SUST Journal Systems (Sudan Univ. of Science and Technology)
Not a member yet
189 research outputs found
Sort by
Aerodynamic Coefficients Investigation of GRAD Rocket Using Computational Fluid Dynamics
Get PDFThe article provides an aerodynamic characteristics investigation of GRAD Rocket using the computational fluid dynamic method. Computational analysis has been performed to predict the Aerodynamic characteristics of the GRAD rocket. A commercial software ANSYS FLUENT is used to simulate the unsteady aerodynamic characteristics of the missile while the Missile DATCOM software is used to confirm and validate the results. The simulations have been conducted out for a range of Mach number 0.4 to 3 versus angle of attack from 0° to 9°, through the sideslip angle 0° to 9°. The results represent that the Drag Coefficient is highly sensitive to the angle of attack and velocity region. The total drag of the missile is mainly generated from the missile's body, where they wrap around fins contribute only 18.45 percent of a total drag coefficient. In contrast, the lift coefficient increases with an increased angle of attack, but it decreases with changes of the region from subsonic to supersonic. The flow visualization of the static and dynamic pressure contours is illustrated. The Shock wave is captured at the nose and fins entrance. To verify the results, the simulations were carried out for two missile models. The first model represents the cylindrical body of the fin-less missiles, and the second one represents the rocket body with fins
Analysis of Irrigation Water Requirements in Gezira Scheme Using Geographic Information Systems: Case Study Block Number 26 (Dolga)
Get PDFWater scarcity has a direct impact on food security and a real threat to food production for millions of the population. To avoid the unwise and random consumption of available water resources, it is high time for using efficient system and appropriate policies for management of irrigated farms to control water overuse, starting by the analysis of the existing reality. Block number 26 (Dolga) in Gezira scheme had been chosen as a study area. The total area of the study area is about 24616 Feddans. The study aims to apply GIS in the data editing, manipulation, storage, processing, and presentation for the analysis of irrigation water requirements. GIS had been chosen for its capabilities of data capturing, data processing and efficient spatial analysis. Layers of geo-referenced spatial database including crops’ maps, irrigation canals network and its command area, each crop water requirements, irrigation water requirement, rainfall data, area cultivated for each crop and contour map of the study area had been created and used for the spatial analysis in ArcGIS software. Five course rotations are applied for the crops of cotton, wheat, sorghum, and groundnut. Each crop covers 20% of the total area and the remaining 20% are fallow and layer for each crop had been created. Crops’ water requirements had been calculated applying Penman-Monteith method and saved in the attributes Table of crops layer. It had been found that the seasonal crop water requirements per Feddan for each crop is 3,871.56 m3, 2,983.26 m3, 1,847.16 m3 and 2,007.6 m3 respectively, calculated using Penman-Monteith method. The total crops water requirements are 50,254,962.66m3(absorbed by plants), water allotment of the study area according to the ratio of the area is 67, 195,230.327 m3, irrigation water requirement is 64,537,716.5 m3 (including the water losses), where the actual water supply is 63,817,600 m3 which had been calculated applying ArcGIS tools and saved in the attribute Table of the crops and rotation layer. The study had concluded that cotton consumes the largest amount of water supply, rainfall water is in irrigation has the used only in the complementary irrigation of sorghum crop and the implementation of GIS capabilities enables efficient analysis and scheduling of irrigation water
Design of a Noninvasive Magnetic Hyperthermia System for Breast Tumors Using Fe3O4 Nanoparticles
Get PDFBreast cancer is the second leading cause of death among women in the 40 – 55 age groups. There are many methods to treat breast cancer such as chemotherapy and radiation but they have many side effects such as hair loss and weakness. Magnetic hyperthermia is a modality that gives new hope for cancer treatment with minimum side effects. This technique relies on raising the temperature of the tumor to 41- 45°C by the alternating magnetic field generated from magnetic coil. This study aims to design suitable magnetic hyperthermia system consisted of breast models with tumors and coil to be used as source of alternating magnetic. Firstly, the magnetic coil was designed and tested, and then six 3D breast models were created. These models differ in the number of layers and the position of tumor. A Fe3O4 magnetic nanoparticles (MNPs) were added to each tumor. After that, the magnetic coil was tested with on the models and temperature elevation and distribution was calculated. The tumor near the surface reached a temperature of 44.2 ºC, while the deep tumor had a temperature of 42.5 ºC while the surrounding tissues remain at safe temperature ranges. The obtained results showed capability of the designed coil to raise the temperature of breast tumor to the therapeutic range
