Eurasian Chemico-Technological Journal
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Published By Institute Of Combustion Problems

2522-4867, 1562-3920

2021 ◽  
Vol 23 (3) ◽  
pp. 221
Author(s):  
P.R. Gard

The World Health Organisation estimates that alcohol abuse by adults accounts for about 5% of global disease burden. Additionally, prenatal alcohol exposure (PAE) causes ‘fetal alcohol spectrum disorder’ (FASD). Depending on severity, FASD is characterised by low birth weight, small head size at birth and growth retardation. There are also facial features of narrow eyes, flat upper lip and midface and impaired fine motor skills, hearing loss, poor hand-eye coordination and cognitive impairment. World-wide, up to 10% of children may be affected by PAE. It is unclear what dose or pattern of drinking results in these damaging effects, but animal models suggest that high, acute doses of ethanol (‘binge drinking’) in early pregnancy can result in the facial changes of FASD, whilst sustained, lower dose intake in later pregnancy produces anxiety and depression-like symptoms and deficits of learning and memory. The mechanisms underlying the deleterious effects of PAE are also unresolved, but evidence exists of long-lasting damage due to oxidative stress, increases in inflammatory mediators and changes to the brain renin-angiotensin system. There is also evidence of epigenetic changes. There is a need to prevent or limit the potential adverse effects of ethanol on the unborn child. It is highly unlikely, however, that all sexually-active women of child-bearing age not using reliable contraception will abstain from alcohol. There is therefore a need to research methods of reducing ethanol toxicity for the unborn child and / or develop therapeutic strategies to reverse the deleterious effects of ethanol on the unborn child.


2021 ◽  
Vol 23 (3) ◽  
pp. 147
Author(s):  
I.Z. Ismagilov ◽  
A.V. Vosmerikov ◽  
L.L. Korobitsyna ◽  
E.V. Matus ◽  
M.A. Kerzhentsev ◽  
...  

In this work, the introduction of modifying additives in the composition of catalysts is considered as an effective mode of improving functional characteristics of materials for two processes of methane conversion into valuable products – methane dehydroaromatization (DHA of CH4) into benzene and hydrogen and autothermal reforming of methane (ATR of CH4) into synthesis gas. The effect of type and content of promoters on the structural and electronic state of the active component as well as catalyst activity and stability against deactivation is discussed. For DHA of CH4 the operation mode of additives M = Ag, Ni, Fe in the composition of Mo-M/ZSM-5 catalysts was elucidated and correlated with the product yield and coke content. It was shown that when Ag serves as a promoter, the duration of the catalyst stable operation is enhanced due to a decrease in the rate of the coke formation. In the case of Ni and Fe additives, the Ni-Мо and Fe-Mo alloys are formed that retain the catalytic activity for a long time in spite of the carbon accumulation. For ATR of CH4, the influence of M = Pd, Pt, Re, Mo, Sn in the composition of Ni-M catalysts supported on La2O3 or Ce0.5Zr0.5O2/Al2O3 was elucidated. It was demonstrated that for Ni-M/La2O3 catalysts, Pd is a more efficient promoter that improves the reducibility of Ni cations and increases the content of active Nio centers. In the case of Ni-M/Ce0.5Zr0.5O2/Al2O3 samples, Re is considered the best promoter due to the formation of an alloy with anti-coking and anti-sintering properties. The use of catalysts with optimal promoter type and its content provides high efficiency of methane valorization processes.


