A CFD Investigation of the Hydrodynamic Characteristics of Fluid Flow through an Impeller and Multi-Objective Design Optimization of a Centrifugal Pump

In this thesis, the first part is conducting an investigation of the hydrodynamic characteristics (pressure and velocity) of fluid flow (water) through an impeller of a centrifugal pump. To illustrate a one-dimensional model is used to identify an impeller of a GDM 10 x 12 HD centrifugal pump using Vista CPD design and BladeGen tool. A three-dimensional model is then built with a commercial software package ANSYS Blade Modeler. The structured mesh of the impeller blade is obtained by using TurboGrid system. The volute of the centrifugal pump is built in ANSYS geometry, and an unstructured mesh is accomplished by using a very fine mesh. Afterwards, Computational Fluid Dynamics (CFD) is applied in ANSYS-CFX to set output parameters of objectives and constraints of the centrifugal pump GDM 10 x 12 HD impeller and volute to get optimum values of efficiency, total head and performance. In addition, the objective of this research is to maximize the efficiency and the total head for the centrifugal pump GDM 10 x 12 HD, making sure that the performance target does not exceed the value of the relative ratio of outlet and inlet pressure so that the head losses do not increase. The CAD modeler of the impeller, with inlet and outlet angles, are modeled using BladeGen modeler. The efficiency and the head of the standard centrifugal pump is observed to be 61% and 42.6 m respectively. Finally, HEEDS MDO-Modeler is used to perform the multi-objective optimization process to obtain the optimal results of the pump efficiency and the head. After optimization the efficiency of the centrifugal pump is increased by 3.2% and the optimized head is decreased by 2% as compared to baseline values. In addition, the blade thickness and the volute are decreased by 13.5% and 10.2% respectively from the original values

Reactive approach for automating exploration and exploitation in ant colony optimization

Ant colony optimization (ACO) algorithms can be used to solve nondeterministic polynomial hard problems. Exploration and exploitation are the main mechanisms in controlling search within the ACO. Reactive search is an alternative technique to maintain the dynamism of the mechanics. However, ACO-based reactive search technique has three (3) problems. First, the memory model to record previous search regions did not completely transfer the neighborhood structures to the next iteration which leads to arbitrary restart and premature local search. Secondly, the exploration indicator is not robust due to the difference of magnitudes in distance matrices for the current population. Thirdly, the parameter control techniques that utilize exploration indicators in their feedback process do not consider the problem of indicator robustness. A reactive ant colony optimization (RACO) algorithm has been proposed to overcome the limitations of the reactive search. RACO consists of three main components. The first component is a reactive max-min ant system algorithm for recording the neighborhood structures. The second component is a statistical machine learning mechanism named ACOustic to produce a robust exploration indicator. The third component is the ACO-based adaptive parameter selection algorithm to solve the parameterization problem which relies on quality, exploration and unified criteria in assigning rewards to promising parameters. The performance of RACO is evaluated on traveling salesman and quadratic assignment problems and compared with eight metaheuristics techniques in terms of success rate, Wilcoxon signed-rank, Chi-square and relative percentage deviation. Experimental results showed that the performance of RACO is superior than the eight (8) metaheuristics techniques which confirmed that RACO can be used as a new direction for solving optimization problems. RACO can be used in providing a dynamic exploration and exploitation mechanism, setting a parameter value which allows an efficient search, describing the amount of exploration an ACO algorithm performs and detecting stagnation situations

Adaptive Steering and Trajectory Control of Wheeled Mobile Robots for Autonomous Navigation

This chapter presents a new reactive navigation algorithm for a wheeled mobile robot (WMR) with a differential drive mechanism moving in unknown environments [1]. The mobile robot is controlled to travel to a predefined goal position safely and efficiently without any prior map of the environment. The navigation is achieved by modulating the steering angle and turning radius. To avoid obstacles while seeking the goal position, the dimensions and shape of the robot are incorporated to determine the set of all possible collision-free steering angles. The algorithm then selects the optimum steering angle candidate to contour the obstacle. Simulation and experimental results on a WMR prototype are used to validate the proposed algorithms

