The influence of glycol,the main composition of the most frequently used aircraft dicer,on the freeze-thaw durability of high performance concrete(HPC)is investigated.Freeze-thaw durability of HPC is tested by accel...The influence of glycol,the main composition of the most frequently used aircraft dicer,on the freeze-thaw durability of high performance concrete(HPC)is investigated.Freeze-thaw durability of HPC is tested by accelerated freeze-thaw test.Four kinds of the solution,i.e.,tap water,3.5% NaCl solution,glycol solutions,and a LBR-A type commercial aircraft deicer are employed.Results show that freeze-thaw durability of HPC exposed to glycol solutions is closely related to the solution concentrations.The failure of HPC exposed to 3.5% glycol solution is similar to that of those exposed to 3.5% NaCl solution,i.e.,serious surface scaling.While the damage of HPC exposed to 12.5%—25% glycol solutions is postponed.Compared with glycol solution,the commercial aircraft deicer has much more negative effects on HPC freeze-thaw durability compared with 3.5% NaCl solution.In the presence of commercial aircraft deicer for HPC subjected to freeze-thaw cycles,the deterioration is mainly due to scaling and spalling.展开更多
The properties of two types of fly ash geopolymers made from class F fly ashes produced in wet bottom and dry bottom boilers were investigated in the present study. The source material used in the geopolymer concrete ...The properties of two types of fly ash geopolymers made from class F fly ashes produced in wet bottom and dry bottom boilers were investigated in the present study. The source material used in the geopolymer concrete was activated with sodium hydroxide and sodium silicate solution. The results revealed that the geopolymer produced with wet bottom boiler fly ash(CZ-FA)hardened quickly, and had higher early-age strength and lower shrinkage than the geopolymer produced with dry bottom boiler fly ash(SX-FA). The compressive strength of the two geopolymers made from CZ-FA and SX-FA was 45 MPa and 15 MPa respectively when cured at 60 ℃ and delayed for 14 d. However, after 90 days' delay, the compressive strength of both the samples is almost the same, up to 80 MPa. Nearly 20% volume shrinkage of the samples made from SX-FA was much higher than that made from CZ-FA, which was almost zero. XRD, SEM/EDS and FT-IR were used to analyze the main reason of the differences.展开更多
The purpose of this paper is to develop a prediction model of WGCLSM (waste LCD (liquid crystal display) glass controlled low strength materials) concrete, the relationship between UPV (ultrasonic pulse velocity...The purpose of this paper is to develop a prediction model of WGCLSM (waste LCD (liquid crystal display) glass controlled low strength materials) concrete, the relationship between UPV (ultrasonic pulse velocity) and compressive strength, UPV-strength model. The power function was used to perform the nonlinear-multivariate regression analysis of UPV with water-binder ratio (w/b), curing age (t) and waste glass content (G) in our previous study. Test results show that the compressive strength increases with UPV and approach to a linear relationship. Thus, the UPV-strength model was established by linear-multivariate regression analysis and the compressive strength evaluated by ultrasonic pulse velocity. The calculated results are in accordance with the laboratory measured data ultrasonic pulse velocity and compressive strength. In addition, the statistical analysis shows that the coefficient of determination R2 and the MAPE (mean absolute percentage error) were from 0.916 to 0.951 and 12.6% to 15.1% for the compressive strength, respectively. The proposed models are highly accurate in predicting the compressive and ultrasonic pulse velocity of WGCLSM concrete. However, with other ranges of mixture parameters, the predicted models must be further studied.展开更多
The most fundamental property of biomarkers is change.But changes are hard to maintain in plasma since it is strictly controlled by homeostatic mechanisms of the body.There is no homeostatic mechanism for urine.Beside...The most fundamental property of biomarkers is change.But changes are hard to maintain in plasma since it is strictly controlled by homeostatic mechanisms of the body.There is no homeostatic mechanism for urine.Besides,urine is partly a filtration of blood,and systematic information can be reflected in urine.We hypothesize that change of blood can be reflected in urine more sensitively.Here we introduce the interference into the blood by two anticoagulants heparin or argatroban.Plasma and urine proteins were profiled by LC-MS/MS and then validated by Western blot in totally six SD female rats before and after the drug treatments.In argatroban treated group,with exactly the same experimental procedure and the same cutoff value for both plasma and urine proteins,62 proteins changed in urine,only one of which changed in plasma.In heparin treated group,27 proteins changed in urine but only three other proteins changed in plasma.Both LC-MS/MS and Western blot analyses demonstrated drug-induced increases in transferrin and hemopexin levels in urine but not in plasma.Our data indicates that urine may serve as a source for more sensitive detection of protein biomarkers than plasma.展开更多
基金Supported by the National Basic Research Program of China("973"Program)(2009CB623203)the China Postdoctoral Science Foundation(20070421036)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2005216)the Research Foundation of Nanjing University of Aeronautics and Astronautics(NS2010015)~~
文摘The influence of glycol,the main composition of the most frequently used aircraft dicer,on the freeze-thaw durability of high performance concrete(HPC)is investigated.Freeze-thaw durability of HPC is tested by accelerated freeze-thaw test.Four kinds of the solution,i.e.,tap water,3.5% NaCl solution,glycol solutions,and a LBR-A type commercial aircraft deicer are employed.Results show that freeze-thaw durability of HPC exposed to glycol solutions is closely related to the solution concentrations.The failure of HPC exposed to 3.5% glycol solution is similar to that of those exposed to 3.5% NaCl solution,i.e.,serious surface scaling.While the damage of HPC exposed to 12.5%—25% glycol solutions is postponed.Compared with glycol solution,the commercial aircraft deicer has much more negative effects on HPC freeze-thaw durability compared with 3.5% NaCl solution.In the presence of commercial aircraft deicer for HPC subjected to freeze-thaw cycles,the deterioration is mainly due to scaling and spalling.
