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Michigan Technological University

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Articles 31 - 60 of 1253

Full-Text Articles in Physical Sciences and Mathematics

Constraints On Metastable Superheavy Dark Matter Coupled To Sterile Neutrinos With The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, K. Nguyen, D. Nitz, Et Al. Apr 2024

Constraints On Metastable Superheavy Dark Matter Coupled To Sterile Neutrinos With The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, K. Nguyen, D. Nitz, Et Al.

Michigan Tech Publications, Part 2

Dark matter particles could be superheavy, provided their lifetime is much longer than the age of the Universe. Using the sensitivity of the Pierre Auger Observatory to ultrahigh energy neutrinos and photons, we constrain a specific extension of the Standard Model of particle physics that meets the lifetime requirement for a superheavy particle by coupling it to a sector of ultralight sterile neutrinos. Our results show that, for a typical dark coupling constant of 0.1, the mixing angle θm between active and sterile neutrinos must satisfy, roughly, θm≲1.5×10-6(MX/109 GeV)-2 for a mass MX of the dark-matter particle between 108 GeV …

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Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger Apr 2024

Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger

Michigan Tech Publications, Part 2

The ethylene-forming enzyme (EFE) is an Fe(II), 2-oxoglutarate (2OG), and l-arginine (l-Arg)-dependent oxygenase that either forms ethylene and three CO2/bicarbonate from 2OG or couples the decarboxylation of 2OG to C5 hydroxylation of l-Arg. l-Arg binds with C5 toward the metal center, causing 2OG to change from monodentate to chelate metal interaction and OD1 to OD2 switch of D191 metal coordination. We applied anaerobic UV-visible spectroscopy, X-ray crystallography, and computational approaches to three EFE systems with high-resolution structures. The ineffective l-Arg analogue l-canavanine binds to the EFE with O5 pointing away from the metal center while promoting chelate formation by 2OG …

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Estimating Polarization Purity With Noise, Alex Kostinski, Dan Kestner, Jothiram Vivekanandan Mar 2024

Estimating Polarization Purity With Noise, Alex Kostinski, Dan Kestner, Jothiram Vivekanandan

Michigan Tech Publications, Part 2

We formulate a problem of estimating and monitoring mismatch (unwanted departure from orthogonality) of two ostensibly orthogonal polarization channels in a fully polarimetric general device such as a polarimetric weather radar. A statistical approach is proposed by using thermal noise or, more generally, a 'polarimetric noise' class of sources. The suitable noise class of distributions is shown to be rooted in the complex multivariate Gaussian probability density function (pdf), the latter possessing a uniform pdf on the Poincare sphere (PS), with a probability measure given by a fractional surface area. To that end, we develop a parameter to estimate polarization …

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Asymptotics Of The Rate Function In The Large Deviation Principle For Sums Of Independent Identically Distributed Random Variables, Iosif Pinelis Mar 2024

Asymptotics Of The Rate Function In The Large Deviation Principle For Sums Of Independent Identically Distributed Random Variables, Iosif Pinelis

Michigan Tech Publications, Part 2

Let Λ∗be the rate function in the large deviation principle for the sums X1 + · · · + Xn of independent identically distributed random variables X1, X2, …. It is shown that Λ∗(x) ∼ − ln P(X1 ≥ x) (as x → ∞) if and only if ln P(X1 ≥ x) ∼ L0(x) for some concave function L0. The main ingredient of the proof is the general, explicit expression of a suitable quasi-minimizer in t ≥ 0 of the Bernstein–Chernoff upper bound e−txEetX1 on P(X1 ≥ x), which is amenable to analysis and, at the same time, is close …

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Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan Mar 2024

Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan

Michigan Tech Publications, Part 2

Neuroinflammation and brain oxidative stress are recognized as significant contributors to hypertension including salt sensitive hypertension. Extracellular vesicles (EVs) play an essential role in intercellular communication in various situations, including physiological and pathological ones. Based on this evidence, we hypothesized that EVs derived from the brains of hypertensive rats with salt sensitivity could trigger neuroinflammation and oxidative stress during hypertension development. To test this hypothesis, we compared the impact of EVs isolated from the brains of hypertensive Dahl Salt-Sensitive rats (DSS) and normotensive Sprague Dawley (SD) rats on inflammatory factors and mitochondrial reactive oxygen species (mtROS) production in primary neuronal …

