04. Mühendislik Fakültesi / Faculty of Engineering

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Citation - WoS: 10
Citation - Scopus: 11
Adapting Cities To Pluvial Flooding: the Case of Izmir (türkiye)
(MDPI, 2022-12) Salata, Stefano; Couch, Virginia Thompson; Velibeyoğlu, Koray; Baba, Alper; Saygın, Nicel; Uzelli, Taygun; 02.03. Department of City and Regional Planning; 03.03. Department of Civil Engineering; 02.02. Department of Architecture; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering; 02. Faculty of Architecture
In the coming decades, climate change will be one of the most significant challenges for urban areas. The quantity, duration and intensity of events, such as flash rains and heat waves, will increase the vulnerability of urban regions while exposing citizens to potentially dangerous conditions. According to the current literature, mainstreaming resilience in urban planning means designing rules that strengthen urban systems’ adaptive and self-regulating functions by reducing their vulnerability. In this work, we aimed to build knowledge for the application of the sponge district concept to Izmir (Türkiye), one of Europe’s most vulnerable areas to pluvial flooding. To do this, we first analyzed the runoff in each urban sub-watershed, then employed a composite index to determine potential areas of intervention for nature-based solutions. Results show that 10% of Izmir’s urban areas are extremely vulnerable to cloudbursts, which means that 40% of the urban population is exposed to this phenomenon. Moreover, the runoff calculation in the sub-watershed demonstrated that the potential flood volume is underestimated, especially in the upslope areas. The results can be used as a template to suggest a stepwise approach to mainstream the resilience of densely-inhabited coastal urban catchments.
Citation - WoS: 7
Citation - Scopus: 10
Adjuvant Potency of Astragaloside Vii Embedded Cholesterol Nanoparticles for H3n2 Influenza Vaccine
(TÜBİTAK, 2020) Genç, Rukan; Yakuboğulları, Nilgün; Nalbantsoy, Ayşe; Coven, Fethiye; Bedir, Erdal; 01.01. Units Affiliated to the Rectorate; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Adjuvants are substances that increase the immune response to a given antigen. In the development of novel vaccine adjuvants/systems, saponins are one of the most attractive molecules due to their altered immunomodulatory activities. In this study, we tried to develop PEG (polyethylene glycol)/cholesterol-based lipid nanoparticles (LNPs) to deliver the Astragaloside VII (AST-VII) and potentiate adjuvant properties of AST-VII for the influenza vaccine. In the formation of PEG/cholesterol/AST-VII-based LNPs (PEG300: Chol-AST-VII LNPs), 3 different primary solvents (acetone, ethanol, and chloroform) were evaluated, employing their effects on hydrodynamic particle size, distribution, surface chemistry, and colloidal stability. Prepared nanoparticles were simply admixtured with inactivated influenza antigen (H3N2) and applied to PMA (phorbol 12-myristate 13-acetate)-ionomycin treated human whole blood to evaluate their cytokine release profile. PEG300: Chol-AST-VII LNPs (80.2 +/- 7.7 nm) were obtained using chloroform as a desolvation agent. Co-treatment of PMA-ionomycin with AST-VII and PEG300: Chol-AST-VII LNPs significantly increased the levels of IL-2 and IFN-gamma, compared to PMA-ionomycin alone. In the presence of H3N2, AST-VII was able to augment IL-17A, while PEG300: Chol-AST-VII LNPs stimulated the production of IFN-gamma. Hemolysis was only observed in PEG300: Chol-AST-VII LNPs (250 mu g/mL) treatment. AST-VII and AST-VII-integrated LNPs could be used as efficacious adjuvants for an inactivated H3N2 vaccine in vitro, and cytokine response through Th1/Th17 route was reported.
Algıda gecikme ve kısa-ömürlü senkronizasyon temelli yeni bir hayali motor aktivite tanıma yaklaşımı
(IEEE, 2023) Olcay, B. Orkan; Karaçalı, Bilge; 01.01. Units Affiliated to the Rectorate; 03.05. Department of Electrical and Electronics Engineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
This study proposes a novel approach for investigating a brain-computer interface that considers the temporal organization of brain activity, explicitly accounting for perception latency. To this end, we aligned the onset of task periods with the concurrence of left parietal and parieto-occipital electrodes to obtain the timings of perception latencies. Then, activity-specific synchronization timings between channel pairs were calculated using the time-aligned task periods. The perception latency and activity-specific synchronization timings were subsequently used for feature extraction and classification. The proposed approach achieved significantly better performance when comparing the proposed approach with the method that did not account for the perception latency
Astragalus sp.
