An assembled pulsed Nd:YAG laser-robot system for spot welding similar and dissimilar metals is presented in this paper. The study evaluates the performance of this system through investigating the possibility and accuracy of executing laser spot welding of 0.2 mm in thickness stainless steel grade AISI302 to 0.5 mm in thickness low carbon steel grade AISI1008. The influence of laser beam parameters (peak power, pulse energy, pulse duration, repetition rate, and focal plane position on the final gained best results are evaluated. Enhancement of the experimental results was carried by a computational simulation using ANSYS FLUENT 6.3 package code.
أهمية البحث والحاجة إليه:
من مظاهر التواصل الحضاري في جانبه العلمي والتكنولوجي هو متابعة أبناء مجتمعنا ولاسيما الشباب لكل منجز حديث واتخاذه وسيلة للحصول على المعلومات والمعرفة والتسلية، بحيث أصبح هذا التعامل ممارسة يومية حياتية، وهذا دليل على مدى تفتح ذهنية وعقلية ورغبات أبنائنا ومواكبتهم لروح العصر ومتطلباته وتعبيراً صادقاً عنه فضلاً عن إشغال أوقات ف
... Show Moreتناول البحث دراسة خمسة نصوص مسمارية لقروض غير منشورة من سلالة أور الثالثة وتحليلها وترجمتها وهي من مجموعة المتحف العراقي, يعود تاريخها الى زمن سلالة أور الثالثة (2012-2004ق.م) تحديدا الى زمن الملكين شوسين (2037- 2029ق.م) وابي سين (2028-2004 ق.م), اما مضامينها فهي قروض بمادتي الشعير(ثلاثة نصوص) الفضة (نصان), والقروض على نوعين قروض بفائدة (ur5 - ra), وقروض بدون فائدة (maš2 - nu - tuk), وقد حددت نسبة الفائدة في القروض 1/3 33% لمادة الشعير و20% لما
... Show MoreThis study is about finding the estimation of tow equations, the comparative has been done between the estimations by using seemingly unrelated regression equations for the variable and random error has been distribution with poisson and the variable and random error has been distribution with normal and the method by using oldenary lest square.
While in the application side, we have estimated the parameter of investment specification function for the sector of agriculture with the industry sector is enabled us to obtain an estimation efficiency for the model of seemingly unrelated Poisson regression equation.
المستخلص
شهدت معظم المدن السومرية أزدهاراً أقتصادياً خلال عصر أور الثالثة ،أنعكس ذلك من خلال النصوص المسمارية المكتشفة ذات المضامين الاقتصادية المتنوعة ومنها (وصولات تسلم Bullae) التي تميزت بعصر أور الثالثة بأشكالها المتعددة ومنها: الكروية والمربعة والمستطيلة والمثلثة والمضلعة ومعظمها يحتوي على طبعات أختام فضلاً عن أنها تكون مثقوبة طولياً لغرض التعليق.
The issue of volunteerism is one of the most important issues that have become prominent in social sciences and contemporary social thought, especially as a result of the transformations and changes that the world undergoes today. The voluntary sector has become the concern of all societies and governments for its development and service to society and various sectors. The practice of women is prominent in the work of volunteerism after 2003 in Iraq, but its work face a number of obstacles and hindrance. The problem of research is the obstacles of women's work in non-governmental organizations. The research aims to identify the nature and characteristics of volunteer work of Iraqi women. &nb
... Show MoreSeveral attempts have been made to modify the quasi-Newton condition in order to obtain rapid convergence with complete properties (symmetric and positive definite) of the inverse of Hessian matrix (second derivative of the objective function). There are many unconstrained optimization methods that do not generate positive definiteness of the inverse of Hessian matrix. One of those methods is the symmetric rank 1( H-version) update (SR1 update), where this update satisfies the quasi-Newton condition and the symmetric property of inverse of Hessian matrix, but does not preserve the positive definite property of the inverse of Hessian matrix where the initial inverse of Hessian matrix is positive definiteness. The positive definite prope
... Show MoreBackground: Temporomandibular joint (TMJ) is a compound articulation formed from the articular surfaces of the temporal bone and the mandibular condyle.CBCT imaging of TMJ is that it allows accurate measurements of the volume and surface of the condyle. The aim of the study is to assess the sagittal position of mandibular condyle in patients with temporomandibulardysfunction using Cone Beam Computed Tomography in centric occlusion. Materials and Methods: CBCT images for all patients were obtained in an upright position using New Tom Giano CBCT with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors was changed accordingly using NNT version 5.1 software for sagittal reconstruction, anterior, superior and posterior
... Show Moreالناصر، عامر عبد الرزاق عبد المحسن والكبيسي، صلاح الدين عواد كريم. 2018. إمكانية تبني الحوسبة السحابية الهجينة في الجامعات العراقية : دراسة تحليلية باستخدام أنموذج القبول التكنولوجي. مجلة الإدا
This research focuses on improvement of the corrosion behaviour of commercial pure titanium (Ti) grade II when exposed to Hank’s solution through different surface treatments. The disc shape of titanium samples were constructed to be divided according to their surface treatment. The first experimental group the Ti sample was exposed to computer numerical control (CNC) fiber laser machine. Whereas, the other experimental group the Ti sample was only coated with Polyetherketon keton (PEKK) by using carbon dioxide (CO2) laser technique while the last experimental group the Ti sample was treated with CNC fiber laser followed by PEKK coating by using CO2 laser technique. All were compared with the untreated control group. The electrochemical a
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