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Articles 16111 - 16140 of 302422

Full-Text Articles in Physical Sciences and Mathematics

Feasibility Study Of Nature Source In-Seam Exploration, Hu Ze’An, Cao Lingkai, Liu Qinjie, Ji Guangzhong, Xi Chaoqiang, Wu Rongxin Mar 2023

Feasibility Study Of Nature Source In-Seam Exploration, Hu Ze’An, Cao Lingkai, Liu Qinjie, Ji Guangzhong, Xi Chaoqiang, Wu Rongxin

Coal Geology & Exploration

The conventional explosive seismic sources are very tightly controlled in high-gas mine, and a novel non-explosive channel wave method is urgently needed as an alternative. Therefore through the theoretical analysis and numerical simulation experiments, we demostrated that the coal seam satisfied the geophysical conditions to develop the nature source in-seam wave. The time-domain numerical simulation experiment of the passive source channel wave was successfully realized by constructing the nature source in-seam wave model with three stochastic terms, including the stochastic spatial position, stochastic initial excitation time and stochastic amplitude of seismic source. We performed frequency dispersion spectrum calculation on the …


Forward Modeling Of Radio-Magnetotelluric Method Based On Julia Acceleration And Study On Effect Of Displacement Current, Mei Zhuxu, Yuan Yuan, Zhou Feng, Zhou Cong, Zhang Lincheng Mar 2023

Forward Modeling Of Radio-Magnetotelluric Method Based On Julia Acceleration And Study On Effect Of Displacement Current, Mei Zhuxu, Yuan Yuan, Zhou Feng, Zhou Cong, Zhang Lincheng

Coal Geology & Exploration

Radio-magnetotelluric method (RMT) is one of the important tools for shallow surface electromagnetic exploration. Since the exploration frequency band is 10‒300 kHz, the propagation of electromagnetic fields is greatly affected by the dielectric permittivity of the earth. The electromagnetic response calculated with traditional quasi-static conditions severely restricts the accuracy of RMT forward modeling and further affects the resolution of the inversion imaging. In response to this problem, a numerical simulation method of full-current RMT electromagnetic response based on Julia parallel acceleration was proposed. Then, the calculation of each frequency point was sent through the distributed computing in Julia to different …


Development Of Storage Equipment Of Continuous Cable Pipe For Borehole Rescue, Gao Ke, Niu Xin, Zhao Yan, Qin Xiaolin, Lyu Xiaoshu, Xie Xiaobo Mar 2023

Development Of Storage Equipment Of Continuous Cable Pipe For Borehole Rescue, Gao Ke, Niu Xin, Zhao Yan, Qin Xiaolin, Lyu Xiaoshu, Xie Xiaobo

Coal Geology & Exploration

The double-bit bionic self-balancing continuous drilling technology has the advantages including requiring no drilling rig, high drilling speed and slight disturbance to the borehole wall. It is one of the key potential technologies for constructing the security and rescue passages against mine disasters. In this technology, as there are passages for power supply, signal, chip removal and other aspects that are built in the continuous cable pipe, it is required that there shall be no such interference, extrusion or arrangement of dynamic/static conductive electric conduction link as in using the existing drum hoist to store continuous pipes during storage. Therefore, …


Research On Control System Of Drill Pipe Conveying Device Based On Fuzzy Particle Swarm Optimization, Zhang Ning, Liu Qi, Shao Junjie, Chang Jianghua, Luo Pengping, Zou Zujie Mar 2023

Research On Control System Of Drill Pipe Conveying Device Based On Fuzzy Particle Swarm Optimization, Zhang Ning, Liu Qi, Shao Junjie, Chang Jianghua, Luo Pengping, Zou Zujie

Coal Geology & Exploration

In the tripping operation of large-diameter rescue well construction, the drill pipe conveying device used for large-diameter drilling tool transportation and drill string connection. In view of the problem that it is difficult to quickly and accurately lift the drill pipe to the angle of power head for make-up due to its easy vibration in the process of positioning, the structural characteristics and working principle of the drill pipe conveying device were analyzed at first. The kinematic model for the lifting of drill pipe was deduced with the structural relationship, obtaining the mapping relationship in the motion law of the …


