Anbar Journal of Engineering Sciences

Previous studies showed that fire incidents cause a
considerable deterioration of limestone samples'
engineering and physical properties. Various laboratory
tests were used in previous studies to investigate the
properties of limestone. These tests included destructive
and non-destructive tests like the hammer test, ultrasonic
pulse velocity test, water-capillary rise test, and water
transfer properties test, as well as destructive tests like
the unconfined compression test and Brazilian tensile
test. The stones of buildings exposed to fire are
occasionally assessed on the site. This study analysed the
physical and mechanical changes that occurred to the
limestone samples when subjected to high temperatures,
the damage mechanism, and laboratory or field damage
assessment. This study also includes a review of the most
significant studies that looked at how alternative cooling
techniques—rapid water cooling or gradual air cooling—
affect stone samples subjected to high temperatures and
compared the behaviour of the samples in each scenario.

Solar cells play a vital role in renewable energy systems, and ongoing
research is dedicated to enhancing their power efficiency and longevity.
Advancements in perovskite solar cells, particularly in power
conversion efficiency (PCE), have shown significant progress,
confirming its viability as a technology. Perovskite solar cells have
achieved power conversion efficiency (PCE) levels of up to 25.5%,
comparable to conventional photovoltaic technologies like silicon,
gallium arsenide, and cadmium telluride. The substantial enhancement
in power conversion efficiency figures over the last decade has shown a
remarkable advancement in the efficiency of perovskite solar cells. This
study examines the trajectory of perovskite solar cells in becoming
economically feasible and generally embraced as a critical renewable
energy technology. The advancement of flexible and wearable solar
cells, together with miniature solar-powered sensors, has increased the
efficiency of solar cell power production. Perovskite solar cells have
shown a specific power of 23 W/g, much higher than traditional silicon
or gallium arsenide solar cells. Further research is needed to address
the challenges related to perovskite solar cells' stability and power
conversion efficiency. Perovskite solar cells integrated with energy
storage units have the potential to enhance the overall efficiency of the
system. This study discusses an approach to improve the efficiency of
novel solar cells, specifically focusing on lead-free tin-based perovskite
solar cells and tandem solar cells. The advancement of technology in
thin films, such as hybrid nanocomposite thin films and quantum dotsensitive solar cells, has the potential to improve the efficiency of solar
cells. The primary outcome of this study is derived from the following
inference: incorporating plasmatic nanostructures into thermal energy
systems will enhance their efficiency and sustainability by integrating
solar energy

In this current experimental research, the amount of
improvement in the thermal conductivity of HEC hybrid epoxy
resins was studied by adding copper oxide nanoparticles CuONp
and carbon nanotubes (CNTs) as hybrid additives in different
proportions to select the sample with the highest thermal
conductivity value to include it in the design of the Flat Plate
Solar Collector FPSC as Thermal Interface Material TIM reduces
thermal resistance between the absorber plate and the tube.
Four groups of samples were prepared using a mass balance
with a sensitivity of 0.01g and a magnetic mixing device, then
poured into cubic plastic molds to take the shape of the sample.
The first group consists of one sample of pure epoxy to calibrate
the thermal properties testing device through it. The second
group consists of five samples of epoxy loaded with CNTs by
weight (1, 3, 5, 7.5, 10) %. The third group consists of five
samples of epoxy loaded with CuONp with weight percentages of
(1, 3, 5, 7.5, 10) %. The fourth group consists of five samples of
epoxy loaded with CuONp and CNTs combined in weight
percentages of (1, 3, 5, 7.5, 10) %. The thermal conductivity of
the samples was measured experimentally using the hot disk
analyzer technique to measure thermal specifications. After
comparing the thermal conductivity values of the samples, the
highest value was 1.57 W/mK for the HEC sample loaded with
10% CNTs, which represents 9.23 times higher than pure epoxy.

The direct sequence (DS) spread spectrum
communication technique is widely regarded as one of
the most effective methods of mitigating the effects of a
repeating jammer in military communications systems.
The proposed system coupled DS with multiple
frequency shift keying (DS/MFSK). It is comprised of a
transmitter and a receiver. Non-coherent demodulation
is examined, as are the spreading sequences in question.
The effect of AWGN and Rayleigh fading channels on the
proposed approach's bit error rate (BER) is examined.
The investigation demonstrates that even with an 8 dB
signal-to-noise ratio, superior outcomes can be achieved;
this study's suggested endeavor is to create a novel
transceiver system built on the DS/MFSK modular
architecture. MFSK modulation prevents multiple-access
interference, while DS is typically employed to boost
system efficiency across erratic fading. Test results show
that reliability on the AWGN channel decreases a little
while reliability is greatly enhanced by Rayleigh fading.
Moreover, notable improvements in bandwidth
efficiency are achieved.

