Forecasting of daily total horizontal solar radiation using grey wolf optimizer and multilayer perceptron algorithms

Solar radiation data is an indispensable input for photovoltaic and solar-thermal systems. In this regard, the consistent solar radiation forecasting is a primary task in solar energy applications. In this paper, grey wolf optimizer algorithm is integrated to the multilayer perceptron algorithm in order to forecast the daily total horizontal solar radiation. In the forecasting phase, air temperature, relative humidity and diffuse horizontal solar radiation parameters are evaluated in 3-tupled and 2-tupled input structure. In addition, the accuracy of the hybrid forecasting model developed is also tested on the basis of the sigmoid, sinus and hyperbolic tangent activation functions employed in the multilayer perceptron algorithm. The forecasting results show that grey wolf optimizer-based multilayer perceptron model is appropriate to predict the daily total horizontal solar radiation, efficiently

Daily photovoltaic power prediction enhanced by hybrid GWO-MLP, ALO-MLP and WOA-MLP models using meteorological information

Solar energy is a safe, clean, environmentally-friendly and renewable energy source without any carbon emissions to the atmosphere. Therefore, there are many studies in the field of solar energy in order to obtain the maximum solar radiation during the day time, to estimate the amount of solar energy to be produced, and to increase the efficiency of solar energy systems. In this study, it was aimed to predict the daily photovoltaic power production using air temperature, relative humidity, total horizontal solar radiation and diffuse horizontal solar radiation parameters as multi-tupled inputs. For this purpose, grey wolf, ant lion and whale optimization algorithms were integrated to the multilayer perceptron. In addition, the effects of sigmoid, sinus and hyperbolic tangent activation functions on the prediction performance were analyzed in detail. As a result of overall accuracy indictors achieved, the grey wolf optimization algorithm-based multilayer perceptron model was found to be more successful and competitive for the daily photovoltaic power prediction. Furthermore, many meaningful patterns were revealed about the constructed models, input tuples and activation functions

Standards-based investigation of voltage dips and voltage imbalances in an organized industrial zone

IEEE Industrial Electronics Society (IES);IEEE Industry Applications Society (IAS);New University of Lisbon;Technical University of Sofia;The Institute of Electrical and Electronics Engineers (IEEE)17th IEEE International Power Electronics and Motion Control Conference, PEMC 2016 --25 September 2016 through 28 September 2016 -- --125025The measurement, monitoring and evaluation of power quality have a great importance for avoiding grid- and device-based problems in the stages of generation, transmission, distribution and consumption of electrical energy. For this purpose, several standards have been set up in order to minimize the effects distorting the power quality of power systems in our country and in the world. In case of investigating these standards, it is mined that voltage dips and voltage imbalances are among the significant technical quality parameters for power systems. In this study, the voltage dips and voltage imbalances occurred in the phase-to-phase effective voltages of a medium-voltage transformer located in an organized industrial zone have been analyzed according to the standards. The number of higher voltage dips and the ratios of excessive voltage imbalances are uncovered and many reasonable assessments are made for them. © 2016 IEEE

Mersin-Gülnar Mevkiinde Meşe ve Dişbudak Topraklarında Karbon ve Azot İçeriğinin Kıyaslanması

