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In recent time, magnetically controlled shunt reactors are widely used in solving power quality problems. These reactors are designed to reduce system reactive power, control high super/special high voltage grid voltage, suppress power frequency, regulate overvoltage, eliminate generator excitation, dynamically compensate transmission line power charge, suppress secondary arc current, suppress system resonance. By using suitably designed silica plate core reactors at the input of the frequency converters in the electrical distribution system, the level of harmonic currents drawn from the electrical power distribution system can be reduced to certain rates. The core material, the air-gapped nature of the reactor core, and the sizing of the reactor have a great influence on the harmonic level of the current and its ability to reduce losses in the reactor. In this study, three reactors with different core materials and different air gap gaps are designed for a certain voltage value. Parametric analysis of the reactors designed to see the changes in inductance values depending on the load level has been made both theoretically and experimentally and using the Finite Element Method. As a result of the analysis, the inductance stability, losses and compliance of the reactors with the standards are presented. The reactor's magnetic circuit is modeled with ANSYS@Maxwell, realizing a solution based on this method. The magnetic circuit is simulated to see the behavior of the reactor. In addition, real-time verification of the designed alternating current reactor has been made. Optimum design was obtained by using different core materials and different core air-gaped tested experimentally. The effect of the air gap distance in the core on the magnetic field and inductance value was also obtained. [ABSTRACT FROM AUTHOR]

Propolis is a well-known natural antibacterial substance with various biological activities, such as anti-inflammatory and antioxidant activity. However, applications of propolis are limited due to its low water solubility. In this study, propolis microcapsules were developed with a core material of ethanol extract of propolis and shell materials of gum arabic and β-cyclodextrin using a spray-drying technique. The optional processing formula, particle size distribution, morphology, dissolution property, and antibacterial activity of propolis microcapsules were determined. The results showed that the optional processing obtained an embedding rate of 90.99% propolis microcapsules with an average particle size of 445.66 ± 16.96 nm. The infrared spectrogram and thermogravimetric analyses showed that propolis was embedded in the shell materials. The propolis microcapsules were continuously released in water and fully released on the eighth day, and compared to propolis, the microcapsules exhibited weaker antibacterial activity. The minimum inhibitory concentrations (MICs) of propolis microcapsules against Escherichia coli and Staphylococcus aureus were 0.15 and 1.25 mg/mL, and their minimum bactericidal concentrations (MBCs) were 0.3 and 1.25 mg/mL, respectively. This water-soluble propolis microcapsule shows the potential for use as a sustained-release food additive, preservative, or drug. [ABSTRACT FROM AUTHOR]

The relevance of the subject under study is determined by the considerable spread of information technology in all spheres of modern life and the impact of informatics systems on society. The purpose of this study was to investigate the essence and resource of the integrated unitary management process, which formulates and reveals the concept of integrated unitary management process, its specified content, categories of resources, their interrelation, differentiation from the informative side of the functioning of this process, the sequence of integration of its elements. The conceptual essence and resources of the unitary management process are revealed. The hierarchy, ranks and conceptual value of the materialinformation processes of the management system objects are highlighted and characterized. In this study, results were obtained indicating that conceptually, an integrated unitary management system, compared to the existing discrete management system, is characterized by a range of key indicators. Specifically, all categories of human activity (material, informational: informative (situational, cognitive) and decisional) through their direct interrelations and interactions are realized as a unified whole. At the level of organization, the system is completed in the form of a material and informational core. Regardless of the dimensionality of the spatiotemporal rays of the system, the superiority of the managerial rank, the influence potential over any managed element has the same intensity as at the primary level. The functioning management system is an analog action that works in real-time in accordance with the decisional values of which the evolution of the managed subject automatically changes. [ABSTRACT FROM AUTHOR]

Permanent magnet motors have become an important component of industrial production, transportation, and aerospace due to their advantages of high torque density, high power density, high reliability, low losses, and high efficiency. Permanent magnet claw pole motor (PMCPM) is a special type of transverse flux motor which has a higher torque density compared to traditional permanent magnet motors. Due to the absence of winding ends, its axial space utilization is high, and the usage of windings is greatly reduced, reducing the cost and weight of the motor. PMCPM has the advantages of small space, a light weight, a high torque density, a high efficiency, and simple production, which have potential for use in the field of electric vehicles. The double-stator structure design can improve the torque density, efficiency, and radial space utilization of PMCPM, which helps to expand their applications in the field of electric vehicles. This article designs two PMCPM with concentrated winding while different rotor structures (PMCPM1 and PMCPM2) and a three-dimensional finite element method is employed to compare and analyze the performance of PMCPM1 and PMCPM2 and the traditional PMCPM (TPMCPM). Multiphysics analysis is carried out for PMCPM1 and PMCPM2. The stress of the inner and outer stators during interference assembly are analyzed. In this paper, a hybrid material core design is proposed, in which the stator yoke is rolled by silicon steel material and the stator claw pole is pressed by the SMC die method. The multiphysics simulation performance of the PMCPM1 and PMCPM2 with hybrid cores is analyzed. [ABSTRACT FROM AUTHOR]

Liposomes have become a research hotspot in recent years as food delivery systems with attractive properties, including the bilayer structure assembled like the cell membrane, reducing the side‐effect and improving environmental stability of cargos, controlling release, extending duration of functional ingredients, and high biodegradable and biocompatible abilities in the body. However, the conventional liposomes lack stability during storage and are weak in targeted absorption in the gastrointestinal track. At present, surface modification has been approved to be an effective platform to shield these barricades and help liposomes deliver the agents safely and effectively to the ideal site. In this review, the gastrointestinal stability of conventional liposomes, cargo release models from liposomes, and the biological fate of the core materials after release were emphasized. Then, the strategies in both physical and chemical perspectives to improve the stability and utilization of liposomes in the gastrointestinal tract, and the emerging approaches for improving gut targeting by specifically modified liposomes and the intestinal receptors relative to liposomes/cargos absorption were highlighted. Last but not the least, the safety, challenges, and opportunities for the improvement of liposomal bioavailability were also discussed to inspire new applications of liposomes as oral carriers. [ABSTRACT FROM AUTHOR]

Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, ethyl cellulose was used as a wall material, propanetriol as a core material, polyvinyl alcohol as a stabilizer and gelatin as an emulsifier. Self-healing microcapsules with a slow-release effect were prepared using the solvent evaporation method. Various analytical techniques, such as 3D confocal microscopy (LCSM), optical microscopy (OM), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS), thermal weight loss analysis (TGA), laser particle size tester and electrochemical impedance polarization, are utilized. The morphology, distribution, particle size, corrosion resistance and self-healing ability of the prepared microcapsules and resin-based coatings were characterized and analyzed. The results show that the cross-sectional core–shell structure is clearly seen in the LCSM, showing a smooth, hollow, spherical shape. OM and laser particle size testers have shown that the size of the microcapsules decreases over time. Also, in OM, the microcapsules are uniformly distributed in the emulsion with a smooth and non-adherent surface. In SEM, the microcapsule particle size is about 150 μm, the shell wall thickness is about 18 μm, and the hollow structure of ruptured microcapsules is obvious. FT-IR and TGA confirmed the successful encapsulation of the formulated microcapsules. The results show that when the core-wall mass ratio is 1.2:1 and the amount of microcapsule is 10% of the coating amount, the prepared microcapsule has high thermal stability and certain wear resistance. By electrochemical and immersion experiments, it was found that a 3.5 wt % NaCl solution has the best impedance, the lowest corrosion current density, and good adhesion and tensile toughness. The results showed that glycerol was successfully released from the broken microcapsules and self-healed, forming an anticorrosive coating with excellent corrosion resistance and self-healing ability. [ABSTRACT FROM AUTHOR]

