Time-Dependent Reliability of Concrete Bridges Considering Climate Change and Overload

Author(s):  
Wei Luo ◽  
Bo Pang ◽  
Chengcheng Shi ◽  
Yinshan Liu ◽  
Yuanfeng Wang
2021 ◽  
Author(s):  
Seung Hye Lee ◽  
Lorie Hamelin

The transition to bioeconomy and low-fossil carbon economy (LFCE) requires long-term investments, whose environmental and economic performance will be affected by various future conditions, such as the raw material availability and the type of energy or fertilizers used (and replaced). Considering multiple background futures instead of one single projection in building time-dependent inventories for assessing LFCE solutions would greatly enhance the robustness of the decision support provided by environmental assessments such as Life Cycle Assessments (LCA). Here, we reviewed, through automatized and manual text-mining, six internationally well-recognized global environmental scenario studies and one intelligence report. The aim was to uncover the key variables and cause-effect relationships at play in these scenario studies. Through constructing causal loop diagrams for each reviewed study, we identified the variables with the greatest number of causal connections, the “cause” and “effect” variables, and revealed the most reported cause-effect relationships across all studies. Our main findings are: (1) the top 5 causal variables are mitigation policies, technological progress, consumers’ awareness, economic growth and education level, while (2) the top 5 affected variables are climate change, materials use, food security, natural ecosystems, and social justice. Amongst the top 10 causal and affected variables (3), 68 connected pairs were identified with no disagreement in their causal relationship directions. The three most reported pairs were (4) mitigation policy → climate change, healthy and sustainable diet → land use, and population → materials use (each reported in four studies). Finally, (5) we highlighted that all the reviewed studies are based on the decision-making logic of maximizing utility. We concluded that identifying these key cause-effect variables and relationships was essential for building time-dependent inventories in LCA, and that these may be a more useful input than the direct use of any of the scenario reviewed herein.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Mark Denny

AbstractBody temperature affects plants’ and animals’ performance, but these effects are complicated by thermal variation through time within an individual and variation through space among individuals in a population. This review and synthesis describes how the effects of thermal variation—in both time and space—can be estimated by applying a simple, nonlinear averaging scheme. The method is first applied to the temporal variation experienced by an individual, providing an estimate of the individual’s average performance. The method is then applied to the scale-dependent thermal variation among individuals, which is modelled as a 1/f-noise phenomenon. For an individual, thermal variation reduces average performance, lowers the temperature of maximum performance (Topt) and contracts the range of viable temperatures. Thermal variation among individuals similarly reduces performance and lowers Topt, but increases the viable range of average temperatures. These results must be viewed with caution, however, because they do not take into account the time-dependent interaction between body temperature and physiological plasticity. Quantifying these interactions is perhaps the largest challenge for ecological and conservation physiologists as they attempt to predict the effects of climate change.


Sign in / Sign up

Export Citation Format

Share Document