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Articles 481 - 510 of 34271

Full-Text Articles in Physics

Discovery Of A New Cataclysmic Variable, Galex J211240.9–422959, Via The Exoasteroids Citizen Science Project, Mei Lin, Aaron Meisner, Siyi Xu, Arttu Sainio, Liliana E. Rivera Sandoval, Paula Szkody, Christopher Tanner, Laura K. Rogers, Sarah Casewell, Austin Humphreys Apr 2026

Discovery Of A New Cataclysmic Variable, Galex J211240.9–422959, Via The Exoasteroids Citizen Science Project, Mei Lin, Aaron Meisner, Siyi Xu, Arttu Sainio, Liliana E. Rivera Sandoval, Paula Szkody, Christopher Tanner, Laura K. Rogers, Sarah Casewell, Austin Humphreys

Physics & Astronomy Faculty Publications

We report the discovery and spectroscopic classification of a new cataclysmic variable (CV), GALEX J211240.9–422959 (Gaia DR3 source ID 6580244356829724928). This object was initially identified as a source exhibiting strong mid-infrared variability in Wide-field Infrared Survey Explorer (WISE) time-series data by a volunteer participating in the Exoasteroids citizen science project. Prompted by this strong variability at 3–5 μm, we obtained a follow-up optical spectrum using the Gemini Multi-Object Spectrograph at the Gemini South Observatory. The resulting spectrum displays a blue continuum dominated by strong, broad emission lines of the hydrogen Balmer series and neutral helium, spectral signatures characteristic of …

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A Search For Magnetically Active Binary Counterparts To Chandra X-Ray Sources In 47 Tucanae With Hst Imaging, Haldan N. Cohn, Phyllis M. Lugger, Craig O. Heinke, Maureen Van Den Berg, Liliana Rivera Sandoval, Jay Anderson Apr 2026

A Search For Magnetically Active Binary Counterparts To Chandra X-Ray Sources In 47 Tucanae With Hst Imaging, Haldan N. Cohn, Phyllis M. Lugger, Craig O. Heinke, Maureen Van Den Berg, Liliana Rivera Sandoval, Jay Anderson

Physics & Astronomy Faculty Publications

Using Hubble Space Telescope (HST) imaging, we searched for candidate magnetically active binary (AB) counterparts to low-luminosity Chandra X-ray sources in the globular cluster 47 Tucanae (NGC 104). We consider the catalog of 300 Chandra sources within the half-light radius of 47 Tuc compiled by C. O. Heinke et al. (2005). The 10-band HST imaging used to identify these sources spans the range from 275–658 nm. We generated a cross-matched catalog of objects detected by photometric reductions. We used this catalog to search for counterparts within Chandra source error circles using color–magnitude diagrams and a color–color plot. We …

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Developing A Multi-Band Gnss Remote Sensing Station To Measure Precipitable Water Vapor For Flash Flood Nowcasting, Madison Gleydura Apr 2026

Developing A Multi-Band Gnss Remote Sensing Station To Measure Precipitable Water Vapor For Flash Flood Nowcasting, Madison Gleydura

Doctoral Dissertations and Master's Theses

Flash flood nowcasting in Central and Southern Appalachia is particularly challenging due to steep terrain, narrow valleys, highly localized rainfall patterns, and limited measurement coverage. Traditional remote sensing methods, such as Doppler radar and microwave radiometry, suffer from reduced resolution at long range and signal blockage by mountains. GNSS-meteorology offers an established alternative for measuring precipitable water vapor and is currently integrated into several numerical weather models. Recent research demonstrates that commercial-grade GNSS receivers can produce tropospheric products comparable to those from geodetic-grade equipment. The gaps in mountain coverage can be addressed by developing a low-cost, self-contained embedded system that …

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Tracing Cosmic Origins: Investigating Carbon Isotopic Ratios To Unlock Universal Insights, Karthik Gananath Putha Apr 2026

Tracing Cosmic Origins: Investigating Carbon Isotopic Ratios To Unlock Universal Insights, Karthik Gananath Putha