(CRC Press, 2023) Yakuboğulları, Nilgün; Bedir, Erdal; 01.01. Units Affiliated to the Rectorate; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Astragalus is one of the largest genera in Turkey and is widely distributed worldwide. The phytochemical studies on Turkish Astragalus species have presented 112 new compounds besides 63 known compounds. The overriding basis for biological activity studies is the traditional use of Astragalus roots in the Southeastern Region of Turkey to cure leukemia. As the isolated compounds did not show cytotoxic properties, a hypothesis that the biological activity of Astragalus saponins might result from the activation of the immune system came up. While Astragalus polysaccharides are used for their strong immunomodulatory activities in Chinese medicine, there are a few articles revealing the immunostimulatory properties of Astragalus saponins. Here, we summarized the compounds isolated from Turkish Astragalus species and concentrated on the immunomodulatory activities of these compounds to put forward their potential as saponin-based vaccine adjuvants. © 2024 selection and editorial matter, Ufuk Koca-Caliskan; individual chapters, the contributors.
Citation - WoS: 34
Citation - Scopus: 34
Biomimetic Hybrid Scaffold Consisting of Co-Electrospun Collagen and Pllcl for 3d Cell Culture
(Elsevier Ltd., 2019) Türker, Esra; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu; 04.01. Department of Chemistry; 03.01. Department of Bioengineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering; 04. Faculty of Science
Electrospun collagen is commonly used as a scaffold in tissue engineering applications since it mimics the content and morphology of native extracellular matrix (ECM) well. This report describes "toxic solvent free" fabrication of electrospun hybrid scaffold consisting of Collagen (Col) and Poly(L-lactide-co-epsilon-caprolactone) (PLLCL) for three-dimensional (3D) cell culture. Biomimetic hybrid scaffold was fabricated via co-spinning approach where simultaneous electrospinning of PLLCL and Collagen was mediated by polymer sacrificing agent Polyvinylpyrrolidone (PVP). Acidified aqueous solution of PVP was used to solubilize collagen without using toxic solvents for electrospinning, and then PVP was readily removed by rinsing in water. Mechanical characterizations, protein adsorption, as well as biodegradation analysis have been conducted to investigate feasibility of biomimetic hybrid scaffold for 3D cell culture applications. Electrospun biomimetic hybrid scaffold, which has 3D-network structure with 300-450 nm fiber diameters, was found to be maximizing cell adhesion through assisting NIH 3T3 mouse fibroblast cells. 3D cell culture studies confirmed that presence of collagen in biomimetic hybrid scaffold have created a major impact on cell proliferation compared to conventional 2D systems on long-term, also cell viability increased with the increasing amount of collagen. (c) 2019 Elsevier B.V. All rights reserved.
Citation - WoS: 26
Citation - Scopus: 28
Biotransformation of Cyclocanthogenol by the Endophytic Fungus Alternaria Eureka 1e1bl1
(Elsevier Ltd., 2018-07) Ekiz, Güner; Duman, Seda; Bedir, Erdal; 03.01. Department of Bioengineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
The microbial transformation of cyclocanthogenol (CCG), Astragalus sp. originated sapogenin, by the endophytic fungus Alternaria eureka 1E1BL1 isolated from Astragalus angustifolius was investigated. Hydroxylation, oxidation, epoxidation, O-methylation, ring-expansion and methyl migration reactions were observed on the triterpenoid skeleton. As a result, eight metabolites were isolated and the structures of the previously undescribed compounds were established by 1-D, 2-D NMR and HR-MS analyses.
Citation - WoS: 32
Citation - Scopus: 43
Boron in Geothermal Energy: Sources, Environmental Impacts, and Management in Geothermal Fluid
(Elsevier, 2022-10) 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, Aslı; 03.07. Department of Environmental Engineering; 03.02. Department of Chemical Engineering; 03.03. Department of Civil Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
The 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.
Citation - WoS: 24
Citation - Scopus: 30
Cold Sintering as a Promising Isru Technique: a Case Study of Mars Regolith Simulant
(Elsevier, 2023-01) Karacasulu, Levent; Karl, David; Gurlo, Aleksander; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Mars regolith simulant (MGS-1) was densified for the first time via a cold sintering process (CSP) as a novel in-situ resource utilization (ISRU) concept. The technique comprises the utilization of NaOH solution as a liquid media during the densification of simulant powder with <100 μm particle size. In as short as 30 min, with the increase in the NaOH concentration (from 3 M to 10 M) and processing temperature (from 150 °C to 250 °C), the relative densities of the regolith compacts and the mechanical properties were enhanced. The artifacts produced with Mars regolith simulant powder at 250 °C using 10 M NaOH solution yielded a relative density of around 88% and compressive strength reaching ∼45 MPa.
