The paper presents the results of the energy analysis of the conversion of solar radiation energy into electrical energy in Polish weather conditions. The effect of sunlight and working temperature on the photovoltaic module on its power curve P = f(U) is shown. STC and NOCT conditions are described for which the manufacturers specify the parameters of the photovoltaic modules. The manufacturers of photovoltaic panels should give the PPV = f(E) characteristic for the different values of the operating temperature of the modules. An analysis of the economic efficiency of a photovoltaic power plant investment of 1 MWp taking the current legal regulations for the three variants into account was presented. Variant I – the investor benefits from the support of public aid of operational only, Variant II – the investor benefits from the support of public aid for investment in the amount of PLN 1 million, Variant III – the investor benefits from the support of public aid for investment in the amount of PLN 2 million. For all variants, indicators for assessing the economic effectiveness of the investment and the value of the auction price from the maximum price to the price at which the project loses its profitability are determined.

The paper presents the research studies carried out on the reverberation time of rooms, in terms of theoretical aspects and applicability potentials. Over the last century a very large number of scientists have been attempting to work out models describing the reverberation time in enclosed rooms. They have also been trying to apply these models for the description of various acoustic parameters of the interior, i.e. the intelligibility of speech, clarity, articulation, etc. In fact, all these models are based on the Sabine’s statistical method. The paper presents the work of the scientists working on this problem, together with prospective applicability potentials. Such a review may be helpful for researchers, designers or architects involved in the discussed subject.

Studies of electrical properties, including noise properties, of thick-film resistors prepared from various resistive and conductive materials on LTCC substrates have been described. Experiments have been carried out in the temperature range from 300 K up to 650 K using two methods, i.e. measuring (i) spectra of voltage fluctuations observed on the studied samples and (ii) the current noise index by a standard meter, both at constant temperature and during a temperature sweep with a slow rate. The 1/f noise component caused by resistance fluctuations occurred to be dominant in the entire range of temperature. The dependence of the noise intensity on temperature revealed that a temperature change from 300 K to 650 K causes a rise in magnitude of the noise intensity approximately one order of magnitude. Using the experimental data, the parameters describing noise properties of the used materials have been calculated and compared to the properties of other previously studied thick-film materials.

Populations of Antarctic hairgrass Deschampsia antarctica Desv. from King George Island exhibit variation in many traits. The reason for that is not evident and could be addressed to variable environmental conditions. Obviously, phenotypic variation could be due to stable or temporal changes in expression pattern as the result of adaptation. Stable changes could be due to mutations or site DNA methylation variation that modified expression pattern. Recently, metAFLP approach was proposed to study such effects. A variant of methylation sensitive AFLP (Amplified Fragment Length Polymorphism), based on the isoschizomeric combinations Acc65 I/ Mse I and Kpn I/ Mse I was applied to analyze the sequence and site DNA methylation differences between two D. antarctica populations exhibiting morphological dissimilarities. Both DNA sequence mutations and site methylation pattern alternations were detected among and within analyzed populations. It is assumed that such changes might have originated as the response to environmental conditions that induced site methylation alternations leading to phenotypic variation of D. antarctica populations from South Shetland Islands.