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Background: Green synthesis method of nanoparticles has been developed for several years. Besides providing environmental-friendly process, green synthesis of nanoparticles using plant extract provides synergistic effect of the secondary metabolite in such antibiotic activity. The study with an intensification process in nanoparticles formation is also gaining great attention. This research deals with the green synthesis of silver nanoparticles using Datura metel flower extract for the antibacterial agent. The use of ultrasound-assisted method for the synthesis was investigated. Methods: Synthesis of silver nanoparticles (AgNPs) using Datura metel flower extract under ultrasound- assisted method has been conducted. Evaluation of the successful synthesis was done using UV-visible spectrophotometry, particle size analyzer, x-ray diffraction, and transmission electron microscopy. The prepared AgNPs were tested as an antibacterial against S. aureus, K. pneumoniae, S. pyogenes, and E. coli. Results: The ultrasound-assisted synthesis of AgNPs produces particles ranging from 25-70 nm in size; meanwhile, the reflux method demonstrated the size of 50-170 nm. These particles size represents the effect on the antibacterial activity as the ultrasound-assisted synthesized Ag NPs have higher inhibition zone towards all tested bacteria. Subsequently, these data presented the applicability of Ag NPs synthesis using an ultrasound method as a potential candidate for biomedical applications. Conclusion: The profile of UV-Visible spectra and particle size analyses demonstrated the applicability of the ultrasound technique to produce a smaller size of the nanoparticles with higher antibacterial activity.

Inspired by the viscoelastic displacement theory, we have developed a product called preformed particle gel (PPG) as conformance control agent to enhance oil recovery and control excess water production. The migration law of PPG suspension in porous media is related to its deep profile control and displacement capability. Laboratory experiments indicate that PPG suspension has good viscosity increasing, and the apparent viscosity decreases with the increase of shear rate. PPG suspension is mainly elastic, and its network structure makes it have certain shear stability. PPG particles realize migration in porous media in the way of “accumulation and blockage→pressure increase→deformation and migration”. When the ratio of the PPG particle size to the pore throat diameter δ ranges from 35.52 to 53.38, the particles can match through the porous medium. When the permeability difference of the parallel model is 5, PPG suspension has the highest profile improvement rate, 69.10%. PPG suspension can adjust the planar heterogeneity, and increase the oil recovery rate by 20.75%. The PPG suspension can effectively start “cluster"、 “film” and “blind end residual oil”, and has a high oil washing efficiency. The core NMR T2 spectrum shows that PPG suspension mainly reduces oil saturation in mesopores and macropores. After PPG flooding, the EOR capacity of small pores is the highest, 39.11%.

Lead (Pb) is one of the most paradoxical elements, both having diverse practical uses, as well as being extremely toxic to humans, and especially to children. The use of Pb records a steady growth with annual production currently exceeding 10 million metric tons. In spite of the environmental awareness of modern society, humans are still exposed to Pb through its emission by smelting and mining activities, and also by Pb-bearing mine wastes and soils. Here, we review the chemical and mineralogical forms of Pb generated from smelting and mining processes and subsequently altered in tailings, slag piles, and soils. In smelter plumes, Pb is emitted to the atmosphere either in the form of smaller nano-size particulate matter (PM) often associated with S, or larger micrometer Pb-bearing PM matter accompanied by oxide-silicate matrices. Pb-bearing phases in mine tailings and impacted soils depict a greater mineralogical and chemical complexity than those emitted from smelters and the larger particle size of this PM also leads to a lower Pb bioavailability. High resolution observations in aquatic system, soils and rock coatings impacted by smelting and mining activities show the presence of Pb-bearing phosphates, sulfides, sulfates, carbonates, and oxide nanoparticles. Larger micrometer size particles of Pb-bearing minerals form often through the aggregation of Pb-bearing nanoparticles, a process commonly referred to as crystallization through particle attachment. Mobilization of Pb within soil columns is strongly affected by the transport of colloids, especially those composed of organic matter and Fe-hydroxides because Pb is taken up efficiently by these two soil components. The extraordinary variability and complexities of all of these processes suggest that future reduction of Pb contamination in the environment and its impact on human health mainly depends on eliminating or greatly reducing Pb-release from smelting operations and tailings impoundments.

Strontium aluminate nanophosphor doped with Praseodymium was synthesized by sol–gel method. The above synthesized SrAl4O7:Pr material was characterized by SEM, PXRD, EDAX, TG and PL. By Xray diffraction analysis monoclinic structure was confirmed. Particle size was calculated by using Scherrer formula. Obtained nano particles are round interlinked shaped and leads to the formation of bigger particle. Under excitation for 360 nm, Photolumiscence emission obtained were at 395 nm, 520 nm 790 nm for UV and Green and IR regions respectively. The TG curve illustrates the three key weight loss measures for Pr doped SrAl4O7.

In many energy and combustion applications, particles experience large temperature gradients, which can affect the coagulation process due to thermophoresis. This study presents a rigorous theory of thermophoretically modified Brownian coagulation in the entire particle size regime. The theoretical derivations are based on the kinetic theory for the free-molecular regime and the harmonic mean method for the transition regime. The coagulation kernels in different size regimes can be expressed as the basic Brownian coagulation kernel times an enhancement factor. The enhancement factor represents the coagulation rate enhancement induced by thermophoresis and is a function of specific dimensionless numbers. Based on the enhancement factor, the thermophoretic enhancement effects on particle coagulation are further analyzed under a wide range of gas and particle conditions. The results show that thermophoretic enhancement effects are ignorable in the free-molecular regime, but need to be considered in the continuum regime and the transition regime. In addition, the enhancement effects increase significantly with increase of gas temperature and temperature gradient while decrease with increase of gas pressure. The present study can improve understanding of thermophoretic effects on Brownian coagulation in the entire size regime and provide a useful tool to calculate the coagulation rates in presence of thermophoresis.

Slurry pipeline transport is widely used in several industrial processes. Calculating the specific power consumption (SPC) and determining the best working conditions are important for the design and operation of transportation systems. Based on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop (SJTU-HMSPD) pipeline-resistance-calculation model, the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport system. The said system demonstrates a uniformity coefficient in the 1.26–7.98 range, median particle size of 0.075–4 mm, particle volume concentration of 10–60%, and pipeline diameter of 0.203–0.8 m. The results obtained were successfully verified against existing experimental data. The influence of parameters, such as particle-gradation uniformity coefficient, median particle size, pipe diameter, and particle volume concentration, on the SPC were analysed. The results revealed that the greater is the uniformity coefficient, the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant, median particle size slurry. As observed, the optimal transport concentration for broad-graded sand equalled approximately 48%. These results supplement the conclusions of existing research, indicating that the optimal transport concentration is approximately 30% and provides theoretical support for high concentration transportation of broad graded slurry.

