Capability variability

The method is considered to be a qualitative and useful tool for rapid sample screening. Limitations of the method center on its moderate reproducibility, detection limits, and resolving capabilities. Variability between operators can be as high as 30%. Detection limits (without any concentration of the sample extract)... 

Noncnzymc-Catalyzcd Reactions The variable-time method has also been used to determine the concentration of nonenzymatic catalysts. Because a trace amount of catalyst can substantially enhance a reaction s rate, a kinetic determination of a catalyst s concentration is capable of providing an excellent detection limit. One of the most commonly used reactions is the reduction of H2O2 by reducing agents, such as thiosulfate, iodide, and hydroquinone. These reactions are catalyzed by trace levels of selected metal ions. Eor example the reduction of H2O2 by U... 

Initially, at least, methanol vehicles should be capable of operating on either M85, gasoline, or any mixture of the two. These vehicles are caHed flexible fueled (EEV) or variable fueled vehicles (VEV). It is expected that methanol could be sold in existing service stations out of tanks constmcted of methanol-tolerant material such as carbon steel or certain fiber glass formulations. EventuaHy, if enough EEV/VEVs are sold and methanol becomes widely avaHable, dedicated vehicles would likely be buHt and sold. Methanol has been used for years as a racing fuel. 

The proper methods for measuring fabric thickness are described in ASTM D1777. Because fabric thickness is dependent on the appHed pressure, any measurement of thickness should also report the pressure at which the measurement was made. Thus, an apparatus capable of applying variable pressure to the sample while determining thickness would be desirable. Many instmments, however, allow only incremental increases in pressure, depending on the weight used. Regardless of the instmment used, it is always necessary to state the pressure under which the thickness was deterrnined. 

The general criterion of chemical reaction equiUbria is the same as that for phase equiUbria, namely that the total Gibbs energy of a closed system be a minimum at constant, uniform T and P (eq. 212). If the T and P of a siagle-phase, chemically reactive system are constant, then the quantities capable of change are the mole numbers, n. The iadependentiy variable quantities are just the r reaction coordinates, and thus the equiUbrium state is characterized by the rnecessary derivative conditions (and subject to the material balance constraints of equation 235) where j = 1,11,.. ., r ... 

Coupling digital controls with networking technology permits information to be passed from level-to-level within a corporation at high rates of speed. This technology is capable of presenting the measured variable brom a flow transmitter installed in a plant in a remote location anywhere in the world to the company headquarters in less than a second. 

The large variety of displacement-type flmd-transport devices makes it difficult to list characteristics common to each. However, for most types it is correct to state that (1) they are adaptable to high-pressure operation, (2) the flow rate through the pump is variable (auxiliary damping systems may be employed to reduce the magnitude of pressure pulsation and flow variation), (3) mechanical considerations limit maximum throughputs, and (4) the devices are capable of efficient performance at extremely low-volume throughput rates. 

Typical pilot-plant top-suspended baskets are 305 mm (12 in) diameter by 127 mm (5 in) deep. Commercial machines are available in sizes from 508-mm (20-in) diameter by 305-mm (l2-in) depth to 1524-mm (60-in) diameter by 1016-mm (40-in) depth and develop up to 1800g in the smaller and intermediate sizes. Except in the sugar apphcation, operation with a two-speed motor (half speed for loading and full speed for purging) is typical. Hydraulic drives with variable-speed capability are commonly used in the chemical industiy To maximize the number of cycles per hour, a combination of electrical and mechanical braking is employed to minimize the deceleration period, which is a transition period of no value to the process. 

Two-winding motors may be built for constant torque, variable torque, or constant horsepower. Constant-horsepower motors are capable of handling the same horsepower at both speeds (i.e., higher torque at the low speed). Constant-torque motors can handle the same load torque at either speed (e.g., conveyor drives). Variable-torque motors are designed for loads in which load torque varies as the square of speed and horsepower varies as the cube of speed. Typical applications are as follows ... 

FOC drives are capable of providing precise speed control and are used for applications calling for high performance and precision (e.g. machine tools, high-speed elevators, mine winders, rolling mills, etc.). These drives are capable of regulating a number of variables at the same instant such as speed, position, acceleration and torque. 

Turboexpanders require variable flow control nozzles capable of withstanding the total pressure and acting as the flow control for the main gas stream through the plant. The variable nozzles are matched... 

Variation is an obvious measure for quality of conformance, but it must be associated with the requirements set by the specification to be of value at the design stage. Unfortunately, difficulty exists in finding the exact relationship between product tolerance and variability. Approximate relationships can be found by using process capability indices, quality metrics which are interrelated with manufacturing cost and tolerance (Lin et al., 1997). ... 

In the next chapter, we introduce the concepts of component manufacturing capability and the relationships between tolerance, variability and cost. The Component Manufacturing Variability Risks Analysis is then introduced, the first stage of the CA methodology, from which process capability estimates can be determined at the design stage. The development of the knowledge and indices used in the analysis... 

The associated cost of failure for the solenoid end assembly is calculated to be over 3 million for a product cost of 7.66 and production volume of one million units. This figure is for the tolerance stack failure mode alone as this is most important to the customer. Although the assembly variability risks are analysed, they are not taken into account in the final costs of failure. In conclusion, the process capabilities... 

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