Reliability-based sensitivity of mechanical components with arbitrary distribution parameters

Yimin Zhang,Xiangdong He,Zhou Yang,Qiaoling Liu,Bangchun Wen 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.6

This paper presents a reliability-based sensitivity method for mechanical components with arbitrary distribution parameters. Techniques from the perturbation method, the Edgeworth series, the reliability-based design theory, and the sensitivity analysis approach were employed directly to calculate the reliability-based sensitivity of mechanical components on the condition that the first four moments of the original random variables are known. The reliability-based sensitivity information of the mechanical components can be accurately and quickly obtained using a practical computer program. The effects of the design parameters on the reliability of mechanical components were studied. The method presented in this paper provides the theoretic basis for the reliability-based design of mechanical components.

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.

Deep convolutional neural network: a novel approach for the detection of Aspergillus fungi via stereomicroscopy

Ma Haozhong,Yang Jinshan,Chen Xiaolu,Jiang Xinyu,Su Yimin,Qiao Shanlei,Zhong Guowei 한국미생물학회 2021 The journal of microbiology Vol.59 No.6

Fungi of the genus Aspergillus are ubiquitously distributed in nature, and some cause invasive aspergillosis (IA) infections in immunosuppressed individuals and contamination in agricultural products. Because microscopic observation and molecular detection of Aspergillus species represent the most operator-dependent and time-intensive activities, automated and cost-effective approaches are needed. To address this challenge, a deep convolutional neural network (CNN) was used to investigate the ability to classify various Aspergillus species. Using a dissecting microscopy (DM)/stereomicroscopy platform, colonies on plates were scanned with a 35× objective, generating images of sufficient resolution for classification. A total of 8,995 original colony images from seven Aspergillus species cultured in enrichment medium were gathered and autocut to generate 17,142 image crops as training and test datasets containing the typical representative morphology of conidiophores or colonies of each strain. Encouragingly, the Xception model exhibited a classification accuracy of 99.8% on the training image set. After training, our CNN model achieved a classification accuracy of 99.7% on the test image set. Based on the Xception performance during training and testing, this classification algorithm was further applied to recognize and validate a new set of raw images of these strains, showing a detection accuracy of 98.2%. Thus, our study demonstrated a novel concept for an artificial-intelligence-based and cost-effective detection methodology for Aspergillus organisms, which also has the potential to improve the public’s understanding of the fungal kingdom.

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.

Research on Vibration Characteristics of Spur Gear System with Pitting Fault Considering the Elastohydrodynamic Lubrication Condition

Chunlong Deng,Yimin Shao,Hongling Zheng,Minggang Du,Yang Yang 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

Pitting fault is easily observed in gear system, dynamics models are commonly established to study the vibration characteristics affected by pitting fault. However, most of the dynamics models ignore the elastohydrodynamic lubrication (EHL) in gear system, which plays an important role in early fatigue failure of gears. Therefore, a dynamics model is proposed to study the vibration characteristics of spur gear system with pitting fault based on the three-dimensional line contact elastohydrodynamic lubrication (3D-EHL) model. In this model, both the transverse torsional dynamics model with gear pitting fault and the 3D-EHL model are coupled through an iterative method. Firstly, the transient rolling and sliding velocity, radius of curvature, and dynamic tooth force will be calculated based on the transverse torsional dynamics model, and which are then applied in the 3D-EHL model to perform contact analysis on a single continuously meshing teeth pair. Secondly, the transient pressure and film thickness distribution calculated based on the 3D-EHL model are used to determine the rolling, sliding friction, and viscous damping of the gear pair. After that, these parameters are substituted into the dynamics model to obtain the vibration characteristics of gear system with pitting fault. Finally, different working conditions are compared based on the proposed model, the results show that the EHL has an effect on the vibration characteristics of gear system with pitting fault.

Abnormalities in Inflammatory Cytokines Confer Susceptible to Chronic Neuropathic Pain-related Anhedonia in a Rat Model of Spared Nerve Injury

Xi Fang,Gaofeng Zhan,Jie Zhang,Hui Xu,Bin Zhu,Yimin Hu,Chun Yang,Ailin Luo 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.2

Objective: Patients with chronic neuropathic pain (CNP) have a higher incidence to develop depression. However, its pathogenesis has not yet been fully elucidated. Here we aimed to investigate the role of inflammatory cytokines in CNP-related anhedonia, which is a core symptom of depression, and to explore the effects of ketamine and parecoxib on pain and anhedonia. Methods: A rat model of spared nerve injury (SNI) was constructed to mimic CNP. Hierarchical cluster analysis of sucrose preference test (SPT) was applied to classify the SNI rats into anhedonia susceptible and unsusceptible. Inflammatory cytokines in medial prefrontal cortex (mPFC) of brain, serum and L2-5 spinal cord were measured. Moreover, effects of ketamine or parecoxib on mechanical withdrawal test (MWT) and SPT in anhedonia susceptible rats were detected. Results: Tumor necrosis factor (TNF)- was increased in mPFC, serum and and spinal cord of anhedonia susceptible rats. Furthermore, anhedonia susceptible and unsusceptible rats both increased the interleukin (IL)-1 level in mPFC, serum and spinal cord. IL-6 was altered in serum and spinal cord, but not in mPFC. IL-10 was significantly altered in mPFC and serum, but not in spinal cord. Additionally, ketamine treatment significantly attenuated the decreased results of MWT and SPT in anhedonia susceptible rats, and that parecoxib significantly improved the MWT score, but failed to alter the result of SPT. Conclusion: These findings suggest that abnormalities in inflammatory cytokines confer susceptible to anhedonia in a rat model of SNI. Ketamine, a fast-acting antidepressant, has pharmacological benefits to alleviate pain and anhedonia symptoms.

Feasibility of Two-Screw Anterior Fixation for Odontoid Fractures in a Chinese Population: A Morphometric Study Based on Computed Tomography

Yixiang Ai,Dereje Gobena Alemayehu,Genwen Mao,Yaping Liang,Ran Cao,Jiale Hu,Yimin Yang,Zhiwei Ren 대한정형외과학회 2023 Clinics in Orthopedic Surgery Vol.15 No.6

Background: To evaluate the feasibility of treating odontoid fractures in the Chinese population with two cortical screws based on computed tomography (CT) scans and describe a new measurement strategy to guide screw insertion in treating these fractures. Methods: A retrospective review of cervical computed tomographic scans of 128 patients (aged 18–76 years; men, 55 [43.0%]) was performed. The minimum external transverse diameter (METD), minimum external anteroposterior diameter (MEAD), maximum screw length (MSL), and screw projection back angle (SPBA) of the odontoid process were measured on coronal and sagittal CT images. Results: The mean values of METD and MEAD were 10.0 ± 1.1 mm and 12.0 ± 1.0 mm, respectively, in men and 9.2 ± 1.0 mm and 11.0 ± 1.0 mm, respectively, in women. Both measurements were significantly higher in men (p < 0.001). In total, 87 individuals (68%) had METD > 9.0 mm that could accommodate two 3.5-mm cortical screws. The mean MSL value and SPBA range were 34.4 ± 2.9 mm and 13.5°–24.2°, respectively, with no statistically significant difference between men and women. Conclusions: The insertion of two 3.5-mm cortical screws was possible for anterior fixation of odontoid fractures in 87 patients (68%) in our study, and there was a statistically significant difference between men and women.