Performance Reliability

Transfer of material between phases is important in most separation processes in which two phases are involved. When one phase is pure, mass transfer in the pure phase is not involved. For example, when a pure liqmd is being evaporated into a gas, only the gas-phase mass transfer need be calculated. Occasionally, mass transfer in one of the two phases may be neglec ted even though pure components are not involved. This will be the case when the resistance to mass transfer is much larger in one phase than in the other. Understanding the nature and magnitudes of these resistances is one of the keys to performing reliable mass transfer. In this section, mass transfer between gas and liquid phases will be discussed. The principles are easily applied to the other phases. 

Although operating in a dry, hot, and dusty desert environment, eompressor and expansion turbines must perform reliably if the Chuqui mine is to remain eompetitive in eopper and molybdenum produetion. 

The film that is selected for the application mainly controls the properties these products deliver to the customer. However, in the case of optical applications where transmission of the light is needed, the choice of pressure sensitive adhesive and the quality of the application to the substrate become very critical. Even for the non-optical uses, the PSAs have to perform reliably under sometimes very demanding circumstances. 

Example An airflow model that has been validated at air velocities up to 10 m/s (Mach number below 0.05) cannot be expected to perform reliably at a Mach number of 0.5. 

A failure modes and effects analysis is a systematic analytical technique for identifying potential failures in a design or a process, assessing the probability of occurrence and likely effect, and determining the measures needed to eliminate, contain, or control the effects. Action taken on the basis of an FMEA will improve safety, performance, reliability, maintainability and reduce costs. The outputs are essential to balanced and effective quality plans for both development and production as it will help focus the controls upon those products, processes, and characteristics that are at risk. It is not the intention here to give a full appreciation of the FMEA technique and readers are advised to consult other texts. 

Risk study (CPQRA or PRA) Specific study performed on a particular facility to determine the areas of weakness and strength in equipment and plant performance reliability may include consequence analysis and usually implies some judgment of the risk. 

Figure 6-33 diagrams vacuum system arrangements for process systems. It is important to examine the plant economics for each system plus the performance reliability for maintaining the desired vacuum for process control. 

Counterclockwise from top (1) Extruded fins offer high performance, reliability, and economy. (2) Hy-Fin extruded-serrated fins represent the state-of-the-art in fin tube construction technology. (3) Imbedded fins are recommended for applications involving high process temperatures. (4) L-base wrap-on fins offer low initial cost for applications involving low process temperatures. 

The only other variables that affect performance are the inlet-discharge valves, which control flow into and out of each cylinder. Although reciprocating compressors can use a variety of valve designs, it is crucial that the valves perform reliably. If they are damaged and fail to operate at the proper time or do not seal properly, overall compressor performance will be substantially reduced. 

End user Intuitive and correct behavior, helps do tasks, performance, reliability... 

Nonfunctional requirements Performance, reliability, scalability, and reuse goals... 

On the other hand, the prediction by content approach is applicable regardless of the variety of sorting pathways. It may be applied to partial sequences, which are now massively produced day by day. In addition, this approach allows a simple and unified treatment, which is convenient for objective testing (e.g., cross validation). However, there is no guarantee that the amino acid composition of proteins in each localization site is well conserved. Even when a clear tendency is observed for a known set of proteins, it can be an artifact resulting from the deviation of data because the size of known proteins for each site is often insufficient to perform reliable statistical analyses. It is also evident that this approach cannot handle the differences among isoforms with different localization (see Section III,K,3). 

SAE Standards Fomm SAE Vehicle Standards - in the early stages of developing standards for safety, performance, reliability and recyclability. Also establish testing procedures. 

SAE has established a Fuel Cells Standard Forum that is chartered with the establishment of standards and test procedures for fuel cell powered vehicles. The committee was established in 1999. The standards will cover the safety, performance, reliability and recyclability of fuel cell systems in vehicles with emphasis on efficiency and environmental impact. The standards will also establish test procedures for uniformity in test results for the vehicle/systems/components performance, and define interface requirements of the systems to the vehicle. Task Groups have been formed in the areas of safety, performance, reliability, emissions, recyclability, interface and miscellaneous. 

Although it is difficult to determine the quantitative requirements of plate and plate materials appropriately for various fuel cells and different applications in a development phase, such a target would be helpful to direct the development effort and make necessary trade-offs. The cascaded performance requirement targets in 2010 and 2015 for bipolar plates of fuel cells in transportation applications were set by the U.S. DoE (Department of Energy) according to functions of the plate mentioned before and overall requirements of performance, reliability, manufacturability, and cost of a stack, as shown in Table 5.1 [7]. The technical target in the DoE s multiyear research, development, and demonstration plan has been popularly and worldwide... 

The purpose of these requirements is to assure that the plate or plate materials have the required performance, reliability, and low cost. Among them, the first item is related to thermal management of the fuel cells. The second and third items are important for component compatibility in unit cells. As mentioned in previous chapters, the membrane and catalyst are particularly... 

The relationship between performance reliability and adhesive formulation is not simple. The key step in improving the reliability of adhesives on cathodically protected substrates is fully understanding the cathodic delamination process. Various mechanisms have been proposed in the literature. A large number of investigators have focused attention on the damage hydroxide ion does to coating adhesion. 

Section 8 outlines the following criteria for selection of measurement devices measurement span, performance, reliability, materials of construction, prior use, potential for releasing process materials to the environment, electrical classification, physical access, invasive or noninvasive, and life-cycle cost. 

Like all models, there are underlying assumptions. The main ones for analytical method validation include the areas of equipment qualification and the integrity of the calibration model chosen. If the raw analytical data are produced by equipment that has not been calibrated or not shown to perform reliably under the conditions of use, measurement integrity may be severely compromised. Equally, if the calibration model and its associated calculation methods chosen do not adequately describe the data generated then it is inappropriate to use it. These two areas are considered in some detail in Chapter 8. 

Design evaluation of performance, reliability, durability, maintainability, and safety under expected operational and storage conditions is carried out. 

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