Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bulut, Hasan(53)
- Baskonus, Haci Mehmet(52)
- Alataş, Mevlüt(39)
- Gul, Muhammet(39)
- Serdar, Osman(38)
- Güler, Ömer(37)
- Akkurt, Nevzat(31)
- Benzer, Fulya(30)
- Sulaiman, Tukur Abdulkadir(29)
- Yucesan, Melih(29)
- Zengin, Gokhan(29)
- Kocabaş, Mehmet(28)
- Topal, Murat(26)
- Batan, Nevzat(25)
- Kök, Mediha(25)
- Ezer, Tülay(24)
- Paksoy, Mehmet Yavuz(24)
- Yildirim, Ozal(23)
- Tekin, H.O.(22)
- Utku, Anıl(22)
- ALMisned, Ghada(21)
- Ince, Muharrem(21)
- Öbek, Erdal(21)
- Erten, Fusun(20)
- Aslan, Naim(19)
- Celik, Erkan(19)
- Yildirim, Numan(19)
- Cakilcioglu, Ugur(18)
- Dal, Murat(18)
- Dal, Nursel Alp(18)
- Sahin, Kazim(18)
- Özkaynak, Fatih(18)
- Aslan, Alper(17)
- Erata, Hüseyin(17)
- Orhan, Cemal(17)
- Ergen, Burhan(16)
- Tanyol, Mehtap(16)
- Demir, Yakup(15)
- Etli, Serkan(15)
- Işık, Erdem(15)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ2Investigation on application of plate-tube evaporative condensating technology for data centres in the northwest of China
Wu, Xueyuan; Shao, Shuangquan; Akkurt, Nevzat
The rapid development of data center leads to a rapid increase in energy consumption. In this paper, the plate and tube evaporative condenser is proposed for the water-cooled chiller and the data center cooling system to improve the energy efficiency in hot and dry summer and avoid icing in cold winter. The chiller can operate in the wet mode for compressor refrigeration and the dry mode for free cooling with the coefficient of performance (COP) of 5.2 in wet mode and up to 33.3 in dry mode. Furthermore, the system is applied in a data center in Ulumiqi, which is located in the dry and cold region and its ambient air temperature can vary from −32 °C to 45 °C throughout the year. The actual operation results show that the power usage effectiveness (PUE) value of the whole data centre is 1.349 in June, 1.229 in December, and 1.320 as the annual average, which is stable and efficient for five consecutive years. These results ensure the proposed system is an important technical solution for energy saving and emission reduction in data centres in cold regions.
AtıfScopus9WoS5OpenAlex8
İncele - MakaleAçık Erişim2023Scopus SJRQ2Stress analysis of the contact problem in a functionally graded layer loaded with a distributed load and two rigid circular punches resting on an elastic two quarter planes
Kaya, Fatih; Polat, Alper
In this study, the solution of the contact problem in a functionally graded (FG) layer resting on elastic two quarter planes was done using the finite element method (FEM). The contact problem consists of two rigid circular punches loaded FG and two elastic quarter planes. P and Q loads are transmitted to the FG layer by two rigid circular punches. All surfaces in the problem were considered as frictionless and the weight effect is also taken into account. The two-dimensional model of the contact problem was created with the ANSYS package program based on FEM and the stress analyzes were performed. All operations of quarter planes and circular punches are done with standard ANSYS menus. However, defining the material properties of the FG layer and dividing into meshes in finite elements cannot be done with standard menus. For this reason, a special macro was added to the program in order to define the material properties of the FG layer and to perform the mesh division, and the necessary parameters were applied to the layer by this macro. In the study, the effects of external load, stiffness parameter (βh), density parameter (γh) and contact stresses of distributed load change, normal stresses, and stresses along the depth were investigated.
