Makine Mühendisliği Bölümü Koleksiyonu

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https://hdl.handle.net/20.500.12939/76

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Development and Evaluation of Drone Based Spraying System for Precision Agriculture Application
(International Information and Engineering Technology Association, 2025) Yousfi, Ayoub El; Alawi, Yaser
Unmanned aerial vehicles (UAVs), also known as drones, are increasingly used for various purposes such as photography, surveillance, mapping, inspection, and agriculture. This research specifically focuses on agricultural drones, which have the potential to address challenges encountered by farmers, ultimately positively affecting crop yields. Their ability to apply pesticides accurately and autonomously, without direct human involvement, is crucial for modern farming practices. This study aims to design and simulate a quadcopter specifically tailored for pesticide spraying. The design process involves careful selection of components and simulation using both SolidWorks and MATLAB Simulink. In SolidWorks, design the frame and components, while MATLAB Simulink is used to simulate trajectory tracking using PID controllers. The key finding is the integration of a multispectral camera to capture images and analyze data using Pix4Dfields and Agremo software. This analysis helps pinpoint specific areas requiring treatment, thereby minimizing pesticide and water usage while maximizing profitability. By targeting exact locations in the field based on data analysis, this approach improves efficiency. The research focuses on evaluating the quadcopter’s performance and trajectory accuracy, offering valuable insights into its potential agricultural impact, and assisting farmers in enhancing their profits through improved spraying techniques and resource management.
Experimental study of nucleate pool boiling with water in atmospheric pressure
(Serbian Society of Heat Transfer Engineers, 2024) Ağma, Onur; Yıldız, Sebiha
This study experimentally investigated nucleate pool boiling heat transfer for a polished copper surface and water fluid couple under atmospheric pressure. The results were compared with the correlations in the literature. The experimental results were compared with the surface-liquid correlation constants Rohsenow, Pioro, Vachon, Griffith, and Das used for the temperature exceedance values. When the results of Griffith’s correlation constant were compared with the experimental values, it was seen that it was the most appropriate correlation compared to other correlations, with a minimum and maximum error of 0.4–12%. In addition, Forster-Zuber, Pioro, Kutateladze old, Kutateladze new, Kruzhilin, and Cooper correlations were compared with experimental results regarding the heat transfer coefficient. Compared with the correlation proposed by Pioro for the heat transfer coefficient, it was calculated as the most suitable correlation with a minimum and maximum difference of 0.2–8%.
Simulation and investigation of bioethanol production considering energetic and economic considerations
(2023) Alaiwi, Yaser; Abed, Azher M.; Smaisim, Ghassan Fadhil; Aly, Mohamed Aly Saad; Hadrawi, Salema K.; Morovati, Reza
Today, the use of alternative fuels that have plant origin has attracted the attention of most countries because these fuels emit less pollution. In this research, bioethanol production has been evaluated considering solar energy sources. In the present study, the possibility of developing net-zero energy concepts in a bioethanol production plant as one of the most consumed energy industries in the field of bio-systems of the country from a technical and economic perspective was investigated. The purpose of this research is to model the bioethanol production plant with the aim of achieving zero net energy using a photovoltaic system. In addition, technical and economic analyses have been used in different approaches for a more detailed investigation. According to the modeling done, in the zero net energy approach, the results showed that the maximum production of electrical energy by the photovoltaic cell is 76.6 GWh/y. For this approach, the return on investment is 10.7 years. The area required to install photovoltaic modules in this approach is very large and equal to 88 334 m2.
