bluuebunny/crossref_metadata_2025 huggingface dataset:
Power Quality Improvement of PV fed Grid Connected System using ANN Controlled Shunt Active Power Filter
Authors: Ambati Giriprasad , Dinesh Kumar A. Ganga , Raghu Thumu , Seshukumari B Venkata , Duvvuru Raja Reddy , Reddy Ch. Rami
Published: December 2024

Harmonics are common in integrated power systems, especially with the increasing use of nonlinear loads (NLL), such as those found in photo voltaic (PV) systems connected to the grid. Traditional LC filters Shunt active power filters (SAPF) have been developed to effectively correct harmonics and improve power quality performance. This study presents a three-phase voltage-fed SAPF implementation to mitigate harmonics using an artificial neural network (ANN) controller. The SAPF control system focuses on generating reference source currents to counterbalance the harmonic effects caused by NLL. The model's effectiveness is validated using experimental data gathered from a nonlinear load through MATLAB/Simulink simulations.
Load modeling of electric bus charging station from data obtained through Phasor Measurement Units
Authors: Isaza – Ruget Ricardo , Perilla Cristhian , Rosero-García Javier
Published: December 2024

While the increased adoption of electric vehicles (EVs) is a promising alternative to reduce CO2 emissions, it creates new challenges for the power grid due to increased energy demand and power quality (PQ) issues. These impacts vary depending on several factors such as the level of EV adoption, charging technology, network voltage level, charging patterns, charging station location, battery condition, and driving habits. Analyzing these impacts and developing solutions, such as characterizing the demand curve for charging stations and understanding EV charging patterns, is crucial to ensure a sustainable transition to an electrified EV future. A study using the ZIP load model that represents voltage dependence by combining constant impedance (“Z”), constant current (“I”), constant power (“P”) components, and phasor measurement units (PMUs) demonstrates the effectiveness of EV demand characterization. The importance of this aspect for grid stability and charging management is highlighted.
Comparative study of physical and mechanical properties of a light plaster mortar based on the "SPADAR" foam ceramic granules and similar light fillers
Authors: Gudkov Alexey N.
Published: December 2024

Introduction. Plasters are still one of the most popular materials for finishing of facades of buildings. Modern plasters are produced mainly in the form of ready-to-use dry mixes. Manufacturers set themselves the task of obtaining not only plaster mixtures meeting standards, but also having hydrophobicity, low density, thermal conductivity and other features that determine the functionality of the plaster coating. In this regard, there is a need to develop and implement plaster mixtures based on new types of light aggregates.

Aim. To conduct comparative studies of the physical and mechanical properties of a light plaster mortar using the "SPADAR" foam ceramic granules and plaster mortars with similar fillers as a light filler.

Materials and methods. The research was carried out on light plaster mortars using as light fillers: "SPADAR" and foam ceramic granules from another manufacturer ("KERWOOD"), foam glass granules, expanded perlite sand. The parameters of density, strength under axial compression, water absorption during capillary suction and thermal conductivity of a light plaster mortar in a dry state were studied. The tests were carried out according to standard methods.

Results. The comparative technical characteristics of the studied plaster compositions are determined. During the analysis of the data obtained, the advantages of plaster compositions using foam ceramic granules as a light filler were revealed. Based on the data obtained, the composition of a light plaster mortar with a density of up to 700 kg/m3 using the "SPADAR" foam ceramic granules was developed.

Conclusions. The composition of the plaster based on the "SPADAR" foam ceramic granules turned out to be the most effective by the obtained values of the studied characteristics in total. In many ways, the obtained values of the technical characteristics of this plaster studied in this work are provided precisely by the "SPADAR" foam ceramic granules. Based on the results obtained, it is necessary to investigate other properties of the developed compositions of light plaster mixtures (adhesion, vapor permeability, moisture-proof properties with respect to the mineral base, frost resistance, etc.).
HOW FAMILY DNA CAN CAUSE LUNG CANCER USING MACHINE LEARNING
Authors:   University Of South Dakota, USA, Miah Jonayet
Published: December 2024

Lung cancer continues to be one of the leading causes of cancer-related mortality globally. While environmental factors, particularly smoking, are recognized as primary contributors, growing research shows that genetic predisposition, especially family-linked inheritance, plays a significant role in lung cancer susceptibility. Recent advancements in genomics and machine learning (ML) are providing new avenues for understanding these inherited risks. This review provides an in-depth analysis of how familial DNA influences lung cancer development, highlighting how machine learning models can be used to identify genetic markers associated with increased risk. By reviewing current findings and methodologies, we aim to bridge the gap between genetic susceptibility and the application of ML models in predictive healthcare.
Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds
Authors: Echemendía Radell , Montgomery Carlee A , Cuzzucoli Fabio , Burtoloso Antonio C B , Murphy Graham K
Published: December 2024

A novel study on the hypervalent iodine-mediated polyfluoroalkylation of sulfoxonium ylides was developed. Sulfoxonium ylides, known for their versatility and stability, are promising substrates for numerous transformations in synthetic chemistry. This report demonstrates the successful derivatization of sulfoxonium ylides with trifluoroethyl or tetrafluoropropyl groups, and provides valuable insights into the scope and limitations of this approach. Nineteen examples have been prepared (45–92% yields), with structural diversity modified at two key sites on the sulfoxonium ylide reactants. Finally, DFT calculations provided insights about the mechanism of this transformation, which strongly suggest that an SN2 reaction is operative.
The Correlation of CEO Power, Gender and Product Market Competition on Firm Value in the Property and Real Estate Sector
Authors: Pangesti Eka Ningtyas , Mustikowati Rita Indah , Asna Asna , Firdaus Riril Mardiana
Published: December 2024

