4,619 research outputs found
Sintering and properties of Si3N4 with and without additives by HIP treatment
Hot Isostatic Pressing (HIP) of Si3N4 powders with and without additives was performed using a glass container, and various kinds of pressureless-sintered Si3N4 were HIP'ed without a container. The effects of HIP treatment on density, microstructure, flexural strength, microhardness, and fracture toughness on Si3N4 ceramics were studied. Using a glass container it was difficult to reach theoretical density. The microhardness of HIP'ed Si3N4 without additives was low, and the fracture toughness of HIP'ed Si3N4 with and without additives was 22 to 25 W/m-K, and it decreased with increasing the amount of additives. The density and flexural strength, and hardness of pressureless-sintered Si3N4 which contained Al2O and Y2O3 as oxide additives were remarkably improved by HIP treatment using nitrogen as a pressure transmitting gas. It is very important to select the sintering conditions for fabricating the presintered body of Si3N4 in order to improve the mechanical properties of Si3N4 by HIP treatment
CoFeB Thickness Dependence of Thermal Stability Factor in CoFeB/MgO Perpendicular Magnetic Tunnel Junctions
Thermal stability factor (delta) of recording layer was studied in
perpendicular anisotropy CoFeB/MgO magnetic tunnel junctions (p-MTJs) with
various CoFeB recording layer thicknesses and junction sizes. In all series of
p-MTJs with different thicknesses, delta is virtually independent of the
junction sizes of 48-81 nm in diameter. The values of delta increase linearly
with increasing the recording layer thickness. The slope of the linear fit is
explained well by a model based on nucleation type magnetization reversal.Comment: 12 pages, 5 figure
Large thermal Hall coefficient in bismuth
We present a systematical study of thermal Hall effect on a bismuth single
crystal by measuring resistivity, Hall coefficient, and thermal conductivity
under magnetic field, which shows a large thermal Hall coefficient comparable
to the largest one in a semiconductor HgSe. We discuss that this is mainly due
to a large mobility and a low thermal conductivity comparing theoretical
calculations, which will give a route for controlling heat current in
electronic devices.Comment: 4pages, 3 figure
Limbic Regression with Derepression of Oedipal Feelings
Most knowledge of the normal preschool oedipal feelings for a parent of the opposite sex
come from reconstructive analysis of neurologically normal adults or from observation of phallic
stage children. We have discovered in the symptoms of a severely brain-damaged adolescent
evidence of a slightly different and interesting type. It seems to result from a biological unmasking
of repressed material by post-encephalitic age regression
3,5-Dinitrobenzyl methanesulfonate
The title compound, C8H8N2O7S, an intermediate in the synthesis of N,N-bis(2-hydroxyethyl)-3,5-dinitroaniline, exists as a discrete molecule; the nitro groups are twisted with respect to the aromatic system [dihedral angles = 17.0 (1) and 26.3 (1)°]
Effect of Electron Temperature on Negative Hydrogen Ion Production in a Low-Pressure Ar Discharge Plasma with Methane
Electron-Temperature Control by Movable Pins Installed in a Hollow Cathode for Discharge Plasmas
Bending and vibration of functionally graded material sandwich plates using an accurate theory
In this paper, the bending and the free flexural vibration behaviour of
sandwich functionally graded material (FGM) plates are investigated using
QUAD-8 shear flexible element developed based on higher order structural
theory. This theory accounts for the realistic variation of the displacements
through the thickness. The governing equations obtained here are solved for
static analysis considering two types of sandwich FGM plates, viz., homogeneous
face sheets with FGM core and FGM face sheets with homogeneous hard core. The
in-plane and rotary inertia terms are considered for vibration studies. The
accuracy of the present formulation is tested considering the problems for
which three-dimensional elasticity solutions are available. A detailed
numerical study is carried out based on various higher-order models to examine
the influence of the gradient index and the plate aspect ratio on the
global/local response of different sandwich FGM plates.Comment: 28 pages, 6 figures, 9 table
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