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Reference Governor Design In The Presence Of Uncertain Polynomial Constraints, Rick Schieni, Chengwei Zhao, Michael Malisoff, Laurent Burlion Jan 2023

Reference Governor Design In The Presence Of Uncertain Polynomial Constraints, Rick Schieni, Chengwei Zhao, Michael Malisoff, Laurent Burlion

Faculty Publications

Reference governors are add-on schemes that are used to modify trajectories to prevent controlled dynamical systems from violating input or state constraints, and so are playing an increasingly important role in aerospace, robotic, and other applications. Here we present a novel reference governor design for systems whose polynomial constraints depend on unknown bounded parameters. This is a significant departure from earlier treatments of reference governors, where the constraints were linear or known, because here we transfer the uncertainties into the constraints instead of having them in the closed loop dynamics, which greatly simplifies the task of determining future evolution of …

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Almost Fixed Time Observers For Parameters And For State Variables Of Nonlinear Systems, Frederic Mazenc, Michael Malisoff, Laurent Burlion Jan 2023

Almost Fixed Time Observers For Parameters And For State Variables Of Nonlinear Systems, Frederic Mazenc, Michael Malisoff, Laurent Burlion

Faculty Publications

We provide new finite-time and fast-converging observers for continuous-time nonlinear systems that contain unknown constant parameters and measurement delays. When the dynamics are affine in the unmeasured state, we obtain fixed time observers that identify unknown states and unknown model parameters. When the dynamics contain a nonlinearity that depends on the unmeasured state, we instead obtain asymptotic convergence of our observers, whose rate of convergence converges to infinity as the growth rate of this nonlinearity converges to zero, so in this case we call the observers almost fixed time observers. Our examples illustrate how our assumptions can be easily checked.

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Uniqueness Of Entire Solutions To Quasilinear Equations Of P-Laplace Type, Nguyen Cong Phuc, Igor E. Verbitsky Jan 2023

Uniqueness Of Entire Solutions To Quasilinear Equations Of P-Laplace Type, Nguyen Cong Phuc, Igor E. Verbitsky

Faculty Publications

We prove the uniqueness property for a class of entire solutions to the equation (Formula presented) where σ is a nonnegative locally finite measure in Rn, absolutely continuous with respect to the p-capacity, and div A(x, ∇u) is the A-Laplace operator, under standard growth and monotonicity assumptions of order p (1 < p < ∞) on A(x, ξ) (x, ξ ∈ Rn); the model case A(x, ξ) = ξ|ξ|p−2 corresponds to the p-Laplace operator ∆p on Rn. Our main results establish uniqueness of solutions to a similar problem,(Formula presented) in the sub-natural growth case 0 < q < p − 1, where µ, σ are nonnegative locally finite measures in Rn, absolutely continuous with respect to the …

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Seepage-Induced Pore Pressure Variations Beneath An Earthen Levee Measured With A Novel Seismic Tool, Daniel Locci-Lopez, Juan M. Lorenzo Jan 2023

Seepage-Induced Pore Pressure Variations Beneath An Earthen Levee Measured With A Novel Seismic Tool, Daniel Locci-Lopez, Juan M. Lorenzo

Faculty Publications

Shear-wave seismic reflection velocity-versus-depth models can complement our understanding of seepage pore pressure variations beneath earthen levees at locations between geotechnical sites. The seasonal variations of water level in the Mississippi River create pore pressure changes in the adjacent hydraulically connected aquifer on the protected side of artificial levees. Time-lapse shear-wave velocity analysis or repetition of seismic acquisition over an area is a non-invasive method that can detect seasonal pore pressure variations in shallow (< 40 m) aquifers. The seismic reflection patterns during the seasonal pore pressure variations of the river show a distinctive change in the velocity semblance analysis, which is translated as a change in the average stress carried by the grain-to-grain contact, or simply the effective pressure. The seismic data show a greater variation of up to +140/−40 m/s or +700/−150 kPa in the confined aquifer zone, compared with the leaky confined aquifer zone of up to +46/−48 m/s or +140/−80 kPa. These relative effective pressure characteristics allow us to distinguish between confined and leaky aquifers and can be an optional approach for pressure prediction in floodplains along levees without the need to drill borings in the area to measure piezometric data.

