Freeway Removal in Milwaukee: Three Case Studies

A growing number of cities are choosing to remove parts of their urban freeway network to make room for alternative land uses. This study examines the history of two freeway spurs in Milwaukee—the Park East Freeway and Interstate 794—which were both targeted for demolition. Park East was demolished in 2002, but Interstate 794, which was considered for partial demolition on two separate occasions, was eventually rebuilt. This study asks what the cases of Park East and I-794 can tell us about the attributes of a successful freeway teardown project. This study traces the history of both freeways from the 1950s to the present, drawing on a mix of newspaper coverage, archival sources, planning documents, and relevant scholarly studies. This thesis makes two arguments. First, it argues that the cases of Park East and I-794 support the idea that freeway removal efforts may need: (1) An adequate window of opportunity; (2) a strong advocate for the teardown option; (3) strong business support, and; (4) reasonable assurances from teardown proponents that the removal option will “do no harm.” Second, it argues that the I-794 outcome can be partly explained by a major state investment in the freeway in the 1990s

Phonon engineering through crystal chemistry

Mitigation of the global energy crisis requires tailoring the thermal conductivity of materials. Low thermal conductivity is critical in a broad range of energy conversion technologies, including thermoelectrics and thermal barrier coatings. Here, we review the chemical trends and explore the origins of low thermal conductivity in crystalline materials. A unifying feature in the latest materials is the incorporation of structural complexity to decrease the phonon velocity and increase scattering. With this understanding, strategies for combining these mechanisms can be formulated for designing new materials with exceptionally low thermal conductivity

Melting of cognetic depleted and enriched reservoirs and the production of high Ti Mare basalts

Implicit in current understanding of the location of terrestrial enriched and depleted reservoirs is the notion that they are spatially separated. The depleted reservoir on Earth is situated in the upper mantle, and the complementary enriched reservoir is located in the crust. However, Earth reservoirs are continually being modified by recycling driven by mantle convection. The Moon is demonstrably different from Earth in that its evolution was arrested relatively early - effectively with 1.5 Ga of its formation. It is possible that crystallized trapped liquids (from the late stages of a magma ocean) have been preserved as LILE-enriched portions of the lunar mantle. This would lead to depleted (cumulate) and enriched (magma ocean residual liquid) reservoirs in the lunar upper mantle. There is no evidence for significant recycling from the highland crust back into the mantle. Therefore, reservoirs created at the Moon's inception may have remained intact for over 4.0 Ga. The topics discussed include the following: (1) radiogenic isotopes in high-Ti mare basalts; (2) formation of cogenetic depleted and enriched reservoirs; and (3) melting of the source to achieve high-Ti mare basalts

High rates of polygyny in tropical Mexico within the native range of Vespula squamosa.

Polygyny, or the formation of colonies with multiple cooperating queens, has been observed in a variety of social Hymenoptera and likely exists as a convergent evolutionary strategy. Polygyne cooperation has been observed in several Vespula sp. and is correlated with a perennial social strategy. This perennial-polygyne behavior has been observed most commonly within the tropical and subtropical regions of the invasive Vespula pensylvanica and V. germanica, and rarely within their native temperate ranges. This phenomenon has been relatively undocumented within the tropical portions the V. squamosa native range, despite it being observed in their temperate ranges several times. We observed polygyny in seven out of eight colonies of V. squamosa at a Santiago Apoala site in Oaxaca, Mexico. Our findings suggest that polygyny in these Vespula species is not solely the product of a genetic or population bottleneck resulting from introduction, but rather some undetermined environmental effects

Thermoelectric properties of Zn-doped Ca_5In_2Sb_6

The Zintl compound Ca_5Al_2Sb_6 is a promising thermoelectric material with exceptionally low lattice thermal conductivity resulting from its complex crystal structure. In common with the Al analogue, Ca_5In_2Sb_6 is naturally an intrinsic semiconductor with a low p-type carrier concentration. Here, we improve the thermoelectric properties of Ca_5In_2Sb_6 by substituting Zn^(2+) on the In^(3+) site. With increasing Zn substitution, the Ca_5In_(2−x)Zn_xSb_6 system exhibits increased p-type carrier concentration and a resulting transition from non-degenerate to degenerate semiconducting behavior. A single parabolic band model was used to estimate an effective mass in Ca_5In_2Sb_6 of m^* = 2m_e, which is comparable to the Al analogue, in good agreement with density functional calculations. Doping with Zn enables rational optimization of the electronic transport properties and increased zT in accordance with a single parabolic band model. The maximum figure of merit obtained in optimally Zn-doped Ca_5In_2Sb_6 is 0.7 at 1000 K. While undoped Ca_5In_2Sb_6 has both improved electronic mobility and reduced lattice thermal conductivity relative to Ca_5Al_2Sb_6, these benefits did not dramatically improve the Zn-doped samples, leading to only a modest increase in zT relative to optimally doped Ca_5Al_2Sb_6

