Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Öztekin, Ertekin(3)
- Şenaslan, Fatih(3)
- Alkan, Hamdi(2)
- Anaç, Halil(2)
- Baltaci, Cemalettin(2)
- Seferoğlu, Mehmet Tevfik(2)
- Taşdemir, Muharrem(2)
- Çelik, Ayhan(2)
- Öztürk, Serkan(2)
- Ahmed, Sana(1)
- Akaryali, Enver(1)
- Akay, Şeref(1)
- Akinoglu, Bulent G.(1)
- Akyildiz, Esma(1)
- Almasani, Heba(1)
- Arslan, Mikail(1)
- Aydin, Murat(1)
- Beriş, Fatih Şaban(1)
- Bingöl, Sait(1)
- Bostan, Sinan(1)
- Budak, Selahattin(1)
- Cam, Handan(1)
- Catal Reis, Hatice(1)
- Dağ, Serhat(1)
- Demirel Ozbek, Yagmur(1)
- Fidan, Muhammed Said(1)
- Gurcan, Fatih(1)
- Gül, Abdulkadir(1)
- Gültekin, Zarife(1)
- Gündoğdu, Engin(1)
- Karabudak, Filiz(1)
- Karpuz, Ömer(1)
- Kartal, Abdullah(1)
- Kaya, Selim(1)
- Kaya, Serhat(1)
- Kocyigit, Emine(1)
- Koçak, Tevfik(1)
- Köse, Tuba(1)
- Lermioğlu, Fatma(1)
- Olgun, Ali(1)
Yayınlar
- MakaleAçık Erişim2023Effect of aging time and temperature on properties of AA7075 alloy; [Yaşlandırma süresinin ve sıcaklığının AA7075 alaşımının özelliklerine etkisi]
Budak, Selahattin; Çolak, Harun; Yakut, Yusuf
In this study, the effect of aging at different temperatures and times on the properties of AA7075-T6 alloy was investigated. The samples prepared for the experimental studies were subjected to the solution, quenching, and then aging heat treatment at 100 °C and 200 °C for different periods (42-66-90 hours). The properties of the experimental samples were investigated by hardness, compression test, and scanning electron microscope (SEM). As a result of the studies, it was determined that the aging heat treatment had a positive effect on the microstructure and mechanical properties of the AA7075 alloy compared to the reference sample. Especially as a result of the heat treatments at 100 °C, higher results were obtained in hardness and compression strength compared to the initial values.
- MakaleAçık Erişim2023The new numerical solutions of conformable time fractional generalized Burgers equation with proportional delay; [Oransal gecikmeli uyumlu zaman kesirli mertebeden genelleştirilmiş Burgers denkleminin yeni sayısal çözümleri]
Kartal, Abdullah; Anaç, Halil; Olgun, Ali
The conformable time-fractional partial differential equations with proportional delay are studied using two new methods: the conformable fractional q-homotopy analysis transform method and the conformable Shehu homotopy perturbation method. The numerical solutions to this equation are graphed. Numerical simulations show that the proposed techniques are effective and trustworthy.
- MakaleAçık Erişim2022Production of high-transparent MgO films by radio-frequency sputtering method; [Yüksek geçirgen MgO filmlerin radyo frekansı saçtırma yöntemiyle üretimi]
Şenaslan, Fatih; Çelik, Ayhan; Taşdemir, Muharrem
Magnesium oxide (MgO) thin films were deposited on silicon and glass substrates by the radio frequency (RF) sputtering method. The MgO films were annealed at 400 ⁰C for 4h. The effect of working pressure on the structure and optical properties of MgO films was investigated. Structural characterization of thin films was determined using the X-ray diffraction (XRD) method. XRD results showed the presence of dominant peaks corresponding to the (200) and (220) lattice planes of MgO. However, peaks corresponding to (111), (311) and (222) lattice planes of the MgO also appeared in the films deposited at low pressure. It was determined that the average crystal size decreased as the working pressure reduced, while the deposition rate increased. SEM analysis showed that the microstructure of the nano-spherical MgO film transformed into a coarse-grained nano-pyramidal shape after annealing. The optical properties of MgO films were investigated by UV-Vis spectroscopy. Accordingly, it was determined that the absorption threshold of the films was around 310 nm wavelength and the optical band gap of the films varied between 4.07 and 4.14 eV. As a result, MgO films with high transmittance reaching an average of 95% in the visible region were obtained.
- DüzeltmeAçık Erişim2022Production of high-transparent MgO films by radio-frequency sputtering method; [Yüksek geçirgen MgO filmlerin radyo frekansı saçtırma yöntemiyle üretimi]
Şenaslan, Fatih; Çelik, Ayhan; Taşdemir, Muharrem
In the article with " Şenaslan, F., Çelik, A. & Taşdemir, M. (2022). Production of high-transparent MgO films by radio-frequency sputtering method. Gümüşhane University Journal of Science, 12(1), 320-326. DOI: 10.17714/gumusfenbil.1006430” citation information which was published in the first issue of the twelve volume of the Gümüşhane University Journal of Science, it was noticed that the “4. Conclusion (4. Sonuçlar)” section of the acceptance article Publisher was unintentionally removed by preparing for a publish, although authors given a “4. Conclusion (4. Sonuçlar)” section in the acceptance article. We apologize to the readers for the mistake. In this erratum, the unintentionally removed conclusion section is presented in the related article.
