bluuebunny/crossref_metadata_2025 huggingface dataset:
Hubungan Karakteristik Visual dan Fungsi Restoratif Kawasan Stadion Kanjuruhan Berdasarkan Persepsi Pengunjung
Authors: Oktania Salsabila Agfa , Setyono Deni Agus , Rukmi Wara Indira
Published: September 2024

Kecamatan Kepanjen sebagai pusat pemerintahan skala kabupaten dengan berbagai kegiatan penunjang di dalamnya menimbulkan pergerakan lokal maupun pergerakan dari wilayah sekitar. Tingginya aktivitas serta mobilitas tersebut, meningkatkan intensitas masyarakat untuk mengalami kepenatan yang mampu membangkitkan perasaan stres. Keberadaan Kawasan Stadion Kanjuruhan sebagai ruang publik yang mampu diakses dengan mudah oleh publik dapat menjadi salah satu sarana restoratif bagi para pengunjung dengan tujuan untuk melepaskan kejenuhan dari aktivitas keseharian yang dilakukan. Pembangunan ruang publik dengan pemilihan komponen-komponen visual dapat memberikan efek peningkatan kesejahteraan psikologis manusia yang dapat meningkatkan kesehatan mental seseorang. Oleh karena itu, diperkirakan ada keterkaitan antara karakteristik visual dengan fungsi restoratif ruang publik Kawasan Stadion Kanjuruhan. Penelitian ini merupakan penelitian kuantitatif, untuk mengetahui adanya hubungan tersebut. Teknik analisis yang dilakukan adalah uji Chi-square dan uji Kendall’s Tau untuk mengetahui tingkat hubungan antar-subvariabel. Berdasarkan hasil penelitian, dapat diketahui bahwa terdapat hubungan antara karakteristik visual ruang publik Kawasan Stadion Kanjuruhan dengan fungsi restoratif yang dirasakan oleh pengunjung yang didefinisikan berdasarkan hubungan antar-subvariabel yang signifikan. Subvariabel karakteristik visual yang memiliki tingkat hubungan “cukup” dengan fungsi restoratif antara lain adalah kealamian, keterbukaan, keteraturan, dan signifikansi historis.
面向印尼学生的“听说+读写”高效教学模式探析
Authors: Deling Ren
Published: September 2024

In response to the actual needs of Indonesian students in learning Chinese,Sekolah Tinggi Bahasa Harapan Bersama in Pontianak and the College of Chinese Language and Culture of Jinan University have cooperated to open an efficient teaching model of "listening, speaking + reading and writing", in order to quickly improve students' Chinese use ability in a short period of time. This study intends to compare the efficient model with the traditional Indonesian undergraduate teaching model from the aspects of curriculum setting, teaching content, teaching methods and teaching strategies, so as to better meet the needs of different learners. In terms of curriculum setting, the efficient mode adopts the concept of "small steps and fast walking", and the course type is streamlined into two categories: "listening and speaking" and "reading and writing". In terms of teaching content, the study aims to analyze the differences in the content learned by comparing the number of new words taught in one semester and the difficulty level of the two modes. In terms of teaching methods and strategies, the teaching model of "listening, speaking + reading and writing" proposes teaching strategies including "language 'use' for middle school", 'increasing input' and 'running in small steps'". On the basis of teaching practice, this paper evaluates the practical effect of the effective teaching mode of "listening, speaking + reading and writing" for Indonesian students from the aspects of Chinese proficiency test scores, daily homework and activity performance, and then reflects on and improves the teaching practice.
三发市华人冬至节传统习俗概况
Authors: Candy Candy , Shiela Shiela
Published: September 2024

The title of this study is “Overview of Traditional Customs of Chinese Winter Solstice Festival in Sambas City”. The winter solstice is a very important solar term in the lunar calendar, it is the 22nd of the 24 solar terms. The winter solstice is also a traditional festival. The Winter Solstice is generally celebrated on December 21st or 22nd of the lunar calendar. The winter solstice was once called “eating glunious rice balls” by Chinese Indonesians. The purpose of the research is to understand the customs and significance of the Sambas city Winter Solstice Festival and the differences between Sambas and Chinese Winter Solstice Festivals. The author chooses Sambas Chinese as the research object. The data collection method used in this article is interviews. It can be seen from the interview results that the Sambas Chinese still celebrate the Winter Solstice Festival, but many people do not understand the meaning, significance and customs of the Winter Solstice Festival. With the development of the times, many traditional customs have gradually changed, and some customs have even slowy disappeared.
Student Perceptions of Desired Learning Media Technology Development
Authors: Andayani  , Prabowo Suryo , Gafur Abd , Situmorang Robinson , Setiawan Bramianto
Published: September 2024

This study aimed to explore the perceptions of undergraduate students on suitable learning media for website development. A qualitative method with a case study type was used in this research. Fifty undergraduate students from the Educational Technology department participated. A questionnaire was used as the instrument to gather data on the necessary learning media. Data analysis was performed using NVivo 12 software, and results were presented as percentages based on two indicators: technology accessibility and learning materials. The study’s results and discussion highlighted two crucial factors influencing the choice of learning media in website development education. First, technology accessibility factors, encompass technological support and interaction. Second, learning material factors, including the type and complexity of the material. These findings offer valuable insights for developing more effective learning media in web development courses by taking these key factors into account.
Outdoor Learning Methods on the Ability to Write Free Poetry in Hankuk University of Foreign Studies Malay-Indonesian Study Program Students South Korea
Authors: Tundreng Syarifuddin , Sulaeman Agus , Hoon Kim Dong , Putra Eko , Rofi’i Agus
Published: September 2024

