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The main aim of the current research is to calculate the optimum top roof length of windcatcher for enhancing the indoor air quality (IAQ) parameters such as (AAV) average air velocity, (AFR) air flow rate, (ACR)air change rate, (MAA) mean age of air and (ACE) air change effectiveness. This work assesses the effect of the top roof length of windcatcher on indoor natural ventilation in a tropical climate or dense urban areas. The research method was conducted through Autodesk CFD 2019 software for simulation purposes. The reference tested model is composed of a rectangular cuboid with 8 m length, 6 m width and 3 m height which represents a small model room for applying the numerical simulation and the windcatcher was combined with the room roof. The tested windcatcher form is a rectangular cuboid of 1.4 m length, 1 m width and 1.5 m height While the inlet and outlet are of windcatcher openings are 1 m by 1 m. The windcatcher simulation is aimed to determine the IAQ parameters for different 11 case studies with different top roof projection length ranges from 0 cm to 100 cm each 10 cm interval.The main results of these CFD simulations are presented the effect of the projection length of top roof of windcatcher on the parameters of natural ventilation performance. Based on the simulation, it can be concluded that the increasing of the top roof of windcatcher to 100 cm leads to increase the AAV with 10.5%, increase AFR with 190%, increase ACH with 11% at inlet. Also increase AVA with 14%, decrease MAA with 14% and increase ACE with 67% inside the tested model. Depending on the results, this paper suggests a regression equation that can predict the inlet and indoor average air velocity of different projection lengths for the tested model.

An Innovative Methodology for Achieving Compatibility between Heritage and Contemporary in Architecture (Case Study: Omani Architecture)Abstract: This paper presents an innovative methodology for achieving correlation between heritage and contemporaneity in architecture within analytical study of Omani buildings examples to explain the role of heritage in fulfilling the society needs of architectural design. It examines 3 main aspects: first aspect: Heritage - The study explains the different types of heritage as well as the importance of heritage for society, with an explanation of the various factors that effect on the formation of architectural and urban heritage, such as cultural, social, economic, legislative, educational, and technological factors.2nd aspect: Elements of Heritage – Here, the study classified the different needs of society from architecture and planning to four main needs: social, climatic, visual, and planning needs. These different needs require a set of architectural and planning solutions and treatments at the level of the general formation of the building, as well as at the planning level, these Solutions and treatments have produced heritage elements that are used down to generations3rd different trends of correlation between heritage and contemporaneity in architecture. Four key dimensions of society needs are identified and applied to the cases: planning; climatic; social; and visual requirements. The analytical study reveals that climatic and social requirements play most important role in contribution to molding the role of heritage in architectural design. Understanding such role and properties of heritage is essential for achieving urbanize and architectural correlation between what is inherited (architectural heritage) and what is imported (contemporary architecture) so that, the architectural and urbanize product reflects the uniqueness and derives its elements from Omani architectural heritage, while not lagging behind the civilized ride represented in contemporary

Coronavirus (COVID-19) has affected day to day human lifestyle and also is slowing down the global economy of all countries. This pandemic has affected thousands of peoples, who are either sick, sitting in hospitals or are being killed due to the spread of this disease. This viral infection has forced people to stay at home almost time, and doing the majority of life requirements from home, such as work, education, shopping, etc. and hence nowadays, the main task for architects is to improve the quality of environment inside different architectural spaces for helping the users to do their needs and from other side for protect them from this virus. Achieving natural ventilation is one of the most important tools, which helps improving the air quality and hence providing healthy spaces for reducing the viral infection. Good designing the air inlet is playing the main role of achieving the mentioned healthy environment. This paper, therefore, presents a detailed evaluation of the impact of the inlet openings variables on the ventilation performance of a single-zone isolated building. The evaluation is based on the induced airflow velocity.High-resolution coupled 3D steady Autodesk CFD simulations of cross-ventilation are performed for shape (rectangular and square shape); building slop angle (0, 15, 30,45,60,75 and 90 degree); Wall to Floor Ratio (WFR) (10, 15, 20%) and Wall to Wall Ratio (WWR) (20, 25, 30%) of inlet openings.The results show that using rectangular window shape coupled with building slop 0 degree and WWR 30% represent the maximum ventilation ratio inside building, while the square window shape represents an air flow ratio less than the rectangulr shape for the same window area, building slop degree, WFR and WWR. Additionally, the window shape effect on the variation in the airflow ratio of buildings with slope angel bigger than or equal 60 degree, is too small that it can be ignored.

