Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 7Citation - Scopus: 7Development of a Dopamine-Based Surface Modification Technique To Enhance Protein Fouling Resistance in Commercial Ultrafiltration Membranes(Elsevier, 2025) Onuk, Ecem; Gungormus, Elif; Cihanoglu, Aydin; Altinkaya, Sacide AlsoyThis study introduces a new method for modifying ultrafiltration membranes using dopamine polymerization to overcome issues such as prolonged polymerization times, potential pore narrowing, and insufficient formation of hydrophilic groups. The technique involves continuously supplying oxygen (O2) gas from the porous backside of the membrane while simultaneously applying an aqueous dopamine solution to the active top surface. TGA and XPS analyses revealed that 10 kDa commercial polysulfone (PSF) membranes coated with O2 backflow contained more dopamine than those modified using the classical method. Additionally, changes in contact angle and zeta potential values were more pronounced with the O2 backflow method. Dopamine coating for 10 and 20 min improved the pure water permeance of the PSF membrane, whereas a 40-min coating decreased it. Notably, the reduction in permeance was 2.5 times less with the O2 backflow method than with the classical method. The classical dopamine coating method did not enhance the PSF membrane's resistance to fouling during whey filtration; in fact, 20 and 40-min coatings caused more significant flux declines compared to the unmodified membrane. Conversely, 10 and 20 min of PDA coating under O2 backflow improved fouling resistance, though this benefit disappeared with a 40-min coating.Article Citation - WoS: 8Citation - Scopus: 8A Comprehensive Study of the Effect of Scanning Strategy on In939 Fabricated by Powder Bed Fusion-Laser Beam(Elsevier, 2024) Dogu, Merve Nur; Ozer, Seren; Yalcin, Mustafa Alp; Davut, Kemal; Obeidi, Muhannad Ahmed; Simsir, Caner; Brabazon, DermotThis study provides a comprehensive investigation into the effects of different scanning strategies on the material properties of IN939 fabricated using the PBF-LB process. The scanning strategies examined included alternating bi-directional scanning with rotation angles of 0 degrees, 45 degrees, 67 degrees, and 90 degrees between adjacent layers (named as shown), as well as alternating chessboard scanning with rotation angles of 67 degrees and 90 degrees (named as Q67 degrees and Q90 degrees). The results revealed that the 45 degrees and 67 degrees samples had the highest relative density, while the 0 degrees and Q67 degrees samples showed the highest average porosity. Moreover, various types of cracks, including solidification, solid-state, and oxide-induced cracks, were observed. Among the bi-directional scan samples, the 0 degrees sample displayed the most extensive cracking and the highest sigma max residual stress values in both XZ and XY planes. Conversely, the 45 degrees and 67 degrees samples exhibited fewer cracks. Notably, the lowest sigma max residual stress in the XZ planes among the bidirectional scan samples was observed in the 67 degrees sample. Additionally, microstructural analyses indicated differences in grain size and morphology, among the samples. Texture analysis indicated that the 0 degrees and 90 degrees samples exhibited strong cube textures, whereas the texture intensity weakened for the 45 degrees and 67 degrees samples. Moreover, the alternating chessboard scanning strategy led to rougher surfaces (higher Sa and Sz values) compared to the alternating bi-directional scanning strategy, regardless of the rotation angles. Furthermore, the microhardness values among the samples showed minimal variance, ranging between 321 + 14 HV and 356+ 7 HV.Article Citation - WoS: 4Citation - Scopus: 4Identification of Volatile Biomarkers in Exhaled Breath by Polythiophene Solid Phase Microextraction Fiber for Disease Diagnosis Using Gc-Ms(Elsevier, 2024) Pelit, Fusun; Goksel, Ozlem; Dizdas, Tugberk Nail; Arin, Aycan; Ozgur, Su; Erbas, Ilknur; Pelit, LeventThe diagnosis of diseases through monitoring of volatile organic compounds (VOCs) in exhaled breath (EB) holds great potential for clinical applications. However, a standardized method for VOC analysis in EB yet to be proposed. The present study presents an untargeted method for screening and identifying potential volatile biomarkers in EB by a lab-made solid phase microextraction (SPME) fiber. A polythiophene-based SPME fiber was produced by an electrochemical method and VOC sampling was performed under dynamic and controlled conditions. Following the sampling step, the adsorbed VOCs on the SPME fiber were analyzed using gas chromatography-mass spectrometry (GC-MS). The VOCs in EB were screened by the MS detector in selected ion monitoring (SIM) mode within the mass/charge (m/z) range of 13-94 values. Potential biomarkers among all detected VOCs in each subject's EB sample were identified through machine learning algorithms, employing a comparative analysis of distinctive retention times (RT) and peak areas between the lung cancer (LC) and control groups in two stages. In the initial stage of the study, the areas of all peaks observed in the SIM-GC-MS chromatograms of 25 LC and 51 control group subjects were integrated, and the resulting retention times and peak areas were recorded for subsequent analysis to identify potential biomarkers. A total of 1.346 distinct compounds were detected among the 76 subjects in this step, and statistical analysis using the LightGBM algorithm revealed the potential biomarkers for LC diagnosis. The PTh-SPME fibre successfully identified four novel cancer biomarkers in breath matrix: 4-heptenal, 4-methyl-1-octene, 1,2,3,4-tetrahydro-5,8-dimethyl-1-octylnaphthalene and tetrahydro-2-(2,5-undecadiynyloxy)-2H-pyran. In the second step of the study, the efficacy of the top ten selected biomarkers was evaluated in a cohort of 166 subjects, including 70 individuals with LC and 96 in the control group. The model achieved accuracy, area under the curve (AUC), and F Score values of 0.818, 0.816, and 0.817, respectively. The test model correctly predicted 27 out of 33 subjects between LC and control groups.Article Citation - WoS: 5Citation - Scopus: 5An Experimental and Comparative Study on Passive and Active Pcm Cooling of a Battery With/Out Copper Mesh and Investigation of Pcm Mixtures(Elsevier, 2024) Samancioglu, Umut Ege; Gocmen, Sinan; Madani, Seyed Saeed; Ziebert, Carlos; Nuno, Fernando; Huang, Jack; Cetkin, ErdalThe carbon emission contribution to global warming accelerated both research on and transition to electric vehicles (EVs). Drivers demand high power, fast acceleration and less charging times. All these demands require high C rate charging/discharging demands from batteries. The rate of heat generation is exponentially proportional to C rates which decreases battery lifetime and may lead to thermal runaway. However, a battery thermal management system decreases thermal runaway risk and decelerates battery degradation via controlling battery temperature. In this paper, we first document the thermal conductivity enhancement via copper foam into phase change material (PCM) domain to uncover their possible use in EV thermal management applications. Maximum 15.93 times increment is achieved with a specific copper foam. Then, physical properties and behaviors of distinct PCM mixtures are documented. Homogeneity of mixtures is associated with the chemistry of PCMs and the mixture melting point is proportional to the volume weighted average of melting temperatures. The results document that the PCM with relatively lower melting point is beneficial when end of discharge temperatures considered, except for high discharge rate of 2C. Temperature uniformity across the battery increases with relatively higher melting point PCM. Experiments also document that the amount of PCM volume lost via insertion of copper foam yields higher end of discharge temperatures. Overall, both PCM and copper foam enhances temperature homogeneity and their benefit becomes more sensible during drive cycles relative to continuous charge/discharge use cases.Article Citation - WoS: 2Citation - Scopus: 3Evaluation of the Source and Mechanisms of Groundwater Recharge for the Southern Sections of the Western Afar Rift Margin and Associated Rift Floor(Elsevier, 2024) Gidafie, Dereje; Nedaw, Dessie; Azagegn, Tilahun; Abebe, Bekele; Baba, AlperStudy area: Southern Sections of Western Afar rift margin and associated rift floor. Study focus: The purpose of this study is to identify the source and mechanisms of groundwater recharge based on geological, hydrochemical, and environmental isotope studies. New hydrogeological insights: The investigation illustrate that the columnar jointed basalt was extended from the plateau to the rift