AL-Rafidain Engineering Journal (AREJ)

This study deals with the concept of adaptation in natural systems, and the principles used by these systems to
enable them to respond to changes and perform their functions within the processes of continuous growth. These
principles include static and dynamic characteristics, which are used to match their sustainable characteristics in growth
and adaptation. Here, the importance of fractal geometry emerged in explaining the complex nature with its formations
and characteristics, as it is also able to grow and adapt continuously and interdependently. Thus, it helps designers
achieve adaptation and growth in functionality and spatial requirements in the built environment through time, guided by
sustainable natural systems.
The importance of adaptation emerges as one of the most important strategies for achieving an environment
that is more capable of accepting the processes of modification and change, and thus accommodating changes and
renewable spatial and functional requirements, and conforming to them over time. A building that is more adaptable is
more efficient in being able to respond to changes. The benefits of achieving adaptation in architecture are represented
in the efficient utilization of space, the increase in the life of the building and its compatibility with the changing
requirements of the occupants in a better manner and at a relatively lower cost. This, in turn, leads to a reduction in
relocation and abandonment of buildings and contributes to preserving the environment, by reducing demolition and
construction operations, which result in damage as is well known. Adaptation is associated with a range of economic,
social and environmental benefits, being one of the features of sustainable architecture. And since fractal geometry
derives its structure and material and essential characteristics from nature, which is sustainable by default, it has in turn
become an entry point for employing the characteristics of nature in architecture. The fractal structure\'s ability to grow
and adapt has become echoed and reflected in the work of many architects. Through this, the two main axes of this study
stand out. The first axis includes introducing the vocabulary of adaptation, its characteristics and requirements in
architecture, and the second axis is related to proposing the equivalent principles of adaptation in nature, by using
fractal geometry as a mechanism that can be used to explore and transfer these principles to architectural designs that
contribute to achieving successful and sustainable construction.
The research discusses the hypothesis that adaptation can be a critical factor associated with sustainable
architecture by using fractal geometry tools. This is done by discussing the proposals of many researchers and
crystallizing their ideas to serve the goal of the research, which aims to achieve sustainable architectural design through
the concepts of adaptation. The most important results of the research indicated that there is a harmonious relationship
between the concepts of fractal geometry, including mechanisms dynamic growth, repetition within graduated scales,
symmetry, and others, on the one hand, and between the concepts of sustainable nature with its adaptive characteristics
towards various changes over time, on the other hand.

The off-grid solar photovoltaic system is one of the promising technologies for generating friendly electricity.
Duhok city suffers from energy shortages in that electricity comes from local generators to support national grid. The
aim of the research is to eliminate local generators due to their high costs and noise levels. A photovoltaic (PV) solar
system type (off-grid) was proposed for one villa in AVRO city Duhok. A calculation has been done to select size of the
system and A PV Syst software was adopted to investigate the design of the proposed system and additionally examined
the economic analysis as well as the net profit. The proposed system is used with an average electricity demand of 12.9
kW/day. A typical 3.3 kW PV system was determined to be able to meet the daily power requirements of an entire villa
with 8 panels: two in series and four in parallel where each panel has a rating of 415W. The system includes 8 batteries
of 12 V,200Ah, and a 5-kW inverter with MPPT tracker. The result shows that yearly average of the energy requirement
of villa is 4728.9 kWh and energy available through Solar’s panel is 5999 kWh/year.

The use of technology in the field of urban heritage has increased in recent times due to the
possibilities that contribute to the management of conservation operations. The use of virtual reality systems
is considered as one of the most important methods of digital preservation through the production of 3D models
of historical buildings and then inserting them into interactive environments, such as the use of augmented
reality systems, which allow the user to identify historical buildings through tablets and mobile devices to make
them quickly and accessible. The research problem lies in the absence of studies on re-creating interactive
models of historical buildings in Mosul old city. The current applied research aims to provide a working
methodology to form an interactive model for a lost or damaged historical landmark through a methodology
that works on collecting information sources on the damaged building and trying to rebuild it or recover the
damaged parts of it by linking the information to produce a stereoscopic building , and then linking them to
books and historical sources .So that the user can identify it with a three-dimensional model that appears on
the screen of the mobile phone or tablet after making a digital scan of the relevant book page and using the
Unite AR app