Theses and Dissertations

The universe is made up of a vast and diverse collection of elements. All elements with atomic mass number A > 12, ranging from carbon to iron, are continuously enriched over the course of galactic evolution through stellar nucleosynthesis. In contrast, elements heavier than 56 Fe are primarily synthesized via neutron-capture processes, occurring in Asymptotic Giant Branch (AGB) stars, core-collapse supernovae, and more extreme events such as binary neutron star mergers. These elements are later expelled into the surrounding space through powerful supernova explosions. Overtime, these processes enrich the interstellar medium with heavy elements and thus plays an important role in …

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Information Theory Analysis Of The Solar Wind Magnetic Structures For Space Weather Prediction, Katherine Holland Apr 2026

Information Theory Analysis Of The Solar Wind Magnetic Structures For Space Weather Prediction, Katherine Holland

Doctoral Dissertations and Master's Theses

Forecasting space weather at Earth is highly complicated, because of the limited measurements of the dynamic processes in the Sun that span multiple temporal, spatial, and energy-scales. The solar wind is a highly structured, multi-scale, evolving plasma and consists of coronal mass ejections (CMEs), stream interaction regions (SIRs), expanding flux tubes (Borovsky, 2008), and interplanetary magnetic field (IMF) discontinuities and fluctuations. The aim of this research is to improve our understanding of the evolution and dissipation of different scale-size solar wind magnetic structures as they move from the Sun-Earth Lagrange point 1 (L1) to Earth's bow shock and, ultimately, to …

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Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler Apr 2026

Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler

Faculty Publications

We apply Bayesian inference to the order-by-order chiral perturbation theory (χPT) expansions for the axial-vector coupling constant gA and the nucleon mass mN, and thereby infer the scales at which χPT breaks down for these two observables. Using a pointwise Bayesian analysis, we find that the inferred breakdown scales are notably different for the two observables. For the chiral expansion of gA, we obtain 251+20−50 MeV and 211+20−30 MeV using two distinct sets of low-energy constants, while for the chiral expansion of mN we infer a significantly …

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Antimicrobial Performance Of Amorphous Vs. Crystalline La1-Xsrxcoo3 Perovskites, S. M. Au Shohag, Fahmida Akhter, Ahmed Touhami, Swati Mohan, Md. Wasikur Rahman, Mohammed Jasim Uddin Apr 2026

Antimicrobial Performance Of Amorphous Vs. Crystalline La1-Xsrxcoo3 Perovskites, S. M. Au Shohag, Fahmida Akhter, Ahmed Touhami, Swati Mohan, Md. Wasikur Rahman, Mohammed Jasim Uddin

Physics & Astronomy Faculty Publications

Perovskite materials, with their unique crystal structure and chemical properties, are emerging as promising antimicrobial agents for potential biomedical applications. In this research, different weight percentages of Sr2 + doped amorphous and crystalline Lanthanum Cobaltite (La1-xSrxCoO3 defined as LSCO) (x = 0, 0.025, 0.05, 0.1, and 0.15) perovskite was synthesized by using a simple combination of sol-gel and molten-salt processes and characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) ensures the uniform morphology of the materials. During antimicrobial study using the Kirby Bauer method, amorphous LSCO showed much better activity than crystalline LSCO against Escherichia coli, Vibrio …

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Radiation Protection Factor Research: The Keystone For Conventional-Nuclear Integration (Cni), Andrew W. Decker Apr 2026

Radiation Protection Factor Research: The Keystone For Conventional-Nuclear Integration (Cni), Andrew W. Decker

Faculty Publications

This article briefly describes Defense Threat Reduction Agency (DTRA) vehicle Radiation Protection Factor (RPF) research and explains its critical role in enabling future Operations in a Nuclear Environment (ONE) and Conventional-Nuclear Integration (CNI) on behalf of the US Department of War (DoW).1 As such, the background and practical utility of RPF values is discussed, as well as the justification for renewed Army and DoW investment into RPF research to enhance Joint military planning, survivability, and lethality on tomorrow’s nuclear battlefields. Advances in DTRA RPF research directly strengthen US strategic and extended deterrence efforts and support all Agencies and Departments responsible …

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Breathing Kagome Lattice-Based Nb3i8 Monolayer: Theoretical Insights Into Enhanced Hydrogen Evolution Catalysis, Narender Kumar, Radha Somaiya, Ravindra Pandey, Nacir Tit Apr 2026

