Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(110)
- Güler, Ömer(70)
- Akkurt, Nevzat(69)
- Serdar, Osman(57)
- Yucesan, Melih(55)
- Celik, Erkan(53)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Bulut, Hasan(49)
- Baskonus, Haci Mehmet(48)
- Paksoy, Mehmet Yavuz(46)
- Yildirim, Numan(45)
- Kocabaş, Mehmet(41)
- Yildirim, Nuran Cikcikoglu(41)
- Zengin, Gokhan(40)
- Alataş, Mevlüt(39)
- Ince, Muharrem(38)
- Benzer, Fulya(37)
- Mete, Suleyman(34)
- Aslan, Naim(33)
- Kutlu, Banu(33)
- Yildirim, Ozal(33)
- Topal, Murat(32)
- Tanyol, Mehtap(30)
- Batan, Nevzat(28)
- Özkul, İskender(28)
- Kök, Mediha(27)
- Utku, Anıl(27)
- Can, Erkan(26)
- Danabas, Durali(26)
- Sulaiman, Tukur Abdulkadir(26)
- Ates, Mehmet(25)
- Ezer, Tülay(25)
- Guler, Omer(25)
- Kutluyer, Filiz(25)
- Say, Yakup(25)
- Serin, Faruk(25)
- Erguven, Gokhan Onder(24)
- Onat, Onur(24)
- Cakilcioglu, Ugur(23)
Yayınlar
- Kitap BölümüAçık Erişim2024High Entropy Materials for CO2 Conversion
Simsek, Telem; Guler, Seval H.; Guler, Omer; Simsek, Tuncay
Metal-based oxides, ceramics, and composite catalysts are commonly used for CO2 conversion. To increase the efficiency of these catalysts, strategies such as heterostructure, defect engineering, nanolayers, mesoporous structure development, and oxygen vacancy engineering are used. In recent years, highly stable high entropy alloys (HEAs), which include at least five different elements in equimolar or nearly equimolar ratios, have recently come to be recognized as promising CO2 conversion catalysts. Their unique properties enable enhanced reactivity and selectivity, making them highly valuable in addressing CO2 emissions and climate change challenges. When several elements are included in a catalyst, surface microstructures with different atomic configurations and active catalytic sites are produced. As a result, different adsorption modes arise for reactants and intermediates. In addition, the mixing of metal elements in varying atomic ratios causes changes in the electronic structure of metals. The distinct catalytic characteristics of HEAs are a result of modifications to their electronic structure brought on by lattice stretching, distortion, and compositional alterations.
- MakaleYalnız künye2024Scopus SJRQ2CeO2/SWCNT nanocomposite coating: A novel approach for corrosion application
Doğan, Fatih
The coatings were prepared by blending different concentrations of SWCNTs and CeO2 particles with an epoxy resin by hydrothermal method, which was then applied to the substrate through the doctor blade technique. The mixtures were transferred into a 1-L capacity autoclave with a teflon-lined flange type and subjected to hydrothermal treatment at 100°C for 3 h. The surface coatings were applied using a doctor blade. Subsequently, the coated materials were placed in an oven and dried for 12 h at 50°C under vacuum conditions. The samples' structural analysis was examined through x-ray diffraction (XRD). XRD analysis verified the CeO2/SWCNT composite coating, and Fourier transform infrared spectroscopy (FTIR) was utilized to assess the presence of functional groups. Thermodynamic properties and thermal stability of composite coatings that were modified with SWCNTs and CeO2 particles were studied by thermogravimetric analysis (TGA). The impact of the CeO2/SWCNT composite on the anticorrosion capabilities of the epoxy coating was examined through electrochemical impedance spectroscopy (EIS), Nyquist curve, and Tafel slope characterization. Corrosion tests were conducted on the CeO2/SWCNT composite coatings in a 3.5 wt% sodium chloride (NaCl) solution at 25°C to improve corrosion resistance. The concentration of 0.4 wt% CeO2 was found to be optimal for achieving effective corrosion resistance. The composite coating CNT0.6-C0.4 exhibited significantly higher Ecorr (−426 V) and lower Icorr (2.96 × 10−6 A cm−2) values compared to samples from the CNT0, CNT0.2, and CNT0.6 groups. The paper presents a viable solution with CeO2/SWCNT composite coating for the engineering application of corrosive-inhibiting coatings.
