bluuebunny/crossref_metadata_2025 huggingface dataset:
Mind Marvel platform: Transforming attention deficit hyperactivity disorder challenges into opportunities through interactive gaming
Authors: Babu Noyal , Buckley Neil , Secco Emanuele Lindo
Published: December 2024

Attention deficit hyperactivity disorder (ADHD) is a neurological disorder marked by a pattern of inattention, hyperactivity, and/or impulsivity. Since the signs and symptoms of ADHD can be observed in the early stages of childhood, a prompt diagnosis, along with effective treatment, is of utmost importance. Once a child is diagnosed, various treatments are available, including behavioral therapy, medication, and cognitive training. Recent research has shown that individuals with ADHD tend to respond well to interactive games and technologies, such as virtual reality (VR) since such activities require timely task completion, attention to detail, and concentration. Thus, the purpose of this study is to leverage on game therapy for ADHD and develop Mind Marvel, a unique platform for individuals with ADHD. This platform combines the design of interactive webpages with a VR environment, transforming ADHD challenges into opportunities through such interactive gaming. In this case, the user answers a set of questions and plays a VR game by using a computer mouse and keyboard or a commercial VR controller. This platform has been tested under laboratory conditions, after which preliminary results indicate that the capabilities of the Mind Marvel system effectively support individuals with ADHD and raise awareness of their conditions.
Advancing EEG-Based Emotion Recognition: Multimodal Techniques, Channel Optimization, and Insights into Subjective Emotion Perception
Authors:   , Dharia Shyamal Y.
Published: December 2024

This dissertation explores the application of electroencephalography (EEG) in identifying and understanding the neural mechanisms of emotional responses. Using a non-invasive and economically efficient OpenBCI Cyton wireless EEG system, this research developed and assessed several technological advancements for optimal neural activity recording. Key among these were the implementation of both software and hardware triggers to ensure precise data acquisition and a comparative analysis of dry versus semi-dry electrodes. The findings suggest that semi-dry electrodes, when used in conjunction with a flexible cap, not only minimize noise but also improve participant comfort, thereby offering clear benefits over the dry electrodes with rigid cap structure by OpenBCI. Additionally, our study of event-related potentials (ERP), which included measures of subjective emotional responses, indicates that the impact of motion versus no motion in stimuli diminishes at higher emotional intensities. This observation suggests that at elevated levels of emotional arousal, the emotional content of the stimuli becomes more salient to the perceiver than the associated motoric information. Moreover, this thesis delineates the development of a deep learning model dedicated to emotion recognition, which successfully achieved a prediction accuracy of 72.3% by incorporating EEG and eye movement data. However, the practical challenges associated with multimodal data collection, particularly among older adults and individuals with neurological disorders, are pronounced. The use of 62 EEG channels, for instance, can be cumbersome and uncomfortable. This challenge has spurred further investigation into the transferability and generalizability of EEG channel selection tailored for emotion recognition tasks across different datasets. Employing a dataset-independent strategy and leveraging Power Spectral Density (PSD) to pinpoint critical EEG channels, our methodology was validated across independent dataset using a Convolutional Neural Network (CNN). Through comprehensive experiments that varied the number of channels and features, our models exhibited classification accuracies of 77.02%, 75.42%, 71.31%, and 64.31% with configurations of 62, 30, 20, and 10 EEG channels, respectively, for four distinct emotion categories. This approach to channel selection not only streamlined the number of EEG channels necessary for accurate emotion prediction but also paved the way for the development of more efficient EEG systems. Such systems are envisioned to facilitate daily emotional monitoring in individuals with neurodegenerative diseases. Lastly, the research also introduced a deep learning model capable of predicting subjective emotional intensities, which achieved an F1-Score of 65.2% in classifying between high and low emotional intensities. This result underscores the significant impact of the subjectivity of emotions on the efficacy of emotion recognition technologies.
Manejo do fogo na pecuária pantaneira: percepções e oportunidades para sua gestão sustentável no bioma
Authors: Labão Catapani Mariana , Ruttul Aguirra Isadora , Accetturi Szukala Araujo Flávia , Moss Andrew , Massocato Gabriel , Oliveira Bruna , Jean Desbiez Arnaud Léonard
Published: December 2024

O Pantanal, maior área úmida tropical do planeta, destaca-se pela predominância da pecuária extensiva como sua principal atividade econômica. O uso do fogo representa ferramenta importante nesse manejo, empregado para renovar pastagens, controlar parasitas e limpar a vegetação. Contudo, entre 2019 e 2020, o bioma enfrentou um aumento alarmante de incêndios, causando danos significativos ao ecossistema, serviços ambientais e tendo substanciais repercussões socioeconômicas. Além da seca, práticas inadequadas de manejo do fogo na pecuária são apontadas como contribuintes para essa situação preocupante. Devido à predominância de propriedades privadas utilizadas para pecuária, compreender as percepções dos pecuaristas sobre o fogo se revela crucial para desenvolver ações de conservação mais efetivas e socialmente justas no ecossistema. Este estudo investigou nuances do uso e manejo do fogo por pecuaristas nas 11 sub-regiões do Pantanal Brasileiro. Entre dezembro de 2021 e março de 2022, foram conduzidas 70 entrevistas semiestruturadas com indivíduos associados à atividade pecuária, de forma presencial e por telefone. Os resultados revelam que, apesar de empregarem o fogo há séculos, atualmente a maior parte dos pecuaristas têm uma visão predominantemente negativa devido aos prejuízos recentes. Pecuaristas tradicionais e recentes diferem em relação à percepção sobre estratégias e momentos considerados apropriados para o uso do fogo. Críticas foram feitas às mudanças recentes no uso da terra, especialmente devido a restrições ambientais, considerando-as facilitadoras do acúmulo de combustível para incêndios. Os entrevistados relataram dúvidas e confusão em relação à legislação que regulamenta o uso do fogo no bioma. Esses resultados apontam a necessidade de ações para aprimorar a compreensão das regulamentações e envolver os pecuaristas no diálogo sobre uma gestão realista do fogo, considerando tanto a conservação da biodiversidade quanto o contexto sociocultural da região.
REMOTE SENSING ENVIRONMENTAL DATA INTEGRATION FOR A QUARRY
Authors:   TECHNICAL UNIVERSITY OF CLUJ NAPOCA, GUSAT DOREL , BUD IOAN ,   TECHNICAL UNIVERSITY OF CLUJ NAPOCA
Published: December 2024

