Flutter is a phenomenon resulting from the interaction between aerodynamic and structural dynamic forces and may lead to a destructive instability. The aerodynamic forces on an oscillating airfoil combination of two independent degrees of freedom have been determined. The problem resolves itself into the solution of certain definite integrals, which have been identified as Theodorsen functions. The theory, being based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing-ection theory relating to the steady case. The mechanism of aerodynamic instability has been analyzed in detail. An exact solution, involving potential flow and the adoption of the Kutta condition, has been analyzed in detail. Th

This paper studies the adaptive coded modulation for coded OFDM system using punctured convolutional code, channel estimation, equalization and SNR estimation. The channel estimation based on block type pilot arrangement is performed by sending pilots at every sub carrier and using this estimation for a specific number of following symbols. Signal to noise ratio is estimated at receiver and then transmitted to the transmitter through feedback channel ,the transmitter according to the estimated SNR select appropriate modulation scheme and coding rate which maintain constant bit error rate
lower than the requested BER. Simulation results show that better performance is confirmed for target bit error rate (BER) of (10-3) as compared to c

Porous asphalt paving is a modern design method that differs from the usual asphalt pavements' traditional designs. The difference is that the design structure of porous pavements allows the free passage of fluids through their layers, which controls or reduces the amount of runoff or water accumulated in the area by allowing the flow of rain and surface runoff.  The cross-structure of this type of paving works as a suitable method for managing rainwater and representing groundwater recharge. The overall benefits of porous asphalt pavements include environmental services and safety features, including controlling the build-up of contaminated metals on the road surface, rainwater management, resistance to slipping ac

An experimental study on a KIA pride (SAIPA 131) car model with scale of 1:14 in the wind tunnel was made beside the real car tests. Some of the modifications to passive flow control which are (vortex generator, spoiler and slice diffuser) were added to the car to reduce the drag force which its undesirable characteristic that increase fuel consumption and exhaust toxic gases. Two types of calculations were used to determine the drag force acting on the car body. Firstly, is by the integrating the values of pressure recorded along the pressure taps (for the wind tunnel and the real car testing), secondly, is by using one component balance device (wind tunnel testing) to measure the force. The results show that, the avera

Many Network applications used as remote login have some ways for detecting the intruders which are classical ways applied by comparison of operations between login user interface and system stored information. The proposed system tried to detect the intrusions happened by the network intruders using new technique called Adaptive Fuzzy Neural Network which have the ability to detect the intrusions at the same time even if the number of users is large. The proposed system consists of two stages, the first stage is for monitoring all events that happen and analyzing them, and the second stage is to detect intrusions. The detection operation combines anomaly intrusion detection and misuse intrusion detection using the Adaptive Fuzzy Neural

The inhibition of copper corrosion by Naphthylamine (NA), Ethylenediamine (EDA), Tetraethylenepentamine (TEPA), Diethylenetriamine (DETA), and Phenylenediamine (PDA) in 5% HCl have been investigated by weight loss technique at different temperatures. The results were compared with Benzotriazole (BTA), the common inhibitor used for inhibition of copper corrosion in different environments. The BTA film formed on the copper surface obeys Langmuir Adsorption Isotherm. While NA, EDA, TEPA, and DETA appear to obey the Freundlich Adsorption Isotherm. In the other hand, the two-adsorption isotherms were unsuitable to represent the data of PDA. Results also showed that the Kinetic-Thermodynamic Model was suitable to fit the experimental data of t

This research intents to design and laboratory implementation of a power electronic converter, which is useful for home applications, industrial, communications, street light and water pumping using solar cell source. The design is based on a step up boost DC/DC converter followed by a full wave SPWM inverter. The nominal power rating is 1.25kW and can operate from any DC source such as DC battery besides fuel cells. The system which consists of the following stages (PV, converter, inverter, DC link, filter and snubber circuit), is designed primarily with a general module depending on Orcad PSPICE program to produce power output nearly 1.25kVA at 50Hz with a pure sinewave output for both voltage and current. After designing and simulatin

تمثل عممية البناء الشكمي لمعمارة الشمسية عممية منيجية تعتمد عمى ما وجود من اساليب تطور ت عمى اساسيا نظم وتفاصيل جديدة تحدد بنية الشكل المثالي الكفوء لحفظ الطاقة ، وتقترب من النظرية الوظيفية في البناء الشكمي كما تتاثر بالنظريات االخرى ،وتتغير من مصمم الى أخر لتحقيق االبداع الشخصي في قضايا الشكل المتعمقة عادة بالحدس الذاتي والتركيز عمى استراتجية دون أخرى واالستفادة من المناورة التصميمية ضمن ماىو ممكن لموصو

