AL-Rafidain Engineering Journal (AREJ)

This study was carried out to determine the influence of the randomly oriented discrete steel fibres on the bearing capacity of plain concrete through testing concentrically loaded 150mm square prisms. The concrete strength, ratio of total area to loaded area, height of prisms, dimensions and fibre percentage were varied throughout the investigation. It was found that the bearing capacity increases with the concrete strength and the ratio of the total to loaded area both for the plain and for the fibrous concrete. It was also found that the bearing capacity of steel fibrous concrete was significantly higher than that of unreinforced concrete, and showed ductile mode of failure and retained their integrity also at failure. It was also found that the bearing capacity of fibrous concrete increases with the aspect ratio of the used fibres. Prediction of the bearing capacity both for the plain and fibrous concrete using the limit theorems of perfect plasticity showed fair agreement with the experimental results.

Abstract The research problem has been determined through the necessity of the architectural elements and determining their relations to one anther with the aim of studying the shifts that have been taken place in Mosul architecture. The research methodology encompasses the application of this frame to buildings that date back to the various stages of architectural change. Consequently, to find out change that have occurred in Mosul architecture elements and the diachronic relations which testify to either continuity or change in it. The research also embraces the method of collecting data on building samples. These include (20) building samples chosen according to objective criteria. Then, a case study on these samples has been applied using a special formula. In Consequence, results relating to the research hypothesis have testified, together with the finding, significant variance between the architectural phases through the changes that have taken place in the architectural elements.

This paper presents a numerical model which is capable of predicting the behavior of fibrous prestressed concrete beams and frames subjected to cyclic loads. The stiffness method with the effective secant stiffness is used here in analyzing plane structures, while the analysis of member cross sections that are subjected to cyclic loads is carried out in combination with the layered section approach. Material nonlinearity has been taken in to consideration through the analysis of these sections. This method deals only with axial forces and bending moments neglecting the effect of shear forces. The study presents a program written with MATLAB language that analyzes structures by the STIFFNESS method and divides the cross sections into small layers in order to utilize the nonlinearity of the stress distribution along the section depth. The results at each section are moments, curvatures, displacements, forces, stresses and strains under each load cycle. A cyclic model for fibrous concrete subjected to uniaxial compression or tension has been proposed. Also the cyclic model of Menegotto and Pinto for conventional and prestressing steel has been adopted. Full bond between steel and concrete is assumed. The study shows that the prestresssing force in concrete members has reduced the ductility or capacity of energy dissipation, while a noticeable increase in the member failure load is recorded. Moreover, the existence of steel fibers in concrete enhances its stiffness, delays the cracks The scheme of and then narrows their openings in tension zone and decreases their negative effect. the layered section presents more reliable stress distribution on the cross section of the concrete members.

This stady deals with the effect of waste from textiles dyeing
operation on the engineering properties of Expansive clayey soil .The tested
soil was obtained from of Al- Yarmook district-Mosul-City, which be
described as light brown stiff clay ,an inorganic type with high plasticity
(CH) , It contains (38%) clay size particles ( d 0.002 mm). The soil was
treated with one Types of industrial waters , Taken from Textile
Manufactories Directorate in Mosul city.
The Results, showed that the industrial waters caused little reduction
in the liquid limit and slight increment in the plastic index. The effect of
industrial waters addition on the compaction characteristics, showed that an
increase in the maximum dry density and decreace of the optimum moisture
content were occured . As well As the industrial waters increased the
unconfined compressive srrength and the shear strength parameters(I ' )
(C ' ).
The study, showed that the swelling percentage and swelling pressure
increase with increasing the concentration of industrial waters. On the
other hand the results of consolidation test showed that the compression
Index (Cc) and coefficient of consolidation ( Cv ) increase as the soil was
treated with industrial waters.

