Research progress of superhydrophobic coatings based on silicone rubber surfaceXie, X W; Zhao, Y J; Shi, J B
doi: 10.1088/1742-6596/2368/1/012018pmid: N/A
Silicone rubber has excellent insulation properties such as good hydrophobic mobility and anti pollution flashover performance. It plays an important role in the power system and provides an important guarantee for the reliability of power supply. However, due to the erosion of various harsh environments, especially in wet environments such as rain and snow, a large amount of dirt and water are easily attached to the surface of insulating parts. It not only reduces its surface hydrophobicity and hydrophobic mobility, but also greatly shortens its service life. There are even serious leakage current problems. Especially in the low temperature environment, a lot of snow and flashover will occur at the accessories of the insulation parts. In order to solve this problem, super hydrophobic self-cleaning coating based on silicone rubber surface came into being. The preparation principle and model of superhydrophobic self-cleaning coating on silicone rubber surface are reviewed in this paper. By comparing different preparation methods, the advantages, disadvantages and application prospects are analyzed, and the existing problems and challenges are put forward according to the existing preparation technologies, so as to lay a theoretical foundation for preparing self-cleaning coatings with excellent performance in the future.
A thin-film waveguide problem with positive Kerr nonlinearity and its TM standing wave solutionNyamsuren, O; Ochirbat, G
doi: 10.1088/1742-6596/2368/1/012017pmid: N/A
In the previous work [1], we applied the scattering-type TM standing wave solution to a slab waveguide with negative Kerr nonlinearity. In this work, we analyzed a waveguide problem with positive Kerr nonlinearity. In our formalism, fields are expressed through the value of a dielectric function and a constant of non-flow integral of motion. We formulated the necessary boundary condition for both boundaries with no reference to a film thickness. The condition binds a dielectric function to have two equal or two different values at boundaries leading to the existence of symmetrically and asymmetrically fit wave pieces. Families of such standing wave solutions were constructed. The satisfactory boundary condition is implemented when we start to apply a film thickness to family data. The family of symmetrically fit wave pieces turned out to have a relatively complex structure due to two singularities in a dielectric function and three regions had to be analyzed separately. To look for matches within the data we presented two simple criteria that completely define the length-form and the number of standing wave solutions within a film. Afterward, a calculation of fitted solutions is straightforward.
Development of a reducer geared mechanism: performance analysis on a full-actuated adaptive finger applicationVillegas-Jiménez, Ernesto Alonso; Aranda-Herrera, Miguel Alejandro; Macedo-Chagolla, Fernando
doi: 10.1088/1742-6596/2368/1/012005pmid: N/A
The human hand is a manipulator with extraordinary capabilities, the elements that constitute it make its emulation too complex. There are manipulators with amazing and outstanding abilities that have become too complex and costly. Alternatively, there are under-actuated and self-adaptive manipulators that are simple and affordable, have appropriate performance, although their functions and gripping modes are limited and may not be entirely reliable. This paper exposes the proposal of a 12-gear reducer mechanism in 3 phases with linear array, designed to maintain a constant link transmission, amplifying the torque while the angular speed is reduced exponentially. The mechanism is attached a finger casing based on anthropomorphic aspects and is replicated twice, turning the finger into a fully actuated mechanism and with the possibility of being adaptive to different grip modes. A broad description of the system elements and their design rationale is presented. A mathematical model is developed to know the performance of the finger as a function of torque, force, angular speed and execution time of the movement, the results obtained are shown graphically accompanied by their respective concept expressions. Subsequently, the conclusions are presented. Finally, future works are described.
A squaraine-based colorimetric probe for the sensitive detection of copper ion (II)Du, Bin; Mu, Xihui; Liu, Zhiwei; Geng, Shu; Wang, Jiang; Xu, Jianjie; Chen, Lina; Tong, Zhaoyang
doi: 10.1088/1742-6596/2368/1/012038pmid: N/A
A squaraine based colorimetric probe 2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]squaraine (IHSQ) was selected for colorimetric detection of Cu2+ and the characteristics of IHSQ for Cu2+ recognition were investigated by absorption spectra. The results showed the absorbance of IHSQ significantly decreased with increasing concentration of Cu2+ in acetonitrile/H2O (V/V = 9/1). This colorimetric detection method shows a satisfactory linear response (R2 = 0.9856) to Cu2+ concentration within the range from 2 μM to 200 μM. The limit of detection was 2 μM which was much lower than the environmental protection agency guideline of China (15.63 μM) in drinking water. Moreover, no obvious interference was observed on the detection of the Cu2+ in the presence of the common metal ions such as Zn2+, K+, Ca2+, Na+, Co2+, Ba2+, Cd2+, Cr3+, Sr2+, Pb2+ and Fe3+, indicating that IHSQ possesses high selectivity and satisfactory sensitivity for the detection of Cu2+.
