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Number of results: 51
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Abstract

Among the elements that compose steel slags and blast furnace slags, metallic precipitates occur alongside the dominant glass and crystalline phases. Their main component is metallic iron, the content of which varies from about 90% to 99% in steel slags, while in blast furnace slags the presence of precipitates was identified with the proportion of metallic iron amounting to 100%. During observations using scanning electron microscopy and X-ray spectral microanalysis it has been found that the form of occurrence of metallic precipitates is varied. There were fine drops of metal among them, surrounded by glass, larger, single precipitates in a regular, spherical shape, and metallic aggregates filling the open spaces between the crystalline phases. Tests carried out for: slags resulting from the open-hearth process, slags that are a by-product of smelting in electric arc furnaces, blast furnace slags and waste resulting from the production of ductile cast iron showed that depending on the type of slag, the proportion and form of metallic precipitates is variable and the amount of Fe in the precipitates is also varied. Research shows that in terms of quality, steel and blast furnace slag can be a potential source of iron recovery. However, further quantitative analyses are required regarding the percentage of precipitates in the composition of slags in order to determine the viability of iron recovery. This paper is the first part of a series of publications aimed at understanding the functional properties of steel and blast furnace slags in the aspect of their destructive impact on the components of devices involved in the process of their processing, which is a significant operational problem.
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Abstract

The aim of the study was to develop new laparoscopic technique for repeated recovery of sheep oocytes. Oocytes were aspirated with specifically designed catheter. It allowed to recover oocytes without ovary damage and to preserve very good quality of recovered oocytes. Fifteen ewes were oocytes donors. Oocytes were collected: one time (group I, n=15), two times (group II, n=15), three times (group III, n=10), four times (group IV, n=5). The endoscope was inserted into the abdominal cavity. Two trockars for putting the manipulators were inserted 15 cm cranial from the udder. Oocytes were collected by aspiration of the follicular fluid from the ovarian follicles. The observed clinical complications were: ovary bleeding and cicatrix at place of needle insertion, the fragmentary adhesion of infundibulum and ovary, adhesions of omentum and peri- toneum near the place where the grasping forceps were inserted and adhesion of ovary and uterus. Ovarian follicles (n=204) were aspirated, 130 (63.8%) oocytes were obtained. Out of 130 obtained oocytes, 112 were qualified for in vitro maturation. The remaining 18 oocytes (13.8%) were rejected due to cytoplasmic changes. The proposed technique allows for the collecting oocytes of good quality that can be used for IMV/IVF techniques and cloning.
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Abstract

The total numbers and biomass of bacterioplankton in two Arctic glacial fjords off west Spitsbergen were studied. Samples were collected from different water depth layers – from the surface to 80–90 m depth. Total bacterial number (TBN), biomass and morphological structure (shape of bacteria) were determined using the acridine orange direct count method. The highest values of TBN and biomass in the water column were found in Kongsfjorden in the stations adjacent to Kongsbreen Glacier, and the lowest values in the outer part of the Krossfjorden. The local maxima of bacterioplankton were observed in water layers around pycnocline. The morphological structure was similar in all samples – the bacteria were dominated by rods (over 65%), followed by cocci (16–20%) and vibrios (11–15%).
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Abstract

The research aimed to use chemical, geochemical, and ecotoxicity indices to assess the heavy metals content in soils with different degrees of exposure to human pressure. The research was conducted in southern Poland, in the Malopolska (Little Poland) province. All metal contents exceeded geochemical background levels. The highest values of the Igeo index were found for cadmium and were 10.05 (grasslands), 9.31 (forest), and 5.54 (arable lands), indicating extreme soil pollution (class 6) with this metal. Mean integrated pollution index (IPI) values, depending on the kind of use, amounted to 3.4 for arable lands, 4.9 for forests, and 6.6 for grasslands. These values are indicative of a high level of soil pollution in arable lands and an extremely high level of soil pollution in grasslands and forests. Depending on the type of soil use, Vibrio fischeri luminescence inhibition was from -33 to 59% (arable lands), from -48 to 78% (grasslands), and from 0 to 88% (forest). Significantly the highest toxicity was found in soils collected from forest grounds.
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Abstract

Suspended matter, phytoplankton and light attenuation were investigated in various North East Greenland, Svalbard and Siberian river mouths in 1992-1994. The amount of mineral suspensions well correlated with freshwater discharge in the case of tidal glacier bays, while such correlation in Siberian rivers and pack ice meltwater was not found. Freshwater phytoplankton species were found in Siberian estuaries only and in two other ecosystems marine and ice phytoplankton species prevailed. The light attenuation connected with freshwater discharge seems to be a key factor limiting primary production in coastal Actic waters in the summer. The amount of glacial suspensions well correlated with the salinity drop in the case of Svalbard, while Siberian river estuaries produced very turbid waters with the suspension loads not correlated to freshwater or depth.
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