iriş: Mersin'in Gülnar ilçesi 1300-1500 rakımlı Küllin mevkiindeki Quercus cerris ve Fraxinus exce/sior'un 0-10 cm derinliğinden alınan toprak örneklerinin pH değerleri, kireç oranları ile karbon ve azot içerikleri kıyaslanmıştır. Doğal orman ekosistemlerindeki toprakların karbon içeriğinin enlem ve yükseklik ile arttığı ve farklı bitki türlerinin topraklarında C/N oranının büyük ölçüde farklılık gösterdiği bilinmektedir. Gülnar Gezende ormanlarında Q. cerris ve F. exce/sior topraklarının C/N oranları bu yükseklikte ilk kez belirlenmiştir. Materyal ve Metot: Topraklarda pH değerleri pH metre, CaCOs düzeyleri Scheibler kalsimetresi, organik içeriği (%C) Anne metodu, toplam içeriği (%N) Kjeldahl metodu ile belirlenmiştir. Bulgular: İki türün toprakları arasında pH ve azot değerlerinde önemli ayrım yok iken, Q. cerris toprağı orta kireçli, F. excelsior toprağı ise az kireçli bulunmuştur. C/N oranları ve karbon içeriği Q. cerris toprağında F. excelsior toprağına oranla oldukça yüksek olup aralarında istatistiksel olarak önemli ayrım vardır (P<0.05). Sonuç: Karbon içeriğinin Quercus cerris toprağında daha yüksek olması mikroklima, bakı, tür özelliği ğibi faktörlere bağlı olarak Quercus organik maddesinin toprağa daha çok karışmasıyla açıklanabilir.iriş: Mersin’in Gülnar ilçesi 1300-1500 rakımlı Küllin mevkiindeki Quercus cerris ve Fraxinus exce/sior’un 0-10 cm derinliğinden alınan toprak örneklerinin pH değerleri, kireç oranları ile karbon ve azot içerikleri kıyaslanmıştır. Doğal orman ekosistemlerindeki toprakların karbon içeriğinin enlem ve yükseklik ile arttığı ve farklı bitki türlerinin topraklarında C/N oranının büyük ölçüde farklılık gösterdiği bilinmektedir. Gülnar Gezende ormanlarında Q. cerris ve F. exce/sior topraklarının C/N oranları bu yükseklikte ilk kez belirlenmiştir. Materyal ve Metot: Topraklarda pH değerleri pH metre, CaCOs düzeyleri Scheibler kalsimetresi, organik içeriği (%C) Anne metodu, toplam içeriği (%N) Kjeldahl metodu ile belirlenmiştir. Bulgular: İki türün toprakları arasında pH ve azot değerlerinde önemli ayrım yok iken, Q. cerris toprağı orta kireçli, F. excelsior toprağı ise az kireçli bulunmuştur. C/N oranları ve karbon içeriği Q. cerris toprağında F. excelsior toprağına oranla oldukça yüksek olup aralarında istatistiksel olarak önemli ayrım vardır (P<0.05). Sonuç: Karbon içeriğinin Quercus cerris toprağında daha yüksek olması mikroklima, bakı, tür özelliği ğibi faktörlere bağlı olarak Quercus organik maddesinin toprağa daha çok karışmasıyla açıklanabilir

Comparison of soil carbon and nitrogen contents of Quercus cerris and Fraxinus excelsior in Mersin-Gulnar region

Background: Soil samples were taken from 0-10 cm depth under Quercus cerris and Fraxinus excelsior at an altitude of 1300-1500 m from Kullin site of Gulnar-Mersin and were compared for their pH, CaCO3, nitrogen % (N) and carbon % (C) contents. Balanced soils in natural forest ecosystems are known to be very rich in carbon content which increases with latitude and altitude and that C/N ratio varies greatly between the soils of different plant species. We determined the values of C/N rates in Q. cerris and F. excelsior soils of Gulnar Gezende forest for the first time at this altitude. Material and Methods: A pH meter and Scheibler calcimeter were used to determine the soil pH and lime contents respectively. Percentage C was determined using Anne method and N % by Kjeldahl method. Results: There was no difference in pH values and percentage nitrogen contents between the two soils. Q. cerris soil was found to have medium levels of CaCO3, while the level of CaCO3 in F excelsior soils was low. C/N rates and carbon contents were higher in Q. cerris soil than F excelsior soil (P&lt;0.05). Conclusions: The higher carbon content of Q. cerris soil can be explained by higher amounts organic matter compared with F excelsior, which might depend on factors such as microclimate and their specific characteristics. © EurAsian Journal of BioSciences

