Digital Commons Network^™

Rab7 Deficiency Impairs Pulmonary Artery Endothelial Function And Promotes Pulmonary Hypertension, Bryce Piper, Srimathi Bogamuwa, Tanvir Hossain, Daniela Farkas, Lorena Rosas, Adam C. Green, Geoffrey Newcomb, Nuo Sun, Jose A. Ovando-Ricardez, Jeffrey C. Horowitz, Aneel R. Bhagwani, Hu Yang, Tatiana V. Kudryashova, Mauricio Rojas

Chemical and Biochemical Engineering Faculty Research & Creative Works

Pulmonary arterial hypertension (PAH) is a devastating and progressive disease with limited treatment options. Endothelial dysfunction plays a central role in the development and progression of PAH, yet the underlying mechanisms are incompletely understood. The endosome-lysosome system is important to maintain cellular health, and the small GTPase RAB7 regulates many functions of this system. Here, we explored the role of RAB7 in endothelial cell (EC) function and lung vascular homeostasis. We found reduced expression of RAB7 in ECs from patients with PAH. Endothelial haploinsufficiency of RAB7 caused spontaneous pulmonary hypertension (PH) in mice. Silencing of RAB7 in ECs induced broad …

Pisa Printing Microneedles With Controllable Aqueous Dissolution Kinetics, Aaron Priester, Jimmy Yeng, Yuwei Zhang, Krista Hilmas, Risheng Wang, Anthony J. Convertine

Chemistry Faculty Research & Creative Works

This study focused on the development of high-resolution polymeric structures using polymer-induced self-assembly (PISA) printing with commercially available digital light-processing (DLP) printers. Significantly, soluble solids could be 3D-printed using this methodology with controllable aqueous dissolution rates. This was achieved using a highly branched macrochain transfer agent (macro-CTA) containing multiple covalently attached CTA groups. In this work, the use of acrylamide as the self-assembling monomer in isopropyl alcohol was explored with the addition of N-(butoxymethyl)acrylamide to modulate the aqueous dissolution kinetics. PISA-printed microneedles were observed to have feature sizes as small as 27 μm, which was close to the resolution limit …

Wearable Mxene-Graphene Sensing Of Influenza And Sars-Cov-2 Virus In Air And Breath: From Lab To Clinic, Yanxiao Li, Zhekun Peng, Jiaoli Li, Congjie Wei, Shangbin Liu, Weixing Hao, Huanyu Cheng, Casey Burton, Yang Wang, Yue-Wern Huang, Chang Soo Kim, Fang Yao Stephen Hou, Donghyun (Bill) Kim, Chenglin Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The rapidly expanding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants demand a continuous monitoring method through portable and wearable devices. Utilizing the rich surface chemistry and high chemical-to-electrical signal conversion of 2D MXene-graphene heterostructure thin films, a field-effect-transistor (FET) sensor, which has a flexible substrate to be assembled onto the mask and combines with a Bluetooth system for wireless transmission is developed, to detect the influenza and SARS-CoV-2 viruses in air and breath. At first, the developed sensors are examined in the laboratory through direct contact with sensing targets in solution form. The results show a low …

Understanding Roles And Evaluating Reactivity Of Fly Ashes In Calcium Aluminate Binders, Sai Akshay Ponduru, Taihao Han, Jie Huang, Narayanan Neithalath, Gaurav Sant, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Calcium aluminate cement (CAC) is an alternative to Portland cement, valued for its superior early strength and thermal resistance. Partially replacing CAC with Fly ash (FA) can reduce carbon footprint and production costs of CAC, producing sustainable cementitious binders. This research investigates on various properties (i.e., hydration kinetics; phase assemblage evolution; compressive strength) of [CAC + FA] binders. Using 13 distinct FAs, up to 50% of CAC was substituted. The study measures hydration kinetics, compressive strength, and employs the number of constraints to estimate FA reactivity. Advanced quantitative analysis draws links between hydration kinetics and compressive strength and elucidate the …

