Yazarlar
- Tanyol, Mehtap(22)
- Yildirim, Numan(17)
- Karataş, Mehmet(14)
- Erguven, Gokhan Onder(13)
- Topal, Murat(13)
- Ince, Muharrem(12)
- Yildirim, Nuran Cikcikoglu(10)
- Kismet, Yilmaz(9)
- Öbek, Erdal(8)
- Arslan Topal, E. Işıl(7)
- Etli, Serkan(7)
- Goksu, Ali(7)
- Gul, Muhammet(7)
- Gülmez, Nihan(7)
- Ogedey, Aysenur(7)
- Uysal, Turan(7)
- Yonten, Vahap(7)
- Gürler, Nedim(6)
- Kaya, Sema Kayapinar(6)
- Sabanci, Serdal(6)
- Serdar, Osman(6)
- Yön, Merve Şahin(6)
- Alp, Hevidar(5)
- Aydoğmuş, Ercan(5)
- Benli, Ahmet(5)
- Cemalgil, Selim(5)
- Erdemoğlu, Murat(5)
- Erust, Ceren(5)
- Ince, Olcay Kaplan(5)
- Oguz, Ensar(5)
- Torğut, Gülben(5)
- Yilmaz, Mehmet(5)
- Yucesan, Melih(5)
- Celik, Erkan(4)
- Demir, Veysel(4)
- Dener, Murat(4)
- Doğan, Akar(4)
- Fırat, Tülay(4)
- Pekdemir, Mustafa Ersin(4)
- Tanaydin, Mehmet Kayra(4)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ2The impact of global value chains on climate change
Ateş, Erdem; Şanlısoy, Selim
Climate change can be defined as the increase in average temperatures due to rising greenhouse gas (GHG) emissions, predominantly due to human activities. Carbon emissions have increased at an alarming rate with the emergence of globalization, with its accompanying global value chain, and the consequent increase in global production volume with its polluting sectors. To combat this alarming situation, production with environmentally friendly technologies has emerged recently, and developing countries are embracing more and more costly environmentally friendly production techniques, although they are disadvantaged when it comes to covering the costs. However, it has been observed that they stay behind in this race to adopt environmentally friendly techniques compared to developed countries. The aim of the study, which is a novel contribution to the existing literature, is to examine the relationship between the global value chain and climate change by considering the distinction between developed and developing countries. The study used the data of 156 countries from the years 2000–2018. The results obtained from the generalized method of moments (GMM) show that participation in global value chains has different effects in developed and developing countries regarding carbon emissions. When the level of participation in GVC (global value chain) and FVA (foreign value added) increases, countries’ carbon emissions decrease, and it increases when the DVA (domestic value added) level increases. As a result, in particular, developing countries should green their production methods, and for this purpose, financial support mechanisms should be established.
AtıfScopus8WoS4OpenAlex7
İncele - MakaleYalnız künye2025Scopus SJRQ3Development of alternative carbon fibre powder and rare earth element-based filler for high density polyethylene; [Entwicklung von alternativen Kohlenstofffaserpulvern und Seltene Erden-basierten Füllstoffen für Polyethylen hoher Dichte]
Ayikurt, P.; Kısmet, Y.; Dogan, A.; Höchstötter, K.H.; Fiedler, B.
This study developed alternative fillers to enhance the flowability of high-density polyethylene (HDPE). Lanthanum and cerium oxide with over 90 % purity were used as binder interfacial elements in fillers developed using both carbon fiber powder wastes and powder coating wastes. Polyethylene gel was used to make the fillers thermoplastic and homogenous. A total of six different fillers were developed and melt flow index analyses were performed. As a result of these analyses, it was found that the fluidity of high-density polyethylene improved significantly, especially with fillers containing carbon fiber powder. As a result, high-density polyethylene mixtures containing 10 %, 20 %, 30 %, 40 %, and 50% by weight of carbon fiber powder-based fillers were pressed into molds by a plastic injection molding machine, and samples were produced. According to the mechanical analysis results of these specimens, tensile and flexural strengths decreased slightly depending on the filling ratio, while the impact strengths remained constant. Differential scanning calorimetry analysis was performed to determine the glass transition temperature and melting/crystallization temperatures of the obtained mixtures, while thermogravimetric analysis was performed to determine the mass losses. At the same time, electron microscope analysis of the cross sections of the samples were performed.
