We investigated the effects of ferro-vanadium slag(FVS)as a supplemental cementing material which can dissolve a large amount of active aluminum phases without excessive pretreatment or excitation to enhance the inner...We investigated the effects of ferro-vanadium slag(FVS)as a supplemental cementing material which can dissolve a large amount of active aluminum phases without excessive pretreatment or excitation to enhance the inner chloride solidified rate(CSR)of cement-based materials.Cement-FVS pastes with 0-30%content of FVS was designed,and the CSR was examined.Hydrates at different curing ages were studied by X-ray diffraction(XRD)and thermo-gravimetric analysis(TGA);hydration heat and^(29)Si nuclear magnetic resonance(^(29)Si-NMR)were tested to analyze the hydration degree of the system;mechanical properties in cement-FVS system were evaluated by compressive strength test,pore structure and the fractal regression.Results revealed that the incorporation of FVS could greatly promote the CSR of cement-FVS system.Compared with the control groups,30%dosage of FVS could increase the CSR by 69%at 3 d,47%at 7d,36%at 28 d and 34%at 60 d.It was demonstrated that the incorporation of FVS could enhance the chemical solidifying ability of chloride,and the main reason was the promoted generation of Kuzel’s salt and the Friedel’s salt in hydrate products,and the enhanced chloride migration resistance capacity by increasing the volume of gel pores in the cement-FVS system.Considering the influence of FVS on strength performance,this paper suggested that the suitable dosage of FVS as a supplemental cementing material was around 10%.The study in this paper might provide one efficient path to promote the chloride solidifying capacity of cement-based material and meanwhile the comprehensive utilization of FVS.展开更多
<strong>Background:</strong> Previous studies have shown that chloride liberal fluids may be associated with worse renal outcomes. Deterioration of kidney function during hyperchloremia/chloride overload i...<strong>Background:</strong> Previous studies have shown that chloride liberal fluids may be associated with worse renal outcomes. Deterioration of kidney function during hyperchloremia/chloride overload is believed to be induced by disturbances in renal perfusion, but exact mechanisms of chloride nephrotoxicity are unclear. The purpose of this randomized, crossover study was to investigate the effect of chloride loading on renal plasma flow (RPF), filtration fraction (FF) and glomerular filtration rate (GFR) in order to elucidate potential nephrotoxic mechanisms of chloride infusion. <strong>Methods:</strong> Fifteen healthy males were investigated twice after treatment with 2L isotonic saline and plasma-lyte with a wash-out period of at least 10 days. Within 15 mins after completion of infusion, the kidney parameters (RPF, FF and GFR) were estimated by Technetium-99m diethylenetriamine penta-acetic acid (99-mTc-DTPA) renography. <strong>Results:</strong> 99-mTc-DTPA renography showed reduction in both mean GFR (114 ± 13 ml/min vs.119 ± 12 ml/min, <i>p</i> = 0.04) and RPF (977 ± 272 ml/min vs. 1066 ± 197 ml/min, p = 0.19) and increasing FF (12% ± 2% vs. 11% ± 2%, <i>p</i> = 0.19) after 0.9% saline comparing to Plasmalyte, but only GFR reduction was statistically significant. Reduction in GFR and RPF and increasing in FF after 0.9% saline was observed in 10 subjects while in 5 others the reverse trend was shown. There were no statistically significant differences between mean systolic and diastolic blood pressure (BP) before and after each infusion except baseline diastolic BP. Weight changes (Δ weight) were similar after each infusion. <strong>Conclusions:</strong> We have demonstrated that high chloride infusion can affect kidney function in healthy subjects and seems to lead to impairment in both RPF and GFR.展开更多
Al-4.5wt.%Cu alloy has been directionally solidified at constant and abruptly changing withdrawal rates, respectively. The effects of the withdrawal rate on solidification microstructure, primary dendrite arm spacing(...Al-4.5wt.%Cu alloy has been directionally solidified at constant and abruptly changing withdrawal rates, respectively. The effects of the withdrawal rate on solidification microstructure, primary dendrite arm spacing(PDAS) and liquid solute distribution in front of the solid-liquid interface were investigated. The experimental results for the PDAS at a constant withdrawal rate agree well with the values calculated by the Hunt, Trivedi and Hunt-Lu models. At an abrupt change in the withdrawal rate, the maximum to minimum ratio of the PDAS at a given solidification parameter, i.e. λ1max/λ1min, is more than 2, and the PDAS values are remarkably history-dependent. Further, the liquid-solute distribution curve based on theoretical calculation shows that the larger the initial withdrawal rate is, the smaller the minimum of liquid solute concentration in front of the solid-liquid interface is after the abrupt change in withdrawal rate.展开更多
