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Comparison of Thermophysical Property Models of Nanofluids for Thermal Performance in a Microchannel
No full textDifferent thermophysical property models for nanofluids and several dimensionless parameters have been compared in the case of heat transfer for laminar flow in a microchannel. Addition of nanoparticles, including Al2 O3, CuO, and TiO2, to water has been considered for volumetric concentrations up to ϕ = 7%. The numerical analyses have been conducted via the finite difference method for a transient regime. The heat transfer results have been obtained in terms of the interfacial heat flux, bulk temperature, and the Nusselt number. The parametrical effects of Péclet number values, wall thickness ratios, thermal diffusivity ratios, thermal conductivity ratios, and Brinkman number values have been evaluated. Based on the results, the influence of axial conduction has been clearly observed for lower Péclet numbers. Furthermore, the increment of the thermal conductivity ratio and the decrement of the wall thickness ratio have enhanced thermal performance. Nevertheless, the thermal characteristics have not been significantly influenced by the thermal diffusivity ratio. The viscous dissipation has altered the heat transfer direction due to the change in the Brinkman number. The required time to reach the steady state for numerical solution increased because of decreasing Brinkman number values. Heat transfer augmentation has been obviously obtained due to ascending nanofluid volumetric concentrations. The CuO nanoparticles have been recommended owing to their higher thermal performance for the fixed volumetric concentration. According to the thermophysical models compared for each type of nanoparticles, the models for Al2 O3 nanoparticles presented the closest results to each other. Nonetheless, it has been observed that one model for CuO nanoparticles and one model for TiO2 nanoparticles are inadequate. © 2025 by Begell House, Inc.Konya Teknik Üniversitesi, KTÜN, (2018-OYP-046
A Survey on Mitigation of Cache Pollution Attacks in NDN
No full textNamed Data Networking (NDN) improves data retrieval by using in-network caching, but this advantage makes it susceptible to cache pollution attacks, where malicious or irrelevant content fills caches and reduces network efficiency. This paper reviews several mitigation techniques for these attacks, grouping them into proactive, reactive, and collaborative approaches. Each strategy is assessed based on its scalability, detection accuracy, and overall impact on network performance. While some progress has been made, existing methods often struggle in large, dynamic environments, where they tend to be computationally expensive and lack adaptability. The survey identifies key research gaps, such as the need for real-time, adaptive solutions that can operate without compromising network performance. It also highlights the potential for using AI and machine learning to enhance detection accuracy and reduce false positives. Future research should focus on developing scalable, decentralized systems to strengthen the security and efficiency of NDN’s caching mechanisms. © 2025, Szechenyi Istvan University. All rights reserved
Geochemical and Mineralogical Properties of Karst Types Bauxite, Catkoy, Taurus Mountains, Turkey
No full textIn recent years, studies on the geochemical, mineralogical properties and ore types of bauxite have become a significant area of research. The study area is situated within the boundaries of Catkoy within the Taurus Mountains region. The aim of this study is to determine the mineralogical and petrographic properties of bauxites and to classify bauxite ores based on macro observations. It also aims to determine the parent material of bauxite ores by analyzing the geochemical properties of bauxite, terra rossa, and the adjacent rocks. The samples were subjected to chemical analysis using inductively coupled plasma-mass spectrometry and mineralogical investigation using X-ray diffraction and microscopic techniques. The bauxite is composed of varying proportions of diaspore, hematite, and clay minerals. The ore paragenesis study has been observed to comprise diaspore, hematite, kaolinite, anatase, rutile, sphene, calcite, muscovite, magnetite, quartz, goethite, chlorite, amorphous iron- and aluminum-hydroxide, gibbsite, boehmite, illite, specularite, epidote, chalcedony, amphibole, and psilomelane. The internal composition of bauxite allows for the identification of distinct ore types, characterized