Breathing Kagome Lattice-Based Nb3i8 Monolayer: Theoretical Insights Into Enhanced Hydrogen Evolution Catalysis, Narender Kumar, Radha Somaiya, Ravindra Pandey, Nacir Tit

Michigan Tech Publications

Photocatalytic water splitting is a promising strategy for clean energy production, but its efficiency is restricted by poor light absorption, charge recombination, and slow reaction kinetics in photocatalytic materials. To address these challenges, a breathing Kagome lattice-based Nb3I8 monolayer is considered in the present study. Its photocatalytic performance is assessed via descriptors including the effective d-band center, spin-dependent carrier mobility, Gibbs free energy, and exchange-current density. The results based on density functional theory predict that the Nb3I8 monolayer is a type II magnetic semiconductor, with spin-up and spin-down bandgap energies of 1.06 and 1.77 eV, respectively. The application of biaxial …

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A Model Intercomparison Study To Investigate Mixing Characteristics In Non-Precipitating Stratocumulus Clouds, Fan Yang, Kyoung Ock Choi, Kamal Kant Chandrakar, Fabian Hoffmann, Pei Hou, Steve Krueger, Chunsong Lu, Mikhail Ovchinnikov, Yangze Ren, Shin Ichiro Shima, Peng Wu, Chongzhi Yin, Zeen Zhu, Seong Soo Yum Apr 2026

A Model Intercomparison Study To Investigate Mixing Characteristics In Non-Precipitating Stratocumulus Clouds, Fan Yang, Kyoung Ock Choi, Kamal Kant Chandrakar, Fabian Hoffmann, Pei Hou, Steve Krueger, Chunsong Lu, Mikhail Ovchinnikov, Yangze Ren, Shin Ichiro Shima, Peng Wu, Chongzhi Yin, Zeen Zhu, Seong Soo Yum

Michigan Tech Publications

Recent aircraft observations of marine stratocumulus clouds consistently showed that cloud microphysical relationships vary with altitude, indicating inhomogeneous mixing characteristics near cloud top and homogeneous mixing characteristics in mid-levels of clouds. Here, we conduct model intercomparison of an idealized, non-precipitating stratocumulus cloud to evaluate model consistency and examine whether simulations can reproduce the observed mixing characteristics. The results show that eleven large-eddy simulations with various dynamics and microphysics schemes show good agreement on the thermodynamical, microphysical, and dynamical properties of the stratocumulus-topped boundary layer in a steady state. The inter-model spread in steady-state liquid water path is significantly reduced compared …

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Application Of The Tridiagonal Representation Approach And The J- Matrix Method Of Scattering In Theoretical Physics, Tunde Joseph Osunmusanmi Apr 2026

Application Of The Tridiagonal Representation Approach And The J- Matrix Method Of Scattering In Theoretical Physics, Tunde Joseph Osunmusanmi

Dissertations

This dissertation is about the application of the Tridiagonal Representation Approach (TRA) in handling linear phenomenons, and for the first time, the J-matrix method of scattering in handling nonlinear phenomenons. The TRA is an algebraic method for solving linear ordinary differential equations of the second order. The advantage of the method in being algebraic is reinforced by the analytic power of orthogonal polynomials and special functions. On the computational side, it is favored as being reliant on powerful numerical techniques that deal with tridiagonal matrices such as Gauss quadrature and continued fraction. In the method, the solution of the differential …

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Non-Hermitian Sl (3, C) Three-Mode Couplers, B. M. Rodríguez-Lara, Hamed Ghaemi-Dizicheh, Shahram Dehdashti, Andreas Hanke, Ahmed Touhami, J. Nötzel Mar 2026

Non-Hermitian Sl (3, C) Three-Mode Couplers, B. M. Rodríguez-Lara, Hamed Ghaemi-Dizicheh, Shahram Dehdashti, Andreas Hanke, Ahmed Touhami, J. Nötzel

