Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Optimizing Inhibitor Injection in Geothermal Wells With Electrical Submersible Pump(Elsevier Ltd, 2025) Aydin, H.; Tezel, S.I.; Erol, S.Electrical submersible pump (ESP) is a reliable artificial lift method to extend productive lifespan of geothermal wells. In the geothermal industry a common practice involves installing ESPs below the well's flashing depth. This placement approach aims to mitigate the risk of mineral precipitation, which can occur when hot geothermal fluids transition to a two-phase state (liquid and vapor) as pressure decreases. Positioning the pump below the flashing depth also prevents pump's underloading and gas cavitation. The inhibitor injection line usually integrated around the ESP string and installed downstream of the ESP motor. However, this standard practice introduces a challenge regarding inhibitor performance. While this placement ensures effective distribution of inhibitors throughout the production flow, the extended travel time from the surface to the point of application at the ESP can diminish inhibitor effectiveness due to continuous exposure to high temperatures throughout the wellbore. This study proposes relocating the inhibitor injection point within the production tubing closer to the flashing depth. This reduces inhibitor travel time from 108 min to 48 min and has the potential to significantly improve inhibitor effectiveness. Consequently, the implementation of capillary tubing is anticipated to yield annual cost savings per wellbore of approximately USD 10,000, coupled with the mitigation of mineral deposits within the studied well equipped with ESP. To evaluate this approach, a wellbore simulation tool and PHREEQC were employed to dynamically model the pressure and temperature profiles alongside the geochemical evolution of the produced fluids in the wellbore. This modeling approach offers significant value by potentially enabling the optimization of inhibitor usage and reducing the length of required inhibitor injection line. © 2024 Elsevier LtdArticle Citation - Scopus: 6Lithium Extraction From Geothermal Brine Using Γ-Mno2: a Case Study for Tuzla Geothermal Power Plant(Elsevier Ltd, 2024) Toprak, S.; Yılmaz, Selahattin; Öncel, Ç.; Baba, Alper; Yılmaz, S.; Demir, Mustafa Muammer; Baba, A.; Koç, G.A.; Demir, M.M.Geothermal brines contain high concentrations of ions and form a source of various valuable elements. The isolation of the elements from their water systems is a great challenge when the gradual depletion of ores in mining is considered. Attempts have been made for a long time to isolate valuable elements from aqueous mixtures prepared in the laboratory. However, those studies might not reflect the complexity of natural systems and might yield results that deviate significantly from the performance in real field systems. In this study, sorption is used to extract lithium ions from a representative field, Tuzla Geothermal Power Plant (TGPP) Turkey, using a mini-pilot reactor introduced to the reinjection well of the plant. Electrolytic manganese dioxide (γ-MnO2), a relatively inexpensive material widely used as the cathode material in lithium-ion batteries, was employed as a sorbent material for lithium. The sorption/desorption performance of the novel γ-MnO2 was investigated under various conditions. Sorption is performed at 360K and 2 bars. The maximum sorption performance was obtained at 1 h in Tuzla GPP. The desorption experiments were performed in acidic solutions. The concentration of Li+ in the desorption solution was found to be 25 mg/L on average when 10 g of γ-MnO2 was dispersed into 30 mL of the acidic aqueous solution. The first desorption solution was used consecutively for collecting more Li+ ions through the desorption of fresh brine-treated powder samples (cumulative desorption). By repeating this process four times consecutively, 230 mg/L of Li+ was obtained in the desorption solution. Moreover, the reusability of the γ-MnO2 sorbent was examined. The sorbent powder showed almost 40% performance efficiency compared to virgin powder under the conditions employed in this study. The use of electrolytic γ-MnO2 sorbent for lithium adsorption was found to be a promising process for practical use in the separation of lithium from geothermal brines. © 2024Article Citation - Scopus: 13Modification of Pea Protein Isolates by High-Intensity Ultrasonication: Functional, Structural and Nutritional Properties(Elsevier Ltd, 2024) Ozkan,G.; Tataroglu,P.; Gulec,S.; Capanoglu,E.The current study aims to modify the functional, physical, structural and nutritional characteristics of pea protein isolate. High-intensity ultrasound treatment was used at 20 kHz frequency and 25 % amplitude for 10 (US10), 20 (US20), or 30 (US30) min. Results indicated that ultrasound application enhanced the protein solubility and zeta potential. When compared