Materials, design techniques

Non-complex and/or non-critical applications in mechanical design can also make use of probabilistic design techniques and justify a more in-depth approach if the benefits are related to practitioners and customers alike. Surveys have indicated that many products in the industrial sector have in the past been overdesigned (Kalpakjian, 1995). That is, they were either too bulky, were made of materials too high in quality, or were made with unwarranted precision for the intended use. Overdesign may result from uncertainties in design calculations or the concern of the designer and manufacturer over product safety in order to avoid user injury or... 

Electrical insulation is continually being improved. The motor manufacturers make use of this and other technological developments to put more power into smaller, lighter, more efficient packages. Modem insulating materials can withstand heat, moisture, and corrosive atmospheres, and new metals can withstand more mechanical punishment. Computer design techniques are also helpful. 

Because of the magnitude of the task of preparing the material for this new edition in proper detail, it has been necessary to omit several important topics that were covered in the previous edition. Topics such as corrosion and metallurgy, cost estimating, and economics are now left to the more specialized works of several fine authors. The topic of static electricity, however, is treated in the chapter on process safety, and the topic of mechanical drivers, which includes electric motors, is covered in a separate chapter because many specific items of process equipment require some type of electrical or mechanical driver. Even though some topics cannot be covered here, the author hopes that the designer will find design techniques adaptable to 75 percent to 85-1- percent of required applications and problems. 

All of the chapters have been carefully reviewed and older (not necessarily obsolete) material removed and replaced by newer design techniques. It is important to appreciate that not all of the material has been replaced because much of the so-called older material is still the best there is today. 

Modem methods for the manuf and storage of expl materials, which include many exotic chemicals, fuels, and propints, allow less space for a given quantity of expl material than previously permitted. Such concns of expls increase the possibility of the propagation of accidental explosions (one accidental explosion causing the detonation of other expl materials). It was evident that a requirement for more accurate design techniques had become essential. Ref 3 describes a rational design method to provide the required structural protection. It presents methods of design for protective construction... 

STANDARD REFERENCE MATERIAL PROTEINEMBEDDING TECHNIQUE AND DESIGN OF... 

In conclusion, it is evident that most of the degradation issues in diffusion layers are related to the hydrophobic properties of the materials. Therefore, techniques that investigate the different degradation and corrosion modes that may affect the diffusion layers inside fuel cells are vital in order to design and choose optimal diffusion layers with the goal of achieving the best reliability and performance possible. 

Another design technique being actively explored involves searching for patterns. Whereas the method described in the previous section attempts to imderstand the behavior of atoms and molecules, this method takes its cue from combinations of these particles. By means of X-ray crystallography and other methods, scientists have already determined the structures of thousands of crystals, composed from a wide variety of elements and compoimds. The set of these structures represents an enormous amoimt of data. Some researchers have begun to use computers to sift through this data, looking for clues as to what elements and compoimds produce which structures. With these clues, prediction of the properties of new materials may be possible. 

Utilize your knowledge of the structure and properties of materials engineering and of materials processing techniques to carry out a materials selection design problem. 

The characterization of the flow in existing DPF materials has been assessed by experiments and macroscopic continuum flow in porous media approaches. However, when it comes to material design it is essential to employ flow simulation techniques in geometrically realistic representations of DPF porous media. Some first applications were introduced in Konstandopoulos (2003) and Muntean et al. (2003) and this line of research is especially important for the development of new filter materials, the optimization of catalyst deposition inside the porous wall and for the design of gradient-functional filter microstructures where multiple functionalities in terms of particle separation and catalyst distribution (for combined gas and particle emission control) can be exploited. 

---