Final Distribution Research Articles

The 3D Physics-Based Broadband Ground-Motion Simulation, including Topography Effects Causing Damage to Structures, for the 2022 Mw 6.6 Menyuan, China, Earthquake

ABSTRACT On 8 January 2022, Menyuan County, China, was struck by an Mw 6.6 earthquake that caused surface rupture in the epicentral area and severe damage to an important railway bridge. The earthquake was recorded by only one strong-motion station, which presents a challenge for quantitatively estimating the extent of the ground-motion distribution caused by this event. In this study, the spectral element method (SPECFEM3D code), which solves the elastodynamic equations and can capture the full physics of seismic-wave propagation, is employed for broadband (0–10 Hz) ground-motion simulations of this earthquake. A hybrid kinematic source is developed in which the final slip distribution combines a prescribed asperity model based on Interferometric Synthetic Aperture Radar data (as a source for low-frequency radiation) and a stochastic part (as a source for high-frequency radiation), which introduces spatial heterogeneities to the prescribed asperity model. The numerical approach is first validated by modeling the well-recorded 1994 Northridge earthquake before modeling the Menyuan earthquake. The simulated ground motion is compared with the only observed strong-motion station record, as well as with empirical Next Generation Attenuation-West2 ground-motion models. Then, topography effect in Menyuan earthquake is studied in detail. The simulated ground motions with and without surface topography indicate that the topography tends to focus and scatter the seismic wavefield, resulting in amplification of the ground shaking. The results show a significant correlation between the peak ground velocity (PGV) and topography. The PGV amplification caused by topography effects is period dependent, and its peak amplification reaches up to 50% within a typical resonance period (1–2 s). It could be inferred that the railway bridge probably vibrated in resonance and suffered severe damage owing to the amplified long-period ground motion caused by the topography.

Electrochemical corrosion behavior of X80 pipeline steel welded joints fabricated by ultrasound-assisted submerged arc welding in CO2-saturated solution

In this study we investigated the electrochemical corrosion behaviors of X80 pipeline steel welded joints fabricated by ultrasound-assisted submerged arc welded (UASAW) joints in CO2-saturated solution. The microstructures of the UASAW joints were analyzed by using metallographic microscopy. Corrosion behavior of UASAW joints was investigated using immersion test, electrochemical polarization, and electrochemical impedance spectroscopy (EIS). The corrosion morphologies and products were characterized by scanning electron microscopy (SEM), energy dispersive spectroscope (EDS) and X-ray diffraction. Metallographic and the corrosion mechanism of UASAW was systematically studied. The investigation results showed that the microstructure of the UASAW weld zone is mainly composed of acicular ferrite and a little granular bainite. The minimum microhardness is obtained in fusion zone (FZ) because of many alloying elements dominated in the final precipitate distribution. Pitting corrosion resistance of the strong vibration region in FZ is attributed to the decline in active sites of the bainite, the UASAW had beneficial effect on the improvement of pitting corrosion resistance of X80 pipeline steel weldment.

Spatial dispersal in chemostat systems with agent-based asymmetry

This paper considers chemostat consumer-resource systems in which the consumer disperses between spatial patches and acts as an agent. Using the theory of dynamical systems and the method of graphs, we demonstrate global stability of steady states in the model. It is shown that dispersal of the consumer and clustering mode of patches are important for persistence of the consumer, while asymmetry in the dispersal determines the final distribution of consumer in the system. Moreover, appropriate asymmetry could make the consumer persist in sink patches, and could make the consumer approach a total population abundance higher than that without dispersal. A novel finding of this work is that agent-based selection on asymmetry could make the consumer evolve to the maximal abundance. Numerical simulations on the model reproduce radiograph/CT of COVID-19 patients in both figures and animations. Our research has potential applications in computer-aided diagnosis and treatment.

A numerical modeling framework for predicting the effects of operational parameters on particle size distribution in the gas atomization process for Nickel-Silicon alloys

Gas atomization is utilized to produce good-quality metal powders. A numerical modeling framework is developed to simulate the gas atomization process. A two-phase VOF flow model in OpenFOAM is applied to track the primary breakup of the melt stream by a high-speed gas flow. The generation of primary melt droplets is extracted from the VOF field. A Lagrangian-Eulerian multiphase flow model in Ansys Fluent is adopted to track the secondary breakup of the primary melt droplets under the high-speed gas flow. The final particle size distribution is obtained by analyzing the particles sampled at the outlet of the atomization chamber. The process of gas atomization can be affected by many factors such as the atomization equipment, operating parameters, and material properties. Sensitivity analysis is conducted through modeling to investigate the effects of these factors on particle size distribution. The model predictions are validated by specially designed gas-atomization experiments.