A mixture of multiwalled carbon nanotubes (CNTs) and carbonyl iron powder (Iron(0) pentacarbonyl, CIP) was used as a core material, and a melamine-formaldehyde resin was used as a wall material to prepare CIP/CNTs microcapsules. A core-wall ratio, content of CNTs in the core material, stirring speed, and reaction time were carried out to explore the most significant factor affecting the coverage rate and yield of microcapsules. The most important factor affecting the preparation of CIP/CNTs microcapsules was the content of CNTs in the core material. The optimized CIP/CNTs microcapsules were mixed with shellac microcapsules, and the optimal ratio was explored by analyzing their optical, mechanical, and electromagnetic wave absorption properties in order to prepare coatings with superior performance. The lower the addition amount of CIP/CNTs microcapsules, the lower the effect on the color difference of the coating. The gloss and adhesion of waterborne wood paint coatings decreased with increasing CIP/CNTs microcapsule addition. The hardness, impact resistance and tensile properties of the coatings showed a tendency of increasing and then decreasing with the addition of CIP/CNTs microcapsules. The surface roughness of the coating basically tended to increase with the increase of CIP/CNTs microcapsule content. When the content of added CNTs in the core material was 3.0% and the content of microcapsules was 9.0%, the coating had the highest elongation at break of 12.4% and the highest repair rate of 34.3%, respectively. The mixed shellac microcapsules and CIP/CNTs microcapsules achieved a theoretical minimum reflection loss of −13.52 dB at 16.2 GHz, and the electromagnetic wave absorption band of less than −5 dB was 15.3 GHz–18.0 GHz. The results provide technical references for the preparation of self-healing composite electromagnetic wave absorption coatings on wood substrates. [ABSTRACT FROM AUTHOR]

The explosion products, such as shock waves, fragments and heat energy formed by explosion, act on the plate structure, which may cause structural damage, material failure and even phase transformation of material. In this paper, the damage mechanism and protective effect of near-field blast load on sandwich structure based on foam-nickel core material were studied. Firstly, the near-field explosion test was conducted to investigate the blast response of the foam-nickel sandwich structure subjected to blast shock from 8701 explosive at near-field position. The deformation characteristics and stress history of the sandwich structure on the acting location of blast load were carefully investigated via experimental methods. A finite element model of near-field explosion was established for effective numerical modelling of the dynamic behaviour of the sandwich structure using the explicit dynamics software ANSYS/LS-DYNA for more comprehensive investigations of the blast shock response of the sandwich structure. The finite element model is reasonable and validated by mesh independence verification and comparing the simulated response behaviour to that from the experimental results for the sandwich structure subjected to near-field blast load. On this basis, the damage mechanism and protection effect of the near-field explosion impact on foam-nickel cores with different density and porosity are simulated more systematically. The investigated results from the experiments and a series of numerical simulations show the large deformation effect due to the extensive energy absorption, which suggests that the sandwich structure based on foam-nickel core material may be expected to become a new choice of protective structure under near-field blast load. [ABSTRACT FROM AUTHOR]

Industrial machines with sharp moving blades are extremely dangerous to workers. These machines often rotate for some time (called the run-down time) before completely stopping due to little or no brakes. In the case where brakes are used, they are mechanical in nature and are associated with problems of wear out and frequent maintenance among others. In this paper, we proposed a mathematical model and implementation of an electromagnet and design and construction of a mechanical support frame and a controller for the electromagnetic braking system. The electromagnetic braking system works on the principle of electromagnetism. To realize the semicircular electromagnets, we coil the gauge wires several times around a ferromagnetic core material. The electromagnet was connected to a 12 V 7 Ah battery and was used to lift a load whose mass and corresponding weight were predetermined using a scale balance. The magnetic force generated was equal to the amount of maximum load it could lift. The mechanical frame, on which the electromagnets, motor, battery, switches, and chain drive system were mounted, was designed using SolidWorks and constructed by measuring, cutting, and joining of iron materials. A microcontroller and a power MOSFET were used in the control circuit to drive the electromagnet. Major results such as the realized electromagnets and the magnitude of the electromagnetic force (1.43 N) produced by the electromagnets are presented. The mechanical frame and the control circuit are also presented. The braking force was greater than the rotation torque of the disc, and hence braking was achieved. [ABSTRACT FROM AUTHOR]

Saving energy from domestic appliances is a focus in the effort to combat energy challenges. Linear compressors are a more efficient alternative to the traditional compressors used in refrigerators, which account for 20–40% of all residential electricity use. This article investigates the new topology of the moving magnet (MM), dual-stator single-mover linear oscillating actuator (DSSM-LOA) for linear compressor application. Both the stators were C-shaped, with coils looped across their end sides. Two permanent magnets (PMs) that were axially magnetized were housed on the mover. The PM structural shape significantly affected its fabrication cost and magnitude of magnetic flux density ( B ). The DSSM-LOA makes use of axially magnetized rectangular-shaped PMs because they are inexpensive and generate high electromagnetic (EM) force density. End ferromagnetic core materials were used to improve the magnetic flux, linking from the stator to the mover. All the design parameters were optimized through parametric analysis using the finite parametric sweep method. Parameters present within the three primary parameters (length, height, and depth) that were assumed constants were optimized, and the optimal dimensions were selected based on the EM force. The investigated DSSM-LOA was contrasted with traditional LOA designs, and they showed significant improvement in EM force per ampere, generally named motor constant (MC), MC per PM mass, MC density, cogging force, and stroke. Additionally, the proposed DSSM-LOA had a simple structure and low cost, and it operated in a feasible range of strokes for linear compressor application. [ABSTRACT FROM AUTHOR]

Ni/CaO, a low-cost dual-functional material (DFM), has been widely studied for integrated CO2 capture and hydrogenation. The core of this dual-functional material should possess both good CO2 capture–conversion performance and structural stability. Here, we synthesized Ni/CaO DFMs modified with alkali metals (Na, K, and Li) through a combination of precipitation and combustion methods. It was found that Na-modified Ni/CaO (Na-Ni/CaO) DFM offered stable CO2 capture–conversion activity over 20 cycles, with a high CO2 capture capacity of 10.8 mmol/g and a high CO2 conversion rate of 60.5% at the same temperature of 650 °C. The enhanced CO2 capture capacity was attributed to the improved surface basicity of Na-Ni/CaO. In addition, the incorporation of Na into DFMs had a favorable effect on the formation of double salts, which shorten the CO2 capture and release process and promoted DFM stability by hindering their aggregation and the sintering of DFMs. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate that optical pulling forces (OPFs) can be induced by a hybrid dimer consisting of a Si nanoparticle (NP) and a coated nanoparticle with a gain core and Au shell under normal plane wave illumination. Analytical theory reveals that the underlying physical mechanism relies on interactions between the electric dipole (ED) modes excited in the NPs. As compared with the individual NP, it is found that the magnitude of optical force can be enlarged by almost three orders for the Si NP and one order for the coated gain NP in the coupled dimer. In addition, we find that the OPFs exerted on the NPs are heavily dependent on the gain level of the core materials, the incident polarization angle and the sizes of the NPs. More interestingly, we find that the OPF can also be exerted on a trimer system consisting of two identical Si NPs and a coated NP arranged in a line. The related results could be used to propose a versatile platform for manipulating NPs. [ABSTRACT FROM AUTHOR]

