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Organic pigments generally have bright colors but poor ultraviolet (UV) resistance. To improve the UV resistance and extend the applications, a core-shell composite pigment with rutile TiO2 intensification for UV inhibition is proposed by a facile sol-gel method in this work. A core-shell structure, with a homogeneous sol-gel TiO2 shell containing additional nanosized rutile TiO2 particles and with the pigment as the core, was established taking advantage of UV resistance of TiO2 and binding ability of sol-gel. While the sol-gel TiO2 shell alone has already shown obvious ultraviolet shielding effect, as tested over different sol-gel aging times and TiO2 loadings, the UV resistance of the fluorescent pigments was further enhanced by binding the nanosized rutile TiO2 in the sol-gel shell. At a sol-gel TiO2 to rutile TiO2 ratio of 2:1, the UV exposure time is extended about eight times compared with that of the original pigment and twice as that of the modified pigment with pure sol-gel TiO2 for the same color change. Therefore, the novel core-shell composite pigment intensified with nanosized rutile TiO2 particles is proved to be efficient in improving the UV resistance of organic pigments.

Fatigue damage accumulation is a critical factor resulting in the failure of prestressed concrete (PC) bridges. The fatigue damage is usually caused by the coupled effect of cyclic vehicle loading and environmental corrosion. This study investigated probabilistic fatigue damage on aging PC bridges considering both stochastic traffic loading and corrosion. A stochastic traffic model was derived based on long-term monitoring data aiming to simulate fatigue stress spectra of critical rebar. The effect of cracks on the fatigue stress spectra was investigated in order to model the fatigue stress state more realistically. A three-stage traffic growth model was established based on traffic volume histories of three highways in China. A fatigue limit state function considering traffic growth and corrosion effect was deduced for fatigue reliability assessment of PC bridges. Numerical results show that the stress amplitude of rebar considering cracks is 1.53 times greater than the rebar with no-cracks, resulting in a decrease of fatigue life by 68 years. In addition, the three-stage traffic growth models lead to 25 years shorter fatigue life than the one considering a linear traffic growth model. Finally, the corrosion effect results in a fatigue life of 44 years. The numerical results provide a theoretical basis for fatigue life estimation and maintenance of aging PC bridges.

The demand for transportation diesel fuels has been increasing in most countries for the last decade. As is one of the primary sources for diesel distillates, light cycle oil (LCO), having the advantages of inheriting similar density and boiling point range to diesel fuels, but high contents of aromatics, sulfur, and nitrogen, needs to be upgraded before being utilized. This work reports a trinary porous SiO2–Al2O3–TiO2 (SAT) synthesized by sol–gel method and used as the NiMo catalyst support for the LCO hydro-upgrading. NiMo/Al2O3-zeolite (AZ) was used as a reference to evaluate the performances of the NiMo/SAT. The catalysts were characterized by XRD, BET, Pyridine-FTIR, and TEM; and evaluated in a 20-mL fixed-bed microreactor using a Fluid Catalytic Cracking LCO as feedstock. It was found that the SAT support possessed a high surface area, high pore volume, and good acid properties. The NiMo/SAT catalyst exhibited even better hydrodesulfurization, hydrodenitrogenation, and hydrodearomatization performances than NiMo/AZ when the reaction was performed at 375 °C and 1100 psi. Compared with the zeolite addition catalyst, the SAT catalyst has the advantages of simple synthesis procedures and low input cost.

The stability of catalyst is of great importance for a long-term operation. In this paper, the hydrodesulfurization stability and deactivation mechanism of unsupported nano MoS2 catalyst was examined with light cycle oil as feedstock under an extreme hydrotreating condition for 160 h. A typical supported catalyst was also studied for comparison purpose. The results show that the activity of nano MoS2 can be well maintained after initial deactivation in the first 60 h time-on-stream. Less coke was found on spent nano MoS2 than on the spent supported catalyst, though coke deposition is identified as the main cause of deactivation for the nano catalyst. Without acidic supports, only soft coke is formed on the surface of catalyst. Unlike the supported catalyst, decomposition of active phase played a minor role in the deactivation of nano MoS2.

Background: Fusion with a titanium mesh cage (TMC) has become popular as a conventional method after cervical anterior corpectomy, but postoperative TMC subsidence has often been reported in the literature. We designed a novel anatomic cervical TMC to reduce the postoperative subsidence rate. This finite element study aims to investigate the anti-subsidence performance of a novel anatomic TMC and provide a theoretical basis for clinical application. Methods: According to the test process specified in the ASTM F2267 standard, three-dimensional finite element analysis was used to compare the anti-subsidence characteristics of a traditional TMC (TTMC) and novel TMC (NTMC). Abaqus software was used for the mesh, and the modulus of elasticity, Poisson's ratio and other material coefficients of each part were input into the model. Solidworks software was used to establish the TTMC and NTMC models and construct the two three-dimensional finite element models of TMC subsidence testing mentioned above. Through analysis, the relationships between the stiffness of the intervertebral body fusion device (Kd) and the stiffness of the polyurethane foam blocks (Ks) of the TTMC and NTMC were derived, respectively. Results: After fitting the linear segment, the Kd values of the TTMC and NTMC were 37314 N/mm and 89124 N/mm, respectively. After calculation, the Ks values of the TTMC and NTMC were 653.83 N/mm and 995.95 N/mm, respectively. The Kp values of the TTMC and NTMC were calculated to be 665.5 N/mm and 1007.2 N/mm according to the formula. Conclusion: The reported novel anatomic titanium mesh cage (NTMC) significantly improved the anti-subsidence performance after ACCF, which was approximately 51.3% higher than that of the traditional titanium mesh cage.

