DIYALA JOURNAL OF ENGINEERING SCIENCES

This paper describes several maximum power point tracking algorithms for partial shading conditions that have detrimental effects on photovoltaic systems. The method used wasa literature review of articles from reputable publishers.Fifty-twoarticles were obtained after meeting the established criteria for selection. The literature review focused on the ability of the maximum power point tracking algorithmsto overcome partial shading conditions in terms of tracking speed, tracking accuracy, efficiency and implementation complexity. Some algorithms wererecommended to be applied for maximum power point tracking,including the single swam algorithm and the perturb and observealgorithm, the enhanced adaptive step size perturb and observe algorithm, the novel adaptable step incremental conductance algorithm, the improved bat algorithm and fuzzy logic controller algorithm and the particle swarm optimisation with one cycle control algorithm. In terms of implementation complexity, these five algorithms are categorised asmedium-complexity algorithms, which can be characterised bylow cost, high efficiency and even 100% high tracking speed and accuracy with a minimum number of sensors used.

A conventional vapor compression refrigeration cycle is among the most effective technology in refrigeration systems. In the present experimental study, thermal performance and the effect of the condenser temperature have been analyzed. With the decrease in the condenser temperature, the overall performance of the refrigeration cycle is increased. However, the cooling power and efficiency of conventional vapor pressure air conditioning units can experience a significant reduction when operating in extreme weather (hot and dry). This drop is mainly affected by the increase in the temperature (and pressure) of the condenser with an increase in the ambient air temperature. Unfortunately, Iraq experiences the most extreme summer seasons especially in the months of June and July when the temperature reaches or exceeds 50° C. So, ground cooling has been used in areas with a hot environment for split system air conditioners. Evaporative cooling was also performed to lower the coolant temperature of the AC unit used inside the condenser area. Experimental results showed that when using a geothermal heat exchanger, the temperature of the condenser is reduced from 116 to 110 ° C and the coefficient of performance (COP) is improved by 41%. In addition to this when the system uses evaporative cooling the temperature of the condenser is reduced from 110 ° C to 88° C. Moreover, a 65% improvement was made in the COP of the conventional vapor compression refrigeration cycle. Furthermore, with a decrease in the evaporator temperature from 6 to 3.5 °C there was an increase in refrigeration capacity by an average of 52%.

Silver-hydroxyapatite (Ag-HA) nanocomposite coating on stainless steel (316L) sheets was prepared by electroless deposition. Several studies have analysed the influence of bath composition on the corrosion behaviour of Ag-HA bio-nanocomposite coating produced by electroless deposition. Therefore, the present study compared the influence of varying concentrations of HA nanoparticles (0.1, 0.3, and 0.5) g/L on the mechanical (microhardness) and chemical (corrosion resistance and ion release) properties of the Ag-HA nanocomposite coating. The Ag-HA nanocomposite coating exhibited a remarkable increase in microhardness from 104.7 Hv to 139.9 Hv at 0.5 g/L HA nanoparticles and improved corrosion resistance, where the corrosion rate was enhanced for the coating from 5.954×10-1 mpy to 2.633×10-2 mpy in the presence of nano-HA. The ion release analysis of the element coating revealed that the nickel content was within the permissible limit in accordance with the amount of Ni permitted to exist inside the human body, and chromium was not found.

This paper presented an experimental study of external rehabilitation of damaged Reinforced Concrete (RC) Beams with Carbon Fibre Reinforced Polymer (CFRP) sheets. The primary objective is to study the shear behavior of four simply supported beam specimens with an total length of 1700mm, a width of 150 mm, and a depth of 250 mm was tested under a monotonic two-point load. The variable used in this study was the specimen damage ratio (50%, 60%, and 70%), while the layout of CFRP sheets and shear-span to effective depth ratio (a/d = 2.5) were kept constant. The design of the examined beams was according to ACI 318M-19 to ensure shear failure. From this study, it was concluded that external rehabilitation with U-shape CFRP sheets offered a very adequate and efficient rehabilitation method for damaged RC beams. Each beam's behavior was examined concerning the crack pattern, first crack load, load-deflection and ultimate load. The CFRP rehabilitation has improved the ultimate load capacity of damaged beams by about 10.91% to 15.96% compared with the expected remaining ultimate load capacity of control specimens without rehabilitation, as well as an increment in the deflection of mid-span from -6.81%, 24.11% at an ultimate load.