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Light Curve And Hardness Tests For Millilensing In Grb 081122a, Grb 081126a, Grb 110517b, And Grb 210812a, Oindabi Mukherjee, Robert J. Nemiroff Mar 2024

Light Curve And Hardness Tests For Millilensing In Grb 081122a, Grb 081126a, Grb 110517b, And Grb 210812a, Oindabi Mukherjee, Robert J. Nemiroff

Michigan Tech Publications, Part 2

Analyses are given on four recent gravitational millilensing claims on gamma-ray bursts (GRBs): GRB 081122A, GRB 081126A, GRB 110517B, and GRB 210812A. Two tests, a light curve similarity test and a hardness similarity test, compare different temporal sections of a single GRB to see if they are statistically similar. The hardness similarity test shows that the ratio between the second and the first emission episodes in each energy channel differed from the same ratio averaged over all energy channels at above 90 per cent confidence level in GRB 081122A. Additionally, the light curve similarity test applied to GRB 081122A, GRB …

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Progress In Electronic, Energy, Biomedical And Environmental Applications Of Boron Nitride And Mos2 Nanostructures, Join Uddin, Raksha Dubey, Vinaayak Sivam Balasubramaniam, Jeff Kabel, Vedika Khare, Zohreh Salimi, Sambhawana Sharma, Dongyan Zhang, Yoke Khin Yap Feb 2024

Progress In Electronic, Energy, Biomedical And Environmental Applications Of Boron Nitride And Mos2 Nanostructures, Join Uddin, Raksha Dubey, Vinaayak Sivam Balasubramaniam, Jeff Kabel, Vedika Khare, Zohreh Salimi, Sambhawana Sharma, Dongyan Zhang, Yoke Khin Yap

Michigan Tech Publications, Part 2

In this review, we examine recent progress using boron nitride (BN) and molybdenum disulfide (MoS) nanostructures for electronic, energy, biomedical, and environmental applications. The scope of coverage includes zero-, one-, and two-dimensional nanostructures such as BN nanosheets, BN nanotubes, BN quantum dots, MoS nanosheets, and MoS quantum dots. These materials have sizable bandgaps, differentiating them from other metallic nanostructures or small-bandgap materials. We observed two interesting trends: (1) an increase in applications that use heterogeneous materials by combining BN and MoS nanostructures with other nanomaterials, and (2) strong research interest in environmental applications. Last, we encourage researchers to study how …

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First-Principles Study Of Hydrogen Storage Application Of Ti3c2tx Monolayer Mxene, Yi Zhi Chu, Kah Chun Lau Feb 2024

First-Principles Study Of Hydrogen Storage Application Of Ti3c2tx Monolayer Mxene, Yi Zhi Chu, Kah Chun Lau

Michigan Tech Publications, Part 2

MXene, with its high aspect ratio and adjustable surface properties, has garnered significant attention in the realm of hydrogen storage research. For the first time, considering a ternary/quaternary mixed terminated MXene surface, the authors have investigated comprehensively the hydrogen storage potential of two-dimensional (2D) titanium carbide Ti3C2Tx monolayer MXene using density functional theory (DFT). By considering mixed terminated surfaces, this study indicated the locally induced dipole due to the mixed termination is beneficial in facilitating hydrogen adsorption with stronger average adsorption energies than that of the uniform F-/O-/OH-/H-terminated surfaces. The authors estimated a compelling average H2 surface adsorption energy on …

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Hadamard Matrices Of Orders 60 And 64 With Automorphisms Of Orders 29 And 31, Makoto Araya, Masaaki Harada, Vladimir Tonchev Feb 2024

Hadamard Matrices Of Orders 60 And 64 With Automorphisms Of Orders 29 And 31, Makoto Araya, Masaaki Harada, Vladimir Tonchev

Michigan Tech Publications, Part 2

A classification of Hadamard matrices of order 2p + 2 with an automorphism of order p is given for p = 29 and 31. The ternary self-dual codes spanned by the newly found Hadamard matrices of order 60 with an automorphism of order 29 are computed, as well as the binary doubly even self-dual codes of length 120 with generator matrices defined by related Hadamard designs. Several new ternary near-extremal self-dual codes, as well as binary near-extremal doubly even self-dual codes with previously unknown weight enumerators are found.

