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In this paper, the dispersion of Carbon nanomaterials (CNMs) in an electrolytic solution containing cations such as Ca2+, Al3+, Na+, and Mg2+ with different types of superplasticizers (Sika, Master Ease 3502, Prime DC, and Prime Flow) have been investigated. Further, the stabilized CNMs along with different superplasticizers (Sps) incorporated into the cementitious mortar and studied their mechanical strength. The influence of Sps on the stability of CNMs in an aqueous medium has been monitored by UV-Visible spectroscopy. The study concludes that Sika Sp was the best dispersant for the CNMs dispersion in an aqueous medium. The de-stability of the CNMs has followed this trend of the agglomerations in the electrolytic solution as Al3+>Ca2+>Mg2+>Na+. The Sika Sp has great dispersant properties as well as provides a homogeneous distribution of CNMs in a cementitious matrix which was supported by FE-SEM analysis. The addition of SIKA@PPC-GO (GO about 0.0015% by weight of cement) and SIKA@PPC-FCNTs (FCNTs about 0.0015% by weight of cement) results in enhancement of cement 11.67%, 8.73% for compressive and 26.35, 20.61% for tensile strength respectively, at the curing ages of 90 days. This investigation may provide advanced knowledge to predict the stability of CNMs in superplasticizer-based solutions. [ABSTRACT FROM AUTHOR]

Since solid propellants can significantly increase the mobility, load, and range of missile weapons and equipment when used as a power source, energy performance is always the primary focus of solid propulsion technology development. This paper investigated differences in the agglomeration of aluminum (Al) and characteristics of the burning surface of nitrate ester plasticized polyether (NEPE) propellants and hydroxyl-terminated polybutadiene (HTPB) propellants. The experiments were conducted under a 0.1 MPa argon gas atmosphere using a high-speed camera combined with a telephoto microscope head (macro lens). In comparison with HTPB propellants, it was discovered that the agglomeration process of Al particle of NEPE propellants had two modes. Al aggregates exit the burning surface after growing into nearly spherical agglomerates in Mode A, which is comparable to HTPB propellants. Unique to NEPE propellants, Mode B is where the Al particles aggregate into massive coral-like structures. Three factors could account for this discrepancy. First, since NEPE propellants include less ammonium perchlorate (AP), the AP is less likely to form a pocket structure. It keeps the Al particles in a large "pocket" resembling the burning surface and provides advantages for their ability to aggregate. Second, NEPE propellants have a thicker molten layer on the burning surface. It has a capillary force impact on the Al particles on the burning surface and promotes interaction between Al particles. Finally, NEPE propellants create a clear skeleton layer on the burning surface that helps Al particles stay on the burning surface. A microscopic multi-flame combustion model was created to describe the makeup of the flame of NEPE propellants. It includes the AP unit flame, the CL-20-AP flame, the Al combustion flame, and the diffusion flame of the products of decomposition of each component. In this study, the existence of molten layer and skeleton layer on the burning surface of NEPE propellants was observed for the first time in experiments. It contributes to the understanding of the unique agglomeration behavior of aluminum particles of NEPE propellants and provides theoretical guidance for the directional regulation of aluminum particle agglomeration characteristics. [ABSTRACT FROM AUTHOR]

Oncolytic Newcastle disease virus is a new type of cancer immunotherapy drug. This paper proposes a scheme for delivering oncolytic viruses using hydrogel microneedles. Gelatin methacryloyl (GelMA) was synthesized by chemical grafting, and GelMA microneedles encapsulating oncolytic Newcastle disease virus (NDV) were prepared by micro-molding and photocrosslinking. The release and expression of NDV were tested by immunofluorescence and hemagglutination experiments. The experiments proved that GelMA was successfully synthesized and had hydrogel characteristics. NDV was evenly dispersed in the allantoic fluid without agglomeration, showing a characteristic virus morphology. NDV particle size was 257.4 ± 1.4 nm, zeta potential was −13.8 ± 0.5 mV, virus titer TCID50 was 107.5/mL, and PFU was 2 × 107/mL, which had a selective killing effect on human liver cancer cells in a dose and time-dependent manner. The NDV@GelMA microneedles were arranged in an orderly cone array, with uniform height and complete needle shape. The distribution of virus-like particles was observed on the surface. GelMA microneedles could successfully penetrate 5% agarose gel and nude mouse skin. Optimal preparation conditions were freeze-drying. We successfully prepared GelMA hydrogel microneedles containing NDV, which could effectively encapsulate NDV but did not detect the release of NDV. [ABSTRACT FROM AUTHOR]

High temperature environment has many negative effects on the drilling fluid system. In order to avoid or delay these negative effects, phase change materials (PLMs) microcapsule technology was introduced into the high temperature drilling fluid system in this study to further improve the applicability of the high temperature resistant drilling fluid under extremely high temperature formation environment. The microcapsules circulate with drilling fluid, and PLMs melt endothermically at high temperature in deep formation and solidify exothermically at shallow formation. A PLMs microcapsule with solar salt (NaNO 3 : KNO 3 = 3:2) as core material and nano silica as shell material was prepared by sol-gel interfacial polymerization. The structure and properties of the microcapsules were characterized, the temperature-control performance of the microcapsule and its stability and compatibility with drilling fluid were evaluated. The results showed that the microcapsules were well encapsulated, and the single microcapsule particles were spherical, but there was a certain agglomeration phenomenon. The particle size distribution of microcapsules was concentrated in 4–16 µm, with a median particle size of 7.79 µm. The highest encapsulation rate was 60.6%, and the melting enthalpy was 68.48 J/g. The microcapsules had no obvious mass loss below 400 ℃ and had excellent thermal stability. It was proved that the microcapsules had good sealability, shear stability and cycling stability, with the enthalpy/mass retention rate all above 90%. The addition of microcapsules will not affect the basic properties of drilling fluid, and can reduce the peak temperature of high temperature drilling fluid. Different from existing researches, this paper uses a method that absorbs heat to slow down the heating rate of drilling fluid in the formation. This is a new idea, which is expected to be widely studied in the field of high temperature drilling fluids. [Display omitted] • PCM microcapsules were prepared to increase the applicability of high temperature drilling fluid. • PCM microcapsules had good morphology, suitable size, and excellent shear and cycling stability. • PCM microcapsules had good compatibility with water-based drilling fluid. • PCM microcapsules had perfect thermal stability and considerable temperature control effect. [ABSTRACT FROM AUTHOR]

The paper introduces a mathematical model based on the discrete element method, presenting the results of its application to simulate the movement of briquetted mass within the working chamber of the extruder. This model accounts for the adhesive interaction among particles within the mixture. The simulation results provide a qualitative and quantitative description of the displacement and compaction of the briquetted mass. They allow the flow structure to be visualized and the distribution of velocities and the moment on the screw axis during the extrusion process to be determined. Furthermore, a digital twin of the pug sealer–extruder unit was created through finite element modeling. The results obtained from this digital twin can be used to optimize the operational parameters of extrusion briquette equipment. In addition, by using the developed model, the process of mixing binder materials with a briquetted mixture at various volumes of the added binder was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • The harmful diamond wire saw silicon powder was leached with HCl to remove Fe. • The optimal conditions for the leaching of Fe from HCl solution were investigated. • The leaching kinetics of Fe was analyzed by heterogeneous and homogeneous model. • The Fe leaching from DWSSP fits the secondary reaction model of homogeneous model. • The work provides an important guide for preparation of high purity silicon. The diamond wire saw silicon powder (DWSSP) is considered to be a harmful to the environment because of finer particles, the large specific surface area and flammability. Removal of Fe impurity is very essential for recovering Si from DWSSP due to the large amount of Fe introduced during the silicon powder generation process. In the study, the thermodynamics of Fe leaching with HCl was analyzed and determined iron was theoretically present as ions in solution. Furthermore, the effects of different concentrations, temperatures and liquid–solid ratios on Fe leaching from HCl were investigated. The leaching rate of Fe reached 98.37% at the optimal parameters (HCl concentration of 12 wt%, leaching temperature of 333 K, liquid–solid ratio of 15 ml/g) with 100 min. The leaching kinetics of Fe in HCl was analyzed by shrinking core model and homogeneous model, respectively. The study indicated the process of leaching Fe from DWSSP conforms to the secondary reaction model of homogeneous model which coincided with the porous structure of DWSSP due to agglomeration. The apparent activation energy required (49.398 kJ/mol) in the first stage is lower than that (57.817 kJ/mol) in the second stage because of the porous structure. In conclusion, this paper provided a suitable way to purify the diamond wire saw silicon powder. This work provides an important guide for the industrial recovery and preparation of high purity silicon from DWSSP by the most environment-friendly and low-cost approach. [ABSTRACT FROM AUTHOR]

