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A356 alüminyum alaşımının dökümünde katılaşma zamanı ve Nb ilavesinin mikroyapıya etkisinin incelenmesi
No full textAlüminyum alaşımları hafiflik, korozyon direnci, elektrik ve ısı iletkenliğinin yüksek olması yüksek dayanım, sünek olması gibi özelliklerinde dolayı oldukça önemli bir mühendislik malzemesidir. Bu sebeple; otomotiv, havacılık, savunma, uzay endüstrisi, makine imalat, gıda endüstrisi gibi birçok alanda yaygınca kullanım bulmaktadır. Özellikle otomotiv sanayi ve yüksek teknoloji gereksinimi olan birçok sektörde kullanımı artmakla birlikte kalite gereksinimleri de artmaktadır. Alüminyum döküm alaşımlarından kalite beklentisindeki artışa bağlı olarak farklı alaşım elementi ilaveleri ile dökümler yapılması ve üretimde yeni teknoloji kullanımları üzerinde çalışmalar devam etmektedir. Bu çalışmada A356 alüminyum döküm alaşımına %0.03, %0.06 ve %0.1 Niyobyum ilavesinin değişen kesitler içeren kokil kalıba dökümünde mikroyapı üzerindeki etkileri incelenecektir. Çalışmada ergitme, sıvı metal temizleme, kokil kalıba döküm, metalografik numune hazırlama, mikroyapı inceleme ve imaj analiz teknikleri kullanılmıştır. Sonuçlar incelediğinde katılaşma zamanına ve Nb ilave miktarına bağlı olarak döküm mikro yapılarında değişimler olduğu gözlenmiştir
An Archaic Compound Suffix in Old Uyghur: plus DXrtI
No full textAs many world languages, Turkic also has simple suffixes in terms of structure, as well as complex suffixes with controversial origins. Although some of these suffixes have been systematized and bound to certain rules, the emergence of some suffixes still remains a mystery. Old Uyghur, which is one of the historical periods of the Turkic language, has such an undeciphered suffix. The compound suffix of +DXrtI has been evaluated by some researchers to date; however, no definite conclusion has been reached regarding its origin and function. For this purpose, various structures in Altaic languages will be examined and a connection will be made between this suffix and the 'extraordinary' examples seen in Old Uyghur
Polarization Insensitive and Thin Metamaterial Absorber Performed in High-Frequency 5G Bands
No full textA variety of fascinating applications, including 5G communication devices, high-speed data transfer, and large-scale Internet of Things (IoT), make life easier with 5G technology. Despite the 5G’s superior features, the percentage of electromagnetic (EM) waves in the environment execute a significant increase, unpleasantly. Broadband metamaterial absorbers are an appealing alternative to gather these unwanted signals. This study aims to numerically investigate a broadband metamaterial absorber (MMA) in the 5G high-frequency spectral range with the metasurface formed with coupled resistors. In addition, the 24.25-27.5GHz frequency range, one of the high-frequency 5G bands used by selected countries such as the European Union and China, was preferred. The minor aim of this study is that the usage of coupled elements as resistors may have the ability to increase the absorption bandwidth and magnitude. Comprehensive simulations were performed using the finite integration technique (FIT) utilized by the CST Microwave Studio program to investigate the absorber performance and other relevant parameters. The unit cell design is created metal-substrate-metal structures as asymmetric, single-layer, and easy to implement. The absorption responses are investigated according to the oblique incidence angle, polarization angle for TE &TM modes. The suggested MMA provided an absorbency response above 87.6% in the frequency range 24.20-27.30GHz under normal incidence. Moreover, to comprehend the physical mechanism on absorption, the top and bottom surfaces of the absorber's electric field and surface current distributions are assessed. The designed MMA resulting in relatively high performance and polarization insensitive is helpful for electromagnetic interference (EMI) shielding of 5G signals in the FR2/mmWave frequency regime
Reflection of recitation differences on meaning in Ruhu'l-Beyan interpretation
