Impact performance criteria

The perception of students about the impact of mini-projects on their learning is carried out through a survey. The survey questions are designed to understand how students perceive their performance in meeting each of the performance criterion specified for the implementation of the project and they are ... 

Strains in the 80-90% region are found to cause some permanent buckling of the cell walls, but the majority of the deformation recovers with 24h. A criterion for the performance of the foam in protective helmets is proposed. With HDPE foam the performance can deteriorate by 30% in a single severe impact, but even so, this is better than the PS foam widely used. 8 refs. BXL PLASTICS LTD. COURTAULDS ADVANCED MATERIALS... 

First, the role of rubber modification in high rate impact is to suppress spallation by inducing the material to yield in the presence of dynamic tensile stresses arising from impact. Second, this yield-spall transition occurs at different strain rates for different rubber contents and may be predictable using quasistatic, low temperature tests of this type. These tests can also provide information concerning the basic nature of the yield process in these materials through the activation parameters which are obtained. Third, the Bauwens-Crowet equation seems to be a good model for the rate and temperature sensitive behavior of the American Cyanamid materials and is therefore a likely candidate for a yield criterion to use in the analytical code work on these materials which we hope to perform as a continuation of this work. 

Last but not the least, criterion for good performance of a catalyst system is its crush strength. A refinery catalyst unit is liable to encounter upsets during its run length. A quality that a refiner looks for in the catalyst is its ability to sustain such upsets without any adverse impact on its performance. 

If part of the protective architecture requires an active response from occupants, such as evacuation or seeking shelter, then the response time can be an important criterion. The paucity of data on response times does not allow realistic estimates to be made. The overall performance metric analyses need to ensure that response times are estimated cautiously and with full awareness of the impact of their variability on the overall performance. 

Impact measurement. The impact tests were conducted in the usual manner on single sheets with a Gardner Laboratory Impact Tester (Model IG-1120) with a 0.625" diameter punch hammer. At least ten drops were performed in the center 50% of the sheets and with points of impact at least 1" apart. The failure criterion was a brittle (not ductile or tear) break. The values reported in Table I are 50% probabilities (energy at which 50% of failures are brittle). The standard deviation of the values is about 10%. 

The most important criterion is capability. Can the CRO provide the needed services Are the CRO s personnel well qualified and do they have experience in the therapeutic area If the CRO is not capable of performing the study, it will likely fail to meet the sponsor s expectations. A disastrous outcome could harm the careers of sponsor staff, delay product development, and have a negative impact on the sponsor s economic well-being. 

In addition, the taking into account of a single phase of the lifecycle or a single environmental criterion can lead to an incorrect choice if the performances of the chosen material are mediocre in relation to other criteria. This raises the question of determining an exchange valne between the different enviromnental impact criteria [ASH 04]. 

The residual settlement criterion is an important aspect that has a significant impact on the performance acceptance of a single pile test. Two conditions of assessment of the pile residual settlement are considered at present, namely ... 

At this point we have defined the superstructure of interest, developed three performance criteria for the optimization of the superstructure and provided some fundamental insight into the impact of design variables on the responsiveness criterion. In this section the approach to solve the multiobjective optimization problem is presented together with the reference design case to be compared with the optimized designs. 

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