Deposition Model Research Articles

Current Anti-Amyloid-β Therapy for Alzheimer's Disease Treatment: From Clinical Research to Nanomedicine.

Recent successive approval of anti-amyloid-β (Aβ) monoclonal antibodies as disease-modifying therapies against Alzheimer's disease (AD) has raised great confidence in the development of anti-AD therapies; however, the current therapies still face the dilemma of significant adverse reactions and limited effects. In this review, we summarized the therapeutic characteristics of the approved anti-Aβ immunotherapies and dialectically analyzed the gains and losses from clinical trials. The review further proposed the reasonable selection of animal models in preclinical studies from the perspective of different animal models of Aβ deposition and deals in-depth with the recent advances of exploring preclinical nanomedical application in Aβ targeted therapy, aiming to provide a reliable systematic summary for the development of novel anti-Aβ therapies. Collectively, this review comprehensively dissects the pioneering work of Aβ-targeted therapies and proposed perspective insight into AD-modified therapies.

Research on thermal evolution of polydimethylsiloxane flexible sample with a practical 3-D FIB power deposition model

Research on thermal evolution of polydimethylsiloxane flexible sample with a practical 3-D FIB power deposition model

X-Ray Energy Deposition Model for Simulating Asteroid Response to a Nuclear Planetary Defense Mitigation Mission

In the event of a potentially catastrophic asteroid impact, with sufficient warning time, deploying a nuclear device remains a powerful option for planetary defense if a kinetic impactor or other means of deflection proves insufficient. Predicting the effectiveness of a potential nuclear deflection or disruption mission depends on accurate multiphysics simulations of the device's X-ray energy deposition into the asteroid and the resulting material ablation. The relevant physics in these simulations span many orders of magnitude, require a variety of different complex physics packages, and are computationally expensive. Having an efficient and accurate way of modeling this system is necessary for exploring a mission's sensitivity to the asteroid's range of physical properties. To expedite future simulations, we present a completed X-ray energy deposition model developed using the radiation-hydrodynamics code Kull that can be used to initiate a nuclear mitigation mission calculation. The model spans a wide variety of possible mission initial conditions: four different asteroid-like materials at a range of porosities, two different source spectra, and a broad range of radiation fluences, source durations, and angles of incidence. Using blowoff momentum as the primary metric, the model-initiated simulation results match the full radiation-hydrodynamics results to within 10%.

Size-segregated characteristics of water-soluble oxidative potential in urban Xiamen: Potential driving factors and implications for human health

Oxidative potential (OP), defined as the ability of particulate matter (PM) to generate reactive oxygen species (ROS), has been considered as a potential health-related metric for PM. Particles with different sizes have different OP and deposition efficiencies in the respiratory tract and pose different health risks. In this study, size-segregated PM samples were collected at a coastal urban site in Xiamen, a port city in southeastern China, between August 2020 and September 2021. The water-soluble constituents, including inorganic ions, elements and organic carbon, were determined. Total volume-normalized OP based on the dithiothreitol assay was highest in spring (0.241 ± 0.033 nmol min−1 m−3) and lowest in summer (0.073 ± 0.006 nmol min−1 m−3). OP had a biomodal distribution with peaks at 0.25–0.44 μm and 1.0–1.4 μm in spring, summer, and winter and a unimodal pattern with peak at 0.25–0.44 μm in fall, which were different from the patterns of redox-active species. Variations in the seasonality of fine and coarse mode OP and their correlations with water-soluble constituents showed that the size distribution patterns of OP could be attributed to the combined effects of the size distributions of transition metals and redox-active organics and the interactions between them which varied with emissions, meteorological conditions and atmospheric processes. Respiratory tract deposition model indicated that the deposited OP and the toxic elements accounted for 47.9 % and 36.8 % of their measured concentrations, respectively. The highest OP doses and the excess lifetime carcinogenic risk (ELCR) were found in the head airway (>70 %). However, the size distributions of OP deposition and ELCR in the respiratory tract were different, with 63.9 % and 49.4 % of deposited ELCR and OP, respectively, coming from PM2.5. Therefore, attention must be paid to coarse particles from non-exhaust emissions and road dust resuspension.

