P-AMENABLE LOCALLY COMPACT HYPERGROUPS

Abstract. Let K be a locally compact hypergroup with left Haar measure and let We say that K is P-amenable if there exists a left invariant mean on C(P 1 (K)), the space of all bounded continuous functions on P 1 (K). In this note, we consider the Pamenability of hypergroups. The P-amenability of hypergroup joins K = H ∨ J where H is a compact hypergroup and J is a discrete hypergroup with H ∩ J = {e} is characterized. It is also shown that Z-hypergroups are P-amenable if Z(K) ∩ G(K) is compact

Electrode Materials for Lithium Ion Batteries: A Review

Electrochemical energy storage systems are categorized into different types, according to their mechanisms, including capacitors, supercapacitors, batteries and fuel cells. All battery systems include some main components: anode, cathode, an aqueous/non-aqueous electrolyte and a membrane that separates anode and cathode while being permeable to ions. Being one of the key parts of any new electronic device or electric vehicles, lithium ion batteries have gained great attention in recent years. Lithium ion batteries store/provide energy by insertion/extraction of lithium ions in/from the structure of the electrode materials in successive charge/discharge cycles. The energy and power densities, determine the batteries performance. In order to improve the energy/power density and cyclic life of a lithium ion battery, its electrode materials and electrolyte must be properly chosen. Cathode materials store energy through intercalation or conversion reactions, while the energy storage mechanism in anode materials are intercalation, conversion reactions or alloying/dealloying. Depending on the electrode material, one or more of the aforementioned mechanisms may take place which directly affect the battery performance. Each group of electrode materials have their own advantages and shortcomings; therefore, proper selection of the electrode material is an important issue in applicability of a lithium ion battery. This review covers the principles of energy storage in lithium ion batteries, anode and cathode materials and the related mechanisms, recent advancements and finally the challenges associated with enhancement of lithium ion batteries

An Iranian Case Study on the Relationship between EFL Teachers' Self-confidence Level and Learners' Speaking Development

Abstract Self-confidence of English language teachers has been discovered to be a significant factor in learners' achievement. This study aimed to find the relationship between English teachers' self-confidence level and second language (L2) learners' development of conversational skills. The participants of this study were 60 Higher Intermediate L2 learners at Shayan Language Institute in Torbat Heydarie, Iran. A self-confidence questionnaire was used for the present article. The teachers of Shayan institute were asked to answer this questionnaire. Then, two male teachers, one with high self-confidence and one with normal level of self-confidence were selected as the teachers of experimental and control groups, respectively. The course lasted for 12 sessions (6 weeks with two weekly sessions); in each session both teachers provided their students with the same techniques, including conversations, role plays, speaking about pictures, etc. To homogenize the students a conversation-based proficiency test (CPE speaking test) was administered. Afterwards, 30 second language learners were selected and divided into the experimental and control groups. At the end of the course a posttest was administered. The results of t test analysis indicated that participants in the self-confident group could significantly outperform those in the control group. The results of this study can provide pedagogical implications for English teachers to be self-confident and can convey this quality of L2 learners in the class