Polylactic acid (PLA) is made from a natural resource - corn starch and formulated from the condensation polymerization of D- or L- lactic acid or ring opening polymerization of the lactide. It is completely biodegradable, compostable, and can maintain its mechanical properties without rapid hydrolysis even in high humidity conditions. In this review, we study and explain why Poly (lactic acid) is considered as one of the most environment-friendly biodegradable thermoplastic polyesters with extensive applications.

Electrocatalyst material of direct methanol fuel cell (DMFC) with carbon Vulcan supported ruthenium-core and platinum-shell nanoparticles (Ru@Pt/C) was successfully synthesized by a two-step method. H2PtCl6 and RuCl3 precursors were used with the efficient reduction of NaBH4 agent in ethylene glycol (EG). Besides, an alloy structure catalyst sample (Pt-Ru/C) was prepared to compare with the Ru@Pt/C sample. The electrocatalyst samples were investigated by experimental methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), and cyclic voltammetry (CV). The results showed that the Ru@Pt/C electrocatalyst sample was better than the Pt-Ru/C sample with respect to methanol oxidation.

This study presents a method of design and implementation of a position control model, which can be used to test different control algorithms. The system was built based on the Arduino Mega2560 kit and MATLAB/Simulink. Experimental results on the PID controller shows that the response of the model has suitable rise-time, settling time, and small steady-state error. The model satisfies the requirements for setting up anexperimental device for laboratory experiments of control system.

This paper presents some methods for protecting the reinforcing steel in concrete, which are being widely used nowadays and proposes a method that uses polymer materials to protect the reinforcing steel. Concrete with polymer structures is very expensive, and the bending components its compressive areas can help to consolidate the concrete materials densely under working environment which results in the prevention of reinforcement corrosion. In tensile areas, concrete is expanded, resulting in cracks that allows the direct intrusion of environmental elements to the steel in concrete. Therefore, this paper suggests using polymer materials in the tensile region for cost-effectiveness and for preventing the corrosion of reinforcing steel in concrete

Control systems are generally nonlinear in reality, so controller design for nonlinear systems is difficult and traditional control methods are also ineffective. Therefore, modern and intelligent control solution such as model predictive control is preferred. However, when applying model predictive control, it will be difficult to identify the behaviors of the system in the future, especially the one with unknown parameters. This study approaches the application of radial basis function (RBF) neural networks to overcome such limitation. In addition, applying the online training method for the RBF neural network does not require collecting the training data, which cannot always be achieved in practice. The control algorithm was tested on a magnetic levitation system. The simulation results show that the system response follows the reference signal, the setting time is about 2 seconds without overshoot, and steady-state error is negligible. Furthermore, the simulation results also indicate that the control system is stable under the presence of noise and the changing of the object’s mass.

In recent years, the phenomenon of fast sedimentation in rivers causes obstructive water-way traffic. They have also impacted indirectly negatively on the environment and the aquaculture. In addition, rice husk and rice husk ash is uncontrollably discharged into the environment with a large amount, which seriously affects the ecological environment. Unfired brick made from sediment and rice husk ash is the result of the curing process that takes place at atmospheric condition by hydration in the reaction of cement and the geopolymerization in an alkaline environment. This study showed that unfired bricks from sediment and rice husk ash can be the new material that satisfies the needs of construction materials in the future. Unfired bricks have the promising characteristics to help the development of unfired construction materials in the environmentally friendly direction.

The study focused on developing a water-balance dynamic model to simulate water changes in the rice field under a dynamic interaction between rice field and on-farm irrigation system during a rice season and to evaluate the effectiveness of different irrigation techniques (in terms of the amount of irrigated water and pumping times). Six different irrigation techniques (e.g.alternate wetting and drying (AWD), semi-dry cultivation (SDC), shallow water depth with wetting and drying (SWD), saturation, the Vietnamese standard (TCVN:8641-2011) and the actual technique in the field) were applied in the study. The dynamics model was developed in a system-thinking approach software (i.e. STELLA) to simulate water changes during a rice season. Natural conditions of the study area and bio-physical characteristics of the rice crop were collected and applied for all irrigation approaches developed in the numerical model. The results showed that the amount of water used ranged from 854.000 to one million cubic meter per seasonand the number of pumping times ranged from 11 to 23 times per season (for the study area of 120 ha) in accordance with the applied irrigation approach. In addition, the AWD technique was the most effective both in terms of the amount of water and pumping times. The results could be a good scientific base for local authorities to propose suitable irrigation solutions for rice in order to reduce negative impacts of water shortage as in the study area.

The study “Primary treatment of striped catfish processing wastewater by coagulation” was implemented by Jartest apparatus to identify suitable types of coagulant, flocculant and their dosage, then apply the identified parameters to a coagulation - sedimentation unit to test the treatment efficiency for catfish processing wastewater. The experiment results showed that among three tested coagulants, including: aluminum sulfate (Al2SO4.18H2O), ferric chloride (FeCl3.6H2O), and poly-aluminum chloride (Al2(OH)3.Cl3) [PAC], PAC was the most technically feasible coagulant. At the used PAC dose of 500 mg/L, the removal efficiencies of SS and COD were about 68.34% and 61.25%, respectively. The combination of 500 mg/L PAC and 2 mg/L polymer (cation specfloc C-1492 HMW [(C3H5ON)n] led to higher removal efficiency than that of PAC only. The operation of the lab-scale coagulation-sedimentation model with defined parameters from the Jartest experiment showed the removal efficiency of SS, BOD5, COD, TKN and TP were 78.26%, 63.15%, 75.1%, 81.39%, and 73.92%, respectively. The effluent met the suitable criteria for the subsequent treatment by biological processes.

The study of “Evaluation of cat-fish processing wastewater treatment efficiency of aerobic package cage biological contactor” was carried out to determine the efficiency of cat-fish processing wastewater treatment according to aerobic package cage biological contactor with a PVC flexible-conduit medium. A lab-scale aerobic package cage biological contactor was run with hydraulic retention time of 8 hours, rotation speed of 2 rpm, and BOD loading rate on the biofilm area of 0.0037 kg BOD.m-2.day-1. The results showed that the removal efficiency of COD, BOD5, TKN, and TP were 97%, 97.87%, 84.06%, and 63.17%, respectively. It shows that the aerobic package cage biological contactor could be applied as a biological treatment unit to treat cat-fish processing wastewater.

