Changes In Size Distribution Research Articles

The formation of high CO2 loading solid phase from 1,4-butanediamine/ethylene glycol biphasic solvent: Phase-changing behavior and mechanism

Liquid-solid phase change absorption has been considered a promising strategy for CO2 capture. To achieve efficient and economic CO2 capture in industrial-scale applications, it is essential to understand the phase-change behaviors and mechanisms of the biphasic system. In this study, a blend of 1, 4-Butanediamine (BDA) and ethylene glycol (EG) was developed as a biphasic solvent that can form a high CO2 loading solid phase product (BESP) after absorption. The total solvent loading reached 0.9039 mol·mol−1, with 90.74% of the loading enriched in the solid phase, which only accounts for 51.01% of the total solvent mass. Based on the 13C NMR analysis and quantum chemical calculations, the reaction and phase change mechanism of CO2 capture was proposed. The BDA/EG system absorbs CO2 to generate carbamate species, protonated amines and alkyl-carbonates, which combine each other through hydrogen bonding or electrostatic attraction. The self-aggregation of zwitterions and the high polarity of the absorption products are considered to be the main reasons for the phase change. Alkyl-carbonate species are believed to co-precipitate through organic gelation via van der Waals force with the carbamate or protonated amine. Moreover, the viscosity, turbidity, solid-phase mass, and particle size distribution changes also demonstrate the growth and aggregation of particles during absorption. BESP, identified as a coupling product of carbamate and alkyl-carbonate ([2BDAH+COO-]·[EG‐OCO2-]), decomposes at a peak temperature of 127.4 °C. The calorimetric method determined regeneration heat to be approximately 3.17 GJ·ton-1 CO2, indicating its potential for alternative uses rather than direct heat regeneration. Such a biphasic solvent may provide unique solutions for industries to reduce CO2 emissions.

The impact of material chemistry and morphology on attrition behavior of excipients during high shear blending

Particle breakage by attrition is unavoidable in some unit operations and can lead to uncontrolled behavior of materials during processing. The aim of this study is to clarify the impact of material properties on attrition behavior. For the first time, an integral study with varying morphologies and chemistries is performed to identify the key drivers that impact attrition during high shear blending. Based upon the observed changes in particle size distribution, it was concluded that dicalcium phosphate (DCP) was the most prone to attrition, followed by mannitol, lactose and microcrystalline cellulose (MCC). Granular particles were more sensitive to attrition than sieved and spherical particles. Changes in bulk density, flow function coefficient and tablet tensile strength were observed as the result of attrition. The magnitude and direction of change in these parameters was not only dependent on the amount of attrition, but also on the morphology and the material deformation properties.

Cooperative interaction of a highly hydrophilic pluronic with bile salts of different hydrophobicity

In this study, we investigated the association of bile salts with pluronic F127 (F127) as a function of their hydrophobicity. Sodium cholate (NaC), sodium deoxycholate (NaDC) and sodium taurodeoxycholate (NaTDC) were used as bile salt. Our interpretations are based on the observations of isothermal titration calorimetry (ITC), high sensitivity differential scanning calorimetry (HSDSC), dynamic light scattering (DLS) and small angle neutron scattering (SANS) experiments. Bile salts affected the aggregation of F127 in accordance to their hydrophobicity, i.e. NaC<NaDC<NaTDC. Thermodynamically stable mixed aggregates were formed with NaC which remained confined at the interface even at high concentration (∼10 mM). On the contrary, hydrophobic NaTDC engaged more profoundly with F127 which manifested into dissociation of aggregates. With 4 mM NaTDC, the number density of aggregates increased more than ten-fold. We argue that dissociation would have occurred because of development of electrostatic repulsive forces in the presence of NaTDC molecules. This could be verified from bile salt driven changes in size distribution, aggregation number and thermodynamic parameters. For instance, upshift in critical micelle concentration and micellization temperature of F127 was recorded depending upon concentration of NaDC and NaTDC. Inspite of this, neutron scattering data ruled out the possibility of morphological transitions during these associations.

