Particle Diameter Research Articles

Lithium-ion battery heterogeneous electrochemical-thermal-mechanical multiphysics coupling model and characterization of microscopic properties

In the design and optimization process of lithium-ion battery electrodes, microscopic performance characterization is extremely crucial. The current multiphysics field coupling models for lithium-ion batteries predominantly use homogeneous descriptions of electrode particles and pores, which restricts the characterization of microscale electrode properties. There are fewer heterogeneous multiphysics field coupling models capable of simultaneously integrating electrochemical, thermal, and mechanical fields. Addressing this issue, this study introduces a lithium-ion battery heterogeneous electrochemical-thermal-mechanical (HETM) multiphysical field coupled model that considers the diameter and spatial distribution of active particles. This model employs the Monte Carlo method to reconstruct two-dimensional electrodes and establishes the corresponding electrochemical-thermal-mechanical multiphysical field coupled theoretical and finite element simulation models. The HETM model is validated through discharge and charge curves at various C-rates and material, demonstrating higher accuracy and the ability to provide more precise data for the design and optimization of lithium-ion batteries. The model considers the bidirectional coupling between electrochemical-thermal and electrochemical-mechanical processes, as well as the unidirectional coupling between thermal and mechanical interactions, allowing for a more comprehensive analysis of both the microscopic and macroscopic characteristics of the battery.

Effect of colloidal particle size on physicochemical properties and aggregation behaviors of two alkaline soils

Abstract. Colloidal particles are the most active soil components, and they vary in elemental composition and environmental behaviors with the particle size due to the heterogeneous nature of natural soils. The purposes of the present study are to clarify how particle size affects the physicochemical properties and aggregation kinetics of soil colloids and to further reveal the underlying mechanisms. Soil colloidal fractions, from two alkaline soils – Anthrosol and Calcisol – were subdivided into three ranges: d<2 µm, d<1 µm and d<100 nm. The organic and inorganic carbon contents, clay mineralogy and surface electrochemical properties, including surface functional groups and zeta potentials, were characterized. Through a time-resolved light scattering technique, the aggregation kinetics of soil colloidal fractions were investigated, and their critical coagulation concentrations (CCCs) were determined. With decreasing colloidal particle diameter, the total carbon content, organic carbon, organic functional groups' content and illite content all increased. The zeta potential became less negative, and the charge variability decreased with decreasing particle diameter. The CCC values of Anthrosol and Calcisol colloids followed the descending order of d<100 nm, d<1 µm and d<2 µm. Compared with the course factions (d<1 and d<2 µm), soil nanoparticles were more abundant in organic carbon and more stable clay minerals (d<100 nm); thus they exhibited strongest colloidal suspension stability. The differences in organic matter contents and clay mineralogy are the fundamental reasons for the differences in colloidal suspension stability behind the size effects of Anthrosol and Calcisol colloids. The present study revealed the size effects of two alkaline soil colloids on carbon content, clay minerals, surface properties and suspension stability, emphasizing that soil nanoparticles are prone to be more stably dispersed instead of being aggregated. These findings can provide references for in-depth understanding of the environmental behaviors of the heterogeneous soil organic–mineral complexes.

An Electrochemical Dopamine Assay with Cobalt Oxide Palatinose Carbon Dots.

Elevated dopamine (DA) levels in urine denote neuroblastoma, a pediatric cancer. Saccharide-derived carbon dots (CDs) were applied to assay DA detection in simulated urine (SU) while delineating the effects of graphene defect density on electrocatalytic activity. CDs were hydrothermally synthesized to vary graphene defect densities using sucrose, raffinose, and palatinose, depositing them onto glassy carbon electrodes (GCEs). Co3O4 nanoparticles (NPs) were encapsulated by the CDs. Cyclic (CV) and linear sweep (LSV) voltammetry measurements were obtained, drop-casting the CDs onto GCEs and measuring DA in a phosphate-buffer solution (pH = 7). DA had an oxidation peak at +0.2 V with SucCDs, with the highest current correlating with the highest defect density. PalCD-Co3O4 exhibited the largest signal for DA detection in simulated urine (SU) using the oxidation peak at +0.5 V; the composite had a lower defect density compared to SucCD-Co3O4. The Co3O4-PalCDs had a DA detection range of 1 to 90 µM with an LOD of 0.88 μM in SU. SEM-EDX analysis of the electrode surface revealed semi-spherical structures with an average particle diameter of 80 ± 19 nm (n = 347) with PalCDs decorating the Co3O4 NPs. XRD characterization showed the incorporation of PalCD and Co3O4 within the composite. XPS showed electron density donation from the PalCD to Co3O4.

