Journal of Engineering

Disposal of plastic waste causes serious environmental problems, including landfills and
water bodies degradation, greenhouse gas emission, soil contamination and so on. This
study investigates the use of recycled plastic aggregate (RPA), as a partial replacement for
conventional coarse aggregates by weight in lightweight concrete production. Concrete
mixtures with different concentrations of RPA at (0, 15, 30, and 45%) were prepared and
cured for 7, 14, 28, and 56 days. Including RPA into concrete reduced both density and
compressive strength as the replacement level increased. Density decreased from 2,347
kg/m³ at 0% RPA to 1,895 kg/m³ at 45% replacement. Similarly, 28 days compressive
strength decreased from 30.43 N/mm² (control) to 19.50 N/mm² at 45% replacement,
reflecting the lower specific gravity and weaker bonding of RPA compared to traditional
coarse aggregate. Additionally, the test results showed that RPA concrete has a low water
absorption rate at 15% replacement, with 2.50% for water absorption and a 0.0235 mm/s1/2
sorptivity value compared to control samples with 2.66% for water absorption and 0.024
mm/s1/2 sorptivity value. However, concrete samples with up to 30% RPA replacement met
the minimum requirements for structural lightweight concrete. This study also used
machine learning models, including artificial neural networks (ANN), k-nearest neighbor (k
NN), and random forest (RF), to predict the durability properties of RPA concrete. Among
these models, the k-NN model showed the best prediction accuracy with an R² value of 1.00,
a mean absolute error (MAE) and a mean square error (MSE) of 0.001 for both the train and
test data. These findings show that the use of treated RPA in concrete not only offers a
sustainable alternative to natural aggregates but also improves the durability of the
resulting structures.

Atterberg limits play a crucial role in soil investigations due to their ability to provide
fundamental insights into the mechanical behavior of soils. The primary objective of this
study was to derive empirical equations for determining the liquid limit (LL) and plastic limit
(PL) of soils using only soil particle size distribution data. Microsoft Excel was used for
statistical analysis, applying 10 different methodologies. The methodology integrated the
clay fraction (CF) (<0.002 mm) as the main independent factor in all models. The only
independent variable in model M1 is CF, while model M2 includes sand and silt, in addition
to clay fractions, as independent factors. In the analytical process, the number of
independent variables progressively increased from model M1 to model M10, systematically
enhancing the predictive capacity of the models. Using this methodology, two robust
equations were developed in model M6, which are capable of determining LL and PL, with
R-squared values reaching the value 1.0 and an RMSE of approximately zero; however, it is
important to note that while an RMSE of zero does indicate an R-squared of 1.0, an R-squared
of 1.0 does not necessarily imply a zero RMSE. The results of this study show that full grain
size analysis data alone may effectively predict LL and PL, negating the need for additional
physical or chemical characteristics of the soil.

The issue of noise transmission between residential units in high-rise buildings poses a
significant challenge to privacy and auditory comfort, especially amid increasing urban
expansion and population density. This study aims to address this problem by evaluating
sound insulation strategies in high-rise residential units and assessing their alignment with
international standards within local contexts. Six global residential projects were analyzed
based on their adoption of advanced acoustic insulation solutions. The methodology
involved examining key design elements such as the spatial distribution between quiet and
noisy areas, and the use of insulation materials and techniques for walls, floors, ceilings,
doors, and windows. Standardized indicators were used to assess the efficiency of these
strategies, supported by statistical analysis. The results revealed varying levels of success in
reducing noise transmission, with notable effectiveness in windows, ceilings, and floors
where modern technologies and advanced materials were applied. The findings also
highlight the importance of integrating sound insulation strategies during the early design
stages to enhance auditory comfort in residential environments. The study recommends
updating local acoustic standards and adopting more efficient design and technological
solutions to achieve sustainable and comfortable residential settings.

A photovoltaic modules convert only a fraction of incident solar energy into electricity, with
the remainder dissipated as heat through various loss mechanisms. This study makes an
attempt to quantify the recoverable thermal energy from multicrystalline silicon
photovoltaic modules under varying irradiance conditions for arid climates. Experimental
measurements were conducted over six months in Baghdad, Iraq. Data were filtered to
maintain 25°C module temperature across four irradiance levels (250, 500, 750, 1000
W/m²). Results demonstrate thermal losses increasing from 10.33% to 19.02% with rising
irradiance, while recoverable thermal energy fraction (ξu) ranges from 29.72% to 35.06%.
Module efficiency decreased from 18.1% at 500 W/m² to 16.7% at 1000 W/m², reflecting
thermal loss dominance over optical gains. Spectral analysis revealed uniform distribution
of recoverable thermal energy across the solar spectrum rather than infrared concentration.
The quantified thermal losses provide fundamental data for hybrid photovoltaic-thermal
(PV/T) system development optimized for high-irradiance arid conditions, supporting
renewable energy advancement where abundant solar resources enable combined electrical
and thermal harvesting.

