Istanbul Technical University
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Exploring Robotic Arm Dynamics in Mobile Platforms for Space Industrial Applications
No full texthttps://doi.org/10.1007/978-3-031-81458-7_1
Sainfoin (Onobrychis viciifolia L.) protein isolate as a new source of alternative plant-based protein: cytotoxicity, immunoreactivity, nutritional and functional properties
No full texthttps://doi.org/10.1007/s00217-025-04910-
Lityum-iyon elektrikli araç bataryasının ve termal yönetiminin modellenmesi
No full textThesis (M.Sc.) -- Istanbul Technical University, Graduate School, 2025Electric vehicles (EVs) have become a key component of modern transportation strategies aimed at reducing carbon emissions, improving air quality, and decreasing reliance on fossil fuels. With the increasing demand for high-performance EVs, the need for efficient and reliable battery systems has increased. In this context, researchers and EV manufacturers conduct studies and develop solutions to maintain the EV batteries in a safe and optimum temperature range to achieve better battery performance and to prevent aging of the batteries. As a result of the literature review, it has been observed in the studies that battery cooling systems are generally designed based on the assumption of constant heat generation, without adequately addressing the dependency of heat generation on the state of charge (SoC) of the battery. In this thesis, a validated battery model that can compute heat generation and temperature distribution in a prismatic Li-Ion battery was developed, and a battery cooling system was designed to maintain battery temperature in the optimum range with minimum hydraulic power. To achieve this objective, a prismatic Li-ion battery with a nominal capacity of 155 Ah (168.32 Ah) was employed in this thesis, as it is well-suited for EV applications due to its high energy density and stable voltage characteristics. First, the battery was discharged from 100% to 0% state of charge (SoC) to determine the actual capacity of the battery. As a result of the experiment, the actual capacity was determined as 168.32 Ah. Then, the battery was tested experimentally with the HPPC procedure to capture the dynamic response of the battery. For numerical studies, the battery geometry was modeled in Solidworks, and a mesh model of the battery was generated in ANSYS Fluent. The parameters of the ECM were determined with test data derived from the HPPC test. Subsequently, the battery model was constructed by integrating the ECM parameters with a Multi-Scale Multi-Domain (MSMD) framework. After the electrothermal battery model was defined in the ANSYS Fluent, six different points were determined on the battery surface to monitor the temperature distribution on the battery geometry and validate the developed battery model with the experimental tests. Once the experimental test and the simulation for battery model validation, which were conducted under identical discharge and environmental conditions, were completed, the simulation temperature results were compared with the temperature measurements obtained from the experimental test. Following the validation of the battery model, designed battery cooling plate was located lateral side of the geometry and the battery was simulated under a power cycle derived from a driving cycle. The simulations were conducted using transformer oil, 50% water–glycol mix, and water at 0.00625, 0.0125, 0.025, and 0.05 m/s inlet velocities. As a result of the numerical simulation studies, the maximum and average battery temperatures, the temperature difference within the battery, the pressure drop across the cooling channels, and the required hydraulic power were obtained. Based on these results, the effects of the cooling fluid type and the inlet flow velocity on the battery thermal management performance were thoroughly investigated. The investigation revealed that the temperature in the battery decreased effectively with increasing inlet velocity. However, inlet velocities above 0.0125 m/s did not result in a significant reduction in battery temperature for all the cooling fluids. At higher inlet velocities, similar battery temperatures were obtained across all cooling fluids, whereas battery temperatures were became different as the inlet velocity decreased. Specifically, at the lowest inlet velocity of 0.00625 m/s, the maximum battery temperature obtained with the 50% glycol–water mixture was approximately 1% higher and the maximum temperature observed with transformer oil was 9.21% higher compared to maximum temperature obtained with water as cooling fluid.M.Sc
