Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
Browse
16 results
Search Results
Article Citation - WoS: 6Citation - Scopus: 9Holistic Managements of Textile Wastewater Through Circular, Greener and Eco-Innovative Treatment Systems Developed by Minimal To Zero Liquid Discharge(Elsevier, 2024) Aydıner, Coşkun; Doğan, Esra Can; Mert, Berna Kiril; Pala, Burcu; Demirozlu, Tugba Nur; Balcı, Esin; Narci, Ali OguzhanNew pragmatic and viable solutions to reduce or prevent discharge and to protect reserves are currently among the top-prioritised research for cleaner, circular, and resource-efficient use of industrial waters. So, the development of eco-sustainable water management is essential for green industrial development that will meet versatile and eco-sensitive regulatory standards, especially in water-intensive industries. Textile wastewater was reclaimed in semi to fully closed loops for minimal to zero liquid discharge. Concentrate-mixed wastewater was steadily treated in a hybrid membrane oxidation reactor at 60-80 % synergistic performances with remarkable UF fluxes of 96.4-820 L/m2h without any sludge discharge. Effluent was purified with 90-100 % removals and 20-80 L/m2h in nanofiltration and reverse osmosis. Due to Fenton-specific operation, more handling by ion exchange and neutralisation required to harvest membrane reuse waters and reactor discharge effluents with guaranteed Fe and pH. All-in-one system simulations indicated that high quality reuse waters are produced by 99.9 % efficiency and 98 and 100 % savings in iron and acid but 20-51 % more oxidant through concentrate recycling and regenerant reuse. It was also revealed that reactor effluents can be released to the sea or conventional biological treatment or can be eco-sustainably exploited for in-situ chemical and ex-situ bio-induced recovery of vivianite. This research demonstrates that how textile wastewater can be managed holistically by liquid discharge approaches from 50 % minimal to 99.9 % zero just in two-step, i.e. pretreatment and preconcentration, with consumable minimisation and valuable waste recovery through the eco-innovative systems which are developed as circular, greener, and sludge-free compatible with sustainable development goals.Letter Reply To the Discussion on “the Modified Vlasov Model on a Nonhomogeneous and Nonlinear Soil Layer”(Elsevier, 2023) İşbuğa, Volkan; Çerezci, Mehmet; Aşık, A. ZülfüThe discussion suggests that the paper has left out four references (Haldar and Basu, 2013; Haldar and Basu, 2016; Elhuni and Basu, 2019; Elhuni and Basu, 2021), and the research work in the paper is not new. The authors would like to state that the literature review in the paper was kept as vast as and to stay as close as possible to the model given in the paper, which is a gross model. The study aimed to offer a method using a previously developed formulation for accounting for soil nonlinearity (Vallabhan and Das, 1988,1991a,1991b). The primary concentration in the literature was given to the most relevant works on the modified Vlasov model that employs the same concept for the solution method and algorithm, which lays the foundation of the paper (Vallabhan and Das 1988,1991a,1991b; Asik, 1999; Asik and Vallabhan,2001). On the other hand, as clearly indicated in the study, the literature in the field is extensive, including the works suggested by the discussion. Despite the author’s efforts, it was not possible to review or/ and mention all the works previously conducted to solve the problem with different approaches. In this respect, the previous studies by Haldar and Basu (2013) and Elhuni and Basu (2019) mentioned in the discussion are not directly related to the problem considered in the paper. Haldar and Basu (2016) proposed a framework incorporating the finite difference and the finite element methods.Article Citation - WoS: 40Citation - Scopus: 47Boron in Geothermal Energy: Sources, Environmental Impacts, and Management in Geothermal Fluid(Elsevier, 2022) Mott, A.; Baba, Alper; Hadi Mosleh, Mojgan; Ökten, Hatice Eser; Babaei, Masoud; Gören, Ayşegül Yağmur; Feng, C.; Recepoğlu, Yaşar Kemal; Uzelli, Taygun; Uytun, Hüseyin; Morata, Diego; Yüksel Özşen, AslıThe problem of hazardous chemicals in geothermal fluid is a critical environmental concern in geothermal energy developments. Boron is among the hazardous contaminants reported to be present at high concentrations in geothermal fluids in various countries. Poor management and inadequate treatment of geothermal fluids can release excessive boron to the environment that has toxic effects on plants, humans, and animals. Despite the importance of boron management in geothermal fluid, limited and fragmented resources exist that provide a comprehensive understanding of its sources, transport and fate, and the treatment strategies in geothermal energy context. This paper presents the first critical review from a systematic and comprehensive review on different aspects of boron in geothermal fluid including its generation, sources, toxicity, ranges and the management approaches and treatment technologies. Our research highlights the origin of boron in geothermal water to be mainly from historical water-rock interactions and magmatic intrusion. Excessive concentrations of boron in geothermal fluids have been reported (over 500 mg/L in some case