Engineering and Technology Journal

Atrajectory tracking controller based on integral control technique for the wheeled differential mobile robot using the kinematic model is proposed in this paper. The proposed controller design is achieved by using the nonlinear kinematics model of the mobile robot which is being transformed to a nonlinear error model by shifting its states to the origin and by adding a dummy integral control state variables that are augmented with the nonlinear error model, the model became ready to be used to design a controller. The nonlinear controller which will enforce the system dynamics to follow the desired trajectory guarantee that the steering control system of the mobile robot will behave as a second order reference model with specified natural frequency and damping ratio is being selected by the designer, and the average speed control system will behave as a first order reference model with specified time constant chosen by the designer. The simulation results which is achieved by using MATLAB Rev. (14.9 2009b) show the potential of the proposed controller to track the mobile robot to the desired trajectory with very slight error.

This paper focuses on the effect of machine vibration on the variation of excess pore water pressure and settlement of saturated sand. A special setup is designed and manufactures to simulate the vertical vibration of the machine. A total number of 36 model tests are conducted on sand using three relative densities (35, 60 and 85%) representing loose, medium and dense sand respectively. These tests were performed on saturated sand, and tested under dynamic load. Different load amplitudes (0.4, 0.6 and 0.8 kN) and different frequencies (0.16, 0.5, 1 and 2 Hz) were used.
The results show that, the settlement in saturated sand under vibrating load increases with increasing load amplitude while it decreases with increasing frequency and relative density, but the rate of settlement decreases as the load increment increases. The maximum increase in settlement ratio reaches about 36% when the load amplitude changes from 0.4 to 0.6 kN while it is only 21% when the load amplitude changes from 0.6 to 0.8 kN.
The excess pore water pressure increases with increasing the load amplitude, frequency and relative density. The rate of change in excess pore water pressure increases about 30% as the load amplitude increases from 0.4 kN to 0.6 kN while it increases only 21 % when the load amplitude increases from 0.6 kN to 0.8 kN under the same frequency and relative density

The design and implementations of a mobile target tracking system using field-programmable gate array (FPGA) are presented in this work. The idea of variable dimension (VD) filter which is used for tracking the nonmaneuver and maneuvering target is simplified and demonstrated by the FPGA implementations.
In general, the VD filter consist of two different Kalman filter dimensions and the fading memory detection scheme. In this tracking algorithm, the first Kalman filter is operates in its normal mode in the absence of any maneuvers, at same time, from the property of the innovation sequence and state estimates of this filter, the fading memory detector switch is used to determine that a maneuver is occurring, once a maneuver is detected the second augmented Kalman filter which uses a different state model is used to track the target in maneuvering motion course.
In this paper, the single Kalman filter is used to replace the second augmented filter of the VD algorithm, in this case when the maneuver is occur, the single filter is used in parallel with the first Kalman filter to track the target in maneuvering motion course without modifying the operation of the first Kalman filter. This step will simplified and reduce the calculation of the VD filter.The implementation for this system using FPGA will discuss in details, it will resulted to implement a low cost and mobile tracking system with high flexibility. Many of the general results presented in this paper are also useful for performance evaluation of this simplified variable dimension (SVD) filter algorithm as a compared with the VD filter algorithm.

Friction stir welding is a relatively new joining process, which involves the joining of metals without fusion or filler materials. In this study, the effect of tool pin profile on the mechanical properties of aluminum alloys AA2024-T351 joints produced by FSW was investigated. Four different tool pin profiles were developed, (straight cylindrical, taper cylindrical, triangular, and square) to weld the joints. All the welds were produced perpendicularly to the rolling direction for aluminum alloys. Tensile and bending tests were performed to evaluate the mechanical properties by using computerized universal testing machine. Among the four tools, square pin profile gives better tensile strength (265 MPa), elongation (4.9), maximum bending force (1450 N), and maximum welding efficiency (61%) in terms of tensile strength

An experimental study of composite columns of hollow circular aluminum tubes enhanced with a fibers reinforced polymer (FRP) sheet and filled by lightweight concrete are presented in this paper. The study's scope is introducing and developing lightweight columns to be advantageous in lightweight and size limited structures. The test results discussed the influence of internal and external confinement effectiveness introduced by lightweight concrete and carbon fiber reinforced polymer (CFRP) retrofitting sheet, respectively. The column specimens were subjected to uniform axial compression load. Structural aluminum alloy circular hollow section has been used in this investigation. Carbon fiber reinforced polymer (CFRP) is used to piling aluminum tubes. Light weight expansion clay aggregate (LECA) is used to fabricate light weight concrete filling aluminum tubes. The strengths, shortening displacement, axial strains, lateral strains, and failure modes of columns were presented. The test results indicated that confinement and composite action between the constituent materials resulted in enhanced compressive strength, ductility and energy dissipation capacity of the proposed composite column. Finally, a simplified design equation is proposed to predict the compressive load capacity of this type of composite column.

