texture and influences the performance of mechanical parts. It is considered to be one of the most important requirements in machining process. During manufacturing operation, the machining parameters, tool and workpiece material properties and cutting conditions are the main factors that influence surface roughness. Various researchers have studied the effect of cutting conditions like cutting speed, feed rate and depth of cut on surface roughness. In the paper, “Optimization of Process Parameters for CNC Turning Using Response Surface Methodology”, the authors, Nitish Kumar, Ashwani Kumar Dhingra and Pankaj Kumar, have carried out an investigation to optimize the process parameters in CNC turning of AISI 15b25 alloy steel using Response Surface Methodology (RSM) coupled with ANOVA. The authors have suggested that optimal values of surface roughness (2.29 µa) and material removal rate (1327.93 mm3/min) can be achieved at a rotational speed of 2513 RPM, feed rate of 0.15 mm/min and depth of cut of 0.5 mm.

In modern-day manufacturing and service industries, Computerised Maintenance Management Systems (CMMS) are preferred to conventional—paper-based—preventive maintenance systems to effectively manage and control plant/equipment maintenance. CMMS packages can produce status reports and documents giving details or summaries of maintenance activities. The more sophisticated the package is, the more analysis facilities are available. Further, such package requires fast and precise insights into data for informed decision making. In the paper, “A Proposed Framework for Computerized Maintenance Management System for a Power Plant”, the authors, Soumava Mandal and P C Tewari, have developed an application software using Visual Studio.NET as the front end user interface and SQL as the back end database. This CMMS aims at lowering the effective downtime, frequency of failures and overall maintenance cost to improve maintenance policies and machine life, and can lead to efficient planning and control of the maintenance aspects.
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S V Srirama Rao
Consulting Editor