AtıfScopus1WoS1
İncele - MakaleAçık Erişim2024Scopus SJRQ1Spread patterns of COVID-19 in European countries: hybrid deep learning model for prediction and transmission analysis
Utku, Anıl; Akcayol, M. Ali
The COVID-19 pandemic has profoundly impacted healthcare systems and economies worldwide, leading to the implementation of travel restrictions and social measures. Efforts such as vaccination campaigns, testing, and surveillance have played a crucial role in containing the spread of the virus and safeguarding public health. There needs to be more research exploring the transmission dynamics of COVID-19, particularly within European nations. Therefore, the primary objective of this research was to examine the spread patterns of COVID-19 across various European countries. Doing so makes it possible to implement preventive measures, allocate resources, and optimize treatment strategies based on projected case and mortality rates. For this purpose, a hybrid prediction model combining CNN and LSTM models was developed. The performance of this hybrid model was compared against several other models, including CNN, k-NN, LR, LSTM, MLP, RF, SVM, and XGBoost. The empirical findings revealed that the CNN-LSTM hybrid model exhibited superior performance compared to alternative models in effectively predicting the transmission of COVID-19 within European nations. Furthermore, examining the peak of case and death dates provided insights into the dynamics of COVID-19 transmission among European countries. Chord diagrams were drawn to analyze the inter-country transmission patterns of COVID-19 over 5-day and 14-day intervals.
AtıfScopus6WoS3OpenAlex7İncele - MakaleYalnız künye2024Scopus SJRQ3Using the Particle Swarm Optimization (PSO) Algorithm for Baseflow Separation and Determining the Trends for the Yesilirmak River (North Turkey)
Acar, R.; Saplioglu, K.
Estimation of baseflow is a complex hydrographic task. Baseflow techniques and coefficients vary from basin to basin, stream to stream, and year to year. In this study, meta-heuristic optimization is used to automatically identify baseflow. The Particle Swarm Optimization (PSO), a meta-heuristic optimization approach, is chosen. The constraint and cost functions were determined using the PSO algorithm, Lyne and Hollick techniques, and a computer application. Over the period 1980–2015, the data were collected at the Kale station in the Yesilirmak River basin to validate the study model. The results show that the hydrographs and baseflow dividing line were separated effectively. It has also been revealed that the PSO has a high speed as well as a high level of precision. In the research, in addition to the baseflow separation, the hydrograph, baseflow, and ratio of the baseflow to the streamflow at the station No. 1402 were assessed using the Mann–Kendall test and Innovative Trend Test (ITA), and as a result, their trends have been found. By the use of both of these methods, it has been shown that all parameters have an unfavorable trend. In addition, the research came to some other significant conclusions, such as the fact that the baseflow declines in tandem with the flow values and that the baseflow rates are low in years with high peak values of the hydrograph.
AtıfScopus4WoS5OpenAlex6İncele - MakaleYalnız künye2024Scopus SJRQ2Dynamic Analysis and Metallographic Examination of Linings with Different Composite Contents used in the Brakes of a Hydraulic Turbine
Işık, Erdem; Kahraman, Gökhan
The main aim of this study was to find ways to increase the performance and life of generator brake linings, which can lead to cost reduction and adequate downtime periods for hydroelectric power plants. First, the dynamic analysis of the linings used in hydraulic turbines was realized and their reactions were examined under different operating conditions. Second, two types of brake linings with different composite components produced in the market were examined metallographically and tested to determine both the stopping performance and durability time of the turbine-generator unit for a sufficient period of time in the vertical 150-megawatt Francis turbine with approximately 500 tons of rotary weight. As a result of these experiments, the lining with the boron component led to much better results than the other brake linings. It has been determined that the boron-containing lining makes 100 stops more than the other lining and stops 20 s earlier in one stop. Therefore, the use of a composite lining with boron content in the braking systems of hydroelectric power plants significantly reduces maintenance incidents and operation costs as it prolongs brake replacement periods in these plants. Graphical Abstract: (Figure presented.)
