22 research outputs found
Heat transfer in a horizontal cylinder with eccentric surfaces
Heat transfer in horizontal cylinders exposed to free convection and radiation is of importance in many industries. Usually this problem is treated by adopting a concentric geometry, disregarding that the external surface temperature is not uniform. If an eccentric geometry is used, the external surface temperature should have a larger variation, changing the flow around the cylinder and the heat transfer coefficient, either improving or reducing the heat transfer. A numerical analysis is presented of the heat transfer in a horizontal cylinder with an internal isothermal surface eccentric to the external surface that is exposed to air free convection and radiation. The conduction problem was solved analytically and integrated numerically, while the free convection was solved by the PHOENICS software. The parameters analyzed were the ratio of radius, the ratio between the material and air thermal conductivities, the Rayleigh number, the emissivity of the outer surface, and the eccentricity between the external and inner surfaces. The parameters of a proposed equation to estimate the total heat of an eccentric arrangement in terms of the total heat of the corresponding concentric arrangement and the ratio between the convective and conductive thermal resistances were determined for given ratios of radius and eccentricities379791804COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESNĂŁo te
Cardiogenic shock due to coronary artery disease associated with interrupted aortic arch
Acute pulmonary edema is a serious event. Its occurrence in association with interrupted aortic arch and coronary heart disease is rare. Recently, an old patient developed cardiogenic shock and acute pulmonary edema due to acute coronary insufficiency, associated with interrupted aortic arch. The coronary angiography revealed occlusion of the right coronary artery and 95% obstruction in the left main coronary artery, associated with interruption of the descending aorta. Coronary artery bypass graft was performed, without extracorporeal circulation, to the anterior descending coronary artery. We discuss the initial management, given the seriousness of the case
Correlates of session-rate of perceived exertion (RPE) in a karate training session
Objectif : Le but de cette Ă©tude Ă©tait dâobserver les relations entre la perception de lâeffort (RPE) lors dâun exercice global de karatĂ© (RPE-S) et des mesures objectives reflĂ©tant lâintensitĂ© de lâexercice durant une sĂ©ance dâentraĂźnement. MĂ©thodes : Huit karatĂ©kas bien entraĂźnĂ©s ont effectuĂ© une sĂ©ance dâentraĂźnement comprenant des sĂ©quences techniques et dâopposition. La frĂ©quence cardiaque (HR) Ă©tait enregistrĂ©e en continue, alors que la concentration sanguine en lactate ([lac]b) et la RPE (Ă©chelle de 6â20 de Borg) Ă©taient mesurĂ©es toutes les dix minutes durant la sĂ©ance. Les athlĂštes donnĂšrent aussi leur RPE (Ă©chelle de 0â10 de Borg) 30 minutes aprĂšs la sĂ©ance. RĂ©sultats : Des corrĂ©lations significatives (p < 0,05) ont Ă©tĂ© observĂ©es entre les valeurs de RPE-S et de HR (exprimĂ©es en % de HRmax, rp = 0,91), %HR rĂ©serve (rp = 0,87), [lac]b (rp = 0,96), et RPE (rp = 0,78) pendant la sĂ©ance, mais pas entre RPE-S et la durĂ©e de lâexercice (rp = â0,28 ; p > 0,05). RPE-S Ă©tait aussi significativement corrĂ©lĂ©e (p < 0,05) au pourcentage de temps passĂ© sous le premier seuil ventilatoire (rp = â0,96), entre les seuils (rp = 0,93) et au dessus du point de compensation respiratoire (rp = 0,96). Conclusion : Ces rĂ©sultats suggĂšrent que RPE-S peut ĂȘtre un outil valide pour mesurer les variations inter individuelles de lâintensitĂ© dâun exercice global de karatĂ© Ă lâentraĂźnement
Correlates of session-rate of perceived exertion (RPE) in a karate training session