A Fault Diagnosis Method Of Rescue Lifting Vehicle Based On Spectral Clustering, Li Lijing, Chang Dashuai, Li Lei, Chai Junfei Mar 2023

A Fault Diagnosis Method Of Rescue Lifting Vehicle Based On Spectral Clustering, Li Lijing, Chang Dashuai, Li Lei, Chai Junfei

Coal Geology & Exploration

In allusion to the characteristics of complex structure of rescue lifting vehicle, the poor independence of working condition and fault data, and the difficulty in fault diagnosis, we proposed a fault diagnosis algorithm of rescue lifting vehicle with the semi-supervised support vector machine in this paper. In the algorithm, the information on hidden features of the original fault data was mined with the idea of spectral clustering, to effectively distinguish the independent structural features of the fault information in the component system with different degrees of coupling. Firstly, a fault map was established based on the original input data. Then, …


Recent Research Progresses Of Solid-State Lithium-Sulfur Batteries, Yu Luo, Ru-Qin Ma, Zheng-Liang Gong, Yong Yang Mar 2023

Recent Research Progresses Of Solid-State Lithium-Sulfur Batteries, Yu Luo, Ru-Qin Ma, Zheng-Liang Gong, Yong Yang

Journal of Electrochemistry

All solid-state lithium-sulfur batteries (ASSLSBs) are considered to be one of the most promising next-generation energy storage systems, due to the promises of high energy density and safety. Although the use of solid-state electrolytes could effectively suppress the "shuttle effect" and self-discharge of the conventional liquid lithium-sulfur (Li-S) battery, the commercialization of ASSLSBs has been seriously hampered by the electrolyte degradation, electrode/electrolyte interfacial deterioration, electrochemo-mechanical failure, lithium dendrite growth and electrode pulverization, etc. This paper provides a comprehensive review of recent research progresses on the solid-state electrolytes, sulfur-containing composite cathodes, lithium metal and lithium alloy anodes, and electrode/electrolyte interfaces in …


Coni-Based Bimetal-Organic Framework Derived Carbon Composites Multifunctionally Modified Separators For Lithium-Sulfur Batteries, Yan-Jie Wang, Hong-Yu Cheng, Ji-Yue Hou, Wen-Hao Yang, Rong-Wei Huang, Zhi-Cong Ni, Zi-Yi Zhu, Ying Wang, Ke-Yi Wei, Yi-Yong Zhang, Xue Li Mar 2023

Coni-Based Bimetal-Organic Framework Derived Carbon Composites Multifunctionally Modified Separators For Lithium-Sulfur Batteries, Yan-Jie Wang, Hong-Yu Cheng, Ji-Yue Hou, Wen-Hao Yang, Rong-Wei Huang, Zhi-Cong Ni, Zi-Yi Zhu, Ying Wang, Ke-Yi Wei, Yi-Yong Zhang, Xue Li

Journal of Electrochemistry

The commercial application of lithium-sulfur batteries (LSB) is still limited by the irreversible capacity fading caused by the shuttle of lithium polysulfides (LIPS). To address this issue, a bimetal (nickel, cobalt)-organic framework (MOF) derived carbon, (Ni, Co)/C, was prepared to modify the separator. The multifunctionally modified separator effectively captures LIPS, ensuring the stability and reversibility of sulfur fixation, while providing catalytic activity and improving ionic conductivity. The cobalt metal has a larger coordination number, more pore structure distribution, larger specific surface area, more surface C=O, and smaller particle size to achieve a large and rapid chemical sulfur fixation. The high …


Preface To The Special Issue On Lithium-Sulfur Batteries, Jia-Jia Chen, Ren-Jie Chen, Zhong Jin Mar 2023

Preface To The Special Issue On Lithium-Sulfur Batteries, Jia-Jia Chen, Ren-Jie Chen, Zhong Jin

Journal of Electrochemistry

No abstract provided.


