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Number of results: 4
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Abstract

The hierarchical structure of InSe<β-CD<FeSO4>> composition with 4-fold grade expansion was synthesized with the intercalation-deintercalation technique. Electrical properties of the structure obtained were examined using impedance and thermostimulated current spectroscopy methods. Influence of temperature, static magnetic field and illumination on electrical properties of the synthesized compound was investigated. Changes in the impurity spectrum of the expanded hierarchical structure were analyzed and extraordinary magneto- and photoimpedance behavior of InSe<β-CD<FeSO4>> at room temperature was explained.

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Authors and Affiliations

T. Popławski
I. Bordun
A. Pidluzhna
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Abstract

The purpose of the presented research is to analyse possible methods of thickening of the Microcystis aeruginosa (Kützing) Kützing cyanobacteria using the obtained concentrate as a biomass for the production of energy carriers and bio-logically valuable substances. Method of cyanobacteria thickening under the action of electric current and in the electric field, as well as the method of coagulation–flocculation and gravity thickening, was experimentally investigated in lab-scale conditions. Electrical methods didn't show positive results for the Microcystis aeruginosa thickening, despite the re-ports of their potential efficiency in a number of previous studies. The high efficiency of the method of coagulation–flocculation and gravity thickening of Microcystis aeruginosa suspensions was obtained. The optimum concentrations of industrial polymeric coagulants and flocculants for the thickening of Microcystis aeruginosa suspensions were defined in the range of about 10 ppm for the coagulants and about 1 ppm for the flocculants. Negative effect of the previous cavitational treatment of the diluted suspensions of Microcystis aeruginosa on the effectiveness of the coagulation–flocculation and gravitational thickening was confirmed experimentally. Hydrodynamic cavitation should be recommended to use after the thickening as the next step of processing of concentrated suspensions of Microcystis aeruginosa to achieve maximum extraction of energy carriers and biologically valuable substances.

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Authors and Affiliations

Myroslav Malovanyy
Volodymyr Zhuk
Volodymyr Nykyforov
Igor Bordun
Iurii Balandiukh
Galyna Leskiv
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Abstract

The article comprises synthesis of magnetically susceptible carbon sorbents based on bio raw materials – beet pulp. The synthesis was performed by one- and two-step methodology using FeCl3 as an activating agent. X-ray diffraction methods showed an increase in the distance between graphene layers to 3.7 Å in biocarbon synthesized by a two-step tech-nique and a slight decrease in inter-graphene distance to 3.55 Å for biocarbon synthesized by an one-step technique. In both magnetically susceptible samples, the Fe3O4 magnetite phase was identified. Biocarbon synthesized by a two-step technique is characterized by a microporous structure in which a significant volume fraction (about 35%) is made by pores of 2.2 and 5 nm radius. In the sample after a one-step synthesis, a significant increase in the fraction of pores with radii from 5 to 30 nm and a decrease in the proportion of pores with radii greater than 30 nm can be detected. Based on the analysis of low-angle X-ray scattering data, it is established that carbon without magnetic activation has the smallest specific area of 212 m2∙сm–3, carbon after one-stage synthesis has a slightly larger area of 280 m2∙сm–3, and after two-stage synthesis has the largest specific surface area in 480 m2∙сm–3. The adsorption isotherms of blue methylene have been studied. Biocarbon ob-tained by two-step synthesis has been shown to have significantly better adsorption properties than other synthesized bio-carbons. Isotherms have been analysed based on the Langmuir model.

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Authors and Affiliations

Christina Soloviy
ORCID: ORCID
Myroslav Malovanyy
ORCID: ORCID
Ihor Bordun
ORCID: ORCID
Fedir Ivashchyshyn
ORCID: ORCID
Anatoliy Borysiuk
Yuriy Kulyk
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Abstract

In this work, we present findings on the syntheses and study of properties of InSe<PTHQ> nanohybrid. The introduction of guest component in GaSe matrix leads to an increase in inhomogeneities, which is clearly confirmed by the strengthening of the low-frequency horizontal branch of Nyquist diagrams. A constant magnetic field counteracts this effect and changes the behavior of the impedance hodograph at low frequencies to the opposite. Illumination leads to a colossal increase in quantum capacitance, which is clearly demonstrated in the Nyquist diagram. For the synthesized InSe<PTHQ> nanohybrid the interesting behavior of the current-voltage characteristic is reported. As a result of studies of the synthesized InSe<PTHQ> nanohybrid the effect of “negative capacity” is observed, the magnitude of which can be controlled by the electric field. Based on the constructed impedance model and proposed N-barrier model, the physical mechanisms of the investigated processes are suggested.
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Authors and Affiliations

Fedir Ivashchyshyn
1
ORCID: ORCID
Vitaliy Maksymych
2
ORCID: ORCID
Dariusz Calus
1
ORCID: ORCID
Myroslava Klapchuk
2
ORCID: ORCID
Glib Baryshnikov
3
ORCID: ORCID
Rostislav Galagan
3
ORCID: ORCID
Valentina Litvin
3
ORCID: ORCID
Piotr Chabecki
1
ORCID: ORCID
Ihor Bordun
1 2
ORCID: ORCID

  1. Czestochowa University of Technology, Al. Armii Krajowej 17, Czestochowa, 42-200, Poland
  2. Lviv Polytechnic National University, Bandera Str. 12, Lviv, 79013, Ukraine
  3. Bohdan Khmelnytsky National University, blvd. Shevchnko 81, 18031, Cherkasy, Ukraine

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