There is an increasing interest to enhance resistance to pathogens on the powder-coated surface. Traditional silver antimicrobial agents are hard to endure high curing temperature and lead to the yellowness of the surface appearance. Commercial sources usually cut down silver loading (less than 2.5w%) to avoid the color change and this will result in low inhibitory effect and poor durability. To improve the antimicrobial performance and maintain the appearance, Ag+, Cu2+, Zn2+ ternary inorganic antimicrobial agents on Linde A zeolite supports were prepared in this study. The silver content of this agent is increased to 8-10w% and the coated surface exhibits high antimicrobial efficiency. The coating appearance shows little adverse color change (∆E=1.47) when adding 2w% amount of agent. The reduction rate of this agent was over 99.99% after 6hrs for E. coli, S. aureus and C. albicans according to ASTM E2180-07 standard, and the paint film can maintain over 99% reduction rate even for 11 cleaning cycles. XP...

In this paper, a pair of rigid chiral D-A type enantiomers (S-/R-2) incorporating the pyrene moiety as the donor and 1,8-naphthalimide as the acceptor was chosen as circularly polarized electrolumi...

The development of lithium-sulfur batteries has been impeded by the shuttle effect and insulation of sulfur cathodes so far. Here we report a novel cathode consisting of a sulfur@TiO2/polypyrrole (S@TiO2/PPy) composite, in which sulfur is encapsulated by TiO2 hollow spheres and then loaded on a PPy nanowire matrix together. The S@TiO2/PPy cathodes for lithium-sulfur batteries deliver an excellent electrochemical performance with a high initial specific capacity of 1385.9 mAh g−1 at 0.2 C and a low decay rate of 0.047 % per cycle at 1 C. The enhanced property of S@TiO2/PPy composites maybe derived from a synergistic reaction on sulfur between TiO2 hollow spheres and conductive polypyrrole nanowires, which plays a vital role on inhibiting the shuttle effect and improving the conductivity of sulfur cathodes through encapsulating sulfur active materials, chemical adsorbing polysulfides and mixing the conductive component. The architectural design on S@TiO2/PPy cathodes will provide a promising route for the practical usage of lithium-sulfur batteries.

Air classifier mill (ACM) is widely used in powder coating and mineral comminution process. One of the problems typically presenting in ACM is over-grinding, which leads to high energy consumption and broad particle size distribution (PSD). To decrease the excessive amount of fine particles in the products, 6 configurations of grinding pins with ditches in the impact surface were used in the experiments. The width and depth of ditches varied from 1.35 mm and 1 mm to 4.75 mm and 3 mm, respectively, while the interior angles in the ditches are the same. The particle size and PSD show that the ditches on the grinding pins have significant effect on the D10 values and the particle size span. The deepest and widest ditches (P4) result in largest D10 and smallest span in this study. The D10s of products ground by P4 increase by 24.1% for fine powder (D50 = 25 μm) and 16.0% for coarse powder (D50 = 33 μm), while the span decreases by 6.9% (D50 = 25 μm) and 6.4% (D50 = 33 μm) compared to regular cylindrical pins (PC), respectively. Meanwhile, it is found that the P4 configuration improves the energy utilization efficiency by 7.6% (D50 = 25 μm) and 3.4% (D50 = 33 μm), compared to that of the original PC pins.

With the development of material engineering and coating industries, superhydrophobic coatings with exceptional water repellence have increasingly come into researchers’ horizons. The superhydrophobic coatings with corrosion resistance, self-cleaning, anti-fogging, drag-reduction, anti-icing properties, etc., meet the featured requirements from different application fields. In addition, endowing superhydrophobic coatings with essential performance conformities, such as transparency, UV resistance, anti-reflection, water-penetration resistance, thermal insulation, flame retardancy, etc. plays a remarkable role in broadening their application scope. Various superhydrophobic coatings were fabricated by diverse technologies resulting from the fundamental demands of different fields. Most past reviews, however, provided only limited information, and lacked detailed classification and presentation on the application of superhydrophobic coatings in different sectors. In the current review, we will highlight the recent progresses on superhydrophobic coatings in automobile, marine, aircraft, solar energy and architecture-buildings fields, and discuss the requirement of prominent functionalities and performance conformities in these vital fields. Poor durability of superhydrophobic coating remains a practical challenge that needs to be addressed through real-world application. This review serves as a good reference source and provides insight into the design and optimization of superhydrophobic coatings for different applications.

