Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(20)
- Celik, Erkan(12)
- Mete, Suleyman(11)
- Serin, Faruk(10)
- ALMisned, Ghada(9)
- Güler, Ömer(8)
- Yucesan, Melih(8)
- Tekin, H.O.(7)
- Artuğer, Fırat(6)
- Utku, Anıl(6)
- Guler, Omer(5)
- Özkul, İskender(5)
- Şimşek, Telem(5)
- Acar, Ramazan(4)
- Basgoz, Oykum(4)
- Guler, Seval Hale(4)
- Şimşek, Tuncay(4)
- Bahceci, Ersin(3)
- Baykal, Duygu Sen(3)
- Başhan, Veysi(3)
- Canbay, Canan Aksu(3)
- Demirel, Hakan(3)
- Doğan, Gürkan(3)
- Ergen, Burhan(3)
- Gul, Ali Oktay(3)
- Güler, Seval Hale(3)
- Gülmez, Nihan(3)
- Karaduman, Oktay(3)
- Kavaz, Esra(3)
- Kaya, Sema Kayapinar(3)
- Onder Erguven, Gokhan(3)
- Yayla, Nihal(3)
- Yildirim, Nuran Cikcikoglu(3)
- Özkaynak, Fatih(3)
- Ak, M. Fatih(2)
- Albayrak, M. Gökhan(2)
- Aslan, Serpil(2)
- Aycin, Ejder(2)
- Can, Umit(2)
- Cemalgil, Selim(2)
Yayınlar
- Kitap BölümüYalnız künye2023An IT2FBWM Model to Highlight the Significance of Factors Utilized in Determining Pandemic Hospital Site Selection
Aycin, Ejder; Kayapinar Kaya, Sema; Ecer, Fatih
The COVID-19 pandemic has spread to the world in a short time since its emergence in Wuhan, China, and mobilized international health authorities with its effects, continues its development seriously. Due to the fast spread of COVID-19, governments have made some decisions to build new temporary hospitals for patients infected with COVID-19. This situation increased the importance of the site selection process for a pandemic hospital during the current critical time. Site selection of a hospital can be considered as multi-criteria decision-making (MCDM) problem since it includes multiple factors. This paper applies an analytical tool for evaluating the criteria of the site selection of a pandemic hospital. For this purpose, the extended best–worst method with trapezoidal interval type-2 fuzzy numbers (IT2FBWM) is employed to determine the importance weights of the pandemic hospital site selection criteria. The paper’s findings point out that the IT2FBWM model can help decision-makers determine the importance weights of the criteria used in the pandemic hospital siting decisions.
AtıfScopus1OpenAlex2
İncele - MakaleAçık Erişim2023Scopus SJRQ2Effects of İnclined Plate in a Channel to Control Melting of PCM in a Body İnserted on the Bottom Wall
Öztop, H.F.; Bakır, E.; Selimefendigil, F.; Gür, M.; Coşanay, H.
A two-dimensional time-dependent computational analysis was carried out to examine the effects of inclined plate on melting time of Phase Change Material (PCM) filled square block on the bottom wall of a channel. Solution of the governing equations are performed by using finite volume method. The RT25HC material is chosen as PCM. The study is done for different parameters of inclination angle of the plate and Reynolds number. It is observed that the inclined plate can be used to control of melting time of PCM in a block as well as flow field and temperature distribution in the channel. Using of acceleration angle as θ = 110° accelerates the melting time of PCM inside the block. Thus, mass fraction rate increases 4 times with application of inclined thin plate.
