Makine Mühendisliği Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/263

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Citation - Scopus: 1
A Droplet Based Multi-Drug Screening System Controlled With Electrostatic Microvalves
(Chemical and Biological Microsystems Society, 2012) Yildirim, E.; Yıldırım, Ender; Özgür, E.; Külah, H.; 31835; Makine Mühendisliği
This paper presents a droplet-based drug effect analysis system utilizing electrostatically-actuated normallyclosed microvalves to screen the effect of multiple drugs on a single type of cell. Proposed system minimizes the need for off-chip equipment by utilizing parylene based electrostatic microvalves. Prototypes of the system were fabricated and tested using colored DI water and 3 μm diameter micro beads, emulating drugs and cells respectively. During the tests, micro beads could be successfully entrapped in 137 pl droplets. Tests carried out with yeast cells also yielded successful encapsulation of the cells. It was shown that, switching between the drugs could be achieved by applying 200 V dc to operate the microvalves.
Citation - WoS: 12
Citation - Scopus: 13
A Reconfigurable Microfluidic Transmitarray Unit Cell
(Ieee, 2013) Erdil, Emre; Yıldırım, Ender; Topalli, Kagan; Zorlu, Ozge; Toral, Taylan; Yildirim, Ender; Kulah, Haluk; Civi, Ozlem Aydin; 31835); Makine Mühendisliği
This paper presents a novel microfluidics based approach to develop a reconfigurable circularly polarized transmitarray unit cell. The unit cell comprises double layer nested split ring slots formed as microfluidic channels that can be filled by fluids. Split regions in the slots are realized by injecting liquid metal into the channels. Beam steering is obtained by implementing rotational phase shifting via manipulating the liquid metal in the slots. X-band unit cell prototypes are fabricated on glass substrate carrying a patterned metal film, and the slot channels are formed by Polydimethylsiloxane (PDMS) using soft lithography techniques.
Citation - Scopus: 1
A Simple Way for Estimating Mechanical Properties From Stress-Strain Diagram Using Matlab and Mathematica
(Institute of Electrical and Electronics Engineers Inc., 2019) Yılmaz, Emre; Yilmaz, E.; Yavuz, S.; Yavuz, Samet; 237938; Malzeme Bilimi ve Mühendisliği; Makine Mühendisliği
In this paper, mechanical properties of materials, e.g. ultimate tensile strength, yield stress, elastic modulus, ductility, resilience, toughness, etc., are calculated using MATLAB and Mathematica programming language and stress-strain data of any alloy. © 2019 IEEE.
Citation - Scopus: 0
A Study of the Structural and Mechanical Characterization of Hybrid Nanocomposite Material
(Trans Tech Publications Ltd, 2017) Mahmoud, A.K.; Demiral, Murat; Al-Nassar, S.I.; Demiral, M.; Kadhim, H.M.; Makine Mühendisliği
This work is devoted on the synthesized new hybrid nanocomposite materials by using mechanical stirring method through a combination of different types of material; epoxy based matrix and nanofiller (TiO2 nanoparticles) as a reinforcement material. In additional this paper studies the effect of TiO2 nanoparticles with percentage 2-8 wt% added to epoxy based matrix on the mechanical properties (tensile properties and hardness property). The results showed that the tensile strength of nanocomposite material increased gradually by increasing the weight percentage of TiO2 nanoparticles from 2 wt % to 8 wt % TiO2, while the best tensile strength was at 8 wt % TiO2. The maximum value of tensile strength was 270% higher than the neat epoxy matrix. The hardness increase gradually with increasing percentage of TiO2 nanoparticles from 2wt% TiO2 up to 8wt% TiO2, the maximum value of hardness was at 8wt % TiO2, so the hardness of nanocomposite is around 86% higher than the neat epoxy matrix. © 2017 Trans Tech Publications, Switzerland.
Citation - Scopus: 1
An Electrostatically Actuated Parylene Microvalve for Lab-On-A-Chip Applications
(2011) Yildirim, E.; Yıldırım, Ender; Kulah, H.; Arikan, M.A.S.; 31835; Makine Mühendisliği
This paper presents a novel electrostatic microvalve to control in-plane flow on parylene based lab-on-a-chip-devices. Normally-closed design of the microvalve insulates the working fluid from the electric field, while providing low leakage up to 40 kPa inlet pressure. Prototypes are fabricated and tested for pull-in and flow characterization. Pull-in voltage is measured to be 150 V independent of the working fluid. No leakage is detected up to 20 kPa inlet pressure. © 2011 IEEE.