These systems show great promise by converting waste heat from
photovoltaic modules into additional electrical power. The study
analyzes the performance and efficiency of the hybrid PV-TEG systems
under varying conditions, such as different solar concentration ratios,
cooling methods, and materials. While these innovations promise to
improve system efficiency, the review also identifies several
challenges, including increased thermal resistance, higher system
costs, and the minimal temperature difference across the TEG, which
significantly limits its performance. This limitation, where the
temperature differential is often too small to be effectively harnessed,
reduces the TEG's overall efficiency and hinders the integrated
system's potential gains. The review underscores the need for urgent
and extensive research to develop optimized design configurations,
durable mathematical models, and further experimental validation to
ensure the practical viability of these systems under diverse
environmental conditions. Despite these challenges, the potential of
PV-TEG systems to revolutionize solar energy technologies is
undeniable.PV-TEG performance is intricately linked to
environmental conditions: higher solar radiation boosts efficiency, but
increased ambient temperatures reduce it. TEGs often hinder PV
cooling, yielding minimal efficiency gains. Non-uniform heat and lowtemperature differences across TEGs further decrease performance.
While hybrids can improve power conversion, high costs limit
feasibility. However, with strategies such as enhancing solar
concentration, using effective cooling methods like water or
nanofluids, and advanced materials like phase change materials, the
efficiency and reliability of these systems can be significantly
improved

Heat exchangers are considered essential parts in many industrial
applications. The construction process for heat exchangers is completely
complex because accurate measurements of the penalty of pressure-drop
and the rate of heat transfer are needed. Designing a compact heat
exchanger with a high heat transfer rate, while utilizing the least amount
of pumping power, is the main design challenge. The most recent
investigations (including experimental results, numerical models, and
analytical solutions) in the field of circular tube heat exchangers in general,
and twisted tapes and wire coils in particular, are covered in this review
article, which has more than 90 references. The enhancement techniques
in heat exchangers tubes can generally be separated into three groups:
active, passive, and hybrid (compound) approaches. This article reviews
the literature on advancements made in passive enhancement approaches,
with a specific focus on two types of passive promoters that employ
twisted tapes and wire coils. The main contribution of this research is to
highlight the behavior and structure of fluid flow and the heat transfer
features for the twisted tapes and the wire coils. It also explains how these
passive promoters can be used in circular tube heat exchangers to improve
hydrothermal performance. Where, the installation of wire coils and
twisted tapes considerably alters the flow pattern and aids in the
improvement of heat transfer. Where, comprehending the behavior of
fluid flow is crucial and contributes to the enhancement of heat transfer.
Twisted tapes are less effective in turbulent flow than wire coils because
they obstruct the flow, which results in a significant pressure reduction.
When it comes to turbulent flow, the thermohydraulic performance of
twisted tapes is lower to that of wire coils.

Deep mixing technology is used to improve the engineering
properties of soil. In this review, previous studies on the
properties and problems of weak soils were collected and
explained, focusing on silty soils found globally and locally. The
study also includes a discussion of physical and chemical
improvement methods, specifically (cement columns). The
advantages of deep mixing technology are also covered from an
engineering and economic point of view, as well as its
relationship to the environmental impact, as it is one of the
sustainable development techniques due to its use of
environmentally friendly materials. In addition, one of the
objectives of this research is to study the methods of adding
cement, whether in the form of powder (dry method) or mortar
(wet method). A comparison was made between them to clarify
the advantages and disadvantages. It was found that what
distinguishes the use of the dry method from the wet method
is that the former is more common. The method's effectiveness
depends on the soil's moisture content, so the technique is
ineffective in soils with less than 30% water content. As cement
hydration produces a cementitious gel (CSH) that binds soil
particles together, leading to early strength gain, pozzolanic
reactions cause increased shear strength and decreased soil
compressibility. Finally, some recommendations are included
in this article to understand the behavior of cement columns in
improving soil and avoiding problems.

