WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article 3D-Printed Soy Protein and Microalga Films: A Sustainable Approach with Antioxidant Functionality(Elsevier, 2026) Barekat, Sorour; Dogan, Buse; Uzuner, Sibel; Ubeyitogullari, AliThis study investigated the optimization and fabrication of soy protein isolate (SPI)-green microalga (MA) 3D-printed films. For optimizing 3D printing, the effects of MA concentration, nozzle size (0.52-0.81 mm), and speed (10-20 mm/s) were examined. The printed films were then dried, and color, mechanical properties, water vapor permeability, structure, and antioxidant activity were analyzed. All the formulations showed shear-thinning behavior and rapid recovery. The concentration of 3 % MA, nozzle size of 0.72 mm, and printing speed of 20 mm/s were selected as the optimized conditions for the best 3D printability. Compared with the control, their elongation at break decreased by more than 16 %, while puncture strength increased by over 12 %, and tensile strength rose by more than 40 %. Water vapor permeability decreased by more than 40 % with the addition of MA. The microstructure images and secondary structure confirmed the formation of a less porous and stronger gel network with an increase in MA concentration from 0 to 5 % (w/w). The antioxidant properties of SPI films also increased two-fold with the addition of MA. These findings highlight that the 3D-printed edible films with antioxidant properties could be used as an eco-friendly and nutritious alternative to petroleum-based films in food packaging.Article Synthesis of Nannochloropsis Oculata Cultivation Process Based on Mixed-Integer Formulations(Elsevier, 2025) Kivanc, Sercan; Tuncer, Basak; Deliismail, Ozgun; Sildir, HasanSophisticated mathematical formulations and related optimization tasks are important to favor microalgae processing. This study focuses on the development of a mixed integer nonlinear programming approach to calculate design and operational decisions through simultaneous and rigorous approach under set of complex constraints and objective functions. Through a set of differential algebraic equations, whose model parameters are obtained through fitting a dataset available in the literature, three case studies are demonstrated for the calculation of optimum cultivation conditions based on economic considerations and biomass production. The case studies show the impact of the approach for the sustainability of the process as different conditions are primary defined by light color, reactor size, dilution rate, feed stream composition, and growing medium are required for desired tasks. The approach is flexible and further modifiable to various considerations for more complex decision-making problems.Article Citation - Scopus: 1Life Cycle Assessment of Black Tea Production and Consumption in Turkiye: Insights From Waste Management Scenarios(Elsevier, 2025) Uctug, Fehmi Gorkem; Küçüker, Mehmet Ali; Ediger, Volkan S.; Kucuker, Mehmet Ali; Berk, Istemi; Inan, Ali; Tugcu, MelisaThis study conducts a life cycle assessment (LCA) of tea production and consumption in T & uuml;rkiye, the world leader in per capita tea consumption. Aiming to identify environmental hotspots and propose sustainable solutions, a cradle-to-grave LCA was performed using CCaLC2 software, CML methodology, and the Ecoinvent 3.0 database. It covers cultivation, processing, transportation, and consumption stages, focusing on key environmental indicators like carbon footprint and acidification potential. The results reveal that consumption dominates the environmental footprint (91%) due to energy-intensive brewing methods. Cultivation and transportation contribute minimally (4% each). This highlights the need for promoting energy-efficient brewing practices and consumer adoption of renewable energy sources. The study also explores the environmental implications of different waste management strategies. Composting emerged as the most beneficial approach for reducing the carbon footprint and photochemical oxidants creation, while incineration might be preferable for other impact categories. This study underscores the importance of addressing energy consumption during tea brewing and encouraging renewable energy use among consumers. Additionally, it promotes composting as a crucial waste management strategy for a more sustainable tea value chain in T & uuml;rkiye. These findings offer valuable insights for policymakers, industry players, and tea drinkers to make informed decisions that minimize environmental impact.Article Citation - WoS: 7Citation - Scopus: 6A Literature Review on Sustainable Buildings and Neighborhoods in Terms of Daylight, Solar Energy and Human Factors(Elsevier, 2025) Cogul, Ilgin cataroglu; Kazanasmaz, Zehra Tugce; Ekici, BerkSustainability has become the focus and interest of researchers with climate change's increasing impact and challenges. Considering various perspectives, published studies focus on sustainability in architecture and the built environment, such as using daylight more effectively, enhancing energy efficiency, and designing nearly zero-energy buildings. Given the attention to sustain- ability in this domain, this review assesses the abovementioned viewpoints in buildings regarding environmental factors in relation to the micro and macro scales of the buildings and neighborhoods. Human factor has increasingly been of interest in recent works of sustainable environments. This study identifies the gaps with respect to architectural design elements considering daylighting, energy