In this paper, the performance of a high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) was modeled using literature data. The paper attempted to combine different sources from the literature to find trends in the degradation mechanisms of HT-PEMFCs. The model focused on the activation and ohmic losses. The activation losses were defined as a function of both Pt agglomeration and loss of catalyst material. The simulations revealed that the loss of electrochemical active surface area (ECSA) was a major contributor to the total voltage loss. The ohmic losses were defined as a function of changes of acid doping level in time. The loss of conductivity increased significantly on a percentage basis over time, but its impact on the overall voltage degradation was fairly low. It was found that the evaporation of phosphoric acid caused the ohmic overpotential to increase, especially at temperatures above 180 °C. Therefore, higher temperatures can lead to shorter lifetimes but increase the average power output over the lifetime of the fuel cell owing to a higher performance at higher temperatures. The lifetime prognosis was also made at different operating temperatures. It was shown that while the fuel cell performance increased linearly with increasing temperature at the beginning of its life, the voltage decay rate increased exponentially with an increasing temperature. Based on an analysis of the voltage decay rate and lifetime prognosis, the operating temperature range between 160 °C and 170 °C could be said to be optimal, as there was a significant increase in performance compared to lower operating temperatures without too much penalty in terms of lifetime. [ABSTRACT FROM AUTHOR]

The gas injection parameters such as temperature, pressure and duration during the in-situ pyrolysis of oil shale are important factors that affect the pore evolution and product release characteristics of oil shale. This paper takes Huadian oil shale as a sample, uses pressurized thermogravimetry and pressurized fluidized bed experimental device to explore the influence of temperature, pressure and time on the evolution of pore structure under high-pressure nitrogen injection conditions, and analyzes the influence mechanism of pore structure evolution on the release and kinetic behavior of volatile products. The results show that in the range of 623–673 K, the effective oil recovery of oil shale pyrolysis under high pressure increases from 30.5 to 96.0% with the extension of temperature and pyrolysis time, and the average activation energy is 346.8 kJ/mol, which is higher than the activation energy of 306.6 kJ/mol under normal pressure pyrolysis. Under high pressure, the release process of volatile products is inhibited, resulting in the intensification of the secondary reaction of products and the reduction of olefin content. In addition, the primary pores of kerogen are prone to coking reaction and collapse of plastic structure, so that some large pores become microporous structure, and the average pore size and specific surface area are reduced. [ABSTRACT FROM AUTHOR]

To overcome the drawbacks of strong polarity and easy agglomeration of ordinary magnesium hydroxide (MH), hydrothermal modification is customary applied to achieve its excellent dispersion as well as controllable morphology and particle size. In this paper, the influence mechanism of hydrothermal modification is elaborated from microstructure of MH. Structures and surface energy of crystal planes, affinity of water molecules for crystal planes, and crystal growth process are calculated by Materials Studio software. Furthermore, molecular dynamics simulations about solid–liquid interface model of MH and 1 mol L−1 NaOH solution at different temperatures are performed based on the theory of modified attachment energy model. The results indicate that (0 0 1) plane with the smallest surface energy has the strongest thermodynamic stability, equipping modified crystals with lamellar morphology and excellent dispersion. (0 0 1) plane cannot be dissolved easily because of the smallest affinity of water molecules. The magnesium atoms and hydroxyl groups on (1 0 1) plane dissolved are absorbed on (0 0 1) plane, resulting in the large value of I001/I101 in the X‐ray diffraction pattern. The relative growth rate of (1 0 1) plane R101 decreases with the increasing temperature, explaining why crystals become thicker with raising temperature. [ABSTRACT FROM AUTHOR]

This work presents a novel approach for the growth of potassium sulfate (K2SO4) from supersaturated solutions by reaction-extractive crystallization in a fluidized-bed crystallizer (FBC), in which K2SO4 is transformed into potassium chloride and sulfuric acid based on a reactive extraction-crystallization process using triisooctylamine (TOA) in n-octanol as the extraction system. This paper uses the moment transformation method to solve the population balance equations of K2SO4 in the extractive crystallization process, and the crystallization kinetic parameters are obtained by nonlinear regression. The kinetic equations of crystal nucleation, growth, and agglomeration rate in the crystallization process of potassium sulfate are determined, and experiments verify the reliability of the kinetic parameters. The results show that in a specific range, higher supersaturation and fluidization rate are conducive to the nucleation, growth, and aggregation of K2SO4. Suspension density promotes crystal nucleation and growth but has the opposite effect on accumulation. At the same time, based on the constant calculation equation of particle number and the constant calculation equation of mass, the extraction crystallization coupling mathematical model of the crystal in the fluidization state is established. The effects of suspension density, Reynolds number, extraction rate, feeding rate, and extraction concentration on potassium sulfate's nucleation, growth, and aggregation rate were studied by combining model calculation with experimental research. A process coupling model of the potassium sulfate extraction crystallization process in a fluidized bed was proposed. The model agrees with the experimental results, which have specific guiding significance for industrial production. [ABSTRACT FROM AUTHOR]

The nano-sized metal oxides (MOs) as combustion catalysts have been widely employed in solid rocket propellants, but the functionality of these materials is greatly restricted owing to their agglomeration. The catalytic activity of MOs on nanoscale was found to be significantly improved by the incorporation of MOs with carbon nanomaterials, which normally act as carriers allowing for well-distribution of MOs. In this paper, the CuO and Fe2O3 nanoparticles were produced by hydrothermal method and the CuO@C and Fe2O3@C nanocomposites with a uniform structure have been fabricated by an in-situ growth of corresponding MOs on the porous activated carbon (pAC). The morphology of the prepared MOs nanoparticles and resultant pAC carried ones were characterized using scanning electron microscope. It has been shown that the CuO and Fe2O3 nanoparticles are tightly adhered and dispersed on the surface of pAC. Their catalytic effects on the thermal decomposition of hexogen (RDX) were analyzed using thermal analysis techniques. Results indicate that the thermal decomposition of RDX was considerably promoted in the presence of these catalysts, where the CuO@C and Fe2O3@C were found to be capable of lowering the Tp for RDX by 14.8 °C and 12.4 °C, respectively. In addition, the decomposition kinetics of RDX in the presence of these catalysts have been evaluated with the DTG and DSC experimental data, and results show that the CuO@C and Fe2O3@C were able to reduce the Ea of RDX decomposition by 39.8 kJ mol−1 and 50.7 kJ mol−1, which is suggestive of an enhanced decomposition process for RDX by addition of carbon-loaded catalysts. The TG-FTIR analysis indicates that, in the presence of CuO@C and Fe2O3@C, the gaseous products are dominated by N2O in RDX decomposition. [ABSTRACT FROM AUTHOR]

