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New Photometric and Spectroscopic Observations of the Eclipsing Binary V2080 Cygni

Dimitrov W., Kamiński K., Bąkowska K., Kamińska M. K., Tokarek J., Pawłowski M., Boneva D., Bartczak P., Kwiatkowski T., Schwarzenberg-Czerny A.

Acta Astronomica

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2022

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Vol. 72, No. 1

55--67

EN

We present new spectroscopic and photometric measurements of the eclipsing binary V2080 Cyg. It is a detached system with similar components and an orbital period of 4.9 d. We collected spectroscopic data with two instruments, 1.88 m DDO telescope equipped with Cassegrain spectrograph and 0.5 m PST1 connected to a fiber-fed echell\'e spectrograph. We collected 127 measurements for each component, which significantly increase the number of available radial velocity measurements for the V2080 Cyg system. Obtained masses of the eclipsing components are M1=1.189± 0.007 and M2=1.138±0.007 M☉. We also collected a multicolor photometry. The three-band light curves obtained together with the radial velocity data enabled us to calculate the model of the system. New estimations of the orbital inclination and radii of the components were computed. We obtained as well new times of minima. The O-C diagrams indicate variation, which requires more recent data to be confirmed. The possible existence of a third body could cause a light-time effect in the system. In addition, we analyze the Gaia mission results. V2080 Cyg A has three visual companions. However, according to Gaia parallaxes and proper motions, they cannot be dynamically connected with the eclipsing binary and therefore are background stars.

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Removal of lead(II) ions by an adsorption process with the use of an advanced SiO2/lignin biosorbent

Klapiszewski Ł., Bartczak P., Szatkowski T., Jesionowski T.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 1

48--53

EN

We demonstrate here that lignin can be successfully combined with silica to create a multifunctional material with considerable sorption capabilities. Experiments were carried out in which a silica/lignin hybrid was used for the removal of lead(II) ions from water solutions. Adsorption kinetics were also determined and preliminary regeneration tests were performed. The effectiveness of the adsorption process depends on the following parameters: contact time of adsorbent and adsorbate (equilibrium times: 5 min for concentration 25 mg/L, 10 min for 50 and 75 mg/L, 60 min for 100 mg/L), pH (optimal pH = 5) and adsorbent mass. The kinetics of the adsorption of lead(II) ions on the SiO2/lignin biosorbent are best described by a pseudo-second-order model. Adsorption isotherms of lead(II) ions were also determined. The experimental data were found to be in agreement with the Langmuir model, and the maximal sorption capacity of the adsorbent with respect to lead(II) was 89.02 mg/g.

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Hydroxyapatite as a support in protease immobilization process

Zdarta J., Budzinska K., Kolodziejczak-Radzimska A., Klapiszewski Ł., Siwinska-Stefanska K., Bartczak P., Piasecki A., Maciejewski H., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

633--646

EN

Hydroxyapatite is used as a matrix for immobilization of protease from Aspergillus oryzae by a process of adsorption. The matrix obtained has the surface area of 26 m2/g and particles in the shape of flakes of diameters no greater than 650 nm. The efficiency of the proposed method was confirmed by the Fourier transform infrared spectroscopy, elemental analysis and by analysis of parameters of the pore structure of matrix and products after immobilization. On the basis of the Bradford method it was found that the greatest amount of enzyme (132 mg/g) was immobilized from a solution of initial enzyme concentration of 7 mg/cm3 after 24 h of the process.

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Influence of calcination parameters on physicochemical and structural properties of co-precipitated magnesium silicate

Ciesielczyk F., Bartczak P., Klapiszewski L., Paukszta D., Piasecki A., Jesionowski T.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 1

119--129

EN

Physicochemical properties of different oxide systems depend mostly on the method of their preparation and classification, so the main aim of the study was to obtain the MgO·SiO2 hybrid in an aqueous solution and its calcination under assumed conditions. Research scope included evaluation of the effect of the basic parameters of the calcination process (time and temperature) on the structural properties of the final materials. Products obtained by the proposed method were thoroughly characterized. The chemical composition, crystalline structure, morphology and nature of the dispersion as well as parameters of the porous structure were established. The results of research in a decisive manner confirmed the possibility of designing the properties of inorganic oxide systems such as MgO·SiO2, which will definitively scheduled into potential directions for their use.