Human-used antibiotics are eliminated from the body with little or no transformation at all. Traces of eliminated antibiotics enter the receiving environment directly since they cannot be treated in prevalent wastewater treatment facilities. Thus, wastewaters containing traces of antibiotics have to be treated accordingly. Lincomycin is subsequently isolated from Streptomyces lincolnensis. Lincomycin and its derivatives are antibiotics exhibiting biological activity against Gram-positive bacteria, and are natural antibiotics in the environment as pollutants. This study aims to predict the degradation mechanism of lincomycin molecule in the gaseous phase and aqueous media. Probable reaction path of lincomycin molecule with OH radicals was analyzed. Optimized geometry was calculated via Gauss View 5. Subsequently, the lowest energy status was determined through geometric optimization via Gaussian 09 program. Aiming to determine the intermediates in photocatalytic degradation mechanism of lincomycin, geometric optimization of the molecule was realized through DFT method. Activation energy for the probable reaction path was calculated, and their most stable state from the thermodynamic perspective determined for the gaseous phase and aqueous media. Impact of water solvent was investigated using the conductor-like screening solvation model (COSMO). The predicted mechanism was confirmed by comparison with experimental results on simple structures reported in literature.

Edirne il merkezindeki özel bir okulda L3 (Almanca) dersi gören 4., 5. ve 6. sınıf öğrencilerinin (n=111) öğrenme stillerini belirlemektir. Öncelikle L3 öğrenen öğrencilerin L1 (Türkçe), L2 (İngilizce) öğrenme stilleri belirlenmeye çalışılmıştır. Araştırmada, öğrenme stili kavramı L1, L2 ve L3'de nedir? sorusunun yanıtı aranmıştır. Bu araştırmada nitel araştırma yöntemlerinden durum çalışması deseninden yararlanılmıştır. Öğrencilere yönelik çalışmada Aşkar ve Akkoyunlu (1993) tarafından Türkçeye uyarlanan "Kolb Öğrenme Stilleri Ölçeği" kullanılmıştır. Öğrencilerle ayrıca bireysel ve odak grup görüşmeleri yapılıp, öğrenci ürünleri öğrenme stilleri açısından incelenmiştir. Okuldaki, bir Türkçe, bir İngilizce ve bir Almanca öğretmeniyle bireysel görüşmeler de yapılmıştır. Ölçekten elde edilen veriler L1, L2 ve L3'ün birbirlerine olan etki alanları açısından nitel ve nicel olarak değerlendirilmiştir. Araştırmada öğrencilerin L1, L2 ve L3 derslerinde benzer öğrenme stili özellikleri gösterdikleri sonucuna ulaşılmıştır.

The presence of organophosphorus compounds (OPs) in the environmental counterparts has been an important problem because of their toxicity. In this study, the photocatalytic degradation reactions of the three OPs with hydroxyl radical were investigated by both experimental and quantum chemical methods. Photocatalytic degradation kinetics of organophosphorus compounds were investigated under UV-A irradiation using TiO2 as the photocatalyst. The effects of the initial concentrations on the degradation rate have been examined. There was an observable loss of OPs in the presence of TiO2 photocatalyst under UV-A at 0.2 g TiO2 per 100 mL. The quantum chemical calculations have been carried out by the Density Functional Theory (DFT) at B3LYP/6-31g(d) level. Reaction pathways were modeled to find the most probable mechanism for OPs with the OH radical and to determine the primary intermediates. The rate constants of the eight reaction paths were calculated by the Transition State Theory. CPCM (Conductor-like Polarizable Continuum Model) was used as the solvation model with the intention of understanding the water effect. Theoretical results were in agreement with experimental ones.

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