Pressures sintering of silicon nitride with yttrum oxide and aluminium oxide as sintering additives

Silan, Murat


Pressure-driven water flow through hydrophilic alumina nanomembranes
Koklu, Anil; Li, Jianing; Şengör, Sema Sevinç; Beskok, Ali (2017-07-01)
We present an experimental study that focuses on pressure-driven flow of distilled water through. alumina membranes with 5, 10 and 20 nm pore radii. The nanopore geometry, pore size and porosity are characterized using scanning electron microscopy images taken pre- and post-flow experiments. Comparisons of these images have shown reduction in the pore size, which is attributed to precipitation of hydroxyl groups on alumina surfaces. Measured flowrates compared with the Hagen-Poiseuille flow relations consis...
Pressure-dependent Raman modes near the cubic-tetragonal transition in strontium titanate
KİRACI, ALİ; Yurtseven, Hasan Hamit (Wiley, 2018-03-01)
The pressure dependence of the Raman frequency shifts of various Raman modes is calculated at room temperature using the volume data from the literature for the cubic-tetragonal transition in SrTiO3. The isothermal mode Gruneisen parameters of those Raman modes are obtained, which decrease with increasing pressure for this molecular crystal. Calculated Raman frequencies are then used to predict the damping constant and the inverse relaxation time of those Raman modes as a function of pressure by means of th...
Compression heating of selected pressure transmitting fluids and liquid foods during high hydrostatic pressure treatment
BUZRUL, Sencer; Alpas, Hami; LARGETEAU, Alain; BOZOGLU, Faruk; DEMAZEAU, Gerard (2008-04-01)
Three pressure transmitting fluids (water, ethylene glycol, and ethanol) and three liquid foods (orange juice, whole, and skim milk) were pressurized at 100-400 MPa and at 5, 20 and 35 degrees C, using different compression rates (100, 200, and 300 MPa/min) to evaluate the adiabatic heating phenomena during high hydrostatic pressure (HHP) processing. A pressure vessel (3 L volume) in which liquid foods could be introduced directly was used to demonstrate the compression heating phenomena in large-scale comm...
Pressure, gas ratio and operation voltage optimization of a helium-neon laser
Bilgili, Hulusi Birol; Esendemir, Akif; Department of Physics (2005)
Aim of this thesis is to investigate the optimum working parameters of a helium-neon laser. Partial pressure ratios, total pressures of the gases and voltage-current characteristics were studied. The analysis of the results includes the minor factors (impurity, volume, etc.) and their effects to main parameters (laser power, voltage, current). Tables, which were formed by measured optical parameters as wavelength and power, converted to graphs and from these graphs optimal working conditions for the laser a...
Temperature-dependent optical properties of GaSe layered single crystals
IŞIK, MEHMET; TUĞAY, EVRİN; Gasanly, N. M. (2016-01-01)
Optical properties of GaSe single crystals have been investigated using temperature-dependent transmission and room temperature reflection measurements in the wavelength range of 380-1100nm. The analysis of the absorption data at room temperature showed the existence of indirect transitions in the crystal with energy band gap of 1.98eV. Temperature dependence of the transmission measurements revealed the shift of the absorption edge toward lower energy as temperature is increased from 10 to 280K. The rate o...
Citation Formats
M. Silan, “Pressures sintering of silicon nitride with yttrum oxide and aluminium oxide as sintering additives,” Middle East Technical University, 1993.