This study aims to determine the effect of using outdoor learning methods on the ability to write free poetry in Audio Visual A1 and A2 classes of Malay-Indonesian. The method used is an experimental method of the Quasi Experimental type using two classes, namely the experimental class of 37 students which given treatment in the form of outdoor learning methods and a control class of 35 students which was not given treatment as a comparison class. The data collection technique used a poetry writing essay test and a questionnaire to find out students' responses to the outdoor learning method. Based on the results of hypothesis testing data analysis using the t test at a significant level of 0.05, a T count of 2.592 and a T table of 1.997 are obtained. Because T count is greater than T table, namely 2.592 > 1.997. It can be concluded that accept H1, reject H0, thus it can be said that there is an influence on the use of outdoor learning methods. Based on the results of hypothesis testing data analysis using the t test at a significant level of 0.05, a T count of 2.592 and a T table of 1.997 are obtained. Because T count is greater than T table, namely 2.592 > 1.997. It can be concluded that accept H1, reject H0, thus it can be said that there is an influence on the use of outdoor learning methods.the ability to write free poetry for students of the Malay-Indonesian study program Hankuk University of Foreign Studies South Korea.
Developing Guided Reading Guidebook through Leveled Books to Improve Reading Skills of Grade 1 Students
Authors: Alfiani Shahriza Wahyu , Sismulyasih SB Nugraheti
Published: September 2024

Guidebooks for guided reading methods through tiered books have not been found in learning reading skills. Still, based on several previous studies, the impact of using guided reading methods and tiered book media is very effective in reading skills. Therefore, this study aims to develop a guidebook product for guided reading methods through tiered books to improve the reading skills of grade 1 elementary school students. This study used a Research and Development (R&D) approach using the 4D development model, focusing on the 3 stages of 4D development namely define, design, and develop. The research subjects comprised 1 grade 1 teacher and 32 grade-1 students at SD Negeri Sarirejo 1, Demak. The data collection technique used a questionnaire which was then analyzed and described to provide an overview of the feasibility and effectiveness of the guidebook. The product feasibility test was analyzed using percentages and the product effectiveness test was analyzed using the Wilcoxon Signed Rank Test, t-test, and N-Gain test. The results of the study explained that the guidebook for guided reading methods through leveled books was said to be feasible with a value of 92.4% from media experts, 92% from material experts, and 89.7% from practitioners. The results also provide an effectiveness value through a t-test with the value of the Ha t-test analysis accepted and the N-Gain obtained is 0.63. Thus, it can be explained simply that the guidebook for guided reading methods using tiered books is feasible and effective to be used by teachers to support Indonesian language learning, especially in reading skills.
Implementation Of The Talking Stick Learning Model Used By Koper Sebeni Media
Authors: Anjarsari Iis , Fayeldi Trija , Pranyata Yuniar Ika Putri
Published: September 2024

The use of media can increase clarity and interest in the learning process, increase learning motivation, and make it easier to understand the material. The aim of this research is to determine the talking stick learning model that can improve student learning outcomes in comparative material in class VII Pagak Islamic Middle School with the help of the Koper Sebeni media. This classroom action research was carried out using qualitative methodology. The steps in the process are preparation, action, observation, and reflection. The flow model is used to analyze the data obtained, which includes data reduction, data presentation, and drawing conclusions. The research results showed that from cycle 1 to cycle 2 student learning outcomes increased. The percentage of completion of the final exams for cycles 1 and 2 was 83.33% and 91.67% respectively, which shows an increase in the proportion of students by 8.33%. Thus it can be said that the use of the Koper Sebeni media combined with the talk stick learning strategy can improve student learning outcomes. So that most students have the opportunity to answer questions, future researchers must spend sufficient time on the talking stick learning model.
The Military and planning for lithium-ion battery recycling4.78 MB)
Authors: Young Allison , Davidson Susannah , Wilson Emily , Begay Brenton , Urban Angela
Published: September 2024

Understanding the military challenges related to lithium-ion battery disposal and learning about current and future trends in recycling efforts can inform safer and less environmentally destructive end-of-life solutions. Established lead-acid battery recycling methods were compared to the still-evolving lithium-ion battery recycling processes. Executive Order (EO) 13817, EO 13953, and EO 14017 have prioritized the identification of critical minerals, including minerals necessary for lithium-ion battery production, and the need to strengthen supply chains as vital to national security. To support this national security effort, the military may be able to contribute to the domestic supply through employing efficient recycling practices and encouraging industry to move towards standardization. Evolving recycling practices, including efforts to eliminate hazards in spent lithium-ion batteries, may be able to help the military dispose of these items more safely and cost-effectively, especially in contingency locations.
Exploring the Multifaceted Nature of Occupational Stress Among Nurses: A Systematic Review
Authors:   Universiti Malaya, Kuala Lumpur, Murali Sundram Bala , Kumareswaran Vallasamy Suriya ,   Johor State Health Department, Johor Bahru, Muhadi Umairah ,   Johor State Health Department, Johor Bahru
Published: September 2024

