Analysis of a multi-quasi-TEM-mode oversized waveguide with one hard wall using the aperture integral equation

2009 ◽  
Author(s):  
E. Alfonso ◽  
A. Valero-Nogueira ◽  
J.I. Herranz ◽  
F. Vico
Keyword(s):  
Integral Equation ◽  
Hard Wall ◽  
Oversized Waveguide ◽  
Tem Mode

DENSITY PROFILES OF A HARD GAUSSIAN OVERLAP FLUID BETWEEN HARD WALLS

2005 ◽  
Vol 19 (10) ◽  
pp. 1717-1729 ◽  
Author(s):  
M. MORADI ◽  
A. AVAZPOUR
Keyword(s):  
Density Functional Theory ◽  
Integral Equation ◽  
Correlation Function ◽  
Density Functional ◽  
Direct Correlation Function ◽  
Hard Wall ◽  
Density Profiles ◽  
Functional Theory ◽  
Orientation Model ◽  
The Density Functional Theory

The density profiles of a hard Gaussian overlap (HGO) fluid confined in between hard walls and in contact with a hard wall are studied using the density functional theory. The hyper-netted chain (HNC) approximation is used to find the coupled integral equations for the density profiles. The restricted orientation model (ROM) is used. The required homogeneous direct correlation function (DCF) is obtained by solving Ornstein–Zernike (OZ) integral equation numerically, using the Precus–Yevick (PY) approximation and the procedure mentioned by Letz and Latz [Phys. Rev.E60, 5865 (1999)]. We also obtained the DCF of hard ellipsoidal (HE) fluid by using the modified closest approach introduced by Rickayzen [Mol. Phys.68, 903 (1989)]. For both HGO and HE, we calculate the density profiles of molecules parallel and perpendicular to the walls and we compare the results. The calculations are performed for various values of packing fractions of the fluid and various molecular elongations. For moderate elongations, k≤3, the results for HGO and HE are almost the same, especially for the density profile of the molecules parallel to the walls but for k=5 there are some discrepancies between the results, in particular for the density profiles of the molecules perpendicular to the walls.

The Morphology and Crystallography of Diesel Particulate Emissions

1981 ◽  
Vol 39 ◽  
pp. 148-149
Author(s):  
R. Stevenson
Keyword(s):  
Diffraction Pattern ◽  
Carbon Films ◽  
Particulate Emissions ◽  
Diesel Particulate ◽  
Amorphous Carbon Films ◽  
Turbostratic Carbon ◽  
Diesel Particles ◽  
Tem Mode ◽  
Exhaust Stream ◽  
Diffraction Patterns

A study has been made of the morphology and crystallography of particulate emissions from indirect injection diesel engines. This particulate matter consists substantially of carbon (although hydrocarbons can be extracted with solvents). Samples were collected in a diluted exhaust stream on amorphous carbon films and examined in a JEM-200C electron microscope operated in the TEM mode with an accelerating voltage of 200 KV.The morphology of the diesel particles, as shown in Fig. 1, markedly resembles carbon blacks and consists of an agglomeration of quasispherical subunits arranged in chains or clusters. Only limited changes in morphology were observed as the number of subunits in the particle increased (although larger particles tended to be more cluster-like than the extended chain shown in Fig. 1). However, a dramatic effect of the number of subunits was observed on the character of the diffraction pattern. Smaller particles yielded a diffraction pattern consisting of very diffuse rings typical of turbostratic carbon; the diffraction patterns from the larger particles, however, although qualitatively similar, exhibited much sharper and less diffuse ring patterns.

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