Journal of University of Babylon

In the present work the aerodynamic characteristics of a bus was studied. Flow analyses was ‎carried out assuming two dimensional, steady incompressible and viscous. The effect of speed and ‎yaw angle variation were investigated separately. Experimental and theoretical investigations were ‎carried out. A bus model of 1:20 scale ratio was used for experimental testes. A wooden bus model ‎was made with smooth surfaces to simulate the prototype.‎
‎ The tests were carried out in a low speed wind tunnel, the air speed was varied from 14.5 m/s ‎to 24.5 m/s and yaw angle from 0o to 15.‎
A package program (Ansys 5.4) was used to carry out the theoretical study. This gave a good ‎ability to calculate the pressure and velocity distribution and sketching the eddies in the near wake ‎behind the bus model. It was found that increasing the yaw angle increases the drag and pressure ‎coefficients .At air speed equals to 14.5 m/s the difference in the pressure coefficient in the flow ‎direction CP(front-rear) varies from 0.05 at Q=0o to -0.055 at Q=10o, .For the same condition the drag ‎coefficient varies from 0.72 to 0.76.‎
The comparison made between the experimental results, and some experimental published ‎data showed a good agreement. The results obtained by Ansys 5.4 program for the specific ‎configureuration were compared with the present experimental work and they showed a reasonable ‎agreement .‎

The satisfactory performance of porous media as insulation in industrial applications depends upon the ‎thermal properties of both the fluid and solid phases. Simulation of macroscopic of the onset of transient ‎convection in porous media was proposed for a semi-infinite saturated porous media (glass-water) with ‎heating from below as a boundary condition.‎
Effective thermal properties have been affected directly in the calculation of macroscopic ‎model of heat transfer rate. Through this model was simulated the onset natural convection by ‎calculated the transient convection of heat transfer coefficient between the top surface layer of solid ‎phase and the bulk temperature of fluid phase by two values of heat flux at different void space of fluid ‎layer. Also, Nusselt number and Rayleigh number of porous media were calculated at different interval ‎times of heating.‎

‎ ‎ Laminar mixed convection flow in equilateral triangular lid-driven enclosure is numerically ‎investigated by using ANSYS 12.1 program .The horizontal side wall is sliding from left to right with a hot ‎temperature of (Th). The other two inclined walls are considered to be isothermal, cold and its ‎temperature is (Tc). The governing equations (energy equation, momentum equation and continuity ‎equation) are solved using the finite element method with ANSYS 12.1 program. The governing ‎parameters are Grashof number (Gr =105,106 and 107) and Richardson number (Ri=0, 1, 10, 100). An air ‎is used as a working fluid with Pr=0.71. The obtained results represent as isothermal contours and stream ‎function. It is obvious from the result that, the motion of the sliding wall has a dramatic effect on the ‎flow and temperature distribution more than the buoyancy force, and then has an effect on heat ‎transfer.‎

The extraction behavior of (Cd (II), Cu (II), Fe (II), and Zn (II)) metal ions was studied in an ‎aqueous biphasic system formed from poly ethylene glycol and sodium Sulphate in the presence of ‎iodide (KI) and thiocyanate (KSCN) as extractants. The extraction percentage was determined at ‎constant temperature of 25oC, PH of 2.5 and mixing time of 10 min. and as a function of the ‎following variables:‎
• Concentration of (KI) or (KSCN) solvents between (0.1-0.7) ml of 2 g/l solution.‎
• Volumetric phase ratio of PEG to Na2SO4 in the range of (0.5-3).‎
• Initial concentrations of the metal ions between (0.5-0.15) ml of 1 g/l metal solution added.‎
The extraction percentage (%) of metals is mainly increased with the increasing of each concentration ‎of the extractant, phase ratio, and the initial concentrations of the metal ions. The extraction ‎percentage of (Cu (II), Fe (II), and Zn (II)) was higher for the system containing (SCN-) than (I-), while ‎the extraction (%) of Cd (II) was higher in the system containing (I-) than (SCN-). The mixtures consist ‎of (0.5) ml of initial concentration of metal ions, (0.7) ml of (KSCN), (3) of (PEG/Na2SO4) volumetric ‎phase ratio had the best results of the extraction of (Cd, Cu, Fe, and Zn) which equal to (87, 92, 92, ‎and 80) % respectively.‎