Purpose: To examine the fracture strength and fracture mode of flared root canals reinforced with different post and core materials. Materials and methods: Forty endodontically treated bovine teeth structured to mimic human mandibular premolars with flared root canals were reinforced with resin composite and glass fiber post (FRC), composite resin (RC), ceramic core (LD), and ceramic core with resin composite reinforcement (RLD), and restored with single zirconia crowns (n = 10 in each group). The fracture strength and mode of the root canals restored with zirconia crown were assessed. The fracture strength was compared with a one‐way analysis of variance (ANOVA) following Tukey HSD tests. A multiple regression analysis was conducted to test the effect of the post/core materials on the fracture loads. Fisher's exact test was used in the failure mode analysis. Results: The mean fracture strength of RLD was significantly higher than RC, FRC, and LD (p < 0.05), while no significant differences were found among RC, FRC, and LD (p < 0.05). The regression analysis found that the fracture strength using the lithium disilicate was significantly lower for the post and higher for the core than that using the resin composite (p < 0.05), and there were no significant difference in the fracture strengths between the resin composite and glass fiber used for the post (p > 0.05). Most of the specimens exhibited root fractures, and no significant differences were observed among the groups (p < 0.05). Conclusions: The results of this study suggest that reinforcement of flared root canals using a combination of resin composite for the core and lithium disilicate ceramic for the post is superior to resin composite and glass fiber in mechanical properties when restoring a single crown. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Educational Studies (1673-1298) is the property of Journal of Educational Studies Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the hasten development of the new energy industry, the recycle of power and energy storage lithium-ion batteries began to be gradually valued. In order to ensure the cleanliness and environmental protection of the whole life cycle of lithium-ion batteries, the feasibility of recycling the positive and negative core materials in lithium-ion batteries needs to be further evaluated, so as to achieve the closed loop of the new energy industry chain with lithium-ion batteries as the core. The properties of a recycled LiFePO4 cathode material are verified, and the effect of changes in physical and chemical indexes of the material on the processing performance and the impact of the electrical performance after processing into a battery are evaluated. The results show that the main physical properties of recycled LiFePO4 obtained by physical drying method can meet the requirements of battery manufacturing grade. ICP test results show that the Al content is high, magnetic impurities, gram capacity and recovery powder particle size distribution and other physical and chemical indicators are not significantly abnormal, but there is still a large room for improvement, by following the process processing performance of the recovery of LiFePO4, the direct current resistance of the pole is fluctuates. The results of charge storage at room temperature test show that the capacity retention rate of the cell after 28 days has reached more than 92%, recovery rate more than 93%, which meets the requirements of the national standard, indicating that the necessary demagnetization operation to increase the powder and slurry plays a certain role in reducing the risk of self-discharge of the final finished battery. The cell cycle test results show that the capacity retention rate of 0.2 C for 100 cycles is more than 95%, which is comparable to the normal LiFePO4 processing of the cell cycle performance level. [ABSTRACT FROM AUTHOR]

The reconstruction of accurate sea‐surface temperatures (SST) is of utmost importance due to the ocean's central role in the global climate system. Yet, a number of environmental processes might bias reliable SST estimations. Here, we investigate the fidelity of SST reconstructions for the western tropical South Atlantic (WTSA) for the interval covered by Marine Isotope Stages (MIS) 6–5, utilizing a core collected off eastern Brazil at ∼20°S. This interval was selected as previous SST estimates based on Mg/Ca ratios of planktic foraminifera suggested a peculiar pooling of warm surface waters in the WTSA during MIS 6 despite glacial boundary conditions. To ground‐truth the Mg/Ca‐based SST data we generated SST reconstructions on the same core material using the alkenone and TEX86 paleothermometers. Comparison with alkenone‐based temperature estimates corroborate the previous Mg/Ca‐based SST reconstructions, supporting the suggestion of a warm‐water anomaly during MIS 6. In contrast, TEX86‐derived temperatures, albeit representing annual mean SST in recent core top samples, are up to 6°C colder than Mg/Ca‐ and alkenone‐based SST reconstructions. We interpret the periods of anomalously cold TEX86‐temperatures as a result of a vertical migration of the TEX86 producers (heterotrophic marine Thaumarchaeota) toward greater water depths, following food availability during phases of enhanced fluvial suspension input. Likewise, the data suggest that alkenone‐based SST are, albeit to a minor degree when compared to TEX86, affected by river run‐off and/or a seasonal bias in the growth season of haptophyte algae. Plain Language Summary: In this study, we investigate the accuracy of sea‐surface temperature (SST) reconstructions for the western tropical South Atlantic (WTSA) for the interval covered by Marine Isotope Stages (MIS) 6–5—the penultimate glacial‐interglacial cycle (ca. 190,000 to 70,00 years before present). This time interval was selected because previous SST estimates based on Mg/Ca ratios of planktic foraminifera suggested a pooling of warm surface waters in the WTSA during late MIS 6 despite the cold glacial conditions. To verify the Mg/Ca‐based SST data, we generated temperature reconstructions from a core located off Eastern Brazil using two common paleothermometers that based on lipid biomarkers: alkenone and TEX86. The alkenone‐based temperature estimates agree with previous Mg/Ca‐based SST reconstructions, supporting the existence of a warm‐water anomaly in the WTSA during MIS 6. On the other hand, TEX86‐derived temperatures were up to 6°C colder than Mg/Ca‐ and alkenone‐based SST reconstructions. This discrepancy might be a result of a vertical migration of the TEX86 producers toward greater water depths where they feed on particles of organic matter. These migrations into deeper waters occurred during phases of increased river run‐off fluvial suspension input which enhanced surface primary productivity and facilitated vertical particle flux through the water column. Key Points: Parallel Mg/Ca (Globigerinoides ruber), alkenone and TEX86‐based temperature estimates in the western tropical South Atlantic (WTSA) across Marine Isotope Stages (MIS) 6–5Mg/Ca and alkenones represent annual mean sea surface temperatures, but most TEX86‐based temperatures deviate to colder valuesAnomalous sea surface warming in the WTSA during late MIS 6 appears as a robust signal [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wicking in textiles is a key property of fabric moisture permeability, which has been found to be dominant in the comfort-maintaining mechanism of apparel products, especially for sportswear that has high requirements for sweat transfer. Various methods have been given in order to improve moisture transfer behavior of fabrics, among which fiber modification is the most direct and ideal way. In this article, a design-driven yarn structure spinning model for moisture wicking improvement is established by using a helically shaped covering material to limit the inter-fiber spacings of the staple core yarn so that an improvement in effective capillary channels with better continuity can be achieved. The developed yarn constructions combine the advantages of natural and synthetic fibers, showing significant improvements on moisture wicking performance, fast-drying effects as well as commercial values. Experiments on the fabrics made in accordance achieved excellent results both before and after washing. For the most efficient fabric 5 with cotton-linen as the core material, the average diffusion time was decreased by 86.4% and 66.5% before and after washing, compared with the core yarn. Excessively large water absorption rates of the control fabrics were limited and decreased by 22.1% and 32.4%. The evaporation rates of the fabric were increased by 25.6% and 18.5%, indicating obvious improvements in fast drying effects. Through various experiments, the optimal spinning parameters were investigated which provided methods and established foundations for subsequent research. The finding in this study offer the possibility of fiber moisture performance modification with high efficiency, low cost, and environmental sustainability. [ABSTRACT FROM AUTHOR]

