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Öğe Finite element method based structural analysis of quadcopter UAV chassis produced with 3D printer(2020) Aydın, Mustafa; Çaşka, Serkan; Gök, Kadir; Özdemir, İkbalIn this study, the static analysis and manufacturing of a quadcopter type small unmanned aerialvehicle (UAV) design compatible with landing platforms was performed by using the finite elementmethod. In static analysis, the weight of the quadcopter body is considered as the load and the base isfixed. Each part of the quadcopter used in the Finite Element Analysis (FEA) is manufactured withAcrylonitrile Butadiene Styrene (ABS) and Polyactic Acid (PLA) materials with a thickness of 0.05mm with i3 prusa printer. As a result of the structural analysis, the stress produced in the quadcopterchassis produced from ABS material was 0,053 MPa and the stress on the quadcopter frame producedfrom PLA material was calculated as 0,065 MPa. In addition, the deformation in the quadcopter frameproduced from ABS material was 0,014 mm, while the quadcopter frame produced from PLA materialwas 0,010 mm.Öğe Design and finite element analysis of a new kirschner wire for fixing bone fractures in orthopedic surgery(2022) Ada, Deniz; Gök, Kadir; İnal, CananIn this study, a new Kirschner wire (K-wire) design was performed to fix bone fractures in orthopedic surgery. The numerical analyses were completed based on the finite element method (FEM), using Deform-3D software. In this kind of numerical analyses using the FEM, friction, material model, the load and boundary conditions must be defined correctly. It has been seen that the new design is more advantageous in terms of implant failure or stability of fracture fixation. In addition, a good compatibility was found between the experimental results and the finite element analysis (FEA) results. This confirmed the accuracy of the finite element model. Therefore, this finite element model can be used reliably in drilling processes. We believe that with the use of new design investigated may have the role on the patients taking away from recurrent anesthesia and orthopaedic surgical risk.Öğe Güneş pilleri uygulamalarında kullanılan organik tabanlı Schottky diyotlarında iyonize radyasyonun aygıt parametrelerine etkisi(2021) Ocak, Sema Bilge; Barış, Behzad; Karadeniz, Serdar; Karadeniz, Hande; Selçuk, Akil BirkanBu çalışmada, organik araüzeyli Schottky yapısına iyonize radyasyonun etkileri araştırılmıştır. Hazırlanan metal/koronen/n-Si Schottky yapılar, değişik dozlarda gama radyasyonuna maruz bırakılmış ve bu yapıların ışınlama öncesi ve sonrası performans parametrelerindeki değişimler incelenmiştir. Organik arayüzey tabaka olarak koronen malzemesi kullanılmıştır. Arayüzey malzemesi döndürme ile kaplama tekniği kullanılarak, değişik kimyasal yöntemlerle temizlenmiş olan n-tipi silisyum tabanlar üzerine ince film olarak kaplanmıştır. Yapıların radyasyon öncesi ve sonrası elektriksel karakteristiklerindeki değişimler karanlık ortamda ve oda sıcaklığında I-V, C-V ve G-V ölçüm teknikleri kullanılarak incelenmiştirÖğe An ınvestigating on DNA binding activity of zn(II) phthalocyanine complex having tetra substituted phenoxy-3-methoxybenzoic acid group(2022) Ballı, Zekeriya; Ağırtaş, Mehmet Salih; Arslantaş, AliThe tetra substituted Zn(II) phthalocyanine complex having the dicyanophenoxy)-3-methoxybenzoic acid group had been obtained from 4-(3, 4-dicyanophenoxy)-3-methoxybenzoic acid and analyzed with the application of FT-IR, NMR, UV/Vis techniques in compliance withreported literature. The interacting property of Pc4 by CT-DNA was examined with absorption bands, emission titrations, melting temperature, viscosity, and gel electrophoresis procedures. The obtained findings from these techniques demonstrated that the complex containing the dicyanophenoxy)-3-methoxybenzoic acid binds to the DNA by means of intercalation attachment mechanisms.