The objectives of the study were to (i) assess the economic efficiency of cropping systems which could improve the farmer’s income, (ii) illustrate the importance of the ecosystem resources, and (iii) raise public awareness on environmental protection in the buffer zones of the U Minh Ha National Park, Ca Mau province. The household interviews were carried out to collect data of socio-economic setting of the study area, from which economic efficiency of the models was calculated. The results showed that the study area was still under-developed, most of people were poor farmers, capital deficiency, lack of farm facilities, low levels of education, outdated farming practices and without applying of science and technology for agricultural practices. Currently there are seven cultivated model as follows: (1) mono rice crop, (2) double rice; (3) Bananas; (4) rice - bananas; (5) rice – bananas - fish; (6) Derris elliptica and (7) Melaleuca forest. The ranking of economic efficiency showed that: bananas, rice – bananas, rice – bananas - fish with the respective profit: 35.052 VND million/ha/year, 39,368 million VND/ha /year and 37.797 million VND/ha/year.

This study was performed considering the general hydrological characteristics and possible impacts of land use change on surface water resources in a small watershed of the Duong Dong river basin in the Phu Quoc island of Kien Giang with the application of the Soil and Water Assessment Tool (SWAT) model. The study is of scarce data with hourly discharge measured in the Duong Dong river from 13th to 20th in June, 2014. The main model parameters were calibrated with data obtained from the measured hydraulics and household surveys. Amongst different parameters, the base-flow alpha factor (APHAL_BF), Manning's ‘n’(hydraulic roughtness) value (CH_N2) and effective hydraulic conductivity (CH_K2) of main channel, saturated hydraulic conductivity (SOL_K), and surface run-off lag time (SUR_LAG) were the most sensitive to the water balance of the basin. On a daily basic, the Nash-Sutcliffe index (calculated based on the measured and simulated data) were of 0,62 and 0,84 for calibration and validation, respectively. In addition, scenarios were built to evaluate changes of surface flows in the basin according to changes of the land cover (from 2005 to 2010), which proved that there were little changes in discharges generated under the two different land-cover scenarios.

Research on the effects of peat thickness on growth indexes of the Melaleuca cajuputi in the U Minh Ha national park was carried out by surveying and measuring the growth indexes of the Melaleuca cajuputi (including: density, diameter and height of trees) with twelve sample plotsat differnet peat thickness levels (peat-free, 30-50cm, 50-80cm and 80-100cm). The area of each sample plot was 100 square meters (10m *10m). The result of the survey shows peat thickness affected the density and total biomass above the ground of the Melaleuca forest. The average density of trees in research zone fluctuatedfrom 1.003 to 1.279 trees/ha and tended to decrease gradually with the increase of the peat thickness. The density of the Melaleuca cajuputi between peat and no peat in the land had a significant difference. The density of Melaleuca cajuputi in two peat thickness levels of 50-80 cm and 80- 100 cm was similar but the difference was found between the two and area of 30-50cmpeat thickness. The average diameter of treatments tended to increase when the peat thickness increased and fluctuatedbetween 16.4 and 18.9 cm. The height of the tree was different between the lowest (30-50 cm) and the greatest peat thickness (50-80 cm).

The National New Rural Construction Program, implemented nationwide since 2010, is amongst the national target programs to enhance on socio-economic development to meet the political and national security. So far the majority of data management has been actually based on the manual managment basic; therefore, planners at the provincial level and other local agencies encountered several challenges in monitoring and evaluating the implemented results of the program in order to propose feasible plans for further development stages. This issue raises an urgent need for renewing the data management system, evaluating the implementation results and utilising maps as a potential approach in annual workplans. This study suggests an alternative solution for the data management by applying the geographic information systems, the so-called New Rural Construction Database Management System (NRCDBMS), for better data management on the New Rural Construction Program in the Vung Liem district, Vinh Long province. The NRCDBMS program has various functions for setting up annual workplans, updating and managing the database. It can also provide maps to illustrate results of different stages of the implementing process. Furthermore, the NRCDBMS program allows planning staffs to synthesize a wide range of data for a rapid assessment of the new rural construction program in different localities of the district. The most significant feature of the NRCDBMS is that planning managers can easily monitor the progress of the program, compare the work plans with the implementing schedules, and automatically update the implemented results of the program by using the developed spatial database.

The purpose of this research is to study antimicrobial and antioxidant activities of Streptocaulon juventas (Merr.). Antimicrobial and antioxidant activities of vine and leaf methanol extracts of S. juventas were tested using the Kirby-Bauer and DPPH methods, respectively. The results proved that the methanol extract of S. juventas had high efficiency in antimicrobial activity with the MIC value at16 µg/ml on two bacterial strains Escherichia coli and Staphylococcus aureus and higher antimicrobial rate than that of the antibiotic ampicillin (MIC = 64 µg/ml) and amoxicillin (MIC E. coli = 64 µg/ml and MIC S. aureus = 16 µg/ml). The results also showed that the DPPH scavenging activity of S. juventas was high (IC50 = 349.35 µg/ml). However, the antioxidant ability was 15.5 times lower than that of vitamin C (IC50 = 22.55 µg/ml).

The purpose of this paper is to study the smoothness of generalized solution for the seccond initial boundary value problem for hyperbolic equation in infinite cylinders with base containing conical points. Some important results on the unique existence, smoothness of the solution for the problem in Sobolev spaces were given.

The study was carried out to determine the anti-bacterial activity of garlic (Allium sativum L.) on Escherichia coli and growth performance of chickens supplemented with 1%, 2%, 3% and 4% fresh garlic in chicken feed. The results showed that all E. coli isolates  were highly sensitive to garlic with MIC 12,5 - 25 µg/ml. Average daily weight gain and feed conversion ratio had no difference between treatments supplemented with fresh garlic and control treatment. However, average daily feed intake in the treatments supplemented with fresh garlic was lower than the control treatment. The results indicated that garlic can be used to prevent the disease caused by E. coli in chickens.

