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Marine aggregates, composed of various particles, play a crucial role in ocean carbon storage. The overall size distribution of the aggregates (number size spectra) is controlled by the balance between aggregation and disaggregation processes. Turbulence has been proposed to facilitate both aggregation and disaggregation by increasing the collision rate of aggregates or sometimes directly tearing them apart. Predominant processes driven by turbulence typically depend on the level of turbulence—relatively weak turbulence is associated with aggregation while stronger turbulence promotes disaggregation. Aggregate strength also plays a key role, as strongly bonded aggregates can withstand turbulence better, leading to lower disaggregation rates. While the relationship between turbulence and aggregate strength has been studied numerically and experimentally, field measurements remain limited. Here, we compare our number size spectra to turbulence intensity from the field measurements across different environmental settings around Japan to determine the effect of turbulence on aggregate strength. We combined measurements from 10 sites with different environmental settings and observed the flatter slopes (higher net aggregation rate) and shifts in the intersection lengths with an increase of turbulence, while strong turbulence is typically linked with disaggregation. Our findings suggested that stronger aggregates are formed under stronger turbulence and the overall population of strong aggregates also increases with an increase of turbulence intensity. We also compared our number size spectra with three other confounding factors (fluorescence, salinity, and aggregate compositions) to confirm the effects of turbulence are dominant in our aggregate dynamics. [ABSTRACT FROM AUTHOR]

Polymer agglomeration is a useful way to enlarge the particle size of polybutadiene latex (PBL). However, the agglomeration process is very complex and is affected by many factors. Therefore, it is difficult to predict the mean particle size and distribution of agglomerated PBL. This study proposed a novel simulation method based on the artificial neural network (ANN) model. Firstly, the influence of agglomeration conditions on the particle size of agglomerated PBL were investigated, including the particle size of pre‐agglomerate PBL, the amount, the α‐methacrylic acid (α‐MAA) content, the solid content and the particle size of agglomerating agent. It is found that these factors have a close nonlinear relationship with the mean particle size and polydispersion index (PDI) of agglomerated PBL. Then, a model containing 236 data points was built using ANN including these properties as input with mean particle size and PDI of agglomerated PBL as output. The coefficient of determination (R2) values predicted by ANN for training, validation, test and total data are 0.9879, 0.9964, 0.9930, and 0.9902, respectively. It indicates that there is a good agreement between experimental data and predicted results by ANN. This study demonstrates that a simple machine learning method has good performance in predicting the particle size of agglomerated PBL, which further improves the development efficiency of PBL polymer agglomeration. [ABSTRACT FROM AUTHOR]

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The present work studies the use of pistachio shells as a porosity-forming raw material in the manufacture of ceramic bricks. It focuses on the characteristics of the ceramic pieces obtained with different residual biomass contents (from 5 to 20% by volume). The specimens were shaped by uniaxial pressure of 25 MPa, and then were treated at 950°C for 3h. Based on the results obtained it is possible to conclude that the use of this residual biomass, as a pore former in the ceramic industry is feasible. The proportion of added biomass that generates the best characteristics and properties in the final product is 10%. Up to this percentage of aggregate, ceramic pieces with very good macroscopic and microscopic characteristics are obtained, with porosity and flexural strength values that meet market requirements for this type of product. Optical microscopy technique has been used to carry out a detailed analysis of the shape and size of the formed pores, which is a specific objective of this work. It has been observed that for contents of 5 and 10% biomass, the shape of pores is similar to the shape of the particles of added pistachio shells, while for higher contents (15 and 20%) it is different with elongated characteristics. In relation with the size of the pores, at lower contents is around 60% of the original particles size, and for the higher percentages of biomass, they are larger, indicating that agglomerates of particles are formed and when combusted, produce that porosity characteristics. [ABSTRACT FROM AUTHOR]

Coarse-grained (CG) molecular dynamics (MD) can simulate systems inaccessible to fine-grained (FG) MD simulations. A CG simulation decreases the degrees of freedom by mapping atoms from an FG representation into agglomerate CG particles. The FG to CG mapping is not unique. Research into systematic selection of these mappings is challenging due to their combinatorial growth with respect to the number of atoms in a molecule. Here we present a method of reducing the total count of mappings by imposing molecular topology and symmetry constraints. The count reduction is illustrated by considering all mappings for nearly 50 000 molecules. The resulting number of mapping operators is still large, so we introduce a novel hierarchical graphical approach which encodes multiple CG mapping operators. The encoding method is demonstrated for methanol and a 14-mer peptide. With the test cases, we show how the encoding can be used for automated selection of reasonable CG mapping operators. [ABSTRACT FROM AUTHOR]

The scientific objective of the present work is to investigate the variation in the morphological and elemental composition of atmospheric aerosols in a rural-continental environment in Northeast India. We examined particle morphology and elemental composition of Aethalometer (AE-31) filters using an SEM–EDX technique. Sixteen elements, which were categorized as carbonaceous, mineral dust, metals, sea salt, sulfate, and biogenic, have been detected and quantified in the order of C > O > Si > N > S > Fe > Na > K > B > Mg > P > Al > Ca > Cu > Cl > Br. The presence of element C in all the samples with significant contributions is one of the major observations. We examined particle shapes from regular to irregular, including spherical, triangular, capsule-like, agglomerate structures, and platy shapes ranging from 0.1 to 40 µm. We noticed that the effects of meteorology, long-range transport, and local sources result in the presence of different elements in different months. The EDX results showed the presence of a wide variety of particle shapes from natural and anthropogenic origins dominated by carbonaceous particles and aluminosilicates. Based on the EDX results, we have further classified particles into four major groups: anthropogenic, geogenic, marine origin, and biogenic group of aerosols. The major possible sources of aerosols at the study location are vehicular emissions, biomass burning, resuspended road dust, soil, biological emissions, brick kilns, and long-range transport. Planetary boundary layer height and meteorological parameters have been observed to be played a major role in the increase of aerosol during different seasons. [ABSTRACT FROM AUTHOR]

Magnesium hydroxide nanoparticles are widely employed in numerous industrial applications. Several preparation methods have been proposed using mainly synthetic Mg2+ containing solutions. In the present work, the possibility of producing Mg(OH)2 nanoparticles from real bitterns, the by-product of sea salt production, is investigated. Bitterns are highly concentrated Mg2+ containing solutions whose exploitation can turn a waste into valuable products embracing the circular economy idea. Two bitterns collected from Galia and Margi saltworks of the district of Trapani (Italy) were studied. Galia and Margi bitterns had a 1 M and 2.5 M Mg2+ concentration, respectively. A 2 mm diameter circular-cross sectional T-mixer was adopted to ensure fast reactant mixing. NaOH solutions were employed as precipitant agents. Mg(OH)2 nanoparticles characterized by cationic and mass purity higher than 99 % and 90 %, respectively, were successfully produced when treating Galia bitterns, while the excessive Margi Mg2+ concentration yielded stronger micrometer Mg(OH)2 agglomerates. [ABSTRACT FROM AUTHOR]

