Search results for "positio"
showing 10 items of 6813 documents
De la performance musicale dans la Guyane traditionnelle : expression cognitive singulière d?une musique-verbe
2021
Guianese culture and traditional music, here evoked, are various. It is more a transcultural process that, along centuries, gave an original result born in the Americas, in Guiana in this case. It is a form of refoundation, of recreation of cultures and new human beings generally called Creoles. The musical performance, that I study here, is the echo of social and cultural space of this reformulation of thought, life, and conception of the world. It is, as well, a mean of transposition and transformation of the values issued of diverse sources and categories. It is in no way a second-rate cultural practice, as it is the place where were born philosophies and actions for common life as well …
Characterization of Chlorolignins in Bleached Kraft Pulp Mill Effluents Using Elemental Analysis and Fingerprinting by CuO Oxidation And Hplc
1994
Abstract Elemental analyses and chemical degradation techniques were applied to characterize lignin compounds in different stages of the chlorine bleaching process and in total mill effluent. Ultrafiltration was used for separation of chlorolignins into three nominal molecular weight fractions. Alkaline CuO oxidation products were analyzed by HPLC with diode array detection. Major compounds were identified by reference to authentic compounds. For comparison, native lignins (MWL), kraft lignins, and humic substances were studied as well. The oxygen, carbon and organic chlorine contents were closely similar in the various mill samples and their fractions. In all mill samples, vanillin and 6-c…
In Situ Heating TEM Study of Onion-like WS2 and MoS2 Nanostructures Obtained via MOCVD
2007
We report on the in situ heating transmission electron microscopy (TEM) study of WS2 and MoS2 nanoparticles obtained from metal–organic chemical vapor deposition (MOCVD). The general behavior of MoS2 and WS2 is similar: Round, amorphous particles in the pristine sample transform to hollow, onion-like particles upon annealing. A second type of particle with straight layers exhibits only minor changes. A significant difference between both compounds could be demonstrated in their crystallization behavior. The results of the in situ heating experiments are compared to those obtained from an ex situ annealing process under Ar.
Creating Individual Journal Rankings Based on a Community Approach
2010
Selecting appropriate publication outlets is crucial to any researcher. Journal rankings can be used to guide the selection, but their usefulness may be limited for particular audiences. In this paper, it is argued that especially young researchers and researchers in interdisciplinary fields can benefit from targeting research efforts to a specific community. This can be facilitated by an individually built journal ranking that exploits a community building perspective and by a more transparent process of use. The approach introduced here is based on an analysis of both traditional journal rankings and behavior of academic communities. As a result, we present a procedure for building and us…
Integrated analytical methodologies for the study of corrosion processes in archaeological bronzes
2011
Abstract The investigations on structure and micro-chemical composition of archaeological metal alloys are needed in archaeometry. The aim of this study is devoted both to acquire information about their provenance and production technology, and to improve our understanding about the corrosion processes. In this paper we present the study of the corrosion phenomena of bronze samples, laboratory-made according to binary, ternary and quaternary alloys typical of Roman archaeometallurgical production through an integrated methodology based on the use of non or micro invasive physical techniques. Among the analysed samples, two were artificially aged through burial in the archaeological site of…
σ-Hammett parameter: a strategy to enhance both photo- and electro-luminescence features of heteroleptic copper(i) complexes
2017
This work studies the effect of the σ-Hammett parameter (σp) – i.e., the σ-donation effect caused by substitution at the para position of a bipyridine ligand (4,4′-R2bipy, where R is MeO, Me, H, NO2) – on both the photo- and electro-luminescence features of a series of heteroleptic copper(I) complexes – i.e., [Cu(N^N)(P^P)]+ where N^N and P^P ligands are R2bipy and Xantphos, respectively. By virtue of a comprehensive photophysical, theoretical, and thin-film lighting device – i.e., light-emitting electrochemical cells (LECs) – investigation, we note a clear relationship between the σp and the photo- and electro-luminescence parameters, such as photoluminescence quantum yields, excited-state…
The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substan…
2019
Removal of petroleum products from contaminated soil is a long-term process requiring attention and constant monitoring. The aim of this study was to determine the effect of Fyre-Zyme enzyme preparation and/or calcium carbonate on microbiological changes and conversion of n-aliphatic hydrocarbons in soil contaminated of petroleum-derived substances. The material for testing was soil contaminated with petroleum substances. The total concentration of n-alkanes with a C8–C40 chain length was 420.1 mg·kg−1 DM. The pot tests were carried out by introducing stimulators. As a decomposition promoter for n-alkanes in contaminated soil, a 6% water solution of Fyre-Zyme and/or 1% sterile CaCO3 was use…
Effects of l-Carnitine in Patients with Autism Spectrum Disorders: Review of Clinical Studies
2019
Carnitine is an amino acid derivative, which plays several important roles in human physiology, in the central nervous system, and for mitochondrial metabolism, in particular. Altered carnitine metabolic routes have been associated with a subgroup of patients with autism spectrum disorders (ASD) and could add to the pathophysiology associated with these disorders. We review the current evidence about the clinical effects of carnitine administration in ASD in both non-syndromic forms and ASD associated with genetic disorders. Two randomized clinical trials and one open-label prospective trial suggest that carnitine administration could be useful for treating symptoms in non-syndromic ASD. Th…
Localization from inertial data and sporadic position measurements
2020
International audience; A novel estimation strategy for inertial navigation in indoor/outdoor environments is proposed with a specific attention to the sporadic nature of the non-periodic measurements. After introducing the inertial navigation model, we introduce an observer providing an asymptotic estimate of the plant state. We use a hybrid dynamical systems representation for our results, in order to provide an effective, and elegant theoretical framework. The estimation error dynamics with the proposed observer shows a peculiar cascaded interconnection of three subsystems (allowing for intuitive gain tuning), with perturbations occurring either on the jump or on the flow dynamics (depen…
Characterisation of the magmatic signature in gas emissions from Turrialba Volcano, Costa Rica
2014
The equilibrium composition of volcanic gases with their magma is often overprinted by interaction with a shallow hydrothermal system. Identifying the magmatic signature of volcanic gases is critical to relate their composition to properties of the magma (temperature, fO2, gas-melt segregation depth). We report measurements of the chemical composition and flux of the major gas species emitted from Turrialba Volcano during March 2013. Measurements were made of two vents in the summit region, one of which opened in 2010 and the other in 2012. We determined an average SO2 flux of 5.2 ± 1.9 kg s-1 using scanning ultraviolet spectroscopy, and molar proportions of H2O, CO2, SO2, HCl, CO and H2 ga…