Wasit Journal of Engineering Sciences

Before the invention of solar panels, solar energy had been used for millions of years. To survive and increase many forms of life, people rely on sunlight. For example, use sunlight for warmth and have only recently begun to use the sun's energy to generate renewable and sustainable electricity. The widespread use of photovoltaic PV systems as a source of renewable energy-derived electricity has prompted researchers to investigate the factors that influence their performance. This paper presents an analytical study for assessing the performance of a 120 Wp PV module. This experiment was conducted at Al-Nasiriyah city ( 31.03 N, 46.16E ). At 180˚ south, and 45˚ elevation, the solar panel is omitted. Using solar panels, solar energy is converted into electrical energy that can power an entire building. The power production from the solar panel depends on several identified factors. In February and June, the solar panel tested the effect of cloud cover, rain, relative humidity and wind velocity. On rainy and cloudy days, average power and irradiance are reduced by 93.32 %, 93.77 %, and 79.97 %, 77.34 %, respectively, when compared to power and irradiance on a clear day (8th February) 693 W/m2 and 76.55 W. Humidity has an inverse relationship with voltage, current, and power. It means that as humidity rises, the value of voltage, current, and power decreases. The performance of a solar panel is directly proportional to the wind velocity. The temperature is inversely proportional to wind velocity, i.e. as wind velocity increases, the temperature of the solar cell module decreases. The results of this study have been analyzed and discussed.

In this article, an open source monitoring system based on Internet of Thing (IoT) is designed to monitor electrical energy consumption. This system provides real-time information about energy consumption over time. To implement this system, sensors were used to measure data, a Raspberry as an application server to display and store data, and microcontrollers to collect information. The process of data transfer via the Internet using the Message Queuing Telemetry Transport (MQTT (protocol between the microcontroller and the server. Through the experimental results obtained from the proposed system, the voltage, current, active power and power consumption were successfully recorded.

The effects of various environmental factors have been studied on the efficiency of the PV module as an essential part of the work and how to enhance its efficiency by reducing the influences environmental factors. The study deals with the efficiency of PV module and how to calculate and improve them. The measurements were made from December 2020 to August 2021 at 9 am to 5 pm for the weather of the city of Nasiriyah. The examination a single PV module is used, which gave an PMAX equal to 10 Watt. The most important has been studied on the PV is the temperature, whenever its grateful that led to decline in the output voltage and slight decrease in the output current. The output current PV module increased when the rise in the solar irradiance. To mitigate the impact of this factor, air cooling and water cooling had been used through cooling techniques by using DC fan, cooling blocks and water douche. It is clear that from our work we have improve efficiency of the module during the hot weather by 18% from using (air cooling and water cooling) techniques together. For another factors, such as dust, shadow, and exhaust smoke, showed factors no less an important factor should be besides temperature. The greater the quantity of these effects on the surface of the PV module, the more reduce in its efficiency. The influence of these factors appears to significantly reduce the output current due to its blocking of solar irradiance from PV module led to drop in the output voltage.

Non-Orthogonal Multiple Access (NOMA) is a possible multiple access option for the coming generation of wireless communications that has a higher SE and takes advantage of network resource reuse. As a result, academic and industry researchers have recently looked into the error performance and capacity of NOMA schemes. Because of the non-orthogonal nature of NOMA technique, the main disadvantage is users’ interference, which is normally mitigated using interference cancellation techniques such as Successive Interference Cancellation (SIC) at the receivers. In this paper, we investigate the performance of NOMA and the power allocation strategy utilized on BER. We used BASK modulation with Rayleigh fading channel and AWGN channel. The numerical results show that NOMA works well in equal and different distances between users.

It is critical to utilize a good model for predicting acceptable and optimum frequencies while designing and planning for the future generation wireless communications system\'s channel. This paper explains how the weather conditions affect the strength of the transmitted signal in various environments and circumstances, as well as how the mmWave behaves as it passes through free space and the atmosphere. An NYUSIM simulator package is used for predicting the performance of the channel for two months (January and July). Two frequencies were used, 38 GHz and 73 GHz to test the channel performance and which frequency is the best suited for the Kut city environment. The simulation results shown that an agreement with the 38 GHz for its lower path loss and acceptable received power. The weather database was real and actual obtained from the Iraqi meteorological organization and seismology reports consist of (rain, fog and temperature). The result for both directional and omnidirectional power delay profile showed a great agreement at 38 GHz for the two months (January and July), where the path loss and received power at 38 GHz for January is 127 dB and -47.2 dBm respectively, where for 73 GHz the path loss is 135.4 dB and with a received power of -55.7 dBm. At July the path loss and received power for 38 GHz and 73 GHz is (123 dB, -43.2 dBm) and (130 dB, -43.2 dBm) respectively.

