Thomas P. Seager

Integrating risk and resilience approaches to catastrophe management in engineering systems

Recent natural and man-made catastrophes, such as the Fukushima nuclear power plant, flooding caused by Hurricane Katrina, the Deepwater Horizon oil spill, the Haiti earthquake, and the mortgage derivatives crisis, have renewed interest in the concept of resilience, especially as it relates to complex systems vulnerable to multiple or cascading failures. Although the meaning of resilience is contested in different contexts, in general resilience is understood to mean the capacity to adapt to changing conditions without catastrophic loss of form or function. In the context of engineering systems, this has sometimes been interpreted as the probability that system conditions might exceed an irrevocable tipping point. However, we argue that this approach improperly conflates resilience and risk perspectives by expressing resilience exclusively in risk terms. In contrast, we describe resilience as an emergent property of what an engineering system does, rather than a static property the system has. Therefore, resilience cannot be measured at the systems scale solely from examination of component parts. Instead, resilience is better understood as the outcome of a recursive process that includes: sensing, anticipation, learning, and adaptation. In this approach, resilience analysis can be understood as differentiable from, but complementary to, risk analysis, with important implications for the adaptive management of complex, coupled engineering systems. Management of the 2011 flooding in the Mississippi River Basin is discussed as an example of the successes and challenges of resilience-based management of complex natural systems that have been extensively altered by engineered structures.

Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion

Lignocellulosic biomass can be converted into ethanol through either biochemical or thermochemical conversion processes. Biochemical conversion involves hydrolysis and fermentation while thermochemical conversion involves gasification and catalytic synthesis. Even though these routes produce comparable amounts of ethanol and have similar energy efficiency at the plant level, little is known about their relative environmental performance from a life cycle perspective. Especially, the indirect impacts, i.e. emissions and resource consumption associated with the production of various process inputs, are largely neglected in previous studies. This article compiles material and energy flow data from process simulation models to develop life cycle inventory and compares the fossil fuel consumption, greenhouse gas emissions, and water consumption of both biomass-to-ethanol production processes. The results are presented in terms of contributions from feedstock, direct, indirect, and co-product credits for four representative biomass feedstocks i.e., wood chips, corn stover, waste paper, and wheat straw. To explore the potentials of the two conversion pathways, different technological scenarios are modeled, including current, 2012 and 2020 technology targets, as well as different production/co-production configurations. The modeling results suggest that biochemical conversion has slightly better performance on greenhouse gas emission and fossil fuel consumption, but that thermochemical conversion has significantly less direct, indirect, and life cycle water consumption. Also, if the thermochemical plant operates as a biorefinery with mixed alcohol co-products separated for chemicals, it has the potential to achieve better performance than biochemical pathway across all environmental impact categories considered due to higher co-product credits associated with chemicals being displaced. The results from this work serve as a starting point for developing full life cycle assessment model that facilitates effective decision-making regarding lignocellulosic ethanol production.

A decision-directed approach for prioritizing research into the impact of nanomaterials on the environment and human health

The emergence of nanotechnology has coincided with an increased recognition of the need for new approaches to understand and manage the impact of emerging technologies on the environment and human health. Important elements in these new approaches include life-cycle thinking, public participation and adaptive management of the risks associated with emerging technologies and new materials. However, there is a clear need to develop a framework for linking research on the risks associated with nanotechnology to the decision-making needs of manufacturers, regulators, consumers and other stakeholder groups. Given the very high uncertainties associated with nanomaterials and their impact on the environment and human health, research resources should be directed towards creating the knowledge that is most meaningful to these groups. Here, we present a model (based on multi-criteria decision analysis and a value of information approach) for prioritizing research strategies in a way that is responsive to the recommendations of recent reports on the management of the risk and impact of nanomaterials on the environment and human health.

Measurable resilience for actionable policy.

nprecedented losses associated with adverse events suchas natural disasters and cyber-attacks have focusedattention on new approaches to mitigating damages. Whereasthe dominant analytic and governance paradigm of the lastseveral decades has been risk analysis, recently rhetoric hasshifted toward the necessity of understanding and designing forresilience.

A life-cycle energy analysis of single wall carbon nanotubes produced through laser vaporization

The energy consumed to produce and purify a kilogram of laser vaporization SWCNTs at the laboratory scale was found to be 0.13–0.19 GWh/kg under standard production conditions, with 0.114 GWh/kg coming from electrical energy. Most of the energy consumption results from thermal and resistive losses of the laser and single zone furnace in use. The time and temperature of final oxidation of the material was found to greatly affect purity while only slightly affecting the energy consumed. Although the energy consumption for laser vaporization is comparable to other synthesis processes, scale-up of production from laboratory to manufacturing rates may result in substantial efficiency gains. Additional energy savings may be realized from the capture and recovery of gases, solvents and other materials that are currently discarded.