Antibacterial Efficacy Comparison of Electrolytic and Reductive Silver Nanoparticles Against Propionibacterium acnes.

Background: The aim of this study was to develop an electrolysis system to produce silver nanoparticles free from toxic gases, as the most common reduction and electrolysis techniques produce nitrogen dioxide (NO2) as a byproduct, which is harmful to human health. The new electrolysis system used two identical silver plate electrodes, replacing silver and carbon rods, and used water as the electrolyte instead of silver nitrate (AgNO3) solution since AgNO3 is the source of NO2. Methods: The electrolytic silver nanoparticles (ESNs) produced by the new system were characterized and compared with reductive silver nanoparticles (RSNs). Using UV-Visible spectrophotometry, absorption peaks were found at 425 nm (ESN) and 437 nm (RSN). Using dynamic light scattering, the particle diameters were measured at 40.3 nm and 39.9 nm for ESNs at concentrations of 10 ppm and 30 ppm, respectively, and 74.0 nm and 74.6 nm for RSNs at concentrations of 10 ppm and 30 ppm, respectively. Antibacterial activity against Propionibacterium acnes (P. acnes) was assessed using the Kirby-Bauer method. Results: It was found that the efficacy of ESNs and RSNs was relatively lower than that of 5% chloramphenicol because it was measured in different concentration units (ESNs and RSNs in ppm and chloramphenicol in %). Using the calibration curve, the efficacy of 5% chloramphenicol was comparable to that of 0.005% ESN. It was also found that P. acnes developed a strong resistance to chloramphenicol and showed no resistance to ESNs. Conclusions: This finding underlines the tremendous potential of ESNs as a future antibiotic raw material.

Interaction mechanism of dislocations with Bi/hBN nanoparticles in free-cutting steels: molecular dynamics simulations

Abstract To further understand the mechanical properties of free-cutting steels, we employed molecular dynamics (MD) simulations to investigate the interaction mechanisms between dislocation slip along close-packed planes and nano-inclusion particles (Bi/h-BN) within single-crystal iron (Fe). By colliding dislocations at varying slip velocities with nanometer-scale particles of different sizes and compositions, we concluded that particle diameter plays a decisive role not only in determining the dislocation cutting mode but also in influencing the dislocation’s shear stress response. These indicate that: Larger particles significantly enhance the strengthening effect on the matrix. Additionally, higher dislocation slip velocities result in stronger particle interaction feedback and greater particle damage, contributing to increased matrix deformation. h-BN particles, owing to their much higher hardness compared to Bi, exhibited superior resistance to deformation, requiring higher dislocation shear stress to pass these obstacles.

Comparative Analysis of Spreader Grafts and Spreader Flaps on Intranasal Drug Delivery Efficiency to Posterolateral Nasal Wall

