Joint design improving

Figure J.l Common flat adhesive joint designs butt, plain lap, and single strap. (See Appendix K for joint design improvements on these.)...

Design improvements have played a major role in the development of corrosion resistant vehicles. Areas of entrapment, where salt, poultice and other materials could build up and provide a corrosive environment, have been eliminated to enhance corrosion resistance in vehicles. For example, wheel wells are now designed to have a sloping configuration so that corrosives can be washed or will drain out. Drain holes have been incorporated in areas so that corrosive liquid cannot accumulate. Sealers are used to eliminate crevices and joints where corrosives can build up. And, attempts have been made to reduce galvanic corrosion by avoiding dissimikkr metal contact. 

FIG. 27 Land-design improvements made for the FA controller card. To eliminate the crack as noted in the photomicrographs of the cross-sectioned solder joints and improve the mechanical strength, the land length for a QFP component (0.5-mm pitch, 208 I/O) was increased from 2.1 to 3.3 mm. (Courtesy of Panasonic.)... 

Biomaterials. Just as stem designs have evolved in an effort to develop an optimal combination of specifications, so have the types of metals and alloys employed in the constmction of total joint implants. Pure metals are usually too soft to be used in prosthesis. Therefore, alloys which exhibit improved characteristics of fatigue strength, tensile strength, ductihty, modulus of elasticity, hardness, resistance to corrosion, and biocompatibiUty are used. 

Singh, K. P. and K. K. Niyogi - editors, Heat Exchange Equipment and Valve Design and Operability Improvement, International Joint Power Generation Conference, Pheonix, AZ, 1994. 

Tubular reactors often offer the greatest potential for inventory reduction. They are usually simple, have no moving parts, and a minimum number of joints and connections that can leak. Mass transfer is often the rate-limiting step in gas-liquid reactions. Novel reactor designs that increase mass transfer can reduce reactor size and may also improve process yields. 

To achieve the goal of required performance, durability, and cost of plate materials, one approach is improvement of the control of the composition and microstructure of materials, particularly the composite, in the material designing and manufacturing process. For example, in the direction of development of thermoplastics-based composite plate, CEA (Le Ripault Center) and Atofina (Total Group) have jointly worked on an irmovative "microcomposite" material [33]. The small powders of the graphite platelet filler and the PVDF matrix were mixed homogeneously by the dispersion method. The filler and matrix had a certain ratio at the microlevel in the powder according to the optimized properties requirements. The microcomposite powders were thermocompressed into the composite plate. 

Combustion control is currently a hot area of research in the U.S. and abroad. In addition to basic research at a number of universities, joint industry-university S T efforts are also underway to implement the control strategies developed by researchers in industry applications. Though some of the demonstrations have been made using gaseous fuels, the techniques can be extended to liquid fuels as well, and efforts are underway to accomplish this. It is hoped that future engines will perform equally well in off-design conditions, with improved reliability and easier maintenance, and reduced operational costs. 

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