Recognizing the 150th Anniversary of the Dakota-U.S. War of 1862 and Declaring 2012-2013 the Year of the Dakota in Redwood Falls

Resolution adopted by the city of Redwood Falls in response to the city\u27s history with the Dakota People. This resolution was used as a precedent in the University of Denver\u27s study of its relationship with John Evans and the Sand Creek Massacre

Lessons Learned from PEP-II LLRF and Longitudinal Feedback

The PEP-II B-Factory collider ended the final phase of operation at nearly twice the design current and 4X the design luminosity. To highlight the evolution from the original conceptual design through to the 1.2E34 final machine we choose one example each from the broadband feedback and from the LLRF system. They illustrate the original design estimation missed some very significant details, and how in the course of PEP-II operation unexpected difficulties led to significant insights and new approaches which allowed higher machine performance. We present valuable 'lessons learned' which are of interest to designers of next generation feedback and impedance controlled LLRF systems

Validation and interpretability of data-driven models

This is a Whitepaper submitted to the 2017 DOE ASCR Applied Math Meeting. It addresses research topics in the "Convergence of data- and model-driven discovery" subject area. In particular, it proposes research activities that would enhance the interpretability of data-driven models, such as neural nets, which are increasing being used in multiscale simulations for upscaling/downscaling operations e.g., as turbulence closures etc. The research would allow us validate such empirical, data-driven models against physics theory

Distribution of ion-implanted yttrium in Cr sub 2 O sub 3 scale and in the underlying Ni-25 wt % Cr alloy

Implantation of yttrium and other reactive metals has been known to show significant effects on the oxidation behavior of Cr{sub 2}O{sub 3}-forming alloys. The oxide growth rate decreases by nearly a factor of ten, and the adhesion of oxide scales to alloys is greatly improved. To better understand the mechanisms by which these elements affect oxidation, it is important to know whether or not they are present in the metal ahead of the oxide layer. In this study, the diffusivity of implanted yttrium in a Ni-25 wt %Cr alloy and its distribution in the oxide scale after different oxidation times have been evaluated using secondary ion mass spectroscopy. It was found that only 17 ppm of yttrium was left in the alloy after just 20 minutes of oxidation at 1000{degrees}C. The implanted Y remained concentrated at the oxide/gas interface as the oxide thickened with time. Within the oxide layer, the Y concentration progressively dropped to zero at the scale/alloy interface. These results are discussed in relation to several important mechanisms proposed for the beneficial effects of reactive element additions on scale adhesion. 17 refs., 5 figs

Trace element and isotope geochemistry of geothermal fluids, East Rift Zone, Kilauea, Hawaii

A research program has been undertaken in an effort to better characterize the composition and the precipitation characteristic of the geothermal fluids produced by the HGP-A geothermal well located on the Kilauea East Rift Zone on the Island of Hawaii. The results of these studies have shown that the chemical composition of the fluids changed over the production life of the well and that the fluids produced were the result of mixing of at least two, and possibly three, source fluids. These source fluids were recognized as: a sea water composition modified by high temperature water-rock reactions; meteoric recharge; and a hydrothermal fluid that had been equilibrated with high temperature reservoir rocks and magmatic volatiles. Although the major alkali and halide elements show clearly increasing trends with time, only a few of the trace transition metals show a similar trend. The rare earth elements, were typically found at low concentrations and appeared to be highly variable with time. Studies of the precipitation characteristics of silica showed that amorphous silica deposition rates were highly sensitive to fluid pH and that increases in fluid pH above about 8.5 could flocculate more than 80% of the suspended colloidal silica in excess of its solubility. Addition of transition metal salts were also found to enhance the recovery fractions of silica from solution. The amorphous silica precipitate was also found to strongly scavenge the alkaline earth and transition metal ions naturally present in the brines; mild acid treatments were shown to be capable of removing substantial fractions of the scavenged metals from the silica flocs yielding a moderately pure gelatinous by-product. Further work on the silica precipitation process is recommended to improve our ability to control silica scaling from high temperature geothermal fluids or to recover a marketable silica by-product from these fluids prior to reinjection