Glass tubing basics

For a small amount of material (<0.1 g), the method is simple and easy, using the basic technique of glass blowing. A piece of borosilicate glass tube, 5-6 mm inside diameter and about 30 cm long, is washed and dried in advance (Fig. A.2, (A)). First, one end of the tube is sealed with a narrow flame of a gas-oxygen torch. This is done by heating... 

Any substance that somehow changes with alterations in its temperature can be used as the basic component in a thermometer. Gas thermometers work best at very low temperatures. Liquid thermometers are the most common type in use. They are simple, inexpensive, long-lasting, and able to measure a wide temperature span. The liquid is almost always mercury, sealed in a glass tube with nitrogen gas making up the rest of the volume of the tube. 

Drawing a tube off to a spindle is the simplest of the basic glassworking operations. It is a convenient alternative to cutting glass tubing when short lengths are required and it is the preliminary stage to many other operations. 

The basic apparatus consists of a large diameter (about 25 mm.) glass tube to which are attached at least two stopcocks, a closed-end manometer, and a large stopcock, which is used to isolate the manifold from the vacuum pump. 

There are two basic test configurations. The first is a blind flange setup where the sample is clamped between a glass tube containing the liquid and a temperature-controlled heater. In this test, two samples can be tested under identical conditions. The second is a retaining cup clamped onto the sample. Figure 9.7 illustrates the two types of test cells. 

To learn basic glassworking by bending and fire-polishing glass tubing. 

Basic Glassworking Working with Glass Tubing Cutting glass tubing... 

Cobalt Tetra-carbonyl, Co(C0)4 or Co2(CO)g.—This compound may be prepared by passing carbon monoxide at a pressure of 40 atmospheres over reduced cobalt at 150° C. The higher the pressure the more rapid is the formation of the earbonyl.7 It forms as fine, orange-coloured transparent crystals, which are best preserved by hermetically sealing them in a glass tube in an atmosphere of hydrogen or of carbon monoxide. Upon exposure to air decomposition takes place resulting in the formation of a basic cobalt carbonate. With bromine it yields cobalt bromide and carbon monoxide ... 

Methyl violet is gradually turned blue green, and ultimately a pale salmon colour by nitric peroxide. It is much less sensitive than starch iodide. For the test, 2 5 g. of the dried sample, of explosive is placed in a glass tube 29 cm. long and i 5 cm. internal diameter. The sample is pressed down to occupy a depth of 5 cm. and a methyl violet paper is placed in the tube with its lower edge 2 5 cm. above the explosive. The tube is inserted in a bath at 154 to 135 so that about 6 to 7 mm. of the tube projects from the bath. After twenty minutes the tube is partially withdrawn to examine the paper, and this is repeated at intervals of five minutes until the paper becomes salmon-pink. The time of the test should be at least thirty minutes. The papers are prepared by dipping Schleicher and Schiill s filter paper No. S97 in a solution of pure rosaniline acetate (prepared from 0 25 g. basic rosaniline, 0168 g. methyl violet (crystal violet), 4 c.c. glycerine, 30 c.c. water, made up to too c.c. with pure 95 per cent, alcohol. The dried paper is cut into strips 2X7 cm. 

Because an electrode does not function as electrode in DC or alternating current high-frequency discharge, the electrode system could be kept outside a glass reactor (capacitive external electrodes) or a coil around a glass tube (inductively coupled external electrode) can be used to create plasma. These modes of coupling could be dealt as a factor in the system-dependent aspect of plasma polymerization, i.e., the basic plasma polymerization remains the same. 

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