Short-term performance

Noise is either measured as the peak-to-peak or root-mean-square (rms) value. Peak-to-peak noise is simply the difference between the maximum and minimum values of the 100% line in a given spectral region, whereas the rms noise is the standard deviation of all data points in this region. Because the peak-to-peak noise is determined by the noise excursion at only two wavenumbers, the rms noise is a statistically more valid measure of the noise level. For a 100% line 

Since signal-to-noise ratio (SNR) increases with the square root of the measurement time, t, the amplitude of the rms noise on the 100% line should always decrease with the square root of the number of scans, N. The SNR may be calculated from the rms noise on the 100% line as 

The SNR of many FT-IR spectrometers designed for operation in the mid-infrared spectmm is usually worse between 600 and 400 cm than in any other spectral region. There is also a greater difference in the performance of commercial FT-IR spectrometers in this spectral region than in any other, as some manufacturers have taken more care to optimize the performance in this region than others. Three reasons account for the poor performance of mid-infrared spectrometers below 600 cm  

The mid-inffared energy emitted by any incandescent source is lowest at low wavenumber. 

The efficiency of many mid-infrared beamsplitters is usually worse between 600 and 400 cm than at higher wavenumbers unless a Csl substrate has been specified. 

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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... 

Zhang, Advani, and Prasad [51,52] also used microfabrication techniques in order to develop a thin, perforated copper foil and use it as a cathode DL in a PEMLC. In addition to the metal DL, an "enhancement" layer was used that consisted of a porous material locafed befween the perforated copper foil and fhe LF plate (CLP was used in fhis study). This layer improved the overall short-term performance and wafer managemenf of fhe cell. Flowever, the authors did not discuss any possible long-term issues related to contaminahon of the membrane due to the use of a copper DL. 

Even though it may be relatively easy to characterize the short-term performance of a salt cavern facility by a relation directly relating the maximum possible flow rate to the in-situ gas volume and the number of cavities available the same is not true for porous reservoirs where the dynamic aspect (effect of injection/withdrawal profiles) is important. 

The quality and mechanical reliability areas have used statistical methodologies to design and implement their successful improvement programs. Using statistically valid data and analysis provides a rational assessment of a system s performance. Applying these techniques to process safety systems will support an efficient and effective improvement effort. Statistically valid data will also avoid overreaction to short-term performance anomalies that may not accurately reflect performance of the process safety system such data will help identify the actual performance improvement opportunities. 

The sample catalysts, prepared from CoorsTek supports, were evaluated by comparing their performance with that of the industrial catalyst, C-11 NK. Preliminary evaluations (Catalysts 1-6) led to the development of Catalyst 7, which showed a slightly better short-term performance and a 20% improvement in the shift reaction when compared to C-11 NK. Catalyst 7 contained 1.8% Ni, 0.15% Mg, and 0.1% potassium (K), on 99% alumina with 0.2-... 

ISO 11248, Plastics—Thermosetting moulding materials—Evaluation of short-term performance at elevated temperatures, 1993. 

BS 2782, Method 136, Determination of the short-term performance of thermosetting moulding materials at elevated temperatures, 1994. 

Short term performance of biostabilizer is enhanced when biostabilizer is able to diffuse fast to the surface of product but this fast diffusion may also decrease its long-term performance. The delivery rate of OIT was controlled by its... 

Since safety achievements in an organization are a direct reflection of its culture, and since it takes a long time to change a culture, short-term performance measures should be examined cautiously as to validity. 

To achieve maximum adhesive properties at the higher temperatures (e.g. 538 0 PBI like other high temperature adhesives, must be postcured. The final postcure temperature depends upon the maximum use temperature. Postcure temperatures as high as 454 C have been employed. The high temperature postcure induces cross-linking in the polymer which is generally reflected in lower room temperature TSS (more brittle) but improved short term performance at elevated temperatures. A PBI similar to Imidite 850 is available in experimental quantities and is still under evaluation as an adhesive (4). ... 

These adhesives offer the best short-term performance of any adhesives at elevated temperatures. PBI adhesives, however, oxidize very rapidly and are not recommended for continuous use at temperatures above 232°C. PB1 adhesives require a cure at 316°C. As with polyimide adhesives, release of volatiles during cure contributes to a porous adhesive bond. These adhesives are supplied as very stiff, glass-fabric-reinforced films and are very expensive. Their applications are limited by a long, high-temperature curing cycle. 

By far, for short term performance, maintenance of the overall heat balance on a continuing basis is of most importance - without regard to which specific facilities are implemented to achieve it. 

The thermal performance of polymers is described in terms of both short- and long-term effects and can result from changes which are physical or chemical. Short-term performance is often expressed in terms of heat distortion temperature (HDT). This measures the temperature at which a material distorts by a certain amount under a particular stress. HDT provides less information than a plot of flexural modulus versus temperature but is convenient for quick comparisons of materials. In amorphous and unfilled crystalline materials HDT is close to T. In crystalline materials HDT can be enhanced to temperatures close to the melting point by the addition of reinforcing fibres. Table 3.1 summarises Tg, and HDT values for some reinforced and unreinforced PAEK. 

Many athletes are tense prior to the start of competition hence, they may become nauseous if the wrong types of foods are eaten. Also, the meal should be cleared rapidly from the stomach and be low in undigestible material such as plant fiber. Carbohydrates are the most rapidly utilized and promote the best short-term performances from athletes, whereas fats and proteins require much longer for digestion and are best suited for slower paced events that are conducted over longer periods of time. 

IMI 834 has useful strength up to 600 °C (1110 °F). IMI 834 is regarded as having long term creep performance up to around 600 °C (1110 °F) and good short term performance up to significantly... 

Polybenzimidazole. As illustrated in Fig. 7.32, polybenzimidazole (FBI) adhesives offer the best short-term performance at elevated temperatures. However, FBI resins oxidize rapidly and are not recommended for continnons use at temperatures over 450°F. 

A short-term performance test demonstrated that the 10-kW class module is capable of meeting the design specifications for full load and partial load operations. Figure 9.13 shows the various data recorded during the test. The DC power output of 12.7 kW is obtained under full load operation at 76% fuel utilization, analogous to the electrical efficiency of 50% HHV. The operational characteristics during the thermally self-sustained operation are listed in Table 9.3. 

For companies already struggling to meet the demands to provide sustainability and other operational data, the financial market s increasing interest in operating information may seem like just another burdensome effort and expense. In reality, it is an enormous opportunity. Financial numbers are strong short-term performance indicators, but they do not always tell the full story. To the trained eye, nonfinancial operational metrics can help complete the narrative, especially when it comes to projecting mid-to long-term performance. 

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