The relationship between myofiber characteristics and meat quality of Chinese Qinchuan and Luxi cattle

Lu Xiao,Yang Yuying,Zhang Yimin,Mao Yanwei,Liang Rongrong,Zhu Lixian,Luo Xin 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.4

Objective: The objectives of this study were to explore the expression patterns of myosin heavy chain (MyHC) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of M. longissimus lumborum (LL), M. psoas major (PM), and M. semimembranosus (SM) from Chinese Luxi and Qinchuan cattle. Methods: Three major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem. Results: PM muscle had higher pH value, a* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of MyHC I mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05). Conclusion: According to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber. Objective: The objectives of this study were to explore the expression patterns of myosin heavy chain (<i>MyHC</i>) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of <i>M. longissimus lumborum</i> (LL), <i>M. psoas major</i> (PM), and <i>M. semimembranosus</i> (SM) from Chinese Luxi and Qinchuan cattle.Methods: Three major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem.Results: PM muscle had higher pH value, <i>a</i>* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of <i>MyHC I</i> mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05).Conclusion: According to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber.

Kinetic studies of hemicellulose hydrolysis of corn stover at atmospheric pressure

Yimin Zhang,Xuebin Lu,Ying Liang,Jing Yang,Shuting Zhang,Eiji Suzuki 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.2

The object of this work was to study the xylose production by hydrolysis of corn stover with diluted sulfuric acid at 100 oC. Several concentrations of H2SO4 (2%, 4% and 6% w/w) and reaction time (0-300 min) were evaluated. Kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose and furfural in the hydrolysates were found. Optimal conditions for hydrolysis were 5.5% H2SO4 at 100 oC for 60 min; under these conditions, 86.7% of xylose yield and 2.82 g/g selectivity were attained, leading to liquors containing up to 18.73 g/l xylose, 6.64 g/l glucose and 0.63 g/l furfural. The models could be successfully used to predict the concentrations of xylose, glucose and furfural within 0-300 min under experimental acid concentrations. Furthermore, the hydrolysis process of corn stover using dilute acid could be conceived as the first stage of an integrated strategy for corn stover utilization.

The strength analysis and probabilistic design of a bogie frame with incomplete probabilistic information

Hao Lu,Changyi Wang,Haibao Guo,Hao Lv,Yimin Zhang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

A bogie frame is a key component of high-speed rail; higher requirements of the safety and stability of the bogie frame are put forward with the continuous improvement of the train speed. In this study, we first performed a strength analysis of a bogie frame according to the JIS E 4207 standard by using finite element method. Then, we did a reliability analysis of the bogie frame. The reliability problems are defined as strength reliability and resonant frequency reliability, which indicate the structural safety and stability of the bogie frame. The reliability estimation is realized by experimental design, artificial neural network and stochastic perturbation theory. Additionally, reliability-based sensitivity indices were derived to measure the parameter importance of random input variables. An illustrative example of the bogie frame with incomplete probabilistic information was used to demonstrate the applications of the proposed method for reliability and reliability-based sensitivity estimation in terms of strength and resonant frequency reliability. The results indicate that vertical loads and the material density have more of an impact on reliability than other variables of the bogie frame.

Inverse system optimal control of interleaved boost converters

Dongyi Xiao,Yimin Lu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.6

When compared with the conventional boost converter, the interleaved boost converter (IBC) has the advantages of low current stress. Thus, they have been widely used in DC microgrids. However, the IBC is a multiple input single output (MISO) high-order nonlinear system. To simplify the controller design, a reduced order model of an interleaved boost converter is proposed in this paper. By selecting an appropriate output function, the nonlinear reduced order system is transformed into a pseudo-linear system through the inverse system theory. Then an optimal controller is designed based on the linear quadratic regulator (LQR) theory. As a result, the output voltage can track the reference value. In addition, a current balance controller is designed to balance the interphase inductor current. Simulation results of a 3-phase IBC show that when compared with PI control, the proposed control strategy has better regulation performance. Finally, the correctness and eff ectiveness of the proposed control strategy are further verifi ed by experiment on 2-phase IBC.

Fuzzy self-tuning PID control of MC³ LLC resonant LED drivers

Li, Delong,Lu, Yimin,Ge, Xin The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.5

An MC³ LLC resonant light-emitting diode (LED) driver is a multi-channel constant current (MC³) output solution based on LLC resonance. Through an effective combination of multiple transformers and a DC block capacitor, this driver allows constant current outputs in multiple channels when the LED channels are unbalanced. This study considers a fuzzy self-tuning proportional integral derivative (PID) control strategy that allows for the self-tuning of PID parameters according to fuzzy inference rules designed using the relationship between the current gain and the switching frequency. Thus, when LED channels are unbalanced, the system allows a constant current output for each of the channels and controls the input voltage disturbances well. Simulation and experimental verifications are carried out, and a 20 W 4-channel constant current power supply design based on LLC resonance is obtained for the LED driver. This realizes soft-switching of the switching device, which reduces system loss and improves system efficiency. Moreover, the adjustment time of the proposed method is half that of fixed-parameter control methods, and the overshoot of the proposed method is smaller than that of fixed-parameter control methods. When compared with PID controllers with fixed parameters, the proposed method is more robust. When a system is disturbed, it recovers faster and has a smaller range of current fluctuation with the proposed method.

