Search results

STRIPE — Scanning Triangulation Range Imaging Package for Engineering is examined by the National Engineering Laboratory.

This study aims to couple two codes, one able to perform icing simulations and another one capable to simulate the performance of an electrothermal anti-icing system in an integrated fashion.

The classical tool chain of icing simulation (aerodynamics, water catch and impact, mass and energy surface balance) is coupled to the thermal analysis through the surface substrate and the ice thickness. In the present approach, the ice protection simulation is not decoupled from the ice accretion simulation, but a single computational workflow is considered.

A fast approach to simulate advanced anti-icing systems is found in this study.

This study shows the validation of present procedure against literature data, both experimental and numerical.

Dietary fiber and energy intakes seem to be related to disability and anthropometric indices in multiple sclerosis (MS), a chronic inflammatory disorder of the central nervous system. So, this study was designed to investigate the association between dietary fiber and energy intakes with systemic inflammation, disease severity and anthropometric measurements in MS subjects.

Four subtypes of 261 MS volunteers were recruited (female = 210, male = 51; mean age 38.9 ± 8.3). A 168-item food frequency questionnaire and nutritionist IV software were used to estimate the amounts of dietary, insoluble, soluble, crude fiber and energy intakes. Serum hs-CRP, extended disability status scale (EDSS), height, weight and Deurenberg equation were also used to evaluate systemic inflammation, disease severity, body mass index (BMI) and percentage body fat, respectively.

Mean differences among the three hs-CRP and EDSS subgroups for dietary fibers and energy intake were significant (p < 0.001). Dietary fiber intake (M = 19.9 ± 4.3 g/day) was a good predictor for EDSS (B = −0.196, p = 0.012), and insoluble fiber intake was introduced as the best predictor of hs-CRP (B = −3.293, p < 0.001). Energy intake predicted both BMI (B = 0.007, p < 0.001) and percentage body fat (B = 0.015, p < 0.001).

Hypocaloric and high prebiotic fiber diet may suppress systemic inflammation and thereby modulate disease severity, as well as control anthropometric indices.

The aim of this paper is to present a Eulerian–Lagrangian model of aircraft ground deicing that avoids the scale’s dispersion problem caused by the great distance between the spray nozzle and the surface to be deiced. Verification is done using the case of a hot particle liquid spray impinging on a horizontal flat plate. The impinged particles flow outwards radially from the impingement zone and form a hot film wall. The computed wall heat distribution is verified. In the end, an inclination spray’s angle study is presented.

The problem is divided into two regions. First, a 3D region is created for the evolution of the Lagrangian particles spray. A second 2D region is provided for the formation of a liquid film. The two regions exchange mass, momentum and energy through an interface. Heat losses are modelled through particles and liquid-film cooling and evaporation, particles splash and heat transfer to a fixed temperature plate.

For a chamber pressure of 1 bar, the predicted spray penetration is within 10 per cent of the experimental results. For this study case, the heat transfer is maximized with an inclination angle of approximately 30° of the spray.

The model presented makes it possible to simulate the impingement and heat transfer of a large-scale liquid spray with a reasonable computational cost. To the best of the authors’ knowledge, this model is a first attempt of the computational fluid dynamics simulation of ground deicing.

This chapter explores methodological aspects of designing a qualitative multi-case research study to examine the issues of citizen participation, new democratic forms of planning, and community tourism planning. The study discussed below took place during the months of June 2007–March 2008 in three North American communities – two in the United States and one in Canada. The purposes of the study were to compare and contrast the current practices of citizen involvement in community tourism planning with the framework of deliberative democracy, to expand the literature on tourism planning, and to contribute to the development of a model of participatory community tourism planning to be adopted by communities and planners pursuing tourism as a development tool. This chapter focuses on methodological intricacies of designing a qualitative multi-case research study, those wishing to explore the project more are referred to Grybovych (2008).

There are many studies regarding the value of gaining cultural awareness, but limited empirical evidence has been shared on programs that use integrated learning and capacity building interventions to specifically build cultural competence in aspiring undergraduate leaders. This qualitative case study examined the effects of interventions designed to build intercultural competence in first-year honors students participating in a leadership development program using co-curricular activities, undergraduate research, and a short-term education abroad. Data collected from two cohorts who completed the first year of the program revealed students’ perceptions of their short-term education abroad experience’s impact on their intercultural competence and leadership development. The study demonstrates the value of integrated leadership and intercultural competence development among undergraduate students.

Rural populations have traditionally received less attention in Britain than their urban counterparts, and little research into their problems has been undertaken. Identifies and discusses potential problems in the provision of quality health care in rural areas, based on interviews with five senior NHS managers and supported by information from relevant published literature. Identifies trade‐offs between the various dimensions of quality which can occur in rural areas, and argues that they should be based on objective information and be undertaken explicitly.

This study aims to examine the effect of family ownership on audit fees and whether political connections moderate the causal relationship. Indonesia, as emerging countries, arguably offers appropriate research setting for this research because most Indonesian firms are family owned and exhibit weak investor protection. The authors predict that family ownership positively affects audit fees, and political connections strengthen this influence.

This study uses 98 listed manufacturing firms on Indonesia Stock Exchange (IDX) in 2018–2020, resulting in 279 firm-year observations. Panel data regression used to test the hypothesis. Family ownership is divided into direct and indirect ownership while audit fees are measured by the natural logarithm of audit fees paid by the firms.

The results show that the greater total and direct family ownerships imply lower audit fees, while indirect family ownership does not affect audit fees. The finding is contrary to the alleged hypothesis. Further, political connections only strengthen direct family ownership's negative impact on audit fees.

This study's findings support the alignment effect hypothesis arguing that controlling shareholders, in this case, families, align their interests with non-controlling shareholders. These findings provide a different perspective from various empirical studies conducted in Asian countries where the majority of companies are also controlled.

The purpose of this paper is to advance the multiphysics analysis of helicopter rotors under icing conditions by coupling the iced rotor’s aerodynamics, analyzed by CFD, with the rotor’s structural characteristics, analyzed by CSD.

The current work introduces supercomputer-based computational approaches capable of assessing the impact of ice accretion on the aerodynamics, blade dynamics, vibrations and loading of a rotorcraft. The rigid and elastic motions of the blades are accounted for through a loose coupling of the flow solver to a multibody dynamics solver. The coupling framework allows for comprehensive aeroelastic simulations of iced rotors in hover and in forward flight.

The flow and structural modules were validated on a full helicopter configuration in forward flight using the ROBIN experimental model. The tip structural deflections were in very close agreement with the experimental measurements.

The results of the CFD analyses are limited by the available experimental results they can be compared to. In dry air CFD, three-dimensional (3D) experiments occur first and CFD is then compared to them; in icing, the opposite is true: 3D experiments (if they are ever done, as they are very expensive) chase CFD and sometimes never occur.

This paper presents an outline of how CFD and computational stress dynamics (CSD) analyses can be linked and provides a toolbox for deeper investigation of the complex flows over helicopters operating under difficult in-flight icing conditions.

More and more helicopters are designed to be able to operate in hostile environments such as rescuing and saving lives over the oceans or mountains, conditions under which icing encounters cannot be avoided.

A loosely coupled CFD/CSD framework that accounts for the rotor blades structural response to aerodynamic loading and ice accretion in hover and forward flight has been presented. This versatile and cost-effective framework provides a more accurate estimation of the helicopter rotor performance and its degradation due to icing encounters during the early design stages than traditional CFD tools.