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EXPANDING THE KNOWN DISTRIBUTION OF CHIROCEPHALUS KERKYRENSIS PESTA, 1936 (BRANCHIOPODA, ANOSTRACA) IN ITALY
No full textA recent Italian record of Chirocephalus kerkyrensis Pesta, 1936 expands the known distribution of the species in Italy and provides new information about its supposed home range. The discovery of the species at 508 m above the sea level raises questions about our previous knowledge of the species and illustrates the problem of inadequate information about Anostraca in Italy
On the rediscovery of Chirocephalus ruffoi Cottarelli & Mura, 1984 from temporary pools of the Secchia and Panaro Valleys (Tuscan-Emilian Apennines, Northern Italy
No full textThe data presented in this note extend the known distribution of the anostracan Chirocephalus ruffoi Cottarelli & Mura, 1984, an endemic Italian species. The additional localities reported here had been sampled occasionally from the late 1940s to the early 1960s, but at that time the species was misidentified as C. diaphanus Prévost, 1803. Re-examination of the sampled material, including resting-egg morphology, during this study has demonstrated that in fact the misidentified specimens belong to C. ruffoi, a species known to occur at other sites in the Tuscan-Emilian Apennines. The usefulness of scanning electron microscopy for examining egg-shell morphology in order to aid, at least in certain cases, in a correct identification of species of Anostraca, is stressed
Biodegradation of 2-chlorophenol in forest soil: effect of inoculation with aerobic sewage sludge
No full textDecontamination of 2-monochlorophenol–containing forest soil was studied in laboratory experiments. We found that
in sterile soil, sorption of chlorophenol can occur. Chlorophenol disappearance of approximately 55% was observed in native soil;
both soil sorption and degradation by indigenous soil populations caused this disappearance. In native soil, however, the rate of
chlorophenol disappearance was enhanced up to slightly more than 90% by inoculation with a sludge taken from the aeration tank
of a municipal wastewater treatment plant. In this sludge, the presence of Alcaligenes and Pseudomonas spp. was observed. In
other experiments, addition to the soil of a laboratory culture preacclimated to 2-monochlorophenol did not lead to a greater increase
in chlorophenol disappearance. In contrast to native soil, inoculation of sterile soil had no effect on disappearance of the chlorophenol.
A possible explanation for the lack of cometabolic degradation is that autoclaving of the soil destroys the organic substances
within it
Peculiar failure mechanisms in GaN power transistors
Full text linkCommercial GaN power amplifiers for RF applications, made of a pair of discrete transistors for operation in Doherty configuration, failed during the HAST tests. Failure Analysis pointed out a layout-specific issue related to thermal expansion at the level of the field plates. Anyway, the search for initial degradation stages using Optical Beam Induced Resistance Change and Photon Emission Microscopy revealed a subtle second mechanism, involving Ga interdiffusion into the gate metal lines, coming from hollow pipes in GaN. Both mechanisms are discussed
Filtri anaerobici a basso carico per il trattamento dei reflui acquosi dei frantoi oleari
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