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Koleksiyondaki öğeler
- MakaleYayıncıda açık erişim2023Scopus SJRQ3Chemical Content and Antimicrobial Activities of Essential Oils Obtained from Plant Parts of Juniperus excelsa M. Bieb.; [Kemijski sastav i antimikrobno djelovanje eteričnih ulja dobivenih iz dijelova biljke Juniperus excelsa M. Bieb.]
Saruhan, Emrah; Öz, Mehmet
This study was conducted to determine the chemical content, antibacterial, and antifungal properties of essential oil obtained from the parts of the plant called Juniperus excelsa M. Bieb. In this study, essential oils of cone, needle, and twig of J. excelsa plant, which is a naturally grown plant in Gümüşhane province, were obtained by hydrodistillation method in a Clevenger type device. Chemical composition of essential oils was determined thanks to the analysis conducted with GC-MS/FID device. Besides, antimicrobial activity tests of essential oils were decided in contrast to 23 different microorganisms with the disc diffusion method. As a result of the essential oil analysis of J. excelsa, the percentage of essential oil yield in cones, needles, and twigs was found as 5.88 %, 2.00 %, and 0.62 %, respectively. α-pinene was confirmed to be the most abundant main compound found in the essential oils of cones, needles, and twigs. As a result of the essential oil analysis of the cone, needle, and twig of J. excelsa species, it was revealed that monoterpenes were the most abundant chemical class in terms of percentage. In the antimicrobial activity test performed on the essential oils of J. excelsa plant parts, it was found that cones, needles, and twigs have a strong antimicrobial effect against Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus, Candida albicans, Penicillum expansum, Saccharomyces cerevisiae bacteria, yeast, and molds.
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İncele - MakaleAçık Erişim2022Scopus SJRQ2Antioxidant capacity and rheological, textural properties of ice cream produced from camel's milk with blueberry
Sayar, Esra; Şengül, Mustafa; Ürkek, Bayram
Blueberry was added to ice cream samples produced from camel's milk at different concentrations. The physicochemical, rheological, and sensory properties, total phenolic content (TPC), and antioxidant capacity of samples were investigated. The acidity and hardness values of the samples increased, but total solids, fat, protein, pH, ash, overrun values, and complete meltdown time significantly decreased with increasing concentration of blueberry. The L* and b* values decreased, while a* and H° values increased due to the presence of natural colorants in blueberry. The viscosity and consistency coefficient values of ice cream samples decreased depending on the blueberry concentration, whereas TPC and antioxidant capacity increased. The addition of blueberry did not have any affirmative or negative effect on the sensory properties of samples except for appearance, color, and flavor scores. Consequently, blueberry could be added to the ice cream produced using camel's milk at less than a ratio of 10% to improve its nutritional properties. Novelty impact statement: Ice cream made from camel's milk with blueberry is a novel dairy product. It is a functional product due to its high antioxidant activity and total phenolic component. The addition of blueberry does not have a negative effect on the sensory properties of the ice cream. As a result, blueberry and camel's milk could be used in new ice cream formulations to produce a nutritional and functional product.
AtıfScopus17WoS16OpenAlex16İncele - MakaleAçık Erişim2024Scopus SJRQ3The Effect of Smartphone Addiction on Sleep Quality and Lifestyle Behaviors of Adolescents
Göger, Berrin; Kahriman, Ilknur
Many studies highlight the negative impact of smartphone addiction on adolescents’ health. It disrupts sleep habits and lifestyle. The study was conducted to evaluate the effect of smartphone addiction on the sleep quality and lifestyle behavior of adolescents. It was conducted in public high schools in a city center in the Eastern Black Sea Region of Türkiye. The sample consisted of 546 high school students. Data were collected using a Descriptive Information Form for Adolescents, the Smartphone Addiction Scale—Short Version, the Pittsburgh Sleep Quality Index, and the Adolescent Lifestyle Profile Scale. According to the results, the incidence of smartphone addiction among adolescents differed according to gender, academic achievement, age of first smartphone (p =.044), and daily smartphone use time (p =.000). Mean Pittsburgh Sleep Quality Index scores were not significantly different for the same variables. There was a significant difference in mean Adolescent Lifestyle Profile Scale scores according to academic achievement, having a smartphone, and age of first smartphone acquisition. There was a weak positive correlation between smartphone addiction and Pittsburgh Sleep Quality Index scores and a weak negative correlation between smartphone addiction and Adolescent Lifestyle Scale scores. There was also a weak negative correlation between Pittsburgh Sleep Quality Index scores and Adolescent Lifestyle Scale scores. Smartphone addiction negatively affects adolescents’ sleep quality and lifestyle.
