Caracterización de morteros de yeso reforzados con fibras recuperadas de eslingas textiles de un solo uso.

Este trabajo estudia el comportamiento de conglomerantes a base de yeso agregados con Residuos de Construcción y demolición (RCD) como fibras recuperadas de eslingas textiles de un solo uso, incorporadas en tres porcentajes y comparando con una muestra de referencia.Las eslingas textiles de un solo uso, tienen como origen, dos obras situadas en la Comunidad de Madrid (Centro de Neurociencias Ramón y Cajal) y la Comunidad de Castilla la Mancha (Nuevo Hospital de Cuenca). Han sido estudiadas las propiedades de las eslingas y se han realizado ensayos de laboratorio para investigar el comportamiento de las probetas estudiadas con un porcentaje de 5%, 7,5%, 10%, de fibras agregadas a la matriz de morteros de conglomerantes a base de yeso. Los resultados demuestran que el comportamiento de las probetas con agregados de fibras con origen de eslingas textiles de un solo uso, tienen un mejor comportamiento en general que aquellas probetas con agregados de fibra comercial referente a las resistencias mecánicas obtenidas de los ensayos realizados.

Determinação da composição química de quatro variedades de feijão caupi (Vigna unguiculata L. Walp) cultivadas em solo potiguar

The cowpea (Vigna unguiculata L. Walp) is a major food crops in northeastern Brazil. In Rio Grande do Norte, the cowpea, vigna beans or cowpea, as it is known, has great socioeconomic importance as a source of nutrients in food, with great emphasis among agricultural products. To improve productivity and resistance to pests, two cultivars were developed exclusively by EMPARN (Agricultural Research Corporation of Rio Grande do Norte), for breeding. The samples were provided by EMPARN, two improved (Potiguar and Laugh year) and two landraces (Rib of beef and Canapu). The seeds were ground and made into flour samples and the determination of moisture and ash by graviméticos methods, lipids by Soxhlet extraction, fibers with determiner fiber, carbohydrates by difference and minerals by ICP-OES were performed except the match analyzed by UVvis. The results showed a high fiber content (55.55% and 55.32% and 50.04% improved samples and 50.32% creole samples) and protein (25.52% and 25.27% improved and 27 samples, 23% and 24.99% creole samples). Comparing the results of the mineral content, the improved cultivars stood out in relation to Ca, Co, P, Mg, Mo and Na. Creole cultivars showed better results for Cu, Cr (low), Fe, Mn, Ni, K and Zn. The results will be important in future nutritional research and to build a table of Brazilian chemical composition of foods.

Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina

ANDRADE JR., T. E. et al. Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina. Cerâmica, v.51, n.317, p.37-41.ISSN 0366-6913. Disponível em:://www.scielo.br/scielo.php?pid=S0366-69132005000100008&script=sci_abstract&tlng=pt>. Acesso em: 06 out. 2010.

Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina

ANDRADE JR., T. E. et al. Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina. Cerâmica, v.51, n.317, p.37-41.ISSN 0366-6913. Disponível em:://www.scielo.br/scielo.php?pid=S0366-69132005000100008&script=sci_abstract&tlng=pt>. Acesso em: 06 out. 2010.

Resistência do solo à penetração e ao cisalhamento em diversos usos do solo em áreas de preservação permanente

The soil resistance to penetration and shear can be used as indicators of soil compaction and to indicate the susceptibility of a soil to erosion. The objective of this study was to quantify and compare the impact provided by different land uses in a haplic cambissol in areas of permanent preservation, from the soil resistance to penetration and shear. The experimental area was located in an area of permanent preservation, the sub-basin of the Ribeira Iguape River - SP, with different land uses: banana cultivation - CBAN, degraded pasture - PDEG, silvopastoral system - MPIS and native forest - MNAT. The test for resistance to penetration was accomplished with a digital penetrometer compaction of manual effort, to a depth of 40 cm. The soil shear strength was determined by Vane Test at a depth between 0 and 5 cm. The degraded pasture was similar to native forest, with less resistance to penetration. The banana cultivation and silvopastoral system were the land uses with the highest resistance to penetration, bringing serious risk of erosion in areas of permanent preservation. The soil under native forest had lower shear strength. The cultivation of bananas, degraded pasture and silvopastoral system were the land uses with higher shear strength of soil, indicating that the use of these soils in areas of permanent preservation is promoting the same compression.

Descrição do resistoma de solo de Cerrado stricto sensu e o potencial de dioxigenases metagenômicas na resistência antimicrobiana e em processos de biorremediação

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2016.

