21241 research outputs found
Sort by
Multispectral analysis of photosensitive perovskite-E7 liquid crystal composites: Correlating optical response with electrical properties
Get PDFThis study investigates the photoresponsive electrical and dielectric characteristics of CH3NH3PbI3-xClx perovskite precursor ink-doped nematic liquid crystal (E7) composite under variable illumination intensities (0-100 mW/cm2). Through comprehensive electrochemical impedance spectroscopy analysis, we observed significant light-dependent modulation of charge transport mechanisms. Electrochemical impedance spectroscopy measurements revealed a 27-fold enhancement in current density under 100 mW/cm2 illumination compared to dark conditions. Complex impedance analysis demonstrated systematic reduction in charge transfer resistance with increasing light intensity, while dielectric studies revealed distinct relaxation processes in low and highfrequency regions. The composite exhibited dual relaxation times (tau 1, tau 2) that decreased from 430 to 90 s at first relaxation region (tau 1), and reaching maximum values from 8x10-4 s to 2.5 x 10-3 s at second relaxation region (tau 2) significantly with increasing illumination. AC conductivity analysis revealed four distinct conduction regions with varying frequency dependencies, suggesting multiple charge transport mechanisms. These findings demonstrate the potential of perovskite-liquid crystal composites for optoelectronic applications requiring tunable electrical and dielectric properties
The calibration of the MMC damage model under various hardening models and yielding criterions for DP800 steel
Get PDFThe use of Finite Element Analysis (FEA) in sheet metal forming processes has been increasing day by day. In recent studies, damage models that feature the effects of Lode angle parameter and stress triaxiality have been widely used in predicting fracture onset in sheet metals. However, the selection of the hardening model and yielding criterion can have significant impacts on the created fracture surface, and if not calibrated accurately, it can lead to erroneous fracture predictions. In this study, Modified Mohr-Coulomb (MMC) damage model has been calibrated for DP800 steel by using two different hardening models (Hollomon and Voce) and two different yielding criterions (Von-Mises and Hill-48). The effects of the hardening models and the yielding criterions on the predicted fracture surface of MMC have been investigated. Their prediction capability of the force-displacement curves for different deformation modes (uniaxial tension, plane strain and shear) have been compared. According to the results, it has been shown that both hardening models are accurate in their predictions up to 6% error, however, in addition to its accuracy in predicting force-displacement behaviours, the Voce hardening model has also been more successful in its fracture surface predictions
A Qualitative Study on the Use of Big Data in Marketing Insights in the Banking Sector
Get PDFThis study aims to determine how data obtained from different sources in the banking sector is used for marketing insights targeting customers. The research scope encompasses 38 banks listed on the Banking Regulation and Supervision Agency (BRSA) website, comprising 32 deposit banks and six participation banks. The data was collected through interviews with 20 participants from 13 banks. Descriptive and content analysis methods were used in the analysis process. The study's findings indicate that banks utilise big data for risk management, fraud detection, and customer relationship management. Additionally, banks effectively use all data obtained from internal and external processes to inform marketing insights, encompassing product, price, distribution, promotion, people, physical evidence, and process components
Turkish Women Authors in Emergency Medicine
Get PDFAim: A large number of articles are published in the field of Emergency medicine in Turkiye every year. This study aims to evaluate the number and quality of publications in the field of emergency medicine in Turkiye and to determine the effect of female authors on publication quality. Materials and Methods: A total of 32 international journals were identified. All articles published in these journals between January 01, 2015, and December 31, 2020 were reviewed, and publications by Turkish researchers were included in the study. Results: Most of the publications are case reports and series (35.7%), but the numbers of systematic reviews (0.4%) and meta-analyses (0.3%) are low. The median count of authors of the articles was 5 (1-32) [for women: 1 (0-16); for men: 4 (0-16); p0.05). Conclusion: The number of women authors was found to be statistically significant lower than the number of men authors. However, there was no gender difference in the distribution of first authors and corresponding authors. This showed that although the number of women was small, they were in an influential position
Exploring the Inflammatory Basis of Endometrial Polyps: Clinical Implications of Hematological Biomarkers in a Retrospective Study
