Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(64)
- Merdan, Mehmet(47)
- Baltaci, Cemalettin(35)
- Kulakaç, Nurşen(28)
- Duran, Celal(27)
- Ozdes, Duygu(24)
- Turan, Ibrahim(24)
- Demir, Selim(23)
- Türkkan, Tuğba(22)
- Bayrakdaroglu, Serdar(21)
- Topal, Fevzi(21)
- Öztürk, Serkan(21)
- Ürkek, Bayram(21)
- Gücer, Mehmet Ali(20)
- Akar, Zeynep(19)
- Kaygusuz, Abdullah(19)
- Topal, Meryem(19)
- Anaç, Halil(18)
- Aydin, Aydanur(18)
- Batan, Nevzat(18)
- Erata, Hüseyin(18)
- Tuncer, Metin(18)
- Akyürek, Suat(17)
- Baltacı, Cemalettin(17)
- Karimullah, Suud Sarim(17)
- Acet, Tuba(16)
- Akar, Bülent(16)
- Ashyralyyev, Charyyar(16)
- Düzgün, Azer Özad(16)
- Hintistan, Sevilay(16)
- Yılmaz, Coşkun(16)
- Aliyazicioglu, Yuksel(15)
- Kaya, Hacer(15)
- Kurnaz, Muammer(15)
- Kurt, Kemal(15)
- Ozden, Talat(15)
- Yilmaz, Coskun(15)
- Yuksel, Ferhat(15)
- Yücel, Cem(15)
- Öz, Mehmet(15)
Yayınlar
- MakaleAçık Erişim2022Scopus SJRQ2Innovative polygon trend analyses with star graph for rainfall and temperature data in agricultural regions of Turkey
Acar, Emine; Kankal, Murat; Akçay, Fatma; Şan, Murat
Agriculture is affected by climate change, such as extreme increases or decreases rainfall and temperature patterns. It is possible to research that effect by using trend analysis methodologies. This paper investigates trends of monthly total rainfall and mean temperature data of nine selected stations from agricultural regions of Turkey between 1969 and 2020. To the end, the classical Mann–Kendall, Innovative Trend Significance Test (ITST), and Innovative Polygon Trend Analysis (IPTA) with Star Graph methods providing the opportunity to examine seasonal behavior were used for trend analysis. The analysis reveals that about 96% of all monthly rainfall in the Mann-Kendall test has no trend. However, nearly all stations tend to decrease (increase) in November (September) in both innovative approaches. For temperature, it is seen that increasing trend or no trend dominated in general. There were increasing trends in the innovative approaches throughout the year except for April. Temperatures have increased significantly throughout the year in all regions over the last decades. With the help of IPTA, it was also concluded that the seasonal internal variability of rainfall over the entire time and in the last 30 years is quite complex and persists in all agricultural regions. The results show that irregular changes in rainfall and rising temperatures in all stations negatively affected crop yield and/or required more irrigation. In addition, according to the results obtained by comparing trend methods, innovative approaches are very insistent on determining of trend and provide additional information through a visual review of trend behaviors.
AtıfScopus22WoS22OpenAlex26
İncele - MakaleAçık Erişim2022Scopus SJRQ1Evaluation of the in vitro antioxidant, antidiabetic and anticholinergic properties of rosmarinic acid from rosemary (Rosmarinus officinalis L.)
Topal, Meryem; Gulcin, İlhami
In this study, antidiabetic, anticholinergic, and antioxidant abilities of rosmarinic acid were evaluated and compared to standards. To determine its antioxidant activity different in vitro bioanalytical methods, including total antioxidant activity (TAA), ABTS•+ scavenging activity, O2•- scavenging activity, DPPH· scavenging activity, DMPD•+ scavenging activity, potassium ferric cyanide reduction ability, cupric ion (Cu2+) reduction capacity, H2O2 scavenging activity, and ferrous ions (Fe2+) binding activities were separately performed. Also, butylated hydroxyanisole (BHA), Trolox, α-tocopherol, and butylated hydroxytoluene (BHT) were used as the reference antioxidants. Rosmarinic acid inhibited the linoleic acid emulsion peroxidation by 89.2% while BHA, BHT, Trolox and α-tocopherol inhibited as 87.3, 97.6, 90.3 and 75.3%, respectively, at the same concentration (30 μg/mL). When these results are evaluated, rosmarinic acid had effective TAA than BHA and α-tocopherol and close to BHT and Trolox. In addition, rosmarinic acid exhibited Kİ values of 9.67 ± 0.81 nM towards acetylcholinesterase (AChE) and 33.56 ± 2.96 nM against α-glycosidase enzymes.