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Sustainability Of Biogas Production From Anaerobic Digestion Of Food Waste And Animal Manure, Sharath Kumar Ankathi, Utkarsh S. Chaudhari, Robert Handler, David R. Shonnard Feb 2024

Sustainability Of Biogas Production From Anaerobic Digestion Of Food Waste And Animal Manure, Sharath Kumar Ankathi, Utkarsh S. Chaudhari, Robert Handler, David R. Shonnard

Michigan Tech Publications, Part 2

Anaerobic digestion (AD) involves a set of microbiological reactions and physio-chemical processes to generate biogas, a mixture of predominantly CH4 and CO2. It is commercialized globally; however, AD has limited commercial applications in the U.S. compared to other regions of the world. The main objective of this article is to review different studies on socio-economic and environmental aspects and policies of biogas/biomethane production and to focus on resource availability. The key outcome from this review shows that the anaerobic digestion of food waste and animal manure has great potential to achieve economic and environmental benefits compared to other waste management …

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Detection Of Small Drizzle Droplets In A Large Cloud Chamber Using Ultrahigh-Resolution Radar, Zeen Zhu, Fan Yang, Pavlos Kollias, Raymond A. Shaw, Alexander Kostinski, Steve Krueger, Katia Lamer, Nithin Allwayin, Mariko Oue Feb 2024

Detection Of Small Drizzle Droplets In A Large Cloud Chamber Using Ultrahigh-Resolution Radar, Zeen Zhu, Fan Yang, Pavlos Kollias, Raymond A. Shaw, Alexander Kostinski, Steve Krueger, Katia Lamer, Nithin Allwayin, Mariko Oue

Michigan Tech Publications, Part 2

A large convection-cloud chamber has the potential to produce drizzle-sized droplets, thus offering a new opportunity to investigate aerosol-cloud-drizzle interactions at a fundamental level under controlled environmental conditions. One key measurement requirement is the development of methods to detect the low-concentration drizzle drops in such a large cloud chamber. In particular, remote sensing methods may overcome some limitations of in situ methods. Here, the potential of an ultrahigh-resolution radar to detect the radar return signal of a small drizzle droplet against the cloud droplet background signal is investigated. It is found that using a small sampling volume is critical to …

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First-Principles Study Of Mxene Properties With Varying Hydrofluoric Acid Concentration, Yi Zhi Chu, Megan Hoover, Patrick Ward, Kah Chun Lau Feb 2024

First-Principles Study Of Mxene Properties With Varying Hydrofluoric Acid Concentration, Yi Zhi Chu, Megan Hoover, Patrick Ward, Kah Chun Lau

Michigan Tech Publications, Part 2

With varying hydrofluoric acid (HF) concentrations under three etching conditions, we presented a comparative study of the effects of both the ordered and randomly ternary mixed terminated Ti3C2Tx surfaces with a wide variation of O/OH/F stoichiometry on the thermodynamic stability and electronic properties. Regardless of the HF concentration, an OH-rich surface is found to be thermodynamically stable and the electrical conductivity of Ti3C2Tx is substantially affected by the OH concentration. The charge density difference and electron localization function demonstrated a significant electron localization at the hydroxyl group on the O/OH/F mixed terminated surface, which could yield a locally induced dipole …

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Search For Decaying Dark Matter In The Virgo Cluster Of Galaxies With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, H. A. Ayala Solares, R. Babu, R. Turner, X. Wang, Et Al. Feb 2024

Search For Decaying Dark Matter In The Virgo Cluster Of Galaxies With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, H. A. Ayala Solares, R. Babu, R. Turner, X. Wang, Et Al.

Michigan Tech Publications, Part 2

The decay or annihilation of dark matter particles may produce a steady flux of very-high-energy gamma rays detectable above the diffuse background. Nearby clusters of galaxies provide excellent targets to search for the signatures of particle dark matter interactions. In particular, the Virgo cluster spans several degrees across the sky and can be efficiently probed with a wide field-of-view instrument. The High Altitude Water Cherenkov (HAWC) observatory, due to its wide field of view and sensitivity to gamma rays at an energy scale of 300 GeV-100 TeV is well-suited for this search. Using 2141 days of data, we search for …

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Resolving The Topology Of Encircling Multiple Exceptional Points, Chitres Guria, Qi Zhong, Sahin Kaya Ozdemir, Yogesh S.S. Patil, Ramy El-Ganainy, Jack Gwynne Emmet Harris Feb 2024

Resolving The Topology Of Encircling Multiple Exceptional Points, Chitres Guria, Qi Zhong, Sahin Kaya Ozdemir, Yogesh S.S. Patil, Ramy El-Ganainy, Jack Gwynne Emmet Harris