文摘The properties of two types of fly ash geopolymers made from class F fly ashes produced in wet bottom and dry bottom boilers were investigated in the present study. The source material used in the geopolymer concrete was activated with sodium hydroxide and sodium silicate solution. The results revealed that the geopolymer produced with wet bottom boiler fly ash(CZ-FA)hardened quickly, and had higher early-age strength and lower shrinkage than the geopolymer produced with dry bottom boiler fly ash(SX-FA). The compressive strength of the two geopolymers made from CZ-FA and SX-FA was 45 MPa and 15 MPa respectively when cured at 60 ℃ and delayed for 14 d. However, after 90 days' delay, the compressive strength of both the samples is almost the same, up to 80 MPa. Nearly 20% volume shrinkage of the samples made from SX-FA was much higher than that made from CZ-FA, which was almost zero. XRD, SEM/EDS and FT-IR were used to analyze the main reason of the differences.
文摘The purpose of this paper is to develop a prediction model of WGCLSM (waste LCD (liquid crystal display) glass controlled low strength materials) concrete, the relationship between UPV (ultrasonic pulse velocity) and compressive strength, UPV-strength model. The power function was used to perform the nonlinear-multivariate regression analysis of UPV with water-binder ratio (w/b), curing age (t) and waste glass content (G) in our previous study. Test results show that the compressive strength increases with UPV and approach to a linear relationship. Thus, the UPV-strength model was established by linear-multivariate regression analysis and the compressive strength evaluated by ultrasonic pulse velocity. The calculated results are in accordance with the laboratory measured data ultrasonic pulse velocity and compressive strength. In addition, the statistical analysis shows that the coefficient of determination R2 and the MAPE (mean absolute percentage error) were from 0.916 to 0.951 and 12.6% to 15.1% for the compressive strength, respectively. The proposed models are highly accurate in predicting the compressive and ultrasonic pulse velocity of WGCLSM concrete. However, with other ranges of mixture parameters, the predicted models must be further studied.
基金supported by the National Basic Research Program of China (2012CB517606,2013CB530805)Expertise-Introduction Project for Disciplinary Innovation of Universities (B08007)+1 种基金National Natural Science Foundation of China (31200614)Beijing Natural Science Foundation (5132028)
文摘The most fundamental property of biomarkers is change.But changes are hard to maintain in plasma since it is strictly controlled by homeostatic mechanisms of the body.There is no homeostatic mechanism for urine.Besides,urine is partly a filtration of blood,and systematic information can be reflected in urine.We hypothesize that change of blood can be reflected in urine more sensitively.Here we introduce the interference into the blood by two anticoagulants heparin or argatroban.Plasma and urine proteins were profiled by LC-MS/MS and then validated by Western blot in totally six SD female rats before and after the drug treatments.In argatroban treated group,with exactly the same experimental procedure and the same cutoff value for both plasma and urine proteins,62 proteins changed in urine,only one of which changed in plasma.In heparin treated group,27 proteins changed in urine but only three other proteins changed in plasma.Both LC-MS/MS and Western blot analyses demonstrated drug-induced increases in transferrin and hemopexin levels in urine but not in plasma.Our data indicates that urine may serve as a source for more sensitive detection of protein biomarkers than plasma.