Given the recent EURO 6 regulations, which include limits on particle number density (and hence size) for soot emissions from land vehicles, soot models must be capable of accurately predicting soot particle sizes. Previous modeling work has demonstrated the importance of the relative strengths of nucleation and condensation in predicting soot primary particle size. Due to this importance, a fundamental reversible model for nucleation and condensation, called the reversible PAH clustering (RPC) model, was developed in previous work through the use of statistical mechanics and the results from several recent works. In the present work, the RPC model is enhanced to include multiple nucleation (or dimerization) events from 6 different PAH size groups, resulting in 21 unique dimer pairs. In addition, a soot PAH tracking model is developed to track the amount of each PAH size group within soot particles. The addition of this model resulted in reduced computation times and the ability to investigate PAH-PAH reactions within soot particles. The results of the enhanced RPC model demonstrate that smaller PAHs are most important for the nucleation process, while small and large PAHs are important for the condensation process. These results are shown to be due to the relatively lower reversibility of condensation versus the nucleation process. These findings are discussed in light of recent experimental results in the literature and are shown to be well supported. Keywords: reversibility, PAH nucleation, PAH condensation, laminar diffusion flame, soot model

In this paper, we present the design, development, and characteristics of the novel aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols; ERC – European Research Council) and selected results from the first airborne field deployment. The instrument combines two well-established methods of real-time in situ measurements of fine particle chemical composition. The first method is the laser desorption and ionization technique, or laser ablation technique, for single-particle mass spectrometry (here with a frequency-quadrupled Nd:YAG laser at λ = 266 nm). The second method is a combination of thermal particle desorption, also called flash vaporization, and electron impact ionization (like the Aerodyne aerosol mass spectrometer). The same aerosol sample flow is analyzed using both methods simultaneously, each using time-of-flight mass spectrometry. By means of the laser ablation, single particles are qualitatively analyzed (including the refractory components), while the flash vaporization and electron impact ionization technique provides quantitative information on the non-refractory components (i.e., particulate sulfate, nitrate, ammonia, organics, and chloride) of small particle ensembles. These techniques are implemented in two consecutive instrument stages within a common sample inlet and a common vacuum chamber. At its front end, the sample air containing the aerosol particles is continuously injected via an aerodynamic lens. All particles which are not ablated by the Nd:YAG laser in the first instrument stage continue their flight until they reach the second instrument stage and impact on the vaporizer surface (operated at 600 ∘C). The ERICA is capable of detecting single particles with vacuum aerodynamic diameters (dva) between ∼ 180 and 3170 nm (d50 cutoff). The chemical characterization of single particles is achieved by recording cations and anions with a bipolar time-of-flight mass spectrometer. For the measurement of non-refractory components, the particle size range extends from approximately 120 to 3500 nm (d50 cutoff; dva), and the cations are detected with a time-of-flight mass spectrometer. The compact dimensions of the instrument are such that the ERICA can be deployed on aircraft, at ground stations, or in mobile laboratories. To characterize the focused detection lasers, the ablation laser, and the particle beam, comprehensive laboratory experiments were conducted. During its first deployments the instrument was fully automated and operated during 11 research flights on the Russian high-altitude research aircraft M-55 Geophysica from ground pressure and temperature to 20 km altitude at 55 hPa and ambient temperatures as low as −86 ∘C. In this paper, we show that the ERICA is capable of measuring reliably under such conditions.

In this work, a tapered fluidized bed (TFB) without a distributor for fluidizing carbon nanotube (CNT) was applied for improving the dead zone, blockage, and fracture of distributor, which occurred in actual production. Experiments were performed under different superficial gas velocities, static bed heights, CNT agglomerate size, and positions of pressure probe. To obtain multi-perspective and multi-scale understanding of fluidization dynamics of gas–CNT flow in the TFB without a distributor, the standard deviation, skewness, kurtosis, wavelet decompositions and homogeneous index analysis methods were adopted. Some noticeable phenomena were observed. Particle movements including inter-particle, gas–particle and particle–wall dominate dynamic characteristics. The amplitudes of pressure fluctuations of coarse agglomerated multi-walled CNT were more sensitive to the gas velocity than that of fine agglomerated multi-walled CNT. The sensitively of energy contribution of the meso- and macro-structures was that the sensitivity of the measured position was less than the sensitivity of the energy contribution by the changes of particle size, and the sensitivity of the energy contribution by the changes of particle size was less than the energy contribution by the changes of gas velocity. The fluidization quality of coarse agglomerated multi-walled CNT was better than that of fine agglomerated multi-walled CNT, which was verified by the skewness and wavelet analysis.

Filter cake is critical to maintaining the stability of the excavation face of an underwater shield tunnel in a high-permeability stratum. In a high-permeability formation, generating an effective filter cake on the excavation face is difficult with a pure bentonite slurry, which penetrates the ground and may not achieve the required suspension pressure. Determining how to efficiently and quickly form a thin and low-permeability filter cake on the tunnel working face has become a key engineering problem in the construction of slurry shield tunnels in high-permeability strata. In this study, the relationship between slurry viscosity and the slurry pressure gradient of pure bentonite was established by performing slurry permeability experiments. The influence of slurry viscosity on the formation of the filter cake in a high-permeability formation was studied under different pressure gradients. In addition, the effect of additive particle size on the slurry filter cake formation was analyzed by introducing additives with different particle sizes to pure bentonite slurries with different viscosities. The test results indicate that (1) for the pure bentonite slurry, the critical initial pressure gradient can be used as a rough indicator of the formation of the filter cake, and the relationship between the critical maximum pore diameter and the average pore diameter of the formation can be compared to establish and analyze the formation law of the slurry filter cake; (2) adding particles to the slurry can enhance the effect of the pure bentonite slurry; and (3) adding coarse-grained materials can effectively improve the film-forming effect. The slurry is more compact when the particle size is close to the average pore size of the formation.

