Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Jadriyah, Baghdad
Iraq
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Email: joengbag@uobaghdad.edu.iq

Table of content: 2009 volume:15 issue:1

Article
The traditional solutions in the sustainable climatic adaptation and its employment in the contemporary housing
الحلول التقليدية في التكيف المناخي المستدام وتوظيفها في السكن المعاصر

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Abstract

Sustainability means, the integration between the ecological, technological, economical and social systems to forming the urban environment to maintain the resources for the future generations. Sustainability focuses on many principles: Using the natural energy, learning from the traditional architecture, minimizing the consumption of the resources. To develop some criteria's for contemporary dwellings in hot dry climate, the research tried to study and analyze the traditional architecture to diagnose its importance and ability to solve contemporary problems, one of which is the lack of comfortable and suitable dwelling units in hot dry climate regions. The research will study the traditional urban fabric components in the hot- arid zone, because the urban experiment in this zone emphasized on the compact forms and considered it the result of the human adaptation to create the comfortable microclimate. The research concludes the effective indicators in the traditional urban fabric and employed it in many of housing clusters in hot arid zone to examine its importance and effect in the formalization of sustainable and suitable housing clusters.


Article
تثبيت نظام المعلومات الجغرافية GIS في العراق

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Abstract

Growth of cities made Urban Designers and Planners determine to the extent that need to knew solutions appear to maintain and analyze data, especially regarding dealing with 3D geometrical information and concepts integration on building them to enable analysis and ensure 3D rapid visualization as complication and mutual relations among various data types (3D spatial and non -spatial) and users vary greatly that current information systems face difficulty in dealing with, analyses and completing them, confusing the process of Urban Planning and conduct nowadays rather than a decade ago; it was necessary to set an attempt to combine available technology components and develop new concepts to conclude a system that meets users' requirements and solves problems of urban planning and of information users better . Therefore, focus was on a 3D system to conclude the concept of building objects and their attributes to allow efficient recovery and display, where focus is on 3D spatial objects; since demand of 3D spatial information is the most urgent. So , the aim is identifying the conceptual model capable of dealing with a variety of object and relations of interest for urban planners appropriately to analysis and 3D interactional visualization using current technological developments , so that object of no spatial range are combined in the database according to objective classification , so that spatial object , classification with objective characteristics can work according to hierarchy in semantic and geometrical domains this to be integrated by possibility of introduction of this public system to Iraq in general and Baghdad in particular by attempting suggesting conducting that system as a start to be the responsible for its application for real . The research was finished with cooperation of many parties abroad to reach its desired aim.

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Article
انتاج خرسانة عالية الاداء باستخدام انواع مختلفة من البوزولانات المحلية

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Abstract

High Performance Concrete (HPC) is considered as one of the most important products known by the construction industries during the last years in the field of producing new and improved types of concrete. This new type of concrete has an essential importance due to its high compressive strength, superior resistance for external salt attack and its low permeability. This paper is concerned with experimental investigations for evaluation of high performance concrete using a new type, locally available pozzolan. The results are compared with that obtained from using well known micro silica. The experimental work also includes the possibility of activation in order to improve the quality of HPC; the experiments mainly deal with the chemical analysis and the selection for the optimum dosages of additive. The properties of HPC are studied in both fresh and hardened stages. The effect of pozzolan additive on shrinkage was also considered to provide an index for the durability of concrete.

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Article
Finite Element Analysis of Embankments on Soft Clays - Case Studies
التحليل بالعناصر المحددة للتعليات الترابيية على تربة طينية رخوة – دراسات حالة

