The Management of Characteristics of the New Two-layer Rubber Matrix Seals

Rubber seals for closing devices operating in cold climates degrade quickly in aggressive environments at very low temperatures. As a result, leaks and failures occur in the closure devices. Therefore, there is a great need to develop a new model of rubber seals and develop their scientific basis. The article is devoted to increasing the sealing effect of rubber seals of machines and equipment, including closures, by introducing the anisotropy of the rubber matrix into its structure with control of the characteristics of hard closures obtained from rubber. For this purpose, new models of the gate valve design were obtained and new models of two-layer panel seals based on a modified rubber elastomer matrix are applied to these structures. For this, a test program is carried out in the form of an analytical trajectory of large, medium and small constant curves in two closed forms based on characteristic deformations to study the anisotropy of matrix deformations. It is found that the eigenvector of the deformation anisotropy of the matrix is not in the load trajectory before it collapses, it arises with a delay. This delay slows down the rate of destruction. This property of deceleration of the main eigenvector of the deformation anisotropy of the matrix is subjected to a very complex loading of the initial fields, in the latter sections it is also observed in samples No. 2, No. 3, tested along the trajectory of linear loading. This delay slows down the destruction rate. Thus, the direction of the deceleration property of the main eigenvector can be considered quite common. This leads to an increase in its resistance to wear in a highly aggressive environmen

دور التلقيح الاصطناعي غير المناسب على العقم والإسقاط في البقر في منطقة البصرة - العراق: دراسة ميكرو بيولوجية

A prospective study was performed to demonstrate the infectious causes and their mode of transmission in cases of infertility and abortion in cows. There were 434 artificially inseminated cows, of which 155 (35.7%) did not conceive after several trials. Seventy cows were naturally inseminated, of which 30 (42.8%) did not conceive. Delayed oestrus after normal delivery was found in 398 (99%) of 402 cows. Many microorganisms, known to be causative agents of infertility and abortion in cows, were recovered from uterine specimens, frozen semen and instruments of artificial insemination (AI). Pasteurella aerogenes alone was isolated from a uterine culture of one aborted cow. This organism was also isolated from three samples of frozen semen and from an instrument of AI. This microorganism has not been reported previously as a causative agent of abortion or infertility. It is concluded that the recovered pathogens could be transmitted from contaminated AI instruments or from frozen semen to healthy cows. Therefore, it is recommended to make routine culture and direct microscopical examination of semen that are used for AI and excluding or treating the infected bulls. Sterilization of AI instruments should also be performed routinely before each use.دراسة استشرافية أجريت لإظهار المسببات المعدية وطرق انتقالها في حالات العقم والإسقاط في الأبقار. لقد أجرى التلقيح الاصطناعي إلى 434 بقرة ، وقد فشل الحمل في 155 (%35.7 ) حالة منها بعدة عدة محاولات من وكذلك وجد تأخر الدورة التروية بعد الولادة الطبيعية في 398 (99%) من مجموع 402 بقرة. لقد تم عزل عدة أحياء مجهرية معروفة بتسببها للعقم والإسقاط في الأبقار من عينات الرحم والسائل المنوي المجمد ومن أجهزة التلقيح الاصطناعي. تم عزل جرثومة باستوريلا ايروجيتر لمفردها من عينة رحم لبقرة واحدة بعد الإجهاض مباشرة. وكذلك فان هذه الجرثومة تم عزلها من ثلاث عينات من السوائل المنوية المجمدة ومن احدى أجهزة التلقيح الاصطناعي. يستنتج من هذه إن هذه الجرثومة غير المسجلة سابقا بكونها تسبب الإسقاط أو العقم . الدراسة بأن الجراثيم المرضية ممكن أن تنتقل إلى الأبقار السليمة بواسطة أجهزة التلقيح الاصطناعي الملوثة أو بواسطة السائل المنوي الملوث. لذلك فانه يوصي بإجراء زرع جرثومي روتيني وفحص مجهري مباشر للسائل المنوي الذي يستخدم للتلقيح الاصطناعي مع استثناء أو علاج الثيران التي تظهر فيها الإصابة بالأمراض. وكذلك تعقيم أجهزة التلقيح الاصطناعي بضورة روتينية قبل كل استعمال