Comparing Type I and Type II Codebooks in 5G MIMO with Imperfect CSI at the Receiver
No full textMassive MIMO and beamforming are key enablers in 5G-NR, relying heavily on accurate CSI feedback to realize their potential. The 5G-NR standard includes Type I and Type II codebooks to facilitate CSI-based precoding, with Type II offering greater flexibility at the cost of higher complexity. This paper investigates the impact of imperfect CSI on the performance of these codebooks under realistic propagation conditions. By comparing BLER performance for different modulation schemes and channel profiles, we show that the advantage of Type II diminishes under high CSI error, especially in LOS scenarios. In contrast, under NLOS conditions, Type II consistently outperforms Type I when CSI quality is moderately preserved. These findings emphasize that the reliability of CSI acquisition plays a pivotal role in selecting the appropriate codebook, and that the robustness of Type I under imperfect CSI may be favorable in severely degraded conditions - a critical insight for future 6G codebook and beamforming design.https://doi.org/10.1109/meditcom64437.2025.11104459https://doi.org/10.1109/MeditCom64437.2025.11104459https://hdl.handle.net/11583/3002727https://ieeexplore.ieee.org/document/1110445
Implications of NFV-SDN technology: An exploratory study of Turkish telecom industry
No full texthttps://doi.org/10.1080/1097198x.2025.248097
Design of the New Classic and Quantum Chaotic Maps and Implementation on FPGA
No full textAbstract We review and simplify several classical and quantum maps introduced in recent years that have been used in cryptography. For each of these maps, a bitstream is generated and subjected to the NIST test. Leveraging the advantages of FPGA in the loop, these maps are designed in MATLAB Simulink, converted to HDL using HDL Coder, and implemented on FPGA. Vivado software is used for more precise synthesis of the implementation of these maps. The results of a detailed analysis of classical and new quantum maps are compared with each other, as well as with other implementations of chaotic maps in the literature. Implementations related to five classical maps and two quantum maps, with maximum frequencies 125 MHz, and maximum throughputs of 4 Gbps, are confirmed. The suitability of these maps for implementation, leveraging their greater dynamic complexity and larger key space, is evident.https://doi.org/10.1007/s13369-024-09899-
A novel MAP7D1 mutation causes mitotic defects and RPS14 accumulation in Shwachman−Diamond syndrome patient cells
No full textABSTRACT The importance of microtubule stability and microtubule-associated proteins in the etiology of Shwachman−Diamond syndrome (SDS) has been highlighted in recent studies. In one patient with SDS, a novel MAP7D1:c.601C>T, p.R201W variant has been identified. In this study, the causality of this variant in the pathogenesis of SDS was investigated. Mutation in the microtubule-binding domain of MAP7D1 caused disruption of its interaction with microtubules. SDS fibroblasts exhibited a decreased cell size with reduced microtubule density, and mitotic defects, including multipolar or bipolar unstable spindles, lagging chromosomes, and shortened inter-centrosomal distance. Additionally, ribosomal protein S14 (RPS14) accumulated within incorrectly dividing SDS fibroblasts. To further evaluate whether these abnormalities are directly attributable to the MAP7D1 mutation, mitotic processes were investigated through genetic manipulations of MAP7D1 in T98G glioblastoma and HEK293T embryonic kidney cell lines. Consistent with data from SDS fibroblasts, similar phenotypes were detected upon overexpression of mutant MAP7D1 and depletion of MAP7D1. Our findings revealed that the MAP7D1 mutation acts as a loss-of-function mutation and contributes to SDS pathogenesis by disrupting microtubule dynamics and ribosomal protein regulation, identifying MAP7D1 as a gene with substantial impact for SDS.https://doi.org/10.1242/dmm.052409https://pmc.ncbi.nlm.nih.gov/articles/PMC12421802/https://pubmed.ncbi.nlm.nih.gov/40856631
Döner kanatlarda değişken pal açıklığı: performans analizi ve mekanizma seçimi