by varying appearances. The ore types under consideration are black bauxite, brown bauxite, oolitic bauxite and clay bauxite. The chemical composition of bauxites is typically 54% Al2O3, 26% Fe2O3, 5% SiO2, 3% TiO2 and less than 1% other major oxides. The modulus values of these bauxites exhibit a range of 1.4-91.2, with an average of 34.66. It is therefore concluded that they are of first quality. The geochemical data lend support to the hypothesis that limestone was transformed into terra rossa, which in turn was transformed into bauxite. It is believed that bauxite ores were formed before metamorphism and continued to be formed for a long time after metamorphism. Bauxites were formed during the Late Triassic to Early Jurassic interval on Upper Permian-aged carbonate rocks and Lower Triassic-aged shale, sandstone, and limestone units. Subsequently, they were deposited in caves and dolines within the carbonate rocks.This paper is dedicated to the memory of Prof. Dr. Sedat Temur. Financial support for this research was provided by the Scientific Research Projects Coordination Unit (BAP, FEB 2004/06) of Omer Halisdemir University (Nigde), Akdeniz University (Antalya) and the Scientific Committee of the Ministry of Science and Higher Edu-cation of the Republic of Kazakhstan (Grant No. AP15473611). The authors are grateful for the support. We would like to express our sincere thanks Dr Gursel Kansun for their valuable opinions.Scientific Research Projects Coordination Unit (BAP) [FEB 2004/06]; Akdeniz University (Antalya); Scientific Committee of the Ministry of Science and Higher Edu-cation of the Republic of Kazakhstan [AP15473611
Differential Cross Section Measurements for the Production of Top Quark Pairs and of Additional Jets Using Dilepton Events From Pp Collisions at S = 13 Tev
No full textDifferential cross sections for top quark pair (tt¯) production are measured in proton-proton collisions at a center-of-mass energy of 13 TeV using a sample of events containing two oppositely charged leptons. The data were recorded with the CMS detector at the CERN Large Hadron Collider and correspond to an integrated luminosity of 138 fb−1. The differential cross sections are measured as functions of kinematic observables of the tt¯ system, the top quark and antiquark and their decay products, as well as of the number of additional jets in the event. The results are presented as functions of up to three variables and are corrected to the parton and particle levels. When compared to standard model predictions based on quantum chromodynamics at different levels of accuracy, it is found that the calculations do not always describe the observed data. The deviations are found to be largest for the multi-differential cross sections. © The Author(s) 2025.Council of Scientific and Industrial Research, India, CSIR; Ministry of Business, Innovation and Employment, MBIE; Ministry of Education and Science, MES; Benemérita Universidad Autónoma de Puebla, BUAP; Center for African Studies, CAS; Department of Atomic Energy, Government of India, DAE; PCTI; National Academy of Sciences of Ukraine, NASU; Welch Foundation; National Science and Technology Development Agency, NSTDA; Fundamental Research Funds for the Central Universities; MSES; Ministry of Education of the People's Republic of China, MOE; Narodowe Centrum Nauki, NCN; National Science Foundation, NSF; Missouri University of Science and Technology, MST; Institut National de Physique Nucléaire et de Physique des Particules, IN2P3; Latvijas Zinātnes Padome; Science and Technology Facilities Council, STFC; F.R.S.-FNRS; Council of Science and Industrial Research; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CINVESTAV; Ministério da Educação e Ciência, MEC; MEYS; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, FAPERJ; Ministerio de Ciencia e Innovación, MCIN; Universiti Malaya, UM; Bundesministerium für Bildung, Wissenschaft und Forschung, BMBWF; Hellenic Foundation for Research and Innovation, HFRI; National Science Council, NSC; Ministry of Science,Technology and Research, MoSTR; Hispanics in Philanthropy, HIP; Hungarian Academy of Sciences; Secretaría de Educación Pública, SEP; Austrian Science Fund, FWF; Department of Science and Technology, Ministry of Science and Technology, India, DST; Chulalongkorn Academic; Consejo Nacional de Humanidades, Ciencias y Tecnologías; Belgian Federal Science Policy Office, BELSPO; ERDF; Centre National de la Recherche Scientifique, CNRS; Bundesministerium für Bildung und Forschung, BMBF; Fonds Wetenschappelijk