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Full-Text Articles in Applied Mechanics
A Single-Stage Passive Vibration Isolation System For Scanning Tunneling Microscopy, Toan T. Le
A Single-Stage Passive Vibration Isolation System For Scanning Tunneling Microscopy, Toan T. Le
Master's Theses
Scanning Tunneling Microscopy (STM) uses quantum tunneling effect to study the surfaces of materials on an atomic scale. Since the probe of the microscope is on the order of nanometers away from the surface, the device is prone to noises due to vibrations from the surroundings. To minimize the random noises and floor vibrations, passive vibration isolation is a commonly used technique due to its low cost and simpler design compared to active vibration isolation, especially when the entire vibration isolation system (VIS) stays inside an Ultra High Vacuum (UHV) environment. This research aims to analyze and build a single-stage …
Design Of Structural Stand For High-Precision Optics Microscopy, Sara T. Novell
Design Of Structural Stand For High-Precision Optics Microscopy, Sara T. Novell
Master's Theses
Lawrence Livermore National Lab (LLNL) is home to the National Ignition Facility (NIF), the world’s largest and most energetic laser. Each of the 192 beamlines contains dozens of large optics, which require offline damage inspection using large, raster-scanning microscopes. The primary microscope used to measure and characterize the optical damage sites has a precision level of 1 µm. Mounted in a class 100 clean room with a raised tile floor, the microscope is supported by a steel stand that structurally connects the microscope to the concrete ground. Due to ambient vibrations experienced in the system, the microscope is only able …
Rotordynamic Analysis Of Theoretical Models And Experimental Systems, Cameron R. Naugle
Rotordynamic Analysis Of Theoretical Models And Experimental Systems, Cameron R. Naugle
Master's Theses
This thesis is intended to provide fundamental information for the construction and
analysis of rotordynamic theoretical models, and their comparison the experimental
systems. Finite Element Method (FEM) is used to construct models using Timoshenko
beam elements with viscous and hysteretic internal damping. Eigenvalues
and eigenvectors of state space equations are used to perform stability analysis, produce
critical speed maps, and visualize mode shapes. Frequency domain analysis
of theoretical models is used to provide Bode diagrams and in experimental data
full spectrum cascade plots. Experimental and theoretical model analyses are used
to optimize the control algorithm for an Active Magnetic Bearing …