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Marcin Pasek and Jacek Olszewski

Abstract

The aim of the article is to present the factors which affect the choice of place of recreation, as well as indicate the preferred forms of physical activity taken up there. The authors also discussed the relationship between distance from open areas and frequency of visits. Moreover, they evaluated current knowledge about the role of the natural environment as a physical recreation space. The research was conducted among a group of 305 physically active individuals (students of the Academy of Physical Education and Sport in Gdańsk), using questionnaires. The respondents defined the role of location in comparison to other motivational factors for a range of physical activities (recreation). They also spoke about their preferred forms of physical activity in the natural environment, compared to the roles of natural and human environments with regard to physical activity. They also provided an answer to the question whether an open area which does not provide respondents with an opportunity to undertake their favoured recreation would remain of interest. The study results demonstrate the unquestionable importance of having access to attractive natural surroundings with respect to physical activity. This allows a relation to be made between leisure in the natural environment and an improvement in the health of the physically active.

Open access

Agnieszka Łukiewska and Jacek Olszewski

Abstract

In this research, we studied the magnetic phase transition by Mössbauer spectroscopy and using vibrating sample magnetometer for amorphous Fe86-xZr7CrxNb2Cu1B4 (x = 0 or 6) alloys in the as-quenched state and after accumulative annealing in the temperature range 600-750 K. The Mössbauer investigations were carried out at room and nitrogen temperatures. The Mössbauer spectra of the investigated alloys at room temperature are characteristic of amorphous paramagnets and have a form of asymmetric doublets. However, at nitrogen temperature, the alloys behave like ferromagnetic amorphous materials. The two components are distinguished in the spectrum recorded at both room and nitrogen temperatures. The low field component in the distribution of hyperfine field induction shifts towards higher field with the annealing temperature. It is assumed that during annealing at higher temperature, due to diffusion processes, the grains of α-Fe are created in the area corresponding to this component. Both investigated alloys show the invar effect and the decrease of hyperfine field induction after annealing at 600 K for 10 min is observed. It is accompanied by the lowering of Curie temperature.

Open access

Jakub Rzącki, Jan Świerczek, Mariusz Hasiak, Jacek Olszewski, Józef Zbroszczyk and Wanda Ciurzyńska

Abstract

As revealed by Mössbauer spectroscopy, replacement of 10 at.% of iron in the amorphous Fe70Mo5Cr4Nb6B15 alloy by cobalt or nickel has no effect on the magnetic structure in the vicinity of room temperature, although the Curie point moves from 190 K towards ambient one. In the early stages of crystallization, the paramagnetic crystalline Cr12Fe36Mo10 phase appears before α-Fe or α-FeCo are formed, as is confirmed by X-ray diffractometry and transmission electron microscopy. Creation of the crystalline Cr12Fe36Mo10 phase is accompanied by the amorphous ferromagnetic phase formation at the expense of amorphous paramagnetic one.

Open access

Marcin Dośpiał, Jacek Olszewski, Marcin Nabiałek, Paweł Pietrusiewicz and Tomasz Kaczmarzyk

Abstract

The paper presents results of microstructure and magnetic properties studies of Nd8.5Tb1.5Fe83Zr1B6 ribbons obtained by melt-spinning technique. The samples were produced using the rapid cooling of liquid alloy on the copper wheel, by applying three different linear velocities 20, 30, and 35 m/s. The microstructure of obtained ribbons was examined using X-ray diffractometry and Mössbauer spectroscopy. Magnetic measurements were performed using LakeShore vibrating sample magnetometer. The microstructure measurements were used for quantitative and qualitative analysis of phase composition. Basing on results of structure studies combined with magnetic measurements, the influence of phase composition on hysteresis loop behavior was described.

Open access

Konrad M. Gruszka, Marcin Nabiałek, Katarzyna Błoch and Jacek Olszewski

Abstract

Thermal treatment, undertaken at just below the crystallization temperature, has led to nanocrystallization and has had a significant impact on the shape of the hyperfine field induction distributions of Fe62Co10Y8B20 alloy and on its soft magnetic properties. In the amorphous ferromagnetic alloys, it is possible to indirectly determine the effect of the structure stresses, resulting from the presence of structural defects, on the soft magnetic properties of these materials. It has been found that a change in the parameters associated with the presence of structural defects affects the shape of the hyperfine field distributions of 57Fe.

Open access

Agnieszka Łukiewska, Jan Świerczek, Mariusz Hasiak, Jacek Olszewski, Józef Zbroszczyk, Piotr Gębara and Wanda Ciurzyńska

Abstract

Mössbauer spectra and thermomagnetic curves for the Fe86− xMxZr7Nb2Cu1B4 (M = Co, Ni, CoCr, and Cr, x = 0 or 6) alloys in the as-quenched state and after the accumulative annealing in the temperature range 600–800 K for 10 min are investigated. The parent Fe86Zr7Nb2Cu1B4 amorphous alloy is paramagnetic at room temperature, and substitution of 6 at.% of Fe by Co, Ni, and CoCr changes the magnetic structure – the alloys become ferromagnetic, whereas replacing 6 at.% of Fe with Cr preserves the paramagnetic state. After the heat treatment at 600 K, the decrease of the average hyperfine field induction, as compared to the as-quenched state, is observed due to the invar effect. After this annealing, the Curie temperature for all investigated alloys decreases. The accumulative annealing up to 800 K leads to the partial crystallization; α-Fe or α-FeCo grains with diameters in the range of 12–30 nm in the residual amorphous matrix appear.

Open access

Aneta Strachecka, Grzegorz Borsuk, Jerzy Paleolog, Krzysztof Olszewski, Milena Bajda and Jacek Chobotow

Abstract

Body-surface chemical compounds were studied in 1-day-old nest workers and foragers both in Buckfast and Caucasian bees. The workers of these two age-castes were sampled twice in each of two consecutive years. Body-surface lipids were determined by means of gas chromatography, with a GCQ mass spectrometer. Protein concentrations and activities on the body surface were examined in bee cuticle rinsings obtained from worker bees according to the methods of Lowry, of Anson, and of Lee and Lin. Protease and protease inhibitor activities were determined. Polyacrylamide gel electrophoresis was performed. Caucasian bees, particularly foragers, had more lipids, but Buckfast bees (two age-castes) had more proteins on their body surfaces. A total of 17 alkane types (C17 - C33), 13 alkene types (C21 - C33), 21 esters (C12 - C32), and a phenol (C14) were detected in both races. Alkene C33 was detected only in Caucasian bees. More alkanes, esters, and phenols were found in Caucasian 1-day-old nest workers and foragers than in these age-castes of Buckfast bees. The protein concentration and protease inhibitor activities were lower in Caucasian bees that had higher protease activities. These values corresponded with specific numbers and widths of the electrophoretic bands.

Open access

Aneta Strachecka, Grzegorz Borsuk, Krzysztof Olszewski, Jerzy Paleolog, Mariusz Gagoś, Jacek Chobotow, Agnieszka Nawrocka, Magdalena Gryzińska and Milena Bajda

Abstract

Three groups of caged bees were fed with sugar syrup (the control), sugar syrup supplemented with amphotericin B (AmB) in a dose of 0.5 mg/ml, and sugar syrup with AmB in a dose of 0.25 mg/ ml. Amphotericin B shortened the life span of the bees and reduced the level of global DNA methylation compared to the control, however, it increased the body-surface protein concentrations. In the hindguts of the bees, there were found AmB deposits. Honeybees appear to be a useful model for studying the side effects of anti-fungal AmB therapy. Among other things, epigenetic changes and senescence acceleration are considered to be the side effects of the therapy.