Öğe The optimization of driller parameters for orthopedic surgery applications using multiobjective gray relational analysis and response surface method(World Scientific Publ Co Pte Ltd, 2022) Gök, Arif; Gök, Kadir; Alkan, Mehmet AliIn bone-drilling operations, undesirable temperature rises are experienced due to high-contact friction. These increases in temperature can damage bone and soft tissues from time to time. When the temperature exceeds 47 degrees C, osteonecrosis occurs. This article presents a new method for both the selection of optimum drilling parameters and the mathematical temperature model (T degrees C). In this study, the optimum parameter values for bone-drilling operations were found using gray relational analysis, and a mathematical model was created based on the temperature parameters using the response surface method. The accuracy of the developed analytical model has been proven by ANOVA. As a result, it has been revealed that the value of spindle speed is the most effective factor in bone-drilling operations and that the developed analytical model and experimental measurements are in harmony.Öğe Experimental determination of biofilm and mechanical properties of surfaces obtained by CO2 laser gas-assisted nitriding of Ti-6Al-4V alloy(World Scientific Publ Co Pte Ltd, 2022) Urtekin, Levent; Aydın, Şeyhmus; Sevim, Ali; Gök, Kadir; Uslan, IbrahimThe nitriding process is a surface treatment that improves the surface properties of titanium alloys and increases wear/corrosion resistance. This study investigates the structural and mechanical property changes in titanium alloy after nitriding. Micro-hardness differences between the nitrided and non-nitrided surface and morphological changes on the surface were determined. In addition to evaluating the effect of vanadium and aluminum ions on the nonnitrided surface, the impact of nitrided and non-nitrided surfaces on biofilm layer formation was investigated. It was determined that the TiN layer formed on the nitrided surface showed superior properties to its non-nitrided surface in the biofilm tests performed for 6 h. As a result of the tensile tests, it can be said that the nitriding process increases the elasticity module of the Ti-6Al-4V alloy and provides the material to have a more rigid structure. It was also analyzed using finite element analysis (FEA) of mechanical behaviors of the test sample under the tension loads.Öğe Effects of post-uv-curing on the flexural and absorptive behaviour of fdm-3d-printed poly(lactic acid) parts(Mdpi, 2023) Akderya, TarkanIn this study, the effects of the post-ultraviolet-curing process on the flexural, absorptive, and morphological properties of poly(lactic acid) specimens produced using a fused deposition modelling technique 3D printer were experimentally investigated. In this direction, 15, 30, 45, and 60 min post-UV-curing processes were applied to poly(lactic acid) three-point bending and absorption specimens produced at 190 and 200 degrees C. Three-point bending tests and morphological analyses were applied after the post-ultraviolet-curing process, and absorption tests were applied by immersing the post-ultraviolet-cured specimens in a distilled water bath for 1-, 3-day, and 1-, 2-, and 4-week exposure times. The changes in flexural strain properties for each experimental parameter were also simulated by the computer-aided finite element analysis and compared with the experimental results. It was observed that the post-ultraviolet-curing process increased the flexural strength of the poly(lactic acid) specimens produced at both 190 and 200 degrees C with the same increasing trend up to 30 min of exposure, and the most significant increase was determined in the specimens that were subjected to post-ultraviolet-curing for 30 min. Although the flexural strengths of the post-ultraviolet-cured specimens were higher than the non-cured specimens in all conditions, it was detected that they tended to decrease after 30 min.Öğe Comparison of the success of meta-heuristic algorithms in tool path planning of computer numerical control machine(World Scientific Publ Co Pte Ltd, 2022) Çaska, Serkan; Gök, Kadir; Gök, ArifCarrying out an engineering process with the least cost and within the shortest time is the basic purpose in many fields of industry. In Computer Numerical Control (CNC) machining, performing a process by following a certain order reduces cost and time of the process. In the literature, there are research works involving varying methods that aim to minimize the length of the CNC machine tool path. In this study, the trajectory that the CNC machine tool follows while drilling holes on a plate was discussed within the Travelling Salesman Problem (TSP). Genetic Algorithms (GA), Particle Swarm Optimization (PSO), and Grey Wolf Optimizer (GWO) methods were used to solve TSP. The case that the shortest tool path was obtained was determined by changing population size parameter in GA, PSO, and GWO methods. The results were presented in tables.