Integrating field models with satellite imagery can provide a comprehensive approach to analyzing environmental changes. This can help validate and calibrate satellite data
This analysis examines an open-pit quarry project in relation to Protected Area metrics. The goal is to minimize both environmental impact and investment costs.
Satellite imagery from the Copernicus program plays a crucial role in assessing land use and environmental changes, enabling a comprehensive evaluation of the quarry's potential effects on surrounding areas. By integrating this data with GIS information, we can effectively visualize and analyze spatial relationships, ensuring that project planning adheres to environmental regulations and minimizes disruptions to local ecosystems.
The analysis is conducted using an ArcGIS Pro license from the Technical University of Cluj-Napoca, specifically through the North University Center of Baia Mare within the Faculty of Engineering. This advanced GIS platform facilitates sophisticated spatial analyses, supporting informed decision-making for sustainable quarry development while safeguarding surrounding areas.
Stateless Minorities: A Case Study of the Rundi and Kenyans of Rwandese Descent
Authors: Wanjiku Jacqueline
Published: December 2024

Kenya is a multi-ethnic country, with over 40 different ethnic groups. Various ethnic groups living in Kenya have existed in constant warfare due to the unequal distribution of resources. However, the situation is worsened by the existence of stateless communities within the country. In Kenya, just like other African countries, there have existed stateless communities such as the Rundi, descendants from Malawi and Kenyans of Rwandese descent. This article examines stateless communities with a case example of the Rundi and Kenyans of Rwandese descent. The article argues that lack of recognition of these communities not only leads to abuse of human rights but also poses a threat to national security. Since their settlement in Kenya, the Rundi and Kenyans of Rwandese descent have yet to gain official recognition by the Kenyan government. This has greatly affected the economic, social and political growth of these communities since their growth is greatly pegged on having official documents that recognize them as Kenyan citizens. The article also highlights the effects of statelessness in the country. The study is guided by the Relative Deprivation theory which posits that inequalities among groups and regions are likely to cause conflict and undermine national cohesion
https://ejurnal.ppsdmmigas.esdm.go.id/sp/index.php/swarapatra/article/view/713
Authors:   Universitas Negeri Yogyakarta, Windarto Danang Alif , Chamdan Muhammad Umar , Yudha Gawiya , Hadipradana Ikhwannuraziz , Santoso Djoko ,   PPSDM Migas
Published: December 2024

Pembangkit listrik tenaga surya (PLTS) adalah jenis pembangkit listrik yang menggunakan energi radiasi matahari yang diubah dengan mengkonversi sel fotovoltaik. Prinsip kerja dari PLTS adalah dapat mengubah cahaya matahari menjadi energi listrik dengan memanfaatkan cahaya matahari atau biasa disebut sel surya atau Photovoltaic (PV). PLTS On-Grid menjadi alternatif penting untuk memenuhi kebutuhan energi listrik. Penelitian ini fokus pada analisis dampak variabilitas cuaca terhadap kinerja PLTS di Laboratorium Listrik dan Mekanik 1 PPSDM MIGAS. Metode penelitian melibatkan pemantauan cuaca harian dan data produksi energi PLTS, dengan analisis statistik untuk mengidentifikasi korelasi, terutama dengan intensitas sinar matahari. Hasilnya diharapkan memberikan wawasan tentang pengaruh cuaca pada kinerja PLTS, mengarah pada peningkatan efisiensi sistem. Selain bermanfaat sebagai studi kasus untuk laboratorium tersebut, penelitian ini juga dapat memberikan panduan umum untuk pengelolaan PLTS On-Grid di lokasi serupa yang rentan terhadap fluktuasi cuaca.
Evaluasi Pengolahan Limbah Cair pada Unit API II PPSDM Migas
Authors:   Universitas Negeri Surabaya, Oktaviani Amartia Cindi , 'Aisy Khulud Rihadatul , Maharani Dina Kartika , Kusuma Rieza Mahendra ,   PPSDM Migas
Published: December 2024