‎ This investigation is conducted to study the effect of adding of the milted clay brick powder(MCBP) with ‎the admixture silica fume (SF) on the properties of clay brick. All specimens of bricks were made from ‎al_furat factory soil . three levels of addition were used for (MCBP) ,(2%,4%,and8%by weight of dry soil)and ‎three levels of addition were used for (silica fume),(3%,6% and 9% by weight of dry soil). All specimens were ‎mixed ,molding and placing by hands with special mold. The experimental results showed that the ‎increasing of addition (MCBP) without silica fume increases of compressive strength about (5%,11%and15 ‎‎%) and decreases water absorption about (4%,5% and13 %) and decreases efflorescence about (5%,11% ‎and20%) when three levels of addition were used for (MCBP) ,(2%,4%,and8%by weight of dry soil) ‎respectively in clay brick, but the silica fume addition causes decreases in compressive strength and ‎increases in the absorption of water and efflorescence phenomena in clay brick. ‎

‎ Nonlinear analysis of reinforced concrete Bridge Deck Panels strengthened by carbon fiber reinforcement ‎sheets has been investigated in this paper. The ANSYS 12.1 computer program was used for this purpose. The finite ‎element models are developed using a smeared crack approach for concrete , three dimensional solid ‎elements(solid 65) for concrete, One dimensional solid elements(Link8) for steel reinforced bars , and three ‎dimensional layered elements(solid 46) for carbon fiber sheets (CFS). Three-dimensional finite element analysis was ‎conducted to obtain the response of the strengthened Bridge Deck Panels with CFS in terms of applied load –‎deflection. Comparison with previous experimental studies shows about 90% agreements.‎

The effects of some influencing parameters including steel reinforcement ratio and carbon fiber sheets thickness on ‎the behavior of strengthened Bridge Deck Panel were studied. The main conclusion was the steel reinforcement ratio ‎is main factor affecting the structural strength.‎

In this study the nonlinear finite element method used to analysis full-scale reinforced concrete slab with ‎opening strengthening with overlay concrete or CFRP sheets. The FE model proposal in this study are simulate ‎by using results of experimental work from previous study. The strengthening models proposal in this study by ‎using overlay concrete increase load carrying capacity of slab by amount vary from (5 to 30) % of slab strength, ‎when strengthening by using CFRP sheet increase load carrying capacity from (10 to 65)% of slab strength. ‎

‎ This research deals with the effects of using rice husk ash (RHA) as a partial weight of cement ‎replacement materials in cement mortar mixes. This work is based on an experimental study of mortar ‎made with ordinary Portland cement (OPC) and 5%, 10%, 15% and 20% (OPC) replaced by RHA. The ‎rice husk ash used was produced by burning the rice husk at 500˚ C, then grinding it to a fineness of ‎‎11200 cm2/gm (Blaine). The tests which were performed evaluate the action of this material were: ‎normal consistency, setting time, compressive strength, flexural strength and porosity. The results show ‎that addition of RHA show better results for 15% replacement level than OPC at 90 days.‎

‎ In this paper we consider the quarter car active suspension system suffering from unknown time-‎delay and external road disturbances . We derived a control law for achieving stability of the system and ‎convergence that can considerably improved the ride comfort and road disturbance handling. This is ‎accomplished by using Routh-Herwitz criterion and based on some assumptions. A mathematical proof ‎is given to show the ability of the designed controller to ensure stability and convergence of the active ‎suspension system and dispersion fast oscillation of system despite unknown time-delay and road ‎disturbances . Simulations were also performed for controlling quarter car suspension, where the results ‎obtained from these simulations verify the efficiency of the proposed design to faster suppression ‎oscillation and obtain stability although present of unknown time-delay and road disturbance.‎

