Analyse of the Evolution of the Hygrothermal Properties of the Hemp-Based Mortar within the Framework of the Total Weathering Protocol

The use of bio-based composites for building insulation is interesting from the point of view of hygrothermal performances, economic and environmental benefits. Among different organic fibers for these materials, hemp is interesting because of its huge availability in France. Nevertheless, the broad application of the hemp-based insulation mortars is hampered due to the lack of a database on their durability. This paper consists of a better understanding of the evolution of the hemp-based composite and its hygrothermal properties. The main objectives are, first, to study the evolution of the hemp insulation mortar microstructure and properties under the accelerated aging cycles, and second, to characterize and analyze the interconnection between observed changes. Experimentally, the protocol of accelerated aging inspired by standardized one was proposed, the microstructural characteristics and the hygrothermal properties, as the total porosity, the thermal conductivity, and the moisture buffer value (MBV) before and after the aging cycles was identified. The MBV characterization was performed for both hemp mortar and hemp shives. The obtained results reveal the increase of the hemp mortar porosity and the decrease of the hemp mortar's thermal conductivity. Furthermore, the MBV value of hemp mortar changes slightly, unlike that of the bulk hemp, which is explained by the mineral matrix's influence. These results consist of data for a better forecast on the degradation of the hemp mortar.

Research in Sustainable Energy Systems at the Department of Management and Engineering during the First 15 Years of 2000

At the Department of Management and Engineering (DTG) of the University of Padova (Italy), the research team led by Prof. Renato Lazzarin, formed by the authors, worked during the first fifteen years of the millennium on different topics focused on sustainable technologies for energy production and utilization in buildings. Both experimental and theoretical/modeling studies were carried out, all sharing the evaluation of energy performance and sustainability: From the life cycle assessment and life cycle cost of building insulation materials in Italy, to the measurement of energy performance of a green roof, to the experimental measurement of different photovoltaic/thermal modules, to the development of a simulation software for direct and indirect evaporative cooling techniques, to the evaluation of different energy savings techniques for refrigeration and air conditioning in supermarkets, to an extensive analysis of the urban heat island effect in the city of Padova. The paper summarizes the main theoretical and experimental approaches, providing the methods adopted in each line of research. The main results of the studies conducted during the fifteen-year period are described and commented on, some of which were a well-established reference for the following literature.

Biodegradation of Different Types of Plastics by Tenebrio molitor Insect

Looking for new, sustainable ways to utilize plastics is still a very pertinent topic considering the amount of plastics produced in the world. One of the newest and intriguing possibility is the use of insects in biodegradation of plastics, which can be named entomoremediation. The aim of this work was to demonstrate the ability of the insect Tenebrio molitor to biodegrade different, real plastic waste. The types of plastic waste used were: remains of thermal building insulation polystyrene foam (PS), two types of polyurethane (kitchen sponge as PU1 and commercial thermal insulation foam as PU2), and polyethylene foam (PE), which has been used as packaging material. After 58 days, the efficiency of mass reduction for all of the investigated plastics was 46.5%, 41.0%, 53.2%, and 69.7% for PS, PU1, PU2, and PE, respectively (with a dose of 0.0052 g of each plastic per 1 mealworm larvae). Both larvae and imago were active plastic eaters. However, in order to shorten the duration of the experiment and increase the specific consumption rate, the two forms of the insect should not be combined together in one container.