1,720,999 research outputs found
Étude du rafraîchissement passif de bâtiments commerciaux ou industriels
No full textCommercial and industrial buildings represent a significant part of total energy demand. The objective of this thesis is to study the thermal behavior and airflows of commercial or industrial buildings (low-rise and large volume) by numerical simulations, to improve their thermal performance in order to reduce their energy consumption while maintaining thermal comfort of the occupants. The first part of this study consists in identifying and evaluating the keys factors that affect the energy demand and thermal comfort of these buildings. Using the developed models (multizone and zonal), we present the impact of the most important parameters (building orientation, thermal insulation, radiative properties of the roof, soil, internal thermal inertia, air diffusion…) on energy consumption and thermal comfort. We have identified here that the main influencing parameters can be found in the design of the roof and the ground floor considering the energy performance of the studied building. The developed model is then applied to a real commercial building. Results showed that the predictions are in good agreement with the measurements and that night-time natural ventilation can be an efficient passive cooling technique to avoid overheating in summer. In the second part, we evaluate the efficiency of different passive cooling techniques (thermal insulation, night-time natural ventilation, cool roof…) applied to ensure the thermal comfort in winter as well as in summer while minimizing the energy consumption. Finally, an optimization study is proposed to determine the optimal set of parameters for both objective functions considering the passive cooling techniques and the energy demand according to different climatic zones.Les bâtiments commerciaux et industriels présentent une part non négligeable de la demande énergétique. L’objectif de ce travail de thèse est d’étudier par des simulations numériques, le comportement thermoaéraulique des bâtiments de grand volume à usage commercial ou industriel et d’améliorer leurs performances afin de réduire leurs consommations énergétiques tout en assurant le confort thermique des occupants. La première partie de l’étude consiste à définir et à évaluer les paramètres d’enveloppe et de ventilation qui affectent la consommation d’énergie et le confort thermique de ce type de bâtiment. À travers des modèles développés (multizone et zonal) sur un bâtiment « générique », nous présentons l’impact des paramètres les plus importants (orientation du bâtiment, isolation thermique de l’enveloppe, propriétés radiatives de la toiture, sol, inertie thermique interne, diffusion de l’air…) sur la consommation énergétique et le confort. Ces paramètres sont déterminants surtout dans la conception de la toiture et du plancher de par leur influence sur les performances énergétiques du bâtiment étudié. Cette modélisation thermoaéraulique est ensuite appliquée à un bureau-entrepôt commercial existant. L’exploitation du modèle, dont les résultats sont confrontés aux mesures, et des études paramétriques permettent de démontrer l’efficacité de stratégies de ventilation naturelle nocturne. Dans la deuxième partie, nous évaluons certaines solutions de rafraîchissement passif (isolation thermique, ventilation naturelle nocturne, revêtement de toiture « cool roof ») permettant de maintenir le confort thermique en hiver aussi bien qu’en été tout en minimisant la consommation énergétique. Enfin, une étude d’optimisation nous permet de déterminer les paramètres optimums en fonction des conditions climatiques et des deux objectifs de confort et de performance énergétique. Ce travail ouvre de nombreuses perspectives sur la méthodologie de conception des enveloppes et l’adaptation du fonctionnement des installations de ventilation pour le rafraîchissement passif des bâtiments
Passive cooling study of low-rise commercial or industrial building
No full textLes bâtiments commerciaux et industriels présentent une part non négligeable de la demande énergétique. L’objectif de ce travail de thèse est d’étudier par des simulations numériques, le comportement thermoaéraulique des bâtiments de grand volume à usage commercial ou industriel et d’améliorer leurs performances afin de réduire leurs consommations énergétiques tout en assurant le confort thermique des occupants. La première partie de l’étude consiste à définir et à évaluer les paramètres d’enveloppe et de ventilation qui affectent la consommation d’énergie et le confort thermique de ce type de bâtiment. À travers des modèles développés (multizone et zonal) sur un bâtiment « générique », nous présentons l’impact des paramètres les plus importants (orientation du bâtiment, isolation thermique de l’enveloppe, propriétés radiatives de la toiture, sol, inertie thermique interne, diffusion de l’air…) sur la consommation énergétique et le confort. Ces paramètres sont déterminants surtout dans la conception de la toiture et du plancher de par leur influence sur les performances énergétiques du bâtiment étudié. Cette modélisation thermoaéraulique est ensuite appliquée à un bureau-entrepôt commercial existant. L’exploitation du modèle, dont les résultats sont confrontés aux mesures, et des études paramétriques permettent de démontrer l’efficacité de stratégies de ventilation naturelle nocturne. Dans la deuxième partie, nous évaluons certaines solutions de rafraîchissement passif (isolation thermique, ventilation naturelle nocturne, revêtement de toiture « cool roof ») permettant de maintenir le confort thermique en hiver aussi bien qu’en été tout en minimisant la consommation énergétique. Enfin, une étude d’optimisation nous permet de