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University of Arkansas, Fayetteville

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Full-Text Articles in Engineering

Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr Jan 2023

Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr

Journal of the Arkansas Academy of Science

A morphologically youthful slope failure, herein referred to as the Landfill Landslide, was identified in a remote section of the City of Fort Smith Landfill, and permission was obtained to investigate. The slide on a deforested, NW-facing 27% slope beneath a linear head scarp about 200 meters long. One end of the head scarp curves abruptly downhill and transforms into a distinct lateral scarp greater than 100 meters long. The surface of the slide is about 24,000 m2 (6 acres) in area and is easily distinguished from adjacent intact slopes by its hummocky morphology and transverse ridges and valleys. The …

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Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams Jan 2023

Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams

Journal of the Arkansas Academy of Science

Algae are of scientific and commercial interest due to their ease of culture and high fatty acid content. The extracted fatty acids from these phytoplankton may potentially be used as an additional test for phylogenetic classification of new algal strains (Tonon et al. 2002), as well as in a supplement for human consumption and producing next-generation biofuels. Of interest is the fatty acid content contained within various algal isolates within the class Eustigmatophyceae. Algal strains were collected and isolated from locations in Lake Chicot in Arkansas, Tower Pond and Lake Itasca at Itasca State Park in Minnesota, and Thayer Lake …

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Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors Jan 2023

Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith Jan 2023

Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith

Journal of the Arkansas Academy of Science

Cellular slime molds, Dictyostelium, are bactivorous, soil-dwelling amoebae. When food is available, cells reproduce asexually by binary fission. Under certain environmental conditions, such as darkness and humidity, Dictyostelium reproduces sexually. The sexual cycle is uniquely social and has unusual features. First, sexual reproduction in most eukaryotes usually involves fusion of two gametes. But, in Dictyostelium, triparental inheritance is observed (Bloomfield et al. 2019), in which gamete fusion involves more than two gametes. Second, most eukaryotic species have two sexes or mating types, but Dictyostelium species are known to have more than two mating types. Even though Dictyostelium species show variations …

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Noteworthy Parasites (Trematoda, Cestoda, Phthiraptera) Of Three Birds (Aves: Passeriformes; Pelecaniformes; Piciformes) From Arkansas, C.T. Mcallister, H.W. Robison Jan 2023

Noteworthy Parasites (Trematoda, Cestoda, Phthiraptera) Of Three Birds (Aves: Passeriformes; Pelecaniformes; Piciformes) From Arkansas, C.T. Mcallister, H.W. Robison

Journal of the Arkansas Academy of Science

Between November 2020 and March 2021, three species of birds, one each of a tufted titmouse (Baeolophus bicolor), pileated woodpecker (Dryocopus pileatus), and great blue heron (Ardea herodias) were salvaged from Lawrence and Polk counties, Arkansas, and examined for parasites. Found were four taxa of parasites, including a dicrocoeliid trematode, a cyclophyllidean cestode, and species of philopterid and menoponid lice. We document new host and distributional records for these parasites from select birds of the state.

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New Geographic Distributional Records For Two Lampreys (Petromyzontiformes: Petromyzontidae) In Arkansas, With Notes On Histopathology, C.T. Mcallister, H.W. Robison, E.M. Leis, D.G. Cloutman, A.C. Camus Jan 2023

New Geographic Distributional Records For Two Lampreys (Petromyzontiformes: Petromyzontidae) In Arkansas, With Notes On Histopathology, C.T. Mcallister, H.W. Robison, E.M. Leis, D.G. Cloutman, A.C. Camus

Journal of the Arkansas Academy of Science

The recent update (2nd edition) of the Fishes of Arkansas includes what is known, to date, on the geographic distribution of five species of lampreys that occur in the state. Here, we provide new distributional records on two of those species, the chestnut lamprey (Ichthyomyzon castaneus) and southern brook lamprey (I. gagei), as well as documenting host-parasite information (histopathology) caused by the former species.

