Navegando por Assunto "Transporte"

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Acesso aberto (Open Access)
Análise de esforços resultantes de impactos entre barcaças de comboios fluviais para modelagem de um sistema de amortecimento de choques utilizando teoria de análise multicorpos
(Universidade Federal do Pará, 2018-03-09) CRUZ, Fernando Costa da; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137; https://orcid.org/0000-0003-4224-767X
In this dissertation an analysis is performed on the operational behavior of river barges convoys in navigation regions with presence of waves, winds and currents. A study is carried out to determine the applicant forces present in the mooring elements and in the contact points between barges in flotillas when they are sailing in dangerous navigation conditions. A theoretical study is carried out, identifying the main response movements of floating bodies. In this case, a model is developed using the ANSYS AQWA 17 software to identify the stress levels from impacts between barges that make up the formations, as well as the degree and behavior of the tensile stresses present in the mooring ropes over time. In addition, a practical study is used as a comparative model of data, being very important for the validation of the results achieved by the computational model. In this way, the proposed scenario within the computational program describes environmental characteristics to describe the navigation problem in a clear way. At the end of this work the levels of effort captured within the computational model are presented, being divided into two models of fluvial flotillas, a convoy with barges for soybean transportation, and another with barges for the transport of iron ore, being discriminated the locations of the higher levels of effort. It is important to note the pioneering role of this work in relation to the problems perceived within the area of operational safety of fluvial flotillas, using Finite Element tools as the main evaluation tool.
Acesso aberto (Open Access)
Transporte de oócitos bovinos em meio de maturação por diferentes períodos de tempo sem controle da atmosfera gasosa
(2011-02) SILVA, Lílian Kátia Ximenes; REIS, Adriana Novaes dos; SILVA, Aluizio Otavio Almeida da; SOUSA, José Silva de; SOUSA, Alysson Jorge de Oliveira; VALE, William Gomes
The viability of the transport of the bovine oocytes was evaluated in chemically defined medium and the need for the addition or not of hormones in this medium was analyzed. The oocytes in the control group (0h) were matured for 24h in CO2 incubator, and in experimental groups they were transported in portable incubator. In experiment I, the cleavage rates were similar (P>0.05) to the groups 0h (59.7%), 3h (53.5%), and 9h (48.8%), but they decreased in groups 6h (46.1%) and 12h (43.8%), however, these rates were similar among the groups 3h, 6h, 9h, and 12h. The production of blastocysts was not different (P>0.05) for groups 0h (38.0%), 3h (32.3%), 6h (27.3%), and 9h (24.8%), but there was a reduction in the 12h group (18.9%). These rates were similar among the groups 6h, 9h and 12h. In experiment II, no significant difference (P>0.05) was observed among the rates of cleavage for the groups 0h (71.4%), 3h with (70.3%) and without hormones (64.8%), and 6h with (56.0%) and without hormones (54.1%). The production of blastocysts was similar (P>0.05) for groups 0h (46.1%) and 3h with (45.8%) and without hormones (41.1%), but decreased in groups 6h with (35.5%) and without hormones (33.5%). These rates were similar among the groups 3h without, 6h with and without hormones. These results indicate the possibility of the transport of bovine oocytes up to 9h, and the addition of hormones in this medium does not influence the rates of cleavage and blastocysts.