AtıfScopus31WoS27OpenAlex29
İncele - Kitap BölümüAçık Erişim2023Scopus SJRQ4The Effects of Knowledge Extraction Approaches on Cryptanalysis Studies and Analysis of the Success of Chaos-Based Countermeasures
Bürhan, Yücel; Özkaynak, Fatih
Each new approach and scientific progress provides many advantages and innovations from theory to practice yet, its disadvantages should be evaluated comprehensively from different perspectives. In this study, the effects of knowledge extraction approaches on the cryptanalysis process have been evaluated. It is known that the secret key of the encryption algorithm can be obtained by using knowledge extraction approaches, especially with application oriented attacks such as side channel analysis. It is known that chaotic masks can be used as a countermeasure to prevent the success of these attacks. In this study, side-channel analyzes of the chaos-based substitution box structures that have been proposed in recent years have been carried out. The side channel analysis results of the existing studies in the literature have been carried out for the first time in this study. The results obtained showed that the approaches in the field of knowledge extraction should be handled more comprehensively in the cryptanalysis processes, and also pointed out that a new evaluation criterion should be analyzed for future studies for chaos-based design studies.
AtıfScopus2OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ3Evaluation of social factors within the circular economy concept for European countries
Kaya, Sema Kayapinar; Ayçin, Ejder; Pamucar, Dragan
The circular economy (CE) is a rapidly growing theme, particularly in the European Union (EU), that encourages the responsible and circular use of resources in the field of contributing to long-term development. The environmental and economic magnitude of development are frequently debated in the subject of CE whereas, social aspects have been only rarely and sporadically combined into the CE. Therefore, this study involves a multidisciplinary holistic framework of clustering methods and Multi-Criteria Decision Making (MCDM) for evaluating the CE paradigm in relation to EU countries' social growth. In terms of the social impact of CE strategies, the k-means cluster analysis was used to group the 27 EU members with similar social impact levels. Subsequently, a novel integrated CRITIC (The criteria importance through intercriteria correlation) and MEREC (Method based on the Removal Effects of Criteria) methods were employed for determining the weights of social indicators in order to balance the two weighting methods. In order to select the best country in each cluster, a novel extension of the hybrid MARCOS (Measurement of Alternatives and Ranking according to Compromise Solution) method combined with Power averaging and Heronian operator was developed. According to final solutions, Western European countries in the first cluster have the lowest unemployment and corruption rates, with the Netherlands having the best performance in this cluster. The second cluster includes countries with the lowest employment rates following university graduates between the ages of 20 and 64. Accordingly, Croatia is the best social performance in this cluster. Countries with the highest income distribution and unemployment rate are in the 3rd cluster, the best country in this group is Lithuania. Finally, the results obtained from the innovative MCDM methods have validated in order to demonstrate the proposed methodology's applicability.
AtıfScopus30WoS23OpenAlex42İncele - MakaleYalnız künye2023Scopus SJRQ2Effect of Using Eccentric Braces with Different Link Lengths on the Seismic Demand of CFST Column-Composite Beam Frames Subjected to Near-Field and Far-Field Earthquakes
Etli, Serkan; Güneyisi, Esra Mete
In recent years, in the light of technological developments, the utilization of composite members that enable the use of superior properties of concrete and steel together in earthquake-resistant building design has become widespread. In this study, 5-, 8-, 10-, 13- and 15-story composite moment-resisting framed buildings were designed using composite beams and concrete filled steel tube columns. The effect of using steel braces and the variation of the link length of the eccentric steel braces on the seismic demand of the composite buildings were investigated. For this, eight different cases with braces were considered and compared with the bare structure. The first case had concentric braces (having no link), and the other seven cases had eccentric steel braces with different link lengths classified as short, medium and long. The nonlinear dynamic response of braced and non-braced composite structures was evaluated under the effect of earthquake groups of far-field, near-field with and without pulse effects. Each earthquake group includes ten different ground motion records. SeismoStruct which is a fiber element-based software was used in modeling and analysis of the structures. Seismic behavior of the case studied structures was investigated comparatively through the demand parameters such as the maximum inter-story drift ratios, the maximum roof drift ratios and the deformation states in the structural elements. It was observed that the inclusion of the steel braces provided significant gains in dissipating seismic energy acting through composite buildings and the beam/column deformations decreased considerably, depending on the length of the link and the height of the structure. In some cases, significant damage was monitored in the link members; however, this type of deformation was limited.
