Thermal buckling analysis of symmetric and antisymmetric cross-ply laminated hybrid composite plates with an inclined crack subjected to a uniform temperature rise are presented in this paper. The first-order shear deformation theory in conjunction with variational energy method is employed in the mathematical formulation. The eight-node Lagrangian finite element technique is used for obtaining the thermal buckling temperatures of hybrid composite laminates. The effects of crack size and lay-up sequences on the thermal buckling temperatures for symmetric and a antisymmetric plates are investigated. The results are shown in graphical form for various boundary conditions. Finally, from this paper, the following main results have been found
... Show MoreAn iterative solution procedure necessarily involves pre- specified convergence criteria to stop teration. The Discrete Differential Dynamic Programming procedure to solve optimization problems formulated by the Dynamic Programming is an iterative solution procedure which, in its traditional form, involves two convergence criteria, namely, (a) and (B). The research used the optimum operation of an existing complex water resources system as a case study. The objective function was formulated as the maximum real monetary return. The formulated optimization model was run for a total of (194) different operation cases. Beside the traditional (a) and (B), seven new styles for a unique convergence criterion were examined in the solution. Consi
... Show MoreThis research is concerned with performance of different shapes (parallel plate, grid, corrugated) and materials (polystyrene, polypropylene, P.V.C, and steel) of packing for an air -water- cooling tower. A Mechanical forced draught counter current flow cooling tower of 300 mm x 300 mm, cross-sectional area and 1.65m height was constructed and studied theoretically and experimentally Air flow rates of 0.533,1.035, and 1.774 kg/m2.s were used in conjunction with water flow rates of 1.686, 2.218, and 2.66 kg/m2.s, and water temperature of 40,45,50 °C. The tower characteristics (KG a Z/L) and the volumetric mass and heat transfer coefficients (Kça, hoa and ha) are found to be a function of the water and air flow rates simultaneo
... Show MoreUncoupled behaviour of a dam undd, earthquake loading is investigated. Three constitutive models are used:. The linear-elastic model where soil properties; shear modulus and damping ratio are strains ar d cycle independent.-The equivalent linear model where soil properties are strain dependent but cycle independert. The shear modulus tends to decrease as the shear strain increases, while the damping ratio tends to increase as the shear strain increases. - A non-linear model where soil properties tend to change not only with shear strain but also with the progression of cycles. In this work, the bounding surface model is used.For these studies, three kinds of umerical integration methods in the time domain are usel. namely, Newmark, Wilso
... Show MoreThis investigation presents an extensive experimental study on the behaviour and strength of reinforced concrete T-beams before and after strengthening by using reinforced concrete jacket. Four full scale beams were first loaded to certain levels of ultimate capacity (0, 60%, 77%, 100% of failure load). Then, after formation of cracks or failure, they were repaired by reinforced concrete jacketing method and tested again up to failure. The main objective of this study is to restore the full ultimate capacity beams failed by flexure and to strengthen the cracked beam. Also, it is aimed to investigate the effect of loading condition on beam before repair on the ultimate capacity after repair. Extensive measurements of deformations, cr
... Show MoreSeries compensation is frequently found on long transmission lines used to improve voltage stability. Due to the long transmission lines, voltage begins to decay as the line moves further from the source. Series compensation devices placed strategically on the line to increase the voltage profile of the line to levels near 1.0 p.u.. This paper presents a novel optimum location and optimum percentage compensation value of a series capacitor as a compensation method to enhance the voltage stability and loss reduction. The proposed method is applied to a 11-bus power system.The load flow analysis using Newton-Raphson approach for the 11-bus test system was designed and tested using MATLAB 7 programming language.
