Physical Sciences and Mathematics Commons^™

Effects Of Increasing Sintering Pressure On The Performance Of Impregnated Diamond Bit, Yang Zhan, Tan Songcheng, Fang Xiaohong, Yang Kaihua

Coal Geology & Exploration

The matrix formulas of conventional hot-pressed impregnated diamond bits are mostly elemental metal systems, using WC or YG8 as the skeleton materials, Cu alloys as the bonding materials, and Ni, Co, Fe and Mn as the intermediate materials. Due to the compositions and contents of the bonding and skeleton materials in the formulas, the suitable sintering pressure is limited (≤16 MPa), while the sintering temperature is relatively high (≥ 930℃), resulting in a lower relative ratio of the actual and theoretical densities (≤98%) for the diamond bit matrix. However, the high sintering temperature will cause thermal damage to the diamonds, …

Tio2 Crystallization At Room Temperature And Preparation Of Transparent Carbon Counter Electrode For Low-Cost Dye-Sensitized Solar Cells, Muhammad Iqbal Syauqi, Afiten Rahmin Sanjaya, Mohammad Jihad Madiabu, Munawar Khalil, Jarnuzi Gunlazuardi

Makara Journal of Science

We developed a low-cost dye-sensitized solar cell (DSSC) using TiO₂ fabricated via rapid breakdown anodization (RBA) and ultrafast room-temperature crystallization (URTC). The prepared TiO₂ was deposited on a self-made fluorine-doped tin oxide (FTO) conductive glass, and the FTO/TiO₂ system was sensitized using curcumin dye. The DSSC was constructed by sandwiching the FTO/TiO₂/curcumin electrode with an I⁻/I₂ electrolyte and a transparent carbon counter electrode prepared using a liquid–liquid interface system. The characterization results showed that the TiO₂ freshly prepared via URTC was transformed into an anatase crystalline phase, which exhibited a 3.10 …

Application Of Photoacoustic Imaging For Pneumonia Detection, Caesarany Maqfiroh, Rini Widyaningrum, Ahmad Mujtahid Anas, Mitrayana Mitrayana

Makara Journal of Science

We used photoacoustic imaging (PAI) to visualize and compare acoustic intensity levels in pneumonia-affected and healthy chicken lungs. After histological confirmation of pneumonia, the samples were scanned and subjected to a 532-nm diode laser in a photoacoustic imaging system. The acoustic intensity level of pneumonia-affected tissue was examined and compared with that of healthy lung samples. The optimum laser frequency and duty cycle for imaging the samples were 17 kHz and 30%, respectively. The acoustic intensity levels of pneumonia-affected tissue and healthy lungs were −82.5 ± 1.8 dB and −79.9 ± 1.3 dB, respectively. We found that a simple PAI …

Study Of Antioxidant Activity Of The Derivatives Of Quinoline-4-Carboxylic Acids By The Modification Of Isatin Via Pfitzinger Reaction, Sakti Hidayati Fikriya, Antonius Herry Cahyana

Makara Journal of Science

In this study, a quinoline-4-carboxylic acid derivative was synthesized through Pfitzinger reaction. In this reaction, isatin is modified via its reaction with ketone and refluxed for 24 h to obtain quinoline-4-carboxylic acid. The presence of a carboxylic group was identified by Fourier Transform Infrared (FTIR) spectroscopy and ultraviolet–visible (UV-Vis) spectrophotometry. The results showed that the absorption peaks of C=O and O–H stretching’s were detected in the range of 1724–1708 and 3436–3242 cm⁻¹, respectively. In the UV-vis spectrum, a shift in the absorption peak was observed toward a larger wavelength, which is referred as a bathochromic shift. The formation …

Physicochemical Changes And Role Of Analytical Chemistry In Black Garlic (Allium Sativum L.) Processing, Surjani Wonorahardjo, Dian Puspita Sari, Arini Salsabila, Estiyawati Estiyawati, Dewi Yuliani, Anugrah Ricky Wijaya, Suharti Suharti, Irma Kartika Kusumaningrum, Chariztya Anggita Maharani, Thjiong Angelina Noviyanti

Makara Journal of Science

Black garlic is a traditional spice having potential of herbal medicine; however, continuous heating darkens its color and changes its taste due to chemical processes and new equilibrium in the system. In this study, fresh garlic was processed into black garlic at 60 °C for 24 days. Changes in physical and chemical parameters, such as browning and protein content, reducing sugar content, and antioxidative components were recorded. Protein content was measured by Kjeldahl method, brown color development was analyzed using a color reader, reducing sugar was examined using a dinitro salicylic DNS reagent, and antioxidative activities were studied with a …

