Journal of Engineering

Production of biodegradable polymer matrix biocomposites that are cost effective,
sustainable, and environmentally friendly with desirable properties using particles as
discontinuous phase (filler) is a welcome development. In this study, bamboo particle
reinforced epoxy resin matrix biocomposites were developed by stir casting method. Varied
weight percentages (5 to 30 wt. %) of 100 µm bamboo particles were added separately and
blended with an epoxy resin – hardener matrix. The blends were fed into a fabricated
wooden mould and allowed to cure at room temperature. After 24 hrs, the specimens were
removed from the mould and subjected to microstructural examination using a Scanning
Electron Microscope (SEM). Furthermore, the physical and mechanical properties
characterisation of the specimens were also carried out. The results obtained from the
experiments showed the presence of pores in the microstructure of the specimens and the
distribution of reinforcing particles in the epoxy matrix. The reinforced composites (S2 to
S6) demonstrated an appreciable increase in density when compared with the unreinforced
control specimen (C1). Specimens (S2 to S6) demonstrated lower water absorption than C1.
The composites demonstrated increased ultimate tensile strength with filler addition up to
25 wt. %. Similarly, the reinforced specimens demonstrated improved hardness as the
weight percent (wt. %) of bamboo particles increased up to 25 wt. %. However, the
composites demonstrated a reduction in impact energy as filler content increased when
compared with the control specimen. Specimen S5 formulation, which contained 25 wt. %
of reinforcing particles demonstrated the best properties in terms of density, water
absorption, hardness, and ultimate tensile strength. These findings highlight the
effectiveness of bamboo particles in enhancing the physical and mechanical properties of the
developed ecofriendly biocomposites.

Rutting is a significant problem in flexible asphalt pavements, causing permanent
deformation. Increased traffic, axle load, tire pressure, and hot weather have recently
accelerated rutting in flexible pavements. Several researchers have suggested using
nanomaterials to improve asphalt pavement and prolong its lifespan. The nano clay chosen
for this study is a natural, hydrophilic montmorillonite in its raw form. Consequently,
incorporating Nano-montmorillonite (MMT) into asphalt mixtures to improve performance
under dynamic loads has gained significant attention. This can help reduce rutting damage
and ensure the safety and durability of road surfaces. This study examines the impact of
incorporating MMT into hot mix asphalt on the Marshall properties and resistance to rutting.
It involved determining the optimal asphalt content using the Marshall design method, as
well as the rutting depth for asphalt mixes using wheel tracking tests, for mixtures
comprising different MMT percentages (2%, 4%, and 6%) as a percentage of the asphalt
binder. The optimal asphalt content was 4.93% for the control mix. The inclusion of 6% MMT
increased the Marshall stability the most by 16.79%. Marshall flow decreased when MMT
was added. The control mix had a Marshall flow of 3.30 mm, but when using 4% MMT, the
flow decreased to 2.81 mm, the most significant reduction. The ideal proportion of MMT was
6%, resulting in a 39.79% reduction in rut depth compared to the control mixture.

Industrial wastewater is discharged in large quantities into water bodies, and different
treatment processes are employed to reduce pollutant levels. This study quantifies copper,
iron, cadmium, cobalt, lead, and nickel levels in industrial wastewater samples at Al-Dora
refinery. Results showed variations before and after treatment, with physical and chemical
tests conducted in summer and winter. The measured values were (pH, T, Turbidity, EC, TSS,
TDS ), respectively (8.23, 34.8 °C, 60.88 NTU, 2883 ms/cm, 575 mg/L, 1441 mg/L) in summer,
while in the winter it was (7.516, 28.6 °C, 100.6 NTU, 1147 ms/cm, 780 mg/L, 569.8 mg/L),
respectively. Heavy metals were measured and showed a slight decrease during the
treatment units, nevertheless, they continue to be among the environmental determinants
of the Iraqi river maintenance system (1967). The measured elements were (Cu, Fe, Cd, Co,
Pb, and Ni), and their concentrations in the treated water and discharged to the river were
(0.064, 0.020, 0.109, 0.031, 0.029, 0.092) mg/L, respectively, in the winter. While in
summer, their concentrations were (0.017, 0.018, 0.0105, 0.017, 0.138, 0.078) mg/L,
respectively. The values of pollutant concentrations were a key environmental factor in the
maintenance of Iraqi rivers, as the treatment plant effectively reduced or removed these
pollutants from the water before discharging it into the river, without impacting water
quality.

