Short and Long Term Performance

Product design starts by one visualizing a certain material, makes approximate 

The application of appropriate data to product design can mean the difference between the success and failure of manufactured products made from any material (plastic, steel, etc.). There are different sources of information on plastics. There is the data sheet compiled by a manufacturer of the material and derived from tests conducted in accordance with standardized specifications. Another source is the description of outstanding characteristics of each plastic, along with the listing of typical applications. 

It is important for the designer to become familiar with all the information that is available for each plastic, especially that which is pertinent to the product design requirements. Designers, who are knowledgeable of the data derived from metal tests, could have a tendency to apply the plastic data sheet information in a manner similar to that used for metals. This could be understood because there is no warning that some of the data supplied by the manufacturer are applicable only when use and test conditions are nearly the same. 

However, if suppliers data were to be applied without a complete analysis of the test data for each property, the result could prove costly and embarrassing. The nature of plastic materials is such that an oversight of even a small detail in its properties or the method by which they were derived could result in problems and product failure. 

Once it is recognized that there are certain reservations with some of the properties 

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The stability of membranes against thermomechanical and chemical stresses is an important factor in determining both their short- and long-term performance. Transport and mechanical properties of membranes affect the fuel cell performance, while the lifetime of a fuel cell is mostly dependent on the thermomechanical and chemical stability of the membrane. Thermomechanical and chemical degradation of a membrane will result in a loss of conductivity, as well as mixing of anode and cathode reactant gases. 

A continuous extrusion process that introduces molecular orientation to an unplasticised PVC pipe is described. Pipe design is discussed and it is shown how the relevant property improvements are utilised. Materials costs are reduced while short and long term performance is enhanced offering an outstanding opportunity for PVC pressure piping. 

Tables 3-1 through 3-22 and Figs. 3-1 through 3-30 compare the physical and mechanical property data of 25 engineering GRTP s as well as the effects of glass reinforcements. The data represent both short- and long-term performance.

Maintaining the effectiveness of the cover system for an extended period of time is another important performance criterion for ET covers as well as conventional covers. Short- and long-term... 

Polyimides are high-performance technical polymers mainly used for their short- and long-term thermal stability. 

While the various strategies described above have proven promising, SOFC electrodes remain largely empirically understood and far from optimized and suffer from numerous short- and long-term degradation problems. Reported performances vary tremendously with many unknown variables at work and limited understanding as to how materials properties and microstructure relate to performance and long-term stability. ... 

The total normalized mass loss was then determined by summing the mass losses over all the previous time increments. These tests were performed so that both short and long term data could be obtained with the same sample of glass. 

Additional return to shareholders can only be achieved by changing market expectations of the company s short and long term economic performance... 

To provide sufficient examples such that readers gain an understanding of how performance metrics can be successfully applied over the short and long term and... 

To monitor the accuracy and precision of the analytical process, two levels of controls should be performed every day when patient samples are analyzed. One control should reflect the concentration of sweat chloride concentration in a non-CF patient and the other control should reflect the concentration of sweat chloride found in a CF patient. The controls should be performed in parallel with patient samples and the results should fall within a predetermined range before patient results can be reported. Both short- and long-term quality control should be monitored. 

In addition to specified validation criteria, it is also useful during method development to assess column durability and column-to-column performance. Benchmarks have been established in a series of papers by Kele and Guiochon for short- and long-term repeatabilities and column-to-column... 

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