Background: Bacillus Calmette-Guerin (BCG) is a vaccine used to protect against tuberculosis primarily in infants to stop early infection in areas of the world where the disease is endemic. Normally administered as a percutaneous injection, BCG is a live significantly attenuated bacteria that is now being investigated for its potential within an inhalable vaccine formulation. This study investigates the feasibility and performance of two jet and two vibrating mesh nebulizers aerosolizing BCG and the resulting particle characteristics and residual viability of the bacteria postaerosolization. Methods: A jet nebulizer (Collison), outfitted either with a 3- or 6-jet head, was compared with two clinical nebulizers, the vibrating mesh Omron MicroAir and Aerogen Solo devices. Particle characteristics, including aerodynamic particle sizing, was performed on all devices within a common aerosol chamber configuration and comparable BCG innocula concentrations. Integrated aerosol samples were collected for each generator and assayed for bacterial viability using conventional microbiological technique. Results: A batch lot of BCG (Danish) was grown to titer and used in all generator assessments. Aerosol particles within the respirable range were generated from all nebulizers at four different concentrations of BCG. The jet nebulizers produced a uniformly smaller particle size than the vibrating mesh devices, although particle concentrations by mass were similar across all devices tested with the exception of the Aerogen Solo, which resulted in a low concentration of BCG aerosols. Conclusions: The resulting measured viable BCG aerosol concentration fraction produced by each device approximated one another; however, a measurable decrease of efficiency and overall viability reduction in the jet nebulizer was observed in higher BCG inoculum starting concentrations, whereas the vibrating mesh nebulizer returned a remarkably stable viable aerosol fraction irrespective of inoculum concentration.

Atmospheric nanoparticles (PM0.1 µm) are a major cause of environmental problems and also affect health risk. To control and reduce these problems, sources identification of atmospheric particulates is necessary. Combustion of bituminous coal and biomass including rubber wood, palm kernel, palm fiber, rice stubble, rice straw, maize residue, sugarcane leaves and sugarcane bagasse, which are considered as sources of air quality problems in many countries, was performed. Emissions of particle-bound chemical components including organic carbon (OC), elemental carbon (EC), water-soluble ions (NH

This work presents the effects of several factors on the mechanical strength of calcium phosphate cement (CPC) based on alpha tricalcium phosphate and correlates the results with the microstructure and percentage of conversion to hydroxyapatite. Conversion rate increased by raising the setting temperature in the studied range (4–90 °C), but the strength exhibited an increasing-decreasing trend due to changes in the morphology of hydrated crystals. Plate-like crystals were formed in the range of 22–60 °C, mechanically reinforcing the material, whereas the formation and refinement of needle-like crystals at higher setting temperature decreased the strength. Moreover, cements with dissimilar particle sizes had different optimal hydrolysis temperatures that resulted in the maximum strength. The finest powder led to higher strength at lower setting temperature due to the formation of a more compact crystal network and higher conversion. Therefore, optimization of powder particle size may allow to achieve the highest possible strength at room temperature, being beneficial for the production of the strong pre-set CPC-based implants without the use of energy. Furthermore, the particle size can be also engineered to produce formulations that develop the highest strength at physiological temperature, with application as injectable bone grafts. The incorporation and crosslinking of gelatine further increased the mechanical strength of pre-set cements by bridging the hydroxyapatite crystals, the setting temperature showing a similar effect to that of gelatine-free cements. In contrast, moisture decreased the strength and reduced the brittleness by the solvating intramolecular association between hydroxyapatite crystals and between gelatine molecules. Moreover, large cement bodies were slightly weaker than small ones, but the size effect was not statistically significant.

The aim of this work is to investigate the effects of magnetic field and ionic wind on the ability of a wire-plate electrostatic precipitator (ESP) to trap fine particles. A theoretical model of multi-field coupling between gas flow field, particle dynamic field and electromagnetic field was established, and a grid model was built by GAMBIT software. The collection efficiency under different gas velocities was calculated in FLUENT software where the electric field force and the magnetic field force were introduced by User Defined Function (UDF). The numerical results indicate that both ionic wind and applied magnetic field can effectively improve the PM2.5 collection efficiency in a wire-plate ESP, and the smaller the particle size, the more obvious the improving effects are. With the increase of gas velocity, PM2.5 collection efficiency has a nonlinear declining trend, but the contribution of ionic wind or magnetic field to the collection efficiency increases. The trapping performance of the wire-plate ESP under the combined action of the two factors is better than that of considering one of them separately. The research results can open up a new design idea and direction for the performance upgrading of the wire-plate ESP.

Calcium alumino-titanate (CAT), a secondary material obtained from ferrotitanium slag, was used as a hibonite source to prepare CaAl12O19–MgAl2O4–Al2O3 castables. The restructuring effect of CAT aggregate was compared by replacing tabular alumina aggregates with CAT aggregates of different particle sizes. The effects of CAT particle size on cold mechanical strength and thermal shock resistance of CaAl12O19–MgAl2O4–Al2O3 castables were studied. The results showed that CAT aggregates with particle size of 5–3 or 3–1 mm led to more internal cracks or pores and reduced the cold mechanical strength of the castable samples fired at 1600 °C for 3 h. The use of CAT aggregates with particle size of 1–0 mm led to the formation of a well-bonded CAT aggregate and matrix, improving the cold mechanical strength and thermal shock resistance of the castable samples fired at 1600 °C for 3 h. The enhancement mechanism of fine CAT aggregates in this process was proposed based on the sintering of the matrix–aggregate interface with the formation of Ca(Al, Mg, Ti)12O19.

Monoclonal antibody (mAb) based therapies may provide a valuable new treatment modality for acute and chronic lung diseases, including asthma, respiratory infections, and lung cancer. Currently mAbs are delivered via systemic administration routes, but direct delivery to the lungs via the inhaled route could provide higher concentrations at the site of disease and reduced off-target effects. Though lyophilized mAbs may be reconstituted and delivered to the lungs using nebulizers, dry powder inhalers provide a more patient-friendly delivery method based upon their fast administration time and portability. However, particle engineering processes required to prepare respirable dried powders for DPI delivery involve multiple potential stressors for mAbs, which have not been fully explored. In this study, a systematic examination of various aspects of the particle engineering process (atomization, freezing, drying, and storage) was performed to further understand their impact on mAb structure and aggregation. Using anti-streptavidin IgG1 as a model mAb, atomization settings were optimized using a design of experiments approach to elucidate the relationship between feed flow rate, formulation solid content, and atomization airflow rate and protein structural changes and aggregation. The optimized atomization conditions were then applied to spray drying and spray freezing drying particle engineering processes to determine the effects of freezing and drying on IgG1 stability and aerosol performance of the powders. IgG1 was found to be particularly susceptible to degradation induced by the expansive air-ice interface generated by spray freeze drying and this process also produced powders that exhibited decreased storage stability. This study further delineates the design space for manufacturing of respirable biologic therapies and is intended to serve as a roadmap for future development work.

