Functional design and analysis of intelligent illuminating system

2019 ◽  
Author(s):  
Rui Mu
Author(s):  
J. M. Pankratz

It is often desirable in transmission electron microscopy to know the vertical spacing of points of interest within a specimen. However, in order to measure a stereo effect, one must have two pictures of the same area taken from different angles, and one must have also a formula for converting measured differences between corresponding points (parallax) into a height differential.Assume (a) that the impinging beam of electrons can be considered as a plane wave and (b) that the magnification is the same at the top and bottom of the specimen. The first assumption is good when the illuminating system is overfocused. The second assumption (the so-called “perspective error”) is good when the focal length is large (3 x 107Å) in relation to foil thickness (∼103 Å).


Author(s):  
N. Tamura ◽  
T. Goto ◽  
Y. Harada

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.


Author(s):  
K. Shiraishi ◽  
T. Katsuta ◽  
S. Ozasa ◽  
H. Todokoro

We have recently completed a newly designed 650KV electron microscope. An external view of this advanced instrument is shown in Figure 1. A symmetrical Cockcroft-Walton circuit has been adopted as the high voltage generator. The cathode is heated by high frequency power; a battery is not employed. The high voltage stability is better than 1 x 10-5/min.The sectional diagram of the column shown in Figure 2 is 420mm in diameter and 2750mm in height. The illuminating system consists of a double condenser lens and a magnetic alignment device. Dual deflector assemblies for dark and bright field images, selectable by push button, are built beneath the condenser lens. Two selectable stigmator power supplies are also provided for dark and bright field image operation.


Author(s):  
L. F. Allard ◽  
E. Völkl ◽  
T. A. Nolan

The illumination system of the cold field emission (CFE) Hitachi HF-2000 TEM operates with a single condenser lens in normal imaging mode, and with a second condenser lens excited to give the ultra-fine 1 nm probe for microanalysis. The electron gun provides a guaranteed high brightness of better than 7×l08 A/cm2/sr, more than twice the guaranteed brightness of Schottky emission guns. There have been several articles in the recent literature (e.g. refs.) which claim that the geometry of this illumination system yields a total current which is so low that when the beam is spread at low magnifications (say 10 kX), the operator must “keep his eyes glued to the binoculars” in order to see the image. It is also claimed that this illuminating system produces an isoplanatic patch (the area over which image character does not vary significantly) at high magnification which is so small that the instrument is ineffective for recording high resolution images.


2003 ◽  
Vol 31 (3) ◽  
pp. 132-158 ◽  
Author(s):  
R. E. Okonieski ◽  
D. J. Moseley ◽  
K. Y. Cai

Abstract The influence of tread designs on tire performance is well known. The tire industry spends significant effort in the development process to create and refine tread patterns. Creating an aesthetic yet functional design requires characterization of the tread design using many engineering parameters such as stiffness, moments of inertia, principal angles, etc. The tread element stiffness is of particular interest because of its use to objectively determine differences between tread patterns as the designer refines the design to provide optimum levels of performance. The tread designer monitors the change in stiffness as the design evolves. Changes to the geometry involve many attributes including the number of sipes, sipe depth, sipe location, block element edge taper, nonskid depth, area net-to-gross, and so forth. In this paper, two different formulations for calculating tread element or block stiffness are reviewed and are compared to finite element results in a few cases. A few simple examples are shown demonstrating the basic functionality that is possible with a numerical method.


2016 ◽  
Vol 2016 (12) ◽  
pp. 3582-3601
Author(s):  
T. Kate Mignone ◽  
Andrew Perham ◽  
Gregory Heath ◽  
James Sullivan
Keyword(s):  

ACS Sensors ◽  
2021 ◽  
Author(s):  
Elizabeth Voke ◽  
Rebecca L. Pinals ◽  
Natalie S. Goh ◽  
Markita P. Landry
Keyword(s):  

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 10
Author(s):  
Luca Bruzzone ◽  
Mario Baggetta ◽  
Shahab E. Nodehi ◽  
Pietro Bilancia ◽  
Pietro Fanghella

This paper presents the conceptual and functional design of a novel hybrid leg-wheel-track ground mobile robot for surveillance and inspection, named WheTLHLoc (Wheel-Track-Leg Hybrid Locomotion). The aim of the work is the development of a general-purpose platform capable of combining tracked locomotion on irregular and yielding terrains, wheeled locomotion with high energy efficiency on flat and compact grounds, and stair climbing/descent ability. The architecture of the hybrid locomotion system is firstly outlined, then the validation of its stair climbing maneuver capabilities by means of multibody simulation is presented. The embodiment design and the internal mechanical layout are then discussed.


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