Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria ( Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides) from alcoholic fermentation, through the method of minimum inhibitory concentration ( MIC), as well as its effect on the industrial yeast inoculum. Lower MIC was found for B. subtilis ( 10 ppm) and Leuconostoc mesenteroides ( 50 ppm) than for Lactobacillus fermentum ( 75 ppm) and Lactobacillus plantarum ( 125 ppm). Additionally, these concentrations of chlorine dioxide had similar effects on bacteria as 3 ppm of Kamoran (R) ( recommended dosage for fermentation tanks), exception for B. subtilis, which could not be controlled at this Kamoran (R) dosage. The growth of industrial yeasts was affected when the concentration of chlorine dioxide was higher than 50 ppm, but the effect was slightly dependent on the type of yeast strain. Smooth yeast colonies ( dispersed cells) seemed to be more sensitive than wrinkled yeast colonies ( clustered cells/pseudohyphal growth), both isolated from an alcohol-producing unit during the 2006/2007 sugar cane harvest. The main advantage in the usage of chlorine dioxide that it can replace antibiotics, avoiding the selection of resistant populations of microorganisms.

Effect of an alcoholic diet on dental caries and on Streptococcus of the mutans group: Study in rats

The objective of this study was to evaluate the effects of an alcohol diet on Streptococcus of the mutans group and on dental caries in the oral cavity of rats. Forty animals were divided into 3 groups according to the following liquid diets: 20% ethanol solution (Alcohol Group, AG), 27% sucrose solution (Isocaloric Group, IG), and water (Control Group, CG). After 56 days, samples were collected and plated on Mitis Salivarius Bacitracin agar to assess the number of colony forming units (CFU/mL) of Streptococcus of the mutans group. The animals were sacrificed and the jaws were removed in order to assess the occurrence of dental caries on the smooth and occlusal surfaces using stereomicroscopy. The data were submitted to ANOVA and Tukey test. The average numbers of CFU/mL (10 3) were: 8.17 (AG), 9.78 (IG), and 5.63 (CG). There was no significant difference among the groups for the occurrence of occlusal caries. Regarding smooth surface caries, in the upper jaw, the caries number in the IG (1.58) was similar to that in the AG (2.06) and in the CG (1.14), and the number of caries in the AG was higher than in the CG; in the lower jaw there was significant difference among the 3 groups: AG (1.14), IG (2.00) and CG (0.43). The diets with the alcohol and sucrose solutions presented a tendency of increasing the colonization by Streptococcus of the mutans group and of increasing the occurrence of smooth surface dental caries in rat molars when compared to the control diet.

AC-DC three-phase multipulse converter with boost DC-DC stage and constant hysteresis control

This work proposes a new three-phase multipulse rectifier based on the delta autotransformer connection with DC-DC Boost stages and constant hysteresis control which has the objective of providing a reliable DC bus for on-board applications, electric motor drives and similars, always considering power quality issues. Thus, the proposal presents 0.99 power factor, 6% harmonic distortions in the currents from the mains and enhanced magnetic core utilization, which results in low weight and volume for the overall converter. The proposed control technique uses the simple constant hysteresis concept, thus leading to a low-cost but effective and reliable strategy. © 2011 IEEE.

Study of Brazilian commercial Oriented Strand Board panels using stress wave

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Internal Combustion Engine's Throttle Control as a Motivational Theme for Teaching Microprocessors Systems Lab Classes

The increased fuel economy and driveability of modern internal combustion engine vehicles (ICEVs) are the result of the application of advanced digital electronics to control the operation of the internal combustion engine (ICE). Microprocessors (and micro controllers) play a key role in the engine control, by precisely controlling the amount of both air and fuel admitted into the cylinders. Air intake is controlled by utilizing a throttle valve equipped with a motor and gear mechanism as actuator, and a sensor enabling the measurement of the angular position of the blades. This paperwork presents a lab setup that allows students to control the throttle position using a microcontroller that runs a program developed by them. A commercial throttle body has been employed, whereas a power amplifier and a microcontroller board have been hand assembled to complete the experimental setup. This setup, while based in a high-tech, microprocessor-based solution for a real-world, engine operation optimization problem, has the potential to engage students around a hands-on multidisciplinary lab activity and ignite their interest in learning fundamental and advanced topics of microprocessors systems.

Effects of an isotonic beverage on autonomic regulation during and after exercise

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Non-alcoholic fatty liver disease and its associated risk factors in Brazilian postmenopausal women

Objective To evaluate the prevalence and risk factors of non-alcoholic fatty liver disease (NAFLD) in postmenopausal women.Methods A cross-sectional study was carried involving 188 women (age >= 45 years and amenorrhea >= 12 months) attending the outpatient unit in south-eastern Brazil. Exclusion criteria were liver disease (hepatitis B and C, cholestatic disease, liver insufficiency), use of drugs that affect liver metabolism; alcoholics; AIDS or cancer history; and morbid obesity. NAFLD was diagnosed by abdominal ultrasound. Clinical, anthropometric (body mass index, waist circumference) and biochemical variables were measured.Results Of the 188 women, 73 (38.8%) had NAFLD. Blood pressure, waist circumference, body mass index, LDL cholesterol, triglycerides and glucose were significantly higher in NAFLD patients when compared with women without NAFLD (control group) (p < 0.05). HOMA-IR values indicated insulin resistance only in the NAFLD group (6.1 +/- 4.6 vs. 2.4 +/- 1.4 in control group, p < 0.05). Metabolic syndrome was detected in 93.1% of the women affected by NAFLD, and 46.1% of the control group (p < 0.05). In multivariate analysis, adjusted for age and weight, the variables considered at risk for the development of NAFLD, were: high waist circumference (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01-1.13), insulin resistance (OR 3.81, 95% CI 2.01-7.13), and presence of metabolic syndrome (OR 8.68, 95% CI 3.3-24.1).Conclusion NAFLD showed a high prevalence among postmenopausal women. The presence of metabolic syndrome, abdominal obesity and IR were indicators of risk for the development of NAFLD.

Yeast CA-11 fermentation in musts treated with brown and green propolis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)