450 research outputs found
Evaluación de la capacidad de auto-depuración de un arroyo urbano y el uso de macrófitas nativas como estrategia de restauración
Environmental degradation is one of the most serious problems in the metropolitan area of Buenos Aires, especially water pollution. The main aim of this work was to study mechanisms of self-purifying of a segment of San Francisco stream (located in Almirante Brown district), evaluating it in situ capacity of self-purifying downstream of a tubing and, in addition, by static bioassays in a greenhouse with native macrophytes. A stream section of 1500m was sampled twice during autumn 2013. The stream was generally hypoxic throughout the section (DO<2 mg/l), presenting low velocity (0.084 ± 0.008 m/s), moderate organic load (COD=72 ± 3 mg/l), high dissolved inorganic nitrogen (9.2 ± 0.9 mg/l) mostly as ammonium, and high levels of coliforms (7600 ± 700 cfu/ml). There was no increase in the dissolved oxigen and no decrese in the nutrients and COD along the section, suggesting that the self-purifying process for this parameters, along this section and this time of this year was negligible. Almost complete removal of ammonium (90-95%) and nitrites was observed in the bioassays. Based on our results, the present condition of the stream may be modified by increasing water oxygenation and macrophytes biomass, among others strategies. It is planned to incorporate the analysis of seasonal effects and complementary bioassays with macrophytes minimizing the algal growth.Facultad de Ciencias Naturales y Muse
Evaluación de la capacidad de auto-depuración de un arroyo urbano y el uso de macrófitas nativas como estrategia de restauración
Environmental degradation is one of the most serious problems in the metropolitan area of Buenos Aires, especially water pollution. The main aim of this work was to study mechanisms of self-purifying of a segment of San Francisco stream (located in Almirante Brown district), evaluating it in situ capacity of self-purifying downstream of a tubing and, in addition, by static bioassays in a greenhouse with native macrophytes. A stream section of 1500m was sampled twice during autumn 2013. The stream was generally hypoxic throughout the section (DO<2 mg/l), presenting low velocity (0.084 ± 0.008 m/s), moderate organic load (COD=72 ± 3 mg/l), high dissolved inorganic nitrogen (9.2 ± 0.9 mg/l) mostly as ammonium, and high levels of coliforms (7600 ± 700 cfu/ml). There was no increase in the dissolved oxigen and no decrese in the nutrients and COD along the section, suggesting that the self-purifying process for this parameters, along this section and this time of this year was negligible. Almost complete removal of ammonium (90-95%) and nitrites was observed in the bioassays. Based on our results, the present condition of the stream may be modified by increasing water oxygenation and macrophytes biomass, among others strategies. It is planned to incorporate the analysis of seasonal effects and complementary bioassays with macrophytes minimizing the algal growth.Facultad de Ciencias Naturales y Muse
Interacción del herbicida Picloram con minerales arcillosos naturales y minerales arcillosos pilareados
El drenaje y la velocidad de permeación de los plaguicidas a través de los suelos después de ser dispersados, dependen de la interacción de los mismos con los componentes del suelo, lo que determina la contaminación de las aguas subterráneas y/o superficiales.
El herbicida picloram (PCM) es usado ampliamente para eliminar malezas en sembradíos de trigo, y plantas leñosas en países como Chile, Brasil, Australia y Argentina. El PCM se encuentra en su forma aniónica (deprotonado) a los valores de pH de la mayoría de los suelos (pKₐ ≈ 2,3), por lo que su movilidad es muy alta.
Los minerales de arcilla pilareados (PILCs) resultan interesantes para ser utilizados como adsorbentes para la remoción de contaminantes y formulados de liberación lenta, debido a sus múltiples centros cargados, amplia superficie, gran espacio interlaminar y estabilidad térmica.
En este sentido se estudió la interacción del PCM con minerales arcillosos naturales del tipo montmorillonita, illita, nontronita y caolinita así como también con PILCs basados en una montmorillonita pilareada con óxidos de hierro.Centro de Tecnología de Recursos Minerales y Cerámic
Minerales arcillosos pilareados con óxidos de hierro y aluminio como formulados de liberación lenta del herbicida Picloram
Generalmente, los plaguicidas se pulverizan como partículas muy finas suspendidas en medios acuosos, en presencia de surfactantes ó disueltos en compuestos orgánicos formando emulsiones con agua. La velocidad de permeación a través de los suelos y el drenaje de los plaguicidas es determinante en la contaminación de las aguas subterráneas y/o superficiales.
Los minerales de arcilla pilareados (PILCs) resultan interesantes para ser utilizados como catalizadores, adsorbentes para la remoción de contaminantes y formulados de liberación lenta, debido a sus múltiples centros cargados, amplia superficie, gran espacio interlaminar y estabilidad térmica.
En este trabajo se realiza un estudio de los procesos de adsorción del herbicida Picloram (PCM) sobre PILCs y se evalúa su utilización para la preparación de formulados de liberación lenta del herbicida.
En este sentido, se sintetizaron PILCs a partir de la incorporación de óxidos mixtos de hierro y aluminio a la estructura de un mineral arcilloso del tipo montmorillonita.
