Saw-Tooth Chip Formation and Its Effect on Cutting Force Fluctuation in Turning of Inconel 718

Song Zhan,Jianfeng Li,Xiaoli Zhu,Honggang Lv 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Chip formation and its morphology are important features of metal cutting, and they can yield much more important information on the cutting operations. Meantime, the cutting forces are the most commonly used on-line indicators to monitor the cutting process. In this research, the formation of the saw-tooth chips has been investigated in association with the fluctuation of the cutting force components under different cutting parameters in turning of Inconel 718 with (Ti, Al)N/TiN coated cutting tools under dry cutting condition. By means of the optical microscopy and the scanning electron microscopy (SEM), the saw-tooth chips are observed at high cutting speeds, which directly cause the cutting force components to fluctuate. Based on the frequency analysis, the segmentation frequencies of the saw-tooth chips and the fluctuation frequency of the cutting forces are very close to each other. It indicates that the formation of the saw-tooth chips is one of the important factors leading to the periodical fluctuation of the cutting force components, even though the cutting parameters all keep constant in turning of Inconel 718.

Determination of equivalent blasting load considering millisecond delay effect

Song, Zhan-Ping,Li, Shi-Hao,Wang, Jun-Bao,Sun, Zhi-Yuan,Liu, Jing,Chang, Yu-Zhen Techno-Press 2018 Geomechanics & engineering Vol.15 No.2

In the analysis of the effects of rock tunnel blasting vibration on adjacent existing buildings, the model of simplified equivalent load produces higher calculation result of vibration, due to the lack of consideration of the millisecond delay effect. This paper, based on the static force equivalence principle of blasting load, proposes a new determination method of equivalent load of blasting vibration. The proposed method, based on the elastic-static force equivalence principle of stress wave, equals the blasting loads of several single blastholes in the same section of millisecond blasting to the triangle blasting load curve of the exploded equivalent elastic boundary surface. According to the attenuation law of stress wave, the attenuated equivalent triangle blasting load curve of the equivalent elastic boundary is applied on the tunnel excavation contour surface, obtaining the final applied equivalent load. Taking the millisecond delay time of different sections into account, the time-history curve of equivalent load of the whole section applied on the tunnel excavation contour surface can be obtained. Based on Sailing Tunnel with small spacing on Sanmenxia-Xichuan Expressway, an analysis on the blasting vibration response of the later and early stages of the tunnel construction is carried out through numerical simulation using the proposed equivalent load model considering millisecond delay effect and the simplified equivalent triangle load curve model respectively. The analysis of the numerical results comparing with the field monitoring ones shows that the calculation results obtained from the proposed equivalent load model are closer to the measured ones and more feasible.

Active Damping Stability Control Method Based on Voltage Compensation for IPMSM Drives with Small DC-Link Capacitor

Song Jian,Song Wen-Xiang,Liu Zhan-Jun,Ma Shao-Cai 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

Aiming at the unstable phenomena such as high DC-link voltage ripple that occur in the interior permanent magnet synchronous motor drive system of the small DC-link capacitor when the rotor speed is high or the load power is large, this paper proposes an active damping control method based on voltage compensation. The method starts from the mathematical model of the driving system, based on the characteristic equation of the driving system, and according to the Rouse stability criterion, the driving system is stabilized by applying a virtual resistance to change the coefficient of the characteristic equation. The proposed method only needs a bandpass filter to extract the DC-link voltage ripple, which is then compensated to the motor stator voltage axis by the damping coefficient. In order to obtain high damping performance, considering the time constant and the delay of the control loop, the theoretical design basis for a reasonable value of the damping coefficient is given, and the influence of the proposed method on the performance of the drive system is evaluated. Simulation and experimental results verify the effectiveness of the proposed method.

A Clustering Sleep Scheduling Mechanism Based on Sentinel Nodes Monitor for WSN

Zhan-Yang Xu,Song-Gang Zhao,Zheng-Jun Jing 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.1

This paper proposes a clustering sleep scheduling mechanism based on sentinel nodes monitoring for WSN. The mechanism combines the network clustering strategy with the node dormancy strategy, and improves the method of selecting the candidate cluster heads randomly in Energy-Efficient Unequal Clustering (EEUC) algorithm. The conception of sentinel node is introduced based on EEUC, and the neighbor node set of sentinel node will be dormant when the sentinel node’s data change rate is lower than the setting threshold. Simulation results show that this mechanism can effectively balance the energy consumption of the entire network, and significantly extend the network lifetime.

Integrated Protection Unit Design for Power Networks

Zhan-feng Fan,Sheng-ming Ge,Z Q Bo,Lin Wang,Feng-quan Zhou,Xing Liu,Guo-bing Song 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

This paper presents an hardware design solution for integrated protection of distribution systems (Network Protection Unit) by combining transient polarity comparison technique, which is based on the detection and processing of fault generated transient current signals. The integrated protection relays installed at each substation of a distribution network are communicated with the Network Protection Unit through specially designed Packet Transport Network (PTN) for fast and reliable transmission of transient polarity current signals. The relay detects the faulted generated super-imposed current signals. The transient polarity identification algorithm is then applied to the super-imposed signals to identify the polarity of the signal detected. The Network Protection Unit can collect all the transient polarity current signals under its protection area. Then The direction of a fault is determined by comparison of the polarity of the signals derived from all the line sections connected to the substation. The actual faulted section is identified by the Network Protection Unit through comparing the directional information from various stations. Simulation results presented in the paper demonstrate the feasibility of the scheme.