AtıfScopus94WoS81OpenAlex85İncele - MakaleAçık Erişim2022New weyl-type inequalities by multiplicative injective and surjective s-numbers of operators in reflexive banach spaces; [Yansımalı Banach Uzaylarda Operatörlerin Çarpımsal İnjektiv ve Surjektiv s-Sayıları ile Yeni Weyl-Tipi Eşitsizlikleri]
Cona, Lale
In this work, two problems are investigated. In general. Weyl-type inequalities of operators in complex reflexive Banach spaces are discussed. Fir st, w'e obtained the Weyl-type inequalities using arbitrary multiplicative surjective and injective s-numbers that are dual of each other. Second, w'e introduced the Weyl-type inequalities by multiplicative injective and surjective s- numbers under certain conditions for S and S' operators hi complex reflexive Banach space. So. new Weyl-type inequalities are investigated for both dual s-number sequences and dual operators.
- MakaleAçık Erişim2022Scopus SJRQ2Financial Literacy in Micro-Scale Enterprises Operating in Forest Products Sector: Sample of Gumushane, Turkey; [Financijska pismenost u mikropoduzećima sektora prerade drva: provincija Gumushane, Turska]
Top, Yener; Özbek, Adem
Enterprises are one of the main components of the economic system and they are indispensable for maintaining the sustainability of economic activities. The majority of these enterprises are small and medium-sized enterprises (SMEs). Sustainability of SMEs depends on their good financial management. Inadequate financial literacy causes SMEs’ owners to make inaccurate financial decisions. The forest products sector is mostly composed of micro-scale enterprises in which financial problems are common. Therefore, this study aims to reveal the financial literacy status of the owners of micro-scale and wood-processing enterprises. For this purpose, 78 enterprises were selected as study population. Data were collected by applying a structured questionnaire to 43 of these companies by the face-to-face interview method. The structured questionnaire consisted of multiple-choice and open-ended questions and statements prepared on the Five Likert scales. Data were analysed by using the Independent-Sample T-Test, Mann-Whitney U-Test and correlation test. The reliability coefficient of the data was found to be 0.791. Of the enterprises, 58 % produced in the furniture sub-sector and 42 % in the wood products sub-sector. This study provides evidence that there was no statistically significant difference between the knowledge means of economics and financial behaviour of the furniture and wood products sectors. However, the enter-prise owners’ knowledge of financial analysis positively affected their financial literacy and financial behaviour.
AtıfScopus1OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ2Insights into brewed tea waste as a green and low-priced adsorbent for solid-phase extraction of Cd(II) ions: isotherm, kinetic, and artificial neural network approach
Ozdes, Duygu; Tilki, Nida; Seker, Serdal; Duran, Celal
In the present research, brewed tea waste (BTW) was utilized as a green, low-priced, and abundant adsorbent for separation/preconcentration of Cd(II) ions through solid-phase extraction method from water and foods for the first time. BTW was applied as a natural adsorbent, without using any chelating agent to bind Cd(II) ions or any chemical reagent for its modification. A three-layer artificial neural network model using backpropagation algorithm was utilized to explicate a prediction model for the extraction performance of Cd(II) ions by selecting the input parameters as solution pH, quantity of BTW, sample volume, eluent concentration and volume, and equilibrium time for desorption. The preconcentration factor, relative standard deviation, and detection limit were attained as 100, 3.03%, and 0.56 µg L−1, respectively. It was decided that the Langmuir isotherm model is acceptable to characterize the retention of Cd(II) ions on BTW. This result pointed out that the active binding sites on the BTW surface are homogeneously distributed. Adsorption capacity of BTW was achieved as 41.5 mg g−1 which is higher than several expensive and difficult-to-prepare adsorbents. Adsorption kinetics was elucidated by pseudo-second order kinetic model. After confirmed the accuracy of the method with spike/recovery studies, it was employed for Cd(II) determination in water (stream and sea water) and food (eggplant, lettuce, parsley, apple, and apricot) samples with high accuracy. The inferences of the study proved that the BTW offers a magnificent application prospect in the extraction of Cd(II) ions.
