Surface trends

Lee, J., Ishihara, A., Jacobson. K. (1993). How do cells move along surfaces Trends Cell Biol. 3, 366-370. 

Ishihara K (1997) Novel polymeric materials for obtaining blood compatible surfaces. Trends in Polym Sci 5 401 -07... 

Palmer, R.E. and C. Leung (2007) Immobilisation of proteins by atomic clusters on surfaces. Trends Biotechnol. 25, 48-55. 

Georgiou G, Poetschke H L, Stathopoulos C, et al. (1993). Practical applications of engineering gram-negative bacterial cell surfaces. Trends Biotechnol. 11 6-10. 

Wachutka G, Fleszar A, Maca F and Scheffler M 1992 Self-consistent Green-function method for the calculation of electronic properties of localized defects at surfaces and in the bulk J. Phys. Condens Matter A 2831 Bormet J, Neugebauer J and Scheffler M 1994 Chemical trends and bonding mechanisms for isolated adsorbates on Al(111) Phys. Rev. B 49 17 242... 

Detergents may be produced by the chemical reaction of fats and fatty acids with polar materials such as sulfuric or phosphoric acid or ethylene oxide. Detergents emulsify oil and grease because of their abiUty to reduce the surface tension and contact angle of water as well as the interfacial tension between water and oil. Recent trends in detergents have been to lower phosphate content to prevent eutrification of lakes when detergents are disposed of in municipal waste. 

Sheet can be produced by melt extmsion, but in this case a three-roll stack of quenching roUs is generally used (Fig. 2). More than three roUs may be used where necessary. The roUs may be mounted vertically or horizontally. The web is extmded through a slot die in a thickness close to the desired final thickness. The die is in very close proximity to the first chill roU or chill-roll nip. The web may be cast horizontally directly onto the upper chill roU of the stack as shown (Fig. 2), or it may be extmded into the first nip directly. The roUs quench the sheet and provide the surface polish desired. In some applications, matte or embossed roUs maybe used to impart special surface characteristics for certain functions. Where the utmost in optical (glazing) quality is desired the trend has been to mount the roU stack horizontally. The hot melt is then extmded vertically down into the first nip. This avoids problems associated with sag of a horizontal hot melt no matter how short the distance between die and quench. 

The physical characteristics of /i /f-amyl alcohol diverge from the standard trends for the other alcohols it has a lower boiling point, higher melting point, higher vapor pressure, and low surface tension. Most notably, organic molecules are highly soluble in /i /f-amyl alcohol. 

Requirements for tire cord material will to some extent be driven by new vehicle trends. Eor example, the clean air emphasis in North America places lightweight vehicles and materials at a premium. Eor tire cord the fuel economy or rolling resistance provided by the cord—mbber composite may shift the pattern of usage. A common requirement for all types of tire cord surfaces is a high strength-to-weight ratio. 

Even rain is not pure water. Reports from the U.S. Geological Survey show that it contains 2.3—4.6 ppm of soflds, or a yearly precipitation of 2.5—5 t/km. Recently (ca 1997), work conducted ia the United States and Europe has underscored the rather dangerous results of iacreased use of fossil fuels, where the SO and NO emissions that end up ia the rain lower its pH from 5.6 (slightly acidic) for uncontaminated rain, to acid rains. Such acid rain has serious effects on surface waters (1). About 40 x 10 t of SO and 25 x 10 t of NO were emitted ia the United States ia 1980. There are, however, encouragiag trends the 1970 Clean Air Act has led to a gradual reduction ia these emissions, bringing the SO emissions down from the previous levels cited by 10% by 1990, and the NO emissions down by 6%, with a consequent slight decrease ia rain acidity. A part of the Clean Air Act is also iatended to cap SO emissions from major poiat sources at 13.5 x 10 t (2). Between 1994 and 1995, total SO emissions ia the U.S. decreased remarkably by 13% and total NO emissions by 8%. 

Fig. 1. Trends of estimated ground and surface freshwater use in the United States, 1950—1990 (10).

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