AtıfScopus6WoS6OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ1Physical-Mechanical and Electrical Resistivity Properties of Cementitious Mortars Containing Fe3O4-MWCNTs Nanocomposite
Selen, Veyis; Guler, Omer; Nodehi, Mehrab; Sarı, Ahmet; Yaras, Ali; Gencel, Osman; Gholampour, Aliakbar; Ozbakkaloglu, Togay
Recent growth in materials science and engineering technologies has pushed the construction industry to engage in new applications, such as the manufacturing of smart and electrically conductive products. Such novel uses of conductive construction materials would potentially allow their use in conjunction with various fields, such as those referred to as “Industry 4.0.” The following study uses iron oxide (Fe3O4)-multi-walled carbon nanotubes (MWCNTs) nanocomposites synthesized by chemical vapor deposition (CVD) and incorporated into the cementitious mortars as a substitute for sand at 1, 2, and 3% ratios to enhance the electrical conductivity. Results reveal that the electrical resistivity of cementitious composites decreases (due to the increase in electrical conductivity) from 208.3 to 61.6 Ω·m with both the Fe3O4-MWCNTs nanocomposites ratio and the increasing voltage. The lowest compressive strengths at 7 and 28 days are 12.6 and 17.4 MPa for specimens with 3% Fe3O4-MWCNTs and meet the standards that comply with most applications. On the other hand, the highest porosity was reached at 26.8% with a Fe3O4-MWCNTs rate of 3%. This increase in porosity caused a decrease in both the dry unit weight and ultrasonic pulse velocity (from 5156 to 4361 m/s). Further, it is found that the incorporation of Fe3O4-MWCNT nanocomposites can have a negative effect on the hardening process of mortars, leading to localized air cavities and an inhomogeneous development of cementing products. Nonetheless, the improvement of the electrical conductivity of the samples without significantly compromising their physico-mechanical properties will allow their use in various fields, such as deicing applications with low-voltage electric current.
AtıfScopus7OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ1A novel radial basis Bayesian regularization deep neural network for the Maxwell nanofluid applied on the Buongiorno model
Sabir, Zulqurnain; Akkurt, Nevzat; Ben Said, Salem
The aim of this work is to provide the numerical solutions of the fluid model by using the stochastic computing paradigms. The linear/exponential stretching sheets on magneto-rotating flow based on the Maxwell nanofluid have been provided using the Buongiorno model with the impacts of uneven heat source/sink, varying thermal conductivity and reactive species. The solutions of this transformed ordinary differential exponential stretching sheet model have been presented using a novel ‘radial basis’ (RB) activation function together with the Bayesian regularization deep neural network (BRDNN), i.e., RB-BRDNN. The deep neural network is presented into two hidden layers, while thirteen and twenty-five numbers of neurons have been used in the first and second layer. A reference dataset is proposed using the Runge-Kutta scheme for the model. The correctness of the stochastic RB-BRDNN procedure is examined through the comparison of proposed and database results, whereas minimal absolute error values provide the accuracy of the scheme. The reliability and competence of the computing RB-BRDNN solver is authenticated using the state transitions, correlation, regression, and error histograms.
AtıfScopus33WoS30OpenAlex36İncele - MakaleAçık Erişim2023Scopus SJRQ2Extracting low dimensional representations from large size whole slide images using deep convolutional autoencoders
Çelik, Yusuf; Karabatak, Murat
Background and objective: Artificial intelligence-based analysis of medical images has recently become a trendy field of study. The most significant effect on these systems to produce reliable and high-performance results is the amount of accessed data. Although whole-slide images (WSI), one of the current imaging techniques used in histopathology, storage costs are very expensive. Therefore, low-dimensional visuals representing of WSIs is an essential field of study. Methods: In this study, deep auto-encoder-based models are designed to create low dimensional representations for WSI. The size reduction was performed for the input images in different sizes, at the ratios of 1: 3, 1: 6, and 1: 12, respectively. Results: Similarity index measure values were obtained as high as 0.957 and 0.938, respectively, using 128 × 128 × 3 dimensional patches in the size reduction process of 1: 3 and 1:12 on test WSI. Conclusion: The proposed model has a structure that can be applied in compression of WSIs and secure data transfer. By using these representations, both storage costs and the high-level hardware costs required by deep learning algorithms can be significantly reduced.
