Journal of University of Babylon

The main aim of this paper is to investigate the linear elastic behavior of non-prismatic beam ‎on Winkler foundation. The finite differences method was used to solve the governing differential ‎equations for different configurations of non-prismatic cross-section and loading cases with different ‎end supports. The results from these different cases are plotted together and check the accuracy of the ‎solutions, which referred to the good efficiency of this analysis. The results indicated that present non-‎prismatic beam decreasing in deflection for longitudinal direction (width of beam b) and transverse ‎direction (depth of beam h) about (80.67-81.81%)and(75.99-81.81% ) , respectively for different cases ‎of loading. The results indicated that the value of Bending Moment is increasing for different cases of ‎loading for non-prismatic beam compared with prismatic beam about (68.53-96.5%), while ‎decreasing in Shear force due to point load at mid span about (51.64%).‎

This research is devoted to investigate the behavior of reinforced concrete beams loaded and exposed to ‎fire flame. In this study, some mechanical properties and deflection behavior of rectangular reinforced ‎concrete beam specimens under the effect of burning is presented. The concrete specimens and beams ‎were subjected to fire flame temperatures ranging from (25-800 °C) at different ages of 28, 60 and 90 ‎days, three temperature levels of 400, 600 and 800 °C where chosen for exposure duration of 1.0 and 2.0 ‎hours.‎
‎ Load-deflection curves indicate changing response with the fire exposure. Also, it was found that the ‎shrinkage values increase with temperature increase.‎
‎ Results indicate remarkable reduction in flexural strength after exposure to fire flame. The residual ‎flexural strength is (88 and 81%) with 1.0 and 2.0 hour exposure periods respectively at fire temperature ‎‎(400ºC), while the residual at fire temperature (600ºC) is (66 and 53%) with 1.0 and 2.0 hour exposure ‎periods respectively, while the residual at fire temperature (800ºC) is (45 and 36%) with 1.0 and 2.0 hour ‎exposure periods respectively. ‎
‎ It is found that the ACI 318/ 2008-Code equations are safe to predict bending moment capacity for ‎fire temperature (400ºC), while at burning (600ºC) gave overestimated results to predict moment capacity, ‎but become unable to predict moment capacity at fire temperature (800ºC).‎

M array space time block code (STBC) system can provide high data rate wireless services in ‎a rich scattering environment multi input multi output (MIMO) channel but increasing modulation ‎order (M) degrades the bit error rate (BER) performance of the system. The aim of this work is to ‎improve the BER performance of 64PSK STBC using turbo product code .This paper gives an ‎introduction to the basic concepts of MIMO channel and explains the implementation of the 4 ‎transmitters STBC encoder/ decoder. The two main parts used in STBC decoder, channel estimator ‎and maximum ratio combiner, were illustrated. Channel estimator was build using orthogonal pilot ‎training sequence. Finally product block code and its iterative decoding using soft in soft out ‎maximum likelihood decoder were illustrated.‎
Computer simulation for four different space time block codes schemes including rate 1, 0.75 ‎STBC's as well as two rate 0.5 STBC's with two different code dimensions are explored. These STBC's ‎techniques are implemented in MATLAB2010 and analyzed for BER performance according to their ‎modulation order (M=4, 16 and 64PSK) and number of receiver antennas (Nr=1, 2, 4 and 8). Finally, ‎‎(8,4) exHamming turbo product code was combined with 64PSK 4×2 STBC's system and evaluate the ‎new BER performance in MIMO Rayleigh fading channel.‎
الخلاصة

