Recommended procedures

Surface treatment has been studied systematically for a number of non-ferrous metals and alloys and recommended procedures have been proposed (3). These recommendations take into account that the proposed treatment must  

Therefore the proposed solutions may be compromises between some of these requirements. Furthermore, other techniques not mentioned here may be well suited too (e.g. cold rolling of copper), but their absence is explained by the fact that they were not examined and evaluated. 

In the recommended procedures turning parameters refer to Table III-3, slicing and dicing parameters to section 4, and etching is carried out as indicated in section 5. 

Procedure. 1 ml of serum or plasma is extracted once with 4 ml hexane following the addition of 2 ml ethanol. The hexane layer is separated by centrifugation at 1500 x g for 5 min and the hexane evaporated under N2 at 70°C the residue is dissolved in 50 p spectroscopic grade hexane. The tocopherols are determined by HPLC by the method given in section (b) below. 

HPLC grade hexane and HPLC grade methyl-f-butyl ether 2.0 ml/min 

This method is applicable to a wide range of tissues and should give recoveries 0.5-1.0 ng of a-, / - and y-tocopherols better than 95% overall greater sensitivity can be achieved by the use of an electrochemical detector. For measurement of tocopherols in foodstuffs it may be necessary to adapt the extraction procedure somewhat, and care must be taken to ensure the homogeneity of the sample. 

Procedure. Approximately 250 mg of tissue is homogenized on ice in 10 vol of 75% ethanol in water using a Polytron tissue homo-genizer (Kinematica, GmBH) for 1 min at the maximum speed. 12.5 vol of ice-cold hexane (HPLC grade) are added and the mixture vortex mixed for 30 s. Following centrifugation at 1500 xg for 5 min, the supernatant hexane fraction is removed and may be stored for up to 48 h at — 20°C before analysis without loss of tocopherols. 101 /d of sample are used for HPLC. 10/d of sample are used for HPLC. 

The authors state that the detection limit for a-tocopherol was of the order of 1.0 ng at a signal to noise ratio of 5, and the recovery of a-tocopherol added prior to homogenization was 90% the coefficient of variation of the method was 4.7%. 

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Recommended procedures for use with Rockwell and superficial Rockwell tests are detailed in ASTM E18 (2). 

In joining reinforced thermosetting pipe it is particularly important that the pipe be cut without chipping or cracking it. It is also important to sand, file, or grind any mold-release agent from the surfaces to be cemented. Joints are built up layer by layer of adhesive-saturated reinforcement by following the manufacturer s recommended procedure. Application of adhesive to the surfaces to be joined and assembly of these surfaces shall produce a continuous bond and provide an adhesive seal to protect the reinforcement from attack by the contents of the pipe. Unfilled or unbonded areas of the joint are considered defects and must be repaired. 

The TCP approach is relatively simple and can be easily applied to studies involving comparisons of different equipments, different processes, or even parts of processes. CCP has now emerged as the most realistic approach that can be employed in economic project analyses. It is the recommended procedure for pollution-prevention studies. The LCC approach is usually applied to the life-cycle analysis (LCA) of a product or seiwice. It has found occasional application in projec t analysis. 

The method of reporting mel consumption varies among different industries and also among countries. Trade associations usually have recommended procedures. Thus the Diesel Engine Manufacturers... 

Calculating the resistance of each current-carrying component separately is a very cumbersome and lengthy procedure, in addition to being not very accurate due to the large number of approximations. Some of the joints and components may still have been omitted from these calculations. The easier and more often recommended procedure is to measure the resistance between the extreme ends of each feeder in its ON condition by an Ohm-meter. This resistance will also include the contact resistance of each terminal and joint. 

Fractionally distd under vacuum, then fractionally crystd twice from its melt. Impurities include acetic acid, methyl amine and H2O. For detailed purification procedure, see Knecht and Kolthoff, Inorg Chem 1 195 1962. Although /9-methylacetamide is commercially available it is often extensively contaminated with acetic acid, methylamine, water and an unidentified impurity. The recommended procedure is to synthesise it in the laboratory by direct reaction. The gaseous amine is passed into hot glacial acetic acid, to give a partially aq soln of methylammonium acetate which is heated to ca 130° to expel water. Chemical methods of purificatn such as extractn by pet ether, treatment with H2SO4, K2CO3 or CaO can be used but are more laborious. 

For example in paint shops, TCE evaporates and causes air pollution. The contaminated air has 250 ppm TCE in it and this can be fed to a moving bed reactor at 300°C that is charged with OXITOX (Chovan et al, 1997) The kinetics must be studied experimentally. The experimental setup is shown in Figure 4.5.1 and the following description explains the recommended procedure. In the experimental unit shown, the feed is contained under pressure in a gas cylinder. Two percent of the feed is saturated by TCE and diluted with the rest of the feed. The rate is calculated as ... 

The inspection process involved considerable work, due to the amount of damage experienced. The following steps were involved in the inspection process they can be considered typical of recommended procedures ... 

A VCM (vinyl chloride monomer) production unit uses three vertically mounted agitated reactors for the polymerization of vinyl chloride. Crude material balances infer about 8 to 10% monomer losses. Describe how you would go about assessing whether these losses are due to leaks such as fugitive air emissions. Be specific in recommending procedures and instruments. 

