Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/munzur/6101
  Obtaining Natural Dye from Oak Tree and Examination of Dyeing Properties According to Different Methods

  Fırat, Tülay

  This study investigates the dyeing performance of a natural dye extracted from the branches and leaves of the oak tree (soredar) on muslin fabric. The plant materials were soaked in water for 24 h and subsequently boiled to obtain the dye extract. Dyeing experiments were conducted using conventional dyeing methods with and without mordanting. Copper sulphate, iron sulphate, and potassium dichromate were used as mordants to evaluate their influence on the dyeing behavior of the fabric. The color properties of the dyed samples were determined using spectrophotometric measurements based on the CIELab color system, and color strength (K/S) values were calculated using the Kubelka–Munk equation. In addition, the durability of the dyed fabrics was assessed through washing, rubbing, and light fastness tests according to relevant ISO standards. The results revealed that the type of mordant significantly affected both color strength and fastness performance. Among the tested mordants, copper sulphate produced the highest color strength, while iron sulphate also improved dye uptake compared with the non-mordanted sample. Overall, the findings demonstrate that oak-derived natural dye can be effectively applied to muslin fabric and that mordanting plays a crucial role in enhancing the color depth and durability of natural dyeing processes.

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• MakaleAçık Erişim2024/r/munzur/5725
  Comparison of Characteristics and Antimicrobial Activity of Synthesized Zinc Oxide And Magnetite Iron Oxide Nanoparticles Using Four Different Plant Extracts

  Aytar, Mehmet; Aydogdu, Burcu; Unal, Ilkay

  The aim of this study was to synthesize Zinc oxide (ZnO) and magnetite ıron oxide (Fe3O4) nanoparticles utilizing a precipitation method, employing plant extracts from Ocimum basilica(1), Cinnamomum zeylanicum(2), Lactarius salmonicolor(3) and Paeonia kesrouanensis(4) as reduction and stabilizing agents. Additionally, the antimicrobial activity of these nanoparticles against both gram-positive (S. aureus, ATCC 25923) and gram-negative (E. coli, ATCC 25922; P. aeroginosa, PAO1), bacteria as well as fungus (C. albicans 90028) was evaluated. The nanoparticles (NPs) were characterised by various analyses, including TEM, SEM, XRD, FTIR, DSL, and zeta potential. Based on the TEM image, the ZnONPs exhibited a cluster of flower-like structures, whereas the Fe3O4NPs displayed a spherical shape with a varying size distribution. The zeta potential values for ZnO NPs ranged from -5.35 to -16.9, while for Fe3O4NPs ranged from -7.43 to -20.7. All ZnO nanoparticles exhibited antimicrobial activity exclusively against the S. aureus strain, whereas Fe3O4NPs did not demonstrate any antibacterial effect.

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• MakaleAçık Erişim2023/r/munzur/5790
  Reclaim of Wrecked Bi-Te Based Materials In Peltier Modules In Thermopower Properties By Mechanical Milling

  Yüzüak, Ercüment; Cetin, Mehmet; Yüzüak, Gizem Durak

  We thoroughly evaluated the effects of various treatments on the structural and electrical properties of the two as-cast materials, “Sb-doping Bi-Te (p-type)” and “Se-doping Bi-Te (n-type)” which are frequently present in abandoned Peltier modules. To investigate the thermoelectric properties of Bi2Te3-based materials, waste alloys characterized by electrical conductivity using the hot-end method. Alloys were purified by performing arc melting on a water-cooled copper crucible in a vacuum of at least 10-3 mbar, with five times melting sessions to assure homogeneity. A single and long milling period of 144 hours is applied. After the compressing operation, the resulting discs with nanostructures were annealed for an hour at 600 K under vacuum conditions. The discs' structural properties were characterized using X-ray diffraction (XRD) and their surfaces and stoichiometries were determined using scanning electron microscopy with an energy dispersive feature. The Seebeck coefficient of the nanoparticle formed n-type Bi-Te based sample is -35.3 μV.K-1 and p-type Bi-Te based sample is 100 μV.K-1 (15% of mean error margin). It was found that a notable improvement was attained in comparison to the initial state with the addition of nanoparticles.

