Cycle Tools

The inventory analysis is a technical process of collecting data, in order to quantify the inputs and outputs of the system. Energy and raw materials consumed, emissions to air, water, soil and solid waste produced by the system are calculated for the entire life cycle of the product or service. To make this analysis easier, the system under study is split into several subsystems and unit processes, and the data obtained are grouped in different categories in a LCI table. 

The impact assessment identifies and characterizes the potential effects produced in the environment by the system under study. The first step is classification, in which the environmental interventions (resources consumed, emissions to the environment) identified in the inventory analysis are grouped in different impact categories or indicators, according to the environmental effects they are expected to produce. For example, CO2 and CH4 emissions are classified in the category global warming potential (GWP). 

The third step is normalization, which involves the environmental profile ofthe system to a broader data set or situation, for example, relating the system s GWP to a country s yearly GWP. 

LCA is an holistic approach. All necessary inputs and emissions in many stages and operations of the life cycle are considered to be within the system boundaries. This includes not only inputs and emissions for production, distribution, use and disposal but also indirect inputs and emissions - such as from the initial production of the energy used - regardless of when or where they occur. 

The suitability of LCA as a tool for environmental evaluation of chemical products and processes has been suggested by several authors to be involved in the development and promotion of green/sustainable chemistry [44, 76-79]. The tool is well known by the chemical industry, which uses it for product and process development, marketing and communication with public authorities and clients, among other purposes. 

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National Pollution Prevention Center. Sustainable Product Systems Life Cycle Tools and Applications, URL http //www.umich.edu/ nppcpub/shortcourse97.html. 

The Direct Current Potential Drop method (DCPD) has been evaluated for non destructive testing of uniaxially produced Powder Metallurgical (P/M) parts. The aim is to adapt DCPD to be functional as an ndt tool during production of parts. Defects can occur at different stages in the production cycle which means that DCPD has to be performed on components in different states and searching for different defects. 

The resist must have suitable radiation sensitivity. Today s exposure tools are so costiy that tool throughput is a key measure of performance. The overall time to expose a resist film is the sum of the times to load and position the substrate in the exposure tool, to align the substrate and the mask, to irradiate the film, and to unload the complete part. In the optimum case the resist exhibits sufficient radiation sensitivity so that the fraction of the overall cycle apportioned to irradiate the film does not limit the number of substrates exposed in a given period of time. 

Life cycle cost analysis is the proper tool for evaluation of alternative systems (11,12). The total cost of a system, including energy cost, maintenance cost, interest, cash flow, equipment replacement and/or salvage value, taxes, inflation, and energy cost escalation, can be estimated over the useflE life of each alternative system. A Hst of life cycle cost items which may be considered for each system is presented in Tables 3 and 4. Reference 14 presents a cash flow analysis which also includes factors such as energy cost escalation. 

During the press operation, which is actually a form of compression mol ding, the resin-treated laminate pHes are heated under pressure and the resins cured. The initial heating phases cause the resin to melt and flow into voids in the reinforcing ply and bond the individual pHes together. The appHed heat simultaneously causes the resin to polymerize and eventually to cross-link or gel. Therefore, resin viscosity reaches a minimum during the press cycle. This is the point at which the curing process becomes dominant over the melt flow process. Dynamic mechanical and dielectric analyses (11) are excellent tools for study of this behavior. 

The majority of published °Pb reports address the utility of °Pb as a geochronological tool rather than as an element that is involved in complex biogeochemical cycles. Nonetheless, some of these studies do provide insight into the geochemical behavior of °Pb and °Po. Nearly all of the lead in the world s surface oceans is believed to be of anthropogenic origin—derived from combustion... 

The Toyota X300 fork lift truck project design cycle is concurrent in nature spanning all the major disciplines in the process with quality assurance reviews, stipulating the use of appropriate tools and techniques at certain points. The product development process produced by General Electric is called the Tollgate Process . Again, it is concurrent in nature and includes ten review points. 

When a single technique is employed only local life-cycle cost minimization is achieved. If the global life-cycle cost is to be minimized, a number of techniques have to be applied (Watson et al., 1996). In this case, tools and techniques shouldn t compete with each other, but be complementary in the product development process. The correct positioning of the various off-line tools and techniques in the product development process, therefore, becomes an important consideration in their effective usage. Patterns of application have been proposed by a number of workers over several years (Brown et al., 1989 Jakobsen, 1993 Norell, 1993) and the importance of concurrency has been highlighted as a critical factor in their use (Poolton and Barclay, 1996). 

Maintenance practices are being combined more and more with operational practices to ensure that plants have the highest reliability with maximum efficiency. This has led to the importance of performance condition monitoring as a major tool in the operation and maintenance of a plant. Life cycle costs, rightly so, now drive the entire purchasing cycle and thus the... 

Inspection. After the final adhesive cure cycle, the bonded assembly is removed from the tool and inspected. The first and most cursory inspection is a simple visual check. Major problems such as crushed core and significantly mis-located details can be seen with the unaided eye. A lack of continuous adhesive squeeze-out ( flash or spew ) around the periphery of details can be indicative of insufficient adhesive and subsequent voids. 

First part qualification. First part qualification is a process performed the first time a new bonded assembly is manufactured or the first time a new tool is used to manufacture a bonded assembly. First part qualification provides assurance that all of the aspects that control bond assembly quality, such as the design dimensions, detail part manufacturing techniques, tool dimensions, layup procedures and autoclave cure cycle parameters are correct and will produce a bond assembly that meets the engineering requirements. 

For a typical assembly, first part qualification begins with a rigorous dimensional check and painstaking prefit of all details on the bond tool. The assembly details are placed on the tool without adhesive, close contact between bond surfaces is verified and any detail or tool interference is corrected prior to proceeding. This is followed by fabrication of a verification film , or a simulated bond cure cycle of the assembly to allow measurement of the adhesive bondline thickness. 

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