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ALMA Observations of Quasar Host Galaxies at z ≃ 4.8 (open access)

ALMA Observations of Quasar Host Galaxies at z ≃ 4.8

Article presents ALMA Band 7 data of the [C ıı] 𝜆157.74 𝜇m emission line and underlying far-IR (FIR) continuum for 12 luminous quasars at 𝓏 ≃ 4.8 powered by fast-growing supermassive black holes (SMBHs).
Date: May 27, 2020
Creator: Shemmer, Ohad; Nguyen, Nathen H.; Lira, Paulina; Trakhtenbrot, Benny; Netzer, Hagai; Cicone, Claudia et al.
System: The UNT Digital Library
Anisotropic Optical Properties of 2D Silicon Telluride (open access)

Anisotropic Optical Properties of 2D Silicon Telluride

Article reports an ab initio computational study of the optical dielectric properties of Silicon telluride (Si2Te3) using the GW approximation and the Bethe-Salpeter equation (BSE).
Date: September 27, 2020
Creator: Cui, Jingbiao; Bhattarai, Romakanta; Chen, Jiyang; Hoang, Thang B. & Shen, Xiao
System: The UNT Digital Library
Anisotropic optical properties of single Si2Te3 nanoplates (open access)

Anisotropic optical properties of single Si2Te3 nanoplates

Article reporting a combined experimental and computational study of the optical properties of individual silicon telluride (Si2Te3) nanoplates.
Date: November 5, 2020
Creator: Chen, Jiyang; Bhattarai, Romakanta; Cui, Jingbiao; Shen, Xiao & Hoang, Thang
System: The UNT Digital Library
Closed-form expressions for the magnetic fields of rectangular and circular finite-length solenoids and current loops (open access)

Closed-form expressions for the magnetic fields of rectangular and circular finite-length solenoids and current loops

This article discusses closed-form expressions for the magnetic fields produced by rectangular- and circular-shaped finite-length solenoids and current loops. The closed-form expression for the magnetic field of a rectangular-shaped finite-length solenoid is derived using the Biot–Savart law. Closed-form expressions for the magnetic fields of solenoids and current loops can be used to avoid approximations in analytical models and may reduce computation time in computer simulations.
Date: June 15, 2020
Creator: Hampton, S.; Lane, R. A.; Hedlof, R. M.; Phillips, R. E. & Ordonez, Carlos A.
System: The UNT Digital Library
Deep Minima in the Triply Differential Cross Section for Ionization of Atomic Hydrogen by Electron and Positron Impact (open access)

Deep Minima in the Triply Differential Cross Section for Ionization of Atomic Hydrogen by Electron and Positron Impact

Article investigating ionization of atomic hydrogen by electron- and positron-impact. This article belongs to the Special Issue: Interactions of Positrons with Matter and Radiation.
Date: May 29, 2020
Creator: DeMars, C. M.; Ward, S. J.; Colgan, J.; Amami, S. & Madison, D. H.
System: The UNT Digital Library
Development of a Thulium Fiber Laser for an Atomic Spectroscopy Experiment (open access)

Development of a Thulium Fiber Laser for an Atomic Spectroscopy Experiment

This article is a simplified analysis of a convenient thulium fiber laser source with 3 W of output power operating at a wavelength of 2059 nm with a slope efficiency of 49% with respect to input pump power and 60% with respect to absorbed pump power. The laser was applied in an atomic helium spectroscopy experiment to quench ³He (2058.63 nm) and ⁴He (2058.69 nm) meta-stable singlets (2¹S0), allowing for further investigation of the helium fine structure.
Date: February 15, 2020
Creator: Currey, Ronnie; Khademian, Ali & Shiner, David
System: The UNT Digital Library
Dielectric function of six elemental metals (open access)