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Spermiogenesis In The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth Jan 2023

Spermiogenesis In The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth

Journal of the Arkansas Academy of Science

I investigated spermiogenesis in the Western Siren, Siren nettingi (formerly Western Lesser Siren, Siren intermedia nettingi) from salamanders collected periodically over a span of 21 yr (1994–2015) in northeastern Arkansas. My primary objective in this study is to present histologically and ultrastructurally, for the first time, the novel sequence of spermatological events of the spermiogenic process in this species. I describe the transformational stages from secondary spermatocytes to mature biflagellated spermatozoa, all of which occur within the lumen of testicular lobules. These new-to-science processes begin with nuclear displacement and expansion within spermatids, which occur after their detachment from Sertoli cells …

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Histomorphology Of The Distal Urogenital Ducts In The Male Northern Crawfish Frog, Rana Areolata Circulosa (Anura: Ranidae), S.E. Trauth, R.G. Neal Jan 2023

Histomorphology Of The Distal Urogenital Ducts In The Male Northern Crawfish Frog, Rana Areolata Circulosa (Anura: Ranidae), S.E. Trauth, R.G. Neal

Journal of the Arkansas Academy of Science

We examined the microanatomy of the distal urogenital ducts in the male Northern Crawfish Frog (Rana areolata circulosa) from a small sample (n = 5) collected in February and March from central Arkansas over a 5-year period (2017–2022). Specifically, we sought information on the following structures: (1) the paired Wolffian (urogenital) ducts caudally from the kidneys to their merging with the urodeum of the cloaca, (2) the paired seminal vesicles (sperm storage structures), and (3) the paired Müllerian ducts and glands. This study provides new information on these urogenital ducts and promotes a clearer understanding of this anatomical region for …

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No Sperm Morphometric Differences Between Two Snapping Turtle Species, J.D. Konvalina, S.E. Trauth Jan 2023

No Sperm Morphometric Differences Between Two Snapping Turtle Species, J.D. Konvalina, S.E. Trauth

Journal of the Arkansas Academy of Science

We examined sperm morphometrics between Chelydra serpentina and Macrochelys temminckii. When both species are combined, we found significant correlations between total sperm length and sperm head length as well as sperm tail length and sperm head length. In addition, we observed significant correlations between total sperm length and sperm tail length. T-tests revealed no significant differences in any of the sperm morphometrics between the two species. Both snapping turtle species had greater values for every sperm morphometric when compared to another freshwater turtle. The strong correlation between total sperm length and sperm tail length is concurrent with what has previously …

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New Species Of Birds Reported In Arkansas Since 2009, R. Tumlison, R. Kannan Jan 2023

New Species Of Birds Reported In Arkansas Since 2009, R. Tumlison, R. Kannan

Journal of the Arkansas Academy of Science

We update our state of knowledge regarding the 20 new species of birds (and 1 new species name based on a change in taxonomy) discovered in Arkansas since the last update in 2009. These are based on records of the Arkansas Audubon Society and those posted on eBird. New species include 3 from Order Anseriformes, 1 Pelicaniformes, 1 Falconiformes, 1 Gruiformes, 4 Charadriiformes, 1 Apodiformes, and 10 Passeriformes. Historic distributions of the new species include Atlantic, Pacific, and Gulf Coasts, as well as interior origins. The current count of extant species of birds observed in Arkansas now stands at 425.

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Keynote Address And Meeting Program, Academy Editors Jan 2023

Keynote Address And Meeting Program, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Instructions To Authors, Academy Editors Jan 2023

Instructions To Authors, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors Jan 2023

Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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New Records Of Distribution And Natural History Of Vertebrates In Arkansas: 2020-2023, R. Tumlison, H.W. Robison, M.B. Connior, D.B. Sasse, T.S. Risch, K. Edmonds, J.D. Wilhide, C.R. Allen Jan 2023

New Records Of Distribution And Natural History Of Vertebrates In Arkansas: 2020-2023, R. Tumlison, H.W. Robison, M.B. Connior, D.B. Sasse, T.S. Risch, K. Edmonds, J.D. Wilhide, C.R. Allen

Journal of the Arkansas Academy of Science

Small details of natural history often go undocumented to science if those details are not parts of larger studies. However, knowledge of small details can provide insights that lead to interesting questions about ecological relationships or environmental change. We have compiled recent important observations of natural history of vertebrates, including several distributional and size records of fishes, atypical carapace shape in a common snapping turtle, an unusual support structure for a bird nest, healed damage to a broken jaw of a young deer, and numerous distributional records of bats.

