WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 2Citation - Scopus: 1Çelik Fiber Katkısının Farklı Boyuna Donatı Oranına Sahip Betonarme Döşemelerin Zımbalama Davranışı Üzerinde Etkileri(2019) Saatci, Selcuk; Yasayanlar, Suleyman; Yasayanlar, Yonca; Batarlar, BaturaySunulan çalışmada her iki yönde birbirine dik 0,004 (D1 serisi) ve 0,002 (D2 serisi) oranında boyuna donatıiçeren 2150x2150x150 mm boyutlarında iki grup betonarme döşeme, hacimce %0, %0,5, %1 ve %1,5oranında çelik fiber katkısı içeren beton karışımlarıyla dökülmüştür. Üretilen toplam sekiz döşeme ortanoktalarından statik yük altında test edilmişlerdir. Çelik fiber katkısı olmayan numunelerde yüksek boyunadonatı oranına sahip döşeme boyuna donatısında akma gerçekleşmeden gevrek bir şekilde zımbalamagöçmesi oluşurken düşük boyuna donatı oranına sahip döşeme zımbalama gerçekleşmeden önce çok dahasünek bir davranış göstermiştir. Çelik fiber katkısı her iki boyuna donatı oranında da iki kata varan oranlardazımbalama dayanımı artışlarına sebep olmuştur. Ancak D1 serisi döşemelerde çelik fiber katkısı maksimumyer değiştirmeleri önemli ölçüde arttırırken D2 serisinde maksimum yer değiştirmelerde önemli bir farkoluşmamış, bu döşemelerin yer değiştirmesi boyuna donatının akması tarafından kontrol edilmiştir. Çelikfiber katkısı oranının arttırılması D1 serisi döşemelerde dayanımın ve maksimum yer değiştirmelerinartmasına sebep olurken, D2 serisi döşemelerde %1'in üstü çelik fiber katkı oranları davranışta önemli birfark oluşturmamıştır. Yapılan deneyler Kritik Kesme Çatlağı Teorisi kullanılarak analitik olarakmodellenmiş ve bu tip modelleme ile ilgili bazı iyileştirmeler önerilmiştir.Article Deposition of (La,Sr)CoO₃-δ and (La,Sr)₂CoO₄-δ Cathode Layers on Gadolinia-Doped Ceria by Electrospray Deposition(Springer, 2025) Ergen, Emre; Akkurt, SedatLa-, Sr-, and Co-based oxides have proven their performances in the cathode layers of intermediate temperature levels of solid oxide fuel cells (SOFC), and hence have been frequently studied. They are deposited on the electrolyte layer by chemical vapor deposition (CVD), screen printing, pulsed laser deposition (PLD), etc. The electrospray deposition (ESD) proved itself as an effective and facile method for cathode deposition. Cathode layers deposited on gadolinia-doped ceria (GDC) with the compositions of (La0.5Sr0.5)CoO3, (La0.8Sr0.2)CoO3, (La0.5Sr0.5)2CoO4, and (La0.8Sr0.2)2CoO4 are known to provide low resistance values which are critical in cell performance. In this study, ESD is used for the first time as the coating method of these compositions. Area-specific resistance (ASR) measurements made by electrochemical impedance spectroscopy (EIS) showed promising results. Particularly, the sample coated in (La0.5Sr0.5)CoO3 composition showed an ASR value of 0.11 Omega.cm2 at 700 degrees C. ESD showed the ability to control the cathode coating microstructure by controlling the spraying parameters.Article Citation - WoS: 7Projektiranje Nasipa Zeljezničkih Pruga Primjenom Neuronskih Mreža(Croatian Soc Civil Engineers-hsgi, 2013) Tayfur, Gokmen; Egeli, IsfendiyarThe main requirement in the design of high-speed railway embankments are low values of total differential settlements. The use of cement stabilized layers in embankments, as compared to non-stabilized layers that are now most often in use, is analysed in the paper. Different cement proportions and different water/cement ratios for stabilized layers are considered. It was established that the use of cement stabilized layers in embankments can greatly reduce thickness of individual layers, while also reducing settlement. The research was conducted using the feed forward neural network.Article Projectivity and Quasi-Projectivity With Respect To Epimorphisms To Simple Modules(World Scientific Publ Co Pte Ltd, 2025) Alagoz, Yusuf; Alizade, Rafail; Buyukasik, EnginUsing the notion of relative max-projectivity, max-projectivity domain of a module is investigated. Such a domain includes the class of all modules whose maximal submodules are direct summands (this class denoted as MDMod -R). We call a module max-p-poor if its max-projectivity domain is exactly the class MDMod -R. We establish the existence of max-p-poor modules over