Highlights • Nanosilver-incorporated additive increases the antimicrobial durability. • Nanosilver modified by α-lipoic acid is tightly fixed on carrier. • Hydrophilic polymer encapsulation protects Ag+ and promotes nanosilver oxidation. • Complementary effect of Ag+ and nanosilver enhance instant activity and durability. • High silver loading additive with acceptable visual appearance., Applying silver into coatings has become a prevalent method in fabricating antimicrobial surfaces. However, the concerns about durability always exist and limit its applications. Here, a highly inhibitory, active, durable, and easy-to-use silver ions-nanosilver antimicrobial additive for powder coatings was fabricated in this study. Silver nanoparticles were chemically bonded to the Ag, Cu, and Zn-ternary ion-exchanged zeolite by α-lipoic acid, which was then encapsulated by hydrophilic polymers. The fabricated silver ions and silver nanoparticles (Ag+-AgNPs) complementary structure provides a synergistic effect. Ag+ is the main antimicrobial agent, while AgNPs act as a supplementary reservoir of Ag+. As well, the formed thin layer of silver nanoparticles and hydrophilic film prolongs the release of active Ag+ from zeolite, and Ag+ facilitates the activation of AgNPs. The results show that this additive indicates excellent antimicrobial activity to E. coli, S. aureus, P. aeruginosa, and C. albicans, and that the coatings with the additive exhibit over 99.99% reduction rate for the tested bacteria and fungi. The coating film is able to maintain over 99% antimicrobial reduction even after 1200 repeated solution wipings, or over 30 wash cycles of artificial sweat solution, indicating high durability. Furthermore, the yellowness of the coating is not evident (Δb

Fumed silica is one of the most commonly used flow additives in the powder coating industry. To investigate the influence of the properties of fumed silica on powder coatings, three different types of fumed silica, Aerosil R812, R972, and R8200, were selected and introduced to an ultra-high-gloss powder paint by the dry-blending method with preset mixing conditions and times. Their effect on the powder flowability, coating application related properties and film properties were carefully studied. The angle of repose (AOR) and bed expansion height data, which represent the semi-dynamic and dynamic flowability of powders respectively, show a strong flowability enhancement for the powders with additives, and R812 exhibits the best performance compared to 8200 and R972, mainly due to its high hydrophobicity and specific surface area. For the ultra-high-gloss powder paint, all the flow additives cause slight gloss reductions, surface roughness increase and a significant effect on the distinctness of image (DOI). The addition of R972 is beneficial to the transfer efficiency of powders compared with the other two, while the additives impose only a minor influence in the Faraday cage effect. The melting and curing dynamics, i.e., gel time, and inclined plate flow, are not affected by the flow additives.

This study presents a crack propagation stochastic process model for orthotropic steel deck (OSD) based on the structural health monitoring (SHM) data. An inhomogeneous compound Poisson pr...

We studied the key characteristics of a novel silk yarn reeled from fresh cocoons. Compared with traditional silk yarn, this novel silk yarn displayed better mechanical properties, especially in terms of a higher breaking stress and toughness, and exhibited a different surface morphology. A cross-sectional observation and the sericin content results illustrated that different sericin coatings on the silk yarn reeled from fresh cocoons surface did not improve the mechanical properties. The degumming and tensile testing analysis indicated that degummed silk fibroin of novel silk yarn is able to resist deformation and fracture better than silk fibroin of traditional silk yarn. The FTIR results revealed that the selected techniques is an important contributor to the silk fibroin mechanical properties, because novel technique brought higher percentage beta-sheet structures in novel silk yarn fibroin than traditional silk yarn. The new technique that using novel silk yarn has improved its mechanical properties and it is expected that the silk yarn with superior mechanical properties could be used in fabrics transistors, electrodes and reinforced biomaterials.

In this paper, different microchips were simulated by the finite element method (FEM) with the aim to clarify the effect of topological parameter on inactivating microorganisms vaccinated in blueberry juice under low voltage for 50–250 μs and 20–100 pulses. For the planar comb teeth microchips in the first generation, only a 1.01 log 10 of Escherichia coli ( E. coli ) was achieved at 25 °C in all the solutions, then, with the aim to obtain a more uniform electric field distribution, an interdigitated electrode structure are used in the second-generation microchip which improved the inactivation effect of E. coli up to 2.85 log 10 reduction. At the end, by considering the problems presented by the two aforementioned microchips, the structure of a parallel plate as the third-generation microchip was designed and the best experimental platform was built. This microtreatment chamber exhibited excellent inactivation effect on E. coli , Saccharomyces cerevisiae , and Staphylococcus aureus of 5.32, 5.42, and 4.77 log 10 cycles respectively. These results will provide a meaningful guidance in inactivate microorganisms by low-voltage PEF.

A new fatigue reliability assessment function which takes into account the vehicle and temperature loadings has been developed in this study. The vehicle and temperature loadings are important parameters as they can cause fatigue failure of the welds in a steel box girder. The temperature affects the traffic loading effect by changing the elastic modulus of asphalt pavement. The effect of the temperature difference has been considered based on the measured data and the finite element analysis. Linear regression equations between the equivalent stress and the temperature for different vehicle types have been developed. Using the thermal stress analysis and the rain-flow counting method, the temperature difference fatigue stress spectrum has been determined. Further, a limit equation for the fatigue reliability assessment, which takes into account both the vehicle and temperature loadings, has been developed. Finally, the effects of the temperature and the traffic growth rate on the fatigue reliability of two welding types of Nan-xi Yangtze River Suspension Bridge have been assessed.