We introduce methods for large-scale Brownian Dynamics (BD) simulation of many rigid particles of arbitrary shape suspended in a fluctuating fluid. Our method adds Brownian motion to the rigid multiblob method [F. Balboa Usabiaga et al., Commun. Appl. Math. Comput. Sci. 11(2), 217-296 (2016)] at a cost comparable to the cost of deterministic simulations. We demonstrate that we can efficiently generate deterministic and random displacements for many particles using preconditioned Krylov iterative methods, if kernel methods to efficiently compute the action of the Rotne-Prager- Yamakawa (RPY) mobility matrix and its "square" root are available for the given boundary conditions. These kernel operations can be computed with near linear scaling for periodic domains using the positively split Ewald method. Here we study particles partially confined by gravity above a noslip bottom wall using a graphical processing unit implementation of the mobility matrix-vector product, combined with a preconditioned Lanczos iteration for generating Brownian displacements. We address a major challenge in large-scale BD simulations, capturing the stochastic drift term that arises because of the configuration-dependent mobility. Unlike the widely used Fixman midpoint scheme, our methods utilize random finite differences and do not require the solution of resistance problems or the computation of the action of the inverse square root of the RPY mobility matrix. We construct two temporal schemes which are viable for large-scale simulations, an Euler-Maruyama traction scheme and a trapezoidal slip scheme, which minimize the number of mobility problems to be solved per time step while capturing the required stochastic drift terms. We validate and compare these schemes numerically by modeling suspensions of boomerang-shaped particles sedimented near a bottom wall. Using the trapezoidal scheme, we investigate the steady-state active motion in dense suspensions of confined microrollers, whose height above the wall is set by a combination of thermal noise and active flows.We find the existence of two populations of active particles, slower ones closer to the bottom and faster ones above them, and demonstrate that our method provides quantitative accuracy even with relatively coarse resolutions of the particle geometry. [ABSTRACT FROM AUTHOR]

Despite the UV performance benefits of particulate UV filters, concerns have been raised over their potential percutaneous permeation leading to the requirement of a specific approval for all nano UV filters in Europe. Under the legally binding definition of the Cosmetic regulation No. 1223/2009, nanomaterial means a material on the scale from 1 to 100 nm. The recommendation of the European Commission (2011/696/EU) revised 10th of June 2022 (2022/C229/01) further specifies that a material is nano when at least 50% of the number size distribution of the constituent particles is comprised between 1 and 100 nm. The situation for Titanium Dioxide and Zinc Oxide is confusing since the constituent particles are often part of agglomerates. Some suppliers clearly specify the nano feature of their material, while others declare the non-nano property of their inorganic products. The objective of this study was, therefore, to measure the number-based particle size distribution of three marketed Titanium Dioxide and Zinc Oxide grades using the decision support flow scheme devised by the NanoDefine project. This group was created to support the identification of nanomaterials as required by the European legislation. We employed the tier 1 method asymmetrical flow field-flow fractionation (AF4) coupled with UV and IC-PMS (inductively coupled plasma mass spectroscopy) detectors and tier 2 method transmission electron microscopy (TEM). The study clearly taught that the samples that appeared to be non-nanomaterials with AF4-IC-PMS measurements were finally proven to be nanomaterials using the TEM tier 2 method. Relying only on tier 1 methodologies such as AF4, X-Ray Disc Centrifuge or Dynamic Light Scattering to determine the non-nano property of a material is insufficient, since tier 1 methods are not able to detect constituent particles as part of agglomerates, which is often the case for Titanium Dioxide and Zinc Oxide. The status of being a non-nanomaterial can, in this case, only be certified with a tier 2 technique, particularly electron microscopy. [ABSTRACT FROM AUTHOR]

The brewing industry annually produces nearly 200 billion litres, generating more than 15 million tons of malt residue. Most of this residue is used to generate energy for the industries' operation. However, a still significant part, estimated at more than 1.5 million tons, coming mainly from small and medium breweries, does not have a good destination. Given this context, this research aimed to develop a bio compound to replace conventional wood agglomerates made from brewing malt residue with pre-gelatinised corn and PVA glue. Bio compound with brewer's residue was made by following steps: pre-gelatinised corn was initially driven by extrusion in an IMBRA RX50, single screw extruder (INBRAMAQ, Ribeirão Preto, SP). Soon after extrusion, extruded was ground in a hammer mill with a smaller than 0.7 mm particle size. The pre-gelatinised was mixed with the brewer's residue, PVA glue, and water in proportions established in the experimental design and pressed in a hydraulic press at 40 kg/cm². Each sample was dried in an oven with air circulation at 70 °C for 24 hours. After the oven, the material was placed in a desiccator until the analysis. All treatments established in the experimental design were subjected to characterisation analyses: Mechanical resistance by Texture Analyzer TAXT2 Plus (Stable Micro Systems, England), density, moisture by AOAC methods, and Colour by Minolta Chroma Meter CR-400 colourimeter. With the analysis of the results, it was possible to identify that the material formed with the proportion 65:35 (residue / pre-gelatinised corn) plus 10 % of PVA presented better results in terms of mechanical resistance. The analysis of Colour and appearance of the material does not show significant variation in the results, and it was impossible to establish a better treatment for these characteristics. The data presented could conclude that the bio compound developed could be a good destination for this waste since it showed physical characteristics like conventional agglomerates, with the additional advantages of low cost and lower environmental impact due to no use of chemical components in its composition. [ABSTRACT FROM AUTHOR]

Hydrogen and helium co-implantation is nowadays used to efficiently transfer thin Si layers and fabricate silicon on insulator wafers for the microelectronic industry. The synergy between the two implants which is reflected through the dramatic reduction of the total fluence needed to fracture silicon has been reported to be strongly influenced by the implantation order. Contradictory conclusions on the mechanisms involved in the formation and thermal evolution of defects and complexes have been drawn. In this work, we have experimentally studied in detail the characteristics of Si samples co-implanted with He and H, comparing the defects which are formed following each implantation and after annealing. We show that the second implant always ballistically destroys the stable defects and complexes formed after the first implant and that the redistribution of these point defects among new complexes drives the final difference observed in the samples after annealing. When H is implanted first, He precipitates in the form of nano-bubbles and agglomerates within Hrelated platelets and nano-cracks. When He is implanted first, the whole He fluence is ultimately used to pressurize H-related platelets which quickly evolve into micro-cracks and surface blisters. We provide detailed scenarios describing the atomic mechanisms involved during and after coimplantation and annealing which well-explain our results and the reasons for the apparent contradictions reported at the state of the art. [ABSTRACT FROM AUTHOR]

This work proposes a model of particle agglomeration in elastic valves replicating the geometry and the fluid dynamics of a venous valve. The fluid dynamics is simulated with Smooth Particle Hydrodynamics, the elastic leaflets of the valve with the Lattice Spring Model, while agglomeration is modelled with a 4-2 Lennard-Jones potential. All the models are combined together within a single Discrete Multiphysics framework. The results show that particle agglomeration occurs near the leaflets, supporting the hypothesis, proposed in previous experimental work, that clot formation in deep venous thrombosis is driven by the fluid dynamics in the valve. [ABSTRACT FROM AUTHOR]

