Elmira Yermoldina

Mrs. Elmira Yermoldina

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 May 2025 in Electrochem
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AAAzhar Abdrakhmanova
Azhar Abdrakhmanova
ASAlfira Sabitova
Alfira Sabitova
Binur MussabayevaBinur Mussabayeva
Binur Mussabayeva
BBBulbul Bayakhmetova
Bulbul Bayakhmetova
ZSZhanna Sharipkhan
Zhanna Sharipkhan
EYElmira Yermoldina
Elmira Yermoldina
Anode-free lithium-ion batteries offer a volumetric energy density approximately 60% higher than that of conventional lithium-ion cells. Despite this advantage, they often experience rapid capacity degradation and a limited cycle life. Optimizing electrolyte formulations—particularly through the use of specific additives, solvents, and lithium salts—is essential to improving these systems. This study explores electrolytes composed of fluorinated and carbonate-based solvents applied in anode-free lithium-ion cells featuring copper as the anode substrate and Li1.05Ni0.33Mn0.33Co0.33O2 as the cathode. In the present work, the ionic conductivity of electrolytes was studied by impedance spectroscopy, and the electrochemical parameters of anode-free lithium-ion cells were compared using these electrolyte solutions: lithium difluoro(oxalato)borat (LIDFOB) salts were used in a mixture of solvents such as fluoroethylene carbonate (FEC) and dimethoxyethane (DME) in a ratio of 3:7 and in a mixture of propylene carbonate (PC) and dimethoxyethane in a ratio of 3:7. Enhanced performance was observed upon the substitution of conventional carbonates with fluorinated co-solvents. The findings suggest that LiDFOB is a thermostable salt, and its high conductivity contributes to the formation and stabilization of the interface of solid electrolytes. The results indicate that at low temperature conditions, a double salt should be used for lithium current sources, for example, 0.4 M LiDFOB and 0.6 M LiBF4, as well as electrolyte additives such as fluoroethylene carbonate and lithium nitrate.

26 July 2022 in Chimica Techno Acta
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IDIndira Indiko Dzheldybaeva
Indira Indiko Dzheldybaeva
ZKZhaksyntay K. Kairbekov
Zhaksyntay K. Kairbekov
KKKazhmukan O. Kishibayev
Kazhmukan O. Kishibayev
EYElmira Yermoldina
Elmira Yermoldina
SSSaltanat M. Suimbayeva
Saltanat M. Suimbayeva
This paper presents the results of a study on the catalytic activity and selectivity of nickel and palladium catalysts in hydrogenation reactions of nitro- and acetylene compounds. It was shown that the activity and selectivity of nickel catalysts in the hydrogenation of phenylacetylene depend on the nature of modifying additives (Cu, Zn, Ti, Cr, Bi, Ti–Cu, Mn, Fe), and the activity and selectivity of palladium catalysts based on a polymer of metal complexes depends on the method of their preparation. It was found that for certain concentrations of the active phase of palladium (0.8 wt.%) and the polymer of potassium humate (1.0 wt.%.) in the catalyst, where palladium and the polymer were deposited on bauxite-094 together, the catalyst exhibits the greatest activity and selectivity when hydrogenating phenylacetylene and potassium orthonitrophenolate.

15 October 2018 in THE BULLETIN
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ZKZhaksyntay Kairbekovich Kairbekov
Zhaksyntay Kairbekovich Kairbekov
IDIndira Indiko Dzheldybaeva
Indira Indiko Dzheldybaeva
EYElmira Yermoldina
Elmira Yermoldina
AMAnatoly Malоletnev
Anatoly Malоletnev

