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.
Summary
This research is included in the study of one of the most important rules of jurisprudence, which is (necessity descends the status of necessity, controls and applications) branching from the major rule (hardship brings facilitation) and since the jurisprudential rule is defined as knowledge of a total or majority rule that applies to all its parts. He has to know all the branches that fall under him, which leads to understanding Sharia, controlling jurisprudential issues and linking them to its rules, so that no contradiction occurs, and he has the jurisprudential faculty that he promotes in consideration and diligence. And what is meant by need: is what is lacking in terms of expansion and raising the distress that often lea
Results of charge, neutron and matter densities and related form factors for one- proton halo nucleus 8B are presented using a two- frequency shell model approach. We choose a model space for the core of 7Be different from that of the extra one valence proton. One configuration is assumed for the outer proton to be in 1p1/2 - shell. The results of the matter density distributions are compared with those fitted to the experimental data. The calculated proton and matter density distributions of this exotic nucleus exhibit a long tail behavior, which is considered as a distinctive feature of halo nuclei. Elastic electron scattering form factors of this exotic nucleus are also studied. The effects of
... Show MoreAn experiment was carried out evaluate the performance of RAU combined equipment under three levels of practical speed, (V1) 4.06 km. h-1, (V2) 4.43 km. hr-1 and (V3) 5.76 km. hr-1, and three levels of depth with 10,20and 30 cm. It is denoted by D1, D2, D3 respectively. A split plot design was used within the RCBD design with three replications. The experiment results showed that the first practical speed 4.06 km.hr-1 achieved the lowest slippage percentage from 9.61%, lowest traction power 14.65hp, lowest soil penetration resistance to1.34 kg.cm-2, and the highest total operating
Which was entitled : Aesthetic and dramatic dimensions of silence in the feature film , and the researcher clearly define after removing the confusion existing in some authorized sources , as for the concept of silence , adopted in this research is : the death of the audio stream , Hence the researcher shed a light on the aesthetic and the dramatic role of silence in the feature film , through the handing of the silent scenes ( absolute silence ) in the film research divided this research into four chapters . This first Chapter includes : methodological framework , which represents the research problem , which came with the following question : what is the mechanism of productive silence to the
... Show MoreTaliban has returned to the forefront since regaining control of Afghanistan in mid-August 2021, prompting the international community and researchers to speculate whether it has adopted a different political vision and ideology from its previous rule (1996-2001). The previous rule presented a distorted version of governance that lacked clear political and ideological foundations, characterized by impulsive and chaotic decisions, and the absence of a comprehensive theoretical and intellectual framework for governance.
Once again, Taliban returned to power on August 15, 2021, and took control of the country. This raised many questions about Taliban's return, the extent of its flexibility and adaptability that allowed the movement t
... Show MoreThe Lamiaceae L. family grows and widely distributed in Iraq. The study aimed to enumerate the species that has been preserved in several botanical herbariums: National Herbarium of Iraq- Ministry of Agriculture (BAG), University of Baghdad Herbarium (BUH), Iraq Natural History Research Center& Museum- University of Baghdad Herbarium (BUNH), College of Agricultural Engineering- University of Baghdad Herbarium (BUG), College of Agricultural Engineering Sciences- Duhok Province University Herbarium (DPUH) and College of Science - Salahddin University Herbarium (SUH). This family has not yet been registered in the Flora of Iraq. After examining more than 1000 herbarium specimens, the study found 139 species belonging to 33 genera h
... Show MoreIt’s an attempt to identify the cultural activities of the Ministry of Culture, Tourism and Antiquities, which are provided by the Ministry of Culture, Tourism and Antiquities and the departments affiliated with the Ministry of Culture only, not tourism and antiquities. The most important results areIs that the Ministry of Culture, Tourism and Antiquities has many cultural activities such as (festivals, exhibitions, conferences, fashion shows, concerts, musical evenings, theatrical and cinematic performances) in addition to literary series and cultural magazines, which are directed to the public in general, whether it is elite or not, and this shows the extent The importance of cultural activities published by the Ministry of Culture, Tou
... Show Moreشهد العالم مع بداية القرن الحادي والعشرين تدشين مرحلة جديدة من التطور شملت مختلف الميادين لاسيما في مجال التطورات العلمية والثورة المعلوماتية.. كما إن مسار الديمقراطية في بعض دول العالم يصبح سالكا خاصة في تركيا, فمنذ اواسط الثمانينيات من القرن الماضي فتح المجال السياسي امام قوى كانت مسحوقة ومهمشة, ويكاد ان لا يكون لها وجود في الحياة السياسية للنزول الى ساحة العمل السياسي اسوة ببقية القوى ا
... Show MoreAdaptive responses in larval behavior may be of two kinds: Taxis: This involves a change in direction relative to source of a stimulus. Kinesis: Kinesis has no directional component, but involves change in the rate of performance in response to a stimulus. Drosophila larvae exhibited flexible behavioral responses associated with food acquisition and selection for different environmental conditions. In this investigation, we are concerned explosively with kinetic responses to food viability. Third instar larvae were subjected to test for thirty minutes in each of the following conditions i) in distilled water, ii) in Ringer's solution, iii) in glucose solution and on live yeast suspension. In each case the larva was in a thin layer of solu
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