I deliberated on `ethics' in the last issue of The IUP Journal of Mechanical Engineering and highlighted the steps involved in monitoring publishing ethics and the role of authors, editors and readers in it. I am looking forward to hearing from the readers in this regard (rkm.rkm@gmail.com; ijmecheng@iupindia.in).

In scientific publishing, there are two aspects of `ethics'. One, the publishing ethics—concerns and issues were raised in the focus of last issue; and two, the scientific ethics. The scientific ethics applies to the researchers who in their quest for knowledge do experiments and generate data. The scientific ethics, therefore, includes `ethics of experimentation', `ethics of data storage', etc. The scientific ethics is the concern of many international and national regularity bodies like governmental institutions, NGOs and Ethics Committees set up by universities or research organizations. Like in publishing ethics, the researcher, for short-term gains, get tempted to falsify experimental results with manipulated or fabricated data. I invite readers to share their experiences or views on scientific ethics.

Aluminum alloys are common as sliding bearing material. The recent research on the alternate sliding bearing materials unequivocally points to the beneficial role of Lead in Aluminum. But, these alloys offer a manufacturing challenge due to wide immiscibility gap. For such applications, apart from homogeneous microstructure, porosity control is also equally important, as it influences the tribiological performance through spreading of Lead in Aluminum matrix. These objectives can be achieved by mechanical alloying through attrition milling. In order to control the shape of the final powder metallurgical parts, appropriate models are necessary for densification of composite powders to simulate cold compaction responses. Ch. V S H S R Sastry and G Ranga Janardhana, in their paper, "Densification Behavior Modeling for Al-Pb Alloys Produced by Mechanical Alloying Through Attrition Milling", have studied the effect of alloy composition and the ball to charge ratio on the densification behavior of attrition milled Al-Pb alloys, with a view to developing nonlinear regression models that can best describe the densification behavior of attrition milled Al-Pb alloys from compressibility test data. Their study concludes that Richard's model effectively predicts densification behavior of attrition milled Al-Pb alloys. This approach is found to be quite helpful in deciding the compaction pressure for the required level of densification through processing of Al-Pb alloys of various compositions, where there are a number of variants influencing densification behavior, and no significant historical data exists for use in processing them.

In their paper, "Dynamic Balancing of a CNC Machine Spindle Using Vibration Signature: A Case Study of Turning Center on Condition Monitoring", V Hariharan and P S S Srinivasan have carried out vibration analysis and dynamic balancing of CNC turning center with the help of vibration signatures for reducing the spindle vibrations to a minimum possible level. Three levels of balancing have been considered, and from the frequency spectrum, it is observed that diagnosis of dynamic balancing will reduce the rejection of the components being manufactured.

The paper, "Enhancing Thermal Efficiency of Solar Pond with Planar Reflector", by S C Sharma and A Tiwari, shows that the energy limitations of solar ponds can be overcome by the use of planar reflectors. Reflectors can reflect the solar radiation and increase the radiation input to the solar pond. As a result, the pond not only supplies more heat energy but also saves on land cost to provide the same amount of energy. The enhancement of the average radiation gain in a solar pond using planar reflector has been studied and calculated for Indore city in India. The results were then compared with the performance of the pond without reflectors. It is found that the use of reflector having area only 5% of the total area of the pond can increase the radiation gain by more than 10%. An increase of 5% in the efficiency of the pond has been observed for bottom temperatures 70 °C and 80 °C, whereas for bottom temperature 60 °C, the increase in the efficiency is of the order of 1.25% when the reflector area is 5% of the pond area. The results also reveal that a maximum of 85% increase in the radiation energy gain can be achieved in the yearly value with bottom temperature of 80 °C. And a maximum of 227% increase in the radiation energy gain can be achieved in the yearly minimum value of solar radiation gain with bottom temperature of 80 °C.

Over the centuries, so many fastening techniques have been developed and are in use. Each technique has its own pros and cons. With the evolution of composite science and technology, many applications have come into the picture. One of them, one is the joining of similar and dissimilar metals using Glass Fiber Reinforced Polymer (GFRP). The paper, "Fabrication and Tensile Testing of GFRP Joints", by D Suneel, D Nageswara Rao and T V D B N Kartheek, deals with joining and tensile testing of similar metals using GFRP and comparing the results with arc welded joints of the same configuration. Finally, the FRP joint is also subjected to leak detection test.

The paper, "Prediction of Optimal Stability States in Inward-Turning Operation Using Genetic Algorithms" by K Rama Kotaiah and J Srinivas, proposes a neural network-based optimization scheme for predicting localized stable cutting states in inward-turning operation. A set of cutting experiments are performed in inward orthogonal turning operation. The cutting forces and critical chatter locations are predicted as a function of operating variables including tool overhang length. A neural network model is employed to develop the generalized relations. The optimum cutting parameters are predicted from the model with the help of binary-coded Genetic Algorithms (GA). The results are illustrated with the data of four different work materials. In this paper, a multivariate model of orthogonal turning operation has been presented. Using the experimental data for different workpiece materials, the cutting dynamics has been modeled with the radial basis function neural network. Optimum operating variables have been estimated for the minimum value of total cutting force. The corresponding chatter lengths have also been reported. It is found that compared to speed, the feed, depth of cut and overhang of the tool have a profound influence on the cutting forces and critical chatter locations.

Improving efficiency of thermal systems has been a challenge for long, and the use of Gas/Steam combined cycle employing inlet air cooling, fuel heating and closed loop cooling are some possibilities. Authors J P Yadav and Onkar Singh, in their paper, "Thermodynamic Study of Gas/Steam Combined Cycle Employing Inlet Air Cooling, Fuel Heating and Closed Loop Cooling in Topping Cycle", have used a combined cycle arrangement employing compressor inlet air cooling and fuel heating prior to injection in the combustion chamber for thermodynamic analysis. The variation in inlet air temperature at the inlet of the compressor and fuel preheating using a part of steam generated in Heat Recovery Steam Generator (HRSG) is considered. Closed loop-cooling technique is used for maintaining the gas turbine blade temperature within metallurgical limits. From the study of gas/steam combined cycle having steam generation at three different pressures with inlet air cooling, fuel heating and variation of steam pressure generation, it is found that cycle specific work output is maximum at 15 °C inlet air temperature and cycle efficiency is maximum at 25 °C inlet air temperature with or without fuel heating option.

- - R K Mittal
Consulting Editor