Minerals major classes

In the previous paragraph, it has been stated that minerals have the same structure but different compositions (phenomenon of isomorphism of minerals) while some minerals have the same composition but different structures (phenomenon of polymorphism of minerals). Mineral composition and structure are both important in studying and classifying minerals. The major class of minerals - based on composition and structure - include elements, sulfides, halides, carbonates, sulfates, oxides, phosphates, and silicates. The silicate class is especially important, because silicon makes up 95% of the minerals, by volume, in the Earth s crust. Mineral classes are divided into families on the basis of the chemicals in each mineral. Families, in turn, are made of groups of minerals that have a similar structure. Groups are further divided into species. 

There are several chemical compounds found in the waste waters of a wide variety of industries that must be removed because of the danger they represent to human health. Among the major classes of contaminants, several aromatic molecules, including phenols and aromatic amines, have been reported. Enzymatic treatment has been proposed by many researchers as an alternative to conventional methods. In this respect, PX has the ability to coprecipitate certain difficult-to-remove contaminants by inducing the formation of mixed polymers that behave similarly to the polymeric products of easily removable contaminants. Thus, several types of PX, including HRP C, LiP, and a number of other PXs from different sources, have been used for treatment of aqueous aromatic contaminants and decolorization of dyes. Thus, LiP was shown to mineralize a variety of recalcitrant aromatic compounds and to oxidize a number of polycyclic aromatic and phenolic compounds. Furthermore, MnP and a microbial PX from Coprinus macrorhizus have also been observed to catalyze the oxidation of several monoaromatic phenols and aromatic dyes (Hamid and Khalil-ur-Rehman 2009). 

Pesticides are chemicals or biological substances used to kill or control pests. They fall into three major classes insecticides, fungicides, and herbicides (or weed killers). There are also rodenticides (for control of vertebrate pests), nematicides (to kill eelworms, etc.), molluscicides (to kill slugs and snails), and acaricides (to kill mites). These chemicals are typically manmade synthetic organic compounds, but there are exceptions which occur naturally that are plant derivatives or naturally occurring inorganic minerals. 

These divisions may each involve several sorption mechanisms, but if they yield a local reaction that can be accurately described with an appropriate isotherm model, they can be incorporated in equation 2. The behavior and resulting local isotherm forms for three major classes of reactions will be examined here sorption by evolutionally immature soil organic matter sorption by natural mineral phases and sorption by diagenetically altered and evolutionally mature organic matter. 

The next major class of flame retardant additives that are nonhalogenated is the phosphorus-based flame retardants, but even these materials have some regulatory environmental concerns.Other nonhalogenated flame retardants that are not phosphorus-based exist, including mineral fillers (i.e., Al(OH)3, Mg(OH)2), expandable graphite, mela-mine, and polymer nanocomposites combined with other flame retardants.Each of these materials has its own advantages and disadvantages, and effectiveness in one polymer system often does not translate into another system. 

Bituminous coatings can be divided into two major classes by application characteristics hot applied and cold applied. The hot-applied coatings can be subdivided by composition nonfilled and filled (usually finely divided mineral). The cold-applied... 

Biopesticides are substances that are derived from such natural materials as animals, plants, bacteria, and certain minerals. For example, canola oil and baking soda have pesticidal applications and are considered biopesticides. Biopesticides fall into three major classes, including microbial pesticides, plant-incorporated protectants, and biochemical pesticides. Microbial pesticides contain microorganisms, such as bacteria, fungi, and viruses, as their active ingredient. The most widely used microbial pesticides are strains of Bacillus thuringiensis, or Bt. Plant-incorporated protectants are pesticidal substances that plants produce from genetic material that has been added... 

Finally, the so-called fillers constitute the last group of additives, which are, as a rule, inert and do not react in cement paste. The hmestone, added on a laige scale in Italy and in France was classified to this group a time ago [3]. As it is commonly known, the hmestone cannot be considered as an inert concrete component however, as compared with mineral additions from the former two groups, degree of CaCOj reaction in cement paste is rather poor. Nowadays, however, hmestones are recommended in the EN 197-1 standard as mineral additions, together with pozzolanic additives (see types of cements. Table 1.3). In 2007 the ratio of limestone cements produced in Europe and Turkey was 21.4 % (members of Cembureau) this corresponded to the annual output on the level of 56.2 million tons, in majority class 42.5. The ground quartz sand can be considered as typical filler, which does not react practically with calcium ions in cement paste, at ambient temperature. 