API II merupakan salah satu unit pengolahan limbah terakhir di PPSDM Migas sebelum dialirkan ke Sungai Bengawan Solo. Oleh karena itu, hasil pengolahan limbah API II harus memenuhi baku mutu pada regulasi yang berlaku. Tujuan penelitian ini dilakukan adalah untuk mengetahui kesesuaian kualitas hasil pengolahan limbah serta efektivitas unit API II. Parameter yang digunakan dalam penelitian ini adalah BOD5, COD, Fenol, Ammonia, pH, temperatur, dan minyak lemak. Sampel yang digunakan menggunakan teknik grab sampling pada titik inlet dan outlet di API II. Hasil penelitian ini adalah hasil uji limbah cair pada unit API II PPSDM Migas menunjukkan persentase penurunan parameter BOD5 26%, COD 8.11%, fenol 9.49%, ammonia 42.13%, dan minyak lemak 48.5%. Nilai pH pada inlet sebesar 7.25, sedangkan pada outlet sebesar 7.18. Untuk temperatur limbah cair pada inlet yaitu sebesar 37.5oC, sedangkan pada outlet adalah 35oC. Semua parameter yang diuji telah memenuhi baku mutu.
Analisis Risiko pada Unit Kilang PPSDM Migas dengan Metode HAZID
Authors:   PPSDM Migas, Purwanto Dwi , Karina Imelia ,   Politeknik Negeri Bandung, Panjaitan Jenifer Clara
Published: December 2024

Bahaya merupakan potensi kerusakan atau kecelakaan yang umumnya ada dalam lingkup system proses atau peralatan proses. Dalam industri, Kesehatan dan Keselamatan Kerja (K3) memainkan peran krusial dalam memastikan keselamatan pekerja, keberlanjutan lingkungan, dan efisiensi operasional, terutama dalam konteks operasi yang kompleks dan beragam. Berdasarkan data Kementerian Ketenagakerjaan Republik Indonesia, terdapat 370.747 kasus kecelakaan kerja pada tahun 2023. Untuk memitigasi risiko tersebut, manajemen risiko yang efektif sangat penting. PPSDM Migas merupakan salah satu industri yang mengolah minyak mentah dengan unit utama produksi Crude Distilling Atmospheric Unit (CDU yang memerlukan analisis risiko mendalam. Penelitian ini memanfaatkan metode Hazard Identification (HAZID) untuk mengidentifikasi dan menilai bahaya potensial di unit kilang. Dengan menggunakan metode observasi dan analisis deskriptif kualitatif, penelitian ini mengidentifikasi berbagai aktivitas di unit kilang yang berpotensi menimbulkan risiko. Penilaian risiko dilakukan dengan mengkombinasikan kemungkinan terjadinya risiko (likelihood) dan keparahan dampaknya (severity), menghasilkan kategori risiko dari rendah hingga ekstrem. Hasil penelitian menunjukkan bahwa beberapa aktivitas berisiko tinggi seperti pengoperasian furnace dan proses distilasi, sementara aktivitas lainnya seperti sirkulasi panas dan penerangan kantor kilang memiliki risiko yang lebih rendah. Pengendalian risiko dilakukan dengan berbagai langkah mitigasi seperti penggunaan alat pelindung diri dan prosedur operasional standar untuk mengurangi atau mengeliminasi potensi bahaya.
FPV-ДРОНЫ
Authors: А.Л. Иванов , В.Ю. Морозов , А.А. Соловьев , Р.Ю. Сухарев
Published: December 2024

Рассмотрены особенности конструкций, характеристики и области применения современных FPV-дронов (First Person View). Особо отмечены дроны камикадзе и приведены тактико-технические данные наиболее востребованных моделей в условиях СВО.
Evaluating Three Ways to Handle Drop Points in Address-Based Sampling Frame Surveys
Authors: Looby Charlotte , Lewis Taylor , McMichael Joseph
Published: December 2024

Address-based sampling frames are commonly created from lists derived from the United States Postal Service’s Computerized Delivery Sequence file (CDS), a comprehensive list of addresses in the United States. While most addresses in the CDS represent only one household, some addresses—known as drop points (DPs)—are delivery points for two or more households. The drop point units (DPUs) therein do not have secondary unit designators specified in the CDS, which is a challenge for self-administered surveys because they cannot be contacted specifically. An earlier paper by the authors examined differences between responses of DPUs and nearby non-DPU substitutes in the 2021 Healthy Chicago Survey of sociodemographic characteristics and key health outcomes. This paper is a follow-up analysis comparing the effects of including, excluding, or substituting DPUs on the entire sampling frame, and thus entire study area, to quantify the magnitude of point estimate differences between those methods. No statistically significant differences were found in the distributions of key health outcomes for the three methods. This is true even when focusing on the 11 community areas where more than 30 percent of the homes were DPUs.
Norma sobre el teletrabajo en el ecuador y sus vacíos juridicos: un analisis comparativo
Authors: Almeida Vásquez Oliver Irvi
Published: December 2024

El Artículo 33 de la Constitución de la Republica del Ecuador, consagra que: “El Trabajo es un derecho y un deber social, y un derecho económico, fuente de realización económica. El Estado garantizara a las personas trabajadoras el pleno respeto a su dignidad, una vida decorosa, remuneraciones y retribuciones justas y el desempeño de un trabajo saludable y libremente escogido”.  La ley Orgánica de Apoyo Humanitario agrega el siguiente articulo innumerado a continuación del artículo 16 del Código del Trabajo del Teletrabajo y dice: “El Teletrabajo es una forma de organización laboral, que consiste en el desempeño de actividades remuneradas o prestaciones de servicios utilizado como soporte la tecnología de la información  y la comunicación ara el contacto entre el trabajador y la empresa, sin requerirse la presencia física del trabajador en un sitio específico del trabajo. En esta modalidad el empleador ejercerá labores de control y dirección de forma y el trabajador reportará de la misma manera”.  Se busca a través de esta investigación científica, resolver este problema en que el trabajador esta desprotegido de cualquier riego del trabajo de enfermedad profesional y accidente de trabajo. Concediendo a la clase trabajadora un trato discriminatorio y vulnerando los derechos establecidos en nuestra Constitución Art. 11, numeral 6, que manifiesta: Que todos los principios y derechos son inalienables, irrenunciables, indivisibles, interdependientes y de igual jerarquía.
Vericiguat en Insuficiencia Cardiaca: ¿Un Nuevo Pilar en el Tratamiento Farmacológico? Revisión
Authors: Torres Bogarín Christopher , Duarte Lezama Diego , Pérez Alva Juan Carlos , Lozano Fuantos Francisco , Márquez Marcano Yuliangelys Amantina
Published: December 2024

