Study on the Use of Construction and Demolition Waste for Road Base or Subbase Pavement Construction in Hanoi

Reuse or recycling of construction and demolition waste (CDW) has become an inevitable trend in the world. Currently, the amount of CDW generated in Hanoi is estimated at more than 4,000 tons per day, of which only about 30% has been controlled and recycled. The CDW comes from many different sources such as construction, repair, renovation, demolition of houses, residential buildings, public buildings, transportation infrastructure works, etc... The CDW commonly comprises soil, bricks, mortar and concrete, and has been reused in many applications around the world. In Vietnam, there are also some research programs set up for reutilizing the material, however, has not been concretely applied in practice. In order to consider the applicability of CDW in road construction, an experimental program was conducted using CDW as the aggregate for the cement treated grain material base layer in road pavement structure. The weight ratios of cement used in the mixture were 4%, 5%, 6%, 7% and 8%. The test results showed that the main mechanical properties of compressive strength, split tensile strength and elastic modulus of the mixture, increased proportionally with the cement content in the mixture

STUDENTS’ PERCEPTIONS OF ACTIVE LEARNING IN INTRODUCTION TO LITERATURE

There is a growing interest in active learning as a shift from traditional lecturing to improving student-centred learning in English. However, in the Vietnamese context of teaching and learning at tertiary levels, little research has examined students’ perceptions of active learning in approaching Introduction to Literature. This study is therefore aimed to look into this area of interest. Participants in this study were 94 students from junior and seniors majoring in high-quality programs at a university in the Mekong Delta. Data were collected from questionnaires. The findings show that students had positive perceptions of active learning in studying this course. Implications for teaching and learning this course are made.  Article visualizations

Colloque scientifique à Ha Noi, à l'occasion du cinquantenaire de la culture Hoa Binh

Huy Thong Pham. Colloque scientifique à Ha Noi, à l'occasion du cinquantenaire de la culture Hoa Binh. In: Bulletin de l'Ecole française d'Extrême-Orient. Tome 73, 1984. pp. 355-357

Colloque scientifique à Ha Noi, à l'occasion du cinquantenaire de la culture Hoa Binh

Huy Thong Pham. Colloque scientifique à Ha Noi, à l'occasion du cinquantenaire de la culture Hoa Binh. In: Bulletin de l'Ecole française d'Extrême-Orient. Tome 73, 1984. pp. 355-357

Studies in Viet Nam on Austronesian Languages and Peoples

Proceedings of "Origin and Expansion of the Austronesians

Empirical Study of Software Defect Prediction: A Systematic Mapping

Software defect prediction has been one of the key areas of exploration in the domain of software quality. In this paper, we perform a systematic mapping to analyze all the software defect prediction literature available from 1995 to 2018 using a multi-stage process. A total of 156 studies are selected in the first step, and the final mapping is conducted based on these studies. The ability of a model to learn from data that does not come from the same project or organization will help organizations that do not have sufficient training data or are going to start work on new projects. The findings of this research are useful not only to the software engineering domain, but also to the empirical studies, which mainly focus on symmetry as they provide steps-by-steps solutions for questions raised in the article

Combined steam and CO2 reforming of methane for syngas production over carbon-resistant boron-promoted Ni/SBA-15 catalysts

The unpromoted and B-promoted 10%Ni/SBA-15 catalysts synthesized via sequential incipient wetness impregnation approach were assessed for combined steam and CO2 reforming of methane (CSCRM) at various reaction temperatures of 973–1073 K and stoichiometric feed composition. An expected and noteworthy drop in mean NiO crystallite size and BET surface area with boron promotion from 1% to 5%B loading could be due to the agglomeration of B2O3 particles and deboration reaction during calcination and hence blocking mesopores of SBA-15 support at elevated B composition. The complete NiO reduction to metallic Ni0 form was achieved during H2 activation and the reduction temperature of NiO phase was shifted towards higher temperature with B-addition owing to enhancing interaction between the acidic B2O3 and basic NiO phases. For all reaction temperature employed, 3%B appeared to be the optimal promoter loading in terms of reactant conversions and 3%B-10%Ni/SBA-15 catalyst revealed the greatest H2 yield (69.4%) at 1073 K. In addition, CH4 and CO2 conversions were enhanced about 23.2% and 32.4%, correspondingly with rising reaction temperature from 973 to 1073 K. Ratio of H2 to CO varied from 1.26 to 2.71 and the desired H2/CO ratio of about 2 favored for Fischer-Tropsch synthesis was achieved on 3%B-10%Ni/SBA-15 sample at 973 K. Boron promoter suppressed graphitic carbon formation and the amount of carbonaceous deposition was reduced about 4 times. Noticeably, 3%B-10%Ni/SBA-15 was also resilient to metallic Ni0 re-oxidation throughout CSCRM