AtıfScopus9WoS9OpenAlex9İncele - MakaleAçık Erişim2022Scopus SJRQ2Flaxseed and Cornelian cherry: Development of a functional cookie using response surface methodology
İlyasoğlu, Huri; Arslan Burnaz, Nesibe; Arpa Zemzemoğlu, Tuba Eda
Consumers' demand for healthy foods has been increased. The aim of this study was to develop a functional cookie from wheat flour with flaxseed (FS) and Cornelian cherry (CC). The effects of the levels of FS flour (10–30 g for 100 g composite flour) and CC powder (2–10 g for 100 g composite flour) in the cookie formulation on the cookie properties were investigated by using response surface methodology. The lightness of the cookies was decreased with the addition of the FS and CC. The incorporation of the FS into the formulation enhanced the content of omega-3 fatty acids. Both FS and CC enhanced the total phenolic contents (TPCs) and antioxidant capacity of the cookies. Moreover, they did not have effects on the hardness and overall acceptability. The developed cookie contained FS (23.6 g 100 g−1) and CC (10 g 100 g−1) that provided α-linolenic acid (16.5 g 100 g−1), TPC (340.2 mg GAE 100 g−1), and antioxidant capacity (996.6 μmol TEAC 100 g−1). Our study indicated that the combination of wheat flour with FS with CC can have the potential to enhance the nutritional and functional values of the cookies. Novelty impact statement: The combination of wheat flour with flaxseed and Cornelian cherry in the cookie formulation enhanced the contents of omega-3 fatty acids, total phenolic content, and antioxidant capacity of the cookies. The developed cookie may be an alternative product for consumers who look for healthy bakery products.
AtıfScopus4WoS3OpenAlex2İncele - MakaleAçık Erişim2022Scopus SJRQ1Closing the Loop in Photovoltaic Solar and Wind Power Supply Chains: An investigation in Turkey through Neutrosphopic-DELPHI-based Force Field Analysis and Neutrosphopic-DEMATEL
Erol, Ismail; Peker, Iskender; Turan, İsmet; Benli, Tolga
Since solar panels and wind turbines have limited lifespans, solar photovoltaic energy supply chain (SPvESC) and wind energy supply chain (WESC) in Turkey needs a paradigm shift to improve the efficiency and recyclability of solar panel and wind turbine components. The circular economy (CE) is a viable strategy for reducing the negative effects of linear supply chains in the SPvESC and WESC. However, despite the several drivers of implementing CE in the SPvESC and WESC, there are also barriers to CE initiatives. It is argued that further studies are needed to explore the drivers and challenges for CE adoption in different industries of developing and developed countries. Hence, the goal of this research is to explore the driving and restraining forces for CE adoption in Turkey's SPvESC and WESC through a decision framework that includes Neutrosphopic DELPHI-based Force Field Analysis, Neutrosphopic-DEMATEL, and Nominal Group Technique. The findings of this research suggested that because the total score of restraining forces is higher than that of driving forces in force field analysis, it is critical to investigate the relationships among the restraining forces. Our findings also suggested that nonexistence of effective incentives and regulations proved to be the most prominent restraining force.
