External softening

Docusate calcium is used both as a fecal softening agent and an emulsifier, ie, a wetting or dispersing agent for external preparations (see Emulsions). 

Plastic Pipe In contrast to other piping materials, plastic pipe is free from internal and external corrosion, is easily cut and joined, and does not cause galvanic corrosion when coupled to other materials. Allowable stresses and upper temperature limits are low. Normal operation is in the creep range. Fluids for which a plastic is not suited penetrate and soften it rather than dissolve surface layers. Coefficients... 

The first tank was cleaned without incident. By the time the contractors started on the second tank, a new foreman was in charge. To soften the deposits, he disconnected the steam coil, blew live steam into the tank, and then sprayed kerosene onto the walls, section by section, using a spinner mounted on a tripod. The report does not make it clear whether or not the kerosene was heated. While men were moving the tripod, a fire started in the tank, followed by an explosion. Three men were icilled. one by the fire and tw o by falling bits of the external concrete cladding. 

Where the feed contains a large proportion of treated water, softening is a minimum requirement and the raw water quality dictates whether a more sophisticated form of external treatment would be preferable. If the water has a high alkalinity it calls for de-alkalization and base exchange. De-ionization is the ideal water treatment, but is usually avoided if possible because of its cost and use of corrosive chemicals. Membrane processes giving partial de-ionization are not normally installed at present, but are certain to become important in the future. 

It is particularly important to avoid waters which are inherently acidic or those which might become so in operation, e.g. those containing the chlorides of magnesium or, to a lesser extent, calcium, which undergo hydrolysis at elevated temperatures. This can be done either by removing such salts externally in a softener or by dosing enough alkali into the system to neutralise the acidity produced. 

NOTE Almost all types of commercial or industrial boilers, of whatever type, size, and application, must be provided with fully softened FW as an absolute minimum form of external water treatment. This requirement includes electrical resistance boilers. Probable exceptions to this rule are HW heating boilers and steam boilers operating at below 15 psig and receiving in excess of 95% returned condensate. 

A lack of much-needed MU water softening, dealkalization, or similar external treatment capability is quite common in many small to midsized industrial facilities. It seldom produces a complete boiler failure or anything quite so dramatic, but it is nonetheless very costly in terms of additional fuel costs and maintenance. Personnel may learn to live with the resultant poor quality of FW for many years, accepting the position as normal until the facts are pointed out and alternative proposals are considered. 

External treatment also meant the removal of calcium and magnesium hardness by zeolite softening using either a variety of silcate-based, natural zeolites [such as analcite, (Na AljS O, 2 2H20)], or manufactured carbon zeolites. 

Emollient. Used externally to soothe, soften and protect the skin, elder makes an excellent ointment for burns, sores and hemorrhoids. Parts used flowers, inner bark, leaves. 

Ointments are semisolid preparations to be applied externally to the skin or mucous membranes they soften or melt at room temperature. Pastes are thick, stiff ointments... 

Far below the glass transition temperature (T see Sect. 2.3.4.3) the macro-Brownian motions are frozen in completely, and most of the micro-Brownian motions are frozen in as well ( glassy state ). Near Tg, the micro-Brownian motions set in and become stronger with increasing temperature. The material softens. Finally, upon further raise of temperature, the macro-Brownian motions set in as well, and the polymer can be deformed by applying an external force. 

Description and Properties. — Ammoniac is found in tears and drops, sometimes distinct, but more generally in agglutinated masses. Externally the tears ore yellow, with a tinge of brown, with a waxy lustre internally they are whits or cream-colored, and opaque. It is moderately hard, and at ordinary temperatures brittle, but softens like wax with the heat of the hood. It hoe a faint and somewhat unpleasant, but very peculiar odor, best detected by subjecting it te heat j its teste is bitter and nauseous. 

Internally plasticized systems consisting of simple random copolymers, designed for use in flexible plastic articles, generally have an unsatisfactorily narrow use temperature range, since they soften more sharply than analogous externally plasticized systems or polyblends (mixtures of two or more polymers). 

Potassium, sodium and calcium sulphides are applied externally to soften the skin by dissolving the epidermis in diseases such as psoriasis, acne and seborrhea. Mixtures of calcium or potassium polysulphides and thiosulphate behave similarly and are also depilatories. Another common hair remover is barium sulphide, mixed with starch or zinc oxide, whereas selenium suphide and cadmium sulphide are applied topically, in shampoos, to control dandruff. 

Concerning the first step of coating, when the particles of polyolefin are introduced into the bed, their external surface becomes softer but their inside is cold, due to their low thermal conductivity. The softened surface is responsible for the formation of agglomerate made up of a plastic particle surrounded by sand particles. When the whole plastic particle... 

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