The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlin

Background: This study evaluate the immunohistochemical expression profile of transforming growth factor beta-1 in inflamed gingival tissue of patients with gingivitis and chronic periodontitis compared to healthy subjects and, determine the correlation between this cytokine and the clinical periodontal parameters, intensity of inflammation and chronic periodontitis severity. Materials and methods: Gingival tissue specimens were taken from 23 chronic periodontitis patients, 20 gingivitis patients and 20 periodontally healthy subjects. The periodontal status was evaluated by dichotomous measurements of the clinical periodontal parameters (PLI, GI, BOP, PPD, CAL). The gingival specimens were fixed immediately in 10% formalin and processed ro

AbstractThe research aims to identify the impact of the different methods in calculating the Items sensitivity coefficient on the standard characteristics of the Criterion-Referenced test in the measurement and evaluation material. The research sample consisted of (35) male and female students, who were chosen by the intentional method. The researcher prepared learning-teaching program in constructing the content of the measurement and evaluation material for non-specialized departments, prepared an achievement test in its equivalent forms, identified the results of agreement between the methods used in analyzing the items of the criterion-referenced test, and compared the standard characteristics of the achievement test, both according to

Secure information transmission over the internet is becoming an important requirement in data communication. These days, authenticity, secrecy, and confidentiality are the most important concerns in securing data communication. For that reason, information hiding methods are used, such as Cryptography, Steganography and Watermarking methods, to secure data transmission, where cryptography method is used to encrypt the information in an unreadable form. At the same time, steganography covers the information within images, audio or video. Finally, watermarking is used to protect information from intruders. This paper proposed a new cryptography method by using thre

Background: This study was performed to compare the marginal fit changes and facture resistance of metal ceramic crowns constructed from Ceramill Sintron metal coping veneered with three different porcelain veneering materials (Vita Master Koromikos VMK, Willi Geller Creation CC and GC initial MC), also to evaluate the influence of thermocycling on load at fracture. Materials and Methods: Master brass die was scanned ,then metal coping was designed and milled from Ceramill Sintron blank to get 60 metal copings, then divided randomly into three groups(20 sample), then veneered with porcelain: VITA, Creation or GC. The marginal gaps were measured before and after porcelain veneering then marginal fit changes was calculated. Fracture resist

Some geological phenomena as landslides and the mobilization of the accumulated rocks or soil are discussed in this research by using projectiles that cause mobility and falling of these land masses which are present at the top of mountains and edges of roads and streets to avoid accidents and human disasters which will occur if they are left falling by effect of climate or vibrating factors that are produced by performing dams, bridges and reservoirs. According to the different divisions of land masses groups, primary and secondary, which depend on type of movement and material arrangement that form the mobile masses, this research had shown the effect of projectiles for every type of cannons on the mobility of every groups of these rocks