Engineering and Technology Journal

The lack of reliable municipal water supply in the city of Port Harcourt has led to indiscriminate drilling of boreholes by the residents however, the direction of groundwater flow within the entire city has not been established. Hence, the research investigated the flow direction of groundwater in the study area in order to understand the best location for siting septic tanks and dumpsites with respect to the position of the existing or proposed borehole. This was achieved by determining the hydraulic heads (Hh) of twenty boreholes evenly distributed within the city by subtracting the static water level (SWL) from the corresponding earth surface elevation (E) with the use of a GPS and dipmeter. Results revealed that the hydraulic heads ranged from 0.14 – 23.16m while the surface elevation and static water level lies between 1.93 – 39.33m and 1.79 – 17.27m respectively. The contour map of the hydraulic heads indicated that the groundwater flows towards the southern and south-western directions hence, the residents were advised to take into cognizance when sitting dumpsites, landfills, and septic tanks with respect to proposed or existing boreholes

Aluminum – based metal matrix composite are widely used in industrial applications compared with conventional and unreinforced alloy. The composite materials usually exhibit a higher strength both at elevated and ambient temperature, as well as wear resistance. The production of composite materials which contain different weight percentage of ZrO2 (0.5, 1.5 and 2.5wt %) by stir casting process. The mechanical properties of the base alloy and composite were evaluated by using tensile and hardness tests. The microstructure inspection by optical microscopy, scanning electron microscope and energy dispersive spectroscopy (EDS) were utilized to study the fracture surface topography. The results represent that the hardness, strength of yield and tensile strength increased with increasing the weight % of ZrO2 to 2.5 % while the elongation decreased. The microstructure inspection by optical microscope shows that the dendrites structure and the particles distribution in matrix without any voids. Furthermore, the grain size refining with the weight percentage of weight reinforcement elevated.

The pace of daily life and its requirements are getting higher and are led by technology with its direct effects on the health of the individual. There is no doubt that its benefits are endless but its negative effects on the health of the user have become clear, to reduce the negative energy accompanying it to the lowest level by facing another positive energy that is superior to restore the balance first, and overcome it to be the dominant feature of space, the house is the most important place where individuals spend most of their time, which imposes on the designer not be specialized not only to the forms and relations but beyond to form the modern house itself with power to reset the balance of life in general. The house based on Islamic foundations is featured with great energy that has been reflected as positive energy on the residents which is necessitated studying to use in the formation of modern houses with energy. The problem of research was (a knowledge gap about the energy sources in the house according to the Islamic perspective and employment it in the contemporary house). The research aims to study the house in accordance with the Islamic perspective and its relation to energy and determine the elements of its composition and organization through a theoretical framework for the process of energy composition of the Islamic house and the revealing what is verified in contemporary production, the study concluded to depending

The present study involves a coherence steps to re-analyze the scenario of presence of collapsible gypseous layers in the foundation of Hadithah dam under extreme operating conditions. The motivation for such analysis was to explore the problem of construction and operation of large earth dams on collapsible soils if similar cases exist in Iraq. This study was carried out to evaluate the adequacy of the diaphragm wall and the safety level of the side slopes during the drawdown and rise period. The results were verified by the in situ design that confirmed the validity of the analysis

This paper aims to conduct a series of laboratory experiments in case of - throat width (not presented before) of the cutthroat flume. For this size, five different lengths were adopted 0.535, 0.46, 0.40, 0.325 and 0.27m these lengths were adopted based on the limitations of the available flume. The experimental program has been followed to investigate the hydraulic characteristic and introducing the calibrated formula for free flow application within the discharge ranged between 0.006 and 0.025 m3/s. The calibration result showed that, under suitable operation conditions, the suggested empirical formulas can accurately predict the values of discharge within an error ± 3%.

The probability of debris accumulation near bridge piers during the heavy storm and river flood convert the hydraulic action of flow and increase the scour depth due to the reduction of flow area and the increase in velocity of flow. In this paper, the effects of debris accumulation length, width and submerged depth on scour depth near bridge pier were investigated. An experimental study for three groups of woody debris accumulation was conducted under clear water condition to investigate the effects on maximum scour depth. The results showed that the increase of blocked area of debris to 27% increases the scour depth by approximately 140%. Furthermore, two empirical exponential formulas was proposed to predict the effect of debris on the maximum scour depth and the modification factor required for single pier. Well agreement was obtained for both derived formulas with coefficient of determination (R2) of 0.96

