This paper presents findings of a study of high school students participating in a tablet PC (TPC) programme. Primary areas of interest were students' experiences with and attitudes about the TPCs, physical discomfort associated with use of TPCs and temporal and task-driven patterns of TPC use. Data were collected via questionnaire and computer use-monitoring software. Results showed students' attitudes were generally quite positive towards the TPCs, although they did not tend to think TPCs had improved their grades, few disagreed that TPCs were a distraction in class, and visual and musculoskeletal discomfort was prevalent. Understanding how to use the TPC and recognizing its organizational capacity were associated with several positive attitudes towards the TPC, including making school more enjoyable. Children's exposure to computers will only increase, so study of the many dimensions of their impact is critical in order to understand what is effective, constructive and healthful for children.

By-product synergy (BPS) is an industrial ecology practice that involves utilization of industrial by-products as feedstocks for other industrial processes. A novel decision support tool is developed to analyze BPS networks that involve material processing and transport among regional clusters of companies. Mathematical programming techniques are used to determine the optimal network design and the material flows that minimize total cost or environmental impacts. This methodology is incorporated into a graphical software package called EcoFlow TM . The tool has been applied to model and analyze available synergies in an existing BPS network centered in Kansas City, Missouri. A base case, which assumes no synergies, is compared with the optimal BPS solution found by Eco-Flow TM . The results for Kansas City suggest that when companies in the network cooperate to optimize the system profitability, up to $15 million per year of savings are possible. The findings also indicate that the BPS approach would result in 29% reduction in total cost, 25.8% reduction in average company cost, 30% reduction in carbon dioxide (CO 2 ) emissions, and 37% reduction in waste to landfill. The modeling approach is being extended to better represent the dynamics of industrial and ecological processes.

The City of Columbus owns and operates two wastewater treatment plants (WWTPs), the Southerly WWTP (SWWTP) and the Jackson Pike WWTP (JPWWTP). Like many US cities, Columbus is facing difficult management and operational decisions due to escalating energy prices and heightened awareness of the social and environmental impacts of treating and disposing of municipal biosolids. The development and the application of EcoFlow™, a material flow optimization tool, represents a novel use of existing operations data and an application of network theory to facilitate decision-making by synthesizing financial, environmental and technical process data. This tool provides an analytical framework to solve a broad variety of resource and waste management problems.Due to both economic and environmental concerns, the City of Columbus is closely scrutinizing the efficiency of its biosolids operations in order to deliver sustainable solutions for future wastewater treatment. As part of Columbus' Solids Treatment and Utilization Master Plan, the Eco-Flow™ modeling software, developed by the Center for Resilience at The Ohio State University, was applied to the management of biosolids generated from the two WWTPs. The model provided guidance for improving of the current disposal methods employed and analyzed the feasibility of implementing many new technologies. The model also optimized operations relative to three main objectives associated with biosolids management: cost reduction, energy conservation and greenhouse gas (GHG) reduction.

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