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ÇİFTÇİOĞLU, GÖKÇEN ALEV

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Mühendislik Fakültesi

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ÇİFTÇİOĞLU

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GÖKÇEN ALEV

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Open Access
A bibliometric analysis on ircular economy of packaging
(2023-08-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Tunçok-Çeşme B., Yıldız-Geyhan E., Çiftçioğlu G. A.
Open Access
Smart agriculture through using cost-effective and high-efficiency solar drying
(ELSEVIER SCI LTD, 2020-02) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Ciftcioglu, G. A.; Kadirgan, F.; Kadirgan, M. A. N.; Kaynak, G.
Background: Challenges must be handled in an integrated manner when addressing food security and climate change. More efficient designs for food production systems, as well as their logistics, are needed in order to increase food production and to reduce emissions intensity. Specifically, any enhancements done on this purpose would contribute to mitigating climate change. Five important dimensions are being considered in smart agriculture: food security, availability, accessibility, utilization, and stability. Scope and approach: Food supply-demand chain can seriously be effected by uncontrolled population growth. Thus, any perspective to solve these uncontrolled conditions can have a positive impact. Especially giving emphasis on reduction of food losses via expoloring various ways of production, or increasing productivity, or ensuring food security are effective ways for solutions. For example, the use of solar drying for agricultural, marine or meat products is very important for preservation, thus minimizing food losses. However, traditional sun drying is a relatively slow process. Also, the product quality worsens due to several factors: microorganism growth, enzymatic reactions, insect infestations. It is known that utilizing solar energy involves several factors that need attention. Thus, a lot of effort is directed toward improving solar energy technology for drying processes. Key findings and conclusion: This study presents a smart agriculture design for drying using low cost and highly-efficient solar selective absorber. The system is based on an air heating flat plate solar absorber. Levelized cost of heat (LCOH) for the prototype using solar renewable energy is calculated and compared with the fossil fuel energy sources; natural gas, electricity, and liquified petroleum gas (LPG). In addition; a comparison of the costs for air collectors using various selective absorbers; unglazed or glazed, is presented. It is shown that solar energy, in the long run, will be more advantageous compared to fossil fuels.
Open Access
Human factors analysis by classifying chemical accidents into operations
(2023-05-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Yalçın E., Çiftçioğlu G. A., Güzel D. H. B.
In the chemical industry, organizational and operational human factors significantly contribute to accidents. Chemical accidents occur in various operations of the industry due to a range of factors. Understanding the relationship between these factors and the accidents that happen is crucial in preventing similar accidents from happening repeatedly and promoting sustainability. Therefore, this study was divided into five operations: maintenance repair, process, loading unloading, storage, and shutdown startup of the chemical industry, to provide a more concrete, intuitive explanation of the interplay between causes and illustrate the routes to failure. The data were collected from 251 accident reports from various online data. The study was analyzed using the Human Factors Analysis and Classification System (HFACS) method as a conceptual framework. Each level’s frequency variables were obtained to define nominal and ordinal data. The chi-square test and Fisher’s exact test were used in the difference analysis of data in the model. The results show that the high-frequency accidents caused under the HFACS framework were organizational processes in the process (63.73%), in the storage (70.58%), and in the shutdown startup (91.66%), and skill-based errors in the maintenance repair (81.81%) and in the loading unloading (66.03%). Furthermore, resource management, technological environment, and personal readiness were significantly correlated with the operations. Human factors have differences in different operations in the chemical industry.
Open Access
Influence of Mixed Imide Composition and Thermal Annealing on Ionic Liquid Uptake and Conductivity of Polyimide-Poly(ethylene glycol) Segmented Block Copolymer Membranes
(2021-12-09) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Ciftcioglu, Gokcen A.; Frank, Curtis W.
