Finite Element and Experimental Analysis of Ultrasonic Vibration Milling of High-Volume Fraction SiCp/Al Composites

Zhan-Li Shi,Dao-Hui Xiang,Hao-Ren Feng,Bang-Fu Wu,Zhi-Meng Zhang,Guo-Fu Gao,Bo Zhao 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.10

SiCp/Al composites have been widely used in many fields due to their excellent mechanical properties. However, the addition of reinforced phase SiC particles makes the overall properties of the composites hard and brittle, which brings great challenges to milling. Ultrasonic vibration-assisted processing technology has great advantages in processing hard and brittle materials. However, the process of rupture of SiC particles cannot be effectively observed during the test processing, and a large number of tests increase the cost of the test. The combination of finite element analysis and experiment was used to study the machining performance of High-volume fraction SiCp/Al composites in longitudinal-torsional ultrasonicassisted milling (LTUAM), and its feasibility was evaluated by comparing with conventional Milling (CM). By analyzing the trajectories of cutting edges in ultrasonic-assisted milling, It was found that ultrasonic frequency determines the time of periodic contact-separation between chisel edge and workpiece, and ultrasonic amplitude determines the maximum distance of contact-separation. Using ABAQUS finite element software, a polygon SiC particles model with a high-volume fraction was established to investigate the SiC particles crushing process under different ultrasonic-assisted milling conditions. The results showed that high-frequency ultrasonic-assisted milling could soften SiCp/Al composites, and the structural integrity of silicon carbide particles could be better maintained under appropriate ultrasonic amplitudes, reducing the probability of fragmentation. The removal mode was mainly plastic removal or crushing into small particles. The surface roughness value and milling force were reduced, improving the surface quality of the processed composite material. The conclusions of the milling test were basically consistent with the simulation results, which prove the correctness and feasibility of the simulation results

Controlled Synthesis of Hydroxyapatite Using a Novel Natural Rosin-Based Surfactant

Shu-Hui Zhan,Xue-He Jiang,Juan Li,Zhi Meng,Lin-Lin Chen,Chun-Rui Han 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.8

Hydroxyapatite (HAP) with multiform morphologies, such as hollow dandelion-like bundles and nanoparticles with a diameter of 50 nm, was prepared using natural rosin-based surfactant dehydroabietyl phosphate diester (DDPD) as phosphorus source, crystal growth control agent, and template simultaneously by a facile hydrothermal method. Samples were obtained and characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Results showed that DDPD and pH value of solution were the key factors for the morphology of HAP. Hollow dandelion-like bundles HAP, containing the Ca-monodehydroabietyl phosphate (PM-Ca) organic metal compounds, were formed at pH=3 without acid-base regulation, and nanoparticles were obtained at pH=12. SEM exhibited that the hollow dandelion-like bundles HAP are of 10 μm (outer) and 1 μm (inner) diameter, respectively. Cell viabilities are above 95% when the cells are co-cultured with all HAP samples at concentrations in the range of 250–1000 μg/ml. It indicated that the prepared HAP with PM-Ca has a good cytocompatibility without apparent toxicity. Finally, the possible formation mechanism of the HAP microstructures was discussed in detail.

Effect of Ultrasonic Vibration Tensile on the Mechanical Properties of High-Volume Fraction SiCp/Al Composite

Dao-Hui Xiang,Zhi-Meng Zhang,Bang-Fu Wu,Hao-Ren Feng,Zhan-Li Shi,Bo Zhao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.11

Silicon carbide particle-reinforced aluminum matrix composite has been widely used in the military and aerospace industry due to its special performance; however, there remain many problems in processing. The present paper introduces an ultrasonic vibration tensile device with a view to investigating an ultrasonic vibration tensile specimen. The results show that there are three major stages in the change in stress of the material under ultrasonic vibration: the ultrasonic stress superposition effect, softening effect, and Hall–Petch strengthening effect, these three effects occupy different proportions in different tensile stages. In addition, increasing the frequency of ultrasonic vibration increased the degree of stress reduction. Increasing the ultrasonic vibration amplitude reduced the fracture strength of the material. Comparison of the fracture morphology shows that the conventional condition was mainly interfacial peeling of SiC particles, and cleavage of the fracture occurred under ultrasonic vibration conditions.