This research is devoted to study the effects of strengthening the bottom flange of steel I-section ‎simply supported horizontally curved beams on the behavior and maximum strength of these beams ‎under concentrated static load. The strengthening includes increasing the thickness of bottom flange at ‎finite region (angle of strengthening,(φ)), thus the volume of steel will be increased. Three dimensional ‎nonlinear finite element analyses done utilizing computer program called NFHCBSL, incorporate 20-‎node isoparametric brick element used to represent the steel elements. The study incorporates five ‎angles of horizontal curvature (0=5o,10o,15o,30o and 45o). For each angle of horizontal ‎curvature ‎, eight regions of strengthening investigated, thus forty case had been studied. The results ‎show that by strengthening the bottom flange of this type of beams the ultimate strength of beam can ‎be increased about 35%, while the maximum vertical and the horizontal deflections can be reduced by ‎‎67% and 69% respectively, when the angle of strengthening (φ =‎ ‎,i.e. the increment in the ‎volume of steel is equal to 15.7%). Also, when the angle of horizontal curvature(‎ ‎) increases the ‎ultimate strength of beam decreases for any value of angle of strengthening (φ), but this decrement ‎increase rapidly if the angle of strengthening (φ) was increased.‎

The experimental results of flow pattern and pressure drop of gas–liquid flow in inclined pipe ‎are presented. The diameter of test section is 50 mm, and overall length of 4 m. The inclination angle ‎of the test section is 30o. Air and water are used as working fluids. The gas superficial velocity and ‎liquid superficial velocity are varied in a range of (1.358142-5.432568) m/s and (0.169764-1.527884) ‎m/s, respectively. The pressure drop along the test section of the pipe is also measured. The ‎characterization of flow patterns is achieved via visual observations and by analysis of local pressure ‎measurements. The observed flow patterns are presented in terms of flow pattern maps for pipe ‎inclination. The slug two-phase flow patterns are observed in the experiments. A video camera ‎recording and pressure transducer sensor with interface are used to study flow regimes and pressure ‎drop through test section. The following flow regimes, depending on the superficial liquid and gas ‎velocities are observed. The flow regime and pressure fluctuating across pipe depending on superficial ‎liquid and gas velocities. It noted that the pressure decreases with distance along pipe when gas ‎superficial velocity increased and also increased liquid superficial velocity.‎

Two aspects of environmental pollution have been dealt within the study which include air ‎and noise pollution of electrical generators: In the air pollution, difference in contaminant ‎concentrations between those caused by diesel and gasoline generator have been noticed when the ‎contaminant concentrations(Soot, Pb, SO2, NO, CO) increasing from gasoline generators more than ‎diesel generators and more than the proposed national specified in some cases. The diesel generators ‎‎(10%) resulting of carbon monoxide from gasoline generators. Gasoline generators have more than ‎the national specified (35 ppm) . The lead concentrations are lacking in diesel but the amount of lead ‎increased to more than the proposed national specified (1.5μg/m3) in the case of the use of gasoline ‎generator. The contaminant concentrations SO2 output of gasoline generators are very few compared ‎with the contaminant concentrations SO2 output of diesel generators and higher than the national ‎specified (0.1 ppm) in the case of diesel generators. The contaminant concentrations of NO from ‎gasoline generator is slightly larger than the contaminant concentrations of NO output from diesel ‎generators. The amount concentrations of particulate matter group generating by gasoline less than ‎the diesel generating , the main problem of diesel engines are odor and smoke. Either noise pollution, ‎the sound pressure level decreasing from (6-7 dBA) at doubling the distance between the source and ‎the listener have been noticed , this means that the sound pressure level that is appropriate for ‎Ugartmia and relatively less rate (6-7 dBA) at doubling the distance at the source approximately and ‎compared with parameters WHO environmental noise (50-55 dBA) (period was 16 hours) and (EPA) ‎‎(80 dBA) for Iraq residential areas, was developing the required distances.‎

This includes research Empirical study replace poly vinyl acetate (P.V.A) as a binder material ‎used in emulsion paints textured sodium silicate being manufactured locally and cheaply priced ‎compared textured the P.V.A imported from abroad and prices are expensive. As it has been business ‎model without binder material consists of water (solvent), additives, fillers and pigments was the work ‎of three models of it for research purposes, ensure that the model (1) add P.V.A the proportions of ‎‎10%, 20%, 30% of the weight of the original model, while the form (2) added sodium silicate in the ‎proportions 10%, 20%, 30% of the weight, while model (3) mixing model (1) with model (2) ratio of ‎‎1:1. Conducted laboratory tests conforming to the standard Iraqi No. 985 special with emulsion paints. ‎The results of the research the possibility of using Article alternative surfaces of internal and external ‎cement and blocks and steel sheets with high efficiency and resistance to rain monsoon and high ‎stability of the climatic conditions changing grades temperature and humidity, and others. also ‎demonstrated the possibility of using this paint against fire.‎