Understanding the impact of different bridging groups in the two-step polymerization of poly(ethylene glycol) (PEG)-incorporated polyimide (PI) materials is significant. It is known that the proton exchange membranes (PEMs) used in industry today can experience performance degradation under rising temperature conditions. Many efforts have been devoted to overcoming this problem by improving the physical and mechanical properties that extend the hygrothermal life of a PEM. This work examines the effect of oxygenated and fluorinated bridging anhydrides in the production of PI-PEG PEMs. It is shown that the dianhydride identity and the amount incorporated in the synthesis influences the properties of the segmented block copolymer (SBC) membranes, such as increased ionic liquid uptake (ILU), enhanced conductivity and higher Young’s modulus favoring stiffness comparable to Nafion 115, an industrial standard. Investigations on the ionic conductivity of PI-PEG membranes were carried out to determine how thermal annealing would affect the material’s performance as an ion-exchange membrane. By applying a thermal annealing process at 60 °C for one hour, the conductivities of synthesized segmented block copolymer membranes values were increased. The effect of thermal annealing on the mechanical properties was also shown for the undoped SBC via measuring the change in the Young’s modulus. These higher ILU abilities and mechanical behavior changes are thought to arise from the interaction between PEG molecules and ethylammonium nitrate (EAN) ionic liquid (IL). In addition, higher interconnected routes provide a better ion-transfer environment within the membrane. It was found that the conductivity was increased by a factor of ten for undoped and a factor of two to seven for IL-doped membranes after thermal annealing.
Metadata only
Analysis of electricity generation options for sustainable energy decision making: The case of Turkey
(PERGAMON-ELSEVIER SCIENCE LTD, 2020) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Yilan, Gulsah; Kadirgan, M. A. Neset; Ciftcioglu, Gokcen A.
Sustainable energy decision making requires the comparison of energy generation technologies regarding a wide range of economic, technical, environmental, and socio-economic criteria. This study aims to rank the main seven electricity generation technologies for Turkey according to their performance scores. These energy generation technologies are natural gas, coal, hydropower with dam, run-of-river type hydropower, onshore wind, geothermal and solar PV. The sustainability scores are calculated via twelve indicators classified into abovementioned four criteria groups. Multi-criteria decision analysis methodology is employed with a weighted sum multi-attribute utility approach for five different sensitivity cases. The results reveal that the hydroelectric technology with dam is the best option for most of the sensitivity cases. We hope this study gives a scientific and objective standpoint to decision-maker authorities in Turkey for planning sustainable electricity generation policies. (C) 2019 Elsevier Ltd. All rights reserved.
Open Access
Human reliability analysis methods
(2023-05-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Yalçın E., Çiftçioğlu G. A., Güzel B. H.
Open Access
Effect of Increased Ionic Liquid Uptake via Thermal Annealing on Mechanical Properties of Polyimide-Poly(ethylene glycol) Segmented Block Copolymer Membranes
(MDPI, 2021-04-08) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Ciftcioglu, Gokcen A.; Frank, Curtis W.
Proton exchange membranes (PEMs) suffer performance degradation under certain conditions-temperatures greater than 80 degrees C, relative humidity less than 50%, and water retention less than 22%. Novel materials are needed that have improved water retention, stability at higher temperatures, flexibility, conductivity, and the ability to function at low humidity. This work focuses on polyimide-poly(ethylene glycol) (PI-PEG) segmented block copolymer (SBC) membranes with high conductivity and mechanical strength. Membranes were prepared with one of two ionic liquids (ILs), either ethylammonium nitrate (EAN) or propylammonium nitrate (PAN), incorporated within the membrane structure to enhance the proton exchange capability. Ionic liquid uptake capacities were compared for two different temperatures, 25 and 60 degrees C. Then, conductivities were measured for a series of combinations of undoped or doped unannealed and undoped or doped annealed membranes. Stress and strain tests were performed for unannealed and thermally annealed undoped membranes. Later, these experiments were repeated for doped unannealed and thermally annealed. Mechanical and conductivity data were interpreted in the context of prior small angle X-ray scattering (SAXS) studies on similar materials. We have shown that varying the compositions of polyimide-poly(ethylene glycol) (PI-PEG) SBCs allowed the morphology in the system to be tuned. Since polyimides (PI) are made from the condensation of dianhydrides and diamines, this was accomplished using components having different functional groups. Dianhydrides having either fluorinated or oxygenated functional groups and diamines having either fluorinated or oxygenated diamines were used as well as mixtures of these species. Changing the morphology by creating macrophase separation elevated the IL uptake capacities, and in turn, increased their conductivities by a factor of three or more compared to Nafion 115. The stiffness of the membranes synthesized in this work was comparable to Nafion 115 and, thus, sufficient for practical applications.
Open Access
Environmental Life Cycle Assessment of Two Types of Flexible Plastic Packaging under a Sustainable Circular Economy Approach
(2024-04-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Tunçok-Çeşme B., Yıldız-Geyhan E., ÇİFTÇİOĞLU G. A.