Synergistic Effect Of Macro Synthetic Fiber And Shrinkage-Reducing Admixture On Engineering Properties Of Fiber-Reinforced Super-Workable Concrete, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to enhance fiber-reinforced super-workable concrete (FR-SWC) by optimizing the system of shrinkage-reducing admixture (SRA) and macro-synthetic fiber (MSF) for low shrinkage and uncompromised mechanical properties. A factorial design approach was employed to model the effect of fiber content, SRA dosage, and combined ratios of two types of MSF on performance of FR-SWC. MSF content had the greatest impact on mechanical properties, followed by SRA and MSF combination. Using MSF increased equivalent flexural strength ratio by 310% compared to the control mixture, regardless of MSF combination and SRA. SRA had the most significant effect on drying shrinkage, followed …

From Pumping To Deposition: A Comprehensive Review Of Test Methods For Characterizing Concrete Printability, Ali Fasihi, Nicolas A. (Ali) Libre

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

3D concrete printing (3DCP) technology has gained significant attention in the construction industry due to its potential to revolutionize the way buildings are designed and constructed. However, successful application of 3DCP requires robust standard test procedures to characterize the printability of concrete. Printability is a measure of workability for a printing material in the 3DCP process, which is characterized by pumpability, extrudability, and buildability. This paper presents a comprehensive review of the test methods that could be used for material characterization during various printing steps, including pumping, extrusion, and layer deposition. The underlying mechanisms relevant to each step, key governing …

Geodetic Strain Rates For The 2022 Update Of The New Zealand National Seismic Hazard Model, Jeremy Maurer, Kaj Johnson, Laura M. Wallace, Ian Hamling, Charles A. Williams, Chris Rollins, Matt Gerstenberger, Russ Van Dissen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Geodetic data in plate boundary zones reflect the accrual of tectonic strain and stress, which will ultimately be released in earthquakes, and so they can provide valuable insights into future seismic hazards. To incorporate geodetic measurements of contemporary deformation into the 2022 revision of the New Zealand National Seismic Hazard Model 2022 (NZ NSHM 2022), we derive a range of strain-rate models from published interseismic Global Navigation Satellite Systems velocities for New Zealand. We calculate the uncertainty in strain rate excluding strain from the Taupō rift–Havre trough and Hikurangi subduction zone, which are handled separately, and the corresponding moment rates. …

Retardation Effects In Atom-Wall Interactions, T. Das, C. A. Ullrich, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

The onset of retardation effects in atom-wall interactions is studied. It is shown that the transition range from the 1/z3 short-range (van der Waals) interaction to the 1/z4 long-range (Casimir) retarded interaction critically depends on the atomic properties and on the dielectric function of the material. For simple non-alkali-metal atoms (e.g., ground-state hydrogen and ground-state helium) interacting with typical dielectric materials such as intrinsic silicon, the transition to the retarded regime is shown to proceed at a distance of about 10 nm (200 Bohr radii). This is much shorter than typical characteristic absorption wavelengths of solids. Larger transition regimes are …

In Vitro Assessment Of Protamine Toxicity With Neural Cells, Its Therapeutic Potential To Counter Chondroitin Sulfate Mediated Neuron Inhibition, And Its Effects On Reactive Astrocytes, Derek W. Nelson, Jessica L. Funnell, Conrad H. Cheung, Geraldine B. Quinones, Christina S. Mendoza, Marvin Bentley, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Multiple therapies have been studied to ameliorate the neuroinhibitory cues present after traumatic injury to the central nervous system. Two previous in vitro studies have demonstrated the efficacy of the Food and Drug Administration-approved cardiovascular therapeutic, protamine (PRM), to overcome neuroinhibitory cues presented by chondroitin sulfates; however, the effect of a wide range of PRM concentrations on neuronal and glial cells has not been evaluated. In this study, we investigate the therapeutic efficacy of PRM with primary cortical neurons, hippocampal neurons, mixed glial cultures, and astrocytes. The threshold for PRM toxicity is shown to be at or above 10 µg …

