ISSN: 1999-8716

Issue 3,

Issue 3


The Effect of Infill Steel Plate Thickness on the Cycle Behavior of Steel Plate Shear Walls

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 1-6

Steel plate shear wall (SPSW) is commonly used in civil schemes because of its good deformability and stiffness. In this research, the numerical analysis of steel plate shear wall (SPSW) with unstiffened infill steel plate is conducted. This paper explains the effect of thickness variation of infill steel plate on behavior of steel plate. In this status, several samples are designed and checked by rigid frame and actuator. The experimental samples is joined to a rigid frame. 3 numerical specimens consist of steel plate shear wall with different thickness (1.5, 3, 4. 5) mm formed by finite element code which is advanced by the Amirkabir university. To confirm the model, numerical results were discussed with a valid experiment which explain suitable agreement. Numerical model tested under cyclic loading with frequency of 1/60 Hz. Results show that the increase of infill steel plate thickness enhance stiffness and ductility ratio of model. And so, would decrease energy absorption in comparison with the reference model.

Experimental Study of Hydraulic Jump in Adverse Stilling Basin at Smooth Bed

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 7-13

The effect of changing in the bed slope of stilling basins produces changing in characteristics of the hydraulic jump such as sequent depth ratio, length of jump ratio, length of the roller and energy dissipation ratio, consequently the dimensions of stilling basin changed. In this study hydraulic jump investigated on smooth bed (without any appurtenances) for three adverse slopes (- 0.03, - 0.045, - 0.06) in addition to horizontal bed slope, the experiments were applied for the range of Froude number (Fr1) between 3.99 and 7.48. The results showed a reduction about10 % in sequent depth ratio, 22.1 % in length of jump ratio, 20.51 % in length of roller ratio and 13.87% in the energy dissipation ratio when the adverse slope (- 0.06) used instead of horizontal bed for the same Froude numbers. Empirical equations for the sequent depth ratio, length of roller ratio and the energy dissipation ratio were obtained from the experimental data.

Performance of Various Electrical Resistivity Configurations for Detecting Buried Tunnels Using 2D Electrical Resistivity Tomography Modelling

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 14-21

This work aims to evaluate performance of 2D electrical resistivity modelling technique for detecting buried tunnels using various electrode configurations. A synthetic resistivity model was designed to explore the capability of Wenner, Wenner- Schlumberger, Dipole-Dipole, Pole-Dipole and Pole-Pole electrode configurations for detecting buried tunnels at different noise levels. 2D forward modelling (RES2DMOD) and 2D inversion (RES2DINV) software were implemented using blocky L1 norm optimization method. The results showed that the modelled tunnel can clearly be detected at 0% noise level due to the high resistivity contrast between the synthetic tunnel and the surrounding host materials. At 0-30% noise levels, the results indicated that dipole-dipole and Wenner- Schlumberger in the second order perform better than other configurations. This can be attributed to the characteristics features and sensitivity of these configurations for resolving the subsurface resistivity changes. It is suggested that these configurations are more suitable for detecting the buried structures. The results also showed that the inversion artifacts caused by high noise levels may smear the resistivity signature of the burred targets for particular configurations. Thus, obtaining high quality data ensures reliable resistivity interpretations. The study demonstrated the usefulness of the 2D numerical modelling for planning of electrical resistivity surveys.

Optimization of Sodium Bicarbonate Production Using Response Surface Methodology (RSM)

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 22-28

The main objective of this study was to evaluate the use of batch bubble column to produce high particle size (>300 micron) of sodium bicarbonate product to improve filtration and drying operations in the production process. Lab scale batch bubble column of 80 mm diameter and 0.5 m height was used to study the process for sodium bicarbonate production using 20% sodium carbonate solution as a starting solution. Three operating variables were considered, CO2 gas content (20-100 %), temperature (30-70 oC) and time (0.5-2.5 h). The bicarbonate yield and crystals size were considered to be the objective variables of the process. Response surface methodology (RSM) was used with central composite design (CCD) of experiments. Empirical polynomial multivariable equations were obtained. The reaction time was found to be the most effective operating condition on the yield of sodium bicarbonate, and temperature was found to be the most effective operating condition on crystal size of sodium bicarbonate. The optimum conditions achieved 400 microns particle size at temperature 70 oC and time 2.5 h. Kinetics study of the process showed that zero order reaction with both sodium carbonate and CO2 concentrations was approximately fitted the experimental data, useful for shortcut process design purposes.

