On bubble clustering and energy spectra in pseudo-turbulence

3D-Particle Tracking (3D-PTV) and Phase Sensitive Constant Temperature Anemometry in pseudo-turbulence--i.e., flow solely driven by rising bubbles-- were performed to investigate bubble clustering and to obtain the mean bubble rise velocity, distributions of bubble velocities, and energy spectra at dilute gas concentrations ($\alpha \leq2.2$%). To characterize the clustering the pair correlation function $G(r,\theta)$ was calculated. The deformable bubbles with equivalent bubble diameter $d_b=4-5$ mm were found to cluster within a radial distance of a few bubble radii with a preferred vertical orientation. This vertical alignment was present at both small and large scales. For small distances also some horizontal clustering was found. The large number of data-points and the non intrusiveness of PTV allowed to obtain well-converged Probability Density Functions (PDFs) of the bubble velocity. The PDFs had a non-Gaussian form for all velocity components and intermittency effects could be observed. The energy spectrum of the liquid velocity fluctuations decayed with a power law of -3.2, different from the $\approx -5/3$ found for homogeneous isotropic turbulence, but close to the prediction -3 by \cite{lance} for pseudo-turbulence

Chemogenetic Induced Tinnitus Model

This project will use chemogenetic drug activation in the inferior colliculus (IC) to formulate a new tinnitus model in animals. Gq-signaling DREADD [AAV8-CaMIIKa-HDM2(Gq)-mCherry] will be used to selectively activate glutamatergic neurons in the mouse, then the brain will be dissected to obtain the IC. The IC will be immunohistochemically stained to visualize the AAV mCherry, the glutamatergic neuron distribution, and the GABAergic neuron distribution within the IC. Thus, the findings of this study will better our understandings of the pathological mechanisms of tinnitus

ANALYZING RECYCLING OPTIONS FOR WIND TURBINE BLADE WASTE

The purpose of this study was to conduct a systematic literature review to identify recycling options for wind turbine blade waste. Wind energy is a rapidly growing energy source due to its renewability and accessibility. However, the turbines that produce this energy have blades that must be replaced throughout the turbine’s lifetime. The standard disposal method of decommissioned blades is the landfill. However, problems are arising within states as landfills are being overrun by the wind turbine blades once they reach their end-of-life. Conducting this study aims to provide a list of recycling options and provide an evaluation of each with suggestions on how to utilize them going forward. This study also aims to provide awareness on the issue of wind turbine blade waste. The results of this study concluded that cement co-processing was the best method for recycling wind turbine blade waste going forward because of its low environmental impact, cost, readiness, and quality. If this recycling method were to be implemented throughout the United States, a large amount of waste could be redirected from landfills

Lipid-protein and protein-protein interactions in the mechanisms of photosynthetic reaction centre and the Na+,K+-ATPase

Lipid-protein and protein-protein interactions are likely to play important roles in the function and regulation of charge-transporting membrane proteins. This thesis focuses on two different membrane proteins, the photosynthetic reaction centre (RC) from purple bacteria and the Na+,K+-ATPase. The influence of the lipid surroundings and cholesterol derivatives on the kinetics of electron transfer of the RC were investigated by reconstituting the protein in phosphatidylcholine vesicles containing cholesterol and derivatives known to modulate the membrane dipole potential. The experiments performed on the Na+,K+-ATPase were designed to contribute to a better understanding of the role that oligomeric protein-protein interactions have in the enzyme’s mechanism. Our results show that the cholesterol derivatives significantly modify the electron transfer kinetics within the RCs and their multiphasic behavior. These effects seem to be associated with the extent of the dipole potential change experienced by the RC within the phospholipid membrane. Indeed, the largest effects on the rates are observed when 6-ketocholestanol and cholesterol are present, consistent by with their previously demonstrated significant increase of the dipole potential. We interpret this data as indicating an increased free energy barrier for protons to enter the protein. The consequences of the increased dipole potential seem to be experienced across the entire protein, since the rates of the P+QA- charge recombination in the presence of AQ- acting as QA are also modified by the same effectors. Also interesting is the effect of the dipole potential on the two conformational states of the RCs (previously reported) as revealed by the biphasic decays of the electron transfer kinetics. In particular, we report for the first time a biphasicity of the P+QA- charge recombination in the WT RCs. This non exponential behaviour, absent in the phospholipid membrane or isolated RCs, is induced by the presence of the cholesterol derivatives, suggesting that the equilibration time between the two RC conformations is slowed down significantly by these molecules. According to this work, the dipole potential seems to be an important parameter that has to be taken into account for a fine understanding of the charge transfer function of the RCs. Reported literature values of the dissociation constant, Kd, of ATP with the E1 conformation of the Na+,K+-ATPase based on equilibrium titrations and kinetic methods disagree. Using isothermal titration calorimetry (ITC) and simulations of the expected equilibrium behaviour for different binding models, this thesis presents an explanation for this apparent discrepancy based on protein-protein interactions. Because of the importance of Mg2+ in ATP hydrolysis, kinetic studies of Mg2+ binding to the protein were also carried out. These studies showed that ATP alone is responsible for Mg2+ complexation, with no significant contribution from the enzyme environment

