In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralizatio...In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralization curve, Al（OH）3 precipitation efficiency and induction period of bayerite were investigated. The results indicate that the neutralization curve of the artificial chromate alkali solutions shows three distinct regions and its induction period is longer than that of pure sodium aluminate solutions at the same aluminum concentration. And the decreased temperature and volume fraction of CO2 enhance the particle size of bayerite β-Al（OH）3. Bayerite composed of agglomerates of rods and cone frustums was obtained from alkali metal chromate solutions with 28.5% CO2（volume fraction） at temperatures ranging from 50 °C to 70 °C. Coarse bayerite with particle size（d50） from 24.2 μm to 29.3 μm extremely has few impurities, which is suitable for comprehensive utilization.展开更多
Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily lea...Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily leached by water, and the formed calcium carbonate can be easily wrapped on the surface of unreacted steelmaking slag particles. Thus, further increase in the carbonation reaction rate can be prevented. Enhanced carbon dioxide mineral sequestration with steel- making slag in dilute alkali solution was analysed in this study through experiments and process evaluation. Operating conditions, namely alkali concentration, reaction temperature and time, and liquid-to-solid ratio, were initially investigated. Then, the material and energy balance of the entire process was calculated, and the net carbon dioxide sequestration efficiency at different reaction times was evaluated. Results showed that dilute alkali solution participated in slowing down the leaching of active calcium in the steelmaking slag and in significantly improving carbonation conversion rate. The highest carbonation conversion rate of approximately 50% can be obtained at the optimal conditions of 20 g/L alkali concentration, 2 mL/L liquid-to-solid ratio, and 70 ℃ reaction temperature. Carbonation reaction time significantly influences the net carbon dioxide sequestration efficiency. According to calculation, carbon dioxide emission of 52.6 kg/t- slag was avoided at a relatively long time of 120 min.展开更多
In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concen...In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.展开更多
Filtering materials are chosen according to the mechanism of blood filtration and mathematics model, then the material is treated with amine and alkali solution. There is cooperation and synergism between alkali and a...Filtering materials are chosen according to the mechanism of blood filtration and mathematics model, then the material is treated with amine and alkali solution. There is cooperation and synergism between alkali and amine, and the actions are realized in three stages. After modification the material treated has accessibility groups NH 2 , and slits appeared in the surface of fiber, so the wettability of materials is improved distinctly; the diameter and aperture of fiber have no changes basically.展开更多
In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpr...In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.展开更多
The performance of roller compacted concrete(RCC)was greatly influenced by variations in material proportion,optimum moisture content,density of mixes and methodology adopted making it different from conventional conc...The performance of roller compacted concrete(RCC)was greatly influenced by variations in material proportion,optimum moisture content,density of mixes and methodology adopted making it different from conventional concrete mixes.Even though RCC has gained popularity,the complex phenomenon involved in developing the RCC mixes limits it from large-scale applications.In this study,reclaimed asphalt pavement(RAP)incorporated roller-compacted geopolymer concrete(RGC)mixes were developed herein with different compaction techniques such as vibratory hammer(VH),modified proctor(MP),vibration table(VT)and compression machine(CM)are studied and compared with control mixes of natural aggregates.Initially,the effect of alkali solutions such as sodium hydroxide(SH)and sodium silicate(SS)on the physical properties.During,the second phase mechanical properties such as dry density,compressive,flexural and split-tensile strength,modulus of elasticity and microstructure properties will be investigated.The test results revealed that compaction efforts were greatly influenced by the alkali solution.Furthermore,the poor bond characteristics between RAP and the binder matrix had a significant effect on strength properties.Also,the various compaction techniques affected the mechanical properties of mixes developed herein.In Comparison with various compaction efforts,VH and MP produced comparable results,whereas the VT method underestimated and overestimated the various strength properties.Although,the CM method reports comparable results but difficult to maintain consistency in strength aspects.Therefore,optimization of various parameters influencing the concrete properties needs to be achieved for field density.展开更多