Study on the bonding performance between reactive powder concrete and steel barLin, Ruizong; Yu, Xinmin; Qin, Chengcheng; Ju, Yanzhong
doi: 10.1088/1742-6596/2368/1/012034pmid: N/A
The performance of reactive powder concrete (RPC) is much higher than that of ordinary concrete, and the engineering application is gradually increasing. The bond failure process and bond slip between RPC and reinforcement will show new characteristics. It is necessary to study the bond behavior between RPC and steel bar. The direct drawing test was carried out on the 36 bonding specimens in order to study the bond performance between steel bar and reactive powder concrete. The research shows that the cohesive force consists of three parts: the mechanical bite force produced by the mechanical occlusion between the reinforcing rib and the RPC; The cementing force produced by chemical reaction between RPC component and surface material of reinforcement; Friction between reinforcement and surrounding RPC. The application of ultrahigh strength and various cementitious materials make the Bonding strength between rebar and RPC significantly higher than that of normal concrete. This study can provide reference for the reinforcement anchorage design of RPC structure.
An optimum retained austenite design from bainitic matrix for a novel Q&P steelLin, Chunqing; Hu, Zhiping; Meng, Fanzhi; Liu, Rendong; Jiang, Ruiting
doi: 10.1088/1742-6596/2368/1/012023pmid: N/A
The commercial steel was processed by three different Q&P heat treatments and three kinds of steels with different microstructures and mechanical properties were obtained. Among them, two steel samples contain bainite and ferrite matrix, fresh martensite and retained austenite, while the other possesses tempered martensite and ferrite matrix, fresh martensite and retained austenite. Comparing the content of retained austenite in these samples, the highest volume fraction was obtained in the sample with bainite matrix and a higher partitioning temperature. The mechanical property result shows that the yield strength for three steel samples had little difference, but their elongations were quite different. The steel with most retained austenite exhibits a good combination of yield strength and ductility.
Characteristics of electric double-layer capacitors based on solid polymer electrolyte composed of sodium polyacrylate.Tomi, Ryu; Daisuke, Tashima; Toshihiko, Kawabata
doi: 10.1088/1742-6596/2368/1/012002pmid: N/A
Despite the low cost and high ionic conductivity of aqueous electrolytes, their practical applications are limited because a low withstand voltage of 1.2 V The energy density increases in proportion to the withstand voltage which is a crucial factor for electric double-layer capacitors (EDLCs) with solid polymer electrolytes. In this study, the electrolyte solution was made into a viscous solid polymer electrolyte to improve the withstand voltage of the electrolyte. The solid polymer electrolyte was prepared from sodium polyacrylate and doped with potassium hydroxide (KOH) and pure water. Sodium polyacrylate can absorb water at the temperature of 16-28 °C and exhibits suitable ion transfer. The EDLCs consisted of a distilled Japanese shochu-waste-activated-carbon electrode, a titanium mesh collector, and a solid polymer electrolyte. All the processes were performed at room temperature. Their electrochemical characteristics were measured using cyclic voltammetry (CV). From CV, the withstand voltage, cycle range, and specific capacitance were evaluated. The performance of the solid polymer electrolyte varied depending on the weight ratio of the constituent sodium polyacrylate and the molar concentrations of the KOH. Here, the value of molar concentration and its variation, depends on the weight ratio of the material. With the addition of sodium polyacrylate, the withstand voltage, which was 1.2 V, rose to over 2 V. Some of the samples increased up to 5 V. In the cycle measurement, the rate of decrease in capacity exceeded 20% after 250 cycles.
Experimental study on mechanical properties and porosity and permeability of rock in high temperature environmentHou, Bingchang; Sun, Feng; Xue, Shifeng; Zhang, Xudong
doi: 10.1088/1742-6596/2368/1/012031pmid: N/A
In order to explore the mechanical characteristics and porosity and permeability parameter of three kinds of rock (sandstone, granite and limestone) in high temperature environment, conventional triaxial compression experiments and porosity and permeability tests were conducted on three kinds of rocks under 25°C, 300°C and 500°C. The experimental results show that the high temperature environment increases the development degree of microcracks and pore structures in sandstone and limestone. As the temperature rises, the interpenetration length of triaxial compression shear crack of sandstone decreases gradually, and the angle between shear crack and horizontal direction increases gradually. Change of damage mode from single shear damage to tension shear damage (shear-dominated) in granite and limestone. The three rocks’ permeability and porosity increase as ambient temperature rises, and the permeability exhibits clear pressure-constricting sensitivity in a range of temperature settings. The results provide a reference for understanding and predicting the mechanical properties and porosity and permeability characteristics of rocks in high temperature environment.
Study of parameters influencing the compressive strength of Compressed Earth BlocksMango-Itulamya, Lavie Arsène; Fagel, Nathalie
doi: 10.1088/1742-6596/2368/1/012004pmid: N/A
This work aims to study four parameters that influence the compressive strength of compressed earth blocks (CEB): clay mineralogy, grain size, formatting pressure, and water content. Five soils with different mineralogical composition were used to study the first parameter. 12.5, 25, 40 and 60% of aggregates sized 0/2, 0/4 and 0/6.3 mm were added to the soil to study the second parameter. CEB were compacted at 100, 200 and 300 kN to study the third parameter. 3, 6 and 10% of water were used to study the fourth parameter. Test specimens were produced using a hydraulic press and characterized by compression. The characterization of the specimens shows that the compressive strength increases with the smectite content. Compressive strength does not always increase with changing particle size. Compressive strength increases with increasing formatting pressure, while increasing water content decreases compressive strength. This study also shows that the compressive strength of CEB is improved differently for each soil type.