Published: 31-10-2024
Full Issue
Engineering Technology
Colour adsorption capability of various clays on hot pressed oil from muskmelon seeds
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In this study, hot-pressed cantaloupe seed oil at 110°C was decolored by adsorption method using natural adsorbents, such as bentonite clay from Kien Khe–Ha Nam and Truc Thon white clay from Hai Duong. Bentonite clay and white clay were pretreated into four types: bentonite, refined bentonite, white clay and ball milled white clay. The color adsorption capacity of the clay samples was analyzed based on the UV-Vis photoabsorption method, showing that the pigments in cantaloupe seed oil absorbed light in both wavelength ranges of 300-350 and 400-500 nm. The color adsorption capacity of bentonite and refined bentonite is higher compared to that of other clays, resulting in seed oil with a much lighter color after adsorption. The adsorption by bentonite reached an efficiency of 27.75% at 315 nm, 77.21% at 450 nm and refined bentonite reached 17.22% at 315 nm, 92.53% at 450 nm when adsorbed at optimum conditions of adsorption time and adsorbent mass.
Application of BIM and GIS integration model for management, exploitation, operation, and maintenance of infrastructure project - Case study: Tan Cang Station, Metro line 1: Ben Thanh - Suoi Tien
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This study presents some applications of the Building Information Modeling (BIM) and Geographic Information System (GIS) integration model. From the literature review, three main types of BIM and GIS integration models are pointed out: BIM lead - GIS support, GIS lead - BIM support, and BIM and GIS equally role and are merged by a third platform. Thereby, the characteristics and features of each type are evaluated. Then, the BIM and GIS integration model is conducted under the third type for the case study of Tan Cang Station, on metro line 1: Ben Thanh-Suoi Tien. The observation showed that the BIM and GIS integration model is a useful tool to help project stakeholders deliver optimized decisions for management, exploitation, operation, and maintenance of the project and gradually implement sustainable development.
Analysis of aerodynamic characteristics of sports car equipped with rear spoiler
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This article presents research on the effects of rear spoilers on the aerodynamic characteristics of sports cars. The simulation uses Solidworks to design the original car model, and the car with the rear spoiler is applied to the Flow Simulation module to analyze the model's aerodynamic characteristics. The results showed that the lift coefficient decreased by 11.2%, the drag coefficient decreased by 5.05%, and the vortex area behind the rear of the vehicle tended to fade away, reducing the vehicle's restraint. These values are expressed through the pressure and velocity distributions around the model. Therefore, it is proposed that a rear spoiler be added to sports cars to help stabilize them when running at high speed.
Application of digital twin technology in smart grid development for Ho Chi Minh City's power grid
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A digital twin (DT), usually referred to as digital twin technology (DTT), is a replica of an actual object made digitally. Data streams gathered from sensors attached to the original object were used to produce this duplicate. This technology has been thoroughly studied in numerous nations across the world. It is widely used in manufacturing, including for process optimization, quality control on production lines, supply chain management, preventive maintenance, and customer experience research. However, the idea of the digital twin is still not very common in Vietnam, particularly when it comes to the automation of the power distribution grid (DG). The qualities of DTT that must be included for creating a smart grid (SG) for DG are discussed in this study. To fulfil the growing need for power grid development, the paper also discusses the infrastructural constraints in Ho Chi Minh City while creating a smart power grid based on DTT.
Synthesis of high-quality, large-area single-layered graphene using low-pressure chemical vapor deposition on copper plate surfaces
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In this work, the low-pressure chemical vapor deposition (LP-CVD) method was used to fabricate high-quality single-layered graphene with a large area on the surface of a copper plate. The development pace and quality of graphene were significantly influenced by temperature and the CH4:H2 ratio. The optimal monolayer graphene was produced at around 1000oC with a growth period of 120 minutes and a CH4:H2 ratio of 35:6 sccm. The total pressure in the chamber varied from 1,0 to 1,2 Torr. A narrow full width at half maximum (FWHM) value of 2D peak (~ 63,43 cm-1) and high Raman peak ratios I2D/IG (~ 3,10) confirmed the single-layered graphene. The negligible imperfections and great homogeneity of the graphene were confirmed by the minute Raman D peaks. Many scientists have considered these temperature and pressure parameters to be optimal for synthesizing high-quality graphene, which promises to open up new applications in the fields of photonics, electrochemistry, electronics, and toxic gas sensors.