- MakaleAçık Erişim2025Scopus SJRQ1Selection of the central composting facility for organic wastes through the Bayesian best worst method and Geographic information system incorporation: The case of Istanbul
Güler, Mustafa; Samastı, Mesut; Yücesan, Melih; Gül, Muhammet; Çelik, Erkan; Ciner, Miraç Nur; Algorabi, Ömer
The rapid increase in municipal solid waste (MSW) generation, driven by population growth and unplanned urbanization, has made the location of organic waste collection and disposal facilities a critical issue for metropolitan cities. Improper waste management practices threaten environmental sustainability, human health, and urban futures. This study applies multicriteria decision-making (MCDM) methods to identify the optimal placement for a central composting facility in Istanbul. A novel MCDM mechanism was developed, building on existing methods and addressing a gap in the literature. While determining the criteria, academic studies on this subject were researched in depth and the criteria used in these studies were brought together to obtain 28 criteria. The study assessed 28 criteria using the Bayesian Best-Worst Method (BWM) to determine their relative importance. These weights were then integrated into a Geographic Information System (GIS) to produce a suitability map, highlighting the most appropriate locations for the facility. Based on this analysis, the Çatalca Karacabey region was identified as the optimal site, ensuring reduced environmental impact and improved efficiency in organic waste management. The study contributes both theoretically and practically to the field, offering a robust framework for sustainable waste facility siting and providing actionable insights for urban governance. The study provides valuable insights for facility siting and urban governance, while highlighting areas for future research.
AtıfScopus5WoS4İncele - MakaleYalnız künye2025Scopus SJRQ1Dunite powder as a green precursor in one-part alkali-activated composites: Effects on mechanical and durability properties
Benli, Ahmet; Bayraktar, Oğuzhan Yavuz; Karataş, Mehmet; Bodur, Burak; Yılmazoğlu, Mehmet Uğur; Kaplan, Gökhan
Natural pozzolans are a sustainable alternative to Portland cement, offering abundant alumina and reactive silica for geopolymer production. Due to their simple extraction methods, they are cost-effective and environmentally friendly. This study explores the utilization of dunite powder (DP) as a sustainable precursor in one-part alkali-activated slag-based composites (AAC), aiming to evaluate its potential to partially replace granulated blast furnace slag (GBFS). The mechanical, fresh, and durability properties of the composites were investigated by varying DP replacement levels (0%, 15%, 30%, and 60%) under an activator dosage of sodium metasilicate, with the mixtures cured at 80 °C for 24 h and subsequently exposed to ambient conditions. The compressive and flexural strengths were evaluated at 7, 28, and 91 days, while the fresh properties (flowability and setting time), durability under sulfate attack, high-temperature resistance, freeze-thaw resistance, dry shrinkage, sorptivity and microstructural characteristics (SEM, XRD, and FT-IR) were also examined. The compressive strength decreased with higher DP content, with the 60% DP mixture showing a 43% strength reduction at 28 days compared to the reference mixture. However, the 30% DP mixture achieved a favorable balance between strength and sustainability, demonstrating a compressive strength decrease of only 11% at 91 days. The mixture containing 15% DP demonstrated the best performance under high-temperature conditions and freeze-thaw cycles. The 60% DP mixture exhibited the highest mass and strength loss when exposed to temperatures above 400 °C and a 15% compressive strength reduction after 120 days of immersion in a 10% MgSO4 solution.