‎ In the present work, the effects of machining parameters on surface roughness during high-speed ‎drilling of carbon fiber reinforced plastic (CFRP) composite are presented. The machining experiments ‎are carried out on lathe using two levels of factors. The factors considered were: % volume fraction of ‎carbon fiber, cutting speed, drill diameter and feed rate. A procedure has been developed to assess and ‎optimize the chosen factors to attain minimum surface roughness by incorporating: (i) response table ‎and effect graph, (ii) normal probability plot (iii) analysis of variance (ANOVA) technique. From the test ‎results, we observe that the technique used is convenient to predict the main effects and interaction ‎effects of different influential combinations of machining parameters. Feed rate is the factor, which has ‎greater influence on surface roughness followed by % volume fraction of fiber and drill diameter. The ‎interaction between all parameters has more influence on surface roughness, followed by (drill diameter ‎and feed rate) and (% volume fraction of fiber and drill diameter) comparing with other interactions on ‎the machining of CFRPS composites.‎

In this study, a numerical simulation using a finite element scheme is carried out for a laminar ‎steady mixed convection problem in a two – dimensional square cavity of length (L), containing ‎eccentric adiabatic circular body of radius (r=0.2 L). The vertical walls of the cavity are differentially ‎heated where the right wall is subjected to an isothermal temperature higher than that the opposite left ‎lid. Both the top and the bottom wall of the cavity are adiabatic. Four different cases have been studied ‎based on the location of the circular body. Cases I, II, III and IV refer to the circular is located near the ‎top, right, bottom and left walls of the cavity respectively. Results are presented for upward (+y) and ‎downward (-y) directions of the left lid in vertical axis and for different values of Richardson numbers ‎‎(Ri=0.1, 1 and 10). The cavity under study is filled with air with Prandtle number is taken as 0.71. Fluid ‎flow and thermal fields and the local Nusselt number are presented for all four case studies. The results ‎shows that the behavior of temperature contours, streamlines and velocity profile is sensitive to the ‎location of the circular body and to the direction of lid and this results explain also, that the maximum ‎values of local Nusselt number occurs when the left lid moving downward (-y) refers to higher heat ‎transfer. ‎

‎ The paper reports an experimental study investigating the influence of curing conditions on the ‎engineering properties of fiber reinforced concrete (FRC) . Portland cement (PC) concrete and two types ‎of FRC , i.e. SFRC with 1% by volume steel fiber reinforcement and PFRC with 1% by volume poly ‎propolylene reinforcement specimens are prepared and cured in two different curing conditions , ‎namely water and air conditions for the periods of 3,7,14 and 28 days . At the end of each curing ‎periods , compressive and tensile strength and ultrasonic velocity (UPV) values are determined . The ‎results showed that water curd specimens always give the highest values then air condition irrespective ‎of type and age of concrete and test method for both compressive and tensile strength tests , the PFRC ‎gives the highest values followed SFRC and then PC concrete for all curing periods and conditions , also ‎‎, the UPV results showed that the highest values are obtained from the PFRC and then from the SFRC ‎and PC concrete for all curing conditions .‎

A rehabilitation center of 2 floors, 35 spaces and 300 persons was used to check the merit of available ‎methods, which may be used to calculate the supply air volume flow rates for air conditioning systems. The ‎available methods were five, which are: - the method depending on sensible or latent space load, the method ‎depending on effective room sensible heat load, the method which depends on specifying certain air flow rate ‎for each calculated ton of refrigeration, the method which depends on number of air change through the space, ‎and finally the method depending on knowledge of contaminants concentrations and generation within the ‎space. The merit of each method was checked by determining the energy consumption, HVAC equipments size, ‎noise level and the influence of occupation density on body odour intensity for all building spaces of ground ‎floor. The efficiency of each method to calculate the ducting system design was calculated by determining a ‎factor (which was used for the first time in this research) called Duct Volume Ratio (DVR). The study shows ‎that the distribution of ducts system volume to the volumes of coffee shop and small kitchen secondary ceiling ‎for methods 1, 2 and 3 is very good ( about 0.07) since the values of DVR are acceptable.‎
The study of the present work revealed that the first three methods are converging in their calculated ‎supply air volume rates results and the fourth method is slightly different but the last one is very different so ‎that it should not be depended to calculate space load. The more precise one of these methods is the second in ‎spite of its tedious calculations because it is comprehensive for all the effective variables, which affect the ‎building HVAC design. The third method is the simplest and fastest method with reliable results. In addition, the ‎method four was so effective in required mechanical ventilation volumes calculations. The method five is ‎appropriate for knowing the minimum airflow rates, which are required to maintain specified rate of allowable ‎contaminant concentration within the space and in the supplied incoming conditioned air. ‎

