Zonguldak Bülent Ecevit University Institutional Repository
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Simultaneous Raman and FTIR‐ATR Spectroscopy Techniques Combined With Chemometrics: Characterization and Comparison of Donkey Milk Adulteration
No full textABSTRACTDue to its nutritional qualities, donkey milk is a newly popular food. Because it has a high added value, it may be adulterated with using cheaper milks, like cow milk. This study has investigated a rapid method for the authentication of pure donkey milk using Raman and FTIR‐ATR spectroscopy and comparison of the methods. Three preprocessing methods were applied to the spectra. The results show that donkey milk has lower fat and protein content compared with cow milk. Notably, Raman spectroscopy successfully distinguishes donkey and cow milk according to the presence and absence of β‐carotene. Principal component analysis demonstrated a distinct separation between cow, adulterated donkey, and donkey. The variance value of 90.30% (PC1 = 72.76, PC2 = 17.53) is obtained from the first and second PCs for Raman data, and the variance value of 89.67% (PC1 = 65.25, PC2 = 24.41) is obtained from the first and second PCs for FTIR data. The Raman data could be used to separate donkey and cow milks, whereas the FTIR data were insufficient. It was observed that adulterated species could be separated between classes with Raman and FTIR. In the FTIR spectrum, there is a broad peak due to water, which accounts for about 87% of the milk composition, but this water peak is not included in the Raman spectrum. The results demonstrate the potential of Raman spectroscopy as a rapid and reliable method and suggest that it can be used as a nondestructive analytical tool for adulteration detection in donkey milk.</jats:p
Mitigating Duty Cycle Limitation and Maximizing DC Voltage Gain in Switch Mode Power Supplies Utilizing Tapped-Inductor Topology: A Case Study with Buck Converter Analysis
No full textThis paper presents a comparative analysis of tapped inductor (TI) buck converters versus conventional buck converter topologies, highlighting the advantages of TI buck converters. The primary motivations for using TI DC-DC converters in step-down applications, such as battery charging and photovoltaic emulator design, include significant input-to-output voltage differences resulting in low converter duty cycles, favorable peak-to-average current ratios, and overall conversion efficiency. In conventional buck converters, the DC voltage gain is determined solely by the duty cycle, leading to linear output voltage variation with the duty cycle for a given input voltage. In contrast, the DC voltage gain of TI buck converters depends on both the duty cycle and the turns ratio. While the operating principles of conventional and TI buck converters are similar, the TI topology offers a wider range of voltage step-down options based on the TI turns ratio. System characteristics are analyzed using the transfer function model for ease of use and pole-zero detection. The state-space averaging method, known for its simplicity, is applied with AC small signal analysis to derive transfer functions for both converter types. The results show that the use of a tapped rather than a conventional inductor does not alter the step-down characteristics of the conventional buck converter. Moreover, any DC voltage gain consistent with the conventional buck converter condition can be achieved at any duty cycle value by appropriate selection of the turn’s ratio, increasing flexibility in converter design.</jats:p
The impact of social media addiction on pregnancy stress and prenatal attachment