No full textThesis (M.Sc.) -- Istanbul Technical University, Graduate School, 2025The aviation industry is a continuously evolving field that aims to produce more efficient aircraft. Today, a wide variety of aircraft capable of performing different missions are available. Therefore, achieving high performance and efficiency under various flight conditions with a single aircraft has become a significant goal in both fixed-wing and rotary-wing systems. To meet these requirements, the use of shape-changing or morphing structures has become increasingly prevalent. Morphing structures allow the aerodynamic surfaces of an aircraft to change shape dynamically during flight. These changes can include variations in wingspan, chord, twist, camber, and dihedral angle. By changing the geometry of the lifting surfaces, aircraft can adapt to various flight conditions, thereby enhancing the aircraft's flight performance, efficiency, and controllability. While morphing technologies have found strong applications in fixed-wing aircraft, integrating morphing mechanisms into rotary-wing systems, such as helicopters, is much more complex and challenging due to the operational conditions of the blades. The aerodynamic and structural loads acting on each blade at high rotational speeds can significantly affect the rotor's dynamics and structural integrity, especially when considering the added mass from morphing mechanisms. Rotorcraft operate under various flight regimes, including hover, vertical flight, and forward flight. Accurately assessing rotorcraft performance requires the use of a variety of analysis methods, each suited to the specific aerodynamic challenges that occur in different flight conditions. This is primarily due to the complexity of the airflow characteristics through the rotor disk, which changes significantly with each flight condition, affecting lift, drag, and overall rotor efficiency. Performance analysis of rotorcraft is primarily conducted using three main mathematical models. These include momentum theory, blade element theory, and blade element momentum theory. Momentum theory (MT) simplifies the rotor blade into an idealized disk. This model provides a first-order approximation by applying fundamental assumptions, including the conservation of mass, momentum, and energy. The airflow passing through the rotor is considered one-dimensional, quasi-steady, incompressible, and inviscid, allowing for a simplified analysis of thrust and induced velocity. Blade element theory (BET) divides the rotor blade into small sections and calculates the aerodynamic forces on each based-on airfoil geometry and local flow conditions. This model provides a detailed estimation of lift, drag, and thrust by summing the forces along the blade span. Blade element momentum theory (BEMT) combines the principles of both momentum theory and blade element theory. By iteratively solving the inflow distribution along the blade span, BEMT enhances the accuracy of predicting aerodynamic loads and power requirements. This hybrid mathematical model is widely used in rotorcraft performance analysis due to its accuracy and computational efficiency. In addition to mathematical models, rotorcraft performance can also be evaluated and compared using disk loading and power loading graphs across different types of rotorcrafts. Disk loading, defined as the aircraft weight divided by the rotor disk area, gives general information about hover efficiency by influencing the required induced power during hover. Power loading, defined as the aircraft's weight per unit of engine power, reflects how much power is available to support lift and propulsion in various flight regimes such as hover and forward flight. These features make these parameters especially useful for design optimization across a wide range of rotorcraft sizes and configurations. The ability to adapt the rotor span to changing flight conditions provides a performance advantage. A reduced blade span is more suitable for high-speed forward flight, while an extended span improves lift efficiency during hover and climb. This adaptability helps balance disk loading and power loading for optimal performance in each regime. Various morphing blade mechanisms enable such adaptability. These are telescopic blades, foldable blades, and flexible blades. Telescopic blades use nested sections that slide outward under centrifugal force, typically guided by rails or channels. Passive designs rely on spring or damper systems for control. Foldable and flexible blades offer compact storage and rapid deployment but often require active actuation and structural reinforcement. The centrifugal force-actuated telescopic blade system stands out among other span morphing mechanisms due to its simplicity, lightweight design, and passive operation. In this thesis, a telescoping blade mechanism actuated by centrifugal force and constrained by a spring is modeled and analyzed under different flight conditions using momentum theory. The objective is to evaluate its influence on rotor performance across hover, forward flight regimes. In this study, the momentum theory was implemented in MATLAB to model rotor performance and to evaluate the effects of blade extension under varying angular velocities. The study aims to determine whether passive span morphing can provide sufficient performance benefits in rotary-wing aircraft and compare this mechanism to alternative span morphing concepts. Insights from this research could support the development of more efficient and adaptable rotorcraft for both civilian and military applications
