This review presents the composition, structure, mechanical characteristics, and applications of alumina (aluminum oxide) in biomedical. Alumina used for implant manufacturing is either single-crystal sapphires or high density and quality polycrystalline. The major sources of highly-purity alumina are organic corundum and bauxite. Like any other brittle component, polycrystalline alumina's mechanical characteristics are largely dependent on grain size and porosity distribution. It was shown that, due to slowed subcritical crack production, the fatigue intensity of alumina could be increased above the crucial pressure due to the presence of liquid. Due to its high inertness, that results in outstanding biocompatibility and tissue nonsensitization, alumina has significant benefits over other products in biomedical uses. Just like in artificially joints and teeth, the higher compressive strength than tensile strength allows it more efficient for compressive loadings. There were some attempts for coating alumina on steel substrates in order to benefit of its outstanding biocompatibility and to resist metal oxidation.

Water is the most important natural resources in countries with desert and semi-desert climates like Iraq because it controls the distribution of population and economic activities, especially agriculture. Water pollution is one of the major global problems of the scientific and political community. It threatens health, threatens life, impairs industrial activity and develops civilization. So this work aims to determine the qualitative changes in Tigris River water in Baghdad city through the evaluation of the river water quality in the seasons of the year using the water treatment project (W.T. Projects) operating in Baghdad city as a source of raw water. Samples of water were taken from the same point for four months (January, February, March and April). Seven water stations W.T. Projects were investigated as a fixed site area Al-Wahda, Al-rashed, Al-Karama, Al-Wthba, Al-doura, Al-Qadisiya, Um al-Khanazeer, Shark Dijla and Al-Khademya. The concentrations of nitrate, and nitrite in the water of Tigris River in Baghdad and their suitability to the conditions permitted internationally was tested. The samples of water of Tigris River have been conducted in winter and spring for the year of the study. The results of this work were examined and analyzed and the samples of the water taken and the rivers fed to it and the result of the year 2018 were compared to the data provided by the W.T. Projects for years 2015, 2016 and 2017. Then, the Nitrate and Nitrite were compared with the ratios measured in the past years after taking readings from the concerned departments and ministries for the W.T. projects (Ministry of Environment, Water Resources, and Baghdad Municipality). To do so, an extensive determination of the efficiency of the river’s water and the areas of pollution and identifying ways to reduce the degree of pollution. These tests carried to identify the main environmental problems affecting the quality of Tigris water and finding areas of pollution and thus identify ways to reduce the degree of pollution to reach the best ways to protect the aquatic environment. This work identifies the areas of pollution in water of the river, which will serve as a guide for all workers in this field.

An artificial pacemaker is a medical device that can generate electrical impulses which are delivered by electrodes to maintain the controlled rhythm of the heartbeats. Such a medical device can assist for extensive period of time and thereby regulates the pumping capacity of the heart. Usually, the need for a permanent pacemaker implantation arises from the occurrence of cardiac diseases such as failure of impulse formation (sick sinus syndrome) and/or conduction (A-V block). Functionally, a pacemaker comprises of at least three parts: an electrical pulse generator, a power source (battery) and an electrode (lead) system. This paper aims to provide a design of the trainer board of a typical pacemaker, which generates a QRS pulse and displays it on an oscilloscope which will help understand the basic components of the device for educational purposes. To do so, an extensive literature review was undertaken to comprehend the theory behind the design of a pacemaker. Further, the paper describes the practical methodology adopted in the design of the pacemaker and the achieved results of this study while making suggestions for future work.