Science and Technology Development Journal

Latest Articles

1. Viet Nam National Young Scientists Conference 2023

   Measurement of cosmic muon angular distribution and deposited energy using sFGD prototype in the T2K upgrade ND280

   Nguyen Thi D., Lê A., Nguyễn C., Nguyen D., Bui H., Bui H.

   The superFGD (sFGD), a scintillator detector, has been chosen as the target for neutrino in the T2K near detector upgrade. Its design enables nearly 4π coverage for neutrino interactions, leading to lower energy thresholds and reduced systematic errors in the experiment. The sFGD is assembled of optically-isolated scintillators measuring 1 × 1 × 1 cm³, it ensures the nessary spatial and energy resolution to minimize uncertainties in future T2K runs. With close to two million cubes assembled into a volumn of 1920 × 560 × 1840 mm³, the sFGD is a significant advencement. A prototypeconsisting of 4×4×3 cubes was studied using cosmic rays. The sFGD prototype, consisting of 48 cubes, was instrumented. We also present the results of the GEANT4 simulation of this prototype. Cosmic ray muon tracks crossing this prototype were simulated by the CRY generator. The results on angular distribution and energy deposition are studied at Tokai (36°27'42.8’N 140°35'57.7’E) and are presented in this paper.

   Published: 2024-08-18In press
2. Section: NATURAL SCIENCES

   The Dependence on the Armchair/zigzag Edge Ratio of the Melting Process of Armchair Hexagonal Boron Nitride Nanoribbon

   Nguyen H.

   The dependence on the armchair/zigzag edge ratios of armchair hexagonal boron nitride nanoribbon (h-BNNR) is investigated by molecular dynamics simulation. To do that, initial configurations with eight different armchair/zigzag edge ratios (0.017377, 0.069510, 0.278481, 0.434782, 1.724409, 6.968254, 10.745098, and 43.88) of armchair h-BNNR containing the same number of atoms (10000 identical atoms of B and N) are heated from 50 K to 7000 K via Tersoff potential. The initial (0.017377 armchair/zigzag ratio) and the final (43.88 armchair/zigzag ratio) configuration strongly affect the melting process of armchair h-BNNR: The 0.017377 armchair/zigzag configuration has a high value of the melting point (5300 K) in comparison to the left seven cases; The melting process of the 43.88 armchair/zigzag ratio configuration is strongly affected by the finite size effects. The melting point of the left six configurations is not affected by the armchair/zigzag edge ratio much and the average value of the melting point for these cases is 4180 K. In the case of 10000 atoms in the configuration, the critical armchair/zigzag edge ratio is found at 10.745098. At this critical armchair/zigzag edge ratio, the melting point fluctuates a bit about 4040 K when the number of atoms in the configuration is increased from 10000 to 25600 atoms. Note that, the melting point of the configuration having this critical armchair/zigzag ratio will not be affected much when the number of atoms in the configuration is increased.

   Published: 2024-07-21In press
3. Section: ENGINEERING AND TECHNOLOGY

   ACNE8M - An acnes detection and differential diagnosis system using AI technologies

   Nguyen P., K., Le T., Nguyen B., A., Nguyen P. A.

   Acne is a prevalent skin condition that can lead to serious consequences in severe cases. Traditional treatment requires patients to visit a dermatologist. However, acne diagnosis performed by dermatologists often encounters issues, such as being manual and highly inaccurate. Therefore, there is a need for machinery to assist in the acne diagnosis phase. Numerous image analysis algorithms have been developed using images captured by mobile devices. Nonetheless, most of these algorithms primarily rely on outdated features such as color models or texture-based features, which may result in poor performance when dealing with the intricate nature of acne lesions. Consequently, AI models have been developed for the task of acne detection. However, due to the rarity of high-quality datasets for acne, some of these models have yet to achieve significant results. To overcome these limitations, this paper proposes the ACNE8M, an AI model developed based on the YOLOv8 pre-trained model, to accurately detect seven primary and secondary types of acne lesions, as well as differentiate five additional diagnoses. The model is trained on a well-prepared dataset containing 9,440 images with numerous acne lesions adequately labeled. The results show that the model achieves state-of-the-art performance with a mean Average Precision (mAP) score of 0.69 across the 12 types. The accuracy of detecting each type of acne is impressively high and balanced between the classes, despite the dataset's imbalance caused by the unequal number of images in each acne category. With this study, ACNE8M is expected to provide medical support in the acne diagnosis process and help patients understand their conditions for better treatment.