Physics & Astronomy Faculty Publications

Photonic systems with exceptional points, where eigenvalues and corresponding eigenstates coalesce, have attracted interest due to their topological features and enhanced sensitivity to external perturbations. Non-Hermitian mode-coupling matrices provide a tractable analytic framework to model gain, loss, and chirality across optical, electronic, and mechanical platforms without the complexity of full open-system dynamics. Exceptional points define their spectral topology, and enable applications in mode control, amplification, and sensing. Yet N -mode couplers, the minimal setting for N th-order exceptional points, are often studied in specific designs that overlook their algebraic structure. We introduce a general sl(N , C) framework for arbitrary …

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Bifurcation Exploration Of Ion Acoustic Solitons Formation Of A Nonlinear Beta Fractional Kadomtsev-Petviashvili Burger Model In Plasma State, Mst. Razia Pervin, Alrazi Abdeljabbar, Fahad Sameer Alshammari, Mst. Shekha Khatun, Harun Or-Roshid Mar 2026

Bifurcation Exploration Of Ion Acoustic Solitons Formation Of A Nonlinear Beta Fractional Kadomtsev-Petviashvili Burger Model In Plasma State, Mst. Razia Pervin, Alrazi Abdeljabbar, Fahad Sameer Alshammari, Mst. Shekha Khatun, Harun Or-Roshid

Mathematical Modelling and Numerical Simulation with Applications

This research presents an extensive investigation of Ion acoustic soliton dynamics governed by a Beta-fractional Kadomtsev-Petviashvili-Burgurs (KPB) model. By engaging the planar dynamical system scheme in aggregation with the extended $(\phi, \psi)$ expansion, Kudryashov expansion, and the NMKM analytic schemes, we create a broad class of exact nonlinear pattern wave solutions. The local stability edifice of the fractional plasma model is explored through bifurcation theory, enabling the far-reaching classification of all admissible phase diagrams. Conforming Ion acoustic wave structures allied with every detour alignment are systematically assembled. Owing to the fractional and dissipative appearances of the model, an all-embracing assortment …

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Markov-Modulated Queueing Network For Mobile Traffic Aggregation With Threshold-Controlled Buffers, Anton A. Esin, Elmira Yu. Kalimulina Mar 2026

Markov-Modulated Queueing Network For Mobile Traffic Aggregation With Threshold-Controlled Buffers, Anton A. Esin, Elmira Yu. Kalimulina

Mathematical Modelling and Numerical Simulation with Applications

We study the problem of data transmission from mobile platforms operating in high-speed transit between cellular base stations, under conditions of unstable and intermittent connectivity. Conventional queueing and connectivity models often fail to capture the combined effects of rapidly changing signal conditions, finite buffer capacity, and dynamic topology. We aim to develop a tractable yet expressive model that integrates stochastic link availability, queue dynamics, and buffer control. We propose a mathematical framework based on queues whose service intensities are modulated by a continuous-time Markov chain (CTMC) representing signal conditions along a high-speed trajectory. The core subsystem is a two-stage (aggregation …

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Quantum Superpositions Of Conscious States In A Minimal Integrated Information Model, Kelvin J. Mcqueen, Ian T. Durham, Markus P. Müller Mar 2026

Quantum Superpositions Of Conscious States In A Minimal Integrated Information Model, Kelvin J. Mcqueen, Ian T. Durham, Markus P. Müller

Philosophy Faculty Articles and Research

Could there be quantum superpositions of conscious states, as suggested by the Wigner’s friend thought experiment? Mathematical theories of consciousness, notably integrated information theory (IIT), make this question more precise by associating physical systems with both quantitative amounts of consciousness and structural characterizations of conscious states. Motivated by a recent proposal that ties wave-function collapse to integrated information, we construct a simple quantum circuit that would, on that proposal, place a minimal system—a feedback dyad—into a superposition of states that differ in their associated conscious states. This “Schrödinger’s dyad” provides a controlled setting for evaluating a central desideratum of consciousness-based …

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On Links Between A Theorem Of Schoenberg, Rohlin Decompositions Of Measures, The Bochner-Minlos Theorem And The Fock Space, Daniel Alpay, Paula Cerejeiras, Palle Jorgensen, Uwe Kaehler Mar 2026