Bohn, M. P., and J. A. Lambright, Recommended Procedures for Simplified Pxiernj Event Risk Analyses, February 1988. 

The most reliable method of preparing benzofuroxans is by decomposition of o-nitrophenyl azides. Decomposition can be achieved by irradiation, or more usually by pyrolysis temperatures between 100° and 1.50° are commonly used. Refluxing in glacial acetic acid is the recommended procedure for 4- or 5-sub-stituted 2-nitrophenyl azides, but with 3- or 6-substituted compounds higher boiling solvents are usually necessary. Quantitative studies on the reaction rate have been made, and a cyclic transition state invoked, an argument which has been used to account for the greater difficulty of decomposition of the 6-substituted 2-nitrophenyl azides. Substituent effects on the reaction rate have also been correlated with Hammett a constants, ... 

The vertical thermosiphon reboiler is a popular unit for heating distillation column bottoms. However, it is indeed surprising how so many units have been installed with so little data available. This indicates that a lot of guessing, usually on the very conservative side, has created many uneconomical units. No well-defined understanding of the performance of these units exists. Kern s recommended procedure has been found to be quite conservative on plant scale units yet it has undoubtedly been the basis for more designs than any other single approach. For some systems at and below atmospheric pressure operation, Kern s procedure gives inconsistent results. The problem is in the evaluation of the two-phase gas-liquid pressure drop under these conditions. 

The recommended procedure for seizing a wire rope is as follows ... 

After testing for soundness it will be necessary to safely introduce gas into the pipework displacing the air or inert gas that is in it. Similarly, if pipework is decommissioned for any reason fuel gas must be displaced by air or inert gas. This is a requirement of the Gas Safety (Installation and Use) Regulations, Regulation 21. Guidance on recommended procedures is given in the British Gas publication Purging Procedures for Non-Domestic Gas Installations (IM/2). 

Figure 58.30 Illustration of recommended procedure for measuring chain length...

Standard tests are the American and the German . Several other continental standards are essentially based on the German. The present British standard relates only to laboratory glassware. The German and American standards differ in a number of details and to try to establish an international uniformity the ISO have issued recommended procedures ". A new British standard in preparation will be based on these procedures. 

The ASTM have established a recommended procedure for alternating-immersion stress corrosion tests in 3-5% NaCl solution (ASTM G44 1988). 

Recommended methods for assessing the corrosivity of waters, including flowing potable waters, are described in ASTM 02688 1983. Three procedures are described in which test specimens in the form of wires, sheets or tubes are placed in pipes, tanks or other equipment. The test assembly for the first of these consists of three helical wire coils mounted in series on, and electrically insulated from, a supporting frame. The assembly must be installed so that flow is not disturbed and turbulence and high velocities, e.g. of more than 1 -53 ms , are avoided. A minimum test period of 30 days is recommended. Procedures for the other specimen forms are given in the standard. 

The 1,2-dibromocyclohcxane was prepared by the method of Snyder and Brooks 2 If the cyclohexene is cooled to ca —30° with a dry ice-isopropyl alcohol bath and the bromine is not diluted, it is possible to run this preparation on a threefold scale in one-third of the recorded time The product was always purified by the recommended procedure. 

Many operations involving chemical reactions are potentially dangerous, and in such cases recommended procedures must be carefully followed and obeyed. All laboratory workers should familiarise themselves with local safety requirements (in some laboratories, the wearing of safety spectacles may be compulsory), and with the position of first-aid equipment. 

The ASME Pressure Vessel Code [1] and the API codes or recommended procedures [10, 13, 33] recognize and set regulations and procedures for capacity design, manufacture and installation of rupture disks, once the user has established the basis of capacity requirements. 

A word of caution should be added with regard to the calculation of the burn-out flux for a pressure intermediate to the main pressure groups that have been correlated this calculation must not be done by taking intermediate y values from Table II. The recommended procedure is to estimate the burn-out flux for the required conditions for the main pressure groups above and below the required pressure, and then to interpolate linearly. It must be also emphasized that while the above correlations can be used with confidence within the experimental ranges of the data, extrapolation outside these ranges should not be taken very far without allowing for a possible reduction in the accuracy obtained. 

A number of international organizations and scientific meetings play a pivotal role in the RM and CRM world. Without their involvement there would be few reference materials and little cooperation. Users of reference materials should ensure that they monitor the activities of these organizations and understand the consequences of any changes in recommended procedures or guidelines. 

This is recognised as a problem, and the recommended procedure from the Organic Food and Farming Standards (1992) is to allow suckled calves to develop natural immunity by grazing grass with their mothers. If there is a known farm problem, then oral husk vaccine can be used. 

Because the whole idea of a tiered approach of the kind outlined above is in its initial stages, it will have to be validated and discussed further and will in all probability need to be refined afterwards. The aim here is to introduce the idea of a stepwise approach to the assessment of the risk to re-entry workers. The outlined procedure should be used to calculate the dermal re-entry exposure for real examples of rather dermally toxic compounds in order to gain experience with the recommended procedure. 

During disposal of the tribromide by a recommended procedure involving slow addition to a mixture of soda ash and dry slaked lime, a violent reaction, accompanied by flame, occurred a few seconds after the first drop. Cautious addition of the bromide to a large volume of ice water is suggested for disposal. 

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