Daily Photovoltaic Power Prediction Enhanced by Hybrid GWO-MLP, ALO-MLP and WOA-MLP Models Using Meteorological Information

Solar energy is a safe, clean, environmentally-friendly and renewable energy source without any carbon emissions to the atmosphere. Therefore, there are many studies in the field of solar energy in order to obtain the maximum solar radiation during the day time, to estimate the amount of solar energy to be produced, and to increase the efficiency of solar energy systems. In this study, it was aimed to predict the daily photovoltaic power production using air temperature, relative humidity, total horizontal solar radiation and diffuse horizontal solar radiation parameters as multi-tupled inputs. For this purpose, grey wolf, ant lion and whale optimization algorithms were integrated to the multilayer perceptron. In addition, the effects of sigmoid, sinus and hyperbolic tangent activation functions on the prediction performance were analyzed in detail. As a result of overall accuracy indictors achieved, the grey wolf optimization algorithm-based multilayer perceptron model was found to be more successful and competitive for the daily photovoltaic power prediction. Furthermore, many meaningful patterns were revealed about the constructed models, input tuples and activation functions

Smart grid projects in Europe: Current status, maturity and future scenarios

The attention on the smart grids and smart grid technologies has grown significantly over the last few years. The analysis made in this study is grounded on the smart grid projects database of the Joint Research Centre (European Commission). The European smart grid projects are analyzed among others in terms of: number, countries, duration and collaboration. Additionally, an analysis is done regarding the annual number of starting and concluded/planned to be concluded projects, the total number of participants per year, the distribution of smart grid applications per stage of development, year and EU country and an overview of the investments in the European smart grid projects is provided. Afterwards a forecast is done regarding the number of projects. As a result of graphical and predictive analyses, many essential inferences are achieved related to the current status and the anticipated short-term trends of smart grid projects.JRC.F.3-Energy Security, Systems and Marke

Short term effects of zinc on some sera biochemical parameters and on tissue accumulation of Clarias gariepinus

Effects of zinc on sera aspartate aminotransferase (AST), alanine aminotransferase (ALT) activities and glucose, total protein and cholesterol levels together with liver, gill, kidney, spleen and muscle accumulation of the metal were studied after exposing Clarias gariepinus to 1.0 and 5.0 ppm Zn over 24, 48 and 96 hours. Highest accumulation of Zn was in liver and spleen tissues in fish exposed to 1.0 ppm and 5.0 ppm Zn respectively after 96 hours of exposure. Sera AST and ALT activities, cholesterol, total protein and glucose levels changed depending on zinc concentration and exposure period. Sera glucose levels increased with increasing exposure periods at both concentrations of zinc. There was also an increase in sera cholesterol and total protein levels at the beginning of the experiment which decreased with increasing exposure. The increase in sera ALT and AST activities were higher in 5.0 ppm Zn compared with 1.0 ppm Zn depending on exposure period. © 2016 Parlar Scientific Publications. All rights reserved

METAL ACCUMULATION IN VARIOUS TISSUES OF Clarias gariepinus EXPOSED TO COPPER, ZINC, CADMIUM AND LEAD SINGLY AND IN MIXTURE

WOS: 000367699500005Accumulation of copper, zinc, cadmium and lead in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus was studied after exposing the fish to 5 ppm Cu, 5 ppm Zn, 1 ppm Cd, 1 ppm Pb and to the same concentrations of their mixture over 1, 7 and 15 days. Atomic absorption techniques were applied in determining tissue metal levels. Highest Cu and Zn accumulation was observed in liver and kidney tissues at all exposure periods whereas highest Cd and Pb accumulation was in gill and liver tissues. The lowest metal accumulation was observed in muscle tissue. Accumulation of these metals in the tissues studied increased compared to control when exposed singly. Tissue accumulation of metals, however, decreased when exposed to metals in mixture compared with single exposures to metals. It was concluded that exposure to these metals in mixture had an antagonistic effect on metal accumulation