Land use and geospatial aspects in life cycle assessment of renewable energy

Renewable energy systems such as wind, solar and biomass are significantly more land intensive than traditional fossil fuels. Moreover, their environmental implications are highly geographically heterogeneous. Consequently, they present a significant challenge to existing life cycle assessment techniques. Four specific issues are identified in this paper: determining changes in land use due to increased production of renewable energy, characterizing land use impacts, understanding geographic variability in inventory data, and modeling energy distribution effects. This paper reviews the extent of recent research activity in each of these areas as it applies to wind, solar, bioenergy or life cycle assessment in general. Some areas, such as land use needed for distribution of wind or solar energy, have received little or no research activity, despite an increased level of concern in political or policy arenas. This deficiency will be addressed in a new National Science Foundation workshop planned for September 2009 in Boston MA.

Sources of variability and uncertainty in LCA of single wall carbon nanotubes for Li-ion batteries in electric vehicles

Production alternatives for single-walled carbon nanotubes (SWCNT) such as chemical vapor deposition, laser, arc and flame, vary widely in material and energy yields, catalyst requirements and product characteristics. The overall environmental profile must be assessed relative to performance in a specific end-use application, such as lithium ion batteries for electric or plug-in hybrid vehicles. Although in general SWCNT have several properties that make them attractive for transportation applications, production is a material- and energy-intensive process. High-yield synthesis pathways may be environmentally inefficient if extensive purification is required. Life cycle assessment (LCA) is an approach to quantifying the environmental trade-offs engendered by technology substitution. However, it is essential to recognize that the results of LCA for one type of SWCNT may not be applicable to SWCNT of different purity, length, diameter, chirality or conductivity. This paper discusses sources of variability and uncertainty in production of SWCNT and makes several recommendations with regard to LCA of nanomaterials.

Developing a social capital metric for use in an educational computer game

To address the educational challenges of Millennial Generation students, there has been an increased willingness at many universities to experiment with pedagogical strategies that depart from a traditional “learning by listening” model, to more innovative methods involving active learning through computer games. We hypothesize that to acquire the skills necessary to manage social sustainability, students must be engaged in active learning exercises that foster a high level of social interaction. This has led to the development of an educational computer game, entitled Shortfall, which simulates a business milieu for testing alternative paths regarding the principles of sustainability. This paper examines social sustainability in the context of industry and through the lens of a capital-based theory of sustainability. Using a capital-based theory, the analysis of social sustainability is narrowed to the concept of social capital. The current methodologies used for measuring social capital are reviewed, and a prospective metric using a peer evaluation survey, unique to Shortfall, is developed.

Innovation in the Knowledge Age: implications for collaborative science

Current trends validate the notion that multifaceted, multimodal interdisciplinary collaborations lead to increased research productivity in publications and citations, compared to those achieved by individual researchers. Moreover, it may be that scientific breakthroughs are increasingly achieved by interdisciplinary research teams. Nonetheless, despite the perceived importance of collaboration and its bibliometric benefits, today’s scientists are still trained to be autonomous, work individually, and encourage their graduate students to do the same—perpetuating values which impede the creation of collaborative space between disciplines. As a consequence, scientists working in teams typically report serious obstacles to collaboration. This paper builds off of recent recommendations from a 2015 National Academies report on the state of team science which emphasizes greater definition of roles, responsibility, accountability, goals, and milestones. However, these recommendations do not address the subjective, relational components of collaboration which can drive innovation and creativity. The relational side of collaboration is key to understanding the capacity and capabilities of the knowledge workers, such as scientists and engineers, who comprise interdisciplinary research teams. The authors’ recommendations, grounded in organizational communication and knowledge worker literature, include a renewed focus on the process of organizing through communication rather than focusing on organization as an outcome or consequence of teamwork, leading and cultivating team members rather than managing them, and the need to address self-driven, rather than external, motivations to engage in knowledge work.

Intergroup Cooperation in Common Pool Resource Dilemmas

Fundamental problems of environmental sustainability, including climate change and fisheries management, require collective action on a scale that transcends the political and cultural boundaries of the nation-state. Rational, self-interested neoclassical economic theories of human behavior predict tragedy in the absence of third party enforcement of agreements and practical difficulties that prevent privatization. Evolutionary biology offers a theory of cooperation, but more often than not in a context of discrimination against other groups. That is, in-group boundaries are necessarily defined by those excluded as members of out-groups. However, in some settings human’s exhibit behavior that is inconsistent with both rational economic and group driven cooperation of evolutionary biological theory. This paper reports the results of a non-cooperative game-theoretic exercise that models a tragedy of the commons problem in which groups of players may advance their own positions only at the expense of other groups. Students enrolled from multiple universities and assigned to different multi-university identity groups participated in experiments that repeatedly resulted in cooperative outcomes despite intergroup conflicts and expressions of group identity. We offer three possible explanations: (1) students were cooperative because they were in an academic setting; (2) students may have viewed their instructors as the out-group; or (3) the emergence of a small number of influential, ethical leaders is sufficient to ensure cooperation amongst the larger groups. From our data and analysis, we draw out lessons that may help to inform approaches for institutional design and policy negotiations, particularly in climate change management.