Instituto Federal Sul Rio Grandense
Instituto Federal Sul Rio Grandense
Meira S.M.M.,Federal University of Rio Grande do Sul |
Meira S.M.M.,Instituto Federal Sul Rio Grandense |
Zehetmeyer G.,Federal University of Rio Grande do Sul |
Werner J.O.,Federal University of Rio Grande do Sul |
Brandelli A.,Federal University of Rio Grande do Sul
Food Hydrocolloids | Year: 2017
Corn starch was used as a polymeric matrix for development of new antimicrobial packaging prepared by casting method and using nisin or pediocin for food preservation. Halloysite clay was selected as nanofiller to promote film reinforcement and a novel approach was tested using bacteriocins adsorbed on nanoclay before incorporation into film forming solutions. Active films against Listeria monocytogenes and Clostridium perfringens were obtained, but halloysite retained antimicrobial activity when comparing to films without nanofiller addition. Results from XRD showed that the addition of bacteriocins affected the crystallinity of starch matrix, whereas SEM images showed that peptides provoked surface irregularities. Adsorption approach proved to be a promise strategy to maintain a certain crystallinity and homogeneous morphology of films and consequently influencing other properties, like improving thermal performance. In the case of nanocomposite with nisin, adsorption procedure also improved water barrier properties. Increased mechanical resistance of films containing halloysite was observed. Elongation at break (EB) increased significantly for samples with nisin or pediocin, and those containing nisin plus halloysite. Physical interactions between additives and starch matrix via hydrogen bonding were evidenced by FTIR. Color parameters L*, a* and b* were close to those obtained for control films, although higher b* values were observed for pediocin samples. These results indicate the potential of such antimicrobial nanocomposite films as food packaging material. © 2016 Elsevier Ltd
Cava R.,Instituto Federal Sul rio grandense |
Dal Sasso Freitas C.M.,Federal University of Rio Grande do Sul |
Winckler M.,University Paul Sabatier
Proceedings of the ACM Symposium on Applied Computing | Year: 2017
Many computing applications imply dealing with network data, for example, social networks, communications and computing networks, epidemiological networks, among others. These applications are usually based on multivariate graphs, i.e., graphs in which nodes and edges have multiple attributes. Most of the visualization techniques described in the literature for dealing with multivariate graphs focus either on problems associated with the visualization of topology or on problems associated with the visualization of the nodes' attributes. The integration of these two components (topology and multiple attributes) in a single visualization is a challenge due to the necessity of simultaneously representing the connections and attributes, possibly generating overlapping elements. Among usual strategies to overcome this legibility problem we find filtering and aggregation, which make possible a simplified representation providing a general view with reduced size and lower density. However, this simplification may lead to a reduction of the amount of information being displayed, while in several applications the graph details still need to be represented in order to allow in-depth data analysis. In face of that, we propose ClusterVis, a visualization technique aiming at exploring nodes attributes pertaining to sub-graphs, which are either obtained from clustering algorithms or some user-defined criteria. The technique allows comparing attributes of nodes while keeping the representation of the relationships among them. The technique was implemented within a visualization framework and evaluated by potential users. Copyright 2017 ACM.
Winckler L.T.,Embrapa Clima Temperado |
Guths A.K.,Federal University of Pelotas |
Gayer P.R.,Instituto Federal Sul rio grandense
Pesquisa Agropecuaria Brasileira | Year: 2017
The objective of this work was to evaluate the ecosystem functions of a natural wetland and of artificially flooded rice areas, managed under organic and conventional systems, by phytomass degradation and by the colonization of this material by benthic macroinvertebrates. The experiment was carried out in a natural wetland area, and in two flooded rice areas managed under organic and conventional systems. Twenty-five decomposition bags filled with 10 g of dry vegetation were installed in each site. At 14, 28, 42, 56, and 70 days after the beginning of the experiment, five bags from each site were collected. Macroinvertebrates were identified and classified by functional trophic group. The number of species of benthic macroinvertebrates increased: natural wetland > organic system > conventional system. The Chironomidae group was present in all areas, confirming its food plasticity and adaptability to different substrates and environmental stress situations. The Amphipoda group was present only in the artificially flooded rice area, and the Acari, only in the natural wetland. The diversity of species in the natural wetland area was higher than in the artificially flooded rice area. Nutrient cycling, provided by phytomass decomposition, is affected by the management system, and the delay in this process causes a reduction of the ecosystem functions in the conventional system.
