This paper is concerned with the development of an accurate bond strength model for carbon-fiber-reinforced polymer (CFRP) strips near-surface mounted (NSM) to concrete where debonding occurs as a result of cohesion failure in the adjacent concrete. Based on an existing analytical solution and the fracture energy equation recently developed by the authors, a bond strength equation is first proposed for NSM CFRP strip-to-concrete bonded joints with a sufficient bond length (i.e., the bond length exceeds a threshold value referred to as the effective bond length). The influence of an insufficient bond length on the bond strength is next examined through a parametric study conducted using a beam-spring numerical model in which a bond-slip model recently proposed by the authors is incorporated. Based on the numerical results, expressions are formulated for the effective bond length and the bond-strength reduction factor for insufficient bond lengths. The combination of these equations leads to a new bond strength model for NSM CFRP strip-to-concrete bonded joints. The predictions of the proposed bond strength model are compared with the results of 51 test specimens collected from seven existing studies and the predictions of the only existing bond strength model for such joints. These comparisons indicate that the proposed model is accurate and superior to the existing bond strength model, particularly for joints with insufficient bond lengths. The proposed bond strength model, because of its accuracy and simplicity, can be readily incorporated in design codes and guidelines.
With the resurgence of drugs with covalent binding mechanisms, much attention has been paid to docking methods for the discovery of targeted covalent inhibitors. The existence of many available covalent docking tools has inspired development of a systematic and objective procedure and criteria with which to evaluate these programs. In order to find a tool appropriate to studies of a covalently binding system, protocols and criteria are proposed for protein-ligand covalent docking studies. This paper consists of three sections: (1) curating a standard data set to evaluate covalent docking tools objectively; (2) establishing criteria to measure the performance of a tool applied for docking ligands into a complex system; and (3) creating a protocol to evaluate and select covalent binding tools. The protocols were applied to evaluate four covalent docking tools (MOE, GOLD, CovDock, and ICM-Pro) and parameters affecting covalent docking performance were investigated.
The analytical and experiment research of In-Vessel Corium Retention (IVR) in the Chinese Pressurized-water Reactor 1000 MWe (CPR1000) are introduced. The IVR research consists of preliminary phase and detailed phase. The analysis of thermal failure, structural failure and penetration failure of Reactor Pressure Vessel (RPV) and the experimental research of External Reactor Vessel Cooling (ERVC) are performed at preliminary phase. Analysis results show that the RPV failure is the dominated by thermal failure mode and the probability of the thermal failure is very low. Test results show that the IVR success probability for CPR1000 is about 99% if the Critical Heat Flux (CHF) of CPR1000 is the same as that of AP600. Further works, including the ERVC enhancement design, the CHF test of the RPV outer wall and the recalculation of the IVR success probability for CPR1000, will be performed at detailed phase in the near future.
The first cycles of Ling’ao and Daya Bay Nuclear Power Stations are the same.It is the challenge for Ling’ao NPS to design the fuel management mode and how to utilize the successful experiences from Daya Bay NPS.The fuel management design for the second cycle is rather difficult in normal conditions.There must be clear answers to the questions that whether or not to change the fuel type from the second cycle and which type of fuel to be used for the change(AFA 3G with or without MSMG).If the same fuel type of AFA 3G with MSMG in Daya Bay NPS would be used in Ling’ao second cycle,it would be the mixed core and there should be special safety analysis and licensing issues.This paper introduces the overall optimization and design from cycle 2 to 5.
The flexural strength of reinforced concrete (RC) beams can be effectively increased using either externally bonded (EB) or near-surface mounted (NSM) fibre-reinforced polymer (FRP) reinforcement. A likely failure mode of such FRP-strengthened RC beams is the plate-end cover separation failure mode which involves debonding of the bonded FRP reinforcement and the cover concrete along the level of the steel tension reinforcement. Despite many existing studies on this failure mode, the accurate prediction of this failure mode using the finite element (FE) method has remained a great challenge. This paper presents a novel FE smeared-crack approach for accurate prediction of plate-end cover separation in which the radial stresses generated by the steel tension reinforcement are taken into account for the first time. The capability and validity of the proposed FE model are verified using existing experimental results.
To examine the real effects of typical inorganics on the emission behavior of PM10 during coal combustion and explore the interactions between the typical vaporized and refractory inorganics, Na-, Si-, and (Na+Si)-loaded coals prepared from the ash-removed PDS bituminous coal and ZD subbituminous coal were combusted in a high temperature drop-tube furnace (DTF) at 1500 °C in air. The produced inorganic PM10 and PM2.5 were collected and characterized. The experimentally measured PM emission results from the combustion of the (Na+Si)-loaded coals were compared with the calculated results that are the sum of PM emitted from the combustion of the Na- and Si-loaded coals. The calculated yields of PM0.3 of two studied coals are higher than the experimental ones, while the calculated yields of PM0.3-2.5 are lower. The experimental yield of PM0.3-2.5 is mainly enhanced by the sodium condensing heterogeneously on fine quartz particles, while the sodium would contribute to PM0.3 homogeneously, leading to the higher calculated result derived from the Na-loaded coal. Na is prevalent in only submicron particles for both the Na- and the (Na+Si)-loaded coals. The homogeneous partitioning ratio of Na is unaffected by the loading of quartz, but the heterogeneous partitioning ratio is affected by the quartz particles on which vaporized Na can condense into particles larger than 0.2 μm. Si presents similar distribution characteristics of trimodal for both the Si- and the (Na+Si)-loaded coal. The partitioning of Si in PM0.3 appears to be affected by Na due to the higher partitioning ratio of the (Na+Si)-loaded coal. The apparent catalytic effects of Na species on the combustion reactivity should beneficiate the local reducing atmosphere, and thereby promote the reduction of SiO2 to SiO, which is easily vaporized to contribute to PM0.3 for the (Na+Si)-loaded coal.
Extensive research has been conducted on the replacement of steel rebars with fibre-reinforced polymer rebars to eliminate the steel corrosion problem in conventional steel bar–reinforced concrete ...