BACKGROUND: Percutaneous ethanol injection has been widely used as a non-surgical therapy for liver cancer, but it has some shortcomings such as local diffusion and une- qual permeation. This study was designed to obs...BACKGROUND: Percutaneous ethanol injection has been widely used as a non-surgical therapy for liver cancer, but it has some shortcomings such as local diffusion and une- qual permeation. This study was designed to observe the volume, controllability and completeness of necrosis after injection of low concentration sodium hydroxide in the normal liver parenchyma so as to assess its possibility in treatment of liver cancer instead of ethanol. METHODS: Twenty-seven New Zealand rabbits were di- vided randomly into 9 groups (Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, and Cc) by a 3 × 3 (three-by-three) factorial de- sign, each consisting of 3 rabbits. Group A was given sodi- um hydroxide solution at a concentration of 5%, while B at 2.5% and C at 1% in liver parenchyma. Each group re- ceived three doses of the solution: a (0.2 ml), b (0.5 ml) and c (1.0 ml). Then another 3 rabbits as side-effect group were dropped with sodium hydroxide solution in their liver lobe space. Liver and renal function changes in all the rab- bits were compared after injection with pre-injection. RESULTS: All the lesions were localized. At the concentra- tion of 2.5% and 5%, the lesion volume increased with the dose increased from 0.2 ml to 1.0 ml (P < 0. 05). No sig- nificant differences were found in the lesion volume of the groups receiving the same dose but different concentration. Changes in liver and renal function were not significant 7 days after injection, compared with those before injection. CONCLUSIONS: 2.5% and 5% sodium hydroxide solution could control local complete necrosis in normal liver. With regard to safety, 2.5% alkali solution is considered promis- ing as a new agent for intratumoral injection therapy in- stead of ethanol.展开更多
Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport...Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.展开更多
Light weight and mechanically strong α-chitin aerogels were fabricated using the sol-gel/self-assembly method from α-chitin in different aqueous alkali hydroxide(KOH, Na OH and Li OH)/urea solutions. All of the α-c...Light weight and mechanically strong α-chitin aerogels were fabricated using the sol-gel/self-assembly method from α-chitin in different aqueous alkali hydroxide(KOH, Na OH and Li OH)/urea solutions. All of the α-chitin solutions exhibited temperature-induced rapid gelation behavior. 13 C nuclear magnetic resonance(NMR) spectra revealed that the aqueous alkali hydroxide/urea solutions are non-derivatizing solvents for α-chitin. Fourier transform infrared(FT-IR), X-ray diffraction(XRD) and cross-polarization magic angle spinning(CP/MAS) 13 C NMR confirmed that α-chitin has a stable aggregate structure after undergoing dissolution and regeneration. Subsequently, nanostructured α-chitin aerogels were fabricated by regeneration from the chitin solutions in ethanol and then freeze-drying from t-Bu OH. These α-chitin aerogels exhibited high porosity(87% to 94%), low density(0.09 to 0.19 g/cm^3), high specific surface area(419 to 535 m^2/g) and large pore volume(2.7 to 3.8 cm^3/g). Moreover, the α-chitin aerogels exhibited good mechanical properties under compression and tension models. In vitro studies showed that m BMSCs cultured on chitin hydrogels have good biocompatibility. These nanostructured α-chitin aerogels may be useful for various applications, such as catalyst supports, carbon aerogel precursors and biomedical materials.展开更多
A waste heat recovery and denitrification system was developed for improving energy conservation and emissions control especially for control of PM2.5 particles and haze. The system uses enhanced heat and mass transfe...A waste heat recovery and denitrification system was developed for improving energy conservation and emissions control especially for control of PM2.5 particles and haze. The system uses enhanced heat and mass transfer techniques in a packed heat exchange tower with self-rotation and zero-pressure spraying, low temperature NO oxidation by ozone, and neutralization with an alkali solution. Operating data in a test project gave NOx in the exhaust flue gas of less than 30 mg/Nm3 with an ozone addition rate of 8 kg/h and spray water p H of 7.5–8, an average heat recovery of 3 MW, and an average heat supply of 7.2 MW.展开更多
基金Project(51125018)supported by the National Science Found for Distinguished Young Scholars of ChinaProject(2011BAC06B07)supported by the National Key Technologies R&D Program of China+2 种基金Project(2011AA060704)supported by the National Hi-tech Research and Development Program of ChinaProjects(51204153,21106167)supported by the National Natural Science Foundation of ChinaProjects(2012M510552,2013T60175)supported by Financial Grant from the China Postdoctoral Science Foundation
文摘In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralization curve, Al（OH）3 precipitation efficiency and induction period of bayerite were investigated. The results indicate that the neutralization curve of the artificial chromate alkali solutions shows three distinct regions and its induction period is longer than that of pure sodium aluminate solutions at the same aluminum concentration. And the decreased temperature and volume fraction of CO2 enhance the particle size of bayerite β-Al（OH）3. Bayerite composed of agglomerates of rods and cone frustums was obtained from alkali metal chromate solutions with 28.5% CO2（volume fraction） at temperatures ranging from 50 °C to 70 °C. Coarse bayerite with particle size（d50） from 24.2 μm to 29.3 μm extremely has few impurities, which is suitable for comprehensive utilization.
