Compressible Narrow Groove Analysis—Part 1: Derivation

1998 ◽  
Vol 120 (4) ◽  
pp. 758-764 ◽  
Author(s):  
Coda H. T. Pan
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Empirical Formula ◽  
Pressure Field ◽  
Data Bank ◽  
Companion Paper ◽  
Global Scale ◽  
The State ◽  
Fine Scale ◽  
Scale Analysis

The technique of High-Resolution Modeling of Thin Films is combined with a two-scale analysis to formulate the Compressible Narrow Groove Analysis. The data bank of Fukui and Kaneko (1990) is emulated in the form of an empirical formula to treat the state of arbitrary rarefaction of the gas film. Due to its transcendental character, the compressible fine-scale solution is treated on the fly as a part of the global-scale computation. Derivations for the Compressible Narrow Groove Analysis are presented here. In a companion paper (Pan, 1998), the Compressible Narrow Groove Analysis is used to compute the pressure field of a spherical device operating in both the pressurizing and evacuating modes.

Compressible Narrow Groove Analysis—Part 2: Computation of Pressure Field in a Spherical Device Rotating in Either Direction

1998 ◽  
Vol 120 (4) ◽  
pp. 765-771 ◽  
Author(s):  
Coda H. T. Pan
Keyword(s):  
Thin Film ◽  
High Resolution ◽  
High Performance ◽  
Pressure Field ◽  
High Vacuum ◽  
Numerical Procedure ◽  
Vacuum State ◽  
Companion Paper ◽  
Accommodation Coefficient ◽  
Reversed Rotation

Compressible Narrow Groove Analysis, as derived in a companion paper (Pan, 1998), is a model implementation of Thin Film High-Resolution Modeling for gas films. This paper describes the numerical procedure to compute the pressure field in a centered spherical device, which has general design features originally intended for a high performance gas bearing gyroscope (Keating and Pan, 1968). The number of groove patterns is varied to bring out the significance of the local compressibility number. Increased local compressibility, associated with reduced number of groove patterns, causes successive degradation of the pressurization capacity until it is entirely suppressed at 32 groove patterns. Further study is made with reversed rotation to create a high vacuum state in the gas film concurrent with a large compressibility number. The evacuation operation (with reversed rotation) is relatively insensitive to the number of groove patterns, but is highly dependent on the accommodation coefficient. Experience in preparing these examples lends evidence to the robustness of Thin Film High-Resolution Modeling. Trouble free iterative computations are routinely performed for the local Knudsen number in excess of 109 and the effective local compressibility number larger than 100.

High Resolution Stereography of Complementary Freeze-Fracture Replicas Reveals the Presence of Depressions Opposite Membrane Associated Particles of Split Membranes

1971 ◽  
Vol 29 ◽  
pp. 442-443
Author(s):  
Russell L. Steere
Keyword(s):  
High Resolution ◽  
Cardiac Muscle ◽  
Electron Micrographs ◽  
Chromic Acid ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Fine Scale ◽  
Acid Cleaning ◽  
Cleaning Solution

Complementary replicas have revealed the fact that the two common faces observed in electron micrographs of freeze-fracture and freeze-etch specimens are complementary to each other and are thus the new faces of a split membrane rather than the original inner and outer surfaces (1, 2 and personal observations). The big question raised by published electron micrographs is why do we not see depressions in the complementary face opposite membrane-associated particles? Reports have appeared indicating that some depressions do appear but complementarity on such a fine scale has yet to be shown.Dog cardiac muscle was perfused with glutaraldehyde, washed in distilled water, then transferred to 30% glycerol (material furnished by Dr. Joaquim Sommer, Duke Univ., and VA Hospital, Durham, N.C.). Small strips were freeze-fractured in a Denton Vacuum DFE-2 Freeze-Etch Unit with complementary replica tooling. Replicas were cleaned in chromic acid cleaning solution, then washed in 4 changes of distilled water and mounted on opposite sides of the center wire of a Formvar-coated grid.

