Metallurgical and Materials Engineering (E-Journal)
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Unraveling a Nonlinear Coronavirus Model: An Evolutionary Approach to Dynamic Analysis
Get PDFThe COVID-19 epidemic has underlined the vital need of thorough mathematical models to project disease trends and evaluate intervention strategies. Combining vaccination rates (v) and transmission characteristics (\u03b2), this study develops an improved SEIR (Susceptible-Exposed-Infected-Recovered) epidemic model to investigate the spread of COVID-19. By means of stability analysis, we find disease-free and endemic equilibrium points showing that more vaccination coverage significantly reduces the fundamental reproduction number (R₀), hence stabilizing the system. Using the Runge-Kutta method and a novel Evolutionary Padé-Approximation (EPA) approach, which combines Padé rational functions with Differential Evolution optimization to preserve accuracy while following model constraints (positivity, boundedness, and feasibility), numerical solutions are obtained. Even under high transmission conditions (β = 14), simulations show that improved vaccination speeds the decline of susceptible and infected populations while increasing recoveries, hence lowering R₀ below 1 at 50-100% vaccination rates. Comparative studies of the Runge-Kutta and EPA techniques show notable agreement, hence confirming EPA as a viable substitute for large-scale epidemiological modeling. Our results highlight the vital need of immunization in controlling COVID-19 and provide a computational tool for legislators to strengthen containment initiatives
Real-Time Induction Motor Condition Monitoring Using Machine Learning Approaches
Get PDFInduction motors are widely used in the industrial field thanks to their reliability and robustness, so understanding their health state is essential to prevent costly failures. Condition monitoring techniques measure parameter deviations from the normal performance. When these deviations reach dangerous levels, a warning can be issued and a maintenance task scheduled. Although several types of sensors can be used, a combination of vibration, thermal, and electrical signals is preferred. Condition monitoring has also been approached using machine learning techniques. Nevertheless, the deployment of effective techniques in a real-time setup is still a challenge. A real-time end-to-end system is proposed, integrating the acquisition of the sensor signals, their processing, and the application of different machine learning techniques.
Condition monitoring aims to collect sensor signals continuously, detect deviations from the normal behavior of the system, and issue warnings. Considering that accidents, for instance, due to bearing failure, are rare, the monitoring techniques also need to be reliable; thus, performance in terms of sensitivity and specific are key. Commonly, information from different types of sensors is combined so that a drastic event in one sensor can be compensated by the others. The three most common sensors used for induction motor condition monitoring are vibration, thermal, and electrical. Vibration information has been widely used due to its high sensitivity to faults, such as bearing wear, misalignment, and imbalance. Electrical monitoring is also a promising approach since a fault in the motor will generate changes in the electrical parameters because the electrical signals are the input and output of the system. The thermal behavior of the induction motor is also an important aspect to monitor
Effect Of Milling Frequency On The Structural And Dielectric Properties Of Tetragonal Srtio3 Nanoceramics
Get PDFIn this research work, we qualitatively study the structural and dielectric properties of tetragonal SrTiO3 nanoceramics. The ferroelectric material with perovskite structure has various applications in different fields such as electronics and energy storage devices. Strontium titanate (SrTiO3) among all ferroelectric materials has attractive attention due to its numerous applications as tunable microwave capacitor, thermistors, varistors sensors and microwave filters. Strontium titanate (SrTiO3) nano-ceramics powders are prepared by solid state reaction route. Nano powders of strontium titanate are prepared by high energy planetary milling technique. The samples are prepared at various milling frequency of 15Hz- 50Hz for 4 h of milling time and then calcined at 1200 C for 60hrs. The calcined powders are characterized by XRD and Impedance analyzer. XRD studies reveal the p-cubic structure when the samples are milled at 15Hz to 35Hz of milling frequency and belong to space group of Pm3m. The phase transition from p-cubic to p-tetragonal was observed for the sample milled at 40Hz of milling frequency. After 40Hz of milling frequency no phase transitions in crystal structure of strontium titanate was observed. Only strengthening and phase stability of perovskite tetragonal SrTiO3 was observed with increasing milling frequency. Dielectric and impedance analysis have been examined by impedance analyzer with a frequency range of 20Hz to 20MHz.Room temperature dielectric properties show immense dielectric constant value of ~ 73183.3 at 50Hz of milling frequency. The tangent loss is minimum for this sample. Colossal dielectric constant in nano-ceramics SrTiO3 has impending applications such as in microelectronic devices as well as for the advancement of innovative capacitive data storage devices
Cost, Tariffs, And Electricity Pricing In Iran: A Comparative Study
Get PDFIn recent years, the design and implementation of electricity tariff mechanisms have become crucial for ensuring a sustainable supply, promoting consumption efficiency, and advancing social justice, serving as key tools in energy policy. In both developed and developing countries, industrial electricity prices are generally lower than residential prices to support production activities and maintain competitive commercial consumption. However, contrary to this global trend, the average ratio of industrial to residential electricity prices in Iran has increased in recent years, signaling a structural imbalance in the tariff system and support policies. Under the tiered pricing system, lower consumption levels are charged at cheaper rates, providing incentives for low-consuming groups. However, the segmentation of consumption and the determination of thresholds in Iran, particularly in tropical regions, require a thorough and equitable review. According to the 2020 tariff, in regular areas, the first tier (0–100 kWh), which offers the lowest rate, covers only about 25% of subscribers, while in Tropical Area 3, the first tier (0–1000 kWh) covers more than 93% of subscribers, resulting in a substantial subsidy for this group. This disproportionate subsidy has escalated to the point where, out of a total of 200 billion tomans in electricity subsidies during a hot month, more than 190 billion tomans (93%) is allocated to the first tier. Consequently, even with a significant increase in rates for higher tiers, it is impossible to fully eliminate subsidies for this region, and the financial imbalance in the electricity sector remains unresolved.
