Engineering and Technology Journal

Mesoporous silica SBA-15 material was synthesized and functionalized by post synthesis method with amino functional group (3-aminopropyltriethoxysilane) to investigate its potential use as an adsorbent for cobalt (Co(II)) removal from aqueous solution. Several characterization methods were used for identifying the material characteristics before and after functionalization, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Batch adsorption experiments were conducted and different variables that affected the removal of cobalt ions were studied, such as pH (1-6), contact time (0-150min), initial concentration (20-120mg/L) and adsorbent dose (0.025-0.3g). It was found that amino functional group was very effective in increasing the percentage removal of (Co(II)) as compared with non-functionalized SBA-15. The percentage removal of these ions were increased with the increasing of pH (up to 5), contact time and NH2-SBA-15 dose, while the increase of the initial concentration of Co(II) ions led to decrease in it.

The present paper investigates experimentally the impacts of fiber layer orientation on the structural behavior of CFRP strengthened steel-plated girders that are subjected to shear. Three of these girders were considered strengthened girders whereas the last one represents the reference girder. Each of the four steel-plated girders was tested aside and in different periods of time using the shear buckling test. A point load was applied to the center of the top flange of the four girders using Avery hydraulic machine. A laminated carbon fiber reinforced polymer sheet (CFRP) was fully adhesively attached to the web area of the three girders. The attached carbon fiber sheet took different patterns: either on one side or on both sides. Such a step helps to evaluate the most effective strengthening technique of each of the girders using CFRP composite. To check the behavior and the increase in the ultimate shear capacity of the girders, several parameters were examined. Results have revealed that both the unstrengthen and strengthened girders of different orientations of CFRP showed a similar stiffness behavior at a relatively low load levels. However, when the load is increased, the stiffness behavior significantly is increased in the three strengthened girders, compared to the strengthened girders. It has further shown that the ultimate shear load of the three strengthened girders were higher than that of the reference girder. Such a result can clearly be exemplified by the obtained ranges: 19.56% and 25% depending on the orientation of the CFRP laminates. Following Von Mises stresses, the researcher was able to predict the ultimate shear load of the four girders and to figure out the arrived at results from the four experimental tests.

In the present research, investigate the effect of adding some reinforcing materials which include nano-aluminum oxide (nano-Al2O3) particles that added with different volume fractions of (1%, 2%, 3% and 4%), and random fiber glass that added with fix volume fractions of (4%), into the PMMA matrix as new cold cure resin, and study some mechanical and physical properties of these hybrid laminated composite as prosthesis denture base material. Specimens’ of this project were prepared by using (Hand Lay-Up) method to form a hybrid laminated composites materials. The mechanical tests were performed on these specimens include (tensile test, impact test, flexural test and hardness test), while the physical test was thermal behavior test. Results of this study showed the values of (tensile strength, hardness, thermal conductivity and thermal diffusivity) properties increased when adding the (nano-Al2O3) particles in PMMA composite materials for prosthetic denture base materials. While, the values of impact strength and flexural strength properties were decreased.

OFDM has high spectral Performance and pliability in multipath channel effects while MIMO use another strategy for saving power of transmitter by using multi in multi out antennas to make throughput processing in high efficiency. The transceiver MIMO OFDM implemented on an FPGA typeSpartan3 XC3S200 with proper algorithm, Invoke method and QPSK modulation. The project prospective to improve the transceiver operations in terms of data transmission in high speed and saving power for wireless communication system take in consideration the cost of implementation hardware. In the result registered throughput data rate 425 Mbps using spatial algorithm (ICA with SD algorithm) with another advantage reduction in PAR by 6db and BER less than 10-7).The total architecture using 61% slice registers, LUT's of 55% and memory about 67% on board of Spartan-3 XC3S200.

This paper suggests a flexible joint robot operated by brushed Direct Current (DC) motor model. Due to complex high-order, nonlinear dynamical system which operating under parameter’s uncertainty, sliding mode control (SMC) used to solve this problem of control the flexible joint robot. The SMC method is identified as one of the effective method to design robust control for the flexible joint robot, which based on t using a Low Pass Filter (LPF) with suitable time constant. The mathematical model is presented clearly and the simulations together with their analysis are done using MATLAB software. Simulation results display the efficacy of the designed robust control in stabilizing the system states and forcing the link side angle to converge to the desired value with appropriate control effort.

In this work Corrosion buckling interaction behavior of AISI 304 stainless steel circular columns was investigated. Long and intermediate columns diameter of (6 mm) are tested in as received and corroded condition. Corroded columns are tested after embedded it in soil for different times. Rotating buckling machine test was used to evaluate the critical buckling load (pcr) under dynamic compression loads. By using Perry Robertson formula, experimental work results are compared. The results showed that increasing in corrosion time (embedding time), the reduction in critical buckling load increases also. Maximum reduction of buckling load value are (2.28%, 1.37%) for long and intermediate column respectively as compared with as received condition.

