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.

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.

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.

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.

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.

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.

The molybdenum dicilicide is an intermetallic compound with two allotropies tetragonal MoSi2 and hexagonal MoSi2. The MoSi2 PHASE is established to 1900oC and MoSi2 PHASE from 1900 to 2050oC. This material has considerable properties that provide different applications in different industries such as air-space industry and gas turbines. The molybdenum synthesis can be down in various ways such as melting and casting, SHS (Self propagating High temperature Synthesis). Recently, the mechanical alloying method because of its considerable advantages such as powder particle compound homogenizing, fragmentation and contact area increasing and also crystal defect increasing that affects ductility increasing of brittle compound such as intermetallic compounds, is used for progressive materials synthesizing. In this research, the synthesis and formation of molybdenum diciliside was investigated by mechanical alloying method from stoichiometric mixing molybdenum and silicon (Mo/2Si) and also its PHASE TRANSFORMATIONs. A mixture of elemental molybdenum and silicon powders at the stoichiometric composition of MoSi2 were ball milled to 100 hours using a planetary ball mill. The milling was performed at rotational speeds (vial speeds) of 300 and 400 rpm and stainless steel balls (5 and 10 mm in diameter). Other synthesis conditions such as ball to powder weight ratio and mass of the charged powder were chosen similarly. The results demonstrate that mechanical milling affects the formation of nanocrystalline MoSi2 from elemental powders through solid state reaction. In other words, formation of molybdenum disilicide from its primary elements during mechanical alloying depends on effective parameters in mechanical alloying (collision frequency of ball to powder particles, contact area creation and heat transferred to powder particles view point) according to XRD results. The results indicate that increasing in milling intensity and decreasing in ball diameter cause to fast formation of MoSi2, which is derived of increasing in milling energy. The thermal analysis investigation confirmed affection of mechanical activation on the acceleration of MoSi2 synthesis with reduction of formation temperature of molybdenum disilicide during mechanical alloying and electron microscopic investigation showed that MoSi2 forms on the surface of molybdenum grains during mechanical alloying. It was also demonstrated that formation of MoSi2 (a and/or b) depends on mechanical activation conditions and selection of parameters during mechanical alloying. So that if intensity of mechanical activation be chosen high and/or selection of parameters contribute with high heat production in milling vials, MoSi2 PHASE alone or with MoSi2 PHASE (that has low activation energy with respect to MoSi2) will be produced. In lower milling intensity, usually at first MoSi2 is produced. PHASE TRANSFORMATION of occurs during mechanical alloying when the crystallite size decreases to approximately 12 nm. The final product of mechanical alloying is MoSi2.