An application of neural network technique was introduced in modeling extraction efficiency in RDC column, based on a data bank of around 352 data points collected in the open literature. Three models were made, using back-propagation algorithm, the extraction efficiency was found to be a function of seven dimensionless groups: Weber number (we), (Vd Vc), (c d), (Ds Dt), (Dr Dt), (Zc Dt) and(Zt Zc). Statistical analysis showed that the proposed models have an average absolute error (AARE) and standard deviation (SD) of 12.23% and 10.61% for the first model, 5.35% and 6.21% for the second model, 8.34% and 7.59% for the third model. The developed correlations also show better prediction over a wide range of operating conditions, phys

The present study investigates the removal of the textile dyehouse wastewater [azo dye para red(reactive dye)and M-5R200%(disperse oranges dye)] by Electrocaogulation process. The effect of nature of the anode, current density, initial pH, rate of stirring and concentration of dyes on the removal efficiency were tested.
The experimental results showed that the color of dyes in the aqueous solution was effectively removed when aluminum was used as anodes and the current density 25mA/cm2 , initial pH (3-9),stirring rate 200rpm, and the concentration of dyes was less than 100mg/l. When the concentration of reactive dye exceeded 300mg/l iron was a more suitable anode than aluminum.
For the electrocaogulation of disperse dye in aqueous

Trickle irrigation is a system for supplying filtered water and fertilizer directly into the soil and water and it is allowed to dissipate under low pressure in an exact predetermined pattern. An equation to estimate the wetted area of unsaturated soil with water uptake by roots is simulated numerically using the HYDRUS-2D/3D software. In this paper, two soil types, which were different in saturated hydraulic conductivity were used with two types of crops tomato and corn, different values of emitter discharge and initial volumetric soil moisture content were assumed. It was assumed that the water uptake by roots was presented as a continuous sink function and it was introduced into Richard's equation in the unsaturated z

يبدو الاثر الكبير للمكونات الايكولوجية ..............

When industrial and  constructional renaissance started in the world, the great interest was going on towards the equipment’s,  which was the first mean for production. After industry was settled the interest was going on towards the men ship which manpower on which the production depends. It was approved that it represents the basic part in all of the processes and the protection of those individuals against dangers of these equipment’s, industry and its accidents was the basic things which was studied in many researches until it crystallized in general principles for all industries and other take care in each industry.

     The professional safety is concerned as restrict which

Fractal geometry is receiving increase attention as a quantitative and qualitative model for natural phenomena description, which can establish an active classification technique when applied on satellite images. In this paper, a satellite image is used which was taken by Quick Bird that contains different visible classes. After pre-processing, this image passes through two stages: segmentation and classification. The segmentation carried out by hybrid two methods used to produce effective results; the two methods are Quadtree method that operated inside Horizontal-Vertical method. The hybrid method is segmented the image into two rectangular blocks, either horizontally or vertically depending on spectral uniformity crit

This study aims to derive a general relation between line loads that acting on two-way slab system and the equivalent uniformly distributed loads. This relation will be so useful to structural designer that are used to working with a uniformly distributed load and enable them to use the traditional methods for analysis of two-way systems (e.g. Direct Design Method). Two types of slab systems, Slab System with Beams and Flat Slab Systems, have been considered in this study to include the effect of aspect ratio and type of slab on the proposed relation. Five aspect ratios, l2/l1 of 0.5, 0.75, 1.0, 1.5 and 2.0, have been considered for both types of two-way systems.
All necessary finite element analyses have been executed with SAFE Soft

The authentic traditional architecture proved that it is very convenient to the environmental and social regulations where it appeared and lasted for hundred of years.

This traditional architecture got the intelligence in providing thermal comfort for their occupants by the intelligent usage of the building materials and the intelligent planning and designs which took in consideration the climatic condition and the aerodynamics of the whole city as one ecological system starting from the cold breeze passing through its narrow streets till it enters the dwelling units and glides out through the wind catchers.

This architecture had been neglected and replaced by modern imported architecture which had collap

In this research a modern scientific procedure was used utilizing geographic information system
GIS in selecting the optimum road path between two cities . All the programming facilities offered
by ArcView GIS software with its extensions of spatial analysis and 3D analysis to solve the problem .The solution take a form of geographic map graduated in colors from best to bad portion of land that the suggested road could pass through. The proposed procedure was checked by conventional mathematical solution used in such problems and the results were both agreed.

The need for strengthening structural members is well known and research is progressing in this field. In recent years the use of fiber reinforced polymers (FRP) for strengthening has shown to be a efficient method both regarding structural performance and economical aspects. However, most of the research in this field has been undertaken on concrete of old and damaged structures and for flexural and shear strengthening. So, this paper presents axially loaded steel columns strengthened for increased load capacity and improved stability. The topic is studied theoretically. The theory covers analytical method, and a numerical finite elements (FE) analysis. Different types of most common commercial FRP systems have been examined and used in

This investigation presents a coupled analysis of a dam-reservoir problem which includes all aspects of fluid-structure interaction (class I coupling) and soil-pore fluid–structure interaction (class II coupling) under earthquake excitations using the finite element method.
The analysis involves the compressibility of water, the flexibility of the dam, the earthquake excitation, the structural damping and the material nonlinearity on the response. An efficient computer program in FORTRAN is developed for this analysis from the
original computer code named MIXDYN. The new software for predicting and analyzing the coupled behaviour is established using the pressure formulation for modelling of fluid and the u-p formulation for mo

The main goal of this work is to determine optimal location for placing generating plants in the Iraqi National Super Grid which gives minimum total losses in the system. A package build under Matlab was used to allocate optimal placement of generating sets, calculating active and reactive power for these generators, .calculating system minimum losses, and determine the effect of varying the output of the generators used on losses reduction.

