5 resultados para Third-order model
Resumo:
This paper presents an extension to the energy vector, well known in the Ambisonics literature, to improve its predictions of localisation at off-centre listening positions. In determining the source direction, a perceptual weight is assigned to each loudspeaker gain, taking into account the relative arrival times, levels, and directions of the loudspeaker signals. The proposed model is evaluated alongside the original energy vector and two binaural models through comparison with the results of recent perceptual studies. The extended version was found to provide results that were at least 50% more accurate than the second best predictor for two experiments involving off-centre listeners with first- and third-order Ambisonics systems.
Resumo:
A novel surrogate model is proposed in lieu of Computational Fluid Dynamics (CFD) solvers, for fast nonlinear aerodynamic and aeroelastic modeling. A nonlinear function is identified on selected interpolation points by
a discrete empirical interpolation method (DEIM). The flow field is then reconstructed using a least square approximation of the flow modes extracted
by proper orthogonal decomposition (POD). The aeroelastic reduce order
model (ROM) is completed by introducing a nonlinear mapping function
between displacements and the DEIM points. The proposed model is investigated to predict the aerodynamic forces due to forced motions using
a N ACA 0012 airfoil undergoing a prescribed pitching oscillation. To investigate aeroelastic problems at transonic conditions, a pitch/plunge airfoil
and a cropped delta wing aeroelastic models are built using linear structural models. The presence of shock-waves triggers the appearance of limit
cycle oscillations (LCO), which the model is able to predict. For all cases
tested, the new ROM shows the ability to replicate the nonlinear aerodynamic forces, structural displacements and reconstruct the complete flow
field with sufficient accuracy at a fraction of the cost of full order CFD
model.
Resumo:
Background: Most qualitative studies exploring the impactof prostate cancer on men and their partners consider the dominant ethnicgroups in the USA, UK, Scandinavia and Australia, with generally concordantfindings. Other ethnic groups are likelyto have different experiences.
Aims: To explorethe impact of prostate cancer and its treatment on men and their partners fromthe less studied ethnic groups.
Methods: Using meta-ethnographyand textual narrative we synthesised peer reviewed qualitative interview-based studiesdated 2000-2015 focused on less well reported ethnic groups, as a sub-synthesisof a comprehensive metasynthesis on the impact of prostate cancer.
Results: Twenty-twopapers (15 studies) covering 11 ethnic groups were analysed. Nine studies considered black and minorityethnic groups in the UK and USA, with the remainder in Brazil, the PacificIslands, Israel, Turkey and Japan. We collected first and second order themesfrom the studies to develop conceptual third order themes with the following specificto the US and UK minority groups andPacific Islanders: A spiritual continuum: from the will of God to God ashelpmate; One more obstacle in the lifelong fight against adversity; Developingsensitive talk with a purpose (on disclosingthe cancer to informal networks in culturally appropriate ways). Themes from theother studies were similar to those in the overall metasynthesis.
Conclusions: Healthcare for prostate cancer should takeaccount of contextually and culturally specific coping mechanisms andpsychosocial factors in minority ethnic groups. More studies are needed indiverse ethnic groups.
Resumo:
This work investigates the production of activated lignin-chitosan extruded (ALiCE) pellets with controlled particle size distribution (almost spherical: dp ~500‒1000µm) for efficient methylene blue adsorption. The novel preparation method employed in this study successfully produced activated lignin-chitosan pellets. Structural and morphological characterizations were performed using BET, FTIR and SEM-EDX analyses. The influence of contact time, solution pH, ionic strength, initial adsorbate concentration and desorption studies was investigated. The experimental data fitted well with the Langmuir isotherm (R2 = 0.997), yielding a maximum adsorption capacity of 36.25mg/g. The kinetic data indicated that methylene blue (MB) adsorption onto ALiCE can be represented by the pseudo second-order-model with intraparticle processes initially controlling the process of MB adsorption. Overall, these results indicate that the novel ALiCE offers great potential for removing cationic organic pollutants from rivers and streams.