Onderzoek, FWO; Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TUBITAK; Beijing Municipal Science ; Technology Commission; Kavli Foundation; Research Council of Finland, AKA; Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq; Pakistan Atomic Energy Commission, PAEC; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES; California Earthquake Authority, CEA; Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu, TENMAK; Nvidia Corporation; Hellenic Foundation for Research and Innovation; Belgian Federal Science Policy Office; Deutsche Forschungsgemeinschaft, DFG; Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH; Qatar National Research Fund; LNS; Alfred P. Sloan Foundation; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, MPNTR; Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture; Science Foundation Ireland, SFI; U.S. Department of Energy, USDOE; COST; International Council of Shopping Centers, ICSC; Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP; Cosmetic Surgery Foundation, CSF; Fundação para a Ciência e a Tecnologia; Agencia Estatal de Investigación, AEI; ICSC; FRIA-Belgium; Ministry of Education, Youth and Sports; Ministry of Science and Technology of the People's Republic of China, MOST; Programa Severo Ochoa del Principado de Asturias; General Secretariat for Research and Innovation, GSRI; Bulgarian National Science Fund, BNSF; Latvian Council of Science; Hugh Green Foundation, HGF; Ministerio de Ciencia, Tecnología e Innovación; Alfred P. Sloan Foundation, APSF; Emory University, EU; EU; Maryland Ornithological Society, MOS; Ministry of Higher Education, Science, Research and Innovation, Thailand, MHESI; Fonds De La Recherche Scientifique - FNRS, FNRS; Agentschap voor Innovatie door Wetenschap en Technologie; Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, FAPERGS; Weston Havens Foundation; Shota Rustaveli National Science Foundation, SRNSF; Institute for Research in Fundamental Sciences, IPM; Leventis Foundation; A.G. Leventis Foundation; European Research Council, ERC; Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture, FRIA; Swiss Funding Agencies; European Regional Development Fund, ЕФРР; European Research Council; Nvidia; CERN, CERN; Louisiana Academy of Sciences, LAS; Ministerstvo Školství, Mládeže a Tělovýchovy, MSMT; National Retail Federation, NRF; Ministry of Science ICT and Future Planning, MSIP; Secretaría de Educación Superior, Ciencia, Tecnología e Innovación, SENESCYT; Fundamental Research Funds for the Central Universities; Alexander von Humboldt-Stiftung, AvH; Istituto Nazionale di Fisica Nucleare, INFN; Weston Havens Foundation; Agentschap voor Innovatie door Wetenschap en Technologie, IWT; Universidad Autónoma de San Luis Potosí, UASLP; National Natural Science Foundation of China, NSFC; Kavli Foundation; IWT-Belgium; Horizon 2020; Welch Foundation, (C-1845); Fundação para a Ciência e a Tecnologia, FCT, (CEECIND/01334/2018); Fundação para a Ciência e a Tecnologia, FCT; Excellence of Science, (30820817); Qatar National Research Fund, QNRF, (MCIN/AEI/10.13039/501100011033); Qatar National Research Fund, QNRF; National Science, Research and Innovation Fund, (B37G660013); Shota Rustaveli National Science Foundation, (FR-22-985); Deutsche Forschungsgemeinschaft, (400140256 — GRK2497, 390833306); Ministry of Education and Science, (2022/WK/14); Beijing Municipal Science and Technology Commission, Adminitrative Commission of Zhongguancun Science Park, (Z191100007219010); Beijing Municipal Science and Technology Commission, Adminitrative Commission of Zhongguancun Science Park; National Science Center, (2021/43/B/ST2/01552, 2021/41/B/ST2/01369); Engineering Research Centers, ERC, (TK202); Engineering Research Centers, ERC; Alexander von Humboldt Foundation, (22rl-037); Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, (MDM-2017-0765); Magyar Tudományos Akadémia, MTA, (K 143460, TKP2021-NKTA-64, K 124845, K 124850, K 138136, K 128786, 2020-2.2.1-ED-2021-00181, K 143477, K 129058, K 131991, K 133046, K 128713); Magyar Tudományos Akadémia, MTA; Horizon 2020, (752730, 765710, 758316, 724704, 824093, 675440); Horizon 2020; European Cooperation in Science and Technology, COST, (CA16108); European Cooperation in Science and Technology, COS
Consideration of Aspect Ratios on Flow Around Wall-Mounted Square Cylinders