AtıfScopus29OpenAlex22İncele - MakaleAçık Erişim2025Scopus SJRQ3Experimental and Theoretical Study on the Freshwater Productivity of a Single-Slope Solar Still
Tuğan, Volkan; Işık, Erdem; İnallı, Mustafa
Converting saline water into freshwater using renewable energy resources is crucial to address global shortages of freshwater. This study aims to investigate the freshwater productivity of a single-slope solar still (SSS) operating with solar energy, one of the renewable energy sources. The main motivation of this study is to evaluate the experimental, theoretical, and economic performance of the solar still under climate conditions that have not been sufficiently studied before. Experimental analyses were conducted under the climatic conditions of Tunceli, a city located in the Eastern Anatolia Region of Türkiye. In addition, a comprehensive theoretical analysis was carried out using energy equations, and the experimental and theoretical results were compared with each other. Finally, the economic feasibility of the system was evaluated through a cost analysis. The SSS's experimental and theoretical productivity were found to be 1883.9 and 2458.7 g/m2/day, respectively. The experimental thermal efficiency for this still was 15.1%, whereas the theoretical thermal efficiency was 19.7%. It was concluded that the theoretical productivity and efficiency values were close to the experimental values and the difference between them originated from the assumptions of theoretical calculations. The cost of water distilled by the single-slope solar distillation unit was found to be $0.077/kg, and the payback period was found to be 9 months.
AtıfScopus2WoS3OpenAlex2İncele - Kitap BölümüYalnız künye2025Scientific production in waste management and ecological sustainability from a bibliometric approach
Ay, Ilhami; Dal, Murat
This study employs a bibliometric approach to examine the scientific production trends in waste management and ecological sustainability, encompassing publications from 1995 to 2024. The research employs the VOSviewer software to analyse 778 academic articles indexed in the Web of Science database. By identifying key journals, influential authors, major keywords and citation networks, the study elucidates the academic evolution and emerging directions in waste management research. The findings indicate a significant increase in publication activity post-2014, which reflects the growing importance of sustainability issues. The key themes identified include waste management, environmental sustainability, life cycle assessment, and the circular economy. The study underscores the need for interdisciplinary approaches and enhanced global collaboration in advancing sustainable waste management practices. Through its comprehensive analysis, this research provides valuable insights for academia and policymakers to address environmental challenges effectively.
- MakaleAçık Erişim2025Scopus SJRQ1Improvement of mechanical, dynamic mechanical, and thermal properties of almond shell powder reinforced acrylonitrile butadiene styrene composites by addition of cerium oxide
Doğan, Akar; Güneş, Çağdaş
Currently, natural materials are gradually replacing synthetic materials in polymer composites due to factors including cost-effectiveness, sustainability, and the availability of raw materials. This study examined the variations in thermal, mechanical, and dynamic mechanical properties of acrylonitrile butadiene styrene (ABS) thermoplastic composite materials incorporating varying ratios of almond shell powder (ASP) and Cerium Oxide (CeO2). Tensile tests, three-point bending tests, dynamic mechanical analyses, and thermogravimetric analyses were conducted. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses were employed to assess pure ABS and nine distinct composite materials. The tensile strength, elastic modulus, and three-point bending strength of the composite material exhibited increases of 6%, 7%, and 7.5%, respectively, compared to pure ABS, with various ratios of almond shell powder and CeO2 reinforcement. Moreover, composite materials exhibit elevated glass-transition temperatures and storage moduli compared to pure ABS. Microstructure images obtained through SEM and EDS element mapping illustrate the distribution of ASP and CeO2 in ABS, influencing its mechanical and thermal properties. Highlights: Almond shell powder and cerium oxide were used as filler materials in ABS. Mechanical, morphological, and dynamic mechanical properties were investigated. Almond shell powder enhanced the mechanical properties of the ABS composite. Low cerium oxide supplementation improved the mechanical properties.
