Missouri Watershed Water Quality Initiative

Agricultural and Food Policy, Environmental Economics and Policy,

A Reimagining of the Chacoan World

A new paradigm of the Chacoan world is presented, wherein Chaco Canyon is considered to be a mostly unoccupied architectural complex that functioned primarily as a pilgrimage destination. Chaco was the political, religious, and social focal point of people living in outlying regions. The resident population of the Canyon consisted of a small number of caretakers, charged with maintaining great house structures, food supplies, and their ceremonial contents. Chacoan chiefdoms were mostly located in large, well-watered, agriculturally-based communities situated at the base of mountains that ring the San Juan Basin, e.g., the Chuskas. Chiefly elites lived year-round in those areas, but during pilgrimages they occupied Canyon great houses associated with their respective dynasties, whereas their subjects occupied small houses situated on the Canyon floor. Not having 2000 people in the Canyon renders large-scale irrigated agriculture and massive importation of food unnecessary and provides an adequate explanation for the small number of burials found in the Canyon. Se presenta un nuevo paradigma del mundo chacoano, en el que el Cañón del Chaco es considerado como un complejo arquitectónico mayoritariamente desocupado que funcionaba principalmente como destino de peregrinación. Chaco fue el centro político, religioso y social de las personas que viven en regiones al aire libre. La población residente del Cañón consistía en un pequeño número de cuidadores, encargados de mantener grandes estructuras de casas, suministros de alimentos y su contenido ceremonial. Las jefaturas chacoanas se encontraban principalmente en grandes comunidades agrícolas bien regadas situadas en la base de montañas que anillan la cuenca de San Juan, por ejemplo, los Chuskas. Principalmente las élites vivían durante todo el año en esas áreas, pero durante las peregrinaciones ocuparon grandes casas del Cañón asociadas con sus respectivas dinastías, mientras que sus súbditos ocupaban pequeñas casas situadas en el suelo del Cañón. No tener 2000 personas en el Cañón hace que la agricultura de regadío a gran escala y la importación masiva de alimentos sean innecesarias y proporciona una explicación adecuada para el pequeño número de entierros encontrados en el Cañón

Calculation of a circular jet in crossflow with a multiple-time-scale turbulence model

Numerical calculation of a three dimensional turbulent flow of a jet in a crossflow using a multiple time scale turbulence model is presented. The turbulence in the forward region of the jet is in a stronger inequilibrium state than that in the wake region of the jet, while the turbulence level in the wake region is higher than that in the front region. The calculated flow and the concentration fields are in very good agreement with the measured data, and it indicated that the turbulent transport of mass, concentration, and momentum is strongly governed by the inequilibrium turbulence. The capability of the multiple time scale turbulence model to resolve the inequilibrium turbulence field is also discussed

Applications of ERTS-1 imagery to agricultural resource evaluation

There are no author-identified significant results in this report

The effect of an isotopic non-equilibrium plasma on electron temperature measurements

Electron temperatures determined by electrostatic probe, diffuse resonance, and radar backscatter techniques in an isotropic two temperature plasma are presented. Plasma models corresponding to the addition of a minor component of energetic electrons, and models corresponding to a process that cools a fraction of the ionospheric electrons are considered. The diffuse resonance temperature is found to lie between the probe and radar backscatter temperatures. The isotropic models corresponding to the addition of energetic electrons cannot support the reported discrepancies between radio wave and probe electron temperature measurements. Temperature differences similar to the observed differences can be produced by models with a fraction of the electrons at a temperature cooler than that of the main component of electrons