The objective of this comparative study is to examine the electricity tariff structures in Iran in relation to international standards, identify key challenges in defining consumption ranges and thresholds, and propose solutions to enhance economic efficiency, social justice, and transparency in the pricing process. The findings of this analysis could serve as a foundation for policymakers and regulatory bodies to reform the tariff tiers, adjust subsidies appropriately, and implement effective incentive rates, thereby ensuring both the financial sustainability of the grid and the promotion of optimized consumption and industrial production support
An Investigation Of Concepts Related To The Term "Waqt" (Mystical Time/Moment) In Seven Prose Sufi Works (Translations Of Risalat Al-Qushayriyya, Kashf Al-Mahjub, Tamhidat, Tazkirat Al-Awliya', 'Awarif Al-Ma'arif, Mirsad Al-'Ibad, Misbah Al-Hidayah)
Get PDFThe aim of this research is to investigate the concepts related to the term "waqt" (mystical time/moment) in seven prose Sufi works. The research method is descriptive-analytical using library resources. For the perfect Sufis, waqt has the status of a servant whom they can control and influence as they wish, while for the imperfect ones and those who have not reached the ultimate level of gnosis, waqt has the status of a sovereign who influences their being and subjects them to whatever state it desires. According to the Sufis' view, waqt can be either permanent or transient. This research also attends to another matter that previous researchers have not addressed separately, which is the factors that waste and disturb waqt; although this may seem simple and rudimentary, it is an important and original discussion. Another point highlighted in this research is the concepts that are somehow related to waqt, either directly or indirectly. In the books studied in this research, in addition to the well-known mystical meaning of waqt, it also has a lexical meaning referring to time, period, or era, and sometimes compound words are formed using this term
Innovative Metallurgical Materials for Enhancing Medical Devices and Healthcare Infrastructure: Applications in Emergency Services, Nursing, Health Administration, and Epidemiological Monitoring
Get PDFThe integration of administrative and metallurgical materials in healthcare presents transformative opportunities across various sectors. This study explores their applications in enhancing emergency services, nursing, health administration, epidemiological monitoring, and tools supporting psychologists. Innovations in metallurgical materials, including titanium alloys, stainless steel, and biocompatible coatings, have improved medical device efficiency, safety, and durability. By focusing on interdisciplinary applications, the research highlights the critical role of these materials in creating durable, hygienic, and ergonomic healthcare solutions. Special attention is given to developing safe tools for psychologists, emphasizing their utility in diagnostic and therapeutic settings. This paper underscores the importance of metallurgical advancements in addressing modern healthcare challenges, proposing directions for future research and development
A Comprehensive Review of Airborne Metal Exposures and Their Impact on Nurses' Health: Analyzing Occupational Risks and Preventive Measures
Get PDFThis comprehensive review explores the impact of airborne metal exposures on nurses' health, focusing on the occupational risks associated with healthcare settings. Nurses, as the backbone of healthcare systems, are exposed to various environmental pollutants, including metals, during routine clinical activities. This review critically examines the sources of airborne metals, such as those generated by medical equipment and patient treatments, and discusses the potential health effects, particularly respiratory and neurological disorders. The evidence presented highlights the significance of these exposures, which have been under-recognized despite their growing presence in healthcare environments. The review also identifies the gaps in existing literature, especially regarding the specific risks faced by nurses, and proposes preventive measures, including enhanced monitoring, the use of personal protective equipment (PPE), and the adoption of safer medical technologies. By addressing these challenges, the review aims to improve nurse safety and contribute to the development of more effective health protection policies in healthcare settings
Outcome of Antidepressants Treatment among Adult Patients in KSA: A Cross-Sectional Study
Get PDFObjective: This research aims to determine the Outcome of Antidepressants Treatment among Adult Patients in KSA.
