Journal of University of Babylon

Barium titanates is one of the most important ceramics that are widely used in the electronic industry because of its high dielectric constant, its ferroelectricity, and its piezoelectric properties. In the current study, five different batches of barium titanate powders were prepared by modifiedpechini method using the barium chloride and the titanium chloride as a starting materials in order to obtain different particle size distributions.SEM, TGA, DTA, XRD, FTIR, and other techniques have been used to characterize the prepared samples.XRD results suggested that the synthesized BaTiO3has a tetragonal phase.SEM images of the prepared samples reveala polyhedron shapes, on average, also it show that there are markedinfluence of the reactant concentration on the average size of the grains,where the samples prepared from higher solution concentration tend to possess larger grain size compared to that prepared from low concentration.

The signal de-noising based on waveletthresholdingis subjected to the value of threshold and how the way selection for it. Thismadea threshold value acts as an oracle which distinguishes between noise and signal.To date, there havebeen several methodsdeveloped to predictthe value of thresholddepending on statistical calculationsfor the noisy signalassuming that there is some priori knowledge for original signal and noise distributions.In fact, in any practical issues, only theobserved noisy signal that wehold.Therefore, in this work, an intelligent modelis developed to estimate the value of thresholdwithout any priority of knowledge for these distributions. This is done by implementingthe Particle Swarm Optimization (PSO) algorithm for kurtosis measuring of the residual noise signal to find an optimum threshold value at which the kurtosis function be maximum. These residual noise signal can be estimated by applying an inverse threshold function to the detail coefficients of the DWT. This model has been validated by comparison the results with the statisticalmodels and shows strong agreement for the obtained threshold parameter.
Computer simulation for proposed model was implemented using MATLAB2011 as follows:At first, the kurtosis measuring for residual noise was analyzedusing three different signals with four SNR levels. Through this step we found that: there\\'s a single value for the threshold that maximizes the kurtosis of residual noise. Then, the PSO algorithm was implemented to find this optimumvalue.At the same time, it\\'s noticed that the PSO algorithm with ten swarmprovidesa convergence speed about (20~ 30)iterationfor any signal distribution at any SNR level and for each decomposition level.Finally, the mean square error (MSE) was used to evaluate the performance oftwo and five decomposition levels for each tested signal.

This study explained the effect of calcium carbonate on extraction of cadmium from contaminated soil with different extracting agent and surfactant (0.1 M EDTA, 1 M AA, and 1% SDS) (single or mixed extracting agents with surfactant, SDS).The extractedCadmium was more, when 0.1 M EDTAwas used at a pH above 5. Here, the extraction of cadmium from contaminated soil by 0.1 M EDTA decreased with the increase of calcium carbonate content for soil. The extraction of cadmium was moderately effective, when the concentration of acetic acid (AA) was 1.0 M. When the use of 1% SDS alone was ineffective for extraction of cadmium. But, the combination of 1% SDS with 1 M AA was highly effective in the extraction of cadmium. While, the addition 1% SDS to 0.1 M EDTA played only a slight role in the extraction process.

In this paper, shear behavior of reinforced hybrid concrete connection of corbel-column is experimentally investigated. Nine homogenous and hybrid concrete corbel-column connections subjected to vertical applied loads were constructed and tested within two test groups (A, B). The experimental program included the effect of several variables such as type of hybrid concrete;high strength concrete (HSC) or steel fiber reinforced concrete (SFRC), monolithic casting of hybrid concrete connection, and presence of construction joint at the interface of corbel-column. Experimental results showed significant effects of concrete hybridization on the structural behavior of connection specimens such as: ultimate strength, cracking loads, cracking patterns, and failure modes. Hybridization process in group (A) included hybrid connection of corbel-column with HSC or SFRC corbel instated of NSC. This process led to increase the capacity of connection by (26%, 38%) and shear cracking loads by (20%, 120%) respectively. Moreover, connections of hybrid concrete corbels cast monolithically improved the shear capacity of corbels by (19%, 42%) for HSC or SFRC respectively. In group (B), presence of construction joint at connection region reduced the shear capacity of connectionsby (10% to 22%) and cracking loads by (23%-62%) compared with connections cast monolithically.