This systematic review examined occupational stress among nurses, its multifaceted nature, and its significant impact on healthcare delivery and nurse well-being globally. This study identified various stressors, including intrinsic job factors, organizational structure, role expectations, interpersonal relationships, and career development. Using the Cooper and Marshall stress model, a thorough literature search was conducted across databases like ISI Web of Knowledge, PubMed, Scopus, Ovid Medline, and Google Scholar, focusing on publications from 2010 to 2023. This rigorous approach included diverse research methodologies, emphasizing studies measuring outcomes related to occupational stress and mental health among nurses. A total of 10 studies met the inclusion criteria, highlighting stressors such as workload, job demand, job insecurity, and less reward, categorized into five primary sources. The review revealed that occupational stress in nursing is a global issue, leading to adverse outcomes like burnout, decreased job satisfaction, and increased turnover. The discussion emphasized the need for a holistic approach to stress management, advocating for supportive work environments, adequate staffing, and professional development opportunities. In conclusion, strategic interventions are crucial for improving mental health, job satisfaction, and healthcare quality, necessitating collaborative efforts from healthcare leaders, policymakers, and practitioners.
Exploring the Implementation of Safety Resilience Assessment in Industries: A Systematic Literature Review
Authors:   Universitas Indonesia, Depok, Wirawan Mufti , Lestari Fatma ,   Universitas Indonesia, Depok, Djunaidi Zulkifli ,   Universitas Indonesia, Depok, Hafia Azka ,   Universitas Indonesia, Depok, Mohamad Khaliwa Agra ,   Universitas Indonesia, Depok, Schehan Al Azhar Muhammad ,   Universitas Indonesia, Depok
Published: September 2024

Safety Resilience discusses how a work process can run properly not only aims at preventing adverse events, but also increasing work productivity and effectiveness by increasing resilience. The concept of resilience has been widely suggested as safety management due to its ability to support organizations to continue operating even when facing unexpected demands or scale disruptions by improving their day-to-day performance. This study used a systematic literature review to explore the implementation of safety resilience in various industries. The results showed that 50% of articles used the Resilience Assessment Grid instrument to measure safety resilience in the workplace. In brief, increased safety resilience positively improves work performance and organizational safety.
Spatial Durbin Model on the Utilization of Delivery at Health Facilities: A 2017 Indonesian Demographic and Health Survey Analysis Authors
Authors:   Universitas Indonesia, Depok, Sri Wahyuni Indah , Gustina Ira ,   Universitas Indonesia, Depok, Rahmaniati Makful Martya ,   Universitas Indonesia, Depok, Eryando Tris
Published: September 2024

The utilization of delivery at health facilities is a major intervention in reducing 16 to 33% of deaths. This study aimed to determine the model of utilization of delivery at health facilities in Indonesia in 2017 and its influential factors. This study used secondary data from the 2017 Indonesian Demographic and Health Survey using a Spatial Durbin Model (SDM) approach. The population was mothers aged 15 – 49 years, spread across 34 provinces of Indonesia, and had 15,321 samples. The results showed that the Moran’s I value was positive (0.146) and significant at p-value = 0.007, indicating clustered regions with similar characteristics. The SDM modeling estimation results (R2 = 91.61%) presented those dependent and independent variables that influenced the utilization of delivery at health facilities and its influential factors. The significant and most dominant direct factor that influenced the utilization of delivery at health facilities was pregnancy visits, while the most dominant indirect factor was socioeconomic status. Therefore, further policy planning is expected to be based on regional specificities, and effective intervention programs should be designed based on these factors.
COMBUSTION EXHAUST GAS ANALYSIS: DEVELOPMENT OF AN EXCEL WORKBOOK
Authors: Cordeiro Vaz Gilberto , M. Oliveira A. Virgílio , Duarte Carvalho Anabela
Published: September 2024

Combustion systems are still widely used in HVAC systems. Combustion of common fuels generates pollutants that contaminate the environment and also contribute to global warming. These environmental concerns and the search for more efficient systems require combustion systems to be monitored to optimize their operating conditions. One of the most used tools to achieve those goals is through the Ostwald diagram characteristic of the fuel being burned. The purpose of the present contribution is to introduce an Excel workbook that represents a friendly easy to use tool that enables the calculation of combustion products for fuel mixtures and the respective automatic Ostwald diagram drawing. This tool was developed for didactic purposes, but its use might be looked at in a wider perspective, such as industrial applications. The workbook includes several worksheets, all linked to each other. One worksheet was developed to enable the consultation of the Ostwald diagram. Entering values measured with a combustion gas analyzer, the user obtains immediately the other combustion parameters, which allows the evaluation of the real combustion conditions and the implementation of changes in the burning system in order to optimize the combustion process.
Analytical modelling of an indirect evaporative cooler based on the Maisotsenko cycle for HVAC applications
Authors: Ruiz Ramírez Javier , Gascó Arranz Clara , Opolot Michael , Lee Sangkyoung , Zhao Chunrong
Published: September 2024

