14 research outputs found
Analysis of Eccentrically Loaded FRP Partially Wrapped Reinforced Concrete Columns Subjected to Combined Environmental Erosion
The Behavior of Eccentrically Loaded Fiber Reinforced Polymer (FRP) Partially Wrapped Reinforced Concrete (RC) Columns under Combined Environmental Erosion Was Investigated in This Paper. Circular RC Columns Were Firstly Subjected to Chloride Erosion Where the Target Corrosion Degree (0, 10 %, and 20 %) is Obtained with Externally Applied Current. This Was Then Followed by Partially Strengthening with 2-Ply of Glass Fiber Reinforced Polymer (GFRP) Strips as Well as 50 Freeze–thaw Cycles. Series of Eccentric Compression Tests Were Conducted with Ranging Eccentricities of 0, 5 Mm, 10 Mm, and 15 Mm. for Comparison, the Carbon Fiber Reinforced Polymer (CFRP) Partially Strengthened Columns with the Corrosion Degree of 10 % and Subjected to 50 Freeze–thaw Cycles Were Also Eccentrically Loaded with an Eccentricity of 10 Mm. Results Showed that with Increasing Corrosion Degree, the Bearing Capacity of GFRP Strengthened Column Showed a 2-Stage Behavior (Firstly Increased and Then Decreased), Which May Be Caused by the Confinement Reduction of FRP on Columns Due to Severe Environmental Erosion. under Small Eccentric Loading, the CFRP Strengthened RC Columns Showed Better Compressive Behavior Than that of GFRP Strengthened RC Columns. based on the Stress–strain Relationship of Constituent Materials, a Simplified Analytical Model Considered the Effects of Chloride and Freeze–thaw Erosion Was Put Forward to Predict the Bearing Capacity of FRP Partially Wrapped RC Column under Eccentric Loading
Application of a Heterogeneous Wireless Framework for Radiation Monitoring in Nuclear Power Plant
Radiation monitoring plays a vital role in the safe and efficient operation of the nuclear power plant (NPP). The current radiation monitoring system (RMS) generally uses cable monitoring network with distributed radiation monitors. It will introduce various compatibility issues that more detector nodes are added to the existing cable monitoring network. The communication protocols from different device manufacturers are not compatible. Furthermore, the original RMS has to be shut down for rewiring and reconstruction. In this paper, a heterogeneous framework is proposed based on the wireless sensor network (WSN) technology for monitoring environmental conditions around and inside NPP, specifically, radiation levels. The proposed full-scope RMS has a no-wiring and no-construction upgraded scheme based on the WSNs, which forms a heterogeneous multi-networks fusion control system, and does not affect the existing NPP radiation monitoring facilities. The introduction of the wireless gateway to build heterogeneous monitoring framework makes it possible to complete the system seamless upgrade with a lower cost and higher feasibility
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Big Data in the Big D
Presentation paper for the 2017 International Conference on Knowledge Management. This paper introduces the study and practice of design knowledge management and knowledge transfer across the design of a newly built nuclear power plant in China
Therapy Effects of Wogonin on Ovarian Cancer Cells
Background. Wogonin is a plant monoflavonoid and has been reported to induce apoptosis of cancer cells and show inhibitory effect on cancer cell growth. However, the detailed and underlying molecular mechanisms are not elucidated. In this study, we investigated the molecular and biological effects of wogonin in human ovarian A2780 cancer cells. Materials and Methods. We determined the effects of wogonin on the changes of cell cycling and apoptotic responses of cells. Western blot analysis was used to measure the effects of wogonin on protein expressions. Results. Our results showed that treatment with wogonin inhibited the cancer cell proliferation, decreased the percentage of G0/G1 subpopulation, and reduced invasiveness of A2780 cells. Exposure to wogonin also resulted in downregulated protein levels of estrogen receptor alpha (ER-α), VEGF, Bcl-2, and Akt and increased expressions of Bax and p53. In addition, exposure to wogonin increased caspase-3 cleavage and induced apoptosis in A2780 cells. Our study further showed that MPP, a specific ER-α inhibitor, significantly enhanced antitumor effects of wogonin in A2780 cells. Conclusion. Our results suggest a potential clinical impact of wogonin on management of ovarian cancer
Fatigue Behavior and Calculation Methods of High Strength Steel Fiber Reinforced Concrete Beam
