Engineering and Technology Journal

Machining of electrically non-conducting materials like glass is still a major
problem. The principle of electric arc was used to generate high electrical discharge
(spark) at high currents to machine non-conducting materials at any hardness, which
is a new approach.
EDM system was build for machining of non-conducting cutting materials such
as glass with new technology including the use of powder (graphite) mixed for
dielectric solution (tap water) by supplied AC current values (200, 250, 300, 350 and
400A). Voltage of (70V) was used to cut 3mm thickness of borosilicate glass (BSG)
to obtain the average surface roughness (Ra) of about (0.003-0.012μm) but the Ra
before the machining was (0.005-0.006μm).
Numerical program called "Simulent" has been used to investigate the process
control for EDM by using GN, BPN, PN and VQN that could predict the Ra with
accuracies of 94.236, 94.034, 96.628 and 92.875% respectively from training data
sets.
The differences on the Ra at different network models for 3mm thickness of BSG
never exceed (8%) from testing data sets while the comparison of numerical results
with experimental results of Ra among the measured values and prediction various
network models, shows a differences between (1-8%).
The best predication accuracy is by the use of PN than other network models

The present work is dealing with the modeling, investigations, and controlling, of
a prototype radial magnetic bearing system. Considerations based on the 8 poles model
with switched mode power supply. Investigations of radial forces in two axes model and
performance response are carried out through the intelligent controller system.
Improving system response is achieved by using an efficient controller based Neural
Network (NN) NARMA-L2 Controller together with the conventional PID controller.
The response is presented for stand still and dynamic conditions using the implemented
Simulink software. The results show that the NARMA-L2 is highly improved the
dynamic response of the speeding up rotor in comparison with the conventional
controller.

The proposed system is based on embedded the heuristic search in DNA search
algorithm so to make it more efficient and flexible. The HDNA system is constructed to
improve the work of the DNA computing algorithm and enhance the measurement
criteria of it by reducing the run time and the memory capacity as well as the number of
generated random solutions (strands or states) that are needed to implement the
computing algorithm. The experimental results appear that the HDNA using A* and
Alpha-Beta is more efficient than using A* and Alpha-Beta each alone.

In this paper adiabatic flow in capillary tube is analyzed and modeled for R-22 and
alternative R-407C. The equations of continuity, energy and pressure drop through a
capillary tube are presented. A mathematical model of sub–cooled flow region and
two–phase flow region is developed. The results of the calculation compared with
experimental data presented in the technical literature will be shown in the present
article in order to validate the model developed. This numerical model is capable of
providing an effective means to analyze capillary tube performance to optimize and
control an R – 22 and R – 407C in an air – conditioning systems

The present work is designed to study the parameters interaction of sterilization
processes in batch bioreactors (fermentors of volume 120 liter with medium of 56784 kg).
he parameters include the effects of sterilization temperatures (117-126
o
C), time of
heating, time of holding, and time of cooling on removal of all organisms, and degradation
degree of medium. Direct steam was used for heating at different temperatures ranged
from120
o
C to 180
o
C. The B.Stearothermophilus was selected as the present contaminants.
Another bioreactor of volume (56828) liter was studied at 121
o
C for the same contaminant
and compared with actual data.
This study is achieved by designed procedure and simulation program useful for
the optimization of batch sterilization cycle in large-scale fermentors. The method of
optimization used is Genetic Algorithm(GAs) which uses probability to find the optimum
condition for the sterilization cycle and to find Del factor; which is the reduction value of
initial to final number of microorganisms, and then evaluate the cost which depend on
amount of steam consumed in the sterilization processes
Graphical relations was indicated that as fermentor size increase, the time of
heating also increase. For low temperature the time of holding was increased and for high
temperature the time of holding was decreased. Also these relations were investigated the
best conditions between holding time and Del factor for degradation at different
temperatures

The new schiff base complex: Chloro- (bis (salicylaldehyde) ethylene diiminato)
aqua manganese (III) is synthesized and characterized. It is used as thermal initiation in
radical polymerization of styrene at 80 c◦ in dark without inhibition and retardation
complication, and the rate of polymerization is directly proportional to the squre root of
initiator concentration [I]1/2 . gravimetry technique is used for deteremination of the rate
polymerization, and viscometery is used for determination of average of polymerization.
The uv- visble spectrophotometry is used to determine the rate constant of initiator
decomposition (ka). The value of the kinetic parameter ratio kp / kt
1/2 (Where kp & kt
are the rate constants, propagation and termination respectively).