Star-forming environments in smoothed particle magnetohydrodynamics simulations II: re-simulating isolated clumps to determine equivalence of extracted clumps and parent simulations

ABSTRACT What is the numerical reproducibility of a stellar system (including its discs) when evolving only a subset of (partially-evolved) smoothed particle hydrodynamics (SPH) particles? To investigate this, we modelled the evolution of 29 star-forming clumps that were extracted from our previous simulations that investigated the formation and early evolution of low-mass star clusters. These clumps were evolved using a three-dimensional smoothed particle radiation magnetohydrodynamics code, where we included or excluded non-ideal magnetohydrodynamics to match the cluster simulation. While star formation proceeded as expected, we were unable to identically reproduce any of the systems present at the end of the cluster simulations. However, the final distributions of stellar mass, stellar system mass, disc mass, and disc radii were reproduced statistically; unfortunately, the distribution of average magnetic field strengths in the discs was not reproduced statistically, but this may be a result of our updated algorithms governing the evolution of the magnetic field. Therefore, given that our clumps yield stellar masses that are statistically similar to those in the original low-mass star clusters, we have demonstrated that we can statistically reproduce systems (aside from their magnetic field strength) by evolving a subset of SPH particles. Therefore, clumps such as these can be used as initial conditions to investigate the formation of isolated stars from less-contrived initial environments.

A discrete model for layered growth

We present a discrete model that captures the fundamental properties of layered deposition in a minimal setting. The model is based on simplified kinematics and allows for the onset of incompatible deformations between discrete layers of a growing stack. Thanks to the discrete nature of the model, we obtain an averaged formulation of mechanical equilibrium for the growing stack, leading to closed-form solutions that are both analytically simple and physically transparent. In particular, we are able to explain the origin of residual stress by the accumulation of incompatible deformations between adjacent layers. The model can also be regarded as an elementary approximation of additive manufacturing. Within this context, we are able to formulate the technologically relevant inverse problem that provides the deposition protocol required to produce a desired state of internal stress in an additively-manufactured stack. Another important aspect analyzed in the work is the role played by an ideal “glue” between the layers, whose presence is fundamental to prevent their sliding and whose mechanical behavior can quantitatively influence the final stress distribution in the stack. The simplicity of the model makes it possible to highlight how the controls exerted during deposition will have qualitative or quantitative effects on the final stress state of the stack.

Derived Environmental Impacts of Organic Fairtrade Cocoa (Peru) Compared to Its Conventional Equivalent (Ivory Coast) through Life-Cycle Assessment in the Basque Country

There is a global need to create an environmentally low-impact and socially fair international food and agriculture system. Specifically, in the case of chocolate, since it is difficult to produce locally in consumer countries, the socio-economic impact and benefits of its production have long been unfairly distributed. This research analyses the differences between the global environmental impacts of Fairtrade-certified and organically produced cocoa (from Peru), sold in the form of a chocolate bar purchased in the Basque Country (Europe), and the respective average conventional product made with non-organic cocoa beans (from Ivory Coast). Life-cycle assessment (LCA) methodology was used to calculate five impact categories, while ReCiPe 2016 Midpoint Hierarchist was used to analyse the global warming potential (GWP), terrestrial ecotoxicity (TE), and environmental footprint (ENVF, for land use); AWARE was used to measure the water footprint (WF); and cumulative energy demand (CED) assessed energy footprint (EF). The selected functional unit (FU) is 1 kg of final chocolate bar (72% cocoa), extrapolating the characteristics of a 150 g bar. The system boundaries take into account a cradle-to-gate LCA covering the following phases: the production of ingredients, the processing of cocoa paste, transportation and packaging, the manufacture of the chocolate, and its final retail distribution. The results show that certified Organic Agriculture and Fairtrade (OA&FT) chocolate had an average global warming potential (GWP) of 3.37 kg CO2-eq per kilogram, 57.3% lower than Conventional Agriculture (CA)-based chocolate, with the greatest reduction associated with the production of ingredients, at −71.8%. The OA&FT chocolate studied had an 87.4% lower impact in the category of terrestrial ecotoxicity (TE) than that of the CA-based chocolate, yielding 13.7 and 108.6 kg 1,4-DCB per kilogram, respectively. The greatest reduction in the TE impact category also occurred for the OA&FT chocolate in the ingredient production phase, at 93%. Reductions in energy footprint (EF) and water footprint (WF) were also observed in the OA&FT product (21% and 5%). In contrast, although OA&FT processing drastically reduced the associated environmental loads, an increase in packaging and transport phase impacts was observed in the GWP and TE categories (95% and 107%, respectively). Similarly, an increase of 18.7% was observed in the land use footprint for the OA&FT chocolate. The greater need for cropland is compensated by the reduction of 449.02 kg 1,4-DCB·person−1 year−1 in the TE category. This research shows that replacing the current consumption of CA cocoa with OA&FT cocoa has the potential to reduce the GWP by 21.95 kg CO2-eq·person−1·year−1, reducing the current Basque average emission range of 8.4 tCO2-eq·year−1 by 0.26%. As a future subject to study, it was also found that the impact of long-distance maritime transportation and packaging could still have the potential to be reduced, it currently being the cause of up to 11% of the GWP from OA&FT cocoa.