A Review Paper on Concrete-Filled Aluminum Tubular Columns

ان الهدف من مقال المراجعة هذا هو تلخيص التقارير والبحوث والرسائل والاطاريح وبحوث المؤتمرات التي تعاملت مع سلوك الاعمدة المركبة من الخرسانة والالمنيوم. لقد اُستخدمت مقاطع الالمنيوم المجوفة المملوءة بالخرسانة كأعمدة مركبة نظراً لمقاومتها للتآكل وسهولة انتاجها ومظهرها وخفة وزنها. هناك العديد من البحوث التي اٌجريت عن موضوع المقاطع المجوفة المملوءة بالخرسانة، ومع ذلك فقسم قليل منها قد اُجري عن مقاطع الالمنيوم المجوفة المملوءة بالخرسانة. تم في هذه المراجعة تلخيص مختلف البحوث المنشورة والمتوفرة عن هذا الموضوع وذلك لبيان نوع أعمدة الالمنيوم-الخرسانة المدروسة والمتغيرات الرئيسة المؤثرة على سلوك هذه الاعمدة المركبة. وقد تم جمع وعرض أكثر من (190) نموذج في هذه المراجعة.The aim of this review paper is to summarize available reports, papers, theses, dissertations and conference papers dealing with the performance of aluminum-concrete composite columns. Hollow aluminum sections filled with concrete have been used as composite columns due to their corrosion resistance, easy production, appearance and lightweight. Many researches were performed in the area of concrete-filled hollow sections (tubes). However, there are few researches have been performed on concrete-filled aluminum tubes. In this review, different available published papers are summarized to view the type of the studied aluminum-concrete columns and the main studied parameters that affecting the behavior of these composite columns. More than (190) specimens are collected and showed in this review

Effect of the Source of Sedimentation in the Mineralogical Composition of the Sand Fraction to Some Areas of the Southern Part of the Iraqi Alluvial Plain

This study was conducted to know the effect of the source of sedimentation in the mineralogical composition of sand fraction for some areas of the southern part of the Iraqi alluvial plain. The results of mineralogical composition of sand fraction showed that the dominant minerals, in the light part of sand fraction, were carbonate rock fragments , qurtz , chert , mudstone rock , feldspars , igeous and metamorphic rocks . While , the heavy part showed a similarities in terms of quality and differences in terms of quantity , with dominance of Opaque minerals followed by Staurolite , Kyanite , Rutile , and Tourmaline . In general, the results showed the low rates of the heavy metal group compared to the light metals group of the sand fraction resulting from weathering occurring in their moving places during transportation or after the deposition, this may be attributed to the nature of the mineralogical composition of the deposits material source. Keywords: sediments , minerals , sand fraction , Microscopic characteristics , optical of minerals , petrographic microscope , petrograph

Biological Effect of ZnO Nanoparticles on the Vitality of Genus Penicillium spp.

The objective of this study was to clarify the biological effect of ZnO  nanoparticles on the vitality of one of opportunistic fungi ,Penicillium spp. ZnONPs with size ≤50nm and concentrations of (0,3,6 and 12)% were used .Radial growth and dry weight ,were used to estimate the biological effects .Antibacterial effect of the fungus grow in present of ZnONPs were also investigated  .Result ,showed nano-ZnO having stimulate activity on the Penicillium spp. and increasing in activity against of bacteria.  Thus , this study indicates nanoZnO having stimulated activity for Penicillium spp.. Keywords : ZnO, nanoparticles ,Penicillium spp., Staphyllococcus sp.,Antibacterial

Hybrid bat-ant colony optimization algorithm for rule-based feature selection in health care

Rule-based classification in the field of health care using artificial intelligence provides solutions in decision-making problems involving different domains. An important challenge is providing access to good and fast health facilities. Cervical cancer is one of the most frequent causes of death in females. The diagnostic methods for cervical cancer used in health centers are costly and time-consuming. In this paper, bat algorithm for feature selection and ant colony optimization-based classification algorithm were applied on cervical cancer data set obtained from the repository of the University of California, Irvine to analyze the disease based on optimal features. The proposed algorithm outperforms other methods in terms of comprehensibility and obtains better results in terms of classification accuracy

