Physical Sciences and Mathematics Commons^™

On-Demand Generation Of Dark Soliton Trains In Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, P. G. Kevrekidis, B. Prinari, G. Biondini, P. Schmelcher

Physics Faculty Research & Creative Works

Matter-wave interference mechanisms in one-dimensional Bose-Einstein condensates that allow for the controlled generation of dark soliton trains upon choosing suitable box-type initial configurations are described. First, the direct scattering problem for the defocusing nonlinear Schrödinger equation with nonzero boundary conditions and general box-type initial configurations is discussed, and expressions for the discrete spectrum corresponding to the dark soliton excitations generated by the dynamics are obtained. It is found that the size of the initial box directly affects the number, size and velocity of the solitons, while the initial phase determines the parity of the solutions. The analytical results obtained for …

Pattern Formation Of Correlated Impurities Subjected To An Impurity-Medium Interaction Pulse, G. Bougas, Simeon I. Mistakidis, P. Schmelcher

Physics Faculty Research & Creative Works

We Study The Correlated Dynamics Of Few Interacting Bosonic Impurities Immersed In A One-Dimensional Harmonically Trapped Bosonic Environment. The Mixture Is Exposed To A Time-Dependent Impurity-Medium Interaction Pulse Moving It Across The Relevant Phase-Separation Boundary. For Modulation Frequencies Smaller Than The Trapping One, The System Successively Transits Through The Miscible And Immiscible Phases According To The Driving Of The Impurity-Medium Interactions. For Strong Modulations, And Driving From The Miscible To The Immiscible Regime, A Significant Fraction Of The Impurities Is Expelled To The Edges Of The Bath. They Exhibit A Strong Localization Behavior And Tend To Equilibrate. Following The Reverse …

Characterization And Oil Recovery Enhancement By A Polymeric Nanogel Combined With Surfactant For Sandstone Reservoirs, Mustafa Mohammed Almahfood, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The characterization and enhanced oil recovery mechanisms of a nanosized polymeric cross-linked gel are presented herein. A negatively charged nanogel was synthesized using a typical free radical suspension polymerization process by employing 2-acrylamido 2-methyl propane sulfonic acid monomer. The synthesized nanogel showed a narrow size distribution with one peak pointing to a predominant homogeneous droplet size. The charged nanogels were also able to adsorb at the oil-water interfaces to reduce interfacial tension and stabilize oil-in-water emulsions, which ultimately improved the recovered oil from hydrocarbon reservoirs. In addition, a fixed concentration of negatively charged surfactant (sodium dodecyl sulfate or SDS) was …

Photoelectron Sheath Near The Lunar Surface: Fully Kinetic Modeling And Uncertainty Quantification Analysis, Jianxun Zhao, Xinpeng Wei, Zhangli Hu, Xiaoming He, Daoru Frank Han, Zhen Hu, Xiaoping Du

Mathematics and Statistics Faculty Research & Creative Works

This paper presents a modeling and uncertainty quantification (UQ) study of the photoelectron sheath near the lunar surface. A fully kinetic 3-D finite-difference (FD) particle-in-cell (PIC) code is utilized to simulate the plasma interaction near the lunar surface and the resulting photoelectron sheath. For the uncertainty quantification analysis, this FD-PIC code is treated as a black box providing high-fidelity quantities of interest, which are also used to construct efficient reduced-order models to perform UQ analysis. 1-D configuration is chosen to present the analytic sheath solution as well as to demonstrate the procedure and capability of the UQ analysis.

Coating Compositions And Methods For Using The Same, Fateme Rezaei, Thomas P. Schuman, Glenn Morrison

Chemical and Biochemical Engineering Faculty Research & Creative Works

Coating compositions and methods for using the same are disclosed. The coating compositions can include an aminosilica adsorbent. The coating compositions can adsorb CO₂.

