Biological and Chemical Physics Commons^™

Direct Computations Of Spatially Resolved Viscoelastic Moduli Of Biomolecular Condensates, Liwen Gu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Biomolecular condensates are viscoelastic materials formed by liquid-liquid phase separations (LLPS) of biopolymers. In this study, we develop a modified graph Laplacian-based collective model to characterize viscoelastic heterogeneity within condensates based on results of lattice-based Metropolis Monte Carlo (MMC) simulations. By integrating random graph models and simulations of A1-LCD, a type of intrinsically disordered protein, we examine how network topology influences storage modulus, loss modulus, crossover frequency, and relaxation time spectra. Our results reveal a strong correlation between topological features and mechanical response, with the condensate interior exhibiting higher stiffness and faster relaxation than the interface. The relaxation spectra provide …

Advancing Biofabrication Methodologies To Develop Biomimetic Tissue Scaffolds For Musculoskeletal Applications, Nashaita Yezdi Patrawalla

Theses and Dissertations

Musculoskeletal injuries impose a significant global burden, affecting millions and generating an economic toll exceeding $14 billion. Tissue engineering has gained traction as a promising strategy offering potential for functional restoration of damaged musculoskeletal tissues. This research aims to advance biofabrication techniques for generation of biomimetic tissue scaffolds, by optimizing scaffold design and modulating fabrication process parameters to generate scaffolds for musculoskeletal regeneration with application-specific tailored properties. In this realm, collagen-based biomaterials have been extensively investigated for tendon and ligamentous applications, and in combination with bioceramics incorporated into the collagen framework to produce composite scaffolds that better recapitulate the native …

Drag Reduction In Channel Flow Configurations For Laminar And Turbulent Flow Past Superhydrophobic Surfaces, Henry Louis Ems

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

In this work, we present friction drag reduction in minichannel laminar flow past superhydrophobic metallic surfaces. Femtosecond laser surface processing (FLSP), a one-step scalable method, was used to create permanent microscale and nanoscale structures on 316 stainless steel plates. The resulting superhydrophilic plates were covered by tall (215 μm) or short (27 μm) structures. The FLSP plates were then transitioned to superhydrophobic by evaporative deposition of a fluorinated silane, a low surface energy coating. Using purified water, the friction factor was obtained by measuring pressure drop along a minichannel with a rectangular cross section for flow rates corresponding …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Impacts And Applications Of Vegetable Glycerin On Nanocellulose, Elise Hong-Miller, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is created by breaking down cellulose, the most common organic molecule found in nature. Nanocellulose has attractive properties, such as a very high strength-to-weight ratio, for many different applications. A major challenge is that nanocellulose has a very high shrinkage % (~90%) when it is dried, as well as a strong probability to crack. Different additives can be added in varying amounts to either mitigate or intensify these aspects, as well as affect its drying conditions. This investigation is helping the National Aeronautics and Space Administration (NASA) and the U.S. Army to find a use for this highly renewable …

Flow Through Processing Of Nanocellulose For Space Exploration Applications, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is synthesized from cellulose, which is the most abundant organic molecule found in nature. Nanocellulose solids are biodegradable and have a strength-to-weight ratio eight times that of steel¹. The production of nanocellulose solids is challenging due to the large volume loss that occurs during the curing process as well as the time and cost associated with ultrasonic processing. The loss of volume during curing often results in cracking and deformation of the cured solid. The issues caused by the large volume loss can be mitigated using additives that do not compromise the strength, shape, or machineability of …

Molybdenum Disulfide (Mos₂) As A Nanocellulose Substrate, Mariana Torres, Dylan Seiffert, Elise Hong-Miller, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Cellulose is a substance abundant in nature, found in fruits and vegetables, plant cell walls (National Center for Biotechnology Information, 2023), and wood (Sjostrom, 1993). The abundance of cellulose is attributable to its linear chemical structure, as it is composed of long strands of glucose molecules linked together by hydrogen atoms, which enable the substance to withstand significant pressure without breaking (Rongpipi et al., 2019). This property—known as high tensile strength—is joined by its non-toxicity and sustainability, given cellulose may be degraded and renewed naturally (Kaur, 2021). These various properties indicate versatility, and its resultant current and desired uses—such as …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Investigation Of Optical And Structural Properties Of Gesn Heterostructures, Oluwatobi Gabriel Olorunsola