Characterization of local parameters of inclined upward air–water bubbly two-phase flows in a round pipe

The present work seeks to develop a detailed experimental database and characterize the local effects of inclination on horizontal and upward bubbly air–water two-phase flows. Experimental conditions are selected to investigate bubbly flows at a variety of orientations while reducing the influence of flow regime transition. Detailed time-averaged data is collected using state-of-the-art four-sensor conductivity probes for measurements across the flow area for five flow conditions at five inclination orientations in a 25.4 mm inner diameter pipe. Using the newly established database, effects of inclination on bubbly flows are analyzed, as are changes in liquid and gas flow rate at different orientations. The observations include (1) bubble migration and agglomeration at the top pipe wall as orientation changes from vertical to horizontal; (2) reducing the angle from vertical reduces the local gas velocity, and correspondingly reduces the global slip from greater than unity at 90° to less than unity for 60° and lower; (3) changes in the bubble size distribution are primarily at the interface between the bubble cluster and the liquid region of the pipe, not coalescence within the bubble cluster. Physical mechanisms for these observations are proposed, and the present trends at different orientations support previous experiments in horizontal two-phase flows.

Particle evolution mechanism of wide size distribution limestone under fluidized bed combustion conditions

The dynamic evolution of particles in limestone with a wide size distribution is significant for in-furnace desulfurization in circulating fluidized beds (CFB). In this study, air/SO2 mixtures were selected to simulate the flue gas combustion atmosphere, and the evolution on particle size of limestone with a wide size distribution was investigated using a self-built fluidized bed, with a focus on the evolution mechanism. The results show that the change in the cumulative particle size distribution (PSD) of limestone with a wide size distribution exhibited three stages as a function of reaction time. The cumulative PSD decreased continuously and reached 79.3% after 20 min during the first stage. The cumulative PSD was unchanged from 30 to 120 min in the second stage. The cumulative PSD increased from 81.9% to 88.3% in the range of 120–240 min during the third stage. The effects of attrition, heat stress, calcination, and sulfation on the changes in particle size were quantified and correlated with time. A novel method is proposed to predict the evolution mechanism of limestone with a wide size distribution. Calcination dominated in the time range of 0–60 min, and the predominant effect transformed from calcination to attrition at 240 min. However, the contribution of calcination was not negligible. The evolution of limestone with a wide size distribution can be promoted by the interactions of different effects.

The effect of temperature and predation on performance in monoculture and in competition in three Daphniidae differing in body size

AbstractZooplankton body size shows a strong association with temperature, competition, and predation. Global warming affects all three drivers of body size and is thus expected to lead to substantial changes in zooplankton community composition and body size distributions. To disentangle the isolated and joint effect of temperature, competition, and fish predation on species biomass and community composition in zooplankton, we monitored population biomasses of three Daphniidae species that differ in body size (Daphnia magna, Daphnia pulex, and Ceriodaphnia reticulata) for 20 days, manipulating competition (monoculture, pairwise trials, and three‐species communities), temperature (20°C, 24°C, and 28°C) and presence or absence of fish predation. In the absence of predation, D. magna dominated in all competition experiments, even at high temperatures. D. magna went extinct, however, in the predation treatments at 24°C and 28°C. D. pulex outcompeted C. reticulata and was negatively affected by predation and high temperature. C. reticulata did not reduce biomass at high temperatures and was negatively affected by all competition trials, but was positively affected by predation. Our results indicate that the two larger‐bodied species are more negatively affected by the combination of temperature and predation than the smallest species. While higher temperatures reduced the biomass of the larger‐bodied species, it did not fundamentally change their ability to dominate over the smallest species in competition. The combined effect of warming and predation changed community composition more fundamentally, resulting in the dominance of small‐bodied species. This can have important ecosystem‐wide impacts, such as the transition to turbid, algae‐dominated systems.

