The correlation between learning styles and self–directed learning of fifth graders

Vietnam education has been directed into a learner-centered approach and fostering competencies for students, especially self-directed learning. Thus, understanding how students’ learning styles impact self-directed learning are crucial for the new direction of Vietnam education. This research employed the survey method by questionnaire and presents the results of practical research on the correlation between styles of learning and self–directed learning of fifth-grade students at elementary schools in District 10, Ho Chi Minh City, Vietnam. The sample was 364 fifth graders voluntarily participating in the survey with the consent of parents. The results indicated that learning styles are strongly correlated with self–directed learning competency of fifth graders. The data revealed that students at District 10 not only attained high self-directed learning levels but also their learning styles attributing impactfully on their self-directed learning competency

Taxonomy of the genus Paris L. (Melanthiaceae) in Vietnam

Paris L. is a small genus distributed widely in Eurasia. In Vietnam Paris occur in evergreen broad-leaved forests in some mountainous areas of the North and the Central highlands. Due to over-exploitation as well as habitat loss, populations of some Paris species are seriously declining. This genus has not been studied extensively in Vietnam. The aim of this study was to define the morphological characteristics of the genus Paris in Vietnam. Morphological description, dichotomous key for identification, ecology and distributions of the genus in Vietnam are reported. The results show that this genus in Vietnam comprises 8 species and 2 varieties, possesing unilocular ovary with parietal placenta

IMPROVING PUBLIC SPEAKING SKILLS FOR UNIVERSITY STUDENTS: CHALLENGES AND SOLUTIONS

This study explores English as a foreign language students’ challenges and investigates solutions for students to improve their public speaking skills at a university campus in the South of Vietnam. A descriptive mixed-method approach is used in this investigation allowing data to be quantitatively and qualitatively collected through questionnaires and interviews. The findings showed that English as a foreign language students faced several problems in public speaking as well as a lack of confidence. Many methods to improve public speaking skills were found, including making presentations, creating video blogs, and implementing circumlocution, methods that helped students increase their confidence in speaking and using effective body language. The findings of this study can be applied to help students overcome their challenges with public speaking

Lecane (Rotifera: Lecanidae) community in psammon habitat in Central Coast Vietnam: Diversity and relation to environmental condition

Characteristics of the Lecane (Rotifera) community in psammon in Central Coast Vietnam were investigated. A total of 50 taxa were identified in samples collected at hygropsammon zones of temporary pools, contributing 4 new species to rotifers' record of Vietnam. Psammonxenic species accounted for the largest percentage of Lecane community with 82%, followed by psammophiles (12%) and psammonbionts (6%). Influences of some environmental factors on the distribution of psammic lecanids were also observed. This group of organisms showed a slight tendency towards sand with grain sizes larger than 125 µm. Besides, other abiotic factors including pH, total phosphorus (TP) and total dissolved solids (TDS) were also found to significantly related to the distribution of some common Lecane species

An Assessment of Cough Medicine Dispensing Practice to Children Under Two Years Old in Pharmacies in Ho Chi Minh City Using Simulated-Patient Method

Over-the-counter (OTC) cough and cold medications (CCMs) have been used to treat the symptoms of upper respiratory infection in children for decades. The safety of CCMs in children has been questioned. The data on knowledge of pharmacists in supplying cough medicines for children under two years have been limited. This study aimed to evaluate the pharmacists’ dispensing decisions to manage the cough in children under two years old. A descriptive cross-sectional was carried out in 300 pharmacies in 15 districts in Ho Chi Minh City, Vietnam. The pharmacists were interviewed by a simulated patient. The results showed that, information that pharmacists actively asked the client about the patient and disease symptoms was limited. Most pharmacists did not provide adequate instructions and counsel about using drugs for clients. Only 22/300 (7.33%) of pharmacists appropriately provided cough medicines for children under 2 years old. The main reason of inappropriateness was the deficiency of knowledge about updated contraindication of N-acetylcysteine (93.17%). Pharmacists in pharmacies located in districts 3, 11 and Binh Thanh had higher rate of rational provision than those in other districts. A good and full understanding of the patient symptom helped the pharmacists supply cough medicines more reasonably. The limited caution of pharmacists and the low proportion of pharmacists updating contraindication of N-acetylcysteine should be considered as a warning sign in pharmacy practice in Ho Chi Minh City, Vietnam