Reconfigurable intelligent surfaces (RISs) have emerged as promising contenders for enabling sixth-generation (6G) physical wireless platforms. RISs fine-tune wireless networks to optimize the spectrum and energy use. This article explores the design challenge of a joint beamforming strategy for increasing throughput at the AP and RIS sides. To address this challenging problem, we created an iterative algorithm, that makes use of the Duality Theory and the Alternating Optimization technique called the DAO algorithm. Due to the given problem's non-convexity and difficulty with variable coupling, the proposed Algorithm divides the optimization problem of the coupled variables into four distinct optimization sub-problems by introducing new supporting variables. The alternate optimization strategy handles the issue sequentially by iteratively updating these new variables, the active beamformer, and the non-active beamformer. Finally, the simulation results indicate that we achieve about a 30% spectrum boost over the standard network without RIS for a certain system and circumstances scenario.

The new concept of Beamspace Multiple Input Multiple Output system (BS-MIMO) was developed to address the issue of reduced Energy Efficiency (EE) of the traditional MIMO in millimeter-Wave (mm-Wave) wireless communication systems by decreases the large number of radio frequency chains (RF-chains) while maintaining the same number of antennas in those systems. On the other hand, a fewer RF-Chains leads to a smaller number of users that the system can serve as a result of the number of users that can be served must be equal to/or less than the RF-chains’ number. To overcome the above issue, the BS-MIMO is proposed to be integrated with Non-Orthogonal Multiple-Access (NOMA) scheme to produce the novel approach of BS-MIMO-NOMA. As a result, the novel scheme is capable of serving a group of users with correlated channels via a single RF-chain. In this paper, we will address the issue of EE of the above-mentioned communication systems. Specifically, we propose and develop an iterative algorithm with a low complexity that achieves near-perfect performance. The proposed scheme, named MSE-DPA (for Mean-Square-Error-Based Dynamic Power Allocation Algorithm), is checked to ensure this validity of Figure-of-Merit. The simulation results indicate that the EE is approximately 85% greater than that of traditional (fully-digital) MIMO systems for a certain fair system and environment scenario.

The thought of non-orthogonal multiple access (NOMA) are given as a potential radio access method for versatile correspondence networks past the fourth era (4G). As opposed to current long haul development radio access procedures, non-symmetrical different access involves the power space for client multiplexing at the transmitter and utilizations a successive obstruction dropping recipient as the pattern collector conspire, considering future cell phone advancement. Non-symmetrical different access is feasible to serve various clients simultaneously and recurrence. For 5G wireless communication networks, non-orthogonal multiple access (NOMA) and millimeter wave (mm-Wave) communications are interesting technologies. The performance of partially connected hybrid beamforming (PC-H-BF), a low-cost partially connected hybrid beamforming (H-BF) with a quick convergence sub-optimal power allocation algorithm, was explored in this work. A low-cost hybrid beam forming technique, as well as a dynamic threshold users' grouping mechanism, were created. In addition, to boost information flow, the sub-optimal inert-beam and intra-beam dynamic power allocation tasks are implemented using a low-complexity iterative maximization technique.

Despite of the economic advantages provided by the voided slabs, their design against punching shear failure, as suggested by the current building codes, are based on the equations derived from tests on flat slabs. Previous tests on voided slabs showed that the punching shear capacity of such slabs are different from that of flat slabs due to the differences in cross-sections. This paper reviews the previous works conducted to investigate the punching shear behavior of voided slabs. In addition, it evaluates the punching shear design provisions of the current building codes using the test results of voided slabs from literature. It was found that the punching shear design equations of the current building codes are inconsistent when they applied to estimate the punching shear capacities of voided slabs