Critical distribution state of droplets dispersed in oil subjected to electric and centrifugal fields

Oil-water emulsions are extensively produced in industry, which may affect subsequent work or bring about environmental problems. Hence, it is necessary to demulsify and dewater it first. A coupling unit based on high-voltage electric and swirl centrifugal fields is adopted to satisfy emulsion demulsification and dewatering. The droplet size distribution is closely related to the separation performance of the coupling unit, while the droplet size distribution changes dynamically due to coalescence and breakage of the droplets. Droplets possess corresponding distribution under different coupling conditions, and the droplets size distribution may have a specific critical distribution state, in which the separation efficiency of the coupling unit reaches the optimal. Therefore, a numerical model is established to study the critical distribution state under double-field coupling in this study. The influence of coupling conditions on the droplet size distribution is studied to obtain the critical state of droplet size distribution, and the relationship between the critical state and the inlet droplet diameter is investigated. The results show that the critical state exists, and its distribution is as follows: there is a stable region with the maximum diameter gradient within 15 µm from the tail of the large cone section to the front of the small cone section (z = 700–760 mm) of the coupling unit; in the cross sections of the small cone section Z = 660–690 mm, the distribution of droplets volume fraction are almost identical, and the droplet diameter with the largest volume fraction is close to the median diameter. Moreover, the above critical state also exists for different inlet droplet diameters.

The Encapsulation of Natural Organic Dyes on TiO2 for Photochromism Control.

Titanium dioxide (TiO2) plays a pivotal role in photocatalytic reactions and holds great promise for the cosmetic and paint industries due to its white color and high refractive index. However, the original color of TiO2 changes gradually to blue or yellow with UV irradiation, which affects its color realization. We encapsulated TiO2 with several natural organic dye compounds, including purpurin, curcumin, and safflower, to control its photochromism and realize a range of different colors. The chemical reaction between TiO2 and dyes based on their functional group was investigated, and the light absorption was tested via FTIR and UV-Vis spectroscopy. The changes in morphology and size distribution additionally supported their successful encapsulation. The discoloration after UV irradiation was evaluated by measuring the color difference (ΔE) of control TiO2 and dye encapsulated TiO2. The unique structure utilized natural dyes to preserve photochromism based on the physical barrier and automatically controlled the electronic transition of core TiO2. In particular, the color difference values of purpurin and curcumin were 4.05 and 3.76, which is lower than the 5.36 of the control TiO2. Dye encapsulated TiO2 was manipulated into lipstick to verify its color realization and retention.

The characteristics of gas-liquid dispersive mixing and microbubble generation in turbulent adjustable jet flow field

In this study, the gas-liquid two-phase mixing process and the microbubbles formation process in a jet flow field has been investigated by using a self-designed on-line measurement system for measuring bubble generation characteristics and the Volume of Fluid (VOF) model in numerical simulation methods for analyzing flow field distribution characteristics. The effect of turbulence intensity on the dynamic size distribution of microbubble has been considered. The characteristics and duration of the three stages during the bubble breaking process, namely, surface oscillation stage, surface tension stage and fracture stage, were analyzed. The results show that the increase of turbulence intensity in jet flow will further promote the imbalance between the external deformation force and the surface tension resisting the deformation of the bubble, and promote the breaking probability of bubble. However, when the bubble breaks to a sufficiently small size, the surface tension against bubble deformation will increase sharply, the surface free energy needed to overcome for bubble breakage is very large, and the breakage probability of bubble will significantly decrease. Compared with the breaking process of bubbles, the increase in turbulence intensity will greatly promote the bubble coalescence process, which will ultimately become the main reason for affecting the bubble size distribution. Moreover, the influence of flow field distribution characteristics on bubble size distribution and average bubble size change is analyzed by using Population Balance Model.