No full textThe purpose of this study is to determine the impact of social media addiction on pregnancy stress and prenatal attachment. The study was conducted between November 2023 and April 2024 with a sample of 277 pregnant women. This descriptive, cross-sectional, and correlational study utilized several instruments, including the Demographic Information Form, the Social Media Addiction Scale-Adult Form (SMAS-AF), the Fear of Missing Out Scale (FoMO), the Pregnancy Stress Rating Scale (PSRS), and The Prenatal Attachment Inventory (PAI). The findings revealed that the majority of the participants used social media to gain information related to their pregnancy (60.3%) and childbirth (46.6%). It was observed that the participants had a moderate level of social media addiction (40.56±9.82). The study found that as levels of social media addiction and FoMO increased, pregnancy stress also increased. Additionally, no significant relationship was found between social media addiction and prenatal attachment, although a higher level of FoMO was associated with a decrease in prenatal attachment. It is recommended that the number of healthcare professionals who provide accessible education and follow-up services to pregnant women be increased. Moreover, preventive and supportive environments should be established within healthcare services to guide the use of social media during pregnancy. </jats:p
The Role of Digitalisation and New Technologies in the Tourism Sector
No full textThe tourism sector is predicated on the premise that direct human interaction and physical experiences are the most effective means of enabling people to learn about different cultures, discover new places, and create unforgettable memories . The rapid development of technology in recent years has precipitated a significant transformation process in the tourism sector. In this context, the advent of digitalisation and new technologies, in particular the metaverse, artificial intelligence (AI), and robotic process automation (RPA), is precipitating radical changes in the tourism sector. The objective of this study is to provide a comprehensive overview of the transformative impact of these technologies on the tourism sector. In particular, it seeks to examine how digitalisation can enhance the tourism experience, improve service delivery, and create new opportunities for growth and innovation.</jats:p
İlkokul Öğrencilerinin Peritekstual Okuma ile Soru Sormaya Yönelik Tutumları Arasındaki İlişkinin İncelenmesi
No full textBu araştırma, ilkokul 4. sınıf öğrencilerinin peritekstual okuma ile soru sormaya yönelik tutumları arasındaki ilişkiyi incelemeyi amaçlamaktadır. İlişkisel tarama modeliyle yürütülen çalışma, Ankara ili Yenimahalle ilçesindeki üç devlet okulunda öğrenim gören 373 öğrenci üzerinde gerçekleştirilmiştir. Veriler, Peritekstual Okuma Düzeyi Belirleme Ölçeği ve Soru Sormaya Yönelik Tutum Ölçeği kullanılarak toplanmıştır. Verilerin analizinde bağımsız örneklemler t-testi, ANOVA, korelasyon ve regresyon analizleri kullanılmıştır. Bulgular, öğrencilerin genel peritekstual okuma düzeylerinin orta seviyede olduğunu, özellikle görsel unsurları okuma becerisinde diğer alanlara göre daha yüksek performans sergilediklerini ortaya koymuştur. Cinsiyet ve kardeş sayısı gibi değişkenler açısından peritekstual okuma düzeyi anlamlı bir farklılık göstermezken, kız öğrencilerin metin içi peritekstual unsurları okuma düzeylerinin erkeklere göre daha yüksek olduğu belirlenmiştir. Peritekstual okuma düzeyi ile soru sormaya yönelik tutum arasında pozitif yönde düşük düzeyde anlamlı bir ilişki bulunmuş, peritekstual okuma düzeyinin öğrencilerin soru sorma tutumlarını yordadığı görülmüştür. Araştırma sonuçları, öğrencilerin eleştirel düşünme ve sorgulama becerilerinin geliştirilmesinde peritekstual okuma becerisinin önemli bir katkı sağlayabileceğini göstermektedir. Bu bağlamda, okuma alışkanlıklarını geliştirmek için öğrencilere peritekstual okuma unsurlarını tanıtan etkinlikler yapılması ve ders materyallerinde peritekstual öğelere daha fazla yer verilmesi önerilmektedir.</jats:p
Evaluation of the Microstructural, Mechanical, and Corrosion Behavior of BN-, B4C-, and FeB-added Distaloy AE Composites Produced by High-Energy Ball Milling and Hot-Pressing
No full textEnhancing the diagnostic specificity of exercise ECG testing in obstructive coronary artery disease: the role of the Selvester QRS score
