Similarity analysis of the momentum field of a subsonic, plane air jet with varying jet-exit and local Reynolds numbers

A similarity analysis is presented of the momentum field of a subsonic, plane air jet over the range of the jet-exit Reynolds number Reh (≡ Ubh/υ where Ub is the area-averaged exit velocity, h the slot height, and υ the kinematic viscosity) = 1500 − 16 500. In accordance with similarity principles, the mass flow rates, shear-layer momentum thicknesses, and integral length scales corresponding to the size of large-scale coherent eddy structures are found to increase linearly with the downstream distance from the nozzle exit (x) for all Reh. The autocorrelation measurements performed in the near jet confirmed reduced scale of the larger coherent eddies for increased Reh. The mean local Reynolds number, measured on the centerline and turbulent local Reynolds number measured in the shear-layer increases non-linearly following x^(1/2), and so does the Taylor microscale local Reynolds number that scales as x^(1/4). Consequently, the comparatively larger local Reynolds number for jets produced at higher Reh causes self-preservation of the fluctuating velocity closer to the nozzle exit plane. The near-field region characterized by over-shoots in turbulent kinetic energy spectra confirms the presence of large-scale eddy structures in the energy production zone. However, the faster rate of increase of the local Reynolds number with increasing x for jets measured at larger Reh is found to be associated with a wider inertial sub-range of the compensated energy spectra, where the −5/3 power law is noted. The downstream region corresponding to the production zone persists for longer x/h for jets measured at lower Reh. As Reh is increased, the larger width of the sub-range confirms the narrower dissipative range within the energy spectra. The variations of the dissipation rate (ε) of turbulent kinetic energy and the Kolmogorov (η) and Taylor (λ) microscales all obey similarity relationships, εh/Ub^(3)∼ Re^(3), η/h ∼ Re^(−3/4) and λ/h ∼ Re (-1/2). Finally, the underlying physical mechanisms related to discernible self-similar states and flow structures due to disparities in Reh and local Reynolds number is discussed

Conflicts between capuchin monkeys and visitors inside the Brasília National Park: possible solutions

Os conflitos entre os visitantes e os macacos-prego na área das piscinas do Parque Nacional de Brasília (PNB) têm origem na presença de alimentos levados pelos próprios visitantes, objetos de atração dos macacos-prego. Com base na literatura e resultados de pesquisas desenvolvidas no próprio local, o trabalho apresenta as recomendações à administração do PNB para reduzir os níveis de o conflito.The conflicts between the capuchin monkeys and the visitors inside the swimming pool areas of the Brasilia National Park (Brazil) lays on the presence of the food handled by the visitors, which attracts the monkeys. Based on the literature and on the results of researches developed in this National Park, this works presents some proposals to the National Park administration to get lower incidence of conflicts

A god becomes a pest? Human-rhesus macaque interactions in Himachal Pradesh, northern India

Human-rhesus macaque conflict due to crop raiding is a major problem affecting northern India, particularly the states of Himachal Pradesh and Uttarakhand. Management techniques are challenging both due to the commensal nature of the macaque as well as the culturally significant status of the species in India. Studies on wildlife crop raiding indicate that people’s reactions to crop raiding are strongly influenced by their attitudes towards the species involved and that insights into these perceptions are critical to work towards conflict-resolution measures. Hence, we investigated the attitudes and perceptions of farmers in Bilaspur district, Himachal Pradesh, towards the rhesus macaque (Macaca mulatta) and the impact of macaque crop raiding on their lives. We interviewed 54 farmer-families from five villages in Bilaspur and collected data on the extent of crop damage caused by wildlife species, farmers’ attitudes towards the rhesus macaque and conflict-mitigation strategies as suggested by the farmers. The results of our study indicate that farmers hold ambivalent attitudes towards the rhesus macaque and mixed opinions regarding its management