The electrospun nanofibers membranes (ENMs) have gained great attention due to their superior performance. However, the low mechanical strength of ENMs, such as the rigidity and low strength, limits their applications in many aspects which need adequate strength, such as water filtration. This work investigates the impact of electrospinning parameters on the properties of ENMs fabricated from polyacrylonitrile (PAN) solved in N, N-Dimethylformamide (DMF). The studied electrospinning parameters were polymer concentration, solution flow rate, collector rotating speed, and the distance between the needle and collector. The fabricated ENMs were characterized using scanning electron microscopy (SEM) to understand the surface morphology and estimate the average fiber sizes. The membrane porosity percentage was measured using the dry-wet weight method. Also, a dynamic mechanical analyzer was used to determine the mechanical strength properties (tensile strength and Young's modulus) (DMA). The obtained results revealed that the polymer concentration and flow rate mainly affect the porosity and fiber size in ENMs. Increasing the polymer concentration improves the strength and flexibility, while the flow rate did not show a clear effect on the mechanical strength of ENMs. Both fibers collecting speed and spinning distance did not clearly impact the membrane morphology. ENMs flexibility significantly increased with increasing the collector speed and decreasing the spinning distance. Strong and flexible ENMs with small fibers can be fabricated using 10% PAN/DMF at a flow rate of 1 mL/h, collector speed of 140 rpm, and spinning distance of 13 cm.
In this research the subject of human ability to change, as it is proven in the Koran , which is proof of the argument against the ability of human change , whether the change in the positive or negative direction .
Here the limits of the research are limited to a study of analysis of human ability to change and this establishes the important of knowing that man has the ability while in the wrong way to change the path to the right path which Gifts and guidance .
The search required three demands and conclusion
- The first required :- is to try the idolaters to take out believers by right .
- The second required :- is to change what is inside the soul as a reason to enter blessings on man .
- The third required :- is good
نتيجة للتطور و انفتاح الاسواق الاقتصادية عالميا ظهرت اهمية الافصاح في القوائم المالية و اعدادهايكونمبني على ( العدالة و الشفافية ) في اظهار البنود الواردة فيها ، و لان هذه القوائم تعد لا كثر من جهة مستفيدة ( اصحاب المصلحة ) سواء كانوا مستثمرين او مقرضين او هيئات حكومية حيث يجب اعدادها بطريقة اكثر شفافية و بدون تحيز لجهة دون اخرى ،هدفت الدراسة الى التعرف على اهم الفروقات الضريبية المؤجلة التي تنشأ في الوحدات الا
... Show Moreالطائفية وتداعياتها على بناء الدولة العراقية المعاصرة
The globalization concept is regarded one of the modern concept which had seen in the last time while it hadn’t occur now only, but it had seen clearly with the technology &information revolution beside the quick development in the communication net which had made the world like a small village .
Since accounting is regarded business language based on integrated theoretical framework consists of many connected objective & rules which led to consistent accounting standards .
So with this development there is a clear need to consolidate the concepts , policies ,and applications which the companies use it in treating its financial events .
In pre- Islamic poetry, there are a lot of words that indicate
peacefulness of one sort of another, in addition to the inspirations of semantic
modeling in which the poet sets himself in various horizons.
Among these words: brother, comrade, friend, companion, lover,
people, prince, home, land, country, blessing, honesty, contract, company,
justice, thankfulness, forgiveness, pardoning, guest, goodness, faithfulness,
silence, death, peace,….
In addition, there are their derivatives from various aspects that indicate
peacefulness either directly or indirectly.
ان التحول في الحياة الاقتصادية الناتج عن التقدم التكنولوجي وتقنية المعلومات في مجالات الفضاء والتقدم في الاتصالات السلكية واللاسلكية والالكترونيات الدقيقة مكنت الشركات من ارسال كميات هائلة من البيانات بتكاليف منخفضة.
وان انتشار الشركات متعددة الجنسبة والتي سعت لتحقيق السيطرة على اقتصاديات العالم من خلال فروعها المنتشرة فتحتاج الى نظم للانتاج والتكاليف ونظم للمعلومات الادارية والمحاس
... Show Moreيهدف البحث إلى دراسة التحفظات على اتفاقية سيداو (الدول العربية أنموذجًا)، حيث يُعد نظام التحفظ على الاتفاقيات الدولية أحد المظاهر القانونية الحديثة في مجال العلاقات الدولية، والذي يقرّ بحق الدول في إبداء التحفظ على بعض أحكام الاتفاقيات الدولية، وفقًا للأحكام العامة التي حددتها المواد (19-23) من اتفاقية فيينا لقانون المعاهدات لعام 1969. وإذا كان حق الدول في التحفظ مكفولًا دوليًا، فإن الإشكالية القانونية تكمن في
... Show MoreThe current research deals with the specificity of the interior design of the classes of art education in the schools of excellence for the province of Muthanna and its center of the city of Samawah. In the first chapter، the problem of research was determined by the lack of internal spaces of the classes of art education to designs that meet the requirements and needs of students in these educational stages. The importance of the research in being an addition to knowledge in the field of interior design and engineering department of the general directorates of the Ministry of Education. The objectives of the research were determined through.
- Identifying the reality of the halls of art education for sch