Browsing by Subject "Mineraloji"
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Item Adsorption Studies of Radionuclides by Turkish Minerals: A Review(2022) Ümran Hiçsönmez; Süleyman İnanHazardous radionuclides are produced during normal operation of nuclear power plants and research facilities. They can also spread to the environment due to fallout from nuclear accidents and nuclear weapon tests. The removal of hazardous radionuclides and the safe management of radioactive waste are of vital necessity. Natural minerals have been widely used for the removal of heavy metals and radionuclides because of their low cost, high capacity and radiation resistance properties. Turkey has an abundant natural mineral deposits. These deposits include clinoptilolite, bentonite, montmorillonite, kaolinite, vermiculite, illite, red clay, sepiolite, diatomite, perlite and volcanic tuff. Within the scope of this review, Turkish minerals were classified as three main groups as; zeolites, clay minerals and other minerals. The review consists of sections on the general properties of natural minerals such as zeolites and clays, the characteristics of Turkish minerals, and the adsorption performance of these minerals against some radionuclide ions (Sr, Cs, U, Th and Po).Item Cyclamen hederifolium Aiton ve C. persicum Mill. (Primulaceae) Türlerinin Morfolojik, Anatomik, Palinolojik ve Toprak Özellikleri Bakımından İncelenmesi(2023) yeliz uçkun; Kemal YıldızBu çalışmada, İzmir ve çevresinde yetişen Cyclamen hederifolium ve C. persicum türleri morfolojik, anatomik, palinolojik ve türlerin yetiştiği toprak özellikleri incelenmiştir. İncelenen türlerin betimleri genişletilmiştir. Mikromorfolojik incelemeler, stereo ve taramalı elektron mikroskobu (SEM) ile yapılmıştır. Tohum şekillerinin C. hederifolium türünün dikdörtgensi-yamuk, C. persicum türünün ise, elips şeklinde olduğu tespit edilmiştir. Türlere ait gövde ve yaprak enine kesitleri alınmış ve anatomik özellikleri ışık mikroskobunda incelenmiştir. Polen özellikleri, ışık mikroskobu ve taramalı elekron mikroskobu (SEM) incelenmiştir. Palinolojik incelemelerle, polen şekillerinin her iki türde de sferoidalden oblata kadar, izopolar, yüzey ornemantasyonlarının psilat, skabrat, apertür durumlarının ise, trikolpat olduğu belirlenmiştir. Bu nedenle, incelediğimiz türlerin ayrımınında polen yapılarının kullanılamayacağı sonucuna varılmıştır. Toprak özelliklerini belirlemek için, türlerin yetişme alanından alınan toprak örneklerinin analizleri yapılarak, element istekleri belirlenmiştir. Toprak özellikleri bakımdan, türlerin pH değerleri hafif alkali, tuzsuz, killi tınlı, C. hederifolium türünün orta ve çok kireçli, organik madde bakımından fakir, orta, yüksek, C. persicum türünün ise az kireçli, organik madde bakımından yüksek yüzdeli toprakları tercih ettiği tespit edilmiştir. Çalışmanın sonunda, türlerin morfolojik bakımından birbirinden kolaylıkla ayırt edilebildiği ve yetişme alanlarının genellikle benzer olduğu belirlenmiştir.Item Türkiye Suyosunları (Algler) Listesi'ne Eklentiler(2023) ERGÜN TASKIN; Mehmet Tahir Alp; Murat ÇAKIR; Özgür ÖZBAYBu makalede, Türkiye Suyosunları Listesinde bulunmayan tür ve türaltı seviyede toplam 436 takson [328 Bacillariophyta (Diyatome Bölümü), 32 Cyanobacteria (Mavi-Yeşilbakteriler Bölümü), 1 Dinophyta (Ateşrengisuyosunları Bölümü), 2 Euglenophyta (Öglena Bölümü), 5 Ochrophyta (Sarı Kahverengi Alg Bölümü), 29 Rhodophyta (Kırmızı Algler), 12 Chlorophyta (Yeşil Alg Bölümü), 27 Charophyta (Suşamdanı Bölümü)] ve bu taksonların Türkçe Bilimsel adları verilmiştir.Item Evaluation of the Structural, Near-Infrared Luminescence, and Radioluminescence Properties of Nd3+ Activated TTB-Lead Metatantalate Phosphors(2023) İlker Çetin KESKİN; mustafa ilhanThe study reports the structural and spectroscopic properties of Nd3+ doped lead metatantalate phosphor series fabricated by conventional solid state method. XRD results of the PbTa2O6 phase confirm the tungsten bronze symmetry and single-phase structure