Fully-Kinetic Particle-In-Cell Simulations Of Photoelectron Sheath On Uneven Lunar Surface, Jianxun Zhao, Xinpeng Wei, Xiaoming He, Daoru Frank Han, Xiaoping Du

Mathematics and Statistics Faculty Research & Creative Works

This paper presents a modeling and simulation study of the photoelectron sheath near uneven lunar surface. A fully kinetic 3-D finite-difference (FD) particle-in-cell (PIC) code is utilized to simulate the plasma interaction with local uneven surface terrain on the lunar surface in 2-D photoelectron sheaths. The code is first validated using a 1-D plasma charging and sheath problem by comparing with a semi-analytic solution. Good agreement is obtained. The 2-D FD-PIC simulations present the distributions of electric potential and charged species densities near the uneven lunar surface. It shows that the surface potential is highly influenced by the exposure to …

Collisional Excitation Of Interstellar Pn By H₂: New Interaction Potential And Scattering Calculations, Benjamin Desrousseaux, Ernesto Quintas-Sánchez, Richard Dawes, Sarantos Marinakis, François Lique

Chemistry Faculty Research & Creative Works

Rotational excitation of interstellar PN molecules induced by collisions with H₂ is investigated. We present the first ab initio four-dimensional potential energy surface (PES) for the PN-H₂ van der Waals system. The PES was obtained using an explicitly correlated coupled cluster approach with single, double, and perturbative triple excitations [CCSD(T)-F12b]. The method of interpolating moving least squares was used to construct an analytical PES from these data. The equilibrium structure of the complex was found to be linear, with H₂ aligned at the N end of the PN molecule, at an intermolecular separation of 4.2 Å. The …

Using Circular Dichroism To Control Energy Transfer In Multiphoton Ionization, A. H. N. C. De Silva, D. Atri-Schuller, Daniel Fischer, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Chirality causes symmetry breaks in a large variety of natural phenomena ranging from particlephysics to biochemistry. We investigate one of the simplest conceivable chiral systems, a laser-excited, oriented, effective one-electron Li target. Prepared in a polarized p state with |m|= 1 in an optical trap, the atoms are exposed to co- and counterrotating circularly polarized femtosecond laser pulses. For a field frequency near the excitation energy of the oriented initial state, a strongcircular dichroism is observed and the photoelectron energies are significantly affected by the helicity-dependent Autler-Townes splitting. Besides its fundamental relevance, this system is suited to create spin-polarized electron …

Biochemical Characterization Of The Two-Component Flavin-Dependent Monooxygenase Involved In Valanimycin Biosynthesis, Hao Li, Benedicta Forson, Meital Eckshtain-Levi, Hannah Valentino, Julia S. Martín Del Campo, John J. Tanner, Pablo Sobrado

Chemistry Faculty Research & Creative Works

The flavin reductase (FRED) and isobutyl amine N-hydroxylase (IBAH) from Streptomyces viridifaciens constitute a two-component, flavin-dependent monooxygenase system that catalyzes the first step in valanimycin biosynthesis. FRED is an oxidoreductase that provides the reduced flavin to IBAH, which then catalyzes the hydroxylation of isobutyl amine (IBA) to isobutyl hydroxylamine (IBHA). In this work, we used several complementary methods to investigate FAD binding, steady-state and rapid reaction kinetics, and enzyme-enzyme interactions in the FRED: IBAH system. The affinity of FRED for FADox is higher than its affinity for FADred, consistent with its function as a flavin reductase. Conversely, IBAH binds FADred …

Concentrated Lunar Resources: Imminent Implications For Governance And Justice, Martin Elvis, Alanna Krolikowski, Tony Milligan

History and Political Science Faculty Research & Creative Works

Numerous missions planned for the next decade are likely to target a handful of small sites of interest on the Moon's surface, creating risks of crowding and interference at these locations. The Moon presents finite and scarce areas with rare topography or concentrations of resources of special value. Locations of interest to science, notably for astronomy, include the Peaks of Eternal Light, the coldest of the cold traps and smooth areas on the far side. Regions richest in physical resources could also be uniquely suited to settlement and commerce. Such sites of interest are both few and small. Typically, there …

Unsteady-State Contact Angle Hysteresis During Droplet Oscillation In Capillary Pores: Theoretical Model And Vof Simulation -- Supporting Information, Chao Zeng, Wen Deng, Lichun Wang

Research Data

Contact angle hysteresis (CAH) is a critical phenomenon that could significantly affect the fate of immiscible bubbles/droplets in vadose zones, nonaqueous phase liquid contaminated aquifers, and saline aquifers for CO₂ sequestration in terms of infiltration patterns and residual trapping mechanisms. When external physical impacts such as oscillatory excitation or pulse forcing are applied, it could result in pinned oscillation of droplets due to this CAH. Conventional steady-state analysis of contact angle could underestimate CAH. As the first time to take unsteady-state effect into consideration, a hydrodynamic analysis is developed in this study to address the unsteady-state CAH theoretically, and …