Design and Implementation of Infrared (IR) Communication System

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 29-33

Wireless Infrared (IR) communications system is meant to use free-space propagation of light waves as a transmission medium in near infrared band. In this paper, voice communication system is simulated and implemented by protues software using IR as a source that is established an audio communication (link to transmit and receive voices and music via infrared light). The outcome of this proposed work is to design and implementation an optical wireless system to transmit voice over a certain distance in laboratory. This system has many advantages such as is a common, inexpensive, and the transmitter or receiver can be showed to another location with least distraction.

Flexural Behavior of High Strength Concrete Incorporated Super Absorbent Polymer (SAP)

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 34-38

This research include the study of flexural behavior of reinforced concrete beams with and without addition of super absorbent polymer (SAP) to concrete, two groups of concrete mixture were used; each one have five concrete mixture (Reactive Powder Concrete RPC, Modified Reactive Powder Concrete, Self Compact Concrete SCC, High Strength Concrete HSC and Normal Strength Concrete NSC) four of them with high compressive strength and the last one with normal compressive strength. Group A casting concrete without addition of SAP, group B casting concrete with addition of SAP. Ten beams are molded of (200*300*1700) mm dimension with same steel reinforcement. Flexural tested for all beams was doing and load-deflection relationships of beams with and without SAP were established. Test results had shown that beams casting with addition of SAP (group B) proved to have larger load carrying capacity and llower deflection compared with group A.

Modeling and Optimization on the Carbon Dioxide Separation from Natural Gas Using Hydrotalcite-Silica Membrane

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 39-46

The process modeling and optimization of carbon dioxide (CO2) separation from carbon dioxide-methane (CH4) binary gas mixture through hydrotalcite (HT)-silica membrane using statistical design of experiments (DoE) is reported in this study. The effect of three important process variables, pressure difference across the membrane (100-500 kPa), temperature (30-190oC) and CO2 feed concentration (10-50%) on the CO2 separation performance of the membrane were investigated. The response surface methodology (RSM) coupled with central composite design (CCD) was used to build up two models to correlate the effect of process conditions to CO2 permeance and CO2/CH4 separation selectivity. The analysis of variance (ANOVA) of the quadratic model at 95% confidence interval confirmed that the model was highly significant. The CO2 feed concentration with 43% showed the best performance with a CO2 permeance of 6.0x10-7 mol.m-2.s-1.Pa-1 and a CO2/CH4 separation selectivity of 109 at 100 kPa pressure difference across the membrane and temperature of 30oC.

Hydrotalcite; porous membrane; carbon dioxide capture; response surface methodology.

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 47-53

Various protection methods can be used for protecting the pipeline system from the impact of water hammer. Which includes the use of special materials for supporting the pipeline and the installation of special devices such as surge tanks, relief valves, and air chambers. In this study, to protect the pipeline system and reduce the effect of water hammer, surge tank has been used. Governing equations of transient flow with and without surge tank is numerically simulated using MATLAB software. Sensitivity analysis was investigated using several variables such as pipe diameter, wave’s velocity and friction factor. Method of characteristics (MOC) was implemented in this study. It was found that the diameter and friction factor of pipe have a significant impact on the results of transient flow and surge tank compared to the effect of wave’s velocity. It has been reached that the capacities of surge tanks at diameter (1m), are (1475m3) at first, second and fourth stages, (1360m3) at third and fifth stages and (570m3) at sixth stage. And at diameter (1.2m), the capacities are (1700m3), (1530m3) and (1475m3) at first, second and third stages respectively. But at diameter (1.4m), the capacities are (1590m3) at first and second stages. For all values of wave’s velocity, the capacities of surge tanks are (1760m3), (1530m3) and (1420m3) at first, second and third stages respectively. But the capacities of surge tanks at friction factor (0.007) are (1810m3), (1585m3) and (1245m3) at first, second and third stages respectively. However, for the capacity of surge tanks at the friction factor (0.008), it was mentioned when the surge tanks capacity of the diameter (1.2m) was mentioned. And when the friction factor is (0.009), the capacities are (1460m3) at first stage, (1415m3) at second and third stages and (570m3) at fourth stage.

