Skew Killing spinors in four dimensions

Annals of Global Analysis and Geometry - This paper is devoted to the classification of 4-dimensional Riemannian spin manifolds carrying skew Killing spinors. A skew Killing spinor $$\psi $$ is a...     

Biological Activities Evaluation of Enantiopure Isoxazolidine Derivatives: In Vitro,In Vivo and In Silico Studies

Applied Biochemistry and Biotechnology - A series of enantiopure isoxazolidines (3a–c) were synthesized by 1,3-dipolar cycloaddition between a (−)-menthone-derived nitrone and various...     

Electrodeposition of Ag nanoparticles on graphenized pencil lead electrode as a sensitive and low-cost sensor for iodate determination

In this study, a simple, sensitive and low-cost iodate electrochemical sensor based on graphenized pencil lead electrode (GPLE) modified with Ag nanoparticles (AgNPs) was presented. The GPLE was simply prepared via electrochemical exfoliation of pencil lead electrode (PLE) by applying an optimized potential in acidic media. Afterward, silver nanoparticles were electrochemically deposited on the surface of GPLE using chronoamperometry technique. The fabricated electrode was carefully characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques. Electrochemical behavior and also the electrocatalytic performance of the modified electrode toward the reduction of iodate were studied in details using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The fabricated sensor responds efficiently to iodate over the concentration range of 0.05 to 75 mM with a detection limit of 0.017 mM and sensitivity of 0.26 µA µM^?1 cm^?2. Remarkably enhanced electrocatalytic performance of the modified electrode was ascribed to the synergistic effect of graphene-like nanostructures with high surface to volume ratio, excellent conductivity and also the excessive electrocatalytic behavior of silver nanoparticles. The modified electrode was successfully employed for the determination of iodate in table and sea salt samples.     

Substrate assisted electrochemical deposition of patterned cobalt thin films

The patterned Co layers deposited on the scratched Cu surfaces were investigated with the use of the scanning electron microscopy. Patterned cobalt thin films were electrochemically deposited from the cobalt sulfate bath at room temperature. Pattering of cobalt was carried out by simple means of substrate scratching. Gentle scratching induces a direct pattering of cobalt from vertical to horizontal. The prepared pattered films were characterized for their structural, surface morphological and compositional properties by means of X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. X-ray diffraction studies reveal that the films are of cobalt. From the SEM images fabrication of patterns of cobalt is apparent. This work demonstrates a novel approach for obtaining patterned cobalt for many technological applications.     

On a parabolic problem with nonlinear term in a half space and global behavior of solutions

We take up the existence and global behavior of positive continuous solutions of the following nonlinear parabolic equation in (n?2) with boundary conditions u=0 on and u(x,0)=u₀(x). The nonlinear term is required to satisfy some conditions related to a functional class , which we introduce in this paper and will be called parabolic Kato class in the half space. Our approach is based on potential theory.     

Study of the parameters in electrical discharge machining through response surface methodology approach

Whereas the efficiency of traditional cutting processes is limited by the mechanical properties of the processed material and the complexity of the workpiece geometry, electrical discharge machining (EDM) being a thermal erosion process, is subject to no such constraints. The lack of correlations between the cutting rate, the surface finish and the physical material parameters of this process made it difficult to use. This paper highlights the development of a comprehensive mathematical model for correlating the interactive and higher order influences of various electrical discharge machining parameters through response surface methodology (RSM), utilizing relevant experimental data as obtained through experimentation. The adequacy of the above the proposed models have been tested through the analysis of variance (ANOVA). Optimal combination of these parameters was obtained for achieving controlled EDM of the workpieces.     

Asymptotic Formulas for Thermography Based Recovery of Anomalies

We start from a realistic half space model for thermal imaging, which we then use to develop a mathematical asymptotic analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design nonit-erative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.AMS subject classifications: 35R20, 35B30     

A Mathematical Programming Based Procedure for Breast Cancer Classification

In this paper we propose a new procedure for classification based on a hybrid approach. The classification problem is solved by minimizing the distance between the components of each clusters and the centers of the clusters. The determination of the cluster centers is therefore a critical step in our approach and was addressed used the k-means algorithm. Once the centers of each class are determined, the rule of center neighbourhood is applied to assign an element to a class using mathematical programming. The implementation of our hybrid approach was validated on benchmark datasets and applied to an original biological dataset on 84 breast cancer tumours. Each tumour was measured for five parameters corresponding to the expression of five biomarkers (proteins). The obtained classification was discussed using biological knowledge and classical clinical experts’ classification of breast tumors.     

2-Aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent

In this article, we have introduced application of 2-aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent. By using 2-aminophenyl diphenylphosphinite as a ligand and Pd(OAc)₂ as the pre-catalyst, structurally different aryl halides (I, Br, Cl) were reacted efficiently with phenylboronic acid in water to produce their corresponding biphenyl products in good to excellent yields under heterogeneous conditions. The catalyst is recyclable and was recycled for seven runs for the reaction of bromobenzene with phenylboronic acid without appreciable loss of its catalytic activity.