Causes of Imperfections

Just as imperfections can be found in the traffic safety behavior of individual travelers so can imperfections be found in the formulation and implementation of traffic safety policy. Vehicle technology has been emphasized at the expense of nontechnological safety measures. Safety of passenger car occupants has been emphasized at the expense of other travelers. Net benefits of crashworthiness standards such as mandatory passive restraints have been exaggerated because safety gains are overestimated and some costs are ignored. The Dole Rule on passive restraints only partly satisfies the five criteria for analytical acceptability. 

Another misconception was the belief that vehicle manufacturers pay any costs of the safety standards. Consumers, however, bear part and perhaps even most of the costs. The distribution of the added cost depends on the shift in demand due to the safety standards and the responsiveness (elasticity) of demand and supply to vehicle price. Ralph Nader observed that the gap between existing design and technolomcally attainable crashworthiness was wide and the attainable level was rising What he did not say is that if the new technology involves more than a trivial cost and substantial share is borne by the consumer, then additional safety involves difficult choices for consumers, manufacturers and regulators. All are concerned about consumer reaction to the additional costs which accompany the additional safety equipment. 

Unlimited public support for traffic safety at the expense of other goals is another misconception. Fragmentary evidence easts that  

Question I would like to ask you which three of these national problems you would like to see the government devote most of its attention to in the next year or two  

Resources for the Future survey. The number of cases is smaller than the total (N = 1,576) because the question was asked only of a subsample. 

---

For identical samples R =1, and R is lower when the samples are different. This coefficient can be used as a measure of similarity. The similarity results are further utilized to decide if the Py-MS results on two samples are different enough to indicate that the samples are different indeed or only the analytical fluctuations are the cause of imperfect similarity. A threshold of similarity (distance, or correlation) is commonly used for this decision. 

Distressing Stains. Interest and charm can be added to furniture by the dehberate infliction of imperfections. These imperfections may be caused by physical distress such as hammers, files, nails, chains, or rocks or caused by finish distress such as "dy specking" or staining to simulate past abuse, such as waterstains caused by the careless placement of a drinking glass. 

Chemical and physical nonlinearities are caused by interactions among the components of a system. They include such effects as peak shifting and broadening as a function of the concentration of one or more components in the sample. Instrumental nonlinearities are caused by imperfections and/or nonideal behavior in the instrument. For example, some detectors show a... 

Uniform microstractuie is cracial to the superior performance of advanced ceramics. In a cerantic material, atoms are held in place by strong chentical bonds that ate impervious to attack by corrosive materials or heat. At the same time, these bonds are not capable of much "give." When a ceramic material is subjected to mechanical stresses, these stresses concentrate at minute imperfections in the microstmcture, initiating a crack. The stresses at the top of the crack exceed the threshold for breaking the adjacent atomic bonds, and the crack propagates throughout the material causing a catastrophic brittle failure of the ceramic body. The rehability of a ceramic component is directly related to the number and type of imperfections in its microstmcture. 

The two interpretation problems involved are (A) calibration and (B) correction of imperfect resolution caused by axial dispersion. 

On the basis of advances of the chemistry of imperfect crystals [209] the role of point defects existing in the volume and on the surface of oxide adsorbents and their effect on electrophysical characteristic during adsorption-caused change is being elucidated [32]. 

Several injection-molded polycarbonate (PC) disks used in a consumer product (i.e., a clock face) were analyzed, because the disks contained defects. The defects were analyzed initially and imaged using a stereoscopic microscope fitted with a digital camera. The defects present on the samples were easily identified. It was noticed that the defects were located on different regions of the molded part. This important observation eliminated a systematic problem or an imperfection at a specific site on the mold surface as the cause of the defect. 

Figure 12 shows the stress-strain curves of IER at various temperatures. A strain-induced reinforcing effect is not observed at temperatures above -10 °C. This fact may be due to network inhomogeneities caused by imperfect crosslinking. 

These pressure tests should be seen in the context of the mechanical stresses and subsequent failures in the field. In spite of all precautions on installation it must be assumed that pipes will be damaged, backfill and trenches will differ from those specified, welds may be imperfect and there will be bending stresses. Poor installation practice has been the principal cause of service failures, particularly of PVC pipe, and when installed correctly pipes taken from service (now 40 years) show no evidence of deterioration. In addition, polymers have improved greatly since pipes were first manufactured. Marshall and co-workers [2] describe the situation in more detail and recommend an approach to testing based on fracture mechanics. 

A shadow-mask technique has been applied for the local metal deposition to exclude metal residues on other designs processed on the same wafer (Fig. 4.2b). Such metal residues may be caused by imperfections in the patterned resist due to topographical features on the processed CMOS wafers or dust particles. The metal film is only deposited in those areas on the wafer, where it is needed for electrode coverage on the microhotplates. This also renders the lift-off process easier since no closed metal film is formed on the wafer, so that the acetone has a large surface to attack the photoresist. Another advantage of the local metal lift-off process is its full compatibility with the fabrication sequence of chemical sensors based on other transducer principles [20]. 

Gray and Waddington [57,120] examined the physico-chemical properties of silver azide and state that its melting point is 300°C. On the basis of the latest opinion that the explosive decomposition of azides results from processes involving ions and electrons caused by imperfection and deficiencies in the crystal lattice (Jacobs and Tompkins [22]), the authors incorporated silver cyanide, Ag2(CN)2,... 

It is difficult to assess to what extent the imperfect fits obtained by the equivalent models are the result of partial miscibility. This is because the models do predict minor shifts in the loss maxima, which are in the same direction as the shifts expected from partial miscibility. Thus the major cause of the deviations may well be the inability of the models to describe a complex morphology with a single adjustable parameter. 

Dewetting driven by van der Waals forces has been observed in many instances [25]. It is characterized by a wave pattern, as opposed to heterogeneously nucleated film break-up caused by imperfections in the film, leading to the formation of isolated holes that cause the dewetting of the film [26, 27],... 

---