Engineering Commons^™

Aeroelastic Optimization Of Sounding Rocket Fins, Joseph R. Simmons Iii

Theses and Dissertations

This research effort develops a multidisciplinary design tool to optimize sounding rocket fin geometries that minimize the mass of the fins while maintaining aerodynamic performance. This research grew out of a design problem experienced by the US Air Force Academy's Falcon LAUNCH program. The Falcon LAUNCH program is a senior design capstone project during which Air Force Academy cadets design, build and fly a sounding rocket over the course of an academic year. In the Spring of 2007, the Falcon LAUNCH V vehicle experienced a catastrophic failure when three of its four fins sheared off due to flutter. When the …

Performance And Operability Of A Dual Cavity Flame Holder In A Supersonic Combustor, Mackenzie J. Collatz

Theses and Dissertations

The current generation of hydrocarbon fueled scramjet combustors typically requires a flame holding device to facilitate flame ignition and stable combustion. The amount of time available for fuel injection, fuel-air mixing, and combustion is very short, on the order of 1 millisecond. This short dwell time, along with the relatively long ignition delay times of hydrocarbon fuels, makes the flow path and flame holder design extremely important. This study investigates the performance and operability of using a symmetric dual cavity flame holder flow path to stabilize and enhance supersonic combustion. Testing of this flow path configuration, as well as a …

An Efficient And Effective Implementation Of The Trust System For Power Grid Compartmentalization, Juan M. Carlos Gonzalez

Theses and Dissertations

As utility companies develop and incorporate new technologies, such as moving to utility Internet technology based architecture and standard; it is crucial that we do so with history in mind. We know that traditional utility protection and control systems were not designed with security in their top priorities. This presents a danger in an environment where near real-time responses are required to ensure safe operations. As a consequence, system security becomes a burden to the system rather than necessary protection. Unfortunately, technology implementation is not the only concern. The number of utility privately-owned companies has multiplied as the market has …

Investigation Of Additives For Use In Electroless Plating Solutions For Fabrication Of Nanowires, Elliott J. Bird

Theses and Dissertations

This study focused on improvement of electroless plating methods by use of particular bath additives. The techniques developed here can enable us to plate very thin layers selectively on a nonconductive substrate and thus create metallized features on a nanoscale. Through the development of such bottom-up techniques this work contributes a key technology to achieving self-assembled nanocircuits. The use of additives in an electroless plating environment can modify the barriers to nucleation (or seeding) and growth. Two additives, namely 3-mercapto-1-propanesulfonic Acid (MPS) and 1,3-propanedisulfonic acid (PDS), notably increased the selectivity of electroless metallization on chemically modified surfaces, which can be …

Final Report For The Link Energy Fellowship, A. Joe Shaw

Link Foundation Energy Fellowship Reports

A sustainable energy future is critical for environmental and strategic reasons. Fossil fuel use has increased greenhouse gas emissions, and continued consumption could adversely change global climate. In addition, the United States must rely on foreign petroleum suppliers, leading to unfavorable trade deficits, instability, and conflict.1 One leading alternative to petroleum used for transportation is ethanol derived from cellulosic biomass.2 A major barrier for biological-based biomass conversion is a cost effective method of releasing sugars from recalcitrant cellulosic biomass by enzymatic hydrolysis. Thermophilic, anaerobic bacteria offer a potential solution, as they produce efficient native hydrolytic enzymes.3 However, all thermophilic bacteria …

Early-Age Re-Entry Under Fresh Fibre Reinforced Shotcrete, E. Stefan Bernard

Shotcrete for Underground Support XI

Fibre Reinforced Shotcrete (FRS) is now used together with bolts for ground support in almost every underground metalliferous mine in Australia. Safety and economy have been the primary factors driving the widespread adoption of this system of ground support. Thickness, strength, and toughness requirements for long-term stabilization of hard rock ground are relatively well understood for the majority of ground conditions, but minimum safe re-entry times following spraying remain unclear. This issue has therefore been addressed through a series of experimental and theoretical investigations that have assessed common ground conditions in metalliferous mines and compared this to the local load …