Dielectric function of six elemental metals

This article presents an accurate first-principles study of the electronic structure and absorption spectrum of six elemental metals (aluminium, gold, silver, copper, palladium, platinum) using density functional theory in an all-electron full-potential framework.
Date: December 2020
Creator: Pogodaeva, Maria K.; Levchenko, Sergey; Drachev, Vladimir P. & Gabitov, Ildar R.
System: The UNT Digital Library
An Extreme X-Ray Variability Event of a Weak-line Quasar (open access)

An Extreme X-Ray Variability Event of a Weak-line Quasar

Article reports the discovery of an extreme X-ray flux rise (by a factor of ≳20) of the weak-line quasar Sloan Digital Sky Survey (SDSS) J153913.47+395423.4 (hereafter SDSS J1539+3954) at z = 1.935. SDSS J1539+3954 is the most-luminous object among radio-quiet type 1 active galactic nuclei (AGNs) where such dramatic X-ray variability has been observed.
Date: February 3, 2020
Creator: Ni, Q.; Brandt, W. N.; Yi, W.; Luo, B.; Timlin, J. D., III; Hall, P. B. et al.
System: The UNT Digital Library
Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals (open access)

Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals

Discusses a project in which researchers were able to generate over 1000 diffraction spots from a graded photonic super-crystal with a unit super-cell size of 12a × 12a where a is the lattice constant and hole radii are gradually changed in dual directions.
Date: April 10, 2020
Creator: Hassan, Safaa; Jiang, Yan; Alnasser, Khadijah; Hurley, Noah; Zhang, Hualiang; Philipose, Usha et al.
System: The UNT Digital Library
High-Throughput Computational Search for Half-Metallic Oxides (open access)

High-Throughput Computational Search for Half-Metallic Oxides

The article describes a high-throughput computational search for half-metallic compounds. The analysis of calculated electronic properties of thousands of materials from the inorganic crystal structure database allowed the authors to identify potential half metals. They found over two-hundred strong half-metallic oxides; several of them have never been reported before.
Date: April 25, 2020
Creator: Liyanage, Laalitha S. I.; Slawińska, Jagoda; Gopal, Priya; Curtarolo, Stefano; Fornari, Marco & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Long-range nonspreading propagation of sound beam through periodic layered structure (open access)

Long-range nonspreading propagation of sound beam through periodic layered structure

Article analyzing dispersion of sound in a solid-fluid layered structure and found a flex point on the isofrequency curve where D vanishes for given direction of propagation and frequency. Nonspreading propagation is experimentally observed in a water steel lattice of 75 periods (~1 meter long) and occurs in the regime of anomalous dispersion and strong acoustic anisotropy when the effective mass along periodicity is close to zero. Under these conditions the incoming beam experiences negative refraction of phase velocity leading to backward wave propagation. The observed effect is explained using a complete set of dynamical equations and our effective medium theory.
Date: September 2, 2020
Creator: Zubov, Yurii; Djafari-Rouhani, Bahram; Jin, Yuqi; Sofield, Mathew; Walker, Ezekiel; Neogi, Arup et al.
System: The UNT Digital Library
Longitudinal Monostatic Acoustic Effective Bulk Modulus and Effective Density Evaluation of Underground Soil Quality: A Numerical Approach (open access)

Longitudinal Monostatic Acoustic Effective Bulk Modulus and Effective Density Evaluation of Underground Soil Quality: A Numerical Approach

This article introduces a novel method using longitudinal sound to detect underground soil voids to inspect underwater bed property in terms of effective bulk modulus and effective density of the material properties.
Date: December 25, 2020
Creator: Jin, Yuqi; Choi, Tae-Youl & Neogi, Arup
System: The UNT Digital Library
Magnetic confinement of effectively unmagnetized plasma particles (open access)

Magnetic confinement of effectively unmagnetized plasma particles

Article develops a planar model for an artificially structured boundary that may provide magnetic confinement of nonmagnetically trapped plasma particles.
Date: December 1, 2020
Creator: Ordonez, Carlos A.
System: The UNT Digital Library
Manufacturing and Characterization of Hybrid Bulk Voxelated Biomaterials Printed by Digital Anatomy 3D Printing (open access)

