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Abstract

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.
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Abstract

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.
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Abstract

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.
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Abstract

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).
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Abstract

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).
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Abstract

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°.
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