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İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of moral sensitivity and moral courage in intensive care nurses in Turkey during the COVID-19 pandemic
Goktas, Sonay; Aktug, Cemile; Gezginci, Elif
Background: During the COVID-19 pandemic, intensive care nurses may experience ethical issues related to fear of transmission, limited resources, and increased workload. Nurses' moral sensitivity and courage may have a role in dealing with these problems. Aim: The purpose of this study was to assess intensive care nurses' moral sensitivity and moral courage during the COVID-19 pandemic. Design: Descriptive cross-sectional survey. Methods: A total of 362 nurses working in the intensive care units of pandemic hospitals in Turkey participated in the study between January and March 2021. Data were obtained using a personal information form, the Moral Sensitivity Questionnaire, and the Nurses' Moral Courage Scale. A link to the online data collection tools was sent to the management of participating institutions, who forwarded it to nurses. Reporting followed the CHERRIES guidelines. Results: In this study, the response rate of nurses was 89%. The nurses' total mean moral sensitivity score was 90.70 ± 28.89 and their mean moral courage score was 82.08 ± 13.51. A weak inverse correlation was found between the nurses' moral sensitivity and moral courage scores (r = −.176, p =.001). Total moral sensitivity score differed significantly according to years of Intensive care unit (ICU) experience (p =.007). Total moral courage scores increased significantly with education level (p =.012), years of nursing experience (p =.016), and willingness to work in the ICU (p <.001). Conclusion: The study suggests that nurses working in the intensive care unit during the pandemic had moderate moral sensitivity and high levels of moral courage. Nurses' sociodemographic characteristics and ICU work conditions may affect their moral sensitivity and moral courage. Relevance to Clinical Practice: The results of this study can help guide efforts to improve moral courage and sensitivity and address ethical issues among ICU nurses.
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İncele - MakaleYalnız künye2023Scopus SJRQ2Trend analysis of precipitation using innovative approaches in northwestern Turkey
Körük, Ali Emre; Kankal, Murat; Yıldız, Mehmet Berkant; Akçay, Fatma; Şan, Murat; Nacar, Sinan
Precipitation is highly sensitive to climate change, and monitoring its trends over time is essential for understanding the effects of global warming on the Earth's water cycle. This study investigates the effects of climate change on monthly precipitation in the Susurluk Basin located in northwestern Turkey, using innovative trend analysis methods. Innovative Polygon Trend Analysis (IPTA) using star graphics and Improved Visualization for Innovative Trend Analysis (IV-ITA) techniques were used to analyze precipitation data from nine stations in the basin over 50 years (1970–2019), and the findings were compared to classical Mann-Kendall (MK) results. According to the trend analysis results, the MK method detected significant trends in only two months in the decreasing direction. In these decreasing trends observed at Simav and Keles stations in November, z values were calculated as −2.38 and −2.05, respectively. IPTA method detected increasing trends in 54 months and decreasing trends in 40 months; this means there is a change of more than 5% between two half series. The IV-ITA method indicated an increase of more than 40% in the low values for January, March, August, and September. In addition, there was an increasing trend of more than 40% in the high values observed in September at all stations. It was observed that mean precipitation heights increased from September to December and then decreased throughout the basin. It is predicted that decreases in precipitation during dry seasons may put intense pressure on agricultural water use and affect water quality. In addition, the increase in precipitation in spring months may increase flood events. It was determined that graphical innovative trend analysis methods are more effective in trend identification than MK, and these methods' results have much higher visual inspection and linguistic interpretation possibilities. Innovative methods allow for more flexible and in-depth analysis using different statistical parameters.
