37 research outputs found
Creative Thinking and Modelling for the Decision Support in Water Management
This paper reviews the state of art in knowledge and preferences elicitation techniques. The purpose of the study was to evaluate various cognitive mapping techniques in order to conclude with the identification of the optimal technique for the NetSyMod methodology. Network Analysis Creative System Modelling (NetSyMod) methodology has been designed for the improvement of decision support systems (DSS) with respect to the environmental problems. In the paper the difference is made between experts and stakeholders knowledge and preference elicitation methods. The suggested technique is very similar to the Nominal Group Techniques (NGT) with the external representation of the analysed problem by means of the Hodgson Hexagons. The evolving methodology is undergoing tests within several EU-funded projects such as: ITAES, IISIM, NostrumDSS
Aproveitamento de escória de siderurgia em substratos alternativos para produção de mudas de pimenteira Dedo-de-moça
"Estudos relacionados com o aproveitamento de escória de siderurgia tornaram-se imprescindíveis, pela possibilidade de seu uso como componente de substratos na produção de mudas e por esse uso minimizar o risco de contaminação ambiental, decorrente do descarte inadequado. Assim, objetivou-se, com este trabalho, avaliar o efeito de níveis crescentes de escória de siderurgia em substratos, compostos por solo com esterco bovino curtido e areia, nas variáveis de crescimento e na qualidade de mudas de pimenteira dedo-de-moça (Capsicum baccatum L.). Utilizou-se o delineamento em blocos casualizados, tendo como tratamentos cinco concentrações de escória (0%; 2,5%; 5%; 10% e; 20%) e quatro repetições. As avaliações ocorreram aos 55 dias após semeadura, consistindo na contagem do número de folhas, na medição da altura de planta e do diâmetro do coleto, na quantificação das massas secas de folhas e raízes da planta e na determinação do Índice de Qualidade de Dickson. Modelos de regressão foram ajustados (P < 0,05) aos tratamentos com níveis crescentes de escória de siderurgia. A adição em torno de 10% de escória ao substrato proporcionou os maiores valores das variáveis de crescimento, em mudas de pimenteira Dedo-de-moça.
Partially acidulated phosphate rocks: Controlled release phosphorus fertilizers for more sustainable agriculture
An assessment of the agronomic efficiency of partially acidulated phosphate rock fertilisers
The effect of the level of phosphate rock application on its dissolution in soil and on bicarbonate-soluble phosphorus
Use of inorganic wastes as immobilizing agents for soluble P in green waste-based composts
The study examines the effectiveness of red mud, blast furnace (BF) slag, and alum-derived water treatment sludge as immobilizing agents for excessive soluble P that had accumulated in three green waste-based composts.The three wastes were applied at 0%, 5%, 10%, and 20% w/w to three different composts, all containing extremely high concentrations of extractable P, and were incubated for 60 days. Water-soluble P was measured regularly throughout the incubation period, and at the end, P extractable with resin, 0.05 M NaHCO(3), and 0.005 M H(2)SO(4) were also measured.In the water extracts, inorganic P made up more than 85% of the total P present. All three materials had the ability to adsorb P and thus lowered water-soluble P concentrations. Water treatment sludge was clearly the most effective material, and this was attributed to its amorphous nature (thus, large Brunauer-Emmett-Teller surface area) and its acid pH (6.8) compared with the alkaline pH (10-11) of the other two materials. Water treatment sludge was also the most effective at lowering resin- and NaHCO(3)-extractable P. When H(2)SO(4) was used as the extractant, BF slag tended to be the most effective material at lowering extractable P, followed by water treatment sludge, and red mud. That is, the P immobilized by water treatment sludge was extractable with acid but not with water, resin, or NaHCO(3).Water treatment sludge has the potential to be used as an effective immobilizing agent for soluble P in composts, and it should be trialed under field conditions