Smear zone is usually formed around the prefabricated vertical drains (PVD’s) due to mandrel driving. The geotechnical properties of the soil in this zone exhibit significant changes that affect the performance of the PVD’s. The most relevant property in this respect is the coefficient of permeability. So far, no serious attention is paid to investigate the effects of shearing under large shear strains on the geotechnical properties of the soft soil in Fao region. In this study, an extensive laboratory testing program was conducted to assess the characteristics of the smear zone with an emphasis on the permeability coefficient of Fao soft soil. The results show that the permeability of the smear zone is about 70% of
... Show MoreAn experimental analysis was conducted to investigate the effect of varying the inlet airflow rate into the drying chamber on the performance of an indirect solar dryer using a forced convection system under the climatic conditions of Baghdad, Iraq, at a latitude of 33.3°N. The dryer performance was tested at three airflow rates (0.0113, 0.0169, and 0.0226) m³/s, using a conventional flat absorber plate and a perforated plate with circular holes of diameter 3 mm. Apricots were dried in all experiments conducted in June 2024. The results showed that the perforated plate significantly enhanced the thermal efficiency of the solar collector compared with that of the flat plate. The perforated plate improved the heat exchan
... Show MoreStatic behavior of three partially encased composite steel beams with cambering under flexural condition is investigated in the context of studying some alternative positions for the headed studs. Shear resistance between the cambered I-shaped beam and the concrete was provided by headed studs in two positions: vertically welded on the bottom flange and horizontally welded on the faces of the web. In the present study, a nonlinear three-dimensional finite element analysis has been used to predict the load-deflection and moment-rotation behaviors of composite encased beams consisting of steel sections using the finite element computer program (ANSYS V. 10). Composite encased beams are analyzed and a comparison is
made with available ex
The effect of using solutions of ethanol and gas-oil (duel fuel) to fuel the diesel engine on engine performance and heat release have been studied experimentally. A single cylinder diesel engine type Recardo (E6/US) was used and the ethanol percentage in the solution was varied from 0 to 20 percent. The results showed that, in general, addition of ethanol to gas-oil cause the maximum power output to decrease at medium and high range of speed and it was nearly the same as that of the straight gas -oil at low speed ranges. The specific fuel consumption of the dual is nearly the same as that of straight gas-oil at low and medium ranges of load. But at high ranges of load the specific fuel consumption was increase. In general, the addition
... Show MoreThe trend towards studying traffic management in software-defined networks (SDN) is increasing widely due to its great importance in enhancing the efficiency of networks and their abilities to adapt to the increasing demands on data and modern applications. What increases the importance of these studies is the integration of artificial intelligence (AI) technologies, which in turn provide intelligent analysis and response capabilities that contribute to improving quality of service (QoS), avoiding congestion, and achieving balanced load distribution across the network. Intelligent management in the SDN controller involves the use of modern algorithms and technologies that have been used previously and have given desirabl
... Show MoreOne of the advanced techniques in enhanced oil recovery (EOR) is the miscible injection of carbon dioxide (CO2), which can both boost oil displacement and decrease the greenhouse effect. One of the most important indicators for ensuring full miscibility between two phases and optimal injection process efficiency is the Minimum Miscibility Pressure (MMP). There are many methods, such as experimental methods, that are accurate yet costly and time-consuming for determining the MMP; thus, researchers often turn to mathematical techniques, including equations of state and empirical correlations. This study aims to determine the minimum miscible pressure for CO2 in one of the Iraqi fields for its import
... Show MoreThis study examines residents’ perceptions, attachments, and preferences for neighborhood improvements in Sulaimani, Iraq, a city undergoing rapid urban transformation. The research aims to address two key objectives: (1) To investigate how residents perceive and attach to their old and current neighborhoods; (2) To explore what are their priorities for neighborhood improvements. Using the TwoStep Cluster model in IBM SPSS Modeler, residents were grouped based on their satisfaction with their neighborhoods and their priorities for architectural and infrastructure enhancements. The findings indicate a dual focus: while residents appreciate modern amenities, such as energy-efficient designs and improved public spaces, th
... Show MoreNumerical investigations of unsteady natural convection heat transfer through a fluid-saturated porous
media in inclined cylindrical enclosure are studied by solving the governing (3-D) Darcy-Boussinesq
equations using finite difference method. The momentum equation of flow was solved by Relaxation method and the energy equation by using Alternating Direction Implicit (ADI) method. The problem is analyzed for modified Rayleigh number with range of (50-300),angles of inclination (0°,25°,45°60°90°), amplitude of sinusoidal temperature (0.2, 0.4, 0.8) and period (0.005, 0.01, 0.02). Results indicate an increase in the heat transfer with increasing of Rayleigh number, time, amplitude, angle of inclination and period. Also average
Dr. Qahtan Al-Madfa’i’s architecture has been characterized by a particular characteristic that may be unique and extreme at the same time, that is the use of the distinctive three-dimensional structural coverings and the exploitation of structural construction to give an extra aesthetic touch to the composition of the building, to achieve the application of his universal ideas, which he strongly believed and defended.
