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Accurate estimation of wind speed distributions is a challenging task in wind power planning and operation. The selection of convenient functions for describing wind speed distribution is a crucial requisite. In this paper, remarkable bi-parameter Weibull function is presented to estimate the wind energy potential. Weibull parameters based on different six estimation methods, namely graphical, method of moment, energy pattern factor, mean standard deviation, power density methods, and genetic algorithm are evaluated. Besides, the goodness of fit of the estimation methods is investigated via mean absolute error, root mean square error, normalized mean absolute error, Chi-square error, and regression coefficient. To plainly identify the best matching estimation method, Net Fitness test is also presented. Catalca in the Marmara region in Istanbul, Republic of Turkey, is selected to be the underlying site. The experimental results show the effectiveness of the estimation methods in modeling wind distribution but with relatively small differences in terms of performance. However, the genetic algorithm and energy pattern factor accomplish the best and worst matching estimation methods, respectively. [ABSTRACT FROM AUTHOR]

Solar energy solutions that do not require additional space are critical. Noise barriers, which are built in low-value lands next to noise sources, provide effective areas for PV modules. There are many studies on using noise barriers as a sub-structure for photovoltaic systems, providing electricity generation besides noise reduction targets. Photovoltaic noise barrier (PVNB) technology combines noise control measures with renewable energy generation. In this study, it is aimed to develop an integrated design method that embeds solar energy technology in noise protection structures. The method is exemplified in an existing settlement located on the side of the road with heavy traffic. According to local climate and solar data, optimum tilt angles have been determined for annual, semi-annual, seasonal, and monthly periods. Noise barrier alternatives are derived with combinations of different diffraction edge sizes of barrier top and determined optimum inclination angles. The performance of the criteria that affect the PVNB effectiveness for alternatives was calculated through software tools. The energy generation potential of PVNB and its shading in adjacent blocks were calculated with PVsyst 6.7.7. The noise control efficiency of the structure was computed via SoundPLAN 7.2. TOPSIS method, one of the most common multi-criteria decision-making (MCDM) techniques, was used in the evaluation. As a result of TOPSIS, the best PVNB solution in the case study is the alternative that has 3-m and 2-m-wide edges and 58° and 31° tilted edges. In comparison with the current situation, the selected alternative will decrease 44% of the number of receiving points affected by noise and provide 524,804 kWh annual electricity generation. [ABSTRACT FROM AUTHOR]

The Cebeci region is characterized by outcrops of Carboniferous sandstone, including diabase dykes. This region is very important area for aggregate production in Istanbul, Turkey. The aim of this study is to determine the engineering geological properties of sandstones to assess the excavatability, abrasivity and stability of cut slopes in a quarry site. Firstly, the sandstone samples were used to determine their petrographical and mineralogical characteristics. Then, physico-mechanical tests were performed on these samples. In order to determine rock mass properties, scan-line surveys were performed, and the major orientations of discontinuities were analyzed through the stereographic projection technique. Kinematical analyses were also made to determine the potential failures at the quarry site. According to the results obtained, excavatability is changed from easy ripping to hard ripping on sandstones; the carbonated sandstone is less abrasive than other sandstones. Based on the field studies and stability analyses of the cut slopes, optimum slope geometry and necessary support measures, such as wire mesh and rock fall barriers, are suggested. [ABSTRACT FROM AUTHOR]