Engineering Characteristics and Reinforcement Program of Inclined Pre−stressed Concrete Pipe Piles

De-quan Zhou,Chen-xi Feng 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.9

When it comes to the deep soft soil foundation, improper construction, preloading, and excavation may result in the inclination of the pre−stressed concrete pipe (PCP) piles. Lack of understanding on deformation characteristics may lead to inaccurate reinforcement plan, thereby causing new engineering accidents. This study analyzes an engineering accident induced by the pile inclination, based on which the finite element method model is built. Deformation characteristics of the foundation incorporating inclined PCP piles are investigated, and the reinforcement program involving placement of the pile with opposite inclination is proposed and compared with the conventional reinforcement program using vertical piles. Findings of this study are two−folds: 1) A critical inclination angle affecting the vertical settlement exists, below which the pile inclination has limited effects upon the vertical load bearing capacity of the foundation. 2) The vertical subsidence, the lateral displacement and the bending moment of the reinforcement program based on the reversely inclined pile are all decreased, which helps bear the overburden load and improve stability. In the process of engineering accident treatment, the bearing capacity of PCP piles with small inclination angles can be first reduced according to their inclination angles, followed by judgement that whether these PCP piles meet the requirements on bearing capacity. The PCP piles with large inclination angles must be strengthened, and the reverse inclined PCP piles are recommended.

A novel method for identifying rotor-stator rubbing positions using the cepstrum analysis technique

Guo Chen,Yong-Quan Liu,Guang-Yi Jiang,Cheng-Gang Li,Guo-Quan Feng,De-You Wang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

A novel method of aero-engine rubbing positions identification based on cepstrum analysis is proposed, and the transfer path characteristicswhich reflect the transfer characteristics information from rubbing points to casing measuring points are separated from the vibrationacceleration signals of casing by means of cepstrum analysis. Therefore, there is different transfer characteristics information atdifferent rubbing positions, and in view of this, twenty rubbing positions identification features from the cepstrum are extracted. A largenumber of rubbing experiments of different positions are simulated with the rotor experiment rig of aero-engine, and the characteristicanalysis of experimental samples at different rubbing positions is carried out, and the results indicate the consistency of features to thesame rubbing position and the difference of the features to the different rubbing positions. Finally, the aero-engine rubbing positionsidentification is carried out using the nearest neighbor classification method, the recognition rate reaches 100%, and the effectiveness ofthe method is full verified.

Structure and property of a vertical cutting Ca0.4Sr0.6Bi4Ti4O15 ferroelectric ceramic

Su-Hua Fan,Ran Yu,Feng-Qing Zhang,Quan-De Che,Wei Hu 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.3

Ca0.4Sr0.6Bi4Ti4O15 ceramics with a-axis preferred orientation were prepared by a solid-state reaction method. The cylindrical Ca0.4Sr0.6Bi4Ti4O15 ceramics were cut into two types of plates: one was along the cylinder axis (A), and the other was perpendicular to the direction of the cylinder axis. The effects of sintering temperature on the structure and electrical properties of the Ca0.4Sr0.6Bi4Ti4O15 ceramics were investigated. When the sintering temperature was 1180 oC, sample A gave the highest a-axis (200) orientation with a value of about 27.1%. At this sintering temperature, sample A showed better dielectric properties and ferroelectric properties, the relative dielectric constant (εr), dielectric loss (tan δ), remnant polarization (Pr), and coercive field (Ec) were 217.6, 0.0027, 14.2 μC/cm2 and 49.6 kV/cm, respectively.

Prevalence of Spina Bifida Occulta and Its Relationship With Overactive Bladder in Middle-Aged and Elderly Chinese People

Jun Wei Wu,Yu Rong Xing,Yi Bo Wen,Tian Fang Li,Quan De Feng,Xiao Ping Shang,Yun Long Li,Jin Jin Feng,Xin Xin Wang,Rong Qun Zhai,Xiang Fei He,Tao Chen,Xin Jian Liu,Jian Guo Wen 대한배뇨장애요실금학회 2016 International Neurourology Journal Vol.20 No.2