This study aims to analyse the relationship between Chief Executive Officer (CEO) Power, gender, Product Market Competition on firm value. The research design was quantitative method with an associative approach. The population were property and real estate sector companies listed on the Indonesia Stock Exchange from 2019 to 2022, total of 144 sample data from 36 companies. The dependent variable is firm value, the independent variables are CEO power, gender and product market competition. Chief Executive Officer (CEO) power is measured by the parameters of age, education level and share ownership. Firm value is measured using Tobins'Q. Analysis of the level of competition used the industry-adjusted price-cost margin (IPCM) approach. The analysis technique used is Spearman correlation. The results showed that there was no significant relationship between CEO power: age and share ownership, as well as CEO gender on firm value, while there was a significant relationship between CEO power: education level and product market competition on firm value.
МОДЕЛИРОВАНИЕ ПОЖАРА В ДВУХПУТНОМ ПЕРЕГОННОМ ТОННЕЛЕ МЕТРОПОЛИТЕНА
Authors: А.А. Абашкин , А.В. Карпов , И.Р. Хасанов
Published: December 2024

Рассмотрены особенности развития пожаров в двухпутных тоннелях метрополитенов. Представлены результаты полевого математического моделирования различных сценариев развития пожара. На основе компьютерных расчетов и анализа режимов проектных аварий установлено, что развитие пожара в двухпутных тоннелях сопровождается интенсивным распространением продуктов горения. Основными сценариями аварий, при которых необходимо обеспечивать безопасную эвакуацию людей из перегонного двухпутного тоннеля, являются пожар в аппаратном отсеке головного вагона электропоезда и горение кабельной линии перегонного тоннеля.

The analysis of fires at subway facilities has shown that the most complex and catastrophic fires are associated with rolling stock when it is in the tunnel. Fires in tunnels are characterized by the rapid spread of fire hazards, as well as the possible collapse of structures and technological equipment. The peculiarity of fire development in double-track tunnels is the possibility of stopping the movement of electric trains in the opposite direction as a result of fire spread, which leads to the involvement of more passengers in emergency situation. When assessing the fire hazard situation in double-track tunnels, it is also necessary to take into account the possibility of fire spread not only from one carriage to another, but also to a neighbouring train standing on the adjacent track of the tunnel. This study examines fire scenarios and simulates the spread of fire hazards in modern double-track subway tunnels. To calculate the spread of combustion products in double-track subway tunnels, there was used a field fire simulation method based on the SOFIE software package, which has shown its effectiveness in simulating fires in road and railway tunnels. The six main fire scenarios in a double-track subway tunnel were adopted as a result of the analysis of emergency situations: 1 – contact rail fire; 3 – fire in the inter-car space; 4 – fire in the hardware compartment behind the driver’s cabin; 5 – burning luggage in the cabin of the wagon; 6 – burning cable line from cables that do not prevent from burning. Based on computer calculations and analysis of design accident modes, it has been established that the occurrence and development of fire in double-track tunnels is accompanied by an intensive spread of combustion products. The main accident scenarios in which it is necessary to ensure the safe escape of people from a double-track subway tunnel are a fire in the hardware compartment of the control car of an electric train and the burning of the cable line of the tunnel.
ОГНЕВЫЕ ИСПЫТАНИЯ ФРАГМЕНТОВ НАРУЖНЫХ СТЕН ЗДАНИЙ ИЗ НЕГОРЮЧИХ ПОЛИСТИРОЛБЕТОННЫХ БЛОКОВ
Authors: В.А. Рахманов , В.И. Мелихов , Г.И. Капаев
Published: December 2024

Приведены результаты стандартных пожарно-технических испытаний на огнестойкость и пожарную опасность фрагментов стен (простенков) в виде кладки на цементно-песчаном растворе блоков, изготовленных из негорючего полистиролбетона марки по средней плотности D300. Результаты испытаний подтвердили возможность применения такой кладки в наружных стенах многоэтажных зданий без ее обязательной облицовки негорючими материалами.

In recent years, the Institute VNIIzhelezobeton has created, standardized and patented a unique insulating and structural wall material – incombustible polystyrene concrete of medium-density of D300 grades, which has sufficiently high strength and low thermal conductivity, providing a high degree of thermal protection when used in external non-bearing walls of multi-storey civil buildings. There were carried out standard fire tests for fire resistance and fire hazard for samples of wall structures in the form of masonry on a cement-sand mortar made of incombustible polystyrene concrete blocks with a density of D300. As a result of the tests, the fire-resistance limit EI 90 and the fire hazard class K0(45) were confirmed, which makes it possible to use incombustible polystyrene concrete wall blocks with a density of D300 without facing them with incombustible materials in the external non-bearing walls of civil buildings up to 75 m high with 1st degree of fire resistance and C0 class of structural fire hazard inclusively.
ИДЕНТИФИКАЦИЯ НЕРЕГЛАМЕНТНЫХ СОБЫТИЙ В ПОМЕЩЕНИЯХ С РАЗНЫМИ ГАБАРИТАМИ И ГЕОМЕТРИЕЙ
Authors: М.И. Глотов , С.С. Кропотова , П.А. Стрижак
Published: December 2024

На основании экспериментальных исследований получены аппроксимационные зависимости для расчета поправочных коэффициентов, необходимых для прогнозирования времени срабатывания различных типов пожарных извещателей (дымовых, тепловых, пламени), а также численных значений температур и концентраций кислорода, оксида и диоксида углерода в помещениях с отличающимися габаритами. Коэфициенты позволяют ввести поправку на срабатывание перечисленных датчиков, спрогнозировать частоту их срабатывания с учетом высоты, объема и площади помещения. Аппроксимационные выражения для расчета поправочных коэффициентов рассчитаны с учетом наиболее распространенных причин, приводящих к нештатной ситуации в помещени: неосторожное обращение с огнем и нарушение правил эксплуатации нагревательного оборудования.