Citation - WoS: 8
Citation - Scopus: 9
Cold Sintering Assisted Two-Step Sintering of Potassium Sodium Niobate (knn) Ceramics
(Elsevier, 2023) Karacasulu, Levent; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Potassium sodium niobate (KNN) ceramics were densified using a multiple-stage sintering process in which initially applied cold sintering process (CSP) was followed by the solid-state sintering between 1100 and 1120 °C. Comparative assessments demonstrated that multi-step sintered samples yielded better properties than conventionally sintering ones. The highest relative density (94.7%) and the best electrical properties were obtained from the sample subjected to cold sintering at 120 °C/1 h using 5 wt% deionized water subsequently heat-treated at 1120 °C/2 h, resulting in a monolithic KNN ceramic having a piezoelectric coefficient of 120 pC/N. © 2023 Elsevier B.V.
Citation - WoS: 98
Citation - Scopus: 105
Cold Sintering of Ceramics and Glasses: a Review
(Elsevier Ltd., 2020) Ahmetoğlu, Çekdar Vakıf; Karacasulu, Levent; 03.09. Department of Materials Science and Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Traditionally ceramic artifacts are processed at high temperatures (> 1000 degrees C) by classical sintering techniques such as solid state, liquid phase and pressure-assisted sintering. Recently, inspired from the geology, novel sintering approaches that allow the densification of ceramic components at relatively low temperatures <= 400 degrees C have been proposed. While initial efforts for such low temperature densification concept were developed in the mid-70s, the topic has become increasingly prominent in the last decade. Currently, these low temperature methods can be classified into four main groups: (i) hydrothermal reaction sintering (HRS), (ii) hydrothermal hot pressing (HHP), (iii) pressure-assisted densification techniques: room-temperature densification (RTD), cold sintering (CS), warm press (WP), and finally no-pressure assisted method called (iv) reactive hydrothermal liquid phase densification (rHLPD). Above named techniques are commonly assisted by an aqueous solution used as either reactant or transient liquid phase to assist densification. Starting from the background in traditional sintering processes, this review aims to explore in depth the existing literature about low temperature densification approaches along with their advantages & disadvantages, and probable application areas.
Citation - WoS: 25
Citation - Scopus: 25
Conceptual Model of the Gülbahçe Geothermal System, Western Anatolia, Turkey: Based on Structural and Hydrogeochemical Data
(Elsevier Ltd., 2017-07) Uzelli, Taygun; Baba, Alper; Mungan, Gamze Gül; Dirik, Ramazan Kadir; Sözbilir, Hasan; 03.03. Department of Civil Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
The Gülbahçe Geothermal Field is located on the eastern margin of the Karaburun Peninsula, about 45 km from the city of İzmir, western Anatolia, Turkey. The stratigraphy of the study area is represented by a Miocene volcano-sedimentary succession, including several sedimentary and volcanic units. These units overlie the basement rocks of the Karaburun Platform and Bornova Flysch Zone which consist of sandstones, shales and carbonate blocks. These rock units are cut and deformed by a series of NW-SE- to NE-SW-trending faults, extending from Sığacık Bay to Gülbahçe Bay. Structural studies suggest that while most of the geothermal systems in western Anatolia are controlled by normal faults, the geothermal system at Gülbahçe is controlled by a strike-slip dominated shear zone, previously named the İzmir-Balıkesir Transfer Zone. Along the fault zone, associations of active fault segments accommodate deep circulation of hydrothermally modified sea water, and thus the resulting negative flower structure is the primary control mechanism for the geothermal system. Hydrogeochemical properties of the field show that surface temperature of fluid ranges from 30 to 34 °C. Geothermal fluids in Gülbahçe have high salinity (EC > 34 mS/cm) and low enthalpy. Piper and Schoeller diagrams indicate that geothermal fluid is in the NaCl facies. Chemical geothermometers suggest that the reservoir temperature is around 53–136 °C. The isotopic data (oxygen-18, deuterium and tritium) suggest that geothermal fluids are formed by local recharge and deep circulation of sea water.