In the present work, experimental study has been done to estimate the performance of solar heating system by air-water (Dual) solar collector. Flat plate dual solar collector with dimensions (120 cm length, 80 cm width and 15 cm thickness) has been used for heating the test space with dimensions (2×2×2.5) m. In this study, the system has been operated in Al-Najaf city with 45o tilt angle to the south. The results obtained that the dual flat plate solar collector daily efficiency is 52.02 %.They also showed the ability to use dual solar collector absorber as heat exchanger in the night to maintain room temperature in the comfort condition for space heating in the winter season

Real time smart electrical energy meter network is one of the backbones for modern smart grid. It is very critical to have the right technologies for the efficient operation of smart meter network. In this paper, real time wireless smart electrical energy meter system has been designed and implemented which PIC microcontroller is used for real time energy measurements. In this system, all real time energy measurements will be send to base station through ZigBee wireless sensor network (WSN) for managements and monitoring. Also database will be design to record and manage all data and information of consumers.

Robot Forward kinematic equations' analysis is an essential and important manner to analysis the position and orientation of the end effectors of a robotic manipulator, where in this paper, Denavit-Hartenberg notation and method (D – H) is used to represent the relative kinematic relationships precisely between each two adjacent links of this robot , besides a kind of artificial neural network (ANN) which is known as the supervised learning training sets network is investigated to solve the problem of kinematic analysis of this laboratory five - axes robot, it shows that the using of the artificial intelligence method which is the neural networks had offered the facility of dealing with this non linear robotic system by a simple manner with acceptable faster solution as compared with the traditional forward kinematic equations analysis method

A proposal method for data transfer from CAD to CAM program has been investigated in the present work using iterative process for the stamping dies. The Bezier and B-spline equations forcurves and surfaces of n-degree had been derived as a matrix and formulated using MATLAB program, then a computer program had been constructed for the data transfer as a case study. The procedure of converting the profile of stamping dies from CAD program to CAM program without any geometrical distortion had been presented. The implementation of data transfer and the simulation using UGS(UniGraghics Solutions) program observed that the transformation of any complex profile shape from CAD to CAM program done without any distortion in final shape of the profile in CAM program. The present method matched the experimental result conformity and used in short time as compared with other methods.

This research deals with measurement of the density of vehicles traffic. The traffic density is estimated from an image captured using the ordinary optical camera. An image processing methods is used and the edge of the objects is extracted. A two dimensional wavelet transform is used as a feature extraction. The extracted features were reduced by Multiple Region Centroid Estimation. A neural network is trained using many sets of images with different Traffic densities then it is used for traffic measurement. A classification rate of 98% can be achieved

The strength of concrete is considered as the most basic and important material property in the design of reinforced concrete structures. The two standard methods (ASTMC39-03 and BS1881-part 116) for determining the compressive strength of concrete are the testing to failure of cylinder and cube specimens respectively. It has become a problem to use this value as the control specimen sizes and shapes are different from country to another.
This study is made to comparison between propose hexagonal specimens with the standard cylindrical one in behaviour of specimens with different sizes under compression load. The new hexagonal specimen has a cross sectional area 4% greater than the cylindrical cross section. The volume of the hexagonal specimen is approximately equal to the cylindrical ones to give a greater uniformity of results. This proposed shape has height to average diameter ratio (H/D) = 1.95.
The hexagonal mould has the ease of making a control specimen while avoiding the capping process which is necessary in cylinders and reducing the cost and time it takes to prepare. When the hexagonal specimen cast in horizontal plane so no need for end preparation because the top and bottom surface of the specimen who will be in contact with platen of testing machine, are 100 % levelled and orthogonal to the height of the specimen. Results show that the mean ratio of compressive strength for hexagonal to cylindrical specimen is 0.95.The results of testing specimens show that the compressive strength of the specimen obviously increases with decreasing the ratio of H/D. This behaviour is proving that the hexagonal specimen acts like the standard cylindrical in stress distribution.
The using of hexagonal specimen to find the strength of concrete give better factor of safety in structural design that because strength determined from hexagonal specimens will be slightly smaller when compared with results determined from cylindrical and the behaviour of the hexagonal shape is similar to cylindrical one.

