Maha Al-Ali
Abstract
The Kinetics study of drug release is an essential requirement to examine the capability of the drug formulation to modulate with the typical drug release profile. In the present work, hence, Weibull model and other traditional drug release models are selected to investigate the release of tablets prepared ...
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The Kinetics study of drug release is an essential requirement to examine the capability of the drug formulation to modulate with the typical drug release profile. In the present work, hence, Weibull model and other traditional drug release models are selected to investigate the release of tablets prepared using different drying techniques in a simulated abdominal solution. These tablets are prepared using electromagnetic microwave irradiation tablet (MVT), convective drying (CVT), freeze drying (FRT), vacuum drying (VAT), and that without drying process (NDT). This study aims to compare the Weibull models with other conventional drug release models in inspecting the kinetics of the drug release of all tablets. These models are the Zero-Order, Higuchi, First-Order, Hixson-Crowell, and Korsmeyer-Peppas. This work delves into the best kinetic model that defined the tablets' release mechanisms including the new multi-component tablets (MVT), to ensure their releases are on appropriate behavior. The results show that the Weibull model is the best model to present the release profile of all tablets except for MVT and VAT tablets, while Higuchi gets the optimal model. Among the conventional models, Higuchi, Korsmeyer-Peppas, and Hixon-Crowell are the best conventional models that fit all types of tablets. Based on the Weibull model factor, non-Fickian diffusion is the dominant release mechanism for NDT and VAT. Though Fick diffusion controls the drug release mechanism of FTR, CVT, and MVT tablets. Additionally, three modified models were created and found to be more convenient to denote the release of the formulated tablets with very high accuracy.
Ying Chi Tan; Muhammad Hafeez bin Abdul Nasir; Ahmad Sanusi Hassan; Jestin Nordin; Yasser Arab; Mohammad Dolok Lubis
Abstract
The design of educational building has become increasingly important concurrently due to the needs interactive and engaging spaces for improved students’ academic performance. Conventional design of educational spaces invariably lack design aspects that facilitate engagement. Therefore, it has ...
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The design of educational building has become increasingly important concurrently due to the needs interactive and engaging spaces for improved students’ academic performance. Conventional design of educational spaces invariably lack design aspects that facilitate engagement. Therefore, it has become the aim of this research to evaluate the spatial configuration a veterinary institute, based on the space syntax analysis from the spectrum of the level of wayfinding and permeability. The case study of this research is Cornell University College of Veterinary Medicine an institutional building that is a globally renowned in the veterinary industry. Being at the forefront of research into animal well-being and the prevention of infectious diseases, the building's design emphasises providing cutting-edge educational spaces and fostering innovative curricula for educating future practitioners and researchers while also extending vital support to communities worldwide. The study uses the justified graph and visual graph analysis (VGA) based on DepthMapX software to identify the level of permeability and wayfinding of the designed spaces. The analysis demonstrates that a majority of the areas covered in the case study building have moderate integration levels and between high and moderate connectivity levels. Highly integrated and connected spaces are important in spatial design of educational institutions in providing allowing for cross-disciplinary collaboration and outstanding students’ engagement. In essence, the outcome of the study demonstrates the selected building typology case study building has a well-designed spatial configuration that emphasises the building’s main users.
Abdul Raheem Kadhim Abid Ali; Haydar Al-Ethari; Ali Abbas Hasan
Abstract
The performance of functionally graded materials is much better than materials with unchanged properties and compositions. Al-Cr-Fe alloys with different Cr concentrations were proposed for this work. Potential applications for these materials include automotive pistons. FGM was fabricated by a successive ...
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The performance of functionally graded materials is much better than materials with unchanged properties and compositions. Al-Cr-Fe alloys with different Cr concentrations were proposed for this work. Potential applications for these materials include automotive pistons. FGM was fabricated by a successive stage of the sequential casting method with mechanical vibration during the solidification. The FGM sample consists of two alloys with different chemical compositions (Al-8Si-2Fe) and (Al-2Cr-2Fe). Two types of samples were studied and compared, with and without mold vibration. The method of mechanical mold vibration, which in turn reduces the segregation and pores in the cast and refines the microstructure. The results of the XRD showed the presence of α-Al phase, Al₈₀Cr₁₃.₅Fe₆.₅, Al₁₃Cr₂, and Al₁₃Fe₄ compounds that enhance the strength of the alloy. Optical microscope images showed a difference in the microstructure at both sides of the interface between the two alloys. There is variation in the hardness values due to the difference in the chemical composition of the alloys. The recorded improvement in the tensile strength was 17%, and a decrease in Compression by 1.5%.