- MakaleAçık Erişim2022Investigation of microstructural change and damping behaviour of Zn–27Al– 1Cu alloy in different aging periods; [Zn–27Al–1Cu alaşımının farklı yaşlandırma periyotlarında mikroyapısal değişiminin ve darbe davranışının incelenmesi]
Şenaslan, Fatih; Aydin, Murat
The ternary Zn–27Al–1Cu alloy is produced from raw materials by the gravity casting method. The produced alloy was subjected to aging after solutionizing and quenching. The effect of aging at different periods on the microstructure and damping behaviour of the alloy was investigated. The microstructural investigations revealed that the microstructure of the alloy in the as-cast state consisted of aluminium(Al)-rich α dendrites surrounded by eutectoid β phase, and zinc(Zn)-rich η phase and copper(Cu)-rich ε phase. The heat treatment eliminated the dendritic microstructure of the casting alloy and transformed it into a coarse-grained (β-matrix) stable form containing Zn-rich and Cu-rich precipitates. The microstructural changes after aging process were directly affected the mechanical properties of the alloy. The hardness and tensile strength increased with increasing ageing time up to 2.5 hours, but the percent elongation decreased. When the aging time reached 5 hours, hardness and tensile strength decreased while percent elongation increased significantly. The impact energy, namely toughness, increased in the early stage of aging, reduced sharply with increasing aging time and remained stable with a small increase in the prolonged stage of aging. The highest impact energy was attained from the aged alloy for 0.5 hours. The variation in damping energy was dependent on the changes in microstructural and mechanical properties caused by different aging periods. The prolonged aging process transformed the fracture characteristic of the as-cast alloy from relatively brittle to ductile fracture.
- 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.
- MakaleAçık Erişim2021Fuzzy inverse logic: part-2. validation and evaluation of the method; [Bulanık ters mantık: kısım-2. yöntemin doğrulanması ve değerlendirilmesi]
Öztekin, Ertekin
In the first part of this study, which consists of two parts, the introduction of the fuzzy inverse logic method, its foundations, computation and process flow and details were given. In this second part, the method was applied on a very simple mathematical problem and on a simple civil engineering design problem in order to investigate and evaluate the validity of the method easily. Fuzzy inverse logic computations have been carried out on these two simple problems for different dimension, sensitivity and acceptable error values. By comparing the obtained results with the desired outputs and mathematical results, the effective computation ability of the method was tried to be revealed. As a result, it is understood that the method developed in this study has many promising aspects in terms of theoretical computations and practical applications and can be used effectively in many scientific fields.
- MakaleAçık Erişim2021Production and characterization of zinc oxide nanoparticles in microsystems via green synthesis; [Yeşil sentez yoluyla mikrosistemlerde çinko oksit nanopartiküllerin üretimi ve karakterizasyonu]
Akay, Şeref; Sefaoğlu, Melike
Nanoparticles (NP), which can be produced for many different fields and purposes; are at size vary from nanometer to a micrometer. These particles can be prepared by different approaches such as chemical, physical and biological methods. However, the biological approach is the most promising approach among other methods due to its simplicity and environmentally friendly conditions. The production of the nanoparticle by means of a biological approach does not require any high temperature, acidic/basic conditions and hazardous chemicals. Therefore, this method is named “green synthesis”. Development in microtechnology has had profound effects in many areas such as drug discovery, biology, diagnosis, and tissue engineering. Microfluidics which focuses on the processing of liquids in microscale systems has attracted wide attention in the production process of nanoparticles due to precise control and fast mixing. The main purpose of this study is to produce and characterize metal nanoparticles by combining microsystems and green synthesis approaches. For this purpose, in the first step, the design of microsystems that suitable for the flow of different phases was performed. In the second step, ZnO nanoparticle synthesis was carried out using the red cabbage (Brassica oleracea var.capitata f. Rubra) extracts. The synthesis of nanoparticles achieved by optimizing different parameters such as; extract: zinc ratio, zinc solution concentration, flow rates, and flow rates ratio in the microsystem and temperature. The results showed that the herbal red cabbage components can be used for the green synthesis of ZnO nanoparticles.
- MakaleAçık Erişim2021Fuzzy inverse logic: part-1. introduction and bases; [Bulanık ters mantık: kısım-1. giriş ve temeller]
Öztekin, Ertekin
In almost all deterministic and artificial intelligence techniques, for the solution of the scientific problems such as design and control problems, the output estimations are performed depending on manuplations on the values of input variables. With the other words, lots of different values derived from input parameters are tried in order to obtain desired output(s). Contrary to these conventional estimation methods, this study consists of two parts in which a new artificial intelligence method called fuzzy inverse logic(FIL) is developed to determine or estimate the value of the input parameters that give the targeted problem output. In the first part of this study, after providing a brief overview about the method of classical fuzzy logic(FL), the solution approaches and calculation details about FIL are given. In the second part of the study, fuzzy inverse logic method was used to solve one simple mathematical problem and one simple civil engineering problem. After the validity of the developed method was demonstrated by graphics and tables. some evaluations were made about the method.
- MakaleAçık Erişim2021Fatigue analysis of the vehicle brake disc; [Araç fren diskinin yorulma analizi]
Karabudak, Filiz
In this study, the fatigue analysis of the vehicle brake disc was simulated using the finite element program, and life calculations were made in accordance with the analysis. The main purpose is to simulate experimental tests, which take a long time to result, in the computer environment and to obtain results in a short time and at a very low cost. With the help of the ANSYS computer program, which operates with the finite element logic, the disk brake system was created in three dimensions, and the boundary conditions closest to reality were determined and analyzed using the finite element method. In the disc brake system selected, the data obtained by conducting stress, fatigue life, and safety coefficient analyses in line with the forces formed on the wheel and the vehicle during braking were examined. According to the analysis results, our brake disc is in different life ranges in accordance with the material used and the load applied, and when the force is increased, the life decreases and vice versa.
- DergiGumushane Universitesi Fen Bilimleri Dergisi