margin. In addition, transverse structures trending NW-SE and NE-SW connect the plateau to the rift margin and the marginal grabens to the rift floor. The hydrochemical interpretations with EC and TDS shows that the groundwater from the plateau has evolved from Ca-dominated and slightly mineralized to Na-dominated and highly mineralized to the rift floor. Isotopically, the deep groundwater systems are depleted in the entire physiography in contrast to the shallow groundwater systems. Radon measurements are higher at the outlets of the marginal grabens and between the rift margin and the rift floor, suggesting groundwater feeds the river. A comprehensive analysis of the aforementioned results suggests that the deep circulating groundwater is recharged in the plateau and escarpment and chemically altered with increasing depth and along its preferential flow path into the rift floor. Therefore, the plateau area is the main source of recharge for the western Afar rift margin and associated rift floor, due to the presence of preferential pathways, mainly the columnar jointed basalts and crossstructures.Article Citation - WoS: 1Citation - Scopus: 1Hydrothermal Synthesis, Characterization and Catalytic Activities of a Keggin Structure of (4,4′-Bpyh2)3[pw12o40]2•3h2o and a Wells-Dawson Structure of (4,4′-Bpyh2)3(4,4′(Elsevier, 2025) Ece, Ozlem; Chilufya, Langson; McMillen, Colin D.; Emirdag-Eanes, MehtapTwo novel polyoxometalates composed of heteropolytungstates, (4,4 '-bpyH2)3[PW12O40]2 center dot 3H2O (1) and (4,4 '- bpyH2)3(4,4 '-bpyH)1.75[Cu(bpy)2]0.25[H2P2W18O62]2 (2) have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction and TGA methods. Compound 1 crystallizes in the cubic space group Ia-3with a = 25.9356(12) angstrom, b = 25.936(3) angstrom, c = 25.936(3) angstrom, alpha = 90.00, (3= 90.00, gamma= 90.00 and Z = 8, and compound 2 crystallizes in the triclinic space group P-1with a = 13.5194(17) angstrom, b = 22.400(3) angstrom, c = 27.374(4) angstrom, alpha = 79.833(3), (3= 77.439(3), gamma= 80.213(4) and Z = 2. In addition to structural characterization, the catalytic activities of 1 and 2 were determined in hydrolysis reactions. In the catalytic study, starch hydrolysis reactions were performed by using hydrothermal synthesis, and starch was hydrolyzed successfully at 150 degrees C, 5 h, based on the results of Lugol's test, which highest conversion yields above 90 wt.% under optimum reaction conditions. FT-IR analysis and catalyst reusability tests were also performed for each compound. No appreciable loss was observed in activity after five reaction cycles.Book Part Citation - Scopus: 16Kinetic and Process Modeling of Uv-C Irradiation of Foods(Elsevier, 2020) Atilgan,M.R.; Yildiz,S.; Kaya,Z.; Unluturk,S.Ultraviolet (UV-C) radiation is a nonthermal technology that has emerged as an alternative to heat treatment to extend the shelf life and improve safety of foods. The design of UV-C systems to comply with current food safety goals is still challenging. The engineering approaches differ from those employed for water treatment due to low penetration depth of UV-C light in liquid foods. Furthermore, the application of UV-C irradiation for disinfection of food surfaces is a complex process. It is required an accurate assessment of absorbed UV-C dose to overcome the shadowing effect in solid foods. © 2021 Elsevier Inc. All rights reserved.Book Part Citation - Scopus: 3Overview of the Dry Milling Versus Wet Milling(Elsevier, 2024) Paksoy,A.; Arabi,S.; Balcı-Çağıran,Ö.Dry milling and wet milling are well-established fields of materials science. Both methods are low-cost and offer advantages such as desired phase synthesis, modifications of microstructure and morphology, mechanical enhancements, and chemical activation. They contribute to developing high-quality products for applications in the aerospace, automotive, and defense industries, refractories, and structural materials. This chapter is about current information on the impact of dry milling and wet milling on the compositions, fine structures, morphological, thermal, and rheological characteristics of different types of materials. What dry and wet milling techniques are and how they occur are explained through definitions and mechanisms. Effective parameters for both methods are categorized separately. In this way, details on the parameters and circumstances that must be