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Articles 451 - 480 of 1187

Full-Text Articles in Mining Engineering

Interactive Learning Tools: Animating Statics, Nancy Hubing, David B. Oglesby, Timothy A. Philpot, Vikas Yellamraju, Richard H. Hall, Ralph E. Flori Dec 2002

Interactive Learning Tools: Animating Statics, Nancy Hubing, David B. Oglesby, Timothy A. Philpot, Vikas Yellamraju, Richard H. Hall, Ralph E. Flori

Business and Information Technology Faculty Research & Creative Works

Computer-Based Modules for Engineering Instruction Must Be Concise, Flexible, Educational and Engaging in Order to Effectively Supplement Traditional Classroom Teaching Tools. a Computer Example that Takes More Time Than a Chalkboard Presentation is Not Likely to Be Useful in Today's Engineering Classroom. Flexible Navigation is Necessary So that the Instructor Can Quickly and Easily Respond to Student Questions. Useful Modules Must Also Improve Problem-Solving Skills or Clarify Troublesome Concepts in Order to Be Considered Worthy of Inclusion in the Limited Class Time Available. Finally, and Perhaps Most Importantly, Effective Computer-Based Modules Must Meet the Challenge of Holding the Student's Attention. …

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The Causes Of Armature Surface Fracturing Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey Jan 2002

The Causes Of Armature Surface Fracturing Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

Aluminum and copper tubes filled with explosive were tested during this study of high strain rate effects, as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla, directly affecting the understanding of flux cutoff and high strain-rate changes in generator armatures. Longitudinal cracks characteristically developed in the outer surface of armatures at a smaller expansion ratio than predicted. These cracks occurred within two diameters of the detonator end of the armature but did not extend when the tubing expanded under explosive pressurization. Such cracks appear to cause magnetic flux cutoff, and flux losses seriously affect energy conversion …

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Apparatus For Comminution Of Solid Materials Using A Processor-Controlled Liquid Jet, Marian Mazurkiewicz Jan 2002

Apparatus For Comminution Of Solid Materials Using A Processor-Controlled Liquid Jet, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

The present invention is directed to a tire comminution apparatus that is of simple construction and that can be operated without excessive maintenance. According to the present invention, a vehicle tire of any size or composition can be comminuted with essentially the same comminution apparatus. The comminution apparatus includes a freely moving lance with a nozzle for transforming a liquid into a high velocity liquid jet. The lance is positioned and controlled such that the liquid jet impacts the tire thereby separating it into its component parts. The comminution apparatus may be computer controlled.

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Graphite Platelet Nanostructures, Marian Mazurkiewicz Jan 2002

Graphite Platelet Nanostructures, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

Separated graphite nanostructures are formed of thin graphite platelets having an aspect ratio of at least 1,500:1. The platelets have an angular geometric structure and may be fully independent from an original graphite particle, or partially attached to the particle. The graphite platelets have an average thickness in the range of 1-100 nm. The graphite nanostructures are created from synthetic or natural graphite using a high-pressure mill. Fluid jets of the high-pressure flaking mill cause fluid to enter the tip of cracks in the graphite particles, which creates tension at the tip. This tension causes the cracks to propagate along …

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Design Of A Hypersonic Waterjet Apparatus Driven By High Explosives, B. L. Weeks, J. Klosterman, Paul Nicholas Worsey Aug 2001

Design Of A Hypersonic Waterjet Apparatus Driven By High Explosives, B. L. Weeks, J. Klosterman, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place.

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Effects Of Defects On Armatures Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey, Mark F. C. Schmidt Jan 2001

Effects Of Defects On Armatures Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey, Mark F. C. Schmidt

Mining Engineering Faculty Research & Creative Works

Tubes of aluminum and copper filled with C-4 high-explosive were tested during this study of the effects of explosive flaws and voids, their sizes and locations, and of the effects of armature machining tolerances on the expansion characteristics of armatures within helical flux-compression generators. Flaws and voids were introduced into the explosive fill of 6061-T6 aluminum armatures during assembly. The defects were located along the major axis of the fill, midway between the major axis and the explosive/armature interface, and at the interface. The resulting effects on armature expansion were recorded by high-speed framing camera, intensified charge-coupled display (ICCD) photography …

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Surface Fracturing Of Armatures Within Helical Flux-Compression Generators, Paul Nicholas Worsey, Jason Baird Jan 2001