studies). Our review indicated that possible boron contamination in geothermal sites are mostly due to flawed construction of production/re-injection wells and uncontrolled discharge of geothermal water to surface water. The dominancy of non-ionic H3BO3 species makes the selection of the suitable treatment method for geothermal waters limited. Combining boron selective resins and membrane technologies, hybrid systems have provided effluents suitable for irrigation. However, their high energy consumption and course structure of boron selective resins encourage further research to develop cost-effective and environmentally friendly alternatives.Article Citation - WoS: 226Citation - Scopus: 255Altimetry for the Future: Building on 25 Years of Progress(Elsevier, 2021) Abdalla, Saleh; Kolahchi, Abdolnabi Abdeh; Ablain, Michael; Adusumilli, Susheel; Bhowmick, Suchandra Aich; International Altimetry Team; Öztunalı Özbahçeci, BergüzarIn 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the Green Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments' development and satellite missions' evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion. (c) 2021 COSPAR. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/Article Citation - WoS: 58Citation - Scopus: 76Utilization of Renewable Energy Sources in Desalination of Geothermal Water for Agriculture(Elsevier, 2021) Tomaszewska, Barbara; Gökçen Akkurt, Gülden; Kaczmarczyk, Michal; Bujakowski, Wieslaw; Keleş, Nazlı; Jarma, Yakubu A.; Baba, Alper; Bryjak, Marek; Kabay, NalanThe agricultural sector, which is highly dependent on water, is urged to build on improved water management practices and explore available options to match supply and demand because of the water scarcity risks and a sustainable and productive agri-food chain. Geothermal water is an energy source used to generate electricity and/or heat. After harnessing its energy, the remaining water can be used as a water source for irrigation following treatment because of its high ionic content. Geothermal fields are mostly located in rural areas where agricultural activities exist. This would be a good match to decrease the transportation cost of irrigation water. The energy demand of the desalination process for agriculture is higher, requiring additional post-treatment processes. Fossil fuels to fulfill the energy requirements are becoming expensive, and greenhouse gas emissions are harmful to the environment. Thus, efforts should be directed towards integrating renewable energy resources into desalination process. This work focuses on presenting a comprehensive review of geothermal water desalination which is powered by renewable energy and provides specific cases from Turkey and Poland. Furthermore, possible new generation renewable energy systems in desalination are introduced, considering their potential application in the desalination of geothermal water for agricultural irrigation.Article Citation - WoS: 7Citation - Scopus: 9Frequency Domain Data Merging in Operational Modal Analysis Based on Least Squares Approach(Elsevier, 2020) Hızal, ÇağlayanAssembling of multi-setup measurements emerges as a challenging problem in the structural health monitoring applications and may cause some important issues in the estimation of global modal parameters such as frequency, damping ratio and modal shape vector. To overcome this problem, a novel frequency domain pre-identification data merging method is proposed in this study. In the proposed methodology, to obtain a single measurement set, a least squares approach is employed resulting in a global response that is scaled from the multi-setup data. For the verification of the proposed merging procedure, one numerical, two experimental studies and one real data application have been conducted. The results obtained from the numerical, experimental and real data analysis indicate that the presented methodology provides rather high-quality estimations for multi-setup measurement problems. © 2020 Elsevier LtdArticle Citation - WoS: 6Citation - Scopus: 9Investigation of Car Park Preference by Intelligent System Guidance(Elsevier, 2020) Doğaroğlu, Bora; Çalışkanelli, S. PelinIn recent years, especially in developing countries, the number of vehicles has rapidly increased, leading to an increase in the demand for parking spaces. The most effective method to overcome this is to efficiently manage existing car parks. For this purpose, intelligent transportation system (ITS) applications have been used for facilities. In this study, the effect of guidance according to parking preferences on the utilisation of car parks with the support of an intelligent parking guidance system is examined. The preference and choice of car parks were modelled based on the observed data by developing a simulation program and testing the validity of the model. Subsequently, the effects of various parameters (e.g., parking fees, walking distance, and driving distance) on the selection of car parks, which have been ignored in the existing ITS, were included in the examination of the model. The results indicate that the driving distance and carbon dioxide emission, walking distance, and parking fees are reduced by 17, 14, and 1%, respectively. This study shows that system efficiency can be enhanced by considering additional car park preference parameters in