Digital Commons Network^™

Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are mechanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable parasitic motions due to the planar fabrication constraint. This work introduces a type of lamina emergent torsion (LET) joint that reduces parasitic motions of lamina emergent mechanisms (LEMs), and presents equations for modeling parasitic motion of LET joints. The membrane joint also makes possible one-way joints that can ensure origami-based mechanisms emerge from their flat state (a change point) into the desired …

Design Of Regular 1d, 2d, And 3d Linkage-Based Tessellations, Alden D. Yellowhorse, Nathan Brown, Larry L. Howell

Faculty Publications

Linkage origami is one effective approach for addressing stiffness and accommodating panels of finite size in origami models and tessellations. However, successfully implementing linkage origami in tessellations can be challenging. In this work, multiple theorems are presented that provide criteria for designing origami units or cells that can be assembled into arbitrarily large tessellations. The application of these theorems is demonstrated through examples of tessellations in two and three dimensions.

Nsf/Ieee-Tcpp Curriculum On Parallel And Distributed Computing For Undergraduates - Version Ii - Big Data, Energy, And Distributed Computing, Sushil Prasad, Charles Weems, Alan Sussman, Anshul Gupta, Trilce Estrada, Ramachandran Vaidyanathan, Sheikh Ghafoor, Krishna Kant, Craig Stunkel

Faculty Publications

This special session will report on the updated NSF/IEEE-TCPP Curriculum on Parallel and Distributed Computing released in Nov 2020 by the Center for Parallel and Distributed Computing Curriculum Development and Educational Resources (CDER). The purpose of the special session is to obtain SIGCSE community feedback on this curriculum in a highly interactive manner employing the hybrid modality and supported by a full-time CDER booth for the duration of SIGCSE. In this era of big data, cloud, and multi- and many-core systems, it is essential that the computer science (CS) and computer engineering (CE) graduates have basic skills in parallel and …

Analysis Of The Rigid Motion Of A Conical Developable Mechanism, Mckell Woodland, Michelle Hsiung, Erin L. Matheson, C Alex Safsten, Jacob Greenwood, Denise M. Halverson, Larry L. Howell

Faculty Publications

We demonstrate analytically that it is possible to construct a developable mechanism on a cone that has rigid motion. We solve for the paths of rigid motion and analyze the properties of this motion. In particular, we provide an analytical method for predicting the behavior of the mechanism with respect to the conical surface. Moreover, we observe that the conical developable mechanisms specified in this paper have motion paths that necessarily contain bifurcation points which lead to an unbounded array of motion paths in the parameterization plane.

Load-Displacement Characterization In Three Degrees Of Freedom For General Let Arrays, Nathan A. Pehrson, Pietro Bilancia, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent torsion (LET) joints for use in origami-based applications enables folding of panels. Placing LET joints in series and parallel (formulating LET arrays) opens the design space to provide for tunable stiffness characteristics in other directions while maintaining the ability to fold. Analytical equations characterizing the elastic load-displacement for general serial-parallel formulations of LET arrays for three degrees of freedom are presented: rotation about the desired axis, in-plane rotation, and extension/compression. These equations enable the design of LET arrays for a variety of applications, including origami-based mechanisms. These general equations are verified using finite element analysis and, to show …

Limits Of Extramobile And Intramobile Motion Of Cylindrical Developable Mechanisms, Jared Butler, Larry L. Howell, Spencer P. Magleby, Jacob Greenwood

Faculty Publications

Mechanisms that can both deploy and provide motions to perform desired tasks offer a multifunctional advantage over traditional mechanisms. Developable mechanisms (DMs) are devices capable of conforming to a predetermined developable surface and deploying from that surface to achieve specific motions. This paper builds on the previously identified behaviors of extramobility and intramobility by introducing the terminology of extramobile and intramobile motion, which define the motion of developable mechanisms while interior and exterior to a developable surface. The limits of motion are identified using defined conditions. It is shown that the more difficult of these conditions to kinematically predict may …

Autonomous Single-Molecule Manipulation Based On Reinforcement Learning, Bernhard Ramsauer, Grant J. Simpson, Johannes J. Cartus, Andreas Jeindl, Victor García-López, James M. Tour, Leonhard Grill, Oliver T. Hofmann