Citation - WoS: 1
Citation - Scopus: 1
Correction: Scaffold-Free Three-Dimensional Cell Culturing Using Magnetic Levitation
(Royal Society of Chemistry, 2018) Türker, Esra; Demircak, Nida; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
The authors regret the inclusion of an incorrect figure caption for Fig. 2. The corrected figure caption for Fig. 2 is shown below. Fig. 2 Evaluation of levitation height (z) and density profiles through magnetic levitation. (A) Gd(III) chelates were named as Gx (Gadovist/Gadobutrol), Dx (Dotarem/Gadoteric acid) and Ox (Omniscan/Gadodiamide). (B) Standard curve for PE bead density against levitation height; linear curve fitting gives the standard function for the corresponding curve. (C–E) Levitation height profiles of single NIH 3T3 cells under 30/50/100/200 mM Gd concentrations. Single cell density profiles calculated through standard function of linear fitting.
Dalgacık gürültü giderme yöntemiyle mikrodalga bileşen karakterizasyonunun iyileştirilmesi
(IEEE, 2023) Karatay, Anıl; Olcay, Bilal Orkan; Yaman, Fatih; 01. Izmir Institute of Technology; 01.01. Units Affiliated to the Rectorate; 03.05. Department of Electrical and Electronics Engineering; 03. Faculty of Engineering
In this study, an efficient approach is presented to improve the characterization of various microwave components commonly used in communication and radar applications, such as antennas and power dividers. The components were initially simulated and then fabricated using the Computer Simulation Technology (CST) software. Vector Network Analyzer (VNA) measurements of the fabricated components were performed using a low-cost but noisy coaxial cable, and the measurement results were processed using a wavelet-based noise reduction method. For comparison purposes, the Haar and Daubechies-4 (DB4) wavelet functions were applied separately, and the results were examined. It was observed that the correlation and root mean square error between the ideal and measurement results improved in a positive direction with the noise reduction application. This approach provides significant cost and labor advantages, particularly when expensive elements such as gold and silver are used in coaxial cables that are physically free from noise. The experimental and numerical results show good agreement between the ideal simulation results and the filtered measurement results.
Citation - WoS: 1
Citation - Scopus: 1
Deneysel Mod Ayrıştırması Uygulanmış Yazma Hareket Bilgisi Kullanılarak El Yazısı Karakter Tanıma
(IEEE, 2017) Tuncer, Esra; Olcay, Bilal Orkan; Unlu, Mehmet Zubeyir; 03.05. Department of Electrical and Electronics Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
In this paper, handwritten character recognition by using characters' writing movements is investigated. To obtain the information about writing movements a 3-axis accelerometer is used. Just like most of other sensors, 3-axis accelerometers give the actual movement signal as well as noise. Before the recognition step, all of the signals need to be preprocessed and the noisy parts need to be removed. So, Empirical Mode Decomposition (EMD) and normalization preprocessing steps are applied to the signals. Finally, the signals in the dataset are compared with Dynamic Time Warping for classification and accurate classification rate of 91.92% is obtained.
Citation - WoS: 19
Citation - Scopus: 19
Development of Adjuvant Nanocarrier Systems for Seasonal Influenza a (h3n2) Vaccine Based on Astragaloside Vii and Gum Tragacanth (aps)
(Elsevier, 2019) Yakuboğulları, Nilgün; Genç, Rukan; Coven, Fethiye; Nalbantsoy, Ayşe; Bedir, Erdal; 01.01. Units Affiliated to the Rectorate; 03.01. Department of Bioengineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Adjuvants are chemical/biological substances that are used in vaccines to increase the immunogenicity of antigens. A few adjuvants have been developed for use in human vaccines because of their limitations including lack of efficacy, unacceptable local or systemic toxicity, the difficulty of manufacturing, poor stability, and high cost. For that reasons, novel adjuvants/adjuvant systems are under search. Astragaloside VII (AST-VII), isolated from Astragalus trojanus, exhibited significant cellular and humoral immune responses. The polysaccharides (APS) obtained from the roots of Astragalus species have been used in traditional Chinese medicine and possess strong immunomodulatory properties. In the present study, the immunomodulatory effects of a newly developed nanocarrier system (APNS: APS containing carrier) and its AST-VII containing formulation (ANS: AST-VII + APNS), on seasonal influenza A (H3N2) vaccine were investigated. Inactivated H3N2 alone or its combinations with test compounds/formulations were intramuscularly injected into Swiss albino mice. Four weeks after immunization, the immune responses were evaluated in terms of antibody and cytokine responses as well as splenocyte proliferation. APNS demonstrated Th2 mediated response by increasing IgG1 antibody titers, whereas ANS showed response towards Th1/Th2 balance and Th17 by producing of IFN-gamma, IL-17A and IgG2a. Based on these results, we propose that APNS and ANS are good candidates to be utilized in seasonal influenza A vaccines as adjuvants/carrier systems. (C) 2019 Elsevier Ltd. All rights reserved.