Öğe A micromechanical approach to elastic modulus of long-term aged chicken feather fibre/poly(lactic acid) biocomposites(Walter De Gruyter Gmbh, 2022) Akderya, Tarkan; Özmen, Uğur; Baba, Buket OkutanThe modulus of elasticity is a critical parameter for the performance design and analysis of biofibre-based biocomposite materials. As a result of criteria such as internal heterogeneity, the random distribution of fibres and the success of interfacial adhesion between the fibre and the matrix, it becomes difficult to predict the modulus of elasticity in practical ways. Therefore, one of the aims of this study is to determine the modulus of elasticity of biocomposite material reinforced with discontinuous and random fibres by means of micromechanical models and experimentally. In addition, it is also aimed to reveal which micromechanical model can be used reliably in predicting the modulus of elasticity of both aged and non-aged biocomposite materials due to the relationship between the analytical and experimental results. In order to achieve these objectives, initially, chicken feather fibre/poly (lactic acid) biocomposite specimens having 2, 5 and 10 % chicken feather fibre mass fractions were mixed and manufactured by extruding, and subsequently, tensile test specimens according to the appropriate standard were formed by the injection-moulding method. An agreement between the moduli of elasticity obtained from 6 micromechanical models and experimentally from the slope of the stress-strain curves resulting from tensile tests was determined.Öğe The study on biological activities of silver nanoparticles produced via green synthesis method using Salvia officinalis and Thymus vulgaris(Scientific And Technological Research Council Turkey, 2022) Ödemiş, Ömer; Özdemir, Sadin; Gonca, Serpil; Arslantaş, Ali; Ağırtaş, Mehmet SalihIn the present study, Ag nanoparticles (AgNPs) were synthesized from Salvia officinalis and Thymus vulgaris, known as phytotherapy plants. The obtained silver nanoparticles were characterized using SEM, XRD, FTIR, and UV/Vis spectra. The antioxidant capacities of Salvia officinalis-mediated AgNP (SO-AgNP) and Thymus vulgaris-mediated AgNP (TV-AgNP) were analyzed in vitro using 1,1-diphenyl-2-picrylhydrazyl and iron chelating activity assays. DPPH activities were 83.74% and 57.17% for SO-AgNP and TV-AgNP at concentration 200 mg/L, respectively. Both green synthesized AgNPs exhibited good iron chelating activity. In addition, the DNA cleavage activities of SO-AgNPs and TV-AgNP were investigated with agarose gel electrophoresis technique. SO-AgNPs and TV-AgNP showed single-strand DNA cleavage activity. AgNPs showed that the SO-AgNP and TV-AgNp were effective against bacteria and fungi, and antimicrobic activities were assessed as minimal inhibition concentration (MIC). Remarkably, green synthesized AgNPs showed highly effective cell viability and biofilm inhibition effect. AgNPs also demonstrated slightly antimicrobial photodynamic activity after LED irradiation.Öğe Investigation of the friction and wear properties of nitrided 7075-T6 aluminum alloy under vacuum and ambient air(Pamukkale Univ, 2022) Ghahramanzadeh Asl, Hojjat; Sert, Yasar; Bayrak, Özgü; Kucukomeroglu, TevfikAl7075 alloy is commonly used in the automotive industry, components of military vehicles and aircraft, rubber and plastic moulds. Also, similar Al alloys are frequently used for mechanical parts in space exploration. Therefore, investigation of the wear properties under a vacuum environment is as indispensable as wear properties under an atmosphere. However, the wear performance of this alloy cannot meet the expectations. This paper reports the investigation of the obtained wear properties of Al7075-T6 alloy after plasma nitriding in ambient air and vacuum environments. The surface characterization and