La activación de la guanilato ciclasa soluble (GCs) y la generación de GMPc son esenciales para el correcto funcionamiento del sistema cardiovascular, ya que desempeñan roles clave en la vasodilatación, la reducción de la fibrosis, la mejora del remodelado cardíaco y la relajación del corazón, sin causar cambios significativos en la hemodinámica. No obstante, en personas con insuficiencia cardíaca, la disminución de la disponibilidad de óxido nítrico reduce la activación de la GCs, lo que lleva a una menor producción de GMPc. Debido a esto, se considera que vericiguat podría ser un tratamiento efectivo para la insuficiencia cardíaca, actuando a través de un mecanismo distinto al de los medicamentos comúnmente utilizados para esta patología. Además, el estudio VICTORIA ha mostrado resultados prometedores, indicando un perfil de seguridad favorable, mejoras en la calidad de vida, reducción de marcadores como los péptidos natriuréticos y la fracción de eyección ventricular izquierda (FEVI), así como una tendencia a reducir la mortalidad y las hospitalizaciones.
Factibilidad Técnica y Económica en el Reciclado de Plástico, un Caso de Estudio
Authors: Hernández Vargas Alma Delia , Aldazaba Jácome Gabriela , Millán Tinoco Victor , Cabrera Ramírez Ariadna
Published: December 2024

En el cuidado del planeta coexiste una responsabilidad compartida por todos, y el reciclaje de plástico juega un papel crucial en este esfuerzo. Esta investigación planteó la determinación de la viabilidad económica y financiera para la  elaboración  de esquineros de plástico  utilizando “basura” obtenida  de reciclado de plástico de envases de alta y baja densidad que pretenden sustituir a los embalajes de cartón que utilizan los exportadores de cítricos. Como punto de partida se aplicó un estudio de mercado y una evaluación económica, con el propósito de implementar  la  idea negocios y determinar la viabilidad financiera de la puesta en marcha de la planta recicladora. La metodología utilizada consistió en la investigación de la demanda potencialmente insatisfecha aplicando encuestas digitales mediante Google Forms a los exportadores de cítricos, posteriormente, se realizó la parte económica, se centró en la inversión inicial, los costos de producción, el punto de equilibrio, los ingresos y  egresos,  reflejados en estados financieros proforma, finalmente, la evaluación económica mostro la viabilidad financiera que se sustentó aplicando indicadores financieros de evaluación.  Los resultados obtenidos proyectan el retorno en 25 meses de la inversión en la adaptación y mejora de las maquinas extrusoras, estableciendo que el proyecto no solo es ecológico, sino también financieramente atractivo.
FABRICAÇÃO DAS LIGAS DE ALUMÍNIO AA3003 E AA3303 A PARTIR DOS PÓS ELEMENTARES DE ALUMÍNIO E DE MANGANÊS ATRAVÉS DE TÉCNICAS DE METALURGIA DO PÓ
Authors: da Silva Junior Moisés Euclides , Pereira Carlos Alberto Cavalcanti Silva , da Silva Clécio Vicente , de Lira Heronilton Mendes , Torquato Jonathan Vinícius Moreira , da Costa José Endreo Baracho , da Silva Lourinaldo Chateaubriand Magalhães , Muniz Max Breno Bezerra , David Thiago Batista , de Araujo Filho Oscar Olimpio
Published: December 2024

Este trabalho tem como principal objetivo a fabricação das ligas de alumínio pertencentes a série AA3XXX, composta pelo sistema Al-Mn, AA3003 e AA3303, via metalurgia do pó (MP). Os pós elementares foram pesados e posteriormente processados por moagem de alta energia (MAE) durante os tempos de 30, 60 e 120 minutos em um moinho vibratório do tipo SPEX. Os pós processados por MAE foram caracterizados através das técnicas de microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva (EDS), difração de raios-X (DRX) e por fim análise de tamanho de partícula (ATP) por difração a laser. Logo após a caracterização dos materiais particulados, os mesmos foram submetidos a uma compactação uniaxial a frio (de simples ação), o compactado verde, foi submetido a duas rotas de consolidação distintas, compactação e sinterização ou pré-compactação e extrusão a quente. Por fim, para caracterização microestrutural do material consolidado, foram utilizadas as técnicas de microscopia ótica (MO) e microscopia eletrônica de varredura (MEV), para a análise da composição química foi aplicada a técnica de espectroscopia de energia dispersiva (EDS) e por fim as amostras foram avaliadas em relação a propriedade mecânica através do ensaio de microdureza Vickers. A caracterização dos pós submetidos a MAE comprovou que com o aumento do tempo de moagem o tamanho mediano de partícula diminuiu, alcançando valores muito próximos do encontrado no alumínio AA100 comercial. Os materiais consolidados por extrusão a quente apresentaram uma microestrutura mais homogênea e quase isenta de porosidade, resultando assim em valores de dureza bem superiores aos obtidos nas amostras sinterizadas e evidenciando a superioridade mecânica dos corpos de prova consolidados por extrusão a quente.
Water Level and Flow Detection System: An IoT-Based Flood Monitoring Application
Authors: Syed Zaifudin Syed Zainul Shafiq , Wan Mahmud Wan Mahani Hafizah , Huong Audrey , Jumadi Nur Anida , Raja Izaham Raja Mohd Aizat , Gan Hong-Seng
Published: December 2024