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Climate And Atlantic Sea-Level Recorded In Southwestern Spain From 6.3 To 5.2 Ma. Inferences On The Messinian Crisis In The Mediterranean, Jean Pierre Suc, Séverine Fauquette, Sophie Warny, Gonzalo Jiménez-Moreno, Damien Do Couto Jan 2023

Climate And Atlantic Sea-Level Recorded In Southwestern Spain From 6.3 To 5.2 Ma. Inferences On The Messinian Crisis In The Mediterranean, Jean Pierre Suc, Séverine Fauquette, Sophie Warny, Gonzalo Jiménez-Moreno, Damien Do Couto

Faculty Publications

The Mio-Pliocene succession of Andalusia on the Atlantic coast (Guadalquivir Basin) is known as one of the former stratotype candidate for the Andalusian Stage, proposed during the seventies as the last stage of the Miocene. Its type section is located in Carmona, east of Seville. Our investigation includes the drilling of three cored boreholes, which provide bio- and magnetic-stratigraphic data in complement to pre-existing industrial information, and a high-resolution palynological analysis (pollen grains, spores and dinoflagellate cysts). The pollen flora and its climatic quantification provide the mean to correlate the section to the oxygen isotope curve from the Montemayor-1 borehole, …

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Lsu General Catalog 2023-2024, Louisiana State University And Agricultural And Mechanical College Jan 2023

Lsu General Catalog 2023-2024, Louisiana State University And Agricultural And Mechanical College

LSU General Catalog

The LSU General Catalog describes all undergraduate and graduate departments and programs with degree requirements and courses offered for each one. The LSU General Catalog includes information on registration and financial aid as well as academic services offered to all students.

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The Link Between Marine Thermal Discharges And Nemopilema Nomurai Blooms Around Nuclear Power Plants, Jiawei Wu, Jie Kong, Edward A. Laws, Xin Liu, Changyun Wang, Jixin Chen, Mianrun Chen, Qingzhen Yao, Yantao Wang, Yu Zhen, Chaolun Li, Bangqin Huang Jan 2023

The Link Between Marine Thermal Discharges And Nemopilema Nomurai Blooms Around Nuclear Power Plants, Jiawei Wu, Jie Kong, Edward A. Laws, Xin Liu, Changyun Wang, Jixin Chen, Mianrun Chen, Qingzhen Yao, Yantao Wang, Yu Zhen, Chaolun Li, Bangqin Huang

Faculty Publications

Recent research has shown that jellyfish blooms occur more frequently near nuclear power plants (NPPs), and a relationship between thermal discharges from the NPPs and the blooms has been hypothesized. There is, however, no direct evidence that links the thermal discharges with jellyfish blooms. In this study, we conducted 3 cruises (pre-bloom, bloom, and post-bloom) during July to September 2017 in the area surrounding the largest NPP in northern China. The water temperature near the cooling water outfall rose by 2 °C. Although we found no significant impact on phytoplankton abundance or community composition near the outfall, a broader analysis …

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Phylogenomics Of Trans-Andean Tetras Of The Genus Hyphessobrycon Durbin 1908 (Stethaprioninae: Characidae) And Colonization Patterns Of Middle America, Diego J. Elías, Caleb D. Mcmahan, Fernando Alda, Carlos García-Alzate, Pamela B. Hart, Prosanta Chakrabarty Jan 2023

Phylogenomics Of Trans-Andean Tetras Of The Genus Hyphessobrycon Durbin 1908 (Stethaprioninae: Characidae) And Colonization Patterns Of Middle America, Diego J. Elías, Caleb D. Mcmahan, Fernando Alda, Carlos García-Alzate, Pamela B. Hart, Prosanta Chakrabarty

