Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

Self-injurious Behavior of Children with Autism in Vietnam: Across Sectional Study

This study explored self-injurious behaviour (SIB) of autistic children in Vietnam through a crosssectional design. 60 informants, including 57 parents and 3 caregivers completed the questionnaire on problem behaviour consisting of aggression, self-injury, stereotyping, property destruction, other problem behaviours and their functions. Results revealed that children experienced all mentioned problem behaviours, especially self-injurious behaviour. The topographies of self-injurious behaviour of the children included head-hitting, head-scratching, head-banging, hair-pulling, face-hitting, facepuncturing with a pen, ear-scratching, lip-picking, hand-biting, hand-scratching, hand-pinching, and belly-scratching. The most common area of self-injurious behaviour is the head. The functions of these problem behaviours were expressed in four types (social positive reinforcement, social negative reinforcement, automatic positive reinforcement and automatic negative reinforcement). Social positive reinforcement appeared as a prominent function. Out of these 57 children, 21 of them who were autistic with self-injurious behaviour went through a functional behaviour assessment (FBA) in which the four conditions known as attention, tangible items, escape from task/activities, automatic stimulation were tested. The results of functional behaviour assessment (FBA) further indicated the correspondence between the FAST-R and FBA outcome on function of problem behaviour, especially self-injurious behaviour. The research concluded that the prominent function of these self-injurious behaviours was social function. It means self-injurious behaviours usually occur within a condition of social interaction, especially, in this present study, in the tangible condition. The antecedent of selfinjurious behaviour is the removal of tangibles (e.g. food, preferred items). This paper contributes to our knowledge of self-injurious behaviour of children with autism in Vietnam where empirical research of this field was still very rare

EVALUATION OF THE VULNERABILITY OF THE COASTAL SOCIO-NATURAL SYSTEMS (EXAMPLE FROM KHANH HOA COASTAL ZONE)

Joint Research on Environmental Science and Technology for the Eart

Preparation of Ti/TiO2-PANi electrodes by combining method of thermal treatment with polymerization processing and their electrochemical property

Ti/TiO2-PANi-electrodes were synthesized by combining method of thermal treatment of titanium substrate with chemical polymerization processing of aniline on which. Their morphological structure was observed by scanning electron microscopy. The presence of PANi and TiO2 were indicated by infrared spectra and X-ray diffraction, respectively. Their electrochemical properties were characterized by cyclic voltammetry and impedance spectroscopy. The results showed that their photoelectrochemical property with light on in 0.5 M H2SO4 indicating a n-conductor that depended on PANi thickness covered TiO2-layer among them the best one obtained by oxidative temperature of 500 oC for 30 minutes during thermal treatment of titanium substrate connected with an immersing into acidic aniline solution for only 8 min during polymerization

Tertiary students’ preferences on extracurricular activities for English learning: Voices from the field of Advanced Program in Biotechnology

In Vietnam, where English plays a vital role in the country’s development, extracurricular activities for English learning are considered an effective reform for enhancing citizens’ English proficiency. Previous studies have showed the positive impact of extracurricular activities on language learners’ outcomes. Yet, almost none of them has investigated students’ voices about what, how, when, and where they want these activities to be organized. This current study was employed to fill that gap in the field of biotechnology (advanced program). A 77-item questionnaire was sent to 148 students who learned biotechnology in an advanced program at a tertiary institution in the Mekong Delta of Vietnam. The results indicated the students preferred mental activities (M=4.00) to others. Moreover, they would like to travel to experience cultures from English-speaking countries (M=4.11). Further extracurricular activities were encouraged to be organized on their university campus (M=3.63). The students also preferred short-term activities at weekends to those that were organized over a long period. The study proposed a model for further extracurricular activities at the end of this writing

Effects of oil and grape seed tannin extract on intakes, digestibility, milk yield and composition of Saanen goats

An experiment was conducted as a 4×4 Latin square design using 4 lactating Saanen goats, 19 months old and 47.9±1.04 kg of body weight, to evaluate the effect of oil and grape seed tannin extract (GSTE) supplementation on feed intake, digestibility, milk yield and milk composition. Each experimental period lasted for 21 days including 16 days for adjustment and 5 days for sampling. Goats were fed a control diet (Ctrl) consisting of 60% concentrate and 40% fresh Para grass (dry matter, DM, basis) while other 3 treatments were supplementation of 2.5% soybean oil (SO); 2.5% soybean oil + tuna fish oil at 3:2 w:w (SFO); 2.5% soybean oil + tuna fish oil at 3:2 w:w + 0.8% GSTE (OCT). The results showed that oil and GSTE did not affect feed intake, digestibility, milk yield and composition of goats (P > 0.05). However, digestibility of EE was higher (P < 0.05) in SFO and OCT diets (85.4% and 84.7%, respectively) compared with Ctrl (76.2%). Combined data suggested that feeding 2.5% oil blend with or without 0.8% GSTE increased EE digestibility in goats without affecting intake, animal performance and milk composition

Constituents from stem barks of Anacolosa poilanei Gagnep. (Olacaceae)

Four compounds were isolated from the stem barks of Anacolosa poilanei Gagnep. Theirs structures were established by spectroscopic analysis including MS and NMR. Accordingly, the isolates were identified as trichadenic acid B (1), trichadonic acid (2), amentoflavone (3) and β-sitosterol (4)

Optimization of the leaching process of the printed circuit boards production’s sludge for copper recovery via electrolysis

Copper is the main component of printed circuit boards (PCBs) which is the main part of an electronic device. The manufacture of PCBs often releases huge amount of sludge which contained copper. Derived from the demand of the industrial park about the wasted sludge treatment and the reducing of the plantation of natural mineral resources, the copper recovery process from PCBs manufacture's wasted sludge was studied. The process of copper leaching by sulfuric acid solution was studied using experimental planning methods using the simulation software Modde 5.0. The parameters were calculated and simulated to evaluate the effect of the acid concentration, leaching time, and the ratio between the solid and liquid phases on the leaching efficiency. The obtained results by simulation were compared with real experimental results. The obtained results from this study are planning in the actual deployment of the Hanoi Urban Environment One Member Limited Company in Vietnam. Keywords. Printed circuit board, copper sludge, leaching