Annals of West University of Timisoara Physics最新文献_第5页

Effectiveness of Geant4 in Monte Carlo Simulation Studyofphonon Conduction in Sn Host with Si Nanowire Interface Geant4在具有Si纳米线界面的Sn基体中声子传导的蒙特卡罗模拟研究中的有效性

Annals of West University of Timisoara Physics Pub Date : 2019-12-01 DOI: 10.2478/awutp-2019-0001

C. Iheduru, M. Eleruja, B. Olofinjana, O. E. Awe, A. Buba

引用次数: 0

Spin Coating Method Fabricated of In2O3 Thin Films 旋转镀膜法制备In2O3薄膜

Annals of West University of Timisoara Physics Pub Date : 2019-12-01 DOI: 10.2478/awutp-2019-0005

S. Benramache, Y. Aoun

引用次数: 2

Solutions of the Dirac Equation in a Bardeen Black Hole Geometry 巴丁黑洞几何中狄拉克方程的解

Annals of West University of Timisoara Physics Pub Date : 2019-12-01 DOI: 10.2478/awutp-2018-0013

C. Sporea

引用次数: 0

Estimating Global Solar Radiation from Routine Meteorological Parameters Over a Tropical City (7.23°N; 3.52°E) Using Quadratic Models 利用常规气象参数估算热带城市(7.23°N)太阳总辐射3.52°E)使用二次模型

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0005

G. I. Olatona

{"title":"Estimating Global Solar Radiation from Routine Meteorological Parameters Over a Tropical City (7.23°N; 3.52°E) Using Quadratic Models","authors":"G. I. Olatona","doi":"10.2478/awutp-2018-0005","DOIUrl":"https://doi.org/10.2478/awutp-2018-0005","url":null,"abstract":"Abstract The need for adequate solar radiation is ever increasing for various applications. However there is an inadequate data of solar radiation in many countries due to the cost of instrument set up. Hence this study investigates two models for estimating solar radiation from routinely measured meteorological parameters. The data were obtained from the International Institute of Tropical Agriculture, Ibadan. The regression coefficients of the quadratic models were determined and used to estimate the global solar radiation for both forward and backward predictions. Their predictive accuracies were compared with four other models and the measured values using standard statistical error indicators. The results showed for forward as compared to backward predictions in bracket root mean square errors 1.2 (1.1); mean bias errors 1.1 (0.8) and mean percentage errors -4.8% (-2.9%) while for backward prediction 1.9 (1.7), 1.7 (1.4) and 7.9% (2.2%) measured in KJm−2day−1 respectively. A positive error value shows an over estimation while a negative value shows an under estimation. The models are versatile for estimating global solar radiation at the horizontal surface, fixing missing data and correcting outliers.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76881025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Effect of Cu2O Morphology on Photovoltaic Performance of P-Type Dye-Sensitized Solar Cells Cu2O形态对p型染料敏化太阳能电池光电性能的影响

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0007

D. Ursu, A. Dabici, Melinda Vajda, Neli-Camelia Bublea, N. Duțeanu, M. Miclau

引用次数: 2

Experimental Assessment of the Meliss Simulation Model Accuracy of the Direct Solar Irradiance in Brasov, Romania 罗马尼亚布拉索夫Meliss太阳直接辐照度模拟模型精度的实验评估

