Fish, Marmelos Conservation Area (BX044), Madeira River basin, states of Amazonas and Rondônia, Brazil.

The present study provides a species list of fish from the Marmelos River Area – BX044 in the states ofAmazonas and Rondônia in northern Brazil. During a Rapid Ecological Assessment (REA) performed in October andNovember of 2003, 133 fish species from six orders and 24 families were recorded. The most diverse families wereCharacidae (47 species), Cichlidae (15 species), Loricariidae (12 species) and Pimelodidae (7 species). 23 fish specieswere common to the entire river basin and 4 were endemic to the aquatic system studied

Nitrification-denitrification in WSP: a mechanism for permanent nitrogen removal in maturation ponds

A pilot-scale primary maturation pond was spiked with 15N-labelled ammonia (15NH4Cl) and 15N labelled nitrite (Na15NO2), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of δ15N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity

A 43-Gbps Lithium Niobate Modulator Driver Module

This paper describes the realization of a 43-Gbps Lithium Niobate modulator driver module. The NRZ driver module utilizes four stages of GaAs p-HEMT MMIC amplifiers integrated with an output level detector and feedback loop to provide thermal stability and external control of the output swing. The bias and loop control circuitry are contained in the housing on a PC board external to the sealed MIC section. The integrated module (50.8 x 73.4 x 9.5 mm 3) provides 6.0 Vp-p controllable single-ended output voltage while dissipating only 4 watt

Stability of glassy hierarchical networks

The structure of interactions in most animal and human societies can be best represented by complex hierarchical networks. In order to maintain close-to-optimal function both stability and adaptability are necessary. Here we investigate the stability of hierarchical networks that emerge from the simulations of an organization type with an efficiency function reminiscent of the Hamiltonian of spin glasses. Using this quantitative approach we find a number of expected (from everyday observations) and highly non-trivial results for the obtained locally optimal networks, including, for example: (i) stability increases with growing efficiency and level of hierarchy; (ii) the same perturbation results in a larger change for more efficient states; (iii) networks with a lower level of hierarchy become more efficient after perturbation; (iv) due to the huge number of possible optimal states only a small fraction of them exhibit resilience and, finally, (v) 'attacks' targeting the nodes selectively (regarding their position in the hierarchy) can result in paradoxical outcomes

Hydrogen via reforming aqueous ammonia and biomethane co-products of wastewater treatment: environmental and economic sustainability

Green H2 is increasingly viewed as a key energy carrier for the fight against climate change. Wastewater treatment plants (WWTPs) have the unique potential to be centres of renewable H2 generation with the growing availability of two attractive feedstocks: biomethane and ammonia. An innovative and novel method of ammonia recovery from digestate liquor followed by a state-of-the-art H2 production process named NWaste2H2 is demonstrated for a case-study WWTP. The recovered ammonia is used alongside biomethane for H2 production and its diversion from conventional biological treatment has two other crucial benefits, with reductions in both associated electricity demand and emissions of nitrous oxide, an extremely potent greenhouse gas. Process modelling, supported by extensive experiments in a packed-bed reactor at bench-scale, demonstrate the prized capability of simultaneously performing steam methane reforming and ammonia decomposition to generate a H2-rich syngas with yields close to equilibrium values. Greenhouse gas emission abatement from the replacement of diesel buses and reduced N2O emissions from biological treatment could save up to 17.2 kg CO2 equivalent (CO2e) per year for each person served by the WWTP. An in-depth economic study illustrates the ability to achieve a positive net present value with a 10% discount factor as early as 5.8 years when the H2 is prepared and sold to power fuel cell electric buses

Núcleo temático de apicultura e meliponicultura: plano de gestão.

Introdução; Tema; Focos de ação; Objetivo geral; Objetivos específicos; Portfólio de projetos de P&D; Metas técnicas referentes ao III PDU (2004-2007); Equipe de pesquisadores; Equipe de apoio; Laboratórios vinculados ao núcleo; Infra-estrutura; Referência bibliográfica.bitstream/item/37202/1/Doc115.pd

Nitrogen in the Tapajos National forest: What's happening?

Nitrogen (N) is of fundamental importance to forest nutrient cycling. In many places its excess brings serious consequences to the environment, especially to the vegetation and water. At Tapajos National Forest ? (TNF), located along the northern end of the Tapajos River, we have been measuring nutrient deposition since 2003, when rice and soybean were being cultivated using intensive, fertilizer-based methods. Recently, corn has begun to be planted in place of rice and soy due to more favorable market conditions. Weekly collections of rainfall (4) and throughfall (25) samples inside the forest have shown that high inputs of N are entering the forest through wet-deposition, and that N input amount is correlated with site preparation and crop planting, and also with the size of the area planted. We speculate that the application of fertilizers to the agricultural areas to the East of the TNF is responsible for the high values of N entering the forest, principally through the mechanism of hydrolysis of urea. Sampling work has recently been expanded to forest areas situated far from intensive agriculture, and it is expected that forthcoming results will show reduced rates of N deposition in comparison to that measured in the TNF.Poster 23. Disponível também on-line