In this work, three different types of sandwich structures were manufactured, each using a Formica sheet (a paper-based sheet) as the skin and perlite/sodium silicate foam as the core, with or without a paper honeycomb. The sandwich structures were fabricated by attaching the Formica sheets on both sides of a paper honeycomb core panel, a perlite/sodium silicate foam core panel, and a perlite/sodium silicate foam-filled honeycomb core panel. The flexural characteristics were studied by a three-point bending test and the thermal conductivity was measured using Lee's thermal conductivity apparatus. The results demonstrated a significant improvement in flexural properties, including core shear stress, facing stress, bending stress, and energy absorption, when incorporating the paper honeycomb reinforcement. The thermal conductivity and flexural properties of the paper honeycomb reinforced and unreinforced perlite/sodium silicate foam-based sandwich panels were found to be very compatible with existing building materials described in the literature that are used for similar applications. The failure investigation revealed that the sandwiches with paper honeycomb failed prematurely only due to core buckling, while the foam-filled honeycomb core-based sandwiches were able to sustain higher loads while exhibiting material failures such as core shear failure, skin rapture, and delamination. It was found that the foam-filled paper honeycomb sandwich structures can withstand higher bending loads than the foam core-based sandwich structure or the paper-honeycomb-based sandwich structure. These developed sandwiches offer potential as green materials due to the characteristics of their constituent materials and they can provide valuable applications in the thermal insulation of buildings. [ABSTRACT FROM AUTHOR]

In this paper, a chitosan-modified nano-silver solution was used as the core material of an antibacterial agent, and melamine formaldehyde resin was coated onto the core material to obtain the antibacterial microcapsules. The core/wall ratio, the stirring rate, the mass ratio of chitosan to silver ions, and the concentration of the emulsifier were used to carry out four-factor and three-level orthogonal experiments to explore the most significant factors affecting the coverage rate and output of microcapsules and the best preparation technology. The results showed that the concentration of the emulsifier was the most important factor affecting the preparation of microcapsules. The higher the concentration of the emulsifier, the better the dispersed morphology of microcapsules, and the higher the coverage rate, up to 44.0%. The antibacterial coating was prepared by mixing microcapsules with a waterborne primer at a content of 4.0%. Its optical properties, mechanical properties, and antibacterial properties were analyzed. By increasing the concentration of the emulsifier, the gloss of the coating showed a trend of first increasing and then decreasing. When the emulsifier concentration was 2.0%, the gloss of the Andoung wood surface coating reached the maximum value of 21.23%. The influence of emulsifier concentration on the color difference of coating had no obvious law, and it was negatively related to the light transmittance. In terms of mechanical properties, the concentration of the emulsifier is directly proportional to the hardness and impact resistance of the coating, with the maximum reaching 31 kg·cm, and is negatively related to adhesion and roughness. In terms of antibacterial properties, the higher the concentration of the emulsifier, the better the antibacterial properties of the coating. When the concentration of the emulsifier was 4.0%, the antibacterial rates of coating which coated the glass substrate were 71.3% and 80.0% for Escherichia coli and Staphylococcus aureus, respectively. The antibacterial rates of the Andoung wood surface coating reached the maximum, which were 68.4% and 73.2%, respectively, and the antibacterial performance was excellent. In this study, an efficient antibacterial microcapsule for waterborne coatings was prepared, which provided the reference value for the application of antibacterial microcapsules in waterborne coatings. [ABSTRACT FROM AUTHOR]

Using microencapsulation technology and the natural antimicrobial properties of aloe-emodin, the antimicrobial microcapsules were prepared by in situ polymerization using urea-formaldehyde resin as the wall material and aloe-emodin as the core material. The antimicrobial microcapsules were mixed into waterborne coatings to improve the antimicrobial ability of waterborne paint films against bacteria for better protection of substrates. The purpose of this study was to optimize the preparation process of aloe-emodin antibacterial microcapsules. With the variety and concentration of emulsifiers as the changing factors, three different emulsifiers, namely sodium dodecyl benzene sulfonate SDBS, OP-10, and Tween-80, were selected to explore the effects of emulsifier type and microcapsule loading on the physicochemical and the antibacterial properties of waterborne paint films, and the morphology, chemical composition, antibacterial properties, optical properties, and roughness of the paint films were tested and analyzed. The results showed that all the emulsifiers with 3.0% concentration in the microencapsulation preparation were better than 1.0%. The performance of the microencapsulated varnish films prepared with the addition of the three emulsifiers had advantages and disadvantages, with the highest antibacterial rates of 77.1%, 55.4%, and 65.9% for Escherichia coli and 70.0%, 63.9%, and 60.7% for Staphylococcus aureus, respectively. The antibacterial properties of the microencapsulated varnish film prepared by adding SDBS emulsifier were slightly above those of the other two groups. The three sets of paint films' color differences rose, the gloss reduced, the rate of light loss increased, the rate of light transmission fell, and the roughness increased with an increase in microencapsulated content. Aloe-emodin microcapsules enable the water-based coating to have antibacterial properties, expanding the application range of water-based coatings. [ABSTRACT FROM AUTHOR]

The release rate of liquid core material from microcapsules is crucial for the surface properties of self-protective metal/liquid microcapsule composite plating coating. However, there is no method to accurately predict the release rate of microcapsules. In this paper, the permeability experiments of different shell membranes and core materials were carried out using the weight loss method, and the permeability model of liquid microcapsules was studied based on a multiple linear regression method. The results show that three-variable mathematical model C, including membrane porosity, the viscosity of core material, and membrane thickness is suitable to describe permeability, and the membrane thickness is the most significant influence factor. Additionally, the accuracy of model C was experimentally verified, and the error of the permeation rate is about 2.06% between predictive and experimental values. [ABSTRACT FROM AUTHOR]

Switched reluctance motors (SRM) becomes increasingly popular due to its simple structure and dependability. It seems to have a two-pole configuration. A stator had also centralized coils along each pole, whereas a rotor has an iron core only. As a result, the switched reluctance motor is anticipated to be a lowcost, incredibly robust variable-speed machine. Because the switched reluctance motor is only made up of laminated coils, its performance is heavily reliant on the magnetic properties of the core material. Vibration, torque ripple, and low torque for each unit volume are some of their drawbacks. Typically, a standard proportional-integral-derivative (PID) controller is designed to regulate the Switched Reluctance Motor's speed. Furthermore, the PID controller could also regulate and control SRM when the load changes abruptly. A fuzzy logic controller (FLC) is utilized within this article to regulate the speed of the SRM drive. The MATLAB/Simulink platform is used to analyze the behavior of SRM with FLC. To demonstrate FLC's superiority, its results have been compared to that of a typical PID controller. [ABSTRACT FROM AUTHOR]