Equilibrium And Kinetic Studies Of Crude Oil Sorption On Unmodified And Modified Napier Grass, Amalachukwu Ifeyinwa Obi, Vincent Ishmael Ajiwe, Chinwe Priscilla Okonkwo

Makara Journal of Science

Nowadays, natural organic adsorbents are widely used to clean up oil from spills owing to their effectiveness, affordability, and biodegradability. In this study, Napier grass, a widely available agricultural material, was used to remove crude oil from aqueous media. The Napier grass was modified via a mild acetylation process to improve its hydrophobicity. The modification increased the Brunauer–Emmett–Teller surface area of the grass from 180.07 to 271.13 m²/g. Fourier-transform infrared analysis revealed that the modification endowed the originally hydrophilic Napier grass with hydrophobicity. The oil sorption processes were based on monolayer physisorption and controlled by film diffusion. The …

Deep Learning Enhancement And Privacy-Preserving Deep Learning: A Data-Centric Approach, Hung S. Nguyen

USF Tampa Graduate Theses and Dissertations

Deep Learning and its applications have become attractive to a lot of research recentlybecause of its capability to capture important information from large amounts of data. While most of the work focuses on finding the best model parameters, improving machine learning performance from data perspective still needs more attention. In this work, we propose techniques to enhance the robustness of deep learning classification by tackling data issue. Specifically, our data processing proposals aim to alleviate the impacts of class-imbalanced data and non- IID data in deep learning classification and federated learning scenarios. In addition, data pre-processing strategies such that dimensionality …

Measurements Of Jet Multiplicity And Jet Transverse Momentum In Multijet Events In Proton–Proton Collisions At √S = 13tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

Multijet events at large transverse momentum (p_T) are measured at √ s = 13 TeV using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb⁻¹. The multiplicity of jets with p_T > 50 GeV that are produced in association with a high-p_T dijet system is measured in various ranges of the p_T of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δφ1,2 between the two highest p_T jets in the dijet system. The differential production …

Symbiotic Ucyn-A Strains Co-Occurred With El Niño, Relaxed Upwelling, And Varied Eukaryotes Over 10 Years Off Southern California, Colette Fletcher-Hoppe, Yi-Chun Yeh, Yubin Raut, J. L. Weissman, Jed A. Fuhrman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Biological nitrogen fixation, the conversion of N₂ gas into a bioavailable form, is vital to sustaining marine primary production. Studies have shifted beyond traditionally studied tropical diazotrophs. Candidatus Atelocyanobacterium thalassa (or UCYN-A) has emerged as a focal point due to its streamlined metabolism, intimate partnership with a haptophyte host, and broad distribution. Here, we explore the environmental parameters that govern UCYN-A’s presence at the San Pedro Ocean Time-series (SPOT), its host specificity, and statistically significant interactions with non-host eukaryotes from 2008-2018. 16S and 18S rRNA gene sequences were amplified by “universal primers” from monthly samples and resolved into Amplicon …

Beyond The Ice, Nikolaus T. Butz, Joshua Hunter, Emma Fisher

The Journal of Values-Based Leadership

Leadership is a management tool to direct effective achievement of goals. Historical investigation can provide a valuable lens for the study of leadership styles. To that end, this study examines the disparate approaches of Roald Amundsen and Robert Scott as they raced to be the first explorer to reach the South Pole. The objective of this study is to analyze the leadership techniques used in these expeditions, and to determine how they shaped the outcome of each. The process of tacit knowledge and experience coalesce and foster both leadership and action that is not only communication-oriented and value-driven, but also …

Possible Attacks On Match-In-Database Fingerprint Authentication, Jadyn Sondrol

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

Biometrics are used to help keep users’ data private. There are many different biometric systems, all dealing with a unique attribute of a user, such as fingerprint, face, retina, iris and voice recognition. Fingerprint biometric systems, specifically match-in-database, have universally become the most implemented biometric system. To make these systems more secure, threat models are used to identify potential attacks and ways to mitigate them. This paper introduces a threat model for match-in-database fingerprint authentication systems. It also describes some of the most frequent attacks these systems come across and some possible mitigation efforts that can be adapted to keep …

Probing As A Technique To Understand Abstract Spaces, Ashlen A. Plasek

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

Machine learning models, while very powerful, have their operation obfuscated behind millions of parameters. This obfuscation can make deriving a human meaningful process from a machine learning model very difficult. However, while the intermediate states of a machine learning model are similarly obfuscated, using probing, we can start to explore looking at possible structure in those intermediate states. Large language models are a prime example of this obfuscation, and probing can begin to allow novel experimentation to be performed.

