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.
First: People’s need for advocacy:
Calling for a legal necessity for all people, regardless of their races, colours, tongues, and culture, to explain the truth, spread fear, bring benefits, ward off evil, regulate a person’s relationship with his Lord, and his relationship with creatures, so that he knows his money and what he owes.
All of creation is in dire need of the call to God’s religion with insight due to their inability to reach out to goodness, righteousness, guidance, and success on their own. Man is limited in thinking in this universe, limited in his resolve, unable to know what will improve his affairs in the two worlds. His need for religion is one of the necessities of his life, and one of the comple
... Show MoreConstruction 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 MoreDespite efforts to contain and manage the SARS-CoV-2 outbreak which was declared a public health emergency of international concern in January 2020 by the World Health Organization (WHO), the COVID-19 pandemic still remains a major global challenge. Patients who display the classical symptoms of the infection are easily identified, tested, isolated and monitored. However, many cases of infected asymptomatic patients have been documented. These patients are not easily identified even though many evidences suggest that they can spread the virus to others. How and why these COVID-19 asymptomatic presentations occur remain unclear. The many theories and views are conjectural, and supporting evidences are still needed. In this review, we
... Show MoreLet G be a graph with p vertices and q edges and be an injective function, where k is a positive integer. If the induced edge labeling defined by for each is a bijection, then the labeling f is called an odd Fibonacci edge irregular labeling of G. A graph which admits an odd Fibonacci edge irregular labeling is called an odd Fibonacci edge irregular graph. The odd Fibonacci edge irregularity strength ofes(G) is the minimum k for which G admits an odd Fibonacci edge irregular labeling. In this paper, the odd Fibonacci edge irregularity strength for some subdivision graphs and graphs obtained from vertex identification is determined.
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
... Show MoreThe 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 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
... Show MorePraise be to Allah , and peace and blessings of God sent mercy to the worlds Muhammad
Amin and his family and his friends and followers to the Day of Judgement .
Savants Jews worked to distort the Torah calamity on the Prophet Moses ( peace be upon
him ) to achieve their goals and objectives , which are decorating sin to their followers , and
spreading corruption on earth, through the charge prophets Bmvassad , morality, as the
example and the example that emulate the human in the book of the Lord of the worlds and
their Prophet Lot, described the weak, and cheese, and lack of modesty, and disobedience ,
drinking alcohol , and his failure to raise his two daughters , Jews are corrupt in the ground .
Koran , which
The 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,