Suplementação do solo com lodo de esgoto: efeito de aplicações frequentes e residual na produtividade do milho.

RESUMO: Neste trabalho foi avaliada a dinâmica do N mineral e a produtividade do milho em solo que vem, a longo tempo, recebendo aplicações de lodos de esgoto provenientes das estações de Tratamento de Franca e de Barueri, ou que recebeu lodo de esgoto por certo período de tempo. As aplicações iniciaram-se em 1999 a taxas que variaram na dose recomendada, tomando-se como base os requerimentos da planta em N, até uma taxa 8 vezes maior. Nos anos de 2004 e 2005 os lodos não foram aplicados. Em 2006 e 2007 somente foi aplicado o lodo de Franca. Os resultados deste trabalho referem-se às coletas de solo feitas no ano agrícola 2007/2008. Os tratamentos com lodo foram comparados com o tratamento com fertilização mineral (FM) e com o tratamento testemunha (T), que não recebeu fertilizantes e nem lodo. Os teores de N no solo aumentaram com as doses do lodo de Franca, o que não ocorreu com o lodo de Barueri. As produtividades do milho foram maiores nos tratamentos com o lodo de Franca e não diferiram com as doses aplicadas. Nos tratamentos com o lodo de Barueri as produtividades foram menores que as obtidas com o lodo de Franca, mas foram semelhantes às obtidas no tratamento com FM. A menor produtividade foi obtida no tratamento T. Os maiores teores de N totais nos grãos foram obtidos nos tratamentos com o lodo de Franca sem diferença entre as doses.

Produção de fibras de alumina biomórfica a partir do sisal

Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte. Consequently, sisal has played a strategic role in the economy of the region, as one of few options of income available in the semi-arid. Find new options and adding value to products manufactured from sisal are goals that contribute not only to the scientific and technological development of the Northeastern region, but also to the increase of the family income for people that live in the semi-arid areas where sisal is grown. Lignocellulosic fibers are extracted from sisal and commonly used to produce both handcrafted and industrial goods including ropes, mats and carpets. Alternatively, addedvalue products can be made using sisal to produce alumina fibers (Al2O3) by biotemplating, which consists in the reproduction of the natural fiber-like structure of the starting material. The objective of this study was to evaluate the conditions necessary to convert sisal into alumina fibers by biotemplating. Alumina fibers were obtaining after pretreating sisal fibers and infiltrating them with a Al2Cl6 saturated solution, alumina sol from aluminum isopropoxide or aluminum gas. Heat-treating temperatures varied from 1200 ºC to 1650 °C. The resulting fibers were then characterized by X-ray diffraction and scanning electronic microscopy. Fibers obtained by liquid infiltration revealed conversion only of the surface of the fiber into α-Al2O3, which yielded limited resistance to handling. Gas infiltration resulted in stronger fibers with better reproduction of the inner structure of the original fiber. All converted fibers consisted of 100% α-Al2O3 suggesting a wide range of technological applications especially those that require thermal isolation

Avaliação da resistência mecânica de material leve utilizando misturas de pedaços de pneus com solo do Distrito Federal

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

Variabilidade espacial da resistência mecânica do solo à penetração sobre a produtividade do milho 2ª safra.

2016

Valores críticos de resistência à penetração em diferentes conteúdos de água do solo na sucessão soja/milho 2ª safra.

2016

Efeitos no solo do gesso produzido em diferentes reações químicas da solução de ácido sulfúrico reciclada com carbonato de cálcio residual e óxido de cálcio.

2011

Indicativo de resistência de plantas daninhas em sistemas de produção de grãos e fibras nos estados de Goiás e Minas Gerais.

2016

Características físicas e mecânicas de misturas de solo, cimento e cinzas de bagaço de cana-de-açúcar

This work was done with the objective of studying some physical and mechanical characteristics of the sugarcane bagasse ash added to a soil-cement mixture, in order to obtain an alternative construction material. The sugarcane bagasse ash pre-treatment included both sieving and grinding, before mixing with soil and cement. Different proportions of cement-ash were tested by determining its standard consistence and its compressive resistance at 7 and 28 days age. The various treatments were subsequently applied to the specimens molded with different soil-cement-ash mixtures which in turns were submitted to compaction, unconfined compression and water absorption laboratory tests. The results showed that it is possible to replace up to 20% of Portland cement by sugarcane bagasse ash without any damage to the mixture's compressive strength.