Jointly power allocation and phase shift optimization for RIS empowered downlink cellular networks

Reconfigurable Intelligent Surfaces (RIS) have been highlighted by the research community as a key enabling technology for the enhancement of next-generation wireless network performance, including energy efficiency, spectral efficiency, and network throughput. This paper investigates how RIS-assisted communication can effectively maximize the downlink throughput of a cellular network. Specifically, the paper considers a communication scenario where a single base station serves multiple ground users with the aid of an RIS placed on a building facade. For such a communication scenario, we considered an optimization problem aimed at maximizing the overall downlink throughput by jointly optimizing power allocation at the base station and phase shift of RIS reflecting elements, subject to power consumption and quality-of-service constraints. To address its non-convex nature, the original optimization problem has been divided into two subproblems. The first one, for power control with fixed phase shift values, is a convex problem that can be easily solved. Subsequently, a phase shift searching procedure to solve the non-convex problem of RIS phase shift optimization has been adopted. The results from numerical simulations show that the proposed method outperforms other conventional methods proposed in the literature. In addition, computational complexity analysis has been conducted to prove the low complexity of the proposed method

Modulation and application of chitosal to adsorb lead (Pb2+) in waterwaste

One of methods to eliminate metals from water is the use of adsorption. Chitosal is a material with a biological origin and was chosen for this study. The material was extracted from shrimp shells. The final product of the extraction progress was chitosal gel with a diameter of 3.5 mm, 97% of purity and good solubility in 1% CH3COOH solution. Three adsorption columns were built with PVC plastic. Two experiments at lead concentration 6.98 mg/l and 15.7 mg/l were carried out with the flow from the top down, at different water retention times of 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, and 120 minutes. The results showed that at lead concentrations of 6.98 mg/l we did not find the optimum water retention time. However, in the second experiment with lead concentration of 15.7 mg/l we determined the optimal water retention time was 60 minutes for column h1 and the lead adsorption efficiency achieved was 30.44%; column h2, h3 were the same time (90 minutes) and the lead adsorption efficiency reached 44.71%; and 52.87% respectively

Universality in odd-even harmonic generation and application in terahertz waveform sampling

Odd-even harmonics emitted from a laser-target system imprint rich, subtle information characterizing the system's dynamical asymmetry, which is desirable to decipher. In this Letter, we discover a simple universal relation between the odd-even harmonics and the asymmetry of the THz-assisted laser-atomic system -- atoms in a fundamental mid-IR laser pulse combined with a THz laser. First, we demonstrate numerically and then analytically formulize the harmonic even-to-odd ratio as a function of the THz electric field, the source of the system's asymmetry. Notably, we suggest a scaling that makes the obtained rule universal, independent of the parameters of both the fundamental pulse and atomic target. This universality facilitates us to propose a general pump-probe scheme for THz waveform sampling from the even-to-odd ratio, measurable within a conventional compact setup

High rate nitrogen removal by ANAMMOX internal circulation reactor (IC) for old landfill leachate treatment

© 2017 Elsevier Ltd This study aimed to evaluate the performance of a high rate nitrogen removal lab-scale ANAMMOX reactor, namely Internal Circulation (IC) reactor, for old landfill leachate treatment. The reactor was operated with pre-treated leachate from a pilot Partial Nitritation Reactor (PNR) using a high nitrogen loading rate ranging from 2 to 10 kg N m−3 d−1. High rate removal of nitrogen (9.52 ± 1.11 kg N m−3 d−1) was observed at an influent nitrogen concentration of 1500 mg N L−1. The specific ANAMMOX activity was found to be 0.598 ± 0.026 gN2-N gVSS−1 d−1. Analysis of ANAMMOX granules suggested that 0.5–1.0 mm size granular sludge was the dominant group. The results of DNA analysis revealed that Candidatus Kueneniastuttgartiensis was the dominant species (37.45%) in the IC reactor, whereas other species like uncultured Bacteroidetes bacterium only constituted 5.37% in the system, but they were still responsible for removing recalcitrant organic matter