Highly-efficient evaporative cooling systems can significantly reduce the energy use in buildings, thereby contributing to meet Europe’s climate commitments, including building decarbonisation by 2050. The Maisotsenko Cycle is an indirect, multi-stage type of evaporative cooling which can be used in different air-conditioning applications. The main objective of this study is to develop an analytical model of an indirect evaporative cooler based on the Maisotsenko cycle for HVAC applications. The conservation equations governing the heat and mass transfer processes occurring in the indirect evaporative cooler were solved by means of numerical methods, and the results provided by the model were validated using experimental data reported in the literature (differences lower than 2%). Finally, a parametric study was conducted where the influence of various operational and environmental variables on the system's performance were numerically analysed.
SELECCIÓN DE UN ADITIVO PARA H2O/LiBr EN SISTEMAS DE REFRIGERACIÓN Y BOMBAS DE CALOR POR ABSORCIÓN EN BASE A LA DETERMINACIÓN CUANTITATIVA DE LA HIDRATACIÓN DEL LiBr
Authors: Salavera Daniel , Latorre-Arca David , Ahmed Hussain T. , Soledad Larrechi María , Coronas Alberto
Published: September 2024

Se presenta la estrategia seguida para la selección de un líquido iónico, y su concentración, para actuar como aditivo del par de trabajo agua/bromuro de litio en sistemas de refrigeración y bombas de calor por absorción. Este ha de mejorar la solubilidad del LiBr en agua para ampliar el intervalo de trabajo de estos sistemas y las aplicaciones. Esta estrategia se basa en el análisis de la cantidad de agua libre. Como resultado principal, el cloruro de 1,3-dimetilimidazolio con una composición del 6 % en masa de absorbente mejora la solubilidad la solubilidad de la mezcla, sin afectar negativamente a la capacidad de absorción
Modelado y simulación de un sistema de enfriamiento solar continuo mediante refrigeración por absorción de simple efecto
Authors: Zacarías Santiago Alejandro , Sánchez Fuentes Josué Gustavo , García Flores Alberto Iván , Barrera García Esteban Eduardo , Romage Guerlin , Jiménez Castillo Cuauhtémoc , Ramos López Gonzalo Alonso , Jiménez Bernal José Alfredo , Carvajal Mariscal Ignacio
Published: September 2024

En este artículo se presenta el modelado y simulación de un sistema de aire acondicionado continuo mediante refrigeración por absorción de simple efecto, alimentado por energía solar térmica a baja temperatura (85°C) mediante colectores solares de placa plana, para ser empleado en zonas tropicales. El modelado se realiza principalmente mediante balances de energía y de masa en cada componente del sistema. Para una potencia de enfriamiento de 3.517 kW, el calor requerido por el generador del sistema de refrigeración por absorción, fue de 4.8 kW. En tanto que el área del colector requerido mayor fue de 16 m2 aproximadamente.
CASEUS – COMBINED USE OF RENEWABLE ENERGY SOURCES TOIMPROVE ENERGY EFFICIENCY IN REFRIGERATED CHEESERIPENING CHAMBERS
Authors: Miranda Garcia João Nuno Pinto , Teixeira Tiago , Calvo Francisco , Dias João
Published: September 2024

This article focuses on the integrated use of various forms of renewable energy,including wind, solar thermal, and photovoltaic, combined with Phase Change Materials(PCMs), aiming to optimize energy consumption and reduce CO2 emissions in the production oftraditional ewe’s cheese, with particular emphasis on the cooling system of the ripening chamber.Given the increasing global concern about climate change, with the European Union, it becomesimperative to seek sustainable solutions. The current volatility of fossil fuel prices in theinternational market reinforces the urgency of shifting the energy consumption paradigm,prioritizing the transition to renewable sources. This study, conducted as part of the CASEUSproject, encompasses several significant phases, including analyzing the most influentialvariables in temperature stability and energy consumption during pasteurization, coagulation,and ripening chamber stages; evaluating energy performance; optimizing the combined use ofelectrical (photovoltaic and wind) and thermal (solar hot water and biomass) energy sources andimplementing Phase Change Materials (PCM) to regulate the ripening chamber temperature andoptimize thermal energy flows through thermal energy storage
ANÁLISIS DE LOS SISTEMAS DE CONTROL EN CALEFACCIÓN CON CALDERA O BOMBA DE CALOR Y RADIADORES
Authors: Fernández Hernández Francisco , Atienza Márquez Antonio , Peña Suárez José Miguel , Bandera Cantalejo Juan Antonio , Cuesta de la Mata Ana Belén
Published: September 2024

La nueva Directiva de Eficiencia Energética en Edificios acuerda que los sistemas de calefacción basados en combustibles fósiles sean eliminados de la Unión Europea en el 2040. En el actual parque de viviendas, un gran porcentaje tiene un nivel de aislamiento bajo y es habitual un sistema de calefacción con radiadores de alta temperatura y producción mediante caldera. Los incentivos económicos gubernamentales cubren la sustitución del sistema de producción, con una apuesta por la bomba de calor, pero no de las unidades terminales, lo que está frenando la esperada rehabilitación de las instalaciones de calefacción en Europa. Por ello, el objetivo de este estudio es analizar la viabilidad técnico-económica de la introducción de la bomba de calor en un abanico de escenarios diferentes (nivel de aislamiento, tipo de clima, etc.), donde el sistema de control puede jugar un papel fundamental para conseguir la mayor eficiencia y garantizar el confort térmico de los usuarios.
El estudio presenta el modelado de las estrategias de control multi-zona propuestas por la compañía Airzone para una instalación con caldera o bomba de calor y radiadores de alta temperatura, mediante Trnsys18. Los resultados analizan la influencia del tipo de envolvente térmica del edificio, diferentes escenarios de control y la zona climática. Se comparan los resultados del ahorro de energía, confort térmico y viabilidad económica.
EXPERIMENTAL ANALYSIS OF THE INFLUENCE OF FAN SPEED ON FROST GENERATION AND ITS IMPACT ON A HEAT PUMP
Authors: Alarcón Gallén David , Navarro Peris Emilio
Published: September 2024