A broad-crested weir is one of the simplest and oldest hydraulic structures.It was used to measure flow regulate flow depth and control flood passage. Open channel flow measurement requirements are based on the experiments performed to evaluate the empirical discharge coefficients and equations. The aim of this study is to develop the stage-discharge relationships using incomplete self-similarity theory and traditional methods for calculating the discharge coefficient (Cds) and to determine which method is the most effective. All experiments were carried out in a channel with a cross-section of (0.5 × 0.5) m and a length of 15 m. 125 experiments were carried out on 25 physical models of a broad crested weir with a rounded edge, under submerged flow conditions. The results showed, after comparing the two methods, and by calculating the mean absolute relative error (MARE) for discharges . It is equal to (4.25%) using the incomplete self-similarity theory, and it is equal to (7.05) by using the traditional method. Thus, the incomplete self-similarity formula is more accurate than the other method.

The essential objective of this study is the development of an appropriate model to obtain the low cost optimization design of the sewage network. The complexity and the huge number of discrete and non-linear constraints in problems of sewage system design make their treatment important. For this aim, an adaptive model of the Genetic Algorithm (GA) of efficient and effective optimization design with a consistent layout is proposed. The MATLAB code was used to optimize the sewage network for the Al Jafriya neighborhood and Al Kut commercial center. Spectral analysis of the Tigris River was also carried out for the area of the estuaries of the studied network to find out the extent of pollution due to the network being a joint network (rain and sewage). According to the obtained results, the developed model achieved the optimum solution with the minimum cost and least generations number. It can be also noticed that the estuaries of the studied storm system have a significant influence on the quality of the river water. Thus, this research proposes the implementation and management of an isolated sewage system that is routed to wastewater treatment plants.

The expansive soils can be founded in various regions and extent areas in the south, middle and north of Iraq. Damage to these soils may appear immediately after construction within five years, or it may take several years until something happen to disturb to moisture structure of the soil. This work aims to find the relation between Atterberg limits, swelling potential, and swelling pressure for five samples. This work is projected to forecast the volume changes in site soil associated with the changes in soil plasticity. The behavior of an expansive soil (bentonite sand mixture) (B-S) subjected to the Atterberg limits test and swelling test were studied. Also, it was found that simple classification tests can provide reasonable estimates of field edges. The potential probability forecasts using the consolidation standard were sometimes low, often as little as possible compared to field observations. Predictions based on the soil suction method provided reasonable higher limits for all test sites.

Despite that concrete is a fire-resisting construction material, its microstructure suffers significant chemical and physical changes when subjected to temperatures higher than 400 oC. Therefore, the combined effect of unexpected impacts and fire can lead to the collapse of the structure. To evaluate this combined effect, an experimental program was directed in this study using the ACI 544-2R repeated impact test method. Shallow cylindrical specimens with 150 mm diameter and 64 mm depth were prepared to evaluate the cracking and failure impact strengths of normal strength concrete (NC) and engineered cementitious composites (ECC). The ECC mixture was reinforced with 2% of polypropylene fibers. In addition to the impact strength, the compressive and flexural strengths of NC and ECC mixtures were also investigated. The impact, compressive and flexural tests were performed on unheated specimens and others heated to 500 oC to evaluate the residual strengths of NC and ECC mixtures. The results showed that before heating, ECC exhibited a failure impact performance that is approximately 6 times more ductile than that of NC, where the retained failure impact numbers of NC and ECC were 57 and 259 blows, respectively. However, both mixtures lost approximately 95% of their impact strengths after exposure to 500 oC. 240

The energy storage is the detention of energy at one time to utilize the for another time. The aim of this work is to enhance the storing time in a hot water storage tank as long period as possible by filling the tank with a suitable porous media and the best filling level of the packed bed material. This paper deals with the methods of thermal energy storage and its applications in the region of systems of solar water heating along with system of solar air heating and the substances used to preserve that thermal energy professionally. The experiments were conducted for normal household use for a family of five persons using a solar heater consisting of a storage tank of 120 liters and a solar collector of 20 vacuum tubes in addition to a tank for storing porous media with a capacity of 50 liters. The experiments were conducted without using porous media and using different levels of porous media (150, 300, 450 mm). The results showed that an increase in the level of porous media contributes to the supply of hot water at a useful temperature for domestic use (above 20 oC) throughout the day.Where 256 liters of hot water was consumed in the first experiment, 273 liters in the second experiment, 273 liters in the third experiment, 261 liters in the fourth experiment, and 207 liters in the fifth experiment