between 0.5 and 10 mol% Nd3+ concentrations. The lead decrease in the structure can be associated with maintaining the charge balance and single phase due to evaporation during sintering. In SEM micrographs, the grains exhibited shapeless morphology, and the grain sizes varied from 0.5 to 7 m. In EDS results, the increase of Ta/Pb ratio in grain surfaces indicated some lead evaporation, as reported in previous studies. The absorption spectrum of PbTa2O6 host peaked around 275-280 nm, and the band gap was found to be 3.7±0.2 eV. The absorptions of Nd3+ doped phophors shifted the high wavelenght or the low band gap, where the band gaps were found between 3.1±0.2 and 3.3±0.2 eV. The PL emissions of the phosphors in near-inrared region were observed with the transitions of 4F3/2→4I9/2 (at 875 nm) and 4F3/2→4I11/2 (at 1060 nm) of Nd3+. The RL emissions or X-ray excited luminescence were monitored with the transitions of 4F3/2→4I9/2 (at 875 nm), 4F3/2→4I11/2 (at 1065 nm) in the infrared region, and the transitions of 2F(2)5/2→4F9/2, 2F(2)5/2→2H(2)11/2, 2F(2)5/2→4G5/2, 2F(2)5/2→4G7/2, 2F(2)5/2→4G9/2 in the visible region corresponding to at around 430, 455, 490, 525, and 570 nm, respectively. PL and RL emissions of the phosphors exhibited the decreasing emission intensity over 5 mol% due to the concentration quenching which may be associated with cross-relaxing mechanism. In the PL and RL spectral profiles, the similarity of splitting levels was attributed to the similarity of the local symmetry of the ligand ions surrounding the Nd3+ ion. The CIE coordinates obtained using RL emissions were found close to the blue region due to visible region transitions.Item Amazonite in Pakistan: A Comprehensive Study with XRD, XPS, SEM, and PL Analyses(2023) Eren Cihan Karsu AsalAlthough amazonite minerals from various locations have been studied before rather less attention has been paid to the amazonite mineral from Pakistan. The present work is presented an extensive structural characterization of natural amazonite aliquots (KAlSi3O8) from Tangir Valley, Gilgit-Pakistan. The phase and elemental analysis have been characterized by both X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS), respectively. The surface morphology and particle size have been identified by Scanning Electron Microscopy (SEM). The luminescence properties have been investigated using PhotoLuminescence (PL). In addition, the lifetime of the PL emission measurements has been estimated. Eventually, this microcline has a triclinic phase, mainly composed of (AlO4)-5 ions, SiO2, metal SiO4, Al2O3 and oxygen originating from impurities. The average particle size is around 1–10 µm with a complex structure. The PL spectrum has broad emission and excitation bands (520 nm and 340 mm respectively). The average lifetime of the PL emission is 265,21 µs. For the accuracy of the results all experiments were performed with not only a single aliquot, but with three aliquots, and representative results are presented.Item Dose Determination of Fluvial Sediments in Manisa(2023) mujde durukan gultepe; Arzu EgeQuartz, which is one of the most abundant minerals in nature, can be found in magmatic and metamorphic forms, as well as the usual components of granite and sedimentary formations. Quartz minerals, which are also known as the main component of quartzites, are also known as gangue minerals in many mineralizations. Quartz samples from two different sampling levels, namely the Kaletepe lower and the Kaletepe upper region, used in the study were prepared. Thermoluminescence (TL) glow curves of the samples exposed to radiation with a 90Sr/90Y β source were recorded with a TLD reader. While peaks were obtained at approximately 270 °C from the glow curves of the Kaletepe lower samples irradiated with β source, peaks were obtained at approximately 270 °C and 350 °C from the Kaletepe upper samples. When the annual average dose and age values of the lower and upper Kaletepe samples are examined, it can be said that it