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.
مقدمة
تدور الدراسة في علم الاقتصاد المنزلي حول احتیاجات الانسان الضروریة لاستمرار الحیاة ومواقف في محیط
الاسرة وتفاعل مع ظروف البیئة المحیطة بھ .والتي تكون دائمة التغییر لذلك یمكن تعریف علوم وفنون الاقتصاد
المنزلي وفنونھ انھا عبارة عن مجموعة منظمة من المعارف والعلوم تتركز في محور الاسرة والمنزل حیث ینمو
ویتطور الانسان بالعلاقات الانسانیة والنواحي الاقتصادیة والاجتماعیة من جھة والنواحي العلمیة وا
The current research aims to identify the perceptual speed of the university students as well as to identify the differences in the level of perceptual speed for the university students according to the variables of (male, female) specialization (scientific, human) university (Baghdad, Mustansiriya). Additionally, the research aims to identify the prevalence of emotional pattern and to identify the relationship between perceptual speed and the emotional patterns among university students. The researcher designed a questionnaire to measure the Emotional Patterns based on Jerome Freedman perspective. As for perceptual speed, the researcher adopted French, Extrom and Price scale (1963), which was tran
... Show MoreBeta-carotene pigment was extracted from 6 strains collected from different sources related to some species of the genus Rhodotorula sp. The maximum productivity was in the strain Rhodotorula mucilaginosa BA61 with amount 10.25 gm/l. The minimum productivity was from the strain R. minuta BA78 with amount 5.39 gm/l. The effects of the chemical mutagen (MNNG) and the physical mutagen (UVC) on the viability of the strains was studied. The results revealed that the chemical mutagen (MNNG) with the concentration 0.2 mg/ml has the clear effect on the viability of the strains , which killing percentage reached to 65.91% in the strain R. minuta BA78. Results of the study of mutagenesis with UVC showed that increase in killing percentage fo
... Show MoreLeishmaniasis is a group of parasitic diseases caused by Leishmania spp., an endemic infectious agent in developing countries, including Iraq. Diagnosis of cutaneous lesion by stained smears, serology or histopathology are inaccurate and unable to detect the species of Leishmania. Here, two molecular typing methods were examined to identify the promastigotes of suspected cutaneous leishmaniasis samples, on a species level. The first was species-specific B6-PCR and the second was ITS1-PCR followed by restriction fragment length polymorphism (RFLP) using restriction enzyme HaeIII. DNA was extracted from in vitro promastigote culture followed by amplification of kDNA by B6 or amplification and digestion of LITSR/L
... Show MoreThe present work aimed to make a comparative investigation between three different ionospheric models: IRI-2020, ASAPS and VOACAP. The purpose of the comparative study is to investigate the compatibility of predicting the Maximum Usable Frequency parameter (MUF) over mid-latitude region during the severe geomagnetic storm on 17 March 2015. Three stations distributed in the mid-latitudes were selected for study; these are (Athens (23.50o E, 38.00o N), Jeju (124.53o E, 33.6o N) and Pt. Arguello (239.50o W, 34.80o N). The daily MUF outcomes were calculated using the tested models for the three adopted sites, for a span of five-day (the day of the event and two days preceding and following the event day). The calculated datasets were co
... Show MoreThis study included isolation of some active materials from Curcuma longa such as tannins, saponins and volatile oils with percentage of 59%, 31%, and 9% respectively. Also the study included the determination of minerals in Curcuma longa such as " Na, Ca and K" using Flame photometer. The concentrations of these minerals were (14 ppm),(10 ppm) and )76 ppm) respectively. The anti-bacterial activity study was performed for the active materials isolated from Curcuma longa against two genus of pathogenic bacteria, Escherichia Coli and Staphylococcus aurous by using agar-well diffusion method. It appeared from this study that all of the extraction have inhibitory effect on bacteria was used. The inhibition zone diameter varies with
... Show MoreIn recent years, there has been expanding development in the vehicular part and the number of vehicles moving on the roads in all the sections of the country. Arabic vehicle number plate identification based on image processing is a dynamic area of this work; this technique is used for security purposes such as tracking of stolen cars and access control to restricted areas. The License Plate Recognition System (LPRS) exploits a digital camera to capture vehicle plate numbers is used as input to the proposed recognition system. Basically, the proposed system consists of three phases, vehicle license plate localization, character segmentation, and character recognition, the
... Show MoreThis paper has investigated experimentally the dynamic buckling behavior of AISI 303 stainless steel Aluminized and as received long columns. These columns, hot-dip aluminized and as received, are tested under dynamic buckling, 22 specimens, without aluminizing (type 1), and 50 specimens, with hot-dip aluminizing at different aluminizing conditions of dipping temperature and dipping time (type 2), are tested under dynamic compression loading and under dynamic combined loading (compression and bending) by using a rotating buckling test machine. The experimental results are compared with Perry Robertson interaction formula that used for long columns. Greenhill formula is used to get a mathematical model that descripts the buckling behavior
... Show MoreThe characters of facades' form of the Iraqi building after 2003 have been changed, it has been described by many names. The problem of the research is that what are the features of the characters of the form in the façades of the buildings in Baghdad city after 2003? Are the façade of the individual houses or the commercial buildings is the heaviest in the visual weight? The research aims to answer those questions by choosing the vernacular architecture as a measurement tool. It is the informal image of the architecture, which is built by people informally and spontaneously, without official control and legislation to be organized. This is smellier to what has happened in Baghdad, after 2003 according to previous stud
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