La relación Fe/Al en la solución pilareante se varió con la finalidad de estudiar la relación de la adsorción de PCM con el contenido de hierro en la estructura de la PILC.Centro de Tecnología de Recursos Minerales y Cerámic
Estudo dos solos do município de Hulha Negra-RS.
bitstream/item/41231/1/Hulha-negra.pdf; bitstream/item/41232/1/mapa-capacidade-de-uso.pdf; bitstream/item/41233/1/mapa-formas-de-relevo.pdf; bitstream/item/41234/1/mapa-solos.pd
Genetic variability of high molecular weight glutenin subunits in bread wheat from continental Portugal, Madeira and Canary Islands
The genetic variability of high molecular
weight glutenin subunits (HMWGS) composition at
the Glu-1 loci in bread wheat (Triticum aestivum L.)
was studied electrophoretically using the SDS–PAGE
in 3,470 individuals representing 159 populations
originated from the Canary Islands (Spain), the
Archipelago of Madeira (Portugal) and the continental
Portugal. A total of 25 alleles were detected, resulting
in 69 different allele combinations. The geographical
distribution of the high molecular weight glutenin
alleles confirms historical data regarding circulation of wheat germplasm between the Iberian Peninsula and
Madeira and between Madeira and the Canary Islands
and vice versa.This research was supported by the
European Community through the project AGRICOMAC and
GERMOBANCO INTERREG III-B. We thank to Bank of
Germplasm INIA (CRF, Alcala´ de Henares, Spain), to Maria
Teresa Carvalho e Vasconcelos from Instituto Superior de
Agronomia (Lisbon) and the National Small Grain Collection
(Aberdeen, USA) for supplying the wheat accessions.info:eu-repo/semantics/publishedVersio
Environmental Implications of pH in a Pervious Concrete Pavement on Highway BR-319, Amazonas, Brazil
http://sherpa.ac.uk/romeo/issn/0973-4929/This research studies the carbonation phenomenon of cement due to the reaction of its components with water. In this chemical reaction occurs the formation of calcium carbonate and the absorption of CO2 in the atmosphere, which contributes to the reduction of the Greenhouse Effect. However, carbonation also causes pathologies such as efflorescence, staining and corrosion of steel in concrete. This research shows the results of experiments with specimens of concrete permeable, made with cement and big aggregates (calcareous stone) in the ratio of 1: 4.4 (cement:stone) and a factor of 0.3 for water / cement. The specimens were kept in contact with water containing different amounts of CO2 - distilled, ionized alkaline, carbonated, and tap water. After the experiments were carried out, an increase in pH, a mean compressive strength of 12.3 MPa and a permeability rate of 1.28 l / h was observed. The results show that the permeable concrete did not present any pathologies resulting from the carbonation during the period of the research, which recommended the same for use in road pavements.info:eu-repo/semantics/publishedVersio
Desenvolvimento e avaliações físico-química e sensorial de bebida láctea saborizada de cenoura e laranja com o soro do leite de búfala.
Esta pesquisa foi realizada para avaliar o desenvolvimento, as características físico-químicas e sensoriais de bebida láctea com cenoura sabor de laranja, utilizando soro de leite de búfala, no Laboratório do Centro de Ciências Naturais e Tecnologia da Universidade do Estado do Pará, com base de soro de leite de búfalo, do rebanho da Embrapa Amazônia Oriental , Belém, Estado do Pará, Brasil. Inicialmente, a calda é feita com cenoura, suco de laranja, sacarose e água, que foi misturada a 45 º C, e, subsequentemente, empacotado e refrigerado. Em seguida, foram realizadas análises físico-química e sensorial. Análise sensorial confirmou a aceitabilidade do produto, com ênfase sobre o sabor e aparência global
Perfil sensorial do requeijão cremoso condimentado elaborado com leite de búfala, em Belém, Pará.
Este trabalho visa elaborar três formulações de requeijão cremoso condimentado, com leite de búfala: A ? orégano; B ? manjericão; e C - pimenta calabresa, com intuito de adicionar novos sabores ao derivado e caracterizá-los sensorialmente. Os derivados foram elaborados a partir da massa dessorada, obtida pela acidificação do leite de búfala, com adição de manjericão, orégano e pimenta calabresa, 0,7% em cada formulação. Foi realizado o teste de aceitação com 60 julgadores, dentre os quais, 53,8% do sexo feminino e 46,2% do masculino, entre os quais 87,2% com idade entre 16 e 25 anos e 35,9% raramente consumiam o derivado. Na interação Sexo vs. Idade vs. Na intenção de compra, 79,5% dos provadores comprariam requeijão cremoso de leite de búfala condimentado e 20,5% não comprariam. O derivado A foi diferente de B e C (p<0,05), nos atributos aroma, sabor e avaliação global. No derivado B foi observada diferença estatística (p<0,05) entre sabor, aparência e avaliação global, enquanto que a amostra C diferiu apenas no atributo aparência. Nos atributos avaliados, as notas estiveram entre "gostei ligeiramente" e "gostei muito", com base na escala hedônica de nove pontos, o que indica boa aceitação e viabilidade para inovar a cadeia produtiva de derivados de leite búfala
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