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.
تقدمت احداث النصف الاخير من القرن الماضي من تاريخ العالم الاقتصادي صور كثيرة من التكتلات والاليات التعاونية والتشاركية القائمة على مصادر مختلفة للتجمع الاقتصادي من اهمها شكل الشراكات التجارية والاقتصادية ولها امثلة كثيرة على المستوى الاقتصادي الدولي ومنها الشراكة الاورومتوسطية التي تمثل منطقة حيوية في حسابات التبادل الدولي تجاريا وراسماليا ولكن هذا التشكيل التكتلي يحتاج الى وقفه تخص
... Show MoreIn fact, the main idea of the manuscript is to take note of a branch of Islamic jurisprudence, which is the science of jurisprudential jurisprudence and this manuscript in its title and subject dealt to the men of knowledge of jurisprudence because of its ambiguity calls for thinking, and the brainstorming mood to test the intelligence of jurisprudence, Of students of knowledge jurisprudence. This section contains (14) questions starting with the question (26) and ending with (39) in the doors of pray.
This study aims at investigating the partial Islamic rules of preparing and distributing cartoons in order to issue an overall Islamic rul. To reach an end, descriptive and analytical approaches are adopted to clarify the nature of cartoons and other related concepts. The researcher, as well, with reference to verses of the Holy Quran, tradition (Hadith) and Islamic jurists, adopts a deductive approach to issue Islamic rules related to the industry of cartoons and it's distribution
The study consists of three sections. The first Section addresses the following issues: Definition animation; and related wordy. The second Section: Origin of Cartoon's history and it's negative and positive effects. The third Section: Islamic rules related
This research is dealing with Islamic creed faith which would be the prophecy concept. The prophecies subject one greatest creed doors with God’s - high ranking – fortunate - messengers faith is one faith’s six pillars ; though no correct faith to adorer , until the adored completely faith in God’s angels , holly books
Dada la importancia de la gramática en las lenguas hemos tratado en esta investigación manifestar la importancia de la posición del adjetivo en la lengua castellana y hacer una simple comparación con la lengua inglesa y la lengua árabe.
Los comportamientos de los adjetivos en lo referente a su posición respecto del sustantivo no siguen una fórmula fija. En esta cuestión “no se trata de leyes, sino de tendencias”, como dice Gili Gaya1, la inmensa mayoría de los adjetivos del español son susceptibles de ser colocados antes o después del sustantivo al que sirvan de adjunto. Las formulaciones sobre el orden Sust.+Adj. o el orden Adj.+Sust., por muy genéricas que sean, sufren excepciones,según las preferencias contextualiz
An ancient iraq man lived under sever shadow which led him to be creative for providing instruments that ables him to keep his life with who are near to him, this matter led to appear humanity civilization
The research aims to introduce the elders of Imam Al-Ala who died in the year 761 AH. The study showed the prominent role of women in the eighth century AH in the sciences in general and in the hadith in particular. The woman did not depart from the call of divine education in the Almighty saying: Read in the name of your Lord who created * created mankind * created mankind * And your Lord, the Most Generous, who taught with the pen * taught man unless he knows the captive of verses 1-5.
Families in that era had a prominent role in this concern, especially parents. They were attending boys and girls since their childhood, the lessons of scholars, and the benefit of science, and they were
Abstract: Choosing suitable artificial teeth for partially edentulous patients and arranging these teeth in a way to look natural is difficult. An important factor in dentures construction is the mesiodistal width of anterior teeth, because a denture would not appearance natural if artificial teeth are of incorrect size. While for a successful orthodontic treatment, mesiodeistal width of teeth is important for space analysis and for establishing proper occlusion. The aim of this study is to determine the correlation between the average mesiodistal width of anterior and posterior teeth in male and female Iraqi population. 40 Iraqi subjects with normal occlusion participated in this study. Mesiodistal measurement of all teeth was carried out
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