Performance range

Fig. 16. Resistance area (R ) product for HgCdTe photodiodes cooled to 77 K. The soHd line represents the theoretical limit, the dashed lines (—) and (- -) high and low performance, respectively. Dark current caused by defects lowers R and detector sensitivity. In the high performance range dark...

The first cell in the last tow of the table represents the Hartree-Fock limit the best approximation that can be achieved without taking electron correlation into account. Its location on the chart is rather far from the exact solution. Although in some cases, quite good results can be achieved with Hartree-Fock theory alone, in many others, its performance ranges from orfly fair to quite poor. We ll look at some these cases in Chapters 5 and 6. 

Figures 6-1 lA, B, and C indicate the capacity of various ejector-condenser combinations for variable sucdon pressures when using the same quandty of 100 psig modve steam. Each point on these curves represents a point of maximum efficiency, and thus any one curve may represent the performance of many different size ejectors each operating at maximum efficiency [1]. Good efficiency may be expected from 50%-115% of a design capacity. Note that the performance range for the same type of ejector may vary widely depending upon design condidons.

A typical performance range of capacides of rotary lobe vacuum pumps is shown in Figures 6-48A, 6-48B and 6-48C. Another set of curves for rotary lobe pumps, shown in Figure 6-49, provides the brake horsepower, airflow at inlet (CFM) (referred to as their standard volume at 70°F and 29.92 inch Hg abs discharge pressure—essentially atmosphere), and the temperature rise through a non-cooled (no internal or external cooling) vacuum. All data... 

Figure 12-59. Performance ranges for special high-speed/high-pressure, single-stage Sundstrand Compressors (except model HMC 5000) centrifugal compressors. Special impellers are available for performance outside the envelopes shown. Performance varies with the gas involved. (Used by permission Sundstrand Compressors Bui. 450, April, 1995. Sundstrand Fluid Handling Corporation.)...

Portable fuel-cell systems are systems that produce electricity for devices with a performance ranging from several watts to 10 kilowatts. The heat produced in the process is a by-product that is normally not used. The system has, therefore, to be cooled down by fans or cooling surfaces, etc. A wide range of applications is possible for fuel cells from small electronic devices like camcorders, mobile phones, laptops, etc. to electric tools, back-up systems, or power generation on boats or caravans. 

Of the four pharmacopeias, the U.S. pharmacopeia (USP) has the strietest requirements for delivered dose uniformity. Although the British pharmaeopeia (BP) allows the same performance range, the USP defines the range around the label claim and the BP defines the range around the average value. The FDA expeetation for delivered dose uniformity is currently tighter than that stated in all the pharmaeopeias. 

Membrane Properties. The performance range of ammonia-modified membranes in low pressure operation is indicated in Figure 6 along with the performance of the reference membrane (I, reference membrane IV, ammonia-modified membrane). The lower boundary of the performance range refers to a solvent-to-polymer ratio of 3, the upper boundary to a ratio of 4. While the salt rejection towards univalent ions of the ammonia-modified membrane is limited to below 80 %, the maximum low pressure flux is over 15 m /m d (approaching 400 gfd) at a sodium chloride rejection of the order of 10 %. This membrane thus exhibits the flux capability of an ultrafiltration membrane while retaining the features of reverse osmosis membranes, viz. asymmetry and pressure resistance. 

Perform range-finding to determine suitable enzyme concentration... 

Close Study of Cooling-Tower Pump Intakes Adds to Reliability Over Performance Range... 

The performance ranges and the best performance for the two most different feeds —distilled water and sea water—are summarized in Table II. The ranges are not to be averaged and the best performances are not to be considered freaks they are merely the nearest approach to an optimum evidently never yet reached. 

Performance capabilities and capacities can be evaluated using a separate test for each function of the lyophilizer. These tests focus on the operation of selected subsystems and the capacity for the specific functions during lyophilization. These subsystems include the heat transfer system, condenser, and vacuum system. An overview for testing of each major subsystem is presented in the following sections. Also included are examples and illustrations for performance ranges. These examples, however, do not, reflect the capabilities of a specific lyophilizer, nor are they intended to suggest any industry standard. 

As Figure 5.12 shows, Toray s PEC-1000 crosslinked furfuryl alcohol membrane has by far the best sodium chloride rejection combined with good fluxes. This explains the sustained interest in this membrane despite its extreme sensitivity to dissolved chlorine and oxygen in the feed water. Hollow fine fiber membranes made from cellulose triacetate by Toyobo or aromatic polyamides by Permasep (Du Pont) are also comfortably in the one-stage seawater desalination performance range, but the water fluxes of these membranes are low. However, because large-surface-area, hollow fine fiber reverse osmosis modules can be... 

Assurance that the equipment is properly qualified (i.e., installation, operational, and performance qualified), properly maintained, and currently within calibrated performance ranges (emphasis on scales and balances)... 

In this context, a review is presented of the complex chain of events affecting anode performance, ranging from the properties of precursors for filler cokes and binder pitches, through production of these raw materials and their fabrication into anode carbon, and concluding with anode performance evaluation in full-size prebake and Soderberg cells of different designs. 

Perform range-finding experiments with the individual mixture components or explore existing knowledge, to determine the toxicity of each component by finding the median effect concentration (EC50) for the endpoint of interest. 

The development of simpler, more economic processes for the production of polyethylene and polypropylene did not signify the end of MgCl2 catalyst research, but rather constituted the first phase. New, ever more sophisticated requirements, both in terms of process and product quality, have been emerging, steadily increasing the performance range required for the catalyst control of the polymer molecular structure (MWD, branching, steric purity), of its morphological properties (shape and particle size distribution), and supply of copolymers with controlled structures. 

Unit operations to be performed Range of batch sizes to be processed Capital expenditures and operational costs Anticipated occupational exposure limits (OELs) to be encountered... 

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