Saturated flow boiling heat transfer and critical heat flux in small horizontal flattened tubes

This paper presents experimental results for flow boiling heat transfer coefficient and critical heat flux (CHF) in small flattened tubes. The tested flattened tubes have the same equivalent internal diameter of 2.2 mm, but different aspect height/width ratios (H/W) of 1/4, 1/2, 2 and 4. The experimental data were compared against results for circular tubes using R134a and R245fa as working fluids at a nominal saturation temperature of 31 degrees C. For mass velocities higher than 200 kg/m(2)s, the flattened and circular tubes presented similar heat transfer coefficients. Such a behavior is related to the fact that stratification effects are negligible under conditions of higher mass velocities. Heat transfer correlations from the literature, usually developed using only circular-channel experimental data, predicted the flattened tube results for mass velocities higher than 200 kg/m(2)s with mean absolute error lower than 20% using the equivalent diameter to account for the geometry effect. Similarly, the critical heat flux results were found to be independent of the tube aspect ratio when the same equivalent length was kept. Equivalent length is a new parameter which takes into account the channel heat transfer area. The CHF correlations for round tubes predicted the flattened tube data relatively well when using the equivalent diameter and length. Furthermore, a new proposed CHF correlation predicted the present flattened tube data with a mean absolute error of 5%. (C) 2012 Elsevier Ltd. All rights reserved.

Regionalization and access to healthcare in Brazilian states: historical and political-institutional conditioning factors

This article examines the healthcare regionalization process in the Brazilian states in the period from 2007 to 2010, seeking to identify the conditions that favor or impede this process. Referential analysis of public policies and especially of historical institutionalism was used. Three dimensions sum up the conditioning factors of regionalization: context (historical-structural, political-institutional and conjunctural), directionality (ideology, object, actors, strategies and instruments) and regionalization features (institutionality and governance). The empirical research relied mainly on the analysis of official documents and interviews with key actors in 24 states. Distinct patterns of influence in the states were observed, with regionalization being marked by important gains in institutionality and governance in the period. Nevertheless, inherent difficulties of the contexts prejudice greater advances. There is a pressing need to broaden the territorial focus in government planning and to integrate sectorial policies for medium and long-term regional development in order to empower regionalization and to overcome obstacles to the access to healthcare services in Brazil.

Scientific concepts and public policies: Semiotic-cultural obstacles concerning intergroup and intercultural relationships

I attempt to articulate Jahoda's (2012) critical reflections regarding definitions of culture in recent cross-cultural studies and Moghaddam's (2012) claims of an omnicultural imperative to guide the elaboration of public policies for managing relationships among human groups from different cultural origins. For this, I will approach some aspects of the socio-historical and ontogenetic roots of the notion of culture. The notion of culture and the consequent public policies involving intercultural managing are being transformed as our global society develops. It has been proposed that some ways of dealing with the culture of the other are crucial to achieve awareness in respect of one's own cultural positioning when making science and attempting social interventions. Finally, the experience of Brazilian psychologists working on challenges faced by Amerindians dealing with the national society they live in will be presented as a pioneering work aiming to interfere in the development of public policies ethically concerned with the assurance of cultural integrity of currently marginalized social groups.