Citation - WoS: 19
Citation - Scopus: 22
Distance Estimation Methods for a Practical Macroscale Molecular Communication System
(Elsevier, 2020) Güleç, Fatih; Atakan, Barış; 01.01. Units Affiliated to the Rectorate; 03.05. Department of Electrical and Electronics Engineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Accurate estimation of the distance between the transmitter (TX) and the receiver (RX) in molecular communication (MC) systems can provide faster and more reliable communication. In addition, distance information can be used in determining the location of the molecular source in practical applications such as monitoring environmental pollution. Existing theoretical models in the literature are not suitable for distance estimation in a practical scenario. Furthermore, deriving an analytical model is a nontrivial problem, since the liquid in the TX is sprayed as droplets rather than molecules, these droplets move according to Newtonian mechanics, the size of the droplets change during their propagation and droplet-air interaction causes unsteady flows. Therefore, five different practical methods comprising three novel data analysis based methods and two supervised machine learning (ML) methods, Multivariate Linear Regression (MLR) and Neural Network Regression (NNR), are proposed for distance estimation at the RX side. In order to apply the ML methods, a macroscale practical MC system, which consists of an electric sprayer without a fan, alcohol molecules, an alcohol sensor and a microcontroller, is established, and the received signals are recorded. A feature extraction algorithm is proposed to utilize the measured signals as the inputs in ML methods. The numerical results show that the ML methods outperform the data analysis based methods in the root mean square error sense with the cost of complexity. The nearly equal performance of MLR and NNR shows that the input features such as peak time, peak concentration and the energy of the received signal have a highly linear relation with the distance. Moreover, the peak time based estimation, which is one of the proposed data analysis based methods, yields better results with respect to the other proposed four methods, as the distance increases. Given the experimental data and fluid dynamics theory, a possible trajectory of the molecules between the TX and RX is given. Our findings show that distance estimation performance is jointly affected by unsteady flows and the non-linearity of the sensor. According to our findings based on fluid dynamics, it is evaluated that fluid dynamics should be taken into account for more accurate parameter estimation in practical macroscale MC systems. (C) 2020 Elsevier B.V. All rights reserved.
Citation - WoS: 32
Citation - Scopus: 35
Distribution of Geothermal Arsenic in Relation To Geothermal Play Types: a Global Review and Case Study From the Anatolian Plate (turkey)
(Elsevier, 2021) Baba, Alper; Uzelli, Taygun; Sözbilir, Hasan; 03.03. Department of Civil Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Arsenic has a natural cycle as it travels underground. It can mix with geothermal fluid in different ways under the control of magmatic and tectonic processes. Geogenic arsenic is present in many geothermal fields in the world at concentrations above the limits set for human health. The arsenic content of geothermal fluids is also related to the concept of geothermal play type, which forms geothermal systems, because the natural processes that form the geothermal system also control the arsenic cycle. In this study, an attempt is made to explain the relationship between the geothermal play type concept and geothermal arsenic circulation. For this purpose, geothermal field examples are given from around the world and Turkey. The result shows that arsenic concentrations can reach significant levels along with plate tectonic boundaries in the world. When arsenic concentrations were evaluated, the effect of major faults on the Anatolian Plate was clearly seen. Also, in the Anatolian plate where volcanosedimentary units are common, geothermal fluids caused more effective alteration along with structural control and increased arsenic concentrations in geothermal systems. This interaction between structural elements, geothermal fluid, and the arsenic cycle shows that the concept of play type in geothermal systems should also be taken into consideration. It was determined that the places with high arsenic values are located within the convective-non-magmatic extensional geothermal play types such as Western Anatolian Extensional System and the North Anatolian Fault. The concept of play type in geothermal systems includes all systematic and external factors that make up these processes. For this reason, it is very important to evaluate the play type classification together with the arsenic cycle.