基金financially supported by the National Natural Science Foundation of China (No. 21300212)
文摘Carbon dioxide mineral sequestration with steelmaking slag is a promising method for reducing carbon dioxide in a large- scale setting. Existing calcium oxide or calcium hydroxide in steelmaking slag can be easily leached by water, and the formed calcium carbonate can be easily wrapped on the surface of unreacted steelmaking slag particles. Thus, further increase in the carbonation reaction rate can be prevented. Enhanced carbon dioxide mineral sequestration with steel- making slag in dilute alkali solution was analysed in this study through experiments and process evaluation. Operating conditions, namely alkali concentration, reaction temperature and time, and liquid-to-solid ratio, were initially investigated. Then, the material and energy balance of the entire process was calculated, and the net carbon dioxide sequestration efficiency at different reaction times was evaluated. Results showed that dilute alkali solution participated in slowing down the leaching of active calcium in the steelmaking slag and in significantly improving carbonation conversion rate. The highest carbonation conversion rate of approximately 50% can be obtained at the optimal conditions of 20 g/L alkali concentration, 2 mL/L liquid-to-solid ratio, and 70 ℃ reaction temperature. Carbonation reaction time significantly influences the net carbon dioxide sequestration efficiency. According to calculation, carbon dioxide emission of 52.6 kg/t- slag was avoided at a relatively long time of 120 min.
基金Supported by the National Natural Science Foundation of China(21729601,21776123)the Doctoral Program of Higher Education(20133221110001)+1 种基金the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Kempe Foundations,and Swedish Energy Agency(P40548-1).
文摘In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.
文摘Filtering materials are chosen according to the mechanism of blood filtration and mathematics model, then the material is treated with amine and alkali solution. There is cooperation and synergism between alkali and amine, and the actions are realized in three stages. After modification the material treated has accessibility groups NH 2 , and slits appeared in the surface of fiber, so the wettability of materials is improved distinctly; the diameter and aperture of fiber have no changes basically.
文摘In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.
文摘The performance of roller compacted concrete(RCC)was greatly influenced by variations in material proportion,optimum moisture content,density of mixes and methodology adopted making it different from conventional concrete mixes.Even though RCC has gained popularity,the complex phenomenon involved in developing the RCC mixes limits it from large-scale applications.In this study,reclaimed asphalt pavement(RAP)incorporated roller-compacted geopolymer concrete(RGC)mixes were developed herein with different compaction techniques such as vibratory hammer(VH),modified proctor(MP),vibration table(VT)and compression machine(CM)are studied and compared with control mixes of natural aggregates.Initially,the effect of alkali solutions such as sodium hydroxide(SH)and sodium silicate(SS)on the physical properties.During,the second phase mechanical properties such as dry density,compressive,flexural and split-tensile strength,modulus of elasticity and microstructure properties will be investigated.The test results revealed that compaction efforts were greatly influenced by the alkali solution.Furthermore,the poor bond characteristics between RAP and the binder matrix had a significant effect on strength properties.Also,the various compaction techniques affected the mechanical properties of mixes developed herein.In Comparison with various compaction efforts,VH and MP produced comparable results,whereas the VT method underestimated and overestimated the various strength properties.Although,the CM method reports comparable results but difficult to maintain consistency in strength aspects.Therefore,optimization of various parameters influencing the concrete properties needs to be achieved for field density.
