In this study, we examined the effect of lightintensity and light cycle on the growth of hydroponic leaf lettuce. Four light intensity treatment were using included 1 LED light NCM 3000K – purple LED: 75% red, 25% blue (48 μmol.m-2.s-1 PPFD - Photosynthetic photon flux  density); 2 LED lights NCM 3000K – purple LED: 75% red, 25% blue (80 μmol.m-2.s-1  PPFD); 3 LED lights D NCM01 L/30W – White LED (60 μmol.m-2.s-1 PPFD) and 3 LED lights NCM 3000K – purple LED: 75% red, 25% blue (115 μmol·.m-2.s-1  PPFD), with a combination of fivelight cycles 6/18, 9/15, 12/12, 18/6, 24/0 (light/dark). The result showed thatthe combination of 80-24/0 (2 purple LEDs – 24 hours light /0 hour dark) resulted highest fresh weight (34.93 g) and the seconds highest in the 60-24/0 (3 whiteLEDs -24 hours light /0 hour dark) and 80-18/6 (2 purple LEDs – 18 hours light /6 hour dark) treatment (28.95 and 27.22 g), while control 2 treatment (grown under sunlight) was 11.62 g. The main stem was highest at combined of 3 white LEDs with 24/0 and 18/6 treatments (26.18 and 20.04, respectively), while the numer of leaves (17.60 and 16.38 leaves), leaf length (10.31 and 10.97 cm) and leaf width (9.91 and 7.36 cm)at combined treatment of 2 purple LEDs with 18/6  and 24/0 were higher than most of anothers.The combination of 18/6 and 24/0 with 2 and 3 purple LEDs showed highest Chlorophyll value (3.92-4.75 µg/g), lowest at combination of 6/18 with four different light intensity (1.25-1.40 µg/g).

A study was conducted at the experimental farm of Can Tho University in Vietnam. The aim of this study was to evaluate the effects of different dietary crude protein levels on growth performance and nutrient digestibility of growing Californian rabbits. Sixty Californian rabbits at 42 days of age were arranged in a complete randomized design with 5 treatments and 3 replications. Four rabbits including 2 males and 2 females were in one experimental unit. Five treatments were different protein levels of 15, 17, 19, 21 and 23%, respectively. The apparent nutrient digestibility and nitrogen retention of the rabbits was measured at 12 weeks of age in 7 days.  This experimental period was 12 weeks. The results of study showed that DM and ME intakes were not significantly different (P>0.05), however CP intake was significantly different (P 

Water hyacinth silage (EWH) was used in this experiment. Four growing sheep (19.8±0.43kg) were allocated in a 4x4 Latin square design with 4 treatments including Para grass (EWH0), replacement of 15% Para grass by ensilaged water hyacinth (EWH15), replacement of 30% Para grass by ensilaged water hyacinth (EWH30), replacement of 45% Para grass by ensilaged water hyacinth (EWH45). The study aimed to evaluate effects of replacement of ensilaged water hyacinth (Eichhornia crassipes) to Para grass (Brachiaria mutica) in the diets (DM basis) on feed intake, rumen parameters, nutrient digestibility and nitrogen retention of growing sheep. There was a supplementation of coconut meal, soybean cake and urea to adjust the CP content of diets being 17%. Each experimental period was 14 days including 7 days for adaptation and 7 days for sample collecting. The results showed that DM, OM, CP and NDF of EWH were 19.0, 84.2, 11.2 and 54.2 %, respectively. The DM and CP intake were similar (P>0.05) among the treatments, however, the NDF intake was significantly higher for the EWH0 and EWH15 as compared to EWH30 and EWH45. The nutrient digestibility (DM, OM, CP, NDF) were not significantly different (P>0.05) among treatments and ranged from 66.4 to 67.3%. The results indicated that EWH could be used to replace Para grass at a level of 30% in growing sheep diet.   

The aim of this paper is to analyze static voltage stability of Vietnam power network at the level of 500 kV with the connection of the nuclear power plant and apply STATCOMs to improve the voltage stability of the system. Power system simulator for engineer (PSS/E), which is a powerful software for power system transmission analysis and generation performance in steady state and dynamics conditions, is employed for implementing and analyzing static voltage stability in this paper. To put it another way, P-V and Q-V analysis are carried out to assess both voltage stability and transfer capability of the power network corresponding to the normal operation mode and contingency modes. The purpose of the analysis is to define the unstable voltage buses and contingencies that potentially affect the voltage stability. Moreover, STATCOMs application to enhance voltage stability, power transfer as well as voltage quality of the Vietnam’s power system is carried out.