to control samples, the foaming capacity (FC) and stability (FS) as well as emulsion activity (EA) and stability (ES) were also increased from 157.5, 42.03, 46.25 and 53.75 % up to 182.5, 81.57, 72.50 and 67.50 %, respectively. Besides, particle size was found to be lower for ultrasound treated samples (92.9–131.1 nm) in comparison to that of untreated commercial pea protein isolate (161.9 nm). Moreover, while the bioaccessibility of pea protein in untreated sample was calculated as 28.90 %, ultrasonication increased the retention of pea protein up to 49.36 %. It can be concluded from the results that the ultrasonication process can be used as an advantageous, green and non-thermal tool for obtaining protein isolates with improved techno-functional properties and nutritional quality. Therefore, this treatment might improve the characteristics, and thus increase the utilization of plant-based proteins, especially pea protein, in various food systems. © 2024Conference Object Citation - Scopus: 2Influence of Non-Uniform Noise Levels on Modal Identification Procedures(Elsevier Ltd, 2021) Hızal,Ç.; Ceylan,H.Considerable deficiencies and errors in measurement systems are frequently encountered in vibration based structural health monitoring (SHM) applications. Some SHM algorithms are capable of considering such kinds of problems as prediction errors and/or sensor channel noise. As a general intention, however, either a uniform channel noise distribution is assumed or the corresponding measurement channel which produces significant noise in the measured data is generally omitted by researchers. From this perspective, this paper presents a comparative study to investigate the performance of two different SHM algorithms in case of non-uniform sensor channel noise spectral densities. In this context, first the considered problem is illustrated based on the disruptions in the spectral coherence between the noisy and noise free data. Then, a numerical example is presented in which the modal identification of a three degree-of-freedom (DoF) system is performed by using Bayesian Fast Fourier Transform Approach (BFFTA) and Covariance-based Stochastic Subspace Identification (SSI–COV). Results show that both techniques can be adversely affected by the non-uniform levels of channel noise. However, SSI–COV performs better in this case. © 2021Article Citation - WoS: 3Citation - Scopus: 3Where Do Temporary Urban Design Interventions Fall on the Spectrum of Public Participation? an Analysis of Global Trends(Elsevier Ltd, 2024) Doğu,T.; Mengi,O.; Köse,S.Urban environments profoundly shape human life, yet rapid urbanization often overlooks social challenges, hindering the development of cohesive communities. To address these challenges, contemporary practices are embracing participatory design approaches globally, resulting in a growing trend towards temporary urban design interventions (TUDIs) that catalyze shifts in how people interact with cities. While scholarly research explores the relationship between participation and social change, it offers significant potential for raising questions about such connection: Where do TUDIs fall on the spectrum of public participation? How would a comprehensive framework be formulated to evaluate such interventions regarding public participation and social change? What are the design processes and design outcomes of these interventions? This study examines the relationship between participation and social change in the context of TUDIs, via a meta-analysis of the literature and practice, to devise a methodological framework that integrates a variety of components involved in urban design projects worldwide. The framework informs urban design theory and practice about TUDIs through the lens of participation, while simultaneously underlining their value as a strategic tool for socially integrated cities. © 2024 Elsevier LtdArticle Citation - WoS: 5Citation - Scopus: 5Rethinking Planning and Nature Conservation Through Degrowth/ Post-Growth Debates(Elsevier Ltd, 2024) Avar,A.A.; Cive,Y.Ö.Based on the critical debates in urban theory, political ecology and urban political ecology literature, this article interrogates the potentialities and limitations of degrowth/post-growth planning, regarding relational, non-dualistic and multi-scalar spatialization of nature conservation. It firstly reveals that pragmatic, technoscientific and “sustainable/ecological urbanism” and market-based nature conservation it incorporates exacerbate socio-ecological crises and socio-spatial inequalities in and beyond cities under the conditions of planetary urbanisation. Second, it interrogates how new market-based nature conservation turned into 'green-grabbing' and primitive accumulation. Having explored the degrowth or post-growth approach in relation to other radical nature conservation approaches (e.g., convivial conservation and global safety