A simulation study of an IEEE 802.11b which is the most important standard for
wireless local area networks was presented in this paper. The simulation is conducted using
OPNET IT Guru Academic Edition 9.1. Wireless network performance depends mainly on
the end to end throughput and average delay. Different applications place different
requirements on the network. Thus, it is necessary to evaluate and analysis the performance
of IEEE 802.11b WLAN system under the fundamental access mechanism for medium
access control (MAC) called distributed coordination function (DCF).This can achieve by
studying the impact of parameters such as Request to Send/ Clear to Send (RTS/CTS),
Fragmentation Threshold (FTS) and discuss the best configurations and parameters value in
correspondence to network load and topology to get best performance which is the main
objective of this paper

The Two-dimension ramp inlet flow field was studied with typical mode operations.
Euler equations were used for solution with no special treatment required. In this work a
solution algorithm based on finite difference MacCormack’s technique was developed to
solve mixed subsonic-supersonic flow problem through the external shock diffusers
(ramp inlet) and it is found to be converge for supercritical and critical inlet operation

Because the network is an open environment, a lot of care must be taken when
transferring sensitive information especially when related with financial data. This depends
on the principals to be trusted which is a problematic and since the first step in network
security is the authentication, this paper presents a proposed modal for secure mobile
banking (m-banking) applications using Kerberos (the network authentication protocol).
The aim of this paper is to establish a secure communication between the clients and
mobile-bank application server in which they can use their mobile phone to securely access
their bank accounts, make and receive payments, and check their balances.
The integration of smart card into classic Kerberos enhances the security for client
authentication by storing the cryptographic keys and perform dual factor authentication.
Other enhancement to Kerberos is the PKINIT in which the shared key is mapped with
public- private key. To build a robust client authentication the client uses his/her mobile
phone to author Kerberos's messages, process the replay and establish secure
communication with the application server.

Absorption of carbon dioxide from gaseous mixture (carbon dioxide, air) was
studied by using Carbonate Solution (Na2CO3) in a counter-current packed column (7.5 cm
id, 1.70 m height), packed with glass rashing rings of 1.8 cm i.d to a depth of 1.1 m.
The effect of Surfactant concentration (dodecyl benzene sulfuric acid sodium
(DBS))(0.5, 1.5, 2.5gm/lit.), gas mass flux (0.05, 0.075, 0.1 kg/m2.sec) and liquid mass flux
(kg/m2.sec) on the absorption rate of carbon dioxide and mass transfer coefficient was
studied at constant carbonate concentration (0.3 kmol/m3), inlet carbon dioxide
concentration(0.08, Y2=0.086 mol CO2/mol air), ambient temperature and atmospheric
pressure. The results show that the absorption rate tends to increase with increasing gas and
liquid flow rate. Mass transfer coefficient (KG.a) increases with increasing liquid flow rate
and slightly change with increasing gas flow rate. Increasing surfactant concentration
(decreasing surface tension) leads to decrease the absorption rate and mass transfer
coefficient.

AbstractT
aguchi method is a problem – solving tool which can improve the performance
of the product, process design and system. This method combines the experimental and
analytical concepts to determine the most influential parameter on the result response for
the significant improvement in the overall performance. In this research Al–Si /Al2O3
composites was prepared by vortex technique using three different parameters, stirring
time, stirring speed, and volume fraction of the reinforcement particles. A tensile and
hardness tests were done for the resulted castings. The primary objective is to use
Taguchi method for predicting the better parameters that give the highest tensile strength
and hardness to the castings, and then preparing composites at these parameters and
comparing them with the randomly used once. The experimental and analytical results
showed that the Taguchi method was successful in predicting the parameters that give
the highest properties and the volume fraction was the most influential parameter on the
tensile strength and hardness results of castings

The effect of laser surface heat treatment on wear resistance of 100Cr6 steel was
investigated. In this work, 100Cr6 steel which is widely used in many industrial of automobiles
hardened by using Nd: glass laser (l=1.060mm, t=300ms). Three different laser energies have been
used to perform hardening (0.3, 0.58 and 0.93 Joule). A pin-on-disc technique has been used to
evaluate wear rate of the specimens as-received and specimens treated by Nd: glass laser at
different applied loads and different sliding speeds with 420 r.p.m and 45 HRC of rotating
disc. The results show that the wear rate increases with increasing applied load and decreases with
increasing sliding speed, wear rate for laser energy 0.93 J less than another energies 0.3 and 0.5 J.
Also the microhardness decreases with increasing in depth of hardening, and the microhardness
for laser energy 0.93 J more than another energies for the same depth.

There are wide variety of mechanisms available for performing the authentication
function. One of them is by using video film to monitor important places. In such systems
the important task is recognizing human faces which need good segmentation and high
feature extraction. In traditional technique the segmentation can be performed by region
growing and shrinking, clustering method, and boundary detection which all take image
pixel by pixel and compare each with neighbors to get the similarity. Chaotic oscillator
depends on synchronization concept between points to determine the active points which
construct similar region determining the object. Then RGB color space is used to determine
skin color pixel. Skin color model aids the process of separating the face from the scene due
to its skin color. After isolating the human face image which contains many features (eye,
eyebrow, nose, etc...) they identify the person. Chaotic oscillator is used to extract the
important features by removing any point that is not synchronized with its neighbors and
gives new image which contains only the main face features and then compare this image
with stored image in Database of authorized person and make decision on if (he/she) is an
authenticated image or not.