Food industries must adapt their formulations to consumer needs, for a healthy diet. Extruded snacks are products where 10 to 20 % of fat, and large amounts of salt, are sprinkled on to fix flavours. Considering the need for flavouring and simultaneously reducing fat and sodium on snacks, an alternative flavouring method based on polysaccharides and a different salt delivery method was studied. This work aimed to evaluate waxy starch solutions to replace the oil in snacks, and a different approach to deliver salt, decreasing sodium content while keeping the same salt perception. To change the salt level, agglomerates were made with 70 %, and 85 % salt amounts, 30 % and 15 % starch added, respectively, in three different treatments, T1 (70 % of salt), T2 (85 % of salt), and T3 (100 % of salt, without waxy starch) as a control sample. All samples were milled in the same granulometry as regular salt. The snacks were flavoured using coatings consisting of waxywater solutions. The products were analysed by evaluating: i) physical-chemical parameters (lipids and sodium content, agglomeration index analysis (IA), and colour); ii) instrumental hardness; iii) sensorial parameters with 52 non-trained tasters. The main results showed no significant differences between T1, T2, and control samples in terms of lipids, sensorial perception, colour, and texture. As expected, in the sodium content, 30 % of reduction were found in T1 and 15 % of reduction in T2 compared with control. In this context, snacks produced in the present study would be healthier without a significant saltness perception difference from the controls. [ABSTRACT FROM AUTHOR]

We present the studies of the high-order harmonic generation of 802-nm, 64-fs pulses in the extended plasmas contained the carbon-based clusters (fullerenes, nanofibers, nanoparticles, and nanotubes). Our studies show that the 11th-19th harmonics in the 15-33 eV range may originate from the low-sized nanoparticles produced during ablation of large clusters and agglomerates. The conversion efficiency of the 11th harmonic generated from the 5-mm-long fullerene plasma was estimated to be 2 x 10-5. [ABSTRACT FROM AUTHOR]

Although aerosols in some postaccident nuclear environments can be nonspherical, chainlike, or agglomerates, there have been limited investigations of the rate processes (such as coagulation, evaporation, condensation, and deposition) involving such particles. In a previous investigation, the understandings of condensation and evaporation on such particles were expanded through use of a one-speed approximation for modeling vapor (or fission product) molecular transport, and the present paper extends that work to energy- and mass-dependent transport of vapor molecules within the context of the linear Boltzmann equation via the Monte Carlo particle transport method for rigid sphere molecules. The results are benchmarked against available numerical results and experimental data for a single sphere, and it is found again that the normalized condensation rate has only a weak dependence on the molecular mass ratio (vapor to background) and that the one-speed approximation is quite good. Results are reported for a range of chainlike and agglomerate aerosols. [ABSTRACT FROM AUTHOR]

Reciprocity between cells and their surrounding extracellular matrix is one of the main drivers for cellular function and, in turn, matrix maintenance and remodelling. Unravelling how cells respond to their environment is key in understanding mechanisms of health and disease. In all these examples, matrix anisotropy is an important element, since it can alter the cell shape and fate. In this work, the objective is to develop and exploit easy-to-produce platforms that can be used to study the cellular response to natural proteins assembled into diverse topographical cues. We demonstrate a robust and simple approach to form collagen substrates with different topographies by evaporating droplets of a collagen solution. Upon evaporation of the collagen solution, a stain of collagen is left behind, composed of three regions with a distinct pattern: an isotropic region, a concentric ring pattern, and a radially oriented region. The formation and size of these regions can be controlled by the evaporation rate of the droplet and initial collagen concentration. The patterns form topographical cues inducing a pattern-specific cell (tenocyte) morphology, density, and proliferation. Rapid and cost-effective production of different self-agglomerated collagen topographies and their interfaces enables further study of the cell shape-phenotype relationship in vitro. Substrate topography and in analogy tissue architecture remains a cue that can and will be used to steer and understand cell function in vitro, which in turn can be applied in vivo, e.g. in optimizing tissue engineering applications. [ABSTRACT FROM AUTHOR]

The pelletizing process agglomerates ore fines previously considered as tailings and makes its application possible in the form of pellets. During the process, the pellets are subjected to various compressive forces and temperature changes, which cause ruptures in their surface. These ruptures (cracks) impair the performance of the pellets in the reduction furnaces and affect their strength. In addition to cracking, the formation of clusters inside the furnaces is also a problem for the reduction process because they compromise the flow of gases inside the furnaces. This bonding phenomenon occurs from the formation of iron bridges between pellets subjected to high temperatures. This problem can be minimized by coating the pellets with a mixture of magnesium oxides that inhibits bridging. The present study considered the importance of characterizing cracks and coating on the pellet surface and developed methodologies for the acquisition, processing and digital analysis of images acquired with a stereoscope. Adjustable sample holders were developed which made it possible to cover most of the surface area of the spherical object avoiding overlapping of analysis regions. The crack analysis routine used semantic segmentation and provided attributes such as mean thickness, area fraction and length. The coating analysis routine used color threshold segmentation and measured the fraction of the area occupied by the coating in the samples. The use of the sample holders was essential for the success of the acquisition procedure. The analysis routines were robust for different samples. [ABSTRACT FROM AUTHOR]

Spitting behaviour of four casted and powder metallurgy ingots used in the fabrication of NiCoCrAlY-type environmental protective coatings by electron beam physical vapour deposition was investigated and correlated with ingot microstructures and compositions. Spits found in the coatings mainly consisted of the Ni5Y phase precipitated in the β-NiAl matrix while their typical size exceeded 50 µm. Spitting was less pronounced for ingots having a higher Cr content, larger size of γ-Ni(Co, Cr) precipitates formed within β-NiAl grains and narrower transitional zone formed at the interface between molten and unmolten ingot regions and consisting of coarsened β grains. Large (above 100 µm) agglomerates of the Ni5Y phase detected below the zone were identified as the main spit precursors. [ABSTRACT FROM AUTHOR]

Studies of biological systems typically require the application of several complementary methods able to yield statistically-relevant results at a unique level of sensitivity. Combined X-ray fluorescence and ptychography offer excellent elemental and structural imaging contrasts at the nanoscale. They enable a robust correlation of elemental distributions with respect to the cellular morphology. Here we extend the applicability of the two modalities to higher X-ray excitation energies, permitting iron mapping. Using a long-range scanning setup, we applied the method to two vital biomedical cases. We quantified the iron distributions in a population of macrophages treated with Mycobacterium-tuberculosis-targeting iron-oxide nanocontainers. Our work allowed to visualize the internalization of the nanocontainer agglomerates in the cytosol. From the iron areal mass maps, we obtained a distribution of antibiotic load per agglomerate and an average areal concentration of nanocontainers in the agglomerates. In the second application we mapped the calcium content in a human bone matrix in close proximity to osteocyte lacunae (perilacunar matrix). A concurrently acquired ptychographic image was used to remove the mass-thickness effect from the raw calcium map. The resulting ptychography-enhanced calcium distribution allowed then to observe a locally lower degree of mineralization of the perilacunar matrix. [ABSTRACT FROM AUTHOR]