Faculty Publications

Hyphessobrycon is one of the most species rich and widely distributed genera in the family Characidae, with more than 160 species ranging from Veracruz, Mexico to Mar Chiquita Lagoon in Buenos Aires, Argentina. The majority of Hyphessobrycon diversity shows a cis- Andean distribution; only nine species are trans-Andean including H. compressus (Meek 1908). It is well established that Hyphessobrycon is not monophyletic but it has been suggested that natural groups can be identified within the larger Hyphessobrycon species group. In this study, we tested the monophyly of trans-Andean species of Hyphessobrycon and investigated the placement of H. compressus. We inferred …

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A Finite Element Method For A Two-Dimensional Pucci Equation, Susanne C. Brenner, Li Yeng Sung, Zhiyu Tan Jan 2023

A Finite Element Method For A Two-Dimensional Pucci Equation, Susanne C. Brenner, Li Yeng Sung, Zhiyu Tan

Faculty Publications

A nonlinear least-squares finite element method for strong solutions of the Dirichlet boundary value problem of a two-dimensional Pucci equation on convex polygonal domains is investigated in this paper. We obtain a priori and a posteriori error estimates and present corroborating numerical results, where the discrete nonsmooth and nonlinear optimization problems are solved by an active set method and an alternating direction method with multipliers.

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Key Parameters Linking Cyber-Physical Trust Anchors With Embedded Internet Of Things Systems, Michele Maasberg, Leslie G. Butler, Ian Taylor Jan 2023

Key Parameters Linking Cyber-Physical Trust Anchors With Embedded Internet Of Things Systems, Michele Maasberg, Leslie G. Butler, Ian Taylor

Faculty Publications

Integration of the Internet of Things (IoT) in the automotive industry has brought benefits as well as security challenges. Significant benefits include enhanced passenger safety and more comprehensive vehicle performance diagnostics. However, current onboard and remote vehicle diagnostics do not include the ability to detect counterfeit parts. A method is needed to verify authentic parts along the automotive supply chain from manufacture through installation and to coordinate part authentication with a secure database. In this study, we develop an architecture for anti-counterfeiting in automotive supply chains. The core of the architecture consists of a cyber-physical trust anchor and authentication mechanisms …

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The Oncolytic Herpes Simplex Virus Type-1 (Hsv-1) Vaccine Strain Vc2 Causes Intratumor Infiltration Of Functionally Active T Cells And Inhibition Of Tumor Metastasis And Pro-Tumor Genes Vegf And Pdl1 Expression In The 4t1/Balb/C Mouse Model Of Stage Four Breast Cancer, Rafiq Nabi, Farhana Musarrat, Jose Cesar Jose, Ingeborg M. Langohr, Vladimir N. Chouljenko, Konstantin G. Kousoulas Jan 2023

The Oncolytic Herpes Simplex Virus Type-1 (Hsv-1) Vaccine Strain Vc2 Causes Intratumor Infiltration Of Functionally Active T Cells And Inhibition Of Tumor Metastasis And Pro-Tumor Genes Vegf And Pdl1 Expression In The 4t1/Balb/C Mouse Model Of Stage Four Breast Cancer, Rafiq Nabi, Farhana Musarrat, Jose Cesar Jose, Ingeborg M. Langohr, Vladimir N. Chouljenko, Konstantin G. Kousoulas

Faculty Publications

Introduction: Oncolytic viruses (OVs) provide new modalities for cancer therapy either alone or in combination with synergistic immunotherapies and/or chemotherapeutics. Engineered Herpes Simplex Virus Type-1 (HSV-1) has shown strong promise for the treatment of various cancers in experimental animal models as well as in human patients, with some virus strains licensed to treat human melanoma and gliomas. In the present study we evaluated the efficacy of mutant HSV-1 (VC2) in a late stage, highly metastatic 4T1 murine syngeneic. Method: VC2 was constructed VC2 using double red recombination technology. For in-vivo efficacy we utilized a late stage 4T1 syngeneic and immunocompetent …