A knowledge of the concrete vibration after casting have led to improve the mechanical properties of concrete, reduce the deformations due to creep and shrinkage and reduce the concrete permeability. At the Structural and Material Laboratories- Building and Construction Engineering Department, University of Technology, series experimental tests on prisms, cubes and cylinders were carried out to investigate the effect of waiting time after initial vibration on the flexural-tensile strength, compressive strength and splitting tensile strength of fiber reinforced concrete. The variables considered in this study were; the amount of steel fiber and waiting time after initial vibration. The test results showed that the concrete prisms without steel fiber show approximately linear behavior till the maximum flexural-tensile load due to brittle behavior of concrete. The maximum improvement in flexural-tensile strength of concrete prism occurs after the initial setting of concrete i.e after 90 minutes of waiting time. The re-vibration after time period increase the stiffness of concrete prism in case of presence of steel fiber compared with the prisms initially vibrated only. The modulus of rupture of concrete prism increased with the increasing of steel fiber content for all waiting time before re-vibration.

An alternative to traditional Pseudo-Noise (PN)-Sequences, one-dimension (1D) orthogonal chaotic map sequences, and three dimensional (3D) continuous chaotic systems (x,y,z) are generated by orthonormal Gram-Schmidt process. A new Orthogonal Chua Chaotic Sequences OCCSs-based Direct-Sequence/Spread-Spectrum-Code Division Multiple Access (DS/SS-CDMA) system is proposed. The proposed system combines the 3D Chua chaotic system with Real Orthogonal Matrix Approach (ROMA). Comparing to previous sequences, the OCCSs inherit all beneficial features of Chua's Circuit and ROMA scheme, such as the best correlation properties, higher capacity, Low Probability Interception (LPI), reliable security and good orthogonality. The three analytical Bit Error Rates (BERs) expressions for each orthogonal sequence ̂ ̂ ̂ of OCCSs with three fingers Rake receiver under three-path Rayleigh fading channel with their spreading delays are derived. The correlation properties, capacity, randomness and security of OCCSs are evaluated. The simulations results show that the overall BERs performances, capacity, and security of proposed ̂ ̂ of OCCSs-based DS/SS-CDMA system outperform classical PN , 1D Logistic Map sequences and sequences of 3D Chua’s circuit generated by orthonormal Gram-Schmidt process. The results also showed that at BER 10-4 for single and multi-user transmissions, the proposed OCCSs ̂ has achieved gains of 5 and 4 dB respectively in signal-to-noise (SNR) over traditional DS/SS-CDMA based on other sequences in Rayleigh fading channel.

In this research, a multi-response optimization based on Taguchi method-based MOORA (Multi-response optimization based on ratio analysis) is proposed for carburization process of low carbon steel. Experiments were designed using (Taguchi’s) method with six input carburization factors (carburization temperature, carburization time, tempering temperature, tempering time, activator wt.%, and quench media). Depth case and wear rate were considered as the most response measures in this study. Results of the analysis shows that the carburization temperature is the most significant variables for the optimum outcome results. The desired response measures and mathematical model were achieved and used as optimum condition tool. The outcome of this study had been explored the possible use of the developed carburized steel in high wear resistance applications.

Due to the complexity of the gas detection process, traditional modeling techniques cannot provide accurate modeling performance to reproduce the behavior of this difficult process. In this paper, an intelligent modeling technique is utilized to develop an accurate model to represent the complex and nonlinear gas detection process. In particular, in this study nickel Oxide NiO gas sensor, which was specifically fabricated by a simple chemical spray pyrolysis technique. In the process, the nickel chloride hexahydrate salt was used at a concentration of (0.05 M) and a temperature of 350 ºC. Because of this process, the thickness of NiO was 0.1μm. Inspection was done using three different testing techniques; X-ray diffraction, scanning electron microscopy, and the sensitivity test of NiO for Methane gas CH4 in the range of (0-500) ppmv. Inspection results show that the film was crystalline, has a cubic system, and without cracks or open pores. On the other hand, the sensitivity results were disparate and low in value within the considered range. From the real-time experiment described above, training samples were gathered to develop the desired process model. The considered modeling technique was based on exploiting the wavelet network (wavenet) to represent the nonlinear function of the nonlinear autoregressive with exogenous input (NARX) structure. In model development process, the experimental data were utilized as the training samples for the wavenet-based NARX model. As the modeling accuracy, the proposed wavenet-based NARX model attained a value of 1.895 × 10-12 for the root mean square of error (RMSE) criterion.