Background: This study compared the impact of spreader grafts (SG) and spreader flaps (SF) on the transport of intranasal drug delivery to target the posterolateral nasal wall. Method: SG and SF were each performed in sequence on two cadaveric specimens after soft tissue elevation technique. Computed tomography scans were acquired following each procedure to generate anatomic models for computational fluid dynamics simulation of intranasal sprays under the following conditions: inhalation rate (15 and 30 L/min), spray velocity (1, 5, and 10 m/s), spray released location (center, lateral, medial, top, and bottom), head position (upright, tilted-forward, tilted-backward, and supine), and particle diameter (1-100 µm). Percentage of particles deposited on the posterolateral nasal wall were calculated. Results: For Specimen 1, highest posterolateral wall depositions were Pre-Op: left = 74%, right = 74%; SF: left = 53%, right = 22%; SG: left = 60%, right = 61%. For Specimen 2, highest posterolateral wall depositions were Pre-Op: left = 25%, right = 83%; SF: left = 29%, right = 76%; SG: left = 14%, right = 72%. In general, posterolateral wall deposition was higher at 30 L/min inhalation rate and at 1 m/s spray velocity. Conclusions: Drug delivery targeting the posterolateral nasal wall appears to be dependent on many factors. However, midvault nasal reconstruction does not increase drug delivery to the posterolateral nasal wall.

Humidity dependence of AE activity in sheared quartz gouges and its implication for the micromechanics of friction

Abstract The micromechanics of friction has been investigated from the viewpoint of the healing of real contacts. In this study, the underlying processes of friction are discussed from the viewpoint of the contact junction deformation and failure by measuring the acoustic emission (AE) activity associated with the frictional sliding. Sliding-rate step tests of synthetic quartz gouges sandwiched between metal forcing blocks are conducted using a low-speed (< 700 μm/s) rotary shear apparatus. Humidity is controlled to be dry (~ 5%RH), room (~ 40%RH), humid (100%RH), or wet (saturated without pore pressure control). The frictional behavior is modeled by the rate- and state-dependent friction (RSF) law with two state variables. Shorter critical slip distances of the state evolution would be about the contact junction size, while longer critical slip distances are close to the average diameter of gouge particles. The AE activities are evaluated by AE rate that is the number of AE events per unit sliding distance and the m-value that characterizes the amplitude distribution. As variations in AE activities and the evolution term ( $${b}_{1}$$ b 1 ) with the shorter critical slip distance highly correlate, AE activity may reflect the state of contact junction. While $${b}_{1}$$ b 1 increases with increasing water vapor from dry to humid, AE rate and the m-value are decreased. This may be caused by an increase in inelasticity of the contact junction deformation. Under wet conditions, $${b}_{1}$$ b 1 is similar to that under the humid condition, AE rate is further decreased but the m-value becomes significantly large. This is probably because the failure process of the contact junction changes to less brittle one, implying the impact of phase of water (vapor or liquid) on the brittleness of the failure processes of contact junction. Graphical Abstract

Methodology for Analyzing Powder-Based Fire Extinguishing and Its Optimization

Powder-based fire extinguishing methods are widely used to suppress fires of all kinds efficiently. However, these methods have several drawbacks, the most significant being the large powder residue left behind, which can complicate cleanup and damage sensitive equipment. The present paper investigates reacting flows and develops a methodology for analyzing the interaction of powder particles with fire, addressing both homogeneous and heterogeneous fire inhibition mechanisms. To achieve this, a simplified model was developed using the common principles of the general dynamic equation (GDE) and the population balance equation (PBE) coupled with the reacting flow equations. The model examines the interplay between the initial particles’ diameter and their extinguishing flow rate (concentration), also known as minimal extinguishing concentration (MEC), establishing the relation between the two. Notably, the relation exhibits three different zones, each influenced by different governing mechanisms of combustion inhibition, providing critical insights into optimizing powder-based extinguishing systems. A minimal value of the MEC is found where there is no significant change with the MEC in terms of particle diameter, and the chemical homogeneous mechanism is dominating. The methodology also offers a pathway for finding the maximal extinguishing particle diameter (MED) when the heterogeneous extinguishing mechanism acquires its maximal impact.There is no benefit with a larger particle diameter as it would not practically achieve better extinguishment, but would lead to a potential waste of powder and hence damage equipment. A significant advantage of using extinguishing powders with micro-sized/ultrafine particles is demonstrated where the homogeneous inhibition mechanism becomes predominant. The developed methodology and finding suggest that micro-sized powders are more effective in extinguishing fires, as they offer improved dispersion and reactivity, enhancing the overall efficiency of the fire suppression process. However, considering economic factors such as micron-sized-powder production cost and maintenance may require considering a shift of this set point.