Formation of Large, Orientation-Controlled, Nearly Single Crystalline Si Thin Films on SiO2 Using Contact Printing of Rolled and Annealed Nickel Tapes

2003 ◽  
Vol 762 ◽  
Author(s):  
Hwang Huh ◽  
Jung H. Shin
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Resolution ◽  
Amorphous Silicon ◽  
Tem Analysis ◽  
Contact Printing ◽  
Single Crystalline ◽  
High Resolution Tem ◽  
Lateral Crystallization ◽  
Si Films

AbstractAmorphous silicon (a-Si) films prepared on oxidized silicon wafer were crystallized to a highly textured form using contact printing of rolled and annealed nickel tapes. Crystallization was achieved by first annealing the a-Si film in contact with patterned Ni tape at 600°C for 20 min in a flowing forming gas (90 % N2, 10 % H2) environment, then removing the Ni tape and further annealing the a-Si film in vacuum for2hrsat600°C. An array of crystalline regions with diameters of up to 20 μm could be formed. Electron microscopy indicates that the regions are essentially single-crystalline except for the presence of twins and/or type A-B formations, and that all regions have the same orientation in all 3 directions even when separated by more than hundreds of microns. High resolution TEM analysis shows that formation of such orientation-controlled, nearly single crystalline regions is due to formation of nearly single crystalline NiSi2 under the point of contact, which then acts as the template for silicide-induced lateral crystallization. Furthermore, the orientation relationship between Si grains and Ni tape is observed to be Si (110) || Ni (001)

Atomic structure of [0001]-tilt grain boundaries in ZnO:  A high-resolution TEM study of fiber-textured thin films

2004 ◽  
Vol 70 (12) ◽  
Author(s):  
Fumiyasu Oba ◽  
Hiromichi Ohta ◽  
Yukio Sato ◽  
Hideo Hosono ◽  
Takahisa Yamamoto ◽  
...  
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
High Resolution Tem

High-resolution quantitative X-ray microanalysis of Nb/AI multilayer thin films using the ζ-factor approach

1999 ◽  
Vol 79 (6) ◽  
pp. 1423-1442 ◽  
Author(s):  
G. Lucadamo ◽  
M. Watanabe ◽  
K. Barmak ◽  
D. B. Williams ◽  
C. Michaelsen ◽  
...  
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Multilayer Thin Films ◽  
X Ray

Construction of the state diagram of polymer blend thin films using differential AC chip calorimetry

Polymer ◽  
2011 ◽  
Vol 52 (19) ◽  
pp. 4277-4283 ◽  
Author(s):  
Nicolaas-Alexander Gotzen ◽  
Guy Van Assche ◽  
Bruno Van Mele
Keyword(s):  
Thin Films ◽  
Polymer Blend ◽  
State Diagram ◽  
The State ◽  
Chip Calorimetry

Very high resolution environmental predictors in species distribution models

2013 ◽  
Vol 38 (1) ◽  
pp. 79-96 ◽  
Author(s):  
Jean-Nicolas Pradervand ◽  
Anne Dubuis ◽  
Loïc Pellissier ◽  
Antoine Guisan ◽  
Christophe Randin
Keyword(s):  
High Resolution ◽  
Species Distribution ◽  
Species Distribution Models ◽  
Environmental Data ◽  
Swiss Alps ◽  
Fine Scale ◽  
Distribution Models ◽  
Model Quality ◽  
Vegetation Height ◽  
Very High

Recent advances in remote sensing technologies have facilitated the generation of very high resolution (VHR) environmental data. Exploratory studies suggested that, if used in species distribution models (SDMs), these data should enable modelling species’ micro-habitats and allow improving predictions for fine-scale biodiversity management. In the present study, we tested the influence, in SDMs, of predictors derived from a VHR digital elevation model (DEM) by comparing the predictive power of models for 239 plant species and their assemblages fitted at six different resolutions in the Swiss Alps. We also tested whether changes of the model quality for a species is related to its functional and ecological characteristics. Refining the resolution only contributed to slight improvement of the models for more than half of the examined species, with the best results obtained at 5 m, but no significant improvement was observed, on average, across all species. Contrary to our expectations, we could not consistently correlate the changes in model performance with species characteristics such as vegetation height. Temperature, the most important variable in the SDMs across the different resolutions, did not contribute any substantial improvement. Our results suggest that improving resolution of topographic data only is not sufficient to improve SDM predictions – and therefore local management – compared to previously used resolutions (here 25 and 100 m). More effort should be dedicated now to conduct finer-scale in-situ environmental measurements (e.g. for temperature, moisture, snow) to obtain improved environmental measurements for fine-scale species mapping and management.

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