A Review on Flat Slab Punching Shear Reinforcement

يتكون نظام البلاطة المسطحة من صفيحة خرسانية مثبتة على أعمدة دون وجود عتبات. خلال القرن الماضي، استخدمت البلاطات المسطحة على نطاق واسع في أنواع مختلفة من المباني. بشكل عام، تصنع البلاطات المسطحة من مواد هشة ذات عمق محدود؛ وبالتالي، قد تخضع للفشل بسبب قوى القص أو انحرافات عالية. ولذلك، يجب اخذ هذه المعايير بعين الاعتبار عند تصميم البلاطات المسطحة وان تجاهل اي منهما قد يؤدي إلى انهيار العديد من المباني كما حصل في الماضي. لتحسين أداء البلاطة المسطحة ضد الفشل نتيجة قوة الاختراق اوالانحرافات، لا بد من توفير تسليح إضافي في منطقة العمود. في هذا البحث، سيتم تقديم مراجعة لدراسة آلية قص الاختراق في البلاطات المسطحة ووصف أنواع التسليح المختلفة التي تستخدم في التعزيز ضد قص الاختراق.Flat slab system is a concrete plate propped on columns without the existence of beams. During the former century, flat slabs have been used widely in different building types. In general, flat slabs are made from brittle materials and also have a finite depth; thus, flat slabs may undergo to fail due to punching shear or high deflections. Therefore, these criteria should be considered in the design of flat slabs and ignoring both of them had led to several crumbling down to many constructions in the past. To enhance the flat slab performance against failure due to punching and deflections, additional reinforcement should be supplied in the column region. In this paper, a review is presented to study the mechanism of punching shear in flat slabs and describe different types that used for reinforcement against punching shear

Evaluation Study of Free Spanning Subjected to Hydrodynamic Loads

 تحدث ظاهرة الفضاء المعلق الغير مسنود بصورة عامة عند مد خطوط الأنابيب على ارض متموجة التي تحدث نتيجة لعوامل التعرية للتربة المحيطة بالأنبوب المكشوف الغير مدفون. لذلك من الضروري دراسة حركة المائع حول خط الانبوب المتولدة وحساب مقدار الهطول والاجهادات المتولدة لهكذا نوع من خطوط الأنابيب الغائصة تحت الماء. في هذا البحث تم تسليط الجهد لتخمين وتحري الاجهادات خلال جزء الأنبوب المعلق الغير مستند على تربة قاع البحر ودراسة تأثير خصائص هذه التربة عند نقاط الاستناد على سلوك خطوط الأنابيب. تم عمل نموذج لفضاء الأنبوب المعلق باستخدام برنامج (ANSYS) الذي يعتمد على نظرية العناصر المحددة وكذلك تم إدخال تأثير حركة الموجة والتيار لغرض وصف البيئة المحيطة بالأنبوب بدقة اكبر. بينت النتائج المستحصلة من الدراسة ان شدة الاجهادات تتزايد كلما اقتربنا إلى مركز الفضاء الحر.Suspended spans generally occur in subsea pipelines as a result of the irregularity of seabed. Additionally the suspended spans mostly result from the scouring phenomena around the installed non-buried pipeline. So as to discuss the hydrodynamic surrounding the pipeline and determining the significant deflections and associated stresses of the subsea pipeline in unsupported part, therefore, it’s very necessary to study the hydrodynamic surrounding the pipeline in detail. A two main aims have been done in this study, first assess the stresses at free span section and the second one was the effect of soil characteristics in contact area between pipeline and the seabed soil. A combined model of stresses/lateral displacement has been made. An ANSIS model has been built on the offshore pipelines as a consequence of the combined hydrodynamic loads such as wave/current effects. The calculations have been computed by using the finite element method for the free span to describe the surrounding environment in more accuracy. The pipeline stresses intensity increases with closing to free span center. This is attributed to the fact that UY and UZ have more maximum values at these region

The Effect of Peer-Assessment Method in Enhancing Iraqi EFL University Students’ Language Ability

The present study aims at finding outthe effect of using peer assessment method on enhancing Iraqi university EFL students'language ability. To fulfillthe aim of this study, forty fourth- year students were selected to be the sample of the present study. Twenty students were enrolled in an experimental group that received instruction on peer-assessment. The other twenty students were enrolled in a control groupwhich was instructed on self-assessment. To collect data,apre-posttest technique was used.The findings indicate that the experimental group subjects’performanceinspeaking has been found to be better than that of the control group in the post-test.In the light of the results obtained,it is concluded that peer-assessmentis effective inenhancing language ability ofIraqi EFL learners