No full textLisansüstü Eğitim Enstitüsü, Tefsir Ana Bilim Dalı, Tefsir Bilim DalıBu çalışmada, Bursevî'nin Ruhu'l-Beyan tefsirinde okunuş farklılıklarına değinilen ayetler tespit edilerek bunların manaya yansımaları gösterilmiştir. Ayrıca yazarın okunuşunu verip hangi kıraate ait olduğunu bildirmediği ayetlerin hangi imamlar tarafından farklı okunduğu ilgili kaynaklardan tespit edilerek kayda geçirilmiştir. Bununla birlikte anlam bütünlüğü sağlamak ve farklı okunuşun anlam üzerindeki tesirini tam yansıtabilmek adına, yer yer, ayetlerin siyak ve sibakları da dikkate alınarak değerlendirmeleri yapılmıştır. Aynı şekilde, ilgili ayetteki kıraat faklılığının anlama etkisini yansıtabilmek adına farklı müfessirlerin konu hakkındaki değerlendirmelerine de, ihtiyaç duyuldukça, yer verilmiştir.In this study, the verses in which reading differences are mentioned in Bursevî's Ruhu'l-Beyan commentary were identified and their reflections on meaning were shown. In addition, the verses that the author gave the reading but did not specify which recitation they belonged to were determined and recorded from relevant sources by which imams read them differently. However, in order to ensure semantic integrity and to fully reflect the effect of different readings on the meaning, the verses have been evaluated, taking into account their siyak and sibak. Likewise, the evaluations of different commentators on the subject are included, when necessary, in order to reflect the understanding effect of the difference in recitation in the relevant verse
District heating based on exhaust gas produced from end-of-life tires in Erzincan: Thermoeconomic analysis and optimization
No full textThis paper presents the thermoeconomic analysis and optimization of the Erzincan Waste Tire Recycling and Power Plant (EWTRPP) in Turkey and its waste heat-based district heating (DH) system. A thermoeconomical method, namely the specific exergy costing (SPECO), is applied to allocate cost flows through subcomponents of an actual existing plant. Besides, the obtained thermoeconomic results are improved by using an optimization method, namely non-dominant sorting genetic algorithm (NSGA-II), considering the temperature of the exhaust gas discharged to the atmosphere (T25), the thermal conductivity value of the insulation material (ki) and pipe roughness value (s). The energy and exergy efficiencies of the existing plant are found to be 27.37% and 35.57%, respectively, considering the data of the actual plant. Moreover, the energy and exergy efficiencies of the waste heat-based DH system are found to be 43.08% and 55.99%, respectively. The total cost rate of the overall system is deduced 13.98 /h, respectively. Furthermore, it is also proposed that 1304 dwellings can be heated owing to the DH system utilizing the existing exhaust gas
Investigation of emotion regulation skills, salivary apelin, and serotonin levels in children in Turkiye: a cross-sectional study
No full textPurpose: Little is known about the relationship between apelin and serotonin in emotion regulation. This study aimed to examine children's emotional regulation skills and salivary apelin and serotonin levels. Methods: This is a cross-sectional study performed in Turkiye. The research was completed with the participation of 146 children, 8-10 years old, from the general population. Emotion Regulation Skills Scale for Children (CERS) was used to assess children's levels of emotion regulation skills. Apelin and serotonin levels were examined by ELISA technique in saliva samples obtained from children. Results: A statistically significant correlation was found between the mean total score of the CERS and the mean apelin and serotonin levels (p < .01). We found that females had higher emotion regulation skills compared to males, older higher than younger ones (p < .01). The regression analysis results show that age and gender together explain 50.5% of the variance in CERS scores, while apelin and serotonin together explain 35.8% of the variance. When all four variables (age, gender, apelin, and serotonin) are included in the model, they explain 51.3% of the variance in CERS scores. Conclusion: Older age and female gender explained most of emotion regulations skills.The authors thank the children for their contribution to the study
Microwave hydrodistillation of Pelargonium graveolens L'Her leaves: Essential oil profile, phytochemical composition of wastewater, histo-anatomical structure
No full textBy-products with remarkable bioactive properties are formed in extraction processes of essential oils from plant materials. In present study, it was aimed to determine the concentration of individual phenolic and organic acid compounds by LC-MS/MS of the by-product (wastewater) collected after the essential oil isolation from Pelargonium graveolens L. and to determine some bioactive properties of this by-product. In addition, the chemical analysis and antibacterial activity of the essential oil extracted from P. graveolens were determined and the histo-anatomical characterization of the glandular trichomes in the leaf sample was performed. As a result, quercetin (95862.22 mu g/kg), myricetin (59834.32 mu g/kg) and rutin (36522.90 mu