AtıfScopus4WoS4OpenAlex5İncele - MakaleAçık Erişim2024Evaluation of Novel Plant-Based Milk Produced from Melon Kernel
Aydın, Çağlar Mert
In this study, the possible use of melon kernel (Cucumis melo L.) as a source for production of daily milk alternative was evaluated. For this purpose, the study evaluated proximate composition, physicochemical properties and sensory properties of the milk from Kultik kernel. Overall, proximate composition consists of 88.84% moisture, 1.08 ash, 0.96 protein and 5.50% fat and 3.63% carbohydrate content. Low protein content of the milk limits its usage as an ingredient in the production of fermented dairy products. Physicochemical properties showed that Kultik kernel milk is rich in nutritional value. Rheological behaviour of the milk showed non-Newtonian with pseudoplastic character. Similar flow character to dairy milk enables the milk sample to be produced in existing equipment and processes, allowing large-scale industrial production. In addition, sensory scores of the milk sample were low, thus new formulas including the milk samples should be developed in further studies.
AtıfOpenAlex2TR Dizin1
İncele - MakaleAçık Erişim2024Effect of Synthetic Wastewater on Antioxidant Defence System in Dreissena polymorpha
Serdar, Osman; Erguven, Gokhan Onder; Yildirim, Nuran Cikcikoglu; Korkmaz, Volkan; Erguven, Gozde
The effects of the synthetic wastewater on antioxidant defence system in Dreissena polymorpha was evaluated. For this purpose, SOD, CAT, GPX activities and TBARS and GSH levels in tissues were determined by using commercial kits. The activities of SOD and CAT were in sythtetic group were determined lower than the control group in D. polymorpha during 24 and 96 h (p<0.05). After exposure of the cells of D. polymorpha samples to synthetic wastewater, depletion in GSH levels and subsequent increase in TBARS levels were observed, reflecting their unstable state. According to the data obtained from the study, It can be inferred that the biomarkers being domestic monitored are beneficial and effective in evaluating the biochemical mechanisms of wastewater as early warning indicators.
- MakaleAçık Erişim2024Scopus SJRQ2Usability of Essential Oil Extracted Plant Pulp in Screen Printing in the Context of Sustainability
Ayvaz, Kartal Murat; Teker, Menekse Suzan
Problem statement; The main purpose of the study, "Usability of De-Essential Plant Pulp in Textile Printing in the Context of Sustainability", is to reveal the industrial use of natural dyes in the textile printing sector. During the preliminary evaluation process, it was seen that screen printing as a printing method has significant advantages for the industrial integration of natural dyes. Based on this, as a result of the applications and analyzes carried out with the experimental research method, it has been revealed that the use of natural dyes on an industrial scale will be possible by transferring the natural dye obtained from plant pulp with essential oil removed to the textile surface with the screen printing technique and ensuring sufficient fastness. In this study, it is aimed to present screen printing as an alternative to traditional fabric printing techniques, as well as to make positive contributions to sustainability by using natural dyes obtained from plant pulp. This increases the importance of the study. As a result, it has been observed that natural dyes obtained from plant pulp with essential oils removed can be transferred to the fabric by screen printing technique, and the pre-mordanting process and fixing in salt water increase the washing and rubbing fastness values. Apart from all these, three new emulsion-free printing techniques have been developed, independent of the emulsion printing technique applied as standard in screen printing technique
AtıfOpenAlex1İncele - MakaleAçık Erişim2024Sentetik Atık Takviyeli Poliolefinlerin Mekanik Özelliklerinin GA-LSTM Hibrit Modeli ile Tahmini
Utku, Anıl; Kismet, Yilmaz; Can, Umit
Bu çalışmada, parçacık takviyeli termoplastiklerin enjeksiyon kalıplamasında kullanılan üretim parametrelerinin ürün kalitesi ve üretilen parçanın mekanik özellikleri üzerindeki etkileri optimize edilmiş bir Genetik Algoritma-Uzun Kısa Süreli Bellek (GA-LSTM) hibrit derin öğrenme yöntemi kullanılarak modellenmiştir. Burada termoplastik olarak poliolefinler grubunun en önemli üyesi olan AYPE, YYPE ve PP kullanılırken takviye elemanı olarak ise toz halde sentetik boya atıkları kullanılmıştır. Farklı parametreler kullanılarak enjeksiyon kalıplama yoluyla 819 numune üretilmiş ve her numune üzerinde mekanik çekme, üç nokta eğme ve izod darbe testleri gerçekleştirilmiştir. GA-LSTM modeli, kullanılan parametreler ve deneysel süreç boyunca elde edilen sonuçlarla eğitilmiş ve tahmin edilen değerlerin gerçek değerlere karşılık geldiği belirlenmiştir. Hibrit GA-LSTM modelinin başarısını ölçmek için iyi bilinen yöntemler kullanılmıştır. Elde edilen sonuçlara göre tasarlanan GA-LSTM modeli en iyi sonuçları üretmiştir.
