TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Citation - WoS: 7Citation - Scopus: 8Ascorbic Acid Enhances the Metabolic Activity, Growth and Collagen Production of Human Dermal Fibroblasts Growing in Three-Dimensional (3D) Culture(Gazi Üniversitesi, 2023) Dikici, Serkan; Dikici, Serkan; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyTissue engineering (TE) enables the development of functional synthetic substitutes to be replaced with damaged tissues and organs instead of the use of auto or allografts. A wide range of biomaterials is currently in use as TE scaffolds. Among these materials, naturally sourced ones are favorable due to being highly biocompatible and supporting cell growth and function, whereas synthetic ones are advantageous because of the high tunability on mechanical and physical properties as well as being easy to process. Alongside the advantages of synthetic polymers, they mostly show hydrophobic behavior that limits biomaterial-cell interaction and, consequently, the functioning of the developed TE constructs. In this study, we assessed the impact of L-Ascorbic acid 2-phosphate (AA2P) on improving the culture conditions of human dermal fibroblasts (HDFs) growing on a three-dimensional (3D) scaffold made of polycaprolactone (PCL) using emulsion templating. Our results demonstrated that AA2P enhances the metabolic activity and growth of HDFs as well as collagen deposition by them when supplemented in their growth medium at 50 µg/mL concentration. It showed a great potential to be used as a growth medium supplement to circumvent the disadvantages of culturing human cells on a synthetic biomaterial that is not favored in default. AA2P's potential to improve cell growth and collagen deposition may prove an effective way to culture human cells on 3D PCL PolyHIPE scaffolds for various TE applications.Article Eğitim yapılarında asansör trafik analizi yöntemlerinin karşılaştırılmasına yönelik bir araştırma(Gazi Üniversitesi, 2023) Deligöz, Dostcan; Harputlugil, Timuçin; 01. Izmir Institute of TechnologyPurpose: Regarding elevator design in educational buildings; It is aimed to investigate the legal framework, to integrate dynamic simulation programs to design process, to compare traditional and dynamic simulation methods, to evaluate the adequacy of elevator features specified in the legislation and to determine the optimum scenarios according to the minimum requirements.Theory and Methods: Based on the findings of the literature review, which examines the issue of elevator traffic analysis together with the legislation and regulations, the carrying capacities of the elevators in the educational buildings designed by the Ministry of National Education (MNE) are tested. The stability of the system is tested by analyzing the conditions where only the disabled, disabled and building workers can be used together and all building users can use the elevators with the dynamic simulation method (with Elevate Software). The limits of the system are determined based on the waiting times during the peak usage periods. The findings of the study are evaluated according to the waiting times determined by CIBSE Guide D and the Chamber of Mechanical Engineers followed by the discussion of the outcomes.Results: The issue of elevator design has been overlooked in educational buildings, and a comprehensive elevator traffic analysis method has not been defined. For the effective use of all occupants, elevator design should be handled comprehensively with considering potentials of dynamic simulation method.Conclusion: According to the findings of the study, it is noted that the number and capacity of elevators in the legislation for educational buildings are determined only for minimum conditions and for disabled users. In addition, the legislation (considering calculation methodology) is not specific for educational buildings but related with buildings in general with public use. Considering the occupants, and their profiles of the educational buildings, a more comprehensive traffic analysis with the dynamic simulation method may enable the elevators to be designed and to be used more efficiently.Article Citation - WoS: 3Boşluk İletim Tabakasız ve Esnek Organo Kurşun İyodür Perovskit Güneş Hücresinin Çevresel Etki Değerlendirmesi(Gazi Üniversitesi, 2022) Sarıaltın, Hüseyin; Sarıaltın, Hüseyin; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPerovskit güneş pilleri (PSC) esneklik ve düşük maliyetli rulodan ruloya üretim gibi avantajlarla birlikte son zamanlarda güç dönüşüm verimliliğinde de önemli bir ilerleme kat etmiştir. PSC'lerin ticarileştirilmesinden önce çevresel performansının yaşam döngüsü değerlendirme (LCA) yöntemi ile araştırılması önemlidir. Bu çalışmada, literatür verilerinden istifade edilerek, esnek Polietilen tereftalat (PET) alt tabaka ve boşluk iletim katmanı (HTL) eliminasyonunu içeren çözelti bazlı organo-kurşun iyodür perovskit güneş hücresinin beşikten kapıya yaşam döngüsü analizi (LCA) gerçekleştirilmiştir. 