Due to the historical cumulative layers that were formed from the succession of construction, demolition,
and sequential reconstruction, cities have become the essence of diversity, by evoking new urban forms that
contribute to the creation and formulation of their urban heritage. Globally, redevelopment of the riverfront remains
popular and is part of the urban planning agenda. However, this process is still often constrained by a set of strategic
issues and difficulties in the cities of developing countries. The relationship between the urban fabric of the city of
Mosul and its river frontage is a major criterion in evaluating the approaches and approaches to preserving the
main features of the urban landscape of the city.
The current research aims to discuss the integrative preservation as a working methodology for a longterm plan based on previous global experiences and the basic guidelines approved by international laws to submit
proposals for the reconstruction of the river front of ancient Mosul. It also aims to discuss the relationship between
the historical urban fabric and the water environment and highlight the various methods that can be adopted to
develop this essential part of the urban fabric of the city.The research adopts the methodology of comparative
analysis of conservation trends and intervention mechanisms, including integrative conservation, analysis of a
number of relevant international studies, analysis of international conventions concerned with conservation, and
obtaining qualitative data from a group of experts specialized in both aspects of urban preservation and urban
renewal. This is in addition to obtaining quantitative data using the questionnaire method by designing a set of
questions following Likert\'s Five-point Scale method and analyzing them using Microsoft Excel 2010, and applying
them to the case study represented by the riverfront of the old city of Mosul.

Architecture as a human production is considered as the principal source of distinguished elements
within the city; such elements give the city its own identity. The progress of achieving such unique pieces is
regarded as an urban design strategy which requires a particular methodology, depending not only on the
designer but also on the perception of these elements. This paper concentrates on exploring the most important
perceptual mechanisms that affect the recipient in making him distinguish the unique elements-particularly
building- within an urban context. The study is spatially limited to the city of Mosul.
The problem of the current study is constituted in the lack of a comprehensive vision about the
mechanisms affecting the direction of the recipient to realize the unique output, so that the designer can follow
clear mechanisms to reach the realization of a unique building within its context.
This study aims to explore the mechanisms of guiding the recipient to realize uniqueness and the steps
involved, within the different design practices, that affect obtaining a unique building. To achieve this goal, the
research is defined by building the theoretical framework represented by the mechanisms of guiding the recipient
to realize uniqueness, which includes two secondary axes: the first is the mechanisms of realizing uniqueness at
the personal level of the recipient, and the second is the effectiveness of perceiving uniqueness at the level of urban
structure.
The practical side of the study is conducted in two parts; The first is to nominate a number of unique
local products based on the mental image of the users of that urban environment, and the second includes the
application of the learned mechanisms to a number of unique local architectural products according to the
mechanisms of guiding the recipient to realize the uniqueness.
The results show a great variation in the mechanisms that affect the realization of the unique building,
which include the effectiveness of attracting attention, the element of surprise and mystery, the privacy of the
building site, the available field of view and stimulation of the property of perception, and the size of the building
in terms of distinguishing its height or size in its context, contrast with the background, through the type, color and
properties of packaging materials that affect the realization of the unique building.
The study concluded that there is a significant role for the perception mechanisms followed by the
recipient in achieving the uniqueness of the architectural production, as variables that contribute to the visual
assessment of the output among users of the urban environment. These mechanisms vary in the extent of their
impact on directing the perception of the recipient, in addition to the possibility of the influence of more than one
mechanism in achieving the uniqueness of the same production within the urban context.