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ1An innovative approach in oat milk production: Ohmic heating
Ak, Ferit; Karakavuk, Emrah; Goksu, Ali; Sabancı, Serdal
This study aimed to produce oat-milk by using the ohmic heating (OH) system and to compare some quality properties of this milk with the milk produced by conventional methods. The solution containing oats was heated from 20 °C to 75 °C using 3 different voltage-gradients, and then oat-milk was obtained by applying a series of processes. It has been determined that as the voltage gradient increased during heating in oat milk production, the processing time shortens, and this time was 482 seconds in the conventional heating process. The effective electrical conductivity values increased as the temperature increased in the OH process during the production of oat-milk and these values vary between 0.13 and 0.41 S/m. Also, some quality characteristics of oat milk such as color and total phenolic content were better preserved in milk obtained by the OH process than conventional heating process. In addition, oat milk obtained by OH process had higher apparent viscosity at all temperatures.
AtıfScopus8WoS6OpenAlex8İncele - MakaleAçık Erişim2024Scopus SJRQ1Exploring Chemical Composition, Antioxidant, Enzyme Inhibitory and Cytotoxic Properties of Glaucium acutidentatum Hausskn. & Bornm. from Turkey Flora: A Novel Source of Bioactive Agents to Design Functional Applications
Yagi, Sakina; Zengin, Gokhan; Uba, Abdullahi Ibrahim; Maciejewska-Turska, Magdalena; Sieniawska, Elwira; Świątek, Łukasz; Rajtar, Barbara; Bahşi, Muammer; Guler, Osman; Dall’Acqua, Stefano
The present study was performed to determine the chemical constituents, cytotoxicity, antioxidant and enzyme inhibition activities of the aerial parts of Glaucium acutidentatum Hausskn. and Bornm. (family Papaveraceae). Methanolic and aqueous extracts were prepared by maceration, homogenizer-assisted extraction (HAE) and infusion. Results showed that the highest total phenolic and flavonoids contents were obtained from the methanol extracts obtained by HAE (53.22 ± 0.10 mg GAE/g) and maceration (30.28 ± 0.51 mg RE/g), respectively. The aporphine, beznyltetrahydroisoquinoline, and protopine types of Glaucium alkaloids have been tentatively identified. Among them, glaucine was identified in all extracts. Flavonoids, phenolic acids, coumarins, organic acids and fatty acids were also detected. Methanolic extract obtained using the HAE method displayed the highest anti-DPPH (41.42 ± 0.62 mg TE/g), total antioxidant (1.20 ± 0.17 mmol TE/g), Cu2+ (113.55 ± 6.44 mg TE/g), and Fe3+ (74.52 ± 4.74 mg TE/g) reducing properties. The aqueous extracts obtained by infusion and HAE methods exerted the best anti-ABTS (103.59 ± 1.49 mg TE/g) and chelating (19.81 ± 0.05 mg EDTAE/g) activities, respectively. Methanolic extract from HAE recorded the highest acetylcholinesterase (2.55 ± 0.10 mg GALAE/g) and α-amylase (0.51 ± 0.02 mmol ACAE/g) inhibition activities, while that obtained by maceration showed the best butyrylcholinesterase (3.76 ± 0.31 mg GALAE/g) inhibition activity. Both extracts revealed the best tyrosinase inhibitory activity (25.15 ± 1.00 and 26.79 ± 2.36 mg KAE/g, p ≥ 0.05). G. acutidentatum maceration-derived aqueous extract showed selective anticancer activity against cells originating from human hypopharyngeal carcinoma. In conclusion, these findings indicated that G. acutidentatum is a promising source of alkaloids and phenolic compounds for variable pharmaceutical formulations.