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Novel Liquor-Based Hot Sauce: Physicochemical Attributes, Volatile Compounds, Sensory Evaluation, Consumer Perception, Emotions, And Purchase Intent, Ricardo S. Aleman, Jhunior A. Marcía, Ismael Montero-Fernández, Joan King, Shirin Kazemzadeh Pournaki, Roberta Targino Hoskin, Marvin Moncada Jan 2023

Novel Liquor-Based Hot Sauce: Physicochemical Attributes, Volatile Compounds, Sensory Evaluation, Consumer Perception, Emotions, And Purchase Intent, Ricardo S. Aleman, Jhunior A. Marcía, Ismael Montero-Fernández, Joan King, Shirin Kazemzadeh Pournaki, Roberta Targino Hoskin, Marvin Moncada

Faculty Publications

Hot sauces are popular peppery condiments used to add flavor and sensory excitement to gastronomical preparations. While hot sauce occupies a retail category well over a century old, a novel production method using liquor as the base preservative rather than traditional vinegar is now commercially available, and its uniqueness begs study. Hot sauces produced with tequila, rum, vodka, and bourbon were compared to traditional vinegar-based hot sauces concerning physicochemical properties, volatile compounds, microbiological quality, sensory scores, emotions, and purchase intent (PI). Under accelerated conditions, pH, titratable acidity (TA), water activity (Aw), viscosity, and color were analyzed weekly for 20 weeks, …

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Part I — Introduction: Social Physics And The Vespace Project, Jeffrey M. Leichman, Ben Samuel Jan 2023

Part I — Introduction: Social Physics And The Vespace Project, Jeffrey M. Leichman, Ben Samuel

Faculty Publications

This article introduces the VESPACE project, an international, multi-disciplinary digital humanities initiative to build a computer-mediated playable simulation—a video game—of the eighteenth-century Paris Fair theatre. As part of this project, a weeklong postgraduate workshop was convened by the authors in May 2020 to develop protocols and procedures for coding literary and historical data for the Ensemble social physics engine that will govern behaviour of non-player characters (NPCs) in the interactive model. This article lays out the history and theory of social physics, the potential impacts of this project on historiographic practice, and the methodology and outcomes of the workshop week. …

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The Rise Of Native Lordships At Pashash, A.D. 200–600, North Highlands Of Ancash, Peru, George F. Lau, Milton Luján Dávila, Jacob L. Bongers, David Chicoine Jan 2023

The Rise Of Native Lordships At Pashash, A.D. 200–600, North Highlands Of Ancash, Peru, George F. Lau, Milton Luján Dávila, Jacob L. Bongers, David Chicoine

Faculty Publications

This article examines the rise of native, segmentary lordships in the highlands of north-central Peru. It reports on new excavations and mapping at the seat of a prehispanic polity, Pashash (Recuay culture), a large hilltop center that developed after the collapse of Chavín civilization. Fieldwork revealed monumental constructions and two special activity contexts radiocarbon-dated to ca. a.d. 200–400: an offering area in a large palatial compound and a room-complex with chambers closed off and sealed with feasting refuse. Multiple lines of evidence help reconstruct a regional picture for the establishment of wealthy local elites. Cultural innovations explicitly link new leaders …

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Administering Freedom: The State Of Emancipation After The Freedmen’S Bureau, Dale Kretz, Jeffery Hardin Hobson Jan 2023

Administering Freedom: The State Of Emancipation After The Freedmen’S Bureau, Dale Kretz, Jeffery Hardin Hobson

Civil War Book Review

Dr. Dale Kretz and editor Jeffery Hardin Hobson discuss Kretz's book, Administering Freedom: The State of Emancipation after the Freedmen's Bureau.