The phenomenon of frost on the heat exchanger surfaces penalizes the performance of the heat pump, one of the operating parameters that influences the evaporation temperature, this is transferred to the formation of frost, and its impact is the amount of air passing through the evaporator, in that sense, an air-water heat pump has been experimented at different fan speeds and environmental conditions inside a climatic chamber. The results allow to obtain different parameters to characterize the frost formation process and to make an effective comparison between them. The lower the fan speed, the lower the air flow rate, the lower the heating time, and the higher the number of defrost cycles required for the same environmental conditions. In this way, some correlations could be developed to predict how the frosting process is affected by the fan speed in more conditions that are not tested. The aim is to determine to what level frost formation can be suppressed by achieving different fan speeds whether it is technically and economically feasible and what implications imposes on the heat pump performance.
REFRIGERANTES DE BAJO PCA PARA LA SUSTITUCIÓN DEL R-449A EN UN SISTEMA DE REFRIGERACIÓN COMERCIAL
Authors: Giménez Prades Pau , Navarro Esbrí Joaquín , Udroiu Cosmin-Mihai , Mota Babiloni Adrián
Published: September 2024

Las demandas actuales del sector de la refrigeración se centran en el uso de refrigerantes con un bajo potencial de calentamiento atmosférico (PCA) en instalaciones de compresión de vapor. Los principales objetivos de este estudio surgen de estas necesidades. En él se proponen y estudian refrigerantes alternativos con un PCA inferior a 150 en un sistema de refrigeración comercial que opera con el R-449A. En primer lugar, se hace una búsqueda de nuevas mezclas de refrigerantes a partir de la combinación binaria y ternaria de refrigerantes puros. De esta búsqueda se obtiene el mejor refrigerante con clasificación de seguridad A1, A2L y A2/A3, para los sistemas de media temperatura (MT) y de baja temperatura (BT). Después de su determinación, se simula la operación del supermercado con estos refrigerantes. Finalmente, se realiza una evaluación medioambiental. La mayor eficiencia energética se obtiene con la mezcla R-152a/R-1243zf para el sistema MT y la mezcla R-290/R-1270 para el sistema BT. Sin embargo, la mayor reducción de las emisiones de gases de efecto invernadero (GEI) se logra mediante el R-290, con una reducción del 73,09% con respecto al sistema de referencia.
EFECTO DE LA CONGELACIÓN POR ALTAS PRESIONES EN LA VIDA ÚTIL DE LOS ALIMENTOS
Authors: Escobar Alba , Urbeltz Uxue , Arroqui Cristina , Vírseda Paloma
Published: September 2024

Mediante la utilización de altas presiones se pretende asegurar que el proceso de congelación del alimento tenga lugar cuando la temperatura en todas las partes del producto asegure una temperatura por debajo del punto de congelación. Para ello el producto será sometido a una presión de 2000 bares mientras se enfría mediante agua glicolada hasta conseguir que, la temperatura en el centro del producto esté muy por debajo de su punto de congelación. Llegado a ese punto la presión será eliminada para conseguir una congelación flash que garantice la generación de numerosos núcleos que generen cristales de pequeño tamaño. El producto, carne de cerdo, así congelado será comparado en cuanto a color, pH, textura y vida útil con la misma carne congelada de manera tradicional. Los resultados han mostrado que la ruptura tisular medida a través de los exudados se minimiza mediante la congelación por diferencia de presión, lo que se ve reflejado en un aumento de la calidad del producto durante su almacenamiento.
Sistema integral para cubrir demandas térmicas de edificios pasivos
Authors: Moià Pol Andreu
Published: September 2024

Actualmente en España las nuevas viviendas no pueden consumir más de 30 kWh/m² de energía primaria no renovable, con un diseño pasivo, energías renovables y sistemas eficientes, donde la bomba de calor de baja potencia es el sistema más utilizado para cubrir el 60% de la demanda térmica anual (HVAC y Agua Caliente Sanitaria). En este artículo se propone un diseño con una bomba de calor Agua-Agua para cubrir las demandas de refrigeración con el frío residual que se genera para producir el ACS que supone un 16%, similar al consumo de los frigoríficos. Para el diseño casas pasivas y edificios de consumo de energía casi nulo, sería importante que los fabricantes aprovechen el calor residual de los frigoríficos para ACS. Se presenta un caso real con clima mediterráneo de una vivienda con una despensa refrigerada con el frío residual para el ACS, reduciendo más de un 14% el consumo energético anual. Este modelo puede servir para las futuras viviendas o nuevos equipos. Las bombas de calor combinadas con energía fotovoltaica podrán cubrir los consumos térmicos de una vivienda, incluyendo la refrigeración de alimentos
IMPLEMENTACIÓN Y CALIBRACIÓN DE UN MODELO DE ESTIMACIÓN DEL COP BASADO EN RESULTADOS EXPERIMENTALES
Authors: Bujedo Nieto Luis Angel , Andrés Chicote Manuel , Samaniego Muñoz Juan Jesús , Belda González Alberto , Lozano Gabarre Ismael
Published: September 2024