Control the hydrophilic layer thickness of Janus membranes by manipulating membrane wetting in membrane distillation

Janus membranes with asymmetric wettability have attracted wide attentions for their robust anti-oil-wetting/fouling abilities in membrane distillation (MD). Compared to traditional surface modification approaches, in this study, we provided a new approach which manipulated surfactant-induced wetting to fabricate Janus membrane with a controllable thickness of the hydrophilic layer. The membranes with 10, 20, and 40 μm of wetted layers were obtained by stopping the wetting induced by 40 mg L−1 Triton X-100 (J = 25 L m−2 h−1) at about 15, 40, and 120 s, respectively. Then, the wetted layers were coated using polydopamine (PDA) to fabricate the Janus membranes. The resulting Janus membranes showed no significant change in porosities or pore size distributions compared with the virgin PVDF membrane. These Janus membranes exhibited low in-air water contact angles (< 50°), high underwater oil contact angles (> 145°), and low adhesion with oil droplets. Therefore, they all showed excellent oil-water separation performance with ∼100% rejection and stable flux. The Janus membranes showed no significant decline in flux, but a trade-off existed between the hydrophilic layer thicknesses and the vapor flux. Utilizing membranes with tunable hydrophilic layer thickness, we elucidated the underlying mechanism of such trade-off in mass transfer. Furthermore, the successful modification of membranes with different coatings and in-situ immobilization of silver nanoparticles indicated that this facile modification method is universal and can be further expanded for multifunctional membrane fabrication.

Improvement of HEK293 Cell Growth by Adapting Hydrodynamic Stress and Predicting Cell Aggregate Size Distribution.

HEK293 is a widely used cell line in the fields of research and industry. It is assumed that these cells are sensitive to hydrodynamic stress. The aim of this research was to use particle image velocimetry validated computational fluid dynamics (CFD) to determine the hydrodynamic stress in both shake flasks, with and without baffles, and in stirred Minifors 2 bioreactors to evaluate its effect on the growth and aggregate size distribution of HEK293 suspension cells. The HEK FreeStyleTM 293-F cell line was cultivated in batch mode at different specific power inputs (from 63 W m-3 to 451 W m-3), whereby ≈60 W m-3 corresponds to the upper limit, which is what has been typically described in published experiments. In addition to the specific growth rate and maximum viable cell density VCDmax, the cell size distribution over time and cluster size distribution were investigated. The VCDmax of (5.77±0.02)·106cellsmL-1 was reached at a specific power input of 233 W m-3 and was 23.8% higher than the value obtained at 63 W m-3 and 7.2% higher than the value obtained at 451 W m-3. No significant change in the cell size distribution could be measured in the investigated range. It was shown that the cell cluster size distribution follows a strict geometric distribution whose free parameter p is linearly dependent on the mean Kolmogorov length scale. Based on the performed experiments, it has been shown that by using CFD-characterised bioreactors, the VCDmax can be increased and the cell aggregate rate can be precisely controlled.

Effect of heating–water cooling cycle treatment on the pore structure and shear fracture characteristics of granite

In hot dry rock (HDR) geothermal energy extraction systems, jointed rock masses are often subjected to heating–water cooling (H-WC) cycles. In this process, HDR is at risk of failure and instability due to the change in pore structure and fracture characteristics. To identify the shear fracture characteristics of rocks after H-WC cycle treatment. First, shear fracture mechanical tests were carried out on granite specimens treated with H-WC cycles by using the short core compression (SCC) test method. The experimental results show that cyclic H-WC treatment leads to a decrease in fracture toughness values. It is especially noteworthy that the weakening effect of fracture toughness decreases with increasing cycles. Second, the NMR analysis results show that the porosity of granite samples increases with the number of H-WC cycles. At 400℃ and 600℃, the pore size distribution changes under H-WC. The slope of the fitting curve between fracture toughness and porosity indicates that the higher the temperature is, the lower the sensitivity of fracture toughness to porosity. Then, acoustic emission characteristics in the mechanical experimental process were analysed by using the b-value analysis method. The results indicated that the b-value of acoustic emission decreased with increasing cycles at 200 °C, so the crack size and energy release increased; however, at T = 400 °C and 600 °C, the b-value increased with an increasing number of cycles, so the crack size and energy release decreased. Finally, the fracture plane morphology of the failure specimens was obtained by a 3D optical scanner. The calculation results of the fractal dimension DF indicate that the cyclic H-WC treatment enhanced the fracture plane roughness, and the average increase in fractal dimension DF increases with increasing temperature, also indicating that the increasing effect of fracture plane roughness with increasing temperature becomes increasingly significant. At the same time, the fracture toughness under cyclic H-WC action was negatively correlated with the fracture plane roughness of granite.

