IYTE GCRIS Database (Izmir Institute of Technology)
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Design and Performance of Sioc Foam-Silica Aerogel Composites for Hot and Cold Thermal Management Applications
No full textThis study focuses on the fabrication of monolithic preceramic polymer-derived ceramic (SiOC) foam-silica aerogel composites by filling the open cells of ceramic foam with a silica aerogel solution using the sol-gel technique. The effects of different drying techniques (ambient pressure vs CO2 supercritical drying) and surface modification agents, including trimethylchlorosilane (TMCS) and hexamethyldisilazane (HMDZ), are comprehensively investigated. These factors are analyzed for their influence on the composites' morphology, porosity, chemical structure, and thermal insulation performance. The drying technique and surface modification agents are found to play a critical role in achieving a high filling ratio of silica aerogel within the composites. Pure silica aerogels exhibit specific surface areas (SSAs) reaching ∼1120 m2.g-1, while the SiOC foam-silica aerogel composites demonstrate SSAs of 385–440 m2.g-1. Nearly all samples achieve a total porosity of ∼93 vol%. Surface modification effectively tailors the surface properties, imparting hydrophobicity with a water contact angle of 133°. Thermal conductivity at room temperature ranges between 38 and 43 mW·m-1·K-1. The potential applications of these SiOC foam-silica aerogel composites as thermal insulators are assessed under extreme thermal conditions. For instance, a 14 mm thick composite has a temperature of -27 °C when subjected to a cold source at -78 °C. Instead, when exposed directly to a butane flame (∼1200 °C), the backside of the composite recorded only ∼57 °C. © 2025 Elsevier Ltd and Techna Group S.r.l
The Future Classroom: Leveraging Technology for Enhanced Educational Practices
No full textTechnology has been evolving for the better of humanity, and advancements in technology have been ongoing with an immense speed. As a crucial part of our lives, technology is being extensively used in many spheres of life. Owing to the numerous benefits it provides and the contributions it makes both to the teaching and learning processes, technology has also become a controversial topic in education recently. Technology entails numerous advantages in the 21st century; however, it is the pedagogy that differentiates the educational processes. Hence, teachers play a critical role in effectively exploiting technology for educational purposes. Education 5.0 requires educators to become technology-literate and use instructional technologies to enhance the effectiveness of education and humanize technology, exerting ongoing effort and making continuous reflection. The objective of this chapter is to explore the most innovative pedagogies, methodologies, and strategies educators can exploit while integrating technology into instruction. © 2025 by IGI Global Scientific Publishing. All rights reserved
Analysis of Microplastic Flux From the Gediz River To the Aegean Sea: a Modeling Study for Environmental Management
No full textIt is critical to determine the abundance of microplastics in terrestrial inland waters, understand their fate and transport mechanisms, and reveal their status in aquatic environments. This study aimed to develop and calibrate a mathematical model to simulate microplastic (MP) pollution in the Gediz River Basin, T ; uuml;rkiye, which focused on MP fate and transport under existing conditions and various management scenarios. The baseline scenario revealed that, despite a ninefold difference in flow rates, the midstream and upstream parts of the basin also exhibited significant contamination, with an average concentration of 25 n/L compared to the downstream average of 29 n/L. The model was later simulated to test the effects of various mitigation scenarios including but not limited to reducing MP discharges from wastewater treatment plants (WWTPs) and implementing vegetative barriers in tributaries. Scenario 4, which involves reducing MP concentrations in upstream tributaries with vegetative barriers, achieved the highest average reduction across all segments (32 %) and specifically in the downstream area (47 %). In contrast, Scenario 1, aimed at reducing wastewater discharges from urban and industrial WWTPs through water reclamation, and Scenario 2, which focused on eliminating MP in Organized Industrial Zone (OIZ) discharges by changing industrial inputs, achieved the most effective MP reductions in the upper basin, with reductions of 20 % and 17 %, respectively. Scenario 3, targeting flow reduction and accumulation through constructed wetlands, had minimal impact, with reductions close to 0 % in most areas. These results highlight the need for comprehensive approaches to effectively reduce MP pollution, particularly in managing upstream and tributary sources
Flavonoids as Chemosensitizers in Leukemias
