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Machine learning models for accurately predicting properties of CsPbCl3 Perovskite quantum dots
Full text linkPerovskite Quantum Dots (PQDs) have a promising future for several applications due to their unique properties. This study investigates the effectiveness of Machine Learning (ML) in predicting the size, absorbance (1S abs) and photoluminescence (PL) properties of CsPbCl3 PQDs using synthesizing features as the input dataset. The study employed ML models of Support Vector Regression (SVR), Nearest Neighbour Distance (NND), Random Forest (RF), Gradient Boosting Machine (GBM), Decision Tree (DT) and Deep Learning (DL). Although all models performed highly accurate results, SVR and NND demonstrated the best accurate property prediction by achieving excellent performance on the test and training datasets, with high R2, low Root Mean Squared Error (RMSE) and low Mean Absolute Error (MAE) metric values. Given that ML is becoming more superior, its ability to understand the QDs field could prove invaluable to shape the future of nanomaterials designing. © 2025 Elsevier B.V., All rights reserved
Generalization of some integral inequalities via interval-valued functions
Full text linkBu tez çalışmasında, aralık değerli LR-konveks fonksiyonlar ele alınmış ve bu fonksiyonlar için uyumlu kesirli integral operatörlerine dayalı, yeni eşitsizlikler elde edilmiştir. Tez dört bölümden oluşmaktadır. İlk bölümde eşitsizliklerin, konveks küme ve fonksiyonların, kesirli integral tanımlarının, aralık analizinin ve aralık değerli LR-konveks fonksiyonların tarihsel gelişim süreci anlatılmıştır. İkinci bölümde, tezde kullanılacak temel tanım ve teoremlere yer verilmiş, hem reel değerli hem de aralık değerli fonksiyonlar için gerekli ön bilgiler sunulmuştur. Üçüncü bölümde, aralık değerli LR-konveks fonksiyonlara ilişkin olarak uyumlu kesirli integral operatörleri yardımıyla yeni eşitsizlikler elde edilmiş ve uygun seçimler yapıldığında yeni sonuçlara ulaşılmıştır. Ayrıca parametrelerin özel seçimleri ile literatürdeki bazı çalışmaların genelleştirildiği görülmektedir. Dördüncü ve son bölümde ise tez boyunca ulaşılan sonuçlar özetlenmiş ve ileride yapılabilecek çalışmalara yönelik bazı öneriler sunulmuştur.In this thesis, LR-convex interval-valued functions are examined, and new inequalities based on conformable fractional integral operators are obtained for these functions. The thesis consists of four chapters. In the first chapter, the historical developments of inequalities, convex sets and functions, definitions of fractional integrals, interval analysis, and LR-convex interval-valued functions are discussed. The second chapter presents the fundamental definitions and theorems to be used throughout the thesis, providing essential background information for both real-valued and interval-valued functions. In the third chapter, new inequalities are obtained for LR-convex interval-valued functions using conformable fractional integral operators, and new results are reached through appropriate selections. Additionally, it is observed that some studies in the literature have been generalized through special choices of parameters. Finally, the fourth chapter summarizes the results are obtained throughout the thesis and offers suggestions for future research
Sağlık Hizmeti Talebinde İnfluencer Etkisinin Belirlenmesine Yönelik Bir Ölçek Geliştirme Çalışması
Full text linkBu çalışmanın amacı, influencerların sağlık hizmet talebi üzerindeki etkisini belirleyen psikometrik bir ölçüm aracının geliştirilmesidir. Bu doğrultuda, İstanbul ilinin Silivri ilçesinde ikamet eden 379 birey çalışma kapsamına dahil edilmiştir. Çalışma kapsamında ölçek geliştirme süreci uygulanmıştır. Bu bağlamda ilk olarak konu ile ilgili literatür taraması yapılıp 30 maddeden oluşan taslak ölçek oluşturulmuştur. Uzman görüşü ve pilot çalışma aşamalarının ardından 3 madde ölçekten çıkarılmıştır. Kalan 27 madde örneklem grubuna uygulanıp veri toplanmıştır. Katılımcılardan veriler yüz yüze ve çevrimiçi yöntemle toplanmış olup, katılımcılara kolayda örneklem yöntemi ile ulaşılmıştır. Toplanan verilerin analizi aşamasında ilk olarak açıklayıcı faktör analizi uygulanmıştır. Yapılan analiz sonucunda 4 faktör, 27 ifadeden oluşan bir yapı tespit edilmiştir. Açıklayıcı faktör analizi ile belirlenen yapının doğruluğunu tespit etmek amacıyla verilere doğrulayıcı faktör analizi uygulanmıştır. Yapılan analiz sonucunda, elde edilen modelin verilere mükemmel uyum sağladığı istatistiki olarak belirlenmiştir. Bu çalışma kapsamında geliştirilen ölçeğin sağlık hizmeti talebinde influencerların etkisinin belirlenmesi için kullanılabileceğine karar verilmiştir
