Fructification of Stratiotes aloides L. is very rarely recorded at present. In general, there are only one sex representatives in each lake basin, which simply makes generative reproduction difficult. The subfossil seeds of Stratiotes aloides have been found in five localities of biogenic accumulation in northern and central Poland.

Poland is now faced with the task of developing a long-term energy policy for decades to come, a strategy capable of reconciling the security of power supplies as well as effective economic processes, ensuring adequate standards of environmental protection. The process in which fossil fuels are converted into energy carriers of choice is accompanied by the emission of various gas substances which escape into the environment. Later on, those substances accumulate in the atmosphere as greenhouse gases affecting the Earth’s radiation balance – the greenhouse effect. Upsetting the balance between emission levels of those gases and the capacity to convert them in the atmosphere is the reason for climate changes. Sustainable development indices constitute a monitoring tool which makes it possible to create a statistical image of a country from the perspective of a new development paradigm. The most important feature of this index is the capability of comparing values, enabling to determine the position of a given object with reference to other objects. The article analyses 8 indexes of sustainable development in terms of using biomass for power generation purposes. The analysis was performed to include three social order indices, two economic indices and one environmental order index. It was concluded that the use of biomass in power generation can reduce the emission of greenhouse gasses significantly at several stages: the emission can be eliminated from the biological process of biomass conversion, storage and it can also be reduced during transportation.

The objective of the paleoecological studies undertaken in the "Klocie Ostrowieckie" reserve was mainly to reconstruct the subfossil mire vegetation at a local and regional scale. This article presents the results of palynological and plant macroremain analyses of this site, and belongs to the first published studies of such a type, made in the Drawieński National Park. Based on our studies, five phases in the history of the mire development were determined. The most pronounced feature of that history, was a decline of Cladietum marisci clearly concurrent with a strong yet puzzling expansion of pine stands occurring approximately 1000 years ago.

In this work, the effect of heat transfer during explosive welding (EXW) and post-processing annealing on the microstructural and chemical composition changes have been thoroughly analysed using scanning and transmission electron microscopies and X-ray synchrotron radiation. Several combination of explosively welded metal compositions were studied: Ti with Al, Cu with Al, Ta or stainless steel, stainless steel with Zr or Ta and Ti with carbon steel. It was found that the melted metals exhibit a strong tendency to form brittle crystalline, nano-grained or even amorphous phases during the solidification. For all analysed metal combinations most of the phases formed in the zones of solidified melt do not appear in the equilibrium phase diagrams. Concurrently, the interfacial layers undergo severe plastic deformation forming nano-grained structures. It has been established that these heavily deformed areas can undergo dynamic recovery and recrystallization already during clad processing. This leads to the formation of new stress-free grains near the interface. In the case of low temperature and short time post processing annealing only the melted zones and severely deformed layers undergo recovery and recrystallization. However, drastic changes in the microstructure occurs at higher temperature and for longer annealing times. Applying such conditions leads to diffusion dominant processes across the interface. As a consequence continuous layers of intermetallic phases of equilibrium composition are obtained.

We present the last millennium of history of a peatland located in northern Poland. Our results are based on two replicate monoliths taken from a Baltic raised bog. We applied a high-resolution approach and radio car bon dating to the peat material to obtain a de tailed palaeoenvironmental reconstruction. To reconstruct past peatland moisture, we used three prox ies: testate amoebae, plant macrofossils and pollen. Despite different peat accumulation and extensive hiatus in the formerly studied core, both monoliths show a similar pattern of changes. However, the core from this study provides us with more detailed data on S. fuscum disappear ance which correlates well with the data from the other Baltic bog, S³owiñskie B³oto. Our re search shows that pris tine Bal tic bogs can be dated to AD 1350. Słowiñskie Błoto palaeohydrology confirms AD 1300 as the beginning of the hydrological disturbance. In the case of the Stążki and Słowiñskie Błoto bogs, the Little Ice Age (LIA) is recorded between AD 1500 and AD 1800. However, this climatic change might have been blurred by human impact. In the case of the Baltic bogs, their reference virgin state can be dated to AD 1200. After this date, we observed in creasing human impact and climatic in stability connected with the LIA. However, between AD 1800 and 1900, bogs were wet, most possibly due to climatic forcing. This fact suggests that despite human impact, recent peat deposits can still reflect climate. Our research provided in formation related to the time of existence, location and characteristics of the natural/pristine state. High-resolution peatland palaeoecology is crucial for restoration activities, e.g., rewetting and environmental management. The palaeohydrological context (supported by other proxies) of the last 1000 years provides a reliable answer to the question: ‘To rewet or not to rewet?’

Multilayered composites based on light metals are promising materials in many applications. In the present work the 15-layered clad, composed of alternately stacked of Ti(Gr.1) and AA1050-H24 alloy sheets of 1 mm thick has been investigated with respect to determination of the kinetic of the Al3Ti phase growth. The defect-free multilayered composite was successfully formed by explosive welding technology. Then EXW samples were modified via annealing at the temperature of 600oC in closed die under pressure of 44 MPa for various times ranged between 1 and 10 h. Transmission and Scanning Electron Microscopy examinations were conducted in order to study the kinetic of the elements migration across the interfaces between the layers of the Al/Ti composite. The macro-scale observations of samples after EXW revealed that wavy interfaces were always formed in layers near the explosive charge. The increase of the distance from the top surface leads to flattening of the interface with very thin reaction layer between Al and Ti sheets. During annealing the kinetic of the Al3Ti phase growth is similar near all interfaces and coincides with data from other works. It was found that despite the loading after 10 h of annealing still only small part of Al-sheets undergoes dissolution and the width of the reaction layer does not exceed 5-8 µm.

The paper has presented the results of theoretical studies and experimental tests of the plastic deformation of multi-layered Ti/Al/Mg specimens. Theoretical studies were carried out using the Forge2011® computer program. Physical modeling, on the other hand, was performed using the Gleeble3800 simulator. Cuboidal specimens were cut off from the plates obtained in the explosive welding method. Based on the obtained investigation results it has been found non uniform deformation of the particular layer as a result their different value of flow stress.