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Abstract

In order to design structures on soft soils, it is necessary to predict the behavior of the soft soil under imposed structure load. The high excessive settlements of the soft soil can cause many problems for the structures built on the soil like cracking and breakup of pavements, railway, highway embankments, etc... In this work, the finite element method is utilized as a tool for carrying out different analyses of embankments on soft ground with different conditions. The computer program CRISP (CRItical State Program) is developed to suit the problem requirements. CRISP uses the finite element technique and allows predictions to be made of soil deformations using the critical state theory. Eight-node isoparametric quadrilateral element has been added to the program. The program was used to analyze fully coupled (Biot) consolidation of two-dimensional plane strain problems. The finite element predictions of displacements and excess pore water pressures were compared with field measurements. It was concluded that the maximum vertical movement occurs below the centerline of the embankment. The settlement decreases slightly as the toe of the embankment is approached and decreases rapidly as the distance away from the toe increases. Upward movement of the surface far from the toe is observed. The maximum horizontal movement occurs near the top boundary. The rate of horizontal movement at the top of the foundation is greater than at the bottom. This behavior may be due to the flexibility and free movement condition of the vertical boundary in the top half.


Article
Effect of Transverse Base Restraint on the Cracking Behavior of Massive Concrete
تأثير تقييد القاعدة العرضي على سلوك تشقق الخرسانة الكتلية

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Abstract

The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggested by ACI Committee 209 and inverted to equivalent temperature differences to be added algebraically to the temperature differences obtained from thermal analysis. Willam-Warnke model with five strength parameters is used in modeling of concrete material in which cracking and crushing behavior of concrete can be included. The ANSYS program was employed in a modified manner to perform the above analyses. A thick concrete slab of 1.5m in thickness and 10m in length was analyzed for different widths 2, 4, 8, and 10m to produce different aspect ratios (B/L) of 0.2, 0.4, 0.8, and 1.0 respectively. The results of the analyses show an increase in cracking tendency of mass concrete member as the aspect ratio of the same member is increased due to the effect of transverse base restraint. Accordingly, such effect cannot be ignored in the analysis of base restrained mass concrete structures subjected to temperature and drying shrinkage volume changes.


Article
PID Controller Design for the Satellite Attitude Control System

Authors: Sami Kadhim Hasan Ar-Ramahi
Pages: 3312-3320
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Abstract

A PID controller satellite attitude yaw-axis control system was designed to step the angle of the satellite body via actuating a precise angular position of a DC motor as quickly and accurately as most optimally possible. The (PID) controller was advantageously chosen for its quick transient response and zero steady-state error. A mathematical model has been derived for the whole satellite attitude yaw-axis control system. Then, the computation power of the MATLAB is utilized to obtain a generalized optimal controller design that enables the satellite attitude yaw-axis control system to have the quickest settling time without excessive overshoot and zero steady state error.


Article
Analysis of Consolidation Behavior of Subsoils under Cyclic Trapezoidal Loading

Authors: Duraid Ali Al Khafagy --- Zainab Ahmed Alkaissi
Pages: 3321-3335
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Abstract

This paper is aiming to develop a numerical procedure using the finite element method for the analysis of soil consolidation by taking into consideration the loading and unloading cycles with particular emphases on the pore pressure built up. The study is concerned with trapezoidal cyclic loading. The shear stresses that are developed in the subsoil due to cyclic loading cause shear strains and change in the mean normal stresses due to distortion of soil element. Biot’s consolidation theory that adopted in this study may be able to take these changes into consideration. The results indicated that the excess pore water pressure increases with load cycles and finally, a steady state conditions are reached. This may be attributed to the undrained cyclic shearing stresses to the origin initial cyclic shear stress ratio. Also it can be explained that when the load is applied very fast the collapse load approaches that undrained conditions, whereas when the load is applied very slowly the collapse load approaches that under drained conditions. When the elastoplastic model is considered the pore pressure are considerably larger than those predicted by the elastic consolidation analysis. This can be attributed to the plastic volume strain that have been taken into consideration in the elastoplastic model.


