Search results for "MELT"

Co-existing with the alien: evidence for environmental control on trophic interactions between a native (Atherina boyeri) and a non-indigenous fish s…

2022

Biological invasions are a widespread problem worldwide, as invasive non-indigenous species (NIS) may affect native populations through direct (e. g., predation) or indirect (e.g., competition) trophic interactions, leading to changes in the food web structure. The trophic relationships of the invasive eastern mosquitofish Gambusia holbrooki and the native big-scale sand smelt Atherina boyeri coexisting in three Mediterranean coastal ponds characterized by different trophic statuses (from oligotrophic to hypereutrophic) were assessed in spring through isotopic niche analysis and Bayesian mixing models. The two fish relied on the distinctive trophic pathways in the different ponds, with the …

Feeding ecology of the sand smelt, Atherina boyeri (Risso, 1810) (Osteichthyes, Atherinidae), in the western Mediterranean: evidence for spatial vari…

2005

The feeding ecology of the sand smelt Atherina boyeri Risso 1810 (Osteichthyes, Atherinidae) was investigated in a Mediterranean coastal basin (Stagnone di Marsala, Italy) by means of carbon and nitrogen stable isotope ratios. Sampling was carried out seasonally in 1999 in two locations characterised by different depth and vegetal coverage. Throughout the year the sand smelt showed enriched δ 13C and δ 15N values in both sampling locations (δ 13C about −12‰ and δ 15N about 12‰). This result suggests the overall importance of the benthic pathway in the food web leading to A. boyeri. Our isotopic picture is only in partial agreement with stomach content data from the literature. Stomach conte…

Melt inclusion study on the pantelleritic plinian eruption of the Green Tuff, Pantelleria Island.

2012

Pantelleria Island is the type locality for the peralkaline rhyolitic rocks called pantellerites. In the last 50 ka, after the Plinian, caldera-forming, Green Tuff eruption, volcanic activity at Pantelleria consisted of effusive and mildly explosive eruptions which mostly vented inside and along the rim of the caldera producing silicic lava flows, lava domes and poorly dispersed pantelleritic pumice fall deposits. During the last two decades, a wealth of studies focused on melt inclusions in pantellerite magmas, all converging in underlying the H2O-rich character of these melts together with high contents of halogens. Recent study on the volatile content of pantellerites from Pantelleria yi…

Polymer-based 'green' composites

2009

Aryldimethylsilyl Modified Hypersilanes

2008

Aryldimethylsilyl-substituted hypersilanes ArSiMe2Hyp [Hyp =Si(SiMe3)3; Ar = Mes (3a), Bph (3b), Mph (3c), Pph (3d), Tph (3e); Dpp (3f); with Mes = 2,4,6-Me3C6H2, Bph = 2-PhC6H4, Mph = 2-MesC6H4, Pph = 2′,3′,4′,5′,6′-pentamethylbiphenyl2-yl, Tph = 2′,4′,6′-triisopropylbiphenyl-2-yl and Dpp = 2,6-Ph2C6H3] have been synthesized by a multi-step reaction starting from the readily available starting materials ArI and (thf)xKHyp. For this purpose the aryl iodides were first converted into the lithium aryls by lithium-halogen exchange with n-butyl lithium. A salt-metathesis reaction with SiMe2Cl2 gave the corresponding arylchlorodimethylsilanes (2a–e) in excellent yields. Finally, reaction of 2a–e…

Physical modelling of the melt flow during large-diameter silicon single crystal growth

2003

Abstract The reported investigations concern physical modelling of Czochralski growth of silicon large-diameter single crystals. InGaSn eutectic was used as a modelling liquid, employing actual criteria of the real process (Prandtl, Reynolds, Grashof numbers, etc.) and geometric similarity. A multi-channel measuring system was used to collect and process the temperature and flow velocity data. The investigations were focused on the study of heat transfer, in particular, the instability of the “cold zone” of the melt at the crystallization front.

Modelling of electromagnetic heating and mixing conditions in glass melt output equipment

2011

PurposeThe purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.Design/methodology/approachNumerical calculations in ANSYS and ANSYS CFX were used to study electromagnetic, thermal, hydrodynamic and chemical mixing processes, results are validated by comparison with experimental data.FindingsObtained results show that investigated approach can improve glass melt chemical homogeneity significantly – Lorentz force driven melt movement in conjunction with diffusion process ensures good mixing quality.Research limitations/implicationsThe mixing in glass melt is present only in azimuthal direction (in cyl…

1985

From the break-down in the viscosity and from the increase of the intensity of the scattered light, associated with the entrance into the two-phase region, the pressure dependence of the demixing temperature of solutions of PVC 37 000, PVC 75 000 and PVC 100 000 in phenetole and PVC 75 000 in o-xylene was measured up to 1 000 bar. (The numbers in the codes of the PVC specimens are their approximate molecular weights.) The application of pressure increases the demixing temperatures of PVC in both solvents by about 1 K/100 bar. For a qualitative forecast of the pressure effects, the solubility parameter theory in combination with the corresponding states principle, and an empirical correlatio…

Bioclimatic atlas of the terrestrial Arctic

2023

AbstractThe Arctic is the region on Earth that is warming at the fastest rate. In addition to rising means of temperature-related variables, Arctic ecosystems are affected by increasingly frequent extreme weather events causing disturbance to Arctic ecosystems. Here, we introduce a new dataset of bioclimatic indices relevant for investigating the changes of Arctic terrestrial ecosystems. The dataset, called ARCLIM, consists of several climate and event-type indices for the northern high-latitude land areas > 45°N. The indices are calculated from the hourly ERA5-Land reanalysis data for 1950–2021 in a spatial grid of 0.1 degree (~9 km) resolution. The indices are provided in three subsets…

Synthesis of new melatoninergic hexahydroindenopyridines

2014

Hexahydroindenopyridine (HHIP) is an interesting heterocyclic framework that contains an indene core similar to ramelteon. This type of tricyclic piperidines aroused our interest as potential melatoninergic ligands. Melatonin receptor ligands have applications in insomnia and depression. We report herein an efficient two-step method to prepare new HHIP by the reaction of an enamine with 3-bromopropylamine hydrobromide. Some synthesized compounds showed moderate affinity for melatonin receptors in the nanomolar or low micromolar range. Furthermore, the methylenedioxy HHIPs 2d (N-phenylacetamide) and 2f (N,N-diethylacetamide), exhibited high selectivity at MT1 or MT2 receptors, respectively, …