An Optimization Tool for Energy Efficient Building Design: Bi-Directional Energyplus Interoperability for Bim-Based Generative Design
No full texthttps://doi.org/10.2139/ssrn.511134
Future Heat-Related Mortality in Türkiye: Projections Under CMIP6 Scenarios Towards National Climate Action Targets
No full textClimate change associated with higher temperatures and more frequent/stronger heat waves has been causing adverse health effects and increasing vulnerability in the mega-city of & Idot;stanbul. To adapt to climate change and extreme heat, it is crucial to consider the associated health risks. This study aims to estimate current and future mortality risks associated with high summer temperatures in & Idot;stanbul. Using data from 2013 to 2017, mortality risks and total attributable mortalities during the summer period were predicted for mid-century (2053-2057) and end-century (2093-2097) under various SSP climate scenarios. Daily maximum temperatures were correlated with daily deaths using a distributed lag non-linear model to estimate relative risks. Future temperatures were projected using recent climate models (CMIP6-GCM), with an average taken from eight models using a multi-model ensemble approach. Statistical downscaling and calibration with observation data were applied, with quantile delta mapping (QDM) providing the most accurate bias-correction. Compared to the reference period, average extreme temperatures in summer months (June-July-August) are expected to remain almost constant (34 degrees C) until mid-century (over the entire period 2015-2050), while end-of-century extreme temperatures are projected to increase by 1.2 degrees C (-0.4-3.4 degrees C) under SSP1-1.9 and 6.6 degrees C (3.1-11 degrees C) under SSP5-8.5. Future attributable mortality rates in summer are projected to rise by 15.6% (95% CI: 0.4-37.2%) in 2053-57 and 38.0% (95% CI: 3.7-63.3%) in 2093-97 under SSP5-8.5. Achieving T & uuml;rkiye's net zero emission target by 2053 (SSP1-1.9) and implementing adaptive policies could reduce the expected attributable deaths for summer months in & Idot;stanbul by 39.7%, from 15,732 mid-century to 9,482 by end-century. By recognising these risks, policymakers can more effectively anticipate and mitigate the impacts of extreme heat on urban populations.Graphical Abstract To address the predicted impacts of climate change, T & uuml;rkiye has implemented several climate action initiatives, including Climate Change Adaptation Strategy and Action Plan (2024-2030), Climate Change Mitigation Strategy and Action Plan (2024-2030), & Idot;stanbul Climate Change Action Plan, and a national commitment to achieving net-zero greenhouse gas emissions by 2053. The impact of rising temperatures on mortality risks in & Idot;stanbul is examined in this study by using the latest climate projections, CMIP6-GCM models and SSP scenarios. A health impact model is employed using distributed lag non-linear models (DLNM) to estimate attributable mortality rates when temperatures exceed the minimum mortality threshold. Findings indicate that the maximum daily temperatures are expected to rise significantly under different climate scenarios, especially with the highest emissions pathway (SSP5-8.5) resulting in the most extreme warming. Compared to the historical (1980-2014) period, extreme temperatures at the end-of-century are projected to increase by 1.2 degrees C (-0.4-3.4 degrees C) under SSP1-1.9 and 6.6 degrees C (3.1-11 degrees C) under SSP5-8.5. During the reference period, 4,009 deaths in & Idot;stanbul were linked to extreme heat. By the end of the century, projections estimate 9,482 deaths under the optimistic SSP1-1.9 scenario and 39,779 under the pessimistic SSP5-8.5. Achieving net-zero emissions by 2053 could reduce mid-century deaths from 15,732 to 9,482 by 2100- a 39.7% decline. However, even under SSP1-1.9, the mortality rate is projected to increase by 4. 5% compared to 2013-2017 due to population growth. Therefore, while emission reductions are essential, adaptation strategies, such as managing urban populations and strengthening climate resilience of the cities, are equally vital to protect public health.https://doi.org/10.1007/s41748-025-00707-xhttps://hdl.handle.net/20.500.12831/2689