The main problems of the institutes concerning with the highways in Iraq, that almost ‎highways network are old and have along years in services without taking in view of points the ‎explosion extension that happen after 2003 in level of numbers, weight, types of vehicles that use the ‎roads and un-normal environments subjected to it the highway structures, as well as the other sides of ‎live in general. Therefor it is a huge important to work hard in maintenance affectations for these great ‎projects in order to elongated their design lives.‎
The current research represent first step to definition the beast ways that can be depended in overlay ‎design, where, in Iraq, the Asphalt Institute Manual (MS-17) depend in overlay design while the ‎American Association of State Highway and Transportation Officials, (AASHTO) depended in ‎pavement design, which have an effect on the performance of the pavements that have a great effect ‎on the services presented by the highway. Four highway segments in the middle district in Iraq, were ‎chosen as a case study for overlay design depending on both procedures of design with comparison. ‎

The research aims to indicate the effect of the using multiple types of super plasticizer on the ‎properties of self – compacting concrete .(29) mix concrete were made , one reference and the (28) ‎mixes self – compacting concrete . the ratio of mixing is (1 :1.95 :2.37) and water to cement ratio is ‎‎(0.60) for the reference mix and (0.50) for the rest of the concrete mixes of self – compacting concrete ‎‎, the percentage of super plasticizer used was the proportion (0.5 , 1.0 ,1.5 ,2.0)% of cement weight ‎‎.The value of slamp of reference mix is (63)mm and the values of slamp of (scc.) ranging between ‎‎(510 – 780)mm , time of t50 cm ‎‏ ‏between (2 – 5) second, time v – funnel test ranged between (6 – 12) ‎second and the percentage of H2/H1 to L – Box test where (0.82 – 0.85) . The values of compressive ‎strength oh cubes of concrete ranging between (6.8 to 5.30)N/mm2 for the mixture of reference for the ‎ages (3 – 90) days , the values of compressive strength of mixtures of self – compacting concrete range ‎from (18.2 – 28.4) , (18.5 – 44.8) , (27.8 – 61.0) and (41.2 – 65.3) N/mm2 for the age (3 , 7 , 28 , 90) ‎days , respectively . ‎

‎ In this work had been determine the Townsend's energy factor KT and the electron drift velocity in ‎terms of electron mean free path L in unit of pressure, the energy loss factor G and the applied electric ‎field to the gas pressure ratio at 300 oK in air. The obtain transport coefficients by solved numerically ‎transport equation solution and had be fed to the derived equations.‎
‎ The obtained results had be graphically draw as a function for its variables, which appeared a good ‎agreement with published experimental data.‎

Sulphate attack is a significant problem which locally affects concrete and other constructional ‎materials. The aim of this research is to find the influence of Internal Sulphate Attack (ISA) on some ‎mechanical properties of SCC (Ali E. M., 2006). The mechanical properties studied are compressive ‎strength, splitting tensile strength and flexural strength at 28- days and 60- days respectively.‎
‎ In this study, three levels of sulphates are added to the sand to investigate the influence of sulphates ‎on SCC made from locally available materials and compared it with reference normal mix.‎
‎ Based on the results of this study, it concluded that when the amount of SO3 increased by (0.5-1.5) ‎‎% by weight of sand, the (compressive strength, splitting tensile strength and modulus of rupture) ‎decreases by (10-26) %, (9-29) % and (14-35) % at 28-days respectively, while they decreases by (12-‎‎51) %, (17-30) % and (23-43) % at 60-days respectively.‎