Get PDFBackground/Objectives: Endometrial polyps (EPs) are common benign endometrial lesions often linked to abnormal uterine bleeding and infertility. While hormonal factors play a key role in their development, recent studies suggest a potential inflammatory component. This retrospective study aimed to assess systemic inflammatory markers, including mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), in EP patients. Methods: A total of 180 patients were classified into three groups: EP (n = 60), chronic endometritis (n = 60), and control (n = 60). Preoperative hematological parameters were retrieved from medical records. Group comparisons were performed using one-way ANOVA, with Tukey's post hoc test applied when significant. Multinomial logistic regression was used to identify independent predictors of EPs. Results: MPV and PLR were significantly higher in the EP group compared to other groups (p = 0.014 and p = 0.015, respectively), while NLR differences were not statistically significant (p = 0.086). Logistic regression identified MPV (p = 0.004) and PLR (p = 0.045) as independent predictors of EPs. Conclusions: These findings suggest that systemic inflammation may contribute to EP development, with MPV and PLR serving as potential inflammatory biomarkers. Further prospective studies with histopathological validation are needed to clarify the role of inflammation in EP pathogenesis
EFFECT OF GEOGRAPHY ON THE SPREAD OF EPIDEMIC DISEASES: PLAGUE OUTBREAK IN ANZOB IN SAMARCAND PROVINCE (1898)
Get PDFThroughout the 19th century, epidemics such as cholera, plague, and influenza emerged in Asia and, exhibiting pandemic characteristics, spread to Africa, Europe, and America. These outbreaks were facilitated by trade routes, wars, migrations, and expanding transportation networks, affecting vast geographical regions. The plague outbreak that began in China in 1893 rapidly spread through trade networks and human mobility, reaching other territories. By 1896, it had caused a major crisis in Bombay, a densely populated commercial hub. The plague, which caused the loss of thousands of lives in the city, was not confined to India and evolved into a global pandemic. By the late 19th century, the plague also made its presence felt in the region of Turkestan and became a significant threat. Epidemics in various regions resulted in high mortality rates, profoundly impacting societies and compelling administrative authorities to implement diverse public health policies. In response, quarantine measures, local health interventions, and medical treatments gained increasing importance in disease control efforts. Within this context, the bubonic plague outbreak that occurred in 1898 in Anzob, a village in the Samarkand Province, holds significance both in terms of the region’s geographical conditions and the interventions of the Russian administration. Anzob, an isolated and mountainous village, exhibited distinct patterns of disease transmission due to its settlement structure, limited transportation routes, and climatic conditions. The Russian government’s efforts to control the outbreak included strict quarantine measures, the isolation of infected areas, and the implementation of public health regulations, all of which played a crucial role in containing the disease. This study examines the bubonic plague outbreak in Anzob within the framework of the relationship between geography and the spread of infectious diseases, focusing on the measures taken to mitigate the epidemic. Furthermore, it explores the role of geographical factors in shaping the trajectory of the disease, the influence of environmental conditions on epidemic control, and the effectiveness of the Russian administration’s public health policies
Investigation of the effect of BİLSEM attendance level on LGS exam success and the factors determining BİLSEM attendance status
No full textBu çalışma, Düzce ilinde Bilim ve Sanat Merkezi (BİLSEM) öğrencilerinin devam durumlarını etkileyen faktörleri ve bu durumun Liseye Geçiş Sınavı (LGS) başarısı üzerindeki etkisini incelemeyi amaçlamaktadır. Araştırma, karma yöntem deseninde gerçekleştirilmiş ve hem nicel hem de nitel veriler kullanılmıştır. Nicel veri olarak LGS puanları, devamsızlık oranları ve demografik bilgiler toplanmıştır. Nitel veriler ise yarı yapılandırılmış görüşme formu yardımıyla toplanmıştır. Nicel verilerin analizinde ilişkiler incelenmiş, nitel verilerin analizinde ise tematik analiz yöntemine başvurulmuştur. Araştırma sonuçları, öğrencilerin devamsızlık oranları ile LGS puanları arasında anlamlı ve negatif bir ilişki olduğunu göstermiştir. Ayrıca, devamsızlık oranlarının LGS başarısını %11,8 oranında yordadığı tespit edilmiştir. 