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For many years, the use of complex surfaces is becoming widespread with the development of manufacturing process. CAD model describes nominal shape of the part. Specifications are then defined by annotations directly in the 3D model. This work is illustrated by an application on a turbine blade of an aircraft engine. To impose the widest possible tolerances on the whole surface, it is necessary to have a multi-scale approach. The main datum reference frame is built on the setting up surfaces of the part. In the first level, all surfaces are located with regard to the main datum reference frame with a wide tolerance in order to avoid interference with other parts of the mechanism. In a second level, specifications on restricted areas complete local requirements with lower tolerances. In the third level, orientation specification on small mobile zone with small tolerance detects micro defects as tool traces for example. This presentation shows several positions, orientation and form specifications on 3D surfaces and on 2D curves. The new modifier “For orientation constraint only” of the ISO 5459: 2011 standard lets us define only the orientation with regard to a reference surface. The overlapping of many orientation specifications on restricted areas limits parts defects inside a large global tolerance zone. Specifications with common zone of two surfaces face to face control the thickness of the part which can be useful for strength or mass reasons. These specifications can be detailed with a variable tolerance zone that defines the tolerance of all points of surfaces. The ISO standard only treats the 2D case; this paper presents a solution to specify 3D surfaces with variable tolerance by a hypothesis of proportional variation following the curvilinear distance on curves created on 3D surfaces. This set of specifications constitutes a tool-box for designers based on only one type of specification which allows them to verify all requirements with a partition of only one cloud of points. The 3D complex surfaces are the interface between the part and the outside environment and often require similar functions. This study in a context of aeronautic industry can easily be extended to other mechanical domains. [ABSTRACT FROM AUTHOR]

In this paper it is continued an analysis of blade design solutions for small power Vertical Axis Wind Turbines (VAWTs), investigating the best solution for a new design that has as objective the minimisation of vibrations, loads, and augmentation of power. It is investigated a classical Darrieus rotor with a NACA0018 blade profile, and then, it is studied the influence of blade flaps on the performance of the aerodynamic profile, aiming to improve the blade lift curve and the CL/CD ratio. It is concluded that the flaps are proven to be an optimized solution in view of aerodynamic performance of the profile, but only up to a certain angle, and thus, it encourages the further studies regarding their feasibility and their effect on the turbine performance. [ABSTRACT FROM AUTHOR]

Highlights: [•] The presence of a line of tall vehicles in the bridge aeroelastic behavior is investigated. [•] The used CFD techniques reproduced 2D vortex-induced bridge oscillations. [•] The presence of a line of tall vehicles increases amplitude of oscillations. [•] The presence of vehicles does not significantly change the critical wind velocity. [Copyright &y& Elsevier]

[Display omitted] • Dry powder inhalers were developed for drug the delivery using nanotechnology. • Nanoparticles were synthesized using hyaluronic acid along with chitosan. • Also, hyaluronic acid was used with chitosan derivatives to prepare nanoparticles. • Spray-drying and freeze-drying were used as drying techniques to obtain nanopowders. • Stochastic lung model exhibited particle deposition in the lungs. • Drying techniques show small changes in sample profiles upon characterization. Dry powder inhalers (DPIs) are already on market, however, none of the DPIs are present for the treatment of tuberculosis. Herein, isoniazid-loaded nanopowders were developed for the delivery to the deeper lung tissues, more precisely alveoli. Chitosan (CS), thiolated chitosan (TC), and mannosylated chitosan (MC) were used individually in conjugation with hyaluronic acid (HA) because of their affinity for the pulmonary epithelium and alveolar macrophages. Here, the densities, Carr's index, fine particle fraction (FPF), mass median aerodynamic diameter (MMAD), and in-silico behavior were examined by employing two drying techniques (freeze-drying and spray-drying) for nanopowders. During a preliminary evaluation, no significant difference was observed in the aerodynamic and in-silico profiles of the nanopowders produced by either drying technique. Nanopowders posed no toxicity to A549 cells as demonstrated by the MTT assay. Overall, the particle deposition profile was found to be promising for all the freeze-dried samples and spray-dried samples containing mannitol. [ABSTRACT FROM AUTHOR]