AtıfScopus3WoS2OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ3Investigation of the geometry effect on air-demand ratio in conduits with a sluice gate
Aydin, Alp Bugra; Baylar, Ahmet; Ozkan, Fahri; Tuna, Muhammed Cihat; Ozturk, Mualla
Gated conduits involve high-velocity air-water flow. When studies on gated conduits are examined, it is determined that the air-demand ratio changes according to the hydraulic and geometric parameters. However, no study has investigated the effect of the cross-sectional geometry of high-head conduits with a sluice gate on the air-demand ratio. In this study, the effect of conduit cross-sectional geometry on the air-demand ratio is examined. Results indicate that a conduit's cross-sectional geometry has an important effect on the air-demand ratio, especially at 10% and 15% gate opening rates. It is seen that the effect of the conduit geometry on the air-demand ratio decreases at 20%, and for greater gate opening rates. Moreover, a formula for estimated the air-demand ratio is presented, relating the air-demand ratio to the gate opening rate, Froude number, hydraulic radius and conduit length.
AtıfScopus5WoS6OpenAlex4İncele - 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 - MakaleAçık Erişim2023Scopus SJRQ1A Multi-Input Convolutional Neural Networks Model for Earthquake Precursor Detection Based on Ionospheric Total Electron Content
Uyanık, Hakan; Şentürk, Erman; Akpınar, Muhammed Halil; Ozcelik, Salih T. A.; Kokum, Mehmet; Freeshah, Mohamed; Sengur, Abdulkadir
Earthquakes occur all around the world, causing varying degrees of damage and destruction. Earthquakes are by their very nature a sudden phenomenon and predicting them with a precise time range is difficult. Some phenomena may be indicators of physical conditions favorable for large earthquakes (e.g., the ionospheric Total Electron Content (TEC)). The TEC is an important parameter used to detect pre-earthquake changes by measuring ionospheric disturbances and space weather indices, such as the global geomagnetic index (Kp), the storm duration distribution (Dst), the sunspot number (R), the geomagnetic storm index (Ap-index), the solar wind speed (Vsw), and the solar activity index (F10.7), have also been used to detect pre-earthquake ionospheric changes. In this study, the feasibility of the 6th-day earthquake prediction by the deep neural network technique using the previous five consecutive days is investigated. For this purpose, a two-staged approach is developed. In the first stage, various preprocessing steps, namely TEC signal improvement and time-frequency representation-based TEC image construction, are performed. In the second stage, a multi-input convolutional neural network (CNN) model is designed and trained in an end-to-end fashion. This multi-input CNN model has a total of six inputs, and five of the inputs are designed as 2D and the sixth is a 1D vector. The 2D inputs to the multi-input CNN model are TEC images and the vector input is concatenated space weather indices. The network branches with the 2D inputs contain convolution, batch normalization, and Rectified Linear Unit (ReLU) activation layers, and the branch with the 1D input contains a ReLU activation layer. The ReLU activation outputs of all the branches are flattened and then concatenated. And the classification is performed via fully connected, softmax, and classification layers, respectively. In the experimental work, earthquakes with a magnitude of Mw5.0 and above that occurred in Turkey between 2012 and 2019 are used as the dataset. The TEC data were recorded by the Turkey National Permanent GNSS Network-Active (TNPGN-Active) Global Navigation Satellite System (GNSS) stations. The TEC data five days before the earthquake were marked as “precursor days” and the TEC data five days after the earthquake were marked as “normal days”. In total, 75% of the dataset is used to train the proposed method and 25% of the dataset is used for testing. The classification accuracy, sensitivity, specificity, and F1-score values are obtained for performance evaluations. The results are promising, and an 89.31% classification accuracy is obtained.
