The study of groundwaters was carried out in two different forest ecosystems of Słowiński National

Park: Vaccinio uliginosi-Betuletum pubescentis and Empetro nigri-Pinetum in the period of 2002-2005. Differences were found in the position of the groundwater table and in the concentrations of nitrogen and phosphorus

compounds in the investigated forest associations. In the Vaccinio uliginosi-Betuletum pubescentis association

the groundwater table was found on average at a depth of -73.3 cm, while in Empetro nigri-Pinetum at -90.2

cm. No statistically significant effect of precipitation on the position of the groundwater table was found in

this study. Statistical calculations (U Mann-Whitney test) for groundwaters in the analyzed forest associations

showed statistically significant differences in the dynamics of concentrations of total nitrogen (T-N), organic

nitrogen (Norg.), nitrate nitrogen (N-NO3

), total phosphorus (T-P), organic phosphorus (Porg.) and the level of

groundwaters.

This work concerns measurements of the radiant intensity emitted by LEDs. The influence of selected factors and parameters on the final measurement result are discussed. The research was conducted using two type of detectors: light meter and CCD camera, to compare the degree of influence of these parameters depending on the measurement instrument used.

The concentrations of Cu, Mn, Ni and Zn in the soil and litterfall, as well as influx of the elements to the soils with litterfall were studied in a mixed beech-pine-spruce stand in northern Poland during the years 2007–2009. Annual influx of litterfall to the soil amounted from 3.234 to 4.871 t/ha. Beech, pine and spruce litterfall contributed in total litterfall in 50.8−70.1%, 11.4−11.9% and 1.6−24.0% respectively. The following average annual concentrations of heavy metals in total litterfall during the 3-year study period were noticed: 2469.3–3469.2 mg Mn/kg, 153.6–160.8 mg/kg Zn, 8.0–14.3 mg Ni/kg and 5.0–6.8 mg Cu/kg. In general, the concentrations of Mn and Cu were higher in beech litterfall in comparison to pine and spruce. The contents of Zn and Ni in beech, pine and spruce litterfall were comparable. Annual influx of metals to the soil with litterfall was: 10341.6–14422.4 g/ha Mn, 460.3–748.1 g/ha Zn, 37.4–66.6 g/ha Ni and 20.2–31.8 g/ha Cu. The fluxes were higher for Mn, Zn and Ni, and comparable for Cu in relation to those observed in other beech, pine, spruce and mixed stands in northern Europe.

The oxygen and thermal conditions in Lake Ińsko were examined in years 1999-2000. Lake Ińsko is one of a dynamictic type and its waters are mixed twice a year. This lake has a strong thermal and oxygen stratification. The oxygen conditions in the lake are very good because the total deficiency of oxygen appears only in summer, on the depth below 30 m, and only in the areas where the influence of town of Ińsko is the strongest. During autumn and winter circulation the concentration of oxygen near the bottom reaches 5 mg O2 dm-3. The concentration of oxygen in the water reflects favorable conditions of biomass production, including primary production of phytoplankton in epilimnion of Lake Ińsko. The intensive development of algas has considerably influenced the transparency of water. On the background of vertical thermal and oxygen differences during the summer there were also differences in the reactions of water.

The paper presents the results of study on heavy metals in needles of Pinus sylvestris in selected pine forests in Słowiński National Park. It was evidenced that heavy metal contents (Zn, Cu, Mn and Fe) in needles of Pinus sylvestris varied depending on the metal, the age of the needles and the humidity of a forest complex. Variation coefficients of such metals remained at the level of: 13-30% (Zn), 3-6% (Cu), 13-34% (Mn) and 12-30% (Fe) depending on the age of the needles. In the case of Zn, Mn and Fe higher concentrations of researched metal were found in the 2-year-old needles than in 1 year old needles, and in the case of Cu in 1 year old needles than in 2-year-old needles. The increase of zinc concentration found in 1-year-old needles after rainfall sums was (Bw, r = 0.67, p < 0.05, n = 24) and (Bśw, r = 0.39, p < 0.05, n = 24) in 2-year-old needles. The content of the above mentioned metals in needles of dry coniferous forests (Bs), fresh coniferous forests (Bśw) and humid coniferous forests (Bw) of the ground cover constitute the following decreasing series: Mn(323.8) > Fe(103.4) > Zn(65.5) > Cu(5.9).