Determination Of Energy Absorption Capabilities Of Large Scale Shotcrete Panels, Ellen C. Morton, Ernesto Villaescusa, Alan G. Thompson

Shotcrete for Underground Support XI

The Western Australian School of Mines (WASM) has developed a facility for the static testing of full scale ground support elements. The test facility consists of several stiff steel frames used to support the sample and a screw feed jack is used to load the sample. A large scale punch test method has been developed to evaluate various shotcrete mix designs at different curing times. The shotcrete is sprayed on to a sandstone substrate containing an isolated disc that is centrally located. The test sample is placed on to the sample frame and restrained on all sides. The disc is …

Construction Placement, Hardened Properties And Durability Of Shotcrete With Highly Functional Fly Ash, Kunihiro Yuno, Chikanori Hashimoto, Mitsuhiro Ishii, Hiroyuki Mizuguchi

Shotcrete for Underground Support XI

Shikoku Electric Power Co., Inc. has developed the technology to manufacture a brand name “Finash” about 12 years ago, by sorting and classifying coal ash generated in coal fired power plants. “Finash” is highly functional fly ash (HFA) is produced by removing irregular coarse particles. It is important for the production of HFA to minimize the variation in quality of coal ash with sophisticated classification technique and extracting good-quality spherical fine particles. The specific surface of HFA is more than 5000 cm2/g. It is now widely utilized as concrete admixture for general civil engineering structures and buildings in Japan.

When …

X-Ray Tomographie Of Steel Fibre Reinforced Shotcrete (Sfrs), Gerhard Pittino, Robert Galler

Shotcrete for Underground Support XI

X-ray tomography is a commonly used diagnostic method in medicine. Its use has also spread into the field of engineering. The most important application is the non-destructive testing. The composite material steel fibre reinforced shotcrete is applied widespreadly in the geotechnique. The knowledge about the orientation of the steel fibres in the concrete is of decisive importance for modeling the mechanical behaviour. The poster shows the way of sampling about the computer tomography (Voxel model) up to the statistical evaluation of the fibre orientation.

Experiences With Polymer-Modified Shotcrete, Gerhard Pittino, Robert Galler, Klaus Bonin, Jürgen Bezler

Shotcrete for Underground Support XI

Adhesive mortar for tiles can be significantly improved by modification. Why should sprayed concrete not benefit similarly for various applications? This question has been investigated through large-scale tests in a tunnel cross passage, in an access gallery of a salt mine and in a mining gravity shaft. In-situ tests are necessary because the sprayed concrete mix and the process engineering have a significant influence on the quality of the sprayed concrete. The fresh concrete properties and the properties of the sprayed concrete like early strength development, the ability to creep, adhesion, density and resistance to abrasion are all investigated.

Application Of Blended Cement In Shotcrete To, Atsumu Ishida, Akitoshi Araki, Kenji Yamamoto, Minoru Morioka, Akihiro Hori

Shotcrete for Underground Support XI

The application of blended cements in shotcrete is investigated to reduce the environmental burden. Reduction of the environmental burden and meeting the required properties of quick setting and strength development are achieved using blended cements with blast furnace slag and a powder accelerator with a main component of calcium sulfo-aluminate. The powder accelerator is hydro-reactive and promotes quick setting and strength development in shotcrete. The reduced environmental burden of shotcrete with blended cement and powder accelerator are calculated.

Recent Experiences Using Shotcrete At Underground Laboratory Facilities, Christopher Laughton Phd, Pe

Shotcrete for Underground Support XI

The paper discusses the use of shotcrete linings at underground laboratories, and details the application of shotcrete and water control systems on the Neutrinos at Main Injector project, located in Illinois, USA. The paper also proposes guidelines for the use of shotcrete at the Deep Underground Science and Engineering Laboratory, South Dakota, USA.