Los sistemas de bomba de calor (BC) agua-agua está aumentado debido a la extensión de los sistemas de redes de calor de distrito y a la cada vez mayor necesidad de penetración de sistemas renovables en la generación térmica, aprovechando sistemas geotérmicos para la climatización residencial facilitando la evolución hacia nuevos escenarios de participación e implicación en el mercado energético.
El presente trabajo muestra los resultados obtenidos de la implementación y calibración de un modelo de estimación del COP de una BC empleando para ello datos obtenidos del ensayo de la misma en el banco de ensayos del que dispone CARTIF. El modelo parte del método de estimación generalizado presentado por Jensen, cuyos parámetros dependientes de las características constructivas de la máquina y del refrigerante empleado se ajustan usando datos experimentales de la BC operando en diversas condiciones de temperatura de sus focos de intercambio energético. Para realizar este proceso de ajuste, se realiza una optimización del valor de los parámetros para tratar de minimizar la media del error relativo de todos los ensayos obtenido. Tras el proceso de calibración, se obtiene una estimación del COP basada en las condiciones de operación que presenta un error medio menor al 10%.
Modelación y simulación de un refrigerador solar para medicamentos mediante refrigeración por absorción
Authors: Zacarías Alejandro , Rivas San Germán Deneb , García Flores Alberto Iván , Barrera García Esteban Eduardo , Sánchez Fuentes Josué Gustavo , Romage Guerlin , Ramos López Gonzalo Alonso , Rubio Ávila José de Jesús , Flores Vasconcelos Alicia , Venegas Bernal María del Carmen
Published: September 2024

En este artículo se presenta el modelado y la simulación de un refrigerador solar para medicamentos mediante refrigeración por absorción y energía solar térmica. El modelado fue realizado mediante balance de masa y de energía en cada componente de cada subsistema. Las condiciones de operación para la simulación fueron de -25°C a -15°C en el evaporador y de 25 a 35 °C en el condensador. La temperatura de generación fue variada entre 55 y 95 °C. Los resultados mostraron que para una potencia frigorífica de 0.725 kW, el calor requerido en el generador que a su vez se requiere desde un colector solar, es de 1.2 kW aproximadamente, con coeficientes de operación del sistema de refrigeración entre 0.2 y 0.7. El área de colector requerida para producir 725 W, con un sistema de refrigeración por absorción puede ser de 4.5 m2 o máximo de aproximadamente 6.2 m2.
EVALUACIÓN DEL POTENCIAL DE UN SISTEMA HÍBRIDO INTERCAMBIADOR TIERRA-AIRE Y ENFRIAMIENTO EVAPORATIVO
Authors: Boubkari Asmae , Andrés Chicote Manuel , Tejero González Ana , Velasco Gómez Eloy
Published: September 2024

These days, everyone is concerned with conserving energy. Among the existing heating and cooling technologies to reduce energy consumption in buildings are the Earth-to-Air Heat Exchangers (EAHE). These systems can be combined with evaporative cooling, either direct or indirect, to improve the global performance. In the literature, hybrid solutions with direct evaporative cooling systems at the exit of EAHEs are proposed for indoor cooling. Due to limitations of indoor RH, most applications focus on greenhouses. Moreover, existing works target hot and arid climates. This work targets both indirect evaporative cooling (IEC) and direct evaporative cooling (DEC) to be combined with an EAHE installed at a near Zero Energy Building. The supplied relative humidity is analyzed to evaluate its feasibility for occupied spaces. The performance and energy savings achievable are studied through simulation using TRNSYS software.
Hermeticidad de edificios de nueva construcción de vivienda. Medición y resultados
Authors: Romero Rincón Manuel Jesús , Aguilar Valero Francisco Javier , Vicente Quiles Pedro Ginés
Published: September 2024

Mejorar la hermeticidad de los edificios, es decir, reducir las infiltraciones de aire, es importante pues su defecto supone un incremento de la demanda energética y puede ser la fuente de contaminantes en el aire interior, disconfort por corrientes de aire o pérdida de aislamiento acústico. La hermeticidad se evalúa mediante el «método de presurización con ventilador» o «blower door test» conforme a la norma UNE-EN ISO 9972. Para ello se instala un equipo formado por un ventilador y un dispositivo de medición de la presión, el flujo de aire y la temperatura. El ensayo se realiza en dos fases: una primera de despresurización en la que el ventilador extrae aire del interior del edificio y otra segunda de presurización en la que el ventilador impulsa aire al interior. La hermeticidad se determina a 50 Pa de presión y se caracteriza por el valor n50 que representa las renovaciones de aire a dicha presión. Se ha realizado una campaña con 111 ensayos en diferentes edificios de vivienda de obra nueva. El valor medio obtenido es de 11,04 [h-1], con un mínimo de 4,84 [h-1] y un máximo de 23,89 [h-1]. La mayoría supera los valores límite del DB-HE1
EFECTO DE LA CONSERVACIÓN REFRIGERADA EN LA CALIDAD DE LIMONES ‘FINO’ RECOLECTADOS EN DIFERENTES POSICIONES DEL ÁRBOL
Authors: Serna Escolano Vicente , Alonso Jesús Antonio , González Tenza Gema , Solivella Poveda Ana Micaela , Giménez Berenguer Marina , Giménez Torres María José
Published: September 2024