AtıfScopus13OpenAlex13
İncele - BildiriAçık Erişim2024A Deep Learning-Based Approach for Damage Detection in Cultural Heritage Images and Generating Heat Maps
Ogdu, Cagatay Umut; Yilmazer, Merve; Karakose, Mehmet
Cultural structures may be damaged and damaged over time due to external factors such as natural and social disasters, which may lead to the loss of national assets if cultural assets are not protected. Therefore, the protection of cultural heritage is of great importance not only for today's generations but also for future. In recent years, deep learning and image processing have made great progress and have become very effective for detecting and analyzing patterns. These techniques can also be used to solve complex problems such as damage detection of structures in the field of cultural heritage. Deep learning methods can be used to determine the current status of structures and detect possible damage by working on images obtained from different angles of structures, while also reducing human errors. In this study, as an important step for the protection of cultural heritage, a detection method was developed using deep learning models on damaged and intact cultural heritage building images. The data set used in the study consists of damaged and intact cultural heritage building images. An attempt was made to determine the model that gave the best results by using pre-trained models with the Transfer Learning method. Heat maps were created using the Grad-CAM method to identify damaged areas on the trained models, thus making it possible to more clearly identify the damaged areas in the image. This method can play an important role in preserving cultural heritage. It can be used to detect damaged areas and direct them to repair.
AtıfScopus3OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ1Virtual reality for COPD exacerbation: A randomized controlled trial
Kizmaz, Erhan; Telli Atalay, Orçin; Çetin, Nazlı; Uğurlu, Erhan
Background: Pulmonary rehabilitation (PR) is an effective treatment method for chronic obstructive pulmonary disease (COPD). However, individuals with chronic diseases that require lifelong treatment and experience exacerbations need motivational methods. Objectives: The aim of this study was to examine the effects of virtual reality on symptoms, daily living activity, functional capacity, anxiety and depression levels in COPD exacerbation. Methods: Fifty patients hospitalized for COPD exacerbation were included in the study. They were randomly assigned to two groups. Twenty-five patients participated in a traditional PR (once-daily until discharge), including pedaling exercises. The second/25 patients followed the same protocol but experienced cycling simulation in the forest via virtual reality (VR + PR). All patients were evaluated using 1-minute/Sit-to-Stand test (STST), modified-Medical Research Council (mMRC) scale, COPD Assessment test (CAT), Hospital Anxiety and Depression Scale (HADS), and London Chest Activities of Daily Living (LCADL) before and after the treatment. Results: The STST showed an increase in both groups post-treatment, notably higher in the VR + PR (p = 0.037). Dyspnea levels and CAT scores decreased in all patients, but the decrease was greater in the PR + VR group for both parameters (p = 0.062, p = 0.003; respectively). Both groups experienced a reduction in the HADS scores compared to the pre-treatment, with a more significant decrease in depression and the total score in the VR + PR (p < 0.05). LCADL's sub-parameters and total score, excluding household, decreased in both groups after treatment (p < 0.05). The improvement was more substantial in the VR + PR. Conclusions: Virtual reality provides benefits in the management of COPD exacerbations and can be used safely. Clinical trial registiration: Registered at clinicaltrials.gov, registration ID: NCT05687396, URL: www.clinicaltrials.gov.
AtıfScopus11WoS11OpenAlex15İncele - MakaleYalnız künye2024Scopus SJRQ4How How Much Much CCondensation ondensation Occurs Occurs With With Various Various Insulation Insulation Thicknesses? Thicknesses?
