Hidrocarbonetos e esterois como indicadores de fontes e destino de matéria orgânica em sedimentos da Baía de Sepetiba, Rio de Janeiro

The inputs of organic matter derived from natural and anthropogenic sources to Sepetiba Bay were investigated by using aliphatic hydrocarbons and sterols in superficial sediments. Concentrations ranged from 0.26 to 2.65 μg g-1, <0.01 to 17.41 μg g-1 and 0.77 and 9.24 μg g-1 for n-alkanes, UCM (unresolved complex mixture) and total sterols, respectively. The selected markers and ratios among individual compounds showed the major contribution of terrestrial sources to the total pool of sedimentary organic matter in the bay, but the accumulation of autochthonous organic matter increased with distance from the shoreline. The input of petroleum hydrocarbons and sewage (coprostanol in the range 0.01 to 0.43 μg g-1) were also detected, especially in the more urbanized regions of the bay, but at lower levels of contamination when compared to estuaries in other Brazilian coastal regions.

Transferência trófica de mercúrio e selênio na costa norte do Rio de Janeiro

Trophic transfer of trace elements along marine food chains has been recognized as an important process influencing metal and metalloid bioaccumulation. The trophic transfer of mercury was observed between trophic levels from prey (considering fish with different feeding habits and squid) to top predator (dolphin) in a Northern coastal food chain of Rio de Janeiro. Selenium showed some evidence of trophic transfer between lower trophic levels. Dolphin presented the highest mercury concentrations whereas the benthic carnivorous fish showed the highest selenium concentrations. Mercury is biomagnified through the food chain while selenium does not present the same behavior.

O Instituto de Química da Universidade Federal do Rio de Janeiro, da pós-graduação à incorporação dos cursos de graduação: uma perspectiva histórica

This work intends to present the history of top-level Chemistry education in Rio de Janeiro. It's important to rescue the history of Chemistry Institute of Federal University of Rio de Janeiro since 1959. It's also important to understand the incorporation of two undergraduate courses: Chemistry and Chemistry bachelor's degree. It covers historical background of Chemistry education in old National Faculty of Philosophy, considering power disputes between Industrial Chemistry Course and Chemical Engineering; when and in which circumstances the Institute was created; political context and its relation with postgraduate. Finally, discuss the incorporation of undergraduate courses and curriculum modifications since 1968.

Teores de compostos orgânicos em cachaças produzidas na região norte fluminense - Rio de Janeiro

This work aimed to quantify some organic compounds in "cachaças" (sugar cane spirit). The ethyl alcohol was quantified by densimetry, after distillation. The acetic acid, methyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, isoamyl alcohol (mixture of 2-methyl-butyl and 3-methyl-butyl), ethyl acetate and acetaldehyde were determined by gas chromatography; and the furfural, 5-hydroxy-methylfurfural and acrolein by high efficiency liquid chromatography. From the 30 samples analyzed, 63.3% showed non-conformity with national legislation regarding at least one of the analyzed components.

Distribuição de Hg total e suas associações com diferentes suportes geoquímicos em sedimentos marinhos da margem continental brasileira: Bacia de Campos - Rio de Janeiro

Mercury distribution and geochemical support on the Continental Margin was evaluated at the Campos Basin, Rio de Janeiro state, Brazil. The average concentrations for all analyzed elements were, respectively, 20 ± 5 ng g-1 (Hg); 30 ± 14 mg g-1 (Al); 16 ± 6 mg g-1 (Fe), and 254 ± 83 µg g-1 (Mn). Silt and clay content, total carbonate and Hg, and organic carbon increased with depth. Finally, the relationship between Hg and silt clay showed significant positive correlation. Total Hg concentrations are the background level described primarily (~40 ng g-1).

Bioconcentração e biomagnificação de metilmercúrio na baía de Guanabara, Rio de Janeiro

Methylmercury was determined in water and aquatic biota from Guanabara Bay. Trophic transfer of methylmercury was observed between trophic levels from prey (microplankton, mesoplankton and fish with different feeding habits) to top predator (pelagic demersal fish). Top predator fish presented the highest methylmercury concentrations (320.3 ± 150.7 mg kg-1 dry wt.), whereas microplankton presented the lowest (8.9 ± 3.3 mg kg-1 dry wt.). The successive amplification of methylmercury concentrations and its bioconcentration factor with increasing trophic levels from base to top indicate that biomagnification may be occurring along the food web. Results suggest the importance of feeding habits and trophic level in the bioaccumulation of methylmercury by aquatic biota.