Faculty Publications

Building nanostructures one-by-one requires precise control of single molecules over many manipulation steps. The ideal scenario for machine learning algorithms is complex, repetitive, and time-consuming. Here, we show a reinforcement learning algorithm that learns how to control a single dipolar molecule in the electric field of a scanning tunneling microscope. Using about 2250 iterations to train, the algorithm learned to manipulate the molecule toward specific positions on the surface. Simultaneously, it generates physical insights into the movement as well as orientation of the molecule, based on the position where the electric field is applied relative to the molecule. This reveals …

Attochemistry Regulation Of Charge Migration, Aderonke S. Folorunso, François Mauger, Kyle A. Hamer, Denawakage D. Jayasinghe, Imam S. Wahyutama, Justin R. Ragains, Robert R. Jones, Louis F. Dimauro, Mette B. Gaarde, Kenneth J. Schafer, Kenneth Lopata

Faculty Publications

Charge migration (CM) is a coherent attosecond process that involves the movement of localized holes across a molecule. To determine the relationship between a molecule's structure and the CM dynamics it exhibits, we perform systematic studies of para-functionalized bromobenzene molecules (X-C6H4-R) using real-time time-dependent density functional theory. We initiate valence-electron dynamics by emulating rapid strong-field ionization leading to a localized hole on the bromine atom. The resulting CM, which takes on the order of 1 fs, occurs via an X localized → C6H4delocalized → R localized mechanism. Interestingly, the hole contrast on the acceptor functional group increases with increasing electron-donating …

Are Denisons In A Political Bubble, Miles Williams, Paul Djupe

Faculty Publications

No abstract provided.

Altogether Now! Early Introduction Of Case-Based Learning For Success In Clinical Chemistry, Cristy E. Moss

Faculty Publications

•Differentiate between active & passive learning. •Identify ways early integration of case-based learning is beneficial for the medical laboratory student. •Summarize current methods for Integration of case-based activities into routine lecture / discussion sessions with students.

Zero Torque Compliant Mechanisms Employing Pre-Buckled Beams, Pietro Bilancia, Samuel Porter Smith, Giovanni Berselli, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The concept of a statically balanced mechanism with a single rotational degree of freedom is presented. The proposed device achieves static balancing by combining positive stiff- ness elements and negative stiffness elements within a nuclear domain. Two designs are discussed. The first is composed of an Archimedean spiral and two pinned-pinned pre-buckled beams. The overall mechanism is modeled via an analytical approach and the element dimensions are optimized. The optimal configuration is then tested through finite element analysis (FEA). A second approach replaces the spiral beam with elastic custom-shaped spline beams. An FEA optimization is performed to determine the shape …

Conceptualizing Stable States In Origami-Based Devices Using An Energy Visualization Approach, Jacob Greenwood, Larry L. Howell, Alex Avila, Spencer P. Magleby

Faculty Publications

In many origami-based applications, a device needs to be maintained in one or more fold states. The origami stability integration method (OSIM) presented in this paper pro- vides an approach for graphically combining various techniques to achieve stability. Existing stability techniques are also categorized into four groups based on whether they are intrinsic or extrinsic to the origami pattern and whether they exhibit gradual or non-gradual energy storage behaviors. These categorizations can help designers select appropriate techniques for their applications. The paper also contains de- sign considerations and resources for achieving stability. Finally, two case studies are presented that use …

Bipolar Membrane Electrodialysis For Sustainable Utilization Of Inorganic Salts From The Reverse Osmosis Concentration Of Real Landfill Leachate, Hao-Ran Yang, Chi-Qian Zhang, Bing Li, Jia-Cheng Yang, Yu-Ming Zheng, Mohammad Younas, Zhi-Hua Zheng

Faculty Publications

Developing an effective resource utilization method for landfill leachate reverse osmosis concentrate (LLRC) remains a challenge because of the high concentrations of inorganic salts and refractory organic compounds. This study applied a bipolar membrane electrodialysis (BMED) to separate inorganic salts from real LLRC while simultaneously reclaiming inorganic acids and bases. The performance of BMED was affected by operating parameters, such as operating voltage, membrane surface flow velocity, and initial acid-base concentration. With optimized operating parameters, the reclaimed acid-base concentrations, desalination rate, and current efficiency were higher with less energy consumption. Ultimately, 0.41 mol/L acids and 0.40 mol/L bases were reclaimed …

Affective Depression Mediates Ptsd To Suicide In A Sample Of Treatment-Seeking First Responders, James Whitworth, Jeanine Galusha, Jose Carbajal, Warren Ponder, Donna Schuman

Faculty Publications

Objective: The aim of this study was to examine the associations of comorbid

posttraumatic stress disorder (PTSD), affective or somatic depression, and

suicide among first responders (FRs). Method: We used baseline data from

FRs (N = 232) who sought services at a nonprofit mental health agency specializing

in treating trauma exposed FRs. We conducted two PROCESS simple

mediation models with PTSD as the predictor, affective depression and somatic

depression as the mediators, and suicidality as the dependent variable.