Kahraman, Gökhan; Isik, Erdem
- MakaleAçık Erişim2024Scopus SJRQ2Smart alloy metalized novel photonic NEMS photodiode with CuAlV/n-Si/Al junction structure
Karaduman, Oktay; Canbay, Canan Aksu; Dere, Aysegul; Orman, Yusuf; Al-Ghamdi, Ahmed A; Al-Sehemi, Abdullah G; Yakuphanoglu, Fahrettin
In this work, a novel smart (shape memory) alloy metalized photonic silicon wafer photodiode with Schottky type CuAlV/n-Si/Al contact structure as a nano-electro-mechanical-system (NEMS) photodevice was fabricated by thermal evaporation technique. The CuAlV memory alloy used as the top Schottky metal contact electrode was produced by arc melting technique and a subsequent quenching in an iced-brine water medium, and its shape memory effect characteristics were revealed by thermal and structural tests. The fabricated photonic NEMS photodiode was characterized by different photo-electrical (I-V, I-t) and frequency/time dependent and illuminated capacitance (C-V/f, C-t, C-V/ill.) and conductance-voltage (G-V) measurements under different frequencies and artificial light intensity power conditions. The I-V tests showed an excellent current rectifying ability and very well net photocurrent generation features of the photodiode. The specific detectivity of the photodiode was found as high as almost approaching 1011 Jones. The SCLC (space charge limited current conduction) analyses made on the double-log I-V plots of the photodiode revealed that the trap-filling TFL-SCLC and trap-free SCLC current conduction mechanisms are the two prevailing conduction mechanisms in the forward bias voltage region. The density of interface states (Dit) of the fabricated photodiode was determined. Moreover, an excellent reproducibility of light-induced photocapacitance formation of the novel photodiode was demonstrated by C-V/t measurements under different artificial light power intensities.
AtıfScopus5OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ1A new algorithm to generate aes-like substitution boxes based on sine cosine optimization algorithm
Artuğer, Fırat; Özkaynak, Fatih
Symmetric encryption approaches are generally used for data encryption. One of the basic requirements for symmetric encryption algorithms to provide security is strong s-box structures. Because s-box is a nonlinear unit in these encryption algorithms and provides the requirement called confusion. In this article, a new technique is developed to produce effective s-boxes like the 16*16 s-box structure used in the AES algorithm. In the proposed method, the sine cosine algorithm (SCA), one of the recently developed optimization algorithms, is used. SCA is a suitable option for generating strong s-boxes because of its strong randomness and ease of implementation. The proposed method first uses a logistic map to generate the initial population. Then, the nonlinearity value is optimized with the help of the sine cosine algorithm. The proposed method reaches the highest nonlinearity value (112) by relocating 126 values in the s-box structure produced initially. Looking at the results, it is seen that the proposed method gives better results than other optimization-based s-box creation methods. This new method has significant potential to improve the security of symmetric encryption algorithms and make data encryption processes stronger.
AtıfScopus19WoS22OpenAlex24İncele - MakaleAçık Erişim2024Scopus SJRQ1Production of Ho2O3 and Dy2O3 rare earth oxides doped selenium thin film and investigation of surface morphology and optical properties
Aydin, Handan; Sait Kanca, M.; Kök, Mediha; Taşgin, Yahya; Tatar, Beyhan
Thin film technology aims to improve and develop the properties of materials by coating technology. In this study, thin films consisting of rare earth element and selenium semiconductor material, which have recently been preferred in technological applications due to their important properties, are examined. Selenium thin films doped with Ho2O3 and Dy2O3 rare earth oxides (REO) were fabricated on glass substrate by thermal evaporation method. The surface morphology and optical properties of the thin films were investigated. As a result of surface morphology examinations, it was determined that homogeneous thin films were obtained and the thickness of the thin films varied between 20 and 30 μm. In addition, the roughness value of the glass substrate decreased as a result of coating with doped selenium thin film. The band energy value obtained by UV-VIS measurements decreased compared to glass and was close to the selenium element value. In the comparison between selenium coatings doped with Ho2O3 and Dy2O3, a notable reduction in the Eg value was observed specifically in the Ho2O3 doped coatings.