Waste cooking oil (WCO) hydrotreating to produce green diesel is good for both the environmental protection and energy recovery problems. The roles of catalyst support and reaction temperature on reactions during WCO hydrotreating process were evaluated over an unsupported and a commercial sulfided cobalt and molybdenum (CoMoS) catalyst supported by a mixture of Al2O3, TiO2, and SiO2. The presence of catalyst support helped to improve the dispersion and enlarge the surface area of CoMoS, and was found to be a key factor in reducing reaction temperature, in enhancing the hydrodeoxygenation (HDO) and hydrogenation capabilities, and in decreasing polymerization capability. The increase of reaction temperature strongly improved the deoxygenation, hydrogenation, and cracking reaction activities. Compared to the unsupported CoMoS, the supported one exhibited good deoxygenation and hydrogenation capabilities at 340 &deg, C in WCO hydrotreating to produce diesel fraction, however, high temperature operation needs to be carefully controlled because it may cause overcracking and dehydrogenation.

Ultrafine powder coatings are one of the development directions in the powder coating industry, as they can achieve thin coatings with good leveling and high surface smoothness comparable to liquid coatings. Compared to regular coatings, they experience a higher sensitivity to any incompatibilities, e.g., filler from coating components. The properties of fillers play a great role in the performance of coating films. Aluminum trihydrate (Al(OH)3) is a well-known filler in solvent-based coatings and other polymer industries. To study and evaluate the performances of Al(OH)3 in ultrafine powder coatings, a popular filler, barium sulfate (BaSO4) is used for comparison. Both fillers are added in ultrafine powder coatings based on two of the most commonly used resin systems (polyester-epoxy and polyester). The differences of physical and chemical properties between both fillers have significant influences on several properties of powder paints and coating films. The polar groups (hydrogen bond) in Al(OH)3 result in the strong interaction between inorganic filler and organic polymer matrix, thus decreasing the molecular network mobility and influencing the chain formation, which is verified by differential scanning calorimetric (DSC). The bed expansion ratio (BERs) of powder paints incorporated with Al(OH)3 are much higher than those with BaSO4, which indicate more uniform gas-solid contact during the spraying process. Samples with Al(OH)3 exhibit much lower specular gloss at 60&deg, which are expected to achieve remarkable matting effects. Superior corrosion resistances can be observed for almost all the coated panels incorporated with Al(OH)3 in contrast to those with BaSO4. Other aspects are slightly influenced by the difference between the two fillers, such as the angle of repose values (AORs) of powder paints, the impact resistance and flexibility of coating films.

Metallic pigmented powder coating, composed of metallic pigments and coating particles, provides coatings with metal shine and functional protection, while causes much less emission of organic solvents, unlike the traditional paint. The greatest challenge of the manufacturing step is binding the two incompatible ingredients together. However, the present industrial binding method, thermal bonding, has some inherent issues, such as pre-curing, pigment bending and high-temperature bonding. Hence, in the present work, a novel approach, microwave bonding, was studied and tested to address these shortcomings. Aluminum flakes were bonded with three types of powder coatings: polyester, hybrid, and polyvinylidene fluoride (PVDF). Microwave bonding shows a more stable metal shine over the non-bonding, obtains a lower bonding temperature than the glass transition temperature, and has a much higher heating rate ( ∼ 17 °C/min) over the thermal bonding method. Therefore, microwave bonding is trusted to have great potential to produce coatings with highly stable metal shine efficiently.

In order to improve photoelectric conversion efficiency of Sterling generate system, a linear magnetic-geared generator first used in the system is proposed. Its low-speed mover is coupled to Sterling engine to get drive speed, while two sets of permanent magnet, which function as the high-speed mover and the translator of the generator respectively, are integrated into a tubular iron core. As a results, the generator can get higher move speed to generate higher voltage, so as to improve system's photoelectric conversion efficiency. Its working principle, characteristic and performance are analyzed by using finite element method. The results fully verified the correctness of the design.

This paper presents an experimental study conducted to characterize the effect of corrosion and sustained load on structural behavior of reinforced concrete (RC) beam. The effects of loading level on corrosion of reinforcing steel, the flexural deflection and residual loading capacity of the test beams were investigated. In the first scenario, two non-corroded beams were tested to determine the maximum load levels that were required by the beams to reach their deflection limits and that were also tested for the sustained levels of the applied loads. For the second experiment, the corrosion was accelerated through the application of external direct current whilst the beams were under the load equivalent to 0%, 50%, 65% and 80% of the ultimate load. The results indicate that load levels have a significant effect on the rise of steel corrosion level, the decrease of flexural stiffness and the degradation of flexural capacity. The mechanical properties like the strength and ductility are significantly impaired due to simultaneous effect of loading and corrosion in comparison to the effect of the single parameter at a time. Considering the corrosion situation of different position of steel bar, the formula of the ratios of the different position of steel bar corresponding with different sustained loading levels was given. An equation was deduced to calculate the flexural stiffness of corroded reinforced concrete and can be served as a reference for deflection calculation of corroded reinforced concrete beams.