Over the past decades, pile foundations used to support buildings through a transfer of superstructure loads into more stable soil strata than surface soil layers. Buildings are exposed to seismic force, pile undergoes more stress through the significant vibration of the surrounding soil in addition to the static stresses of buildings. The investigation of the behavior of pile foundations under the influence of earthquakes is still limited or not well described. Further, this paper presents a theoretical study to evaluate the vertical settlement and horizontal displacement of piles embedded in clay and silty soil of Baqubah soil under the effect of the acceleration time history of the 1940 El-Centro earthquake. The study was carried out by using the commercial finite element software PLAXIS 3D. A three-dimensional analysis of the soil-pile foundation for four multi-story buildings is performed with different diameters (0.5, 0.7, and 1) m for the corner, exterior, and interior pile, respectively. The linear elastic model for pile foundation and the Mohr-Coulomb model for soil layers were used in this numerical analysis. The research showed that vertical settlement and horizontal displacement increase as the duration of the earthquake increases, and horizontal displacement with values smaller than vertical displacement. Also, the results showed the vertical settlement is similar for different diameters, in contrast to the horizontal displacement, which was of different values with a range between (3% to 22%) when the diameter increased from 0.5m, 0.7m, and 1m. Also, it can be observed that values increased with the direction of the earthquake from the right to the left side of the pile-soil system with a range of (12% to 32%).

The increase in energy consumption, along with an increase in human population and industrial activities after the industrial revolution, has caused to increase in the consumption of fossil fuels. Carbon dioxide from fossil fuels has the most significant effect on the production of greenhouse gases and global warming. The absorption of CO2 emitted into the atmosphere is the most crucial method to reduce carbon dioxide in the air. Recently, a new solvent has been developed to absorb greenhouse gases under the name of deep eutectic solvents (DES). These solvents are biodegradable, non-toxic, or low-toxic compounds that are easily obtained. A mathematical model based on the Peng–Robinson (PR) equation of state (EOS) with three different mixing rules Modified van der Waal's (M1), Quadratic (M2) and Wong Sandler (M3) was developed to correlate the CO2 solubility in six types of DESs. The model was validated and compare with the obtained experimental data reported in the literature at temperatures (293.15 – 333.15) K and pressure (0.405 – 30.408) bar. The experimental and calculated data of PR EOS with three mixing rules were generally in a good agreement by obtaining % AARD a round (0.08 – 8.08), (0.05 – 7.58) and (0.09 – 6.56) for M1, M2 and M3 respectively, and the best results with less %AARD was obtained from Wong-Sandler mixing rule in the most of cases.

A cloud computing environment provides a cost-effective approach for end-users to remotely store and retrieve private data through an internet connection anytime and anywhere. The security of these data cannot always be guaranteed because they can only be accessed by the end-user through a third-party interface, making them vulnerable to potential breaches of authentication and data integrity. This paper presents a secure hybrid approach for a medical image stored in the cloud that prioritises data security and integrity. The suggested model uses a combination of elliptic curve cryptography and advanced encryption standard algorithms to ensure authentication and data integrity. Results demonstrate the superior performance of the proposed model to existing methods, aligning it with compliance requirements for handling sensitive data stored in the cloud. This approach includes adherence to regulations, such as the Health Insurance Portability and Accountability Act (HIPAA) and General Data Protection Regulation (GDPR), which prescribe specific guidelines for the secure handling, storage and processing of personal information. Contrary to traditional and other hybrid systems, this study suggests that this approach is one of the best in guaranteeing the security of medical images in the cloud.

Carbon Fiber Reinforced Plastic (CFRP) is widely employed today, mainly in industries, due to its required properties of high corrosion resistance, high strength, and lightweight, this work studies the influence of the cutting parameters on the surface roughness by drilling two types of carbon-fiber-reinforced polymer composite material (CFRP) Composites 0° angle and 90° angle, the investigated of the drilling of CFRP by using an experimental design based on the Taguchi L18 orthogonal array. Spindle speed, feed rate, and tool diameter were the input parameters, and surface roughness was the output. The cutting settings (410, 806, and 1003) rpm and two different HSS tools were employed in the drilling operation of the CFRP composite. The feed rates used were (0.1, 0.2, and 0.3) mm/rev (at 10 and 12 mm in diameter). The Taguchi approach, the cutting speed, feed rate, and tool diameter were optimized to be 1003 rpm spindle speed, 0.1 mm/rev feed rate, and 10 mm, respectively, at a 0° angle, the surface roughness was 2.74 µm, while at a 90° angle, 4.12 µm, surface roughness was created by the Taguchi optimization of the surface for the cutting variables. According to the ANOVA analysis of the surface roughness (Ra) for CFRP/0-angles, The P-value of the factor feed rate was 0.044 less than 0.05, while the p-values of the tool diameter and spindle speed were greater than 0.05. At the CFRP/90-angle, the p-values of the factors feed rate and spindle speed were both less than 0.05, while the p-value of the tool diameter was 0.208.

