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

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Applied Numerical Analysis. By C.F. Gerald. Pp. xii, 340. £3·60. 1970. (Addison-Wesley.)

Waste Printed Circuit Boards recycling: an extensive assessment of current status

Weight reduction of vehicle is very important because vehicle weight directly affects energy consumption. Studies researching lightweight vehicle manufacturing process that use polymers are reviewed in this paper. Approaches reducing the weights of vehicles using polymers most frequently involve replacing ferrous and non-ferrous metals with polymers and increasing the specific strengths and rigidities of polymers. Researches into polymers for use in lightweight vehicle are classified into high performance polymers, polymers for weight reduction, reinforced polymer composites, polymer sandwich panels, and polymer/metal hybrid systems. A diverse range of polymer materials can be used to make vehicle components and the manufacturing methods required to produce and work those materials vary greatly. Shaping processes must be chosen according to the materials being used and the product design. Replacement of metal products with polymer materials in current vehicles is limited. Large amounts of lightweight materials, such as polymers, will be greatly used to construct newly developed vehicles, including electric and electric/hybrid vehicles.

Research trends in polymer materials for use in lightweight vehicles

In this paper the study of recycling technology for production of refuse derived fuel (RDF) is described. Various types of wastes (wood, carton, paper, plastic and textile) were pro- cessed by two-shaft and single-shaft shredders to obtain the output product (1-2 mm), which is suitable for briquetting process. For samples manufacturing the briquetting equipment developed at Slovak University of Technology in Bratislava was used. Technological test showed that by briquetting of the municipal waste higher pressing temperature and compacting pressure should be applied. For quality evaluation of the manufactured briquettes the density and strength properties were determined. The mechanical strength of briquettes from RDF increased after mixing it with wood and paper wastes. The influence of different parameters (fraction size, moisture content, compacting pressure and temperature) to briquette quality was studied. To determine the calorific value of the briquetting stock the tests in the chemical laboratory of the Department of Thermal Engineering of TUT were performed.

Determination of physical, mechanical and burning characteristics of polymeric waste material briquettes

The purpose of this study was to design a light-weight sandwich panel for trailers. Strength calculations and selection of different materials were carried out in order to find a new solution for this specific application. The sandwich materials were fabricated using vacuum infusion technology. The different types of sandwich composite panels were tested in 4-point bending conditions according to ASTM C393/C393M. Virtual testing was performed by use of ANSYS software to simplify the core material selection process and to design the layers. 2D Finite element analysis (FEA) of 4-point bending was made with ANSYS APDL (Classic) software. Data for the FEA was obtained from the tensile tests of glass fiber plastic (GFRP) laminates. Virtual 2D results were compared with real 4-point bending tests. 3D FEA was applied to virtually test the selected sandwich structure in real working conditions. Based on FEA results the Pareto optimality concept has been applied and optimal solutions determined.

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Design and Testing of Sandwich Structures with Different Core Materials

The goal of the study was to find a cost-effective composition of a particle reinforced composite that is light in weight but has sufficient mechanical properties. The matrix of the particulate composite is unsaturated polyester resin that is reinforced with alumina trihydrate particles. Part of the alumina trihydrate proportion was replaced with hollow glass microspheres to reduce weight and save costs. In order to find out the influence of the light filler on the physical and mechanical properties of composites, materials with different percentages of the light filler were prepared. Test specimens were cut from moulded sheets that were fabricated with vacuum assisted extruder. Tensile strength, indentation hardness measured with a Barcol impressor, and density were determined. Based on the experimental data a multi-criteria optimization problem was formulated and solved to find the optimal design of the material. Artificial neural networks and a hybrid genetic algorithm were used. The optimal solution is given as a Pareto curve to represent the distinction between the density and selected mechanical properties of the composite material. The composite material filled with 6% hollow glass microspheres showed 3% loss in the tensile strength and 26% loss in the surface hardness compared to the composition without the filler. The weight decreased by 13% compared with the initial composition. The addition of hollow glass microspheres did not lower the net value of the material, it increased 7%.

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Influence of hollow glass microspheres on the mechanical and physical properties and cost of particle reinforced polymer composites

This research concentrates on the effect of moisture absorption and UV radiation on the mechanical and physical properties of wood-plastic composites (WPC). The goal is also to evaluate the importance of wood flour fraction size on the mechanical properties of WPC and their influence on the accelerated weathering results. Wood flour reinforced composites with three different fractions of wood flour made from birch (Betula) chips were prepared. Additionally, Bleached-Chemi-Thermo- Mechanical aspen (Populus tremula) pulp (Aspen BCTMP) was used. Thermoplastics (LLDPE-g-MAH, PP) were used to prepare composites. Wood flour and BCTMP surface were treated with two different coupling agents: 3-aminopropyltriethoxysilane (APTES) and polyvinyalcohol (PVA). The WPC specimens were prepared by injection molding. Accelerated weathering tests were carried out to evaluate the influence of weathering on the mechanical and physical properties of composites. Three-point bending test and Charpy impact test were used to test mechanical properties. The test results showed that using wood flour as a filler material in composites made the WPC material more rigid and brittle. Due to the water absorption and swelling of WPC, the flexural modulus (MOE) and strength decreased and impact strength increased by making the material weaker with increasing the deflection of the WPC. The UV radiation decreased the composites flexural strength and MOE, while impact strength was increased. After the accelerated weathering cycles, cracks and voids were found on the surface of the WPC materials. After the UV radiation treatment, also the WPC colour was lightened.

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The influence of accelerated weathering on the mechanical and physical properties of wood-plastic composites

This study examines the effect of different post cure parameters to a polymer matrix particulate reinforced composite material. The goal is to evaluate the importance of different factors and to suggest a well-balanced post cure mode that supports the application of the material. Polymer matrix composites are post cured at elevated temperature to increase the amount of cross linking to achieve better chemical and heat resistance and mechanical properties. Every material has an individual post cure process that depends from the raw materials. Post curing variables include temperature, duration of cure, the time between initial curing and post curing and temperature profile gradient. There are several ways to determine the cure state of a polymer. It can be evaluated based on the mechanical and physical properties, residual styrene content, glass transition temperature, residual exotherm or solvent swelling test. For the determination of the suitable post cure parameters test slabs were casted and post cured with varying time and temperature. Glass transition temperature, residual exotherm, softening in ethanol, surface hardness, flexural strength and flexural modulus were determined. It is shown that the material should be cured at 60 °C – 80 °C. With higher temperature and extended time of cure the glass transition temperature raises but the material becomes too brittle. DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2435

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Jaan Kers

Papers

Determination of physical, mechanical and burning characteristics of polymeric waste material briquettes

Design and Testing of Sandwich Structures with Different Core Materials

Influence of hollow glass microspheres on the mechanical and physical properties and cost of particle reinforced polymer composites

The influence of accelerated weathering on the mechanical and physical properties of wood-plastic composites

Preliminary Study of the Influence of Post Curing Parameters to the Particle Reinforced Composite's Mechanical and Physical Properties