This study numerically investigates the effect of different welding steel plate shapes on the
behavior of expanded open web asymmetrical steel composite beams. Increased web depth
of asymmetrical steel beams in composite concrete results in increased stiffness and
strength. Expanding the web's depth enhances the composite concrete steel beam's strength
and performance in specific design scenarios, such as expanded, cellular, or castellated steel
composite concrete beams. A horizontal cut in the web in each asymmetrical section can
create an expanded web of asymmetrical steel profiles. Two asymmetrical tees can then be
assembled, and a plate known as a spacer plate with a constant area and different shapes
can be added between the two halves of the asymmetrical tee sections. The Finite Element
(FE) numerical model developed by ABAQUS software was employed to develop and
evaluate new numerical models by considering a variety of increment plate configurations,
which resulted in the production of a greater number of models at a lower cost and more
efficiently. The results indicate that curved plates increased the ultimate load capacity, while
other shapes led to decreased stiffness. Therefore, the ultimate load capacity of the curved
plate increased by approximately 2.3% compared to the reference model due to a reduced
stress distribution.

In recent years, there has been exponential growth in the Internet of Things (IoT) in various
sectors, especially healthcare. The traditional healthcare sector has faced several challenges,
such as poor health services, crowding and queuing at medical centers, and manual searches
for or missing patient records; a smart health system is needed to overcome these
challenges. This study presents the design and implementation of end-to-end IoT
architecture, which is built by the integration of various open-source technologies. The pulse
care system is implemented using Node.js and React.js, which offer features such as
electronic health records (EHR), smart appointments, prescription documentation, and
health monitoring. Additionally, various users (admin, patient, doctor, and pharmacist)
communicate using a user-friendly graphical interface. In terms of a wearable device, it
allows visualization of all the data generated by the sensors in real time (heart rate, body
temperature, and blood oxygen). The ESP32 is used as a microcontroller that communicates
via its built-in Wi-Fi with the MQTT Mosquitto broker. Standard IoT protocols, Message
Queuing Telemetry Transport (MQTT) and Hypertext Transfer Protocol (HTTP), are used.
The broker's performance is evaluated in terms of average latency at various QoS levels and
with the increase in the number of concurrent users. The results of the experiment
demonstrate how important it is to choose the appropriate QoS level based on the
requirements of the application. Furthermore, the proposed system's data rate is roughly
3.07 kb/s, which is considered low and suitable for sending small data via any wireless
method

Bearing capacity of soil is one of the important matters that occupies the minds of
geotechnical engineers, especially in weak soils. In the field of geotechnical engineering, soil
improvement is one of the most commonly used techniques. However, difficulties in
implementation and increased costs have also caused scientists to look for more efficient
and effective techniques. Many researchers as one of the innovative and promising
alternatives have identified using skirts beneath shallow foundations in recent years. Their
research has demonstrated the effectiveness of this method in treating the condition of the
soil beneath the foundation, including enhancing bearing capacity vertically and laterally by
470% and 6.6 times, respectively, and reducing settlements by 186% and reducing rotation,
slipping, and the shallow foundation's uplift capacity by 397.7% on diverse soil types. For
offshore constructions such as jack-up unit structures, wind turbine foundations, oil and gas
plants, tension leg platforms, bridge foundations, and transmission towers, it was discovered
that skirted foundations might be a formidable rival to conventional foundation types. The
results obtained from this review indicate that there are many methods for improving
problematic soils to increase their bearing capacity, uplift capacity, and reduce settlement,
but all of these methods are largely related to the economic aspect and the feasibility of their
implementation on-site. This study demonstrated that the use of skirting is very cost
effective, as it is a successful alternative to deep foundations in problematic soils and
offshore conditions. In addition, the effectiveness of a skirt depends on factors such as length,
depth, relative density, and its suitability for various soil types (e.g., sandy, clayey,
liquefiable, and gypseous). Optimal skirt depth-to-width ratios improve the stability of
foundations exposed to inclined and lateral loads

This study examines the concept of urban competition, focusing on the role of heritage
urban places in enhancing urban competitiveness. Urban competition refers to a city's ability
to possess economic, social, cultural, and security-related competitive advantages within its
geographical region compared to other competing cities. Public places and urban
landscapes—particularly heritage ones—attract tourists and institutions, thereby
enhancing the city's image and interactively influencing the quality of urban life. A relatively
rich cultural heritage and urban atmosphere in modern cities contribute to improving the
quality of the place or attracting various stakeholders (such as institutions and
professionals). Many cities around the world boast a rich cultural diversity that contributes
to their overall attractiveness, which in turn reflects on their regional status and global
standing, thereby influencing urban competition. Definitions of urban space, heritage, urban
competition, and the factors that activate it were reviewed, along with a discussion of
previous studies to identify the research problem, which is the "knowledge gap in studying
the role of heritage urban places in activating urban competition." The research objective
was identified as "activating urban competition through heritage urban places." To
determine the relationship between urban places with cultural heritage value and their
impact on urban competition, a theoretical framework was developed that includes the
dependent variable (urban competition) and its indicators in urban places. This framework
was then applied to two case studies in the city of Baghdad. Results were presented and
analyzed, leading to conclusions that emphasized the importance of cultural heritage, quality
of place, and quality of life in urban places in activating urban competition.