AtıfScopus3WoS3OpenAlex18İncele - MakaleYalnız künye2023Scopus SJRQ2Aluminum Recovery by Acid Leaching of Variously Enriched Pyrophyllite Ore: Effects of Pre-treatment Methods for Activation
Aydoğmuş, Ramazan; Erdemoğlu, Murat; Uysal, Turan
Effects of pre-treatment methods such as calcination for thermal activation and intensive milling for mechanical activation on the aluminum (Al) recovery by acid leaching of preliminarily enriched pyrophyllite ore via attrition scrubbing and froth flotation were investigated. XRD patterns of the calcined and the intensively milled samples were compared to determine the changes during the pre-treatment processes. Hot HCl solution was used for dissolution of aluminum to determine the Al recoveries from variously enriched and variously pre-treated pyrophyllite ore samples. Specific thermal and milling energies consumed per unit amount of ore were calculated, and the ideal activation method was suggested by comparing the activation methods in terms of energy consumption. Mechanical activation of the pyrophyllite concentrate obtained by attrition scrubbing rather than froth flotation was suggested for higher recoveries of aluminum from by acidic leaching. It was determined that operating cost (in terms of energy) of the mechanical activation is lower and aluminum recovery is higher than thermal activation. It was concluded that mechanical activation instead of thermal activation is more economical and environmentally friendly method.
AtıfScopus5WoS4OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of pea/rice and amylopectin/chromium as an alternative protein source to improve muscle protein synthesis in rats
Ozdemir, Oguzhan; Erten, Fusun; Er, Besir; Orhan, Cemal; Komorowski, James R.; Sylla, Sarah; Perez Ojalvo, Sara; Sahin, Kazim
Background: A preclinical study reported that the combination of an amylopectin/chromium complex (ACr) of branched-chain amino acids (BCAA) significantly enhanced muscle protein synthesis (MPS). This study was conducted to determine the effects of the addition of ACr complex to a pea/rice (PR) protein on MPS, insulin, muslin levels, and the mTOR pathway in exercised rats. Methods: Twenty-four rats were divided into three groups: (i) exercise (Ex); (ii) Ex + PR 1:1 blend (0.465 g/kg BW); (iii) Ex + PR + ACr (0.155 g/kg BW). On the day of single-dose administration, after the animals were exercised at 26/m/min for 2 h, the supplement was given by oral gavage. The rats were injected with a bolus dose (250 mg/kg BW, 25 g/L) of deuterium-labeled phenylalanine to determine the protein fractional synthesis rate (FSR) one h after consuming the study product. Results: The combination of PR and ACr enhanced MPS by 42.55% compared to the Ex group, while Ex + PR alone increased MPS by 30.2% over the Ex group (p < 0.0001) in exercised rats. Ex + PR plus ACr significantly enhanced phosphorylation of mTOR and S6K1 (p < 0.0001), and 4E-BP1 (p < 0.001) compared to the Ex (p < 0.0001). PR to ACr also significantly increased insulin and musclin levels (p < 0.0001) in exercised rats. Additionally, compared to Ex + PR alone, Ex + PR + ACr enhanced mTOR (p < 0.0001) and S6K1 (p < 0.0001) levels. Conclusion: These data suggested that PR + ACr may provide an alternative to animal proteins for remodeling and repairing muscle by stimulating MPS and mTOR signaling pathways in post-exercised rats. More preclinical and clinical human studies on combining pea/rice and amylopectin/chromium complex are required.
