IZTECH Research Centers Collection / İYTE Araştırma Merkezleri Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11147/2636
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Article Citation - WoS: 6Citation - Scopus: 6A Novel Land Surface Temperature Reconstruction Method and Its Application for Downscaling Surface Soil Moisture With Machine Learning(Elsevier, 2024) Güngör, Şahin; Gündüz, OrhanDownscaling of soil moisture data is important for high resolution hydrological modeling. Most downscaling studies in the literature have used spatially discontinuous land surface temperature (LST) maps as the main auxiliary parameter, which limits the creation of continuous soil moisture maps. The number of studies on soil moisture downscaling with machine learning that use gapless LST maps is limited. With this motivation, a hybrid reconstruction method has been proposed in this study to practically obtain continuous LST maps, which are then used to produce high resolution surface soil moisture (SSM) datasets. The proposed method is shown to have high mean performance with R2 and RMSE values of 0.94 and 1.84°K, respectively, for the period between 2019 and 2022. The developed reconstructed LST maps were then used to downscale original 9 km spatial resolution soil moisture datasets of SMAP L3 and SMAP L4 with Random Forest (RF) machine learning algorithm. The RF model were run with four different rainfall datasets, and the MSWEP rainfall dataset was found to produce the best results. The use of antecedent rainfall values as input variables in machine learning models has been shown to improve the performance of the models R2 0.76 to 0.93. The accuracy of the downscaled data was later evaluated for Western Anatolia Basins (WAB) in Türkiye with 31 in-situ stations. The downscaled SMAP L4 had good average statistical indicators R (0.815 ± 0.1), RMSE (0.09 ± 0.047 cm3/cm3), and ubRMSE (0.058 ± 0.025 cm3/cm3). Downscaled SMAP L3 was also validated with in-situ observations with satisfactory R (0.79 ± 0.074), RMSE (0.09 ± 0.043 cm3/cm3), and ubRMSE (0.06 ± 0.026 cm3/cm3) statistics. Furthermore, the performance of the downscaled SMAP L3 was also cross validated with SMAP + Sentinel 1 (L2) dataset between 2019 and 2022. The mean statistics of R (0.761 ± 0.11) and Root Mean Squared Difference (RMSD) (0.05 ± 0.014 cm3/cm3) between downscaled SMAP L3 and L2 data revealed that the new reconstruction method of LST used in the RF model for downscaling of soil moisture performed well to obtain high resolution soil moisture datasets. The proposed technique also overcame the difficulties associated with coastal regions where data was masked for quality considerations, by not only enhancing overall spatial resolution but also filling these data gaps and giving a complete SSM coverage. © 2024 Elsevier B.V.Article Citation - WoS: 36Citation - Scopus: 40Statistical Downscaling of Grace Twsa Estimates To a 1-Km Spatial Resolution for a Local-Scale Surveillance of Flooding Potential(Elsevier, 2023) Khorrami, Behnam; Pirasteh, Saied; Ali, Shoaib; Şahin, Onur Güngör; Vaheddoost, BabakThe Gravity Recovery and Climate Experiment (GRACE) paved the way for large-scale monitoring of the hydrological extremes. However, local scale analysis is aslo challenging due to the coarse resolution of the GRACE estimates. The feasibility of the downscaled GRACE data for the flood monitoring in the Kizilirmak Basin (KB) in Turkiye is investigated in this study by integrating the GRACE and hydrological model outputs of a random forest approach. Results suggest that the TWSA, over the Asagi Kizilirmak Basin (AKB), is ascending with an annual rate of + 3.51mm/yr; while the Orta Kizilirmak Basin (OKB), Yukari Kizilirmak Basin (YKB), Delice Basin (DB), Develi Kapali Basin (DKB), and Seyfe Kapali Basin (SKB) showed descending trend respectively as -1.15mm/yr, -1.58mm/yr, -1.14mm/yr, -2.34mm/yr, and -1.31mm/yr. The hydrological status of the basin showed that in 2003, 2005, 2010-2013, and 2015-2016 periods the study area was prone to the inundation. Hence, by validating the Flood Potential Index (FPI) rates acquired from the downscaled GRACE data, it was shown that the best correlation coefficient (0.73) between FPI and streamflow (Q) is associated with the SKB. It is also concluded that the downscaled TWSA associated with the fine-resolution models depicts acceptable accuracy in determination of the flood potential at local scales.Article Perfluoropentacene Thin Films on Au(1 1 1) Surfaces: Effect of Kinetic Energy and Vibrational Properties(Elsevier, 2022) Yavuz, Adem; Danışman, M. FatihWe studied vibrational properties and the effect of beam kinetic energy on perfluoropentacene (PFP) thin films grown by supersonic molecular beam deposition (SMBD) technique on gold surfaces. Though similar growth mechanism was observed for different beam kinetic energies, in the case of low coverage (less than 1 monolayer) films and for low deposition rates significant differences were observed in the properties of films grown by using helium and argon carrier gasses with the former case resulting in higher average grain size. For multilayer films however there were no significant differences between helium and argon grown films. Vibrational properties were investigated by using Infrared Scattering-type Scanning Nearfield Optical Microscopy (s-SNOM) on clean and m-carborane-1-thiol (M1) coated template-stripped gold (TSAu) substrates. For both substrates thick PFP films (15 nm) had similar spectra whereas there were significant differences in the spectra of thin films (1 nm) due to PFP-substrate interactions. Davydov splitting of the IR modes were observed for both 1 nm and 15 nm films indicating similar molecular arrangements in both type of films.Article Citation - WoS: 43Citation - Scopus: 61Current Status and Perspectives of Protease Inhibitors and Their Combination With Nanosized Drug Delivery Systems for Targeted Cancer Therapy(Dove Medical Press Ltd, 2021) Rudzinska, Magdalena; Dağlıoğlu, Cenk; Savvateeva, Lyudmila, V; Kaci, Fatma Necmiye; Antoine, Rodolphe; Zamyatnin, Andrey A., Jr.In cancer treatments, many natural and synthetic products have been examined; among them, protease inhibitors are promising candidates for anti-cancer agents. Since dysregulated proteolytic activities can contribute to tumor development and metastasis, antagonization of proteases with tailored inhibitors is an encouraging approach. Although adverse effects of early designs of these inhibitors disappeared after the introduction of next-generation agents, most of the proposed inhibitors did not pass the early stages of clinical trials due to their nonspecific toxicity and lack of pharmacological effects. Therefore, new applications that modulate proteases more specifically and serve their programmed way of administration are highly appreciated. In this context, nanosized drug delivery systems have attracted much attention because preliminary studies have demonstrated that the therapeutic capacity of inhibitors has been improved significantly with encapsulated formulation as compared to their free forms. Here, we address this issue and discuss the current application and future clinical prospects of this potential combination towards targeted protease-based cancer therapy.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: 8Citation - Scopus: 14An End-To Trainable Feature Selection-Forecasting Architecture Targeted at the Internet of Things(IEEE, 2021) Nakıp, Mert; Karakayalı, Kubilay; Güzeliş, Cüneyt; Rodoplu, VolkanWe develop a novel end-to-end trainable feature selection-forecasting (FSF) architecture for predictive networks targeted at the Internet of Things (IoT). In contrast with the existing filter-based, wrapper-based and embedded feature selection methods, our architecture enables the automatic selection of features dynamically based on feature importance score calculation and gamma-gated feature selection units that are trained jointly and end-to-end with the forecaster. We compare the performance of our FSF architecture on the problem of forecasting IoT device traffic against the following existing (feature selection, forecasting) technique pairs: Autocorrelation Function (ACF), Analysis of Variance (ANOVA), Recurrent Feature Elimination (RFE) and Ridge Regression methods for feature selection, and Linear Regression, Multi-Layer Perceptron (MLP), Long Short Term Memory (LSTM), 1 Dimensional Convolutional Neural Network (1D CNN), Autoregressive Integrated Moving Average (ARIMA), and Logistic Regression for forecasting. We show that our FSF architecture achieves either the best or close to the best performance among all of the competing techniques by virtue of its dynamic, automatic feature selection capability. In addition, we demonstrate that both the training time and the execution time of FSF are reasonable for IoT applications. This work represents a milestone for the development of predictive networks for IoT in smart cities of the near future.Article Citation - WoS: 32Citation - Scopus: 35Distribution 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, HasanArsenic 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.Article Citation - WoS: 34Citation - Scopus: 41Assessment of Geothermal Energy Use With Thermoelectric Generator for Hydrogen Production(Pergamon-Elsevier Science LTD, 