Shear Resistance Prediction of Post-fire Reinforced Concrete Beams Using Artificial Neural Network

Bin Cai,Long-Fei Xu,Feng Fu 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.6

In this paper, a prediction method based on artificial neural network was developed to rapidly determine the residual shear resistance of reinforced concrete (RC) beams after fire. Firstly, the temperature distribution along the beam section was determined through finite element analysis using software ABAQUS. A residual shear strength calculation model was developed and validated using the test data. Using this model, 384 data entries were derived for training and testing. The input layer of neural network involved parameters of beam height, beam width, fire exposure time, cross-sectional area of stirrup, stirrup spacing, concrete strength, and concrete cover thickness. The output was the shear resistance of RC beams. It was found that use of BP neural network could precisely predict the post-fire shear resistance of RC beams. The predicted data were highly consistent with the target data. Thus, this is a novel method for computing post-fire shear resistance of RC beams. Using this new method, further investigation was also made on the effects of different parameters on the shear resistance of the beams.

Distribution Characteristics of 3,369 Chinese Colorectal Cancer Patients for Gender, Age, Location and Tumor Size During Colonoscopy

Cai, Bin,Wang, Mu-Yong,Liao, Kai,Xu, Yan-Song,Wei, Wei-Yuan,Zhuang, Yuan,Zhang, Sen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Background: Studies have shown the existence of gender- and age-related differences in the incidence and anatomic distribution of colorectal cancers. The purposes of this study were to analyze the distribution characteristics of colorectal cancer patients regarding gender, age, location and tumor size in the course of colonoscopy. Materials and Methods: All colorectal cancer patients who underwent colonoscopy in the First Affiliated Hospital of Guangxi Medical University from 2003 to 2012 were included in our retrospective study. Demographic information (age and gender) and colonoscopy report information (tumor size and location) were collected and analyzed. To compare the gender differences in tumor location and tumor size, as well as the size differences in tumor location, the chi-square test was used. Results: A total of 3, 369 colorectal cancer patients (2, 007 men vs 1, 362 women) were included in our study. Statistical analysis showed there was no gender difference in the anatomic distribution of the tumors (p>0.05). However, there was a gender difference in tumor size (p<0.05). In addition, our study found there was a significant difference in tumor size between rectal and colon tumors (p<0.001). Conclusions: There was no gender difference in the anatomic distribution of colorectal tumors. In addition, tumors observed in men were larger than in women.

Postfire reliability analysis of axial load bearing capacity of CFRP retrofitted concrete columns

Cai, Bin,Hao, Liyan,Fu, Feng Techno-Press 2020 Advances in concrete construction Vol.10 No.4

A reliability analysis of the axial compressive load bearing capacity of postfire reinforced concrete (RC) columns strengthened with carbon fiber reinforced polymer (CFRP) sheets was presented. A 3D finite element (FE) model was built for heat transfer analysis using software ABAQUS. Based on the temperature distribution obtained from the FE analysis, the residual axial compressive load bearing capacity of RC columns was worked out using the section method. Formulas for calculating the residual axial compressive load bearing capacity of the columns after fire exposure and the axial compressive load bearing capacity of postfire columns retrofitted with CFRP sheets were developed. Then the Monte Carlo method was used to analyze the reliability of the axial compressive load bearing capacity of the RC columns retrofitted with CFRP sheets using a code developed in MATLAB. The effects of fire exposure time, load ratio, number of CFRP layers, concrete cover thickness, and longitudinal reinforcement ratio on the reliability of the axial compressive load bearing capacity of the columns after fire were investigated. The results show that within 60 minutes of fire exposure time, the reliability index of the RC columns after retrofitting with two layers of CFRPs can meet the requirements of Chinese code GB 50068 (GB 2001) for safety level II. This method is effective and accurate for the reliability analysis of the axial load bearing capacity of postfire reinforced concrete columns retrofitted with CFRP.

Bond behavior of PP fiber-reinforced cinder concrete after fire exposure

Bin Cai,Ansheng Wu,Feng Fu 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.2

To reduce the damage of concrete in fire, a new type of lightweight cinder aggregate concrete was developed due to the excellent fire resistance of cinder. To further enhance its fire resistance, Polypropylene (PP) Fibers which can enhance the fire resistance of concrete were also used in this type of concrete. However, the bond behavior of this new type of concrete after fire exposure is still unknown. To investigate its bond behavior, 185 specimens were heated up to 22, 200, 400, 600 or 800ºC for 2 h duration respectively, which is followed by subsequent compressive and tensile tests at room temperature. The concreterebar bond strength of C30 PP fiber-reinforced cinder concrete was subsequently investigated through pull-out tests after fire exposure. The microstructures of the PP fiber-reinforced cinder concrete and the status of the PP fibre at different temperature were inspected using an advanced scanning electron microscopy, aiming to understand the mechanism of the bonding deterioration under high temperature. The effects of rebar diameter and bond length on the bond strength of PP fiber-reinforced cinder concrete were investigated based on the test results. The bond-slip relation of PP fiber-reinforced cinder concrete after exposure at different temperature was derived based on the test results.