- MakaleAçık Erişim2024Experimental Investigation of Rejuvenated Asphalt Mixtures Using Bio-Oils from Different Biomass Sources
Altundoğan, Hamdi Soner; Furtana, Beyza; Yılmaz, Mehmet
Asphalt mixes containing Recycled Asphalt Pavement (RAP) materials are generally harder than traditional mixes. Different rejuvenators are used to soften recycled asphalt pavement by reducing this hardness. In this study, recycled asphalt pavement was added to bituminous hot mixtures at 3 different rates (25%, 50% and 75%). To rejuvenate bituminous hot mixtures containing RAP, three different rejuvenators (pine cone, olive pomace and wheat straw) were added to the mixtures. This study investigated the effect of asphalt mixtures containing RAP and rejuvenator on the mechanical properties. Marshall test and moisture damage test were performed to examine the mechanical properties of asphalt mixture samples. As the bio-oil content in asphalt mixtures increases, the stability values of the mixtures decrease. As the bio-oil ratio in asphalt mixtures increases, tensile strength (TS) values decrease in both unconditioned and conditioned mixtures. While the increase in bio-oil reduces the tensile strength ratio, the shrinkage ratio of mixtures prepared with RAP increases. The bio-oil derived from pomace has been identified as the most effective rejuvenator among those tested.
AtıfOpenAlex1TR Dizin1İncele - MakaleYalnız künye2024Mimarlık Eğitiminde Bir Stüdyo Çalışması: Tunceli Doğa Kampüsü Projesi
Güngör, Gizem Nur; Ceylan, Ebru Nalan
Doğa Kampüsleri dünyada giderek yaygınlaşmakta olup ekolojik hassasiyetleri ön planda olan projelerdir. Bu çalışmada ülkemizde de örnekleri bulunan Doğa Kam-püslerine dair uygulanabilir çözümler getirebilmek amacıyla Munzur Üniversitesi Mimarlık Bölümü 2. Sınıf Mimari Tasarım stüdyosunda üretilen öğrenci projeleri ve tasarım süreci ele alınmıştır. Üç temel aşamada gerçekleştirilen stüdyo çalışmasının ilk aşaması, öğrencilerin Tunceli İl Milli Eğitim Müdürlüğü’ne tahsis edilmiş olan Örenönü Mevkiinde Pülümür Çayı kenarındaki 49.000 m2lik arazinin analizi çalış-masıdır. İkinci aşamada dünyadaki ve Türkiye’deki orman okulları örnekleri ince-lenmiştir. Ekolojik mimari, sürdürülebilir mimari, doğal yapı malzemeleri, perma-kültür, azaltma, yeniden kullanma, dönüştürme ve biyofilik tasarım kavramları araş-tırılmıştır. Öğrenciler vaziyet planı ölçeğinde tasarım çalışmaları yaparak temel ta-sarım kararlarını vermişlerdir. Projelerde kullanılacak malzeme panoları ve detayları hazırlanmıştır. Üç boyutlu görsellerle ve animasyonlarla proje yürütücülerine su-numların yapıldığı son aşama ise öğrenim çıktılarına yönelik değerlendirmelerin de yapıldığı çalışma adımıdır. Stüdyo çalışmasının sonucunda öğrenciler 8 adet proje geliştirmiş olup bunların beş tanesi bu makalede sunulmuştur. Doğal yapı malzeme-lerinin kullanımının tercih edildiği projeler, doğaya uyum, işlevsellik, teknik ve es-tetik açıdan değerlendirilmiştir. Çalışmanın sonucunda talep edilen mekanların do-ğada eğitim felsefesini bozmadan, doğayı tahrip etmeden, doğal ve sökülüp takılabi-len yapı malzemeleri ve esnek mekân anlayışıyla, yaratıcı ekolojik çözümler ve sür-dürülebilir bir yaklaşımla tasarlanabileceği ortaya konmuştur.