This paper presents a Self-Recurrent Wavelet Neural Network (SRWNN)-based Internal Model Control (IMC) for nonlinear systems. As the internal model, a Nonlinear Autoregressive Moving Average (NARMA-L2) is employed for obtaining a forward system model. Then, this model is directly used to formulate the control law. The proposed SRWNN-based IMC is an enhanced version of a previously published Wavelet Neural Network (WNN)-based IMC scheme. Particularly, the enhancement was attained by considering three modifications, which include the use of an initialization phase for the parameters of the wavelon layer, the utilization of self-feedback connections in the wavelon layer, and the exploitation of RASP1 as the mother wavelet function. The modified Micro Artificial Immune System (modified Micro-AIS) is employed as the training method. From the simulation results, the efficiency of the suggested methodology have been proved concerning control precision and disturbance rejection ability. Moreover, the superiority of the SRWNN over the WNN and the Multilayer Perceptron (MLP) as the IMC controllers has been confirmed from a comparative study. Furthermore, the modified Micro-AIS has accomplished better results compared to the Genetic Algorithm (GA) concerning control precision.

The aim of this work is generated a Nano materials having good mechanical properties for 6061AA-alloy.Fivewt% of Nano particles (Al2O3) (20-30nm grain size) were adoptees (1, 1.5, 2, 2.5 and 3wt% AL2O3).The Nano composites were manufactured by stir casting technique. The mechanical properties of Nano composites were obtained at room temperature and was found that the matrix hardness is improved by 35.36%, matrix ultimate by107%, yield by36.84% and ductility by 12% at 1.5wt% AL2O3.Also it was obtained that all the mechanical properties of the Nano composites are higher than that of metal matrix. The above improvements are due to less porosity, high uniform distribution and good bounding between metal matrix and Al2O3.

In this paper, theoretical and experimental study of the performance enhancement of PV panels has been presented by utilizing fins for cooling module’s temperature at climate conditions operation. To satisfactory cool off for the solar panel as a passive technique, heat sink which has a rectangular variable cross section fins (ribs) attached on the back side of the panel. Analytical thermal model is formulated for heat dissipation from heat sink in order to predict PV panel temperature. A comparison between experimental and theoretical results was carried out for solar panels without and with fins, in order to investigate the proposed thermal model and study the effect of operating temperature on the power output from the panel. The results shows that using fin cooling technique causes a significant dropped in average solar panel temperature about 5.7°C and an enhancement in the average of module output power about 15.3%.

Decision tree algorithms are famous method in inductive learning and successfully applied for model classification and prediction. Performance evaluation in organization is one of the most important issues that are reliable due to the transition from industrial to knowledge age. This paper proposes the use of modified ID3 (Interactive Dichotomiser 3) decision tree algorithm combining with Taneja entropy instead of the original ID3 algorithm that depends on Shannon entropy which is widely used in the information theory. In fact, the original ID3 was suffer from complexity in the form of complex tree with large number of hops and nodes. The information gain was used as a splitting criteria of the modified ID3. The proposed modified ID3 algorithm has been tested on a dataset for a different university employees with several attributes that directly affect their annual performance assessment. The most optimized tree is constructed by taking one attribute that have the largest information gain from the dataset as a root of tree and repeating the process until the tree is completed. The results showed that the proposed modified ID3 decision tree algorithm that based on Taneja entropy gives less complexity due to small tree with three nodes and two to one hope to reach the right decision.

The aim of the presents study was to investigates the influence of different sliding velocity 1.4, 2.8, 4.2 m/sec, applied load 5, 10, N and time 10, 20, 30 min on wear rate of Al-Mg-Si alloy reinforced with varying weight fraction of TiO₂/SiC 1.5:0 ,3:0 , 4.5:0 , 0:1.5 , 0:3 , 0:4.5 , 1.5:1.5 , 3:3 , 4.5:4.5 wt.% with the same particle size (>75μm) by using pin-on-disk techniques. In this research Al-Mg-Si alloy TiO₂/SiC hybrid composites was prepared by vortex technique. The primary objective is to use taguchi method for predicting the better parameter that give the highest wear resistance. A L9 orthogonal array was selected for each present to analysis of data and use ANOVA to determine parameters significantly influencing the wear rate of hybrid composite. Optical microscope and SEM with EDS examination were utilized to study the worn surface. The experimental and analytical results showed that the taguchi method was successful in predicting the parameters that give the highest properties and the volume fraction was the most influential parameter on the wear rate. The results demonstrated that when the applied load and time increased the wear rate increasing, but when the sliding velocity increased the wear rate decreasing and showed the minimum wear in hybrid composite with 4.5% reinforcement this observed with highest ratio of S/N 156.787.