Citation - WoS: 13
Citation - Scopus: 15
A Droplet-Based Signal Reconstruction Approach To Channel Modeling in Molecular Communication
(Institute of Electrical and Electronics Engineers Inc., 2021) Güleç, Fatih; Atakan, Barış; 01.01. Units Affiliated to the Rectorate; 03.05. Department of Electrical and Electronics Engineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
In this paper, a novel droplet-based signal reconstruction (SR) approach to channel modeling, which considers liquid droplets as information carriers instead of molecules in the molecular communication (MC) channel, is proposed for practical sprayer-based macroscale MC systems. These practical MC systems are significant, since they can be used in order to investigate airborne pathogen transmission with biological sensors due to the similar mechanisms of sneezing/coughing and sprayer. Our proposed approach takes a two-phase flow which is generated by the interaction of droplets in liquid phase with air molecules in gas phase into account. Two-phase flow is combined with the SR of the receiver (RX) to propose a channel model. The SR part of the model quantifies how the accuracy of the sensed molecular signal in its reception volume depends on the sensitivity response of the RX and the adhesion/detachment process of droplets. The proposed channel model is validated by employing experimental data. IEEE
Citation - WoS: 1
Citation - Scopus: 1
Eeg Verisinde Kanallar-arası Zaman Uyumluluk Profilleri Kullanılarak Hayali Hareket Tanıma
(Institute of Electrical and Electronics Engineers Inc., 2016) Olcay, Bilal Orkan; Özgören, Murat; Karaçalı, Bilge; 01.01. Units Affiliated to the Rectorate; 03.05. Department of Electrical and Electronics Engineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Bu çalışmada, elektrotlar arası zaman gecikmesi kullanılarak bir beyin-bilgisayar ara yüzü çalışması gerçekleştirilmiştir. Öznitelik olarak, seçilen referans kanalı ile geriye kalan tüm kanalların çapraz kovaryansının mutlak değerinin en yüksek olduğu zaman gecikmeleri hesaplanmıştır. Çalışmada kullanılan 5 kişi içinden 3 kişinin sınıflandırma performansının %100’e yakın olmasının yanında bu kişilerin eğitim veri seti sayısının diğer iki kişiye göre oldukça düşük olması ve literatürde buna benzer çalışmaların azlığı, önerilen yaklaşımın geliştirilmeye açık olduğunu göstermektedir.
Citation - WoS: 4
Citation - Scopus: 13
Effects of Seismic Activity on Groundwater Level and Geothermal Systems in İzmir, Western Anatolia, Turkey: the Case Study From October 30, 2020 Samos Earthquake
(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2021) Uzelli, Taygun; Bilgiç, Esra; Öztürk, Bahadır; Baba, Alper; Sözbilir, Hasan; Tatar, Orhan; 01. Izmir Institute of Technology; 03.03. Department of Civil Engineering; 01.01. Units Affiliated to the Rectorate; 03. Faculty of Engineering
The October 30, 2020 Samos earthquake (Mw 6.6) affected the Aegean Sea and environs, caused destruction and loss of life in the city of İzmir located 70 km away from the earthquake epicenter. Before this earthquake, water resources were monitored in the areas of Bayraklı, Gülbahçe, and Seferihisar. For this purpose, 10 groundwater monitoring wells were drilled in the Bayraklı area, where groundwater level, temperature, and electrical conductivity changes were monitored at 1-h intervals in 5 wells. Besides physical parameters such as groundwater levels, temperatures and electrical conductivities, hydrogeochemical cations, and anions measured in the study area. Change in the groundwater levels was observed before, during, and after the Samos earthquake. A trend of rising groundwater level was observed two days before the mainshock, to a height of 10 cm, and the level was maintained till the end of the earthquake. The water levels returned to its original height after about 7 to 10 days of the earthquake. Moreover, electrical conductivity (EC) values were changed because of the interaction with the surrounding rocks and well walls, mixing with different waters during the earthquake shaking. The essential anomalies were observed in the geothermal fields of Gülbahçe and Seferihisar. Due to this earthquake, new geothermal springs emerged along the NE-SW trending Gülbahçe and Tuzla faults, located about 50 to 20 km from the Samos earthquake epicenter, respectively. The new geothermal waters are in Na-Cl composition and similar to other geothermal springs in the region. While the recorded water temperatures in the new geothermal springs vary from 40 to 45 °C in Seferihisar, it was measured between 35 and 40 °C in Gülbahçe. Due to these anomalies, it is found essential to monitor the effect of the earthquake on the physical and chemical characteristics of the groundwater and its usefulness in earthquake predictions.

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