Physical Sciences and Mathematics Commons^™

Fundamentals Of Electrochemical Impedance Spectroscopy For Macrohomogeneous Porous Electrodes, Xiang Li, Qiu-An Huang, Wei-Heng Li, Yu-Xuan Bai, Jia Wang, Yang Liu, Yu-Feng Zhao, Juan Wang, Jiu-Jun Zhang

Journal of Electrochemistry

Electrochemical impedance spectroscopy (EIS) can be used to diagnose charge transfer reactions and mass transport in porous electrodes. The charge transfer reactions include interfacial charge accumulation and charge conduction as well as electrochemical reaction. In this paper, the complex phasor method is developed under the macrohomogeneous assumption to build an impedance model of porous electrodes for clarifying several vague expressions in the traditional approaches. The following researches are carried out: (1) Identifying characteristic parameters for the porous electrodes, including electrode electronic conductivity σ₁, electrolyte ionic conductivity σ₂, interface charge transfer conductivity g_ct, unit area …

Application Of Ti/Ruo2-Iro2-Sno2-Sb2O5 Anode In Rural Drinking Water Disinfection, Jing-Ru Guo, Xue-Jiao Zhang, Shuai Liao, Xue-Ming Chen

Journal of Electrochemistry

Sodium hypochlorite disinfection has many advantages, including reliable operation, low cost, easily available raw materials. It is, therefore, suitable for disinfection of drinking water in remote rural areas. The service life and chlorine evolution efficiency of the anode are the main factors restricting the performance of the sodium hypochlorite generator. The special conditions of frequent shutdown and low electrolyte concentration in the rural drinking water application also put forward high requirements on the performance of the anode. In this study, Ti/RuO₂-IrO₂-SnO₂-Sb₂O₅,a new-type and efficient chlorine evolution anode, was prepared by …

Characterization Of Cdom In The Elkhorn Slough Estuary Using Eem Spectroscopy And Its Potential For Macrophyte Monitoring, María Vila Duplá

Faculty Research, Scholarly, and Creative Activity

The Elkhorn Slough estuary is an upwelling-influenced system located in Monterey Bay, California. It is of great ecological importance, as it provides essential habitat to over 750 species, and is one of the largest estuaries in California. The sources and distribution of chromophoric dissolved organic matter (cDOM) in Elkhorn Slough are strongly influenced by geochemical processes linked to the transition between sea and continent, and to anthropogenic activity from adjacent lands. In 2016, water samples were collected from across the Elkhorn Slough estuary to assess the sources and spatial dynamics of cDOM and its components throughout the system. Using EEM …

Climate-Assisted Persistence Of Tropical Fish Vagrants In Temperate Marine Ecosystems, Laura Gajdzik, Thomas M. Decarlo, Adam Koziol, Mahsa Mousavi-Derazmahalleh, Megan Coghlan, Matthew W. Power, Michael Bunce, David Fairclough, Michael J. Travers, Glenn I. Moore, Joseph D. Dibattista

Fisheries Research Articles

Rising temperatures and extreme climate events are propelling tropical species into temperate marine ecosystems, but not all species can persist. Here, we used the heatwave-driven expatriation of tropical Black Rabbitfish (Siganus fuscescens) to the temperate environments of Western Australia to assess the ecological and evolutionary mechanisms that may entail their persistence. Population genomic assays for this rabbitfish indicated little genetic differentiation between tropical residents and vagrants to temperate environments due to high migration rates, which were likely enhanced by the marine heatwave. DNA metabarcoding revealed a diverse diet for this species based on phytoplankton and algae, as well …

Effects Of Agroforestry Practices On Soil Properties In The Drylands Of Eastern Kenya, Nicholas Syano Mutuku, Moses M. Nyangito, Geoffrey Kironchi, Oliver Vivian Wasonga

IGC Proceedings (1993-2023)

