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Control Parameters and Materials Selection Criteria for Rapid Prototyping Systems
Since the introduction ofrapid prototyping technology as a tool for time
compression and concurrent engineering in the design and manufacturing process, many
enhancements and refinements have been made based on the experience ofusers and
manufacturers ofrapid prototyping equipment. These improvements contribute
significantly to faster production of quality output from rapid prototyping systems.
There are diverse control and material selection parameters that affect prototype
models built using the Fused Deposition Modeling (FDM®) process. This paper reviews
the role of several ofthese parameters in the process. Data will be presented to help the
user choose the appropriate material for specific applications including density, tensile
stiffhess, flexural stiffhess, tensile strength, flexural strength, tensile ductility, shock
resistance, and hardness.Mechanical Engineerin
Eastern Ishtar Terra: Tectonic evolution derived from recognized features
Previous analyses have recognized several styles and orientations of compressional deformation, crustal convergence, and crustal thickening in Eastern Ishtar Terra. An east to west sense of crustal convergence through small scale folding, thrusting, and buckling is reflected in the high topography and ridge-and-valley morphology of Maxwell Montes and the adjacent portion of Fortuna Tessera. This east to west convergence was accompanied by up to 1000 km of lateral motion and large scale strike-slip faulting within two converging shear zones which has resulted in the present morphology of Maxwell Montes. A more northeast to southwest sense of convergence through large scale buckling and imbrication is reflected in large, northwest-trending scarps along the entire northern boundary of Ishtar Terra, with up to 2 km of relief present at many of the scarps. It was previously suggested that both styles of compression have occurred at the expense of pre-existing tessera regions which have then been overprinted by the latest convergence event. The difference in style is attributed mostly to differences in the properties of the crust converging with the tessera blocks. If one, presumably thick, tessera block converges with another tessera region, then the widespread, distributed style of deformation occurs, as observed in western Fortuna Tessera. However, if relatively thin crust (such as suggested for the North Polar Plains converges with thicker tessera regions, then localized deformation occurs, as reflected in the scarps along Northern Ishtar Terra. The purpose is to identify the types of features observed in Eastern Ishtar Terra. Their potential temporal and spatial relationships, is described, possible origins for them is suggested, and how the interpretation of some of these features has led to the multiple-style tectonic evolution model described is shown
Bars and spirals in tidal interactions with an ensemble of galaxy mass models
We present simulations of the gaseous and stellar material in several
different galaxy mass models under the influence of different tidal fly-bys to
assess the changes in their bar and spiral morphology. Five different mass
models are chosen to represent the variety of rotation curves seen in nature.
We find a multitude of different spiral and bar structures can be created, with
their properties dependent on the strength of the interaction. We calculate
pattern speeds, spiral wind-up rates, bar lengths, and angular momentum
exchange to quantify the changes in disc morphology in each scenario. The
wind-up rates of the tidal spirals follow the 2:1 resonance very closely for
the flat and dark matter dominated rotation curves, whereas the more baryon
dominated curves tend to wind-up faster, influenced by their inner bars. Clear
spurs are seen in most of the tidal spirals, most noticeable in the flat
rotation curve models. Bars formed both in isolation and interactions agree
well with those seen in real galaxies, with a mixture of "fast" and "slow"
rotators. We find no strong correlation between bar length or pattern speed and
the interaction strength. Bar formation is, however, accelerated/induced in
four out of five of our models. We close by briefly comparing the morphology of
our models to real galaxies, easily finding analogues for nearly all
simulations presenter here, showing passages of small companions can easily
reproduce an ensemble of observed morphologies.Comment: 30 pages, 29 colour figures, accepted for publication in MNRAS.
Videos of simulations can be found at
http://www.youtube.com/playlist?list=PLQKy--XcWrIVBc1sS2RNc-ekyfeBsGtD
The Directional Dependence of Apertures, Limits and Sensitivity of the Lunar Cherenkov Technique to a UHE Neutrino Flux
We use computer simulations to obtain the directional-dependence of the lunar
Cherenkov technique for ultra-high energy (UHE) neutrino detection. We
calculate the instantaneous effective area of past lunar Cherenkov experiments
as a function of neutrino arrival direction, and hence the
directional-dependence of the combined limit imposed by GLUE and the experiment
at Parkes.
We also determine the directional dependence of the aperture of future
planned experiments with ATCA, ASKAP and the SKA to a UHE neutrino flux, and
calculate the potential annual exposure to astronomical objects as a function
of angular distance from the lunar trajectory through celestial coordinates.Comment: 17 pages, 7 figures; Submitted to Astroparticle Physic
Shuttle orbiter radar cross-sectional analysis
Theoretical and model simulation studies on signal to noise levels and shuttle radar cross section are described. Pre-mission system calibrations, system configuration, and postmission system calibration of the tracking radars are described. Conversion of target range, azimuth, and elevation into radar centered east north vertical position coordinates are evaluated. The location of the impinging rf energy with respect to the target vehicles body axis triad is calculated. Cross section correlation between the two radars is presented
Heegaard diagrams and surgery descriptions for twisted face-pairing 3-manifolds
The twisted face-pairing construction of our earlier papers gives an
efficient way of generating, mechanically and with little effort, myriads of
relatively simple face-pairing descriptions of interesting closed 3-manifolds.
The corresponding description in terms of surgery, or Dehn-filling, reveals the
twist construction as a carefully organized surgery on a link.
In this paper, we work out the relationship between the twisted face-pairing
description of closed 3-manifolds and the more common descriptions by surgery
and Heegaard diagrams. We show that all Heegaard diagrams have a natural
decomposition into subdiagrams called Heegaard cylinders, each of which has a
natural shape given by the ratio of two positive integers. We characterize the
Heegaard diagrams arising naturally from a twisted face-pairing description as
those whose Heegaard cylinders all have integral shape. This characterization
allows us to use the Kirby calculus and standard tools of Heegaard theory to
attack the problem of finding which closed, orientable 3-manifolds have a
twisted face-pairing description.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-10.abs.htm
A MARKET OPPORTUNITY STUDY FOR THE DEVELOPMENT OF A NEW SPORT HORSE SERVICE AT THE MSU VETERINARY TEACHING HOSPITAL
The potential need for several new services within the Veterinary Teaching Hospital (VTH) is unknown. However, based on focus groups and practitioner surveys conducted over the last several years, potential new services were identified: overnight emergency, behavior medicine, equine sports medicine, dentistry, oncology and exotic animal medicine. Michigan State University's College of Veterinary Medicine (MSU-CVM) has recently expanded its equine research, diagnostic and therapy capabilities with the addition of the new Mary Anne McPhail Equine Performance Center. As a result of this expansion, a study was conducted to determine whether the VTH should also broaden its clinical offerings with a new complement of services targeted specifically toward sport horse care.Teaching/Communication/Extension/Profession,
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