Finite Element Analysis and Calculation Method of Residual Flexural Capacity of Post-fire RC Beams

Bin Cai,Bo Li,Feng Fu 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.6

Fire tests and subsequent bending tests of four reinforced concrete (RC) beams were performed. Based on these tests, the post-fire performance of RC beams was further studied using finite-element simulation through reasonable selection of suitable thermal and thermodynamic parameters of steel and concrete materials. A thermodynamic model of RC beams with three sides under fire was built using finite-element analysis (FEA) software ABAQUS. The FEA model was validated with the results of fire tests. Different factors were taken into account for further parametric studies in fire using the propsed FE model. The results show that the main factors affecting the fire resistance of the beams are the thickness of the concrete cover, reinforcement ratio of longitudinal steel, the fire exposure time and the fire exposure sides. Based on the strength reduction formula at high temperature of steel and concrete and four test results, an improved section method was proposed to develop a calculation formula to calculate the flexural capacity of RC beams after fire. The theoretical calculation method proposed in this paper shows good agreement with FEA results, which can be used to calculate the flexural capacity of RC beams after fire.

중국 조선족 소설에 나타난 한족 형상 연구

채빈(Cai, Bin) 순천향대학교 인문학연구소 2018 순천향 인문과학논총 Vol.37 No.3

본고는 중국 조선족 소설에 나타난 한족 형상에 대한 연구를 통하여 한족 형상에 투영된 조선족 디아스포라 ‘ (diaspora)’들의 자아 형상 및 그들의 정체성에 대해 파헤쳐보고자 하였다. 이를 좀 더 구체적으로 정리하면 첫째, 2000년 이후 중국 조선족 문단의 수상작들인 김금희의 ｢월광무｣, 최국철의 ｢어느 여름날｣과 ｢왕씨｣, 박옥남의 ｢마이허｣,우광훈의 ｢커지부리｣, 류정남의 ｢이웃집 널다란 울안｣등 여섯 편의 조선족 소설 을 중심으로 작품 속에 나타난 한족 형상에 초점을 맞추어 살펴보고, 둘째, ‘타자 (The other)’라는 거울에 비춰진 조선족 디아스포라들의 자아 형상 및 그들의 정체성이 조선족 소설 속에 어떻게 녹아있는지 살펴보고자 하였다. 연구방법으로는 주로 비교문학 형상학 방법론을 도입하였다. 모든 ‘타자’ 형상이 형성될 때 반드시 자아 형상의 형성을 동반하게 된다. 조선족 소설에 나타난 한족 형상은 조선족이 중국에서의 삶과 그 시대상을 ‘한족’이라는 타자를 통해 반영했다는 것과 더 중요하게는 타자라는 한족 형상에 투영된 조 선족 디아스포라들의 자아 형상, 나아가 그들의 정체성을 확인할 수 있다는 점에서 의의를 가진다. This paper examines the various images of the Han Chinese shaped in Korean-Chinese novels. By studying award-winning works since 2000, it analyzes the effects Chinese images play in the works. Specifically, this paper presents the characterization of the Chinese shaped in Korean-Chinese novels since 2000. It analyzes how self-images of the Korean–Chinese are characterized seen through the mirror of the Chinese, who are called “the other”. Furthermore, it examines what kind of new cognitive changes the Korean-Chinese diaspora identity have brought, and how they’ve perceived them. Focusing on the images of the Chinese shaped in the Korean-Chinese novels since 2000, this paper aims to get the answer of what do the Chinese look like in the eyes of the Korean-Chinese people? How the image of the Chinese are changing in Korean-Chinese novels? What’s more, it deals with what the Korean-Chinese writers are trying to suggest through the images of the Chinese.

