Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support...Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support. For this reason, research efforts focused on this area have been responsible for optimizing the process of biodiesel production by different catalytic routes to achieve greater efficiency at a lower cost. In this case, the biggest problem has been the high cost generated by an investigation, which in many occasions is the main factor to decide if an investigation could be carried out. Trying to reduce these costs, in the current study, we are using a technique of glycerol quantification by volumetric methods and comparing obtained results with the chromatographic method, which is conventionally used and comparatively much more expensive. Biodiesel employee was obtained by an enzymatic catalysis process varying one of three process variables：oil：alcohol molar ratio, temperature and proportion of catalyst. The numerical differences obtained between the two quantification methods generated relative errors lower than 10%, resulting in some occasions lower than 1%. By gas chromatography analysis the best yield was obtained at the same conditions of the volumetric method, a temperature of 45 ℃, an oil：alcohol ratio 1：4 and 8 wt.% of catalyst, but a yield of 95.5% and 97.1%, respectively. Due to the high precision of gas chromatography, this method is used to carry out a surface response analysis obtaining as ideal operating conditions a temperature of 43.5 ℃, 8.9 wt.%. of catalyst and an oil：alcohol ratio 1：4.展开更多
In this paper, it presents a project of a fuzzy controller and a neural estimator to control a coordinate table powered by three-phase induction motor, aiming to implement an intelligent milling system. The position/s...In this paper, it presents a project of a fuzzy controller and a neural estimator to control a coordinate table powered by three-phase induction motor, aiming to implement an intelligent milling system. The position/speed control is performed using vector techniques of three-phase induction machines. The estimation of the motor electromagnetic torque is used for setting the feedrate of the table. The speed control is developed using TS （Takagi-Sugeno） fuzzy logic model and electromagnetic torque estimation using neural network type LMS （least mean square） algorithm. The induction motor is powered by a frequency inverter driven by a DSP （digital signal processor）. Control strategies are implemented in DSP. Simulation results are presented for evaluating the performance of the system.展开更多
Microbial exopolysaccharides present bioactive and technological characteristics of interest to the food and pharmaceutical industries.This study aimed to evaluate the bioactivity of the exopolysaccharide-EPS-LN60-obt...Microbial exopolysaccharides present bioactive and technological characteristics of interest to the food and pharmaceutical industries.This study aimed to evaluate the bioactivity of the exopolysaccharide-EPS-LN60-obtained from L.plantarum DF60Mi and its use as an encapsulating agent for Lactobacillus acidophilus LA-3.The prebiotic score,antioxidant activity,and cytotoxicity in human tumor and non-tumor cells were determined.Solutions of 0%(F0),0.5%(F1),and 1.0%(F2)of EPS were used as a coating for alginate capsules containing LA-3,which were evaluated for morphology,survival of LA-3 during refrigerated storage and after exposure to in vitro gastrointestinal conditions.EPS-LN60 had a higher prebiotic capacity(1.45±0.17)compared to the fructooligosaccharide(0.24±0.05)and an antioxidant activity of 1862±23.08μM FeSO4/g.Furthermore,EPS-LN60 inhibited tumor cell growth by 36%±2.78%.The capsules coated with EPS-LN60 were spherical,uniform,and efficient toward LA-3 survival(85%)after 20 days of storage.F0 did not have viable cells after 10 days.EPS-LN60 provided additional protection to the capsule,preventing loss of viability during gastrointestinal simulation conditions,resulting in survival rates greater than 86%,which was not observed in F0 when submitted to the same conditions.Therefore,the potential of EPS-LN60 was demonstrated in terms of its bioactivity and its use as an encapsulating agent for L.acidophilus LA-3,with the possibility of future exploitation as a functional ingredient by the food and pharmaceutical industries.展开更多
文摘Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support. For this reason, research efforts focused on this area have been responsible for optimizing the process of biodiesel production by different catalytic routes to achieve greater efficiency at a lower cost. In this case, the biggest problem has been the high cost generated by an investigation, which in many occasions is the main factor to decide if an investigation could be carried out. Trying to reduce these costs, in the current study, we are using a technique of glycerol quantification by volumetric methods and comparing obtained results with the chromatographic method, which is conventionally used and comparatively much more expensive. Biodiesel employee was obtained by an enzymatic catalysis process varying one of three process variables：oil：alcohol molar ratio, temperature and proportion of catalyst. The numerical differences obtained between the two quantification methods generated relative errors lower than 10%, resulting in some occasions lower than 1%. By gas chromatography analysis the best yield was obtained at the same conditions of the volumetric method, a temperature of 45 ℃, an oil：alcohol ratio 1：4 and 8 wt.% of catalyst, but a yield of 95.5% and 97.1%, respectively. Due to the high precision of gas chromatography, this method is used to carry out a surface response analysis obtaining as ideal operating conditions a temperature of 43.5 ℃, 8.9 wt.%. of catalyst and an oil：alcohol ratio 1：4.
文摘In this paper, it presents a project of a fuzzy controller and a neural estimator to control a coordinate table powered by three-phase induction motor, aiming to implement an intelligent milling system. The position/speed control is performed using vector techniques of three-phase induction machines. The estimation of the motor electromagnetic torque is used for setting the feedrate of the table. The speed control is developed using TS （Takagi-Sugeno） fuzzy logic model and electromagnetic torque estimation using neural network type LMS （least mean square） algorithm. The induction motor is powered by a frequency inverter driven by a DSP （digital signal processor）. Control strategies are implemented in DSP. Simulation results are presented for evaluating the performance of the system.
文摘Microbial exopolysaccharides present bioactive and technological characteristics of interest to the food and pharmaceutical industries.This study aimed to evaluate the bioactivity of the exopolysaccharide-EPS-LN60-obtained from L.plantarum DF60Mi and its use as an encapsulating agent for Lactobacillus acidophilus LA-3.The prebiotic score,antioxidant activity,and cytotoxicity in human tumor and non-tumor cells were determined.Solutions of 0%(F0),0.5%(F1),and 1.0%(F2)of EPS were used as a coating for alginate capsules containing LA-3,which were evaluated for morphology,survival of LA-3 during refrigerated storage and after exposure to in vitro gastrointestinal conditions.EPS-LN60 had a higher prebiotic capacity(1.45±0.17)compared to the fructooligosaccharide(0.24±0.05)and an antioxidant activity of 1862±23.08μM FeSO4/g.Furthermore,EPS-LN60 inhibited tumor cell growth by 36%±2.78%.The capsules coated with EPS-LN60 were spherical,uniform,and efficient toward LA-3 survival(85%)after 20 days of storage.F0 did not have viable cells after 10 days.EPS-LN60 provided additional protection to the capsule,preventing loss of viability during gastrointestinal simulation conditions,resulting in survival rates greater than 86%,which was not observed in F0 when submitted to the same conditions.Therefore,the potential of EPS-LN60 was demonstrated in terms of its bioactivity and its use as an encapsulating agent for L.acidophilus LA-3,with the possibility of future exploitation as a functional ingredient by the food and pharmaceutical industries.
