This paper describes a numerical study of natural convection heat transfer and fluid flow characteristics inside a cavity with wavy vertical walls. The bottom wall is heated by spatially varying temperature and other three walls are kept at cooled temperature. Governing equation was discretized using the finite volume-method with staggered variables arrangement in curvilinear coordinates. Two geometrical configurations were used in this study for symmetrical and unsymmetrical wavy vertical walls (total of 132 cases) for range of Ra=100 to 106 and fixed Prandtl number (0.71). The effects of the wave geometry, wave amplitude, number of undulation, and Rayliegh number on flow behavior, thermal field, local Nusselt number and Nusselt number
... Show MoreThree revolutions characterize the age of information: Information Revolution,Technology Revolution and Media Revolution. These revolutions developed and interacted with each other in an amazing way. Way to an extent that it becomes a title to our
contemporary architecture. These revolutions changed people‟s thoughts, behaviors, and traditions. The effect of technology on the urban structure generally and the urban space specifically changed the physical structure of these spaces as a necessary result to the change of intellectual structure in community. The information revolution changed a lot of the common urban space„s characteristics and concepts as well as an extreme change in concepts related to the space.
The new though
The verse (35) in SURA (AL- Nur) in the HOLY QURAN has inspired the author to look into the possibility of using Olive Oil as active dye laser material. Olive Oil which is classified as organic compound, having a good properties candidate it to be used as active dye laser material. The emission spectrum diagrams at some of absorption peaks (414, 536, 632 and 670) nm will be measured. These diagrams have been used to determine the Fluorescence quantum yield, Oscillator strength, Einstein coefficients for the spontaneous emission, Radiative and Fluorescence lifetime and absorption and cross sections. It has been found that fluorescence occurs at 669 nm for the entire absorption spectrum. Fluorescence of Olive Oil has been experimented usin
... Show MoreThe hydrodynamic and thermal boundary layers have great effect on the fluid flow and heat transfer between rotating turbine blade. In the present work, the flow and heat transfer is analyzed numerically by solving two dimensional incompressible boundary layer equations. A ( k – ε ) turbulence modeling is used to obtain the eddy viscosity. The finite volume method is introduced to carryout all computational solution with staggered grid arrangement. Due to complex physical domain the original coordinate system is transferred to non orthogonal coordinate system. The calculation of present work done for rotating two dimensional turbine cascade with different rotating speeds (1500 rad/s, 1800 rad/s, 1900 rad/s), and for different Reynolds
... Show Moreجاءت فكرة البحث من اهمية موضوع استهلاك الطاقة في المدن حيث تواجه مدن العالم بشكل عام والمدن العراقية بشكل خاص تحديات بيئية كبيرة من تصاعد نسبة الانبعاثات الكربونية مما يستوجب ايجاد الحلول اللازمة من خلال فهم عملية مدخلات ومخرجات المدينة المتمثلة بعملية الايض الحضري والغازات الدفيئة وانواع مصادر الطاقة وقياس بصمة الطاقة لمنطقة الدراسة وعلاقة استعمالات الارض في استهلاك الطاقة وتوصل البحث الى عرض النتائج ا
... Show MoreThe behaviour of batter piles under inclined compressive loads is of considerable importance,yet, not enough information is available in literature on the subject. The tests canied out in this paper were performed on a single inclined pile under various load inclinations in sand. The results indicate that the highest ultimate compressive load for vertical pile occurs at (30) load inclination. At small load inclinations, a positive batter pile has greater ultimate compressive load than that of a negative batter pile. The trend changes at higher Ioad inclinations. The slip surface analysis is recognised to be too complicated to have a definite
solution.