Dyeing Properties of Cotton Fabrics using Extracted Dyes from Ethiopian and Congolese Coffee
Get PDFA natural dye on textiles has gain significant importance for the reason that it was eco-friendly non-toxic, and increased environmental cognizance in order to avoid some dangerous synthetic dyes. In this study, the natural coloring substances such as Ethiopian and Congolese coffee (Coffee Arabica L) were useful to cotton fabrics, dyeing to both functionalize in addition to color the fabrics. The dyeing solution was prepared by extracting coffee grounds collected from Wad Medani Market-Sudan, they were extracted in hot water at 90 °C (raw coffee, medium-roasted and dark-roasted coffee). Also, the caffeine is separated and dyed with the coffee residues, the result was similar to the samples that were dyed with coffee. The coffee extract was used to Cotton fabrics using an infrared (IR) dyeing machine by conventional method at pH 8 for 90 min. The dyeing and surface properties of Cotton fabrics were investigated by Spectrophotometry and were characterized by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) to understand the performance of these natural dyes, respectively. The colors of the dyed Cotton fabrics obtained were found to be significantly light green for raw coffee, brown in appearance for medium-roasted and dark-roasted coffee, and their color fastness to washing and rubbing of dyed fabric with natural colorant extracts were compared. The results of fastness were found to be in the range of good to excellent. The dyeing properties of the color was found to be significantly reliable on the concentration of extracts and the degree of roasting of coffee
Evaluation of the Optimum Pre-Tensioning Forces for Cable Stayed Bridges
Get PDFThe Cable-stayed Bridge is one of the most modern bridges. The structural system of this type of bridge is effectively composed of cables, main girders and towers. Because of their complex structural system, Cable-stayed bridges are highly indeterminate structures that require a high degree of technology for analysis and design. Hence, they demand sophisticated structural techniques for analysis and design when compared with other types of conventional bridges. In such bridges the cables, being flexible supports, require pre-tensioning. These pre-tension forces are important factors in the design and construction process. Thus, the response of the bridge is highly non-linear and an optimization procedure is required to evaluate the pre-tensioning forces. In this study, the unknown load factor optimization method is the method used to determine the cable forces. The procedure is based on using finite element analysis programs. The cable tension of a cable stayed bridge is evaluated under the effect of Dead load (Self weight, additional loads), Initial pre- tension force in the cable, and live load (moving load) according to AASHTO LRFD 2010 and using MIDAS Civil computer program. TUTI BAHARI cable stayed bridge of semi-fan type arrangement is analyzed for static load as a case study. The unknown load factor optimization method is used to determine the cable pre–tension forces to achieve a perfectly safe and stable bridge. The maximum cable forces (6670 kN), as well as the stresses (372 N/mm2) and displacements at the top of tower (0.033308m), are found to be within the allowable limits. The results obtained illustrate that the unknown load factor optimization method leads to optimal structural performance for the cable stayed bridge. Hence it might be a useful tool for the analysis and design of such bridges
The effect of using recycled aggregates on reinforced concrete columns exposed to an axial compressive force
