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In construction, hollow-core concrete blocks (HCBs) offer a number of advantages over solid blocks, such as lighter weight and improved thermal and acoustic insulation. However, the relative high value of the overall heat transfer coefficient (U-value), makes them less attractive for use in new buildings in Europe, given that these must approach the net-zero energy performance level by 2020. In this respect, a project has been developed in Malta, which aims at producing a new HCB having the same physical dimensions and load bearing characteristics as a standard locally-produced HCB, but with improved thermal properties. The project (ThermHCB) is being co-financed by the Malta Council for Science and Technology (MCST) under the 2012 R&I National Programme. ThermHCB project is divided into a number of Work Packages covering the whole process from developing the HCB, manufacturing, testing and optimizing the final commercial product. This paper focuses on one aspect of this project, namely on the testing methodologies that are being proposed and implemented, for the load bearing as well as thermal characterization of the HCBs. In the latter, two procedures are being adopted to compare the thermal properties of standard and prototype HCBs, using infra-red techniques and heat flow methodology. Comparisons shall be made to verify whether the infra-red method, which offers faster measurement techniques, provides U-value results that are sufficiently accurate. [ABSTRACT FROM AUTHOR]

This study aims to determine the level of floating marine litter in coastal and inshore areas around Malta and Gozo (Central Mediterranean) and to investigate factors which influence litter distribution. Observations of macro-litter and mega-litter were conducted through seasonal boat surveys around Malta and Gozo during 2018–2019. Visual observations were conducted along line transects whilst maintaining a 6 m observation width. For coastal areas, of up to −1 km away from the shoreline, the total density of litter ranged between 27 and 2428 items/km2, with a mean of 292 ± 85 items/km2. Within inshore areas the density varied between 180 and 46,289 items/km2, with a mean of 3242 ± 1880 items/km2. The highest density was present in winter, this being 2.5 higher than the lowest density season. 91% of the litter was plastic. The manner in which anthropogenic factors and natural events influenced litter accumulations and distributions, are described. • The highest average density of marine litter was reported in the season of winter. • Plastic accounted for 91% of the marine litter items observed. • The most common floating marine litter item around Malta is plastic fragments. • Natural sea foam and oil may act as a retention mechanism for floating litter. [ABSTRACT FROM AUTHOR]

Abstract: This study addresses the influence of three different land use systems (continuous maize, pasture/maize rotation, permanent pasture) on the relationships between earthworm populations and the number of earthworm burrows quantified in a soil profile. Quantified burrows were limited to those observable by the naked eye (i.e. >2mm in diameter) and enumerated earthworms were limited to those which could have created the observable burrows (i.e. >0.3g). The results were combined with data from the literature coming from different geographical regions. This study showed that earthworm abundance decreased with the increasing land management intensity (maize crop vs. pasture), while the number of burrows could be higher or similar under maize compared to pasture. Under maize, despite lower earthworm abundance and the annual destruction of the burrows by tillage, the number of burrows was almost as high as under pasture. This absence of a relationship between burrow numbers and earthworm abundance was observed in the soil profile and for each layer of the profile for each land use system. Furthermore, the burrow number/m−2 per earthworm strongly varied depending on land use and was far higher under maize when compared to pasture (74 vs. 7). Therefore, a power-law type relationship was clearly established between burrow number/m−2 per earthworm and earthworm abundance. This power type relationship was also observed when including data from the literature although it followed a different mathematical model. These results were explained by (i) increased earthworm burrowing activity (i.e. an increase in the number of burrows produced by each earthworm) under maize, and (ii) the dynamics of burrow number under pasture (i.e. decreased burrowing activity and burrow destruction process); both results of food accessibility combined with inter-individual competition. The results of the study suggest that farmers should not use the number of pores as an indicator of earthworm abundance, but as an indicator of earthworm activity, which could be integrated in an indicator of soil quality. [Copyright &y& Elsevier]