Drylands, which are home to about 2 billion people face a myriad of problems among them low land productivity. Agroforestry is one of the land use practices that is perceived to be sustainable with beneficial effects on soil properties. However, the effects of agroforestry practices on soils especially in the drylands have rarely been quantified and studied in details. The study determined the effects of selected agroforestry practices on soil properties in Makueni County of Kenya where agroforestry has been promoted by various organizations. Four soil samples were collected at 0-15cm, 15-30cm, 30-45cm and 45-60cm depths in a zigzag pattern …

Adaptive, Multi-Paddock, Rotational Grazing Management: An Experimental, Ranch-Scale Assessment Of Effects On Multiple Ecosystem Services, D. J. Augustine, J. D. Derner, L. M. Porensky, H. Wilmer, María E. Fernández-Giménez, David D. Briske

IGC Proceedings (1993-2023)

Decisions on how to move livestock in space and time are central to rangeland management. Despite decades of small-scale research, substantial uncertainty exists regarding the relative importance of cattle stocking rates per se, versus the movement of cattle in both space and time, in achieving desired vegetation and livestock outcomes at scales relevant to livestock producers. We report on a ranch-scale experiment comparing effects of collaborative, adaptive, multi-paddock, rotational management (CARM) versus more traditional, season-long, continuous rangeland management (TRM) on perennial grass density and production, cattle performance, and wildlife habitat, while holding the annual stocking rate the same in …

Water Use Efficiency And Land Cover Variability On A Native Grassland Ranch On The Pampa Biome Of Uruguay, Diana L. Restrepo-Osorio, Gabriel De Oliveira, James Coll, Daniela Schossler

IGC Proceedings (1993-2023)

Global efforts towards sustainable cattle ranching should be based on comprehensive approaches, targeting physical variables of the ranching process, as well as, the socioeconomic dimensions. Alianza del Pastizal is a non-profit conservation organization that works to preserve the temperate grasslands of the Southern Cone of South America by promoting conservation practices among ranching communities in Uruguay, Paraguay, Argentina, and Brazil. Alianza has become a mediator for ranchers exchanging information, resources, and education. Ranchers associated with the Alliance take pride in their property management as they aim to improve the community wellbeing and natural resource sustainability. In a previous study, producers …

Revisiting The Concept Of The Planning Region In Settings With Dynamic Spatial-Temporal Conditions: Lessons From Land Use Planning In Pastoral Areas Of Kenya, Ethiopia And Tanzania, H. Musoga, L. W. Robinson

IGC Proceedings (1993-2023)

Pastoralist rangeland systems often provide prime examples of scale mismatch—the challenge that arises when the scale and geographic extent of decision-making institutions do not correspond to the scale and geographic extent of problems that need to be addressed. Pastoralist resource use and traditional governance systems operate at multiple levels, and are often characterized by multiple, overlapping claims, rights, and management territories. Scholarship on pastoralist systems suggests that their fuzziness, flexibility, and overlap in territories and rights mean that there is no single scale or level that is optimal for effective resource governance. These characteristics stymie attempts to implement conventional …

Ewe Daily-Weight Gain Grazing Leucaena Leucocephala-Megathyrsus Maximus Cv Mombasa Silvopastoral System And Tropical Native Unimproved Range, L. K. Trejo-Arista, Enrique Cortés-Díaz, P. A. Martínez-Hernández, J. A. Cadena-Meneses

IGC Proceedings (1993-2023)

Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m² plot. Variables measured on …

Cache-Friendly, Modular And Parallel Schemes For Computing Subresultant Chains, Mohammadali Asadi

Electronic Thesis and Dissertation Repository

The RegularChains library in Maple offers a collection of commands for solving polynomial systems symbolically with taking advantage of the theory of regular chains. The primary goal of this thesis is algorithmic contributions, in particular, to high-performance computational schemes for subresultant chains and underlying routines to extend that of RegularChains in a C/C++ open-source library.