Manufacturing and Characterization of Hybrid Bulk Voxelated Biomaterials Printed by Digital Anatomy 3D Printing

This article proposes non-destructive ultrasound effective density and bulk modulus imaging to evaluate 3D voxelated materials printed by J750 Digital Anatomy 3D Printer of Stratasys. This method provides the design map of voxelated materials and substantially broadens the applications of 3D digital printing in the clinical research area.
Date: December 30, 2020
Creator: Heo, Hyeonu; Jin, Yuqi; Yang, David; Wier, Christopher; Minard, Aaron; Dahotre, Narendra B. et al.
System: The UNT Digital Library
Multitask deep-learning-based design of chiral plasmonic metamaterials (open access)

Multitask deep-learning-based design of chiral plasmonic metamaterials

This article presents an end-to-end functional bidirectional deep-learning (DL) model for three-dimensional chiral metamaterial design and optimization. This ML model utilizes multitask joint learning features to recognize, generalize, and explore in detail the nontrivial relationship between the metamaterials’ geometry and their chiroptical response, eliminating the need for auxiliary networks or equivalent approaches to stabilize the physically relevant output. This model efficiently realizes both forward and inverse retrieval tasks with great precision, offering a promising tool for iterative computational design tasks in complex physical systems. Other potential applications include photodetectors, polarization-resolved imaging, and circular dichroism (CD) spectroscopy.
Date: July 1, 2020
Creator: Ashalley, Eric; Acheampong, Kingsley; Besteiro, Lucas V.; Yu, Peng; Neogi, Arup; Govorov, Alexander O. et al.
System: The UNT Digital Library
Novel 2D Dynamic Elasticity Maps for Inspection of Anisotropic Properties in Fused Deposition Modeling Objects (open access)

Novel 2D Dynamic Elasticity Maps for Inspection of Anisotropic Properties in Fused Deposition Modeling Objects

Article introducing a novel ultrasonic non-destructive and non-invasive elastography method demonstrated to evaluate the mechanical properties of fused deposition modeling 3D printed objects using two-dimensional dynamical elasticity mapping. Based on the recently investigated dynamic bulk modulus and effective density imaging technique, an angle-dependent dynamic shear modulus measurement was performed to extract the dynamic Young’s modulus distribution of the FDM structures. The elastographic image analysis demonstrated the presence of anisotropic dynamic shear modulus and dynamic Young’s modulus existing in the fused deposition modeling 3D printed objects. The non-destructive method also differentiated samples with high contrast property zones from that of low contrast property regions. The angle-dependent elasticity contrast behavior from the ultrasonic method was compared with conventional and static tensile tests characterization. A good correlation between the nondestructive technique and the tensile test measurements was observed.
Date: August 30, 2020
Creator: Jin, Yuqi; Yang, Teng; Heo, Hyeonu; Krokhin, Arkadii A.; Shi, Sheldon; Dahotre, Narendra B. et al.
System: The UNT Digital Library
Phononic crystal as a homogeneous viscous metamaterial (open access)

Phononic crystal as a homogeneous viscous metamaterial

Article develops a homogenization theory, representing the low-frequency limit for a phononic crystal of cylinders embedded in a viscous fluid.
Date: June 8, 2020
Creator: Krokhin, Arkadii A.; Zubov, Yu.; Ibarias, M. & Arriaga, J.
System: The UNT Digital Library
Prescriptions for Correcting Ultraviolet-based Redshifts for Luminous Quasars at High Redshift (open access)

Prescriptions for Correcting Ultraviolet-based Redshifts for Luminous Quasars at High Redshift

This article presents near-infrared spectroscopy of 18 luminous quasars at 2.15 < z < 3.70 that allows the authors to obtain reliable systemic redshifts for these sources.
Date: April 8, 2020
Creator: Dix, Cooper; Shemmer, Ohad; Brotherton, Michael S.; Green, Richard F.; Mason, Michelle & Myers, Adam D.
System: The UNT Digital Library
A resonant single frequency molecular detector with high sensitivity and selectivity for gas mixtures (open access)

