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Spatial Patterning and Growth of Naturally Regenerated Eastern White Pine in a Northern Hardwood Silviculture Experiment
Get PDFIn forests dominated by deciduous tree species, coniferous species are often disproportionately important because of their contrasting functional traits. Eastern white pine (Pinus strobus L.), once a widespread emergent canopy species, co-occurs with deciduous hardwoods in the northern Lake States, but is often uncommon in contemporary hardwood stands. To gain insights into the potential utility of hardwood management strategies for simultaneously regenerating white pine, we leveraged a northern hardwood silvicultural experiment with scattered overstory pine. Seven growing seasons post-harvest, we conducted a complete census of white pine regeneration (height ≥ 30 cm) and mapped their locations and the locations of potential seed trees. Pine regeneration was sparse and strongly spatially aggregated, with most clusters falling within potential seed shadows of overstory pines. New recruits were found to have the highest density in a scarified portion of the study area leeward of potential seed trees. Low regeneration densities within treatment units, strong spatial aggregation, and the spatial arrangement of potential seed trees precluded generalizable inferences regarding the utility of specific treatment combinations. Nevertheless, our results underscore the critical importance of residual overstory pines as seed sources and highlight the challenges associated with realizing their potential in managed northern hardwoods
Integrating Recycled Acrylonitrile–Butadiene–Styrene Plastics from Electronic Waste with Carbon Black for Sustainable Asphalt Production
Get PDFAs the global demand for electronic equipment continues to grow, many devices are being replaced more frequently, resulting in a rapid rise in electronic waste (e-waste), now the fastest growing waste stream worldwide. Motivated by this, the objective of this study is to present an environmentally friendly method to recycle acrylonitrile–butadiene–styrene (ABS), one of the most common e-waste plastics, by using it for asphalt production. In contrast to earlier methods of plastic-modified asphalt production involving complex pretreatments or complimentary additives unsuitable for plant-scale use, this study aims to demonstrate a practical, low-cost solution through the use of carbon black. This approach included physically pretreating ABS plastics for size reduction and incorporating waste tire-derived carbon black to promote effective dispersion in asphalt during wet modification. The rheological properties of the e-waste-modified asphalt were subsequently assessed. The test results indicated that recycling ABS plastics with a blending content of 5% alongside 5% carbon black can enhance cold-weather cracking resistance and high-temperature anti-rutting performance of asphalt. The enhancement can be attributed to the proper preparation procedures of ABS plastics and the addition of carbon black, which can further improve the performance by promoting the proper dispersion of plastic particles in asphalt. The outcome of this study indicates that recycling e-waste plastics through asphalt production can lead to more green and sustainable asphalt construction, reduce total construction costs, and most importantly enhance performance
Online citizen science in higher education courses
Get PDFClimate change and biodiversity loss require us to engage the next generation of scientists in addressing global ecological issues. Introducing undergraduate students to citizen science allows them to learn scientific processes and content while contributing to real-world applications. We conducted a systematic review of literature to (1) identify what types of undergraduate courses and institutions use citizen science, (2) list the projects and platforms that have been implemented in online courses in undergraduate education, (3) examine how students participated in the projects through online courses, and (4) summarize learning objectives and reported benefits of student participation. In all, 44 studies about the use of citizen science in undergraduate online courses were found in 25 papers in the published literature. The most common projects consisted of classification of species or natural history (e.g., iNaturalist), which could be done mainly online but with data collection completed at a location available to the student. Citizen science projects were incorporated into multiple course formats (e.g., lecture, lab) and class sizes, and students were most frequently asked to collect and submit data. The most frequently reported learning outcomes included increased student interest/engagement, improved appreciation for the relevance of science to the “real world,” and practice using the scientific process, but rigorous assessment data were lacking in papers. The use of citizen science in online courses and institutions appears to be increasing, and we encourage faculty using these approaches with students to publish on their efforts, providing details about their implementation, assessment, and course context
A Model Intercomparison Study of Aerosol-Cloud-Turbulence Interactions in a Cloud Chamber: 1. Model Results
