PHOTOCATALYTIC DEGRADATION OF PARAQUAT USING N-TiO2/SiO2 UNDER VISIBLE LIGHT

In the present paper, photocatalytic degradation of paraquat using N-TiO2/SiO2 with different molar ratio of titanium: nitrogen (Ti:N) under visible light was investigated. The catalyst was prepared via immersed SiO2 in N-TiO2. N-TiO2 was synthesized by sol-gel method.  The N-TiO2/SiO2 catalyst was characterized using X-ray diffraction, UV diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy. The results from characterizations indicated that N-doped anatase TiO2 had a 20-25 nm size. Degradation of paraquat, at an initial concentration of 10 mg/L was determined by UV-Vis. Chemical oxygen demand (COD) was used for process performance. Based on the COD tests, the COD values in residual paraquat was lower than that in initial paraquat concentration after 8 hours illumination of visible light. Moreover, the experiment’s results indicated that 80% of paraquat was degraded within 8 h of illumination time. These results showed that N-TiO2/SiO2 with molar Ti:N=2:1 gives the highest degradation efficiency of paraquat under visible light. This catalyst was stable and reusable suggesting it can be applied to treat organic pollutant in water.

Osteogenesis activity of fractions extracted from Clinacanthus nutans (Burm. F.) Lindau

Osteogenesis activity of fractions extracted from Clinacanthus nutans was evaluated on an in vitro model using osteoblast MC3T3-E1 cells. The results showed that all fractions, including ethanol (EtOH), n-hexane, ethyl acetate (EtOAc) and butanol (BuOH) were not significantly toxic to the osteoblast cells at the test concentrations of 5, 10, 25, and 50 µg/mL. The EtOH and EtOAc fractions exhibited the highest osteogenesis activity in terms of enhancement of alkaline phosphatase (ALP) and mineralization activity of MC3T3-E1 cells, especially the EtOAc fraction which increased ALP activity up to 30% and mineralization activity up to 100%. Thus, the EtOAc fraction shows osteogenesis activity through stimulating activites of the two markers for bone generation including ALP and mineralization in osteoblast cells. The fraction is now under extensive investigation to isolate and fully understand the modes of action of the active compounds. 

Effects of different nutrient solutions on growth and flower quality of gerbera (Gerbera jamesonii) grown in hydroponic close system

The nutrient solution is the decisive factor for the growth and development of hydroponic plants. This study was conducted to determine the effect of five nutrient solutions, namely, Hoagland, Knop, Hydro Umat F, BKFAST, and Bio-Life, on the growth and development of gerbera (Gerbera jamesonii) in the hydroponic system. The results show that Hydro Umat F is the most suitable solution for planting gerbera in terms of plant height, number of leaves, leaf size, and root volume. In addition, the flower yield of the gerbera plants nourished on Hydro Umat F is also the highest, with 8.7 flowers per plant after five months in the hydroponic system. The flowers have a diameter of 9.8 cm and natural durability of 19.67 days. Meanwhile, gerbera plants stop growing after 15 days in the Bio-Life solution and 30 days in the Knop solution

Preparation and characterization of magnesium hydroxyapatite coatings on 316L stainless steel

Magnesium hydroxyapatite coatings (MgHAp) were deposited on the surface of 316L stainless steel (316L SS) substrates by electrodeposition technique. Different concentrations of Mg2+ ion were incorporated into the apatite structure by adding Mg(NO3)2 into electrolyte solution containing 3×10-2 M Ca(NO3)2, 1.8×10-2 M NH4H2PO4 and   6×10-2 M NaNO3. With Mg2+ concentration 1×10-3 M, the obtained coatings have 0.2 wt% Mg2+. The influences of scanning potential ranges, scanning times to deposit MgHAp coatings were researched. The analytical results FTIR, SEM, X-ray, EDX, thickness and adhension strength showed that MgHAp coatings were single phase of HAp, fibrous shapes, thickness 8.1 µm and adhesion strength 7.20 MPa at the scanning potential ranges of 0÷-1.7 V/SCE and scanning times of 5 scans. Keywords. 316L SS, Electrodeposition, MgHAp

Uloga osobina ličnosti u oblikovanju poduzetničke namjere: Komparativna studija Južne Koreje i Vijetnama