The research aims to investigate the effect of adding chloride salts including (NaCl, MgCl2, ‎and CaCl2) on the engineering properties of silty clay soil. Three amount percentage of salt (2%, 4%, ‎and 8%) were added to the soil to study the effect of salts on the compaction characteristics, atterberg ‎limits, and unconfined compressive strength. ‎
The results showed that the increase in the percentage of each of the chloride salts increased ‎the maximum dry density and decreased the optimum water content. The liquid limit, plastic limit, and ‎plasticity index decreased with increasing salt content. Also the results showed that the unconfined ‎compressive strength increased when the salt content increased too.‎

The weir applications in the measurement of discharge large and small channels are open in the field or ‎the laboratory, and in general can be defined weir as a handicap regularly happen flow from it. More weirs ‎widespread and commonly used is the weirs sharp with a notch of rectangular and triangular, which is ‎often where the coefficient of discharge cd starts from 0.55 for the rectangular notch and 0.59 for the ‎triangular notch, but these transactions are affected by viscosity and surface tension, roughness of the ‎plate and weir.‎
In this research was the work of models with semi-circular notch, meaning it took half a circular notch ‎in three different models diameters (6cm, 8cm, 10cm) and operated with hydraulic bench in the ‎laboratory, all models in the same conditions in terms of temperature and for several times and is intended ‎here all models are models of the notch-sections (semi-circular, v-notch and rectangular).‎‏ ‏The values of ‎discharge coefficient (cd) of the rectangular notch between (0.73- 0.71) while the discharge coefficient (cd) ‎of the V- notch between (0.85- 0.78), while the discharge coefficient (cd) for the half-circular notch ‎between are such that no (0.93- 0.88). To find out the best form of notch weir took the coefficient of ‎discharge (cd) function on it. From above can be inferred that the weirs with a half-circular notch is the ‎best in terms of hydraulic discharge measurement in rectangular notch weirs with and v-notch.‎

Power and power quality are of most importance in modern energy systems. The analysis of ‎electrical power measurement is an important consideration to electrical utilities and industrial ‎customers so that diagnosis and mitigation of such disturbances can be implemented quickly. This ‎paper presents the development of a computer based data acquisition system that provides practical ‎measurement of power components (apparent, active, and reactive) under sinusoidal, non sinusoidal, ‎stationary and non stationary conditions by using continuous wavelet transform. Wavelet transform ‎measuring technique is the more accurate as it has a position analytic ability (analytic of a specified ‎position from the signal of non sinusoidal waveforms). This method is fast, efficient and overcomes ‎limitations of the current techniques. The practical results of the mentioned technique have been ‎compared with the practical results obtained using AC/DC clamp power meter device.‎

Water quality index (WQI) is a mathematical tool used to transform large quantities of water ‎quality data into single number which represents water quality level. This research is accomplished to ‎evaluate the quality of groundwater in Dibdiba aquifer/Kerbala city-Iraq for the purpose of drinking ‎by using Water Quality Index (WQI). Groundwater samples were collected in April, 2010 from 20 wells. ‎Various physicochemical parameters: pH, total dissolved solids, potassium, bicarbonate, sulphate, ‎total hardness, sodium, calcium, magnesium, and chloride have been calculated in all the water ‎samples. In most of the parameters the concentration observed were found to be above the ‎permissible limits of the Iraqi standard for drinking purpose. The results showed that WQI values for ‎the groundwater of the study area ranged from 432.6 to 184.5, which mean water was found to be ‎severely contaminated and unsuitable for drinking purpose at all sites of the wells. Also this research ‎concluded that further improvement is required to treat the water of Dibdiba aquifer wells for using as ‎drinking purpose.‎