We have made observations of noble metal phase fission-product agglomerates and gaseous xenon within the fuel-cladding interaction (FCI) zone of a high-burnup UO2 fuel. The FCI is the boundary between the UO2 pellet outer surface and the inner wall of the oxidized Zr-liner/cladding of the fuel rod. These fission-product agglomerates are well known to occur within the spent fuel matrix, and although radionuclides have been reported by others, we reveal aspects of their speciation and morphology. That they occur as discrete particles in the oxidized Zr liner, suggests the occurrence of hitherto unknown processes in the FCI zone during reactor operation, and this may have implications for the long-term storage and disposal of these types of materials. As expected, the particle agglomerates, which ranged in size from the nanometer scale to the micrometer scale, contained mainly Mo, Ru, Tc, Rh, and Pd; however, we also found significant quantities of Te associated with Pd. Indeed, we found nanometer scale separation of the distinct Pd/Te phase from the other fission products within the particles. Often associated with the particles was concentrations of uranium, sometimes appearing as a "cloud" with a tail emanating from the fuel into the oxidized cladding liner. Many of the noble metal phase particles appeared as fractured clusters separated by Xe-gas-filled voids. Possible mechanisms of formation or transport in the cladding liner are presented. [ABSTRACT FROM AUTHOR]

Small particles like pellets are coated in fluid bed systems. This method can be also feasible for minitablets but the selection of optimal process parameters is complicated. The aim of the research was to optimize the coating process for minitablets and to compare the conditions required for pellets. Minimum fluidization velocities (umf) for 2.0 and 2.5 mm minitablets and 0.7-0.8 mm or 1.0-1.25 mm pellets were determined experimentally. Additionally, the results were verified using the Ergun equation. The smallest relative differences between the calculated and experimental values of umf were obtained for P0.7 (4.6%), while the largest for MT2.5 (11.8%). To simplify optimization of the coating process, Design of Experiment (DoE) based on the Taguchi method was employed. Selection of the best process parameters was based on the film thickness measurements for minitablets, while the sieve analysis was used for pellets to detect agglomeration. The best combination of process parameters resulted in uniform film thickness in minitablets, with RSD less than 15%, and the pellets batch containing only 0.25% of bonded particles. It was found that the largest impact on the uniform film deposition on minitablets had a spraying pressure, responsible for the size of coating mixture droplets. In the case of pellets, the most critical was the inlet air temperature. The presented research demonstrated that it was possible to achieve the best parameters of the coating process for minitablets and pellets by combining calculations of minimum fluidization velocity and Design of Experiment based on the Taguchi method. [ABSTRACT FROM AUTHOR]

Nanoparticles often form agglomerates during their manufacturing process. When nanoparticles form agglomerates, their inherent properties cannot be fully exploited. In this study, we attempted to establish a conventional method to evaluate the fracture strength of agglomerates into smaller parts. We used a commercially available nano-indentation instrument with a flat indenter tip. We chose calcium carbonate nanoparticles with stearic acid coatings as model materials. It was found that the more fatty acid that is coated on the particle surface, the stronger the agglomerates become. The technique we propose in this study can be used to rapidly evaluate the fracture strength of nanoparticle agglomerates. [ABSTRACT FROM AUTHOR]

Highlights • Bed agglomeration and ash deposition during CFB combustion investigated. • Bottom ash was agglomerated due to the abundance of Fe and Na. • Deposit showed a layered structure and was sintered by micron-sized Ca, S and Na. • Fly ash was composed of Ca-, and S-rich clusters and micron Ca/Si/Al particulates. • The transformation of Ca, Na, and Fe, and their role in ash deposition analysed. Abstract The characteristics and mechanisms of inorganics and mineral transformation, particle agglomeration and ash deposition during Zhundong lignite combustion in a 0.2 t/d lab-scale circulating fluidized bed (CFB) furnace were experimentally investigated. A sample of Zhundong lignite with particle size <3 mm was combusted in the CFB operating at 950 °C. An ash deposition probe installed at the upper outlet of the cyclone maintained at 550 °C was used to simulate ash deposition. The bottom ash, ash deposit on the probe, and fly ash were collected and analysed using SEM-EDX, XRD, ICP-OES and an ash fusion analyser. It was found that the bottom ash was composed of discrete particles of SiO 2 , Fe 2 O 3 , and NaAlSiO 4 and etc., among which particles rich in Fe and Na had agglomerated. The deposit on the upwind surface of the probe showed a layered structure: a sintered cone-shape inner-layer rich in micron-sized Ca- and Na-bearing minerals, and a loose coarse-grained outer-layer dominated by silicates and aluminosilicates. The inner-layer was believed to have initiated the ash deposition while the outer-layer was believed to have been captured by the initiating layer. XRD analysis confirmed the presence of Ca- and Na-bearing minerals including CaSO 4 , NaAlSiO 4 , Na 2 SO 4 and Na 2 Si 2 O 5 of low melting-points in the deposit. The fly ash was composed of ash particles or clusters enriched in CaSO 4 and Ca 2 Al 2 SiO 7. Furthermore, ICP analysis revealed that Na was enriched in the deposit, while Fe was enriched in the bottom ash, both of which however were comparably less in the fly ash. Consequently, the fusion temperatures of the bottom ash and deposit were lower than that of the fly ash. In addition, mineral interactions between bed materials and Zhundong lignite ashes including Na capture by aluminosilicate were identified, affecting the partitioning of alkali and alkali earth during combustion and ash deposition in CFB. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Agglomerate disintegration mechanism in a non-uniform electric field was studied. • The electric field was formed between an upper wire mesh and a lower metal plate. • Charged straight-chain agglomerates were formed on surface of particle layers. • Agglomerates levitated and disintegrated with rotation near the upper electrode. • Torque based on charge distribution in an agglomerate caused the disintegration. Abstract The mechanism of disintegration of agglomerates in a non-uniform electric field was studied experimentally and numerically. An external electric field was formed between an upper electrode made of wire mesh and a lower electrode comprising a metal plate. The dielectric particle layers on the lower electrode were charged by induction, and straight-chain agglomerates were formed on the surface of the particle layers by dipole interactions between the particles based on dielectric polarization. In the electric field, the charged agglomerates levitated under the influence of the Coulomb forces, and the charged agglomerates disintegrated with rotation when approaching the upper electrode. The experimental study and analysis of the numerical motion of the agglomerate showed that the charge distribution in the agglomerate generates torques around the centroid of the agglomerate in the non-uniform electric field around the upper electrode, and the centrifugal force acting on the rotating particles causes disintegration of the agglomerates. [ABSTRACT FROM AUTHOR]

