Engineering and Technology Journal

The undertaken research deals with an experimental determination of drag
coefficient for five car models. Experiments were run within a subsonic aspiration
wind tunnel, covering an air speed up to 33m/s.Drag coefficients of 0.45, 0.39, 0.53,
0.34 and 0.68 for Mercedes SEL300, Hyundai, Toyota, Pajero, and Mini-Bus models
were obtained respectively.
The flow field around the pre-quoted models with a qualitative description about
the flow visualization for car models using a subsonic smoke wind tunnel has been
accomplished

Silver nanoparticles were synthesized by pulsed laser ablation (Q-switched
Nd:YAG, λ=1064nm, 10 ns pulse duration and E=100-900 mJ) of pure Ag metal
plate immersed in double distilled and deionised water DDDW. Spectral
measurements, such as surface plasmon extinction SPE spectra of the produced
nanoparticles solution were measured. The size and concentrations measurements
of produced nanoparticles were estimated. UV-VIS absorption spectra of produced
solution show a sharp peak around 400 nm, indicating the produced Ag
nanoparticles with a narrow size ranging from 5 to 50 nm with almost spherical
shape.

This paper describes the synthesis of a new derivative 3-(1,3-
benzothiazol-2-yl)- /4H- spiro[indole2,3-[1,3]thiazolidine]-2,/4(1H) dion [L],
which have been obtained from the cyclization of 3-(benzo [d] thiazol-2-
ylimino) indolin -2-one[AB] through the addition of α-mercapto acetic acid.
The product [L] was characterized by (FT.IR) and (U.Vis) spectroscopy and in
addition to element analysis (C.H.N.S.).
A number of metal complexes were synthesized from the reaction of
the ligand [L] with ions Cr (III), Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) .
The prepared complexes were isolated and characterized by using (FT.IR) and
(U.Vis) spectroscopy in addition to element analysis (C.H.N.S.), flame atomic
absorption technique, in addition to magnetic susceptibility and conductivity
measurement.
The antibacterial activity of the ligand [L] and its complexes were studied
against two selected micro-organisms (Pseudonomous aerugionosa) as gram
negative and (Bacillus subtitis) as gram positive

Deep excavation is very important problem in geotechnical engineering and use in
construction of tunnel and underground structure. This paper study the deep
excavation using Plaxis V8.2 engineering program and simulation the soil behavior
by Hardening soil model (HSM) that very sensitive to descript the stress path of deep
excavation and the model distinguishes between loading and unloading stiffness
compares to The Mohr-Coulomb Model (MCM). The parametric study adopt the
variation of sand density (loose, medium, and dense), and excavation width (B = 10,
20, 40, 60, and 80 m).
The result conclusions this parameter it's very important on horizontal wall
deflection, bending moment of wall, interface stress between soil and wall, heave,
and settlement of near ground surface, to make the deep excavation and don’t failure
and reduce of on horizontal wall deflection, bending moment of wall, heave and
settlements of near surface and contort on the near building to attainment the safe
design and easy construction with optimum dimensions.

In this work, numerical investigations are conducted for diesel spray under
evaporating conditions. The Eulerian-Eulerian framework of evaporating turbulent
spray is presented in terms of the methodology of spray moments of drop size
distribution. Turbulence effects on mass and heat transfer in evaporation test case are
presented. The simulated results showed that the turbulence intensity decreases with
the development of spray under hydrodynamic changes. The simulation shows good
agreement with the experimental results illustrated by comparison of spray tip
penetration elevations.

The Finite element and the finite difference methods were applied to a confined
flow over a cylinder. The values of velocity potential (F), the stream function (Y)
and the velocity distribution are calculated by using a computer programs achieved
by the researcher. The results revealed that, convergence and divergence were
achieved between the equipotential lines by two methods. The finite element method
has been shown to be a powerful tool. Small elements may be used in areas of rapid
change and large elements may be used where variations are less severe. The
boundary conditions are handled naturally by the finite element method in contrast to
the finite difference method.
This study shows that the finite element method is the best technique for the
solution of practical engineering problems like thermal and fluid flows (steady state
or unsteady problems).

The geometrical analysis of the robotic mechanisms means the formulation of the
position equation of the mechanism in terms of dependent and independent coordinates.
This function should describe the position of its links and the end effecter (or moving
platform center) in terms of dependent and independent coordinates.
In this paper will be derived a mathematical model, that is, a model in terms of
dependent and independent generalized coordinates, for the position accuracy of the end
effecter (platform) of the closed kinematics robotic mechanisms. In these types of
mechanisms it is necessary to solve the inverse problem of the geometrical analysis. The
solving of the inverse problem in the robotic systems means the definition of independent
coordinates on preset values and evaluation of the dependent coordinates with several
degrees of mobility.
The aim of this paper is to obtain a new mathematical formulation for evaluation of
the deviation of the end effecter position due to the deviation of the independent
coordinates. It will be evaluated only the deformations of the arms caused by the weights
and the forces.