İstanbul Boğazı’ndaki deniz kazalarının seyir emniyeti perspektifinde incelenmesi: İstanbulmaks gemi tipi önerisi
(2022) Kodak, Gizem; Kara, Gökhan; Yıldız, Murat; Şalcı, Aydın
Bu çalışmada, İstanbul Boğazı’nda 10 yıllık periyotta meydana gelen deniz kazaları gemi kökenli risk faktörleri açısından ele alınmış ve elde edilen veriler, R – Studio program dili kullanılarak frekans analizine tabi tutulmuştur. Bu kapsamda T.C. Ulaştırma ve Altyapı Bakanlığı Ana Arama Kurtarma Koordinasyon Merkezi’nden temin edilen kaza verileri, MMSI numaraları üzerinden Türk Loydu veri tabanından gemi bilgileri ile eşleştirilmiştir. Böylelikle, çalışma kapsamında kullanılacak gemi kökenli risk faktörleri belirlenmiş ve 10 farklı kriter analizlere dahil edilmiştir. Bunlar, gemi boyu, gemi genişliği, gemi su çekimi, gemi yaşı, gemi deadweight tonajı, manevra yarıçapı, dönme noktası, L/B oranı, B/T oranı ve pervane sayısıdır. Verinin mekânsal olarak filtrelenmesi ve gemi kökenli kaza nedenlerinin sınıflandırılmasıyla veri seti oluşturma süreci tamamlanmış ve değişkenler Büyük Sayılar Yasası perspektifinde frekans analizine tabi tutulmuştur. Elde edilen sonuçlarla, İstanbul Boğazı’ndan en emniyetli şekilde geçiş yapabilecek optimum karakteristikler belirlenmiştir.
Turbulent fluid flow and heat transfer enhancement using novel Vortex Generator
(Penerbit Akademia Baru, 2022) Shlash, Bassam Amer Abdulameer; Koç, İbrahim
One of several effective methods for improving heat transfer in heat exchangers is the use of vortex generators in channels. The flow of fluid through a channel with a vortex generator is disrupted by the development of recirculation zoneson the step wall, which improves fluid mixing and heat transmission. The current work investigates the flow and heat transfer of turbulent fluid flow through channels with various vortex generator designs mathematically (triangular, half-circle, and quarter circle). The finite volume method (FVM) is used to discretize and solve the continuity, momentum, and energy equations. The SIMPLE algorithm approach is used to connect the pressure and velocity fields within the domain. The effect of geometrical factors such as step height (2, 3, 4, 5, and 6 mm) on the flow and heat fields is demonstrated and analyzed, as is the effect of Reynolds number. As the step height increases, so do the surface Nusselt number and skin friction coefficient, which peak at 4 mm. According to the findings, as Re increases, so does the average Nusselt number. The quarter circle vortex generator has the best thermal-hydraulic performance at a 4 mm amplitude height, followed by the triangle vortex generator. The simulation results are consistent with those found in the literature.
Finite element simulations for the sustainable CFRP retrofitted hollow square columns
(EJSE INT LTD, 2022) Falah, M. W.; Al-Khafaji, Z. S.; Yaseen, R.; Yousif, D. F.; Hamza, K. A.; Radhi, S. S.
This article describes the finite element analysis of concrete columns with a hollow square reinforced which restricted with a square Carbon-Fiber-Reinforced polymer (CFRP) tube. In this study, about sixteen square hollow core columns were investigated. These columns were classified into four sets. The set number one was the reference set which involved four unconfined reinforced columns with traditional steel helices and longitudinal steel bars. The columns of the 2nd category have a similar configuration as the set number one except that these columns were restricted outwardly by the CFRP tube. The columns of the set number were restricted outwardly by a CFRP tube and restricted inwardly by a steel tube. Finally, the columns of the 4th category do not have a steel reinforcement where they produced with only an outer CFRP tube and an inner steel tube. These columns were exposed to various loading conditions: concentric, eccentric (22 and 44) mm, and four bendings' points. It was investigated that the CFRP tube confinement faintly improved the columns' strength. Moreover, the use of a steel tube as inner confinement in the columns with a hollow section led to improve the structural performance and ductility.
Sustainable heating system by infrared radiators
(Research and Development Academy, 2022) Radhi, Sabaa S.; Al-Khafaji, Zainab S.; Falah, Mayadah W.