In the period of the marked urban decline that the country undergoes now, which urges us toward making a comparison between the beginning of the modern Iraqi architecture and its ascending path up to its peak and the periods of its decline until it reached a very
... Show MorePredicting Stream flow forecasting is of great interest to engineers and hydrologists for the management and planning in designing water resources projects and for water resources for. Long-term and short-term stream flow forecasting can provide valuable information on the possibility of designing water projects. This paper aims to improve the hydraulic performance selected channel namely the Shatt al-Ibrahim channel by measuring the depth of flow, using an Inflatable dam and comparing it with the water depth before the dam was placed in operational discharge (2 m3/sec). One-dimensional and two-dimensional numerical models are generated and analyzed using HEC-RSA software and then calibration with a physical m
... Show MoreThe heat transfer and flow resistance characteristics for air flow cross over circular finned tube heat exchanger has been studied numerically and experimentally. The purpose of the study was to improve the heat transfer characteristics of an annular finned-tube heat exchanger for better performance. The study has concentrated on the effect of the number of perforations and perforations shapes on the heat transfer and pressure drop across a staggered finned tube heat exchanger. The Numerical part of present study has been performed using ANSYS Fluent 14.5 using SST Turbulent model, while the experimental study consist from a test rig with different models of heat exchangers and all required measurement devices were build
... Show MoreTrickle irrigation is one of the most conservative irrigation techniques since it implies supplying water directly on the soil through emitters. Emitters dissipate energy of water at the end of the trickle irrigation system and provide water at emission points. The area wetted by an emitter depends upon the discharge of emitter, soil texture, initial soil water content, and soil permeability. The objectives of this research were to predict water distribution profiles through different soils for different conditions and quantify the distribution profiles in terms of main characteristics of soil and emitter. The wetting patterns were simulated at the end of each hour for a total time of application of 12 hrs, emitter disch
... Show MorePorcelain is one of the most important ceramic materials with a wide range of traditional and technical applications. Since most mixtures of porcelain have a high sintering temperature, bentonite has been added in this research to improve the characteristics of sintering and burning. The porcelain mixture consisted of the following Iraqi raw materials: 30% wt kaolin, 30 wt% non-plastic clay (grog), 10% wt sodium feldspar, 10 wt% potassium feldspar and 20 wt% flint. After the mechanical mixing process and transfer the powder mixture to the slurry by adding distilled water, then different weight percentage of the sodium bentonite(0, 2.5, 5, 7.5 and 10) wt% was added. The specimens were prepared by using the solid casting m
... Show MoreMost intrusion detection systems are signature based that work similar to anti-virus but they are unable to detect the zero-day attacks. The importance of the anomaly based IDS has raised because of its ability to deal with the unknown attacks. However smart attacks are appeared to compromise the detection ability of the anomaly based IDS. By considering these weak points the proposed
system is developed to overcome them. The proposed system is a development to the well-known payload anomaly detector (PAYL). By
combining two stages with the PAYL detector, it gives good detection ability and acceptable ratio of false positive. The proposed system improve the models recognition ability in the PAYL detector, for a filtered unencrypt
In this study, the effects of different loading doses of cerium in the prepared NaY zeolite from Iraqi kaolin were investigated. Al-Duara refinery atmospheric residue fluid catalytic cracking was selected as palpation reaction for testing the catalytic activity of cerium loading NaY zeolite. The insertion of cerium in NaY zeolites has been synthesized by simple ion exchange methods. Three samples of modified zeolite Y have been obtained by replacing the sodium ions in the original sample with cerium and the weight percent added are 0.35, 0.64, and 1.06 respectively. The effects of cerium loading to zeolite Y in different weight percent on the cracking catalysts were studied by employing a laboratory fluidized
... Show MoreIn this paper, the effect of wear in the fluid film journal bearings on the dynamic behavior of rotor bearing system has been studied depending on the analytical driven of dynamic stiffness and damping coefficients of worn journal bearing. The finite element method was used to modeling rotor bearing system. The unbalance response, critical speed and natural frequency of rotor bearing system have been studied to determine the changes in these parameters due to wear. MATLAB software was used to find the analytical values of dynamic coefficients of journal bearing. The results of rotor mounted on fluid film journal bearings showed that the wear in journal bearing increases the amplitude of unbalance response and decrease critical speed, sta
