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Article Citation - WoS: 11Citation - Scopus: 20The Taylor Series Method and Trapezoidal Rule on Time Scales(Elsevier Science inc, 2020) Georgiev, Svetlin G.; Erhan, Inci M.The Taylor series method for initial value problems associated with dynamic equations of first order on time scales with delta differentiable graininess function is introduced. The trapezoidal rule for the same types of problems is derived and applied to specific examples. Numerical results are presented and discussed. (c) 2020 Elsevier Inc. All rights reserved.Article Citation - WoS: 27Citation - Scopus: 28Generalized Meir-Keeler Type Contractions on g-metric Spaces(Elsevier Science inc, 2013) Mustafa, Zead; Aydi, Hassen; Karapinar, ErdalIn this manuscript, we introduce generalized Meir-Keeler type contractions over G-metric spaces. Moreover, we show that every orbitally continuous generalized Meir-Keeler type contraction has a unique fixed point on complete G-metric spaces. We illustrate our results by some given examples. (C) 2013 Elsevier Inc. All rights reserved.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.Article Citation - WoS: 6Citation - Scopus: 10Male and Female Differences in the Use of Social Media for Learning Purposes(Routledge Journals, Taylor & Francis Ltd, 2018) Akman, Ibrahim; Turhan, CigdemThis study aims to explore the differences between male and female users' behaviour with regard to acceptance of social media for learning in higher educational institutions. For this purpose, a survey was conducted and the least square regression analysis approach was utilised to investigate the relationships among the constructs in the research model for male and female users from a general and ethical perspective, focusing on the reliability, performance and awareness factors. The findings from the analysis reveal that a significant degree of diversity is present in the factors represented by general reliability', ethical reliability', ethical performance', ethical awareness' and ethical intention'.Article Effectiveness of Boric Acid in Sepsis in Rats With Cecal Perforation(Springer Nature, 2025) Kurtipek, Ali Can; Dursun, Ali Dogan; Yigman, Zeynep; Ozdemir, Cagri; Kucuk, Aysegul; Gonullu, Ugur; Arslan, MustafaIntroduction and AimSepsis is a systemic inflammatory response that develops in the host against microorganisms, which results in end-organ damage. Boric acid (BA) has been shown to have immune modulatory effects in vitro and in animal studies. The aim of the study is to investigate the effects of high dose BA on lung and kidney tissues in rats with sepsis induced by the CLP method.Method28 rats were randomly divided into four groups: Group C (control group), Group BA, Group CLP (cecal ligation and puncture), and Group CLP + BA. Cecum was ligated below the ileocecal valve and punctured. BA was administered to the treatment groups at an intraperitoneal dose of 200 mg/kg, and at the end of 24 h, lung and kidney tissue samples were collected and evaluated for biochemical and histopathological parameters.ResultsHistopathologically, in kidney tissue, CLP + BA group showed significantly less peritubular capillary dilatation and brush border loss in the proximal tubule epithelium compared to the CLP group. In lung tissue, CLP + BA group had significantly less alveolar wall thickening compared to the CLP group. Biochemical analyses indicated that BA administration reduced oxidative stress in both renal and lung tissues.ConclusionWe found that intraperitoneal administration of high dose boric acid partially ameliorated the tissue damage in rats subjected to CLP induced sepsis. Further studies are needed regarding the dosage and application at different time points.Article Citation - WoS: 17Citation - Scopus: 24Optimization and Energy Analysis of a Novel Geothermal Heat Exchanger for Photovoltaic Panel Cooling(Pergamon-elsevier Science Ltd, 2021) Jafari, Rahim; Jafari, Rahim; Jafari, Rahim; Automotive Engineering; Automotive EngineeringElectrical energy and conversion efficiency of the photovoltaic (PV) solar panels are measured under standard test conditions in some microseconds at the room temperature (25 degrees C). It also is seen that the actual working conditions, on the other hand, with higher ambient temperature and continuous generated heat in the PV cells can lead to reduction in reduce their electricity generation and long-term sustainability. In the current work, the coolant (water + ethylene glycol) circulates between two heat exchangers; the minichannel heat exchanger is bounded to the PV cells and geothermal heat exchanger is buried underground, and it is set to remove the heat from PV cells to the ground. Six control factors of the geothermal cooling system are considered for the purpose of optimization using Taguchi design and main effect analysis. These parameters are pipe length, soil thermal conductivity, coolant flow rate, adjacent coil distance, pipe inner diameter and pipe thickness. The experimental results show that the average net electricity generation of the cooled PV panel is improved 9.8% compared to the PV panel without cooling system. However, with the same geothermal heat exchanger it drops to 6.2% as the cooled panel number is doubled. The simulation results reveal that the optimum configuration of the geothermal cooling system is capable of enhancing the net electricity generation of the twin cooled panels up to 11.6%. The LCOE of the optimized geothermal cooling system was calculated 0.089 euro/kWh versus the reference panel of 0.102 euro/kWh for the case study of 30 kW PV solar plant.Article Citation - WoS: 5Citation - Scopus: 6Clinic-Oriented Injectable Smart Material for the Treatment of Diabetic Wounds: Coordinating the Release of Gm-Csf and Vegf(Elsevier, 2024) Kinali, Hurmet; Kalaycioglu, Gokce Dicle; Boyacioglu, Ozge; Korkusuz, Petek; Aydogan, Nihal; Vargel, IbrahimChronic wounds are often caused by diabetes and present a challenging clinical problem due to vascular problems leading to ischemia. This inhibits proper wound healing by delaying inflammatory responses and angiogenesis. To address this problem, we have developed