Broad-range

When a mixture contains components with a broad range of volatilities, either a partial condensation from the vapor phase or a partial vaporization from the liquid phase followed by a simple phase split often can produce an effective separation. This is in essence a single-stage distillation process. However, by its very nature, a single-stage separation does not produce pure products hence further separation of both liquid and vapor streams is often required. 

There has been built a broad range of varieties of the basic tube design already ... 

The model of non-mteracting hannonic oscillators has a broad range of applicability. Besides vibrational motion of molecules, it is appropriate for phonons in hannonic crystals and photons in a cavity (black-body radiation). 

In this situation, particularly when a broad range of organic reactions has to be predicted, the simulation of reactions based on knowledge gained from experience is the method of choice. This will be the theme of this chapter. 

Nowadays a broad range of methods is available in the field of chemoinfor-matics. These methods will have a growing impact on drug design. In particular, the discovery of new lead structures and their optimization will profit by virtual saeening [17, 66, 100-103]. The huge amounts of data produced by HTS and combinatorial chemistry enforce the use of database and data mining techniques. 

The solvents listed in Table 2.1 were chosen to cover a broad range in solvent properties. In fact hexane was initially also among them, but unfortunately the rate of the reaction in this solvent is extremely low. It turned out that in this solvent spontaneous decomposition of 2.4a competes with the Diels-Alder reaction. 

Antistatic agents require ambient moisture to function. Consequently their effectiveness is dependent on the relative humidity. They provide a broad range of protection at 50% relative humidity. Much below 20% relative humidity, only materials which provide a conductive path through the bulk of the plastic to ground (such as carbon black) will reduce electrostatic charging. 

Isotherms for H2O and / -hexane adsorption at room temperature and for O2 adsorption at Hquid oxygen temperature on 13X (NaX) zeoHte and on the crystalline Si02 molecular sieve siHcaHte are are shown in Figure 8 (43). SiHcaHte adsorbs water very weaMy. Further modification of siHcaHte by fluoride incorporation provides an extremely hydrophobic adsorbent, shown in Figure 9 (44). These examples illustrate the broad range of properties of crystalline molecular sieves. 

In contrast to trace impurity removal, the use of adsorption for bulk separation in the liquid phase on a commercial scale is a relatively recent development. The first commercial operation occurred in 1964 with the advent of the UOP Molex process for recovery of high purity / -paraffins (6—8). Since that time, bulk adsorptive separation of liquids has been used to solve a broad range of problems, including individual isomer separations and class separations. The commercial availability of synthetic molecular sieves and ion-exchange resins and the development of novel process concepts have been the two significant factors in the success of these processes. This article is devoted mainly to the theory and operation of these Hquid-phase bulk adsorptive separation processes. 

This brief overview of the types of fibrous materials is intended to indicate the broad range of materials that can be produced from fibers. Since the properties of fibrous materials depend both on the properties of the fibers themselves and on the spatial arrangement of the fibers in the assembly, a given type of fiber may be used in many different end products, and similarly a given end product can be produced from different fiber types. 

The properties of commercial rigid foamed plastics are presented in Table 2. The properties of commercial flexible foamed plastics are presented in Table 4. The definition of a flexible foamed plastic is that recommended by the ASTM Committee D 11. The data shown demonstrate the broad ranges of properties of commercial products rather than an accurate set of properties on a specific few materials. Specific producers of foamed plastics should be consulted for properties on a particular product (137,138,142). 

CellgeometTy is governed predominantly by the final foam density and the external forces exerted on the cellular stmcture prior to its stabilization in the expanded state. In a foam prepared without such external forces, the cells tend to be spherical or ellipsoidal at gas volumes less than 70—80% of the total volume, and they tend toward the shape of packed regular dodecahedra at greater gas volumes. These shapes have been shown to be consistent with surface chemistry arguments (144,146,147). Photographs of actual foam cells (Fig. 2) show a broad range of variations in shape. 

Ethylene vinyl acetate copolymer (EVA) forms a soft, tacky film with good water-vapor barrier but very poor gas-barrier properties. It is widely used as a low temperature initiation and broad-range, heat-sealing medium. The film also serves for lamination to other substrates for heat-sealing purposes. 

The chemical characteristics of biomass vary over a broad range because of the many different types of species. Table 8 compares the typical analyses and energy contents of land- and water-based biomass, ie, wood, grass, kelp, and water hyacinth, and waste biomass, ie, manure, urban refuse, and primary sewage sludge, with those of cellulose, peat, and bituminous coal. Pure cellulose, a representative primary photosynthetic product, has a carbon content of... 

Overall research on the development of herbaceous energy crops shows that a broad range of plant species may ultimately be prime energy crops. 

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