Test Study on the Air Permeability of Remolded Q3 Malan Loess

Jia Liu,Xi’an Li,Zeze Guo,Quan Xue,Li Wang,Jinyang Liu 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

Gas permeability is an important parameter in the determination of the pore structure characteristics of loess, especially in engineering fields such as earthwork and landfill cover treatment. With an improved ZC-2015 air permeameter, the air permeability (ka) testing under different water contents (w), dry densities (ρd) and wetting paths was conducted on remolded Q3 Malan loess from the Chanhe River area in Xi’an, Shaanxi, China. The results indicate that the ka of the remolded loess decreased rapidly as ρd increased and exhibited a relatively complex pattern as w increased. When w was less than the plastic limit (wp) and ρdwas relatively low (1.35 g·cm−3, 1.45 g·cm−3), ka decreased as we increased. When ρd reached a certain value (1.50 g·cm−3, 1.65 g·cm−3), the ka–we curve exhibited a notable turning point. When ρd continued to increase 1.70 g·cm−3, ka decreased as we increased. The results of microscopic analysis, suggested that under the action of different water content and compaction, levels of aggregates and pore structures were formed. A Poulsen model was used to predict the ka and the test results were in relatively coincident with the calculation results, demonstrating that the Poulsen model is applicable.

Recommendations on management of gynecological malignancies during the COVID-19 pandemic: perspectives from Chinese gynecological oncologists

Yingmei Wang,Shiqian Zhang,Lihui Wei,Zhongqiu Lin,Xinyu Wang,Jianliu Wang,Keqin Hua,Manhua Cu,Jiandong Wang,Shixuan Wang,Wen Di,Yudong Wang,Ruifang An,Mingrong Xi,Ruixia Guo,Qi Zhou,Xing Xie,Fengxia X 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.4

The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratorysyndrome coronavirus 2 has rapidly spread globally. Cancer patients are at a higher risk ofbeing infected with the coronavirus and are more likely to develop severe complications, ascompared to the general population. The increasing spread of COVID-19 presents challengesfor the clinical care of patients with gynecological malignancies. Concerted efforts should beput into managing gynecological malignancies in an orderly manner by strictly implementingthe measures that are specifically developed for controlling the spread of COVID-19. We havedrafted Recommendations on Management of Gynecological Malignancies during the COVID-19 Pandemicbased on our experience on controlling COVID-19 pandemic in China. We recommendthat patients with gynecological malignancies should be managed in hierarchical andindividualized manners in combination with local conditions related to COVID-19. Medicalcare decision should be balanced between controlling COVID-19 pandemic spread and timelydiagnosis and treatment for gynecologic oncology patients.

Investigation of the Structural Behaviour of RC Beam-Column Sub-frame Subjected to Progressive Collapse

Feiliang Wang,Sandeep Shah,Xiaoping Wang,Xing-Er Wang,Wang-Xi Zhang,Bo Pang,Jian Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

The aim of this study is to investigate the effects of varying design variables on the structural behaviour of reinforced concrete (RC) sub-frames under progressive collapse. A finite element modelling approach is presented and validated against the experimental results concerning a 2D frame (3 columns and 2 beams) and a 3D frame (4 columns and 3 beams). The performance of the RC sub-frame is discussed by choosing the scenarios of the exterior, interior, and multiple column loss, respectively, and by increasing the number of stories and bays. Further studies are conducted based on the numerical method to reveal the effect of beam longitudinal reinforcement ratio (BLRR), beam section depth (BSD), and concrete compression strength (CCS). The results show that both BLRR, CCS and BSD have a significant influence on the compressive arch action (CAA) capacity of the structure under progressive collapse, and the load-carrying capacity of the RC sub-frame increases with an increasing number of stories.

