Materials science

1 WRITTEN ESSAY Paragraph 1 The FePO4 crystal is examined at various temperatures ranging between 294K and 1073K by neutron powder diffraction. At relatively low temperatures, FePO4 adopts an α-quartz structure, which is tetrahedral. High pressures causes a phase change to a more dense octahedral structure, which is known as β-phase. The transition temperature is 980K. Cutoffs can be observed during the firstorder transition,. For α-phase, the increases in cell parameters…

The lattice symmetry of quartz α-FePO4 is trigonal. Its space group is P3121. The lattice symmetry of quartz β-FePO4 is hexagonal. It space group is P6422. According to the article, only two of the various quartz homeotypes which exhibit alpha-beta transitions have been studied in detail at high temperature. One of them is Silicon Dioxide. As such, it is possible for silicon dioxide to have the same structure when the chemistry is completely different. Since iron…

same load. As a result the graft part is wider than the vessel itself. On the other hand, silicon rubber is displaced less than the vessel and axiomatically narrower than the vessel itself. The reason and main cause of this difference between two materials is that, the stiffness of polyurethane is lower than that of the vessel and on the other side silicone rubber has a higher stiffness value. This matter can affect hemodynamic parameters as narrowing the section can increase the velocity and…

was clear from the data obtained by polarized light microscope (Figs. 4G and H) that the Haversian system is found as an individual canal system, the boundaries, which are marked by an occasional very faint line representing what has been called the cement line by Cook et al. [47]. Osteocytes, found in cavities (lacunae) within the matrix, were noticed. Dark precipitate in the form of a thick black line may indicate the presence of calcium phosphate in…

ground quartz particles. Fig. 9 described water reduction effect as adding crushed quartz filler (QF) to MgO-SiO2 binary system to maintain a fixed flow of MgO-SF-QF ternary system (Series 3, 4, 5). It is obvious that the replacement of cementitous materials by crushed quartz filler improves rheology considerably, expressed by the consistent reduction of water content while maintaining a fixed flow of…

water absorption and smooth texture of finely ground quartz particles. Fig. 9, 10 described water reduction effect of adding crushed quartz filler to maintain a fixed flow of MgO-SF-QF ternary systems (Series 3, 4, 5). The replacement of cementitous materials by crushed quartz filler improves rheology considerably, expressed by the consistent reduction of water content while maintaining a minimum flow of 120-125 mm for workability. The amount of reduced water is proportional to the increase…

Written exercise Paragraph 1 Iron phosphate, FePO4, has a very similar structure as quartz. Quartz has a trigonal lattice structure with space group P3121 (group no. 152). Similarly, at temperature below 980K, iron phosphate exists as α-FePO4, which also exhibits trigonal lattice structure with space group P3121 in which iron, phosphate and oxygen occupy Wyckoff position 3a, 3b and 6c respectively. In quartz, every silicon atom is connected to four oxygen atoms to form a network of…

Figure 7. TA flux across membranes prepared with different proportions of AC:Pectin (CP2 and CP3) and DBS concentrations. Mechanical properties are very important parameters in membranes and coatings. These properties determine the homogeneity, resistance and film forming capacity of the coating. In figure 8 we represent some of the more important mechanical parameters obtained by mean tensile test. Figure 8. Mechanical parameters of the EC:Pectin membranes obtained with CP2 and CP3. In the…

structures that in turn lead to distinctive flat surfaces, or faces. The faces intersect at angles that are characteristic of the substance. When exposed to x-rays, each structure also produces a distinctive pattern that can be used to identify the material. The characteristic angles do not depend on the size of the crystal; they reflect the regular…

As one of the two-dimensional (2D) materials, m-MoS2 exhibits promising electronic properties such as high carrier mobilities (200 cm2V-1s-1) at room temperature, high current on/off ratio (1×108) and ultralow standby power dissipation [7,8]. Based on atomic layer MoS2, thin film transistors…