212 research outputs found
Full Court Press: Northwestern University, A New Challenge To The NCAA
In recent years, a host of issues have arisen between the National Collegiate Athletic Association (NCAA) and the college athletes who provide the labor from which the NCAA and its member universities derive their profits. Many of these issues have been heavily publicized and have spurred a heated debate over the status of college athletes and the future of the collegiate athletic system. This Article primarily focuses on the issue of college athletes’ status as employees for purposes of federal labor law. The significant increase in the popularity of college sports in recent years has led to conference realignment, facility building and arms race, governance issues and litigation. The student-athletes, the players in the highly lucrative college football and basketball games have been left behind. They have resorted to challenging the NCAA’s system in many different ways. Recently, football players at Northwestern University successfully petitioned their local Regional Director of the National Labor Relations Board for a union representation election, arguing that they are employees of the University and as such are entitled to collective bargaining rights and other protections under the National Labor Relations Act. Northwestern University has rejected this argument and has appealed the Regional Director’s decision to the National Labor Relations Board in Washington, D.C. This Article provides a background for the highly contested dispute, refutes some of the common arguments made against the potential unionization of college athletics, and discusses some of the potential implications if players can and do form a union
Two-photon excitation and absorption spectroscopy of gaseous and supercritical xenon
Spectroscopy of gases under high-pressure conditions is of interest in
various fields such as plasma physics or astrophysics. Recently, it has also
been proposed to utilize a high-pressure noble gas environment as a
thermalization medium to extend the wavelength range of photon Bose-Einstein
condensates to the vacuum-ultraviolet, from the presently accessible visible
and near-infrared spectral regimes. In this work, we report on experimental
results of two-photon spectroscopy of gaseous and supercritical xenon for
pressures as high as , probing the transitions from the
electronic ground state to the and excited
state configurations. Aiming at the exploration of possible pumping schemes for
future vacuum-ultraviolet photon condensates, we have recorded degenerate
two-photon excitation spectra of such dense xenon samples. In further
measurements, we have investigated whether irradiation of an auxiliary light
field can enhance the reabsorption of the emission on the second excimer
continuum of xenon, which is subject to a large Stokes shift. To this end,
absorption measurements have been conducted, driving the two-photon transitions non-degenerately.Comment: 6 pages, 6 figure
Properties of cage rearrangements observed near the colloidal glass transition
We use confocal microscopy to study the motions of particles in concentrated
colloidal systems. Near the glass transition, diffusive motion is inhibited, as
particles spend time trapped in transient ``cages'' formed by neighboring
particles. We measure the cage sizes and lifetimes, which respectively shrink
and grow as the glass transition approaches. Cage rearrangements are more
prevalent in regions with lower local concentrations and higher disorder.
Neighboring rearranging particles typically move in parallel directions,
although a nontrivial fraction move in anti-parallel directions, usually from
pairs of particles with initial separations corresponding to the local maxima
and minima of the pair correlation function , respectively.Comment: 5 pages, 4 figures; text & figures revised in v
Tesseract CubeSat Bus with Deployable Solar Panels
This project will aim to create a new CubeSat satellite structure that incorporates new subsystems to increase the manufacturability and versatility of PolySat’s standard satellite architecture. This new structure will incorporate deployable solar panels into the system, increasing power generation for the satellite. The structure of the CubeSat is vital to the overall system’s performance, and developing a standard high-performance system will allow for the integration of various payloads while minimizing the need for mission-specific customizations. This project will also allow for a majority of the structure to be manufactured in-house in the Cal Poly machine shops, allowing for the direct application of learn-by-doing. The integration of deployable solar panels will also involve design and fabrication of circuit boards. To complete these goals, we will leverage experience that we have had with the design and construction of previous CubeSats. Moreover, students have a chance to incorporate design processes that they have learned in various Cal Poly courses. This new structure will allow us to push the limits on what we can do with our already powerful CubeSat design. The design will allow us to provide higher performance to possible project sponsors, thus increasing the chance of winning future project proposals. Winning project proposals not only brings in funding for PolySat research projects, but also facilitates campus-wide development by bringing in additional funds for the university
Subdiffusion and the cage effect studied near the colloidal glass transition
The dynamics of a glass-forming material slow greatly near the glass
transition, and molecular motion becomes inhibited. We use confocal microscopy
to investigate the motion of colloidal particles near the colloidal glass
transition. As the concentration in a dense colloidal suspension is increased,
