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Article Citation - WoS: 32Electrospun 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.Article Citation - WoS: 8Citation - Scopus: 12Srcmimm: the Software Requirements Change Management and Implementation Maturity Model in the Domain of Global Software Development Industry(Springer, 2023) Akbar, Muhammad Azeem; Khan, Arif Ali; Mahmood, Sajjad; Mishra, AlokThe software industry has widely adopted global software development (GSD) to gain economic benefits. Organizations that engage in GSD face various challenges, the majority being associated with requirements change management (RCM). The key motive of this study is to develop a requirement change management and implementation maturity model (SRCMIMM) for the GSD industry that could help the practitioners to assess and manage their RCM activities. A systematic literature review and questionnaire survey approach are used to identify and validate the critical success factors (CSFs), critical challenges (CCHs), and the related best practices of the RCM process. The investigated CSFs and CCHs are classified into five maturity levels based on the concepts of the existing maturity models in other domains, practitioners' feedback, and academic research. Every maturity level comprises different CSFs and CCHs that can help assess and manage a firm's RCM capability. To evaluate the effectiveness of the proposed model, four case studies are conducted in different GSD firms. The SRCMIMM has been developed to assist GSD organizations in improving their RCM process in efficiency and effectiveness.Article Citation - WoS: 39Citation - Scopus: 40Illumination and Voltage Effects on the Forward and Reverse Bias Current-Voltage (i-V) Characteristics in In/In2< Photodiodes(Springer, 2021) Yukselturk, Esra; Surucu, Ozge; Terlemezoglu, Makbule; Parlak, Mehmet; Altindal, SemsettinThe illumination and voltage effects on the I-V measurements of the fabricated In/In2S3/p-Si photodiode were investigated in dark and under various illumination intensities (20-100 mW/cm(2)) between +/- 2 V. Two linear regions in the forward-bias ln(I)-V plots were observed. The value of diode ideality factor (n) had an increasing trend with increasing illumination intensity while the barrier height (phi(Bo)) had a decreasing trend due to the increase of photocurrent. The photodiode properties were also investigated, and the value of linear-dynamic value range (LDR) was found to be 20.56 dB. The photoresponse (I-ph/I-dark), the photoresponsivity (R), and specific detectivity (D*) of the photodiode were calculated as a function of the illumination. The open-circuit voltage (V-oc) and short-current (I-sc) were found to be 0.36 V and 2.87 mA under 100 mW.cm(-2) illumination intensity, respectively. The possible conduction mechanisms (CMs) were investigated using the forward ln(I)-V and reverse ln(I)-V-0.5 plots. The energy-dependent surface states (N-ss) profile was extracted from the positive I-V data by considering voltage-dependent barrier height (BH) and ideality factor (n) in dark and illumination at 100 mW/cm(2).Article Citation - WoS: 9Citation - Scopus: 8Exploring the Optical Dynamics in the Ito/As2< Interfaces(Springer, 2019) Al Garni, S. E.; Qasrawi, A. F.In this work, the effects of indium tin oxide (ITO) substrates on the structural, compositional, optical dielectric and optical conduction properties of arsenic selenide thin films are investigated. The As2Se3 films which are prepared by the thermal deposition technique under vacuum pressure of 10(-5) mbar exhibit an induced crystallization process, improved stoichiometry, increased optical transmittance in the visible range of light and increased dielectric response in the infrared range of light upon replacement of glass substrates by ITO. The ITO/As2Se3 interfaces exhibit conduction and valence band offset values of 0.46 eV and 0.91 eV, respectively. The experimental optical conductivity spectra are theoretically reproduced with the help of the Drude-Lorentz approach for optical conduction. In accordance with this approach, owing to the improved crystallinity of the arsenic selenide, the deposition of As2Se3 onto ITO substrates increases the drift mobility value from similar to 17.6 cm(2)/Vs to 34.6 cm(2)/Vs. It also reduces the density of free carriers by one order of magnitude. The ITO/As2Se3/C heterojunction devices which are tested as band filters which may operate in the frequency domain of 0.01-3.0 GHz revealed low pass filter characteristics below 0.35 GHz and band pass filter characteristics in the remaining spectral range.Article Citation - WoS: 14Citation - Scopus: 