AtıfScopus14WoS13OpenAlex16İncele - DüzeltmeAçık Erişim2022Scopus SJRQ3Correction to: The First Measurement for Mass Attenuation Coefficients, Effective Atomic Numbers, and Electron Densities of Y123 and Y358 High-Temperature Superconductors (HTS) for the Energies from 46.6 to 1332 keV (Journal of Superconductivity and Novel Magnetism, (2021), 34, 3, (695-703), 10.1007/s10948-020-05771-0)
Düzgün, İbrahim
The original version of this article contained a mistake. Thus this erratum is presented to fix this error. The section “Funding” should read as follows: This study was funded by the Grant-in-Aid for Gümüşhane University Research Fund (GÜBAP), from the Gümüşhane University (Project Number: 13.F5120.02.1).
- MakaleAçık Erişim2022Conformable Fractional Elzaki Decomposition Method of Conformable Fractional Space-Time Fractional Telegraph Equations
Anaç, Halil
Conformable space-time fractional linear telegraph equations are examined using a new method known as conformable fractional Elzaki decomposition method. The suggested method combines the Adomian decomposition method with the conformable fractional Elzaki transform. It is found that numerical simulations confirm the effectiveness and reliability of the proposed method.
AtıfScopus5OpenAlex9İncele - MakaleAçık Erişim2022Scopus SJRQ1Finite-Time Neuro-Sliding-Mode Controller Design for Quadrotor UAVs Carrying Suspended Payload
Bingöl, Özhan; Güzey, Hacı Mehmet
Due to the quadrotor’s underactuated nature, suspended payload dynamics, parametric uncertainties, and external disturbances, designing a controller for tracking the desired trajectories for a quadrotor that carries a suspended payload is a challenging task. Furthermore, one of the most significant disadvantages of designing a controller for nonlinear systems is the infinite-time convergence to the desired trajectory. In this paper, a finite-time neuro-sliding mode controller (FTNSMC) for a quadrotor with a suspended payload that is subject to parametric uncertainties and external disturbances is designed. By constructing a finite-time sliding mode controller, the quadrotor can follow the reference trajectories in finite time. Furthermore, despite time-varying nonlinear dynamics, parametric uncertainties, and external disturbances, a neural network structure is added to the controller to effectively reduce chattering phenomena caused by high switching gains, and significantly reduce the size of the control signals. Following the completion of the controller design, the system’s stability is demonstrated using the Lyapunov stability criterion. Extensive numerical simulations with various scenarios are run to demonstrate the effectiveness of the proposed controller.
AtıfScopus28WoS22OpenAlex21İncele - MakaleAçık Erişim2022Scopus SJRQ1Innovative approaches to the trend assessment of streamflows in the Eastern Black Sea basin, Turkey
Akçay, Fatma; Kankal, Murat; Şan, Murat
The issue of detection of hydrometeorological trends remains relevant because of the importance of climate change in design, operation, and management studies related to water resources. This study examines the effects of changes in climate and land use on monthly flows (1962–2018) in the Eastern Black Sea basin, Turkey, using innovative trend analysis methods. In this context, innovative polygon trend analysis (IPTA) and innovative trend significance test (ITST) were used to detect the trends and compared with Mann-Kendall test. Only stations with homogeneous data that did not experience non-climatic changes are used in the analysis. IPTA and ITST approaches are much more sensitive than Mann-Kendall in detecting trends. Although the innovative methods are mostly compatible with each other (90%), IPTA presents additional information about trend transitions between successive parts of time series. Results indicate significant decreasing trends in summer months, likely due to diminishing precipitation and effective evaporation.