Abstract In this work, the strength of tablets made from mixtures of whey protein concentrate (WPC) powder and different types of sugar was investigated. The agglomerated WPC powder was pneumatically conveyed (lean phase) at three different air speeds of 10, 20 or 30 m/s to simulate the effects of industrial powder transport, resulting in agglomerates with reduced integrity. Conveyed and control WPC powder, and sugar of three different particle size distributions (i.e., granulated, GS; caster, CS and icing sugar, IS) were analysed for microstructure, particle size, moisture, and flowability. Tensile strength of tablets from WPC powder alone or blended with 0.5–10% sugar was tested. Conveying of WPC powder led to a significant increase in tablet strength, (i.e., from failure strength of 1.67 N/mm2 for control tablets to 2.33, 2.11 and 2.11 N/mm2 after conveying at 10, 20 or 30 m/s, respectively), suggesting that the generation of smaller powder particles led to increased mechanical strength of tablets. The addition of sugar also resulted in a significant increase in tablet strength (e.g., failure strength of 2.34, 2.12 and 2.47 N/mm2 at 1.5% addition level of GS, CS and IS, respectively) and strongest tablets were obtained at 1.5–3% sugar addition and by blending with icing sugar. This study demonstrated, for the first time, that conveying and dry blending of whey protein and sugar powders significantly influenced the rheological properties of resultant tablets. Highlights •Lean phase conveying reduced mechanical integrity of powder agglomerates. •Bulk flow behavior was enhanced post lean phase conveying. •Tablets prepared using conveyed powders had higher fracture load. •Incorporation of sugar in blends with whey powder resulted in stronger tablets. •Brazilian disc test can detect variations in tablet composition as little as 0.5%. [ABSTRACT FROM AUTHOR]

Sedimentation of opaque suspensions of carbon black and lithium-iron-phosphate was investigated by spin-echo-based magnetic resonance imaging. Optical methods are usually applied to determine settling velocities, but are limited with respect to high concentrations and optical transparency. The presented method uses intensity data from the noninvasively measured magnetic resonance signal of the sample. The settling velocity is obtained from the evolution of the signal intensity profiles based on the contrast in 1H magnetic resonance imaging between particles and liquid. New insights into the sedimentation in opaque suspensions are provided, since the 1H images uncover the spatial distribution of the particles and its agglomerates, as well as the shape of the settling front. Additionally, the sedimentation was experimentally studied using a sedimentation balance, which gravimetrically measures the increase in mass fraction over time due to the settling of particles. By parallel usage of these two methods, the sedimentation processes of opaque suspensions of lithium-ion-battery electrode materials were investigated. The sedimentation balance covers high, technically relevant concentrations. Limiting factors of the methods are discussed, which are mainly signal intensity in the magnetic resonance imaging and the increasing viscosity of highly concentrated suspensions. [ABSTRACT FROM AUTHOR]

Abstract Influence of colloidal silica sol (SS) consisting of mono-dispersed nano-silica on properties and microstructure of the hardened cement-based materials was investigated as compared to the nano-silica (NS) powder with agglomerates in micron-scale through detecting the mechanical and durable properties of the hardened mortar and by using SEM observation, nano-indentation test and MIP analysis. The results showed that the strength enhancement of the mortar with SS addition revealed an overall more improvement but a higher discreteness than that with NS addition. After the calcium leaching test, it was found that the strength of the mortar with SS addition showed a clearly higher loss than that with NS addition, though the neutralization depth revealed a more reduction while incorporating SS and the residue strength still tends to increase with increasing the nano-silica addition. All these observations are resulted from the fact that the nano-particles in SS coagulate immediately once cement is mixed into water containing SS, forming loose flocs with a more open microstructure and a higher free water retention capacity than the agglomerates in NS, thus leading to a lower free water cement ratio in fresh cement paste and an overall more compact microstructure in hardened cement paste while incorporating SS. However, pozzolanic C-S-H gels from the gelled nanosilica can be observed to show a loose compaction, with nanopores and even micropores inside and also an abnormal growth of the larger CH crystals in the pozzolanic C-S-H gels but without nucleated growth of the C-S-H gels from cement hydration. The dissolution of the larger CH crystals in the coagulated gel network in the paste may leave large pores in the hardened cement mortar to cause a higher strength loss after the calcium leaching test. The MIP testing results indicated that the threshold pore size showed few differences for the HCP with and without 1.0% nano-silica addition, illustrating the permeability of the hardened cement paste may have nothing to do with the threshold pore size, but the total porosity and the micropores in the range of 100–10000 nm. [ABSTRACT FROM AUTHOR]

Herein, the advantage of single-shell hollow microspheres on forming pores has been exploited to acquire porous ceramics with homogeneous microstructure, while the hollow microspheres also acted as reaction source. Dispersant reaction method has been applied to realize the perfect combination between microspheres and Si3N4 particles, which could be attributed to the repulsion between particles is weakened, particles agglomerate together and holding microspheres among them tightly. Owing to the normal distribution of hollow spheres and their single-shell structure, porous Si2N2O-Si3N4 ceramics with uniform pore distribution have been fabricated. The results show that the addition of silica hollow spheres contributes to the decrease in dielectric constant, since their porosity could be increased effectively and Si2N2O phase exhibiting low dielectric constant is generated. High-performance porous Si3N4 ceramics with porosity of 45.7% have been prepared through employing fly ash hollow microspheres, which possess flexural strength of 108.76 ± 6.25 MPa, fracture toughness of 1.78 ± 0.09 MPa m1/2 and dielectric constant of 3.53. This strategy is proved to be a convenient, eco-friendly and effective method to synthesize ideal candidates for radomes. [ABSTRACT FROM AUTHOR]

Abstract The present study is a systematic investigation into the effect of three different types of surfactants (anionic: SDBS, cationic: CTAB, and non-ionic: PVP) on the behaviour of electroless Ni-P baths containing TiC nanoparticles, and on the formation of Ni-P-TiC composite coatings. The effect of surfactants can be observed in the interfacial phenomena, i.e. wetting and electrokinetic behaviour during the formation of the coating. The wetting properties of the coating bath were investigated by the sessile drop method, which revealed the wetting improvement on all three substrates (W302 steel, TiC, Ni-P coating substrates) in the case of the anionic and cationic surfactant. The Zeta potential measurement showed a stability decrease in Ni-P bath compared to the distilled water medium, which led to the agglomeration of the TiC particles. TiC agglomerate size below 100 nm was achieved by all three types of surfactant (1 g/L) in distilled water; however, only larger agglomerates were measured in the Ni-P bath. Finally, the Ni-P-TiC composite coatings on steel substrate were created. The investigation of the cross-section of the coatings revealed that, the highest amount of TiC (0.53 wt.% and 0.52 wt.%) was incorporated in the Ni-P matrix with the use of 0.1 g/L CTAB and 0.1 g/L PVP respectively, although these particles formed larger agglomerates. Highlights • Ni-P bath characteristics are investigated using three types of surfactants. • Wetting properties of Ni-P baths on TiC, W302 steel and Ni-P coating are determined. • Zeta potential and particle size of Ni-P-TiC dispersions are measured. • Ni-P-TiC composite coatings were successfully created. • The amount of TiC incorporated into the coating is determined for each surfactant. [ABSTRACT FROM AUTHOR]

