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empirical models for the Evaluation of Global Solar Radiation for the Site of Abeche in the Province of Ouaddaï, in Chad

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Smart Grid and Renewable Energy 2022年第10期13卷 223-234页

作者： Marcel Hamda Soulouknga Abraham Dandoussou Noel Djongyang Higher Normal School of Technical Education of Sarh University of Sarh Sarh Chad Department of Electrical and Power Engineering Higher Technical Teachers’ Training School University of Buea Kumba Cameroon Department of Renewable Energy National Advanced Polytechnic School University of Maroua Maroua Cameroon

The global sustainability plan for future development relies on solar radiation which is the main source of renewable energy. Thus, this work studies the performance of six models to estimate global solar radiation on a horizontal surface for the Abeche site in Chad. The data used in this work were collected at the General Directorate of National Meteorology of Chad. The reliability and accuracy of different models for estimating global solar radiation were validated by statistical indicators to identify the most accurate model. The results show that among all the models, the Sabbagh model has the best performance in estimating the global solar radiation. The average is 6.354 kWh/m2 with an average of -3.704%. This model is validated against NASA data which is widely used.

关键词： empirical models Statistical Indicators Solar Radiation Abeche

Pyrolysis empirical Modeling of Polyester Glass Fiber Reinforced Plastics Using Sestak-Berggren Model Method

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Journal of Thermal Science 2024年第2期33卷 725-738页

作者： NAN Wei JI Wenhui YUAN Yanping YUAN Zhongyuan SUN Yong School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China CRRC Changchun Railway Vehicles Co. LtdChangchun130062China

Polyester Glass Fiber Reinforced Plastic(Polyester GFRP),a thermosetting plastic comprised of glass fiber and polyester polymer compounds,is extensively utilized in high-speed *** its pyrolysis mechanism is crucial as it significantly influences the combustion characteristics and fire safety ***,kinetic research on polyester GFRP primarily focuses on employing the Coats-Redfern method to derive a theoretical kinetic ***,the pyrolysis process of polyester GFRP is complex and the aforementioned theoretical model fails to accurately describe the pyrolysis ***,this study seeks to utilize the Sestak and Berggren(SB) model as a methodological approach to reveal the complex reaction mechanism during the pyrolysis *** on thermogravimetric analysis,the entire pyrolysis process of polyester GFRP is divided into two primary ***,model-free methods are employed to ascertain the activation energy and pre-exponential *** results show that the fitted empirical models of the two main pyrolysis stages are f(α)=(1-α)^(1.47)[-ln(1-α)]^(1.50) and f(α)=(1-α)^(1.77)[-ln(1-α)]^(1.72),*** predicted results are in good agreement with experimental data under different heating rates,which indicates that the empirical model can sufficiently describe the pyrolysis process of polyester GFRP.

关键词： polyester GFRP model-fitting methods empirical models pyrolysis

Estimation of monthly global solar radiation over twelve major cities of Libya

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Energy and Built Environment 2024年第1期5卷 46-57页

作者： Alhassan Ali Teyabeen Najeya B.Elhatmi Akram A.Essnid F.Mohamed Libyan Center for Solar Energy Research and Studies TripoliLibya Libyan Authority of Scientific Research TripoliLibya

This study aims to estimate monthly averaged daily horizontal global solar *** climatological data collected at twelve major cities located across Libya’s map were used to establish 7 different empirical *** empirical coefficients of the models were calculated using the least square *** accuracy of the models was evaluated using different statistical criteria such as Taylor diagram,mean absolute percentage error,MAPE,and root mean square error,*** results indicated that the sunshine duration-based models are more accurate than air temperature-based models,and the best performance was obtained by the quadratic regression model for all twelve Libyan ***,this regression model can be used for the prediction of monthly mean horizontal global solar radiation at a specific site across Libya’s regions with minimum ***,the results of the global solar irradiance produced by this method can be used for designing solar systems applications.