One of the challenges that arises frequently when carrying out residential investment
projects is building delays. This study aims to fill this gap and add more to the body of
knowledge about residential investment projects in Iraq. The research methodology was
divided into two sections: one on previous studies, as mentioned in this research, and the
other on techniques and tools for reducing residential project delays. The researcher
concluded that there are several issues with residential projects, like inadequate project
comprehension, outdated methods, untrained contractors, etc. This issue is not readily
resolved and can have a detrimental effect on the project's outcome, including cost overruns,
subpar work, a lack of safety, and schedule delays. In addition to other detrimental social
effects, project delays may occur at some point during the construction process, and in
certain cases, even when the project is completed. A construction project must be completed
on schedule and within the projected budget. Approximately eighty-four pertinent articles
over the past twenty-five years have been examined. This issue has a direct influence on
people's lives and social welfare. Implementing residential project policies for new clients
has sparked building projects and increased demand for residential buildings. However, a
lot of residential projects were abandoned or never finished, which seriously concerned the
government.

In the field of gear design, to apply any form of analysis (such as FEA, dynamic, and stress
analyses), a delicate and accurate representation of the gear geometry is essential. It is the
foundation for any design modification attempts, and any approximation of the tooth profile
must be avoided. In the literature, many approximations were held to the involute tooth
geometry, particularly in the filet region, where it was simply represented by a straight line
or circular arc instead of a true trochoidal arc from a generation process. This approach
might lead to inaccurate bending stress results, as it fails to detect the impact of the undercut
or the profile correction process. Other common approximations have been widely observed
in the literature, such as utilizing an asymmetric cutter to simultaneously generate the two
sides of the asymmetric gear. Moreover, the graphical rack-cutter generation technique was
widely used to generate involute gears. This technique, although shown to be accurate in
generating a 2D standard tooth, is time-consuming as it necessitates the use of source code,
a programming language, a graphic processor for displaying computer graphs, a post
graphic processor for eliminating unrelated lines, and a post-process for exporting the tooth
geometry to CAD software. This research presents an alternative direct computerized
generation method that is shown to be accurate, generate both 2D and 3D gears, and be
significantly more time-efficient. Moreover, a novel technique to generate a fully asymmetric
nonstandard tooth (pressure angle, trochoidal fillet, and shifting factor) is proposed using
two half-cutters.

Globally, the focus is on maximizing the energy yield and efficiency of PV systems as an
essential renewable energy source. Different methods have been proposed to achieve this
goal. Where the sun’s location in the sky is changed during the day, a tracking mechanism
has been proposed as a promising technology to harness the maximum amount of solar
radiation by PV system as compared to the fixed panels. In this study, the design and
implementation of a polar single-axis tracking system is presented to improve the energy
efficiency of PV system through angular variation during the day using the proposed tracking
system. This is achieved by interconnecting some devices that include GPS sensors and
satellite dish actuators as the main components that are managed and controlled using
astronomical equations. The designed system is tracked in a discrete manner that can be
adjusted automatically during the day related to each degree change of azimuth angle of the
sun from sunrise to sunset. The system has been field tested in Sulaymaniyah, Iraq, to
evaluate its performance in different weather conditions and compare it with a fixed PV
system. The test results for the clear sky indicated that the increased amount of energy
production for the tracking system is 36.6% as compared with the stationary panel.
Whereas, for a mostly cloudy day the measured amount of increase was 18.5%. This
improvement of the harnessed energy for PV systems is important to make the system more
efficient and sustainable.

