Search results for "Abstract"

Modelling the Reverse ElectroDialysis process with seawater and concentrated brines

2012

Technologies for the exploitation of renewable energies have been dramatically increasing in number, complexity and type of source adopted. Among the others, the use of saline gradient power is one of the latest emerging possibilities, related to the use of the osmotic/chemical potential energy of concentrated saline solutions. Nowadays, the fate of this renewable energy source is intrinsically linked to the development of the pressure retarded osmosis and reverse electrodialysis technologies. In the latter, the different concentrations of two saline solutions is used as a driving force for the direct production of electricity within a stack very similar to the conventional electrodialysis …

Simple variable-volume injector for flow-injection systems

1990

Abstract A simple and versatile variable-volume injector is described for the introduction of samples in flow-injection systems. The device delivers precisely and reproducibly (usually r.s.d.

New approach to condensed pyrid-2-ones

2002

We wish to report a simple procedure for the preparation of 5-substituted-thienopyridin-7-ones and 7-substituted-1,6-naphthyridin-5(6H)-ones, in good yields, from the dianions of 3-methylthiophene-2-carboxylic and 2-methylnicotinic acids on treatment with nitriles. Brun Sanchez, Eva Maria, Eva.M.Brun@uv.es ; Gil Grau, Salvador, Salvador.Gil@uv.es ; Parra Alvarez, Margarita, Margarita.Parra@uv.es

On the electronic structure of a dianion, a radical anion, and a neutral biradical (HB)11CCCC(BH)11 carborane dimer

2009

Abstract The electronic structure of a neutral, a radical anion, and a dianion carborane dimer connected via an acetylenic bridge unit (HB) 11 C C C C(BH) 11 is analyzed by quantum chemical methods. Geometries, relative stabilities, and singlet–triplet gaps are determined in the neutral and dianion species for the lowest-lying singlet and triplet states and for the doublet ground state in the radical anion. As for the recently studied biradical compounds derived from o -carborane, m -carborane and p -carborane [J. Chem. Theory Comput. 4 (2008) 1338] via double hydrogen abstraction, the neutral dimeric compound displays a biradical ground-state structure in which both singlet and triplet sta…

On the Reaction of (tBu2SnO)3 with Organochlorosilanes. Simple Formation of [(tBu2SnO)2(tBu2SiO)]

2008

ELECTROCHEMICAL CONVERSION OF DICHLOROACETIC ACID TO CHLOROACETIC ACID IN A MICROFLUIDIC STACK AND IN A SERIES OF MICROFLUIDIC REACTORS

2015

The electrochemical conversion of dichloroacetic acid to chloracetic acid was performed in three different micro devices: a simple micro fluidic cell; a microfluidic stack equipped with various electrode chambers in series and three micro fluidic cells in series. The electrochemical synthesis of chloracetic acid was performed successfully with high yields and selectivity under a single-pass mode without supporting electrolyte at low cell voltages. An increase of the productivity and of the final concentration of the target product was achieved by using a stack with two or three electrode chambers in series. The utilization of three micro reactors in series open interesting new perspectives,…

Extension of Walsh's rules to more general systems

1972

It is demonstrated that location of hydrogen atoms within bonding distance of a simple triatomic molecule can alter the order of energy levels relative to that of the parent system without significantly changing the behavior of the orbital energies under geometrical variation. As a result the ground state electronic configurations of H n AB2 systems often differ from those of triatomics with the same number of electrons and this fact is shown to be directly responsible for the existence of such distinctive geometrical structures as those possessed by cyclopropane, cyclopropyl and allyl cations and cyclopropene. Thus the familiar prescription of Walsh's rules which states that isoelectronic …

New aspects of scattering and absorbing properties of atmospheric aerosol particles

1972

Abstract Knowledge of the scattering and absorbing processes of the atmospheric aerosol particles in the solar wavelength range is necessary in order to calculate the energy balance of the atmosphere. Both of these depend on the relative humidity of the air. Until now little was known of the behavior of the particles. This paper shows experimental and theoretical results of the real and imaginary part of the refractive index of the aerosol particles at different relative humidities.

First aid in dental trauma in pediatric age

2014

The knowledge of the right management of dental traumas is very important for the pediatrician due both to their high incidence in this age group and to prevent further pathologic events related. Several studies indicate that in industrialized countries, about one in five children have had a traumatic dental injury to permanent teeth before leaving school. Prevalence of injured teeth presented in the literature varies from 10 to 51% [1]. The pediatrician, more than any other health professionals, should have the necessary knowledge to ensure correct and professional advices for all issues concerning the child's health [2]. Most of the available literature emphasizes that awareness of the co…

High-resolution gas chromatographic-mass spectrometric determination of neutral chlorinated aromatic sulphur compounds in stack gas samples

1993

Abstract Four stack gas samples from waste incineration were analysed by high-resolution GC-MS for neutral chlorinated aromatic sulphur compounds such as polychlorinated dibenzothiophenes, thianthrenes and diphenyl sulphides. Samples were analysed tentatively also for some methylated derivatives of these compounds. The stack gas samples had earlier been found to contain some tri- and tetrachlorodiphenyl sulphides. Two of the stack gas samples contained tetra- and pentachlorodibenzothiophenes. One sample was strongly suspected to contain some tri- and tetrachlorothianthrenes in low concentrations. No methylated derivatives of these compounds could be found. Polychlorothianthrenes, some polyc…