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The genus Helcogrammoides comprises three species of small, cryptic shorefishes, H. antarcticus, H. chilensis, and H. cunninghami. All three species inhabit shallow water along exposed rocky coasts. Specimens reported herein extend the known distributions of H. chilensis and H. cunninghami to the vicinity of Lima, Peru, approximately 1600 km north of their previously reported northernmost records in Chile. Helcogrammoides chilensis and H. cunninghami occur sympatrically over most of their ranges in Peru and Chile and are frequently taken together in the same field collections. Lectotypes are designated for H. chilensis and H. cunninghami. Diagnoses and an identification key are provided for the species. Se amplía 1600 km al norte la distribución de H. chilensis y H. cunninghami a Lima, Peru, donde con frecuencia se hallan en simpatría Se designa leptotipos para H. chilensis y H. cunninghami. Se incluye diagnósticos de especies y una clave para el género.

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-05T18:30:44Z No. of bitstreams: 1 Dissertacao_VictorGuilhermeAmaralSpringer.pdf: 3130650 bytes, checksum: 6e389c129eaefc67ef29944d570fae10 (MD5) Made available in DSpace on 2021-01-05T18:30:44Z (GMT). No. of bitstreams: 1 Dissertacao_VictorGuilhermeAmaralSpringer.pdf: 3130650 bytes, checksum: 6e389c129eaefc67ef29944d570fae10 (MD5) Previous issue date: 2015-10-05 Sliding systems with interface formed by low alloy steels and various polymers are widely used in the automotive industry in torque transmission systems subjected to axial loading. Usually these systems are coupled to steering systems and interact almost directly with the final user of the vehicle. To know the most severe wear conditions which these systems are submitted and attempt to overcome them, the tribological analysis was proposed on tribometer of the pin-on-disk type, on an interface formed by SAE 1020 steel with polyamide 11 in distilled water, 5 wt% aqueous solution of sodium chloride and 184,21 g/l natural sand aqueous solution in accordance with the automotive technical standards VW PV1210: 2010-02 and VW PV2982: 2013-07. The tests were performed at frequencies of 3.0 Hz and 1.5 Hz with a fixed amount of rotation of 10,000 cycles. The corrosion potential on open circuit was monitored throughout the test and the wear rate was calculated. It was highlighted higher friction coefficients, higher wear rates and higher corrosion potential amplitudes in samples assayed in sand solution; with milder values for the samples tested in distilled water and intermediate values for samples tested with sodium chloride solution. Sistemas deslizantes com interface formada com aços baixa liga e polímeros variados são vastamente utilizados na indústria automotiva em sistemas de transmissão de torque submetidas à carregamento axial. Geralmente esses sistemas são acoplados aos sistemas de direção e interagem quase diretamente com o usuário final do veículo. Para conhecer as condições de desgaste mais severas as quais esses sistemas são submetidos e tentar minimiza-las, foi proposta a análise tribológica, em tribômetro do tipo pino-no-disco, da interface aço SAE 1020 com poliamida 11 em água destilada, solução aquosa com 5% em massa de cloreto de sódio e solução aquosa com 184,21 g/l. de areia natural, de acordo com as normas técnicas automotivas VW PV1210:2010-02 e VW PV2982:2013-07. Os ensaios foram realizados em frequências de 3,0 Hz e 1,5 Hz com quantidade fixada em 10.000 ciclos de rotação. O potencial de corrosão em circuito aberto foi monitorado ao longo dos ensaios e a taxa de desgaste foi calculada. Foram evidenciados maiores coeficientes de atrito, maiores taxas de desgaste e maiores amplitudes de potencial de corrosão nas amostras ensaiadas em solução de areia; com valores mais brandos para as amostras ensaiadas em água destilada e valores intermediários para as amostras ensaiadas em solução de cloreto de sódio.