http://repository.enu.kz/handle/enu/16982 2026-04-03T18:03:45Z 2026-04-03T18:03:45Z Suchikova, Yana Kovachov, Sergii Bohdanov, Ihor Konuhova, Marina Zhydachevskyy, Yaroslav Kumarbekov, Kuat Pankratov, Vladimir Popov, Anatoli I. http://repository.enu.kz/handle/enu/29850 2026-03-05T19:03:06Z 2024-01-01T00:00:00Z

Wet Chemical Synthesis of AlxGa1−xAs Nanostructures: Investigation of Properties and Growth Mechanisms Suchikova, Yana; Kovachov, Sergii; Bohdanov, Ihor; Konuhova, Marina; Zhydachevskyy, Yaroslav; Kumarbekov, Kuat; Pankratov, Vladimir; Popov, Anatoli I. This study focuses on the wet chemical synthesis of AlxGa1−xAs nanostructures, highlighting how different deposition conditions affect the film morphology and material properties. Electrochemical etching was used to texture GaAs substrates, enhancing mechanical adhesion and chemical bonding. Various deposition regimes, including voltage switching, gradual voltage increase, and pulsed voltage, were applied to explore their impact on the film growth mechanisms. SEM analysis revealed distinct morphologies, EDX confirmed variations in aluminum content, Raman spectroscopy detected structural disorders, and XRD analysis demonstrated peak position shifts. The findings emphasize the versatility and cost-effectiveness of wet electrochemical methods for fabricating high-quality AlxGa1−xAs films with tailored properties, showing potential for optoelectronic devices, high-efficiency solar cells, and other advanced semiconductor applications.

2024-01-01T00:00:00Z Callaghan, Peter J. Caffrey, David Zhussupbekov, Kuanysh Berman, Samuel Zhussupbekova, Ainur Smith, Christopher M. Shvets, Igor V. http://repository.enu.kz/handle/enu/29849 2026-03-05T19:02:20Z 2024-01-01T00:00:00Z

Variation in the Bandgap of Amorphous Zinc Tin Oxide: Investigating the Thickness Dependence via In Situ STS Callaghan, Peter J.; Caffrey, David; Zhussupbekov, Kuanysh; Berman, Samuel; Zhussupbekova, Ainur; Smith, Christopher M.; Shvets, Igor V. Amorphous transparent conducting oxides (aTCOs) have seen substantial interest in recent years due to the significant benefits that they can bring to transparent electronic devices. One such material of promise is amorphous ZnxSn1−xOy (a-ZTO). a-ZTO possesses many attractive properties for a TCO such as high transparency in the visible range, tunable charge carrier concentration, electron mobility, and only being composed of common and abundant elements. In this work, we employ a combination of UV−vis spectrophotometry, X-ray photoemission spectroscopy, and in situ scanning tunneling spectroscopy to investigate a 0.33 eV blue shift in the optical bandgap of a-ZTO, which we conclude to be due to quantum confinement effects.

2024-01-01T00:00:00Z Amangeldy, Nurzada Gazizova, Nazerke Milosz, Marek Kurmetbek, Bekbolat Nazyrova, Aizhan Kassymova, Akmaral http://repository.enu.kz/handle/enu/29848 2026-03-05T19:01:41Z 2025-01-01T00:00:00Z

Unsupervised Clustering and Ensemble Learning for Classifying Lip Articulation in Fingerspelling Amangeldy, Nurzada; Gazizova, Nazerke; Milosz, Marek; Kurmetbek, Bekbolat; Nazyrova, Aizhan; Kassymova, Akmaral This paper presents a new methodology for analyzing lip articulation during fingerspelling aimed at extracting robust visual patterns that can overcome the inherent ambiguity and variability of lip shape. The proposed approach is based on unsupervised clustering of lip movement trajectories to identify consistent articulatory patterns across different time profiles. The methodology is not limited to using a single model. Still, it includes the exploration of varying cluster configurations and an assessment of their robustness, as well as a detailed analysis of the correspondence between individual alphabet letters and specific clusters. In contrast to direct classification based on raw visual features, this approach pre-tests clustered representations using a model-based assessment of their discriminative potential. This structured approach enhances the interpretability and robustness of the extracted features, highlighting the importance of lip dynamics as an auxiliary modality in multimodal sign language recognition. The obtained results demonstrate that trajectory clustering can serve as a practical method for generating features, providing more accurate and context-sensitive gesture interpretation.

2025-01-01T00:00:00Z Lagunay, Rachel Anne E. Adalim, Ritche Roi B. Tleubekova, Aruzhan Suleimenova, Diana Fernandez, Marvin Jose F. O’Reilly, Robert J. Balanay, Mannix P. http://repository.enu.kz/handle/enu/29847 2026-03-05T19:04:48Z 2024-01-01T00:00:00Z

Trade-Off between Degradation Efficiency and Recyclability: Zeolite-Enhanced Ni3−xCoxS4 Catalyst for Photocatalytic Degradation of Methylene Blue Lagunay, Rachel Anne E.; Adalim, Ritche Roi B.; Tleubekova, Aruzhan; Suleimenova, Diana; Fernandez, Marvin Jose F.; O’Reilly, Robert J.; Balanay, Mannix P. We herein report successful syntheses of both nickel cobalt sulfide (NCS) and its composite with zeolite (NCS@Z) using a solvothermal method. Techniques such as EDX analysis, SEM, and molar ratio determination were used for product characterization. The incorporation of NCS significantly changed the surface roughness and active sites of the zeolite, improving the efficiency of methylene blue degradation and its reusability, especially under UV irradiation. In comparing the pseudo-first order rates, the highest degradation efficiency of methylene blue was achieved with NCS-2@Z, having a degradation extent of 91.07% under UV irradiation. This environmentally friendly approach offers a promising solution for the remediation of methylene blue contamination in various industries.

2024-01-01T00:00:00Z