Graduate Theses and Dissertations

Silicon (Si)-based optoelectronics have gained traction due to its primed versatility at developing light-based technologies. Si, however, features indirect bandgap characteristics and suffers relegated optical properties compared to its III-V counterparts. III-Vs have also been hybridized to Si platforms but the resulting technologies are expensive and incompatible with standard complementary-metal-oxide-semiconductor processes. Germanium (Ge), on the other hand, have been engineered to behave like direct bandgap material through tensile strain interventions but are well short of attaining extensive wavelength coverage. To create a competitive material that evades these challenges, transitional amounts of Sn can be incorporated into Ge matrix to form …

Molecular Dynamics Simulations Of Self-Assemblies In Nature And Nanotechnology, Phu Khanh Tang

Dissertations, Theses, and Capstone Projects

Nature usually divides complex systems into smaller building blocks specializing in a few tasks since one entity cannot achieve everything. Therefore, self-assembly is a robust tool exploited by Nature to build hierarchical systems that accomplish unique functions. The cell membrane distinguishes itself as an example of Nature’s self-assembly, defining and protecting the cell. By mimicking Nature’s designs using synthetically designed self-assemblies, researchers with advanced nanotechnological comprehension can manipulate these synthetic self-assemblies to improve many aspects of modern medicine and materials science. Understanding the competing underlying molecular interactions in self-assembly is always of interest to the academic scientific community and industry. …

Methods To Remotely Eliminate Biofilm From Medical Implants Using 2.4 Ghz Microwaves, Brett Glenn

Mechanical Engineering Undergraduate Honors Theses

Infections associated with biofilm growth are usually challenging to eradicate due to their high tolerance toward antibiotics [11, 12]. Biofilms often form on the inert surfaces of medically implanted devices [13]. No matter the sophistication, microbial infections can develop on all medical devices and tissue engineering constructs [12]. Related infections lead to 2 million cases annually in the U.S., costing the healthcare system over $5 billion in additional healthcare expenses [12].

Novel solutions to biofilm’s microbial colonization span the spectrum of engineering and science disciplines. Yet a practical solution still does not exist. The research presented here will explore a …

Optical Enhancement In Periodic Plasmonic Gratings For Sers And Metal-Semiconductor-Metal Photodetectors (Msm-Pds) Applications, Ahmad Aziz Darweesh

Graduate Theses and Dissertations

This dissertation is aimed to numerically study the effect of plasmonic grating electrodes on the efficiency of metal-semiconductor-metal photodetectors (MSM PDs) and the sensitivity of Surface Enhanced Raman Spectroscopy (SERS). This research can benefit many areas of nanoscience and optics, including plasmonic applications, such as, super lenses, nano-scale optical circuits, optical filters, surface plasmon enhanced photo-detectors solar cells, imaging sensors, charge-coupled devices (CCD), and optical-fiber communication systems. Several parameters, wire widths and thickness, gap space, taper angle, and the incident wavelength and angle, were investigated. The goal of this research is to utilize the plasmonic phenomenon by using plasmonic gratings …

The Incorporation Of Graphene To Lithium Cobalt Oxide As A Cathode To Improve The Performance Of Lithium Ion Batteries, Kenan Wang

Graduate Theses and Dissertations

One of the objectives of this thesis work was to investigate the cathode performance of lithium cobalt oxide (LiCoO2) incorporated with graphene powder in lithium ion batteries (LIBs). Graphene powder was incorporated into cathode materials to enhance the performance of LIBs. The other objective was to impede the construction of a solid electrolyte interphase (SEI) sheet using graphene sheet coating on its cathode.

The results of this work show that adding graphene powder improved the performance of LiCoO¬2 as a cathode material. With the incorporation of different weight percentages of graphene powder, the LiBs showed distinct changes in their charging …

Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?, Michael A. Scarlett

CMC Senior Theses

Fossils belonging to the genus Homo, dating as far back as two million years ago, exhibit uniquely efficient features suggesting that early humans had evolved to become exceptional endurance runners. Although they did not have the cushion or stability-control features provided in our modern day running shoes, our early human ancestors experienced far less of the running-related injuries we experience today. The injury rate has been estimated as high as 90% annually for Americans training for a marathon and as high as 79% annually for all American endurance runners. There is an injury epidemic in conventionally shod populations that …

