scholarly journals Distribution of the monthly global solar irradiation in the State of Tabasco, Mexico

Author(s):  
Lorenzo Armando Aceves Navarro ◽  
Alberto Santillán Fernández ◽  
Benigno Rivera-Hernández ◽  
Rigoberto González Mancillas ◽  
Agrícola Arrieta-Rivera ◽  
...  

Objective: To estimate the monthly average global solar irradiance (Rg), using observed cloudiness data (% of cloudy days), as well as its spatial distribution for the state of Tabasco, Mexico.Design/Methodology/Approximation: The proposed model by Tejeda-Martínez et al. (1999) was adjusted to estimate the Rg of 35 meteorological stations in the state of Tabasco. The adjustment was performed with daily observed Rg data fromeight automated weather stations and cloudiness data from eight ordinary weather stations. Results: The proposed model reports a good fit, given that its prediction was optimal according to Willmotts comparison parameter (c = 0.89), and excellent based on the Nash-Sutcliffe efficiency index (E = 0.99) and had a high corrected determination coefficient of Rc2 = 0.87.Study limitations/implications: It is necessary that in the state of Tabasco the number of automated stations increase, as well as technical maintenance to the existing stations.Findings/conclusions: The estimated Rg is statistically reliable. The highest Rg values occurred during the dry season, with a maximum of 22.99 MJ m -2 d -1 , distributed mainly in the northern part of the state. The lowest Rg values occurredduring the northeast season (12.52 MJ m -2 d -1 ), distributed in more than 80 % of the total state area.

PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0205253 ◽  
Author(s):  
Sheila Cristina Rocha-Brischiliari ◽  
Luciano Andrade ◽  
Oscar Kenji Nihei ◽  
Adriano Brischiliari ◽  
Michele dos Santos Hortelan ◽  
...  

Author(s):  
Débora de S. Simões ◽  
Denise C. Fontana ◽  
Matheus B. Vicari

ABSTRACTAlthough frost occurrence causes severe losses in agriculture, especially in the south of Brazil, the data of minimum air temperature (Tmin) currently available for monitoring and predicting frosts show insufficient spatial distribution. This study aimed to evaluate the MDY11A1 (LST – Land Surface Temperature) product, from the MODIS sensor on board the AQUA satellite as an estimator of frost occurrence in the southeast of the state of Rio Grande do Sul, Brazil. LST images from the nighttime overpass of the MODIS/AQUA sensor for the months of June, July and August from 2006 to 2012, and data from three conventional weather stations of the National Institute of Meteorology (INMET) were used. Consistency was observed between Tmin data measured in weather stations and LST data obtained from the MODIS sensor. According to the results, LSTs below 3 ºC recorded by the MODIS/AQUA sensor are an indication of a favorable scenario to frost occurrence.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Chong Li

The objective of this paper is to establish the performance of 8 kWp grid-connected photovoltaic (PV) power systems based on different PV module technologies in Nanjing, China. Nanjing has a hot summer and a cold winter which are considered based on monthly average solar irradiation and ambient temperature specifically for the deployment of grid-connected PV systems. The study focuses on performance assessment of grid-connected PV systems using typical PV modules made of monocrystalline silicon (m-Si), polycrystalline silicon (p-Si), edge-defined film-fed growth silicon (EFG-Si), cadmium telluride (CdTe) thin film, copper indium selenide (CIS) thin film, heterojunction with intrinsic thin layer (HIT), and hydrogenated amorphous silicon single-junction (a-Si:H single-PV) installed on location. The yearly average energy output, PV module and system efficiency, array yield, final yield, reference yield, performance ratio, monthly average array capture losses, and system losses of seven PV module technologies are all analyzed. The results show that grid-connected PV power system performance depends on geographical location, PV module types, and climate conditions such as solar radiation and ambient temperature. In addition, based on energy output and efficiency, the HIT PV power technology can be considered as the best option and CdTe and p-Si as the least suitable options for this area. The monthly average performance ratio of the CdTe technology was higher than those of other technologies over the monitoring period in Nanjing.