phase analysis of the formed AlN layers are determined by scanning electron microscope, energy dispersive X-ray spectrometer, 3D optical profilometer and X-ray diffractometer. The hardness of the nitride layer is established using Vickers micro-hardness tester. The wear performance of the untreated and nitride sample is investigated under 1N constant load at ambient air and vacuum environment. As a result of wear tests, the best wear performance of both conditions has been obtained from nitrided samples. The AlN layer (0.19) is observed to notably reduced the coefficient of friction of the substrate (0.60) under ambient air. Besides, it is observed that the nitride layer is better in ambient air (0.00010 mm(3)/Nm) than in vacuum environment (0.00087 mm(3)/Nm) in term of wear rate. In fact, the wear track on the nitrided sample is very thin under ambient air, and nearly imperceptible.Öğe Açık ve kapalı alanlarda elektrik kaçak tespiti için iş ayakkabısı tasarımı ve prototip üretimi(Bakırçay Üniversitesi Lisansüstü Eğitim Enstitüsü, 2021) Yoldaş, Savaş; Gök, Kadir; Selçuk, Akil BirkanÇalışma ortamlarında, İş Sağlığı ve Güvenliği kanununa uyulması ve uygulanması son derece önem arz eder. Bu kapsamda, yapılacak her türlü çalışmalar ve iyileştirmeler iş kazalarının önemli ölçüde azalmasını sağlayacaktır. Dünyada, her geçen gün üretime olan talepler artmaktadır. Bu talepleri yerine getiren kahramanlar elbette çalışanlardır. Çalışanlar iş kazalarına karşı korunmalıdır. İş yerlerinde, İş Sağlığı ve Güvenliğini sağlayacak kişisel koruyucu donanımların ve iş ekipmanlarının bulundurulması ve kullandırılması gereklidir. Bu tür iş ekipmanlarında, iş güvenliğini sağlayacak mühendislik uygulamaların yapılması ve geliştirilmesi gereklidir. Elektrik kaynaklı iş kazaları ağır yaralanmalara hatta ölümlere neden olabilmektedir. Bu çalışmanın amacı, açık veya kapalı alanlarda bulunan alternatif gerilim (AC) yüklü kabloların varlığının ve/veya kaçak elektrik akımlarında (AC kaynaklı) çalışanı uyarmaktır. Prototip; sesli, görsel ve titreşimli olarak uyarı vermektedir. Çalışma ortamında olası alternatif gerilim ve kaçaklarında çalışanın sesli ve görsel ikaz alamaması durumunda ayakkabın üst iç kısmına yerleştirilen motor sayesinde titreşim sinyalleri çalışanın ayak üst kısmına iletir. Sisteme eklenen güneş paneli sayesinde, güneşli ortamlarda ek enerji ihtiyacı sağlanmaktadır. Sistemin ayakkabıdan ayrılabilir özelliği sayesinde, iş kıyafetlerinde ve el ile kontrollerde kullanılabilir. İş ayakkabısının bu özelliği geliştirilebilir olmasıdır.Öğe Development of a new model for determine of cutting parameters in metal drilling processes(Springer Heidelberg, 2020) Turkes, Erol; Erdem, Mehmet; Gök, Kadir; Gök, ArifMetal drilling and cutting processes are used commonly in many areas of the industry. When these processes investigated analytically, it is seen that they have a very complicated structure. This complicated structure can find easy solutions with finite element-based simulation tools. In metal removal operations, it is very difficult to calculate the cutting parameters such as cutting tool stresses, residual stresses, cutting tool-chip interface temperature and shear angle both experimentally and analytically. But, these operations could be easily calculated by computer-supported simulation tools. In these types of numeric simulations, using finite element method, it is needed to identify clearly the friction, material model load and limiting conditions. In this paper, the cutting parameters as cutting and thrust power, heat transfer coefficient and friction coefficient at chip-tool interface which is needed to find the temperature distribution on drilling bit and workpiece material were calculated using analytic models.