Journal of Engineering

Exposure to cryogenic liquids can significantly impact the petrophysical properties of rock,
affecting its density, porosity, permeability, and elastic properties. These effects can have
important implications for various applications, including oil and gas production and carbon
sequestration. Cryogenic liquid fracturing is a promising alternative to traditional hydraulic
fracturing for exploiting unconventional oil and gas resources and geothermal energy. This
technology offers several advantages over traditional hydraulic fracturing, including
reduced water consumption, reduced formation damage, and a reduced risk of flow-back
fluid contamination. In this study, an updated review of recent studies demonstrates how
the thermal shock caused by the cryogenic liquid during the fracturing process substantially
affects the rock's physical properties. Additionally, changes in permeability, porosity, and
pore structure brought about by cryogenic treatments are highlighted. This work aims to
draw attention to the studies that deal with the effect of thermal shock on rock petrophysical
properties and establish the ideal conditions for employing cryogenic liquids in these
contexts. Simulation studies, laboratory trials, and field application cases have been
undertaken to assess the efficacy of cryogenic liquid fracturing technology. These
investigations have provided important insights into the physical and mechanical impacts of
thermal shock on rock and the performance of cryogenic liquid fracturing in real-world
situations.

Blockchain has garnered the most attention as the most important new technology that
supports recent digital transactions via e-government. The most critical challenge for public
e-government systems is reducing bureaucracy and increasing the efficiency and
performance of administrative processes in these systems since blockchain technology can
play a role in a decentralized environment and execute a high level of security transactions
and transparency. So, the main objectives of this work are to survey different proposed
models for e-government system architecture based on blockchain technology
implementation and how these models are validated. This work studies and analyzes some
research trends focused on blockchain and the future of e-governance for connecting citizens
and smart cities, such as Using Blockchain in the Notarial Office (NO), using blockchain
technology in the management of police complaints, exploring blockchain-enabled end-to
end security e-voting, using blockchain and smart contract technology for trusted and safe
property registration and record management, and using a blockchain-enabled Vehicle
Certification (BVC) framework. Finally, this work has proven that the issue of transforming
governments from the traditional system to electronic governments based on blockchain
technology has become an inevitable matter of time.

Cowpea is a very important legume in Nigeria that is being utilized to Substitute high-cost
animal protein for low-income people. The knowledge of some physical properties of various
moisture contents is of utmost importance in the design of its handling and processing
equipment and machinery, which is the aim of this work, which studied the physical
properties of IT99K-573-1-1 (SAMPEA14) variety of Cowpea within 8.77 to 21.58 % db
moisture content. The properties studied include Major, Intermediate, and Minor diameters,
Sphericity, Surface area, Specific gravity, Volume, Bulk density, 50-tap density, 100-tap
density, 1250-tap density, seed mass, Angle of repose, Geometric mean diameter, and
Arithmetic mean diameter. The obtained results indicate that the Size, Sphericity, Geometric,
Arithmetic diameter, Surface area, and seed mass increase linearly with an increase in
moisture content by 13.8%, 27.4%, and 16.1% for the size, respectively. While sphericity
rises by 7.5% and geometric mean diameter, arithmetic mean diameter, surface area, and
grain mass increase by 22.2%, 20.7%, 24.9%, and 16.11%, respectively. Specific gravity,
density, and repose angle were inversely linearly related to moisture content. Regression
equations for each of the properties related to the grains' moisture content were developed.

This paper analyzes a piled-raft foundation on non-homogeneous soils with variable layer
depth percentages. The present work aims to perform a three-dimensional finite element
analysis of a piled-raft foundation subjected to vertical load using the PLAXIS 3D software.
Parametric analysis was carried out to determine the effect of soil type and initial layer
thickness. The parametric study showed that increasing the relative density from 30 % to 80
% of the upper sand layer and the thickness of the first layer has led to an increase in the
ultimate load and a decrease in the settlement of piled raft foundations for the cases of sand
over weak soil. In clay over weak soil, the ultimate load of the piled raft foundation was
increased, and the settlement decreased by increasing the clay cohesion of the upper layer
from 20 kPa to 70 kPa. It was observed that the load shared by the raft was very effective
when using dense sand in the upper layer. In the case of dense sand over stiff clay, the
percent of load carried by the raft is (30-40) %. Although, for the case of stiff clay over soft
clay, the load percentage was almost constant (16-20) %. While for other issues, the sharing
load of raft foundation was close and had the same behavior, the load carried by raft is
between (8-12) %.

