Search

Your search keyword '"Prosser, Robert"' showing total 347 results
Start Over Author "Prosser, Robert"
347 results on '"Prosser, Robert"'

2. Flow characterisation and power consumption in an inline high shear rotor-stator mixer using CFD

Author

Michael, Vipin, Ahmed, Umair, Assad, Mahmoud, Prosser, Robert, and Kowalski, Adam

Subjects
Physics - Fluid Dynamics
Abstract

The aim of this paper is two-fold: (1) to provide a detailed investigation of the turbulent flow in an inline high-shear rotor stator mixer; (2) to provide a comparison of two different classes of turbulence models and solution methods currently available. The widely used multiple reference frame (MRF) method is contrasted against a more recently developed sliding mesh method. The sliding mesh algorithm accounts for rotation of the blades and is able to capture the transient effects arising from the rotor-stator interaction. The choice of turbulence model is shown to have a significant impact, with second moment closures able to capture best the hydrodynamics. With an appropriate choice of turbulence model and solution algorithm, we thus demonstrate the capacity of CFD to provide accurate and computationally cost effective characteristic power curve predictions.

Published
2023

3. Curvature-mediated Programming of Liquid Crystal Microflows

Author

Fedorowicz, Kamil, Prosser, Robert, and Sengupta, Anupam

Subjects
Condensed Matter - Soft Condensed Matter, Physics - Applied Physics, Physics - Fluid Dynamics
Abstract

Using experiments and numerical simulations, we demonstrate that the curvature of microscale conduits allow programming of liquid crystal (LC) flows. Focusing on a nematic LC flowing through U- and L-shaped channels of rectangular cross-section, our results reveal that curved flow paths can trigger gradients of flow-induced director field in the transverse direction. The emergent director field feeds back into the flow field, ultimately leading to LC flows controlled by the channel curvature. This curvature-mediated flow control, identified by polarizing optical microscopy and supported by the nematofluidic solutions, offers novel concepts in LC-based microfluidic valves and throttles, wherein the throughput distribution is determined by the Ericksen number and the variations in the local curvature. Finally, this work highlights the role of deformation history on flow-induced director alignments, when the viscous and elastic effects comparable in strength., Comment: 6 pages, 4 figures

Published
2023
Full Text
View/download PDF

19. Contributors

Author

Ahmad, Waseem Imtiaz, primary, Araç, Demet, additional, Atanes, Patricio, additional, Benhamú, Bellinda, additional, Bhattarai, Apurba, additional, Bouazza, Célia A., additional, Cerchio, Robert, additional, Charlton, Steven J., additional, Chattopadhyay, Amitabha, additional, Chen, Suzie, additional, Cordomí, Arnau, additional, Dubyak, George R., additional, Ehlert, Frederick J., additional, Farnan, Treyton S., additional, Filipek, Sławomir, additional, Franco, Rafael, additional, Gherbi, Karolina, additional, González-Maeso, Javier, additional, Groenewoud, Nickolaj J., additional, Guimarães, Thais Rafael, additional, Han, Xu, additional, Hébert, Terence E., additional, Holliday, Nicholas D., additional, Jakowiecki, Jakub, additional, Jastrzebska, Beata, additional, John, Karen Priyadarshini, additional, Karnik, Sadashiva S., additional, Keov, Peter, additional, Kibrom, Amanuel, additional, Knauss, Elizabeth A., additional, Kufareva, Irina, additional, Kumar, G. Aditya, additional, La Plante, Steven, additional, Larda, Sacha Thierry, additional, Leon, Katherine, additional, Li, Jing, additional, López-Rodríguez, María L., additional, Martin, Ryan D., additional, Miao, Yinglong, additional, Miszta, Przemysław, additional, Mohole, Madhura, additional, Navarro, Gemma, additional, Ngo, Tony, additional, Nieman, Marvin T., additional, Niewieczerzał, Szymon, additional, Ortega, Joseph T., additional, Pandey, Aditya, additional, Pardo, Leonardo, additional, Park, Paul S.-H., additional, Persaud, Shanta J., additional, Prosser, Robert Scott, additional, Qu, Xiangli, additional, Rajagopal, Sudarshan, additional, Sengmany, Kathy, additional, Sengupta, Durba, additional, Sierra, Salvador, additional, Singh, Khuraijam Dhanachandra, additional, Smith, Nicola J., additional, So, Sean S., additional, Thathiah, Amantha, additional, Toneatti, Rudy, additional, Vázquez-Villa, Henar, additional, Viswanathan, Gayathri, additional, Wainscott, David B., additional, Wang, Jinan, additional, Wang, Dejian, additional, Willard, Francis S., additional, Woulfe, Donna S., additional, Wu, Beili, additional, and Zheng, Kevin, additional