High heterogeneity in the size distribution of the micellar fraction from in vitro digestions: sample preparation and reporting recommendations

AbstractBACKGROUNDUnderstanding the size and surface charge (ζ‐potential) of particles in the mixed micellar fraction produced by in vitro digestion is crucial to understand their cellular absorption and transport. The inconsistent presentation of micellar size data, often limited to average particle diameter, makes comparison of studies difficult. The present study aimed to assess different size data representations (mean particle diameter, relative intensity‐ or volume‐weighted size distribution) to better understand physiological mixed micelle characteristics and to provide recommendations for size reporting and sample handling.RESULTSDietary compounds (RRR‐α‐tocopherol, retinyl‐palmitate, β‐carotene, curcumin and naringenin) underwent a simplified in vitro digestion, whereas foods (spinach and red cabbage) were subjected to both a simplified and the INFOGEST 2.0 digestions. Dynamic light scattering was used to measure size and surface charge of the mixed micelles. A significant percentage of particles above the 200 nm filter cut‐off was observed, indicating aggregation and dynamic size changes in the mixed micellar fraction. Freezing of the mixed micelles notably enhanced the aggregation.CONCLUSIONThe determination of particle size in polydisperse mixed micellar fractions is challenging, and relying solely on average particle diameter can be misleading. Especially in more polydisperse samples, parameters such as polydispersity index and volume‐weighted distribution should accompany average particle diameter data. To minimize the effect of freezing on particle size, we recommend filtering the digesta after storage (freezing), as this leads to similar size distribution compared to mixed micellar fraction measured directly after digestion. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Analysis of TEM micrographs with deep learning reveals APOE genotype-specific associations between HDL particle diameter and Alzheimer's dementia.

High-density lipoprotein (HDL) particle diameter distribution is informative in the diagnosis of many conditions, including Alzheimer's disease (AD). However, obtaining an accurate HDL size measurement is challenging. We demonstrated the utility of measuring the diameter of more than 1,800,000 HDL particles with the deep learning model YOLOv7 (you only look once) from micrographs of 183 HDL samples, including patients with dementia or normal cognition (controls). This method was shown to be more efficient and accurate than conventional image analysis software. Using this method, we found a higher abundance of small HDLs in participants with dementia compared to controls in patients with the apolipoprotein E (APOE) ε3ε4 genotype, whereas patients with the APOE ε3ε3 genotype had higher variability in the abundance of different HDL subclasses. Our results show an example of accurate individual HDL particle diameter measurement for large-scale clinical samples, which can be expanded to characterize the relationship between disease risk and other nanoparticles in the sub-20-nm diameter size range.

Interaction of cesium compounds with abundant inorganic compounds of atmosphere: Effect on cloud formation potential and settling.

Experiments were conducted in controlled laboratory conditions to determine the size-resolved CCN (Cloud Condensation Nuclei) activity of sub micrometer-sized aerosols containing nuclear fission products (CsI and CsOH) and abundant ambient inorganic aerosols ammonium sulphates ((NH4)2SO4), ammonium chloride (NH4Cl), sodium nitrate (NaNO3), and sodium chloride (NaCl). The presence of these atmospheric-relevant compounds internally mixed with fission product compounds has the potential to affect the capacity of ambient particulates of aerosols to absorb water and function as CCN. Once in the atmosphere, the dynamics of airborne radionuclides and subsequently their fate gets affected by dry and wet deposition processes. The interplay of source and decay terms determines the transit of radioactivity and impacts its local and/or global spread. After being exposed to a sufficiently humid atmosphere, released cesium particles have a high potential to act as CCN. However, the CCN properties of the resulting mixed particles may be altered due to their interaction with atmospheric particles. DMT-CCN counter was used to acquire CCN activation curves with initial dry particle size variation (20-300 nm) for mixed particles (ratio 1:1) at 0.1-1 % supersaturation (SS). For a variety of particle sizes and mixtures of soluble materials, activation ratio curves were obtained under various SS conditions. From the study of CCN spectra, an estimate of the hygroscopicity parameter (κ) was made, which is sensitive to the chemical composition of aerosols. Under different SS conditions, the CCN activation diameters of mixed aerosols were found to be affected greatly in comparison to pure compounds. For the first time, the spectral efficiency of CCNs and the activation diameters of CsI and CsOH particles combined with important atmospheric aerosols were described at various SS levels. Terminal settling velocities for the mixed particles having a representative diameter as critical activation droplet diameter (wet diameter at particular SS), and varying effective density (based on droplet composition) were obtained and compared with the pure state of particles at different SS levels. The relative difference was significant for some combinations and SS conditions. Any modification in settling velocity ultimately impacts the particle's lifetime and deposition flux estimations. Hence neglecting the presence of atmospheric salts affects the accuracy of the source term estimates for a postulated nuclear reactor accident scenario. Data on these features is crucial for modelling the behavior of these particles in simulations. In the extremely improbable event of a containment breach occurring under severe nuclear accident conditions, the outcome has the potential to enhance environmental source-term estimations.

