In this paper, three types of epoxy-based coatings (Polyamide, pure Polyamine, and Polyamine reinforced by glass-flake) used as a lining for potable water tanks were studied using experimental and finite element methods. Tensile, impact, and fatigue tests were conducted on uncoated and coated AISI 316 stainless steel. The test results show that the applied epoxy based coating improves the mechanical properties, increases of fatigue crack resistance, and enhance the dynamic fracture toughness. The fatigue crack propagation is influenced by the compositions of epoxy coating, and the glass-flake improves the coating resistance to fatigue crack propagation compared to other types.
In this modern Internet era and the transition to IPv6, routing protocols must adjust to assist this transformation. RIPng, EIGRPv6 and OSPFv3 are the dominant IPv6 IGRP (Interior Gateway Routing Protocols). Selecting the best routing protocol among the available is a critical task, which depends upon the network requirement and performance parameters of different real time applications. The primary motivation of this paper is to estimate the performance of these protocols in real time applications. The evaluation is based on a number of criteria including: network convergence duration, Http Page Response Time, DB Query Response Time, IPv6 traffic dropped, video packet delay variation and video packet end to end de
... Show Moreيعد مبدأ التكامل البيئي- الاجتماعي - الجمالي من المبادىء المهمة في تصميم المجمعات السكنية لنمط متعدد الاسر لما
لها من اهمية في وقتنا الحالي بسبب تفاقم ازمة السكن ، وللوصول الى تصاميم تقترب من نمط الاسكان منفرد الاسرة ، مع
الاخذ بالمعلومات والمعطيات والحلول الناجعة والمتراكمة عبر خبرات سنين طويلة والموجودة في تراثنا العربي للمحلة السكنية
التقليدية، على هذا الاساس اعتمد البحث في تقديمه للمشكلة البحثية
By adding a measure of third harmonic to the output of each phase of three-phase inverter, it is possible to obtain a line-to-line output voltage that is 15 percent greater than that obtainable when pure sinusoidal modulation is employed.
The line-to-line voltage is undistorted. The method permits the inverter to deliver an output voltage approximately equal to the voltage of the ac supply to the inverter. Thus an induction motor of standard rating with respect to the ac supply to the inverter can deliver very nearly full power at rated speed when supplied from the inverter. This is achieved without pulse dropping or any other form of mode changing.
For a multicomponent competitive adsorption of furfural and phenolic compounds, a mathematical model was built to describe the mass transfer kinetics in a fixed bed column with
activated carbon. The effects of competitive adsorption equilibrium constant, axial dispersion, external mass transfer and intraparticle diffusion resistance on the breakthrough curve were studied for weakly adsorbed compound (furfural) and strongly compounds (parachlorophenol and phenol). Experiments were carried out to remove the furfural and phenolic compound from aqueous solution. The equilibrium data and intraparticle diffusion coefficients obtained from separate experiments in a batch absorber, by fitting the experimental data with theoretical model. T
the present investigation is concerned with thesevaluation of creep behavior of concrete under variable temperature and relative humidity. It includes analytical and experimental parts. In the analytical part, BP-KX creep model is presented. As this model considers temperature and relative humidity to be constant, it was modified through considering them to be variable with time, which is the usual case. Functions for the daily variation of these two parameters, according to Baghdad climate, were developed and substituted in the model. In the experimental part, three series of cylindrical specimens (100mm x 200mm) were prepared for the creep test. In series (1), the temperature was raised and simultaneously the relative humidity wa
... Show MoreGypseous Soils are distributed in many regions in the world including Iraq, which cover about
(31.7%) of the surface area of the country. Existence of these soils, some times with high gypsum
content, caused difficult problems to the buildings and strategic projects due to dissolution and
leaching of the gypsum slates by the action of water flow through the soil mass.