intelligent parking system designs and management. © 2020 Elsevier LtdArticle Citation - WoS: 3Citation - Scopus: 3Structural Vulnerability of Ancient Dry Masonry Towers Under Lateral Loading(Elsevier, 2020) Gençer, Funda; Hamamcıoğlu Turan, Mine; Turan, Mine; Aktaş, Engin; Aktaş, EnginUnderstanding how the original characteristics contribute to the structural behaviour of antique structures should be the initial stage of planning for conservation work. This study aims to identify the structural behaviour of dry masonry towers under lateral loadings, so that the decision-making process when determining their restoration can be adequately supported. Dry masonry towers in ancient Caria, Pamphylia, and Cilicia Regions are examined. Each of these three areas have very different seismic characteristics. A hypothetical testing process was designed by combining different characteristics from each of the towers. As a result, the characteristics affecting the structural resistance were determined as; the staggering ratio, the stone depth, the ratio between block length and height, the proportional relationship between height and length, the area, number and position of openings, and the distribution of header stones. These characteristics all interact together to determine the failure mechanism; so, understanding this interaction is critical when considering conservation. © 2020 Elsevier LtdConference Object Citation - WoS: 2Citation - Scopus: 2A Case Study on the Selection of Optimum Loop Units for the Deployable Arch Structures Exposed To Lateral and Non-Uniform Gravity Loads(Elsevier, 2020) Yuceturk, K.; Aktas, E.; Maden, F.; Gur, S.; Mitropoulou, C. C.Radially deployable arches may be created by using various types of units. However, for any deployable structure to be constructed in real life, it should satisfy the structural regulations and codes. Despite various advantages from architectural perspective, deployable structures are weak to satisfy the operational code limits when compared to trusses with similar height and span. Therefore, weight minimization is very important to reduce the dead loads of the structure which facilitates the code-conformance of the structure. The optimization of the deployable structures requires an initial selection of the loop types to define the structure parametrically. An initial selection strategy depending on the loads on the structure is important to increase the efficiency of optimization process. Under uniform gravity loads, optimum arrangement for each unit type converges to a similar point. However, in the real world, the loads on the arches are not always uniform and the structure is exposed to nonuniform loadings such as point loads or lateral loads. This work focuses on the performance of various arches with different unit types under lateral and non-uniform vertical loads. Different lateral load and non-uniform gravity loading scenarios are created. For each scenario, the arches with different units are analyzed. In all cases, clear span and height are kept as same. The performance of an arch with a specific unit type for a given load is measured with a score that includes the deformations and the weight of the structure. All the members are assumed to be circular hollow sections with variable diameter and thickness to have a meaningful weight comparison between structures. This work intends to define an initial selection guide for deployable arches under typical non-uniform and lateral loading conditions. (C) 2020 The Authors. Published by Elsevier B.V.Article Citation - WoS: 22Citation - Scopus: 29Inter-Granular Cracking Through Strain Gradient Crystal Plasticity and Cohesive Zone Modeling Approaches(Elsevier, 2019) Yalçınkaya, Tuncay; Özdemir, İzzet; Fırat, Ali OsmanEven though intergranular fracture is generally regarded as a macroscopically brittle mechanism, there are various cases where the fracture occurs at the grain boundaries with considerable plastic deformation at the macroscopic scale. There exists several microstructural reasons for grain boundaries to host crack initiation. They can interact with impurities and defects, can provide preferential location for precipitation, can behave as a source of dislocations and can impede the movement of dislocations as well. The understanding of the crack initiation and propagation at the grain boundaries requires the analysis of the grain boundary orientation and the orientation mismatch between the neighboring grains and the related the stress concentration, which is only possible through the combination of micro-mechanical plasticity and fracture mechanics. For this reason the current work studies the evolution of plasticity in three dimensional Voronoi based microstructures through a strain gradient crystal plasticity framework (see e.g. Yalcinkaya et al., 2011; Yalcinkaya et al., 2012; Yalcinkaya, 2016) and incorporates a potential based cohesive zone model (see Park et al., 2009; Cerrone et al., 2014) at the grain boundaries for the crack initiation and propagation. The numerical examples considers the effect of the orientation distribution, the grain boundary conditions, the specimen size and the fracture energy parameter on the intergranular fracture behavior of micron-sized specimens. The study presents important conclusions for the modeling of fracture at this length scale.