- MakaleAçık Erişim2024Effect of Ground Diatomite on Early Strength of Self-Compacting Mortars
Karabulut, Büşra; Yon, Merve Sahin; Karataş, Mehmet
Portland cement fabrication is a significant factor that increases the amount of carbon dioxide released into nature. For this reason, it is very important to use natural and waste materials with pozzolanic properties instead of portland cement. In this article, the usability of diatomite rock, a natural pozzolanic material that can be substituted with portland cement, in the manufacture of self-compacting mortar was studied. In the experimental study, prismatic specimens with dimensions of 40 × 40 × 160 mm were used to examine the impact of ground diatomite on the early age mechanical properties of self-compacting mortar; it was produced by replacing 0%, 5%, 10%, 15%, 20% of diatomite with portland cement, respectively. The slump-flow test to obtain self-compacting mortar was conducted according to the European Federation of Specialized Construction Chemicals and Concrete Systems guidance. Specimens prepared using 0%, 5%, 10%, 15% and 20% diatomite were cured in water at 23±2 ̊C temperature for 3 days. 3-day (early age) flexural and compressive strength worths were gained for the samples whose curing period was completed. As a result of this experimental study, it was specified that the highest strengths were in the series containing 5% diatomite, exceeding the reference samples. Additionally, it has been determined that mechanical strength decreases when the diatomite ratio in mixtures is more than 5%.
AtıfOpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ1Mechanical, wear and thermal properties of natural fiber-reinforced epoxy composite: cotton, sisal, coir and wool fibers
Tasgin, Yahya; Demircan, Gokhan; Kandemir, Seckin; Acikgoz, Abuzer
Natural fiber-reinforced epoxy composites (NFRCs) have gained significant attention in recent years due to their potential as environmentally friendly and sustainable materials. These composites combine natural fibers, derived from plants, with epoxy resins to create a material with enhanced properties. The objective of this study is to investigate the mechanical, wear and thermal properties of NFRCs incorporating cotton, sisal, coir and wool fibers. The vacuum-assisted resin transfer molding (VARTM) technique was employed to produce composite plates, followed by conducting tests on tensile, wear and thermal properties. The cotton composite showcased the highest tensile strength, reaching 52.81 MPa, while the coir composite exhibited the lowest, measuring 15.34 MPa. Sisal composite exhibited a moderate wear rate (1.423 mm3/Nm) and a lower coefficient of friction (0.233), implying smoother relative motion. Coir composite presented the highest wear rate (4.615 mm3/Nm), attributed to its coarse fiber nature. Thermal conductivity is highest at cotton composite (1.017 W/mK) and is lowest at coir composite (0.187 W/mK). Additionally, the highest specific heat was observed in the coir composite (26.313 MJ/m3K). Cotton demonstrated potential for efficient heat transfer, while wool outperformed in insulation. Sisal displayed versatility for structural applications. Coir emerged as an effective insulator with energy-saving applications.
AtıfScopus101WoS83OpenAlex102İncele - MakaleAçık Erişim2024Scopus SJRQ2Is Cladophora fracta an efficient tool of accumulating critical raw materials from wastewater and there a potential health risk of use of algae as organic fertilizer?
