Physical Sciences and Mathematics Commons^™

The Impact Of Biochar's Physicochemical Properties On Sorption Of Perfluorooctanoic Acid (Pfoa), Karen Ane Skjennum, Katinka M. Krahn, Erlend Sørmo, Raoul Wolf, Aleksandar I. Goranov, Patrick G. Hatcher, Thomas Hartnik, Hans Peter H. Arp, Andrew R. Zimmerman, Yaxin Zhang, Gerard Cornelissen

Chemistry & Biochemistry Faculty Publications

To better characterize properties governing the sorption of per- and polyfluoroalkyl substances (PFAS) to biochar, twenty-three diverse biochars were characterized and evaluated as sorbents for perfluorooctanoic acid (PFOA). Biochars were produced at various temperatures, using two different technologies, and made from sewage sludge, food waste reject, wood wastes, and one reference substrate (wood pellets). The biochars were characterized in terms of surface area, pore volume and pore size distributions, elemental composition, leachable elements, ash content, pH, zeta potential, condensed aromatic carbon (ConAC) content (determined by benzenepolycarboxylic acid (BPCA) markers), and their -OH functional group content (infrared spectroscopy). PFOA sorption isotherms …

Antarctic Polar Stratospheric Cloud Analysis Of Ace-Fts Data From 2005 To 2023, M. Lecours, C. D. Boone, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We present an analysis of Antarctic polar winters from 2005 to 2023 as observed by the Atmospheric Chemistry Experiment (ACE). The unique broad band infrared spectral features in ACE “residual” spectra are used to classify the spectra of polar aerosols by composition into polar stratospheric clouds (PSCs) and sulfate aerosols. The spectra of PSCs are further classified into nitric acid trihydrate, supercooled ternary solutions, supercooled nitric acid, ice-mix, and mixtures of PSCs. A breakdown of PSC composition is presented for each year. Antarctic winter seasons with unusual compositions are: 2011, in which volcanic ash mixed with PSCs was observed from …

Machine-Learning-Enabled Diagnostics With Improved Visualization Of Disease Lesions In Chest X-Ray Images, Md. Fashiar Rahman, Tzu-Liang (Bill) Tseng, Michael Pokojovy, Peter Mccaffrey, Eric Walser, Scott Moen, Alex Vo, Johnny C. Ho

Mathematics & Statistics Faculty Publications

The class activation map (CAM) represents the neural-network-derived region of interest, which can help clarify the mechanism of the convolutional neural network’s determination of any class of interest. In medical imaging, it can help medical practitioners diagnose diseases like COVID-19 or pneumonia by highlighting the suspicious regions in Computational Tomography (CT) or chest X-ray (CXR) film. Many contemporary deep learning techniques only focus on COVID-19 classification tasks using CXRs, while few attempt to make it explainable with a saliency map. To fill this research gap, we first propose a VGG-16-architecture-based deep learning approach in combination with image enhancement, segmentation-based region …

Cumulative Distribution Function And Spatially Resolved Surface-Enhanced Raman Spectroscopy For The Quantitative Analysis Of Emtricitabine, Jana Hrncirova, Marguerite R. Butler, Sucharita Dutta, Meredith R. Clark, John B. Cooper

Chemistry & Biochemistry Faculty Publications

Surface-enhanced Raman spectroscopy (SERS) has exceptional analytical sensitivity and selectivity. However, SERS irreproducibility presents an obstacle when using it for precise quantitative measurements. In this study, colloidal nanoparticles evaporated to dryness are used as a SERS active surface for the detection of the HIV drug emtricitabine (FTC; trade name Emtriva). Despite the irreproducibility of the SERS resulting from the stochastic process of evaporation, using a SERS scanning instrument, the SERS enhancement factors of spatially resolved spectra have a well-defined distribution of signals for a given analyte concentration. This distribution follows a power law function ranging from weak (very abundant signals) …

Role Of Nitrogenous Functional Group Identity In Accelerating 1,2,3- Trichloropropane Degradation By Pyrogenic Carbonaceous Matter (Pcm) And Sulfide Using Pcm-Like Polymers, Han Cao, Jingdong Mao, Paul G. Tratnyek, Wenqing Xu

