Characterizing the effects of turbulence on sediment oxygen and sediment nitrate demand using flow-through reactors

Onondaga Lake has received the municipal effluent and industrial waste from the city of Syracuse for more than a century. Historically, 75 metric tons of mercury were discharged to the lake by chlor-alkali facilities. These legacy deposits of mercury now exist primarily in the lake sediments. Under anoxic conditions, methylmercury is produced in the sediments and can be released to the overlying water. Natural sedimentation processes are continuously burying the mercury deeper into the sediments. Eventually, the mercury will be buried to a depth where it no longer has an impact on the overlying water. In the interim, electron acceptor amendment systems can be installed to retard these chemical releases while the lake naturally recovers. Electron acceptor amendment systems are designed to meet the sediment oxygen demand in the sediment and maintain manageable hypolimnion oxygen concentrations. Historically, designs of these systems have been under designed resulting in failure. This stems from a mischaracterization of the sediment oxygen demand. Turbulence at the sediment water interface has been shown to impact sediment oxygen demand. The turbulence introduced by the electron amendment system can thus increase the sediment oxygen demand, resulting in system failure if turbulence is not factored into the design. Sediment cores were gathered and operated to steady state under several well characterized turbulence conditions. The relationship between sediment oxygen/nitrate demand and turbulence was then quantified and plotted. A maximum demand was exhibited at or above a fluid velocity of 2.0 mm•s-1. Below this velocity, demand decreased rapidly with fluid velocity as zero velocity was approached. Similar relationships were displayed by both oxygen and nitrate cores.

Arctic network builders : the Arctic Coal Company's operations on Spitsbergen and its relationship with the environment

In 1906, two American industrialists, John Munroe Longyear and Frederick Ayer, formed the Arctic Coal Company to make the first large scale attempt at mining in the high-Arctic location of Spitsbergen, north of the Norwegian mainland. In doing so, they encountered numerous obstacles and built an organization that attempted to overcome them. The Americans sold out in 1916 but others followed, eventually culminating in the transformation of a largely underdeveloped landscape into a mining region. This work uses John Law’s network approach of the Actor Network Theory (ANT) framework to explain how the Arctic Coal Company built a mining network in this environmentally difficult region and why they made the choices they did. It does so by identifying and analyzing the problems the company encountered and the strategies they used to overcome them by focusing on three major components of the operations; the company’s four land claims, its technical system and its main settlement, Longyear City. Extensive comparison between aspects of Longyear City and the company’s choices of technology with other American examples place analysis of the company in a wider context and helps isolate unique aspects of mining in the high-Arctic. American examples dominate comparative sections because Americans dominated the ownership and upper management of the company.

Heikinpäivä in Hancock

Each January in Hancock, Michigan, the Heikinpäivä Midwinter Festival offers local residents three weeks of activities highlighting the continuing role Finnish culture has in the area. Utilizing a set of fading Finnish midwinter traditions surrounding the day of Heikki, or Henrik, this festival has grown from a brief day-long gathering to a long period of activity incorporating films, craft and cooking classes, religious services, and more traditional festival events such as a parade, games, feasting, music, and dancing. This festival has complex origins in more commonplace agricultural traditions brought from Finland by immigrants, which are often no longer commonly remembered in Finland to this day. In this paper, I will examine the complex history of this festival both through its Finnish origins and through its current incarnation in Michigan. Through this festival, we can see the role Finnish heritage has as a simultaneous marker of cultural pride and deprecation. The place Finnish heritage has as a tool in community and economic development in the City of Hancock and the wider region will also be explored. Finally, the function of the festival as a means of maintaining traditions seemingly doomed to fade with time will also be explored.