Simplified models of aerosol collision and deposition for disease transmission

Fluid-mechanics research has focused primarily on droplets/aerosols being expelled from infected individuals and transmission of well-mixed aerosols indoors. However, aerosol collisions with susceptible hosts earlier in the spread, as well as aerosol deposition in the nasal cavity, have been relatively overlooked. In this paper, two simple fluid models are presented to gain a better understanding of the collision and deposition between a human and aerosols. The first model is based on the impact of turbulent diffusion coefficients and air flow in a room on the collisions between aerosols and humans. Infection rates can be determined based on factors such as air circulation and geometry as an infection zone expands from an infected host. The second model clarifies how aerosols of different sizes adhere to different parts of the respiratory tract. Based on the inhalation rate and the nasal cavity shape, the critical particle size and the deposition location can be determined. Our study offers simple fluid models to understand the effects of geometric factors and air flows on the aerosol transmission and deposition.

Discrepant mass accumulation rates of sediments in the South Pacific Ocean from 230Th and 3He measurements

A common technique for determining the mass accumulation rates of marine sediments is through measurements of constant flux proxies. These proxies, like unsupported 230Th and extraterrestrial 3He, are buried at a known rate at the seafloor, and thus their concentration in sediments is inversely proportional to the vertical mass accumulation rate of ambient sediments. These two proxies have varied assumptions regarding their behavior that have been difficult to test, particularly in regions of very low sedimentation. We present new measurements of helium and thorium isotopes in coretop sediments from the South Pacific Gyre. Our main finding is that 230Th- and 3He-derived mass accumulation rates of these sediments differ by a factor of 2–10, with 230Th-based mass accumulation rates systematically higher than those derived from 3He. While the final cause of the discrepancy is difficult to elucidate, we suggest that up to a factor of 2 worth of the sedimentary 230Th deficit can be explained by lateral transport of 230Th, while the remainder must be explained by other processes, such as ancient coretops undercorrected for post-depositional 230Th decay. Regardless of the mechanism, our findings have critical implications for the application of constant flux proxies in the South Pacific Gyre, with one example being the calibration of dust deposition models in this region. Ultimately, additional testing is required to determine the accuracy of the 3He and 230Th techniques for estimating sediment accumulation rates in regions of the open ocean with extremely low sedimentation rates.

In situ multi-perspective scanning of 3D particle deposition on flat plates with film cooling and determination of practical model parameters

A practical strategy for three-dimensional morphology measurement in the particle deposition process is of great importance to deepen the understanding of deposition physical processes. Due to the methodology limitations, it is difficult to obtain the formation process of deposition morphology. In this work, an in situ multi-perspective scanning (MPS) method using structured light was developed to capture the formation process of deposits. The point cloud registration algorithm was adopted to reconstruct the deposition morphology. Based on the validation results of Vernier caliper, the MPS method provides an uncertainty of ±0.056 mm at 4 mm. To verify the potential application of in situ measurement in gas turbine diagnostics, MPS method was preliminarily applied to the flat plate test with film cooling in particle-laden flow. The application demonstrated that this method successfully reconstructed the deposition morphology on a flat plate in the presence of film cooling. Furthermore, the obtained morphology results revealed that deposition roughness lied in the 0.35–0.56 mm and increased with an increase of blowing ratio. Additional comparisons with film cooling effectiveness showed the deposition distribution was related to the film cooling process. The detailed three-dimensional (3D) deposition morphology determined the mean curvature and mass of deposits, which may improve the prediction accuracy of deposition models in numerical simulations.

Platinum Electrocatalyst Promoting Redox Kinetics of Li2S and Regulating Li2S Nucleation for Lithium-Sulfur Batteries.

The development of lithium-sulfur batteries (LSBs) is impeded by the shuttle effect of polysulfides (LiPSs) and the sluggish nucleation of Li2S. To address these challenges, incorporating electrocatalysts into sulfur host materials represents an effective strategy for promoting polysulfide conversion, in tandem with the rational design of multifunctional sulfur host materials. In this study, Pt nanoparticles are integrated into biomass-derived carbon materials by solution deposition method. Pt, as an electrocatalyst, not only enhances the electrical conductivity of sulfur cathodes and effectively immobilizes LiPSs but also catalyzes the redox reactions of sulfur species bidirectionally. Additionally, Pt helps regulate the 3D deposition and growth of Li2S while reducing the reaction energy barrier. Consequently, this accelerates the conversion of LiPSs in LSBs. Furthermore, the catalytic ability of Pt for the redox reactions of sulfur species, along with its influence on the 3D deposition and growth of Li2S, is elucidated using electrochemical kinetic analyses and classical models of electrochemical deposition. The cathodes exhibit a high initial specific capacity of 1019.1mAhg-1 at 1C and a low decay rate of 0.045% over 1500 cycles. This study presents an effective strategy to regulate Li2S nucleation and enhance the kinetics of polysulfide conversion in LSBs.