Surface Fracturing Of Armatures Within Helical Flux-Compression Generators, Paul Nicholas Worsey, Jason Baird

Mining Engineering Faculty Research & Creative Works

Tubes of aluminum and of copper filled with C-4 high-explosive were tested during this study of high strain rate effects within thin metallic structures performed as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla. Focusing on the stresses within a relatively thin metallic structure when brisant explosives abutting the structure are detonated, this study directly affects the understanding of flux cutoff and high strain-rate resistivity changes in an expanding armature. The detonation wave is compressive, and the shock waves resulting from its transmission into a thin metallic structure cause both compressive and tensile regions, posing an …

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Method Of Creating Ultra-Fine Particles Of Materials Using A High-Pressure Mill, Marian Mazurkiewicz Jan 2001

Method Of Creating Ultra-Fine Particles Of Materials Using A High-Pressure Mill, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

A method for creating ultra-fine particles of material using a high-pressure mill is described. The method includes placing a material in a first chamber and subjecting the material to a high-pressure liquid jet to divide it into particles. These particles are then transferred to a second chamber in which they are subjected to cavitation to further divide the particles into relatively smaller particles. These relatively smaller particles are then transferred to a third chamber, in which the particles collide with a collider to still further divide them into ultra-fine particles of the material. The mill of the present invention includes …

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Optical Diagnostics On Helical Flux Compression Generators, A. A. Neuber, J. C. Dickens, H. Krompholz, M. F. C. Schmidt, Jason Baird, Paul Nicholas Worsey, M. Kristiansen Oct 2000

Optical Diagnostics On Helical Flux Compression Generators, A. A. Neuber, J. C. Dickens, H. Krompholz, M. F. C. Schmidt, Jason Baird, Paul Nicholas Worsey, M. Kristiansen

Mining Engineering Faculty Research & Creative Works

Explosively driven magnetic flux compression (MFC) has been object of research for more than three decades. Actual interest in the basic physical picture of flux compression has been heightened by a newly started Department of Defense (DoD) Multi-University Research Initiative. The emphasis is on helical flux compression generators comprising a hollow cylindrical metal liner filled with high explosives and at least one helical coil surrounding the liner. After the application of a seed current, magnetic flux is trapped and high current is generated by moving, i.e., expanding, the liner explosively along the winding of the helical coil. Several key factors …

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Integration Of Csab And Abet, Lee W. Saperstein, Kenneth Martin, Doris K. Lidtke Jan 2000

Integration Of Csab And Abet, Lee W. Saperstein, Kenneth Martin, Doris K. Lidtke

Mining Engineering Faculty Research & Creative Works

The Accreditation Board for Engineering and Technology, Inc. (ABET) and the Computing Sciences Accreditation Board (CSAB) signed a Memorandum of Agreement in November 1998 to integrate CSAB''s accreditation services with ABET, with a transition time of approximately two years. During the interim period, the operations of the Computer Science Accreditation Commission (CSAC) are contracted by CSAB to ABET. A committee with CSAC, CSAB, and ABET representation is working to set up the new commission for accrediting programs in the computing sciences. This new commission will probably be called the Computing Accreditation Commission (CAC). Other activities are underway to try to …

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Method For Introducing Substances Into Living Cells And Tissues, Marian Mazurkiewicz Jan 2000

Method For Introducing Substances Into Living Cells And Tissues, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

A method of introducing a biological substance into living target cells, the method comprising dispersing a liquid containing the biological substance into microdroplets and propelling the microdroplets toward to the target cells.

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The Practice Of Ventilation Planning Half A Century Ago, Rudolf E. Greuer Jun 1999

The Practice Of Ventilation Planning Half A Century Ago, Rudolf E. Greuer

U.S. Mine Ventilation Symposium

This is the description of ventilation planning conducted by the author in 1952 as his thesis for the German degree of Dipl.-Ing. Since the problems have not changed, most of the work done is not much different from what one would do today. Even the tools have remained the same, except for the computers, which were not around yet. To compensate for this, certain planning techniques were developed which are now in danger of being forgotten.

