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 eccentricities379791804COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESNão 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 étude était d’observer les relations entre la perception de l’effort (RPE) lors d’un exercice global de karaté (RPE-S) et des mesures objectives reflétant l’intensité de l’exercice durant une séance d’entraînement. Méthodes : Huit karatékas bien entraînés ont effectué une séance d’entraînement comprenant des séquences techniques et d’opposition. La fréquence cardiaque (HR) était enregistrée en continue, alors que la concentration sanguine en lactate ([lac]b) et la RPE (échelle de 6–20 de Borg) étaient mesurées toutes les dix minutes durant la séance. Les athlètes donnèrent aussi leur RPE (échelle de 0–10 de Borg) 30 minutes après la séance. Résultats : Des corrélations significatives (p < 0,05) ont été observées entre les valeurs de RPE-S et de HR (exprimées en % de HRmax, rp = 0,91), %HR réserve (rp = 0,87), [lac]b (rp = 0,96), et RPE (rp = 0,78) pendant la séance, mais pas entre RPE-S et la durée de l’exercice (rp = −0,28 ; p > 0,05). RPE-S était aussi significativement corrélée (p < 0,05) au pourcentage de temps passé sous le premier seuil ventilatoire (rp = −0,96), entre les seuils (rp = 0,93) et au dessus du point de compensation respiratoire (rp = 0,96). Conclusion : Ces résultats suggèrent que RPE-S peut être un outil valide pour mesurer les variations inter individuelles de l’intensité d’un exercice global de karaté à l’entraînement

Correlates of session-rate of perceived exertion (RPE) in a karate training session

Objectif : Le but de cette étude était d’observer les relations entre la perception de l’effort (RPE) lors d’un exercice global de karaté (RPE-S) et des mesures objectives reflétant l’intensité de l’exercice durant une séance d’entraînement. Méthodes : Huit karatékas bien entraînés ont effectué une séance d’entraînement comprenant des séquences techniques et d’opposition. La fréquence cardiaque (HR) était enregistrée en continue, alors que la concentration sanguine en lactate ([lac]b) et la RPE (échelle de 6–20 de Borg) étaient mesurées toutes les dix minutes durant la séance. Les athlètes donnèrent aussi leur RPE (échelle de 0–10 de Borg) 30 minutes après la séance. Résultats : Des corrélations significatives (p < 0,05) ont été observées entre les valeurs de RPE-S et de HR (exprimées en % de HRmax, rp = 0,91), %HR réserve (rp = 0,87), [lac]b (rp = 0,96), et RPE (rp = 0,78) pendant la séance, mais pas entre RPE-S et la durée de l’exercice (rp = −0,28 ; p > 0,05). RPE-S était aussi significativement corrélée (p < 0,05) au pourcentage de temps passé sous le premier seuil ventilatoire (rp = −0,96), entre les seuils (rp = 0,93) et au dessus du point de compensation respiratoire (rp = 0,96). Conclusion : Ces résultats suggèrent que RPE-S peut être un outil valide pour mesurer les variations inter individuelles de l’intensité d’un exercice global de karaté à l’entraînement

Caracterização química do "pitch" em indústria 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 química do "pitch" em indústria 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 química do “pitch” em indústria 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