Journal of Engineering

The paper presents further experimental results on the behaviour of reed reinforced concrete joists in flexure. The experiments include the determination of elastic modulus of reeds by pulse velocity method, also additional results are presented on the tensile strength, density, ductility and toughness indices. The results include the effect of asphaltic emulsion paints (Flinkote) on flexural properties. The aim of the work is to develop the uses of reeds in low cost housing due to its low cost and its availability in immense quantities.

The research discusses the relationship between “Identity” as a concept giving the impression of “Unchangeability”, and the concept of “Creativity” giving the impression of “newness”.
It is supposed here that the original work of the architect as “subject”, and designer having his own character and his belonging to his society and nation, will have both the value of Identity and the value of creativity.

This is accomplished by balancing between two levels in the act of making architecture: the level of thought, and the level of physical products, which reveals the relation between Form/Matter.

These two levels are discussed through analyzing three cases:

The case of traditions in architecture in which the act is “imitation”.
The case of modern architecture where we find the act of representing the idea, which could be called the act of design.
The contemporary case in which we are conscious of the demand of accomplishing Identity in the creative work.

The present work deals with an experimental investigation of the effect of surfacing parameters on the final quality of large gear surfacing. This gear forms a vital part of the drive train of the cement furnace at the Iraqi Cement Company. The gear is made of DIN CK 45 steel with an analyzed carbon content of 0.429% and core hardness 185 HV. The gear is considered large, with dimensions of 490 mm in diameter, 250-mm width and 27 mm module, its weight is 350 Kg. The aim of the present work is to study the possibility of repairing this type of gear using SMAW process.

The gear surface is cleaned by sand blasting, followed by dye penetrate testing for crack detections. DIN E1-UM350 hardfacing electrode is selected to hardface the gear. This electrode has a nominal composition (0.08%C, 3.3%Cr, 1%Mn) and a minimum hardness 350 HV. The gear teeth are surfaced with one, two, and three layers with and without preheating. The preheating temperature is 200°C, which is selected according to carbon equivalent of the DIN CK 45 base metal.

Cracks were observed in the weld metals when surfacing with three layers of E1-UM350 electrode. So, E 8018-B2, and E 9018-D1 are selected to butter the gear surface with one layer, followed by two layers of E1-UM350 electrode. These low hydrogen electrodes are selected based on their mechanical properties compared with DIN CK 45 base metal and low hydrogen content which eliminate hydrogen induced cold cracking. Preheating the gear surface gives good hardness distribution across the weld, HAZ, and base metals due to reducing the cooling rates and prevents hard structure to form at the interface region.

A set of destructive and non-destructive tests are carried out, including tensile, wear, impact, chemical analysis, metallographic, micro hardness, macro etchent, and dye penetrate tests. Both of wear and impact resistance of all specimens is greater than the base metal. All weld deposits of E1-UM350 hardfacing electrode gives martensitic structures with different hardnesses depending on the cooling rates and number of layers. Using of low hydrogen electrodes (E 8018-B2 and E 9018-D1) as buttering layers, solve the cracking problem of weld deposits when surfacing with three layers of E1-UM350 electrodes.

This experimental study investigates the reduction of formation damage resulting from drilling muds. Using a bridging system with different barite additions (70, 140, 200, 280 lb/bbl) to fresh water mud, the study aimed to create an effective sealing of impermeable filter cake to inhibit the loss of small solids and mud filtrate into the formation. The findings suggest that while all muds can damage the petrophysical properties of the formation, certain additives can reduce this damage. Furthermore, minimum permeability damage occurs when the particles of drilling mud are larger than the pore size of the formation, preventing internal mud cake creation. It emphasizes the importance of matching particle size distribution in the mud to pore entry size distribution within the rock to reduce impairment and allow each pore entry to be bridged as permitted by the fluid flow rate.

