Mathematical aspects of catalyst positioning in Lithium/Air Batteries

Lithium/air batteries has been taken interest by many scientists over the last years. The catalyst positioning problem describing the porous cathode during the discharge process is concerned in the research of optimizing the capacity of Lithium/air batteries. During discharge process, there is a critical issue: the discharge oxygen reduction products is insoluble in the organic electrolytes. This clogs the oxygen entrance to the pore to be reacted with Lithium ions and limits the capacity of the batteries by narrowing the active surface inside the pore. The dynamics of the discharge process is described by the initial mixed boundary value problem for two one-dimensional partial differentiable equations. The two variables of the system are the pore radius inside the cathode and the Oxygen concentration at certain coordinate and time. The subject of the thesis is to investigate some catalyst positioning models and to maximize the free volume of the pore after pore clogging by the deposited discharged products. We aim at the following fields: First, we research analytically the forward model describing continuous catalyst positioning in Li/air batteries: well-posedness of the problems, the Fr echet differentiability of the pore radius and the oxygen concentration with respect to catalytic function in some spaces. Second, we present optimization problems and analyze the sensitivity and adjoint method to solve them. Finally, some numerical methods are carried out to solve the forward problems and some numerical approach for solving optimization problem are also examined to illustrate the theoretical results

AUTHENTIC ASSESSMENT: A REAL LIFE APPROACH TO WRITING SKILL DEVELOPMENT

 Since assessment is an indispensable part of education, curriculum makers, educators and teachers have engaged in an ongoing discussion of how to address student performance. A variety of assessments including both short-term and long-term ones can be applied during or at the end of the learning process. Among such types, authentic assessment is a prominent approach. This paper is going to advocate authentic assessments as it fosters students' growth and teachers' pedagogical strategies. In addition, it helps to reach the goals of educational practices through the authenticity of equity and innovation when students actively seek their own ways to appreciate what they have learnt. Particularly, in a writing skills class, learners can take this opportunity to improve step by step their own proficiency in the use of written words. The paper, hence, discusses how authentic assessment can be applied to develop college students' writing through classroom observation and a set of semi-structured interviews. The result of the study revealed that using authentic assessment is an effective strategy for enhancing students’ interest in writing process and writing task fulfillment. Students would find it easier to become skillful writers at their English levels. The study, therefore, recommends more uses of authentic assessment in teaching writing skills as well as in teaching and learning the English language in general

3-Point++: a new Technique for 3D Manipulation of Virtual Objects

International audienceManipulation in immersive Virtual Environments (VEs) is often difficult and inaccurate because humans have difficulty in performing precise positioning tasks or in keeping the hand motionless in a particular position without any help of external devices or haptic feedback. To address this problem, we propose a set of four manipulation points attached to objects (called a 3-Point++ tool, including three handle points and their barycenter), by which users can control and adjust the position of objects precisely. By determining the relative position between the 3-Point++ tool and the objects, and by defining different states of each manipulation point (called locked/unlocked or inactive/active), these points can be freely configured to be adaptable and flexible to enable users to manipulate objects of varying sizes in many kinds of positioning scenarios

Guiding Techniques for Collaborative Exploration in Multi-Scale Shared Virtual Environments

International audienceExploration of large-scale 3D Virtual Environments (VEs) is difficult because of lack of familiarity with complex virtual worlds, lack of spatial information that can be offered to users and lack of sensory (visual, auditory, locomotive) details compared to exploration of real environments. To address this problem, we present a set of metaphors for assisting users in collaborative navigation to perform common exploration tasks in shared collaborative virtual environments. Our propositions consist in three guiding techniques in the form of navigation aids to enable one or several users (called helping user(s)) to help one main user (called exploring user) to explore the VE efficiently. These three techniques consist in drawing directional arrows, lighting up path to follow, and orienting a compass to show a direction to the exploring user. All the three techniques are generic so they can be used for any kind of 3D VE, and they do not affect the main structure of the VE so its integrity is guaranteed. To compare the efficiency of these three guiding techniques, we have conducted an experimental study of a collaborative task whose aim was to find hidden target objects in a complex and multi-scale shared 3D VE. Our results show that although the directional arrows and compass surpassed the light source for the navigation task, these three techniques are completely appropriate for guiding a user in 3D complex VEs