No full textFlavonoids, a diverse group of natural compounds abundant in plants, fruits, and seeds, are not only responsible for the vibrant colors, fragrances, and flavors found in nature but also possess significant health benefits. Representing a secondary metabolite, these phytonutrients contribute to overall well-being. They have garnered considerable interest due to their diverse biological roles, encompassing antioxidant, anti-inflammatory, and anticancer properties. Flavonoids exert anticancer properties by interfering with different signaling pathways and molecules. Also, they have been demonstrated to exert chemosensitization features, where flavonoids may enhance the effectiveness of chemotherapy, and hold promise for improving cancer treatment outcomes as they have been discovered to make cancer cells more responsive to treatment. Understanding their influence on the regulation of cellular signaling provides a foundation for exploring their potential in combination with different chemotherapy agents and their possible single use for cancer treatment. Besides, they are believed to present a cost-effective approach to cancer therapeutics with possible implications for reducing the side effects of the current chemotherapy regimens, which can be a great therapeutic strategy for treating cancer types, including leukemia. This chapter explores potential approaches for creating anticancer treatments, focusing on leukemia, through integrating flavonoid nutraceuticals with traditional chemotherapy agents. © 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG
Nonlocal Static Modeling of Laminated Composite Shells Using Peridynamic Differential Operator in a Higher-Order Shear Deformation Framework
No full textThis study investigates the flexural behaviour of the laminated composite shells in the framework of Higher-Order Shear Deformation Theory (HSDT) and Peridynamic Differential Operator (PDDO), namely PD-HSDT, for the first time. Laminated composite shell structures are widely used in aerospace, automotive, and marine industries due to their high strength-to-weight ratio and design flexibility. Therefore, understanding their mechanical behavior under various loading conditions is crucial for ensuring structural reliability and performance optimization. However, such structures may possess complex curvatures and highly heterogenous laminate stackings, leading to inaccurate numerical stress analyses. The HSDT successfully captures displacement and stress distributions as well as cross-sectional warping through higher-order functions exist in the kinematics. Moreover, the PDDO represents the local derivatives in their nonlocal form, making it well-suited for problems involving higher-order derivatives and discontinuities. The governing equations and boundary conditions of the HSDT are solved by using the PDDO to accurately achieve the stress and displacement fields in the laminated composite shells. The robustness of the PD-HSDT is established by considering various loading and boundary conditions. The proposed approach demonstrates high accuracy in stress and displacement predictions when validated against reference solutions available in existing literature. This indicates strong potential for extending the methodology to more complex loading scenarios and damage mechanisms in future studies. © 2025 The Author
The Future of European Regional Inequalities: Box-Cox Transformed Arma Process Trend Smoothing (Bats) Forecasting
No full textThe vast majority of the empirical studies on regional economic inequalities has analyzed the past evolutions, while the future trajectories are often ignored. Despite, no methods exist to predict the future precisely, it is worthwhile to shed light on the prospective tendencies in order to plan and formulate the policies at the present time. The current study addresses the following questions; Will regional convergence continue in Europe? Which regions will become more prosperous? What are the future determinants of regional growth? Our dataset covers 236 NUTS-2 regions belonging to the 28 European Countries for the period 2000-2022. In terms of methodology, we use a nonlinear forecasting technique BATS ("Box-Cox Transformation, ARMA errors, Trend and Seasonal Components") model and Spatial Durbin Regressions along with explorative maps and descriptive statistics. As an outcome of the analyses, we obtained several remarkable results. First, regional inequalities are expected to widen by 2050 indicating the evidence of regional divergence. Second, spatial poles of prosperity are likely to change substantially. Most of the regions belonging to the countries in the "Mediterranean Basin" are predicted to remain relatively backward while many Eastern European regions are expected to rise in prosperity. Northern and Central European regions are likely to keep their prosperous position. Third, several crucial determinants of future growth patterns are detected. It appeared that younger demographic profile, industrialization and cohesion policies (particularly for CEE regions) have become key factors of future growth performance