Arsenic Consumption and Health Risk Perceptions in a Rural Western U.S. Area

Churchill County, Nevada had approximately 23,000 residents, with an estimated 13,500 who relied on private wells for water supply in 2002. This study examined exposure to arsenic in water supplies among residents with private domestic wells and factors related to householder choice to consume tap water. It compared opinions and concerns about water quality with consumption habits and observed concentrations from tap water samples. The results from 351 households indicated that a majority (75%) of respondents consumed tap water and that a minority (38%) applied treatment. Approximately 66% of those who consumed tap water were exposed to concentrations of arsenic that exceeded 10 ppb. Water consumption was related to application of treatment. Among 98 respondents who were not at all concerned about the health effects of aqueous arsenic, 59 (60%) reported consuming tap water with concentrations of arsenic exceeding 10 ppb. Conversely, among 86 respondents who were highly concerned about arsenic, 33 (37%) consumed tap water with concentrations of arsenic exceeding 10 ppb. Results from a national sampling effort showed that 620/5304 (11.7%) of private wells sampled had arsenic concentrations above 10 ppb. The paradox of awareness of arsenic in water supplies coupled with consumption of aqueous arsenic in concentrations of >10 ppb may be common in other parts of the nation. Enhanced educational efforts, especially related to tap water sampling and explanations of efficacy of available treatment, may be a useful means of reducing exposure through private water supplies.Health Economics and Policy, Resource /Energy Economics and Policy,

'Flying Plasmons': Fabry-P\`erot Resonances in Levitated Silver Nanowires

Plasmonic nano structures such as wire waveguides or antennas are key building blocks for novel highly integrated photonics. A quantitative understanding of the optical material properties of individual structures on the nanoscale is thus indispensable for predicting and designing the functionality of complex composite elements. In this letter we study propagating surface plasmon polaritons in single silver nanowires isolated from its environment by levitation in a linear Paul trap. Symmetry-breaking effects, e.g., from supporting substrates are completely eliminated in this way. Illuminated with white light from a supercontinuum source, Fabry-P\`erot-like resonances are observed in the scattering spectra obtained from the ends of the nanowires. The plasmonic nature of the signal is verified by local excitation and photon collection corresponding to a clean transmission measurement through a Fabry-P\`erot resonator. A numerical simulation is used to compute the complex effective refractive indices of the nanowires as input parameter for a simple Fabry-P\`erot model, which nicely reproduces the measured spectra despite the highly dispersive nature of the system. Our studies pave the way for quantitative characterization of nearly any trappable plasmonic nano object, even of fragile ones such as droplets of liquids or molten metal and of nearly any nanoresonator based on a finite waveguide with implications for modeling of complex hybrid structures featuring strong coupling or lasing. Moreover, the configuration has the potential to be complemented by gas sensors to study the impact of hot electrons on catalytic reactions nearby plasmonic particles

Cool Core Bias in Sunyaev-Zel'dovich Galaxy Cluster Surveys

Sunyaev-Zeldovich (SZ) surveys find massive clusters of galaxies by measuring the inverse Compton scattering of cosmic microwave background off of intra-cluster gas. The cluster selection function from such surveys is expected to be nearly independent of redshift and cluster astrophysics. In this work, we estimate the effect on the observed SZ signal of centrally-peaked gas density profiles (cool cores) and radio emission from the brightest cluster galaxy (BCG) by creating mock observations of a sample of clusters that span the observed range of classical cooling rates and radio luminosities. For each cluster, we make simulated SZ observations by the South Pole Telescope and characterize the cluster selection function, but note that our results are broadly applicable to other SZ surveys. We find that the inclusion of a cool core can cause a change in the measured SPT significance of a cluster between 0.01% - 10% at z > 0.3, increasing with cuspiness of the cool core and angular size on the sky of the cluster (i.e., decreasing redshift, increasing mass). We provide quantitative estimates of the bias in the SZ signal as a function of a gas density cuspiness parameter, redshift, mass, and the 1.4 GHz radio luminosity of the central AGN. Based on this work, we estimate that, for the Phoenix cluster (one of the strongest cool cores known), the presence of a cool core is biasing the SZ significance high by ~ 6%. The ubiquity of radio galaxies at the centers of cool core clusters will offset the cool core bias to varying degrees.Comment: 8 pages, 4 figures, accepted to Ap