Engineering Purposes

D801 soil and rock for engineering purposes D2113, D420, E311... 

Using equation 3, the viscosity of any pitch can be calculated from two measurements in the range of 10 —10 mPa-s(=cP), exhibiting a precision similar to what may be expected of direct measuremeat. By employing equatioas 3, 4 or 5, and 6, the viscosity of pitch at any temperature can be calculated, with an accuracy adequate for most engineering purposes, from the R-and-B softening poiat and the Tl content. 

Rhodium. Rhodium is the most commonly plated platinum-group metal. In addition to its decorative uses, rhodium has useful properties for engineering appHcations. It has good corrosion resistance, stable electtical contact resistance, wear resistance, heat resistance, and good reflectivity. The use of rhodium for engineering purposes is covered by an ASTM specification (128). Typical formulas are shown in Table 15. The metal content is obtained from prepared solutions available from proptietary plating supply companies. Replenishment is requited because anodes are not soluble. Rhodium for decorative use may be 0.05—0.13 p.m thick for industtial use, it maybe 0.50—5.0 p.m thick. 

Commonly accepted practice restricts the term to plastics that serve engineering purposes and can be processed and reprocessed by injection and extmsion methods. This excludes the so-called specialty plastics, eg, fluorocarbon polymers and infusible film products such as Kapton and Updex polyimide film, and thermosets including phenoHcs, epoxies, urea—formaldehydes, and sdicones, some of which have been termed engineering plastics by other authors (4) (see Elastol rs, synthetic-fluorocarbon elastol rs Eluorine compounds, organic-tdtrafluoroethylenecopolyt rs with ethylene Phenolic resins Epoxy resins Amino resins and plastics). 

The local-composition models have hmited flexibility in the fitting of data, but they are adequate for most engineering purposes. Moreover, they are implicitly generalizable to multicomponent systems without the introduction of any parameters beyond those required to describe the constituent binaiy systems. For example, the Wilson equation for multicomponent systems is written ... 

The fliix density to a small area of interest on the envelope of an emitter volume of any shape can be matched by that at the base of a hemispherical volume of some radius L, which is called the mean beam length. It is found that although the ratio of E to a characteristic dimension D of the shape varies with opacity, the variation is small enough for most engineering purposes to permit use of a constant ratio... 

In any event, the users of the mixer can issue a mechanical specification aud determine the speed, diameter of an impeller, aud power with in-house expertise. Or they may issue a processes specification which describes the engineering purpose of the mixing operation and the vendor will supply a description of the mixer process performance as well as prepare a mechanical design. 

Assuming that natural gas is used to fire the burner with a known heating value of HVc, calculate the available heat at the operating temperature. A shortcut method usually used for most engineering purposes is ... 

For practical engineering purposes, relative density at 15°C (288 K), widely used in countries outside the United States, is considered equivalent to specific gravity at 60°F (288.6 K). With the adoption of SI units, the American Petroleum Institute favors absolute density at 288 K instead of degrees API. 

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... 

BS 970 1991 Part 3 - Specification for Wrought Steels for Mechanical and Allied Engineering Purposes. London BSI. 

The reluctance of acrylic monomers to polymerise in the presence of air has been made a virtue with the anaerobic acrylic adhesives. These are usually dimethacrylates such as tetramethylene glycol dimethacrylate. The monomers are supplied with a curing system comprising a peroxide and an amine as part of a one-part pack. When the adhesive is placed between mild steel surfaces air is excluded, which prevents air inhibition, and the iron present acts as a polymerisation promoter. The effectiveness as a promoter varies from one metal to another and it may be necessary to use a primer such as cobalt naphthenate. The anaerobic adhesives have been widely used for sealing nuts and bolts and for a variety of engineering purposes. Small tube containers are also available for domestic use. 

There is little call for these thermoplastics materials (marketed as Durethan U, Farbenfabriken Bayer) since they are about twice the price of nylons 66 and 6. Where a thermoplastic for light engineering purposes is required with a low water absorption, nylon 11, acetal resins and, in certain instances, polycarbonates are cheaper and, usually, at least as satisfactory. 

BS4641 Electroplated Coatings of Chromium for Engineering Purposes. ... 

The heal of reaction (see Section 4.4) is defined as tlie enthalpy change of a system undergoing chemical reaction. If the retictants and products are at tlie same temperature and in their standard states, tlie heat of reaction is temied tlie standard lieat of reaction. For engineering purposes, the standard state of a chemical may be taken as tlie pure chemical at I atm pressure. Heat of reaction data for many reactions is available in tlie literature. ... 

Polycarbonates (PC) are another group of condensation thermoplastics used mainly for special engineering purposes. These polymers are considered polyesters of carbonic acid. They are produced by the condensation of the sodium salt of bisphenol A with phosgene in the presence of an organic solvent. Sodium chloride is precipitated, and the solvent is removed by distillation ... 

For engineering purposes the composition of fresh air is generally taken at the following standard conditions ... 

Dalton s Faw has been proved experimentally to be somewhat inaccurate, the total pressure often being higher than the sum of the partial pressures. This is especially true during transitions as pressure is increased. However, for engineering purposes it is the best rule available and the error is minor. 

If it is necessary for engineering purposes to know the tonal make-up of a noise, several approaches are possible. A bandpass filter can process the noise. The most common filters are octave band filters, and the agreed center frequencies are as follows ... 

Table 4.1 Some wrought British Standard aluminium alloys for general engineering purposes (non-heat treatable alloys)...

For engineering purposes magnesium is rarely used in the unalloyed condition. Small percentages of aluminium, zinc, etc. as indicated in Table 4.15 are added to improve mechanical and other properties. Magnesium is itself used for alloying with other metals. 

BS 2816 Electroplated Coatings of Silver for Engineering Purposes BS 3382 Electroplated Coatings on Threaded Components ... 

Hard Anodic Oxide Coatings on Aluminium for Engineering Purposes, British Standard 5599 1978... 

A number of standards exist for the determination of some of these parameters. BS 1377 Part 3 1990 refers to methods of tests for soils for civil engineering purposes, and Part 9 refers to these and corrosivity tests in situ. It is significant that the standard draws attention to the fact that the results of the tests that are described should be interpreted by a specialist. ASTM tests for pH and resistivity of soil used for corrosion testing are covered by G51 1977(R1984) and G57 1978 (R1984), respectively. 

Many gases at low pressure, i.e. atmospheric pressure and below for water vapour and up to several bar for gases such as nitrogen, oxygen and argon, obey simple relations between their pressure, volume and temperature, with sufficient accuracy for engineering purposes. Such gases are called ideal . 

It is easily possible to introduce refinements into the dilated van Laar model which would further increase its accuracy for correlating activity coefficient data. However, such refinements unavoidably introduce additional adjustable parameters. Since typical experimental results of high-pressure vapor-liquid equilibria at any one temperature seldom justify more than two adjustable parameters (in addition to Henry s constant), it is probably not useful for engineering purposes to refine Chueh s model further, at least not for nonpolar or slightly polar systems. 

This section considers three special cases. The first is a flat velocity profile that can result from an extreme form of fluid rheology. The second is a linear profile that results from relative motion between adjacent solid surfaces. The third special case is for motionless mixers where the velocity profile is very complex, but its net effects can sometimes be approximated for reaction engineering purposes. 

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