Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Ankos Publisher Application System and Its Impact on the E-Resource Evaluation Process(2013) Bulut,B.; Uğur,H.; Gürdal,G.; Holt,İ.; Çukadar,S.; Akbayrak,E.H.; Çelebi,M.K.The Publisher Application System (PAS) is a Web-based archiving and online evaluation system developed by the Database Evaluation Group (DEG), one of the working groups formed within the Anatolian University Libraries Consortium (ANKOS). The DEG was formed in 2008 to inquire and evaluate e-resources suited to the needs of the consortium; to follow up similar consortial activities worldwide as well as developments in connection with the scientific publishing industry; and to determine, implement, and improve pricing models in accordance with the prevailing economic, legal, and academic system. Development of the PAS was essential to ensure standardization and sustainability towards a more detailed and effective analysis of e-resources qualifying for evaluation by ANKOS. The PAS played an important part not only in establishing and defining the workflow of the DEG, but also in creating an archive of both the e-resources submitted to the consortium and the applicant publishers/agents submitting these resources. This article outlines the process that started with the foundation of the DEG through the formation of the PAS as well as the present setup of the system. It is also hoped that this case study will have a positive contribution to the processes being followed by the persons and the groups engaged in similar activities. © 2013 Elsevier Inc.Article Citation - WoS: 32Citation - Scopus: 37Teleoperation With Kinematically Redundant Robot Manipulators With Sub-Task Objectives(Cambridge Univ Press, 2009) Nath, Nitendra; Tatlicioglu, Enver; Dawson, Darren M.In this paper, control of nonlinear teleoperator systems where both the master and slave systems are kinematically redundant robot manipulators is addressed. The controller is developed under the assumption that the user and environmental input forces arc unmeasurable. Lyapunov-based stability analysis is used to prove that the proposed controller yields asymptotic tracking results and ensures the coordination of the master and slave systems while satisfying a sub-task objective. Numerical simulation results are presented to illustrate the effectiveness of the proposed controller.Article Citation - WoS: 11Citation - Scopus: 11Cfd Characteristics of Refrigerated Trailers and Improvement of Airflow for Preserving Perishable Foods(MDPI, 2019) Yildiz,T.When preserving perishable goods, maintaining a constant temperature over the cold supply chain is essential. Therefore, refrigerated vehicles are an important part of the cold supply chain system. However, many traditional refrigerated cargo systems are not designed to support the homogeneity of the temperature inside cargo trailers. Indeed, refrigerating equipment is usually placed on one side of transportation systems as this is considered to be more practical. Such a configuration thus leads to significant temperature differences in the two distinct parts of a refrigerated cargo trailer, which might affect the quality, safety, and shelf life of perishable foods. This research aims to improve the temperature distribution of refrigerated trailers. In this study, it is highlighted that in the most commonly used traditional refrigerated trailer models, lower air velocity and higher product temperature are observed at the rear. There is also a partial product chilling risk at the front of the refrigerated trailer. This study investigates and reports significant differences among the three airflow design models of refrigerated cargo systems by applying turbulence flow, heat, and mass transfer models. The analyses of these three models reveal that significant improvement could be achieved by applying the proper arrangements of inlets on the ceiling of the trailer body. © 2019 by the author.Article Citation - WoS: 11Citation - Scopus: 17Design and Analysis of a Lightweight Composite Shipping Container Made of Carbon Fiber Laminates(MDPI, 2019) Yildiz,T.The literature indicates that a 20% reduction in the weight of empty 40-foot shipping containers would result in $28 billion of fuel savings, along with a 3.6 exajoule reduction in the energy demand over containers’ 15-year lifetime. Decreasing the energy demand and thereby greenhouse gas emissions by utilizing lightweight shipping containers has been an unexplored strategy. In this regard, this study investigates the possibility of further reducing the weight of an empty container without compromising the structural integrity, strength, and function of