Intensity-Modulated Radiotherapy versus Three-Dimensional Conformal Radiotherapy in Definitive Chemoradiotherapy for Cervical Esophageal Squamous Cell Carcinoma: Comparison of Survival Outcomes and Toxicities

Nai-Bin Chen,Bo Qiu,Jun Zhang,Meng-Yun Qiang,Yu-Jia Zhu,Bin Wang,Jin-Yu Guo,Ling-Zhi Cai,Shao-Min Huang,Meng-Zhong Liu,Qun Li,Yong-Hong Hu,Qi-Wen Li,Hui Liu 대한암학회 2020 Cancer Research and Treatment Vol.52 No.1

Purpose The purpose of this study was to compare the survival and toxicities in cervical esophageal squamous cell carcinoma (CESCC) treated by concurrent chemoradiothrapy with either three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) techniques. Materials and Methods A total of 112 consecutive CESCC patients were retrospectively reviewed. 3D-CRT and IMRT groups had been analyzed by propensity score matching method, with sex, age, Karnofsky performance status, induction chemotherapy, and tumor stage well matched. The Kaplan- Meier method and Cox proportional hazards model were used for overall survival (OS) and progression-free survival (PFS). Toxicities were compared between two groups by Fisher exact test. Results With a median follow-up time of 34.9 months, the 3-year OS (p=0.927) and PFS (p=0.859) rate was 49.6% and 45.8% in 3D-CRT group, compared with 54.4% and 42.8% in IMRT group. The rates of grade ! 3 esophagitis, grade ! 2 pneumonitis, esophageal stricture, and hemorrhage were comparable between two groups, while the rate of tracheostomy dependence was much higher in IMRT group than 3D-CRT group (14.3% vs.1.8%, p=0.032). Radiotherapy technique (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.01 to 0.79) and pretreatment hoarseness (HR, 0.12; 95% CI 0.02 to 0.70) were independently prognostic of tracheostomy dependence. Conclusion No survival benefits had been observed while comparing IMRT versus 3D-CRT in CESCC patients. IMRT with fraction dose escalation and pretreatment hoarseness were considered to be associated with a higher risk for tracheostomy dependence. Radiation dose escalation beyond 60 Gy should be taken into account carefully when using IMRT with hypofractionated regimen.

Potential Application of Spice and Herb Extracts as Natural Preservatives in Cheese

Bin Shan,Yi-Zhong Cai,John D. Bro,Harold Corke 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.3

This study investigated the antibacterial efficiency of five spice and herb extracts (cinnamon stick, oregano, clove, pomegranate peel, and grape seed) against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica in cheese at room temperature (~23°C). The lipid oxidation (thiobarbituric acid-reactive substances) of cheese was periodically tested by oxidative analyses. The results showed that all five plant extracts were effective against three foodborne pathogens in cheese. Treatments with these extracts increased the stability of cheese against lipid oxidation. Clove showed the highest antibacterial and antioxidant activity. The reduction of foodborne pathogen numbers and the inhibition of lipid oxidation in cheese indicated that the extracts of these plants (especially clove) have potential as natural food preservatives.

A Theoretical and Experimental Study of the Evaporation Rate of Methanol Droplets on a Horizontal Surface

BIN LIU,BIHAO CAI,YUN SU,XIAOYONG DONG 대한설비공학회 2013 International Journal Of Air-Conditioning and Refr Vol.21 No.3

The evaporation of droplet on a substrate is a hot topic. Considering the droplet shape as a spherical cap, the equations about the droplet evaporation rate of the constant contact angle stage, the constant contact diameter stage and the transitional stage are theoretically analyzed and veri¯ed by experiments. The results show that three stages are shown in the evaporation process, and the evaporation rates in these three stages coincident with the theoretical conclusion. In the constant contact angle stage, the evaporation rate is proportional to the square of base radius. While in the constant contact diameter stage, the evaporation rate is proportional to the cube of base radius. The evaporation rate in the transitional stage approximates to that of the constant contact angle stage.

Estimation of the load-deformation responses of flanged reinforced concrete shear walls

Bin Wang,Qingxuan Shi,Wen-Zhe Cai,YI-Gong Peng 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.5

As limited well-documented experimental data are available for assessing the attributes of different deformation components of flanged walls, few appropriate models have been established for predicting the inelastic responses of flanged walls, especially those of asymmetrical flanged walls. This study presents the experimental results for three large-scale T-shaped reinforced concrete walls and examines the variations in the flexural, shear, and sliding components of deformation with the total deformation over the entire loading process. Based on the observed deformation behavior, a simple model based on moment-curvature analysis is established to estimate flexural deformations, in which the changes in plastic hinge length are considered and the deformations due to strain penetration are modeled individually. Based on the similar gross shapes of the curvature and shear strain distributions over the wall height, a proportional relationship is established between shear displacement and flexural rotation. By integrating the deformations due to flexure, shear, and strain penetration, a new load-deformation analytical model is proposed for flexure-dominant flanged walls. The proposed model provides engineers with a simple, accurate modeling tool appropriate for routine design work that can be applied to flexural walls with arbitrary sections and is capable of determining displacements at any position over the wall height. By further simplifying the analytical model, a simple procedure for estimating the ultimate displacement capacity of flanged walls is proposed, which will be valuable for performance-based seismic designs and seismic capacity evaluations.