particles become confined in transient cages formed by their neighbors. This
prevents them from diffusing freely throughout the sample. We quantify the
properties of these cages by measuring temporal anticorrelations of the
particles' displacements. The local cage properties are related to the
subdiffusive rise of the mean square displacement: over a broad range of time
scales, the mean square displacement grows slower than linearly in time.Comment: submitted to Chemical Physics, special issue on "Strange Kinetics
Role of surface reconstruction on Cu/TiO2 nanotubes for CO2 conversion
Carbon dioxide hydrogenation to CO via the reverse water gas shift (RWGS) reaction is one route to integrate CO2 utilization into the chemical industry. TiO2 supported Cu catalysts are known to be active for RWGS, but Cu is shown here to behave differently on TiO2 nanotubes (TiNT) vs TiO2 nanoparticles (TiNP). Whereas nanoparticle supports give low rates that are hardly changed by added Cu, the nanotube supports yield much higher activity and three distinct behaviors as the Cu surface density increases. At low surface densities (0.3 Cu/nm2), active Cu-O-Ti sites are created that have low apparent activation energies. At high surface densities (6 Cu/nm2), Cu nanoparticles on TiNT are formed, and reaction barriers are lowered when both Cu and TiNT surfaces are accessible. At intermediate surface densities, metallic Cu domains are engulfed by a TiOx overlayer formed during H2 pretreatment, akin to those formed by classical strong metal support interactions (SMSI). These reduced layers are markedly more active for RWGS than the initial TiNT surfaces, but have similar activation barriers, which are higher than those for which both Cu and TiNP surfaces are exposed. These catalytic findings are supported by computational modeling, in situ IR, UV–vis, and X-ray absorption spectroscopies, and they provide insight into an important reaction for CO2 utilization
Microbe-seq : high-throughput, single-microbe genomics with strain resolution, applied to a human gut microbiome
We present Microbe-seq , a high-throughput single-microbe method that yields strain-resolved genomes from complex microbial communities. We encapsulate individual microbes into droplets with microfluidics and liberate their DNA, which we amplify, tag with droplet-specific barcodes, and sequence. We use Microbe-seq to explore the human gut microbiome; we collect stool samples from a single individual, sequence over 20,000 microbes, and reconstruct nearly-complete genomes of almost 100 bacterial species, including several with multiple subspecies strains. We use these genomes to probe genomic signatures of microbial interactions: we reconstruct the horizontal gene transfer (HGT) network within the individual and observe far greater exchange within the same bacterial phylum than between different phyla. We probe bacteria-virus interactions; unexpectedly, we identify a significant in vivo association between crAssphage, an abundant bacteriophage, and a single strain of Bacteroides vulgatus. Microbe-seq contributes high-throughput culture-free capabilities to investigate genomic blueprints of complex microbial communities with single-microbe resolution
Aeolian features on Venus: Preliminary Magellan results
Magellan synthetic aperture radar data reveal numerous surface features that are attributed to aeolian, or wind processes. Wind streaks are the most common aeolian feature. They consist of radar backscatter patterns that are high, low, or mixed in relation to the surface on which they occur. A data base of more than 3400 wind streaks shows that low backscatter linear forms (long, narrow streaks) are the most common and that most streaks occur between 17°S to 30°S and 5°N to 53°N on smooth plains. Moreover, most streaks are associated with deposits from certain impact craters and some tectonically deformed terrains. We infer that both of these geological settings provide fine particulate material that can be entrained by the low-velocity winds on Venus. Turbulence and wind patterns generated by the topographic features with which many streaks are associated can account for differences in particle distributions and in the patterns of the wind streaks. Thus, some high backscatter streaks are considered to be zones that are swept free of sedimentary particles to expose rough bedrock; other high backscatter streaks may be lag deposits of dense materials from which low-density grains have been removed (dense materials such as ilmenite or pyrite have dielectric properties that would produce high backscatter patterns). Wind streaks generally occur on slopes < 2° and tend to be oriented toward the equator, consistent with the Hadley model of atmospheric circulation. In addition to wind streaks, other aeolian features on Venus include yardangs(?) and dune fields. The Aglaonice dune field, centered at 25°S, 340°E, covers ∼1290 km^2 and is located in an ejecta flow channel from the Aglaonice impact crater. The Meshkenet dune field, located at 67°N, 90°E, covers ∼17,120 km^2 in a valley between Ishtar Terra and Meshkenet Tessera. Wind streaks associated with both dune fields suggest that the dunes are of transverse forms in which the dune crests are perpendicular to the prevailing winds. Dunes on Venus signal the presence of sand-size (∼60 to 2,000 μm) grains. The possible yardangs are found at 9°N, 60.5°E, about 300 km southeast of the crater Mead. Although most aeolian features are concentrated in smooth plains near the equator, the occurrence of wind streaks is widespread, and some have been found at all latitudes and elevations. They demonstrate that aeolian processes operate widely on Venus. The intensity of wind erosion and deposits, however, varies with locality and is dependent on the wind regime and supply of particles
- …