Final 2021 Unreclaimed Sites Sampling Ur-40 Site Evaluation Summary Report, Pioneer Technical Services, Inc. Mar 2023

Final 2021 Unreclaimed Sites Sampling Ur-40 Site Evaluation Summary Report, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Bimetallic Compound Catalysts With Multiple Active Centers For Accelerated Polysulfide Conversion In Li-S Batteries, Wu-Xing Hua, Jing-Yi Xia, Zhong-Hao Hu, Huan Li, Wei Lv, Quan-Hong Yang Mar 2023

Bimetallic Compound Catalysts With Multiple Active Centers For Accelerated Polysulfide Conversion In Li-S Batteries, Wu-Xing Hua, Jing-Yi Xia, Zhong-Hao Hu, Huan Li, Wei Lv, Quan-Hong Yang

Journal of Electrochemistry

Practical applications of lithium-sulfur (Li-S) batteries are hindered mainly by the low sulfur utilization and severe capacity fading derived from the polysulfide shuttling. Catalysis is an effective remedy to those problems by promoting the conversion of polysulfides to reduce their accumulation in the electrolyte, which needs the catalyst to have efficient adsorption ability to soluble polysulfides and high activity for their conversion. In this work, we have proposed a bimetallic compound of NiCo2S4 anchored onto sulfur-doped graphene (NCS@SG) to fabricate a catalytic interlayer for Li-S batteries. Compared to CoS, the NiCo2S4 demonstrated much higher …


Transport Effects In Non-Hermitian Nonreciprocal Systems: General Approach, Hamed Ghaemi-Dizicheh Mar 2023

Transport Effects In Non-Hermitian Nonreciprocal Systems: General Approach, Hamed Ghaemi-Dizicheh

Physics and Astronomy Faculty Publications and Presentations

In this paper, we present a unifying analytical framework for identifying conditions for transport effects such as reflectionless and transparent transport, lasing, and coherent perfect absorption in non-Hermitian nonreciprocal systems using a generalized transfer matrix method. This provides a universal approach to studying the transport of tight-binding platforms, including higher-dimensional models and those with an internal degree of freedom going beyond the previously studied case of one-dimensional chains with nearest-neighbor couplings. For a specific class of tight-binding models, the relevant transport conditions and their signatures of non-Hermitian, nonreciprocal, and topological behavior are analytically tractable from a general perspective. We investigate …


Trait-Based Assembly Of Arbuscular Mycorrhizal Fungal Communities Determines Soil Carbon Formation And Retention, Caitlyn C. A. Horsch, Pedro M. Antunes, Catherine Fahey, A. Stuart Grandy, Cynthia M. Kallenbach Mar 2023

Trait-Based Assembly Of Arbuscular Mycorrhizal Fungal Communities Determines Soil Carbon Formation And Retention, Caitlyn C. A. Horsch, Pedro M. Antunes, Catherine Fahey, A. Stuart Grandy, Cynthia M. Kallenbach

Faculty Publications

Fungi are crucial for soil organic carbon (SOC) formation, especially for the more persistent mineral-associated organic C (MAOC) pool. Yet, evidence for this often overlooks arbuscular mycorrhizal fungi (AMF) communities and how their composition and traits impact SOC accumulation.

We grew sudangrass with AMF communities representing different traits conserved at the family level: competitors, from the Gigasporaceae family; ruderals, from the Glomeraceae family; or both families combined. We labeled sudangrass with 13C-CO2 to assess AMF contributions to SOC, impacts on SOC priming, and fungal biomass persistence in MAOC.

Single-family AMF communities decreased total SOC by 13.8%, likely due to fungal …


Body Dimension And Length-Weigh Relationships Of Invasive Exotic Earthworm Species In Huron Mountains Forests, Paula Arroyo, Xiaoyong Chen, Timothy Gsell, John A. Yunger, Mary E. Carrington Mar 2023

Body Dimension And Length-Weigh Relationships Of Invasive Exotic Earthworm Species In Huron Mountains Forests, Paula Arroyo, Xiaoyong Chen, Timothy Gsell, John A. Yunger, Mary E. Carrington