文摘BACKGROUND: Percutaneous ethanol injection has been widely used as a non-surgical therapy for liver cancer, but it has some shortcomings such as local diffusion and une- qual permeation. This study was designed to observe the volume, controllability and completeness of necrosis after injection of low concentration sodium hydroxide in the normal liver parenchyma so as to assess its possibility in treatment of liver cancer instead of ethanol. METHODS: Twenty-seven New Zealand rabbits were di- vided randomly into 9 groups (Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, and Cc) by a 3 × 3 (three-by-three) factorial de- sign, each consisting of 3 rabbits. Group A was given sodi- um hydroxide solution at a concentration of 5%, while B at 2.5% and C at 1% in liver parenchyma. Each group re- ceived three doses of the solution: a (0.2 ml), b (0.5 ml) and c (1.0 ml). Then another 3 rabbits as side-effect group were dropped with sodium hydroxide solution in their liver lobe space. Liver and renal function changes in all the rab- bits were compared after injection with pre-injection. RESULTS: All the lesions were localized. At the concentra- tion of 2.5% and 5%, the lesion volume increased with the dose increased from 0.2 ml to 1.0 ml (P < 0. 05). No sig- nificant differences were found in the lesion volume of the groups receiving the same dose but different concentration. Changes in liver and renal function were not significant 7 days after injection, compared with those before injection. CONCLUSIONS: 2.5% and 5% sodium hydroxide solution could control local complete necrosis in normal liver. With regard to safety, 2.5% alkali solution is considered promis- ing as a new agent for intratumoral injection therapy in- stead of ethanol.
基金the Zernike Institute for Advanced Materials for the startup fundsChina Scholarship Council(201606340158)。
文摘Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.
基金supported by the National Natural Science Foundation of China (21422405, 51373125)the Major Program of National Natural Science Foundation of China (21334005)+1 种基金the facility support of the Natural Science Foundation of Hubei Provincethe Fundamental Research Funds for the Central Universities
文摘Light weight and mechanically strong α-chitin aerogels were fabricated using the sol-gel/self-assembly method from α-chitin in different aqueous alkali hydroxide(KOH, Na OH and Li OH)/urea solutions. All of the α-chitin solutions exhibited temperature-induced rapid gelation behavior. 13 C nuclear magnetic resonance(NMR) spectra revealed that the aqueous alkali hydroxide/urea solutions are non-derivatizing solvents for α-chitin. Fourier transform infrared(FT-IR), X-ray diffraction(XRD) and cross-polarization magic angle spinning(CP/MAS) 13 C NMR confirmed that α-chitin has a stable aggregate structure after undergoing dissolution and regeneration. Subsequently, nanostructured α-chitin aerogels were fabricated by regeneration from the chitin solutions in ethanol and then freeze-drying from t-Bu OH. These α-chitin aerogels exhibited high porosity(87% to 94%), low density(0.09 to 0.19 g/cm^3), high specific surface area(419 to 535 m^2/g) and large pore volume(2.7 to 3.8 cm^3/g). Moreover, the α-chitin aerogels exhibited good mechanical properties under compression and tension models. In vitro studies showed that m BMSCs cultured on chitin hydrogels have good biocompatibility. These nanostructured α-chitin aerogels may be useful for various applications, such as catalyst supports, carbon aerogel precursors and biomedical materials.
基金supported by the National Basic Research Program of China(Grant No.2013CB228301)
文摘A waste heat recovery and denitrification system was developed for improving energy conservation and emissions control especially for control of PM2.5 particles and haze. The system uses enhanced heat and mass transfer techniques in a packed heat exchange tower with self-rotation and zero-pressure spraying, low temperature NO oxidation by ozone, and neutralization with an alkali solution. Operating data in a test project gave NOx in the exhaust flue gas of less than 30 mg/Nm3 with an ozone addition rate of 8 kg/h and spray water p H of 7.5–8, an average heat recovery of 3 MW, and an average heat supply of 7.2 MW.