Chemistry & Biochemistry Faculty Publications

Groundwater contamination by 1,2,3-trichloropropane (TCP) poses a unique challenge due to its human toxicity and recalcitrance to degradation. Previous work suggests that nitrogenous functional groups of pyrogenic carbonaceous matter (PCM), such as biochar, are important in accelerating contaminant dechlorination by sulfide. However, the reaction mechanism is unclear due, in part, to PCM's structural complexity. Herein, PCM-like polymers (PLPs) with controlled placement of nitrogenous functional groups [i.e., quaternary ammonium (QA), pyridine, and pyridinium cations (py⁺)] were employed as model systems to investigate PCM-enhanced TCP degradation by sulfide. Our results suggest that both PLP-QA and PLP-py⁺ were highly effective …

Evaluating The Influence Of Trypanosomiasis On Murine Model Using Corchorus Olitorius Leaf Extract As A Trypanocidal Agent, Fatima M. Madaki, Adamu Y. Kabiru, Ogunrombi D. Clinton, Sakariyau A. Waheed, Yunusa O. Ibrahim

Chemistry & Biochemistry Faculty Publications

Trypanosomiasis, a parasitic disease caused by trypanosomes, which are flagellate protozoa transmitted through the bite of the tsetse fly, manifests with symptoms including substantial weight loss, anemia, fever, edema, adenitis, dermatitis, and nervous disorders. This research investigated the impact of trypanosomiasis on a murine model while utilizing Corchorus olitorius leaf extract as a potential trypanocidal agent. An acute toxicity analysis was conducted following Lorke's method, and the antitrypanosomal efficacy was assessed in rats at doses of 100, 200, and 400 mg/kg over three weeks, monitoring changes in parasitemia count, body weight, and hematological parameters. Additionally, lipid profile, electrolyte concentration, and …

Type-B Energetic Processes: Their Identification And Implications, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

We have now identified two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth. Type-A energy processes, such as classical heat engines, apparently well follow the second law of thermodynamics; Type-B energy processes, such as the newly discovered thermotrophic function that isothermally utilizes environmental heat energy to perform useful work in driving ATP synthesis, follow the first law of thermodynamics (conservation of mass and energy) but do not have to be constrained by the second law, owing to their special asymmetric functions. Several Type-B energy processes such as asymmetric function-gated isothermal electricity production and epicatalysis have …

Examining The Effectiveness Of Oiled Ballast Water Treatment Processes: Insights Into Hydrocarbon Oxidation Product Formation And Environmental Implications, Maxwell L. Harsha, Danielle E. Verna, Yanila Salas-Ortiz, Eduardo Osborn, Eduardo Turcios Valle, Aleksandar I. Goranov, Patrick G. Hatcher, Ana M. Aguilar-Islas, Patrick L. Tomco, David C. Podgorski

Chemistry & Biochemistry Faculty Publications

Ballast water released from ships into coastal environments has been identified as a mechanism that introduces contaminants of concern into coastal ecosystems. This study investigates the treatment processes employed at a ballast water treatment facility in Valdez, Alaska, that remove hydrocarbons from unsegregated ballast water. Specifically, the aim is to quantify and characterize hydrocarbons of emerging concern, known as dissolved hydrocarbon oxidation products (HOPs) and heavy metals (HMs), throughout the treatment process. Specialized analytical techniques were employed, such as non-volatile dissolved organic carbon analysis, fluorescence spectroscopy, Fourier transform-ion cyclotron resonance-mass spectrometry, and inductively coupled plasma triple quadrupole mass spectrometry. Results …

Advancements In The Synthesis Of Polyoxygenated Oxepanes And Thiepanes For Applications To Natural Products, Aditya R. Pote, Shayne M. Weierbach, Mark W. Peczuh, Kyle M. Lambert

