8,804 research outputs found
Tim Begue, Salt Lake City, UT: an interview by Greg Smoak, 29 April 2014
No full textTranscript (35 pages) of an interview by Greg Smoak with Tim Begue on April 29, 2014, in Salt Lake City, Utah
Oral history interview with Tim Begue, conducted by Greg Smoak (audio and transcript)
No full textMr. Begue talks about his early life and his first experiences at Great Salt Lake when he went sailing with his family. He worked as a river guide and his boss at one of the companies suggested they go into the brine shrimp business. Tim talks about starting to fish for brine shrimp and the beginnings of the business he started, Prime Artemia. He describes the overall process of brine shrimping, from the work and competition on the lake to the processing and distribution. Mr. Begue talks about closing industry on the lake and the process of acquiring a certificate of registration to fish. He sold his business in 1996. Finally, Tim describes some of his favorite places on Great Salt Lake and recounts some of his favorite experiences
Does Complex Hydrology Require Complex Water Quality Policy? NManager Simulations for Lake Rotorua
No full textThis paper examines six different approaches to nutrient management, and simulates the economic costs and environmental impacts associated with them using NManager, a partial equilibrium simulation model developed by Motu and NIWA, the National Institute for Water and Atmospheric Research. We focus on Lake Rotorua in the Bay of Plenty in New Zealand, where the regional council is concerned with the decline in the lake's water quality and has set a goal to restore the lake to its condition during the 1960s. Reaching this goal will require significant reductions in the amount of nutrients discharged into the lake, especially from non-point sources such as farm land. Managing water quality is made difficult by the presence of groundwater lags in the catchment: nutrients that leach from the soil arrive at the lake over multiple years. The mitigation schemes we consider are land retirement, requiring best practice, explicit nitrogen limits on landowners, a simple nutrient trading scheme, and two more complex trading schemes that account for groundwater lags. We demonstrate that best practice alone is not sufficient to meet the environmental target for Lake Rotorua. Under an export trading scheme, the distribution of mitigation across the catchment is more cost effective than its distribution under explicit limits on landowners or land retirement. However, the more complex trading schemes do not result in sufficient, or sufficiently certain, gains in cost effectiveness over the simple trading scheme to justify the increase in complexity involved in their implementation.groundwater, Lake Rotorua, model, nutrients, nutrient trading, water quality, non-point source pollution
Tim Strong, Salt Lake City, Utah: an interview by Eric Halcomb, 22 January 2013
No full textTranscript (23 pages) of an interview by Erin Halcomb with Tim Strong on January 22, 2013, in Salt Lake City, Utah
Tim DeChristopher, Salt Lake City, UT: an interview by Greg Smoak, 21 November 2014
No full textTranscript (36 pages) of an interview by Greg Smoak with Tim DeChristopher on March 31, 2009, in Salt Lake City, Utah
Methane oxidation and emission in Lake Lugano (Southern Switzerland) : a lipid biomarker and isotopic approach
No full textMethane is an important greenhouse gas in Earth's atmosphere. The sources of atmospheric methane are largely biogenic, being produced under anoxic conditions by methanogenic Archaea. Wetlands, which include lakes, are important contributors to the atmospheric methane budget, since they commonly feature anoxic sediments or bottom water. Methane oxidising bacteria at the interface between oxic and anoxic sediments and water limit the efflux of methane. Furthermore, in the oceans, methane is oxidised anaerobically by Archaea, in a process coupled to sulfate reduction. In freshwater environments, where sulfate concentrations are orders of magnitude lower, this process is not thermodynamically favourable, and archaeal anaerobic oxidation of methane is often absent. It has been proposed in certain lake environments, however, that anaerobic oxidation of methane does take place.