On Links Between A Theorem Of Schoenberg, Rohlin Decompositions Of Measures, The Bochner-Minlos Theorem And The Fock Space, Daniel Alpay, Paula Cerejeiras, Palle Jorgensen, Uwe Kaehler

Mathematics, Physics, and Computer Science Faculty Articles and Research

The main goal of this paper is to gain new results in stochastics by drawing on, and combining, different areas that are normally not considered to be related. Thus, in this paper we extend the previous class of Gaussian-like functions ML which will allow for future generalized stochastic processes in infinite dimensional analysis. We show that an approach similar to the one by the classical Bochner-Minlos theorem for the white-noise case can be achieved by using Gaussian-like functions belonging to a large family -the MLr classes (0 < r ≤∞). We show how Schoenberg’s theorem for positive definite functions on a Hilbert space allows to go beyond the classical setting of Bochner-Milnos theorem. Furthermore, we show that the application of the Rohlin’s disintegration theorem allows for a decomposition of the associated probability measures , see Theorems 3.2 and 4.3. We end this paper with several important examples of functions in these classes MLr and provide some interesting counterexamples, e.g. Theorem 7.4, to get a …

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Quantum Indiscernibility And Perspectivalism, Emily Adlam Mar 2026

Quantum Indiscernibility And Perspectivalism, Emily Adlam

Mathematics, Physics, and Computer Science Faculty Articles and Research

It has often been suggested that similar quantum particles may be a counterexample to the principle of the Identity of Indiscernibles. In this article, I discuss the status of indiscernibility in a perspectival approach to quantum mechanics. I argue that adopting an internal physical perspective can have the effect of making entities discernible even if they are not discernible relative to external reference frames, and thus perspectivalism offers a new way to understand the physical meaning of weak discernibility. I discuss whether this approach is circular, and I consider whether the reference frames involved are physically meaningful. I conclude that …

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Fabrication And Analysis Of Bi₂O₃/Si Heterojunction For Solar Cell Applications, Maher Khaleel Ibrahim, Assel Mustafa Abdul Majeed, Randa Kamel Husain, Jamal M. Rzaij Mar 2026

Fabrication And Analysis Of Bi₂O₃/Si Heterojunction For Solar Cell Applications, Maher Khaleel Ibrahim, Assel Mustafa Abdul Majeed, Randa Kamel Husain, Jamal M. Rzaij

Al-Bahir

Bismuth oxide (Bi₂O₃) nanoparticles were synthesized via a green route and integrated into Bi₂O₃/Si heterojunction solar cells. Structural analysis confirmed the monoclinic α-Bi₂O₃ phase with a nanoscale crystallite size, while SEM revealed a uniform morphology. Optical studies showed a direct band gap suitable for absorbing visible light. Photoluminescence spectra exhibited dual emissions at 498 nm and 250 nm, attributed to defect states and quantum confinement, highlighting the dual role of Bi₂O₃ as both absorber and transparent window layer. Electrical characterization under dark conditions demonstrated rectifying diode behavior, confirming the formation of a junction. Capacitance–voltage analysis yielded a built-in potential of …

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Precision Spectroscopy Of 2s-Ns Transitions In Atomic Hydrogen: A Determination Of The Proton Charge Radius, R. G. Bullis, W. L. Tavis, M. R. Weiss, Orellana O. Cisneros, A. J. Cheeseman, Ulrich D. Jentschura, D. C. Yost Mar 2026

Precision Spectroscopy Of 2s-Ns Transitions In Atomic Hydrogen: A Determination Of The Proton Charge Radius, R. G. Bullis, W. L. Tavis, M. R. Weiss, Orellana O. Cisneros, A. J. Cheeseman, Ulrich D. Jentschura, D. C. Yost

Physics Faculty Research & Creative Works

We present absolute frequency measurements of 2S1/2-nS1/2 two-photon transitions with n=8, 9, and 10 in a cryogenic beam of atomic hydrogen. Each transition has been measured with a fractional uncertainty of ≈2.6x10-12. Combining the results from this Letter and the 1S1/2-2S1/2 transition frequency, we extract a root-mean-square proton radius of rp=0.8433(31) fm and a Rydberg frequency of cR∞=3 289 841 960 252.9(9.7) kHz. These are in good agreement with the CODATA 2022 recommended values.