Structural and optical property was studied as a function of film thickness for
thermally evaporated CdI2 films. Stoichiometric films (up to 250 nm thickness) showing
hexagonal structure, and good c-axis alignment normal to glass substrate plane. The
optical absorption data indicate an allowed direct inter – band transition near the
absorption edge with optical energy gap varies continuously from 2.9 eV to 3.6 eV.Part
of the optical data was fitted to an indirect type transition to determine the indirect optical
energy gap which also varies continuously from 2.2 eV to 3.1 eV . Both energy gaps
show thickness dependences, which can be explained qualitatively by a thickness
dependence of the grain size through the decreasing of the grain boundary barrier height
with grain size.

This paper is concerned with hiding secret data in audio media file (.WAV). When
performing data hiding in audio, one must exploit the weaknesses of Human Auditory System
(HAS), while at the same time being a ware of the extreme sensitivity of this system. This
hiding method is oriented to embed the secret data such that it is capable of surviving against
modifications produced by MP3 compression standard. Statistical and analytical
investigations are performed to assess the variations which may occur in the WAVE audio
when it is subjected to MP3 compression. Features of speech signal are exploited (Voiced-
Unvoiced segments) for embedding the secret data. Hiding is attempt by shortening or
elongating the unvoiced blocks of audio file (cover) data. To support the immunity of the
proposed hiding system, an encryption method is added to the proposed hiding system

The mechanical properties and the morphology of the ternary blend of
LDPE/LLDPE/HDPE were studied.
In the present work LDPE was mixed with equal amount of LLDPE and different
wt% of HDPE (0, 10, 20 and 30 %) using the two roll mills. The mechanical properties
and the morphology were specified by measuring the (tensile, hardness, impact
properties) for the former, and photomicrograph for the later. From the tensile test
results it was found that the tensile strength at break of the ternary blend increased with
increasing the HDPE contain also the increases of wt% HDPE leads to decrease the
elongation at break. For the hardness test it was found that the shore hardness of the
ternary blends increased with the increasing the HDPE contain .On the other hand the
impact test carried out also and it was found that the addition of HDPE leads to
decrease the impact strength . Nevertheless, optical micrograph results that the HDPE
serves as a compatabilizing agent for immiscible LDPE/LLDPE

Self-Compacting Concrete is considered one of most remarkable developments in
concrete technology. It is a new type of high performance concrete with the ability of
flowing under its own weight and without the need of vibrations. Recently, a great native
interest had been derived towards self-compacting concrete.
This work aims to present a summary study about properties of fresh selfcompacting
concrete depending on the results obtained by some native researches, thus
focusing on the main common features between their results. It had been focused on the
effect of type and proportions of constituent materials incorporated in producing selfcompacting
concrete. This considered the most influential factors in controlling its
properties

This study presents on experimental method to investigate the behavior of
reinforced porcelinite concrete columns subjected to concentric load. The experimental
work includes investigation of ten lightweight concrete columns with square cross
section 190×190mm and 1000mm in length subjected to concentric load to assess the
effect of the amount of longitudinal steel reinforcement, lateral tie reinforcement and
grade of concrete. From the experimental observation it was found that the porcelinite
aggregate is a good structural material to produce lightweight concrete columns. It is
noted from tested columns that keeping the amount of the longitudinal steel ratio
constant, the increase in the amount of transverse steel to about four times (by
decreasing the spacing to about a quarter according to the ACI-Code (318M-05)) gave a
significant influence on column post-cracking behavior. The improvements in the
column due to higher value of confinement include: (i) less brittle behavior; (ii)
significantly less damage to the concrete core; (iii) 12% increase in column load
carrying capacity. Also, A modified formula for column capacity is proposed to take
into account the influence of spacing of ties (effect of confinement).

This research is devoted to study the effect of different percentage of Graphite
particles addition (5,10,15) wt% to Brass alloy (α) produced by stir casting using vortex
technique , on the wear resistance and the coefficient of friction under dry sliding
conditions using pin-on-disk technique . Three loads (5, 10, 15) N were used at different
sliding speeds effect (2.7,3.7,4.7) m/sec . The results showed that the wear rate is
increased in general with increasing the applied load , but the composite material
reinforced with graphite particles showed wear rate lower than that of the base alloy .The
wear resistance of the composite material reinforced with graphite particles with 15 wt%
was higher than that of reinforced with 5 wt% . When different sliding speeds were used
, the results showed that , the wear rate is decreased with increasing sliding speed .When
the coefficients of friction was measured at high loads , It is clear that the composite
material has low coefficient of friction as compared with that at low loads , while it is
decreased with increasing sliding distance at all used loads , and the composite material
reinforced with graphite particles showed remarkable decreasing in temperature when
surface temperatures were measured as compared with base alloy.