By extrapolating the database on the response characteristics of fire detectors of different types, there have been obtained correction factors necessary to predict the response time of smoke, heat and flame fire detectors, as well as numerical values of temperatures and concentrations of oxygen, carbon oxide and carbon dioxide in rooms with different dimensions. The use of the proposed correction factors will allow us to obtain a database of sensor response characteristics using indirect methods, that is, without conducting calibration experiments in real production facilities. There have been obtained correction factors using room layouts with volumes of 0.125 m3, 2 m3 and 27 m3. To test the obtained coefficients, test experiments were carried out with registration of the main characteristics of the response of fire detectors of different types. There have been formulated recommendations for their use, based on the results of testing correction factors.
ОРГАНИЗАЦИОННЫЕ, КОНСТРУКТИВНЫЕ И ТЕХНИЧЕСКИЕ МЕРОПРИЯТИЯ, НАПРАВЛЕННЫЕ НА ПОВЫШЕНИЕ УРОВНЯ ПОЖАРНОЙ БЕЗОПАСНОСТИ ПРИ ПРИМЕНЕНИИ В СТРОИТЕЛЬСТВЕ СИСТЕМ ФАСАДНЫХ ТЕПЛОИЗОЛЯЦИОННЫХ КОМПОЗИЦИОННЫХ С НАРУЖНЫМИ ЗАЩИТНО-ДЕКОРАТИВНЫМИ ШТУКАТУРНЫМИ СЛОЯМИ И ГОРЮЧИМ ПОЛИМЕРНЫМ УТЕПЛИТЕЛЕМ
Authors: В.С. Горшков , О.В. Фомина , П.А. Чернышов , С.В. Смирнов
Published: December 2024

Современные требования к энергоэффективности жилых и нежилых зданий предполагают использование в строительстве инновационных решений, эффективных теплоизоляционных материалов, энергосберегающих технологий отопления и освещения помещений. Одним из таких решений, набирающих все большую популярность в нашей стране, является устройство наружных систем теплоизоляции фасадов, которые можно использовать как при строительстве, так и для звуко- и теплоизоляции наружных стен с внешней стороны при реконструкции зданий. К наружным системам звуко- и теплоизоляции фасадов относятся два основных вида: фасадная теплоизоляционная композиционная система с наружными защитно-декоративными штукатурными слоями (СФТК или штукатурная система теплоизоляции) и навесные фасадные системы с воздушным зазором (НФС или вентилируемые фасады). В результате проведенных исследований по определению причин и процессов развития (распространения) пожара по наружным системам звуко- и теплоизоляции фасадов был накоплен уникальный опыт. Также были проведены научные и экспериментальные исследования в аккредитованных научных центрах и лабораториях. Это позволило определить ряд конструктивных требований обеспечения пожарной безопасности СФТК с горючим полимерным теплоизоляционным материалом.

The article presents examples of analysis of fires with the spread of flame on the outer facades using plaster thermal insulation systems that show their particular hazard and the need to determine the structural features of these facade systems, which have a significant rate of spread of combustion and influence on the development of the fire. There is determined the nature of the vertical spread of the fire on the facade of the building, determined by the influence of the fire hazard of the building structures of the external walls (facades), as well as by the structural features of the buildings and the parameters of the development of the resulting fire. Taking into account the expanding market of use of facade systems in construction, the article considers the peculiarities of their fire hazard, gives recommendations on the installation and use of thermal insulation plaster systems (SFTK). The main organizational, structural and technical measures to improve fire safety of facade thermal insulation systems with external protective and decorative plaster layers and combustible polymer insulation are presented.
ОЦЕНКА МНОГОЛЕТНИХ СЕЗОННЫХ КОЛЕБАНИЙ ПОКАЗАТЕЛЯ КОЛИЧЕСТВА ПОЖАРОВ В РОССИЙСКОЙ ФЕДЕРАЦИИ
Authors: К.С. Власов , Е.Е. Злобнова , А.Н. Куренной , Е.П. Рожков
Published: December 2024

Рассмотрена динамика показателя суточного количества пожаров в Российской Федерации за 2010–2023 гг. Отмечено, что эта динамика имеет сезонную зависимость. Предложен метод, основанный на использовании сглаженной функции среднего суточного количества пожаров и позволяющий прогнозировать вероятность возникновения таких пожаров. Данный метод можно применить при планировании деятельности оперативных подразделений противопожарной службы в масштабе среднесрочного прогнозирования и в долгосрочной перспективе. Приведены результаты расчетов рассматриваемого показателя применительно к условиям г. Балашихи.