Information Technology
The problem of data imbalances and some methods of processing imbalanced data in deep learning models
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In this article, we address the problem of data imbalance, a common phenomenon in binary classification problems, where the sample number of one class is significantly smaller than the other. We compared and evaluated multiple approaches to processing imbalances in deep learning, using the Cat-Dog dataset to study the impact of imbalances on the classification process. The solutions compared include improvements from three approaches: Data, Model and Loss, aimed at enhancing the predictive performance of machine learning algorithms. We also recommend the Model approach by applying Transfer Learning with the Resnet-18 model, which was pre-trained on the ImageNet dataset, giving an F1-score of 95.19% and an accuracy of 95.20% after only 10 epochs. This showed superior efficacy compared to previous studies focused on improving data and loss.
Evaluating effective filtering algorithms in big data processing
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Handling and analyzing data quickly and efficiently in the era of big data is a significant challenge. Filtering algorithms enhance the performance of big data processing by eliminating irrelevant data, reducing computational costs, and shortening query processing times. This study evaluates the performance of five popular filtering algorithms: Bloom Filter, Cuckoo Filter, Quotient Filter, Morton Filter, and Vacuum Filter in an Apache Spark environment. Through experiments on large datasets, the results show that the Quotient Filter is the most efficient in terms of storage, the Cuckoo Filter demonstrates a good balance between insertion, search, and deletion speeds. The Bloom Filter is suitable for static data, the Morton Filter excels in search speed, and the Vacuum Filter has a slow insertion time but fast search and deletion times. Integrating these algorithms with Apache Spark significantly improves processing performance thanks to its distributed and parallel capabilities. The study results provide guidance on selecting suitable filtering algorithms and highlight the potential for effectively applying filtering algorithms in large-scale data processing.
Environment
Study on the removal of nutrients and organic matter in surface water by aquatic plants
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In this study, individual and combined cultivation experiments of three aquatic plants, including Microsorum Pteropus “Narrow” (AQ1), Cyperus Haspan L (AQ2), and Salvinia Cucullata (AQ3), in different water samples collected from landscape lakes (District 7, Ho Chi Minh City), were conducted. Results showed that the highest removal efficiencies of nutrients and organic matter were obtained in the case of AQ2, which AQ1, and AQ3 followed. The combined cultivation ratio between AQ1 and AQ2 of 1:2 (% w.t.) was also determined as the most appropriate design since relatively similar removal efficiencies were found in both water samples: BOD5 (29,78%), TN (66,66%), TP (91,67%), Coliform (64,86%) with internal landscape lake (TDT) and BOD5 (32,08%), TN (60%), TP (92,85%), Coliform (16,67%) with external landscape lake (HBN).
Natural Sciences
Preparation, characterization and CO2 capture application of zeolite pellet without binder
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To solve the problem of pelletizing zeolite without using a binder because it can reduce porosity, an experiment was conducted to pelletize zeolite from a mixture of zeolite X and metakaolin in an alkaline environment followed by hydrothermal treatment. Scanning electron microscopy (SEM) was used to observe the morphological structure of the material, along with X-ray diffraction (XRD) to confirm the crystalline structure conversion of metakaolin and zeolite X. Different types of zeolites were detected in zeolite pellet samples after hydrothermal treatment. A decrease in mechanical strength was noted when studying the force-time curve of the material, which indicates the formation of a porous structure with more adsorption sites besides the enhancement of hydrophobicity. In line with this, CO2 adsorption measurements showed that the adsorption capacity increased after hydrothermal treatment.