The superhcater zone of the boiler is the convective heat transfer region of the boiler, that is the heat in this region mostly transferred by the convection between the flew gases outside and steam inside tubes. The factors that effected the heat transfer rate and heat transfer coefficient in the Mosiab power station boiler (980000kgihr capacity under pressure of 175bar) at its superlieater is studied here. The super heater is divided into two parts, primary and secondary super heater. Each part is
divided into many zones depending on the pipe size and material. The effect of boiler load mass flow rate of steam on the heat transfer rate, heat transfer coefficient, steam temperature is studied. It is concluded that as the load on the
This research deals with the stress analysis of typical underground tunnels using isoparametric finite elements. Enhanced soflware is used for predicting and analyzing this behavior by using a single phase formulation. This software was developed from an original Computer code namea MXOYN The finite element method is used to solve the dynamic equiiibrium equation with step-by-step tirre
integration schemes. A selected type of dynamic load was chosen which is blast loading. Frictional and paniculate materials, i.e., concrete and soil, are considered. The soil and concrele structures arc analyzed where a dynamic elastic model for concrete and a linear elastic one for soil are used. The soil is further analyzed by a bounding surface
This paper describes a stego system in which a gray scale image is embedded in another one.Wavelet transform of both the cover image and the embedded image is used to sort their subbands energies to guarantee that the embedded image will be inserted in the low frequency components of the cover image with little perceptual distortion. Embedding by this way increases the robustness of the system but affects the syster 1 imperceptibility, so a variable scaling factor (a) is used to attenuate the components of the embedded image before adding them to those of the cover image. It is found that the stego image with peak signal-to-noise ratio (PSNR) of about 30 dB has goo 1 imperceptibility.The attacker is proposed to be act
... Show MoreA new systematic approach is introduced and used to define and study the basic concepts of the anti-virus system. These basic concepts include definitions, design and analysis criteria, and lassifications. Also, the characteristics of the ideal anti-virus system are defined. To understand how the proposed design and analysis criteria can be used in practice, the currently available antivirus products are analyzed using the proposed criteria to see whether they meet the requirements of the ideal anti-virus system or not.
The major of DDoS attacks use TCP protocol and the TCP SYN flooding attack is the most common one among them. The SYN Cookie mechanism is used to defend against the TCP SYN flooding attack. It is an effective defense, but it has a disadvantage of high calculations and it doesn’t differentiate spoofed packets from legitimate packets. Therefore, filtering the spoofed packet can effectively enhance the SYN Cookie activity. Hop Count Filtering (HCF) is another mechanism used at the server side to filter spoofed packets. This mechanism has a drawback of being not a perfect and final solution in defending against the TCP SYN flooding attack. An enhanced mechanism of Integrating and combining the SYN Cookie with Hop Count Filtering (HCF) mech
... Show MoreThis work presents mainly the buckling load of sandwich plates with or without crack for different cases. The buckling loads are analyzed experimentally and numerically by using ANSYS 15. The experimental investigation was to fabricate the cracked sandwich plate from stainless steel and PVC to find mechanical properties of stainless steel and PVC such as young modulus. The buckling load for different aspect ratio, crack length, cracked location and plate without crack found. The experimental results were compared with that found from ANSYS program. Present of crack is decreased the buckling load and that depends on crack size, crack location and aspect ratio.
Baghdad city has been faced numerous issues related to freshwater environment deteriorations due to many reasons, mainly was the discharge of wastewater without adequate treatment. Al-Rustamiya Wastewater Treatment Plant (WWTP) have been constructed among many plants in Baghdad city to reduce the amount of wastewater discharged into natural environment and its subsequent adverse effects. This study was conducted to evaluate the performance of the plant which consist of a conventional activated sludge (CAS) and sequencing batch reactors (SBR) systems as secondary treatment units and its ability to meet Iraqi specifications. A reliability level determination and analysis also were conducted to find the plant's stability an
... Show MoreThere is no access to basic sanitation for half the world's population, leading to Socioeconomic issues, such as scarcity of drinking water and the spread of diseases. In this way, it is of vital importance to develop water management technologies relevant to the target population. In addition, in the separation form of water treatment, the compound often used as a coagulant in water treatment is aluminum sulfate, which provides good results for raw water turbidity and color removal. Studies show, however, that its deposition in the human body, even Alzheimer's disease, can cause serious harm to health and disease development. The study aims to improve the coagulation/flocculation stage related to the amount of flakes, i
... Show MoreTo damp the low-frequency oscillations which occurred due to the disturbances in the electrical power system, the generators are equipped with Power System Stabilizer (PSS) that provide supplementary feedback stabilizing signals. The low-frequency oscillations in power system are classified as local mode oscillations, intra-area mode oscillation, and interarea mode oscillations. Double input multiband Power system stabilizers (PSSs) were used to damp out low-frequency oscillations in power system. Among dual-input PSSs, PSS4B offers superior transient performance. Power system simulator for engineering (PSS/E) software was adopted to test and evaluate the dynamic performance of PSS4B model on Iraqi national grid. The res
... Show MoreThe Depleted Uranium contamination in soil was treated with chemical leaching method by using sodium bicarbonate with respect to the effect of several variables (Time, Temperature, Bicarbonate Concentration, Carbonate/Bicarbonate Ratio, Oxidative Reagent Effect, pH, Soil/Solution Ratio and Rinsing Effect after treatment) in order to decontaminate or remove Depleted Uranium to acceptable regulatory levels.