Research Days

Invasive exotic earthworms have undesired ecological effects on structure, function, and biodiversity of forest ecosystems in the Great Lakes region. Biological parameters including body length, weight, growth rate, and regeneration patterns of earthworms are necessary to understand their life cycle and impacts on ecological processes such as nutrient biogeochemistry cycling and carbon sequestration in the forests, as well as for forest management practices. In this work, earthworms were surveyed in main forest types of the Huron Mountains Preserve of Michigan, Upper Peninsula during the period of May 2021 to October 2022. Earthworms were captured from established sampling quadrates using a …


Citation Polarity Identification From Scientific Articles Using Deep Learning Methods, Souvik Kundu Mar 2023

Citation Polarity Identification From Scientific Articles Using Deep Learning Methods, Souvik Kundu

Electronic Thesis and Dissertation Repository

The way in which research articles are cited reflects how previous work is utilized by other researchers or stakeholders and can indicate the impact of that work on subsequent experiments. Based on human intuition, citations can be perceived as positive, negative, or neutral. While current citation indexing systems provide information on the author and publication name of the cited article, as well as the citation count, they do not indicate the polarity of the citation. This study aims to identify the polarity of citations in scientific research articles using pre-trained language models like BERT, ELECTRA, RoBERTa, Bio-RoBERTa, SPECTER, ERNIE, LongFormer, …


Electric Utility Performance In The Mountain West, Hira Ahmed, Miguel Soriano Ralston, Caitlin J. Saladino, William E. Brown Jr. Mar 2023

Electric Utility Performance In The Mountain West, Hira Ahmed, Miguel Soriano Ralston, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet examines select data from the Citizens Utility Board (CUB) report, “Electric Utility Performance: A State-By-State Review,” which provides information on the affordability, reliability, and environmental responsibility of electric utility energy consumption. The original report provides a comprehensive state-by-state profile of utility performance in the United States. These data were originally reported by the Energy Information Administration (EIA) of the U.S. Department of Energy. This federal entity is responsible for the aggregation and dissemination of information about the American energy industry. This fact sheet highlights energy sources, affordability, reliability, and environmental impact of energy consumption in the Mountain …


Regular Solutions To Elliptic Equations, Alfonso Castro, Jon T. Jacobsen Mar 2023

Regular Solutions To Elliptic Equations, Alfonso Castro, Jon T. Jacobsen

All HMC Faculty Publications and Research

A review of results and techniques on the existence of regular radial solutions to second order elliptic boundary value problems driven by linear and quasilinear operators is presented. Of particular interest are results where the solvability of a given elliptic problem can be analyzed by the relationship between the spectrum of the operator and the behavior of the nonlinearity near infinity and at zero. Energy arguments and Pohozaev type identities are used extensively in that analysis. An appendix with a proof of the contraction mapping principle best suited for using continuous dependence to ordinary differential equations on initial conditions is …


Using Satellites To Map The Urban Heat Island Effect And Using Products To Generate Public Action In Harrisonburg, Trevor Brooks, Timothy A. Kreps Mar 2023

Using Satellites To Map The Urban Heat Island Effect And Using Products To Generate Public Action In Harrisonburg, Trevor Brooks, Timothy A. Kreps

ASPIRE 2023

The Urban Heat Island effect (UHI) is a phenomenon where urban centers are hotter than their surrounding rural counterparts. Ever since it was first discovered there have been a variety of methods of mapping this effect from using terrestrial sensors to satellites. This study attempts to evaluate different mapping methods, specifically two different satellite methods (ECOSTRESS and MODIS). As well as a community driven mapping method that involved terrestrial sensors attached to cars. This study then discusses remedies to the UHI and documents efforts to remedy it through a partnership between researchers, the community, and the city of Harrisonburg as …


Off-Shell Effects In Bound Nucleons And Parton Distributions From 1H, 2H, 3H, And 3He Data, S. I. Alekhin, S. A. Kulagin, Roberto Petti Mar 2023

Off-Shell Effects In Bound Nucleons And Parton Distributions From 1H, 2H, 3H, And 3He Data, S. I. Alekhin, S. A. Kulagin, Roberto Petti

