Abstract

The study of oxygen mass transfer was conducted in a laboratory scale 5 liter stirred bioreactor equipped with one Rushton turbine impeller. The effects of superficial gas velocity, impeller speed, power input and liquid viscosity on the oxygen mass transfer were considered. Air/ water and air/CMC systems were used as a liquid media for this study. The concentration of CMC was ranging from 0.5 to 3 w/v. The experimental results show that volumetric oxygen mass transfer coefficient increases with the increase in the superficial gas velocity and impeller speed and decreases with increasing liquid viscosity. The experimental results of k_la were correlated with a mathematical correlation des

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

تناول 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

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 cuneiform texts considered one of the most important resources which play an important role help us to know how was the economic , politic and religious manner and every thing have relation of the history of Mesopotamia which contain many of information that enrich our knowldgement every side of Mesopotamia civilization since using writing as away to register the science and human knowldgement . The city of Sippar (Abu –Habba ) was one of most important city of ancient Mesopotamia which mentioned as one of first five Mesopotamian cities found before floating and it exposed through excavating rich one of them tablet which some of it dated to old Babylon period . The king Ammi-Saduqa has a big share of tablet we study number of thi

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

This 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

This study identifies the contribution of some positive variables (happiness, optimism, and hope) to the level of psychological health in the practitioners of the nursing profession in Algeria, a total of (38) male and female nurses were employed as research sample. The researcher used a scale to measure happiness, optimism, hope, and psychological health. The results showed that the level of psychological health varies depending on the positive variables (happiness, optimism), as well as it depends on the variables of gender and professional Experience.

This article proposes a new strategy based on a hybrid method that combines the gravitational search algorithm (GSA) with the bat algorithm (BAT) to solve a single-objective optimization problem. It first runs GSA, followed by BAT as the second step. The proposed approach relies on a parameter between 0 and 1 to address the problem of falling into local research because the lack of a local search mechanism increases intensity search, whereas diversity remains high and easily falls into the local optimum. The improvement is equivalent to the speed of the original BAT. Access speed is increased for the best solution. All solutions in the population are updated before the end of the operation of the proposed algorithm. The diversification f

This work deals with determination of optimum conditions of direct diffusion bonding welding of austenitic stainlesssteel type AISI 304L with Oxygen Free High Conductivity (OFHC) pure copper grade (C10200) in vacuum atmosphere of (1.5 *10^-5 mbr.). Mini tab (response surface) was applied for optimizing the influence of diffusion bonding parameters (temperature, time and applied load) on the bonding joints characteristics and the empirical relationship was evaluated which represents the effect of each parameter of the process. The yield strength of diffusion bonded joint was equal to 153 MPa and the efficiency of joint was equal to 66.5% as compared with hard drawn copper. The diffusion zone reveals high microhardness than coppe