Temperature-Driven Structural Identification for Bridge Performance Evaluation

Bridges serve as integral components of infrastructure all around the world. Their direct impact to society is substantial, and their reliability is paramount. As such, confidence in the integrity of these structures is important not only for individuals who utilize these structures but also for the bridge owners and engineers who operate and maintain them. In order to develop a comprehensive understanding of the structural behavior, evaluations are conducted to assess the structure’s performance. By utilizing input-output relationships between loads and responses, structural performance evaluations provide an opportunity to assess unique bridge behavior such as complex mechanisms or deterioration. The research presented herein investigates a novel, temperature-driven concept for bridge performance evaluation wherein thermal behavior in response to environmental temperature changes is used to assess the structure. Within this research, two bridges are evaluated using a probabilistic approach of single and multiple model updating within the temperature-driven structural identification process. This technique utilizes Latin Hypercube Sampling as well as Bayesian calibration to identify unknown bridge parameters and evaluate the structural performance. Then, these studies are compiled into a synthesis of temperature-driven evaluations from nineteen bridge studies throughout the world to develop a comprehensive framework and to provide guidance for using thermal behavior for performance evaluations. The intellectual merit from each study illuminates various motivations, methods, successes, and challenges of temperature-driven evaluations. Guidance regarding structure details, monitoring criteria, as well as data and analysis is provided to assist bridge owners, engineers, and researchers who utilize this temperature-driven technique to conduct evaluations. Based on the research presented herein, temperature-driven performance evaluations provide extensive insight, not only to the thermal behavior of the bridge, but the overall structural health

Temperature-Driven Structural Identification for Bridge Performance Evaluation

Bridges serve as integral components of infrastructure all around the world. Their direct impact to society is substantial, and their reliability is paramount. As such, confidence in the integrity of these structures is important not only for individuals who utilize these structures but also for the bridge owners and engineers who operate and maintain them. In order to develop a comprehensive understanding of the structural behavior, evaluations are conducted to assess the structure’s performance. By utilizing input-output relationships between loads and responses, structural performance evaluations provide an opportunity to assess unique bridge behavior such as complex mechanisms or deterioration. The research presented herein investigates a novel, temperature-driven concept for bridge performance evaluation wherein thermal behavior in response to environmental temperature changes is used to assess the structure. Within this research, two bridges are evaluated using a probabilistic approach of single and multiple model updating within the temperature-driven structural identification process. This technique utilizes Latin Hypercube Sampling as well as Bayesian calibration to identify unknown bridge parameters and evaluate the structural performance. Then, these studies are compiled into a synthesis of temperature-driven evaluations from nineteen bridge studies throughout the world to develop a comprehensive framework and to provide guidance for using thermal behavior for performance evaluations. The intellectual merit from each study illuminates various motivations, methods, successes, and challenges of temperature-driven evaluations. Guidance regarding structure details, monitoring criteria, as well as data and analysis is provided to assist bridge owners, engineers, and researchers who utilize this temperature-driven technique to conduct evaluations. Based on the research presented herein, temperature-driven performance evaluations provide extensive insight, not only to the thermal behavior of the bridge, but the overall structural health

The First United States Microgravity Laboratory

The United States Microgravity Laboratory (USML-1) is one part of a science and technology program that will open NASA's next great era of discovery and establish the United States' leadership in space. A key component in the preparation for this new age of exploration, the USML-1 will fly in orbit for extended periods, providing greater opportunities for research in materials science, fluid dynamics, biotechnology, and combustion science. The major components of the USML-1 are the Crystal Growth Furnace, the Surface Tension Driven Convection Experiment (STDCE) Apparatus, and the Drop Physics Module. Other components of USML-1 include Astroculture, Generic Bioprocessing Apparatus, Extended Duration Orbiter Medical Project, Protein Crystal Growth, Space Acceleration Measurement System, Solid Surface Combustion Experiment, Zeolite Crystal Growth and Spacelab Glovebox provided by the European Space Agency

Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts

High-efficient energy harvesting architecture for self-powered thermal-monitoring wireless sensor node based on a single thermoelectric generator

In recent years, research on transducers and system architectures for self-powered devices has gained attention for their direct impact on the Internet of Things in terms of cost, power consumption, and environmental impact. The concept of a wireless sensor node that uses a single thermoelectric generator as a power source and as a temperature gradient sensor in an efficient and controlled manner is investigated. The purpose of the device is to collect temperature gradient data in data centres to enable the application of thermal-aware server load management algorithms. By using a maximum power point tracking algorithm, the operating point of the thermoelectric generator is kept under control while using its power-temperature transfer function to measure the temperature gradient. In this way, a more accurate measurement of the temperature gradient is achieved while harvesting energy with maximum efficiency. The results show the operation of the system through its different phases as well as demonstrate its ability to efficiently harvest energy from a temperature gradient while measuring it. With this system architecture, temperature gradients can be measured with a maximum error of 0.14 ∘ C and an efficiency of over 92% for values above 13 ∘ C and a single transducer.This work was supported by the research Grant PID2019-110142RB-C22 funded by MCIN/ AEI/10.13039/501100011033

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Variation in Salamander Life History and Community Composition Across an Urban Gradient in Atlanta, Georgia, USA

Urbanization threatens to alter stream systems in watersheds in the eastern United States. These highly disturbed systems may result in many local extirpations of sensitive salamander species. One group of organisms that often persists in urban streams is the Eurycea bislineata (Two-lined Salamander) species complex. Many aspects of Two-lined Salamander life history are linked to environmental factors, particularly stream temperature, prey abundance, and stream hydrology. Urbanization threatens to alter these environmental factors, potentially influencing Two-lined Salamander life history. At 14 sites spanning an urban gradient in Atlanta, GA, I investigated the variation in life history and phenology in the Southern Two-lined Salamander, E. cirrigera. I aimed to investigate 1) the anthropogenic and natural factors influencing thermal profiles in urban streams; 2) the environmental drivers of larval period and size; 3) the relationship between clutch size, female size, and degree of urbanization; and 4) changes in plethodontid salamander species richness across an urban gradient, using environmental DNA. I found that 1) drainage basin area was a better predictor of stream temperature than impervious surface cover; 2) cooler August temperatures predicted a longer larval period and smaller larvae; 3) higher impervious surface cover predicted larger larvae and larger adult females; 4) larger females were associated with significantly larger clutches; and 5) plethodontid salamander species richness decreased with increasing impervious surface cover. The results of this research help to assess the ecological implications of urban development by expanding our understanding of the mechanisms underlying variation in E. cirrigera life history and the impacts of urbanization on salamander species richness