No full textFlow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re = 10 000. Four turbulence models have been compared in terms of drag coefficient (CD). The closest result has been provided by two turbulence models, namely, k − ε Realizable and k − ω Shear Stress Transport (SST). Hence, these models were utilized to present the flow patterns of pressure distributions, turbulent kinetic energy values, velocity magnitude values with streamlines, streamwise velocity components, cross-stream velocity components and spanwise velocity components on different planes. Flow stagnation has been attained in front of the cylinder. Pressure values peaked for the upstream region. Over the cylinders, the tip vortex structure was dominant owing to the influence of the free end. Flow separation from the top front edge of the body has been obtained. The dividing streamline affected by the flow separation was highly effective in the wake region and moved nearer to the body when the aspect ratio was decreased; the reason was the wake shrinkage owing to the decreasing aspect ratio. Upwash and downwash have been seen in the cylinder wake. These two models presented similar flow patterns and drag coefficients. These drag coefficients are in good agreement with those in previous studies. © Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Investigation of the Strength of Reinforced Masonry Walls Under the Effect of Earthquake Using Geogrid
No full textIn this study, the investigation focuses on enhancing the structural integrity of brick wall samples by incorporating geogrid materials of varying strengths. The collapse and shear strengths under horizontal loads were examined in planes, and the results were compared. A comparative analysis has been conducted to evaluate the use of both uniaxial and biaxial geogrid as confinement reinforcement on the surfaces of brick masonry specimens. To draw a comparison, unreinforced masonry walls, masonry walls completely reinforced with uniaxial geogrid material, and masonry wall samples fully reinforced with biaxial geogrid material were created. Moreover, 12 experiments have been carried out, in which the standard slip stress experiment technique recommended by ASTM 1391-81 for masonry wall samples was used. The observed behaviors in the experimental samples including formed cracks, horizontal load-displacement graphs, and energy absorption capacities were compared. The achieved result showed that the masonry wall reinforced with biaxial geogrid material showed a 10% higher load capacity than the unreinforced masonry wall
An Adaptive and Hybrid State of Charge Estimation Method Integrating Sequence-To Learning and Coulomb Counting for Li-Ion Based Energy Storage Systems
No full textFor safe and long-lasting operation of Li-ion batteries used in electric vehicles and electric grid applications, the State of Charge (SOC) of the battery cell must be estimated with high accuracy. However, due to the uncertainty in environmental conditions and the complex nature of battery chemistry, SOC estimation still presents a significant challenge. In this study, an adaptive and hybrid method for SOC estimation of a Li-ion battery cell is proposed. Convolutional Neural Network (CNN) based Sequence-to-point learning architecture is used to estimate the initial SOC values at specific time intervals. In order to increase the estimation accuracy, a multi-scale CNN architecture is designed, and useful features are captured. The obtained estimation values are integrated with the partial coulomb counting method to increase the accuracy. In addition, the proposed model adaptively updates the estimation weights with the help of the estimation error data obtained during the full charging of the batteries. The proposed model is tested on the LG 18650HG2 dataset. The results prove that the proposed model is 23% more accurate than benchmark models at 25°C and 55.5% more accurate at 0°C
The Impact of Parental Attitudes on Academic Performance and Obesity of Elementary School Students
No full textThis study aims to examine the impact of parental attitudes on school achievement and obesity among 3rd and 4th-grade primary school students. The sample consisted of 541 students-312 girls and 229 boys-aged between 8 and 12 years, enrolled in 3rd and 4th grades at primary schools in the Sel ; ccedil;uklu, Karatay, and Meram districts of Konya. To assess the students' obesity status, height and weight measurements were taken, and the body mass index (BMI) was calculated. Parental attitudes were analyzed across four sub-dimensions: democratic, protective, authoritarian, and permissive. The data were analyzed by Chi-square, Independent sample T-test, One-way Anova, Person Correlation, and Multiple regression analysis. As a result of the study, it was observed that overprotective