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Article Citation - WoS: 9Citation - Scopus: 9Benchmarking Classification Models for Cell Viability on Novel Cancer Image Datasets(Bentham Science Publ Ltd, 2019) Ozkan, Akin; Isgor, Sultan Belgin; Sengul, Gokhan; Isgor, Yasemin GulgunBackground: Dye-exclusion based cell viability analysis has been broadly used in cell biology including anticancer drug discovery studies. Viability analysis refers to the whole decision making process for the distinction of dead cells from live ones. Basically, cell culture samples are dyed with a special stain called trypan blue, so that the dead cells are selectively colored to darkish. This distinction provides critical information that may be used to expose influences of the studied drug on considering cell culture including cancer. Examiner's experience and tiredness substantially affect the consistency throughout the manual observation of cell viability. The unsteady results of cell viability may end up with biased experimental results accordingly. Therefore, a machine learning based automated decision-making procedure is inevitably needed to improve consistency of the cell viability analysis. Objective: In this study, we investigate various combinations of classifiers and feature extractors (i.e. classification models) to maximize the performance of computer vision-based viability analysis. Method: The classification models are tested on novel hemocytometer image datasets which contain two types of cancer cell images, namely, caucasian promyelocytic leukemia (HL60), and chronic myelogenous leukemia (K562). Results: From the experimental results, k-Nearest Neighbor (KNN) and Random Forest (RF) by combining Local Phase Quantization (LPQ) achieve the lowest misclassification rates that are 0.031 and 0.082, respectively. Conclusion: The experimental results show that KNN and RF with LPQ can be powerful alternatives to the conventional manual cell viability analysis. Also, the collected datasets are released from the "biochem.atilim.edu.tr/datasets/ " web address publically to academic studies.Article Citation - WoS: 3Citation - Scopus: 4Optical Properties of Cu3in5< Single Crystals by Spectroscopic Ellipsometry(Elsevier Gmbh, 2018) Isik, M.; Nasser, H.; Ahmedova, F.; Guseinov, A.; Gasanly, N. M.Cu3In5S9 single crystals were investigated by structural methods of x-ray diffraction and energy dispersive spectroscopy and optical techniques of ellipsometry and reflection carried out at room temperature. The spectral dependencies of optical constants; dielectric function, refractive index and extinction coefficient, were plotted in the range of 1.2-6.2 eV from ellipsometric data. The spectra of optical constants obtained from ellipsometry analyses and reflectance spectra presented a sharp change around 1.55 and 1.50 eV, respectively, which are associated with band gap energy of the crystal. The critical point (interband transition) energies were also found from the analyses of second-energy derivative of real and imaginary components of dielectric function. The analyses indicated the presence of four critical points at 2.73, 135, 4.04 and 4.98 eV.Article Citation - WoS: 13Citation - Scopus: 13Crustal Thickness in the Black Sea and Surrounding Region, Estimated From the Gravity Data(Elsevier Sci Ltd, 2021) Bilim, Funda; Aydemir, Attila; Ates, Abdullah; Dolmaz, M. Nuri; Kosaroglu, Sinan; Erbek, EzgiIn this research, the crustal thickness (Moho depth) variations in the Black Sea and surrounding region were calculated from the regional gravity anomaly data using an empirical equation. The data were obtained from the open source of Bureau Gravimetrique International (BGI) in digitized form. The gravity anomaly values are changing from 80 mGal in the onshore Black Sea region in Turkey to 260 mGal in the deeper parts of the sea. Maximum gravity anomaly indicates a consistent pattern in the offshore Black Sea and anomaly pattern follows the shape of the shoreline. The pattern is consistent with the deeper parts in the marine area and the eastern anomaly extends into the Russian territory between NW of Georgia and SE of the Crimean Peninsula. The crustal thickness map indicates almost the same trends. In this map, the minimum crustal thickness is about 10 km around the mid of the Shatsky Ridge, close to the coastal regions of SE Russia and the second thinnest (12 km) place is located around the Western Black Sea Basin. The maximum thicknesses are represented with the 34-36 km contours in the onshore Eastern Black Sea region and east of Anatolia. On the other hand, the maximum crustal thickness to the north can reach up to 28 km around the Sea of Azov and to the east. The thickness variations are generally related with the main tectonic trends in this region. The Analytic Signal (AS) and maxima points of the horizontal gradients (maxspots) maps constructed from the gravity anomalies are also prepared