Objectif : Le but de cette Ă©tude Ă©tait dâobserver les relations entre la perception de lâeffort (RPE) lors dâun exercice global de karatĂ© (RPE-S) et des mesures objectives reflĂ©tant lâintensitĂ© de lâexercice durant une sĂ©ance dâentraĂźnement. MĂ©thodes : Huit karatĂ©kas bien entraĂźnĂ©s ont effectuĂ© une sĂ©ance dâentraĂźnement comprenant des sĂ©quences techniques et dâopposition. La frĂ©quence cardiaque (HR) Ă©tait enregistrĂ©e en continue, alors que la concentration sanguine en lactate ([lac]b) et la RPE (Ă©chelle de 6â20 de Borg) Ă©taient mesurĂ©es toutes les dix minutes durant la sĂ©ance. Les athlĂštes donnĂšrent aussi leur RPE (Ă©chelle de 0â10 de Borg) 30 minutes aprĂšs la sĂ©ance. RĂ©sultats : Des corrĂ©lations significatives (p < 0,05) ont Ă©tĂ© observĂ©es entre les valeurs de RPE-S et de HR (exprimĂ©es en % de HRmax, rp = 0,91), %HR rĂ©serve (rp = 0,87), [lac]b (rp = 0,96), et RPE (rp = 0,78) pendant la sĂ©ance, mais pas entre RPE-S et la durĂ©e de lâexercice (rp = â0,28 ; p > 0,05). RPE-S Ă©tait aussi significativement corrĂ©lĂ©e (p < 0,05) au pourcentage de temps passĂ© sous le premier seuil ventilatoire (rp = â0,96), entre les seuils (rp = 0,93) et au dessus du point de compensation respiratoire (rp = 0,96). Conclusion : Ces rĂ©sultats suggĂšrent que RPE-S peut ĂȘtre un outil valide pour mesurer les variations inter individuelles de lâintensitĂ© dâun exercice global de karatĂ© Ă lâentraĂźnement
Caracterização quĂmica do "pitch" em indĂșstria de celulose e papel de Eucalyptus Chemical characterization of pitch in Eucalyptus pulp and paper industry
<abstract language="eng">The chemical analysis of the acetone, chloroform, toluene and methanol extracts of a pitch sample was carried out by IR and GC-MS, leading to the identification of sixty nine compounds, including fatty acids, alcohols and hydrocarbons. Analysis of the acetone extractive of a eucalyptus wood used in Brazil for pulp production was also carried out, resulting in identification of fifty nine compounds, including mainly fatty acids, phenolic compounds, beta-sitosterol and other steroids. This analysis showed that pitch formation had a contribution from wood extractives and other sources of contamination. The results obtained and the methodology applied can be used by the pulp industry to develop new methods of pitch control
Caracterização quĂmica do "pitch" em indĂșstria de celulose e papel de Eucalyptus
The chemical analysis of the acetone, chloroform, toluene and methanol extracts of a pitch sample was carried out by IR and GC-MS, leading to the identification of sixty nine compounds, including fatty acids, alcohols and hydrocarbons. Analysis of the acetone extractive of a eucalyptus wood used in Brazil for pulp production was also carried out, resulting in identification of fifty nine compounds, including mainly fatty acids, phenolic compounds, beta-sitosterol and other steroids. This analysis showed that pitch formation had a contribution from wood extractives and other sources of contamination. The results obtained and the methodology applied can be used by the pulp industry to develop new methods of pitch control
Caracterização quĂmica do âpitchâ em indĂșstria de celulose e papel de Eucalyptus
The chemical analysis of the acetone, chloroform, toluene and methanol extracts of a pitch sample was carried out by IR and GC-MS, leading to the identification of sixty nine compounds, including fatty acids, alcohols and hydrocarbons. Analysis of the acetone extractive of a eucalyptus wood used in Brazil for pulp production was also carried out, resulting in identification of fifty nine compounds, including mainly fatty acids, phenolic compounds, b-sitosterol and other steroids. This analysis showed that pitch formation had a contribution from wood extractives and other sources of contamination. The results obtained and the methodology applied can be used by the pulp industry to develop new methods of pitch control