A Fractional Version of Corrected Dual-Simpson's Type Inequality via s-convex Function with Applications
Full text linkConvexity plays a crucial role in mathematical analysis, offering profound insights into the behavior of functions and geometric shapes. Fractional integral operators generalize the classical concept of integration to non-integer orders. In this paper, we establish a new identity by using the Caputo-Fabrizio fractional integral operator. Then by using this new identity, we obtain the corrected dual Simpson's type inequalities for s-convex functions. By employing the wellknown integral inequalities such as the H & ouml;lder's inequality and power-mean inequality, we obtain new error estimates. Furthermore, we discuss the applications to some special means and quadrature formula
Synthesis of new heteroaromatic thiosemicarbazone compounds
Full text linkHeteroaromatik bileşikler, yapılarında karbon atomlarının yanı sıra azot, kükürt ve oksijen gibi heteroatomlar içeren halkalı organik bileşiklerdir. Tiyosemikarbazonlar, tiyosemikarbazit bileşikleri ile aldehit veya ketonların kondenzasyonundan elde edilen Schiff bazları sınıfındandır. Konjuge azot, kükürt iskelet sistemleri ve imin grupları içermeleri sebebiyle heterohalkalı tiyosemikarbazon bileşikleri özellikle biyolojik ve farmakolojik öneme sahip bileşiklerdir. Bu tez çalışması kapsamında, potansiyel antimikrobiyal ajanlar olarak 6 (altı) yeni heteroaromatik tiyosemikarbazon bileşiği sentezlenmiştir. Yeni heteroaromatik tiyosemikarbazon bileşikleri, template metot ile 4-amino-6-kloropirimidin-5-karboksaldehit ile tiyosemikarbazit ve benzaldehit türevlerinin (4-feniltiyosemikarbazit, tiyosemikarbazit, 4-etil-3-tiyosemikarbazit 2-imidazolkarboksaldehit, 2-piridinkarboksaldehit) kondenzasyon reaksiyonu sonucu elde edilmişlerdir. Bazı sptektroskopik teknikler (element analizi, FT-IR, 1H-NMR, 13C-NMR, SEM-EDS) kullanılarak sentezlenen yeni heteroaromatik tiyosemikarbazonların yapıları aydınlatılmıştır.Heteroaromatic compounds are cyclic organic compounds that contain heteroatoms such as nitrogen, sulfur, and oxygen in addition to carbon atoms in their structures. Thiosemicarbazones belong to the class of Schiff bases obtained by the condensation of thiosemicarbazides with aldehydes or ketones. Due to the presence of conjugated nitrogen, sulfur skeleton systems, and imine groups, heterocyclic thiosemicarbazone compounds are particularly significant in terms of their biological and pharmacological properties. In this thesis, six new heteroaromatic thiosemicarbazone compounds have been synthesized as potential antimicrobial agents. The new heteroaromatic thiosemicarbazones were obtained by the condensation reaction of 4-amino-6-chloropyrimidine-5-carbaldehyde with thiosemicarbazide and benzaldehyde derivatives (4-phenylthiosemicarbazide, thiosemicarbazide, 4-ethyl-3-thiosemicarbazide, 2-imidazolecarbaldehyde, 2-pyridinecarbaldehyde) using the template method. The structures of the synthesized new heteroaromatic thiosemicarbazones were elucidated using several spectroscopic techniques (elemental analysis, FT-IR, 1H-NMR, 13C-NMR, SEM-EDS)
Monitoring the rehabilitation process of the windthrow area using UAS images and performance comparison of Sentinel-2A based different vegetation indexes
Full text linkWindthrows significantly disrupt forest ecosystems, impacting biotic community life cycles. To ensure the reformation of the ecosystem chain, it is essential to rehabilitate the windthrow area as soon as possible. Therefore, it is mandotory to determine the success of the rehabilitation processes. In this study, the rehabilitation process of windthrow that occurred in the D & uuml;zce Tatl & imath;dere Forest District (DTFD) was identified using vegetation indices calculated from Unmanned Aircraft System (UAS) images and Sentinel-2A satellite images between 2017 and 2022. The Normalized Difference Red Edge Index (NDRE), Plant Senescence Reflectance Index (PSRI), and Normalized Difference Vegetation Index (NDVI) were calculated from Sentinel-2A satellite images, and the most successful index for detecting reforested areas was identified. UAS images were used to create training