With the beginning of the twentieth century, the radical change of the fabric shape of the modern city into
vertical complexes, low-cost individual buildings as well as the complet separation of city functions by using private
vehicles as the main means of transportation, result in polluting its environment , and weakening its urban identity. The
current research aims to compare the global sustainable transportation assessments in order to reach the criteria and
indicators which affect sustainable transportation and its requirements, that, in turn, affect the urban fabric and reduce
the negative effects of the modern city. Through the analysis of the most reliable global systems and some of previous
studies and projects, the research paper identifies a set of standards for those systems with regard to sustainable
transport, which directly affect the shape of urban fabric, and which contribute to providing necessary physical
infrastructure for the effective functioning of sustainable transport systems within these communities

Universities worldwide are essential institutions to upgrade society. Recently, the University of Mosul underwent
certain circumstances after the 2003 and 2016 times of wars that varied among urban expansion, renovation, and rebuild
some affected or demolished buildings, roads, walkways, and sidewalks. Hereupon, this research aims at measuring
students´ comfort walking. This research contributes by advocating mobility network development on the main Campus.
Six components involved with comfort walking were addressed namely: personal preferences, connectivity, accessibility,
safety, convenience, and attractiveness. The study focused on the main Campus. Qualitative and quantitative approaches
were adopted in data collection and analysis including observation, photography techniques, and questionnaire survey.
The sample of the study subjected the students who usually walk on the Campus. The findings reveal that the
Campus generally gives the students a comfortable walking experience. Particularly, there is an agreement on connectivity
aspects, moderate evaluation for accessibility aspects, agreement to some extent with safety aspects, moderate evaluation
for convenience aspects, as well as attractiveness aspects. Besides, the findings indicate a requirement for further
improvements especially in providing transportation services in the University for long distances, improving the physical
elements, services, and facilities, which need more maintenance.

In this study, the weights of a number of criteria that affect the selection of the railway track between Mosul
and Fishkhabur on the Iraqi- Syrian- Turkish border are determined. These criteria include ground slope, water
resources, irrigation canals, infrastructure services routes, land use, environmental impact, and soil bearing strength. A
questionnaire is conducted for a group of decision makers, specialists and planners. The Analytic Hierarchical Process
(AHP) technology developed by Saaty is implemented by using pairwise comparison among the criteria. This method is
chosen due to its ease, accuracy and the existence of a specialized computer program to perform the mathematical
calculations, incorporating weights for all forms, and extracting the final weight for choosing the path. The study shows
that the water resources criterion of (29.7%) at a consensus rate of (57%) gets the highest relative importance followed
by the ground slope criterion (21.3%) at a consensus of (49%). The environmental impact criterion of (6.9%) at a
consensus rate of (53%) gets the lowest value of the relative importance

Nondestructive tests \'NDT\' are increasingly becoming necessary tasks to develop accurate measurements
without causing any damage to the tested elements. The outcome of the NDT is vital to determining the safety and
reliability composition of materials. This study aims to investigate the dependability of nondestructive tests using Schmidt
Hammer and Destructive Core Tests in a fire-damaged area. More than hundred stations were considered in the
nondestructive inspection. Destructive core test results were used to assess the NDT results in burned concrete elements.
The results of the comparison, clearly demonstrated the ability of both destructive and nondestructive ways to capture the
strength reductions in fired elements. The NDT test provided an optimistic and higher strength prediction (higher 35-
67%) as compared to destructive tests. Greater optimism NDT results were significantly associated with elements that
have been highly damaged by fire and the strength predictions efficiency were between 60-67%. The results showed
deviations in the mechanical properties of predicted burned concrete strength, by both on-destructive and nondestructive
ways that required strength calibration to the nondestructive test to ensure more reliable assessment. A strength
degradation formula is also suggested and is under review.

To evaluate the possibility of using waste powder material (WPM) produced from moisc tiles polishing as a
sustainble filler in asphalt mixture, some properties of asphalt mastic containing WPM were investigated in this paper,
compared with the common limestone mineral (LSM) filler. The investigated mastic consisted of asphalt and filler at a
mass ratio of 1:1. The rheological properties were tested using the penetration, softening point, ductility, elastic recovery,
Furol viscosity, extensional viscosity, Dynamic Shear Rheometer, temperature susceptibility, compatibility, and Cone
penetration tests. Results indicate the possibility of WPM as sustainble filler derived from mosaic tile polishing facilities
to improve the performance of asphalt. The WPM has better effect on improving the shear, rutting and fatigue resistance
as well as temperature sensitivity of asphalt mastic than LSM.