Kiln-drying effectiveness as influenced by moisture content and density variation within a Scots pine timber batch

ABSTRACT Sorting of sawn timber batches is crucial for efficient kiln-drying. This study aimed to verify the hypothesis of different drying attributes of 25 mm thick sapwood and mixed Scots pine boards sawn from a group of butt, second, and top logs and assess the effects of kiln-drying. Three options dry-bulb temperature were taken into account. The drying results were evaluated based on the final moisture content distribution, changes in the cross-sectional dimensions of the sawn timber, drying time, and unit heat consumption. Correlations between sawn timber features, drying temperature, and drying results were analyzed using non-parametric statistical tests. The study proved the dependence of the initial moisture content and wood density variation of Scots pine sawn timber on the log type and the position on the round timber cross-section. The variation of drying attributes of the sapwood and mixed 25 mm Scots boards is insignificant in the final moisture content distribution and cross-sectional dimensions. However, green sorting may have only a beneficial effect on drying time and heat consumption.

Effects of gradient structures of cathode catalyst layers on performance and durability of proton exchange membrane fuel cells

Improving performance and durability of proton exchange membrane fuel cells (PEMFC) is crucial for promoting commercial applications. Deep understanding of the underlying degradation mechanisms is still lacking. In this study, a two-way coupling performance-degradation model is established by incorporating one-dimensional (1D) Platinum (Pt) degradation model into 1D PEMFC performance model, which can predict Pt degradation phenomenon considering Pt dissolution, Pt2+ diffusion and reprecipitation in cathode catalyst layers (CCLs) and resulting performance loss. Effects of gradient CCL structures in terms of ionomer weight, Pt loading and Pt particle size on degradation and performance are investigated. The results show that multi-layer CCLs with more ionomer, more Pt loading, and/or smaller particles near membrane have higher performance, while the opposite gradients present enhanced anti-degradation capacity. Wave-like spatial distributions of Pt mass retention are observed in gradient CCLs, with significant difference across the sub-layer interface. Combined effects of two gradient distributions are also investigated. It is found that for performance, simply add-up roles are followed, namely combining two gradient distributions with higher performance can obtain higher performance, and vice versa. For durability, synergy effects are identified, in which two gradient structures with opposite final Pt mass distribution have competitive influence on Pt2+ local transport, with local Pt2+ diffusion suppressed, the catalyst distribution uniformity improved and performance loss alleviated. The gradient CCL structure considering the balance of performance and durability is identified based on 28 structures studied. Such add-up roles for performance and synergy effects for durability provide new insights for improving the design of PEMFCs.

A novel constitutive model for the concrete face slab of a CFRD and the numerical simulation of its seismic behavior