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0003

Camelia Liliana Moldovan, R. Păltănea, I. Visa

{"title":"Experimental Assessment of the Meliss Simulation Model Accuracy of the Direct Solar Irradiance in Brasov, Romania","authors":"Camelia Liliana Moldovan, R. Păltănea, I. Visa","doi":"10.2478/awutp-2018-0003","DOIUrl":"https://doi.org/10.2478/awutp-2018-0003","url":null,"abstract":"Abstract The solar irradiance is the main input parameter when designing solar energy conversion systems. A poor accuracy of the solar irradiance simulation models negatively affect the output energy and the durability of the solar energy conversion system. In the paper, the measured values of the direct solar irradiance in the entire month of July 2016 are analysed and, based on the daily received direct solar energy and the variability of the direct solar irradiance, the days are classified in four categories: clear sky days, partially clear sky days, partially cloudy days and cloudy days. Based on this classification, only four clear sky days were identified in July 2016. The same procedure was applied for the months of July 2013, 2014 and 2015 resulting 13 clear sky days in the entire monitoring period of four years (2013-2016). The measured values of the direct solar irradiance in these 13 selected clear sky days are comparatively analysed against the direct solar irradiance simulated with Meliss clear sky model. Further on, a statistical analysis is performed for the time interval 8:00-16:00 to evaluate absolute, relative and root mean square errors between the measured and simulated values. The results show that the simulation model overestimates, in eleven out of the thirteen clear sky days, the solar direct irradiance in the central part of the day. The measurements were performed in the Renewable Energy Systems and Recycling (RESREC) Research Centre located in the R&D Institute of the Transilvania University of Brasov, Romania.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83454001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling of Daily Global Solar Irradiation in Timisoara by Using a Fuzzy Approach 用模糊方法模拟蒂米什瓦拉日全球太阳辐照

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0004

R. Boata

引用次数: 2

Improved Model for Forecasting Global Solar Irradiance During Sunny and Cloudy Days 预测晴天和阴天全球太阳辐照度的改进模式

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0002

B. Burduhos, M. Neagoe

{"title":"Improved Model for Forecasting Global Solar Irradiance During Sunny and Cloudy Days","authors":"B. Burduhos, M. Neagoe","doi":"10.2478/awutp-2018-0002","DOIUrl":"https://doi.org/10.2478/awutp-2018-0002","url":null,"abstract":"Abstract A precise estimation of the electrical energy produced daily by photovoltaic (PV) systems is important both for PV owners and for electrical grid operators. It can be achieved if the received solar irradiance can be accurately estimated during any type of daily solar profile (clear, cloudy, mixed sky), not only average solar profile for larger periods of time, e.g. one month or season, as used in PV system design. The paper firstly describes an existing mathematical model, based on the Meliss approach, which uses mean monthly coefficients for estimating average direct and diffuse solar irradiance. This model is satisfactory for monthly/annual intervals but is not useful for daily estimations. Therefore in the second part of the paper an algorithm which allows to generate daily variations of the model’s coefficients for clear and cloudy sky conditions is proposed. The improved model with variable coefficients was tested during several representative days and can be used for estimating the effect which different meteorological conditions as fog/dew/frost have on the quantity and quality of the solar irradiance received by a PV convertor.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91279461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Fluid Flow Control in Domestic Hot Water Systems During Days with Different Radiative Stability Levels 不同辐射稳定水平下生活热水系统的流量控制

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0009

S. Budea, V. Badescu

{"title":"Fluid Flow Control in Domestic Hot Water Systems During Days with Different Radiative Stability Levels","authors":"S. Budea, V. Badescu","doi":"10.2478/awutp-2018-0009","DOIUrl":"https://doi.org/10.2478/awutp-2018-0009","url":null,"abstract":"Abstract This paper presents models/strategies for optimum performance of solar collector in closed loop systems. These models aim to maximize the obtained energy by thermal conversion of solar energy. The mass flow rate of the fluid from the primary circuit of the system is the control parameter. The semi empirical models and optimal control methods are in brief presented. The volume of the storage tank is important and the ratio Vs/Ac between this volume and area of the collectors is a key factor in appropriate sizing of the DHW system. Therefore, the paper establishes a relationship between this ratio and the mass flow rate of the fluid in the collector This paper also analyses the variation of the energetic performance (useful heat flux transferred to the storage tank, heat flux transferred to the water, water temperature in the storage tank) with the volume of the storage tank. Analysis was performed on an extensive set of meteorological data from Timisoara, Romania, with instantaneous data (measured at 15 seconds) for summer days, from July 2009, with different relative sunshine values, σ. Important differences have been observed between days with different stability levels - days more or less stable.","PeriodicalId":31012,"journal":{"name":"Annals of West University of Timisoara Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87331678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Aerosol on the Estimation Accuracy of Solar Radiation 气溶胶对太阳辐射估算精度的影响

Annals of West University of Timisoara Physics Pub Date : 2018-08-01 DOI: 10.2478/awutp-2018-0010

Calinoiu Delia-Gabriela, Paulescu Marius

引用次数: 0