Most of the loads in the distribution system are inductive loads, due to the nature of household loads, most of which
are reactive power consuming motors. These loads have a low power factor and cause voltage drop and increased power
losses in the wires. The system most affected by power loss and voltage drop is the low-voltage distribution system of 0.4 kV,
due to the large current that passes in this system.
In this research, a simulation of a standard low-voltage radial distribution system (IEEE 30 Bus System) was
carried out in the Power World Simulator Program in order to evaluate and improve the efficiency of the distribution system
by manually installing capacitors at each consumer to correct the power factor to reduce voltage drop and electrical power
losses in wires. The system simulation was conducted at constant loads, and the ineffective power was compensated for by its
equivalent manually, by adding capacitors to keep the power factor close to Unity.
The research aims to study the effect of power factor correction for each consumer on the overall distribution
system efficiency, to be a basis for designing an automatic power factor correction unit that can be installed in homes,
commercial buildings, and small factories. The simulation results were promising in terms of improving the overall system
efficiency and reliability

The increasing use of power-electronics equipment has led to various power quality problems, including current
wave distortion . Also, renewable energies (solar and wind energy ) are increasingly used to supply part of the electrical
load,especially Photovoltaic (PV). The use of PV-STATCOM achieves many benefits, among them mitigating the distortion
of the current wave , improving the power factor , compensatingthe active and reactive power , and improving the system
's stability. This paper deals with mitigating current wave distortion and improving power factors together. This paper
designs a STATCOM Modular Multilevel Converter (MMC) controller with combines reactive power compensation and
harmonicsmitigation for linear load and proposed a simulated six pulse three-phase rectifier as nonlinear load. The pulses
gate of theswitches of the sub -modular converter has been obtained by using a proportional -integral (PI) current
controller with d-q references. The time-domain-based reference method for the reference current extraction is adopted.
MMCSTATCOM were simulated with proposed nonlinear model loads in MATLAB . The simulation result showed that
the developed MMCSTATCOM minimizes the total harmonic distortion below the standards recommended by the IEEE.

Distance protection is considered important and essential in power systems. Due to the development
of distribution systems and the system's topology change from time to time, integrating electric vehicles into
the distribution system leads to an increase in short circuit level and injection of harmonics into the system.
Since the vehicles are continuously variable loads, this leads to difficulty in adjusting the protections that
depend on the current in the process of adjusting them. As a result, distance protection is used in distribution
systems. This paper shows the effect of integrating electric vehicle charging stations on the relay performance
of distance protection in the distribution system. Distance protection relay was built based on artificial neural
networks adapted to the system conditions. The accuracy of the neural network model used for fault detection
was (99.9%), and the error rate in locating the fault was (0.00079%)

This article presents a review of different types of miniaturized rectenna integrated circuits IC used for energy
harvesting applications such as medical applications. The rectenna design consists of two basic components: an embedded
antenna that collects radio-frequency RF energy from the surrounding environment, and the rectifier circuit that converts
AC-RF energy values into DC voltage for usage in low-power electronics devices such as implantable medical devices
(IMDs). Microwave Schottky diodes HSMS-285x and SMS-763x series are used as a voltage doubler rectifier with an
implanted antenna to improve conversion efficiency and the output voltage at a given input power and appropriate load.
There are many challenges in the implantable rectenna IC design such as biocompatibility, miniaturization, patient safety,
compact size, resonant frequency, bandwidth, radiation efficiency, and insensitivity to detuning. This review article
summarizes the overall rectenna research carried out for new different design strategies in implant medical applications
that operated at industrial scientific, and medical (ISM) bands such as 2.45GHz and 5.8GHz.