data, and this data was used to classify Sentinel-2A images with the Random Forest (RF) algorithm. The classification's accuracy was assessed using the Kappa Coefficient and Overall Accuracy (%). Results showed that NDVI had the lowest accuracy in both years, whereas NDRE succesfully detected windthrow area borders. PSRI was most successful in monitoring rehabilitation progress and detecting reforested areas between 2017 and 2022. This study, he effectiveness and limitations of the NDRE, PSRI and NDVI indices in the rehabilitation process of the windthrow area have been detected, and the most important Sentinel-2A bands were determined based on the results of the RF classification. This study is pioneering in the use of NDRE and PSRI to detect reforested areas post-windthrow.Duzce University [1919B012214608]TUBITAK 2209-A- University Students Research Projects Support ProgramThis study has been supported by TUBITAK 2209-A- University Students Research Projects Support Program with Project Number 1919B012214608
Investigation of changes in leaf area ındex in different forest stands
Full text linkLeaf area & imath;ndex (LAI) is a fundamental metric of forest canopy structure, driving photosynthetic capacity, carbon sequestration, and ecosystem productivity. In this study, we quantified LAI variation across six forest stand types (pure fir, pure beech, pure Scots pine, mixed coniferous, mixed deciduous, and mixed deciduous-coniferous) and six developmental stages in the D & uuml;zce region of Turkey, an area characterized by mixed, heterogeneous woodlands. Field measurements from 260 systematically distributed sample plots collected in 2015 employed hemispherical photography for LAI, the N-tree method for basal area (BA) and diameter at breast height (DBH), and atmospherically corrected Landsat 8 OLI imagery for NDVI. Descriptive analyses revealed LAI values ranging from 0.36 m(2)/m(2) in pure Scots pine to 6.30 m(2)/m(2) in mixed deciduous stands. One-way ANOVA and Duncan's multiple-range tests confirmed significant differences among stand types (p < 0.01), with mixed and vertically stratified stands exhibiting the highest LAI. Developmental stages showed increasing mean LAI trends from juvenile (ab) to mature (d) classes, though stage-only ANOVA was not significant (p = 0.378) due to high within-stage variability (CV approximate to 31%). Pearson correlations indicated moderate positive relationships between LAI and both DBH (r = 0.49) and BA (r = 0.53), whereas NDVI displayed the strongest association (r = 0.75 overall; up to r = 0.80 in mixed stands). A multiple linear regression model integrating NDVI, DBH, and BA explained 60.6% of LAI variance (F = 129.7, p < 0.001; adjusted R-2 = 0.601), with NDVI emerging as the dominant predictor (standardized beta = 0.683), followed by DBH (beta = 0.326) and BA (beta = 0.187). These findings underscore the complementary value of integrating spectral indices and structural parameters in the estimation of LAI, particularly in heterogeneous forest stands. The structural complexity of mixed stands appears to play a critical role in enhancing canopy development. To improve estimation accuracy in conifer-dominated or high-LAI forests, future studies should consider incorporating alternative vegetation indices and LiDAR-derived structural metrics to overcome limitations such as spectral saturation and insufficient vertical resolution. Such integrated approaches can significantly enhance the scalability and cost-effectiveness of forest health and productivity monitoring efforts.Scientific and Technological Research Council of Turkiye (TUBITAK) [TOVAG-213O199]This work was supported by the Scientific and Technological Research Council of Turkiye (TUBITAK, Project ID: TOVAG-213O199). The authors would also like to thank the Directors of Duzce Forest Enterprise for their collaboration on the field studies
A Rare Condition in the Differential Diagnosis of Arthritis, Preiser's Disease: A Case Report and Review of the Literature