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New Host Records Of Apicomplexan Blood Parasites (Haemogregarinidae And Hepatozoidae) Infecting Two Reptiles (Testudines; Ophidia) From Arkansas, C.T. Mcallister, H.W. Robison Jan 2023

New Host Records Of Apicomplexan Blood Parasites (Haemogregarinidae And Hepatozoidae) Infecting Two Reptiles (Testudines; Ophidia) From Arkansas, C.T. Mcallister, H.W. Robison

Journal of the Arkansas Academy of Science

Relatively few records of apicomplexan blood parasites from reptiles in Arkansas have been published although the effects of these parasites on reptilian health may be of concern. Using photomicrographs we describe the morphotypes of parasite gamonts found in blood samples from the Midland smooth softshell turtle, Apalone mutica mutica, and a western Milksnake Lampropeltis gentilis from Arkansas. The turtle possessed four distinct morphological gamont forms of a Haemogregarina sp. The snake possessed two morphological forms of gamonts of a Hepatozoon sp. Both infections are new host records and the western milksnake has not been described as a host elsewhere for …

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Hemoparasites (Apicomplexa: Hepatozoon; Kinetoplastida: Trypanosoma) Of Two Anurans (Hylidae; Ranidae), From Polk County, Arkansas, C.T. Mcallister, H.W. Robison Jan 2023

Hemoparasites (Apicomplexa: Hepatozoon; Kinetoplastida: Trypanosoma) Of Two Anurans (Hylidae; Ranidae), From Polk County, Arkansas, C.T. Mcallister, H.W. Robison

Journal of the Arkansas Academy of Science

Arkansas supports 26 species/subspecies of anurans and only one (4%), the green frog, Rana clamitans, has been previously reported with hemoparasites. Here, we collected blood samples from three species of anurans, five American green treefrogs, Dryophytes cinereus, five American bullfrogs, Rana catesbeianus, two southern leopard frogs, Rana sphenocephalus utricularius, and two Fowler’s toads, Anaxyrus fowleri from Polk County and examined each for hemoparasites. American green treefrogs and American bullfrogs harbored hemoparasites, including two (40%) D. cinereus and four (80%) R. catesbeianus with trypanosomes, and one (20%) R. catesbeiana with a Hepatozoon sp. This is the first time these two anurans …

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Novel Reproductive Data On Blue Sucker, Cycleptus Elongatus (Cypriniformes: Catostomidae), From Northeastern Arkansas, C.T. Mcallister, D.G. Cloutman, E.M. Leis, H.W. Robison Jan 2023

Novel Reproductive Data On Blue Sucker, Cycleptus Elongatus (Cypriniformes: Catostomidae), From Northeastern Arkansas, C.T. Mcallister, D.G. Cloutman, E.M. Leis, H.W. Robison

Journal of the Arkansas Academy of Science

Nothing has been published in the scientific literature concerning the reproductive biology of the Blue Sucker, Cycleptus elongatus in Arkansas. We examined seven female C. elongatus collected in late February 2021 and 2022 and again in early March 2023 from the Black River, Lawrence County. Egg mass (g) averaged 15.8% of the total weight of these gravid females. It appears that this sucker can spawn as early as February in this population. This is the first time information on female reproduction in this species has been published from any population of C. elongatus in the state.

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Rare Birds In Arkansas: Historical Observations And New Records, R. Tumlison, R. Kannan Jan 2023

Rare Birds In Arkansas: Historical Observations And New Records, R. Tumlison, R. Kannan

Journal of the Arkansas Academy of Science

Diligent members of birding communities are quick to report rare sightings of birds, which often lead to multiple observations and photographic documentation. Verified reports and images of birds in Arkansas are curated by the Arkansas Audubon Society (AAS), which has led to an appreciation of which species are common versus rare. We gathered historic (literature) and more recent unpublished records of rare birds (those with fewer than 10 reports, per AAS) to document the historic and current state of knowledge of those species. Currently, there are a total of 425 species of birds reported in Arkansas, of which 54 are …

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Journal Acknowledgements And Editorial Board, Academy Editors Jan 2023

Journal Acknowledgements And Editorial Board, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Table Of Contents, Academy Editors Jan 2023

Table Of Contents, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Effects Of Electrodes Layout On Performance Of Millimeter-Wave Transistors, Soheil Nouri, Samir M. El-Ghazaly Jan 2023

Effects Of Electrodes Layout On Performance Of Millimeter-Wave Transistors, Soheil Nouri, Samir M. El-Ghazaly