This paper presents firstly a buck-boost circuit with the advantage that its output voltage polarity is the same as the input polarity. The circuit operation is presented and analyzed in different modes of operation.
The well known parameters used in evaluation of DC/DC converters like Total Harmonic Distortion THD, Power Factor PF, and Ripple Factor RF have no meaning in DC/DC converters, so it is to introduce efficient concepts to permit a fair evaluation of the converter.
This paper present other parameters that can be used to study the characteristics of the converter and gives a real and logic means of its operation. These main parameters are: pumping energy PE, storage energy SE, energy factor EF, and energy losses EL. In addition, the converter efficiency is not considered as 100 % as taken in most analyzing studies.
The positive DC/DC buck-boost converter is evaluated according to the new concepts and the system model is deduced for different cases of operation taking into account the resistance of the circuit inductor. The circuit is implemented practically and the presented obtained results show the correct operation under different modes of operation.
In addition the control design of the converter is built such that a PI controller with windup is considered. In order to test the effectiveness of the designed control algorithm, the system were exposed to different voltage reference values and the obtained results demonstrate that the system responses for all cases are very acceptable according to the criteria of the control system theory.

Similar NiTi shape memory alloy(SMA) plates, 420 Martensitic stainless steelplates and dissimilar NiTi shape memory alloy with Martensiticstainless steel were welded by a pulsed Nd:YAGlaser welding method.The nature microstructure of the base metal (BM), weld zone (WZ), interface and the heat affected zones(HAZ) were showedby in a scanning electron microscope (SEM) and optical microscope.Vickers hardness tests wasconducted to specifythe properties of the weld. The outcomes showed that the hardness of dissimilar NiTi-Stainless steel (St.St.) weld is higher than that in similar NiTi-NiTi and St.St.-St.St. weld.TheMicrostructural examination in both NiTi-St.St. and NiTi-NiTi welds illustrates that the solidification process in the fusion zone changed the kind of plan to the cell type as well as the changes that occur in the cell to dentritic kind of intra- region of the weld through the weld center in the welded sample sides but in the St.St.-St.St. weld showed dendrite microstructure. In this study it is found that the increase of the welding speed leads to a decrease in hardness in all jointsNiTi-NiTi, NiTi-St.St. and St.St.-St.St.

Educational institutions are one of the main trip generators and distributors in the cities around the world. The main campus of the University of Kufa has more than 10 faculties with more than 12,000 people (staff and students). This makes the university is one of the high attracting area of trips in the city. These attracted trips use different modes of transportation such as taxi, private car, min-bus and even walking mode. This study aims to investigate the travel behavior and travel patterns for the current trips and put the suitable suggestions for shifting the travel characteristics using efficient modern modes of transportation. More than 4000 samples have been investigated using interviews asking about the origin, the purpose of trips and the mode of trips. The results of this analysis indicate the urgent need for improving the current transportation system by encouraging public transport such as bus and tram. Moreover, there is a need for improving the design and traffic management for the gates of the university.

