Istanbul Technical University
Ulusal Üniversitelerarası Açık Erişim Sistemi - İstanbul Teknik ÜniversitesiNot a member yet
67356 research outputs found
Sort by
ENHANCING SEISMIC STRUCTURAL DAMAGE ASSESSMENT OF LOW-TO-MEDIUM RISE REINFORCED CONCRETE FRAMED BUILDINGS USING ARTIFICIAL INTELLIGENCE
No full texthttps://doi.org/10.2495/eres25003
Analysis Reliable and Link Stability-Based Energy-Aware Multipath Routing for Mobile Ad Hoc Networks Under Random Waypoint Mobility
No full texthttps://doi.org/10.1007/978-981-97-8160-7_2
Assessing sustainability and resilience of three dairy value chaines in Southern Mediterrenean countries
No full texthttps://hal.science/hal-05263238v
The Effect of TRIM Function on Data Recovery from SSD Solid-State Drives
No full text<title>Abstract</title> <p>The need for developing computer forensics has emerged due to the growing number of crimes involving advanced digital systems for unauthorized access. In this regard, digital forensics will always be an advanced field as court cases involving computer technology become more widespread. This research paper presents a detailed study of the fundamental method of using SSD drives for computer forensics. Solid-state drives (SSDs) have replaced traditional spinning disk hard drives and have become the standard for storing data in devices. Today, SSD drives are widely used in desktop computers and laptops. SDDs use flash memory therefore they are highly reliable. This study analyzes the allocated and unallocated storage space on SSD with the TRIM function. One of the key problems is the built-in SSD data self-destruction mechanism, which makes it difficult to recover deleted files. In this research paper, we will consider a method that could reduce the impact of all the features described. The result of the study may contribute to the development of more reliable tools in forensic investigations.</p>https://doi.org/10.21203/rs.3.rs-7419937/v
Blood-based non-Newtonian ternary nanofluid flow in converging/diverging channels embedded in a non-Darcy porous medium with slip and jump effects
No full textPurpose Nanoparticles are well-suited for targeted drug delivery and thermal cancer therapy due to their high surface area in proportion to their volume. Blood acts like a Newtonian fluid at high shear rates, whereas it exhibits non-Newtonian behavior at low shear rates. In addition, ternary hybrid nanofluids (THNFs) can have enhanced thermophysical properties over single and two-particle nanofluids because of their combined effects. Based on this knowledge, the purpose of this study is to examine the flow of blood-based second-grade THNF in converging/diverging channels, considering slip-velocity and temperature jump effects. Design/methodology/approach Governing nonlinear partial differential equations for continuity, momentum and energy were transformed to ordinary differential equations (ODEs) using similarity variables, and these ODEs are solved numerically with MATLAB’s bvp4c function. The accuracy of the numerical solution is validated by comparing results with established literature, showing close agreement. Findings The influence of various parameters on velocity and temperature profiles, as well as on engineering parameters, is investigated. The Darcy and Forchheimer parameters, which are in the range of 0–2, demonstrate an inverse relationship in converging and diverging channels. Higher Darcy and inertial parameters improve skin friction and heat transfer in the diverging channel but decrease them in the converging channel. When the Deborah number ranges from 0 to 0.3, the non-Newtonian fluid’s elastic properties generate a 3% velocity field difference. Nanoparticle shape factor and volume fraction play vital roles in optimizing heat transfer. Research limitations/implications The results of this study could be valuable in engineering applications that investigate the effect of nanofluids in blood vessels. Originality/value The key innovation of this study includes the investigation of blood-based THNF flow in converging/diverging channels embedded in a non-Darcy porous medium across different vessel sizes by using a non-Newtonian model.https://doi.org/10.1108/hff-04-2025-026
Circular Built Environment During the Digital Age: A Systematic Review