A trial was conducted in the pig farm of Vemedim Co., located at Thoi Thuan district, Can Tho city, to evaluate the reproductive performance of crossed sows (10 Landrace x Yorkshire and 10 Yorkshire x Landrace) at the 2nd and 5rd litters mated with pure Duroc boars and growth performance of their offsprings. Results showed that the litter  size, litter  weight, alive rate of piglets at birth, 21 days and 28 days and weight loss of sows in lactation were not different (P>0.05) between 2  groups of LY and YL. The growth performance of weaned pigs such as weight gain, daily weight gain, feed efficiency, piglet diarrhoea rate was not significant (P>0.05) between 2 groups of DLY and DYL. Benefit income based on the feed and veterinary was higher 1% for the DYL than DLY. Overall, results indicated that improved crossbred LY or YL as basic sows mated to the pure Duroc boar may become effectively in both technique and economic concept for pig meat production in the Mekong Delta of Vietnam.

An experiment was conducted to evaluate the effects of Trafish by-product fat on egg production, quality and culling body weight of Hisex Brown laying hens from 62 to 72 weeks of age in commercial raising system. The study was allocated according to a completely randomized design with Trafish by-product fat (MC) added at 0% (MC0), 2% (MC2), 4% (MC4) and 6% (MC6) in the diets. Results showed that the supplementation of MC did not affect egg production (P=0,46), but egg weight of laying hens was significantly improved as compared with the control diet (P=0,01). Feed intake/day was lowest in the MC6 (109,5 g/day) and highest in the MC0 (114,2 g/day). There were no significant differences among egg quality parameters, but egg yolk index and proportion, yolk color were improved in higher MC level diets. The Trafish by-product fat increased culling body weight (1,98-2,02 kg/hen) compared with the control (1,96 kg/hen). It may be concluded that the supplementation of Trafish by-product fat in the laying hen diets at 2 to 4% improved egg weight and quality. Moreover, the culling body weight of laying hens in MC supplemented diets was more suitable to the demand of buyer for slaughter.

This study aimed to compare the morphological characteristics and the sequence of cytochrome C oxidase subutnit I (COI) gene of two goby species Butis butis and Butis humeralis to verify their species identification. Morphological results show that they are similar in body shape, snout, color and texture of the pectoral fin muscles and some measurable parameters. However, they differ in the spots and the color of their eyes, the starting position of dorsal and anal fins, the ratio of head length/distance of two eyes and body depth/caudal fin depth. COI gene sequences of all samples of the two species are highly identical at 99-100%. Genetic distance between two species (0.003 ± 0.001) is equivalent to that within species. Thus, the two goby groups are the same species. This species is different from B. butis species reported in GenBank (COI gene sequence with 86% identity), indicating that the classification of B. butis species in the world is still unclear and needs to be further studied.         

This study analyzedthe technical efficiency for commercial white shrimp ponds in 248 households from Ninh Hoa town, Khanh Hoa province by Data Envelopment Analysis (DEA) method followed the minimizing input oriented and Stochastic Production Frontier (SPF) model. The results indicated that technical efficiency score of the whiteleg shrimp farmsusing SPF method varied from 0.1764 to 0.9504 with an average value of 0.6867. By DEA_VRS method, the technical efficiency score ranged from 0.001 to 1.000 with an average value of 0.7192.Labor, breeding and other variable costs also affected production, therefore farmers need to use these factors properly in shrimp farming.This is a positive sign to find out solutions and sustainable development for white shrimp farming in Ninh Hoa town, Khanh Hoa province.   

A study was carried out to evaluate effect of using Trichanthera gigantea leaf meal in the diets for Luong Phuong chicken. 240 Luong Phuong chicken (57,25 ± 5,06g in weight) were  completely randomized on four treatments corresponding to four Trichanthera gigantea leaf meal levels on basal diet: 0% (TG0), 5% (TG5), 7% (TG7), 10% (TG10) in basal diet and three replications per treatment. The results showed that chicken weight gain, FCR were significant differences (P< 0,05) between diets. Some targets such as carcass, thigh and brest percentages had non difference among treatment, tended to decrease with according with increasing of T.gigantea leaf meal levels in diets. Replacing T.gigantea leaf on basal diet of Luong Phuong chicken in 5% level gave good growth performance.

Six exported rice cultivars were studied employing 15 RAPD primers, in which 13 revealed polymorphism, 1 (Sn06) was monomorphic and the rest (OPW19) failed to show reaction. Of 73 reproducible bands amplified, 64 (57.67%) were polymorphic, ranging from 2 to 11 fragments with an average of 5.21 bands per primer. Six out of 13 primers amplified a high number of reproducible bands as well as exhibited over 70% of polymorphic level. PCR results with 4 specific primers EAP, ESP, INSP, IFAP using templates obtained from the 6 rice varieties helped to confirm the ability of RAPD primers to differentiate between the rice varieties. The results showed the applicability of the RAPD and SSR markers in the locus analysis related to the fragrant characteristics of the rice varieties.

This study aimed to isolate and select lactic acid bacteria prossessing good fermentation capacity and to apply in spirulina-supplemented yogurt fermentation. Results showed that 22 strains were isolated from yogurt samples. Besides, bacterial cells whose colonies were round, convex and white colored were immobilized, spherical or rod-shaped, organized in pairs or beads, positive-Gram. In addition, those strains could not perform oxidase and catalase activities. Seven lactic acid bacteria strains (S4, B1, B4, B5, D1, S1, and S2) were initially selected and showed high lactic acid fermentation based on the ability to oxidize lactate on test medium containing bromocresol purple with 1.5 to 1.9 diameter halozones. Experiments testing on milk fermentation supplemented with Spirulina sp. at 41oC in 8 hours indicated that all 7 lactic acid bacteria isolates obtained fermentation capacities to produce lactic acid concentration at 2.97-6.03 g/L and cell density at 10.91-10.98 log CFU/mL. Among those isolates, S2 (produced 6.03 g/L lactic acid concentration and 10.98 log CFU/mL cell density) was the most promising isolate and was molecularly determined to be Lactobacillus plantarum (Accession no. AB510752.1) with 92% similarity.