الهدف من البحث هو دراسة وتحليل والتعين الدقيق للدفع المحورى علىالعضو الدوار فى الضواغط الطاردة المرکزية. نشرح العوامل التى تؤثر علىالدفع المحورى مثل زيادة الأحمال على ضاغط ثانى أکسيد الکربون عنأوضاع التشغيل التصميمية له . کما تتضمن العوامل تأثير وجود Fouling مع الغاز مما ينتج عنه تراکم على الأسطح الداخلية لدفاعات العضو الدوارفيتسبب فى زيادة الدفع المحورى وتقليل من أداء الضاغط . يتناول البحثشرح العلاقة مابين الدفع المحورى للعضو الدوارفى وجود نسبة Foulingمع الغاز فى خلال فترة زمنية محددة من بعد عمل عمرة کاملة لضاغط ثانىأکسيد الکربون . بعد الدراسة والتحليل نقف على کيفية تقليل الدفع المحورىعلى العضو الدوار وذلک بوضع اسطوانة اتزان على العضور الدوار لخلققوى معاکسة له تتناسب مع جميع الظروف التشغيلية لضاغط ثانى أکسيدالکربون بحيث أن الدفع المحورى للعضو الدوار بعدها لا يتعدى 50 % منحمل الکرسى. النتائج النهائية التى تم الحصول عليها: عند استخدام قطراسطوانة اتزان = 158.6686 mmt D تکون أعلى قيمة للدفع المحورى عنأوضاع التشغيل المختلفة للضاغط هى 93.193 % من حمل الکرسى. عنداستخدام قطر اسطوانة اتزان = 186.065 mmt D تکون أعلى قيمة للدفعالمحورى عن أوضاع التشغيل المختلفة للضاغط هى 73.35 % من حملالکرسى. عند استخدام قطر اسطوانة اتزان = 174.595 mmt D تکونأعلى قيمة للدفع المحورى عن أوضاع التشغيل المختلفة للضاغط هى41.22 % من حمل الکرسى مع وجود Fouling مع الغاز وعند أقصى حملللضاغط بعد العمرة فى عدم وجود Fouling مع الغازهى 0 % من حملالکرسى وهذا يعتبرأنسب قطر يستخدم لاسطوانة الاتزان (Balance drum)لان الدفع المحورى يکون أقل من % 50 من حمل الکرسى.Abstract: This article is a study, analysis, and determine accurately the axial rotor thrust for centrifugal compressors. Are explained the factors that affect axial rotor for carbon dioxide compressor during operating conditions. Also, the effect of the existence of fouling with gas, results in the accumulation of fouling on the internal surfaces of the impellers leading to an increase in axial rotor thrust and reduction of the performance of the compressor. The relationship between axial rotor thrust and fouling ratio with time is discussed after complete overhaul for the carbon dioxide compressor. The axial rotor thrust on the carbon dioxide compressor is reduced by placing balance drum on rotor of the compressor in the opposite direction of the axial force which is suitable for all operating conditions of the compressor. The resultant axial force didn’t exceed 50 % of rated bearing load, and the analysis method is then approved to be effective. The residual thrust load for high pressure rotor for the compressor before modification at design operating condition is equal to 13.68 % of rated bearing load, while at the high load without fouling effect for the compressor is equal to 58.47 % of rated bearing load and compressor with fouling effect is equal to 110.9 % of rated bearing load. When using the balance drum diameter Dt =158.6686 mm, the highest value of axial thrust force is equal to 93.193 % of rated bearing load. When using the balance drum diameter Dt =174.595 mm, the highest value of axial thrust force is equal to 41.22 % of rated bearing load. When using the balance drum diameter Dt =186.065 mm, the highest value of axial thrust force is equal to 73.35 % of rated bearing load.

