Aggression

It is noteworthy, however, that traces of sulfur can have beneficial effects on the anti-wear resistance of fuel injection pumps. It is thus undesirable to reduce the sulfur content to extremely low values unless additives having lubricating qualities are added. Independently from total sulfur content, the presence of mercaptans that are particularly aggressive towards certain metal or synthetic parts is strictly controlled. The mercaptan content is thereby limited to 0.002% (20 ppm) maximum. The analysis is performed chemically in accordance to the NF M 07-022 or ASTM D 3227 procedures. 

During take-off and landing, the wheels of modem aircraft are subject to great stress. New high-performance brake systems and aggressive environmental influences push the wheels closer and closer to their limit. These conditions as well as increased requirements for safety and quality control now necessitate that wheels are tested much more comprehensively than in the past. 

Corrosion associated with the action of micro-organisms present in the corrosion system. The biological action of organisms which is responsible for the enliancement of corrosion can be, for instance, to produce aggressive metabolites to render the environment corrosive, or they may be able to participate directly in the electrochemical reactions. In many cases microbial corrosion is closely associated with biofouling, which is caused by the activity of organisms that produce deposits on the metal surface. 

The last example presented in this section deals with the pitting corrosion of Fe in CIO solutions. Perchlorate is less known as an aggressive ion but reveals some unique and remarkable characteristics with regard to pitting corrosion. For example, the critical pitting potential (1.46 V against a standard hydrogen electrode (SHE) for Fe/1 M NaClO ) can be measured with an accuracy of less than 4 mV [61] which is very unexpected if compared to... 

Strehblow FI-FI and Titze B 1977 Pitting potentials and inhibition potentials of iron and nickel for different aggressive and inhibiting anions Corn Scl 17 461-72... 

The reactivity of the halogens decreases m the order F2 > CI2 > Br2 > I2 Fluo rme is an extremely aggressive oxidizing agent and its reaction with alkanes is strongly exothermic and difficult to control Direct fluonnation of alkanes requires special equip ment and techniques is not a reaction of general applicability and will not be discussed further... 

Some scientific studies indicate that the gam in performance obtained through the use of anabolic steroids is small This may be a case though in which the anecdotal evidence of the athletes may be closer to the mark than the scientific studies The scientific studies are done under ethical conditions in which patients are treated with prescription level doses of steroids A 240 pound offensive tackle ( too small by todays standards) may take several ana bolic steroids at a time at 10-20 times their pre scribed doses in order to weigh the 280 pounds he (or his coach) feels is necessary The price athletes pay for gams in size and strength can be enormous This price includes emotional costs (friendships lost because of heightened aggressiveness) sterility testicular atro phy (the testes cease to function once the body starts to obtain a sufficient supply of testosterone like steroids from outside) and increased risk of prema ture death from liver cancer or heart disease... 

Microbial leaching of metals from ores is a promising adjunct to more aggressive metal recovery technologies (77), but is generally achieved by oxidative processes that generate very acidic waters. It seems unlikely that similar approaches will be of much value in removing contaminant metals and metalloids from soils. 

Pressure-Sensitive Adhesives. A pressure-sensitive adhesive, a material which adheres with no more than appHed finger pressure, is aggressively and permanently tacky. It requkes no activation other than the finger pressure, exerts a strong holding force, and should be removeable from a smooth surface without leaving a residue. 

Aluminum. Some manufacturers also have WORM disks above 5.25 in. on offer with aluminum as substrate material. Eor A1 the same advantages apply as for glass with the exception of a high coefficient of thermal expansion and lacking resistance to aggressive chemical vapors and Hquids. 

The molten carbonate fuel ceU uses eutectic blends of Hthium and potassium carbonates as the electrolyte. A special grade of Hthium carbonate is used in treatment of affective mental (mood) disorders, including clinical depression and bipolar disorders. Lithium has also been evaluated in treatment of schizophrenia, schizoaffective disorders, alcoholism, and periodic aggressive behavior (56). 

Plate-and-frame systems are competitive in this appHcation despite their high cost, primarily because they can be operated at high temperatures with relatively aggressive feed solutions, for which spiral-wound modules might fad. 

The composition of the builders in an alkaline cleaner is dependent on the metal substrate from which the soil is to be removed. For steel (qv) or stainless steel aggressive, ie, high pH, alkaline salts such as sodium or potassium hydroxide can be used as the main alkaline builder. For aluminum, zinc, brass, or tin plate, less aggressive (lower pH) builders such as sodium or potassium siUcates, mono- and diphosphates, borates, and bicarbonates are used. 

Equipment for storing and handling methanol may be made of carbon or stainless steel. Methanol is aggressive toward copper, zinc, magnesium, tin, lead, and alurninum, which should therefore be avoided. Gasket materials must also be chosen carefiiUy, because some elastomers swell and deteriorate when exposed to methanol. Similarly, the use of plastics for storage is not recommended. 

A key feature of encapsulation processes (Figs. 4a and 5) is that the reagents for the interfacial polymerisation reaction responsible for shell formation are present in two mutually immiscible Hquids. They must diffuse to the interface in order to react. Once reaction is initiated, the capsule shell that forms becomes a barrier to diffusion and ultimately begins to limit the rate of the interfacial polymerisation reaction. This, in turn, influences morphology and uniformity of thickness of the capsule shell. Kinetic analyses of the process have been pubHshed (12). A drawback to the technology for some apphcations is that aggressive or highly reactive molecules must be dissolved in the core material in order to produce microcapsules. Such molecules can react with sensitive core materials. 

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