LEED-NC version 2.2 rating system applications of common structural materials

Maher, J.E., Kramer, K.W.. LEED-NC version 2.2 rating system applications of common structural materials. 2007. Sustainable Construction Materials and Technologies, Taylor and Francis Group.Comprehensive understanding of building materials has been the basis of structural engineering. The rising environmental concern is making sustainability a crucial issue in our society. In creating a sustainable built environment, the architect usually takes the lead role with the mechanical engineer having the key responsibility for energy and water savings. Only recently have structural engineers and civil engineers begun to see the real potential of their contributions. This paper contains information pertaining to the four most common structural materials: reinforced concrete, reinforced masonry, steel, and timber. For each material, the sustainability of the material as defined by the LEED-NC Version 2.2 rating system is discussed. Information is provided on how to attain LEED points for a specific material. Whether the LEED-NC Version 2.2 rating system accurately portrays sustainability of common structural materials or needs further development is discussed in the conclusion. A comparison is provided of the four common structural materials in relation to the rating system

Slip modulus of cold-formed steel members sheathed with wood structural panels

Maher, J. E., & Kramer, K. W. (2007). LEED-NC version 2.2 rating system applications of common structural materials. Paper presented at the Sustainable Construction Materials and Technologies - International Conference on Sustainable Construction Materials and Technologies, 549-562.Cold-formed steel framing sheathed with wood structural panels is a common method of construction for wall, roof and floor systems in cold-formed steel structures. Since wood structural panels are attached with screws at relatively close spacing, a certain amount of composite behavior will be present. The benefit of composite behavior is not currently being taken advantage of in the design of these structural systems. While composite effects are present, they are not yet being accounted for in design due to a lack of statistical data. To determine the amount of composite action taking place in these systems, the slip modulus between steel and wood is required. The slip modulus reflects the amount of shear force able to be transferred through the screw connection, to either member of the composite system. This paper presents the results of a study conducted to determine values of the slip modulus for varying thicknesses of cold-formed steel and plywood sheathing. Shear tests were conducted and the slip moduli were determined based on ISO 6891 and ASTM D1761. Compared with data from a previous preliminary study performed by others, the slip modulus values determined from these tests were deemed reasonable. The determination of the slip modulus will lead to the ability to calculate a composite factor. Determination of a composite factor will allow cold-formed steel wood structural panel construction to become more economical due to the available increase in bending strength

An empirical examination of echo chambers in US climate policy networks

Diverse methods have been applied to understand why science continues to be debated within the climate policy domain. A number of studies have presented the notion of the ‘echo chamber’ to model and explain information flows across an array of social settings, finding disproportionate connections among ideologically similar political communicators. This paper builds on these findings to provide a more formal operationalization of the components of echo chambers. We then empirically test their utility using survey data collected from the community of political elites engaged in the contentious issue of climate politics in the United States. Our survey period coincides with the most active and contentious period in the history of US climate policy, when legislation regulating carbon dioxide emissions had passed through the House of Representatives and was being considered in the Senate. We use exponential random graph (ERG) modelling to demonstrate that both the homogeneity of information (the echo) and multi-path information transmission (the chamber) play significant roles in policy communication. We demonstrate that the intersection of these components creates echo chambers in the climate policy network. These results lead to some important conclusions about climate politics, as well as the relationship between science communication and policymaking at the elite level more generally.US National Science FoundationNational Socio-Environmental Synthesis Center (SESYNC

Shifting echo chambers in US climate policy networks

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data are available from the Climate Constituencies study at http://drfisher.umd.edu/CCP_REVISED.html.Although substantial attention has focused on efforts by the new Administration to block environmental policies, climate politics have been contentious in the US since well before the election of Donald Trump. In this paper, we extend previous work on empirical examinations of echo chambers in US climate politics using new data collected on the federal climate policy network in summer 2016. We test for the similarity and differences at two points in time in homophily and echo chambers using Exponential Random Graph Models (ERGM) to compare new findings from 2016 to previous work on data from 2010. We show that echo chambers continue to play a significant role in the network of information exchange among policy elites working on the issue of climate change. In contrast to previous findings where echo chambers centered on a binding international commitment to emission reductions, we find that the pre-existing echo chambers have almost completely disappeared and new structures have formed around one of the main components of the Obama Administration’s national climate policy: the Clean Power Plan. These results provide empirical evidence that science communication and policymaking at the elite level shift in relation to the policy instruments under consideration.MacArthur Foundatio

Shifting Echo Chambers in US Climate Policy Networks

Although substantial attention has focused on efforts by the new Administration to block environmental policies, climate politics have been contentious in the US since well before the election of Donald Trump. In this paper, we extend previous work on empirical examinations of echo chambers in US climate politics using new data collected on the federal climate policy network in summer 2016. We test for the similarity and differences at two points in time in homophily and echo chambers using Exponential Random Graph Models (ERGM) to compare new findings from 2016 to previous work on data from 2010. We show that echo chambers continue to play a significant role in the network of information exchange among policy elites working on the issue of climate change. In contrast to previous findings where echo chambers centered on a binding international commitment to emission reductions, we find that the pre-existing echo chambers have almost completely disappeared and new structures have formed around one of the main components of the Obama Administration’s national climate policy: the Clean Power Plan. These results provide empirical evidence that science communication and policymaking at the elite level shift in relation to the policy instruments under consideration