No abstract

In this paper, the differences in mechanical strength tested during the static tensile and compression test of Scots pine (Pinus sylvestris L.), European larch (Larix decidua) and Norway spruce (Picea abies) wood exposed to continuous soaking in water with a salinity of 7‰ were determined. The value of salinity corresponded to the average salinity on the Polish Baltic coast. This paper also aimed to examine the content of mineral compounds absorbed during four cycles of two weeks each. The essence of the statistical research was to identify the effect of the mineral range compounds and salts depending on the mechanical strength of the wood. Based on the results of the experiments, it can be concluded that the medium used has a specific effect on the wood species’ structure. The effects of soaking on the wood parameters depend obviously on the type of wood. A tensile strength test of pine, as well as the tensile strength other species, was enhanced by incubating it in seawater. A native sample’s initial mean tensile strength was 82.5 MPa, which increased to 94.8 MPa in the last cycle. It was found that the larch wood had the lowest tensile strength difference (9 MPa) of the woods studied in the current study. Four to six weeks of soaking was necessary to notice an increase in tensile strength.

This article aims to give an overview of tourism at the time of the global crisis caused by the COVID-19 pandemic. In order to assess the influence of the COVID-19 pandemic on European countries, the Systemic Literature Review (SLR) as well as Our World in Data (2021) and EUROSTAT (2021) secondary data were used. In order to group countries with respect to changes taking place in tourism, Ward’s cluster analysis was applied. After verifying the available data, 31 European countries were eventually selected for the analysis. The application of Ward’s method led to four groups of countries being created that are most similar in terms of changes in the tourism sector between 2019 and 2020. The first cluster comprised eight countries with the highest average rate of restrictiveness. On the other hand, this group recorded the lowest rate of changes concerning arrivals by air transport, which was on average 70.32%. The second group comprised 13 countries. In this cluster, the average change in the number of overnight stays and arrivals at tourist resorts was the lowest in comparison with other clusters. The third cluster comprised four countries where the change in arrivals by air transport was the highest, with an average decrease of 81.76%. The fourth group comprised six countries. The average change in the occupancy of hotel rooms and similar overnight accommodation facilities, as well as arrivals at tourist resorts, was the highest in comparison with other clusters. In addition, the countries were characterized by a relatively high decrease in the number of arrivals by air transport, but a relatively low average rate of restrictiveness.

The aim of this study was the investigation of the effect of growth conditions of energy willow (Salix viminalis L.) on its physical and chemical parameters towards lignocellulosic biofuels. This work is linked to the global trend of replacing fossil fuels (coal, oil, natural gas) with energy and renewable fuels. This energy transition is dictated by the reduction of the human-induced greenhouse effect (to the greatest extent by industrial development). Changing from traditional to renewable energy sources results in industry becoming less dependent on fuels whose sources are beginning to run out, and in energy processing being broken down into smaller sectors with greater flexibility to change and less susceptibility to failure. The use of lignocellulosic raw materials such as wood, straw, food industry waste, wood, and post-consumer products such as old furniture for energy purposes allows the use of substances which bind the greenhouse gas carbon dioxide in their cellular structure during growth. In order to optimise the costs of producing such energy and minimise its impact on the environment, these plants should be located as close as possible to the source of raw materials. One of the most important characteristics for the profitability of energy production from woody biomass is a high biomass yield. For this purpose, the raw material used for this study was energy willow (Salix viminalis L.) seedlings, which are often used for energy crops. Due to the moisture-loving nature of the substrate, the effect of the addition of the active substance prednisonum as a catalyst for water adsorption from the substrate was investigated. In order to determine the substances formed during the thermal decomposition of energy willow (Salix viminalis L.) wood, a pyrolysis process was carried out at 450 °C using pyrolysis gas chromatography mass spectrometry (PY/GC-MS).

The paper determines the effect of selected cultivation technologies, including production chain energy inputs (growing, harvest, heap forming) on greenhouse gas emissions (GHGs) to the atmosphere. The data for the study was collected from 13 actually operating family farms ranging in size from 2 to 13 ha, located in the Podlaskie voivodship (Poland). GHG and ammonia (NH3) emissions from natural and mineral fertilisation as well as GHGs from energy carriers in a form of fuels (ON) were estimated. The average GHG emissions from the sources analysed were 1848.030 kg·CO2eq·ha−1 and 29.492 kg·CO2eq·t−1 of the green forage yield. The average NH3 emissions per hectare were 15,261.808 kg NH3 and 248.871 kg NH3·t−1 of yield. The strongest impact on the environment, due to the GHG emissions to the atmosphere, thus contributing to the greenhouse effect, is due nitrogen fertilisation, both mineral and natural. On average, in the technologies under study, 61% of the total GHG emissions came from fertilisation. The GHG emissions were correlated with the energy efficiency, calculated at the previous research stage, of the production technologies applied. There is a negative correlation (r = −0.80) between the features studied, which means that the higher the energy efficiency of the silage maize plantations, the lower the air pollution emissions in a form of the GHGs from the sources under study. It is so important to prevent environmental degradation to continue, conduct in-depth, interdisciplinary research on reducing the energy consumption of crop production technologies and striving to increase energy efficiency.