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Cfd Applications In Tunnel Ventilation Analysis, Richard E. Ray Jr., Abdelgbani Zigh Jun 1999

Cfd Applications In Tunnel Ventilation Analysis, Richard E. Ray Jr., Abdelgbani Zigh

U.S. Mine Ventilation Symposium

Longitudinal ventilation systems in transit and rail tunnels are typically analyzed by one dimensional ventilation network simulation models, such as the Subway Environment Simulation (SES) program. However, in recent years computational fluid dynamics (CFD) modeling has been utilized in conjunction with one-dimensional ventilation network programs to study ventilation systems for large volume spaces such as transit stations and rail overbuilds, as well as for vehicular tunnels. CFD uses numerical methods to simulate complex fluid flow phenomena in three dimensions to predict the distribution of velocity, pressure, temperature, concentration, and other relevant variables throughout the volume. This paper presents an overview …

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Three Underground Coal Mine Explosions — Twenty Miners Killed — One Reason, Andrzej M. Wala, Jason R. Stoltz Jun 1999

Three Underground Coal Mine Explosions — Twenty Miners Killed — One Reason, Andrzej M. Wala, Jason R. Stoltz

U.S. Mine Ventilation Symposium

Three mine explosions which occurred in the 1980s (1983 - McClure No. 1 Mine, Virginia; 1984 - Greenwich Collieries No. 1 Mine, Pennsylvania; and 1989- Pyro No.9 Slope Williams Station Mine, Kentucky) cost twenty lives. The authors, by investigating these three cases, found a common ventilation problem. This problem was the misunderstanding of the diagonal connections in the mine ventilation system (MVS). Based on the findings from these investigations, the authors explain the importance of diagonal connections in a MVS and discuss other factors that affected safety.

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On Criteria Of Stability Of Fans Operating In Parallel, Jerzy Krawczyk Jun 1999

On Criteria Of Stability Of Fans Operating In Parallel, Jerzy Krawczyk

U.S. Mine Ventilation Symposium

Ventilation systems with fans operating in parallel may have multiple operating points. The submitted paper presents a method which enables to reduce the number of points which should be taken into consideration. The concepts of a fan system containing: the fan, inlet duct, regulation door subsystem and its total characteristics were introduced. The analysis of local stability of equilibrium points of the system of ordinary differential equations describing unsteady incompressible flow in a simplified network ventilated by 2 fans in parallel leads to formulation of a simple condition of stability. For fans operating in parallel this condition refers to the …

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Optimization Of The Ventilation System At Kidd Mine Of Falcon Bridge Limited, Josef Sedlacek Jun 1999

Optimization Of The Ventilation System At Kidd Mine Of Falcon Bridge Limited, Josef Sedlacek

U.S. Mine Ventilation Symposium

Kidd Mine is the single largest producing base metal mine of Falconbridge Limited. Approximately 3 million tonnes of zinc-copper ore is produced annually. The present ventilation system, designed some 30 years ago, uses a multitude of intake and exhaust fans, in a series-parallel configuration, to move 925 m3/s (2,000,000 cfm) through the mine. The system, owing to the ever increasing depth of mining, has reached its limitation and has become cumbersome to maintain. It was recognized that with the mine progressing from the original depth of 855 m (2800 ft) to the current depth of 2070 m (6800 …

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Water Injection In Longwall Top-Coal Caving Face In China, Zhang Yong, Fu Gui Jun 1999

Water Injection In Longwall Top-Coal Caving Face In China, Zhang Yong, Fu Gui

U.S. Mine Ventilation Symposium

This paper discussed the means of improving dust control efficiency using water injection. At first, the authors point out that internal water has effect on dust control. The objective of water injection is to increase the amount of internal water. Secondly, by analyzing the development trend of crack in top-coal, proper water injection station and boleholes can be determined for dust control.

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Recovery Of Methane From The Abandoned Golden Eagle Mine Property, Kenton L. Hupp, Carol Bibler, Raymond C. Pilcher Jun 1999

Recovery Of Methane From The Abandoned Golden Eagle Mine Property, Kenton L. Hupp, Carol Bibler, Raymond C. Pilcher

U.S. Mine Ventilation Symposium

The abandoned Golden Eagle underground coal mine in Colorado contains gassy coals from which Stroud Oil Properties, Inc. (Stroud) has been recovering gas since 1996. The mine closed permanently in 1996, and during its operation drained methane from gob and ventilation boreholes. Stroud currently produces about 1.8 million cubic feet of near pipeline quality gas per day from six of these boreholes. Although the project has proven successful, gas recovery has been challenging because of low bottom hole pressure and variable borehole performance. Wellhead compressors are required to boost gas pressure for delivery to the main plant. Connecting additional boreholes …

