UNT Scholarly Works - 587 Matching Results

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Terahertz spectroscopy of MOFs reveals dynamic structure and contact free ultrafast photoconductivity: Article describes how metal-organic frameworks (MOFs) are porous crystalline materials, and their large pores make them particularly interesting for membranes, gas separation, and gas storage. The authors discuss how gas-MOF interactions alter the MOFs' spectral fingerprints.
Influence of Tools and Cutting Strategy on Milling Conditions and Quality of Horizontal Thin-Wall Structures of Titanium Alloy Ti6Al4V: Article describes how titanium and nickel alloys are used in the creation of components exposed to harsh and variable operating conditions. The authors state that a search is underway for cutting parameters that will minimize the vibration while meeting the quality requirements.
The refractive index of a single atom experienced by a single photon: Article describes how the refractive index of a system is often viewed as the collective response of a medium to an electromagnetic field. By studying the propagation of a single photon interacting with a two-level atom, the authors examine the dispersion behavior, calculate the phase and group velocity of the photon wave packet, and further analyze the dispersion experienced by the photon.
Dominant Role of Hole Transport Pathway in Achieving Record High Photoconductivity in Two-Dimensional Metal-Organic Frameworks: Article describes how metal-organic frameworks with mobile charges have attracted significant attention due to their potential application in photoelectric devices, chemical resistance sensors, and catalysis. The authors report the mechanisms of photoinduced charge transport and electron dynamics in the conductive 2D M−HHTP MOFs and their correlation with photoconductivity using the combination of time-resolved terahertz spectroscopy, optical transient absorption spectroscopy, X-ray transient absorption spectroscopy, and density functional theory calculations.
The formation channels of multiphase gas in nearby early-type galaxies: Article describes how the processes responsible for the assembly of cold and warm gas in early-type galaxies (ETGs) are not well understood. The authors report on the multiwavelength properties of 15 non-central, nearby ETGs primary through Multi-Unit Spectroscopic Explorer (MUSE) and Chandra X-ray observations, to address the origin of their multiphase gas.
ARKENSTONE – I. A novel method for robustly capturing high specific energy outflows in cosmological simulations: Article describes how ARKENSTONE is a new model for multiphase, stellar feedback-driven galactic winds designed for inclusion in coarse resolution cosmological simulations. In this first paper of a series, the authors describe the features that allow ARKENSTONE to properly treat high specific energy wind components and demonstrate them using idealized non-cosmological simulations of a galaxy with a realistic circumgalactic medium (CGM) using the AREPO code.
Biophotons: New Experimental Data and Analysis: Article describes how biophotons are an ultra-weak emission of photons in the visible energy range from living matter. The authors study the emission from germinating seeds using an experimental technique designed to detect light of extremely small intensity.
Complexity Synchronization of Organ Networks: Article describes how the transdisciplinary nature of science as a whole became evident as the necessity for the complex nature of phenomena to explain social and life science, along with the physical sciences, blossomed into complexity theory and most recently into complexitysynchronization. The authors use the scaling of empirical datasets from the brain, cardiovascular and respiratory networks to support the hypothesis that complexity synchronization occurs between scaling indices or equivalently with the matching of the time dependencies of the networks' multifractal dimensions.
Enhanced Photoluminescence and Prolonged Carrier Lifetime through Laser Radiation Hardening and Self-Healing in Aged MAPbBr3 Perovskites Encapsulated in NiO Nanotubes: Article describes how organic-inorganic perovskites hold great promise as optoelectronic semiconductors for pure color light emitting and photovoltaic devices. This paper investigates the laser radiation hardening and self-healing-induced properties of aged MAPbBr3 perovskites encapsulated in NiO nanotubes (MAPbBr3@NiO) using photoluminescence (PL) and fluorescence lifetime imaging (FLIM). After deliberately subjecting the MAPbBr3@ NiO to atmospheric conditions for two years, the sample remains remarkably stable.
A brief guide to polymer characterization: structure (IUPAC Technical Report): Article states that to bolster the series of Brief Guides released by International Union of Pure and Applied Chemistry, the authors introduce the first Brief Guide to Polymer Characterization. This article provides a concise overview of characterization methods for teachers, students, non-specialists, and newcomers to polymer science as well as being a useful manual for researchers and technicians.
Uncoupling system and environment simulation cells for fast-scaling modeling of complex continuum embeddings: Article describes how continuum solvation models are becoming increasingly relevant in condensed matter simulations, allowing to characterize materials interfaces in the presence of wet electrified environments at a reduced computational cost with respect to all atomistic simulations. However, some challenges with the implementation of these models in plane-wave simulation packages still persists, and to address these challenges, the authors present the implementation of a double-cell formalism, in which the simulation cell used for the continuum environment is uncoupled from the one used for the electronic-structure simulation of the quantum-mechanical system.
