Stable Reconstruction of Anisotropic Objects from Near-Field Electromagnetic Data

This paper addresses the electromagnetic inverse scattering problem of determining the location and shape of anisotropic objects from near-field data. We investigate both cases involving the Helmholtz equation and Maxwell's equations for this inverse problem. Our study focuses on developing efficient imaging functionals that enable a fast and stable recovery of the anisotropic object. The implementation of the imaging functionals is simple and avoids the need to solve an ill-posed problem. The resolution analysis of the imaging functionals is conducted using the Green representation formula. Furthermore, we establish stability estimates for these imaging functionals when noise is present in the data. To illustrate the effectiveness of the methods, we present numerical examples showcasing their performance.Comment: 22 page

TASK-BASED APPROACH: AN OVERVIEW

During recent years, the task-based approach has been considered an effective methodology for teaching English as a foreign language. The term “task-based” appear in most of the learning activities in the classroom. It is clear that English teachers are being more interested in the use of task-based approach for most of English skills. They are making efforts to make lessons become more interesting and meaningful. Besides, the task-based assessment has been paid much attention by English teachers. Therefore, this paper aims at presenting the background of task-based approach, giving definition of learning tasks, illustrating task-based framework and identifying the roles of teachers and learners in task-based approach. In addition, it describes the assessment of task-based approach and making recommendation for language teachers relating to how to conduct task-based lessons effectively.  Article visualizations

Study on methylene blue adsorption using cashew nut shell-based activated carbon

Adsorption is a widely used technique for the treatment of wastewater containing dyes, which are pollutants that can have serious impacts on the aquatic ecosystems. In this work, activated carbon (AC) was prepared from cashew nut shell (CNS) and used to adsorb methylene blue (MB) from solution. The CNS AC was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption isotherms. The adsorption behavior of MB on CNS AC was investigated by varying the initial solution pH, adsorbent dosage, and initial MB concentration. The results showed that the CNS AC was effective for MB removal, with an adsorption capacity of 24.8 mg/g. The adsorption nature of MB onto the CNS AC surface was explored by analyzing the experimental data using isotherm and kinetic models. The Freundlich and Dubinin-Radushkevich (D-R) isotherm models showed good agreement with the experimental adsorption equilibrium results. The mean adsorption energy was found to be 22.4 kJ/mol, indicating chemical adsorption. The adsorption of MB on the CNS AC followed pseudo-second-order kinetics. This study demonstrates the potential application of CNS AC for MB removal

THE WORK-OUTS TO OPTIMIZE THE EFFICIENCY FOOTWORK – A CASE STUDY FOR TALENTED FEMALE TABLE TENNIS ATHLETES AT THE AGE OF 14-15 IN VINH LONG PROVINCE, VIETNAM

The purpose of this study was to build up and evaluate the application of work-outs about the efficiency of footwork for talented female table tennis athletes. 08 healthy female talented table tennis athletes at the age of 14-15 in Vinh Long province were chosen to participate in the 8-week pre-season training. Results indicated that the 20 work-outs were selected to improve the efficiency footwork through the basis of training principle, participant’ characteristics, previous studies, and expert interviews. Besides, there were significant differences in all 06 tests to evaluate the footwork ability after the experiment. Moreover, the percentage of change indicated increased, from the objective perspective, we found that the growth rate was still at the moderate level (from 2.72% to 6.07%). Therefore, it is necessary to apply the 20 work-outs more flexibly and closely to improve the efficiency of footwork in different training phases next year. It was concluded that the application of the 20 work-outs about the efficiency of footwork had positive effects on female talented table tennis athletes. Future studies should be conducted on a group of males, diverse in training levels, and/or on the other sports group that need to promote footwork ability.   Article visualizations