efficiency and human factors on building and neighborhood scales. A comprehensive table of the reviewed studies summarizes the aim, methodology, optimization algorithm, objective function, machine learning algorithm, digital tools, location, independent and dependent variables, view, wellness, well-being, daylight/energy performance metrics, scale, and solar strategy. The results showed that the current state-of-the-art focus on energy efficiency mainly considers passive design strategies at the building scale. Studies in the daylight domain primarily consider window properties, shading devices, and orientation. Human-centric studies showed that daylighting improves the emotional well-being of building occupants but can have negative effects such as overheating and glare. Overall findings emphasize the necessity of a holistic approach in achieving sustainability goals in dwellings at the building and neighborhood scale.Review Citation - WoS: 22Citation - Scopus: 30Comparative Environmental Sustainability Assessment of Biohydrogen Production Methods(Elsevier, 2023) Goren, A. Yagmur; Dincer, Ibrahim; Khalvati, Ali; Gören, Ayşegül Yağmur; Dinçer, İbrahimAs energy crisis is recognized as an increasingly serious concern, the topic on biohydrogen (bioH(2)) production, which is renewable and eco-friendly, appears to be a highly-demanding subject. Although bioH(2) production technologies are still at the developmental stage, there are many reported works available on lab- and pilot-scale systems with a promising future. This paper presents various potential methods of bioH(2) production using biomass resources and comparatively assesses them for environmental impacts with a special emphasis on the specific biological processes. The environmental impact factors are then normalized with the feature scaling and normalization methods to evaluate the environmental sustainability dimensions of each bioH(2) production method. The results reveals that the photofermentation (PF) process is more environmentally sustainable than the other investigated biological and thermochemical processes, in terms of emissions, water-fossil-mineral uses, and health issues. The global warming potential (GWP) and acidification potential (AP) for the PF process are then found to be 1.88 kg-CO2 eq. and 3.61 g-SO2 eq., which become the lowest among all processes, including renewable energy-based H-2 production processes. However, the dark fermentation-microbial electrolysis cell (DF-MEC) hybrid process is considered the most environmentally harmful technique, with the highest GWP value of 14.6 kg-CO2 eq. due to their superior electricity and heat requirements. The water conception potential (WCP) of 84.5 m(3) and water scarcity footprint (WSF) of 3632.9 m(3) for the DF-MEC process is also the highest compared to all other processes due to the huge amount of wastewater formation potential of the system. Finally, the overall rankings confirm that biological processes are primarily promising candidates to produce bioH(2) from an environmentally friendly point of view.Review Citation - WoS: 10Citation - Scopus: 14A Review on Characterization and Recyclability of Pharmaceutical Blisters(Elsevier, 2023) Capkin, Irem Yaren; Gokelma, MertolPackaging is one of the biggest sectors in the world and the use of aluminium is widespread in the packaging industry. Pharmaceutical blister packages generate a significant amount of solid waste, typically containing plastics and aluminium as thin layers. Since these packages have a complex structure with multiple layers, they are hard to recycle. A separation process of the plastic and aluminium is needed prior to recycling. Hydrometallurgical or thermal processes can be used for the separation. This work reviews the characterization of different types of blisters and the different reagents used in the separation process of the blister layers. Parameters and results of separation processes by using hydrochloric acid, formic acid, acetic acid, organic solvents, and phosphoric acid were discussed as well as the thermal degradation.Article Citation - WoS: 5Citation - Scopus: 5Exergetic Assessment of an Solar Powered Stand-Alone System Using Liquid Organic Hydrogen Carrier for Energy Storage(Elsevier, 2023) Palmero-Marrero, Ana I.; Zairov, Rüstem; Borge-Diez, David; Çağlar, Başar; Açıkkalp, Emin; Altuntaş, ÖnderThe integration of energy storage technologies into renewable energy systems has gained increasing attention for continuous supply of the renewable-based enegy. Among different storage alternatives, the use of a Liquid Organic Hydrogen Carrier (LOHC) has a significant potential as a reversible energy carrier for short and longterm energy storage. In this study, the technical and economic performance of an stand-alone renewable energy systems using a LOHC for energy storage have been evaluated by exergy-based methods in addition to simple energy and economic analysis. The analysis of the LOHC-free system was also included to determine the effect of LOHC on the system performance. The system containing phovoltaic (PV) panels, an electrolyzer, a micro gas turbine and hydrogenation/dehydrogenation LOHC units was designed to meet the power, heating and cooling requirement of a residential building. The system modelling and performance evaluation were made by using TRNSYS and EES softwares. Results show that the LOHC-containing system has higher energy and exergy efficiencies and exergoeconomic performance than the LOHC-free system while the latter is economically more feasible than the former