AtıfScopus4OpenAlex4
İncele - MakaleYalnız künye2023Scopus SJRQ1A novel two-phase group decision-making model for circular supplier selection under picture fuzzy environment
Kaya, Sema Kayapinar
Circular supply chain management (CSCM), which incorporates circular thinking into supply chain management, promotes supply chain sustainability by offering a novel and compelling viewpoint. In the CSCM, supplier selection is crucial in establishing a competitive edge among businesses by decreasing environmental degradation and related supply chain expenses. This paper aims to propose a novel two-phase group decision-making approach, which combines the picture fuzzy Analytical Hierarchical Process (PF-AHP) and grey Measurement of Alternatives and Ranking According to Compromise Solution (MARCOS-G) model to select railway material suppliers within the scope of circular economy perspective. In group decision-making, a picture fuzzy number-based approach aggregates individual decision makers’(DMs) opinions and provides a lower level of computing complexity and a higher level of performance. The PF-AHP has been used to produce the weights of the criteria, and the MARCOS-G technique has been used to rank the suppliers and choose the most appropriate one. The results and verification of the novel method are carried out throughout a comprehensive sensitivity analysis. For this purpose, 50 scenarios with changes in the weight values of criteria were developed. In the validation analysis, a comparison with other grey COPRAS, TOPSIS, ARAS and WASPAS methods were performed. Due to the ranking results obtained from Spearman’s correlation analyses, the MARCOS-G is almost consistent and it can be seen that the A4 remains the top supplier in all 50 scenarios.
AtıfScopus34WoS30OpenAlex39İncele - MakaleYalnız künye2023Scopus SJRQ2Graphene nanoplatelet-reinforced high entropy alloys (HEAs) through B4C incorporation: structural, physical, mechanical, and nuclear shielding properties
Gul, Ali Oktay; Kavaz, Esra; Basgoz, Oykum; Guler, Omer; ALMisned, Ghada; Bahceci, Ersin; Guler, Seval Hale; Tekin, H.O.
This study aims to explicate the diverse roles of high entropy alloys within nuclear environments. The study extensively investigates the impact of B4C on the structural, physical, mechanical, and nuclear shielding properties of synthesized high-entropy alloys (HEAs) comprising FeNiCoCrW, GNP, and B4C. The aim is to explore the monotonic effects of B4C on the behavioural changes of the HEAs. The present study initially investigates the internal morphology and structural characteristics of the produced composites through the utilization of X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The determination of coefficient of friction values is obtained via wear testing, wherein the values are measured as a function of the sliding distance. The shielding properties of nuclear radiation are determined through the experimental setups for gamma-ray and neutron radiation. The sample encoded as G2, which incorporates both B4C and GNPs as reinforcing agents, exhibits the most noteworthy mechanical properties among the samples that were examined. The findings of our study indicate that augmenting the concentration of B4C has a significant impact on the efficacy of nuclear radiation shielding. The present study infers that the B4C produced within the framework of GNPs plays a significant role in enhancing the overall characteristics of HEAs. This is particularly noteworthy in the context of nuclear applications, where HEAs are being examined as a prospective constituent of forthcoming nuclear reactors. Moreover, B4C serves as a versatile instrument in scenarios, where there is a need to enhance mechanical and nuclear shielding properties across a spectrum of radiation energies.
AtıfScopus15OpenAlex16İncele - MakaleYalnız künye2023Scopus SJRQ2Investigation of Leaching Kinetics of Molybdenum from MoO3 Concentrate in Ammonia–Ammonium Nitrate Solutions
Karacahan, Mehmet Kayra
MoO3 is a widely accessible foundation material and the primary compound used to produce numerous molybdenum products. The ore was first roasted, and the leaching behavior of concentrated molybdenite mineral was assessed. The optimal conditions for the leaching process were identified in the second step, and in a subsequent stage, the process' kinetics were assessed. Ammonia and ammonium nitrate concentration were used as independent variables in the trials, and the central composite design approach was used to analyze the results. At the conclusion of the tests, the optimum concentrations of ammonia and ammonium nitrate were found to be 2.42 mol/L and 1.86 mol/L, respectively. On the rate at which molybdenum leached from MoO3, the influences of temperature, stirring speed, solid-to-liquid ratio, and particle size were investigated. It was found that the leaching rate increased when temperature and stirring speed increased, along with decreasing the solid-to-liquid ratio and particle size. Leaching efficiency of molybdenum (93%) such as temperature 20 °C, 1.859 mol/L ammonium nitrate concentration, 2.419 mol/L ammonia concentration, solid/liquid ratio 6/100 g/mL, stirring speed 400 rpm, and average particle size 0.115 mm optimum conditions have been achieved. The kinetic study proposed a mathematical model for the leaching process, which revealed that the leaching kinetics matched the Avrami model. This process' activation energy was determined to be 22.66 kJ/mol. Calcium molybdate is used in various fields, such as construction, transportation, anti-corrosion pigments, and flame retardants. Graphical Abstract: [Figure not available: see fulltext.]