Graphene is considered as an excellent reinforcement due to its excellent physical and mechanical properties. In this work, milling balls of small diameter were used to reduce the collision energy during the ball milling process, and graphene nanoplates (GNP) reinforced Al5083 alloy matrix composites were successfully fabricated by ball milling, hot pressing and hot extrusion. The microstructures of the ball-milled powders and GNP/Al5083 composites were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The results showed that the GNP could remain after ball milling. However, the Al4C3 phase was found in bulk GNP/Al5083 composites, suggesting that some of the GNP reacted with Al and formed Al4C3 during the consolidation process. Tensile tests revealed that both the yield strength and ultimate tensile strength of the 1.0 wt.%GNP/Al5083 composite were increased by 50% compared with pure Al5083 fabricated under the same procedure. The relevant strengthening mechanisms of the composites were discussed.

Al-matrix composites with different contents of core–shell structured B4Cp–Cu reinforcement were prepared by electrolessly coating Cu on B4Cp and hot sintering the mixture of B4Cp–Cu and Al powder. The influences of solution treatment on the microstructure and mechanical properties were investigated. The results showed that the initial Cu shell was changed into Al2Cu shell, and part of Cu was dissolved into the Al matrix after solution treatment at 540 °C. With increasing solution dwelled time, the yield strength, ultimate compressive strength and ductility were improved gradually. As compared with the pure B4Cp reinforcement, the introduction of core–shell structured B4Cp-Cu and subsequent solution treatment improved the mechanical properties of Al-matrix composite. The improvement of mechanical properties is attributed to the fact that the Al2Cu shell moderates the modulus mismatch and enhances the interface bonding between Al and B4Cp, and that heat treatment introduces solution strengthening of Cu element into the Al matrix.

Metallic pigmented powder coating, composed of coating powders and metallic pigments, has been drawing more attention and occupying more market share with more stringent environmental pressure on traditional metallic solvent paint. To overcome the shortcomings of the thermal bonding method that aims at bonding the two incompatible ingredients, a self-designed microwave bonding device was first developed and tested in the present work. Taking advantage of the heating-selectivity of the microwave, a lower bonding temperature was obtained when compared to the thermal bonding method. Also, through the analysis of bonding rate and color difference, a higher bonding quality and enhanced color stability were found. More bondings between coating particles and Al flakes were clearly observed by SEM and EDS in the microwave-bonded samples. The microwave bonding is proved to be a feasible and efficient method and thus the bonding device has great potential to replace the present bonding machine.

This paper focuses on the preparation of metallic pigmented powder coatings with high color stability via a self-designed microwave bonding device. With the increasing environmental regulation on the use of traditional metallic paint, there has been a corresponding interest in metallic pigmented powder coating, owing to its zero VOCs emission, high protective property as well as sparkling aesthetic appearance. metallic pigmented powder coatings are mainly composed of two non-compatible ingredients: base powder coating(s) and metallic pigment(s). Bonding the two kinds of materials together is an effective approach to eliminate their non-compatibility problem and ensure color stability. Here, a self-designed bonding device based on microwave heating was invented to bond metallic pigmented powder coatings. Furthermore, a direct and quantitative characterization method, ash test, was first used to reveal the bonding quality by analyzing the mass percentage of metallic pigment in the powders. A comprehensive investigation on non-bonded powder was performed as a control test. The microwave-bonded samples were prepared with the device at various temperatures and rotating speeds followed by evaluation with ash test. After microwave treatment, reliable bonding of base powder coating and metallic pigment were proved via a series of characterizations, such as ash test, SEM, EDS, optical observation and size analysis. Therefore, the microwave bonding method is trusted to be a feasible and effective production method of metallic pigmented powder coatings.

A GaN-based pin neutron detector with a 6LiF conversion layer was fabricated, and can be used to detect thermal neutrons. Measurement of the electrical characteristic of the GaN-based pin neutron detector showed that the reverse leakage current of the neutron detector was reduced significantly after deposition of a 6LiF conversion layer on the detector surface. The thermal neutrons used in this experiment were obtained from an 241Am–Be fast neutron source after being moderated by 100-mm-thick high-density polyethylene. The experimental results show that the detector with 16.9-μm thick 6LiF achieved a maximum neutron detection efficiency of 1.9% at a reverse bias of 0 V, which is less than the theoretical detection efficiency of 4.1% calculated for our GaN neutron detectors.

For cathodes in lithium-sulfur (Li–S) batteries, increasing research effort has been devoted to hollow-structured transition metal oxides to utilize their morphologies more efficiently and take advantage of their strong polar chemisorption of polysulfides. In this study, we synthesized a novel sulfur@carbon/Co3O4 (S@C/Co3O4) composite via encapsulation of sulfur by sericin-derived carbon/Co3O4 hollow microspheres. With a sulfur content of 67.3%, the synthesized S@C/Co3O4 composite cathode delivered a high initial specific discharge capacity of 1171.6 mAh g−1 at 0.2 C and excellent rate performance at current densities up to 4 C. It also exhibited excellent long-term cyclability over roughly 1000 cycles at 1 C and 2 C with low decay rates of 0.076% and 0.062%, respectively. The improved electrochemical performance of the S@C/Co3O4 composite mainly stems from strong polar chemisorption of polysulfides by Co3O4, the physical encapsulation sulfur by hollow spheres, and high electrical conductivity of sericin-derived carbon.