Electrical Engineering Faculty Publications and Presentations

This work presents a systematic parameter extraction methodology for modeling of millimeter-wave transistors. The physics-based parameter extraction approach in this study is included in the wave-electron-transport model to improve the accuracy of the simulation results. The effects of extrinsic parameters on the performance of the device are also analyzed in detail. Skin effects and sharp metallization edge effects as the two physical phenomena that impact the current distribution and the resistance of millimeter-wave transistors are studied thoroughly. Two common electrode layout variations, the T configuration and the fork configuration, are compared. The comparison mainly targeted their performance on upper millimeter …

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Detection And Localization Of Data Forgery Attacks In Automatic Generation Control, Fengli Zhang, Yatish R. Dubasi, Wei Bao, Qinghua Li Jan 2023

Detection And Localization Of Data Forgery Attacks In Automatic Generation Control, Fengli Zhang, Yatish R. Dubasi, Wei Bao, Qinghua Li

Electrical Engineering Faculty Publications and Presentations

Automatic Generation Control (AGC) is a key control system to maintain the power system’s balance between load and supply by maintaining its frequency in a specific range. It collects the tie-line power flow and frequency measurements of each control area to calculate the Area Control Error (ACE) and then adjusts power generation based on the calculated ACE. However, malicious frequency or tie-line power flow measurements can be injected and then AGC is misled to make false power generation adjustments which will harm power system operations. Such attacks can be carefully designed to pass the power system’s existing bad data detection …

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The Rayleigh Problem (Random Flights) Is Everywhere Redux, John E. Gray, Stephen R. Addison Jan 2023

The Rayleigh Problem (Random Flights) Is Everywhere Redux, John E. Gray, Stephen R. Addison

Journal of the Arkansas Academy of Science

The phase noise problem (or Rayleigh problem) occurs in all aspects of radar. It is an effect that a radar engineer or physicist always has to take into account as part of a design or in an attempt to characterize the physics of a problem such as reverberation. Normally, the mathematical difficulties of phase noise characterization are avoided by assuming the phase noise probability distribution function (PDF) is uniformly distributed, and the Central Limit Theorem (CLT) is invoked to argue that the superposition of relatively few random components obey the CLT and hence the superposition can be treated as a …

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Least Flycatchers Under-Reported In Fall Migration In Arkansas —A Citizen Science Conundrum, L. Barnes, R. Kannan Jan 2023

Least Flycatchers Under-Reported In Fall Migration In Arkansas —A Citizen Science Conundrum, L. Barnes, R. Kannan

Journal of the Arkansas Academy of Science

The Least Flycatcher Empidonax minimus is a small passerine migrant bird that passes through Arkansas in fall and spring migration. The birds are vocal during spring passage but relatively quiet and unobtrusive during fall migration, leading to many fewer reports by birdwatchers in fall than spring. We use eBird maps and data to present evidence to support this discrepancy between fall and spring observations. We also show that the species is under-reported in Arkansas during the fall compared to neighboring regions. This may be in part due to the reluctance of some birders to provide the minimal evidence required to …

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Citizen Science: Role Of Inaturalist In Biodiversity Documentation And Education In Arkansas, K. Baker, L. Barnes, S. Rana, J. Jackson, R. Kannan Jan 2023

Citizen Science: Role Of Inaturalist In Biodiversity Documentation And Education In Arkansas, K. Baker, L. Barnes, S. Rana, J. Jackson, R. Kannan

Journal of the Arkansas Academy of Science

iNaturalist is a global online digital platform for documenting and fostering interest in biodiversity, with Research Grade (RG) entries being vetted and scientifically valid observations. Here we present a review of the role of approximately 16,000 Arkansans using the iNaturalist tool for recording 445,000 verifiable observations comprising 10,800 species, with 40 percent RG, and one third of observations still pending confirmation. Overall, plants lead in RG observations followed by invertebrates and birds. Within these groups, reptiles lead in proportion of RG observations, followed by birds and amphibians. Less charismatic or infrequently encountered organisms are less represented. Arkansas ranks about average …

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A Partial Discharge Inception Voltage Modeling Approach, Shilpi Mukherjee, Tristan Mark Evans, David Huitink, H. Alan Mantooth Jan 2023