Results: Affective depression significantly mediated the relationship between

PTSD and suicidality, whereas somatic depression did not. The direct effect …

Temporal Variability In Soil Organic Matter Accretion Rates In Coastal Deltaic Wetlands Under Changing Depositional Environments, Yadav Sapkota, Kehui Xu, Kanchan Maiti, Patrick Inglett, John R. White

Faculty Publications

The Mississippi River Deltaic Plain experiences high relative sea level rise, limited sediment supply, and high marsh edge erosion, leading to the substantial coastal wetland and stored soil organic matter (SOM) loss. The objective of this study was to understand the SOM accumulation rates over the past 1000 years related to the changes in the depositional environment in these highly eroding coastal wetlands. Soil cores (2 m) were collected from four sites in Barataria Basin, LA and analyzed for proportion of organic and mineral matter, total C, N, P, particle size, and stable isotopic composition (δ¹³C and δ …

What Are The Most Effective Proxies In Identifying Storm-Surge Deposits In Paleotempestology? A Quantitative Evaluation From The Sand-Limited, Peat-Dominated Environment Of The Florida Coastal Everglades, Qiang Yao, Kam Biu Liu, Zhenqing Zhang, Erika Rodrigues, Marcelo Cohen, Kanchan Maiti, Yang Yang

Faculty Publications

Although many studies have attempted to reconstruct millennial-scale hurricane patterns using various proxy-based methods, it is still unclear what the most effective proxies are to identify storm surge deposits in different environmental settings. This study quantitatively compares the application of grain-size, loss-on-ignition, stable isotopes, X-ray fluorescence, and palynological proxies in paleotempestology from an organic-rich environment in the Florida Everglades. The nonparametric tests indicate that only 9 among the 27 parameters (mean diameter, %water, %organic, %carbonate, Ca, Sr, Ca/Ti, Cl/Br, and marine microfossils) exhibited significant differences between storm-surge and in situ deposits. The principal component analysis shows that five marine indicators …

The Effects Of Hurricane Harvey On Texas Coastal-Zone Chemistry, Piers Chapman, Steven F. Dimarco, Anthony H. Knap, Antonietta Quigg, Nan D. Walker

Faculty Publications

Hurricane Harvey deposited over 90×109gm3 of rainwater over central Texas, USA, during late August/early September 2017. During four cruises (June, August, September and November 2017) we observed changes in hydrography and nutrient and oxygen concentrations in Texas coastal waters. Despite intense terrestrial runoff, nutrient supply to the coastal ocean was transient, with little phytoplankton growth observed and no hypoxia. Observations suggest this was probably related to the retention of nutrients in the coastal bays and rapid uptake by phytoplankton of nutrients washed out of the bays, as well as dilution by the sheer volume of rainwater and the lack of …

Functional Seascapes: Understanding The Consequences Of Hypoxia And Spatial Patterning In Pelagic Ecosystems, Stephen B. Brandt, Sarah E. Kolesar, Cassandra N. Glaspie, Arnaud Laurent, Cynthia E. Sellinger, James J. Pierson, Michael R. Roman, William C. Boicourt

Faculty Publications

No abstract provided.