Autologous bone transplantation is still considered as the gold standard therapeutic option for bone defect repair. The alternative tissue engineering approaches have to combine good hardiness of biomaterials whilst allowing good stem cell functionality. To become more useful for load-bearing applications, mechanical properties of calcium phosphate materials have to be improved. In the present study, we aimed to reduce the brittleness of β-tricalcium phosphate (β-TCP). For this purpose, we used three polymers (PDL-02, -02a, -04) for coatings and compared resulting mechanical and degradation properties as well as their impact on seeded periosteal stem cells. Mechanical properties of coated and uncoated β-TCP scaffolds were analyzed. In addition, degradation kinetics analyses of the polymers employed and of the polymer-coated scaffolds were performed. For bioactivity assessment, the scaffolds were seeded with jaw periosteal cells (JPCs) and cultured under untreated and osteogenic conditions. JPC adhesion/proliferation, gene and protein expression by immunofluorescent staining of embedded scaffolds were analyzed. Raman spectroscopy measurements gave an insight into material properties and cell mineralization. PDL-coated β-TCP scaffolds showed a significantly higher flexural strength in comparison to that of uncoated scaffolds. Degradation kinetics showed considerable differences in pH and electrical conductivity of the three different polymer types, while the core material β-TCP was able to stabilize pH and conductivity. Material differences seemed to have an impact on JPC proliferation and differentiation potential, as reflected by the expression of osteogenic marker genes. A homogenous cell colonialization of coated and uncoated scaffolds was detected. Most interesting from a bone engineer's point of view, the PDL-04 coating enabled detection of cell matrix mineralization by Raman spectroscopy. This was not feasible with uncoated scaffolds, due to intercalating effects of the β-TCP material and the JPC-formed calcium phosphate. In conclusion, the use of PDL-04 coating improved the mechanical properties of the β-TCP scaffold and promoted cell adhesion and osteogenic differentiation, whilst allowing detection of cell mineralization within the ceramic core material. [ABSTRACT FROM AUTHOR]

A core–shell ceramic with a composition of 0.65Ba0.85Sr0.15TiO3–0.35Ni0.75Zn0.25Fe2O4 (BST–NZF) has been synthesized using a microwave-assisted hydrothermal technique. The magnetoelectric properties of core–shell systems are primarily influenced by the interaction between the core and shell materials, which, in turn, is dependent on the synthesis conditions. The composition and synthesis conditions were optimized in this investigation to produce a core–shell ceramic with improved magnetoelectric properties. The results of Rietveld analysis, high-resolution transmission electron microscopy (HRTEM), and selected area diffraction (SAED) analysis confirmed the successful preparation of the dual-phase 0.65Ba0.85Sr0.15TiO3–0.35Ni0.75Zn0.25Fe2O4 core–shell ceramic. The core consisted of the perovskite Ba0.85Sr0.15TiO3 with a tetragonal crystal structure, and the shell was comprised of ferrite Ni0.5Zn0.5Fe2O4 with a cubic spinel structure. Additionally, a moderate magnetoelectric coefficient of 12.41 mV/cm Oe was observed for the BST–NZF core–shell ceramic. The improvement in the magnetoelectric properties without hampering the electrical characteristics suggests the potential application of the environmentally friendly BST–NZF ceramic in biomedical fields. [ABSTRACT FROM AUTHOR]

Background. This study aimed to evaluate the final color of restorations with three different core materials (Co–Cr, Zirconia, and PEEK) veneered with heat-pressed ceramic or CAD/CAM composite. Methods. Forty cores in the form of square with dimensions of 10 × 10 mm and thickness of 0.5 mm were milled from Zirconia and Co–Cr blocks and were veneered with either A2 shade CAD/CAM composite resin or heat-press ceramic (n = 10). Ten samples from polyetheretherketone blocks were only veneered with composite resins. A2 shade veneer material with 2 mm served as control for color evaluation of samples. Color parameters were measured by spectrophotometer. The data were analyzed using one-way ANOVA and Tukey's post hoc test. Results. The mean color differences between Co–Cr, Zirconia and PEEK samples veneered with composite and the control sample were 2.91 (±0.45), 3.24 (±0.33), and 2.75 (±0.35) and for Co–Cr and Zirconia in ceramic groups were 6.46 (±0.32) and 1.97 (±0.19), respectively. One-way ANOVA and Tukey's post hoc test showed a significant difference between the core groups veneered with ceramic (P ≤ 0.001). The type of core material in the composite veneered samples, however, did not make a significant difference (P = 0.186). All groups except for Co–Cr-ceramic showed clinically acceptable results (ΔE < 3.7). Conclusion. Type of core material presented significant effect on the final color of restorations when ceramic was used as a veneer material. Conversely, the final color of composite veneer restorations is not affected by the core type. CAD/CAM composites can provide adequate color coverage for different core materials without exceeding a minimum clinically acceptable thickness. [ABSTRACT FROM AUTHOR]

Several core‐shell nanofiber electrodes are prepared through electrospinning and tested for application as intermediate‐temperature solid oxide fuel cell (IT‐SOFC) cathodes. The materials investigated are La0.6Sr0.4MnO3 (LSM), La0.6Sr0.4Cu0.1Mn0.9O3‐δ (LSCuM_1), and La0.6Sr0.4Cu0.2Mn0.8O3‐δ (LSCuM_2) perovskites, used at the shell side of the nanofibers. Ce0.9Gd0.1O1.95 (GDC10) fluorite is used as the core material. The electrochemical characterization of the core‐shell nanofiber electrodes is performed through electrochemical impedance spectroscopy (EIS). The EIS results are reported and discussed based on equivalent circuit modeling. The polarization resistance of the GDC10/LSM core‐shell nanofibers electrodes is RP∼4.5 Ω cm2 at 650 °C. Improvement is accomplished with GDC10/LSCuM_1 and GDC10/LSCuM_2 core‐shell nanofibers, with RP∼1.8 Ω cm2 and 1.7 Ω cm2 respectively at 650 °C. Post‐test SEM characterization is carried out, to ascertain possible degradation and identify the most promising shell perovskite. [ABSTRACT FROM AUTHOR]

The common, commercial reversible thermochromic (RT) melamine–formaldehyde resin microcapsules containing formaldehyde are very harmful to human health. To address this issue, we successfully prepared a novel formaldehyde-free microcapsule via interfacial polymerization using RT compositions as the core and poly(urethane-urea) (PUU) as the shell. The core material consisted of a color former (crystal violet lactone), a developer (bisphenol AF), and a solvent (methyl stearate). To optimize the synthesis of the microcapsules, an L9 (34) orthogonal design and single-factor experiments were employed to analyze the effects of four factors (N3300-to-L75 shell material mass ratio, core-to-shell material mass ratio, emulsifier concentration, and shear rate during emulsification) on the encapsulation efficiency. The results showed that the optimal parameter values were as follows: a shear rate of 2500 rpm, N3300-to-L75 shell material mass ratio of 1:4, core-to-shell material mass ratio of 11:5, and emulsifier concentration of 3.5%. The influence of the shear rate on the particle size and distribution, surface morphology, dispersibility, and reversible thermochromic properties of the microcapsules was investigated. Furthermore, analyses on the phase-change characteristics, thermal stability, ultraviolet aging, and solvent and acid–base resistances of the microcapsules were conducted systematically. Finally, a reversible thermochromic mark containing the RTPUU microcapsules was designed and fabricated, which could be used against falsification. Moreover, these RTPUU microcapsules can be potentially used for anticounterfeiting applications. [ABSTRACT FROM AUTHOR]

