Ultrafast charge delocalization dynamics in aqueous electrolytes: New insights from Auger electron spectroscopy

We review the basic principles of ultrafast charge delocalization phenomena in aqueous electrolytes following core-level photoionization and resonant core-level excitations, and describe how these processes can be probed using Auger electron spectroscopy. The use of the core-hole clock method to extract dynamical information from Auger spectra is described. By a number of examples we demonstrate how the efficiency for ultrafast charge transfer phenomena on the low femtosecond timescale is determined not only by factors such as charge, polarizability and solvated radius of the ionic solutes but also by the dominant interactions of the ionized site with its surroundings in the intermediate state. (C) 2012 Elsevier B.V. All rights reserved

Free clusters studied by core-level spectroscopies

In this review we describe the development and current status of free clusters studied using core-level spectroscopies. This topic ranges from simple model systems, such as rare gas clusters, to molecular clusters, and clusters of solids, held together by ionic, covalent and metallic bonding. (C) 2009 Elsevier B.V. All rights reserved

Explanatory Factors for Small Firms’ Sustainable Growth : Developing an Assessment Model for Established SMEs

This paper investigates factors that can explain sustainable growth in established small and medium-sized enterprises (SMEs). Deducted from previous research, tentative explanatory factors serve as a base for constructing a model for assessment of an SME’s growth potential. Applying the assessment model on 154 companies did not result in a clear pattern of factors that are most important for long-term profitable business development and growth, but showed important overall differences between financially strong companies and weaker ones. These results can be a base for further refinement of factors that should be taken into account for sustainable growth in SMEs

Alcohols at the aqueous surface: chain length and isomer effects

Surface-active organic molecules at the liquid-vapor interface are of great importance in atmospheric science. Therefore, we studied the surface behavior of alcohol isomers with different chain lengths (C4-C6) in aqueous solution with surface-and chemically sensitive X-ray photoelectron spectroscopy (XPS), which reveals information about the surface structure on a molecular level. Gibbs free energies of adsorption and surface concentrations are determined from the XPS results using a standard Langmuir adsorption isotherm model. The free energies of adsorption, ranging from around -15 to -19 kJ mol(-1) (C4-C6), scale linearly with the number of carbon atoms within the alcohols with Delta G(Ads) per-CH2-approximate to -2 kJ mol(-1.) While for the linear alcohols, surface concentrations lie around 2.4 x 10(14) molecules per cm(2) at the bulk concentrations where monolayers are formed, the studied branched alcohols show lower surface concentrations of around 1.6 x 10(14) molecules per cm(2), both of which are in line with the molecular structure and their orientation at the interface. Interestingly, we find that there is a maximum in the surface enrichment factor for linear alcohols at low concentrations, which is not observed for the shorter branched alcohols. This is interpreted in terms of a cooperative effect, which we suggest to be the result of more effective van der Waals interactions between the linear alcohol alkyl chains at the aqueous surface, making it energetically even more favorable to reside at the liquid-vapor interface

Parental involvement in the adaptation of 2-3 year old children to a Pre-school educational establishment