The application of a data based mechanistic modeling approach to predict thermal histories of conductive foodstuffs during heating is reported. In the experiment, minced fish was completely filled in 307x113 steel cans as the conductive food. Step increase in heating medium was applied while the product temperature was recorded. The simplified refined instrument variable algorithm was used as model parameter identification tool to obtain the best model order and parameters. A first order transfer function model proved to be sufficiently good in describing the heat transfer from heating medium to product with a high statistical significance (R2 > 0.99). In this model, a parameter related to the heat transfer coefficient was found and could be used to predicting of product temperature during heating processes.

This work describes the isolation and characterization of 3 compounds, including physalin B (1), physalin G (2) and quercetin 3-O-rutinoside (3) from the dichloromethane and n-butanol extracts of the aerial parts of the medicinal species Physalis angulata L. collected from Dong Thap province. The chemical structures were elucidated based on various spectra data (ESI-MS, 1D- and 2D-NMR spectroscopy) and by comparing with known spectral data. For the frist time, the inhibition activity of physalin G on α-glucosidase enzyme was announced.

The research, conducted in Phung Hiep District, Hau Giang Province, aims at identifying factors which have impacts on the vocational training needs in rural areas in order to understand the labor forces and how these factors affects labor's needs in vocational training. 7 main factors are: Age (X1), Gender (X2), Education (X3), Household's size (X4), number of labor in household (X5), household's total income (X6) and availability of information about vocational training (X7). The 7 factors are analyzed by Binary Logistic Regression with the likelihood of 83.5% in which X1, X2,X3, X4, X5, X6 have statistically significant while X7 (Sig. = 0,371>0,05) has not. Besides, statistics on number of labor in household shows that households having 4 labors make up the highest ratio (38.5%)

A large number of studies have been conducted to explore the attitudes and motivation of students toward different varieties of English in order to improve the English proficiency level of students in Can Tho University, especially English-majored students. To add to more venues to these issues, this study would be done with the objectives (1) to investigate English-majored students' attitudes toward speaking learning with English-speaking volunteers and (2) to discover whether English-majored students are more intrinsically and extrinsically motivated toward speaking English with English-speaking volunteers. Both quantitative and qualitative methods were used for data collection. A total of 103 English-majored students participated in the questionnaire, 10 participants randomly selected from the sample to join the interview. The study showed that (1) English-majored students had positives toward speaking English with English-speaking volunteers, and that (2) the students were more intrinsincallymotivated than extrinsically motivated. Besides, qualitative data released opinions of what English-speaking volunteers and administrators should do to enhance students' attitudes and motivation toward speaking learning with English-speaking volunteers. possible recommendations for future research were also addressed. 

Task based language teaching (TBLT) is currently being introduced throughout Asia and has emerged as a central concept from a study of curriculum guidelines and syllabi in the Asia Pacific countries. In some countries such as China, Taiwan, Hong Kong, TBLT has been strongly promoted in English language education policies . However, in practice, recent research shows that Asian teachers still prefer long-standing presentation- practice-production (PPP).  In that context, this case study used diary methods and stimulated recall interviews to investigate specific obstacles that a Vietnamese teacher had to overcome when implementing TBLT in her writing classroom while she had more knowledge of and experience with PPP. Teaching one undergraduate class of writing under task-based instruction and another under more teacher-directed instruction – PPP for one semester, the teacher had a lot to tell about the challenges she faced when implementing TBLT. 

In this study, crude polysaccharides were extracted from brown seaweed Sargassum flavicans with three extraction solvents including hot-water (SF1), 0.1N HCl (SF2), and 90% aqueous ethanol (SF3). The extracts were then analyzed for chemical composition and antioxidant activity. The results showed that among three extraction solvents, 0.1N HCl extract exhibited higher yield (41.1%), followed by hot-water (24.5%) and 90% aqueous ethanol solvent (12.8%). The color of these freeze-dried extracts changed from brown (SF1 and SF2) to brown green (SF3). The crude protein concentrations were 3.6, 6.1, and 5.2% for SF1, SF2, and SF3, respectively. Extract SF2 had higher concentration of total phosphorus (0.34%) than that of SF1 (0.17%). Total phlorotannin concentrations of extracts were in the range of 0.27-0.47%. Also, extract SF2 had the highest percentage of sulfate content (3.5%). The free radical scavenging activity, ferrous ion chelating activity, and ferric reducing power of extracts were increased with increasing of concentrations of polysaccharides. Polysaccharide was extracted by 0.1N HCl (SF2) showed the highest antioxidant activity. These results indicated that the polysaccharide extracts of brown seaweed S. flavicans possessed a good antioxidant activity.

