Bulky apparatus

ASTM D4304 specifies three machines for flex-cracking. The Scott Flexer is included specifically to test for ply separation of composites such as belting or tyres and is not used for rubber alone. It is a somewhat bulky apparatus in which the test pieces are reciprocated over a rotatable hub whilst held in tension. The arc of contact is about 165° but was at one time was erroneously given as 135°, resulting in at least one out of spec machine... 

Vibratory test apparatuses are relatively cheap to build and run, and have low power consumption, while flow rigs are bulky, expensive to build and run, and have high power consumptions but have the advantage that they simulate more closely practical conditions of hydrodynamic cavitation. On the other hand, the damage rate is higher in the vibratory tests than in the... 

Filtration apparatus is available to remove any size, but the very fine particles require a deep, bulky and expensive filter, which itself sets up a high resistance to air flow and therefore requires high fan power. A practical balance must be reached to satisfy the requirements ... 

Supplied Air Breathing Apparatus (SABA) SABA, when combined with an emergency escape bottle, provides the safest combination for respiratory protection. It provides air from a remote supply connected via an extended air hose, and has an escape cylinder rated for five to fifteen minutes of use, in case the remote air supply in compromised. SABAs are not as bulky or cumbersome as SCBAs, and enable longer work periods. The disadvantages of SABAs are the air lines can get tangled, and damaged by cuts, abrasions, and chemical contamination. Also, the airlines will limit your range, and the user will have to exit in the same manner as he or she entered the area. 

Complications reported with this type of intervention are rare, Rupture of the annulus is reported. The tricuspid valve may also be damaged if a large diameter balloon catheter has been passed inadvertently through the tricuspid valve chordae. After inflation, the balloon is relatively bulky and as it is removed the tricuspid valve apparatus may be disrupted causing regurgitation. A procedure-associated death rate of 0.24% and a major complication rate of 0.35% were found in a large study comprising 822 balloon pulmonary valvuloplasty procedures (15). 

Following our results with diethylsilane and diphenylsilane, we consider the evaluation of diisopropylsilane or di-tert-butylsilane. Diisopropylsilane and di-tert-butylsilane may both be bulky enough that they would allow only one addition however diisopropylsilane (bp 96 °C) has a lower boiling point than di-tert-butylsilane (bp 128 °C) and would be easier to be removed at the end of the reaction by simple evaporation on a rotary evaporation apparatus. Unlike the two previous silanes, diethylsilane and diphenylsilane, diisopropylsilane was not commercially... 

The apparatus essential to the modern chemical philosopher is much less bulky and expensive than that used by the ancients. An air pump, an electrical machine, a voltaic battery (all of which may be upon a small scale), a blow-pipe apparatus, a bellows and forge, a mercurial and water gas apparatus, cups and basins of platinum and glass, and the common reagents of chemistry, are what are required. All the implements absolutely necessary may be carried in a small trunk and some of the best and most refined researches of modern chemists have been made by means of an apparatus which might with ease be contained in a small travelling carriage, and the expense of which is only a few pounds. 

Solute concentration and sample recovery is similar to the Ryhage device but the apparatus, though more bulky, is somewhat easier to operate. An alternative system was devised that employed a length of porous polytetrafluorethylene (PTFE) tube, as opposed to one of sintered glass, but otherwise functioned in the same manner. 

Other examples of flow injection systems are also found in the recent literature [160]. However, the problem of these apparatuses is that they are quite bulky, requiring pumps, valves and reactors, so that they are not easily miniaturized and are suitable only for experiments on animals or during surgery where the patient is immobilized. 

Inspired by the contribution of the carbene-like resonance structure, the homopolymerization of isocyanide giving rise to the formation of poly(iso-cyanide) has attracted much attention [3, 4]. On storage, or distillation, isocyanides that lack bulky AT-substituents tend to form solid materials, which had been supposed to be poly(isocyanide)s. However, this polymerization , (or resinification), largely depended upon the nature of the glass surface of the apparatus used for storage or distillation and, therefore, was poorly reproducible. Moreover, no structural information was provided for these materials, making the evaluation of the polymerization systems difficult. The historical background has already been overviewed by Millich in two reviews published in 1972 and 1980 [3, 4]. 

Cyclone separators can be effective as collection devices in SFC. However, they tend to be best suited for semipermanent applications, like preparative-scale chromatography. They are not user friendly for the separation of a large number of different samples in a short time. Each fraction requires a separate cyclone separator. For modest scale separations, the cyclone separators are bulky, with a very large internal surface area, which is difficult to clean out. Because they are subjected to relatively high pressures, they are usually made of stainless steel. Connections are usually made with large-diameter stainless-steel tubing and the whole apparatus is bolted to some sort of rack mount. One could think of this approaches a scaled-down pilot plant. 

Figure 12.4 Miniature size X-ray generator and detector. These probes are used with portable apparatus though their control modules or power units are nevertheless more bulky (reproduced courtesy of Amptek Inc.).

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