This study was conducted to investigate the effects of carbon dioxide (CO2) and modified atmosphere (MA) packaging on the quality of strawberry during long distance transportation. “Maehyang” strawberries (Fragaria ...This study was conducted to investigate the effects of carbon dioxide (CO2) and modified atmosphere (MA) packaging on the quality of strawberry during long distance transportation. “Maehyang” strawberries (Fragaria x ananassa Duch.) with red color on 70% of the fruit surface were harvested in Gyeongnam province, Korea. The samples were placed in gas-tight chamber with 30% CO2 concentration for 3 hours at 3°C. Strawberry samples were then packaged with modified atmosphere-modified humidity (MA/MH) packaging film. Samples treated with CO2 alone and combined CO2 with MA packaging were stored for one day at 1°C, transported for 10 days at 1°C, and distributed for 3 days at 4°C. Carbon dioxide alone or combination with MA packaging was effective in maintaining quality of “Maehyang” strawberries. Carbon dioxide treatment significantly increased firmness and reduced softening index and decay rate during 14 day transportation and distribution. Samples treated with CO2 + MA had higher overall score with low softening index and weight loss after 14 days of transportation and low temperature distribution compared to CO2 treatment only. The results indicated that a short term application of CO2 or combination treatment of CO2 and MA could be good postharvest handling for maintaining freshness of “Maehyang” strawberries during long distance vessel export.展开更多
High voltage,high energy density,nominal cycle life,and low cost are the most critical requirements of rechargeable batteries for their widespread energy storage applications in electric vehicles and renewable energy ...High voltage,high energy density,nominal cycle life,and low cost are the most critical requirements of rechargeable batteries for their widespread energy storage applications in electric vehicles and renewable energy technologies.Na-MnO_(2) battery could be a low-cost contender,but it suffers extensively from its low cell voltage and poor rechargeability.In this study,we modified the conventional cell structure of Na-MnO_(2) battery and established altered cell chemistry through a hybrid electrochemical process consisting of Na striping/plating at the anode and Zn^(2+) insertion/de-insertion along with MnO_(2) dissolution/deposition at the cathode.After the modification,Na-MnO_(2) battery exhibits a discharge capacity of 267.10 mA h/g and a cell voltage of 3.30 V(vs.Na/Na^(+)),resulting in a high specific energy density of 881.43 Wh/kg.After 300 cycles,the battery retains 98% of its first-cycle discharge capacity with100% coulombic efficiency.Besides,Na metal-free battery assembled using sodium biphenyl as a safer anode also delivers an excellent energy density of 810.0 Wh/kg.This work could provide a feasible method to develop an advanced Na-MnO_(2) battery for real-time energy storage applications.展开更多
A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperatu...A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperature were taken as input variables. Based on the central composite design (BBD) response surface model, two functional relationship models between three independent variables and glyphosate removal rate were established to evaluate the influence degree of independent variables and interaction on catalyst. The significance of the model and regression coefficient was tested by variance analysis. The analysis of the obtained data showed that the degradation performance of the composite photocatalyst was significantly affected by the calcination temperature and the rate of N doping, while the rate of Ce doping had little effect;at the calcination temperature of 505.440°C, the degradation rate of glyphosate reached the maximum of 82.15% under the preparation conditions of 17.057 mol% N doping and 0.165 mol% Ce doping, respectively.展开更多
Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the s...Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the surface acid-base properties of catalysts by introduction of alkali metal （Na, K） oxides inhibits the carbonization and as a result, improves the operational stability of these catalysts. An effect of promotion of nickel-alumina based composite doped by lanthanum oxide is found. This effect, caused by an additional route for the CO2 activation on Ni-La2O3/Al2O3/cordierite catalyst, is displayed in increase of methane conversion under conditions of an oxidant excess.展开更多
Iridium dioxide with different morphologies(nanorod and nanogranular) is successfully prepared by a modified sol-gel and Adams methods. The catalytic activity of both samples for oxygen reduction reaction is investiga...Iridium dioxide with different morphologies(nanorod and nanogranular) is successfully prepared by a modified sol-gel and Adams methods. The catalytic activity of both samples for oxygen reduction reaction is investigated in an alkaline solution. The electrochemical results show that the catalytic activity of the nanogranular Ir O2 sample is superior to that of the nanorod sample due to its higher onset potential for oxygen reduction reaction and higher electrode current density in low potential region. The results of Koutecky-Levich analysis indicate that the oxygen reduction reaction catalyzed by both samples is a mixture transfer pathway. It is dominated by four electron transfer pathway for both samples in high overpotential area, while it is controlled by two electron transfer process for both samples in low overpotential area.展开更多
Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulation...Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulations is designed using nanostructured working electrodes.Surface functionalization with manganese dioxide(MnO_(2))/fullerene-C_(60) nanocomposite exhibited the highest electrochemical responses with a sharp oxidation peak at about 336 mV that was obtained using the differential pulse voltammetry(DPV).The cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)were applied,while the electrode matrix composition including types of nanomaterials,electroanalytical parameters,and pH eff ect were optimized.To that end,using the DPV,high sensitivity was obtained from the linear calibration curve ranged from 0.8 to 31.5μg·mL^(-1) with the correlation coe fficient of 0.99,limit of detection of 0.76μg·mL^(-1) and limit of quantification of 2.31μg·mL^(-1) .Accordingly,the designed approach is off ering a potential applicability towards the RFX determination in pharmaceutical preparations and its quality control.展开更多
文摘This study was conducted to investigate the effects of carbon dioxide (CO2) and modified atmosphere (MA) packaging on the quality of strawberry during long distance transportation. “Maehyang” strawberries (Fragaria x ananassa Duch.) with red color on 70% of the fruit surface were harvested in Gyeongnam province, Korea. The samples were placed in gas-tight chamber with 30% CO2 concentration for 3 hours at 3°C. Strawberry samples were then packaged with modified atmosphere-modified humidity (MA/MH) packaging film. Samples treated with CO2 alone and combined CO2 with MA packaging were stored for one day at 1°C, transported for 10 days at 1°C, and distributed for 3 days at 4°C. Carbon dioxide alone or combination with MA packaging was effective in maintaining quality of “Maehyang” strawberries. Carbon dioxide treatment significantly increased firmness and reduced softening index and decay rate during 14 day transportation and distribution. Samples treated with CO2 + MA had higher overall score with low softening index and weight loss after 14 days of transportation and low temperature distribution compared to CO2 treatment only. The results indicated that a short term application of CO2 or combination treatment of CO2 and MA could be good postharvest handling for maintaining freshness of “Maehyang” strawberries during long distance vessel export.