Michigan Tech Publications, Part 2

Non-Hermiticity has emerged as a new paradigm for controlling coupled-mode systems in ways that cannot be achieved with conventional techniques. One aspect of this control that has received considerable attention recently is the encircling of exceptional points (EPs). To date, most work has focused on systems consisting of two modes that are tuned by two control parameters and have isolated EPs. While these systems exhibit exotic features related to EP encircling, it has been shown that richer behavior occurs in systems with more than two modes. Such systems can be tuned by more than two control parameters, and contain EPs …

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The Microverse: A Task-Oriented Edge-Scale Metaverse, Qian Qu, Mohsen Hatami, Ronghua Xu, Deeraj Nagothu, Yu Chen, Xiaohua Li, Erik Blasch, Erika Ardiles-Cruz, Genshe Chen Feb 2024

The Microverse: A Task-Oriented Edge-Scale Metaverse, Qian Qu, Mohsen Hatami, Ronghua Xu, Deeraj Nagothu, Yu Chen, Xiaohua Li, Erik Blasch, Erika Ardiles-Cruz, Genshe Chen

Michigan Tech Publications, Part 2

Over the past decade, there has been a remarkable acceleration in the evolution of smart cities and intelligent spaces, driven by breakthroughs in technologies such as the Internet of Things (IoT), edge–fog–cloud computing, and machine learning (ML)/artificial intelligence (AI). As society begins to harness the full potential of these smart environments, the horizon brightens with the promise of an immersive, interconnected 3D world. The forthcoming paradigm shift in how we live, work, and interact owes much to groundbreaking innovations in augmented reality (AR), virtual reality (VR), extended reality (XR), blockchain, and digital twins (DTs). However, realizing the expansive digital vista …

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Deep Neural Network-Oriented Indicator Method For Inverse Scattering Problems Using Partial Data, Yule Lin, Xiaoyi Yan, Jiguang Sun, Juan Liu Feb 2024

Deep Neural Network-Oriented Indicator Method For Inverse Scattering Problems Using Partial Data, Yule Lin, Xiaoyi Yan, Jiguang Sun, Juan Liu

Michigan Tech Publications, Part 2

We consider the inverse scattering problem to reconstruct an obstacle using partial far-field data due to one incident wave. A simple indicator function, which is negative inside the obstacle and positive outside of it, is constructed and then learned using a deep neural network (DNN). The method is easy to implement and effective as demonstrated by numerical examples. Rather than developing sophisticated network structures for the classical inverse operators, we reformulate the inverse problem as a suitable operator such that standard DNNs can learn it well. The idea of the DNN-oriented indicator method can be generalized to treat other partial …

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Unusual Catalytic Strategy By Non-Heme Fe(Ii)/2-Oxoglutarate-Dependent Aspartyl Hydroxylase Asph, Anandhu Krishnan, Sodiq Waheed, Ann Varghese, Fathima Hameed Cherilakkudy, Christopher J. Schofield, Tatyana G. Karabencheva-Christova Feb 2024

Unusual Catalytic Strategy By Non-Heme Fe(Ii)/2-Oxoglutarate-Dependent Aspartyl Hydroxylase Asph, Anandhu Krishnan, Sodiq Waheed, Ann Varghese, Fathima Hameed Cherilakkudy, Christopher J. Schofield, Tatyana G. Karabencheva-Christova

Michigan Tech Publications, Part 2

Biocatalytic C-H oxidation reactions are of important synthetic utility, provide a sustainable route for selective synthesis of important organic molecules, and are an integral part of fundamental cell processes. The multidomain non-heme Fe(ii)/2-oxoglutarate (2OG) dependent oxygenase AspH catalyzes stereoselective (3R)-hydroxylation of aspartyl- and asparaginyl-residues. Unusually, compared to other 2OG hydroxylases, crystallography has shown that AspH lacks the carboxylate residue of the characteristic two-His-one-Asp/Glu Fe-binding triad. Instead, AspH has a water molecule that coordinates Fe(ii) in the coordination position usually occupied by the Asp/Glu carboxylate. Molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) studies reveal that the iron coordinating water is …

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Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han Feb 2024

Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han

Michigan Tech Publications, Part 2

Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction-a measure of …

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Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish K. Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han Feb 2024

Low Shear In Short-Term Impacts Endothelial Cell Traction And Alignment In Long-Term, Mohanish K. Chandurkar, Nikhil Mittal, Shaina P. Royer-Weeden, Steven D. Lehmann, Yeonwoo Rho, Sangyoon J. Han

Michigan Tech Publications, Part 2

Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction—a measure of …

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Galactic Gamma-Ray Diffuse Emission At Tev Energies With Hawc Data, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, R. Babu, Et Al. Jan 2024

Galactic Gamma-Ray Diffuse Emission At Tev Energies With Hawc Data, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, R. Babu, Et Al.