Abstract Reactive synthesis of Ti 5 P 3.16 crystals was firstly investigated in the Al–Ti–P–C alloy and their effective refinement on primary Si in Al–Si alloys was also revealed. It was found that the Ti 5 P 3.16 phase was formed by the direct reaction of P atoms with TiC particles in Al melt. During the reaction process, P atoms absorbed on TiC agglomerates and initiated the gradual phase decomposition, and then the releasing Ti atoms combined surrounding P ones together to form Ti-P phase. Based on the TEM and SEM characterization, it is identified that the Ti 5 P 3.16 phase has an hexagonal close packed crystal lattice structure and mainly displays a regular hexagonal prism morphology enclosed by six {10-10} facets and two parallel {0001} ones. Furthermore, the Al–Ti–P–C alloy containing the Ti 5 P 3.16 particles showed an efficient refinement performance on primary Si particles for hypereutectic Al–Si alloy, whose average size was reduced from 85 μm to 12.5 μm for A390 alloy. In order to reveal the refinement mechanism, the evolution process of the Ti 5 P 3.16 phase induced by Si atoms in the Al–Si melt was carried out, indicating that the Ti 5 P 3.16 transformed into amounts of nano AlP particles with sizes of about 100–200 nm after added into the melt. Then, these in-situ AlP particles with fresh interfaces distributed uniformly in the melt and act as the effective heterogenous nuclei for the primary Si during the following solidification process of Al–Si melt with the decrease of the melt temperature, which leads to significantly refinement of the microstructure of A390 alloys. Highlights • Ti 5 P 3.16 phase was firstly synthesized in the Al alloy. • Ti 5 P 3.16 crystals showed the regular hexagonal prism morphology. • Ti 5 P 3.16 particles can significantly refine the primary Si grains in for A390 alloy. • Phase transition of Ti 5 P 3.16 induced by Si was revealed. • The in-situ formed nano and sub-micro AlP particles are efficient nucleating sites for primary Si during solidification. [ABSTRACT FROM AUTHOR]

In order to improve the static response of thick hollow cylinders, a sandwich cylinder with two carbon nanotube (CNT)‐reinforced nanocomposite face sheets are proposed in this article. Moreover, due to the use of optimum amount of high cost CNTs, the CNT distribution is suggested to be functionally graded (FG) along the thickness of cylinder. The stress and deflection profiles of the proposed sandwich cylinders subjected to internal and external pressures have been investigated using a finite element method (FEM) based on an axisymmetric model. The significant effect of formation of CNT agglomerations in the surrounded matrix is considered and the material properties of the resulted nanocomposite are estimated by Eshelby‐Mori‐Tanaka approach. Using the developed axisymmetric FEM model, the effects of CNT aggregation state, volume fraction, and distribution as well as geometrical dimension and loading condition on the stress and deflection distributions of the nanocomposite sandwich cylinders have been characterized. The extensive simulations have revealed that instead of adding higher volume fraction of CNT, the selection of suitable distribution for CNTs can lead to a nanocomposite sandwich cylinder with less deflection. POLYM. COMPOS., 40:E1918–E1927, 2019. © 2019 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract The elemental profiling of sixteen coffee samples collected from eight major coffee producing Yemeni governorates was determined. Analyses were performed using inductively coupled plasma (ICP)-optical emission spectroscopy (OES). Among macro elements, K showed the highest levels. Ca was also present in high quantity in Yemeni coffee. This elevated content is in sharp contrast with coffees from Ethiopia and thus Ca-content can be used to differentiate Yemeni and Ethiopian coffees, the two most highly rated coffees on a commercial standpoint. Results were confirmed by chemometric (principal component and hierarchical agglomerative clustering) analyses. Highlights • 24 elements were quantified in 16 Yemeni coffee samples. • No toxic elements were detected. • Yemeni and Ethiopian coffees are in competion on the high prized coffee. • Macro element content can be used to discriminate Yemeni against Ethiopian coffee. • The geographic origin of Yemeni coffee can be certified by macroelement determination. [ABSTRACT FROM AUTHOR]

In this paper we present a coarse-graining (CG) approach for the agglomeration of nano-particles and clusters. In the current context, coarse-graining involves the replacement of fractal-like clusters by "representative" spherical particles. This simplification reduces significantly the number of degrees of freedom and allows for the computation of much larger systems and for better collision statistics of larger clusters. However, detailed information on the cluster shape is lost, but it is exactly this detailed shape that determines collision frequencies between fractal clusters and thus the agglomerates' growth. Therefore, additional properties need to be "inherited" by the coarsegrained particle that ensure similar collision frequencies. We generate collision probabilities as functions of the minimum passing distance between the clusters and provide these as additional function to the CG particle. This allows for partial overlap between CG particles, and the collision/sticking event is triggered with a specific probability only. We compare collision frequencies of CG simulations with equivalent Langevin dynamics simulations where all primary particles are tracked, and we observe decent agreement between cluster growth predicted by CG and the detailed Langevin dynamics simulations. Remaining differences may stem from differences in cluster transport. [ABSTRACT FROM AUTHOR]

Mg-Zn nanocrystalline ferrites (Mg1−xZnxFe2O4, where x = 0.0 to 1.0) were synthesized by the citrate gel auto-combustion route. XRD revealed the formation of nano-sized particles with cubic spinel structure. Lattice constant and specific surface area increased with Zn substitution. SEM micrographs revealed inhomogeneous grains with agglomerates; EDS spectra confirmed the stoichiometry. HRTEM images showed agglomerated nanoparticles with average particle sizes of 21 nm and 16 nm for x = 0.6 and 1.0, respectively, and lattice fringe images and SAED patterns showed nanocrystalline characteristics corroborating the XRD results. FTIR and Raman spectra recorded at room temperature confirmed the spinel structure of ferrites. VSM technique at room temperature used to measure magnetic properties. MS and HC were found to decrease with increases in the Zn concentration in Mg-Zn ferrites due to a weakening of the A-B interaction and decrease in the particle size and surface effect. Low-temperature magnetic studies were carried out in the ZFC and FC modes using SQUIDS by applying 100 Oe between temperatures of 5 and 400 K, and magnetic isotherms were recorded at temperatures of 51 and 310 K. The study revealed the superparamagnetic nature of the synthesized samples showing that the blocking temperature (TB) depends on interparticle interactions. [ABSTRACT FROM AUTHOR]

This work describes how a solid-state blending method such as jet milling can be used to successfully prepare polysulfone (PSU)/γ-alumina nanocomposites. For comparison purposes, conventional melt extrusion was used as well. Morphological analysis revealed how jet mill blending allows obtaining well-dispersed γ-alumina nanoparticles within a polysulfone matrix without any surface treatment, with an important decrease of particle size promoted by the breakup of agglomerates and aggregates due to the particle-particle impacts during processing, which was not observed in the extruded nanocomposites. DSC analysis demonstrated that jet-milling processing promoted Tg enhancements with alumina addition, while TGA experiments confirmed the increment of thermal stability of the nanocomposites prepared by jet milling when compared with the composites prepared by extrusion. The tensile tests showed that ductility remains at a high value for milled nanocomposites, which agreed with the fracture surface images revealing large plastic deformation as a function of the alumina content. This comparative study indicates that the dispersion of nanoparticles in PSU was more homogeneous, with smaller nanoparticles when preparing nanocomposites using jet milling, showing a strong correlation with the enhanced final properties of the nanocomposites. [ABSTRACT FROM AUTHOR]

