Özkan, Necati
A non-contacting laser scanning profilometer, with associated hardware and software, is used for the determination of the overall shape and surface topography of cylindrical alumina compacts. The change in the shape distortion of the cylinder, defined as (R(max)-R(min))/R(min) (R is the radius of the compact), was monitored, as a function of the ambient temperature, during sintering. During sintering, an increase in the diameteral distortion values were observed. Certain surface topographic characteristics, also obtained by the laser scanning of the surfaces of the green compacts, were used to characterise the agglomerate deformation and breakdown. The deformation of agglomerates starts at very low compaction pressures. However, the inter-agglomerate pores are not eliminated until a compaction pressure of 37 MPa.


Selection of light source and implementation of data acquisition system of an optical experimental setup
Reyhanioğlu, Erinç; Öke, Gülay; Department of Physics (2004)
The construction of an optical experimental setup is the objective, to measure transmission coefficient of optical components used in plasma investigations. Thus, proper light source either with continuous or line radiation spectrum should be used. In addition, the detectors̕ output signal is recorded on a PC based data recorder after being digitized by an analog to digital converter card.
Three-dimensional numerical modelling of temporal and spatial pattern formation in a dc-driven gas discharge-semiconductor system
Rafatov, İsmail (IOP Publishing, 2016-12-01)
A three-dimensional numerical model is developed and applied to study the temporal and spatial pattern formation in the planar layered system, consisting of a glow discharge layer, coupled to a high ohmic semiconductor layer. The whole system is sandwiched between two planar electrodes, to which a dc voltage is applied.
Characterization of GZO thin films fabricated by RF magnetron sputtering method and electrical properties of In/GZO/Si/Al diode
Surucu, O. Bayrakli (Springer Science and Business Media LLC, 2019-11-01)
The main focus of this work is the structural and optical characterization of Ga-doped ZnO (GZO) thin film and determination of the device behavior of In/GZO/Si/Al diode. GZO thin films were deposited by RF magnetron sputtering technique from single target. The structural and morphological properties of GZO film were investigated by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) measurements. Optical properties of the fil...
Semi-empirical modeling and optimization of metal sputtering processes
Çimen, Özge; Kıncal, Serkan; Department of Chemical Engineering (2015)
Continuous miniaturization of thin film based electronic devices is the major motivator for research in physical vapor deposition (PVD) applications especially in military and aerospace applications. The challenges in the good quality thin film is the requirement for good mechanical, optical and electrical properties and high thickness uniformity across wafer. In this study, the magnetron sputtering system was investigated which is a commonly used technique to deposit thin films. Deposition and heat transfe...
Design Studies of Axial Vircator for High Power Microwave Generation
KÜÇÜK, İBRAHİM SEMİH; TİMUR, BÜŞRA; Tanc, Zafer; Demir, Şimşek (2017-09-27)
This paper presents design and simulation results of the cylindrical axial virtual cathode oscillator which is frequently used to damage electronic equipment by generating High Power Microwaves (HPM). Simulations are performed in MAGIC Tool Suite which uses FDTD-PIC algorithm to solve particle beam and field interactions. During the design procedure, AK Gap is changed from 5 mm to 12 mm and the scaling law is verified by simulation results. 9 mm AK gap values are selected as the most suitable one when outpu...
Citation Formats
I. AYDIN, B. BRISCOE, and N. Özkan, “3-D PROFILES AND SURFACE-TOPOGRAPHY OF ALUMINA COMPACTS,” INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE, pp. 345–352, 1995, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30736.