A study on the mass changes of physical features, proximate composition and fillet yield of four red tilapia groups including 300-400 g, 400-600 g, 600-800 g and larger than 800 g was carried out with the aim to determine the reasonable weight for fillet products. The results of the study showed that, a remarkable difference in physico-chemical parameters among the studied groups was found (p800 g if compared to that of the remained groups. For the fillets of Red Tilapia among the four groups, moisture, protein, lipid and ash content were 76.52-77.83%; 16.81-18.73%; 1.2-1.56%; 1.13-1.21% respectively. In conclusion, the group of 600-800g was the reasonable fish weight for fillet products.

This study was carried out at Hong Dan district - Bac Lieu province. Soil samples were taken at 5 different areas where salinity levels changes occurs in different time of a year. The time chosen to take sample was in April (high salinity) and in October (lower salinity). There were 70 soil samples collected. Water samples were also collected. Results showed that, Mg concentration in both soil and water was higher than Ca concentration. The concentrations of Ca in soil and water were controlled by gypsium, with log(Ca2+)=-2.3. All samples taken in April had very high salt content, the SAR and the ESP were higher than the warning level (SAR should be < 15). In October, salt in water was decreased due to rain and the SAR decreed accordingly, but ESP decreased in some places, but still high in the others. The relationship between SAR and ESP was not stable established as proposed by Gapon (1933) with KG # 0.5. Calculated data showed that an amount of rainfall of 750 mm to reduce ESP to below 15 was really needed.

A population of 400 F3 plants from the cross of Kalarata and Azucena were used to construct a genetic linkage map using 100 microsatellite markers. The map covered 1,405 cM with an average distance of 14.05 cM between loci. The F3 families were phenotyped for salt tolerance in Yoshida nutrient solution with salt stress of 12 dS m-1 using NaCl. A total of 8 QTLs were identified using Composite Interval Mapping with 5 traits studied. The short arm of chromosome 1 had the highest density of QTLs detected for salinity tolerance. The QTLs identified in this study would be useful for further studies through fine mapping, QTL-based gene cloning, and marker-assisted selection for breeding of salt tolerant rice varieties.

Asparagus (Asparagus officinalis L.) is a tasteful, nutritious vegetable that may serve as a food crop as well as an ornamental. The study consists of four experiments which was designed completely randomized and factorial with one factor and four replications. The aim of this research was investigated the optimum concentrations of plant growth regulators for breeding and acclimatizing asparagus. Results showed that:1) at the initial stage, chlorine dioxine 10% in 25 minutes was suitable; 2) at shootting stage on MS medium supplemented with 4.0 mg/l Kinetine formed the highest number of shoots; 3) NAA at a concentration of 3.0 mg/L was found most suitable for rooting of shoots; 4)  rooted plantlets were acclimatized in nethouse with 67.5 - 72.5% survival of transplants.

(10E,12E)-10,12-hexadecadienal, a sex pheromone component of some lepidopterous pests in the Mekong delta, was synthesized by using a synthetic route with 1,10-decanediol as starting material and Wittig reaction as key reaction. Two hydroxyl groups (OH) of 1,10-decanediol were consecutively brominated and protected to form 1-bromo-10-methoxymethoxy-decane which was heated with triphenylphosphine at 90oC for 48 hours and then coupled with (E)-2-hexenal by Wittig reaction to produce a mixture of methoxymethyl ethers (MOM-ether) of (10E,12Z)-10,12-hexadecadien-1-ol and (10E,12E)-10,12-hexadecadien-1-ol (yield calculated from 1,10-decanediol including 4 steps was 12.2%). After removing the MOM protection group, (10E,12E)-10,12-hexadecadien-1-ol compound was separated, and purified by open column chromatography using 15% AgNO3 in silica gel as stationary phase. Oxidation of the formed (10E,12E)-10,12-hexadecadien-1-ol with pyridinium chlorochromate (PCC)reagent gave (10E,12E)-10,12-hexadecadienal compound in 69.3% yield.

The study was conducted in the Biochemistry and Plant Physiology Department, College of Agriculture and Applied Biology, Can Tho University, aiming at to create a new yellow ochna line that satisfies consumer needs with its pretty flowers, long-lasting petals, and flowering in time during the Lunar New Year. By survey of varieties cultivated popularly in the Mekong Delta (2009-2010) two yellow ochna varieties were selected. They are Thu Duc yellow ochna (Mai giao Thu Duc) and long-blooming yellow ochna (Mai vang hoa lau tan) which were used for cross-breeding materials. By the reciprocal breeding method of two hybrid combinations, the male ♂ long-lasting petals yellow ochna x female ♀ Thu Duc yellow ochna and male ♂ Thu Duc yellow ochna x female ♀ long-lasting petals yellow ochna were conducted and data on the diameter of flowers, number of petals, petal shapes and time for petal falling were collected. Results showed that at the F1 generation, every hybrid combination had 12 to 15 seeds which were later planted up to flowering. Among flowering plants two elite hybrid individuals named THLI-9 and THLII-7 have been selected. In criteria of the experiment, the flower diameter and number of petals were affected by cytoplasm, but not for the petal shape.

Objectives of the study were to investigate ammonium distribution in soil and ammonia volatilization by application of nitrogen fertilizer types. Field study was conducted with 4 treatments: (1) urea, (2) urea-nBTPT (n-butyl thiophosphoric triamide), (3) NPK briquette, and (4) NPK IBDU (Isobutylidene diurea) and by 3 replications. Concentration of NH4+ in soil, in flood water and ammonia volatilization loss was investigated at 1, 3, 5, 7 days after N application at fertilization stages. Results showed that concentration of NH4+in flood water and in soil at 0 - 3 mm depth from soil surface was higher in broadcast urea and urea-nBTPT than in NPK briquette and NPK IBDU treatments. Deep placement of NPK briquette and NPK IBDU treatment had higher NH4+-N concentration at 5 cm depth and at 5 - 10 cm away from placement site. N losses by NH3 volatilization during the first 7-day period after three fertilizer applications for urea, urea-nBTPT, NPK briquette and NPK IBDU were 5.94%, 5.82%, 3.77% and 3.14% of the applied N, respectively. Application of NPK briquette and NPK IBDU reduced NH4+in flood water and in soil surface layer, and tented to reduce NH3 loss.

