Search results for "perch"
showing 10 items of 1084 documents
Modeling of perched leachate zone formation in municipal solid waste landfills.
2010
The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model was based on mass balance equations, that enable simulation of the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the inflow to and outflow from each layer as well as the continuous moisture distribution. The infiltration flow was evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solu…
Ecological divergence of closely related Diplostomum (Trematoda) parasites.
2006
Parasite life-cycles present intriguing model systems to study divergence in resource use and ecology between parasite taxa. In ecologically similar taxa, consistent selective forces may lead to convergence of life-history traits, but resource overlap and similarity of life-cycles may also promote divergence between the taxa in (1) use of host species or (2) specific niche within a host. We studied the life-history characteristics of 2 sympatric species of Diplostomum parasites, D. spathaceum and D. gasterostei, concentrating particularly on differences in intermediate host use and characteristics of the infective stages between the species. This group of trematodes is a notoriously difficu…
Mössbauer effect study of the electronic ground state of iron(II)in tris(2-chlorophenanthroline)iron(II) perchlorate
1976
Abstract Mossbauer spectra of [Fe(2-Cl-phen) 3 ](ClO 4 ) 2 ·H 2 O have been measured in the temperature range 293 − 5 K. The spectra indicate that the iron atom in this compound possesses a spin quintet ground state throughout the temperature range under study, in contradiction to the suggested high spin-low spin transition, which has been concluded from a magnetic susceptibility study by other authors. From a theoretical analysis of the temperature dependence of the quadrupole splitting, with trigonal distortion, spin-orbit coupling, and effects of covalency taken into account, the ground term of iron(II) in this compound has been elucidated as being 5 A 1 ( 5 T 2g ), separated from the 5 …
La dote, il ius singulare e il ‘sistema didattico’ di Gaio
2016
This paper discusses the idea that the gap regarding the dowry in Gaius’ Institutes is due to the fact that Gaius intentionally did not deal with this subject because he considered it as 'ius singulare' and that this omission was filled in by a 'liber singularis' outside the Institutes. The existence of a "didactic system" made up of the Gaius’ Institutes and four 'libri singulares' for the classical age of Roman Law is also disputed.
Short-term atorvastatin treatment does not modify neointimal morphology but reduces MMP-2 expression in normocholesterolemic rabbit stented arteries.
2006
The aim of our study was to explore some potential pleiotropic effects of atorvastatin, after stenting in the iliac arteries of normocholesterolemic rabbits. On day 0, 27 rabbits underwent stent implantation and were randomized into either the control group (standard chow, CTRL, n = 15) or the atorvastatin group (10 mg/kg/d per os, Ator, n = 12). On day 30, the stented arteries were harvested for histomorphometry and neointimal analysis [macrophages, matrix metalloproteinases (MMP-2), tissue inhibitor of metalloproteinase-2, vascular smooth muscle cells, and collagen]. Atorvastatin did not induce significant histomorphometric and inflammatory modifications but reduced neointimal expression …
Nucleophilic attack by 2-pyridylpalladium(II) and platinum(II) complexes on the organic chlorides ClCH2R (R COMe, CN, Ph, Cl)
1992
Abstract The 2-pyridyl complexes trans-[MCl(C5H4NC2)(PPh3)2] (M = Pd, 1a; M = Pt, 1b), [MCl(C5H4NC2)(dppe)] (M = Pd, 2a; M = Pt, 2b) and [M(dmtc)(C5H4NC2) (PPh3)] (M = Pd, 3a; M = Pt,3b) react with the chlorides ClCH2R(R COMe, CN, Ph) to give cationic products containing the 2-pyridylium ligands (1-CH2R)C5H4NC2. The rate of nucleophilic displacement of the chloride ion from ClCH2R depends on the central metal (Pt > Pd), on the coordination geometry (1 ~ 3) and on the substituent R (COMe > CN > Ph for the reactions with 3b). Like 1b and 2b, complex 3b also reacts with dichloromethane to give [Pt(dmtc){(1-CH2Cl)C5H4NC2}(PPh3)]+. The reaction of the binuclear compound [{PdCl(μ-C5H4NC2,…
Light Composite Higgs from Higher Representations versus Electroweak Precision Measurements -- Predictions for LHC
2005
We investigate theories in which the technifermions in higher dimensional representations of the technicolor gauge group dynamically break the electroweak symmetry of the standard model. For the two-index symmetric representation of the gauge group the lowest number of techniflavors needed to render the underlying gauge theory quasi conformal is two. We confront the models with the recent electroweak precision measurements and demonstrate that the two technicolor theory is a valid candidate for a dynamical breaking of the electroweak symmetry. The electroweak precision measurements provide useful constraints on the relative mass splitting of the new leptons needed to cure the Witten anomaly…
Le site néolithique final de la Bastide Blanche (Peyrolles-en-Provence, Bouches-du-Rhône) : Premiers résultats 2003-2004
2006
The Bastide Blanche (Peyrolles-en-Provence, Bouches-du-Rhône) is a small settlement perched in edge of the Durance where the principal occupation is ascribable to the extreme end of the Neolithic era. Recognized in the past, it was the subject of multiple excavations but of any study nor of any specific publication. A survey campaign and a first excavation campaign programmed in 2003 and 2004 make it possible today to specify the homogeneity of the assemblies often mentioned in the scientific literature. Beyond the first description of the structures and archaeological furniture put at the day, this short note makes it possible to announce the existence of a sequence for the Rhone-Ouvèze gr…
Effect of Lithium Perchlorate on the Kinetics of the Anionic Polymerization of Methyl Methacrylate in Tetrahydrofuran
1999
The kinetics of the anionic polymerization of methyl methacrylate in the presence of lithium perchlorate (LiClO 4 ) are investigated in THF using 1,1-diphenylhexyllithium as initiator in a flow-tube reactor between -30 and 0 °C. The rate constants of propagation determined in the presence of LiClO 4 are lower than those obtained in the absence of the salt, similar to the effect observed for LiCl. For propagation, the reaction order with respect to active center concentration is found to be 0.5 in both cases, which indicates that LiClO 4 does not effectively perturb the aggregation of the enolate ion pair. The formation of various mixed aggregates is proposed. The polydispersity index of the…
Dimensional variability of nonstandardized greater taper finger spreaders with matching gutta-percha points
2001
Aim The purpose of this research was to determine the compatibility and dimensional variability between nonstandardized gutta-percha points and matching finger spreaders. Methodology The diameters of nonstandardized gutta-percha points (n = 15) and matching finger spreaders (n = 15) from different manufacturers (Kerr, Dentsply Maillefer, Vereignigte Dentalwerke and Roeko) were determined and statistically analysed using a profile projector under a magnification of 50 × (±0.002 mm). Results The dimensions of the finger spreaders and gutta-percha cones were inconsistent. Of the 29 groups of nonstandardized gutta-percha cones evaluated, 22 had standard deviations larger than 0.020 at D1. The s…