AtıfScopus40WoS34OpenAlex43İncele - MakaleAçık Erişim2023Scopus SJRQ1A comparative study of evolutionary computation and swarm-based methods applied to color quantization
Pérez-Delgado, María-Luisa; Günen, Mehmet Akif
Color Quantization (CQ) is a complex and hard problem because selecting the best set of colors from many available colors and using that set to obtain a good quality image is an NP-complete problem. The use of evolutionary computation and swarm-based methods to solve search and optimization problems has increased dramatically in recent years. This article compares some of these methods in order to solve the CQ problem. The following methods were used to generate CQ images: Particle swarm optimization, Artificial bee colony, Adaptive differential evolution, Success-history based adaptive differential evolution (with and without linear population size reduction), Cuckoo search, Firefly algorithm and Shuffled-frog leaping algorithm. For the first two methods, two variants were considered. Thus, a total of ten metaheuristics were compared with four classical CQ methods (Variance-based, Median-cut, Binary splitting and Wu's methods) applying them to a set of benchmark images and considering four different palette sizes (32, 64, 128, and 256 colors). Three error measures were considered to compare the methods: the mean squared error, the mean absolute error and the peak signal-to-noise ratio. Some of the swarm-based methods analyzed include a recently proposed CQ method using ants. Although they have a slow computational speed in the experimental studies, the ant-based methods are significantly better than all other methods according to the Wilcoxon signed rank test. In general, despite their speed, classical methods underperform the other ten methods both qualitatively and quantitatively.
AtıfScopus8WoS6OpenAlex7İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ1DEVELOPMENT OF THE THIRST DISCOMFORT SCALE: A VALIDITY AND RELIABILITY STUDY
Çiftçi, Bahar; Yıldız, Güzel Nur; Avşar, Gülçin; Köse, Sema; Aydın, Esra; Doǧan, Sevgi; Çelik, Şeymanur
Background Thirst is a sensation associated with a dry mouth and the desire or craving to drink water. Surgical patients are among those hospitalized individuals who are at high risk of developing both osmotic and hypovo-lemic thirst. Objectives To develop a new measurement tool for evaluating the thirst-related discomfort of surgical patients and to assess its validity and reliability. Methods The study population consisted of patients admitted to the surgical clinics of a research hospital in Turkey between January and March 2022. The new measurement tool was developed in several stages: a pilot implementation phase with 51 patients and the main implementation phase with 198 patients. Data were col-lected by means of face-to-face interviews with patients. Exploratory factor and confirmatory factor analyses were performed using IBM SPSS Statistics, version 22, and IBM SPSS Amos. Results The final Thirst Discomfort Scale consisted of 12 items in 3 subdimensions. The Cronbach α values of the scale subdimensions ranged from 0.787 to 0.848, and the Cronbach α value for the scale as a whole was 0.886. The scale explained 66.237% of the total variance of the data. Conclusion The Thirst Discomfort Scale consisting of 12 items and 3 subdimensions is a valid and reliable measurement tool for evaluating thirst-related discomfort of surgical patients.
AtıfScopus8WoS10OpenAlex11İncele - MakaleAçık Erişim2023Scopus SJRQ3Comparison of the removal efficiencies of Basic red 46 from aqueous solutiousing Aşkale lignite with and without ultrasound assisted processes
Karaca, Canan; Karaca, Melike; Kıranşan, Murat; Karaca, Semra; Açışlı, Özkan; Gürses, Ahmet
This study compared the removal efficiencies of Basic red 46 from aqueous solutions with and without ultrasound-assisted processes using lignite as a low-cost adsorbent. The effects of various experimental parameters such as contact time, adsorbent dosage, initial solution, pH, initial dye concentration and temperature on the dye removal efficiency were investigated. The experimental results were modelled by the kinetic and isotherm models. Both of processes fitted well to pseudo-second-order kinetics and the Langmuir model with highest correlation coefficients for all of three temperatures. The results showed that the influence parameters have a different effect on the removal efficiency in the presence and absence of ultrasonic irradiation. When the results obtained for both processes are compared, it is seen that the removal efficiency obtained with the ultrasound assisted process is much higher than that obtained with non-ultrasound assisted process at high dye concentrations. The removal efficiency of ultrasound-assisted and unassisted processes was found to be 81.5% and 54.6%, respectively, at 80 mg/L dye concentration and 60 min. Thermodynamic parameters showed that the adsorption process was spontaneous and exothermic. The enthalpy and entropy changes for the ultrasound-assisted process were –9.35 kJ/mol and –0.03 kJ/K·mol, respectively.
