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A Soft Robotic Gripper With Neutrally Buoyant Jamming Pads for Gentle Yet Secure Grasping of Underwater Objects
No full textDelicate grasping of complex diverse objects is a challenging task for underwater vehicles, such as remotely operated vehicles (ROVs). In this article, a novel controllably compliant soft robotic underwater gripper is presented, which uses two neutrally buoyant particle jamming pads to safely and securely grasp arbitrarily shaped objects, including fragile and/or massive targets. Antagonistic low-friction rolling diaphragm hydraulic cylinders are used to control the compliance of the jaw closure to passively limit the total force applied during the approach. The antagonistic hydraulic cylinders also compensate for the volume reduction of the pads during the jamming process while still enabling rigid grasp during manipulation. Soft finger-like fiber-reinforced actuators are used to maintain the shape of pads without introducing rigid elements. Force limitation is demonstrated by the ability to pick up fragile objects without breakage and to surround soft targets without excessive deformation of the object. We present the overall design, experimental setup, and in-water testing using a compact ROV-based hydraulic drive system. The resulting system has demonstrated capability for grasping a diverse range of objects that vary widely in terms of weight, size, and geometry, largely enabled by the hybrid design of soft grippers guiding jamming pads into optimal configurations
Thermal trait variation may buffer Southern Ocean phytoplankton from anthropogenic warming
No full textDespite the potential of standing genetic variation to rescue communities and shape future adaptation to climate change, high levels of uncertainty are associated with intraspecific trait variation in marine phytoplankton. Recent model intercomparisons have pointed to an urgent need to reduce uncertainty in the projected responses of marine ecosystems to climate change, including Southern Ocean (SO) surface waters, which are among the most rapidly warming habitats on Earth. Because SO phytoplankton growth responses to warming sea surface temperature (SST) are poorly constrained, we developed a high-throughput growth assay to simultaneously examine inter- and intra-specific thermal trait variation in a group of 43 taxonomically diverse and biogeochemically important SO phytoplankton called diatoms. We found significant differential growth performance among species across thermal traits, including optimum and maximum tolerated growth temperatures. Within species, coefficients of variation ranged from 3% to 48% among strains for those same key thermal traits. Using SO SST projections for 2100, we predicted biogeographic ranges that differed by up to 97% between the least and most tolerant strains for each species, illustrating the role that strain-specific differences in temperature response can play in shaping predictions of future phytoplankton biogeography. Our findings revealed the presence and scale of thermal trait variation in SO phytoplankton and suggest these communities may already harbour the thermal trait diversity required to withstand projected 21st-century SST change in the SO even under severe climate forcing scenarios
Indigenous Women’s Knowledge: Prairies, Power, and Plants
No full textAlthough many people think that bison and men hunting bison were central to the story of Indigenous peoples on the northern Great Plains, Rosalyn LaPier argues that plants and women harvesting plants were essential to Indigenous peoples livelihoods, their ecological understanding, and religious practice. She will explore the world of Amskapi Piikani or Blackfeet women and those who identified with womanhood from the 19th century to the present on the prairies of North America.
In fall 2022, LaPier joined the faculty of the Department of History at the University of Illinois, Urbana-Champaign; she also holds an appointment as a Research Associate at the National Museum of Natural History, Smithsonian Institution. Her work is within Indigenous communities to revitalize Indigenous and traditional ecological knowledge (TEK), to address environmental justice & the climate crisis, and to strengthen public policy for Indigenous languages. Dr. LaPier is an enrolled member of the Blackfeet Tribe of Montana and Métis. She is one of eight Indigenous professors nationally in an Environmental Studies/Sciences/Sustainability department and the first and only Blackfeet tribal member to be in a tenure-track position and to receive tenure from the University of Montana.
LaPier also co-founded Saokio Heritage, a community-based organization which is led by Indigenous women and serves as a platform to amplify Indigenous women activists and writers. She is currently working on her third book, tentatively titled, Plants that Purify: Essays on the Ecology of Blackfeet Womanhood.