A Partial Discharge Inception Voltage Modeling Approach, Shilpi Mukherjee, Tristan Mark Evans, David Huitink, H. Alan Mantooth

Electrical Engineering Faculty Publications and Presentations

A partial discharge inception voltage modeling approach promoting design-for-reliability considerations in advanced power modules is presented. As power modules are being operated at higher voltages and become more compact to meet power density demands, there is an increased risk of partial discharge, the silent precursor to electrical breakdown that degrades insulation material. The trade-off between voltage class and module compaction must be quantified. This work presents a methodology to model the tradeoff for any substrate and encapsulant material. A surface charge density-based partial discharge inception voltage (PDIV) model was developed to overcome the challenges in electric field-based models. The model …

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Energy Content Of Grasshoppers (Orthoptera: Acrididae) In The Diet Of Scaled Quail (Callipepla Squamata) In Southeastern New Mexico, J.L. Hunt, M.E. Grilliot, T.L. Best, C.M. Wilkerson, A.F. Huitt Jan 2023

Energy Content Of Grasshoppers (Orthoptera: Acrididae) In The Diet Of Scaled Quail (Callipepla Squamata) In Southeastern New Mexico, J.L. Hunt, M.E. Grilliot, T.L. Best, C.M. Wilkerson, A.F. Huitt

Journal of the Arkansas Academy of Science

Grasshoppers (Orthoptera: Acrididae) are common insects that are important food items for many kinds of wildlife, including many species of upland game birds such as scaled quail (Callipepla squamata). We analyzed the energy content of grasshoppers obtained from the crops of scaled quail collected from plainsmesa sand-scrub in Lea and Eddy counties, New Mexico. Grasshoppers were removed from crops and dried for 48 hours at 60°C to remove moisture and standardize masses. Grasshoppers were then pulverized and analyzed for gross caloric value (i.e., energy content) in an oxygen bomb calorimeter. Energy content of grasshoppers from New Mexico averaged 19.2 J/kg …

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In-Situ Tribology Of Engineered Surfaces With 3d-Printed Micro/Nano-Textures, Mahyar Afshar Mohajer Dec 2022

In-Situ Tribology Of Engineered Surfaces With 3d-Printed Micro/Nano-Textures, Mahyar Afshar Mohajer

Graduate Theses and Dissertations

Surface texturing is an effective way to reduce the adhesion and friction between two contacting surfaces by reducing the real area of contact between them, providing a potential solution for adhesion and friction-induced failures, for example, failures in micro-/nano-electromechanical systems (MEMS/NEMS). Surface texturing is also essential to the realization of functional surfaces such as superhydrophobic/philic and icephobic surfaces. However, textures are prone to deformation due to being subjected to higher contact pressures. The advancement of 3D nanoprinting by two-photon lithography (TPL), combined with the ability to make an in-situ observation of the interplay between the forces and the sliding surfaces …

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Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez Dec 2022

Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez

Graduate Theses and Dissertations

Weathering steel enhances corrosion-resistant steel features over conventional steel when a patina properly forms on the weathering steel surface. Weathering steel is a low carbon steel of less than 0.3% carbon by weight and has a chemical composition including other alloying elements such as nickel, copper, and chromium that develops a patina. The patina is a dense protective oxide film layer that develops on the steel member surface. The patina defends the steel from corrosion by preventing moisture, oxygen, and contaminant penetration. However, long periods of moisture and deicing chemicals applied during wet wintry conditions hinder proper patina formation. Without …

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Interfacial Engineering Of Nickel-Rich Layered Oxide Cathodes Via Atomic Layer Deposition (Ald), Xin Wang Dec 2022

Interfacial Engineering Of Nickel-Rich Layered Oxide Cathodes Via Atomic Layer Deposition (Ald), Xin Wang

Graduate Theses and Dissertations

Layered nickel-rich cathodes LiNixMnyCozO2 (NMCs, x + y + z =1, x ≥ 0.6) are regarded as one of the most promising cathode materials for next-generation lithium-ion batteries (LIBs), given their remarkably reduced cost and increased capacity compared to the conventional LiCoO2 cathode. However, the deployment of these Ni-rich cathodes has been hindered by the continuous loss of practical capacity and reduction in average working voltage, inherently due to their interfacial, structural, and thermodynamic instability. To address these issues, interfacial engineering via surface modification has been well-recognized as an effective strategy and a large number of coating materials have been …

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