The optimization of catalyst synthesis conditions using traditional single factor method involves extensive experimental time and costs. To overcome the drawbacks, a uniform design method was applied in the hydrothermal synthesis of nano MoS2 catalyst. An optimal synthesis condition is reached with only a few trials. Catalyst synthesis temperature is reduced to 200 &deg, C. The catalyst synthesized at the screened condition shows high hydrotreating activities. The results conclude that the catalyst has thread-like slabs with a lattice structure that is less mature than fully developed MoS2. The characterization results indicate that the appearance of such structure may be due to the weak links of successive MoS2 nuclei. The high catalytic activity is a result of the layered structure and a significantly large number of defects on the slabs.

An efficient and simple method for preparing bonded metallic powder coating is in high demand in the paint manufacturing and application industries. The bonding purpose is to keep the mass percentage of metallic pigment consistent between the original and recycled coating powder, which aims at solving the problem of recyclability. One possible method capable of realizing this goal is using the binder to cohere metallic pigment with base particles through a cold bonding method. Through this approach, the pre-curing and high-reject-rate problems generally present in thermal bonding can be completely eliminated. In this paper, polyacrylic acid (PAA) and polyvinyl alcohol (PVA) are applied as binders for the bonding process. At various dosages of liquid binder and D.I. water, bonded samples with different bonding effect were prepared. Finally, a good bonding quality with the lowest variance between the mass concentrations of Al flakes in the original powder (before spray) and deposited powder (after spray) 2.94% with PAA as a binder and 0.46% with PVA as a binder was achieved. These results manifest that the cold bonding method is a green and simple approach for preparing the metallic powder coating.

This paper presents an experimental study that sought to characterize the effect of corrosion and fatigue load on the behavior of reinforcing steel bars. The surface profiles of corroded st...

In this study, Al84Ni8.4Y4.8La1.8Co1 particles reinforced Al-based composites were prepared by hot pressing sintering and subsequent hot extrusion. The glassy powders were produced by gas atomization and then employed to mechanical milling. After hot pressing sintering, the nano-scale intermetallic compounds precipitated from metallic glass matrix due to higher temperature than super-cooled liquid region. The mechanical properties of 2024 alloy were improved by addition of glassy particles. The ultimate compressive stress increased from 482 MPa for 2024 alloy to 545 MPa, 627 MPa and 735 MPa for composites with 20 w.t.% 40 w.t.% and 60 w.t.% glassy powders addition, respectively, together with considerable fracture strain ranging between 2.9% and 13.6%. And the mechanical properties could be predicted by using the Rule of Mixture, which predicts the mechanical properties of the bulks from the volume weighed average of the constituent properties.

Linear magnetic field modulation gear can effectively avoid vibration and noise and lubrication and maintenance problems in mechanical gear, Which can replace mechanical gear in linear motion. According to the working mechanism of traditional magnetic field modulation gear, a linear magnetic gear is designed, whose transmission ratio is 2.67. Its air-gap flux density and static thrust characteristics and dynamic thrust characteristics are calculated by using the finite element analysis method. The calculate results validate the correctness of the design. Based on the above, the influence of ferromagnetic ring's size and the air-gap width to the gear's static thrust is analyzed, and then we have found rules about the influence, which can provide basis in optimizing a linear magnetic gear design. At the last, optimize the relative width of ferromagnetic ring to 0.6 and the thickness to 3 mm, the air-gap width of high-speed side to 1.2 mm and low-speed side to 1 mm.

Temperature is a key factor in the hydrothermal synthesis of MoS 2 with high catalytic activity. In this paper, the effect of synthesis temperature (sTemp) and initial temperature (iTemp) was carefully investigated against catalyst crystal structure and hydrotreating activities. The synthesized nano-MoS 2 was extensively characterized and evaluated using light cycle oil. There is a minimum sTemp for the formation of crystalline MoS 2 . Temperatures lower than the minimal sTemp result in amorphous structures. Surpassing this temperature leads to crystallization which goes through different growth routes. Higher iTemp promotes fast nucleation and thus nuclei combination growth. This leads to shorter slabs with a larger degree of defects, and a higher hydrotreating activity. At lower iTemp, crystal tends to grow in a continous way, resulting in fewer defects. In this way, with the increased sTemp, crystallinity is enhanced and slabs are curved and shortened. Both effects lead to improved hydrotreating performances.

Clinical studies have revealed that maxillary molar mesialization could occur in physiological drifting and during orthodontic treatment. The straight wire appliance (SWA) using a continuous wire made of shape memory alloy (SMA) might result in an undesired maxillary molar mesialization or an anchorage loss in the initial aligning stage. Recent findings suggest that a maxillary molar tube including a –25° auxiliary tube might minimize this anchorage loss. It was theorized that this auxiliary tube serving as a reserved v bend could preclude the possibility of molar mesialization in SWA. This chapter introduces the clinical implications of this new appliance, called the PASS system. The archwire sequence for the PASS is similar to that of SWA, except that the –25° auxiliary tube is only used for SMA at the initial stage. The mechanical properties of various material types of archwires associated with the PASS system are reviewed. Analysis was completed on the interactions between the archwire and the PASS system, such as the stress-strain relationship and frictional forces. Both low-friction and distalization forces are revealed from our data.