A resonant single frequency molecular detector with high sensitivity and selectivity for gas mixtures

Article theoretically demonstrates a single low frequency gas detector that can be used for sensing of gas mixtures with high selectivity, accuracy, and sensitivity.
Date: January 30, 2020
Creator: Branković, Zorica & Rostovtsev, Yuri V.
System: The UNT Digital Library
Role of quantum confinement and interlayer coupling in CrI3-graphene magnetic tunnel junctions (open access)

Role of quantum confinement and interlayer coupling in CrI3-graphene magnetic tunnel junctions

Article presents a combination of first principles and quantum ballistic transport calculations to shed important insights from an atomistic viewpoint on the underlying mechanisms governing spin transport in graphene/ CrI₃ junctions.
Date: May 29, 2020
Creator: Buongiorno Nardelli, Marco; Heath, Jonathan J.; Costa, Marcio & Kuroda, Marcelo A.
System: The UNT Digital Library
Single-Step Photochemical Formation of Near-Infrared-Absorbing Gold Nanomosaic within PNIPAm Microgels: Candidates for Photothermal Drug Delivery (open access)

Single-Step Photochemical Formation of Near-Infrared-Absorbing Gold Nanomosaic within PNIPAm Microgels: Candidates for Photothermal Drug Delivery

Article demonstrating the dynamic potential for tailoring the surface plasmon resonance (SPR), size, and shapes of gold nanoparticles (AuNPs) starting from an Au(I) precursor, chloro(dimethyl sulfide)gold (I) (Au(Me2S)Cl), in lieu of the conventional Au(III) precursor hydrogen tetrachloroaurate (III) hydrate (HAuCl4). This approach presents a one-step method that permits regulation of an Au(I) precursor to form either visible-absorbing gold nanospheres or near-infrared-window (NIRW)-absorbing anisotropic AuNPs.
Date: May 18, 2020
Creator: Marpu, Sreekar; Kamras, Brian; Nasiri, Nooshin Mirza; Elbjeirami, Oussama; Simmons, Denise Perry; Hu, Zhibing et al.
System: The UNT Digital Library
Spatial Decomposition of a Broadband Pulse Caused by Strong Frequency Dispersion of Sound in Acoustic Metamaterial Superlattice (open access)

Spatial Decomposition of a Broadband Pulse Caused by Strong Frequency Dispersion of Sound in Acoustic Metamaterial Superlattice

This article uses an acoustic metamaterial superlattice for the spatial and spectral deconvolution of a broadband acoustic pulse into narrowband signals with different central frequencies.
Date: December 30, 2020
Creator: Jin, Yuqi; Zubov, Yurii; Yang, Teng; Choi, Tae-Youl; Krokhin, Arkadii A. & Neogi, Arup
System: The UNT Digital Library
Spin Hall effect in prototype Rashba ferroelectrics GeTe and SnTe (open access)

Spin Hall effect in prototype Rashba ferroelectrics GeTe and SnTe

Article describes study investigating spin Hall effect (SHE) in two prototypical Ferroelectric Rashba semiconductors (FERSCs), GeTe and SnTe, and show that it can be large either in ferroelectric or paraelectric structure.
Date: January 24, 2020
Creator: Wang, Haihang; Gopal, Priya; Picozzi, Silvia; Curtarolo, Stefano; Buongiorno Nardelli, Marco & Sławińska, Jagoda
System: The UNT Digital Library
Sub-wavelength lateral detection of tissue-approximating masses using an ultrasonic metamaterial lens (open access)

Sub-wavelength lateral detection of tissue-approximating masses using an ultrasonic metamaterial lens

Article demonstrating a phononic metamaterial lens (ML) for detection of laterally subwavelength object features in tissue-like phantoms beyond the phononic crystal evanescent zone and Fresnel zone of the emitter.
Date: November 24, 2020
Creator: Walker, Ezekiel; Jin, Yuqi; Reyes, Delfino & Neogi, Arup
System: The UNT Digital Library