Maintaining the optimum temperature in the living quarters is the key to a comfortable stay. Due to the lack of a central heating system or in the event of its insufficiency, they resort to the installation of additional heat sources. There is a wide range of devices on the market with different operating principles, hence the difficulty of which is better - a convector or infrared heater. A comparative analysis of devices will help you make the right choice. Asking the question of which is better a convection heater or an infrared heater, one must decide on its role in heating the house. It is better to use them as additional equipment with an existing heating system. One of the effective sources of additional heating are infrared radiators. Its principle of operation is based on infrared radiation, which provides a quick and qualitative increase in temperature in any part of your apartment. Today, more and more people prefer infrared radiators. From the usual electric convector, they differ in that they heat not the air in the room, but hard surfaces (floors, walls) and objects, and these, in turn, leak heat into the surrounding space. So, the entire room is heated up unnoticeably.
In silico evaluation of lattice designs for additively manufactured total hip implants
(Computers in Biology and Medicine, 2022)
Additive manufacturing restructures the fabrication of custom medical implants and transforms the design, topology optimization, and material selection perspectives in biomechanical applications. Additionally, it facilitated the design and fabrication of patient-oriented hip implants. Selection of proper lattice type is critical in additive manufacturing of hip implants. The lattice types reduce the implant mass and, due to higher stress distribution and deformations as compared to the rigid implants, it brings down the stress shielding issues. This study introduces a rigid shell structure and infill lattice hip implant. Additionally, the effect of various lattice unit cell thickness (0.2–1 mm) and elemental size (2.5–5 mm) while applying 2300 N axial force is explored numerically. A cubic structure with two rigid surfaces on the top and bottom is outlined to separate the effect of the hip implant cross-sectional area variations. The stress distribution and deformation characteristics are validated with the hip implant design. The Finite Element Analysis (FEA) demonstrated that the Weaire-Phelan lattice structure exhibits the least stress and deformation among the other types at various design parameters. Additionally, the same methodology is applied to three biocompatible hip implant materials as Ti–6Al–4V, TA15 (Ti–6Al–2Zr–1Mo–1V), and CoCr28Mo6. Finally, the effect of the unit cell thickness and size on the implant's mass reduction considering the lattice's safety factor is investigated for the mentioned materials. The selection of a Weaire–Phelan lattice with the optimized safety factor and mass reduction is represented considering all the results. The optimized parameters for Titanium-based alloys are approximately 3.5 mm unit cell size with 0.6 mm beam thickness. However, the CoCr Mo-based alloy requires a thicker beam size (about 0.8 mm) due to lower safety factors.
Effect of polyurea coating on the ductility of aluminum foam
(Materials Today Communications, 2022) Bijanzad, Armin; Lazoğlu, İsmail; Ensarioğlu, Cihat; Çakır, Mustafa Cemal
The closed-cell metal foams are utilized in various industrial applications due to their impact and energy ab- sorption capacity, noise cancelation, and lightweight properties. Additionally, the manufacturing methods of stochastic foams with blowing agents or inert gas injection are well known. However, the poor mechanical strength and high brittleness are restricting the application of these materials. A method of increasing the ductility, plastic deformation, and fracture toughness of these materials is the integration of elastomer coating. Polyurea is widely used in applications where water-proofing and high ductility are aimed. In this study, two types of polyurea coatings as MS950 and MS955 are sprayed over the aluminum foam with three densities as 0.508, 0.557, and 0.624 g/cm3 to evaluate the effect of coating on the ductility and fracture toughness of samples considering the tensile behavior and 4 densities as 0.508, 0.538, 0.557, and 0.624 g/cm3 for the flexural bending test. The MS955 polyurea coating elevated the ultimate tensile strength and elasticity modulus of all specimens with a maximum of 239% and a minimum of 70%. However, the MS950 coating did not result in a significant rise in tensile strength. The main advantage of the MS950 coating is in the amount of strain increment with 374% in maximum and 181% in minimum resulting in higher ductility and fracture toughness. Additionally, the bending characteristics of MS950 coating demonstrate a drastic increase in both load and strain which recommend the usage of this coating in bending and impact applications. Finally, an analytical evaluation of the coated and uncoated specimens in the elastic region and the elastoplastic region is provided using linear and power-law interpolation. In tensile tests, the MS955 coating resulted in higher elasticity modulus and fracture toughness. However, in bending applications, the MS950 coating demonstrated higher load strength with elevated ductility
