Possible zoonotic viral threats associated with bats in southern Ukraine

The paper is devoted to evaluation of some bat species inhabiting Ukraine as potential reservoir hosts of highly dangerous viruses including lyssaviruses, MERS-CoV-related coronaviruses, and arboviruses. Repeated catches of bats by a domestic cat were described. Laboratory examination of the caught bats did not detect infection with coronaviruses or arboviruses such as West Nile, tick-borne encephalitis, Crimean-Congo hemorrhagic fever, Tribec and Uukuniyemi viruses. The analysis of the literature showed the possibility of persistence of dangerous viruses among examined bat species. The fact that domestic cats may prey on bats that are potential reservoir hosts of dangerous viruses should be considered as a risk factor for infection of humans and cats with lyssaviruses causing rabies, and infection of humans with coronaviruses that may be associated with severe respiratory diseases.Повідомлення присвячено оцінці ролі деяких видів кажанів, що населяють південь України, як потенційних резервуарів особливо небезпечних вірусів — ліссавірусів, коронавірусів, споріднених з вірусом близькосхідного респіраторного синдрому, та арбовірусів. Описано повторні випадки вилову кажанів свійським котом. Лабораторне обстеження відловлених котом кажанів не виявило наявності у них коронавірусів і таких арбовірусів, як віруси Західного Нілу, кліщового енцефаліту, Кримської-Конго геморагічної гарячки, Трибеч та Уукуніємі. Проведений аналіз даних з літератури свідчить про можливость персистенції небезпечних вірусів серед обстеженних видів кажанів. Той факт, що домашні коти можуть полювати на кажанів як потенційних резервуарів (носіїв) небезпечних вірусів, слід розглядати як фактор ризику для зараження людей та котів ліссавірусами, які викликають сказ, а людей — коронавірусами, що можуть спричиняти важкі респіраторні захворювання

Selfconsistent Model of Photoconversion Efficiency for Multijunction Solar Cells

To accurately calculate efficiencies $\eta$ of experimentally produced multijunction solar cells (MJSCs) and optimize their parameters, we offer semi-analytical photoconversion formalism that incorporates radiative recombination, Shockley-Read-Hall (SRH) recombination, surface recombination at the front and back surfaces of the cells, recombination in the space charge region (SCR) and the recombination at the heterojunction boundaries. Selfconsistent balance between the MJSC temperature and efficiency was imposed by jointly solving the equations for the photocurrent, photovoltage, and heat balance. Finally, we incorporate into the formalism the effect of additional photocurrent decrease with subcell number increase. It is shown that for an experimentally observed Shockley-Read-Hall lifetimes, the effect of re-absorption and re-emission of photons on MJSC efficiency can be neglected for non-concentrated radiation conditions. A significant efficiency $\eta$ increase can be achieved by improving the heat dissipation using radiators and bringing the MJSC emissivity to unity, that is closer to black body radiation rather than grey body radiation. Our calculated efficiencies compare well with other numerical results available and are consistent with the experimentally achieved efficiencies. The formalism can be used to optimize parameters of MJSCs for maximum photoconversion efficiency.Comment: 40th IEEE Photovoltaic Specialists Conference, June 8-13, 2014, Denver, Colorado, III-V Epitaxy and Solar Cells, F30 16

New formalism for selfconsistent parameters optimization of highly efficient solar cells

We analysed self-consistently photoconversion efficiency of direct-gap A3B5 semicon-ductors based solar cells and optimised their main physical characteristics. Using gallium ar-senide (GaAs) as the example and new efficient optimization formalism, we demonstrated that commonly accepted light re-emission and re-absorption in solar cells (SC) in technologically produced GaAs (in particular, with solid- or liquid-phase epitaxy) are not the main factors re-sponsible for high photoconversion efficiency. As we proved instead, the doping level of the base material and its doping type as well as Shockley-Read-Hall (SRH) and surface recombination velocities are much more important factors responsible for the photoconversion. We found that the maximum photoconversion efficiency (about 27% for AM1.5 conditions) in GaAs with typical parameters of recombination centers can be reached for p-type base doped at $2 \cdot 10^{17}$ cm$^{-3}$. The open circuit voltage $V_{OC}$ formation features are analyzed. The optimization provides a significant increase in $V_{OC}$ and the limiting photoconversion efficiency close to 30%. The approach of this research allows to predict the expected solar cells (for both direct-gap and indirect-band semiconductor) characteristics if material parameters are known. Obtained formalism allows to analyze and to optimize mass production both tandem solar cell (TSC) and one-junction SC parameters.Comment: 32 pages, 16 figures, 3 table