This paper investigates the role of personality traits in nurturing entrepreneurial intention in South Korea and Vietnam. We developed a research model to examine the integrated influence of both positive entrepreneurial characteristics and dark triad on entrepreneurial intention in South Korea and Vietnam. Primary data was collected from 550 students in South Korea and 700 students in Vietnam using the convenient sampling method in a self-administered questionnaire survey. We used structural equation modelling (SEM) to analyse structural relationships between positive entrepreneurial attributes, dark triads, and entrepreneurial intention in two samples. T-tests were also performed to explore any differences in students’ entrepreneurial intention in South Korea and Vietnam regarding their family background and gender. Findings showed that positive entrepreneurial attributes and dark triads influence entrepreneurial intention differently in the two countries. While the dark triad mainly influenced Vietnamese students’ intention to startup, Korean students received more impact from the positive entrepreneurial characteristics such as risk tolerance, locus of control, and entrepreneurial alertness. Surprisingly, both gender and family tradition do not affect students’ entrepreneurial intention. Based on our findings, we suggested that policymakers and higher education institutions in both South Korea and Vietnam promote students’ entrepreneurial intentions in the future.Ovaj rad istražuje ulogu osobina ličnosti u njegovanju poduzetničkih namjera u Južnoj Koreji i Vijetnamu. Razvili smo znanstveni model za ispitivanje integriranog utjecaja pozitivnih poduzetničkih karakteristika kao i utjecaj mračne trijade na poduzetničke namjere u Južnoj Koreji i Vijetnamu. Primarni podaci dobiveni anketiranjem 550 studenata u Južnoj Koreji i 700 studenata u Vijetnamu prikupljeni su korištenjem prikladne metode uzorkovanja u anketi koju su sami proveli. Koristili smo modeliranje strukturnim jednadžbama (SEM) za analizu strukturnih odnosa između pozitivnih poduzetničkih atributa, tamnih trijada i poduzetničke namjere u dva uzorka. Također su provedeni T-testovi kako bi se istražile razlike u poduzetničkim namjerama studenata u Južnoj Koreji i Vijetnamu s obzirom na njihovo obiteljsko porijeklo i spol. Rezultati su pokazali da pozitivne poduzetničke osobine i mračne trijade različito utječu na poduzetničke namjere u dvije zemlje. Dok je mračna trijada uglavnom utjecala na namjeru vijetnamskih studenata da se pokrenu, korejski studenti dobili su veći utjecaj od pozitivnih poduzetničkih karakteristika kao što su tolerancija na rizik, lokus kontrole i poduzetničke budnosti. Iznenađujuće, spol i obiteljska tradicija ne utječu na poduzetničke namjere studenata. Na temelju naših otkrića, predložili smo da kreatori politika i visokoškolske ustanove u Južnoj Koreji i Vijetnamu promiču poduzetničke namjere studenata u budućnosti

An investigation of the academic consulting competence of high school teachers in Vietnam

High school students must grapple with a host of issues and encounter difficulties when studying at schools, such as peer pressure, test anxiety, cyberbullying, unhealthy relationships, psychological distress, depression and possibly domestic issues. These obstacles create the need for academic consulting in order for high school students to develop essential skills and then solve problems. This study aims to examine the high school teachers' perceptions and the quality of academic consulting competence in the Vietnamese educational context. This study surveyed 1089 high school students and 289 teachers in Ha Noi and Ho Chi Minh City in Vietnam with the 43-item questionnaire. The main results showed that academic consulting competence had been noticed and trained professionally for high school teachers. Additionally, both students and high school teachers recognized the essential role of high school teachers' academic consulting competence in educational settings

Estimation of brain dynamics under visuomotor task using functional connectivity analysis based on graph theory

Network studies of brain connectivity have demonstrated that the highly connected area, or hub, is a vital feature of human functional and structural brain organization. Hubs identify which region plays an important role in cognitive/sensorimotor tasks. In addition, a complex visuomotor learning skill causes specific changes of neuronal activation across brain regions. Accordingly, this study utilizes the hub as one of the features to map the visuomotor learning tasks and their dynamic functional connectivity (dFC). The electroencephalogram (EEG) data recorded under three different behavior conditions were investigated: motion only (MO), vision only (VO), and tracking (Tra) conditions. Here, we used the phase locking value (PLV) with a sliding window (50 ms) to calculate the dFC at four distinct frequency bands: 8-12 Hz (alpha), 18-22 Hz (low beta), 26-30 Hz (high beta) and 38-42 Hz (gamma), and the eigenvector centrality to evaluate the hub identification. The Gaussian Mixture Model (GMM) was applied to investigate the dFC patterns. The results showed that the dFC patterns with the hub feature represent the characteristic of neuronal activities under visuomotor coordination

Forest - Related Culture and Contribution to Sustainable Development in the Northern Mountain Region in Vietnam

The culture of communities living near/in forests indelibly interacts with forest ecosystems, both shaping and adapting to the natural environment. Forest-related cultural dimensions also provide benefits for local economies and social welfare. This study analyses the relationship between local culture and forests of the Tay and the Dao minorities and their contribution to sustainable development in Vo Nhai, a mountainous district in northern Vietnam. The study uses methods of a literature review, participant observation and qualitative interviews with local people. The strong embedded culture with forests that developed over many generations of Tay and Dao people was expressed through their knowledge systems of understanding nature, skills for environmental adaption, health protection and spiritual and recreational activities. The potentials of forest - related culture as a feature of local sustainable development were analysed through contributions in natural resource conservation, economic development and social cohesion. To integrate forest - related culture in sustainable development, some issues need to be better focused on the locality