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Results 101-110 of 205 (Search time: 0.002 seconds).
  • Authors: Van, Toan Nguyen; Duy, Khoe Dinh; Young, SunMok;  Advisor: -;  Co-Author: - (2022)

    This paper reports on the ethyl acetate (EA) removal over a honeycomb catalyst using an experimental design methodology. A mathematical model based on the response surface methodology is developed to evaluate the effect of parameters such as specific input energy (SIE), humidity, and EA concentration on the response variables (i.e., removal and energy efficiency). A set of experiments based on a statistical three-level full-factorial design of the experimental method were performed to collect the removal data

  • Authors: Vinh T. Nguyen; Truong V. Vu; Phan H. Nguyen;  Advisor: -;  Co-Author: - (2022)

    The present paper focuses on the motion due to the thermocapillary force of a droplet in a circular tube through the front-tracking-based simulation. The tube profile in the axial direction is generated with a sinusoidal function that induces a constriction with depth d at the middle. The droplet is slowed down as it migrates from the cold region (ahead of the constriction) to the hot region in the downstream. Various parameters including the Marangoni number Ma, the capillary number Ca and the depth of the constriction d are varied to better understand the thermocapillary motion of the droplet under the influence of the constriction. The simulation results show that when the Ma number increases, the influence factor of the constriction increases and the migration velocity of the dr...

  • Authors: Tran, Quang Huy; Khai, Tuan Nguyen; Phuc, Thinh Doan; Duc,Tan Tran;  Advisor: -;  Co-Author: - (2022)

    In ultrasound tomography (UT), Born iterative method (BIM) and distorted-Born iterative method (DBIM) based on Born approximation are considered efficacious. DBIM offers faster convergence compared to BIM; however, it is more susceptible to noise and vice versa. Combined or multi-model imaging is an indispensable trend of modern imaging to detect and accurately assess tissue states. The proposed method exploits the advantages, limiting the disadvantages and increasing the imaging speed of the merging of BIM and DBIM

  • Authors: Thi Thu Huong, Tran; Tuan Anh, Nguyen; Thang Binh, Hoang; Duc Ngoc, Nguyen; Ngoc Duyen, Dang;  Advisor: -;  Co-Author: - (2022)

    The Automobiles are vehicles widely used to transport passengers and goods around the world. When traveling on the road, many factors affect the oscillation of the automobile. In particular, the stimuli from the road surface are the direct causes of its instability. The automobile’s suspension system has the role of regulating and extinguishing these oscillations quickly. To improve the efficiency, stability, and comfort of the vehicle, the active suspension system is proposed. This study establishes the quarter dynamics model to describe the vehicle’s oscillation

  • Authors: Hoang, Nhan Hoa; Hoang Hao, Le; Thien Giap, Le;  Advisor: -;  Co-Author: - (2022)

    Local delivery of drug is a promising strategy to manage periodontitis characterized by chronic inflammation of the soft tissue surrounding the teeth. An optimized system should prolong the drug retention time and exhibit controlled drug permeation through the buccal mucosal layer. This study was aimed to develop hydroxyethyl cellulose (HEC)-based gel containing metronidazole (MTZ) loaded in solid lipid nanoparticles (SLNs), and to enhance the antimicrobial activity of MTZ. SLNs were prepared using a combination method of solvent evaporation and hot homogenization. The results showed that the fabricated SLNs, comprising of Precirol (2.93%, w/v), Tween 80 (1.8%, w/v), and the drug:lipid ratio of 19.3% (w/w), were approximately 200 nm in size, with a narrow distribution. The HEC (3%, ...

  • Authors: Khanh V. Do; Erik, Hjorth; Ying, Wang;  Advisor: -;  Co-Author: - (2022)

    Alzheimer’s disease (AD) develops into dementia over a period of several years, during which subjective cognitive impairment (SCI) and mild cognitive impairment (MCI) can be used as intermediary diagnoses of increasing severity. Chronic neuroinflammation resulting from insufficient resolution is involved in the pathogenesis of AD and is associated with cognitive impairment

  • Authors: Dinh-Toi Chu; Hue, Vu Thi; Yen, Vy Nguyen Thi;  Advisor: -;  Co-Author: - (2022)

    This study describes the willingness of receiving the COVID-19 booster doses for adults and their children 12–17 years old, and its related factors in Vietnam. A cross-sectional study was conducted through a national online survey from November 17 to November 24, 2021 using Google Form. Study respondents were Vietnamese citizens who were ≥18 years old and currently living in Vietnam. A total of 900 complete responses were analyzed and of those 93.77% were willingness to receive the booster dose. Participants with a university degree or higher were 8.16 times higher in willingness than those with primary school (p = .017). Those who received the first or the second dose of the COVID-19 vaccine were 5.85 (p = .001) and 5.65 (p < 0.001) times higher in willingness to receive booster do...

  • Authors: Pham, Minh Tuan;  Advisor: -;  Co-Author: - (2022)

    Network Function Virtualization (NFV) can support customized on- demand network services with flexibility and cost-efficiency. Virtual Network Function (VNF) instances need to be scaled out, scaled in, and reallocated across the NFV infrastructure (NFVI) to avoid a violation of service agreements when the demand traffic changes. However, selecting the new placement of VNFs for migrating a service function chain (SFC) is an issue of efficient NFV control. We propose two novel integer linear programming (ILP) models and two approximation algorithms for SFC placement and migration to maximize the cost-efficiency of an NFV network regarding the changes of service demands and dynamic routing. The ILP models allow us to obtain the optimal solutions of SFC placement and migration with expl...

  • Authors: Duc-Nam Nguyen; Wonkyu, Moon;  Advisor: -;  Co-Author: - (2022)

    Electrospinning is a low-cost and straightforward method for producing various types of polymers in micro/nanofiber form. Among the various types of polymers, electrospun piezoelectric polymers have many potential applications. In this study, a new type of functional microfiber composed of poly(γ-benzyl-α,L-glutamate) (PBLG) and poly(vinylidene fluoride) (PVDF) with significantly enhanced electromechanical properties has been reported. Recently reported electrospun PBLG fibers exhibit polarity along the axial direction, while electrospun PVDF fibers have the highest net dipole moment in the transverse direction. Hence, a combination of PBLG and PVDF as a core–shell structure has been investigated in the present work. On polarization under a high voltage, enhancement in the net dipol...

  • Authors: Tran, Quang Huy; Nguyễn, Tuấn Khải; Vijender, Kumar Solanki; Trần, Đức Tân;  Advisor: -;  Co-Author: - (2022)

    Conventional Distorted Born Iterative Method (DBIM) using single frequency has low resolution and is prone to creating images with high-contrast subjects. We propose a productive frequency combination method to better result in tomographic ultrasound imaging based on the multi-frequency technique. This study uses the natural mechanism of emitting oscillators' frequencies and uses these frequencies for imaging in iterations. We use a fundamental tone (i.e., the starting frequency f0) for the first iteration in DBIM, then consecutively use its overtones for the next ones. The digital simulation scenarios are tested with other multi-frequency approaches to prove our method's feasibility. We performed 57 different simulation scenarios on the use of multi-frequency information for the DB...