Deep-Learning Realtime Upsampling Techniques In Video Games, Biruk Mengistu

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

This paper addresses the challenge of keeping up with the ever-increasing graphical complexity of video games and introduces a deep-learning approach to mitigating it. As games get more and more demanding in terms of their graphics, it becomes increasingly difficult to maintain high-quality images while also ensuring good performance. This is where deep learning super sampling (DLSS) comes in. The paper explains how DLSS works, including the use of convolutional autoencoder neural networks and various other techniques and technologies. It also covers how the network is trained and optimized, as well as how it incorporates temporal antialiasing and frame generation …

Lidar Segmentation-Based Adversarial Attacks On Autonomous Vehicles, Blake Johnson

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

Autonomous vehicles utilizing LiDAR-based 3D perception systems are susceptible to adversarial attacks. This paper focuses on a specific attack scenario that relies on the creation of adversarial point clusters with the intention of fooling the segmentation model utilized by LiDAR into misclassifying point cloud data. This can be translated into the real world with the placement of objects (such as road signs or cardboard) at these adversarial point cluster locations. These locations are generated through an optimization algorithm performed on said adversarial point clusters that are introduced by the attacker.

Not-So-Super Superfund: Cercla’S Biggest Issues, Cameron Berthiaume

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

The Comprehensive Environmental Response, Compensation and Liability Act (CERCLA/Superfund) is a federal law that allows the Environmental Protection Agency (EPA) to clean up contaminated sites and hold the parties responsible for the contamination financially liable. However, CERCLA faces a number of challenges to fulfilling its mission. This report examines some of the biggest issues facing the law in the past and present.

An Introduction To Consumptive Use Of Water In South Carolina, Heather Bergerud Nix, Mani Rouhi Rad

Journal of South Carolina Water Resources

Effective water resource management requires understanding the supply of and the demand for water. In South Carolina, as in other places, water demand is often determined using total withdrawal volumes. However, the volume of water that is withdrawn can be significantly different from the volume that is actually consumed, which becomes unavailable for downstream uses. Water used for energy generation is commonly excluded from evaluations of total withdrawal volume because it is often assumed to be no or low consumptive use, meaning much of the withdrawn water is returned to the source and remains available for downstream uses. Additionally, energy …

Comment On “Search For Explanation Of The Neutron Lifetime Anomaly”, F. E. Wietfeldt, R. Biswas, J. Caylor, Bret E. Crawford, M. S. Dewey, N. Fomin, G. L. Greene, C. C. Haddock, S. F. Hoogerheide, H. P. Mumm, J. S. Nico, W. M. Snow, J. Zuchegno

Physics and Astronomy Faculty Publications

We respond to issues raised by Serebrov et al. in a recent paper regarding systematic effects in the beam neutron lifetime experiment performed at NIST. We show that these effects were considered in the original analyses and that our corrections and systematic uncertainties were appropriate. We point out some misunderstandings in the analysis of Serebrov et al. None of the issues raised lead us to alter the value of the neutron lifetime reported.

Analysis Of Ostds Failure Potential Due To Sea-Level Rise And Other Inundation Factors: An Integrated Geo-Spatial Analysis, Alec Colarusso

USF Tampa Graduate Theses and Dissertations

While many aspects of climate change are well-studied, the vulnerability of Onsite Sewage Treatment and Disposal Systems (OSTDS) to sea-level rise (SLR) has not been thoroughly examined despite the potentially significant environmental impacts, including nutrient and pathogen loading. Research gaps include the need to determine the suitability of models to predict groundwater inundation due to SLR and the consequent impact on OSTDS. As such, this study aims to compare Bathtub/hydrostatic and physics-based/MODFLOW/3D numerical modeling methods of simulating groundwater inundation from SLR to identify OSTDS vulnerability to failure due to a reduction in the height of the vadose zone (saturation or …

Applications In Opioid Analysis With Faims Through Control Of Vapor Phase Solvent Modifiers, Nathan Grimes

USF Tampa Graduate Theses and Dissertations

Field Asymmetric Ion Mobility Spectrometry (FAIMS), often coupled with mass spectrometry (MS), offers rapid analytical ion filtration, useful in reducing matrix interference and differentiating isomeric compounds. This study focuses on augmenting FAIMS-MS analyses through the incorporation of gas phase solvents, or "modifiers," inducing dynamic microsolvation, a particularly potent method of analysis enhancement.