As a state-of-the-art secondary battery, lithium-ion batteries (LIBs) have dominated the consumer electronics market since Sony unveiled the commercial secondary battery with LiCoO2 as the negative electrode material in the early 1990s. The key to the efficient operation of LIBs lies in the effective contact between the Li-ion-rich electrolyte and the active material particles in the electrode. The particle properties of the electrode materials affect the lithium ion diffusion path, diffusion resistance, contact area with the active material, the electrochemical performance and the energy density of batteries. To achieve satisfied comprehensive performance and of LIBs, it is not only necessary to focus on the modification of materials, but also to balance the properties of electrode material particles. Therefore, in this review, we analyze the influence of particle properties on the battery performance from three perspectives: particle size, particle size distribution, and particle shape. A deep understanding of the effect and mechanism of particles on electrodes and batteries will help develop and manufacture practical LIBs.

Monte Carlo method is a stochastic approach that can simulate different micro-mechanisms occurring in spray fluidized bed (SFB) agglomeration. As no model covered the simulation of continuous SFB agglomeration process existing before, an event-driven constant volume Monte Carlo model is proposed. By adding particle feed and discharge events that take place periodically, the Monte Carlo model is extended to simulate continuous SFB agglomeration process. In these events, new particles are fed, and individuals are randomly selected and removed according to the feed rate and the change in bed mass. The experimental results show that the decrease of feed rate or bed mass increases the particle size. The comparison of experimental and simulation results shows that the continuous Monte Carlo model can predict the evolution of the particle size distribution with collision frequency prefactor 0.05 and breakage probability 0.17%. The development of bed mass in experiments can be reproduced in the simulations.

A highly sensitive, large throughput and wide dynamic range (in the aspect of size and material type) broadband tunable microwave interferometer based rectangular waveguide wear debris detection system is presented. Passing of (non)ferrous and (non)conductive particles through the sensor, which causes inductance and/or capacitance changes, are detected as transmission signal variations of the system. We first demonstrate the sensing principle with the aluminum particle of 800 μm and epoxy resin particle of 1 mm3 at 6 GHz. Then, the effects of particle size and flow speed are tested with aluminum particles ranging from 200 μm to 1.8 mm. The measurement results show that the system is able to measure particle sizes with known material and differentiate nonconductive particles from conductive ones. With the proposed data processing techniques, this system is capable of detecting as small as 76 μm particles within an 8 mm outer diameter tube. And with future improvements on sensitivity and particle material characterization, the proposed system has the potential to differentiate (non)ferrous and (non)conductive particles and measure their sizes as a real-time wear debris sensing devices for rotating and reciprocating machines.

Most of current centrifugal classifiers can only obtain coarse products and fine products. With the development of industry, particles with different average particle sizes and narrower distribution widths are required. In order to obtain the product in a specified range, classification has to be carried out repeatedly, resulting in higher time and energy cost. For this problem, a novel air classifier that can obtain multi-product with different particle size was designed. Because of the different trajectories of particles with different sizes, particles are sorted and separated in the classifier and flow into different outlets, where a variety of products with increasing average particle size were obtained. There are many feasible matching schemes that the particles do not hit the classifier wall and make full use of classifier space. CFD is employed to investigate particles distribution law and flow field character at different matching schemes, the effect of particle classification at different particles distribution law. Classification size ratio (CSR) is used to evaluate separation effectiveness, the greater CSR, the better separation effectiveness. Experiment results show when the accelerating flow field velocity is 4m/s, the classifying flow field angle is 60°, the CSR at outlet 1∼5 is 3.99, 1.56, 0.96, 0.61, 0.5. As the accelerating flow field velocity increase from 4 m/s to 7 m/s, the separation effectiveness is slightly improved, CSR increase to 4.55, 1.77, 1.03, 0.68, 0.54. There are obvious differences in CSR between adjacent outlet, which shows a variety of products can be obtain in multi-product classifier.

Particle size reduction of the active pharmaceutical ingredients (APIs) in the range of 1–5 µm is required for efficient drug delivery through the nasal route. The traditional micronization techniques such as jet milling, spray drying and liquid antisolvent recrystallization exist to produce the particles in this size range. However, these techniques have many disadvantages such as irregular particles, broad particle size distribution, chemical and thermal degradation. Supercritical fluid-based micronization techniques have been proved as a promising technology to produce spherical particles in this size range. In this work, a model is developed to predict the particle size distribution of API recrystallized by a supercritical antisolvent recrystallization process. Rifampicin is considered a modal API to be recrystallized. In this process, the API is first dissolved in dimethyl sulfoxide and this solution is sprayed into a precipitator. The precipitator has carbon dioxide at supercritical conditions i.e. above its critical temperature and pressure. Supercritical Carbon dioxide acts as an antisolvent as rifampicin is not soluble in it. Diffusion of carbon dioxide into solution droplet decreases the solubility of rifampicin in dimethyl sulfoxide and the crystallization process starts. Primary nucleation and diffusion-based growth mechanism are considered to calculate average particle size and particle size distribution. This model is solved in MATLAB 7.1 and the trend of particle size distribution predicted by the model is found to be similar to particle size distribution by experiments.

Hydroxyapatite (HAP), which is chemically represented as (Ca10(PO4)6(OH)2), is one of the main inorganic material of vertebrate bone and teeth. The bioceramic material is used as a substitute for deficient bone tissue because of its similarities to crystallographic and chemical composition of teeth and bone. HAP is extensively used in various biomedical applications because of its excellent properties, such as bioactivity, non-toxicity, biocompatibility, non-immunogenicity and osteoconductivity. In this work, hydroxyapatite powder was synthesized using polyoxyethylene lauryl ether (Briji-35) as a surfactant and dimethyl sulfoxide as a primary surfactant through microemulsion method. The obtained products were characterized by FTIR, XRD and SEM. The result indicated that, the Briji-35 played an important role for the formation of nano-hydroxyapatite particle with good crystallinity and particles with uniform morphology besides controlling the particle size of nano-HAP. The biomedical application studies of the as-synthesised material are yet to be studied.