The dynamics of the indicator of the daily number of fires in the Russian Federation for 2010–2023 is considered. It is noted that this dynamics has a seasonal dependence. There is proposed the method based on the use of a smoothed function of the average daily number of fires which allows to predict the probability of such fires. This method can be applied in planning the operational fire units activities on the scale of medium-term forecasting and in the long term. There are presented the results of calculations of the indicator under consideration in relation to the conditions of Balashikha town.
ПОРЯДОК РАЗРАБОТКИ ИНДИКАТОРОВ РИСКА НАРУШЕНИЙ ОБЯЗАТЕЛЬНЫХ ТРЕБОВАНИЙ ПОЖАРНОЙ БЕЗОПАСНОСТИ В ОТНОШЕНИИ ПРОДУКЦИИ ПОЖАРНО-ТЕХНИЧЕСКОГО НАЗНАЧЕНИЯ
Authors: Д.С. Адамов , А.В. Матюшин , Е.В. Козырев , В.А. Сорокин
Published: December 2024

Описан механизм реализации задач государственной политики Российской Федерации в области пожарной безопасности на период до 2030 на примере разработки индикаторов риска нарушений обязательных требований пожарной безопасности. Приведены и описаны решаемые задачи для разработки научно-обоснованных индикаторов риска нарушения обязательных требований при осуществлении ФГПН в отношении средств обеспечения пожарной безопасности и пожаротушения. Предложено применение метода корреляционного и регресивного анализа для научного обоснования и определения индикаторов риска. Рассмотрены актуальные вопросы совершенствования внепланового контроля, осуществляемого органами государственного пожарного надзора, в современных условиях.

The mechanism of implementing the tasks of the state policy of the Russian Federation in the field of fire safety for the period up to 2030 is described by the example of the development of risk indicators for violations of mandatory fire safety requirements. The tasks to be solved for the development of scientifically based risk indicators for violation of mandatory requirements in the implementation of the Federal state fire supervision for fire safety and fire extinguishing means are presented and described. The application of correlation and regression analysis method for scientific substantiation and determination of risk indicators is proposed. The current issues of improving the unscheduled control carried out by the state fire supervision authorities in modern conditions are considered.
Hidrodiseccion Ecoguiada Peritendinosa
Authors: Bula Cardona William Esteban , Meneses Rueda Larry Mansur , Estrada Morillo Claudia Maribel , Velasco Villa Halma Ruth , Suárez Castillo Valentina Isabella , Otero Arteaga Luisa Mary , Arce Marin Kevin Alejandro , Soler Sierra Victor David
Published: December 2024

La patología peritendinosa incluye inflamación y degeneración de tejidos alrededor de los tendones, común en personas activas y en trabajos repetitivos, afectando principalmente el hombro, muñeca y tendón de Aquiles. Es más frecuente con la edad, especialmente en mayores de 40 años, y varía según el sexo. El tratamiento se centra en reducir el dolor e inflamación mediante reposo, AINEs y fisioterapia. Una técnica moderna es la hidrodisección ecoguiada, la cual es un procedimiento que consiste en infiltrar suero a presión con una aguja para separar las estructuras que comprimen los tendones o nervios, guiado por ultrasonido con el fin de liberar adherencias para mejorar la movilidad y aliviar el dolor de forma mínimamente invasiva.En el presente artículo se hablará de la eficacia del uso de la Hidrodisección ecoguiada y otros tratamientos asociados en la patología peritendinosa.
Reutilización del Plástico en Instrumentos Musicales desde las Instituciones Educativas para un Tumaco Sostenible
Authors: Rosero Moran Elsa Jackeline , Carvajal López Juan Carlos , González Avellaneda Efraín
Published: December 2024

La intención del presente artículo es proponer la reutilización del plástico en la fabricación de instrumentos musicales en las instituciones educativas de Tumaco. La selección del enfoque, en la presente es mixta y está basado en el paradigma pragmático, con alcance descriptivo, bajo el método de la investigación-acción participativa, cuya secuencia se estableció en cinco fases (diagnóstico, diseño, implementación, evaluación, reflexión), en una población 17 estudiantes de noveno grado y tres docentes de la Institución Educativa IEBATAP, Llorente, Municipio Tumaco, Nariño. Las técnicas de recolección incluyen observación, revisión documental, entrevistas y diagnósitco. Los datos del diagnóstico, fueron sometidos a análisis estadísticos. Por otro lado, los datos de la entrevista se trataron con métodos cualitativos. Estos resultados evidención la necesidad de proponer la propuestas y permitió diseñar e ijmplementar la propuesta educativa sostenible. De esto se concluyó, que la fabricación de instrumentos de percusión colombianos con materiales reciclados generó un ambiente de aprendizaje dinámico y estimuló la innovación. Esta iniciativa no solo contribuye a mitigar la problemática ambiental, sino que también promueve el desarrollo de emprendimientos sostenibles y fortalece la educación ambiental en el contexto escolar y su comunidad.
Efectos coadyuvantes de la terapia con metformina en el síndrome de ovario poliquístico. Revisión bibliográfica.
Authors: Capelo López Naommy Rashell , Encalada Cedillo Kerly Isamary , Alvaro Guerrero Carla Madeline , Gadvay Requelme Mishelle Katherine , Briones Morales Victor Euclides
Published: December 2024