CaCO 3 /CaO thermochemical energy storage (TCES) system has a high heat storage density (1780 kJ/kg) along with high heat storage and release temperature (650–850 °C), which can be applied to concentrated solar power (CSP) technology utilizing CO 2 Brayton cycles to improve power generation efficiency. There are several problems to be urgently resolved in current CaCO 3 /CaO solar calciners, such as poor heat and mass transfer and low thermochemical efficiency. This paper proposed a prototype CaCO 3 /CaO TCES system based on a novel fluidized bed solar reactor, which has a serrated arc surface in alignment with the direction of the incident solar rays to receive concentrated solar energy. The natural limestone particles were used as the reactive particles. The effects of operating modes (intermittent/continuous), initial mass of reactive particles, and initial carbonation temperature T c a r , i n i t i a l on the heat storage and release characteristics of the TCES system were experimentally explored. During the carbonation reaction stage, the effective carbonation degrees in the continuous mode were generally higher than in the intermittent mode under the experimental conditions and declined at a slower rate. The reactive particles were recovered from the reactor for microstructural characterization after completing the experiments, high-temperature particle agglomeration and pore structure clogging were directly responsible for the decrease of the effective carbonation degree. In the continuous mode, the average thermochemical and total thermal efficiencies of 24.7 % and 53.5 % were obtained in the 1st calcination reaction, respectively, which represents significant advantages over other CaCO 3 /CaO solar calciners. The novel fluidized bed reactor demonstrated excellent fluidization in the experiments and did not exhibit mechanical deformation after multiple experiments under non-uniform concentrated radiation provided by an 84 kW e high-flux solar simulator. Overall, this paper provides a successful gas-solid reactor design to be coupled with CSP technology. • A prototype CaCO 3 /CaO thermochemical energy storage system was established. • The reactor showed superior fluidization performance and deformation resistance. • The influencing factors of heat storage and release characteristics were studied. • Favorable thermochemical and total thermal efficiencies were obtained. [ABSTRACT FROM AUTHOR]

In this paper, we report Tin Selenide (SnSe) nanoparticles preparation through co-precipitation method and characterised by UV–Vis spectroscopy, scanning electron microscopy, Fourier transforms infrared spectroscopy, X-ray diffraction, EDX spectrum, photovoltaic and Supercapacitor performance. XRD patterns indicate that the prepared SnSe nanoparticles exist in the orthorhombic phase. The SEM and TEM image show that nanoparticles exhibit spherical shapes with high agglomeration. The UV-Visible spectrum recorded in the range of 200–800 nm, show peaks at 260 nm, 300 nm, and 350 nm while direct energy bandgap lies between 1.4 eV and 1.8 eV and indirect energy bandgap lies between 1.5 eV to 1.6 eV. The obtained SnSe counter electrodes (CEs) showed good electrocatalytic activity in the redox reaction of the I−/I3−. The Dye-sensitised solar cells (DSSC) of SnSe with molar ratios (1:1), (2:1), and (3:1) as showed good photovoltaic performances in comparison to platinium (Pt) counter electrode (CE). The higher specific capacitance value 1335 F/g of SnSe (3:1) electrode compare to the SnSe (1:1) and (1:2) electrodes proves the stability of SnSe (3:1) for supercapacitor performance. [ABSTRACT FROM AUTHOR]

Different current reasons, like global warming due to greenhouse gases and high energy prices, creates the necessity to make the heating systems in large cities more efficient. The present paper presents a real situation for an urban agglomeration, regarding the transition from a centralized heating system to a decentralized one. Two types of decentralized possibilities are discussed and analyzed taking into account especially the CO2 emissions, during several recent years. In this respect, a calculus of CO2 emissions from the former heating system, compared to the present heating systems is also presented and discussed. [ABSTRACT FROM AUTHOR]

In this paper, we have successfully prepared MnNi 2 O 4 micro/nano multiporous spheres via a subsequent simple impregnation and calcination. Lithium storage performance of the as-prepared MnNi 2 O 4 has been firstly investigated, with a stable capacity of 669.2 mAh g−1 after 70 cycles at 1.0 A g−1. Cyclic voltammograms data indicate that discharge-charge process is synergistically controlled by both the dominate diffusion and the secondary capacitive behavior. Electrochemical impedance spectroscopy evidences low resistance and high Li+ diffusion coefficient (3.4 × 10−15 cm2 s−1). Furthermore, an excellent supercapacitor behavior is also achieved. All that can be benefited from the unique micro/nano multiporous structures which can effectively facilitate electrolyte penetration and diffusion of tiny particles, alleviate the volume swelling and the electrochemical agglomeration, suggesting a prospective application in energy storage devices. • A novel route was designed to prepare MnNi 2 O 4 micro/nano multiporous spheres. • Lithium storage performance of the as-prepared sample were firstly investigated. • A capacitance with about 2344.1 F g−1 was achieved after 4000 cycles at 1.0 A g−1. [ABSTRACT FROM AUTHOR]

In the present paper, a new approach for detonation nanodiamond (DND) deagglomeration is proposed. DND agglomerates of the size from 20 to 200 nm have been exposed to wet sonication assisted oxidative treatment with ozone under UV irradiation (Advanced Oxidation Process). Subsequent sonication and centrifugation gave a stable hydrosol of individual DND particles with negative zeta potential of −65 mV. The yield of the desired 4–5 nm fraction reached 33 wt%. Powder X-Ray Diffraction study showed no signs of DND crystalline core degradation, while the surface of particles was enriched significantly with carboxyl functional groups according to the data of Diffuse Reflectance Infrared Fourier Transform Spectroscopy, that gave boost to the stability of DND hydrosol. The approach provides relatively high yield of deagglomerated detonation nanodiamond without impact of high temperatures on the DND particles. It also allows avoiding gas phase processes sticking to wet-chemistry that could be useful for process scalability. [ABSTRACT FROM AUTHOR]

To investigate the effect of surfactants in compound solution on the wetting-agglomeration properties of the bituminous coal dust, this paper selected anionic surfactants SDS, SDBS and non-ionic surfactants APG0810 and PPG400 for compounding with agglomerated solutions 0.05 wt% XTG (xanthan gum). The sink test, surface tension test, viscosity test, fourier transform infrared spectroscopy(FTIR) and scanning electron microscope(SEM) were used to investigate the wettability and agglomeration of the four compound solutions and analyze the agglomeration wetting mechanism. The results show that SDBS has the most obvious improvement in the wettability of compound solution. The surface tension of SDBS + 0.05 wt% XTG is 28.98 mN/m after CMC value and sinking rate will reach 14.29 mg/s with 0.6 wt% SDBS in compound solution; Furthermore, FTIR results showed that surface hydroxyl content of bituminous coal dust treated by 0.2 wt% SDBS + 0.05 wt% XTG solutions has increased 26.3% than that treated by 0.05 wt% XTG, which promoted the adsorption of xanthan gum molecules on the coal surface. The presence of surfactants decreases the viscosity and surface tension of compound solution, and xanthan gum–surfactants interaction will promote bituminous coal dust agglomeration effect. This agglomeration mechanism is mainly reflected in the distribution mechanism and bituminous coal dust can form to large agglomerates under this action. [Display omitted] • Influence mechanism of surfactants in compound solution on viscosity is analyzed. • Wetting-agglomeration properties of coal dust by composite reagent are studied. • The distribution mechanism about coal dust agglomeration has been found. • The formed process of distribution mechanism has been described. [ABSTRACT FROM AUTHOR]

In this paper, the instability of a vertical fluid motion, or throughflow, is investigated in a horizontal bidisperse porous layer that is uniformly heated from below. By means of the order-1 Galerkin approximation method, the critical Darcy–Rayleigh number for the onset of steady instability is determined in closed form. The coincidence between the linear instability threshold and the global nonlinear stability threshold, in the energy norm, is shown. [ABSTRACT FROM AUTHOR]

