Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет
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- Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Catalytic activity and selectivity of Palladium and Nickel catalysts in hydrogenation reactions of nitro- and acetylene compounds(Uralʹskij federalʹnyj universitet imeni pervogo Prezidenta Rossii B.N. Elʹcina, 2022-07-26) ;I.M. Jeldybayeva ;Zhaksyntay K. Kairbekov; ;Yermoldina ElmiraS.M. SuimbayevaThis 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.Цитирования (OpenAlex) 2Цитирования (OpenCitations) 1 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Physicochemical and Antioxidant Properties of Humic Acids from Low-Sulfur Kazakhstan Shales(Pleiades Publishing, 2022-09-01) ;S.M. Suimbayeva ;Ж. К. Каирбеков; ; Индира Мухаметкеримовна ДжелдыбаеваThe structural, chemical, and physicochemical characteristics and antioxidant properties of humic acids isolated from shale in the Kenderlyk and Kiin fields are determined. Negative values of the acids’ oxidation are found: –3.62 and –4.06 for Kenderlyk and Kiin shale, respectively. Thus, the shale-based humic acids are reducing agents. IR spectroscopic data show clear absorption bands of hydroxyl, functional, and carbonyl groups. ESR spectroscopy indicates a high content of paramagnetic centers in the humic acids: 9.3 × 10 17 and 9.5 × 10 17 spin/g for Kenderlyk and Kiin shale, respectively. The paramagnetic centers in the molecular structure of the humic acids indicate that they are promising as antioxidants.Цитирования (OpenAlex) 1Цитирования (OpenCitations) 1 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Physicochemical and Antioxidant Properties of Humic Substances from Coals of the Oy-Karagay and Kiyakty Deposits in the Republic of Kazakhstan(Pleiades Publishing, 2022-12-01) ;Индира Мухаметкеримовна Джелдыбаева ;Ж. К. Каирбеков; ; S.M. SuimbayevaAbstract The results of studies on the physicochemical and antioxidant properties of humic acids (HAs) and hymatomelanic acids (HMAs) from brown coals of deposits in the Republic of Kazakhstan are presented. It was found that the molecular structure of HAs from coals of the Oy-Karagay and Kiyakty deposits has functional groups of carbonyl, hydroxyl, and aliphatic nature as structural elements. The test samples of coals and HAs were characterized by the occurrence of paramagnetic centers (PMCs) with the Lande spectroscopic splitting factor values above 2.00, which indicate the presence of free radicals caused by a strongly delocalized electron cloud in the molecules of coals and HAs. The results of the amperometric determination of the antioxidant properties of HMAs indicated that the HMAs exhibit antioxidant activity, which will allow them to be used as a biologically active additive in the production of pharmaceutical preparations.Цитирования (OpenAlex) 2Цитирования (OpenCitations) 1 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Humic Acid Modified Applied Palladium Catalysts for Nitro Compounds Reduction(2023-01-01) ;Индира Мухаметкеримовна Джелдыбаева ;Zhaksyntay K. Kairbekov ;Manshuk Z. Esenalieva ;Altay Zh. KairbekovS.M. SuimbayevaThis work studies the possibility of using humic acids (HA) as a natural polymer-modifier for applied palladium catalysts.New catalysts based on palladium -HA fixed on the carrier bauxite-094 (B-094) have been synthesized and their catalytic properties in the process of reducing p-nitrodiethylaniline (PNDA) and potassium o-nitrophinolate (PtONPh) have been studied.Humic acid is a non-toxic, inexpensive, easily accessible high molecular weight polymer.Therefore, its use as a modifier polymer for applied palladium catalysts in the processes of hydrogenation of nitro compounds is very cost-effective and relevant as of today.This work presents the results of studies on different methods for the preparation of polymer metal catalysts.It has been shown that HA has stronger acid and sorption properties, greater branching and asymmetry of macromolecules.It has been established that the activity and stability of polymer-metallic complexes (PMC) based catalysts depend on the sequence of application of the active phase on the carrier.The largest specific surface area is characterized by the catalyst 1.0% Pd-HA (1.0%)/B-094, which exhibits the greatest activity and stability in the reduction reactions of PNDA and PtONPh.Considering that HA (polymer) and bauxite-094 (carrier) are materials of natural origin, the development of such catalysts is not accompanied by large economic costs, which is one of the main requirements for modern catalysts.Цитирования (OpenAlex) 4Цитирования (OpenCitations) 3 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Antioxidant Activity and Bioavailability of Humic Substances of Low-Mineralized Sulphide Mud(2023-01-01) ;Ж. К. Каирбеков ;S.M. Suimbayeva ;Индира Мухаметкеримовна Джелдыбаева ;Manshuk Z. EsenalievaHumic substances (HS) are natural compounds, the formation of which occurs in natural environments as a result of chemical and biological decomposition.HS accounts for 60% to 80% of organic matter in soil and aquatic environment.Therefore, we obtained samples of HS isolated from low-mineralized sulphide mud deposits of Tuzkol Lake (Republic of Kazakhstan) were obtained.HS samples have been characterized by instrumental methods: EPR spectroscopy and amperometry.Analysis of the concentration of paramagnetic centers shows that the minimum number of free radicals contains molecules of fulvic acids, and the maximum number of free radicals contains molecules of humic acids (HA) of peloids.The antioxidant activity and bioavailability of humic preparations in the form of sodium humates depending on the concentration of HS have been investigated.The information obtained indicates that HS have antioxidant activity and bioavailability, the value of which increases when the concentration of the solution grows.Dialysis of silver humate has been carried out in the presence of dimethyl sulfoxide (DMSO) at concentrations of 0.1; 1.0; 5.0 and 10% w/w.For HA and silver humate, a 10% concentration of DMSO is optimal, which allows a maximum yield of peloid preparations and a 1.6-fold increase in permeability.Dialysis of silver humate is 1.2 times more intensive than dialysis of HA.It has been shown that the change in the total content of antioxidants in various fractions of humic substances increases in the series; fulvic -humic -gimatomelanic acids.Цитирования (OpenAlex) 1