In Malaysia, floods have become increasingly prevalent, causing significant damage to various aspects of life including infrastructure, property and the economy. The risk to human lives is particularly high in low-lying areas and areas with poor drainage systems. Water contamination during floods can also lead to health issues and the spread of waterborne diseases. The psychological impact of floods should not be underestimated, as individuals may experience a range of emotions such as frustration, sadness, fear and anger. To address these challenges, this study focuses on developing a flood alert system using Internet of Things (IoT) technology. By utilizing ESP32 microcontroller, flow sensor, float sensors, water flow as well as water level can be accurately measured and users can be alerted through the Blynk application. The system ensures accuracy in measuring flow rates, with recorded values ranging from 2.404 L/min to 2.444 L/min. This device can measure water flow and water level which will be generated through ESP32 microcontroller and notifying the user via the Blynk application as for the IoT part. This project has been carried out in indoor experiments to evaluate the efficiency of the float and flow sensors, respectively. Through indoor experiments, it has been demonstrated that this system is capable of effectively monitoring and alerting users to potential flood incidents, helping to safeguard lives and property.
Effect of Storage Temperature of Articular Cartilage on Magnetic Resonance Imaging Greyscale and Biomechanical Properties
Authors: Hashim Hashemi , Abd Latif Mohd Juzaila , Zakaria Mohammad Shukri , Hambali Ruzy Haryati , Arep Hambali , Harun Muhammad Noor , Ho Quang Nguyen , Sha’ban Munirah
Published: December 2024

Storage and preservation of articular cartilage are important in experimental studies. Various storage temperatures were used which led to conflicting results on the biomechanical properties of the cartilage. Therefore, this study aimed to examine the effect of storage temperature on the magnetic resonance imaging (MRI) image and biomechanical properties of articular cartilage. The cartilage specimens were extracted from hip bovine joints which were then tested in fresh condition and in a single freeze-thaw cycle at -20°C to observe the effect of the temperature. Low-field MRI was utilized to obtain the images which were processed to determine the greyscale intensity of the cartilage. Subsequently, indentation tests were conducted on the cartilage and the data was integrated with finite element analysis to characterize the biomechanical properties of permeability and elastic modulus. Based on the results, the elastic modulus of the frozen cartilage decreased to 29%, while the permeability increased to 77% compared to the fresh cartilage. Furthermore, a strong positive correlation (r=0.85) was found between MRI image greyscale and permeability, while a negative moderate correlation (r=-0.51) was obtained between MRI image greyscale and elastic modulus. These findings highlighted the significant effect of storage temperature on the MRI image greyscale and biomechanical properties of cartilage.
U-Turn Shape Effect on Effective Thermal Conductivity of Double Pass Photovoltaic Thermal (PVT) Systems Configuration
Authors: Rajani Ahmad , Mat Said Dalila , Ahmad Noorden Zulkarnain , Ahmad Nasarudin , Akhdiyatullah Ginting Syahrahman , Dwi Atmaja Tinton , Chandrasari Ayu Zahra , Sudibyo Henny , Susatyo Anjar , Darussalam Rudi , Abimanyu Haznan , Fudholi Ahmad
Published: December 2024

This study explores the thermal performance of double-pass photovoltaic thermal (PVT) systems by investigating the influence of turn shape on heat transfer characteristics using computational fluid dynamics (CFD) simulations. The aim is to evaluate various turn shapes, including half-circle, triangle, half-hexagon, half-octagon, and box, to determine their impact on turbulent intensity, effective thermal conductivity, and outlet temperature in PVT systems. The investigation reveals significant variations in heat transfer efficiency among the different turn shapes, with the triangle-shaped turn demonstrating superior performance across multiple parameters. The findings highlight that the triangle-shaped turn exhibits enhanced turbulence generation and heat exchange efficiency compared to other shapes. Specifically, the triangle-shaped turn achieves a maximum turbulent intensity of approximately 70%, surpassing other shapes which achieve around 60%. Moreover, the triangle-shaped turn displays a longer and more substantial area of high heat exchange, resulting in an effective thermal conductivity improvement of up to 20% compared to alternative shapes. Furthermore, the analysis indicates that the triangle-shaped turn exhibits a faster increase in outlet temperature, reaching steady-state conditions within 15 seconds, while other shapes require up to 19 seconds. These results underscore the significance of turn shape in optimizing the thermal efficiency of PVT systems.
Aerodynamic Drag Reduction Using a Conduit in the Ahmed Body
Authors: Agriss Amine , Agouzoul Mohamed , Ettaouil Abdeslem
Published: December 2024

In this study, the focal challenge is reducing drag around the Ahmed body, a critical concern in aerodynamics. The approach involves perforating a rectangular conduit inside the body, redirecting part of the airflow from the front to the rear end to minimize drag. Using Ansys Fluent CFD software and the SST k-w turbulence model, a numerical model for turbulent flow around a 3D body has been developed. Through a series of numerical simulations, variations in the conduit’s position relative to the lowest slanted edge of the body have been explored. At the optimal position with the lowest drag, an examination has been conducted on the narrowing of the conduit outlet dimensions. Results indicate that, with a suitable conduit position and an appropriate exit narrowing, a decrease in drag of up to 3% could be achieved. Ongoing work involves the examination of the conduit’s tilt at the outlet to determine the optimal arrangement for further drag reduction. This research offers practical insights for drag reduction and contributes to the broader field of aerodynamics.
CFD Investigation of Toluene Emission In a Printing Room
Authors: Mohd Khalid Ahmad Amirul Aiman , Jerai Fauziah , Mohd Zainuddin Nor Azira , Mohd Abbas Norliana , Abdul Razak Azli
Published: December 2024