A monopanel is the system building witch consists of two thin ferrocement block as a faces and ‎between them a bushy layer of low strength, density and cost as a core made from lightweight material for ‎example from polystyrene foam as using in this investigation or any material as an insulation .‎
The simple structural idealization of a monopanel system is that the core provides transverse ‎trusses between the faces that prevent flexural ,shear force and compression. Transverse trusses made of ‎steel bars having a diameter of 3.2 mm, which make available as tie reinforcement to prevent the thin ‎ferrocement skins from local buckling and compression, have been used in the present work. These ‎transverse system consist of two longitudinal bars connected by inclined steel bar forming trusses shape ‎making an angle equals to 60o with the longitudinal bars having same diameter.‎
The main object of this research is to present an experimental investigation on the behavior and ‎load carrying capacity of monopanel beams. The experimental work includes testing six groups of ‎monopanel beams, and has been investigated the effect of a different depths of monopanel beams and ‎number of layer of wire mesh of skin faces‏ ‏‎(one or two layers ) on the behavior and the ultimate load ‎capacity. Also comparison of these results with the ACI code 318M-08 formulations have been made.‎

The aim of the present work is study the corrosion behavior of low carbon steel in aqueous ‎diammonium phosphate (DAP) fertilizer solution with and without inhibitors’ addition in different ‎concentrations (5% & 35%) in different temperatures (25, 35, and 50 °C) by using polarization method ‎and take an optical microscope with ( 600 X ) for samples after testing. The inhibitors used in this work ‎are thiourea 20 ppm in concentration, and( 20ppm thiourea + 20ppm hexamine ) in concentration.‎
The results show that the adding of the thiourea (20 ppm in 5% and 35% DAP solution ‎respectively)causes increasing the inhibition efficiency to 63% and 60% at room temperature(25 °C), ‎but at 50 °C it is be 35% and 32% . Also the results improve that the current density decreases while ‎inhibition efficiency for both hexamine and thiourea (in 5% and 35% DAP solution respectively) be ‎‎70% and 75% at room temperature and 62% and 64% at 50°C respectively. ‎

The quality of surface waters may deteriorate due to the presence of various polluting ‎parameters such as salts, organic and inorganic matters. Chloride is such a polluting parameter. The ‎presence of chloride, in rivers and streams is due to waste water and drainage water disposal. This ‎study is concerned with evaluating chloride concentration in river Euphrates through Al-Diwaniya city. ‎Chloride variation with distance and time was studied and the effect of its concentration on various ‎uses of the water was evaluated.‎

‎ This work aims to study some of dielectric properties made of kaolin as a matrix material and ‎glass as a reinforcement material. The effect of different additions of glass to kaolin on some ‎properties of the resulting composite is investigated. Five samples are formed in a semi-dry pressing ‎with force about (5 ton). The formulation is achieved by using a template of (1.5) diameter and a ‎period about (1 min). Then sintering for the prepared samples where done. Burning process was on two ‎stages first at ‎‏)‏‎750 oC) ,and remained at this temperature for two hours, and then the temperature of ‎the furnace was raised to the degree of (850 oC).‎
‎ After manufacturing process the properties of these mixtures physical virtual porosity, density, ‎water absorption and electrical strength of dielectric were studied. This study showed that the increase ‎in the proportion of glass results in a reduction of both porosity and water absorption while its lead in ‎increasing the value of the density and voltage collapse.‎
Keywords: kaolin, glass, dielectric.‎