These works study the characterization of thermal and acoustic insulation behavior of Polymer Blend/Recycled Natural Fibers. Acoustic insulation is an important property in design criterion in buildings and used to avoid the damage caused by the sounds of the explosion of rockets and bombs. This work is done through reinforcing 80% epoxy resin EP with 20% polycarbonate PC with two different recycled natural fiber RNF (hemp fiber H.F., cornhusk fiber C.H.F) at various weight fractions of (2,4,6) %, the samples, were formed by hand lay-up then the acoustic and thermal insulation tests carried out. The results show that altering both kinds of RNF can improve acoustic insulation. Also, it could be noticed that sound insulation efficiency can improve with increasing RNF weight fraction. Finally, the optimum results got at 6% hemp composite that shows better acoustic insulation than cornhusk composites. The thermal conductivity improved by increasing the fiber weight fraction. The maximum value of thermal conductivity for composite samples with (H.F., C.H.F) fibers at (6% wt) equal to (0.71609W/m. Kº) and (0.73686W/m. Kº), respectively. The composite samples with C.H.F. fibers have slightly higher thermal conductivity value than composite samples with H.F.

Shell structures are liable to different kinds of defects and damage like cracking and corrosion which may destroy their structural safety and affect the service life. The cracks' effects are significant considerations in the design of cylindrical shell structures as they influence the vibration characteristics and safety. This present work is an experimental study on the free vibration analysis of a cylindrical shell involving circumferential surface crack. The influence of the ratio of shell’s radius to a shell’s thickness (R/h)of the shell structure, crack length in the shell, crack depth in the shell, crack location of the shell, and crack orientation in the shell are investigated under a clamped - clamped and simply supported boundary conditions at each end in the shell. Results showed that the minimum impact of the crack is at the angle of crack 75, and the circumferential fissure has more effect than a longitudinal fissure, In addition to this, under SS-SS, C-C the natural frequency will decrease if the fissure is located in the middle of the shell is greater than other locations. but when crack animated across in the ends of the limits the decrease in the natural frequency under C-C only. Results were compared with the literature there was a close agreement.

Directional sensors in wireless visual sensor networks attract growing attention as a promising tool for monitoring the real world; directional sensors consume energy for two main tasks: sensing and communication. Since a VSN contains a number of configurable visual sensors with changeable spherical sectors of restricted angle known as a field of view that is intended to monitor a number of targets located in a random manner over a given area. Therefore maximizing the network lifetime through minimizing power consumption while covering the targets remains a challenge. In this paper, the problem of obtaining a disjoint set cover includes a minimum number of camera sensors is solved. The problem is known to be NP-complete. The sustainable design is improving an existing Iterative Target Oriented Algorithm (ITOA) to cover moving targets move randomly over a given area of deployment starting from entry points reaching to exit ones in a realistic simulation. To evaluate the performance of the modified algorithm, a comparison is provided with three existing algorithms (Iterative centralized Greedy Algorithm (ICGA), Iterative Centralized Forced-directed Algorithm ICFA, and Iterative Target Oriented Algorithm ITOA). Simulation results revealed that the sustainable scheme can find a disjoint set with a minimum number of sensors covers the maximum number of moving targets in an energy-efficient way and extended network lifetime

This research study examines the practicability of using micro and nano size silica to improve the asphalt characteristics. Asphalt cement penetration grade of (60 /70) was prepared using (0%, 2%, 4% and 6%) of silica filler by weight of asphalt and investigated in terms of the softening point, penetration, and penetration index, viscosity, and ductility values. To modify the asphalt binder, the silica powder was mixed by a mechanical blender set at (2000) rpm at a mixing temperature of 140°C. However, the main challenge is an agglomeration of nano-silica powder which can reduce the ductility of nano silica modified binder. Therefore, this paper studies the efficiency of mixing period to obtain a homogeneous composite binder while alleviating the agglomeration issue. To do so, the effect of periods of mixing ranged between (30 to 60) minutes were examined on characteristics of modified asphalt binders. Overall, the addition of silica filler has an encouraging impact on the asphalt binder rheological properties. Also, the ductility value decreases with the addition of nano-silica content, attributed to the huge surface area and degree of agglomeration. Furthermore, results exhibited that 6% of micro silica powder and 4 % of nano silica powder were reasonable to develop the rheological properties