Volatile organic compounds (VOCs) comprise several harmful chemical such as benzene and toluene, that can cause acute and chronic health effects for individuals. One of contributors of VOC are printers, photocopiers, and fax machine that use ink that when it is heated during printing operations will emit VOC. Printing shops heavily operate these devices (machines) and often several of them at the same time and this will cause the VOC level inside the premises to be higher compared to home and offices that have similar equipment. This study estimates the VOC, particularly toluene, concentration, and distribution inside a printing room, by using Computer Fluid Dynamic (CFD) analysis approach software. The software aid in physical modelling of the emission flow based on copiers machine numbers and influence of parameters like concentration levels and anthropometric data. Despite implementing ventilation and at a minimum number of operating copiers, the study reveals that toluene emissions exceed the recommended limit, particularly among females who have higher exposure than males due to height. The quantity of copiers and the positioning influenced the dispersion of toluene in the investigated area.
Konsepsi Kecakapan Umur Debitur Dalam Persyaratan Layanan Pinjaman Online Aplikasi Kredivo
Authors: Jaya Muhamad Ramdan , Batara Surya Daniel , Lumungan Christian Manasye , Angsari Audrey , Andryawan Andryawan
Published: December 2024

Batasan usia minimum dalam menerima pinjaman merupakan sebuah kebijakan penting bagi lembaga keuangan yang bertujuan untuk melindungi baik pemberi pinjaman maupun peminjam. Dengan mempertimbangkan aspek hukum dan sosial, batasan usia minimum identik dengan dianggap dewasanya seseorang. Seseorang pada umumnya dianggap dewasa bila sudah mencapai usia 18 tahun, sebagai titik di mana individu dianggap dewasa secara hukum dan mampu mengambil keputusan finansial. Melalui metode penelitian hukum normatif, artikel ini mengkaji batasan usia minimum yang diterapkan oleh Kredivo dalam syarat menerima pinjaman, serta implikasinya terhadap sebagaimana ketentuan yang termaktub pada Kitab Undang-Undang Hukum Perdata (KUH Perdata) di Indonesia. Kredivo menetapkan bahwa calon peminjam harus berusia minimal 18 tahun untuk dapat mengajukan pinjaman. Namun, menurut KUH Perdata, usia yang belum mencapai 21 tahun dianggap belum dewasa sehingga belum sepenuhnya cakap melakukan tindakan hukum dalam mengikatkan diri dalam kontrak.
Green product of Kusamba Salt: an Alternative of Re-Branding Strategy in Kusamba, Klungkung, Bali
Authors: LAKSMI Putu Ayu Sita , PUTRI Sukmasari Triana Gita , PURNAMAWATI Ida Ayu Putu Santi , DEWI Gusti Ayu Agung Istri Sari , JAMALUDDIN Mohd Raziff Bin , RASHID Wan Edura Wan , SAIHANI Shamsul Bahrin
Published: December 2024

The Bali Government, recognizing the potential of Kusamba salt, has proposed a strategic plan to introduce it worldwide. The governor of Bali, Wayan Koster, suggested enhancing the marketing strategy to make Kusamba salt more appealing. This involves creating attractive packaging and promoting the product's unique qualities, such as its high-quality production methods and the environmental benefits of using natural Salt. Product Differentiation: The proposal emphasizes the need to differentiate Kusamba salt from other table salt products in the market. This could be achieved by highlighting the product's low iodine content, which benefits health and environmental sustainability. Market Integration: The plan also aims to integrate Kusamba salt into global markets. This involves identifying and establishing partnerships with international retailers and distributors interested in natural and health-conscious products. Farmer Empowerment: A significant part of the strategy focuses on empowering the salt farmers of Kusamba village. This includes facilitating the management of BPOM (Badan et al.) licenses and creating opportunities for the farmers to participate in the marketing and distributing their products. Environmental Sustainability: The proposal highlights the importance of promoting Kusamba salt as an environmentally friendly product. This could involve using eco-friendly packaging and promoting the product's sustainable production methods. In summary, the "Green Product of Kusamba’s Salt: An Alternative of Rebranding Strategy" this study aims to elevate the market value of Kusamba salt by optimizing its marketing strategy, differentiating it from other table salt products, integrating it into global markets, empowering the salt farmers, and promoting its environmental sustainability.
The Effect of Financial Distress, Foreign Ownership, and Complexity of Company Operations on The Timeliness of Financial Reporting (Empirical Study on Property and Real Estate Sector Companies Listed on The Indonesia Stock Exchange in 2019-2023)
Authors: AGUSTIN Febri Diany , HAPSARI Dini Wahjoe
Published: December 2024

