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Research Interests:
This work aims to study the ability of austempering DIN CK50 and DIN 62SiMnCr4 steels. Both steels were heated to austenitising temperature and then quenched in a molten metal bath (pure lead) at temperature below the nose of the TTT... more
This work aims to study the ability of austempering DIN CK50 and DIN 62SiMnCr4 steels. Both steels were heated to austenitising temperature and then quenched in a molten metal bath (pure lead) at temperature below the nose of the TTT curves for both steels. Results showed that austempering at 350oC and 400oC for 30 and 15 minutes are the best for above steels respectively, where strength was increased. It was also shown that increasing holding (soaking) time decreases both hardness and strength and increasing elongation percentage. Microstructure examination showed that the majority of microstructures obtained from austempering vary from bainite and pearlite and ferrite for carbon steel to a mixture of bainite, retained austenite and martensite for the alloy steel.
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ظهرت تكوينات اجتماعية مهمة في العصر العباسي أدّت دوراً بارزاً في الحياة العامة في المدن الإسلامية بشكل عام ، وبغداد عاصمة الخلافة العباسية بشكل خاص . وقد شهدت هذه الحقبة تطوراً واضحاً في الجانب الحرفي أدى في النهاية إلى بروز واضح لهذه... more
ظهرت تكوينات اجتماعية مهمة في العصر العباسي أدّت دوراً بارزاً في الحياة العامة في المدن الإسلامية بشكل عام ، وبغداد عاصمة الخلافة العباسية بشكل خاص . وقد شهدت هذه الحقبة تطوراً واضحاً في الجانب الحرفي أدى في النهاية إلى بروز واضح لهذه التكوينات في المدن الإسلامية ومن هذه التكوينات الأصناف والحرف . وأرتبط ظهورهم بتطور المدن الإسلامية وتطور النظرة إلى العمل والمهنة . قسم البحث على ثلاثة مباحث، شمل المبحث الأول مفهوم الأصناف والحرف وتركيبهم وتنظيماتهم، أما المبحث الثاني فكان علاقة الأصناف والحرف مع المؤسسة المدنية، وتناول المبحث الثالث علاقة الأصناف والحرف مع المؤسسة العسكرية. أما الخاتمة فكانت النتائج التي توصل إليها البحث.
ان تمسك سكان المدن المفتوحة من قبل المسلمين , بدينهم القديم عرضهم لدفع الجزية والتي تدل على الضريبة من اي نوع يدفعها غير المسلمين إلا انها اصبحت اخيراً تدل على ضريبة الرأس , ولقد كانت هذهِ الجزية من البساطة بحيث لم تكن تثقل كاهلهم ,... more
ان تمسك سكان المدن المفتوحة من قبل المسلمين , بدينهم القديم عرضهم لدفع الجزية والتي تدل على الضريبة من اي نوع يدفعها غير المسلمين إلا انها اصبحت اخيراً تدل على ضريبة الرأس , ولقد كانت هذهِ الجزية من البساطة بحيث لم تكن تثقل كاهلهم , وذلك اذا لاحظنا انها اعفتهم من الخدمة العسكرية الاجبارية التي كانت مفروضة على اخوانهم من الرعايا المسلمين , ثم ان الجزية لم تكن مفروضة على كل اهل الذمة , بل كان يدفعها فقط الذكور القادرين على حمل السلاح واعفي منها ذوو العاهات والضعفاء والمترهبون وغيرهم , وان الغرض من فرضها ليس من اجل ان تكون لوناً من الوان العقاب لأهل الذمة كما حاول بعض المستشرقون اشاعته, وانما من اجل توفير الحماية التي كفلتها لهم سيوف المسلمين, وان ما اشتمل عليه هذه الملخص من نقاط انما تمثل اراء تبناها المتشرف الانكليزي السير توماس ارنولد, وهو ما اتخذناه موضوعاً للبحث هذا الذي فيه كذلك ترجمة بسيطة لأهم مفاصل حياة هذا المتشرف العلمية والعملية .