AtıfScopus48WoS46OpenAlex56İncele - MakaleAçık Erişim2022Scopus SJRQ2A new cryptic species of the Darevskia parvula group from NE Anatolia (Squamata, Lacertidae)
Arribas, Oscar; Candan, Kamil; Kurnaz, Muammer; Kumlutaş, Yusuf; Caynak, Elif Yıldırım; Ilgaz, Çetin
In this study, we re-examine the Darevskia parvula group comprehensively using morphology, osteology and mitochondrial phylogeny, and describe a new endemic species from Turkey: Darevskia tuniyevisp. nov. A total of 257 adult specimens were evaluated for external morphology (scalation and biometry) with univariate (descriptive statistics and ANOVA with post-hoc tests) and multivariate (Discriminant Analysis and ANOSIM) analyses. In parallel, osteological data and molecular analyses using three DNA markers (mitochondrial 16S rRNA and Cyt-b, nuclear Rag-1) were used to complete the description of the new taxon. The molecular phylogenetic analyses indicated that the D. parvula group is composed of three taxa as D. parvula, D. adjarica and D. tuniyevisp. nov., and showed that D. adjarica and D. tuniyevisp. nov. are reciprocal sister taxa. On the other hand, D. adjarica is morphologically very different from other two forms, while D. parvula is hardly distinguishable externally from D. tuniyevisp. nov. Therefore, we can consider that D. parvula and D. tuniyevisp. nov. are cryptic species. These two cryptic species retain their primitive morphology within the group, while D. adjarica has changed, perhaps due to different bioclimatic conditions in its Pleistocene refuge and current area.
AtıfScopus14WoS11OpenAlex11İncele - MakaleAçık Erişim2022Scopus SJRQ3Phytoremediation ability of Helichrysum arenarium plant for Au and Ag: case study at Demirören village (Gümüşhane, Turkey)
Vural, Alaaddin; Safari, Semaneh
It was investigated ability of Helichrysum arenarium plant, in phytoextraction, phytostabilization, and phytoremediation in this study. Soil and plant samples were collected from the Demirören alteration site which has the potential of gold mineralization and analyzed for gold and silver. When the results of the analysis were evaluated, it was determined that the gold and silver contents in the soil did not show compatibility with the gold and silver contents of the plants grown at the same point. It was concluded that the high gold and silver concentrations in the plants are related to the hydrothermal alteration and weathering at the point where the plants grow. For investigation of phytoremediation ability of the plant, translocation factor (TF), bio-concentration factor (BCF), and bioaccumulation factor (BAF) were calculated. The values of TF, BAF, and BCF for Ag are equal 0.33, 0.043, and 0.13 and for Au are equal 2.04, 0.59, and 0.29, respectively. So, obtained data show that Helichrysum arenarium is not appropriate for phytoextraction and phytostabilization of gold and silver in this case, but H. arenarium can be used in phyto-mining and for biogeochemical exploration of gold. Considering that the gold and silver concentrations in the developed soil in the study area are low concentrations, it is predicted that a similar study will yield satisfactory-interesting results when it is made in plants grown on the gold mineralization/enrichment areas.
AtıfScopus9WoS9OpenAlex11İncele - MakaleAçık Erişim2022Scopus SJRQ1Zircon U[sbnd]Pb geochronology and petrology of the tholeiitic gabbro from the Kovanlık (Giresun) area: Constraints for the Late Cretaceous bimodal arc magmatism in the Eastern Pontides Orogenic Belt, NE Turkey
Temizel, İrfan; Arslan, Mehmet; Abdioğlu Yazar, Emel; Aslan, Zafer; Kaygusuz, Abdullah; Baki Eraydın, Tuğba