Faculty Publications

We report the results of a new global QCD analysis including deep-inelastic scattering data off 1H, 2H, 3H, and 3He targets. Nuclear corrections are treated in terms of a nuclear convolution approach with off-shell bound nucleons. The off-shell (OS) corrections responsible for the modification of the structure functions (SFs) of bound nucleons are constrained in a global fit along with the proton parton distribution functions (PDFs) and the higher-twist (HT) terms. We investigate the proton-neutron difference for the OS correction and discuss our predictions for the SF ratio F n 2 / F p 2 and …


Hörmander’S L2 -Method, ∂-Problem And Polyanalytic Function Theory In One Complex Variable, Daniel Alpay, Fabrizio Colombo, Kamal Diki, Irene Sabadini, Daniele C. Struppa Mar 2023

Hörmander’S L2 -Method, ∂-Problem And Polyanalytic Function Theory In One Complex Variable, Daniel Alpay, Fabrizio Colombo, Kamal Diki, Irene Sabadini, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we consider the classical ∂-problem in the case of one complex variable both for analytic and polyanalytic data. We apply the decomposition property of polyanalytic functions in order to construct particular solutions of this problem and obtain new Hörmander type estimates using suitable powers of the Cauchy-Riemann operator. We also compute particular solutions of the ∂-problem for specific polyanalytic data such as the Itô complex Hermite polynomials and polyanalytic Fock kernels.


Cardiac Arrhythmia Disease Classifier Model Based On A Fuzzy Fusion Approach, Fatma Taher, Hamoud Alshammari, Lobna Osman, Mohamed Elhoseny, Abdulaziz Shehab, Eman Elayat Mar 2023

Cardiac Arrhythmia Disease Classifier Model Based On A Fuzzy Fusion Approach, Fatma Taher, Hamoud Alshammari, Lobna Osman, Mohamed Elhoseny, Abdulaziz Shehab, Eman Elayat

All Works

Cardiac diseases are one of the greatest global health challenges. Due to the high annual mortality rates, cardiac diseases have attracted the attention of numerous researchers in recent years. This article proposes a hybrid fuzzy fusion classification model for cardiac arrhythmia diseases. The fusion model is utilized to optimally select the highest-ranked features generated by a variety of well-known feature-selection algorithms. An ensemble of classifiers is then applied to the fusion’s results. The proposed model classifies the arrhythmia dataset from the University of California, Irvine into normal/abnormal classes as well as 16 classes of arrhythmia. Initially, at the preprocessing steps, …


2021 Particle Grain-Size And Total Organic Content Analyses Of Surface Sediments From Puget Sound And Elliott Bay Near Seattle, Wa, Ethan Hoang Mar 2023

2021 Particle Grain-Size And Total Organic Content Analyses Of Surface Sediments From Puget Sound And Elliott Bay Near Seattle, Wa, Ethan Hoang

Environmental Science Undergraduate Theses

Seattle’s Elliott Bay has been a particularly intriguing area in regards to anthropological activities and their effects on the surrounding environment. The construction of the city brought about the displacement of sediment around the bay, resulting in lower quality sediments that negatively impact the nutrient cycles in the benthic zone. This project’s examination of total organic carbon and particle size in sediment serves as a baseline to which scientists can refer in monitoring future sediment health. To determine this baseline, UW Tacoma obtained sediment samples from Washington State Department of Ecology’s Puget Sound Ecosystem Monitoring Program. The samples were analyzed …


Conformational Dynamics And Free Energy Studies Of Dna And Other Biomolecules, Paul B. Orndorff Mar 2023

Conformational Dynamics And Free Energy Studies Of Dna And Other Biomolecules, Paul B. Orndorff

USF Tampa Graduate Theses and Dissertations

This work uses molecular dynamics simulations and enhanced sampling methods to investigate both the qualitative and quantitative properties of biomolecular systems. Conformational dynamics are critical in the study of biomolecular systems. Application of computer simulations to study dynamics of biomolecular systems allows for motions to be readily investigated at a resolution not possible in experimental techniques. In this work, the dynamics of uracil damaged and undamaged DNA is studied via molecular dynamics simulations. Uracil results in DNA from either misincorporation in the replication process or through spontaneous deamination of cytosine, and its presence in DNA can lead to mutations in …


Measurement Of The Double-Differential Muon-Neutrino Charged-Current Inclusive Cross Section In The Nova Near Detector, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, B. Behera, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, Roberto Petti, Et. Al. Mar 2023

Measurement Of The Double-Differential Muon-Neutrino Charged-Current Inclusive Cross Section In The Nova Near Detector, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, B. Behera, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, Roberto Petti, Et. Al.