12 April 2021 in SERIES CHEMISTRY AND TECHNOLOGY
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ZKZh. K. Kairbekov
Zh. K. Kairbekov
SSS. M. Suimbayeva
S. M. Suimbayeva
IJI. M. Jeldybayeva
I. M. Jeldybayeva
EYElmira Yermoldina
Elmira Yermoldina
In this work, the effect of the amount of catalyst, modifying additives, and the phase composition of the alloys on the catalytic and isomerizing activity of skeletal in the hydrogenation reaction of hexane-1 is investigated. It has been shown that for all studied catalysts, the yield of products in the processes of migration and isomerization depends very strongly on the weighed portion of the catalyst introduced into the reaction medium. So, for example, the yield of hexane-2 with an increase in the catalyst weight increases linearly to 0.5g of nickel, while at the initial stage of the reaction the yield of hexane-2 reaches 62%. With a further increase in the catalyst weight (up to 1 g of Ni), the yield of hexane-2 decreases. The results of chromatographic analysis indicate a high activity of modified skeletal nickel catalysts in the reaction of migration of -C = C- bonds during hydrogenation of hexene-1. Modification of Fe, Pd, Sn and Ag increases the migration coefficient (Kmigr) from 0.66 to 0.70-0.77, while additions of Ti, Mo, Ti-Mo and Zr practically do not change it. The activity of the catalyst increases with the introduction of the metals Cu, Zn, Pb, Ti-Mo, Mo, Bi, Ag, and Mo-Cu (W=120-290 cm3/min·g Ni) into the initial alloy, while the addition of Fe, Pd and Mn (W=56-80 cm3/min·g Ni), while the influence of the components Ti, Zr and Sn is insignificant (W=115-117 cm3/min·g Ni).

14 March 2021 in Chemical Journal of Kazakhstan
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IJI.M. Jeldybayeva
I.M. Jeldybayeva
NUNon-commercial joint-stock company “Al-Farabi Kazakh National university”
Non-commercial joint-stock company “Al-Farabi Kazakh National university”
ZKZh.K. Kairbekov
Zh.K. Kairbekov
SSS.M. Suimbayeva
S.M. Suimbayeva
EYElmira Yermoldina
Elmira Yermoldina
ASAEO "Nasarbaev intellectual school"
AEO "Nasarbaev intellectual school"
This paper presents the results of a study on the hydrogenation of cyclopentadiene on modified skeletal nickel catalysts. It is shown that the activity of multicomponent skeletal nickel catalysts in the hydrogenation of cyclopentadiene is largely due to the nature of the additives introduced into the initial alloy. The introduction of Cu, Pb, Ta, Zn, Mo-Cu, Bi and Mo into the alloy leads to an increase in the activity (W = 14-280 cm3/min g Ni) and selectivity (Ks = 0.93-0.99) of cyclopentadiene hydrogenation, additions of Cr, Ti, Sn and Cr-Cu have no significant effect. As a result, when cyclopentadiene is hydrogenated, an intermediate alkene, cyclopentene, is formed. This is due to the cyclic structure of cyclopentadiene, which causes the formation of identical cycloalkene molecules when hydrogen is added to any position. The saturation of cyclopentadiene is completely completed upon absorption of 1 mole of hydrogen, and cyclopentene can be obtained in high yield.

1 January 2025 in 3i: intellect, idea, innovation - интеллект, идея, инновация
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ATAlmaty University of Power Engineering and Telecommunications
Almaty University of Power Engineering and Telecommunications
AOAray Orazaliyeva
Aray Orazaliyeva
EYElmira Yermoldina
Elmira Yermoldina
ARAlmaty Branch Of Infracos Rse
Almaty Branch Of Infracos Rse
YSYelena Stepanova
Yelena Stepanova
АСАйсұлу Сайлығара
Айсұлу Сайлығара
Reserving and restoring soil fertility is one of the key tasks of agricultural science, especially under increasing anthropogenic pressure. In areas exposed to hydrocarbon pollution, including rocket fuel, disturbances occur in microbiological processes that determine the stability of agroecosystems. Assessment of soil biological and enzymatic activity makes it possible to determine the degree of its degradation and the prospects for agricultural use. The aim of this study was to investigate the effect of T-1 and RG-1 kerosene on the microbial community and enzymatic activity of brown soils collected in the area of the Soyuz rocket stage fall. The objectives included determining catalase, protease, cellulase, and dehydrogenase activity of microorganisms in dynamics (1st and 90th days of the experiment), as well as establishing the dose-dependent effect of hydrocarbon pollution. The methodology was based on classical microbiological and biochemical approaches, including in vitro tests for enzymatic activity and spectrophotometric determination of dehydrogenases. The results showed that at fuel concentrations above 500 mg/kg there was a marked decrease in soil microorganisms and biological activity, indicating a critical level of toxicity for agroecosystems. By the 90th day, the suppression of enzymatic activity persisted, although part of the microbial community demonstrated resistance to contamination. The practical significance of the study lies in the use of identified indicators for environmental standardization, monitoring of agricultural soils, and predicting the consequences of pollution for productivity. The contribution of the work is the clarification of threshold concentrations of hydrocarbons affecting soil biota, which is essential for agroecology and sustainable land use.