24Generalized Alpha-Psi Type Mappings of Integral Type and Related Fixed Point Theorems(Springer, 2014) Karapinar, Erdal; Shahi, Priya; Tas, KenanThe aim of this paper is to introduce two classes of generalized alpha-psi-contractive type mappings of integral type and to analyze the existence of fixed points for these mappings in complete metric spaces. Our results are improved versions of a multitude of relevant fixed point theorems of the existing literature.Article Citation - WoS: 58Citation - Scopus: 74Internet Addiction Among College Students: Some Causes and Effects(Springer, 2019) Baturay, Meltem Huri; Toker, SacipInternet addiction among college students in terms of causes and effects are investigated. Correlation study method is utilized; structural equation modelling is applied to analyze the data. There are fifteen hypotheses generated for the model. The data is collected via numerous instruments proven as reliable and valid by the previous studies. There are 159 undergraduate students as participants of the study. Antecedent variables are game addiction, bad relationships with friends, family and professors, neglecting daily chores, hindrance of sleep pattern, use internet for researching, weekly internet use hours, leisure time activities, reading and playing computer games. Consequence variables are self-esteem, self-confidence, social self-efficacy, loneliness, and academic self-efficacy. The results indicates that game addiction, neglecting daily chores, bad relationships with professors are significantly associated with internet addiction. Internet addiction decreases one's self-esteem, self-confidence, social self-efficacy, academic self-efficacy and triggers loneliness. Parents, professors and educational institutions may be illuminated about prevention or monitoring of internet addiction. The current study investigates Internet addiction with respect to its implications for social behavioral, and psychological phenomenon but not in a clinical sense. Hence, studies on Internet addiction merely concentrate on antecedents and features that may cause more addiction; however, both antecedents and consequences are not examined. The value of the current study is to provide more systematic, comprehensive, and theory-based empirical causations via structural equation models. The model may help to diagnose Internet Addiction and illuminate college students its potential harmful socio-psychological consequences.Article Citation - WoS: 9Citation - Scopus: 12Social Support and Help-Seeking Worldwide(Springer, 2024) Szkody, Erica; Spence, Anjolee; Ozdogru, Asil; Tushir, Bhawna; Chang, Fennie; Akkas, Handan; Cascalheira, Cory J.Social support has long been associated with positive physical, behavioral, and mental health outcomes. However, contextual factors such as subjective social status and an individual's cultural values, heavily influence social support behaviors (e.g., perceive available social support, accept support, seek support, provide support). We sought to determine the current state of social support behaviors and the association between these behaviors, cultural values, and subjective social support across regions of the world. Data from 6,366 participants were collected by collaborators from over 50 worldwide sites (67.4% or n = 4292, assigned female at birth; average age of 30.76). Our results show that individuals cultural values and subjective social status varied across world regions and were differentially associated with social support behaviors. For example, individuals with higher subjective social status were more likely to indicate more perceived and received social support and help-seeking behaviors; they also indicated more provision of social support to others than individuals with lower subjective social status. Further, horizontal, and vertical collectivism were related to higher help-seeking behavior, perceived support, received support, and provision of support, whereas horizontal individualism was associated with less perceived support and less help-seeking and vertical individualism was associated with less perceived and received support, but more help-seeking behavior. However, these effects were not consistently moderated by region. These findings highlight and advance the understanding of how cross-cultural complexities and contextual distinctions influence an individual's perception, processing, and practice of social support embedded in the changing social landscape.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: 14Analysis 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: 11Citation - Scopus: 12A 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.
