Analysis of the plugging of the systems autonomy demonstration project brassboard filters

A fine gray powder was clogging the brassboard filters. The powder appeared to be residue from a galvanic corrosive attack by ammonia of the aluminum and stainless steel components in the system. The corrosion was caused by water and chlorine that had entered into the system and combined with the ammonia. This combination made an electrolyte and a corrosive agent of the ammonia that attacked the metals in the system. The corroded material traveled through the system with the ammonia and clogged the filters. Key conclusions are: the debris collecting in the filters is a by-product of galvanic corrosion; the debris is principally corroded aluminum and stainless from the system; and galvanic corrosion occurred from water and chlorine that entered the system during normal and/or extreme operating and servicing conditions. Key recommendations are: use only one metal in the ammonia system-titanium, aluminum, or stainless steel; make the system as air-tight as possible (replace fittings with welded joints); and replace electron paramagnetic resonance (EPR) O-rings with neoprene O-rings, and do not use freon to clean system components

Petrogenesis of Pleisto-Holocene Basalts and Basaltic Andesites from Newberry Volcano, Oregon

Newberry Volcano (43.7°N, 121.3°W) is a Cascade rear arc volcano in central Oregon that covers nearly 2,000 km2 and represents a volume of roughly 200 km3 of mostly mafic magmas. This composite shield dramatically exceeds the volume of all other Cascade volcanoes, except for Medicine Lake Volcano in Northern California. Newberry began forming about 400 ka with the last eruption ending at 1.3 ka (Donnelly-Nolan et al., 2011). Proposed tectonic models that explain the origin of the volcano are as follows: 1. Mantle decompression melting from lithospheric extension (Xue and Allen, 2006); 2. Slab window or tear in the lithosphere (Tian and Zhao, 2012); 3. Subduction-induced counterflow of the Yellowstone plume (Jordan et al., 2004). The research goal of this study is to test these models to better understand the mantle processes and petrogenetic origin of Newberry Volcano by analyzing the mafic lavas from sequential eruptions ranging in age from ~400 ka to 7 ka. Thirty-five (35) samples were collected and whole-rock geochemical data has been obtained by inductively coupled plasma mass spectrometry (ICP-MS) for major and trace elements. Isotopic analyses of eight (8) samples were conducted via TIMS and MC-ICPMS. Petrographic analyses of rock thin sections exhibit olivine and plagioclase phenocrysts throughout the sample majority. Major element classification on a silica-alkali diagram shows that basalts, trachybasalt, basaltic andesites, basaltic trachyandesites and andesite (SiO2=48.2-57.0%; Na2O+K2O=3.2-6.3%) provide evidence for crystal fractionation within the Newberry mafic suite and potentially a positive trend in SiO2 over time. Enrichments in LREE (La/Yb=3-9), LILE (Sr/La=19-60; Ba/La=13-31) and depletions in HFSE (Ba/Ta=147-1064; La/Ta=11-36) indicate a role for subduction related processes and the possible addition of slab-derived fluids and/or sediments to the mantle source. 87Sr/86Sr (0.7031-0.7036), 143Nd/144Nd (0.5129-0.5130), 206Pb/204Pb (18.82-19.08), 207Pb/204Pb (15.56-15.60) and 208Pb/204Pb (38.43-38.61) indicate a slightly depleted, E-MORB-like asthenospheric source region beneath Newberry. The data presented report that Newberry basalts and basaltic andesites are chemically similar to calc-alkaline basalts from Medicine Lake Volcano (Donnelly-Nolan et al., 2008) and other arc basalts from the central Cascade Range (Bacon et al., 1997) and are most likely produced by rear-arc flux melting of the E-MORB-like asthenospheric wedge from dehydration of the subducting Juan de Fuca Plate

A Feasibility Study of Using Air-lift Pumps for Aeration, Degasification, and Water Movement in a Recirculating Aquaculture System

