The synergistic effects of area ratio and microstructure on the galvanic corrosion of A508/309 L/308 L dissimilar metals weld(DMW)are studied by a multi-analytical approach.It was demonstrated that decreasing the anod...The synergistic effects of area ratio and microstructure on the galvanic corrosion of A508/309 L/308 L dissimilar metals weld(DMW)are studied by a multi-analytical approach.It was demonstrated that decreasing the anode/cathode surface area ratio obviously enhances the corrosion rate of A508,both locally and globally.Deeper analyses of the AFM results enabled quantitative comparison of the corrosion behaviour of the different surface constituents.It was revealed that in the galvanic interaction of the DMW,the grain refined region corrodes most,followed by the partial grain refined region and base metal matrix of the A508,respectively.The electrochemical localization index(LI)estimation method and AFM analysis both confirmed the presence of a mixed(localized and uniform)corrosion phenomenon occurring on the surface of the A508 anode metal in the galvanic interaction of the dissimilar metals.Finally,the degree of synergism equation was utilized to describe the synergistic effects of anode/cathode area ratio and the microstructure of the samples on the galvanic corrosion of LAS A508/309 L/308 L SS DMW.展开更多
The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempte...The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate （SGR） and three important environmental factors （temperature, salinity, and pH） using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant （P〈0.05）, and they were equally important in impacting T. subcordiformis specific growth; the linear effect of pH was not significant （P〉0.05）; the interactive effect of temperature and pH was significant （P〈0.05）, whereas the temperature ~ salinity and salinity x pH interactions were not significant （P〉0.05）; all of the quadratic effects of the three factors were significant （P〈0.05）. A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25~C/35 of salinity/pH 7.9 was obtained, at which the maximum specific growth rate （0.65） was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.展开更多
Cold stripping is the most common process for crude oil sweetening in oilfields particularly at offshore installations because of its low price and relatively easy operating conditions in comparison with other sweeten...Cold stripping is the most common process for crude oil sweetening in oilfields particularly at offshore installations because of its low price and relatively easy operating conditions in comparison with other sweetening processes. In this paper the cold stripping process in tray column has been modeled mathematically in static and dynamic modes, and solved with the MATLAB software. This process has been used in the existing treatment facilities of an offshore oil production complex for verifying the model results. With the help of HYSYS software the effective parameters on the process have been discussed and the optimized conditions finalized after some plant modifications for improving the performance of stripper columns have been proposed.展开更多
[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activi...[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.展开更多
This paper reports the experimental investigation of the agronomic performance of okra under various quantities of both sawdust and trash mulches. The location of the field was the research farmland of the Federal Pol...This paper reports the experimental investigation of the agronomic performance of okra under various quantities of both sawdust and trash mulches. The location of the field was the research farmland of the Federal Polytechnic Ado Ekiti Nigeria;Lat 6?N and Long 16?E. The experimental design used was complete randomized design with 6 treatments on both specimens. The experiments were repeated the following year on the same plot but with transposed plot allocation. Soil moisture loss from uncovered plot was with the highest value dropping to less than 2 per cent. It was followed by that of trash plot and the lowest loss was on sawdust mulched plot. The number of leave formed by okra on sawdust, trash and no mulch plots was 43, 36 and 27 respectively while maximum girth diameter was 37 mm in both trash and sawdust covered plots but okra plant on control plot attained only 26 mm diameter. Fruit yield were almost similar to trash and sawdust mulched okra having 7.5 and 7.6 Tonnes/Ha respectively while control plot recorded 5.2 Tonnes/Ha. The ash content of dry matter of sawdust, trash and no mulched plants was 0.25, 0.20 and 0.17 kg respectively. It was concluded that sawdust could perform as much as the traditional trash materials commonly used in Southwestern Nigeria. Also, sawdust was a good material for conserving soil moisture.展开更多