The purpose of this study is to determine the impact of management complexity, foreign ownership and financial difficulties on the timeliness of financial reporting for real estate companies listed on the Indonesia Stock Exchange (BEI ) from 2019 to 2023. This study uses secondary data. The financial reports and annual reports are available on the official website of IDX. After using the outlier test to reduce the sample size to 22 companies with 110 observation data, the sampling procedure which involved purposive sampling resulted in 41 companies with 205 observation data. The reliability of financial reporting is not affected by financial difficulties; on the contrary, data analysis using a panel data regression approach and Eviews 12 software shows that foreign ownership and complex business operations have a negative impact on the timeliness of financial reporting. This research provides empirical insights into the factors affecting financial reporting timeliness in Indonesia and the managerial implications in developing programs to improve financial reporting timeliness.
Environmental Innovation and Sustainability Practices Manufacturing Companies in Bali Through Government Regulations
Authors: DEWI Kadek Goldina Puteri , KURNIAWAN Komang Adi , PUTRA I Wayan Gde Yogiswara Darma
Published: December 2024

This study aims to examine the influence of environmental innovation and sustainable practices, and the second objective is to examine the influence of environmental innovation and sustainable practices through government regulations as a moderating variable. This study uses a quantitative approach. This model contains variables that are sought from the literature and are relevant to the study. This study surveyed 413 manufacturing companies in Bali Province. Each statement is a five-point item (i.e., 1-5) asking respondents to agree or disagree with the perception, behavior, or experience specified in the statement. Data processing and analysis were carried out using MRA Analysis Statistical Package for the Social Sciences (SPSS) 22.0.
The Effect of Capital Expenditure, Balancing Funds, Regional Original Revenue and E-Government on Local Government Financial Performance
Authors: SUTISMAN Entar , PRASETIANINGRUM Septyana , SUTISNA Entis , NOY Ismail R. , DARMAYANTI Novi , FAHREZA Ellycia Rahma Nurfidya
Published: December 2024

This study examines the effect of capital expenditure, balancing funds, local revenue, and e-government on the financial performance of local governments (Study on local governments in East Java in 2020-2022). The research approach used in this study is quantitative, using secondary data. The population in this study was local governments in East Java for 3 consecutive years for the period 2020-2022. The sampling technique used was purposive sampling, and 114 samples were obtained from 38 districts and cities in East Java. The data analysis techniques used were inner model analysis, outer model analysis, and hypothesis testing. The results of this study indicate that partially, the Capital Expenditure Variable has a negative effect on the financial performance of local governments, the Balancing Fund has a positive effect on the financial performance of local governments, Local Revenue has a positive effect on the financial performance of local governments, and E-Government has a negative effect on the financial performance of local governments.
Search for High-excitation Emission Lines from a Quasar-scale Active Nucleus in Arp 220
Authors: Goldberg Charles E. , Buiten Victorine A. , Rieke George H. , Alonso-Herrero Almudena , Paggi A. , van der Werf Paul , Stone Meredith A. , Morrison Jane E. , Alberts Stacey , Dicken Dan , Wright Gillian
Published: December 2024

The late-stage galaxy merger and prototypical ultraluminous infrared galaxy (ULIRG) Arp 220 is probed using the JWST Mid Infrared Instrument medium-resolution spectrometer to search for multiple diagnostic active galactic nuclei (AGN) emission lines in the low-interstellar-opacity spectral ranges of 5.3–7.9 μm and 12.9–16.0 μm. We detect none of the characteristic high-excitation AGN emission lines. The most diagnostic nondetections are of the [Ne vi] λ 7.652 μm and [Ne v] λ 14.32 μm lines, for which the combined upper limit is ∼10–20 times fainter than the equivalent limit from Spitzer data. We also use X-ray measurements of the reflected Fe Kα line to suggest a relatively low X-ray luminosity. These results suggest that the high obscuration observed along the line of sight to the nuclei of Arp 220 is isotropic and keeps any high-excitation emission from a putative AGN from escaping. An implication is that the observed mid-infrared output of the nuclei is essentially their bolometric luminosity, i.e., no significant additional energy escapes. We utilize this result to show that any embedded AGNs are accreting at no more than ∼5% of the Eddington rate, lower than many theoretical predictions for this stage of ULIRG evolution.
Viscous Transonic Accretion Flows in Kerr Black Hole Geometry
Authors: Bhattacharjee Abhrajit , Chakrabarti Sandip K.
Published: December 2024

We study viscous transonic accretion flows in vertical equilibrium in Kerr geometry. We employ the pseudo-Kerr formalism that accurately describes transonic flows around Kerr black holes and is applicable for modeling observational data. We study the effects of viscosity on the nature of sonic points and the parameter space that allows an accretion flow to possess multiple sonic points. We concentrate on the accretion solutions that can have centrifugal pressure supported shock waves and find that the shocks are weaker and are located farther from the black hole as the viscosity is enhanced. Moreover, if the viscosity is greater than a critical value, shocks do not form and the accretion flow can pass only through the inner sonic point close to the black hole and remains subsonic and Keplerian throughout the accretion disk. Since the resonance oscillation frequencies of the shock waves provide a measure of the observed quasiperiodic oscillation (QPO) frequencies, and since the location of shock waves depend on the spin of a black hole, it is clear that the QPO frequencies must depend on the spin of black hole as well. Our pseudo-Kerr approach makes it easier to compute spectra from an accretion flow with viscous dissipation and radiative cooling around a spinning black hole.
Volatile Element Depletion of Carbonaceous Chondrites—Insights from Mass-dependent Zinc, Cadmium, and Tellurium Isotope Variations
Authors: Morton Elin M. , Pickard Harvey , Wombacher Frank , Huang Yihang , Palk Emeliana , Martins Rayssa , Kuthning Sven , Schönbächler Maria , Rehkämper Mark
Published: December 2024