AtıfScopus6WoS5OpenAlex9İncele - MakaleAçık Erişim2023Scopus SJRQ1Investigation of Behavior on Solutions of Lane-Emden Complex Differential Equations by a Random Differential Transformation Method
Merdan, Mehmet; Merdan, Merve; Şahin, Ridvan
In this study, Lane-Emden complex differential equations have been randomized by selecting random variables for the coefficients, initial conditions, and force functions of complex differential equations. In addition, by finding the solutions of the obtained random complex differential equations, the probability characteristics of the solutions are examined. The random version of the differential transformation method (DTM) is used to obtain an analytical solution close to the solution of the random differential equation. Approximate expected values and variances are calculated using the approximate solution method. The solutions of some random complex differential equations obtained by using random probability characteristics with gamma, normal, and beta distributions were obtained by the DTM method. The probability characteristics obtained are shown graphically with the help of the MAPLE program.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ1Factors affecting decisions of farmers to produce geographical indication dry beans: a case from Turkey
Dogan, Nilgun; Adanacioglu, Hakan
Geographical indications (GIs) are defined as labels that show the relationship of a product with a certain region. They are of great importance in terms of distinguishing these products from the similar ones in terms of the quality that the characteristic features of the region bring to the product, making them stand out commercially, contributing to the rural development and preserving the cultural heritage. Dry beans cultivated by the farmers in the Gümüşhane province is newly recognized as a GI product that is unique in both taste and quality. This study is intended to identify the factors affecting the farmers’ decision to produce GI-labelled dry beans. The survey was conducted in January–March 2021. A sampling size of the participants consisted of 50 farmers who cultivated GI-labelled dry beans and 50 non-GI dry beans. A binary logistic regression analysis approach was employed to identify the factors affecting the likelihood of the farmers cultivating the GI dry beans. The results of the model indicate that the young farmers with the low educational level, the low property land size, the low yield per decare, and the large farmland, the high annual agricultural income and specializing in the dry beans production are more likely to engage in the production of GI dry beans. For the farms involving the GI product, agricultural associations can be advised with the farmers with the wider agricultural acreage and the high annual agricultural income, and that specialize in the production of such products. The participation of the farmers in the agriculture enterprises involving the GI dry beans will depend on them seeing positive widespread effects, which requires a long-term commitment.
AtıfScopus5WoS4OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2A New Approach for Ground Filtering of Airborne Laser Scanning Data Using PointNet++
Akbulut, Zeynep; Karsli, Fevzi; Dihkan, Mustafa
Ground filtering is an essential process that separates ground and non-ground points for generating digital elevation models (DEMs) from airborne laser scanning (ALS) point cloud data. Traditionally, ground filtering was carried out using rule-based approaches, but with the advancements in deep learning networks, ground filtering can now be performed using these methods. Deep neural networks (DNNs) require large amounts of training samples to reveal key information within the dataset. OpenGF is a new ultra-large-scale dataset which has nearly half a billion points from nine different scenes ranging from highly dense urban areas to steep vegetation covered mountains for ground filtering task. In this study, PointNet++ architecture was employed for ground filtering on the OpenGF dataset. Firstly, we slightly modified PointNet++ architecture’s sampling strategy to decrease the number of duplicate points in the batching process. We proposed a new adaptive tiling strategy based on input point cloud density to cope with highly varying point sampling of the OpenGF dataset. Modified PointNet++ architecture was trained with both adaptive tiling strategy and original OpenGF tiles to investigate the advantages and drawbacks of the proposed strategy on the ground filtering task. To evaluate the performance of the proposed strategy, the results for different test areas were compared with those obtained using the original PointNet++ and rule-based cloth simulation filtering (CSF) algorithms. Despite using fewer epochs, the proposed data collection strategy achieved up to 13% higher accuracy on test scenes with the modified PointNet++ architecture compared to the network trained with original OpenGF tiles.