AtıfScopus27OpenAlex19İncele - MakaleAçık Erişim2023Scopus SJRQ1Greening Industrially Applied Toxic Cadmium Plating with γ-Ni2Zn11 Alloy in Deep Eutectic Solvents: Promising Electroplating Efficiency and Chemical Corrosion Resistance
Cihangir, Salih
Cadmium is an industrially applied plating metal used in aerospace applications, but electrodeposition of cadmium is toxic, and current production method will soon be banned. Therefore, electrodeposition of alternative alloys in environmentally friendly solutions is an attractive research area. An additive-free, nonaqueous, deep eutectic solvent (DES) containing Ni and Zn halide salts is developed in a greener environmental method. Gamma-phase nanocrystalline Ni2Zn11 is coated onto hot-rolled mild steel via pulse reverse current (PRC) in the developed nonaqueous solvent. The employed DES’ relatively low viscosity and sufficient conductivity enable the simultaneous reduction of Ni2+ and Zn2+ cations on microelectrode. Electrochemical quartz crystal microbalance (eQCM) analysis proves the absence of the commonly reported problem of electrode blocking during electrodeposition, revealing an efficiency of 86.07%. Appropriate PRC parameters are applied for scaled macroelectrode deposition. The plating profile exhibits 20 μm-thick alloy deposition without cracks around 3 h. Scanning electron microscopy–electron-dispersive spectroscopy and X-ray diffraction analyses reveal that 15.5 wt% Ni is in the nanograin phase, and all crystal planes belong to the γ-Ni2Zn11 phase, which is needed as an alternative to cadmium plating. Hardness and corrosion tests performed on the γ-Ni2Zn11 coating reveal better hardness and corrosion resistance with supporting morphological evidence.
AtıfScopus14WoS13OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ1Investigation of surface morphology, optical properties and the gamma radiation effect on selenium coated glass substrate containing rare earth oxide
Taşgin, Yahya; Kanca, Muhammed Sait; Kök, Mediha
In this study, in order to add different properties and functions to inorganic amorphous glasses, the applicability and effects of the thin film coating produced by thermal evaporation method were examined by metallographically imaging the effects of 3%–5% CeO2 and Tm2O3 rare earth elements (REE) oxide added to selenium to change the morphology of the glass surface. As a result of the study, it has been proved that CeO 2 and Tm2O3 added to selenium can be coated by thermal evaporation method with AFM images taken from the glass surface and metallographic analyses (SEM, EDX, Mapping). The lowest roughness value was observed in 95Se–5CeO2 coating glass substrate. In all coatings, selenium, which is the main sample, was found to be active, and XRD measurements showed that the thin films were formed by agglomeration on the (101) plane. According to UV-VIS measurements, the lowest optical band energy range was observed in the 95Se–5CeO2 coating.
AtıfScopus11WoS10OpenAlex12İncele - MakaleAçık Erişim2023Scopus SJRQ2Fabrication of hydroxyapatite-based nano-gold and nano-silver-doped bioceramic bone grafts: Enhanced mechanostructure, cell viability, and nuclear abnormality properties
Demirel, M.; Aslan, N.; Aksakal, B.; Arslan, M.E.
In this study, nano-gold (nAu) and nano-silver (nAg) were doped at the molar ratios of Molar5–Molar30 to the Hydroxyapatite (HAp)-based bioceramic bone graft synthesized by the sol–gel method. The effects of nAu and nAg on structural, mechanical, cell viability, and nuclear abnormality of the synthesized bioceramic grafts were evaluated. The chemical and morphological properties of the bone grafts after production were examined through XRD and SEM–EDX analyses and mechanical tests. To determine the biocompatibility of the bone grafts, cell viability tests were performed using human fibroblast cells. In the cytotoxicity analyses, only HAp and HAp-nAu5 grafts did not show toxicological properties at any concentration, while HAp-nAg5 among the nAg-containing grafts gave the best results at the 200–100 μg/mL concentrations and showed significant cytotoxicity in human fibroblast cells. The other nAu-containing grafts showed toxicological properties in the concentration range of 200–50 μg/mL and nAg-containing grafts in the concentration range of 200–100 μg/mL against the negative control. The micronucleus (MN) analyses showed that the lowest total MN and L (lobbed) amounts, while the lowest total N (notched) amount, was obtained from the only HAp graft. It was found that the nAg-doped bone grafts gave higher total MN, L, and N amounts compared to the nAu-doped bone grafts. Furthermore, while the mean nuclear abnormality (NA) values of all grafts gave close results, the highest values were again obtained from the nAg-doped bone grafts.
