Journal of Engineering and Sustainable Development (JEASD)

This paper describes the geotechnical characteristic of soil located at Al-Emara city southern Iraq. The paper presents the data advanced from the field investigations performed at many projects at Al-Emara city. The ground conditions in the study area indicate that there is a deep layer (36m) deep consisting of different soils. Namely, the records of boring exploration include the results of laboratory tests on samples taken from the site in addition to the results of field tests such as cone penetration tests, standard penetration tests. According to the test results and soil profiles, the stratification of layers was described for each borehole according to the test results. The paper aims at determination of mathematical correlations among the soil parameters determined from the laboratory and field tests from these relationships, several correlations were obtained from which prediction for geotechnical properties of various soils can be made. Several relationships were obtained from the field and laboratory properties of the soil, the plasticity index, the pre-consolidation pressure, cone penetration (cone resistance qc, friction sleeve fs) with depth. The relationships include the relation between the standard penetration test number (N60) and cone penetration resistance (qc) ,sleeve resistance (fs), the relation between cone penetration resistance (qc) and cohesion of soil (c) , the relation between cone penetration resistance (qc) and angle of shearing resistance (Ø),The relation between cone penetration resistance (qc) and undrained shear strength (cu). In addition the relationships include the relation between unconfined compressive strength (qu) and constrained modulus of elasticity (D).

In this research, the proposed antenna is a novel design made out of (Q- slot) that fed by step impedance micro strip line open mouth ended. The proposed antenna is intended to work at four bandwidth frequency groups meet the specifications of DO,1xRTT-3G (1xRTT is a data transmission system used on CDMA networks that allows for connection speeds of up to a theoretical limit of 144kbps), Wi-Fi-IEEE802.11e (local area wireless computer networking technology) and WiMAXIEEE802.16m (Worldwide Interoperability for Microwave Access) communications. The surface current distribution at resonant frequencies and the effect of varying the dimensions of parameters had been studied carefully in this research to enhanced the performance of resonant frequency. Also the radiation patterns in (E-plane) and (H-plane) for the antenna had been studied. This document is a live template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document. It should not exceed 200 words. It should briefly indicate the general scope and also state the main results obtained, methods used, the value of the work and the conclusions drawn. No figure numbers, table numbers, references or displayed mathematical expressions should be included.

In this work, a nonlinear integral controller is proposed for a Direct Current (DC) motor model in the presence of a variable and unknown external load and for a constant and variable reference velocity. The nonlinear integral term is designed simply by replacing the integral of the error function by the integral of a saturation error function to the error. By adjusting the saturation function parameters the proposed controller will have a robust properties against the uncertainty and the variation of unknown external torque. The numerical simulations explore the ability of the proposed controller in controlling the DC motor speed to a desired value for the constant and variable load and also for sinusoidal desired speed. In addition the results also compared with the classical integral controller to clarify the feature of the present controller.

High performance self-consolidating concrete HP-SCC is one of the most complex types of concrete which have the capacity to consolidated under its own weight, have excellent homogeneity and high durability. This study aims to focus on the possibility of using industrial by-products like Silica fumes SF in the preparation of HP-SCC enhanced with discrete steel fibers (DSF) and monofilament polypropylene fibers (PPF). From experimental results, it was found that using DSF with volume fraction of 0.50 %; a highly improvements were gained in the mechanical properties of HP-SCC. The compressive strength, splitting tensile strength, flexural strength and elastic modulus improved about 65.7 %, 70.5 %, 41.7 % and 80.3 % at 28 days age, respectively with retaining the main properties of HP-SCC. Furthermore, using PPF with volume fraction up to 0.10 %; an enhancement in the compressive and elastic modulus of HP-SCC about 47.4 % and 31 % was obtained at age of 28 days, respectively. Moreover, using PPF with volume fraction of 0.15 %, the splitting tensile strength and flexural strength of HP-SCC improved about 44.5 % and 20.3 %, respectively.

This work describes a research study for evaluating the durability performance of open-graded asphalt materials in terms of accelerated aging, moisture damage and permanent deformation. Such asphalt mixes have high porosity, which offers significantly better drainage properties than normal mix designs. However, these materials also exhibit poor durability and strength limiting their use in pavement application, to remedy this, fiber and/or polymer binder modifiers have been proposed. samples were prepared with and without the modifiers using Marshall mix procedures and slabs (approximately 1000 samples for Marshall test with 20 slabs for wheel track test (Dyna-Track) and were experimentally tested using various conditions ( short and long term aging ) and standardized testing procedures including wheel track test for rutting, falling-head test for permeability , cantabro abrasion test for particle loss resistance and indirect tensile test for strength. In general, the results indicate that the introduction of fiber modifiers leads to minor improvement in strength characteristics of the samples, while contributing to significant reduction in permeability. On the other hand, the introduction of polymer modifiers nearly doubled both the strength and permeability and also increased the air voids.