Shotcrete In Tunnelling In Frozen Ground, Ludger Speier, Heiner Klönne

Shotcrete for Underground Support XI

The use of shotcrete in tunnelling in frozen ground will be presented for an actual project. There are specific demands on the mixture of shotcrete and the construction because of the frozen ground. The basics for the design especially the safety concept and the experiences made during construction will be presented.

Yet Another Way Of Calculating Stresses In A Shotcrete Lining, Bernd Moritz Dipl.-Ing.Dr. Techn., Markus Brandtner Ing.

Shotcrete for Underground Support XI

A complex rheological model has been used recently at several Austrian tunnel job sites to determine stresses in a shotcrete lining. The raw data are from displacements measurements at the lining contour.

The analysis uses a material model based on a thermo-chemo-mechanical approach. This paper gives a short review of the theoretical background and two case studies. The first one considers a tunnel with top heading/bench and invert excavation and the second one a tunnel with a more complex structure with side galleries and core excavation.

Activities Of The Ita Working Group On Sprayed Concrete Use, Tarcisio B. Celestino, Atsumu Ishida

Shotcrete for Underground Support XI

This paper describes the activities of the International Tunnelling and Underground Space Association (ITA) Working Group 12 on Sprayed Concrete Use. The Working Group has carried out tasks with the purpose of promoting information exchange between National Groups and planning, coordinating and releasing the results of testing programs in order to advance the state-of-the-art of sprayed concrete use for underground support. The intention of the Working Group is to explore and develop the idea that the rational use of sprayed concrete improves possibilities for design and construction of new underground works.

Conference Program, Felix Amberg

Shotcrete for Underground Support XI

No abstract provided.

Cost Efficient Waterproof Tunnel Linings, Knut F. Garshol

Shotcrete for Underground Support XI

The last few years, several projects have been successfully lined by sprayed concrete with an embedded double-bonded spray-applied membrane. This composite single shell liner offers significant reduction of total project cost and construction time. Especially in drill and blast tunneling major cost savings are linked to reduced consumption of concrete materials when comparing with the traditional system with sheet membrane and cast in-situ concrete.

Design Of Fibre Reinforced Shotcrete Linings With Macro-Synthetic Fibres, E. Stefan Bernard

Shotcrete for Underground Support XI

Fibre Reinforced Shotcrete (FRS) reinforced with macro-synthetic fibres has now been used to stabilize ground in underground mines and tunnels, and for slope stabilization, for over 10 years. Experience has demonstrated that macro-synthetic fibres are capable of exhibiting very high levels of performance and are a highly effective form of reinforcement for both temporary and permanent ground support. Engineering data also exists showing that macro-synthetic fibres excel with regard to corrosion resistance and embrittlement in shotcrete, and are very effective in ground subject to high deformation. Despite this, the design of FRS linings using this type of reinforcement lags behind …

Understanding The Pumpability Of Concrete, Marc Jolin, Dennis Burns, Benoît Bissonnette, Frédéric Gagnon, Louis-Samuel Bolduc

Shotcrete for Underground Support XI

With the increasing need for underground opening's support and the increasing knowledge available today in concrete technology, shotcreting, and particularly the wet-mix process, is in great demand. Successful pumping operations however usually require a certain amount of experience. On the one hand, engineers design a mixture with high workability for ease of transport through the hose system, and on the other hand, they strive for a mixture that is relatively stiff, adhesive, and cohesive to achieve good adhesion and build-up on vertical or overhead shooting surfaces. This article presents some of the most recent research on the understanding of the …

Development And Application Of Stress Controllers – System Honeycomb – In Modern Tunnelling, Rudi Podjadtke Dipl.-Ing.

Shotcrete for Underground Support XI

After a short retrospect on possible elasticity the intended purpose of stress controllers as rock support elements in shotcrete construction is described. Different types of stress controllers are briefly explained. The successful development as well as the technical versions of the stress controller type - HONEYCOMB - is explained in detail.

Experiences in first use at Tauerntunnel with its system components are presented. Further possible fields of application and developments are elaborated.