Article
Improved Data Detection Processes using Retraining over Telephone Lines

Authors: Sarcote.N..Abdullah
Pages: 3336-3346
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Abstract

This paper describes two new developed detection processes for a modem over the public switched telephone network. The modem is a synchronous serial system using a 16-point QAM signal with a detector. The detector is preceded by an adaptive filter that is adjusted to make the sampled impulse response of the channel and filter minimum phase. The idea of these two new detectors is to transmit a known retraining data every specified interval and make use of these known data to improve the conventional nonlinear equalizer and near maximum likelihood detector. Results of computer simulation tests are presented comparing tolerance to additive white Gaussian noise with retraining and with out retraining. The detectors with retraining achieve a better noise performance than conventional detectors. Furthermore the amount of retraining data is varied to find the best compromise between efficiency of data transmission and performance improvement.


Article
Building an Integrated System for Management of Projects ((Some Water Projects as a Case Study))

Authors: Ziyad J. Fadhal --- Rafa H. Al- Suhaili
Pages: 3347-3367
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Abstract

Many useful softwares in projects management are available now. Ms Project and Primavera are some examples of these softwares. Those programs need to be fed by information by the user. The users usually collect this information from the project and design documents. This collection process needs considerable time and efforts, and usually accompanied of some errors in data transfer process. In order to reduce the required time and efforts and to eliminate individual errors in data transfer process, an Integrated System is needed. This Integrated System can extract the graphical information from an AutoCAD drawing and transfer it to a digital form suitable for processing in the project management softwares such as Excel and Ms Project. In this research an Integrated System (IS) was built, to connect three softwares, AutoCAD, Excel and Ms Project, using Active X data transfer technology. The Integrated System was tested using three case studies. Al-Nahrain University waste water network, the Islamic University water supply network, and an irrigation and drainage project. The results indicated the capability of the system to transfer the graphical data into digital data, and to conduct the quantity of survey of the selected projects. It is worthy to mention that this system requires some modification that is should be adopted in the AutoCAD drawings. The drawings should be performed using layers, and definition blocks for objects. These modifications are simple and can be done easily. Moreover the system was built in a way that gives the ability of adding other case studies (i.e., other types of projects).


Article
Nonlinear Analyses of Partially Composite Steel Beams Encased in Concrete with Innovative Position of Stud Bolts

Authors: Raad K. Shukur
Pages: 3368-3391
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Static behavior of three partially encased composite steel beams with cambering under flexural condition is investigated in the context of studying some alternative positions for the headed studs. Shear resistance between the cambered I-shaped beam and the concrete was provided by headed studs in two positions: vertically welded on the bottom flange and horizontally welded on the faces of the web. In the present study, a nonlinear three-dimensional finite element analysis has been used to predict the load-deflection and moment-rotation behaviors of composite encased beams consisting of steel sections using the finite element computer program (ANSYS V. 10). Composite encased beams are analyzed and a comparison is made with available experimental load-deflection curves, good agreement with the experimental results is observed. Cambering of steel section is introduced on the steel section of the composite beams encased in concrete. It is found that using of steel section with cambering can increase the ultimate load capacity of the composite encased beam by relatively (15%) and also it is found that deflection are nearly (65% to 80%) the deflection of the same beam without cambering. Parametric studies have been carried out to study the increasing of the moment-carrying capacity due to the use of encased concrete; meanwhile the slip along the beams length is studied. The strain distributions along the steel section and encased concrete depth are also examined. The effects of concrete compressive strength on the stiffness of the composite encased beams are also investigated with the Poisson’s ratio of concrete and the effect of cambering of steel-section.


Article
Effect of Al Huwayza Marsh Boundary Configuration on the Velocity Patterns and Water Quality Distribution

Authors: Shaimaa U. Kareem --- Riyadh Z. Al Zubaidy
Pages: 3392-3412
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Abstract

