Al-Khwarizmi Engineering Journal

Specialized hardware implementations of Artificial Neural Networks (ANNs) can offer faster
execution than general-purpose microprocessors by taking advantage of reusable modules, parallel
processes and specialized computational components. Modern high-density Field Programmable Gate
Arrays (FPGAs) offer the required flexibility and fast design-to-implementation time with the
possibility of exploiting highly parallel computations like those required by ANNs in hardware. The
bounded width of the data in FPGA ANNs will add an additional error to the result of the output. This
paper derives the equations of the additional error value that generate from bounded width of the data
and proposed a method to reduce the effect of the error to give an optimal result in the output with a
low cost.

In this work the design and application of a fuzzy logic controller to DC-servomotor is
investigated. The proposed strategy is intended to improve the performance of the original control
system by use of a fuzzy logic controller (FLC) as the motor load changes. Computer simulation
demonstrates that FLC is effective in position control of a DC-servomotor comparing with
conventional one.

Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat
source) located on a printed circuit board are presented. Computational field involves the solution of
elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and
its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept
near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is
cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer
phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this
chip. These parameters, which will help enhance thermal performance of electronic chip and flow
patterns, through the understanding of different factors on flow patterns. The results show the relation
between the temperature rise, heat transfer parameters (Nu, Ra) with (Ar, Q) for two cases of laminar and
turbulent flows.

Rotating blades are the important parts in gas turbines. Hence, an accurate
mathematical estimation (F.E.M) of the stresses and deformations characteristics was
required in the design applications to avoid failure. In recent year’s there are researchers
interest in the effect of temperature on solid bodies has greatly increased, The main of this
study investigated the thermal and rotational effects. So, the thermal stresses due to high
pressure and temperature are studies, also determine the steady state stresses and
deformations of rotating blades due to mechanical effect. Many parameters such as
thickness and centre of rotating are investigated in this paper. The study results can ensure
good recommendation for the effect of the mechanical and thermal stresses of rotary
blades.

A real method of predication brake pad wear ,could lead to substantiol economies of time and money. This paper describes how such a procedure has been used and gives the results to establish is reliability by comparing the predicted wear with that which actually occurs in an existing service. The experimental work was carried out on three different commercial samples ,tested under different operation conditions (speed,load,time...etc)using a test ring especially modified for this purpose. Abrasive wear is mainly studied , since it is the type of wear that takes place in such arrangements. Samples wear tested in presences of sand or mud between the mating surfaces under different operational conditions of speed, load and braking time .Mechanical properties of the pad material samples (hardness, young,s modulus and collapse load under pure bending condition )wear established . The thermal conductivity and surface roughness of the pad material wear also found in order to enable comparison between the surface condition before and after testing. Sliding velocity had a small effect on the wear rate but it had great effect on friction coefficient. Wear rate was affected mainly by the surface temperature which causing a reduction friction coefficient and increasing the wear rate. Surface roughness had almost no effect on the wear rate since it was proved experimentally ,that the surface becomes softer during operation .mechanical properties of the pad material had fluctuating effect on wear rate. The existence of solid particles between pad and disc increasing wear rate and friction coefficient while the mud caused a reduction in wear rate of the pad surface since it acts as a lubricant absorbing the surface heat generated during sliding the area of contact between pad and disc. wear rate obtained experimentally agreed fairly well that found from empirically obtained equations.

Correlation equations for expressing the boiling temperature as direct function of liquid
composition have been tested successfully and applied for predicting azeotropic behavior of
multicomponent mixtures and the kind of azeotrope (minimum, maximum and saddle type) using
modified correlation of Gibbs-Konovalov theorem. Also, the binary and ternary azeotropic point have
been detected experimentally using graphical determination on the basis of experimental binary and
ternary vapor-liquid equilibrium data.
In this study, isobaric vapor-liquid equilibrium for two ternary systems: “1-Propanol – Hexane –
Benzene” and its binaries “1-Propanol – Hexane, Hexane – Benzene and 1-Propanol – Benzene” and the
other ternary system is “Toluene – Cyclohexane – iso-Octane (2,2,4-Trimethyl-Pentane)” and its binaries
“Toluene – Cyclohexane, Cyclohexane – iso-Octane and Toluene – iso-Octane” have been measured at
101.325 KPa. The measurements were made in recirculating equilibrium still with circulation of both the
vapor and liquid phases. The ternary system “1-Propanol – Hexane – Benzene” which contains polar
compound (1-Propanol) and the two binary systems “1-Propanol – Hexane and 1-Propanol – Benzene”
form a minimum azeotrope, the other ternary system and the other binary systems do not form
azeotrope.
All the data passed successfully the test for thermodynamic consistency using McDermott-Ellis
test method (McDermott and Ellis, 1965).
The maximum likelihood principle is developed for the determination of correlations parameters
from binary and ternary vapor-liquid experimental data which provides a mathematical and
computational guarantee of global optimality in parameters estimation for the case where all the
measured variables are subject to errors and the non ideality of both vapor and liquid phases for the
experimental data for the ternary and binary systems have been accounted.
The agreement between prediction and experimental data is good. The exact value should be
determined experimentally by exploring the concentration region indicated by the computed values.