Raghad Abdullah Ahmed; khawola F. Mahmoud; kossay K. Alahmady; Randa Hassan Mohamed
Abstract
The world is facing significant climate challenges that demand immediate action. Sustainable practices in architecture are essential for addressing these challenges by enhancing energy efficiency, reducing carbon emissions, and promoting environmental resilience. Green education has gained considerable ...
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The world is facing significant climate challenges that demand immediate action. Sustainable practices in architecture are essential for addressing these challenges by enhancing energy efficiency, reducing carbon emissions, and promoting environmental resilience. Green education has gained considerable attention as a means of embedding sustainability principles into architectural practices. This research identifies a critical gap in existing literature regarding the clear definition of characteristics, principles, and frameworks for green education in architecture. Through the analysis of existing curricula and prior research, this study pinpoints key trends in green education that support sustainable architectural practices. The findings reveal a variety of green education approaches, incorporating diverse tools and practical strategies essential for preparing students to effectively adopt and implement sustainable practices across different levels of architectural development. The study concluded that integrating green education into architectural curricula is essential for promoting a sustainable future. By providing students with the tools, knowledge, and values required to address complex environmental challenges, architectural education can play a key role in shaping a resilient, energy-efficient, and environmentally responsible built environment. Future research should continue to explore and refine these educational strategies, ensuring they evolve alongside the shifting demands of sustainability in architecture.
Kawa Abdulghany Abdullah; Ramzi Raphael Ibraheem Barwari
Abstract
Variable Refrigerant Flow (VRF) systems are extensively employed for space heating and cooling, particularly in multi-story buildings where outdoor units are discreetly placed behind aluminum louvers for architectural considerations. However, these metal louvers can hinder ventilation and heat rejection ...
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Variable Refrigerant Flow (VRF) systems are extensively employed for space heating and cooling, particularly in multi-story buildings where outdoor units are discreetly placed behind aluminum louvers for architectural considerations. However, these metal louvers can hinder ventilation and heat rejection of the VRF air-conditioning outdoor unit, adversely affecting system performance. This impact manifests in elevated suction temperatures, increased energy consumption, and a diminished coefficient of system performance due to hot air recirculation behind the louvers. Additionally, the expelled hot discharge air from outdoor units rises, increasing the suction air temperature for the upper floors' VRF system. This numerical analysis study investigates the impact of louver tilt angle and opening ratio factors on the thermal performance of VRF air conditioners when installed on building balconies. The objective is to optimize louver designs for concealing condensing units, thereby enhancing overall performance and minimizing power consumption. Two proposed louver designs, incorporating varying tilt angles and opening ratios, are presented as solutions and compared with the existing design. The optimal solution to alleviate the unintended "stuck and stack effects" in the current design involves a proposed modification. The first option suggests decreasing the louver's tilt angle to 20° while maintaining a 60% opening ratio to lower suction temperatures and improve thermal performance. Additionally, increasing the louver opening ratio to 80% effectively reduces air recirculation, providing an alternative solution to optimize the overall performance of the VRF system. Comparisons with previous studies underscore local climate variations and operational disparities, emphasizing the need for tailored louver designs specific to environmental conditions.
Rwaa Talal Abdullah; Omar D Jumaah; Yogesh Jaluria
Abstract
Metal plates with different cutout shapes are commonly used in various engineering applications. Cutouts are unavoidable in structural design as they are needed for practical reasons, such as reducing the structure’s weight and providing access to other parts. This paper investigates the stress ...