Three major types of rocks are found in Earth s crust igneous rocks, formed by solidification of molten rock (e.g., basalt) sedimentary rocks (e.g., sandstone, which is cemented sand), formed by deposition of dissolved or suspended substances from oceans and rivers and metamorphic rocks (e.g., marble), formed by the action of heat and pressure on existing rocks. Figure 18.2 gives the average composition of Earth s crust. The most abundant substances in rocks are silicates, which are composed of silicon, oxygen, and positive metal ions (Section 18.5). The more than 2000 kinds of known minerals fall into a few major classes (Table 18.1). 

Silicon being the second most abundant element in Earth s crust, it is no surprise that most minerals are based on this element. There are several major classes of silicate-based minerals, including quartz (which is considered in Chapter 9), simple silicates, and more complex compounds. The largest and more important class is constituted by those which can be grouped, in a general way, as aluminosilicates, comprising many types of structures, including both primary and secondary minerals. 

Almost every major class of organic or halo-organic water contaminants has now been examined, at least initially, for the possible degradation ( partial or to complete mineralization) or removal from the liquid phase (see ref.[14] and [29] for an exhaustive... 

Zinc homeostasis and action involve an intimate association of the mineral with proteins. These proteins include membrane transporters responsible for the absorption of zinc in the gut and its passage into and out of cells and subcellular organelles, transport and delivery proteins (both in the circulation and within cells), sensing proteins that will adjust homeostasis and function according to zinc availability, and a large range of proteins to which zinc is ultimately delivered. Two major classes of these latter proteins are the enzymes and transcription factors. In addition to its association with proteins, zinc within cells is also found associated with membrane lipids and both DNA and RNA. The functions of these pools of zinc are not clear. 

This toxicological profile discusses only three classes of hydraulic fluids mineral oil hydraulic fluids, polyalphaolefin hydraulic fluids, and organophosphate ester hydraulic fluids. The classes are based on the major chemicals found in the hydraulic fluids. However, hydraulic fluids are often complex mixtures of many chemical components. A particular hydraulic fluid can differ in... 

Mineral oil is the major chemical component of mineral oil hydraulic fluids. Mineral oil belongs to a larger class of chemicals called petroleum distillates. The Occupational Safety and Health Administration (OSHA) regulates petroleum distillate and mineral oil mist levels in workplace air. The occupational exposure limits for an 8-hour workday, 40-hour workweek are 2,000 milligrams per cubic meter (mg/m3) in air for petroleum distillates and 5 mg/m3 for mineral oil mists. The National Institute for Occupational Safety and Health (NIOSH) recommends an exposure limit of 350 mg/m3 of petroleum distillates for a 10-hour workday, 40-hour workweek. 

No studies were located that examined the toxicokinetics of mineral oil, organophosphate ester, or polyalphaolefin hydraulic fluids in humans or animals, with the exception of a study examining absorption in rats after exposure to a hydraulic fluid containing 99.9% cyclotriphosphazene (Kinkead and Bashe 1987) and the absorption and metabolism of Reolube HYD46, another organophosphate hydraulic fluid (Ciba-Geigy 1985). This section, therefore, discusses available information on the toxicokinetics of major components of these classes of hydraulic fluids or of materials that maybe expected to display similar toxicokinetic properties based on similar physical and chemical characteristics. It should be emphasized that many hydraulic fluids are complex mixtures of chemicals that may include some chemicals which may not share toxicokinetic properties with the major components. 

Experiments with monkeys given intramuscular injections of a mineral oil emulsion with [l-14C] -hexa-decane tracer provide data illustrating that absorbed C-16 hydrocarbon (a major component of liquid petrolatum) is slowly metabolized to various classes of lipids (Bollinger 1970). Two days after injection, substantial portions of the radioactivity recovered in liver (30%), fat (42%), kidney (74%), spleen (81%), and ovary (90%) were unmetabolized -hexadecane. The remainder of the radioactivity was found as phospholipids, free fatty acids, triglycerides, and sterol esters. Essentially no radioactivity was found in the water-soluble or residue fractions. One or three months after injection, radioactivity still was detected only in the fat-soluble fractions of the various organs, but 80-98% of the detected radioactivity was found in non-hydrocarbon lipids. 

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