Electrical power systems operate at 50 Hz. However, generation loss, a sudden increase in loads, or faults in the
system cause disturbances and deviations that destabilize the frequency of electrical power systems. Therefore, there is a need to
study and improve the frequency stability of electrical power systems during disturbances. The present study examines improving
the frequency stability of electrical power system, using a solar photovoltaic (PV) system, a battery energy storage system
(BESS), and underfrequency load-shedding (UFLS) to estimate and control the frequency. The proposed method was tested on a
standard Institute of Electrical and Electronics Engineers' (IEEE®) 9-bus system that was simulated in MATLAB® Simulink. The
simulation results indicate that the used method significantly stabilizes the frequency of electrical power system.

In recent times, Multilevel inverters are considered an essential component of power electronics
with widespread use in a wide range of high-voltage and high-power industrial and commercial applications.
The use of multi-level inverters, also known as MLIs, has been preferred over conventional inverters due to
the characteristics that these MLIs possess. These characteristics include low harmonic distortion caused by
satisfacory performance of MLIs. This paper is concerned with analyzing harmonics to gain a deeper
understanding of the performance of cascaded H-Bridge multilevel inverters (CHB-MLI). The model was
constructed by using MATLAB/SIMULINK. A comparison was made between an asymmetrical cascaded 27
and 31-level multi-level inverter (MLI) by using the Phase disposition sinusoidal Pulse Width Modulation
(PD-SPWM)and Phase Opposition Disposition sinusoidal Pulse Width Modulation (POD-SPWM)
techniques. According to the outcomes of the simulations, 31 levels are better than 27 where Total Harmonic
Distortion ( THD) in 31 levels is lower than 27 levels. The best result obtained during this study is 31 levels
that use (PD-SPWM) technology, where the percentage of total harmonic distortion is small compared to the
rest of the results and equal to 3.63%.

Voltage stability of power systems reflects challenges to the power system operators due to its effect on the
power systems components performances. Therefore, many solutions were invented in order to keep the systems within the
voltage stability accepted limits. Because of the huge expansion of the power grids and the different loads natures on the
grids, many techniques and solutions are used. The On Load Tap Changing Transformer (OLTC) was one of those
techniques. In this paper, a review of past works that deal with the voltage stability limits, voltage stability improvement
ways, OLTC types, the OLTC reverse action, and OLTC effect on voltage stability, in addition to several ways that make
the OLTC work better. are discussed. The paper also sheds the light on the possible ways that may be employed to prevent
the OLTC reverse action.

CT
Rising electricity consumption, rapid depletion of fossil fuels, and the global shift to the use of renewable energy
resources have increased the need to integrate renewable and distributed energy resources (DERs), such as solar photovoltaic
(PV) to power distribution networks. In this paper, the effect of photovoltaic system inverter scalability on reactive power
compensation/absorption in a modified IEEE 13-node distribution network is studied. Power flow analyzes were conducted in
MATLAB / SIMULINK software for different operating conditions to show the effect of reactive power on network voltage
regulation, total harmonic distortion (THD) reduction, and power factor conservation in order to improve the system\'s power
handling capacity. The result shows that the use of the PV system (500 kW) in Bus (671) led to a decrease in the generated power
of the generator by 13.79%, the use of reactive power injection from the inverter of the photovoltaic system on site improved the
voltage profile significantly. Also, the voltage distortion (THD-V) was reduced by 34% when injected with reactive power, and the
current distortion (THD-I) was reduced by 57.65% when the reactive power was absorbed, and the power factor was improved on
site.

Power quality problems in electric systems are one of the important topics that occupy a wide area of interest
to researchers and engineers. The increased use of power electronics circuits has led to improve efficiency and
performance of the equipment; on the other hand, they withdraw a non-sinusoidal current and increase the harmonics
which causes a decrease in the power quality. Also, these electronic devices are sensitive to power quality problems.
However, advanced electronics can be employed to mitigate these problems. The Distribution static synchronous
compensator (D-STATCOM) is one of the Custom Power Devices (CPDs) used for this purpose. D-STATCOM can be
designed with different topologies, algorithms, and techniques of control to mitigate various power quality problems that
face the power system. Selecting the D-STATCOM design depends on the power quality problem that needs to be
mitigated. This paper presents a literature review of D-STATCOM from its beginnings to the present day.