Gingerol Inhibits Cisplatin-induced Vomiting by Down Regulating 5-Hydroxytryptamine, Dopamine and Substance P Expression in Minks

Qiu-hai Qian,Wen-hui Chen,Wang Yue,Yao-xia Wang,Zhi-hong Yang,Zhan-tao Liu 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.4

Objective: To investigate the antiemetic effect of gingerol and its multi-targets effective mechanism on 5-hydroxytryptamine (5-HT), dopamine (DA) and substance P (SP). The antiemetic effect of gingerol was investigated on a vomiting model of mink induced by cisplatin (7.5 mg· kg−1, i.p.) in 6 h observation. The levels of 5-HT, DA and distribution of substance P in the area postrema and ileum were measured by high performance liquid chromatography (HPLC) and immunohistochemistry respectively. The frequency of cisplatin induced retching and vomiting was significantly reduced by pretreatment with gingerol in a dose-dependent manner (P<0.05). Cisplatin produced a significant increase in 5-HT and DA levels in the area postrema and ileum of minks (P<0.05), and this increase was significantly inhibited by gingerol in a dose-dependent manner (P<0.05). Substance P-immunoreactive was mainly situated in the mucosa and submucosa of ileum as well as in the neurons of area postrema, and gingerol markedly suppressed the increase immunoreactivity of substance P induced by cisplatin in a dose-dependent manner (P<0.05). Gingerol has good activity against cisplatin-induced emesis in minks possibly by inhibiting central or peripheral increase of 5-HT, DA and substance P.

Hyperparameters optimization of convolutional neural network based on local autonomous competition harmony search algorithm

Liu Dongmei,Ouyang Haibin,Li Steven,장춘량,Zhan Zhi-Hui 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.4

Because of the good performance of convolutional neural network (CNN), it has been extensively used in many fields, such as image, speech, text, etc. However, it is easily affected by hyperparameters. How to effectively configure hyperparameters at a reasonable time to improve the performance of CNNs has always been a complex problem. To solve this problem, this paper proposes a method to automatically optimize CNN hyperparameters based on the local autonomous competitive harmony search (LACHS) algorithm. To avoid the influence of complicated parameter adjustment of LACHS algorithm on its performance, a parameter dynamic adjustment strategy is adopted, which makes the pitch adjustment probability PAR and step factor BW dynamically adjust according to the actual situation. To strengthen the fine search of neighborhood space and reduce the possibility of falling into local optima for a long time, an autonomous decision-making search strategy based on the optimal state is designed. To help the algorithm jump out of the local fitting situation, this paper proposes a local competition mechanism to make the new sound competes with the worst harmonic progression of local selection. In addition, an evaluation function is proposed, which integrates the training times and recognition accuracy. To achieve the purpose of saving the calculation cost without affecting the search result, it makes the training time for each model depending on the learning rate and batch size. In order to prove the feasibility of LACHS algorithm in configuring CNN superparameters, the classification of the Fashion-MNIST dataset and CIFAR10 dataset is tested. The comparison is made between CNN based on empirical configuration and CNN based on classical algorithms to optimize hyperparameters automatically. The results show that the performance of CNN based on the LACHS algorithm has been improved effectively, so this algorithm has certain advantages in hyperparametric optimization. In addition, this paper applies the LACHS algorithm to expression recognition. Experiments show that the performance of CNN optimized based on the LACHS algorithm is better than that of the same type of artificially designed CNN. Therefore, the method proposed in this paper is feasible in practical application.

Shortest Path Analyses in the Protein-Protein Interaction Network of NGAL (Neutrophil Gelatinase-associated Lipocalin) Overexpression in Esophageal Squamous Cell Carcinoma

Du, Ze-Peng,Wu, Bing-Li,Wang, Shao-Hong,Shen, Jin-Hui,Lin, Xuan-Hao,Zheng, Chun-Peng,Wu, Zhi-Yong,Qiu, Xiao-Yang,Zhan, Xiao-Fen,Xu, Li-Yan,Li, En-Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

NGAL (neutrophil gelatinase-associated lipocalin) is a novel cancer-related protein involves multiple functions in many cancers and other diseases. We previously overexpressed NGAL to analyze its role in esophageal squamous cell carcinoma (ESCC). In this study, a protein-protein interaction (PPI) was constructed and the shortest paths from NGAL to transcription factors in the network were analyzed. We found 28 shortest paths from NGAL to RELA, most of them obeying the principle of extracellular to cytoplasm, then nucleus. These shortest paths were also prioritized according to their normalized intensity from the microarray by the order of interaction cascades. A systems approach was developed in this study by linking differentially expressed genes with publicly available PPI data, Gene Ontology and subcellular localizaton for the integrated analyses. These shortest paths from NGAL to DEG transcription factors or other transcription factors in the PPI network provide important clues for future experimental identification of new pathways.