Sliding Mode Controller (SMC) is a simple and effective method to recognize a robust controller for nonlinear system. It is a strong mathematical tool which gives a nonlinear robust controller with acceptable performance. The chattering phenomenon is the major drawback that sliding mode control suffers from. This phenomenon causes a zigzag motion along the sliding surface. In this work to design SMC, the Saturation function (i.e., boundary layer) has been used instead of the Sign function that was used in classical sliding mode controller in order to reduce the chattering phenomena which are appearing in the sliding mode phase. The genetic algorithms have also been proposed in this work for the parameter selection method of Sliding Mode Controller and the results showed a high speed of the system state for reaching the sliding surface during the reaching phase and a chattering reduction during the sliding phase. A pendulum system has been used for testing the designed sliding mode controller. The simulation results showed good validity of the suggested method. Matlab programming and simulink were adopted for the simulation results

The present work deals with the effect of the magnetic field on the performance of spark ignition engine. The engine performance was observed by examining the fuel consumption and brake specific fuel consumption for different values of octane number (68, 75, 83 and 85), to find out what sample of octane number is affected by a magnetic field significantly more than the others.
The experimental results showed that the fuel of octane number 75 exhibited a reduction in fuel consumption (L/h) up to (11.73%) and (21.48%), and brake specific fuel consumption (Bsfc) up to (11.11%) and (19.9 %), for one and two magnets respectively. Fuel of octane number 83 showed a reduction in fuel consumption (L/h) up to (0.907%) and (2.13%), and for brake specific fuel consumption (Bsfc) up to (0.96%) and (1.83%), for one and two magnets, respectively. For fuel of octane number 85, the reduction in fuel consumption (L/h) was (0.322%), and for brake specific fuel consumption (Bsfc) was (0.47%), for two magnets only.

The present work is aimed to study the fatigue behavior of friction stir welding for the similar and dissimilar joints taking into account the effects of welding position, post welding heat treatments, and surface roughness. The materials were used AA2024T3 and AA6061T6. The maximum welding efficiency achieved at friction stir welding process was 62.8 % of the base metal for the similar 2024-T3 joint, and this value was improved by using post welding heat treatments and reach to 67.9%. Results showed that fatigue strength at 106 cycles depended strongly on welding line position where for welding line at a distance 0.35L from loading side, the reduction in fatigue limit with respect to 2024T3 base material was 45% for similar joint and 58% for dissimilar joints, and for welding line at a distance 0.7 L, the reduction in fatigue strength was 56% for similar joint and 67% for dissimilar joints. While, it was a large reduction in the fatigue strength reaching to 70% in both similar and dissimilar joint for the welding joint at a distance L (i.e at the fixing end). The heat treatments improved the fatigue strength about 31% more than non heat treatments of the similar 2024T3 joint by fsw at 0.7L in high cycle regime. Finally, the non-finishing samples showed a reduction in fatigue strength reaching to 10% more than the finishing samples of the similar 2024T3 joint at 0.7L.

Forced convection heat transfer of air in porous rectangular duct was investigated experimentally . The pad consist of (zig-zag ) metallic wire mesh insert with two different porosities ( ????????) namely ( 0.97 ) and ( 0.99) .The experiments were
carried out for Reynolds number (7682,12497 and 17323 ) and constant heat flux
(192,297 and 422 W/mP
2
P ) .The results indicated that Nusselt number was increased
with increasing Reynolds number and heat flux but decreased with increasing pad
porosity .The Nusselt number in the porous duct was increased up to (144% ) for
(???????? = 0.97) and (72% ) for (???????? = 0.99) when compared to clear duct at the same tested
condition . For optimization between heat transfer enhancement and pad weight
added into clear duct , it is found that [ (NuRporousR - NuRclear R ) / weight of pad ] equal to
(84.34 ) and ( 40.49 ) for (???????? = 0.99 and ???????? = 0.97) respectively and this is good
improvement in heat transfer through porous rectangular duct and reducing size and
weight of original duct

High performance concrete, HPC, requires a low water-to-cementitious materials mass ratio w/cm and supplemental cementitious materials with silica fumes in the mixture, and use of a superplasticizer. Because of the low w/cm and rapid reaction at early ages, it becomes more difficult to provide curing water from the top surface and this water will be inadequate to satisfy the conventional curing. Therefore, there is a need to use internal curing that is supplied via internal materials, such as absorbent lightweight aggregate, which will be pre-saturated. The use of internal curing was investigated in this study by two ways. The first way was through the use of partial replacement of original coarse aggregate (gravel), meanwhile, the second was by replacing partiallythe original fine aggregate (sand)by crushed Porcelinite.The results showed that the fine Porcelinite replacement as internal curing material caused better enhancement instrengthof HPC than coarse Porcelinite. The replacement of original fine crushed Porcelinite caused an increase in compressive strength from 3.36 to 5.25percent, for splitting tensile strength from 5.48 to6.85 percent and for flexural strength from 11.76 to 12.74percent