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Civil Wars And Reconstructions In The Americas: The United States, Mexico, And Argentina, 1860-1880., Andre M. Fleche Jan 2023

Civil Wars And Reconstructions In The Americas: The United States, Mexico, And Argentina, 1860-1880., Andre M. Fleche

Civil War Book Review

Reviewer Andre M. Fleche writes that E. C. Rothera's Civil Wars and Reconstructions in the Americas: The United States, Mexico, and Argentina, 1860-1880 is "one of the most thorough & sustained analyses yet written of the mid-19th c. relations between the US and Latin America."

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Natural Dyeing With Madder: Exploring Traditional Techniques And Color Characteristics, Guangguo Tian, Rongrong Cui, Chuanlan Liu, Xiaorui Hu Jan 2023

Natural Dyeing With Madder: Exploring Traditional Techniques And Color Characteristics, Guangguo Tian, Rongrong Cui, Chuanlan Liu, Xiaorui Hu

Faculty Publications

The color red has a significant presence in cultures around the world. The organic dye madder, derived from plants, has been used throughout human civilization and remains an important natural dye. The research reviews five traditional madder dyeing techniques from China, Europe, Turkey, and Japan. The techniques are applied to cotton, linen, silk, and wool fabrics, and their similarities and differences are compared and analyzed. Additionally, the environmental sustainability, resource conservation, and process efficiency of these dyeing techniques are also evaluated in this article. The chromatic value of dyed textile color was tested by means of an American Hunterlab spectrophotometer, …

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Planetary Protection: An International Concern And Responsibility, Athena Coustenis, Niklas Hedman, Peter T. Doran, Omar Al Shehhi, Eleonora Ammannito, Masaki Fujimoto, Olivier Grasset, Frank Groen, Alexander G. Hayes, Vyacheslav Ilyin, K. Praveen Kumar, Caroline Emmanuelle Morisset, Christian Mustin, Karen Olsson-Francis, Jing Peng, Olga Prieto-Ballesteros, Francois Raulin, Petra Rettberg, Silvio Sinibaldi, Yohey Suzuki, Kanyan Xu, Maxim Zaitsev Jan 2023

Planetary Protection: An International Concern And Responsibility, Athena Coustenis, Niklas Hedman, Peter T. Doran, Omar Al Shehhi, Eleonora Ammannito, Masaki Fujimoto, Olivier Grasset, Frank Groen, Alexander G. Hayes, Vyacheslav Ilyin, K. Praveen Kumar, Caroline Emmanuelle Morisset, Christian Mustin, Karen Olsson-Francis, Jing Peng, Olga Prieto-Ballesteros, Francois Raulin, Petra Rettberg, Silvio Sinibaldi, Yohey Suzuki, Kanyan Xu, Maxim Zaitsev

Faculty Publications

Planetary protection is a set of measures agreed upon at an international level to ensure the protection of scientific investigation during space exploration. As space becomes more accessible with traditional and new actors launching complex and innovative projects that involve robotics (including sample return) and human exploration, we have the responsibility to protect the pristine environments that we explore and our own biosphere. In this sense, the Committee on Space Research (COSPAR) provides the international standard for planetary protection as well as a forum for international consultation. COSPAR has formulated a Planetary Protection Policy with associated requirements for responsible space …

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Creating Continents: Archean Cratons Tell The Story, Carol D. Frost, Paul A. Mueller, David W. Mogk, B. Ronald Frost, Darrell J. Henry Jan 2023

Creating Continents: Archean Cratons Tell The Story, Carol D. Frost, Paul A. Mueller, David W. Mogk, B. Ronald Frost, Darrell J. Henry

Faculty Publications

The record of the first two billion years of Earth’s history (the Archean) is notoriously incomplete, yet crust of this age is present on every continent. Here we examine the Archean record of the Wyoming craton in the northern Rocky Mountains, USA, which is both well-exposed and readily accessible. We identify three stages of Archean continental crust formation that are also recorded in other cratons. The youngest stage is characterized by a variety of Neoarchean rock assemblages that are indistinguishable from those produced by modern plate-tectonic processes. The middle stage is typified by the trondhjemite-tonalite-granodiorite (TTG) association, which involved partial …

