Acoustic Monitoring of Anomalous Stressed Zones, Determination of their Positions, Surfaces, Evaluation of Catastrophic Risk.

2020 ◽  
Author(s):  
Olga Hachay ◽  
Oleg Khachay
Keyword(s):  
Iterative Algorithms ◽  
Block Size ◽  
Structural Features ◽  
Monitoring Methods ◽  
Elastic Parameters ◽  
Mining System ◽  
Geophysical Monitoring ◽  
Lower Rank ◽  
Linearly Polarized ◽  
Sound Diffraction

<p>Self-organization is not a universal property of matter, it exists under certain internal and external conditions and this is not associated with a special class of substances. The study of the morphology and dynamics of migration of anomalous zones associated with increased stresses is of particular importance in the development of deep deposits, complicated by dynamic phenomena in the form of mountain impacts. An important tool for this study is geophysical exploration. To describe the geological environment in the form of an array of rocks with its natural and technogenic heterogeneity, one should use its more adequate description, which is a discrete model of the medium in the form of a piecewise inhomogeneous block medium with embedded heterogeneities of a lower rank than the block size. This nesting can be traced several times, i.e. changing the scale of the research, we see that heterogeneities of a lower rank now appear in the form of blocks for heterogeneities of the next rank. A simple averaging of the measured geophysical parameters can lead to distorted ideas about the structure of the medium and its evolution. We have analyzed the morphology of the structural features of disintegration zones before a strong dynamic phenomenon. The introduction of the proposed integrated passive and active geophysical monitoring into the mining system, aimed at studying the transient processes of the redistribution of stress-strain and phase states, can help prevent catastrophic dynamic manifestations during the development of deep-seated deposits. Active geophysical monitoring methods should be tuned to a model of a hierarchical heterogeneous environment. Iterative algorithms for 2-D modeling and interpretation for sound diffraction and a linearly polarized transversal elastic wave on the inclusion with a hierarchical elastic structure located in the J-th layer of the N-layer elastic medium are constructed. The case is considered when the inclusion density of each rank coincides with the density of the containing layer, and the elastic parameters of inclusion of each rank differ from the elastic parameters of the containing layer.<br><br></p>

scholarly journals Geophysical Monitoring Methods Evaluation for the FutureGen 2.0 Project

2014 ◽  
Vol 63 ◽  
pp. 4394-4403 ◽  
Author(s):  
Chris E. Strickland ◽  
Vince R. Vermeul ◽  
Alain Bonneville ◽  
E. Charlotte Sullivan ◽  
Tim C. Johnson ◽  
...  
Keyword(s):  
Monitoring Methods ◽  
Geophysical Monitoring

scholarly journals LONG-TERM STABILITY MONITORING OF THE MINING BLOCKS IN ESTONIAN OIL SHALE MINES

2006 ◽  
Vol 1 ◽  
pp. 206
Author(s):  
J.-R. Pastarus
Keyword(s):  
Influence Factors ◽  
Monitoring Methods ◽  
Mining System ◽  
Term Stability ◽  
Long Term Stability ◽  
Room And Pillar Mining ◽  
Convergence Method ◽  
Pillar Mining

This paper deals with long-term stability prediction and monitoring methods by room-and-pillar mining system. Roof-to-floor convergence and conditional thickness methods suit for calculations. They allow determination of the location, area and time of the collapse in a mining block. The uncertainty in time is less than 10 % at the 95 % confidence level. Roof-to-floor convergence method is preferred; it takes into consideration all the geological and mining feature in the critical area. Conditional thickness method demands supplementary investigations, determination of the influence factors on the process. The applicability of these methods is clearly demonstrated.

scholarly journals Fully Parallel Architecture of QC-LDPC Decoder for IEEE 802.11n Application

2020 ◽  
Vol 9 (1) ◽  
pp. 1726-1731
Keyword(s):  
Error Correction ◽  
Message Passing ◽  
Iterative Algorithms ◽  
Parallel Architecture ◽  
Block Size ◽  
Ldpc Code ◽  
Ieee 802.11N ◽  
Ldpc Decoder ◽  
Ldpc Decoding ◽  
Finite State

A Low density parity check (LDPC) code, have become most accepted error correction code for efficient and reliable communication due to a good performance. The VLSI implementation of LDPC decoder is a big challenge. Iterative message passing decoding algorithms propose excellent error correction performance but a large decoding complexity for different code lengths and code rates. The LDPC codes decoder also faced many difficulties such as small chip areas , reduced interconnect complexities, lower power dissipation. In this paper, the design of the of Quasi Cyclic(QC)LDPC decoder for the IEEE 802.11n standard with 1/2 code rate, 648coward length and sub-block size z =27 have been designed. Initially different iterative algorithms for LDPC decoding are discussed. The Fully parallel architecture of the LDPC decoder for IEEE 802.11n standard using Min Sum decoding algorithm (MSA)has been designed. Further, the design Quasi Cyclic(QC) LDPC decoder for IEEE 802.11n have been modified by using a Finite State Machine (FSM) to control the complete decoding process.

In-Process Monitoring of Selective Laser Melting: Spatial Detection of Defects Via Image Data Analysis

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Marco Grasso ◽  
Vittorio Laguzza ◽  
Quirico Semeraro ◽  
Bianca Maria Colosimo
Keyword(s):  
Selective Laser Melting ◽  
Process Monitoring ◽  
Vision System ◽  
Image Data ◽  
Structural Features ◽  
Visible Range ◽  
Monitoring Methods ◽  
Laser Melting ◽  
Industrial Sectors ◽  
Spatial Detection

Selective laser melting (SLM) has been attracting a growing interest in different industrial sectors as it is one of the key technologies for metal additive manufacturing (AM). Despite the relevant improvements made by the SLM technology in the recent years, process capability is still a major issue for its industrial breakthrough. As a matter of fact, different kinds of defect may originate during the layerwise process. In some cases, they propagate from one layer to the following ones leading to a job failure. In other cases, they are hardly visible and detectable by inspecting the final part, as they can affect the internal structure or structural features that are difficult to measure. This implies the need for in-process monitoring methods able to rapidly detect and locate defect onsets during the process itself. Different authors have been investigating machine sensorization architectures, but the development of statistical monitoring techniques is still in a very preliminary phase. This paper proposes a method for the detection and spatial identification of defects during the layerwise process by using a machine vision system in the visible range. A statistical descriptor based on principal component analysis (PCA) applied to image data is presented, which is suitable to identify defective areas of a layer. The use of image k-means clustering analysis is then proposed for automated defect detection. A real case study in SLM including both simple and complicated geometries is discussed to demonstrate the performances of the method.

scholarly journals Assessment of geophysical monitoring methods for detection of brine and CO2 leakage in drinking water aquifers

2019 ◽  
Vol 90 ◽  
pp. 102803 ◽  
Author(s):  
Xianjin Yang ◽  
Thomas A. Buscheck ◽  
Kayyum Mansoor ◽  
Zan Wang ◽  
Kai Gao ◽  
...  
Keyword(s):  
Drinking Water ◽  
Co2 Leakage ◽  
Monitoring Methods ◽  
Geophysical Monitoring

scholarly journals Effectiveness of Geophysical Monitoring Methods in Detecting Brine and CO2 Leakage in Underground Sources of Drinking Water

2018 ◽  
Author(s):  
Xianjin Yang ◽  
◽  
Thomas A. Buscheck ◽  
Kayyum Mansoor ◽  
Zan Wang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Monitoring Methods ◽  
Geophysical Monitoring

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

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