A Study on the Design of a Gear Transmission Error Test Rig

Qi Zhang(장기),Jing Zhang(장정),Hou-Ling Yan(연후링),Qing-Wang Zhu(주징왕),Zhe-zhu Xu(허철수),Sung-Ki Lyu(류성기) 한국기계가공학회 2016 한국기계가공학회지 Vol.15 No.1

Transmission error (TE) is the most important cause of gear noise and vibration because TEs affect the changes of the force and the speed of gears. TE is usually expressed as an angular deviation, or a linear deviation measured at the pitch point and calculated at successive positions of the pinion as it goes through the meshing cycle. Accurate measurement of TE for gear transmission will provide a reasonable basis for gear design, manufacturing processes and quality control. Therefore, in order to study the accuracy of the gear transmission, stability, TE, vibration and noise after gear micro-geometry modification, a gear transmission test rig is proposed in this paper, which is based on the existing technical conditions, by using reasonable testing methods, hardware and a signal processing method. All of the details and the experience can be taken into consideration in the next upgraded test rig.

Risk Factors for Cervical Cancer in Rural Areas of Wuhan China: a Matched Case-control Study

Zhang, Bin,Zhou, Ai-Fen,Zhu, Chang-Cai,Zhang, Ling,Xiang, Bing,Chen, Zhong,Hu, Rong-Hua,Zhang, Ya-Qi,Qiu, Lin,Zhang, Yi-Ming,Xiong, Chao-Du,Du, Yu-Kai,Shi, Yu-Qin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

Effect of compressible membrane’s nonlinear stress-strain behavior on spiral case structure

Qi-Ling Zhang,He-Gao Wu 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.1

With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material’s nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material’s hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

Effect of compressible membrane's nonlinear stress-strain behavior on spiral case structure

Zhang, Qi-Ling,Wu, He-Gao Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.1

With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material's nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material's hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

Asparagus Polysaccharide and Gum with Hepatic Artery Embolization Induces Tumor Growth and Inhibits Angiogenesis in an Orthotopic Hepatocellular Carcinoma Model

Weng, Ling-Ling,Xiang, Jian-Feng,Lin, Jin-Bo,Yi, Shang-Hui,Yang, Li-Tao,Li, Yi-Sheng,Zeng, Hao-Tao,Lin, Sheng-Ming,Xin, Dong-Wei,Zhao, Hai-Liang,Qiu, Shu-Qi,Chen, Tao,Zhang, Min-Guang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.24

Liver cancer is one of leading digestive malignancies with high morbidity and mortality. There is an urgent need for the development of novel therapies for this deadly disease. It has been proven that asparagus polysaccharide, one of the most active derivates from the traditional medicine asparagus, possesses notable antitumor properties. However, little is known about the efficacy of asparagus polysaccharide as an adjuvant for liver cancer chemotherapy. Herein, we reported that asparagus polysaccharide and its embolic agent form, asparagus gum, significantly inhibited liver tumor growth with transcatheter arterial chemoembolization (TACE) therapy in an orthotopic hepatocellular carcinoma (HCC) tumor model, while significantly inhibiting angiogenesis and promoting tumor cell apoptosis. Moreover, asparagine gelatinous possessed immunomodulatory functions and showed little toxicity to the host. These results highlight the chemotherapeutic potential of asparagus polysaccharide and warrant a future focus on development as novel chemotherapeutic agent for liver cancer TACE therapy.

Commutation Torque Ripple Suppression in Three Phase Brushless DC Motor Using Open-end Winding

Qi Huang,Ling Luo,Yuan Zhang,Jichao Cao 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8

Three phase brushless DC motor has the characteristics of high power density, simple structure and excellent speed regulation performance, which is widely used in the field of electric drive. Open-end winding brushless DC motor has no neutral point, and each phase winding is electrically isolated, which can realize the independent control of each phase winding. Compared with Y-connected brushless DC motor, the open-end winding brushless DC motor has a wider range of speed regulation under the same voltage, and has certain fault-tolerant performance, which is suitable for the application of low voltage and large current. Compared with the multiphase fault-tolerant motor, open-end winding brushless DC motor has simpler structure and higher winding utilization rate. However, the open-end winding brushless DC motor still has torque ripple, among which the cogging torque is related to the motor body structure, while commutation torque ripple is affected by the mutual inductance ofthe winding and the current freewheeling loop. The commutation process of the open-winding brushless DC motor is analyzed, and it is concluded that the current change rates of the turn-off phase and turn-on phase are equal under the ideal back electromotive force(back-EMF), which can ensure that the non-commutation phase current and the electromagnetic torque kept constant. The overlapping commutation with phase current closed-loop method is proposed to suppress the commutation torque ripple of open-end winding BLDC motor, and the applied voltage on turn-off phase and delayed time of turn-off phase in overlapping commutation are derived, the sliding mode observer is used to calculate the electromagnetic torque. MATLAB simulation and experimental results verify the effectiveness of this method.