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İncele - MakaleAçık Erişim2023Scopus SJRQ3WEAR AND ADHESION PROPERTIES OF MULTILAYER Ti/TiN, (/TiC)/ TiCN/ TaN THIN FILMS DEPOSITED ON Ti13Nb13Zr ALLOY BY CLOSED FIELD UNBALANCED MAGNETRON SPUTTERING
Aslan, Ali Kemal; Bahçe, Erkan
Ti13Nb13Zr alloy stands out as an alternative to Ti6Al4V alloy for orthopaedic joint implant applications due to its low modulus of elasticity, high mechanical properties, high corrosion resistance, high biocompatibility and low modulus of elasticity, as well as con-taining no cytotoxic elements. In this study, Ti13Nb13Zr alloy was coated with TiN/TiC/TiCN/TaN multilayer thin films by pulsed-dc CFBUMS method to increase wear resistance and improve surface properties. Characterization of the deposited films were con-ducted by XRD, SEM, AFM, pin-on-disk, progressive scratch experiments. As a result, it is observed that all the coatings enhanced the tribological properties of the Ti13Nb13Zr alloy surface. The 20-layer TiN/TiC/TiCN/TaN multilayer coatings gave the best results for wear resistance and adhesion properties. Enhancing the interlayer number resulted in increased wear and adhesion resistance. In addition, it was determined that using TiC instead of TiN in the interlayers gave higher results regarding adhesion, wear, and mechanical properties.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ1Orbitrap Mass Spectrometry-Based Profiling of Secondary Metabolites in Two Unexplored Eminium Species and Bioactivity Potential
Babacan, Ebru Yuce; Zheleva-Dimitrova, Dimitrina; Gevrenova, Reneta; Bouyahya, Abdelhakim; Balos, Mehmet Maruf; Cakilcioglu, Ugur; Sinan, Kouadio Ibrahime; Zengin, Gokhan
The study aimed at the metabolite profiling and evaluation of antioxidant and enzyme inhibitory properties of methanol extracts from flowers, leaves, and tubers of unexplored Eminium intortum (Banks & Sol.) Kuntze and E. spiculatum (Blume) Schott (Araceae). A total of 83 metabolites, including 19 phenolic acids, 46 flavonoids, 11 amino, and 7 fatty acids were identified by UHPLC-HRMS in the studied extracts for the first time. E. intortum flower and leaf extracts had the highest total phenolic and flavonoid contents (50.82 ± 0.71 mg GAE/g and 65.08 ± 0.38 RE/g, respectively). Significant radical scavenging activity (32.20 ± 1.26 and 54.34 ± 0.53 mg TE/g for DPPH and ABTS) and reducing power (88.27 ± 1.49 and 33.13 ± 0.68 mg TE/g for CUPRAC and FRAP) were observed in leaf extracts. E. intortum flowers showed the maximum anticholinesterase activity (2.72 ± 0.03 mg GALAE/g). E. spiculatum leaves and tubers exhibited the highest inhibition towards α-glucosidase (0.99 ± 0.02 ACAE/g) and tirosinase (50.73 ± 2.29 mg KAE/g), respectively. A multivariate analysis revealed that O-hydroxycinnamoylglycosyl-C-flavonoid glycosides mostly accounted for the discrimination of both species. Thus, E. intortum and E. spiculatum can be considered as potential candidates for designing functional ingredients in the pharmaceutical and nutraceutical industries.
AtıfScopus15OpenAlex11İncele - MakaleAçık Erişim2023Phycoremediation of Thallium Toxic Metal Present in Gallery Water of an Abandoned Mine Area by Algae Cladophora fracta
Topal, Murat; Arslan Topal, E. Işıl; Öbek, Erdal
In this study, phycoremediation of thallium toxic metal present in galery water of an abandoned mine area was investigated by using Cladophora fracta. Within the scope of the study, a reactor containing Cladophora fracta was used and it was determined whether the Cladophora fracta accumulated thallium depending on time. Additionally, the bioconcentration factor was calculated. According to research findings; the accumulations of thallium by Cladophora fracta, compared with uncontaminated alga, were 225% at 5 min, 450% at 10 min, 550% at 20 min, 575% at 40 min, 700% at 60 min, and 900% at 120 min, respectively. BCF values were between 1000-5000. This indicated that Cladophora fracta had bioaccumulation potential. As a result, this research carried out in mining area has documented the phycoremediation of thallium in gallery water of an abandoned mine area.