Simulation of Hydrate Particles Aggregation and Deposition in Gas-Dominated Flow

Summary Owing to low-temperature and high-pressure production environments, hydrate generation, accumulation, and deposition are prone to occur in deepwater oil and gas production wells and transportation pipelines, leading to pipeline blockage and threatening the safety of oil and gas production. To explore the aggregation mechanism and deposition law of hydrate particles in the main gas diversion pipeline, this study considered the adhesion effect of hydrate particles and established a hydrate particle aggregation and deposition model based on theory and experiments. The coupled computational fluid dynamics-discrete element method (CFD-DEM) is used in the simulation calculation. The simulation results were compared with the relevant experimental results, and maximum and average errors of 9.48% and 4.56% were observed, respectively. It was found that the main factor affecting the aggregation of hydrates is the adhesion between particles. As the subcooling temperature increased, the aggregation and adhesion of the hydrate particles increased to varying degrees. The tangential adhesion force between the hydrate aggregate particles was significantly greater than the normal adhesion force, and the adhesion force between the particles gradually increased from the surface to the interior of the aggregates. The coordination number of the hydrate particles can quantitatively characterize the degree of aggregation and is affected by many factors, such as adhesion. By studying the particle coordination number, the evolution of hydrate accumulation and deposition under different conditions can be summarized. Based on the simulation results, the mathematical relationship between different dimensionless numbers and hydrate deposition ratio (HDR) was calculated, and an expression that can predict the HDR was obtained, with an average relative error of 10.155%. This study provides a theoretical basis for predicting the aggregation and deposition of hydrate particles in gas-dominated systems and a reference for the development of hydrate prevention and control plans.

Superheater ash deposit ageing – Impact of melt fraction on morphology and chemistry

The initial melting behaviour of synthetic ash deposits, with a focus on how the amount of melt formed, affects the final deposit morphology, was studied. Binary and ternary reciprocal deposits were exposed to a temperature gradient with varying exposure time, steel temperature, and furnace temperature. Two different archetype deposit morphologies emerged. The final deposit morphology was identified to depend on the amount of melt formed during the experiment. A skeletal deposit morphology developed in systems with less than 30 wt-% melt. Short-term experiments proved that the formation of the skeletal structure is accelerated by the presence of melt, accumulating at contact points of distinct particles. If melt fractions exceeded 30 wt-%, a molten morphology developed, as the amount of melt present was sufficient to fill the pores within the deposit. For molten deposits of ternary reciprocal systems, enrichment of K in the formed melt and concurrent movement toward the steel was observed. The results confirmed a deposit ageing mechanism that has been proposed earlier, based on full-scale superheater deposit samples. The experiments showed that deposit melting and ageing behaviour are strongly connected, as the two identified morphologies differed in their ageing behaviour. The presented results improve the understanding of the initial melting behaviour of deposits and illustrate the connection between deposit morphology and deposit ageing. The results can be utilised as input data for deposition models and help in predicting the final deposit morphology and its associated ageing behaviour, aiding boiler operators and manufacturers dealing with deposit-related issues.

Geometrical exponents of contour loops on ballistic deposition model with power-law distributed noise

