Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет
Постоянный URI для этого сообществаhttps://cris.qyzpu.kz/handle/123456789/1
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- Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Production and optimization of activated carbon from plant waste with high specific surface area for moisture-saving applications in agriculture(2024-10-20) ;Yerlan Doszhanov; ;Karina Saurykova ;Zulkhair Aimukhametovich MansurovIn conditions of water shortage, sustainable agricultural development requires the use of water-saving technologies, including the use of water-retaining substrates based on activated carbon. In this work, the textural and adsorption characteristics of activated carbon obtained from plant waste were studied at different mass ratios of the sorbent and KOH (1:1, 1:2, 1:3 and 1:4). The aim of the study was to determine the optimal activation conditions for creating a material with a high specific surface area and a developed porous structure. The results showed that the largest pore volume (1.6 cm3/g) and a high degree of microporosity are achieved at a ratio of 1:3, which is confirmed by the analysis of pore distribution using the DFT and BJH methods. FTIR spectroscopy revealed the presence of functional groups (O–H, C=O and C–O) that contribute to water conservation. The differential pore volume distribution (dv(r), cm3/Å/g) also demonstrated that at a ratio of sorbent and KOH (1:3), the sample structure optimally combines micropores and mesopores, which increases the adsorption capacity of carbon.Цитирования (OpenAlex) 1 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Comparative Study of the Structural and Adsorptive Performance of Biomass-Derived Graphene Materials(Multidisciplinary Digital Publishing Institute, 2026-02-08) ;Makpal Seitzhanova; ;Yerlan Doszhanov; Svetlana AleshkovaThis study presents the development of an environmentally benign and economically viable methodology for the synthesis of graphene-containing carbon materials derived from renewable agricultural residues, specifically walnut shells, rice husks, and apricot stones. The proposed synthesis route involves sequential stages of controlled pre-carbonization, desilicification, chemical activation with potassium hydroxide (KOH), and subsequent mild exfoliation, resulting in the formation of few-layer graphene with a high degree of structural ordering. Pre-carbonization carried out at 523–573 K, followed by activation at 1123 K, yields graphene sheets exhibiting a specific surface area of 1300–1800 m2/g, a carbon content of 60–90%, and an average pore diameter below 100 nm. The synthesized materials were subjected to comprehensive physicochemical characterization using BET surface area analysis, Raman spectroscopy, FTIR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic absorption flame emission spectrophotometry. Raman spectroscopic analysis revealed an I_G/I_2D intensity ratio of approximately 1.5–2.0, indicating the presence of graphene structures consisting of approximately four to five layers. To enhance adsorption performance, the graphene-containing carbon materials were further functionalized with sulfuric acid, and the successful incorporation of surface functional groups was confirmed by FTIR spectroscopy. The adsorption properties of the functionalized graphene-containing carbon materials were evaluated in aqueous solutions containing sodium, potassium, calcium, and magnesium salts, demonstrating adsorption efficiencies of up to 80%. Compared to conventional biomass-derived graphene synthesis methods, the developed approach produces materials with enhanced porosity, higher graphitic ordering, and improved chemical purity. These characteristics highlight the strong potential of the synthesized graphene-containing carbon materials for applications in energy storage systems, adsorption-based water purification technologies, and environmentally sustainable nanotechnological applications.Цитирования (OpenAlex) 4 - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Impact of Zeolites on Growth Dynamics of Medicago sativa and Lactuca sativa in Hydroponics(Multidisciplinary Digital Publishing Institute, 2026-02-28) ;Yerlan Doszhanov ;Dana Akhmetzhanova ;Leticia Fernández Velasco ;Korlan KhamitovaArman ZhumazhanovIn Kazakhstan, food safety is a pressing issue due to water and soil pollution. This study examined the effect of natural zeolite as an alternative hydroponic substrate on the physicochemical properties of the medium and the physiological and metabolic responses of two agricultural crops: Medicago sativa L. and Lactuca sativa L. BET analysis revealed that the zeolite possesses a substancial specific surface area (22 m²/g), ensuring effective moisture retention and gradual nutrient release. After plant cultivation, these parameters decreased moderately, confirming the filling of the pores with organic compounds without loss of key properties. In experiments with Medicago sativa, zeolite provided better aeration and stable moisture, promoting the development of a branched root system and increased seedling viability compared to an artificial substrate. Metabolic analysis of three Lactuca sativa varieties revealed cultivar-specific adaptive responses. Zeolite increased the synthesis of fatty acids and their derivatives, reflecting membrane-protective restructuring, while sugar and terpenoid content varied depending on the variety. The results confirm the suitability of zeolite as a stable substrate for hydroponic production, allowing for optimized water consumption, improved root development, and enhanced physiological stability of plants.Цитирования (OpenAlex) 2
