INFLUENCE OF SINTERING TEMPERATURE ON PHASE FORMATION AND OPTICAL PROPERTIES OF LEAD-FREE FERROELECTRIC BI0.5NA0.5TIO3 MATERIALS

Pb(Zr,Ti)O3 based ferroelectric materials have been widely used in electronic devices even though they were banned due to the toxicity of lead on health and environment. Among the lead-free ferromagnetic materials, Bi0.5Na0.5TiO3 has received much attention because their ferroelectric and piezoelectric characteristics are comparable to Pb(Zr,Ti)O3. In this report, Bi0.5Na0.5TiO3 was fabricated by sol-gel method. The influence of fabricating conditions such as gelization, sintering temperature on crystallinity was studied. The result showed that Bi0.5Na0.5TiO3 was in single phase when compenstation amount of Na in gelization is 40 mol%; sintering temperature higher than 800 oC and sintering time is 2 h. The bandgap of Bi0.5Na0.5TiO3 which estimated from absorption spectroscopy is in the range of 3.01 - 3.18 eV

TEACHERS’ CORRECTIVE FEEDBACK ON ENGLISH STUDENTS’ WRITING

This investigates the participants’ attitudes towards corrective feedback as well as the types of corrective feedback on learners’ performance by questionnaires for both students and teachers. Fifty–eight 2nd-year students and 5 teachers of English at a university in the Mekong Delta of Vietnam participated in the study. The results indicated that students had a positive attitude towards teachers’ corrective feedback. Besides, with the analyzed data, correction with comments and teacher correction was considered as the most useful strategy when giving feedback in the learners’ performance. The outcomes of the study suggest a widespread employment of corrective feedback in teaching writing at universities and colleges in the region.   Article visualizations

Empirical Investigation of Omni-channel Customer Behavior: Multiple Mediation Effects of Website and Mobile Interactivity

While existing retail research has focused on retail channels in isolation from a single or multi-channel retailing perspective, there is a need to investigate shopping behavioral intention from an omni-channel and customer-centric retailing perspective. The main of this study is to analyze the customer omni-channel behavior under multiple mediating effects of website and mobile interactivity. Data collected from valid 287 respondents via both online and paper form. Partial least squares structural equation modeling (PLS-SEM) and Smart-PLS software have been used to test proposed hypotheses. The result underlined the significant positive effects of technology literacy, attitude towards website interactivity and attitude towards mobile device interactivity on customer’s behavioral intention. Moreover, website interactivity and augmented reality have highest impact attitude towards website interactivity and attitude towards mobile device interactivity respectively

Characterization of O-glycan binding lectin from the red alga Hydropuntia eucheumatoides

The red alga, Hydropuntia eucheumatoides is one of the algal genera from which agar is commercially extracted, and is the main source of agar in the world. The lectin HEL from the red alga H. eucheumatoides was isolated by a combination of aqueous ethanol extraction, ethanol precipitation, ion exchange and filtration chromatography. Lectin gave a single band with molecular mass of 17,000 Da in both non-reducing and reducing SDS-PAGE conditions, therefore lectin exists in monomeric form. The hemagglutination activities of HEL were stable over a wide range of pH from 3 to 10, temperature up 60 oC and not affected by either the presence of EDTA or addition of divalent cations, indicating that lectin requires no metal for biological activity. The hemagglutination activities of HEL were not inhibited by monosaccharides and glycoproteins, D-glucose, D-mannose, D-galactose, D-xylose, N-acety-D-mannosamine, transferin, fetuin and yeast mannan, but strongly inhibited by monosaccharides containing  acetamido groups at equatorial C2 position, such as N-acetyl-galactosamine, N-acetyl-glucosamine, N-acetyl-neuraminic acid and glycoprotein porcine stomach mucin bearing O-glycans. Thus, lectin is specific for O-glycans and  may recognize the sequences GalNAcαSer/Thr, GalNAc(α1-3)[Fuc(α1-2)]Gal(β1-4)GlcNAc(β1-3)GalNAc- and GluNAc(α1-4)Gal- under interacting with the acetamido groups at equatorial C2 position of the terminal sugar residues in oligosaccharide structures of O-glycans. The red alga H. eucheumatoides could promise to be a source of valuable lectins for application in biochemistry and biomedicine