Thin Film Thermal Deposition At Various Pressures, James Kela Yee Keen Grace

Senior Theses

This research was to verify the hypothesis that resistivity of metal's thin film deposited in a low-pressure environment is the same as its solid material. Thermal Evaporation is a thin film deposition technique in which metal inside a vacuum is evaporated, then deposited onto a surface. Higher quality metal films are deposited when the vacuum pressure is lower. At higher pressures, more air molecules are trapped within the layers of metal, thus increasing scattering sites and increasing the resistance. However, reaching a lower pressure requires more time and effort. In this research, films were deposited at various pressures and resistivities …

Study Of Nano-Bio Interfaces In Nano-Bio Conjugates: Nanoparticles Of Zinc Oxide (Zno) And Biomolecules Of Glucose, Cytosine, And Thymine, Bithi Paul

Graduate Theses/Dissertations

Nano conjugates, composites of inorganic nanomaterials and bio molecules such as DNA, RNA and proteins, establish a sequence of wide varieties of nano-bio boundaries. The formation of these boundaries strongly depends on bio physicochemical reaction of biomolecules coated on the surface of nanomaterials. I am investigating various nano-bio conjugates consisting of zinc oxide (ZnO) nanoparticles with simple biomolecules including glucose and the nitrogenous bases of DNA such as cytosine and thymine. All nano-bio conjugates were fabricated using a standard bio-chemical synthesis process. Structural, physical, bio-chemical interface properties of nano-bio composites were probed using X-ray diffraction (XRD), Raman spectroscopy, and photoluminescence …

High Pressure Structural Studies On Nb5si3 Up To 26.2 Gpa, Brandon Stewart, Ravhi S. Kumar

Undergraduate Research Opportunities Program (UROP)

With the use of synchrotron techniques, we can better understand how crystalline structures behave under extreme conditions. This yields the opportunity to resolve complex crystal structures [1]. Here, we focus on the high pressure crystal structure of Nb5Si3. Refractory metal silicides are an important class of materials as they are used in high temperature applications such as turbines and aerospace modules. As an example, the performance of a jet engine is highly influenced by the maximum internal pressure and temperature possible. Obtaining higher levels of thrust is dependent upon the material's ability to remain structurally sound under extreme temperatures and …

Yttrium And Hydrogen Superstructure And Correlation Of Lattice Expansion And Proton Conductivity In The Bazr0.9y0.1o2.95 Proton Conductor, A. Braun, A. Ovalle, V. Pomjakushin, A. Cervellino, S. Erat, Wayne C. Stolte, T. Graule

Chemistry and Biochemistry Faculty Research

Bragg reflections in Y-resonant x-ray diffractograms of BaZr_0.9Y_0.1O_2.95 (BZY10) reveal that Y is organized in a superstructure. Comparison with neutron diffraction superstructure reflections in protonated/deuterated BZY10 suggests that both superstructures are linked, and that protons move in the landscape imposed by the Y. The thermal lattice expansion decreases abruptly for protonated BZY10 at T≥648±20 K, coinciding with the onset of lateral proton diffusion and suggesting a correlation of structural changes and proton conductivity. The chemical shift in the Y L₁-shell x-ray absorption spectra reveals a reduction from Y³⁺ toward Y²⁺ upon …

Spectroscopic And Microscopic Investigation Of The Corrosion Of 316/316l Stainless Steel By Lead-Bismuth Eutectic (Lbe) At Elevated Temperatures: Importance Of Surface Preparation, Allen L. Johnson, Denise Parsons, Julia Manzerova, Dale L. Perry, Daniel Koury, Brian D. Hosterman, John Farley

Transmutation Sciences Materials (TRP)

The corrosion of steel by lead–bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation: a cold-rolled …

Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

In industry there are many examples of absorption of a gas with or without chemical reaction in the liquid phase. In physical absorption, a particular gaseous component is removed from a gas mixture due to its larger solubility in the liquid phase solvent. The removal of butane and pentane from a refinery gas mixture by a heavy oil in the liquid phase is an example of physical absorption. In absorption with chemical reaction, the gaseous component to be removed transfers across the gas-liquid interface due to a difference in the bulk chemical potentials or concentrations in the two phases. The …

A Study Of Chromium-Doped High Lead Containing Silicate Glasses For Possible Laser Action, Mervet Maurice Saleh

Archived Theses and Dissertations

No abstract provided.

Epr Spectra Of Divalent Manganese In Halide Crystals, Veron Sarkis Sarkissian

Archived Theses and Dissertations

No abstract provided.