A two-dimensional depth-averaged hydrodynamic model and a two-dimensional water quality parameters transport model were developed to simulate the characteristics of Al Huwayza Marsh, which is considered the largest and most important marsh in the south of Iraq. The hydrodynamic model for Al Huwayza Marsh was built by using RMA2 model, while the water quality model was built by using RMA4 model. These two models are part of Surface Water Modeling System, SMS, software package. To investigate the effect of the marsh boundary configuration on the variation of the velocity pattern and the water quality within the marsh, both of the hydrodynamic and the water quality models were applied to three cases of boundary configuration of Al Huwayza Marsh. The first case represents the natural extension of the marsh boundary. The second case represents the existing boundary configuration of the marsh, in which the south west of the marsh is bounded by a dyke. The third case represents the Iraqi part of the marsh bounded by the south west dyke and a dyke along the Iraq-Iranian borders, which when completed will separate the marsh into two parts. Models runs were based on above cases of Al Huwayza Marsh boundary configuration and topographical survey, hydrological measurements and routing, and water quality measurements carried out by the Center of Rehabilitation of Iraqi Marshlands. Discharges of all feeders and stages of the outlets are considered for wet, normal, and dry years. Feeder’s seasonal discharges were averaged. High and low concentrations of three selected water quality parameters of the marsh feeders were adopted in the model runs. Generally, it was found that the flow velocities are relatively high at the inlets and outlets of the marsh. The construction of the dyke along the Iraqi-Iranian border leads to variation in the direction of water flow in all portions of the marsh and a great reduction in AsSuwayb River discharge. While, a slight effect was noticed in the mixing process of the feeders’ water of different concentration in case three compared to other cases.


Article
Effect of Ice Formation on Airfoils Performance (Part-I)

Authors: Haitham Q. Hasoun --- Najdet N. Abdulla
Pages: 3413-3432
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Abstract

A numerical investigation was conducted to study the effect of simulated ice accreted on airfoil aerodynamics performance. The simulated ice shapes were tested on NACA 0012 airfoil wing at different Mach numbers. The study includes the one of the famous types of ice accreted on the airfoils called the rime ice. The calculation of ice droplet trajectories was performed by solving the trajectories governing equations of the droplet using FVM. A numerical model based on staggered FVM is built up to solve the governing equations of a body fitted grid, trajectories equation, continuity equation and momentum equation using FORTRAN 97. The turbulence model of (k-ε) has been adopted in the programming to evaluate the turbulence effect. The program is valid for any type of 4 or 5 digits airfoil. The program is available to evaluate the rime ice accumulation. The pressure, lift, drag and pitching moment coefficients are computed and compared with that of clean case results. The program was run over different Mach numbers, to compare the results obtained at these Mach Numbers. The investigation of the work was tested on NACA 0012 in a range of angle of attack 0º to 6º, where stall starts at this angle of attack as demonstrated by the results. The results show that the severity of ice formation could be more dangerous with increasing the angle of attack or the Mach number.

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Article
Numerical Investigation of the Cavitation in Pump Inducer

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A numerical investigation of the non-cavitating and cavitating performance of a three-blade pump inducer under nominal and off-design operating conditions is presented. Three different simulated hydrofoils; a flat plate, “NACA0004", and "Clark-Y-6%" has been selected to represent the profile of the inducer blade. A 2D, steady, incompressible, turbulent, and isothermal flow field between the inducer blades is simulated using the FVM. The "Interface Tracking" model is selected to predict the cavity profile of the attached cavitation and the cavitating performance drop. For each blade profile, the influence of solidity in the range of (1.8 to 3.0) and blade angle in the range of (20° to 35°) on the inducer performance is studied. Comparing the present model with available experimental and numerical results, confirms that the developed model well predicts the general non-cavitating performance for an inducer having a flat plate blade profile. For "NACA0004", or "Clark-Y-6%" hydrofoil blade profiles, a reduction in the operating range of these inducers is produced. In addition, the developed model predicts the inception of cavitation earlier than the experimental results. The predicted cavitating head drop curve of an inducer having a flat plate blade profile is compared with available experimental results and a good agreement is obtained. The drop curve occurs suddenly and simultaneously with the experimental one. For "NACA0004“, or "Clark-Y-6%" hydrofoil blade profiles, a smooth curves with simultaneous or gradual head drop occurs with the experimental one, respectively. Generally, the agreement between the results is satisfactory.


