An Experimental Study of Airfoil Icing Characteristics

A full scale general aviation wing with a NACA 63 sub 2 A415 airfoil section was tested to determine icing characteristics for representative rime and glaze icing conditions. Measurements were made of ice accretion shapes and resultant wing section drag coefficient levels. It was found that the NACA 63 sub 2 A415 wing section was less sensitive to rime and glaze icing encounters for climb conditions

Mass transport phenomena between bubbles and dissolved gases in liquids under reduced gravity conditions

The experimental and analytical work that was done to establish justification and feasibility for a shuttle middeck experiment involving mass transfer between a gas bubble and a liquid is described. The experiment involves the observation and measurement of the dissolution of an isolated immobile gas bubble of specified size and composition in a thermostatted solvent liquid of known concentration in the reduced gravity environment of earth orbit. Methods to generate and deploy the bubble were successful both in normal gravity using mutually buoyant fluids and under reduced gravity conditions in the NASA Lear Jet. Initialization of the experiment with a bubble of a prescribed size and composition in a liquid of known concentration was accomplished using the concept of unstable equilibrium. Subsequent bubble dissolution or growth is obtained by a step increase or decrease in the liquid pressure. A numerical model was developed which simulates the bubble dynamics and can be used to determine molecular parameters by comparison with the experimental data. The primary objective of the experiment is the elimination of convective effects that occur in normal gravity

Transition of planar Couette flow at infinite Reynolds numbers

An outline of the state space of planar Couette flow at high Reynolds numbers (Re<105) is investigated via a variety of efficient numerical techniques. It is verified from nonlinear analysis that the lower branch of the hairpin vortex state (HVS) asymptotically approaches the primary (laminar) state with increasing Re. It is also predicted that the lower branch of the HVS at high Re belongs to the stability boundary that initiates a transition to turbulence, and that one of the unstable manifolds of the lower branch of HVS lies on the boundary. These facts suggest HVS may provide a criterion to estimate a minimum perturbation arising transition to turbulent states at the infinite Re limit. © 2013 American Physical Society

Low temperature oxide desorption in GaAs (111)A substrates

Trabajo presentado al 17th european Molecular Beam Epitaxy Workshop celebrado en Levi (Finlandia) del 10 al 13 de Marzo de 2013.Peer Reviewe

Health-related quality of life and mortality in the 'Seguimiento Universidad de Navarra' prospective cohort study

Objective: To study the association between health-related quality of life (HRQoL) and all-cause mortality in a healthy middle-aged Mediterranean cohort. Methods: We included 15,390 participants –mean age 42.8 years at first HRQoL ascertainment, all university graduates–. HRQoL was assessed with the self-administered Medical Outcomes Study Short Form-36 (SF-36) twice, with a 4-year gap. We used multivariable-adjusted Cox regression models to address the relation between self-reported health and Physical or Mental Component Summary (PCS-36 or MCS-36) and mortality, and their interaction with prior comorbidities or adherence to the Mediterranean diet (MedDiet). Results: Over 8.7 years of median follow-up time, 266 deaths were identified. Hazard ratio (HR) for the excellent vs. poor/fair category in self-reported health was 0.30 (95 % confidence interval (CI), 0.16–0.57) in the model with repeated measurements of HRQoL. Both the PCS-36 (HRquartile4(Q4)vs.Q1 0.57 [95%CI, 0.36–0.90], ptrend < 0.001; HRper+10points: 0.64 [95%CI, 0.54–0.75]) and the MCS-36 (HRQ4vs.Q1 0.67 [95%CI, 0.46–0.97], ptrend = 0.025; HRper+10points: 0.86 [95%CI, 0.74–0.99]) were inversely associated with mortality in the model with repeated measurements of HRQoL. Previous comorbidities or adherence to the MedDiet did not modify these associations. Conclusions: Self-reported HRQoL –assessed as self-reported health, PCS-36 and MCS-36– obtained with the Spanish version of the SF-36 were inversely associated with mortality risk, regardless of the presence of previous comorbidities or adherence to the MedDiet.This project was made possible by funding from the Spanish Government-Instituto de Salud Carlos III, and the European Regional Development Fund (FEDER) (RD 06/0045, CIBER-OBN, Grants PI10/02658, PI10/02293, PI13/00615, PI14/01668, PI14/01798, PI14/01764, PI17/01795, PI18/00631, PI20/00564 and G03/140), from the Government of Navarra (27/2011, 45/2011, 122/2014), from the National Plan on Drugs (2020/021) as well as from the University of Navarra

Development and validation of a questionnaire to evaluate lifestyle-related behaviors in elementary school children

Background The SI! Program promotes cardiovascular health through a multilevel school-based intervention on four lifestyle-related components: diet, physical activity, understanding the body and heart, and management of emotions. We report here the development and validation of the KAH (knowledge, attitudes and habits)-questionnaire adapted for elementary school children (6-7 years old) as a tool for the forthcoming evaluation of the SI! Program, where the KAH scoring will be the primary outcome. The efficacy of such an intervention will be based on the improvements in children's KAH towards a healthy lifestyle. Methods The questionnaire validation process started with a pool of items proposed by the pedagogical team who developed the SI! Program for elementary school. The questionnaire was finalized by decreasing the number of items from 155 to 48 using expert panels and statistical tests on the responses from 384 children (ages 6-7). A team of specialized psychologists administered the questionnaire at schools providing standard directions for the final administration. The internal consistency was assessed using Cronbach's α coefficients. Reliability was measured through the split-half method, and problematic items were detected applying the item response theory. Analysis of variance and Tukey's test of additivity were used for multiple comparisons. Results The final KAH-questionnaire for elementary school children should be administered to children individually by trained staff. The 48 items-questionnaire is divided evenly between the 4 components of the intervention, with an overall Cronbach's α = 0.791 (α = 0.526 for diet, α = 0.537 for physical activity, α = 0.523 for human body and heart, and α = 0.537 for management of emotions). Conclusions The KAH-questionnaire is a reliable instrument to assess the efficacy of the SI! Program on instilling healthy lifestyle-related behaviors in elementary school children