in this research to see if these anomaly trends follow the tectonic lines. The regions of maximum and minimum crustal thicknesses are well-consistent with the AS anomalies and boundaries of the bifocal thin crustal sections coinciding with the Eastern and Western Black Sea basinal parts are surrounded with the maxspots. The northern thick crustal region around the southern margin of the Indolo-Kuban Basin is also surrounded by the maxspots. It is possible to claim that the maxspots map from the horizontal gradient of Bouguer anomalies reflects the boundaries of the main tectonic units in the Black Sea Region. Particularly, southern boundary of the Scythian Platform, southern boundary of the Shatsky Ridge and Great Caucasus thrust are distinctive and easy to follow in the maxspots map.Article Citation - WoS: 8Citation - Scopus: 8Complex Nodal Structure Phonons Formed by Open and Closed Nodal Lines in Coass and Na2cup Solids(Royal Soc Chemistry, 2022) Ding, Guangqian; Sun, Tingting; Surucu, Gokhan; Surucu, Ozge; Gencer, Aysenur; Wang, XiaotianTopological phononic states with nodal lines not only have updated our knowledge of the phases of matter in a fundamental way, but also have become a major frontier research direction in condensed matter physics. From a mathematical perspective, nodal line phonons can be divided into open and closed types. The present attempt is a report on the coexistence of such open and closed nodal line phonons in two realistic solids, CoAsS and Na2CuP, based on first-principles calculations. Furthermore, it is shown that the closed and the open nodal line states in CoAsS and Na2CuP have touching points and can form a complex nodal structure phonon in a momentum space. Due to the topologically non-trivial behavior of the complex nodal structure in both phonons, evident phononic surface states occur in the projected surfaces of both materials. In this way, these states, arising from the projected crossing points, can benefit experimental detection in follow-up studies. It has been stated that the open and closed nodal line states are formed by the crossings of two phonon branches and, hence, these two types of nodal line phonons are coupled with each other. The results obtained here could be considered as a breakthrough in clearly demonstrating the coexistence of the open and closed nodal line states in phonons and, for this reason, may inspire researchers seeking materials with such topological states in other bosons, such as photons.Article Citation - WoS: 3Citation - Scopus: 5Predictive Rental Values Model for Low-Income Earners in Slums: the Case of Ijora, Nigeria(Taylor & Francis Ltd, 2023) Iroham, Chukwuemeka O.; Misra, Sanjay; Emebo, Onyeka C.; Okagbue, Hilary, IIt is well known most often that values of properties tend to hike at the effluxion of time. This has necessitated the adoption of predictive models in interpreting outcomes in the property market in the future. Earlier studies have been oblivious of such models' outcomes as it affects any focal group, particularly the vulnerable. This present study focuses on the low-income earners found in the slum. The Ijora community in Lagos was the highlight of this study, particularly Ijora Badia and Ijora Oloye, regarded as slums according to the UNDP report. The entire fifty-two (52) local agents in the Ijora community were surveyed in cross-sectional survey research that entailed the questionnaire's issuance. The nexus of data collection, pre-processing, data analysis, algorithm application, and model evaluation resulted in retrieving rental values within the years 2010 and 2019 on two predominant residential property types of self-contain and one-bedroom flats found within the community. Three selected algorithms, Artificial Neural Network (ANN), Support Vector Machine, and Logistic Regression, were essentially used as classifiers but trained to predict the continuous values. These algorithms were implemented through the use of Python's SciKit-learn Library and RapidMiner. The findings revealed that though all three models gave accurate predictions, Logistic Regression was the highest with low error values. It was recommended that Logistic Regression be applied but with much data set of property values of low-income earners over much more period. This study will contribute to the Sustainable development goals(SDG) 11(Sustainable cities and communities) of the United Nations to benefit developing countries, especially in sub-Saharan Africa.Article Citation - WoS: 27Citation - Scopus: 28Nature of the Ω (2012) Through Its Strong Decays(Springer, 2018) Aliev, T. M.; Azizi, K.; Sarac, Y.; Sundu, H.We extend our previous analysis on the mass of the recently discovered Omega (2012) state by investigation of its strong decays and calculation of its width employing the method of light cone QCD sum rule. Considering two possibilities for the quantum numbers of Omega (2012) state, namely 1P orbital