Owing to the high potential application need in the aerospace and structural industry for honeycomb sandwich composite, the study on the flexural behaviour of sandwich composite structure has attracted attention in recent decades. The excellent bending behaviour of sandwich composite structures is based on their facesheet (FS) and core materials. This research studied the effect of woven glass-fibre prepreg orientation on the honeycomb sandwich panel. A three-point bending flexural test was done as per ASTM C393 standard by applying a 5 kN load on different orientation angles of woven glass-fibre prepreg honeycomb sandwich panel: α = 0°, 45° and 90°. The results show that most of the sandwich panel has almost the same failure mode during the three-point bending test. Additionally, the α = 0° orientation angle shows a higher maximum load prior to the first failure occurrence compared to others due to higher flexibility but lower stiffness. In addition, the woven glass-fibre prepreg orientation angle, α = 0°, has the maximum stress and flexural modulus, which directly depend upon the maximum load value obtained during the flexural test. In addition, the experimental results and analytical prediction for honeycomb sandwich deflection show good agreement. According to the result obtained, it is revealed that woven glass-fibre honeycomb sandwich panels with an α = 0° orientation is a good alternative compared to 45° and 90°, especially when better bending application is the main purpose. The final result of this research can be applied to enhance the properties of glass-fibre-reinforced polymer composite (GFRPC) cross-arm and enhance the existing cross-arm used in high transmission towers. [ABSTRACT FROM AUTHOR]

Au decorated with type I collagen (Col) was used as a core material to cross-link with stromal cell-derived factor 1α (SDF1α) in order to investigate biological performance. The Au-based nanoparticles were subjected to physicochemical determination using scanning electron microscopy (SEM), dynamic light scattering (DLS) and ultraviolet–visible (UV-Vis) and Fourier-transform infrared spectroscopy (FTIR). Mesenchymal stem cells (MSCs) were used to evaluate the biocompatibility of this nanoparticle using the MTT assay and measuring reactive oxygen species (ROS) production. Also, the biological effects of the SDF-1α-conjugated nanoparticles (Au-Col-SDF1α) were assessed and the mechanisms were explored. Furthermore, we investigated the cell differentiation-inducing potential of these conjugated nanoparticles on MSCs toward endothelial cells, neurons, osteoblasts and adipocytes. We then ultimately explored the process of cell entry and transportation of the nanoparticles. Using a mouse animal model and retro-orbital sinus injection, we traced in vivo biodistribution to determine the biosafety of the Au-Col-SDF1α nanoparticles. In summary, our results indicate that Au-Col is a promising drug delivery system; it can be used to carry SDF1α to improve MSC therapeutic efficiency. [ABSTRACT FROM AUTHOR]

The use of composite conical shell structures across the globe in various applications concentrates on nose cones and incredibly complex vehicle components in the aerospace and automotive industries. This work investigates the free vibration analysis of laminated conical shell (LCS) and sandwich conical shell (SCS) structures with various foam cores. The sandwich construction is fabricated using the hand layup technique. The vibration characteristics of the fabricated LCS and SCS specimens are validated with the Finite element software (ANSYS). Very minimal variation was observed between the experimental and numerical simulations. The various parametric analyses were also studied for the LCS and SCS with length, ply orientation, and boundary conditions. Further, for SCS, vibration behaviors across multiple core materials and core thickness were also investigated. [ABSTRACT FROM AUTHOR]

Atomistic simulations of quasi-static compression and tension of linear arrays consisting of hybrid spherical nanoparticles (NPs) with Si cores and 6H-SiC partially overlapped shells are performed to reveal the effect of the shell thickness on the deformation mechanism and mechanical properties of such NP arrays. The overlapped shells are considered as a model of a continuous coating that promotes the mechanical integrity of a nano-powder and transforms it into a porous composite material. At compression, the transition from ductile to brittle deformation behavior with increasing shell thickness is observed. The compression of a NP array with thick shells induces the formation of a quasi-conical slip surface. The fracture of a NP array at compression involves the fracture of both shell and core materials and can induce the formation of a new β -Sn phase in the Si core. At tension, the deformation process is characterized by a relatively large proportional limit, and the fracture occurs in the weak cross sections at the necks between NPs, so that the NP cores remain intact after fracture. Before fracture, the largest microscopic stresses are observed in the shell material near the core-shell interface. The simulations predict a strong increase of modulus and strength at tension and compression with an increase in the relative shell thickness, the ratio of the shell thickness to the NP diameter, while the effect of the NP size on mechanical properties is relatively weak. This suggests that the relative shell thickness is the major similarity parameter that dominates the mechanical properties of the NP arrays. Interestingly, the simulations predict a larger modulus for NPs with thick shells compared to single-material SiC NPs. This points at a non-trivial role of the core-shell interface and the degree of the shell overlap in the load transfer in the arrays of NPs with overlapped shells. [ABSTRACT FROM AUTHOR]

High-quality geomagnetic measurements are widely used in both fundamental research of the magnetic field and numerous industrial applications. However, vector data measured by fluxgate sensors show a dependency on temperature due to sensitive coil core material and components of the sensor electronics. Here, we propose a new method for detecting and eliminating temperature dependence in magnetic observatory data. The method is designed to correct temperature drifts in variation vector magnetometer measurements when preparing quasi-definitive data according to an INTERMAGNET standard. A special feature of the method is the semi-automatic adjustment of localization intervals for temperature correction, which prevents boundary jumps and discontinuities in the course of sequential data processing over long intervals. The conservative nature of the approach implies the minimization of the original data amount subjected to correction. The described method is successfully applied in the routine monthly preparation of quasi-definitive data of the Saint Petersburg Observatory (IAGA-code SPG) and can be efficiently introduced at other magnetic observatories worldwide. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the impact of jackfruit inner skin fibre (JS) incorporated with whey protein isolate (WPI) and soybean oil (SO) as a wall material for probiotic encapsulation to improve probiotic stability against freeze-drying and gastrointestinal (GI) tract conditions. Bifidobacterium bifidum TISTR2129, Bifidobacterium breve TISTR2130, and Lactobacillus acidophilus TISTR1338 were studied in terms of SCFA production and the antibiotic-resistant profile and in an antagonistic assay to select suitable strains for preparing a probiotic cocktail, which was then encapsulated. The results revealed that B. breve and L. acidophilus can be used effectively as core materials. JS showed the most influential effect on protecting probiotics from freeze-drying. WPI:SO:JS at a ratio of 3.9:2.4:3.7 was the optimized wall material, which provided an ideal formulation with 83.1 ± 6.1% encapsulation efficiency. This formulation presented > 50% probiotic survival after exposure to gastro-intestinal tract conditions. Up to 77.8 ± 0.1% of the encapsulated probiotics survived after 8 weeks of storage at refrigeration temperature. This study highlights a process and formulation to encapsulate probiotics for use as food supplements that could provide benefits to human health as well as an alternative approach to reduce agricultural waste by increasing the value of jackfruit inner skin. [ABSTRACT FROM AUTHOR]

