Study of self-assembly and degree of ionization of block copolymers using transmission electron microscopy and molecular simulations

Responsive systems, such as block copolymers with solvent-affine blocks, can undergo self-assembly into structures like micelles or vesicles. These assem- blies are highly sensitive to slight changes in external conditions, like pH or temperature, leading to the formation or dissolution of micelles. When one of the polymer blocks is a weak polyelectrolyte, its degree of ionization depends not only on the external conditions but also on the association state. This study focuses on investigating the size and degree of ionization of micellar struc- tures formed by polymer chains containing thermoresponsive and pH-responsive blocks. The investigation combines high-resolution transmission electron mi- croscopy and Hamiltonian Monte Carlo simulations to provide a comprehensive understanding of these micellar structures. 1Responzivní systémy blokových kopolymerů, kterých bloky mají různou afinitu ke zkoumanému rozpouštědlu mohou vytvářet struktury jako micely nebo vezikuly. Tyhle struktury jsou senzitivní ke změnám vnějších podmínek jakými jsou pH a teplota. Tyto změny často vedou k formaci nebo rozkladu micel. Pokud je jedním z bloků slabý polyelektrolyt, stupeň ionizace závisí nejenom na vnějších podmínkách, ale taktéž na konformaci řetězců. Táto práce zahrnuje studium velikosti a stupně ionizace micelárních struktur a linearních řetězců kopolymeru obsahujícího termosenzitivní a pH responzivní bloky pomocí vysokorozlišovací transmisní elektronové mikroskopie a hamiltonianských Monte Carlo simulací. 1Katedra fyzikální a makromol. chemieDepartment of Physical and Macromolecular ChemistryFaculty of SciencePřírodovědecká fakult

Vállalkozók túlélési stratégiái: Egy angol-magyar összehasonlító kutatás tapasztalatai

Tanulmányuk alapjául szolgáló kutatásukban a szerzők annak megválaszolására tettek kísérletet, hogy mit tett a vállalkozó vagy ügyvezető tulajdonos vállalkozása fennmaradásáért, azaz milyen túlélési stratégiát folytatott. Módszerük az interjútechnika volt, melynek keretében négy tematikus kérdéscsoportot alakítottak ki, majd az interjúkat elemezték, értelmezték, s osztályozták az észrevételeket

Influence of Flux and Related Factors on Intermetallic Layer Growth within SAC305 Solder Joints

Flux contained in solder paste significantly affects the process of solder joint creation during reflow soldering, including the creation of an intermetallic layer (IML). This work investigates the dependence of intermetallic layer thickness on ROL0 / ROL1 flux classification, glossy or matt solder mask, and OSP / HASL / ENIG soldering pad surface finish. Two original SAC305 solder pastes differing only in the used flux were chosen for the experiment. The influence of multiple reflows was also observed. The intermetallic layer thicknesses were obtained by the image analysis of micro-section images. The flux type proved to have a significant impact on the intermetallic layer thickness. The solder paste with ROL1 caused an increase in IML thickness by up to 40% in comparison to an identical paste with ROL0 flux. Furthermore, doubling the roughness of the solder mask has increased the resulting IML thickness by 37% at HASL surface finish and by an average of 22%

Management of multiple sclerosis patients in central European countries: current needs and potential solutions

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Study of self-assembly and degree of ionization of block copolymers using transmission electron microscopy and molecular simulations

Responsive systems, such as block copolymers with solvent-affine blocks, can undergo self-assembly into structures like micelles or vesicles. These assem- blies are highly sensitive to slight changes in external conditions, like pH or temperature, leading to the formation or dissolution of micelles. When one of the polymer blocks is a weak polyelectrolyte, its degree of ionization depends not only on the external conditions but also on the association state. This study focuses on investigating the size and degree of ionization of micellar struc- tures formed by polymer chains containing thermoresponsive and pH-responsive blocks. The investigation combines high-resolution transmission electron mi- croscopy and Hamiltonian Monte Carlo simulations to provide a comprehensive understanding of these micellar structures.

Assessment and Prediction of Complex Industrial Steam Network Operation by Combined Thermo-Hydrodynamic Modeling

Steam network operation stability and reliability is vital for any industrial branch. A combined steam network model comprising a balance and a coupled thermo-hydrodynamic model, including seasonal variations impact and system specificities, is presented. A balance model can readily be used by a refinery’s operators. The thermo-hydrodynamic model identifies system bottlenecks and cold spots and evaluates proposed operation and investment measures including heat loss reduction. A three-pressure levels refinery steam network served for model testing and validation. Balance model results reveal significant misbalance in steam production and consumption, reaching 30.5% in the low-pressure steam system, and heat balance differences in the range of 9.2% to 29.5% on individual pressure levels, attributable both to flow measurement accuracy issues and to heat losses. The thermo-hydrodynamic model results differ from the measured steam parameters by less than 5% (temperature) and by less than 4% (pressure), respectively, with the estimated operational insulation heat conductivity exceeding 0.08 W/m/K. Its comparison with that of 0.03 W/m/K for dry insulation material yields the need for pipelines re-insulation and a partial revamp of the steam network. The model is sufficiently general for any type of industry, pursuing the goal of cleaner and energy-efficient steam transport and consumption