Citation - WoS: 5
Citation - Scopus: 5
Analysis and testing of a contraction-and-expansion micromixer for micromilled microfluidics
(Springer Heidelberg, 2017) Yildirim, Ender; Yıldırım, Ender; 31835; Makine Mühendisliği
In this paper, numerical analysis and experimental investigation of a micromixer, which was specifically designed for microfluidic devices fabricated by micromilling, is presented. The mixer is composed of series of contractions and expansions in zigzag arrangement along a mixing channel. Mixers, fabricated by micromilling on polymethylmethacrylate (PMMA), were tested with %0.1 Ponceau 4R red food dye solution and distilled water. According to experiment results, over 70% mixing efficiency could be obtained for the flows with Reynolds number (Re) greater than 40. It was also numerically shown that by increasing the number of successive contractions and expansions, it could be possible to achieve over 80% mixing efficiency when Re = 55 for the species with diffusion coefficient of 5 x 10(-9) m(2)/s. Although the micromixer was specifically designed for micromilling, it is expected that the mixer can be useful in any microfluidic device fabricated by any other technique.
Citation - WoS: 12
Citation - Scopus: 14
Bioglass-polymer composite scaffolds for bone tissue regeneration: a review of current trends
(Taylor & Francis Ltd, 2024) Motameni, Ali; Cardakli, Ismail Seckin; Gurbuz, Riza; Alshemary, Ammar Z. Z.; Razavi, Mehdi; Farukoglu, Omer Can
Biocompatible and bioactive composite scaffolds are essential in bone tissue regeneration because of their bioactivity and multilevel porous assemblies. There is a high demand for three-dimensional (3D) scaffolds to treat bone regeneration defects, trauma, and congenital skeletal abnormalities in the current scenario. The main objective of this review is to collect all the possible information concerning synthetic and natural polymer-Bioglass (BG)-based scaffold materials and systematically present them to summarize the importance and need for these materials. The importance of the bone tissue engineering field has been highlighted. Given the current challenges, a comprehensive description of materials fabrication and patterns in scaffold structures is required. This review also includes the most crucial aspect of this study: why are polymeric materials mixed with BG materials? Individually, both BG and polymeric materials lack specific essential characteristics to enhance the scope of these materials. However, preparing the composites of both ensures the researchers that composites of polymers and BG have improved properties that make them versatile materials for bone tissue engineering applications. This study deals with the individual drawbacks of the inorganic BGs, synthetic polymers, and the deficiencies of natural polymers. This study has also included a brief description of various scaffold fabricating techniques. Finally, this study revealed that by manufacturing and developing novel composite materials-scaffolds bearing the capability to repair, heal, and regenerate accidentally damaged or badly injured bones, many occasional problems can be solved in vivo and in vitro. Moreover, this review demonstrated that natural polymeric materials present many advantages over synthetic bone grafts. Yet, synthetic biomaterials have one additional attractive feature, as they have the flexibility to be designed according to the desired demands. These features make them the best choice for a wide range of bone tissue engineering projects for orthopedic surgeons.
Citation - WoS: 1
Citation - Scopus: 2
C-3 : configurable CAN FD controller: architecture, design and hardware implementation
(Ieee, 2017) Afsin, Mehmet Ertug; Schmidt, Klaus Werner; Schmidt, Ece Guran
CAN FD (Controller Area Network with Flexible Data Rate) is a new standard which provides a fast data rate while preserving the compatibility with CAN. In this paper, we propose the C-3 (Configurable CAN FD Controller) IP core architecture, which is compatible with the non-ISO CAN FD standard. C-3 supports up to 96 transmit and receive buffers. The transmit buffers are organized as mailboxes with CAN ID prioritization in frame transmission. A separate filter mask that can be configured by the user exists for each receive buffer. Different from existing CAN/CAN FD controllers, the numbers and sizes of transmit and receive buffers of C-3 can be configured at run time. To this end, C-3 enables the best use of a single controller hardware for different applications and enables improving the real-time communication performance. C-3 communicates with the host device over SPI without any specific interface requirements using the protocol that is developed in the scope of this paper. C-3 is implemented on an FPGA Evaluation Board and its functionality is verified at a data rate of 2 Mbps.
Citation - WoS: 14
Citation - Scopus: 20
Cavitation in Hydraulic Turbines
(Edizioni Ets, 2019) Ayli, Ece; 265836
Hydroenergy is one of the richest and most useful renewable energy sources in the world. Hydropower is a vital source as it is the clean energy source, sustainable and last but not least it is also cost-effective. One of the most important parameters that affect the performance of the hydraulic machines is the cavitation phenomenon, which is defined as the formation of the vapor bubbles in the liquid through any hydraulic turbine. In this paper, hydraulic machines, cavitation, types of cavitation are briefly described. After theoretical studies, analytical and numerical researches about cavitation in hydraulic machinery are discussed extensively. With those studies which are summarized in this paper covers a lot of ground about cavitation on the other hand further studies are needed about cavitation in hydro turbines. Numerical methods provide sufficient predictions for cavitation. However, numerical results should be verified by experimental measurements and detection methods to decide what intensity and which shape of cavitation is hazardous and vital, where the local pressure is lower than the vapor pressure and at which static pressure cavities start to grow and collapse.
