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The recovery of chlorobenzenes (di- to hexachloro) and hexachlorocyclohexane (HCH) isomers from supercritical carbon dioxide by trapping in cold solvent was studied. By changes in supercritical pressure, flow rate, nature and temperature of the solvent, and trap geometry, recoveries of chlorobenzenes varied in the range 80-100%, and those of HCH in the range 50-94%. For the optimum set of variables, the average recovery of all compounds was 95%. With these trapping conditions, an environmental soil sample gave average supercritical fluid extraction (SFE) recoveries (compared to Soxhlet extraction) of 60-85%, depending on the SFE conditions.

The Longola protohistoric village (spanning from the late Middle Bronze Age to the sixth century bc) is a perifluvial settlement located in the Sarno River floodplain to the north-east of Pompeii (southern Italy) and east of the Somma-Vesuvius volcano. A great abundance of artefacts have been found at Longola and in the neighbouring areas, including a variety of volcanic stone objects, mainly related to building and to the manufacture of ordinary tools and instruments. The aim of our work is to characterize lithic objects (lava pebbles and millstones) and to understand their geological provenance by petrographic and geochemical studies. Compositions of millstone samples (porphyritic phonolitic tephrites) and of a set of pebbles (mainly phonolitic tephrites, leucite-shoshonites and trachytes) are compatible with the Somma-Vesuvius magmas erupted before 8 ka bp. For the trachyte lithics, an additional source from the Accademia lava dome (Phlegrean Fields) cannot be ruled out. Among the pebble samples, a rhyolite and a poorly evolved trachyte clearly lie outside the compositional variation of the Somma-Vesuvius and other volcanoes of the Naples area (e.g., Ischia and the Phlegrean Fields) and emphasize an extra-regional provenance. Ponza Island is the best candidate for the provenance of the above two outlier samples. [ABSTRACT FROM AUTHOR]

A Large-Eddy Simulation (LES) modeling framework, dedicated to ultra-lean spark-ignition engines, is proposed and validated in the present work. A direct injection research engine is retained as benchmark configuration. The LES model is initially validated using the cold gas-exchange conditions by comparing numerical results with PIV (Particle Imaging Velocimetry) experimental data. Then, the fired configuration is investigated, combining ECFM (Extended Coherent Flame Model) turbulent combustion model with Adaptive Mesh Refinement (AMR). The capability of the model to reproduce experimental pressure envelope and cycle-to-cycle variability is assessed. Within the major scope of the work, a particular focus on the Combustion Cyclic Variability (CCV) is made correlating them with the variability encountered in the in-cylinder aerodynamic variations. R3P4. Finally two post-processing tools, Empirical Mode Decomposition (EMD) and Γ3p function, are proposed and combined to analyse for the first time the aerodynamic tumble-based in-cylinder velocity field. Both tools make it possible to get deeply into the insight and visualization of the flow field and to understand the links between its cyclic variability and the combustion cyclic variability.

Total length ( LT) (range 24-1000 mm; mean ± s.e. = 170·21 ± 0·36 mm) and mass ( W) (range 0·10-9590 g; mean ± s.e. = 76·03 ± 0·87 g) of 36 460 specimens of marble trout Salmo marmoratus were used to compute a standard mass ( Ws) equation for this species by means of the empirical percentile (EmP) method. The EmP Ws equation calculated was: log10 Ws = −5·208 + 3·202 log10 LT− 0·046 (log10 LT)2 ( LT range 90-570 mm) and it is valid throughout the species' area of distribution across Europe. [ABSTRACT FROM AUTHOR]

Total length ( L) and mass measurements of 28 596 specimens of European chub Leuciscus cephalus, collected from a variety of waterways across Italy, were used to compute standard mass ( W) equations by both empirical percentile (EmP) and regression line percentile (RLP) methods. The use of the EmP W equation [log W = −4·79 + 2·68log L + 0·10(log L)] to compute relative mass ( W) of L. cephalus in Italy is suggested, as it was not influenced by length-related bias ( L range of application = 70-470 mm). [ABSTRACT FROM AUTHOR]

The use of corrosion-resistant alloys (CPA) has allowed oil and gas operations in environments where carbon and low-alloy steels would have otherwise corroded too quickly, increasing downtime and maintenance costs. However, CPA may suffer from localized corrosion in the form of pitting, crevice, and! or stress corrosion cracking (SCC). Therefore, it is important to determine the susceptibility to localized corrosion in service conditions with minimal or no external perturbation. In this work, electrochemical noise (ECN) analysis was used to determine the pitting corrosion susceptibility of 13Cr and super 13Cr martens itic stainless steels in simulated production environments in equilibrium with up to 850 ppm hydrogen sulfide (H2S)(g) and 1.7% carbon dioxide (CO2)(g), bal. N2(g), at elevated pressures. In contrast to similar experimental arrays, coupons remained disconnected (i.e., exposed individually at their free corrosion potential) for most of the test duration except for intervals of 1,024 s in which ECN measurements were conducted. Temperature was increased stepwise from 25°C to 200°C after each ECN block. During ECN measurements, current fluctuations were recorded using a zero-resistance ammeter (ZRA) and the potential of the pair was recorded simultaneously under steady-state conditions. This procedure was fully automated and required minimal user intervention. [ABSTRACT FROM AUTHOR]