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Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for... more
Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical...
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Our study aimed to compare between ultrasound elastography (UE) and fine needle aspiration cytology (FNAC) in prediction of malignancy in thyroid nodules based on histopathology results. A total of 60 patients with thyroid nodules, who... more
Our study aimed to compare between ultrasound elastography (UE) and fine needle aspiration cytology (FNAC) in prediction of malignancy in thyroid nodules based on histopathology results. A total of 60 patients with thyroid nodules, who had an indication of thyroidectomy, were involved in this study after approval was obtained. They were selected for ultrasound elastography (UE) and fine needle aspiration before surgery. Then followed by FNA, and further with histopathology after surgery. 19 cases in elastography examination which diagnosed as benign nodules and confirmed histologically were classified as score 1and 2. The sensitivity of the elastography was 87.5% and specificity 85.7% whereas FNA showed 87.5 %, and % 96.4 for sensitivity, specificity respectively. ROC analysis showed the area under the elastography curve was 0.88 (95% confidence interval, 0.712 to 1.02) while 0.92 (95% confidence interval, 0.779 to 1.06) for FNA curve. FNA is still more reliable than ultrasound elas...
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The present study deals with the wear behavior of Al-Re alloy/ RHA-Y2O3 hybrid composites. The Aluminum-Rare earth alloy (Al-Re) was used as a matrix to be reinforced with rice husk ash (RHA) and yttrium oxide (Y2O3). The Aluminum-Rare... more
The present study deals with the wear behavior of Al-Re alloy/ RHA-Y2O3 hybrid composites. The Aluminum-Rare earth alloy (Al-Re) was used as a matrix to be reinforced with rice husk ash (RHA) and yttrium oxide (Y2O3). The Aluminum-Rare earth matrix alloy (Al-Re alloy) was prepared by melting 4032Al alloy with a standard Mg-Re alloy (AE42 alloy contains cerium and lanthanum) .The desired Al-Re alloy/ RHA-Y2O3 hybrid composites were produced by using two-steps stir casting process by adding RHA: Y2O3 in weight ratios 4:0, 3:1, 2:2, 1:3 and 0:4 to Al-Re alloy such that the total reinforcement is 10wt% . Dry sliding wear, coefficient of friction, hardness, apparent density, percentage of porosity were examined. The prepared hybrid composites were characterized using optical micrograph , SEM and X-ray diffraction. The addition of rare earth element (cerium and lanthanum) increases the hardness and the density and lowers the wear rate by decreasing the porosity in the matrix, refinement o...
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Background: The improvement of high-resolution ultrasound equipment has provided the possibility of determination of the fetal gender during pregnancy. However, because of the way in which the genitalia develop, the accuracy of gender... more
Background: The improvement of high-resolution ultrasound equipment has provided the possibility of determination of the fetal gender during pregnancy. However, because of the way in which the genitalia develop, the accuracy of gender identification is different among gestational age. Objective: To assess the accuracy fetal gender determination during prenatal screening and to find in which week of the gestational age is more accurate. Methods: A questionnaire had been distributed to a group of sonographers working in king Abdulaziz University, Jeddah and Khobar hospitals .another questionnaire prepared for a group of women who delivered their babies in those hospitals. Data collected, analyzed by using Microsoft Excel software. Result: 13 (76%) of the responses indicated that fetal gender determination by ultrasound has a high precision in second trimester (13-27 weeks of gestational age), while the remaining 4(24%) found the gender can identified in the first trimester. Of the of ...