Animal and Veterinary
Prevalence of some pathogenic and antibiotic resistance genes of Escherichia coli Isolated from Pig Slaughterhouses in An Giang province
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By PCR method, in a total of 52 Escherichia coli strains isolated from pork and the environment, genes stx2 (42.30%) and eae (17.31%) were detected at a high rate, but genes stx1 and hlyA were not found. Moreover, only genes encoding adhesion factors F18 (5.77%) and F41 (1.92%) were determined, but F4 and F5 were not found. E. coli strains examined for antimicrobial susceptibility showed that these strains were highly resistant to ampicillin (92.31%), amoxicillin/clavulanic acid (86.54%), streptomycin (82.69%), and colistin (44.23%). There were 90.38% of E. coli strains resistant to 2 to 6 tested antibiotic types, and the pattern of Am + Sm (21.15%) was the most common. The results of PCR analysis showed that the genes blaTEM (92.30%) and aadA1 (48.07%) accounted for a high proportion. 96.15% of E. coli strains harbored from 1 to 3 antibiotic resistance genes, and the pattern of blaTEM + aadA1 was commonly recorded in strains from pork and the environment. Therefore, it is necessary to control contamination with antibiotic-resistance E. coli strains in slaughterhouses to protect public health.
Contamination and antimicrobial susceptibility of Staphylococcus aureus isolated from pig slaughterhouses in An Giang province
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A total of 252 pork and environmental samples were collected at slaughterhouses, the contamination of Staphylococcus aureus was recorded at 16.67% on pork samples and 39.06% on environmental samples. The prevalence of S. aureus on pork and the environment samples between small-scale and centralized slaughterhouses were not statistically different. The average contamination density of S. aureus on pork was 7x101CFU/g at small-scale slaughterhouses and 3x101CFU/g at centralized slaughterhouses. The isolated S. aureus were examined for antimicrobial susceptibility. The results showed that they were sensitive to several examined antibiotics but were highly resistant to colistin (73.68%), ceftazidime (57.89%), and tetracycline (52.63%). There was the presence of a number of antibiotic resistance genes in the collected S. aureus strains, of which the tetA gene accounted for the highest proportion (26.58%). The study results showed a high prevalence of S. aureus resistant to antibiotics in slaughterhouses, which has been a risk to consumer health.
Biotechnology
Evaluate the effects of BIDI-AGRI and BIDI-AQUA probiotics addition on commercial whiteleg shrimp farming
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Whiteleg shrimp (Litopenaeus vannamei) farming is a major economic sector in many countries worldwide. Infectious diseases and environmental pollution in shrimp ponds have resulted in significant economic losses for the aquaculture industry. This study presented the effects of a BIDI-AGRI and BIDI-AQUA probiotic blend consisting of Bacillus subtilis, Bacillus tequilensis, Bacillus amilolyquefaciens, Bacillus licheniformis, Lactobacillus acidophilus, Saccharomyces cerevisiae in shrimp cultured water treatment and shrimp growth. The BIDI-AGRI and BIDI-AQUA were applied in three commercial whiteleg shrimp ponds with surface areas ranging from 700 to 1200 m² for 90 days. Results showed that compared to the control, BIDI-AGRI and BIDI-AQUA improved several water quality parameters, including H₂S, NH₃, and COD concentrations, controlled Vibrio spp. populations within acceptable limits and enhanced shrimp immunity. Furthermore, shrimp ponds treated with BIDI-AGRI and BIDI-AQUA exhibited higher growth rates and yields. Due to lower investment costs and higher revenue, shrimp ponds using BIDI-AGRI and BIDI-AQUA achieved approximately 1.6 times higher profits compared to ponds using commercially available probiotics.
