Predicting the whiteness index of cotton fabric with a least squares model

Cellulose - The textile bleaching process that involves hot hydrogen peroxide (H2O2) solution is commonly practised in cotton fabric manufacture. The purpose of the bleaching process is to remove...     

Iterative methods for a class of variational inequalities in Hilbert spaces

In this paper, we introduce implicit and explicit iterative methods for solving a variational inequality problem over the set of zeros for a maximal monotone mapping in Hilbert spaces. As consequence, new modifications of the proximal point method are obtained.     

Reciprocal Response of Human Oral Epithelial Cells to Internalized Silica Nanoparticles

Silica nanoparticles (SiO₂ NPs) are one of the most widely used engineered nanoparticles and can been found in a wide range of consumer products. Despite their massive global production scale, little is known about their potential effects in the context of unintended exposure or ingestion. Using TR146 cells as an in vitro model of the human oral buccal mucosa, the uptake, spatial intracellular distribution, reactive oxygen species (ROS) production, inflammatory response, and cytotoxic effects of commercial SiO₂ NPs are examined. SiO₂ NPs are shown to dock and cross the cellular membrane barrier in a dose–time‐dependent manner. Confocal sectioning reveals translocation of SiO₂ NPs into the cell nucleus after 12 h of exposure. A concentration threshold of more than 500 × 10^?6 m is observed, above which SiO₂ NPs are shown to exert significant oxidative stress with concomitant upregulation of inflammatory genes IL6 and TNFA. Further analysis of the p53 pathway and a series of apoptotic and cell cycle biomarkers reveals intracellular accumulation of SiO₂ NPs exert marginal nanotoxicity. Collectively, this study provides important information regarding the uptake, intracellular distribution, and potential adverse cellular effects of SiO₂ NPs commonly found in consumer products in the human oral epithelium.     

A steepest-descent Krasnosel’skii–Mann algorithm for a class of variational inequalities in Banach spaces

In this paper, in order to solve a variational inequality problem over the fixed point set of a nonexpansive mapping on uniformly smooth or reflexive and strictly convex Banach spaces with a uniformly Gâteaux differentiable norm, we investigate an explicit iteration method, based on the steepest-descent and Krasnosel’skii–Mann algorithms. We also show that some modifications of the last and Halpern-type algorithms are special cases of our result.     

A new explicit iteration method for a class of variational inequalities

In this paper, we propose a new simple explicit iterative algorithm to find a solution for variational inequalities over the set of common fixed points of an infinite family of nonexpansive mappings on real reflexive and strictly convex Banach spaces with a uniformly Gâteaux differentiable norm. Two numerical examples also are given for illustration.     

Discrepancy Principle and Convergence Rates in Regularization of Monotone Ill-Posed Problems

The convergence rates of the regularized solution as well as its Galerkin approximations for nonlinear monotone ill-posed problems in a Banach space are established on the basis of the choice of a regularization parameter by the Morozov discrepancy principle.     

Comparison of variants of the bi-conjugate gradient method for compressible Navier-Stokes solver with second-moment closure

Variants of the bi-conjugate gradient (Bi-CG) method are used to resolve the problem of slow convergence in CFD when it is applied to complex flow field simulation using higher-order turbulence models. In this study the Navier-Stokes and Reynolds stress transport equations are discretized with an implicit, total variation diminishing (TVD), finite volume formulation. The preconditioning technique of incomplete lower-upper (ILU) factorization is incorporated into the conjugate gradient square (CGS), bi-conjugate gradient stable (Bi-CGSTAB) and transpose-free quasi-minimal residual (TFQMR) algorithms to accelerate convergence of the overall itertive methods. Computations have been carried out for separated flow fields over transonic bumps, supersonic bases and supersonic compression corners. By comparisons of the convergence rate with each other and with the conventional approximate factorization (AF) method it is shown that the Bi-CGSTAB method gives the most efficient convergence rate among these methods and can speed up the CPU time by a factor of 2·4–6·5 as compared with the AF method. Moreover, the AF method may yield somewhat different results from variants of the Bi-CG method owing to the factorization error which introduces a higher level of convergence criterion.     

Regularization methods for a class of variational inequalities in banach spaces

In this paper, we introduce two regularization methods, based on the Browder-Tikhonov and iterative regularizations, for finding a solution of variational inequalities over the set of common fixed points of an infinite family of nonexpansive mappings on real reflexive and strictly convex Banach spaces with a uniformly Gateaux differentiate norm.     

Hybrid Mann-Halpern iteration methods for nonexpansive mappings and semigroups

In this paper, we introduce some new iteration methods based on the hybrid method in mathematical programming, the Mann’s iterative method and the Halpern’s method for finding a fixed point of a nonexpansive mapping and a common fixed point of a nonexpansive semigroup Hilbert spaces.     

Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement

Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.