Ease of operation

This point, although of importance, is difficult to discuss. Aspects of interest 

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The spectroscopic methods, NMR and mass spectrometry for predicting cetane numbers have been established from correlations of a large number of samples. The NMR of carbon 13 or proton (see Chapter 3) can be employed. In terms of ease of operation, analysis time (15 minutes), accuracy of prediction (1.4 points average deviation from the measured number), it is... 

The mechanistic complexity of hydroboration-oxidation stands m contrast to the simplicity with which these reactions are carried out experimentally Both the hydrobo ration and oxidation steps are extremely rapid reactions and are performed at room tern perature with conventional laboratory equipment Ease of operation along with the fact that hydroboration-oxidation leads to syn hydration of alkenes and occurs with a regio selectivity opposite to Markovmkov s rule makes this procedure one of great value to the synthetic chemist... 

Portable scales generally have a platform near the floor with the indicator mounted on a column for ease of operation. These scales may be on wheels, and many are battery-powered. Capacities are generally less than 600 kg. Bench scales can be placed on a wheeled table for similar use. 

Chromatographic methods, notably hplc, are available for the simultaneous deterrnination of ascorbic acid as weU as dehydroascorbic acid. Some of these methods result in the separation of ascorbic acid from its isomers, eg, erythorbic acid and oxidation products such as diketogulonic acid. Detection has been by fluorescence, uv absorption, or electrochemical methods (83—85). Polarographic methods have been used because of their accuracy and their ease of operation. Ion exclusion (86) and ion suppression (87) chromatography methods have recently been reported. Other methods for ascorbic acid deterrnination include enzymatic, spectroscopic, paper, thin layer, and gas chromatographic methods. ExceUent reviews of these methods have been pubHshed (73,88,89). 

Multiple-hearth roasting offers ease of operation, abiUty to handle a wide variety of ores or blends, and Httle downtime. On the other hand, these furnaces are no longer being built because of their high capital and labor costs, relatively low sulfur dioxide off-gas, need for added fuel, and marginal opportunity for waste-heat recovery. 

The criteria for selection of laboratory reactors include equipment cost, ease of operation, ease of data analysis, accuracy, versatility, temperature uniformity, and controllabihty, suitability for mixed phases, and scale-up feasibility. 

Ease of operation Is the ( (piipment easy to operate )V a tenant or )V l)iiilding personnd Unless functions and actual operations of e(piipment can )e carried out easilv, th( v may l)e ignored or l)vpas.sed l)v piiid personnd and most often l)v paving tenants. 

Fluid couplings have a proven record of reliability and ease of operation. They thus have found wide application wherever a light load start and capticily control of drives is required as in fans and pumps. 

To have ease of operation and control a group of load or control points from one common location. 

In earlier years, to reach a remote area, where. separate telephone lines had not been laid it was normal practice to rttn them through the same poles as the HT power distribution lines (generally 11-33 kV). This was particularly true of internal communications of the electricity companies for ease of operation and to save costs and time. This commitnication was known as the magneto-telephone system. But the proximity of telephone lines to power lines adversely affected the performance of the telephone lines due to generation of overvoltages (Chapter 20) and eleetrical interferences (conductive and inductive interferences, discussed later) on the telephone lines by the power lines.. Some of these interferenees, particularly system harmonics, had the same frequency as the audio frequency of the telephone lines and alTected their audio quality. 

The funnel is capped with a rubber septum. For ease of operation, volume markings, corresponding to the amounts of reagents to be added, are put on the addition funnel. 

X-ray photoelectron spectroscopy (XPS) is currently the most widely used surface-analytical technique, and is therefore described here in more detail than any of the other techniques. At its inception hy Sieghahn and coworkers [2.1] it was called ESCA (electron spectroscopy for chemical analysis), hut the name ESCA is now considered too general, because many surface-electron spectroscopies exist, and the name given to each one must be precise. The name ESCA is, nevertheless, still used in many places, particularly in industrial laboratories and their publications. Briefly, the reasons for the popularity of XPS are the exceptional combination of compositional and chemical information that it provides, its ease of operation, and the ready availability of commercial equipment. 

It should be noted that when there is no jet reinforcement of the flow, i.e., the exhaust hood is used in its conventional mode, then in the two-dimensional form of the Aaberg principle the fluid flow velocity due to the exhaust decays approximately inversely proportionally to the distance from the exhaust opening. However, for three-dimensional exhaust hoods the fluid velocity outside the hood decays approximately inversely as the square of the distance from the exhaust hood. Thus in the three-dimensional conventional hood operating conditions the hood has to be placed much closer to the contaminant in order to exhaust the contaminant than is the situation for the two-dimensional hood (see section on Basic Exhaust Openings). Thus for ease of operation it is even more vital to develop hoods with a larger range of operation in the three-dimensional situation in comparison with two-dimensional hoods. 

The distribution of gas, air, water, steam, power, and electricity is not always a major item since the flexibility of distribution of these services permits designing to meet almost any condition. However, proper placement of each of these serv ices helps to insure ease of operation and orderliness and aids in reducing maintenance costs. 

The performance of reciprocating pumps provides for ease of operation and control. Depending upon the type of piston action, the fluid may be subject to pulsations unless accumulator or surge drums are provided. 

The use of an integral video screen in instruments presents very great advantages, both in the ease of operation and in the ability to develop and understand analytical methods. Complete analytical records can be stored in the instrument and a visual display of good calibration curves can be stored in memory and recalled at will. It is most useful to have a graphical display of atomisation peaks when using a furnace where a distinction can be made of the total absorbance peak and that due to the analyte absorbance. 

Auxiliaries are additional boiler fittings that provide controls for ease of operation. They may include additional valves (such as check valves on feed lines, nonreturn valves on steam distribution lines, and the various boiler system drain valves), gauges, connections, and devices to regulate FW, air, and fuel and to provide for the efficient production, pressure, temperature, quality, and flow of HTHW or steam. 

These operations are characterized by different reaction engineering properties. The transport of momentum, heat, and mass take place by different rates in the different operations, and the yield and selectivity obtained for a given chemical reaction will depend upon the type of operation employed. The operations also differ with respect to more loosely defined characteristics, such as ease of operation, and it can be noted in particular that some operations have been studied with considerably more thoroughness than others, and may consequently be designed with greater accuracy and reliability. 

Typical Reactor Design. Table 5.1 lists typical CVD production reactors which include cold-wall and hot-wall reactors operating at low or atmospheric pressures. The decision to use a given system should be made after giving due consideration to all the factors of cost, efficiency, production rate, ease of operation, and quality. 

In general terss, the purge-and-trap technique is the nethod of choice Cor detemining organic volatiles in water because of its ease of operation. If greater sensitivity is required, the closed loop stripping apparatus should be used. 

Ease of operation Automated and robotic systems Automated systems Fragility of fibres... 

Direct Packed, SCOT, large bore WCOT 200 ng per component Direct quantitation Ease of operation High sample capacity Flash vaporisation Decreased resolution (column requirements)... 

Hot split Column independent 50 ppm (FID) Ease of operation Independent of sample Rugged Qualitative analysis Flash vaporisation Thermal degradation Discrimination of higher boiling compounds possible Not suitable for trace analysis Poor, indirect quantification... 

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