Artificial surfaces

A grass-like artificial surface was installed for the first time in 1964, at Moses Brown School (Providence, Rhode Island) (1). In 1966, artificial turf was installed in the Houston Astrodome in Texas. These surfaces consisted of green pigmented, nylon-6,6 pile ribbon, with a cross-section resembling that of natural grass. Since that period, other fabrics of various pile ribbon and constmctions have continued to become available commercially for indoor and outdoor facihties. 

These grass-like and resident instadations require substantial amounts of synthetic materials. A typical sports field covered with artificial turf requires approximately 15,000 kg of fabric, 15,000—30,000 kg of shock-absorbing underpad, and 5,000—10,000 kg of adhesive and seaming materials. The artificial surface for a 0.40-km miming track may require 50,000—70,000 kg of materials. Paint striping and marking of turf, tracks, and courts cad for additional materials. 

Light-Duty Recreational Surfaces. Artificial surfaces intended for incidental recreational use, eg, swimming pool decks, patios, and landscaping, are designed primarily to provide a practical, durable, and attractive surface. Minimum cost is a prime consideration and has driven the quaUty of some such products to a low level. Most surfaces in this category utilize polypropylene ribbon and a tufted fabric constmction (see Olefin polymers, polypropylene). ... 

Game-Related Properties. Eot some activities, such as miming and wrestdng, the only consideration is the direct impact by the player. Eot others, eg, tennis, baseball, or soccer, the system must also provide acceptable bad-to-surface contact properties. Important bad-response properties on the artificial surface ate coefficients of restitution and friction, because these direedy determine the angle, speed, and spin of the bad. 

Artificial surfaces must be resistant to cigarette bums, vandaUsm, and other harm. Fire resistance is most critically evaluated by the NBS flooring radiant panel test (10). In this test, a gas-fired panel maintains a heat flux, impinging on the sample to be tested, between 1.1 W/cm at one end and 0.1 W/cm at the other. The result of the bum is reported as the flux needed to sustain flame propagation in the sample. Higher values denote greater resistance to burning results depend on material and surface constmction. Polypropylene turf materials are characterized by critical radiant flux indexes which are considerably lower than those for nylon and acryflc polymers (qv) (11). 

Table 6. Typical Properties of Yams Suitable for Pile Components of Artificial Surfaces...

Fig. 3. Constmction of (a) pile fiber held in place by latex (tufted) and (b) pile fiber tied into backing (knitted) grass-like artificial surfaces.

In terms of surface area covered, artificial turf is the dominant commercial product in the category of artificial surfaces described in this article. Light-duty surfaces are the largest representative, followed by tennis court and multipurpose recreational surfaces. 

Computer simulations of bulk liquids are usually performed by employing periodic boundary conditions in all three directions of space, in order to eliminate artificial surface effects due to the small number of molecules. Most simulations of interfaces employ parallel planar interfaces. In such simulations, periodic boundary conditions in three dimensions can still be used. The two phases of interest occupy different parts of the simulation cell and two equivalent interfaces are formed. The simulation cell consists of an infinite stack of alternating phases. Care needs to be taken that the two phases are thick enough to allow the neglect of interaction between an interface and its images. An alternative is to use periodic boundary conditions in two dimensions only. The first approach allows the use of readily available programs for three-dimensional lattice sums if, for typical systems, the distance between equivalent interfaces is at least equal to three to five times the width of the cell parallel to the interfaces. The second approach prevents possible interactions between interfaces and their periodic images. 

Bhushan B, Jung YC (2011) Natural and biomimetic artificial surfaces for superhydro-phobicity, self-cleaning, low adhesion, and drag reduction. Prog Mater Sci 56 1-108... 

The drawback of these techniques is the requirement of artificial surfaces for the stabilization of the films created. 

TIRF has been used to study equilibrium adsorption of proteins to artificial surfaces both to learn about the surface properties of various biomaterials that have medical applications and also to test the TIRF technique itself. 

For TIR/FRAP to be useful for chemical kinetics studies on intact biological membranes as opposed to reconstituted or artificial surfaces, two problems must be confronted (1) how to position the membrane in a TIR... 

Other cultivation strategies which were followed were the enrichment of picoplankton bacteria under a wide range of nutrient and incubation conditions [33], and isolation of biofilm bacteria that had grown in situ on artificial surfaces. 

Salt caverns are developed by solution mining, a process (leaching) in which water is injected to dissolve the salt. Approximately 7 to 10 units of fresh water are required to leach 1 unit of cavern volume. Figure 10-190 illustrates the leaching process for two caverns. Modern salt dome caverns are shaped as relatively tall, slender cylinders. The leaching process produces nearly saturated brine from the cavern. Brine may be disposed into nearby disposal wells or offshore disposal fields, or it may be supplied to nearby plants as a feedstock for manufacturing of caustic (NaOH) and chlorine (CI2). The final portion of the produced brine is retained and stored in artificial surface ponds or tanks to be used to displace the stored liquid from the cavern. 

The photod)mamic approach has been applied for the cleaning and disinfection of artificial surfaces, especially for the destruction and inactivation of biofilms. In the majority of cases, it was proposed for the cleaning of surfaces in hospitals (Decraene et al., 2008a,b) and the disinfection of medical devices such as implants (Sharma et ah, 2008). Only a few papers on the application of PDT targeted to the needs of the food industry have been published. 

Shoe traction -on artificial surfaces (RECREATIONAL SURFACES] (Vol 20)... 

Platford, R.F. (1982) Pesticide partitioning in artificial surface films. J. Great Lakes Res. 8, 307-309. 

Fig. 13. a Schematic description of the molecules involved in the processes of cell adhesion and migration. Inside the leading edge of the cell, actin filaments (1) are connected via vinculin (2) and talin (4) to integrins, a family of proteins (5) which span the membrane (6). Outside, the integrins have epitopes which normally bind to fibronectin (3) but they can also adhere to artificial surfaces. At the other end of the cell the molecular contacts are broken and the material is recycled, b On artificial surfaces recycling is hindered and cell trails can be observed, c and d Under higher resolution cell trails are seen to be filament like structures or patches... 

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