In the present study, ground water samples were gathered from differentregions located inHillacity during period from October 2014 to September ,2015.
Water samples were taken from ten wells (monthly two samples from each well) in different regions for analyzing laboratory for thirteen parameters, they are: Temperature, pH , Electrical conductivity (EC), Total hardness (TH), Calcium (Ca+2), Magnesium (Mg+2), Chloride (Cl-1), Sulphate (SO4-2), Nitrate (NO3-), Sodium (Na+), Potassium (K+) and Total Dissolved Solid (TDS) . The evaluation of water suitability of the present study for drinking and other irrigated purposes was achieved by means of arithmetic method of WQI depending on guideline values of (WHO,2004) and Iraqi Standard No.417 for (2004) .
Values of WQI ranged from (97.230 - 79.100)at Hilla city which is not suitable for human consumption according to the classification of Iraqi Standard No.417 for (2004) and WHO ,2004. These values belong to high water electrical conductivity and chloride of the studied wells comparable with other parameters. Also, correlation coefficient supports this interpretation where there are strong positively correlation between WQI values and both electrical conductivity and chloride values (0.997, 0.919 respectively).While in the assessment of ground water quality for irrigation, electrical conductivity, pH, sodium absorption ratio (SAR), chloride,slphate, sodium, calisum and magisumwere used to calculateWQI values which range from (98.074- 83.187). These values are associated with both EC and Cl- in a strong negatively correlation (-0.968, -0.969 respectively).
Application of Visual Basicsoftware is a good tool to explain the WQI index for all types of rivers and streams in Iraq, that will be useful to give fast indication about WQI index.

Double-cladding large mode area rod-type photonic crystal fibers have become a key component for power scaling in high power fiber laser systems to provide an ultra large effective area. By a careful design, the single-mode regime can be obtained insuch large core active fibers. In this paper, the 19-cell photonic crystal fibers with 3 rings in the fiber inner cladding have been investigated with the avoided-crossing approach, in order to find guidelines for the design of single-mode fibers. The air-hole diameter and the wavelength have been changed.In a certain point of air-holes diameter and the wavelength for 19cell PCF, the avoided crossing between HOMs has been occurred. In this point, the confinement loss of HOMs is increased which is more ensured for SM operation.

Evapotranspiration (ET) is important for hydrological practices, water planning, and it plays an influential role in the design, operation and management of irrigation systems. There are a number of methods suggested to estimate reference evapotranspiration (ETo). Detailed meteorological data required for the equation of FAO-56 Penman-Monteith (P.M) method that was adopted by Food and Agriculture Organization (FAO) as a standard method in estimating reference evapotranspiration (ETo) are not often available, especially in developing countries. In this research the possibility of estimating reference evapotranspiration using fuzzy logic control in BasrahCity is studied. The four models of fuzzy logic are constructed based on the available meteorological data in BasrahCity during the period (1990-2012).Various combinations of long-term average monthly climatic data ofair temperature, relative humidity, wind speed and solar radiation are used as inputs to construct four models of fuzzy logic. Fuzzy logic models evaluated based on root mean squared error (RMSE) and coefficient of correlation (R2).Depending on the values of RMSE and R2, model No.4 with input parameters (Tmean, Tmin, Tmax, Rh, Ws, Rn)give the best values of estimated (ETo), it gives a RMSE and Rvalues of 0.094 and 0.998 ,respectively. Fuzzy logic models have high efficiency in estimating the reference evapotranspiration values.

This paper is concerned with transmitting signals of Digital Video Broadcasting (DVB) properties using Field Programmable Gate Array (FPGA) using Verilog code to achieve this goal. DVB is a technique used an outer code (Reed-Solomon), inner code (convolutional code) and interleaver in between them. the properties of Reed-Solomon is (204, 188), convolutional code is a 1/2 and interleaver of depth I=12. The method used to programming the FPGA is schematic and Verilog code.

In this research study the effect of addition of zinc on the mechanical properties (Hardness , yield strength , Ultimate stress) for pure aluminum and also microstructure , density , addition to the electrical conductivity , three alloys were prepared by change ratios add zinc ( 10% , 20% , 30% ).
The results showed that increased proportion of zinc added to pure aluminum caused an increase in the yield stress and improving ratio reach to 84.86% and also an increase in ultimate stress and improving ratio reach to 78.58% at ratio(30 % ) ,and an increase in the hardness reach improving ratio to 43.45% at ratio (30 %) while the decrease in electrical conductivity to the value of (0.703*106-1 .m-1 ) and increase in the density and improving ratio reach to 13.814% when the ratio of zinc added to the pure aluminum increases , a change in microstructure and regular distribution of zinc on the boundary of crystalline for alloys, has also been noticed.