Concepções sobre currículo de formadores de professores: o curso de licenciatura em Química do Instituto de Química da Universidade Federal do Rio de Janeiro

In this paper, we discussed the conceptions of curriculum of teachers' trainers from de course of Chemistry from de Chemistry Institute and from the Education School of the Federal University of Rio de Janeiro. We understand that the curriculum results from a social construction, so, we intent to comprehend how happen the constitution of the course's curriculum, based on documents and interviews with the subjects of the research. The study showed that there were competitions for status, resources and territories between the Chemistry Institute and the Education School when the course was created, as well as there were internal competitions in the creation of the disciplines depending on the department of origin of the teachers.

Chlorophenols in tap water from wells and surface sources in Rio de Janeiro, Brazil: method validation and analysis

Two analytical methods were validated for determination of trichlorophenols, tetrachlorophenols and pentachlorophenol in drinking water. Limits of quantification were at least ten times lower than maximum permissible levels set by the Brazilian legislation, which are 200 ng mL-1 for 2,4,6-trichlorophenol and 9 ng mL-1 for pentachlorophenol. Chlorophenol levels were determined in tap water collected in the Municipality of Rio de Janeiro. 2,4,6-Trichlorophenol residues were detected in 36% of the samples, varying from 0.008 to 0.238 ng mL-1. All other analytes were below the limit of quantification. The validated methods showed to be suitable for application in routine quality control.

Fluxos de óxido nitroso em solos com cobertura de Floresta Ombrófila Densa Montana na Serra dos Órgãos, Rio de Janeiro

Soil fluxes of N2O were determined over one year in montane tropical rainforest of southeastern Brazil with average annual rainfall of 2.8 m. Annual mean (± standard deviation) and median N2O fluxes were 3.0 ± 1.4 and 2.7 µg N m-2 h-1, respectively, is 5-10 times lower than mean values reported in literature for tropical rainforest soils in the Amazon basin. N2O fluxes varied spatially and seasonally, were about twice as high during summer as in winter, and significantly influenced by both monthly precipitation and soil temperature.

Impacto ambiental de kartódromos situados na cidade do Rio de Janeiro: monitoramento de BTEX no ar e do nível de ruído

In this work, noise and aromatic hydrocarbons levels of indoor and outdoor karting circuits located in Rio de Janeiro were assessed. The sampling was perfomed using active charcoal cartridges, followed by solvent desorption and analysis by gas chromatography with mass spectrometry detection. This study demonstrated that the karting circuits, venues for entertainment, were a major source of air pollution with the detection of considerable amounts of these compounds (2.0 to 19.7 µg m-3 of benzene; 4.1 to 41.1 µg m-3 of toluene; 2.8 to 36.2 µg m-3 of ethylbenzene; 0.7 to 36.2 µg m-3 of xylenes) and high noise levels.

Orange rust in sugarcane: molecular identification in Rio de Janeiro State

Sugarcane (Saccharum spp.) cultivation is one of the major agricultural activities in the Brazilian states. This study aimed to molecularly identify the pathogen associated with rust in sugarcane cultivars in the state of Rio de Janeiro and to suggest a control strategy. Among the 14 PCR-tested cultivars, Puccinia kuehnii infection was identified for RB947520, RB92606, RB835486, RB72454, SP89-11I5, SP83-2847, both from infected leaf sample and from urediniospores. Puccinia kuehnii was not detected by PCR for the cultivars RB955971, RB951541, RB92579, RB867515, RB855536, SP91-1049, SP80-3280, SP80-1816. This is the first molecular detection of this fungus in the state of Rio de Janeiro for six of the 14 analyzed cultivars.