Optical Pump Terahertz Probe (OPTP) and Time Resolved Terahertz Spectroscopy (TRTS) of emerging solar materials Editor’s Pick: Article describes how photoconductivity is the crucial benchmark to assess the potential of any emerging material for future solar applications. This tutorial aims to familiarize the reader with the main THz techniques used to explore emerging materials.
Complexity synchronization: a measure of interaction between the brain, heart and lungs: Authors of the article address the measurable consequences of the network effect (NE) on time series generated by different parts of the brain, heart, and lung organ-networks (ONs), which are directly related to their inter-network and intra-network interactions. The authors assert that these same physiologic ONs have been shown to generate crucial event (CE) time series, and herein are shown ,using modified diffusion entropy analysis (MDEA) to have scaling indices with quasiperiodic changes in complexity, as measured by scaling indices, over time.
Evaluation of the Vibration Signal during Milling Vertical Thin-Walled Structures from Aerospace Materials: Article describes how the main functions of thin-walled structures are to reduce the weight of the finished product and to increase the rigidity of the structure. The authors compared the vibration signal for different approaches to machining thin walled-components with vertical walls made of Ti6AI4V titanium alloy and Inconel 625 nickel alloy.
Code Comparison in Galaxy-scale Simulations with Resolved Supernova Feedback: Lagrangian versus Eulerian Methods: Authors of the article present a suite of high-resolution simulations of an isolated dwarf galaxy using four different hydrodynamical codes: Gizmo, Arepo, Gadget, and Ramses. They find reasonable agreement on the time-averaged star formation rates as well as the joint density–temperature distributions between all codes.
Gemini Near Infrared Spectrograph–Distant Quasar Survey: Augmented Spectroscopic Catalog and a Prescription for Correcting UV-based Quasar Redshifts: Article describes how quasars at z ≳ 1 most often have redshifts measured from rest-frame ultraviolet emission lines. One of the most common such lines, C ivλ1549, shows blueshifts up to ≈5000 km s−1 and in rare cases even higher. The authors present spectroscopic measurements for 260 sources at 1.55 ≲ z ≲ 3.50 having −28.0 ≲ Mi ≲ − 30.0 mag from the Gemini Near Infrared Spectrograph–Distant Quasar Survey (GNIRS-DQS) catalog, augmenting the previous iteration, which contained 226 of the 260 sources whose measurements are improved upon in this work.
Gemini Near Infrared Spectrograph–Distant Quasar Survey: Prescriptions for Calibrating UV-based Estimates of Supermassive Black Hole Masses in High-redshift Quasars: Article describes how the most reliable single-epoch supermassive black hole mass (MBH) estimates in quasars are obtained by using the velocity widths of low-ionization emission lines, typically the Hβλ4861 line. The authors find that utilizing both emission lines, where available, reduces the scatter of UV-based MBH estimates by ∼15% when compared to previous studies.
Holographic Fabrication of 3D Moiré Photonic Crystals Using Circularly Polarized Laser Beams and a Spatial Light Modulator: The authors of the article state that holographic fabrication of a 3D moiré photonic crystal is very difficult due to the coexistence of the bright and dark regions, where the exposure threshold is suitable for one region but not for the other. In this paper, the authors study the holographic fabrication of 3D moiré photonic crystals using an integrated system of a single reflective optical element (ROE) and a spatial light modulator (SLM) where nine beams (four inner beams + four outer beams + central beam) are overlapped.
Temporal complexity measure of reaction time series: Operational versus event time: Article describes how detrended fluctuation analysis (DFA) is a well-established method to evaluate scaling indices of time series, which categorize the dynamics of complex systems. The authors propose treating each reaction time as a duration time that changes the representation from operational (trial number) time n to event (temporal) time t, or X(t).
X-Ray Unveiling Events in a z ≈ 1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South: Authors of the article explain that they investigated the extreme X-ray variability of a z = 1.608 active galactic nucleus in the 7 Ms Chandra Deep Field-South (XID 403), which showed two significant X-ray brightening events.
The universal shape of the X-ray variability power spectrum of AGN up to z ∼ 3: Authors of the article assert that they studied the ensemble X-ray variability properties of active galactic nuclei (AGN) over large ranges of timescale (20 ks ≤ T ≤ 14 yr), redshift (0 ≤ z ≲ 3), luminosity (1040 erg s−1 ≤ LX ≤ 1046 erg s−1), and black hole (BH) mass (106 ≤ M⊙ ≤ 109). The authors show that the data collected from archival observations and previous literature studies are fully consistent with a universal PSD form, which does not show any evidence for systematic evolution of shape or amplitude with redshift or luminosity, even if there may be differences between individual AGN at a given redshift or luminosity.