In this paper, Analysis Of Variance (ANOVA), Artificial Neural Network (ANN), and Genetic Algorithm (GA) have been studied to predict the effect of milling parameters on the Surface Roughness (Ra) during machining of mild steel alloy. The milling experiments carried out based on the Taguchi design of experiments method using (L16) orthogonal array with 3 factors and 4 levels. The influence of three independent variables such as spindle speed (910, 930, 960, and 1000 rpm), feed rate (93, 95, 98, and 102 mm/min), and Tool Diameter (8, 10, 12, and 14 mm) on the Surface Roughness (Ra) were tested and analyzed with (ANOVA) to predict the response which indicates that spindle speed was the most significant factor effecting on Surface Roughness (Ra). Artificial Neural Network (ANN) and numerical methods are used widely for modeling and predict the performance of manufacturing technologies. Neural Network technique with 2 hidden layers, 10 neurons size, 1000 epochs, and Trainlm transfer function is used to predict the result. The Genetic Algorithm (GA) has been utilized to find optimal cutting conditions during a milling process.
From the results, the optimal value of spindle speed is (930 rpm), feed-rate is (95 mm/min) and tool diameter is (8 mm). This network structure is capable of predicting the Surface Roughness (Ra) well to optimize the milling parameters. Artificial Neural Network (ANN) predicted results indicate good agreement between the experimental and the

The Electro discharge machine that named (EDM) is used to remove the metal from the workpiece by spark erosion. The work of this machining depends on the multiple variables. One of the most influential variants of this machine is the polarity, the material of the electrode, the current and the time pulses. Essentially the polarity of the tool (electrode) positive and the work piece is negative, this polarity can be reversed in this paper was reversed the polarity that was made the tool (electrode) negative and the work piece was positive. The aim of this paper was focused on the influence of reversed the polarity (negative) with changing the electrode metal (copper and graphite) on the surface roughness and metal removal rate by using different parameters (current and pulses of time). Experiments show that: the copper electrode gives (best surface roughness 0.46 μm when the current 5 Am and Ton 5.5 μs) and (worst surface roughness 1.66 μm when the current is 8 A and Ton 25 μs). And give (best values of the MRR 0.00291 g/min when the current is 8 and Ton 25 μs) and (The lowest values of MRR (0.00054 g/min when current is 5 and Ton 5.5 μs). The graphite electrode gives (best surface roughness 2.07 μm when the current 5 Am and Ton 5.5 μs) and (worst surface roughness 4.17 μm when the current is 8 A and Ton 25 μs). And give (best values of the MRR 0.05823 g/min when the current is 8 and Ton 25 μs) and (The lowest values of MRR (0.00394 g/min when current is 5 and Ton 5.5 μs).

RS (residual stresses) represent the main role in the performance of structures and machined parts. The main objective of this paper is to investigate the effect of feed rate with constant cutting speed and depth of cut on residual stresses in orthogonal cutting, using Tungsten carbide cutting tools when machining AISI 316 in turning operation. AISI 316 stainless steel was selected in experiments since it is used in many important industries such as chemical, petrochemical industries, power generation, electrical engineering, food and beverage industry. Four feed rates were selected (0.228, 0.16, 0.08 and 0.065) mm/rev when cutting speed is constant 71 mm/min and depth of cutting 2 mm. The experimental results of residual stresses were (-15.75, 12.84, 64.9, 37.74) MPa and the numerical results of residual stresses were (-15, 12, 59, and 37) MPa. The best value of residual stresses is (-15.75 and -15) MPa when it is in a compressive way. The results showed that the percentage error between numerical by using (ABAQUS/ CAE ver. 2017) and experimental work measured by X-ray diffraction is range (2-15) %.

An extended meshless method that relying upon Galerkin formulation is applied on the crack analysis of orthotropic functionally graded Brazilian disc. Weak form is involved to solve the governing equation in the numerical method. In addition, enrichment terms and sub-triangle techniques are applied to improve the accuracy of relevant results. This paper depicts the influence of variation in the crack stretch and non-homogeneity parameters on the values of stress intensity factors using a developed MATLAB program. In the isotropic case, it is clear that when the length of crack increases, SIF increases. Graduation in has more effect in increasing the values of SIF in corresponding increased crack length. The verification has been checked by changing the range of the J-integral domain and variation of the support domain.

In this paper, the control approach is used for achieving the desired performance and stability of the twin-rotor MIMO system. This system is considered one of the complex multiple inputs of multiple-output systems. The complexity because of the high nonlinearity, significant cross-coupling and parameter uncertainty makes the control of such systems is a very challenging task. The dynamic of the Twin Rotor MIMO System (TRMS) is the same as that in helicopters in many aspects. The Quantitative Feedback Theory (QFT) controller is added to the control to enhance the control algorithm and to satisfy a more desirable performance. QFT is one of the frequency domain techniques that is used to achieve a desirable robust control in presence of system parameters variation. Therefore, a combination between control and QFT is presented in this paper to give a new efficient control algorithm. On the other hand, to obtain the optimal values of the controller parameters, Particle Swarm Optimization (PSO) which is one of the powerful optimization methods is used. The results show that the proposed quantitative control can achieve more desirable performance in comparison to control especially in attenuating the cross-coupling and eliminating the steady-state error.