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    Amine-functionalized graphene nanosheet-supported PdAuNi alloy nanoparticles: efficient nanocatalyst for formic acid dehydrogenation
    (Royal Soc Chemistry, 2018) Bulut, Ahmet; Yurderi, Mehmet; Kaya, Murat; Aydemir, Murat; Baysal, Akin; Durap, Feyyaz; Zahmakiran, Mehmet
    Formic acid (HCOOH), a major by-product of biomass processing with high energy density, stability and non-toxicity, has a great potential as a safe and a convenient liquid hydrogen (H-2) storage material for combustion engines and fuel cell applications. However, high-purity hydrogen release from the catalytic decomposition of aqueous formic acid solution at desirable rates under mild conditions stands as a major challenge that needs to be solved for the practical use of formic acid in on-demand hydrogen generation systems. Described herein is a new nanocatalyst system comprised of 3-aminopropyltriethoxysilane-functionalized graphene nanosheet-supported PdAuNi alloy nanoparticles (PdAuNi/f-GNS), which can reproducibly be prepared by following double solvent method combined with liquid-phase chemical reduction, all at room temperature. PdAuNi/f-GNS selectively catalyzes the decomposition of aqueous formic acid through the dehydrogenation pathway (similar to 100% H-2 selectivity), in the absence of any promoting additives (alkali formates, Bronsted bases, Lewis bases, etc.). PdAuNi/f-GNS nanocatalyst provides CO-free H-2 generation with a turnover frequency of 1090 mol H-2 mol metal(-1) h(-1) in the additive-free dehydrogenation of formic acid at almost complete conversion (>= 92%) even at room temperature. The catalytic activity provided by PdAuNi/f-GNS nanocatalyst is higher than those obtained with the heterogeneous catalysts reported to date for the additive-free dehydrogenation of formic acid. Moreover, PdAuNi/f-GNS nanoparticles show high durability against sintering, clumping and leaching throughout the catalytic runs, so that the PdAuNi/f-GNS nanocatalyst retains almost its inherent catalytic activity and selectivity at the end of the 10th recycle.
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    A Checklist of Turkish Rotifers
    (Tubitak Scientific & Technological Research Council Turkey, 2012) Ustaoglu, Mustafa Rusen; Altindag, Ahmet; Kaya, Murat; Akbulut, Nuray; Bozkurt, Ahmet; Mis, Didem Ozdemir; Atasagun, Sibel
    In a book chapter containing the first checklist and distribution of Turkish rotifers, published in 1999, were listed 167 taxa. The second checklist, published in 2004, reported 229 rotifer taxa in Turkey. During the 7 years since this checklist process, many studies have been carried out and we have prepared a new checklist of Turkish rotifers in the present study. In all, 341 rotifer taxa have been recorded to date.
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    Cobalt nanoparticles supported on alumina nanofibers (Co/Al2O3): Cost effective catalytic system for the hydrolysis of methylamine borane
    (Pergamon-Elsevier Science Ltd, 2019) Baguc, Ismail Burak; Yurderi, Mehmet; Bulut, Ahmet; Celebi, Metin; Kanberoglu, Gulsah Saydan; Zahmakiran, Mehmet; Kaya, Murat
    Amongst different amine-borane derivatives, methylamine-borane (CH3NH2BH3) seems to be one of the capable aspirants in the storing of hydrogen attributable to its high hydrogen capacity, stability and aptitude to generate hydrogen through its catalytic hydrolysis reaction under ambient conditions. In this research paper, we report that cobalt nano-particles supported on alumina nanofibers (Co/Al2O3) are acting as active nanocatalyst for catalytic hydrolysis of methylamine-borane. Co/Al2O3 nanocatalyst was fabricated by double-solvent method followed with wet-chemical reduction, and was characterized by utilizing various spectroscopic methods and imaging techniques. The results gathered from these analyses showed that the formation Al2O3 nanofibers supported cobalt(0) nanoparticles with a mean diameter of 3.9 +/- 1.2 nm. The catalytic feat of these cobalt nanoparticles was scrutinized in the catalytic hydrolysis of methylamine-borane by considering their activity and durability performances. They achieve releasing of 3.0 equivalent of H-2 via methylamine-borane hydrolysis at room temperature (initial TOF = 297 mol H-2/mol metal x h). Along with activity the catalytic durability of Co/Al2O3 was also studied by carrying out recyclability tests and it was found that these supported cobalt nanoparticles have good durability during the course of the catalytic recycles so that Co/Al2O3 preserves almost its innate activity at 5th catalytic recycle. The studies presented here also contains kinetic investigation of Co/Al2O3 catalyzed methylamine borane hydrolysis depending on the temperature, cobalt and methylamine borane concentrations, which were used to define rate expression and the activation energy of the catalytic reaction. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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    Evaluation of Yields and Quality of Saplings Obtained by Grafting Combinations of Different American Grapevine Rootstocks and Kalecik Karasi Grape Variety
    (2024) Karataş, Hüseyin; Kaya, Murat
    Cultivation on American grapevine rootstocks, which have been found to be an effective solution against phylloxera pest, which is the biggest threat to vineyard areas, has brought along the necessity of examining the affinity between rootstock and scion. In this regard, to increase the amount of current vineyard production by adding a new research to the studies examining the affinity situation in the literature, scions belonging to Kalecik Karası grape variety were grafted on 10 different rootstocks (41B, 5BB, 1103P, SO4, 99R, 1616C, 1613C, 5C, Ramsey ve Harmoney) by omega bench grafting method, and sapling yield and quality characteristics were examined in greenhouse conditions for two years in duplicate. After the measurements carried out in both years, it was determined that the average degree of callus formation of the combinations formed trough different rootstocks was 3.45, the length of the saplings was 10.90 cm, the number of leaves was 5.71 and the total sapling yield was 78%.