Effect of reinforcing materials on mechanical properties of composite material using Taguchi method
(Journal of Physics: Conference Series, 2021) Owaid, Anmar Abdulazeez; Kaygusuz, Hakan; Mohammed, Farag Mahel
The mechanical properties play an important role in the selection of suitable material in the manufacturing of boats. In this paper, the effect of glass fiber orientations and the fillers weight fraction on the mechanical properties of un saturated polyester composite material were studied. The glass fibers were used with (0/0, 0/90, 45/45) angles. The carbon filler used with (2.5%, 5%, 7.5%), while the aluminium oxide nano be used with (0%, 1%, 3%) weight fraction respectively. The standard Taguchi’s array L9 (33 ) was used. The signal to noise ratio and analysis of variance were introduced to analyze and estimate the optimal combination parameters. The results show that the mechanical properties improved with using the reinforcements. The glass fibers orientations angle presents the most parameter effect than the other parameters on the modulus of elasticity, tensile strength and impact strength with a contribution of 81.8%, 83.39% and 96.75% respectively. Followed by carbon and aluminium oxide nano. The optimum parameter with their levels for the highest modulus of elasticity was obtained at (0/90 fiber orientation, 5% carbon and 0% nano aluminium oxide). While the highest tensile strength and impact strength present with using (0/0 fiber orientation and 5% carbon). The experimental and expected results are very close, with an error ratio not exceeding 5%.
The effect of different number of layers and fiber distribution on the performance of composite laminates
(Journal of Physics: Conference Series, 2021) Mulaan, Najjm Abdalla; Mahmood, Amjed Saleh; Baştürk, Süleyman
Fiber-reinforced composites are widely used in world industries such as transportation vehicles, sports tools, space crafts, and more. This research investigates the influence of the number of layers and fiber distribution on the mechanical properties of woven fiber-reinforced composites by changing the number of layers or the manufacturing process. Hand lay-up and infusion processes are used to manufacture the composite plates. Three mechanical tests are conducted for all composite plates, such as Interlaminar shear stress (ILSS), ultimate tensile strength (UTS), and ultimate flexural strength (UFS). Furthermore, analyzing the microstructure of the laminates is conducted to evaluate fractal dimension (FD). It is observed that the distribution of the fibers measured by FD had an effective role in improving the mechanical properties. Also, the use of vacuum molds had an additional role in improving the mechanical properties. One could conclude that all the mechanical properties have proportional relationships with FD.
Heat-assisted machining of superalloys: A review
(Springer Nature, 2021) Bijanzid, Armin; Munir, Talha; Abdulhamid, Farouk
Superalloys are vastly used in the aerospace industry due to their alluring properties such as maintaining their strength at high-temperature applications. Nevertheless, manufacturing these raw materials to the desired geometrical shapes is one of the main challenges of the subtractive manufacturing industry and they are categorized as hard-to-machine materials. Several approaches such as high-speed machining (HSM), cryogenic cooling, minimum quantity lubrication (MQL), and heat-assisted machining (HAM) are introduced to tackle this matter. HAM is a technique that introduces external heat sources to the workpiece (pre-heating or real-time heating methods) to increase the ductility of the superalloy and therefore reduce the yield and shear strength of the workpiece. By this means, the machining parameters demonstrate an improvement compared to conventional machining. This review article focuses on the research approaches conducted to evaluate the efect of the various heat source applications (gas fame, induction, laser, and plasma) on the material properties and the machinability of the superalloys. Additionally, the heating methodology and heat assistance impact on cutting parameters (forces, tool life, surface integrity, and chip morphology) are outlined. Finally, a comparison of the heat source efciency and the economics of the various heat applications is performed.