Mafic intrusions of the Eastern Pontides Orogenic Belt (EPOB) in NE Turkey are found rarely in varying ages, sizes and compositions. Of these, tholeiitic gabbro stocks, namely Kovanlık gabbro, consist of pyroxene gabbro and minor hornblende gabbro with a mainly granular texture. The pyroxene gabbro contains plagioclase, clino- and ortho-pyroxene, olivine, and Fe[sbnd]Ti oxides, whereas the hornblende gabbro includes mainly plagioclase, hornblende, rarely biotite and Fe[sbnd]Ti oxides. The clinopyroxene compositions of the pyroxene gabbro exhibit arc-related tholeiitic magmas. The Kovanlık gabbroic rocks have high U/Yb zircon ratios, implying continental arc-related tectonic settings. Zircon U[sbnd]Pb dating on the Kovanlık gabbro yielded a concordia age of ~92 Ma (Turonian). Petrochemically, the gabbroic rocks have a tholeiitic character and show arc- and MORB-like signatures. The gabbroic rocks show positive Rb, Ba, K, Pb, Sr, Ti and negative Nb, Ce, Nd, Hf, Zr anomalies in N-MORB normalized diagrams. The chondrite-normalized REE plots of the rocks show flat to feeble right-dipping REE patterns (LaN/LuN = 0.94–2.56) with positive Eu anomalies (EuN/Eu* = 1.15–2.14; except for two pyroxene gabbro samples). The gabbroic rocks have 87Sr/86Sr(i) ratios (0.704533 to 0.706265), εNd(i) values (4.04–4.85), 206Pb/204Pb (18.56–18.68) and 207Pb/204Pb (15.61–15.64) ratios. Low Nb/La and Nb/Y ratios, as well as high Sr/Yb and Ba/Rb ratios, indicate that source regions were modified by slab-derived fluids and/or melts. The obtained zircon dating, isotopic and geochemical data, as well as regional geology, revealed that the tholeiitic mafic magma derived from a spinel-lherzolite mantle at a relatively shallow depth, and the Kovanlık gabbro in the EPOB represents one of the first mafic intrusions of Late Cretaceous bimodal arc magmatism related to the roll-back of the northwards subducting Tethys oceanic plate.
AtıfScopus19WoS17OpenAlex20İncele - MakaleAçık Erişim2022Scopus SJRQ1COVID-DSNet: A novel deep convolutional neural network for detection of coronavirus (SARS-CoV-2) cases from CT and Chest X-Ray images
Reis, Hatice Catal; Turk, Veysel
COVID-19 (SARS-CoV-2), which causes acute respiratory syndrome, is a contagious and deadly disease that has devastating effects on society and human life. COVID-19 can cause serious complications, especially in patients with pre-existing chronic health problems such as diabetes, hypertension, lung cancer, weakened immune systems, and the elderly. The most critical step in the fight against COVID-19 is the rapid diagnosis of infected patients. Computed Tomography (CT), chest X-ray (CXR), and RT-PCR diagnostic kits are frequently used to diagnose the disease. However, due to difficulties such as the inadequacy of RT-PCR test kits and false negative (FN) results in the early stages of the disease, the time-consuming examination of medical images obtained from CT and CXR imaging techniques by specialists/doctors, and the increasing workload on specialists, it is challenging to detect COVID-19. Therefore, researchers have suggested searching for new methods in COVID- 19 detection. In analysis studies with CT and CXR radiography images, it was determined that COVID-19-infected patients experienced abnormalities related to COVID-19. The anomalies observed here are the primary motivation for artificial intelligence researchers to develop COVID-19 detection applications with deep convolutional neural networks. Here, convolutional neural network-based deep learning algorithms from artificial intelligence technologies with high discrimination capabilities can be considered as an alternative approach in the disease detection process. This study proposes a deep convolutional neural network, COVID-DSNet, to diagnose typical pneumonia (bacterial, viral) and COVID-19 diseases from CT, CXR, hybrid CT + CXR images. In the multi-classification study with the CT dataset, 97.60 % accuracy and 97.60 % sensitivity values were obtained from the COVID-DSNet model, and 100 %, 96.30 %, and 96.58 % sensitivity values were obtained in the detection of typical, common pneumonia and COVID-19, respectively. The proposed model is an economical, practical deep learning network that data scientists can benefit from and develop. Although it is not a definitive solution in disease diagnosis, it may help experts as it produces successful results in detecting pneumonia and COVID-19.