Extraction and characterization of spherical nanocellulose from sesame husks.

The objective of this study was to extract and characterize nanocellulose from sesame husks, which are typically discarded as waste by sesame processing facilities. However, these husks are rich in cellulose, presenting a valuable potential source for nanocellulose. Sesame husk cellulose (SHC) was initially isolated through a multi-step process that removed oil, hemicellulose, and lignin. Sesame husk nanocellulose (SHNC) was subsequently obtained via acid hydrolysis. Energy-dispersive X-ray (EDX) analysis revealed a purity of 99.32% for SHNC. The yields of SHC and SHNC were 25.16% and 9.17%, respectively. SHNC exhibited a lower surface charge (-27.2mV) compared to SHC (-15.5mV). FTIR confirmed the presence of characteristic cellulose bands. Dynamic light scattering (DLS) revealed average particle diameters of 2235nm for SHC and 108.1nm for SHNC. Atomic force microscopy (AFM) and field-emission scanning electron microscopy (FE-SEM) analyses showed that SHNC particles were spherical to oval-shaped, with average diameters of 78.41nm and 74.30nm, respectively. The crystallinity index was higher for SHNC (67.74%) compared to SHC (41.02%). Thermogravimetric analysis (TGA) indicated greater thermal stability for SHC (TMax 317°C) compared to SHNC (TMax 287°C). These results demonstrate the potential of sesame husks as a sustainable and valuable source of nanocellulose.

Deposition simulations of realistic dosages in patient-specific airways with two- and four-way coupling.

Inhalers spray over 100 million drug particles into the mouth, where a significant portion of the drug may deposit. Understanding how the complex interplay between particle and solid phases influence deposition is crucial for optimising treatments. Existing modelling studies neglect any effect of particle momentum on the fluid (one-way coupling), which may cause poor prediction of forces acting on particles. In this study, we simulate a realistic number of particles (up to 160 million) in a patient-specific geometry. We study the effect of momentum transfer from particles to the fluid (two-way coupling) and particle-particle interactions (four-way coupling) on deposition. We also explore the effect of tracking groups of particles ('parcels') to lower computational cost. Upper airway deposition fraction increased from 0.33 (one-way coupled) to 0.87 with two-way coupling and 10µm particle diameter. Four-way coupling lowers upper airway deposition by approximately 10% at 100µg dosages. We use parcel modelling to study deposition of 4-20µm particles, observing significant influence of two-way coupling in each simulation. These results show that future studies should model realistic dosages for accurate prediction of deposition which may inform clinical decision-making.

Deep eutectic solvent-assisted carbon quantum dots from biomass Triticum aestivum: A fluorescent sensor for nanomolar detection of dual analytes mercury (Ⅱ) and glutathione.