With continuous expansion of the heat produced from biomass energy, the problems of biomass ash melting and slagging have become increasingly prominent. Studies of mineral transformations and melting behaviour in biomass ash are helpful for understanding the slagging process fully. In this paper, ash samples prepared from corn straw, sawdust and rice husk were studied with an ash melting point analyser, simultaneous thermal analyser, XRD and SEM‒EDS. The results showed that the deformation temperature (DT) of corn straw was the lowest, while that of rice husk was the highest. The variations in ash weight loss and temperatures indicated that the two main paths for ash loss were decomposition and volatilization. With increasing combustion temperature, eutectic salts with low melting points were formed in the ash, such as potassium silicate and calcium silicate, and the liquid phase and crystalline phase coexisted at 1000 °C. In this paper, the influence of different elements on the ash structure and the changes occurring in ash structure during combustion and ash melting point tests are explained by considering the silicate network structure. The ash melting behaviour observed during biomass combustion is clarified, which provides a theoretical basis for preventing biomass ash from melting and slagging. [Display omitted] [ABSTRACT FROM AUTHOR]

The combustion efficiency of Al is usually not high due to the influence of alumina film and agglomeration. Therefore, finding ways to enhance the ignition and combustion performance of Al is important. Herein, a simple one-step recrystallization method was used to prepare the Al@ citric acid (CA) sample. The results showed that the one-step recrystallization method could well coat CA on the outer surface of Al particles and could etch Al particles uniformly. After modification by CA, Al was more prone to thermal oxidation. Compared with pure Al, the addition of CA resulted in shorter ignition delay time, longer combustion time, increased combustion intensity, and weakened agglomeration degree. Condensed combustion products (CCPs) showed that Al sintered significantly during combustion, forming a large agglomerate. The CCPs of Al@CA were more dispersed and had many hollow shell particles. Furthermore, the addition of CA led to a decrease in the active Al content and an increase in the α-Al 2 O 3 content in CCPs. The above phenomena indicated that CA could significantly improve the combustion efficiency of Al. At last, the possible mechanism of CA promoting the ignition and combustion of Al was proposed. Overall, the enhancement of Al combustion performance by CA is attributed to the etching and coating effects of CA. Hoping that this paper will provide a possible pathway for exploring ways to improve Al combustion efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

• Glass-ceramic sealed solid oxide fuel cells (SOFC): agglomeration effect of Rare-earth oxide. • Rare-earth oxide addition leads to depolymerization of the glass network structure. • The addition of La 2 O 3 to the sealing glass effectively improves viscosity and resistivity. In this paper, the agglomeration effect of rare-earth oxide has been confirmed through that the thermal properties, viscosity, crystalline phase, and high temperature resistivity of the 35BaO-(15-x)CaO-5Al 2 O 3 –10B 2 O 3 –35SiO 2 -xLa 2 O 3 (x = 1, 3, 5, 7, 9 mol%, BABSCLa) glass system were systematically investigated. With the increase of the La 2 O 3 /CaO molar ratio, the results of Raman and infrared spectra of the BABSCLa glass showed that the Q4, Q3, and Q2 units of [SiO 4 ] decrease, while Q1 and Q0 units increased in the BABSCLa glass structure, because the La 2 O 3 as the glass network modifier can create more non-bridging oxygen than the CaO. However, the "agglomeration" effect of La ions with the high field strength could adsorb the oxygen in glass to form the La–O–La (Si) bond, resulting that the glass transition temperature and softening temperature of the BABSCLa glass continued to increase with the addition of La 2 O 3 , and the coefficient of thermal expansion (CTE) of annealed glass decreased from 11.37 to 10.87 × 10–6K–1, respectively. Simultaneously, the main crystalline phase of the BABSCLa glass-ceramic gradually changed from the low crystallization activation energy BaSiO 3 phase with 287 kJ/mol to Ba 3 La 6 (SiO 4) 6 phase with 454 kJ/mol duo to the "agglomeration" effect of La ions. The CTE of the BABSCLa glass-ceramic increased from 12.35 to 13.05 × 10–6K–1 and then decreased to 11.75 × 10–6K–1. The direct-current (DC) resistivity of the BABSCLa glass-ceramic was higher 105 Ω•cm at a high temperature of 750 °C, which had good high-temperature electrical insulation. This demonstrated the La 2 O 3 strengthening BaO CaO-Al 2 O 3 -B 2 O 3 -SiO 2 glass-ceramic system was an effective method for the preparation of hermetic glasses. [ABSTRACT FROM AUTHOR]

As shown in the diagram, we developed Co(OH) 2 -MoO 3 /NF with petal-like layered nanosheet structure as a novel and efficient OER catalyst. Notably, Co(OH) 2 -MoO 3 /NF nanosheets not only prevent the agglomeration of nanostructured material, but also facilitate the complete penetration and diffusion of electrolyte. In addition, Co(OH) 2 -MoO 3 /NF exhibits excellent electrocatalytic OER performance. [Display omitted] • Petal-like layered nanosheet structure. • Excellent electrocatalytic OER performance. • The strong electronic interaction between Co(OH) 2 and MoO 3. The development of high-performance and cost-effective electrocatalysts for oxygen evolution reactions (OER) is key to renewable energy conversion and storage technologies. In this paper, a hierarchical Co(OH) 2 -MoO 3 nanosheets with petal-like architecture was prepared by a simple one-step hydrothermal method using ZIF-67/NF as a precursor, and it was used as a direct electrocatalyst for OER. Notably, this petal-like Co(OH) 2 -MoO 3 /NF layered nanosheets not only prevent the agglomeration of nanostructured material, but also facilitate the complete penetration and diffusion of electrolyte. In addition, due to the strong electronic interaction between Co(OH) 2 and MoO 3 in the Co(OH) 2 -MoO 3 /NF system, Co(OH) 2 -MoO 3 /NF exhibits excellent electrocatalytic OER performance. It has a low overpotential of 273 mV at 10 mA cm−2 and excellent stability. This study provides a simple and effective strategy for the rational design and structural evolution of MOF-derived materials to achieve inexpensive and effective electrocatalysis. [ABSTRACT FROM AUTHOR]

• FS-50 is more effective in suppressing bituminous coal dust than FS-3100. • FS-50 achieves more efficient wettability and agglomeration than FS-3100. • FS-3100 achieved higher diffusion coefficient and lesser absolute wetting area. • The electrostatic potential energy and hydrogen bonds are key influencing factors. • The higher LUMO value and band gap energy deteriorates the performance of FS-3100. This paper carried out a multi-scale investigation on the wetting and agglomerating mechanism of short-chain fluorocarbon surfactant suppressing coal dust. As investigated, FS-50 achieves higher dedusting rate and shorter suppression time than FS-3100, which is attributed to its better wettability and more sufficient agglomeration on coal particles. Simulation indicates that FS-3100 with longer chain length is easier to generate chemical bond rotation, which results in a distorted spatial structure, higher steric hindrance, and poorer ability of FS-3100 in retaining H 2 O molecules and adsorbing surround the coal particles. The hydrophilic group of FS-50 is dominated by the induced effect and presenting larger charge density and electron-absorbing nature. Higher electrostatic potential difference with coal molecules, more hydrogen bonds, shorter bond length and larger bond angle are key factors to endorse FS-50 a better wetting and agglomerating performance. The C atom connected with the fluorocarbon tail chain of FS-3100 is linked to a carboxyl group with lone pair electrons. This carboxyl group enlarges the LUMO value of FS-3100 and weaken its ability to attract the electrons of coal particles. On the contrary, the lower LUMO value, lower band gap energy, and smoother spatial configuration jointly bring FS-50 better wetting and agglomerating ability. [ABSTRACT FROM AUTHOR]

