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Generalized Fractional Integral Inequalities Derived from Convexity Properties of Twice-Differentiable Functions
Get PDFThis study presents novel formulations of fractional integral inequalities, formulated using generalized fractional integral operators and the exploration of convexity properties. A key identity is established for twice-differentiable functions with the absolute value of their second derivative being convex. Using this identity, several generalized fractional Hermite-Hadamard-type inequalities are developed. These inequalities extend the classical midpoint and trapezoidal-type inequalities, while offering new perspectives through convexity properties. Also, some special cases align with known results, and an illustrative example, accompanied by a graphical representation, is provided to demonstrate the practical relevance of the results. Moreover, the findings may offer potential applications in numerical integration, optimization, and fractional differential equations, illustrating their relevance to various areas of mathematical analysis.King Khalid UniversityPrincess Nourah bint Abdulrahman University [PNURSP2025R337][RGP.2/82/45]This research was funded by King Khalid University, Grant (RGP.2/82/45) and Princess Nourah bint Abdulrahman University, Grant (PNURSP2025R337)
Golden score period in high-level judo competitions: the effect of the scores and penalties at the real contest time
Get PDFThis study investigated the effect of scores and penalties in real contest time on the contest results in the golden score period. Of 6872 official contests at 10 different high-level competitions, 1414 contests with a golden score (21%) were included. Analyses for sex, weight category and rounds were performed with total match duration. Scores and penalties were recorded separately for real contest time and golden score period. Mutual waza-ari at real time (first 4 min) caused the high rate of matches ending with a score (p < 0.05). The rate of receiving a shido was higher among defeated athletes during the real contest time (p < 0.05). The rate of winning a contest with score during the golden score period was lower than winning a contest with hansoku-make in heavyweight categories. The contests more likely ended with scores and less likely ended with hansoku-make for men than women (p < 0.05). The results showed that the way the contest ended was different between sexes and among weight categories during the golden score period. Receiving a shido during the real contest time can lead to defeat in the golden score, thus athletes should be careful of presenting active judo and refraining from any action leading to penalties
Effects of silica fume on portland cement hydration and mechanical properties
Get PDFİnşaat sektörü, nüfus artış oranına paralel olarak hızla büyümektedir. Bu büyümeyle birlikte beton ve betonun önemli bir bileşeni olan çimento ihtiyacı da her geçen gün daha fazla artmaktadır. Portland çimento üretimi küresel karbondioksit emisyonlarının %5-7'sinden sorumludur ve ekolojik dengeye önemli ölçüde zarar vermektedir. Ayrıca endüstride tüketilen enerjinin yaklaşık %5'i çimento üretimindendir. Bu yüzden hem ciddi çevresel endişeler hem de enerji maliyetlerini azaltmak için çimento üzerine araştırmalar yoğun olarak devam etmektedir. Bu araştırmalar özellikle endüstriyel atık olarak değerlendirilen puzolanik malzemelerin çimento ikame malzemesi olarak kullanılması üzerine yoğunlaşmaktadır. Bu malzemelerden biri olan silis dumanı, çimento ve betonun genel performansını önemli ölçüde arttırması sebebiyle en çok araştırılan yüksek kaliteli tamamlayıcı çimento malzemeleri arasında yer almaktadır. Bu çalışmada, silis dumanı ikameli çimentoların hidratasyon reaksiyonları ve mekanik özellikleri araştırılacaktır. Çalışmanın ilk bölümünde silis dumanı ve CEM I 42,5 R tipinde Portland çimentosunun fiziksel, kimyasal, mineralojik, moleküler ve mikro yapı karakterizasyonları tespit edilmiştir. İkinci aşamada Portland çimento içerisine ağırlıkça %0, %2,5, %5, %7,5 ve %10 oranlarında silis dumanı ikame edilerek 5 tip çimento hazırlanmıştır. Üçüncü aşamada bu çimentolarla üretilen hamurların standart çimento deneyleri ile su ihtiyaçları, priz süreleri ve hacim genleşmeleri belirlenmiştir. Dördüncü aşamada bu hamurların 28. gündeki hidratasyon mekanizmaları X-ışını kırınımı, fourier dönüşümlü kızılötesi spektroskopisi, eş zamanlı termal analiz, taramalı elektron mikroskobu ve enerji dağılımlı X-ışını spektroskopisi gibi ileri analitik tekniklerle incelenmiştir. Son aşamada 2., 7., 28. ve 90. günlerde çimento harçlarının basınç dayanımları belirlenmiştir. Sonuçlar, harçların basınç dayanımlarının tüm hidratasyon yaşlarında silis dumanı ikamesiyle iyileştirilebileceğini göstermiştir. Bu durum, nano boyutlu parçacıklara ve geniş