Advancing Occupational Health In Mining: Investigating Low-Cost Sensors Suitability For Improved Coal Dust Exposure Monitoring, Mirza Muhammad Zaid, Nana Amoah, Ashish Kakoria, Yang Wang, Guang Xu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Exposure to coal dust in underground coal mines poses significant health risks to workers, including the development of diseases such as coal workers' pneumoconiosis and silicosis. Current available methods for monitoring coal dust exposure are expensive and time-consuming, necessitating the exploration of alternative approaches. Low-cost light scattering particulate matter sensors offer a promising solution, and its development in recent years has demonstrated some success in air quality monitoring However, its application in sensing coal particles is limited partially due to that the operating condition in a mine is different than the atmosphere. Thus, the objective of this paper is to …

Mission-Driven Inverse Design Of Blended Wing Body Aircraft With Machine Learning, Rohan S. Sharma, Serhat Hosder

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The intent of this work was to investigate the feasibility of developing machine learning models for calculating values of airplane configuration design variables when provided time-series, mission-informed performance data. Shallow artificial neural networks were developed, trained, and tested using data pertaining to the blended wing body (BWB) class of aerospace vehicles. Configuration design parameters were varied using a Latin-hypercube sampling scheme. These data were used by a parametric-based BWB configuration generator to create unique BWBs. Performance for each configuration was obtained via a performance estimation tool. Training and testing of neural networks were conducted using a K-fold cross-validation scheme. A …

Effects Of Laser Defocusing On Bead Geometry In Coaxial Titanium Wire-Based Laser Metal Deposition, Remy Mathenia, Aaron Flood, Braden Mclain, Todd Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention to the effects of deposition height and laser defocusing on the resulting bead geometry. As the deposition standoff distance changes, so does the workpiece illumination proportion, which describes the ratio of energy going directly into the feedstock wire and into the substrate. Single titanium beads are deposited at varying defocus levels and deposition rates and the bead aspect ratio is measured and …

Estimation Of Co2 Absorption By A Hybrid Aqueous Solution Of Amino Acid Salt With Amine, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Four developed machine learning algorithms are proposed to prognosticate the CO₂ solubility in amino acid salt solutions, blended with amine solutions as additives, in broad ranges of temperature and pressure. From literature 375 experimental data points for CO₂ solubility were collected. The results from the applied algorithms indicated that the CO₂ solubility is estimated acceptably close to the experimental values. In the best case, the developed network estimates CO₂ solubility in the stated solutions with an average relative deviation of 6.53 % and a correlation coefficient of 0.9892.

Improved Algorithms For Co-Scheduling Of Edge Analytics And Routes For Uav Fleet Missions, Aakash Khochare, Francesco Betti Sorbelli, Yogesh Simmhan, Sajal K. Das

Computer Science Faculty Research & Creative Works

Unmanned Aerial Vehicles (UAVs) or drones are increasingly used for urban applications like traffic monitoring and construction surveys. Autonomous navigation allows drones to visit waypoints and accomplish activities as part of their mission. a common activity is to hover and observe a location using on-board cameras. Advances in Deep Neural Networks (DNNs) allow such videos to be analyzed for automated decision making. UAVs also host edge computing capability for on-board inferencing by such DNNs. to this end, for a fleet of drones, we propose a novel Mission Scheduling Problem (MSP) that co-schedules the flight routes to visit and record video …

Upper Plate And Subduction Interface Deformation Models In The 2022 Revision Of The Aotearoa New Zealand National Seismic Hazard Model, Russ J. Van Dissen, Kaj M. Johnson, Hannu Seebeck, Laura M. Wallace, Chris Rollins, Jeremy Maurer, Matthew C. Gerstenberger, Charles A. Williams, Ian J. Hamling, Andrew Howell, Christopher J. Dicaprio

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

As part of the 2022 revision of the Aotearoa New Zealand National Seismic Hazard Model (NZ NSHM 2022), deformation models were constructed for the upper plate faults and subduction interfaces that impact ground-shaking hazard in New Zealand. These models provide the locations, geometries, and slip rates of the earthquake-producing faults in the NZ NSHM 2022. For upper plate faults, two deformation models were developed: a geologic model derived directly from the fault geometries and geologic slip rates in the NZ Community Fault Model version 1.0 (NZ CFM v.1.0); and a geodetic model that uses the same faults and fault geometries …

