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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 124 for “"ballast"”.
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Railway ballast permeability
Railway ballast serves as a major structural and drainage component of railroad track, but is known to degrade over time. This progressive degradation increases the amount of finer particles within the ballast over time, called fouling material, which decreases its drainage capacity and strength. …
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Electro-disinfection of Ballast Water
… electro-disinfection as a potential secondary ballast water treatment technology. Electricity applied to bacteria laden water produced bactericidal effects, reactive oxygen species and chlorine generation which annihilated bacteria. Evaluation of electro-disinfection experiments showed titanium …
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A study of ballast and ballasting
Thesis (B.S.)--Michigan State College of Agriculture and Applied Science, 1948
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Enhancing Ballast Performance Using Geocell Confinement
… deformation and a lack of stiffness from the ballasted foundation. One general solution for lack of substructure integrity has been confinement, applied through a variety of reinforcement types, including geocell. To investigate the effectiveness of geocell confinement on ballasted …
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Design considerations for segregated ballast tankers
Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Ocean Engineering.
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The ballast resistor : a simple dissipative structure.
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept of Physics.
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Risk-based framework for ballast water safety management
Ballast water has been identified as a major vector for the translocation of Non- Indigenous Invasive Species (NIS) and pathogens across zoogeographical regions and subsequent discharged into recipient port states/regions. This is bound to increase given factors like the globalization of trade and …
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Performance of Geogrid Reinforced Ballast under Dynamic Loading
Railroad ballast consists of open graded crushed stone used as a bed for railroad track to provide stability. It plays a significant role in providing support for the track base and distributing the load to the weaker subgrade below. Ballast also helps with drainage, which is an important factor …
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Machine learning techniques for identifying railroad ballast degradation
Railroad ballast is a layer of uniform sized crushed aggregate particles placed between, below and around the crossties. Railroad ballast transfers the load from crossties to the subgrade layer, provides lateral track stability and facilitates the drainage of water. Repeated traffic loading and …
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Investigation of aggregate properties influencing railroad ballast performance
… goes toward the maintenance and renewal of ballast. Railroad ballast is a uniformly-graded coarse aggregate placed between and immediately underneath the crossties. Large variations in the source properties of new ballast aggregate materials provided by suppliers resulted in the need to …
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Alternative topological approaches to the electronic lamp ballast
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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Variable ballast system design for an unmanned submersible
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1983.
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Piezoelectric Transformer Characterization and Application of Electronic Ballast
… are studied and developed for use in electronic ballasts. By replacing conventional L-C resonant tanks with piezoelectric transformers, inductor-less piezoelectric transformer electronic ballasts have been developed for use in fluorescent lamps. The piezoelectric transformer is a combination of …
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An improved electronic ballast for the fluorescent lamps
The ''charge pump" electronic ballast circuit, which employs a charging capacitor and a high frequency ac source to implement the power factor correction (PFC), has become an attractive topology for ballasting the fluorescent lamps because it eliminates the use of a bulky boost inductor. But the …
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On the shear strength of polyurethane coated railroad ballast
Unbound nature of railroad ballast aggregates causes abrasion and degrada- tion predicaments due to heavy train axle loads. Polyurethane reinforcement of ballast layer is a candidate solution to these problems. However, not many polyurethane reinforcement applications have been studied until the …
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Track behaviour: the importance of the sleeper to ballast interface
… of the mechanical behaviour of the<br/>sleeper/ballast interface, related in particular, to the forces applied by high speed tilting trains on<br/>low radius curves. The research has used literature review, field measurements, and laboratory<br/>experiments on a single sleeper bay of track. …
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Design of Radial Mode Piezoelectric Transformers for Lamp Ballast Applications
… Electronics, LC led to a sample that could fit a ballast application enabling zero voltage switching (ZVS) for the semiconductors without the use of any external inductance. In the ballast circuit, the piezoelectric transformer is used to replace the conventional inductor-capacitor resonant tank …
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Three Dimensional Passive Integrated Electronic Ballast for Low Wattage HID Lamps
… avoided by the use of more efficient lamps and ballasts [1]. High intensity discharge (HID) lamps, one category of gas discharge lamp, have been widely used in both commercial and residential lighting applications due to their merits of high efficacy, long life, compact size and good color …
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Discrete Element Modeling of Railway Ballast for Studying Railroad Tamping Operation
… of Discrete Element Model (DEM) of railway ballast for the purpose of studying the behavior of ballast particles during tamping is addressed in a simulation study, with the goal of optimizing the railroad tamping operation. A comprehensive literature review of applicability of DEM techniques …
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