Initially, the research utilized a bubbler-based system, incorporating a humidity sensor, improving modifier concentration control when using water. Our application in opioid detection and differentiation revealed considerable advancements. Notably, an increased peak capacity in an opioid mixture and successful separation of the isobaric opioid pair, alfentanil and ortho-isopropyl …

Optimal Estimation Inversion Of Ionospheric Electron Density From Gnss-Pod Limb Measurements: Part I-Algorithm And Morphology, Dong L. Wu, Nimalan Swarnalingam, Cornelius C. J. H. Salinas, Daniel J. Emmons, Tyler C. Summers, Robert Gardiner-Garden

Faculty Publications

GNSS-LEO radio links from Precise Orbital Determination (POD) and Radio Occultation (RO) antennas have been used increasingly in characterizing the global 3D distribution and variability of ionospheric electron density (Ne). In this study, we developed an optimal estimation (OE) method to retrieve Ne profiles from the slant total electron content (hTEC) measurements acquired by the GNSS-POD links at negative elevation angles (ε < 0°). Although both OE and onion-peeling (OP) methods use the Abel weighting function in the Ne inversion, they are significantly different in terms of performance in the lower ionosphere. The new OE results can overcome the large Ne oscillations, sometimes negative values, seen in the OP retrievals in the E-region ionosphere. In the companion paper in this Special Issue, the HmF2 and NmF2 from the OE retrieval are validated against ground-based ionosondes and radar observations, showing generally good agreements in NmF2 from all sites. Nighttime hmF2 measurements tend to agree better than the daytime when the ionosonde heights tend to be slightly lower. The OE algorithm has been applied to all GNSS-POD data acquired from the COSMIC-1 (2006–2019), COSMIC-2 (2019–present), and Spire (2019–present) constellations, showing a consistent ionospheric Ne morphology. The unprecedented spatiotemporal sampling of the ionosphere from these constellations now allows a detailed analysis of the frequency–wavenumber spectra for the Ne variability at different heights. In the lower ionosphere (~150 km), we found significant spectral power in DE1, DW6, DW4, SW5, and SE4 wave components, in addition to well-known DW1, SW2, and DE3 waves. In the upper ionosphere (~450 km), additional wave components are still present, including DE4, DW4, DW6, SE4, and SW4. The co-existence of eastward- and westward-propagating wave4 components implies the presence of a stationary wave4 (SPW4), as suggested by other earlier studies. Further improvements to the OE method are proposed, including a tomographic inversion technique that leverages the asymmetric sampling about the tangent point associated with GNSS-LEO links.

Observation Of Robust Zero Energy Extended States, Jannatul Ferdous, Cem Yuce, Andrea Alu, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

Topological edge states arise at the interface of two topologically distinct structures and have two distinct features: they are localized and robust against symmetry protecting disorder. On the other hand, conventional transport in one dimension is associated with extended states, which typically do not have topological robustness. In this letter, using lossy coupled resonators in one dimension, we demonstrate both theoretically and experimentally the existence of robust states residing in the bulk. We show that they are unusually robust against disorders in coupling between adjacent sites and losses. Our work paves the way to a different form of robust transport …

Study On Versatile S(Vi) Reagents Towards Synthesis Of S(Iv) And S(Vi) Functional Groups, Shun Teng

USF Tampa Graduate Theses and Dissertations

This dissertation mainly covers the latest methodology development in the field of sulfur-containing functional groups in synthetic chemistry. There are two parts. The first part is the asymmetric synthesis of sulfoximines, sulfonimidamides, sulfonimidoyl fluorides, and sulfinamides enabled by a versatile enantiopure S(VI) reagent. The second part is the Grignard reagent-triggered divergent S-editing synthesis via a bench-stable S(VI) reagent.

In the first part, the asymmetric synthesis of sulfoximines, sulfonimidamides, sulfonimidoyl fluorides, and sulfinamides is reported. This report focuses on the development of a bifunctional S(VI) reagent and its utility in synthesis. It employed the enhanced stability of sulfonimidoyl fluorides and the …

Cauchy-Type Integral Method For Solving The Linearized One-Dimensional Vlasov-Poisson Equation, Frank M. Lee, Bradley A. Shadwick

Department of Physics and Astronomy: Faculty Publications

We present a method for solving the linearized Vlasov-Poisson equation, based on analyticity properties of the equilibrium and initial condition through Cauchy-type integrals, that produces algebraic expressions for the distribution and field, i.e., the solution is expressed without integrals. Standard extant approaches involve deformations of the Bromwich contour that give erroneous results for certain physically reasonable configurations or eigenfunction expansions that are misleading as to the temporal structure of the solution. Our method is more transparent, lacks these defects, and predicts previously unrecognized behavior.