Methods: This study will employ a cross-sectional design to assess the outcomes of antidepressant treatment among adult patients diagnosed with depression in Saudi Arabia. This design will allow for data collection at a single point in time, facilitating the examination of treatment effectiveness and related factors. The sample size undertaken for the study was 680 in order to understand better the factors responsible.
Results: The study included 680 participants. The most frequent age among them was 34-41 years (n= 198, 29.1%%) followed by 26-33 years (n= 183, 26.9%), then 42-49 years (n=137, 20.1%), 50 and more years (n=126, 18.5%), finally age from 18-25 years (n=36, 5.3%). The most frequent gender among study participants was male (n= 397, 58%) and female (n= 283, 42%). Study participants' most frequent marital status was married (n= 475, 69.9%), followed by single (n= 151, 22.2%), then divorce (n=36, 5.3%), and widow (n=18, 2.6%). The participants were asked if they smoked, and the majority's responses were no (n=587, 86%) and yes (n=93, 14%). Depression duration among study participants, with most of them not diagnosed with depression (n= 587, 45.9%) and depression duration (n= 93, 14%). The participants who were diagnosed with depression were asked if they stopped taking antidepressant medications when they felt better, and the majority's responses were no (n=61, 65.6%) and yes (n=32, 4.7%). The participants who were diagnosed with depression were asked if they stopped taking medications when they felt worse after taking them, and the majority's responses were no (n=70, 10.3%) and yes (n=23, 3.4%).
Conclusion: The findings of this study highlight critical aspects of antidepressant treatment outcomes among adults in Saudi Arabia. Despite the established effectiveness of antidepressant medications, adherence remains a significant challenge, with notable percentages of participants reporting discontinuation of medications both when feeling better and worse. Sociodemographic factors, such as age, gender, and marital status, play a role in shaping treatment patterns, but they do not fully account for variations in adherence. Additionally, the results underscore the importance of addressing subjective factors, such as patients' beliefs about medication efficacy and side effects, significantly impacting adherence rates
The Impact of Value Engineering on Company Performance in the Automotive Industry in Kuwait
Get PDFThe automotive industry in Kuwait faces significant challenges in maintaining competitiveness and operational efficiency in an increasingly complex and globalized market. Value engineering (VE), a systematic method for improving the value of products or services by analyzing function, has emerged as a critical tool for enhancing company performance. Despite its potential, the application of VE in the Kuwaiti automotive sector remains underexplored, and its impact on company performance is not well-documented. This systematic review aims to synthesize existing empirical research on the relationship between value engineering practices and company performance in the Kuwaiti automotive industry. The review follows the methodology guidelines outlined in the Joanna Briggs Institute (JBI) Methodology for Systematic Reviews and is reported according to the PRISMA 2020 guidelines. The review protocol was registered with PROSPERO (ID CRD42021277463). The guiding question was formulated using the PEO (population, exposure, and outcome) format, with "P" representing the automotive industry in Kuwait, "E" representing value engineering practices, and "O" representing company performance. The findings highlight the significant benefits of integrating value engineering with lean practices, digital transformation, and other methodologies to enhance operational efficiency, reduce costs, and improve overall company performance. However, there are still research gaps that need to be addressed, particularly concerning the long-term impact of these practices, stakeholder perspectives, and the integration of multidisciplinary approaches. By adopting a comprehensive approach and conducting further empirical research, the Kuwaiti automotive industry can achieve sustainable competitive advantages and meet the evolving demands of the global market
Production of Fuel Oil from Waste Low Density Polyethylene and its Blends on Engine Performance Characteristics
Get PDFThis research paper focuses on converting waste low density polyethylene (LDPE) plastic to fuel oil using thermal degradation through a pyrolysis reactor. The process involves heating the LDPE plastic in the reactor with purging of nitrogen gas to maintain an inert atmosphere in the reactor, with a retention time of 2-3 hours until it melts and forms vapour, which is then condensed in a container. The resulting fuel oil is analyzed for its physical properties and compared with standard diesel. The fuel oil produced has properties that agree with the standard, including a carbon residue of 0.01, density of 785.1 kg/m3, flash point of 68oC, gross calorific value of 44,141 kJ/kg, kinematic viscosity of 2.18 cSt, pour point of -50oC, and sulfur content of 32 ppm. The fuel oil is then subjected to engine performance and emission tests in a CI Engine by blending it with diesel. The results show that a diesel engine can run on a blend of 50% fuel oil and 50% diesel fuel, but the engine vibrates when the fuel oil content exceeds 50%. The oil-diesel blend has lower brake-specific fuel consumption and higher exhaust gas temperature than diesel fuel, but it also produces higher NOx, CO, HC, and smoke emissions than diesel. Overall, the blend has significant advantages over conventional diesel fuel in terms of fuel efficiency, but it also has some drawbacks in terms of emissions