538 research outputs found
Slurry sampling for Hg determination in sediments, sewage sludge and coal samples by cold vapor atomic absorption spectrometry
Estado de exceção e as ações diretas em busca da democracia : uma análise dos novos movimentos reivindicatórios diante dos megaeventos
O artigo Estado de Exceção e as ações diretas em busca da democracia : uma análise dos novos movimentos reivindicatórios diante dos megaeventos, analisa a atuação das instituições políticas e jurídicas no contexto dos preparativos para o megaevento Copa do Mundo, bem como os protestos e movimentos sociais emergentes no cenário brasileiro desde junho de 2013, tendo como marco inicial ações contra o aumento das passagens, com manifestações e ocupações convocadas pela internet sem uma coordenação previamente definida. As mobilizações de 2013 apontaram traços semelhantes aos processos vividos pelos novíssimos movimentos sociais destacados por diversos autores como a Primavera Árabe, os movimentos de ocupação de praças na Europa e Estados Unidos da América. Foram mobilizações que pelo seu caráter massivo e criativo com ações no campo cultural, apontaram promessas de construção de novos meios de participação política em desafio aos modelos tradicionais. No entanto, a resposta do Estado foi dada pela supressão das garantias e direitos fundamentais trazidos na Constituição, impondo uma política de controle social profundamente repressiva, com prisões e detenções arbitrárias, abusos de poder dos integrantes dos órgãos de segurança, com aprovação de legislações de conteúdo de exceção e um sistema judicial atento em legitimar tais arbítrios.SUMÁRIO
1. Introdução
2. A novidade de movimentos populares no Brasil entre o fim da década de 1970 e início da década de 1980
3. A emergência de movimentos antissistêmicos no contexto internacional, os novos e os novíssimos movimentos sociais na era da globalização neoliberal
4. Os protestos no Brasil: a construção do cenário
5. Vozes das ruas: Os protestos sociais iniciados em junho de 2013 no Rio de Janeiro e as ações colectivas diretas
6. Os velhos e (não tão) novos inimigos do Estado: a criminalização dos protestos sociais
7. Estado de exceção e a desordem constitucional
8. Sistema judicial inquisidor e o banco dos réus: Análise de casos emblemáticos
a) Caso Rafael Braga Vieira
b) Os 23 réus das jornadas de junho de 2013 (Processo penal nº 0229018-262013.8.19.0001 em trâmite na 27ª Vara Criminal)
8. Contra hegemonia no campo jurídico: estratégias alternativas em defesa dos protestos sociais
9. Considerações finais
Referências bibliográfica
Acid decomposition of yerba mate (ilex paraguariensis) using a reflux system for the evaluation of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb and Zn contents by atomic spectrometric techniques
In the first part of this paper, two acid decomposition procedures for the determination of Al, Ca, Fe, Mg, Mn and Zn contents in yerba mate samples by inductively coupled plasma optical emission spectrometry (ICP OES) were compared. Using a reflux system, the samples were treated with a mixture of HNO3 and H2O2 for 3 hours at 220 °C in the digester block. The results from five commercial yerba mate samples were compared with the results obtained from microwave digestion. Good agreement between the procedures at a 95% confidence level was obtained with relative standard deviation (RSD) values lower than 10.0%. The accuracy was evaluated using addition and recovery experiments (80.5 to 112.8%). In the second part, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Pb and Zn concentrations were evaluated in the yerba mate infusion. The results showed that elements such as Na, K, Mg and Zn are easily transferred to the hot water used for the infusion. For Pb and Cd, the concentrations found in the analyzed samples were lower than the values established by Brazilian legislation274685693CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO GRANDE DO SUL - FAPERGSSem informação552197/2011-4Sem informaçã
Endophytic Fungi of Tropical Forests: A Promising Source of Bioactive Prototype Molecules for the Treatment of Neglected Diseases
Determination of Na, K, Mg and Ca in biodiesel by LS F AAS and HR-CS F AAS: studies that supported the proposal of the ABNT NBR 15556 norm
Physicochemical properties and cell viability of shrimp chitosan films as affected by film casting solvents. I-potential use as wound dressing
: Chitosan solubility in aqueous organic acids has been widely investigated. However, most of
the previous works have been done with plasticized chitosan films and using acetic acid as the
film casting solvent. In addition, the properties of these films varied among studies, since they are
influenced by different factors such as the chitin source used to produce chitosan, the processing
variables involved in the conversion of chitin into chitosan, chitosan properties, types of acids used to
dissolve chitosan, types and amounts of plasticizers and the film preparation method. Therefore,
this work aimed to prepare chitosan films by the solvent casting method, using chitosan derived