Bazalt/Ni, W/Ni, ve B/Ni fonksiyonel derecelendirilmiş kompozit plâkaların dinamik basınç yükü altındaki davranışlarının analizi
(2019) Baştürk, Süleyman
Fonksiyonel Derecelendirilmiş Malzemeler (FDM) diğer ileri kompozit malzemelere göre günümüzde daha önemli bir yer tutmaktadır. Bu çalışmada, yüksek sıcaklık ve basınç uygulamalarında kullanılan bazalt, tungsten (W) ve bor (B) malzemeleri ile nikel (Ni) kullanılarak oluşturulan fonksiyonel derecelendirilmiş plâkaların ani basınç yükleri altındaki lineer olmayan dinamik davranışları modellenmiş ve detaylı analizleri yapılmıştır. Fonksiyonel derecelendirilmiş malzemelerin modellenmesi için Homojen Katmanlı Model (HKM) ve Sürekli Model (SM) yaklaşımları kullanılmıştır. Ani basınç yükü olarak ise Üstel Basınç Yükü Modeli uygulanmıştır. Yapılan detaylı analizler sonucunda W/Ni kompozit plâkaların daha düşük değerde genlik ve titreşim frekansı davranışı gösterdiği, bunun yanında farklı modelleme yöntemleri ve n parametresinin farklı değerlerinin de fonksiyonel derecelendirilmiş kompozit plâkaların dinamik davranışında etkili olduğu olduğu görülmüştür.
Real-time gait classification for persuasive smartphone apps: Structuring the literature and pushing the limits
(2013) Schneider, Oliver; MacLean, Karon E.; Altun, Kerem; Karuei, Idin; Wu, Michael Ming-An
Persuasive technology is now mobile and context-aware. Intelligent analysis of accelerometer signals in smartphones and other specialized devices has recently been used to classify activity (e.g., distinguishing walking from cycling) to encourage physical activity, sustainable transport, and other social goals. Unfortunately, results vary drastically due to differences in methodology and problem domain. The present report begins by structuring a survey of current work within a new framework, which highlights comparable characteristics between studies; this provided a tool by which we and others can understand the current state-of-the art and guide research towards existing gaps. We then present a new user study, positioned in an identified gap, that pushes limits of current success with a challenging problem: the real-time classification of 15 similar and novel gaits suitable for several persuasive application areas, focused on the growing phenomenon of exercise games. We achieve a mean correct classification rate of 78.1% of all 15 gaits with a minimal amount of personalized training of the classifier for each participant when carried in any of 6 different carrying locations (not known a priori). When narrowed to a subset of four gaits and one location that is known, this improves to means of 92.2% with and 87.2% without personalization. Finally, we group our findings into design guidelines and quantify variation in accuracy when an algorithm is trained for a known location and participant. Copyright © 2013 ACM.
Lamination effect on flow rates through composite liners
(Deutsche Gesellschaft fur Geotechnik e.V., 2014) Güler, Erol; Özhan, Hakkı; Cengiz, Cihan
In this study, the hydraulic conductivity characteristics of laminated versus unlaminated composite liner systems were compared. For this purpose, a flexible-wall permeameter was used and hydraulic conductivity tests were performed. A 6 and 0.75 mm diameter hole in the middle of the laminated geomembrane (GM) was created on the geocomposite produced by a GM laminated to a geosynthetic clay liner (GCL). The other geocomposite was produced by simply placing the same GM on the same GCL without lamination. In order to compare the effect of hydraulic heads and effective stress, the GCLs were tested under hydraulic heads of 0.75 m and 1.5 m and effective stresses of 35 kPa, 140 kPa and 280 kPa. According to the results, lamination did not have a significant effect on the hydraulic properties of the geocomposites in the laboratory scale. Increasing effective stress and decreasing hydraulic head caused little decrease in flux of the geocomposites. Defect size also did not have a significant effect on hydraulic conductivity.
Hierarchical porous carbide-derived carbons for the removal of cytokines from blood plasma
(Wiley-Blackwell, 2012) Presser, Volker; Yeon, Sun-Hwa; Vakıfahmetoğlu, Cekdar; Howell, Carol A.; Sandeman, Susan R.; Colombo, Paolo; Gogotsi, Yury
Carbide-derived carbons with hierarchical porosity derived from a polymer precursor can be used for the extracorporeal removal of pro- and anti-inflammatory cytokines. The removal rates scale with the surface area of pores large enough to accommodate the protein molecules and this method has potential for efficacious treatment of sepsis, one of the major challenges in healthcare. Further information can be found in the Communication by S. Mikhalovsky, Y. Gogotsi, and co-workers on page 796.