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A336.0 aluminum alloy used to fabricate hybrid composites using rice husk ash (RHA) and MgO particles as reinforcement. The influence of the particles on the wear behavior of A336.0 aluminum alloy as a matrix that reinforced with MgO and... more
A336.0 aluminum alloy used to fabricate hybrid composites using rice husk ash (RHA) and MgO particles as reinforcement. The influence of the particles on the wear behavior of A336.0 aluminum alloy as a matrix that reinforced with MgO and RHA was investigated. Firstly, the rice husk burned at 700°C and then heat treated at 1100°C for 2 hrs. The ash characterized by X-ray florescence and X-ray diffraction. Less than 53 and 125 micron are the particle sizes of MgO and RHA respectively. The hybrid composites manufactured using stir casting method in two steps. A336.0 aluminum alloy reinforced with 4:0, 3:1, 2:2, 1:3 and 0:4 of RHA: MgO with 10 wt% total reinforcement phase. Optical microscope and X-ray diffraction were used to characterize the prepared hybrid composites. Dry sliding wear, hardness, apparent density, percentage of porosity and coefficient of friction were examined. Results indicated that porosity, apparent density and hardness enhanced with increasing MgO, while increasi...
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The current article is an applied study that conducted on 480 Egyptian Millennials who randomly volunteered as participants. The main objective of the research is to test the effect of social media usage on the level of political... more
The current article is an applied study that conducted on 480 Egyptian Millennials who randomly volunteered as participants. The main objective of the research is to test the effect of social media usage on the level of political expression and consequently on online and offline participation. A self-administered questionnaire has been used to collect responses to be analyzed and the results show that there is no significance of relation between social media and political expression and participation for the sample units of the study. Also, findings confirmed the significant correlation between expression and participation in its two forms; online and offline.
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This paper was developed to investigate the different factors affecting the Brand Equity of Private Label Brands and Perceived Value in the Egyptian market. 578 random shoppers in 26 branches all over Egypt completed questionnaire about... more
This paper was developed to investigate the different factors affecting the Brand Equity of Private Label Brands and Perceived Value in the Egyptian market. 578 random shoppers in 26 branches all over Egypt completed questionnaire about their perception of different factors affecting Brand Equity. Brand Associations, Perceived Value and Brand Loyalty are considered the most important factors that affect the Brand Equity of Private Label Brands; However, Perceived Quality, Brand Image and Brand Awareness are considered to be the least effective factors. Demographics were found to be insignificant. Marketers should focus on the top three effective factors, which are Brand Associations, Perceived Value and Brand Loyalty in order to increase the Brand Equity of the Private Label Brands. The results will offer direction to marketers and decision makers, especially that Private Label Brands are increasing dramatically.
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Mobile phone Banking is the latest self-service banking innovation; which represents potential opportunities for both customers and banks. Though it emerged in the early 2000's, it is still in its infancy stage in Egypt. This study... more
Mobile phone Banking is the latest self-service banking innovation; which represents potential opportunities for both customers and banks. Though it emerged in the early 2000's, it is still in its infancy stage in Egypt. This study aimed to investigate the factors that affect customers' acceptance of mobile banking. The theoretical framework of this study is an extension of TAM and IDT. A sample of 461 bank customers participated in this study. The most significant factors which affected customer's adoption of mobile banking were; perceived compatibility, perceived usefulness, perceived ease of use, credibility, trust, risk, and cost, respectively. Moreover, it was found that ease of use influenced usefulness, while perceived trust affected risk perceptions. Marketers should emphasize on developing a positive customers' attitude towards M-banking, the ease of use of mobile banking which will enhance customer's perception of usefulness, and focus on communications...
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Organizations are realizing the importance of social media and social networking sites as a communication channel for their brands. Startups, which are new small ventures, face many challenges to prosper in today's fast-paced economy.... more
Organizations are realizing the importance of social media and social networking sites as a communication channel for their brands. Startups, which are new small ventures, face many challenges to prosper in today's fast-paced economy. This research focuses on the challenge of building brand advocacy against the start-ups' low brand awareness and limited financing capabilities. Brand advocacy is defined as the extent to which consumers recommend the brand to their community. It is mainly characterized by high brand loyalty and strong positive electronic word of mouth. This research aims to explore the drivers of brand advocacy on social media in case of startups. The results of the will serve as the input for the second phase which follows a quantitative approach in which a survey will be undertaken to determine first, the relationship between the variables validated in the first phase and brand advocacy mediated by brand loyalty and electronic word of mouth, and second, test...