Article
Engineering, Environmental
Jiqin Wang, Xiaoxia Yi, Xiangfei Zeng, Shuyuan Chen, Rui Wang, Jiancheng Shu, Mengjun Chen, Zhengxue Xiao
Summary: Superfine copper particles can be directly prepared from waste printed circuit boards by slurry electrolysis, with observed copper fractal growth. Factors affecting copper dendrites were discussed in detail, showing that gelatin concentration significantly impacts fractal degree. The diffusion-limited aggregation model demonstrated that particle speed, number, and binding probability significantly affect copper dendrite patterns.
FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Jiqin Wang, Xiangfei Zeng, Hailong Li, Junwei Han, Xinzhang Shi, Yifan Wei, Songshan Zhou, Rong Huang, Qian Liang, Jiancheng Shu, Mengjun Chen, Zhengxue Xiao
Summary: This study discusses in detail the factors that impact two-dimensional gold dendritic patterns, finding that increasing the applied voltage and the concentrations of chloroauric acid and hydrochloric acid can increase the probability of particle movement, leading to an increase in the fractal dimension. Additives PVP and trisodium citrate can inhibit fractal growth and improve the recovery rate and current efficiency of gold.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Engineering, Chemical
Long Che, Xiaohui Gu, Hongda Li
Summary: The study investigates the influence factors of hard rock fragmentation through numerical simulation and experimental research of high voltage pulse discharge, finding that the fragmentation effect is strongly dependent on the electrode gap and rock type. The experimental results are consistent with the simulations, providing appropriate conditions for the subsequent application of high voltage pulse discharge in hard rock fragmentation.
MINERALS ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Jianyu Peng, Hongpeng Xu, Fengpeng Zhang, Haonan Wang, Jiaqiang Li
Summary: This research investigates the fracturing behaviors of sandstone under pulsed high-voltage discharge (PHVD) and different static pressures. The effects of static pressure on crack length and fractal dimension were analyzed, indicating that static pressure alters the distribution and propagation of cracks. When static pressure is vertical to the discharge channel, it changes the distribution zone and propagation path of cracks, while parallel static pressure increases the fractal dimension and length of cracks.
Article
Engineering, Chemical
Yonghong Qin, Yuexin Han, Peng Gao, Yanjun Li, Shuai Yuan
Summary: This study systematically discusses the effects of high voltage pulse discharge on chalcopyrite ore. It was found that increasing the voltage and pulse numbers led to an increase in undersize content and reduction ratio, as well as an increase in the dispersion degree of particle size distribution and a decrease in uniformity. The specific energy consumption of high voltage pulse discharge breakage was described by the Walker theory. Additionally, the high voltage pulse discharge could significantly reduce the mechanical strength of the ore and improve its grinding efficiency.
MINERALS ENGINEERING
(2022)
Article
Automation & Control Systems
Shanshan Jin, Jindong Chen, Zhibin Li, Chunhui Zhang, Yajun Zhao, Zhi Fang
Summary: This article introduces a high-voltage pulse current power supply (HV-PCPS) based on RDD shaping method, which can solve the problem of poor waveform quality, ensure stable discharge, and limit the maximum output voltage amplitude. The effectiveness of the proposed method is verified through a 30kV HV-PCPS prototype.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Energy & Fuels
Jianyu Peng, Chuan Du, Fengpeng Zhang, Jikai Gao, Haonan Wang
Summary: The high-voltage pulse technique is a promising method for rock fragmentation in rock engineering. This study established a circuit system to investigate the fracturing effect of high-voltage pulses on granite. The results showed the formation of breakdown, radial crack, and circumferential crack zones within the granite specimens. The median size of fragments gradually increased with the growth of specimen size, while it decreased with increasing charge voltage and attenuated exponentially with energy density. High-temperature melting and shock waves were identified as the dominant factors inducing rock fracturing.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Computer Science, Information Systems
Khoa Dang Pham, Mon-Van Doi, Nho-Van Nguyen
Summary: This article proposes a hybrid pulse-width modulation scheme to reduce high-frequency Common-mode voltage and improve power loss, Electromagnetic Interferences, and harmonic distortion in the three-level Neutral-Point-Clamped converter. The scheme features reduced Common-mode-voltage magnitudes and variations, zero average Common-mode-voltage, and improved harmonic distortion. The results show decreased RMS leakage current and similar-to-better harmonic distortion in the converter at the expense of slight reduction of the efficiency.
Article
Biodiversity Conservation
L. D. Vorsatz, P. Pattrick, F. Porri
Summary: The complexity of mangrove root systems has a significant impact on the occurrence of larval communities in marine ecosystems, with different tree species showing significant differences in root system complexity. Measuring these indices can help understand how boundary layer dynamics change with tides and impact ecosystem services.
ECOLOGICAL INDICATORS
(2021)
Article
Engineering, Geological
Xiaohua Zhu, Yunxu Luo, Weiji Liu, Ling He, Rui Gao, Yudan Jia
Summary: The paper delves into the mechanism of partial electrical breakdown in high-voltage pulsed fragmentation (HVPF) technology and provides a method for designing and optimizing parameters, establishing a theoretical basis for the application of multi-pulse electrical breakdown technology. This research contributes to improving the efficiency and development potential of rock-breaking technology.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Hao Tian, Li Ding, Yun Wei Li
Summary: This paper introduces a seven-level hybrid clamped topology and enhances its performance by enabling a nine-level operation. The method does not require modifications to the topology and only minor modifications to the modulation are needed to expand the speed range of the motor drive system. Experimental results demonstrate the feasibility and performance of this method.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Multidisciplinary Sciences
Hanna Poikonen, Tomasz Zaluska, Xiaying Wang, Michele Magno, Manu Kapur
Summary: The current trend in neuroscience is to study brain functions during ecologically valid conditions using naturalistic stimuli. This study uses a non-linear method to classify the brain activities of math experts and novices during complex math demonstrations. The results suggest that data-driven intelligent approaches, such as machine learning, can help us develop and test new theories on complex brain functions.
SCIENTIFIC REPORTS
(2023)
Article
Energy & Fuels
Jian Zheng, Cunxing Peng, Kaihui Zhao, Mingcheng Lyu
Summary: This study proposes a low common-mode SVPWM method to reduce the common-mode voltage generated in two-level three-phase voltage source inverters. Simulation and experimental results demonstrate that the proposed method can effectively reduce the CMV peak-to-valley value and jump frequency, while improving the performance of line voltage and line current.
Article
Mathematics, Interdisciplinary Applications
Huibo Song, Shasha Nie, Yi Jin, Xiangyu Zhang, Hongliang An
Summary: The study established fractal topography in Zoophycos and proposed a fractal dimension (D) model, analyzing the correlation of D with paleo-water depth and substrate consistency. The results showed that D increases with paleo-water depth, but decreases when substrate consistency increases.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2021)
Article
Engineering, Electrical & Electronic
Zhiyuan Zhang, Hengxin He, Hui Yu, Kejie Li, Kai Bian, Weijiang Chen
Summary: In order to simulate the electric field during a lightning strike, a voltage pulse generator is urgently needed. This study proposes a new pulse generator structure based on a push-pull dc-dc converter and a flyback converter. The pulses produced by the generator have a variable voltage rise rate, and a modular design is used. Each module works independently and is powered by an exclusive lithium battery, avoiding the problems of existing generators. The electrical behavior of the generator during the switching transient is analyzed, and the accuracy and feasibility of the proposed generator are verified through experiments.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.