yüzey alanına sahip silis dumanının, C3S ve C2S'nin hidratasyonunu ve kalsiyum silikat hidrat fazının oluşumunu desteklemesinden kaynaklanmaktadır. Bununla birlikte silis dumanı ile serbest kireç reaksiyona girerek ilave kalsiyum silikat hidrat jeli oluşturarak çimentolu kompozitlerin mikro yapısını yoğunlaştırmış ve boşlukları azaltmıştır. Bu bulgular, silis dumanının Portland çimentosuna ikame edildiğinde, çevre dostu, uygun maliyetli ve sürdürülebilir bir çözüm sağlanabileceğini göstermektedir. Ayrıca %10 oranında silis dumanı ikamesi ile üretilecek çimentoların, bir üst dayanım sınıfı olan 52,5 R tip çimentonun tüm gereklerini karşıladığı standart deneyler sonucunda belirlenmiştir.The construction sector is growing rapidly in parallel with the population growth rate. With this growth, the need for concrete and cement, which is an important component of concrete, is increasing day by day. Portland cement production is responsible for 5-7% of global carbon dioxide emissions and significantly harms the ecological balance. In addition, approximately 5% of the energy consumed in the industry is from cement production. Therefore, research on cement continues intensively in order to reduce both serious environmental concerns and energy costs. This research focuses especially on the use of pozzolanic materials, which are considered as industrial waste, as cement replacement materials. One of these materials, silica fume, is among the most researched high-quality supplementary cement materials due to its significant increase in the general performance of cement and concrete. In this study, the hydration reactions and mechanical properties of silica fume-substituted cements will be investigated. In the first part of the study, the physical, chemical, mineralogical, molecular and microstructure characterizations of silica fume and CEM I 42.5 R type Portland cement were determined. In the second stage, 5 types of cement were prepared by substituting silica fume into Portland cement at the rates of 0%, 2.5%, 5%, 7.5% and 10% by weight. In the third stage, water requirements, setting times and volume expansions of the pastes produced with these cements were determined by standard cement tests. In the fourth stage, the hydration mechanisms of these pastes on the 28th day were investigated by advanced analytical techniques such as X-ray diffraction, fourier transform infrared spectroscopy, simultaneous thermal analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy. In the last stage, the compressive strengths of the cement mortars on the 2nd, 7th, 28th and 90th days were determined. The results showed that the compressive strengths of the mortars could be improved by substituting silica fume at all hydration ages. This is due to the fact that silica fume, with its nano-sized particles and large surface area, supports the hydration of C3S and C2S and the formation of calcium silicate hydrate phase. However, silica fume and free lime reacted to form additional calcium silicate hydrate gel, thus densifying the microstructure of cementitious composites and reducing voids. These findings show that when silica fume is substituted for Portland cement, an environmentally friendly, cost-effective and sustainable solution can be provided. In addition, it has been determined as a result of standard tests that cements produced with 10% silica fume substitution meet all the requirements of the 52.5 R type cement, which is a higher strength class
Synthesis of novel silane-modified graphene oxide / polymer hybrid nanocomposite
Get PDFGrafen oksit bazlı polimer nanokompozitler, sahip oldukları termal, elektriksel, mekanik, antibakteriyel, korozyon ve aşınma direnci özelliklerinden ötürü endüstriyel uygulama alanına (inşaat, biyomedikal, otomotiv, ambalaj, enerji, savunma, tıp, biyosensör uygulamaları…) sahip ilgi gören malzemelerdir. Lisansüstü tez çalışma kapsamında, çeşitli analitlerin tespiti için potansiyel biyosensörler olarak ve/veya çeşitli hastalık etkeni patojenlere karşı potansiyel antimikrobiyal ajanlar olarak, 5 (beş) yeni silan modifiyeli grafen oksit / polimer hibrit nanokompozitler, template olarak 3-kloropropil-fonksiyonelleştirilmiş silika jel, poli(propilen glikol)bis(2-aminopropil eter) / 4-formil-3-metoksifenoksimetil)polistiren ve salisilaldehit / 5-metilsalisilaldehit / tiyosemikarbazit / 4-metil-3-tiyosemikarbazitin kondenzasyon reaksiyonu ile sentezlendi. Yeni grafen oksit-polimer hibrit nanokompozitlerin yapısı element analizi, fourier dönüşümlü kızılötesi spektroskopisi, jel geçirgenlik kromatografisi, taramalı elektron mikroskobu-enerji dağılımlı X-ışını spektroskopisi, X-ışını fotoelektron spektrometresi, termogravimetrik ve diferansiyel termal analizi ile karakterize edildi. Anahtar Sözcükler: Grafen oksit, 3-kloropropil-fonksiyonelleştirilmiş silika jel, polimer, tiyosemikarbazit, aldehitGraphene