In this project, free vibration testing and dynamic mechanical analysis methods were used to study the damping properties of noil hemp fibre-reinforced polypropylene composites with varying fibre contents (0 to 60 wt%) and compatibilizers (maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene octane) under applied frequencies of 1 to 200 Hz. The storage modulus of the composites was increased by the increase in hemp fibre content. However, the maximum damping ratio was obtained from the composite with 30 wt% noil hemp fibre. The addition of coupling agents reduced the damping capacity of all composites. However, 30 wt% noil hemp fibre-reinforced polypropylene coupled with 2.5 wt% anhydride-grafted poly ethylene octane revealed the highest damping ratio among coupled composites. Damping properties of the composites were relatively constant over the frequency range, except at frequencies which the material–instrument system began to resonate and peaks were observed in the curves.

No abstract

No abstract

No abstract

Animal behaviourFeeding Image processing Motion Occupied area A B S T R A C TThe behaviour of broiler chickens has been extensively studied as a function of stocking density and environmental conditions, but limited information was reported in the scientific literature about the effect of feeder type on birds' feeding process. The main objective of this study was to assess the effects of three different feeder types in relation to the birds' behaviour in its surroundings. The analysed feeders were: tube-type with partition grid (F1); tube-type without partition grid (F2); and automatic type with partition grid (F3).The considered variables were: occupied area (OA); activity index (AI) (flock movement); total birds presented in the area (TB); and birds effectively eating (EE). OA and AI were calculated by computational image analysis while TB and EE were manually measured. The results indicated that the feeder type could have influenced the birds' behaviour regarding to OA (R 2 = 0.56), TB (R 2 = 0.48), and EE (R 2 = 0.40), but AI (R 2 = 0.01) was not found to be directly influenced by the feeder type. A higher percentage of birds effectively eating were found in F2 (86.4%), which was the one with the largest free area to access the feed. Similar average number of total birds was found in F1, but with a lower percentage of individuals effectively eating (63.3%), which means that birds were nearby this feeder performing other behaviours. Since the assessed feeders were in the same house under the same conditions, it can be suggested that not only the free area to access the feed but potentially the design of feeders could have influenced the birds' feeding preference. The real beneficial effect of the adoption of partition grid on feed trays is still uncertain, and it is also unclear whether the financial value of reduced wastage would compensate the possible reduction in feed intake.