This paper aims to improve the voltage profile using the Static Synchronous Compensator
(STATCOM) in the power system in the Kurdistan Region for all weak buses. Power System
Simulation studied it for Engineers (PSS\E) software version 33.0 to apply the Newton
Raphson (NR) method. All bus voltages were recorded and compared with the Kurdistan
region grid index (0.95≤V ≤1.05), simulating the power system and finding the optimal size
and suitable location of Static Synchronous Compensator (STATCOM)for bus voltage
improvement at the weakest buses. It shows that Soran and New Koya substations are the
best placement for adding STATCOM with the sizes 20 MVAR and 40 MVAR. After adding
STATCOM with the sizes [20MVAR and 40MVAR] at Soran to the test, it is seen that the total
average change in voltage profile for the system improved results in about 17.34 % in
average per unit change for the 28 weakest buses, which provides a good improvement in
stability. Also, the system’s total active power loss reduced from 123.8 MW without
STATCOM to 102.8 MW with STATCOM. The results are encouraging for applying the
approach to the power system. This approach stands out due to all bus voltages are within
acceptable ranges.

This work investigates the impacts of eccentric-inclined load on ring footing performance
resting on treated and untreated weak sandy soil, and due to the reduction in the footing
carrying capacity due to the combinations of eccentrically-inclined load, the geogrid was
used as reinforcement material. Ring radius ratio and reinforcement depth ratio parameters
were investigated. Test outcomes showed that the carrying capacity of the footing decreases
with the increment in the eccentric-inclined load and footing radius ratio. Furthermore,
footing tilt and horizontal displacement increase with increasing the eccentricity and
inclination angle, respectively. At the same time, the increment in the horizontal
displacement due to the inclined load reduces with increasing the eccentricity ratio.
The results also revealed that the optimum radius ratio under eccentrically-inclined load is
n=0.30, the optimum depth ratio is U/B=0.50, and at the optimum depth ratio and with
eccentricity ratio of 0.16 and for the inclination angles of 5, 10, 15 the improvement in the
carrying capacity was by (115.1%, 126.5%, and 131.5%) for the inclination angles of
respectively.

Unconfined Compressive Strength is considered the most important parameter of rock
strength properties affecting the rock failure criteria. Various research have developed rock
strength for specific lithology to estimate high-accuracy value without a core. Previous
analyses did not account for the formation's numerous lithologies and interbedded layers.
The main aim of the present study is to select the suitable correlation to predict the UCS for
hole depth of formation without separating the lithology. Furthermore, the second aim is to
detect an adequate input parameter among set wireline to determine the UCS by using data
of three wells along ten formations (Tanuma, Khasib, Mishrif, Rumaila, Ahmady, Maudud,
Nahr Umr, Shuaiba and Zubair). After calibration with core test, the results revealed that
Young’s Modulus correlations are the best to predict UCS with RMSE (53.23 psi).
Furthermore, the result showed that using the static Young Modulus as an input parameter
in predicting UCS gives a closer result to the laboratory test than using a sonic log. This study
found that many previous equations were developed for only one type of rock and tended to
generalize poorly to the broader database. This study also provided more accurate rock
strength estimation, leading to better prognosis in operational strategies and hydraulic
fracturing location planning in oil well development when geomechanical analysis needs to
be addressed where no core is available. Finally, the expected continuous rock mechanical
profile indicates the formation's strength and stability around the wellbore.

Roller Compacted Concrete is a type of concrete that is environmentally friendly and more
economical than traditional concrete. Roller Compacted Concrete is typically used for heavy
duty and specialist constructions, such as hydraulic structures and pavements, because of its
coarse surface. The main difference between RCC and conventional concrete mixtures is that
RCC has a more significant proportion of fine aggregates that allow compaction and tight
packing. In recent years, it has been estimated that several million tons of waste demolished
material (WDM) produced each year are directed to landfills worldwide without being
recycled for disposal. This review aimed to study the literature about creating a Roller
Compacted Concrete (RCC) mix with modified engineering properties with favorable
environmental impact, so it was focused on investigating using different proportions of
waste (Glass, Brick, and Marble), which are the most waste-demolished materials (WDM)
widely in the world, as a partial substitute of cement. Then, study the influence on the
durability and mechanical strength of (RCC) produced with and without these waste
powders.

In this work, a flat-plate solar air heater (FSAH) and a tubular solar air heater (TSAH) were
designed and tested numerically. The work investigates the effect of increasing the contact area
between the flowing air and the absorber surface of each heater and predicts the expected
results before the fabrication of the experimental rig. Three-dimensional two models were
designed and simulated by the ANSYS-FLUENT 16 Program. The solar irradiation and ambient
air temperature were measured experimentally on December 1st 2022, at the weather
conditions of Baghdad City- Iraq, at three air mass flow rates, 0.012 kg/s, 0.032 kg/s, and 0.052
kg/s. The numerical results showed the advantage in the thermal performance of the TSAH in
comparison to the FSAH, represented by better air temperature difference, better heat transfer
from the absorber to air, and better thermal efficiency. The TSAH has a higher thermal efficiency
than the FSAH by 7 %, 19 % °C, and 22 % at 0.012 kg/s, 0.032 kg/s, and 0.052 kg/s, respectively.
The improvement of the thermal characteristics of the TSAH can be referred to as the increment
in the heat transfer contact area between the absorber and the flowing air.