Citation - WoS: 0
Citation - Scopus: 0
Clean Energy Generation in Residential Green Buildings- CH2
(inst Engineering Tech-iet, 2019) Yapici, Ekin Ozgirgin; Ayli, Ece
Due to the recent investigations, buildings consume a considerable amount of the electricity, drinking water, global final energy use and as a result are responsible for one third of the global carbon emissions. Therefore, building sector has a key role to reach global energy targets. In this sight, this study draws attention to the sustainable energy performances of green buildings (GBs) and aims towards the GBs concept which includes renewable sources in the construction and lifetime utilization. The remainder of the chapter is subjected as follows: Section 2.1 gives a brief information about residential GBs, and in Section 2.2, certification systems for sustainability ratings of residential GBs are given. This is followed by case studies related to the certification systems in Section 2.3 part. In Section 2.4, GBs incentives are summarized. Section 2.5 provides information about energy demand modelling for residential GBs, and in Section 2.6, clean energy generation systems in residential GBs are described in detail. Finally, outlook for the works that is performed up to now and the outlook for the future is given.
Citation - Scopus: 0
Comparison of Different Turbulent Models in Turbulent-Forced Convective Flow and Heat Transfer Inside Rectangular Cross-Sectioned Duct Heating At the Bottom Wall
(Springer International Publishing, 2014) Arslan, K.; Onur, Nevzat; Onur, N.; 53858; Makine Mühendisliği
In this study, steady-state turbulent-forced flow and heat transfer in a horizontal smooth rectangular cross-sectioned duct was numerically investigated. The study was carried out in the turbulent flow region where Reynolds number ranges from 1 × 104 to 5 × 104. The flow was developing both hydrodynamically and thermally. The bottom surface of the duct was assumed to be under constant surface temperature. A commercial CFD program Ansys Fluent 12.1 with different turbulent models was used to carry out the numerical study. Different turbulence models (k–ε Standard, k–ε Realizable, k–ε RNG, k–ω Standard and k–ω SST) were used. Based on the present numerical solutions, new engineering correlations were presented for the heat transfer and friction coefficients. The numerical results for different turbulence models were compared with each other and the experimental data available in the literature. It was observed that k–ε turbulence models represented the turbulent flow condition very well for the present study. © Springer International Publishing Switzerland 2014.
Citation - Scopus: 4
Design and Dimensional Optimization of A Novel Walking Mechanism With Firefly Algorithm
(Springer Netherlands, 2018) Selvi, Özgün; Selvi, Ö.; Yavuz, S.; Yavuz, Samet; 237938; Makine Mühendisliği
In this paper, a walking mechanism named Atlas is proposed which is a Watt-I type 6 link mechanism. First, the geometry is proposed and then kinematic analysis is done that will be used for the synthesis problem. Furthermore, constraints and an objective function are obtained from kinematic analysis. Then, these constraints are implemented to the Firefly Algorithm and dimensional parameters are obtained for a desired step profile. Finally, these dimensional parameters are tested. © Springer International Publishing AG 2018.
Citation - Scopus: 5
Design and Optimization of A Walking Over-Constrained Mechanism
(Springer Science and Business Media B.V., 2019) Selvi, Ö.; Yavuz, Samet; Ceccarelli, M.; 46949; Makine Mühendisliği
In this paper, a walking overconstrained mechanism with one DoF is presented. Firstly, its dimensional parameters and geometry are shown and a step profile which is wanted to be followed by end point of the walking mechanism is proposed. Kinematic equations of the walking mechanism are extracted to use them later as constraints for Firefly Algorithm. Algorithm is run in get the optimized dimensional parameters to provide the desired step profile. Results are presented. © 2019, Springer Nature Switzerland AG.
Citation - Scopus: 0
Droplet based cell screening system integrated with CMOS image sensor and android-based application
(Chemical and Biological Microsystems Society, 2020) Özkan, M.D.; Aslan, M.K.; Atik, A.C.; Özgür, E.; Yıldırım, E.; Külah, H.
This paper presents a droplet based single cell screening concept, where the cells encapsulated in microdroplets are monitored by integrating a commercial CMOS image sensor to the microfluidic chip. The images acquired through the image sensor are streamed and processed via an Android-based application on smartphone. This integrated system offers microscope-free screening of cells within the droplets based on their shapes. © 17CBMS-0001.