Highlights • Mechanistic CFD model was developed to describe wet agglomerate breakage. • Eulerian simulations were performed and results compared with experimental data. • The effect of gas velocity and liquid viscosity on breakage was reasonably captured. • The model can be used for the study of wet agglomerate breakage in fluidized beds. Abstract A mathematical model that describes wet agglomerate breakage in a gas-solid fluidized bed was developed, utilizing the energy approach to assess agglomerate stability and the Kinetic Theory of Granular Flows (KTGF) to describe collisions between bed primary particles and agglomerates. Wet agglomerates are held together by liquid bridges that resist breakage due to capillary and viscous forces. The probability of breakage depends on the balance between the collisional energy and the energy required to break the necessary number of liquid bridges. The model considers two types of breakage: abrasion, characterized by individual primary particles being stripped from an agglomerate, and fragmentation, where an agglomerate breaks into two pieces, each containing multiple primary particles. Simulations were performed using the Eulerian-Eulerian method with either a monodispersed or a polydispersed approach to describe the size distribution of agglomerates during breakage. Comparison with available experimental data revealed good qualitative agreement between the predicted and measured abrasion and fragmentation rates, with some quantitative discrepancies that can be attributed to model limitations and experimental uncertainties. The effects of superficial gas velocity and liquid viscosity on agglomerate breakage are investigated in detail. The model can serve as a valuable tool to study breakage of wet agglomerates, and it can be extended to include agglomerate formation for a more comprehensive description of hydrodynamics of wet fluidized beds. [ABSTRACT FROM AUTHOR]

Abstract Powder build-up formation is a fouling process in which a small fraction of a powder becomes a coherent, non-porous, film adhered to a surface known as build-up. Build-up tends to form in auger fillers where particles undergo plastic deformation, leading to the formation of build-up on the internal surface of the tube within which the auger is housed. To develop an understanding regarding the process by which build-up is formed, a combination of macro scale auger filling experiments and laboratory scale characterisation of the virgin powder has been undertaken. This involved a comparison of results obtained via uniaxial compaction followed by tablet diametric compressions, with the results of macro scale auger filler experiments. From this work, it has been determined that the build-up forming powders have Kawakita b−1 parameters of 0.5 MPa or less, and form disc-shaped tablets with strengths <0.5 MPa following compaction to 58 MPa. Graphical abstract Unlabelled Image Highlights • Powders of low Kawakita b−1 parameter and tablet strength formed build-up • For build-up forming powders, b−1 is related to plastic yield stress. • Soft plastic materials compact to form soft plastic tablets. [ABSTRACT FROM AUTHOR]

The discrete element method (DEM) was used to study the behavior of crushable angular gravel in the cyclic soil-structure interface test. Two shapes of agglomerates were simulated by filling two scanned angular gravels with spheres connected by bonds that were given the shear and normal strength complying with Gaussian distribution to simulate random flaws. The proportion of these two shapes to constitute a numerical sample was named composite pattern. Good agreement in terms of macromechanical behavior between DEM simulation and laboratory test results has been attained. Agglomerate breakage is deeply influenced by the interface shearing behavior and mainly occurs on the interface and the space nearby. Graphs of interface after shearing are introduced to directly and clearly reflect microbehavior of breakage. The evolution of microstructure including anisotropies and coordination numbers is significantly influenced by normal stress and agglomerate breakage, and composite pattern determines the magnitudes of shear force anisotropy and coordination numbers. The evolution of contact orientation distribution is the forming cause of the "adjustment phase," during which once the shearing direction changes, the values of contact normal anisotropy and normal force anisotropy will slump to their nadir and then rise back again. [ABSTRACT FROM AUTHOR]

Abstract Breakage is important in several operations in food industry as well as in quality control of brittle products. Recently, the breakage pattern of maltodextrin agglomerates (a food model) has been described by our research group by using multifractal parameters; however, this behaviour has not elucidated and explained completely such pattern from the onset of breaking to the edge of the breakage profile. Therefore, the aim of this work was to analyse the geometry and symmetry of 10 sections of the breakage pattern of maltodextrin agglomerates by means of digital image analysis (DIA) and fractal analysis. Results showed significant differences in monofractal dimension (MFD) values at 30% and 90% of the breakage pattern length, indicating that two important morphometric changes occurred along the breakage pattern: one section characterised by a MFD value of 1.1 (more irregular morphology) and other section with a MFD value of 0.8 (less irregular morphology). To validate and verify the experimental MFD values, Monte Carlo derived models were fitted to experimental data, obtaining predicted MFD values in agreement to those obtained by DIA. Predicted MDF values were mostly affected (more sensitive) by the inputs to the linear equation as compared to those of a sixth-order equation. Therefore, the onset of the breakage pattern had a different morphology in comparison to the edge of the profile. Also, no significant differences in lacunarity values were observed along the two (according to MFD values) sections of the breakage pattern. This study helps to explaining the multifractal nature of the breakage pattern and provides valuable information towards the understanding of the complex phenomenon of breakage and its onset. Graphical abstract Unlabelled Image Highlights • Onset's morphology of the breakage pattern was analysed by digital image analysis. • Two important morphometric changes occurred along the breakage pattern. • The onset of the breakage pattern was more irregular than the edge. [ABSTRACT FROM AUTHOR]

Abstract Agglomerates are often composed of amorphous and irregular primary particles, especially in the food industry. The spatial morphology of this kind of soft agglomerate, here maltodextrin, can be quantified by fractal dimension. Previous research in this regard was focused on simulated agglomerates or studied 2D projected images of real agglomerates. In this work 3D volume images of agglomerates are generated with the help of X-ray computed tomography. Primary particles are distinguished and separated by means of a sequence of image processing steps. Thus center coordinates and volume of each particle are extracted. Based on this information, the radius of gyration is calculated and compared for either monodisperse or polydisperse primary particles. The primary particles comprising the maltodextrin agglomerates follow a broad size distribution, hence considering the polydispersity is highly recommended. Next, radii of primary particles are determined in order to calculate 3D fractal dimension and prefactor from power law equation. Due to the irregular shape of primary particles, two different ways of calculating primary particle radius are investigated. It is observed that differences in primary particle radius affect the partial overlapping of particles which mostly influences the prefactor value, while only slight changes are noticed in the fractal dimension. Further, the gyration radius and fractal dimension are obtained directly from voxel data. Though voxel based method is more accurate, it requires more effort and time. Therefore, by considering some error in the values of fractal dimension and gyration radius, the separated polydisperse primary particle model is suggested as a proper option. Finally, fractal dimension is also calculated by the box counting method. The proper implementation of this method for 3D structures is discussed and the results are compared with the classical power law function. Graphical abstract Unlabelled Image Highlights • Radius of gyration and fractal dimension of agglomerates are determined from 3D μ-CT images. • 3D characterization of agglomerates is carried out based on separated primary particles and voxel data. • Effect of polydispersity of primary particle on the radius of gyration is investigated. • Fractal and prefactor dimension of agglomerates with irregular structure are deduced from scaling law. • Box counting method is implemented to calculate 3D fractal dimension of agglomerates. [ABSTRACT FROM AUTHOR]