In this paper, we study geometrical properties of contour loops to characterize the morphology of the porous ballistic deposition model with power-law distributed noise. In this model, rod-like particles with variable lengths instead of homogeneous particles are deposited, the length of each rod, l, is determined by a power-law distribution, P(l)∼l−(μ+1), and μ indicates the power-law strength exponent. The accumulation of rods with different lengths leads to a porous structure. The porous structure is converted into contour loops by using the Hoshen–Kopelman algorithm and the complexity and fractal features of the loops are investigated. On the other hand, the distributions of loops indicating the porosity distribution of the growth rough surfaces are investigated. The fractal dimension of the contour set, d, the fractal dimension of each loop, Df, cumulative distributions exponent of areas, ξ, and the perimeter distribution exponent, τ, are calculated for the investigated porous structures. Our results show that enhancement of μ exponent and appearance of the Gaussian ballistic deposition model leads to reduction of structure porosity and enhancement of contour loops area and perimeter. The fractal dimension of the contour set, and the fractal dimension of each loop increases by enhancement of μ exponent. Distributions of loops and geometrical exponents of contour loops in different μ exponent are determined. The results indicate that the hyperscaling relation and Zipf’s law hold for μ≥μc=3 which power-law distributed noise approaches to Gaussian one.

Analysis of the Genetic Model of the Extremely Narrow Channel Shallow Water Delta in DL-A Oilfield, Bohai Bay Basin.

In recent years, the oil and gas reserves discovered in shallow water deltas in China have continued to grow. The research on shallow water delta deposition models and depositional genesis is becoming more and more mature. In this latest discovery, a unique type of extremely narrow channel shallow water delta deposit was found at the top of the V oil group in the lower part of the Minghuazhen Formation during the Neogene period at DL-A Oilfield, located in the Bohai Bay Basin. The width of most single channels in this deposit measures between 100 and 200m, which is relatively rare and differs from existing research. To better understand this unique narrow channel shallow water delta deposit, a range of analysis methods were conducted including trace element analysis, major element analysis, grain size analysis, core observation, casting thin section observation, 3D seismic analysis, and other methods. These analyses were used to determine the sedimentary environment and sedimentary genesis of the deposit in the study area. The results show the following: (1) The top of the V oil group in the lower part of Minghuazhen Formation was deposited with a strong oxidizing environment. In the early stage, the climate was dry and cold, and gradually changed to warm and humid in the late stage. (2) Due to the frequent exposure to the surface, obvious weathered surfaces and sedimentary discontinuities were observed on the cores; the particle size analysis shows that the lamina types developed in the study area are clastic-clay laminae and clay-clastic laminae, which are mostly developed in shallow lakes area. (3) Observations of cores and thin sections also indicated that the hydrodynamic conditions frequently changed in the study area, alternating between strong and weak hydrodynamic conditions in a short period due to the alternating occurrence of flood and dry periods during the rainy season. Weak hydrodynamic conditions and slow water flow result in insufficient undercutting and sidecutting of rivers. The alternating occurrence of flood periods and dry periods has led to the development of crevasse splays and frequent river channel diversions, resulting in the inability of long-term stable development of the river channel. Besides, the change of water level has also led to the rebuilding of the river. Therefore, the multiple effects led to the formation of an extremely narrow channel shallow water delta. The accuracy of the sedimentary model is verified by a comparative study of the Shaliu River and Buha River in the modern Qinghai Lake. The new extremely narrow channels deposition model proposed this time further improves the deposition theory. At the same time, the modern depositional characteristics of the Shaliu River and Buha River also reveal the reservoir deposition between channels that cannot be distinguished by seismic data, providing guidance for the development of oil and gas in the study area.

Towards modeling of ZrO2 atomic layer deposition at reactor scale based on experimental kinetic approximation

In this study, the growth kinetics of ZrO2 via the atomic layer deposition (ALD) using a mixed alkylamido-cyclopentadienyl zirconium precursor are proposed based on experimental data to evaluate the film growth behavior using reactor-scale simulation. In the ALD process, the hydroxyl concentration on the targeted surface govern the saturated growth per cycle values. However, we found that the bulkiness of remaining ligands on adsorbed species hinders the adsorption of Cp-Zr molecules.Considering this phenomenon, we proposed a kinetic model by calculating the energetic terms to quantify the “steric hindrance effect” of the first elementary surface reaction of CpZr(N(CH3)2)3 precursor (Cp-Zr), which enables the film growth prediction with the reactor-scale computational fluid dynamic (CFD) model.According to the experimental ALD process, the film growth was found to be influenced by the steric hindrance factor, especially at the temperature range from 150 °C to 250 °C, but the hindrance effect decreases with increasing temperature and disappears at 300 °C. The effective activation energy of the adsorption of Cp-Zr molecules on Si substrate was estimated to be 0.175 eV. Further understanding of the kinetic of ZrO2 deposition in this study is estimated to contribute to the optimization of the high-k metal oxides ALD deposition processes.

