Sleeve technique

The techniques generally used for inhibition of rocket propellants are sleeve technique, tape winding technique and casting technique and their salient features are as follows ... 

In order to reduce the steps involved during inhibition and make this technique more acceptable to ordnance factories for bulk production, inhibitor sleeve technique wherein most of these steps are eliminated, has been developed by Agrawal et al. [290, 291]. 

The inhibition of composite propellants is somewhat easier than that of DB propellants. The binders used for composite propellants (with or without fillers) have been reported for inhibition of composite propellants. Such inhibition systems possess stronger bonds with composite propellants and prove to be more compatible coupled with better shelf-life of the inhibited propellants. However, epoxy or novolac epoxy resin with or without inert fillers is generally preferred for the inhibition of composite propellants due to a combination of properties possessed by them. The inhibition is usually done by casting technique and inhibition thickness is usually required on higher side in order to make the missions successful. In India, thread winding technique or inhibitor sleeve technique is preferred where 2.5-3.0mm inhibition thickness is sufficient as against 3.5-4.0 mm in case of inhibition by casting technique . 

Following extensive laboratory trials, four experimental sleeves were first fitted to operational evaporators towards the end of 1980. A further 11 evaporator weld leaks occurred in 1981 and a fUrther 41 sleeves were fitted to by-pass defective and suspect welds. In parallel, work was in progress to examine whether the sleeving technique could be applied on a routine basis. A trial installation of 200 sleeves was conducted on the spare evaporator tube bundle in the latter part of 1982. A decision was then made to sleeve all the 3000 tube-to-tubeplate junctions in the three evaporators. Work on two of the units was completed in 1983 and the third unit was sleeved by March 1984. It was installed in the summer and PFR operated for the first time with three fiilly-sleeved evaporators in August 1984. 

Openings around water pipe entries and sewer exits that pass through concrete can be easily sealed using caulks. Many builders use plastic sleeves to protect metal pipes from corrosion when they pass through concrete. In this case, an effort can be made to leave a space around the pipe that can be sealed with caulk or backer rod and caulk. The same techniques can be used for pipes passing through block walls. 

Our preferred experiment of this type is the so called DEPT-edited HSQC which is both relatively artefact-free and sensitive. It also has one other major advantage up its sleeve. This experiment is not an absolute value technique like most of the others, but it allows for discrimination between different types of carbons. Methyl and methine carbons give crosspeaks that are phased opposite to the methylene carbons and so the results are best plotted on a colour plotter which can portray this clearly by plotting positive and negative cross peaks in different colors. 

Many of the various techniques associated with metal film preparation have recently been reviewed by Klemperer (76). Much of the catalytic work with thick continuous films has used a cylindrical reaction vessel (Fig. 7a). This cylindrical geometry permits a cylindrical sleeve of mica sheet to be inserved and used as the film substrate for epitaxial film growth... 

In this technique, the material, say ethyl cellulose, is first plasticized and then a sleeve of a definite size and shape is extruded. This sleeve is applied to the grain by a special technique using ethyl cellulose cement which is prepared by dissolving ethyl cellulose in cellosolve-diethyl phthalate (1 1) mixture or ethyl lactate-butyl acetate (1 4) mixture. 

This technique is universal and the inhibitor sleeve with the use of polyurethane (Formulation HTPB TDI BD 1 3.2 2) as a matrix and rayon thread as a reinforcement may also be similarly made for this purpose [292]. 

HPLC Waste Collection Absorption (skin) Low Nitrile double gloves, Tyvek sleeves (see previous statement), disposable laboratory coat Technique (use precautions when removing tubing to... 

Patching may be feasible for stopping leaks in vessels or storage containers, or in situations when the contents cannot be transferred. The usual patching method is to affix some type of mechanical device in, over, or around the leak to restrict flow. A variety of clamps, capping tools, and sleeves are commercially available for this purpose. For piping systems, one technique... 

Besides the mechanical wiping techniques several other efficient countermeasures against inorganic and organic fouling or film formation on quartz sleeves are possible ... 

A Carius tube was charged with 2-(ethylsulfanyl)acrylonitrile (6 1.13 g, 0.01 mol) and a few crystals of hydroquinone. The tube was then cooled to - 78 C and chlorotrifluoroethene (1.7 g, 0.015 mol) was introduced using standard vacuum-line techniques. The tube was sealed and then heated in an oil bath at 120 C for 8 h (the Carius tube was in a metal sleeve and the oil bath was behind a safety shield). The tube was allowed to cool to rt and then placed in liquid Nj and opened. After allowing to warm to rt, the residue was distilled to give 7 yield 1.79 g (83%) bp 94-96 C/0.05 Torr. 

It is not always possible to tell by inspection whether glass or tools are hot. The glassworking flame is always hot, so hands and sleeves must be kept out of harm s way. When making T-joins or bends it is necessary to develop a technique of holding and turning the glass in the left hand in such a manner that the hand does not pass through the flame. 

Specially designed injection port inlet sleeves have been available on the market for direct and hot on-column injection.In the direct injection mode, 2 -mm-lD inlet sleeves are commonly used, which permit a sufficient space for sample evaporation however, the on-column mode is usually performed by inserting a 26-gauge needle inside a 0.53-mm-lD column. Direct injection is more favorable because it is less problematic than the hot on-column mode. Because the liner can trap nonvolatile residues before entering the column, this technique is suitable for dirty samples. Compared to the splitless mode, the direct injection is advantageous, involving less adsorption of the solutes and better sensitivity. However, with this technique, the adsorption of the sample may occur on the inlet sleeve during the evaporation process.In this case, the hot on-coIumn mode offers more benefits. 

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