"Soft and rigid" dithiols and Au nanoparticles grafting on plasma-treated polyethyleneterephthalate

Surface of polyethyleneterephthalate (PET) was modified by plasma discharge and subsequently grafted with dithiols (1, 2-ethanedithiol (ED) or 4, 4'-biphenyldithiol) to create the thiol (-SH) groups on polymer surface. This "short" dithiols are expected to be fixed via one of -SH groups to radicals created by the plasma treatment on the PET surface. "Free" -SH groups are allowed to interact with Au nanoparticles. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and electrokinetic analysis (EA, zeta potential) were used for the characterization of surface chemistry of the modified PET. Surface morphology and roughness of the modified PET were studied by atomic force microscopy (AFM). The results from XPS, FTIR, EA and AFM show that the Au nanoparticles are grafted on the modified surface only in the case of biphenyldithiol pretreatment. The possible explanation is that the "flexible" molecule of ethanedithiol is bounded to the activated PET surface with both -SH groups. On the contrary, the "rigid" molecule of biphenyldithiol is bounded via only one -SH group to the modified PET surface and the second one remains "free" for the consecutive chemical reaction with Au nanoparticle. The gold nanoparticles are distributed relatively homogenously over the polymer surface

Komplexní geochemický výzkum interakcí a migrací organických a anorganických látek v horninovém prostředí:Průběh hydrodynamických zkoušek na vrtech PTP3 a PTP4 na lokalitě Potůčky - Podlesí

Popis terénních prací na obou vrtech - dokončení vodních tlakových zkoušek v průběhu vrtání na vrtu PTP-3, instalace multipakrového systému a následný monitoring tlaků v jednotlivých etážích na vrtu PTP-3, vodní tlakové zkoušky v průběhu vrtání na později zhavarovaném vrtu PTP-4, hydrodynamické zkoušky v průběhu vrtání, dlouhodobé hydrodynamické zkoušky, stopovací zkoušky

Assessment of the historical, architectural and structural value of masonry arch road bridges

The aim of the methodology is to become a tool for proper decision-making and care of historic masonry arch bridges serving our transport network and to contribute to their preservation. It should help to identify and correctly assess their historical significance and their cultural, structural and heritage value. To correctly guide the process of their professional evaluation and proposals for their maintenance and restoration. Demonstrate the possibilities of their correct assessment in terms of their structural-technical condition and structural-mechanical action, enabling their preservation in reliable operation in traffic. By means of these correct procedures, it would like to establish general confidence in their design principles and craftsmanship and to translate this into the design of reconstruction and restoration interventions or appropriate adaptations with modern sensitive additions. It is intended to enable the legitimate existence and functioning of these irreplaceable buildings for our present and future