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EN
The objective of the studies included a complex of three reservoirs (upper, middle and lower Arturówek) which play an important recreational role for the residents of the Łódź city and the surrounding areas. The reservoirs were constructed on the Bzura River and are located in the area of the Łódź Hills Landscape Park. The river, the ecological status of which was defined as moderate, has a great influence on the quality of water in the Arturówek reservoirs. A total of 36 planktonic samples were collected in 2011-2013 during spring, summer and autumn seasons. During the studies, the selected physical and chemical parameters were measured. In addition to taxonomic analysis of Cyanobacteria and algae, the analyses of abundance and biomass of phytoplankton and the concentration of microcystins in water were conducted. In 2013, ecohydrological rehabilitation of the Arturówek reservoirs was carried out. Investment works included: removal of the bottom sediments to reduce internal loads, construction of buffer vegetation zones (ecotones) and sedimentation-biofiltration systems to reduce the amounts of pollutants flowing into reservoirs with rainwater. Significant changes in the structure of phytoplankton were observed in 2013. Every year, the disappearance of Cyanobacterial blooms was observed in favor of an increasing contribution of algae.
EN
Proper multidimensional management of perch, common and one of the most abundant species in European freshwaters, is a challenge both from ecological and commercial perspective. However, all activity relating to the management of the perch must be based on good genetic knowledge in order to ensure a purity of species and further conservation of biodiversity. Therefore, in the present study, the mtDNA cytb and D–loop restriction analysis was applied in order to estimate genetic diversity within and among three perch (Perca fluviatilis L.) populations in reservoirs of Central Poland: Sulejów, Próba and Jeziorsko. Two out of nine, and two out of eight restriction enzymes were polymorphic for cytb and D–loop, respectively. Five different haplotypes were detected with the simultaneous occurrence of haplotype 1 in all three populations. Nucleotide diversity values within investigated populations were low (0.003 to 0.02). No significant differentiation (P = 0.248) among populations representing two different catchments of Pilica and Vistula rivers, was observed. The lack of genetic differentiation of perch populations is the first important element for the development of a strategy to regulate the perch in Polish river systems, with simultaneous reduction of fish in eutrophic reservoirs and increase in amount of perch, in sites favorable for fishing and aquaculture.
EN
The ultrasound velocities at constant magnetic filed (cH) and at constant induction (cB), in the 50 mm long strips cut from the Fe64Ni10Nb3Cu1Si13B9 alloy ribbon were measured is as-quenched state and after annealing hot 1h in vacuu, from 100??? C to 550??? C. These velocities were changing from 3200 to 5320 m/s depending on the heat-treatment and magnetic bias field.
EN
Strips cut out from the Fe44Ni30Nb3Cu1 Si13B9 metallic glass alloy ribbons were measured in as-quenched state and after annealing, for 1 h in vacuum in the temperature range from 350 to 500°C. The strips were 50 mm long, 4.5-5.0 mm wide and about 20 žm thick. The resonat-antiresonat method was used. The ultrasound velocities in the strips depending on the heat-treatment and magnetic bias field were changing from about 3500 to 5000 m/s. The maximum values of the magnetomechanical coupling coefficient (km = 0.58) were obtained after annealing at 450°C. After annealing at 470°C the magnetomechanical coupling coefficient dropped to 0.49 because the noncrystalline structure had began to form.
EN
The magnetic field and beat-treatment dependences of the ultrasound velocities at constant magnetic field (CH) and at constant magnetic induction (cB) and magnetomechanical coupling were investigated in Fe62.5Co6Ni7.5Zr6Cu1Nb2B15 alloy strips in an as-quenched state and after annealing above the Curie temperature. After annealing above 350oC (up to 390oC) the magnetomechanical coupling coefficient (k) was three times higher than that for asquenched state (0.10-012), i.e. k = 0.32-0.37. The minimum values of the cH (= 3.6 km/s) were observed after annealing in the temperature range from 350 to 390oC at 75-100 A/m. There are equal or somewhat higher values of bias field for the minimum of the cH than in some other iron-rich amorphous alloys. Effect de was very small for as-quenched samples. When the samples reached the magnetic saturation, the domain structure vanished and then the Hooke's law was valid, i.e. EH = EB = E, where E was then material constant, known as Young's modulus and then the ultrasound velocities are also material constant.
EN
A magnetomechanical coupling in the Fe73.5Cu1Nb1Ta2Si13.5B9 metallic glass strips in as-quenched state and after annealing in vacuum at the temperature range from 100 to 700oC was investigated. The maximum values of the magnetomechanical coupling coefficient (k) were obtained after annealing at 450oC (km = 0.38). Decrease of the magnetomechanical coupling (to 0.2 after annealing at 470oC, to 0.15 after annealing at 500oC, and to zero after annealing at 700oC) and a drop of the saturation magnetostriction (αs) of this alby from (23-25) x 10-6 for as-quenched state and after annealing at 450oC to 10 x 10-6 after annealing at 500oC, and to about 2 x 10-6 after annealing at 550oC is connected with the forming of the nanocrystalline phase. The ultrasound velocities in the strips depending on the heat treatment and magnetic bias field were changing from 3600 to 5300 m/s.
EN
Ultrasound velocities as the functions of the bias magnetic field and annealing temperature were investigated in the Fe72.5Cu1Nb4Sil3.5B9 alloy. The samples were annealed in vacuum for 1 h in the temperature range from 200 to 700oC The maximum changes were observed after annealing at the temperature of 450oC when the magnetomechanical coupling coefficient reached maximum value (k = 0.62). The ultrasound velocities were ehanging from 3.5 to 5.3 km/s depending on the magnetic bias field and the thermal-treatment history.
EN
Magnetic field dependences of the piezomagnetic dynamics and the magnetomechanical coupling on the heat-treatment and magnetic bias field in the Fe62.5Co6Ni7.5Zr6Cu1Nb2B15 alloy strips were investigated. The magnetomechanical coupling coefficient increased from 0.10-0.12 for as-quenched samples to 0.38 after annealing at 390˚C.
12
Content available remote Piezomagnetic parameters of the magnetostrictive materials
EN
Piezomagnetic parameters of magnetostrictive materials and transducers are discussed. Properties of piezomagnetic materials are characterized by piezomagnetic coefficients occurring in the piezomagnetic equations and by the other physical parameters and quantities. A measure of the effectiveness of energy conversion is a magnetomechanical coupling coefficient, which, in addition to mechanical, magnetomechanical and magnetic quality factors, a piezomagnetic dynamics and an electroacoustical efficiency, a vibration amplitude, etc., permits to compare properties of the piezomagnetic materials and transducers. These parameters are useful in both theory and applications of piezomagnetic materials and transducers.
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