El síndrome de ovario poliquístico (SOP) es una condición compleja y multifactorial que afecta a un gran porcentaje de mujeres en edad fértil, presentándose comúnmente con hiperandrogenismo, resistencia a la insulina y disfunción ovárica. A pesar de las inconsistencias en los criterios de diagnóstico, la prevalencia es significativa. Se realizó una revisión de la literatura para analizar los efectos adicionales de la metformina, un tratamiento frecuente en SOP debido a su impacto positivo en la resistencia a la insulina. Se llevó a cabo una búsqueda exhaustiva en bases de datos científicas empleando términos específicos sobre SOP y metformina, incluyendo estudios actuales de alta calidad. La revisión mostró que la metformina no solo mejora la sensibilidad a la insulina, sino que también ayuda a reducir la hiperandrogenemia, favorece la fertilidad y reduce el riesgo de comorbilidades como enfermedades cardiovasculares y ciertos tipos de cáncer. Además, estudios recientes sugieren beneficios en problemas reproductivos y gestacionales. La metformina es una terapia valiosa para el manejo del SOP, impactando positivamente en síntomas y riesgos asociados, aunque su efecto a largo plazo requiere más investigación.
Aplicaciones De Los Métodos De Análisis De Clúster y Correspondencia En El Estudio De Resultados De Examen De Admisión De La Universidad Nacional De San Antonio Abad Del Cusco, 2022
Authors: Catunta Guillén Luz Marina , Soncco Tumpi Santiago , Huamán Guzmán Abelardo
Published: December 2024

El objetivo de la presente investigación fue, analizar las APLICACIONES DE LOS MÉTODOS DE ANÁLISIS DE CLÚSTER Y CORRESPONDENCIA EN EL ESTUDIO DE RESULTADOS DE EXAMEN DE ADMISION DE LA UNIVERSIDAD NACIONAL DE SAN ANTONIO ABAD DEL CUSCO, 2022, se aplicaron técnicas estadísticas del análisis de conglomerados como el algoritmo bietapico, PAM (partition around medoids) y clara (Clustering Large Applications) para poder cumplir con el objetivo trazado, la investigación tuvo un enfoque cuantitativo, de alcance descriptivo, mientras que el diseño de investigación es no experimental, de tipo transversal; así mismo la población de estudio son los estudiantes que, ya egresaron de la educación básica regular quienes postularon en los diferentes semestres de la universidad San Antonio Abad del Cusco.Se han utilizado 3 algoritmos para poder conglomerar a los individuos, como el algoritmos de PAM (Partitioning Around Medoids) y CLARA (Clustering Large Applications) y el algoritmo bietapico, se calculó una matriz de distancias con la metodología de distancias mixtas de gower, en tanto se decidió utilizar el algoritmo bietapico por tener mejor medida de silueta de cohesión y separación; se determinó que 4 clústeres eran adecuados para describir los perfiles de los postulantes donde se observó que el clúster 1, tiene prevalencia de alumnos que no ingresaron cuando postularon, su edad promedio es 18.49 años y su nota promedio fue de 7.44, su procedencia en su mayoría es del Cusco, de sexo femenino, procedencia de colegio nacional y mayormente postulan al grupo D. En el clúster 2, tiene prevalencia de alumnos que si lograron una vacante en la UNSAAC, con edad promedio de 20.7 años y su nota promedio fue de 12.58, su procedencia mayormente es del Cusco, de sexo masculino, procedencia de colegio nacional; en el clúster 3, tiene prevalencia de alumnos que no ingresaron cuando postularon, su edad promedio es 18.49 años y su nota promedio fue de 7.67, su procedencia en su mayoría es del Cusco, de sexo masculino, procedencia de colegio particular y mayormente postulan al grupo A; en el clúster 4, tiene prevalencia de alumnos que no ingresaron cuando postularon, su edad promedio es 18.50 años y su nota promedio fue de 7.75, su procedencia en su mayoría es del Cusco, de sexo femenino, procedencia de colegio particular y mayormente postulan al grupo A.
Cooling Period Strategies in an Intermittent Usage Building: A Case Study of a Mosque in the Tropical Climate of Malaysia
Authors: Taufan Andi , Zaki Sheikh Ahmad , Tuck Ng Wai , Othman Nor’Azizi , Rijal Hom Bahadur
Published: December 2024

Mosques are used five times a day according to the prayer schedule, which follows the sun's position. Indoor thermal conditions in air-conditioned mosques are maintained with a cooling time pattern that follows prayer times. Therefore, an effective air conditioning operating strategy is needed for energy efficiency. This study aims to investigate the effect of air conditioning intermittent operation time strategies on the energy usage of a mosque. It involves reducing the cooling period before prayer time and swapping active air conditioning periods from pre-prayer calls to post-prayer in the base case. Field measurements in Universiti Teknologi Malaysia – Kuala Lumpur (UTMKL) mosque and simulation using DesignBuilder software were conducted to predict annual specific energy consumption. The results indicate a reduction in specific energy consumption of 5% by operating the air conditioning 10 minutes before the call to prayer. Shifting the pre-prayer call-post prayer cooling period results in an insignificant reduction in energy consumption of 0.3-0.6%; however, it can accommodate extended periods of comfortable conditions for people who perform prayers outside of congregational prayers on time. Furthermore, the results indicate that the cooling period after the prayer time affects the cooling load of the following prayer. This study provides information for architects, engineers, and other stakeholders towards improving energy consumption in religious buildings with intermittent occupancy.
Passive Control of Base Pressure and the Flow Development in a Duct with Sudden Expansion at Sonic Mach Number
Authors: Muhamad Zuraidi Nur Husnina , Khan Sher Afghan , Mohammed Sapardi Mohd Azan , Dixit Saurav
Published: December 2024