Stokes-Darcy System, Small-Darcy-Number Behaviour And Related Interfacial Conditions, Wenqi Lyu, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

We show that the Stokes-Darcy system, which governs flows through adjacent porous and pure-fluid domains in the two-domain approach without forced filtration, can be recovered from the Helmholtz minimal dissipation principle. While the continuity of normal velocity across the interface is imposed explicitly for mass conservation, only the Beavers-Joseph-Saffman-Jones (BJSJ) interface boundary condition is imposed implicitly, and the balance of the normal-force interface boundary condition appears naturally in the variational process. This set of interface boundary conditions is well-accepted in the mathematics community. We show that these interfacial boundary conditions, at the physically important small-Darcy-number regime, are consistent with continuity …

Stress-State Dependency Of The Deformation Ratio Of Quasi-Elastic Granular Soils Under Cyclic Loading -- Supporting Information, Pingxin Xia, Longtan Shao, Wen Deng

Research Data

Poisson’s ratio, besides its transverse-axial strain ratio definition, also plays a significant role in traditional elastic theory as an elastic constant. However, this elastic role of Poisson’s ratio faces a challenge when applied to quasi-elastic granular soils. A so-called “deformation ratio” is therefore introduced and measured in this paper for quasi-elastic granular soils. With the same definition of the transverse-axial strain ratio as Poisson’s ratio, the stress-state dependency of the deformation ratio and the break-down of conversion relationship of elastic constants are investigated under cyclic triaxial tests. The results show that Poisson’s ratio is consistent with deformation ratio only in …

Unsteady-State Contact Angle Hysteresis During Droplet Oscillation In Capillary Pores: Theoretical Model And Vof Simulation -- Data, Chao Zeng, Wen Deng, Lichun Wang

Unsteady-State Contact Angle Hysteresis during Droplet Oscillation in Capillary Pores: Theoretical Model and VOF Simulation -- Data

Spreadsheet - Data of Figures 2 through 11.

Supporting information

Open Data From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software.

Preparation Of Green Biosorbent Using Rice Hull To Preconcentrate, Remove And Recover Heavy Metal And Other Metal Elements From Water, Yongbo Dan, Lei Xu, Zhimin Qiang, Huiyu Dong, Honglan Shi

Chemistry Faculty Research & Creative Works

Sodium hydroxide treated rice hulls were investigated to preconcentrate, remove, and recover metal ions including Be²⁺, Al³⁺, Cr³⁺, CO²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Sr²⁺, Ag⁺, Cd²⁺, Ba²⁺, and Pb²⁺ in both batch mode and column mode. Sodium hydroxide treatment significantly improved the removal efficiency for all metal ions of interest compared to the untreated rice hull. The removal kinetics were extremely fast for Co, Ni, Cu, Zn, Sr, Cd, and Ba, which made the treated rice hull a …

Visualization As A Service For Scientific Data, David Pugmire, James Kress, Jieyang Chen, Hank Childs, Jong Choi, Dmitry Ganyushin, Berk Geveci, Mark Kim, Scott Klasky, Xin Liang, For Full List Of Authors, See Publisher's Website.

Computer Science Faculty Research & Creative Works

One of the primary challenges facing scientists is extracting understanding from the large amounts of data produced by simulations, experiments, and observational facilities. The use of data across the entire lifetime ranging from real-time to post-hoc analysis is complex and varied, typically requiring a collaborative effort across multiple teams of scientists. Over time, three sets of tools have emerged: One set for analysis, another for visualization, and a final set for orchestrating the tasks. This trifurcated tool set often results in the manual assembly of analysis and visualization workflows, which are one-off solutions that are often fragile and difficult to …

Your 'Attention' Deserves Attention: A Self-Diversified Multi-Channel Attention For Facial Action Analysis, Xiaotian Li, Zhihua Li, Huiyuan Yang, Geran Zhao, Lijun Yin

Computer Science Faculty Research & Creative Works

Visual attention has been extensively studied for learning fine-grained features in both facial expression recognition (FER) and Action Unit (AU) detection. A broad range of previous research has explored how to use attention modules to localize detailed facial parts (e, g. facial action units), learn discriminative features, and learn inter-class correlation. However, few related works pay attention to the robustness of the attention module itself. Through experiments, we found neural attention maps initialized with different feature maps yield diverse representations when learning to attend the identical Region of Interest (ROI). In other words, similar to general feature learning, the representational …

