Experimental study of the long-term shortening of reinforced concrete columns under maintaining concentric axial load

This paper presents the results of an experimental study to measure the shortening of reinforced concrete (RC) columns under long-term maintaining concentric axial load. Long-term axial deformation due to shrinkage and creep of the concrete were recorded beside deformation due to mechanical load. Eight RC cylinder - columns (content of reinforcement 1.5% and 2%) with diameter of 150 mm and height of 600 mm were tested during the period of 600 days to determine their shortening. The experimental results showed that the long-term deformation of RC columns occurs primarily during the first year of loading. The deformation creep of concrete is much greater than the shrinkage deformation. The reinforcement content has a significant effect on the long-term deformation of concrete columns

Experimental study of the long-term shortening of reinforced concrete columns under maintaining concentric axial load

This paper presents the results of an experimental study to measure the shortening of reinforced concrete (RC) columns under long-term maintaining concentric axial load. Long-term axial deformation due to shrinkage and creep of the concrete were recorded beside deformation due to mechanical load. Eight RC cylinder - columns (content of reinforcement 1.5% and 2%) with diameter of 150 mm and height of 600 mm were tested during the period of 600 days to determine their shortening. The experimental results showed that the long-term deformation of RC columns occurs primarily during the first year of loading. The deformation creep of concrete is much greater than the shrinkage deformation. The reinforcement content has a significant effect on the long-term deformation of concrete columns

Ripplon Modes of Two Segregated Bose-Einstein Condensates in Confined Geometry

The ripplon modes of two segregated Bose-Einstein condensates (BECs) confined by one and two hard walls are respectively studied by means of the hydrodynamic approach within the Gross-Pitaevskii (GP) theory. For the system at rest we find that due to the spatial restriction the dispersion relations are of the form $\omega \sim {k^2}$ in low momentum limit for both cases, while for the system in motion parallel to the interface the dispersion relations for both cases are $\omega \sim k$ at low momentum limit and, furthermore, the system becomes unstable

The Transition in Goods Export Structure in the Northeast Region of Vietnam

The period 2005-2015 is an important stage in the preparation process of bringing Vietnam to basically become an industrialized country by 2020. The economic development of the Northeast with an open and export-oriented economy requires an important role of export activities in the region's socio-economic development. Although it is affected by the global economic crisis, the export value of the region has increased significantly, the structure of exports over the years has positively changed. In more detailed, the rate of raw goods slightly reduced. However, the restructuring of the region's exports has not made a breakthrough and failed to create a suitable structure of export products and made full use of the region’s advantages and potentials. The slow change of exports structure will lead to resource depletion, ecological imbalance, and poor economic efficiency. Keywords: Structure restructuring, Import and export, Northeast of Vietnam, PRODY, export commodities

Novel exopolysaccharide produced from fermented bamboo shoot-isolated Lactobacillus fermentum

This study aimed at providing a route towards the production of a novel exopolysaccharide (EPS) from fermented bamboo shoot-isolated Lactobacillus fermentum. A lactic acid bacteria strain, with high EPS production ability, was isolated from fermented bamboo shoots. This strain, R-49757, was identified in the BCCM/LMG Bacteria Collection, Ghent University, Belgium by the phenylalanyl-tRNA synthetase gene sequencing method, and it was named Lb. fermentum MC3. The molecular mass of the EPS measured via gel permeation chromatography was found to be 9.85 × 104 Da. Moreover, the monosaccharide composition in the EPS was analyzed by gas chromatography–mass spectrometry. Consequently, the EPS was discovered to be a heteropolysaccharide with the appearance of two main sugars—D-glucose and D-mannose—in the backbone. The results of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance spectroscopy analyses prove the repeating unit of this polysaccharide to be [→6)-β-D-Glcp-(1→3)-β-D-Manp-(1→6)-β-D-Glcp-(1→]n, which appears to be a new EPS. The obtained results open up an avenue for the production of novel EPSs for biomedical applications