In this study the effect of treatment with Dihydrate Calcium Chloride (CaCl2.2H2O) as water
solution on compaction, compressibility, leaching, permeability and shear strength characteristics of
Gypseous soil is investigated. It is found that the maximum dry unit weight increases while optimum moisture content decreases with the increase in the concentratio
In this paper a theoretical analysis of South Baghdad and Dura power plant is carried out
according to second law of thermodynamic depending on entropy (irreversibility coefficient or lost work) method instead of exergy (availability) method. In the used entropy method. The power plant is divided into main blocks ( boiler, turbine, condenser, and feed water heater and pumps ). The irreversibility losses and coefficient for each block are calculated and then the overall irreversibility and thermal efficiency of the plant are calculated. The results of this work are compared with previous results, that depending on exergy method. The comparison of results show that both methods give approximately the same results since both of them r
In the present work , a numerical study has been made for the developing compressible turbulent flow and heat transfer in circular tube with uniform injection or suction. The study included the numerical solution of the continuity, momentum and energy equations together with the two equations of the (k-ε) turbulence model, by using the Finite Difference Method (FDM). The air was used as the working fluid, and the circular passage was composed of tube with diameter (20.0) cm , and the length was 130 (hydraulic diameter) .The Reynolds number of the flow was (Re=1.78x106 ), and the Mach number (M=0.44) the ratio of the transverse velocity at the wall (vw) to the axial velocity at inlet (Uin), Ω=(vw/Uin), for suction equal(0.001) and for i
... Show MoreThe waste material problem in today's world has become a major topic affecting all sectors of human life. Researchers are interested in providing solutions for each kind of waste material. Waste glass is one of the waste materials whose amounts increase daily. This article deals with two types of modified cement mortar with glass granular in the masonry wall to find their effect on the wall's property (direct tensile, flexural, and compressive bond strength). Seven different mixes were prepared according to the used glass granular ratio (three mixes contained white glass with 15, 20, and 25% while three of them contained green glass granular 5, 10, and 15%, and the last mix was a controlled mix which contains no glass gr
... Show MoreThe research explain The Effect of Domes Geometry Formation (size, shape,..) on Acoustic
Performance, that for importance of this element in designing aspect specially in Islamic architecture
and in the mosques building.
The research follow sound reflection diagrams to obtain graphic forms that explain the affection of
various Geometry Formation on Acoustic Performance , after analyze the graphic forms the final
conclusions are introduced to obtain a primary vision about a capability of dome and who deal with it.
Conformal projection is one of the most important aspects that geodesy dealing with. The
determination of the scale factors in the meridian, the parallel and projected geodesic directions are the
final result of the conformal projection. Methods for determining the scale factors in the meridian and
the parallel directions have a quite sufficient accuracy. While methods for determining the projected
geodesic have different accuracy and computation complicity.
This research adopts a modified method for computing the exact value of scale factor in
geodesic direction. In this method the scale factor is obtained by determining the true and projected
distances of the geodetic line. In the traditional methods for determinin
In this paper possible improvements in the performance of adaptive Linear Equalizer (LE) and Decision Feed Back Equalizer (DFE) are reported. A modified Least Mean Square (LMS) algorithm incorporating a recursively adjusted adaptation step size based on rough estimate of the performance surface gradient square is proposed. The first
proposed algorithm was called Adjusted Step Size LMS (ASSLMS) which used single adjusted step size for all weight coefficients. The second proposed algorithm was called Distributed Step Size LMS algorithm (DSSLMS). This algorithm (i.e. DSSLMS) will distribute the resultant variable step size in an exponential form among all weights of the
adaptive filter such that each weight coefficient has its own
In this paper an attempt to provide a single degree of freedom lumped model for fluid structure interaction (FSI) dynamical analysis will be presented. The model can be used to clarify some important concept in the FSI dynamics such as the added mass, added stiffness, added damping, wave coupling ,influence mass coefficient and critical fluid depth . The numerical results of the model show that the natural frequency decrease with the increasing of many parameters related to the structure and the fluid .It is found that the interaction phenomena can become weak or strong depending on the depth of the containing fluid .The damped and un damped free response are plotted in time domain and phase plane for different model parameters It is fou