Objectives of this study were (i) to determine the effects of NPK fertilizers in combination with sugarcane filter cake on NPK uptake of ratoon sugarcane; (ii) to evaluate NPK nutrients balance of ratoon sugarcane; (iii) to compare NPK nutrients balance between ratoon sugarcane and plant sugarcane in Hau Giang - alluvial soil. A 22 factorial experiment in a completely randomized block design with four inorganic fertilizer treatments (NPK, NP, NK and PK) and two sugarcane filter cake treatments (10 and 0 tons ha-1) by four replications was conducted in Long My district, Hau Giang province during 2012. Results showed that the sugarcane filter cake application increased NPK uptake in ratoon sugarcane: in the treatment of sugarcane filter cake, the NPK uptake in ratoon sugarcane (236 kg N ha-1, 51 kg P2O5 ha-1 and 373 kg K2O ha-1), were higher than that of without combined sugarcane filter cake (162 kg N ha-1, 37 kg P2O5 ha-1 and 264 kg K2O ha-1). Balance was made inthe treatment of NPKfertilizers combined sugarcane filter cake, the balance values were 13 kg N ha-1, 177 kg P2O5 ha-1, -264 kg K2O ha-1of ratoon sugarcane which were higher than that of NPK balance of plant sugarcane, with balance values of -27kg N ha-1; -64 kg P2O5 ha-1; -423 kg K2O ha-1.

The aim of this study was to investigate the effectiveness of different inoculation approaches in enhancing the biodegradation of the pesticide Propoxur in soil medium. Inoculation was conducted with the Paracoccus sp. P23-7 originally isolated from Propoxur contaminated soil as the key degrader organism. The bacterial strain was applied either via free cells or immobilized on solid municipal waste biochar. Bacterial cell numbers, survival of Paracoccus sp. P23-7 at the end of the experiment as well as Propoxur biodegradation measurement in soil were used to investigate the bioaugmentation efficiency of the different approaches. Soil inoculated with the Paracoccus sp. P23-7 immobilized on biochar from the beginning of the experiment showed the highest Propoxur degradation, whereas the other inoculum approaches showed an increased but lower contaminant biodegradation. Regardless of the inoculum approaches, Paracoccus sp. P23-7 still survived properly in soil medium under the laboratory condition after 14 incubation days. This fact was indicated by a DGGE profile of the soil microbial community in different treatments and the pure culture of Paracoccus sp. P23-7 strain. Thus, our results allow the conclusion that the application of a key bacterial degrader-biochar-complex is the most promising approach for an accelerated biodegradation of organic chemicals in soil medium.

Clay soil is one of the mineral resources commonly distributed throughout the Mekong Delta (MD) province that has been used by local people and companies to produce bricks, tiles, potted plants and other craft products. Production of pea gravel Keramzit was carried out by rapid puffs baked method for kaolinite clay mineral (temperature around 1000 - 12000C) and mixed with coal or ground husk at 3 ratios (30%, 50% and 70%). Results showed that the process of pea gravel production was successfully created; the keramzit product was grown for rapid testing on maize (15 days) and a ratio of 50% mixing fillers was effectively selected. Using 100% pea gravel keramzit (50% fillers) for creating potting medium to grow spinach within 25 days gave the high yield as of 100% organic soil. Results of  experimental growing for five types of ornamental plants including Arecaceae, Dracaena fragrans, Sansevieria trifasciata, Aglaonema oblongifoliu and Japanese ficus on potting medium of 100% pea gravel keramzit (50% fillers) for 60 days showed that all plants grew and developed well on  pea gravel keramzit. Thus, clay soil can be used to produce pea gravel products in the MD for growing vegetables, ornamental flowers, bonsais in order to increase the beauty, green and clean living environment.

The research was conducted in the laboratory and nethouse of the Department of Plant Protection, College of Agriculture and Applied Biology, Can Tho University to screen actinomycetes able to control sheath blight disease caused by Rhizoctoniasolani. Results showed that three actinomyces isolates, CT-ST1b, TO-VL4b and TB-VL2 reduced the mycelial growth of R. solani by the diameter of mycelial growth on PDA medium with 0.0, 6.0 and 10.0 mm, respectively comparing to 90.0 mm in control treatment at 5 days after inoculation. Besides, six isolates of CT-ST1b, TO-VL4b, TB-VL2, CB-TG8, TO-VL11b and BM-VL9 were not able to form sclerotia until 15 days after testing. In net-house condition, these actinomyces isolates, CT-ST1b, TO-VL4b and TB-VL2, were able to limit sheath blight disease. Of which, the treatment of TB-VL2 applied before and 2 days after inoculaton showed the high ability to control the disease and was not different significantly with Validacin 5L treatment at 21 days after testing, such as: the ratio of diseased tillers was 58.4%, reduction in disease incidence was 4.4% and relative length of lesion was 20.7% comapring to 50.8%, 44.7% and 20.4%, respectively, of the Validacin 5L treatment.

The study was carried out to investigate the effect of vitamin E supplement on humoral immune response against Newcastle disease and long - lasting maternal antibody. In the first study, chickens were unvaccinated while in the second study, they were vaccinated Newcastle at 7 day-old and booster at 21 day-old. Chickens in treatment 2 and 3 were supplied with vitamin E at 11mg/bird/day on feeds and drinking water from the day 7. Blood samples were collected at 3, 7, 21 and 30 day-old (Study 1) and 21, 35 and 52 days of age (Study 2) to estimate the maternal antibody and the immune response by HI test. The results showed that maternal antibody was high (12.5) at day 3 of age and decreased rapidly at 7 days of age (5.06) and almost disappeared at day 30 of age. At postvaccination (21 days of age), most chickens had low antibody titer and GMT of 3 treatments were 6.25, 8.16 and 11.39, respectively. At 35 day-old, antibody titer grew up to the protective level with GMT >8. The titer antibody was highest at 52 day-old, with 28, 58 and 88 for treatments 1, 2 and 3, respectively.