Oxygen transfer capacity has greatest influence on activated sludge performance. In this study, experimental procedure is carried out to determine the effect of airflow rate and the level of diffusers submergence, on the oxygen transfer rate of diffused air systems. In addition, a number of readings were also collected from published papers. The data were selected to cover various scales of plants and operating conditions. After sorting out, all data were treated and then combined to the experimental readings in order to expand the applicability of the results. Individual mathematical models to describe the effect of each parameter were also derived. The results of the study showed that, increasing the airflow rate at fixed water depth and diffusers submergence enlarge the oxygenation capacity of the system. The equation, which controls this relationship, is linear. At diffusers submergence of 4.6 m, the slope of the equation was 11.8. With reduce the depth of diffusers to about 0.4 m; the slope of equation was decrease to 2.3. At constant airflow rate, the depth of diffusers has a significant effect on both of the oxygenation capacity and oxygen transfer efficiency of the system. Exponentional form of equation is shown to be efficient in expressing the relationship between the submergence and the oxygenation capacity. At 0.4 m, diffusers submergence, the oxygen transfer efficiency was 1.8 whereas; this value is rising to about 11.5 at 4.6m submergence.

Longitudinal and radial stresses in a M.V. and H.V. cables through terminals are computed using Schwarz Christoffel transformation for field sketching. The terminals and associated cable are rated at 11KV, 33KV and 132KV a.c insulated by cross–linked polyethylene (XLPE). The electrical field sketching at the cable terminations is carried out theoretically and the results are confirmed by experiments. It seems that the maximum stresses occurs in the cable insulation and the maximum longitudinal stresses along the screened outer surface of the cross-linked polyethylene (XLPE) insulation occurs between the cable and the termination center. The results show that the maximum longitudinal stress is many times the oncorrespding maximum radial values.

In this research thin film layers have been prepared at alternate layers of resistive and dielectric deposited on appropriate substrates to form four – terminal RY- NR network. If the gate of the MOS structures deposited as a strip of resistor film like NiCr, the MOS structure can be analyzed as R-Y-NR network. A method of analysis has been proposed to measure the shunt capacitance and the shunt conductance of certain MOS samples. Matlab program has been used to compute shunt capacitance and shunt conductance at different frequencies. The results computed by this method have been compared with the results obtained by LCR meter method and showed perfect coincident with each other.

Steady free convection through a porous medium around a rectangular isothermal body has been numerically investigated. The isothermal body is kept at constant low temperature and the porous medium has an impermeable rectangular boundaries. The cavity wall of porous material has a constant high temperature. The full governing equations (momentum an energy equation) have been solved for range of values of the governing parameters by using the finite difference method and covered a wide range of modified Rayleigh number (Ra) (0-500) with different sizes of isothermal body. Results are presented in terms of the streamlines and isotherms to show the behavior of the flow and temperature fields. This study shows that the Nusselt number (Nu) is a strong function of the modified Rayleigh number, the isothermal body size and boundary conditions. For certain range of Ra, the rate of heat transfer decreases when the flow divided into primary and secondary cells

frames under C.L The applications of Discrete Wavelet Transform necessitate fast computation. Full-custom VLSI devices (ASIC) have been used for fast though expensive implementations of DWT. Field-Programmable Gate Array (FPGA) architectures offer economical but area-constrained implementation of DWT. The present paper proposes an important issues on the design and simulation of ASIC and FPGA architectures for 1-D DWT as well as inverse DWT on a single chip using VHDL simulation tools. The design of the programmable chip that can be used as 1-D DWT or IDWT is introduced based on two quadrature mirror filters (QMF), one used with DWT (decomposition) and other used with IDWT. The design is modular; the chip can easily be worked as DWT or IDWT with ability of selecting one of the four corresponding types of QMF wavelet filters (Daubechies 1, 2, 3 and 4). The first chip is implemented and simulated using FPGA for two word lengths 8-bit and 12-bit respectively. The results show a clock speed of 66.2 MHz for 8-bit, and 55 MHz for 12-bit. While the design of ASIC chip validate a clock speeds 85.5 MHz and 59.2 MHz for 8-bit and 12-bit respectively. Simulation results have established that the higher word length increase accuracy but at the expense of higher designed size and longest combinational logic between two storage elements. This means increasing the length of critical path as result of complexity which decrease the maximum speed clock.

This paper covers the theoretical and practical evaluation of straining which arise due to stressing, and plastic deformation during the deep drawing process of the production of the shells for LPG cylinders, as well as the process description and application. Therefore the study includes experimental work in the field of metal drawing in stages for different depths to tabulate the radial metal movement and changes in shell thickness and diameter. As the annealing treatment has an important role in the production sequence, so samples of metal used in producing the domestic LPG cylinder were heat treated in different situations to study the influence of an annealing operation on the metal (its microstructure, metallurgical, and mechanical properties