Food Technology
Research on the extraction of hydrolysate protein from tilapia fish skin gelatin (Oreochromis niloticus) by using Thermoase GL30 enzyme
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Research on the extraction of protein hydrolysate from tilapia fish skin gelatin was investigated to determine the production process for the gelatin hydrolysis by Thermoase GL30 enzyme to obtain the highest quality of protein hydrolysate. Gelatin powder was hydrolyzed with 0.3% Thermoase GL30 enzyme at 60oC for 1 hour to collect the protein hydrolysate products with viscosity, recovery yield, and color were 16.8 mPa.s; 96.4% and L*= 93.1, respectively. The protein hydrolysate from tilapia fish skin had hydrophobic amino acid of 596 residue/1.000 residues and showed a correlation with the highest antioxidant activity (DPPH) 73.2%. Besides, FTIR spectra showed a close relationship between wavelength numbers in the amide I and amide III regions, especially the stability of the triple helix structure. The results showed that tilapia fish skin could be used to produce high quality hydrolyzed protein.
Effect of hydrolysis conditions on the quality attributes of fermented beverage from the rags of jackfruit (Artocarpus heterophyllus L.)
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This study used jackfruit rags to make the value product like fermented beverages. The objective of this study was to optimise the hydrolysis conditions to process fermented beverage from the rags of jackfruit in terms of analyzing total phenolic, total flavonoids, ethanol content, DPPH scavenging activity and colour of product. Box-Behnken design was applied in order to determine the optimal hydrolysis parameters, including the ratio of water to jackfruit rags (1.5; 2.0 and 2.5 times, v/w), pectinase enzyme concentration (0, 0.1 and 0.2% w/v) and hydrolysis time (10; 65; 120 minutes). The results showed that the optimal condition for fermented beverage from jackfruit rags obtained: a ratio of water to jackfruit rags of 1.9 times, 0.1% concentration of pectinase enzyme and hydrolysis time of 65 minutes, the ethanol content in the jackfruit rags was approximately 4.9% (v/v), the content of biologically active compounds such as polyphenols, flavonoids and DPPH free radical scavenging capacity were 0.511 mgGAE/mL, 0.022 mgQE/mL and 14.54%, respectively. These results suggest that the jackfruit rags are potential raw materials for the processing of fermented beverages with a high value of bioactive compounds.
Agriculture
Evaluation of salt-tolerance of three BC3F4 soybean backcrossing lines in net house conditions
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The study aimed to evaluate the growth performance and yield of three BC3F4 soybean backcrossing lines under artificial saline water irrigation with 120 mM NaCl. The experiment was arranged in a two-factor factorial completely randomized design with three repetitions, including (A) three soybean backcrossing lines 1500, 1600-1 and 1600-2 and three parental lines MTĐ 176, MTĐ 878-2 (salt-sensitive) and NIL72-T (salt-tolerant); (B) two NaCl concentrations of 0 (control) and 120 mM. Salinity significantly reduced the growth and seed yield of three soybean backcrossing lines, but it also increased proline content and electrolyte leakage rate. The salt tolerance index of the soybean lines in descending order was 1600-1 (68.2%) > 1600-2 (36.3%) > 1500 (27.9%). Taken together, line 1600-1 is a promising salt-tolerant line that needs to be further characterized to confirm its tolerance to salinity.
Measuring impacts of Forest Stewardship Council (FSC) application on the economic efficiency of forest plantation in Viet Nam
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This study aims to identify the impacts of Forest Stewardship Council (FSC) application on the economic efficiency of afforestation households in four districts Yen Son of Tuyen Quang province, Luong Son of Hoa Binh province, Thach Thanh of Thanh Hoa province, and Ba To of Quang Ngai province. The data for this study was collected from 346 households of which 173 households have applied FSC for their forest plantation, while other 173 households are non- FSC. The result from the propensity score matching showed that age, education, family size, area of forest land and forest plantation significantly relate to the probability of FSC application. FSC households have higher annual incomes than non FSC households. Moreover, the findings show that although FSC households have higher production cost per hectare than non FSC households, they have higher economic efficiency due to the higher productivity and selling price of FSC timber.