Deep eutectic solvents (DESs) have attracted significant attention in recent years due to its environment friendly characteristics and its participation in the multi-heteroatom doping of carbon quantum dots (CQDs). In this work, we present a simple, fast, and environment-friendly microwave synthesis approach for the synthesis of DES-assisted nitrogen and chloride co-doped CQDs (N,Cl-CQDs) using a choline chloride-urea based DES. A biomass-based precursor, i.e., wheatgrass (Triticum aestivum), has been used as a carbon source. Transmission electron microscopy (TEM) showed the spherical shape with average 1.75nm particle diameter of prepared CQDs. The surface functionality and chemical composition of prepared N,Cl-CQDs were determined by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopic techniques. The N,Cl-CQDs obtained a high quantum yield (QY), i.e., 36%, compared to undoped CQDs, which were synthesized in an aqueous medium (QY=15%). The prepared N,Cl-CQDs showed significant properties such as excellent photostability, favorable water solubility, and high optical stability. N,Cl-CQDs were used as sensing platform for the detection of Hg2+ ions and GSH with LOD value of 39nM and 43nM, respectively. The fluorescence quenching mechanism was confirmed by several photophysical parameters, such as average lifetime values, radiative rate constant (k r ), non-radiative rate constant (knr) and others. Furthermore, the current sensing system's viability is also tested in a river water sample for the detection of Hg2+. The N,Cl-CQDs prepared in this study exhibited a reduced detection limit and a broad linear range by an easy, environmentally friendly, and rapid method for detecting GSH and Hg2+ ions.

Particle impact in high-pressure homogenizer valves – a step towards understanding wear and cell breakup in food and beverage processing

In many liquid food processing applications using high-pressure homogenizers (HPHs), particles impact with the solid surfaces of the homogenization device. This may lead to costly wear. For some applications, impact is also postulated to control the desired cell disruption. This contribution uses computational fluid dynamics to study impact of particles on solid surfaces in HPHs, as a step towards design optimization. Effects of particle diameter, density, homogenizing pressure, and impact distance are studied. Results show impacts both on the forcer and on the impingement ring. Few particles hit the forcer, at low velocities and with low angles (‘bracing impacts’). More particles hit the impact ring. These impacts are with higher velocities and typically occur head-on. The effect of both homogenizing pressure and impact ring distance scales according to a previously suggested stagnation pressure model. Results are discussed in the light of wear and cell disruption observations.

Dynamics of nanoparticle tracers in supercooled nanoparticle matrices.

We investigate the dynamics of tracer nanoparticles in bulk supercooled nanoparticle matrices using confocal microscopy. We mix fluorescent (tracer) and undyed (matrix) charged-stabilized polystyrene nanoparticles with tracer-to-matrix particle size ratios δ = 0.34, 0.36, 0.45, 0.71 at various matrix volume fractions ϕ. Single-particle and collective dynamics were obtained from particle-tracking algorithms and differential dynamic microscopy (DDM), respectively. The long-time behavior of the tracer mean-square displacement (MSD) and the shape of the distributions of particle displacements depend on δ and ϕ. At sufficiently large ϕ, small tracers (δ ≤ 0.36) remain mobile and subdiffusive but large tracers (δ ≥ 0.45) are dynamically arrested. The relaxation times determined from the intermediate scattering function (ISF) increase with δ and ϕ. Anomalous logarithmic decays in the ISF are observed for tracers of size δ ≤ 0.36 over a length scale of four to ten matrix particle diameters. These results provide insight into how penetrant size affects the transport of nanoparticles in porous media with soft interparticle interactions.

Algebraic Depletion Interactions in Two-Temperature Mixtures.

The phase separation that occurs in two-temperature mixtures, which are driven out of equilibrium at the local scale, has been thoroughly characterized, but much less is known about the depletion interactions that drive it. Using numerical simulations in dimension 2, we show that the depletion interactions extend beyond two particle diameters in dilute systems, as expected at equilibrium, and decay algebraically with an exponent -4. Solving for the N-particle distribution function in the stationary state, perturbatively in the interaction potential, we show that algebraic correlations with an exponent -2d arise from triplets of particles at different temperatures in spatial dimension d. Finally, simulations allow us to extend our results beyond the perturbative limit.