Solvothermal synthesis of acmite conversion coatings on steel
(Wiley, 2013) Whalen, Terence; VanSaders, Bryan; Vakıfahmetoglu, Cekdar; Mughal, Asad; Zlotnikov, Eugene; Cho, Seung-Beom; Riman, Richard E.
Acmite (NaFeSi2O6) films were formed on steel coupons via solvothermal reaction of silica, sodium hydroxide, and 1, 4-butanediol in an autoclave under autogenous pressure. Systematic variation in processing variables led to homogenous coatings comprised of pinacoidal acmite grains with an average grain size of similar to 33m. The coatings were produced on the steel coupons from reactant conditions of 0.635m SiO2, 2.546m NaOH, and 3.087m 1,4-butanediol for 72h at 240 degrees C.
Polysiloxane- derived ceramics containing nanowires with catalytically active tips
(Wiley-Blackwell, 2014) Adam, Michael; Vakıfahmetoğlu, Cekdar; Colombo, Paolo; Wilhelm, Michaela; Grathwohl, Georg
By direct foaming of a Pt-containing polysiloxane precursor, macroporous ceramics were generated by pyrolysis at 1400 degrees C under nitrogen or argon. The growth of nanowires was induced via a vapor-liquid-solid mechanism in which the Pt particles acted as deposition site for the decomposition gases released upon pyrolyzing the preceramic polymer. SEM, HR-SEM, TEM/EDX, and XRD investigations revealed that pyrolysis under argon atmosphere leads to short SiC nanowires of only a few micrometers length and under nitrogen atmosphere Si3N4 nanowires evolved, with length of several 10m. In both cases the tips of the nanowires mainly consisted of PtSi. In contrast to samples pyrolyzed at 600 degrees C, the components after higher temperature pyrolysis showed moderate-specific surface areas of 55-67m(2)/g. In CO oxidation experiments, a good catalytic activity was found for the Pt silicide particles, suggesting that despite their relatively large size, their location at the tips of the nanowires affords them good reactivity.
Zeolite decorated highly porous acicular calcium silicate ceramics
(Elsevier Sci Ltd, 2014) Vakıfahmetoğlu, Cekdar
Macrocellular calcium silicate (wollastonite) ceramic foams possessing similar to 86 vol% total porosity were produced from commercial calcium silicate hydrate (xonotlite) nano-size acicular crystals and poly-methyl-methacrylate microbeads (PMMA) (used as sacrificial pore formers). Open cell wollastonite foams had a bi-modal pore size distribution with major modes located similar to 100 nm due to interparticle porosity and similar to 100 mu m due to the sacrificial pore former. These macrocellular ceramics were then used as a scaffold for MFI type zeolite (silicalite-1) synthesis. Monolayer coffin shaped zeolite crystals (similar to 3 mu m size, measured from the c-axis and similar to 300 nm thickness) were observed with almost full coverage on the inner macro-cell walls. The specific surface area of the components increased from 9.6 m(2)/g to 108.2 m(2)/g via zeolite functionalization, leading to components possessing multiscale porosity. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
SiC foams decorated with SnO2 nanostructures for room temperature gas sensing
(Wiley, 2014) Karakuscu, Aylin; Ponzoni, Andrea; Comini, Elisabetta; Sberveglieri, Giorgio; Vakıfahmetoglu, Cekdar
Cell walls of the commercial silicon carbide (SiC)-based foams were decorated by one-dimensional tin dioxide (SnO2) nanostructures. Thermal evaporation of SnO2 powder with the assistance of a Au catalyst in inert atmosphere caused the formation of SnO2 nanobelts on the pore surfaces. The room temperature (RT) ammonia (NH3) and nitrogen dioxide (NO2) gas sensing behaviors were investigated systematically in both dry and humid air atmosphere with/without UV activation. The results were compared to those for bare SnO2 and SiC. It was shown that SiC/SnO2 composite was efficient to detect low concentration of NH3 (10-50 ppm) and NO2 (1-5 ppm) under humid air and UV activation at RT.

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