This research presents an experimental program conducted to study the flexural behavior of ‎reinforced concrete continuous beams strengthened by carbon fiber reinforced polymer (CFRP) sheets. ‎The test program consists of nine RC continuous (two-span) beams each span has length 1500mm ‎with cross section 150x250 mm divided into two groups. The first group has six continuous RC beams ‎with roller support in the ends. The second group has three continuous RC beams with rigid joint ends ‎supports ( jointed to columns in the ends ). All the reinforced concrete beam specimens were designed ‎of the same steel reinforced identically to fail in flexure under static load .The main parameters ‎including type of end support, location of the CFRP sheets and type of end anchorage for CFRP. The ‎experimental results showed that the externally strengthened reinforced concrete beams with bonded ‎CFRP sheets showed significant increases in their ultimate loads. An increase in ultimate load reached ‎up to (42.1 % for group 1 and 35.18 % for group 2). The CFRP anchor is very effective more than the ‎U-warp in increasing ultimate load and reduced beams deflection. ‎
Three-dimensional nonlinear finite element analysis is used to investigate the performance of ‎reinforced concrete continuous beams strengthened with CFRP sheets. The results obtained from the ‎finite element analysis show very good agreement with the results obtained from the experimental ‎study with maximum difference in ultimate loads is about (10 %).‎

‎ Increasing the flow of parts under manufacturing‏ ‏in production and assembly lines one of the ‎most important goals that administration is seeking to achieve them. Problems of balancing the production ‎and assembly line created to uneven distribution of workloads on workstations along the production and ‎assembly line, Which is usually measured in number of units produced in the unit of time (hours / day), ‎and can be irregular flow of production and raised the achievement of balanced production line. research ‎aims to study the problem of balancing single production lines and the most important methods adopted ‎to solve it and try to apply that in the production line was chosen as the assembly line cookers in light ‎Industrial Company and calculate the material flow or parts in the production line, where the parts ‎moving between work stations by conveyor system‏ ‏‎ ‎‏ , ‏Software‏) ‏Quantitative Methods‏ ‏‎,Production and ‎Operations Management POM-QM) has been used ‎‏ ‏‎ to solve the problem of balancing single production ‎lines to calculate the‏ ‏actual number of workstations are (9) workstations and production flow (35) units / ‎day, the efficiency of the line (% 78.24) By choosing the shortest task time method to increase the ‎production flow to (37) units / day to increase efficiency (81.64%‎‏(‏‎.‎

A first order of DWA (data weighted averaging) technique is proposed to improve 6-bit ‎digital-to-analog convertor (DAC). In addition, this paper discusses the impact of mismatch between ‎DAC unit elements. The simulation results show the effectiveness of the DWA technique in reduction ‎of inband tones, also DWA technique proves its ability to solve DAC unit elements mismatch. The ‎element mismatch noise is converted into a broadband. The mismatch elements noise‏ ‏is improved 9 ‎dB if ‎ ‎=0.01 with proposed DWA, thus improving the DAC performance if compared with DAC ‎performance without using DWA circuit. ‎
Keywords: Digital/Analog Converter (D/C), DAC mismatch, Dynamic Element Matching (DEM), Data ‎Weighted Averaging (DWA) technique.‎

The use of White Crushed Gravelfrom Kerbela Quarries in the design of high strength concrete ‎mixes is evaluated through this research. Two grades of mixes are undertaken; they are A (40 Mpa) ‎and B (60 Mpa)of compressive strength. The mixes proportion is used for the design in these mixes are ‎‎(0.35 and 0.3 water/cement ratio), (446kg/m3 and 550kg/m3 cement), (0.8 liter/kg super plasticizer‏(‏‎ for ‎each A and B mixes respectively. ‎
The fresh concrete tests results indicate that mixes made of the Crushed White Gravel ‎characterized with slump value of 57 and 52 mm and compaction factor of (0.95, 0.92) for the mixes ‎type A and B respectively.‎
The maximum compressive strength of (43.6and 62.2)Mpa,the modulus of elasticity of (40.5 and ‎‎43.4) Gpa, the modulus of rupture of (6.3 and 6.7)Mpa, the splitting tensile strength of (4.5 and 4.9 ‎Mpa, the Ultra Sonic Pulsevelocity of (4.25 and 4.58)Km/sfor both A and B mixes respectively at 28 ‎days.‎