Chemistry & Biochemistry Faculty Publications

Oxepanes are central motifs and tenants of many biologically important molecules, and their synthetic construction often presents a challenge to chemists due to consequential entropic and enthalpic barriers that have limited the synthetic toolbox to access these seven-membered oxacycles. This review covers the breadth of synthetic methods to afford the oxepane/thiepane moiety, with a focus on polyoxygenated oxepanes and includes radical cyclizations, Lewis acid-mediated cyclizations, ring closing-metathesis, Nicholas-Ferrier rearrangement, homologations, and ring-expansion strategies. Implementation of these tactics towards sugar-based and non-sugar based (de novo) approaches is presented alongside their extensive application to the total synthesis of several complex polyoxygenated oxepane-containing …

The Ownership Of Potato Boy: A Discussion On Ai And Copyright, James Thibeault

Library Publications

Surprisingly, the copyright status of generative AI works is pretty straight forward in the US: no one owns the copyright. According to the United States Copyright Office (2023), “copyright can protect only material that is the product of human creativity. Most fundamentally, the term ‘author,’ which is used in both the Constitution and the Copyright Act, excludes non-humans.” This concept is not new as previous court cases had already established this ruling. In the 1884 court case Burrow-Giles Lithographic Company v. Sarony, the defendant made copies of a photograph and claimed the author held no copyright since a machine, a …

Sdgs And Circularity In Fashion Industry: Bruneian Perspective Based On Basic Values, Izzah Mohd Noor, Shahid Anjum

ASEAN Journal on Science and Technology for Development

The fashion industry is facing significant textile waste, with millions of textiles ending up in landfills annually. Overconsumption of textiles and clothes due to fast fashion trends has negative environmental impacts. Transitioning to a circular economy is crucial for minimizing environmental impact and addressing the Sustainable Development Goals (SDGs) in the United Nations' 2030 Agenda. This study investigates the adoption of Circular Economy practices and SDGs awareness in second-hand clothing. Using IBM SPSS Statistics Software and Ordinary Least Squares (OLS) regression, the study models consumer behaviors, and attitudes by investigating the influence of four key components from Schwartz's theory of …

Factors Influencing Consumers' Intention To Use Over-The-Top (Ott) Services: A Study In Brunei Darussalam, Hjh Faralisa Hj Zulfikri, Heru Susanto

ASEAN Journal on Science and Technology for Development

The market for over-the-top (OTT) services has witnessed significant growth and transformation, presenting new opportunities and challenges to service providers. This study aims to explore the factors that influence consumers' intention to use OTT services, focusing on the context of Brunei Darussalam. Drawing on the Technology Acceptance Model (TAM) as a theoretical framework, this study investigates the impact of perceived ease of use, perceived usefulness, innovativeness, service quality, information seeking, and entertainment on consumers' intention to use OTT services. A quantitative research approach was adopted and data were collected through an online survey conducted among the general public in Brunei …

The Effects Of Seaweed Farming On Local Ecosystems In The United States, Reid Cohen

Pitzer Senior Theses

In my thesis, I explore how seaweed farming contributes to the regeneration of marine ecosystems, supports biodiversity, and assists in harmful nutrient removal. Seaweed farming is a relatively unexplored industry in the United States with huge carbon capturing potential. Seaweed farming poses a significant opportunity for a project that has the potential to sequester carbon, increase biodiversity, protect coastal ecosystems, naturally clean water, provide biofuel capabilities, substitute as livestock fodder which then decreases methane emissions, along with many more benefits. Kelp supports biodiversity in marine ecosystems and provides essential habitats for various species. The seaweed farming industry holds profound potential …

Numerical Solution Of Hybrid Nanofluid And Its Stability Over Permeable Wedge Sheet With Heat Transfer Analysis, Aisha M. Alqahtani, Zeeshan, Waris Khan, Florentin Smarandache, Nidhal Becheikh, Roobaea Alroobaea, Taseer Muhammad

Branch Mathematics and Statistics Faculty and Staff Publications

The inclusion of nanoparticles has the potential to improve the thermal efficiency of the base fluid. The field of nanofluid (NF) dynamics has attracted important attention due to its extensive range of practical uses like fuel cells, solar energy, medication administration, heat transfer, microfabrication, coolant applications, and other related domains. The aim of this study is to scrutinize the impact of Lorentz force, thermal energy, joule heating, heat source and injection parameters, and Brownian and thermoporetic diffusions on the hybrid nanofluid over the moving wedge. The stability inquiry is reported for the existing work in order to confirm the stable …

