Field trial of a new aeration system for enhancing biodegradation in a biopile

The influence of a new aeration system on the biopile performance was investigated. The purpose was to increase biodegradation efficiency by optimising airflow through the pile. During a 1-month field trial, the performance of a new system using two perforated vertical pipes with wind-driven turbines was compared with that of a standard pile configuration with two horizontal perforated pipes. Both piles were composed of a similar mix of diesel-contaminated soils, woodchips, compost and NPK fertiliser. Hydrocarbons were recovered using solvent extraction, and determined both gravimetrically and by gas chromatography. Total heterotrophs, pH and moisture content were also assessed. Air pressure measurements were made to compare the efficiency of suction in the pipes. Results at the end of the experiment showed that there was no significant difference between the two piles in the total amount of hydrocarbon biodegradation. The normalised degradation rate was, however, considerably higher in the new system than in the standard one, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile. The pressure measurements showed a significant improvement in the suction produced by the new aeration system. However, many factors other than the airflow (oxygen supply) may influence and limit the biodegradation rates, including moisture content, age of contaminants and the climatic conditions. Additional experiments and modelling need to be carried out to explore further the new aeration method and to develop criteria and guidelines for engineering design of optimal aeration schemes in order to achieve maximum biodegradation in biopiles. (C) 2003 Elsevier Ltd. All rights reserved.

Revision of Affecauda Hall & Chambers, 1999 (Digenea: Gyliauchenidae Fukui, 1929), including the description of two new species from fishes of the Indo-West Pacific

We describe 2 new species of Affecauda from the intestine of acanthuroid fishes of the Indo-West Pacific. Affecauda rugosa n. sp. is described from 1 mature specimen in excellent condition and 1 immature fractured specimen from the intestine of the sailfin tang, Zebrasoma veliferum (Acanthuridae), from Noumea, New Caledonia. Affecauda salacia n. sp. is described from the intestine of the ocellated spinefoot, Siganus corallinus (Siganidae), from Lizard Island, Great Barrier Reef, Queensland, Australia. Each of these species is made distinct from the type-species, Affecauda annulata Hall & Chambers, 1999, by combinations of the extent of tegumental annulations, conformation of the oesophagus and position of the ovary. The description of 2 new species of Affecauda necessitates a revision of the generic diagnosis, which is here amended to incorporate the additional species. A key to species is provided. The description of further species of Affecauda from waters external to the Great Barrier Reef and from siganid fishes expands the biogeographical range for species of Affecauda, from species of Naso on the Great Barrier Reef, to acanthuroid fishes of the western Pacific.

Solid phase microextraction of stale flavour volatiles from the headspace of UHT milk

Solid phase microextraction (SPME) offers a solvent-free and less labour-intensive alternative to traditional flavour isolation techniques. In this instance, SPME was optimised for the extraction of 17 stale flavour volatiles (C3-11,13 methyl ketones and C4-10 saturated aldehydes) from the headspace of full-cream ultrahigh-temperature (UHT)-processed milk. A comparison of relative extraction efficiencies was made using three fibre coatings, three extraction times and three extraction temperatures. Linearity of calibration curves, limits of detection and repeatability (coefficients of variation) were also used in determining the optimum extraction conditions. A 2 cm fibre coating of 50130 gm divinylbenzene/Carboxen/polydimethylsiloxane in conjunction with a 15 min extraction at 40 degrees C were chosen as the final optimum conditions. This method can be used as an objective tool for monitoring the flavour quality of UHT milk during storage. (c) 2005 Society of Chemical Industry.

Cone topography and spectral sensitivity in two potentially trichromatic marsupials, the quokka (Setonix brachyurus) and quenda (Isoodon obesulus)

The potential for trichromacy in mammals, thought to be unique to primates, was recently discovered in two Australian marsupials. Whether the presence of three cone types, sensitive to short- (SWS), medium-(MWS) and long-(LWS) wavelengths, occurs across all marsupials remains unknown. Here, we have investigated the presence, distribution and spectral sensitivity of cone types in two further species, the quokka (Setonix brachyurus) and quenda (Isoodon obesulus). Immunohistochemistry revealed that SWS cones in the quokka are concentrated in dorso-temporal retina, while in the quenda, two peaks were identified in naso-ventral and dorso-temporal retina. In both species, MWS/LWS cone spatial distributions matched those of retinal ganglion cells. Microspectrophotometry (MSP) confirmed that MWS and LWS cones are spectrally distinct, with mean wavelengths of maximum absorbance at 502 and 538 nm in the quokka, and at 509 and 551 nm, in the quenda. Although small SWS cone outer segments precluded MSP measurements, molecular analysis identified substitutions at key sites, accounting for a spectral shift from ultraviolet in the quenda to violet in the quokka. The presence of three cone types, along with previous findings in the fat-tailed dunnart and honey possum, suggests that three spectrally distinct cone types are a feature spanning the marsupials.

Thermal stability analysis of organo-silicates, using solid phase microextraction techniques

An analysis of thermal degradation products evolved during the melt processing of organo-layered silicates (OLS) was carried out via the use of a solid phase microextraction (SPME) technique. Two commerical OLSs and one produced in-house were prepared for comparision. The solid phase microextraction technique proved to be a very effective technique for investigating the degradation of the OLS at a specific processing temperature. The results showed that most available OLSs will degrade under typical conditions required for the melt processing of many polymers, including thermoplastic polyurethanes. It is suggested that these degradation products may lead to changes in the structure and properties of the final polymer, particularly in thermoplastic polyurethanes, which seem significantly succeptable to the presence of these products. It is also suggested that many commercially available OLSs are produced in such a way that results in an excess of unbound organic modifier, giving rise to a greater quantity of degradation products. All OLSs where compared and characterised by TGA and GC-MS. (c) 2004 Elsevier B.V. All rights reserved.

Phylogeny, evolution and biogeography of the Quadrifoliovariinae Yamaguti, 1965 (Digenea : Lecithasteridae)

The Quadrifoliovariinae is revised and three new species of Quadrifoliovarium Yamaguit, 1965 from acanthurid fishes of the genus Naso from waters of the Indo-Pacific are described: Q, maceria n. sp. from N. tonganus, N. annulatus, N. fageni and N. brevirostris; Q. simplex n. sp. from N. tonganus and N. quannulatus; and Q. quattuordecim n. sp. from N. tonganus. Amendments are made to the characterisation of the Quadrifoliovariinae, Quadrifoliovarium, Bilacinia Manter, 1969 and Unilacinia Manter, 1969 in light of observations on type and new material. A molecular phylogeny based on ITS2 and 28S regions of the ribosomal DNA is proposed. The phylogeny suggests that U. asymmetrica is the most basal taxon and Q. simplex n. sp. and Q. quattuordecim n. sp. the most derived. Evolution of morphological traits within the Quadrifoliovariinae are discussed in light of the molecular phylogeny. Molecular sequences of the ITS2 rDNA were identical between specimens of Q. pritchardae collected off Exmouth (Indian Ocean), Heron Island and Lizard Island (Western Pacific) and Moorea (far Eastern Indo-Pacific), indicating a broad Indo-Pacific distribution. All members of the subfamily are recorded only from the acanthurid genus Naso, with the exception of B. lobatum (Yamaguti, 1970), which has been recorded from a pomacanthid. The restricted host range of the group is discussed in the light of the phylogeny of the host genus Naso.