No full textAs the effects of the Industrial Revolution have significantly contributed to global climate change and the studies reveal that by 2050, the world's energy demand will double while fossil fuel reserves are projected to deplete. To mitigate the risks associated with exceeding the 1.5°C global warming threshold, international organizations, including the United Nations, as well as governments and NGOs, are implementing strategies aimed at achieving carbon neutrality by mid-century. One such approach involves transitioning from the "take-make-waste" model of the linear economy to the circular economy (CE), which operates on principles of "make-use-reuse-recycle." The AECO (Architecture-Construction-Engineering-Operation) industry, a key driver of global economic activity, plays a central role in this transformation by rethinking and restructuring the AECO industry to align with CE principles. This study examines the intersection of circular economy principles and the built environment through the lens of Industry 4.0. A systematic literature review combining descriptive and bibliometric analysis, covering publications from 2016 to 2024 from Scopus and Web of Science (WoS), was conducted using keywords related to CE, the built environment, and digital technologies. The analysis, performed with VOSviewer, highlights key trends, thematic connections, and potential areas for future research. Digital technologies such as building information modeling (BIM), blockchain, and the Internet of Things (IoT) have emerged as powerful tools to support CE implementation. By enabling resource optimization, reducing waste, and enhancing lifecycle assessments, these technologies facilitate the adoption of sustainable practices within the AECO sector. These studies underscore the importance of advancing frameworks like life cycle assessment (LCA) and cradle-to-cradle (C2C) to support circular transitions in the built environment. Furthermore, the results demonstrate the increasing momentum and global interest in leveraging digitalization to achieve sustainability goals in the sector. This study offers valuable insights for academics, industry professionals, and policymakers by mapping the current state of CE research in the AECO industry and identifying emerging trends. It emphasizes the need for comprehensive frameworks and strategic roadmaps to enable the circular transition of the AECO sector. Future research should focus on deepening interdisciplinary collaboration and integrating CE with related sustainability concepts to enhance understanding and accelerate implementation. By doing so, the AECO industry can make significant contributions toward global carbon neutrality and sustainable development goals.https://doi.org/10.53710/jcode.161853
Modeling Soil Behavior with Machine Learning: Static and Cyclic Properties of High Plasticity Clays Treated with Lime and Fly Ash
No full textSoils may not always be suitable to fulfill their intended function. Soil improvement can be achieved by mechanical or chemical methods, especially in transportation facilities. L and FA additives are frequently used as chemical improvement additives. In this study, two natural clay samples with extreme and very high plasticity were improved by using L and FA admixtures, and their properties under static and repeated loads were investigated by ML methods. Two soil samples from two different sites were analyzed. In this study, eight datasets were used. There are 14 inputs, including specific gravity (Gs), void ratio (eo), sieve analysis (+No.4, −No.200), clay size, LL, plastic limit (PL), plasticity index (PI), linear shrinkage (Ls), shrinkage limit (SL), cure day, agent, clay type, and agent percentage. The outputs are index and swelling properties (compressive, percent), compressive strengths, modulus of elasticity, and compressibility properties in soaked and non-soaked conditions. Prediction is attempted with different ML (ML) techniques. ML techniques used for regression (such as Decision Tree Regression (DTR) and K-nearest neighbors (KNN)). SHapley Additive Explanations (SHAP), the impact of inputs on outputs were observed, and it was generally found that PL and LL had the highest impact on outputs. Different performance metrics are used for evaluation. The results showed that these ML techniques can predict the static and cyclic properties of extremely high plasticity clays with high performance (R2 &gt; 0.99). These results highlight the general applicability of the used ML models on different datasets containing soil properties.https://doi.org/10.3390/buildings15020288https://doaj.org/article/f8bdcb1191fe405487eb0df69eb3b090https://hdl.handle.net/20.500.12831/2427