A new type of composite insulated concrete sandwich (ICS) wall is proposed. The wall consists of a three-dimensional spatial steel wire mesh skeleton, insulating core material and inner and outer concrete layers, all of which form a synergistic composite wall panel to work as the main stress-bearing member in the construction of multistorey high-rise buildings. To analyse the mechanical properties of the wall body, its failure mode was investigated. The wall's hysteresis curve, strength, stiffness and deformation were all analysed through a low reversed cyclic load test on two specimens, followed by an evaluation of its seismic performance. The deformability, failure mode, strain and ultimate bearing capacity of the specimens under the action of axial compression were also studied through an axial compression test on three specimens. The hysteresis test indicated that, in comparison with an ordinary shear wall, the ICS wall, connected through effective construction measures, had superior overall working performance under the same reinforcement ratio and its ductility and energy-dissipating capacity were improved. The results of the axial compression test also confirmed that the ICS wall had excellent axial compressive resistance, bending and deformation resistance, and high stability. [ABSTRACT FROM AUTHOR]

In the present study, the experimental data of a shot-peened (TiB + TiC)/Ti–6Al–4V composite with two volume fractions of 5 and 8% for TiB + TiC reinforcements were used to develop a neural network based on the deep learning technique. In this regard, the distributions of hardness and residual stresses through the depth of the materials as the properties affected by shot peening (SP) treatment were modeled via the deep neural network. The values of the TiB + TiC content, Almen intensity, and depth from the surface were considered as the inputs, and the corresponding measured values of the residual stresses and hardness were regarded as the outputs. In addition, the surface coverage parameter was assumed to be constant in all samples, and only changes in the Almen intensity were considered as the SP process parameter. Using the presented deep neural network (DNN) model, the distributions of hardness and residual stress from the top surface to the core material were continuously evaluated for different combinations of input parameters, including the Almen intensity of the SP process and the volume fractions of the composite reinforcements. [ABSTRACT FROM AUTHOR]

Research studies investigating the possibility of using 5 new core material (other than polystyrene) in concrete sandwich panels are being reported in the literature. Though several alternate core materials are suggested in the literature, not many would improve the fire-resistance property of the sandwich panels. Towards addressing this issue, in this paper, a lightweight pervious concrete core is proposed as a new alternative. Experimental studies were conducted to determine the flexural behavior of sandwich panels with pervious concrete core. The flexural behaviour was investigated under threepoint and four-point bending conditions. The geometrical variables considered were core thickness and a number of shear connector lines. The variables considered were found to influence the initial stiffness, cracking moment, ultimate moment, load-deflection behaviour and load-strain behaviour of the panels. Test results showed that, sandwich panels without shear connector trusses failed due to the separation of wythes, and the panels with shear connector trusses achieved composite action. An analytical study indicated that the equation given in ACI 318 underestimated the strength of the tested panels. The equation has to be modified by explicitly including the shear connector details in the equation for predicting the flexural strength with reasonable accuracy. Further experimental and analytical studies on prototype concrete sandwich panels with pervious concrete core produced using lightweight aggregates are required in view of developing design guidelines for practical applications. [ABSTRACT FROM AUTHOR]

Native potato clones grown in Peru contain bioactive compounds beneficial to human health. This study aimed to optimize the spray-drying nanoencapsulation of native potato phenolic extracts utilizing a central composite design and response surface methodology, obtaining the optimal treatment to an inlet temperature of 120 °C and an airflow of 141 L/h in the nano spray dryer B-90, which allowed maximizing the yield of encapsulation, antioxidant capacity (DPPH), encapsulation efficiency (EE), total phenolic compounds, and total flavonoids; on the other hand, it allowed minimizing hygroscopicity, water activity (Aw), and moisture. Instrumental characterization of the nanocapsules was also carried out, observing a gain in lightness, reddening of the color, and spherical nanoparticles of heterogeneous size (133.09–165.13 nm) with a negative ζ potential. Thermal, infrared, and morphological analyses confirmed the encapsulation of the core in the wall materials. Furthermore, an in vitro release study of phenolic compounds in an aqueous solution achieved a maximum value of 9.86 mg GAE/g after 12 h. Finally, the obtained nanocapsules could be used in the food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Aerogel is currently known to be one of the ideal core materials for vacuum insulation panels. The thermal performance of aerogel is discussed in detail. Thermal performance of nan-aerogel is sharply affected by its nanostructure. The nanostructure model of aerogel was reframed by the random generation method (RGM). A developed Lattice Boltzmann method (LBM) for predicting the effective thermal conductivity (ETC) of nano-granular materials was proposed. The accuracy of the method was experimentally verified. The results revealed that the simulation results and experimental data were in excellent accordance, which indicated, the method could be introduced for predicting the ETC of granules. The effects of granule diameter, internal pressure and density on ETC were analyzed in detail. Additionally, it was readily possible for granular porous material with a small diameter to keep a low ETC under high pressure. The ETC of aerogel increases rapidly versus temperatures increasing, particularly at high temperatures. In addition, an optimal density value of about 120 kg/m3 was recommended for maintaining low thermal conductivity. It was also found that there existed an optimal doping content that can minimize the ETC of aerogel. [ABSTRACT FROM AUTHOR]

Core-shell particles have been extensively used to toughen thermal plastic polymers, in which the core is composed of different thermal plastic polymers such as polypropylene (PP), polyethylene (PE), polystyrene (PS), et al, whereas the shell is composed of rubber or elastomer. However, how the core mechanical properties affect the toughness of core-shell particles toughened polymers has remained unclear up to now. In this article, five kinds of polyethylene (PE) were used to in situ prepare PE-ethylene propylene rubber (EPR) core-shell particles toughened polypropylene (PP) composites. The results show that the PE cores can be yielded during ductile fracture, and the higher the yield stress of PE, the higher the impact toughness is. The notch impact strength increases from 39.2 to 56.7 kJ/m2 with increasing PE yield tress from 10.0 to 28.5 MPa for the composites when the content of PE and PE-EPR core-shell particles in the PP matrix is fixed at 20 wt%. Moreover, it can be well interpreted that the notch impact strength of PP-EPR core-shell particles toughened PP composites is obviously higher than that of PE-EPR core-shell particles toughened PP composites produced by ExxonMobil Chemical Co. because the yielding stress of PP is higher than that of PE [1]. Furthermore, the results show that the notch impact strength increases with increasing PE content. However, excess PE can induce the transition from ductile to brittle fracture of the composites, resulting in a sharp drop in toughness. However, this transition is determined by the modulus rather than the yield stress of the core material. [ABSTRACT FROM AUTHOR]

Polyamide 12 (PA12) is a core material in many 3D-printing techniques, including selective laser sintering (SLS), and its mechanical characterization helps to better understand behaviors of additively manufactured parts made from this polymer. In this paper, the elastic response of SLS-produced PA12 is shown to be nonlinear. Standard test samples with different orientations with regard to the scanning direction are 3D-printed with the use of PA2200 powder, and their elastic response is investigated under uniaxial tension at different strain rates. Mooney–Rivlin hyperelastic models are proposed to address the observed nonlinear elasticity of the samples. Cyclic response of the specimens is shown to be stabilized after a few transient cycles so the material parameters are determined for trained samples after shakedown in their response. The obtained parameters are found to depend on the loading speed; thus, a rate-dependent hyperelastic constitutive model is presented for PA12 produced by selective laser sintering. This model is validated by comparing its numerical prediction with empirical responses under simple tension tests. [ABSTRACT FROM AUTHOR]