AtıfScopus8WoS7OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ3Comprehensive Evaluation of the Relationships Between Grape Skin Color/Ripening Time and Antioxidative Capacity, Some Phytochemicals, and Fatty Acid Compositions of Their Seeds
Çakır, Atilla; Odabaşıoğlu, Mehmet İlhan; Karaca Sanyürek, Nesrin; Aydın, Sevinç
It has been proven that grapes, which are widely cultivated around the world, have positive health effects. However, the phytochemical composition of lesser-known local varieties of Vitis vinifera L., which has a very wide range of varieties, is still being studied. The aim of this study was to determine the effects of skin color and ripening time on the phytochemical compositions of grape seeds. As a plant material local grape varieties cultivated in Southeastern Anatolia (Turkey) were used. The results showed that grape skin color has an effect on vitamin K1, vitamin K2, vitamin D3, δ‑tocopherol, stigmasterol, ergosterol, myristic acid, oleic acid, trans-elaidic acid, and the monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) contents of seeds. The seeds of grape varieties with colored skins were richer in K2, D3, stigmasterol, oleic acid, trans-elaidic acid, and MUFAs, while the seeds of grape varieties with white skins were richer in K1, δ‑tocopherol, ergosterol, and SFAs. The ripening time of the grapes was found to have a partial effect on the fatty acid compositions of the seeds, but without any effect on linoleic acid contents. As the ripening time was delayed, there was an increase in oleic acid and MUFA contents of the seeds, while there was a decrease in SFA contents. In general, increased vitamin K1 contents of the seeds were parallel to decreases in vitamins K2, D2, and D3, as well as α‑tocopherol content and antioxidant activity. The seeds of grape varieties that have colored skins were found to have more suitable compound compositions for use in the production of functional foods that support human and animal health. In addition, it was concluded that grape berries that ripen late may be more favorable for grapeseed oil production.
AtıfScopus3WoS4OpenAlex3İncele - MakaleYalnız künye2023Scopus SJRQ2Novel electrochemical sensor of nebivolol drug used for treatment of hypertension and chronic heart failure
İpek, Yeliz; Koçak, Berna
Nebivolol is a beta-blocker used to treat high blood pressure and heart failure. Nebivolol is a cardiovascular drug in the group of selective beta-blockers (with selective action on the cardiovascular system). It prevents the increase in heart rate and controls the pumping power of the heart. It also has a dilating effect on blood vessels and helps to lower blood pressure with this effect. The ability to analyze nebivolol quickly, simply, economically and reliably is of high importance in two cases. The first is to adjust the drug dosage to be used by the patients, and the second is to provide fast intervention in the drug production process as a result of fast and accurate quality control in drug production and to provide quality control of produced tablets. Since, the boric acid has a good catalytic activity and enhances the peak current intensity, a boric acid‒glutardialdehyde-modified glassy carbon electrode was designed for investigation of electrochemical behavior and quantitative determination of nebivolol (NBV) in this study. Electrochemical reaction peak and the peak current intensity changes with changing NBV concentration provide detection of NBV. The role of glutardialdehyde was to immobilize the boric acid on the electrode surface with its crosslinking ability. The designed electrode was achieved by dropping boric acid‒glutardialdehyde mixture on glassy carbon electrode and drying it at room conditions. By using boric acid‒glutardialdehyde-modified glassy carbon electrode (BA‒GA2/GCE), quantitative analysis of the active drug ingredient (NBV), which is widely used in the treatment of hypertension and chronic heart failure, was carried out sensitively, selectively and at low detection limits with low cost. This electrode exhibited good repeatability and stability for detection of the oxidation peak of NBV. In addition, the working ranges and detection limits of NBV were determined in the optimum experimental conditions. SWV technique was used and according to the results obtained, LOD values for NBV in BR buffer (pH 9) and in urine samples were 1.0 × 10−7 mol L−1 and 4.12 × 10−7 mol L−1, respectively. The feasibility of the developed novel sensor was demonstrated by performing recovery studies with tablet and urine samples containing NBV. The recovery results were 93.10% and 58.16% for urine and tablet samples, respectively. Graphical abstract: [Figure not available: see fulltext.]