Darba autore: Ieva Bīriņa Kvalifikācijas darba temats: “Vecāku līdzdalība 2 – 3 gadus vecu bērnu adaptācijā pirmsskolas izglītības iestādē.” Darbā izvirzītais mērķis ir teorētiski un praktiski izpētīt un analizēt 2 – 3 gadus vecu bērnu adaptāciju pirmsskolas izglītības iestādē un vecāku līdzdalību šajā procesā. Atbilstoši pētījuma mērķim izvirzīti pētījuma uzdevumi: 1.Analizēt teorētisko literatūru par adaptāciju. 2.Izpētīt vecāku līdzdalības iespējas adaptācijas periodā, 3.Veikt praktisko pētījumu par bērna adaptāciju un vecāku līdzdalību šajā procesā. Pētījuma teorētiskā daļa balstās uz G. Ancānes, D. Boulbija, R. Kempbela, D. Dzinteres, E. Eriksona, S. Gailumas, I. Puškareva, A. Golubevas un citu autoru teorētiskajām atziņām. Pētījuma praktiskajā daļā autore pētīja 2 – 3 gadus vecu bērnu adaptāciju un vecāku līdzdalību šajā procesā. Galvenais uzsvars tika likts, kā vecāki iesaistās bērna adaptācijā, lai bērnam to atvieglotu. Pētījuma gaitā tika novērota bērnu un viņu vecāku savstarpējā sadarbība, kā arī analizēti vecāku anketēšanā iegūtie rezultāti. Kvalifikācijas darbam ir 3 nodaļas, 10 tabulas, 4 pielikumi. Darba apjoms ir 57 lpp., izmantotas 20 literatūras vienības. Atslēgas vārdi: adaptācija, vecāku līdzdalība, pirmsskolas izglītības iestāde, 2 – 3 gadus veci bērni. Author of work: Ieva Birina Theme of the Qualification paper: “Parental involvement in the adaptation of 2-3 year old children to a pre-school educational establishment.” The aim of the paper is to theoretically and practically research and analyse 2-3 year old children's adaptation process in pre-school education establishment and parental involvement in this process. Such research tasks were set according to the research aim: 1.Analyse theoretical sources about adaptation process. 2.Research possibilities for parental involvement in the adaptation process. 3.Carry out practical research about child's adaptation and parental involvement in this process. The theoretical part of the research is based on theoretical quotes of such authors as G. Ancāne, J. Bowlby, R. Campbell, D. Dzintere, E. Erikson, S. Gailuma, I. Puškarevs, A. Golubeva and others. Reserach about child's adaptation and parental involvement in this process has been carried out in the practical part. The main emphasis was put on the fact how parents involve themselves in child's adaptation process in order to ease it. Cooperation of a child and his parents was observed as well as results of parents' questionnaires were analysed during the research. The Qualification paper consists of 3 chapters, 10 tables, 4 attachments. The volume of the paper is 57 pages; 20 literature sources were used. Keywords: adaptation, parental involvement, preschool educational institution, children 2 - 3 years old

Core level photoelectron spectroscopy probed heterogeneous xenon/neon clusters

Binary rare gas clusters; xenon and neon which have a significant contrariety between sizes, produced by a co-expansion set up and have been studied using synchrotron radiation based x-ray photoelectron spectroscopy. Concentration ratios of the heterogeneous clusters; 1%, 3%, 5% and 10% were controlled. The core level spectra were used to determine structure of the mixed cluster and analyzed by considering screening mechanisms. Furthermore, electron binding energy shift calculations demonstrated cluster aggregation models which may occur in such process. The results showed that in the case of low mixing ratios of 3% and 5% of xenon in neon, the geometric structures exhibit xenon in the center and xenon/neon interfaced in the outer shells. However, neon cluster vanished when the concentration of xenon was increased to 10%

Succinic acid in aqueous solution: connecting microscopic surface composition and macroscopic surface tension

The water-vapor interface of aqueous solutions of succinic acid, where pH values and bulk concentrations were varied, has been studied using surface sensitive X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulations. It was found that succinic acid has a considerably higher propensity to reside in the aqueous surface region than its deprotonated form, which is effectively depleted from the surface due to the two strongly hydrated carboxylate groups. From both XPS experiments and MD simulations a strongly increased concentration of the acid form in the surface region compared to the bulk concentration was found and quantified. Detailed analysis of the surface of succinic acid solutions at different bulk concentrations led to the conclusion that succinic acid saturates the aqueous surface at high bulk concentrations. With the aid of MD simulations the thickness of the surface layer could be estimated, which enabled the quantification of surface concentration of succinic acid as a multiple of the known bulk concentration. The obtained enrichment factors were successfully used to model the surface tension of these binary aqueous solutions using two different models that account for the surface enrichment. This underlines the close correlation of increased concentration at the surface relative to the bulk and reduced surface tension of aqueous solutions of succinic acid. The results of this study shed light on the microscopic origin of surface tension, a macroscopic property. Furthermore, the impact of the results from this study on atmospheric modeling is discussed

No signature of contact ion pairs in the K 2p Auger spectra of highly concentrated potassium halide solutions

Possible ion pair formation in highly concentrated aqueous potassium halide solutions (fluoride, chloride, and bromide) has been investigated using Auger electron spectroscopy. The potassium Auger spectra exhibit features at high kinetic energy which are related to final states with vacancies on the potassium ion and a neighbouring water molecule. The potassium ion could possibly associate with a halide ion as well, giving rise to additional final states with a vacancy on the halide instead of a water molecule which should give rise to separable spectral features. The necessity of close proximity of the ions for such decays to occur would be strong evidence that contact ions pairs are present in the solution, but no features related to final states involving the anion were observed