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Article Citation - WoS: 1Citation - Scopus: 1Principal and Nonprincipal Solutions of Impulsive Dynamic Equations: Leighton and Wong Type Oscillation Theorems(Springer, 2023) Zafer, A.; Akgol, S. Dogru; Doğru Akgöl, S.Principal and nonprincipal solutions of differential equations play a critical role in studying the qualitative behavior of solutions in numerous related differential equations. The existence of such solutions and their applications are already documented in the literature for differential equations, difference equations, dynamic equations, and impulsive differential equations. In this paper, we make a contribution to this field by examining impulsive dynamic equations and proving the existence of such solutions for second-order impulsive dynamic equations. As an illustration, we prove the famous Leighton and Wong oscillation theorems for impulsive dynamic equations. Furthermore, we provide supporting examples to demonstrate the relevance and effectiveness of the results.Article Citation - WoS: 14Citation - Scopus: 15Analysis of Temperature-Dependent Forward and Leakage Conduction Mechanisms in Organic Thin Film Heterojunction Diode With Fluorine-Based Pcbm Blend(Springer, 2020) Yildiz, D. E.; Gullu, H. H.; Toppare, L.; Cirpan, A.The forward and reversed biased current-voltage behaviors of the organic diode were detailed in a wide range of temperatures. In this diode, a donor-acceptor-conjugated copolymer system was constructed with poly((9,9-dioctylfluorene)-2,7-diyl-(2-dodecyl-benzo[1,2,3]triazole)) as a partner of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Two-order of magnitude rectification ratio was achieved, and the temperature-dependent values of saturation current, zero-bias barrier height, and ideality factor were extracted according to the thermionic emission model. The temperature responses of these diode parameters showed an existence of inhomogeneity in the barrier height formation. As a result, the observed non-ideal behavior was explained by Gaussian distribution of barrier height where low-barrier regions are effective in the forward biased conduction mechanism at low temperatures. Together with this analysis, series resistances were evaluated using Cheung's functions and also density of interface states were investigated. On the other hand, reverse biased current flow was found under the dominant effect of Poole-Frenkel effects associated with these interfacial traps. The reverse current conduction mechanism was detailed by calculating characteristic field-lowering coefficients and barrier height values in the emission process from the trapped state in the range of temperatures of interest.Article Citation - WoS: 12Citation - Scopus: 13A New Mixed Δ-Shock Model With a Change in Shock Distribution(Springer, 2023) Chadjiconstantinidis, Stathis; Tuncel, Altan; Eryilmaz, SerkanIn this paper, reliability properties of a system that is subject to a sequence of shocks are investigated under a particular new change point model. According to the model, a change in the distribution of the shock magnitudes occurs upon the occurrence of a shock that is above a certain critical level. The system fails when the time between successive shocks is less than a given threshold, or the magnitude of a single shock is above a critical threshold. The survival function of the system is studied under both cases when the times between shocks follow discrete distribution and when the times between shocks follow continuous distribution. Matrix-based expressions are obtained for matrix-geometric discrete intershock times and for matrix-exponential continuous intershock times, as well.Article Citation - WoS: 36Citation - Scopus: 44Lyapunov-Type Inequalities for Mixed Non-Linear Forced Differential Equations Within Conformable Derivatives(Springer, 2018) Abdeljawad, Thabet; Agarwal, Ravi P.; Alzabut, Jehad; Jarad, Fahd; Ozbekler, AbdullahWe state and prove new generalized Lyapunov-type and Hartman-type inequalities fora conformable boundary value problem of order alpha is an element of (1,2] with mixed non-linearities of the form ((T alpha X)-X-a)(t) + r(1)(t)vertical bar X(t)vertical bar(eta-1) X(t) + r(2)(t)vertical bar x(t)vertical bar(delta-1) X(t) = g(t), t is an element of (a, b), satisfying the Dirichlet boundary conditions x(a) = x(b) = 0, where r(1), r(2), and g are real-valued integrable functions, and the non-linearities satisfy the conditions 0 < eta < 1 < delta < 2. Moreover, Lyapunov-type and Hartman-type inequalities are obtained when the conformable derivative T-alpha(a) is replaced by a sequential conformable derivative T-alpha(a) circle T-alpha(a), alpha is an element of (1/2,1]. The potential functions r(1), r(2) as well as the forcing term g require no sign restrictions. The obtained inequalities generalize some existing results in the literature.Conference Object Citation - Scopus: 2Prioritizing Use Cases for Development of Mobile Apps Using Ahp: a Case Study in To-Do List Apps(Springer, 2019) Yildirim,O.; Peker,S.With the rapid development of communication technologies, the uses of mobile apps have increased in a significant manner over the past few years. Every day many different types of mobile apps are uploaded to mobile application markets. However, it is very difficult for the apps to stay competitive and survive in these marketplaces. Covering the requirements fitting the needs of users is one of significant factors in mobile apps’ success in the market. In this regard, this study aims to use Analytic Hierarchy Process (AHP) to evaluate the use cases for the development of mobile apps. The results show that AHP provides an efficient tool which