Universidade Federal de Santa Maria

About: Universidade Federal de Santa Maria is a education organization based out in Santa Maria, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 21178 authors who have published 35632 publications receiving 371665 citations.

Green technologies for the extraction of bioactive compounds in fruits and vegetables

Abstract: Bioactive compounds are extracted from natural sources and they have beneficial effects on human health. Fruits and vegetables are rich in carotenoids, phenolic compounds, Vitamin C, among others. Extraction processes for these compounds depend on several factors such as the technique that is used, the raw material, and the organic solvent. Conventional techniques generally require large amounts of organic solvents, high energy expenditure, and are time consuming, which has generated interest in new technologies that are referred to as clean or green technologies. These can reduce or eliminate the use of toxic solvents, and thus preserve the natural environment and its resources. The aim of this review is to discuss recent techniques used to extract bioactive compounds from natural sources, in order to reduce the economic and ecological impact of these processes.

Atributos físicos do solo em sistema de integração lavoura-pecuária sob plantio direto

Abstract: Soil compaction is one of the most important reasons for decrease in crop yield. The impact of animal trampling on integrated beef cattle raising-crop production systems were studied to evaluate the changes in soil physical properties (bulk density, porosity, soil resistance to penetration and soil water infiltration). The field experiment was carried out in Jari, in the mid- plateau region of Rio Grande do Sul State, Brazil. Three management systems of winter pastures (black oat; Avena strigosa Schreber + ryegrass; Lolium multiflorum Lam.) were studied under different grazing frequencies: (1) No grazing (NG), (2) grazing every 28 days (G28) and (3) grazing every fourteen days (G14). The summer crops soybean (Glycine max (L.) Merr.) or corn (Zea mays L.), as antecedent crop in rotation to the winter pastures, were also studied to measure the increasing or decreasing effects on compaction by animal trampling. The greatest effects of animal trampling were concentrated in the top soil layer (0 to 0.05 m), but under the highest grazing frequency (G14) macroporosity was reduced down to the 0.10-0.15 m layer. The soil resistance to penetration had peaks of 2.61 and 2.49 MPa in the G28 and G14 treatments, respectively, in the 0.05-0.08 layer. In the ungrazed areas the values remained lower, around 1.66 MPa. Soil water infiltration was significantly affected by animal trampling and by the previous summer crop. In the case of corn area, the soil was less sensitive to cattle trampling, unlike in the areas following soybean, where the highest grazing frequency (G14) reduced the water infiltration rates. Soybean induced higher values of macroporosity in the evaluated soil layers; when related with lower beef cattle density or ungrazed pastures, the rates of water infiltration and accumulated infiltration were higher.

Spectropolarimetry of Magnetospheric Accretion on the Classical T Tauri Star BP Tauri

Abstract: High-resolution (R ≈ 60,000) circular spectropolarimetry of the classical T Tauri star BP Tauri is presented No net polarization is detected in photospheric absorption lines, placing strong limits (3 σ) on the mean longitudinal magnetic field (±200 G) that is present over the surface of the star On the other hand, strong circular polarization is measured in the He I λ5876 emission line of BP Tau, indicating a mean longitudinal magnetic field of 2460±120 G in the line formation region This implies that accretion occurs preferentially along large-scale magnetic loops that occupy a small fraction of the stellar surface These observations represent the first direct evidence for magnetically controlled accretion onto classical T Tauri stars