No full textAt present, the need for reusing destroyed concrete products and construction wastes WHICH resulted from demolitions or wars and natural disasters has emerged because of the increase in storing cost of these wastes and also the depletion of natural building materials over time, coarse aggregate (gravel) particularly. In this research, an experimental study was conducted on /14/ reinforced concrete columns exposed to a compressive axial force, column dimensions are (250 x 250 x 1000) mm, the parameters in this research are the reinforcement ratios (1%, 1.62%) and the replacing ratios of natural coarse aggregate NA by recycled concrete coarse aggregate RA as following (0%, 10%, 20%, 30%, 40%, 50%, 60%), The values of the maximum axial load on compression for columns were measured experimentally and compared with the mathematical values according to some international codes and the Syrian Arab Code. Also, The effect of changing replacing ratios of recycled aggregate was tested on the Characteristics of concrete mixtures (Compressive strength, Splitting Strength, Tensile Strength in bending), The results showed that the water absorption ratio of recycled aggregate is higher than natural aggregate, which requires adding extra amounts of water to concrete mixtures to conserve their workability and this leads to a reduction in the resulted concrete compressive strengths, and this study shows that concrete compressive strength decreasing value reached almost around 19.8% at age 28 days for replacing ratio 60% and this value can be acceptable to use these mixtures in reinforcement concrete according to Syria Arab Code, Also the concrete compressive strength increased by 9.32% at the replacing ratio 10%, the maximum axial load on compression decreased by 6% at replacing ratios smaller or equal to 40% while the decreasing reached about 15.7% for the replacing ratio 60%
Classification of customer call details records using Support Vector Machine (SVMs) and Decision Tree (DTs)
Get PDFOn a daily basis, telecom businesses create a massive amount of data. Decision-makers underlined that acquiring new customers is more difficult than maintaining current ones. Further, existing churn customers' data may be used to identify churn consumers as well as their behavior patterns. This study provides a churn prediction model for the telecom industry that employs SVMs and DTs to detect churn customers. The suggested model uses classification techniques to churn customers' data, with the Support Vector Machine (SVMs) method performing well 98.36 % properly categorized instances) and the Decision Tree (DTs) approach performing poorly 33.04 % and the decision tree algorithm deliver outstanding results
Experimental Investigation on Mechanical Properties of Hybrid Steel and Polyvinyl Alcohol Fiber Reinforced Concrete
No full textThe mechanical properties of hybrid fiber-reinforced composite concrete (HyFRCC) comprising varying amounts of steel fiber (SF) and Polyvinyl Alcohol fiber (PVA) are discussed in this study. The mechanical properties are studied in this study such as Concrete compressive cube strength and flexural strength. SF is known to improve flexural and tensile strengths, as well as prevent or minimize macro cracking patterns. Meanwhile, PVA increases tensile strain capacity and compressive strength, as well as delaying micro-cracks. Also, PVA increases tensile strain capacity and compressive strength, as well as delaying micro-cracks. This study used two hooked-end distorted varieties of SF fiber (65/35 for 3D and (65/60 for 5D) as well as PVA fiber with a 12 mm length. Also, grade C30 concrete strength is maintained. SF-PVA fiber percentages were varied between 0.0 percent, 0.50 percent, and 1.00 percent. According to the test results, the percentage proportion of SF (65/60 for 5D) fiber with 1.0 percent offered the maximum values of flexural strength, tensile strength, and flexural toughness. The 0.5 percent percentage of SF-PVA fibers helps to improve compressive strength when compared to ordinary concrete. Furthermore, the test findings revealed that the steel fibers' ability to regulate the crack spread of the specimens was demonstrated by the shift in failure mode from brittle to ductile
The Philosophy of Mosques Design Criteria Focusing on Columns, Mougarnasat, Shourofat and Karaneish
No full textلكل مبنى شكل وشخصية معينة تميزه عن رصفاءه حسب وظيفة هذا المبنى واستعمالاته وشخصيته المعمارية، وعناصره ومفرداته المكملة له. وقد تفردت شخصية عمارة المساجد في العالم بدءاً بالوظيفة الأساسية لهذه المساجد وهي الصلاة بحركاتها "قياماً وقعوداً" ثم بشكلها وكتلتها الظاهرة وعناصرها ومفرداتها، التي تتمثل في مساقطها الأفقية للفراغات الداخلية "صالة الصلاة" واشكاله المتعددة ثم مساحاتها المكشوفة "صحن المسجد" والمساحات الخضراء "الباحات" وبقية الكتل والفراغات المختلفة الأشكال والأروقة وكذا القباب والمآذن والمداخل لبيت الصلاة وللأسوار الخارجية وهذه العناصر تعتبر عناصر أساسية بالمساجد والعناصر الفرعية المكملة لها تتمثل في الحوائط والأقواس والسقوفات والفتحات من نوافذ وأبواب وما بداخل المسجد من عناصر وظيفية كالمنابر والمحاريب (الأعمدة، الحلبات، الزخارف، المقرنصات، الكرانيش والشرفات موضوع الدراسة) وكذا خدمات المسجد كالحمامات والمياضي، كل هذه العناصر هي مكونات شخصية المسجد داخلياً وخارجياً.
