Selection of individual variables versus intervals of variables in PLSR

The selection abilities of the two well‐known techniques of variable selection, synergy interval‐partial least‐squares (SiPLS) and genetic algorithm‐partial least‐squares (GA‐PLS), have been examined and compared. By using different simulated and real (corn and metabolite) datasets, keeping in view the spectral overlapping of the components, the influence of the selection of either intervals of variables or individual variables on the prediction performances was examined. In the simulated datasets, with decrease in the overlapping of the spectra of components and cases with components of narrow bands, GA‐PLS results were better. In contrast, the performance of SiPLS was higher for data of intermediate overlapping. For mixtures of high overlapping analytes, GA‐PLS showed slightly better performance. However, significant differences between the results of the two selection methods were not observed in most of the cases. Although SiPLS resulted in slightly better performance of prediction in the case of corn dataset except for the prediction of the moisture content, the improvement obtained by SiPLS compared with that by GA‐PLS was not significant. For real data of less overlapped components (metabolite dataset), GA‐PLS that tends to select far fewer variables did not give significantly better root mean square error of cross‐validation (RMSECV), cross‐validated R² (Q²), and root mean square error of prediction (RMSEP) compared with SiPLS. Irrespective of the type of dataset, GA‐PLS resulted in models with fewer latent variables (LVs). When comparing the computational time of the methods, GA‐PLS is considered superior to SiPLS. Copyright © 2010 John Wiley & Sons, Ltd.     

Products of resolvents and multivalued hybrid mappings in CAT(0) spaces

In this article, we introduce and investigate the concept of multivalued hybrid mappings in CAT(0) spaces by using the concept of quasilinearization. Also, we present a new iterative algorithm involving products of Moreau-Yosida resolvents for finding a common element of the set of minimizers of a finite family of convex functions and a common fixed point of two multivalued hybrid mappings in CAT(0) spaces.     

Using empirical Eigenfunctions and Galerkin method to two‐phase transport models

In this article, we consider a nonlinear partial differential system describing two‐phase transports and try to recover the source term and the nonlinear diffusion term when the state variable is known at different profile times. To this end, we use a POD‐Galerkin procedure in which the proper orthogonal decomposition technique is applied to the ensemble of solutions to derive empirical eigenfunctions. These empirical eigenfunctions are then used as basis functions within a Galerkin method to transform the partial differential equation into a set of ordinary differential equations. Finally, the validation of the used method has been evaluated by some numerical examples. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 456–474, 2007     

Preparation of Iodide Selective Carbon Paste Electrode with Modified Carbon Nanotubes by Potentiometric Method and Effect of CuS‐NPs on Its Response

In this research, multiwalled carbon nanotubes (MWCNTs) was oxidized and chemically modified through reaction with 3‐(trimethoxysilyl)propan‐1‐amine (TMSPA) and their subsequent reaction with 2‐hydroxy‐3‐methoxy benzaldehyde. Subsequently, this material was metalized by reaction with copper acetate that lead to formation and impergeation of 2‐methoxy‐6‐((3‐(trimethoxysilyl)propylimino)methyl)phenol MMSPIMP? MWCNT‐Cu. This novel material was identified with different techniques such as SEM and FT‐IR analysis. In this work, the reported material are exhibited high accurate and repeatable monitoring of iodide due to its high surface area with various reactive centre. It exhibited selectivity for iodide over the wide linear dynamic range between 1.8×10^?6 and 1.15×10^?1 M, with a Nernstian slope of ?59.12±0.7 mV per decade of activity and detection limit of 1.8×10^?6 M. Copper sulfide nanoparticles were prepared and their effect on the electrode response was investigated. The results were improved in the presence of nanoparticles with fast and stable response, good reproducibility, long‐term stability, high selectivity over the presence of common organic and inorganic anions, high detection limit and dynamic range. The proposed sensor has been applied as potentiometric determination of some iodine species over a pH range of 2.5–10.     

Skew products of interval maps over subshifts

We treat step skew products over transitive subshifts of finite type with interval fibers. The fiber maps are diffeomorphisms on the interval; we assume that the end points of the interval are fixed under the fiber maps. Our paper thus extends work by V. Kleptsyn and D. Volk who treated step skew products where the fiber maps map the interval strictly inside itself. We clarify the dynamics for an open and dense subset of such skew products. In particular we prove existence of a finite collection of disjoint attracting invariant graphs. These graphs are contained in disjoint areas in the phase space called trapping strips. Trapping strips are either disjoint from the end points of the interval (internal trapping strips) or they are bounded by an end point (border trapping strips). The attracting graphs in these different trapping strips have different properties.     

Chemical shielding properties for BN,BP, AlN,and AlP nanocones: DFT studies

The properties of boron nitride (BN), boron phosphide (BP), aluminum nitride (AlN), and aluminum phosphide (AlP) nanocones were investigated by density functional theory (DFT) calculations. The investigated structures were optimized and chemical shielding (CS) properties including isotropic and anisotropic CS parameters were calculated for the atoms of the optimized structures. The magnitudes of CS parameters were observed to be mainly dependent on the bond lengths of considered atoms. The results indicated that the atoms could be divided into atomic layers due to the similarities of their CS properties for the atoms of each layer. The trend means that the atoms of each layer detect almost similar electronic environments. Moreover, the atoms at the apex and mouth of nanocones exhibit different properties with respect to the other atomic layers.     

Fe3O4@Propylsilane@Histidine[HSO4‐] magnetic nanocatalysts: Synthesis,characterization and catalytic application for highly efficient synthesis of xanthene derivatives

The surface of Fe₃O₄ magnetic nanoparticles (MNPs) was modified by chloropropylsilane and histidine. The imidazole group of prepared Fe₃O₄@Propylsilane@Histidine MNPs converted to imidazolium hydrogen sulfate group and Fe₃O₄@Propylsilane@Histidine [HSO₄^‐] as a novel environmentally friendly ionic liquid/ magnetite nanoparticle was prepared, successfully. FT‐IR, XRD, SEM and TEM instruments was used to identifiy the histidine ionic liquids/magnetite nanoparticles (HILMNPs). The catalytic activity of synthesized HILMNPs was appraised for the synthesis of 9‐aryl‐1,8‐dioxooctahydroxanthene and spiro[indoline‐3,9′‐xanthene]trione derivatives. The activity of HILMNPs was much better than the other reported heterogeneous and homogeneous catalysts. Furthermore, the prepared catalyst could be separated from the reaction mixture and reused four times without any significant loss in its activity.