Get PDFThis study presents the first model intercomparison of aerosol-cloud-turbulence interactions in a controlled cloudy Rayleigh-Bénard Convection chamber environment, utilizing the Pi Chamber at Michigan Technological University. We analyzed simulated cloud chamber-averaged statistics of microphysics and thermodynamics in a warm-phase, cloudy environment under steady-state conditions at varying aerosol injection rates. Simulation results from seven distinct models (DNS, LES, and a 1D turbulence model) were compared. Our findings demonstrate that while all models qualitatively capture observed trends in droplet number concentration, mean radius, and droplet size distributions at both high and low aerosol injection rates, significant quantitative differences were observed. Notably, droplet number concentrations varied by over two orders of magnitude between models for the same injection rates, indicating sensitivities to the model treatments in droplet activation and removal and wall fluxes. Furthermore, inconsistencies in vertical relative humidity profiles and in achieving steady-state liquid water content suggest the need for further investigation into the mechanisms driving these variations. Despite these discrepancies, the models generally reproduced consistent power-law relationships between the microphysical variables. This model intercomparison underscores the importance of controlled cloud chamber experiments for validating and improving cloud microphysical parameterizations. Recommendations for future modeling studies are also highlighted, including constraining wall conditions and processes, investigating droplet/aerosol removal (including sidewall losses), and conducting simplified experiments to isolate specific processes contributing to model divergence and reduce model uncertainties
Hourly Simulated Power Production Data with Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Single-Axis Tracking Systems in the U.S. Eastern Interconnection for Weather Year 2014
No full textUsing 2014 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory’s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be single-axis tracking systems. Sites’ latitudes and longitudes were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with No Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Single-Axis Tracking Systems in the U.S. Eastern Interconnection for Weather Year 2015
No full textUsing 2015 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory\u27s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadat
Digital circular economy for attaining sustainable development goals: Technologies for global sustainability
No full textDigital technology with circular economy concepts is one of the game-changing strategies for sustainable development goals (SDGs). The digital circular economy presents possibilities and threats, which this section discusses. Concerns about data privacy and security, regulatory and economic hurdles, and the need for a shift in culture and behavior are among the most pressing problems. However, there are many chances to be innovative through working with others, forming partnerships, and expanding into new areas. Stakeholders may make strides towards a more sustainable and resilient economy by responding to these threats and capitalizing on these possibilities. To better understand and implement digital circular practices, future research should focus on creating standardized impact metrics, developing cutting-edge technologies, establishing supportive policy frameworks, gaining insights into consumer behavior, creating innovative business models, conducting sector-specific studies, considering social equity, collaborating globally, and ensuring long-term sustainability
Hourly Simulated Power Production Data with Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2013
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2013. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2013_PV_existing_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2016
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2016. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2016_PV_existing_site_metadata.csv file for individual site metadata
Remote Sightline Inspection at Highway-Rail Grade Crossings Using LiDAR Data and Geospatial Analysis
No full textIncidents at highway-rail grade crossings (HRGCs) result in fatalities, injuries, and property damage. Monitoring over 212,000 HRGCs across the United States (US) is challenging due to reliance on on-site inspections. Obstructed sightlines increase risks by limiting drivers\u27 ability to detect approaching trains. Despite previous studies on behavioral and safety concerns, quantitative analysis of sightlines remains underexplored. This study addresses this gap by applying remote sensing techniques to quantify sightline visibility. We developed a method to measure available sightlines within sight distance triangles and rank HRGCs based on available sightlines using geospatial analysis, incorporating US Geological Survey Light Detection and Ranging (LiDAR) data and US Department of Transportation crossing inventory reports. Our findings show that sightline issues are influenced by traffic control devices, environmental conditions, and geometric factors. This research demonstrates the potential of LiDAR and geospatial analysis as rapid, cost-effective tools for identifying visibility problems at HRGCs