Influence of pioneer-species combinations on restoration of disturbed ecosystems in the Atlantic Forest, Rio de Janeiro, Brazil

The analysis of species composition and its effects on sustainability restoration processes in the Atlantic Forest with poor environmental attributes is important to improve rehabilitation techniques for disturbed ecosystems. Reforestation projects were used as Biological Measures (BM) of rehabilitation, where treatments differ in the composition of exotic species, utilized as anthropic pioneers: BM1 - 82% (73% Mimosa caesalpiniifolia Benth, 9% Eucalyptus citriodora Hook.); BM2 - 91% (9%, 82%); and BM3 - 25% (15%, 10%). The monitoring of spontaneous regeneration was evaluated in three 12-year-old reforestation sites between thr rainy season of 2004 and 2005, and compared with an approximately 100-year-old native forest fragment and a grassland: ecosystems with inertial tendency toward recuperation and degradation, respectively. It was detected that exotic species used as anthropic pioneers strongly influenced regeneration: BM1 (75%), BM2 (85%), BM3 (55%), Forest (0%) and Grassland (50%). The highest similarity of species with forest regeneration (5%) was found for treatment BM3.

Morfometria de microbacias do Córrego Rico, afluente do Rio Mogi-Guaçu, Estado de São Paulo, Brasil

Este trabalho teve como objetivo avaliar as características morfométricas das microbacias (2ª, 3ª, 4ª e 5ª ordens de magnitude) da bacia hidrográfica do córrego Rico, sub-bacia do Rio Mogi-Guaçu, localizada na região administrativa de Ribeirão Preto, Estado de São Paulo, Brasil. Para tanto, foram determinados os parâmetros físicos e a configuração topográfica natural do sistema de drenagem. Os procedimentos para a obtenção dos dados foram fundamentados em técnicas de sensoriamento remoto e geoprocessamento. A partir da vetorização das cartas topográficas correspondentes à área de estudo, realizou-se a análise morfométrica quanto às características dimensionais, do padrão de drenagem e do relevo no sistema de informação geográfica ArcView. A microbacia é considerada de sexta ordem de magnitude, com área estimada de 542 km², com 85 microbacias de segunda ordem, 22 de terceira, sete de quarta ordem e duas de quinta. Utilizando o critério geométrico, na disposição fluvial das sub-bacias de cabeceiras observou-se a predominância dos modelos dendríticos e subdendríticos, enquanto a jusante predominava o modelo subparalelo, respectivamente, nas áreas de ocorrências dos arenitos Bauru e rochas efusivas básicas.

Heterogeneidade florística das fitocenoses de restingas nos estados do Rio de Janeiro e Espírito Santo, Brasil

Esta pesquisa teve como objetivo comparar florísticamente as formações vegetacionais que compõe o ecossistema Restinga dos Estados do Rio de Janeiro e Espírito Santo. Para isto foi realizado uma compilação de dados de levantamentos florísticos e fitossociológicos, sendo utilizado para esta análise o índice de similaridade de Jaccard, onde as interpretações se deram pela média de grupo (UPGMA). As 11 formações analisadas apresentaram uma riqueza total de 990 espécies, distribuídas em 141 famílias, sendo Fabaceae (73), Myrtaceae (59), Rubiaceae (48), Orchidaceae (44), Cyperaceae (38), Poaceae (36), Bromeliaceae (35), Euphorbiaceae (30), Asteraceae (30) as de maior riqueza. A similaridade entre as formações foi baixa, sendo o maior valor de 33%. Os resultados obtidos denotam uma alta heterogeneidade florística existente nas formações que compõe o ecossistema Restinga nos dois Estados analisados, sendo esta determinada por diferentes fatores que atuam em cada fitocenose.

Morfologia e aspectos hidrológicos da bacia hidrográfica do rio Preto, divisa dos estados do Rio de Janeiro e de Minas Gerais

Neste trabalho, determinaram-se as características morfométricas do relevo e da rede de drenagem da Bacia Hidrográfica do Rio Preto, com a finalidade de prever do comportamento hidrológico da área. A partir da delimitação da área da bacia, da digitalização das curvas de nível e do sistema de drenagem, foram obtidas características geométricas do relevo e da hidrografia da BHRP e das suas seis sub-bacias. Concluiu-se que a área apresentava forma alongada e estreita, aliada a uma alta densidade de drenagem, evidenciando menor possibilidade de ocorrência de cheias. Porém, foram observadas enchentes justificadas pelos solos rasos, pelos intensos processos de desmatamento e uso da terra e pelo relevo acidentado, sendo 73,1% da área caracterizada como de relevo forte-ondulado a montanhoso. Quanto às sub-bacias, verificou-se que em todas essas unidades menos de 28% da área era compreendida de relevo plano, facilitando a erosão hídrica.