Functional Roles of Exosomes in Allergic Contact Dermatitis

Song Bocui,Chen Qian,Li Yuqi,Zhan Shuang,Zhao Rui,Shen Xue,Liu Min,Tong Chunyu 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.12

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.

Apoptin Induces Apoptosis in Human Bladder Cancer EJ and BIU-87 Cells

Zhan, Hui,Wang, Jian-Song,Wang, Hai-Feng,Zuo, Yi-Gang,Wang, Chun-Hui,Ding, Ming-Xia Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Objective: To investigate whether apoptin is a apoptosis-inducing protein with a potential for bladder cancer therapy. Methods: We constructed a PCDNA3/Apoptin eukaryotic expression vector, and transfected this vector into bladder cancer cell lines BIU-87 and EJ, then observed the results by RT-PCR, transmission electron microscopy, MTT assay and the flow cytometry (TUNEL method). Results: PCDNA3/Apoptin successfully induced a high level apoptosis in both bladder cancer cell lines, compared with the controls (p<0.05). Conclusions: Apoptin can induce high level apoptosis in human bladder cancer EJ and BIU-87 cells, which suggests a potential for human bladder cancer therapy.

Significant Differences in the Clinicopathological Characteristics and Survival of Gastric Cancer Patients from Two Cancer Centers in China and Korea

Shen, Zhan Long,Song, Kyo Young,Ye, Ying Jiang,Xie, Qi Wei,Liang, Bin,Jiang, Kewei,Park, Cho Hyun,Wang, Shan The Korean Gastric Cancer Association 2015 Journal of gastric cancer Vol.15 No.1

Purpose: To compare the clinicopathological data and long-term survival of gastric cancer patients in China and Korea. Materials and Methods: Patients who had undergone gastrectomy for gastric cancer between 1998 and 2009 in 2 high-volume institutions in both China (n=1,637) and Korea (n=2,231) were retrospectively evaluated. Clinicopathological variables, overall survival (OS), progression-free survival (PFS), and surgery-related complications were assessed for all patients and compared between the 2 institutions. Results: Chinese patients included in the study were significantly older and had a significantly lower body mass index (BMI) than the Korean patients. Esophagogastric junction tumors were more frequent in Chinese patients. However, the number of patients with stage I gastric cancer, the number of harvested lymph nodes, and the number of total gastrectomies were significantly higher in the Korean population. Korean patients also presented with fewer undifferentiated tumors than Chinese patients. Furthermore, Korean patients had prolonged OS and PFS for stage III cancers only. BMI, tumor-node-metastasis (TNM) stage, tumor invasion, number of positive lymph nodes, and distant metastases were all independent factors affecting OS and PFS. Conclusions: Although China and Korea are neighboring Asian countries, the clinicopathological characteristics of Chinese patients are significantly different from those of Korean patients. Korean gastric cancer patients had longer OS and PFS than Chinese patients. Influencing factors included TNM stage, tumor invasion, and lymph node metastasis.

Comparison of long-term behavior between prestressed concrete and corrugated steel web bridges

Yulin Zhan,Fang Liu,Zhongguo John Ma,Zhiqiang Zhang,Zengqiang Duan,Ruinian Song 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.6

Prestressed concrete (PC) bridges using corrugated steel webbing have emerged as one of the most promising forms of steel-concrete composite bridge. However, their long-term behavior is not well understood, especially in the case of largespan bridges. In order to study the time-dependent performance, a large three-span PC bridge with corrugated steel webbing was compared to a similar conventional PC bridge to examine their respective time-dependent characteristics. In addition, a threedimensional finite element method with step-by-step time integration that takes into account cantilever construction procedures was used to predict long-term behaviors such as deflection, stress distribution and prestressing loss. These predictions were based upon four well-established empirical creep prediction models. PC bridges with a corrugated steel web were observed to have a better long-term performance relative to conventional PC bridges. In particular, it is noted that the pre-cambering for PC bridges with a corrugated steel web could be smaller than that of conventional PC bridges. The ratio of side-to-mid span has great influence on the long-term deformation of PC bridges with a corrugated steel web, and it is suggested that the design value should be between 0.4 and 0.6. However, the different creep prediction models still showed a weak homogeneity, thus, the further experimental research and the development of health monitoring systems are required to further progress our understanding of the long-term behavior of PC bridges with corrugated steel webbing.

An Approach for Reducing Cutting Energy Consumption with Ultra-High Speed Machining of Super Alloy Inconel 718

Bing Wang,Zhan-qiang Liu,Qinghua Song,Yi Wang,iaoping Ren 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

High energy efficient machining is beneficial for sustainable manufacture which is an important target pursued by workshops. The paper aims to prove the feasibility for reducing cutting energy consumption with ultra-high speed machining (UHSM) of super alloy Inconel 718. Firstly, orthogonal cutting experiments of Inconel 718 are performed with a wide cutting speed range. Through analyses of chip micrographs, it is found that plastic deformation accompanied with ductile fracture contributes to serrated chip formation, while fragmented chips are produced through brittle fracture. The results demonstrate that brittle regime machining can be realized for Inconel 718 with ultra-high cutting speeds. Secondly, considering varied deformation behavior for chips with different morphologies, specific cutting energy models for HSM under varied cutting parameters are developed and verified. Then the influences of cutting speed and uncut chip thickness on cutting energy consumption during HSM are revealed. The research results demonstrate the practicability for reducing cutting energy consumption with brittle regime machining of Inconel 718. At last, the relationship between AE signals and cutting energy consumption is explored, and it proves that AE signals are applicable in monitoring cutting energy consumption. The research can provide guidance for energy saving through optimizing cutting parameters.