Research paper accepted to the Journal of Industrial Ecology

BiSSL alumn Colton Brehm (MS graduate May 2020) just had his full-length research paper accepted in the Journal of Industrial Ecology! The paper, titled “Nestedness in eco-industrial networks: exploring linkage distribution to promote sustainable industrial growth,” investigates the use of nestedness – a structural characteristic of ecological food webs, to guide the design of Eco-Industrial Networks (EINs) to improve their sustainability, creating a more circular economy.

Abstract: “Eco-Industrial Networks (EINs) have gained support as a solution that simultaneously reduces environmental burdens and promotes economic interests. EINs operate under a mutualistic framework, where waste materials and energy are exchanged between industries to their mutual benefit, creating a diverse web of flows. Recent studies have focused on analogies between food webs (FWs) and EINs, measuring a network’s success at ecological imitation as representative of its sustainability. Studies have focused heavily on the number of links and nodes in a network, but have neglected the economic reality that each investment comes at the opportunity cost of all alternatives. This analysis focuses on the nestedness metric as used by ecologists to address this pivotal facet to the FW-EIN analogy. Nestedness describes an ecological strategy for the position of links between nodes in a network in a way that maximizes network cycling for a given number of connections. This metric presents many advantages for EIN design and analysis, including maturity independence, size normalization, and a strong statistical record in highly mutualistic ecological systems. Application of nestedness to EINs indicates a lower presence of nested structures and more randomness than what is typically seen in FWs. The industrial networks also display a correlation between high nestedness and internal cycles, suggesting that the reuse of materials and energy in EINs can be improved upon by increasing the nestedness of structures.”

Brehm, C., & Layton, A. (2020). “Nestedness in eco-industrial networks: exploring linkage distribution to promote sustainable industrial growth.” Journal of Industrial Ecology. DOI: 10.1111/jiec.13057

BiSSL Student Led Publication in Journal of Cleaner Production

Congratulations to BiSSL alumni Tirth Dave (MS graduate December 2019) on the publication of his paper in the Journal of Cleaner Production! “Designing ecologically-inspired robustness into a water distribution network” covers Tirth’s work on bio-inspired network design coupled with modeling of a water distribution network, showing that we can draw inspiration from nature to improve the resilience and reduce freshwater use in industrial resource networks.

ABSTRACT: Eco-Industrial Parks (EIPs), network of industries that collaborate by utilizing each other’s byproducts and wastes, are highly desirable for both the industries themselves, their environment, and governments due to their economic, environmental, and social advantages. Previous work has shown that EIPs are not as successful as they could be in terms of mimicking the behavior of biological ecosystems, highlighting that more work needs to be done for EIPs to truly mimic their biological-counterparts. The Kalundborg EIP, located in Kalundborg, Denmark, is a well documented example of an EIP with long-term success. Using the water network within the Kalundborg EIP as a case study, two bio-inspired networks are selected from an optimization based on the ecosystem metric robustness. The bio-inspired solutions are compared with a traditionally cost-minimized solution to understand what bio-inspired design can offer when a network is disturbed. Disturbances such as connection breakages and industry shutdowns are tested, showing that the bio-inspired designs require minimal recovery costs – in stark contrast to the traditional network solution. The results show that the bio-inspired designs reduce the network’s dependence on a scarce import (freshwater) and have higher overall network resilience in the event of disturbances. The three network solutions are discussed from a ecological perspective, explaining differences from the standpoint of ecosystem characteristics. The analysis highlights the benefits of using ecology to understand the nature of and improve the design of industrial networks.

JCP (2020) “Designing ecologically-inspired robustness into a water distribution network” Dave, T. and Layton, A.

BiSSL Student Led PLOS ONE Publication

We can finally share this open access PLOS ONE publication “A quantitative engineering study of ecosystem robustness using thermodynamic power cycles as case studies” written with MS BiSSL alumni Varuneswara Panyam (TAMU graduate December 2019). Understanding the characteristics of biological systems from an engineering perspective is an important part of bio-inspired engineering design!

ABSTRACT: Human networks and engineered systems are traditionally designed to maximize efficiency. Ecosystems on the other hand, achieve long-term robustness and sustainability by maintaining a unique balance between pathway efficiency and redundancy, measured in terms of the number of flow pathways available for a given unit of flow at any node in the network. Translating this flow-based ecosystem robustness into an engineering context supports the creation of new robust and sustainable design guidelines for engineered systems. Thermodynamic cycles provide good examples of human systems where simple and clearly defined modifications can be made to increase efficiency. Twenty-three variations on the Brayton and Rankine cycles are used to understand the relationship between design decisions that maximize a system’s efficient use of energy (measured by thermodynamic first law efficiency) and ecological measures of robustness and structural efficiency. The results reveal that thermodynamic efficiency and ecological pathway efficiency do not always correlate and that while on average modifications to increase energy efficiency reduce the robustness of the system, the engineering understanding of ecological network design presented here can enable decisions that are able to increase both energy efficiency and robustness.

PLOS ONE (2019) “A quantitative engineering study of ecosystem robustness using thermodynamic power cycles as case studies” Panyam, V. and Layton, A.

BiSSL First Author Interdisciplinary Paper Published

Our interdisciplinary paper with Electrical Engineering, first authored by BiSSL grad student Varuneswara Panyam, has been published in Applied Energy. The paper covers our proposed method for using ecosystems to guide the design of power grids towards a more biologically-inspired resilience.

The paper is available for free download here through July 16, 2019.

Technological advances have created a world where humans are highly dependent on an uninterrupted electric power supply, yet extreme weather events and deliberate attacks continue to disrupt power systems. Inherently robust ecological networks present a rich source of robust design guidelines for modern power grids. Analyses of ecosystem networks in literature suggest that this robustness is a consequence of a unique preference for redundant pathways over efficient ones. The structural similarity between these two system-types is exploited here through the application of ecological properties and analysis techniques to long-term power grid design. The level of biological similarity between these two system-types is quantitatively investigated and compared by computing ecological network metrics for a set of synthetic power systems and food webs. The comparison substantiates the use of the ecological robustness metric for optimizing the design of power grid networks. A bio-inspired optimization model is implemented, which restructures the synthetic power systems to mimic ecosystem robustness. The bio-inspired optimal networks are evaluated using N-1, N-2, and N-3 contingency analyses to assess system performance under the loss of 1, 2, and 3 components respectively. The bio-inspired grids all experienced significantly fewer violations in each loss scenario compared to traditional configurations, further supporting the application of the ecological robustness metric for power system robustness. The results provide insights into how ecological robustness can guide the design of power systems for improved infrastructural resilience to better survive disturbances.

“Bio-inspired design for robust power grid networks” by Varuneswara Panyam, Hao Huang, Katherine Davis, Astrid Layton