Water Quality Contaminants Long-Term Spatial Analysis Along The Upper Clark Fork River Superfund Site Between Warm Springs And Garrison, Montana, Raegan Michele Osentowski

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Long-term data of heavy metal contaminants, cadmium, copper, lead, arsenic, and zinc were compiled from the Montana Department of Environmental Quality, DEQ, and the United States Geological Survey, USGS, to investigate the effects of remediation on water quality along the upper Clark Fork River superfund site. Long-term data sets were analyzed at CFR-03A, CFR-27H, CFR-34, and SS-25 along the upper Clark Fork River and Silver Bow Creek. CFR-03A and CFR-27H had full remediation in the immediate vicinity, SS-25 had on-going remediation in the immediate vicinity, and CFR-34 had no remediation in the immediate vicinity. Analysis of heavy metal contaminants is …

A Data-Driven Machine Learning Approach For Electron-Molecule Ionization Cross Sections, Allison Harris, Josh Nepomuceno

Faculty publications – Physics

Despite their importance in a wide variety of applications, the estimation of ionization cross sections for large molecules continues to present challenges for both experiment and theory. Machine learning (ML) algorithms have been shown to be an effective mechanism for estimating cross section data for atomic targets and a select number of molecular targets. We present an efficient ML model for predicting ionization cross sections for a broad array of molecular targets. Our model is a 3-layer neural network that is trained using published experimental datasets. There is minimal input to the network, making it widely applicable. We show that …

Note On The Spectra Of Steiner Distance Hypermatrices, Joshua Cooper, Zhibin Du

Faculty Publications

The Steiner distance of a set of vertices in a graph is the fewest number of edges in any connected subgraph containing those vertices. The order-k Steiner distance hypermatrix of a graph is the n-dimensional array indexed by vertices, whose entries are the Steiner distances of their corresponding indices. In the case of k = 2, this reduces to the classical distance matrix of a graph. Graham and Pollak showed in 1971 that the determinant of the distance matrix of a tree only depends on its number n of vertices. Here, we show that the hyperdeterminant of the Steiner distance …

121, Scott Brande

All 3D Rock Models

Model 121 - granite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/121-e1e6025763a1493085ee2d9f63c641dd

163, Scott Brande

All 3D Rock Models

Model 163 - bituminous coal - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/163-c2903dfb82bc4f05bf7b3556edf8d4ef

115, Scott Brande

All 3D Rock Models

Model 115 - diorite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/115-298e4710804d4faba714d28c4a80ae78

137, Scott Brande

All 3D Rock Models

Model 137 - rhyolite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/137-8b7ec8ed92fe47559004e87e9aacbb16

167, Scott Brande

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Model 167 - chalk - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/167-1b6dc09a191b4069b0eeae2f9469b77f

164, Scott Brande

All 3D Rock Models

Model 164 - breccia - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/164-6253af9d9ba5431f89204f20b38aa204

162, Scott Brande

All 3D Rock Models

Model 162 - bituminous coal - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/162-135d93a3662248b19017ce280564e780

168, Scott Brande

All 3D Rock Models

Model 168 - chalk - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/168-7a3b2f1e132848378562b32fd2996d26

177, Scott Brande

All 3D Rock Models

Model 177 - conglomerate - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/177-cbc131f6325143dcba1af1c0bf002212

184, Scott Brande

All 3D Rock Models

Model 184 - oolite - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/184-df419a6f77294da7be22a056580b6f81

188, Scott Brande

All 3D Rock Models

Model 188 - sandstone - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/188-5e29c75d2fa340f6a2d0d27ecb44d4ba

194, Scott Brande

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Model 194 - shale - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/194-38eb855877444452be7a0eca7946576f

196, Scott Brande

All 3D Rock Models

Model 196 - travertine - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/196-cd4b91a677cd43ab932ee8b5ca38b38c