can be used to determine importance of the requirements in mobile apps considering users’ preferences. © 2019, Springer Nature Switzerland AG.Conference Object Citation - WoS: 16Citation - Scopus: 18Determinants of Entry in Turkish Manufacturing Industries(Springer, 2006) Gunalp, Burak; Cilasun, Seyit MuminThe entry of new firms into markets plays an important role in efficient resource allocation and evolution for long term economic growth. Employing dynamic panel data techniques, this paper investigates entry behavior in 66 four-digit Turkish manufacturing industries for the 1993-1999 period. The results of this paper suggest that potential entrants observe the market before the entry takes place; entry is, in general, a follow-up process; and incumbent firms seem to collude to prevent entry in Turkish manufacturing industries. In addition, the real interest rate appears to be a very important determinant of entry decision.Book Part Citation - Scopus: 2Materials and Processes for Treatment of Microbiological Pollution in Water(Springer, 2021) Alazzawi,M.; Turkoglu Sasmazel,H.Clean and safe water is vital for the life and health of human beings. However, there are still millions of people around the world with inadequate clean water sources. Microbiological pollution is one of the most concerned water pollutants and is the crucial cause of waterborne diseases like diarrhea, resulting in about two million deaths annually due to severe dehydration (WHO in Guidelines for drinking-water quality. Incorporating the first addendum, WHO, Geneva, 2017). It is critical to develop methods using advanced materials and process to mitigate contaminants from water resources. Production of safe water usually involves disinfection and decontamination processes. Conventional disinfection process, such as chlorination, is challenged by the formation of disinfection by-products. Furthermore, the presence of emerging pathogenic, that resist conventional water treatment techniques, raised the crucial necessity for emerging materials and techniques for treating water from microbiological pollution (Shannon et al. in Nature 452:301–310, 2008). This chapter describes bacterial, viral, and protozoal microbiological pollution in water supplies and the application of emerging materials and techniques to eliminate such contaminations. © 2021, Springer Nature Switzerland AG.Article Citation - WoS: 33Citation - Scopus: 37Discrete Sizing Optimization of Steel Trusses Under Multiple Displacement Constraints and Load Cases Using Guided Stochastic Search Technique(Springer, 2015) Azad, S. Kazemzadeh; Hasancebi, O.The guided stochastic search (GSS) is a computationally efficient design optimization technique, which is originally developed for discrete sizing optimization problems of steel trusses with a single displacement constraint under a single load case. The present study aims to investigate the GSS in a more general class of truss sizing optimization problems subject to multiple displacement constraints and load cases. To this end, enhancements of the GSS are proposed in the form of two alternative approaches that enable the technique to deal with multiple displacement/load cases. The first approach implements a methodology in which the most critical displacement direction is considered only when guiding the search process. The second approach, however, takes into account the cumulative effect of all the critical displacement directions in the course of optimization. Advantage of the integrated force method of structural analysis is also utilized for further reduction of the computational effort in these approaches. The proposed enhancements of GSS are investigated and compared with some selected techniques of design optimization through six truss structures that are sized for minimum weight. The numerical results reveal that both enhancements generally provide promising solutions with an insignificant computational effort.Editorial Preface(Springer, 2020) Peng, Zhiwei; Hwang, Jiannyang; Downey, Jerome, P.; Gregurek, Dean; Zhao, Baojun; Yücel, Onuralp; Mahmoud, Morsi, M.Article Citation - WoS: 33Electrospun Essential Oil-Polycaprolactone Nanofibers as Antibiofilm Surfaces Against Clinical Candida Tropicalis Isolates(Springer, 2019) Sahal, Gulcan; Nasseri, Behzad; Ebrahimi, Aliakbar; Bilkay, Isil SeyisObjectiveAs an approach to prevent biofilm infections caused by Candida tropicalis on various surfaces, determination of effect of biodegradable polycaprolactone nanofibers (PCLNFs) with different concentrations of two different essential oils were tested in this study.ResultsBoth of the tested essential oils exhibited antifungal effect (minimal inhibitory concentration; 0.25-0.49 mu L/mL, minimal fungicidal concentration; 0.25-0.49 mu L/mL, depending on the C. tropicalis strain) (Zone of inhibition caused by 500 L/mL concentration of oils; 28-56mm). 0, 2, 4% clove oil PCLNFs and 0, 2, 4% red thyme oil-PCLNFs were free from bead formation and uniform in diameter. Diameters of all essential oil containing PCLNFs were ranged from 760 to 1100nm and were significantly different from 0% essential oil-PCLNF (P<0.05). 0, 2, 4% clove oil-PCLNFs were significantly more hydrophobic compared to 8% clove oil-PCLNF (P<0.01), whereas 0% and 2% red thyme oil-PCLNFs were significantly more hydrophobic compared to 4% and 8% red thyme oil PCLNFs (P<0.01). Highest amount of biofilm inhibition was observed by 4% clove oil-PCLNF and by 4% red thyme oil-PCLNF.ConclusionsClove and red thyme oils may be used not only as antifungals but also as biofilm inhibitive agents on surfaces of biomaterials that are frequently contaminated by C. tropicalis, when they are incorporated into PCLNFs.