Impact of Lockdown on Column and Surface Aerosol Content over Ahmedabad and a Comparison with the Indo-Gangetic Plain

Changes in vertical column concentration, size distribution, and surface concentration of aerosol associated with the lockdown imposed by the COVID-19 pandemic in 2020 over the Ahmedabad region in Gujarat State, India, were analyzed. The results are compared with changes over selected Indo-Gangetic Plain (IGP) regions. On 25 March 2020, the prime minister of India declared a complete lockdown throughout the country and later lifted restrictions in a phased manner. Aerosol optical depth (AOD) over the Ahmedabad region on 29 March dropped to as low as 0.11, and in the first two weeks of lockdown, the weekly average AOD was only 0.18. On almost all days of the lockdown period, AOD over the Ahmedabad region was lower than the decadal mean. It was found that the Ahmedabad region responded differently to lockdown conditions compared to the IGP regions. During the first lockdown phase, AOD decreased by about 29% compared to the pre-lockdown period over the Ahmedabad region. However, the average reduction over the IGP was much more, about 50%. The average Angstrom exponent (AE) of 0.96 during the pre-lockdown period over the Ahmedabad region increased phase-wise to 1.36 during the L3 lockdown phase, indicating dominance of fine-mode particles during the lockdown period. It suggests a reduction in anthropogenically produced coarse-mode particles, typically dust produced by vehicular movement, construction, and industrial activities. However, on the other hand, over the IGP region, the high dominance of fine-mode particles during the pre-lockdown period had changed to a high dominance of coarse-mode particles, especially over the Delhi region. This indicates a reduction in anthropogenically produced fine-mode particles, which are mainly generated by fossil and biofuels/biomass combustion, over the IGP region by lockdown conditions. Within a few days of lockdown, PM2.5 was reduced by 64% and 76% over the Ahmedabad and Delhi regions, respectively. The lockdown imposed by the pandemic provided an excellent opportunity to ascertain background aerosol conditions in the atmosphere.

Reverse Salt Flux Effect on Dewatering Chlorella vulgaris in a Forward Osmosis System

Microalgae shows a high potential to produce biofuel and forward osmosis (FO) has been proposed as a promising dewatering process for algal biomass separation from water. However, the effect of reverse salt flux (RSF) on algal biomass during the dewatering process using FO has not been completely explored. This study was to investigate the effect of different types of salt and their concentrations on algal biomass in terms of conductivity, settling velocity, and lipid contents in FS during a simulated FO-driven dewatering of Chlorella vulgaris microalgae. Three draw solution (DS) salts (NaCl, KCl and NH4Cl) were evaluated in RSF-simulating batch tests. The salt diffusion from the DS to the algal feed solution (FS) caused a static growth of algal biomass while increasing lipid content up to 14.8% at 8 mM NH4Cl. With the addition of the different salts, pH was maintained to the optimal algal thriving range (7.2–10.6), but the presence of salt stressed the algal cells and inhibited photosynthesis and algal growth within the experimental conditions. The settling velocity of the algal cells improved with the increase of salt content from 8 to 80 mM of each DS. It seemed that cell division could be accelerated in the presence of NH4Cl, and microscopic images showed a change in the algal cell size distribution, which may negatively affect algal settleability. DS salt in an FO-algal harvesting system should be selected based on the final algal properties and constituents required.