Stratification Breakdown By Fall Cold Front Winds Over The Louisiana Shelf In The Northern Gulf Of Mexico: A Numerical Experiment, Mohammad Nabi Allahdadi, Chunyan Li, Nazanin Chaichitehrani

Faculty Publications

Cold fronts are meteorological phenomena that impact the northern Gulf of Mexico, mostly between the fall and spring seasons. On average, they pass the region every 3–7 days, with a duration ranging between 24 and 74 h. In the present study, a high-resolution FVCOM model with an unstructured mesh was used to simulate the effect of the fall cold front winds on water column mixing over the Louisiana shelf, which is often stratified in the summer, leading to hypoxia. Numerical experiments were conducted for October 2009, a period with five consecutive cold front events. Winds from an offshore station forced …

Multi-Agent Optimal Control For Central Chiller Plants Using Reinforcement Learning And Game Theory, Shunian Qiu, Zhenhai Li, Zhihong Pang, Zhengwei Li, Yinying Tao

Faculty Publications

To conserve building energy, optimal operation of a building’s energy systems, especially heating, ventilation and air-conditioning (HVAC) systems, is important. This study focuses on the optimization of the central chiller plant, which accounts for a large portion of the HVAC system’s energy consumption. Classic optimal control methods for central chiller plants are mostly based on system performance models which takes much effort and cost to establish. In addition, inevitable model error could cause control risk to the applied system. To mitigate the model dependency of HVAC optimal control, reinforcement learning (RL) algorithms have been drawing attention in the HVAC control …

Solving The Valuation Challenge: The Ultra Method For Taxing Extreme Wealth, David Gamage, Brian Galle, Darien Shanske

Faculty Publications

Recent reporting based on leaked tax returns of the ultra-rich confirms what experts have long suspected: for the wealthiest Americans, paying taxes is mostly optional. Some of the country's richest have reported annual incomes that would be modest for a school teacher, even as the share of wealth held by the top .1% is at its highest in nearly a century.

Experts have long understood that one problem sits at the root cause of many of the tax system's failures to reach the very rich: valuation. Because it is difficult to appraise complex or unique assets, modern tax systems instead …

Recovery Of Aconitic Acid From Sweet Sorghum Plant Extract Using A Solvent Mixture, And Its Potential Use As A Nematicide, K. Thomas Klasson, Yunci Qi, Gillian O. Bruni, Tristan T. Watson, Bretlyn T. Pancio, Evan Terrell

Faculty Publications

Trans-aconitic acid (TAA) is naturally present in sweet sorghum juice and syrup, and it has been promoted as a potential biocontrol agent for nematodes. Therefore, we developed a process for the extraction of aconitic acid from sweet sorghum syrup. The process economics were evaluated, and the extract was tested for its capability to suppress the motility of the nematodes Caenorhabditis elegans and Meloidogyne incognita. Aconitic acid could be efficiently extracted from sweet sorghum syrup using acetone:butanol:ethanol mixtures, and it could be recovered from this solvent with a sodium carbonate solution, with an overall extraction and recovery efficiency of 86%. The …

Field Applications Of Zein As A Precise Nanoscale Delivery System For Methoxyfenozide, C. A.R. Bonser, C. Tamez, J. C. White, C. E. Astete, C. M. Sabliov, J. A. Davis

Faculty Publications

When insecticides are applied in the environment, much of the product does not reach the target pest. Biopolymeric nanoparticles as nanocarriers have the potential to improve insecticide efficacy by improving absorption, coverage, and permeability while protecting the insecticide active ingredient from abiotic conditions and extending efficacy through controlled release. We conducted a series of experiments using a biopolymeric nanoparticle synthesized from zein, a biodegradable maize protein, to compare efficacy of a nanodelivered hydrophobic insect growth regulator (methoxyfenozide) against a commercial formulation. Positively charged zein nanoparticles (empty and loaded with methoxyfenozide) were compared to the formulated product, Intrepid 2F, as a …

Stored Rice Varietal Resistance Towards Sitophilus Oryzae, Ethan M. Doherty, Qian Sun, Blake E. Wilson

Faculty Publications

Previous research has demonstrated that varieties of rice are differentially susceptible to stored rice pests, but modern varieties are lacking evaluation. Thirteen varieties of rice, Oryzae sativa (L.), were tested for their susceptibility to the rice weevil, Sitophilus oryzae (L.). Sitophilus oryzae adults were placed into vials containing one of 13 USA commercial rice varieties. Adult damage, larval damage, days to eclosion, total progeny, and progeny mass were recorded over a period of six weeks. Subsequently, varietal mixes of the resistant and susceptible varieties were evaluated for associational resistance or susceptibility using the same methodology. Rice variety impacted adult damage, …

Impact Of Nonconventional Selection By Insecticides On Susceptibility Of The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel, James A. Ottea