2021 ◽  
Vol 23 (3) ◽  
pp. 191
Author(s):  
Y. Boutillara ◽  
L. Richelet ◽  
L.F. Velasco ◽  
P. Lodewyckx

The performance of porous carbon materials as sorbents is often compromised by the presence of humidity. Studying the kinetics of water vapour adsorption on activated carbons will undeniably help to overcome this issue. This has been approached in this work by evaluating the influence of several operational factors on the dynamic adsorption of water vapour in these materials. Specifically, different carbon types, particle sizes, air flows and ambient conditions (temperature and relative humidity (RH)) were systematically investigated. The impact of each isolated parameter on both the maximum water uptake and the uptake rate was analyzed by fitting the experimental data to the Linear Driving Force (LDF) kinetic model. The results show that except for the particle size, the studied variables play a role in the water sorption kinetics, although to a different extent. It was also confirmed that the LDF model can adequately describe the kinetics of water vapour adsorption independently of the experimental conditions. Finally, the complete water vapour adsorption process can be described by this model, obtaining a different value of the kinetic constant for the sequential stages, involving different adsorption mechanisms.


2021 ◽  
Vol 23 (3) ◽  
pp. 169
Author(s):  
C. Yu ◽  
U. Maas

In order to address the impact of the concentration gradients on the chemistry – turbulence interaction in turbulent flames, the REDIM reduced chemistry is constructed incorporating the scalar dissipation rate, which is a key quantity describing the turbulent mixing process. This is achieved by providing a variable gradient estimate in the REDIM evolution equation. In such case, the REDIM reduced chemistry is tabulated as a function of the reduced coordinates and the scalar dissipation rate as an additional progress variable. The constructed REDIM is based on a detailed transport model including the differential diffusion, and is validated for a piloted non-premixed turbulent jet flames (Sandia Flame D and E). The results show that the newly generated REDIM can reproduce the thermo-kinetic quantities very well, and the differential molecular diffusion effect can also be well captured.


2021 ◽  
Vol 23 (3) ◽  
pp. 133
Author(s):  
A.A. Markov ◽  
K.S. Martirosyan

Theoretical model for the simulation of synthesis of Janus-like particles (JP) consisting two different phases using the Carbon Combustion Synthesis of Oxides (CCSO) is presented. The model includes the variation of sample initial porosity, carbon concentration and oxygen flow rate used to predict the formation of JP features. The two temperature (2T) combustion model of chemically active submicron-dispersed mixture of two phases including ferroelectric and ferromagnetic was implemented and assessed by using the experimentally estimated activation energy of 112±3.3 kJ/mol and combustion temperature. The experimental values allowed to account the thermal and concentration expansion effect along with the dispersion by the slip-jump simulation for high Knudsen numbers. The model predicted that the smaller initial porosity of the combustion media creates higher formation rate of Janus-like particles. The simulation of slippage and jumps of the gas temperature allowed the scale-bridging between macro- and micro- structures.


2021 ◽  
Vol 23 (3) ◽  
pp. 213
Author(s):  
S. Barbarossa ◽  
M. Murgia ◽  
R. Orrù ◽  
G. Cao

The fabrication by Spark Plasma Sintering (SPS) of bulk high entropy ceramics from powders obtained by Self-propagating High temperature Synthesis (SHS) is addressed in this work. The effect produced by the introduction of 1 wt.% of graphite to the powders before SPS is investigated under different temperature conditions. The final density and composition of sintered (Hf0.2Mo0.2Zr0.2Ti0.2Ta0.2)B2 and (Hf0.2Mo0.2Zr0.2Ti0.2Nb0.2)B2 ceramics are found to be negatively affected by the presence of oxide impurities in the powders. While product composition can be progressively improved when the temperature is increased from 1800 to 1950 °C, residual porosities remain relatively high if using additive-free powders. In contrast, the introduction of 1 wt.%C markedly allows for oxides elimination by carbothermal reduction mechanism. Products consolidation is correspondingly enhanced so that relative densities of about 97% are attained. Other than the latter effect, surface oxides removal also makes powders more reactive, thus the synthesis of single-phase products is promoted. In particular, fully homogeneous (Hf0.2Mo0.2Zr0.2Ti0.2Ta0.2)B2 ceramics are obtained at relatively lower temperature conditions (1850 °C).