Citation - Scopus: 1
Effects of earthquake motion on mechanism operation: An experimental approach
(Levrotto and Bella, 2015) Selvi, Ö.; Selvi, Özgün; Ceccarelli, M.; Aytar, E.B.; 46949; Makine Mühendisliği
This paper presents an experimental characterization of the effects of earthquakes on the operation of mechanical systems with the help of CaPaMan (Cassino Parallel Manipulator), which is a 3 DOF robot that can fairly well simulate 3D earthquake motion. The sensitivity of operation characteristics of machinery to earthquake disturbance is identified and characterized through experimental tests. Experimental tests have been carried out by using a slider-crank linkage, a small car model, and LARM Hand as test-bed mechanisms that have been sensored with proper acceleration or force sensors. Results are reported and discussed to describe the effects of earthquake motion on the characteristics of mechanism operation as a service application of the robotic CaPaMan system.
Citation - Scopus: 3
Electrochemical discharge machining: trends and development
(Elsevier, 2021) Perveen, A.; Akar, Samet; Akar, S.; 315516; Makine Mühendisliği
The fabrication of microscale products revolutionizes the way manufacturing industries work today and has become the demand of current era due to their applications in various fields like microfluidics, biomedical testing systems, and microelectromechanical systems. Current research interest of manufacturing industries has shifted toward micromanufacturing process development. Electrochemical discharge machining (ECDM) is one of such recently developed process well known for its capability to machine both conductive as well as nonconductive materials. This process evolved from combination of electrodischarge machining and electrochemical machining. This hybrid machining process becomes an attractive technology due to its process simplicity and application in fabrication of microscale features and three-dimensional structures. This chapter will be focusing on the state-of-the-art review of the ECDM processes and its recent development. Various form of this process such as ECDM turning, ECMD-milling, and ECDM grinding will be presented in this chapter. Based on the research found in the literature, limitation associated with ECDM process will be demonstrated, and future research trend for overcoming these drawbacks will be narrated. © 2021 Elsevier Inc. All rights reserved.
Citation - WoS: 0
Finite Element Method Application For Nonlinear Mechanical Response Of Three-Dimensonal Beams Using Mathematica
(Gazi Univ, 2019) Tanriover, Hakan; 153029
Mechanical behavior of beams under large rotations and displacements was investigated. Using co-rotational approach given by Crisfield, three dimensional beam finite elements was modeled in Mathematica environment. The symbolic process of Mathematica provides keeping the parameters in the model as variables and beams having different geometries can be modelled easily. The yielding non-linear equation system was solved by utilizing Newton-Raphson technique. Dynamic balance equations and numerical time integration method were introduced, the solution process was left as a future work, however. Comparisons with the results of ANSYS and those of the works from the literature are accomplished.
Citation - Scopus: 1
Finite element modeling of mechanical micromachining
(CRC Press, 2017) Oliaei, S.N.B.; Demiral, Murat; Demiral, M.; Makine Mühendisliği
The knowledge about all these phenomena is necessary to fabricate microparts, satisfying required dimensional and geometrical tolerances and surface quality requirements. Therefore, developing predictive techniques to improve the quality of microparts has emerged as an important research area. Several approaches have been used to predict outputs of microcutting operations including analytical modeling, numerical techniques, molecular dynamics simulation, and experimental studies. As experimental studies are costly and time consuming and as they are only valid for the conditions and range of machining parameters used in the experiments, numerical methods are used as an alternative method to predict machining process outputs. © 2018 by Taylor & Francis Group, LLC.
Citation - WoS: 0
Citation - Scopus: 0
Fluorescent on-chip imager by using a tunable absorption filter
(Ieee, 2017) Arpali, Caglar; Yıldırım, Ender; Yildirim, Ender; Arpali, Serap Altay; 20809; 31835; 51304; Makine Mühendisliği
Citation - WoS: 0
Citation - Scopus: 2
Fused filament fabrication in CAD education: A closed-loop approach
(Sage Publications inc, 2025) Totuk, Onat Halis; Totuk, Onat Halis; Selvi, Özgün; Selvi, Ozguen; Akar, Samet; Akar, Samet; 315516; Mekatronik Mühendisliği; Makine Mühendisliği
Integrating low-cost fused filament fabrication 3D printing as a foundation for learning 3D modelling is explored. This method blends traditional computer aided design (CAD) instruction with additive manufacturing possibilities. Experimental results demonstrate increased comprehension speed and reduced learning time. This hands-on approach empowers students by enabling direct engagement with the modelling process. Analogous to reverse engineering, the strategy instructs engineering students from final product to model creation, closing the gap between theory and practice. Incorporating 3D printing bridges this divide, enhancing understanding, creativity and problem-solving. The study underscores technology's influence on learning strategies, aligning with the surge of 3D printing in education. Results link advanced design technology usage to improved student performance, with 3D-printed materials yielding 45% higher grades and 30% faster task completion. This study advocates curricular advancement for design-focused careers through enhanced technology integration and favourable 3D printing model reception.

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