Biosynthesis of silver nanoparticles using curcumin against the bovine mastitis bacteria

Bovine mastitis is the most common disease and has greatly affected economies around the world. This study aimed to determine the antibacterial ability of bovine mastitis by curcumin - silver nanoparticles (Cur-AgNPs). The study included experiments on presenting a new process for synthesizing silver nanoparticles using curcumin from fresh turmeric as a reducing agent and stabilizer. UV visible spectroscopy of the samples revealed the localized surface plasmon resonance absorbance of the dispersion of silver nanoparticles at 430 nm. The prepared Cur-AgNPs has a spherical shape with an average size of 30 nm and a size distribution of 15–47 nm. FT-IR (Fourier transform infrared spectroscopy) measurements of the samples showed that silver nanopartilces has been encapsulated well by curcumin. Cur-AgNPs with a concentration of 50-200 μg/mL has very effect to Staphylococcus aureus, Pseudomonas aeruginosa causing bovine mastitis in vitro. The maximum inhibition zone formed was 15 ± 0.85 mm for Staphylococcus aureus and 14 ± 0.56 mm for Pseudomonas aeruginosa. Plant materials mediating for the synthesis of silver nanoparticles have relatively rapid, less expensive, and widespread applications for antimicrobial therapy in the livestock sector

TỔNG HỢP VẬT LIỆU Ni/UiO-66 THEO PHƯƠNG PHÁP TRỰC TIẾP VÀ GIÁN TIẾP

An archetypal metal-organic framework, UiO-6,6, synthesized with the solvo-thermal method, has a large specific surface area of 1071 m2·g–1. This material was modified with NiCl2 in the direct (Nix(tt)/UiO-66) and indirect (Nix(gt)/UiO-66) methods. The two modified materials were characterized by using powder X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. Their crystalline and chemical structure is not much different. However, the thermal and porous properties differ from each other.UiO-66 là họ vật liệu khung hữu cơ kim loại tổng hợp bằng phương pháp nhiệt dung môi có diện tích bề mặt riêng lớn (1071 m2·g–1). Vật liệu UiO-66 này được biến tính bằng NiCl2 theo phương pháp trực tiếp (Nix(tt)/UiO-66) và gián tiếp (Niy(gt)/UiO-66). Kết quả đặc trưng hai vật liệu biến tính này bằng nhiễu xạ tia X, hiển vi điện tử quét và phổ hồng ngoại khác nhau không đáng kể. Tuy nhiên, phân tích nhiệt trọng lượng và đẳng nhiệt hấp phụ – khử hấp phụ N2 cho thấy có sự khác nhau giữa các phương pháp tổng hợp

RMDM: A Multilabel Fakenews Dataset for Vietnamese Evidence Verification

In this study, we present a novel and challenging multilabel Vietnamese dataset (RMDM) designed to assess the performance of large language models (LLMs), in verifying electronic information related to legal contexts, focusing on fake news as potential input for electronic evidence. The RMDM dataset comprises four labels: real, mis, dis, and mal, representing real information, misinformation, disinformation, and mal-information, respectively. By including these diverse labels, RMDM captures the complexities of differing fake news categories and offers insights into the abilities of different language models to handle various types of information that could be part of electronic evidence. The dataset consists of a total of 1,556 samples, with 389 samples for each label. Preliminary tests on the dataset using GPT-based and BERT-based models reveal variations in the models' performance across different labels, indicating that the dataset effectively challenges the ability of various language models to verify the authenticity of such information. Our findings suggest that verifying electronic information related to legal contexts, including fake news, remains a difficult problem for language models, warranting further attention from the research community to advance toward more reliable AI models for potential legal applications.Comment: ISAILD@KSE 202

Antibacterial Nanocomposites Based on Fe 3

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions