Abstract: In order to study the dynamic characteristics of red sandstone under cyclic impact, the cyclic impact test of red sandstone at the same incident velocity was carried out by E-SHPB test device. Through the analysis and summary of the test data, the influence of cyclic loading times on the dynamic compressive strength of red sandstone and the failure process of red sandstone under the impact of 1000v loading voltage are discussed. The test results show that under the impact of 1000v loading voltage, the peak stress of the specimen decreases linearly with the increase of the number of impacts. The dynamic compressive strength of the specimen under the fifth cyclic impact loading is about 9MPa lower than that under the first impact, and the resistance to deformation is weakened. With the increase of the number of impacts, the cracks in the specimen are continuously generated and expanded, and the specimen is mainly split failure. Read More

Abstract: During the process of inverse kinematics solving for a robotic arm, heuristic optimization algorithms have been widely applied. However, due to the complex structure of the robotic arm, these algorithms suffer from drawbacks such as slow convergence speed and a tendency to get trapped in local optima. Therefore, a novel metaheuristic optimization algorithm called the Chimpan-zee Optimization Algorithm (ChOA) has been introduced, along with multiple strategy improvements to enhance its global search capability and convergence optimization performance. Through simulation experiments on the modified Chim-panzee Optimization Algorithm (MChOA), it has been demonstrated that this method outperforms the traditional ChOA algo-rithm in terms of convergence speed and accuracy, effectively addressing the issues of slow convergence and being trapped in local op-tima. Read More

Abstract: Cementitious Capillary Crystalline Waterproofing materials (hereinafter: CCCW) with the advantages of good waterproof effect, green and low cost, it is widely used in the field of building waterproofing. Researchers and scholars have studied the proportioning of such materials. However, the experimental methods used in these studies are not perfect enough, therefore, this study uses a seven-factor, two-level orthogonal test method to conduct experiments and to study the waterproofing effect of CCCW coated on the substrate at different ages, and to discuss the existing waterproofing mechanism in conjunction with it. The results show that the group's homemade waterproofing agent has a good waterproofing effect, and the compressive strength is significantly increased at different ages, which suggests that CCCW can promote the hydration of cement and produce more penetrating crystals, thus blocking the capillary pores and microcracks, and making the matrix dense and waterproof. Read More

Abstract: With the continuous progress of science and technology, service robots have gradually penetrated into various industries, including catering, travel, home and medical fields. The rapid development of this technology has attracted wide attention in today's society, involving artificial intelligence, machine learning, and human-computer interaction, and has brought major changes to our lives and work. However, the adoption of new technologies is not always smooth, and the level of acceptance varies. This paper takes the technology acceptance model (TAM) and its derivative model as the theoretical framework to deeply explore the factors that affect the acceptance of service robots. Various factors revealed by TAM technology acceptance model and its derivative model will be discussed in depth respectively. This study will help to reveal all possible factors that affect user acceptance of service robots, such as functional elements, emotional elements and users' own characteristics, for future research. Read More

Abstract: Fire water cannon is the main equipment in fire protection work, which is evolving towards large flow, long distance and high shooting. As an important core component of fire water monitor, the structural design of nozzle plays an important role in jet performance. The Fluent fluid simulation software was used to simulate the internal flow field of the fire nozzle model with different outlet diameters and convergence angles. The average jet velocity and turbulent kinetic energy under different parameters were compared to obtain the optimal size parameters of the fire nozzle. The results show that when the inlet diameter is 100 mm, the inlet pressure is 1.2 MPa, the length of the rectifier section is 95 mm, the outlet diameter is 50 mm, and the convergence angle is 11 °, the jet performance of the fire monitor nozzle is the best. The simulation results can provide reference for the structural design and practical application of fire water monitor nozzle. Read More

Abstract: As a new type of green and environmentally friendly aluminosilicate gel material, geopolymer has attracted much attention from scholars for its good ability to immobilize heavy metals compared with traditional cement-based curing agents. Based on the research progress of geopolymer solidification of heavy metal contaminated soil at home and abroad in recent years, this paper introduces the process of geological polymerization reaction. The solidification mechanism of geopolymer on heavy metal contaminated soil and the influence of different factors on the solidification effect of geopolymer on heavy metal contaminated soil are described in detail. The leaching characteristics of heavy metals in geopolymer solidified heavy metal contaminated soil under freeze-thaw cycle, dry-wet cycle and carbonization were further discussed. Finally, the problems existing in the solidification of heavy metal contaminated soil by geopolymer are analyzed and the future research and development direction is prospected. Read More