关键词： Monthly global solar radiation Clearness index empirical models Performance evaluation Taylor diagram Libya

Simulation and Analysis of the Effects of Pressure and Temperature on the Output Voltage of Proton Exchange Membrane Fuel Cells

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Journal of Power and Energy Engineering 2024年第2期12卷 1-16页

作者： Kashangabuye Bahufite Louis School of Automation Wuhan University of Technology Wuhan China

Proton exchange membrane fuel cell has advantages of high energy conversion efficiency, high reliability, no pollution, low operating temperature and rapid start-up. It has become an ideal method of hydrogen energy utilization and is also ideally suited to be used as the main source of energy for automobiles. Currently, it constitutes a research hot spot in the field of new energy vehicles. Based on the working mechanism of proton exchange membrane fuel cells and empirical models, a terminal voltage dynamic model, an open circuit voltage model and three voltage loss models are established. Matlab/Simulink software is utilized to simulate the model and perform analyses in response to the impact of operating temperature and pressure on its performance. To enhance the efficiency of the proton exchange membrane fuel cell, the operating temperature should be increased in the medium and low current density zones and the operating pressure should be increased in the high current density zone.

关键词： Hydrogen Energy New Energy Vehicles empirical models Voltage Dynamic Model

Modeling the Kinetics of Moisture Desorption from Safou Pulp [Dacryodes edulis (G. Don) ***] before the Oil Extraction Step

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Open Journal of Applied Sciences 2024年第8期14卷 2050-2064页

作者： Anicet Frédéric Binaki Feueltgaldah Christian Bopoundza Bob Wilfrid Loumouamou Gueko Séraphin Nguié Eliane Thérèse Biassala Thomas Silou Multidisciplinary Food and Nutrition Research Team Regional Center of Excellence in Food and Nutrition Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Process Engineering Laboratory UNESCO-ENSP Chair Marien Ngouabi University Brazzaville Congo CR2IE Chemistry and Technology Platform Higher School of Cataract Technology (EPrES) Brazzaville Congo

The aim of this work is to model the drying kinetics of Safou pulp with or without endocarp using a phenomenological approach. Oven-drying kinetics at 70˚C, 90˚C and 105˚C were monitored using the curves given by the reduced mass as a function of time, which are modeled according to the Avrami/page, Fick and Peleg models using OringinPro 2018 software. The results showed that parameters k and n of the Avrami/Page model vary very little with fruit size and drying temperature (0.0018 ± 0.0002 k n k (Avrami model/page) were virtually identical, while b (Fick model) and n (Avrami model/page) were virtually identical for the same sample. For the Peleg model, the parameter a, varies from 0.0018 ± 0.0002 to 0.03328 ± 0.0079, with a ratio of 18.6 for all experimental conditions studied. However, with 0.977 R2 χ2 models can be used to describe and predict the progress of oven-drying of safou pulp.

关键词： Drying Modeling empirical models Dacryodes edulis Congo Basin

Novel empirical model for predicting residual flexural capacity of corroded steel reinforced concrete beam

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Frontiers of Structural and Civil Engineering 2020年第4期14卷 888-906页

作者： Zhao-Hui LU Hong-Jun WANG Fulin QU Yan-Gang ZHAO Peiran LI Wengui LI Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Bejing University of TechnologyBeijing 100124China School of Civil Engineering Central South UniversityChangsha 410075China School of Civil and Environmental Engineering University of Technology SydneyNSW 2007Australia

In this study,a total of 177 flexural experimental tests of corroded reinforced concrete(CRC)beams were collected from the published *** database of flexural capacity of CRC beam was established by using unified and standardized experimental *** this database,the effects of various parameters on the flexural capacity of CRC beams were discussed,including beam width,the effective height of beam section,ratio of strength between longitudinal reinforcement and concrete,concrete compressive strength,and longitudinal reinforcement corrosion *** results indicate that the corrosion of longitudinal reinforcement has the greatest effect on the residual flexural capacity of CRC beams,while other parameters have much less *** addition,six available empirical models for calculating the residual flexural strength of CRC beams were also collected and compared with each other based on the established *** indicates that though five of six existing empirical models underestimate the flexural capacity of CRC beams,there is one model overestimating the flexural ***,a newly developed empirical model is proposed to provide accurate and effective predictions in a large range of corrosion ratio for safety assessment of flexural failure of CRC beams confirmed by the comparisons.

关键词： CRC beams flexural capacity steel corrosion database empirical models

SOCIAL MEDIA RESEARCH:A REVIEW

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Journal of Systems Science and Systems Engineering 2013年第3期22卷 257-282页

作者： Junjie WU Haoyan SUN Yong TAN School of Economics and Management Beihang University Michael G.Foster School of Business University of Washington

Social media is fundamentally changing the way people communicate, consume and collaborate. It provides companies a new platform to interact with their customers. In academia, there is a surge in research efforts on understanding its effects. This paper aims to provide a review of current status of social media research. We discuss the specific domains in which the impacts of social media have been examined. A brief review of applicable research methodologies and approaches is also provided.