AtıfScopus2WoS1OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ4An evaluation of the characteristic aftershock parameters following the 24 January 2020 MW = 6.8 Elazığ-Sivrice (Türkiye) earthquake
Öztürk, Serkan
A comprehensive evaluation of region-time-magnitude behaviours of aftershocks following the 24 January 2020 (Mw = 6.8) Elazığ-Sivrice (Türkiye) earthquake was achieved by using the characteristic parameters such as b-value, p-value, Dc-value and Mamax value of aftershock occurrences. The b-value was calculated as 0.82 ± 0.02 by considering the magnitude of the completeness value as Mcomp = 1.9, and it is relatively small compared to typical b ≈ 1 for the magnitude-frequency relationship of aftershocks. This low b-value may also be caused by the abundance of aftershocks with ML ≥ 4.0. The p-value was computed as 0.80 ± 0.02 with c-value = 0.279 ± 0.098 and is smaller than the global value of p ≈ 1. This low p-value may be due to a relatively slow decay rate of aftershock activity, and the modified Omori model seems appropriate for the estimation of decay parameters. The Dc-value was estimated as 1.87 ± 0.07. This large value shows that aftershocks are homogeneously distributed and more clustered at larger scales/in smaller areas. The temporal variation of b-value indicates that decreases in b-value may result from the gradual increase in the effective stress following the larger aftershocks. The lowest b-values and Mamax values greater than 5.0 were observed in the north, south and southwest parts of the mainshock including Pütürge and Erkenek segments. These results show that there is an apparent relation between the smallest b-values and the largest Mamax values. The largest p-values were estimated in and around the main shock including Pütürge segment. The regions with the smallest b-value and the largest p-value have high stress and coseismic deformation, respectively. Stress variations and coseismic deformation are extremely effective on the changes of b-and p-values. As a remarkable result, aftershock hazard following the mainshock may be considered extremely related to aftershock parameters, and detailed analyses of the region-time-magnitude characteristics of aftershocks are recommended for a preliminary evaluation following the mainshock.
AtıfScopus3WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2The effect of the surface morphology of the aluminium oxide layer on the physical and bacterial attachment behavior
Kaya, Şevval; Sarıbıyık, Oğuz Yunus
Coating of the metal surface for different fields such as corrosion resistance, hydrophobic surface, and conductivity properties enhance the material quality for different application. Furthermore, controlling the morphological structures and the size of the coating materials is one of the most important factors for designing their functionality. The new approaches to the effect of surface properties at the atomic level on bacterial adhesion offer new perspectives on this subject. In this study, the effect of the different current densities on the morphological microstructural features, microhardness properties, and bacterial attachment behavior of the protective aluminum oxide layer was investigated by using different analytical and instrumental methods. The Staphylococcus aureus was used as a model bacteria for attachment tests. The result presented in the current study exhibited that the crystal morphology, microhardness, and bacterial adhesion features have changed depending on the applied current density. Increasing the current density from 1.5 to 1.7 raises the microhardness from 88 to 126 (Vickers) and causes higher surface roughness by 56 nm, 114 nm and 124 nm respectively. The high number of the attached bacteria were determined on the more roughness surface during the study.
AtıfScopus3WoS2OpenAlex3İncele - MakaleYalnız künye2023Scopus SJRQ1Investigating the environmental Kuznets curve hypothesis with recovered paper consumption, human development index, urbanization, and forest footprint
Aydin, M.; Koc, P.; Tumay, M.
The aim of this study, which covers the period from 1991 to 2017, is to analyze the relationships between recovered paper consumption, human development index, urbanization rate, and forest footprint in the framework of the Environmental Kuznets Curve (EKC) hypothesis in the 10 countries that consume the most recovered paper. Considering that wood is the raw material of paper, the study investigates whether the increase in the consumption of recovered paper has a positive effect on the forest footprint. Therefore, unlike other studies, the dependent variable of the EKC model is the forest footprint. The study is original in that it is the first to analyze the effects of recovered paper consumption on environmental degradation in the context of the EKC hypothesis. To analyze the relationships between the variables, we use panel cointegration tests based on AMG and CCE estimators, which allow analysis on both a country and group basis. According to the results, the EKC hypothesis is valid only in the Netherlands. While there is a statistically significant and negative relationship between recovered paper consumption and forest footprint in the Netherlands, there is a statistically significant and negative relationship between urbanization and forest footprint in Italy. Economic and ecological benefits and costs must be considered to measure the net benefit of waste management programs. In addition, to analyze how environmental impacts change over time, ecological footprint and gas emissions during waste generation or disposal should be measured similarly to carbon emissions.