LaPier’s book, Invisible Reality: Storytellers, Storytakers, and the Supernatural World of the Blackfeet won the 2018 John C. Ewers Book Award for best book on ethnohistory of North America and the 2018 Donald Fixico Award for best book on American Indian and Canadian First Nations History
Length, width, shape regularity, and chain structure: time series analysis of phytoplankton morphology from imagery
Get PDFFunctional traits are increasingly used to assess changes in phytoplankton community structure and to link individual characteristics to ecosystem functioning. However, they are usually inferred from taxonomic identification or manually measured for each organism, both time consuming approaches. Instead, we focus on high throughput imaging to describe the main temporal variations of morphological changes of phytoplankton in Narragansett Bay, a coastal time-series station. We analyzed a 2-yr dataset of morphological features automatically extracted from continuous imaging of individual phytoplankton images (~ 105 million images collected by an Imaging FlowCytobot). We identified synthetic morphological traits using multivariate analysis and revealed that morphological variations were mainly due to changes in length, width, shape regularity, and chain structure. Morphological changes were especially important in winter with successive peaks of larger cells with increasing complexity and chains more clearly connected. Small nanophytoplankton were present year-round and constituted the base of the community, especially apparent during the transitions between diatom blooms. High inter-annual variability was also observed. On a weekly timescale, increases in light were associated with more clearly connected chains while more complex shapes occurred at lower nitrogen concentrations. On an hourly timescale, temperature was the determinant variable constraining cell morphology, with a general negative influence on length and a positive one on width, shape regularity, and chain structure. These first insights into the phytoplankton morphology of Narragansett Bay highlight the possible morphological traits driving the phytoplankton succession in response to light, temperature, and nutrient changes
Fracture response of wollastonite fiber-reinforced cementitious composites: Evaluation using micro-indentation and finite element simulation
No full textThe paper presents indentation studies on wollastonite fiber incorporated cementitious systems. The acicular nature of the fibers is poised to delay the coalescence of micro-cracks in such systems thus leading to tougher building materials. Towards that end, load-penetration depth results from the indentation studies are employed to ascertain elastic and fracture properties of wollastonite-incorporated cementitious composites. While up to 10% mass-based cement-replacement by wollastonite results in comparable elastic moduli as compared to conventional binders, the fracture toughness increases by as much as 33%. In order to gain insights into the toughening mechanisms brought about by the fine fibers, a microstructure-guided numerical simulation strategy is adopted towards effective fracture performance prediction. The performance enhancement of the wollastonite systems is corroborated by the finite element-based simulations carried out on the virtual microstructures that accurately capture the heterogeneity of such systems. Besides fracture performance enhancement, the wollastonite-incorporated cementitious systems also contribute towards development of sustainable cement replacing compositions. Moreover, the micromechanical predictive tool developed in this study facilitate efficient means to tune the materials structure for desired performance
Language Mapping using tEEG and EEG Data with Convolutional Neural Networks
No full textTripolar electroencephalography (tEEG) has been found to have significantly better signal-to-noise ratio, spatial resolution, mutual information, and high-frequencies compared to EEG. This paper analyzes the tEEG signals acquired simultaneously with the EEG signals and compares their ability to map language to left and right hemispheres using convolutional neural networks (CNNs). The results show that while the time-domain features of tEEG and EEG signals lead to comparable functional mapping, the frequency domain features are significantly different. The left and right hemisphere classification performances using tEEG are equivalent in time and frequency domains. However, frequency domain classification for EEG results in less accuracy. Clinical Relevance - This technique could quickly, and noninvasively, guide clinicians about language dominance when preparing for resective surgery
Automated Visual Inspection System
Get PDFTeam 8 was tasked with working collaboratively with Miniature Casting Corporation with the goal of providing assistance to solve a complication within the company’s quality control process. The problem at hand involved solving an issue where manual visual inspection is inefficient for time and costs, by halting not only the quality process, but also the production process. Miniature Casting Corporation currently has a stockpile of parts in their factory that must be inspected. The Rejector Inspector automated visual inspection system will allow them to turn their assets into usable product. The final design consisted of the Keyence Vision Sensor attached to a hand-built structure used for testing various different variables and scenarios to determine the optimal procedure for accurate scanning of zinc cast parts
Design of Collimator for Neutron Radiography
Get PDFThe purpose of this capstone project is to build a functional, working neutron radiography imaging collimator, for use at the Rhode Island Nuclear Science Center (RINSC). Neutron imaging is a non-destructive imaging method that reveals the internal structure of samples by subjecting them to a neutron beam. The collimator is the device which focuses a beam of particles through a hollow cylindrical shell, connected to the beam port of the nuclear reactor. After careful consideration, the team decided to use a parallel collimator design for the project as it was the best collimator that optimized the desired specifications. The team’s design of the collimator will consist of aluminum shells as well as a boron carbide powder and concrete, alternatively being packed into annular discs and spread throughout the collimator, which will provide shielding from radiation, as well as eliminate attenuation and reduce gamma ray exposure. The team had to work with certain constraints which changed the potential design of the collimator. The first one was the room size that was given by RINSC, as well as the weight and mobility of the collimator, and another was the budget parameters assigned by Los Alamos National Laboratory (LANL). Lastly, the team is to ensure that the design meets both NRC and ALARA guidelines. Throughout the design process, the team’s countless hours of research, as well as meeting with sponsors allowed for a design which meets all of the specifications requested by the sponsors, and professor
Underwater Nuclear Inspection Drone
Get PDFTeam 10, the Rhody ROVs, was tasked by the Los Alamos National Laboratory (LANL) and the Rhode Island Nuclear Science Center (RINSC) with designing an underwater remotely operated vehicle (ROV) for use in the inspection of fuel elements at the research nuclear reactor located at the University of Rhode Island (URI) Bay Campus in Narragansett. The ROV needed to be radiation resistant, provide a stable camera feed, and be able to move around to inspect multiple fuel elements. The ROV needed to be operable by the staff at RINSC. The team outlined the design specifications and problem definition then performed a long design process to generate solutions to the problem definition and refine a singular design from the best concepts. This process consisted of research into existing solutions and patents as well as the brainstorming of design concepts. The team then ran a series of experiments to prove the viability of the design and created a functional prototype of the design which was then tested and iterated upon. The results of the experiments showed that the team’s design is a viable solution to the task and is competitive with other solutions on the market