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Methane Drainage At The Minerales Monclova Mines In The Sabinas Coal Basin, Coahuila, Mexico, Daniel J. Brunner, Jose Ruben Ponce Jun 1999

Methane Drainage At The Minerales Monclova Mines In The Sabinas Coal Basin, Coahuila, Mexico, Daniel J. Brunner, Jose Ruben Ponce

U.S. Mine Ventilation Symposium

Minerales Monclova S.A. De C.V. (MIMOSA) operates five underground longwall mines in the Gassy Los Olmos Coals of the Sabinas Basin in the state of Coahuila in Northern Mexico. Because of high in-situ gas contents and high cleat and natural fracture permeability, MIMOSA has had to incorporate a system of methane drainage in advance of mining in order to safely and cost effectively exploit their reserves. In the early 1990s Resource Enterprises (REI) conducted reservoir characterization tests, numerical simulations, and Coal Mine Methane (CMM) production tests at a nearby mine property in the same basin. Using this information REI approached …

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Proposed Regulation On Diesel Particulate Matter In Underground Coal Mines, Thomas F. Tomb Jun 1999

Proposed Regulation On Diesel Particulate Matter In Underground Coal Mines, Thomas F. Tomb

U.S. Mine Ventilation Symposium

The Mine Safety and Health Administration published a proposed rule for underground coal mines that use diesel-powered equipment. The proposed rule, published April 9, 1998, would establish new health standards. These new standards would reduce the risks to miners of serious health hazards that are associated with exposure to high concentrations of diesel particulate matter (dpm). The proposed rule would require that mine operators install and maintain high efficiency filtration systems on the most polluting types of diesel-powered equipment. The rule would also require that miners be trained about the hazards of dpm exposure. This paper reviews the requirements of …

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Committees, Multiple Members Jun 1999

Committees, Multiple Members

U.S. Mine Ventilation Symposium

No abstract provided.

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Published Proceedings Of The Previous Mine Ventilation Symposia, Multiple Authors Jun 1999

Published Proceedings Of The Previous Mine Ventilation Symposia, Multiple Authors

U.S. Mine Ventilation Symposium

No abstract provided.

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Cfd Analysis Of Mine Fire Smoke Spread And Reverse Flow Conditions, J. C. Edwards, C. C. Hwang Jun 1999

Cfd Analysis Of Mine Fire Smoke Spread And Reverse Flow Conditions, J. C. Edwards, C. C. Hwang

U.S. Mine Ventilation Symposium

A Computational Fluid Dynamics (CFD) program was used to model buoyancy induced Product-Of-Combustion (POC) spread from experimental fires in the National Institute For Occupational Safety And Health (NIOSH), Pittsburgh Research Laboratory (PRL), safety research coal mine. In one application, the CFD program was used to predict spread from fires in an entry under zero airflow conditions. At a location, 0.41 m below the entry's roof at a distance of 30 m from the fire, the measured smoke spread rates were 0.093 and 0.23 m/s for a 30 and a 296 kw fire, respectively. The CFD program predicted spread rates of …

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Theoretical Analysis Of Jet Fan Performance Using Momentum And Energy Considerations, Kuda R. Mutama, Allan E. Hall Jun 1999

Theoretical Analysis Of Jet Fan Performance Using Momentum And Energy Considerations, Kuda R. Mutama, Allan E. Hall

U.S. Mine Ventilation Symposium

Jet fans or ductless fans have been analyzed using momentum and energy considerations. This analysis is necessary for the mechanisms of mixing between the jet primary flow and the secondary or induced stream to be understood. In each case it is possible to predict performance in terms of pressure, flow ratios and hence the percentage mechanical efficiency of the whole system using equations derived from momentum and energy principles. The analysis given is suitable for situations where jet fans are utilized as area boosters in a mine ventilation system and in longitudinal vehicular tunnel ventilation. The energy and momentum equations …

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Optimization Of Main Exhaust Fan Systems At Battle Mountain Canada Ltd., Golden Giant Mine, László Götz, Euler De Souza Jun 1999

Optimization Of Main Exhaust Fan Systems At Battle Mountain Canada Ltd., Golden Giant Mine, László Götz, Euler De Souza

U.S. Mine Ventilation Symposium

In 1997, production needs required that the exhaust conditions at the Golden Giant Mine be maximized. One of the principal exhaust raises, the West Return Air Raise #1, designed to handle some 189 m3/s (400,000 cfm) but operating at 102 m3/s (216,000 cfm), was a primary candidate for optimization. This paper describes the major design changes and installation modifications carried out at this surface fan installation. The new installation not only outperformed the design expectations but also achieved the new mine exhaust requirements.

