Exact Soliton-like Solutions of the Radial Gross-Pitaevskii Equation

We construct exact ring soliton-like solutions of the cylindrically symmetric (i.e., radial) Gross- Pitaevskii equation with a potential, using the similarity transformation method. Depending on the choice of the allowed free functions, the solutions can take the form of stationary dark or bright rings whose time dependence is in the phase dynamics only, or oscillating and bouncing solutions, related to the second Painlev\'e transcendent. In each case the potential can be chosen to be time-independent.Comment: 8 pages, 7 figures. Version 2: stability analysis of the dark solutio

Novel approach to determination of sorption in pervaporation process: a case study of isopropanol dehydration by polyamidoimideurea membranes

Development of novel membranes with optimal performance, selectivity, and stability is a key research area in membrane technology. In the present work aromatic polyamidoimideurea (PAIU) is synthesized and tested as promising membrane material for separation of water and alcohol mixtures. The PAIU membrane structure, density, and transport properties are studied. Mass transfer of water and isopropanol through the membrane is estimated by sorption and pervaporation tests to determine equilibrium sorption degree, diffusion coefficients, flux through the membrane, and separation factor. Two techniques of sorption study from liquid and from vapor phases are used as novel approach to experimental study of mass transfer. The vapor sorption calorimetry permits to analyze the behavior of the polymer material in sorption process. In pervaporation of water-isopropanol mixture, almost pure water mainly permeates through PAIU membrane. To improve the performance, a double layer membrane containing a thin PAIU layer on the surface of porous poly(phenylene oxide) support is developed. The double layer membrane is extremely effective in dehydration of isopropanol.Russian Science Foundation (RSF): grant 16-13-10164

Adhesive and conformational behaviour of mycolic acid monolayers

We have studied the pH-dependent interaction between mycolic acid (MA) monolayers and hydrophobic and hydrophilic surfaces using molecular (colloidal probe) force spectroscopy. In both cases, hydrophobic and hydrophilic monolayers (prepared by Langmuir-Blodgett and Langmuir-Schaefer deposition on silicon or hydrophobized silicon substrates, respectively) were studied. The force spectroscopy data, fitted with classical DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory to examine the contribution of electrostatic and van der Waals forces, revealed that electrostatic forces are the dominant contribution to the repulsive force between the approaching colloidal probe and MA monolayers. The good agreement between data and the DLVO model suggest that beyond a few nm away from the surface, hydrophobic, hydration, and specific chemical bonding are unlikely to contribute to any significant extent to the interaction energy between the probe and the surface. The pH-dependent conformation of MA molecules in the monolayer at the solid-liquid interface was studied by ellipsometry, neutron reflectometry, and with a quartz crystal microbalance. Monolayers prepared by the Langmuir-Blodgett method demonstrated a distinct pH-responsive behaviour, while monolayers prepared by the Langmuir-Schaefer method were less sensitive to pH variation. It was found that the attachment of water molecules plays a vital role in determining the conformation of the MA monolayers. (C) 2010 Elsevier B.V. All rights reserved

Preventive interventions in families with parental depression: children’s psychosocial symptoms and prosocial behaviour

The aim is to document the effectiveness of a preventive family intervention (Family Talk Intervention, FTI) and a brief psychoeducational discussion with parents (Let’s Talk about the Children, LT) on children’s psychosocial symptoms and prosocial behaviour in families with parental mood disorder, when the interventions are practiced in psychiatric services for adults in the finnish national health service. Patients with mood disorder were invited to participate with their families. Consenting families were randomized to the two intervention groups. The initial sample comprised 119 families and their children aged 8–16. Of these, 109 completed the interventions and the baseline evaluation. Mothers and fathers filled out questionnaires including standardized rating scales for children’s symptoms and prosocial behaviour at baseline and at 4, 10 and 18 months post-intervention. The final sample consisted of parental reports on 149 children with 83 complete data sets. Both interventions were effective in decreasing children’s emotional symptoms, anxiety, and marginally hyperactivity and in improving children’s prosocial behaviour. The FTI was more effective than the LT on emotional symptoms particularly immediately after the intervention, while the effect of the LT emerged after a longer interval. The study supports the effectiveness of both interventions in families with depressed parents. The FTI is applicable in cultural settings other than the USA. Our findings provide support for including preventive child mental health measures as part of psychiatric services for mentally ill parents