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SkimShark
Get PDFConventionally, a pool\u27s surface is cleaned by two main methods; by stationary skimmers built into the walls of pools, and by hand. Stationary, built in skimmers are connected into the pool’s plumbing system and use the water recycling and cleaning system built into the pool. As water flows to these outlets on the side of the pool, the water flows through a one-way flap and into skimmer baskets. The other method, by hand, involves someone using a skimmer on a long pole to scoop out leaves and other debris by reaching the pole out and under the debris and lifting the skimmer up to grab it off of the water’s surface. Skim Team Six was given the assignment to create an autonomous device that can do the job of these two methods for a 30 foot by 50 foot pool in under two hours without any human assistance.
The design requirements in this report are to be met by creating and using an arduino controlled vessel that will be able to autonomously navigate the pool\u27s entire surface and collect debris near the water\u27s surface with no human interaction after set up.
This report presents the design specifications that were created for this project and the research that went into those specifications. As well as the original 120 design concepts that were created to meet those specifications. From those 120 concepts the team narrowed them down to their top 3 designs and chose the one that they would move forward with by doing a QFD and analyzing the different designs for what they thought would work best. Since then the team chose to move forward with a pontoon style skimmer with a single collection basket in between the two hulls. A proof of concept was then done showing how this skimmer design will be their best option.
In the following 5 months after the proof of concept, a full size model of the SkimShark equipped with a collection basket, underwater propulsion, and autonomous movement was successfully built, tested, and optimized. The SkimShark is expected to be a successful product
My Deep Sea, My Backyard: a pilot study to build capacity for global deep-ocean exploration and research
Get PDFThe deep ocean is the largest ecosystem on the planet, constituting greater than 90% of all habitable space. Over three-quarters of countries globally have deep ocean within their Exclusive Economic Zones. While maintaining deep-ocean function is key to ensuring planetary health, deficiencies in knowledge and governance, as well as inequitable global capacity, challenge our ability to safeguard the resilience of this vast realm, leaving the fate of the deep ocean in the hands of a few. Historically, deep-ocean scientific exploration and research have been the purview of a limited number of nations, resulting in most of humankind not knowing the deep ocean within their national jurisdiction or beyond. In this article, we highlight the inequities and need for increased deep-ocean knowledge generation, and discuss experiences in piloting an innovative project \u27My Deep Sea, My Backyard\u27 toward this goal. Recognizing that many deep-ocean endeavours take place in countries without deep-ocean access, this project aimed to reduce dependency on external expertise and promote local efforts in two small island developing states, Trinidad and Tobago and Kiribati, to explore their deep-sea backyards using comparatively low-cost technology while building lasting in-country capacity. We share lessons learned so future efforts can bring us closer to achieving this goal. This article is part of the theme issue \u27Nurturing resilient marine ecosystems\u27
Humanities as/and/of Crises
No full textBeginning with a brief historical survey (picking up the story with the Renaissance), Colapietro’s purpose is to highlight the ways in which the humanities, from their origin to the present, have been implicated in cultural crises. They are ineluctably the sites of such crises. Optimally, they are resources for clarifying the significance of the crises at the center of any culture. If the humanities are not in intense crises, culture and education are in deepest trouble. Though this might be offered as a glib or facile reply to the state of affairs, it can also be framed in a responsible and orienting manner. W. B. Gallie’s concept of “an essentially contested concept” provides an important resource for framing the humanities as/and/of crises in this manner.
Colapietro’s exploration of the humanities is part of both his historical work (the recovery of American pragmatists such as Peirce, James, and Dewey for crises of American democracy) and one of his systematic concerns (articulating an understanding of history which provides a via media, an approach offering an alternative to self-defeating forms of historical “relativism” and the untenable position of absolutism or objectivism). Colapietro’s presentation is central to his interests and commitments, as these animate his work as a scholar
Wind Turbulence over Misaligned Surface Waves and Air–Sea Momentum Flux. Part II: Waves in Oblique Wind
No full textThe coupled dynamics of turbulent airflow and a spectrum of waves are known to modify air–sea momentum and scalar fluxes. Waves traveling at oblique angles to the wind are common in the open ocean, and their effects may be especially relevant when constraining fluxes in storm and tropical cyclone conditions. In this study, we employ largeeddy simulation for airflow over steep, strongly forced waves following and opposing oblique wind to elucidate its impacts on the wind speed magnitude and direction, drag coefficient, and wave growth/decay rate. We find that oblique wind maintains a signature of airflow separation while introducing a cross-wave component strongly modified by the waves. The directions of mean wind speed and mean wind shear vary significantly with height and are misaligned from the wind stress direction, particularly toward the surface. As the oblique angle increases, the wave form drag remains positive, but the wave impact on the equivalent surface roughness (drag coefficient) rapidly decreases and becomes negative at large angles. Our findings have significant implications for how the sea-state-dependent drag coefficient is parameterized in forecast models. Our results also suggest that wind speed and wind stress measurements performed on a wave-following platform can be strongly contaminated by the platform motion if the instrument is inside the wave boundary layer of dominant waves