Shedding New Light on Weak Emission-Line Quasars in the CIV-Hβ Parameter Space: Article describes how weak emission-line quasars (WLQs) are a subset of Type 1 quasars that exhibit extremely weak Lyα+N V λ1240 and/or C IV λ1549 emission lines. The authors investigate the relationship between emission-line properties and accretion rate for a sample of 230 `ordinary' Type 1 quasars and 18 WLQs at z<0.5 and 1.5<z<3.5 that have rest-frame ultraviolet and optical spectral measurements.
Automated Approach to In Vitro Image-Guided Photothermal Therapy with Top-Down and Bottom-Up-Synthesized Graphene Quantum Dots: Article discusses how, based on recent studies, graphene quantum dots (GQDs) are expected to possess advantageous photothermal properties and facilitate fluorescence image-tracking in the visible and near-infrared (NIR), while surpassing other graphene-based materials in their biocompatibility. The combination of the photothermal and imaging modalities tested in vitro makes the GQDs developed in this work prospective agents for cancer theragnostics.
Analyzing the Bolometric Performance of Vanadium Oxide Thin Films Modified by Carbon Nanotube Dispersions: Article investigates the influence of carbon nanotube (CNT) dispersions on the electrical properties and noise signal amplitude of 𝑉𝑂𝑥 films. The results presented in this work provide a better understanding of 𝑉𝑂𝑥-based composites, thereby enabling the development of new, versatile and functional materials for device applications.
Evolutionary models of lateralization: Steps toward stigmergy?: Article discusses an interesting approach to accounting for brain and behavioral asymmetry based on competition and cooperation in phenotypically asymmetric individuals. The model in question shows, in an almost fully analytical way, that under proper conditions, there exists an unequal number of equilibrium of left-and right-lateralized individuals.
Long-range current-induced spin accumulation in chiral crystals: Article states that chiral materials, similarly to human hands, have distinguishable right-handed and left-handed enantiomers which may behave differently in response to external stimuli, so for the first time the authors use an approach based on the density functional theory (DFT)+PAOFLOW calculations to quantitatively estimate the so-called collinear Rashba–Edelstein effect (REE) that generates spin accumulation parallel to charge current and can manifest as chirality-dependent charge-to-spin conversion in chiral crystals. The authors reveal that the spin accumulation induced in the bulk by an electric current is intrinsically protected by the quasi-persistent spin helix arising from the crystal symmetries present in chiral systems with the Weyl spin–orbit coupling.
Growth of Highly-Ordered Metal Nanoparticle Arrays in the Dimpled Pores of an Anodic Aluminum Oxide Template: Article presents a reliable, scalable, and inexpensive technology for the fabrication of ordered arrays of metal nanoparticles with large areal coverage on various substrates. Using a simple model, the experimental results were interpreted and supported by numerical estimations.
Unusual Mathematical Approaches Untangle Nervous Dynamics: Article reports that the massive amount of available neurodata suggests the existence of a mathematical backbone underlying neuronal oscillatory activities. The authors assert that the Monge’s theorem might contribute to our visual ability of depth perception and the brain connectome can be tackled in terms of tunnelling nanotubes.
Tuning the decay of sound in a viscous metamaterial: Authors of the article use analytical results for viscous dissipation in phononic crystals to calculate the decay coefficient of a sound wave propagating at low frequencies through a two-dimensional phononic crystal with a viscous fluid background. They claim that the decay coefficient exhibits dependence on the direction of propagation; that is, a homogenized phononic crystal behaves like an anisotropic viscous fluid.
Detection of Pancreatic Cancer miRNA with Biocompatible Nitrogen-Doped Graphene Quantum Dots: Article detects the presence of a specific pancreatic cancer-derived miRNA (pre-miR-132) using the fluorescence properties of biocompatible nitrogen-doped graphene quantum dots (NGQDs) synthesized using a bottom-up approach from a single glucosamine precursor. This non-invasive approach allows cancer-specific miRNA detection to facilitate early diagnosis of various forms of cancer.
Numerical Investigation of Dynamical and Morphological Trends in Relativistic Jets: Article investigates the connection of kiloparsec scale AGN jet properties to their intrinsic parameters and surroundings. This is the accepted manuscript version of the article.
An X-ray fading, UV brightening QSO at z ≈ 6: Article presents quasi-simultaneous X-ray and rest-frame UV observations of quasi-stellar object (QSO) z = 6.025 QSO J1641+3755.
Quantum algorithm for electronic band structures with local tight-binding orbitals: Article says that while the main thrust of quantum computing research in materials science is to accurately measure the classically intractable electron correlation effects due to Coulomb repulsion, designing optimal quantum algorithms for simpler problems with well-understood solutions is a useful tactic to advance our quantum “toolbox”. In this paper, the authors adopt a direct space approach, using a novel hybrid first/second-quantized qubit mapping which allows us to construct a single Hamiltonian, and a single cost-function, suitable for solving the entire electronic band structure.