Metal ions have been used to improve the flotation recovery of muscovite, while the enhancement mechanism is still unclear. In this paper, density functional theory (DFT) calculations and molecular dynamics (MD) simulations were employed to investigate the adsorption structure of sodium oleate (NaOL) on muscovite surface, and the diffusivity and foaming of NaOL in the pulp system, in presence of Fe3+ at different pH range. DFT calculation results suggested that the adsorption of iron ions, include FeOH2+ and Fe(OH) 2 +, could change the surface charge from negative to positive, thus enhancing binding performance for OL−. Moreover, MD simulations indicated that the distribution of iron ions in aqueous solution can significantly affect the dispersion of sodium oleate molecules. Specifically, FeOH2+ may lead to the complexation of oleate ions and result in the agglomeration, which is not conducive to its dispersion in solution. However, Fe(OH) 2 + can significantly inhibit the aggregation of OL− molecules, and accelerate the dispersion of OL− in flotation pulp. This work reveals atomic-level mechanism of Fe ion on the dispersion and adsorption of sodium oleate in pulp, which is helpful to the understanding of minerals flotation behavior in presence of metal ions. [Display omitted] • The mechanism of Fe3+ on muscovite flotation was explored by DFT and MD calculations. • Fe3+ ions could change muscovite surface charge and enhance adsorption of OL-. • Fe3+ ions could affect the dispersion behavior of OL- in flotation pulp. [ABSTRACT FROM AUTHOR]

[Display omitted] • Al 2 O 3 was first prepared at different temperatures of 900, 1000, and 1100 °C. • Spherical-shaped Al 2 O 3 /CuO nanocomposite was prepared at 1000 °C. • Hexagonal (Al 2 O 3) and monoclinic (CuO) crystal structures were established. • A photocatalytic degradation study was conducted using MO as a model pollutant. • About 94 % efficiency was achieved within 3 h using optimum operating conditions. Aluminum oxide (Al 2 O 3) and copper oxide (CuO) are known to exhibit very exceptional properties including high thermal and chemical properties that promise a wide area of applications. In this paper, we report the microwave-assisted thermal decomposition route to CuO/Al 2 O 3 nanocomposite and its application as a photocatalyst for methyl orange (MO) degradation. Al 2 O 3 was first prepared at different temperatures of 900, 1000, and 1100 °C, denoted as Al 2 O 3 (1), Al 2 O 3 (2), and Al 2 O 3 (3). Subsequently, the best temperature (1000 °C) was selected for the synthesis of CuO/Al 2 O 3 nanocomposite. XRD analysis confirmed the hexagonal crystal structure for all the Al 2 O 3 and the monoclinic phase for the CuO within the composite. The crystallite sizes of the alumina increased with temperature and a similar growth pattern occurred in the entire samples. Scanning electron microscopy and transmission electron microscopy (SEM and TEM) show clear spherical morphology for all the samples with obvious agglomeration as temperature increases. Optical characterization displayed decreasing band gap energies with increasing temperature, implying size increase due to particle interaction, boundary energy reduction, and grain boundary migration. The photocatalytic performance of the CuO/Al 2 O 3 under visible light was evaluated on methyl orange (MO), and the degradation was studied with some process parameters such as the effect of catalysts dosage and initial concentration of MO. Results showed that the CuO/Al 2 O 3 exhibited about 94.2 % efficiency within 3 h using an optimum dose of 2.0 g/L and an initial MO concentration of 20 mg/L. However, the use of CuO/Al 2 O 3 nanocomposites to remove other organic pollutants could confirm the robustness of this catalyst. [ABSTRACT FROM AUTHOR]

• Agglomeration of Ca(OH) 2 is quantitatively studied by reactive molecular dynamics. • Agglomeration inhibition of SiO 2 is studied by reactive molecular dynamics. • Doping SiO 2 changed the diffusion mechanism of the agglomeration of Ca(OH) 2. • The decline in the external potential energy drives the agglomeration. • Doping SiO 2 will increase the van der Waals force and obtain a stable structure. As a promising thermochemical heat storage material, the Ca(OH) 2 /CaO can be agglomerated after repeated heat storage cycles, which will affect its performance severely. Experimental evidence indicated that the dopant of SiO 2 particles alleviated the agglomeration phenomenon of Ca(OH) 2 /CaO. However, the mechanisms have not been clarified in theory, including the agglomeration of Ca(OH) 2 /CaO and the agglomeration inhibition of SiO 2. Investigating these mechanisms is important for the broad application of Ca(OH) 2 /CaO thermochemical heat storage technology. In this paper, reactive molecular dynamics is employed to simulate and quantify the agglomeration of Ca(OH) 2 and the inhibition by SiO 2 during the heat storage process. Then, the agglomeration phenomena under the two processes are quantitatively described. The mechanisms are analyzed by using the parameters of kinetics and thermodynamics. From the phenomenological analysis, smaller size changes, larger mass center distances, and smaller atomic displacements indicate that SiO 2 doping reduces the tendency of nanoparticles to agglomerate into a larger cluster. From the kinetic perspective, the diffusion of pure Ca(OH) 2 clusters conforms to viscous flow, while the diffusion of the SiO 2 -doped clusters is close to surface diffusion. The dopant of SiO 2 increases the activation energy of the diffusion process, which would increase the atomic mobility resistance and thus inhibit the agglomeration. From the thermodynamic perspective, cluster agglomeration is mainly caused by the work done by van der Waals forces, which leads to a decrease in potential energy, especially surface potential energy. By doping SiO 2 , the interatomic van der Waals forces are increased, which lowers the stable potential energy surface of the clusters, thereby obtaining a more stable structure to inhibit agglomeration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ammonia diffusion combustion in fluidized bed is studied by experiment and simulation. • Ammonia burns at bubble injection, which is oxidized as bubble rising, finally burns in freeboard. • The mass transfer coefficient between bubble phase and emulsion phase is studied. • The contribution of different elementary reactions to oxygen consumption is compared. • The effects of gas velocity, bed temperature and oxygen concentration of fluidizing gas are investigated. Fluidized bed is a potential equipment for NH 3 combustion due to its efficient gas–solid contact and high temperature particles as heat source for ignition. This paper studies the diffusion combustion of NH 3 in a single bubble of fluidized bed, using an experimental approach and CFD-DEM simulation incorporated with a skeleton mechanism of 98 elementary reactions. The results show that the diffusion combustion of NH 3 intermittently occurs in the bubble injection period and the oxygen is mainly consumed by H + O 2 = OH + O. Slow oxidation, instead of combustion, takes place in the bubble rising period and the oxygen is mainly consumed by NNH + O 2 = N 2 + HO 2. With the rupture of the bubble, unreacted NH 3 re-burns, generating flames in the freeboard of the bed. The chemical reaction in the bubble is highly correlated to the mass transfer between the emulsion phase and bubble phase. Increasing the fluidization gas velocity promotes the accumulation of oxygen and enhances the reaction rate of slow oxidation of NH 3 in the bubble due to the increasing inter-phase mass transfer. The increase of the bed temperature reduces the ignition delay time, and increases the chemical reaction rate and mass transfer coefficient. The changes in oxygen concentration of fluidizing gas not only changes the chemical reaction rate, but also affects the oxygen consumption path. The fraction of NH 3 oxidized in the dense bed can be enhanced by increasing the fluidization gas velocity, bed temperature and oxygen concentration of the fluidizing gas, the latter exerting the greatest influence. [ABSTRACT FROM AUTHOR]

The hydrodynamics of flotation machines can significantly impact the flotation performance of fine minerals, however, those of fluidized bed flotation columns with binary particles remain poorly understood. This paper investigated the hydrodynamics of fluidized bed flotation columns such as bed pressure drop, minimum fluidization velocity, bed expansion ratio, and gas holdup. The effect of liquid velocity, gas velocity, and particle size on hydrodynamics was discussed. The hydrodynamics of fluidized beds with binary particles was compared with that of unitary particles. Results showed that the hydrodynamics of the fluidized bed with binary particles lay between the fluidized bed with large and small particles as influenced by the combination of large and small particles. A fluidized bed flotation column with binary particles demonstrates great potential in changing hydrodynamics. [Display omitted] • An investigation of the fluidization process in a fluidized bed with binary particles. • The gas holdup in the freeboard zone and the fluidized zone was studied. • Gas introduction facilitates fluidized bed formation. • The hydrodynamics of the bed are affected by both small and large particles. • Binary particles can aid in regulating the hydrodynamics of the bed. [ABSTRACT FROM AUTHOR]