A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly p...A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution p H value, stirring rate, concentration of Ca Cl2 aqueous solution, liquid-to-solid(L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy(SEM) and X-ray diffraction(XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution p H value of 1, a stirring rate of 500 r·min–1, a Ca Cl2 aqueous solution concentration of 400 g·L–1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.展开更多
Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete.A multi-cell sensor system that included a refe...Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete.A multi-cell sensor system that included a reference electrode,a chloride content sensor,a macrocell current unit and an electrical resistance measurement unit was developed.This system provided the following important electrochemical data in the cover-zone concrete on site:open circuit potential,macrocell current from anodes to cathode,chloride profile,concrete resistance and corrosion rate of built-in anodes.The experimental results show that the macrocell current increases when the chloride content in concrete is higher.Thus,monitoring the chloride content is a good method for monitoring the corrosion state.The chloride ion content and cover depth are the key factors that affect the electrical resistance of concrete.Without considering the temperature and time,a simplified model of the instantaneous corrosion rate of steel rebar in a concrete structure based on the measured chloride contents and concrete resistance was proposed.The test results further prove the reliability of this simplified predicting model.展开更多
This investigation deals with the free radical polymerization both of （2-methacryloyloxy-ethyl） trimethyl ammonium chloride （QACEMA） and of diallyldimethyl ammoniumcbloride （DADMAC） in inverse emulsion. The infl...This investigation deals with the free radical polymerization both of （2-methacryloyloxy-ethyl） trimethyl ammonium chloride （QACEMA） and of diallyldimethyl ammoniumcbloride （DADMAC） in inverse emulsion. The influences of some factors, such as theconcentration of monomers, initiator and emulsifier are discussed. The polymerization rateequations of above two monomers can be written as follows:R<sub>p</sub>= k[M]<sup>1.21</sup> [I]<sup>0.82</sup> [E]<sup>0.57</sup> （for QACEMA）R<sub>p</sub>= k’[M]<sup>1.34</sup> [I]<sup>0.90</sup>[E]<sup>0.62</sup>（for DADMAC）展开更多
Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate o...Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate of the composite coatings increases with the increasing concentrations of phosphoric and ferric chloride, and reaches the maximum value when phosphoric concentration is 40% and ferric chloride concentration is 20% (mass fraction, the same below if not mentioned). Anode polarization curves of the composite coatings show that anode polarization current density of the composite coatings heat-treated at 200 ℃ or 500 ℃ is lower than that of other coatings heat-treated at 300 ℃ or 400 ℃, which displays that the composite coatings heat-treated at 200 ℃ or 500 ℃ have better corrosion resistance. Besides, corrosion resistance of the composite coating heat-treated at 500 ℃ is better than that as deposited and RE-Ni-W-P-SiC composite coating heat-treated at 400 ℃, and is also better than that of 316L stainless steel.展开更多
The purposes of this study are to prepare the generic extended release tablet of potassiumchloride(PC) 600 mg and to compare the absorption of potassium ion from the experimen-tal tablets to that of Kaleorid? LP 600 m...The purposes of this study are to prepare the generic extended release tablet of potassiumchloride(PC) 600 mg and to compare the absorption of potassium ion from the experimen-tal tablets to that of Kaleorid? LP 600 mg(Leo Pharmaceutical Products, Denmark). Car-nauba wax was used as retardant in the matrix core tablets. The core tablets were coatedwith blends of ethyl cellulose(EC) and hydroxypropyl methyl cellulose(HPMC) to modulatethe drug release. Results of a selective two-level, three-factor experiment design revealedthat a blend of 41.75% of EC and 58.25% of HPMC at 4.5% weight gained could produce thecoated tablets having dissolution profiles similar to those of Kaleorid?. A two-treatment,two-period, two-sequence crossover bioequivalence study was carried out on 24 healthyvolunteers to compare the absorption of potassium ion from experimental tablets to thatfrom Kaleorid?. The potassium ion in the urine was measured by a selective electrode of theADVIA 1650 system(Bayer) and used to calculate cumulative urinary excretion and urinaryexcretion rate. Results of 90 percent confidence interval analysis showed that the limits fornatural log-transformed cumulative urinary potassium excretion(Ln Ae 0-24) of test productwere in the range of 3.73–3.79 mEq, corresponding to 99.08%–100.92% of Kaleorid ?, respec-tively, and the limits for natural log-transformed maximal potassium excretion rate( R max) oftest product were in the range of 1.72–1.82 mEq/h, corresponding to 97.34%–102.66% of refer-ence product, respectively. Both of them fell within the bioequivalence interval(80%–125%)of reference product, proving that experimental product is bioequivalent to Kaleorid ?.展开更多