... Show MoreNon uniform channelization is a crucial task in cognitive radio receivers for obtaining separate channels from the digitized wideband input signal at different intervals of time. The two main requirements in the channelizer are reconfigurability and low complexity. In this paper, a reconfigurable architecture based on a combination of Improved Coefficient Decimation Method (ICDM) and Coefficient Interpolation Method (CIM) is proposed. The proposed Hybrid Coefficient Decimation-Interpolation Method (HCDIM) based filter bank (FB) is able to realize the same number of channels realized using (ICDM) but with a maximum decimation factor divided by the interpolation factor (L), which leads to less deterioration in stop band at
... Show MoreAn experimental study was conducted on pressure drop of water flow through vertical cylindrical packed beds in turbulent region and the influence of the operating parameters on its behavior. The bed packing was made of spherical and non-spherical particles (spheres, Rasching rings and intalox saddle) with aspect ratio range 3.46 D/dp 8.486 obtaining bed porosities 0.396 0.84 and Reynolds number 1217 21758. The system is consisted of 5 cm inside diameter Perspex column, 50 cm long; distilled water was pumped through the bed with flow rate 875, 1000, 1125, 1250,1375 and 1500 l/h and inlet water temperature 20, 30, 40 and 50 ˚C. The packed bed system was monitored by using LabVIEW program, were the result
... Show MoreThe present work deals with an experimental investigation of the effect of surfacing parameters on the final quality of large gear surfacing. This gear forms a vital part of the drive train of cement furnace at the Iraqi Cement Company. The gear is made of DIN CK 45 steel with an analyzed carbon content of 0.429% and core hardness 185 HV. The gear is considered large, with dimensions of 490 mm in diameter, 250-mm width and 27 mm module, its weight is 350 Kg. The aim of the present work is to study the possibility of repairing this type of gear using SMAW process. The gear surface is cleaned by sand blasting, followed by dye penetrate testing for crack detections. DIN E1-UM350 hardfacing electrode is selected to hardface the gear. This el
... Show MoreThe effect of considering the third dimension in mass concrete members on its cracking
behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method.
The finite element method was also implemented in the structural analysis adopting the
concept of initial strain problem. Drying shrinkage volume changes were calculated using the
This paper is concerned with the investigation of the optimum period of time between maintenance by the aid of Monte Carlo simulation technique of an old water tube boiler, double identical drums; its capacity is 70 ton/ hour of super heated steam. There are a multitude of failures that are caused by boiler operator's errors, boiler inspector, boiler maintainer and faults of boiler auxiliary equipments which lead to operation parameter deviations and boiler shut down. Changing maintenance plan to be based on optimum period of time between scheduled maintenance and inspection will achieve maximum boiler availability.
his work presents the simulation of a Parallel Concatenation Convolution Coding PCCC with Multi-Carrier Code Division Multiple Access (MC-CDMA) system over multipath fading channels with a comparison with the uncoded data and that uses Serial Concatenated Convolutional Coding SCCC. The decoding technique used in the simulation was iterative decoding since it gives maximum efficiency with six iteration. Modulation schemes that used are Phase Shift Keying (BPSK, QPSK and 16 PSK), along with the Orthogonal Frequency Division Multiplexing (OFDM). The channel models used are as specified in the Third Generation Partnership Project (3GPP) Technical Specification TS 25.101 v2.10 with a channel bandwidth of 5 MHz.It was noticed that there is an
... Show MoreLaminar natural convection heat transfer to air flow in a ducted two parallel plates subjected to same constant heat flux has been studied experimentally. In this study a test rig has been designed and constructed to allow studying the effect of plate spacing and plates angle of inclination on the heat transfer process. The study covers three plate spacing 15 mm, 35mm and 60 mm that makes plate aspect ratio (AR) 24, 10.285 and 6, The heat flux implemented in all test runs varies between 55 W/m2– 340 W/m2 that makes the modified Rayleigh number (Ra) varies from 105-108. Experimental results presented as plate temperature distribution, variation of local heat transfer coefficient and the relation between Nu and Ra, reveal for the range o
... Show MoreThe undrained stability of cohesive slopes (0) subjected to surcharge loads is studied in this paper. Problems of this kind are involved in structures rapidly built near the crest of cohesive slopes and heavy equipment (e.g. draglines, buldozers and railways) move on slope. Using the non-linear finite element method, the effects of line loads and uniformly distributed loads are studied and the distribution of stresses under these loads is examined. The value of Per (critical line load) required equating the driving and resisting moments for a unit length of the slope was computed using the computer program. The process was repeated until a mininnum Per was obtained.