A thorough understanding of chemical composition, particle pH, and pollutant emissions is essential to address the climate and human health effects of atmospheric particles. In this study, we used a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Scanning Mobility Particle Sizer (SMPS) to characterize the composition of submicron particles. Moreover, we applied the ISORROPIA-II model to analyze the particle acidity effect on the compositional characterization of submicron particles from December 22, 2016 to January 7, 2017 in Albany, New York, USA. The results indicated that aerosols with mobility diameter from SMPS in the range 200–400 nm were the main contributors to the mass during the measurement period. The dominance of organics (47%) and sulfate (16%) was similar to previous observations in the eastern United States in Winter 2015, while the fraction of nitrate (23%) was much higher. Moreover, nitrate could easily form at colder temperatures and lower RH levels even when there were more acidic particle periods during the measurement period in Albany. The ISORROPIA-II model indicated that there were more acidic particles, which was estimated using pH values. Lower temperature conditions tended to favor nitrate formation. The nitrate concentration exceeded that of sulfate in the measurement period, even though the SO2 and NOx emissions were similar. The organics in submicron particles were strongly influenced by the local emissions in winter. However, the inorganic compounds in submicron particles could be derived from regional transport as their pollution sources originated from different directions. This may help strategize emission reductions in the future.

In many applications, amorphous particles bond together through a phenomenon known as sintering to minimize their surface energy. Water is a plasticizer for many food and pharmaceutical powders and the strong reduction in viscosity induced by moisture absorption can accelerate strongly particle sintering [1]. Numerical simulations of particle sintering usually neglect the coupling with moisture transfer, considering a uniform viscosity throughout the particle. In this study, a novel approach based on solving Navier-Stokes equation using an Arbitrary Lagrangian-Eulerian (ALE) approach is proposed to model the dynamics of particle sintering coupled with moisture transfer. Maltodextrin DE21 is considered as an industrially relevant example of amorphous particles. Due to moisture uptake, strong gradients of viscosity can exist in the particles undergoing sintering. FEM simulations consider accurately the forces acting on the contact area between the particles, leading to slower dynamics than commonly used approximate analytical models. This study highlights that FEM simulations considering a homogeneous moisture and viscosity within the particles are in many cases sufficiently accurate and identifies the limits of validity of this assumption. In the conditions considered in this study, the intraparticle gradients were found to condition significantly the sintering dynamics only when particle diameter is above 1.5 mm. The particle size affects strongly both the dynamics of sintering and of moisture transfer. Moreover, higher external relative humidity leads to a lower viscosity and a faster sintering kinetics. The initial water content was found to have a lower impact in the conditions studied. This coupled simulation approach can be used to identify conditions reducing the risk of caking during the storage of amorphous powders or to master sintering during powder structuration processes. Furthermore this study helps identifying when simpler simulation approaches considering homogeneous particles can be safely used and shows the limitations of simplified analytical models.

In order to slow down the cooling rate of mixture and reduce the low-temperature cracking of asphalt pavement in large temperature difference areas, polyurethane solid–solid low-temperature phase change materials (PSLPCMs) were prepared by prepolymer method in this study. The PSLPCMs were incorporated into hot mix asphalt mixture to prepare PSLPCMs particle asphalt mixture. The pavement performance and phase change temperature control behavior of this special type of mixture were analyzed from the perspectives of particle content and particle size. Studies have shown that PSLPCMs have good phase change thermal storage performance and thermal stability. Different PSLPCMs content and particle size have certain improvement effect on the high temperature stability and low temperature crack resistance of the mixture, and have no obvious adverse effect on the water stability of the mixture. At the same dosage, with the increase of particle size, the improvement effect of PSLPCMs particles on the road performance of the mixture is more obvious. With the increase of PSLPCMs particle content, the specific heat capacity of asphalt mixture increases, and the thermal conductivity decreases. The temperature regulation effect of asphalt mixture shows an increasing trend, and the cooling rate slows down. The PSLPCMs particles with particle size of 1.18–2.36 mm have better improvement effect on the temperature regulation performance of the mixture. When the content of PSLPCMs is 7 wt%, the maximum temperature regulation effect of the mixture reaches 3.4 °C.

Many researchers have been focused on the better way to increase the utilization of industrial by-products for the road construction and tile productions. However, none of the research results have reported the functional characteristics of SMS slag. This paper deals with the processing and functional characterization of SMS slag using novel powder metallurgy method. The particle sizes, mineralogical phases, and dielectric constant were determined by XRF, BET, XRD and Impendence analyzer respectively. The effect of reduction of particle size on the functional properties of SMS slag was revealed that reduction in particles of slag decreases the dielectric properties of slag at 600 °C. As results, 50.65 wt% of free CaO phase was present in the slag samples. It is suggested that SMS slag can be useful for the electronic packaging applications.

A new method was proposed for the evaluation of the efficiency of microwave heating asphalt mixtures and the influences of density and particle sizes of reclaimed asphalt pavement (RAP). Temperature distributions of asphalt mixtures with density of 1.35 and 2.02 t/m3 and particle size ranges of 3–6, 6–9.5, and 9.5–13.2 mm along the direction of microwave propagation were experimentally evaluated and the results obtained for the efficiency of microwave heating RAP with different densities and particle sizes were compared based on the proposed method. Also, increase of the particle size of RAP with basalt aggregates higher ability of microwave absorption.

Non-uniform sand retention behavior often occurs to the serviced screen deteriorating erosion. However, this phenomenon is poorly understood. This paper presents a numerical study of the sand retention on wire-wrapped screens, with special reference to non-uniform behaviors. This is done by the combined approach of computational fluid dynamics (CFD) and discrete element method (DEM). The validity of the model has been validated for dry and wet sand screen systems. It is used here to study sand retention behaviors at different solid concentrations and particle size distributions (PSD). Via this model, five distinct sand retention modes are identified: No sand retention (Mode I), partial sand retention (Mode II), sand retention with slow sequential bridging (Mode III), sand retention with fast sequential bridging (Model IV) and sand retention with instantaneous bridging (Mode V). Modes II and III belong to non-uniform sand retention, which develops strong local flows that induce local erosion or hot spot on the screen. A phase diagram is introduced to predict these five modes and their transition with respect to solid concentration and PSD. Additionally, the predicted flow and force structures are analyzed in detail. The results indicate that the bridging over a slot heavily relies on the particle accumulation on the screen. A new screen with a converging slot configuration is proposed to improve this particle accumulation. This improvement helps develop uniform sand retention on the screen.