Motifs of Asian - Pacific International Relations at the Turn of the Century

Ni Shixiong,YiMin Lu 한양대학교 아태지역연구센터 1992 중소연구 Vol.16 No.2

Model predictive control of double-input buck converters

Chen, Yunzhu,Lu, Yimin,Luo, Wei The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.6

The control system of a multiple-input dc-dc converter should ensure the stability of output voltage and reasonably distribute the power of multiple-input voltage sources. In addition, there is mutual coupling between multiple closed control loops, which makes the design of the control system difficult. Based on the ability of model predictive control (MPC) to deal with constraints explicitly, a model predictive control algorithm based on the state-space averaging method is proposed for a double-input buck converter. First, a state-space averaging model of a double-input buck converter is established. Then, considering the power management of two input power supplies, a model predictive controller is designed based on the model by combining the input constraints with the objective function. Both simulation and experimental results show that the system has good steady-state accuracy and fast dynamic response characteristics under the action of model predictive controller.

Primary side control method for constant voltage/current output of series‑none compensated inductive wireless transfer systems

Xin Ge,Yimin Lu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.9

In practical applications, inductive wireless power transfer (IWPT) systems are often required to output a constant voltage or current. However, a change of the load often leads to a change of the output. This paper presents a primary side control method for an IWPT system with the series-none (SN) compensation topology. By using this method, the load, output current, and voltage can be estimated in real time by detecting the output voltage and current of the primary inverter, along with the phase difference between them. This overcomes the disadvantage where the control for a IWPT system requires wireless or wired communication between the primary side and secondary side. Phase shift voltage regulation technology and a PI controller are used to regulate the output voltage or current based on the estimated data. In order to adjust the parameters of the PI controller, a small signal model is established by the generalized state-space averaging (GSSA) method. Finally, simulations and an experimental prototype were established to verify the performance of the primary side control method. The obtained results show that the secondary parameters and variables can be accurately estimated. Under the action of the primary controller, the system can output constant voltage and current values.

Alterations of oral microbiota in Chinese children with viral encephalitis and/or viral meningitis

Li Yijie,Liu Jing,Zhu Yimin,Peng Chunying,Dong Yao,Liu Lili,He Yining,Lu Guoping,Zheng Yingjie 한국미생물학회 2022 The journal of microbiology Vol.60 No.4

The role of oral microbiota in viral encephalitis and/or viral meningitis (VEVM) remains unclear. In this hospital-based, frequency-matched study, children with clinically diagnosed VEVM (n = 68) and those with other diseases (controls, n = 68) were recruited. Their oral swab samples were collected and the oral microbiota was profiled using 16S rRNA gene sequencing. The oral microbiota of children with VEVM exhibited different beta diversity metrics (unweighted UniFrac distance: P < 0.001, R2 = 0.025, Bray-curtis dissimilarity: P = 0.045, R2 = 0.011, and Jaccard dissimilarity: P < 0.001, R2 = 0.017) and higher relative abundances of taxa identified by Linear discriminant analysis (LDA) with effect size (Enterococcus, Pedobacter, Massilia, Prevotella_9, Psychrobacter, Butyricimonas, Bradyrhizobium, etc., LDA scores > 2.0) when compared with the control group. The higher pathway abundance of steroid hormone biosynthesis predicted by oral microbiota was suggested to be linked to VEVM (q = 0.020). Further, a model based on oral microbial traits showed good predictive performance for VEVM with an area under the receiver operating characteristic curve of 0.920 (95% confidence interval: 0.834–1.000). Similar results were also obtained between children with etiologically diagnosed VEVM (n = 43) and controls (n = 68). Our preliminary study identified VEVM-specific oral microbial traits among children, which can be effective in the diagnosis of VEVM.

MOPSO-based Data Scheduling Scheme for P2P Streaming Systems

( Pingshan Liu ),( Yaqing Fan ),( Xiaoyi Xiong ),( Yimin Wen ),( Dianjie Lu ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.10

In the Peer-to-Peer (P2P) streaming systems, peers randomly form a network overlay to share video resources with a data scheduling scheme. A data scheduling scheme can have a great impact on system performance, which should achieve two optimal objectives at the same time ideally. The two optimization objectives are to improve the perceived video quality and maximize the network throughput, respectively. Maximizing network throughput means improving the utilization of peer’s upload bandwidth. However, maximizing network throughput will result in a reduction in the perceived video quality, and vice versa. Therefore, to achieve the above two objects simultaneously, we proposed a new data scheduling scheme based on multi-objective particle swarm optimization data scheduling scheme, called MOPSO-DS scheme. To design the MOPSO-DS scheme, we first formulated the data scheduling optimization problem as a multi-objective optimization problem. Then, a multi-objective particle swarm optimization algorithm is proposed by encoding the neighbors of peers as the position vector of the particles. Through extensive simulations, we demonstrated the MOPSO-DS scheme could improve the system performance effectively.