from Litopenaeus vannamei shrimp shell waste, and five different organic acids (acetic, lactic, maleic,
tartaric, and citric acids) without plasticizer, in order to evaluate the effect of organic acid type
and chitosan source on physicochemical properties, degradation and cytotoxicity of these chitosan
films. The goal was to select the best suited casting solvent to develop wound dressing from shrimp
chitosan films. Shrimp chitosan films were analyzed in terms of their qualitative assessment, thickness,
water vapor permeability (WVP), water vapor transmission rate (WVTR), wettability, tensile properties,
degradation in phosphate buffered saline (PBS) and cytotoxicity towards human fibroblasts using
the resazurin reduction method. Regardless of the acid type employed in film preparation, all films
were transparent and slightly yellowish, presented homogeneous surfaces, and the thickness was
compatible with the epidermis thickness. However, only the ones prepared with maleic acid presented
adequate characteristics of WVP, WVTR, wettability, degradability, cytotoxicity and good tensile
properties for future application as a wound dressing material. The findings of this study contributed
not only to select the best suited casting solvent to develop chitosan films for wound dressing but
also to normalize a solubilization protocol for chitosan, derived from Litopenaeus vannamei shrimp
shell waste, which can be used in the pharmaceutical industry.info:eu-repo/semantics/publishedVersio
TiO2 nanostructured films for electrochromic paper based-devices
(H2020-NMP-2015, grant 685758-21D
H2020 ERC AdG 787410)Electrochromic titanium dioxide (TiO2) nanostructured films were grown on gold coated papers using a microwave-assisted hydrothermal method at low temperature (80 °C). Uniform nanostructured films fully covered the paper substrate, while maintaining its flexibility. Three acids, i.e., acetic, hydrochloric and nitric acids, were tested during syntheses, which determined the final structure of the produced films, and consequently their electrochromic behavior. The structural characteristics of nanostructured films were correlated with electrochemical response and reflectance modulation when immersed in 1 M LiClO4-PC (lithium perchlorate with propylene carbonate) electrolyte, nevertheless the material synthesized with nitric acid resulted in highly porous anatase films with enhanced electrochromic performance. The TiO2 films revealed a notable contrast behavior, reaching for the nitric-based film optical modulations of 57%, 9% and 22% between colored and bleached states, at 250, 550 and 850 nm, respectively in reflectance mode. High cycling stability was also obtained performing up to 1500 cycles without significant loss of the electrochromic behavior for the nitric acid material. The approach developed in this work proves the high stability and durability of such devices, together with the use of paper as substrate that aggregates the environmentally friendly, lightweight, flexibility and recyclability characters of the substrate to the microwave synthesis features, i.e., simplicity, celerity and enhanced efficiency/cost balance.publishersversionpublishe
Transportation assessment in simulated curved canals after preparation with twisted file adaptive and bt-race instruments
This study compared the incidence of deviation along curved canals after preparation with two nickel-titanium (NiTi) rotary systems, Twisted File Adaptive and BT-RaCe. Forty resin training blocks with curved canals were filled with ink and divided into two groups according to the instrumentation technique. Preinstrumentation images were acquired by using a stereomicroscope. The canals were up to an instrument #35/0.04. Postinstrumentation images were captured using the same conditions, and the images were superimposed. The amount of resin removed was measured at 8 different points, beginning at the apical terminus of the canal. Differences in the mesial and distal aspects were measured to evaluate the occurrence of deviation. The Student?s-t test was used for comparison of the intragroup deviation. Intergroup analysis was performed by using one-way ANOVA for each level. For multiple comparisons, the Bonferroni test was used and a cutoff for significance was set at 5%. Intragroup analysis showed that both instrumentation techniques promoted some deviation at all levels. BT-RaCe showed significantly lower deviation at 0 and 4-mm levels than Group Twisted File Adaptive (p<0.05). On the other hand BT-RaCe showed worse performance at level 6. The results of this study demonstrated that none of the NiTi tested systems was able to instrument curved canals simulated in resin blocks without some deviation during the preparation. There is still need for improvement in the instruments manufacturing aiming the better performance of endodontic files in curved root canals
Determination of Hg and Se in biological materials by chemical vapor generation electrothermal vaporization inductively coupled plasma mass spectrometry using isotope dilution calibration after microwave-assisted digestion with Aqua Regia
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