The objective is to reach a selectively extracted Depleted Uranium by using a soil washing/extraction without generating a secondary waste which would be difficult to manage and/or dispose off. Results of Depleted Uranium removal efficiency were ranged from (35.4-88.25) %.
The design and construction of an instrumented heat pipe H.P for domestic heating that uses water as a working fluid was undertaken to investigate experimentally the performance of the H.P under various operating conditions of: Power levels, water inventories and angle of inclinations. A theoretical model to predict the temperature of the condenser surface (the temperature at which heat is rejected) and system pressure at steady state conditions was developed and used to compare these parameters with the experimental findings. The model utilizes the total heat supplied to the evaporator to predict system pressure and condenser temperature. The theoretical model is suitable for vertical H.P (i.e. =0) and its predictions of condenser s
... Show MoreA numerical calculations algorithm has been developed in the present work for a thermodynamics and aerodynamic design of an axial flow compressor. The design calculations were based on thermodynamics, gas dynamic, fluid mechanics, aerodynamic and empirical
relations. A two- dimensional compressible flow is assumed with constant axial and rotor blade velocities. A free –vortex swirl distributions was used in the design. These calculations include; power of the compressor, thermodynamic properties of the working fluid, stage efficiency, number of rotor and stator blades, tip and hub diameters, blade dimensions (chord, length and space) for
both rotor and stator, velocity triangles before and after the rotor, Mach number, solidity
The research investigates the term innovation and its role in elaborating architectural practice based on diffusion. The complexity of the architectural field compared with other fields shows a problem in explaining how innovations in architecture diffuse as a thought and act in a certain context of practice. Therefore, the research aims to build an intellectual model that explains the way personal thoughts resembled by unique models introduced by creative and innovator designers diffuse in a certain pattern elaborate these models into a state of prevailing thought resembled by the movement in architecture. The research will apply its model to the more comprehensive movement in architecture, which is the modern movement,
... Show MoreFilm condensation of steam on a vertical tube is investigated numerically and experimentally,
in the present work. A mathematical model was set based on the basic conservation laws of mass
and energy, Nusselts analysis of film condensation, and empirical equations available in the
literature. Then, a simulation program in FORTRAN language was developed which simulates the
film condensation of steam on a vertical tube. A complete steam tables subprogram
... Show MoreAn experimental study is conducted to investigate the effect of heat flux distribution on the boiling safety factor of its cooling channel. The water is allowed to flow in a horizontal circular pipe whose outlet surface is subjected to different heat flux profiles. Four types of heat flux distribution profiles are used during experiments: (constant distribution profile, type a, triangle distribution profile with its maximum in channel center, type b, triangle distribution profile with its maximum in the channel inlet, type c, and triangle distribution profile with its maximum in the channel outlet, type d). The study is conducted using heat sources of (1000 and 2665W), water flow rates of (5, 7 and 9 lit/min). The water
... Show MoreThis study aims at identifying the notion of Post-Occupancy Evaluation (POE) pertinent to the performance of three general hospitals constructed inside the Sulaimani City, tracing the relationship between the quality of the indoor environments and medical staff (doctors and nurses) satisfaction level. Using some indoor environment elements in the right way will positively influence the mood, stress level of the medical staff, and patient recovery as a result. The POE toolkits (AEDET and ASPECT) have been implemented on targeted wards at the selected hospitals. AEDET and ASPECT questionnaires were distributed among 152 medical staff to obtain their perspectives. In total, 112 valid questionnaires were received. The medica
... Show MoreA theoretical study for a three-dimensional natural convection heat transfer from an isothermal horizontal , vertical and inclined heated square flat plates (with and without circular hole) has been done in the present work. The study involved the numerical solution of the transient Navier-Stokes and energy equations by using finite deference method (F.D.M.). The complete Navier-Stokes
equation are transformed and expressed in terms of vorticity-vector potential. The Energy and Vorticity equations were solved by using an Alternating Direction Implicit (ADI) method because they are transient equations of parabolic portion, and the Vector potential is solved by using an equations Successive Over-Relaxation (S.O.R) method because it i
Cathodic protection is a corrosion-prevention technique which uses the electrochemical properties of metals to insure that the structure to be protected becomes the cathode of an electrolytic cell.