Arslan Topal, E. Işıl; Öbek, Erdal; Topal, Murat
In this study investigation of accumulations of critical raw materials (cobalt (Co), antimony (Sb), vanadium (V), lanthanum (La) and tungsten (W)) from wastewater by using C. fracta were aimed. Besides, assessment of the potential health risks in terms of the use of organic fertilizer obtained from the macroalga to be harvested from the treatment were also aimed. Highest Co, Sb, V, La and W accumulations by algae in reactor were 125±6.2%, 201.25±10%, 318.18±15%, 357.97±18%, and 500±25%, respectively. When compared with control, Co, Sb, V, La and W in algae increased 2.25, 3.01, 4.18, 4.58, and 6 times, respectively. The algae was very high bioaccumulative for Co and La. Highest MPI was calculated as 3.94. Non-carcinogenic risk of CRMs according to different exposure types (ingestion, inhalation, and dermal) were calculated for man, woman and child. There is not any non-carcinogenic risk from the investigated exposure ways of algae as organic fertilizer.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleYalnız künye2024Scopus SJRQ2Mechanical and thermal properties of short banana fiber reinforced polyoxymethylene composite materials dependent on alkali treatment
Doğan, Akar; Güneş, Çağdaş
The present study aimed to develop a recyclable composite material based on a natural product, namely banana fiber, instead of synthetic reinforcement elements such as glass fiber or carbon fiber in thermoplastic matrix composites employed in many aspects of daily life. Polyoxymethylene (POM) thermoplastic was used as the matrix material. 3 %, 6 %, and 9 % by weight short natural banana fiber was used as reinforcement. Furthermore, the study improved the mechanical and thermal properties of the composite material with chemical improvements based on alkali treatment of banana fiber. Banana fiber and POM was initially mixed mechanically and then extruded at temperatures between 170 and 190 °C to obtain a homogeneous mixture. The mixture obtained by extrusion was initially cooled in the cooling pool and then passed through the crusher to obtain granules. These granules were pressed in plastic injection molds to obtain standard test samples. The ratio of reinforcement material and the variations in mechanical and thermal properties of the composites induced by the alkali treatment are presented in figures and tables. Furthermore, the changes in cross-sectional material images were examined with electron microscopy scans. The tensile and flexural strength of the material improved with alkali treatment.
AtıfScopus21WoS19OpenAlex20İncele - MakaleAçık Erişim2024Scopus SJRQ2Leachate treatment via electrocoagulation–coal-based powdered activated carbon process: Efficiencies, mechanisms, kinetics, and costs
Ogedey, Aysenur; Oguz, Ensar
This study aims to improve COD, NH3-N, and turbidity removal from Bingöl's leachate using a single-reactor integrated electrocoagulation (EC)–coal-based powdered activated carbon (CBPAC) process under various experimental conditions. In the EC-CBPAC process, three stainless-steel cathodes and three aluminum electrodes were connected to the negative and positive terminals of the power supply, respectively. The initial concentrations in the leachate were 1044 mg O2/L for COD, 204 mg/L for NH3-N, and 57 NTU (or 71.25-mg (NH2)2H2SO4/L) for turbidity, respectively. After a 40-min EC-CBPAC process, with a CBPAC dosage of 5 g/L and pH of 5 for COD and turbidity, and 9.5 for NH3-N, the optimum removal efficiencies for COD, NH3-N, and turbidity were achieved at 92%, 40%, and 91%, respectively. When the EC process was applied without CBPAC under the same experimental conditions, the removal efficiencies of COD, NH3-N, and turbidity were 87%, 28%, and 54%, respectively. Before and after the EC-CBPAC process, the Brunauer–Emmett–Teller (BET) surface area, pore volume, and mean pore diameter of the CBPAC were found to be (888 m2/g, 0.498 cm3/g, and 22.28 Å) and (173 m2/g, 0.18 cm3/g, and 42.8 Å), respectively. The optimum pseudo-first-order (PFO) rate constants for COD, turbidity, and NH3-N were determined to be 3.15 × 10−2, 4.77 × 10−2, and 8.8 × 10−3 min−1, respectively. With the current density increasing from 15 to 25 mA/cm2, energy consumption, unit energy consumption, and total cost increased from 68.7 to 122.4 kWh/m3, 6.948 to 15.226 kWh/kg COD, and 0.85 to 1.838 $/kg COD, respectively. Practitioner points: EC-CBPAC process has greater COD, NH3-N, and turbidity removal efficiency than EC process. COD and turbidity achieved their optimum disposal efficiencies at 92% and 91%, respectively, at pH 5 The most efficient disposal efficiency for NH3-N was observed to be 40% at pH 9.5. EC-CBPAC process increased removal efficiencies for COD, NH3-N, and turbidity by 20%, 19%, and 38%, respectively, compared with EC alone. The turbidity, NH3-N, and COD disposal fitted PSO model due to high correlation values (R2 0.94–0.99).