Usually,the response after a disastrous event requires decision-makers in emergency operative rooms to quickly outline and understand the current post-event situation,for planning and defining strategies for a context...Usually,the response after a disastrous event requires decision-makers in emergency operative rooms to quickly outline and understand the current post-event situation,for planning and defining strategies for a contextualized response.Moreover,in many cases,disastrous events affect cross-border territories and/or involve multiple orga-nizations in responding to the demand generated by the event.These cases require a harmonized and coordinated response by all the institutions/subjects involved in emergency management.To address this challenge,this pa-per proposes the e-Atlas(emergency atlas)tool for showing and sharing information that embraces a response management perspective to explicitly support decision-makers in managing the criticalities of a post-earthquake situation.The e-Atlas has been designed and tested to:i)acquire sensible information for allowing decision-makers to understand in almost real-time the post-earthquake situational picture,and ii)share the representation of the situational picture among different users,allowing each of them to use it according to its specific require-ments.Applications of the tool are illustrated,to show how it is used in a transborder context in the North-East area of Italy.展开更多
This paper discusses a visco-elastoplastic constitutive model to analyze the creep deformability of asphalt concretes at high service temperatures, finalized to improve the interpretation of permanent deformation phen...This paper discusses a visco-elastoplastic constitutive model to analyze the creep deformability of asphalt concretes at high service temperatures, finalized to improve the interpretation of permanent deformation phenomenon and performance design of road pavements. A three dimensional constitutive visco-elastoplastic model is introduced, in tensor as well as in numerical form. The associated uniaxial model is used to arrange a plastic element in series with the viscoelastic component. The latter is defined by an elastic spring placed in parallel with three Maxwell elements. Three different hardening laws, namely isotropic, kinematic and mixed hardening, are included in the constitutive model to compare the creep deformability. The proposed constitutive model has been calibrated and validated on the basis of uniaxial creep-recovery test results at 40℃. This is performed with a high performance hot mix asphalt concrete （HP-HMA） at different stresses and loading times. Depending on the hardening law considered, permanent deformation data predicted by the proposed model results are reasonably consistent with the experimental creep-recovery data. A rational constitutive model that is physically congruent with the creep phenomenon of asphalt concretes was developed and calibrated to achieve a deeper understanding of the stress-strain response of such materials. The fundamental relevance of an appropriate plastic response modeling, in the study of the creep behavior of asphalt concretes for highway and road pavements.展开更多
基金the National Natural Science Foundation of China(No.51771211)Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-JSC012)the Key Program of the Chinese Academy of Sciences(ZDRW-CN-2017-1)。
文摘The synergistic effects of area ratio and microstructure on the galvanic corrosion of A508/309 L/308 L dissimilar metals weld(DMW)are studied by a multi-analytical approach.It was demonstrated that decreasing the anode/cathode surface area ratio obviously enhances the corrosion rate of A508,both locally and globally.Deeper analyses of the AFM results enabled quantitative comparison of the corrosion behaviour of the different surface constituents.It was revealed that in the galvanic interaction of the DMW,the grain refined region corrodes most,followed by the partial grain refined region and base metal matrix of the A508,respectively.The electrochemical localization index(LI)estimation method and AFM analysis both confirmed the presence of a mixed(localized and uniform)corrosion phenomenon occurring on the surface of the A508 anode metal in the galvanic interaction of the dissimilar metals.Finally,the degree of synergism equation was utilized to describe the synergistic effects of anode/cathode area ratio and the microstructure of the samples on the galvanic corrosion of LAS A508/309 L/308 L SS DMW.
基金Supported by the Guangdong Province Science and Technology Project(No.2010B020201014)the Guangdong Province South China Sea Invertebrates Healthy Culture Engineering Technology Research Center(No.GCZX-A0909)+2 种基金the Guangdong Province Ocean and Fisheries Science and Technology Extension Project(No.20120980)the Guangdong Province Industry-University-Science Partnership Project(No.20110908)the Sci&Tech Plan of Huaiyin Normal University(No.WH0031)
文摘The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate （SGR） and three important environmental factors （temperature, salinity, and pH） using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant （P〈0.05）, and they were equally important in impacting T. subcordiformis specific growth; the linear effect of pH was not significant （P〉0.05）; the interactive effect of temperature and pH was significant （P〈0.05）, whereas the temperature ~ salinity and salinity x pH interactions were not significant （P〉0.05）; all of the quadratic effects of the three factors were significant （P〈0.05）. A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25~C/35 of salinity/pH 7.9 was obtained, at which the maximum specific growth rate （0.65） was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.