Subresultants are one of the most fundamental tools in computer algebra. They are at the core of numerous algorithms including, but not limited to, polynomial GCD computations, polynomial system solving, and symbolic integration. When the subresultant chain of two polynomials is involved in a client …

Status, Management, And Governance Of The Communal Grasslands Of Ethiopia’S Highlands: A Disappearing Asset For Mixed Crop-Livestock Livelihood Systems, Bedasa Eba, Fiona Flintan, Tesfa Getachew, Jason Sircely

IGC Proceedings (1993-2023)

There is little documentation about the status, management, and governance of the communal grasslands of Ethiopia’s highlands. However, research being carried out by ILRI (International Livestock Research Institute) in northern Shewa, Amhara region, is highlighting their importance as a critical resource for those farmers engaged in mixed crop-livestock livelihood systems across the highland areas. These grassland areas range from 2 to 200 hectares and can be used by up to four different villages or ‘kebele’ and providing on average 10-20% of livestock feed for local farmers. However, this important resource is rapidly disappearing with encroachment of farming and tree-planting with …

Automated Detection And Characterization Of Mesocyclones In X-Band Radar Observations, Raychel E. Nelson

The Journal of Purdue Undergraduate Research

No abstract provided.

Participatory Action Research: Undergraduate Researchers Engaging Secondary Students In Social Justice Mathematics, Isabelle Miller, Alexis Grimes, Camryn Adkison

The Journal of Purdue Undergraduate Research

No abstract provided.

The Effects Of Climate Change On The Vertical Structure Of Severe Weather Environments, Isaac Davis

The Journal of Purdue Undergraduate Research

No abstract provided.

The Effects Of Environmental Copper Exposure On The Behavior And Morphology Of Developing Zebrafish, Christina Kaucic

The Journal of Purdue Undergraduate Research

No abstract provided.

Automated Data Processing: Making Community Indicators Possible For Lafayette, Indiana, Jace T. Newell, Eli W. Coltin, Eric D. Flaningam

The Journal of Purdue Undergraduate Research

No abstract provided.

Experience Doesn't Matter, But The Direction Does, Hailey Blythe

The Journal of Purdue Undergraduate Research

No abstract provided.

A Nosy Neighbor: Purification And Functional Characterization Of Lpg2149, Ashley M. Holahan

The Journal of Purdue Undergraduate Research

Ubiquitination is a process that marks proteins for various cell-signaling pathways, namely protein degradation and other processes. Th ese pathways are essential in a wide array of cellular processes, including defense mechanisms against invading pathogens. Th e ubiquitination process is universally found in all eukaryotic organisms, including plants and animals, and thus plays a vital role in cellular homeostasis. Recently, more discoveries have been made on prokaryotic effector proteins that hijack the ubiquitination system even when they do not possess a ubiquitin system of their own. MavC, also known as lpg2147 (Gan, Nakayasu, Hollenbeck, & Luo, 2019; Puvar et al., …

Accident Experiences And Reporting Practices In Canadian Chemistry And Biochemistry Labs: A Pilot Investigation, Dana Ménard, John F. Trant

Chemistry and Biochemistry Publications

Accidents in chemistry and biochemistry laboratories are a regular occurrence and have been associated with injuries, property damage, and deaths. However, despite a high prevalence rate of accident involvement reported in previous investigations of academic lab personnel (approximately 30%), little is known about the context in which academic lab accidents occur. Previous findings also suggest a high degree of accident underreporting (25–40%), but again, little is known about this phenomenon. Pilot data was gathered from a convenience sample of 104 students and postdoctoral fellows in chemistry-related fields through an online survey. Results showed a high level of accident involvement (56.7%); …

Removal Of The Northern Paleo-Teton Range Along The Yellowstone Hotspot Track, J. Ryan Thigpen, Summer J. Brown, Autumn L. Helfrich, Rachel Hoar, Michael M. Mcglue, Edward W. Woolery, William R. Guenthner, Meredith L. Swallom, Spencer Dixon, Sean Gallen