Comparative Proteomic Analysis of Changes in the Bovine Whey Proteome during the Transition from Colostrum to Milk

Zhang, Le-Ying,Wang, Jia-Qi,Yang, Yong-Xin,Bu, Deng-Pan,Li, Shan-Shan,Zhou, Ling-Yun Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.2

Bovine whey protein expression patterns of colostrum are much different from that of milk. Moreover, bovine colostrum is an important source of protective, nutritional and developmental factors for the newborn. However, to our knowledge, no research has been performed to date using a comparative proteomic method on the changes in the bovine whey proteome during the transition from colostrum to milk. This study therefore separated whey protein of days 1, 3, 7 and 21 after calving using two dimension electrophoresis. Differentially expressed proteins at different collection times were identified using high-performance liquid chromatography in tandem with mass spectrometry (LC/MS) and validated by enzyme-linked immunosorbent assay (ELISA) in order to understand the developmental changes in the bovine whey proteome during the transition from colostrum to milk. The expression patterns of whey protein of days 1 and 3 post-partum were similar except that immunoglobulin G was down-regulated on day 3, and four proteins were found to be down-regulated on days 7 and 21 compared with day 1 after delivering, including immunoglobulin G, immunoglobulin M, albumin, and lactotransferrin, which are involved in immunity and molecule transport. The results of this study confirm the comparative proteomic method has the advantage over other methods such as ELISA and immunoassays in that it can simultaneously detect more differentially expressed proteins. In addition, the difference in composition of milk indicates a need for adjustment of the colostrum feeding regimen to ensure a protective immunological status for newborn calves.

Excess trehalose and glucose affects chitin metabolism in brown planthopper (Nilaparvata lugens)

Qi-Da Shen,Meng-Meng Yang,Guo-Qiang Xie,Hui-JuanWang,Lu Zhang,Ling-Yu Qiu,Shi-GuiWang,Bin Tang 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

Trehalose is a non-reducing disaccharide that is hydrolyzed by trehalase to yield two glucose molecules. Trehalase is the first enzyme involved in the chitin biosynthesis pathway, and it plays a pivotal role in insect growth and molting. In this study, Nilaparvata lugens, an economically important rice pest in Southeast Asia, was injectedwith trehalose or glucose to investigate their effects on chitin metabolism. Excess trehalose and glucose significantly increased the rate of deformity (molting and/or wing deformities) and mortality in N. lugens. Trehalose, glycogen, and glucose contents were also significantly decreased in N. lugens treated with trehalose or glucose. Chitin content and the expression of NlHK, NlUAP, NlG6PI1, NlGFAT, NlGNPNA, NlPGM1, NlPGM2, NlCHS1, NlCHS1a, NlCHS1b, NlCht3, NlCht4, NlCht6, and NlCht7 were significantly decreased, whereas the expression of NlCht2, NlIDGF, and NlENGase was significantly increased in treated insects. Furthermore, a significant increase in the expression of NlTRE1-1, NlTRE2, and NlTPS1 and a decrease, in the expression of NlTPS2 were observed. Results of this study suggested that excess trehalose and glucose could affect chitin metabolism by regulating the expression of pivotal genes to decrease the chitin content, resulting in the inability of N. lugens to complete its molting process.

Streptococcus pneumoniae aminopeptidase N contributes to bacterial virulence and elicits a strong innate immune response through MAPK and PI3K/AKT signaling

Ling Wang,Xuemei Zhang,Guangying Wu,Yuhong Qi,Jinghui Zhang,Jing Yang,Hong Wang,Wenchun Xu 한국미생물학회 2020 The journal of microbiology Vol.58 No.4

Streptococcus pneumoniae is a Gram-positive pathogen with high morbidity and mortality globally but some of its pathogenesis remains unknown. Previous research has provided evidence that aminopeptidase N (PepN) is most likely a virulence factor of S. pneumoniae. However, its role in S. pneumoniae virulence and its interaction with the host remains to be confirmed. We generated a pepN gene deficient mutant strain and found that its virulence for mice was significantly attenuated as were in vitro adhesion and invasion of host cells. The PepN protein could induce a strong innate immune response in vivo and in vitro and induced secretion of IL-6 and TNF-α by primary peritoneal macrophages via the rapid phosphorylation of MAPK and PI3K/AKT signaling pathways and this was confirmed using specific pathway inhibitors. In conclusion, PepN is a novel virulence factor that is essential for the virulence of S. pneumoniae and induces host innate immunity via MAPK and PI3K/AKT signaling.

Development and application of rock breaking platform with variable cross section extrusion pulsed water jet

Yangkai Zhang,Yiyu Lu,Jiren Tang,Yuanfei Ling,Lei Wang,Qi Yao,Zhidan Zhu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

Based on the theory of hydraulic self-reversing and pressurization, a variable cross-section squeeze pulse water jet rock breaking platform was built. When the nozzle diameter is 0.5 mm, the granite erosion and crushing experiments under different driving pressures are carried out, and the depth, volume and specific energy consumption of the erosion pit are analyzed. The results show that the device can achieve intermittent injection after pressurizing the input fluid at a rate of 5.8 times. Meanwhile, the pressurization process of fluid is divided into ascending section, stable section and descending section. Compared with the continuous water jet with the same peak output pressure, the depth of destroyed granite is increased by 129 %-288 %, the volume of broken granite is increased by 37 %-121 %, and the specific energy consumption per unit of crushing volume is reduced by 21 %-74 %. The device can use low-pressure fluid to effectively crush granite.