Study of poly-disperse aerosols deposition in turbulent flow with different Reynolds numbers

The turbulent deposition mechanism is one of the main mechanisms of aerosol deposition in nuclear power plant tubes. An experimental study of poly-disperse aerosol deposition in a horizontal tube is conducted, where the nominal Reynolds number (Re) is in a range of 3600–200,000. The aerosol deposition velocity first increases and then decreases with the increase of Res, and at high Re, particle rebound occurs during aerosol deposition in the tube. When the Re is low, the aerosol deposition velocity increases with the increase of aerosol diameter. When the Re is greater than 60,000, the deposition velocity first increases and then decreases with the increase of aerosol diameter due to particle surface rebound. A new aerosol deposition model has been developed by establishing the energy conservation equation of the rebounded particles in the viscous sublayer. The calculated results of the new model are in good agreement with these experimental results, and the error between the aerosol deposition velocity calculated by the model and experimental results is between −60% and 150%.

Devising of a method for improving anode capacity for an all-iron flow battery

A comprehensive study of the impact of electrode design and iron deposition mechanism on the enhancement of the capacity of an all-iron redox flow battery (AIFB) has been conducted. The research is focused on revealing the complex interaction between electrode architecture, iron deposition behaviour, and battery capacity. Using a developed experimental setup, five different electrode designs are investigated. These designs include variations in the arrangement of carbon felt (CF) and non-woven fabric (NWF) layers and critical factors affecting iron deposition. Battery charge and discharge experiments were carried out under controlled conditions, simulating practical operating regimes with a current density of 50 mA/cm² and a compression ratio of 80%. The results demonstrate the influence of electrode design on iron deposition and, consequently, on battery capacity. The electrode configuration with two layers of CF and two layers of NWF exhibits a specific capacity exceeding 700 mA·h/cm². Analysis using scanning electron microscopy (SEM) complements the capacity determination results by providing valuable information about the spatial distribution of iron on the electrode surfaces. Furthermore, quantitative analysis using ZAF correction reveals uniform models of iron deposition on the surface of electrode E, indicating its potential for optimizing AIFB performance. This study provides a comprehensive understanding of the relationship between electrode design, iron deposition behaviour, and AIFB capacity. The results offer insights for improving electrode configurations, ultimately contributing to the development of efficient energy storage solutions

Modelling of Sediment Transport and Deposition in Generating River-Mouth Closure: Oum-Errabia River, Morocco

River mouths are dynamic systems that can respond rapidly to both fluxes in fluvial water and sediment discharge and marine energy conditions, notably waves. On semi-arid wave-exposed coasts, the morphosedimentary behaviour of river mouths is particularly sensitive to variations in water discharge, which can be significantly influenced by climate variations, in addition to anthropogenic actions such as the construction of dams for water resource needs. In this climatic setting, an increasingly common consequence of decreasing river water discharge is the more or less prolonged closure of river mouths. Most studies have addressed river-mouth closure using analytical, parametric, numerical, or statistical models. The present study uses output from four numerical models to elucidate the hydrodynamic and sedimentary behaviour of the mouth of the Oum-Errabia River (catchment size: 35,000 km2), which debouches on the Atlantic coast of Morocco. The historical evolution of the river mouth and the impact of human interventions, such as the construction of dams, are discussed. The study also briefly discusses the impact of the recent closure of the river outlet, in response to particularly low water discharge, on the marine ecosystem and water quality. The modelling results covering a one-year simulation in this situation of closure indicate a deposition of 427,400 m3 of sediment in front of the mouth of the Oum-Errabia. Ensuring permanent river-mouth opening and tidal flushing and renewal of this river’s estuarine waters will necessitate costly regular dredging.

