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

On the Possibility of Designing an Advanced Sensor with Particle Sizing Using Dynamic Light Scattering Time Series Spectral Entropy and Artificial Neural Network

LBUS‐IRG‐2019‐05 LBUS‐IRG‐2020‐06Dynamic Light Scattering is a well-established technique used in particle sizing. An alternative procedure for Dynamic Light Scattering time series processing based on spectral entropy computation and Artificial Neural Networks is described. An error analysis of the proposed method was carried out and the results on both the simulated and on the experimental DLS time series are presented in detail. The results reveal the possibility of designing an advanced sensor capable of detecting particles with a size bigger than a threshold using this alternative for processing the DLS time series.publishersversionpublishe

Reversible Martensitic Phase Transition in Yttrium-Stabilized ZrO2 Nanopowders by Adsorption of Water

Funding: This work was supported by H2020/MSCA/RISE/SSHARE number 871284 project and the RO-JINR Grant No. 367/2021 item 27 and RO-JINR Projects № 366/2021 items 57, 61, 83, 85. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The present study was aimed at revealing the influence of the mechanical stress induced by water molecule adsorption on the composition of crystalline phases in the ZrO2 + 3 mol% Y2O3-nanoparticles. Three basic methods were used to determine the phase transition: Neutron diffraction, Raman microspectroscopic scanning, and X-ray diffraction. The fact of reversible phase-structural β → α transformation and the simultaneous presence of two polymorphic structural modifications (β is the phase of the tetragonal syngony and α of monoclinic syngony in nanosized particles (9 nm)) under normal physical conditions was established by these methods. An assumption was made regarding the connection of the physical mechanism of transformation of the extremely nonequilibrium surface of nanoparticles with electronic exchange of the material of the near-surface layer of nanoparticles with the adsorption layer through donor-acceptor interaction. The principal possibility of creating direct-acting hydroelectric converters based on nanoscale YSZ (Yttria-Stabilized Zirconia) systems due to the reversible character of the considered effect was shown.publishersversionpublishe

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

Порівняльний аналіз модифікованих алгоритмів навчання з частковим залученням учителя на малій кількості розмічених даних

The paper is devoted to improving semi-supervised clustering methods and comparing their accuracy and robustness. The proposed approach is based on expanding a clustering algorithm for using an available set of labels by replacing the distance function. Using the distance function considers not only spatial data but also available labels. Moreover, the proposed distance function could be adopted for working with ordinal variables as labels. An extended approach is also considered, based on a combination of unsupervised k-medoids methods, modified for using only labeled data during the medoids calculation step, supervised method of k nearest neighbor, and unsupervised k-means. The learning algorithm uses information about the nearest points and classes’ centers of mass. The results demonstrate that even a small amount of labeled data allows us to use semi-supervised learning, and proposed modifications improve accuracy and algorithm performance, which was found during experiments.Присвячено вдосконаленню методів кластеризації з частковим під- кріпленням, а також порівнянню їх точності та стійкості. Запропонований під- хід заснований на розширенні алгоритмів кластеризації шляхом використання доступного набору міток класів за допомогою заміни функції відстані, при цьому за використання запропонованої функції відстані враховуються не тіль- ки просторові дані, але й мітки. Більше того, запропонована функція відстані може бути адаптована для роботи з порядковими змінними як мітки. Також запропоновано підхід, заснований на методі навчання без вчителя k-медоїдів, модифікований для використання лише розмічених даних на етапі обчислення медоїдів кластерів, комбінацію методу навчання з учителем k найближчих су- сідів та без вчителя – k-середніх. При цьому алгоритм навчання використовує інформацію як про найближчі точки, так і про центри мас класів. Отримані ре- зультати демонструють, що навіть невеликий обсяг помічених даних дає змогу використовувати навчання з частковим підкріпленням, а запропоновані моди- фікації забезпечують підвищення точності і стійкості алгоритму, що продемо- нстровано під час експериментів

Enhancement of the electrocaloric effect in the 0.4BCZT-0.6BTSn ceramic synthesized by sol-gel route

The lead-free ferroelectric 0.4Ba _0.85 Ca _0.15 Zr _0.10 Ti _0.90 O _3 –0.6BaTi _0.89 Sn _0.11 O _3 (0.4BCZT–0.6BTSn) ceramics were successfully prepared by the sol–gel process. Raman spectroscopy was used to examine the structural properties of the 0.4BCZT-0.6BTSn sample. The findings indicate that the sample was well crystallized into a single perovskite structure. The phase transitions of the studied sample have been investigated using the DSC technique. The electrocaloric effect (ECE) properties were indirectly determined using the Maxwell approach. Under a relatively low applied electric field of 30 kV cm ^−1 , the results show enhanced electrocaloric temperature change and entropy change of ΔT = 1.32 K and ΔS = 1.41 J/kg.K, respectively. Besides, the electrocaloric responsivity ( ξ _max = 0.45 K·mm/kV) obtained is among the highest reported values in pb-free ferroelectrics near room temperature. These findings demonstrate that the lead-free 0.4BCZT–0.6BTSn ceramic is a promising candidate for solid-state cooling applications

Effect of Si and Nb additions on carbonitride coatings under proton irradiation: A comprehensive analysis of structural, mechanical, corrosion, and neutron activation properties

In the present study, understoichiometric TiZrCN, TiZrNbCN, and TiZrSiCN coatings were produced using the cathodic arc technique with a C/N ratio of approximately 0.5 to investigate their potential use in nuclear technology. The coatings were evaluated for their corrosion resistance in 3.5 % NaCl and neutron activation. The effect of adding Si and Nb to the quaternary TiZrCN system was also investigated. The results showed that the addition of Si (∼4.64 at.%) to the matrix of TiZrCN improved their electrochemical properties in NaCl solution, the protective efficiency was 92%, while the Nb addition (∼5.5 at%) lead to the decrease in corrosion resistance by 1.39 times comparing with TiZrCN. Furthermore, after fast neutron irradiation at a nominal power of 1450 kW, none of the coatings were activated, indicating good radiation resistance. It was determined from the structural analysis that the Ti6Al4V substrate before corrosion consists of hexagonal and cubic space groups with different lattice parameters. By adding Si and Nb, a small amount of ZrO2 and Si3N4 was detected along with the main phases in the TiZrCN structure

Сomparison of fluorescence dyes for amyloid detection in prostate stones

Prostatic calculi are predominantly inorganic deposits that readily found in prostatic glands. They are stained in a different manner than corpora amylacea, which are predominantly organic a myloid deposits and also readily found in ageing prostate. When prostatic calculi reach millimetre dimensions they can be easily extracted and analysed for composition purposes. The results of such an analysis suggest that prostatic calculi contain organic inclusions from various peptides. It is also believed that peptides forming organic part play crucial role in the biogenesis of prostatic calculi (Sfanos K.S. et al, 2009). A lot of authors support the idea of calculi formation by the mineralization process of corpora amylacea

Сomparison of fluorescence dyes for amyloid detection in prostate stones

Prostatic calculi are predominantly inorganic deposits that readily found in prostatic glands. They are stained in a different manner than corpora amylacea, which are predominantly organic a myloid deposits and also readily found in ageing prostate. When prostatic calculi reach millimetre dimensions they can be easily extracted and analysed for composition purposes. The results of such an analysis suggest that prostatic calculi contain organic inclusions from various peptides. It is also believed that peptides forming organic part play crucial role in the biogenesis of prostatic calculi (Sfanos K.S. et al, 2009). A lot of authors support the idea of calculi formation by the mineralization process of corpora amylacea

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