‎ The aims of this research are investigating the effect of admixture of concrete such as SBR,FS70,SP33 ‎on concrete when this admixtures add together .The slump test ,compressive strength and splitting tensile ‎strength where studied on six groups on specimens. First group is reference .second, third and fourth group ‎used SBR,FS70,SP33 respectively in the mixing .Fifth group used FS70 and SBR together in mixing. The last ‎group content from SP33 and SBR in mixing. The result indicated to reduce in activity of SP33 and FS70 ‎when they use with SBR .The increase in compressive strength specimens that content to SP33 about 40% ‎this ratio decreases to be about 23% when SP33 and SBR used together in concrete.‎

Groundwater is one of the important of water resources in Iraq, and it could be used in ‎different fields to avoid water scarce . The search concerned about the ability of using groundwater in the ‎Babylon province as a water for mixing in the concrete mixtures to cover on of these fields representing ‎in creasing demand on constructions and improving the living level of the human . One sample of ‎drinking water and 3 samples of rivers water ( Shat Al-Mahawel, Al-Musaib project river, and Shat Al-‎Hilla river ) have been selected, and then 31 samples of groundwater are taken from wells found in north, ‎midll, and south of Babylon province to include( Qrya-Alassrya , Musaib, Mahawel, Hilla, and Hashmia ‎‎) cities. All samples of water ( 35 samples ) are tested according to Standard Iraqi specifications‎‏ ‏‎(1703/ ‎‎1992 ) as a water for mixing, and in the same time, 3 standard concrete cubic ( 15 × 15 × 15 ) cm are ‎provided for each samples of water ( 105 cubic ) by hypothetical proportion ( 1 : 1.77 : 2.455 , and w/c ‎ratio of 41% as 185 liters / m3 of water and 450 kg/m3 of cement ). The search depends on the theory ‎that said, each unsuitable water or incompatible with the specifications of water mixing, the compressive ‎strength of 28 days should be test, and then compared with respect to those produced by using drinking ‎or rivers water. The results showed that the rivers in Babylon province are suitable as a water for mixing, ‎and also showed that the groundwater in Babylon province is somewhat salty and alkaline type and with ‎variety of chemical component. It is concluded that the groundwater in Al- Hashmia city is suitable as a ‎water for mixing by 100% and could make a concert mixture as the same proportion with those used ‎drinking water, in other hand , the suitable of the groundwater in both Al-Musaib an Al-Hilla cities is 75% ‎and it could be used as a water for mixing in Al-Musaib and Al-Hilla by adding (0.5 sack / m3 of cement ) ‎and (1.5 sack / m3 of cement ), respectively, while, it is found that it is suitable as a water for mixing in Al-‎Mahawel by 45% and could be used when (1.5 sack / m3 of cement ) will be add ‎،‎ and in Qrya-Alassrya, ‎it is found that could be used after adding ( 2 sack / m3 of cement ) to the concrete mixture, because it is ‎be suitable by 80%. The searcher recommends to imitate with Iraqi Standard Specifications‏ ‏‎(1703/ 1992 ‎‎) to protect the steel bar in the reinforced concrete mixture from the corrosion. ‎

This study deals with the biostratigraphy of Najmah Formation in well (K.H 12/7) western Iraq, ‎According to the lithology and Palaeontology, one Biozone has been distinguished (Haurania deserta ‎‎– Pfenderina salernitana – Kurnubia palastiniesis Assemblage zone) .‎
The age of the formation in This study is determanid as Middle – Late Jurassic (Bathonian – ‎Kimmeridgian). ‎