Adding Steel Fibers into Concrete Was Considered as One of the Most Effective Ways to Restrain the Crack Development and Improve the Stiffness for Reinforced Concrete (RC) Structures. to Explore the Reinforcement Mechanism of Steel Fibers on the Fatigue Behavior of High-Strength RC Beam, Eight High-Strength Steel Fiber Reinforced Concrete (HSSFRC) Beams Subjected to Fatigue Loading Were Tested in This Study. the Main Design Parameters Considered in This Work Were Stress Level and Steel Fiber Content. the Failure Mode, Crack Patterns, Fatigue Life, Crack Width, and Stiffness Degradation of HSSFRC Beams under Fatigue Loading Were Discussed. the Results Showed that Steel Fibers Could Significantly Increase the Fatigue Life, Restrain Crack Development, and Improve Crack Patterns of HSSFRC Beams under Fatigue Loading Compared to Ordinary RC Beams. Both the Crack Width and Stiffness Degradation Rate of Beams Decrease with Increasing Steel Fiber Content. Besides, the Empirical Formulas for Calculating the Maximum Crack Width and Midspan Deflection of HSSFRC Beam under Fatigue Loading Were Proposed and Validated using Experimental Results
Effects of Groove and Steel Fiber on Shear Properties of Concrete with Recycled Coarse Aggregate
In this paper, a series of shear specimens with or without groove were manufactured to mainly analyze the effects of grooves (or shear section height) and steel fibers on the shear properties of concrete with recycled coarse aggregate through double-side direct shear test. In addition, the relationship between the shear strength and the compressive strength and splitting tensile strength of steel fiber reinforced concrete with recycled coarse aggregate (SFRCAC) was also discussed. The experimental results showed that the peak load, deformation corresponding to the peak load and calculated shear strength of the specimens with grooves were lower than those of the specimens without grooves. The steel fiber and recycled coarse aggregate (RCA) had a significant effect on the shear properties of SFRCAC. As the volume content of steel fibers increased, the shear strength of SFRCAC and the corresponding deformation increased gradually. With the replacement ratio of RCA increasing, the shear strength of SFRCAC decreased but the corresponding deformation increased gradually. Finally, the formula for calculating the shear strength of SFRCAC was proposed by analyzing and fitting the test results and the data of related literature
Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device
Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device. Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated. Results. All parameters showed good intraobserver reliability (Cronbach’s alpha; intraclass correlation coefficient, α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated. Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea
Flexural Performance and Stress Calculation of External Prestressed Fiber-Reinforced Polymer-Bar-Strengthened One-Way Concrete Slabs
External prestressing is widely employed in structural strengthening engineering due to its numerous advantages. However, external prestressed steel bars are prone to corrosion when exposed to the service environment. This paper is dedicated to examining the use of fiber-reinforced polymer (FRP) bars as external prestressing materials to strengthen one-way concrete slabs. Five one-way concrete slabs were strengthened with externally prestressed FRP bars with different prestress levels and different amounts of FRP bars, while one non-strengthened slab was used for comparison. The effects of strengthening on the flexural behavior, specifically the cracking load, ultimate load, stiffness and failure mode, were analyzed systematically. Moreover, the ductility and cost–benefit optimizing properties of the reinforcing design were discussed. The results show that external prestressed FRP bars significantly improve the cracking load, ultimate load and stiffness of one-way concrete slabs. The absence of a bond between the concrete and FRP bars overcomes the brittleness of the FRP bars, while the strengthened slabs exhibit satisfactory ductility and a higher post-yield stiffness and bearing capacity. Additionally, the cost/benefit ratio is optimized by increasing the prestress level, while a higher number of prestressed FRP bars is beneficial to ductility. Finally, a method for calculating the stress in prestressed FRP bars at ultimate loads was proposed. Irrespective of the prestressing material, this method is applicable to both strengthened beams and one-way slabs