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of metal pollution related to human health risk in freshwater snail Viviparus contectus (Millet, 1813) as a potential bioindicator species in Lake Habitat (Turkey)
Kutluyer Kocabaş, Filiz; Göktürk Aksu, Emsiye; Kocabaş, Mehmet
Freshwater mollusks are employed as bioindicators for the assessment of water quality in biomonitoring studies since the water quality of natural resources is crucial for humans. The freshwater snail species known as Viviparus contectus (Viviparidae: Gastropoda) is one that people eat. Here, the levels of heavy metals (Cd, Cr, Pb, As, Zn, and Cu) in water and V. contectus samples were determined. An Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES, Spectro Arcos, vertical plasma) was used for the analysing the heavy metal concentrations in water and freshwater snail samples. The results of the current investigation demonstrated that freshwater snails accumulated metals in their water and soft tissues in the following orders: Pb > Cr = Zn = Cu = Cd = As and Zn > Cu > Pb > Cd > As = Cr. Autumn was the time of year when higher amounts of heavy metals (As, Cr, Cu, Zn, and Hg) were found. Pb content in the freshwater snail samples was strongly impacted by seasonal fluctuations (P 0.05). For adults, the EDI (estimated daily intake) values were lower than the TDI (tolerable daily intake) values, and the HI (hazard index) values were below 1. Freshwater snail samples had Zn and Pb levels that were over the FAO/WHO, Turkish Food Codex, JECFA, and EC limit values. Except for Pb, the water study shows mean metal concentrations below the USEPA, Turkish Pollution Control Regulation, and World Health Organisation maximum allowed levels. Aquatic ecosystems were negatively impacted by anthropogenic activities overall, and this study can provide a helpful data set for investigations on metallic contamination in water bodies and biomonitoring in freshwater ecosystems.
AtıfScopus7WoS6OpenAlex6İncele - MakaleYalnız künye2023Scopus SJRQ2Microplastic pollution in two remote rivers of Türkiye
Gündoğdu, Sedat; Kutlu, Banu; Özcan, Tahir; Büyükdeveci, Ferhat; Blettler, Martin C. M.
Microplastic pollution in aquatic ecosystems presents an emerging environmental threat that can have adverse effects on ecology, endanger aquatic species, and result in economic damage. Despite the numerous studies reporting the presence of microplastics in marine environments, research into their presence in freshwater systems or inland waters remains limited. This study aimed to assess the level of microplastic pollution transported by the Munzur and Pülümür Rivers and some small rivers that flow into the Uzunçayır dam lake, which is the confluence of the Munzur and Pülümür Rivers in Türkiye. Samples were collected from 23 stations, with the concentration of microplastics ranging from 0.01 MP/m3 at P-4 station to 28.21 MP/m3 at P-10, a station located near a city. Microplastics comprise four types: fiber, film, fragment, and glitter. The average size of microplastics was 1.46 ± 0.05 mm, with the average size of fibers, films, fragments, and glitter-type microplastics being 1.58 ± 0.07 mm, 1.23 ± 0.10 mm, 1.21 ± 0.11 mm, and 0.78 ± 0.16 mm, respectively. The most frequent polymers were polyethylene (31.8%), polystyrene (21.1%), and polypropylene (10.5%). Despite being considered remote and less populated rivers compared to other river systems in Türkiye, all sampling sites showed varying concentrations of microplastics.
