System classification

Possibility of unexpected events in data. Unless the inspection occurs in well controlled environment, there is always a possibility of occurrence of unexpected events in data. These can be caused e.g. by previously unseen type of damage. Amount of unexpected data is reduced if inspection is done periodically. An experienced operator can usually correctly interpret unexpected data, but some automatic classification systems may fail and raisclassify the data. 

Neural network classifiers. The neural network or other statistical classifiers impose strong requirements on the data and the inspection, however, when these are fulfilled then good fully automatic classification systems can be developed within a short period of time. This is for example the case if the inspection is a part of a manufacturing process, where the inspected pieces and the possible defect mechanisms are well known and the whole NDT inspection is done in repeatable conditions. In such cases it is possible to collect (or manufacture) as set of defect pieces, which can be used to obtain a training set. There are some commercially available tools (like ICEPAK [Chan, et al., 1988]) which can construct classifiers without any a-priori information, based only on the training sets of data. One has, however, always to remember about the limitations of this technique, otherwise serious misclassifications may go unnoticed. 

The combination of contrast and granularity produces a signal to noise ratio which allows for direct comparison of various films. The classes have minimum values for eontrast and maximum values for graininess. The ASTM classification system employs the same parameters as the European Standard EN584-1 and ISO CD (see Table 1). 

Some U.S. governmental lubricant requirements for nontactical equipment is now acquired as Commercial Item Descriptions (CID), rather than against specific military numbers. A new classification system for shear-stable, high VI hydraulic fluids was balloted by ASTM in 1994. 

The lanthanides are considered only slightly toxic in the Hodge-Stemer classification system and are safely handled with ordinary care (15). Inhalation of rare-earth vapors or dust should be avoided, and the skin washed thoroughly if it comes into contact with any dust or solution. 

Viscosity Glassifications. The general ISO iatemational viscosity classification system for iadustrial oils is given ia Table 4 from ASTM D2422 (American National Standard Z11.232). For high speed machines, ISO viscosity-grade 32 turbiae and hydrauHc oils are a common choice. ISO grades 68 and 100 are appHed for more load capacity ia slower speed machines where power loss and temperature rise are less of a question. 

Glassification of Substance-Related Disorders. The DSM-IV classification system (1) divides substance-related disorders into two categories (/) substance use disorders, ie, abuse and dependence and (2) substance-induced disorders, intoxication, withdrawal, delirium, persisting dementia, persisting amnestic disorder, psychotic disorder, mood disorder, anxiety disorder, sexual dysfunction, and sleep disorder. The different classes of substances addressed herein are alcohol, amphetamines, caffeine, caimabis, cocaine, hallucinogens, inhalants, nicotine, opioids, phencyclidine, sedatives, hypnotics or anxiolytics, polysubstance, and others. On the basis of their significant socioeconomic impact, alcohol, nicotine, cocaine, and opioids have been selected for discussion herein. 

Fig. 1. SAE J200 Classification system for ASTM No. 3 oil where in volume swell nr = no requirement. EPDM is ethylene—propylene—diene monomer HR, butyl mbber SBR, styrene—butadiene mbber NR, natural mbber VMQ, methyl vinyl siUcone CR, chloroprene FKM, fluoroelastomer FVMQ, fluorovinyl methyl siUcone ACM, acryUc elastomers HSN, hydrogenated nitrile ECO, epichlorohydrin and NBR, nitrile mbber.

Table 9 shows the classification system for blacks most commonly used in mbber. The ASTM numbering system is based on the fundamental particle si2e of the black. Particle si2e is deterrnined by several methods, including iodine absorption, nitrogen absorption, and light scattering. 

ASTM number Average particle si2e, nm Old classification system... 

The pneumatic classification system should be designed to handle ha2ardous dust (28). A ha2ardous dust is one which, when finely divided and suspended in air in the proper concentration, bums, produces violent explosions, or is sufficiently toxic to be injurious to personnel health (see Air pollution control methods Powders, handling). At the least, almost any dust can be irritating to personnel because of inhalation or skin or eye contact. Fully oxidi2ed and hydrated materials are generally considered safe. 

Gas-phase separations may be classified as enrichment, sharp, or purification separation, depending on the purity, recovery, and magnitude of the pertinent separation. The classification system allows for a certain amount of synergy, as several separation methods may be combined in order to achieve the desired result. Certain separation methods ate favored for each category (26). 

There are at least four different classification systems for cemented carbides (7,12). The U.S. system is based on relative performance the U.K. system is based on properties, and the former USSR system on composition the fourth system, widely used in Europe and supported by the ISO, is based on apphcation and chip form. In this article, the U.S. system and the ISO system are briefly reviewed. 

A paraffin wax is a petroleum wax consisting principally of normal alkanes. MicrocrystalHne wax is a petroleum wax containing substantial proportions of branched and cycHc saturated hydrocarbons, in addition to normal alkanes. SernimicrocrystaUine wax contains more branched and cycHc compounds than paraffin wax, but less than microcrystalHne. A classification system based on the refractive index of the wax and its congealing point as... 

Prior to the nineteenth century, coal was classified according to appearance, eg, bright coal, black coal, or brown coal. A number of classification systems have since been developed. These may be divided into two types, which are complementary scientific and commercial. Both are used in research, whereas the commercial classification is essential industrially. In the scientific category, the Seyler chart has considerable value. 

The ASTM Glassification. The ASTM classification system was adopted in 1938 as a standard means of specification. This system is used in the United States and in many other parts of the world, and is designated D388 in the ASTM Standards (18). The higher rank coals are specified by fixed carbon >69%, or for volatile matter <31%, on a dry, mineral-free basis. Lower rank coals are classified by calorific value on the moist, mineral-matter-free... 

Fig. 7. Coal classification system according to Hofmann where A = Eu plastic B = plastic C = Per plastic and D = Fluido plastic.

Adsorption of dispersants at the soHd—Hquid interface from solution is normally measured by changes in the concentration of the dispersant after adsorption has occurred, and plotted as an adsorption isotherm. A classification system of adsorption isotherms has been developed to identify the mechanisms that may be operating, such as monolayer vs multilayer adsorption, and chemisorption vs physical adsorption (8). For moderate to high mol wt polymeric dispersants, the low energy (equiUbrium) configurations of the adsorbed layer are typically about 3—30 nm thick. Normally, the adsorption is monolayer, since the thickness of the first layer significantly reduces attraction for a second layer, unless the polymer is very low mol wt or adsorbs by being nearly immiscible with the solvent. 

Title I allows the EPA to define the boundaries of "nonattainment" areas for ozone, CO, and PMjg. Emission standards for these areas will be based on a new set of "nonattainment categories." EPA has established a classification system for ozone design values (goals) and attainment deadlines. Table 24-2 lists these parameters. 

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