AtıfScopus3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Introducing the chemical potential of Cu–Mn–Al alloys for structural, electrical and thermal properties
Yüzüak, E.; Durak Yüzüak, G.
This study investigates the Martensite transition in Cu–Mn–Al alloys (CMAs) via the use of many methods, including scanning electron microscopy, temperature-dependent X-ray diffraction, resistivity and thermal measurements. The Martensite transition hysteresis and characteristic temperature are primarily determined by the alloy composition, crystal structure and residual stress. Furthermore, these alloys have been reported to have surface and crystallographic characteristics often associated with twinning structures. Resistivity experiments conducted during heating and cooling cycles demonstrate a 2.57-fold increase inside the phase change zone, emphasizing the influence of the transition on electrical conductivity. The Martensite transition temperature may be altered by 110 K by the manipulation of the electron-to-atom ratio (e/a), indicating the high susceptibility of this temperature to changes in chemical composition. Differential scanning calorimetry shows that the transition is accompanied by a maximum entropy shift of 48 J kg−1. K, which offers valuable information on the thermodynamic driving factors involved. This work successfully attains a cooling power of 1350 W, which is equivalent to the cooling power of NiTi wire (1500 W), by using a theoretical manufacturing method and optimizing the CMAs. Overall, this work clarifies the Martensite transition in CMAs, highlighting its impact on their characteristics and indicating their potential for effective thermal energy storage and release applications. It is advisable to further optimize their performance and economic viability by considering the e/a ratio.
AtıfScopus3WoS3OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ1Influence of praseodymium oxide on the structural, mechanical and photon, charged particles, and neutron shielding properties of alumina borate glass
Acikgoz, Abuzer; Izguden, Ilyas; Tasgin, Yahya; Yilmaz, Demet; Demircan, Gokhan; Kalecik, Sedanur; Aktas, Bulent
The structural, mechanical and radiation shielding properties of (69-x)B2O3-20TeO2-10Al2O3-1HfO2-xPr6O11 (where x = 0, 0.25, 0.5, 0.75, 1 mol %) glass system were investigated. This study introduces a novel approach by incorporating Pr6O11 into glass composition, highlighting its unique contributions to enhancing elastic properties, fracture toughness, hardness, and radiation shielding abilities. Experimental measurements were conducted within the energy range of 59.54–661.62 keV and theoretical calculations are made for MAC values. The presence of Pr6O11 was noted to positively influence the gamma shielding capabilities. At 59.54 keV, the addition of 0.25 mol% Pr6O11 increased the mass attenuation coefficient of the glass by 2.9 %, and the addition of 1 mol% Pr6O11 increased it by 29.8 %. The addition of 0.25 mol% Pr6O11 increased the fast neutron removal cross section of the glass by 4.4 %. Also, it is observed that the glass with 1 mol% Pr6O11 is the best shielding material against alpha and proton particles. A significant enhancement of 24.36 % in the fracture toughness value was observed, increasing from 1.059 to 1.317 MPa m1/2 at 1 mol% Pr6O11. Experimental hardness values increased from 3.374 to 3.985 GPa, resulting in an improvement of 18.11 % at 1 mol% Pr6O11. The thermal stability (ΔT, °C) value demonstrated a notable increase from 85 to 106, indicating a significant 24.7 % improvement at 0.25 mol% Pr6O11.