The primary purpose of this research is to investigate the effectiveness of rib as a passive control to control the flow development around the circular duct at different levels of expansion using Computational Fluid Dynamics (CFD). The nozzle pressure ratio (NPR), rib size, and rib orientation were considered in this research. The L/D ratio is from 3 to 5; the simulated NPRs were 1.5, 2, 3, 4, and 5. The rib was designed with a quarter circular shape to see the method's effectiveness. The focus was on the duct’s base pressure and wall pressure. The results show that the rib size and orientation strongly influenced the base pressure. The base pressure for the model with rib keeps increasing while the base pressure for the model with plain duct shows opposite results as the NPR increases. The base wall's pressure was not affected by nozzle pressure ratio only. Still, other characteristics, such as rib size and orientation, are significant in manipulating the result. However, the rib does not adversely impact the flow in the duct.
Diagnosing the Process of Forming Biofuel Combustion Mixtures in Diesel Engines by a Program to Compute Spray Volume
Authors: Nghia Mai Duc , Tuan Ho Duc
Published: December 2024

A diesel engine's injection and combustion mixture formation process are essential; it determines the engine's economic, technical, and environmental criteria. When the engine uses biofuel, fuel parameters such as viscosity, density, and surface tension affect the above process. Each engine using a specific fuel type will have to adjust injection parameters such as injection pressure and timing to ensure the injection process and formation of a homogeneous air-fuel mixture. Therefore, through the spray structure, it is possible to diagnose the process of combustion mixture formation, thereby making adjustments to the fuel injection system that will improve engine performance and reduce emissions of toxic exhaust gases. In this study, the article presents the content of building a program to compute spray volume using Matlab software. Through the spray volume, quickly diagnose the process of forming the biofuel-air mixture in the diesel engine combustion chamber, thereby determining the appropriate fuel injection system adjustment. Results of simulation and experimental research on 4CHE Yanmar engines installed on fishing vessels with fuel types DO, B5, B10, and B15 show that the B15 fuel mixture when used for the engine needs to be increased injection pressure is about 10% higher than DO fuel injection pressure.
Droplet Evolution and Stability of Water-in-Biodiesel Emulsion with Biosurfactant
Authors: Ghoto Asghar Ali , Abd. Aziz Abd. Rashid , Ismael Mhadi A.
Published: December 2024

Use of an alternative water-in-diesel emulsion (WiDE) fuel instead of pure diesel in a diesel engine reduces emissions and environmental pollution. However, as time passes, water from the emulsified fuel separates. Emulsion stability is affected by the amount of water, type of surfactant, and emulsion technique. Since biodiesel and biosurfactants are environmentally friendly as compared to pure diesel and chemical surfactants, biodiesel-emulsified fuel can reduce emissions, improve combustion, and improve engine performance. Water-in-diesel droplets split into tiny droplets during secondary atomization, which is believed to be caused by microexplosions. In this study, the effect of biosurfactant on the stability and microscopic behaviour of water-in-biodiesel emulsion (WiBDE) fuel were examined. A mixture of B10 biodiesel, 5% water, and a mixture of surfactant (63% lecithin and 37% TWEEN 85 (0.5–3%)) was emulsified for 20 minutes by using a magnetic stirrer at 1500 rpm. Six WiBDE fuel samples were observed for 10 days, and the microscopic behaviour of fuel droplets was examined. The evolution of droplets leading to micro-explosions was captured at 200 °C, 300 °C, and 400 °C. WiBDE-5, having a 2.5% surfactant concentration, is highly stable and reduces the time of micro-explosion of droplets, which can improve combustion and engine performance.
Study on the Effect of Intake Air Temperature towards RCCI Mode Engine of Performance and Emission
Authors: Mohamed Abdul Majid Ahmad , Hamidi Mohd Adnin , Haiqal Muhammad Kamal , Yusop Ahmad Fitri
Published: December 2024

Significant progress has been made in the field of research pertaining to combustion engines to lower emissions such as nitrogen oxide (NOx) and carbon monoxide (CO). In recent years, the relative control compression ignition (RCCI) engine has been created to minimize emissions of nitrogen oxides (NOx). This research examines the influence of the intake air temperature has on RCCI-mode engines’ performance and emissions. A modified single-cylinder diesel engine was used to investigate the effects of changing intake air temperature and Primary Reference Fuel (PRF) over a spectrum of engine loads. The result shows that a higher air intake temperature for the RCCI strategy improved the performance of the RCCI engine, especially on fuel mixtures of B0 and PRF40, without comparing to a single fuel strategy, and reduced the amount of NOx emissions in the trade-off between UHC and CO compared to a single fuel strategy. In the not-too-distant future, one of our goals is to do more research on the influence that fuel octane has on port injection rate while maintaining the same values and parameters.
Effects of Dufour and Heat Generation on MHD Casson Fluid Flows Past an Inclined Oscillating Plate with Chemical Reactions and Thermal Radiation in a Rotating Porous Medium
Authors: Manigandan Chinnasamy , Senthamilselvi Sathiamoorthy , Deepa Sundar Rajan , Selvaraju Periyasamy
Published: December 2024