Experimental study on the impact load characteristics of a single-row pile dam against debris flow

A single-row pile dam is a type of rigid debris flow barrier structure. In order to reveal the mutual interaction effects between debris flow and a single-row pile dam and the distribution law of debris flow impact forces, an analysis of the correlation between debris flow density, characteristic particle size, and relative pile spacing (the ratio of pile gap size to debris flow characteristic particle diameter) and debris flow impact forces was conducted to obtain dimensionless parameters related to debris flow impact force and climbing height. These parameters were verified through flume model experiments to provide theoretical support for the engineering design of single-row pile dams. The results show that the impact force of the debris flow on the pile dam is mainly affected by the flow velocity, debris flow density, and relative pile spacing. The dimensionless parameters are introduced, and the semi-empirical expression of the impact load coefficient is established. The impact pressure coefficient of debris flow is classified into two categories, and the calculation model of impact load of a single-row pile dam is constructed. The research results can provide a theoretical basis and technical parameters for designing a single-row pile dam.

Novel Study of Reaction Kinetics and Mass Transfer in Bioreactor Modelling: Prediction of Bioethanol Fermentation Performance by Saccharomyces cerevisiae on Continuous Fixed Bed Biofilm Plug Flow Reactor

Bioethanol implementation as a renewable fuel has yielded economic, social, and environmental benefits, including reduced fossil fuel consumption, enhanced energy diversity and supply security, lower greenhouse gas emissions, and support for agricultural communities. These impacts underscore the importance of advancing innovation and optimizing processes to increase bioethanol production. Therefore, basic knowledge of chemical engineering in bioethanol fermentation is important to be learnt as a preliminary study, such as reaction kinetics and transport phenomena. This work studies the reaction kinetics and mass transfer in continuous fixed bed biofilm plug flow reactor modelling to predict anaerobic Saccharomyces cerevisiae fermentation performance, which is still not studied comprehensively. This modelling provides an overview of the influence of various independent variables, namely temperature, initial substrate concentration, cell concentration, superficial flow rate, reactor diameter, and solid particle diameter on various dependent variables, namely final product concentration, residence time, reactor length, reactor volume, product productivity, and pressure drop. The most sensitive parameters related to product productivity are temperature and cell concentration, so in its implementation, the temperature must be controlled at its optimum temperature, and the inoculum must be prepared with high cell concentration. For the next study, it is recommended to study the optimization of reactor design and operation (i.e. the pumping system, cooling system, and pH control of the reactor) and the implementation of the reactor on the plant scale. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Cerebral Embolic Protection in Patients Undergoing Left Atrial Appendage Closure.

(1) Background: Cerebral magnetic resonance imaging has reported new cerebral ischemic lesions after left atrial appendage (LAA) closure in about one- third of patients. Stroke occurs predominantly periprocedurally. This study evaluated the characteristics of embolized debris captured by the SENTINELTM cerebral embolic protection system in patients undergoing LAA closure; (2) Methods: Sixty filters of 30 consecutive patients undergoing LAA closure with the WATCHMAN FLXTM device were collected and captured debris was analyzed by histopathology and histomorphometry. Clinical outcome measures were disabling and non-disabling stroke within 72 h; (3) Results: In most filters, no material was captured. The predominant captured debris was acute or organized thrombi. The most common pattern was acute fibrin-rich thrombus, which was detected in 11/30 (33.3%) patients. Particles of heart tissue were seen in 6/30 (20%) patients, and foreign material was seen in one (3.3%) patient. The number of particles ranged from 0 to 52 per patient with a maximum of 31 in the distal and 21 in the proximal filter. Particle diameter ranged from 131 to 2614 µm. By logistic regression analysis, only protected time remained a multivariable predictor for larger particles (p = 0.039). There was no disabling or non-disabling stroke. Compared to transfemoral aortic valve replacement, the number of particles is only about 1.5%. (4) Conclusion: LAA occlusion with the WATCHMAN FLXTM was associated with a very low number of embolized particles captured with the double-filter SENTINELTM embolic protection system and no periprocedural stroke.