The crystallization behavior of Shengli waxy crude oil from the sol state to gel state was studied by the microscopic observation and DSC curve. The study shows that as the cooling rate decreases, the number of wax grains becomes smaller, the area is larger and the morphology of wax crystals is more irregular. Moreover, under different cooling rates, wax crystals were homogeneous transient nucleation, but the growth mode of wax crystals was different. When the cooling rate is between 1-4 °C/min, Crystallization Peak 1 wax crystal grows according to the mixed crystal mode of one-dimensional rod crystal and two-dimensional discoid crystal; When the cooling rate is between 6-8 °C/min, Crystallization Peak 1 wax crystal grows according to the mixed crystal mode of two dimensional discoid crystal and three-dimensional spherical crystal; Crystallization Peak 2 wax crystal grows according to the mixed crystal mode of two dimensional discoid crystal and three-dimensional spherical crystal at different cooling rates. Crystallization activation energy of crystallization Peak 1 and Peak 2 are 556.91 kJ/mol and 299.62 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

The neighbor-joining algorithm for phylogenetic inference (NJ) has been seen to have three specific properties when applied to distance matrices that contain an admixed taxon: (1) antecedence of clustering, in which the admixed taxon agglomerates with one of its source taxa before the two source taxa agglomerate with each other; (2) intermediacy of distances, in which the distance on an inferred NJ tree between an admixed taxon and either of its source taxa is smaller than the distance between the two source taxa; and (3) intermediacy of path lengths, in which the number of edges separating the admixed taxon and either of its source taxa is less than or equal to the number of edges between the source taxa. We examine the behavior of neighbor-joining on distance matrices containing an admixed group, investigating the occurrence of antecedence of clustering, intermediacy of distances, and intermediacy of path lengths. We first mathematically predict the frequency with which the properties are satisfied for a labeled unrooted binary tree selected uniformly at random in the absence of admixture. We then introduce a taxon constructed by a linear admixture of distances from two source taxa, examining three admixture scenarios by simulation: a model in which distance matrices are chosen at random, a model in which an admixed taxon is added to a set of taxa that reflect treelike evolution, and a model that introduces a perturbation of the treelike scenario. In contrast to previous conjectures, we observe that the three properties are sometimes violated by distance matrices that include an admixed taxon. However, we also find that they are satisfied more often than is expected by chance when the distance matrix contains an admixed taxon, especially when evolution among the non-admixed taxa is treelike. The results contribute to a deeper understanding of the nature of evolutionary trees constructed from data that do not necessarily reflect a treelike evolutionary process. [ABSTRACT FROM AUTHOR]

Abstract Agglomerates in 3 mol% yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP) powders introduce detrimental heterogeneities that drastically degrade the mechanical properties of the sintered zirconia. This study aimed to investigate the effectiveness of optimized colloidal processing combined with cold isostatic pressing (CIP) in the production of high-density 3Y-TZP with enhanced microstructural and mechanical properties. First, 3Y-TZP suspensions were prepared through colloidal processing with polyethyleneimine (PEI) as a dispersant. After the addition of PEI, the pH of the suspension was adjusted to optimize colloidal stability, which was ascertained through zeta potential measurements. 3Y-TZP green bodies were consolidated through slip casting and allocated into two groups. One group was subjected to CIP, and the other was not. The density, phase structure, microstructure, hardness, and flexural strength of the as-sintered 3Y-TZP samples were then examined. The sample with the highest colloidal stability was obtained with the suspension pH of 2 and PEI addition of 0.4 wt%. The as-sintered 3Y-TZP structures produced without CIP provided a relative density of 93% with an undesired monoclinic phase content of 2.1%. By contrast, 3Y-TZP structures subjected to CIP exhibited a tetragonal phase content of 100% and better mechanical properties, higher density, and more homogeneous microstructures than structures that were not subjected to CIP. Given these results, the optimized colloidal process combined with CIP can be used to successfully produce highly dense and homogenous 3Y-TZP structures with enhanced mechanical properties. [ABSTRACT FROM AUTHOR]

Dry powders embedded with gold nanoparticles (AuNPs) are produced by spray‐drying technique from an aqueous AuNP dispersion in a poly(vinyl alcohol) (PVA) or poly(vinyl pyrrolidone) (PVP) matrix. The prepared powders consist of AuNPs stabilized in hollow capsules of PVA (PVA@AuNP) or PVP (PVP@AuNP) with an average diameter of several micrometers. The AuNP powders are dispersible in water and no agglomeration triggered by the spray drying process of AuNPs is observed. The PVA@AuNP powders are coextruded with polycaprolactone to demonstrate the industrial application of dry‐state AuNPs. With PVP@AuNP the incorporation of AuNP into other stabilizing polymers via ligand exchange method is facilitated. After each step, the active surface of the AuNPs was tested by catalytic studies. Twinkle, twinkle, golden sprinkle: Gold nanoparticle composite powders were obtained by spray drying of aqueous polymer solutions with dispersed gold nanoparticles. This technique facilitates the spectrum of technical applications of gold nanoparticles, such as co‐extrusion. Ligand exchange reactions and follow‐up AuNP catalyzed reactions were possible even after longer storage of the powders. [ABSTRACT FROM AUTHOR]

We report on the properties of low-temperature phase (LTP)-MnBi particles produced by the rapid-quenching technique of spark-erosion. The as-prepared powder consists of amorphous, crystalline, and superparamagnetic particles, mostly as porous aggregates. The major fraction of the powder consists of 20-30 nm particles. A short anneal crystallizes the amorphous particles producing a high moment, >90% of theoretical MS, albeit with HC of a few kOe. If lightly milled, the agglomerates are broken up to yield HC of 1 T. These findings are supported by the x-ray diffraction pattern showing broadened peaks of the predominant LTP-MnBi phase. The combination of spark erosion, milling, and annealing has produced randomly oriented particles with (BH)MAX~3.0MGOe. The particles are expected to show record energy product when aligned along their crystallographic easy axes. [ABSTRACT FROM AUTHOR]

The influence of strain on the thermally induced dewetting mechanism of silicon films is reported. This study shows that the initial strain level in the silicon film significantly affects the final size and shape of the silicon agglomerates resulting from the film dewetting. With the increase of the biaxial strain up to 1.6%, the size of the silicon agglomerates is significantly reduced while their density increases. Moreover, the shape of the agglomerates becomes elongated when the strain favors one of the in-plane crystallographic directions to minimize the total energy of the system. A quantitative analysis of the dewetting mechanism is presented in terms of the agglomerates size and density versus the strain level. Finally, phenomenological laws are extracted, which predict the size and shape of the agglomerates. [ABSTRACT FROM AUTHOR]