AtıfScopus34OpenAlex37İncele - MakaleYalnız künye2023Scopus SJRQ2An Estimation Proposal for Engineering Properties of Modified Concrete by using Standalone and Hybrid GRELM
Cemalgil, Selim; Onat, Onur; Aruntaş, Hüseyin Yılmaz
The presented study pertains to an attempt to propose a novel prediction model to predict the flexural and compressive strengths of concrete modulated using steel fiber (SFb) and silica fume (SF). A completed experimental investigation is adopted for the current study, and a research plan is employed. Three different superplasticizers amount (SP), different SF replacement ratios, and a constant amount of SFb were used by the weight of cement to meet the C25 target strength. A sum of 16 distinct mixtures designed by changing SP and SF ratios were developed. Furthermore, SFb was added at a fixed rate of 65 kg/m3 to all planned concrete mixes. In addition, SFb was used to create a 16-mix design. Finally, a total of 32 distinct mix designs were created. Produced, hardened specimens were exposed to two different curing conditions. This research uses the mechanical characteristics of concrete treated with SF, SP, and SFb to estimate by conducting standalone and hybridized generalized extreme learning machine (GRELM) algorithms based on available experimental data in terms of the metaheuristic aspects of this work. With continuous input data, four separate data sets were constructed. Compressive strength and flexural strength were estimated separately. With the aid of the Grey Wolf Optimization (GWO) and Particle Swarm Optimization (PSO) algorithms, binary and ternary hybrid approaches were developed and tested on the data. Four distinct estimation models were suggested. Two quality metrics were used to evaluate the estimation performance: Root Mean Square Error (RMSE) and correlation of determination (R2). The estimation results showed that the hybridized GRELM-PSO-GWO estimation model that was built for prediction was relatively successful in all sets.
AtıfScopus4WoS3OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2Chaotic quantization based JPEG for effective compression of whole slide images
Artuğer, Fırat; Özkaynak, Fatih
In today’s digital world, effectively transferring data from one point to another is an important problem. For this reason, the development of various new compression algorithms and making existing solutions more effective are examined in detail by researchers. In this study, a new method is proposed to improve the performance of JPEG algorithm. The proposed method includes an approach based on chaotic systems. Chaotic systems contain a strong entropy source. This powerful source of entropy has strong practical applications in obtaining statistically robust random values. In this study, a method is proposed to obtain quantization tables effectively by taking advantage of this potential of chaotic systems. The obtained results showed that the compression performance can be increased at the same quality factors. The proposed approach has been tested on the whole slide image (WSI) dataset. Looking at the analysis results, an average of 2.43% higher accuracy was achieved compared to the JPEG algorithm. It is thought that these results can provide an advantage especially in transferring high-dimensional images such as the DICOM standard, where the JPEG algorithm is used in practical applications.
AtıfScopus5WoS4OpenAlex7İncele - MakaleYalnız künye2023Scopus SJRQ2Contribution of Mechanical Activation for Obtaining Potassium Chloride from Microcline
Alyosif, Bahaa; Uysal, Turan; Aydemir, Muhammet Kürşat; Erdemoğlu, Murat
The effect of intensive milling on the conversion of microcline (KAlSi3O8) to potassium chloride (KCl) occurred during the chlorination roasting process for artificial KCl production was investigated. A feldspar ore with 10.89% K2O grade and containing microcline was dry milled by a planetary ball mill for mechanical activation. Milled ore mixed with calcium chloride was roasted at temperatures between 500 and 1000 °C to get the chlorination roasting process. The product was then leached in water to dissolve KCl occurring during the roasting, which will be precipitated from the pregnant leach solution by evaporation. Results showed that potassium recovery from the unmilled ore increased rapidly up to 800 °C, and dramatically decreased at higher temperatures due to the removal of KCl from the furnace by means of evaporation. A potassium recovery of 31.95% was achieved by the unmilled ore, whereas it was 88.43% when 15 min milled ore was roasted at 750 °C. It was concluded that intensive milling caused mechanical activation of microcline to reduce the roasting temperature of the chlorination roasting process.