déterminer les paramètres optimums en fonction des conditions climatiques et des deux objectifs de confort et de performance énergétique. Ce travail ouvre de nombreuses perspectives sur la méthodologie de conception des enveloppes et l’adaptation du fonctionnement des installations de ventilation pour le rafraîchissement passif des bâtiments.Commercial and industrial buildings represent a significant part of total energy demand. The objective of this thesis is to study the thermal behavior and airflows of commercial or industrial buildings (low-rise and large volume) by numerical simulations, to improve their thermal performance in order to reduce their energy consumption while maintaining thermal comfort of the occupants. The first part of this study consists in identifying and evaluating the keys factors that affect the energy demand and thermal comfort of these buildings. Using the developed models (multizone and zonal), we present the impact of the most important parameters (building orientation, thermal insulation, radiative properties of the roof, soil, internal thermal inertia, air diffusion…) on energy consumption and thermal comfort. We have identified here that the main influencing parameters can be found in the design of the roof and the ground floor considering the energy performance of the studied building. The developed model is then applied to a real commercial building. Results showed that the predictions are in good agreement with the measurements and that night-time natural ventilation can be an efficient passive cooling technique to avoid overheating in summer. In the second part, we evaluate the efficiency of different passive cooling techniques (thermal insulation, night-time natural ventilation, cool roof…) applied to ensure the thermal comfort in winter as well as in summer while minimizing the energy consumption. Finally, an optimization study is proposed to determine the optimal set of parameters for both objective functions considering the passive cooling techniques and the energy demand according to different climatic zones
Étude du rafraîchissement passif de bâtiments commerciaux ou industriels
No full textCommercial and industrial buildings represent a significant part of total energy demand. The objective of this thesis is to study the thermal behavior and airflows of commercial or industrial buildings (low-rise and large volume) by numerical simulations, to improve their thermal performance in order to reduce their energy consumption while maintaining thermal comfort of the occupants. The first part of this study consists in identifying and evaluating the keys factors that affect the energy demand and thermal comfort of these buildings. Using the developed models (multizone and zonal), we present the impact of the most important parameters (building orientation, thermal insulation, radiative properties of the roof, soil, internal thermal inertia, air diffusion…) on energy consumption and thermal comfort. We have identified here that the main influencing parameters can be found in the design of the roof and the ground floor considering the energy performance of the studied building. The developed model is then applied to a real commercial building. Results showed that the predictions are in good agreement with the measurements and that night-time natural ventilation can be an efficient passive cooling technique to avoid overheating in summer. In the second part, we evaluate the efficiency of different passive cooling techniques (thermal insulation, night-time natural ventilation, cool roof…) applied to ensure the thermal comfort in winter as well as in summer while minimizing the energy consumption. Finally, an optimization study is proposed to determine the optimal set of parameters for both objective functions considering the passive cooling techniques and the energy demand according to different climatic zones.Les bâtiments commerciaux et industriels présentent une part non négligeable de la demande énergétique. L’objectif de ce travail de thèse est d’étudier par des simulations numériques, le comportement thermoaéraulique des bâtiments de grand volume à usage commercial ou industriel et d’améliorer leurs performances afin de réduire leurs consommations énergétiques tout en assurant le confort thermique des occupants. La première partie de l’étude consiste à définir et à évaluer les paramètres d’enveloppe et de ventilation qui affectent la consommation d’énergie et le confort thermique de ce type de bâtiment. À travers des modèles développés (multizone et zonal) sur un bâtiment « générique », nous présentons l’impact des paramètres les plus importants (orientation du bâtiment, isolation thermique de l’enveloppe, propriétés radiatives de la toiture, sol, inertie thermique interne, diffusion de l’air…) sur la consommation énergétique et le confort. Ces paramètres sont déterminants surtout dans la conception de la toiture et du plancher de par leur influence sur les performances énergétiques du bâtiment étudié. Cette modélisation thermoaéraulique est ensuite appliquée à un bureau-entrepôt commercial existant. L’exploitation du modèle, dont les résultats sont confrontés aux mesures, et des études paramétriques permettent de démontrer l’efficacité de stratégies de ventilation naturelle nocturne. Dans la deuxième partie, nous évaluons certaines solutions de rafraîchissement passif (isolation thermique, ventilation naturelle nocturne, revêtement de toiture « cool roof ») permettant de maintenir le confort thermique en hiver aussi bien qu’en été tout en minimisant la consommation énergétique. Enfin, une étude d’optimisation nous permet de déterminer les paramètres optimums en fonction des conditions climatiques et des deux objectifs de confort et de performance énergétique. Ce travail ouvre de nombreuses perspectives sur la méthodologie de conception des enveloppes et l’adaptation du fonctionnement des installations de ventilation pour le rafraîchissement passif des bâtiments