Fibrin Scaffold With Concentrated Growth Factor and Stromal Vascular Fraction: A Novel Approach for Repairing Chronic Rotator Cuff Tears in a Rabbit Model
No full textBackground: Rotator cuff tears (RCTs) represent a significant challenge in orthopaedic care, particularly in chronic cases where tendon healing is suboptimal. Novel biological therapies such as concentrated growth factor (CGF) and stromal vascular fraction (SVF) offer promising solutions for enhanced tendon repair. Hypothesis: This study hypothesized that a fibrin scaffold enriched with CGF and SVF would improve tendon healing by reducing fatty degeneration, increasing vascularization, and enhancing biomechanical properties in a chronic RCT rabbit model. Study Design: Controlled laboratory study. Methods: A chronic RCT model was developed in the subscapularis tendon of 28 male New Zealand rabbits. In the first phase (week 0), the chronic injury model was created surgically. At week 6, in addition to the transosseous repair technique, biological materials were applied into the bone tunnel in each group as follows: hydrogel (group 1), fibrin gel with CGF (group 2), CGF+SVF–enriched fibrin scaffold (group 3), and no repair (group 4). At week 12, animals were euthanized, and samples were collected for macroscopic, histological, immunohistochemical, and biomechanical analysis. Results: Group 3 demonstrated a superior result. Fatty degeneration was significantly lower in group 3 compared with group 1 ( P = .045). Vascularization and cellularity scores were highest in group 3 (3.7 ± 0.5 and 3.6 ± 0.5, respectively), significantly greater than group 1 (1.4 ± 0.5 and 1.3 ± 0.5, respectively) ( P = .024 and P = .004, respectively). Collagen fiber continuity and regularity scores were 3.7 ± 0.5 and 3.6 ± 0.5 in group 3, respectively, significantly better than group 1 (1.4 ± 0.5 and 1.3 ± 0.5, respectively) ( P = .006 and P = .003, respectively). Biomechanical testing revealed the highest tensile strength in group 3 (116.14 ± 8.49 N; P &lt; .001). Midsubstance tears, indicating robust healing, were observed in 85.7% of tendons in group 3 compared with 28.6% in group 1 ( P = .002). Notably, group 3 also demonstrated superior outcomes compared with group 2, with significantly greater tensile strength (116.14 ± 8.49 N vs 100 ± 6.85 N; P &lt; .001) and improved histological parameters including reduced fatty degeneration, and increased vascularization and collagen fiber regularity. Conclusion: The inclusion of CGF and SVF in fibrin scaffolds significantly enhances tendon healing in chronic RCTs, outperforming the use of CGF alone. This combined biological approach offers a promising therapeutic strategy to optimize tendon repair outcomes. Clinical Relevance: These findings support the clinical potential of CGF and SVF in improving repair outcomes in chronic RCT cases in sports medicine.https://doi.org/10.1177/23259671251366686https://pmc.ncbi.nlm.nih.gov/articles/PMC12495194/https://pubmed.ncbi.nlm.nih.gov/41049598
8 Aralık 2024 Güngören, Arhavi (Artvin) Moloz Çığının Oluşum Dinamiği ve Alanın Heyelan Tehlike ve Risk Bakımından Değerlendirmesi
No full texthttps://dx.doi.org/10.5281/zenodo.14625940https://dx.doi.org/10.5281/zenodo.1462593
Effects of cold-pressed oil additives in varying proportions: Physico-chemical characteristics of mayonnaises
No full textThis study evaluated the effects of incorporating cold-pressed sesame (C-SEO), safflower (C-SAO), and black cumin oils (C-BCO) into mayonnaise at substitution ratios of 0-20 % to sunflower oil. Refined sunflower oil had the lowest free fatty acids (FFA) and strong antiradical activity due to high α-tocopherol and β-carotene content. C-BCO showed the highest oxidation levels with a peroxide value of 6.52 meq O₂/kg. Increasing cold-pressed oil proportions improved the mayonnaise's total phenolic content and antiradical activity, with values ranging from 12.07 to 13.26 mg GAE/100 g and 0.56 % to 4.08 %, respectively. SAM (safflower oil mayonnaise) displayed the greatest color change, while cold-pressed sesame oil exhibited the best lipid oxidation stability. Sensory evaluation scores varied from 5.8 to 7.4, with SAM having the highest acceptability. All mayonnaises maintained good emulsion stability and microbiological safety after 6 months at 4 °C. The findings suggest that cold-pressed oils enhance mayonnaise's bioactive content, stability, and quality.https://doi.org/10.1016/j.foodchem.2024.142576https://pubmed.ncbi.nlm.nih.gov/3972470