   Published: 2024-07-21In press
4. Section: NATURAL SCIENCES

   Copper promoted, direct sulfenylation of n-aryl pyrazoles

   Nguyen T., Pham A., Pham H., Le H.

   Direct functionalization of N-heterocycles often attracts substantial attention, as the targeted compounds find ubiquitous uses in many applications. Among common N-heterocycles, substituted pyrazoles are still challenging compounds for functionalization, though commonly useful in bio- and material-related studies. Herein, we report a general method for direct sulfenylation at the C₄-H bonds of pyrazoles with diaryl disulfides. This transformation produces unsymmetrical thioethers, which often require the use of pre-functionalized starting materials and partners with unpleasant smells. Our reaction conditions involve the use of a CuCl₂ catalyst, K₂S₂O₈ oxidant, and CH₃COOH as the solvent. A wide range of functionalities, including bromo, chloro, and nitro groups, were well-compatible. A possible mechanism, including electrophilic sulfenylation, was proposed.

   Published: 2024-07-21In press
5. Special Issue

   Genomic insights into colistin resistance evolution in Pseudomonas Aeruginosa

   Tran N., B., V., Mai A., T., Le N., T., Huynh T., Q., Vu M., T., Le M., T., Nguyen T. T. H.

   Colistin (polymyxin E) is the last-resort antibiotic used to treat multidrug-resistant Gram-negative bacterial infections, including those caused by Pseudomonas aeruginosa. The global emergence of colistin-resistant Pseudomonas aeruginosa is a significant concern for healthcare professionals. Therefore, identifying key contributors to the development of colistin resistance is crucial for addressing this issue. In this study, P. aeruginosa ATCC 9027 was serially exposed to subminimal inhibitory concentrations (MICs) of colistin for 14 consecutive days to obtain the Col-E1 strain. The Col-E1 strain was then cultured for 10 days in antibiotic-free medium to acquire the Col-E2 strain. The whole-genome sequences of three strains, namely, P. aeruginosa ATCC 9027 (the original strain, PA-1), Col-E1 and Col-E2, were assembled, annotated and analyzed. The bioinformatics pipeline included FASTQC (v0.11.9) for quality control; Unicycler (v.0.5.0) for de novo assembly; Bowtie2 (v2.4.5) and Picard Tools (v.2.27.4) for alignment; SAMtools (v1.11) and BCFtools (v.1.15) for variant calling; and SnpEff (v5.1) for variant annotation. As a result, we obtained a draft genome of P. aeruginosa ATCC 9027 consisting of 6,314,207 bp with 146-fold coverage. After aligning Col-E1 and Col-E2 against the draft genome, the number of insertion-deletions (INDELs) and single nucleotide polymorphisms (SNPs) were found, with 486 INDELs and 162 SNPs for Col-E1 and 474 INDELs and 163 SNPs for Col-E2. A high overlap rate of variants, including 448 INDELs and 153 SNPs, was observed between Col-E1 and Col-E2, indicating that the number of variants was constant. The analysis revealed notable mutations in genes encoding ribosomal components (rpsL, rpsG, and rpsJ), genes involved in efflux transmembrane transporter activity (czcC_1), and genes encoding an outer membrane porin (oprD). The variants were found in upstream (36.5%), downstream (25.7%) or intergenic (19.1%) regions. These mutations may be involved in gene expression regulation, leading to the development of a colistin-resistant phenotype. In conclusion, this study provided a preliminary overview of how P. aeruginosa responds to colistin antibiotic stress at the genomic level. These mutations could be used as markers for colistin resistance and further investigated to clarify their role in the colistin resistance of Pseudomonas aeruginosa.

   Published: 2024-07-14
6. Special Issue

   Assessing vulnerability to flood hazard of households in Phong Nha town, Bo Trach district, Quang Binh province

   Ta H., Vu Y., Nguyen T., Nguyen H.

   This study focuses on assessing the vulnerability of households in Phong Nha town, Bo Trach district, Quang Binh province to flood hazard. A set of 23 indicators for assessing vulnerability to flood was proposed based on three components: exposure, sensitivity, and adaptive capacity. The study area, famous for the Phong Nha-Ke Bang World Heritage Site, has been severely affected by floods. A substantial 81% of households experienced flood damage in 5 recent years in 2019-2023. In particular, the October 2020 flood devastated 85% of households in the town. The study results showed 39% of households have children under five years old and above 65 years old. Regarding adaptive capacity, 56% of interviewed households have basic mitigation tools and only 9.0% actively participate in disaster prevention training course and 4% have property insurance. The values of exposure, sensitivity, and adaptive capacity are 0,67; 0.32; 0.37 in scale 0-1, respectively. The quantitative assessment of the vulnerability of households in Phong Nha town to flood hazard is 0.62 on the scale of -1 and +1, indicating a relatively high level of vulnerability. The results provide a basis for managers to strengthen measures to improve local people's adaptive capacity in preparing for disaster prevention in general and floods in particular.