Learning Media Development for Continuously Variable Transmission Automatic Transmission System Subjects on Motorcycles
Get PDFTeaching aids that have similarities to tools are actually very helpful in learning. In improving students' understanding, learning media is needed, namely a simulator. This study aims to design a Continuously Variable Transmission (CVT) simulator with validity, practicality and effectiveness, useful to be used as a medium of learning in schools in the subject of automatic transmission systems. The type of research used is Research and Development (R&D) with 4-D model development procedures. This research consists of four stages, namely: Define, Design, Develop, and Disseminate. The subjects used were students of SMKN 1 Koto Baru Dharmasraya, the technical analysis of the data used was technical analysis from experts by looking at the validity, practicality and effectiveness of the simulator. To see the difference between the average score of learning scores before and after using a simulator with Gain Score and Standard Deviation. The results showed that the simulator met the principle of relevance from expert judgment with a level of 0.81 which was declared a valid category, on practicality based on the teacher's response it was declared practical with a value of 87.33% and student responses with a value of 92.42%. The effectiveness of the tool is declared effective. On the results of the pretest with an average score of 56.00%, the results of the posttest with an average score of 73.00%, on the N-gain the overall average of students is 0.37 and on the standard deviation seen from the N-gain of 0.12. Based on the development of this media, it can be concluded that the simulator is valid, practical and effective in learning at school
Pengaruh Penambahan Bahan Bakar Pirolisis Plastik Terhadap Daya dan Torsi pada Sepeda Motor Injeksi 108 cc
Get PDFThis study aims to determine the effect of the fuel mixture pertalite and pyrolysis fuel on the power and torque of the 108cc injection motorbike. This study used an experimental method with mixed variations (PE5%, PE10%, PE15%, PE20%). The object of this research was the Honda Beat eSP 108cc 2015. The characteristics of the density of the pyrolysis fuel were 0.72 kg/liter which was equivalent to gasoline fuel. Based on the results of the study, there was an increase in power and torque in the various mixtures of PE5%, PE10%, PE15% and PE20%. In the PE20% fuel mixture, power and torque decreased slightly with the previous mixture but were still above PE5%. From the comparison of the mixed variations that have been carried out on injection motorbikes, there is an influence on power and torque.
Penelitian ini bertujuan untuk mengetahui pengaruh campuran bahan bakar pertalite dengan bahan bakar pirolisis terhadap daya dan torsi sepeda motor injeksi 108cc. Penelitian ini menggunakan metode eksperimen dengan variasi campuran (PE5%, PE10%, PE15%, PE20%). Objek penelitian ini adalah sepeda motor Honda Beat eSP 108cc tahun 2015. Karakteristik densitas bahan bakar pirolisis yang di lakukan sebesar 0,72 kg/l yang setara dengan bahan bakar bensin. Berdasarkan hasil penelitian bahwa terjadi peningkatan daya dan torsi di variasi campuran PE5%, PE10%, PE15% dan PE20%. Pada campuran bahan bakar PE20%, daya dan torsi mengalami penurunan sedikit dengan campuran sebelumnya tetapi masih diatas PE5%. Dari perbandingan variasi campuran yang telah dilakukan pada sepeda motor injeksi terdapat pengaruh terhadap daya dan torsi
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Validating the Rifdarmon E-Learning Model with Structural Equation Modeling Analysis for Enhanced Learning Outcomes and Students’ 4C Skills
No full textThe rapid development of information and communication technology (ICT) has significantly transformed the landscape of education, including in the context of vocational education. Universitas Negeri Padang (UNP), particularly the Department of Automotive Engineering, has made efforts to adapt the curriculum and learning methods to bridge the gap between education and industry demands. However, in its implementation, there are still challenges that need to be addressed, especially in the Automotive Electronics Electricity course. This study aims to validate the Rifdarmon E-Learning Model in the Automotive Electronics Electricity course through SEM-PLS and CB-SEM analysis using SmartPLS 4. The research employed a quantitative approach using two analysis methods: Structural Equation Modeling-Partial Least Square (SEM-PLS) and Covariance-Based Structural Equation Modeling (CB-SEM). Data were collected from 50 validators comprising experts in educational technology, learning models, and learning media using a 5-point Likert scale questionnaire. The model validation focused on four key syntaxes: Reciprocal Teaching (RT), Mentoring Peers (MP), Organizing Findings (OF), and Narrating Outcomes (NO). The SEM-PLS analysis demonstrated strong construct validity with satisfactory Composite Reliability (CR), Cronbach's Alpha, and Average Variance Extracted (AVE) values across all syntaxes. The CB-SEM analysis further confirmed the model's structural validity with positive outer loading values and good model fit indices. These comprehensive validation results indicate that the Rifdarmon E-Learning Model is both valid and reliable, making it suitable for implementation to enhance learning outcomes and develop students' 4C skills in Automotive Electronics Electricity education
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