network), it interrogates the ways in which post-growth planning deals with socio-spatial aspects of nature conservation. It takes the “degrowth/ post-growth planning” both as an instrument to spatialize radical nature conservation and as an approach addressing socio-ecological injustices and inequalities intersecting at multiple scales. It concludes that the degrowth/ post-growth planning can overcome its limitations and advance its potentialities, drawing from already existing radical conservation and critical approaches in neighbouring disciplines as well as the discipline itself. © 2024 Elsevier LtdArticle Citation - WoS: 8Citation - Scopus: 9Modelling and Analysis of Heat Pump Integrated Photovoltaics-Wind Systems for an Agricultural Greenhouse in Turkey(Elsevier Ltd, 2024) Ozcan,Z.; Bilir,L.; Caglar,B.This study focused on modelling and analysing photovoltaics and wind systems to meet the heating demand of a commercial greenhouse. The aim is to evaluate technical, economic, and environmental performances of the related systems and to determine the optimum configuration. A novel approach was introduced by integrating hybrid energy systems with large-scale wind turbines and developing a dynamic heat transfer model. A large commercial greenhouse with an area of 26,640 m2 located in Izmir, Turkey was selected for considering Mediterranean climate, and a detailed heat transfer model of the greenhouse were developed considering heat transfers by convection, radiation, ventilation, and infiltration. A combination of air source heat pumps, photovoltaic panels and wind turbines were used for meeting the heating demand of the related greenhouse. Five different on-grid energy systems scenarios, namely (i) Photovoltaics-Heat Pump, (ii) Photovoltaics-Wind Turbine- Heat Pump, (iii) Wind Turbine- Photovoltaics- Heat Pump (iv) Wind Turbine- Heat Pump, and (v) only Heat Pump were considered. The system modelling with a detailed heat transfer analysis of the greenhouse was made by MATLAB. The energy analysis of the systems was performed on an hourly basis for one calendar year. The annual heating demand and the corresponding electricity consumption of the greenhouse were calculated as 497.37 and 114.07 kWh/m2, respectively. Net Present Value, Levelized Cost of Energy and CO2 savings were used to evaluate economic and environmental performances of the systems. Among five on-grid energy system scenarios, the first scenario, consisting of 5271 photovoltaic panels and 20 heat pumps, emerged as the most economically attractive choice with Net Present Value and Levelized Cost of Energy of $547,440.40 and 0.080146 $/kWh, respectively. Critical parameters affecting the economy of this scenario were found to be electricity prices, tomato yield, and photovoltaic panel prices. For environmental evaluation the fourth scenario, integrating wind turbines and heat pumps, achieves the highest CO2 savings of 2,064.73 tons due to increased renewable electricity production and lower life-cycle CO2 emissions of wind turbines compared to photovoltaic systems. This analysis enhanced the understanding of energy dynamics in greenhouse environments, contributing to the advancement of sustainable practices in agriculture. © 2024 Elsevier LtdArticle Citation - Scopus: 5Risk Analysis for Groundwater Intakes Based on the Example of Neonicotinoids(Elsevier Ltd, 2024) Pietrzak,D.; Kania,J.; Kmiecik,E.; Baba,A.Neonicotinoids are a class of broad-spectrum insecticides that are dominant in the world market. They are widely distributed in the environment. Understanding the sources, distribution, and fate of these contaminants is critical to mitigating their effects and maintaining the health of aquatic ecosystems. Contamination of surface and groundwater by neonicotinoids has become a widespread problem worldwide, requiring comprehensive action to accurately determine the mechanisms behind the migration of these pesticides, their properties, and their adverse effects on the environment. A new approach to risk analysis for groundwater intake contamination with emerging contaminants was proposed. It was conducted on the example of four neonicotinoids (acetamiprid, clothianidin, thiamethoxam, and imidacloprid) in relation to groundwater accessed by a hypothetical groundwater intake, based on data obtained in laboratory tests using a dynamic method (column experiments). The results of the risk analysis conducted have shown that in this case study the use of acetamiprid and thiamethoxam for agricultural purposes poses an acceptable risk, and does not pose a risk to the quality of groundwater extracted from the intake for food purposes. Consequently, it does not pose a risk to the health and life of humans and other organisms depending on that water. The opposite situation is observed for clothianidin and imidacloprid, which pose a higher risk of groundwater contamination. For higher maximum