This paper presents a new design concept for a percolator that combines the simultaneous production of ammonia vapor and the pumping of weak aqua-ammonia liquid. The steady-state design was based on a balance between the hydrostatic driving head and the total single and two-phase pressure losses in the percolator system. Modeling of the driving pressure and pressure losses using the separated flow and drift flux methods were compared with experimental measurements. Chisholm's model was found to be the best in predicting the measured flow rate versus water level for the first stage, with a maximum standard deviation of ± 10.1%. Parametric design studies, including cooling power and strong solution level, inner tube diameter, and height for each stage of the percolator, were carried out to maximize the suitable cost function. The results of the optimization gave a two-stage percolator with a length of 280 mm and an inner diameter of 5.5 mm for the first stage, and a length of 520 mm and an inner diameter of 5.5 mm for the second stage.

This study investigates the effect of membrane action on the results of load tests. Two three-dimensional model frames, each consisting of rafts, columns, beams, and slabs, were prepared for load testing. The results show the positive role of membrane action, especially with camber beams and slabs, in successfully passing the load test. There is also an enhancement in the deflection behavior of camber members compared to straight members.

This paper investigates the undrained stability of cohesive slopes subjected to surcharge loads. Problems of this kind are involved in structures rapidly built near the crest of cohesive slopes and heavy equipment (e.g., draglines, bulldozers, and railways) moving on slopes. Using the non-linear finite element method, the effects of line loads and uniformly distributed loads are studied, and the distribution of stresses under these loads is examined. The value of Per (critical line load) required to equate the driving and resisting moments for a unit length of the slope was computed using the computer program. The process was repeated until a minimum Per was obtained.

This paper investigates the estimation of the life of a thick cylinder subjected to internal pressure with manufacturing cracks using the J-integral method. Cracks may appear in structures due to manufacturing processes, and these structures may be used but with a life less than the design life due to crack propagation. The finite element method with the J-integral approach was used to evaluate the numerical strain energy release rate (J) for the thick cylinder and the stress intensity factor (SIF). The J-integral method is the most accurate method to evaluate the SIF for elastic-plastic materials by considering the local plastic zone near the crack tip. A software developed using the FEM, J-integral, SIF, and Paris formula to estimate the life of the component is presented with many working examples.

This paper presents a study on the global buckling load of steel columns strengthened using fiber reinforced polymer (FRP). The research focuses on increasing the load capacity and improving the stability of axially loaded steel columns through the application of FRP. The study involves both theoretical analysis and numerical finite element (FE) analysis. Different types of common commercial FRP systems were examined and used in this study to evaluate their effectiveness in enhancing the structural performance of steel columns.

One of the major advantages of digital photogrammetry is the potential to automate production processes efficiently, thus substantially improving the price/performance ratio for photogrammetric products. Image processing and computer vision techniques have successfully been employed for facilitating automated procedures in digital aerial images such as interior orientation, relative orientation, point transfer in photogrammetric block triangulation, and the generation of DTMS.

In this paper, the researcher presents her investigations on a digital aerial triangulation of a block consisting of two strips of eight aerial photographs. Digital image data scanned with a resolution of 400 dpi gives a pixel size of 63.5 µm (corresponding to 0.19m ground resolution). Each one of the eight black-and-white overlapped aerial photographs used in this research has a photo scale of approximately 1:3000. The measurements were carried out using a Pentium III personal computer with a 733MHz CPU, 128MB memory, and a 20GB hard disk. All observations were later adjusted using a bundle adjustment program (jadria) written by the researcher herself.

The goal of this research is to build a digital aerial triangulation package for Iraqi Universities.

This paper will present the success of using the World Wide Web as a platform for electronic commerce and explain the necessary security mechanisms for it. Also, we will propose a new approach for dealing with pre and post-sales support activities by using electronic media as integral and very important parts of the business process that can be implemented in Iraqi small and medium enterprises.