Artistic and cultural buildings play a vital role in protecting national and cultural identity. Therefore, the necessity of adopting modern technologies when constructing and maintaining such buildings has become a necessity, especially with the continued growth of the construction industry and a move towards sustainable construction. Building Information Modelling (BIM) is a technology used to simplify and improve business performance in the construction industry while saving time and money. This paper aims to find the justifications for conducting research on the importance of using BIM to promote a sustainable economy in Iraqi artistic and cultural projects. This paper was conducted through literature reviews and field surveys of experts in such buildings. The results showed that there is a weak government effort to implement BIM and the owner does not request the use of BIM in the design and implementation of projects. In addition, BIM can also contribute to the efficient use of natural and industrial resources while reducing attrition and waste and improving energy efficiency by reducing energy consumption and using renewable energy. Accordingly, the researcher recommended the importance of conducting research on the importance of using BIM when creating artistic and cultural projects, in addition to the necessity of educating future generations about the concepts of sustainability and sustainable economy on a larger scale and the necessity of using biotechnology that preserves the environment and natural resources, as well as the necessity of educating the concerned authorities on how to do that.

This research aims to remove the moisture (latent load) generated by the occupants of the space due to the addition of water vapor resulting from the natural breathing process, the perspiration that evaporates in the air of the space. In sum, the dehumidification system (DS) reduces the amount of latent load or removes it completely to reduce the load on the air conditioner. In this study, adsorbent materials, such as silica gel-Blue and sawdust were used and their effectiveness was compared when used in dehumidification. The results of these experiments for June showed that the adsorption rate and temperature of the blue silica gel - Blue were 20% and 34°C, while the humidity and temperature increased to 52% and 36°C when using sawdust (when rotating the dehumidifying system hourly). Moreover, for July, the adsorption percentages of silica gel-Blue were 8%, while the moisture content of sawdust increased to 49%, while the adsorption percentage in August when using silica gel - Blue was 10% and the relative humidity increased until it reached 39% when using sawdust. While the temperatures in July and August reached their maximum value when using silica gel - Blue and sawdust at 35°C and 36°C, respectively. The water vapor absorption rate in June, July, and August is 83.39 g, 70.82 g, and 65 g, respectively. While the drying process increased during these months due to the increase in solar radiation. Therefore, silica gel - Blue has proven its effectiveness by absorbing moisture more efficiently than sawdust. However, when drying sawdust, it was more effective and faster drying than silica gel - Blue.

An alternative reinforcing shear technique was proposed during this work in place of the traditional vertical stirrups. Three reinforced concrete beams with dimensions of (200 * 300) mm and a length of 1800 mm were used. A reference control beam with traditional vertical stirrups (RCWS) and two beams reinforced with flamingo with a fixed angle of 45° and free ends (50% and 50%) from effective depth were used, while the main variable was the bonding process with concrete using a screw head (FWS) and hook (FWH). In the flamingo technique, the hook was used and the screw head was used at an equal angle of 130 degrees. A significant improvement was found in the shear capacity of the beam compared to the reference sample. Also, using a screw head made the shear capacity 13.22% higher than using a hook and improved the shear ductility, final deflection, and crushing behavior of beams made with the flamingo technique.

This article presents a performance comparison of two known public key cryptography techniques namely RSA (Rivest–Shamir–Adleman) and El-Gamal algorithms to encrypt/decrypt the speech signals during transferring over open networks. Specifically, this work is divided into two stages. The first stage is enciphering-deciphering the input speech file by employing the RSA method. The second stage is enciphering-deciphering the same input speech file by employing the El-Gamal method. Then, a comparative analysis is performed to test the performance of both cryptosystems using diverse experimental and statistical analyses for the ciphering and deciphering procedures like some known speech quality measures: histogram, spectrogram, correlation, differential, speed performance and noise effect analyses. The analyses outcomes reveal that the RSA and El-Gamal approaches are efficient and adequate for providing high degree of security, confidentiality and reliability. Additionally, the outcomes indicate that the RSA speech cryptosystem outperforms its counterpart the El-Gamal speech cryptosystem in most of ciphering/deciphering speech performance metrics.