There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Intermolecular And Surface Forces

Nonlinear Oscillations: Exact Solutions and their Approximations

https://pureadmin.qub.ac.uk/ws/files/126683921/Edited_sudagar_R1.pdf

Electroless nickel, alloy, composite and nano coatings – A critical review

Effect of filler loading on mechanical properties of natural carbon black reinforced polymer composites

This paper presents an experimental study of material removal rate (MRR) and roughness characteristics in electrical discharge machining (EDM) of EN 31 tool steel. Experiments are carried out by utilising the combination of four process parameters viz. pulse on time, pulse off time, discharge current and voltage based on L27 Taguchi orthogonal array. Multi-response optimisation of EDM process parameters is done with respect to MRR and five different surface roughness characteristics based on Taguchi method coupled with grey relational analysis. Analysis of variance (ANOVA) is performed and it is observed that current is the significant process parameter that affects the responses. Optimal setting has been verified through confirmation test and the result shows a good agreement with the predicted value. This indicates utility of the grey-Taguchi technique as a multi-objective optimiser in the field of EDM. Also, the surface morphology is studied with the help of scanning electron microscopy.

Optimisation of EDM process parameters using grey-Taguchi technique

This paper undertakes a geometric nonlinear large displacement static analysis of crossbeam structure. A crossbeam structure comprises two beams in contact with their longitudinal axes perpendicular to each other, used effectively in civil and mechanical engineering, marine and aerospace structures. The energy method forms the basis for the mathematical formulation and the governing set of equations are obtained using the principle of extremisation of the total energy of the system in its equilibrium state. To obtain the solution, an iterative procedure is developed based on the reaction force generated between the two beams of the system. The method is validated by experiment and simulation through ANSYS v11. Results are presented in terms of plots of reaction force and the displacement of the interaction point versus load in dimensional form and additionally, the deflected shapes of the crossbeam structure at static equilibrium condition, under a particular load, are provided. The static response of the system has been studied for variation of beam thickness, loading pattern and position of the supporting beam.

/pdf/large-displacement-of-crossbeam-structure-through-energy-5gmtt46ble.pdf

Large Displacement of Crossbeam Structure through Energy Method

Electroless Ni-B (ENB) alloy coatings are extensively used due to their good tribological, physical, electrical and mechanical properties. The behaviour of coatings generally depends on the concentration of bath parameters, heat-treatment temperature, as well as heat-treatment duration. The current study was carried out to deposit coatings over steel specimens with various NaBH4 concentrations and heat-treated at various temperatures to study the significance of NaBH4 concentration as well as heat-treatment temperature on corrosion resistance of the Ni-B coatings. Ni-B coatings were heat-treated for an hour at different temperatures for example, 350°C, 450°C and 550°C. Electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization (PDP) test methods were employed to analyse the corrosion behaviour of the as-deposited as well as heat-treated coatings. The tests were conducted against a corrosive environment consisting of 3.5% NaCl solution. It was observed that the as-deposited coatings with low boron content exhibit a mixture of amorphous and nanocrystalline structures. The same gradually becomes amorphous with the rise in sodium borohydride concentration. The increase in boron content with sodium borohydride concentration in the coating bath led to the transformation of phase structure. This amorphous phase structure of as-deposited coatings further transforms into a crystalline structure upon heat treatment. This crystallinity increases with heat-treatment temperature. The as-deposited coatings show cauliflower-like surface morphology at all concentrations of NaBH4 but the same becomes a coarse-grained structure with clustered aggregates leading to a rough surface. The as-deposited coatings show better corrosion resistance behaviour compared to heat-treated ones, especially at the higher temperature.

Effect of heat-treatment temperature and borohydride concentration on corrosion behaviour of ENB coating

The present study considers finite element based co nta t analysis of an elastic-plastic axisymmetric hemisphere using ANSYS to study the ef fect o material properties under full stick contact condition. Results are compared with previo us elastic-plastic models for perfect slip and full stick contact conditions. It is found that materials with modulus of elasticity to yield strength (E/Y) ratio less than and greater than 300 show strikingly different contact behavior. When E/Y ratio is less than 300, contact load incre ases with the increase in modulus of elasticity whereas in elastic-plastic range, contac t load decreases with the increase in yield strength.

Prasanta Sahoo

Papers

Effect of filler loading on mechanical properties of natural carbon black reinforced polymer composites

Optimisation of EDM process parameters using grey-Taguchi technique

Large Displacement of Crossbeam Structure through Energy Method

Effect of heat-treatment temperature and borohydride concentration on corrosion behaviour of ENB coating

Elastic-plastic Contact of a Deformable Sphere Against a Rigid Flat for Varying Material Properties Under Full Stick Contact Condition