One lake in which anaerobic oxidation of methane was proposed is the northern basin of Lake Lugano, southern Switzerland. Anaerobic oxidation of methane in this basin is explored in chapter 2 of this PhD thesis. Indeed we found methane concentration and carbon isotopic composition profiles characteristic of methane oxidation in the anoxic hypolimnion, more than 30 m below the interface between the oxic and anoxic waters. In addition, microbial biomass at these depths showed carbon isotope signatures of methane-derived carbon (d13C-values as low as -70‰ in C16:1 fatty acids), indicating that methane is used as a carbon source. However, no methane oxidation took place in incubation experiments under anoxic conditions. Addition of alternative potential electron acceptors did not stimulate methane oxidation, and methane oxidation was only observed in the presence of oxygen. Instead, we propose that episodic introduction of oxygenated water into the anoxic hypolimnion sustains a community of aerobic methanotrophs.
Carbon derived from methane oxidation has been shown in several studies to constitute an important carbon input to aquatic ecosystems. In the studies reported in chapters 2 and 3, compound specific stable carbon isotope analysis of lipid biomarkers was used to trace methane-derived carbon through the ecosystems at redox interfaces and in the anoxic hypolimnion of Lake Lugano. In the monomictic southern basin (chapter 3), an anoxic benthic nepheloid layer develops during the period of water column stratification. This layer was found to be derived from microbial production in the hypolimnion. Methane oxidising bacteria constituted up to 30% of total microbial cell numbers in the nepheloid layer, and 77% to 96% of the organic carbon in this layer was methane-derived. High rates of aerobic methane oxidation at the top of the anoxic nepheloid layer led to an oxygen consumption that was greater than the downward diffusion, causing the anoxic nepheloid layer to expand. Bacterial aerobic methanotrophs migrate upwards through the water column with the interface between the oxic hypolimnion and the anoxic nepheloid layer.
The extent of emission of methane to the atmosphere depends on the totality of sinks and sources in the lake basin. In both the northern and the southern basin of Lake Lugano, large amounts of methane are emitted from the sediments into the bottom water. However, consumption by aerobic methanotrophs at the oxic-anoxic redoxcline is near complete, and during stratified conditions, no methane escapes to the epilimnion. On the other hand, methane super-saturation in the surface water was observed throughout the year. Chapter 4 describes the results of three mapping campaigns of surface water methane concentrations in the northern basin of Lake Lugano, in spring and autumn. Additionally, methane concentration and carbon isotopic composition were measured on depth profiles down to 40 m depth in transects across the lake basin. Methane fluxes to the atmosphere were calculated from surface water concentration and wind speed. At a standardised wind speed of 1.6 m s-1 (average wind speed during the period from May until October) fluxes to the atmosphere were significantly higher in autumn (44 and 97 micromol m-2 d-1 in October 2011 and October 2012, respectively) than in spring (7 micromol m-2 d-1, May 2012). This difference is in part due to higher concentrations in autumn than in spring, and in part a result of a stronger dependence of the transfer velocity on buoyancy flux when the surface water cools. The source of methane in the surface water could not be determined with certainty. It is possible that internal waves at the thermocline induce friction at the sediment-water interface in the littoral zone, which leads to increased outgassing of sedimentary methane. However, the northern basin of Lake Lugano has steep shores along large parts of the basin, which offer little space for deposition of sediments, and the possibility of in situ production of methane in the water column must be considered
Do dolphins benefit from nonlinear mathematics when processing their sonar returns?
No full textAn interview with author Tim Leighton about the paper
Opportunities for linking young surveyors across professional surveying member organisations and FIG
No full textTim Di Muzio on 'Sabotage'
No full textIn a series of essays published in 2013 and 2014 on capitaspower.com, political economist Tim Di Muzio explored the concept of ‘sabotage’ as it applies to capitalist power. I recently rediscovered these essays and was so impressed by them that I have reposted them here as a single piece.
About the author: Tim Di Muzio is a researcher at the University of Wollongong. He is the author of numerous books, including Debt as power, Carbon capitalism, and The 1% and the Rest of us
No.189, Dick Crookston, interview by Tim Larson
No full textTranscript (35 pages) of interview by Tim Larson with Dick Crookston of KUTV in Salt Lake City on June 29, 1988. This interview is no. 189 in the Everett L. Cooley Oral History Project, and tape no. 791Crookston discusses his career at KUTV doing propwork and eventually as creative director, his presidency of the Salt Lake Advertising Club, and various people he worked with, including George Hatch. Interviewer: Tim Larso
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