• Utilizing lime mud as a filler can lead to the production of high-strength materials. • Lime mud can enhance material hydration by creating more nucleation sites. • The use of lime mud can refine pores and decrease pore structure. • Lime mud can be used in large replacement ratios, which can improve the sustainability of the mixture. Lime mud (LM) is a solid industrial byproduct with high alkalinity and calcium carbonate (CaCO 3) content produced by the paper industry. LM has been used and investigated as a supplementary cementitious material (SCM). However, using LM with a high replacement ratio causes agglomeration, which reduces the material's strength and has a detrimental effect on other properties. In addition to agglomeration, LM is unreactive; thus, in this work, a high replacement ratio (70%) of sand with raw LM was investigated in a mortar mixture containing silica fume (SF), considering the fast SF hydration properties of cement in a high alkaline environment, and river sand is used to reduce the agglomeration of LM. The effects of the replacement were then evaluated using compressive strength, X-ray diffraction, thermogravimetric analysis, mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM). The hydration kinetics were investigated using isothermal calorimetry. The experimental results showed that combining SF with a high replacement ratio (70%) of LM improves compressive strength and flexural strength by 16% and 59.7%, respectively. This is due to the filler nature of LM, which refines the pore structure. Furthermore, the highly alkaline environment provided by LM increased the secondary hydration of SF with cement, which also improved the strength. [ABSTRACT FROM AUTHOR]

[Display omitted] • The surface of SrTiO 3 powders were successfully coated by silane coupling agent (vinyltrimethoxysilane, VTMS). • SrTiO 3 /PB composite exhibits a high dielectric constant of 21.1 and small loss tangent of 0.0041. • The composites possess great thermal conductivity and high bending strength. • Pores in composites and agglomeration of ceramic particles lead to the deteriorate of dielectric and thermal properties. In this study, vinyltrimethoxysilane (VTMS) treated SrTiO 3 particles were composited with polybutadiene (PB) using doctor blade and hot-pressing approaches (xSrTiO 3 @VTMS/PB, x = 84–90 wt%) to satisfy the application in microwave band. The effects of SrTiO 3 doping on the microstructure and dielectric properties were investigated detailly. Thermal and mechanical properties of the composite were also discussed in this paper. When x = 87.5 wt%, SrTiO 3 @VTMS/PB reached the best dielectric properties of highest dielectric constant (ε r ∼ 21.1) with low dielectric loss (tanδ ∼ 4.1 × 10−3) at 10 GHz. A great thermal conductivity of 1.363 W/(m·K) at room temperature and high bending strength of 55.2 MPa could be achieved at 86 wt% filler loading. This study can provide a promising composite for microwave applications. [ABSTRACT FROM AUTHOR]

• A comprehensive isomerization network of C 8 aromatics including disproportionation and deethylation reactions is proposed. • A set of reaction rates for the above network are established to suit pure o-xylene, pure m-xylene and industrial feeds. • An appropriate operating condition is determined to heighten the productivity of p-xylene. Isomerization of C 8 aromatics is an indispensable process for industrial production of p-xylene, but there is still a lack of rigorous kinetics of this reacting system. In this paper, the experiments for isomerization of C 8 aromatics over Pt/HZSM-5 have been carried out in an isothermal fixed bed reactor under a wide range of operating conditions to obtain the rate laws for isomerization, disproportionation and deethylation reactions. A detailed kinetic model is developed from experimental data to accurately describe the reacting system of C 8 aromatics, and the apparent kinetic parameters are estimated by genetic algorithm and least square method. The kinetic model verified by fitting experimental data can well predict the reaction trends of o-xylene, m-xylene and industrial feeds to exhibit good feed adaptability. Therefore, this model will support reactor design and operation. [ABSTRACT FROM AUTHOR]

Biomass can effectively modify coal ash fusibility and alleviate several operational issues like agglomeration, sintering, and erosion for slagging gasifiers. The key issue is to clarify the ash fusion properties and mineral transformation during the heating process. The fusion temperatures, mineral evolutions, in-situ morphology observation and thermodynamic analysis of the coal, biomass and biomass-coal blended ash samples were systematically evaluated in this paper. The ash fusion temperatures (AFTs) presented V-type curves with the increasing rape straw ratio. Then the bottom point occurred at the ratio of 50 wt% due to the reduction of refractory minerals (mullite, quartz, < 50 wt%; kalsilite, oldhamite, >50 wt%) and the increase of low-melting-point minerals and their eutectics (leucite and anorthite). Besides, the thermodynamic calculation can provide the basis for the prediction of ash fusion behavior. The in-situ morphology evolutions of blended ashes further revealed the relationship between ash fusion behaviors and morphological changes. Namely, the terminative sintering and melting temperature were highly related to the ash deformation temperature and flow temperature, R2 was 0.9901 and 0.9846, respectively. The significant work could guide the mixing conditions during the co-gasification of high‑silicon‑aluminum coal and biomass and improve the ash fusion properties. • Ash fusion temperature reached the minimum as RS addition was 50 wt%. • Low-melting-point minerals and their eutectics formation led to lower AFTs. • The thermodynamic calculation was used to predict ash fusion behavior. • In-situ observations were conducted to explore the melting mechanism. • A correlation between AFTs and HTSM characteristic temperatures was explored. [ABSTRACT FROM AUTHOR]

• Spiral coil reactor is proposed based on combination of pneumatic transmission and secondary flow. • Flow behavior, energy charging and discharging is investigated by experimental methods. • CaCO 3 conversion is around 2–5% during energy charging experiments. • CaO conversion is approximately 60–68% during energy discharging experiments. • The flow rate and reaction temperature have large effects on the CaO conversion. Simultaneously offering sufficient heat and mass transfer is a significant challenge for the reactor design in the field of thermochemical energy storage owing to either a low thermal conductivity or a low permeability of the solid reactants. This paper proposes a spiral coil reactor based on combination of pneumatic transmission and secondary flow for thermochemical energy storage. The CaCO 3 /CaO is selected as reaction medium. The gas-solid flow behavior, energy charging and discharging are investigated by the experimental methods. The results show that CaCO 3 conversion is around 2–5% during the energy charging experiments and CaO conversion is around 60–68% during the energy discharging experiments. The CaO conversion is a little higher than that in the fluidized bed under the same condition. Both the unstable gas velocity and the fluctuation of pressure drop in the spiral coil reactor due to particles agglomeration and sintering at high charging reaction temperature account for the low CaCO 3 conversion. In addition, the energy discharging experiments also indicate that the flow rate and reaction temperature have large effects on the CaO conversion. An increase in the gas velocity relieves CaO sintering, consequently resulting in a higher CaO conversion. Moreover, the reaction rate can be improved at higher energy discharging temperature which leads to enough residence time and higher CaO conversion. Overall, this paper provides a novel insight for gas-solid reactor design in the field of thermochemical energy storage. [ABSTRACT FROM AUTHOR]

In order to elevate the high voltage resistance and stability of LiCoO 2 cathodes, its application potentialis further excavated. In this paper, the functionalization of nano SiO 2 (PDA@SiO 2) was realized by using the self polymerization coating characteristics of dopamine. Its functionalization with the fumed SiO 2 nano-particle center allows even 2% PDA@SiO 2 to be uniformly coated onto a LiCoO 2 cathode via rotary steaming. It is demonstrated by scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS) that the functional nano-coating is distributed homogeneously on the surface of LiCoO 2 particles. The close interaction between nano PDA@SiO 2 coating and LiCoO 2 particles is emerged, which avoids the agglomeration of nano SiO 2 and enhances the function of solid superacid formed by fumed SiO 2. The X-ray photoelectron spectroscopy (XPS) shows that less undesired side products are deposited on the surface of LiCoO 2 , and X-ray diffraction (XRD) and SEM indicate that the lattice expansion and irreversible phase transformation of crystal structure are effectively inhibited. The interface stability and ionic conductivity of LiCoO 2 cathodes at high voltage are elevated substantially. Thus, the cycle stability of LiCoO 2 cathodes during charge and discharge at 4.6 V high voltage is significantly improved. At room temperature, the modified LiCoO 2 cathode with functionalized nano-SiO 2 achieved a reversible capacity of around 190 mAh g−1 with the capacity retention of 78% after 200 cycles at 1C, along with a relatively high cyclability of 68% capacity retention after 100 cycles at 1C and 50°C. [ABSTRACT FROM AUTHOR]