Hydrological studies have become more important in recent years to estimate flow
discharges in the valleys. The study area of Al-Ghadaf Valley was chosen due to the absence
of surface runoff information for this valley. This research studied the watershed of Al
Ghadaf (GW) by using the SWAT model. It wasn’t possible to perform calibration and
verification for the model due to the absence of actual discharges in the Al-Ghadaf valley. The
area of the catchment was 8567.25 ???????? 2 and the weather data used in this model was for
three actual stations, Rutba, Ramadi, and Al-Nukhaib, for 13 years from 2009 to 2022. I
wasn’t able to choose a period larger than 13 years because some of them are missing.
Despite this, one of the features of the period that was chosen is that the years 2019 and
2013 fall within the chosen period and are considered flood years by the Iraqi Ministry of
Water Resources. The results show that the maximum daily flow discharge for Al-Ghadaf
that outflows into Al-Razzaza Lake was 312.1 m 3/s, the maximum surface runoff depth (mm)
for all watersheds was 6.62 mm, and the average curve number for the basin was 88.4. These
results will help future researchers in this study area and decision-makers in the Ministry of
Water Resources to know the amount of water coming from this basin and feeding Al
Razzaza Lake, especially since there are no previous studies about this basin showing the
amount of water falling on the basin and coming to the lake.

Gypseous soil is classified as problematic soil, characterised by its characterized by
complicated and erratic behavior, and is mostly found in arid and semi-arid areas of the
globe. As for Iraq. Gypseous soils cover about 30-35% of the total area of Iraq, as this type of
soil is found in the Western Desert and extends to the southern parts of the country.
Gypseous soils are considered strong but susceptible to sudden collapse when wet. To
control the collapse of gypsum soils, Geotextiles are among the most popular kind of
geosynthetic material used for soil reinforcement. The goal of this study is to determine
whether woven geotextiles can improve the ultimate bearing capacity of foundations
constructed on gypsum soil. The foundation is built from a strong 10mm thick steel plate
measuring 100mm x 100mm. In this study, the depth of the geotextile layer that was placed
at depths of (0.1B, 0.2B, 0.4B, 0.8B, B) was determined from the width of the foundation used,
the number of layers of the reinforcement material (one layer, two layers, and three layers),
and the layer-to-layer vertical spacing. Geotextiles: The geotextiles' breadth was also
examined. The trials' findings demonstrated that adding geotextile reinforcement to soil can
help it have a higher bearing capacity. and reduce the settlement of the gypsum soil. It was
found that placing geotextiles at depths of (0.8B-B) is the best depth chosen, and the results
were also revealed. The test showed that using three layers of geotextile gave positive
results. Additionally, the test findings demonstrated that the reinforcement's composition
had a significant impact on the behavior of the foundation.

Urban forms and configurations are very influential in building up urban life; they affect
street configuration, visual permeability, and spatial accessibility. However, the importance
of this in impacting the performance and vibrancy of urban spaces has not been
comprehended so far. Thus, the following paper takes a closer look at the key areas within
downtown Baghdad, namely Alshorja and Bab AlSharqi, to analyze their urban
characteristics. A comprehensive methodology was developed for this research that
combined qualitative and quantitative methods, including field survey, GIS digitization, and
space syntax analysis, which enabled an in-depth investigation into the street pattern, visual
permeability, and spatial accessibility of the chosen case studies. The findings show sharp
differences between the organic, random street pattern of AlShorja—which tries to make
pedestrians move and socialize more easily—compared to Bab AlSharqi’s grid system, which
tries to promote an extensive flow of vehicles and businesses. AlShorja, therefore, has higher
local connectivity and street vitality in its condensed layout than Bab AlSharqi, which comes
with higher visual permeability and spatial accessibility and presents the image of a CBD.
The study concluded that the blending of historical context with contemporary needs should
be considered to develop livable urban environments. Pedestrian-friendly features to
integrate in AlShorja combined with the principles of accessibility and navigability in Bab
AlSharqi will, in turn, enhance urban vitality and connectivity. More diversified methods in
future research will enrich urban planning and design for cities like Baghdad, including
wider metropolitan areas.

