تعد فعالية دفع الثقل واحده من الفعاليات المميزة بألعاب القوى، وهي أحدى فعاليات الرمي الأربعة (رمي الرمح, رمي القرص, أطاحة المطرقة, دفع الثقل) وتطلب قدرات بدنية وقابليات حركية خاصة والتي تعتمد بشكل فعَال ومؤثر على النواحي البايوميكانيكية, خصوصا عندما يتعلق الأمر بذوي الأعاقة ومنهم فئة (40f) والذين يتمتعون بدعم كبير من المجتمع الدولي بصورة عامة وفي بلدانهم بصورة خاصة وأمكانية تطوير أنجازاتهم لرفع أسم بلدانهم في المحافل الدولية. وتبرز أهمية البحث من خلال تحليل المسار الحركي لبطل العالم العراقي جراح نصار من خلال تحليل بعض المؤشرات البايوميكانيكية لمرحلة وضع القوة (تجهيز القوة) والتي تعتبر من اهم المراحل الفنية المؤثرة بالانجاز النهائي للاعبي دفع الثقل من الزحلقة أن كانوا أسوياء أم من ذوي الإعاقة.وتمحورت مشكلة البحث حول أهمية التعرف على القيم الرقمية للمؤشرات الميكانيكية لأبطالنا الذين حققوا كم من المداليات الملونة لوصف نتائجهم لمدربيهم وزملائهم للعمل على الوصول الى هذه الجزيئات وتطبيقها في تحسين الآداء الفني ورفع مستواهم أضافة الى أهمال الجانب البايوميكانيكي لهذه الفعالية من خلال عدم أستعمال التحليل الحركي والتعرف على نقاط الضعف بدقة عالية في فعالية سريعة لايتجاوز زمن المحاولة فيها الثانيتين أضافة الى عدم الاهتمام من قبل المدربين بخصائص قيم المؤشرات البايوميكانيكية المؤثرة في بعضها البعض لكي يبرمجوا برامجهم التدريبية بغية تحقيق أهدافهم بأسرع مايمكن وتوفيرا للجهد والوقت المبذول.وهدف البحث إلى التعرف على أهم المؤشرات البايوميكانيكية الخاصة بمرحلة وضع القوة وهي طول الخطوة لقدم الأرتكاز وزمن الخطوة لقدم الأرتكاز وسرعة الخطوة لقدم الأرتكاز وزاوية الأسناد وزاوية الدفع وزاوية اتجاه القدم الخلفية في وضع القوة والعلاقة بين هذه المؤشرات مع الإنجاز المتحقق للاعبي ذوي الاعاقة فئة (40f) بدفع الثقل.وأستعملت الباحثتان المنهج الوصفي والعلاقات الأرتباطية في دراستهما الحالية لملائمته طبيعة مشكلة الدراسة وتألف مجتمع البحث من لاعب المنتخب الوطني العراقي فئة (40f) (جراح نصار) أذ تم أخذه بالطريقة العمدية وأجري الأختبار له خلال معسكره التدريبي ببغداد في ملعب كلية التربية البدنية وعلوم الرياضة / الجادرية أستعدادا للبطولات الخارجية وتم أخذ ستة محاولات كما في السباقات الرسمية وتم أستعمال كامرتي تحليل نوع (CASIO FH13.5) بسرعة 120 لقطة بالثانية وتم أجراء عملية التحليل الحركي ببرنامجي التحليل Tracker)) و( Kenova ) أذ تم أستعمال برنامج Tracker)) لقياس المسافات والازاحات والأرتفاعات المتحققة وتم أستعمال برنامج(Kenova) لقياس السرعة والتعجيل والأزمان المتحققة لعينة الدراسة وبعد تحليل ومناقشة النتائج توصلت الباحثتان الى وجود علاقة أرتباط طردية بين طول الخطوة لقدم الأرتكاز وسرعة الخطوة لقدم الأرتكاز علاقة أرتباط عكسية بين زمن الخطوة لقدم الأرتكاز والإنجاز وعدم وجود علاقة أرتباط بين زاوية الأسناد وزاوية الدفع وزاوية اتجاه القدم الخلفية مع الأنجاز وفي ضوء ذلك توصي الباحثتان باجراء دراسات موسعه لهذه الفعالية لتشخيص نقاط الضعف والقوه في الأداء الفني والاهتمام بالجانب البايوميكانيكي من قبل المدربين والتأكيد على وضع القوة
The paper presents an original method to make the geometric synthesis of the rotary cam and translated tappet with roll. Classical method uses to the geometric synthesis and the reduced tappet velocity, and in this mode the geometric classic method become a geometric and kinematic synthesis method. The new geometric synthesis method uses just the geometric parameters (without velocities), but one utilizes and a condition to realize at the tapped the velocities predicted by the tapped movement laws imposed by the cam profile. Then, it makes the dynamic analyze for the imposed cam profile, and one modify the cam profile geometric parameters to determine a good dynamic response (functionality). In this mode it realizes the dynamic synthesis
... Show MoreThe aim of this paper is the study of the influence of magnetic field on unsteady
flow of the second-grade fluid with constant viscosity. The equations which
controlled this type of fluid flow are complicated, so finding an analytical solution is
not easy, because it is a system of partial differential equations.We obtained an
expression for the velocity by using homotopy analysis method HAM.