‎ In this paper, several specimens from unsaturated poly ester resin with different filler materials such ‎as (Fe2O3, CaCO3, Cement, Ca(OH)2‎‏(‏‎ have been prepared. Three weight percent have been used as (10%, ‎‎20%, and 30% wt) from each filler materials. Casting samples are grinded by (800) grit using (SiC) ‎grinding papers and then washed by distilled water. Corrosion has been done using immersion test in ‎different period of corrosion time as (2, 4, 6, 8, 10, 12, 14, 16, 18, 22, 24 hours). It has been shown that ‎addition of cement with percent (10% wt) get lower corrosion rate for unsaturated polyester resin.‎

This research aims to evaluate the quality of teaching performance of faculty members in the College ‎of Engineering / University of Babylon. The sample consists of 62 of lecturer "of society reached 225 ‎pedagogy" to the College of Engineering for the 2009-2010 school year. The research specifies the ‎abilities of university teaching in the two areas planning to teach and application of teaching. Adopted ‎the current study the general ways followed by the researcher (Dr. Khaled Khamis Alsir, 2003) in the ‎evaluation of the teaching capacity of professors Al-Aqsa University in Gaza.
Questionnaire based on a series of studies and references in university teaching has been done to the ‎university lecturers. The questionnaire consisted of 45 items concentrated on two sides ; planning and ‎application of teaching .‎
‎ The results showed that the percentage of the evaluated estimations for the sides (first - planning ‎capabilities for teaching) and (II - The capacity to implement teaching) did not reach the quality level, ‎where the percentage of the teaching abilities for the lecturer in the college of Engineering, University ‎of Babylon is ( 61.9%),the percentage of the evaluated estimation for the first side , on the other hand, ‎is (69.8%) , where as that of the second side is (55.6%) .‎

This research is carried out on the soil of university buildings in babil university , while is based on the ‎investigations carried out by the Al-Mawal company in year 2001. The aim of this research is to study the ‎effects of physical , chemical and engineering properties of soil which is important in different construction ‎design.‎
This research included drilling four boreholes , distributed over all area of study. The depth of these ‎boreholes was between (15-17) m e .The evaluation is based on the information's obtained from the field ‎work and the results of laboratory test carried out on the compacted and not compacted samples taken from ‎the soil of study area.‎
The results of this research showed that the soil is clay-silt with small amount of sand to the depth ‎‎13.5m below natural ground surface ,therefore soil classified to clay with high and low plasticity limits, and ‎silt with high and low plasticity limits fluctuating with depth. While for the depth below 13.5 m from the ‎natural ground surface the soil classified to silty-sand with medium to high density. ‎
Chemical Analysis for‏ ‏soil and ground water were conducted and the results shows that ground water ‎is small alkalinity, medium to high in salts and it has harmful amount of sulfates. Result of chemical tests of ‎soil shows that the Sulphat contact of soil between (0.35-1.42)%, Percentage of Organic Matter Content ‎‎(ORG)is (0.037)%,‎‏ ‏Total soluble salts (T.S.S.) between (1.93-5.0)% and Gypsum content between (0.58-‎‎2.67)%.‎
The results shows that number of vales (N) of standard penetration test (SPT) is between (8-48 blow) ‎and water table is between (0.1-0.25)m below natural ground surface (N.G.S).‎
The moisture content (M.C) is between (25.1%-30 %) of samples weight. From the analysis of grain ‎size distribution, the percentage of clay is between (3%-71%), silt between (20%-43%), and sand between ‎‎(4%-72%). Liquid limit (L.L)of soil between (41%-64%), the plastic limit (P.L) is (11%-29%) and the ‎plasticity index (P.I) is (13%-43%). The average value of clay activity was (0.6) and the soil is classified to ‎non active soil. ‎
‎ The dynamic and static methods was used to evaluate bearing capacity of soil cohesive (CU) and ‎friction angle (u), the results shows that the value of (cu) is (1.8-6.1) ton/m2, and (u) is (6-10) in using the ‎static method while in using dynamic method the value is (4-16.4)ton/m2 for different depths. The ‎investigation and lab test showed that soil needs engineering treatments before construct building on it.‎