Annotation The literature shows that practically no attention has been paid to the size and shape of the particles of bulk ammonia borane (NH3BH3). The published results about the influence of the dispersity of this hydride on its dehydrogenation are not numerous and contradictory. This work presents new results on the low-temperature solid-state dehydrogenation of bulk NH3BH3. The samples under study were recrystallized using different procedures and had, therefore, different particle characteristics. The reactivity of these samples of NH3BH3 was compared on the basis of thermal analysis data obtained under non-isothermal conditions, including the Kissinger kinetics, and H2 evolution under isothermal conditions (84–96°С) using Avrami-Erofeev kinetics. The finely dispersed sample with a particle size of 100 was synthesized and described for the first time. It was suggested that its relatively high reactivity was determined by its ordered structure. These results show the importance of further investigations of bulk ammonia borane with different types of particles.

We report a joint experimental and numerical study on the global thermal performance of a novel windowless vortex-based cavity receiver for potential thermal processing of suspended particles. This systematic study assesses the coupled influence of particle loading, Froude and Stokes number through variation of the inlet mass flowrate, particle size and loading on the global performance of the Solar Expanding Vortex Receiver-Reactor (SEVR) under steady-state conditions. The experiments employ polydispersed CARBO CP ceramic particles that are heated with an 18-kWel Metal Halide three-lamp solar simulator. A numerical study was also performed using computational fluid dynamics (CFD) software ANSYS/CFX 2019 R1. It was found that the particle volumetric loading and Froude number have primary controlling influence, while the Stokes number has a secondary influence on the global performance for these conditions. An overall thermal efficiency of 67% was obtained under high particle loading and Froude numbers.

Metal powders used in directed energy deposition additive manufacturing are subjected to particle-particle and particle-gas interactions not captured through traditional powder characterization. Variations in powder performance were identified through mass flow rate measurements of lean (UNS S32101), standard (UNS S32205), and super (UNS S32750) duplex stainless steel powders specified for directed energy deposition on three commercial powder feeders. Across these different systems, the lean grade consistently displayed the lowest mass flow rates. Differences between the three powders were only identified with advanced powder and rheological characterization tools, which linked particle characteristics and rheological properties to powder flow and performance. A slight shift to a larger size distribution in the lean grade produced a higher percentage of larger particles with higher masses that resisted motion and increased flow resistance. Higher flow resistance was captured through higher cohesion strength and fluidization measurements during rheological testing.

Hypothesis: While the lack of efficient tools yielding controllable uniform saturation ratios (S) has delayed basic experimental heterogeneous nucleation studies, common diffusive condensation particle counters (DCPCs) could fill this gap if their S-variation were minimized by increasing the proportion of sheath gas (σ) surrounding a central core of purified clusters. Analysis: We measure the activation probability P of Tetraheptylammonium Bromide cluster cations (THA-Br)n-1THA+ in Kanomax’s fast CPC while controlling S through the saturator and condenser temperatures (Ts, Tc), varying σ, and changing the size (n) of purified salt clusters via high resolution mobility selection. Findings: Experimental curves P(Ts,n) obtained in 1-butanol/air at fixed Tc (13 °C) and variable n and Ts (3 ≤ n ≤ 16; 30 ≤ Ts ≤ 40 °C) rise sharply versus both n and Ts. Their steepness increases five-fold with increasing σ to about σ = 75%, with little effect thereafter. Measurements changing S would yield size distributions of unknown aerosols at fairly high resolution. Comparing P(Ts,n) data with predictions from capillary theory suggests that basic heterogeneous nucleation measurements can be carried out, but instrument improvements are still needed.

Hydroxyapatite (HAP) [Ca10(PO4)6(OH)2] is an excellent bio-ceramic material for artificial bone substitution in biomedical field owing to its chemical and crystallographic similarities of natural bone and teeth. In this research work, we have attempted the synthesis of hydroxyapatite powders with controllable size in the presence of three different surfactants sodium dodecyl sulphate (SDS) which is an anionic surfactant, cetyl trimethylammonium bromide (CTAB) as a cationic surfactant and poly vinyl alcohol (PVA) as a non-ionic surfactant. The as-synthesised HAP powders were characterised by analytical techniques such as FTIR, XRD and SEM. The results have shown that the non-ionic surfactant is a better choice for developing this bio-nanomaterial due to its good dispersing power than CTAB and SDS. The results have also indicated that, nano-hydroxyapatite particle has a uniform morphology, well crystallinity and the particle size was controlled with the use of non-ionic surfactant. The crystallite size was calculated using Scherer’s formula. Experiments were performed under controlled environment by maintaining the required pH, concentration and temperature. The biomedical application studies of the as-synthesised material are yet to be studied.

Introduction: The amentoflavone (AMF) loaded polymeric sub-micron particles were prepared using supercritical antisolvent (SAS) technology with the aim of improving the anticancer activity of AMF. Methods: Zein and phospholipid mixtures composed of Hydrogenated Phosphatidylcholine (HPC) and egg lecithin (EPC) were used as carrier materials and, the effects of carrier composition on the product morphology and drug release behavior were investigated. When the mass ratio of Zein/HPC/ EPC was 7/2/1, the AMF loaded particles were spherical shape and sub-micron sized around 400 nm, with a drug load of 4.3±0.3 w% and entrapment efficacy of 87.8±1.8%. The in vitro drug release assay showed that adding EPC in the wall materials could improve the dispersion stability of the released AMF in an aqueous medium, and the introduction of HPC could accelerate the drug release speed. Results: MTT assay demonstrated that AMF-loaded micron particles have an improved inhibitory effect on A375 cells, whose IC50 was 37.39μg/ml, compared with that of free AMF(130.2μg/ml). Conclusion: It proved that the AMF loaded sub-micron particles prepared by SAS were a prospective strategy to improve the antitumor activity of AMF, and possibly promote the clinical use of AMF preparations.

Pneumatic conveying of coal particles widely used for environmental friendliness and automation. In this study, orthogonal experiments were carried out in 90° elbows of large coal particles (7–15 mm) to study the effect of the elbow shape, particle size, airflow velocity, and gas supply pressure on elbow erosion. Elbows with double-layer wall structures were designed to present the erosion characteristics, particle breakage ratio, and pressure drop. Results indicate that the angle between the erosion center and the tangential direction of the elbow inlet is approximately 25°–30°. The elbow shape and airflow velocity have significant effects on all three evaluation indices, whereas the particle size and gas supply pressure have significant effects on the pressure drop. The optimal parameters of each factor were confirmed: the blind elbow with a plug, particle size of 9–11 mm, airflow velocity of 20 m/s, and gas supply pressure of 0.4 MPa.

