Guards techniques

The success of a specific technique will depend on whether, as a by-product of the technique, sizable stress levels in the plastic product may result. Guarding against potential stresses in the assembly is a very important aspect of complete product design. There are many techniques that provide assembling all kinds of products. Each have technical and/or cost advantages and limitations. Examples of a few are reviewed in this section with more information in Chapter 3, BASIC FEATURE and FEATURE INFLUENCING PERFORMANCE. 

The useful life of hplc columns can be extended by proper treatment, in particular by the use of guard and scavenger columns. Pretreatment of samples is often necessary, eg very dilute samples may require concentration, or complex samples may need to be cleaned up. Some of the more important techniques are considered. 

INDUSTRIAL SAFETY PROVISIONS. In the design of the APE and associated operational shield, conventional machine design practices are used to protect operators from hazards associated with moving parts. Proper techniques for guarding of hazardous machine areas are used, including the use of interlocks In the control system to prevent movements until certain conditions are satisfied, or to stop movements In emergency situations... 

The technique of pellet preparation and the guard-ring electrode cell were described previously (8). The density of the pellets is 61% of the real zeolite density. No structural damage is observed with x-ray diffraction after pellets are made. 

Fig. 6. Conductivity methods, a) guard ring techniques, b) potential probe technique...

Thus, it is concluded that as far as possible experiments should be made on single crystal samples using guard ring techniques under conditions where the ambient atmosphere may be rigorously controlled. In the case of polymers single crystal samples of any size are virtually impossible to obtain. 

A comparison of guarded hot plate, transient plane source and modified hot wire methods has been made54 using polyurethane foam, and the strengths and weaknesses of the techniques discussed,... 

The usual precautions must be taken in all these reactions, to guard against the possibility of moisture being present. The technique of the method will be apparent from the following. ... 

This reaction is carried out using the steel pressure vessel and techniques described in Section 2.17.2, p. 97. To the dry pressure vessel add 7.46 g (0.05 mol) of co-nitrostyrene (Expt 6.136), about 0.1 g of hydroquinone (a polymerisation inhibitor) and 15 ml of dry toluene. Fit a rubber bung carrying a calcium chloride guard-tube and cool the vessel to — 78 °C in an acetone-Cardice bath. During the cooling process set up the acetone-Cardice... 

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