g/kg) were the phenolic compounds determined in the highest concentrations in the by-product extracted using two different extraction techniques (non-hydrolysis and hydrolysis methods). Moreover, the individual organic acids of the by-product screened in LC-MS/MS was found to be 4487.17 mg/kg in total. When the essential oil component profile of the plant sample was examined, the citronellol (38.78%) compound was found to be dominant, and it was also detected that the essential oil had remarkable bioactive properties. In conclusion, it can be stated that both the essential oil obtained from P. graveolens and the by-product obtained during essential oil isolation can be considered as a source of some bioactive components in many different industrial applications.Scientific Research Projects Coordination Unit of Istanbul University [34977, FBG-2022-39099]This study was funded by Scientific Research Projects Coordination Unit of Istanbul University (Project number: 34977 and FBG-2022-39099) and some results in this study are obtained from Gizem Tuerer's master's thesi
New moving frames for the curves lying on a surface
No full textIn this article, three new orthogonal frames are defined for the curves lying on a surface. These moving frames, obtained based on the Darboux frame, are called Osculator Darboux Frame, Normal Darboux Frame and Rectifying Darboux Frame, respectively. Also, the Osculator Darboux Frame components and curvatures are calculated for a presented example
Sosyal Bilgiler Dersi Öğretim Programı ve Sosyal Bilgiler Ders Kitaplarında Tüketim Kültürü ve Reklamcılığın İşlenişi
No full textBu çalışma ile Sosyal Bilgiler Dersi Öğretim Programı ve sosyal bilgiler ders kitaplarında tüketim kültürü ve reklamcılığın incelenmesi amaçlanmıştır. Tüketim konusu ekonomik ve toplumsal dinamiklerin karmaşık hale geldiği günümüzde insanların hayatına yön vermektedir. Bu nedenle temel eğitimden itibaren tüketim konusunda öğrencilerin bilinçlendirilmeleri önem arz etmektedir. Çalışmanın veri kaynakları Sosyal Bilgiler Dersi Öğretim Programı (2018) ile güncel sosyal bilgiler ders kitaplarıdır. Analitik araştırma deseninin benimsendiği çalışmada öncelikle tüketim konusu farklı boyutlarıyla ele alınmış, ardından konunun program ve kitaplardaki işlenişi her iki araştırmacı tarafından incelenmiştir. Veriler betimsel analiz yolu ile çözümlenerek yorumlanmıştır. Bulgular sunulurken sıklıkla kitaplardan örneklere yer verilmiş, görseller sunulmuştur. Çalışma sonunda elde edilen bulgulara göre tüketim konusunun daha çok bilinçli tüketim çerçevesinde ele alındığı, tüketim kültürü ve toplumu, tüketim ile reklam ilişkisi konularına yeterince değinilmediği tespit edilmiştir. Bu kapsamda toplumların nasıl tüketim toplumuna dönüştüğü, reklamlar ile insanların nasıl tüketim ortamlarına sürüklendiği hususlarının temel eğitimden itibaren sosyal bilgiler ders kitaplarında örnek olaylarla ve bilimsel çalışma örnekleriyle işlenmesi önerilmiştir. Bu öneriyle öğrencilere tüketimin yegâne amaç olarak sunulması ve benimsetilmesine karşı bir farkındalık oluşturulması gereği ortaya konulmuştur
Gelatine-Based Biopolymer Film Produced from Ozone-Treated Film-Forming Solutions Containing Whey Protein Concentrate: Effects on Physical, Mechanical, and Thermal Characteristics
No full textThis study aimed to determine the effects of the ozone treatment of film-forming solutions (FFSs) containing whey protein concentrate (WPC) and gelatine on biopolymer films' physical, mechanical, and thermal properties. Film samples were produced from a FFS that was ozone-treated at 0 (control), 5, 10, and 30 min. Ozone treatment caused an increase in the pH values of the FFS, whereas the zeta potential remained negative. The films became lighter in colour, slightly greenish, and more opaque with longer ozonation times. The control sample showed the highest thermogravimetric weight loss (92.15%). The weight loss of the samples decreased with increasing ozone treatment time. The application of ozone treatment on the FFS enhanced the films' mechanical properties. Increased ozone treatment time improved the film samples' tensile strength, elongation at break, and toughness values. In conclusion, the results of this study demonstrate that the ozone treatment of FFS containing whey protein concentrate and gelatine can significantly enhance the physical, mechanical, and thermal properties of biopolymer films. These results highlight the potential of ozone treatment as a viable method for improving the performance and quality of biopolymer films used in food packaging, offering promising advantages for sustainable and environmentally friendly packaging solutions