Scatterers, ideal

Figure B2.3.1. Schematic diagram of an idealized molecular beam scattering experiment.

Optical Applications. Vitreous siUca is ideal for many optical appHcations because of its excellent ultraviolet transmission, resistance to radiation darkening, optical polishing properties, and physical and chemical stabiUty. It is used for prisms, lenses, cells, wiadows, and other optical components where ultraviolet transmission is critical. Cuvettes used ia scatter and spectrophotometer cells are manufactured from fused siUca and fused quart2 because of the transmissive properties and high purity (222). 

Any perturbation from ideal space-group symmetry in a crystal will give rise to diffuse scattering. The X-ray diffuse scattering intensity at some point (hkl) in reciprocal space can be written as... 

The dependence on target mass makes ion scattering techniques ideal for the study of multielement systems. By increasing the incident ion mass, the energy separation between different elements becomes larger. On the other hand, radiation-induced damage becomes a more important consideration. 

The solid-liquid transition temperatures of ionic liquids can (ideally) be below ambient and as low as -100 °C. The most efficient method for measuring the transition temperatures is differential scanning calorimetry (DSC). Other methods that have been used include cold-stage polarizing microscopy, NMR, and X-ray scattering. 

Let us give a brief summary of the LSGF method. We will consider a system of N atoms somehow distributed on the underlying primitive lattice. We start with the notion that if we choose an unperturbed reference system which has an ideal periodicity by placing eciuivalent effective scatterers on the same underlying lattice, its Hamiltonian may be calculated in the reciprocal space. Corresponding unperturbed Green s... 

It is simplest to consider these factors as they are reflected in the entropy of the solution, because it is easy to subtract from the measured entropy of solution the configurational contribution. For the latter, one may use the ideal entropy of mixing, — In, since the correction arising from usual deviation of a solution (not a superlattice) from randomness is usually less than — 0.1 cal/deg-g atom. (In special cases, where the degree of short-range order is known from x-ray diffuse scattering, one may adequately calculate this correction from quasi-chemical theory.) Consequently, the excess entropy of solution, AS6, is a convenient measure of the sum of the nonconfigurational factors in the solution. 

Further improvements on the previously discussed models were proposed in the latest model for y - and e - Mn02 by Chabre and Pannetier [12, 43, 44], Starting from De Wolff s model they developed a structural description of manganese dioxides that accounts for the scattering function of all y - and e - Mn02 materials and provides a method of characterizing them quantitatively in terms of structural defects. All y — and e - Mn02 samples can be described on the basis of an ideal ramsdellite lattice affected by two kinds of defects ... 

Kaye and Chou39 also studied the effect of base stacking on the conformation of PA using osmometry, intrinsic viscosity, and light-scattering. The ideal behavior (under the 0 conditions) of PA existed at neutral pH (= 7.4) and at 26 and 40 °C from the osmotic measurements. 

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