关键词： social media empirical models experimental methods analytical approaches predictive analytics

Pan evaporation modeling in different agroclimatic zones using functional link artificial neural network

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Information Processing in Agriculture 2021年第1期8卷 134-147页

作者： Babita Majhi Diwakar Naidu Department of CSIT Guru Ghasidas VishwavidyalayaCentral UniversityBilaspur 495009India BRSM College of Agricultural Engineering and Technology and Research Station Indira Gandhi Krishi VishwavidyalayaMungeliIndia

Pan evaporation is an important climatic variable for developing efficient water resource management *** the past,many machine learning models are reported in the literature for pan evaporation modeling using the different combinationof available climatic *** order to develop a novel model with improved accuracy and reduced computational complexity,the functional link artificial neural network(FLANN)is chosen as an architecture to estimate daily pan evaporation in three agro-climatic zones(ACZs)of Chhattisgarh state in east-central *** neuron and single layer in its structure make it less complex as compared to other multilayer neural networks and neuro-fuzzy based hybrid *** results obtained with the FLANN model are compared with those obtained by multi-layer artificial neural networks(MLANN)and two empirical methods using the same raw data and corresponding *** indices like root mean square error(RMSE),mean absolute error(MAE)and efficiency factor(EF)is also computed to evaluate the model *** is demonstrated that pan evaporation estimates obtained with the proposed FLANN models provide an improved estimation of pan evaporation(RMSE=0.85 to 1.27 mm d^(-1),MAE=0.63 to 0.95 mm d^(-1) and EF=0.70 to 0.89)as compared to MLANN(RMSE=0.94 to 1.58 mm d^(-1),MAE=0.73 to 1.14 mm d^(-1) and EF=0.62 to 0.88)and empirical(RMSE=1.19 to 2.19 mm d^(-1),MAE=0.91 to 1.62 mm d^(-1) and EF=0.49 to 0.88)models in different ACZs.

关键词： Low complexity Pan evaporation estimation Functional link artificial neural network model Multi-layer artificial neural network model empirical models

Relationship between MODIS-NDVI data and wheat yield: A case study in Northern Buenos Aires province, Argentina

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Information Processing in Agriculture 2015年第2期2卷 73-84页

作者： Mariano F.Lopresti Carlos M.Di Bella Américo J.Degioanni Instituto Nacional de Tecnología Agropecuaria(INTA) EEA PergaminoRuta 32 km 4.5Pergamino 2700Buenos AiresArgentina INTA-Castelar CNIAInstituto de Clima y AguaLas Cabanas y Los Reseros S/NHurlingham 1686Buenos AiresArgentina UNRC Facultad de Agronomía y VeterinariaDepartamento de Ecología AgrariaRuta Nacional 36 km 601Río Cuarto 5800Co´rdobaArgentina CONICET–Consejo Nacional de Investigaciones Científicas y Técnicas Argentina

In countries like Argentina,whose economy depends heavily on crop production,the estimation of harvests is an elementary *** providing objectivity,the use of remote sensing allows estimating yield in *** the time of maximum leaf area in wheat corresponds with the critical period of the crop,a good relationship is expected between the Normalized Difference Vegetation Index(NDVI)and *** present study was carried out in the North of Buenos Aires province,*** on the type of soil,the study area can be divided into two homogeneous subzones:a subzone with lower clay content in the southwestand a subzone with higher clay content in the *** growing seasons(2003–2011)were *** the first five years,an empirical model was calibrated and validated with field-observed wheat yields and MOD13q1 product-NDVI data,whereas in the other four years,the calibrated model was applied by means of yield maps and by comparing with official *** MOD13q1 image corresponding to Julian day 289 showed the best fit between NDVI and yield to estimate wheat yield *** yield maps,better weather conditions showedhigher yields and higher soil productivity presented a greater proportion of the area occupied by higher *** department level,an R2 value of 0.75 was found after relating the estimation of the calibrated empirical model with official *** method used allows predicting wheat yield 30 days before *** yield maps,the NDVI perceived the temporal and spatial variability in the study area.

关键词： Remote sensing Wheat NDVI Yield empirical models MODIS