AbstractWith the rising demand for hydropower energy, China has built numerous concrete‐faced rockfill dams (CFRDs) with considerable heights. The potential failure pattern of the concrete face slab is the key to the safety of the anti‐seepage system. However, engineers commonly employ an elastic relationship to model the concrete face slab for simplicity, which induces inaccurate estimation of the face slab's stresses, especially under seismic conditions. On the other hand, the existing elastoplastic models for concrete often require complex derivation of the necessary formula and thus are difficult to apply to finite element (FE) analysis. Under the comprehensive action of the upstream water, supporting rockfill, and surrounding mountains, the damage mode of the quasibrittle concrete slab is not a tensile mode but a compressive shearing mode. Therefore, it is urgent to establish an elastoplastic model that is adapted to the actual working environment of the slab and easy to apply. To this end, a generalized plasticity model is developed within the phenomenology modeling concept, which is validated at both the experimental level and application level. The results indicate that three‐dimensional stress‒strain behaviors, such as the strength nonlinearity, prepeak dilatancy, and postpeak softening, can be effectively captured. In addition, the seismic characteristics of a 200‐m high CFRD are numerically investigated. The findings show that the slab's stress accumulation can be reflected during the earthquake and that the final stress distribution conforms to the field observations. The conclusions of this paper provide a reliable reference for the seismic resistance design of CFRDs.

Probing the Short-Distance Structure of the Quark-Gluon Plasma with Energy Correlators.

Energy-energy correlators (EECs) are promising observables to study the dynamics of jet evolution in the quark-gluon plasma (QGP) through its imprint on angular scales in the energy flux of final-state particles. We carry out the first complete calculation of EECs using realistic simulations of high-energy heavy-ion collisions and dissect the different dynamics underlying the final distribution through analyses of jet propagation in a uniform medium. The EECs of γ-jets in heavy-ion collisions are found to be enhanced by the medium response from elastic scatterings instead of induced gluon radiation at large angles. In the meantime, EECs are suppressed at small angles due to energy loss and transverse momentum broadening of jet shower partons. These modifications are further shown to be sensitive to the angular scale of the in-medium interaction, as characterized by the Debye screening mass. Experimental verification and measurement of such modifications will shed light on this scale and the short-distance structure of the QGP in heavy-ion collisions.

Categorization of Spatial and Temporal Ejecta Outcomes in Binary Systems Based on Variations of the Didymos System

With the increasing number of binary asteroid systems being discovered, ejecta studies must expand from solely investigating single-body systems to modeling more complex multiple-body systems. For example, the Double Asteroid Redirection Test provides an opportunity to study the dynamics of a debris cloud around Didymos and Dimorphos, a near-Earth binary asteroid system. Here we simulate 72 variations on the Didymos system in order to categorize types of ejecta outcomes and analyze the influence of the varying system parameters on each outcome. We have varied five parameters: the system separation, the mass ratio between the two bodies, the impact location, the target-body shape, and the target-body rotation period. The resulting provenance maps of the final ejecta distributions were blindly sorted into five categories, while the resulting cumulative distribution functions (CDFs), describing the rate at which particles hit the surface, were blindly sorted into eight categories. We count the occurrences of the parameter values in each of the categories and apply a Cramer’s V statistical test to evaluate the significance of the association between each varied effect and the overall grouping of the provenance maps and CDFs. We conclude that more dominant effects, such as a small rotation period, produce notably similar ejecta distributions that result in being assigned to the same category. Less dominant effects, such as target-body location, are sorted into several categories due to the larger influence of varying dominant effects.

Precise Synthesis of Tetrablock Copolymers of Different Acrylamide Derivatives via Iterative Aqueous Cu(0)-Mediated Polymerization

The accessibility of specific synthesis of tetrablock copolymers is reported. In a specific synthesis, four acrylamide monomers are gradually added using an iterative aqueous Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) method. Essential to the success of this approach is the ability to design and polymerize ABCD copolymer sequence with no need for immediate purification steps. The simple in-situ sequential polymerization method allowed for essentially perfect control of accurately well-defined tetrablock copolymers, which are composed of four tiny blocks, each of which contains an average of ten functional monomer units of acrylamide derivatives, resulting in a variety of functional groups. While the final molecular weight distributions have very narrow despersities (Đ < 1.10), the efficient successive chain extension polymerization proceeded with high monomer conversions (>99%), delivering excellent block purification in a short period of time. The tetrablock poly(NIPAM-DMA-HEAA-DEA) was characterized by NMR and GPC and showed beneficial end-group fidelity, allowing quantitative monitoring of the system’s alive nature after each synthetic cycle. Importantly, these one-pot syntheses are carried out at a below temperature of 0.0 °C in water as the solvent and can be implemented for applications of molecular biology. We also investigate the potential for a copper-amide complex to develop with acrylamide monomer, which could have an adverse effect on the end group’s functioning. Finally, we believe that this approach makes it easier to create a novel category of advanced polymeric materials.

