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.
It is no secret for those concerned with language concerns that the issue of figurative feminization is one of the issues that does not follow a grammatical rule governed by the fact that the subject of knowledge of this is due to hearing as indicated by linguistic references and lexicons.This research opts to find out the origin of the feminization of the word sun in the Arabic language and in light of what some language specialists have argued that the origin of figurative feminization was due to non-linguistic motives related to religious and metaphysical beliefs, and that it was memory preserved in light of the linguistic heritage.The research concluded that the feminization of the sun goes back to what settled in their minds, which
... Show MoreThe researcher seeks to know the extent of applying the concept of design by Iraqi electronic press sites to provide media product with the acceptance of their browsers and ensure their repeated visits to such sites in the framework of the guiding rules for laser browsing. The researcher uses analytical study on a sample of six Iraqi electronic newspaper sites to identify the general features of their design and the methods of distribution of the structural elements of the pages. The researcher also conducts a field study on a sample of the surfers of electronic newspaper sites to see the extent of their evaluation to their design and the degree of their satisfaction.
The analysis of the root cause techniques is a reasonable option to be made to assess the root causes of the funding of construction projects. There are a variety of issues related to financing in construction industries in Iraq. The root,cause analysis is the impact of security and social conditions on financial funding. Variety tools of root cause analysis have originated from literature, as common methods for the detection of root causes. The purpose of this study was to identify and diagnose causes that lead to obstruction of financial funding in the construction projects in the republic of Iraq from the contractors' point of view and their interaction with a number of variables. The study diagnosed nine causes of fi
... Show MoreIn this paper, we used maximum likelihood method and the Bayesian method to estimate the shape parameter (θ), and reliability function (R(t)) of the Kumaraswamy distribution with two parameters l , θ (under assuming the exponential distribution, Chi-squared distribution and Erlang-2 type distribution as prior distributions), in addition to that we used method of moments for estimating the parameters of the prior distributions. Bayes
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The current study aims to identify:The meta-motivation and Uniqueness seeking of the study sample. The correlated relationship among them. The present study sample consists of (400) students from the colleges of engineering, University of Baghdad, and the University of Technology in the academic year (2019-2020), and the researcher has adopted the Chen Scale (1995)to measure the meta-motivation after its translation into Arabic by(Al-Samawi,2011).The scale includes six dimensions. The researcher has also adopted the Snyder&Fromkin scale (1980) to measure the uniqueness seeking after translating and adapting it into the Arabic environment. The scale consists of three dimensions. The results show that students of the Facult
... Show MoreThe nature of the political system of any country in the international system must have an impact on the policy of the State, whether in the interior or exterior, both regional and international, Turkey is one of the most important countries in the Middle East, which have a place and effectiveness on the surrounding environment, hence the importance of research lies in its political system and the transfer of power in it and its transformation from the form of the parliamentary system to the presidential system of the repercussions of the task and mutual effects between Turkey and the countries of the surrounding region in terms of the extent of achieving political stability in the Turkish interior or not and how this can be refl
... Show MoreTo get access into the orbital floor 3 paths are commonly used which are transconjunctival, subciliary and subtarsal approaches. Each one of these approaches has its advantages and disadvantages. The study assessed the outcomes of the transconjunctival retroseptal approach, which reflects our experience in this type of surgery. Along 8 years, 26 patients received in the emergency room diagnosed with pure isolated orbital floor fractures, all of them admitted to the maxillofacial surgery department and approached by transconjunctival incision without lateral canthotomy. Three types of complications occurred: laceration of the lower eyelid, injury to the lacrimal system and entropion. All of these complications were managed accordingly with n
... Show MoreUrban planning task and the control of constructional planning and urban management for cities considers the main tasks that the government takes care off. The paper discusses the concept of power from historical view of ancient Islamic cities to discover the strategies of urban management that the Islamic city adopt and to employ it in contemporary cities ,the more problems that modern cities suffer from which appears through poorness of urban context ,belongs to the loss of balance exists between the different faces of power that takes the tasks of urban management .therefore enhancement of urban environment is being through re-back that balance in administrative structures that make the cities go ahead . So the attention has b
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