Abstract
Sand filtration has been an effective wastewater treatment process for control of
contaminates. Sand filters are very economic treatment and do not need constant
operator attention, making them an appropriate technology for wastewater systems
either they are big or small. Iraq has combined wastewater systems (domestic and
storm) water, old treatment plants with very determinate characteristics of influent
(suspended solids S.S equal to 350 mg/L), increasing population and absence of
industrial water treatment units; all these conditions lead to problems of overflow, bypass
wastewater and effluent which have characteristics under what are required.
The results of this paper demonstrate that 76% removal efficiency (R.E) for S.S.
can be achieved by using sand filtration technique.
The best position of sand filter is in 2nd stage (pretreatment) because of the
highest R.E of S.S. High possibility to contaminate filter in 1st because of oils and
floating materials makes this position not good in spite of high R.E. As a result of
this position, effluent will be very low contaminate (s.s reaches 5-10 ppm). In oppose
to ordinary effluent which has 69 ppm of s.s ( according to international
environmental standards , effluent's s.s should be 35 ppm or less and according to
Iraq E.S effluent's s.s should be 60 ppm or less ) .No desirable change in s.s
concentration Is noticed with different sand thickness.
Sand filtration appears unexpectable ability (approximately 50%) to remove iron
and toxic cadmium

The main objective of this study was to evaluate the microbiologically
influenced corrosion of carbon steel in water, samples of water taken from Al-Hilla
rivers and distill water (control medium ). Corrosion analyses by using (Liner
polarization tafel test; weight loss method ; microstructure examination , surface
roughness test and X-Ray diffraction analysis) and microbiological analyses by using
(Isolation and identification by using appearance factors microscopic ,culturing
factors and biochemical tests for biofilm of corrosion product) are used in this study.
The result of corrosion analyses shows the corrosion rates of carbon steel in
rivers water are more than that in control water, the microstructure examination and
surface roughness tests show increase in roughness of met.al. surfaces which are
under the corrosion medium (rivers water) compared with control medium. The result
of microbiological analyses shows the slides that made from the biofilm (product of
corrosion) under microscopic appear small bacilli negative gram strain (G-ve)
bacteria, where as culturing test shows small colonies with 2.5μm in diameter of
bacteria have mucin appearance and green pigments as well as the result from
biochemical tests; these facts indicate that Pseudomonas aeruginosa bacteria are
correlated with the type of corrosion occurring in the carbon steel in the rivers water.

At present, information is being communicated and proceeds automatically on a
large scale. Hence, the required measures for secure storage and transporting of the
information are increased. The protection of the information is necessary to guard
economic interests, to prevent fraud, to guarantee the privacy of the citizen, etc.
In this paper, a new steganographic system with high capacity is proposed.
The proposed algorithm chooses wavelet transform techniques for embedding to
achieve a robust system. The main idea of the proposed system is called the wavelet
based fusion. In this method, the wavelet decomposition of the cover image and the
secret image are merged into a single result called stego-image.

In this paper, a design of optical filters based on single mode-multimode-single
mode fiber structure (SMS) is demonstrated. The multimode interference effect can
be utilized to design wavelength-selective devices with high extinction ratio. The
proposed optical filters are realized by using standard optical fibers.
Two optical filters are designed to operate with wave division multiplexing
(WDM) communication system in two channels at wavelength of 1310 nm and 1550
nm. First filter has power transmission of -0.253/-35 dBm at wavelengths of
1310/1550 nm respectively while, second one has power transmission of -32 / -1.35
dBm at wavelengths of 1310 /1550 nm respectively. In addition, power transmission
curves, spectral response curves, and propagation field of SMS structure in two and
three dimensions are plotted

The measurements and calculations of monolayer and multilayer reflectance, made of
porous silicon films, have been carried out. The multilayer component has been made of
porous silicon layers that has refractive indices of nA=2.16 and nB= 1.55. The band
structure of one dimensional photonic crystal has been calculated using the transfer
matrix method which consists of alternative layers of two dielectric materials A and B.
As for the multi layers component which are consist of the periodical repetition of two
layers of different refractive indices (nH and nL) which has an omnidirectional photonic
band gap (PBG), the width of which depends on the incidence medium and on the
refractive index ratio nH/nL. In porous silicon, this ratio is limited by the material and
fabrication characteristics. Theoretical and experimental study has been carried on the
wide range of practical fabrication parameters for the formation of omnidirectional PBG.
A band width of 400 nm is corresponding to a reflectivity higher than 97% which is
suitable for applications of omnidirectional PBG at wavelength 1550 nm

Corrosion behavior of aluminum matrix composites (MMCs) with (10, 20 &30)
weight fraction of each alumina and silicon carbide was investigated in 10% (NaCl,
NaOH &HCl) solutions at different temperatures (40, 60, 80 &100) °C also at room
temperature. The results showed the corrosion rate was increased with increasing in
weight fraction of alumina and silica as reinforcement due to discontinues protective
film in addition to increasing in temperatures at 10 % HCl solution, it reached (8.252
mpy) by reinforced with SiC. Alumina was exhibited corrosion resistant better than
SiC due to it is insulator; galvanic corrosion occurs when incorporation of
semiconductor SiC only. Specimens were exposed to NaOH solution, aluminum
reinforced with Al2O3 and SiC appears poor corrosion resistance. Finally, the results
of effect NaCl were investigated, appeared an increase in corrosion rate with
increasing in time