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Monitoring Of Wave, Current, And Sediment Dynamics Along The Chincoteague Living Shoreline, Virginia, Hongqing Wang, Qin Chen, Nan Wang, William D. Capurso, Lukasz M. Niemoczynski, Ling Zhu, Gregg A. Snedden, Kevin S. Holcomb, Bowdoin W. Lusk, Carol A. Wilson, Sean R. Cornell Jan 2023

Monitoring Of Wave, Current, And Sediment Dynamics Along The Chincoteague Living Shoreline, Virginia, Hongqing Wang, Qin Chen, Nan Wang, William D. Capurso, Lukasz M. Niemoczynski, Ling Zhu, Gregg A. Snedden, Kevin S. Holcomb, Bowdoin W. Lusk, Carol A. Wilson, Sean R. Cornell

Faculty Publications

Nature-based features, also called living shorelines, are increasingly applied in coastal protection and restoration. However, the processes and mechanisms (feedbacks and interactions) of wave attenuation, current velocity change, and sediment deposition and erosion along the living shoreline remain unclear, thus limiting the adaptive management of living shoreline restoration projects for coastal shoreline resilience under future storm conditions. In this study, wave, current, and sediment dynamics along the Little Toms Cove living shoreline, Chincoteague National Wildlife Refuge, Virginia, a low wave energy environment, were investigated during a 2-month winter period in 2019 to examine the effects of living shoreline structures on …

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Learning Infused Quantum-Classical Distributed Optimization Technique For Power Generation Scheduling, Reza Mahroo, Amin Kargarian Jan 2023

Learning Infused Quantum-Classical Distributed Optimization Technique For Power Generation Scheduling, Reza Mahroo, Amin Kargarian

Faculty Publications

The advent of quantum computing can potentially revolutionize how complex problems are solved. This article proposes a two-loop quantum-classical solution algorithm for generation scheduling by infusing quantum computing, machine learning, and distributed optimization. The aim is to facilitate employing noisy near-term quantum machines with a limited number of qubits to solve practical power system optimization problems, such as generation scheduling. The outer loop is a three-block quantum alternating direction method of multipliers (QADMM) algorithm that decomposes the generation scheduling problem into three subproblems, including one quadratically unconstrained binary optimization (QUBO) and two non-QUBOs. The inner loop is a trainable quantum …

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Interfacial Activity And Surface Pka Of Perfluoroalkyl Carboxylic Acids (Pfcas), Ruchi Patel, Luis E. Saab, Philip J. Brahana, Kalliat T. Valsaraj, Bhuvnesh Bharti Jan 2023

Interfacial Activity And Surface Pka Of Perfluoroalkyl Carboxylic Acids (Pfcas), Ruchi Patel, Luis E. Saab, Philip J. Brahana, Kalliat T. Valsaraj, Bhuvnesh Bharti

Faculty Publications

Perfluoroalkyl carboxylic acids (PFCAs) are widely used synthetic chemicals that are known for their exceptional stability and interfacial activity. Despite their industrial and environmental significance, discrepancies exist in the reported pKa values for PFCAs, often spanning three to four units. These disparities stem from an incomplete understanding of how pH influences the ionized state of PFCA molecules in the bulk solution and at the air-water interface. Using pH titration and surface tension measurements, we show that the pKa values of the PFCAs adsorbed at the air-water interface differ from the bulk. Below the equivalence point, the undissociated and dissociated forms …

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Multifunctional Composite With Hybrid Carbon Fiber And Carbonaceous Coconut Particle Reinforcement, Foster Feni, Maryam Jahan, Rong Zhao, Guoqiang Li, Guang Lin Zhao, Patrick F. Mensah Jan 2023

Multifunctional Composite With Hybrid Carbon Fiber And Carbonaceous Coconut Particle Reinforcement, Foster Feni, Maryam Jahan, Rong Zhao, Guoqiang Li, Guang Lin Zhao, Patrick F. Mensah