This paper is devoted to study the effect of length of symmetrical overhanging edges on the absolute maximum bending moment of uniformly loaded simply supported reinforced concrete beams. Successful implementation demonstrates the abilities and performance of STAAD Pro V8i which is the most popular structural engineering software products for 3D model generation, analysis and multi-material design. All calculations had been carried out done based on elastic analysis and the ultimate strength method of design as per ACI 318M-14 code requirements for flexural and deflection constraints.
It is approved that the beam with optimallength of overhanging edge (l_c) equal to 0.35 the beam length between supports (l_m) has equal maximum positive bending moment and maximum negative bending moment and optimal absolute maximum bending moment compared with the same beam but with other lengths of overhanging edges. Different beams cases had shown that the area of tension reinforcement may be increased up to 120% when the length of overhanging edge is away from the optimal length ofoverhanging edge of the same beam. The convergence from the optimal length of overhanging edge may lead to good relative economy of the beam.

In this study (Cu-13Al-4Ni-xCr) shape memory alloys have been prepared by using Powder metallurgy technique with added Cr element (x=0.3,0.6,0.9) . After compacted , sintering process has been done in vacuum pressure (10-4torr) at ( 550oC for 120 minute) and ( 900oC for 60 minute) then cooling inside furnace.Quenching heat treatment carry out at (850oC for 60 minute) then cooling in cold water to (3-4oC) .
The microstructure has been studied by optical microscope and scanning electron microscope (SEM) , porosity , compression behavior(stress-strain) for quenched specimens also have been studied .
The results have been approached that the hardness increases with percent chrome while the porosity decreases . The compression stresses to fracture , have been increased with respect to (0.3%C) had porosity (27%) and decreased for (0.9%) has porosity (22%) . from the previous results , quenched alloy (Cu-13%Al-4%Ni-0.3%Cr) is the more compression strength

This research presents the results of experimental work on the various properties concrete paving blocks (CPB) made with concrete containing different mineral additions.in this study, three types of mineral additions;Fly Ash (FA),Metakaolin (MK) and Silica Fume (SF) were used. Thirteen concretes mixes were cast at a water/binder ratio of 0.45 with 0, 5, 10,15and 20% cement replaced by either Fly ash,Metakaolin or Silica Fume. Theconcrete mixes were tested for slump, compressive strength, water absorption, and abrasion resistance.Metakaolin-contained concrete showed a better workability than fly ash and silica fume concrete. As the replacement level wasincreased, the 28-days compressive strength of the CPB containing MK increased similarly to that of the silica fume-containedCPB up to 20% replacement ratio. The replacement ratio of MK and SF from 5 to 20 % reduced water absorptionof CPB from5 to 19 than that of control mix. The increase in replacement ratio of MK andSF from 5 to 20 % leads to increasing abrasion resistance from 8 to 18% that of control mix.

Shatt Al-Kufa ( Kufa River) is the main supply of surface waters in Najaf, it is necessary to concern about the river water quality because of increasing demand for different using. This study aims to find the Water Quality Index ( WQI) for irrigation use at many locations on Shatt Al-Kufa within the study section of the river. Nine water quality parameters: Sulfate (SO4 -2), Chlorides ( Cl-1), Total Dissolved Solid (TDS), Electrical Conductivity (EC), Hydrogen Power ( pH), Calcium (Ca+2 ), Magnesium ( Mg+2 ), Sodium (Na+ ), and Potassium ( K+) were studied over ten months ( January- October 2014) for nine locations along the study section. Sodium Adsorption Ratio ( SAR) and Soluble Sodium Percentage ( SSP) were also calculated. Firstly Food Agricultural Organization ( FAO, 1985) was adopted to evaluate the suitability of water for irrigation use. Then Canadian Water Quality Index ( CWQI ) was applied to classify the water quality index of the river for irrigation. It is found that the mean values of parameters for all selected locations are within the highest allowable limits of FAO classification for irrigation, with respect to the values of ( SAR ) the results showed that the water samples were within the level ( S1 ) which there was no harmful effects from sodium, while ( SSP ) values ( except one value ) fall within the water class of good according to Todd classification of irrigation water based on SSP. Results of the annual and seasonal average water quality indices according to the Canadian method were classified as Fair ( 65 – 79 ) in all selected locations. The effective reason which decrease the water quality index, was the presence of high values of ( EC ) and high concentrations of ( TDS ) in all locations, which it refers to high concentrations of salts. Approximately 100 % of EC and TDS water samples have concentrations that exceeded the permissible limits for irrigation water.

