2 resultados para Natural products in agriculture

em Repositório Científico do Instituto Politécnico de Lisboa - Portugal


Relevância:

100.00% 100.00%

Publicador:

Resumo:

When timber elements in heritage buildings are moderately degraded by fungi and assuming underlying moisture problems have been solved, two actions can be taken: i) use a biocide to stop fungal activity; ii) consolidate the degraded elements so that the timber keeps on fulfilling its structural and decorative functions. The aim of this work is to investigate the mechanical performance of maritime pine wood degraded by fungi after being treated with a biocide followed by impregnation with a polymer product. Three commercially available products were used: a boron water-based biocide, an acrylic consolidant and an epoxy-based consolidant. Treated and consolidated specimens were subjected to mechanical tests: axial compression test (NP 618), static surface hardness (ISO 3350) and bending test (NP 619). Sets of replicates were subjected to an evaporation ageing test (EN 73) after application of the products and also tested for mechanical behaviour. An increase in mechanical strength was observed for both consolidants with no significant influence from the previous use of biocide product. The specimens subjected to ageing showed a slightly better general mechanical performance.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Composting is an important process of solid waste management and it can be used for treatment of a variety of different wastes (green waste, household waste, sewage sludge and more). This process aims to: 1. Reduce the volumes of waste and; 2. Create a valuable product which can be recycled as a soil amendment in agriculture and gardening. A natural self-heating process involving the biological degradation of organic matter under aerobic conditions. The handling of waste and compost is responsible for the release of airborne microorganisms and their compounds in the air. Possible contaminants: a) Dust; b) Mesophilic and thermophilic microorganisms; c) Volatile organic compounds; d) Endotoxins and mycotoxins…. Aim: assess exposure/contamination to: a) Volatile organic compounds (VOCs); b) Particulate matter (PM); c) Fungi. In a composting plant located in Lisbon. An additional goal was to identify the workplace with higher level of contamination. In a totally indoor composting plant. The composting operations consisted: 1º Waste already sorted is unloaded in a reception area; 2º Pretreatment - remove undesirable materials from the process (glass, rocks, plastics, metals…); 3º Anaerobic digestion; 4º Dehydration; 5º Open composting with forced aeration. All the process takes thirteen weeks.