文摘Cold stripping is the most common process for crude oil sweetening in oilfields particularly at offshore installations because of its low price and relatively easy operating conditions in comparison with other sweetening processes. In this paper the cold stripping process in tray column has been modeled mathematically in static and dynamic modes, and solved with the MATLAB software. This process has been used in the existing treatment facilities of an offshore oil production complex for verifying the model results. With the help of HYSYS software the effective parameters on the process have been discussed and the optimized conditions finalized after some plant modifications for improving the performance of stripper columns have been proposed.
基金Independent Application Project of Agricultural and Social Development Scientific Research in Hangzhou(20191203B31).
文摘[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.
文摘This paper reports the experimental investigation of the agronomic performance of okra under various quantities of both sawdust and trash mulches. The location of the field was the research farmland of the Federal Polytechnic Ado Ekiti Nigeria;Lat 6?N and Long 16?E. The experimental design used was complete randomized design with 6 treatments on both specimens. The experiments were repeated the following year on the same plot but with transposed plot allocation. Soil moisture loss from uncovered plot was with the highest value dropping to less than 2 per cent. It was followed by that of trash plot and the lowest loss was on sawdust mulched plot. The number of leave formed by okra on sawdust, trash and no mulch plots was 43, 36 and 27 respectively while maximum girth diameter was 37 mm in both trash and sawdust covered plots but okra plant on control plot attained only 26 mm diameter. Fruit yield were almost similar to trash and sawdust mulched okra having 7.5 and 7.6 Tonnes/Ha respectively while control plot recorded 5.2 Tonnes/Ha. The ash content of dry matter of sawdust, trash and no mulched plants was 0.25, 0.20 and 0.17 kg respectively. It was concluded that sawdust could perform as much as the traditional trash materials commonly used in Southwestern Nigeria. Also, sawdust was a good material for conserving soil moisture.
基金The ARMONIAtlas was developed during the Interreg V-A Italy-Austria 2014-2020 ARMONIA project(No.ITAT3016),financed by the European Regional Development Fund.
文摘Usually,the response after a disastrous event requires decision-makers in emergency operative rooms to quickly outline and understand the current post-event situation,for planning and defining strategies for a contextualized response.Moreover,in many cases,disastrous events affect cross-border territories and/or involve multiple orga-nizations in responding to the demand generated by the event.These cases require a harmonized and coordinated response by all the institutions/subjects involved in emergency management.To address this challenge,this pa-per proposes the e-Atlas(emergency atlas)tool for showing and sharing information that embraces a response management perspective to explicitly support decision-makers in managing the criticalities of a post-earthquake situation.The e-Atlas has been designed and tested to:i)acquire sensible information for allowing decision-makers to understand in almost real-time the post-earthquake situational picture,and ii)share the representation of the situational picture among different users,allowing each of them to use it according to its specific require-ments.Applications of the tool are illustrated,to show how it is used in a transborder context in the North-East area of Italy.
文摘This paper discusses a visco-elastoplastic constitutive model to analyze the creep deformability of asphalt concretes at high service temperatures, finalized to improve the interpretation of permanent deformation phenomenon and performance design of road pavements. A three dimensional constitutive visco-elastoplastic model is introduced, in tensor as well as in numerical form. The associated uniaxial model is used to arrange a plastic element in series with the viscoelastic component. The latter is defined by an elastic spring placed in parallel with three Maxwell elements. Three different hardening laws, namely isotropic, kinematic and mixed hardening, are included in the constitutive model to compare the creep deformability. The proposed constitutive model has been calibrated and validated on the basis of uniaxial creep-recovery test results at 40℃. This is performed with a high performance hot mix asphalt concrete （HP-HMA） at different stresses and loading times. Depending on the hardening law considered, permanent deformation data predicted by the proposed model results are reasonably consistent with the experimental creep-recovery data. A rational constitutive model that is physically congruent with the creep phenomenon of asphalt concretes was developed and calibrated to achieve a deeper understanding of the stress-strain response of such materials. The fundamental relevance of an appropriate plastic response modeling, in the study of the creep behavior of asphalt concretes for highway and road pavements.