due to its low capital investment cost.Review Citation - WoS: 42Citation - Scopus: 49Utilization of Waste Materials in the Stabilization of Expansive Pavement Subgrade: an Extensive Review(Elsevier, 2023) Tanyıldızı, Muhammed; Uz, Volkan Emre; Gökalp, İslamExpansive soils, also known as swell-shrink soils, are one of the most problematic soils in highway construction and exhibit significant volume changes by swelling and shrinking while wet and dry, respectively. These changes in soil cause cracks, heaves, differential settlements, and damages to the overlying pavements leading to high maintenance costs. The annual average maintenance cost of structures built on expansive soils ranges from $9 to $15 billion, with 50% of the expenses associated with highways and streets. Chemical stabilization techniques such as cement and lime stabilization are one of the most efficient ways to treat expansive soils. However, there is a need to develop environmentally friendly approaches to stabilize expansive soils due to worldwide growing interest in sustainable developments and concerns about greenhouse gas emissions and climate change. In this context, using waste materials in soil stabilization has been considered an important issue for sustainability concerns. The aim of the current study is to review the relevant studies performed to improve the geotechnical and engineering properties of expansive subgrade soils of pavements by using waste materials arising from industrial, agricultural, and other activities in the last decade. In the organization of this study, characteristics of expansive soils including plasticity, compaction, strength & stiffness, microstructural characteristics, shrink-swell properties, and durability were focused to point out the effect of the waste materials. The overall results obtained throughout the scope of the current study indicated that the use of waste materials in soil stabilization improves the engineering properties of expansive soils, significantly. This paper also provides key information and creates awareness for researchers and sector representatives about sustainable soil stabilization.Article Citation - WoS: 17Citation - Scopus: 19Development of Ca(oh)2-Based Geopolymer for Additive Manufacturing Using Construction Wastes and Nanomaterials(Elsevier, 2023) Mortada, Youssef; Masad, Eyad; Kogbara, Reginald B.; Mansoor, Bilal; Seers, Thomas; Hammoud, Ahmad; Karaki, AymanRecent growth in additive manufacturing (AM) or 3D printing in the construction field has motivated the development of various materials that vary in its composition and properties. This paper introduces, characterizes, and evaluates the performance of a sustainable and environmentally friendly geopolymer mixture composed of construction wastes. The geopolymer mixture has calcium hydroxide (Ca(OH)2) as the main alkaline activator and incorporates nanomaterials such as nano-silica and nano-clay to enhance its suitability for AM. The combined use of Ca(OH)2 for alkali activation, and nanomaterials for tailoring the behavior of construction wastes for 3D printing, is novel and addresses the shortcomings of conventional alkaline activators. The paper includes the outcomes of the analysis of the mechanical properties, printability, and microstructure of the geopolymer mixture. The 28-day compressive strength of the mixture reached 42 MPa with ambient temperature curing, which is comparable to traditional geopolymers. The inclusion of 1 wt % of nano-silica accelerated the geopolymerization process and led to the largest (35 %) reduction in the setting time. Similarly, incorporating 1 wt % of nano-clay led to reduction of the thermal conductivity from 0.709 W/mK to 0.505 W/mK, due to the introduction of thermal barriers. The printability of the studied waste-based geopolymer mixture was validated through the successful fabrication of a 3D-printed model. © 2023 The AuthorsArticle Citation - WoS: 15Citation - Scopus: 16Proposal of Novel Exergy-Based Sustainability Indices and Case Study for a Biomass Gasification Combine Cycle Integrated With Liquid Metal Magnetohydrodynamics(Elsevier, 2023) Canpolat Tosun, Demet; Açıkkalp, Emin; Çağlar, Başar; Altuntaş, Önder; Hepbaşlı, ArifExergy is considered a way to sustainability. Exergy-based analyses have been recently widely used for performance assessment and comparison purposes of energy systems from production to end-user while different sustainability related indices or indicators including exergetic concepts have been developed in the literature. In this regard, the present study proposed five different indices: (i) Exergetic Fuel Based Environmental Remediation Index (X), (ii) Exergetic Product Based Environmental Remediation Index (delta), (iii) Exergetic Fuel Based Total Environmental Remediation Index (beta), (iv) Exergetic Product Based Total Environmental Remediation Index (alpha), and (v) Improved Sustainability Index (ISI). These indices were applied to a novel Biomass-integrated Gasification Combine Cycle (BIGCC) integrated with Liquid Metal Magnetohydrodynamics (LMMHD). They allowed to perform a more complete environmental analysis by considering the exergetic cost of environmental remediation of the process. The average exergy efficiency values for the BIGCC, LMMHD and the overall system were determined as 0.491, 0.222 and 0.688 under daily ambient temperatures for a year and different air to fuel ratio (AFR) conditions, respectively. The average values for.X, beta, delta, alpha and ISI were 1.636, 2.389, 1.949, 2.848 and 0.513, respectively.