Quantum dots have received great interest due to their excellent optoelectronic properties. However, the surface defects of quantum dots affect the carrier transport and ultimately reduce the photovoltaic efficiency. In this paper, a core–shell quantum dot by hot‐injection method is prepared to grow a narrow‐band semiconductor layer (CuInSe2 (CISe) quantumdot) on the surface of a broad‐band core material (cadmium sulfide (CdS) nanocrystal). The composition, structure, optical properties, and decay lifetime of CdS/CISe core–shells are investigated in more detail by X‐ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL), UV–vis spectrophotometry, and fluorescence spectroscopy. The CdS/CISe core–shell structure has a broadened absorption range and still shows CISe‐related quantum effects. The increased size of the core–shell and the smaller specific surface area of the CISe shell layer lead to a lower carrier complexation chance, which improves the carrier lifetime. [ABSTRACT FROM AUTHOR]

This study focuses on the buckling behavior of composite microshells inside pacemakers to select the most durable material. Due to the strong electromagnetic forces encountered by pacemaker microshells, comprehensive research is needed to identify suitable materials. This study analyzes the buckling behavior of a porous sandwich cylindrical microshell attached to electrodes, which is supported by an elastic foundation and reinforced with functionally graded carbon nanotubes. Three porosity models are considered for the core material, and the equilibrium equations are derived using Hamilton's principle based on third order shear deformation theory. This study compares the critical buckling loads with those from the literature and examines the effects of various parameters, such as thickness stretching and non-stretching. The findings indicate that the thickness stretching effect has a significant influence on the critical buckling load. In addition, a lower functionally graded power index and higher porosity volume fraction result in higher critical buckling loads. These results are relevant for micro-electromechanical systems and can aid in the selection of appropriate materials for pacemaker microshells to improve their durability and performance. [ABSTRACT FROM AUTHOR]

Can immersive virtual reality (IVR) serve as an effective venue for learning and training? The promise of learning in IVR lies in its affordances for motivating learners to engage in generative processing (i.e., cognitive processing aimed at making sense of the material). The pitfall of learning in IVR is that it can distract learners so they engage in extraneous processing (i.e., cognitive processing that does not support the instructional goal). This paper reviews (1) media comparison research we have conducted on the effectiveness of learning academic content and skills in IVR versus learning with conventional media and (2) value-added research we have conducted concerning which features can improve the instructional effectiveness of learning in IVR. The paper includes implications for practice and for further work in the area. Overall, the paper focuses on the challenges associated with determining how to reduce the distracting aspects of IVR, maintain the motivating aspects of IVR, and guide the learner towards the core instructional material. [ABSTRACT FROM AUTHOR]

Purpose: To compare and evaluate the effects of different indirect composite onlay and/or core buildup materials on the fracture resistance and fracture mode of restored endodontically treated premolars. Methods: Two conventional handmade indirect composite resins (SR Nexco (NC) and Ceramage (CM)) and two core buildup materials, dual-cure composite resin (MultiCore Flow (MC)), and short fiber-reinforced composite resin (EverX Posterior (EXP)), were selected. Sixty maxillary premolars were randomly divided into six groups (n=10). Group 1 included intact teeth (INT; positive control). Mesio-occluso-distal cavity preparation and endodontic treatment was performed on the remaining premolars. Group 2 was restored with polymer-reinforced zinc oxide eugenol intermediate restorative material (IRM; negative control), whereas the experimental groups (groups 3-6) were restored with core buildup material and indirect composite onlay (MC_NC, MC_CM, EXP_NC, and EXP_CM). The specimens received compressive loading using a universal testing machine, at 45° to the long axis with a crosshead speed of 0.5 mm/min until fracture. Fracture modes were visually analyzed. Fracture resistance was measured and statistically analyzed using two-way and one-way ANOVA (a=0.05). Results: Only the type of indirect composite onlay affected the fracture resistance of the experimental groups (P=0.009). The MC_CM group showed the highest fracture resistance, which was significantly higher than that of the MC_NC group (P=0.031). No statistically significant differences were found between the INT group and other experimental groups(P>0.05). All groups had a greater incidence of restorable than unrestorable failures. Conclusions: The type of indirect composite onlay affected the fracture resistance of restored endodontically treated maxillary premolars. [ABSTRACT FROM AUTHOR]

The utilization of a combination of soft and hard materials with a core shell morphology (CSM) represents a distinctive approach for harnessing the properties of a single material. This field has garnered significant attention over the past decade. Core shell systems based on polystyrene offer a remarkable amalgamation of a solid component (polystyrene) and a flexible organic polymer, thereby enhancing the potential for catalysis, biological applications, and environmental studies within the core shell system (CSS). Various configurations of polystyrene-based CSS have been extensively documented in existing literature. The structural design of CSS plays a pivotal role in determining its applicability, which is why a specific morphology is depicted for each unique application. This review provides a comprehensive overview of the latest advancements in the classification, synthesis, properties, characterization, and applications of polystyrene-based CSS. Additionally, it briefly discusses the recent developments in drug delivery, sensing, environmental studies, and catalysis involving polystyrene-based CSS over the past six years. [ABSTRACT FROM AUTHOR]

Based on self-healing technology of closed wall microcapsules in goaf, silicon carbide-phenolic resin (SiC-PF) microcapsules were prepared by in-situ polymerization with epoxy resin E-51 as core material and silicon carbide (SiC) doped phenolic resin as wall material. The microstructure and particle size distribution of the microcapsules were characterized by scanning electron microscopy (SEM) and laser particle size analyzer. The structure of the microcapsules was analyzed by Fourier transform infrared spectroscopy (FTIR). The thermal degradation behavior of the microcapsules was tested by thermogravimetric analyzer (TG). The nanoindentation instrument was used to analyze the capsule wall performance of the microcapsules, and the mass loss rate of the microcapsules was tested at room temperature. The results show that with the increase of SiC content, the particle size of SiC-PF microcapsules is uniform, the thermal stability is good, the performance of capsule wall is greatly improved, and the mass loss rate is small. The initial thermal decomposition temperature of 0.8SiC-PF microcapsules is increased to 279 °C, the carbon residue rate is 12.6%, the rupture load of the capsule wall is 95.49 mN, and the mass loss rate is 1.82% after 100 d at room temperature. The addition of SiC improves the particle shape, thermal stability, capsule wall characteristics and storage stability of PF microcapsules. [ABSTRACT FROM AUTHOR]

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This work presents a new approach to investigating water conduction properties in real three-dimensional (3D) voids of asphalt mixtures. Three different molding methods were employed for the same grade of asphalt mixture, and the three asphalt mixture specimens were scanned using X-ray Computerized Tomography (CT) to identify the real 3D void structure distribution inside the mixture. The real 3D behavior of void moisture conduction inside the mixture was simulated using the discrete lattice Boltzmann method and the BGK collision model. Three different molding methods were used to study the behavior of mesoscopic seepage inside the specimen. The results show that water conduction varies substantially in real 3D voids inside diverse molded objects. Regardless of flow and flow velocity, the Superpave Gyratory Compactor (SGC) method is extraordinarily close to the conduction qualities of the actual field core material. It shows that the Marshall molding method is inconsistent with the actual pavement molding method, and the SGC method can not only ensure that the reasonable void ratio is conducive to the thermal expansion and cold shrinkage space of the asphalt mixture but also prevents rainwater from entering the asphalt mixture. This work provides a new perspective for the study of water damage resistance and medium transmission characteristics of asphalt mixtures. [ABSTRACT FROM AUTHOR]