СВІТОВИЙ ДОСВІД РОЗВИТКУ РИНКУ СОЦІАЛЬНОГО ЖИТЛА: УСПІШНІ ПРАКТИКИ ТА ЗАВДАННЯ ДЛЯ УКРАЇНИ

Among the basic rights is the right to housing, which meets the goals of sustainable development in the areas of poverty alleviation, social protection, and equal rights for everyone. An analysis of existing models of social housing market management has identified three main ones, which differ in terms of the type of beneficiaries they are designed to serve and the purpose. The idea of affordable housing has been spreading in recent years. In this context, social housing should be distinguished from the broader term "affordable housing". The systematization of the features of different models of social housing market management and the tasks of our state allowed us to identify the following criteria for choosing such a model: the goals of the country's social policy (to achieve a certain level of social security, which allows to overcome poverty and ensure minimum sustainable development); the level of stratification of society (the existence of large cohorts of the population that differ significantly in social status, form of employment and need social support dictates the choice of the model of final distribution); the level of material. Amendments to the current legislation in this area that are in line with international standards and need to be implemented are proposed

Costs Analysis for Pathology Clinic Services at “RSK” District Hospital in Central Java Province, Indonesia

The local government-owned hospital, “RSK”, in the northern region of Central Java Province, is expected to propose a new clinical tariff for pathology clinic services urgently. A more accurate calculation method is necessary because the current process of determining hospital service costs lacks a broader cost analysis. This is particularly important for pathology clinics, which are not just a part of the hospital’s services but are essential for diagnosing illnesses and determining the risk and prognosis of diseases. Therefore, this research aimed to form part of the broader cost analysis for “RSK” hospitals. The secondary data collected were investment, operational, and maintenance costs and other relevant input and output data. The cost analysis adopted a modified double distribution or step-down method, which used two distributions of costs. Firstly, an indirect cost was distributed to direct costs, followed by a second distribution to direct costs. Finally, laboratory consumables costs were added to the final distribution results. The analysis results showed that there were 54 types of services, with unit costs (UC) of pathology clinic services ranging from IDR 46.566 (USD 2.95) to IDR 406,220 (USD 25.71). However, hospital management was expected to prepare a new hospital tariff for the local government. Several factors that needed to be considered for new hospital rates included UC, government subsidies, Ina-CBG (Indonesia-Case Based Groups) rates from BPJS, competitive hospital tariff, and the community’s ability to pay.

The chaotic four-body problem in Newtonian gravity – II. An ansatz-based approach to analytical solutions

ABSTRACT In this paper, we continue our analysis of the chaotic four-body problem and our study of binary–binary interactions in star clusters. We present a general ansatz-based analytical treatment using statistical mechanics, where each outcome of the four-body problem is regarded as some variation of the three-body problem. For example, when two single stars are produced (the 2 + 1 + 1 outcome), each ejection event is modelled as its own three-body interaction by assuming that the ejections are well separated in time. This is a generalization of the approach adopted in Paper I, based on the density-of-states formalism. There are three possible outcomes for the four-body problem with negative total energies: 2 + 2, 2 + 1 + 1, and 3 + 1. For each outcome, we apply an ansatz-based approach to deriving analytical distribution functions that describe the properties of the products of chaotic four-body interactions involving point particles. To test our theoretical distributions, we perform a set of scattering simulations in the equal-mass point-particle limit using FEWBODY, where we vary the initial ratio of binary semimajor axes. We compare our final theoretical distributions to the simulations for each particular scenario, finding consistently good agreement between the two. The highlights of our results include that binary–binary scatterings act to systematically destroy binaries producing instead a binary and two ejected stars (when the initial binary semimajor axes are similar) or a stable triple (when the initial semimajor axes are very different). The 2 + 2 outcome produces the widest binaries, and the 2 + 1 + 1 outcome produces the most compact binaries.

Molecular Simulation for Atmospheric Reactions: Non-Equilibrium Dynamics, Roaming, and Glycolaldehyde Formation following Photoinduced Decomposition of syn-Acetaldehyde Oxide.