Perhaps one of the most important measures of the quality of academic departments for information studies is the availability of a number of scholars who assume the role of leadership, leadership, scientific consolidation, and the formation of truly educated generations capable of giving sincerely. Dr. was Heshmat Qassem - may God have mercy on him - is one of those whose presence academic departments are proud of, including the Department of Libraries, Documents and Information at Cairo University, to which this man belongs.

The situation that the information sector is experiencing today makes it inevitable, and even very necessary, to keep pace with the rapid developments in the fields of technology in order to invest in the development and development of the professional, information and academic sectors of libraries, and to modernize the cognitive frameworks and structural aspects on which they are based. Today, information institutions, especially university libraries, are facing a wave of The phenomena are represented by a low level of influence, effectiveness, and activity, a lack of financial resources, the adoption of ineffective methods to achieve the desired goals, a low level of satisfaction among beneficiaries, and a low level of job satisfaction among employees. This situation is exacerbated by the presence of many administrative challenges facing university libraries in the third millennium. The most important of which is the knowledge management challenge. But the problem today still remains about the extent of Algerian university libraries’ readiness to enter the information society by adopting new concepts, especially knowledge management. If libraries find the best way to apply them, they will be able to achieve their goals and interact positively by providing good services to their beneficiaries. This is what prompted us to propose The following questions: How can we be exposed to the term knowledge management? What is the concept of knowledge management in Algerian university libraries? Is there a real adoption of the concept of knowledge management in Algerian university libraries? How can a future strategy be formulated for applying knowledge management in Algerian university libraries? To answer all these inquiries, this paper aims to present the theoretical framework on knowledge management in Algerian university libraries in light of a changing world, and to identify the extent to which there is a real understanding of this concept in our university libraries. We also developed a vision and a forward-looking future vision through the proposed action plan to activate the application of the concept of knowledge management. Knowledge as a new challenge for information institutions in Algeria in the coming decades.

The article addresses the situation that the information sector is experiencing today, which makes it necessary to keep pace with the rapid developments in the fields of technology in order to invest in the development and development of the professional, information and academic sectors of libraries, and to modernize the cognitive frameworks and the structural aspects on which they are based. Today, information institutions, especially university libraries, are facing a wave of phenomena represented by: In the low level of its influence, effectiveness and activity, a lack of financial resources, the adoption of ineffective methods to achieve the desired goals, and a low level of satisfaction among beneficiaries and the level of job satisfaction among employees. This situation is exacerbated by the presence of many administrative challenges facing university libraries in the third millennium, the most important of which is the challenge of... Total Quality Management.

A study on the role of curricula in the field of cataloging in preparing the cataloger in the electronic environment. The study presents recent developments in the field of cataloging in light of the electronic environment, then reviews cataloging curricula in seven library and information departments in Egypt, then presents the findings it has reached, and finally presents The study is a set of proposals and recommendations.

An applied study that aims to analyze the elements of metadata in the sites of a sample of Arab libraries in Egypt and Saudi Arabia. The study begins with a comprehensive methodological introduction that explains its importance and the approach followed, introduces the study population, and reviews Arab and foreign intellectual production on the subject. Then the study analyzes metadata using Meta Tag Analyzer program, and the study covered the following sites: the Library of Alexandria, the Egyptian Library Network, the Egyptian Library, King Fahd National Library, King Abdulaziz Public Library, and Mubarak Public Library.

A study on the standard communication format MARC 21 and the demand for its Arabization. It begins with a general definition of the MARC 21 format in terms of its origin and various forms, the components of recordings in it, and the benefits it achieves. It then reviews the various Arab efforts that called for its Arabization, and also presents the results and recommendations it reached. Arab studies demanding the Arabization of MARC 21.