2018 ◽  
Vol 7 (2.17) ◽  
pp. 70
Author(s):  
Jaiganesh K ◽  
Karuppiah N ◽  
Ravivarman S ◽  
Md Asif

The maximum electrical energy conversion efficiency of the Solar PV panel is up to 22% in normal conventional roof- top system under the temperature of 25˚C on Standard Test Condition (STC). In Indian climatic conditions, the atmospheric temperature is mostly above 35˚C to 45˚C, it incites 35˚C to 80˚C temperature on the PV panel. The black body of the PV panel absorbs more heat. This temperature affects the electrical efficiency of the panel significantly. This paper proposes the mathematical modelling of the solar PV panel for different solar irradiation and the temperature. The experimental evaluation is conducted in the latitude of 11.36 (N) and longitude 77.82 (E). The testing and monitoring was done with LabVIEW based National Instruments hardware such as NI cDAQ-9178, NI DAQ - 9227 and NI DAQ 9225. The comparative study between the simulated result and real time hardware results are discussed in this paper. The test result shows that the output of the proposed model mismatches with the experimental output of the solar PV panel due to the negative correlation between the efficiency and temperature for variable irradiation condition. It shows a power difference of 9.41W between the output of the proposed model and the experimental setup.  


2013 ◽  
Vol 65 (2) ◽  
pp. 553-558
Author(s):  
W.S. Tassinari ◽  
M.C. Lorenzon ◽  
E.L. Peixoto

Brazilian beekeeping has been developed from the africanization of the honeybees and its high performance launches Brazil as one of the world´s largest honey producer. The Southeastern region has an expressive position in this market (45%), but the state of Rio de Janeiro is the smallest producer, despite presenting large areas of wild vegetation for honey production. In order to analyze the honey productivity in the state of Rio de Janeiro, this research used classic and spatial regression approaches. The data used in this study comprised the responses regarding beekeeping from 1418 beekeepers distributed throughout 72 counties of this state. The best statistical fit was a semiparametric spatial model. The proposed model could be used to estimate the annual honey yield per hive in regions and to detect production factors more related to beekeeping. Honey productivity was associated with the number of hives, wild swarm collection and losses in the apiaries. This paper highlights that the beekeeping sector needs support and help to elucidate the problems plaguing beekeepers, and the inclusion of spatial effects in the regression models is a useful tool in geographical data.


2014 ◽  
Vol 48 (4) ◽  
pp. 662-670 ◽  
Author(s):  
Ioná Carreno ◽  
Ana Lúcia de Lourenzi Bonilha ◽  
Juvenal Soares Dias da Costa

OBJECTIVE To analyze the temporal evolution of maternal mortality and its spatial distribution.METHODS Ecological study with a sample made up of 845 maternal deaths in women between 10 and 49 years, registered from 1999 to 2008 in the state of Rio Grande do Sul, Southern Brazil. Data were obtained from Information System on Mortality of Ministry of Health. The maternal mortality ratio and the specific maternal mortality ratio were calculated from records, and analyzed by the Poisson regression model. In the spatial distribution, three maps of the state were built with the rates in the geographical macro-regions, in 1999, 2003, and 2008.RESULTS There was an increase of 2.0% in the period of ten years (95%CI 1.00;1.04; p = 0.01), with no significant change in the magnitude of the maternal mortality ratio. The Serra macro-region presented the highest maternal mortality ratio (1.15, 95%CI 1.08;1.21; p < 0.001). Most deaths in Rio Grande do Sul were of white women over 40 years, with a lower level of education. The time of delivery/abortion and postpartum are times of increased maternal risk, with a greater negative impact of direct causes such as hypertension and bleeding.CONCLUSIONS The lack of improvement in maternal mortality ratio indicates that public policies had no impact on women’s reproductive and maternal health. It is needed to qualify the attention to women’s health, especially in the prenatal period, seeking to identify and prevent risk factors, as a strategy of reducing maternal death.


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