The effects of vertical cooling internals on the gas hydrodynamics was studied in gas-liquid system (bubble columns) for column diameters, 15 and 30 cm in the absence and presence of internals (the % occluded area by internals 5, 10, and 20%). The superficial gas velocity was varied in the range 0.8-30 and 0.8-7.6 cm/s for 15 and 30 cm column diameters respectively. The effect of internals on the bubble dynamics in columns was assessed using the electroresistivity probe technique. The overall gas holdup is measured experimentally by bed expansion technique. The experimental results show that the increased in percentage coverage of cross sectional area by internals causes an increase in the overall gas holdup values, gas holdup radial profiles, bubble rise velocity, bubble frequency and reduce average bubble diameters. Correlations have been used for the estimation of the gas holdup in gas-liquid system bubble column. The overall gas holdup can be easily predicted from 516.1086.008.1/165.0int%142.000286.0RrUgg−+=−ε.Comparison of the model predictions with the experimental data shows agreement with error 0.017 which ensure the reliability and confidentiality of the adopted the correlations to be used in further designation and scale-up purposes.

In this study, a mild steel alloy has been used to determine the influences of voltage, temperature, concentration and time on the film growth, thickness, characteristics and properties of anodic oxide film. A Box–Wilson experimental design method was used to determine effects of parameters and optimum conditions for anodized mild steel alloy. Anodizing of the mild steel alloys in potassium hydroxide solution generates the barrier and porous layers of anodic films according to the conditions used. Mild steel alloy is anodized under different conditions in the KOH solution. Constant voltage technique is used to form oxide films on mild steel alloys in (KOH) electrolyte as a function of the anodization voltage of (1-6V), concentration of (40-70Vol. %), temperature of (20-100°C) and anodization time of (5-75 min). The second order response surface model is given in equations. The model is used in the formulation of objective and constraint functions for the optimization of a optimum conditions of mild steel:
T=2.949+0.781X1+0.131X2+1.240X3+0.334X4+0.047X11+0.003X22+0.377X33-0.153X44+0.041X12+0.115X13+0.026X14+0.046X23+0.025X24+0.141X34 Optimum conditions for anodizing mild steel in the alkaline solution were determined by Hook and Jeeves method. The optimum conditions were found as follows: voltage (1V), KOH concentration (40Vol.%), temperature (20°C), and time (5 min). The thickness for mild steel alloy was [0.65μm]. The electrical conductivity characteristic of the oxide was measured; it was found that it has electrical conductivity but with different values depending on anodizationconditions. Different colors of anodic oxide film are formed on carbon steel alloys and change with different conditions. The pores diameter for mild steel was [91.78 nm]. AFM topography shows the roughness values of mild steel is [0.496 nm]. The microhardness of anodic oxide film was [1477.5 Hk].

The importance of invisibility lies in the fact that it is a significant means to convey doubt and uncertainty which the consumer looks for before achieving full satisfaction. Moreover, the terms were presented as opposites, and have been studied separately or as a duet in many architectural surveys. However, those studies lacked a clear definition of the terms and the nature of transition between them as well as the meaning conveyed and how the consumer receives it. This generates the research problem which is "the lack of perception of the relationship between the visible and the invisible in architecture and its effect of the meaning". Thus, the research objective is “stating the connection between the visible and the invisible and its effect on the meaning”. The research falls in five parts, the first of which presents the definition of both terms (visibility and invisibility) and how they work as a duet. Besides, it derives a duet sample diagram which presents a group of mixed cases (visible invisibility, visibility and invisibility at the same time, and invisible visibility). The second part shows the direct and indirect architectural studies and a discusses the cases in the duet diagram; in addition to that, it analyzes the cases in which they appear (like the case of visibility that trigger invisible visibility, and the gradual transformation). The third part offers a final form of the diagram and analyzes its numerous features. The diagram also surveys its relation to the materialistic and immaterialistic, the external and internal effects, the visible and the invisible, the ideologic and material aspects, and the direct and gradual change among the stages of the diagram. The fourth part presents the analysis of two architectural examples to test the accuracy of the resulting diagram. Finally, there is the discussion of the results and a display of final conclusions

It has been noted that many distinguished buildings are neglected and sometimes destroyed due to misuse, carelessness or environmental factors. Some of these buildings contain evidence of architectural merits that form part of the national heritage. Documentation of architectural significant buildings is essential and vital for preservation and conservation purposes. Such documentation must be systematic, accurate and true in representing distinctive qualities; and must follow an appropriate procedures.
This paper reviews relevant literature which relates to documentation procedures and tries to apply it to various merited buildings in the city of Basra (1914-1958) when many buildings were built by none-Iraqi architects.
It was evident that no study was conducted to list these buildings, especially the major landmarks in Basra. It sets parameters for methodological documentation and applies to various examples in Basra which was affected by colonial style in this period.
The paper presents,also,various findings relevant to this issue