This work presents a compact reconfigurable antenna
based on fractal geometry. The investigation discusses the
challenges of lower antenna gain and bandwidth, critical
for efficient data propagation in 5G systems, particularly
for low-profile devices. Its goal is to develop a small,
multiband antenna capable of operating in all current and
future 5G bands and improve bandwidth and gain for mmwave and sub-6 GHz applications. The proposed design
covers the sub-6 band (2.8, 3.9, 4, 6.2) GHz and the mmwave band (24.4, 27.1, 28.5, 29.3, 30.6, 33.9, 34.6, 35.2,
38.8, 44.4, 45.1, 59.7, 61.5, 62.3, 65.2, 67.4 and 69.5) GHz
with S11 less than -10 dB. A maximum gain of 12.8 dB and
a radiation efficiency of 94% are achieved. A partial ground
plane with a 50 Ω feed line is used in this design. The
antenna is printed on a Roger RT 5880 substrate with a
relative dielectric constant 2.2 with a total dimension of
35×32.5×0.8 mm³. The proposed design is simulated using
CST software, ensuring accurate calculations and
performance evaluation.

Diesel electrical generators are essential for providing
reliable backup power during grid outages, ensuring the
continuous operation of critical services such as hospitals,
industries, and communication systems. These generators
require instantaneous monitoring and control to optimize
their performance and longevity. The Internet of Things
facilitates efficient monitoring and enables remote control
with a faster response time than human intervention,
thereby helping to prevent potential damage or system
failures. This research introduced the Internet of Things
technology and its general architecture. The study first
presented an abstract framework of IoT-based monitoring
and controlling technology, divided into three layers:
perception, network, and application. It then discussed the
terminology related to electrical generators, the
parameters monitored, and their operational
environments. In addition, the advantages and challenges
associated with integrating it with electrical generators
were discussed. Finally, the research reviewed and
analyzed several practical applications and case studies
integrating IoT with diesel electrical generators,
highlighting key challenges and proposing solutions. This
work provided theoretical and practical insights into IoTbased monitoring and control systems for electrical
generators

CAPTCHA, which stands for Completely Automated Public
Turing Test to Tell Computers and Humans Apart, is a
commonly employed security measure to distinguish
between humans and computers. The Turing Test, designed
to guarantee network security, is the foundation of this
security technique. Usability is a crucial concern that can
prevent human users from engaging in laborious and timeconsuming tasks. When designing CAPTCHA, security and
usability must be addressed simultaneously. When designing
CAPTCHA, it is crucial to address security and usability
simultaneously. A concerted effort is required to protect
online data and guarantee privacy and security. The personal
information of Internet users remains susceptible to theft.
This study uses an information extraction technique called
CAPTCHA to investigate the hazards associated with violating
user privacy. It is a highly harmful process due to hacking,
theft, unauthorized reuse, and the breach of user information.
This study proposes a privacy preservation system
employing concurrent encryption techniques, multilateral
security computing, and zero-knowledge proof. The objective
is to create a system that allows for uncomplicated and secure
puzzle-solving using dice gas. CAPTCHA limits access to
users' information. In the overview and application of
evidentiary measurable methods, we can draw significant
conclusions about the more extensive client group's
discernments and encounters with CAPTCHA as a privacypreserving component.

Advanced prosthetics are a crucial aspect of rehabilitation
technology and are receiving increased attention globally.
Approximately 2 million people require prosthetic limbs,
presenting opportunities for enhancing their quality of life. Stateof-the-art technologies such as realistic arms and myoelectric
prostheses are gaining popularity. Progress in sensor technology,
artificial intelligence, and materials has driven the field forward.
Various types of controllers, including direct, pattern recognition,
and proportional-derivative, have been developed. Integration of
material science, computer science, artificial intelligence, and
neurology has facilitated controller advancements. Techniques
like targeted muscle reinnervation and Osseo integrated
prostheses offer improved surgical options. Gesture recognition
technologies and intelligent sensors are enhancing hand control.
Future advancements will involve machine learning, artificial
intelligence, and sensing techniques, while ethical concerns must
be addressed. Advanced myoelectric prostheses, also known as
myocontrolled or lower-limb micromod investigative prostheses,
have a patient acceptance rate of 75% to 80%. However, while
these methods offer advantages, there are also drawbacks.
Integrating different types of controllers for these smart
prostheses and enhancing the overall device's strength and
robustness will have a significant impact. This discussion focuses
on various types of smart prosthetic controllers, dividing muscle
activity into extracellular myoelectric potential and EEG signals.