Earth and Environmental Sciences Faculty Publications

Classically held mechanisms for removing mountain topography (e.g., erosion and gravitational collapse) require 10-100 Myr or more to completely remove tectonically generated relief. Here, we propose that mountain ranges can be completely and rapidly (< 2 Myr) removed by a migrating hotspot. In western North America, multiple mountain ranges, including the Teton Range, terminate at the boundary with the relatively low relief track of the Yellowstone hotspot. This abrupt transition leads to a previously untested hypothesis that preexisting mountainous topography along the track has been erased. We integrate thermochronologic data collected from the footwall of the Teton fault with flexural-kinematic modeling and length-displacement scaling to show that the paleo-Teton fault and associated Teton Range was much longer (min. original length 190-210 km) than the present topographic expression of the range front (~65 km) and extended across the modern-day Yellowstone hotspot track. These analyses also indicate that the majority of fault displacement (min. 11.4-12.6 km) and the associated footwall mountain range growth had accumulated prior to Yellowstone encroachment at ~2 Ma, leading us to interpret that eastward migration of the Yellowstone hotspot relative to stable North America led to removal of the paleo-Teton mountain topography via posteruptive collapse of the range following multiple supercaldera (VEI 8) eruptions from 2.0 Ma to 600 ka and/or an isostatic collapse response, similar to ranges north of the Snake River plain. While this extremely rapid removal of mountain ranges and adjoining basins is probably relatively infrequent in the geologic record, it has important implications for continental physiography and topography over very short time spans.

Sustaining Diversity In Higher Education: The Importance Of Investigating Success, Lisa C. Huebner

Sustainability Research & Practice Seminar Presentations

No abstract provided.

Mgrre_Pureoilscouttickets_Pinder_2_21127022210000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

Multi-Valued Solutions For The Equation Of Motion, Darcy-Jordan Model, As A Cauchy Problem: A Shocking Event, Chandler Shimp

Master's Theses

Shocks are physical phenomenon that occur quite often around us. In this thesis we examine the occurrence of shocks in finite amplitude acoustic waves from a numerical perspective. These waves, or jump discontinuities, yield ill-behaved solutions when solved numerically. This study takes on the challenge of finding both single- and multi-valued solutions.

The previously unsolved problem in this study is the representation of the Equation of Motion (EoM) in the form of the Darcy-Jordan model (DJM) and expressed as a dimensionless IVP Cauchy problem. Prior attempts to solve have resulted only in implicit solutions or explicit solutions with certain initial …

Modeling The Ambient Conditions Of A Manufacturing Environment Using Computational Fluid Dynamics (Cfd), Yang Liu

USF Tampa Graduate Theses and Dissertations

As manufacturing equipment evolve to higher speed and require high precision operations, the impact of environmental changes on machine accuracy becomes critical. Due to thermal expansion, the structure of the machine can change when ambient temperature varies. When the airflow in the laboratory changes, this also alters the operator's thermal comfort. Either the change in machine structure or operator comfort can ultimately affect machine accuracy. The manufacturing industry is currently using heating, ventilation, and air-conditioning (HVAC) systems to regulate the temperature of the working environment. However, since conventional HVAC systems determine whether to activate the HVAC system by collecting the …

Expansion-Contraction: Spatial And Temporal Variability In Connectivity In A Stream-Wetland Flow Network, Savannah Fransbergen

USF Tampa Graduate Theses and Dissertations

The seasonal expansion and contraction in a stream-wetland flow network is often difficult to characterize due to a lack of accurate mapping products, but proper characterization is important for the management of these resources. A new approach to mapping hydrography, resulting in a Regional Hydrography Dataset (RHD), may offer additional insights not provided by the national standard, the National Hydrography Dataset (NHD). The RHD can be customized to provide seasonal or monthly hydrograph, whereas the NHD is static. We conducted field validation (241 sites) and geospatial analyses to assess the accuracy of these products in the northern Tampa Bay Area. …