injectable particle-loaded hydrogels which sequentially release Granulocyte-macrophage- colony-stimulating-factor (GM-CSF) and Vascular endothelial growth factor (VEGF) encapsulated in polycaprolactone-lecithin-geleol mono-diglyceride hybrid particles. GM-CSF promotes inflammation, while VEGF facilitates angiogenesis. The hybrid particles (200 -1000 nm) designed within the scope of the study can encapsulate the model proteins Bovine Serum Albumin 65 +/- 5 % and Lysozyme 77 +/- 10 % and can release stably for 21 days. In vivo tests and histological findings revealed that in the hydrogels containing GM-CSF/VEGF-loaded hybrid particles, wound depth decreased, inflammation phase increased, and fibrotic scar tissue decreased, while mature granulation tissue was formed on day 10. These findings confirm that the hybrid particles first initiate the inflammation phase by delivering GM-CSF, followed by VEGF, increasing the number of vascularization and thus increasing the healing rate of wounds. We emphasize the importance of multi-component and sequential release in wound healing and propose a unifying therapeutic strategy to sequentially deliver ligands targeting wound healing stages, which is very important in the treatment of the diabetic wounds.Article Citation - WoS: 4Citation - Scopus: 6A Team-Oriented Course Development Experience in Distance Education for Multidisciplinary Engineering Design(Wiley, 2022) Say, Bilge; Erden, Zühal; Erden, Zuhal; Turhan, Cihan; Turhan, Cihan; Say, Bilge; Erden, Zühal; Turhan, Cihan; Say, Bilge; Energy Systems Engineering; Software Engineering; Mechatronics Engineering; Energy Systems Engineering; Mechatronics Engineering; Software EngineeringBased on the multidisciplinary needs of today's complex and innovative technology, accreditation bodies of engineering demand proof of multidisciplinary teamwork in undergraduate engineering curricula. This article reports the design and conduct of a Multidisciplinary Engineering Design (MED) course initiated as a result of accreditation process requirements. The course, which consists of multidisciplinary lectures, practice sessions, and various phases of a multidisciplinary team project, was conducted online because of the COVID-19 pandemic by a multidisciplinary team of instructors using multiple software tools to enhance collaboration. In general, the course outcomes were satisfied under the current design, and several points for further improvement and elaboration were collected via quantitative and qualitative evaluations. Accordingly, the results show that the project-based and team-based MED course, in terms of multidisciplinary course management and its outcomes, can benefit from the use of software tools in creating a multidisciplinary team in distance education by means of enhanced cooperation and motivation among the participants.Article Citation - WoS: 25Citation - Scopus: 25A Model for the Prediction of Thermal Runaway in Lithium-Ion Batteries(Elsevier, 2024) Azuaje-Berbeci, Bernardo J.; Ertan, H. BulentThe increasing popularity of electric vehicles is driving research into lithium -ion batteries (LIBs). Thermal runaway (TR) in LIBs is a serious concern for the safe operation of these high-energy-density batteries that is yet to be overcome. A reliable model is needed to predict voltage variation, heat generation, temperature rise, and the process leading to TR of a LIB battery under its operating conditions (charging-discharging). Such a model can be used to design battery packs more resilient to thermal runaway or assess how a battery pack would perform under hazardous conditions. Furthermore, it can be used for generating a warning signal if there is a possibility of the battery going towards TR. This paper presents an approach to solving this problem, which is not currently well addressed in the literature. The approach adopted in this paper is based on a numerical analysis of a multilayered electrochemical-thermal model of LIB. Tuning the parameters of a LIB for accurate results from this numerical model is presented, as well as the details of the approach in the paper. Experiments are performed under several LIBs, and their voltage and surface temperature variations are measured under various operating conditions, including thermal runaway. The results of the experiments are compared with the predictions of the numerical simulations. An excellent agreement is observed with the experimental results, proving the accuracy of the proposed approach. This approach can be configured to give results in a few minutes. The paper also discusses how the developed approach can be used to create a TR warning during operating conditions or to change the mode of operation of a LIB before a hazard occurs.Article Citation - WoS: 42Citation - Scopus: 42Sol-Gel Synthesis and Photocatalytic Activity of B and Zr Co-Doped Tio2(Pergamon-elsevier Science Ltd, 2013) Kapusuz, Derya; Park, Jongee; Ozturk, AbdullahEffects of boron (B) and/or zirconium (Zr) doping on photocatalytic activity of sol-gel derived titania (TiO2) powders were investigated. A conventional, non-hydrous sol-gel technique was applied to synthesize the B, Zr doped/co-doped TiO2 powders. Doping was made at molar ratios of Ti/B=1 and Ti/Zr=10. Sol-gel derived xero-gels were calcined at 500 degrees C for 3 h. The crystal chemistry and the morphology of the undoped and B, Zr doped/co-doped TiO2 nanoparticles were investigated using X-ray diffractometer and scanning electron microscope. Nano-scale (9-46 nm) TiO2 crystallites were obtained after calcination. Doping and co-doping decreased the crystallite size. Photocatalytic activity was measured through the degradation of methylene blue (MB) under 1 h UV-irradiation using a UV-vis spectrophotometer. Results revealed that B doping into anatase caused the formation of oxygen vacancies, whereas Zr addition caused Ti substitution. Both B and Zr ions had a profound effect on the particle morphology and photocatalytic activity of TiO2. The photocatalytic activity of B and Zr doped TiO2 particles increased from 27% to 77% and 57%, respectively. The best activity (88.5%) was achieved by co-doping. (C) 2013 Elsevier Ltd. All rights reserved.