Full text linkChronic wrist pain is a common clinical condition that negatively affects daily activities. Many diseases are involved in the etiology of chronic wrist pain. Identification of specific causes of pain increases treatment success and prevents disability. Detailed evaluation and necessary imaging methods for differential diagnosis of multiple clinical entities with similar history and examination findings are essential for accurate diagnosis and treatment success. Avascular necrosis is a progressive disorder resulting in partial or complete death of bone tissue cells due to impaired blood circulation of the bone, usually caused by nontraumatic or idiopathic etiology. Preiser's disease, avascular necrosis of the carpal scaphoid, is a rare disorder generally occurring on the dominant side and in women. This case report presents an uncommon disease that should be considered in the differential diagnosis while searching for the etiologic cause of chronic wrist pain
COVID-19 Sonrası Bağlamında Bell Felci İnsidansının Mevsimsel Görülme Şekli
Full text linkAim: This study aimed to investigate the seasonal effects on the incidence of Bell's palsy (BP), and to determine whether the rates fluctuate with changing seasons, particularly following the coronavirus disease 2019 (COVID-19) pandemic. Material and Methods: A retrospective analysis was conducted on 267 confirmed BP cases between January 2020 and December 2023. Data were collected on the onset dates, demographic information, and seasonal distribution of the cases. Cases were categorized based on their seasonal occurrence to identify trends and variations. Results: The study group included 137 males and 130 females, representing 51.3% and 48.7% of the sample, respectively. The mean age was 45.71±16.11 for males, and 47.51±19.27 years for females, with no significant difference (p=0.408). The overall mean age was 46.58±17.71 years. Although there was no statistically significant difference between seasons (p=0.322), a notable increase in BP incidence was observed in spring (28.8%) and summer (26.6%). The highest number of cases was observed in June and March. No significant difference was found in seasonal variations of BP incidence in terms of age (p=0.691) and gender (p=0.905). Conclusion: Contrary to conventional beliefs associated with BP in colder climates, findings of this study indicate a higher incidence of BP during warmer seasons, particularly in spring and summer. This trend might have been influenced by the aftermath of the COVID-19 pandemic. These results underscore the need for comprehensive studies to explore the interplay between environmental factors, viral pandemics such as COVID-19, and BP pathogenesis, potentially leading to better prevention and management strategies. © 2025 Elsevier B.V., All rights reserved
Synthesis and characterization of polymeric linoleic acid graft copolymers using atom transfer radical polymerization
Full text linkLinoleic acid modified through autoxidation, hydroxylation, and bromination was utilized for the first time in controlled/living radical polymerization methods such as atom transfer radical polymerization (ATRP). A brominated polymeric linoleic acid macromonomer initiator (ATRP-MIM) was synthesized as a macromolecular initiator (MIM) based on polymeric linoleic acid for use in ATRP. Using this ATRP-MIM and styrene monomer, novel graft copolymers were successfully synthesized via ATRP. The effects of various reaction parameters, including monomer concentration, initiator concentration, and polymerization kinetics, were systematically investigated. Additionally, the impact of reaction conditions on molecular weight and polydispersity was studied. The percentage compositions of the structural contents of graft copolymers were determined using 1H NMR. Detailed characterization, including structural analysis, thermal properties, and molecular weight determination, was performed using techniques such as Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The obtained graft copolymers exhibited enhanced thermal stability and well-defined molecular structures, contributing to the development of bio-based polymeric materials with specialized properties for applications in coatings, biocompatible systems, and advanced functional materials.Graphical abstractThis study introduces the use of modified linoleic acid, altered through autoxidation, hydroxylation, and bromination, in controlled radical polymerization methods such as atom transfer radical polymerization (ATRP) for the first time. The research focuses on the synthesis of graft copolymers by using a brominated polymeric linoleic acid initiator (ATRP-MIM) in copolymerization with styrene.Duezce Universitesi [2015.05.03.381, 2024.05.03.1541]This work was supported financially by the Duzce University Research Funds (Grant Numbers: 2015.05.03.381 and 2024.05.03.1541)