Long Term Evaluation (LTE) networks can be categorized as a member of the third generation of mobile communication system, and it is capable of supporting real time multimedia and a variety of broadband technologies. In order to satisfy customers, these technologies must be transmitted with a good level of Quality of Service (QoS). This can be achieved by fulfilling a number of requirements such as lowest possible packet loss rate and delay. While from a provider’s perspective, improving the systems performance by efficient and fair spectrum allocation is challenging issue. As known, these requirements are mainly managed by the scheduler at the transmitter side. In this research, a novel algorithm of scheduling is proposed and implemented for real time applications in the downlink of LTE networks. The proposed algorithm reduces the number of packets that has been dropped due to congestion as well as the number of lost packets due to bad channel quality, and thus enhancing the system performance. It also prioritizes the user with the highest packet loss rate by taking into account the packet loss rate of each user and maintaining the metric of fairness within normal levels as the number of users increases. Also the system capacity, throughput and modulation order were increased by taking advantage of the Adaptive Modulation and Coding Scheme (AMC). The proposed algorithm has proven to be more efficient in terms of system performance than similar algorithms

This research studies some of the mechanical, thermaland physical properties for a polymer blend of polypropylene(PP)&low density polyethylene (LDPE). The blend compositions under studying were(pure PP, 25LDPE/75PP,50LDPE/50PP,75LDPE/25LDPE,pure PP). From the results it can be observed that the addition of LDPE to PP has been declined the tensile strength, flexural strength, flexural modulus and hardness while the density improved . the superior tensile strength was obtained at (25LDPE/75PP) composition while preferable flexural strength was ascribed to (50LDPE/50PP) blend composition.

This work tries to study the using of bromobutyle / butyle elasomeric blends in ultrasonic transducers as a dry plastic interfacial media to inspect porous materials such as concrete and refractory materials which can absorb liquid medias , through the study of acoustic impedance characteristics at interfaces . These characteristics include acoustic impedance , the percentage of energy reflected, dB loss, Power ratios expressions , and Pressure ratios expressions (Reflection Coefficient & Transmission Coefficient ). They are studied by using ultrasonic instrument named CSI (type CCT- 4) with 26 KHz frequency . Also, this research try to specify the suitable bromobutyle / butyle blend for immersion inspect through the matching between the acoustic impedance of the blend and that of water. Samples preparation achieved in Babylon Tiers Factory.
Results showed that by increasing bromobutyle ratio in the blend both reflection coefficient and the percentage of energy reflected increased while acoustic impedance and Transmission Coefficient have been decreased. Also, the results show that 20 bromobutyle / 80 butyle is the suitable blend for immersion tests.

The use of Steel Fiber Reinforced Concrete (SFRC) is to improve the structural behavior such as increasing the resistance to cracking and crack propagation. This work has been made to study the properties of polymer modified concrete when micro-steel fiber is incorporated at different volumetric percentages from 0.1 % to 2 %. Two mixes (1:1.5:2 and 1:2:4) have been used and modified with styrene butadiene rubber resin (SBR) and silica fume with maintaining water cement ratio at 0.45. It has been found that increasing steel fiber content in concrete has a significant influence on the increase compressive, tensile, flexural strength, modulus of elasticity and stress- strain relationship. Flexural strength increases from 4.14 MPa (for 0% steel fiber) to 11.83 MPa (for 2% steel fiber). Whereas, the modulus of elasticity is improved by about 77% (for 1:1.5:2 mixes) and 91% (for 1:2:4 mixes).