Faculty Publications

We report cross-section measurements of the final-state muon kinematics for νμ charged-current interactions in the NOvA near detector using an accumulated 8.09×1020 protons on target in the NuMI beam. We present the results as a double-differential cross section in the observed outgoing muon energy and angle, as well as single-differential cross sections in the derived neutrino energy, Eν, and square of the four-momentum transfer, Q2. We compare the results to inclusive cross-section predictions from various neutrino event generators via χ2 calculations using a covariance matrix that accounts for bin-to-bin correlations of systematic uncertainties. …


Multi-Scale Hybridized Topic Modeling: A Pipeline For Analyzing Unstructured Text Datasets Via Topic Modeling, Keyi Cheng, Stefan Inzer, Adrian Leung, Xiaoxian Shen, Deanna Needell, Todd Presner, Michael Perlmutter, Michael R. Lindstrom, Joyce Chew Mar 2023

Multi-Scale Hybridized Topic Modeling: A Pipeline For Analyzing Unstructured Text Datasets Via Topic Modeling, Keyi Cheng, Stefan Inzer, Adrian Leung, Xiaoxian Shen, Deanna Needell, Todd Presner, Michael Perlmutter, Michael R. Lindstrom, Joyce Chew

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We propose a multi-scale hybridized topic modeling method to find hidden topics from transcribed interviews more accurately and more efficiently than traditional topic modeling methods. Our multiscale hybridized topic modeling method (MSHTM) approaches data at different scales and performs topic modeling in a hierarchical way utilizing first a classical method, Nonnegative Matrix Factorization, and then a transformer-based method, BERTopic. It harnesses the strengths of both NMF and BERTopic. Our method can help researchers and the public better extract and interpret the interview information. Additionally, it provides insights for new indexing systems based on the topic level. We then deploy our …


Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji Mar 2023

Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji

Hadhramout University Journal of Natural & Applied Sciences

In this research, two new azo dyes, 9-(2-Hydroxy-ethoxymethyl)-2-(2-hydroxy5nitrophenylazo)-1,9-dihydro-purin-6-one and 4-(2-Hydroxy-napHthalen-1-ylazo)-N-(5-methyl-isoxazol-3-yl)-benzenesulfonamide, derived from Acyclovir and Sulfamethoxazole was synthesized. The first dye synthesis was started by diazation of acyclovir, then combined with 4-nitrophenol activated with potassium hydroxide 10%, yielding 80%, and its purity was verified by thin layer chromatography (TLC). The second dye synthesis was started by diazation of Sulfamethoxazole then combined with β-naphthol activated with potassium hydroxide 10%, yielding 87%, and its purity was verified by thin layer chromatography (TLC). The identity of the resulting pigments was determined based on spectroscopic methods such as infrared spectroscopy, proton nuclear magnetic resonance spectrum …


Margalefidinium Polykrikoides Cyst Resuspension In The Lafayette River, A Sub-Tributary Of The Chesapeake Bay, Gabrielle Greaney, Eduardo Perez Vega, Katherine Crider, Dreux Chappell, Kimberly Powell, Richard Hale, Peter Bernhardt, Margaret Mulholland Mar 2023

Margalefidinium Polykrikoides Cyst Resuspension In The Lafayette River, A Sub-Tributary Of The Chesapeake Bay, Gabrielle Greaney, Eduardo Perez Vega, Katherine Crider, Dreux Chappell, Kimberly Powell, Richard Hale, Peter Bernhardt, Margaret Mulholland