With the development of building construction engineering and the way to obtain energy from natural sources, the sun has become an important source to avail from thermal energy. In this research, the study of the long-term thermal performance of a passive solar heating system containing an absorber and storage wall was done by using the general design utilizability Method The equations of the mathematical model for this system were solved using the MATLAB environment program. In order to calculate the values of the solar refractive index (f) for this system for the four months of the winter season (November to February). The climatic conditions during these months are the daily values based on the monthly average in the city of Kut (Iraq). Since the best type of wall is the concrete wall, changes are made to this type of wall. A number of variables that affect the performance of the wall have been changed, including in it = wall area, wall thickness. The results showed that increasing the wall area and decreasing the thickness leads to an increase in the value of the solar refractive index, and the maximum values of the solar refractive factor were found during November, and the concrete material is the best performing material among brick and stone material, according to previous studies.

Thermal insulation in the building walls is an important factor to reduce heat transfer from the external environment, thus reducing the demand for air conditioning and achieving thermal comfort. In order to improve the thermal performance of building walls, the present work aims to construct hollow (double) walls experimentally; which are made of several air layers separated by thin aluminum sheets, and to find the extent of their impact on improving or reducing heat gain. Tests were conducted on a model room of sandwich panel with dimensions of 2 m length and 2 m width, and 2.4 m height (32.5 latitudes) in kut city, Iraq, in August. A hole was drilled in the southwest wall with the following dimensions: (1 m long, 0.3 m wide). Three models of hollow walls with a 6 cm air gap were built in this hole; one was left with a 6 cm air gap (without dividing), the second was divided into two parts by placing a thin sheet of aluminum 1 mm thick, and the third wall's air gap was divided into three parts by placing two thin sheets of aluminum. The experimental results showed that the quantity of heat gain was lowered when the air layers were increased. The heat gain decrease was 11.5 % and 21 %, respectively, when comparing the wall with a cavity of 6 cm (without splitting) with the two walls in which the air gap was divided into two and three layers.

A desiccant column contains a silica gel as a solid moisture absorbent material has been used in this study, in which the regeneration or desorption process was discussed. The dimensions of the silica-gel column are 30 cm long*30 cm wide with three thickness of desiccant bed (5,10, &15) cm, respectively. The mass flow rate and the inlet temperature of the regeneration air used are 3.72 kg/min and 53 °C respectively. This air was obtained using solar air heater in addition to an electric heating unit for temperature control purpose. The results obtained showed that the regeneration period is affected by the bed thickness. Increasing the bed thickness of silica increase the regeneration period and vice versa For example, the complete drying process of silica gel from moisture took 21 min with thickness of bed (5 cm), while it took 42 min with thickness of bed (15 cm)

In this paper, the heat transfer enhancement in a counter-flow double pipe heat exchanger with longitudinal rectangular fins on the outer surface of the inner tube was numerically investigated by ANSYS 20.R1 software using CFD package and finite volume method. Hot water flows in the inner tube at 60℃ while cold water flows in the outer tube at 25℃. The flow is laminar with five mass flow rates from 0.012kg/s to 0.02kg/s) for hot side and from 0.01kg/s to 0.03kg/s for cold side. Two types of nanoparticles Al₂O₃ and SiO₂ have been added to produce nanofluids as heat transfer fluid in the external channel (cold fluid flow) with four different concentrations from 0.04% to 1%. Results showed, as the concentration of Nanofluids increased, the heat transfer rate also increased. At 1% concentration, the maximum heat transfer coefficient was belonged to Al₂O₃/water nanofluid by 22.3% enhancement in comparison with distilled water, while the SiO₂/water nanofluid has enhancement of 19% in heat transfer coefficient in comparison with the distilled water. Both nanofluids show higher pressure drop compared with distilled water where the SiO₂/water nanofluid gives a higher drop of (33.2%), while the Al₂O₃/water nanofluid has (32.1%) of the pressure drop.

