ハノイ市における繊維質材料混合流動化処理土の埋戻し地盤への適用に関する研究

In this study, the applicability to back fill ground by Liquefied Stabilized Soil (LSS) mixed with fibered material in Hanoi city of Vietnam has been investigated. Research works including experiment and analysis have been conducted simultaneously aiming to promote the application of LSS in Vietnam in the coming time. (1) Effect of time-dependency on strength and deformation characteristics of LSS mixed with fibered material was evaluated. A series of Consolidated–Undrained triaxial compression tests with measured pore water (CUB tests) under the various conditions at constant strain rates, constant deviator stress, and strain rates changed during monotonic loading have been carried out for LSS mixed with fibered material content of 0 and 20 kg/m3 at curing time of 28 and 56 days, respectively. Based on the test results, it was found that the effect of time-dependency is not seen in stress-strain curve independently of curing time. (2) The difference in triaxial shear property of LSS mixed with fibered material cured in laboratory and at field was investigated to be carried out a series of CUB tests for both specimens of LSS mixed with fibered material amount of 0 and 20 kg/m3 prepared by trimming LSS retrieved from a model ground by block sampling and cured in laboratory at curing time of 28 and 56 days, respectively. Based on the test results, it was found that the maximum deviator stress in q~ε_a relations of LSS mixed with fiber material cured at field tend to be larger than that cured in laboratory, and the brittle property of LSS after the peak in q~ε_a relations has been improved to ductile property by the addition of fiber material even in field. (3) In-situ stiffness of backfilling ground reinforced with fiber was investigated by using of portable Falling Weight Deflectometer at curing time of 28, 56 and 84 days, respectively. The stiffness was estimated by Young’s modulus EP.FWD calculated from KP.FWD-value. In parallel, in order to comparing with the tangent Young’s modulus Etan obtained from q~ε_a relations, a series of CUB tests have been carried out for specimens prepared by trimming LSS retrieved by block sampling from the model ground. It is considered that the KP.FWD-value is able to be estimated the stiffness of backfilling ground by LSS reinforced with fibered material. (4) A procedure for prediction of train-induced vibration from railway tunnels in conformity with criteria of Vietnam has been established as an example for Hanoi metro line No.3. The vibration propagation from the tunnel into the ground surface was analyzed by the 2-D FEM. The numerical results in terms of vibration velocity allow estimating the vibration velocity level, and then it is applicable to the prediction of train-induced vibration. (5) Using the established procedure, it is found that the train-induced vibration decreases when LSS for backfill ground of cut and cover tunnel is used. This will be a new advantage. Then, it is considered that the application to backfilling ground by LSS become one of effective measure for mitigation of the train-induced vibration.室蘭工業大学 (Muroran Institute of Technology)博士（工学

PSO based Hybrid PID-FLC Sugeno Control for Excitation System of Large Synchronous Motor

This paper proposes a hybrid control system integrating a PID controller and a fuzzy logic controller, using the particle swarm optimization (PSO) algorithm to optimize control parameters. The control object is an excitation system for a large synchronous motor, which is widely used in large power transmission systems. In practice, the change in load and excitation source can affect the operating mode of the motor. Therefore, a hybrid controller is designed to stabilize the power factor, resulting in better working performance. In the control algorithm, a PID controller is initially designed using PSO to optimize the control coefficients. The FLC-Sugeno control is then integrated with the PID, in which PSO is utilized to optimize membership functions. Numerical simulation results demonstrate the advantages of the proposed approach. Doi: 10.28991/ESJ-2022-06-02-01 Full Text: PD

Isolation and identification of phenolic compounds from the leaf extract of Cassia alata L.

