Global,local and unique decompositions in OnPLS for multiblock data analysis

OnPLS is an extension of O2PLS that decomposes a set of matrices, in either multiblock or path model analysis, such that each matrix consists of two parts: a globally joint part containing variation shared with all other connected matrices, and a part that contains locally joint and unique variation, i.e. variation that is shared with some, but not all, other connected matrices or that is unique in a single matrix.     

Rapid estimation of global sugars by UV photodegradation and UV spectrophotometry

The UV/UV method developed for the measurement of specific wastewater pollution parameters (ammonium, Kjeldahl nitrogen, total phosphorus) is adapted to the determination of sugars in fruit juices and soft drinks. The procedure is based on the UV spectrophotometric detection of by-products of UV photodegradation of carbohydrates. Time of analysis is greatly reduced by using specific pH conditions and diluted samples.     

Advancements and potentials of molten salt CO2 capture and electrochemical transformation (MSCC-ET) process

Electroreduction of CO₂ in molten salts, also called molten salt carbon capture and electrochemical transformation (MSCC-ET), can convert CO₂ into value-added carbonaceous materials or CO in a comparably high rate with high energy efficiency. It shows a promising potential to contribute to the earth's atmospheric carbon balance, the intermittent renewable energy storage, carbon materials production, and air quality control of the local environment. This short review briefly introduces the principle of the MSCC-ET process, the state-of-the-art of the process, its potential of commercialization in terms of process efficiency, product marketing and economy, and finally, the opportunities and challenges in future research and development.     

A new formulation of immiscible compressible two-phase flow in porous media

A new formulation is proposed to describe immiscible compressible two-phase flow in porous media. The main feature of this formulation is the introduction of a global pressure. The resulting equations are written in a fractional flow formulation and lead to a coupled system which consists of a nonlinear parabolic (the global pressure equation) and a nonlinear diffusion–convection one (the saturation equation) which can be efficiently solved numerically. To cite this article: B. Amaziane, M. Jurak, C. R. Mecanique 336 (2008).     

On the global solutions to two-phase nonequilibrium problems

In this paper, we consider a Stefan-like problem with a kinetic condition on the free boundary, i.e. a two-phase nonequilibrium problem in one dimension, and prove that it has a unique classical and global solution under some conditions. We also investigate the travelling wave solutions.

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Sommario In questo lavoro si considera un problema tipo Stefan con una condizione cinetica sul bordo libero, cioc' un problema di non equilibrio a due fasi in una dimensione. Si dimostra che, sotto opportune condizioni, il problema ammette una unica soluzione globale di tipo classico. Sono altresi' analizate soluzioni ad onde viaggianti.

     

Interactive buckling in long thin-walled rectangular hollow section struts

An analytical model describing the nonlinear interaction between global and local buckling modes in long thin-walled rectangular hollow section struts under pure compression founded on variational principles is presented. A system of nonlinear differential and integral equations subject to boundary conditions is formulated and solved using numerical continuation techniques. For the first time, the equilibrium behaviour of such struts with different cross-section joint rigidities is highlighted with characteristically unstable interactive buckling paths and a progressive change in the local buckling wavelength. With increasing joint rigidity within the cross-section, the severity of the unstable post-buckling behaviour is shown to be mollified. The results from the analytical model are validated using a nonlinear finite element model developed within the commercial package Abaqus and show excellent comparisons. A simplified method to calculate the local buckling load of the more compressed web undergoing global buckling and the corresponding global mode amplitude at the secondary bifurcation is also developed. Parametric studies on the effect of varying the length and cross-section aspect ratio are also presented that demonstrate the effectiveness of the currently developed models.     

Large-eddy simulation of low-frequency unsteadiness in a turbulent shock-induced separation bubble

The need for better understanding of the low-frequency unsteadiness observed in shock wave/turbulent boundary layer interactions has been driving research in this area for several decades. We present here a large-eddy simulation investigation of the interaction between an impinging oblique shock and a Mach 2.3 turbulent boundary layer. Contrary to past large-eddy simulation investigations on shock/turbulent boundary layer interactions, we have used an inflow technique which does not introduce any energetically significant low frequencies into the domain, hence avoiding possible interference with the shock/boundary layer interaction system. The large-eddy simulation has been run for much longer times than previous computational studies making a Fourier analysis of the low frequency possible. The broadband and energetic low-frequency component found in the interaction is in excellent agreement with the experimental findings. Furthermore, a linear stability analysis of the mean flow was performed and a stationary unstable global mode was found. The long-run large-eddy simulation data were analyzed and a phase change in the wall pressure fluctuations was related to the global-mode structure, leading to a possible driving mechanism for the observed low-frequency motions.