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Process optimization and modeling of Pb(II) ions adsorption on a new and reusable biocomposite material using experimental design approach
Ince, Muharrem; Kaplan Ince, Olcay; Alp Kavlo, Hevidar
This research paper aimed to establish the optimal conditions for lead (Pb(II)) ions from industrial wastewater (IW) using response surface methodology and central composite design (CCD) approach. A fixed-bed column study was designed by using a novel and reusable biocomposite material, Amanita vaginata (A. vaginata) immobilized on Amberlite XAD-4 resin (A&XAD-4@AV), to find out biosorption behavior of Pb(II) ions. Various experimental variables such as optimum pH value, biocomposite material amount, flow rate, and Pb(II) ions initial concentration were investigated, which significantly affected the Pb(II) ions removal efficiency. The maximum Pb(II) removal efficiency of A&XAD-4@AV biocomposite material was determined as 11.2 mg g−1 under optimum conditions. The reusability of A&XAD-4@AV biocomposite material was found to be suitable. For checking model adequacy, a regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was performed. It was observed that the quadratic model, which was controlled and proposed, originated from experimental design data. The ANOVA showed a high coefficient of determination (R2 = 0.9896, R2Adj = 0.9800, R2Pred = 0.9633). Finally, developed and optimized method was applied effectively to wastewater for determining Pb(II) ions levels. The current study indicated that the prepared A&XAD-4@AV is an efficient material to remove of Pb(II) ions from IW.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ2Factors Affecting the Setting Times of Pumice Based Alkali-Activated Hybrid Cements
Balun, Bilal; Karataş, Mehmet
The environmental impacts of ordinary Portland cement (OPC) production have led researchers to produce alternative binders. Binders with aluminosilicate structure, such as pumice, can be used to produce one of these alternatives, alkali-activated cements. In addition, alkali-activated hybrid cements have become a type of material that combines the positive aspects of geopolymers and Portland cement. Especially in the activation of low CaO containing materials such as pumice with alkalis, the use of a small amount of OPC ensures that the alkali-activated materials can both be produced under ambient conditions and improves its strength properties. In this study, setting times of pumiced based alkali-activated hybrid cements were evaluated based on OPC amount (0%, 5%, 10%, 15% and 20%), alkaline solution/binder ratio (0.47, 0.50 and 0.53) and sodium silicate/potassium hydroxide (1, 2 and 3) ratio. In experiments carried out under ambient conditions, the silica module (2.0) of the sodium silicate solution was kept constant. As a result of the experimental studies, the increase in the OPC amount and the sodium silicate ratio shortened the setting times of the pumiced based alkali-activated hybrid materials while the alkali solution/binder ratio increased the setting times. It was determined that the factor most affects the setting times was the OPC amount. The setting time of the OPC-free pumice-based alkali-activated binders without OPC takes more than one day. As a result, increasing the amount of OPC up to 20% significantly reduced the setting times. A decreasing trend was observed in compressive strengths with increasing setting times.
AtıfScopus5WoS4OpenAlex5İncele
