Historical experience generally

Probably the first major publication of a process model for the autoclave curing process is one by Springer and Loos [14]. Their model is still the basis, in structure if not in detail, for many autoclave cure models. There is little information about results obtained by the use of this model only instructions on how to use it for trial and error cure cycle development. Lee [16], however, used a very similar model, modified to run on a personal computer, to do a parametric study on variables affecting the autoclave cure. A cure model developed by Pursley was used by Kays in parametric studies for thick graphite epoxy laminates [18]. Quantitative data on the reduction in cure cycle time obtained by Kays was not available, but he did achieve about a 25 percent reduction in cycle time for thick laminates based on historical experience. A model developed by Dave et al. [17] was used to do parametric studies and develop general rules for the prevention of voids in composites. Although the value of this sort of information is difficult to assess, especially without production trials, there is a potential impact on rejection rates. 

In the next section, we first briefly review the historical experience of highly crosslinked UHMWPE for hip replacement and summarize the general characteristics of contemporary materials in current clinical use. The next section also describes the effect of thermal treatment on the properties of fhis family of materials. In the final part of this section, we summarize the latest short-term clinical results using highly crosslinked and thermally treated UHMWPE. For more detailed information about specific highly crosslinked formulafions, see Chapter 15. 

In general, historic experiments were performed primarily to explore characteristics and behaviors of tsunamis. On the other hand, a majority of recent experiments aims at providing adequate benchmark data sets for validation of muneric models. For example, benchmarking exercises for numeric models were conducted at the 1995 Friday Harbor Workshop and the 2004 Catalina Island Workshop Objectives of laboratory experiments have evolved together with advances in measuring instruments. 

Written standards represent the attempt to standardize the historical experience of individuals accumulated over time. Some standards reflect scientific theories about gas behavior, combustion, or rock mechanics. Standards like 30 CFR 75(301-5), for example, specify the maximum concentrations of explosive gases that can accumulate in a section. Other standards specify general procedures like air sampling without citing specific techniques or codes of practice [30 CFR 75(301-6)]. Some standards specify testing meth-t)ds developed by scientific testing institutes like American Society for Testing and Materials (ASTM) [30 CFR 75(302-3)]. And some specify the sequence of procedures that must occur in pre-shift examinations and inspections [30 CFR 75(303)]. 

Though unimolecular fall-off curves are important historically, their general insensitivity to intramolecular dynamics suggests that other types of experiments are more useful for detecting intrinsic non-RRKM behavior. Such an experiment is the one by Reddy and Berry on allyl isocyanide isomerization ... 

Proposed flux models for porous media invariably contain adjustable parameters whose values must be determined from suitably designed flow or diffusion measurements, and further measurements may be made to test the relative success of different models. This may involve extensive programs of experimentation, and the planning and interpretation of such work forms the topic of Chapter 10, However, there is in addition a relatively small number of experiments of historic importance which establish certain general features of flow and diffusion in porous media. These provide criteria which must be satisfied by any proposed flux model and are therefore of central importance in Che subject. They may be grouped into three classes. 

Several generalizations can be made about aerosol characterization study design based on past experience. Existing data should be used to obtain an understanding of the area under study. These data include historical aerosol and gas concentrations, meteorological data, emissions inventories, chemical and microscopical analyses, and the results of dispersion modeling. 

From a general historical perspective we can characterize Paracelsus and iatrochemistry as a kind of counter-culture of the sixteenth century, a revolt against the rigidity of the University curriculum and its isolation from experience. Similar movements can be found in religion, politics, the arts, and economics, the whole period being characterized by changes and upheaval that we call the Renaissance. 

While I have characterised state-averse as an historical feature of Southeast Asia (minus Vietnam and the Irrawaddy basin), there was a wide variety of experiences with states both of the cosmic templebuilding and the trade-oriented type. At one end of the spectrum were the hill peoples in general, along with boat people or sea-gypsies of small-island clusters, and the inhabitants of some other small islands of... 

Historical data from production facilities often give rise to highly confounded results. Consider a process in which temperature and pressure are considered to be inputs, and yield is an output. If the data are based on observations rather than experiments, why might temperature and pressure be confounded [See, for example, Box, G.E.P. (1954). The Exploration and Exploitation of Response Surfaces Some General Considerations and Examples , Biometrics, 10, 16.]... 

Historically, two periods occurred for the determination of the number of hydrate water molecules per guest molecule. In the first century (1778-1900) after the discovery of hydrates, the hydration number was determined directly. That is, the amounts of hydrated water and guest molecules were each measured via various methods. The encountered experimental difficulties stemmed from two facts (1) the water phase could not be completely converted to hydrate without some occlusion and (2) the reproducible measurement of the inclusion of guest molecules was hindered by hydrate metastability. As a result, the hydrate numbers differed widely for each substance, with a general reduction in the ratio of water molecules per guest molecule as the methods became refined with time. After an extensive review of experiments of the period, Villard (1895) proposed Villard s Rule to summarize the work of that first century of hydrate research ... 

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