Requirements Analysis Process

Since these models can be designed, edited, run, and driven even over the limits, they can be extremely valuable sources for modeling in the digital domain, process analysis, requirements modeling, risk analysis, and even collecting statistical data and modehng breakdowns of complex systems. 

Environmental process analysis requires the characterization of chemical process and waste streams in order to evaluate their environmental abuse potential and treatability characteristics. An integral part of this analysis, as well as environmental fate determinations, is the isolation of organic compounds and metabolic products from very complex matrices such as waste water effluents, process streams, biological reactors, and fermentation broths. Generally, the organics involved are fairly polar, water-soluble compounds that must be ex-... 

Choosing a suitable Raman spectrometer for on-line process analysis requires different criteria from laboratory analysis. Some key considerations are laser safety, ruggedness, repeatability, long-term and environmental stability, high uptime, calibration ttansferability, ease of operation and maintenance, smart diagnostics for analyser performance, and industry-standard communication. Many processes require the analysis to be performed... 

Life-cycle analysis, in principle, allows an objective and complete view of the impact of processes and products on the environment. For a manufacturer, life-cycle analysis requires an acceptance of responsibility for the impact of manufacturing in total. This means not just the manufacturers operations and the disposal of waste created by those operations but also those of raw materials suppliers and product users. 

This is used extensively for qualitative analysis, for it is a rapid process and requires simple apparatus. The adsorbent is usually a layer, about 0 23 mni. thick, of silica gel or alumina, with an inactive binder, e.g. calcium sulphate, to increase the strength of the layer.. A. i i slurry of the absorbent and methanol is commonly coated on glass plates (5 20 cm. or 20 x 20 cm.), but microscope... 

The utilization of commercially available finite element packages in the simulation of routine operations in industrial polymer processing is well established. However, these packages cannot be usually used as general research tools. Thus flexible in-house -created programs are needed to carry out the analysis required in the investigation, design and development of novel equipment and operations. 

Eault tree analysis (ETA) is a widely used computer-aided tool for plant and process safety analysis (69). One of the primary strengths of the method is the systematic, logical development of the many contributing factors that might result ia an accident. This type of analysis requires that the analyst have a complete understanding of the system and plant operations and the various equipment failure modes. 

While the intelligent alarm approach is clearly preferable, substantial process analysis is required to support intelligent alarming. Meeting the following two objectives is quite challenging ... 

Fluoride analysis requires a previous separation process step, which is known as Willard-Winter distillation using a mixture of HClOyH PO, to isolate fluoride from interferences like Al, Cl, etc. 

A process engineer s task is often to evaluate the performance of a compressor unit based on gas throughputs and terminal pressures. Since compressor stations are complex machines and operations, the analysis required is sophisticated and goes well beyond simple computations on a personal computer, although some preliminary evaluations can certainly be made. In this section we summarize the working expressions for standard compressor operations. Compressor operations can be categorized under three thermodynamic categories ... 

The term design-analysis is used to emphasize the essential, but not dominant, role of analysis in the overall structural design process. Analysis plays no role whatsoever in dress design (with the possible exception of the now-classical analysis of a strapless evening gown). However, engineering design of a structure must involve analysis in the form of mechanistic relationships. Those mechanistic relationships must be used to quantitatively determine how to create the structural capabilities and then to match them to the structural requirements. The dis-... 

We could go through that same kind of problem analysis for many different structures, and, in the process, design requirements could be expressed for each of them. The most common (Jesign requirements would be expressed in some manner in terms of strength, stiffness, and life, but there are many other issues as well. Whether the material will corrode, for example. Whether it will provide the proper insulation or just the opposite, sufficient conductivity, and so on. There are many, many different types of tasks that we ask a structure to perform. 

The purpose of the Critical Task Identification and Screening analysis is to reduce the amoimt of analysis required by focusing on tasks that have a significant error potential. The screening process essentially asks the following questions ... 

The process of vibration analysis requires gathering complex machine data and deciphering it. As opposed to the simple theoretical vibration curves shown in Figures 43.1 and 43.2, the profile for a piece of equipment is extremely complex. This is tme because there are usually many sources of vibration. Each source generates its own curve, but these are essentially added together and displayed as a composite profile. These profiles can be displayed in two formats time-domain and frequency-domain. 

To demonstrate the use of such a comparative cost analysis, the production of a panel was analyzed according to different processes (Fig. 9-6). In these case studies the following conditions existed (1) the panels measured 61 x 91 cm (24 x 36 in.) with the wall thickness dictated by the process and part requirements so that the weights of the panels differed (2) production was at a level of 40,000/yr. (3) the plastics for all panels were of the same type, except that different grades had to be used, based on the process requirements, so that costs changed (4) each panel received one coat of paint, except that the structural foam also had a primer coating and (5) costs were allocated as needed to those processes that required trimming and other secondary operations. 

Such an analysis requires a clear understanding of the CVD process and a review of several fundamental considerations in the disciplines of thermodynamics, kinetics, and chemistry is in order. It is not the intent here to dwell in detail on these considerations but rather provide an overview which shouldbe generally adequate. More detailed investigations of the theoretical aspects of CVD are given in Refs. 1-3. 

The precision of time series predictions far into the future may be limited. Time series analysis requires a relatively large amount of data. Precautions are necessary if the time intervals are not approximately equal (9). However, when enough data can be collected, for example, by an automated process, then time series techniques offer several distinct advantages over more traditional statistical techniques. Time series techniques are flexible, predictive, and able to accommodate historical data. Time series models converge quickly and require few assumptions about the data. 

High speed analysis requirements which influence sample preparation demands (being the rate determining step of the analytical process). 

Measurement of the wavelength (or energy) of the characteristic X-rays emitted enables qualitative analysis to be carried out. The more difficult process of quantitative analysis requires a measurement of the number of X-ray photons of a given type that are emitted per second. 

Differential thermal analysis (DTA) consists of the monitoring of the differences in temperature existing between a solid sample and a reference as a function of temperature. Differences in temperature between the sample and reference are observed when a process takes place that requires a finite heat of reaction. Typical solid state changes of this type include phase transformations, structural conversions, decomposition reactions, and desolvation processes. These processes may require either the input or release of energy in the form of heat, which in turn translates into events that affect the temperature of the sample relative to a nonreactive reference. 

Time and cost requirements for a FTA depend on the complexity of the process being analyzed and the level of resolution. With an experienced team, modelling a single top event involving a simple process could require one day or less. Complex processes or large systems with many potential accident events could require many weeks or months, even with an experienced analysis team. Table 4.26 presents estimates of the time needed to perform a PrHA using the FTA method. 

Many of the conservation measures require detailed process analysis plus optimization. For example, the efficient firing of fuel (category 1) is extremely important in all applications. For any rate of fuel combustion, a theoretical quantity of air (for complete combustion to carbon dioxide and water vapor) exists under which the most efficient combustion occurs. Reduction of the amount of air available leads to incomplete combustion and a rapid decrease in efficiency. In addition, carbon particles may be formed that can lead to accelerated fouling of heater tube surfaces. To allow for small variations in fuel composition and flow rate and in the air flow rates that inevitably occur in industrial practice, it is usually desirable to aim for operation with a small amount of excess air, say 5 to 10 percent, above the theoretical amount for complete combustion. Too much excess air, however, leads to increased sensible heat losses through the stack gas. 

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