Search results for "chemistry [Water]"
showing 10 items of 2369 documents
Power Losses Minimization for Optimal Operating Maps in Power-Split HEVs: A Case Study on the Chevrolet Volt
2021
The power-split architecture is the most promising hybrid electric powertrain. However, a real advantage in energy saving while maintaining high performance can be achieved only by the implementation of a proper energy management strategy. This requires an optimized functional design before and a comprehensive analysis of the powertrain losses after, which could be rather challenging owing to the constructive complexity of the power-split transmission, especially for multi-mode architecture with multiple planetary gearing. This difficulty was overcome by a dimensionless model, already available in the literature, that enables the analysis of any power-split transmission, even in full electr…
Greening the wastes
2019
Problems associated with analytical waste toxicity and waste treatment are reviewed in the frame of the water treatment, being collected a series of models, from the big-scale treatment of waste waters and adapted to the effluents generated during sample analysis. In fact to move from wastes to clean or no-contaminant wastes is a way from greening those methods in which any sample treatment and the use of reagents and solvents cannot be avoided. The last contributions in the field have been taken into account in this study and future trends have been proposed.
Spatial models for monitoring the spatio-temporal evolution of ashes after fire-a case study of a burnt grassland in Lithuania
2013
Ash thickness is a key variable in the protection of soil against erosion agents after planned and unplanned fires. Ash thickness measurements were conducted along two transects (flat and sloping areas) following a grided experimental design. In order to interpolate data with accuracy and identify the techniques with the least bias, several interpolation methods were tested in the grided plot. Overall, the fire had a low severity. However, the fire significantly reduced the ground cover, especially on sloping areas, owing to the higher fire severity and/or less biomass previous to the fire. Ash thickness depended on fire severity and was thin where fire severity was higher and thicker in lo…
OpenMolcas: From Source Code to Insight
2019
In this article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multico…
Higher-order Hamilton–Jacobi perturbation theory for anisotropic heterogeneous media: dynamic ray tracing in Cartesian coordinates
2018
With a Hamilton–Jacobi equation in Cartesian coordinates as a starting point, it is common to use a system of ordinary differential equations describing the continuation of first-order derivatives of phase-space perturbations along a reference ray. Such derivatives can be exploited for calculating geometrical spreading on the reference ray and for establishing a framework for second-order extrapolation of traveltime to points outside the reference ray. The continuation of first-order derivatives of phase-space perturbations has historically been referred to as dynamic ray tracing. The reason for this is its importance in the process of calculating amplitudes along the reference ray. We exte…
Spectroscopic methods applied to zircon
2003
Natural and synthetic (pure and doped) zircon (ZrSiO4) have been studied with a variety of spectroscopic techniques. These techniques are based on different physical phenomena, for instance transitions between spin states of nuclei and electrons, energetic transitions of valence electrons, intra-molecular vibrations, or vibrations of atoms and molecular units in the lattice. All of the diverse spectroscopic techniques, however, have in common that they probe energy differences between a ground and excited states, mostly upon interaction of the mineral with incident radiation. Such interactions are not only determined by the excited elementary particles or molecules themselves but depend gre…
Spring to summer changes in the West African monsoon through NCEP/NCAR reanalyses (1968–1998)
2002
[1] This article focuses on the spring to summer evolutions of the West African monsoon from an energetic point of view; it uses NCEP/NCAR reanalyses along with observed and simulated rainfall data over the period 1968–1998. The results show that the West African monsoon can be viewed as a coupled ocean-atmosphere-land system phased with the zenithal evolution of solar radiation which maintains its thermally direct circulation by pumping, from the surface, enthalpy mainly in spring and latent energy in summer. In this context the horizontal energy gradients in the boundary layer play a key role during the spring to summer transition. At the beginning of spring, the moist static energy (MSE)…
Searching the most appropriate sample pretreatment for the elemental analysis of wines by inductively coupled plasma-based techniques.
2008
Different sample preparation methods were evaluated for the simultaneous multielement analysis of wine samples by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Microwave-assisted digestion in closed vessel, thermal digestion in open reactor, and direct sample dilution were considered for the determination of Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Y, Mo, Cd, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Tl, Pb, and Bi in 12 samples of red wine from Valencia and Utiel-Requena protected designation of origin. ICP-MS allows the determination of 17 elements in most…
Synthesis, stability and spectral behavior of fluorogenic sulfone-pyronin and sulfone-rosamine dyes
2018
International audience; The first synthesis of sulfone-pyronin and sulfone-rosamine dyes bearing optically tunable primary amino groups (acting as fluorogenic centers) is presented. Sulfone analogs of xanthene-based fluorophores have recently been highlighted as a new class of near-infrared (NIR) fluorescent dyes (Liu et al. ACS Appl Mater Interfaces 2016; 8(35):22953-62), and the availability of fluorogenic derivatives is essential for the rapid construction of “turn-on” reactive probes for chemoselective bioimaging. However, these fluorescent anilines have been found to be unstable in aqueous physiological conditions due to the marked electrophilicity of their meso-position and hence its …
New evidence of mantle heterogeneity beneath the Hyblean Plateau (southeast Sicily, Italy) as inferred from noble gases and geochemistry of ultramafi…
2012
Abstract We analyzed major and trace elements, Sr and Nd isotopes in ultramafic xenoliths in Miocenic age Hyblean diatremes, along with noble gases of CO2-rich fluid inclusions hosted in the same products. The xenoliths consist of peridotites and pyroxenites, which are considered to be derived from the upper mantle. Although the mineral assemblage of peridotites and their whole-rock abundance of major elements (e.g., Al2O3 = 0.8–1.5 wt.%, TiO2 = 0.03–0.08 wt.%) suggest a residual character of the mantle, a moderate enrichment in some incompatible elements (e.g., LaN/YbN = 9–14) highlights the presence of cryptic metasomatic events. In this context a deep silicate liquid is considered the me…