considered in experimental studies were provided. There are also case investigations to compare the effects of dry milling and wet milling on the materials. © 2024 by Elsevier Inc. All rights reserved.Article Citation - WoS: 13Citation - Scopus: 11Effect of Aging Treatment on the Microstructure, Cracking Type and Crystallographic Texture of In939 Fabricated by Powder Bed Fusion-Laser Beam(Elsevier, 2024) Ozer, Seren; Dogu, Merve Nur; Ozdemirel, Ceren; Bilgin, Guney Mert; Gunes, Mert; Davut, Kemal; Brabazon, DermotThis study aimed to provide a comprehensive understanding of how aging treatments (namely, HT1 and HT2) affect the microstructure, cracking behavior, and crystallographic texture of IN939 fabricated by powder bed fusion-laser beam (PBF-LB) method. Although both aged samples demonstrated similar grain structure and recrystallization behavior according to the electron backscatter diffraction (EBSD) analysis, as well as the precipitation of bimodal gamma ' phase and MC- and M23C6-type carbides, notable differences were observed in the size and morphology, particularly the gamma ' phase. The HT1 sample displayed coarsened primary gamma ' phase, with sizes reaching up to 2 mu m and exhibiting varied morphologies, including irregular and cuboidal shapes. Additionally, this treatment led to the formation of some gamma '-gamma eutectic regions and plate-like eta phase, along with the decomposition of MC-type carbides into M23C6-type carbides. In contrast, the HT2 sample displayed uniformly distributed spherical primary gamma ' phase with sizes ranging from 70 to 120 nm, accompanied by very fine secondary gamma ' phase. Furthermore, it was found that changes in both aged sample microstructures could result in the formation of strain-age cracks due to the gamma ' phase formation and liquation cracks due to the partial remelting of lower melting point phases. The findings also revealed that with the application of aging treatments, the hardness of the as-fabricated sample (339.8 +/- 3.4 HV) increased to 440.2 +/- 5.6 HV and 508.1 +/- 4.8 HV for the heat treatment of HT1 and HT2, respectively.Book Part Telemedicine Applications for Pandemic Diseases, With a Focus on Covid-19(Elsevier, 2021) Tarim,E.A.; Karakuzu,B.; Oksuz,C.; Tekin,H.C.Dating back to the development of modern medicine, pandemic and epidemic diseases, such as bubonic plague, smallpox, the plague of Justinian, and the Antonine Plague, have caused massive damage to the human race. For instance, more than 200 million people are estimated to have died due to Black Death (bubonic plague) alone. This situation has not changed in near history either. Diseases such as influenza, HIV/AIDS, severe acute respiratory syndrome, Ebola, Middle East respiratory syndrome, and coronavirus disease 2019 (COVID-19), as today, have emerged and threatened the modern human life. The common feature of these diseases can be listed as having a high risk of infection and transmission, rapidly spreading to large areas, and having high mortality rates and causing permanent damage to the body because of the low immunity profile of the exposed population. If the number of cases increases rapidly for these diseases, the capacity of healthcare services can be exceeded and healthcare services can be threatened as well. These characteristics of pandemic diseases force the authorities to take extraordinary precautions such as isolation and quarantine to reduce the risk of infection. However, these applications can make it difficult to provide proper health services to patients. The development of information technologies provides patients an easy and remote access to healthcare services via telemedicine applications. Telemedicine is used for diagnosis and treatment of diseases by following the same practices used in clinics. It also provides care givers a real-time and remote monitoring of their patients, which can be beneficial in terms of reducing the risk of infections and maintaining healthcare services during a pandemic. Authorities can also use these telemedicine applications to track infected patients and get necessary precaution to minimize the infection risk. This chapter introduces the latest telemedicine applications for epidemic and pandemic diseases, especially for COVID-19. These potential applications could improve and transform the current practices for pandemic disease management. © 2022 Elsevier Inc.