Multi-Dimensional Scaling Of Web-Scraping Results From The A.A Zalizniak Grammatical Dictionary And The Russian National Corpus. Creating A Corpus Fragment Of All Possible Word-Forms Of Modified Russian Sound Verbs Using Web-Scraping Methodology. Compilation Of A Summary Table For The Present Tense, Past Tense, Future Tense, Imperative, Imperfective And Perfective Gerund Forms, Irina Ivliyeva, Perry Koob

Research Data

This project attempts not only to improve the method of web extraction in relation to the source material (lexical-semantic group of Russian sound verbs, semantically modified at the word-forming level) but also systematize the search results using the format that is convenient and effective for a linguistic researcher. The main tasks at this stage of the research were to collect, compile (combine results), analyze and present a summary index of all possible verbal forms of sound verbs, recorded in electronic versions of dictionaries of the Russian language and in the database of the Russian National Corpus (RNC).

The output takes …

Dielectric Properties Of Polycrystalline And Single Crystal (100) Strontium Titanate From 4 To 295 K, Hung Trinh, Alan Devoe, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The dielectric properties of single crystal and polycrystalline SrTiO₃ (ST) were investigated from 295 to 4 K. Relative permittivity (εr) and loss tangent (tan(δ)) were measured systematically as a function of direct current (DC) voltage (0 V/cm to 800 V/cm), frequency (100 Hz to 1 MHz), and temperature (295 K to 4 K) for type (100) single crystal SrTiO₃ (SC-ST) and for polycrystalline SrTiO₃ (PC-ST). Calculated equivalent series resistance (ESR) data are also reported. Overall, the permittivity of ST showed a dependence on temperature, DC voltage, and frequency. Dependences on voltage and frequency were only observed at …

Modeling Of Single-Lap Joints With Auxetic Adhesive Utilizing Homogeneous And Heterogeneous Bondline Microstructures, Chatarina P. Puspaningtyas, Annisa Jusuf, Bambang K. Hadi, Arief Yudhanto

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Producing lightweight structures can be effectively achieved using adhesive bonding that incorporates a high-performance adhesive, eliminating the mechanical joints (rivet, bolts). Here, the proof-of-concept of tailoring the high-performance adhesive using microstructures exhibiting a negative Poisson's ratio (auxetic) is investigated using two single lap joint (SLJ) models developed in ABAQUS/Standard. The SLJ models consist of two rigid adherends that are bonded using either homogeneous or heterogeneous adhesive that produces auxetic response. In homogeneous adhesive, a negative value of Poisson's ratio is defined in the adhesive part of the models. In heterogeneous adhesive, the negative Poisson's ratio is obtained by explicitly building …

Miniaturized Fluorescence Ph Sensor With Assembly Free Ball Lens On A Tapered Multimode Optical Fiber, Bohong Zhang, Farhan Mumtaz, Muhammad Roman, Dinesh Reddy Alla, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In biochemistry, the absence of a compact, assembly-free pH sensor with high sensitivity and signal-to-noise ratio has been a persistent hurdle in achieving accurate pH measurements in real time, particularly in complex liquid environments. This manuscript introduces what we believe to be a novel solution in the form of a miniaturized pH sensor utilizing an assembly-free ball lens on a tapered multimode optical fiber (TMMF), offering the potential to revolutionize pH sensing in biochemical applications. A multimode optical fiber (MMF) was subjected to tapering processes, leading to the creation of an ultra-thin needle-like structure with a cross-sectional diameter of about …

Upconversion Photoluminescence Of Monolayer Wse2 With Biaxial Strain Tuning, Shrawan Roy, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Mechanical strain can be used to tune the optical properties of monolayer transition metal dichalcogenides (1L-TMDs). Here, up conversion photoluminescence (UPL) from 1L-WSe₂ flakes is tuned with biaxial strain induced by cruciform bending and indentation method. It is found that the peak position of UPL is redshifted by around 24 nm as the applied biaxial strain increases from 0% to 0.51%. At the same time, the UPL intensity increases exponentially for the up-conversion energy difference that lies within a broad range between −157 meV to −37 meV. The observed linear and sublinear power dependence of UPL emission in 1L-WSe …

Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating concrete (SCC) is used to repair structural elements with congested reinforcement or restricted access to placement and consolidation. In addition to adequate flowability, passing ability, filling capacity, and stability, adequate bonding to the substrate and reinforcing bars, low shrinkage and cracking resistance are required for successful repair. This study employs various shrinkage mitigating materials, including expansive agent (EA), coupled use of EA with shrinkage reducing admixture (SRA), and EA with pre-saturated lightweight sand (LWS) to fulfill these requirements. The effect of these materials on the performance of SCC made with a hybrid synthetic (PP) fiber and a hybrid steel-synthetic …

Quaternary Rare-Earth Oxyselenides Re4ga2se7o2 (Re = Pr, Nd) With Trigonal Bipyramidal Gase5 Units: Evaluation Of Optical, Thermoelectric, And Electrocatalytic Properties, Vidyanshu Mishra, Ibrahim Munkaila Abdullahi, Dundappa Mumbaraddi, Mohammed Jomaa, Louis Guérin, Manashi Nath, Arthur Mar

Chemistry Faculty Research & Creative Works

Phase-pure samples and single crystals of the rare-earth oxyselenides RE₄Ga₂Se₇O₂ (RE = Pr, Nd) were prepared by reactions at 950 °C. They adopt a new structure type (orthorhombic, space group Pnma, a = 11.721(2)-11.683(2) Å, b = 3.9882(7)-3.9667(7) Å, c = 29.644(5)-29.581(5) Å, Z = 4) consisting of RESe₆ trigonal prisms, GaSe₄ tetrahedra, and GaSe₅ trigonal bipyramids linked to form corrugated layers between which strips of edge-sharing RE₄O tetrahedra are inserted. The bonding character is mostly ionic within RE-O and RE-Se blocks but mostly covalent with Ga-Se blocks, …

Reactive Capture And Conversion Of Co2 Into Hydrogen Over Bifunctional Structured Ce1-Xcoxnio3/Ca Perovskite-Type Oxide Monoliths, Khaled Baamran, Shane Lawson, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon capture, utilization, and storage (CCUS) technologies are pivotal for transitioning to a net-zero economy by 2050. In particular, conversion of captured CO₂ to marketable chemicals and fuels appears to be a sustainable approach to not only curb greenhouse emissions but also transform wastes like CO₂ into useful products through storage of renewable energy in chemical bonds. Bifunctional materials (BFMs) composed of adsorbents and catalysts have shown promise in reactive capture and conversion of CO₂ at high temperatures. In this study, we extend the application of 3D printing technology to formulate a novel set of BFMs composed …

Dielectric Permittivity Of Pzt 95/5 Ferroelectric Ceramics And 0.27pin-Pmn-0.26pt Single Crystals Under Pulsed High Electric Fields, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Christopher S. Lynch

Mining Engineering Faculty Research & Creative Works

The dependence of the dielectric permittivity of ferroelectric materials on electric field magnitude impacts the performance of ferroelectric devices. In a ferroelectric generator, a shock wave travels through the ferroelectric element and depolarizes it, and surface charges are released from the element electrodes, resulting in the generation of a megawatt power level for several microseconds. The dielectric properties of the compressed and uncompressed zones of the ferroelectric element affect the generated voltage and energy. The results of previous studies indicate that the low-field dielectric permittivity of poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 (PZT 95/5) ferroelectrics in the uncompressed zone differs significantly from the high-field …

Experimental Realization Of The Peregrine Soliton In Repulsive Two-Component Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, Simeon I. Mistakidis, S. Mossman, G. Biondini, P. Schmelcher, P. Engels, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We Experimentally Realize the Peregrine Soliton in a Highly Particle-Imbalanced Two-Component Repulsive Bose-Einstein Condensate in the Immiscible Regime. The Effective Focusing Dynamics and Resulting Modulational Instability of the Minority Component Provide the Opportunity to Dynamically Create a Peregrine Soliton with the Aid of an Attractive Potential Well That Seeds the Initial Dynamics. The Peregrine Soliton Formation Is Highly Reproducible, And Our Experiments Allow Us to Separately Monitor the Minority and Majority Components, And to Compare with the Single Component Dynamics in the Absence or Presence of the Well with Varying Depths. We Showcase the Centrality of Each of the Ingredients …

