Viscosity Measurements of Dilute Poly(2-ethyl-2-oxazoline) Aqueous Solutions Near Theta Temperature Analyzed within the Joint Rouse-Zimm Model

The steady-state shear viscosity of low-concentrated Poly(2-ethyl-2-oxazoline) (PEOX) aqueous solutions is measured near the presumed theta temperature using the falling ball viscometry technique. The experimental data are analyzed within the model that joins the Rouse and Zimm bead-spring theories of the polymer dynamics at the theta condition, which means that the polymer coils are considered to be partially permeable to the solvent. The polymer characteristics thus depend on the draining parameter h that is related to the strength of the hydrodynamic interaction between the polymer segments. The Huggins coefficient was found to be 0.418 at the temperature 20°C, as predicted by the theory. This value corresponds to h = 2.92, contrary to the usual assumption of the infinite h. This result indicates that the theta temperature for the PEOX water solutions is 20°C rather than 25°C in the previous studies. The experimental intrinsic viscosity is well described coming from the Arrhenius equation for the shear viscosity

Analysis of selected personnel activities in a medium-sized company

My bachelor thesis deals with the evaluation system for workers and the follow-up education system for workers in a medium-sized company. The theoretical part focuses on the generally defined terms and facts related to the evaluation and education for workers. The practical part contains a description and SWOT analysis of the evaluation and education system for workers in a particular company

Online marketing of the Language centre Laurus

This master's thesis deals with online marketing of the Language centre Laurus. The main objectives of this work are the assessment of the current state of online marketing of the Language centre Laurus, evaluation of the effectiveness of used communication channels, and recommendations leading to higher commercial success of the web pages. The theoretical part consists of three blocks. The first chapter is devoted to web sites, information architecture, usability and accessibility. The next chapter introduces the possibility of building traffic on web pages, and the third part consists of analysis of the competition. The following chapter includes methodology in which the used tools and procedures of the analysis are introduced. The practical part of the thesis includes introduction and analysis of the online marketing activities of the Language centre Laurus in that is the central part composed of the PPC advertising, SEO analysis and user testing of the web pages. The conclusion of the practical part includes the evaluation of the online marketing activities of the Language centre Laurus and recommendations for further procedures in the field of online marketing activities of the centre

Game frontier

In my bachelor thesis I deal with concept of play and toy. Their origin, proces and impact on the user. The goal is to offer a product, that can provide benefits of constructive play and overall playful behavior in an accessible and easy way

Immunobiological Activity of Synthetically Prepared Immunodominant Galactomannosides Structurally Mimicking Aspergillus Galactomannan

The study is oriented at the in vitro evaluation of the immunobiological activity and efficacy of synthetically prepared isomeric pentasaccharides representing fragments of Aspergillus fumigatus cell-wall galactomannan and containing β-(1→5)-linked tetragalactofuranoside chain attached to O-6 (GM-1) or O-3 (GM-2) of a spacer-armed mannopyranoside residue. These compounds were studied as biotinylated conjugates which both demonstrated immunomodulatory activities on the RAW 264.7 cell line murine macrophages as in vitro innate immunity cell model. Immunobiological studies revealed time- and concentration-dependent efficient immunomodulation. The proliferation of RAW 264.7 macrophages was induced at higher concentration (100 µg/mL) of studied glycoconjugates and longer exposure (48 h), with more pronounced efficacy for GM-1. The increase of proliferation followed the previous increase of IL-2 production. The cytokine profile of the macrophages treated with the glycoconjugates was predominantly pro-inflammatory Th1 type with significant increase of TNFα, IL-6, and IL-12 release for both glycoconjugates. The RAW 264.7 macrophages production of free radicals was not significantly affected by glycoconjugates stimulation. The phagocytic activity of RAW 264.7 cells was reduced following GM-1 treatment and was significantly increased after 24 h stimulation with GM-2, contrary to 48 h stimulation. Moreover, the synthetically prepared galactomannoside derivatives have been evaluated as efficient serodiagnostic antigens recognized by specific Ig isotypes, and significant presence of specific IgM antibodies in serum of patients suffering from vulvovaginitis was observed

Electro-rheological properties of transformer oil-based magnetic fluids

The aim of this work was to study rheological behavior of nanofluids affected by electric field and temperature. We used transformer oil-based magnetic fluids, the suspensions of permanently magnetized colloidal particles (Fe_3O_4) coated by a stabilizing surfactant and immersed in transformer oil. The rheological characterization of transformer oil-based magnetic fluid was performed using the rotational rheometer MCR 502 in the shear rate from 10 to 1000 s¯¹.The strength of electric field was changed in the interval 0-6 kV cm¯¹. The flow curves and viscosity functions detected at three different temperatures 25, 50, and 75°C disclose rheological characteristics of samples, first of all the viscosity growth under increasing strength of electric field