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A Study Of Transients From Ground-Based Surveys Reveals New Ultra-Compact Accreting White Dwarf Binaries, Jan Kára, Liliana E. Rivera Sandoval, Wendy Mendoza, Thomas J. Maccarone, Manuel Pichardo Marcano, Luis Salazar Manzano, Ryan J. Oelkers, Jan Van Roestel Mar 2026

A Study Of Transients From Ground-Based Surveys Reveals New Ultra-Compact Accreting White Dwarf Binaries, Jan Kára, Liliana E. Rivera Sandoval, Wendy Mendoza, Thomas J. Maccarone, Manuel Pichardo Marcano, Luis Salazar Manzano, Ryan J. Oelkers, Jan Van Roestel

Physics & Astronomy Faculty Publications

AM CVn stars are ultra-compact semi-detached binaries consisting of a white dwarf primary and a hydrogen-depleted secondary. In this paper, we present spectroscopic and photometric results of 15 transient sources pre-classified as AM CVn candidates. Our analysis confirms 9 systems of the type AM CVn, 3 hydrogen-rich cataclysmic variables (accreting white dwarfs with near-main-sequence stars for donors), and 3 systems that could be evolved cataclysmic variables. Eight of the AM CVn stars are analysed spectroscopically for the first time, which increases the number of spectroscopically confirmed AM CVns by about 10%. TESS data revealed the orbital period of the AM …

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Towards Understanding Robust Neural Coding Through Representational Geometry, Zeyuan Ye Mar 2026

Towards Understanding Robust Neural Coding Through Representational Geometry, Zeyuan Ye

Arts & Sciences Graduate Student Theses and Dissertations

Neural activity is high-dimensional and variable, yet animals represent information robustly. This thesis studies the origins of such robustness through the lens of representational geometry and deep neural network modeling. From a geometric perspective, population responses concentrate near smooth manifolds embedded in a high-dimensional state space. To infer these manifolds from noisy data and quantify their geometric properties, we develop a statistical method based on Gaussian processes and kernel regression (GKR). Applying GKR to simultaneously recorded grid-cell population activity during open-field navigation, we show that increasing running speed expands a torus-like representational manifold and improves spatial decodability. Thus, despite faster …

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Investigation Of Molecular Footprints In Ultra-High Diluted Homoeopathic Solutions Of Arnica Montana And Rhus Toxicodendron Through Combined Infrared And Impedance Spectroscopy, Sharbadeb Kundu, Usha Rani Dash, Chirasree Roychaudhuri, Aindrila Roy, Sanatan Chattopadhyay, Rathin Chakravarty, Debadatta Nayak, Subhash Kaushik, Amit Roy Chowdhury, Ananya Barui, Subhadip Chakraborty Mar 2026

Investigation Of Molecular Footprints In Ultra-High Diluted Homoeopathic Solutions Of Arnica Montana And Rhus Toxicodendron Through Combined Infrared And Impedance Spectroscopy, Sharbadeb Kundu, Usha Rani Dash, Chirasree Roychaudhuri, Aindrila Roy, Sanatan Chattopadhyay, Rathin Chakravarty, Debadatta Nayak, Subhash Kaushik, Amit Roy Chowdhury, Ananya Barui, Subhadip Chakraborty

Indian Journal of Research in Homoeopathy

Background: The study of ultra-high diluted (UHD) solutions is a compelling and controversial domain in modern science. Despite numerous investigations and hypotheses, there is a lack of rigorous, reproducible empirical evidence supporting the existence of molecular footprints beyond the Avogadro's limit. Objective: This study conducted a detailed investigation of the molecular and electrical properties, focusing on hydrogen bonding and impedance to understand the fundamental nature of UHD solutions. Materials and methods: Combined impedance and infrared spectroscopic investigations were performed to probe the structural behaviour of relevant water networks at the molecular level of UHD alcoholic extract of Arnica montana (AM) …

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Extending The Geometric Phase To Relativistic Spacetime, Sajid Raihan Akash Mar 2026

