São Paulo Federal Institute of Education, Science and Technology

About: São Paulo Federal Institute of Education, Science and Technology is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1707 authors who have published 2374 publications receiving 11333 citations.

Degradation of amicarbazone herbicide by photochemical processes

Abstract: Amicarbazone is a triazolinone herbicide developed to replace atrazine in the world market. Several technologies have been studied aiming at removing pesticides from wastewater, seeking to study the degradation mechanisms involved and the degree of toxicity of the transformation products formed. In this context, our main goal was to study the degradation of amicarbazone in aqueous solution by direct photolysis, suggesting possible chemical structures for the transformation products according to a theoretical and fundamental approach. The effects of herbicide initial concentration, pH, dissolved oxygen and nitrate concentrations, the role of singlet oxygen, and the presence of propan-2-ol as a free radical scavenger in amicarbazone photodegradation are discussed for the first time. Among these variables, pH showed influence on the photochemical degradation pathway. For instance, the transformation product amicarbazole was obtained under mildly acidic conditions, while 4-amino-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide intermediate was found in both acidic and basic conditions. A primary degradation product formed as a result of deamination in acidic medium was found out. Concerning the effect of the variables involved in the process, the lowest AMZ half-life of 120 min was achieved under the following conditions: pH = 3; [AMZ]0 = 50 mg L−1; 75 W LP-Hg lamp.

Microwave discharge electrodeless mercury lamp (Hg-MDEL): An energetic, mechanistic and kinetic approach to the degradation of Prozac®

Abstract: A photochemical reactor composed of an Hg-MDEL was applied in photodegradation studies of fluoxetine (Prozac®). The reactor exhibited to be an efficient hydroxyl radical generation system, since the O • H quantification studies conducted with coumarin (COU), 4-hydroxycoumarin (4HC) and 7-hydroxycoumarin (7HC) solutions resulted in the kinetics constant of formation of O • H kOH = 3.14 ± 0.18 min−1. When the Hg-MDEL reactor was applied for degradation of Prozac®, the study of variation of the microwave power allowed a significant increase in the rate of degradation of the Prozac®, indicating that the hydroxyl radical formation is optimized through the adjustment of this parameter. An increase in the initial concentration of Prozac from 33 to 134 μmol L−1 resulted in a 21% decrease in the kinetic constant value, the mean kinetic constant was k = 10.64 ± 1.25 min −1 and R 2 = 0.943 ± 0.131. The Prozac® photodegradation studies showed that the application of the pseudo-first-order kinetics should be limited to the time of up to 0.50 min for the respective system, due to the influence exerted by the transformation products. In general, the total removal of Prozac® was 100% for its highest concentration (134 μmol L−1) at the time of 0.75 min. As for the solution of Prozac® 101 μmol L−1, the energy consumption was 6 kW h g−1, achieving a removal of 99%. Finally, the photochemical system presented in this work demonstrates a high efficiency in the formation of hydroxyl radicals, a high degradation rate of organic compounds (Prozac®, COU and 7HC) and low energy consumption.

Equatorial electrojet responses to intense solar flares under geomagnetic disturbance time electric fields

Abstract: Large enhancement in the equatorial electrojet (EEJ) current can occur due to sudden increase in the E layer density arising from solar flare associated ionizing radiations, as also from background electric fields modified by magnetospheric disturbances when present before or during a solar flare. We investigate the EEJ responses at widely separated longitudes during two X-class flares that occurred at different activity phases surrounding the magnetic super storm sequences of 28–29 October 2003. During the 28 October flare we observed intense reverse electrojet under strong westward electric field in the sunrise sector over Jicamarca. Sources of westward disturbance electric fields driving large EEJ current are identified for the first time. Model calculations on the E layer density, with and without flare, and comparison of the results between Jicamarca and Sao Luis suggested enhanced westward electric field due to the flare occurring close to sunrise (over Jicamarca). During the flare on 29 October, which occurred during a rapid AE recovery, a strong overshielding electric field of westward polarity over Jicamarca delayed an expected EEJ eastward growth due to flare-induced ionization enhancement in the afternoon. This EEJ response yielded a measure of the overshielding decay time determined by the storm time Region 2 field-aligned current. This paper will present a detailed analysis of the EEJ responses during the two flares, including a quantitative evaluation of the flare-induced electron density enhancements and identification of electric field sources that played dominant roles in the large westward EEJ at the sunrise sector over Jicamarca.

Effects of continuous and intermittent aerobic physical training on hormonal and metabolic profile, and body composition in women with polycystic ovary syndrome: A randomized controlled trial.

Abstract: Objective To evaluate the effects of continuous (CA) and intermittent (IA) aerobic training on hormonal and metabolic parameters and body composition of women with polycystic ovary syndrome (PCOS). Design Prospective, interventional, randomized study. Methods Randomized controlled training (RCT) with sample allocation and stratification into three groups: CAT (n = 28) and IAT (n = 29) training and no training [control (CG), n = 30]. Before and after 16 weeks of intervention (CAT or IAT) or observation (CG), hormonal and metabolic parameters, body composition and anthropometric indices were evaluated. Aerobic physical training on a treadmill consisted of 30- to 50-minute sessions with intensities ranging from 60% to 90% of the maximum heart rate. Results In the CA group, there was reduction in waist circumference (WC) (P = .045), hip circumference (P = .032), cholesterol (P ≤ .001), low-density lipoprotein (P = .030) and testosterone (P ≤ .001). In the IAT group, there was a reduction in WC (P = .014), waist-to-hip ratio (P = .012), testosterone (P = .019) and the free androgen index (FAI) (P = .037). The CG showed increases in WC (P = .049), total body mass (P = .015), body fat percentage (P = .034), total mass of the arms (P ≤ .001), trunk fat percentage (P = .033), leg fat percentage (P = .021) and total gynoid mass (P = .011). Conclusion CAT and IAT training reduced anthropometric indices and hyperandrogenism in PCOS, whereas only IAT training reduced the FAI. Furthermore, only CAT training improved the lipid profile.