An Assessment Of Nutrient Improvement In Surface Water Due To The Conversion Of Onsite Sewage Treatment And Disposal Systems To Sewerage, Jenelle A. Mohammed

USF Tampa Graduate Theses and Dissertations

Florida represents approximately 12% of all onsite sewage treatment and disposal systems (OSTDS) in the United States. Properly designed, constructed and maintained OSTDS are effective eco- friendly alternatives for the treatment of domestic wastewater from households not serviced by public sewer systems. However, conventional OSTDS are not designed to effectively remove nitrogen. If installed and improperly used, they may contribute other pollutants. OSTDS have also been linked to degraded water quality in some regions. However, it has been difficult to quantify OSTDS impacts on water quality because of various confounding factors such as point and non-point sources of nutrient input. …

Slow Slip Events And The Earthquake Cycle, Nicholas K. Voss

USF Tampa Graduate Theses and Dissertations

Slow Slip Events (SSEs) represent a new type of strain release along faults, which have onlybeen recognized as a global phenomena with the growth of precision space-borne geodetic techniques. These events represent an important part of the strain budget on faults, sometimes bounding the area of co-seismic release and perhaps limiting the amount of seismic energy release. SSEs have also been suggested to proceed large megathrust earthquakes including the great 2011 Tohoku and 2015 Iquique earthquakes. I document a series of SSE along the Nicoya Peninsula in Costa Rica. These events take place both before and after the 2012 M7.6 …

Non-Poissonian Ultrashort Nanoscale Electron Pulses, Sam Keramati, Will Brunner, T. J. Gay, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

The statistical character of electron beams used in current technologies, as described by a stream of particles, is random in nature. Using coincidence measurements of femtosecond pulsed electron pairs, we report the observation of sub-Poissonian electron statistics that are nonrandom due to two-electron Coulomb interactions, and that exhibit an antibunching signal of 1 part in 4. This advancement is a fundamental step toward observing a strongly quantum degenerate electron beam needed for many applications, and in particular electron correlation spectroscopy.

Mr-Guided Radiotherapy (Mrgrt) For Laryngeal Cancer With Real-Time Visualization Of Intrafraction Larynx Motion, Cody Autrey, Kathryn Mittauer, Diane Alvarez, Michael Chuong, Jessika Contreras, Alonso Gutierrez, Adeel Kaiser, James Mcculloch, Tino Romaguera, Noah Kalman

EGS Content

Purpose/Objective(s): Although early larynx cancers require treatment of only the vocal cord(s), radiation forearly larynx cancer historically consisted of opposed lateral portals that included the entire larynx. Treatmenttechniques have advanced to 3D conformal and intensity modulated radiotherapy (IMRT), but the treatment targethas remained the entire larynx. One concern preventing volume reduction in these patients is periodic swallowingthat occurs during treatment delivery due to normal patient physiology. Such intrafraction swallowing candisplace the treatment target up to 2 cm and could lead to tumor underdosing. Treatment with real-time targettracking could greatly mitigate this concern. Herein, we describe our initial experience using MR-guidedradiotherapy …

Multi-Object Localization In Robotic Hand, Tsing Tsow

USF Tampa Graduate Theses and Dissertations

We have developed a machine learning approach to localized objects inside a robotic hand using only images from 2D cameras. Specifically, we used deep learning method (You Only Look Once, YOLO) and Iterative closest Point (ICP) to estimate the 3D coordinates of the objects in a robotic hand. This method will also output the number of objects inside the robotic hand in addition to the coordinates of the objects. We have demonstrated the performance with simulation and obtained typical accuracy within a few pixels (couple mm) and counting accuracy of about 76%. We have also applied it to real images, …