Aquaculture and Fisheries
Species composition and fishing status of mantis shrimp (Squillidae) in the coastal areas of Dong Hai district, Bac Lieu province
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This study aimed to identify the species composition and fishing status of the mantis shrimp in the coastal areas of Dong Hai district, Bac Lieu province. The study was implemented from May 2023 to February 2024. Sampling was conducted twice per month using various fishing gear, including trawl-nets, bag-nets, and barrier-nets. The specimens were measured by weight (g), and total length (mm) and photographed with magnifications of 6 to over 50 times for species identification. Additionally, 30 fishermen were also surveyed to determine the fishing status of mantis shrimp. The results indicated that 7 mantis shrimp species were identified, including 2 large-sized species (Harpiosquilla harpax and H. raphidea) and 5 small to medium sized species (Miyakea nepa, Erugosquilla woodmasoni, Oratosquillina interrupta, Cloridopsis scorpio, and Alima orientalis). The shrimp are caught year-round. Large sized individuals are mostly caught by trawl-nets offshore, as well as by bag-nets, whereas barrier-nets and bag-nets catch small sized individuals. The number of mantis shrimp in populations are gradually decreasing yearly due to pollution and overfishing. The price of mantis shrimp depends on their size, and the cost of live individuals is also higher than the frozen ones of the same size.
The survey of bacterial pathogens on hemorrhagic intestinal diseased snakehead fish (Channa striata) raised commercially in Dong Thap
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This study was to determine the pathogen of bacteria that causes hemorrhagic intestinal disease in snakehead fish (C. striata) and to provide information for effective diagnosis, prevention, and treatment of the disease. A total of 250 samples were collected in Dong Thap province, from December, 2022 to May, 2023. There were 200 diseased fish samples and 50 healthy fish samples, in which diseased fish samples had an average weight of about 226.5g and an average length of about 22.8cm. Snakehead fish with the intestine hemorrhagic disease had typically pathological signs of pale color, scattered spot hemorrhage on the body skin; the intestine were hemorrhagic, which had turned pink or red. The results of isolation, identification of bacteria and experimental infections showed that the causative agent of intestine hemorrhagic disease in snakehead fish was Aeromonas veronii. The experimental infections recorded that the median lethal dosage (LD50) of the two bacterial strains AV9 and AV39 were 4.82×105 CFU/mL and 8.36×105 CFU/mL, respectively.
Research on the current status of gillnets in Soc Trang province
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Research on the current fishing status of the gillnets was carried out from August 2022 to April 2023 in coastal districts of Soc Trang province to analyze the technical, and financial aspects and advantages and disadvantages. There were 55 gillnet fishing households interviewed about the fishing boats, fishing grounds, fishing seasons, main species, catch output, financial efficiency and advantages and disadvantages. The results showed that the gillnet was being developed in Soc Trang province. This profession was exploited all year round. The average fishing production was 26.5 tons/vessel/year, and had a low trash fish rate (4.2%). Fuel and labor costs account for a large proportion of the total trip cost. The profit margin was lower than in previous years, only 0.26 times. The main difficulties of the gillnet fishery are competition for fishing grounds, reduced catch output and high fishing costs.
Education
Understanding the current status of communication competence and critical thinking of physics student teachers at Can Tho University
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The study surveyed 125 students majoring in Physics Teacher Education in courses 46, 47 and 48 to find out the current status of students' communication abilities and opinions on measures to develop these groups of competencies. The questionnaire includes questions on a 5-level Likert scale and open-ended questions about their strengths and weaknesses in communication as well as their rationale for the proposed solutions. Based on students' self-assessment, the average scores for verbal and written communication skills are at a Good level. However, students show weaknesses in non-verbal communication and confidence. The proposed measures generally received support from students who responded to the survey, and students also proposed other diverse solutions to develop these competency groups.