Undergraduate Research Symposium

Harmful Algal Blooms are a collection of algae in a body of water that can cause serious environmental issues and health problems in both people and aquatic organisms. Dinoflagellates are microscopic, unicellular, and eukaryotic organisms that are well known for forming harmful algal blooms because of eutrophication. Coastal Virginia suffers from HABs in the Chesapeake Bay and its tributaries. A common species of dinoflagellate, known as Margalefidinium polykrikoides exists in the Chesapeake Bay. The purpose of this study is to determine if sediment resuspension produced by wind generated surface gravity waves cause cysts (dinoflagellate resting stages) to be suspended into …


Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder Mar 2023

Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder

Undergraduate Research Symposium

Triple-negative breast cancer (TNBC) is one of the most aggressive and challenging breast cancer subtypes to treat, as these cancer cells lack three common receptors: estrogen, progesterone, and human epidermal growth factor receptor 2. The multiple oxidation states transition metals can occupy have made this narrowly explored group popular for anti-cancer research in recent decades. Furthermore, the success of cisplatin, which has platinum as a metal center, while being a cancer-fighting agent with serious side effects, has caused other metal centers to be investigated as possible alternatives as chemotherapeutic drugs. Copper, as a biologically essential metal, makes an attractive candidate …


Potential Effect Of Phlorotannins In Brown Algae For Antidiabetic Therapy: Molecular Docking Approach, Melani Sinastri Renagupita, Rahadianto Rahadianto, Efyluk Garianto, Herin Setianingsih Mar 2023

Potential Effect Of Phlorotannins In Brown Algae For Antidiabetic Therapy: Molecular Docking Approach, Melani Sinastri Renagupita, Rahadianto Rahadianto, Efyluk Garianto, Herin Setianingsih

Makara Journal of Science

This study aims to manifest the effect of the active compound phlorotannins in brown algae on decreasing insulin resistance by analyzing the predicted interaction between phlorotannins and protein tyrosine phosphatase 1B (PTP 1B) and estimating the pharmacokinetics and toxicity of the active compound for type 2 diabetes mellitus (DM) therapy. This type of research uses an in silico study to test the effect of using phlorotannins as an active compound in brown algae against PTP 1B inhibition. Starting from preparing materials, i.e., downloading the three-dimensional structure of phlorotannins via PubChem and PTP 1B via RSCB PDB (PDB 1A5Y), molecular docking …


Modification Of Zeolite Made From Coal Fly Ash With Tio2: Effect Of Aging Time On Physical And Optical Properties, Linda Jati Kusumawardani, Ani Iryani, Ennita Lusiana Sinaga Mar 2023

Modification Of Zeolite Made From Coal Fly Ash With Tio2: Effect Of Aging Time On Physical And Optical Properties, Linda Jati Kusumawardani, Ani Iryani, Ennita Lusiana Sinaga

Makara Journal of Science

The high levels of metal oxides, SiO2, and Al2O3 give coal fly ash the potential for development into zeolite. Zeolite was prepared from fly ash by combining alkaline fusion with hydrothermal treatment. Using this method results in a high surface area, high mechanical properties, and high crystallinity of the sample. Zeolite as a product is modified by TiO2. This study was intended to determine the effect of the operating process in zeolite synthesis from coal fly ash on the types and properties of zeolite and the effect of the aging time of TiO …


Carbon Dioxide-Induced Corrosion Of Aisi 4140 Steel In Acidified Artificial Geothermal Brine, Anawati Anawati, Rayhan Izzat, Riene Kaelamanda Pragitta, Rafli Ihsan Hernandi Mar 2023

Carbon Dioxide-Induced Corrosion Of Aisi 4140 Steel In Acidified Artificial Geothermal Brine, Anawati Anawati, Rayhan Izzat, Riene Kaelamanda Pragitta, Rafli Ihsan Hernandi

Makara Journal of Science

Carbon dioxide (CO2)-induced corrosion often occurs in the structural materials of geothermal industry. The presence of CO2 influences the formation of various corrosion products. This research investigates the effect of dissolved CO2 in acidic brines on the corrosion behavior of AISI 4140 steel at atmospheric pressure. The brines were the standard brine, Ca-free brine, and high-salinity brine. The corrosion behavior was studied using electrochemical and immersion tests. A cyclic polarization test showed that the corrosion rate was higher in dissolved CO2 brine than in non-CO2 brine, and an immersion test demonstrated a similar result. …