Los productores de limón demandan estrategias y herramientas que les permitan mejorar la gestión de los frutos. En este sentido, la posición del limón ‘Fino’ en el árbol puede determinar la calidad del fruto en el momento de la recolección, mientras que el sistema de conservación aplicado en post-cosecha colabora en mantener estables dichas características iniciales. Por lo tanto, en este trabajo se ha estudiado el efecto de la posición del limón en el árbol (fuera y dentro) conservado durante 15 días a 10 ºC. Los resultados tras 15 días de almacenamiento refrigerado mostraron que la tasa de respiración y las pérdidas de peso fueron menores en los frutos recolectados en las zonas internas del árbol. En cambio, color (a*), sólidos solubles totales y acidez titulable fueron superiores en los frutos de las zonas externas. Respecto al contenido en fenoles totales y actividad antioxidante total, los resultados mostraron una mayor concentración en la zona inferior del árbol. Por lo tanto, un manejo adecuado de los frutos durante la recolección y la aplicación de estrategias de frío colaborarían en mantener unos parámetros de calidad óptima del limón durante su comercialización.
EXPLORACIÓN DE LA MEZCLA RE170/R600: MEJORA DE LA EFICIENCIA COMO ALTERNATIVA AL R600a
Authors: Calleja Anta Daniel , Nebot Andrés Laura , Mártinez Ángeles Manel , Sánchez Daniel , Llopis Rodrigo
Published: September 2024

The utilization of alternative mixtures to R600a has been extensively explored across various applications, showcasing their potential to enhance the energy efficiency of isobutane in domestic refrigerators and standalone commercial appliances while maintaining comparable thermodynamic characteristics and operational performance parameters. Among these mixtures, those composed of a significant proportion of R600 (butane) and a small portion of secondary refrigerant have emerged as the most promising. However, many secondary refrigerants in these blends are synthetic. RE170 (dimethyl ether or DME), a non-fluorinated and natural refrigerant, has emerged as a particularly promising candidate for blending with R600. This paper presents an experimental analysis of the RE170/R600 refrigerant mixture as an alternative to R600a. For that purpose, a simple compressor highly equipper test bench was used, in which the mixture was analyzed at a composition range varying from 2.5/97.5%w to 27.5/72.5%w at steps of 2.5%. Results show COP increments up to 19.3% respect R-600a and VCC and  that low required DME matches the one obtained by R600a. RE170/R600 has been demonstrated to be a long-term superior efficiency mixture.
Analysis of the oil temperature in a scroll compressor with oil carter at discharge pressure using propane as refrigerant: Performance analysis for abnormally low oil volume
Authors: Gómez Parada Nicolás , Barceló Ruescas Francisco , Gonzálvez Maciá José
Published: September 2024

Scroll compressors are widely utilized in refrigeration systems and heat pumps, operating through the interaction of two spiral-shaped elements, one stationary and the other orbital. These elements fit together and continuously oscillate, compressing the fluid into diminishing volumes. They offer significant advantages such as high volumetric and compressor efficiencies, low vibrations, and reduced leaks. In direct suction scroll compressors, the oil sump is at discharge pressure, resulting in a wide pressure difference between the housing and the backpressure chamber; also, the oil temperature is higher than in the most common suction-side oil crankcase design. Knowing the oil temperature is crucial in determining the properties of the oil/refrigerant mixture that affect the system's performance. It also allows us to estimate the amount of refrigerant dissolved in the oil. In the current study, a series of tests are conducted under various operating conditions to measure the oil sump temperature in a direct suction scroll compressor. This experimental campaign was conducted using a compressor with an unusually low oil level, and an analysis of the system's performance was performed until a failure occurred.
Enfriamiento de un edificio de oficinas con un intercambiador de calor tierra-aire de gran diámetro
Authors: Rogerio Duarte  , Maria Glória Gomes  , António Moret Rodrigues  , Fernando Pimentel
Published: September 2024

Los intercambiadores de calor suelo-aire permiten amortiguar las oscilaciones de temperatura del aire exterior y enfriar edificios ubicados en climas cálidos y secos con muy pocos recursos además de los utilizados durante la construcción. A pesar del gran número de artículos científicos sobre intercambiadores suelo-aire, son pocos los trabajos que presentan datos de monitorización para intercambiadores funcionales con diámetro superior a 30 cm. El presente artículo presenta y discute datos de monitorización de un intercambiador de calor suelo-aire de gran diámetro construido para el enfriamiento de un edificio de oficinas existente. Los datos presentados fueron obtenidos durante un período característico de verano caliente y seco en el sur de Portugal. Se muestra que los gradientes de temperatura entre el aire exterior y el aire de salida del intercambiador alcanzan 9 K y que la capacidad de enfriamiento excede los 27 kW. Se discute el aprovechamiento de esta tecnología para el enfriamiento de edificios y se discuten los beneficios a nivel de la reducción de las emisiones de CO2 y del consumo de energía asociado al enfriamiento de edificios en climas cálidos y secos.
WITHDRAWN: P-Delta Effects Assessment in Precast Structures Via Inelastic Performance Based Spectra
Authors: Nascimbene Roberto , Sisti Andrea
Published: September 2024

The full text of this preprint has been withdrawn, as it was submitted in error. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.
Is women’s social independence a strong determinant for the reproductive health-related outcomes of the Turkish population?
Authors: Özdemir Raziye , Horasan Gönül Dinç
Published: September 2024