AtıfScopus12WoS11OpenAlex10İncele - MakaleYalnız künye2023Scopus SJRQ2Detection of hateful twitter users with graph convolutional network model
Utku, Anıl; Can, Umit; Aslan, Serpil
Today, hate speech is widespread and persistent in various forms on social networking platforms, targeting different minority groups. These attacks can be carried out using various factors such as racial, religious, gender, and physical disability, etc. Considering the number of people and their interactions, social networks are the most important channels through which these discourses spread. The social network structure is considered a set of nodes and edges and is very suitable for the graph structure. The multidimensional structure of social networks carries social network data from Euclidean space to non-Euclidean space. In non-Euclidean space, the graph structure is used to represent data effectively. In this respect, solving the hate speech problem with graph-based methods in a complex dimensional space can produce more impressive results. In this study, a powerful method based on the Graph Convolutional Network (GCN) model, which is rarely used in this field, was proposed for the detection of hateful Twitter users in social networks. Well-known machine learning methods were used to measure the performance of this method. According to the results obtained, the proposed GCN model gave the most successful result.
AtıfScopus15WoS10OpenAlex16İncele - MakaleYalnız künye2023Scopus SJRQ2Engineering Properties of Geopolymer Mortars Containing Industrial Steel Shavings
Gülmez, Nihan; Koçkal, Niyazi Uğur
The purpose of using waste materials is to prevent the unnecessary use of resources and to reduce the amount of waste. Geopolymer, developed as an alternative to cementitious materials, prevents the depletion of natural resources and saves a large amount of energy. This paper presents the effect of waste steel shavings on the improvement of physical and mechanical properties of geopolymer mortars. For this purpose, geopolymer mortars were produced by using two binder types [slag (BFSb) and silica fume] as well as steel shavings in five different replacement percentages (0%, 2.5%, 5%, 7.5% and 10%) by volume instead of aggregate. A series of experiments on geopolymer mortars were carried out to determine properties such as bulk density, water absorption, apparent porosity, sorptivity coefficient, splitting tensile strength, flexural strength and compressive strength. Results showed that steel shavings recovered from metal processing and forming sector were highly effective at improving engineering properties of geopolymer mortars. Furthermore, although replacement of 20% by volume of BFSb with silica fume improved properties of geopolymer mortar, it was observed that the use of silica fume at higher ratios reduced mechanical properties by increasing porosity and sorptivity of BFSb-based geopolymer mortars.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ2Seasonal monitoring of microbial activity using conventional approaches in a full-scale urban biological wastewater treatment plant
Demirbilek, Deniz; İpek, Ubeyde; Yetis, Ulku
Activated sludge processes contain various groups of microorganisms with different metabolic properties, which are responsible for contaminants removal. Therefore, it is important to elucidate the general structure and functional properties of biomass in activated sludge processes. For this purpose, a full-scale domestic biological wastewater treatment plant in Tunceli (Turkey), Tunceli WWTP (wastewater treatment plant), was monitored to observe seasonal variations in process performance and biomass properties for a year. It was observed that nitrifying bacteria developed abundantly in the rainy and cool spring season as they were suppressed in summer because their large losses took place due to an environment containing high alkalinity values. In September, aerobic heterotrophic, nitrify, denitrify, and anaerobic activities increased. It can be said that the biomass contained young and mature microorganism in this environment in which the sludge volume index (SVI) value increased to 196 mL/g. As a result of the improvement in the structural and functional properties of biomass, the nitrogen removal efficiency reached 99%. Throughout the whole study, the structural improvement observed in biomass was reflected in its removal activity. The amount of biomass and removal activity decreased with the abundance of organic matter in the influent at the period in which biomass was closer to being categorized in the aged sludge class. The results showed that as the lowest mixed liquid suspended solids (MLSS) and mixed liquid volatile suspended solids (MLVSS) values of the year were 530 and 400 mg/L, respectively, in November 2017, MLSS and MLVSS values reached the highest amount (1700 and 1400 mg/L, respectively) in December 2017 when aerobic heterotrophic activity accelerated with a decrease in organic matter level.
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