An analytical interpretation of unsteady-free convective hydromagnetic boundary layers is given in this work. It illustrates the impacts of Dufour radiation of heat, along with chemical reactions on a Casson fluid flowing by an inclined oscillating plate, a uniform magnetic field, and a rotating porous medium. The governing equations that had been solved by utilising the Laplace transform approach and the outcomes are shown. The numerical values of Casson fluid temperature, concentration, and velocity at the plate are visually represented for a range of relevant parameter values. The non-Newtonian fluid, which moves at a faster speed than the Newtonian fluid, has a Casson fluid parameter, which is examined and explained in this study. Moreover, the temperature trend increases with the Dufour number (Df), heat generation parameter (Q), and the reverse trend for thermal radiation parameter (R), Pradtl number (Pr), Schmidt number (Sc), as well as chemical reaction parameter (K). The concentration falls as the chemical reaction parameter (K) and Schmidt number (Sc) rise. We looked at the sped-up flow after the investigation to get measurable data, making sure to take into account things like Cason fluid parameter, Dofour number, and accumulation. Grashof values also findings speed decreases with increased radiation, chemical reaction, and Schmidth parameter levels. Our significant contribution to this research is an in-depth study of rotation with an inclined oscillating plate, which investigates the relationships between rotational forces, oscillation frequency, plate inclination, magnetic fields, and non-Newtonian features of Casson fluids. This work increases our understanding of how these parameters influence fluid behaviour, heat transfer, and mass transfer by offering a complete analytical framework that can be applied to a wide range of practical problems in fluids.In this research, my main contribution is rotation with an inclined oscillating plate.
Implementation of Interleaved Converter for Fast Charging Stations
Authors: Veerendra Arigela Satya , Lakshmi Kambampati , Sekhar Chavali Punya , Kappagantula Sivayazi , Kadirgama Kumaran , Sazali Norazlianie
Published: December 2024

The major goals of this effort are to create an electric vehicle charging station microgrid that combines the utility grid, a solar PV plant, and a bioenergy system as its primary energy sources. Here, the solar system is designed for 15kW, and the energy system is designed for 5kW. To improve the efficiency and maximize the performance of the distributed energy system, a DC-DC converter-based perturb and observe MPPT technique is implemented. The proposed arrangement makes it possible to build a microgrid that is effective, affordable, and distinctively local. The utilization range of electric vehicles is increasing rapidly and still in some areas it is limited due to more charging times. This can be improved by providing fast charging conditions that enable charging a vehicle in less time. To maintain these fast-charging conditions, an efficient, compact-sized DC-DC converter with high power output is required. This paper introduces an interleaved DC-DC power converter to meet the above requirements. The proposed interleaved multi-phase converter, which is part of fast charging stations, can charge the electric vehicle in less than 3 hours. To achieve high power density, ripple reduction on the output current and to improve the efficiency of the converter a space vector modulation technique is applied. The operation of an interleaved converter is analysed theoretically. Simulation analysis of the proposed interleaved power converter shows the good behaviour of the converter and charging conditions of various electric vehicle systems.
Assessment of Climate Change Impact in Tropical Buildings: Sensitivity Analysis of Light Shelf and Building Design Parameters for Daylighting and Thermal Balance
Authors: Abd Salam Nur Nasuha , Lannon Simon , Md Amin Noor Dina , Yusof Hanita , Rahmat Muhamad Hanafi , Abd Wahab Izudinshah
Published: December 2024

Climate change may lead to more intense sunlight in tropical regions, potentially increasing the daylight available for buildings. While this can enhance natural lighting inside buildings, it may also exacerbate issues such as glare and overheating if not properly managed through shading devices and glazing treatments. Nevertheless, common strategies to mitigate heat gain and glare such as shades and blinds often obstruct natural light, necessitating increased reliance on artificial lighting. The conflicting interplay between daylighting and thermal performance can undermine building performance if not carefully considered. Existing research on the influence of key design parameters in tropical climates tends to focus predominantly on heat gain mitigation, neglecting other aspects. This study addresses these gaps by examining the holistic daylighting and thermal energy performance of buildings to develop optimised façade and resilient designs against climate change. The investigation encompasses an analysis of 11 design parameters of light shelves and building characteristics that are critical during the initial design stage. Global sensitivity analysis (GSA) is employed to identify the most influential design parameters affecting useful daylight illuminance, uniformity ratio, cooling energy, and solar gain energy. A case study involving double-story terrace houses in Malaysia is employed, with analyses conducted for the present and future climates of three Malaysian cities (Kuala Lumpur, Bayan Lepas, and Kota Bahru). The findings reveal that, across all three cities, glazing transmittance is the most influential parameter for daylighting performance, while room depth assumes primary significance for thermal performance. Although the relative ranking of parameters remains consistent between present and future climates, their magnitudes differ. In summary, this paper gives designers insights into the critical design parameters essential for achieving a balanced and resilient daylight-thermal design in tropical climates at the initial stages of the design process.
Effect of Triple Glass Layers on the Thermal Performance of Windows
Authors: Chen You , Taib Nooriati , Kim Eonyong
Published: December 2024

This study introduces the application of software simulations to evaluate the performance of triple-pane glass windows to meet the requirements for energy-efficient thermal insulation. Using Therm 7.8.55 and Window 7.8.55 software, structural and physical heat transfer models for various single-frame plastic windows were developed. Numerical simulation methods were employed to calculate and analyse the impact of the number of glass layers on the windows' thermal performance, including the heat transfer coefficient and solar heat gain coefficient, to elucidate the energy-saving mechanisms. These simulations examined the physical properties of single-frame triple-glazed plastic windows, such as wind pressure resistance, airtightness, watertightness, and potential condensation on the inner surface. The results indicate that, under identical conditions, the heat transfer coefficient of single-frame triple-glazed plastic windows is reduced by 7.08%, and the solar heat gain coefficient is decreased by 4.18% compared to single-frame double-glazed plastic windows. Additionally, these windows' physical and economic performance meets the necessary standards. Furthermore, incorporating new materials such as Low-E glass can further enhance the thermal performance of the windows, significantly contributing to the reduction of overall building energy consumption.
Phase Change Material for Improving Building Thermal Comfort in Kurdistan
Authors: Nasih Al-Dalal Mohammed Syamand , Mustaffa Ahmad Fikri , Karaki Ali
Published: December 2024

