Tube aluminium

The end window of the tube must be thin enough to permit the weaker radiations to enter the tube (aluminium, 6-8 mg cm-2 mica, 2 mg cm-2) but even so alpha particles and very weak beta emissions are either completely or partially absorbed. The emissions from the biologically important isotopes of tritium and carbon-14 fall into this category and alternative detectors should be used for these isotopes. 

The heater must be designed with copper tubes, aluminium hns, and steel connections with male thread. 

Ross et al. [6] analysed samples of soil leachates from laboratory columns and of soil pore water from field porous cup lysimeters for aluminium by atomic absorption spectrometry under two sets of instrumental conditions. Method 1 employed uncoated graphite tubes and wall atomisation method 2 employed a graphite furnace with a pyrolytically coated platform and tubes. Aluminium standards were prepared and calibration curves used for the colorimetric quantification of aluminium. Method 1 gave results which compared favourably with method 2 in terms of both sensitivity and interference reduction for samples containing 1-15 uM aluminium. 

The case of thin-skin regime appears in various industrial sectors such as aerospace (with aluminium parts) and also nuclear in tubes (with ferromagnetic parts or mild steel components). The detection of deeper defects depends of course on the choice of the frequency and the dimension of the probe. Modelling can evaluate different solutions for a type of testing in order to help to choose the best NDT system. 

On Line Eccentricity Measurement during Fabrication of Aluminium Tubes. 

Meanwhile, the organic compound can be prepared for analysis whilst the sealed end C (Fig. 72) of the Carius tube has been cooling dow n. For this purpose, thoroughly clean and dry a small tube, which is about 6 cm. long and 8-10 mm. w ide. Weigh it carefully, supporting it on the balance pan either by means of a small stand of aluminium foil, or by a short section of a perforated rubber stopper (Fig. 73 (A) and (B) respectively) alternatively the tube may be placed in a small beaker on the balance pan, or suspended above the pan by a small hooked wire girdle. 

Dihydroxyacetophenone. Finely powder a mixture of 40 g. of dry hydroquinone diacetate (1) and 87 g. of anhydrous aluminium chloride in a glass mortar and introduce it into a 500 ml. round-bottomed flask, fitted with an air condenser protected by a calcium chloride tube and connected to a gas absorption trap (Fig. II, 8, 1). Immerse the flask in an oil bath and heat slowly so that the temperature reaches 110-120° at the end of about 30 minutes the evolution of hydrogen chloride then hegins. Raise the temperature slowly to 160-165° and maintain this temperature for 3 hours. Remove the flask from the oil bath and allow to cool. Add 280 g. of crushed ice followed by 20 ml. of concentrated hydrochloric acid in order to decompose the excess of aluminium chloride. Filter the resulting solid with suction and wash it with two 80 ml. portions of cold water. Recrystallise the crude product from 200 ml. of 95 per cent, ethanol. The 3 ield of pure 2 5-dihydroxyacetophenone, m.p. 202-203°, is 23 g. 

Method 1 (with acetyl chloride). Equip a dry 500 ml. round-bottomed or bolt-head flask with a reflux condenser, and fit the top of the condenser with a two hole cork, one opening for a separatory funnel and the other for a delivery tube connected to an inverted funnel which dips just below the surface of about 200 ml. of water in a beaker (compare Fig. II, 13, 8). Place 40 g. of anhydrous, finely-powdered aluminium chloride (see Section IV,2) and 88 g. (100 ml.) of dry A.R. benzene in the flask and cool the latter in a bath of cold water (not ice water since benzene may crystallise). Through the separatory funnel at the top of the condenser add 29 g. (27 ml.) of redistilled acetyl chloride slowly during half an hour and shake the flask frequently to ensure thorough mixing of the... 

Method 2. Into a 500 ml. round-bottomed flask place 120 ml. of dry A.R. benzene, and 35 g. (29 ml.) of redistilled benzoyl chloride. Weigh out 30 g. of finely-powdered, anhydrous aluminium chloride into a dry corked test-tube, and add the solid, with frequent shaking, during 10 minutes to the contents of the flask. Fit a reflux condenser to the flask, and heat on a water bath for 3 hours or until hydrogen chloride is no longer evolved. Pour the contents of the flask wliile still warm into a mixture of 200 g. of crushed ice and 100 ml. of concentrated hydrochloric acid. Separate the upper benzene layer (filter first, if necessary), wash it with 50 ml. of 5 per cent, sodium hydroxide solution, then with water, and dry with anhydrous magnesium sulphate. Isolate the benzophenone as in Method 1. The yield is 30 g. 

Place 35 ml. of a M solution of aluminium tsopropoxide or 7 g. of solid aluminium tsopropoxide, 450 ml. of dry isopropyl alcohol and 21 g. of purified benzaldehyde (Section IV,115) in a 1 litre round-bottomed flask. Fit a short reflux condenser (no water in the cooling jacket) or better a Hahn condenser (2) (containing a 1 cm. layer of ethyl alcohol in the iimer tube) to the flask and arrange for slow distillation from a water bath at the rate of 3-6 drops per minute. Continue the heating until a negative test for acetone is obtained after 5 minutes of total reflux (6-9 hours) if the volume of the mixture falls below 200 ml. during the reduction, add more isopropyl alcohol. Remove the reflux or Hahn condenser and distil off (Fig. II, 13, 3) most of the isopropyl alcohol under atmospheric pressure from a suitable oil bath. Hydrolyse the... 

Specification for wrought aluminium and aluminium alloys for engineering purposes bars, extruded round tubes and sections 7,13/1991 B.S 1474/1987 6362, 209-1. 2... 

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