a traditional steel container. This research finds that up to an 80% reduction in weight is possible by producing shipping containers with composite materials. This research presents the new design of a 40-foot container made of carbon fiber laminates. The tare weight of a traditional 40-foot shipping container is around 3750 kg. On the contrary, in this research, the weight of a composite design of the same container is calculated to be around 822 kg. Additional tests with various loads, such as lifting the container and stacking loads onto the composite container, are performed to explore the strength and buckling issues of the design presented in this study. The analyses reveal that the composite shipping container is a highly promising candidate for reducing greenhouse gas emissions, providing fuel savings and thus reducing the operational costs of transportation. © 2019 by the author.Data Paper Citation - WoS: 3Citation - Scopus: 4Experimental data showing the thermal behavior of a flat roof with phase change material(Elsevier, 2015) Tokuç, Ayça; Başaran, Tahsin; Yesügey, Sadık CengizThe selection and configuration of building materials for optimal energy efficiency in a building require some assumptions and models for the thermal behavior of the utilized materials. Although the models for many materials can be considered acceptable for simulation and calculation purposes, the work for modeling the real time behavior of phase change materials is still under development. The data given in this article shows the thermal behavior of a flat roof element with a phase change material (PCM) layer. The temperature and energy given to and taken from the building element are reported. In addition the solid-liquid behavior of the PCM is tracked through images. The resulting thermal behavior of the phase change material is discussed and simulated in [1] A. Tokuç, T. Başaran, S.C. Yesügey, An experimental and numerical investigation on the use of phase change materials in building elements: the case of a flat roof in Istanbul, Build. Energy, vol. 102, 2015, pp. 91-104.Article Citation - WoS: 69Citation - Scopus: 89Pectinase Enzyme-Complex Production by Aspergillus Spp. in Solid-State Fermentation: a Comparative Study(Elsevier, 2012) Heerd, Doreen; Yeğin, Sırma; Tarı, Canan; Fernandez Lahore, MarceloA comparative evaluation of three Aspergillus species according to their pectinase production in solid-state fermentation was performed. Solid-state fermentation offers several potential advantages for enzyme production by fungal strains. Utilization of agricultural by-products as low-cost substrates for microbial enzyme production resulted in an economical and promising process. The pectinolytic enzyme activities of two Aspergillus sojae strains were compared to a known producer, Aspergillus niger IMI 91881, and to A. sojae ATCC 20235, which was re-classified as Aspergillus oryzae. Evaluation of polymethylgalacturonase and polygalacturonase activity was performed as well as exo- vs. endo-enzyme activity in the crude pectinase enzyme-complex of the mentioned strains. Furthermore, a plate diffusion assay was applied to determine the presence and action of proteases in the crude extracts. A. sojae ATCC 20235 with highest polymethylgalacturonase activity and highest polygalacturonase activity both exo- and endo-enzyme activity, is a promising candidate for industrial pectinase production, a group of enzymes with high commercial value, in solid-state fermentation processes. Beside the enzymatic assays a protein profile of each strain is given by SDS-PAGE electrophoresis and in addition species-specific zymograms for pectinolytic enzymes were observed, revealing the differences in protein pattern of the A. sojae strains to the re-classified A. oryzae. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 21Citation - Scopus: 24Development and Mechanical Behavior of Fml/Aluminium Foam Sandwiches(Springer Verlag, 2013) Baştürk, Suat Bahar; Tanoğlu, MetinIn this study, the Fiber-Metal Laminates (FMLs) containing glass fiber reinforced polypropylene (GFPP) and aluminum (Al) sheet were consolidated with Al foam cores for preparing the sandwich panels. The aim of this article is the comparison of the flexural properties of FML/Al foam sandwich panels bonded with various surface modification approaches (silane treatment and combination of silane treatment with polypropylene (PP) based film addition). The FML/foam sandwich systems were fabricated by laminating the components in a mould at 200 A degrees C under 1.5 MPa pressure. The energy absorbtion capacities and flexural mechanical properties of the prepared sandwich systems were