The effect of the various winding connections of three phase two windings transformer on the fault current at the line to
ground (SLG-fault) and the double line to ground (DLG-fault) is studied. The ground faults are unbalanced ; so, the analysis of
these types of short circuit faults is divided into three balanced circuits which are known as symmetrical networks. The zero
sequence impedance appears in some types of transformer connections and its effect is reflected in the fault current value. This
paper examines with help of MATLAB software by simulating a generating station and different transformer connections, the
impact of three-phase two windings transformer connections which occurs on a transformer secondary side to determine which
the connections type of the transformer gives the maximum and minimum zero sequence component of ground fault current.

The theory of automata combines ideas from engineering, linguistics, mathematics, philosophy, etc. The
Entscheidungsproblem asks if it is possible to design a series of steps that replaces a mathematician. An automaton is an
abstract machine that processes data. C. Shannon's theory is today's most popular despite having no relationship with the
other. The Kt system is called "minimal" because it makes no assumptions about the structure of time. In LKt, we have four
monary temporal operators, F, P, G and H, which are mutually interdefinable. Interdefinability means that we will pass
logic in the future is the same as saying I will never fail logic, interpreting not passing logic as failing logic. The minimal
system syntax of temporal logic introduces operators that have the property of being defined in terms of others. Modal
logic studies the reasoning that involves the use of expressions "necessarily" and "possibly". In this article, we will
represent through a finite automaton the temporal logic formula Fp. It allows us to see an acceptance pattern for Fp by
considering two variables: p and q. Kt's axiomatic system of time expresses the idea that both the present and the past are
fixed, if it has always been in the past that it will be some time in the future that p is now. No philosophical argument
supports deterministic time flow; the logic of time must be open.Temporal logic has revived many old problems, from the
Megaric-Stoics to the minimal system of temporal logic. Our work suggests that the future operators of system Kt follow
an evaluation pattern, but we must be cautious because this pattern can only apply to models whose time flow is based on
instants and precedence relations.

The present study is an experimental investigation to improve the performance of the air conditioning unit (ACU) by
precooling the condenser with a cooling water loop using a water heat exchanger with the employment of energy and exergy analyses
under various ambient temperatures between 30 – 45C at different inlet water temperatures; 15, 19, 24 and 30C and water
flowrates; 9, 11, 14 and 15.8 L/min. The results indicated that the cooling water loop have a large effect on the exergy destructions
as compared with those of the no water case. When a cooling water loop is used, the compressor, evaporator, and expansion valve
irreversibilities reduced. The exergy efficiency of the unit decreases as Tamb increases to about 23%; while, the exergy efficiency
increases when cooling water loop is used depending on the inlet water temperature and water flowrates. The maximum
enhancement in the exergy efficiency is obtained at high water flowrate for Twi = 15C with a percentage value about 13% as
compared with those of the conventional ACU.

About 40% of the world's primary energy is used by buildings. This indicates that the bulk of greenhouse gas
emissions are caused by buildings. In this investigation, the decrement factor (DF) and time lag (TL) of a new 3D-printed
model are experimentally determined. It is really time to cut back on such energy consumption to lessen buildings'
negative environmental effects. The introduction of new model 3D-printing blocks with high thermal inertia might be a
way to lower the building's energy usage. Decrement factors and time lag are characteristics of thermal inertia. In this
investigation, the decrement factor and time lag of a new 3D-printed model are experimentally determined. At the
University of Salahadin's College of Engineering, a pilot house measuring 1 m x 0.45 m x 0.45 m is constructed
specifically for this application. The equivalent temperatures of the inside (room one) and outside (room two) are used to
determine the decrement factor and time lag. The findings indicate that using the new 3D-block model, the time lag is
around 120 minutes, and the decrement factor is approximately 0.34. The 3D-printing block enables a 4.5°C reduction in
the peak interior temperature. Since temperature changes outside are not noticeable, less energy is used to cool the
structure during warm weather.

