This paper deals with the theoretical and experimental mechanical characteristics of composite plates obtained from recyclable polymer and protein matrix and fibrous reinforcement. The definition of the theoretical model of the monolayer composite material with its structural elements and the physical-mechanical evaluation of its characteristics leads to the optimal and efficient design and use of all products made of such materials. By the theoretical and experimental determination of the mechanical characteristics that define the properties of the composite material, it can be decided on its use in specific industrial technical applications.

This paper analyzes the improvement of ambient air quality indicators by monitoring the NOx concentration in one of the most polluted areas of Bucharest, using the statistical method "SIX SIGMA" (6σ). By applying the methodology of this statistical approach, the aim is to reduce non-conformities within the specified limits (according to the standards and legislative norms in force) and respectively, to ensure maximum efficiency (99,99%), equivalent to a yield of 3.4 defects per million opportunities (DPMO). As high concentrations of air pollutants have a major impact on human health, the most harmful effect has been found to be caused by nitrogen dioxide (NO2), mainly from ground-level ozone. Using the "6σ" method, the optimal solutions for eliminating non-conformities and implicitly for reducing the NO2 concentration and ensuring the improvement of the ambient air quality can be identified.

The paper addresses the comparative analytical determination of thermal insulation behavior for various experimental models made of stratified and hybrid biocomposites of ligno-cellulose nature. The analytical determination of the thermal resistance and the overall thermal insulation coefficient for each experimental model is performed using the calculation methodology for energy efficiency. The results obtained after the analysis of the thermal insulation behavior for the biocomposite panels highlighted the fact that they have thermal insulation properties with high values for thermal resistance and global thermal insulation coefficients.

This paper highlights through the issues addressed, the application aspects regarding the approach of the concept of recovery of sewage sludge from an urban wastewater treatment plant (SEAU), which is in a stage of technological expansion and modernization. Thus, it is considered the need to process the potential of biological mass generated by anaerobic stabilization in the SEAU, with a population of about 10,000 equivalent inhabitants, which requires on one hand, the technological design of activated sludge basins and on the other hand, the design of a sewage sludge fermentation tank, in order to produce biogas, necessary for its recovery for energy purposes.