Definition and design phase

The Definition and Design Phase involves decisions to confirm the suitability of the System Concept and to determine detailed functional requirements. It covers all aspects of designing the system and selecting a development environment including knowledge base creation, migration to delivery environments, and user interfaces. 

The objectives of the Definition and Design Phase must be met in order to assure a smooth Development Stage. These objectives are listed below. 

Validation techniques are the methods used to determine that the expert system conforms to the functional requirements and can be used as intended. The validation techniques should be identified in the Definition and Design Phase. Issues such as the need for external experts, and types and location of test cases should be thought out. 

The last question is to determine if we could use such data for reliability prediction. Early in the process, for example, at the requirements definition and analysis phase, our knowledge of the attributes and characteristics of the software development process is limited coding personnel and coding languages are undetermined, the design approach may not be defined, etc. Hence, our reliabihty assessment will be uncertain. The more we move into the life cycle process, the more information becomes available, and hence our uncertainty bound reduces. Let us call M the model of the process, that is, the set of characteristics that define the process. The characteristics of such model may include... 

For example a process flow scheme for crude oil stabilisation might contain details of equipment, lines, valves, controls and mass and heat balance information where appropriate. This would be the typical level of detail used in the project definition and preliminary design phase described in Section 12.0. 

Definitions Gas absorption is a unit operation in which soluble components of a gas mixture are dissolved in a liquid. The inverse operation, called stripping or desorption, is employed when it is desired to transfer volatile components from a liquid mixture into a gas. Both absorption and stripping, in common with distillation (Sec. 13), make use oF special equipment for bringing gas and liquid phases into intimate contact. This section is concerned with the design of gas-liquid contacting equipment, as well as with the design of absorption and stripping processes. 

Principles of thermodynamics find applications in all branches of engineering and the sciences. Besides that, thermodynamics may present methods and generalized correlations for the estimation of physical and chemical properties when there are no experimental data available. Such estimations are often necessary in the simulation and design of various processes. This chapter briefly covers some of the basic definitions, principles of thermodynamics, entropy production, the Gibbs equation, phase equilibria, equations of state, and thermodynamic potentials. 

Once the Project Definition stage is completed and accepted by DTI, the project moves into design and implementation phases. 

The design of a library that is project dependent and identical for both solution and solid phases, involves the identification of a suitable structural motif together with its randomization points, which are available for generation of diversity (Fig. 8.6, top) and the overall definition of library size. A retrosynthetic study follows in which a reasonable synthetic route in solution is determined, while work on SP requires the choice of a suitable support and of a linker as well (Fig. 8.6, bottom). 

In making all operating and design decisions. It Is Important to keep in mind the definition of the true reaction zone. Fundamentally, this Is the Interfaclal area between the immiscible hydrocarbon and acid catalyst liquid phases in the reactor. Reactants and products flow across this boundary. The olefins In the feed stream react Instantaneously with the sulfuric acid catalyst and combine with the relatively small amount of isobutane present In solution In the acid catalyst to form alkylate. Alkylate passes out through the Interfaclal surface reaction boundary into the hydrocarbon phase while Isobutane passes in to resaturate the catalyst. To suppress undesirable polymerization and other reactions It Is necessary to ... 

Geospatial Information System (GIS) with pre-loaded demographic and standardized data definitions for all frequently used sources of government information is a powerful tool for disaster research and nurses are ideally situated to use the tool because of their close relationship with communities. It may be impractical for a researcher from outside the local community to populate a GIS in advance since disasters do not follow a predictable pattern. However, a populated GIS that is utilized for community-based public health research could be designed during the prevention and preparedness phases of disaster planning. 

Apparatus and Procedure. It was necessary to design more definitive tests to further evaluate the better candidate surfactants. This was accomplished by means of a multi-phase dynamic-fiow test that consists of a small packed bed through which surfactant solution can be passed followed by gas to produce in situ foam. The pressure drop through the column is measured as the fiuid is drawn through the column at a constant volumetric fiow rate. From the recorded data, relative mobilities of the liquid and gas phases may be calculated. The change in gas mobility due to the presence of the surfactant is very closely related to the effectiveness of that surfactant for mobility control in oil core studies. A schematic drawing of the apparatus is shown in Figure 2. 

Conceptual estimates are typically prepared during the advanced R D and early process design stages. They are normally used to build the preliminary project economics, prepare preliminary execution plans, and develop cost estimates for the preparation of a complete process design (Phase 1) and a definitive cost estimate. The Phase 0 design package, described in Chapter 6, contains all the information required for conceptual estimates. See Table 9.1 for an example of a conceptual estimate. 

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