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    Evaluation of Yields and Quality of Saplings Obtained by Grafting Combinations of Different American Grapevine Rootstocks and Kalecik Karasi Grape Variety
    (Mevlüt AKÇURA, 2024) Karataş, Hüseyin; Kaya, Murat
    Cultivation on American grapevine rootstocks, which have been found to be an effective solution against phylloxera pest, which is the biggest threat to vineyard areas, has brought along the necessity of examining the affinity between rootstock and scion. In this regard, to increase the amount of current vineyard production by adding a new research to the studies examining the affinity situation in the literature, scions belonging to Kalecik Karası grape variety were grafted on 10 different rootstocks (41B, 5BB, 1103P, SO4, 99R, 1616C, 1613C, 5C, Ramsey ve Harmoney) by omega bench grafting method, and sapling yield and quality characteristics were examined in greenhouse conditions for two years in duplicate. After the measurements carried out in both years, it was determined that the average degree of callus formation of the combinations formed trough different rootstocks was 3.45, the length of the saplings was 10.90 cm, the number of leaves was 5.71 and the total sapling yield was 78%.
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    FARKLI AMERİKAN ASMA ANAÇLARI ÜZERİNE AŞILANAN ŞİRE (MAZRUMİ) ÜZÜM ÇEŞİDİNDE TÜPLÜ FİDAN RANDIMANI VE KALİTE ÖZELLİKLERİNİN İNCELENMESİ
    (2023) Karataş, Hüseyin; Kaya, Murat
    Bu çalışma, 2021-2022 yılları içerisinde Dicle Üniversitesi Bahçe Bitkileri bölümüne ait bağcılık uygulama ve sera alanında yürütülmüştür. Çalışmanın bitkisel materyalini, bölge halkı tarafından sevilerek tüketilen Şire üzüm çeşidine ait kalemler ve farklı özellikteki yedi Amerikan asma anacı (5BB, 110R, 1103P, 41B, 1613C, 420A ve 99R) oluşturmuş olup Şire üzüm çeşidinin farklı Amerikan asma anaçları üzerindeki afinite durumunun incelenmesi amaçlanmıştır. Dinlenme döneminde alınan çelikler masa başı omega aşı yöntemiyle aşılanıp kaynaştırma odasında dört hafta bekletildikten sonra kaynaşmış çelikler köklendirilmek üzere seraya aktarılmıştır. Kaynaşmış çeliklerde kaynaştırma odası randımanı, kallus skalası (0-4) ve kallus oluşum yüzdesi; aşılı çeliklerin seraya gelişimlerini sağlamak için bırakıldıktan iki ay sonra aşılı fidanlarda ise, fidan kalite özellikleri, I., II. ve III. boy fidan randımanı belirlenmiştir. Elde edilen veriler varyans analizine tabi tutulup ortalamalar asgari önem fark (AÖF) esas alınarak sınıflandırılmıştır. Çalışma sonunda, kaynaştırma odası randımanı %92-100 arasında değiştiği saptanmıştır. Öte yandan, sürgün ve kök gelişim aksamı başlığı altında incelenen tüm parametrelerde, anaç çapı parametresi hariç, %5 önem seviyesinde istatiksel farklar görülmüştür. En yüksek toplam fidan randımanı 1103P × Şire kombinasyonunda %94.62 ile saptanırken en düşük randıman 41B × Şire kombinasyonunda %56.99 olarak elde edilmiştir.