To achieve sustainability, use waste materials to make concrete to use alternative
components and reduce the production of Portland cement. Lime cement was used instead
of Portland cement, and 15% of the cement's weight was replaced with silica fume. Also used
were eco-friendly fibers (copper fiber) made from recycled electrical. This work examines
the impact of utilizing sustainable copper fiber with different aspect ratios (l/d) on some
mechanical properties of high-strength green concrete. A high-strength cement mixture with
a compressive strength of 65 MPa in line with ACI 211.4R was required to complete the
assignment. Copper fibers of 1% by volume of concrete were employed in mixes with four
different aspect ratios (20, 40, 60, and 120). At 7, 28, and 60 days after typical curing, the
samples' mechanical characteristics (compressive strength, flexural strength, and split
tensile strength) are assessed. A reported increase in compressive strength of (2, 1.6, and
1.4) in (7, 28, and 60 days) for concrete with a high aspect ratio 120, compared to concrete
with a low aspect ratio 20. The flexural strength of high-strength green concrete with fibers
of a higher aspect ratio 120 was (23, 11, and 12.6%) times higher for all ages compared to
low aspect ratio 20. The split tensile strength rose (1.7, 1.5, and 1.6%) for (7, 28, and 60
days), respectively, for concrete with a high aspect ratio 120, compared to concrete with a
low aspect ratio 20. It was found that using fibers with a large aspect ratio improved the
mechanical properties of concrete more than fibers with a small aspect ratio.

Many researchers have tackled the shear behavior of Reinforced Concrete (RC) beams by
using different kinds of strengthening in the shear regions and steel fibers. In the current
paper, the effect of multiple parameters, such as using one percentage of Steel Fibers (SF)
with and without stirrups, without stirrups and steel fibers, on the shear behavior of RC
beams, has been studied and compared by using Finite Element analysis (FE). Three
dimensional (3D) models of (RC) beams are developed and analyzed using ABAQUS
commercial software. The models were validated by comparing their results with the
experimental test. The total number of beams that were modeled for validation purposes
was four. Extensive parametric analysis has been carried out on another twelve beams to
explore the influence of specific parameters, such as using different strengths of concrete,
different flexural reinforcement bars, and laminate in the shear regions. It is concluded
from the results that when a different compressive strength was assigned to RC beams, a
decrease by 31 of beam ultimate strength was recorded when using C25 concrete strength.
On the other hand, an improvement of 29% was observed by assigning concrete
compressive strength C50. As well as another decrease of 18 and 26 kN was observed
when GFRP was used with beams that had stirrups and beams that had both stirrups and
SF. However, the beams recorded a higher number for ductility with using GFRP. In
addition, using laminate with the beam that had both stirrups and SF was not beneficial;
hence, the failure load was increased by only 3%, particularly with the beam that had both
stirrups and SFs

This paper proposes a new strategy to enhance the performance and accuracy of the Spiral
dynamic algorithm (SDA) for use in solving real-world problems by hybridizing the SDA
with the Bacterial Foraging optimization algorithm (BFA). The dynamic step size of SDA
makes it a useful exploitation approach. However, it has limited exploration throughout the
diversification phase, which results in getting trapped at local optima. The optimal
initialization position for the SDA algorithm has been determined with the help of the
chemotactic strategy of the BFA optimization algorithm, which has been utilized to improve
the exploration approach of the SDA. The proposed Hybrid Adaptive Spiral Dynamic
Bacterial Foraging (HASDBF) algorithm is designed so that the chemotaxis phase of bacteria
represents the exploration part of the search operation. In contrast, the SDA represents the
exploitation part.
Additionally, to improve search operation efficiency, the spiral model's radius and angular
displacement are adaptively set according to a linear correlation concerning the fitness
value. An additional phase, the elimination and dispersal phase, is obtained from BFA and
added to the end of the SDA. This phase aims to improve the algorithm's final solution's
accuracy by enhancing the algorithm's search strategy and performance. Simulation tests
are run on unimodal and multimodal standard benchmark functions to verify the proposed
algorithm. The proposed algorithm significantly outperforms SDA and Adaptive SDA (ASDA)
algorithms regarding fitness value and accuracy.