The current paper presents an experimental work that had been implemented to observe the
performance of an improved solar air heater and compared it with that of a conventional double-pass flat
plate solar air heater. Improvements that have been added include the use of a V-shaped corrugated plate at
an angle of 60 degrees, the addition of wood baffles in the lower pass and the use of phase-changing
materials PCM as well as air recycling conditions. The heater was designed and tested under the weather
conditions prevailing in the Duhok Governorate (latitude 36° 52' 1.52" N and longitude 42° 59' 18.42" E) in
the Kurdistan Region of Iraq. The phase-changing material PCM is paraffin wax. The gathered results
showed that the improvements that were added to the solar air heater significantly improved the performance
at different mass flow values (0.037, 0.057, 0.077 kg/sec). For example, the maximum values of useful heat
transfer at mass flow rates (0.037, 0.057, and 0.077kg/s) are 1.68, 1.86, and 2.34 kW, respectively, and the
daily efficiency for improving and conventional heater value at mass flow rate 0.037kg/s for 15,16, and 17 of
February on 2022 was (84% and 45%), (86% and 46%), and (91% and 60%), respectively

The tracking system that uses for PV solar systems has a vital role to improve the energy performance of the
solar panel. In the present study, the performance of both the fixed PV solar system and single – axis tracking PV solar
system is investigated experimentally. The power for each PV solar panel is 150 W. The performances of the two systems
are compared to display the efficient improvement of a single-axis solar tracking (SAST) system with fixed solar (FS)
system under the climate conditions in the Zakho/ Kurdistan region/ Iraq. A mechanical tracking device with a controller
and linear actuator was designed, and its performance was comprehensively investigated with a PV system. The findings
for a sunny day due to the use of a single axis tracking system with a solar panel as compared with those of a fixed panel,
that the enhancement in the overall power generation and electrical efficiency are about 28 % and 29 %, respectively.

The current work explores a trial forced convective heat move from rectangular blades on an upward surface
at low Reynolds numbers. The heat removal for a proper number of punctured and non-punctured fins, fin dividing, and
length was estimated in an upward air stream for fluctuating inlet air speed and some way or another low info heat
power somewhere in the range of 20W and 70W. The characteristics are investigated for rectangular, circular, and Vshape perforated fin array against non-perforated one. The impact of different boundaries, like heat input with various
liquid stream speed on average coefficient of heat transfer (h) improvement has been considered. The impact of the
Nusselt numberand Reynolds number, were practically examined. The heat loss has been improved by increasing the heat
transfer coefficient between the fin total surface and its encompassing, through increasing the area of heat to remove all
out surface through fin perforations. The trial relations have been differentiated by correlating Nu and Re for nonpunctured plate heat sink, the reach 6*103  Re  19*103, and Pr  0.7 with error ±7%, and punctured finned plate heat
sink with the reach 6*103  Re  20*103, and Pr  0.7 with a deviation factor R2=0.995.

The performance of thermal systems, like heating and cooling systems, depends on a number of factors such as the
geometrical shape, the working fluid used to transfer or store heat, and the operating conditions. Accordingly, many studies
concentrated on improving the thermal performance of such systems and raising their thermal efficiency by modifying their
geometry or using phase-changing materials. Therefore, this work is reviewing the previous studies that dealt with modifying
the geometry, by adding annular or longitudinal fins on the main tube of the heat exchanger, and employing different types of
phase change materials. This article also presents the previous scientific articles that investigated the effects of changing the
location and the orientation of the fins. For the reviewed studies in this article, it is worth mentioning that the numerical
investigations outnumbered the experimental ones as the authors focused on finding the optimal design of the studied thermal
systems. Furthermore, the previous studies employed phase-change materials, e.g. fatty acids, waxes, and salts, due to their
ability to store energy and reuse it in a wide range of applications.