基金National Key Research and Development Program of China(No.2019YFC1907101-03)Major Technical Innovation Project in Hubei Province of China(Nos.2021BAA060,2020BCA077)。
文摘We investigated the effects of ferro-vanadium slag(FVS)as a supplemental cementing material which can dissolve a large amount of active aluminum phases without excessive pretreatment or excitation to enhance the inner chloride solidified rate(CSR)of cement-based materials.Cement-FVS pastes with 0-30%content of FVS was designed,and the CSR was examined.Hydrates at different curing ages were studied by X-ray diffraction(XRD)and thermo-gravimetric analysis(TGA);hydration heat and^(29)Si nuclear magnetic resonance(^(29)Si-NMR)were tested to analyze the hydration degree of the system;mechanical properties in cement-FVS system were evaluated by compressive strength test,pore structure and the fractal regression.Results revealed that the incorporation of FVS could greatly promote the CSR of cement-FVS system.Compared with the control groups,30%dosage of FVS could increase the CSR by 69%at 3 d,47%at 7d,36%at 28 d and 34%at 60 d.It was demonstrated that the incorporation of FVS could enhance the chemical solidifying ability of chloride,and the main reason was the promoted generation of Kuzel’s salt and the Friedel’s salt in hydrate products,and the enhanced chloride migration resistance capacity by increasing the volume of gel pores in the cement-FVS system.Considering the influence of FVS on strength performance,this paper suggested that the suitable dosage of FVS as a supplemental cementing material was around 10%.The study in this paper might provide one efficient path to promote the chloride solidifying capacity of cement-based material and meanwhile the comprehensive utilization of FVS.
文摘<strong>Background:</strong> Previous studies have shown that chloride liberal fluids may be associated with worse renal outcomes. Deterioration of kidney function during hyperchloremia/chloride overload is believed to be induced by disturbances in renal perfusion, but exact mechanisms of chloride nephrotoxicity are unclear. The purpose of this randomized, crossover study was to investigate the effect of chloride loading on renal plasma flow (RPF), filtration fraction (FF) and glomerular filtration rate (GFR) in order to elucidate potential nephrotoxic mechanisms of chloride infusion. <strong>Methods:</strong> Fifteen healthy males were investigated twice after treatment with 2L isotonic saline and plasma-lyte with a wash-out period of at least 10 days. Within 15 mins after completion of infusion, the kidney parameters (RPF, FF and GFR) were estimated by Technetium-99m diethylenetriamine penta-acetic acid (99-mTc-DTPA) renography. <strong>Results:</strong> 99-mTc-DTPA renography showed reduction in both mean GFR (114 ± 13 ml/min vs.119 ± 12 ml/min, <i>p</i> = 0.04) and RPF (977 ± 272 ml/min vs. 1066 ± 197 ml/min, p = 0.19) and increasing FF (12% ± 2% vs. 11% ± 2%, <i>p</i> = 0.19) after 0.9% saline comparing to Plasmalyte, but only GFR reduction was statistically significant. Reduction in GFR and RPF and increasing in FF after 0.9% saline was observed in 10 subjects while in 5 others the reverse trend was shown. There were no statistically significant differences between mean systolic and diastolic blood pressure (BP) before and after each infusion except baseline diastolic BP. Weight changes (Δ weight) were similar after each infusion. <strong>Conclusions:</strong> We have demonstrated that high chloride infusion can affect kidney function in healthy subjects and seems to lead to impairment in both RPF and GFR.
基金financially supported by the National Natural Science Foundation of China(No.50971101)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20136102110014)
文摘Al-4.5wt.%Cu alloy has been directionally solidified at constant and abruptly changing withdrawal rates, respectively. The effects of the withdrawal rate on solidification microstructure, primary dendrite arm spacing(PDAS) and liquid solute distribution in front of the solid-liquid interface were investigated. The experimental results for the PDAS at a constant withdrawal rate agree well with the values calculated by the Hunt, Trivedi and Hunt-Lu models. At an abrupt change in the withdrawal rate, the maximum to minimum ratio of the PDAS at a given solidification parameter, i.e. λ1max/λ1min, is more than 2, and the PDAS values are remarkably history-dependent. Further, the liquid-solute distribution curve based on theoretical calculation shows that the larger the initial withdrawal rate is, the smaller the minimum of liquid solute concentration in front of the solid-liquid interface is after the abrupt change in withdrawal rate.