CFD-DEM simulation of fluorination reaction in fluidized beds with local grid and time refinement method

The gas-solid reaction process with wide particle size distribution is extensively used in the chemical engineering field, especially the particle reacts with the gas gradually, such as fluorination reactions in fluidized beds. When the computational fluid dynamics-discrete element method (CFD-DEM) is used for the coupling simulation of multiphase and polydisperse particle reaction system, the grid size directly affects the accuracy of flow field information and simulation of chemical reaction. Furthermore, particle calculation time step will directly affect the efficiency of coupling calculation. In this work, a local grid and time step refinement method is proposed to simulate multiphase and polydisperse particle fluidization reaction system. In this method, the refined DEM grids are automatically generated in the computational domain around the fine particles, and the detailed fluid phase information is obtained with the interpolation algorithm. In the two-phase coupling process, particles are divided into different groups based on physical properties, each group has its own independent time step. The multistage conical-cylindrical spouted bed is proposed for the fluorination reaction process; the operating gas velocity range of the polydisperse particle system is extended by the new design while the particle size distribution changes with the gas-solid reaction process. It is demonstrated that the local grid and time step refinement method can improve the accuracy and efficiency of the traditional CFD-DEM method in the reaction process simulation, which describes a polydisperse particle system with wide particle size distribution. Aimed at improving the simulation accuracy and efficiency, this paper will be helpful for simulating the particle reaction process in the gas-solid fluidized bed and beneficial for the development of the CFD-DEM method.

Estimation of particle size distributions in the atmosphere—analysis of Fe and Ca particles as the representative examples

Atmospheric aerosols, including primary aerosols emitted directly into the atmosphere and secondary aerosols generated in the atmosphere from various chemically complex particles, cause a variety of environmental problems such as climate change, photochemical smog formation, and a decrease in incoming solar radiation. Therefore, it is important to understand the causes of aerosol particles and their impact on human society. In particular, particle size is an important indicator of lung penetration depth, aerosol transport, and optical properties. Hence, we mathematically estimated the airborne particle size distributions of each chemical component by collecting aerosol samples from the atmosphere using two types of cyclone samplers, large and small cyclone samplers. This study’s findings also suggest that calculated changes in particle size distribution can reflect changes in particle sources. The higher resolution of the continuous functions will enable the detection of the subtle changes in particle size distributions of each chemical component, which is helpful to understand the temporal changes in the chemical properties of the airborne aerosol particles.

Experimental investigation of water retention curves of municipal solid wastes with different paper contents, dry unit weights and degrees of biodegradation

This paper investigates the drying and wetting water retention curves (WRCs) of municipal solid wastes (MSWs) with different paper contents, dry unit weights and degrees of biodegradation (DOBs). Fresh synthetic samples were prepared based on the field composition of the MSWs at Mugga Lane Landfill, the Australian Capital Territory (ACT), Australia. The degraded samples were prepared in simulators with MSWs of different initial dry unit weights and decomposition periods with leachate recirculation. The water retention curves (WRCs) of the MSWs were determined using pressure plate tests, in both drying and wetting phases. The outflow from MSWs was analysed using Gardner’s method to obtain the unsaturated hydraulic conductivity. The results indicate that the WRCs of the MSWs are greatly affected by the DOB, paper content and dry unit weight. When DOB < 30 %, as DOB increases, the air-entry pressure of MSWs with paper increases, and the residual moisture content decreases regardless of paper content. With DOB > 30 %, the air entry pressure and residual water content depend on the balance between organic matter and highly decomposed organic constituents. The paper content affects the WRCs of MSWs due to its water retention capacity and change in the particle size distribution with decomposition. The increase in the dry unit weight of MSWs significantly increases the air entry pressure and residual moisture content, similar to the borehole samples with combined effects of biodegradation and increase in stress level from literature. Hysteresis effects have been observed during the drying and wetting of MSWs. The hysteresis of WRCs increases with the paper content and DOB.