A foam composite material was set by adding polypropylene fibers diameter of 18 μm and 6 and 12 mm length to rigid polyurethane foam with a weight fraction of (2.5-15 )%wt. The results had shown improvement on (flexural strength, compressive strength, hardness, impact strength) and increase in flexural modulus, density and water absorption, with decreases in thermal conductivity of the resultant foam composite as compared with neat rigid polyurethane foam.

In this study used a surface hardening processes by shot peening and laser shock peening to improve the mechanical properties of low-carbon steel (AISI 1010). Surface hardening operations, carried out on a sample fatigue attended according to the specifications (DIN 50113). The specimens subjected to the tensile test, Vickers hardness test and SEM examination for the microstructure of samples has been carried out to show the effect of surface hardening on the mechanical properties of fatigue and hardness. Results show an improvement in fatigue after the samples exposure for shot and shock peening, the samples which treated with laser shock peening have higher values of fatigue resisters and hardiness than sample treated with shot peening.

To accomplish a construction project successfully, it is important to manage the risk in terms of cost, time, and quality. Risks always exist in construction projects and often cause schedule delay or cost overrun. Risk management is a process which consists of identification of risks, assessment with qualitatively and quantitatively, response with a suitable method for handling and control risks. The aim of this paper is to identify top major of 50 risks by contractors, owners and engineers. Questionnaire surveys were used to collect data, based on a comprehensive assessment of the likelihood of occurrence and their impacts on the project objectives. Also the impact of risks on cost, time, and quality, on construction project were analyzed. Questionnaire distributed to stakeholders who are working in construction sector in Erbil City during 2014-2015, then analyzed statistically. The results of the questionnaire indicate that the most significant risks are: inability of owner to finance the project, awarding the design to unqualified designers, poor qualifications, skills & experience of contractor and technical staff, design errors or defective design, poor qualifications and supervision of owner’s engineer, and long wait for approval of tests and inspection.

The study coversthe dynamic impact response of nanocomposite Alumina and nanocomposite carbon black particlesCB N220/Epoxy at room temperatures and 150 ℃at five velocities (16.58, 18.24, 19.88, 21.54 and 23.2) m/s by using a Hopkinson Split compressive Bar (HSPB).The nanocomposites samples with (2wt. % and 4 wt. %) of (Alumina and CB N220) were prepared without and with (25%) of unidirectional fiber glass. The results indicated that, maximum stress, strain and absorbed energy increased with increasing the strain rate for all types of these samples at room temperature. When increase the temperature to 150 ℃ it noted that the all values of stress, strain, strain rate and absorbed energy decreased with respect the values at room temperature. The determined Johnson-Cook parameters were found as the empirical fitting for data of stress (temperature, strain, and strain rate) with the curves of stress-strain, that are obtained from the compression tests.

Switched-capacitor (SC) based step down voltage dc-dc converter can be used for efficient power conversion when inductors are not used in order to reduce size and cost. In addition, switched capacitor dc-dc converters are superior to inductor –based converters for high-conversion ratio and wide range of load variation. In this paper, a multistage current - controlled switched - capacitor step down dc-dc converter is analyzed, designed and simulated. The converter features are good regulation capability and continuous input current waveform when two step-down converter cells are connected in parallel and operating them in antiphase. Classical SC converter with pulse width modulation technique is also analyzed, designed and simulated. For the PWM converter and current- controlled converter, third – order state-space averaging method is used for analysis. A fuzzy logic controller is used with the current– controlled converter to obtain fast dynamic response, low ripple in the output voltage and robustness against load and supply variations. A 70W, 48/12V converters are designed and simulated and Matlab/Simulink is used for simulation.

The effect of oxygen enrichment on the laminar flame speed of (butane – oxygen – nitrogen) premixed mixture. The measurement system is designed to measure the laminar flame speed using a tube – method and optical technique (photodiode).The laminar flame speed results were obtained at atmospheric pressure, initial temperature 301K, three level of oxygen concentration (0.21, 0.23 & 0.25) and equivalence ratio ( 0.6 – 1.4 ). All the measurements were carried out at pre-pressure period to use “density ratio method” for the calculation of laminar burning velocity. The adiabatic flame temperature, flame thickness and Zel’dovich number have been calculated theoretically. Validation of experimental work is approved by comparison measured values of laminar burning velocity for (butane – air) mixtures with the available published data. Good agreements are obtained in its comparison with the literature results employed in the present work are successful and precise.

In recent years, wind turbines have become an acceptable alternative for electrical energy generation, because of the environmental and economic benefitsof it. Much research remains to improve wind turbines behavior and make them more reliable and profitable. The reason for study application of wind turbine power quality characteristicsdetermine the impact of wind turbines on voltage quality. This paper gives a brief description of the impact that wind turbines may have on the voltage quality whichexplained through a case studyof(16 x 750 kW)wind farm on a (30 kV)distribution feeder.The case that have been studied shows thatpossible voltage quality problems can managed to overcome themby selecting an appropriate wind turbine type andby adjusting wind turbine control parameters.The reactive power demand forthe generator of windturbines is compensated using uncontrollable capacitorbanks and control Static Var Compensation (SVC) in flexible ac transmission system (FACTS) devices. This paper utilized the MATLAB/SIMULINK software in the modeling of such a wind squirrel-cage induction generator with grid in power system in two cases,fixed speed with directly grid connected squirrel-cage induction generator and variable speed with squirrel-cage induction generator. This model allows for the addition of wind energy generators togrid with wind turbineof (12 MW).The results obtained from our model in the case of constant wind speed using SVC showed the improvement in the value of Bas-Bar2(Vabc.B.B2)from (0.9 p.u) to (1 p.u) and reducing the reactive power value of Bas-Bar2 (Q..B.B2) from (8 Mvar) to (2 Mvar).

