12 research outputs found
Activated Carbons from Co-Mingled Liquid
Data on a synergetic phenomena of the components of the co-mingled solid and liquid wastes occurs during their thermolysis were used for the development of the co-activation approach to wastes recycling. Co-activation was aimed at generation of porous solid valuable secondary products (activated carbons). The development of the design parameters for the activated carbons syntheses was done at valorization of the re-polymerization, re-association and the polycondensation reactions between the reference structural fragments of the components in the ternary composite systems "Spent Petroleum Product Waste – Biomass – D-grade coal" and "Coal Processing Sludge – Biomass – D-grade coal". From elaborated comprehensive
investigations the main factors, which influence the carbonized chars formation and the properties of the resulted activated carbons were evaluated. The porous solid secondary products of uniform particle size and pore size distribution were obtained during co-processing in the co-mingled systems. The surface area is ranged between 600-1100 m2/g, the total pore volume is of 0.32-0.47 m3/g and the yield is of 21-27%. Additionally, an efficiency of the catalytic co-processing of natural organic solid and liquid wastes with coal in a presence of the K/Na carbonates was studied aiming at novel adsorbents usage for wastewater purification from heavy metals
Performance of a plastic scintillator developed using styrene monomer polymerization
This paper presents a newly developed plastic scintillator produced in
collaboration with Turkiye Energy, Nuclear and Mineral Research Agency
(TENMAK). The scintillator is manufactured using thermal polymerization of
commercially available styrene monomer. The absorption spectrum of the
scintillator exhibited two absorption bands at 225 nm and 340 nm, with an
absorption edge observed at 410 nm. The wavelength of the emitted light was
measured in the range of 400-800 nm, with a maximum intensity at 427 nm.
Monoenergetic electrons from the 137Cs source were used to evaluate the
characteristics of the new scintillator, particularly its light yield. As the
light readout the MAPD-3NM type silicon photomultiplier array (4 x 4) with an
active area of 15 x 15 mm2, assembled using single MAPDs with an active area of
3.7 x 3.7 mm2, was used. The light yield of the scintillator was determined to
be 6134 photons/MeV. In addition, the efficiency of the scintillator for gamma
rays with an energy of 662 keV was found to be approximately 1.8 %. A CmBe
neutron source was employed to evaluate its fast neutron detection performance.
However, neutron/gamma discrimination using pulse shape discrimination (charge
integration) method was not observed. The results demonstrate the potential of
a newly produced plastic scintillator for various applications, particularly in
radiation monitoring and detection systems.Comment: 7 pages, 7 figure
Nonlocal nonlinear coupling of kinetic sound waves
We study three-wave resonant interactions among kinetic-scale oblique sound
waves in the low-frequency range below the ion cyclotron frequency. The
nonlinear eigenmode equation is derived in the framework of a two-fluid plasma
model. Because of dispersive modifications at small wavelengths perpendicular
to the background magnetic field, these waves become a decay-type mode. We
found two decay channels, one into co-propagating product waves (forward
decay), and another into counter-propagating product waves (reverse decay).