Michigan Tech Publications, Part 2

Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons, and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of teraelectronvolt diffuse emission from a region of the Galactic plane over the range in longitude of l ∈ [43°, 73°], using data collected with the High Altitude Water Cherenkov (HAWC) detector. Spectral, longitudinal, and latitudinal distributions of the teraelectronvolt diffuse emission are shown. The radiation spectrum is compatible with the spectrum of the emission arising from a CR population with an index similar to that of the observed …

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Radio Measurements Of The Depth Of Air-Shower Maximum At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al. Jan 2024

Radio Measurements Of The Depth Of Air-Shower Maximum At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest array of radio antenna stations deployed for the detection of cosmic rays, spanning an area of 17 km2 with 153 radio stations. It detects the radio emission of extensive air showers produced by cosmic rays in the 30-80 MHz band. Here, we report the AERA measurements of the depth of the shower maximum (Xmax), a probe for mass composition, at cosmic-ray energies between 1017.5 and 1018.8 eV, which show agreement with earlier measurements with the fluorescence technique at the Pierre Auger Observatory. We show …

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Demonstrating Agreement Between Radio And Fluorescence Measurements Of The Depth Of Maximum Of Extensive Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al. Jan 2024

Demonstrating Agreement Between Radio And Fluorescence Measurements Of The Depth Of Maximum Of Extensive Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

We show, for the first time, radio measurements of the depth of shower maximum (Xmax) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio Xmax resolution as a function of energy and demonstrate the ability to make competitive high-resolution Xmax …

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Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw Jan 2024

Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw

Michigan Tech Publications, Part 2

Collisional growth of cloud droplets is an essential yet uncertain process for drizzle and precipitation formation. To improve the quantitative understanding of this key component of cloud-aerosol-turbulence interactions, observational studies of collision-coalescence in a controlled laboratory environment are needed. In an existing convection-cloud chamber (the Pi Chamber), collisional growth is limited by low liquid water content and short droplet residence times. In this work, we use numerical simulations to explore various configurations of a convection-cloud chamber that may intensify collision-coalescence. We employ a large-eddy simulation (LES) model with a size-resolved (bin) cloud microphysics scheme to explore how cloud properties and …

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Integrating External Controls By Regression Calibration For Genome-Wide Association Study, Lirong Zhu, Shijia Yan, Xuewei Cao, Shuanglin Zhang, Qiuying Sha Jan 2024

Integrating External Controls By Regression Calibration For Genome-Wide Association Study, Lirong Zhu, Shijia Yan, Xuewei Cao, Shuanglin Zhang, Qiuying Sha

Michigan Tech Publications, Part 2

Genome-wide association studies (GWAS) have successfully revealed many disease-associated genetic variants. For a case-control study, the adequate power of an association test can be achieved with a large sample size, although genotyping large samples is expensive. A cost-effective strategy to boost power is to integrate external control samples with publicly available genotyped data. However, the naive integration of external controls may inflate the type I error rates if ignoring the systematic differences (batch effect) between studies, such as the differences in sequencing platforms, genotype-calling procedures, population stratification, and so forth. To account for the batch effect, we propose an approach …

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Innovative Cyanine-Based Fluorescent Dye For Targeted Mitochondrial Imaging And Its Utility In Whole-Brain Visualization, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi Jan 2024

Innovative Cyanine-Based Fluorescent Dye For Targeted Mitochondrial Imaging And Its Utility In Whole-Brain Visualization, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications, Part 2

Conducting in vivo brain imaging can be a challenging task due to the complexity of brain tissue and the strict requirements for safe and effective imaging agents. However, a new fluorescent dye called Cy5-PEG2 has been developed that selectively accumulates in mitochondria, enabling the visualization of these essential organelles in various cell lines. This dye is versatile and can be used for the real-time monitoring of mitochondrial dynamics in living cells. Moreover, it can cross the blood-brain barrier, making it a promising tool for noninvasive in vivo brain imaging. Based on the assessment of glial cell responses in the hippocampus …

