Ultra Low

Relatively smaller amounts of very high purity A1F. are used ia ultra low loss optical fiber—duotide glass compositions, the most common of which is ZBLAN containing tirconium, barium, lanthanum, aluminum, and sodium (see Fiber optics). High purity A1F. is also used ia the manufacture of aluminum siUcate fiber and ia ceramics for electrical resistors (see Ceramics AS electrical materials Refractory fibers). 

Low Cement, Ultra-Low Cement, and No-Cement Castables are classified on the basis of calcium oxide content. These are 1—2.5, 0.2—1.0, and 0.2% CaO maximum, respectively. In the latter case the lime content is not a result of a hydrauHc setting cement constituent but comes from aggregate impurities. The insulating class is also subdivided. This division is shown in Table 14. Refractories used in steel-pouring pits are classified under ASTM C435 (Table 15). 

P. Dunlop and co-workers, "Aqueous Surfactant Solutions Which Exhibit Ultra-Low Tensions at the Oil-Water Interface," Paper presented at the... 

Dutta, P., Cowell, L.H., Yee, D.K., and Dalla Betta, R.A., Design and Evaluation of a Single-Can Full Scale Catalytic Combustion System for Ultra-Low Emissions Industrial Gas Turbines, ASME 97-GT-292. 

Reneganathan, K., Zondlo, J. W., Mintz, E. A., Kneisl, P., and Stiller, A. H., Preparation of an ultra-low ash coal extract under mild conditions. Fuel Processing Technology, 1988, 18, 273 278. 

Tioxide process. This process is similar to that used to produce fumed silicas. Ultra-low particle size titanium dioxide (15-35 nm) is obtained for use as photocatalyst or UV absorber (for instance in sun protective creams). 

Another common device used in the rubber industry is the thin film evaporator. This device is very often used in the manufacture of ultra-low molecular weight elastomers that are used in sealant applications or specialty coatings, and as processing aids in conventional rubber compounding processes. The thin film evaporator described earlier, has found a multitude of other industry applications, including food processing operations. 

Ultra-low-penetration air filter (ULPA) A filter that has a... 

Almost all the major car, bus, and truck manufacturers have developed compressed natural gas engines and vehicles. These manufacturers have been able to offer better performance (due to higher octane) and far lower emissions of nitrogen oxides, carbon monoxide, particulate matter, and carbon dioxide to the atmosphere. In 1998, Honda introduced the cleanest internal combustion engine vehicle ever commercially produced the natural gas Civic GX with emissions at one-tenth the state of California s Ultra Low Emission Vehicle standard. Primarily due to the high octane of natural gas, Honda achieved these results without sacrificing performance. 

A large variety of oils is available, and recommendations for any set of conditions, compressor type and refrigerant can be obtained from the refiners. They are naphthene or paraffin-based oils. Synthetic lubricants have been developed for ultra-low-and high-temperature systems, especially for process heat pumps. 

SRI Standards Research Institute ULDPE ultra low density polyethylene... 

This statement is supported by contracts placed by ESO with CORNING, SCHOTT, and LZOS for the serial production of segments blanks in ULE (Ultra-Low Expansion glass), Zerodur and Astro-SitaU, respectively. 

In 8CB, continued cooling into the smectic phase reveals the appearance of a broad ultra-low-frequency feature centred at around 10 cm where no other modes are seen. This is shown in Fig. 15. This feature appears to be unique to the smectic phase and has been tentatively attributed to intermolecular dipolar coupling across smectic layers [79]. In principle this should be a generic feature of smectics but it will be necessary to explore this issue through extensive computer simulations using realistic, shape-dependent potentials for... 

Erythrocyte cholinesterase levels were monitored in two men exposed dermally to methyl parathion after entering a cotton field that had been sprayed with this pesticide (Nemec et al. 1968). The field was entered on two separate occasions twice within 2 hours after an ultra-low-volume spraying and a third time within 24 hours after spraying. Dermal methyl parathion residues 2 hours after spraying were 2-10 mg on the arms dermal residues 24 hours after spraying were 0.16-0.35 mg on the arms. The exposed individuals did not have signs of cholinergic toxicity, but erythrocyte cholinesterase levels after the third exposure were 60-65% of preexposure levels. 

Methyl parathion is marketed as a technical grade solution (80% methyl parathion) or in emulsifiable concentrate, wettable powder, ultra-low volume (ULV) liquid, dustable powder, and encapsulated suspension forms (HSDB 1999). The technical grade solution contains 80% active ingredient, 16.7%... 

Nemec SJ, Adkisson PL, Dorough HW. 1968. Methyl parathion adsorbed on the skin and blood cholinesterase levels of persons checking cotton treated with ultra-low-volume sprays. J Econ Entomol 61 1740-1742. 

The most crucial component of an AFM is the cantilever. The deflection should be sufficiently large for ultra low forces (0.1 nN). Therefore, the spring constant should be as low as possible (lower than 1 N/m). On the other hand, the resonance frequency of the cantilever must be high enough (10 to 100 kHz) to minimize the sensitivity to mechanical vibrations (e.g., vibrational noise from the building —100 Hz, frequency of the corrugation signal up to a few kHz). The... 

Flowever, in order to probe the fracture toughness of thin films or small volumes using ultra low load indentation, it is necessary to use special indenters with cracking thresholds lower than those observed with the Vickers or Berkovich indenters (for Vickers and Berkovich indenters, cracking... 

Recently, room temperature ionic liquids (RT-ILs) have attracted much attention for their excellent properties, e.g., wide temperature range of liquid phase, ultra-low vapor pressure, chemical stability, potential as green solvents, and high heat capacities [64,65]. These properties make them good candidates for the use in many fields, such as thermal storage [66], electrochemical applications, homogeneous catalysis [67], dye sensitized solar cells [68], and lubricants [69,70]. 

However, investigations up to now have mainly concentrated themselves on ambient environments even though it is known that ionic liquids have a very low vapor pressure, making them suitable for vacuum applications such as in space mechanisms, the disk drive industry, and microelec-tromechanical systems (MEMS). Due to the ultra-low vapor pressure of most ionic liquids, they have been expected to be good lubricants in vacuum. Further experimental works are required to evaluate lubrication behavior of ionic liquids under ultra-high vacuum conditions and in inert atmospheres. 

Due to lack of deterministic solutions of mixed lubrication in the literatures, it is difficult to conduct a direct result comparison in the mixed lubrication regime. Considering the fact that at the ultra-low speed mixed lubrication would transit to the boundary lubrication or lubricated contact... 

TABLE 4—Working conditions for mixed lubrication of ultra-low speed cases. ... 

For a-C H coating, the friction coefficient is strongly influenced by H content in the coating, and by relative humidity (RH). At low humidity, the friction coefficient can be achieved as low as 0.02 [25]. The friction coefficient increases to 0.1 0.15 as the RH rises to 30 % and above. An ultra-low friction coefficient of 0.001 0.005 was reported to be achieved for high hydrogen content a-C H coating in... 

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