This paper includes experimental investigation to study the effects of air and water discharge for ‎different angle of attacks for straight hydrofoil and built an experimental rig to study the two phase flow.‎
‎ In this work three different angle of attack (θ = 0°, 15° and 30°) are considered .The water discharge ‎‎(Qw) at different quantities (Qw=12, 17, 27 and 37 L/min) and different air discharge (Qa=5, 15, 25 and 35 ‎L/min) were taken. The maximum inlet velocity at the test section for air is (4.758 m/s) and for water is ‎‎(1.217 m/s).‎
‎ The results show that when the angle of attack increase at constant amount of air and water discharge ‎the pressure difference increased at inlet and outlet the rectangular channels. The results explain that when ‎both water and air discharge at constant angle of attack the pressure difference increased at inlet and ‎outlet the rectangular channels.‎

This research presents an explicit finite difference solution for the one-dimensional ‎consolidation of a homogeneous clay layer with permeable top and impermeable bottom. A computer ‎program was written in BASIC to deal with this problem. The comparison of the numerical solution ‎developed with the corresponding solution by Craig (2007) for the case of non-uniform initial excess ‎pore-water pressure distribution showed excellent agreement. The computer program was written so as ‎to deal with one dimensional consolidation of one layer clay for whatever case need to be studied. ‎Different hydraulic boundary conditions, different distributions of initial access pore water pressure, ‎and different properties of soil can be easily studied using this program. The researchers and students ‎will not find any difficulty to find the degree of consolidation of any type of soil layer especially when ‎they run the computer program which will take the pore water pressure for all meshes and time needed ‎very fast by using finite difference technique.‎

Box-Jenkins seasonal model is applied in this study to records of mean flow to Haditha ‎reservoir in the middle west of Iraq for period from water year 1999/2000 to water year 2008/2009 . ‎Two types of model (0,1,1) × (0,1,1)12 and (0,1,2) × (0,1,1)12 are suggested, and the selected model is the ‎one which give minimum sum of squares (SS). The unconditional sum of squares is used to estimate ‎the model parameters. It is found that the model which corresponds to the minimum sum of squared ‎errors is the (0,1,2) × (0,1,1)12 model with parameters θ1 =0.368 , θ2 =0.321 and Θ =0.910. Port Manteau ‎Lack of fit test and Residual Autocorrelation Function (RACF) test are applied as diagnostic checking. ‎Forecasts of monthly inflow for the period from October ,2009, to September,2011, are compared ‎with observed inflow for the same period and since agreement is very good adequacy of the selected ‎model is confirmed.‎

‎ Radar surveys aim to find information about the underground bodies and structures. Some of the ‎radar wave energy leaks out above the surface due to unwanted reflections caused by surrounding ‎features at the survey area like buildings, columns, automobiles, trees, …etc. These unwanted ‎reflections mask the radargram and mislead the analyst in the interpretation phase. In this research ‎two types of air reflections were studied for both types of the GPR antennas, the shielded antenna and ‎the unshielded antenna in order to distinguish between real GPR data from false data caused by air ‎reflections.‎

Three phase supply system is found to be quite balanced in both magnitude and ‎displacement at the generation levels but it is not so at distribution end. Voltage unbalance which is a ‎common and global phenomenon is found to be very effective in deteriorating the operation and ‎performance of electrical apparatus. Present paper is an attempt to analyze the operation of three ‎phase distribution transformers with unbalance voltage conditions. MATLAB programming based ‎upon symmetrical component approach is adopted to estimate the performance of a three-phase ‎transformer under unbalanced condition. Both under voltage unbalance as well as over voltage ‎unbalance have been considered for analysis purpose. Numerical details study in case of distribution ‎transformer with primary delta connection and secondary star connection with solidly grounded ‎neutral‏ ‏is presented in this paper. The degree of voltage unbalance is represented by the voltage ‎unbalance factor (VUF) derived from symmetrical component. ‎