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Metal plates with different cutout shapes are commonly used in various engineering applications. Cutouts are unavoidable in structural design as they are needed for practical reasons, such as reducing the structure’s weight and providing access to other parts. This paper investigates the stress concentration induced in Al-2024 T3 plate with an elliptical cutout under a tensile load, experimentally and numerically. Practical tensile test and strain gauge results measure the generated stress concentration in Al-2024 T3 plate. A finite element model is created to analyze the stress concentration factor (SCF) in Al 2024 T3 plate under uniaxial loading. The numerical model is validated against the experimental and analytical results. The influence of the elliptical cutout orientation angle (φ) on SCF was investigated. The results showed that SCF increases with increasing elliptical cutout orientation angle (φ = 0°) to (φ = 90°). However, adding auxiliary holes around the central elliptical cutout enhances the stress distribution and reduces SCF in the range (1.9 to 25 %). Surrogated-based optimization is used to build response surface models for predicting optimal SCF and removal mass (RM). Multi-objective optimization is formulated to minimize SCF and maximize RM. The results show that increasing AH diameter leads to minimizing SCF and maximizing RM for the plate with an elliptical cutout that is restrained to be greater than or equal to 45 (φ ≥ 45°). Pareto frontier offers reliable, optimal solutions of SCF and RM based on input design parameters, including the orientation angle and auxiliary hole diameters.
Batool Rafid Natiq; Lwaa Faisal Abdulameer
Abstract
The intelligent reflecting surfaces (IRSs) that support non-orthogonal multiple access (NOMA), and using beamforming techniques in free space optical (FSO), are systematically reviewed in this study. The IRS improves the spectral efficiency and connection by guiding channel users more efficiently through ...
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The intelligent reflecting surfaces (IRSs) that support non-orthogonal multiple access (NOMA), and using beamforming techniques in free space optical (FSO), are systematically reviewed in this study. The IRS improves the spectral efficiency and connection by guiding channel users more efficiently through reconfigurable reflecting elements. This enhancement makes it easier to apply NOMA even when the original channels are not aligned. The study emphasizes how hardware limitations like phase shifters with poor precision affect performance. A thorough analysis of previous studies on IRS varieties, beamforming strategies, and multiple access strategies is given. Additionally, the research gaps and potential future paths are also detailed. Background information on IRS types is one of the key contributions. Another major contribution is highlighting the advantages of combining IRS with beamforming and multiple access strategies in FSO communication systems.
Laith Louay; Shaker Bahar
Abstract
Water pollution and scarcity are problems of the current time due to the industrial and biological wastes that are thrown into the aquatic environment, especially the water produced from petroleum refineries, because it contains organic and inorganic pollutants. In this study, work was done to reduce ...
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Water pollution and scarcity are problems of the current time due to the industrial and biological wastes that are thrown into the aquatic environment, especially the water produced from petroleum refineries, because it contains organic and inorganic pollutants. In this study, work was done to reduce the chemical oxygen demand (COD), which represents some major pollutants such as organic materials in real wastewater collected from the Najaf refinery in Iraq, using successive electrocoagulation (EC) and electrooxidation (EO) processes. Graphite and aluminum (Al) electrodes were used as the anode, and a stainless-steel electrode (SS) as the cathode. The Box-Behnken design (BBD) of experiments was used. Starting from COD (1250 ppm), the effect of current density, time, NaCl concentration, and pH on the removal efficiency was studied. The results indicate that the removal efficiency is directly proportional to the increase in current density, time, and NaCl conc, whereas it is inversely proportional to the increase in pH, as the optimal conditions for removal were at current density, time, NaCl concentration, and pH in this case. Conditions: About 97.5% COD removal was achieved. Through the results of the ANOVA analysis, it was found that current density and time have a high effect on removal, while NaCl concentration and pH have a lower effect on removal.
Suha Anwer Ibrahim; Salem Alhamd; Shahad Mudhafar Ali; Mohammed Nsaif Abbas; Thekra Atta Ibrahim; Alanood A. Alsarayreh
Abstract
Benzidine, a Class A carcinogen, poses a significant threat in textile industry wastewater as it is a key intermediate in dye production. The promising adsorption technology using agricultural waste has proven to be an effective solution for water pollution. This study explores the potential of pineapple ...
