Term Performance

In any laboratory where quality assurance is important, the performance of aU instruments, including FT-IR spectrometers, should be tested on a regular basis. Measuring the rms noise on the 100% line between, say, 4000 and 3800 cm and 2200 and 2000 cm at least once a week gives users a good indication as to whether the performance of their instrument is still acceptable. The American Society for Testing and Materials (ASTM) has approved an additional series of 

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Preliminary in-field applications have also confirmed the successful long-term performance of the AEBIL instrumentation in power plant environment. 

Aliphatic Isocyanates. Aflphatic diisocyanates have traditionally commanded a premium price because the aflphatic amine precursors ate mote expensive than aromatic diamines. They ate most commonly used in appHcafions which support the added cost or where the long-term performance of aromatic isocyanates is unacceptable. Monofuncfional aflphatic isocyanates, such as methyl and -butyl isocyanate, ate used as intermediates in the production of carbamate-based and urea-based insecticides and fungicides (see Fungicides, agricultural Insectcontroltechnology). 

PyCis usuaHy expressed in percentage, but the % sign is often omitted. Although many additives in the paint formulation are nonvolatile, they are often omitted from this calculation, because they represent a smaH fraction of the volume of a newly formed paint film and, in exterior paints, are often water-soluble materials leached out by rainfaH, and therefore wHl probably not factor into the long-term performance of the paint film. 

Catalyst Selection. The choice of catalyst is one of the most important design decisions. Selection is usually based on activity, selectivity, stabiUty, mechanical strength, and cost (31). StabiUty and mechanical strength, which make for steady, long-term performance, are the key characteristics. The basic strategy in process design is to minimize catalyst deactivation, while optimizing pollutant destmction. 

The general expression for involves both rj and Its final term performs an interpolation for mixed spin cases. 

Proper installation of new production and plant services systems is essential for long-term performance of these... 

The majority of heat-resisting alloys contain at least one element which is selectively oxidised (e.g. Cr, Si, Al). The resulting scale is highly protective, but depletion of the secondary element may occur if the diffusion rate of this element in the alloy is low. Then repetitious loss of the scale can be profoundly detrimental to long-term performance, since depletion of the alloying element near the surface may occur to such an extent that its concentration falls below the critical level for the exclusive reformation of the highly protective scale... 

The viscoelastic nature of the material requires not merely the use of data sheet information for calculation purposes, but also the actual long-term performance experience gained that can be used as a guide. The allowable working stress is important for determining dimensions of the stressed area and... 

This stability is important to plastics longterm performance. However, for some applications only short-term performance is desired before the product is discarded, as in the fast-food and packaging markets. In such cases it is considered advantageous for discarded plastic to degrade when exposed to microbes. There thus exists a requirement to develop or modify plastics possessing the properties required for their service life, but with the capability of degrading in a timely... 

The accurate application of this approach to the long-term performance of big elastomeric-structural bearings used in the construction of a large building in London, Lf.K., is well documented. " ... 

Work on the OB has clearly demonstrated that plant cell response to stress, including hydrodynamic stress, is a more complex process than was originally anticipated. Moreover, it highlights a number of cellular processes which may define immediate system response and longer term performance prospects of plant cell suspensions. 

Dybas Ml et al. (2002) Development, operation, and long-term performance of a full-scale biocurtain utilizing bioaugmentation. Environ Sci Technol 36 3635-3644. 

We have developed a thermomorphic catalyst system for the hydroformylation of higher alkenes. We have built a bench-scale continuous reactor and have used it to determine the long-term performance of the thermomorphic catalyst system. Longterm results (>400 h) using 1-octene and 1-dodecene show that the catalyst has high selectivity and no measurable loss in activity. 

The ET cover cannot be tested at every landfill site so it is necessary to extrapolate the results from sites of known performance to specific landfill sites. The factors that affect the hydrologic design of ET covers encompass several scientific disciplines and there are numerous interactions between factors. As a consequence, a comprehensive computer model is needed to evaluate the ET cover for a site.48 The model should effectively incorporate soil, plant, and climate variables, and include their interactions and the resultant effect on hydrology and water balance. An important function of the model is to simulate the variability of performance in response to climate variability and to evaluate cover response to extreme events. Because the expected life of the cover is decades, possibly centuries, the model should be capable of estimating long-term performance. In addition to a complete water balance, the model should be capable of estimating long-term plant biomass production, need for fertilizer, wind and water erosion, and possible loss of primary plant nutrients from the ecosystem. 

It is primarily the prospect of reduced mobility and volatility, with the expected improvement in long-term performance, which motivates the preparation of polymeric ultraviolet stabilizers. Work in this area was reviewed thoroughly by Bailey and Vogl in 1976 (1), and more recently by the author (2). The present paper describes recent synthetic work involving four classes of effective ultraviolet stabilizers salicylate esters (I), 2-hydroxybenzophenones (II), a-cyano-3-phenyl-cinnamates (III) and hydroxyphenylbenzotriazoles (IV). In each... 

Pyrolyzed catalysts obtained by heat treatment in Argon of active carbon impregnated with solution of the compound Co-tetramethoxyphenylporphirine (CoTMPP) are studied [9], Air gas-diffusion electrodes with this catalyst show low polarisation in a wide interval of current densities (up to 100 mA/cm2) and stable long-term performance. These catalysts are more suitable for use in magnesium-air cells operating at high current drains, but unfortunately their price is comparatively high. 

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