The decomposition dynamics of vibrationally excited syn-CH3CHOO to form vinoxy + hydroxyl (CH2CHO + OH) radicals or to recombine to form glycolaldehyde (CH2OHCHO) are characterized using statistically significant numbers of molecular dynamics simulations using a full-dimensional neural-network-based potential energy surface at the CASPT2 level of theory. The computed final OH-translational and rotational state distributions agree well with experiments and probe the still unknown O-O bond strength DeOO for which best values from 22 to 25 kcal/mol are found. OH-elimination rates are consistent with experiments and do not vary appreciably with DeOO due to the non-equilibrium nature of the process. In addition to the OH-elimination pathway, OH roaming is observed following O-O scission, which leads to glycolaldehyde formation on the picosecond time scale. Together with recent work involving the methyl-ethyl-substituted Criegee intermediate, we conclude that OH roaming is a general pathway to be included in molecular-level modeling of atmospheric processes. This work demonstrates that atomistic simulations with machine-learned energy functions provide a viable route for exploring the chemistry and reaction dynamics of atmospheric reactions.

Research on Heating Chicken Meat Process in Mechanical and Thermal Operations Using Model Bodies

The research concerns the assessment of mineral materials applicability as a model body for the heating process description of chicken minced meat. A man developes a model body with the same physical structure as chicken meat, similar rheological and thermophysical characteristics. The heating processes of minced chicken and the model body during cutting are identical due to the temperature limit of 12 °C, at which the protein does not undergo changes in the conformational structure and there are no mass transfer processes. The temperature conversion coefficient in the range of 5–12 ° C is 0.94. The authors gained data on the temperature change for the model body converted to minced chicken depending on the mode cutting parameters. The heating processes of the materials under the study during heat treatment differ: the product center from the model body demonstrates a rapid increase in temperature at the initial stage with a gradual decrease in the heating rate in the future; in turn, the minced chicken has a slow growth at the initial stage with a steady heating rate. For the subcortical layer, thermometric curves involve different values with the identical geometry. Different moisture bond nature in the materials causes observed differences. For the surface heating process, the final temperatures for the material sectors under the study are close, the deviation does not exceed 5 %; there are close values of the temperature difference and the limit temperature difference. This is due to the fact that the crust is a dry substance, mass transfer and physico-chemical changes are completed at the initial stage. Thus, the developed model body is applicable for thermal changes studies of minced chicken during mechanical operations at a maximum temperature of 12 °C; is not appropriate for the heating process studies of the inner layers of minced chicken products during heat treatment; and is suitable for the final temperature distribution assessment over the product surface.

Вогнепальна зброя як об’єкт спільної сумісної власності подружжя при розподілі майна

Ukraine is a democratic state governed by the rule of law, that is, one whose legislation should maximally respect the fundamental rights and freedoms of a person and a citizen. In any time, and especially as difficult as now, it is important to have effective functioning of all possible ways to protect and implement these fundamental rights. It is important in our time to observe the right to a fair trial. Yes, many cases are resolved in court, but recently cases about the distribution of property have become widespread. Family law cases involve many important legal issues such as divorce, legal separation, property and debt division, child custody and visitation, child and spousal support, business valuation, health and life insurance, tax implications, parenting and pensions . Problematic issues in cases about the distribution of property of spouses, acquired under the right of common co-ownership during the period of marriage, appear more and more often in modern judicial practice. Thus, a husband and wife who have expressed a desire to dissolve their marriage are not always able to voluntarily agree on the division of property on their own. Therefore, a large number of such cases are resolved in court, and quite often controversial issues arise that are not always regulated by current legislation. An interesting issue is the distribution of weapons acquired during marriage. In many of these situations, you may think that having the gun registered in your name is all that is needed to preserve ownership in a divorce. Unfortunately, this is not the case. Even if each of your firearms is registered in your name alone, this will not affect the final asset distribution decision made by the court. If the weapon was purchased during the marriage, it will be considered joint property regardless of the registration documents. Therefore, a weapon cannot be considered an object of individual use by one of the spouses, and therefore is not personal private property.

Population balance modeling of formation and breakage of nanoparticle agglomerates in a spouted bed

A population balance framework for fluidization of Al2O3 nano-agglomerates in a ProCell-type spouted bed considering agglomeration and breakage phenomena is developed. An equipartition of kinetic energy (EKE kernel) is used to model the agglomeration phenomena. For breakage, two different fragment distribution functions are considered, the Dirac delta function and a function with confined uniform binary breakage. The fractal dimension property is incorporated in both the agglomeration and breakage models. The model parameters are extracted from batch fluidization experiments conducted by varying the air pressure of the top nozzle. The developed model shows a good agreement with experimental observation in regard of the temporal change in the area and volume-weighted average size of nano-agglomerates and of their final size distribution. The developed population balance model is simulated to study the influence of model parameters on the evolution of average size and coefficient of variation of the nano-agglomerates.