First principles study of point defects in titanium oxycarbide

We have performed first principles density functional theory calculations to study the formation energy of point defects in TiC, TiO and TiCO compounds. The formation energy of isolated vacancies were obtained for different equilibrium conditions. For binary compounds, we have also calculated the formation energy of antisite defects. It was found that the defect formation energies strongly depend on the chemical environment. Our results show that C vacancies are easily formed in TiC and TiCO. For the TiO compound, Ti vacancies are highly probable to occur and O vacancies are also easily formed under titanium rich atmosphere.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência , Tecnologia, Inovação” – CONC-REEQ/443/EEI/2005, POCTI/CTM/69362/200

Rezultati ispitivanja temperature solarnih modula

A research was made on the influence of the temperature of stationary photovoltaic modules on the production of electricity. The modules are connected in groups, with a total maximum installed capacity of 117.24 kWp. They are mounted on the roof of a non-residential building, located in an uninhabited area. The study covers several typical months in the period from January 2009 to December 2012. The produced electricity changes in the interval 0 - 25.55kWh, for a temperature difference between the photovoltaic modules and the environment in the range of -5 to +30° C.Prikazani su rezultati istraživanja uticaja temperature stacionarnih fotonaponskih modula na proizvodnju energije. Moduli su povezani u grupe, sa ukupnim maksimalnim instalisanim kapacitetom od 117.24 kWp. Postavljeni su na krov zgrade u nenaseljenom području. Istraživanje je izvedeno tokom nekoliko tipičnih meseci, u periodu januar 2009 - decembar 2012. Proizvedena električna energija se menja u intervalu 0 - 25.55 kWh, za temperatursku razliku između fotonaponskih modula i okoline u intervalu od -5 do +30°C