parental attitudes decreased as parental education increased. In addition, it is seen that the risk of obesity in children whose fathers are obese increases significantly. As the father's weight increases, the likelihood of the child being obese also increases. As the democratic attitude scores of the parents increase, their perceptions of their children's success status increase, and as the authoritarian and permissive attitude scores increase, their perceptions of their children's success status decrease. A significant relationship was found between authoritarian attitude and obesity, and authoritarian attitude was found to be higher in families of obese children. As a result of regression analysis, it was found that an authoritarian attitude increased obesity and decreased school success, while a democratic attitude increased school success
Enhancing Structural Health Monitoring of Fiber-Reinforced Polymer Composites Using Piezoresistive Ti3c2tx Mxene Fibers
No full textThe anisotropic behavior of fiber-reinforced polymer composites, coupled with their susceptibility to various failure modes, poses challenges for their structural health monitoring (SHM) during service life. To address this, non-destructive testing techniques have been employed, but they often suffer from drawbacks such as high costs and suboptimal resolutions. Moreover, routine inspections fail to disclose incidents or failures occurring between successive assessments. As a result, there is a growing emphasis on SHM methods that enable continuous monitoring without grounding the aircraft. Our research focuses on advancing aerospace SHM through the utilization of piezoresistive MXene fibers. MXene, characterized by its 2D nanofiber architecture and exceptional properties, offers unique advantages for strain sensing applications. We successfully fabricate piezoresistive MXene fibers using wet spinning and integrate them into carbon fiber-reinforced epoxy laminates for in-situ strain sensing. Unlike previous studies focused on high strain levels, we adjust the strain levels to be comparable to those encountered in practical aerospace applications. Our results demonstrate remarkable sensitivity of MXene fibers within low strain ranges, with a maximum sensitivity of 0.9 at 0.13% strain. Additionally, MXene fibers exhibited high reliability for repetitive tensile deformations and low-velocity impact loading scenarios. This research contributes to the development of self-sensing composites, offering enhanced capabilities for early detection of damage and defects in aerospace structures, thereby improving safety and reducing maintenance expenses. © The Author(s) 2025.European Cooperation in Science and Technology, COST; Çanakkale Onsekiz Mart Üniversitesi, ÇOMÜ, (FBA-2020-3464, 221M523); European Commission, EC, (101079250
Dye-Sensitized Sepiolite Clay as Natural Scaffolds for Visible Light Driven Photocatalytic Hydrogen Evolution
No full textNatural clay minerals are increasingly used as superior support materials for various photocatalysts due to their excellent adsorption capacity, negative surface charge, suitable thermal/chemical stability, large specific surface area, and strong surface reactivity, resulting in low agglomeration and suppression of charge recombination. However, they are still insufficient for photocatalysis due to their low efficiency. Therefore, sensitization of clay minerals with dyes to improve the efficiency and specificity of catalysts is considered a promising route for photocatalytic applications. In this work, the effect of dye sensitization on visible light-driven photocatalytic water splitting of microfibrous sepiolite scaffolds as natural photocatalyst supports was investigated for the first time by using various xanthene dyes (eosin Y, rhodamine B and eryhtrosine B (ErB)) and triethanolamine as photosensitizers and sacrificial agents, respectively, in the absence and presence of platinum as a co-catalyst. The clay/dye system was characterized using various techniques such as X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and energy dispersive X-rays. Sep/ErB photocatalysts produced the highest amount of hydrogen among the other Sep/dye scaffold systems because they act as an effective matrix by preventing nanoparticle aggregation and promoting electron transfer due to their excellent crystal structures and physicochemical properties.EU [952289]Selcuk University [20401033]This work is supported by both Selcuk University (Grant number: 20401033) and EU Horizon 2020 (EngSurf-Twin (Grant Number: 952289) ) projects