Michigan State University

About: Michigan State University is a education organization based out in East Lansing, Michigan, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 60109 authors who have published 137074 publications receiving 5633022 citations. The organization is also known as: MSU & Michigan State.

Improved fuel cell and electrode designs for producing electricity from microbial degradation.

Abstract: A new one-compartment fuel cell was composed of a rubber bunged bottle with a center-inserted anode and a window-mounted cathode containing an internal, proton-permeable porcelain layer. This fuel cell design was less expensive and more practical than the conventional two-compartment system, which requires aeration and a ferricyanide solution in the cathode compartment. Three new electrodes containing bound electron mediators including a Mn(4+)-graphite anode, a neutral red (NR) covalently linked woven graphite anode, and an Fe(3+)-graphite cathode were developed that greatly enhanced electrical energy production (i.e., microbial electron transfer) over conventional graphite electrodes. The potentials of these electrodes measured by cyclic voltametry at pH 7.0 were (in volts): +0.493 (Fe(3+)-graphite); +0.15 (Mn(4+)-graphite); and -0.53 (NR-woven graphite). The maximal electrical productivities obtained with sewage sludge as the biocatalyst and using a Mn(4+)-graphite anode and a Fe(3+)-graphite cathode were 14 mA current, 0.45 V potential, 1,750 mA/m(2) current density, and 788 mW/m(2) of power density. With Escherichia coli as the biocatalyst and using a Mn(4+)-graphite anode and a Fe(3+)-graphite cathode, the maximal electrical productivities obtained were 2.6 mA current, 0.28 V potential, 325 mA/m(2) current density, and 91 mW/m(2) of power density. These results show that the amount of electrical energy produced by microbial fuel cells can be increased 1,000-fold by incorporating electron mediators into graphite electrodes. These results also imply that sewage sludge may contain unique electrophilic microbes that transfer electrons more readily than E. coli and that microbial fuel cells using the new Mn(4+)-graphite anode and Fe(3+)-graphite cathode may have commercial utility for producing low amounts of electrical power needed in remote locations.

Direct Measurement of Oxygen Profiles and Denitrification Rates in Soil Aggregates

Abstract: An oxygen microelectrode was modified to measure O concentrations in wet aggregates of a silt loam soil. The microelectrode tip had an O-permeable membrane opening 3 µm in diameter, and O measurements could be made in as little as 0.1-mm increments to a depth of 12 mm. When aggregates were incubated in air, steep O gradients usually occurred over very small distances from the aggregate surface. The smallest aggregate exhibiting an anaerobic center had a radius of 4 mm, although small aggregates (radius ≤ 6 mm) were generally oxic. Larger aggregates (radius ≥ 10 mm) often had measureable anaerobic centers, with the exception of those from a native prairie soil which exhibited irregular O profiles and had aerobic centers, apparently due to O intrusion caused by old root channels. Oxygen profiles obtained in 45 degree increments around an aggregate circumference were used to construct contour maps of O concentrations within the aggregate. Oxygen gradients were somewhat asymmetric, suggesting nonuniformly distributed sites of O consumption. An average intra-aggregate O diffusion coefficient of 8.5 × 10 cm · s was measured for water-saturated aggregates. The radii of anaerobic centers within several aggregates, measured directly with the electrode, correlated with those calculated from a model of radial diffusion using measured respiration rates and the intra-aggregate O diffusion coefficient. Anaerobic centers were present in all aggregates that denitrified, but not all aggregates with anaerobic zones denitrified. The denitrification rate did not correlate with the size of the anaerobic zone, indicating that factors other than anaerobic volume contributed to the observed rates.

The Influence of Task Interruption on Individual Decision Making: An Information Overload Perspective

Abstract: Interruptions are a common aspect of the work environment of most organizations. Yet little is known about how interruptions and their characteristics, such as frequency of occurrence, influence decision-making performance of individuals. Consequently, this paper reports the results of two experiments investigating the influence of interruptions on individual decision making. Interruptions were found to improve decision-making performance on simple tasks and to lower performance on complex tasks. For complex tasks, the frequency of interruptions and the dissimilarity of content between the primary and interruption tasks was found to exacerbate this effect. The implications of these results for future research and practice are discussed.

Gate-variants of Gated Recurrent Unit (GRU) neural networks

Abstract: The paper evaluates three variants of the Gated Recurrent Unit (GRU) in recurrent neural networks (RNNs) by retaining the structure and systematically reducing parameters in the update and reset gates. We evaluate the three variant GRU models on MNIST and IMDB datasets and show that these GRU-RNN variant models perform as well as the original GRU RNN model while reducing the computational expense. In this comparative study, we simply refer to the three variants as, respectively, GRU1, GRU2, and GRU3 RNNs.