All wavenumbers in the forward decay are similar and hence this decay is
local in wavenumber space. On the contrary, the reverse decay generates waves
with wavenumbers that are much larger than in the original pump waves and is
therefore intrinsically nonlocal. In general, the reverse decay is
significantly faster than the forward one, suggesting a nonlocal spectral
transport induced by oblique sound waves. Even with low-amplitude sound waves
the nonlinear interaction rate is larger than the collisionless dissipation
rate. Possible applications regarding acoustic waves observed in the solar
corona, solar wind, and topside ionosphere are briefly discussed
Badanie równowag ekstrakcji w reakcji zasadowej hydrolizy aktywowanych estrów aminokwasów
Correlation between observed kinetic effects of phase-transfer catalytic reaction of the alkaline hydrolysis of 4-nitrophenyl ester of N-benzyloxycarbonylglycine-4 in the two-phase system chloroform-borate buffer pH = 10 and a content of ionic forms of catalyst was investigated. The phosphonium salts QX (X = Cl¯, Br¯, I¯) shows high catalytic reactivity. Dependence of the reaction kinetics discussed in the framework of the extraction mechanism with a competitive extraction of a nucleophile ОН¯, nucleofuge 4-NO2C6H4O¯ and anion X¯ of the phase-transfer catalyst.Zbadano korelację pomiędzy obserwowanym efektem kinetycznym przejścia fazowego katalitycznej reakcji zasadowej hydrolizy estru 4-nitrofenylowego N-benzyloksycarbonylglycyny-4 w dwufazowym układzie chloroform-bufor boranowy, pH = 10, z zawartością jonowych form katalizatora. Sole fosfoniowe QX (X = Cl¯, Br¯, I¯) wykazują wysoką aktywność katalityczną. Zależności kinetyki reakcji przeanalizowano w ramach mechanizmu ekstrakcji z konkurencyjną ekstrakcją nukleofilu ОН¯, grupą odchodzącą 4-NO2C6H4O¯ i anionem X¯ katalizatora przejścia fazowego
Voltage generation in hydrated calcium structures
Tarasov G.,Kidalov V., Okhrimenko O., Lyubchyk A., Liubchenko О., Ponomarenko V., Bacherikov Yu. Voltage generation in hydrated calcium structures. Розвиток сучасної науки та освіти : реалії, проблеми якості, інновації : матеріали ІІІ Міжнародної наук.-практ. інтернет-конференції (Запоріжжя, 30 вересня 2022 р.). Запоріжжя : ТДАТУ, 2022. С. 24-27.EN: This paper will consider the possible mechanisms and features of electricity generation during the adsorption of moisture by a porous structure. To compact the material in the form of tablets with a diameter of d=20 mm, a height of h~2 mm, the powder of xonotlite Ca6H2O19Si6 was compressed under the influence of single-axis pressure 3 Kbar. A hybrid structure was made that combines the properties of a membrane (due to nanoscale porosity) and water (which is considered as an electrolyte). UA: У даній роботі розглянуті можливі механізми та особливості генерації електроенергії при адсорбції вологи пористою структурою. Для пресування матеріалу у вигляді таблеток діаметром d=20 мм, висотою h~2 мм порошок ксонотліту Ca6H2O19Si6 пресували під дією одноосьового тиску 3 Кбар. Створено гібридну структуру, яка поєднує в собі властивості мембрани (за рахунок нанорозмірної пористості) і води (яка розглядається як електроліт)
Investigation of parameters of new MAPD-3NM silicon photomultipliers
In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIGMAPD is used to measure the parameters of theMAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developedMAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security
Photocatalytic activity of ZnO nanopowders: The role of production techniques in the formation of structural defects
International audienc
The Rectifying Contact of Hydrated Different Size YSZ Nanoparticles for Advanced Electronics
The paper considers the new effects of the nanoscale state of matter, which open up prospects for the development of electronic devices using new physical principles. The contacts of chemically homogeneous nanoparticles of yttrium-stabilized zirconium oxide (ZrO2—x mol% Y2O3, x = 0, 3, 4, 8; YSZ) with different sizes of 7.5 nm and 9 nm; 7.5 nm and 11 nm; and 7.5 nm and 14 nm, respectively, was studied on direct current using nanostructured objects in the form of compacts obtained by high-hydrostatic pressure (HP-compacts of 300MPa). A unique size effect of the nonlinear (rectifying-type contact) dependence of the electrical properties (in the region U < 2.5 V, I ≤ 2.7 mA) of the contact of different-sized YSZ nanoparticles of the same chemical composition is revealed, which indicates the possibility of creating semiconductor structures of a new type (homogeneous electronics). The electronic structure of the near-surface regions of nanoparticles of studied oxide materials and the possibility of obtaining specifically rectifying properties of the contacts were studied theoretically. Models of surface states of the Tamm-type are constructed considering the Coulomb long-range action. The discovered energy variance and its dependence on the curvature of the surface of nanoparticles made it possible to study the conditions for the formation of a contact potential difference in cases of nanoparticles of the same radius (synergistic effect), different radii (doped and undoped variants), as well as to discover the possibility of describing a group of powder particles within the Anderson model. The determined effect makes it possible to solve the problem of diffusion instability of semiconductor heterojunctions and opens up prospects for creating electronic devices with a fundamentally new level of properties for use in various fields of the economy and breakthrough critical technologies