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.
B Saleem, H Alwan, L Khalid, Journal of Engineering, 2011 - Cited by 2
Background: A review of articles of method in treating compound phalangeal fractures by using mini-external fixator, elaborating the anatomy, mechanics, modalities of treatment, and complications of these types of fractures. Also, it compares between different studies regarding the functional results and final outcome. External fixation of phalangeal fractures is a good method for osteo synthesis in certain situations. The simplicity of the surgical procedure and the minimal disruption of the normal bone architecture also make it appealing. Objectives: Evaluating the functional results of the use of mini-external fixator for the treatment of compound fractures of phalangeal bones of the hand. Method: Our study consists of 15 patients, 12 we
... Show MoreNerium oleander known as oleander has belonged to the poisonous plants its habitat in a tropical andsubtropical region. The chemical analysis with GC-Mass of the alcoholic extract of oleander leaves revealedthat this plant has many chemical compounds more than 80 compounds and high-peaks about 29 compoundswhich are represented by alkaloids, phenol, terpenes, and fatty acid. HPLC analysis showed many essentialoils that have many biological effects.To evaluate the antibacterial activity of the alcoholic extract of N. oleander against locally isolatedPseudomonas aeroginosa the broth micro-dilution method was adapted to different concentrations werestarted from 3.9 to1000 mg/ml. The results revealed that the alcoholic extract has antiba
... Show MoreThe Moisture damage is considered as one of the main challenge for the experts in the field of asphalt pavement design. The aims of the present study is to modify moisture resistance of the asphalt concrete by utilizing ceramic fibers as a type of reinforcement incorporated with hydrated lime. For this purpose, a penetration grade of the asphalt cement (40-50) was utilized as a binder with an aggregate of the maximum nominal size of 12.5mm and mineral filler limestone dust. A series of specimens has been fabricated by utilizing 0.50, 1.0, 1.5, and 2.0 percentages of ceramic fibers. For each of these contents, another subsequent group of specimens with hydrated lime with 0.0, 1.0, 1.5, and 2.0 percentages were moulded. For the additi
... Show MoreA kindergarten teacher is one of the most important elements in the educational process, since she is totally relied upon in kindergartens. Therefore, she could have basic and healthy characteristics to improve the educational process by directing the child towards a perfect growing upEducating and raising up a child should be an organized process that makes desirable changes in the child’s behavior in order to improve different sides of his personality, such as his appearance side, his mental side, and his social side.
This research aims at:
1- Measuring the scientific brilliance in kindergarten teachers.
2- Investigating the statistical significant differences of the scientific brilliance among kindergarten teachers in accor
The aim of this study is to assess nurse's knowledge and role in the management of thalassemic patients in the Sulaimania Thalassemia Centre. Methodology: This study utilized a qualitative approach to explore nurses’ knowledge about thalassemia through semi structured group interviews. Questionnaire was synthesized through a comprehensive review of literature. Results: The results show that nurses in Kurdistan region of Iraq have a limited role in terms of decision making and there is lack of nursing documentation other than that of recording abnormal events, and a lack of knowledge about and engageme
The current study aims at identifying:
1-The intellectual stress of counselors according to gender variable (male, female ).
2-The five major factors of the Counselor's Personality.
3- The relationship between intellectual stress and the five major factors of the councilors' personality and according to gender variable (male, female ).
4-The significant differences in the relationship between intellectual stress and the five major factors of the councilors' personality and according to gender variable (male, female ).
The sample of the study includes (260) counselors (130 male
... Show MoreAfter looking at the books of the first two grammarians, may God have mercy on them and reward them for what they have provided us with the rules of service to the Book of God and service to Arabic, we must highlight some of the things that the grammarians wanted to clarify, which did not come out of what they proved, but we are working on the statement of the issuance of the passport Provisions from the syntactic industry, and whether it is intended to prove a rule is not very added to the statement of speech, and we know that language, any language was the function of understanding; therefore they said: (speech is a useful word that indicates the benefit improves silence on them), and this concept between Grammatical controls and conte
... Show MoreHuman resources have been regarded as the most important asset for any organization because of its essential part in achieving the sustainable competitive advantage and survival. Managing human resources is very challenging and requires an effective bundle of practices that contribute to attaining the organizational goals. This study tries to confirm the importance of HRM practices in small businesses which came to play a vital role in the economies of the world, through clarifying the influence of HRM practices on the organizational performance, using a mediating variable (employees’ outcomes). Also the study attempts to highlight the key role of governmental support from view point of small businesses, through verifying the significant
... Show MoreThe aim of this research is to solve a real problem in the Department of Economy and Investment in the Martyrs establishment, which is the selection of the optimal project through specific criteria by experts in the same department using a combined mathematical model for the two methods of analytic hierarchy process and goal programming, where a mathematical model for goal programming was built that takes into consideration the priorities of the goal criteria by the decision-maker to reach the best solution that meets all the objectives, whose importance was determined by the hierarchical analysis process. The most important result of this research is the selection of the second pro
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