Al-Qadisiyah Journal for Engineering Sciences

This work examines the characteristics of combustion, performance and emissions of single cylinder diesel
engine powered by diesel fuel and a different volume percentages of the caster methyl ester (CME). The
selected biodiesel is studied numerically using the simulation program diesel-rk. The results reported that
peak pressure is closer to the top dead center (TDC), as the percentage of CME. The brake specific fuel
consumption (BSFC) is increased slightly as the blending of biodiesel is increased. All the selected biodiesel
ratios are found to release higher NOx emission compared to diesel. Dramatic reduction in smoke levels
15.25 %, 35.3 %, 40.7 %, 45.71 %, 49.43 %, and 52.73 % with B10% CME, B20% CME, B30% CME,
B50% CME, B70% CME and B100% CME respectively. B20% CME biodiesel was the best remarked ratio
which gives slight variations in performance with a good reduction in the carbon emissions compared to
diesel fuel. The results are compared with other researchers work and nice convergence is observed.

The present study was conducted to monitor the quality of leachate generated from solid waste landfills
operated under different mode over a period of 335 days using a bench scale lysimeters. Sixty six kg waste
sample reflecting the typical municipal solid waste (MSW) streams generated in Al-Diwaniyah city open
dump was used to fill both sanitary and bioreactor lysimeters to study the influence of leachate recirculation
on quality of leachate in landfills located in semi-arid areas. Leachate quality is frequently monitored in
terms of pH, electrical conductivity (EC), chemical oxygen demand (COD), chloride, and total Kjeldahl
nitrogen (TKN). The results show that pH and electrical conductivity values were clearly fluctuated in the
rainy season, while in the dry season the values tend to decrease steadily with a close correlation between
the chloride and electrical conductivity parameters. The study reveals that bioreactor landfill with leachate
recirculation appears to be the most effective option in the removal of organic matter by 98% removal
efficiency compared with 58% removal efficiency in a sanitary landfill. The main difference between
recirculation and non-recirculation options is determined through leachate quality.

Recently, the light metallic interaction of nanostructures has grown to be an area of intensive care research
due to advances in modern fabrication techniques. Unique effects have been observed in a nanostructure,
and their applications have been found in various areas like in the manipulation of light on the nanometer
scale. In this paper Nanoantenna has been introduced and invetigated by studing the effect of changing its
parameters such as (shape, length, thickness, and the gap distance between two nanostructures) on the
response of the nanoantenna (far field directivity, optical resonance frequency, and S-parameter). Here, a
bow tie antenna has been chosen and additional parameters have been considered in the simulation, such as
antenna thickness and material, and substrate material . The simulations have been generated using computer
simulation technology (CST) studio. Optical antenna is performed from a pair of nanoparticles brought in
close nearness, these pairs are separated by small gap to make a high electric field in its gap region. This
feature can be employed for biosensing or SERS to improve the detection limit and measure the presence
of single molecules

In this work, a system of a heat pipe is implemented to improve the performance of flat plate solar collector.
The model is represented by square shape portion of the evaporator section of wicked heat pipe with a
constant total length of 510 mm, and the evaporator section inclined by an angle of 30o
. In this models the
evaporator, adiabatic and condenser lengths are 140mm, 140mm, and 230mm respectively. The omitted
energies from sunlight simulator are 200, 400, 600, 800 and 1000 W/m2 which is close to the normal solar
energy in Iraq. The working fluid for all models is water with fill charge ratio of 240%. The efficiency of
the solar collector is investigated with three values of condenser inlet water temperatures, namely (12, 16
and 20o C). The numerical result showed an optimum volume flow rate of cooling water in condenser at
which the efficiency of collector is a maximum. This optimum agree well with the ASHRAE standard
volume of flow rate for conventional tasting for flat plate solar collector. When the radiation incident
increases the thermal resistance of wicked heat pipe is decreases, where the heat transfer from the evaporator
to condenser increases. The numerical results showed the performance of solar collector with square shape
evaporator greater than other types of evaporator as a ratio 15 %.

This paper studies the performance of steel tube truss girders filled with self-compacting concrete. Four
concrete-filled steel tubular (CFST) truss girders specimens were tested. The first novelty in this research
was using square tubes to manufacture truss girder. The main parameters were the bottom chord concrete
compressive strength and reinforcing steel bar employment in the bottom chord (second novelty). One bar
with a nominal diameter 16mm was used to reinforce the concrete in the bottom chord while keeping the
concrete in the top chord without reinforcement. This paper shows the load-displacement curves at the midspan, deflections along the span, peak loads, flexural strength, and failure shapes of the tested specimens.
The design equation was used to predict the flexural strength of CFST truss specimens. Results show that
the flexural strength was increased with the increase in the concrete strength from 29.23MPa to 48.41MPa
by about 4.5% and was increased by about 10.27% when using reinforcing the concrete in the bottom chord.