AtıfScopus36WoS22OpenAlex36
İncele - MakaleAçık Erişim2022Automatic prediction of covid-19 from chest-computed tomography (CT) images using deep learning architectures; [Derin öğrenme mimarilerini kullanarak göğüs BT görüntülerinden otomatik Covid-19 tahmini]
Turk, Veysel; Catal Reis, Hatice; Kaya, Serhat
Machine learning has been actively used in disease detection and segmentation in recent years. For the last few years, the world has been coping with the Coronavirus disease 2019 (COVID-19) pandemic. Chest-computerized tomography (CT) is often a meaningful way to detect and detect patients with possible COVID-19. This study aims to classify COVID-19 and non-COVID-19 chest-CT images using deep learning (DL) algorithms and investigate whether we can achieve successful results in different parameters using four architectures. The study was performed on proved positive COVID-19 CT images, and the datasets were obtained from the GitHub public platform. The study evaluated four different deep learning architectures of VGG16, VGG19, LeNet-5, and MobileNet. The performance evaluations were used with ROC curve, recall, accuracy, F1-score, precision, and Root Mean Square Error (RMSE). MobileNet model showed the best result ; F1 score of 95%, the accuracy of 95%, the precision of 100%, recall of 90%, AUC of 95%, and RMSE of 0.23. On the other hand, VGG 19 model gave the lowest performance; F1 score of 90%, the accuracy of 89%, the precision of 90%, recall of 90%, AUC of 89%, and RMSE of 0.32. When the algorithms' performances were compared, the highest accuracy was obtained from MobileNet, LeNet-5, VGG16, and VGG19, respectively. This study has proven the usefulness of deep learning models to detect COVID-19 in chest-CT images based on the proposed model framework. Therefore, it can contribute to the literature in Medical and Engineering in COVID-19 detection research.
AtıfScopus2OpenAlex2
İncele - MakaleAçık Erişim2022Scopus SJRQ240Ar–39 Ar dating, whole-rock and Sr-Nd isotope geochemistry of the Middle Eocene calc-alkaline volcanic rocks in the Bayburt area, Eastern Pontides (NE Turkey): Implications for magma evolution in an extension-related setting
Kaygusuz, Abdullah; Yücel, Cem; Aydınçakır, Emre; Gücer, Mehmet Ali; Ruffet, Gilles
Discussions continue about whether Middle Eocene magmatism in the Eastern Pontides is associated with collision or subduction. This paper presents new whole-rock geochemistry, Sr-Nd isotopic and 40Ar-39Ar age data for Middle Eocene volcanic rocks from the Bayburt area of the Eastern Pontides (NE Turkey) to investigate their sources and evolutionary history. The new 40Ar–39Ar ages reveal that these volcanic rocks erupted between 44.6 ± 0.1 Ma and 43.5 ± 0.1 Ma, within the Lutetian (Middle Eocene). The studied volcanic rocks are composed of basalt, andesite, basaltic andesite and minor dacite lava and pyroclastic rocks. These rocks consist of plagioclase, amphibole, pyroxene, olivine, biotite, sanidine and minor quartz phenocrysts with Fe-Ti oxides. They have microlithic, hyalo-microlithic, porphyritic and rarely glomeroporphyritic textures. The volcanic rocks have low to high-K calc-alkaline affinities. They display enrichment in large-ion lithophile elements and depletion in high-field strength elements with high Th/Yb ratios, which indicate that the magmas forming the volcanic rocks were derived from lithospheric mantle sources enriched by mostly slab-derived fluids in the spinel stability field. 87Sr/86Sr(i) values vary between 0.70485 and 0.70551 and 143Nd/144Nd(i) values vary between 0.51255 and 0.51267. These data correspond to the mantle array on the isotope ratio diagram. The main solidification processes consist of fractional crystallization with minor assimilation. In light of the data obtained in this study together with data from previous studies, petrogenetic character of the Middle Eocene magmas from the southern parts of the Eastern Pontides may be explained by melting of an enriched lithospheric mantle source initially metasomatized by subduction fluids in a post-collisional extensional-related tectonic setting.