Trajectory tracking control of a 2-DOF manipulator using computed torque control combined with an implicit lyapunov function method

Xi Wang,Baolin Hou 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6

A combined control method based on computed torque control and an implicit Lyapunov function method for trajectory tracking controlling of a 2-DOF manipulator was investigated. The manipulator works under condition of random base vibration and payload uncertainty. Base vibration acts on the manipulator in two directions: in vertical direction and in pitching direction. The computed torque control employed here aims to linearize the strongly nonlinear coupling manipulator system, and also to decouple it. Implicit Lyapunov function control method is one type of continuous feedback control. Its control gains are differentiable function of system error variables, and as the system error variables tend to zero, control gains will turn to infinite. Even so, this method can guarantee the control forces bounded in norm through the control process. The combined method is analyzed based on analytical models of manipulator system, which are established via second kind Lagrange equation. Specially, the analytical models are established according to base vibration in two directions. Numerical simulation results show that the combined control method has strong robustness against random base vibration in both direction and payload uncertainty. Besides, under all conditions considered in this paper, the method can always have fast convergence and high tracking accuracy.

The Application of IMAQ Vision Builder in the Automatic Industrial Inspection of LED

Wang Xi,Kil To Chong 제어로봇시스템학회 2008 제어로봇시스템학회 합동학술대회 논문집 Vol.2008 No.12

Experimental Investigation of Ozone Decomposition in Diesel Particulate Filter Regeneration with Non-Thermal Plasma Technology

Wang Weikai,Cai Yi-xi,Shi Yunxi,Wang Jing,Zhao Nan,Ji Liang 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4

A non-thermal plasma (NTP) reactor was used to generate ozone for diesel particulate filter (DPF) regeneration. The kinetic mechanism of ozone thermal decomposition reaction is explored, and the effect of temperature on the change of ozone concentration is analyzed. The changes of the internal temperature and the concentration of regeneration products such as CO2 and CO during the regeneration under constant temperature and non-constant temperature conditions are then studied and the influence of different regeneration environments on the regeneration is analyzed in combination with the decomposition law of ozone. In the non-constant temperature condition, DPF surface temperature changes significantly with time. The results show that when using an NTP reactor to generate ozone, the activation energy of the decomposition reaction is 2.80755 × 104 J/mol and the law of thermal decomposition reaction can be described as 190.76 . /. During DPF regeneration, the overall regeneration rate and ozone utilization rate in the nonconstant temperature environment are higher than in the constant temperature environment and the temperature change (delta-T) peak rises with the increase of PM deposition. The regeneration with NTP under non-constant thermal condition is an effective way to improve the efficiency of DPF regeneration.

Assessing the Deformity of Cleft Lip Nose Based on Neural Network

Xi, Wang,Vista IV, Felipe,Kim, Deok-Won,Chong, Kil-To 한국정밀공학회 2010 International Journal of Precision Engineering and Vol.11 No.3

The physical appearance of the nostril is important in the objective assessment of a cleft-lip patient while an objective quantitative evaluation is necessary to improve the result of the surgical procedure. The use of Kendall's coefficient of concordance (W) to identify consistency between several raters is proposed in this paper. Linear regression method was then compared with the Neural Network method to find out which is better in determining the consistency of data. The feature factors were extracted from a digital image of the nostril taking into consideration symmetry as the basis. Statistical and Neural Network methods were utilized to process and analyze the deformity assessment data. Two groups of raters were chosen to evaluate the deformity of the cleft lip/cleft nose based on photos shown to them. The angles and distance were measured with respect to the symmetrical aspect and the elementary reference score and factors were obtained through statistical analysis. Linear regression equations describing the relationship between the selected factors and the elementary score were formulated in order to obtain a more reliable reference data. The target data was pre-processed to achieve a more consistent and stable performance. A Neural Network was used to predict the evaluation score and it performed better than the linear regression method under certain conditions. The proposed method can give an objective evaluation to help surgeons evaluate their performance after a surgical procedure and find out if there is a need for further procedures to be done with lesser computational requirement over other existing three-dimensional algorithms.