While it is of great importance to evaluate plastic waste within the framework of a circular economy today, it is also of great importance to evaluate flexible plastic packaging, which is increasingly used in order to prevent environmental problems. To avoid the disadvantages experienced in recycling due to its multilayer nature, in this study, a life cycle assessment was made for flexible packages consisting of PET/metallized PET/PE and PP/metallized PP/PP with the data provided by the R&D Center of Elif Plastik Ambalaj Sanayi ve Tic. A.¸S.-Huhtamaki Flexibles Istanbul. Within the scope of this evaluation, two types of flexible packaging were analyzed, and an optimal flexible packaging structure for Türkiye was revealed by comparing different scenarios based on different methods in SimaPro 8.1.1.16. LCA was performed for both packages with cumulative energy demand (CED) and CML-IA methods. Four scenarios with different amounts of recycled raw materials were compared against the existing system and a fifth scenario, where electricity is assumed to be obtained from solar energy. Overall, we found that the largest environmental impact was in the existing system. However, despite being a renewable energy source, we observed that the solar energy scenario had almost as significant an impact as the existing system. When scenarios involving recycled raw materials were examined, we clearly observed that as the amount of recycled raw materials increased, the environmental impact decreased. Therefore, it emerged that the scenario with the highest amount of recycled raw materials is the most optimal scenario in many respects. There are clear differences in the results due to differences in plastic types. This study, conducted with real data, is highly important for the flexible packaging literature. A table has been provided for changing the type of plastic, changing the source of electricity generation, and reducing waste by using recycled raw materials in order to make flexible packaging more environmentally beneficial. Keywords: circular economy; LCA; life cycle assessment; flexible packaging; environmental life cycle assessment (ELCA); SimaPro; sustainability
Open Access
The evaluation of vapor cloud explosion risk through consequence analysis approach for an LPG filling terminal in Turkey Türkiye'de bir LPG dolum terminali için buhar bulutu patlama riskinin sonuç analizi yaklaşimi ile deǧerlendirilmesi
(2024-01-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Çalik F., ÇİFTÇİOĞLU G. A., Kadirgan M. A. N.
The Consequence analysis modeling approach refers to the risk analysis method that quantitatively evaluates the effect of physical damage to be caused by flammable chemicals in the chemical process industry on the plant equipment, structures in and around the plant, the environment and living things after the loss of integrity scenarios. This study minimizes uncertainties such as release cross-section, flammable gas cloud mass, congestion geometry and DDT (deflagration to detonation transition) assessment, fuel reactivity involved in the traditional approach discussed in the literature and presents a conservative systematic procedure. This consequence analysis modelling based on near-miss LPG dispersion that have happened approximately 15 minutes in July 2017 at an LPG filling facility. The damage parameters caused by explosive LPG cloud mass in the defined scenarios were analyzed in ALOHA software. The overpressure outputs were transfered to GIS-based Marplot software and were estimated damage on sensitive locations caused by explosion overpressure through probit functions. The probit equations used in this study for building damage estimations put all buildings in the same category. The different reinforcement and physical properties of the buildings make it difficult to reach accurate estimates for possible structural damage. In addition, this study is a pre-assessment on the dimensions of the explosion risk due to the uncertainties and assumptions contained in the method. At the decision-making stage for the facility investment plans should make more comprehensive analysis.
Open Access
Validity and reliability study of charity hazard scale
(2023-11-01) ÇİFTÇİOĞLU, GÖKÇEN ALEV; Özkan A. H., Çiftçioğlu G. A., Güzel H., Başol O.
Safety culture, which enables people to think proactively, is a concept that is still developing in Turkey. From a disaster management point of view, the concept of safety culture provides the formation of a culture covering the implementation of the risk management phase. Therefore, it is possible to state that the concept of charity hazard poses a serious threat to the safety culture. Thus, the concept of charity hazard is of great importance in the formation of safety culture in the fields of occupational health and safety, emergency aid and disaster management. In this context, the present study aims to develop a valid and reliable scale for the concept of charity hazard. As a result of the analyses conducted with 532 participants residing in different cities across Turkey and working in different fields; the factor loadings of the items in the scale ranged between 0.51 and 0.95 and the total variance explained was calculated as 63.244 %. According to the results of the confirmatory factor analysis, the charity hazard scale consists of 3 factors and 10 items (X2/df = 2.346, RMSEA: 0.050, SRMR: 0.048, NFI: 0.97, NNFI: 0.97, CFI: 0.98, GFI: 0.97, AGFI: 0.95). The internal consistency of the scale was calculated as 0.758 and item-total correlations ranged between 0.318 and 0.554. In conclusion, the analyses show that the charity hazard scale developed is a valid and reliable measurement tool.