1,721,220 research outputs found
Basic principles, agents and feasibility of bioremediation of soil polluted by organic compounds
No full textBasic principles, agents and feasibility of bioremediation of soil polluted by organic compounds
No full text
Mineralizzazione della sostanza organica e assorbimento dei nutrienti da parte delle piante
No full textSono descritte le principali tappe della mineralizzazione della s.o. del suolo, i meccanismi che determinano il trasporto di nitrati, solfati e fosfati agli apparati radicali nonché i meccanismi propri del assorbimento nutrizionale presenti al plasmalemma delle cellule radicali
A representative SpaceFibre network evaluation: Features, performances and future trends
No full textSpaceFibre is a high-speed satellite on-board communication protocol. It allows high data rates (up to 6.25 Gbps per lane), advanced quality of service, fault detection isolation and recovery. Different SpaceFibre nodes can be combined, together with a SpaceFibre routing switch, to form a network. This work aims to describe the set-up of a SpaceFibre network, made of independently developed nodes. The performance of a simplified version of the network is then evaluated and measured, in terms of jitter and latency, for both data packets and broadcast messages, providing a first literature contribution about innovative SpaceFibre network timing performances. It will be a useful indication for future system adopters and could be the baseline for future in-depth measurement and investigation
Cadmium and zinc toxicity to soil microbial biomass and activity
No full textThe effects of sewage sludge selectively enriched with zinc at the maximum perrniued
level and cadmium at concentration four times the current EU limits on microbial biomass
and activity were tested using soils under different management in a laboratory incubation
experiment. The microbial biomass and activity and the heavy metal mobility were measured
over a period of six months. The resuits showed that neither zinc at the maximum permitted
level nor the cadmium at concentrations as high as four times the curent EU limits may have
major adverse effects on the microbial biomass and respiration of soils
VHDL design of a spacefibre routing switch
Full text linkThe technology advancement of satellite instruments requires increasingly fast interconnection technologies, for which no stan-dardised solution exists. SpaceFibre is the forthcoming protocol promising to overcome the limitation of its predecessor SpaceWire, offering data-rate higher than 1 Gbps. However, while several implementations of the SpaceFibre IP already exist, its Network Layer is still at experimental level. This article describes the architecture of an implemented SpaceFibre Routing Switch and provides synthesis results for common FPGAs
Hydrolase activities during and after the chloroform fumigation of soil as affected by protease activity
No full textCHCl3 fumigation was used to induce changes in hydrolase activities of a Vertisol under different management (woodland, grassland and arable soils). Measurements were made during the standard 24 h CHCl3 fumigation period used for biomass measurement and after incubation following fumigation. Fumigation of soil was very effective in killing microorganisms as shown by the marked decrease in the ATP content after 4 h of CHCl3 exposure. However, it did not change or slightly decreased β-glucosidase, acid phosphomonoesterase, alkaline phosphomonoesterase and protease as measured by hydrolysis of N-benzoylargininamide, markedly decreased urease activity and increased arylsulphatase activity. CHCl3 fumigation of soils for 24 h in the presence of several protease inhibitors decreased N-benzoylargininamide hydrolising activities by more than 50% and increased urease and phosphomonoesterase activities, demonstrating that enzymes released during cell lyses can undergo to proteolysis during the CHCl3 fumigation. During the incubation following fumigation, respiration increased following the typical trend. ATP content also increased in all soils because of the growth of the small microbial population surviving the fumigation. During the incubation following fumigation, β-glucosidase and phosphomonoesterase activities recovered to values not significantly different from those of unfumigated and incubated soil. Arylsulphatase activity decreased in all fumigated soils reaching values not significantly different from those of the unfumigated soils after 24 h. Benzoylargininamide hydrolyzing activities showed only minor changes during the incubation of unfumigated and fumigated soils. Urease activity decreased to low levels in the woodland soil and was not measurable in the grassland and arable soils. N metabolites, derived from the microbial NH4+ immobilization during the incubation following fumigation, may have inhibited the urease synthesis in microbial cells
Degradation of low molecular weight organic acids complexed with heavy metals in soil
No full textSoils contaminated with heavy metals also contain a number of organic ligands, particularly in the rhizosphere and thus, a fraction of the bioavailable metals in soils likely exists in a complexed form. The presence of soluble, metal-complexing organic ligands can influence the fate and transport of metals as well as mineralisation of organic compounds. Oxalate and citrate complexed with Cd, Cu, Mg, Pb and Zn were used as model metal-organic complexes possibly occurring in heavy metal contaminated soils. Soil respiration was used to determine the biodegradation of these compounds in a clay alkaline soil kept under different management regimes. Overall, the results indicated that metal complexes with citrate generally were more degradable than oxalate-metal complexes. For each organic acid, biodegradability of the metal-organic complexes varied for different metals, following the ranking order: Mg>Zn>Cu≅Pb>Cd. Addition of Cd complexes decreased the soil respiration. These results indicate that the formation of the complexes between heavy metals and low molecular weight organic ligands might affect the soil functionality, especially in the rhizosphere of contaminated soils, as determined by soil respiration
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