Muthanna Journal of Engineering and Technology(MJET)

This paper presents the results of study conducted with artificial neural networks (ANN) to determine the effects of the variations of concrete constituents on ultrasonic pulse velocity (UPV) and developed mathematical model to predict the compressive strength of concrete. The proposed input parameters are major factors that affect (UPV), such as cement content, water–cement ratio (W/C), the aggregate–cement ratio (A/C), maximum aggregate size, and age of concrete. The output parameter is the (UPV). The results show that (UPV) increased with the increase in concrete age. Increasing the cement content caused a rapid pulse in velocity readings, and (UPV) increased with the increase in maximum aggregate size. Aside from these factors, (W/C) negatively affected pulse velocity. Also, the ANN model was built to predict the compressive strength of the concrete using pulse velocity and the age of concrete. The results showing good rapprochement between experimental value of compressive strength with predicated value of compressive strength.

In the present study, the effect of process parameters on photocatalytic degradation Bismarck brown Y dye has been examined in a batch reactor under UV light in heterogeneous slurry utilizing various concentrations of different semiconductors commercial catalysts (TiO2 , ZnO , CdS and ZnS). Parameters has been studied (catalyst type, catalyst concentration , pH of dye solution and dye concentration at the beginning). The results show that the best values of TiO2 , ZnO , CdS and ZnS are 1 , 0.5 , 1.25 , 1 g/l respectively and the optimum pH are (10 , 6 , 8 and 10) using TiO2 , ZnO , CdS and ZnS respectively. Moreover the comparative assessment of the photocatalytic efficiency was made for different photocatalytic powder. It was noticed that the best photocatalytic efficiency as ZnO > TiO2 > ZnS > CdS respectively. The percentage removal of chemical oxygen demand (COD) of the dye solutions was higher than that of the degradation of dye for the same conditions of catalyst.

The Place as a cosmic reality perceived by humans during his daily life unlimited in being visually static aware which filled the thinkers and philosophers ,And despite of the predominance of stillness and strap on the place where those in ancient times but that art in General and particular narrative grant place is clear and effective especially in our present time ,There are a lot of terms which approach to the place some related on mention the word ( place ) as equivalent attached or containment or similar approach and some other are including: extension, environment, space, emptiness, position and others of which referred to by specialists. Thus the research problem (lack of cognitive framework for spatial systems role in shaping the architecture) therefore the research aims to create a knowledge base for spatial systems role in shaping the architecture. Because there is an important role search is supposed to place systems outside the field of architecture and the potential impact on the field of architecture, and that there is an effect of the event in the system and its relationship with the place. So the search will focus on studying the concept of place within the field of (Quran – language – geographic literature. meeting – philosophy – engineering) and their relationship to the formal configuration of architecture systems.

This paper is studying the improvement of the power system stability by optimal design of variable structure controller (VSC) and power system stabilizer (PSS) based on Particle Swarm Optimization (PSO). Switching vector and the switching feedback gains optimal values of variable structure controller and optimal parameters of power system stabilizer are finding by using Particle Swarm Optimization (PSO). The variable structure controller and power system stabilizer parameters are tuned optimally to minimize the objective function of the problem. By Using each of optimal (VSC) and optimal (PSS) with the developed model of a single machine infinite bus power system and after comparison the simulation results of two controllers. The results of using the optimal VSC design shows it provides a simple method for arriving to the settings of the VSC and optimal VSC improved the power system stability best than PSS.

This paper aims to investigate the nonlinear dynamic analysis of prestressed concrete bridge girders subjected to impact loading from collision with over-height vehicles. Two cases with/without diaphragms are discussed. The FEM is used to model the prestressed bridge girders. It is assumed that vehicle load is to be in accordance to HS20 of AASHTO 2012 and its velocity is 40km/h. the impact load is modeled as horizontal forces applied at the lower edge of exterior girder at mid span. The addition of diaphragms is found to decrease the lateral and vertical displacements in the girders by up to 86.8% and 84.3%, respectively. A decrease in the longitudinal and vertical stresses by up to 50.6% and 65.8%, respectively is also noted.

Absent text is what is not permissible by the text directly, but he suggests, is not referring to him, but it contained, as well as what he did not say it, but he raised. And research in the philosophy of absence based on research beyond the audience, mainly, in the sense that the framing of our discovery of absence based on our ability to call the system of symbols and signs and signals which are derived from the presence of a signal as part of the installation of any product of creative including architecture by analyzing the construction levels of relational signals or present texts sense rebuilding of mind for the system built is formulated as if they are historical references, social or intellectual been summoned by the present text is hidden or suggestive, the fact that approved absences is rear agreed to attend, and even though the bilateral both sides do not have them attend simultaneously within consciousness, but the the presence of one of them in front of awareness leads to call the other absentee idol. Find current disclosure philosophy of absence in contemporary architecture through the valley in relation to attend connected existential his first and explore its relationship to formulate a set concepts framed, including the difference, displacement, and communication.