any ring. Furthermore, we study commutative rings whose simple modules are projective or max-p-poor. Additionally, we determine the right Noetherian rings for which all right modules are projective or p-poor. Max-p-poor abelian groups are fully characterized and shown to coincide precisely with p-poor abelian groups. We also further investigate modules that are max-projective relative to themselves, which are known as simple-quasi-projective modules. Several properties of these modules are provided, and the structure of certain classes of simple-quasi-projective modules is determined over specific commutative rings including the ring of integers and valuation domains.Article Citation - WoS: 1Citation - Scopus: 1Microporous Carbon Spheres for the Enrichment of Lead From Water Samples With Determination by Microsample Injection System - Flame Atomic Absorption Spectrometry (MIS-FAAS)(Taylor & Francis inc, 2025) Njjar, Muath; Ugan, Muhammet; Akturk, Ezgi Zekiye; Pelech, Iwona; Staciwa, Piotr; Akdogan, AbdullahMicroporous carbon spheres (MCSs) are advanced materials known for their high surface area, well-developed pore structure, low density, and rapid molecular diffusion, making them highly effective in solid-phase extraction (SPE) and other applications. In this study, MCSs synthesized from previously reported resorcinol-formaldehyde resin were employed as an adsorbent for the extraction and preconcentration of Pb(II) ions. The material was comprehensively characterized to confirm its suitability for adsorption applications. The adsorption and desorption behavior of MCSs toward lead ions was systematically examined under optimized conditions, including pH, eluent volume, eluent type, eluent concentration, and sample volume. Microinjection microsample injection system-flame atomic absorption spectrometry (MIS-FAAS) was used for the determination of lead ions. Experimental results from batch experiments showed that the MCSs exhibited a maximum adsorption capacity of 37.31 mg g-1. Under optimal conditions (pH 8.0, 1.0 mL of 0.1 M HNO3 eluent, and 10 mg of adsorbent), a preconcentration factor of 100 was achieved, with recovery values exceeding 90%. The method exhibited a limit of detection (LOD) of 0.73 mu g L-1. The developed method was successfully applied to real water samples, including tap water, entering industrial wastewater, and exiting industrial wastewater, confirming its potential for use in environmental monitoring and contamination control.Editorial Editorial: Advancing Biotechnology in Turkiye: a Dedication To All Women(Springer, 2025) Cadirci, Bilge Hilal; Buyukkileci, Ali Oguz; Binay, BarisArticle Pvc/Pan-immobilized H2TiO3 Adsorbent: a Tailored Titanium-Based Lithium-Ion Sieve for High-Performance Lithium Recovery(Royal Soc Chemistry, 2025) Recepoglu, Yasar Kemal; Ipek, Onur; Yuksel, AsliThe increasing demand for lithium, driven by the rapid development of electric vehicles and energy storage systems, has created a pressing need for efficient and sustainable lithium recovery technologies. Conventional methods often face challenges related to selectivity, environmental impact, and scalability, necessitating the development of alternative materials. In this study, a polyvinyl chloride/polyacrylonitrile (PVC/PAN)-immobilized titanium-based lithium-ion sieve (HTO) was synthesized for lithium recovery from aqueous media, including geothermal brine. The objective was to obtain a selective, reusable, and mechanically stable adsorbent suitable for industrial-scale applications. The synthesized PVC/PAN-HTO composite was characterized by FT-IR, BET, XRD, and SEM techniques. Batch adsorption studies showed that the optimum lithium recovery occurred at pH 12, with efficiencies of 98.7% in model lithium solutions and 91.6% in geothermal water using a 4 g L-1 adsorbent dosage. Adsorption kinetics followed a pseudo-second-order model, and the Langmuir isotherm provided the best fit, indicating monolayer adsorption with a maximum capacity of 5.79 mg g-1. Thermodynamic analysis confirmed that the adsorption process is spontaneous and exothermic. Reusability tests demonstrated stable performance over three adsorption-desorption cycles, confirming the potential of PVC/PAN-HTO for