Evidence for transitional and mildly alkalic eruptions during Hawai\u27i\u27s dominantly tholeiitic shield-building stage: Insights from the Kulanaokuaiki Tephra (≥1.0 ka) at Kīlauea Volcano, HI
Get PDFVitric clasts from a marker horizon in the Kulanaokuaiki Tephra, deposited on the summit and flanks of Kīlauea Volcano, HI, during a prolonged period of explosive eruptions and low magma supply \u3e1.0 ka, show unusual enrichments in alkalis relative to silica and in incompatible elements, in contrast with the volcano\u27s dominantly tholeiitic shield-building lavas. The clasts are transitional basalts, with compositions near the tholeiitic-alkalic boundary (Macdonald and Katsura, 1964). Nearly uniform in composition across ∼200 km2, the clasts are the most proximal to the summit among rare occurrences of transitional and mildly alkalic shield-stage eruptions at Kīlauea. In contrast with the volcano\u27s effusive shield-building style, stratigraphic evidence suggests the clasts were deposited in one of Kīlauea\u27s most vigorous explosive eruptions in the past 2.5 ka—an episode punctuated by high fountaining along with an ∼12 km-tall ash plume. The tephra\u27s composition is consistent with those of five unusual shield-stage Kīlauea lavas. All contain 0.30 wt% P2O5. The transitional Kulanaokuaiki clasts also display elevated abundances and ratios of incompatible trace elements (e.g., ∼19 ppm La, La/Yb ∼ 8.6). Compositionally, these early shield-stage clasts and lavas resemble those erupted at the end of shield building at older Hawaiian volcanoes, attributed to lower degrees of partial mantle melting. Chemical constraints and extrinsic circumstances suggest that similar episodes of transitional and mildly alkalic volcanism will likely recur throughout shield building
Seabed morphology and bed shear stress predict temperate reef habitats in a high energy marine region
Get PDFHigh energy marine regions host ecologically important habitats like temperate reefs, but are less anthropogenically developed and understudied compared to lower energy waters. In the marine environment direct habitat observation is limited to small spatial scales, and high energy waters present additional logistical challenges and constraints. Semi-automated predictive habitat mapping is a cost-effective tool to map benthic habitats across large extents, but performance is context specific. High resolution environmental data used for predictive mapping are often limited to bathymetry, acoustic backscatter and their derivatives. However, hydrodynamic energy at the seabed is a critical habitat structuring factor and likely an important, yet rarely incorporated, predictor of habitat composition and spatial patterning. Here, we used a machine learning classification approach to map temperate reef substrate and biogenic reef habitat in a tidal energy development area, incorporating bathymetric derivatives at multiple scales and simulated tidally induced seabed shear stress. We mapped reef substrate (four classes: sediment (not reef), stony reef (low resemblance), stony reef (medium – high resemblance) and bedrock reef) with overall balanced accuracy of 71.7%. Our model to predict potential biogenic Sabellaria spinulosa reef performed less well with an overall balanced accuracy of 63.4%. Despite low performance metrics for the target class of potential reef in this model, it still provided insight into the importance of different environmental variables for mapping S. spinulosa biogenic reef habitat. Tidally induced mean bed shear stress was one of the most important predictor variables for both reef substrate and biogenic reef models, with ruggedness calculated at multiple scales from 3 m to 140 m also important for the reef substrate model. We identified previously unresolved relationships between temperate reef spatial distribution, hydrodynamic energy and seabed three-dimensional structure in energetic waters. Our findings contribute to a better understanding of the spatial ecology of high energy marine ecosystems and will inform evidence-based decision making for sustainable development, particularly within the growing tidal energy sector
Assisted self-assessment to optimize the OPIc test experience
No full textThe ACTFL Oral Proficiency Interview—computer (OPIc) employs a self-assessment instrument to determine the nature of the speaking prompts to which the test taker will respond and, thus the difficulty of the test. Grounded in research demonstrating varying levels of accuracy in self-assessment among language learners, this study examines the accuracy of test takers\u27 autonomous selection of appropriate OPIc forms and investigates strategies for maximizing level-appropriate form selection. Chinese, German, and Spanish language learners (n = 101) completed three different self-assessments before taking the OPIc. Self-assessment results across the three tools were then compared to the OPIc ratings ultimately achieved by the learners. Although accuracy in the selection of level-appropriate OPIc forms was generally quite high, success rates were higher with a global 10-point self-assessment instrument. These findings suggest that test takers may benefit from the assistance of a global 10-point scale in the OPIc form selection process
The fundamental links between climate change and marine plastic pollution
Get PDFPlastic pollution and climate change have commonly been treated as two separate issues and sometimes are even seen as competing. Here we present an alternative view that these two issues are fundamentally linked. Primarily, we explore how plastic contributes to greenhouse gas (GHG) emissions from the beginning to the end of its life cycle. Secondly, we show that more extreme weather and floods associated with climate change, will exacerbate the spread of plastic in the natural environment. Finally, both issues occur throughout the marine environment, and we show that ecosystems and species can be particularly vulnerable to both, such as coral reefs that face disease spread through plastic pollution and climate-driven increased global bleaching events. A Web of Science search showed climate change and plastic pollution studies in the ocean are often siloed, with only 0.4% of the articles examining both stressors simultaneously. We also identified a lack of regional and industry-specific life cycle analysis data for comparisons in relative GHG contributions by materials and products. Overall, we suggest that rather than debate over the relative importance of climate change or marine plastic pollution, a more productive course would be to determine the linking factors between the two and identify solutions to combat both crises