كل هذه المفردات والعناصر وسواء أن كانت قديمة أو حديثة اقتبست من حضارات وتأثرت زماناً ومكاناً بثقافة المجتمع والبيئة الطبيعية المحيطة واختلاف تقنيات ومواد البناء لذلك نجد عمارة المساجد في الطرز مختلفة عن بعضها البعض مثلاً كالطراز السلجوقي والعثماني والفارسي والعباسي والأموي والمغربي والأسباني والعربي الإسلامي ... الخ كل له شكله وتفاصيله المميزة، وبذا كونت شخصية المسجد المميزة وسط التخطيط العمراني التي لا تشبهها شخصية عمرانية أخرى، فتلك هي المعايير، ولكن شابت هذه المعايير في بعض البلدان المسلمة تغيرات وعدم التزام بها مما نتج عنه اختلاف في شخصية المساجد فقد جردت من بعض أو كثير من العناصر والمفردات، الدراسة تهدف إلى الالتزام من المصممين والمنفذين بالتدقيق على المحافظة على هذا النمط المعماري الفريد حتى نحافظ على هذا الطابع المعماري المسجدي المتفرد، ونعمل على التأصيل لتلكم العمارة المتخصصة بمنهجية تستهدف دراسة كل مكونات وعناصر هذا المبنى ودراسة وتحليل اشكالها حتى الوصول لأهم النتائج لها والتي بدورها ستحافظ على شكل شخصية المسجد وصولاً للخلاصات التي من اجلها تمت الدراسة بالبقاء على شكله وعناصره ومفرداته ثم التوصية بأن يبقى على هذه البنود والمحافظة عليها
دراسة سلوك الجوائز البيتونية على القص باستخدام بيتون عادي وبيتون ذاتي الاكتناز تجريبياً وحسابياً
No full textتعتبر الخرسانة ذاتية الاكتناز (SCC) نتاج التقدم في مجال إضافات الخرسانة حيث تعتبر إضافات معدلات اللزوجة وإضافات تقليل ماء الخلط (الملدنات الفائقة) هما العنصرين الأساسيين اللازمين لإنتاج هذه الخرسانة. تم في هذا البحث إجراء دراسة تجريبية على خمسة جوائز خرسانية ذاتية الاكتناز (SCC) وخمسة جوائز خرسانية عادية (NC) معرضة لحمولة انعطاف أربع نقاط. أبعاد الجائز (150*300*2000) mm وذلك من أجل نسبة تسليح عرضي (0-0.27-0.38) %، ومن أجل نسب مختلفة لمجاز القص إلى العمق الفعال(a/d=2-2.5-3). تم قياس السهم في منتصف الجوائز وتحديد قوة القص الحدية تجريبياً وحسابياً وفق بعض الكودات العالمية وبعض الباحثين وتم اقتراح علاقة معدلة على معادلة حساب قوة القص للكود الكندي من أجل الخرسانة ذاتية الاكتناز (SCC).أظهرت النتائج التجريبية بأن قوة القص الحدية للجوائز الخرسانية ذاتية الاكتناز كانت أكبر من قوة القص الحدية للجوائز الخرسانية العادية في حال عدم وجود تسليح قص على الرغم بأن مقاومة الضغط ومقاومة الشد بالانحناء البسيط والشد بالفلق أكبر في الخرسانة العادية بالمقارنة مع الخرسانة ذاتية الاكتناز، وقد بلغ متوسط الزيادة (8.7%)، وأظهرت النتائج بأن قوة القص الحدية للجوائز ذات الخرسانة العادية كانت أكبر من قوة القص الحدية للجوائز ذات الخرسانة ذاتية الاكتناز في حال وجود تسليح قص، وقد بلغ متوسط الزيادة (13.4%). تم رسم العلاقة (الحمولة-السهم) من التجارب ومن ثم حساب السهم باستخدام عزم العطالة الفعال. تم إدخال عامل تصحيح مقترح (k) على القيم الحسابية وبمقارنة القيم الحسابية المصححة مع القيم التجريبية وجد أن الفرق الوسطي لا يتجاوز القيمة (6.3%) في الجوائز الخرسانية ذاتية الاكتناز و(10.9%) في الجوائز الخرسانية العادية