Functional Materials, 2018, том 25
http://dspace.nbuv.gov.ua:80/handle/123456789/150314
2024-03-28T20:28:49ZProperties of MnO doped graphene synthesized by co-precipitation method
http://dspace.nbuv.gov.ua:80/handle/123456789/157452
Properties of MnO doped graphene synthesized by co-precipitation method
Ilman Nur Sasongko, M.; Poppy Puspitasari; Sukarni; Cepi Yazirin
MnO doped graphene specimens were synthesized using a simple and cost-effective method, i.e. co-precipitation. The characterization of specimens was done through various techniques, such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR). Single phase pattern on [222], crystallite size, and d-spacing were confirmed by XRD results. The nanostructure morphology was observed using SEM. FTIR showed the shifted peaks and changes in the intensity of molecular bonds of the material. The specimens were sintered for 1 h at various temperatures of 500 °C, 600 °C, and 700 °C. The XRD characterization showed that sintering at 700 °C resulted in MnO and GO peaks with the highest intensity, but the specimen sintered at 600 °C had the best grain size of 70.39 nm. The morphology characterization by SEM showed a change of shape from triangle to nanosphere with agglomeration. The results of FTIR showed that the shifts in C-O and Mn-O groups were followed by an increase in N-H, C-H, C=O, C-O, and Mn-O. The results of this study suggest that single-phase MnO doped graphene was successfully synthesized using the co-precipitation method.
2018-01-01T00:00:00ZMethod of obtaining an organic polycrystalline scintillator for detecting beta-radionuclide sources in natural waters
http://dspace.nbuv.gov.ua:80/handle/123456789/157451
Method of obtaining an organic polycrystalline scintillator for detecting beta-radionuclide sources in natural waters
Andryushchenko, A.Yu.; Belikov, K.N.; Galunov, N.Z.; Martynenko, E.V.; Lazarev, I.V.; Polupan, Ya.I.; Tarasenko, O.A.
The method of producing an organic polycrystalline scintillator with two-stage sorbent filled holes for detecting beta-emitting source of <f2m^>90Sr in natural water is proposed. That confirms that synthetic hydroxylapatite is the optimal sorbent to solving the problem. For the polycrystalline scintillator of p-terphenyl doped by 1,4-diphenylbutadiene-1,3 which has the holes filled with hydroxylapatite as a sorbent, the efficiency of detecting beta particles of 90Sr isotope sorbed from the water sample reaches 90 %.
2018-01-01T00:00:00ZProduction of submicron Al₂O₃ powders by electrochemical dissolution of aluminum in the presence of nitric acid
http://dspace.nbuv.gov.ua:80/handle/123456789/157450
Production of submicron Al₂O₃ powders by electrochemical dissolution of aluminum in the presence of nitric acid
Balabanov, S.S.; Drobotenko, V.V.; Permin, D.A.; Rostokina, E.Ye.; Boldin, M.S.; Murashev, A.A.
A cost-effective and easily scalable method for the synthesis of ultrapure submicron alumina powders with a narrow particle size distribution and high sinterability is proposed. Aqueous solutions of aluminum hydroxide nanoclusters obtained by AC electrochemical dissolution of aluminum metal in the presence of nitric acid were used as a precursor. Hot pressing and vacuum sintering were used to evaluate the possibility of obtaining Al₂O₃ optical ceramics from synthesized powders.
2018-01-01T00:00:00ZSimulation of the insulating properties of two-layer material
http://dspace.nbuv.gov.ua:80/handle/123456789/157449
Simulation of the insulating properties of two-layer material
Dadashov, I.F.; Kireev, A.A.; Kirichenko, I.K.; Kovalev, A.A.; Sharshanov, A.Ya.
Mathematical simulation of the process of diffusion of liquid vapors through a binary layer consisting of a light granular material and a layer of gel applied on its surface is shown. Using the proposed model the coefficient of octane evaporation rate reduction on the onset of the stationary mode was determined, and the time for reaching this mode was estimated. For a gel layer with thickness of 2 mm and a layer of foam glass with thickness of 5 cm, the evaporation rate of octane is reduced by more than 100 times compared with the evaporation rate from the free surface of the liquid. Two-layer insulating materials are proposed to use for elimination of emergencies associated with the spill of toxic and flammable liquids, as well as for extinguishing fires involving flammable liquids.
2018-01-01T00:00:00Z