Experimental and Numerical Investigation of Vertical Temperature Gradients in Warehouses: Retrofit Interventions To Manage Temperature Sensitive Products
No full textThis paper investigates vertical temperature gradients in warehouse design to ensure optimal storage conditions. In warehouses with ceilings over 10.0 m high, buoyancy-driven warm air often causes significant temperature disparities. This study uses a combination of field measurements and computational fluid dynamics (CFD) simulations to measure thermal stratification. It also examines the impact of mechanical systems, such as ceiling- mounted radiant cooling and floor heating. CFD simulations are validated against field data, showing that destratification cooling systems can reduce ceiling temperatures by up to 4.0 degrees C in summer. These systems can also raise floor temperatures by 7.0 degrees C during heating. Field data collected over a year show vertical temperature gradients up to 3.0 degrees C. However, the temperature difference between ceiling and floor remains below 0.2 degrees C, keeping indoor temperatures within an ideal range of 20.0-24.0 degrees C year-round. The study highlights the benefits of combining radiant cooling with floor heating to achieve temperature uniformity. Floor heating scenarios generate air velocities of up to 0.8 m/s, with an average velocity of 0.2 m/s. In contrast, ceiling-mounted cooling systems result in slightly lower air velocities, reaching a maximum of 0.5 m/s and an average of 0.1 m/s. This research is especially relevant for temperature-sensitive products, as illustrated by a case study involving cured tobacco bales. The retrofit proposals ensure optimal indoor conditions and reduce vertical temperature gradients. These findings validate the proposed methodology as a reliable approach for managing temperature variations in warehouses handling temperature-sensitive goods
Biquandle Power Brackets of Oriented Links
No full textIn this paper, we introduce biquandle power brackets, an infinite family of invariants of oriented links containing the classical skein invariants and the quandle and biquandle 2-co cycle invariants as special cases. Biquandle power brackets are generalizations of biquandle brackets in which the values of Kauffman states also depend on the biquandle colors they admit. We provide example computations and discuss the relationship between these new invariants and the previous cases
Enhancing trajectory-tracking accuracy of high-acceleration parallel robots by predicting compliant displacements
No full textFor precision-required robot operations, the robot's positioning accuracy, repeatability, and stiffness characteristics should be considered. If the mechanism has the desired repeatability performance, a kinematic calibration process can enhance the positioning accuracy. However, for robot operations where high accelerations are needed, the compliance characteristics of the mechanism affect the trajectory-tracking accuracy adversely. In this paper, a novel approach is proposed to enhance the trajectory-tracking accuracy of a robot operating at high accelerations by predicting the compliant displacements when there is no physical contact of the robot with its environment. Also, this case study compares the trajectory-tracking characteristics of an over-constrained and a normal-constrained 2degrees-of-freedom (DoF) planar parallel mechanism during high-acceleration operations up to 5 g accelerations. In addition, the influence of the end-effector's center of mass (CoM) position along the normal of the plane is investigated in terms of its effects on the proposed trajectory-enhancing algorithm
Super Citizens: the Power of Social Innovation in İzmir/Turkey
No full textThis study aims to define the characteristics of social innovators, measure the impact of social innovation, and investigate its effects on urban transformation in İzmir. The study is based on semi-structured interviews with 14 social innovators and conducted by adopting a conceptual framework. We identify the characteristics of ‘super citizens’ in the literature that can contribute to SI’s empowerment in cities. The first finding shows that these individuals are expected to have 8 characteristics: being an activist, a social entrepreneur, a mediator, having a wide network, organizing goal-oriented works, involving all actors in the process, producing new solutions focused on the subject and finally being able to keep up with the change. The second finding shows that they are the most important actors in sustaining urban development, and their projects have impacts on urban transformation from a city level to an international level. If the interaction mechanism between relevant actors is provided by the local government through the Penta-helix model, super citizens may become one of the primary stakeholders to promote SI and create a more sustainable urban development. © 2024 The European Association for the Advancement of the Social Sciences