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 nonlinear material properties as well as heat transfer conditions such as heat losses due to convection and thermal contact conductance between the workpiece and the backing plate interface on the thermal history. To validate the computational model results, an experimental procedure was carried out to measure temperature history on both sides of the specimen as well as the plunging force throughout the whole process time. The results obtained showed that symmetrical temperature distribution throughout the workpiece width was distinguished, implying that the tool rotation has a minor effect on the final temperature distribution. In addition, asymptotic V shape with high gradient temperature value in the weld nugget region after the full plunging was distinguished. Mechanical stresses and related plastic deformations generated, while achieving the FSW samples were evaluated in addition to the tool reaction force and heat generated to protect against tool failure.
Objective: The present study was aimed to develop a pH-triggered in situ gel for local release of lidocaine hydrochloride (lidocaine HCL) in the buccal cavity to improve the anesthetic effect of this amino amide drug which has very high water solubility. The formulations were introduced to the oral cavity as a spray to improve compliance and for easier administration.Methods: In this work, two grades of carbopol (934 and 940)-based in situ gel spray were designed. The formulations containing lidocaine HCl 5% were prepared by mixing different concentrations of carbopol with xanthan gum. Eight formulations were investigated and evaluated for gelation capacity, spray angle, volume of solution delivered per each actuation, rheological p
... Show Moreالغرض من هذا العمل هو دراسة الفضاء الإسقاطي ثلاثي الأبعاد PG (3، P) حيث p = 4 باستخدام المعادلات الجبرية وجدنا النقاط والخطوط والمستويات وفي هذا الفضاء نبني (k، ℓ) -span وهي مجموعة من خطوط k لا يتقاطع اثنان منها. نثبت أن الحد الأقصى للكمال (k، ℓ) -span في PG (3،4) هو (17، ℓ) -span ، وهو ما يساوي جميع نقاط المساحة التي تسمى السبريد.
A three-stage learning algorithm for deep multilayer perceptron (DMLP) with effective weight initialisation based on sparse auto-encoder is proposed in this paper, which aims to overcome difficulties in training deep neural networks with limited training data in high-dimensional feature space. At the first stage, unsupervised learning is adopted using sparse auto-encoder to obtain the initial weights of the feature extraction layers of the DMLP. At the second stage, error back-propagation is used to train the DMLP by fixing the weights obtained at the first stage for its feature extraction layers. At the third stage, all the weights of the DMLP obtained at the second stage are refined by error back-propagation. Network structures an
... Show MorePraise be to God, who started his book with the praise of himself and prayers and peace be upon those who have no prophet after him and his family and companions and those who followed them with charity until the Day of Judgment.
For it is known to every researcher in jurisprudence and its origins that the semantics in terms of formulas for assignment are divided into an order and a prohibition, and I have seen it necessary to write a small research on the prohibition, and since this topic is complex, and has a great impact on the difference of scholars, I decided to write on one issue of it And it is the absolute prohibition and its effect on the difference of jurists, and what is meant by the absolute p
This work implements the face recognition system based on two stages, the first stage is feature extraction stage and the second stage is the classification stage. The feature extraction stage consists of Self-Organizing Maps (SOM) in a hierarchical format in conjunction with Gabor Filters and local image sampling. Different types of SOM’s were used and a comparison between the results from these SOM’s was given.
The next stage is the classification stage, and consists of self-organizing map neural network; the goal of this stage is to find the similar image to the input image. The proposal method algorithm implemented by using C++ packages, this work is successful classifier for a face database consist of 20
... Show MoreAbortion is a condition that occurs due to one of the pathological injuries, often one of the members of the TORCH is the real cause. The current study aimed to investigate the impact of toxoplasmosis, HSV-2 infections with abortion, and also, the identification of immunogenetics marker (interleukin-10) that may be associated with abortion. Anti-Toxoplasma IgG, IgM, Herpes simplex virus-2 IgM, human soluble leukocyte antigen class I–G and interleukin10 were estimated by ELISA technique, while the expression of IL-10 gene was investigated by using the real-time PCR. The results showed that among aborted women the rate of anti-Toxoplasma and HSV-2 IgM antibodies occurred within the age groups (21–30) years and (31–40) years 32(100.0%) a
... Show MoreBackground/Aim: Endometrial abnormalities represent a diagnostic challenge due to overlapping imaging features with normal endometrium. Aim of this study was to assess accuracy of dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging (MRI) in evaluation of endometrial lesions in comparison with T2 and to assess local staging validity and degree of myometrial invasion in malignancy. Methods: Forty patients with abnormal vaginal bleeding or sonographic thickened endometrial were recruited. MRI examination of pelvis was per-formed using 1.5 T scanner with a pelvic array coil. Conventional T1-and T2, dynamic contrast-enhanced (DCE) sequences and diffusion-weighted image (DWI) were performed. Results: Mean age of pa
... Show MoreThe snthesis and characterization of cobalt(II), nickel(II), copper(II) and zinc(II) complexes of azo ligand 4-[(5-acetyl-2-aminophenyl)- diazenyl]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one derived from 4-aminoantipyrine and 4-aminoacetophenone are reported. The nature of the compounds have been studied followed by mole ratio and methods of continuous contrast, Beer′s law followed during a condensation rate (1 × 10-4 – 3 × 10-4 M). The analytical data showed that all the complexes are in 1:2 metal-ligand ratio. An octahedral geometry have been suggested for all the compounds and biological studies of all the complexes were evaluated against different types of antimicrobial strains.
Prostate cancer is an important and potentially fatal disease in humans. Both genetic and environmental risk factors are associated with increased risk of prostate cancer among Asian pop