The article is an interpretation of the teaching of Pope Francis on „the joy of the Gospel”. An analysis of the Exhortation Evangelii gaudium has led to the conclusion that the joy of the Gospel according to Francis is a Christian virtue. Traditional the-ology distinguishes two categories of virtues: theological and cardinal. Benedict XVI points out to a new group of virtues: ecclesial ones. According to Francis the basis of this joy is the adoption and proclamation of the Gospel. Its source is the person of Jesus Christ. Through the union with Him, the human person is liberated from alien-ation, selfishness and slavery. The joy of the Gospel is being revealed in the dialogue which is an exchange of gifts between individual persons. It takes place in an en-counter which gives an opportunity to know one another, God and man. The ecclesial context of joy is presented in the personal opening to Christ and in the opening of the Church to all people. Christian joy, based on Pope Francis’ concept of the joy of the Gospel, can be qualified as one of the ecclesial virtues.

This paper presents the results of study on heavy metals in soil and in herbaceous plants in selected pine forests in Słowiński National Park. The heavy metals, such as Zn, Cu, Mn and Fe were studied. Concentrations of zinc in tested soil are strongly and very strongly related to manganese and copper content (r = 0.57 do r = 0.98, p < 0.05). Moreover, the soil moistening has vital impact on copper content in the plants of the ground cover. It was also found that moss in comparison to other forest plants captures higher volume of zinc and copper. The content of the above mentioned metals in the plants of dry coniferous forests (Bs), fresh coniferous forests (Bśw) and humid coniferous forests (Bw) of the ground cover constitute the following decreasing series: Mn(438.1) > Fe(98.6) > Zn(35.2) > Cu(3.5).

The paper presents results from social research on the Polish business representatives potentially interested in using the floating buildings. The main purposes of the study were to assess the level of knowledge about floating buildings and diag-nose stimulants and inhibitors of their development in the hotel, catering, and water tourism industry.

Combining the quantitative and the qualitative methodology, research was conducted using an on-line survey (CAWI)and Focused Group Interviews (FGI). Both involved a non-probabilistic, purposive sampling to reach a specific subgroup of the industry: owners or employees of catering, hotel or water tourism companies having or considering having a floating building. The group included both new and long-standing companies using facilities on water or with direct and indirect access to the water.

The study identified stimulating and inhibitory factors broken down into internal (context-independent) and external (context-dependent) conditions. Results show that in Poland floating commercial buildings are a niche topic but also a de-velopable one. Although 71% of the respondents notice difficulties resulting from the insufficient infrastructure and 66.5% of them indicate the lack of legal regulations, they also see the potential of floating buildings: depending on the industry, from 90 to 95% respondents find them “definitely attractive” or “rather attractive”. The most common reason for rejecting floating development is the lack of attractive moorages in the area (43.5% answers).

Materials based on cast irons are often used for protection against wear. One of the methods of creating protective surface with cast iron structures is hardfacing. The application of hardfacing with self shielded flux cored wire with high carbon content is one of the economical ways often used to protect machinery parts exposed to both abrasion and erosion. The wear resistance of hardfacings depends on their chemical composition, structure obtained after hardfacing, parameters of depositing process and specific conditions of wear. As the base material in the investigation the steel grade S235JR was used. The wear behavior mechanism of hardfacings made with one type of self shielded flux cored wire and different process parameters were evaluated in this paper. Structures obtained in deposition process were different in hardness, amount of carbides and resistance to wear with two investigated impingement angles. The erosion tests showed that impingement angle 30° gives lower erosion rate than angle 60°.

This work deals with the effect of austempering temperature and time on the microstructure and content of retained austenite of a selected cast steel assigned as a material used for frogs in railway crossovers. Bainitic cast steel was austempered at 400°C, 450°C and 500°C for two selected times (0.5 h, 4.0 h) to study the evolution of the microstructure and retained austenite content. The microstructure was characterized by optical microscopy, X-ray diffraction analyses (XRD), and hardness tests. Phase transformations during and after austempering were determined by dilatometric methods.

The increase in isothermal temperature causes an increase in time to start of bainitic transformation from 0.25 to 1.5 s. However, another increase in temperature to 500°C shifts the incubation time to as much as 11 s. The time after which the transformations have ended at individual temperatures is similar and equal to about 300 s (6 min.). The dilatation effects are directly related to the amount of bainite formation. Based on these we can conclude that the temperature effect in the case of cast steel is inversely proportional to the amount of bainite formed. The largest effect can be distinguished in the case of the sample austempered at 400°C and the smallest at 500°C. Summarizing the dilatometric results, we can conclude that an increase in austempering temperature causes an increase in austenite stability. In other words, the chemical composition lowers (shifts to lower temperatures) the range of bainite transformation. It is possible that at higher austempering temperatures we will receive only stable austenite without any transformation. This is indicated by the hatched area in Figure 4b. This means that the heat treatment of cast steel into bainite is limited on both sides by martensitic transformation and the range of stable austenite. The paper attempts to estimate the content of retained austenite with X-ray diffraction.