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

Biocomposites reinforced with natural fibers: 2000–2010

This century has witnessed remarkable achievements in green technology in material science through the development of natural fiber reinforced composites. The development of high-performance engineering products made from natural resources is increasing worldwide day by day. There is increasing interest in materials demonstrating efficient use of renewable resources. Nowadays, more than ever, companies are faced with opportunities and choices in material innovations. Due to the challenges of petroleum-based products and the need to find renewable solutions, more and more companies are looking at natural fiber composite materials. The primary driving forces for new bio-composite materials are the cost of natural fibers (currently priced at one-third of the cost of glass fiber or less), weight reduction (these fibers are half the weight of glass fiber), recycling (natural fiber composites are easier to recycle) and the desire for green products. This Review provides an overview of natural fiber reinfocred composites focusing on natural fiber types and sources, processing methods, modification of fibers, matrices (petrochemical and renewable), and their mechanical performance. It also focuses on future research, recent developments and applications and concludes with key issues that need to be resolved. This article critically summarizes the essential findings of the mostly readily utilized reinforced natural fibers in polymeric composite materials and their performance from 2000 to 2013.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mame.201300008

Progress Report on Natural Fiber Reinforced Composites

Fibre-reinforced composites are rapidly gaining market share in structural applications, but further growth is limited by their lack of toughness. Fibre hybridisation is a promising strategy to toughen composite materials. By combining two or more fibre types, these hybrid composites offer a better balance in mechanical properties than non-hybrid composites. Predicting their mechanical properties is challenging due to the synergistic effects between both fibres. This review aims to explain basic mechanisms of these hybrid effects and describes the state-of-the-art models to predict them. An overview of the tensile, flexural, impact and fatigue properties of hybrid composites is presented to aid in optimal design of hybrid composites. Finally, some current trends in fibre hybridisation, such as pseudo-ductility, are described.

/pdf/fibre-hybridisation-in-polymer-composites-a-review-gcnp0ezsc7.pdf

Fibre hybridisation in polymer composites: a review

Studies on combined cooling and drying of agro products using air cooled internal heat recovered vapour absorption system

High friction force of NiP/SSP (Nickel-phosphorus/Sea shell particle) composite coating limits their use in low friction applications, hence to overcome this, nano ZnO is incorporated with different weight percentage. NiP with weight fraction (3.0 g/l) of (SSP) and various weight fractions (0.10 g/l, 0.25 g/l, 0.50 g/l, 0.75 g/l and 1.0 g/l) of nano ZnO particles were deposited on En8 steel using an alkaline electroless process. Friction – wear test was carried out on NiP/SSP/ZnO composite coatings and comparison was made with NiP and NiP/SSP composite coating using pin on disc apparatus. Wear track was characterized using SEM and non-contact surface profilometer. Hardness is measured using Vickers micro hardness tester. There is a decrease in the hardness of NiP/SSP/ZnO coating due to the incorporation of nano ZnO particles. Significant improvement in friction and wear resistance was observed for NiP/SSP/ZnO (0.25 g/l) coatings in contrast to NiP and NiP/SSP coating.

Impact of nano zinc oxide on the friction – Wear property of electroless nickel-phosphorus sea shell composite coatings

Extensive work has been carried out in the drillability study of thin laminated composites, which are utilized in the light engineering work. Heavy engineering works like construction of bridges, prefabricated platforms, and ballistic applications utilizes thick nonlaminated composites because of its enhanced mechanical properties. Since there is no sufficient literature on the drillability study of thick nonlaminated composites, an experimental investigation has been carried out to study the effect of process parameters on quality characteristics for standard and special geometry design of a drill body. The drilling experiments using carbide drills were conducted using response surface methodology. Special geometry (ratio) drill performs better than the standard geometry (twist) drill. The optimal process parameter levels for twist drill were determined as feed of 0.052 mm/rev and spindle speed of 1059 r/min and that for ratio drill as feed of 0.05 mm/rev and spindle speed of 750 r/min.

Effect of drill point geometry on quality characteristics and multiple performance optimization in drilling of nonlaminated composites

This article discusses the effects of process parameters (feed and spindle speed) on quality characteristics (thrust force, torque, surface roughness and ovality) for standard and special geometric design of a drill body in dry drilling of pultruded and sheet moulding compound thick composites. Pultruded (non-laminated) and sheet moulding compound (laminated) thick glass fibre–reinforced plastic composites with a higher percentage of fibre weight fraction are extensively used in construction of bridges, prefabricated platforms, ballistic applications, structural applications, instrument bases and automotive load floors, and therefore, prediction of better performance drill helps the fabrication industry in making good quality holes. The drilling experiments using coated tungsten carbide drills, twist drill (standard geometry) and ratio drill (special geometry) of diameter of 10 mm were conducted using response surface methodology. Analysis of variance of the experimental results reveals that for both twis...

A. Elayaperumal

Papers

Studies on combined cooling and drying of agro products using air cooled internal heat recovered vapour absorption system

Impact of nano zinc oxide on the friction – Wear property of electroless nickel-phosphorus sea shell composite coatings

Effect of drill point geometry on quality characteristics and multiple performance optimization in drilling of nonlaminated composites

Drillability study of pultruded and sheet moulding compound thick polymeric composites

Optimization of process parameter levels during drilling high fiber volume fraction nonlaminated gfrp polymeric composites