• Ultrasound was introduced to the crystallization process of Citicoline sodium. • Ultrasound can affect metastable zone widths and induction time. • The fouling of crystals on the crystallizer was mitigated by ultrasound. • Particle size distribution and crystal habit were improved by ultrasound. Citicoline sodium tend to agglomerate during the crystallization process which can't be well solved by changing some conventional crystallization conditions. To solve this problem, an ultrasonic-assisted crystallization method was developed in this paper. The effects of ultrasound on the crystal metastable zone widths (MSZWs), induction time, crystal habit, and particle size distribution (PSD) were studied experimentally. The dynamic method was used to determine the solubility of Citicoline sodium in ethanol–water binary mixed solvents. The induction time and the MSZWs were measured under ultrasound and silent conditions. Moreover, the crystallization process was optimized using ultrasonic-assisted anti-solvent crystallization method. The influence of ultrasound on crystal habit during the crystallization process could be observed by optical microscope. Ultrasound optimized products can be characterized by scanning electron microscope (SEM), laser particle size analyzer, X-ray powder diffraction and infrared spectroscopy. The experimental results showed that the MSZWs and the induction time could be reduced by the application of ultrasonic irradiation. The agglomeration and crystal habit of Citicoline sodium could be improved by optimizing the crystallization process with ultrasound. After optimization, the mass yield was increased to 95 %, the median particle size D V (50) was about 10 μm and the PSD was narrower. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mo promoter effect on restraining agglomeration of Ni in ESR is investigated. • SiO 2 morphology effect on improving the coking resistance of Ni is studied. • SBA-15 improves resistances of Ni particle sintering and coking in ESR. • NiMo catalysts on SBA-15 shows excellent ESR performances at 600 °C over 65 h. This paper investigates the effects of molybdenum promoter and silica oxide (SiO 2) support morphology on the ethanol steam reforming (ESR) performance of Nickel-Molybdenum (NiMo) bimetallic catalysts. Ordered mesoporous SiO 2 (SBA-15) and commercial SiO 2 supports were used as the oxide support materials. The synthesized catalysts were prepared via the wet impregnation method and characterized via XRD, H 2 -TPR, BET, FTIR, and Raman techniques. This study shows that NiMo bimetallic catalyst supported on SBA-15 has superior catalytic activity and better coking resistance at an intermediate temperature of 600 °C than commercial SiO 2 supported catalysts. The presence of a uniform mesoporous structure of SBA-15 with an average pore diameter of ∼ 2 nm can obstruct the carbon formation, leading to improved coking resistance. The catalytic enhancement of NiMo bimetallic catalysts toward ESR can also be linked to the ability of Mo promoter in enhancing the interaction between NiMo nanoparticles and SiO 2 support materials and restraining agglomeration of Ni nanoparticles, which results in further improvement of NiMo nanoparticle dispersion and inhibit its sintering. The NiMo bimetallic catalysts supported on SBA-15 illustrated the high H 2 yield of ∼ 54% and carbon conversion of ∼ 89% with the excellent stability for ESR performed at 600 °C and the steam-to-carbon ratio of 2 over 65 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • Granulation growth literature is reviewed to find solutions for size prediction. • Two limiting cases for granule size are found and equations determined. • Growth behaviour is also derived by including consolidation behaviour. • The growth prediction matches longstanding growth regime maps strongly. • The solution includes nucleation, growth, and breakage in a continuous solution. Size control in granulation is of great importance yet is often difficult to achieve. While numerical and analytical models have previously been reported there is still no comprehensive model to describe wet agglomeration systems. In this paper the basis for a new analytical solution towards predict limiting granule size is suggested. The focus of the model is on bulk behaviour of the granules where the interactions in the granular bulk after the initial contact between agglomerating granules continues to affect the properties, such as in high-shear granulation as well as flow processes such as pan or drum agglomeration. The model as developed assumes that granule size is limited by both saturation and dynamic interactions, and matches the results in the literature regarding the final and continuous growth behaviour in those systems where the model is appropriate. Based on the factors that limit the size, granule growth behaviour can be predicted as a consequence of consolidation. The model matches the behaviour of systems captured by classical growth regime maps in a more quantitative manner, and should allow improved scaling as the model develops. [ABSTRACT FROM AUTHOR]

Characteristics of thermochemical energy storage (TCES) reactors for temperatures below 125 °C at microscopic and macroscopic levels are investigated in the present paper. These two aspects address the numerical and experimental analysis when developing a TCES to implement efficient and feasible systems. The geometry of the reactors, as well as the choice of the reactive bed, proved to be important in the microscopic aspect. Powerful software such as Comsol Multiphysics is widely used for simulation works with satisfactory results at the macroscopic scale, thus reducing the gaps between reality and virtual design. This review also establishes a schematic description of the microscopic and macroscopic analysis of TCES systems. Up to now, there was no standard document for TCES reactors simulation. A dashboard to perform open and closed TCES reactors simulation is elaborated and the impact on performance analysis in the process is demonstrated. The commercialization of technology remains a big challenge. Given the issues that still arise from the process (the heat and mass transfer dilemma, the advanced and complex simulation models developed that could never be implemented in real prototypes, the incomplete studies that mostly focused on dehydration process rather than both hydration and dehydration processes, the sudden increase in pressure at the beginning of the dehydration reaction, the overestimation of data and parameters used in the simulation work which leads to an overestimation of the performance of the systems, the lack of laboratory-scale design works, and the risk of material erosion or agglomeration), substantial and realistic solutions have been proposed. • Review of TCES reactors at microscopic- and macroscopic scales. • Schematic description of the microscopic analysis of the TCES reactor. • Dashboard for the simulation of open and closed TCES reactors at both scales. • Classification diagram for TCES reactors for open and closed systems. • Performance analysis of TCES reactor systems at macro-and micro-scales. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of concentration models on fluidized bed measurements was studied. • Frequency dominant properties of bubble are unrelated to concentration models. • Selection of bubble threshold is strongly related to concentration models. • A general concentration model given in formula of a power function is proposed. Electrical capacitance tomography (ECT) has been widely applied in gas-fluidized bed measurements, which however is constrained by the sensor designs, image reconstruction algorithms and concentration models owing to the "soft-field" nature. Among the three factors, the concentration models that map the permittivity to solid concentration distribution are less understood. In this paper we present an experimental investigation on the effects of concentration models for the ECT measurements of gas-fluidized beds containing Geldart's group A particles. The results show that the bubble velocity, bubbling frequency and fluidization regime transition velocity are intrinsic whatever the concentration model employed. However, the time-averaged solid concentrations measured by ECT with the conventional concentration models are usually higher than the corresponding results obtained by the bed expansion experiments in homogeneous fluidization. It has been further found that the concentration models can significantly influence the threshold selection in identifying the bubbles and surrounding emulsion phase in gas-fluidized beds. Thus, a new concentration model given in the formula of a power function (ϕ = G α) has been proposed, with the optimal exponent α obtained via the least-square fitting of solid concentration in bed expansion during homogeneous fluidization. The model is robust and the sensitivity analysis shows that the variation of time-averaged solid concentration is negligible (≤ 3%) suppose that α changes by ± 20%. [ABSTRACT FROM AUTHOR]

