Pyrolysis and propensity to self Ignition of long-term low- temperature wood chars

Master'sMASTER OF SCIENCE (BUILDING

CONCEPTS AND AWARENESS ABOUT SELF-HARM AND SUICIDAL THOUGHTS AMONG HIGH SCHOOL STUDENTS CURRENTLY

The article focuses on understanding concepts and awareness of suicidal thoughts and self – harm behaviors based on quantitative and qualitative data. The quantitative database will be taken from a survey of high school students living and studying in Ho Chi Minh City. The qualitative database is taken from in-depth interviews focusing on teachers, parents, and students. The article presents the main results of the research. First, focus on the research basis including subjects, objects, and research methodology. Second, include views on suicidal thoughts and self-harm from many different perspectives, manifestations and causes of these behaviors, the prevalence of self-harm/suicidal thoughts, and consequences. Third, conclude and propose some recommendations to minimize the problem

Machine Learning Models for Inferring the Axial Strength in Short Concrete-Filled Steel Tube Columns Infilled with Various Strength Concrete

Concrete-filled steel tube (CFST) columns are used in the construction industry because of their high strength, ductility, stiffness, and fire resistance. This paper developed machine learning techniques for inferring the axial strength in short CFST columns infilled with various strength concrete. Additive Random Forests (ARF) and Artificial Neural Networks (ANNs) models were developed and tested using large experimental data. These data-driven models enable us to infer the axial strength in CFST columns based on the diameter, the tube thickness, the steel yield stress, concrete strength, column length, and diameter/tube thickness. The analytical results showed that the ARF obtained high accuracy with the 6.39% in mean absolute percentage error (MAPE) and 211.31 kN in mean absolute error (MAE). The ARF outperformed significantly the ANNs with an improvement rate at 84.1% in MAPE and 65.4% in MAE. In comparison with the design codes such as EC4 and AISC, the ARF improved the predictive accuracy with 36.9% in MAPE and 22.3% in MAE. The comparison results confirmed that the ARF was the most effective machine learning model among the investigated approaches. As a contribution, this study proposed a machine learning model for accurately inferring the axial strength in short CFST columns

FACTORS INFLUENCING VIETNAMESE STUDENTS’ CHOICES TO ATTAIN ENGLISH PROFICIENCY STANDARDS IN A UNIVERSITY IN VIETNAM

In the current era of globalization, English is considered a necessary skill for education and work and a criterion for evaluation in recruitment and graduation assessments in many places in Vietnam. According to the project entitled "Teaching and Learning Foreign Languages in the National Education System Phase 2008 - 2020", non-English majored university students must achieve a minimum of Level 3 according to the 6-level Foreign Language Proficiency Framework used in Vietnam. Several universities have diversified their ways to meet these standards to facilitate students in meeting the English language outcomes, allowing students more opportunities to choose ways that are suitable for them. However, this also indicates that various influencing factors will impact students' selection of ways to meet these standards. This research explores the primary ways students choose to fulfill English language standards as stipulated and analyzes the factors influencing the choices of non-English major students in universities in Vietnam.  Article visualizations

Humibacter ginsengiterrae sp. nov., and Humibacter ginsengisoli sp. nov., isolated from soil of a ginseng field

Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil of a ginseng field in the Republic of Korea. 16S rRNA gene sequence comparisons showed the two novel strains were closely related to members of the genus Humibacter with greatest similarity to Humibacter antri KCTC 33009T (98.8 and 98.4 % for DCY60T and DCY90T, respectively). The predominant menaquinones present were MK-11 and MK-12. The major fatty acids were anteiso-C17 : 0 and summed feature 8 containing C18 : 1ω7c and/or C18 : 1ω6c. The DNA G+C contents of strains DCY60T and DCY90T were 62.8 and 66.8 mol%, respectively. The peptidoglycan of both strains contained the amino acids ornithine, 2,4-diaminobutyric acid, alanine, glutamic acid and glycine. The cell-wall sugars of strain DCY60T comprised glucose, galactose, rhamnose and xylose, while strain DCY90T contained glucose, galactose, rhamnose and ribose. The major polar lipids of both strains were phosphatidylglycerol, an unidentified glycolipid, and an unknown phospholipid. On the basis of the phenotypic analysis strains DCY60T and DCY90T represent novel species of the genus Humibacter, for which names Humibacter ginsengiterrae sp. nov. (type strain DCY60T = KCTC 33520T = JCM 30079T) and Humibacter ginsengisoli sp. nov. (type strain DCY90T = KCTC 33521T = JCM 30080T) are proposed

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

NEW RECORDS OF DOPASIA GRACILIS (SQUAMATA: ANGUIDAE) IN BACH MA NATIONAL PARK, THUA THIEN-HUE PROVINCE

This article describes the morphological characteristics of Dopasia gracilis (Gray, 1845) from Bach Ma National Park, Thua Thien-Hue province. The number of specimens in Bach Ma is bigger compared to description of Smith in 1935, and also Nguyen et al. in 2011. In Vietnam, D. gracilis has been reported from the following provinces: Cao Bang, Yen Bai, Ha Giang, Quang Binh, Quang Ngai and Gia Lai. So, in Bach Ma National Park it is the first record of this species distribution.NOI ÎNREGISTRĂRI ALE DOPASIA GRACILIS (SQUAMATA: ANGUIDAE) ÎN PARCUL NAȚIONAL BACH MA, PROVINCIA THUA THIEN-HUEÎn articol sunt descrise caracteristicile morfologice ale speciei Dopasia gracilis (Gray, 1845) din Parcul Național Bach Ma, provincia Thua Thien-Hue. Numărul specimenelor din Bach Ma este cu mult mai mare în comparație cu descrierea elaborată de Smith în 1935 şi de Nguyen et al. în 2011. În Vietnam, D. gracilis a fost raportat în următoarele provincii: Cao Bang, Yen Bai, Ha Giang, Quang Binh, Quang Ngai și Gia Lai. Deci, în Parcul Naţional Bach Ma distribuția acestei specii este înregistrată pentru prima dată.</p

Gauge Bosons in the 3-3-1 Model with Three Neutrino Singlets

We show that the mass matrix of electrically neutral gauge bosons in the recent proposed  model based on $\mathrm{SU}(3)_C\otimes \mathrm{SU}(3)_L\otimes \mathrm{U}(1)_X$ group with three neutrino singlets [9] has two exact eigenvalues and corresponding eigenvectors. Hence the neutral non-Hermitian gauge boson $X^0_\mu$ is properly determined.With extra vacuum expectation values of the Higgs fields, there are mixings among charged gauge bosons $W^\pm$ and $Y^\pm$ as well as amongneutral gauge bosons $Z, Z'$ and $X^0$. From the $W$ boson decay width, we get lower bound on  scale of the model about few TeVs

Determinants Influencing Entrepreneurial Intention in Hanoi, Vietnam

This research employed survey data from 204 students between two groups of  economics and technical majors in Hanoi city for assessing the impact levels of determinants on entrepreneurial intention. The results show that a number of determinants including Need for achievement, Self-efficacy, and Instrumental readiness have positive impacts on student’s entrepreneurial intention. Besides, this study is also to create a basis for  comparative students among different economics and technical majors, work exoperience, and gender. These findings are the basis to recommend policies and solutions to promote entrepreneurship movement in Vietnam. Keywords: Entrepreneurial intention, need for achievement, self-efficacy, instrumental readiness. DOI: 10.7176/EJBM/12-15-10 Publication date:May 31st 2020