Tigris River is the main water source for all water treatment plants in Baghdad city. In current study, Water Quality Index (WQI) and microbial pollution was obtained for two water treatment plants and their networks in Baghdad city Al-Karama and Al-Wathba WTP for both raw and treated water, In order to assess water suitability as a source of domestic water supply. Physical, chemical, and Microbialparameters werestudied fora period of four months (March-June, 2014). The parameters which were taken into account for the present work are pH, turbidity (Nephelometric Turbidity Unit), Total Alkalinity (TA), Electrical Conductivity (EC), Calcium (Ca++), Magnesium (Mg++), Total Hardness (TH), Total Dissolved Solids (TDS),Chloride (Cl-), and Most Probable Number (MPN) method as microbial pollution indicator. The results indicate that WQI for untreated Tigris water was classified as \"unfit for human consumption\" at both WTPs intakes and along study period and after water passing through the sequence treatment units in WTPs its quality is gradually increased and finally, the treated water quality ranged from \"Good\" to \" Moderately polluted\" at both All-Karama and Al-Wathba WTPs. In networks the quality of water ranged between \"Good\" to \"moderately polluted\" in Al-Karama WTP network and between \"Moderately polluted\" to \"severely polluted\" in Al-Wathba WTP network. For Microbiological pollution, MPN throughout the period of study was between (0-150 cell/100ml) at Al-Karama WTP and between (0- 240 cell/100ml) at Al-Wathba WTP. The highest value obtained was (240 cell/100ml) at raw water in Al- Wathba WTP intake in June, while the lowest value obtained was (0 cell/100ml) at all chlorinated samples.

This paper presents an experimental investigation on punching shear behavior of continuous bubbled reinforced Reactive Powder Concrete (RPC) slabs. Bubbled slab is one of the various types of voided slabs. It consists of bubbles placed inside a concrete slab which will reduce the self-weight of the structure by about 35% (Tina Lai 2009). On the other hand, using RPC make it possible for structural member to have smaller dimensions due to the great strength of this type of concrete. In this study, these two method to increase the building spaces dimensions by reducing self-weigh of the structure by using bubbled slabs and to decrease the structural members\' dimensions by using RPC have been investigated together.
To study the punching shear behavior of continuous bubbled flat slabs such as the ultimate load carrying capacity, central deflection and slabs crack pattern at the ultimate load, nine different types of slabs were tested. The parameters of the study were type of concrete (RPC and Normal Concrete (NC)), bubbles diameter to slab thickness ratio (D/t) of (0.6 and 0.7), bubbles location (at all slab area, started from distance D and 1.5D from the center slab) and solid slab.
The test results show that the crack pattern and ultimate load capacity as well as maximum deflection depends on all of the mentioned parameters, were by increasing (D/t) ratio the ultimate load capacity increases about (6.49 and 9.58%) for slabs with bubbles started at distance 2D and 3D, respectively. But in the slabs with bubbles at all slab area the ultimate load and the maximum deflection decreases about (6.63 and 9.47%) and (7.96 and 6.84%) for RPC and NC slabs, respectively. Also, the solid slab increases the ultimate load about (5.28%) compare to bubbled slab at all area.
It was found that by removing bubbles from center of the slab at distance 2D and 3D the ultimate load will increase about (14.72 and 8.76%), respectively for slabs with (D/t = 0.6) compare to slabs with bubbles at all slab area, and for slabs with (D/t = 0.7) the ultimate load will increase about (30.85 and 27.65%), for bubbles at distance 2D and 3D, respectively.
Using the NC decreases the ultimate load compare to RPC by about (52.82-54.25%) for different (D/t) ratio.