The survey was carried out at An Giang, Dong Thap and Tra Vinh provinces from February to April 2014. A total of 78 samples of snake-head fish (39 fingerling samples and 39 growth-out samples) were collected. Fish specimens were observed for clinical signs and examined for parasites. Results showed that there were seven genera of parasites: Trichodina, Epistylis, Apiosoma, Dactylogyrus, Gyrodactylus, Pallisentis and Spinitectus. There were five parasitic genera on the skin and gills and two genera in the intestines. The number of parasites was dependent on parasitic genus and the infected organs. The rate of Trichodina was highest (1-183/10X) and the lowest was Dactylogyrus (1/10X). The composition of parasites on fingerling was more diversity than commercial. Almost fish specimens with some signs such as hemorrhage or sores usually had a great amount of parasites much more than healthy fish specimens.

Nghiên cứu gồm hai thí nghiệm và một đợt nuôi thử nghiệm nhằm đánh giá khả năng nuôi tôm chân trắng theo qui trình semibiofloc tại huyện Đầm Dơi, tỉnh Cà Mau. Thí nghiệm 1 gồm có 4 nghiệm thức (NT): NT1 là NT đối chứng, NT2 sử dụng rỉ đường, NT3 sử dụng bột gạo và NT4 sử dụng bột mì và thí nghiệm 2 gồm có 4 nghiệm thức khác nhau về tỉ lệ carbohydrate bổ sung trong qui trình (NT1 tỉ lệ C/N = 5:1, NT2 là 10:1, NT 3 là 15:1 và NT 4 là 20:1) nhằm tìm ra cơ chất sử dụng hiệu quả và xác định tỷ lệ C : N hợp lý trong qui trình Semibiofloc trong điều kiện ở Đồng bằng sông Cửu Long (ĐBSCL). Kết quả cho thấy sử dụng bột mì với tỉ lệ C:N là 10:1 cho tỉ lệ sống và tăng trưởng của tôm cao, khác biệt có ý nghĩa thống kê, và có hiệu quả về kinh tế, đảm bảo được môi trường thích hợp cho tôm chân trắng phát triển. Trong nuôi thực nghiệm tôm chân trắng tại huyện Đầm Dơi, tỉnh Cà Mau, các yếu tố môi trường biến động trong khoảng cho phép, thích hợp cho sự phát triển của tôm nuôi. Năng suất thu được từ mô hình là 14,308 tấn/ha/vụ, với tỉ lệ sống bình quân là 89,2%; hệ số sử dụng thức ăn thấp (FCR = 1,012) và lợi nhuận thu được là 666 triệu đồng/ha/vụ. Đây là mô hình nuôi hiệu quả có thể nhân rộng ra toàn tỉnh Cà Mau và cả khu vực Đồng bằng sông Cửu Long.

This study was conducted to evaluate the effects of water sources on the growth and survival of juvenile black apple snail (Pila polita). Experiment was arranged with 4 treatments and triplications were run per each treatment as follow: 1). Green water only (GW), 2). Water from fish pond only (PW); 3). GW + feeding and 4). PW + feeding. Snails were reared in plastic tanks (0.5 m2) with the density of 150 ind./tank. After 35 days of rearing period, the survival rate of snails in PW+feeding (92.0%) was similar to the result in GW+feeding (89.1%) or PW (83.1%) but significantly higher than (p

This study was carried out from April 2014 to December 2014 at the three coastal provinces of the Mekong Delta (Tra Vinh, Soc Trang, and Bac Lieu) aiming to analyze technical and financial efficiency of marine capture fisheries by single strawl (>90CV). Data were collected through interviewing 162 vessels of two groups: fishermen have participated in cooperative groups and fishermen have not participated in. The empirical results indicated that the average yield of cooperative group was 327.7 kg/CV/year with the costs of 6.48 million VND/CV/year and bringing profit around 1.69 million VND/CV/year. Other group obtained 276.7 kg/CV/year of yield, 6.09 million VND/CV/year of the costs and 1.04 million VND of the profit. The level efficiency of revennue of single strawl was 67% of cooperative group, was lower than the free group (76%).

In this study, gelatin has been successfully extracted from skin of catfish according to the new method to solve the environmental pollution by seafood waste during fish processing. Catfish skin was soaking in NaOH and CH3COOH at various concentrations to remove the noncollagenous protein and demineralization, respectively. Gelatin was extracted at various temperatures in different times. Result shows that catfish skin soaked with 0,1M NaOH for 30 minutes and 0,07M CH3COOH for 3 h to remove 11.9% the noncollagenous protein and 47.5% mineral of skin. Fish skin sample extracted in distilled water at 80oC for 0.5h, showed the highest of viscosity (2.04 mPas) and extracted yield (5.57%). Optimum condition for drying gelatin sample is 37oC for 24 h. Gelatin samples extracted from catfish skin has gel strength (157.4 g) higher than 1.5 times when compared with commercial gelatin (from China) (107.2 g). Viscosity of catfish skin gelatin (3.34 mPas) is also higher than commercial gelatin (1.88 mPas).

Studying on climbing perch culture system in Hau Giang province was conducted from March to December 2013 through interviewing 45 households culturing climbing perch to evaluate the technical and economic aspects and to identify advantages and disadvantages of climbing perches farming system. Results showed that the area of climbing perch cultured pond was not large (0.14 ha/pond). Fingerlings were stocked from March to May. After 4 months of culture, climbing perch were harvested with high survival rate of 80.5%, average yield of 84.7 tons/ha/crop, body weight of 7.42 individuals/kg, and feed conversion ratio (FCR) of 1.46. In addition, with production cost of 1,834 million VND/ha/crop, gross income of 1,796 million VND/ha/crop, farmers were lost 37.4 million VND/ha/crop. There were 54.8% of farmers to be lost from this culture system. Some major difficulties were found from this system such as low price and high cost.

The status of fishing in the flood season in the Mekong Delta was studied from August to Decemeber 2014 in the upstream (An Giang and Dong Thap provinces) and mid-stream (Can Tho and Vinh Long provinces). The survey was conducted on 160 households, also weekly sampling was done on gill net and long fence trap net to identify species composition, size and regression between yield and various flood levels on the fishing gears. Results showed that water level in the upstream and mid-stream of the rice field was 40-120 cm and 30-60 cm, respectively. This study identified 65 and 40 species in the upstream and mid-stream. Gill net, long fence trap net and barrier net predominated in the fishing gears, the fishes were caught in small size compare to the maximum size of each species, fishing efforts are increasing, the illegal fishing gears are developing and mesh size of the net is gradually smaller in all fishing gears. Aquatic resources was declined about 50-70% comparing to 10 years ago, because of pesticide utilization, less flood in recently years, dykes construction to prevent flood for agriculture development, it caused negative impacts to aquatic resource. There were less regression between yield and various flood levels.