   Published: 2024-07-08In press
7. Section: ENGINEERING AND TECHNOLOGY

   The effect of reaction conditions and catalysts on the pyrolysis of polyethylene

   Tran T., Tran H., Tran D., Nguyen T., Phung T., K., Do T.

   Pyrolysis of plastic is a green technology for converting plastic into fuel. This work studies the thermal and catalytic pyrolysis of polyethylene.

   Published: 2024-06-303375-3384
8. Section: ENGINEERING AND TECHNOLOGY

   Effect of reaction conditions on the etherification between glycerol and tert-butyl alcohol over beta zeolite

   Nguyen H.,-G., Dang P., Nguyen T., Phung T., K., Do T.

   Glycerol tert-butyl ethers (GTBEs) can be used as diesel additives due to their physico-chemical properties, such as flash point, viscosity, and cetane number. GTBEs were produced from the reaction between tert-butyl alcohol and glycerol using a stirred reactor at moderate temperatures. This study aims to discuss the effect of reaction conditions on the etherification between glycerol and tert-butyl alcohol.

   Published: 2024-06-303385-3392
9. Section: ENGINEERING AND TECHNOLOGY

   The effect of temperature and reaction time on the physicochemical properties of oxidized bacterial cellulose membranes for hemostatic dressings

   Nguyen K., Nguyen T., Nguyen H., Luong T., Huynh T., Tran K., Nguyen B., Nguyen H., La T., Nguyen H., Doan H., Nguyen H.

   The development of an oxidized bacterial cellulose membrane (OBC) for hemostasis application is essential for preventing death from excessive bleeding. In previous research, OBC membranes were fabricated by using many different oxidation systems, notably the HNO₃/H₃PO₄-NaNO₂ system. In this study, the effects of oxidation conditions, such as temperature and reaction time, on the structure and physicochemical properties of OBC for hemostasis dressings oxidized by a mixture of HNO₃/H₃PO₄-NaNO₂ were investigated. The morphology of the OBC membranes was observed using a scanning electron microscope. Chemical modification was confirmed using Fourier transform infrared spectroscopy and carboxyl content analysis. The mechanical properties of the OBC membranes before and after oxidation were also evaluated by tensile testing. The results revealed an increase in the carboxyl content and a decrease in the mechanical properties of the OBC membranes with increasing temperature and reaction time. The results indicate that under the temperature and time conditions of the survey, the OBC membrane oxidized at 40 °C for 6 hours had a relatively high carboxyl content of 16.18% (suitable for hemostasis dressing) while maintaining sufficient mechanical strength for wound dressing application.

   Published: 2024-06-303393-3400
10. Section: ENGINEERING AND TECHNOLOGY

    Real-Time Convolutional Neural Network-Based Method for Detecting and Tracking Human Motion on Quadcopters

    Tran D., Tran T.

    This paper proposes a convolutional neural network (CNN) method for human motion detection and tracking on a quadcopter. To address the challenges mentioned above, the proposed methodology is designed on computer vision techniques with an object tracking algorithm and a CNN model. The object tracking algorithm is implemented using a proportional integral differential (PID) controller to calculate the control parameters, including the pitch and yaw angles, in real time. These parameters are determined by calculating the offset between the position of the human and the camera coordinate frame. To achieve accurate object detection, a CNN model is designed based on the single shot multibox detector (SSD) architecture, which is crucial for object detection. The model above is integrated with the MobileNet base network, which is responsible for feature extraction of the object. The use of self-collected person data in model training ensures good performance for this specific application. The object detection results demonstrate that the model achieves a high level of accuracy (98%). The proposed methodology is applied to an NVIDIA Jetson NANO computer. To rigorously assess the control system, the proposed methodology was used to conduct outdoor flight tests on a campus. These tests prioritized minimal pedestrian traffic and stable weather conditions, ensuring a controlled environment for evaluation. Analysis of the flight data and signal graphs provided valuable insights into the effectiveness of the system.

    Published: 2024-06-303401-3415