Functionally graded materials (FGMs), with ceramic –ceramic constituents are fabricated using powder technology techniques. In this work three different sets of FGMs samples were designed in to 3 layers, 5 layers and 7 layers. The ceramic constituents were represented by hard ferrite (Barium ferrite) and soft ferrite (lithium ferrite). All samples sintered at constant temperature at 1100oC for 2 hrs. and characterized by FESEM. Some physical properties were measured for fabricated FGMs include apparent density, bulk density, porosity, shrinkage and hardness. The results indicated that the density increase with the increase the number of layer. Lateral shrinkage is one of the important parameter for estimating the quality of component gradation in an FGM structure. The Vickers hardness show higher value at FGM7, Finally the FESEM images showed a gradation in microstructure within the system from plate- like structure for the hard ferrite to spherical structure for the soft ferrite.
One of the difficulties that the kindergarten institution face is the lack of specialized teachers to work with the children at the kindergarten age for the majority of this stage teachers were prepared to teaech in the elementary stage while the kindergarten child needs ateacher who is aware of the characteristics and the demands of his growth and his behavioral emotional and social problems.
Therefore the best teacher must be chosen for the kindergarten and qualifying her educationally in all that this qualifying includes of knowledge's.
The aims of the research:
The present research aims at the identification of the n
... Show MoreA particulate polymer composite material was prepared by reinforcing with the Aluminum Oxide (Al2O3) or Aluminum (Al) metallic particles with a particle size of (30) µm to an unsaturated Polyester Resin with a weight fraction of (5%, 10%, 15%, 20%).
Tensile test results showed the maximum value of elastic modulus reached (2400MPa.) in the case of reinforcing with (Al) particles with weight fraction (20%) and (1500 MPa.) in the case of reinforcing with (Al2O3) particles of the same weight fraction.
When the impact and the flexural strength tests were done, the results showed that flexural strength (F.S), maximum shear stress (τmax), impact strength
... Show MorePVC/Kaolinite composites were prepared by the melt intercalation method. Mechanical properties, thermal properties, flammability and water absorption percentage of prepared samples were tested. Mechanical characteristic such as tensile strength, elongation at break; hardness and impact strength (charpy type) were measured for all samples. It was found that the tensile strength and elongation at break of PVC composites decreased with increasing kaolinite loading. Also, the hardness of the composites increases with increase in filler content .The impact strength of the composites at the beginning increases at lower kaolinite loadings is due to the lack of kaolin adhesion to the matrix. However, at higher kaolin loadings. This severe agglom
... Show MoreWith the increasing reliance on microgrids as flexible and sustainable solutions for energy distribution, securing decentralized electricity grids requires robust cybersecurity strategies tailored to microgrid-specific vulnerabilities. The research paper focuses on enhancing detection capabilities and response times in the face of coordinated cyber threats in microgrid systems by implementing advanced technologies, thereby supporting decentralized operations while maintaining robust system performance in the presence of attacks. It utilizes advanced power engineering techniques to strengthen cybersecurity in modern power grids. A real-world CPS testbed was utilized to simulate the smart grid environment and analyze the impact of cyberattack
... Show MoreLinear programming currently occupies a prominent position in various fields and has wide applications, as its importance lies in being a means of studying the behavior of a large number of systems as well. It is also the simplest and easiest type of models that can be created to address industrial, commercial, military and other dilemmas. Through which to obtain the optimal quantitative value. In this research, we dealt with the post optimality solution, or what is known as sensitivity analysis, using the principle of shadow prices. The scientific solution to any problem is not a complete solution once the optimal solution is reached. Any change in the values of the model constants or what is known as the inputs of the model that will chan
... Show MoreThe current research involves psychological pressure (educational,environment andemotionly) for secondary level to 2013-2014.This research includes comparison among students who are trained and not trained in physical education .The sample is(126) students from each gender from first education.Al-Karkh and the research found out that physical education has an effect in lessing emotional and educational in a big degree in student in secondary which affect them positively in their study. &n
... Show MoreThe research aims to apply one of the techniques of management accounting, which is the Quality Function Deployment(QFD) on the Pepsi product in Baghdad Soft Drinks Company and to determine the technical requirements objectively that have been applied in practice in Baghdad Soft Drinks Company / a private shareholding company, as it focuses on meeting the quality requirements and achieving positive quality to provide a product It meets the requirements of current and future customers, hence the importance of research that indicates that the Quality Function Deployment(QFD) is a useful tool to develop the requirements of new products, being a design process driven by customers through their voices, and thus contribute to achieve a competi
... Show MoreBackground: The bonded orthodontic retainer constructed from multistrand wire and composite is an efficient esthetic retainer, which can be maintained long-term. Clinical failures of bonded orthodontic retainers, most commonly at the wire/composite interface, have been reported. This in vitro investigation aimed to evaluate the tensile forces of selected multistrand wires and composite materials that are available for use in the construction of bonded fixed retainers. Materials and Methods: The study sample includes 120 wires with three types of retainer wires (3 braided strands\ Orthotechnology, 8 braided strands\ G&H Orthodontics, 6 coaxial strands\ Orthoclassic wires), two types of adhesive (flowable\ Orthotechnology, non flowable\ G&H O
... Show MoreBackground: Calcium hydroxide and calcium-silicate materials used as direct pulp capping materials. The aims of this in vitro study is to compare among these materials in, the calcium ion release and pH change in soaking water after immersion of materials’ specimens in deionized water. Also Solubility and water sorption of materials’ specimens measured after soaking time. Calcium-silicate materials used were Biodentine, TheraCal and MTA Plus. Materials and methods: Four materials used in this study; Urbical lining (as control group), Biodentine, TheraCal and MTA Plus. Ten discs fabricated from each tested material, by using plastic moulds of 9 mm diameter and 1 mm thickness. Each specimen was immersed in 10 ml of d
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