Study on Channa lucius at 4-30 days after hatching rearing in tank system with different diets was conducted from April to May 2012 in College of Aquaculture and Fisheries, Can Tho University, Vietnam. The experiment included four treatments of feed types (i) the treatment which fed pelleted feed from the 16th day; (ii) the treatment which fed pelleted feed from the 13th day (iii) the treatment which fed pelleted feed from the 10th day and (iv) the treatment which fed pelleted from feed the 7th day. Fish with initial size of 0.87 cm in length and 0.002 g in weight were stocked at the density of 2 fish/L. After nursing 30 days, the results showed that temperature, pH, nitrite in all treatments were in normal ranges for fish growth. The fish in all treatments reached total length and body weight of 2.56-3.0 cm (0.057-0.071 cm/day, 3.6-4.12%/day) and 0.19-0.27g (0.0063-0.0089 g/day; 15.17-16.35%/day) respectively. The treatment which fed pelleted feed from the 16th day gave the highest growth rate and significantly different from to the treatment which fed pelleted feed from the 10th day (p

The objective of this study was to detect the presence of class 1 integrons in A. hydrophila that caused haemorrhagic disease on striped catfish (Pangasianodon hypophthalmus) in the Mekong Delta. A total of 40 A. hydrophila isolates were collected from 2013 to 2014. These isolates were screened against 15 antimicrobial agents by disk diffusion method. The results showed that 80% A. hydrophila isolates displayed multiple resistant phenotypes. Thirty - two A. hydrophila isolates were chosen to determine the presence of class 1 integrons by PCR (Polymerase chain reaction). The results indicated the percentage of class 1 integrons in A. hydrophila isolates were 21,9%. The presence of the mobile genetic elements (class 1 integrons) in A. hydrophila in this research showed the ability that bacteria can transfer antimicrobial resistance genes to other bacteria in the aquatic environment. Therefore, using antibiotics for disease prevention in aquaculture should be managed more strictly.

This study was carried out from January to December 2012 through random interviewing 6 producing companies of Tiger shrimp seed, 16 nursing households, 24 feed and chemical gents, 91 farms, 12 collector and 9 processing companies in Kien Giang, Soc Trang and Ben Tre province. The results of study shown that linkage of intensive shrimp (Penaeus monodon) farming models was low and only exchanged information (technique, market). Suppliers (breed, feed, chemical) and buyers (colllectors and processors) associated with farming models through supplying and buying with market price. The average area of houseshold (1.36 ha/household) was the smallest in the farming models (29.04-45.28 ha), pond area of farming models (0.45-0.59 ha/pond) were not significant but depth water of farm enterprenuers was highest (1.52 m). Stocking density of companies (26.88 ind./m2) was lower than that in houseshold, farm enterprenuers and cooperative i.e 33.12, 31.57 and 36.25 ind./m2, survival rate and yield of farm enterprenuers and companies were highest: 70.57%, 6.52 tons/ha/crop and 74.5%, 6 tons/ha/crop, respectively. Total production cost was 346.9-391.8 million VND/ha/crop, production cost of houseshold was highest (72.2 thousand VND/kg). Benefit and cost benefit ratio were highest in farm enterprenuers (374.7 million VND/ha/crop, 50.8%) and companies (346.8 million VND/ha/crop, 56.7%). However the lowest profitable rate was in the household. The result of study showed that houseshold is highest risk and less sustainable than other models.

Black pomfret (Parastromateus niger) is marine fish that has deliciousmeatandfishmarket sizelargewithhigh economicvalue. A study on maturation developing characteristicsof black pomfret was conducted from March, 2014 to January, 2015 in the coastal areas of Soc Trang-Ca Mau provinces. Results of the study showed that the condition factors (CF) of fish revealed lowest values from May to September (0.0272±0.0006) and those of highest in October (0.0282±0.0001). Highest values of the gonadsomatic index (GSI) of fish was observed in August (female: 4.68%; male: 1.29%) and those of lowest values in April (female: 1.52%; male: 0.59%). Analysis of seasonal distribution of maturity stages for one year revealed the presence of ripe/running males and females from June to October with highest values in August (female: 64%; male: 82%), thus confirming the spawning periodicity revealed through the analysis of fluctuations in the GSI and CF. The absolute fecundity of black pomfretranged from 21,756to 1,784.151eggs and the relative fecundity 629 eggs/g of female fish, in which the body weight of female fish ranged from 237.52 to 1,491.00 g/individual. Low correlations were found between absolute fecundity and body weight (r=0.51).

The objective of the study was to explore the factors affecting the level of satisfaction of students in the Mekong Delta (MD) on services (referred as educational services) provided by universities. A convenient sample of 659 students studying at six universities (stratified sampling) in the Mekong Delta was used. The analysis shows that the satisfaction of students is positively affected by the factors including: (1) the school’s image, (2) service quality, and (3) price perceived. Finally, some implications are proposed to improve the level of student satisfaction as well as suggestions for further study.

This research analyzes factors’ influence, especially the product quantity affects the capital (particularly fixed assets, machinery and other equipment) by using demand function – Nerlove’s partial adjusment model. The results of this model illustrates the partial adjustment mechanism of quantity variables with the value of 0.7113. This is clear that the information was not rapidly updated in order to plan investment projects of enterprises and this consequently influence to the effectiveness of fixed assets’ investment. The effects of quantity’ factors on  investment decision are lower than those in long term and it takes a time of 2.5 years to illustrate clearly such influences. In addition, the enterprises’ revenue and operation time positively affect fixed assets’ investment; on the contrary, the debt rate and profit of previous year have negative effects. Moreover, there is a trade off between fixed assets’ investment and the number of labours.

