Parametric Modelling of the Crystalline Microstructure of the MCM41-Type Mesoporous Silica Modified with Derivatives of Alkyls.

A siliceous material in which a framework order was established with a surfactant with sixteen carbon atoms in alkyl chains, MCM-41-C16, was synthesised, surface-modified, and tested regarding the selected physical properties. The pristine material was extracted in an acidic aqueous alcohol and then lined with different surface groups. The properties of four adsorbents were investigated using XRD, X-ray photoelectron spectroscopy, and N2 physisorption techniques.

Studies on the Efficiency of Iron Release from Fe(III)-EDTA and Fe(III)-Cit and the Suitability of These Compounds for Tetracycline Degradation.

Iron ions can be used to degrade tetracycline dispersed in nature. Studies of absorption and fluorescence spectra and quantum chemistry calculations showed that iron is more readily released from Fe(III)-citrate than from Fe(III)-EDTA, so Fe(III)-citrate (Fe(III)-Cit) is more suitable for tetracycline (TC) degradation. At 30 °C, a severe degradation of TC by Fe(III)-Cit occurred as early as after 3 days of incubation in the light, and after 5 days in the dark.

Physiological and Biochemical Parameters of Common Duckweed after the Exposure to Tetracycline and the Recovery from This Stress.

In this study, the ability of L. to recover to normal growth, after being degraded in a tetracycline-containing medium, was extensively investigated. The plants were exposed to tetracycline (TC) at concentrations of 1, 2.

Effect of Dimer Structure and Inhomogeneous Broadening of Energy Levels on the Action of Flavomononucleotide in Rigid Polyvinyl Alcohol Films.

The results of time-resolved fluorescence measurements of flavin mononucleotide (FMN) in rigid polyvinyl alcohol films (PVA) demonstrate that fluorescence intensity decays are strongly accelerated in the presence of fluorescent dimers and nonradiative energy transfer processes. The fluorescence decay originating both from H and J dimer states of FMN was experimentally observed for the first time. The mean fluorescence lifetimes for FMN dimers were obtained: τfl = 2.

Chromatographic study of electron acceptor-donor properties of of 4-(trans-4'-n-alkylcyclohexyl) benzoates.

A new approach of characterizing the specific properties of 4-(trans-4'-n-alkylcyclohexyl) benzoates, based on the interaction of the acidic and basic testing substances, for their form Crystalline, Smectic B and Nematic have been proposed. The testing substances selected for our study have been considered in the light of the results obtained in the previous research and the data available in the literature for other liquid crystals with different structures. The DN values denoting the electron donor number in the Gutmann scale and the AN* values indicating the acceptor number in the Riddle-Fowkes scale have been chosen in the estimation of the electron acceptor parameter K and electron donor parameter K values.