It is found that the equations motion are controlled by many dimensionless
parameter, namely magnetic field parameter M and material constant α,
dimensionless film thickness β and unsteadiness parameter S.We have been studied
the influence of all the physical parameters, that mentioned above on the velocity
field, also a
The effects of the permeation cement grout with fly ash on the sandy soil skeleton were studied in the present work in two phase; first phase the shear strength parameters, and the second phase effect of these grouted materials on volume grouted zone by injection (51) cm³ of slurry in sandy soil placed in steel cylinder model with dimension 15 cm in diameter and 30 cm in height. The soil sample was obtained from Karbala city and it is classified as poorly graded sand (SP) according to USCS. The soil samples were improved by cement grout with three percentages weight of water cement ratio (w:c); (0.1w:0.9c, 0.8w:0.2c, and 0.7w:0.3c), while the soil samples were dehydrated for one day
... Show MoreIn this research the behavior of reinforced concrete columns with large side openings under impact loads was studied. The overall cross sectional dimensions of the column specimens used in this research were (500*1400) mm with total height of (14000) mm. The dimensions of side openings were (600*2000) mm. The column was reinforced with (20) mm diameter in longitudinal direction, while (12) mm ties were used in the transverse direction. The effect of eccentric impact loads on the horizontal and vertical displacement for this column was studied. &
... Show MoreE-learning has recently become of great importance, especially after the emergence of the Corona pandemic, but e-learning has many disadvantages. In order to preserve education, some universities have resorted to using blended learning. Currently, the Ministry of Higher Education and Scientific Research in Iraq has adopted e-learning in universities and schools, especially in scientific disciplines that need laboratories and a spatial presence. In this work, we collected a dataset based on 27 features and presented a model utilizing a support vector machine with regression that was enhanced with the KNN method, which identifies factors that have a substantial influence on the model for the type of education, whether blended or traditiona
... Show MoreIn this paper, a robust adaptive sliding mode controller is designed for a mobile platform trajectory tracking. The mobile platform is an example of a nonholonomic mechanical system. The presence of holonomic constraints reduces the number of degree of freedom that represents the system model, while the nonholonomic constraints reduce the differentiable degree of freedom. The mathematical model was derived here for the mobile platform, considering the existence of one holonomic and two nonholonomic constraints imposed on system dynamics. The partial feedback linearization method was used to get the input-output relation, where the output is the error functions between the position of a certain point on the platform
... Show MoreThe need for optical fibers has emerged for its ability to transmit information with less attenuation and over long distances. In this work, four optical fibers with core radii from 1 μm to 4.75 μm in steps of 1.25 μm and a numerical aperture of 0.17 were studied and their modes properties have been calculated at a wavelength of 633 nm by using RP Fiber Calculator (free version 2022). Also, the effect of increasing the core radius on these properties has been studied. Multimode fibers can be obtained when the radius of the fiber core is large compared to the operating wavelength of the fiber which is less than the cutoff wavelength of the mode. Otherwise, a single-mode fiber is obtained. It has been concluded that all the calculated p
... Show MoreI
In this study, optical fibers were designed and implemented as a chemical sensor based on surface plasmon resonance (SPR) to estimate the age of the oil used in electrical transformers. The study depends on the refractive indices of the oil. The sensor was created by embedding the center portion of the optical fiber in a resin block, followed by polishing, and tapering to create the optical fiber sensor. The tapering time was 50 min. The multi-mode optical fiber was coated with 60 nm thickness gold metal. The deposition length was 4 cm. The sensor's resonance wavelength was 415 nm. The primary sensor parameters were calculated, including sensitivity (6.25), signal-to-noise ratio (2.38), figure of merit (4.88), and accuracy (3.2)
... Show MoreFluid-structure interaction method is performed to predict the dynamic characteristics of axial fan system. A fluid-structure interface physical environment method (monolithic method) is used to couple the fluid flow solver with the structural solver. The integration of the three-dimensional Navier-Stokes equations is performed in the time Doman, simultaneously to the integration of the three dimensional structural model. The aerodynamic loads are transfer from the flow to structure and the coupling step is repeated within each time step, until the flow solution and the structural solution have converged to yield a coupled solution of the aeroelastic set of equations. Finite element method is applied to solve numerically
... Show MoreAbstract
One of the major components in an automobile engine is the throttle valve part. It is used to keep up with emissions and fuel efficiency low. Design a control system to the throttle valve is newly common requirement trend in automotive technology. The non-smoothness nonlinearity in throttle valve model are due to the friction model and the nonlinear spring, the uncertainty in system parameters and non-satisfying the matching condition are the main obstacles when designing a throttle plate controller.
In this work, the theory of the Integral Sliding Mode Control (ISMC) is utilized to design a robust controller for the Electronic Throttle Valve (ETV) system. From the first in
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