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Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner Jan 2024

Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner

Dissertations, Master's Theses and Master's Reports

The unifying theme of this thesis is the characterization of “perfect randomness,” i.e., independent and identically distributed (IID) stochastic processes as these are applied in physical science. Two specific and mathematically distinct applications are chosen: (i) Radar and optical polarimetry; (ii) Analysis of time series in meteorology. In (i), IID process of a special kind, namely, with a distribution defined by symmetry, is used to link its multivariate Gaussian density to uniformity on the Poincaré sphere. This “statistical ellipsometry” approach is then used to relate polarimetric mismatches or imbalances to ellipsometric variables and suitably chosen cross-correlation measures. In (ii), recently …

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Anomaly Mapping Of Heavy And Light Rare Earth Elements In Central Upper Peninsula Of Michigan Using Geostatistics And Fractal Analysis, Sunday Joseph Jan 2024

Anomaly Mapping Of Heavy And Light Rare Earth Elements In Central Upper Peninsula Of Michigan Using Geostatistics And Fractal Analysis, Sunday Joseph

Dissertations, Master's Theses and Master's Reports

Rare earth elements (REEs) have gained significant global importance due to their critical role in supporting the transition towards reduced carbon emissions through industrial applications. REEs serve as essential raw materials for various critical components in modern infrastructure, defense systems, and technological advancements. Geochemical and geophysical data are pivotal in assessing the potential of REEs. Geochemical data provide direct insights into the elemental composition of rocks and soils, offering valuable information on the potential presence and dispersion of REEs. However, the complex geological processes that influence the distribution of REEs often exhibit intricate spatial patterns that may not be fully …

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Understanding The Controls Of Seasonal Stream Temperature And Hydrological Monitoring Of Forested Watersheds In The Western Upper Peninsula Of Michigan, Eli A. Paulen Jan 2024

Understanding The Controls Of Seasonal Stream Temperature And Hydrological Monitoring Of Forested Watersheds In The Western Upper Peninsula Of Michigan, Eli A. Paulen

Dissertations, Master's Theses and Master's Reports

Accurately predicting stream temperature is vital to protect the environment and its most sensitive aquatic species. Tools for forecasting stream temperature rely on in situ data that affect thermal response of natural water systems. Stream and meteorological data were analyzed from the western Upper Peninsula of Michigan for the 2016-2023 water years to determine which factors affected stream temperatures. Through the application of multivariable linear regression models, our analysis identified air temperature as the primary determinant of stream temperature. However, the air-stream temperature relationship varied significantly over temporal scales, improving with increasing in time averaging. The air-stream temperature relationship was …

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Establishing A Two-Color Fluorescence Probe Assay For The Simultaneous Screening Of Glut5 And Glut2 Fructose Transporters In Live Cells, Oluwanifesimi Mary Afolabi Jan 2024

Establishing A Two-Color Fluorescence Probe Assay For The Simultaneous Screening Of Glut5 And Glut2 Fructose Transporters In Live Cells, Oluwanifesimi Mary Afolabi

Dissertations, Master's Theses and Master's Reports

The mammalian facilitative glucose transporter (GLUT) family comprises 14 members that mediate the transport of hexoses across cell membranes. GLUT5 is the only member specific to fructose, and together with GLUT2, which transports fructose in addition to glucose, they make up the primary fructose transporters in humans. This study introduces a novel two-color fluorescence assay designed to simultaneously monitor the activity of GLUT5 and GLUT2 in live cells. 2,5-anhydro-D-mannitol (2,5-AM) a GLUT5 targeting compound has facilitated the development of various fructose-mimicking probes with a wide range of properties, such as radioactive imaging, fluorescent, photoactive, and drug delivery capabilities. Effective and …

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Programming By Voice, Sadia Nowrin Jan 2024

Programming By Voice, Sadia Nowrin

Dissertations, Master's Theses and Master's Reports

Programmers typically rely on a keyboard and mouse for input, which poses significant challenges for individuals with motor impairments, limiting their ability
to effectively input programs. Voice-based programming offers a promising alternative,
enabling a more inclusive and accessible programming environment. Insights from interviews with motor-impaired programmers revealed that memorizing unnatural commands in existing voice-based programming systems led to frustration. In this work, we explore how programmers naturally speak a single line of code and present a comprehensive methodology for a voice programming system aimed at making programming more accessible for diverse users. To achieve this, we adopted a two-step pipeline. …

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