AtıfScopus17WoS14OpenAlex20İncele - MakaleAçık Erişim2022Scopus SJRQ1A countrywide analysis of 27 solar power plants installed at different climates
Ozden, Talat
The world is still heavily using nonconventional energy sources, which are worryingly based on carbon. The step is now alternative energy sources hoping that they will be more environmentally friendly. One of the important energy conversion forms by using these sources is photovoltaic solar systems. These type of power plants is on the increase in everyday on the world. Before investment a solar power plant in a specified region, a techno-economic analyse is performed for that power plant by using several meteorological data like solar irradiance and ambient temperature. However, this analyses generally lacks evaluation on effects of climatic and geographical conditions. In this work, 5 years of data of 27 grid-connected photovoltaic power plants are investigated, which are installed on seven different climate types in Turkey. Firstly, the power plants are categorized considering the tilt angles and Köppen–Gieger climate classification. The performance evaluations of the plants are mainly conducted using monthly average efficiencies and specific yields. The monthly average efficiencies, which were classified using the tilts and climate types were from 12 to 17%, from 12 to 16% and from 13 to 15% for tilts 30°/10°, 25° and 20°, respectively. The variation in the specific yields decrease with elevation as y(x) = − 0.068x + 1707.29 (kWh/kWp). As the performances of photovoltaic systems for some locations within the Csb climatic regions may relatively lower than some other regions with same climate type. Thus, techno-economic performance for PVPP located in this climate classification should be carefully treated.
AtıfScopus6WoS2OpenAlex8İncele - MakaleAçık Erişim2022Scopus SJRQ1Seismic performance of a high-rise building by using linear and nonlinear methods
Çavdar, Özlem
In this paper, the seismic behavior of the existing reinforced concrete tall building is investigated by using the linear and nonlinear dynamic methods. The selected existing reinforced concrete structure was designed according to Turkey Seismic Code-2007. The performance analysis according to the Turkey Building Earthquake Code-2019 is realized in a 41-story reinforced concrete shear wall-framed structure in Istanbul where active fault lines are located. For high-rise building, firstly, spectrum analysis according to mode superposition methods of linear computational methods used within the scope of strength-based design is performed. Turkey Building Earthquake Code-2019 advises a nonlinear deformation-based design approach to determine more accurately the behavior of high-rise building, as in the earthquake regulations of other developed countries. In addition, the nonlinear time history analyses of building were performed. At the end of the study, torsional irregularity is seen on the normal floors and intermediate floor; stiffness irregularity was found on second floors. In addition, it has been observed in some of the oblique columns of the building that load bearing capacities were exceeded due to creep, axial compressive loads and severe damages occurred. According to the Turkey Building Earthquake Code-2019, the high-rise reinforced concrete shear wall building is not expected to satisfy life safety performance levels under design earthquake.
AtıfScopus5WoS3OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ2Warm up with music and visual feedback can effect Wingate performance in futsal players
Bayrakdaroglu, Serdar; Eken, Oezgur; Yagin, Fatma Hilal; Bayer, Ramazan; Gulu, Mehmet; Akyildiz, Zeki; Nobari, Hadi
Purpose: Visual feedback and music while warm up may help elicit peak performance, but its effect during the Wingate anaerobic test (WAnT) in futsal players is unexplored. Therefore, the aim of this study was to examine the effects of music and visual stimulus on WAnT performance in futsal players. Methods: The study included 17 young male futsal players (age, 21.53 +/- 1.32 years; height, 177.59 +/- 5.75 cm; 73.71 +/- 9.31 kg; BMI 23.342 +/- .47). The WAnT was administered using three distinct protocols: with music (M), without music (NM), and with music and visual feedback (MV) following a 10-min warm-up at 72-h intervals. After WAnT, the following parameters were evaluated: (a) peak power output: PPO (W), (b) relative peak power output: RPPO (W/kg), (c) mean power output: MPO (W), (d) relative mean power output: RMPO (W/kg), (e) fatigue index: FI (%), and (f) minimum power output MIPO (W). Results: MV indicated that futsal players' WAnT values, including PPO, RPPO, MPO, RMPO, and MIPO improved more than with other protocols (p < 0.05). However, there was no significant difference between protocols for FI (%) WAnT values (p > 0.05). Conclusions: Listening to music and watching visual feedback while warm up before performing WAnT performance suggest to coaches and futsal players.
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