evaluated by mechanical tests. Experiments were performed on samples of varying foam thicknesses (8, 20 and 30 mm). The bonding among the sandwich components were achieved by various surface modification techniques. The Al sheet/Al foam sandwiches were also consolidated by bonding the components with an epoxy adhesive to reveal the effect of GFPP on the flexural performance of the sandwich structures.Article Citation - WoS: 52Citation - Scopus: 64Epitaxial Graphene Contact Electrode for Silicon Carbide Based Ultraviolet Photodetector(IOP Publishing Ltd., 2015) Kuşdemir, Erdi; Özkendir, Dilce; Fırat, Volkan; Çelebi, CemWe present the fabrication and characterization of graphene-semiconductor-graphene ultraviolet photodetector based on the rectifying character of Schottky junction at the interface between epitaxial graphene and SiC semiconductor. As-grown single layer epitaxial graphene is interdigitated as transparent conductive electrode to probe photo-generated charge carriers in a semi-insulating 4H-SiC substrate. The fabricated device exhibits the typical current-voltage characteristics of a conventional metal-semiconductor-metal type photodetector with low leakage current. Time-resolved photocurrent measurements suggest an excellent photocurrent reversibility and high response speed of the device. The measurements performed for different illumination wavelengths showed that the sample reveals higher responsivity values when it is exposed to the light with 254 nm wavelength. The obtained results imply that epitaxial graphene can be used readily as transparent conductive electrode for SiC based optoelectronic device applications.Article Citation - WoS: 8Citation - Scopus: 8Free Vibration Analysis of Damaged Composite Beams(Techno Press, 2015) Cünedioğlu, Yusuf; Beylergil, BertanIn this study, free vibration analyses of symmetric laminated cantilever and simply supported damaged composite beams are investigated by using finite element method (FEM). Free vibration responses of damaged beams are examined using Euler Bernoulli beam and classical lamination theories. A computer code is developed by using MATLAB software to determine the natural frequencies of a damaged beam. The local damage zone is assumed to be on the surface lamina of the beam by broken fibers after impact. The damaged zone is modeled as a unidirectional discontinuous lamina with 0 degrees orientations in this study. Fiber volume fraction (v(f)), fiber aspect ratio (L-f/d(f)), damage length (L-D) and its location (lambda/L), fiber orientation and stacking sequence parameters effects on natural frequencies are investigated. These parameters are affected the natural frequency values significantly.Article Citation - WoS: 19Citation - Scopus: 21Altered Conductance and Permeability of Cx40 Mutations Associated With Atrial Fibrillation(Rockefeller University Press, 2015) Cruz, Ana Santa; Meşe, Gülistan; Valiuniene, Laima; Brink, Peter R; White, Thomas W.; Valiunas, VirginijusGap junctions ensure the rapid propagation of the action potential throughout the myocardium. Three mutant forms of connexin40 (Cx40; A96S, M163V, and G38D), the primary component of the atrial gap junction channel, are associated with atrial fibrillation and retain the ability to form functional channels. We determined the biophysical properties of these mutant gap junctions in transiently transfected HeLa and N2A cells. All three mutants showed macroscopic junctional conductances over the range of 0.5 to 40 nS, and voltage dependences comparable to those of wild-type (WT) Cx40. However, the unitary conductance of G38D channels was ~1.6-fold higher than that of WT Cx40 channels (~220 vs. ~135 pS), whereas the unitary conductances of the A96S and M163V mutants were similar to that of WT Cx40. Furthermore, the M163V and G38D channels exhibited approximately two- and approximately fivefold higher permeability to the anionic dye Lucifer yellow (LY) relative to K+ (LY/K+) compared with that of WT Cx40, whereas A96S LY transfer was similar to that of WT (G38D > M163V > A96S ? Cx40WT). In contrast, G38D channels were almost impermeable to cationic ethidium bromide (EtBr), suggesting that G38D alters channel selectivity. Conversely, A96S and M163V channels showed enhanced EtBr permeability relative to WT Cx40, with the following permeability order: M163V > A96S > Cx40WT > G38D. Altered conductive and permeability properties of mutant channels suggest an essential role for Cx40-mediated biochemical and electrical coupling in cardiac tissues. The altered properties of the three single-base substitution mutants may play a role in mechanisms of reentry arrhythmias. © 2015 Santa Cruz et al.