The Geometry of Axisymmetric Ideal Fluid Flows with Swirl

The sectional curvature of the volume preserving diffeomorphism group of a Riemannian manifold $M$ can give information about the stability of inviscid, incompressible fluid flows on $M$. We demonstrate that the submanifold of the volumorphism group of the solid flat torus generated by axisymmetric fluid flows with swirl, denoted by $\mathcal{D}_{\mu,E}(M)$, has positive sectional curvature in every section containing the field $X = u(r)\partial_\theta$ iff $\partial_r(ru^2)>0$. This is in sharp contrast to the situation on $\mathcal{D}_{\mu}(M)$, where only Killing fields $X$ have nonnegative sectional curvature in all sections containing it. We also show that this criterion guarantees the existence of conjugate points on $\mathcal{D}_{\mu,E}(M)$ along the geodesic defined by $X$.Comment: 8 page

Morbidity and Mortality: Human Paleopathology and Burial Treatment

Honors (Bachelor's)AnthropologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/134714/1/pwash.pd

Child Vehicular Heatstroke Deaths: How the Criminal Legal System Punishes Grieving Parents Over a Neurobiological Response

Twenty states have passed criminal statutes aimed at reducing heat stroke deaths resulting from a child being left in a vehicle. This Note examines those statutes and the legal theories of punishment they rely upon. The Note proposes that state legislatures repeal these statutes and instead increase funding for programs aimed at expanding awareness and technological advances focused on preventing these tragedies

The Effect of Geometric Scale on the Configuration of a Solar Sail

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77249/1/AIAA-2002-1200-419.pd

A Feasibility Study of Micro-Satellites for Earth Observation

There is a continuing desire to minimize the fabrication, launch, and operational costs of Earth-observing satellites, while still maintaining their high-resolution capabilities. Micro-satellites have been suggested as a method for obtaining these results using several different configurations; such as conventional filled aperture optics, distributed aperture systems, constellations and tethers. The ability of the different spacecraft types to achieve images of a specified resolution and quality are examined, as are their affects on the mass and size of the spacecraft. However, first a minimum spacecraft size is discussed and formulated for missions of this and similar types. This is used as a first order analysis to determine when micro-satellites may be applicable to a specific mission. These results, and those from the analysis of the different spacecraft types are then used to determine when, and if, it is beneficial to use a micro-satellite over a more conventional spacecraft design. It will be demonstrated that distributed aperture systems and deployable primary mirrors are generally the best approaches for highresolution- imaging micro-satellites, but that distributed aperture systems are useful when replacing very large primary mirrors

An Experiential Introduction to Aerospace Engineering

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77054/1/AIAA-2007-296-801.pd

Criticality of natural absorbing states

We study a recently introduced ladder model which undergoes a transition between an active and an infinitely degenerate absorbing phase. In some cases the critical behaviour of the model is the same as that of the branching annihilating random walk with $N\geq 2$ species both with and without hard-core interaction. We show that certain static characteristics of the so-called natural absorbing states develop power law singularities which signal the approach of the critical point. These results are also explained using random walk arguments. In addition to that we show that when dynamics of our model is considered as a minimum finding procedure, it has the best efficiency very close to the critical point.Comment: 6 page

Resource availability and territorial behavior in Ruby-throated Hummingbirds (Archilochus colubris) at UMBS

General EcologyThe goal of this study was to determine if Ruby-throated Hummingbirds (Archilochus colubris) exhibited territorial behaviors in relation to varied degrees of nectar availability. In order to examine this territorial behavior, we worked with students in the ornithology class to set-up 6 feeding sites at the edge of a field and woods at the University of Michigan Biological Station (UMBS) in Pellston, Michigan. Feeders at the sites were used to mimic low, intermediate, and high resource availability. Our group predicted that males would exhibit more territorial behavior than females at the sites with higher resource abundance. We also expected the most interactions to occur among males. We observed and recorded the territorial behavior of chasing at the feeding sites 3 times a day for hour-long periods for 4 days. Our results showed that the highest number of chasing behavior occurred at the single-feeder stations amongst females. We observed relatively low numbers of chasing between males. Furthermore, we observed that males preferred visiting sites with more feeders whereas females did not exhibit a clear preference of feeder abundance. Further studies on hummingbird territorial behavior would be beneficial to clarify whether chasing amongst females is common.http://deepblue.lib.umich.edu/bitstream/2027.42/116607/1/DesJardins_Hill_Washabaugh_Wellman_2015.pd