Investigation of Lyophilized Microspheres Loaded with Leuprolide Acetate

Abstract: Leuprolide acetate (LA) - a nonapeptide, used for the treatment of some hormone-depending diseases, is unstable and very susceptible to degradation in the aqueous media. Poly (lactic-co-glycolic) acid (PLGA) is a copolymer of lactide and glycolide, that has generated tremendous interest in pharmaceutics because of their excellent biocompatibility, biodegradability, and mechanical strength. PLGA is used for the preparation of biocompatible biodegradable extended-release microspheres. However, the PLGA undergoes hydrolytic degradation in an aqueous environment through cleavage of its backbone ester linkages. As a consequence, PLGA-based microspheres loaded with LA are usually lyophilized to ensure the stability of LA and PGLA and reduce agglomeration, sedimentation, and size change of microspheres during storage. The aim of this present study is to evaluate the influence of lyoprotectants namely mannitol, trehalose, lactose, and saccharose on the stability of LA and characteristics of PLGA-based microspheres loaded with LA upon lyophilization. DSC and FTIR were used to evaluate the biocompatibility of LA and lyoprotectants. The results showed that there was no incompatibility between the LA and lyoprotectants. Mannitol solution 1.25% was used in freeze-drying PLGA-based microspheres loaded with LA. The obtained lyophilized microspheres had a good appearance and low moisture. Lyophilized microspheres after reconstitution had no significant change in drug content, size, and size distribution in comparison to that before freeze-drying.&#x0D; Keywords: Leuprolide acetate, PGLA, lyophilized, stability, biodegradable microspheres.&#x0D; &#x0D;

A dual-geometry pore-size-resolved model to predict deep-bed loading in a wall-flow filter

A gasoline particulate filter (GPF) is an effective wall-flow technology for gasoline engine particulate matter (PM) emission control via deep-bed filtration through porous ceramic walls within a honeycomb channel structure. An analytical filter model is desired to understand its efficiency and pressure drop under engine operating conditions and, thereby, reduce the development costs for meeting emission regulations and engine performance targets. Most existing models either oversimplify the filter geometry or do not offer good predictions in the soot loading regime. The present work treats the deep bed regime as two co-existing filters with different geometries based on their natural morphologies, one that describes the porous wall and the other for the fiber structure created by soot deposition. Both models are dynamic to account for changes in pore size distribution and soot dendrite growth during loading. Model validation by 12 sets of experimental filter loading data shows that it provides reasonable predictions of both filter efficiency and pressure drop during deep-bed loading for different GPF wall-flow filters under various operating conditions. Scanning electron microscopy (SEM) confirms model predictions for the unit collector size of the dendritic filter formed by soot deposition. Numerical simulation using GeoDict was also carried out to validate the model predictions on particle deposition location. The model is used to investigate the evolution of pore-size-resolved aerosol flow, filtration efficiency, mass loading, and particle packing density during loading. The impact of porosity, mean pore size, and pore size distribution on filter loading performance is studied. The results suggest that increasing porosity, narrowing pore size distribution, and increasing mean pore size can improve filter performance, offering pathways for future filter optimization.

Effect of Lipase and Phospholipase A1 on Foaming and Batter Properties of Yolk Contaminated Egg White.

Egg white (EW) is frequently used in bakery products because of its excellent foaming capabilities. However, egg yolk (EY) contamination often degrades the foaming characteristics of EW. The purpose of this study was to investigate the effect of different concentrations of phospholipase A1 (PLPA1) and lipase (LP) on EW. The changes in particle size distribution and potential before and after enzymatic digestion of EW with contaminated 0.5 wt% and 1.0%wt EY were tested. The foaming rate and foam stability were measured after the dispersions were digested with different concentrations of PLPA1 and LP. Additionally, the dispersion samples were used to prepare batter and angel cake, and the modulus, density, and microstructure of the batter were analyzed. Results showed that the potential absolute value increased when the EY was hydrolyzed by PLPA1. The distribution of yolk particle size showed a new aggregation and the average particle size decreased after LP hydrolysis. The dispersion samples hydrolyzed by PLPA1 and LP recovered all the properties of the samples at enzymatic concentrations of 500 U/g and 2500 U/g. This may be attributed to the changes in yolk particles resulting from the enzymatic digestion of EY and the production of amphiphilic lysophospholipids, fatty acids, and glycerol.