Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"gob"”.
-
GASMAK2 model for longwall gob gas emission
… methane control techniques that are needed for gob gas control. It is an excellent approximation, and the use of this model in conjunction with a careful data collection program should clearly indicate what future methane controls are needed.
-
Preventing spontaneous combustion in gob areas of retreating longwall panels by ventilating without bleeders
… occurrence. The focus is directed to longwall gobs. The changing gob characteristics, especially the varying degree of consolidation at different parts of a gob as the face moves, is considered. Analytical studies and computer modeling show that bleederless ventilation in retreating panels is …
-
AI-Enabled and Integrated Sensing-Based Beam Management Strategies in Open RAN
… by two use cases from O-RAN: the Grid of Beams (GoB) Optimization and the AI/ML-assisted Beam Selection. For the GoB Optimization use case, a scenario subject to constraints on the use of the full GoB due to overhead during beam selection is considered. An Advantage Actor Critic (A2C) …
-
Development of Potential Remote Coal Mine Fire Response Measures: Use of Multiple Passive Source Tracers and Simulation of High Expansion Foam Flow in Simulated Gob Material
… response methods for a fire in a coal mine gob consist of injection of inert gas and sealing of the mine openings. Injection of high expansion foam into the gob from the surface has potential to improve extinguishment of the fire and reduce the time needed to bring the mine back to an …
-
Bump control design protocol for room-and-pillar retreat mining
… pillars, extracted against an infinitely wide gob area. Tributary area theory was combined with a linear shear angle concept to estimate the loads applied to total extraction pillars adjacent to gob areas. The boundary element code MULSIM/NL was utilized in the development and implementation of …
-
Approaches to Simulation of an Underground Longwall Mine and Implications for Ventilation System Analysis
… technique in the mining industry. However, a gob area, which is a void zone filled with broken rocks after the longwall mining, cannot be simulated in an accurate way with networking modeling. CFD is a powerful tool for modeling different kinds of flows under various situations. However, it …
-
A Study of Mine-Related Seismicity in a Deep Longwall Coal Mine
… class of seismicity occurs in the mined-out "gob" area of the longwall panel at a greater distance behind the moving face. Their occurrence and relation to the mining history, depth of overburden and geology of the roof rocks is a significant interest. Results show that thick overburden due to …
-
CFD modeling of a tailgate ventilation condition in a longwall bleeder system
… a safety risk at any longwall operation. Poor gob caving can lead to insufficient face air quantity with which to dilute methane at the tailgate corner, while a blocking of the tailgate by a roof fall can carry methane-contaminated air from behind the shields back into the face near the …
-
Microseismic Monitoring of a Room and Pillar Retreat Coal Mine in Southwest Virginia
… observe the redistribution of stress and related gob formation throughout the panel's retreat. Expectations for the gob formation were consistent with the distribution of microseismic events. Over 13,000 microseismic events were found in 1.5 months of monitoring. Approximately 2,800 of these …
-
The Ignition of Methane and Coal Dust by Air Compression - The Experimental Proof
When a large area of open gob collapses suddenly, a windblast is produced that can cause considerable damage throughout the infrastructure of a mine. In a few cases, the windblast has been accompanied by ignitions of methane and/or coal dust. Analytical and numerical analyses investigated the …
-
AN IMPROVED ROCK MASS BEHAVIOR NUMERICAL MODEL AND ITS APPLICATIONS TO LONGWALL COAL MINING
… 2) Implement the improved model for predicting gob material behavior using FLAC3D numerical code (most commercial codes do not have a built in model for gob material) and its effects on load transfer into gate entries, 3) Identify mechanisms of instability in setup rooms, 4) Develop alternate 3- …
-
Exploring the molecular signatures of the ligand-receptor-Gi/o protein interactions of adenosine A1 and A3 receptors
… activates Gi1, Gi2 and Gi3 over Goa, Gob and Gz in the presence of agonists. Also, hA1R showed much higher constitutive activity than hA3R in activating all six inhibitory G proteins. To investigate the structural mechanisms underlying this differential preference in activating the …
-
"Beyond the Sparkle" : diversification of mineral-rich economies: The case of Botswana
… of the three themes. The government of Botswana (GoB) must ensure that they develop an enabling environment to incentivise increased export development; they should invest in physical and human capital in order to facilitate private sector growth, and they should set policies and targets to …
-
Advanced Computing and Sensing to Improve Mine Fire Characterization and Response
… to simulate firefighting foam flow through gob areas is proposed and tested using experimental results obtained from a scaled down experimental setup.
-
The Morning After (the night before): Emancipating Spectators in Participatory Live Art
… La Pocha Nostra, Marina Abramović, and Gob Squad. It explores the potentialities and limitations of participation from all sides of the performance border, drawing on my experiences as a performing-spectator, watching-spectator, and as an artist-collaborator with La Pocha Nostra. …
-
Theoretical analysis of bump and airblast events associated with coal mining under strong roofs
… compression model. The presence of fragmented gob materials on the floor greatly influences the pressure and temperature variations after the recompaction of fragmented material commences. Three case studies of airblasts were analyzed, one of which was associated with a mine explosion. The …
-
Infection of two distinct Trichuris sp. genotypes within and among baboon (Papio ursinus) troops on the Cape Peninsula, South Africa
… in a baboon from an unknown troop, while the CP-GOB genotype was observed among five specimens within a baboon from the Groot Olifantsbos troop. Sequence data confirmed the presence of a single genotype in each troop. This study suggests that the genotypes are specific to baboon troops but the …
-
Time-lapse Passive Seismic Velocity Tomography of Longwall Coal Mines: A Comparison of Methods
… a low velocity zone that correlates with the gob is consistently imaged. These features also redistribute with face advance. The US Western II data set was not as densely sampled as the US Western I data set. A low velocity region was consistently present in the gob area and redistributed with …
-
Experimental and Theoretical Studies of Kinetics and Quality Parameters to Determine Spontaneous Combustion Propensity of U.S. Coals
… since they normally occur in inaccessible gob and sealed area. It is also difficult to find the most likely hot point accurately. Admittedly, determination of the propensity for spontaneous combustion before mining activity should be a necessary step in the design of a mine and ventilation …
-
The Measurement of Decomposition Products of Select Gases as an Indicator of a Concealed Mine Fire
… 1. A mined-out area, such as a long-wall gob. 2. A mine area, or entire mine, that has been sealed to extinguish a fire. 3. The interior of pillars in a mine. 4. Abandoned mines. Mined-out areas — gobs — are particularly problematic. The standard practice is to obtain measurements for …
Page 1 of 2