In a larger sense, "green computing" refers to strategies and procedures for creating, utilizing, and disposing
of computer resources in three ways: maintaining total computing performance, minimizing the impact on the
environment, and maintaining overall computing performance. This entails using less dangerous materials, getting the
most usage possible out of a product while using the least amount of energy possible, as well as making old items and the
garbage more reusable, recyclable, and biodegradable. Many businesses are making efforts to lessen the negative effects
of activities on the environment. The framework Convention on Climate Change of the United Nations (UNFCC)is a
global environmental agreement whose goal is to keep greenhouse gas emissions stable to a degree that would prevent
adverse anthropogenic interference with the environment. Sustainable development entails growth that doesn't jeopardize
the needs of coming generations. That is achieving human development goals while protecting the ecosystems and
natural resources that are essential to civilization. The relevance of green computing for sustainable development is
emphasized in this paper's assessment of many significant recent studies on the subject.

Industrial IoT (Industrial IoT) is a new promising technology which can be used to increase the amount of
productions with high qualities. Industrial IoT technologies guarantee full control to the processes remotely through the
internet which can reduce the number of workers in the field. As a result, this can reduce the percentage of worker
injuries and accidents in addition to the total costs. The Industrial IoT systems are attractive targets to attackers. For this
reason, these systems require high levels of security since such levels have direct effects on physical devices which may
be dangerous on human life and safety. To guarantee high level of security, a combination between Information
Technologies (IT) and Operation Technologies (OT) with new innovative methods should take place. In this paper, many
new technologies and security methods are reviewed with their possible attacks in order to provide Industrial IoT
infrastructure designers with the required information to take them into consideration. Also, differences and
convergences between both classical Information Technology (IT) and operational Technology (OT) and their relations
to the Industrial IoT systems are investigated with the possible attacks on each layer of the IT and the OT.

In this research, an Oldham coupling is used, and it has been modified to obtain new features. The modification
is made on the intermediate part of the Oldham coupling and hence a kinematic model is approached, and two new
applications are found. The proposed mechanism can be used as a function generator for some specific functions such as
cardioid for the ratio, crank/shift=1, and the second finding as a sort of quick return mechanism. The results of the
mathematical model show a good agreement with those of

This paper presents a security paradigm for edge devices to defend against various internal and
external threats. The first section of the manuscript proposes employing machine learning models to identify
MQTT-based (Message Queue Telemetry Transport) attacks using the Intrusion Detection and Prevention
System (IDPS) for edge nodes. Because the Machine Learning (ML) model cannot be trained directly on lowperformance platforms (such as edge devices),a new methodology for updating ML models is proposed to
provide a tradeoff between the model performance and the computational complexity. The proposed
methodology involves training the model on a high-performance computing platform and then installing the
trained model as a detection engine on low-performance platforms (such as the edge node of the edge layer)
to identify new attacks. Multiple security techniques have been employed in the second half of the manuscript
to verify that the exchanged trained model and the exchanged data files are valid and undiscoverable
(information authenticity and privacy) and that the source (such as a fog node or edge device) is indeed what
it it claimed to be (source authentication and message integrity). Finally, the proposed security paradigm is
found to be effective against various internal and external threats and can be applied to a low-cost singleboard computer (SBC)

The traditional centralized cloud computing paradigm confronts several problems, including a lack of capacity,
high latency, and network failure, due to the rapid expansion of IoT (Internet of Things) applications. Fog Computing
brings cloud computing and IoT devices closer to addressing these issues. Instead of transferring IoT data to the cloud, the
Fog allows local processing and storage of IoT data in IoT devices. Fog Computing offers services with a quicker response
time and higher quality than the cloud. Therefore, Fog Computing may be considered the greatest option for enabling the
IoT to provide efficient and secure services to many IoT users. In this paper, we define the term "Fog Computing," examine
its architecture and list its features. We also talk about other related work and emphasize it.