基金the Research Fund for the Doctoral Program of Higher Education, China (No. 20110042120014)the Project Supported by National Natural Science Foundation of China (Nos. 51204036 and 51234009)the National Basic Research of Program of China (No. 2014CB643405)
文摘A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution p H value, stirring rate, concentration of Ca Cl2 aqueous solution, liquid-to-solid(L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy(SEM) and X-ray diffraction(XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution p H value of 1, a stirring rate of 500 r·min–1, a Ca Cl2 aqueous solution concentration of 400 g·L–1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.
基金Project(200632800003-11) supported by Western Communications Construction Scientific and Technological Project in China
文摘Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete.A multi-cell sensor system that included a reference electrode,a chloride content sensor,a macrocell current unit and an electrical resistance measurement unit was developed.This system provided the following important electrochemical data in the cover-zone concrete on site:open circuit potential,macrocell current from anodes to cathode,chloride profile,concrete resistance and corrosion rate of built-in anodes.The experimental results show that the macrocell current increases when the chloride content in concrete is higher.Thus,monitoring the chloride content is a good method for monitoring the corrosion state.The chloride ion content and cover depth are the key factors that affect the electrical resistance of concrete.Without considering the temperature and time,a simplified model of the instantaneous corrosion rate of steel rebar in a concrete structure based on the measured chloride contents and concrete resistance was proposed.The test results further prove the reliability of this simplified predicting model.
基金This project is supported by Tianjin Science Foundation for Youths.
文摘This investigation deals with the free radical polymerization both of （2-methacryloyloxy-ethyl） trimethyl ammonium chloride （QACEMA） and of diallyldimethyl ammoniumcbloride （DADMAC） in inverse emulsion. The influences of some factors, such as theconcentration of monomers, initiator and emulsifier are discussed. The polymerization rateequations of above two monomers can be written as follows:R<sub>p</sub>= k[M]<sup>1.21</sup> [I]<sup>0.82</sup> [E]<sup>0.57</sup> （for QACEMA）R<sub>p</sub>= k’[M]<sup>1.34</sup> [I]<sup>0.90</sup>[E]<sup>0.62</sup>（for DADMAC）
基金Project([2002]24) supported by the National Development and Reform Commission of China
文摘Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate of the composite coatings increases with the increasing concentrations of phosphoric and ferric chloride, and reaches the maximum value when phosphoric concentration is 40% and ferric chloride concentration is 20% (mass fraction, the same below if not mentioned). Anode polarization curves of the composite coatings show that anode polarization current density of the composite coatings heat-treated at 200 ℃ or 500 ℃ is lower than that of other coatings heat-treated at 300 ℃ or 400 ℃, which displays that the composite coatings heat-treated at 200 ℃ or 500 ℃ have better corrosion resistance. Besides, corrosion resistance of the composite coating heat-treated at 500 ℃ is better than that as deposited and RE-Ni-W-P-SiC composite coating heat-treated at 400 ℃, and is also better than that of 316L stainless steel.
基金Financial support for bioequivalence study from The Department of Science and Technology (grant number 209/HDSKHCN) of Ho chi Minh city (DOST)
文摘The purposes of this study are to prepare the generic extended release tablet of potassiumchloride(PC) 600 mg and to compare the absorption of potassium ion from the experimen-tal tablets to that of Kaleorid? LP 600 mg(Leo Pharmaceutical Products, Denmark). Car-nauba wax was used as retardant in the matrix core tablets. The core tablets were coatedwith blends of ethyl cellulose(EC) and hydroxypropyl methyl cellulose(HPMC) to modulatethe drug release. Results of a selective two-level, three-factor experiment design revealedthat a blend of 41.75% of EC and 58.25% of HPMC at 4.5% weight gained could produce thecoated tablets having dissolution profiles similar to those of Kaleorid?. A two-treatment,two-period, two-sequence crossover bioequivalence study was carried out on 24 healthyvolunteers to compare the absorption of potassium ion from experimental tablets to thatfrom Kaleorid?. The potassium ion in the urine was measured by a selective electrode of theADVIA 1650 system(Bayer) and used to calculate cumulative urinary excretion and urinaryexcretion rate. Results of 90 percent confidence interval analysis showed that the limits fornatural log-transformed cumulative urinary potassium excretion(Ln Ae 0-24) of test productwere in the range of 3.73–3.79 mEq, corresponding to 99.08%–100.92% of Kaleorid ?, respec-tively, and the limits for natural log-transformed maximal potassium excretion rate( R max) oftest product were in the range of 1.72–1.82 mEq/h, corresponding to 97.34%–102.66% of refer-ence product, respectively. Both of them fell within the bioequivalence interval(80%–125%)of reference product, proving that experimental product is bioequivalent to Kaleorid ?.
