Engineering and Technology Journal

This study aims to find the effect of hydroxide mixture as a quenching medium in martempering heat treatment on microstructure and mechanical properties of high chromium white cast iron. This mixture is cheaper and more available than the ordinary nitrate mixture in Iraqi markets. High chromium white cast iron is used in mining, crushing and cement plants as mill liners and it is subjected to extreme conditions of wear and impact that cause failure, reduction in life and raise the cost of repairing. Hence it is important to improve its mechanical properties. In this study, two types of quenching mediums were used:(50% NaOH: 50% KOH ) mixture and (50% NaNO3 + 50 % KNO3) mixture. The specimens were austenitized at 950°C for 1 hr then the first group was quenched in nitrate mixture, and the other was quenched in hydroxide mixture both at about 350°C for (1/2, 2,4,6,8) hr. The results showed an increase in hardness and decrease in toughness for both mixtures, and the higher hardness value was found for both of the mixtures at martempering temperature 350°C for 4hr quenching time.

As maxillofacial defects increased due to cancer; it became necessary to select high-quality prosthetic materials in this field. Silicone rubber is widely used in damaged maxillofacial affected areas replacement surgery as bio material. The aim of this research, prepared a nano composites materials, from polymer blend (silicone rubber: 5% PMMA) reinforced by different types of nano-powders; pomegranate Peels Powder (PPP), Seeds powder of dates Ajwa (SPDA) and TiO2 nano-powders with loading level (0.0, 0.1, 0.2, 0.3 and 0.4%). Some physical properties such as density, water absorption, and Thermo-Physical test, FTIR analysis, as well as, FTIR, antibacterial tests were done on prepared samples. The results showed that the composites material based of polymer blend with optimum percent are of 0.2% of pomegranate Peels Powder (PPP), 0.3% of Seeds powder of dates Ajwa (SPDA) and 0.1% of TiO2 nano-powders that have ideal characteristic. Also for antibacterial tests, polymeric blend composites with optimum percent of this nano-powders show that more antibacterial efficiency against S.aureus bacteria than E.coli bacteria.

Two 3D printed materials (Polylactic Acid and Carbon fiber) with variable printing density have been investigated due to their practical uses in engineering utilization. The effect of printing density composites was studied by the tensile test. The used materials stress-strain curves were analyzed to find modulus of elasticity and the ultimate tensile strength of the mentioned materials. The results manifested that carbon fiber has the highest strength-weight ratio. On the other hand, the carbon fiber showed more ductility than the Polylactic Acid. The results of this work will be aiding the researchers or engineering students to decide which material is suitable for 3D printing applications.

Alumina has wide industrial and technological applications that can be extracted from different locations, different methods and materials. Kaolin from Iraq Alduikhla astrologer has used as a raw material source for alumina production. The alumina concentration in the Iraqi kaolin is more than 34% which considered as a good replacement for bauxite rack. Crushing andground is the first process to reduce the kaolin particle size to the micron level which increases the surface area of kaolin.
The kaolin is heat treated at different temp for 2 hours to remove some of ithe mpurity like organic materials and crystal water before acid treatment. A different concentration of hydrochloric acid (pH) (0.45, 0.5, 0.55, 0.6 and 0.65) has used for extraction of al has decreased with increase t inhe reaction temperature. Finally t,,he alumina extraction by this method has characterized using XRD and XRF to investigation the crystal structure and the amount of impurities presented there. The final extracted alumina h is v g γ alumina) with purity above 95%.

Land cover land use changes constantly with the time at local, regional, and global scales, therefore, remote sensing provides wide, and broad information for quantifying the location, extent, and variability of change; the reason and processes of change; and the responses to and consequences of change. And considering to the importance of mapping of (LCLU). For that reason this study will focus on the problems arising from the traditional classification (LCLU) that based on spatial resolution only which leads to prediction a thematic map with noisy classes, and using a new method that depend on spectral and spatial resolution to produce an acceptable classification and producing a thematic map with an acceptable database by using artificial neural network (ANN) and python in additional to other program. In this study the methods of classification were studied through using two images for the same study area , rapid eye image which has three spectral bands with high spatial resolution(5m) and Landsat 8 image (high spectral resolution with eight bands), also several programs like ENVI version 5.1, Arc GIS version 10.3, Python 3, and GPS. The result for this research was sensuousness as geometrics accuracy accepted in map production.