Exploiting Semantic Embedding And Visual Feature For Facial Action Unit Detection, Huiyuan Yang, Lijun Yin, Yi Zhou, Jiuxiang Gu

Computer Science Faculty Research & Creative Works

Recent study on detecting facial action units (AU) has utilized auxiliary information (i.e., facial landmarks, relationship among AUs and expressions, web facial images, etc.), in order to improve the AU detection performance. As of now, no semantic information of AUs has yet been explored for such a task. As a matter of fact, AU semantic descriptions provide much more information than the binary AU labels alone, thus we propose to exploit the Semantic Embedding and Visual feature (SEV-Net) for AU detection. More specifically, AU semantic embeddings are obtained through both Intra-AU and Inter-AU attention modules, where the Intra-AU attention module …

Multimodal Learning For Hateful Memes Detection, Yi Zhou, Zhenhao Chen, Huiyuan Yang

Computer Science Faculty Research & Creative Works

Memes are used for spreading ideas through social networks. Although most memes are created for humor, some memes become hateful under the combination of pictures and text. Automatically detecting hateful memes can help reduce their harmful social impact. Compared to the conventional multimodal tasks, where the visual and textual information is semantically aligned, hateful memes detection is a more challenging task since the image and text in memes are weakly aligned or even irrelevant. Thus, it requires the model to have a deep understanding of the content and perform reasoning over multiple modalities. This paper focuses on multimodal hateful memes …

A Deep Learning Model To Predict Traumatic Brain Injury Severity And Outcome From Mr Images, Dacosta Yeboah, Hung Nguyen, Daniel B. Hier, Gayla R. Olbricht, Tayo Obafemi-Ajayi

Chemistry Faculty Research & Creative Works

For Many Neurological Disorders, Including Traumatic Brain Injury (TBI), Neuroimaging Information Plays a Crucial Role Determining Diagnosis and Prognosis. TBI is a Heterogeneous Disorder that Can Result in Lasting Physical, Emotional and Cognitive Impairments. Magnetic Resonance Imaging (MRI) is a Non-Invasive Technique that Uses Radio Waves to Reveal Fine Details of Brain Anatomy and Pathology. Although MRIs Are Interpreted by Radiologists, Advances Are Being Made in the Use of Deep Learning for MRI Interpretation. This Work Evaluates a Deep Learning Model based on a Residual Learning Convolutional Neural Network that Predicts TBI Severity from MR Images. the Model Achieved a …

Schizophrenia Classification Using Resting State Eeg Functional Connectivity: Source Level Outperforms Sensor Level, Sima Azizi, Daniel B. Hier, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Disrupted Functional and Structural Connectivity Measures Have Been Used to Distinguish Schizophrenia Patients from Healthy Controls. Classification Methods based on Functional Connectivity Derived from EEG Signals Are Limited by the Volume Conduction Problem. Recorded Time Series at Scalp Electrodes Capture a Mixture of Common Sources Signals, Resulting in Spurious Connections. We Have Transformed Sensor Level Resting State EEG Times Series to Source Level EEG Signals Utilizing a Source Reconstruction Method. Functional Connectivity Networks Were Calculated by Computing Phase Lag Values between Brain Regions at Both the Sensor and Source Level. Brain Complex Network Analysis Was Used to Extract Features and …

Subsumption Reduces Dataset Dimensionality Without Decreasing Performance Of A Machine Learning Classifier, Donald C. Wunsch, Daniel B. Hier

Chemistry Faculty Research & Creative Works

When Features in a High Dimension Dataset Are Organized Hierarchically, There is an Inherent Opportunity to Reduce Dimensionality. Since More Specific Concepts Are Subsumed by More General Concepts, Subsumption Can Be Applied Successively to Reduce Dimensionality. We Tested Whether Sub-Sumption Could Reduce the Dimensionality of a Disease Dataset Without Impairing Classification Accuracy. We Started with a Dataset that Had 168 Neurological Patients, 14 Diagnoses, and 293 Unique Features. We Applied Subsumption Repeatedly to Create Eight Successively Smaller Datasets, Ranging from 293 Dimensions in the Largest Dataset to 11 Dimensions in the Smallest Dataset. We Tested a MLP Classifier on All …

Robustness Against Attacks And Uncertainties In Smart Cyber-Physical Systems, Prithwiraj Roy

Doctoral Dissertations

Cyber-Physical Systems (CPS) are sensing, processing, and communicating platforms, embedded with physical devices that provide real-time monitoring and control. Security challenges in CPS necessitate solutions that are robust against attacks and uncertainties and provide a seamless operation, especially when used in real-time applications to monitor and secure critical infrastructures. CPS mainly consists of a physical component for sensing or monitoring and a cyber component for processing and communicating. The quality of interactions between physical and cyber systems has direct impacts on the system’s performance and reliability.