The Weather Generation Model “LARSWG” and hydrological Model “SWAT” used in this
study to estimate the quantity of future surface runoff in the Sahiliya Valley located within
the Iraqi western desert. The weather data for the last ten years used as input in the LARSWG
model to generate future weather data under the effect of climate change. In this model, the
statistical test analysis done automatically, with two statistical test values, the (KS-value)
test and the (p-value) test. The results of these tests are equal or close to zero (0.0) for KS
values, and equal or somewhat close to one (1.o) for p-values, which means the LARS-WG
model is perfect for generating rainfall and temperature, and is more suitable in simulating
the seasonal distributions. Data results from the LARSWG model used as input weather data
in the SWAT model. For the SWAT model, several data are required for its software operation
such as a digital elevation model, Land use-land cover, soil map, and weather data. SWAT
modeling was done for watershed delineation for this valley yielding (14) sub-basins and
(59) hydrological response units. To test the suitability of applying this model, two Statistical
tests (Nash-Sutcliffe - NS) and Coefficient of determination - R2 test were applied for the two
sets of data on Surface Runoff in both calibration and validation periods. The results of these
tests are (0.72) (0.78) for calibration, and (0.64) (0.67) for validation respectively. The
values of the (NS) test for both simulated and calculated data in the calibration and
validation periods are somewhat similar. Also, the same goodness of results in the (R2). The
data results from SWAT modelling shows that maximum runoff occurs in October and
November in winter season, and March in spring season in each year, and the runoff occurs
at a rate of one to four (1-4) times annually, and in some years twice only. This means that
the amount of surface runoff water added to the Euphrates River is limited from this valley.

Whenever a mathematical model is suggested to classing COVID-19. The population must
be divided into several groups and our model has five groups namely S(t), E(t), I(t), V(t) and
R(t) which represent susceptible, exposed, inflected, vaccinated and recovered individuals
respectively. This model is a continuous dynamical system where the derivative is in
fractional form. An analysis solution evaluates the positivity of the functions S(t), E(t), I(t),
V(t) and R(t) as solutions of the system. The uniformity of the solutions of the system under
consideration is also proved. And finding the equilibrium points. To get acceptable results
one needs the solutions. Some of the solutions are points called equilibrium points and the
other are functions. and studying their stability fractional differential system orders are
checked locally and globally. The basic reproduction number is used to prove the stability of
all equilibrium points as well as the method of the nature of the eigenvalues of the Jacobian
at each equilibrium point. And then studied the local bifurcation to the asymptotically stable
and stable equilibrium points. And evaluated approximately. These solutions must satisfy
the nature of the problem under consideration for example under certain conditions some
of the equilibrium points are stable. Also, the approximate solution must give results close
to the real situation. All these demands are shown in this paper. Approximate and Numerical
simulation is given through a tables and graphs which shows the efficiency of the method,
using the MATLAP to all the figures.

A theoretical study is done to treat Baghdad biomedical wastes (5.21 tons/day) using many
treatment methods according to construction and maintenance costs, energy and water
consumption and decreasing waste volume and mass. Previous published experimental data
results and experimental operation conditions are considered in the current research. The
thermal energy and generated wastes are computed from the complete combustion of
biomedical wastes (100 kg/h) from two hospitals in Baghdad. Survey data shows that the
Medical City and Al-Yarmouk Hospital generate about (700 kg /day) of biomedical waste. A
multi-chamber incinerator with a capacity of (100 kg/h) has been designed to burn
biomedical wastes using diesel fuel to reach (1100˚C) as a burning temperature. The
resulting thermal energy was computed to be (0.7178565 MW) which is emitted directly
with flue gases to the ambient without any off-gas system. The mass of flue gases is found to
be (1895.8175 kg/h) and the gases are (193.20872 kg/h for CO2 and 1.6352 kg/h for HCl)
through using excess air ratios at 150% for solid wastes burning and 20% for liquid fuel
burning. The required cement and water are determined for resulting ash to produce
concrete suitable for hot weather countries. The results show that incineration has the less
costs in construction and operational costs among other modern technologies with a
decreasing waste mass to 91.5%.