Investigation and Estimation of Seepage Discharge Through Homogenous Earth Dam with Core by Using SEEP/W Model and Artificial Neural Network

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 54-61

This paper concerns to investigate the amount of seepage through the homogenous earth dam with core by finite elements software SEEP/W.
By SEEP/W investigates groups were executed with three different upstream and down.stream slopes of earth dam, four different upstream and downstream slopes of core, for homogenous cases. For each run the amount of seepage discharge was specified. Dimensional analysis was used for the product and with aiding of the SPSS statically program to advancement an empirical equation in order to estimate the amount of seepage discharge through the homogenous earth dam with core resting on impervious base. In addition using ANN the SEEP/W results and the recommended equation in this paper have been verified, which show great agreement with SEEP/W results with using one hidden layer for ANN.

Effect of the Circular Perforations on the Heat Transfer Enhancement by the Forced Convection from the Rectangular Fins

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 62-70

This study aims to investigate the effect of the circular perforation of the rectangular fin on the enhancement of the heat transfer by forced convection. The solid rectangular fin considered as a reference for comparison purpose with the perforated fin. The parameters taken into consideration are thermal properties and geometrical dimensions of the fin and its perforations. The area and heat transfer gain of the perforations fins were considered being the main parameters in this study. The results of this study showed that the heat dissipation was improved when used the perforation fins compared with the equivalent solid fin. The enhancement quantity of the heat dissipation from the fin depends on the thermal conductivity, the perforation dimension, thickness, longitudinal and lateral spacing. Finally, the perforating of the fins enhances the rate of heat dissipation as well as decreases the weight of the fin.

Adaptive Inverse Neural Network Based DC Motor Speed and Position Control Using FPGA

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 71-78

In this research two types of controllers are designed in order to control the speed and position of DC motor. The first one is a conventional PID controller and the other is an intelligent Neural Network (NN) controller that generate a control signal DC motor. Due to nonlinear parameters and movable laborers such saturation and change in load a conventional PID controller is not efficient in such application; therefore neural controller is proposed in order to decreasing the effect of these parameter and improve system performance. The proposed intelligent NN controller is adaptive inverse neural network controller designed and implemented on Field Programmable Gate Array (FPGA) board. This NN is trained by Levenberg-Marquardt back propagation algorithm. After implementation on FPGA, the response appear completely the same as simulation response before implementation that mean the controller based on FPGA is very nigh to software designed controller. The controllers designed by both m-file and Simulink in MATLAB R2012a version 7.14.0.

Measurements of Corona Discharge in Sharp –to-Plane Electrodes Configuration

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 11, Issue 3, Pages 79-84

A Dc positive sharp- to –plane Corona phenomena have been studied in electronegative gases (air ,and SF6 ) for pressure up to (3.2bar and gap length from 0.1 to 0.5 cm), with high degree of non-uniformity electric field. The corona –breakdown phases can exhibit anomalous characteristics. The exact physical process of such phenomena is not yet fully understood complete. To better understand this process precise knowledge about corona and spark discharge is necessary. Hence the dependency of corona inception and spark breakdown voltage on the pressure, non-uniformity field factor and the type of applied voltage ,also the type of materials.
The steady region of corona discharge is observed in the ( sharp- to- plane ), for applied voltage between the threshold value voltage and onset value , we observe an effect that attaching gases. A Townsend type of discharge develops in the region close to point. At voltages above the onset value , the burst pulses are replaced by a Dc current ,and in some cases 'pre-breakdown ' streamer are also observed.