Authors:Türker TUĞRUL; Mehmet Ali HINIS Abstract: Evaluation of precipitation and flow parameters and drought are essential in the management of a dam basin. Determining the changesin these parameters will contribute to the planning for the future of water resources. In this study, trend analysis of precipitation andflow data of the Apa Dam basin located in the boundaries of Konya Closed Basin and two drought indices namely StandardizedPrecipitation Index (SPI) and Streamflow Drought Index (SDI), obtained based on these data were performed. In the drought indices,indices for the corresponding to the precipitation totals of 3, 6, 9 and 12 months were used. In trend analysis, non-parametric Mann-Kendall (MK) test, Spearman’s Rho test and Innovative Trend Methods (ITA) were used to investigate whether there was a statisticalchange in the data and in which direction the change trend was.The results of trend analysis revealed that there is an increasing trend in all data in the findings obtained from ITA and increasingtrend in SPI6, SPI9 and SPI12 in α=0.01 significance level in the findings obtained from MK and increasing trend in SPI3 and SDI12 in α=0.10 α=0.05 significance level respectively, but the trend was not statistically significant in other data. In Spearman’s Rho test,on the other hand, an increasing trend was found in SPI6, SPI9 and SPI12 in α=0.01 significance level. However, the trend was notstatistically significant in other data. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Gökhan YAMAN; Selman TÜRKEŞ, Hakan GÜNEY, Ahmet Enver SIVACI, Bülent SARI, Olcayto KESKİNKAN Abstract: Poor air quality has harmful effects on human health and determination of pollutant levels in the air is important for human healthand the environment. The main purposes of this study are analyzing the winter air pollution of Gaziantep province in terms of someparameters (NO2 and SO2) and the discussing the necessary precautions to be taken. In this context, 5 passive samplings were made ateach of the 30 points determined between 2015-2020. Statistical analyzes of the measurement results were made using the SPSS 17.0V. program and it was determined that there were significant relationships between the results. FWhile sigmoid, logistic, gompertz, sınırlaandlinear models were developed with SigmaPlot Version 11.0 software, future predictions of pollutant values were made using linearartificial neural network (ANN) and non-linear artificial neural network (NARX-ANN) in MATLAB R2020a program. In the NO2and SO2 estimations made for 2040, the most reliable results were obtained with the linear model, and the pollutant concentrationswere calculated as 50.91 µg/m3 (R2 =0.9999) and 168.48 µg/m3 (R2=0.9762), respectively. Among the models developed with artificialneural networks, NARX-ANN Bayesian regulation algorithm was found to be more suitable and reliable for predictions (R2=0.8785for NO2, R2=0.9021 for SO2). Although it has a lower R2 than the linear model, the NARX-ANN model is considered to be moremeaningful because it also considers meteorological data in forecast calculations. At the end of the study, suggestions were presentedfor the improvement and sustainability of Gaziantep’s air quality. These are the homogeneous distribution of population density byurban transformation and city planning, the creation of infrastructures such as public transportation that will reduce traffic density, theincrease of incentives and grants for alternative clean fuels, and the establishment of a smart city concept integrating information andcommunication technologies and fixed/mobile measurement sensors. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Ümit Hüseyin KAYNAR; Sermin ÇAM KAYNAR Abstract: In this study, kula volcanite with alkaline basaltic structure and abundant abundance was used for strontium removal by increasing itsadsorption capacity with hexadecyltrimethylammonium (HDTMA) organic cation. First, the adsorbent was characterized by XRF,FT-IR and SEM. Then, the adsorption of Strontium (II) ions from aqueous solutions was measured with the ICP device and theexperiments were optimized by the surface response method (RSM). Central composite design (CCD) method was used for the studyplanning in the experiments. The theoretically adsorbed Strontium (II) at optimum values in the study was calculated as 31.978 mg/g.In addition, compatibility of various isotherms and thermodynamic parameters were evaluated in the study. According to the results, itwas concluded that this cheap and abundant adsorbent material can be effective in the separation and purification of radioactive wastes,and this structure can also be used in protective containers for the transport of wastes. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Özge KUYUCAK; Pınar TERZİOĞLU, Yusuf SICAK Abstract: Wound dressings play an important role in accelerating the healing of chronic non-healing wounds and preventing infection. Honey is evaluated in modern clinical wound care applications due to having biocompatible and bioactivity. In recent years, it is thought that honey / polymer hybrid materials can be ideal candidates with therapeutic properties that support the wound healing process. In this study, chitosan based films containing pine honey (0-12.5%) were developed by solution casting method. The morphology and structural properties of the films were determined by scanning electron microscopy and Fourier Transform Infrared Spectroscopy (FTIR), respectively. The antioxidant activity of the films was determined by four different methods. The FTIR spectra showed that pine honey was successfully incorporated into chitosan films. The addition of honey increased the antioxidant activity of the films. These results show that chitosan films containing pine honey are promising candidates for treating wounds. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Bahar BAŞTÜRK Abstract: In this study, laminated sandwich composites consist of glass fiber reinforced polymer (GFRP) face-sheets (skins) and polyvinyl chloride (PVC) foam were bonded together via conventional hand lay-up method. The effect of fiber orientation (0/90 or +45/-45) was examined in terms of compression and flexural properties. Flatwise (FW) compressive test provided the core dominated properties and only 0/90 fiber-oriented samples were tested. When the average edgewise (EW) compressive strength of (0/90)GFRP/PVC and (+45/-45)GFRP/PVC sandwich composites were compared, both of them showed similar results. Core crushing, local bending, debonding and core shear were observed as the common failure modes in the sandwich structures under bending. In terms flexural response, the 0/90 fiber oriented GFRP skin slightly showed better strength values as compared with +45/-45 fiber-oriented structures. By considering the all-quasi-static tests, it can be concluded that 0/90 and +45/-45 fiber oriented GFRP skins exhibited similar performance and there was no significant superiority for any of them. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Murat SÜRÜCÜ; Yalçın İŞLER, Resul KARA Abstract: Paroxysmal Atrial Fibrillation (PAF) is the initial stage of the Atrial Fibrillation that is one of the most common arrhythmia types. Although it does not threaten the life directly, it triggers the fatal disorders and it increases the risk of stroke. Therefore, it is essential to diagnose PAF as earlier as possible. For this purpose, there are many routine tests and pattern recognition based studies. In this study, we investigated the heart rate normalization method with its combination to feature normalization methods in the automatic diagnosis of PAF patients. First, Atrial Fibrillation Prediction Database, consisting of 30-minute ECG recordings and having open-access, was used to determine heart rate variability (HRV) data. Next, time-domain, frequency-domain, wavelet transform, and nonlinear features were extracted from both HRV and heart rate normalized HRV (HRN) data. These extracted features were normalized by MinMax and z-score methods. Hence, these six feature combinations of features directly and normalized versions from both HRV and HRN data were applied to the inputs of k-nearest neighbors (kNN) and multi-layer perceptron (MLP) classifier algorithms. Throughout the classifiers, features were selected using genetic algorithms. This study resulted in 81.00% accuracy with MinMax normalization using kNN algorithm and 91.92% accuracy with z-score normalization using MLP algorithm in HRV data. After applying the heart rate normalization, this study achieved 86.00% accuracy with z-score normalization using kNN algorithm and 95.96% accuracy with z-score normalization using MLP algorithm in HRN data. These results are higher than the other previous studies. The combination of heart rate normalization, Z-Score feature normalization, and multi-layer perceptron classifier outperforms the other studies related to automatic diagnosis of PAF in the literature. As a result of this study, we proved a new potential use of the heart rate normalization method in the diagnosis of PAF. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:F. Gülşen ERDİNÇ Abstract: This study proposes a novel energy management strategy for residential neighborhoods that enables peer-to-peer energy transactions among households without the need for energy storage or distributed generation. The proposed strategy is based on a Mixed-Integer Linear Programming (MILP) optimization model that minimizes the overall cost per household, including energy consumption cost, flexibility procurement cost, flexibility selling gain, and penalty cost caused by exceeding the limits. The strategy aims to optimize the energy consumption and production patterns of households with just inverter-based air conditioner loads, while also ensuring that the overall load limit for the neighborhood is not exceeded during certain periods. The results of the MILP-based optimization model demonstrate that the proposed strategy can significantly reduce the overall cost per household, providing a more efficient and cost-effective energy system for residential neighborhoods. The strategy utilizes a flexible energy trading platform, with a pricing mechanism designed to incentivize households to optimize their energy consumption and production patterns and support the transition to a low-carbon energy future. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Batuhan ÖZAKIN; Kürşat GÜLTEKİN, İlhan ÇELİK Abstract: Material selection plays a very important role in product design and development. In addition, the selection of the right material is of great importance for users to achieve high performance and sustainability. In product development, it is necessary to choose the optimum material that provides maximum performance and minimum cost. Recently, multi-criteria decision making methods have become the preferred methods to select the optimum Çizelge 1material. These methods analyze the problems by breaking them into small parts, then put the parts together and offer an effective solution to the problem. In this study, nanocomposites obtained by adding hexagonal boron carbide (B4C) nanoparticles in different weight ratios (0.5%, 1%, 2%, 3%, 4%, 5%) to the epoxy-based resin; Material selection was carried out by using MOORA and TOPSIS multi-criteria decision making methods by using tensile strength, strain, storage modulus, glass transition temperature (Tg), crosslink density, toughness and price properties. It was concluded that 2% by weight B4C added epoxy nanocomposite should be preferred as the optimum material in the material selections made by MOORA and TOPSIS multi-criteria decision making methods. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Nahit ÖZTOPRAK; Gökçe Mehmet GENÇER Abstract: Hot pressing is successfully proposed to bond metallic and polymeric materials as a direct-joining method to replace conventional assembly techniques. This article reports an experimental investigation on the failure mechanism analysis of single-lap joints (SLJs) subjected to tensile-shear loading. Al5754 alloy in H111 condition and long glass fiber reinforced-polypropylene (PP) composite are chosen as the adherends. In order to enhance the bond strength, laser processing is applied to the metal surface. A grid texture model by eight consecutive times scanning is utilized for the surface modification. After fabrication of the dissimilar joint, quasi-static mechanical performance of the metal-polymer hybrid structure is elucidated through tensile-shear testing. Thereafter, morphology of the fracture surfaces is evaluated by scanning electron microscopy (SEM). The experimental findings reveal that the laser surface texturing is proved to be an outstanding candidate for achieving strong joints through micro-interlocking in such metal/polymer multi-material connections. The ultimate force reaches the value of 1515.10 N after the 20 W laser surface pre-treatment. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Seyfullah KEYF; Pelin AKGÜL BAYRAKTAROĞLU Abstract: In this study, reactive elastomeric terpolymer (Elvaloy RET) and SEBS, waste carpet polymers were used for the modification of original TUPRAŞ 50/70 penetration bitumen. Softening point and penetration values are the essential and primary parameters for production of polymer modified bitumen. After the 50/70 penetration original bitumen was modified, softening point and viscosity values were determined to increase whereas the penetration value was determined to decrease. Polymer modified bitumen (CPMB) developed in the present study was compared with 8 different polymer modified bitumen defined according to the softening point and penetration values indicated in the Turkish Highways Polymer Modified Bitumen (TPMB) specification. It was determined that the penetration values at the 7 th hour of all 15 samles containing the incremental compositions of polymer modified bitumen (SEBS , waste carpet and Elvaloy RET) of the present study provided seven of the polymer modified bitumen values and all eight softening point values in the TPMB specification. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Ertan KÖSEDAĞ; Devrim İŞLER Abstract: In this study, the energy absorption capabilities of crash boxes, which provide energy absorption during an accident in the automotive transportation sector, were investigated. For this purpose, crash boxes in two different materials and four different geometries, Al6063 and A36 steel, were designed. The effects of triangle, square, circular, and hexagon cross-section geometries and material type on energy absorption were investigated using the finite element method, provided that the cross-sectional areas remained the same. In order to minimize the effect of mesh size on the analysis results made with the finite element method, a mesh free preliminary study was performed. Then, crash boxes made of all different geometric sections and different materials were subjected to crash tests under the same boundary conditions. As a result of the analysis, damage patterns, force-time curves, and energies absorbed by crash boxes were obtained. According to these results, the order from the most energy absorbing to the least energy absorbing geometry is hexagon, circle, square, and triangle. The same results were obtained for both material types. Steel material showed about ten times more reaction force than aluminum material. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Sermin ÇAM KAYNAR; İlayda TANER Abstract: Radiation has been present everywhere since the world existed. People are exposed to radiation in two ways, natural and artificial. Radiation enters the human body through eating and drinking, breathing or skin wounds. Among the health effects of radiation entering the human body, it is the most common cancer-causing effect. In this study, the measurement of natural radioactivity concentrations in some food products (wheat, red lentils, dried beans, corn, bananas, rice and green lentils) that we eat in our daily life and when the literature studies are considered to be higher than other food products. has been done. The obtained results were compared with the literature. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:İbrahim ALISKAN; Arif ŞAHİN Abstract: In this article, it is aimed to design and implement a system that can make precise position estimation on two-dimensional space (x,y) for indoor areas. There are many technologies used for solution in determining location indoor areas. Technologies such as RadioFrequency Identification (RFID), Ultra Wide Band (UWB), Wireless Fidelity (Wi-Fi), ZigBee and Bluetooth are among thesesolutions. Ultra Wide Band technology was compared with other technologies on the basis of criteria such as cost, coverage area,high accuracy in location estimation, and was used in this project due to its advantages explained in detail in the following sections.The created system basically consists of the target object (Tag), three fixed reference receiver modules (Anchor) and a main PC thatprocesses and simulates the obtained data. In the project, the Time Difference of Arrival (TDoA) method was chosen for distancemeasurements and applied in the study. Trilateration was applied as a mathematical positioning estimation method. The locationestimation of the target object was made continuously and Real Time Location System (RTLS) was performed and simulated onthe PC. Errors in position estimation were examined and Kalman filter was applied to increase accuracy. In addition, it has beendetermined that the accuracy in position estimation is increased when the fixed reference receivers are placed in the experimentalenvironment in a vertical position, equal height and forming an acute-angled triangle. The best results were obtained by applying filtersand placing the fixed reference receiver modules in optimum positions. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Ersagun Kürşat YAYLACI; Hatice Nur ÖZDEŞ, Ahmet Erdem YILMAZ Abstract: In this study, closed-loop output voltage control of the Buck converter is provided with Proportional-Integral controller, which iswidely used in the industry. In addition to mathematical methods in determining the controller coefficients, meta-heuristic methodshave been started to be preferred quite frequently in recent years. The Red Fox Optimization method is a new optimization algorithmrecently added to meta-heuristic methods. It was developed by being inspired by the lifestyles of the red foxes living in herds innature. In this study, the Red Fox Optimization algorithm was developed in order to require less user information in the system andto operate the system reliably without exceeding the design criteria. By using the developed Red Fox Optimization algorithm, steadystateerror and maximum overshoot, which are among the control performance criteria of the system, are tried to be improved withthe Proportional-Integral controller. The objective function is calculated by taking the average of the sum of the absolute values of theerror, the sum of the squares of the error, and the sum of the time-weighted squares of the error. This study is carried out in the Matlab/Simulink environment and the maximum overshoot criterion is specifical as in the range of 5-40%. The development process is alsoapplied to Grey Wolf Optimization (GWO), Firefly Optimization (FA) and Particle Swarm Optimization (PSO) methods and thefour optimization methods are compared. In the comparison process, it was observed that the improved GKO algorithm reached theresult in a shorter time in terms of the working time, and the controller performances were quite close to each other. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Volkan KUZUCU; Nazime DOGAN Abstract: Bacterial exopolysaccharides (EPSs) are biomolecules synthesized by many bacteria and have a variety of biological functions such asenvironmental protection, surface adhesion, and cellular interactions. Their strong biocompatible properties make them suitable fora variety of applications. As it is known, the disease burden of cancer is enormous both in terms of health and economy, thereforenumerous studies are being conducted to develop new chemotherapeutic agents and treatments for cancer by researchers. Literatureinformation indicates that EPSs can inhibit proliferation, angiogenesis and metastasis of cancer cells and stimulate apoptosis. Theeffects of EPS on breast, colon, lung and stomach cancer have been proven by scientific studies. This review briefly summarizesthe anticancer properties of bacterial EPSs and highlights their potential benefits as an agent that can reduce the side effects ofchemotherapy and radiotherapy. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Zehra Nil TAYLAN; İsmail Emrah KILIÇ, Mert TOLON Abstract: Within the scope of this study, which was based on the structural modelling variations of pile foundations, three different approachesfor different pile-soil interaction criteria were discussed. These approaches were respectively, i. simple model: fixed supported model,ii. detailed structural model: equivalent linear spring model and iii. detailed structural model: non-linear spring model. The firsttwo approaches were used for pre-dimensioning and were calculated for single raft thickness. In the third approach, the model wasiteratively analyzed for different slab thicknesses and the load distribution transferred to piles, slab stress distribution and settlementbehavior were examined. In this study a 26.0m x 50.0 m piled raft foundation of a 7 - story building was examined. In the structuralmodels created using the SAP 2000 program, the soil-structure behavior was expressed with relevant springs, and any soil resistancecontribution under the raft was not taken into account. Pile forces were obtained through definition of the actual load-deformationrelationships of the raft and the piles via varying raft thickness and non-linear soil links. The deformation characteristics and loaddistribution among the piles were evaluated for an optimal design. Finally, conservative versus comprehensive approaches for design ofa piled raft foundation under axial loading were discussed with respect to safety and feasibility where two approaches gave consistentresults. It is also concluded that the raft must be sufficiently rigid to distribute the loads to the piles effectively. In this specific study,the raft functions effectively once the thickness reached 1m and above. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Umut Emre UZUN; Nihat PAMUK, Sezai TASKIN Abstract: Different problems occur with the increasing energy demand in interconnected power systems operating under overload. The stability of the interconnected transmission system deteriorates with the growth of such possible problems or the simultaneous occurrence of several different problems. In order to correct these problems and increase the stability of the interconnected power system, Flexible Alternating Current Transmission System devices (FACTS) are connected to the power systems. FACTS devices, which consist of power electronics elements, instantly increase the loading capacity and stability of the power system with their fast and automatic response capabilities. In this study, a 420 kV Northwest Anatolian (KBA) Interconnected power system is investigated as an example power system. The most critical energy transmission lines are determined with the help of line stability indices in the examined high-voltage power system. FACTS devices, Thyristor Controlled Series Capacitor (TCSC), and Static Synchronous Series Capacitor (SSSC) are connected to the critical energy transmission lines in order to improve the voltage stability of the interconnected power system. At the end of the study, the effects of FACTS devices on bus voltage magnitudes, line loading parameter, active and reactive power losses in the power system are analyzed in detail. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Emre GÜNAY Abstract: In this study, the amount of float dust that can cause coal dust explosion in two underground coal mines (one hardcoal and one lignite). Besides, a proximate analysis has been performed for the samples obtained from underground and using the Hartmann apparatus it was determined whether the coal dust samples prepared were flammable. Smoldering temperatures of the coal dust samples were also found. The measurements performed underground revealed that the amount of float dust in lignite mine was between 14.36 mg/m3 and 72.23 mg/m3 and the amount of coal dust formed per ton of coal produced was between 9977 mg and 2717 mg. For underground hardcoal mine, the amount of float dust in was between 81.64 mg/m3 and 269.80 mg/m3 and the amount of coal dust formed per ton of coal produced was between 79024 mg and 278960 mg. The test performed by Hartmann Apparatus showed that both hardcoal and lignite dusts were flammable. In addition, depending on their ash content, smoldering temperatures of coal dusts were between 185°C and 240°C. The findings obtained from the study revealed that the number of studies on coal dust should be increased in our country. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Abdülkadir ÇILDIR; Mesud KAHRİMAN, Mesut TİGDEMİR Abstract: The main aim of dynamic intersection management is to make instant detection of vehicles both at the intersection and approaching it. In this sense, vehicle detection sensors have been preferred for dynamic intersection management. In this article, a LiDAR sensor system that can detect the number, velocity, and class of vehicles at intersections with different densities and also the length of vehicle queues that may occur at this intersection has been studied. In this study, 96.36 % success has obtained in the detection of the velocity, and 96.35 % success has also obtained in the queue detection. This study, which includes the data taken from a unidimensional LiDAR sensor and the capabilities of a 3D LiDAR sensor, stands out in terms of price and performance. PubDate: Fri, 30 Jun 2023 00:00:00 +030
Authors:Mehmet Kazım YETİK; Rahman ÇALHAN Abstract: This study is carried out in Turkey within the scope of Best Available Techniques (BAT) prepared in accordance with Article 16 (2)of Council Directive 96/61 / EC (IPPC Directive) Reference Document (BREF) for facilities operating in the “Surface Treatment ofMetals and Plastics (STM)” sector. It was conducted to ascertain the level of compliance with the Integrated Pollution Prevention andControl (IPPC) regulations of the facilities operating in Turkey, the transitional periods to IPPC, and their distribution by provinces.For the study, a survey of the facilities covered by the directive was conducted, and the responses from the institutions were statisticallyanalyzed. According to the results of the analysis, the distribution of the facilities within the scope by provinces in Turkey, which BATshould be prioritized for IPPC compliance, and the time required for the necessary improvements/investments were determined PubDate: Fri, 30 Jun 2023 00:00:00 +030
Open Access journal