Researchers have been motivating by the global warming challenge to develop alternatives substances to compounds that contribute to this problem. The refrigerant R134a (HFC134a) has been identified as one of the most environmentally damaging gases. As a result, the refrigerant R1234yf has been employed in air conditioning systems as a substitute to the refrigerant R134a. The condensation heat transfer coefficient (HTC) of the refrigerants R1234yf and R134a was measured on smooth and standard finned tubes in this study. The finned tube is characterized by 32 Fins per inch (FPI) and 1 mm fin height. The condensation process was investigated at 37°C and 40°C condensing temperatures and 16°C to 28°C water inlet temperatures. The Nusselt theory accurately predicted the condensation HTCs on the smooth tube within mean absolute percentage deviation (MAPD) of 5.3% for R134a and 4.7% for R1234yf. As the wall sub-cooling increases, the condensation HTC decreases. With a drop in LMTD, the overall heat transfer coefficient (HTC) rises. For finned tube, the refrigerant R134a showed a greater HTC than R1234yf. In comparison to smooth tube, the enhancement ratio in HTC was 78% at 37 and 82% at 40°C for R134a. The enhancement ratio with R1234yf was 65% and 81% at 37 and 40 ° C, respectively. The experimental data was compared with predictions of two previous analytical models for film condensation on finned tubes.

Finite volume analysis of two-dimensional model has been performed to study of the influence of heat flux and mass flux on two phase heat transfer through microchannel during water flow boiling. The channel dimensions were (5×5××50) m3. The inlet boundary conditions were (1.63, 3.32, 4.9, 6.65, 8.16) . The supplied heat fluxes were 24.8 , 33.2 , 46.13 , 51 and 69 for nucleate boiling while 33.3 , 50 , 66.7 , 83.3 , and 100 for dryout condition. The inlet temperature was 30oC. It was shown that the highest heat transfer coefficient occurs at beginning of onset of nucleate boiling (ONB) after that the it will drop due the changing of the flow patterns. According to supplied heat flux, the patterns were bubble flow, dispersed bubbles, churn flow, annular flow, and then dry out condition occurs. For the mass flux 1.63kg/ the highest heat transfer coefficient was 9.5 kW/ while for the mass flux 8.16 kg/ the highest heat transfer coefficient was 20kW/ . For the mass flux 1.63kg/ the highest value of vapour quality was 0.09 while for the mass flux 8.16 kg/ the highest value was 0.15. There is a sharp pressure drop when starts to nucleate and the highest value occurs at dryout condition. This study gave an understanding of the heat exchange flow behaviour during water boiling through a single microchannel.

Aluminum-magnesium-silicon alloys are widely used in wide rage of engineering applications because they have moderate corrosion resistance, excellent formability, and high specific strength. The combined effect of quenching media and aging time on corrosion behavior, mechanical properties, and microstructure of 6061 Al alloy was investigated. Potentiodynamic polarization technique was employed to study the corrosion behavior of 6061 Al alloy in 3.5 %NaCl solution. The microstructure, phases and mechanical properties were examined via optical microscope, XRD and tensile and hardness testers respectively. The results of microstructure and X-ray diffraction analyses showed that the formation of (CuAl2) and (Mg2Si) phases improved the hardness and strength. The mechanical properties and corrosion resistance of treated 6061 Al alloy were progressively increased with increasing aging time.

An Image with high-resolution is associated with huge size data space because each information of the image is arranged into 2D picture elements' values, each of them containing its associated value of the RGB bits. The depiction of picture data makes it challenging to distribute picture files using the Internet. For Internet users, the time it takes to upload and download photos has all time been the main concern. A high-resolution image takes up more storage space, in addition to the data transit difficulty. The Analysis of Principal Component, or PCA for a brief notation, is a mathematical approach utilized to lessen the data dimensionality. It extracts the main pattern of a linear system using the factoring matrices technique. The objectives of this paper are to see how effective PCA is in reducing digital picture features and to investigate the (feature-reduced) images’ quality on comparison with different values of the variance. As per the synthesizing of the initial research, the dimension or size reduction technique through the Analysis of Principal Component typically involves of 4-important steps: (1) picture-data normalizing (2) matrix of the covariance calculating using picture-data. (3) discovering the picture-data projection (with fewer number of features) to a new basis use the Single Value Decomposition technique (SVD) (4) determining the picture-data projection (with fewer number of characteristics) to a new basis. According to testing results, the PCA approach considerably decreases the size of picture data while sustaining the original picture’s fundamental properties. This approach reduced file size by 35.3 percent for the best feature lowered quality. The upload time of picture files through the Internet has substantially improved, particularly for mobile device downloads.