Special resists

The shipment of many commodities may require special barriers on the sacks to impart resistance against hquids or vapors. Other treatments are used to provide grease resistance, acid resistance, and scuff resistance. Special coatings are used in sacks for packing commodities, eg, synthetic mbbers, asphalts, waxes (qv), and resins, to prevent the contents from sticking to the paper. 

Improved steam and base resistance. Special grades requited. 

Anode supports, cable insulators and the coating on the object to be protected can be destroyed by anodic evolution of chlorine (see Section 7.1), Only chorine-resistant materials should be used. Anodes on retaining walls or between pile foundations can be installed in perforated or fabricated plastic tubes (half-shells) (see Fig. 16-8). They must naturally be provided with very many holes to avoid uneven removal of anode material. Filter tubes of a chlorine-resistant special material or... 

Type of binder Mode of drying Solvents Acid resistance Alkali resistance Water resistance Solvent resistance Exterior weathering resistance Special features... 

Polyamide-imides are good insulators even in hot environments, with high dielectric resistivities. Special grades are marketed for electrical applications. 

Change of resistance Special sensor3) 0- 8 Max. 0.3 % of span < 0.5% Proved standard method, Types of devices PMP731, PMD235 3) [54], type HP-1 [581... 

Slack, Henry. "Corrections for Shell-Side Head Loss Resistance." Special Project, GA Tech, M.E., 1980. 

While rubber shows excellent wear properties in the friction induced abrasion range of 0-5 0 impact angle, in the 5 - 50 0 impact range it tends to be mechanically damaged by impact. So the angle of incidence of the medium has a significant influence on the wear resistance. Special ribbed surfaces of the rubber improve the wear resistance in such cases, see Figure 4.1. 

Closure systems are becoming more complex and sophisticated, incorporating features related to such aspects as tamper-evidence, tamper-resistance, child-resistance, special easy opening closures for the elderly, and product administration. 

Resistive materials used in thermometry include platinum, copper, nickel, rhodium-iron, and certain semiconductors known as thermistors. Sensors made from platinum wires are called platinum resistance thermometers (PRTs) and, though expensive, are widely used. They have excellent stability and the potential for high-precision measurement. The temperature range of operation is from -260 to 1000°C. Other resistance thermometers are less expensive than PRTs and are useful in certain situations. Copper has a fairly linear resistance-temperature relationship, but its upper temperature limit is only about 150°C, and because of its low resistance, special measurements may be required. Nickel has an upper temperature limit of about 300°C, but it oxidizes easily at high temperature and is quite nonlinear. Rhodium-iron resistors are used in cryogenic temperature measurements below the range of platinum resistors [11]. Generally, these materials (except thermistors) have a positive temperature coefficient of resistance—the resistance increases with temperature. 

Tantalum rarely used due to high price corrosion-resistant special components... 

Titanium corrosion-resistent special apparatus (nitric acid, hot lower carboxylic acids)... 

Material welded construction, cast steel, cast steel with wear-resistant rims, Nihard, highly wear-resistant special casting, hard-faced augers, stainless steel design ... 

Kevlar fibers are temperature-resistant special fibers used, for instance, in bulletproof vests. The main application of Kevlar is, however, as a reinforcing fiber in composites. One drawback here is the lack of compression strength of the fibers, presumably due at least in part to the mantle-core structures produced by spinning from sulfuric acid solutions. Helical kink band defects appear when Kevlar is compressed. Composites with Kevlar as a reinforcing fiber therefore do not fail due to rupturing of the fibers or matrix, but rather due to an elastic fault caused by shearing forces. 

Since the advent of penicillin, p-lactam antibiotics have occupied a central role against pathogenic bacteria. Moreover, more and more novel p-lactam antibiotics (Figure 4.3) have been developed due to bacterial tolerance and resistance. Special impetus for research efforts on p-lactam chemistry has been provided by the introduction of the p-lactam synthon method, a term coined by Ojima over 15 years ago, according to which 2-azetidinones can be employed as useful intermediates in organic synthesis. 

Eyewitness testimony was also important, and the State Department tried to confirm its veracity wherever possible. Evans s book only refers to the testimony of the H Mong but the Haig report stresses that in all three countries instances were identified in which eyewitness accounts could be correlated with information from other sources . Aware of the propaganda activities of Pol Pot s Democratic Kampuchean resistance, special efforts were made to confirm any Kampuchean allegations. Several anthropologists who have worked... 

The four-probe resistivity meter or Wenner probe was developed for measuring soil resistivity. Specialized modification. of the Wenner probe are frequently used for measurement of concrete resistivity on site. The measurement can be used to indicate the possible corrosion activity if steel is depassivated. Proprietary versions of the system are shown in Figures 4.10(a) and 4.10(b) and a schematic given in Figure 4.in(d). Current is applied between the two outer probes and the potential difference measured across the two inner probes. This approach eliminates any effects due to surface contact resistances. 

An extremely large number of phenolic materials are available based on the many resin and filler combinations, and they can be classified in many ways. One common way of classifying them is by type of application or grade. The major grades are general purpose, impact resistant, electrical, heat resistant, special purpose, and chemical resistant. 

ABS Inexpensive Excellent impact behaviour Good dimensional stability Good stiffness Good solvent resistance Special high butadiene content grade needed for maximum impact... 

Mechanical resistance Special provision often necessary to enhance fatigue resistance Fairly good resistance to vibration Special provision for fatigue and resistance to loosening at joints Excellent fatigue properties. Electrical resistance reduces corrosion... 

NllO, N121 Very high abrasion resistance Special tire treads, airplane, off-the-road racing... 

For special requirements in which the EPDM seals are not resistant, special sealing collars of NBR (based on nitrUe mbber) are used. Sealing collars made of fluori-nated mbber are also possible however, they are very expensive. 

Roth, P. (1992), Corrosion-resistant special steels for flue gas desulfurization plants, Werkstoffe Korrosion 43, 275-279. 

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