基金supported by the Korea Research Fellowship Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2016H1D3A1909680)supported by Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE) (20215610100040), Development of 20Wh seawater secondary battery unit cellminsisterio de Economia y competitividal (Spain) for the financially supporting this study through Juan de la Cierva-Incorporación program (IJC2018-038426-I)。
文摘High voltage,high energy density,nominal cycle life,and low cost are the most critical requirements of rechargeable batteries for their widespread energy storage applications in electric vehicles and renewable energy technologies.Na-MnO_(2) battery could be a low-cost contender,but it suffers extensively from its low cell voltage and poor rechargeability.In this study,we modified the conventional cell structure of Na-MnO_(2) battery and established altered cell chemistry through a hybrid electrochemical process consisting of Na striping/plating at the anode and Zn^(2+) insertion/de-insertion along with MnO_(2) dissolution/deposition at the cathode.After the modification,Na-MnO_(2) battery exhibits a discharge capacity of 267.10 mA h/g and a cell voltage of 3.30 V(vs.Na/Na^(+)),resulting in a high specific energy density of 881.43 Wh/kg.After 300 cycles,the battery retains 98% of its first-cycle discharge capacity with100% coulombic efficiency.Besides,Na metal-free battery assembled using sodium biphenyl as a safer anode also delivers an excellent energy density of 810.0 Wh/kg.This work could provide a feasible method to develop an advanced Na-MnO_(2) battery for real-time energy storage applications.
文摘A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperature were taken as input variables. Based on the central composite design (BBD) response surface model, two functional relationship models between three independent variables and glyphosate removal rate were established to evaluate the influence degree of independent variables and interaction on catalyst. The significance of the model and regression coefficient was tested by variance analysis. The analysis of the obtained data showed that the degradation performance of the composite photocatalyst was significantly affected by the calcination temperature and the rate of N doping, while the rate of Ce doping had little effect;at the calcination temperature of 505.440°C, the degradation rate of glyphosate reached the maximum of 82.15% under the preparation conditions of 17.057 mol% N doping and 0.165 mol% Ce doping, respectively.
文摘Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the surface acid-base properties of catalysts by introduction of alkali metal （Na, K） oxides inhibits the carbonization and as a result, improves the operational stability of these catalysts. An effect of promotion of nickel-alumina based composite doped by lanthanum oxide is found. This effect, caused by an additional route for the CO2 activation on Ni-La2O3/Al2O3/cordierite catalyst, is displayed in increase of methane conversion under conditions of an oxidant excess.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2012CB215504)the National Natural Science Foundation of China(No.50632050)+1 种基金the Doctoral Fund of Ministry of Education of China(No.20130143130001)Hubei Provincial Key Laboratory of Fuel Cell(2015FCJ001)
文摘Iridium dioxide with different morphologies(nanorod and nanogranular) is successfully prepared by a modified sol-gel and Adams methods. The catalytic activity of both samples for oxygen reduction reaction is investigated in an alkaline solution. The electrochemical results show that the catalytic activity of the nanogranular Ir O2 sample is superior to that of the nanorod sample due to its higher onset potential for oxygen reduction reaction and higher electrode current density in low potential region. The results of Koutecky-Levich analysis indicate that the oxygen reduction reaction catalyzed by both samples is a mixture transfer pathway. It is dominated by four electron transfer pathway for both samples in high overpotential area, while it is controlled by two electron transfer process for both samples in low overpotential area.
基金the great gratitude to the project fund received from the National Research Centre(NRC,Cairo,Egypt)for the internal grant(No.11090306)。
文摘Rifaximin(RFX)is a broad-spectrum oral antibiotic with bactericidal actions against Gram-negative and Gram-positive bacteria.In the present work,a sensitive voltammetric assay for the RFX in pharmaceutical formulations is designed using nanostructured working electrodes.Surface functionalization with manganese dioxide(MnO_(2))/fullerene-C_(60) nanocomposite exhibited the highest electrochemical responses with a sharp oxidation peak at about 336 mV that was obtained using the differential pulse voltammetry(DPV).The cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)were applied,while the electrode matrix composition including types of nanomaterials,electroanalytical parameters,and pH eff ect were optimized.To that end,using the DPV,high sensitivity was obtained from the linear calibration curve ranged from 0.8 to 31.5μg·mL^(-1) with the correlation coe fficient of 0.99,limit of detection of 0.76μg·mL^(-1) and limit of quantification of 2.31μg·mL^(-1) .Accordingly,the designed approach is off ering a potential applicability towards the RFX determination in pharmaceutical preparations and its quality control.
