Engineering perspective

Once the candidate corrective measure alternatives have been identified, a more detailed evaluation of each alternative needs to be undertaken. From an engineering perspective, the first step in the evaluation process would include the development of a conceptual design for each alternative. The conceptual design would consist of a process description, a process flow diagram and a layout drawing. Preliminary sizing of equipment and utility and land requirements would be developed. In addition, chemical requirements and residuals produced can be estimated. From the conceptual design, permitability and residuals disposal issues can be identified and addressed. 

From a reliability engineering perspective, error can be defined by analogy with hardware reliability as "The likelihood that the human fails to provide a required system function when called upon to provide that fimction, within a required time period" (Meister, 1966). This definition does not contain any references to why the error occurred, but instead focuses on the consequences of the error for the system (loss or unavailability of a required function). The disadvantage of such a definition is that it fails to consider the wide range of other actions that the human might make, which may have other safety implications for the system, as well as not achieving the required function. 

There are a number of attempts to provide quantitative answers in the htera-ture, but these are generally flawed from either a cost engineering or chemical engineering perspective and their results should be treated with extreme caution. This caveat notwithstanding, it is probably reasonable to say that for most products the threshold hes in the range of 1000—10 000 tonne per year process stream (not product) rate. The threshold value will not, however, be the same for aU products, processes, operating sites, and so on. 

From an engineering perspective, recycled materials should be used in such a manner that the expected performance of the product will not be compromised. Waste and byproduct materials, however, differ vastly in their types and properties and, as a result, in the end-use applications for which they may be suited. Experience and knowledge regarding the use of these materials vary from material to material as well as from facility to facility. To recover these materials for potential use, engineers, researchers, generators, and regulators need to be aware of the properties of the materials, how they can be used, and what limitations may be associated with their use. 

O Brien Gere Engineerings, The engineering perspective, in Hazardous Waste Site Remediation, Bellandi, R., Ed., Van Nostrand Reinhold, New York, 1988, p. 422. 

Leib, T.M., Pereira, C.J. and Villadsen, J. (2001) Bioreactors a chemical engineering perspective. Chemical... 

Langer R (2007) Editorial Tissue engineering - perspectives, challenges, and future directions. Tissue Eng 13 1-2. 

Forming operations are described from both a chemical and ceramic engineering perspective, with emphasis on design of structures with desired mass transfer and strength characteristics. Specific forming methods that are discussed include extrusion, bead forming and spray-drying. Newer forms will also be introduced. 

From an engineering perspective, deep-fat frying can be defined as a unit operation where heat and mass transport phenomena occur simultaneously. Convective heat is transferred from the frying media to the surface of the product, which is thereafter conducted within the food. Mass transfer is characterized by the loss of water from the food as water vapor and the movement of oil into the food (Singh, 1995). 

Diffusion - In this text, we will dehne diffusion (and most other processes) from an engineering perspective, in that we will go to the level of detail that suits our objective. Diffusion can then be defined as the mixing of chemicals by random molecular motion. Diffusion coefficients in dilute solutions will be discussed in detail in Chapter 3. 

Much recent research (7-5) has been devoted to converting methane to products that are more easily transported and more valuable. Such more valuable products include higher hydrocarbons and the partial oxidation products of methane which are formed by either direct routes such as oxidative coupling reactions or indirect methods via synthesis gas as an intermediate. The topic of syngas formation by oxidation of CH4 has been considered primarily from an engineering perspective (7-5). Most fundamental studies of the direct oxidation of CH4 have dealt with the CH4 + O2 reaction system in excess O2 and at lower temperatures (6-10). 

The chapter is organized as follows. First, to establish a common language, we define some common terms from both a pharmaceutical and an engineering perspective. Subsequently, we review model-based design and optimization as a framework for product and process development and optimization, process scale-up, and continuous improvement activities. The role of process and analytical technology (PAT) methods and principles in this framework is discussed. Finally, the main areas requiring effort are identified. 

The term in-process testing is synonymous with process control. From an engineering perspective tests at the end of a process do not provide any direct means to keep a process under control. It is well recognized that such tests simply accept or reject lots and depending on the operating characteristic curve of a test accepted lots are no better than the rejected ones (14). 

Richardson, J. T., Principles of Catalyst Development, Plenum Press, New York, 1989. (Undergraduate level. An introduction to catalysis and catalyst development from an engineering perspective. The emphasis throughout is on the practical aspect of the subject, rather than on theory.)... 

From a green engineering perspective, the number and types of unit operations can also be counted ... 

Although appealing from an engineering perspective, the analyses based on linear thermoelasticity do not address the action of defects and dislocations created by microscopic yield phenomena below the CRSS and of those that are incorporated in the crystal at the solidification front. In the previous works cited (104-108), the authors assume that no defects exist at the melt-crystal interface and that the stresses on this surface are zero. Constitutive equations incorporating models for plastic deformation in the crystal due to dislocation motion have been proposed by several authors (109-111) and have been used to describe dislocation motion in the initial stages of... 

Evans, L., The Evolution of Computing in Chemical Engineering Perspectives and Future Directions. CACHE Trustees 40th Anniversary Meeting, Boulder, Colorado August 8 (2009). 

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