AtıfScopus14WoS14OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ1Modelling some stand parameters using Landsat 8 OLI and Sentinel-2 satellite images by machine learning techniques: a case study in Türkiye
Bulut, Sinan; Günlü, Alkan; Çakır, Günay
Remote sensing technologies have been extensively used in forest management in predicting stand parameters. The goal of this study is to use Landsat 8 and Sentinel-2 satellite images to estimate stand volume, basal area, number of trees, mean diameter, and top height. 180 temporary sample plots were taken in pure Crimean pine stands with varied structure. Reflectance, vegetation indices, and eight texture values were generated from Landsat 8 and Sentinel-2 satellite images. The stand parameters were modelled with the remotely sensed data using multiple linear regression, support vector machine, and deep learning techniques. The results showed that the support vector machine technique provided the highest level of model performance with 45° orientation for number of trees (R2 = 0.98, RMSE%=5.97) and 90° orientation for basal area (R2=0.91, RMSE%=15.22). The results indicated that the texture values presented better results than the reflectance and the vegetation indices in estimating the stand parameters.
AtıfScopus12WoS12OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ2Rheumatic diseases and gut microbiota publications in 2002–2022: a Scopus‑based bibliometric analysis
Kocyigit, Emine; Kocak, Tevfik
Rheumatic diseases (RDs) include a variety of autoimmune disorders defined by severe inflammation, primarily affecting the joints, tendons, ligaments, bones, and muscles. Recent research has revealed the association between rheumatic diseases and gut microbiota, thereby providing insights into the underlying mechanisms of disease pathogenesis. The objective of this study was to evaluate the quantity and quality of scientific research regarding the association between RDs and gut microbiota, as well as to elucidate the characteristics of worldwide research output in this field. The present bibliometric analysis was carried out using the Scopus database, using the keywords "rheumatology," "arthritis," and "gut microbiota." The study involved determining the number of articles, the number of active countries with journals, the identification of prolific authors, and the collection of citation data. Additionally, analyses of trends were conducted. 503 articles in all were reviewed. Collaboration networks were visualized using mapping techniques. The number of articles on RDs and gut microbiota exhibited a consistent pattern from 2002 to 2022 (p < 0.05). The five most productive countries were China (n = 128; 25.45%), the United States (n = 101; 20.07%), Italy (n = 40; 7.95%), the United Kingdom (n = 20; 3.98%), and Japan (n = 17; 3.38%). Israel, Italy, Belgium, and Portugal had the highest values regarding the number of articles per million population. Australia, Canada, and the United Kingdom were the top three countries regarding average citation count. This bibliometric analysis evaluates and synthesizes global scientific output on RDs and gut microbiota. The literature on the association between rheumatic diseases and gut microbiota is growing. Supporting researchers in countries with limited involvement in this field will contribute to its growth.
AtıfScopus6WoS7İncele - MakaleYalnız künye2024Scopus SJRQ2Earthquakes as a natural occurrence and disaster: A qualitative research from the perspective of chaos theory
Yildiz, Eyyüp; Bostan, Sedat
A concept that inspired social sciences as well as many other fields of science was developed from chaos theory. Disaster researchers are also trying to approach, understand, explain and manage disasters with this new concept. However, it has been observed that studies investigating disasters from this perspective do not focus on disaster sources. With this starting point, in this research, the chaotic factors that prepare the disaster formation were investigated with the example of earthquake. The study was carried out with the qualitative method. Data were collected by semi-structured online interview. Participants were selected by purposive sampling method. The interview data obtained from a total of 10 participants were managed with the MAQXDA 2018 software package using the traditional content analysis method. All codes were classified into three themes and 11 categories. According to the findings, earthquakes can be dealt with in three different chaotic periods: a natural event, a natural event that turns into a disaster, and disaster response and recovery. Future research is recommended to explain the dynamics of occurrence of other disasters such as floods, storms, explosions, and epidemics. It is recommended that disaster management practitioners integrate the chaos management approach into disaster management. With this, it is hoped that disaster management will shift from a linear, bureaucratic, command-control approach to a community-based, flexible, continuous planning approach in which even the smallest occurrences are carefully monitored.