Effects Of Organic Surface Contamination On The Mass Accommodation Coefficient Of Water: A Molecular Dynamics Study, Jordan Hartfield, Eric Bird, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The mass accommodation coefficient (MAC), a parameter that quantifies the possibility of a phase change to occur at a liquid-vapor interface, can strongly affect the evaporation and condensation rates at a liquid surface. Due to the various challenges in experimental determination of the MAC, molecular dynamics (MD) simulations have been widely used to study the MAC on liquid surfaces with no impurities or contaminations. However, experimental studies show that airborne hydrocarbons from various sources can adsorb on liquid surfaces and alter the liquid surface properties. In this work, therefore, we study the effects of organic surface contamination, which is immiscible …

Retraction Notice To “High Density Conductive Lifepo4 Cathode With Enhanced High-Rate And High Temperature Performance” [Mater. Chem. Phys. 232 (2019) 367–373, (S0254058419304110), (10.1016/J.Matchemphys.2019.05.014)], David Seung-Hyun Lee, Won Bin Im, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. The Editor-in-Chief found that the corresponding author of this article submitted the manuscript to the journal without the consent of the two individuals named as "co-authors", using invented email addresses to impersonate them. In addition, based on the raw materials presented to the journal by the second co-author and the Editor-in-Chief's own investigation, the Editor-in-Chief believes that some results in the paper are fabricated. Based on these two findings, the Editor-in-Chief has decided to retract the …

Unsupervised Blstm-Based Electricity Theft Detection With Training Data Contaminated, Qiushi Liang, Shengjie Zhao, Jiangfan Zhang, Hao Deng

Electrical and Computer Engineering Faculty Research & Creative Works

Electricity theft can cause economic damage and even increase the risk of outage. Recently, many methods have implemented electricity theft detection on smart meter data. However, how to conduct detection on the dataset without any label still remains challenging. In this article, we propose a novel unsupervised two-stage approach under the assumption that the training set is contaminated by attacks. Specifically, the method consists of two stages: (1) a Gaussian mixture model is employed to cluster consumption patterns with respect to different habits of electricity usage, and with the goal of improving the accuracy of the model in the posterior …

Quantum Scars And Regular Eigenstates In A Chaotic Spinor Condensate, Bertrand Evrard, Andrea Pizzi, Simeon I. Mistakidis, Ceren B. Dag

Physics Faculty Research & Creative Works

Quantum Many-Body Scars Consist Of A Few Low-Entropy Eigenstates In An Otherwise Chaotic Many-Body Spectrum, And Can Weakly Break Ergodicity Resulting In Robust Oscillatory Dynamics. The Notion Of Quantum Many-Body Scars Follows The Original Single-Particle Scars Introduced Within The Context Of Quantum Billiards, Where Scarring Manifests In The Form Of A Quantum Eigenstate Concentrating Around An Underlying Classical Unstable Periodic Orbit. A Direct Connection Between These Notions Remains An Outstanding Problem. Here, We Study A Many-Body Spinor Condensate That, Owing To Its Collective Interactions, Is Amenable To The Diagnostics Of Scars. We Characterize The System's Rich Dynamics, Spectrum, And Phase …

Rotational Spectrum And Ring Structures Of Silacyclohex-2-Ene And 1,1-Difluorosilacyclohex-2-Ene, Nicole T. Moon, Amanda J. Duerden, Thomas M.C. Mcfadden, Nathan A. Seifert, Gamil A. Guirgis, Garry S. Grubbs

Chemistry Faculty Research & Creative Works

Silacyclohex-2-ene and 1,1-difluorosilacyclohex-2-ene have been synthesized, and the chirped-pulse, Fourier-transform microwave spectra of each have been observed and analyzed from 4.9 to 23.1 GHz. Quantum chemical calculations have been performed at the B3LYP-D3BJ/Def2TZVP level of theory and predict μ_a to be the largest dipole moment component with a significantly larger value in this component for 1,1-difluorosilacyclohex-2-ene. In accordance with this prediction, the spectra were predominantly a-type with the observation of a few b- and c-type transitions. The signal-to-noise ratio was adequate in both spectra to observe ²⁹Si, ³⁰Si, and all singly substituted ¹³C isotopologues in natural …