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Continuous evolution of the technology determined a sustained increase of the conversion efficiency of PV panels, but nonetheless the most part of the commercial panels have efficiencies no more than 20%. A constant research preoccupation of the technical community involved in the solar energy harnessing technology refers to various solutions to increase the PV module conversion efficiency. Among PV efficiency improving solutions we can mention: solar tracking, optimization of solar cells geometry, enhancement of light trapping capability, use of new materials and so forth.This study is performed to investigate the performance of photovoltaic systems with photo diodes oriented solar tracking system. The result from daily analyses and two season comparative analyses shows, as expected, that in clear days the dual axis tracker photovoltaic system provides the highest performance and great performance in the summer season during higher tilt angle of the sun.

The modified surface during implantation is considered to be an effective strategy to improve high adhesion of bone cell and osseointegration activity. In this paper, the TiO2 barrier oxide Layer has been fabricated by using the ion characteristic of an electrolytic solution, the surface characteristics have been investigated by EDS, XPS, and FE-SEM. From the analysis of the chemical states, phosphorus and calcium were observed in the TiO2 barrier layer, which were penetrated from the electrolyte into the oxide layer during deposit process. In addition, Ca 2p spectrum was identified into two peaks for Ca 2p3/2 and 2p1/2 at 347.4 and 351.3 eV, which are related to hydroxyapatite. Also, P spectrum was confirmed into two peaks for P1/2 and P3/2 levels with binding energy 134.2 and 133.4 eV, respectively. Thus, the incorporated phosphate species were found mostly in the forms of HPO-4, PO-3. From the result of biological evaluation in simulated body fluid (SBF), the apatite morphologies were effective for bioactive property on the modified surface.