The Kurdistan region of Iraq suffers from relatively high summer temperature which leads to overheating in office buildings where there is little to no air-conditioning installed. In summer, the temperature rises to around 45-53 °C which can be unbearable to building occupants. The high temperature can affect occupant thermal comfort and causes health issues. Phase chance materials (PCM) are considered as a useful passive cooling method that absorbs excessive heat when the room is relatively hot and releases the stored heat when the room temperature becomes less hot. This research aims to evaluate the effectiveness of using PCM to reduce the overheating of offices in Kurdistan region and to analyze potential factors that will affect the building temperature. The factors include environment-related (location of the building, climate change) and construction related (location of the PCM, insulation, heavyweight/lightweight construction). The potential outcome of this research may provide useful guidance about using PCM in office buildings in Kurdistan region for architects and engineers to decide when and where to use PCM. The building simulation is performed using DesignBuilder software where different types of PCM are investigated. Results from the building simulation show that PCM can reduce cooling energy consumption by about 1% as compared to when no PCM is used.
Effect of Change in Sulfuric Acid Concentrations and Different Temperatures on Corrosion of Heat-Treated Moderate Carbon Steel
Authors: Kassim Mohammad Takey Elias , Ibrahim Haider Ismael , Karash Emad Toma , Sultan Jamal Nayief , Omran Abdoulhdi Amhmad Borhana
Published: December 2024

This study looked at the effects of successive heat treatments (first quenching, first tempering, second quenching, and second tempering) on the corrosion rate of moderate carbon steel in a methodical manner. Using distilled water, the specimens were cooled at 10 oC following the initial quenching and at different temperatures (0, 10, 20, 30 oC) following the second quenching. Based on the results of repeated heat treatment experiments and corrosion rate experiments in these models, the moderate carbon specimens that underwent the heat treatments have a high corrosion resistance compared to the original models (prior to the application of the heat treatments). At different temperatures (298, 303, and 313 K) and concentrations (0.2, 0.3, and 0.4 N–H2SO4), in an acidic moderate. The study also showed that corrosion resistance decreases with concentration and with increasing corrosion-moderate temperature in heat-treated models. Another finding is that the models with the best corrosion resistance were those that underwent a second quench and cooling process. Another finding shows that the models with the highest corrosion resistance were those that experienced a second quench and were cooled in water at zero oxygen content.
Biodiesel Production from Waste Cooking Oil: A Review of Prospects and Challenges
Authors: Idris Muhammad , Abdul Rasid Ahmad Fuad , Mohd Zamberi Mahanum , Zhang Yang
Published: December 2024

The consumption of fossil fuels is increasing as people become more reliant on them. It is consequently vital to discover more environmentally friendly and sustainable alternative energy sources. Because of its considerable potential to reduce greenhouse gas emissions and its renewable nature, biodiesel derived from WCO has gained attention as a feasible alternative. Enhancing product quality and guaranteeing consistent economic growth are substantial challenges. This investigation aims to assess the feasibility of utilizing WCO as a renewable resource to produce biodiesel. In particular, the investigation investigates the feasibility of obtaining cost-effective and high-quality biodiesel results. To optimize outcomes, this investigation implements a transesterification approach that employs calcium oxide catalysts. Biodiesel's economic value and environmental benefits are assessed through the Life Cycle Cost Assessment (LCCA) assessment method. WCO biodiesel exhibits a high conversion rate and favorable physicochemical properties, as indicated by the results. Therefore, WCO biodiesel can meet the worldwide demand for fuel. The results show that WCO biodiesel has favorable physicochemical properties and a high conversion rate. As a result, WCO biodiesel can meet global fuel demand. It has the potential to generate many benefits for the environment, but there are problems with the collection and processing of WCO. However, WCO collection and processing issues still exist. Biodiesel derived from WCO reduces harmful pollutants, improves public health and air purity, according to engine performance tests.
Enhancing Convective Heat Transfer in Circular Microchannels through Response Surface Methodology of Orifice Geometry: A Computational Fluid Dynamics Approach
Authors: Putra Harsono Dimas Agung , Rahmadiawan Dieter , Irwansyah Ridho
Published: December 2024

This research investigates the use of Computational Fluid Dynamics (CFD) simulation to model circular microchannel pipes with orifices as a passive heat transfer enhancer. Different parameters, including microchannel geometry, Reynolds number, and heat flux, are employed in this research. The analysis results indicate that factors such as the distance between the inlet and orifice, and Reynolds number significantly influence the system performance, particularly in terms of pressure drop and Nusselt number. The addition of an orifice to a microchannel also affects the efficiency of heat transfer and the pressure drop. The results were further analysed using the Response Surface Methodology, which revealed that a microchannel with a Reynolds number of 90 and a distance between the inlet and orifice of 2.83238 mm provides an optimum solution. In conclusion, optimising these parameters can lead to more efficient and optimal designs for microfluidic applications.