https://hdl.handle.net/20.500.12573/1338 2026-05-08T13:35:55Z 2026-05-08T13:35:55Z Bayram, Umit Ozer, Cigdem Yilmaz, Erkan https://hdl.handle.net/20.500.12573/2500 2025-04-15T08:18:11Z 2025-01-01T00:00:00Z

Comparison of Photocatalytic and Adsorption Properties of ZnS@ZnO, CdS@ZnO, and PbS@ZnO Nanocomposites to Select the Best Material for the Bifunctional Removal of Methylene Blue Bayram, Umit; Ozer, Cigdem; Yilmaz, Erkan In this study, photocatalytic- and adsorption-based removal processes were conducted, which are frequently preferred in wastewater treatment due to their ease of control and high removal efficiency. An innovative method aimed at wastewater treatment was developed by combining the advantages of these two distinct approaches within the same material. The study synthesized ZnO, ZnS, CdS, PbS, and their composite structures (ZnS@ZnO, CdS@ZnO, and PbS@ZnO) using a hydrothermal synthesis method. Characterization of the samples was performed through field emission-scanning electron microscopy (FE-SEM), FE-SEM-energy dispersive X-ray (FE-SEM-EDX), X-ray diffraction (XRD), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR) measurement. Additionally, the optical properties of all samples (absorption spectra and band gap) were investigated by using absorbance measurements obtained from ultraviolet (UV)-visible absorption spectroscopy. Although ZnO nanoparticles are among the materials with high photocatalytic properties (exhibiting a photodegradation efficiency of 95.8% in a short duration of 90 min), their adsorption properties are low. Therefore, with the aim of enhancing both the low adsorption values and the photocatalytic properties of pure metal sulfides (ZnS, CdS, PbS), nanocomposites ZnS@ZnO, CdS@ZnO, and PbS@ZnO with different morphologies were synthesized, and their photocatalytic and adsorption-based removal performances on methylene blue (MB) dye were investigated. FE-SEM images indicated that ZnS nanoparticles exhibit a spherical morphology, CdS nanoparticles have a flower-like morphology, and PbS nanoparticles display a dendritic-like structure. The results obtained from experimental studies demonstrated that the highest efficiency in both photocatalytic- and adsorption-based removal was achieved with the ZnS@ZnO nanocomposite. The degradation rates of MB were found to be 95.3, 90.5, and 89.4% for the heterojunction composites ZnS@ZnO, CdS@ZnO, and PbS@ZnO, respectively, over a time range of 0-480 min. The optimal amount of photocatalyst that could effectively degrade MB was determined to be 100 mg, and the reusability studies revealed that the ability of the ZnS@ZnO semiconductor heterojunction photocatalyst to decompose MB into simpler molecules was limited after the fourth cycle. The adsorption-based removal rates were 96.0, 30.5, and 19.4% for the heterojunction composites ZnS@ZnO, CdS@ZnO, and PbS@ZnO, respectively. Finally, parameters influencing the adsorption-based removal of MB, such as pH, mass, and contact time, were examined, indicating that the adsorption capacity of ZnS@ZnO remained unchanged after reaching a value of 40 mgg-1.

2025-01-01T00:00:00Z Gül, Abdullah https://hdl.handle.net/20.500.12573/2456 2025-03-27T09:21:23Z 2007-01-01T00:00:00Z

YENİ YÜZYILDA TÜRK DIŞ POLİTİKASININ UFUKLARI Gül, Abdullah Türkiye, uluslararası sistem içinde herhangi bir ülke değildir. Tek bir coğrafi bölgeyle tanımlanamayan, kıtaların ve havzaların kesişme noktasını oluşturan jeostratejik konumumuz, Osmanlı mirasımız, Doğu'yla Batı'yı meczeden sosyo-kültürel yapımız ve transatlantik ittifak içindeki özel konumumuz nedeniyle, ulusal çıkarlarımız çok farklı coğrafyalara ve alanlara yayılmış durumdadır. Türkiye'nin bölgesine ve uluslararası sisteme dar kalıplar tanımlanmış güvenlik çıkarları açısından bakan değil, çıkarlarını daha geniş bir çerçevede, uluslararası ve bölgesel işbirliği çerçevesinde tanımlayan bir ülke olarak 21. yüzyıla damgasını vurmasını hedefliyoruz. Statükocu, tepkisel, ve agresif değil, uzlaşma kültürüne açık ve çevresinde olumlu değişiklikleri teşvik eden bir politikayla çıkarlarımızı daha iyi savunabileceğimizi düşünüyoruz. Artık ''çevremiz hasımlarla çevrili'' varsayımına dayanan çatışma psikolojisinden çıkarak, ''çevremizle işbirliği ve diyalog ortamının kurucu aktörü'' rolünü benimsemek zorundayız. Büyük ülke ideali, ancak böyle bir özgüvenle gerçekleştirilebilir.; We must act with a refreshed visıon- a visian in which good governance, transparency and accountability will reign, the fundamental rights and freedoms as well as gender equality are upheld, and there would be no place for blunting rhetoric and slogans. In short, we should first put our house ın order. Rational thinking should be our dividing force, as we our strength from our spiritual values. Creating a synergy from these values inherent in our being will be our test in as well as out contribution to our modern age.

2007-01-01T00:00:00Z Suklun, Harika Bengu, Elif https://hdl.handle.net/20.500.12573/2454 2025-03-27T07:36:06Z 2024-01-01T00:00:00Z

Raising Awareness of Sustainable Development Goals in Higher Education Institutions Suklun, Harika; Bengu, Elif Higher education institutions play a crucial role in advancing sustainable development goals. They bear the responsibility of informing and encouraging all stakeholders, including faculty members, students, and industry partners, to collaborate towards achieving these goals. While many universities are integrating Sustainable Development Goals into their operations and educational programs, there is an increasing need to establish collaborative platforms with private sectors and nongovernmental organizations to further champion this agenda. Educating the future workforce is a key responsibility of these institutions, and they should actively raise students' awareness of these goals, enabling them to develop competencies related to sustainability. This study aims to explore how higher education institutions can effectively raise awareness of sustainable development goals. In addition, the research contributes to the literature by presenting a curriculum designed in a Turkish higher education institution to foster awareness of sustainable development goals. The findings hold the potential to significantly enrich existing literature on awarenessraising practices and the promotion of sustainability strategies, extending beyond higher education institutions to organizations at large.

2024-01-01T00:00:00Z Gül, Abdullah https://hdl.handle.net/20.500.12573/2451 2025-03-27T06:53:28Z 2014-01-01T00:00:00Z

Cumhurbaşkanı Abdullah Gül Demokrasi ve Hukuk Yolunda Meclis Konuşmaları Gül, Abdullah

2014-01-01T00:00:00Z