2021) Hadjiat, M. M.; Hancıoğlu, Ebru; Mraoui, A.; Ouali, S.; Hancıoğlu Kuzgunkaya, Ebru; Salhi, K.; Ouali, A. Ait; Benaouda, N.In this work, a new model for producing hydrogen from a low enthalpy geothermal source was presented. Thermal energy from geothermal sources can be converted into electric power by using thermoelectric modules instead of Organic Rankine Cycle (ORC) machines, especially for low geothermal temperatures. This electrical energy uses the water electrolysis process to produce hydrogen. Simulation and experiments for the thermoelectric module in this system were undertaken to assess the efficiency of these models. TRNSYS software is used to simulate the system in Hammam Righa spa, the temperature of this spring is 70 degrees C. Obtained results reveal that in hammam righa spa in Algeria, 0.5652 Kg hydrogen per square meter of thermoelectric generator (TEG) can be produced in one year. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 58Citation - Scopus: 59Assessment of Different Nanofiltration and Reverse Osmosis Membranes for Simultaneous Removal of Arsenic and Boron From Spent Geothermal Water(Elsevier, 2021) Jarma, Yakubu A.; Karaoğlu, Aslı; Tekin, Özge; Baba, Alper; Ökten, H.Eser; Tomaszewska, Barbara; Kabay, NalanOne of the factors that determine agricultural crops’ yield is the quality of water used during irrigation. In this study, we assessed the usability of spent geothermal water for agricultural irrigation after membrane treatment. Preliminary membrane tests were conducted on a laboratory-scale set up followed by mini-pilot scale tests in a geothermal heating center. In part I, three commercially available membranes (XLE BWRO, NF90, and Osmonics CK- NF) were tested using a cross-flow flat-sheet membrane testing unit (Sepa CF II, GE-Osmonics) under constant applied pressure of 20 bar. In part II, different spiral wound membranes (TR-NE90-NF, TR-BE-BW, and BW30) other than the ones used in laboratory tests were employed for the mini-pilot scale studies in a continuous mode. Water recovery and applied pressure were maintained constant at 60% and 12 bar, respectively. Performances of the membranes were assessed in terms of the permeate flux, boron and arsenic removals. In laboratory tests, the permeate fluxes were measured as 94.3, 87.9, and 64.3 L m?2 h?1 for XLE BWRO, CK-NF and NF90 membranes, respectively. The arsenic removals were found as 99.0%, 87.5% and 83.6% while the boron removals were 56.8%, 54.2%, and 26.1% for XLE BWRO, NF90 and CK-NF membranes, respectively. In field tests, permeate fluxes were 49.9, 26.8 and 24.0 L m?2 h?1 for TR-NE90-NF, BW30-RO and TR-BE-BW membranes, respectively. Boron removals were calculated as 49.9%, 44.1% and 40.7% for TR-BE-BW, TR-NE90-NF and BW30-RO membranes, respectively. Removal efficiencies of arsenic in mini-pilot scale membrane tests were all over 90%. Quality of the permeate water produced was suitable for irrigation in terms of the electrical conductivity (EC) and the total dissolved solids (TDS) for all tested membranes with respect to guidelines set by the Turkish Ministry of Environment and Urbanisation (TMEU). However, XLE BWRO, CK-NF and NF90 membranes failed to meet the required limits for irrigation in terms of boron and arsenic concentrations in the product water. The permeate streams of TR-BE-BW, TR-NE90-NF and BW30-RO membranes complied with the irrigation water standards in terms of EC, TDS and arsenic concentration while boron concentration remained above the allowable limit. © 2020 Elsevier B.V.Article Citation - WoS: 3Citation - Scopus: 3Energy Performance Assessment in Terms of Primary Energy and Exergy Analyses of the Nursing Home and Rehabilitation Center(SAGE Publications Inc., 2019) Hancıoğlu Kuzgunkaya, EbruThis paper concerns with the energy analysis (based on primary energy) and exergy analysis of Narlıdere Nursing Home and Rehabilitation Center (NNHRC) in İzmir, Turkey that was chosen as a sample public building. The Center services as a nursing and rehabilitation center for the aged and it also includes a geriatric division operating as a hospital. The Center was analyzed using the actual energy consumption data derived from several energy audits. Energy efficiency (according to the primary energy ratio) and exergy efficiency of the facility were calculated to be 59% and 14%, respectively. The results have indicated that the exergy efficiencies of space heating and cooling have the lowest values compared with the other units of facility. Specific primary energy consumption and specific exergy consumption of the facility were found to be 271.91 kWh/m2 year and 290.23 kWh/m2 year, respectively. Sustainability index value of the overall NNHRC was found to be 1.621.