Laboratory evaluation was conducted on zinc electrode as anode material that used for sacrificial anode cathodic protection (SACP)of carbon steel.
Rate of zinc consumption during cathodic protection of carbon steel pipeline carrying seawater (4 % w/v NaCl solution) were measured by the loss in weight technique. Variables studied were seawater temperature (0-45o C), flow rate (5-900 lit/h), pH (2-12) and duration time (1-4 h). It was found that the rate of zinc consumption increases with increasing seawater temperature, flow rate and dura
The dynamics of dual-spin spacecraft which containing a proposed nutation damper which consisting of a ring totally filled with a viscous liquid with offset center, to improve damping, is investigated. The equations of motion were developed using Newton-Lagrange approach resulting equations in terms of spacecraft's and damper's parameters, which are given in dimensionless form. The expression of the nutation angle and time constant in both modes are developed using zero-order approximation technique. The equilibria states and stability condition, and the analytical expression for residual nutation angle were derived. The analytical results were compared with those found numerically using computer simulation program named MATLAB, ver. 7.
... Show MoreInfrastructure, especially wastewater projects, plays an important role in the life of residential communities. Due to the increasing population growth, there is also a significant increase in residential and commercial facilities. This research aims to develop two models for predicting the cost and time of wastewater projects according to independent variables affecting them. These variables have been determined through a questionnaire distributed to 20 projects under construction in Al-Kut City/ Wasit Governorate/Iraq. The researcher used artificial neural network technology to develop the models. The results showed that the coefficient of correlation R between actual and predicted values were 99.4% and 99 %, MAPE was
... Show MoreAsmari is the main productive reservoir in Abu Ghirab oilfield in the south-east part of Iraq. It has history production extends from 1976 up to now with several close periods. Recently, the reservoir suffers some problems in production, which are abstracted as water production rising with oil production declining in most wells. The water problem type of the field and wells is identified by using Chan's diagnostic plots (water oil ratio (WOR) and derivative water oil ratio (WOR') against time). The analytical results show that water problem is caused by the channeling due to high permeability zones, high water saturation zones, and faults or fracturing. The numerical approach is also used to study the water movement insi
... Show MoreIn this study water quality was indicated in terms of Water Quality Index that was determined through summarizing multiple parameters of water test results. This index offers a useful representation of the overall quality of water for public or any intended
use as well as indicating pollution, which are useful in water quality management and decision making. The application of Water Quality Index (WQI) with ten physicochemical water quality parameters was performed to evaluate the quality of Euphrates River water for drinking usage. This was done by subjecting the water samples collected from seven stations within Al-Anbar province during the period 2004-2010 to comprehensive physicochemical analysis. The ten physicochemical paramete
This study examines the behavior of fatigue crack propagation in aluminum alloy sheets used in aircraft wings, with a particular focus on critical angles of attack (AOA). The widely utilized aluminum alloys 2024-T3 and 7075-T6 were analyzed to determine the effects of varying AOAs, representing normal flight (5°) and takeoff/landing (10°) on crack growth rates. A comprehensive approach was adopted, integrating experimental testing, numerical simulations, and analytical modeling. Experimental methods included material characterization and multiaxial fatigue tests using an innovative apparatus. Numerical simulations conducted with ANSYS 2021 CFD evaluated stress distributions and crack propagation under different wind lo
... Show MoreThe evolution in materials’ technology in the last decades resulted in interesting projects that aimed at preserving the environment and energy and reduce pollution. They have been taken the principles of environmental design as a basis for architectural thought, starting from the early stages of the design process ending in choosing appropriate building materials to achieve sustainable buildings, but these trying are limited in our local environment and there isn’t demanded seriousness. The research problem emerges in the ignorance of the environmental aspect (ecological system) when selecting building materials during design process to achieve sustainable buildings. The aim of this research is revealing the mechanisms of selecting
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