AtıfScopus58WoS57OpenAlex60İncele - MakaleAçık Erişim2024Scopus SJRQ1A broad-spectrum biological activities of Heracleum humile extracts: A first report of the antiviral, anti-cancer and chemical properties
Ocal, Mustafa; Duran Yelken, Selda; Altunoglu, Yasemin Celik; Baloglu, Mehmet Cengiz; Soomro, Sanam Iram; Zengin, Gokhan; Angeloni, Simone; Mustafa, Ahmed M.; Caprioli, Giovanni; Paksoy, Mehmet Yavuz
The current work focused on researching the bioactive potential of ethyl acetate (EA), methanol (MeOH), and water extract of H. humile plant, specifically ethyl acetate, methanol extracts were acquired with maceration method, and water extract was obtained by the infusion method. The highest total phenolic ingredient was determined in the water extract, while the highest total flavonoid ingredient was found in the MeOH extract. The water extract displayed the most potent antioxidant activity in the assays used. The ethyl acetate extract showed the highest enzyme inhibition activity in Butyrylcholinesterase inhibition (BChE) and amylase assay. Antibacterial efficiency was analyzed using microdilution analysis. The minimum inhibitory concentration (MIC) amounts ranged from 125 to 500 μg/mL except for water extract. The antiviral potential of the extracts was assessed against Bovine herpes virus 1 (BoHV-1) (Cooper strain). Methanol extract showed more potent antiviral effect. Selectivity indices were calculated for ethyl acetate and methanol extract as 3.32 and 13.39, respectively. All extracts displayed Deoxyribonucleic Acid (DNA) protection activity at approximately 25%–35%. For cell viability evaluation, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) test was performed against triple-negative human breast adenocarcinoma cells (MDA-MB-231) and Michigan Cancer Foundation-7 (MCF-7) cells. The most effective results were found in ethyl acetate extract at 48h. The 50% inhibitor concentrations (IC50) were determined for MDA-MB-231 and MCF-7 as 116.7 μg/mL and 247.9 μg/mL, respectively. Based on the bioactive compound content results, extracts of H. humile include valuable compounds that possess significant biological properties. In conclusion, these extracts could offer promising novel plant-derived therapeutics.
- MakaleAçık Erişim2024Scopus SJRQ1Morphometric characteristics of glacial cirques and former glaciers in the Geyik Mountains, Western Taurus, Türkiye
Çılğın, Zeynel; Evans, Ian S.; Keserci, Ferhat; Canpolat, Ergin; Bayrakdar, Cihan
Using the Glacier reconstruction (GlaRe) toolbox, reconstructions of former glaciers in the Geyik Mountains, part of the Taurus Mountain system in southern Türkiye, show that an area of 132.5 km2 was glaciated in the last major glaciation, which left clear terminal and hummocky moraines. Glaciers were 1.4 to 12 km long and those from 49 cirques merged to form a broad 75 km2 piedmont glacier in the Namaras Valley, up to 400 m thick. A thorough analysis of morphometry of the 98 Geyik cirques, using the revised Automated Cirque Metric Extraction version 2 (ACME2) toolbox, shows that they are relatively small, with limited widths: the median length/width ratio of 1.29 is unusually high. With size, length and width increase faster than depth, demonstrating strong static allometry. Maximum slope averages 59°, minimum 3.3° and axial 25°. A combination of low hypsometric integral, high axial profile closure and high axial height-length integral is proposed as a measure of cirque development. The main summits are on sharp ridges on cirque crests, showing that they have been lowered by glacial erosion (by cirque development). Glaciation was strongly asymmetric, with cirque vector mean aspect between northeast and north-northeast. This shows the dominance of solar radiation effects, with some modification from westerly winds. Glacier palaeo- Equilibrium Line Altitudes (pELAs) rise northeastwards and cirque floor minimum altitudes (CFAs) rise toward east-northeast, both showing the importance of moist air from the Mediterranean, 38–55 km to the southwest. pELA averages 2208 m above sea level (a.s.l.) (2277 m area-weighted); CFA averages 2234 m. CFA varies mainly with summit altitudes; where related palaeoglaciers are short CFA is somewhat below pELA, but for longer ones it is above. The most likely palaeoclimate to form these glaciers involves a precipitation increase of 53–72 % with a temperature fall of 8 °C compared with present-day. The cirques formed under similar or less severe conditions.