One of the challenges that developing countries is the necessity to properly manage the risks involved in road construction projects. For that, the present work developed a dissension method to specify effective risk factors in a wide range of approaches and protocols to achieve its objectives. The Influence of Risk Road Implementation on Performance Indicators The initial sets of outcomes were derived from computing the average risk estimate. Subsequently, the second results group was established by assessing the relative importance index (RII) effects. In the RII method and mean results the workers and machinery insurance is the most important. The identical data that had been collected from the weighted product model

The present work investigates the effect of some of the variables in spot tungsten inert gas shielded
welding (TIG Spot) for (Aluminum-Magnesium) alloy type(5052-O) which is non–heat treatable
alloy for its wide industrial uses and applications in field of welding technology.
TIG Spot welding was performed by using tungsten electrode (EWTh2)of diameter (3.2mm) and
DC current with direct polarity (DCSP) at constant shielded gas flow rate (15litre/min).
The welded specimens were tested by using the Instron machine to determine the maximum shear
force (shear strength ) of spot welded and to define the optimum conditions of spot welding
variables in relation to the weld current, weld time and arc length of welding to

استخلاص المعالم من السطوح الطبوغرافية هي إنشاء صورة نقطية تمثل ارتفاعات سطح الأرض
بالاعتماد على نموذج الارتفاع الرقمي الذي يعتبر الأساس الذي يعتمد عليه تحليل السطوح الطبوغرافية .
إن نماذج الارتفاعات الرقمية تستنبط بشكل رئيسي بتطبيق النماذج المجسمة ( زوج من الصور) المتوفرة من
المسح التصويري وبيانات التحسس النائي أو من الخرائط الطبوغرافية وهنا تم استخدام نموذج ارتفاع رقمي
مستخلص من الخرائط الطبوغراف

In this work, the effect of variation of semi-angle of the conical part on the vibration characteristics of cylindrical-conical coupled structure is investigated. The shell is made of polyester resin reinforced by continuous E-glass fibers. The case is analyzed experimentally and numerically for orthotropic shell structures. The experimental program is conducted by exciting the fabricated structure by an impact hammer and monitoring the response using an attached accelerometer for different semi-angles of the conical part.
Software named SIGVIEW is used to perform the signal processing on the acquired signal in order to measure the natural frequencies and the corresponding mode shapes. The numerical investigation is achieved using ANS

   Finite element method is the most widely numerical technique used in engineering field. Through the study of behavior of concrete material properties, various concrete constitutive laws  and failure criteria have been developed to model the behavior of concrete. A feature of the Finite Element program (ATENA) is used in this study to model the behavior of UHPC corbel under concentrated load only. The Finite Element (FE) model is followed by verification against experimental results. Some variable effects on the shear capacity of the UHPC corbels are also demonstrated in a parametric study. A proposed design equation of shear strength of UHPC corbel was presented and checked with numerical results.
 

Electrically heated horizontal cylinders of diameters 2.15cm,3cm, and 3.8cm were vibrated vertically in stagnant air at a frequency (10,15,20Hz) and amplitude range from (0.0005m) to (.0076m). The effect of different parameters on the heat transfer ratio (hv/ho) was investigated from its outer surface. It is concluded that, heat transfer ratio increases at high frequency and small diameter. Vibration Reynolds number has good effects on heat transfer ratio. (Gr.Pr) has bad indication on heat transfer ratio at high temperature difference (high heat flow). The vibration intensity also has good influence on heat transfer.

A description is given of the resistance spot welding process in terms of internal behavior of the weld as welding takes place. Heat input due to spot welding of steel sheet plate causes temperature gradient in the parent metal. After cooling, residual stresses appear around the welding zone reducing the strength. Residual stresses are a result of the temperature gradient and the dependency
of material properties on the temperature, such as yield strength, elasticity modulus, and thermal expansion coefficient. Nonlinear transient heat transfer analysis performed in order to obtain the temperature distribution in the welded part .A nonlinear thermo–plastic stress analysis is then performed to predict the stress and strain fields dur

The paper deals with the traveling wave cylindrical heating systems. The analysis presented is analytical and a multi-layer model using cylindrical geometry is used to obtain the theoretical results. To validate the theoretical results, a practical model is constructed, tested and the results are compared with the theoretical ones. Comparison showed that the adopted analytical method is efficient in describing the performance of such induction heating systems.