Extraneous parts

A protective conductor connecting exposed and extraneous parts together is one definition of ... 

If the installation includes any special facilities such as a test bench where it is necessary to establish and maintain a non-conducting location, the walls and floors must be made of non-conducting material. Their insulation value has to be proved by measuring the leakage current between at least three points on each relevant surface and earth. So a test bench against a wall would require a test at not less than three points on the adjacent wall and three on the floor. If there is an extraneous conductive part in the location, such as a metal window frame or service pipe, one of the test points should be not less than 1 m or more than 1.2 m from it. Check that the extraneous conductive part is separated from any exposed conductive part so that they cannot be touched simultaneously. If they can, the section of the extraneous part, within reach, has to be insulated to withstand a 2 kV a.c. test with a leakage current not exceeding 1 mA. 

Decolorisation by Animal Charcoal. It sometimes hap pens (particularly with aromatic and heterocyclic compounds) that a crude product may contain a coloured impurity, which on recrystallisation dissolves in the boiling solvent, but is then partly occluded by crystals as they form and grow in the cooling solution. Sometimes a very tenacious occlusion may thus occur, and repeated and very wasteful recrystallisation may be necessary to eliminate the impurity. Moreover, the amount of the impurity present may be so small that the melting-point and analytical values of the compound are not sensibly affected, yet the appearance of the sample is ruined. Such impurities can usually be readily removed by boiling the substance in solution with a small quantity of finely powdered animal charcoal for a short time, and then filtering the solution while hot. The animal charcoal adsorbs the coloured impurity, and the filtrate is usually almost free from extraneous colour and deposits therefore pure crystals. This decolorisation by animal charcoal occurs most readily in aqueous solution, but can be performed in almost any organic solvent. Care should be taken not to use an excessive quantity... 

System designers often think dampers bloek airflow and are suitable to prevent baek drafts in idle towers. This is not the ease. Airfoil dampers simply hamper fan housing efficiency- they do not block airflow. Air Inlet Screens are always part of blow through, counterflow towers to protect people from rotating equipment. Some designs can be a hazard when accessible from the underside and require the specifier to call out additional screening. They can be a worthwhile accessory when there are nearby trees even when not required for safety reasons. Air inlet screens should be eliminated on towers utilizing inlet ductwork. Inlet ductwork may also make it necessary to block extraneous air entry such as from the underside when towers are elevated. 

Pilot plant experiments vary over a wide range, aeeounting for industrial eonstraints (e.g., duration of operation, eontrol parameters, equipment reliability, and impurities in the raw materials). Seale-up problems are investigated during pilot plant experiments. A pilot plant is an experimental rig, whieh displays the part of the operation that eorresponds to an industrial plant. It allows for simultaneous analysis of the physieal and ehemieal meehanisms. A pilot plant is indispensable for measuring the extent of the possible interaetions between these two types of meehanisms. It ean be small to minimize extraneous eosts sueh as the total operation eost as well as other eonstraints. 

Steady-state. An erroneous rate law is shown below for the reaction scheme believed to represent the reaction between Fe3+ and I-, in that an extraneous denominator term appears. In the scheme shown, I2 and Fel2+ obey the steady-state approximation. Show what the incorrect part of the expression is. Suggest a simple derivation of the correct equation that avoids extensive algebraic manipulations. 

The properties described above have important consequences for the way in which these skeletal tissues are subsequently preserved, and hence their usefulness or otherwise as recorders of dietary signals. Several points from the discussion above are relevant here. It is useful to ask what are the most important mechanisms or routes for change in buried bones and teeth One could divide these processes into those with simple addition of new non-apatitic material (various minerals such as pyrites, silicates and simple carbonates) in pores and spaces (Hassan and Ortner 1977), and those related to change within the apatite crystals, usually in the form of recrystallization and crystal growth. The first kind of process has severe implications for alteration of bone and dentine, partly because they are porous materials with high surface area initially and because the approximately 20-30% by volume occupied by collagen is subsequently lost by hydrolysis and/or consumption by bacteria and the void filled by new minerals. Enamel is much denser and contains no pores or Haversian canals and there is very, little organic material to lose and replace with extraneous material. Cracks are the only interstices available for deposition of material. 

Some dyes contain a coordinated transition metal as an essential part of their chromogenic structure and this must be left undisturbed by any sequestrant used to complex extraneous metal ions in the system. Hence a balance of properties is needed, phosphates and hydroxycarboxylates being useful. It is claimed that polycarboxylates can be molecularly engineered to give the required balance of properties. 

In the latter case an extraneous messenger has to dock at the receptor s extracellular binding site on the cell surface. The information about the occupancy of the corresponding receptor is transmitted through the transmembrane part of the protein into its cytosolic domains by conformational changes. This structural response can be induced by an additional dimerization and results in a covalent modification of intracellular side chains. The new conformation is then recognized by cytosolic partner molecules. In this connection GTP binding pro-... 

Ideally, the pH range covered by an IEF gel should be centered on the pi of the proteins of interest. This ensures that the proteins of interest focus in the linear part of the gradient with many extraneous proteins excluded from the separation zone. 

CE instruments are thermostated to dissipate excessive Joule heat. Generally that covers only the main part of the capillary, and not, e.g., the autosampler with the buffer and sample vials. In some instruments, it is difficult to control the autosampler temperature due to the near presence of extraneous heating sources such as the detector lamp. Also, some labs... 

EXTRAN is a separation technology designed to continuously clean the fluid in an aqueous parts washer. The technology separates free oil, emulsified oil, and particles from parts washing... 

Boyles view of the atmosphere is fundamentally physical, its composition being a mixture of three kinds of particles. The first came from the many extraneous exhalations from the earth, water, minerals, vegetables, and animals, c, but these made up only a very small part of the atmo-... 

We have seen that Boyle s conception of chemistry was a very mechanical one and this attitude is nowhere more evident than in his view on the composition of the atmosphere. He was much impressed by the presence of many extraneous exhalations from the earth, water, minerals, vegetables, and animals, c, but these made up only a very small part of the atmosphere itself The second sort of particles, even more subtle than the first, consist of the magnetical steams. .. and the innumerable particles of light from the sun and other stars. But the third set of particles are those, which are not only for a while, by manifest outward agents, made elastical, but are permanently so, and on that account may be styled perennial air. 5 In short, Boyles concept of the atmosphere is that of an intrinsically elastic air which carries in it the various steams and smoakes from a variety of sources. It is these adventitious ingredients that are responsible for any seemingly chemical involvement of the atmosphere. For Boyle, the air itself is characterized by its elasticity and has no chemical function. 

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