This paper presents the Taguchi approach for optimization of hardness for shape memory alloy (Cu-Al-Ni) . The influence of powder metallurgy parameters on hardness has been investigated. Taguchi technique and ANOVA were used for analysis. Nine experimental runs based on Taguchi’s L9 orthogonal array were performed (OA),for two parameters was study (Pressure and sintering temperature) for three different levels (300 ,500 and 700) MPa ,(700 ,800 and 900)oC respectively . Main effect, signal-to-noise (S/N) ratio was study, and analysis of variance (ANOVA) using to investigate the micro-hardness characteristics of the shape memory alloy .after application the result of study shown the hei
... Show MoreIn this work, the behavior of reinforced concrete columns under biaxial bending is studied. This work aims at studying the strengthening of columns by using carbon fiber reinforced polymer (CFRP). The experimental work includes investigation of eight reinforced concrete columns (150*150*500mm) tested under several load conditions. Variables considered in the test program include; effect of eccentricity and effect of longitudinal reinforcement (Ø12mm or Ø6mm). Test results are discussed based on load – lateral deflection behavior, load –longitudinal deflection behavior, ultimate load and failure modes. The CFRP reinforcement permits
a complete change in the failure mode of the columns .The effect of longitudinal reinforcement in
Increasing the aerodynamic efficiency and enhancing the supermaneuverability for the selected supersonic aircraft (F-16A) is presented. Aerodynamic characteristics, surface pressure distribution and maximum lift are are estimated for the baseline configuration for different Mach number and angles of attack in subsonic and supersonic potential flow, using a low order three- dimensional panel method supported with semi-empirical formulas of Datcom.
Estimation of the total nose-up and nose-down pitching moments about the center of gravity of the completed aircraft in subsonic region depending on the flight conditions and aircraft performance limitations. A modern program was implemented by suggesting a two dimensional thrust vectori
... Show MoreAn experimental study has been carried out to investigate the possible reduction of formation damage that is result from drilling muds. This was accomplished through making a bridging system with different barite additions 70, 140, 200, 280 lb/bbl to fresh water mud. This bridging system creates an effective sealing of impermeable filter cake, thereby inhibiting continual losses of small solids and mud filtrate into the formation.The study indicates that all the truds, which were used, have the ability to damage the petrophysical properties of formation, but some additives to mud reduce the damage in petrophysical properties. In addition, it is found that minimum permeability damage can be obtained when the particles of drilling mud are
... Show MoreSmart water flooding (low salinity water flooding) was mainly invested in a sandstone reservoir. The main reasons for using low salinity water flooding are; to improve oil recovery and to give a support for the reservoir pressure.
In this study, two core plugs of sandstone were used with different permeability from south of Iraq to explain the effect of water injection with different ions concentration on the oil recovery. Water types that have been used are formation water, seawater, modified low salinity water, and deionized water.
The effects of water salinity, the flow rate of water injected, and the permeability of core plugs have been studied in order to summarize the best conditions of low salinity
... Show MoreThis research examines the use of vibratory treatments to reduce residual stresses in small welded parts. In this experimental investigation, a post weld vibration treatment was applied to T- A106 steel pipe fitting specimens to study the effect of the treatment on the residual stress and the hardness of the material. The vibratory stress relief treatment was carried out at different vibration frequency. The results have demonstrated that post-weld vibratory stress relief of small size fittings is possible and residual stress may be relieved, and the treatment may be an alternative method for heat treatment especially when unchange in dimensions and material stability are required.
In this paper, an experimental study of the thermal performance for hybrid solar air conditioning system was carried out, to investigate system suitability for the hot climate in Iraq. The system consists of vapor compression unit combined with evacuated tube solar collector and liquid storage tank. A three-way valve was installed after the compressor to control the direction flow of the refrigerant, either to the storage tank or directly to the condenser. The performance parameters were collected by data logger to display and record in the computer by using LabVIEW software. The results show that the average coefficient of performance of hybrid solar air conditioning system (R=1) was about 2.42 to 2.77 and the average p
... Show MoreThe aim of this study was to investigate the effect of operating variables on, the percentage of removed sludge (PSR) obtained during re-refining of 15W-40 Al-Durra spent lubricant by solvent extraction-flocculation treatment method. Binary solvents were used such as, Heavy Naphtha (H.N.): MEK (N:MEK), H.N. : n-Butanol (N:n-But), and H.N. : Iso-Butanol (N:Iso:But). The studied variables were mixing speed (300-900, rpm), mixing time (15-60, min), and operating temperature (2540, oC). This study showed that the studied operating variables have effects where, increasing the mixing time up to 45 min for H.N.: MEK, H.N.: n-Butanol and 30 min for H.N.: Iso-Butanol increased the PSR, after that percentage was decreased; increasing t
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