AtıfScopus7OpenAlex15İncele - MakaleAçık Erişim2024Scopus SJRQ1A new hybrid approach for grapevine leaves recognition based on ESRGAN data augmentation and GASVM feature selection
Doğan, Gürkan; Imak, Andaç; Ergen, Burhan; Sengur, Abdulkadir
Grapevine leaf is a commodity that is collected only once a year and has a high return on investment due to its export. However, only certain types of grapevine leaves are consumed. Therefore, it is extremely important to distinguish the types of grapevine leaves. In particular, performing this process automatically on industrial machines will reduce human errors, workload, and thus cost. In this study, a new hybrid approach based on a convolutional neural network is proposed that can automatically distinguish the types of grapevine leaves. In the proposed approach, firstly, the overfitting of network models is prevented by applying data augmentation techniques. Second, new synthetic images were created with the ESRGAN technique to obtain detailed texture information. Third, the top blocks of the MobileNetV2 and VGG19 CNN models were replaced with the newly designed top block, effectively extracting features with the data. Fourthly, the GASVM algorithm was adapted and used to create a subset of the features to eliminate the ineffective and unimportant ones from the obtained features. Finally, SVM classification was performed with the feature subset consisting of 314 features, and approximately 2% higher accuracy and MCC score were obtained compared to the approaches in the literature.
AtıfScopus8WoS6OpenAlex9İncele - MakaleYalnız künye2024Scopus SJRQ2A new S-box generator algorithm based on chaos and cellular automata
Artuğer, Fırat
S-boxes are very important structures for encryption algorithms. For S-boxes to be strong, they should not be as linear as possible. Obtaining an S-box with high nonlinearity is a difficult problem. For this reason, it has attracted the attention of researchers for many years. In this study, cellular automata logic was used to overcome this problem. A chaotic tent map was used for the initial population. Then, in this weak S-box, the elements were replaced with their neighbors, and the nonlinearity value was checked. When this value increased, the S-box was transferred to the next generation. With the proposed algorithm, an S-box structure with a nonlinearity value of 110.5 was obtained. This value surpasses most studies in the literature. In addition, it has been proven because of the analysis that the proposed S-box also provides other performance criteria.
AtıfScopus6WoS8OpenAlex7İncele - MakaleAçık Erişim2024Scopus SJRQ1Experimental and theoretical results of gamma shielding features for copper based shape memory alloys
Niksarlıoğlu, Seçil; Akman, Ferdi; Agar, Osman; Kaçal, Mustafa Recep; Kanca, Muhammed Sait
In this study, the gamma ray attenuation characteristics for CuAlNi shape memory alloys with different proportions of Sn doping was investigated. We determined the mass attenuation coefficient (μ/ρ) of CuAlNiSn alloys both experimentally and theoretically within an energy range of 59.5–1332.5 keV. The experimental measurements were made using a high purity Germanium detector (HPGe) and theoretical calculations were made using WinXCOM program. To evaluate the gamma radiation shielding abilities of the alloy samples, the obtained (μ/ρ) values were used to determine the gamma protection parameters μ, HVL, TVL, MFP, and Zeff. In addition, the radiation protection efficiency (RPE) parameter was determined using gamma ray intensities in the absence and presence of the attenuator. Further analysis of the samples was conducted using a Rigaku Miniflex 600 model computer-controlled X-ray diffractometer (CuKα & λ = 1.5405 A0). The crystallographic structure of the alloys before and after irradiation was investigated. Other analysis which include EDX analysis (to investigate the chemical content) and SEM analysis (to investigate the microstructure) were conducted. According to result outcomes, gamma ray radiation did not affect the shape memory properties of structure. Another interesting observation is that, the radiation attenuation properties increase with increasing Sn concentration. Finally, we discovered that the CuAlNiSn4 alloy (which has the highest doping rate) provides good protection especially at low energy levels.
AtıfScopus5OpenAlex6İncele