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A Comparison Of Air Leakage Prediction Techniques For Auxiliary Ventilation Ducting Systems, A. D. Stewart Gillies, Hsin Wei Wu Jun 1999

A Comparison Of Air Leakage Prediction Techniques For Auxiliary Ventilation Ducting Systems, A. D. Stewart Gillies, Hsin Wei Wu

U.S. Mine Ventilation Symposium

This paper briefly reviews prediction techniques for determination of leakage and friction along auxiliary ventilation ducting systems. In order to compare various prediction techniques that have been developed over the past, a macroscopic investigation of air leakage and friction resistance of auxiliary ventilation ducting systems has been undertaken. Measurements were conducted on 450 and 915 mm diameter fabric ducting over 100 m duct length to determine frictional resistances and the extent of leakage. Due to the high degree of accuracy required and the large volume of data that needed to be collected, electronic pressure transducers were used with computer for …

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Controlled Recirculation In Deep South African Gold Mines, Mark Butterworth Jun 1999

Controlled Recirculation In Deep South African Gold Mines, Mark Butterworth

U.S. Mine Ventilation Symposium

Despite the many advantages and potential benefits of using controlled recirculation in Deep South African gold mines the strategy has found little favour. Indeed, controlled recirculation of air is at present rarely considered as an option in the planning and implementation of these underground ventilation systems. This paper broadly examines controlled recirculation, the benefits and advantages that could accrue from its use, reasons that may detract from its use and some solutions for addressing shortcomings. A brief historical review of controlled recirculation in the context of the South African gold mining industry is given. The advantages, which could result from …

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Mining Safety Of Longwall Top-Coal Caving In China, Jian Wu, Yueping Qin, Minghua Zhai Jun 1999

Mining Safety Of Longwall Top-Coal Caving In China, Jian Wu, Yueping Qin, Minghua Zhai

U.S. Mine Ventilation Symposium

Longwall top-coal caving technology has developed rapidly in China, in recent years. The application of longwall top-coal caving can double both the productivity and the efficiency of a working face and reduce the cost of production by 30 to 40%. Using standard longwall equipment, annual production can reach 3 million metric tons (Mt), and a maximum of 4.1 Mt has been obtained; many top-coal caving longwall working faces can obtain 200 tons per man-shift. Longwall top-coal caving is distinctly different from slice mining in thicken seam. Concerns of safety and productivity for this method have been raised in recent years. …

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Ventilating The Box Cut Of A Two-Pass 40-Ft Extended Cut, Edward D. Thimons, Charles D. Taylor, Jeanne A. Zimmer Jun 1999

Ventilating The Box Cut Of A Two-Pass 40-Ft Extended Cut, Edward D. Thimons, Charles D. Taylor, Jeanne A. Zimmer

U.S. Mine Ventilation Symposium

On a continuous miner coal face methane concentrations are affected by the quantity of fresh intake air reaching the face. When mining the box cut on a 12.2-m (40-ft) two-pass extended cut face, the continuous miner is always at the point of deepest penetration, and operation of the machine-mounted dust scrubber and water spray system improve the flow of fresh air to the end of the box cut. However, when the continuous miner leaves the box cut to begin cutting the 40-ft slab, little is known about how much ventilation air reaches the end of the box cut. The Pittsburgh …

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Dust Control At Yucca Mountain Project, Fred Kissell, Romeo Jurani, Ralph Dresel, Charles Reaux Jun 1999

Dust Control At Yucca Mountain Project, Fred Kissell, Romeo Jurani, Ralph Dresel, Charles Reaux

U.S. Mine Ventilation Symposium

This report describes actions taken to control silica dust at the Yucca Mountain Exploratory Studies Facility, a tunnel located in Southern Nevada that is part of a scientific program to determine site suitability for a potential nuclear waste repository. The rock is a volcanic tuff containing significant percentages of both quartz and cristobalite. Water use for dust control was limited because of scientific test requirements, and this limitation made dust control a difficult task. Results are reported for two drifts, called the Main Loop Drift and the Cross Drift. In the Main Loop Drift, dust surveys and tracer gas tests …

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