Extending The Geometric Phase To Relativistic Spacetime, Sajid Raihan Akash

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

The Berry phase [3] is traditionally understood as a geometric phase acquired during cyclic adiabatic evolution, often interpreted as the flux of an effective “magnetic field” through a solid angle in parameter space. In this thesis, we investigate situations in which a geometric phase arises even when no spatial solid angle is enclosed, revealing the limitations of the standard purely spatial interpretation. We first review the Berry phase for a spin-½ particle in a slowly varying magnetic field and analyze scenarios in which the system’s eigenstate is changed during the adiabatic evolution. We show that the resulting phase can be …

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First-Order Axial Perturbation Of The Reissner–Nordström Metric Against A Possible Parity-Violating Gravity Background, Abhishek Rout, Brett David Altschul Mar 2026

First-Order Axial Perturbation Of The Reissner–Nordström Metric Against A Possible Parity-Violating Gravity Background, Abhishek Rout, Brett David Altschul

Faculty Publications

We study axial perturbations of Reissner–Nordström black holes within the general frame-work of parity-violating modified gravity theories. We derive the governing equations for a class of frame-dragging perturbations, focusing on the symmetry structure and radial dependence of the perturbed metric component, describing its behavior across three distinct regions: near the singularity (r → 0), between the inner and outer Reissner–Nordström horizons (r− < r < r+), and in the asymptotic exterior regime (r → ∞). Using a combination of analytical and numerical methods, we analyze the solutions for varying black hole charge-to-mass ratios (Q/M) and angular momentum parameters (l). Key findings include the suppression of perturbations by the electromagnetic field for higher Q/M; the emergence of radial resonance-like behavior for specific l values; and a high degree of symmetry for solutions in the extremal limit (Q/M ∼ 1), attributed to the AdS2 × S 2 near-horizon geometry. The WKB approximation is employed to study the high-l regime, revealing quantized radial resonance modes and singular behavior in the extremal limit. Additionally, we explore the role of boundary conditions and the possibility of a Chern–Simons field Θ as the source of the parity violation, showing that consistency and the behavior of the perturbations under time reversal demand a constant field (and thus no actually observable Chern–Simons effects) at leading order. These results provide a basis for further analysis of the stability and dynamical properties of charged black holes in parity-violating theories, with potential experimental signatures in gravitational wave observations.

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Bacillus Subtilis Parb C-Terminal Lysine Residues Are Essential For Dimerization And In Vivo Function, Indicating Their Roles In Dna Sliding, Aleksey Aleshintsev, Lindsey E. Way, Ngoc Khanh Lai, Bianca Guerra, Paloma Dorantes, Lois Akosua Serwaa, Sealtiel Anulao, Miranda Molina, Xindan Wang, Hyeongjun Kim Mar 2026

Bacillus Subtilis Parb C-Terminal Lysine Residues Are Essential For Dimerization And In Vivo Function, Indicating Their Roles In Dna Sliding, Aleksey Aleshintsev, Lindsey E. Way, Ngoc Khanh Lai, Bianca Guerra, Paloma Dorantes, Lois Akosua Serwaa, Sealtiel Anulao, Miranda Molina, Xindan Wang, Hyeongjun Kim

Physics & Astronomy Faculty Publications

The broadly conserved ParB protein performs crucial functions in bacterial chromosome segregation and replication regulation. The cellular function of ParB requires it to dimerize, recognize parS DNA sequences, clamp on DNA, then slide to adjacent sequences through nonspecific DNA binding. How ParB coordinates nonspecific DNA binding and sliding remains elusive. Here, we combine multiple in vitro biophysical and computational tools and in vivo approaches to address this question. We found that five conserved lysine residues in the C-terminal domain (CTD) of ParB play distinct roles. While the two central rigid lysine residues provide the structural platform for the CTD, the …

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Cdj-Pontryagin Optimal Control For General Continuously Monitored Quantum Systems, Tathagata Karmakar, Andrew N. Jordan Mar 2026

Cdj-Pontryagin Optimal Control For General Continuously Monitored Quantum Systems, Tathagata Karmakar, Andrew N. Jordan