Purpose: To investigate the prevalence of spina bifida occulta (SBO) and its relationship with the presence of overactive bladder (OAB) in middle-aged and elderly people in China. Methods: A cross-sectional community-based survey was carried out at 7 communities in Zhengzhou City, China from December 15, 2013 to June 10, 2014, where residents aged over 40 years were randomly selected to participate. All of the participants underwent lumbosacral radiographic analysis and relevant laboratory tests. A questionnaire including basic information, past medical history and present illness, and the OAB symptom score was filled out by all participants. Chi-square tests and logistic regression were used for data analysis with a P-value of <0.05 denoting statistical significance. Results: A total of 1,061 subjects were qualified for the final statistical analysis (58.8±11.7 years; male, 471 [44.4%]; female, 590 [55.6%]). The overall prevalence of SBO was 15.1% (160 of 1,061): 18.3% (86 of 471) in men and 12.5% (74 of 590) in women. Among these subjects, 13.7% (145 of 1,061) had OAB: 13.2% (62 of 471) in men and 14.1% (83 of 590) in women. The results of logistic regression showed that age, SBO, history of cerebral infarction (HCI), and constipation were risk factors for OAB (P<0.05), while sex, history of childhood enuresis (HCE), body mass index (BMI), and diabetes mellitus (DM) were not (P>0.05). In men, age, SBO, and constipation were risk factors for OAB (P<0.05), while HCE, BMI, DM, HCI, and benign prostate hyperplasia were not (P>0.05). In women, age, SBO, and HCI were risk factors for OAB (P<0.05), while HCE, BMI, DM, vaginal delivery, and constipation were not (P>0.05). Conclusions: The prevalence of SBO is high and it is related to OAB in middle-aged and elderly people in China.

An improved horizontally reversible plow design based on virtual assembly semantics and constraint

Lin Zhu,Shuang-Shuang Peng,Yin-Yin Qi,Xi Cheng,Wen-Feng Zhang,Liang-Yuan Xu,De-Quan Zhu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

There exit model errors in the constructed Horizontally reversible plough (HRP) structure through Interference check technique (ICT). This is basically due to missing parts and geometric interference and, hence, has significantly adverse effects in improving HRP. In thispaper an improved design to refine the three dimensional (3D) model of HRP is implemented by using Virtual assembly technology(VAT). To achieve this, the authors propose a combined virtual assembly semantics and constraint for assembly planning and simulationof HRP in the commercial software, e.g., SolidWorks. First, the assembly planning of HRP was captured with a semantics-based model,including spatial position, assembly orientation, type and parameters of the semantic entities; secondly, the assembly simulation of HRPwas performed by using constraint-based VAT, e.g. component grasping, moving and releasing; finally, the obtained HRP model wasverified through ICT again. The results demonstrate that not any model error exists in the refined 3D HRP model any longer and thatsemantics and constrain based VAT can support the interactive operation more effectively and accurately than those with geometric constraints. This technique was previously used for HRP model. Based on the refined 3D HRP model, the design improvement of Remotecylinder base (RCB), an important component of HRP, will be forthcoming in a future paper.

Clinicopathologic Characteristics and Prognoses for Multicentric Occurrence and Intrahepatic Metastasis in Synchronous Multinodular Hepatocellular Carcinoma Patients

Li, Shi-Lai,Su, Ming,Peng, Tao,Xiao, Kai-Yin,Shang, Li-Ming,Xu, Bang-Hao,Su, Zhi-Xiong,Ye, Xin-Ping,Peng, Ning,Qin, Quan-Lin,Chen, De-Feng,Chen, Jie,Li, Le-Qun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the outcomes for patients are still poor. It is important to determine the original type of synchronous multinodular HCC for preoperative assessment and the choice of treatment therapy as well as for the prediction of prognosis after treatment. Aims: To analyze clinicopathologic characteristics and prognoses in patients with multicentric occurrence (MO) and intrahepatic metastasis (IM) of synchronous multinodular hepatocellular carcinoma (HCC). Methods: The study group comprised 42 multinodular HCC patients with a total of 112 nodules. The control group comprised 20 HCC patients with 16 single nodular HCC cases and 4 HCC cases with a portal vein tumor emboli. The mitochondrial DNA (mtDNA) D-loop region was sequenced, and the patients of the study group were categorized as MO or IM based on the sequence variations. Univariate and multivariate analyses were used to determine the important clinicopathologic characteristics in the two groups. Results: In the study group, 20 cases were categorized as MO, and 22 as IM, whereas all 20 cases in the control group were characterized as IM. Several factors significantly differed between the IM and MO patients, including hepatitis B e antigen (HBeAg), cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and the histological grade of the primary nodule. Multivariate analysis further demonstrated that cirrhosis and portal vein and/or microvascular tumor thrombus were independent factors differentiating between IM and MO patients. The tumor-free survival time of the MO subjects was significantly longer than that of the IM subjects ($25.7{\pm}4.8$ months vs. $8.9{\pm}3.1$ months, p=0.017). Similarly, the overall survival time of the MO subjects was longer ($31.6{\pm}5.3$ months vs. $15.4{\pm}3.4$ months, p=0.024). The multivariate analysis further demonstrated that the original type (p=0.035) and Child-Pugh grade (p<0.001) were independent predictors of tumor-free survival time. Cirrhosis (p=0.011), original type (p=0.034) and Child-Pugh grade (p<0.001) were independent predictors of overall survival time. Conclusions: HBeAg, cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and histological grade of the primary nodule are important factors for differentiating IM and MO. MO HCC patients might have a favorable outcome compared with IM patients.