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Benzidine, a Class A carcinogen, poses a significant threat in textile industry wastewater as it is a key intermediate in dye production. The promising adsorption technology using agricultural waste has proven to be an effective solution for water pollution. This study explores the potential of pineapple peels (the agricultural wastes of little interest) as a low-cost adsorbent. Pineapple peels, typically discarded in massive quantities annually, exhibited a remarkable 91.064% maximum adsorption efficiency in a batch-type unit. This result was achieved at a pH, agitation speed, initial concentration, adsorbent dose, contact time, temperature, and particle size of 1, 450 rpm, 8 ppm, 3 g, 150 min, 20 °C and 88 µm, respectively. Morphological studies elucidated a surface area of 48.627 m²/g, retaining 11.25% post-treatment. Fourier-transform infrared (FTIR) tests highlighted various functional groups on the peel’s surface, undergoing alterations upon contact with benzidine. Scanning electron microscopy (SEM) examinations confirmed structural modifications post-adsorption. The adsorption process demonstrated spontaneity, low entropy, and exothermic behavior. Kinetic modeling revealed that the intra-particle diffusion model best represented the adsorption data. The isothermal behavior of adsorption was aptly described by the Langmuir model. The pineapple peels waste were tested to be a cheap rodenticide for laboratory rats as a benefit manner to dispose these toxic residues. The results show that very good ability to eliminate the rodent with half lethal dose identical with that recorded in literature. Thus, the study offers an economically viable and eco-friendly approach, aligning with the ethos of achieving zero-residue levels in waste management.
Sura M. A. Al-Hayali; Asmaa H. T. Al-Dabbagh
Abstract
Dominance in architecture is defined as the superiority and predominance of an element or group of elements over the rest in the composition, which causes its attractiveness to the recipient/viewer. The dominant elements often include the basic idea of the architectural work and carry a set of design ...
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Dominance in architecture is defined as the superiority and predominance of an element or group of elements over the rest in the composition, which causes its attractiveness to the recipient/viewer. The dominant elements often include the basic idea of the architectural work and carry a set of design characteristics. The research assumes that there is a fundamental causal relationship between the monumentality of the buildings and the presence of the design characteristics that causes dominance. Thus, the aim was to verify the presence of these characteristics in the projects of the architect (Louis khan), and to find out the reasons of dominance that most obvious and which were the reasons of the monumentality of his works. The research adopted a descriptive approach by using a questionnaire for architects. The results showed the presence of dominance on both total and partial levels of design in his projects due to the types of basic shapes, because of their constant presence in the mind and their large size. At the spatial level, the dominance caused by the complete repetition of the elements and their important functions.
Fadhil Toufick Aula
Abstract
Electric storage systems like solar systems and electric vehicles use batteries for storing electricity due to their simplicity, efficiency, considerably small size, and dispatchability. These batteries operate on the principle of charging/discharging and require equalization for voltage balance, especially ...
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Electric storage systems like solar systems and electric vehicles use batteries for storing electricity due to their simplicity, efficiency, considerably small size, and dispatchability. These batteries operate on the principle of charging/discharging and require equalization for voltage balance, especially in series-connected batteries. In this research, a novel technique is presented for enhancing batteries’ voltage equalization, which is based on the variable duty cycle, D, of pulse width modulation (PWM) in the dynamic capacitor technique. This method controls two energy storage elements: an inductor and a dynamic capacitor via variable D of PWM. The presented technique was implemented on lead-acid batteries connected in series using MATLAB/Simulink. The simulation results showed that increasing D to 80% can reduce the equalizing process time from 500 seconds to just 125 seconds, with voltage differences decreasing from 800mV to just 2.2mV, equalized by 99.98%. For comparison, a well-known fixed switched-capacitor technique was used, and results showed that variation of D had no effect even after 500 seconds of the equalizing process, and the batteries’ terminal difference voltages still were above 220mV (less than 72% equalizing). Thus, the presented technique demonstrates superior performance, highlighting the significant contribution of variable duty cycle PWM in balancing batteries’ terminal voltages.
Koltouch Anantakarn; Rerkchai Fooprateepsiri; Bhattharadej Witchayangkoon; Kritsada Anantakarn; Boonruk Vanborsel
Abstract
This study examines the accuracy performance of GNSS receivers when connected to the continuous reference station (CORS) network managed by Thailand's Department of Lands (DOL) and the Royal Thai Survey Department (RTSD), focusing on the impact of inserting SIM cards between the receiver and controller. ...
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This study examines the accuracy performance of GNSS receivers when connected to the continuous reference station (CORS) network managed by Thailand's Department of Lands (DOL) and the Royal Thai Survey Department (RTSD), focusing on the impact of inserting SIM cards between the receiver and controller. Three GNSS receivers were tested: two from the same brand but different models, and one from a different brand. The research investigates how the CORS network's effectiveness and the method of SIM card insertion influence the data accuracy and receiver stability. The results show that data stability improves when connected to the RTSD's CORS network, with more consistent and reliable performance observed when SIM cards are inserted directly into the receiver. In contrast, inserting the SIM card into the controller led to significant instability in the GNSS data. These findings highlight the importance of both network choice and proper SIM card placement for optimal GNSS performance.