- MakaleAçık Erişim2023Scopus SJRQ3Rotor Field-Oriented Control of Doubly Fed Induction Generator in Wind Energy Conversion System
Omac, Zeki; Erdem, Irfan
In this study, robust and high-performance vector control of a rotor side converter (RSC) was performed for stability and efficient operation doubly fed induction generator (DFIG) based on the variable speed wind turbine (VSWT). The mathematical model of the DFIG is simulated in the computer. Amplitude and frequency of the voltage in the DFIG were controlled for different values of load and variable speeds. In the experimental study, a DFIG-based wind turbine system was set up in the laboratory. The field position of the stator was detected from stator voltages by a phase-locked loop (PLL) circuit. The rotor position was measured with an incremental encoder connected to the rotor shaft of the DFIG. The angular position of the slip was calculated by the difference between the rotor and the stator field positions. The frequency and amplitude of rotor currents were determined with the angular position of slip. To generate output voltages of converter feeding rotor windings, the space vector pulse width modulation (SVPWM) technique was used. In the experimental study, the RSC was controlled with the DS1103 board. The prepared experiment set was tested at different operating speeds.
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İncele - MakaleAçık Erişim2023Scopus SJRQ1PatchResNet: Multiple Patch Division–Based Deep Feature Fusion Framework for Brain Tumor Classification Using MRI Images
Muezzinoglu, Taha; Baygin, Nursena; Tuncer, Ilknur; Barua, Prabal Datta; Baygin, Mehmet; Dogan, Sengul; Tuncer, Turker; Palmer, Elizabeth Emma; Cheong, Kang Hao; Acharya, U. Rajendra
Modern computer vision algorithms are based on convolutional neural networks (CNNs), and both end-to-end learning and transfer learning modes have been used with CNN for image classification. Thus, automated brain tumor classification models have been proposed by deploying CNNs to help medical professionals. Our primary objective is to increase the classification performance using CNN. Therefore, a patch-based deep feature engineering model has been proposed in this work. Nowadays, patch division techniques have been used to attain high classification performance, and variable-sized patches have achieved good results. In this work, we have used three types of patches of different sizes (32 × 32, 56 × 56, 112 × 112). Six feature vectors have been obtained using these patches and two layers of the pretrained ResNet50 (global average pooling and fully connected layers). In the feature selection phase, three selectors—neighborhood component analysis (NCA), Chi2, and ReliefF—have been used, and 18 final feature vectors have been obtained. By deploying k nearest neighbors (kNN), 18 results have been calculated. Iterative hard majority voting (IHMV) has been applied to compute the general classification accuracy of this framework. This model uses different patches, feature extractors (two layers of the ResNet50 have been utilized as feature extractors), and selectors, making this a framework that we have named PatchResNet. A public brain image dataset containing four classes (glioblastoma multiforme (GBM), meningioma, pituitary tumor, healthy) has been used to develop the proposed PatchResNet model. Our proposed PatchResNet attained 98.10% classification accuracy using the public brain tumor image dataset. The developed PatchResNet model obtained high classification accuracy and has the advantage of being a self-organized framework. Therefore, the proposed method can choose the best result validation prediction vectors and achieve high image classification performance.
AtıfScopus103OpenAlex101İncele - MakaleAçık Erişim2023Scopus SJRQ2The Epiphytic Bryophyte Vegetation of Buxus sempervirens L. forests in the Fırtına Valley (Rize, Turkey); [Végétation de bryophytes épiphytes des forêts de Buxus sempervirens L. dans la vallée de Fırtına (Rize, Turquie).]
