Bacterial cellulose (BC) is a unique biopolymer synthesised by many bacteria as a critical element of their biofilm matrix. The most known and efficient producers of BC are bacteria from the genus of Komagataeibacter. Bacterial cellulose, with its unique properties, high crystallinity, mechanical strength, and unprecedented ability to hold water, is an object of interest in many industries. Despite the enormous efforts that have been made to develop an effective process, the economic aspect of BC production is still a limiting factor for broadening applications, and new “breaking point” solutions are highly anticipated. In this study, the possibility of using sucrose, lactose, and starch as alternative carbon sources converted to simple sugars directly in the culture medium by microbial glycohydrolases, β-D-fructofuranosidase, β-galactosidase, and glucoamylase in the process of BC synthesis was analysed. The results showed the high potential of the enzyme-assisted fermentation process that, for most used raw carbons sources, was highly efficient, with a yield higher (i.e., lactose 40% more) or comparable to the cultures maintained on standard Hestrin-Schramm media with glucose as a sole carbon source. The X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope analyses did not reveal any negative influence of enzyme-assisted cultivation on the BC material properties, such as crystallinity, swelling ratio, and moisture content. Applying specific enzymes for converting inaccessible, raw-form carbon sources to the culture medium of Komagateibacter xylinus opens a simple way to use various oligo- and polysaccharides acquired from many kinds of biomass sources in the BC production process.

In the face of increasing global carbon dioxide emissions and the urgent need to mitigate climate change, the development of efficient and sustainable strategies for CO₂ conversion has gained significant attention. One of the methods of eliminating the harmful effects of CO₂ is its photoreduction. In this paper, ZnO was used as an effective photocatalyst for the photoreduction of CO₂ in a gas-phase system. The influence of particle size on the process efficiency was investigated. The ZnO materials applied in the studies were characterized using XRD, SEM, and low-temperature nitrogen adsorption (BET) methods. The pore volume distribution was calculated based on the DFT method. The investigation confirmed that it had a significant impact on the formation of the product of photocatalysis carbon dioxide. The main identified product was carbon monoxide. Hydrogen and methane were detected as well. Based on the results, it was found that the process efficiency was enhanced with decreasing ZnO particle size, and the most effective catalyst for the photoreduction of CO₂ was the ZnO sample with the smallest particle size (18 nm).

The study analyzes the anisotropy effect for ceramic masonry based on experimental tests of samples made of 25 × 12 × 6.5 cm³ solid brick elements with compressive strength f_b = 44.1 MPa and cement mortar with compressive strength f_m = 10.9 MPa. The samples were loaded in a single plane with a joint angle that varied from the horizontal plane. The load was applied in a vertical direction. The samples were loaded at angles of 90°, 67.5°, 45°, 22.5°, and 0° toward the bed joints. The most unfavourable cases were determined. It was observed that the anisotropy of the masonry significantly influences the load-bearing capacity of the walls depending on the angle of the compressive stresses trajectory. Approximation curves and equations for compressive strength, Young’s modulus, and Poisson’s coefficient were proposed. It was observed that Young’s modulus and Poisson’s ratio will also change depending on the trajectory of compressive stresses as a function of the joint angle. Experimental tests allowed to determine the failure mechanism in prepared specimens. The study allowed to estimate the masonry strength with the load acting at different angles toward the bed joints.

In a nanoFe/NH ₃ /H ₂ system a hysteresis phenomenon occurs and two phases coexist, according to the extended phase rule of Gibbs due to a degree of freedom associated with the nanocrystallite size.