Baseline correction methods based on penalized least squares are successfully applied to various spectral analyses. The methods change the weights iteratively by estimating a baseline. If a signal is below a previously fitted baseline, large weight is given. On the other hand, no weight or small weight is given when a signal is above a fitted baseline as it could be assumed to be a part of the peak. As noise is distributed above the baseline as well as below the baseline, however, it is desirable to give the same or similar weights in either case. For the purpose, we propose a new weighting scheme based on the generalized logistic function. The proposed method estimates the noise level iteratively and adjusts the weights correspondingly. According to the experimental results with simulated spectra and measured Raman spectra, the proposed method outperforms the existing methods for baseline correction and peak height estimation.

Baseline correction using asymmetrically reweighted penalized least squares smoothing

The aim of the present work is to prepare an adsorption package to simulate adsorption / desorption operation for both single and multi-component systems in an isothermal condition by different mechanisms such as; local adsorption theory and mass transfer resistance (rigorous and approximated methods). Different mass transfer resistance mechanisms of pore, solid and bidispersed diffusion, together with nonlinear isotherms (Longmuir, Frendlich, Sips and Toth) are taken into account in modeling the fixed bed adsorbers. The Extended Longmuir isotherm was found to explain properly the binary and ternary mixtures in adsorption/desorption process.Almost all the mass transfer approximations were explained by the linear driving force, LDF,  although the alternative driving force, ADF, approximation was examined in some cases. The numerical solution was the Implicit Method of Lines which converted the partial differential equations to the ODEs then solving them by the Runge-Kutta method. Validation of the models was performed by the experimental data derived from the literature for different types of adsorbents and adsorbates. The sensitivity analyses was carried out to find out variation of the breakthrough curves against some physical and operational parameters such as; temperature, flow rate, initial and  inlet concentration and particle adsorbent size. The results revealed excellent agreement of simulated and previously published experimental data.

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Mathematical Modeling of Single and Multi-Component Adsorption Fixed Beds to Rigorously Predict the Mass Transfer Zone and Breakthrough Curves

Portfolio optimization is an important research field in modern finance. The most important characteristic within this optimization problem is the risk and the returns. Modern portfolio theory provides a well-developed paradigm to form a portfolio with the highest expected return for a given level of risk tolerance. Multi objective portfolio optimization problem is the portfolio selection process that result highest expected return and smallest identified risk among the various financial assets.

Resolving multi objective stock portfolio optimization problem using genetic algorithm

Abstract Present research article reports the magnetized impacts of Cattaneo-Christov double diffusion models on heat and mass transfer behaviour of viscous incompressible, time-dependent, two-dimensional Casson nanofluid flow through the channel with Joule heating and viscous dissipation effects numerically. The classical transport models such as Fourier and Fick’s laws of heat and mass diffusions are generalized in terms of Cattaneo-Christov double diffusion models by accounting the thermal and concentration relaxation times. The present physical problem is examined in the presence of Lorentz forces to investigate the effects of magnetic field on double diffusion process along with Joule heating. The non-Newtonian Casson nanofluid flow between two parallel plates gives the system of time-dependent, highly nonlinear, coupled partial differential equations and is solved by utilizing RK-SM and bvp4c schemes. Present results show that, the temperature and concentration distributions are fewer in case of Cattaneo-Christov heat and mass flux models when compared to the Fourier’s and Fick’s laws of heat and mass diffusions. The concentration field is a diminishing function of thermophoresis parameter and it is an increasing function of Brownian motion parameter. Finally, an excellent comparison between the present solutions and previously published results show the accuracy of the results and methods used to achieve the objective of the present work.

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A generalized perspective of Fourier and Fick’s laws: Magnetized effects of Cattaneo-Christov models on transient nanofluid flow between two parallel plates with Brownian motion and thermophoresis

This paper describes the development of a mesh deformation method used for aero-thermo-mechanical coupling of turbo-engine components. The method is based on the nonlinear solution of an elastic medium analogy, solved using finite element discretisation and modified to let the boundary nodes be free to slide over the deflected surfaces. This sliding technique relies on a B-spline reconstruction of the moving boundary and increases the robustness of the method in situations where the boundary deflection field presents significant gradients or large relative motion between two distinct boundaries. The performance of the method is illustrated with the application to an interstage cavity of a turbine assembly, subjected to the deformations computed by a coupled thermo-mechanical analysis of the engine component.

Jaan Kiusalaas

Papers

Numerical Methods in Engineering with MATLAB®: Symmetric Matrix Eigenvalue Problems