In this experimental work the pressure induced phase transformation of silicon and Germanium has been studied. It was shown that at a particular value of applied pressure, (Pt), depending on the sample temperature, the electrical resistance of the specimen falls off to a metallic state. The main goal of this study was to find out how the phase transformation pressure, Pt, for a p-type silicon varies with the sample temperature. The results show that, the value of Pt  decreases linearly as the temperature of the sample increases. Meanwhile, other related results including the rate of resistance change in accordance with applied pressure on the sample at different temperatures (~270-350K), both for the semiconductor and the metallic state of the specimen were determined. In another effort, the amount of Pt for an n-type germanium, but only at room temperature, was also determined.

Austenitic stainless steels exhibit a low hardness and weak tribological properties. The wear behaviour of austenitic stainless steel AISI 316 was evaluated through the pin on disc tribological method. For investigating the effect of wear on the changes in microstructure and resistance to wear, optical microscopy and scanning electron microscope were used. The hardness of the worn surfaces was measured with a micro-hardness tester. Worn surfaces were analyzed through X-ray diffraction. Results showed that with increasing the sliding distance and applied load, the austenite phase partially transformed to a martensite, and there was no trace of e phase detected. Due to the formation of probably hard and strong martensite phase, as the sliding distance and applied load increased, the hardness and the wear resistance of the material was increased. Wear mechanism was on the base of delamination and abrasion.

In this research, the effect of mechanical activation on phase transformation of monoclinic zirconia was investigated. It was revealed that the transformation of monoclinic to tetragonal at a temperature as high as 1250° C is very slow. Milling of pure zirconia with monoclinic structure facilitates this phase transformation. The XRD patterns of the milled samples show that after 4 hrs tetragonal peaks are appeared and after 48 hrs phase transformation is completed. The kinetics of this transformation was also studied and the corresponding correlation was proposed. Cubic structure could also been obtained after 150 hrs milling. The sharp increase of the pressure and temperature at the collision points of the balls are the main reasons for this phase transformation at the ambient overall temperature.

A series of Cu1-x Zn x Fe2O4 ferrite (with x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) compositions were synthesized using the standard solid-state reaction technique. X-ray diffraction was used to study the structure of the above investigated samples. The theoretical and experimental lattice parameters (ath and aexp) were calculated for each composition. A significant decrease in density and subsequent increase in porosity were observed with increasing Zn content. Curie temperature, T C, has been determined from the temperature dependence of permeability and found to decrease with increasing Zn content. The anomaly observed in the temperature dependence of permeability was attributed to the existence of two structural phases: cubic phase and tetragonal phase. Low-field hysteresis measurements have been performed using a B- H loop trace from which hysteresis parameters have been determined. Coercivity and hysteresis loss were estimated with different Zn contents.

In this paper, solid phase transformation of titanium oxide nanoparticles at different heat treatment conditions were investigated using different developed kinetic models. The agreement of the developed models which are a combination of nucleation and growth, with experimental data for solid phase transformation of titania with nanoparticle size at dry heat treatment and hydrothermal conditions were checked and the results show that the developed models are able to predict kinetic transformation of titanium oxide polymorph. Result also shows that nucleation mechanism of Anatase formation from amorphous solid phase in a solution is a surface nucleation and at dry heat treatments at temperatures of 300-400oC is of combined interface and surface nucleation. Researchers have stated that in solid transformation of Anatase nanocrystals to Rutile at temperature below 600oC, transformation occurs by interface nucleation mechanism. The results of this work show that due to particle growth at dry heat treatment condition at long period of time, surface nucleation can also play an important role. The advantage of the models developed in this work over other models is that, these models can predict the solid phase transformation of TiO2 nanoparticles without the need for data on titanium oxide nanoparticle size.

Urban centres in the world are undergoing facets of changes. these changes are evident in developing countries and more divergent because urban transformation in developing countries is often accompanied challenges which include traffic congestion, overcrowding, pollution and continuous land use succession. This phenomenon remains peculiar to the central area of Minna, Nigeria. Since the year 2008, central Minna has undergone approaches aimed at addressing overcrowding, street trading, indiscriminate waste disposal and traffic congestion. Data employed in this study includes high resolution image of the the Minna central area and socioeconomic characteristics of Minna obtained through the use of questionnaires using purposive sampling techniques. The data were corroborated with Geo-spatial analysis. The study reveals that between 2008 to 2016 there was a significant change in urban transformations in Minna central area as 75% of the residential area were converted to commercial uses, although the Minna central market was also relocated to a new site in order to address the issues, little was however achieved as this only relocated the problems to another part of the town. This study recommends that urban management and monitoring (development control) of Minna city centre and similar cities should imbibe the current SDGs approach that emphasizes participation and inclusive planning approach to urban development.

Anatase-to-rutile phase transformation was studied in milled and unmilled samples. Ball milling was carried out in two types of ball mills, planetary and tumbler, with a ball-to-powder ratio of 40:1 over 2-48 hours. First, the unmilled samples were heated in the furnace at various temperatures for different periods of time. The results revealed that the anatase-to-rutile transformation completed at 980 oC after 48 hours. The rate of transformation in milled samples was greatly higher than that of unmilled ones. Activation energy in unmilled samples was about 440 kj/mol. The rate of transformation in the planetary ball mill was higher than that in tumbler mill. In the former, transformation almost finished after 16 hours of milling while in the lattar, it did not finish even after 48 hours. XRD results revealed that the transformation proceeds through an intermediate srilankite phase in all milled samples. However, srilankite was not observed in the unmilled samples.

In this research the behavior of the steel AISI 422 has been investigated during the various continuous cycle of cooling in dilatometer and CCT diagram has been obtained. The standard test samples were prepared in accordance with the requirements of the standard Dilatometers SEP 1681 in cylinders with a diameter of 4 mm and length of 10 mm. In the dilatometer test, heating the samples were conducted in controlled vacuum atmosphere. The results showed that after reaching the austenitizing temperature of 1040oC, holding time of 15 minutes , cooling time of 5, 15, 30 minutes, 1, 3, 6, 12 and 18 hours, martensite was formed in range of 238-300oC. Colling In 24, 36 and 48 hours, pearlite phase was formed. The start temperature range of this transformation was 472-621oC and the final temperature rang of perlite transformation was 367-504oC. The martensite transformation for this cooling times was 300-310oC. In the cooling time of 36 hours, the bainite phase was formed in the temperature rang of 402-451oC. The results of this steel's hardenability test showed high hardenability and the jominy curve showed constant line.