In this work, a theoretical study of linear profile for graded antireflection coating
has been used with silicon as substrate. A computer program has been designated
using the basic equations of thin film, and the reflectance has been obtained over a
wide range of wavelengths (400-1000 nm) as well as incident angles (0-60 degree)
for many film thicknesses. The film consist of hydrogenated nitrides, it was shown
that the reflectance decreases as the thin film thickness increases. The reflectance
reaches to less than 1% for thin film thickness 0.6 μm

The article contains the results of the efficiency research of vortex dispersing
countercurrent mass exchange device performance. There are recommendations given
on the basis of analysis of liquid jet and liquid drops movement to assess the mass
exchange surface. Processes and Equipment of Chemical and Petroleum Refineries
Department of Sumy State University has carried out a great research to design new
constructions of vortex mass exchanged devices with countercurrent flow of gas and
drop flows.

The article contains the results of the efficiency research of vortex dispersing
countercurrent mass exchange device performance. There are recommendations given
on the basis of analysis of liquid jet and liquid drops movement to assess the mass
exchange surface. Processes and Equipment of Chemical and Petroleum Refineries
Department of Sumy State University has carried out a great research to design new
constructions of vortex mass exchanged devices with countercurrent flow of gas and
drop flows.

The present paper investigates the possibility of using reed and /or asphalt as
stabilizing materials for ballast model embankment overlaying a bed of soft soil. Four
model tests were performed consisting of a model embankment 500mm base width
300mm crest width and 75mm high. The embankment was constructed on a bed of
saturated soft clay 500mm thick with undrained shear strength 16 kPa. The ballast
embankment was gradually loaded up to failure by a model footing 200mm wide and
400mm long placed on the crest with continuous monitoring of the generated
settlement. The use reed and/or asphalt along the interface surface between the ballast
embankment and the soft soil demonstrated significant improvements in both load
carrying capacity and reduction in settlement.

This paper presents an effective method for improving the performance of
speaker identification system based on schemes combines the multi
resolution properly of the wavelet transform and radial basis function neural
net works (RBFNN), evaluated its performance by comparing the results
with other method. The input speech signal is decomposed into L sub band.
To capture the characteristic of the vocal tract, the liner prediction code of
each (including the linear predictive code (LPC) for full band) are calculated.
The radial basis function neural network (RBFNN) approach is used for
matching purpose.
Experimental results shows that the speaker identification using the methods
achieve (combines the wavelet and RBFNN) give (100%) identification rate
and higher identification rate compared with multi band liner predictive
code, in this paper used Matlab program to prove the results

In this research we use both High Density Polyethylene (HDPE), and Low
Density Polyethylene (LDPE)were used as matrix to the composite material and fish
shell particles were used as a reinforced filler, Plunger injection molding method
were used to prepare samples which have different filler percentage as below:-
1. Pure High Density Polyethylene (HDPE).
2. Pure Low Density Polyethylene (LDPE).
3. High Density Polyethylene (HDPE) reinforced with fish shell particles in the
following percentage (30, 40 and 50%).
4. Low Density Polyethylene (LDPE) reinforced with fish shell particles in the
following percentage (30, 40 and 50%).
In this research some of the mechanical properties (Modulus of elasticity, Impact
strength, Hardness, and Creep rate). The research results showed that the values of
(Modulus of elasticity, Hardness) will increase with the increase of the filler
percentage for both types of polyethylene used in this research, in the other hand the
values for impact strength and the values of Creep rate of the all samples used in this
research will be decreeing with the increase of the filler percentage

In this paper a program was build by (C#2008) programming language to calculate a
dimensional change in specimens of low carbon steel during solid carburizing process.
The chemical composition, mechanical properties and microstructure for all specimens
was the same. Carburizing process was done in different temperatures ( 850 , 900 and
950 ) oC for holding times of ( 3 , 6 and 8 hours ) respectively flowed by normalizing ,
quenching and tempering to improve mechanical and microstructure properties. The
specimens was measured dimensionally with high accuracy before and after mentioned
above heat treatments processes to identify the change in dimensions due to change in
phases of the surface layer of metals during martenstic transformation. Briefly this work
is useful in determining the right dimensions of parts before applying heat treatments to
obtain the final desired dimension of the final product.

In this research we prepared copper oxide thin films by Spray pyrolysis method with
various salts such as ( acetate, nitrate & copper chloride (0.1 M) and study its structural
and optical properties.
Laser technique has been used to determine the thickness of thin films, The structure
characterization of the film was carried out with XRD. The results of XRD show that all
samples have a polycrystalline , Optical properties has been measured by using
spectrophotometer . The absorption coefficient was (1.723*105- 1.936*105 cm-1) at ( 380
nm ) according to the kind of salt, and (1.81*104 – 1.748*103 cm-1) at ( 900 nm ). The
energy gap for direct allowed transition was ranged (2.05 eV– 2.65 eV).