Research On Stability Of Rock Mass And +30 Level Surface Construction Works When Re-Exploiting The Seam H10 At Mong Duong Coal Mine, Vietnam, Tien Trung Vu, Doan Viet Dao

Journal of Sustainable Mining

The re-exploitation of coal seams located near the ground is one of the solutions to increase output, reduce mining investment costs, and avoid wasting coal resources. The re-exploitation of coal seams will also cause instability of the surrounding rock mass and may affect surface construction works. Through the process of re-exploiting the longwall in seam H10 at Mong Duong Coal Mine, the authors have studied and evaluated the stability of the rock mass and +30 level surface works (including fan station and gateroad). To achieve the results in this study, the numerical simulation model method and the analytical method were …

Multiplication Operators By White Noise Delta Functions And Associated Differential Equations, Luigi Accardi, Un Cig Ji, Kimiaki Saitô

Journal of Stochastic Analysis

No abstract provided.

Evaluating The Post-Mining Land Uses Of Former Mine Sites For Sustainable Purposes In South Africa, Sphiwe E Mhlongo

Journal of Sustainable Mining

This paper uses a case study of an abandoned magnesite mine in the Limpopo Province of South Africa to find ways of identifying post-mining land used from the current uses of the abandoned mine sites or features. The approach used involved carrying out a field characterization of the mine site and documentation of the current uses of the features of the abandoned mine site. The technique used to identify the internal and external factors of the land uses involved analyzing their Strength, Weakness, Opportunities, and Threats. The Analytic Hierarchy Process (AHP) technique was used for further ranking of the land …

Effect Of Ag2o Nanosheets Thickness On The Performance Of Al/Geo2/Ag2o/Geo2/C Multifunctional Electronic Devices, Atef Fayez Qasrawi Prof. Dr., Hazem Kh Khanfar Prof. Dr.

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

Herein, stacked layers of germanium oxide comprising silver oxide nanosheets are used to fabricate multifunctional electronic devices. The performance of these devices is enhanced by altering the thickness of Ag2O nanosheets. The effect of

Ag2O nanosheets on the electronic performance of stacked layers of GeO2 is reported. The three stacked layers (GeO2/Ag2O/GeO2; named GAG) which are coated onto Al substrates under a vacuum pressure of 10-5 mbar are subjected to measurements by X-ray diffraction, X-ray photoelectron, X-ray fluorescence, impedance spectroscopy, capacitance –voltage and current-voltage characteristics techniques. The impedance spectroscopy analysis indicates that altering the thickness of the Ag2O layer in …

Identify The Most Productive Crop To Encourage Sustainable Farming Methods In Smart Farming Using Neutrosophic Environment, Ahmed Abdelhafeez, Hadeer Mahmoud, Alber S. Aziz

Neutrosophic Systems with Applications

Only with careful management can the data provided by crops be used to make smart, profitable choices. Data has become the central ingredient in contemporary agriculture, and the recent advancements in handling it are contributing greatly to the meteoric rise of smart farming. Gains in efficiency and longevity may be realized to a significant degree by using the objective data collected by sensors. These data-driven farms can maximize output while minimizing waste and environmental impact thanks to the information they collect and analyze. Various criteria and factors in smart farming can aid in productivity. Sensors, drones, Global Positioning System (GPS) …

Reconstructing Historical Earthquake-Induced Tsunamis: Case Study Of 1852 Event Using The Adjoint Method Combined With Hmc, Chelsey Noorda

Theses and Dissertations

Seismic hazard analysis aims to estimate human risk due to natural disasters such as earthquakes. To improve seismic hazard analysis, our group is focused on earthquake induced tsunamis and the use of statistical models to reconstruct historical earthquakes. Based on the estimated wave heights given in anecdotal historical descriptions, we created observational probability distributions to model the historically recorded observations and constructed a prior distribution on the relevant earthquake parameters based on known seismicity of a given region. Then we used the software package GeoClaw, and a Metropolis-Hastings sampler to obtain a posterior distribution of earthquake parameters that most closely …

2023 June 22 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.