1 m2 hücre alanı üretiminden kaynaklanan çevresel etkiler altı Uluslararası Referans Yaşam Döngüsü Veri Sistemi (ILCD) kategorisinde belirlenmiştir. Analizin sonucunda, en fazla etki değerinin yüksek elektrik enerjisi tüketimine sahip vakum biriktirme işlemi gereksinimine sahip olan alüminyum metal elektrot tabakasının imalatından kaynaklandığı bulunmuştur. Ticari fotovoltaik teknolojilerle karşılaştırma yapabilmek için en yaygın kullanılan çevresel göstergelerden birisi olan küresel ısınma potansiyeli (GWP), birim kWh elektrik üretimi için hesaplanmıştır. Buna göre, bu çalışmada incelenen HTL'siz esnek (HFF) PSC'nin ticari PV'lerle rekabetçi GWP değerine ulaşmak için 15-20 yıl cihaz ömrüne ihtiyacı olduğu bulunmuştur.Article Citation - WoS: 1Citation - Scopus: 1Fragility Analysis of Wide-Beam Infill-Joist Block Rc Frames(Gazi Üniversitesi, 2022) Dönmez, Cemalettin; Dönmez, Cemalettin; Erberik, Murat Altuğ; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPurpose: The purpose of the presented study is to develop fragility curves for the wide-beam infill-joist block reinforced concrete structures. Theory and Methods: Nonlinear time history analyses are performed for the set of selected ground motions. The performance levels are identified through pushover analysis and fragility curves are produced for ground motion parameters. Results: Fragility curves obtained for the wide-beam RC frames presents a different characteristic than the curves obtained for the conventional frames. Conclusion: Results show that wide-beam RC frame buildings are seismically more vulnerable than the conventional deep beam RC frame buildings based on structural models with similar properties. The possible reason seems to be low lateral stiffness of wide-beam frames that causes large lateral drift demands and therefore severe damage at the wide-beam column connections.Article Citation - WoS: 1Performance Analysis of Thermal Storage Assisted Cooling Tower With Night Cooling(Gazi Üniversitesi, 2020) Ouedraogo, Kiswendsida Elias; Toprak, Kasım; Toprak, Kasım; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAs global warming and water scarcity issues continue to grow, it is essential to increase resources efficiency for air conditioners and power plants. In order to increase the efficiency, the systems need to be modified to take the advantages of the low night temperature and thermal storage tanks. In this study, the low night temperature and thermal storage tanks effects on the cooling tower is studied using TRNSYS. Using a chiller operating from 8:00 to 16:00 as a case study, hot water from the condenser is partially stored on daytime and cooled slowly during the night. The storage tank volume is optimized by considering two big tanks and five small tanks. The results show that night cooling reduces cooling water temperature by 5.8 degrees C or 21.8% while the cooling efficiency is increased by 36%. The thermal storage tanks enable to have the low continuous flow rate and help to reduce the fan power by 67.1%. On the storage side, compared to two tanks system, the tanks volume is reduced by 16.5% when 5 tanks are used. In theory this reduction can go up to 50% by increasing the number of tanks and reducing their individual size.Article Privacy Issues on Social Networks(Gazi Üniversitesi, 2018) Şahin, Serap; Şahin, Serap; 03.04. Department of Computer Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe privacy is a need for humanity since the creation of civilizations. In social networks the common point is that each user has to create a profile to define his or her own identity. The profile description includes many items with privacy settings to tune their visibility degrees for only owner, friends, friends of friends and sometimes for public. After enrolment stage, users extend their social connection graphs with accepted new friends and these graphs grow without the control of individual due to the new friends of friends. Hence, with high probability, the shared information of member is generally available to public and can be retrieved by users around the world. This article is prepared to give an overview on the reasons of privacy concerns and risks of SNs, and summarize the current and future possible solution directions for researchers and governments.Article Citation - WoS: 7Inertia and Droop Controller for a Modern Variable Speed Wind Turbine To Provide Frequency Control in a Microgrid(Gazi Üniversitesi, 2020) Hassan, Ali; Bingöl, Ferhat; Altın, Müfit; Altın, Müfit; Bingöl, Ferhat; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe increasing penetration of modern Variable Speed Wind Turbines (VSWTs) in microgrids creates the problem of frequency stabilization due to reduced inertia of the power system. To emulate the Inertia Response of the conventional synchronous machines, wind turbines can be provided with an inertia emulation controller. The modeling presented in this paper aims at equipping the modern Type D wind turbine with inertia response and primary frequency control (PFC) capabilities. Two controllers - inertial and droop, are implemented and their frequency control capabilities are compared in an isolated power system which consists of a conventional steam turbine generator and a wind farm. The results suggest that proposed controllers help in better frequency control performance in the microgrid.