Viscosimetric studies of water and water-salt solution of polyethylene glycol

The complex analysis of a state of PEG macromolecules of various molecular weights in water and water-salt solutions is carried out. Temperature factors, the constants characterizing intermolecular interaction in these systems are defined. The intrinsic viscosity is defined with the use of the various linear extrapolation equations. Influence of temperature and electrolytes on thermodynamic properties in PEG – water and PEG – water-salt solution systems is shown

Application of paraffin emulsion as apolar co-reagent during sylvinite flotation process

The research is devoted to finding more affordable apolar reagent paraffinic base for their use in the process of potash ore flotation, as well as improve the form in which the reagent is introduced into the flotation process. Found that the introduction of paraffinic oil flotation system in the form of emulsions provides extraction of potassium chloride at a level comparable to the same period of the industrial process

THE FIRST EXPERIENCE WITH TISSUCOL AT MOSCOW CITY CANCER HOSPITAL SIXTY-TWO

The paper describes the first experience with the fibrin sealant Tissucol at Moscow City Cancer Hospital Sixty-Two. The authors used this agent in different clinical situations. However, Tissucol showed the highest efficacy in arresting long-term severe lymphorrhea. The described clinical case clearly demonstrates the abilities of this agent and allows it to be recommended for use in other areas of oncology

Reliability of AlGaN/GaN high electron mobility transistors on low dislocation density bulk GaN substrate: Implications of surface step edges

To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gateleakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths.Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges ofsurface steps

Investigation of cracks in GaN films grown by combined hydride and metal organic vapor-phase epitaxial method

Cracks appeared in GaN epitaxial layers which were grown by a novel method combining metal organic vapor-phase epitaxy (MOCVD) and hydride vapor-phase epitaxy (HVPE) in one chamber. The origin of cracks in a 22-μm thick GaN film was fully investigated by high-resolution X-ray diffraction (XRD), micro-Raman spectra, and scanning electron microscopy (SEM). Many cracks under the surface were first observed by SEM after etching for 10 min. By investigating the cross section of the sample with high-resolution micro-Raman spectra, the distribution of the stress along the depth was determined. From the interface of the film/substrate to the top surface of the film, several turnings were found. A large compressive stress existed at the interface. The stress went down as the detecting area was moved up from the interface to the overlayer, and it was maintained at a large value for a long depth area. Then it went down again, and it finally increased near the top surface. The cross-section of the film was observed after cleaving and etching for 2 min. It was found that the crystal quality of the healed part was nearly the same as the uncracked region. This indicated that cracking occurred in the growth, when the tensile stress accumulated and reached the critical value. Moreover, the cracks would heal because of high lateral growth rate

Viscosimetric studies of water and water-salt solution of polyethylene glycol

The complex analysis of a state of PEG macromolecules of various molecular weights in water and water-salt solutions is carried out. Temperature factors, the constants characterizing intermolecular interaction in these systems are defined. The intrinsic viscosity is defined with the use of the various linear extrapolation equations. Influence of temperature and electrolytes on thermodynamic properties in PEG – water and PEG – water-salt solution systems is shown

Project and Work Organization in Solidarity Economy: A first Approach According to Production Engineering

Part 1: Knowledge-Based SustainabilityInternational audienceThis article presents the possible contributions of Production Engineering to solidarity economy as regards projects and organization of work. The authors present logistics as the main channel of introduction to planning and organizing solidarity economy, seeking to show that the participation of Production Engineering leads to a breakage of some strains marked by neoliberalism, making evident the need of serious ecological concerns within the scope of the projects in that sector towards a cleaner production. The authors also point out the impossibility of development of solidarity economy programs without well mapped processes that include environmental impact evaluations and environmental education as pillars of sustainability in any development program

Application of paraffin emulsion as apolar co-reagent during sylvinite flotation process

The research is devoted to finding more affordable apolar reagent paraffinic base for their use in the process of potash ore flotation, as well as improve the form in which the reagent is introduced into the flotation process. Found that the introduction of paraffinic oil flotation system in the form of emulsions provides extraction of potassium chloride at a level comparable to the same period of the industrial process

Identification of the gallium vacancy-oxygen pair defect in GaN

Cation vacancies like V-Ga, V-Al and their complexes with oxygen are predicted to be abundant in III-nitrides and to play an important role in nonradiative recombination. Appearing in triple or double negatively charged states, they are not paramagnetic and have not so far been detected by magnetic resonance even under illumination. In this Brief Report, we demonstrate an efficient way to make cation vacancy defects in GaN detectable by electron paramagnetic resonance and present our identification of the VGaON pair in GaN which is the model material for the III-nitrides and their alloys