A feasibility study of using air-lift pumps for water movement, aeration, and degasification in a recirculating aquaculture system was conducted. Fluid delivery tests of various air-lift configurations indicated that water flow is a function of the submergence depth, lift height, and air injection rate. The air-lift units were found to transfer 02 at only 1/5 to 1/2 the rate of comparably operated open-water aeration systems. The standard oxygen transfer rate (SOTR) increased with air injection from 1-7 scftn, however, the energy usage also increased, yielding a reduction in the standard aeration efficiency (SAE) from over 2 to less than 0.5 kg 02 / kw hr. Tests comparing airstones to open-ended tubes as air-lift injectors indicated a similar performance. The carbon dioxide stripping rate increased with air flow while the efficiency decreased. The short-term C02 transfer was also shown to decrease as the system alkalinity increased. A set of empirical equations was developed to predict the water flow and steady state dissolved oxygen and carbon dioxide concentrations for any number of air-lifts used in a typical recirculating system. The air-lift configuration modeled was a 2 diameter pipe submerged 36” with a 6 lift operated at I - 5 scfm of air injection. The recirculating system was assumed to be stocked at a fish density of 0.5 Ib/gal, fed at 3% per day, and maintained at 30 °C. The minimum oxygen concentration was assumed to be 6 mg/1 and the carbon dioxide tolerance was selected as 5 mg/1. The predicted air-lift performance in such a system was compared to the estimated water flow and gas exchange demands and the aeration requirement was found to be the controlling design parameter

Black Hartford: 1843 - 1860

Objectives stated in paper\u27s introduction: I. To determine if material was available on BLack Hartford in periods before the twentieth century II. \u27To obtain and relate knowledge as to the particular procedures necessary and useful in doing research in our area of concern. III . To develop a basic picture of Black Hartford 1343-1860, in its physical, cultural, economic and educational aspects.

Morphology of Hydrodynamic Winds: A Study of Planetary Winds in Stellar Environments

Bathed in intense ionizing radiation, close-in gaseous planets undergo hydrodynamic atmospheric escape, which ejects the upper extent of their atmospheres into the interplanetary medium. Ultraviolet detections of escaping gas around transiting planets corroborate such a framework. Exposed to the stellar environment, the outflow is shaped by its interaction with the stellar wind and by the planet's orbit. We model these effects using Athena to perform 3-D radiative-hydrodynamic simulations of tidally-locked hydrogen atmospheres receiving large amounts of ionizing extreme-ultraviolet flux in various stellar environments for the low-magnetic-field case. Through a step-by-step exploration of orbital and stellar wind effects on the planetary outflow, we find three structurally distinct stellar wind regimes: weak, intermediate, and strong. We perform synthetic Lyman-$\alpha$ observations and find unique observational signatures for each regime. A weak stellar wind$\textrm{---}$which cannot confine the planetary outflow, leading to a torus of material around the star$\textrm{---}$has a pre-transit, red-shifted dayside arm and a slightly redward-skewed spectrum during transit. The intermediate regime truncates the dayside outflow at large distances from the planet and causes periodic disruptions of the outflow, producing observational signatures that mimic a double transit. The first of these dips is blue-shifted and precedes the optical transit. Finally, strong stellar winds completely confine the outflow into a cometary tail and accelerate the outflow outwards, producing large blue-shifted signals post-transit. Across all three regimes, large signals occur far outside of transit, offering motivation to continue ultraviolet observations outside of direct transit.Comment: 33 pages, 21 figures (7 of which have embedded movies viewable with Adobe Acrobat Pro), Submitted to Ap

Dynamic Response Characteristics of Local Capacitive Measurement Devices with Application to CFD Validation

The Two-Fluid Model (TFM) approach to modeling fluid-solid systems holds great promise as a means to simulate arbitrary systems, thus greatly reducing design and scale-up efforts. Unfortunately, comprehensive experimental validations of these models are still in short supply. This work addresses this issue by proposing a framework under which to relate computational fluid dynamics model results with experimental measurements on a one-to-one basis. Specifically this is performed for the case of local solids concentration transients in a bench-scale bubbling fluidized bed. The manner in which this comparison is performed has implications for the conclusions that may be drawn for a given validation effort