Scale of examination

In this example we are examining the composition uniformity of a whole roll of film this, then, becomes the scale for measuring the composition uniformity. We can, therefore, define a new concept the scale of examination, which is the scale or size of the overall sample we are analyzing for composition uniformity. 

At the lower limit of the scale of examination, at the level of ultimate particles, we also must characterize the local structure. When dealing with dispersion of carbon black particles on this scale of examination, for example, we shall determine whether the... 

When a specific mixture is considered, the assessment of the quality of that mixture depends on how closely it is examined. In the case of the pigment dispersion a microscopic examination of the mixture surface could well reveal a lack of colour homogeneity which was not visible to the naked eye. In the limit, if the mixture was examined on the scale of the individual particle then no mixing at all is possible and the mixture would always be unsatisfactory. There is evidently a critical scale of examination of a mixture at which it becomes unsatisfactory. 

It expresses the ratio of the measured variance to the variance of a completely segregated system. The intensity of segregation as defined in equation (5.10) reflects to some extent gross uniformity on a scale of examination reduced to the scale at which texture or local structure is being examined. 

Figure 5.3 Definition of the scale and intensity of segregation along with the scale of examination. (Reprinted from Ref. 4 with kind permission from John Wiley Sons. Inc., New York. USA.)...

An alternative approach is to determine the extent of the presence of agglomerates by extrusion filtration. There are two techniques based on extrusion of a fixed quantity of compound or masterbatch through a screen pack. This eliminates the very small scale of examination and human judgement involved in the microscopy tests, which may also view unrepresentative areas. Measurement is by one of two techniques ... 

At this point, one should not overlook the importance of the volume fraction of the minor component in commenting on the relative sizes of scales of examination and ultimate particles. To be more specific, suppose that we carry out a statistical evaluation of samples of 1% and 10% carbon black in PE and that we would like to have in our microscope eyepiece only about 30 carbon black particles. To meet that requirement we should increase our magnification in the 10% sample more than is required for the 1% sample due to its lower particle concentration. 

Is there an ideal scale of examination Besides the upper and lower limits mentioned previously, the texture of the mixture and its granularity pose another lower limit. Tadmor and Gogos (1979) define texture as nonunifonnity in the forms of patches, stripes, streaks, and so on. Thus, we can narrow the large range for the scale of examination by raising the lower limit to the scale of the granularity of the texture. 

The scale of examination for textures might differ from that for gross uniformity. However, the upper and lower limits, in both cases, remain the same. When the scale of examination is about the same as the scale of the ultimate... 

Moerner W E 1994 Examining nanoenvironments in solids on the scale of a single, isolated impurity molecule Science 265 46-53... 

Construct such a model for isotactic polypropylene. Estimate the volume of an isobutyl group on the scale of your model and examine whether interference between successive substituents would occur if this were the R group present. 

On a different note, after some 50 years of intensive research on high-pressure shock compression, there are still many outstanding problems that cannot be solved. For example, it is not possible to predict ab initio the time scales of the shock-transition process or the thermophysical and mechanical properties of condensed media under shock compression. For the most part, these properties must presently be evaluated experimentally for incorporation into semiempirical theories. To realize the potential of truly predictive capabilities, it will be necessary to develop first-principles theories that have robust predictive capability. This will require critical examination of the fundamental postulates and assumptions used to interpret shock-compression processes. For example, it is usually assumed that a steady state is achieved immediately after the shock-transition process. However, due to the fact that... 

The above measurements all rely on force and displacement data to evaluate adhesion and mechanical properties. As mentioned in the introduction, a very useful piece of information to have about a nanoscale contact would be its area (or radius). Since the scale of the contacts is below the optical limit, the techniques available are somewhat limited. Electrical resistance has been used in early contact studies on clean metal surfaces [62], but is limited to conducting interfaces. Recently, Enachescu et al. [63] used conductance measurements to examine adhesion in an ideally hard contact (diamond vs. tungsten carbide). In the limit of contact size below the electronic mean free path, but above that of quantized conductance, the contact area scales linearly with contact conductance. They used these measurements to demonstrate that friction was proportional to contact area, and the area vs. load data were best-fit to a DMT model. 

Subcontractor/supplier performance will be evident from audit reports, surveillance visit reports, and receipt inspections carried out by you or the third party if one has been employed. You need to examine these documents for evidence that the subcontractor s quality system is controlling the quality of the products and services supplied. You can determine the effectiveness of these controls by periodic review of the subcontractor s performance what some firms call vendor rating . By collecting data on the performance of subcontractors/suppliers over a long period you can measure their effectiveness and rate them on a scale from excellent to poor. In such cases you should measure at least three characteristics quality, delivery, and service. Quality would be measured by the ratio of defective conforming products received delivery would be measured by the number of days early or late and service would be measured by the responsiveness to actions requested by you on scale of excellent to poor. The output of these reviews should be in the form of updates to the list of assessed subcontractors/suppliers. 

In the case of a large-scale development it may be desirable to combine several environmental services for a full environmental impact assessment (ElA). This is the process of examining, in a comprehensive, detailed and systematic manner, the existing environment (natural, built and social) and the development that it is proposed to place within it. By integrating the two, an objective estimate can then be made of the likely effects of the development upon the environment, including benefits and negative impacts. Special techniques may be employed to help identify or quantify these impacts (e.g. the use of interaction matrices, overlays, screening tests, checklists, etc.). 

A good correlation with ordinary Hammett a values was based on 16 well-behaved substituents, and p-SOMe conformed well to this. Various other substituents showed deviations which were attributed to enhanced + R effects. These included p-SPh and this was explained in terms of 7t(pd) bonding, which was thus taken to play no part in the effect of p-SOMe on the methyl hyperfine splitting. More recently several 4-substituted benzyl radicals of the type RSO C6H4CH2 (n — 0,1 or 2 R = Me, Ph, Tol, COMe or OMe) have been examined by ESR spectroscopy249. The ability to delocalize spin density onto the substituent decreases in general as n increases and the effect of R depends on the oxidation state of sulfur. These authors have devised a new scale of substituent effects (sigma dot... 

An idea of the scale of turbulence can be obtained by measuring instantaneous values of velocities at two different points within the fluid and examining how the correlation coefficient for the two sets of values changes as the distance between the points is increased. 

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