Decoding the capability of Lactobacillus plantarum W1 isolated from soybean whey in producing an exopolysaccharide

This study aims at producing exopolysaccharides (EPS) from a lactic acid bacterial strain. The soybean whey-isolated Lactobacillus plantarum W1 (EPS-W1), which belongs to genus Lactobacillus, is identified using the phenylalanyl-tRNA sequencing method. Of all the examined strains, R-49778 (as numbered by BCCM/LMG Bacteria Collection, Ghent University, Belgium) showed the highest capability of producing exopoly-saccharides. Structural characterization revealed a novel exopolysaccharide consisting of repeating units of -> 6)-D-Glcp-(1 ->; -> 3)-D-Manp-(1 ->; -> 3)-6-Glcp-(1 -> and a branch of -> 6)-D-Manp-(1 ->; -> 2)-D-Glcp-(1 ->. This discovery opens up avenues for the production of EPS for food industries, functional foods, and biomedical applications

Effect of cultural conditions on antimicrobial activity of marine-derived fungus Penicillium chrysogenum

Marine fungi are a potential source of structurally diversified bioactive secondary metabolites that are not found in terrestrial sources. In our continuous investigation to search new antimicrobial agents from marine-derived fungi, we isolated fungal strain 045-357-2 from a soft coral sample collected from Ca Na bay, Ninh Thuan, Vietnam. The strain showed high antibacterial activity and was selected for further study. According to Internal Transcribed Spacer (ITS) rDNA molecular methods, the fungus was identified as Penicillium chrysogenum 045-357-2 and had a 100% homology (600/600 bp) with a GenBank sequence from a reference P. chrysogenum strain (NCBI accession no. EF200090). In the present investigation, the fungus was studied on effect of different culture incubation period, pH and salinity for antimicrobial activity against pathogenic microbes including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Streptococcus faecalis, Listeria monocytogenes, and Candida albicans. The ethyl acetate extracts of culture medium of the fungal isolate were determined antimicrobial activity by disc diffusion assay. The results showed that the optimum antimicrobial activity of the fungal strain P. chrysogenum 045-357-2 was obtained in medium containing 20 g rice, 20 mg yeast extract, 10 mg KH2PO4 , and 40 mL natural seawater at 30oC on the 14th day of incubation. The strain also exhibited highest antimicrobial activity in the medium at initial pH 6.0 – 8.0 and salinity of 35 g/L. The findings indicate that cultural conditions significantly influenced on antimicrobial activity of the studied fungus. The optimization is potential use for further study on the mass cultivation and isolation of bioactive compounds for this fungus

Isolation and screening marine fungi with antimicrobial activity from samples collected in Nha Trang bay, VietNam

The marine environment is an extremely complex ecosystem and contains a broad spectrum of fungal diversity. Marine fungi have been shown to be tremendous sources for new and biologically active secondary metabolites. The present study aims to isolate and screen antimicrobial properties of 100 fungus strains from different marine sources including seaweeds, soft corals, sponges and sediment collected at Nha Trang Bay, Vietnam. In preliminary experiments, the crude extracts of these fungal isolates with ethyl acetate were screened for their antimicrobial activity against the human microbial pathogens including Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC 19111, Streptococcus faecalis ATCC 19433 and Candida albicans ATCC 10231 by the disc diffusion method. Among the 100 isolates, 59 strains exhibited antimicrobial activity against at least two tested pathogens, that 57% against S. aureus, 50% against L. monocytogenes, 49% against B. cereus, 45% against S. faecalis, 7% against E. coli, 5% against C. albicans, and only 2% against P. aeruginosa. The present study has revealed the presence of high numbers of marine fungi from Nha Trang waters having antimicrobial properties and they need to be investigated further for natural bioactive products

PRE-ENGINEERED (PACKAGE/AND OR ON-SITE) WASTEWATER TREATMENT PLANTS

Joint Research on Environmental Science and Technology for the Eart