Faculty Publications

Mosquitoes are an important target of pest control as they vector pathogens that are associated with many debilitating human diseases. Given that mosquitoes have been selected with insecticides for over 100 years, much is known about the development of insecticide resistance associated with targeted application against populations of these insects. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. Here, we show that susceptibility to chlorantraniliprole, which …

Recent Advances And Challenges In Implementing Ipm Programmes In The Entomological Context Of Indian Agriculture, Ruchika Geedi, Gadi V.P. Reddy

Faculty Publications

Integrated pest management (IPM) programmes are based on using multiple methods to maintain nuisance insects below tolerant levels in crop fields. Recent advances in IPM in developed countries have incorporated biological pesticides, microbial products, semiochemicals, and beneficial insects, but few of such programmes have been successfully implemented in developing countries, such as India. Semiochemicals play critical roles as signals in various interspecific and intraspecific interactions between insects and plants, and among interacting insects, plants, and microbes. In India IPM programmes have included mechanical, chemical, cultural, and biological management strategies. However, among these methods, biological management has its own limitations. Indian …

Effects Of Other People's Facial Emotional Expression On Consumers’ Perceptions Of Chocolate Chip Cookies Containing Cricket Protein, Yupeng Gao, Pitchayapat Chonpracha, Bin Li, Witoon Prinyawiwatkul

Faculty Publications

Abstract: Edible insects are recognized as a potential alternative and sustainable source of high-quality protein for the human diet. Entomophagy is highly related to negative emotions that may cause reluctance to adopt insects as food in Western countries. During human interaction, a person's facial emotional expression (FEE) may influence other people's emotional responses. A person's emotional state may affect his/her food preference and food choice. Understanding how other people's FEE would affect consumers’ emotional profiles, liking, and subsequent willingness to try (WTT) and purchase intent (PI) toward insect-containing food products may help increase the acceptance of entomophagy. This study identified …

A Draft Of The Genome Of The Gulf Coast Tick, Amblyomma Maculatum, Jose M.C. Ribeiro, Natalia J. Bayona-Vásquez, Khemraj Budachetri, Deepak Kumar, Julia Catherine Frederick, Faizan Tahir, Brant C. Faircloth, Travis C. Glenn, Shahid Karim

Faculty Publications

The Gulf Coast tick, Amblyomma maculatum, inhabits the Southeastern states of the USA bordering the Gulf of Mexico, Mexico, and other Central and South American countries. More recently, its U.S. range has extended West to Arizona and Northeast to New York state and Connecticut. It is a vector of Rickettsia parkeri and Hepatozoon americanum. This tick species has become a model to study tick/Rickettsia interactions. To increase our knowledge of the basic biology of A. maculatum we report here a draft genome of this tick and an extensive functional classification of its proteome. The DNA from a single …

Land Use And Hydrological Factors Control Concentrations And Diffusive Fluxes Of Riverine Dissolved Carbon Dioxide And Methane In Low-Order Streams, Wei Tang, Y. Jun Xu, Maofei Ni, Siyue Li

Faculty Publications

We analyzed the impacts of land use/land cover types on carbon dioxide (CO2) and methane (CH4) concentration and diffusion in 1st to 4th Strahler order tributaries of the Longchuan River to the upper Yangtze River in China by using headspace equilibration method and CO2SYS program. Field sampling and measurements were conducted during the dry and wet seasons from 2017 to 2019. The average of calculated CO2 partial pressure (pCO2, mean ± SD: 2389 ± 3220 μatm) by CO2SYS program was 1.9-fold higher than the value (mean ± SD: 1230 ± 1440 μatm) 10 years ago in the Longchuan River basin, …

Influence Of River Disconnection On Floodplain Periphyton Assemblages, Kamela De Gallardo, Michael D. Kaller, D. Allen Rutherford, William E. Kelso

Faculty Publications

The Atchafalaya River Basin (ARB) in southcentral Louisiana, USA, is a structurally and biotically diverse floodplain of Atchafalaya River (AR), which is the largest distributary of the Mississippi River. Annual floodplain inundation facilitates the exchange of nutrients and organic material between the AR and its floodplain, giving rise to the high productivity of the river-floodplain system. Production within the ARB is driven by periphytic algae, phytoplankton, and aquatic macrophytes, however, very little is known about periphytic algal assemblages in floodplain systems or how loss of annual flooding impacts these assemblages. In this study, we use artificial substrates to sample periphytic …