Measurement and Modelling of Soft Solid Layers in Cleaning Applications

Fouling and effective cleaning are important operating issues in the food and pharmaceutical industries, which need to be managed well to ensure process hygiene and productivity. In order to understand fouling and cleaning mechanisms, methods are required to quantify soft solid soil or deposit characteristics by measuring these in situ. This dissertation describes the development of millimanipulation and two new fluid dynamic gauging (FDG) devices, namely sideways FDG (SiDG) and integrated FDG (iFDG), and demonstrates their application for in situ measurement. Computational fluid dynamic (CFD) simulations of the flow patterns using the volume of fluid method were performed which enables previously inaccessible information to be extracted from the experimental data. The millimanipulation device reported by Magens et al., J Food Eng, 197 (2017) 48-59 measures the force experienced by a blade as it is pushed through a soil layer. The deformation of layers of viscoplastic petroleum jelly, soft white paraffin and toothpaste were studied and simulated using the regularized Bingham and the bi-viscosity models. The simulations gave good agreement with experimental results: combining visualisation and an interrupted testing mode allowed the material’s yield stress to be estimated. The SiDG device allows one to study the initial and long-term swelling of soft solid layers. The concept was implemented, commissioned and demonstrated by monitoring the swelling of gelatin, poly(vinyl acetate) (PVAc) and complex model soil layers at different pH and temperatures. All these materials underwent rapid initial hydration, followed by different longer term behaviour: gelatin and PVAc layers at pH < 11 exhibited Fickian diffusion control while at pH ≥ 11, PVAc exhibited relaxation control associated with hydrolysis. In the iFDG system the distances between the nozzle head and the soil layer, and the metallic substrate, are measured simultaneously by incorporating an inductive sensor in the gauging nozzle. The iFDG device was taken from concept to demonstration with a range of gauging liquids: water, UHT milk (opaque), a more viscous Newtonian fluid (washing-up liquid) and non-Newtonian aqueous solutions of 1 wt% and 3 wt% carboxymethyl cellulose (CMC). The CFD simulations gave good agreement with the experimental data. An ice growth experiment was performed using the iFDG device to demonstrate its application to monitoring growth of fouling layers. The CFD simulations were extended to consider the coupled flows which can arise in FDG measurements, where the stressed imposed by the gauging liquid flow can deform the soft solid soil layer. Two-fluid simulations were performed to estimate the change of topography of a petroleum jelly layer subject to FDG testing at different clearances. Acceptable agreement between the simulation results and measurements was obtained, and the observed differences were attributed to tubing-induced artefacts. A short feasibility study considered extending the approach to the three-fluid problem when a coherent liquid jet impinges horizontally on a horizontal plane coated with a soft solid soil layer. The results showed promising agreement with experiments on water jet cleaning of petroleum jelly layers.Taiwan Cambridge Scholarship (Cambridge Trust and Ministry of Education, Taiwan

Osseous wound repair under inhibition of the axis of advanced glycation end-products and the advanced glycation end-products receptor

Background/PurposeBlockade of advanced glycation end-products (AGE) is able to reduce diabetic complications and control periodontitis. This study aimed to determine whether the application of aminoguanidine (AG), an AGE inhibitor, or N-phenacylthiazolium bromide (PTB), an AGE breaker, facilitates the healing of an osseous wound in non-diabetic animals.Methods2.6 mm diameter full-thickness osseous wounds were created bilaterally in 54 healthy Sprague–Dawley rats. Rats received daily normal saline, AG, or PTB injections respectively and were euthanized after 7 days, 14 days, or 28 days (n = 6). The wound healing pattern was assessed by micro-computed tomography, histology, histochemistry for the fiber arrangement, and the gene expression levels of AGE receptor, tumor necrosis factor-α, type I collagen, and fibronectin.ResultsUnder the AG and PTB administration, osteogenesis was apparently promoted in the early stages of healing, but the union of the osseous wound and the fibril re-arrangement was apparently retarded. No significant difference was found in any of the micro-computed tomography parameters as compared to the control in the first 14 days, whereas the relative bone volume was significantly higher in the control at Day 28. AGE receptor and tumor necrosis factor-α were depressed in the PTB group, but only temporarily at Day 14 in the AG group. Therefore, at Day 14, type I collagen was significantly upregulated in the PTB group, and fibronectin was significantly increased in the AG group.ConclusionAnti-AGE agents reduced inflammation but did not apparently facilitate osteogenesis during the osseous wound repair