AtıfScopus4WoS3OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ2Fast building detection using new feature sets derived from a very high-resolution image, digital elevation and surface model
Günen, Mehmet Akif
Detecting building rooftops with very high-resolution (VHR) images is an important issue in many fields, including disaster management, urban planning, and climate change research. Buildings with varying geometrical features are challenging to detect accurately from VHR image due to complicated image scenes containing spectrally similar objects, illumination, occlusions, viewing angles, and shadows. This study aims to detect building rooftops with high accuracy using a new framework that includes VHR image, visible band difference vegetation index, digital surface and elevation models, the terrain ruggedness and the topographic position index. Five distinct feature sets were generated in order of importance by exposing the ten related stacking features to a feature selection procedure using the maximum relevance minimum redundancy method. Then, Auto-Encoder, k-NN, decision tree, RUSBoost, and random forest machine learning algorithms were utilized for binary classification. Random forest yielded the highest accuracy (97.2% F-score, 98.72% accuracy) when all features (F10) were used, while decision tree was the least successful (59.16% F-score, 83.56% accuracy) for RGB feature set (FRGB). It was revealed that classification of F10 with random forest increased F-score by about 23% compared to classification with FRGB. Additionally, McNemar’s tests showed no statistically significant difference between random forest vs k-NN and decision tree vs RUSBoost.
AtıfScopus19WoS16OpenAlex17İncele - MakaleAçık Erişim2024Scopus SJRQ4Investigation of friction behavior of TiO2: Al2O3 composite coating formed on AA2024 alloy by micro-arc oxidation
Boynueğri̇ Kaplan, Emine; Şüküroğlu, Ebru Emine
In this study, an alumina (Al2O3) ceramic coating and a composite coating containing titanium dioxide (TiO2) particles were prepared on surfaces of AA2024 substrates by micro-arc oxidation (MAO) treatment. The effects of micro-sized (≈20-30 µm) TiO2 particles incorporated into electrolyte on the microstructure, phase and chemical composition, thickness, and friction behavior of the coating were investigated. The surface morphologies of the coatings were analyzed by scanning electron microscopy (SEM). The phase and chemical compositions of the coatings were evaluated by means of X-ray diffraction (XRD) and energy-dispersive X-ray spectrometry (EDS), respectively. The friction coefficient of the coatings was investigated using a pin-on-disc tribometer under condition of dry slip sliding. Moreover, the wear tracks were analyzed by SEM. Addition of TiO2 particles into the electrolyte resulted in the reduction in number of pores and formation of smaller and more uniform pores in comparison with the Al2O3 ceramic coating. XRD analyses demonstrated that the TiO2:Al2O3 composite coating was composed of anatase-TiO2 and rutile-TiO2, as well as pure aluminum, α-Al2O3 and γ-Al2O3 which are the primary phases. The friction tests showed a significant reduction in the friction coefficient of the composite coated samples which contains titanium oxide (TiO2) particles in comparison with Al2O3 coated and uncoated samples. Copyright 2021, Yıldız Technical University.
AtıfScopus1WoS1İncele - MakaleYalnız künye2023Scopus SJRQ3A Numerical Study to Evaluate the Changes in Dynamic Properties of Various Steel Truss Types Under Fire Conditions
Sibil, R.; Ozyurt, E.
This study numerically examines the changes in dynamic properties of fire-damaged steel trusses made of square hollow sections subjected to uniform and non-uniform heating scenarios. After verifying the numerical models at both ambient and elevated temperatures, a vast number of the simulations were analysed using non-linear finite element software to evaluate the effects of fire scenarios, truss types, and fire-damaged levels on the fire dynamic characteristics of square hollow section Warren, Howe, and Pratt trusses. The results indicated that the natural frequency of steel trusses significantly decreased as the fire-damaged level increased. In the case of local fire, the natural frequencies of the trusses began to drop suddenly at temperatures above 550 °C. Whereas the drop in the natural frequency of the uniformly heated trusses started at even much lower temperature levels. Moreover, the decrease in the natural fundamental frequencies of the uniformly heated trusses was lower than the reduction rate of the modulus of elasticity at high temperatures due to the large non-linear deformations. Since the modification of the stiffness of the truss by simply the reduction factor of the elastic modulus of the steel may be inappropriate to calculate the fundamental frequency of the trusses in the local and global fires, a new method was introduced to calculate the fundamental frequency value of the steel trusses in the fire.
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