... Show MoreThe effect of refrigerant injection techniques on the performance of heat pump system based on exergy analysis was studied theoretically. Three refrigerant injection techniques were used; the first was achieved by injected vapour in volume ratios from 1 to 7% in the accumulator. The second was injection liquid refrigerant in the discharge line with the aid of Liquid Pressure Amplification (LPA) pump, with volume ratios from 1 to 10%. The third was a hybrid injection with volume ratios of injected vapour and liquid varied from 1 to 3% and 1 to 10%; respectively. The following improvements in cycle performance were observed. For vapour injection technique, the best ratio of injection was 5%, the exergy destruction reduced
... Show MoreDifferent solvents (light naphtha, n-heptane, and n-hexane) are used to treat Iraqi Atmospheric oil residue by the deasphalting process. Oil residue from Al-Dura refinery with specific gravity 0.9705, API 14.9, and 0.5 wt. % sulfur content was used. Deasphalting oil (DAO) was examined on a laboratory scale by using solvents with different operation conditions (temperature, concentration of solvent, solvent to oil ratio, and duration time). This study investigates the effects of these parameters on asphaltene yield. The results show that an increase in temperature for all solvents increases the extraction of asphaltene yield. The higher reduction in asphaltene content is obtained with hexane solvent at operating conditions of (90 °C, 4/1
... Show MoreIn this work, strains and dynamic crack growth were studied and analyzed in thin flat plate with a surface crack at the center, subjected to cycling low velocity impact loading for two types of aluminum plates (2024, 6061). Experimental and numerical methods were implemented to achieve this research. Numerical analysis using program (ANSYS11-APDL) based on finite element method used to analysis the strains with respect to time at crack tip and then find the velocity of the crack growth under cycling impact loading. In the experimental work, a rig was designed and manufactured to applying the cycling impact loading on the cracked specimens. The grid points was screened in front of the crack tip to measure the elastic-plas
... Show More Heat exchanger is an important device in the industry for cooling or heating process. To increase the efficiency of heat exchanger, nanofluids are used to enhance the convective heat . transfer relative to the base fluid. - Al2O3/water nanofluid is used as cold stream in the shell and double concentric tube heat exchanger counter current to the hot stream basis oil. These nanoparticles were of particle size of 40 nm and it was mixed with a base fluid (water) at volume
concentrations of 0.002% and 0.004%. The results showed that each of Nusselt number and overall heat transfer coefficient increased as nanofluid concentrations increased. The pressure drop of nanofluid increased slightly than the base fluid because
Face Identification is an important research topic in the field of computer vision and pattern recognition and has become a very active research area in recent decades. Recently multiwavelet-based neural networks (multiwavenets) have been used for function approximation and recognition, but to our best knowledge it has not been used for face Identification. This paper presents a novel approach for the Identification of human faces using Back-Propagation Adaptive Multiwavenet. The proposed multiwavenet has a structure similar to a multilayer perceptron (MLP) neural network with three layers, but the activation function of hidden layer is replaced with multiscaling functions. In experiments performed on the ORL face database it achieved a
... Show MoreCorrosion of carbon steel pipe in aerated 0.1N NaCI solution nder isothermal turbulent flow conditions (Reynolds number 15000-113000 and temperature of 30-60°C) is investigated by weight loss method. The effect of Reynolds number and temperature on corrosion rates is experimentally studied and discussed. Corrosion mechanism is analyzed as a mass transfer operation and the corrosion rate is expressed in terms of mass transfer dimensionless groups (Sh and St) and in terms of usual corrosion units. The results of corrosion rates are compared with many proposed models particularly those based on the concept of analogy among mass, heat, and momentum transport by determining experimental friction factor. The capability of these models to expr
... Show MoreThis work implements the' face recognition system based on two stages, the first stage is feature extraction stage and the second stage is the classification stage. The feature extraction stage consists of Self-Organizing Maps in a hierarchical format in conjunetion with Gabor Filters and local image sampling.The next stage is the classification stage, and consists of self-organizing map neural network; the goal of this stage is to find the similar image to the input image. The proposal method algorithm implemented by using C++ packages, this work is successful classifier for a face database consist of 20 people with six images for each person.
The objective of the present paper is to examine the effect of Recycled Asphalt Pavement (RAP) on marshall properties and indirect tensile strength of HMA through experimental investigation. A mixture with 0% RAP was used as a control mix to evaluate the properties of mixes with 5%, 10%, and 15% RAP. One type of RAP was brought from Bab Al-moadam’s road in Baghdad for this purpose. The experimental testing program included Marshall and Indirect Tensile Strength tests. The results indicated that the bulk density, flow and VFA increase with the increasing of the percentage of RAP, while increasing in RAP results decreases in VTM and VMA values. Furthermore, the stability is changed from 10.1 kN for the control mix to12, 13.6 and 11.7 kN
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