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    Neuroprotective Effects of Olanzapine in N-Methyl-D-Aspartate-Induced Retinal Injury
    (Mary Ann Liebert, Inc, 2013) Onder, Halil Ibrahim; Aktan, Gulderen; Yuksel, Harun; Avcioglu, Sedat; Yildirim, Umran; Kaya, Murat; Tunc, Murat
    Purpose: The aim of this study was to investigate the neuroprotective effect of olanzapine (OLA), an atypical antipsychotic drug, on N-methyl-D-aspartate (NMDA)-induced retinal injury. Methods: Retinal neuronal ischemia was induced by NMDA in Wistar rats. OLA was administered intraperitoneally in 2 different dosages: 2 and 12 mg/kg. At the end of 2 weeks of OLA treatment, 1 eye of each animal was enucleated for histopathologic examination. We also measured malondialdehyde (MDA) levels in retinal homogenates as a marker of ischemic injury. Results: The retinal ganglion cell (RGC) count was significantly higher in cases where we used OLA 2 mg/kg or OLA 12 mg/kg compared to the control group (P = 0.0032 and P = 0.0005, respectively). We also found that MDA was significantly reduced by OLA 2mg/kg or OLA 12 mg/kg compared to the control group (P = 0.0001 and P = 0.0001, respectively). There was no statistically significant difference between OLA 2 mg/kg or OLA 12mg/kg groups in terms of RGC count and MDA levels (P > 0.05 for all). Conclusion: Our data showed that OLA preserved RGCs from NMDA-induced retinal injury; thus, it may have potential neuroprotective effects.
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    Phosalone Toxicity on Liver and Pancreas: Role of Vitamins E and C
    (Asian Journal Of Chemistry, 2013) Demirin, Hilmi; Gokalp, Osman; Kaya, Ertugrul; Buyukvanli, Bora; Cesur, Gokhan; Ozkan, Aybars; Kaya, Murat
    Phosalone (6-chloro-3-[diethoxyphosphinothioylsulfanylmethyl]-1,3-benzoxazol-2-one) is one of the most commonly used organophosphorus pesticides in the peat control of crops. Subchronic phosalone exposure was evaluated for its effects on the serum activities of some enzymes concerning hepatic and pancreatic damage including aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamyltransferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), cholinesterase (ChE); and finally protective effects of combination of vitamins E and C in 24 wistar-albino rats. Experimental groups were as follows: control group (n = 8); a group treated with 120 mg/kg body weight phosalone (P group, n = 8); and a group treated with 120 mg/kg body weight phosalone + vitamin E + vitamin C (P+V group, n = 8). The P and P+V groups were treated orally with phosalone on 5 days a week for 4 weeks. The serum activities of the above mentioned enzymes were analyzed. In the samples phosalone significantly increased the activities of ALT, LDH and decreased ChE (p < 0.05). However no significant change was detected for the remainder enzymes (p > 0.05). In the P+V group, ALT and LDH activities were significantly increased and ChE decreased (p < 0.05). It is concluded that subchronic phosalone causes rat liver damage to an extent, which is somewhat reflected on the liver enzymes. Furthermore, a combination of vitamins E and C can reduce the toxic effects of phosalone on liver tissue of rats.
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    Preparation and characterization of ni-nitrilotriacetic acid bearing Poly(Methacrylic acid) coated superparamagnetic magnetite nanoparticles
    (Amer Scientific Publishers, 2008) Tural, Bilsen; Kaya, Murat; Oezkan, Necati; Volkan, Muervet
    Stable superparamagnetic magnetite (Fe3O4) nanoparticles were synthesized via co-precipitation in the presence of poly(methacrylic acid) (PMAA) in aqueous solution. The polymer coated Fe3O4 nanoparticles were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis, and vibrating sample magnetometry (VSM) techniques. These measurements reveal the presence of magnetite nanoparticles with a size of approximately 8 nm inside the PMAA matrix. The magnetization value of these superparamagnetic nanoparticles at room temperarure and 7 T was measured as about 40 emu/g. PMAA-coated Fe3O4 nanoparticles were further assembled with Ni-chelate through a reaction between a primary amine-bearing NTA (nitrilotriacetic acid) ligand and carboxy-functional groups of PMAA. NTA-PMAA-coated magnetite nanoparticles were then loaded with nickel ions and characterized using FTIR. The average amount of binded Ni on the surface of the NTA-modified PMAA coated Fe3O4 was calculated as 1.65 +/- 0.3 x 10(-6) mol nickel(II) ions per g of the magnetic particles from the inductively coupled plasma optical emission spectroscopy (ICP-OES) measurements.