AL-Rafidain Engineering Journal (AREJ)

This study deals with evaluating and developing speed predictive models of vehicles on horizontal curves for
multilane rural highways. A total of 37 sites were identified, and data were collected through field surveys in sections of
Northern Iraq. Speed data were collected using a radar speed gun, while the curve length was measured using appropriate
surveying equipment. The models were developed using Minitab 21 software and the simple linear regression method. Two
predictive models were developed to estimate the speeds of passenger cars and heavy vehicles at the midpoint of the curve. The
developed models indicate a positive correlation between vehicle speed and curve length. The coefficient for passenger cars
(0.207) is nearly twice that of heavy vehicles, suggesting a more significant impact of curve length on the operating speeds of
passenger cars compared to heavy vehicles. The authors suggested studying the effect of other factors on operating speed. In
addition, they proposed developing models for each type of vehicle for different types of roadways.

Contingency studies are conducted to assess the importance and reliability of power control systems by
evaluating unspecified equipment outages under various conditions. This study conducts a comprehensive contingency
analysis of a hybrid power system including distributed generators (D.G.s), wind farms, solar photovoltaic arrays, and
grid connections to evaluate its resilience under N-1 power outage scenarios. Steady-state, dynamic, and voltage stability
analyses are performed using Newton-Raphson and fast power flow simulations. The study presents key performance
indicators for steady-state and dynamic responses, addressing voltage stability, thermal overload, and power flow
redistribution. Mitigation strategies are proposed, including partial power compensation, ready-to-use generation
scheduling, load shedding, and system resilience. The study also highlights the importance of contingency analysis based
on reliable NERC/WECC standards and indicates how changing conditions impact grid resilience. The ETAP analysis
supports an N-1 evaluation and the strategies used to determine system performance parameters, providing optimized
operating thresholds for each component in the power system through the addition of user-defined components and failure
scenarios. A hybrid power system was analyzed based on the separation of busbars, cables, distribution generator,
transformers, wind generators, and the solar array. The study presents a new composite performance index (CPI) for use
with hybrid power systems, integrating four sub-indices: voltage integrity (V/Vsp), real and reactive power deviations (ΔP
and ΔQ), and branch overload (S/Ssp) to classify the severity of the contingency. The results show that the power outage
on bus 1 (connected to the main grid) is the most severe (CPI = 103.065). In contrast, the outage's impact on the
photovoltaic arrays is minimal (CPI < 1), highlighting the system's reliance on centralized generation. The study also
shows that proximity to high-power transmission elements enhances the impact of the contingency, while distributed
renewable energy sources enhance resilience. This work provides practical insights for grid operators managing hybrid
systems amid increasing renewable energy deployment and climate-induced disruptions. A reliable power grid isn’t just
about avoiding blackouts, it’s about designing systems that can adapt, recover, and keep electricity flowing even when
things go wrong. This paper provides both the tools and the mindset needed to build that future.

Accurate segmentation of cardiac structures (right ventricle (RV), left ventricle (LV), and myocardium (Myo))
from cardiac MRI images plays an important role in the diagnosis and treatment of cardiovascular disease. However,
despite all this, segmentation of these structures at the micro level remains a major challenge due to the complex anatomical
diversity and noise inherent in MRI data. This paper examines the performance of various cardiac MRI segmentation
techniques, with a primary focus on the overlapping U-Net structure, attention mechanisms, and fuzzy pooling strategies.
This study comprehensively evaluates these methods, both independently and in combination, to determine their
effectiveness in improving segmentation quality for the RV, LV, and myocardial regions. Additionally, the effect of
thresholding strategies on segmentation accuracy is examined. The experimental results on the Automated Cardiac
Diagnosis Challenge (ACDC) dataset show that the proposed model (combining nested U-Net, attention mechanisms, and
fuzzy pooling) achieved a dice score of 98.20%, an accuracy of 96.83%, and a recall of 96.83%, superior to other basic
methods. In comparison, the best-performing core model, ANU-Net, achieved a Dice score of 94.31%, accuracy of 95.19%,
and recall of 93.44%. These findings underscore the superior performance of the hybrid model in terms of segmentation
and boundary delineation accuracy. These results confirm the potential of hybrid deep learning models in developing
cardiac image analysis. Future work will focus on improving these configurations across diverse datasets and also
exploring real-time deployment strategies in clinical settings.

