Process controls INDEX

Operations Research. 26. Decision Making. 27. Process Control. Index. 

Dow Fire and Explosion Index. The Dow Eire and Explosion Index (3) is a procedure usehil for determining the relative degree of hazard related to flammable and explosive materials. This Index form works essentially the same way as an income tax form. Penalties are provided for inventory, extended temperatures and pressures, reactivity, etc, and credits are appHed for fire protection systems, process control (qv), and material isolation. The complete procedure is capable of estimating a doUar amount for the maximum probable property damage and the business intermptionloss based on an empirical correlation provided with the Index. 

The next step is to apply a number of loss control credit factors such as process control (emergency power, cooling, explosion control, emergency shutdown, computer control, inert gas, operating procedures, reactive chemical reviews), material isolation (remote control valves, blowdown, drainage, interlocks) and fire protection (leak detection, buried tanks, fire water supply, sprinkler systems, water curtains, foam, cable protection). The credit factors are combined and appHed to the fire and explosion index value to result in a net index. 

Metrics for this might include number of excursions from statistical process control, but one very useful metric for controllability is process capability, or more accurately, process capability indices. Process capability compares the output of an in-control process to the specification limits by using capability indices. The comparison is made by forming the ratio of the spread between the process specifications (the specification width ) to the spread of the process values. In a six-sigma environment, this is measured by six standard deviation units for the process (the process width ). A process under control is one where almost all the measurements fall inside the specification limits. The general formula for process capability index is ... 

Controlled expansion alloys, 13 520-522 Controlled flavor release systems, 11 528, 543-553, 554-555 characteristics of, ll 544t demand for, 11 555 developments in, 11 558 elements of, 11 555-557 extrusion encapsulation for, 11 550 key aspects of, 11 556t morphologies of, 11 545 Controlled free-radical polymerization, block copolymers, 7 646 Controlled humidity drying, ceramics processing, 5 655-656 Controlled indexing, 18 241 Controlled initiation, 14 268-269 Controlled laboratory studies, in... 

In practical applications, a common objective is to have a capability index of 2.0 while a value greater than 1.5 is considered to be acceptable. If the Cpi value is too low, it can be improved by making a change that either reduces process variability or causes 5c to move closer to the target. These improvements can be achieved in a number of ways that include better process control, better process maintenance, reduced variability in raw materials, improved operator training, and process changes. 

A common parameter used by quality professionals to gauge whether or not the manufacturing process and analytical methodology is within the desired state of statistical process control (SPC) is a process capability index [11], such as the Cpk value. The Cpk value is the value of the tolerance specified for the given performance characteristic divided by the actual process capability. 

Fig. 5.7. Stability analysis of a process control loop for the reactive magnetron sputtering of high-index metal oxides. The control of discharge power to stabilize the oxygen partial pressure set point is modeled within the framework of the Berg model. A cycle time of 100 ms and process uncertainties for discharge current and oxygen partial pressure measurements are assumed, (from [71])...

Essentially all catalyst manufacturers have taken steps in recent years to train laboratory and manufacturing personnel in the application of SPC, and to make modifications to the manufacturing facilities to improve Cpk, the process capability index (6). Data collection and analysis on control charts are usually first steps for implementing SPC. 

Hazardous area requirements, if any Index of Protection (IP rating) for cleaning Accessibility Calibration requirements Maintainability and spares Outstation locations and network requirements. These should be capable of overseeing the whole network with response times suitable for the process controlled. The presentation of data that takes account of the number of users on the system and the various levels of technical information required. 

Generation of chloramines requires the same equipment as chlorination (gaseous or aqueous hypochloramination), plus equipment for adding ammonia (gaseous or aqueous). The information for calculating the corrosion indexes for final corrosion control and for determining the CT values for secondary chloramination process control can be found in Appendix A and Appendixes D-E, respectively. 

The refractive index (ASTM D-1218, ASTM D-1747) is the ratio of the velocity of light in air to its velocity in the substance under examination. It is used, together with density and viscosity measurements, in calculating the paraffin-naphthene ratio in mineral oils. Because refractive index is a measure of aromaticity and unsaturation on a given stock, manufacturers also use it as a means of process control. 

The term controlled index means that the refractive index can be made smaller than that of the bulk precursor by controlling the microstructure via the porosity. When silica is deposited, for example, the film index n can be varied over a wide range (7) from n = 1.1 to 1.5. This process control makes sol-gel coatings interesting for many optical, electronic, and sensor applications, but the evolution of the microstructure during film formation is not well understood, in spite of efforts to survey the variables (8, 9). This chapter reviews the important factors determining the microstructure of dip-coated films and explores at length two of them, evaporation and surface tension. 

Kourti, T. Process analytical technology and multivariate statistical process control. Wellness index of process and product— part 1. Process Analytical Technology, 1 (1), 13-19, 2004. 

The temperature points, with their index numbers, will be found on the process control diagrsim. These require thermowell installations in the piping. The temperature index numbers assign to each point are designated by conventional symbols such as TI, (Temperature Indicator), TH, TIC, TC, TRC, TR, TIA, TRCA, TT and TW followed by the number assigned to each of the points. 

Prokopenko, A., D. F. Williams, P. Kavel E. Karabanov, 1993. The organic indexes in the surface sediments of Lake Baikal water system and the processes controlling their variation. IPPCCE Newslett. 7 49-55. 

Melt index (MI) or melt flow rates is dependent on the MWD. With MWD differences of incoming material the fabricated performances can be altered requiring resetting process controls (Table 3.34). The more the difference, the more dramatic changes that can occur in the products. MI tests are used to detect degradation in products. MI has a reciprocal relationship to melt viscosity. This relationship of MW to MFR is an inverse one as one drops, the other increases or visa-versa. 

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