Alataş, Mevlüt; Ezer, Tülay; Erata, Hüseyin; Batan, Nevzat; Ursavaş, Serhat
The Fırtına Valley forests are of the 100 forests in the world whose conservation is a priority due to the natural old forests they have. In this study, the epiphytic bryophyte vegetation of the Buxus sempervirens L. forests located in the Fırtına Valley (Rize, Northern Turkey), which is one of the nine hotspots in Turkey and Turkey’s only boxwood forest, was investigated. The relevés taken from living tree trunks in 2020 were analyzed according to the Braun-Blanquet methodology, and ordinated and classified using the Detrended Correspondence Analysis (DECORANA) and the Two-Way Indicator Species Analysis (TWINSPAN). As a result of the analyses, Exsertotheco crispae-Allenielletum besseri ass. nov. subass. typicum and leucodontetosum sciuroidis subass. nov., and Alleniello besseri-Palamocladietum euchloronis ass. nov. were described and characterized. All syntaxa were presented by analyzing them in terms of their ecological and floristic classifications.
AtıfScopus2OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ4Single and combined effects of dimethoate and malathion on oxidative stress biomarkers in the non-target freshwater mussel Dreissena polymorpha
Serdar, Osman; Yildirim, Numan; Yildirim, Nuran Cikcikoglu
This study evaluates the single and combined effects of dimethoate (DI) and malathion (MA) on oxidative stress biomarkers in the freshwater mussel Dreissena polymorpha, estimating the potential harm of these pesticides on aquatic ecosystems. Superoxide dismutase (SOD) and catalase (CAT) activities, and glutathione (GSH) and lipid peroxidation (TBARS) levels were determined in D. polymorpha exposed to sublethal concentrations of DI, MA and a combination of the two during 24 and 96 h periods. The results showed that the GSH levels were decreased but the TBARS levels were increased in all the exposure groups after 24 and 96 h compared to the control. It was observed that SOD activity decreased but CAT activity increased in all the DI exposure groups after 24 h compared to the control. At the end of 96 hours, it was observed that CAT and SOD activities increased again in some exposure groups compared to the control. Exposure time also had an effect on biomarkers in different levels. According to the results, the cytotoxicity of DI and MA combination depended on their concentrations. DI or/ and MA, in sub-lethal concentrations, induced oxidative damages in D. polymorpha. Combined exposure of the pesticides can alter their toxicity and may be evidence of increased toxicity and oxidative stress.
AtıfScopus3WoS3OpenAlex2İncele - DüzeltmeAçık Erişim2023Correction to: A new approach based on convolutional neural network and feature selection for recognizing vehicle types(Iran Journal of Computer Science, 10.1007/s42044-022-00125-6)
Doğan, Gürkan; Ergen, Burhan
The sentence beginning 'Bu nedenle bu …' in this article should have read 'Therefore, in this study, a combination of OMobileNetv1, OMobileNetv2, ONASNetMobile CNN methods for feature extraction, LSVC method for feature selection and SVM method for classification is proposed.' The original article has been corrected.
- MakaleAçık Erişim2023Scopus SJRQ1Modeling and numerical simulation of non-Newtonian arterial blood flow for mild to severe stenosis
Nadeem, Sohail; Ali, Shahbaz; Akkurt, Nevzat; Ben Hamida, Mohamed Bechir; Almutairi, Shahah; Ali Ghazwani, Hassan; Eldin, Sayed M; Khan, Zareen A.; Al-Shafay, A.S.
The fundamental cause of coronary heart disease is thought to be atherosclerosis. Blood flow in arteries under plaque formation is widely studied using both experimental and theoretical methods in literature. This paper presents a comprehensive study on the mathematical modelling and numerical simulation of non-Newtonian blood flow in an idealized stenosed artery. Non-Newtonian behavior of blood flow is assumed by Casson and Quemada fluid models. An analysis is performed for four forms of stenosis, 50%, 60%, 70%, and 80%, which are defined by a narrowing of the artery's diameter. The mathematical model for non-Newtonian fluid transport is presented in the form of highly nonlinear coupled partial differential equations. A finite-volume approach is used to solve the system of equations numerically. The solutions are obtained using a hybrid mesh with hexahedron and tetrahedron control volumes. Numerical solutions are validated first with experimental results from the literature for a Newtonian fluid, and then the results are extended to non-Newtonian fluid models. It can be observed that the non-Newtonian nature of the fluid model influences flow dynamics and is a significant aspect to consider for arteries with small diameter. The velocity and pressure drop rise as the degree of stenosis develops. Wall shear is substantially larger in stenotic passages and severity of stenosis is directly related with this increasing behavior.
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