This study deals with the atomization of hollow cone spray water with low air cross flow. The visualization
of the hollow cone spray by shadowgraphy, from the nozzle exit. The diameter of the nozzle allows
observing different modes of breakup and structures (ligaments, helices, ...). The treatment of these images
makes it possible to determine the drop size distribution of the spray droplets in function of length scales of
the downstream flow. In the measurements of water hollow cone spray with injection pressures of 25kPa
and air velocity of 10 m/sec. The calculations at the exit of the injector, in two planes perpendicular, and
the average droplet sizes in the presence of air low cross flow conditions. The high- speed imaging is used
to capture the final spray. These images are analyzed by using the image software. The structure and
characteristics of the whole and sectional body of the spray are investigated at different times. The results
show the droplet trajectory profile of the liquid droplets is in a good an agreement with analytical solution.

An assessment was made for the impact resulted by the addition of (mixing of Di-isopropyl Ether with Olive
Oil (DO)) and (mixing of Di-isopropyl Ether ,Olive Oil and Aniline (DOA)) on the octane number as well
as Reid vapor pressure (RVP) of gasoline with different chemical compositions. The locally produced
gasoline is blended with three different ratios (v/v) of the additives, i.e. 8, 10 and 15%. It was observed that
the octane rate of gasoline increased continuously and linearly with the addition of (mixing of Di-isopropyl
Ether and Olive Oil (DO)) and (mixing of Di-isopropyl Ether ,Olive Oil and Aniline (DOA)). The DOAgasoline blends produced higher gasoline octane number. The two additives noted a significant reduction in
RVP and CV of the original fractions when blended with gasoline. However, additives were add in (8, 10,
15%vol) to gasoline blend, increasing RON was (0.9-23.9)

Bypass cement dust was supplied from the Alkufa cement factory, which has been used in preparing glass
ceramic material. The percentage of bypass cement dust, which is included in the overall batch, is about 30
wt %. The bypass cement dust composition has been modified by adding other materials like marble, granite,
and silica, to prepare glass ceramic material by powder technology. The prepared samples with different
ratios ingredients were pressed under a load of 15 tons/cm2
for 90 sec, in a steel mold of 30 mm in diameter,
liquid phase sintering is carried out by using High-Temperature Furnace at 100 – 1250 º C and 208/240
VAC. Techniques including SEM (Scanning electron microscopy) and XRD (X-ray diffraction) tests were
then used to evaluate the produced material. The obtained glass ceramic material has high bulk and apparent
density, low apparent porosity, high compression strength and hardness , low electrical and thermal
conductivity. The XRD and SEM results showed that glass ceramic materials are formed. The phase
transformation has happened and the titanite, wollastonite, diopside, periclase, and silica condense clusters
phase are formed, which are the important phases of glass ceramic. Tests show that the sample A5 contains
38% bypass cement dust, 30%granite, and 32% silica; and the sample C5 contains 28% bypass, granite 30%,
marble 10%, and silica 32%; and the sample B4 contains 59% bypass, 25% marble, and 16% silica. Showing
properties A5 and C5 which conform to that of glass ceramic properties better than B4. The research is
considered a pioneer work in the field of investment of dust of bypass cement for producing glass ceramic
materials. It represents an important step and could be the basis for future researches leading to the
achievement of glass ceramic production in Iraq.

Copper removal from simulated wastewater was investigated by using a rotating tubular packed bed of
woven screens electrode as a cathode in a new design of the electrochemical reactor. The effects of
electrolysis operating parameters like current (0.5–2.5 A), rotation speed (150–750 rpm), and initial copper
concentration (100–500ppm) were investigated. Optimization of process parameters was carried out by
adopting response surface methodology (RSM) combined with Box–Behnken Design (BBD), where copper
removal efficiency was selected as a response function. The results indicated that the current has the main
effect on the copper removal efficiency followed by rotation speed and concentration. The results of
regression analysis revealed that the experimental data could be fitted to a second-order polynomial model
with a value of determination coefficient (R2
) equal to 0.9894 and Fisher test at a value of 51.57. The
optimum conditions of the process parameters based on RSM method were an initial copper concentration
of 205 ppm, current of 2.5A, and rotation speed of 750 rpm utilizing cathode composed of screens with
mesh no. 30 where a final copper concentration less than 2 ppm was obtained after 30 min.