2021 ◽  
Vol 23 (3) ◽  
pp. 227
Author(s):  
P. Caputo ◽  
M. Porto ◽  
V. Loise ◽  
A. Abe ◽  
B. Teltayev ◽  
...  

The organic fraction derived from the differentiated collection of urban waste is mainly composed of fatty acids, medium molecular weight hydrocarbons and cellulose. This peculiar composition gave us insight into the possible use of organic waste to improve bitumen’s characteristics (possible antioxidant, regenerating and/ or viscosifying additive for road pavements). The issue of the disposal of organic waste is a global one and it’s constantly of increasing concern. This study looks to alleviate this problem by finding ways for this waste fraction to be utilized for the greater good- in this case, as an additive for bitumen binder in road pavements. The present study is focused on the use of waste as it is and waste treated by the FENTON process (treatment with ferrous sulphate and hydrogen peroxide solution). Dynamic Shear Rheology (DSR) and aging tests (Rolling Thin Film Oven Test, RTFOT) showed that two of the additives tested in this study proved effective: one can be utilised as a viscosifying agent and the other can be us ed as a filler.


2021 ◽  
Vol 23 (3) ◽  
pp. 199
Author(s):  
I. Kurmanbayeva ◽  
A. Mentbayeva ◽  
A. Nurpeissova ◽  
Z. Bakenov

With the rapid development of new and advanced technologies, the request for energy storage device with better electrochemical characteristics is increasing as well. Therefore, the search and development for more novel and efficient energy storage components are imperative. In Kazakhstan there are several groups that were established to conduct research in the field of energy storage devices. One of them is professor Mansurov’s research group with we have a long time fruitful collaboration. Group at Nazarbayev University do research in design and investigation of advanced energy storage materials for high performance energy storage devices, including lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, and aqueous rechargeable batteries, employing strategies as nanostructuring, nano/micro combination, hybridization, pore-structure control, configuration design, 3D printing, surface modification, and composition optimization. This manuscript reviews research on advanced battery materials, provided by Nazarbayev University scientists since the last 10 years.


2021 ◽  
Vol 23 (3) ◽  
pp. 181
Author(s):  
R. Zhao ◽  
F. He ◽  
F. Behrendt ◽  
J. Cai ◽  
A. Dieguez-Alonso ◽  
...  

In order to deepen the understanding of the thermochemical behavior of reactive inorganics, which play an important role in slagging and fouling during combustion of agro-stalks, the oxidation behavior of the water-soluble fraction of corn stover, wheat straw and rice straw was examined using a simultaneous thermogravimetric analyzer. The oxidation characteristics were discussed in combination with elemental analysis of water-soluble fractions. Results showed that reactive inorganics elements account for 30–40% in water-soluble fractions of the three agro-stalks and carbon was oxidized at two separate stages. Four stages were found during oxidation of water-soluble fractions – (1) devolatilisation of organics (100‒400 °C); (2) oxidation of char (400–650 °C); (3) oxidation of char with melting of salts or decomposition of carbonate (650–800 °C); (4) vaporization of KCl (800–1000 °C). This work provides a base study for an optimized design of combustion for agro-stalks and pharmaceutical waste.


2021 ◽  
Vol 23 (2) ◽  
pp. 77
Author(s):  
Tongfei Cheng ◽  
Jinxing Cao ◽  
Xiaohong Jiang ◽  
M.A. Yarmolenko ◽  
A.A. Rogachev ◽  
...  

In this paper, icaritin film was prepared by low-energy beam electron beam deposition (EBD). The material test showed that the structure and composition of icaritin were not changed after electron beam deposition. Then, the film was sliced and immersed in simulated body fluids, it can be seen that the film was released quickly in the first 7 days. With the extension of soaking time, the release rate gradually slowed down, and the release amount exceeded 90% in about 20 days. In vitro cytotoxicity test showed that the relative cell viability rate of the film was still 92.32±1.30% (p<0.05), indicating that the film possessed excellent cytocompatibility.


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