Öğe Comparison of two different bowel anastomosis types using finite volume method(Taylor & Francis Ltd, 2020) Pirhan, Yavuz; Gök, Kadir; Gök, ArifThe purpose of this study was to compare side-to-side and functional end-to-end anastomosis techniques that are commonly used in bowel surgery. Considering the dimensions of these two different anastomosis models, SolidWorks program was used for 3 D studies. Intra-intestinal flow analyzes were performed based on the finite volume method using Ansys Fluent, a computational fluid Dynamics (CFD) program. The flow velocity, pressure, turbulent knetic energy, turbulence vortex distribution, vortex viscosity and wall shear stresses for each model were calculated in results of the analysis for the side-to-side and functional end-to-end anastomosis technique. Due to the geometrical structure of the functional end - to - end anastomosis model, turbulence and hence the vortex formation is less than the side - to - side anastomosis technique. Because intersect area of bowels has wider in functional end - to - end anastomosis model, flow become easier than other. In surgical practice, functional end-to-end anastomosis is preferred over side-to-side anastomosis because of the low probability of leakage. It can be noted that the functional end - to - end anastomosis technique will be safer because of less turbulence, based on the data of fluid flow velocities, pressure, turbulent knetic energy, turbulence vortex distribution, vortex viscosity and wall shear stresses in the anastomosis.Öğe Evaluation of screwing configurations in conventional plating of femoral shaft fractures using finite element analysis(World Scientific, 2021) Öztepe, Burkay; Gök, Kadir; Erdoğan, Yasin; İnal, Sermet; Gök, ArifSeveral fractures that occur in the human body depend on trauma or as a result of hormonal and bone fatigue. Fracture types that take place out of the neck area of the femoral bone are named femoral shaft fractures. Femoral shaft fractures are frequent conditions in orthopedics. Conventional plating method is a method that necessitates the fixation of the contact surface by contacting the epiphyses used in the treatment of such fractures. This method is known to be efficent in speeding up the healing process by reducing the movement between the epiphyses. In this study, femur models which are plated in various forms with fractures were analyzed with computer-aided finite element software and stresses on bone surfaces and fracture surfaces were determined. It is aimed to determine the best result by examining the relationship between the inputs such as the number of screws used during plating, the fixation area and material selection and the outputs obtained by finding the stresses on the bone surface and stresses on the broken surfaces. © 2021 World Scientific Publishing Company.Öğe Histopathological and biomechanical investigation of the effect of momordica charantia on fracture healing, kidney, and liver: an experimental rat model(World Scientific Publ Co Pte Ltd, 2021) Özturk, Burhan; İnal, Sermet; Dülgeroğlu, Turan Cihan; Üzümcügil, Alaaddin Oktar; Deger, Ayşenur; Kuyubasi, Sabit Numan; Gök, KadirMomordica charantia (MC) is a plant belonging to the family Cucurbitaceae. MC has antidiabetic, antibacterial, antioxidant, antimutagenic, antiulcerative, antiinflammatory and antilipidemic effects. However, information on the effect of MC on fracture union is lacking. This study aimed to examine the effect of MC on fracture union histopathologically and biomechanically. A total of 42 male Wistar-Albino rats were randomly divided into 3 groups, 14 in each group. A diaphyseal fracture was created on the right tibia of all rats. All fractures were fixed with a Kirschner (K) wire. The rats in Group I did not undergo any further procedures (Control group). Group II rats were treated with 0.9% saline oral gavage at a dose of 500 mu L/day for 28 days [Saline (S) group]. The rats in Group III were given 300mg/kg MC extract per day, dissolved in 500 mu L 0.9% saline by oral gavage for 28 days [MC (Extract) group]. After 28 days, all rats were sacrificed. Each group was randomly divided into two subgroups. The histopathological examination was performed on the right tibia of rats in the first subgroup and the biomechanical examination in the second subgroup. The kidneys and livers of all rats were evaluated histopathologically. Fracture union was significantly better in the Extract group compared with the Control and S groups histopathologically. The fracture inflammation values were lower in the Extract group than in the other groups. No statistically significant difference was found between the groups in terms of possible side effects to kidneys and livers. In terms of biomechanics, fracture union was significantly better in the Extract group compared with the Control and S groups except yield displacement values. MC had a positive effect on fracture union histopathologically and biomechanically.