RESUMO
Earthworks in the vicinity of roads, open mines, subsidence tanks and other man-made objects can lead to the creation of slopes that undergo erosion. One of the methods that can prevent their degradation and reclaim them is the use of geotextiles. An environmentally friendly option is using geotextiles that are produced from reclaimed fibres. The purpose of this study was to examine the role of the mechanical and chemical properties of geotextiles, namely, ropes and fibres (containing wool and polypropylene), not only on the rate of the greening of slopes but also on the species composition of vegetation. We studied the floristic composition, species diversity, species growth and soil properties of four sites of reclaimed slopes on which 46 study plots (5 m × 5 m) were laid out. We found that some species were more confined to a higher content of wool and that other species were more confined to the content of polypropylene. Both materials caused a decrease in the Shannon-Wiener diversity but an increase in evenness under the impact of ropes when compared to the control. They both also contributed to a higher mean height of the plants when compared to the control. The rate of the plant colonisation process was markedly improved by the reclaimed geotextiles. A longer and more detailed study is required to examine the effect of geotextile ropes on habitat creation.
RESUMO
Wool of mountain sheep, treated nowadays as a waste or troublesome byproduct of sheep husbandry, was used for the production of sound-absorbing materials. Felts of two different thicknesses were produced from loose fibres. Additionally, two types of yarn, ring spun and core rug, were obtained. The yarns were used for the production of tufted fabric with cut and loop piles. During the examinations, basic parameters of the obtained materials were determined. Then, according to standard procedure with the use of impedance tube, the sound absorption coefficient was measured, and the noise reduction coefficient (NRC) was calculated. It was revealed that felt produced from coarse wool exhibits high porosity, and its sound absorbing capacity is strongly related to the felt thickness. For thicker felt the NRC achieved 0.4, which is comparable with the NRC of commercial ceiling tiles. It was shown that the crucial parameter influencing the sound absorption of the tufted fabrics was the pile height. For both types of yarns, when the height of the pile was increased from 12 to 16 mm, the NRC increased from 0.4 to 0.42. The manufactured materials made from local wool possess good absorption capacity, similar to commercial products usually made from more expensive wool types. The materials look nice and can be used for noise reduction as inner acoustic screens, panels, or carpets.