450 ve üzeri LGS puanı alan öğrencilerin devamsızlık yüzdeleri, 450 puanın altında kalan öğrencilerden belirgin şekilde farklılaşmıştır. Görüşmelerden elde edilen bulgular, devamsızlık nedenlerinin ailevi, kişisel ve akademik sebeplerden kaynaklandığını ortaya koymuştur. Bu çalışma, BİLSEM öğrencilerinin akademik başarılarını artırmak için devamlılık düzeyini etkileyen faktörlere yönelik müdahalelerin önemini vurgulamaktadır. Eğitim politikalarının geliştirilmesi ve özel yetenekli öğrenciler için daha etkili stratejiler oluşturulmasına rehberlik edecek özgün bulgular sunmaktadır. Anahtar Sözcükler: Özel Yetenekli Öğrenciler, BİLSEM Eğitim Programları, Akademik Başarı, Eğitime Devamsızlık, Liseye Geçiş SınavıThis study aims to examine the factors affecting the attendance of Science and Art Center (SAC) students in Düzce province and the impact of this attendance on their success in the High School Entrance Examination (HSEE) . The research was conducted using a mixed-methods design, incorporating both quantitative and qualitative data. Quantitative data were obtained from SAC archival records and analyzed based on LGS scores, attendance rates, and demographic information. Qualitative data were collected through semi-structured interview forms and analyzed using the thematic analysis method. The results of the study revealed a significant negative correlation between students' attendance rates and their HSEE scores. Additionally, it was found that attendance rates predicted HSEE success at a rate of 11.8%. The attendance percentages of students scoring 450 and above on the HSEE differed significantly from those scoring below 450. Findings from the interviews indicated that the reasons for absenteeism stemmed from familial, personal, and academic factors. This study highlights the importance of interventions targeting the factors influencing attendance levels to improve the academic performance of SAC students. It provides unique findings that can guide the development of educational policies and the creation of more effective strategies for gifted students
Atmospheric Trace Metal Exposure in a 60-Year-Old Wood: A Sustainable Methodological Approach to Measurement of Dry Deposition
Get PDFUrban trees are essential in improving environmental quality and enhancing human welfare in urban areas. They are being utilized increasingly as biomonitors of air and dust-borne heavy metals through dendrochemistry and comparative analytical methods. This study investigated the foremost concern essential nutrient metals, including aluminum (Al) and iron (Fe); also trace metals (cadmium (Cd), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), and lead (Pb)) in worldwide-distributed trees in units of mg kg(-1 )dry weight (d.w). For retrospective analysis, we hypothesized that its feasibility as a bioindicator of air pollution in D & uuml;zce, T & uuml;rkiye, among the tree species should be assessed. Digested tree wood samples were processed via inductively coupled plasma optical emission spectrometry (ICP-OES) for all metals to test this hypothesis. Pearson's correlation analysis and principal component analysis were utilized to determine the origin of elements. The results showed that (i) the mean concentrations of the species were presented to be Fe (156 mg kg(-1) d.w) > Al (100.56 mg kg(-1) d.w) > Cr (15.82 mg kg(-1) d.w) > Cu (12.43 mg kg(-1) d.w) > Pb (6.76 mg kg(-1) d.w) > Ni (5.98 mg kg(-1) d.w) > Co (2.16 mg kg(-1) d.w) > Cd (0.47 mg kg(-1) d.w); ii) analysis of the bioconcentration factor (BCF) and metal accumulation index (MAI) showed that the maximum BCF and MAI value was stored in the Cupressus arizonica (2.30 for Pb) and Robinia pseudoacacia (70.65) in all species; iii) the tree woods were also capable of discriminating between affected areas, as sites near industrial and vehicular traffic indicated higher metal content. For this reason, it can be deduced that C. arizonica wood is a potentially suitable sink of atmospheric metal
Padovan and Perrin hyperbolic spinors
Get PDFIn this study, we intend to bring together Padovan and Perrin number sequences, which are one of the most popular third-order recurrence sequences, and hyperbolic spinors, which are used in several disciplines from physics to mathematics, with the help of the split quaternions. This paper especially improves the relationship between hyperbolic spinors, both a physical and mathematical concept, and number theory. For this aim, we combine the hyperbolic spinors and Padovan and Perrin numbers concerning the split Padovan and Perrin quaternions, and we determine two new special recurrence sequences named Padovan and Perrin hyperbolic spinors. Then, we give Binet formulas, generating functions, exponential generating functions, Poisson generating functions, and summation formulas. Additionally, we present some matrix and determinant equations with respect to them. Besides, we construct some special equations that give relations between Padovan and Perrin hyperbolic spinors and Padovan and Perrin numbers. Further, we give a short introduction for (s, t)-Padovan and (s, t)-Perrin hyperbolic spinors in order to shed light on future studies.Scientific and Technological Research Council of Turkiye (TUBITAK)Open access funding provided by the Scientific and Technological Research Council of Turkiye (TUBITAK)
On paranormed sequence space arising from Riesz Euler Totient matrix
Get PDFIn this paper, we introduce a novel paranormed sequence space l(R Phi, p) constructed through the application of the Riesz Euler Totient matrix. We demonstrate that the spaces l(R Phi, p) and l(p) are linearly isomorphic. In addition, we identify the dual spaces associated with this sequence space and establish its Schauder basis