Cassia alata is one of the most important species of the genus Cassia which is rich in anthraquinones and polyphenols. This plant is used as a medicinal material of which the leaves are known to have laxative and antibiotic properties. In our study, the methanol leaf extract of C. alata showed a significant antibacterial activity against human pathogenic bacteria strains Staphylococcus aureus and Bacillus cereus. The organic layers such as n-hexane, ethyl acetate, and aqueous layers, were prepared by partitioning the methanol extract with n-hexane and ethyl acetate successively.  We successfully isolated and identified the structures of five compounds from C. alata leaves. Their structures were elucidated by MS and NMR spectroscopic methods as well as comparison with literature data. These compounds were determined to be methyl 2,4,6-trihydroxybenzoate (1), kaempferol (2), (-)epiafzelechin (3), kaempferol-3-O-glucoside (4) and kaempferol-3-O-gentiobioside (5). Keywords. Cassia alata L., epiafzelechin, kaempferol, kaempferol-3-O-glucoside, kaempferol-3-O-gentiobioside

Study on association between SLC2A9 rs3733591 and Gout susceptibility in 481 Vietnamese individuals

Gout is a common form of inflammatory arthritis that is strongly associated with elevated uric acid concentration in the blood. The development of the disease is not only triggered by environmental factors but also genetic variations. Previous studies demonstrated that the genetic associations with gout vary in different populations in the world. This study aimed to identify the relationship between SLC2A9 rs3733591 and gout susceptibility in the Vietnamese population. Total DNAs were extracted from 481 blood samples including 160 patients with gout and 321 age-matched healthy controls. The genotyping of SLC2A9 rs3733591 was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Chi-squared test was used to test whether the genotypes frequencies of rs3733591 follow Hardy-Weinberg equilibrium (HWE) and to check its association with gout in three models (additive, recessive, dominant) and allele form. The result showed that SLC2A9 rs3733591 was in agreement with Hardy-Weinberg equilibrium (p>0.05). However, there was no association between the rs3733591 and gout in any tested models (p>0.05). This study will contribute to the genetic study of gout susceptibility in Vietnam

Lecane (Rotifera: Lecanidae) community in psammon habitat in Central Coast Vietnam: Diversity and relation to environmental condition

Characteristics of the Lecane (Rotifera) community in psammon in Central Coast Vietnam were investigated. A total of 50 taxa were identified in samples collected at hygropsammon zones of temporary pools, contributing 4 new species to rotifers' record of Vietnam. Psammonxenic species accounted for the largest percentage of Lecane community with 82%, followed by psammophiles (12%) and psammonbionts (6%). Influences of some environmental factors on the distribution of psammic lecanids were also observed. This group of organisms showed a slight tendency towards sand with grain sizes larger than 125 µm. Besides, other abiotic factors including pH, total phosphorus (TP) and total dissolved solids (TDS) were also found to significantly related to the distribution of some common Lecane species

Frequency and Risk Factor of Lower-limb Deep Vein Thrombosis after Major Orthopedic Surgery in Vietnamese Patients

BACKGROUND: Deep venous thrombosis (DVT) is a prevalent complication of orthopedic surgery. According in many studies. The incidence of DVT may be up to 50% if thromboprophylaxis is not available. AIM: The objective of this study was to check the degree of disease, clinical characteristics and analyzed factors in vulnerabilities with lower-limp DVT after orthopedic surgery in a Vietnam teaching hospital. METHODS: Orthopedic patients who met criteria were recruited at our hospital between August 2017 and June 2018. Ultrasound was used to discovering lower-limp DVT in pre-surgery and 7 days after surgery in all patients. RESULTS: The incidence of DVT after orthopedic surgery was 7.2%. Patients with older age (> 60) have a risk of 2 times higher of DVT after surgery than normal people (p < 0.05). The incidence of postoperative DVT was higher in immobile individuals > 72 hours (p < 0.05). Patients with prolonged surgical time (>120 minutes) had a higher risk of postoperative DVT than non-surgical patients’ surgery (p < 0.05). CONCLUSIONS: DVT remains a common complication following orthopedic surgery. Older age, immobility status, and surgical time have been found to be risky factors for the development of postoperative lower-limp DVT in orthopedic patients

A lab-on-a-chip system with integrated sample preparation and loop-mediated isothermal amplification for rapid and quantitative detection of Salmonella spp. in food samples

A lab-on-a-chip system with integrated sample preparation and real-time loop-mediated isothermal amplification for rapid detection of Salmonella in food samples.</p