concentration of neonicotinoids used in the risk analysis, the concentration of clothianidin and imidacloprid in the groundwater intake significantly (from several to several hundred thousand times) exceeds the maximum permissible levels for drinking water (<0.1 μg/L). This risk exists even if the insecticides containing these pesticides are used according to the information sheet provided by the manufacturer (lower maximum concentration), which results in exceeding the maximum permissible levels for drinking water from several to several hundred times. © 2024 Elsevier LtdArticle Citation - WoS: 3Citation - Scopus: 4The Effect of Structural Retrofitting and Ventilation Scenarios on the Indoor Microclimate of a Historical Library: The Necip Pasa Library, Turkiye(Elsevier Ltd, 2024) Coskun,T.; Arsan,Z.D.; Akkurt,G.G.Structural retrofitting in buildings may result in changes in the indoor microclimate. Chemical, mechanical and biological deterioration can be seen in the cultural properties as a consequence of substrates and inappropriate microclimatic conditions such as high indoor temperature, relative humidity and fluctuations of them. The primary aim of the study is to evaluate the effect of the structural retrofitting, that the building underwent, on the chemical degradation risk of the library collection based on two different ventilation scenarios. One is natural ventilation which is an existing situation since the building is free-floating. The other one implementing a mechanical ventilation system into the building. To be able to compare the microclimate that affects the library collection pre- and post-retrofitting, two models are developed in DesginBuilder and simulated for both scenarios. According to the results of the post-retrofitting model, mechanical ventilation reduced the risk of chemical degradation by 38 %, while natural ventilation did not cause any effect. Natural ventilation gives a similar output in the pre-retrofitting model as in the post-retrofitting model. Mechanical ventilation in the pre-retrofitting model achieves a 33 % reduction in chemical degradation risk. Structural retrofitting only achieves a 1 % reduction in the chemical risk level for both ventilation scenarios. Thus, its effect on the indoor microclimate is insignificant. This study shows that creating simulation models effectively assesses potential risks pre-post-structural retrofitting or any retrofitting in historical buildings. Simulations reveal that mechanical ventilation is a better choice for decreasing chemical degradation risks for the library. © 2024 Elsevier LtdArticle Novel Neural Style Transfer Based Data Synthesis Method for Phase-Contrast Wound Healing Assay Images(Elsevier Ltd, 2024) Erdem,Y.S.; Iheme,L.O.; Uçar,M.; Özuysal,Ö.Y.; Balıkçı,M.; Morani,K.; Ünay,D.Recent advancements in the field of image synthesis have led to the development of Neural Style Transfer (NST) and Generative Adversarial Networks (GANs) which have proven to be powerful tools for data augmentation and realistic data generation. While GANs have been widely used for both data augmentation and generation, NST has not been employed for data generation tasks. Nonetheless, the simpler structure of NST compared to GANs makes it a promising alternative. In this research, we introduce an NST-based method for data generation, which to the best of our knowledge, is the first of its kind. By taking advantage of simplified architecture of NST models attributed to the utilization of a real image as the style input, our method enhances performance in data generation tasks under limited resource conditions. Additionally by utilizing patch-based training and high-resolution inference process high quality images are synthesized with limited resources. Furthermore multi-model and noised input is utilized for increased diversity with the novel NST-based data generation approach. Our proposed method utilizes binary segmentation maps as the condition input, representing the cell and wound regions. We evaluate the performance of our proposed NST-based method and compare it with a modified and fine-tuned conditional GAN (C-GAN) methods for the purpose of conditional generation of phase-contrast wound healing assay images. Through a series of quantitative and qualitative analyses, we demonstrate that our NST-based method outperforms the modified C-GAN while utilizing fewer resources. Additionally, we show that our NST-based method enhances segmentation performance when used as a data augmentation method. Our findings provide compelling evidence regarding the potential of NST for data generation tasks and its superiority over traditional GAN-based methods. The NST for data generation method was implemented in Python language and will be accessible at https://github.com/IDU-CVLab/NST_for_Gen under the MIT licence. © 2024 Elsevier Ltd
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