Exploring Changes in Quasar Spectral Energy Distributions across C iv Parameter Space: This article examines the UV/X-ray properties of 1378 quasars in order to link empirical correlations to theoretical models of the physical mechanisms dominating quasars as a function of mass and accretion rate.
Laser Diffraction Zones and Spots from Three-Dimensional Graded Photonic Super-Crystals and Moiré Photonic Crystals: This article reports the holographic fabrication of three types of 3D graded photonic super-crystals (GPSCs) through nine beam interferences and their characteristic diffraction patterns.
Can X-Ray Observations Improve Optical-UV-based Accretion-rate Estimates for Quasars?: Article presents a study utilizing a carefully selected sample of 53 radio-quiet quasars that have Hβ and C iv λ1549 spectroscopy as well as Chandra coverage, to search for a robust accretion-rate indicator for quasars, particularly at the highest-accessible redshifts (z ∼ 6–7).
Discovery of the first heavily obscured QSO candidate at z > 6 in a close galaxy pair: This article reports the Chandra discovery of the first heavily obscured QSO candidate in the early universe, hosted by a close (≈5 kpc) galaxy pair at z = 6.515.
Momentum-Space Spin Antivortex and Spin Transport in Monolayer Pb: This article finds a nontrivial spin texture, spin antivortex, can appear at certain momenta on the Γ− K line in a 2D monolayer Pb on top of SiC.
Polymeric Coatings for Skutterudite-Based Thermoelectric Materials: Article is a study with the main objective of mitigation of thermal degradation of skutterudite-based thermoelectric materials—so as to extend the service life of those materials and make them more attractive for industry from the economical perspective. Significant mitigation of oxidation and sublimation of thermoelectric (TE) materials was achieved.
Connecting Low- and High-redshift Weak Emission-line Quasars via Hubble Space Telescope Spectroscopy of Lyα Emission: Article presents ultraviolet spectroscopy covering the Lyα + N v complex of six candidate low-redshift (0.9 < z < 1.5) weak emission-line quasars (WLQs) based on observations with the Hubble Space Telescope.
Relaxation time approximations in PAOFLOW 2.0: Article presents the implementation of relaxation time approximation models in the calculation of Boltzmann transport in PAOFLOW 2.0 and applies those to model band-structures. In addition, using a self-consistent fitting of the model parameters to experimental conductivity data, the authors provide a flexible tool to extract scattering rates with high accuracy. They illustrate the approximations using simple models and then apply the method to GaAs, Si, Mg₃Sb₂, and CoSb₃.
Two-Layer High-Throughput: Effective Mass Calculations Including Warping: Article performing and analyzing two-layer high-throughput calculations.
Optimization of the Observing Cadence for the Rubin Observatory Legacy Survey of Space and Time: A Pioneering Process of Community-focused Experimental Design: This article is part of a Focus Issue on the topic of Rubin LSST Survey Strategy Optimization. The motivation, history, and decision-making process of the observing strategy optimization are detailed, giving context to the science-driven proposals and recommendations for the survey strategy included in this Focus Issue.
The allometric propagation of COVID-19 is explained by human travel: Article develops an allometric model capable of fitting the initial phase of the COVID-19 pandemic and predicting the propagation of the illness for up to 100 days.
Ice imaging in aircraft anti-icing fluid films using polarized light: Article presents how to enhance ice contrast in the visible spectrum by using ice birefringence and polarized light reflection. The method can be used for both visual inspection and automatic ice detection systems.
Sub-Diffraction-Limit Imaging System with two Interfacing Hyperbolic Metamaterials: Article demonstrating that a system of two interfacing hyperbolic metamaterials may be used for direct subwavelength imaging in the visible range.
Cysne et al. Reply: This article is a response to a comment on the authors' original article "Disentangling Orbital and Valley Hall Effects in Bilayers of Transition Metal Dichalcogenides." The authors' response concludes that they do not believe the main points of the original Letter are affected by the Comment.
A Miniature Permanent Magnet Assembly with Localized and Uniform Field with an Application to Optical Pumping of Helium: Article using simulations and experimental measurements to design, build, and test a compact and uniform magnetic field source and then apply it to the optical pumping of atomic helium.
Photonic Band Gaps and Resonance Modes in 2D Twisted Moiré Photonic Crystal: Article studying 2D twisted moiré photonic crystals without physical rotation and simulating their photonic band gaps in photonic crystals formed at different twisted angles, different gradient levels, and different dielectric filling factors.
Simulation of the formation of antihydrogen via magnetobound positronium: This article simulates Antihydrogen formation involving magnetobound positronium by computing classical trajectories.

UNT Scholarly Works - 587 Matching Results

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