scholarly journals Application of Lanczos and Schur Vectors in Structural Dynamics

2008 ◽  
Vol 15 (3-4) ◽  
pp. 459-466
Author(s):  
M. Radeş
Keyword(s):  
Structural Dynamics ◽  
Sensor Location ◽  
Test Analysis ◽  
Large Size ◽  
Dynamic Analyses ◽  
Computer Storage ◽  
Analysis Models

The paper explains the advantages of using Lanczos/Schur vectors when performing dynamic analyses of very large models: faster computation of low spectrum eigenproperties, reduced computer storage requirements, increased robustness of test-analysis models, and sensor location by the effective independence method without solving large size eigenproblems.

Research on Fault Analysis and Fault Diagnostics Technology for Large-Size Equipments in Stopes

2013 ◽  
Vol 706-708 ◽  
pp. 957-962
Author(s):  
Bao Cai Zhang ◽  
Meng Shao ◽  
Guo Ming Du
Keyword(s):  
Economic Benefits ◽  
Fault Analysis ◽  
Test Analysis ◽  
Status Monitoring ◽  
Rotation System ◽  
Analytical Reasoning ◽  
Large Size ◽  
Operation Process ◽  
Current Voltage ◽  
Lifting System

At present,the main equipments is electric shovels of Dagushan Iron Ore Mine, Due to a variety of factors, inevitably, there are many faults, overcurrent, overvoltage and overload are the ones with highest incidence. at the same time, the lifting system, push-press system, rotation system on the electric shovel and the overcurrent protection system of the main transformer will make appropriate actions and instantaneously shut down the electric shovel. In this article, microcomputer as its control core, It can comprehensively take use of equipment status monitoring technology, test analysis technology, signal processing technology, embedded technology, etc., carry out analytical reasoning for the equipment status information during operation process of electric shovel such as current, voltage, etc., according to the simulation experiment and operation inspection and test, the large-size equipment diagnosis & analysis device is completed for stopes has the advantages such as full-featured functions, convenient and reliable operation, considerable economic benefits.

Coherency loss in γ' precipitates in nickel-base superalloy

1983 ◽  
Vol 41 ◽  
pp. 244-245
Author(s):  
R. A. Ricks ◽  
Angus J. Porter
Keyword(s):  
Lattice Mismatch ◽  
Lattice Parameter ◽  
Nickel Base Superalloy ◽  
Large Size ◽  
The Matrix ◽  
Nimonic 80A ◽  
Interfacial Dislocations ◽  
Nickel Base ◽  
Coherency Loss ◽  
Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

Microdensitometer—computer correlation analysis of ultrastructural periodicity

1978 ◽  
Vol 36 (2) ◽  
pp. 32-33
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker
Keyword(s):  
Correlation Analysis ◽  
Background Noise ◽  
Computer Control ◽  
Optical Diffraction ◽  
Screw Thread ◽  
Straight Line ◽  
Computer Storage ◽  
Correlation Process ◽  
Electron Microscope Image ◽  
Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

Automatic analysis of Kikuchi diffraction patterns

1994 ◽  
Vol 52 ◽  
pp. 900-901
Author(s):  
H. Weiland ◽  
D. P. Field
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
Relevant Information ◽  
Crystalline Materials ◽  
Large Size ◽  
Transmission Electron ◽  
New Type ◽  
Diffraction Patterns ◽  
Orientation Determination

Recent advances in the automatic indexing of backscatter Kikuchi diffraction patterns on the scanning electron microscope (SEM) has resulted in the development of a new type of microscopy. The ability to obtain statistically relevant information on the spatial distribution of crystallite orientations is giving rise to new insight into polycrystalline microstructures and their relation to materials properties. A limitation of the technique in the SEM is that the spatial resolution of the measurement is restricted by the relatively large size of the electron beam in relation to various microstructural features. Typically the spatial resolution in the SEM is limited to about half a micron or greater. Heavily worked structures exhibit microstructural features much finer than this and require resolution on the order of nanometers for accurate characterization. Transmission electron microscope (TEM) techniques offer sufficient resolution to investigate heavily worked crystalline materials.Crystal lattice orientation determination from Kikuchi diffraction patterns in the TEM (Figure 1) requires knowledge of the relative positions of at least three non-parallel Kikuchi line pairs in relation to the crystallite and the electron beam.

Immunoprobe localization in mammalian embryos

1990 ◽  
Vol 48 (3) ◽  
pp. 32-33
Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Thin Sections ◽  
Relative Lack ◽  
Large Size ◽  
Mammalian Embryos ◽  
Antigen Localization ◽  
Difficult Challenge ◽  
Lowicryl K4m ◽  
Fertilized Egg

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.

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