Search for the decay of a Higgs boson in the ll gamma channel in proton-proton collisions at root s=13 TeV

A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search for a Higgs boson decaying into a pair of electrons or muons and a photon is described. Higgs boson decays to a Z boson and a photon (H Z , = e or ), or to two photons, one of which has an internal conversion into a muon pair (H (*) ) were considered. The analysis is performed using a data set recorded by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No significant excess above the background prediction has been found. Limits are set on the cross section for a standard model Higgs boson decaying to opposite-sign electron or muon pairs and a photon. The observed limits on cross section times the corresponding branching fractions vary between 1.4 and 4.0 (6.1 and 11.4) times the standard model cross section for H (*) (H Z ) in the 120-130 GeV mass range of the system. The H (*) and H Z analyses are combined for m(H) =125GeV, obtaining an observed (expected) 95% confidence level upper limit of 3.9 (2.0) times the standard model cross section.Peer reviewe

Research data supporting 'Fluid-Dynamic Gauging for Studying the Initial Swelling of Soft Solid Layers'

This data set contains experimental data, supplementary material and a Methods description associated with the paper of the same title published in AIChEJ. The data set shows experimental results associated with the calibration and testing of the new SiDG device. The Supplementary Material includes additional experimental material, codes in python and OpenFOAM to allow readers to create similar results, and working diagrams of the experimental apparatus so that the reader can make an SiDG device

Data in Figures published in Wang et al. J Biomech Eng 2021

Excel spreadsheet providing the data presented in the plots in the paper. See readme sheet for detailed information on the type and origin of the dat

Stability of the Interface Between Two Immiscible Liquids in a Model Eye Subject to Saccadic Motion.

The interface between silicone oil and saline layers in a three-dimensional model of the eye chamber was studied under different eye-like saccadic motions in order to determine the stability of the interface and propensity for emulsification in the bulk. The effect of level of fill, saccade amplitude, angular velocity, latency time, and orientation were investigated experimentally in spherical flasks with internal diameters 10, 28, and 40 mm, as well as a 28 mm diameter flask with an indent replicating the lens or the presence of a buckle. The deformation of the interface was quantified in terms of the change in its length in two-dimensional images. The deformation increased with Weber number, We, and was roughly proportional to We for We > 1. The presence of the lens gave rise to higher deformation near this feature. In all cases emulsification was not observed in either bulk fluid. The velocity profile in the spherical configuration was mapped using particle imaging velocimetry and is compared with an analytical solution and a short computational fluid dynamics simulation study. These confirm that the saccadic motion induces flow near the wall in the saline layer and significantly further into the chamber in the silicone oil. Surfactants soluble in the aqueous and oil phases reduced the interfacial tension, increasing deformation but did not lead to emulsification in the bulk.W.D. Armstrong Fund, University of Cambridge, PhD scholarship, R. Wang Cambridge Taiwan Trust, PhD scholarship, J.-H. Tsa

Membrane-Assisted Crystallization: A Molecular View of NaCl Nucleation and Growth

Membrane-assisted crystallization, aiming to induce supersaturation in a solution, has been successfully tested in the crystallization of ionic salts, low molecular organic acids, and proteins. Membrane crystallization is an emerging membrane process with the capability to simultaneously extract fresh water and valuable components from various streams. Successful application of crystallization for produced water treatment, seawater desalination, and salt recovery has been demonstrated. Recently, membrane crystallization has been developed to recover valuable minerals from highly concentrated solutions, since the recovery of high-quality minerals is expected to impact agriculture, pharmaceuticals, and household activities. In this work, molecular dynamics simulations were used to study the crystal nucleation and growth of sodium chloride in bulk and with hydrophobic polymer surfaces of polyvinylidene fluoride (PVDF) and polypropylene (PP) at a supersaturated concentration of salt. In parallel, membrane crystallization experiments were performed utilizing the same polymeric membranes in order to compare the experimental results with the computational ones. Moreover, the comparison in terms of nucleation time between the crystallization of sodium chloride (NaCl) using the traditional evaporation process and the membrane-assisted crystallization process was performed. Here, with an integrated experimental&#8315;computational approach, we demonstrate that the PVDF and PP membranes assist the crystal growth for NaCl, speeding up crystal nucleation in comparison to the bulk solution and leading to smaller and regularly structured face-centered cubic lattice NaCl crystals. This results in a mutual validation between theoretical data and experimental findings and provides the stimuli to investigate other mono and bivalent crystals with a new class of materials in advanced membrane separations