Murtadha A. Hanoon; Mohsen H. Fagr; Kamaal S. Mekki
Abstract
In this numerical investigation, the effectiveness of utilizing advanced helical coiled wires (HCWs) as tube inserts for the purpose of heat transfer and turbulence enhancement under turbulent flow conditions (Reynolds numbers: 3000-11000) was examined. HCW followed a helical guide path instead of a ...
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In this numerical investigation, the effectiveness of utilizing advanced helical coiled wires (HCWs) as tube inserts for the purpose of heat transfer and turbulence enhancement under turbulent flow conditions (Reynolds numbers: 3000-11000) was examined. HCW followed a helical guide path instead of a straight one in a typical coiled wire case, resulting in increased flow complexity. Circular and equilateral triangular wires, maintaining equal cross-sectional areas, were tested, with pitch ratios (P/D) being 1, 1.5, and 2. Simulation was performed using ANSYS Fluent 22, the working fluid considered throughout the study was air. Results indicated increased Nusselt number (Nu) and friction factor (f) compared to a plain tube. The thermal performance factor was found to have an inverse relationship with both pitch ratio and Reynolds number severally. The study reported that the circular insert at (P/D) = 1 and Re = 3000 exhibited the maximum thermal performance factor of 1.379, while the highest enhancement ratio for the Nusselt number of 4.14 was recorded in the case of the triangular insert at the same Reynolds number. Additionally, the maximum friction factor increase occurred with the triangular model at Re = 11000, reaching a friction factor ratio of 40.4.
Gaidaa Shaker Kareem; Essam Lauibi Esmail
Abstract
Electric vehicles (EVs) are known for their power efficiency and lower pollution levels compared to traditional vehicles. The design of dual-motor EV systems, utilizing planetary gear trains, is a significant area of research. The impact of power circulation on losses in novel and patented planetary ...
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Electric vehicles (EVs) are known for their power efficiency and lower pollution levels compared to traditional vehicles. The design of dual-motor EV systems, utilizing planetary gear trains, is a significant area of research. The impact of power circulation on losses in novel and patented planetary gear mechanisms has not been extensively explored in previous configuration design studies, despite its importance as a key component of the mechanism. Accurately understanding the power distribution in a dual-motor system seems to be crucial for fully comprehending an invention. This paper explores the positive aspects and drawbacks of PGT configuration, with a focus on efficiency, which may affect competitiveness in real-world applications. If power flow estimation is not possible or if operating constraints prevent it, it is likely that the patent was not thoroughly examined or the inventor lacked experience in the subject matter. A nomograph is a graphical tool used to analyze the relationships between variables in power-split systems, including power flow and efficiency. A systematic approach is proposed for evaluating the performance and power loss of PGTs. Analytical formulas for powers, losses, and efficiency are derived. A parametric study on a wheel hub motor reveals that a higher gear ratio enhances efficiency and performance, with power flow analysis indicating power circulation and amplification. Controlling gear ratios precisely can change power flow direction, enhancing efficiency. Criteria for no power circulation are established, leading to a new configuration.
Nivedika Kher; Kamaldeep Boora; Krishna Yadav; Vikram Kumar
Abstract
The rising demand for renewable energy sources, particularly solar power, has surged in recent years as a sustainable solution to global energy challenges. Solar power inverters show a crucial part in transforming solar-generated direct current (DC) into usable alternating current (AC), which is required ...
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The rising demand for renewable energy sources, particularly solar power, has surged in recent years as a sustainable solution to global energy challenges. Solar power inverters show a crucial part in transforming solar-generated direct current (DC) into usable alternating current (AC), which is required for a number of applications across residential, commercial, and industrial sectors. This paper provides a concise overview of key aspects related to solar power inverters, highlighting their importance in the solar energy ecosystem. Specifically, this paper focuses on the design of Solar Inverter, which is needed to run AC loads and is primarily utilized for consumable purposes. Moreover, it delves into the principles and functioning of two widely-used inverter topologies: Push-Pull and H-Bridge. To validate the system, the circuit model is implemented on hardware, confirming its practicality. The developed inverter has a 100W power output, a 12V input voltage, and a 220V output with a 50Hz square wave output.
