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

A comparative study in microstructural and tribological aspects of phosphorus enriched electroless Ni-P and Ni-P-Cu coating

Optimization of the wear performance of electroless Ni-P coating is carried out with the help of Taguchi orthogonal array design. Tribological testing parameters (applied load, sliding speed and duration of testing) are optimized with the help of L27 array in order to get the best wear performance from the coating. Load and time were found to be the most significant factors. Interaction between load and time is also found to hold some amount of significance towards the system response (wear). The characterization of the coating is carried out through scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffraction analysis. The coating morphology is found to resemble a nodular structure and the coating is mainly amorphous in as deposited state. However, post heat treatment at 400oC for one hour the coating transforms into crystalline structure. The wear mechanism is also studied and found to be a mixture of abrasive and adhesive wear phenomena. Wear Performance Optimization for Electroless Ni-P Coating

Wear Performance Optimization for Electroless Ni-P Coating

The present investigation is an experimental approach to deposit electroless Ni‐P‐W coating on mild steel substrate and find out the optimum combination of various tribological performances on the basis of minimum friction and wear, using weighted principal component analysis (WPCA). In this study three main tribological parameters are chosen viz. load (A), speed (B) and time(C). The responses are coefficient of friction and wear depth. Here Weighted Principal Component Analysis (WPCA) method is adopted to convert the multi‐responses into single performance index called multiple performance index (MPI) and Taguchi L27 orthogonal array is used to design the experiment and to find the optimum combination of tribological parameters for minimum coefficient of friction and wear depth. ANOVA is performed to find the significance of the each tribological process parameters and their interactions. The EDX analysis, SEM and XRD are performed to study the composition and structural aspects. © 2012 Published by Faculty of Engineering Corresponding author: Prasanta Sahoo Department of Mechanical Engineering, Jadavpur University, Kolkata‐700032, India E‐mail: psjume@gmail.com

Tribological Performance Optimization of Electroless Ni-P-W Coating Using Weighted Principal Component Analysis

Electroless Ni–P based composite coatings are more popular due to their excellent hardness, yield strength, wear resistance, frictional resistance, corrosion resistance, and good lubricity. The present study deals with significance of various coating process parameters on the corrosion behavior of the Ni–P–Al2O3 composite coatings on mild steel substrate. Corrosion behavior of the composite coatings after heat treatment at various annealing temperatures (300 °C, 400 °C, and 500 °C) are investigated by potentiodynamic polarization test using 3.5% NaCl solution. For maximization of corrosion resistance, the electrochemical parameters, corrosion potential ( Ecorr ) and corrosion current density ( Icorr ), are optimized using Taguchi based grey relational analysis. For optimization four coating process parameters are considered, namely, concentration of nickel source, concentration of reducing agent, concentration of second phase particles (alumina particles), and annealing temperature, as main design factors. The optimum combinations of the said design factors are obtained from the analysis. Analysis of variance (ANOVA) reveals that the concentration of alumina particles and annealing temperature has the significant influence on the corrosion resistance of the composite coatings. The microstructure of the surface is studied by scanning electron microscopy (SEM) and chemical composition is studied by energy dispersive X–ray analysis (EDX). The X–ray diffraction analysis (XRD) is used to identify the phase transformation behavior of the composite coatings.

Prasanta Sahoo

Papers

A comparative study in microstructural and tribological aspects of phosphorus enriched electroless Ni-P and Ni-P-Cu coating

Wear Performance Optimization for Electroless Ni-P Coating

Tribological Performance Optimization of Electroless Ni-P-W Coating Using Weighted Principal Component Analysis

Improvement of Corrosion Resistance of Ni-P-Al2O3 Composite Coating by Optimizing Process Parameters Using Potentiodynamic Polarization Test

A Study of Elastic-plastic Contact of Rough Surfaces Using N-point Asperity Model