Mathematics, Physics, and Computer Science Faculty Articles and Research

The Chantasri-Dressel-Jordan (CDJ) stochastic path integral formalism (Chantasri et al. 2013 and 2015) characterizes the statistics of the readouts and the most likely conditional evolution of continuously monitored quantum systems involving a few qubits or quantum harmonic oscillators in Gaussian states. In our work, we generalize the CDJ formalism to arbitrary continuously monitored systems by introducing a costate operator. We then prescribe a generalized Pontryagin's maximum principle for quantum systems undergoing arbitrary evolution and find conditions on optimal control protocols. We show that the CDJ formalism's most likely path can be cast as a quantum Pontryagin's maximum principle, where the …

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Assembly And Testing Of A De-202 Closed-Cycle Cryostat, Chris Maguire Mar 2026

Assembly And Testing Of A De-202 Closed-Cycle Cryostat, Chris Maguire

SPARK Symposium Presentations

Closed-cycle cryostats, such as the Advanced Research Systems DE-202 model are commonly used in laboratories as they provide long-term, low-cost, low-maintenance operation. We will outline the assembly, testing processes, and benchmarking experiments associated with the setup of this instrumental accessory. Further, a technical manual was written for future students and faculty in undergraduate research. Assembly involved constructing a custom frame, and integrating vacuum, water, gas, and electrical systems. Testing confirmed the system did not leak gas. Thermal response was recorded during cooling and heating phases to verify functionality; a base temperature of 7.5 K was achieved in 65 minutes, surpassing …

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Health Effects Of Cadmium And Manganese Exposure On Luteinizing Hormone Levels: A Pilot Study Of Female Infertility, Shatha F. Alhous, Anees A. Al-Hamzawi, Murtadha Sh. Aswood Mar 2026

Health Effects Of Cadmium And Manganese Exposure On Luteinizing Hormone Levels: A Pilot Study Of Female Infertility, Shatha F. Alhous, Anees A. Al-Hamzawi, Murtadha Sh. Aswood

Al-Bahir

Female infertility occurs for many reasons, some unknown. Exposure to heavy metals is a risk factor that negatively impacts on female reproductive system. Therefore, this study aimed to evaluate the effect of cadmium Cd and manganese Mn on luteinizing hormone LH levels for females’ infertility. This study included a healthy group (n = 20), primary infertile females (n = 40), and secondary infertile females (n = 20) collected from Al-Zahraa hospital in Najaf center, Iraq. The Atomic Absorption Spectroscopy (AAS) was used to measure the cadmium and manganese concentrations and LH levels were measured by a Maglumi 800 from Snibe …

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Heavy Dark Matter In Rapidly Evolving Massive Stars, Sandra Robles, Walter Tangarife, Giogio Busoni Mar 2026

Heavy Dark Matter In Rapidly Evolving Massive Stars, Sandra Robles, Walter Tangarife, Giogio Busoni

Physics: Faculty Publications and Other Works

We study the impact of heavy dark matter (DM) captured in massive stars via scattering(s) with the star constituents. We focus on the first stars and use stellar evolution simulations to track down how DM capture evolves over time from the zero-age main sequence to the late metal-rich stages of stellar evolution. During the early hydrogen-helium-dominated phase, the capture process is well described by scattering with two targets. As a star evolves, metal production leads to the formation of a dense core surrounded by a lighter envelope. The core significantly enhances the capture of ultra-heavy DM; in this case, three …

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Bicuspid Valve Closure And Backflow Prevention: Role Of Leaflet Geometry, Badr Kauoi, A Bou Orm, P Navet, James W. Baish, Lance Munn Mar 2026

Bicuspid Valve Closure And Backflow Prevention: Role Of Leaflet Geometry, Badr Kauoi, A Bou Orm, P Navet, James W. Baish, Lance Munn

Faculty Journal Articles

Bicuspid valves with crescent-shaped leaflets are found in lymphatic vessels and veins, where their primary function is to prevent reflux and ensure unidirectional flow toward the heart. These valves are passive, and their functionality emerges spontaneously from a complex interplay between the properties of the valve leaflets and the flow patterns developing within the vessel sinus region surrounding the valve. The main function of the valves is to limit retrograde flow, or reflux, but the optimal valve structure has not been well characterized. Here we investigate numerically how the length of the leaflets affects the valve efficiency in preventing reflux. …

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