The origin of volatile depletion in the solar system remains a topic of intense debate. To further inform our understanding of the mechanisms involved, this study characterized the mass-dependent Zn, Cd, and Te isotope compositions and concentrations of a comprehensive suite of carbonaceous chondrites (CCs). In accord with previous studies, Zn and Te display covariations between light isotope enrichments and elemental depletions. Observed here for the first time, Cd shows a similar trend. These correlations are consistent with the interpretation that the primary volatile element budgets of CCs were established by mixing of a volatile-rich CI-like matrix and a volatile-depleted non-matrix endmember (NME) in the solar nebula. All three elements display minor isotopic variations in CI and CM chondrites, as a consequence of aqueous alteration at low temperatures. In contrast, Cd and Te isotope compositions and concentrations are highly variable in CV and CO (Cd) and CK chondrites (Te). This reflects mobilization of the elements during thermal metamorphism at distinct redox conditions. The data of this study show that the NME has Zn, Cd, and Te concentrations that are depleted to an identical level of 0.12 ± 0.03 × CI chondrites, and it is characterized by mass-dependent isotope compositions for all three elements that are fractionated to light isotope values relative to CIs by a similar extent. In conjunction with literature data, this suggests that the concentrations and isotope compositions of NME volatiles record the same depletion processes, and that the NME volatile inventory is likely hosted predominantly in chondrules.
Searching for Radio Late-type Dwarf Stars in the GLEAM-X DR1 Catalog
Authors: Huang 黄 Qichen 启宸 , Jiang 姜 Biwei 碧沩 , Zhang 张 Zehao 泽浩 , Zijlstra Albert
Published: December 2024

We have developed a new method of multiwavelength data combination for the search of late-type radio dwarfs, and have put it into practice using GLEAM-X DR1 data. The initial sample is selected by cross-matching the Gaia/DR3 objects with the probability of being a star no less than 99%, and removing the extragalactic objects assigned by the SIMBAD database. The late-type dwarf stars are judged according to their location in the (BP − RP)0/M
G color–magnitude diagram and in the (J − H)0/(K − W1)0 near-infrared color–color diagram. Furthermore, stellar activity is searched by ultraviolet excess in the GALEX/NUV band and the Rossby number in the TESS light curves. In total, 12 stars are found to be late-type dwarf stars associated with radio source, which consists of five stars with UV excess and seven stars with a Rossby number less than 0.13. Three of these 12 stars are previously studied to be associated with radio objects. All these 12 stars are considered to be reliable counterparts of radio sources.
zoomies: A Tool to Infer Stellar Age from Vertical Action in Gaia Data
Authors: Sagear Sheila , Price-Whelan Adrian M. , Ballard Sarah , Lu Yuxi (Lucy) , Angus Ruth , Hogg David W.
Published: December 2024

Stellar age measurements are fundamental to understanding a wide range of astronomical processes, including Galactic dynamics, stellar evolution, and planetary system formation. However, extracting age information from main-sequence stars is complicated, with techniques often relying on age proxies in the absence of direct measurements. The Gaia data releases have enabled detailed studies of the dynamical properties of stars within the Milky Way, offering new opportunities to understand the relationship between stellar age and dynamics. In this study, we leverage high-precision astrometric data from Gaia DR3 to construct a stellar age prediction model based only on stellar dynamical properties, namely the vertical action. We calibrate two distinct, hierarchical stellar age–vertical action relations, first employing asteroseismic ages for red-giant-branch stars, then isochrone ages for main-sequence turn-off stars. We describe a framework called zoomies based on this calibration, by which we can infer ages for any star given its vertical action. This tool is open-source and intended for community use. We compare dynamical age estimates from zoomies with age measurements from open clusters and asteroseismology. We use zoomies to generate and compare dynamical age estimates for stars from the Kepler, K2, and TESS exoplanet transit surveys. While dynamical age relations are associated with large uncertainty, they are generally mass independent and depend on homogeneously measured astrometric data. These age predictions are uniquely useful for large-scale demographic investigations, especially in disentangling the relationship between planet occurrence, metallicity, and age for low-mass stars.
Multiphase Gas Nature in the Sub-parsec Region of the Active Galactic Nuclei. III. Eddington Ratio Dependence on the Structures of Dusty and Dust-free Outflows
Authors: Kudoh Yuki , Wada Keiichi , Kawakatu Nozomu , Nomura Mariko
Published: December 2024

We investigated the influence of the Eddington ratio on sub-parsec-scale outflows in active galactic nuclei (AGNs) with supermassive black holes (SMBHs) masses of 107
M
⊙ using two-dimensional radiation hydrodynamics simulations. When the range of the Eddington ratio is γ
Edd > 10−3, the radiation force exceeds the gas pressure, leading to stronger outflows and larger dust sublimation radius. Although the sub-parsec-scale outflows are a time-dependent phenomenon, our simulations demonstrated that the radial distributions can be well explained by the steady solutions of the spherically symmetric stellar winds. The dynamic structure of sub-parsec-scale outflows is influenced by the dust sublimation radius and the critical radii determined by the dynamical equilibrium condition. Although significantly affecting the outflow velocity, the Eddington ratio exerts minimal effects on temperature and number density distribution. Furthermore, our analytical solutions highlight the importance of the dust sublimation scale as a crucial determinant of terminal velocity and column density in dusty outflows. Through comparisons of our numerical model with the obscuring fraction observed in nearby AGNs, we reveal insights into the Eddington ratio dependence and the tendency toward the large obscuring fraction of the dusty and dust-free gases. The analytical solutions are expected to facilitate an understanding of the dynamical structure and radiation structures along the line of sight and their viewing angles from observations of ionized outflows.