Reactive transport modeling of scale precipitation and deposition during incompatible water injection in carbonate reservoirs

Seawater injection is an efficient enhanced oil recovery (EOR) method that capitalizes on the chemical composition differences between the injecting seawater and in-situ formation water, which leads to physicochemical interactions between the rock and fluids. These rock and fluid interactions result in changes of rock wettability and subsequent improved microscopic sweep efficiency. However, the ion imbalance resulting from seawater injection and its incompatibility with the in-situ formation water may interfere with the rock and fluids equilibrium state, causing scale precipitation and subsequent deposition which can negatively impact rock quality, well productivity and reservoir performance. In this study, an accurate, robust, and general approach is presented by coupling a geochemical module with a compositional two-phase fluid flow model to handle reactive transport in porous media. The proposed coupled model, so-called ad-scale model, is capable of simulating carbonate rock dissolution and sulfate scale formation/deposition for evaluating reservoir performance under incompatible water injection. The model predictions were validated using experimental data. This model was also utilized to predict water injection rate into a carbonate formation. It was obtained that both the reacting and non-reacting component profiles were accurately predicted using the proposed coupled model. The water injection rate prediction was also validated and showed high accuracy with absolute error and coefficient of determination values of 9.02% and 0.99, respectively. In addition, a sensitivity analysis was performed on water composition, which showed a strong dependence of reservoir and well performance on water composition.Graphical abstractThis diagram elucidates what exactly happens during incompatible water injection in the mixing zones near the injection well (right half of the figure) or production well (left half of the figure) where most of the geochemical phenomena occur.

An experimental study on lung deposition of inhaled 2 μm particles in relation to lung characteristics and deposition models

BackgroundThe understanding of inhaled particle respiratory tract deposition is a key link to understand the health effects of particles or the efficiency for medical drug delivery via the lung. However, there are few experimental data on particle respiratory tract deposition, and the existing data deviates considerably when comparing results for particles > 1 μm.MethodsWe designed an experimental set-up to measure deposition in the respiratory tract for particles > 1 μm, more specifically 2.3 μm, with careful consideration to minimise foreseen errors. We measured the deposition in seventeen healthy adults (21–68 years). The measurements were performed at tidal breathing, during three consecutive 5-minute periods while logging breathing patterns. Pulmonary function tests were performed, including the new airspace dimension assessment (AiDA) method measuring distal lung airspace radius (rAiDA). The lung characteristics and breathing variables were used in statistical models to investigate to what extent they can explain individual variations in measured deposited particle fraction. The measured particle deposition was compared to values predicted with whole lung models. Model calculations were made for each subject using measured variables as input (e.g., breathing pattern and functional residual capacity).ResultsThe measured fractional deposition for 2.3 μm particles was 0.60 ± 0.14, which is significantly higher than predicted by any of the models tested, ranging from 0.37 ± 0.08 to 0.53 ± 0.09. The multiple-path particle dosimetry (MPPD) model most closely predicted the measured deposition when using the new PNNL lung model. The individual variability in measured particle deposition was best explained by breathing pattern and distal airspace radius (rAiDA) at half inflation from AiDA. All models underestimated inter-subject variability even though the individual breathing pattern and functional residual capacity for each participant was used in the model.ConclusionsWhole lung models need to be tuned and improved to predict the respiratory tract particle deposition of micron-sized particles, and to capture individual variations – a variation that is known to be higher for aged and diseased lungs. Further, the results support the hypothesis that the AiDA method measures dimensions in the peripheral lung and that rAiDA, as measured by the AiDA, can be used to better understand the individual variation in the dose to healthy and diseased lungs.

A Comparison of Newtonian and Non-Newtonian Models for Simulating Stenosis Development at the Bifurcation of the Carotid Artery

Blood is a shear-thinning non-Newtonian fluid in which the viscosity reduces with the shear rate. When simulating arterial flow, it is well established that the non-Newtonian nature is important in the smallest vessels; however, there is no consistent view as to whether it is required in larger arteries, such as the carotid. Here, we investigate the importance of incorporating a non-Newtonian model when applying a plaque deposition model which is based on near-wall local haemodynamic markers: the time-averaged near wall velocity and the ratio of the oscillatory shear index to the wall shear stress. In both cases the plaque deposition was similar between the Newtonian and non-Newtonian simulations, with the observed differences being no more significant than the differences between the selected markers. More significant differences were observed in the haemodynamic properties in the stenosed region, the most significant being that lower levels of near-wall reverse flow were observed for a non-Newtonian fluid.

An intermittent lithium deposition model based on CuMn-bimetallic MOF derivatives for composite lithium anode with ultrahigh areal capacity and current densities

An intermittent lithium deposition model based on CuMn-bimetallic MOF derivatives for composite lithium anode with ultrahigh areal capacity and current densities