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.
Construction is the opening of the important pillars of the construction of the film as a whole for this, we find that the first of any narrative of my film begin at the borders of this construction is the window that we look through the contents tale and puzzle narrative is of significance that degrade traveler when reservoirs expression later in reasoning and find justifications ills that came by those initiation, this initiation may be the window that lead us to the core, understanding the story through signals received to the recipient to sail because of the paths of pickling what is which is encoded, but this initiation may serve as keys that understanding the be puppies and signals that beset and surrounded to what He holds inevita
... Show MoreEarthquakes in the Holy Qur’an and the Hadith of the Noble Prophet, an intellectual approach
Intellectual property rights of all kinds، and their nature، are considered a tool in the hands of their owner that enables him to monopolize the benefits that you confer on them without any dispute or mediation from anyone. Intellectual property on its intellectual product، and preventing others from exploiting it without obtaining the permission of its owner All of this is reflected positively on the progress of the industrial and commercial field، and this justifies the protection provided by the laws regulating intellectual property rights to its owner، whether at the national or international level، and with our recognition of the right of the owner of intellectual property rights to enjoy the exclusive use of his right، and
... Show MoreBreastfeeding (BF) serves as a complete nutritional source for the first six months of infant’s life. Breast milk contains all essential nutrients that necessary for the physiological growth and development of infants. The aim of this study was to compare the physiological growth of infants including weight, height and head circumference who were exclusively breastfed for 6 months and those who were given bottle-fed or mixed fed and to find a percentage of exclusive breastfeeding among mothers who contributed in this study in Sulaimani city. This study was carried out in Sulaimani city/ Kurdistan region of Iraq and the cases were enrolled between the first of October 2018 and first of October 2019. The infants’ weight, height and hea
... Show MoreThe image of television dominates the cognitive and artistic motivations. It is the formulation of ideas and visions along with its documentary ability. It is the main element in television work as it is a story that is narrated in pictures. Therefore, attention to image building is a major point of gravity in the work structure as a whole. On the image is the element carrying all aesthetic and expressive values of news and information directly to the hints that work to stimulate and stir the imagination of the recipient to evoke mental images added to the visual images to deepen the meanings.
All visual arts carry elements and components that follow in a particular pattern to give special meanings and specific connotations. However,
The research is conducted on target of investigating the role of growth strategy via diversification in value maximization of a firm in terms of controversies literatures had witnessed. Using a descriptive approach for analyzing and verifying the harmony of variables of research and their conceptualized logic , it could be reached to many conclusions agreed in their essence upon that the related diversification has the major role in value maximization of a firm and the wealth of its owners .
The theatre is one of the main pillars of the human aesthetic thinking as it contains logical explanations for the public human life aspects outside time and environment. When we find that the directive philosophical thinking moving away from the stylistic constants and the virtual laws in taboos that control the accomplishment in terms of the traditional shapes, the employment and the theatrical reception. Some directors moved in post-modernism concepts in a perceptive that liberates thought from its natural context in thinking into an innovative perceptive. The aesthetic images are the basic premise in the prohibition of the philosophical thinking interpretation in order to move the directive thinking and this movement depends on the v
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The current research aims to determine the relationship of the impact of the components of the financing structure, especially financing through debts, as well as the earnings per share in the value of the shares of companies listed in the Iraq Stock Exchange. The research sample and identifying the strength of the combined effect of the ratio of financing through debt and earnings per share in maximizing The market value of the firm and the real value, as well as the variation between these relationships according to model of the real value of the companies and the market value of the research sample companies. The research community is represented by the Iraq Stock Exchange, while a conditional deliberate sample
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