Carbon nanotubes (CNTs) reinforced aluminum matrix composites were fabricated by mechanical milling followed by hot extrusion. The commercial Al-2024 alloy with 1% CNTs was milled under various ball milling conditions. Microstructure evolution and mechanical properties of the milled powder and consolidated bulk materials were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and mechanical test. The effect of CNTs concentration and milling time on the microstructure of the CNTs/Al-2024 composites was studied. Based on the structural observation, the formation behavior of nanostructure in ball milled powder was discussed. The results show that the increment in the milling time and ration speed, for a fixed amount of CNTs, causes a reduction of the particle size of powders resulting from MM. The finest particle size was obtained after 15 h of milling. Moreover, the composite had an increase in tensile strength due to the small amount of CNTs addition.

Aluminum trihydrate (ATH) is one of the most widely used fillers in solvent-borne coatings and polymer industries. To investigate its performance in powder coatings, four different pigment to binder ratios (P/B) were used in respect to different ATH concentrations in four most widely used resin systems (epoxy, epoxy-polyester, polyurethane and polyester). The angle of repose (AOR) and specific gravity of powder paints increase accordingly with ATH concentration. The mechanical properties, corrosion and UV resistance performances of coating films are enhanced or only slightly decreased with the addition of ATH. Pencil scratch hardness increase significantly with the increase of ATH content. Impact resistance decreases within 5% of the initial resistance at the maximum ATH loading. There is a slightly decrease in corrosion resistance performances of less than 2 mm of failure at scribe in all formulations. The incorporation of ATH has slight effect on the UV resistance performance of all the samples. Moreover, the matting effect of ATH is observed for all the resin systems, especially epoxy, with the specular gloss decreasing more than 70% at P/B of 0.75.

In this study ion beam sputtering deposition was used as a new surface formation technology for strengthening cam surface during the manufacturing process of indexing cam mechanism. Phase exchanging deformation can be avoided in this manufacturing process. Compared to surface quenching processes, the shape accuracy and dimension accuracy can be improved using this method. The microstructure and properties of TiAlN composite film deposited on the profile surface of a cam (made of AISI 1045 steel) by ion beam sputtering deposition were discussed. The microstructural characterizations were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is shown that the fundamental Bragg peak of {111} in TiAlN coatings increased with a bias voltage reduction. The grain size is about 1 μm. The friction coefficient was tested by a rotating wear tester at different loads and speeds. The minimum friction coefficient can be achieved at 0.187.

A series of superabsorbent polymer composites based on sericin hydrolyzed with alkaline protease (AP) were prepared by grafting with acrylic acid (AA) and acrylamide (AM). The properties of the superabsorbent polymers (SAP) by using hydrolyzed sericin with different amount of alkaline protease (nAPh-sericin) were compared. It was found that the polymer prepared from 5APh-sericin (the mass ratio of AP to sericin was 5.0 mg g−1) showed the highest graft percentage and water absorbency, this phenomenon may be attributed to the change of molecular weight of resulting sericin molecules. The molecular structure of the grafted polymers was proved by thermal gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) measurements. Comparing with PAA-AM (poly AA-co-AM) and 0APh-sericin/PAA-AM polymer, 5APh-sericin/PAA-AM polymer had the most excellent water retention capacity and enzyme degradability. The morphological features of the polymers with different drying methods were evidenced by SEM images. The water absorbencies of 5APh-sericin/PAA-AM polymer prepared with freeze-drying were 896 g g−1 in deionized water, 424 g g−1 in tap water, and 83 g g−1 in 0.9 wt% aqueous NaCl solution. POLYM. COMPOS., 35:509–515, 2014. © 2013 Society of Plastics Engineers

A novel silk fibroin spongy wound dressing (SFSD) incorporated with nano-Ag particles was prepared by coagulating with 1.25-5.0% (v/v) poly(ethylene glycol diglycidyl ether) (PGDE). The mechanical properties, moisture permeability and hygroscopicity of SFSD, and the nano-Ag release behavior from SFSD were evaluated. The results showed that the soft SFSD had satisfying tensile strength and flexibility, as well as excellent moisture permeability and absorption capability of wound exudates. The moisture permeability was 101 g/m(2) per h and the water absorption capacity of SFSD was 595.2% and 251.9% of its own weight in dry and wet states, respectively. The nano-Ag in the SFSD was released continuously at a relatively stable rate in PBS resulting in a remarkable antibacterial property. A rabbit model was used to dynamically observe the healing process of full-thickness skin defects. Full-thickness wounds were created on the dorsal side of rabbits, which were covered with SFSD and porcine acellular dermal matrix (PADM) for comparison. The mean healing time of the wounds covered with SFSD was 17.7 ± 2.4 days, significantly shorter than that with PADM. The histological analysis showed that the epidermal cell layer formed with SFSD was very similar to normal skin, suggesting that SFSD may provide a good component for the development of new wound dressings.