Hagemann S.E.,Instituto Federal Sul rio grandense |
Gastaldini M.C.C.,Federal University of Santa Maria
Revista Brasileira de Recursos Hidricos | Year: 2016
This study aimed to evaluate the quality of rainwater in the city of Santa Maria - RS, to assess the variation of some parameters during precipitation, and to identify the most appropriate uses for rainwater depending on the current standards for the use of rainwater and reuse water. Rainwater samples were collected directly from the atmosphere and a roof in order to analyze the changes in quality after passing the catchment surface. Each sampler was divided into five compartments to collect and store separately the first five millimeters of rain. The quality characteristics of rainwater were assessed using the following parameters: pH, conductivity, turbidity, BOD5, total solids, suspended solids, dissolved solids, and Escherichia coli. In some events iron, manganese, phosphate, ammonia and nitrate were also analyzed. It was observed that the quality of rainwater changed after its passage through the catchment. In raw state, rainwater can be used for non-potable purposes, it being recommended to discard at least the initial 2 mm. If treated, rainwater acquires a quality compatible with other uses, such as flushing toilets and washing vehicles. The behavior of some parameters was sensitive to changes in the precipitation characteristics, and there was a variation in the values related to the increase or decrease in the intensity of rainfall. © 2016, Brazilian Journal of Water Resources. All rights reserved.
Bacchieri G.,Instituto Federal Sul rio grandense |
Bacchieri G.,Federal University of Pelotas |
Barros A.J.D.,Federal University of Pelotas
Revista de Saude Publica | Year: 2011
The paper describes the situation of road traffic accidents in Brazil since 1998, when a new Brazilian traffic law was approved, up to the year 2010. A review of both academic and non-academic literature was carried out, including journals (both indexed and non-indexed), technical reports, author searches, searches in paper reference lists and direct contact with researchers. The main problems related to road traffic accidents in Brazil identified were the increase in the absolute number of deaths and in the mortality rates, a rapid increase in the number of motorcycles, and drink & driving. Influent authors in the field and centers of expertise were identified. Some potential solutions are presented by the authors, who suggest that the public offices related to traffic regulation and control are not taking suitable measures for control and reduction of road traffic accidents.
Bacchieri G.,Federal University of Pelotas |
Bacchieri G.,Instituto Federal Sul Rio Grandense |
Barros A.J.D.,Federal University of Pelotas |
Dos Santos J.V.,Federal University of Pelotas |
Gigante D.P.,Federal University of Pelotas
Accident Analysis and Prevention | Year: 2010
In 2006, we carried out a cross-sectional study in the urban area of Pelotas, Southern Brazil, with the aim of outlining the profile of bicycle commuters, analyzing their use of safety equipment and risk behaviors and the association between these variables and involvement in traffic accidents in the previous 12 months. This study was based on the baseline survey carried out prior to an educational intervention aimed at reducing accidents among cyclists. The sample included 1133 male subjects aged 20 years or more, and who used a bicycle for commuting. Crude and adjusted analyses were carried out using Poisson regression. We recorded a total of 152 reported traffic accidents in the 12 months preceding the interview, involving 10.8% of subjects. Most risk behaviors studied and the use of safety equipment showed no significant association with accidents. Only commuting by bicycle seven days per week, as opposed to five or six, and a combination of extremely imprudent behaviors such as zigzagging through traffic, riding after ingesting alcohol, and high-speed riding were found to be risk factors for accidents. Our findings suggest that in the context where the study was done (poor road signaling, limited policing, aggressive driving) changing cyclist behavior may not have substantial impact in terms of accident reduction before other road traffic interventions are implemented. © 2009 Elsevier Ltd.