Faculty Publications

The utilization of multifunctional composite materials presents significant advantages in terms of system efficiency, cost-effectiveness, and miniaturization, making them highly valuable for a wide range of industrial applications. One approach to harness the multifunctionality of carbon fiber reinforced polymer (CFRP) is to integrate it with a secondary material to form a hybrid composite. In our previous research, we explored the use of carbonaceous material derived from coconut shells as a sustainable alternative to inorganic fillers, aiming to enhance the out-of-plane mechanical performance of CFRP. In this study, our focus is to investigate the influence of carbonized coconut shell particles on …

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Editorial: Application Of Periodic Structure Theory With Finite Element Approach, Chitaranjan Pany, Guoqiang Li Jan 2023

Editorial: Application Of Periodic Structure Theory With Finite Element Approach, Chitaranjan Pany, Guoqiang Li

Faculty Publications

No abstract provided.

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Toward The Development Of Plasticity Theories For Application To Small-Scale Metal Structures, Bin Zhang, K. L. Nielsen, J. W. Hutchinson, W. J. Meng Jan 2023

Toward The Development Of Plasticity Theories For Application To Small-Scale Metal Structures, Bin Zhang, K. L. Nielsen, J. W. Hutchinson, W. J. Meng

Faculty Publications

Experiments are performed on micron-scale single-crystal prototypical structural elements experiencing combined torsion and bending to gather data on their load-carrying capacity in the range of size and strain relevant to micron-scale structures for which little data are available. The observed strengthening dependence on size for the structural elements is in general accord with trends inferred from prior tests such as indentation and pure torsion. In addition, the experiments systematically reveal the strengthening size-dependence of structural elements whose surface has been passivated by a very thin Cr coating, an effect shown to have substantial strengthening potential. A state-of-the-art strain gradient plasticity …

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Study On Soft Robotic Pinniped Locomotion, Dimuthu D.K. Arachchige, Tanmay Varshney, Umer Huzaifa, Iyad Kanj, Thrishantha Nanayakkara, Yue Chen, Hunter B. Gilbert, Isuru S. Godage Jan 2023

Study On Soft Robotic Pinniped Locomotion, Dimuthu D.K. Arachchige, Tanmay Varshney, Umer Huzaifa, Iyad Kanj, Thrishantha Nanayakkara, Yue Chen, Hunter B. Gilbert, Isuru S. Godage

Faculty Publications

Legged locomotion is a highly promising but under-researched subfield within the field of soft robotics. The compliant limbs of soft-limbed robots offer numerous benefits, including the ability to regulate impacts, tolerate falls, and navigate through tight spaces. These robots have the potential to be used for various applications, such as search and rescue, inspection, surveillance, and more. The state-of-the-art still faces many challenges, including limited degrees of freedom, a lack of diversity in gait trajectories, insufficient limb dexterity, and limited payload capabilities. To address these challenges, we develop a modular soft-limbed robot that can mimic the locomotion of pinnipeds. By …

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Dynamic Modeling And Validation Of Soft Robotic Snake Locomotion, Dimuthu D.K. Arachchige, Sanjaya Mallikarachchi, Iyad Kanj, Dulanjana M. Perera, Yue Chen, Hunter B. Gilbert, Isuru S. Godage Jan 2023

Dynamic Modeling And Validation Of Soft Robotic Snake Locomotion, Dimuthu D.K. Arachchige, Sanjaya Mallikarachchi, Iyad Kanj, Dulanjana M. Perera, Yue Chen, Hunter B. Gilbert, Isuru S. Godage

Faculty Publications

Soft robotic snakes made of compliant materials can continuously deform their bodies and, therefore, mimic the biological snakes' flexible and agile locomotion gaits better than their rigid-bodied counterparts. Without wheel support, to date, soft robotic snakes are limited to emulating planar locomotion gaits, which are derived via kinematic modeling and tested on robotic prototypes. Given that the snake locomotion results from the reaction forces due to the distributed contact between their skin and the ground, it is essential to investigate the locomotion gaits through efficient dynamic models capable of accommodating distributed contact forces. We present a complete spatial dynamic model …