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• MakaleYalnız künye2022/r/munzur/6556
  Blending Effect of Maleic Anhydride-Styrene-Methyl Methacrylate Terpolymer on Polyvinylchloride (Pvc)/Polystyrene (Ps) Mixtures

  Yilmaz, Ersen

  The blending effect of poly maleic anhydride-styrene-methyl methacrylate (MA-St-MMA) terpolymer on nonmiscible PVC and Polystyrene was studied depending on their thermomechanical properties. Depending on the amount of the synthesized and used compatibilizer the tensile strength, modulus, and thermomechanical properties of the blends are enhanced. The unmodified and blends with small amounts of compatibilizer exhibit two-step degradation whereas those containing 6, 8 and 10 percent compatibilizer showed a single glass transition (Tg). All the results reveal that PS/PVC mixtures modified with MA-St-MMA have superior mechanical properties and phase adhesions than mixtures without terpolymer.

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• MakaleAçık Erişim2022/r/munzur/6537
  Green Synthesis of Gold Nanoparticles Using Aqueous Extract of Asphodelus Aestivus, Coating with Chitosan Biopolymer and Cytotoxicity Studies

  Ates, Mehmet; Yilmaz, Ersen; Erbay, Muhammed

  The green synthesis of gold nanoparticles (Au-NPs) was carried out by pouring the aqueous extract of East Anatolian origin Asphodelus aestivus plant onto aqueous gold metal ions and reducing them via single-step one- pot method. The absorption peak of the synthesized nanoparticles gave a maximum at 575 nm. All the X-ray diffraction peaks at 2θ = 38.25 , 44.46 , 64.64 and 77.20 that index to (111), (200), (220), and (311) planes verify the successful synthesis of Au-NPs. Mostly spherical shape particles showed a homogeneous distribution with size range 20±5 nm are measured using TEM. From the FTIR spectrum, the peaks are seems to be related to phenolic compounds, flavonoids, benzophenones, terpenoids and anthocyanins which assume that they could act as the reducing agents. The plant extraction, one-pot, single-step method used is environmentally safe without the role of synthetic materials which is highly potential in mild and green synthesis applications. The Au-NPs were coated with chitosan biopolymer in aquatic solution medium and verified by SEM. Then, cytotoxic investigations of the biosynthesized Au-NPs were carried out by HUVEC cells. Au-NPs were showed toxic effects on cell culture, even if in a small amount. However, chitosan biopolymer coating increased cell viability.

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• MakaleAçık Erişim2020/r/munzur/6726
  Energy-momentum puzzle in a bianchi-type ıı universe with 𝒇(𝑻) gravity

  Korunur, Murat

  The energy-momentum localization problem, which was attemted by Einstein himself for thefirst time, has been continued to the present day. Recently, new prescription obtained bymodifying the torsion theory and these results shed light on the solution of the energymomentum localisation problem. Focusing this purpose, we consider a Locally RotationallySymmetric Bianchi Type-II model in the teleparallel framework and calculate the modifiedenergy and momentum density for the general case. We also obtain the energy andmomentum density for some special cases of the modified theory and compare our resultswith previous work in the literature.

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• MakaleAçık Erişim2019/r/munzur/5178
  (90-x)TeO2—xMoO3—10ZnO Cam Sisteminin Gama Işını Zırhlama Özelliklerinin Geant4 Simulasyon Kodu ve WinXCOM Veri Tabanı Kullanılarak Araştırılması

  Askin, Ali; Dal, Murat

  Bu çalışmada 90-x)TeO2—xMoO3—10ZnO cam sisteminin (x=10, 20 and 30 %mol) kütle zayıflatma katsayıları (μm), geçirgenlik oranları (T), ortalama serbest yol (MFP) ve yarı değer (HVL) parametreleri 356 keV, 662 keV, 1173 keV and 1330 keV gama foton enerjilerinde hesaplanmıştır. Zırhlama parametrelerini yüksek saflıkta germanium (HPGe) dedektörünün Geant4 modeli ile gerçekleştirilen Monte Carlo simulasyonları ve WinXCOM veri tabanı kullanılarak hesaplanmıştır. Geant4 modelinin geçerliliği PbO—BaO—B2O3 cam sistemi için deneysel olarak bulunan kütle zayıflatma katsayayıları Geant4 ile elde edilen sonuçlarla karşılaştırılarak sağlanmıştır. Bu çalışmanın sonuçları kimyasal formülünde yüksek oranda TeO2 bulunmasından dolayı %10 mol MoO3 içeren cam sisteminin radyayon zırhlama özelliklerinin %30 mol MoO3 cama göre daha iyi olduğunu göstermiştir.

  AtıfOpenAlex13·TR Dizin2

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