oxide based polymer nanocomposites are materials of interest with industrial applications (construction, biomedical, automotive, packaging, energy, defense, medicine, biosensor applications…) due to their thermal, electrical, mechanical, antibacterial, corrosion, and wear resistance properties. Within the scope of the graduate thesis study, 5 (five) novel silane modified graphene oxide/polymer hybrid nanocomposites were synthesized by the condensation reaction of 3-chloropropyl-functionalized silica gel, poly(propylene glycol)bis(2-aminopropyl ether)/4-formyl-3-methoxyphenoxymethyl)polystyrene and salicylaldehyde/5-methylsalicylaldehyde/thiosemicarbazide/4-methyl-3-thiosemicarbazide as templates, as potential biosensors for the detection of various analytes and/or as potential antimicrobial agents against various disease-causing pathogens. The structure of the novel graphene oxide-polymer hybrid nanocomposites was characterized by elemental analysis, Fourier transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy-energy dispersive X-ray spectroscopy, X-ray photoelectron spectrometry, thermogravimetric, and differential thermal analysis
The Relationship Between Anthropometric Characteristics, Chronological Age, and Training Age with Speed, Agility, and Explosive Power in Handball Players
Get PDF(1) Background: Research examining the combined influence of anthropometric characteristics, chronological age, and training age on motor performance in handball is limited. Given the sport's demands and the participation of both adolescent and adult athletes, understanding these relationships is essential for talent identification, personalized training, and long-term athlete development. This study aimed to explore how these variables affect motor performance indicators such as speed, agility, and explosive power. (2) Methods: A cross-sectional study was conducted involving 29 male handball players. Anthropometric data (height and body weight), chronological age, and training age were collected. Motor performance was assessed using a 30 m sprint, a vertical jump test, and an agility test. (3) Results: Chronological age showed a strong positive correlation with training age (r = 0.819), and moderate correlations with height, body weight, vertical jump, agility, and sprint time. Training age was moderately correlated with vertical jump (r = 0.465) and agility (r = 0.439). Height and body weight were positively associated with sprint time. BMI exhibited low but consistent correlations with all motor tests. Regression analysis revealed that height significantly predicted sprint performance (beta = 0.401, p = 0.033), while BMI was not a significant predictor. No significant regression models were found for agility or vertical jump performance. (4) Conclusions: The results suggest that both chronological and training age influence certain aspects of motor performance in handball players. Height may serve as a useful predictor of sprint ability, but anthropometric indicators such as BMI appear insufficient for explaining performance in agility or explosive power tasks. These findings support the use of multidimensional and individualized approaches in athletic assessment and training design
Examining of High School Students’ Internet Addiction Levels in Terms of Sports Participation and Various Variables
Get PDFThe purpose of this study is to investigate the internet addiction levels of high school students with respect to the variables of sports participation, gender, grade level, and type of school. A total of 804 students (n=387 female, n=417 male) from various high schools in Düzce Province voluntarily participated in the research during the spring semester of the 2023–2024 academic year. Data were collected using a Personal Information Form developed by the researchers and the Young Internet Addiction Test Short Form, originally developed by Young (1998), shortened by Pawlikowski, Altstötter-Gleich, and Brand (2013), and adapted to Turkish by Kutlu, Savcı, Demir, and Aysan (2016). The SPSS program was used for data analysis, including mean, percentage, and frequency calculations. As the data showed normal distribution, independent samples t-test was used for two-group comparisons, and One-Way ANOVA was used for comparisons among more than two groups. Results showed that no significant differences were found based on gender, grade level, or school type (p>0.05). However, a significant difference was found in favor of students who participate in sports (p<0.05), indicating that students engaged in sports have lower levels of internet addiction. Therefore, it can be suggested that sports may serve as an effective tool in reducing internet addiction. Future studies could experimentally test this effect at primary and secondary school levels