In this research study the effect of addition of magnesium on the mechanical properties (Hardness , yield strength , Ultimate stress) for pure aluminum and also microstructure , density , in addition to the electrical conductivity . three alloys were prepared by change ratios add magnesium ( 5% , 10%,15% ).
The results showed that the increase proportion of the magnesium added to pure aluminum caused an increase in the yield stress and improving ratio reach to 78.46% ,an increase in ultimate stress and improving ratio reach to76.92% at ratio(15% ), and an increase in the hardness to value (91.9 Hv) and improving ratio reach to 90.78% at ratio (15 %) while the decrease in electrical conductivity to the value of (0.596 *106 -1 .m-1 ) while there is a decrease in the density to (2.371 g/cm3 ) when the ratio of magnesium added to the pure aluminum increases. A change in microstructure and regular distribution of magnesium on the boundary of crystalline for alloys , has also been noticed.

The dynamic optimization procedure for n-dimensional vector function of a system, the state of which x=(x_1,\"\\.\\.\\.\",x_n )^T is interpreted as adaptable immune cell, is considered Using the results of the theory of artificial immune systems. The procedures for estimate of monitoring results are discussed. The procedure for assessing the entropy is recommended as a general recursive estimation algorithm.
The results are focused on solving the optimization problems of cognitive selection of suitable physical resources, what expands the scope of Electromagnetic compatibility.

A COMSOL Multiphysics software depended on finite element numerical solution is used for prediction the spatially and temporally propagation of the benzene front as non-aqueous phase liquid through the stratified soil consisted of clay and Kerbala’s sand as domain (1.3*2) m. The variation of many parameters such as capillary pressure, benzenedistribution, trans missive properties of the soil.Thedegree of saturation as a function of capillary pressure and relative permeability during unsaturated conditions were determined.
The results showed that the benzene front in the Kerbala’s sand with presence of clay retained a regular, circular shape at the initial stage of the spill, shortly after that it become ellipsoid as it was advancing. The maximum saturation occurred below the source of the contaminant during infiltration stage. All analysis showed that the presence of clay layer controls the vertical movement of NAPLs in heterogeneous porous medium.

Four operational cyclic modes for a Sequencing Batch Reactor containing activated sludge was investigated in order to treat a part of domestic wastewater from the student\'s hostels at B campus in Chongqing University in China, comparison was made for these cyclic modes (first, second, third and fourth)in order to remove (COD, Ammonia), each cyclic mode operated in a different conditions as aeration time, cyclic time and concentrations in order to choose best cyclic mode gives a good removal efficiency and in the same time explain effect aeration time on removal COD and Ammonia by using sequencing batch reactor under normal temperature. The results showed that the CODremoval efficiency that has been achieved by SBR system were 90.14%, 87.86%,83.1%and 81.3% under first, second, third and fourthcyclic modes respectively, while Ammonia removal efficiency were 84.56%,74.82 %,52.74% and 32.53% under first, second, third and fourthcyclic modes respectively.

The paper aims to work theoretical study by using three reactions for the wood burning analysis or (Wood Gasification). First, we suggested a general equation with molar balance modified for the burning. Results obtained, we solved multivariable nonlinear equations non-linear equations by means of Newton-Raphson method. Using the computer program Matlab, we calculated the degree of equilibriums heat for the reac285tions absolute (946 ok, 763 ok, and 67 ok). Also, we calculate thermodynamics functions for the reactions (ΔG, ΔH, K) with two ΔH+ (non- impulsive) and one ΔH-(impulsive).

This paper presents and validates a single degree of freedom (SDOF)analysis method of steel beamssubjected to airs blast loadsinduced by explosions. The method usesa quasi-static non-linear resistance function of beams under uniformly distributed pressure.The non-linear resistance function has been implemented in a single degree of freedom analysis procedure to determine the nonlineardisplacement –time history of the steel beams subjected to air blast pressure.Strain rate effects have been accounted for usingthe well-known Cowper Symonds equation by differentiating the corresponding strain rate equations. Thesuggested SDOF analysis method was validated against the available experimental tests results using two W sections steel beams subjected to different values of the blast pressures and impulses. The validation results have indicated the accuracy and reliability of the suggested method to predict the nonlinear response of steel beamsunder transverse air blast pressure.

