Person: UĞUZ, AGAH
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
UĞUZ
First Name
AGAH
Name
5 results
Search Results
Now showing 1 - 5 of 5
Publication Innovative low-cost, cold-walled CVD process development and CNT production by ethanol decomposition on iron-nanoparticles(Taylor & Francis Ltd, 2022-08-31) Cilsal, O. Ozan; Çakır, M. Cemal; Uğuz, Agah; Cilsal, O. Ozan; ÇAKIR, MUSTAFA CEMAL; UĞUZ, AGAH; Mühendislik Fakültesi; Makine Mühendisliği Bölümü; 0000-0002-5736-8557; CKX-4912-2022; HOR-0562-2023; EBY-1783-2022A novel cold-walled CVD reactor has been designed for low-cost CNT synthesis. Aim was to eliminate the need for electric furnace, carbon-containing gas tanks and flowmeters, reducing energy consumption and gas emissions. Iron nanoparticles emulsion dip coating was preferred to simplify the catalyst preparation process. As carbon precursor, ethanol is used. Cost analysis was made to determine the initial investment needed. Design is also patented against unauthorized commercial usage. Samples obtained were characterized using SEM and Raman spectroscopy. Multi-walled CNTs and CNFs with diameters from 50nm to700 nm in straight and helical form have been synthesized. It has been observed that increase of the process duration and remaining soot on the reactor components has a diameter reducing and yield increasing effect on CNTs. Raman spectroscopy results show D, G and 2D Bands on the samples.Publication Determination of the crystallographic parameters of a fcc metal by means of electron channelling patterns(Wiley, 2003-01-01) Uğuz, Agah; UĞUZ, AGAH; Mühendislik Mimarlık Fakültesi; GFU-0210-2022Indexing and mapping of selected area electron channelling patterns (SAECPs) of an Al-Zn-Mg alloy have been performed. Although, channelling patterns are similar for crystals having the same system, since the interplanar spacing and the angular band width depend on lattice parameter, the details of the map will differ for every material. Angles between the poles and the angular separations of channelling bands were measured on the micrographs and calculated with the well known equations and found to be well in agreement within the error limits. Also the channelling line widths were calculated with the help of extinction distances of the reflecting planes. Structure factors and atomic scattering factors for selected reflections were also calculated for the present alloy whose a = 4.054 Angstrom.Publication A comparative study of electrospinning process for two different collectors: The effect of the collecting method on the nanofiber diameters(Japan Soc Mechanical Engineers, 2019-01-01) Çavdar, Fatma Yıdız; Uğuz, Agah; UĞUZ, AGAH; Mühendislik Fakültesi; Makine Mühendisliği BölümüIn this study, an experimental investigation of the electrospinning process has been conducted using two successive Taguchi experimental designs, namely L-18 (3(5)) and L-9 (3(4)) for the electrospinning setups with a rotating drum and a stationary plate, respectively. The processing parameters are; concentration of poly(vinyl alcohol) in aqueous solution, applied voltage, distance between the needle and the collector, flow rate of the polymer solution and the rotational speed of the collecting drum. The primary process setup is used to analyse the effects of the parameters to the diameter of nanofibers and its standard deviation (SD), through examinations of the range analysis and graphical interpretations. The secondary process set up is used to gather the data to verify the results and to compare the effects of the collecting methods on the process outputs. A short literature review of the publications on which parameter effects were analysed by statistical methods is also presented.Publication Modeling the effects of mechanical loads - finite element modeling of ball joints under dynamic loading(Carl Hanser Verlag, 2004-01-01) Uğuz, A; Oka, S. H; UĞUZ, AGAH; Oka, S. H.; Mühendislik Fakültesi; GFU-0210-2022; HVN-4904-2023In this investigation, a ball joint, which is the major functional part in a car, has been modeled to predict its fatigue life. In order to confirm the accuracy of the research, initially a modal analysis was performed, so the natural frequency of the structure was verified. It has been found that, the calculated natural frequency of the structure is much lower than its own natural frequency. The results, which were confirmed by experimental studies, have been interpreted by using analysis techniques and compared with theoretical outcomes.Publication Determination of mechanical behavior of metal-rubber compound pulley part, finite element analysis and verification with tests(Gazi Üniversitesi, 2020-01-01) Uğuz, Agah; Penekli, Ufuk; UĞUZ, AGAH; Fen Bilimleri Enstitüsü; Makine Mühendisliği Bölümü; 0000-0002-9244-3671; EBY-1783-2022Rubber is one of the most important materials of modern industry and have a wide range of usage owing to a number of superior properties. In this study, the mechanical behaviour of the metal-rubber combination pulley part transferring motion in the engine through the timing belt was examined by the finite element method, confirmed experimentally, and optimized. Uniaxial tension and pure shear tests were carried out physically to develop a hyperelastic material model. 3 parameter Mooney-Rivlin hyperelastic material constants were calculated by using force-elongation values obtained from uniaxial tension and, pure shear tests. Afterwards, pulley geometry was modelled, and displacements, stresses, reaction moments were examined under various torsional loadings. To confirm the accuracy of the pulley analysis, a servomotor driven pulley torsion testing machine was designed and manufactured. Then, torque and angle values were measured by testing the pulley parts at the same torsional angles. By this study, it was proven that mechanical behaviour of pulley can be expressed numerically. After validation of the material model and the results obtained using analysis method, the pulley geometry was further improved the stress levels on the rubber material were reduced 28% under the same loading conditions by using optimization tools.