2,679 research outputs found
A Day in the Life of a Float Plane Charter Pilot
Ever taken a float plane trip or wanted to? Learn what it’s like to be a float plane pilot doing charter work in the Puget Sound area of Washington state. Hear this light-heated, informal, presentation by someone who has done all this for “fun and profit”
Simple Waves in Ideal Radiation Hydrodynamics
In the dynamic diffusion limit of radiation hydrodynamics, advection
dominates diffusion; the latter primarily affects small scales and has
negligible impact on the large scale flow. The radiation can thus be accurately
regarded as an ideal fluid, i.e., radiative diffusion can be neglected along
with other forms of dissipation. This viewpoint is applied here to an analysis
of simple waves in an ideal radiating fluid. It is shown that much of the
hydrodynamic analysis carries over by simply replacing the material sound
speed, pressure and index with the values appropriate for a radiating fluid. A
complete analysis is performed for a centered rarefaction wave, and expressions
are provided for the Riemann invariants and characteristic curves of the
one-dimensional system of equations. The analytical solution is checked for
consistency against a finite difference numerical integration, and the validity
of neglecting the diffusion operator is demonstrated. An interesting physical
result is that for a material component with a large number of internal degrees
of freedom and an internal energy greater than that of the radiation, the sound
speed increases as the fluid is rarefied. These solutions are an excellent test
for radiation hydrodynamic codes operating in the dynamic diffusion regime. The
general approach may be useful in the development of Godunov numerical schemes
for radiation hydrodynamics.Comment: 16 pages, 10 figures, accepted for publication in The Astrophysical
Journa
Examining the Value of a Bachelor\u27s Degree for Helicopter Pilots
Traditionally, a bachelor’s degree has never been a qualification requirement for entry-level helicopter pilots obtaining employment or for even becoming entirely successful helicopter pilots in the industry.As helicopter companies grow into larger corporate entities, a bachelor’s degree is beginning to appear as a desirable qualification on some helicopter pilot job advertisements.Currently, only corporate helicopter operators, aircraft manufacturers, and some branches of the military actually require their helicopter pilots to hold 4-year degrees
Off-Shore Helicopter Operations
This case study research project is based on a foreign oil company desiring to set up and provide helicopter transportation to and from oil rigs in the gulf. Theresearch resulted in three potential options: Purchase a carrier with a current operating certificate Start a new company Contract an existing operator to perform the operations
The Quantum McKay Correspondence for polyhedral singularities
Let G be a polyhedral group, namely a finite subgroup of SO(3). Nakamura's
G-Hilbert scheme provides a preferred Calabi-Yau resolution Y of the polyhedral
singularity C^3/G. The classical McKay correspondence describes the classical
geometry of Y in terms of the representation theory of G. In this paper we
describe the quantum geometry of Y in terms of R, an ADE root system associated
to G. Namely, we give an explicit formula for the Gromov-Witten partition
function of Y as a product over the positive roots of R. In terms of counts of
BPS states (Gopakumar-Vafa invariants), our result can be stated as a
correspondence: each positive root of R corresponds to one half of a genus zero
BPS state. As an application, we use the crepant resolution conjecture to
provide a full prediction for the orbifold Gromov-Witten invariants of [C^3/G].Comment: Introduction rewritten. Issue regarding non-uniqueness of conifold
resolution clarified. Version to appear in Inventione
A numerical ocean circulation model of the Norwegian and Greenland Seas
The dynamics and thermodynamics of the Norwegian and Greenland Seas are investigated using a three-dimensional primitive equation ocean circulation model. The horizontal resolution of the model is 1° in the zonal direction and 0.5° in the meridional direction. The vertical structure is described by 15 levels. The model is driven by both annual mean and seasonally varying wind and thermohaline forcing. The connections of the Norwegian and Greenland Seas with the North Atlantic and Arctic Ocean are modelled with an open boundary condition. The simulated currents are in reasonable agreement with the observed circulation
Assessment of the knowledge and perceptions of agriculture by selected fourth grade teachers in Oklahoma
Connecting general education programming with regionally-engaged learning economies: The results of a community inquiry and dialogue
There is a growing effort to more intentionally situate higher education as an anchor institution within a larger regional, social, political, and economic ecosystem. This paper describes the civic process and outcomes of a community inquiry that considered the relationship between general education programming at comprehensive universities and the trajectory of regional economies. The community inquiry leveraged intergroup dialogue techniques to provide a unique community perspective on potential ways general education can inform engaged learning economies. The result of this community inquiry and dialogue highlight three broad themes that could connect general education programs to engaged learning economies in other regions: campus-community partnerships, logistics of a general education program, and reconsidering the relationship between academic knowledge and soft skills. The results section describes, summarizes, and analyzes the proceedings from the perspective of community
The Ruled Vertex and Nontoric del Pezzo Surfaces
We construct the topological partition function of local nontoric del Pezzo
surfaces using the ruled vertex formalism.Comment: 16 pages, 4 figure
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