There is growing recognition of the importance of women's empowerment in achieving reproductive health goals. This study examined the relationships between various reproductive health outcomes and social independence using data from the 2018 Turkey Demographic and Health Survey. Social independence was measured by a modified form of the Survey-based Women's Empowerment (SWPER) Global Index's social independence domain. Adjusted prevalence ratios were calculated for the eight dependent variables by social independence quintiles. A total of 5,156 married women were analyzed. In the lower social independence quintiles, the prevalence ratios for having four or more births, having more children than the desired number, having an unwanted birth, using female-only contraceptive methods, induced abortions, and miscarriages were significantly higher than in the highest quintile. The study emphasizes the necessity of integrating women's empowerment into reproductive health policies by providing evidence that women's social independence is a strong predictor of numerous reproductive health outcomes.
In vivo medical imaging for assessing geroprotective interventions in humans
Authors: Svensson Jonas E. , Schain Martin , Sigray Pontus Plavén
Published: September 2024

There is a growing interest in developing drugs with a general geroprotective effect, aimed at slowing down aging. Several compounds have shown to increase the lifespan and reduce the incidence of age-related diseases in model organisms. Translating these results is challenging, due to the long lifespan of humans. To address this, we propose using a battery of medical imaging protocols that allow for assessments of age-related processes known to precede disease onset. These protocols, based on magnetic resonance imaging, positron emission-, computed-, and optical coherence tomography, are already in use in drug development and are available at most modern hospitals. Here, we outline how an informed use of these techniques allows for detecting changes in the accumulation of age-related pathologies in a diverse set of physiological systems. This in vivo imaging battery enables efficient screening of candidate geroprotective compounds in early phase clinical trials, within reasonable trial durations.
On-policy Actor-Critic Reinforcement Learning for Multi-UAV Exploration
Authors: Farid Ali Moltajaei , Roshanian Jafar , Mouhoub Malek
Published: September 2024

Unmanned aerial vehicles (UAVs) have become increasingly popular in various fields, including precision agriculture, search and rescue, and remote sensing. However, exploring unknown environments remains a significant challenge. This study aims to address this challenge by utilizing on-policy Reinforcement Learning (RL) with Proximal Policy Optimization (PPO) to explore the two dimensional area of interest with multiple UAVs. The UAVs will avoid collision with obstacles and each other and do the exploration in a distributed manner. The proposed solution includes actor-critic networks using deep convolutional neural networks (CNN) and long short-term memory (LSTM) for identifying the UAVs and areas that have already been covered. Compared to other RL techniques , such as policy gradient (PG) and asynchronous advantage actor-critic (A3C), the simulation results demonstrate the superiority of the proposed PPO approach. Also, the results show that combining LSTM with CNN in critic can improve exploration. Since the proposed exploration has to work in unknown environments, the results showed that the proposed setup can complete the coverage when we have new maps that differ from the trained maps. Finally, we showed how tuning hyper-parameters may affect the overall performance.
The role of the synaptic vesicle protein SV2A in regulating mitochondrial morphology and autophagy
Authors: Friedland Kristina , Jörg Marko , Reichert Jonas , Pauly Katharina , Distler Ute , Tenzer Stefan , Bartholomé Odile , Rogister Bernard , Kern Andreas , Behl Christian , Gelléri Márton , Cremer Christoph , Ritz Sandra , Peslalz Philipp , Plietker Bernd
Published: September 2024

The synaptic vesicle glycoprotein 2A (SV2A) is a transmembrane protein of synaptic vesicles. It is involved in key functions of neurons, focused on the regulation of neurotransmitter release. Here we report three novel findings suggesting a completely new role of SV2A. First, we demonstrate that SV2A is localized at the outer mitochondrial membrane (OMM) using confocal and super-resolution microscopy. Second, Inactivation of SV2A in our cell and animal models leads to fragmented mitochondria. In addition, SV2A also affects the basal autophagic flux as well as mitophagy. Third, using proteomics analysis we demonstrate that SV2A interacts with the fission factor DRP1 and the autophagy factor ATG9A. Using AlphaFold3 we provide a first glimpse of the molecular interaction between DRP1 and SV2A. Our findings demonstrate that SV2A is not only a vesicular protein but also a mitochondrial protein in the OMM with defined functions regulating mitochondrial morphology and autophagy.
Evaluation of a hand-held moisture meter for timely dead fine fuel moisture measurement
Authors: Dong Ziyu , Williams Roger Allen
Published: September 2024

Background:Timely and accurate measurement of dead fine fuel moisture is of great importance for fire assessment and prescribed fire management, but real-time field measurement techniques are limited. In this study, the accuracy of an electrical resistance wood moisture meter was evaluated to measure dead fine fuel moisture, including litter fuel, and 1-hour and 10-hour woody fuels. A total of ninety fuel samples were measured, with thirty samples for each fuel type. Oven-dry fuel moisture was used as the standard, the differences and relationships between the moisture meter and oven-dry measurements were analyzed. Fuel moisture index (FMI) was calculated as an alternative to assess moisture meter measurements, and the relationship between FMI and moisture meter measurements was examined.
Results: No significant differences were found in absolute differences between the two measurements across the three fuel types. A linear relationship between the two measurements was found for the full dataset, 1-hour woody fuel, and 10-hour woody fuel. FMI did not show significant relationships with moisture meter measurements for litter fuel, 1-hour woody fuel, and 10-hour woody fuel. A significant linear relationship was found between oven-dry litter fuel moisture and FMI.
Conclusions: The results suggested that the wood moisture meter has the capacity to provide a reasonable and timely estimate of litter fuel moisture. The moisture meter can be used as a coarse indicator and provide a general estimation.