The aim of this research is to improve slurry impeller material erosion wear analysis. The impeller of the pump was made of epoxy resin. The purpose of this erosion test was to see how the rotational speed, solid concentration, time period, and particle size were affected. As the erodent substance, water was utilized. Different particle sizes, rotating speeds, time durations, and solid concentrations were used in the erosion wear studies. These tests were conducted at 4 to 6 distinct speeds of 30, 60, 90, 120, 150 and 180 m/s, with time periods of 30, 60, 90, and 120 min. For assessing the erosion resistance of epoxy resins, a Solid Particle Erosion (SPE) tester is used. Significant wear resistance to erosion has been observed. The following were the process factors that affected erosion wear loss: velocity > angle > concentration > particle size > time. The signal-to-noise ratio of epoxy resin varies with velocity from 0.012 to 0.0053, 0.0118 to 0.0067, and 0.0042 to 0.0114., Taguchi technique was used to examine the effect of controlled process parameters on slurry erosion wear of pump impeller material.

To deeply knowledge of the flow behaviors of pulverized coal particles in dense gas–solid two-phase flow, a multi-scale analysis method based on electrostatic sensor array is applied for the multi-scale characterization of flow behaviors of dense gas–solid flow. The experimental results indicate that: for steady flow, with the increment of conveying pressure difference, the individual particles increase and the particle clusters decrease, the individual particle distribution is always inhomogeneous but the particle cluster distribution tends to be more homogeneous over the cross-section of pipe, while the average flow behavior of pulverized coal particles is always in the relatively static state. For unsteady flow, the average flow behavior of pulverized coal particles is dynamic, and the flow behaviors of the multi-scale flow structures over the cross-section of pipe are all significantly inhomogeneous. Moreover, the effect of particle size on flow behavior of pulverized coal is also investigated and validated.

Natural gas hydrates are mostly formed in low-permeability and fractured muddy sedimentary formations. Adding suitable nanoparticles to the drilling fluid system can improve its filtrate resistance and fracture plugging, and effectively weaken the invasion of drilling fluid into the reservoir. However, it is likely that nanoparticles promote hydrate formation and accumulation in wellbores and will induce accidents. Therefore, this study investigated the effect of hydrophilic silica nanoparticles with particle sizes of 30 nm, 60 nm, and 80 nm and concentrations of 0.5–4.0 wt.% on hydrate formation during upward migration of methane gas using a dynamic simulation system for hydrate formation in a wellbore. The experimental results show that under the condition of methane gas migration, hydrophilic silica nanoparticles inhibit hydrate formation. The inhibition effect increased with an increase in the particle size under a constant concentration, whereas it first increased and then decreased with increasing nanoparticle concentration under a constant particle size. The strongest inhibition effect was observed at a hydrophilic silica nanoparticle concentration of 2.0 wt.%. The influence of hydrophilic silica nanoparticles on hydrate formation may be mainly determined by their hydrophilic properties, heat and mass transfer, and gas migration in the wellbore. Our research indicates that hydrophilic silica nanoparticles can be added to hydrate drilling fluid systems if their concentration can be properly controlled.

The morphology evolution of copper powder was studied under various ball-milling experimental conditions, such as low and high rotation speeds and a ball diameter of 1 mm and 10 mm. A scanning electron microscope and X-ray diffractometer were used to analyze the copper powder particle size, morphology, structure, and crystallite size. The effect of ball size on copper powder particle morphology in dry-type milling was studied using a planetary ball mill. Spherical copper powders were obtained by ball milling at a high rotation speed and with a ball diameter of 1 mm. The experimental results suggest that the particle size and morphology can be controlled by changing the milling conditions during the ball milling. Ball motion was simulated by using a three-dimensional discrete-element model to obtain the force, energy, and power of the ball motion in the ball mill for two different ball sizes and low and high rotation speeds.

Direct impingement (DI) erosion testing of steel and cobalt-based alloys is conducted with particles entrained in air and water. The tests are performed using 75- and 300-μm silica particles with three particle velocities and five impact angles. The mass loss results are used to develop an empirical equation that contains an explicit exponential term for the particle size effect. The erosion equation obtained from the gas jet experiments is implemented into a CFD solver with Lagrangian particle tracking for the liquid-submerged geometry. The CFD-based erosion predictions agree fairly with the experimental measurement for both particles. Strong effect has been observed for the exponential correction term in the erosion equation for liquid-solid flow cases; particularly with small particles at low impact velocities.

Prediction of combustion characteristics of aluminum particle is of great significance for a variety of propulsion and power systems to achieve optimal energy release within a limited residence time. In this study, a diffusion-controlled combustion model for micro aluminum particle was developed and validated to predict the burning time and capture the evolution of particle size during combustion in environments with multiple oxidizers. Thereafter, the key factors influencing particle combustion were evaluated including particle size, ambient temperature, oxidizer concentration and characteristics of oxide cap. The burning time drops as the oxidizer concentration and the ambient temperature increase, and their influences on burning time become weakened gradually. The effect of oxidizer concentration presents more obvious than ambient temperature. As the number of oxide cap increases from 2 to 5, the burning time rises by 6.9%–27.4%. Then a non-linear empirical equation was proposed to describe the effective oxidizer, which is more accurate than the existing linear correlation, especially for H2O. Finally, a formula capable of predicting the burning time was proposed and validated, providing a convenient and accurate method for practical application.

The influence of particle size and functional group as one of the pivots for particle interaction that enhances electrorheological performance were studied by varying the particles to micron and nanometer-sized polyacrylonitrile (PAN) spheres for rheological comparability analysis. Emulsion polymerization and catalytic amination with diethylene triamine (DETA) were used to successfully synthesize ER particle samples and then dispersed in silicon oil for suspension analysis. Micron-sized particles presented a large surface electron density for high conversion of nitrile groups with DETA than in nano. Polar groups from DETA improved particle polarization which enhanced ER effect by increasing yield strength by more than 10 folds on raw PANs. However, small sized nano particle exhibited relatively reduced ER effect owing to aggregation by Brownian motion pronouncing aminated micro PAN with the best ER activity followed by the aminated nano PAN, micro PAN and nano PAN as follows.

Flow of cohesive granular materials with different moisture contents was examined in a four-bladed mixer via the discrete element method (DEM). Firstly, the mixer diameter (D) was increased while keeping the particle diameter (d) constant. It was observed that when the mixer diameter to the particle diameter ratio (D/d) was larger than a certain critical size (D/d ≥ 75), granular flow behaviors and mixing kinetics followed simple scaling relations. For D/d ≥ 75, flow patterns and mixing kinetics were found to be independent of system size, and velocities of particles scaled linearly with the tip speed of the impeller blades and particle diffusivities scaled with the tip speed of the blades and mixer diameter. These results suggest that past a certain system size the flow and mixing of cohesive particles in large-scale units can be predicted from smaller systems. Secondly, system size was kept constant and particle diameter was changed and it was observed that by keeping the Bond number constant (by changing the level of cohesion) the flow behavior and mixing patterns did not change, showing that larger particles can be used to simulate flow of smaller cohesive particles in a bladed mixer by matching the Bond numbers.

