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The effect of superficial gas velocity within the range 0.01-0.164 m/s on gas holdup (overall, riser and down comer), volumetric oxygen mass transfer coefficient, liquid circulation velocity was studied in an internal loop concentric tubes airlift reactor (working volume 45 liters). It was shown that as the usg increases the gas holdup and also the liquid circulation velocity increase. Also it was found that increasing superficial gas velocity lead to increase the interfacial area that increases the overall oxygen mass transfer coefficient. The hydrodynamic experimental results were modeled with the available equations in the literature. The predicted data gave an acceptable accuracy with the empirical data.
The final
... Show MoreResumen:
La traducción de los dos verbos ser y estar no es una tarea tan simple como piensan muchas personas, sino es una de las complicadas y difíciles tareas, ya que el traductor tiene que saber y perfeccionar los correctos casos gramaticales relacionados con esos dos verbos auxiliares tanto el verbo ser como el verbo estar, especialmente en la frase nominal para que pueda dar una clara y correcta traducción. Usados con el mismo adjetivo, "ser" comunicará una cualidad que es parte de la identidad o naturaleza del sujeto, mientras que "estar" comunicará un estado o circunstancia del mismo. Este e
... Show MoreThis research deals with and which was entitled: relationship between psychological time and elements of filming expression (one-day event filmsas an example). It is about the relationship of psychological time (internal) with the elements of filming expression and how the time affected when using these elements in terms of its deceleration or acceleration. In particular, this research focus on elements that slow down time or stops it when using these elements. As one day time is short and heavy at the time of spectators in terms of the large number of film events which makes the viewer runs out of breath to understand the nature of those events and then identify the causes and consequences, as they occur in a short time (one day time) a
... Show MoreObjective: To assess of Science Teachers' Awareness towards Communicable Diseases Control in Baghdad City
Primary Schools
Methodology: A descriptive study was conducted, included (100) primary school, (50) in Al-Rassafa sector, and
(50) in Al-Karkh sector, from March 5th 2012 to March 15th 2013, to assess of science teachers' awareness
towards communicable diseases control. A cluster sample of (100) Science teachers (males and females) were
selected, as one teacher from each school. A questionnaire format was used for data collection. The validity of
questionnaire was estimated through a penal of experts related to the field of study, and its reliability was
estimated through a pilot study conducted in (20) schools (
The proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.
In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete
... Show MoreTo ensure fault tolerance and distributed management, distributed protocols are employed as one of the major architectural concepts underlying the Internet. However, inefficiency, instability and fragility could be potentially overcome with the help of the novel networking architecture called software-defined networking (SDN). The main property of this architecture is the separation of the control and data planes. To reduce congestion and thus improve latency and throughput, there must be homogeneous distribution of the traffic load over the different network paths. This paper presents a smart flow steering agent (SFSA) for data flow routing based on current network conditions. To enhance throughput and minimize latency, the SFSA distrib
... Show MoreThis paper represents an experimental study on the application of smart control represented by the use of the fuzzy logic controller. Two-link flexible manipulators that are used in airspace and military applications are made of flexible materials characterized by low frequency and damping ratio. To solve this problem, this paper proposes the use of smart materials (piezoelectric transducers), where each link is bonded with a pair of piezoelectric transducers that act as a sensor and another as an actuator. As the arm vibrates because of the movement generated by the motor, this voltage is controlled by a regulator inside the LABVIEW® 2020 software and sends the output control voltage to the piezoelectric actuator. Experimental results
... Show Moreمشكلة دارفور من المشاكل الازلية التي تهدد كيان الوحدة السودانية
يهدف البحث إلى تحليل إمكانية استثمار الغاز الحيوي الناتج من مشاريع تصفية المياه العادمة في جنوب بغداد بوصفه مصدرًا متجددًا لإنتاج الطاقة الكهربائية ، مع التركيز على غاز الميثان بوصفه المكوّن الرئيس ذي القيمة الحرارية العالية . اعتمدت الدراسة على القياسات الميدانية لتراكيز غاز الميثان في مشروعي الرستمية والكرخ الرئيسية خلال فصلي الشتاء والصيف ، مع مقارنة القراءات بين مراحل المعالجة المختلفة، ابتداءً من ال
... Show Moreلقد ألقت أزمة جائحة كورونا بظلالها على قطاع التعليم بصورة عامة، والتعليم العالي بصورة خاصة؛ إذ دفعت اغلب الجامعات والقطاعات التعليمية التابعة لها لإغلاق أبوابها او العمل فيها بصورة متقطعة، وذلك حفاظا على سلامة الموظفين والتدريسيين والطلبة من الإصابة بمخاطرها التي بات انتشارها يشكل وعلى الرغم من أهمية تكنولوجيا المعلومات والتعليم الالكتروني في التعليم الجامعي، الا ان ذلك التعليم المتمثل باستخدام مختلف تك
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