Scocial Sciences-Humanities
The image of the traveller in Nguyen De’s Chinese poetry
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The traveler is the central artistic image in Nguyen De’s Chinese poetry. What stands out in this image is the feeling of loneliness and deadlock before the reality of wandering. The research was conducted with the aim of clarifying the characteristics of the image of the traveler in Nguyen De’s Chinese poetry, specifically the attitude and behavior of the traveler when facing loneliness and deadlock. Research results show that the image of a traveler when faced with feelings of loneliness and deadlock before reality shows three main characteristics: (1) the traveler alone experiences the sadness of loneliness and the tendency to “prolong” inner tragedy, (2) the traveler tries his best to act with a little hope of escaping his loneliness, (3) the traveler looks to the future to find a solution to escape the lonely, deadlocked reality. The feeling of loneliness and deadlock in the face of reality is always constant and strongly dominates the traveler’s mind making people more pitiful than ever.
Determining the factors affecting people's requirements for urban art in Can Tho city
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The study aims to identify factors affecting people's needs for urban art (MTDT) in Can Tho city. The analysis results showed that KMO coefficient = 0.897 (sig. = 0.00), total variance extracted 72.10%; distinguish between 2 groups of factors: architectural type, architectural style, and historical and cultural values with 12 criteria; Spatial order, community interaction, and art have 8 criteria and have a greater positive influence on the level of meeting the ethnic environment of people in Can Tho city with β = 0.562. Urban art in Can Tho is assessed to meet the needs of the people (average value is 3.6). However, there are still limitations such as controlling dirty wall painting and advertising and Renovating and beautifying abandoned and dilapidated urban spaces. There needs to be solutions to address limitations/difficulties to meet people's needs better. The research is a reference base for additional requirements for urban landscape planning in the future.
The effect of loneliness on depression: The mediation role of resilience
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Resilience impacts the relationship between loneliness and depression, which is quite common among the elderly but has not been extensively studied in younger populations. This research will analyze the relationship between loneliness and depression and simultaneously verify the role of resilience. Using the linear structural model SEM through the survey data of 523 students in Hanoi city shows that resilience plays a moderate role, decreasing the negative influence between loneliness and depression. Based on the result, some recommendations are given to improve the loneliness situation and depression among young people, especially students in Hanoi city.
Economics
Effects of airline corporate social responsibility on service quality, trust, and customer loyalty: Empirical evidence at Bamboo Airways
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The aviation industry plays an important role in promoting each country’s economic growth. In the context of fierce competition, each airline aims to retain customers by improving service quality and pioneers in implementing social responsibility, especially contributing to sustainable development. The purpose of this study is to evaluate the impact of corporate social responsibility and airline service quality on customer trust and loyalty. The study uses the partial least squares structural modelling method on a data set of 325 customers of Bamboo Airways. The results showed that the direct effect of corporate social responsibility on customer loyalty. In addition, the mediating role of service quality and customer trust is also explored. The study also proposes management implications for improving Bamboo Airways’ corporate social responsibility.
The influence of smart tourism services on tourist satisfaction in Can Tho destination, Viet Nam
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This study aims to investigate the impact of smart tourism services on customer satisfaction at the destination of Can Tho, Vietnam. Based on the E-Servqual research model by Parasuraman et al. (2005), applied in the context of evaluating the quality of smart tourism services in Can Tho, Vietnam, combined with 400 valid responses from domestic and international tourists in Can Tho, The data analysis results from SPSS.20 and SmartPLS software show the components of smart tourism services, including (1) Smart attraction services, (2) Smart accommodation services, (3) Smart transformation services, (4) Smart catering services, (5) Smart shopping services have a strong impact on the quality of smart tourism services, which subsequently contributes to customer satisfaction when travelling in Can Tho. We provide suggestions for managerial implications based on these findings, aiming to improve the quality of smart service and customer satisfaction in the context of integrating technology and smart concepts into all aspects of tourism and hospitality.