Preface, Felix Amberg

Shotcrete for Underground Support XI

No abstract provided.

Non-Linear, Elastic - Plastic Response Of Steel Fibre Reinforced Shotcrete To Uniaxial And Triaxial Compression Testing, Hla Aye Saw, Ernesto Villaescusa, Christopher R. Windsor, Alan G. Thompson

Shotcrete for Underground Support XI

Understanding the complete stress-strain behavior of shotcrete is extremely important in ground support design; especially in cases where large deformations are expected such as around mine excavations at great depth. The application of non-linear numerical modeling to mining industry problems has increased in recent years. More realistic stress-strain response and failure criteria in complex plasticity models are also being used in the design of the larger, deeper mines. One of the factors to improve the reliability of numerical modeling is to properly define geotechnical parameters for both the rock mass and shotcrete surface support. Uniaxial and triaxial compression tests on …

Tunnelling In Squeezing And Swelling Rock By Using High Deformable Concrete Elements, Patrick Steiner

Shotcrete for Underground Support XI

The poster shows experience on construction using hiDCon-Elements (High Deformable Concrete) in several tunnels. The yieldable concrete elements for the application in squeezing rock conditions have a beam shape and are longitudinally fixed to the excavation surface at different locations. The elements are incorporated into the tunnel lining when the shotcrete is added. If the lining is subjected to a radial rock pressure of the designed value the normal force in the lining will cause the hiDCon-Elements to yield thus preventing the shotcrete from being overstressed. Application of these yieldable concrete elements in strongly swelling rock is achieved by using …

Case Histories Using Synthetic Fiber Reinforced Concrete, Clifford N. Macdonald Faci, Michael L. Ballou, Daniel T. Biddle

Shotcrete for Underground Support XI

Synthetic fiber reinforced concrete has been used in shotcrete for many years. This paper discusses select project case histories from around the world. The discussion focuses on why fibers are used and explains how there are many benefits, advantages, and features regarding the choice of fibers. Also discussed is why and how the fibers affect the overall project performance, schedule, costs, and construct-ability. Further discussion shows that the fiber choice is in the details. The best fiber choice must meet certain project criteria established by all the decision makers involved in the project. Lastly, the versatility in the use of …

Technical And Commercial Evaluation Of Modified Shotcrete In Tunnel Construction, Erik Iglesias Dr.-Ing., Tu Volker Wetzig Dipl.-Ing., Jürgen Bezler, Mareike Xia Dipl.-Ing.

Shotcrete for Underground Support XI

Rebound is a significant factor when evaluating the quality and performance of a construction site using shotcrete. Rebound modifies the characteristics of shotcrete and must be disposed of. Thus a reduction in rebound becomes both a technical and a commercial objective.

Based on many years of experience with polymers in mortar applications, different polymer modified systems were developed for shotcrete applications and investigated in extensive full size trials. The investigations fully confirmed expectations as regards a reduction in rebound. At the same time the recently developed polymer has a retardant effect, giving the concrete other improved properties. Parallel to the …

Drop Impact Dynamic Response Study Of Jedec Jesd22-B111 Test Board, Jianbiao Pan, Michael Krist, Andrew Farris, Nicolas Vickers

Honors Undergraduate Research Journal

No abstract provided.

Slides: Groundwater Law And Administration: From Conflict To Reform, Michael A. Gheleta

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Michael A. Gheleta, Brownstein Hyatt Farber Schreck LLP, Denver, CO

14 slides

Slides: Modifying Prior Appropriation: The Spectrum Of Experiences, Adam Schempp

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Adam Schempp, Environmental Law Institute, Washington, DC

12 slides

Slides: Next Evolutionary Steps In State Instream Flow Programs, Lawrence J. Macdonnell

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Lawrence J. MacDonnell, attorney and consultant, Boulder, CO

27 slides

Slides: Rethinking Western Water Law: Restoring The Public Interest In Western Water Law, Mark Squillace

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Mark Squillace, Director, Natural Resources Law Center, University of Colorado Law School

20 slides