Research on customer satisfaction in the service sector is abundant but understanding customer satisfaction in banking sector remains limited. In this study, the SERQUAL model for service and Logit model with control variables were used to determine factors affecting customer satisfaction for savings services of Agribank in Vinh Long province. Data were collected through a survey of 130 customers who have savings accounts at the branch. The results showed that the four key factors affecting customer satisfaction include responsiveness, tangibility, service capacity, and assurance. Besides those, the control variable – customer’s age – negatively affects the level of customer satisfaction. Therefore, while banks have to encourage their employees to pay attention on individual customer’s age as well as to improve savings services through the four factors defined to enhance the level of customer satisfaction.

The aim of this paper is to investigate the impact of institutional distance on enterprise’s export in Vietnam. Building upon transaction cost theory of Hennart (1991), this study hypothesizes that institutional distance between Vietnam and import countries is negatively related to Vietnam enterprises’ export intensity. To test the proposed hypothesis, the survey data of Viet Nam Statistics Office at 175 export firms and Tobit regression are used. The empirical finding revealed that the hypothesis is strongly supported with controlling characteristics of firm. The study also provides managerial implications.

This study is aimed to identify factors affecting business initiative intentions of economic graduates in Can Tho city. Data were collected from 180 economic graduates who live in Can Tho city and have never started up a business. With the methods of exploratory factor analysis and binary logistic analysis, the findings are the six factors including (1) motivation to become an entrepreneur, (2) family background, (3) government and local policies, (4) entrepreneurial traits, (5) finance, and (6) personal characteristics, respectively. Some suggestions to enhance business initiatives of the graduates were porposed, including particularly those on education progam and policies.

Tien Giang is the second leading province in mangoes production (following Dong Thap) in the Mekong Delta. Tien Giang mangoes, especially Hoa Loc mango has both comparative and competitive advantages in price and quality compared to other mangoes. However, there are many limitations regarding awareness of chain actors, linkages of production and distribution as well as the support from local governments at all levels to increase mangoes quantity and quality. The study was based on thevalue chainapproachofKaplinsky&Morris(2001), theValueLinks method ofGTZ(2007), Making value chains work better for the poor(M4P, 2008) and participation of chain actors. The research objectives are (1) analysis of mangoes market, (2) assessment of mangoes production and distribution situations in Tien Giang, (3) analysis of mangoes value chain, and (4) Suggestion of strategic solutions for upgrading mango value chain that help facilitators at all levels to develop further policies and better measures to added value of mango product.

Bac Lieu with many attractive tourist destinations is attracting a large number of domestic and foreign tourists. Particularly, in recent years, the province's cultural tourism has prospered with new destinations built to meet the demand to learn, discover the culture, history, and people of Bac Lieu. However, the quality of service at cultural destinations is inadequate and needed to improve in the coming time. Aming to do that this study was conducted with direct interviews of 100 tourists at the cultural destinations in the province. Through the method of testing the reliability of the scale by coefficient Cronbach's Alpha and factor analysis EFA, the results showed that factors of the cultural destinations need to be considered including: professionalism, impressiveness, attitude of service and safety, cultural knowledge, employee uniforms. Matrix IPA also be analyzed to provide a basis for strategic solutions to improve the quality of service at cultural tourism destinations of Bac Lieu in particular and tourism in general.

Working is currently a hot issue. It is much concerned not only on mass media and by agencies and enterprises but also by a lot of students even those sitting on the bench. Students have made much effort in gaining knowledge and experiences in order to get a proper job after graduation. Based on the directly surveyed data of 400 students in the faculties at the Can Tho University and Probit models, this article is aimed to define the factors affecting the decision to get part-time job of Can Tho University students. The results showed that the income of the student, schools years and life experience are statistically positively influence on decision to get part-time job of Can Tho University students.

The study was conducted to analyze the pineapple value chain of poor farm households in Tien Giang province. Research data were collected from 207 observations involved in the pineapple value chain. Research results indicate that the pineapple value chain of poor farm households in Tien Giang province are operated primarily through four main channels, including the major actors: poor farmers, traders, fruit granaries, businesses, retailers and wholesalers. The poor farm households are those who generate the highest value added in the pineapple value chain, followed by wholesalers in level 2 and businesses. The value added and net value added generated from the pineapple products strongly impact to the changes in income of poor pineapples planting households. The distribution of value added and net value added positively affected to incomes of those households in Tien Giang province.

Education and training is the key issue which has aroused concern of the whole society, especially as increasingwhen the demand for highly skilled workers is increasing. Being a part of the public participation and tuition-fees increasing schemes of Vietnam Ministry of Education and Training, the credit support program for students iwas adjusted again by the government, aiming towith the goal of “non any dropping-out students”not letting any students drop out. This study used stratification sampling method to survey 282 students borrowing loans. Comparable statistical method and linear regression models were selectused to explore factors affecting students’the need for credit of students. Thus, four solutions including increasing the loan amount, diversifying borrowers, increasing frequency of disbursement and ensuring loan funds awere proposed to enhance the capacity to meetsatisfy the need for credit of students in public colleges in Can Tho.

Vocational training for rural labors have been concerned and implemented by leaders at all levels and in Can Tho city in particular. This is the basic social policy addressing employment and effective use of human resources aimed to social stability and economic development of the localities. In Can Tho city, however, young employees (ageg of 15-29) working mainly in industrial sector and older labors (aged of 40 and over) working largely in agricultural sector have not yet meet the requirements on education, job qualifications and skills. Data from direct interviews of 480 rural households in the districts of Vinh Thanh, Thoi Lai, Co Do and Phong Dien were analyzed using descriptive statistical tools, binary Logistic model to evaluate the factors affecting the participation in vocational training of rural labors in Can Tho city. The results showed that several factors (including education level, profit and ability to respond to non-agricultural jobs of employees) have a direct impact on participation in rural vocational training and employment for rural labors.

Surrogacy is a first time recorded provision in the Law of Marriage and Family in 2014 which took effect from 01/01/2015 (hereunder referred to as the Law). This is a humane provision because it helped legally the infertile and childless couples by using assisted reproductive methods. Surrogacy is a complex matter which exists many destabilizing factors in family and society lives. However, the contents of the Law were prescribed generally which made some provisions different interpretations. Therefore, this article focused on clarifying some provisions regarding surrogacy in the Lawand showing as well some unreasonable points. Then, some improving solutions were proposed to meet the needs of the Law’s practical application.