Heat transfer from high-temperature surfaces to fluids II : correlation of heat-transfer and friction data for air flowing in inconel tube with rounded entrance

A heat transfer investigation, which was an extension of a previously reported NACA investigation, was conducted with air flowing through an electrically heated inconel tube with a rounded entrance,an inside diameter of 0.402 inch, and a length of 24 inches over a range of conditions, which included Reynolds numbers up to 500,000, average surface temperatures up to 2050 degrees R, and heat-flux densities up to 150,000 Btu per hour per square foot. Conventional methods of correlating heat-transfer data wherein properties of the air were evaluated at the average bulk, film, and surface temperatures resulted in reductions of Nusselt number of about 38, 46, and 53 percent, respectively, for an increase in surface temperature from 605 degrees to 2050 degrees R at constant Reynolds number. A modified correlation method in which the properties of air were based on the surface temperature and the Reynolds number was modified by substituting the product of the density at the inside tube wall and the bulk velocity for the conventional mass flow per unit cross-sectional area, resulted in a satisfactory correlation of the data for the extended ranges of conditions investigated

Influence of tube-entrance configuration on average heat-transfer coefficients and friction factors for air flowing in an Inconel tube

A heat-transfer investigation was conducted with air flowing through an electrically heated Inconel tube having either a long-approach or a right-angle-edge entrance, an inside diameter of 0.402 inch, and a length of 24 inches over a range of Reynolds numbers up to 375,000 and average inside-tube-wall temperatures up to 2000 degrees R. Good correlation of heat-transfer data was obtained for both entrances, which substantiates work previously reported. A fair correlation of friction data was obtained for both entrances. The entrance configuration had little effect on the average heat-transfer and friction coefficients

Laser damage testing at LLL: an overview and an update

Damage thresholds for single layers of common coating materials such as MgF/sub 2/, SiO/sub 2/, ThF/sub 4/, Al/sub 2/O/sub 3/, ZrO/sub 2/, and TiO/sub 2/ are given. Laser-induced damage of coated and uncoated optically polished surfaces has been studied at LLL for laser pulsewidths between 0.17 ns and 3 ns. Two 1064 nm Nd lasers generated this range of pulsewidths. This report contains a review of the results. (MOW

Koinonia

Best Practices FeaturesStudents of Concern Committee: Coordinating Care, Connie Horton and Mark Davis Want to Change Student Culture on Your Campus? Do the CORE!, Eric Lowdermilk Spotlight FeaturesYou Only Get 1 Up, Justin Heth and Caleb Farmer The Season, Sharon Virkler Book ReviewsThe Future of Christian Learning: An Evangelical and Catholic Dialogue (by Mark Noll and James Turner), reviewed by Philip D. Byers Restoring Rebecca: A Story of Traumatic Stress, Caregiving and the Unmasking of a Superhero (by Christopher Marchand), reviewed by David M. Johnstone A Review of Culture Making: Recovering our Creative Calling (by Andy Crouch), reviewed by Jeff Rioux Revisiting How Minority Students Experience College: Implications for Planning and Policy (by LKemuel Watson, Melvin Terrell, Doris Wright, Fred Bonner II, Michael Cuyjet, James Gold, Donna Rudy and Dawn Person), reviewed by Joshua Canada Excerpts from Breathe: Finding Freedom to Thrive in Relationships after Childhood Sexual Abuse, Nicole Braddock Bromley ReflectionsMy Journey into Student Affairs, Kim Stave FeaturesThe President\u27s Corner Editor\u27s Deskhttps://pillars.taylor.edu/acsd_koinonia/1079/thumbnail.jp

Correlations, Causes and the Logic of Obscuration: Donor Shaping of Dominant Narratives in Indonesia's Irrigation Development

This article analyses policy trends in Indonesian irrigation, particularly during the last five decades, from the perspective of dominant narratives, as authored, suggested and pushed by international donors. It argues that international donors' adherence to ‘deferred maintenance’ as the core element of irrigation policy problem framing does not match with farmers' and the irrigation agency staff perceptions and practices. The logic of obscuration and the discursive manoeuvers that maintain it are analysed. The article concludes that there is space for more profound conceptual contestation and for alternative actions pathways even within the ‘dominant paradigm’ to address management problems more effectively

user centered design approaches and methods for p5 ehealth

As seen throughout this book, eHealth informed by P5 approach gives full recognition to patients' contexts, needs, desires, and personal characteristics. These aspects should not only be considered as cornerstones for technology evaluation, but as fundamental guidelines for design in the first place. This relates to User-Centered Design, that is, any technology/service design where final users influence how the design itself takes place. In other words, eHealth development should be based on research data gathered among final users about their needs and contexts of use, in order to be specifically tailored on final users even before the realization of low-level prototypes. This methodological contribution presents a critical presentation, description, and evaluation of research tools to be employed not to evaluate technology's results and effectiveness, but the specific characteristics of users in order to orient design and development. Such an approach should be considered the "gold standard" of P5 eHealth solutions

Population, resources, and environment: Implications of human behavioral ecology for conservation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43481/1/11111_2005_Article_BF02207996.pd