Bregolin F.L.,Federal University of Rio Grande do Sul |
Sias U.S.,Instituto Federal Sul rio grandense |
Behar M.,Federal University of Rio Grande do Sul
Journal of Luminescence | Year: 2013
The present work deals with the photoluminescence (PL) emitted from Eu and Tb ions implanted at room temperature (RT) up to 350°C in a SiO2 matrix, followed by a further anneal process. The ions were implanted with energy of 100 keV and a fluence of 3×1015 ions/cm. Further anneals were performed in atmospheres of N2 or O2 with temperatures ranging from 500 up to 800°C. PL measurements were performed at RT and structural measurements were done via transmission electron microscopy (TEM). In addition, the Rutherford backscattering technique (RBS) was used to investigate the corresponding ion depth profiles. For Tb, the optimal implantation temperature was 200°C, and the anneal one was of 500°C. Under these conditions, the PL yield of the sharp band centered at 550 nm was significatively higher than the one obtained with RT implants. The PL spectra corresponding to the Eu ions show two bands, one narrow centered around 650 nm and a second broad one in the blue-green region. The implantation temperature plays a small influence on the PL shape and yield. However, the annealing atmosphere has a strong influence on it. Samples annealed in N2 present a broad PL band, ranging from 370 up to 840 nm. On the other hand, the O2 anneal conserves the original as-implanted spectrum, that is: a broad PL band in the blue-green region together with sharp PL band in the red one. For both ions, Tb and Eu, the TEM analyses indicate the formation of nanoclusters in the hot as-implanted samples. © 2012 Elsevier B.V.
Moreira D.M.,Federal University of Santa Catarina |
Moreira D.M.,Federal University of Espirito Santo |
Moraes A.C.,Instituto Federal Sul Rio Grandense |
Goulart A.G.,Federal University of Pampa |
Albuquerque T.T.D.A.,Federal University of Espirito Santo
Atmospheric Environment | Year: 2014
An integral solution of the atmospheric diffusion equation considering wind speed as a function of vertical height and eddy diffusivity as a function of both downwind distance from the source and vertical height is presented. The near-source dispersion problem is investigated comparing a vertical eddy diffusivity function of distance from the source against their asymptotic limit. The results suggest that the inclusion of the memory effect as modeled by Taylor's theory, improves the description of the turbulent transport process of atmospheric effluent released by a low continuous source in convective conditions. © 2013 Elsevier Ltd.
Galup-Montoro C.,Federal University of Santa Catarina |
Schneider M.C.,Federal University of Santa Catarina |
MacHado M.B.,Federal University of Santa Catarina |
MacHado M.B.,Instituto Federal Sul Rio Grandense
IEEE Transactions on Circuits and Systems II: Express Briefs | Year: 2012
This letter presents MOS analog circuits that can operate with very low supply voltages. Operation of the MOS transistor in the triode region is emphasized owing to the limited voltages available. Special attention has been given to the properties of the zero-VT transistor due to its high drive capability at low voltages. Simulation and measurement results for a Colpitts oscillator prototype set up around a zero-VT MOSFET demonstrated that the oscillator operates with supply voltages lower than the thermal voltage kT/q. Finally, ultra-low-voltage rectifiers using diodes or diode-connected MOSFETs operating in weak inversion are analyzed. © 2004-2012 IEEE.
Kremer M.M.,Instituto Federal Sul Rio Grandense |
Kremer M.M.,Federal University of Pelotas |
Reichert F.F.,Federal University of Pelotas |
Hallal P.C.,Federal University of Pelotas
Revista de Saude Publica | Year: 2012
Objective: To evaluate the intensity and duration of physical efforts in Physical Education classes in primary and secondary school. Methods: School-based cross-sectional study carried out by means of the observation of 218 Physical Education classes, including a total of 272 students (each one of the students was evaluated three times). The study was carried out in the city of Pelotas (Southern Brazil), between August and December 2009. In order to evaluate the intensity of the efforts, accelerometers were used and the following cut-off points were adopted (in counts per minute): sedentary activities (0-100), light activities (101-2,000), moderate (2,001-4,999), vigorous (5,000-7,999), and very vigorous activities (>8000). Results: The mean duration of the classes was 35.6 minutes (SD 6.0). The mean proportion of time spent in moderate to vigorous physical activity was 32.7% (SD 25.2). Boys (44.1%) were involved signifi cantly more in moderate to vigorous physical activity as compared to girls (21.0%; p<0.01). Students who practice physical activities outside the classes participated more in moderate to vigorous physical activity in the Physical Education classes. Conclusions: Besides the fact that Physical Education classes have a short duration, students practice moderate to vigorous physical activity during one third of the class, with a poor signifi cant contribution to students' level of physical activity.