An investigation has been made into the effect of residual stresses on the vibration characteristics of thin rectangular plates elastically restrained against rotation along three edges and free on the fourth edge. General frequency equation with and without including the effect of residual stresses has been obtained. Exact frequency expressions including the effect of residual stresses for the cases: S-S-S-F, S-S-C-F, C-C-S-F, C-S-S-F, C-S-C-F, C-C-C-F were also obtained. The effect of the position of welding along the width of the plate for all cases was also included. Actual plate models were tested and the results were compared with the theoretical predictions giving good agreement.

the effects of using a solution of ethanol and gas-oil (dual fuel) as fuel for a diesel engine on engine performance and heat release. A single-cylinder diesel engine type Recardo (E6/US) was used, and the ethanol percentage in the solution was varied from 0 to 20 percent. The results indicated that adding ethanol to gas-oil generally caused a decrease in maximum power output at medium and high-speed ranges, making it nearly the same as that of straight gas-oil at low-speed ranges. The specific fuel consumption of the dual fuel was nearly the same as that of straight gas-oil at low and medium load ranges but increased at high load ranges. Additionally, the inclusion of ethanol increased the maximum rate of heat release during the first stage of combustion and decreased it during the second stage. Further substitution of gas-oil with ethanol beyond 20 percent was limited by knocking.

The aesthetic and architectural shapes of the beam-column elements may enhance the elements strength depending on the maximum and minimum bending moments effect. Therefore, the stability value of the non-linear taper member in concave configuration may be more efficient than linear taper or prismatic members.

The modified stability functions will be obtained from the solution of the basic differential equation, where this basic differential equation depends on the non-linearity factor (λ) of the beam-column shape and the shape factor of the cross-sectional area. These two factors, multiplied by others, produce the modified shape factor, which affects the results of the basic differential equation solutions.

The sealing effects of a squeeze air film were analyzed both experimentally and theoretically. The air flow rate and the sealed pressure were measured in a squeeze face seal. The air flow rate is expressed as the difference between the flow rate by the pumping and the flow rate by the leakage. The air flow rate by the pumping increases proportionally to the square of the vibration amplitude of the surface, as does the sealed pressure. The air flow rate by the leakage increases proportionally to the pressure difference between the vessel pressure and the ambient pressure. The experimental results showed good agreement with the theoretical results.

the thermal behavior of an octagonal shell orbiting body in space environments. The study includes theoretical simulations and experimental tests in a thermal vacuum chamber. A mathematical model was built and simulated using a lumped system technique and finite difference control volume approach with explicit scheme. The body in its orbit around the Earth receives solar, albedo, and Earth radiation heat fluxes. The orbit is circular with a height of 500 km and an inclination of 40 degrees. The computational algorithm calculates heat fluxes on body faces and the temperature distribution of the body at any time instant. The results show that heat fluxes are maximum when the orbit inclination is minimum and vice versa. Heat fluxes are maximum in winter solstice and minimum in summer solstice. The emissivity affects body temperatures more than absorptivity. The comparison between theoretical and experimental results showed good agreement.

Myoelectric signals are the electrical manifestations associated with the movements exerted by the muscular system in mammals, including humans. The examination of these signals can reveal the status of the muscles and the driving nervous system. This is important for diagnosis, prosthesis, and aids for handicapped individuals. Powerful digital processing techniques are necessary to analyze these signals. This paper investigates several techniques to extract features of myoelectric signals in both time and frequency domains. These extracted features are used in an automatic diagnostic classification system to determine if they correspond to a normal muscle.

In this paper, Wavelet-Network (WN) model has been recently proposed and applied to image processing, e.g., identification type of noise in Gray-Scale Images (GSI). This paper develops a new technique, which employs a Discrete Wavelet Transform (DWT) and an Artificial Neural Network (ANN). This WN technique uses special mother wavelet ψ(x1, x2) of (DWT) as activation function for (ANN) instead of the traditional activation functions like (Log sigmoid, Tan sigmoid, etc). It is shown here that the benefit of WN circuits which uses WN is a good approximation tool for GSI images. These approximation patterns for images forced ANN to learn on these images which will be used in the test phase after that.