was formed in a time period of ~8000 years between two areas with a height difference of 130m.Item Molybdenum–Vanadium Oxide Clusters: Syntheses, Structures and Antibacterial Properties(2024) Hülya Avcı ÖzbekThe design and synthesis of polyoxometalates (POMs), a type of inorganic compounds, are of great interest due to their interesting structural properties as well as their extensive theoretical and practical applications in catalysis, electrical conductivity, magnetism, optics and medicine. Therefore, in this study two molybdovanadates [Cu(phen)2]3[Mo6V2O26]·4H2O and [Cu(bpy)2]3[Mo6V2O26]·4H2O have been prepared by the reaction of the [Mo6V2O26]6- anion with Cu(CH3COO)2 and 1,10-phenanthroline/2,2'-bipyridine in aqueous medium; characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (1H NMR), Inductively coupled plasma mass spectrometry (ICP-MS), Thermogravimetric Analysis (TGA) and elemental analysis. The compounds show antibacterial activity against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus).Item Investigation of the Effect of High-Frequency Induction Sintering on Phase Structure and Microstructure of SiC Reinforced Aluminum Matrix Composites(2024) MUHTEREM KOÇ; Mehmet Sadrettin ZeybekIn this study, SiC-reinforced aluminum matrix composites were powder metallurgically (PM) prepared and sintered using high-frequency induction system (HFIS). The samples with different ratios of SiC (wt.%10, 20 and 40) added to the aluminum matrix were sintered at 660, 800, and 1000 °C. In addition, Al/SiC composites were compared by sintering with the conventional sintering (CS) method under similar sintering conditions. The heating rate for the sintering process using HFIS was 500 °C/min, while the CS method used a heating rate of 10 °C/min. The effect of the temperature and SiC ratio on the density, hardness, phase structure, and microstructure of composites was investigated. The optimum sintering temperature was determined according to the SiC additive amount. When 10%, 20%, and 40% SiC by weight were added to the aluminum matrix in the sintering process with HFIS, the required sintering temperatures were determined as 660, 800, and 1000 °C, respectively. While new phases were not formed as a result of short-term HFIS sintering, a high-temperature Al4C3 phase was detected in CS sintering. HFIS sintered Al/SiC composite samples were obtained in Al and SiC phases with high density and hardness ranging from 43-118 HV. In the high-temperature sintering process with HFIS, the formation of Al4C3 was prevented and its physical and mechanical properties were improved.Item Orange Emitting SrS: Eu2+, Dy3+ Afterglow Phosphor: Structural and Luminescence Properties(2024) Eren Cihan Karsu Asal; Serdar YILDIRIMSrS:Eu is known as an attractive material for imaging, scintillator, or persistent phosphor applications, thanks to its effective photoluminescence (PL) and thermoluminescence (TL) capabilities, but there are still great mysteries of persistent phosphors and attract great interest. Hence, this work investigated the luminescence properties of well-known persistent phosphor based on SrS using various spectroscopic techniques for detailed characterization. Measurements using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to analyze the phase and elements of the phosphor. Belongs to the XRD data the microcrystalline phosphor is cubic, and the diameters ranged from 1 to 100 µm. The morphology of the phosphor was examined by scanning electron microscope (SEM). A time-resolved PL system recorded PL properties, namely the emission and excitation spectra of the phosphor. SrS emits around 626 nm with a broad excitation band peaking around 466 nm. A TLD reader system measured the TL glow curve of the phosphors after UVB radiation. The TL glow curve exhibited a broad peak around 160oC. The dose-response of this peak was obtained up to 600 seconds of exposure to UVB radiation, and it was observed that the dose-response curve exhibits a saturating exponential behavior.