Abstract: Drilling fluid is known as the blood of drilling engineering, which plays an important role in drilling engineering. The real-time measurement of drilling fluid rheological parameters is crucial to the optimization and adjustment of drilling scheme. Pipe flow method is a common method of measuring drilling fluid rheology parameters, pipe flow method monitoring equipment is an important reason of the pipe flow method monitoring principle, the analysis of the reason, put forward the spiral development section optimization scheme, using F LUENT numerical simulation software for simulation, the optimization platform and verify the reliability of the optimization of numerical simulation results, greatly reduce the pipe flow, method monitoring equipment volume. It also provides a theoretical basis for other pipeline measurement fields. Read More

Abstract: In this study, the operational parameters of the micro-cyclone were investigated. A 10 mm micro-cyclone suitable for waste drilling mud treatment was designed and the effect of the inlet on the flow field within the micro-cyclone as well as the total separation efficiency was investigated using CFD techniques. It was concluded that the pressure gradient inside the micro-cyclone increased with increasing inlet flow; axial and tangential velocities increased with increasing inlet flow; the peak turbulent kinetic energy increased with increasing inlet flow; and the total separation efficiency increased and then decreased slightly with increasing inlet flow. Read More

Abstract: At request of the authors, this article has been retracted by Warwick Evans Publishing (WEP) in light of clear evidence that the results and conclusions are no longer valid. We thank the authors for notifying us so that the publication record can be amended accordingly. Retraction published: May 9, 2024. Read More

Abstract: Based on the Euler-Euler two-fluid model, the circulating fluidized bed was simulated using the computational fluid dynamics (CFD) method. The physical model of the circulating turbulent fluidized bed had an inner diameter of 76mm and a height of 2000mm. The circulating material consisted of class B particles, with an initial bed material mass (Mp) of 0.188kg. Air was uniformly introduced at a velocity of 0.3m/s at the bottom of the riser, and secondary air was introduced at a velocity of 0.9m/s at the secondary air inlet. Numerical simulations were conducted to study the gas-solid flow characteristics of the entire circuit. The turbulent bed, fast bed particle concentration, material circulation rate, and pressure drop gradient were analyzed to evaluate the performance of the entire circuit. The results showed that the particle concentration at the bottom of the riser was higher in the overall circuit flow, and a turbulent state could be achieved at low gas velocities. The particle concentration in the transport bed was low, indicating good gas-solid interaction. Strong backmixing occurred at the connection between the return valve and the turbulent bed. Additionally, there was intense gas-solid reaction at the secondary air inlet. Read More

Abstract: ZigBee technology is a low-power, low-cost, short-range wireless communication technology for various IoT (Internet of Things) applications. Machinery parts detection system monitors the quality, size, shape, and other parameters of machinery parts in real time to ensure the accuracy and quality of the production process. In this article, we propose a machinery parts detection scheme based on ZigBee technology. By deploying wireless sensor networks, the detection data concerning machinery parts could be transmitted in real time, thus reducing the complexity of wiring and improving detection efficiency. ZigBee based machinery parts detection system would provide an efficient and convenient means of detection for the manufacturing industry, thus enjoying a wide range of application prospects. Read More

Abstract: Numerous scholars' studies usually adopt the Wiener process to establish industrial robot performance degradation models and randomize the drift coefficients to characterize the differences in individual degradation rates, but they do not take into account the influence of measurement errors on the accuracy of the models. Aiming at the above problems, combining the Wiener process and the accelerated degradation model, the accelerated degradation reliability model of industrial robots based on the multi-uncertainty Wiener process is established, and by adding the factor of measurement error, the model is able to more accurately characterize the influence of external factors on the degradation process of industrial robots. Bayesian theory, Markov chain Monte Carlo method and Bootstrap method are used to estimate the unknown parameters in the model. Finally, the accuracy of the proposed parameter estimation method and model is verified by simulating the industrial robot performance degradation data with Monte Carlo method. Read More