In this paper, CFD-DEM method coupled with the thermochemical submodel is employed to simulate the char combustion in a three-dimensional (3D) bubbling fluidized bed. The influences of particle properties on the particle profile, temperature, and reaction rates are investigated in horizontal and vertical directions. The results showed char particles with four types of diameters have the similar characteristic distributions and variation tendency to those with different densities. The major difference is that the particle-averaged char combustion rate increases with the particle size, but slightly decreases with the increment of density. The mixing index of fuel particles and the internal relation between particle mixing, heat transfer, and reaction are also explored. It is revealed that the particle content profile is apparently affected by the movement of bubbles. The uniformity of distributions of particle temperature, CO and CO2 concentrations is consistent with fuel particle profile in most cases.

The increasing significance of products consisting of elongated particles or fibres along with a lack of understanding flow properties of fibrous bulk solids in processes urge for appropriate test procedures. Therefore, a tensile tester was designed with respect to the special needs in terms of test techniques of those bulk solids. The procedure of tensile strength determination was tested with regard to several possible influencing factors. Following from that, the manner of filling and filling height were identified to have the greatest influence on results. Furthermore, it is shown that the developed load system is capable of improving the repeatability of test results for fibrous bulk solids. Based on the derived standard procedure, systematic tests were carried out on beech and spruce chips in three different fractions each as well as model materials such as polypropylene fibres and differently sized bunches of glass fibres. The biomass materials have been characterised by dynamic image analysis prior to and after experiments resulting in particle size and shape factor distributions. It is found that tensile strength is affected by particle shape, size, roughness and interparticle contact area.

Particle-laden turbulent flow under saturated electrostatic field in 90-degree bend pipe at Reb = 58000 is investigated using one-way coupled Large Eddy Simulation (LES) with a Lagrangian particle tracking technique. Drag, lift, buoyancy, gravity, and electrostatic force are considered. Three particle sizes (dp = 5, 10, 50 μm, St = 5.47, 21.91, 547) are considered. The results show that particle concentration is higher in outer bend than that in inner bend and the concentration increases with particle size. At the stagnation point of Dean vortices near the inner arc of bend, particle concentration is significantly increased under the synergy effect of electrostatics and secondary flow. In addition, particles trapped in the viscous layer are difficult to resuspend under electrostatic effect. Particle concentration near the wall under the presence of electrostatics is larger than that under the absence of electrostatics. However, at the bend, particle concentration in the core region under the presence of electrostatics is lower than that in the absence of electrostatics. For particle behavior, drag force plays the most important role in the core region while electrostatic force dominates the near wall region and causes particles to accumulate there.

A quantitative understanding of particle rigid body (RB) motion that inherently accompanies grain boundary (GB) diffusion is highly desirable to understand and control the dynamic interplay between coarsening and densification during solid state sintering. By computer simulation using a multi-phase-field approach, we analyze systematically the roles played by each of these processes at different stages of the shrinkage of the internal pore in a three-particle green body as a function of particle size as well as thermodynamic and kinetic factors of interfaces. We demonstrate that particle RB translation promotes both neck growth, and pore rounding and shrinkage. Moreover, the forces acting at GBs and pulling neighboring particles towards one another dynamically evolve as particles fuse. In contrast, particle RB rotation has no contribution to pore shrinkage. The translational force acting on an individual particle varies with not only its size, but also the number and sizes of its neighboring particles.

Aluminum (Al) particles are regarded as general addictive into solid propellants not only as an extra energy source but also as a metallic damping-carrier on combustion instability. It is possible that the stability in propellant can be improved through partial Al substitution. However, knowledge of unsteady combustion characteristics of Al particles has been insufficient. In order to explore the unsteady combustion and attenuation characteristics of Al particle, a methane micro-combustor is designed. The acoustic oscillation of combustor is found to be excited, regardless of the Al particles mass of diameter. Moreover, the effects of 1) particle size and 2) mass are examined in detail. The burning of micro-sized Al particles in present experiment is attributed to melt dispersion mechanism. The rupture time is in the range of 2.18 ms to 2.81 ms for Al particles with mean diameter of 10 μm, 20 μm and 30 μm. With the increasing of particle size, the sound level of high-frequency oscillation increases from 65 dB to 85 dB. However, the attenuation effect for high-frequency oscillation is weakened for larger particle size. Finally, it is found that the pressure growth rate can be dramatically increased from 1000 Pa/s to 11,000 Pa/s and the peak amplitude of high frequency oscillation is augmented, as the Al particles mass ratio is increased. The present research sheds lights on an effective evaluation of unsteady Al combustion by considering particles parameters.

Enoxaparin is an effective biological molecule for prevention and treatment of coagulation disorders. However, it is poorly absorbed in the gastrointestinal tract. In this study, we developed an Eudragit® L100 coated chitosan core shell nanoparticles for enoxaparin oral delivery (Eud/CS/Enox NPs) through a completely eco-friendly method without employing any high-energy homogenizer technique and any organic solvents. Spherical nanocarriers were successfully prepared with particle size lower than 300 nm, polydispersity index about 0.12 and zeta potential higher than +25 mV, entrapment efficiency greater than 95% and the in vitro release behavior confirms the good colloidal stability and the successful Eudragit® L100 coating process demonstrated by negligible cumulative enoxaparin release (

To investigate the morphological evolution of the whole growth and aggregation processes of hydrate crystals near the gas–liquid interface, we used a high-pressure visual reactor with high-speed camera to capture the micromorphology of hydrate particles in a natural gas + pure water system with pressure from 2.6 MPa to 3.6 MPa and sub-cooling from 4.7 to 6.23°C. The results showed that under low sub-cooling conditions, the amount and size of particles increased first and then decreased in the range of 0–330 μm, and the small particles always dominated. These particles can be roughly classified into two categories: planar flake particles and polyhedral solid particles. Then, the concept of maximum growth dominant particle size was proposed to distinguish the morphological boundary of growth and aggregation. In addition, the micro model was established to better reflect the effects of particle formation process and evolution mechanism near the gas–liquid interface under stirring condition. The results of this study can provide a guidance for flow assurance in multiphase pipeline.