Published
2020
Full Text
View/download PDF

26. Improving estimates of growth for pearl perch (Glaucosoma scapulare) in Queensland, Australia

Author

Campbell, Matthew J., McLennan, Mark F., Nicolson, Jamie R., Garland, Anna, Prosser, Robert M., Midgley, Ricky F., Campbell, Matthew J., McLennan, Mark F., Nicolson, Jamie R., Garland, Anna, Prosser, Robert M., and Midgley, Ricky F.

Abstract

The pearl perch (Glaucosoma scapulare) is endemic to the east coast of Australia in depths to 150 m. The species has a long history of exploitation, and the stock is currently depleted. Previous research indicated the species is long lived and slow growing based on fishery-dependent sampling undertaken in the late 1990s and early 2000s on traditional fishing grounds at the southern end of the species’ range. Increasing fishing power has facilitated the expansion of the fishery to areas to the north and east of traditional grounds, which has resulted in the appearance of older fish (>10 yr) in fishery-dependent samples not previously observed. The current study estimated the growth parameters using 1153 length-at-age observations from fish collected in Queensland between January 2020 and December 2021. The lack of significant numbers of individuals at either end of the age frequency distribution necessitated the estimation of growth in a Bayesian framework with informative priors for length-at-age-zero and maximum length using a multi-model approach. The von Bertalanffy growth function (VBGF) was found to best fit the observed length-at-age data and the estimated VBGF parameters were L∞ = 562 mm FL, L0 = 2.02 mm FL and k = 0.295 yr−1. The high proportion of older fish in samples, combined with prior information on relevant parameters, improves growth parameter estimation by reducing bias and facilitating improved model fits to observed length-at-age data.

Published
2023

37. Insights into the Allosteric Response to Acidity by the Helicobacter pyloriNikR Transcription Factor

Author

Augustine, Jerry, Baksh, Karina A., Prosser, Robert Scott, and Zamble, Deborah B.

Abstract

Helicobacter pyloriNikR (HpNikR) is a nickel-responsive transcription factor that regulates genes involved in nickel homeostasis, which is essential for the survival of this pathogen within the acidic human stomach. HpNikR also responds to drops in pH and regulates genes controlling acid acclimation of the bacteria, independently of nickel. We previously showed that nickel binding biases the conformational ensemble of HpNikR to the more DNA-binding competent states via an allosteric network of residues encompassing the nickel binding sites and the interface between the metal- and DNA-binding domains. Here, we examine how acidity promotes this response using 19F-NMR, mutagenesis, and DNA-binding studies. 19F-NMR revealed that a drop in pH from 7.6 to 6.0 does little to shift the conformational ensemble of HpNikR to the DNA binding-compatible cis conformer. Nevertheless, DNA-binding affinities of apo-HpNikR at pH 6.0 and Ni(II)-HpNikR at pH 7.6 are comparable for the ureApromoter. Histidine residues of the nickel binding sites were shown to be important for pH-dependent DNA binding and thus likely impart positive charge to the protein, initiating long-range electrostatic interactions with DNA that induce DNA complexation. The results point to a different DNA-binding mechanism in response to acidity compared to the conformational selection mechanism in response to nickel and overall provide new insights into the influence of pH on HpNikR activity, which contributes to H. pyloriviability.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results