Abusive head trauma in turkey and impact of multidisciplinary team establishment efforts on case finding and management: preliminary findings (vol 15, 24, 2016)
Get PDFAssessing the Effect of Land Use Changes on Carbon Storage Using Forest Management Plan and Remote Sensing Data
Get PDFThis study evaluated the land use land cover (LULC) classes that were obtained from the forest management plans (FMP) of the Beykoz planning unit and generated from Landsat images for 1992 and 2012. FMPs increased in coniferous forest areas (18.64%) and broadleaved forest areas (1.03%), whereas a decrease (12.79%) was observed in other areas within 20 years. Eight different vegetation indices (VI) obtained from satellite imagery were used for land use classification. The results of the study showed that the RVI had the highest overall accuracy (71%-72%) and kappa value (0.56-0.59) in both study periods. While stored carbon estimated from the FMPs decreased by 46.2% within 20 years due to regeneration of mature forests with clear-cutting, stored carbon assessed from the NDVI map increased by 1.3%. A positive correlation was found for the stored carbon estimated from the FMP and NDVI maps at a rate of 95.2% (R-2=0.90) in 1992 and 54.4% (R-2=0.29) in 2012. Although there was a high correlation between the carbon storage data obtained using the two methods, there was also a significant difference (p < .05). In addition, the effect size was determined to be very large in 1992, and large in 2012
Strontium-Modified TiO2 Nanotubes for Efficient Photodegradation of Formic Acid
Get PDFThis study explores the enhancement of photocatalytic activity in one-dimensional TiO2 nanotubes (TiNT) through strontium (Sr) doping, using the incipient impregnation method to introduce Sr concentrations ranging from 0.2 to 1.0 wt%. The photocatalytic performance of the resulting xSr-TiNT composites was evaluated by examining the degradation of formic acid under UV irradiation. The materials were characterized using N2 physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis, Raman spectroscopy, photoluminescence (PL), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effective surface area was determined by XPS, revealing a significant increase in surface area with Sr loading, which correlates with enhanced photocatalytic performance. This enhancement in surface area is in agreement with the observed expansion of the unit cell volume in presence of Sr. Results show that a small amount of Sr (0.2 wt%) enhances the generation of oxygen vacancies and Ti3+ species, leading to increased photocatalytic activity. The degradation followed the Langmuir-Hinshelwood model, with the highest degradation rate observed at 0.8 wt% Sr, showing a 3.36-fold increase compared to pristine TiNT. At higher Sr concentrations, the proportion of oxygen vacancies and Ti3+ defects decreased due to the formation of Ti-O-Sr moieties. Additionally, the polarization effect induced by Sr doping improved charge separation, reducing electron-hole recombination and further enhancing photocatalytic efficiency. These findings emphasize the critical role of Sr concentration, effective surface area, and unit cell volume expansion in tuning the photocatalytic properties of TiO2 nanotubes, with an optimum Sr loading of 0.8 wt% leading to improved photocatalytic activity.Imam Abdulrahman Bin Faisal University [IF-2020-018-BASRC]Deputyship for Research & Innovation, Ministry of Education in Saudi ArabiaFinancial support was provided by the Deputyship for Research & Innovation, Ministry of Education in Saudi Arabia under project number (IF-2020-018-BASRC) at Imam Abdulrahman bin Faisal University's Basic and Applied Scientific Research Center (BASRC)
Cynanchica paphlagonica (Rubiaceae, Rubieae), a new species from Türkiye based on morphology and phylogenetic data
Get PDFCynanchica paphlagonica from Kastamonu Province (T & uuml;rkiye) is described and illustrated. Detailed morphological observations and phylogenetic analysis place C. paphlagonica within a small monophyletic group of Anatolian-Pontic species. While the new species more closely resembles C. stricta in general morphology, it is distinguished by its habit, and inflorescence, corolla and mericarp characters. Cynanchica paphlagonica inhabits limestone cliffs and rocks, with its distribution limited to the P & imath;narba & scedil;& imath; district in Kastamonu Province. A single population comprising approximately 80 individuals is known so far, leading to its classification as Endangered (EN) following IUCN Red List Criteria.Bartimath;n University (BAP) [2019-Fen-B-005]We thank Dr. Ioannis Kokkoris (University of Patras) for the preparation of the distribution map, and Dr. Konstantina Koutroumpa (BGBM) for her help with software facilities. This research was supported by Bart & imath;n University (BAP; project number: 2019-Fen-B-005)