Chemical machining is one of non traditional machining methods. It is necessary to study the main foundations of the process and the parameters affecting this process. In this research worked to reach the higher surface smoothness and lowest metal removal when a low carbon steel alloy was machined. Been using this alloy of chemically machined using etchant solution (Ferric chloride FeCl3) .Factors that have been studied: machining time and concentration of etchant where three concentrations were studied (20, 40 and 60%). Each sample was machined by different times (1, 3, 5, 7 and 9 min).Metal removal rate was calculated depending on weight loss due to chemical machining based on corrosion mechanism. Performed tests hardness, surface roughness and an atomic force microscope examination of the surfaces of the samples chemically machined before the process and after it. Results showed that minimum surface roughness recorded in chemical machining when concentration of etchant (60%) and time (1) min. Among the factors used in the study concentration of etchant was the most important influence on metal removal rate and surface roughness.

Internal curing has become a modern technology holds promises for making a durable mortar and decreasing early-age cracking. Since mortar service life is a crucial factor of providing sustainable structures, internal curing can provide a distinct contribution to increase the sustainability of our nation’s building. This study shows results of an experimental investigation of using crushed brick waste (CBW) in cement mortar mixtures prepared by substituting sand by some percentages (5, 10, 15, 20 and 25%) of (CBW). Three curing regimes were adopted in this study: water curing by immersing specimens in water for 28 days, partially water curing by immersing specimens in water for 3 days and left them in laboratory for 24 days and air curing in laboratory for 28 days without immersing samples in water to recognize an ideal methodology for determining whether a given (CBW) can be used for internal curing in cement mortar. Fresh density, hardened density, compressive strength, water absorption, and modulus of rupture were tested. Results indicated that fresh and hardened density, compressive strength and modulus of rupture were decreased with the addition of (CBW). However, they were higher for mortars cured in air conditions than those cured in water and partially water curing. Water absorption was increased with the increase of (CBW). It was demonstrated that air cured mortar give good results for mechanical properties as compared with water cured mortar, hence (CBW) can be used for internal curing in cement mortar especially in finishing works.

Powers compensation of the differential scanning calorimetry (DSC) have been utilized to revealed and analyze the phases of precipitations in the complex quaternary of Zinc (6.7wt. %) _ Magnesium (2.8 wt. %) _ Copper (1.8 wt. %) _Aluminum alloys manufactured by the process of the Semi-Direct Chill Casting. The casted Al-Zn-Mg-Cu alloys slabs were homogenizing at the different temperatures. Firstly under treatment 450°C for 2 hours follow by treatment 470°C for 1 day and then treatment at 480°C for 40 minutes, then all casted samples have quenched in cold water after each step. The treated homogenized Al-Zn-Mg-Cu samples that were underwent the artificial ageing at 120 °C for 1 day, and then retrogression at 180°C for 2400sec. and then reageing at 120°C for 1 day. The outcomes proved that the X-ray diffraction (XRD) analyses confirmed information of the DSC thermal analyses which were obtained through various heat treatments of the three samples AlZnMgCu alloy. The outcomes have explained that the DSC data are helping in understanding the changes the peaks of temperatures as well the enthalpy values for the forming and dissolution the equilibrium phase’s and precipitation compounds within the artificial againg (with the pea-temper) and the Retrograession and Re-Againg- (RRA) treatments were conducting for Al_Zn_Mg_Cu alloy samples.

The objective of this study is to investigate the effect of silica fume and polypropylene fibers to gather on the mechanical properties of concrete and the improvement on general behaviour for deep reinforced concrete beams containing silica fume and polypropylene fibers. Properties studied include Silica fume content used was (0%, 10% and 20%) by replacement of equal weight of cement in concrete. Polypropylene fibers were added in (0%, 0.20% and 0.40%) by volume fraction of concrete. Totally three deep reinforced concrete beams specimens with cross-sectional dimension of (100X300) mm for a length of 1000mm were tested. Out of which three beams provisional on the relation of shear span (a) to the active depth (d) .The (a/d) ratio was used (1) with different containing silica fume and polypropylene fibers with differents percentsge of replacement for silica fume and various Polypropylene fibers were addition.