No full text Background Exercise ECG testing is a widely used, noninvasive tool for detecting obstructive coronary artery disease (OCAD). However, its diagnostic performance is often limited by low specificity, leading to false-positive results and unnecessary invasive procedures. Objective This study aims to assess the potential of combining the Selvester QRS score with exercise ECG to enhance diagnostic specificity for OCAD in patients with suspected stable angina. Methods This retrospective study included 203 patients who presented with chest pain, underwent exercise ECG and were assessed for OCAD by coronary angiography or computed tomography angiography. Receiver operating characteristic analysis identified the optimal Selvester QRS score cutoff and assessed the diagnostic performance of exercise ECG and the combined model. Multivariable logistic regression was performed in the exercise ECG positive and negative groups. Results Of the 203 patients, 116 were diagnosed with OCAD. The optimal Selvester QRS score cutoff was ≥3, with a sensitivity of 83.6% and a specificity of 93.1%. The combination of a positive exercise ECG and a Selvester QRS score ≥3 achieved the highest specificity (98.9%). Regression analyses showed that Selvester QRS score ≥3 was an independent predictor of OCAD, even in patients with negative exercise ECG results (adjusted odds ratio: 7.018; P < 0.001). Conclusion The Selvester QRS score can improve the specificity of the exercise ECG in detecting OCAD in patients with suspected stable angina. This approach has the potential to reduce false positives and unnecessary invasive procedures by improving risk stratification. </jats:sec
Artificial neural network prediction of TiO2-doped chitosan micro/nanoparticle size based on particle imaging measurements
No full textİkinci Dünya Savaşı Sırasında İran'da Bulunan Alman Vatandaşları Meselesi
No full textİkinci Dünya Savaşı henüz başlamadan önce İran’da, Alman mühendis, teknisyen, tüccar, öğretmen ve teknik personel bulunuyordu. Sovyet Rusya’ya göre, İran’da bulunan Almanlar, İran vasıtasıyla Rusya’nın Kafkasya’da bulunan petrol alanlarını ele geçirebilirlerdi. Ayrıca Rusların sıcak denizlere inme planlarını sekteye uğratabilirlerdi. İngilizlere göre ise İran’da bulunan Almanlar, Hindistan sömürgelerine ve Güneybatı Anglo-İran Petrol Şirketi’nin çıkarlarına zarar verebilirlerdi. Bu sebeple savaş başladıktan sonra bu iki devlet, Almanların İran’dan çıkarılmasını istediler. Ancak İran hükümeti önce bu talebi red etse de 25 Ağustos 1941’de toprakları Sovyet Rusya ve İngiltere tarafından işgal edilince Almanları ülkeden çıkarmak zorunda kaldı. Bu çalışmanın amacı, İkinci Dünya Savaşı sırasında İran’da bulunan Almanların ülkeden çıkarılmalarını talep eden Sovyet Rusya ve İngiltere’nin İran hükümeti üzerindeki baskılarını telif-tetkik eserler ışığında incelemektir.</jats:p
Spatiotemporal Dynamics of Carbon Storage in Utah: Insights from Remote Sensing and Climate Variables
No full textClimate change mitigation relies heavily on understanding carbon storage dynamics in terrestrial ecosystems. This study examines the relationship between carbon storage (kg/m2) and various climatic variables, including precipitation, temperature, humidity, and radiation. Machine learning models such as Random Forest (RF), Gradient Tree Boost (GTB), Artificial Neural Networks (ANN), Support Vector Machines (SVM), and Multiple Regression (MR) were applied. Among these, Random Forest exhibited the highest explanatory power (R2 = 0.95, Adj. R2 = 0.75, F-score = 4.721, Accuracy = 0.67), while ANN showed the highest predictive accuracy (Accuracy = 0.80). The results underline the significant role of climatic factors in shaping carbon dynamics, emphasizing the integration of machine learning-based models in carbon capture and sequestration (CCS) strategies. Furthermore, carbon storage dynamics in Utah from 1991 to 2020 were analyzed using remote sensing data and multiple regression models. Carbon storage was found to be highest in forested areas, wetlands, and natural grasslands, while agricultural and wildfire-affected zones exhibited lower carbon stocks. Climatic factors, particularly precipitation, temperature, and humidity, were identified as significant drivers of carbon sequestration, with moderate precipitation and favorable temperatures enhancing carbon retention. The study highlights the importance of region-specific CCS strategies, which rely on accurate climate-driven carbon storage assessments, for ensuring sustainable resource management and mitigating anthropogenic climate impacts.</jats:p