CURRENT CULTURAL LIFESTYLE OF THE HMONG PEOPLE IN THE BORDER AREA OF CAO BANG PROVINCE, VIETNAM

The culture of ethnic minorities in general and the Hmong people in particular are an essential part of Vietnam's advanced culture, rich in ethnic characteristics. In the current process of international integration, the exchange and adaptation of cultural values from the outside world are both an objective necessity and a challenge. This process provides opportunities while, at the same time, posing challenges for preserving and promoting traditional cultural values. Additionally, the Hmong culture is also influenced by religious beliefs, specifically Protestantism, which accentuates cultural transformation. This has an impact on the stability and development of the cultural and social aspects, as well as the local and national security. Therefore, this article focuses on analyzing the current cultural lifestyle of the Hmong people in the border region of Cao Bang province. It aims to identify the issues that arise and propose solutions to preserve and promote the cultural values of this ethnic group under the influence of Protestantism. Simultaneously, it seeks to limit the emergence of negative factors contributing to the sustainable development of the border region of Cao Bang province

THE IMPACT OF INNOVATION ON ECONOMIC GROWTH: THE SPILLOVER EFFECT OF FOREIGN DIRECT INVESTMENT

Purpose of the study: Innovation is seen as the key to improving quality and productivity, thereby promoting competition and economic growth. This study analyzes the impact of innovation on economic growth through various measures, such as research and development spending, the number of researchers, number of patents as well as trademark registrations. Research results are evidence to recommend policies for intellectual-based economic growth. Methodology: Literature review and empirical analysis conducted in the study. The empirical method is a two-step System Generalize Methods of Moments (GMM), aiming at reliable results. Accessing the World Bank Database, research data from 64 developed and developing countries are collected from 2006 to 2014. Main Findings: The empirical findings show that innovation plays a crucial contribution in promoting economic growth, similar to national openness and government spending on education. This study also finds a positive impact on foreign investment flows and their spillover role in enhancing the correlation between innovation and economic growth. Applications of this study: The findings of this study focus on the contributions of innovation, foreign direct investment inflows, and other macro factors that can be enforced to improve economic growth by policymakers. Novelty/Originality of this study: The study uses different measures of innovation, including inputs such as the number of researchers, research and development expenditure, and outputs as the number of patents and number of trademark registrations. Empirical findings are found consistently, thus confirming that innovation is very important for economic growth. The study also shows convincing evidence confirming the positive contribution of foreign direct investment as well as its spillover effect on innovation and economic growth

Examining the effects of lead on the life of larval zebrafish (1-7 days old)

Lead (Pb) is a toxic metal and and can cause variety of disorders and effect on neu-ronal function and neurodevelopment. Using zebrafish as a model, the aim of this study was to evaluate the effects of concentrations of Pb2+ on the life of zebrafish larvae (from 1 to 7 days old)yesBelgorod State Universit

Complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus) of Vietnam

The complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus, Dong Tao) was obtained by PCR and sequencing. The complete mitogenome was 16,783 bp in length, with the nucleotide composition for A, T, C, G was 30.29%, 23.75%, 32.48%, and 13.48%, respectively. The mitogenome of Dong Tao chicken contained a non-coding control region (D-loop), 2 rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis revealed that breed Dong Tao chicken breed was sister-close to G. gallus breed Guangxi, and paraphyletic to G. spadiceus, S. jabouillei, and a range of Chinese indigenous, ie. breeds Rugao and Taoyuan

Serum Granulysin in Differentiation of Stevens-Johnson Syndrome/toxic Epidermal Necrolysis and Erythema Multiforme

BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute, life-threatening drug reactions, which lead to massive epidermal necrolysis. Granulysin plays an important role as a key mediator for keratinocyte apoptosis in these conditions. Erythema multiforme (EM) may have skin manifestation similar to SJS/TEN. AIMS: The aim of the study was to compare serum granulysin levels in patients with SJS/TEN and EM as well as to investigate a possible association between serum granulysin levels and the severity of SJS/TEN. METHODS: In total, 48 patients with SJS/TEN, 43 patients with EM, and 20 health controls (HCs) were enrolled. We measured serum granulysin levels using enzyme-linked immunosorbent assay. RESULTS: The average level of serum granulysin in the SJS/TEN patients was 23.0 ng/ml (range 1.2–144.6 ng/ml), significantly higher than that of EM group (20.1 ng/ml; range 8.5–121 ng/ml, p < 0.05) and HCs group (20.8 ng/ml; range 10.1–46.7 ng/ml, p < 0.05). Of 48 SJS/TEN patients, the 25 samples collected <6 days after onset showed higher level of serum granulysin (27.7 ng/ml; range 2.5–144.6 ng/ml) than those collected ≥6 days after onset (17.9 ng/ml; range 1.2–59 ng/ml; p > 0.05). No significant correlation was found between serum granulysin levels and the body surface area affected and the modified-SCORTEN. At the day of re-epithelialization, serum granulysin levels were not different compared with those at the day of hospitalization. CONCLUSIONS: Serum granulysin levels are significantly higher in SJS/TEN group than in EM group. After the onset, serum granulysin levels in patients with SJS/TEN are not a good biomarker to evaluate the severity of the diseases