Öğe Development of software to calculate of friction process parameters used in friction drilling process(2021) Gök, Kadir; Erdem, Mehmet; Gök, Arif; Bilgin, Mehmet BurakFriction drilling processes are used frequently in hot forming operations. This process is similar todrilling processes but it has not chips and used to join of thin-walled metal components. The createdfrictional heat plasticizes the material and allows the punch type tool to enter the material surface,thus creating additional heat by friction. By the feeding tool pressure, it is advancing into the materialsurface while creating a hole. An analytic model and software was developed to calculate the frictiondrilling process parameters as torque and axial power, heat transfer coefficient for friction drillingprocess in this study.Öğe İnsan femur kemiğinde burkulma davranışının sonlu elemanlar yöntemiyle incelenmesi(2020) Gök, Kadir; Gök, ArifBu çalışmada eksenel yükleme altında insan femur modeli üzerinde burkulma etkisinin biyomekanikdavranışın sonlu elemanlar metodu (SEM) kullanılarak analiz edilmiştir. İnsan femurunun 3 boyutlu(3D) modeli Geomagic ve SolidWorks programı kullanılarak oluşturulmuştur. Sonlu eleman analizleriise Ansys Workbench 18.2 programında gerçekleştirilmiştir. 3D insan femur modeline eksenelyükleme sonucu oluşan deformasyonlar ve gerilmeler basma ve flambaj olarak ayrı ayrı incelenmiştir.Yapısal analiz soncunda femur kemiğinde oluşan deformasyon 2.06 mm iken, burkulma analizisonucunda femur kemiğinde oluşan deformasyon ise 1.29 mm olarak hesaplanmıştır. Bu durum insankemiğinde eksenel yük altında flambaj etkisinin düşük olduğunu göstermektedir. Bu durumun femurkemiğinin anatomik yapısı ile ilişkili olduğu düşünülmektedir. Ayrıca basma etkisindeki gerilmedeğeri 15.71 MPa iken, flambaj etkisindeki kritik burkulma gerilmesi ise 8.30 MPa olarakheaplanmıştır. Teorik olarak kritik yük (??????) 2102.21 N olarak hesap edilirken, SEA’ de ise 2164.54 Nolarak hesaplanmıştır.Öğe Investigation using finite element analysis of effect on crater geometry of different abrasive types in abrasive water jet machining(World Scientific Publ Co Pte Ltd, 2021) Gök, KadirToday, manufacturing methods are classified into two groups as conventional and non- conventional manufacturing methods. While turning, milling, and drilling are among the conventional manufacturing methods, processes such as laser, plasma, electro erosion, ultrasonic machining and water jet machining are among non-conventional, namely modern manufacturing methods. The cutting tool does not used in modern manufacturing methods. This situation is an advantage. There are some uncertainties on the machining performance of abrasive types, apart from the superior properties of the method. In this study, the effect of different abrasive types on machining performance in abrasive water jet machining (AWJM) was investigated by using computer aided finite element analysis.Öğe Computer-aided simulation using finite element analysis of protect against to coronavirus (COVID-19) of custom-made new mask design(Springer India, 2021) Gök, Kadir; Selçuk, Akil Birkan; Gök, ArifThe Covid-19 virus has been recognized by the World Health Organization to be creating Pandemic worldwide. It has been determined that the virus spreads very quickly and has a fatal risk in people with chronic disease. As the virus vaccine and medications to be used for treatment are not fully developed, alternative ways to protect human being from the virus are being investigated. In this study, a custom-made mask design was developed to prevent infection of the virus and computer-aided simulations were performed. Three-dimensional model of the custom-made face mask was created with the SolidWorks software. The analyses were performed using Ansys Workbench Explicit Dynamics module. The load, boundary conditions and material were defined in the Ansys Workbench. As a result of the simulations, it has been determined that custom-made designed masks have a much lower risk of virus infection than conventional masks.