The objective of this study was to evaluate dynamics of nitrogen in intensive whiteleg shrimp (Litopenaeus vannamei) culture in tanks and integration with hybrid constructed wetlands (CWs). The CWs planted with Typha orientalis (C. Presl) and unplanted CWs were arranged inthree replications, while control (without CWs) was duplicates. Water from the shrimp tanks was distributed to the hybrid CWs and their outlets were recycled back to the shrimp tanks that were studied at 5-10‰ of salinity. The hybrid CWs consists of a vertical subsurface flow (VF), horizontal subsurface flow (HF) and surface flow (SF). The entire systems were operated at a recirculation rate of 11.4 L/min (equivalent to 100% volume shrimp tank per day). Water quality in the shrimp tanks was monitored every two weeks. The results showed that while the concentrations of NO2-N and NH3-N were increased overtime but they were still in the suitable range for whiteleg shrimp growth. Taken together the results indicated that the wetland system helped to maintain water quality in intensive recirculating shrimp culture tanks without water exchange.

Streptococcus iniae, as a cause of Streptococcosis outbreak of cultured tilapia, is a hemolytic, Gram-positive bacterium. In this study, a one-step PCR method was developed for the detection of S. iniae from fish kidney. The oligonucleotide primers, assigned as LOX-1 and LOX-2, are designed from lactate oxidase gene of S. iniae. Using extracted DNA from bacterial cells or head kidney of S. iniae infected fish, the PCR reaction yields a 870 bp fragment specific to the S. iniae sequence. Primers LOX-1 and LOX-2 did not amplify DNA from other common bacteria in cultured fish (Streptococcus agalactiae, Aeromonas hydrophila, Edwardsiella ictaluri, Vibrio harveyi). The detection limit of this primer pair is 102 CFU/ml of S. iniae. The improved one-step PCR method provides a diagnostic tool for: (i) the detection of S. iniae directly from infected fish tissue; (ii) and the identification of S. iniae from bacteria cell.

A stochastic model for daily clearness index sequence in Can Tho city has been proposed. This model based on a pair of stochastic processes, called the state process and the observation process. The random dynamic of meteorological regimes in random medium will be modellized by the state process, a hidden homogeneous Markov chain. The observation process, which represent the daily clearness index sequences, will be formed by a real valued function whose values are corrupted by Gaussian noise. Model parameters are estimated from the real data using Maximum Likelihood estimation via Expectation Maximization algorithm. The simulated data will be used to estimate the experimental distribution of daily clearness index sequences.

The studies “Determinants of access to formal credit of industrial and constructional Small and Medium Enterprises (SMEs) in Can Tho City of Viet Nam”. The study used primary data from 200 industrial and construction SMEs in the Can Tho City in 2013. Using the Probit model, the findings have showed that three factors including number of operational years in business of the enterprises, the scale of enterprises and the enterprises’ revenue growth rates are statistically significant affect on the ability to access credit by SMEs. The results implied possible solutions to improve the possibility to access to formal credits industrial and constructional SMEs given by financial institutions, to assist the Enterprises to invest and widen their production and performance.

This paper investigated production and distribution of agri-product value chains in the Mekong Delta of Vietnam.  The analysis was driven by key questions relating to 1) problems of agri-product chains, 2) solutions for upgrading agri-product chains in general and 3) key messages and solutions for each value chain of four main products in the Mekong Delta towards sustainable development. The study methodology included the value chain approach of Kaplinsky & Morris (2001), the ValueLinks method of GTZ (2007); Marking value chains work better for the poor (M4P, 2008) and participation of 1,759 chain actors and stakeholders. The conclusions indicated that there were many difficulties and challenges in agri-product value chains in the Mekong Delta including (i) in-efficient production from many stages in the chains, (ii) high production cost, (iii) lack of vertical and horizontal linkages in production and distribution; and (iv) low product quality that need to be solved in order to meet market demands. Many solutions were proposed for upgrading agri-product value chains in general and for six main products in particular in terms of market information, value chain approach, techniques, linkage development and policies.