Governments allocate large sums of money annually to establish educational projects such
as schools, given the importance of the education sector in the development of society.
However, most of these projects suffer from poor performance. This research aims to
identify the most important factors that affect educational projects in order to improve their
performance and make them a suitable environment for education. Through a review of
previous literature, a questionnaire was prepared to obtain the required data, which
included five main categories covering a range of factors that affect performance. It was
distributed to a number of specialized engineers, with different academic degrees and job
titles, working in the educational buildings sector. After obtaining the results from 49
respondents and processing them using SPSS-BIM version 23, and calculating the relative
importance index, it was found that the factors falling under the categories of “project
manager” and “planning” were among the most influential factors in project performance.
The most influential factors in each category were as follows: Project manager: Inefficiency,
poor management, slow decision-making; senior management: Funding versus work
completed, management support, hostile environment; planning: Weak and unstable, non
compliance with contract terms, changes in design and quantities; site: availability of skilled
labour, construction methods, coordination between parties, machine setup, construction
errors, material-related factors, and human resource experience and training; Monitoring
and evaluation: issues related to monitoring and evaluation budgets and planning for
monitoring and evaluation. Based on the results, a framework was developed to improve the
performance of educational projects.

One zinc-27 % aluminum alloy (ZA-27) with excellent corrosion resistance and high
hardness is ZA-27, making it suitable for industrial applications such as vehicle parts. The
alloy works better in tough mechanical conditions because it has carbide particles, like SiC
or TiC, added to it, which make it harder, more resistant to wear, and improve its internal
structure. Using Minitab statistical software, the design of experiments (DOE) was utilized
to conduct studies with a statistical two-level factorial experimental design. The effect of
three parameters, SiC particles percentage (X1), stirring speed (X2), and stirring time (X3),
was studied on the tensile characteristics of the SiC-enhanced ZA-27. The ingot was smelted
using the stir-casting process to make a composite material .Then, varied percentages of SiC
particles (0 and 5 wt%), speeds (300 and 900 rpm), and stirring times (30 and 60 min.) were
utilized to stir the molten metal. The regression results showed that there was a satisfactory
fit of the model variability for both SiC particles (X1) and stirring speed (X2). The p-value for
each parameter was less than 0.005, which is statistically significant. It was determined that
the factors X1 = 5 wt%. X2 = 900 rpm, and X3 = 60 minutes could provide the greatest tensile
strength of 465 MPa. The tensile strength (465.5 MPa) obtained in practice using the values
of X1, X2, and X3 calculated by the programs is almost identical to that obtained practically.

This literature review investigates the seismic behavior of low-rise steel structural frames
with fixed, pinned, and base-isolated column bases under single and successive earthquake
excitations. Experimental shaking table tests and Abaqus finite element models are utilized
to evaluate the impact of base flexibility on structural performance measures, including
inter-story drift, base shear, and acceleration response. Base-isolated systems, including
elastomeric, lead-rubber, and friction pendulum bearings, demonstrate superior energy
dissipation capacity and reduced seismic demand compared to traditional fixed and pinned
bases. While pinned bases offer rotational flexibility that reduces moment concentration,
they are susceptible to excessive lateral displacement in multi-story configurations. Fixed
bases provide stiffness but transmit higher forces directly to the structural frame. Current
research underestimates the seismic loading capability of base isolation and bracing
systems, despite significant advances in isolation technology. This review identifies a critical
research gap in evaluating hybrid seismic protection strategies, especially for structures
subjected to multi-event ground motions. Future directions are proposed to address these
challenges through integrated experimental and numerical investigations, aiming to
enhance the resilience of modern buildings in earthquake-prone regions.

Enhancing fatigue resistance in asphalt binders and mixtures is crucial for prolonging
pavement lifespan and improving road performance. Recent advancements in
nanotechnology have introduced various nanomaterials such as alumina (NA), carbon
nanotubes (CNTs), and silica (NS) as potential asphalt modifiers. These materials possess
unique properties that address challenges related to asphalt fatigue. However, their
effectiveness depends on proper dispersion and mixing techniques. This review examines
the mixing methods used for each nanomaterial to ensure uniform distribution within the
asphalt matrix and maximize performance benefits. Recent research findings are
synthesized to elucidate how these nanomaterials and their mixing processes enhance
mechanical properties, durability, and overall pavement performance. Evidence suggests
that incorporating well-dispersed nanomaterials significantly improves fatigue resistance,
leading to reduced cracking and extended pavement life. The review concludes that
integrating nanotechnology with effective mixing strategies presents a potentially effective
approach for advancing asphalt technology, optimizing performance across diverse
environmental conditions, and paving the way for more resilient infrastructure