Incorporating positive temperature coefficient (PTC) ceramic particles into polymer matrices provides a promising solution to suppress the distortion of DC electric field within polymeric insulation caused by the negative temperature coefficient (NTC) of electrical resistivity. However, along with the suppressed NTC effect comes the decrease of dielectric strength due to the agglomeration of PTC particles. Here, we addressed this issue in the epoxy resin system by coating polydopamine onto PTC particles to improve the compatibility with matrix, thus achieving a maintained DC breakdown strength. The improved evenness of PTC particles dispersion also provided sufficient interface to generate interface charge traps, which contributed to the increase of electrical resistivity at elevated temperature. Combined with temperature dependent charge carrier amount affected by PTC filler, NTC effect of epoxy composites was further mitigated and the maximum DC electric field was reduced by 49% within insulation assessed by the simulation of HVDC bushing. The method proposed in this paper is crucially important for the reliable and economic application of composite dielectrics under harsh conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the in-situ Scanning Electron Microscopy (in-situ SEM) technique and three-dimensional (3-D) phase-field simulation were combined to perform a comprehensive study on the kinetics and mechanisms of dewetting (or agglomeration) of a 30 nm NiSi films on Si(100) substrate at 600 °C. The evolution of texture during agglomeration of the polycrystalline NiSi thin film was also studied by ex-situ Electron BackScattered Diffraction (EBSD). The phase-field simulation results showed that abnormal grain growth plays an important role in the dewetting process of polycrystalline films, while the misorientations between the NiSi grains and the Si substrate are the main reason for the agglomeration of NiSi polycrystalline thin film on the monocrystal Si substrate. Moreover, 3-D phase-field simulations coupled with experimental information on misorientation distribution and initial grain size were also performed, and the simulated Ni silicide grain morphology is in good agreement with the in-situ SEM results during agglomeration. In order to slow down or to suppress the agglomeration, it is highly recommended to increase the volume fraction of low angle grains, and/or to decrease the misorientation between the NiSi grain and the Si substrate or between the NiSi grains. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, we investigated the interaction of nanosecond pulsed-periodic infrared (IR) laser radiation at a 50 and 500 Hz repetition rate with aerosol platinum (Pt) and silver (Ag) nanoparticles agglomerates obtained in a spark discharge. Results showed the complete transformation of Pt dendrite-like agglomerates with sizes of 300 nm into individual spherical nanoparticles directly in a gas flow under 1053 nm laser pulses with energy density 3.5 mJ/cm2. Notably, the critical energy density required for this process depended on the size distribution and extinction of agglomerates nanoparticles. Based on the extinction cross-section spectra results, Ag nanoparticles exhibit a weaker extinction in the IR region in contrast to Pt, so they were not completely modified even under the pulses with energy density up to 12.7 mJ/cm2. The obtained results for Ag and Pt laser sintering were compared with corresponding modification of gold (Au) nanoparticles studied in our previous work. Here we considered the sintering mechanisms for Ag, Pt and Au nanoparticles agglomerates in the aerosol phase and proposed the model of their laser sintering based on one-stage for Pt agglomerates and two-stage shrinkage processes for Au and Ag agglomerates. [ABSTRACT FROM AUTHOR]

[Display omitted] • The device for preparation was simple and complex packaging process was avoided. • The superhydrophobic COF/GO X composite was obtained by one-step method without any subsequent surface treatments. • The synergistic effects of COFs and GO overcome the problems of poor stability of GO in water and easy agglomeration of COFs. • The prepared COF/GO 50 coating has high flux for separating oil/water mixture and good acid and alkali resistance. Covalent organic frameworks (COFs) have been emerged as potential coating material because of their rigid porous structure and excellent chemical stability, however, the challenges of complicated preparation process and poor processability are still remained. As a widely used composite matrix, graphene oxide usually suffers from swells and poor acid/base resistance caused by the weakening of π-π interaction between graphene sheets with large interlayer spacing in an aqueous environment. Currently, it is a trend to combine COFs and graphene oxide to utilize their synergistic effect in materials. In this study, a simple one-step method is developed to prepare hybrid materials based on COFs and GO without using any special device generally required for COFs fabrication. Significantly, synergistic effects of COFs and GO which can improve the acid /alkali resistance of GO in water as well as overcome the COFs' tendency to agglomeration further make the hybrid materials stable in separation process. The hybrid materials formed by COFs polymerization and parallel covalent linking to GO were translated into recyclable superhydrophobic composite coating by spraying onto filter paper. The fabricated coatings presented ultra-high oil/water permeation flux of 26,000 L m-2h−1 bar−1 with > 98% separation efficiency. Moreover, the coating exhibited exceptional chemical stability in acid and basic environment with excellent cycling stability. The simple methodology presented here will be expected to open up a new route for the fabrication of COFs based hybrid materials for wide range of applications. [ABSTRACT FROM AUTHOR]

Polyamide 66 (PA66) is a well-known engineering thermoplastic polymer, primarily employed in polymer composites with fillers and additives of different nature and dimensionality (1D, 2D and 3D) used as alternatives to metals in various technological applications. In this work, carbon black (CB), a conductive nanofiller, was used to reinforce the PA66 polymer in the 9–27 wt. % CB loading range. The reason for choosing CB was intrinsically associated with its nature: a nanostructured carbon filler, whose agglomeration characteristics affect the electrical properties of the polymer composites. Crystallinity, phase composition, thermal behaviour, morphology, microstructure, and electrical conductivity, which are all properties engendered by nanofiller dispersion in the polymer, were investigated using thermal analyses (thermogravimetry and differential scanning calorimetry), microscopies (scanning electron and atomic force microscopies), and electrical conductivity measurements. Interestingly, direct current (DC) electrical measurements and conductive-AFM mapping through the samples enable visualization of the percolation paths and the ability of CB nanoparticles to form aggregates that work as conductive electrical pathways beyond the electrical percolation threshold. This finding provides the opportunities to investigate the degree of filler dispersion occurring during the transformation processes, while the results of the electrical properties also contribute to enabling the use of such conductive composites in sensor and device applications. In this regard, the results presented in this paper provide evidence that conductive carbon-filled polymer composites can work as touch sensors when they are connected with conventional low-power electronics and controlled by inexpensive and commercially available microcontrollers. [ABSTRACT FROM AUTHOR]

In this work, pineapple leaf fiber (PALF) and ramie hybrid fiber‐reinforced epoxy composite samples were evaluated for their hardness strength and resistance to dry slide wear and air jet erosion. Primary reinforcement using the hybrid material was chosen from different lengths (10, 15, 20, and 25 mm) and weight percentages (10%, 20%, 30%, 40%, and 50%). The hardness strength of the hybrid composite varied from 74 to 97 Shore D hardness strength. A dry sliding wear test was conducted with the key parameters of load (20, 30, and 40 N), time (20, 10, 7 min), and speed (160, 320, and 479 rpm). By using the data analyzing software, Taguchi optimization method, the key contribution parameters were identified. In the air jet erosion experiment, impact angle (45°, 60°, and 90°), erodent velocity (28, 41, and 72 m/s), and discharge rate (1, 2.5, and 3.3 g/min) parameters were used. Fiber and matrix materials agglomeration effect and bonding behavior were identified by using the scanning electron microscope (SEM) images. The 20 mm length with 30% of the PALF and ramie hybrid fiber‐reinforced composite sample achieved high hardness strength (97 shore D) and created a high resistance toward wear and erosion studies. Highlights: Natural plant pineapple leaf and ramie fibers are mixed with an epoxy matrix.Used Taguchi analysis to determine the means and signal‐to‐noise ratiosDifferent weight percentages of the PALF and ramie hybrid compositesDry sliding wear and air jet erosion studies are conducted.Individual parameter contributions were identified. [ABSTRACT FROM AUTHOR]