excitation with J(P) = 3/2(-) and 2S radial excitation with J(P) = 3/2(+), we obtain the strong coupling constants defining the Omega (1P/2S) -> Xi K decays. The results of the coupling constants are then used to calculate the decay width corresponding to each possibility. Comparison of the obtained results on the total widths in this work with the experimental value and taking into account the results of our previous mass prediction on the Omega (2012) state, we conclude that this state is 1P orbital excitation of the ground state Omega baryon, whose quantum numbers are J(P) = 3/2(-).Article Citation - WoS: 5Citation - Scopus: 7Temperature-Dependent Electrical Resistivity, Space-Charge Current and Photoconductivity of Ga0.75in0.25< Single Crystals(Elsevier Science Bv, 2013) Isik, M.; Gasanly, N. M.Dark electrical resistivity, space-charge-limited (SCL) current and photoconductivity measurements were carried out on Ga0.75In0.25Se single crystals. Analysis of the dark resistivity measurements revealed the presence of one level with activation energy of 0.10 eV. Current voltage characteristics showed that both ohmic and SCL characters exhibit in 180-300 K range. Analysis of the experimental data in the SCL region resulted with a trap level at 0.11 eV above the valence band. Photoconductivity measurements were performed at different light intensities in the temperature range of 150-300 K. Behavior of the recombination mechanism in the crystal was brought out as sublinear recombination from the dependence of photocurrent on illumination intensity. Moreover, obtained activation energies were compared with the results of other experimental techniques applied to Ga0.75In0.25Se crystals in literature. (C) 2013 Elsevier B.V. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 4Financial Constraints and the ESG-Firm Performance Nexus in the Automotive Industry: Evidence From a Global Panel Study(MDPI, 2025) Dincergok, Burcu; Pirgaip, BurakThis study examines the complex relationship between environmental, social, and governance (ESG) and financial performance in the automotive industry, with a particular focus on how financial constraints shape this relationship. Using a global data set for the period 2008 to 2023 and employing a range of panel data techniques, including those addressing endogeneity concerns, we find that higher ESG scores positively affect financial performance. Specifically, a one-point rise in ESG score corresponds to an estimated 1-1.7% increase in the market-to-book ratio, with the effect reaching approximately 1.6% for firms facing financial constraints. These findings highlight the economic significance of ESG engagement, particularly for resource-constrained companies. The novelty of this study is that it focuses on the automotive sector, an industry with limited ESG-specific research, and that it makes a theoretical contribution by linking ESG performance outcomes to financial constraints, an angle largely overlooked in prior research. The findings offer critical policy insights, emphasizing the strategic importance of ESG initiatives for value creation under varying financial conditions.Article Citation - WoS: 12Citation - Scopus: 12Automorphisms of Curve Complexes on Nonorientable Surfaces(European Mathematical Soc, 2014) Atalan, Ferihe; Korkmaz, MustafaFor a compact connected nonorientable surface N of genus g with n boundary components, we prove that the natural map from the mapping class group of N to the automorphism group of the curve complex of N is an isomorphism provided that g + n >= 5. We also prove that two curve complexes are isomorphic if and only if the underlying surfaces are diffeomorphic.Article Citation - WoS: 14Citation - Scopus: 19Electrochemistry of nickel(II) complexes with N,N'-bis(3,5-di-tert-butylsalicylidene)polymethylenediamines(Pergamon-elsevier Science Ltd, 2005) Özalp-Yaman, S; Kasumov, VT; Önal, AMThe electrochemical oxidation of several N,N'-polymethylenebis(3,5-di-tert- butylsalicylaldiminato)nickel(II) complexes, Ni(L-x), has been studied by cyclic voltammetry and in situ UV-Vis spectroscopy in DMF Cyclic voltammograms of Ni(L-x) (x = 1-4) complexes displayed two-step oxidation processes under nitrogen gas atmosphere. The first oxidation peak potentials of all the Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. EPR spectrum of the electrolysis solution was recorded after one electron transfer at liquid nitrogen temperature also confirms the formation of [Ni-III (L-3)](+) species (g(x) > g(y) > g(z)) with a (2)A(1)(d(z)(2))(1) ground state. Upon addition of pyridine to one electron oxidised solutions a new penta coordinated species, [Ni-III(L-3)Py](+) (g(perpendicular to) > g(parallel to), a(parallel to)(N-14) = 8 G), was produced. The second oxidation peak of the complexes was assigned as the ligand based oxidation, generating a coordinated phenoxy radical species. (c) 2005 Elsevier Ltd. All rights reserved.