In this work, elbow orthosis which represents one of the upper extremity orthosis is manufactured from two layers of polypropylene reinforced by a sheet of carbon fiber between them to construct a new composite material called "PCP" material. More flexibility is gained by minimization of the modulus of elasticity of polypropylene-carbon fiber- polypropylene to about 3.5 against old material. Average pressure is measured between the patient's arm and bicep part of elbow using a portable pressure device (has mat of sensors) which reach to about 217kPa. ANSYS PACKAGE version 11 is used for numerical analysis the bicep part of elbow by using the estimated internal pressure to investigate deformation and to determine the Von – Misses stress. The investigated numerical results showed that the new material maximizes the deformation to about 280% (still in elastic region) and make the design more safe by increasing the factor of safety more than 4 % against polypropylene material. Mechanical properties are measured also in present work by carrying out the tensile test for the two materials under study to conclude finally that, the sheet of carbon fiber which is added has increased the mechanical properties to about 8.25 % and 248 % for yield and ultimate stresses, respectively.

Energy consumption is the most important issue in the design of Wireless Sensor Networks (WSNs). This paper analyzed the performance of Stable Election Protocol (SEP) and Extension of StableElection Protocol (SEP-E), in term of total energy consumption as a heterogeneous networks. Based onthe calculation of total energy for such protocols new equations are derived to calculate the averageenergy for each protocol. A homogeneous network with same parameters of SEP and SEP-E, equalnumber of nodes and the initial value of energy is equal to the calculated average value is proposed.Simulations are applied using Matlab Package to compare the performances of heterogeneous networkswith the proposal homogeneous network. The results showed that the performance of proposed network isout performed each SEP and SEP-E by relative amount of rounds. On the other hand, the extra amount oftotal energy of heterogeneous networks is assumed as extra number of nodes for proposed network. Theextra nodes are assumed as sleeping nodes for such network and simulation is applied.

A new equation has been derived using energy technique (dummy load method) to describe the buckling behavior of intermediate and long columns under dynamic buckling loads compression load and under dynamic combined load with consider of the initial imperfections of the columns and the effect of eccentricity. The results of this equation are compared with the experimentally results of 40 specimens of AISI 303 stainless steel intermediate and long columns tested under dynamic compression loading (compression and torsion) and under dynamic combined loading (compression, bending, and torsion) by using a rotating buckling test machine, and it be found that the derived equation may be used to predict of the theoretical critical buckling load Pcr under both dynamic compression and combined load with maximum percentage error is 19.3% and 16.8%, respectively.

This paper presents the contingency analysis to study the impact of forced or planned outageson electrical distribution system. The mathematical modeling of contingency analysis includes; the loadflow analysis and the power restoration analysis. The power restoration is formulated as a constrainedmulti-objective optimization problem, based on the ranking search method. The method performs loadflow simulations and utilizes the analytical information obtained to maximize the amount of total powerrestored and to minimize the number of required switching operations.In this work the contingencyanalysis is based on the advanced CYMDIST software as a tool for the simulation of a distributionnetwork and performing the required analysis. CYMDIST software is practical and efficient analysissoftware used by many electrical companies worldwide as well as by the Iraqi ministry of electricity.

The first of this paper, Caeser cipher is used to encrypt the fields in data base. The keys have been used from different lengths of fields, then applying affine algorithm. This is given a layer of security for data base. The cipher text is stored as a raw data in text file, which is separated between fields by Semicolon. The process is continued to end of records. The second part is creating a new Data Access Object(DAO), tables, records, fields, through counting a number of semicolon in a raw. The program keeps going until obtaining original records.

This paper is relevant with reinforced concrete beams subjected to combined torsional moments, bending moments and its comitant shear forces. Six identical beams in its dimensions and reinforcement, but different in the external loading setup were tested. The loading setup was applied in a manner depending on gradual ratio of bending moment to torsional moment; thereby, two beams were references to the other four ones. Experimental results revealed that, the loading setup is considerably effective factor on the structural behavior of the reinforced concrete beam. So that, through the loading setup, the presence of torsional moment leads to enhance the resistance of the beam over than 200% against combined loads than pure bending moment or torsional moment only. Also, the loading setup is capable of restoring the stiffness, maintaining the flexure mode of failure and raising the design safety factor for combined loaded reinforced concrete beams subjected to combined torsional moments, bending moments and shear forces.