Expanding Peptide Stapling With S-Tetrazine

ABSTRACT EXPANDING PEPTIDE STAPLING WITH s-TETRAZINE Matthew H. Bunner Professor Amos B. Smith, III This dissertation presents efforts toward the extension of synthetic methods for the creation of peptide macrocycles via the addition of dichloro-s-tetrazine to peptide sequences containing lysine, serine, threonine, and tyrosine. Chapter one reviews the work and interest of the Smith group in the s-tetrazine chromophore and the history of stapled peptides in the chemical literature. Chapter two describes (A) the development of a synthetic protocol for the creation of peptide macrocycles from peptide sequences containing a single cysteine and a single lysine residue using dichloro-s-tetrazine including discussion on amino acid tolerance and seven successful examples, (B) efforts toward the development of a synthetic protocol for the creation of peptide macrocycles from peptide sequences containing a single cysteine residue and a single serine / threonine / tyrosine residue, and (C) efforts toward the investigation of the photochemical dissociation of the created cysteine / lysine peptide macrocycles. Chapter three describes our efforts to improve the synthesis of dichloro-s-tetrazine in a large-scale procedure

A Century of Faith and Victory (Original Transcript)

A history of Taylor University written by the Rev. Enoch A Bunner from the class of 1898 and presented in 1946 during the centennial celebration of Taylor University. This is the original typed transcript.https://pillars.taylor.edu/history_books/1043/thumbnail.jp

Waking up

My thesis project is composed of a large charcoal and ink drawing and two large, glass sculptures depicting variations on the human form. In order to construct sculptures of this scale, I have combined multiple castings as well as pieces made with hot blow molds. This document describes my process of choosing a thesis subject, building the works to go into it, designing a message I wanted my work to send, and how I plan to move forward.Honors CollegeThesis (B.?

Heat transfer mechanisms in bubbly Rayleigh-Benard convection

The heat transfer mechanism in Rayleigh-Benard convection in a liquid with a mean temperature close to its boiling point is studied through numerical simulations with point-like vapor bubbles, which are allowed to grow or shrink through evaporation and condensation and which act back on the flow both thermally and mechanically. It is shown that the effect of the bubbles is strongly dependent on the ratio of the sensible heat to the latent heat as embodied in the Jacob number Ja. For very small Ja the bubbles stabilize the flow by absorbing heat in the warmer regions and releasing it in the colder regions. With an increase in Ja, the added buoyancy due to the bubble growth destabilizes the flow with respect to single-phase convection and considerably increases the Nusselt number.Comment: 11 pages, 14 figure

The evolution of energy in flow driven by rising bubbles

We investigate by direct numerical simulations the flow that rising bubbles cause in an originally quiescent fluid. We employ the Eulerian-Lagrangian method with two-way coupling and periodic boundary conditions. In order to be able to treat up to 288000 bubbles, the following approximations and simplifications had to be introduced: (i) The bubbles were treated as point-particles, thus (ii) disregarding the near-field interactions among them, and (iii) effective force models for the lift and the drag forces were used. In particular, the lift coefficient was assumed to be 1/2, independent of the bubble Reynolds number and the local flow field. The results suggest that large scale motions are generated, owing to an inverse energy cascade from the small to the large scales. However, as the Taylor-Reynolds number is only in the range of 1, the corresponding scaling of the energy spectrum with an exponent of -5/3 cannot develop over a pronounced range. In the long term, the property of local energy transfer, characteristic of real turbulence, is lost and the input of energy equals the viscous dissipation at all scales. Due to the lack of strong vortices the bubbles spread rather uniformly in the flow. The mechanism for uniform spreading is as follows: Rising bubbles induce a velocity field behind them that acts on the following bubbles. Owing to the shear, those bubbles experience a lift force which make them spread to the left or right, thus preventing the formation of vertical bubble clusters and therefore of efficient forcing. Indeed, when the lift is artifically put to zero in the simulations, the flow is forced much more efficiently and a more pronounced energy accumulates at large scales is achieved.Comment: 9 pages, 7 figure

A Century of Faith and Victory (Later Transcript)

A history of Taylor University written by the Rev. Enoch A Bunner from the class of 1898 and presented in 1946 during the centennial celebration of Taylor University. This is a later transcript of the original transcript. Blank spaces correspond with typoes and unintelligible corrections in the original transcript. The original transcript was from 1946 but this copy appears to be from the 1990s, though there are no dates on this document. It may have been retyped on the occasion of Enoch\u27s death in 1992.https://pillars.taylor.edu/history_books/1044/thumbnail.jp