Article
Effect of Obstacle in River on the Heat Dissipation of Hot Water Injection

Authors: Ayser M. Fleh
Pages: 3443-3465
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Numerical analysis of the cooling process of hot water discharge from a steam power plant into a river has been carried out in the present study. A mathematical model describing the flow field and temperature distribution induced in the river as a result of the cooling process is made based upon the assumptions of steady state, two-dimensional, turbulent flow, in the horizontal plane. The governing equations are the continuity, the momentum, the (К-ε) turbulence model and the energy equation. A proper initial and boundary condition are specified to be used in the solution of the governing equations. A numerical solution of the governing equations is made by using the control volume approach, with non-staggered grid technique and modified SIMPLE algorithm. The numerical solution is capable of calculating the velocity and temperature distributions of the calculation domain. The numerical results show that the developed algorithm is capable of calculating the flow field, properly and accurately. Results are obtained for ten cases of configuration, constant aspect ratio and weather conditions for Baghdad. The results show that the injection velocity effect on the temperature distribution and stream line , the exist of obstacle and its distance from the injection zone but the increase in injection temperature cause a small effect on temperature distribution and stream line.


Article
Numerical Investigation of Turbulent Natural Convection in an Inclined Square Enclosure

Authors: Khudheyer S. Mushatet --- Qasim S. Mehdi
Pages: 3466-3481
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Two dimensional turbulent natural convection heat transfer and fluid flow inside an air filled inclined square enclosure differentially heated has been numerically studied. Fully elliptic Navier- Stockes and energy equations are solved using finite volume method. The problem is simulated for different angles of inclination (0 <= theta <= 180 deg) and Rayleigh numbers (10^8 <= Ra <= 10^16 ). The turbulence k-є model is used to model the effect of turbulence. The wall function approach is used to model the regions near the walls of the enclosure. The obtained results from this study show that the rate of heat transfer is increased with the increase of Rayleigh number and decreased with the increase of angle of inclination(0 <= theta <= 90 deg.).Also the induced vortices are strongly elongated with increase of Rayleigh number. The thickness of thermal boundary layer is decreased with the increase of Ra. The validation of the present code was done by comparing the computed results with the published ones. The comparison indicated a good agreement.


Article
Simulation of Casting Solidification Parameters in Metallic Mould

Authors: Akeel D. Subhi --- Ayad M. Takhakh
Pages: 3482-3491
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In this work, numerical method approach has been used to simulate the solidification parameters of an eutectic aluminum-silicon alloy in chilled metallic mould with copper. The approach is based on the solution of heat flow equations of the casting and mould. In addition, the latent heat is treated as a boundary condition between the liquid and solid phase. The results showed that different behaviors of solidification parameters are obtained along the casting. Furthermore, the simulation approach of solidification parameters in conjunction with the microstructure indicated that it is possible, to a large degree, giving a knowledge about the microstructural features for any alloy system.


Article
Vibration Analysis of Rotating Pre-Twisted Cantilever Plate by using the Finite Element Method

Authors: Oday I. Abdullah
Pages: 3492-3505
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In this paper the finite element method has been used to determine the fundamental natural frequencies of a pre-twisted plate mounted on the periphery of a rotating disc. Three dimensional, finite element programs was built using three noded triangular shell element as a discretization element for cantilever plate, this element has six degrees of freedom at each node. All formulations and computations are coded in (FORTRAN-77). The investigation covers the effect of speed of rotation, disc radius, aspect ratio, pre-twist angle and skew angle on the vibration characteristics of rotating cantilever plate. For this analysis, the initial stress effect (geometric stiffness) and other rotational effects except the corioles acceleration effect have been included. The eigenvalues have been extracted by using simultaneous iteration technique. Results shown that the natural frequencies increase when; angular speed and disc radius are increases.