Enhancement of Mechanical and Antimicrobial Properties of Thermoplastic Poly(lactic acid)/Quaternized Chitosan-Saponite Nanocomposites

Xi Xi,Weijun Zhen,Shengzhen Bian,Wentao Wang 한국고분자학회 2015 폴리머 Vol.39 No.4

Water-soluble N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) was prepared with 2, 3-epoxypropyl trimethyl ammonium chloride grafting to the amino groups of chitosan. Then, chitosan quaternary ammonium intercalated saponite (HTCC-saponite) was synthesized with HTCC and saponite by ultrasonication intercalation. Compared with chitosan, HTCC had a good antibacterial effect. Thermoplastic poly(lactic acid) (PLA)/HTCC-saponite nanocomposites were prepared with HTCC-saponite and PLA by melt intercalation. Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) showed that HTCC was successfully synthesized by a modified method of two-step reaction. Moreover, X-ray diffraction (XRD) and scanning electron microscope (SEM) also showed that saponite was intercalated or nearly exfoliated by HTCC. It was shown the mechanical properties of PLA/HTCC-saponite nanocomposites attained the optimum when the content of HTCC-saponite was 1 phr. The studies of thermal stability, crystallization and rheological behavior of PLA/HTCC-saponite nanocomposites demonstrated that PLA/HTCC-saponite nanocomposites exhibited high performance compared with PLA.

Structural Stability and Electronic and Optical Properties of Coinage-Metal (4; 2) Alloy Nanotubes: A First-Principles Study

Xi-Zhi Wang,Liang-Cai Ma,Ling Ma,Xue-Ling Lin,Jian-Min Zhang 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.6

Using rst-principles calculations, we have systematically investigated the structural stability and the electronic and optical properties of bimetallic AgAu, CuAu, and CuAg (4; 2) alloy nanotubes (NTs). We found that the tip-suspended AgAu and CuAu alloy NTs were stable structures due to the existence of local minima in both the binding energies and the string tensions variation with their unit-cell lengths and that the stability was enhanced when the content of Au was increased. However, a tip-suspended CuAg alloy NT would be difficult to form in future experiments. We also found that both the relativistic effect of elemental gold and the string tension applied by the tip contacts play important roles in suppressing effectively the self-purication effect, leading to the formation of these coinage alloy NTs. The quantum conductance of the stable alloy NTs is increased by 1G0 as compared with that of the corresponding pure coinage-metal NTs.

Role of Centromere Protein H and Ki67 in Relapse-free Survival of Patients after Primary Surgery for Hypopharyngeal Cancer

Wang, Jun-Xi,Zhang, Ying-Yao,Yu, Xue-Min,Jin, Tong,Pan, Xin-Liang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Purpose: Centromere protein H (CENP-H) and Ki67 are overexpressed in some malignancies, but whether they are predictors of survival after primary resection for hypopharyngeal squamous cell carcinoma (HSCC) remains unknown. Methods: We assessed immunohistochemical expression of CENP-H and Ki67 in 112 HSCC specimens collected between March 2003 and March 2005 for analysis by clinical characteristics. The Kaplan-Meier method was used to analyze relapse-free survival and logistic multivariate regression to determine risk factors of relapse-free survival. Cholecystokinin octapeptide assays and flow cytometry were used to examine cell proliferation and apoptosis after siRNA inhibition of CENP-H in HSCC cells. Results: Overall, 50 (44.6%) HSCC specimens showed upregulated CENP-H expression and 69 (61.6%) upregulated Ki67. An increased CENP-H protein level was associated with advanced cancer stage and alcohol history (P=0.012 and P=0.048, respectively) but an increased Ki67 protein level only with advanced cancer stage (P=0.021). Increased CENP-H or Ki67 were associated with short relapse-free survival (P<0.001 or P=0.009, respectively) and were independent predictors of relapse-free survival (P=0.001 and P=0.018, respectively). siRNA knockdown of CENP-H mRNA inhibited cell proliferation and promoted cancer cell apoptosis in vitro. Conclusions: Upregulated CENP-H and Ki67 levels are significantly associated with short relapse-free survival in HSCC. These factors may be predictors of a relapsing phenotype in HSSC cases.