Infrared-to-ultraviolet upconversion luminescence agent Y2O3:Yb3+,Tm3+ was prepared by a combustion method using citrate as a fuel/reductant. The prepared sample was characterized by X-ray diffraction, SEM, and fluorescence spectrophotometer. Two unusual 1I6 → 3H6 (~297 nm) and 1D2 → 3H6 (~363 nm) emissions from Tm3+ ions were observed at room temperature under 980-nm laser excitation. The change of upconversion emission intensity depending on the Yb3+ concentrations was discussed. The results showed that modest Yb3+ doping could make the upconversion emission of Tm3+ intense, and high Yb3+ concentrations might lead to fluorescence quenching. Moreover, the influence of ultraviolet upconversion luminescence on the photodegradation of methyl orange aqueous solution under solar light irradiation in the presence of TiO2 catalyst doped with Y2O3:Yb3+,Tm3+ was also investigated. It was concluded from the experiment of this study that TiO2/Y2O3:Yb3+,Tm3+ composite had higher photocatalytic activity than pure TiO2 under solar light. This study would make TiO2 utilize sunlight more efficiently and accelerate the practical application of photocatalytic technology in water treatment region.

A novel composite heterojunction photocatalysts Sr(Zr 1−x Y x )O 3 /TiO 2 /CdS was prepared by sol-gel combustion method. Its photoatalytic properties under visible light were investigated through degradation of methyl orange. XRD, SEM, Uv-Vis and PL techniques were used to characterize the structure and optical properties of the sample. The results showed that the photocatalytic activity of prepared composite photocatalysts under visible light is 2.85 times of that of pure TiO 2 .

Bi4Ti3O12 thin films with bismuth-layered perovskite structure have been successfully fabricated by means of chemical solution decomposition (CSD) and characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV–vis spectrophotometry in this study. The photocatalytic activity of Bi4Ti3O12 thin films has been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the photocatalytic activity have been found. Moreover, it has been found that La-doping can improve the photocatalytic activity of Bi4Ti3O12 thin films and hinder the increase of crystallite sizes during calcination.

In this paper, a preparation of stimuli-responsive capsules based on aqueous microgels is described. Microgel particles act as stabilizers for oil-in-water emulsion and organize themselves on the surface of chloroform droplets containing the biodegradable polymer poly(4-hydroxybutyrate-co-4-hydroxyvalerate) (PHBV). After chloroform evaporation, composite capsules consisting of a thin PHBV wall with integrated microgels are obtained. Due to the presence of microgels acting as sensitive building blocks, the capsules respond to different stimuli (temperature, solvent concentration). Preliminary results indicate that the capsule dimensions and morphology can be tuned by microgel and PHBV concentration in water and chloroform, respectively.

Silk fibroin (SF) has been one of promising resources of biotechnology and biomedical materials due to its unique properties. Here, different sizes of porous tubular scaffolds were fabricated from a SF aqueous solution with the addition of poly(ethylene glycol diglycidyl ether) (PGDE). The scaffolds were generally flexible and transparent at the wet state with a pore size of 81-128 mum and porosity of 90-96%, depending on the concentrations of SF and PGDE. The mechanical properties measurement showed that the tubular SF scaffolds had satisfying tensile and compression properties, especially the excellent deformation-recovery ability. FT-IR spectra indicated that the SF in the tubular scaffolds was in a beta-sheet structure, and no PGDE characteristic band was observed, suggesting that the PGDE could be removed from the scaffolds by soaking in deionized water. The cell compatibility of scaffolds was evaluated, and no obvious cytotoxicity to mouse L-929 fibroblasts was detected.

Sillenite Bi12TiO20 thin films with high photocatalytic activity have been successfully fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, energy-dispersive spectroscopy, atomic force microscopy, scanning electron microscopy and UV–Vis spectrophotometry. The photocatalytic activity of Bi12TiO20 thin films has been evaluated by photodegrading methyl orange solution and the effect of processing conditions on the photocatalytic activity has been studied in detail.

It is the first time that the undoped and Eu3+-doped barium stannate nanocrystals with definite morphologies are synthesized using a new combustion method. This method offers several attractive advantages such as: currency for any reagents, simple process, surprisingly short calcination time, availability of mass production and good repeatability with low cost. The characteristics of the as-synthesized nanocrystals are described with X-ray diffraction, transmission electron micrograph and luminescence spectrum.

Pure and Dy-doped ZnNb2O6 nanoparticles have been prepared by a sol−gel combustion method using citric acid as a fuel and complexing agent and nitrates as oxidants at a relatively low temperature as compared to solid-state reaction methods. X-ray diffraction patterns of the pure ZnNb2O6 samples show that the ZnNb2O6 nanoparticles exhibit an orthorhombic phase. Photoluminescence (PL) properties of all the undoped and Dy-doped samples are studied in detail. For the pure ZnNb2O6 samples, a strong blue emission band centered at 445 nm and two weak emission bands centered at 525 and 625 nm, respectively, can be observed. For Dy-doped ZnNb2O6 samples, the luminescence of Dy3+ is observed with the host blue emission remaining and the host emission intensity varying with the Dy-doping concentrations. This novel PL characteristic of the doped samples may be attributed to the energy transfer between Dy3+ and niobate groups (NbO6).