The Role of Social Network Sites in English Language Teaching_Harnessing the Potential of Facebook and YouTube as Learning Tools

This paper provides a comprehensive review of the role of Social Network Sites (SNSs) in the context of English as a Second Language (ESL) and English as a Foreign Language (EFL) teaching and learning. It examines the definitions and potential applications of SNSs, with a specific focus on Facebook and YouTube. The paper discusses the educational and instructional implementations of these SNSs, as well as the challenges and drawbacks faced by both teachers and students when utilizing them. Furthermore, it explores the pedagogical implications of incorporating the cutting-edge features offered by SNSs, aiming to bridge the gap between traditional and technologically driven learning environment

Diterpenoids from Fokienia hodginsii.

In continuous research on the chemical constituents of the twigs and leaves of Fokienia hodginsii (Dunn) A. Henry et Thomas growing in Highland, Lam Dong province 4 diterpenoids, including 3-oxo-totarol (totarolone, 1), 3β-hydroxytotarol (2), 15-nor-labda-8(17),12E-diene-14-carboxaldehyde-19-oic acid (3) and 13-oxo-15,16-dinorlabda-8(17),11E-diene-19-oic acid (4) were isolated. Their structures were elucidated by the spectroscopic methods and comparison with reported data. This is the first report on the isolation of compounds 1, 2 and 3 from this plant. Keywords. Fokienia hodginsii; totarane; nor-labdane diterpenoid

Mangrove restoration in Vietnamese Mekong Delta during 2015-2020: Achievements and challenges

Mangrove forest in the Mekong Delta plays important roles in protecting coasts from soil erosion and strong waves, supplying seafood, and accumulating carbon. Despite these benefits, mangroves have been and continue to be severely damaged by the impacts of natural and socioeconomic activities. In recent years, large areas of mangrove forest have been restored through planting and other various management actions. In this study, we analyzed high-resolution WorldView-2 images to quantify changes in the mangrove forest in seven coastal provinces (Tien Giang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu, Ca Mau, and Kien Giang) of the Mekong Delta from 2015 to 2020. Our study is one of the first to analyze mangrove forest change at the commune scale, the smallest official administrative unit in Vietnam, to determine the area of restored mangroves. The potentials and challenges in future mangrove restoration were also assessed by analyzing satellite imagery and field survey data. In the study area, mangrove forest area increased by 11,184 ha (approximately 2,237 ha per year) from 79,593 ha in 2015 to 90,777 ha in 2020. A total area of 16,138 ha (approximately 20.3%) was lost due to mangrove conversion to other land uses, aquaculture activities and coastal erosion, etc., while 27,322 ha (approximately 34.1%) was restored or newly planted during state- and NGO-funded mangrove restoration projects and programs. These results confirmed that mangrove restoration projects and programs have played a significant role in maintaining and increasing mangrove forest cover in Mekong Delta. The results can also assist managers and decision makers in mangrove restoration evaluation, and suggest analyzing WorldView-2 images to monitor mangrove restoration over time in Vietnam

Terpenoids from Dacrycarpus imbricatus.

The phytochemical investigation of the hexane extract from the twigs and leaves of Dacrycarpus imbricatus (Blume) de Laub led to the isolation of a rare sesquiterpene, spathulenol (1) along with three diterpenes named pimaric acid (2), trans-communic acid (3) and cis-communic acid (4). Their structures were determined by combination of spectral analysis and comparison with reported data. This is the first report on isolation of compound 1 from the Podocarpaceae family. Keywords. Dacrycarpus imbricatus, spathulenol, pimaric acid, communic acid

CIGOS 2021, Emerging Technologies and Applications for Green Infrastructure

International audienc

Oxidation of carbon nanotubes using for Cu(II) adsorption from aqueous solution

Carbon nanotubes (CNTs) synthesized by chemical vapour deposition without using hydrogen were oxidized with 0.1 M potassium permanganate at 40oC for 2 hours and exhibited high CuII adsorption capacity from aqueous solution. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM) and nitrogen adsorption/desorption isotherms were used to characterize the oxidized CNTs. After oxidizing, the obtained CNTs were used to remove CuII from aqueous solution. With CuII initial concentration of 20 mg.L-1, at pH of 4 and adsorbent dosage of 0.2 g.L-1, the oxidized CNTs exhibited high CuII adsorption ability with maximum adsorption capacity of 174.4 mg.g-1

Patterns and Strength of Pollen Tube Arrest in Self–incompatible Citrus Accessions (Rutaceae)

Pollen tube growth was examined to demonstrate the degree of self–incompatibility reaction in the pistils of 121 Citrus accessions including 77 pummelo accessions. One hundred of the 121 accessions were determined to be self–incompatible with the aid of an epifluorescent microscope. Based on the difference of self pollen tube growth between the self–incompatible and self–compatible accessions, the degree of self– incompatibility reaction in four portions of the pistils was roughly divided into three categories, i.e., high (H), moderate (M) and low (L). The degrees of the reaction in the stigmas, upper styles, middle styles and basal styles of these accessions were high–high–high–high (H–H–H–H), moderate–high–high–high (M–H– H–H), moderate–moderate–high–high (M–M–H–H), low–high–high–high (L–H–H–H), low–moderate–high– high (L–M–H–H) or low–low–high–high (L–L–H–H) in order from the stigma to lower style, and were designated as H, MH, MMH, LH, LMH and LLH types respectively. All of 77 pummelo accessions examined were self–incompatible and all of the seven types of self–incompatibility reaction were observed in the accessions of which about 80% showed either H or MH type of reaction. The degree of self–incompatibility reaction was more variable in the pummelo accessions originating in Southeast Asia than those in Japan. In three mandarin relatives and four yuzu relatives, the H and MH types of self–incompatibility reaction were exclusively found. These results suggested that the degree of self–incompatibility reaction in each part of style was different in different Citrus accessions and showed geographical diversity. The reason for this is discussed

NURBS-based finite element analysis of functionally graded plates: Static bending, vibration, buckling and flutter

In this paper, a non-uniform rational B-spline based iso-geometric finite element method is used to study the static and dynamic characteristics of functionally graded material (FGM) plates. The material properties are assumed to be graded only in the thickness direction and the effective properties are computed either using the rule of mixtures or by Mori-Tanaka homogenization scheme. The plate kinematics is based on the first order shear deformation plate theory (FSDT). The shear correction factors are evaluated employing the energy equivalence principle and a simple modification to the shear correction factor is presented to alleviate shear locking. Static bending, mechanical and thermal buckling, linear free flexural vibration and supersonic flutter analysis of FGM plates are numerically studied. The accuracy of the present formulation is validated against available three-dimensional solutions. A detailed numerical study is carried out to examine the influence of the gradient index, the plate aspect ratio and the plate thickness on the global response of functionally graded material plates. © 2012 Elsevier Ltd