PC-CUBE: A Personal Computer Based Hypercube

PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation

Geochemical and isotopic evidence bearing on the origin of large, igneous-textured inclusions in ordinary chondrites

Geochemical and isotopic data for large, igneous-textured inclusions in ordinary chondrites suggest that the inclusions formed by the melting of diverse precursors, and that various inclusions had different origins. Some inclusions were metasomatized (chemically altered) and metamorphosed, and many appear to have degassed argon in late shock events. The inclusions can be subdivided into two chemical groups, Na-rich (Na/Al>0.35 at.) and Na-poor (≤0.35), which may have originated in different ways. The major-and trace-element abundances of Na-rich inclusions are best explained by these inclusions having formed by the shock-melting of ordinary chondrites, often accompanied by loss of FeNi-metal and sulfide and by preferential melting and accumulation of an albitic feldspar component. In contrast, there is no evidence that shock-melting was involved in the formation of Na-poor inclusions, which have compositions that were largely controlled by vapor-fractionation processes. It is suggested that the precursors to Na-poor inclusions consisted of mixtures of vapor-fractionated materials in a system of condensed phases that chemically resembled CI-chondrites, except for being depleted in volatile-lithophile elements and in metal and sulfide. Sodium-poor inclusions can be subdivided into two types, Trend A and Trend B, which differ in their trace-element characteristics, in the nature of their compositional variations, and in their inferred precursors. Trend A Na-poor inclusions are enriched in refractory elements, and could have formed by the melting of mixtures containing a chondritic (CI-like) component and a refractory (Al-rich, CAI-like) component. Trend B Na-poor inclusions are enriched in elements of intermediate volatility (Si) and appear to have formed from precursors that lost both a refractory (Mg-rich, olivine-rich) and a volatile component. The precursors to these inclusions could have been produced by the removal of an olivine-rich condensate during fractional condensation, or by the condensation of Si-rich gases during fractional vaporization

Raytheon -- Strength Optimized Designs Using Additive Manufacturing

Designing a structure to demonstrate the strength of 3-D printed part is more complicated than it seems. The design goal was to construct a device that demonstrates how 3-D printing can create a strength optimized design. The design must incorporate maximum strength, while not sacrificing other major components such as weight of the product, cost of the product, print time of the product and how much material is being used. Extensive research and tests were conducted on infill patterns, football helmets, and TPU material (material used in football helmets). There are multiple infill patterns that must be considered. The most important aspect of printing parts via FDM 3D printing is the infill pattern. This will directly affect the print time, material used, cost, and strength of the printed part. The second most important concept of the 3-D printed part is the infill structure. There are many infill structures, each having its own strengths and weaknesses when approaching higher strength, time to print, material used and weight. The team decided to focus on four commonly used infill structures (honeycomb, wiggle, triangular, and rectilinear). The team conducted a 3-point bending test and compression test, strictly following the ATSM standards to find out more about the strengths and weaknesses of each specific infill pattern (shown in this report). A design has been created and the application is a football Helmet. The design has 2 parts. The first part is a smaller, circular piece as the very top of the helmet. This piece contains a “triple layer infill sandwich.” The triple layer infill sandwich is composed of 3 different infills: wiggle infill (good for distributing rotational energy), honeycomb infill (good for distributing linear impact), wiggle infill again (good for distributing rotational energy). The second part of the helmet liner is a dome composed of an Isomax structure with a hole cut out at the top of the helmet. The team originally came up with 120 different designs in an attempted to best solve the task at hand. The method from obtaining these ideas came from brainstorming and online research. To narrow the solutions, a table was made with different attributes and rankings with each attribute. The team went through each individual concept and ranked it accordingly. After we had our top ideas team 13 conducted specific testing to figure out which idea was best and team 13 came up with this specific helmet liner