CPS plays a major role in smart services and applications within a smart living …

Development Of Intelligent Stimuli-Responsive Biomaterials And Nanodevices, Shuo Yang

Doctoral Dissertations

"Structural DNA nanotechnology utilizes DNA molecules as building blocks to fabricate ordered artificial nanostructures at the molecular level. Among all DNA-based techniques, DNA origami has been considered as one of the most powerful tools for constructing artificial nanostructures with excellent programmability and addressability. Currently, most DNA origami nanostructures are static and do not have the ability to response to environmental stimulation. The development of environmental-responsive DNA origami nanostructures is a critical step towards the realization of intelligent dynamic DNA origami-based nanodevices. This research focuses on the design and fabrication process of both static and dynamic DNA origami nanostructures and their …

Laser-Induced Electron Diffraction Of The Ultrafast Umbrella Motion In Ammonia, B. Belsa, K. Amini, X. Liu, A. Sanchez, J. Steinmetzer, Anh-Thu Le, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, …

Neogene Dinoflagellate Cysts From The Tropical Americas, Damian Cardenas

Doctoral Dissertations

"Marine palynomorphs, mainly dinoflagellate cysts and acritarchs, constitute excellent proxies for biostratigraphic and paleoceanographic studies in neritic sequences. Neogene marine palynological studies have mostly focused on the Northern Hemisphere, resulting in the scarcity of dinoflagellate cysts and acritarchs from tropical latitudes. Forty samples encompassing the late Chattian-late Burgidalian time interval (~24.1- 17.3 Ma) in the Southern Caribbean were analyzed for their marine palynological contents. A biostratigraphic scheme for the region is proposed and includes the upper Chattian-lower Aquitanian Minisphaeridium latirictum Interval Zone (~23.9-22.0 Ma), the upper Aquitanian Achomosphaera alcicornu Interval Zone (~22.0-20.3 Ma), and the Burdigalian Cribroperidinium tenuitabulatum Interval Zone …

Proper Orthogonal Decomposition: New Approximation Theory And A New Computational Approach, Sarah Katherine Locke

Doctoral Dissertations

“Proper orthogonal decomposition (POD) projection errors and error bounds for POD reduced order models of partial differential equations have been studied by many. In this research we obtain new results regarding POD data approximation theory and present a new difference quotient (DQ) approach for computing the POD modes of the data.

First, we improve on earlier results concerning POD projection errors by extending to a more general framework that allows for non-orthogonal POD projections and seminorms. We obtain new exact error formulas and convergence results for POD data approximation errors, and also prove new pointwise convergence results and error bounds …

Exposure Assessment Of Emerging Contaminants: Rapid Screening And Modeling Of Plant Uptake, Majid Bagheri

Doctoral Dissertations

"With the advent of new chemicals and their increasing uses in every aspect of our life, considerable number of emerging contaminants are introduced to environment yearly. Emerging contaminants in forms of pharmaceuticals, detergents, biosolids, and reclaimed wastewater can cross plant roots and translocate to various parts of the plants. Long-term human exposure to emerging contaminants through food consumption is assumed to be a pathway of interest. Thus, uptake and translocation of emerging contaminants in plants are important for the assessment of health risks associated with human exposure to emerging contaminants. To have a better understanding over fate of emerging contaminants …

Spatiotemporal Variations Of Upper Crustal Anisotropy Along The San Jacinto Fault Zone In Southern California And The Fairview Region In Central Oklahoma, Enyuan Jiang

Doctoral Dissertations

"To discern spatial and explore the possible existence of temporal variations of upper crustal anisotropy along an ~15 km section of the San Jacinto Fault Zone (SJFZ) in California, and in the Fairview, Oklahoma, region, we conduct systematic shear wave splitting (SWS) investigations using local S-wave data recorded by seismic stations. Strong spatial variations in crustal anisotropy are revealed by 1694 and 405 pairs of splitting parameters (including the fast polarization orientation and the splitting time), respectively. For both areas, for raypaths traveling through the fault zones, the fast orientations are parallel to the faults and may be attributed to …