Image fusion and the U-Net architecture have been successfully applied to many real applications, in particular,
cardiac segmentation. This paper suggests a new version named Hybrid Early-Late Fusion U-Net(HELFU-Net) to segment
the cardiac structure into regions. The design has been built by extending the U-Net with five encoder branches and one
decoder branch. The encoder branches take advantage of the adjacency property within the cardiac slice-images stack to
boost the accuracy of the target image. The first branch of the encoder in the U-Net is to merge adjacent images using the
concept of early-stage fusion. The next three branches apply late-stage fusion to the features of adjacent slices that are
processed separately. The last branch is for the target slice of the image, while the decoder branch retrieves the data. This
design boosts spatial information collection using only 2D image slices. HELFU-Net is evaluated using a public dataset of
the ACDC challenge. The experimental results gave mean dice coefficients of 0.942, 0.856, and 0.893 for left ventricular
cavity, right ventricular cavity, and left ventricular myocardium, respectively, on the test dataset. Additionally, the
suggested HELFU-Net gives 94.9% comparable predicted accuracy on the test dataset over a test time of 1.065 sec.

This work aims to study the improvement of silty soil properties using different cement column methods. A silty
soil was selected from Nineveh Governorate, Iraq, and its engineering properties were determined. Then, the soil was
treated with different cement ratios, and samples of the cemented soil were cured for different periods at 25°C. Cement
columns used in this study were implemented in the soil in two ways: The first one is the dry method, and the second method
involved adding cement to the soil in a solution at a water/cement ratio equal to 0.4%. These columns were implemented
inside the soil in a laboratory model and left to cure for 28 days before testing. The results indicated that the dry
implemented cement columns yielded greater improvements in the bearing capacity of the silty soil than those constructed
using the wet method, with the bearing capacity increasing by 3 and 2 times for the dry and wet-implemented cement
columns, respectively. Also, stress-settlement behavior was improved with cement columns, and the improvement ratio was
higher with the dry method than with the wet method. Cement ratios and different curing periods contributed to a significant
reduction in the collapse potential and improvement in compressive strength, which is an outcome of the products of
pozzolanic reactions. Finally, these methods can represent an ideal solution for treating silty soils locally compared to
other techniques that may be costly and time-consuming, especially at great depths.

Although single-phase transformers are crucial parts of contemporary electrical power networks, reactive
power demands and harmonic distortions can severely impair their performance under non-linear. In order to improve
transformer performance by reducing harmonic distortions and enhancing power quality, this study suggests integrating
a pass-tune filter. The study shows how the suggested filter affects transformer efficiency and voltage control under a
range of load conditions, such as linear, non-linear, and fluctuating loads. A single-phase transformer (3 KVA, 220 volts,
and 50 Hz) is simulated in this work. Different topologies of filters have been used in this work. The results demonstrate
the pass-tune filter's potential as an affordable remedy for power quality problems, guaranteeing dependable transformer
operation in practical applications. Different loads (linear load and non-linear load) before and after adding the filters
were examined. THD due to higher distortion in the R-L load reaches 22% and 49% for the voltage and current,
respectively. Fast Fourier Transform (FFT) analysis after applying the filters to both voltage and current shows
acceptable total harmonic distortion values within standards (less than 5%). Simulation findings show that the pass-tune
filter effectively reduces losses, improves overall operating stability, and lowers total harmonic distortion (THD).

Seepage in earth dams is one of the most challenging issues in geotechnical and hydraulic engineering, as it
directly impacts dam safety and reservoir performance. Seepage may lead to internal erosion, piping, and structural failure
if not effectively handled. This paper aims to study the effect of sheet pile installation at the dam body and foundation on
seepage reduction at the proposed earth dam located in the Al-Khoser seasonal river basin, Mosul city, northern Iraq. The
study also compares the effectiveness of sheet piles with other seepage control methods. Seepage analysis was performed
using the SEEP/W submodel within the Geo-Studio package. Different Scenarios were analyzed. The first (12) Scenarios
involved a homogeneous dam body without a core, exploring different configurations of blankets and foundation
treatments. The final Scenario No. 13 incorporated a central impervious core. The results demonstrated that sheet piles,
due to the low hydraulic conductivity of the foundation, had minimal effect on reducing seepage rates. However, an
improvement was observed in Scenario No. 12, where an extended upstream blanket was used, which reduced seepage to
(1.1 × 10⁻⁷ m³/s) through the dam and (1.44 × 10⁻¹⁰ m³/s) through the foundation. In Scenario No. 13, the usage of a core
reduces the seepage considerably, where the seepage rate was reduced to (8.45 × 10⁻8 m³/s) through the dam body and to
(1.35 × 10⁻¹⁰ m³/s) through the foundation, which mean that seepage decreased by 35% in the dam body and 18% in the
foundation compared to the first Scenario.