The needing of using clean energy increases every year because of the negative impact of emissions from electricity power plant and to reduce the costs of generating power by using natural energies like solar, wind, and other sources.
The availability of using solar energy as source of producing electricity in Al-Hilla city by using Concentrating Solar Power (CSP) was investigated in this research. The major parameters in this study were the city position, and the annually amount of solar received, also, number of charts related to solar parameters for the management of CSP were derived and showed in this research.
The using of CSP as electricity power can be important solution to force the problem of high cost of electricity power fuel needed and the lack of power produced because of increasing of power consumed specially in summer season.

Free space optical (FSO) communication is a cost effective andhigh bandwidth access technique. The fading of received signal that induced by the atmospheric turbulence is the major impairment in the FSO links. Receiver spatial diversity is one of the atmospheric turbulence mitigation techniques that usedfor improving the system performance. This paper presents a performance analysis study of a single input multiple output (SIMO) spatial diversitytechnique for the terrestrial FSOlink. The achieved performance improvements over atmospheric turbulence channel for different turbulence levels show the effectiveness of the spatial diversity technique to mitigate the channel turbulence effects. A lower bit error ratesand higher diversity gain is achievedby increasing the number of receiver photodetectors.

In Iraq , the increasing in number of vehicles and trucks with their heavy traffic loading and under high temperature , a variety of pavement distresses continues to develop affecting the performance and economy of pavement construction. Polymer modified asphalt mixtures have been used to resist the distresses that produced and developed from the applied stresses. Several distresses effect on the performance of HMA. The primary forms of distress are fatigue cracking , rutting , moisture damage and thermal cracking. These distresses reduce the services life of HMA and increase the maintenance costs.
The main objective of this research is to find the effect of polymers on the performance of asphalt mixtureby using one asphalt cement grade (40-50) from Al-Daurah refinery with two types of locally available polymers (Low-Density Polyethylene LDPE and Styrene Butadiene Styrene SBS) with three percentages for each type. These percent are (1, 3 and 6) % for (LDPE & SBS) by weight of asphalt cement. Each type of these polymers is blended with asphalt cement by using the wet process. The experimental work showed that all polymer-modified mixtures have stability and indirect tensile strength higher than the control mixtures. It can be concluded that the addition of (1% LDPE) and (3% SBS) to asphalt mixtures showed better improvement on the performance properties of pavement modified with these polymers , in which the referred percent represent the optimum percent of concentration for blending polymers .

In this paper sixteen specimens of single and double shear connections have been investigated. Specimens have been equally divided between the two types of connections . For both connections, all bolts have been positioned in parallel direction with applied loads .Steel plates of 4,6.8 mm have been used to configure both types of connections.The results indicated that the bearing capacities of double shear connections were higher than their peer of single shear connections.The deformations around holes werevery large in double shear connectionswhile they were a little in single shear connections.The common attribute between the two types of connections was the overestimation of theoretical values to experimental values but with different ratios.

The present work is a numerical comparative study for low GWP refrigerants based on R161, R152a, R1234ze(e) and R1234yf as a substitute for R134a in a vapor compression refrigeration cycle under varying operating conditions. A computational model is developed by engineering equation solver software (EES). The effects of degree of subcooling, superheating, evaporating and condensing temperatures on the main performance parameters in term of mass flow rate of refrigerant, pressure ratio, volumetric cooling capacity, compressor input power and coefficient of performance are computed for selected refrigerants. The performance results are compared with respect to R134a. The results indicated that the coefficient of performance for R152a is slightly better than the other refrigerants under various operating conditions. The refrigerant R1234ze(e) has approximately the same COP and VCC of R134a and it has the lowest compressor input power and TEWI value over the four compared low GWP refrigerants.