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Article Citation - WoS: 17Citation - Scopus: 15Supply chain resilience in the tourism and hospitality industry: A comprehensive examination of driving and restraining forces(Elsevier Sci Ltd, 2024) Erol, Ismail; Oztel, Ahmet; Dogru, Tarik; Peker, Iskender; Neuhofer, Irem Onder; Benli, TolgaSupply chain disruptions and a lack of resilient supply chains have adverse impact on the global economy. Particularly, complex nature of the tourism and hospitality industry makes it even more susceptible to failure when supply chain resiliency is rather low or does not exist. However, despite its significance, a comprehensive and systematic examination of building resilience in tourism and hospitality supply chains (THSCs) is lacking in the extant literature. The purpose of this study is to develop a comprehensive framework that outlines the driving and restraining forces for building resilient THSCs. The decision framework proposed in this study integrates rough interval valued neutrosophic (RIVN) force field theory of change with RIVN-ISM-MICMAC methodology. The results showed that the restraining forces, such as lack of effective regulations and incentives and effective organizational and supply chain policies are the primary factors that constrain improving resilience in THSCs. Theoretical and practical implications are discussed.Article Citation - WoS: 8Citation - Scopus: 8Sns2 and Ho-Doped Sns2 Thin Films: Synergistic, Dft, Photocatalytic, and Antibacterial Studies(Elsevier Sci Ltd, 2024) Radja, Imane; Khane, Yasmina; Oliveira, Marisa C.; Longo, Elson; Ribeiro, Renan A. P.; Isik, Mehmit; Khan, Mohammad Mansoob; Mansoob Khan, MohammadThis study investigates Ho-doped tin disulfide (Ho-SnS2) thin films prepared via spray coating, focusing on varying Ho doping levels (0 at. %, 2 at. %, and 4 at. %). Structural analysis through XRD and SEM showcased enhanced crystallinity and morphology in Ho-SnS2 films. Raman and XPS studies provided insight into the film's composition and chemical states. The antibacterial properties of the films were investigated using a bacterial growth inhibition assay. The results showed significant antibacterial activity against Gram-positive and Gram-negative bacteria, highlighting the potential applications of Ho-SnS2 thin films in antibacterial coatings. Ho-SnS2 films exhibited superior photocatalytic activity and antibacterial properties compared to SnS2 films, attributed to efficient charge separation. DFT analysis proposed a mechanism for the antibacterial activity. These findings highlight the efficacy of the spray coating technique in producing Ho-SnS2 films and the potential of Ho-SnS2 films for diverse applications like photocatalysis and antibacterial coatings.Article Citation - WoS: 12Citation - Scopus: 13Performance of the Au/Mgo Photovoltaic Devices(Elsevier Sci Ltd, 2015) Khanfar, H. K.; Qasrawi, A. F.A 100 mu m thick MgO film is used to design a metal semiconductor metal device. The device is characterized by means of current voltage characteristics in the dark and under various light energies in the photon energy range of 3.70-2.15 eV. A photovoltaic effect presented by an open circuit voltage of 0.12-0.47 V. short circuit current density of 3.9-10.5 mu A/cm(2), quantum efficiency of 0.662-0.052, and responsivity of 0.179-0.024 A/W under photoexcitation optical power of 2.2-28.2 mu W is observed. The device was also tested as a UV optical communication component. The test revealed a wide range of tunability and sensitivity for microwave resonant frequencies of 0.5 and 2.9 GHz. The differential resistance of the device exhibited different values at each applied ac signal frequency. When the frequency is fixed, the illuminated to the dark current ratio remained constant for all signal powers in the range of 0.00-20.0 dBm. (C) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 14Citation - Scopus: 16Discrete Time Series-Parallel System and Its Optimal Configuration(Elsevier Sci Ltd, 2021) Dembinska, Anna; Eryilmaz, SerkanThis paper is concerned with properties of series-parallel systems when the component lifetimes have discrete failure time distribution. For a series-parallel system consisting of a specified number of subsystems, we particularly focus on the number of failed components in each subsystem at the time when the system fails. Each subsystem is assumed to have identical components while different subsystems have different types of components. Assuming all components within the system are independent, we obtain exact distributions of the number of failed components at the time when the system fails. For the special case when the components have phase-type failure time distributions, matrix-based expressions are derived for the quantities under concern. The results are used to obtain optimal configuration of the series-parallel system which is replaced at failure.Article Citation - WoS: 31Citation - Scopus: 37Effect of Initial Water Content and Calcination Temperature on Photocatalytic Properties of Tio2 Nanopowders Synthesized by the Sol-Gel Process(Elsevier Sci Ltd, 2015) Agartan, Lutfi; Kapusuz, Derya; Park, Jongee; Ozturk, AbdullahThe effects of initial water content and calcination temperature on sol gel synthesized TiO2 powders were studied. Mother solutions had water/Ti-precursor mole ratios (R ratio) of 1, 5, 10, and 50. Dried aerogels were calcined for 3 h at temperatures of 300, 400, and 500 degrees C to obtain crystallized TiO2 nanopowders in the range of 15-30 nm. PE-scanning electron microscopy and X-ray diffraction techniques were employed to investigate the morphological and structural properties of the nanopowders synthesized. Profound effect of gel viscosity was observed on the formation mechanism and extent of crystallinity in the powders. Methylene blue degradation test results suggest, photocatalytic performance is enhanced as initial water content and calcination temperature increased. Band-gap energy of the powders ranged from 3.09 to 3.27 eV. Overall, this study shows that initial water content and calcination regime have a profound effect on the phase assembly, crystallite size, band-gap energy, and photocatalytic performance of sol gel synthesized TiO2 nanopowders. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 4A Simple Method To Set the Spray Properties for Flame Spray Pyrolysis Production of Nanoparticles(Elsevier Sci Ltd, 2020) Alhaleeb, Mustafi A.; Machin, Nesrin E.The most critical part of the flame spray pyrolysis (FSP) process is the nozzle, since it plays a key role in setting the spray properties. In this study, we developed an approach to adjust the nozzle throat gap size for a desired dispersion gas flow rate and upstream pressure, based on the external size and shape of a two phase external mixing nozzle. An equation was derived and validated by comparing the predicted gas flow rates with the data provided in a commercial nozzle supplier chart. Experiments were also conducted in our lab-scale FSP reactor to test the validity of the predictions. The approach developed here was found to closely predict the gap size necessary to pass the required dispersion gas flow at a desired pressure drop. Error in predictions was found to be less than 3% at an upstream pressure range of 3-10 bars. The isentropic flow assumption for perfect gases across the convergent-divergent nozzle was found to fail below 2 bars, consistent with the theory applied. By using the method here, the nozzle setting for a desired operation in an FSP process can be easily done, minimizing the time-consuming trial and error steps needed otherwise.Article Citation - WoS: 11Citation - Scopus: 12A Multi-Domain Direct Boundary Element Formulation for Particulate Flow in Microchannels(Elsevier Sci Ltd, 2021) Topuz, Alper; Baranoglu, Besim; Cetin, BarbarosIn the present study, a multi-domain boundary element formulation is developed for high surface-area-to-volume ratio problems (i.e. particulate flow in high aspect ratio microfluidic channels, in a porous medium or in microfluidic devices with repetitive structures). The solution domain is decomposed into subdomains and the variable condensation technique is implemented. The solution matrices are built for each subdomain, and the matrices are updated at each time step only for the subdomains in which the particles move at each time step. Ghost domains, which are fictitious domains encapsulating the interfaces between the subdomains, are also introduced in the formulation to treat the particles crossing the interfaces between the subdomains. The formulation reveals that the computation of the subdomain matrices is further simplified for solution domains composed of periodic structures. The results of our study revealed that speed-up values as high as 50 is achievable with the current formulation.Article Citation - WoS: 15Citation - Scopus: 20Determination of Bacterial Community Structure of Turkish Kefir Beverages Via Metagenomic Approach(Elsevier Sci Ltd, 2022) Yegin, Zeynep; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Altunbas, Osman; Ucak, Samet; Sudagidan, MertBacterial microbiota of industrially produced kefir beverages (n:33) consumed in Turkey was studied using a culture-independent method and a metagenomic approach. DNA extraction from non pre enriched and pre-enriched kefir samples was used for 16S rRNA amplicon sequencing. Kefirs were dominated by Firmicutes, followed by Actinobacteria and Proteobacteria phyla. The most abundant genera in non pre-enriched kefir beverages were Lactococcus followed by Streptococcus, Bifidobacterium, Lactobacillus, and Leuconostoc. Pre-enriched kefirs were dominated by Streptococcus followed by Lactobacillus, Lactococcus, Bifidobacterium, and Leuconostoc at the genus level. Psychroserpens, Desulfonispora, Pediococcus, Micromonospora, Fructobacillus, Mycobacterium, Acetobacter, Pseudopedobacter, and Clostridium XI genera were found only in pre-enriched kefirs. Kefirs displayed pH differences from 4.04 to 4.49 and the acidity was 0.617e0.987. In two samples, the lowest pH values were obtained with abundance of Lactobacillus helveticus and Streptococcus salivarius. This study broadens our viewpoint and strengthens future applications of kefir beverages in industrial and medical fields. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Optimization of Parameters Acting on a Projectile Velocity Within a Four Stage Induction Coil-Gun(Elsevier Sci Ltd, 2010) Coskun, Ismail; Kalender, Osman; Ege, Yavuz; Nazlibilek, Sedat; Cokun, IsmailIn this work, a four stage induction coil-gun has been designed and the parameters acting on the bullet velocity has been investigated. The mutual inductance variation depending on the bullet coil position, determination of firing point exposed to the maximum force with respect to the length, and appropriate material selection for the bullet coil have been analyzed. Optimum solutions for these parameters have been presented. (C) 2010 Elsevier Ltd. All rights reserved.Article Citation - WoS: 24Citation - Scopus: 30Dynamic Assessment of Multi-State Systems Using Phase-Type Modeling(Elsevier Sci Ltd, 2015) Eryilmaz, SerkanMulti-state systems have attracted great attention due to their wide applications in engineering. They have been effectively used in modeling various systems such as power supply systems and transportation systems. In this paper, phase type modeling is proposed for dynamic assessment of nonrepairable multi-state systems when the system degrades According to a Markov process. The utility of phase type modeling is demonstrated in the computation of mean lifetimes, mean residual lifetimes, and derivation of survival functions of series and parallel systems. A stochastic comparison result between two systems is also obtained using phase representations of survival functions. Extensive numerical results are presented to illustrate the applicability of the approach. (C) 2015 Elsevier Ltd. All rights reserved.