Article
Performance Analysis of Inverter-Fed Single-Phase Induction Motor

Authors: Amer O. Kareem --- Ali M. Saleh
Pages: 3506-3520
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This study investigates the effects of the presences of harmonics in the exciting voltage when using a dc/ac inverter on the performance of a single-phase induction motor, the investigation includes theoretical and experimental parts and together with performance comparison of the motor with the nominal sinusoidal input voltage. The computed performance of the motor depend on the theoretical equivalent circuits which are modified to take into account the existence of harmonics in the inverter output to compute the performance at each harmonic order. It conclude from the analysis that the pulsating torque is inherent in single-phase induction motor even when supplied from a sinusoidal voltage source. Particular attention has been devoted to the pulsating torque when the motor is supplied from an inverter and the most important pulsations have been identified. The comparisons of simulation and measured results show good correlation between them in addition that it highlight and identify the cumulative effects of harmonics on the motor performance.


Article
Drag Reduction by using Anionic Surfactants

Authors: Hussein H. Hussein --- Sameera M. Hamad-Allah
Pages: 3521-3536
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The aim of reducing drag is to increase the flow efficiency by using the same pipes and pumps. As a result the amount of crude oil transported will increase without using new pipes and pumps. In the present work, the effectiveness of two surfactants (Sodium dodecyl benzene sulfonate (SDBS) and Sodium lauryl sulfate (SLS)) are studied by using a closed loop system. This system consists of three pipes made from commercial steel, each one with different diameter (0.75, 1 and 1.5 inch). The length of each individual test section of the pipe is two meters. The experimental work is achieved under three different temperatures (30º, 40º and 50°C). The concentrations of both surfactants used are ranging between 50 to 300 weight ppm. Laboratory tests showed that there is a direct proportionality between the percentage of drag reduction (%DR) on one hand and in Reynolds number and pipe diameter on the other hand. Inverse proportionality is observed between %DR and temperature. The %DR increases as concentration increases, but at a certain higher concentration, this relation will reverse. The final results showed that the highest drag reduction (%DR) was 23.67%. This value is obtained when 200 ppm SDBS is added at 30°C. The calculated values of friction factor were found to be situated between Blasius and Virk asymptote adjacent.

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Article
Preparation of Nd – Fluoride Laser Glass and Investigation of its Characteristics

Authors: Ziyad H. Rasheed --- Saad S. Rahmatallah
Pages: 3537-3552
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Fluorophosphate neodymium laser glass has been prepared by discontinuous melting technique. Special melting and casting conditions were followed to prevent devitrification of glass samples. Furnace melting followed by slow cooling resulted formation of non vitreous glass. Problems of high viscosity melt and incomplete solubility and immiscibility of glass components were encountered by adjusting composition of glass components. X-ray diffraction analysis of the prepared glass samples proved the formation of amorphous phase. The prepared Nd – fluoride glass has low refractive index which is an important parameter for high power laser application. Optical properties of Nd – fluoride glass samples were investigated. UV – visible spectra showed almost total absorbance of light at wave length below 400 nm, while in the visible range a typical spectrum of Nd3+ ions covers the entire range. Infra – red spectral properties of these samples were studied. Transmission of the glass was found to be dependent on neodymium concentration.


Article
The Deflection Control of a Simply Supported Thin Beam by using a Piezoelectric Actuator / Sensor

Authors: Waleed Kh. Al-Ashtari
Pages: 3553-3571
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Piezoelectric transducers have become increasingly popular in vibration control applications. They are used as sensors and as actuators in structural vibration control systems. They provide excellent actuation and sensing capabilities. In this paper, the term smart beam refers to a beam with a finite number of collocated piezoelectric actuator / sensor pairs. The proposed thin smart beam governing equation was derived by the same procedure that the Bernoulli-Euler equation derived but with some additional mathematical terms to be valid for describing the smart beam. The engineering control techniques were used to obtain the solution of the proposed differential equation for the simply supported beam where with some auxiliary equations and modifications a block diagram for any type of applied load (static, or cyclic) as the input and the beam deflection as the output was constructed. For insuring an efficient reduction in the beam deflection an integrated system with a high voltage amplifier and lead controller was designed. Many cases were studied and simulated including the variation of load nature and its frequency, and the number of collocated piezoelectric actuator/sensor pairs and in all cases a valuable deflection reductions were obtained.

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