Reed woodwind instruments differ in both their geometry (mainly cylindrical or mainly conical) and their excitation mechanism (single or double reed). How much of the resulting sound is due to the single/double reed, and how much to the geometry of the instrument? Measurements done by Almeida et al. (J. Acoust. Soc. Am., 121, 1, 536-546, 2007) show that the flow vs pressure characteristic curve of an oboe reed is not that different from that of a clarinet reed, the only difference probably being due to pressure recovery inside the conical staple. Is it possible to make a single reed mouthpiece for an oboe, while keeping the conical staple, that would still give the oboe its characteristic sound? To find it out, a mouthpiece with the following characteristics was made: A standard clarinet Bb reed can be attached to it, its volume is approximately that of the missing part of the instrument cone, and a standard French oboe staple can be inserted to it, so that it can be inserted in the usual way in any french oboe. In this paper, the first prototype of the mouthpiece is shown. Also, a sound comparison of the oboe sounds played with this mouthpiece and a standard double reed by a professional player is presented.

The world in 21st century is facing the problem of growing energy consumption while the supply of fossil fuels is being reduced. This resulted in the development of research into the use of renewable energy sources and development of new technologies for energy production. In Polish conditions the development of agricultural biogas plants finds its legitimacy in the document developed by the Ministry titled "Trends in agricultural biogas plants in Poland in 2010-2020”. The purpose of this study was to investigate the influence of the weather conditions and the degree of nitrogen fertilisation on yield of reed canary grass (Phalaris Arundinacea L.) and to determine their susceptibility to anaerobic digestion, and usefulness of the production of biogas. Carried out experiments showed that increasing nitrogen fertilisation (from 40 to 120 kg N/ha) linearly increased canary grass green biomass yield from 32 to 46.3 t/ha. However, the highest biogas yield 126 m3/ha was obtained when 80 kg N/ha was applied.

The paper presents results obtained during experiments with constructed wetlands that were built and monitored on the site of a municipal landfill in Southern Poland. The wetland was filled with gravel and rock in which reeds, cattails and willow were planted. A control plot without vegetation was also constructed. Each wetland was loaded with a portion of the leachate generated by the landfill. Measurements of the leachate quality showed very high concentrations of several pollutants. Particularly high concentrations of BOD, COD, nitrogen, and heavy metals were measured. High pollutant levels were probably responsible for the demise of the willows, which were dead within several months of planting. The efficiency of pollution removal with detention time up to 24 h ranged from O to 87% based on decreasing concentration of selected parameters. However, the removal efficiency of the control plot was typically only several percent lower than the removal efficiencies of the plots with vegetation.