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The Potential Benefit Of Pseudo High Thermal Conductivity For Laser Powder Bed Fusion Additive Manufacturing, Huan Ding, Selami Emanet, Yehong Chen, Shengmin Guo Jan 2023

The Potential Benefit Of Pseudo High Thermal Conductivity For Laser Powder Bed Fusion Additive Manufacturing, Huan Ding, Selami Emanet, Yehong Chen, Shengmin Guo

Faculty Publications

This study examined the impact of transient pseudo high thermal conductivity to the fabrication of crack-free parts with Laser Powder-Bed-Fusion (L-PBF) based additive manufacturing (AM) method. Thermal diffusivity and thermal conductivity of L-PBF samples made by mixtures of IN939 alloy and Si powders were investigated. At temperatures above 800°C, the as-fabricated Si-doped IN939 was observed to exhibit an exceptionally high thermal conductivity, which can be attributed to the occurrence of endothermic reactions. This pseudo high thermal conductivity can effectively minimize the thermal stress and offers a potential solution to produce crack-free L-PBF parts for nonweldable alloys.

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Optimizing Pier Design To Mitigate Scour: A Comprehensive Review And Large Eddy Simulation Study, A. M. Aly, F. Khaled Jan 2023

Optimizing Pier Design To Mitigate Scour: A Comprehensive Review And Large Eddy Simulation Study, A. M. Aly, F. Khaled

Faculty Publications

Scour-induced sediment erosion poses a significant threat to the safety and longevity of infrastructure, including bridges, wind turbines, elevated buildings, and coastal infrastructure. Despite the well-known destructive consequences of scour, accurate models that capture the complexity of its dynamics remain elusive, impeding the development of effective countermeasures. We provide a comprehensive review of existing literature on scour dynamics and examine the fluid dynamics and bed shear stress surrounding bridge piers. We propose CFD (Computational Fluid Dynamics) simulations with LES (Large-Eddy Simulation). The current paper demonstrate that LES is a more effective technique than RANS (Reynolds averaged Navier-Stokes) for investigating bridge …

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Show Us The Data: Global Covid-19 Wastewater Monitoring Efforts, Equity, And Gaps, Colleen C. Naughton, Fernando A. Roman, Ana Grace F. Alvarado, Arianna Q. Tariqi, Matthew A. Deeming, Krystin F. Kadonsky, Kyle Bibby, Aaron Bivins, Gertjan Medema, Warish Ahmed, Panagis Katsivelis, Vajra Allan, Ryan Sinclair, Joan B. Rose Jan 2023

Show Us The Data: Global Covid-19 Wastewater Monitoring Efforts, Equity, And Gaps, Colleen C. Naughton, Fernando A. Roman, Ana Grace F. Alvarado, Arianna Q. Tariqi, Matthew A. Deeming, Krystin F. Kadonsky, Kyle Bibby, Aaron Bivins, Gertjan Medema, Warish Ahmed, Panagis Katsivelis, Vajra Allan, Ryan Sinclair, Joan B. Rose

Faculty Publications

A year since the declaration of the global coronavirus disease 2019 (COVID-19) pandemic, there were over 110 million cases and 2.5 million deaths. Learning from methods to track community spread of other viruses such as poliovirus, environmental virologists and those in the wastewater-based epidemiology (WBE) field quickly adapted their existing methods to detect SARS-CoV-2 RNA in wastewater. Unlike COVID-19 case and mortality data, there was not a global dashboard to track wastewater monitoring of SARS-CoV-2 RNA worldwide. This study provides a 1-year review of the “COVIDPoops19” global dashboard of universities, sites, and countries monitoring SARS-CoV-2 RNA in wastewater. Methods to …

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