practical lithium extraction applications.Article Citation - WoS: 1Citation - Scopus: 1Spiral-Shaped Dual-Port Microstrip Antenna for 5G/6G Applications With Wideband-To Transition Using Shape-Memory Alloy(Iop Publishing Ltd, 2025) Atac, Enes; Karatay, AnilWe propose a compact, thermally reconfigurable dual-port microstrip antenna featuring a spiral-shaped design and shape-memory alloy (SMA) that enable switching between wideband and narrowband operation for 5G/6G communication systems. The SMA's thermally induced shape-memory behavior allows reconfiguration in response to temperature changes without the need for electronic or optical control circuits, thus avoiding issues such as self-interference problem, high costs, regular maintenance requirements, and durability concerns. In the wideband mode, measured results show that Port 1 covers 4.7-10.5 GHz and Port 2 covers 4.5-8.3 GHz, which closely agrees with simulations. When the SMA is activated by heat, the antenna switches to the narrowband mode, where Port 1 operates at 7.6 and 9.5 GHz, and Port 2 operates at 8.9 GHz. A ground-plane isolation element ensures low coupling between the ports, with the envelope correlation coefficient remaining below 0.1 across all configurations. The antenna reaches a peak gain of 5.2 dBi and maintains consistent performance through repeated switching. By combining spiral-shaped geometry with a responsive smart material, this work presents a novel and efficient approach for designing reconfigurable dual-port antennas suitable for future wireless technologies.Article Influence of Soil Characteristics on the Phytochemistry of Evergreen Ivy (Hedera Helix L.) Leaves in Deciduous Forests(Wiley-v C H verlag Gmbh, 2025) Yildirim, Elif Begum; Ozer, Gulcin; Sen, Nisa Beril; Ozdemir, Emrah; Makineci, Ender; Ozdemir, Durmus; Guzelmeric, EtilThe evergreen ivy (Hedera helix L.), traditionally used to treat respiratory conditions, contains triterpene saponins, primarily hederacoside C, and various phenolic compounds. This study investigated the relationships between the chemical composition of ivy leaves and their natural growing conditions (moisture, temperature, pH, and electrical conductivity of soil). Ivy leaves were collected monthly over 1 year from oak and beech forests. Hederacoside C, rutin, chlorogenic acid (ChA), neoChA, 4,5-dicaffeoylquinic acid (DCQA), and 3,5-DCQA were analyzed by high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC). Soil parameter data, along with the quantitative HPLC results of ivy leaves, were first subjected to bivariate analysis, which revealed significant correlations, particularly between soil moisture, soil temperature, and the chemical composition of ivy leaves. In addition, ivy samples were classified and clustered based on seasons by principal component analysis (PCA) and hierarchical cluster analysis (HCA), regardless of their collection sites. Digitized HPTLC chromatograms were evaluated by PCA and partial least squares discriminant analysis (PLS-DA) analyses; PCA enabled the grouping of ivy leaves based on their collection sites, and PLS-DA categorized the samples by seasons. The evaluation of the relationships between the phytochemistry of ivy leaves and their natural growing conditions has been reported for the first time.Article Rings Whose Mininjective Modules Are Injective(Taylor & Francis inc, 2025) Alagoz, Yusuf; Benli-Goral, Sinem; Buyukasik, Engin; Garcia Rozas, Juan Ramon; Oyonarte, LuisThe main goal of this paper is to characterize rings over which the mininjective modules are injective, so that the classes of mininjective modules and injective modules coincide. We show that these rings are precisely those Noetherian rings for which every min-flat module is projective and we study this characterization in the cases when the ring is Kasch, commutative and when it is quasi-Frobenius. We also treat the case of nxn upper triangular matrix rings, proving that their mininjective modules are injective if and only if n=2. We use the developed machinery to find a new type of examples of indigent modules (those whose subinjectivity domain contains only the injective modules), whose existence is known, so far, only in some rather restricted situations.