CrystalUne structure

Based on the Wagner method [16], the required character of conductivity can be achieved by the introduction of admixture into the basis oxide, which has a common anion with the basis oxide, and the cation has less valence. Type and quantity of the defects are stipulated by the admixture and its concentration. As a rule, the majority of well-known solid electrolytes with pure oxygen-ionic conductivity have a fluorite CaFj crystalUne structure [17]. 

Polymer crystaUization is an industrially and scientifically important phenomenon that has defied detailed molecular description. The chemical structure of the polymeric chain, combined with morphological features acquired during processing governs the properties of semicrystaUine polymers. Investigations of the details of hquid-solid transformation have closely paralleled the development of polymer science and interest in understanding the details of crystalUne structure had arisen from the well known fact that the crystallinity controls the properties of the material. Polymer crystaUization is believed to... 

Figure 8.5 Schematic view of the crystalUne structure of KHCO3 at 14 K. Reproduced with permission from F. Fillaux, A. Cousson and D. Keen, Phys. Rev B 67, 054301. Copyright (2003). American Physical Society.

A few words have already been said about the crystalUne structure of cellulose (see Figure 6.1). The monocUnic unit cell structure illustrated for cellulose I was postulated many years ago by Meyer et al. (3-6) and has been confirmed many times. The b axis is the fiber direction, and the cell belongs to the space group P2, containing four glucose residues. 

Triple-base propellants are made by the addition of crystalUne nitroguanidine (NQ) to double-base propellants, similar to the way in which nitramine is added to CMDB propellants as described in the preceding section. Since NQ has a relatively high mole fraction of hydrogen within its molecular structure, the molecular mass of the combustion products becomes low even though the flame temperature is reduced. Table 4.13 shows the chemical composition, adiabatic flame temperature, and thermodynamic energy,/ as defined in Eq. (1.84), of a triple-base propellant at 10 MPa (NC 12.6% N). 

The isomerization from 10 to 11 in the crystalUne state requires not only the movements of atoms but also a change in the crystal symmetry and the reconstruction of the hydrogen bond network pattern. In the crystals of these primary ammonium carboxylates, ID ladder-type hydrogen bonds are observed. The isomerization from the ZZ to EE form is associated with the rotation of carbonyl groups and the change in the hydrogen bond structure in this case. The quantitative transformation of 10 to 11 in the crystalUne state suggests that the molecular motion in the crystals occurred cooperatively with the minimum movement of atoms in the crystals via a phase transition from the crystal of 10... 

Hydrocarbon polymers (HCP) are used not only as fuel components but also as binders of crystalUne oxidizers and metal powders in the formulation of pyrolants, similar to composite propellants and plastic-bonded explosives. There are many types of HGP, the physicochemical properties of which are dependent on their molecular structures. The viscosity, molecular mass, and functionality of the poly-... 

Structural Parameters of CrystalUne Antiparallel-Chain Pleated Sheet PolylL-alaninef... 

Zeolites are crystalUne alumino silicates with a highly ordered crystalline structure. Cavities of a definitive size are formed in three-dimensional network composed of Si04 and AIO4 tetrahedra. The lattice contains cavities of varying diameters, depending on the type of zeohtes. A distinction is made between large-, medium- and small-pore zeolites. 

The presence of covalently attached glucose residues generally causes a protein to malfunction. This has serious effects on the eye and the kidney. In the eye some of the proteins have slow turnover, such as crystalUns in the lens and structural proteins in the retina. In the kidney, structural proteins in cells and in the extracellular matrix are exposed to high concentrations of glucose from the blood and the urinary filtrate. Damage to these tissues leads to blindness, vascular disease with high blood pressure, and nephropathy, respectively. 

Deviations of this type may clearly be brought about by deviations of the structure of the zeolites imder study from the ideal structure as implied for the deviation of Eq. 17. It would be most remarkable, however, if for two completely different chabazite species, viz. the big single crystals and poly-crystalUne samples, identical deviations from the ideal structure would occur, as suggested by the experimental data. 

---