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Results 11-20 of 485 (Search time: 0.005 seconds).
  • Authors: Tran, Vu Diem Ngoc; Le, Van Vinh; Vu, Lai Hoang; Nguyen, Ba Hung; Dinh, Thi Hinh; Pham, Ky Nam;  Advisor: -;  Co-Author: - (2021)

    This study investigated the structure evolution, surface morphology, dielectric properties, ferroelectric properties, piezoelectric properties, and electromechanical strain properties of lead-free (Bi0.5−xLax)(Na0.41K0.09)TiO3 piezoelectric ceramics. All samples were fabricated by a traditional solid-state synthesis. The effects of La3+-isovalent substituted on Bi3+-site of the Bi0.5Na0.41K0.09TiO3 system were examined. The addition of La doping in the Bi0.5Na0.41K0.09TiO3 ceramics induced the second phase of K4Ti3O8 and a crystal structural change from the rhombohedral and tetragonal phase to a pseudocubic phase. All samples show similar grain morphology and dense microstructure with the average grain size around 1.33 to 1.61 μm. The dielectric curves and field-induced polarization...

  • Authors: Phung, Cao Dai; Tran, Tuan Hiep; Choi, Ju-Yeon; Jeong, Jee-Heon; Ku, Sae Kwang; Yong, Chul Soon; Kim, Jong Oh;  Advisor: -;  Co-Author: - (2021)

    Cellular FLIP (cFLIP) is a crucial player of apoptosis-regulated pathways that is frequently overexpressed in solid cancers. To inhibit c-FLIP, pre- and post-transcriptionally, a multifunctional nanoparticle (NP) was created to deliver cFLIP-specific small interfering RNA (siRNA) into cancer cells. Specifically, Vorinostat (Vor)-loaded mesoporous silica nanoparticles (MSN) were conjugated with polyethylenimine-biotin (PB), followed by electrostatically binding with cFLIP siRNA (Vor/siR@MSN-PB). To stabilize and prolong the circulation time of nanoparticles, a bialdehyde-modified poly(ethylene glycol) (PEG) was cross-linked onto the polyethylenimine (PEI) backbone via the formation of the imine linkage (Schiff base) (Vor/siR@MSN-PB-PEG). The Schiff base is highly stable at physiologi...

  • Authors: Nguyen, Thuong T.H.;  Advisor: Nguyen, Thu-Thao; Tran, Thuan Van; Tan Lam; Danh, Luu Thai; Than, Van Thai;  Co-Author: - (2021)

    This study aims to introduce the antibacterial and antioxidant activities of the Piper betle Linn oil (PBLO) into chitosan film (pCS), named as pCS-PBLO film. The morphology, structure, and properties of the pCS-PBLO film, along with the PBLO concentration between 0.4% and 1.2% (v/v), were determined. The film surface became rough and heterogeneous with the addition of PBLO, which directly influenced on mechanical strength of the resultant film. The addition of the PBLO did not affect thermal stability but significant effect on flexibility and mobility of the film. Importantly, the film enhanced the UV-protective property and antioxidant activity as incorporated-PBLO. Moreover, the resulting film revealed the great inhibition efficiency against the negative-gram (E. coli, P. aerugin...

  • Authors: Thanh Tan Doan;  Advisor: Nathalie Bostel; Minh Hoàng Hà;  Co-Author: - (2021)

    The Vehicle Routing Problem (VRP) is one of the most studied topics in Operations Research. Among the numerous variants of the VRP, this research addresses the VRP with relaxed priority rules (VRP-RPR) in which customers are assigned to several priority groups and customers with the highest priorities typically need to be served before lower priority ones. Additional rules are used to control the trade-off between priority and cost efficiency. We propose a Mixed Integer Linear Programming (MILP) model to formulate the problem and to solve small-sized instances. A metaheuristic based on the Adaptive Large Neighborhood Search (ALNS) algorithm with problem-tailored components is then designed to handle the problem at larger scales. The experimental results demonstrate the performance o...

  • Authors: Minh-Hoang Nguyen;  Advisor: Huyen Thanh Thanh Nguyen; Tam-Tri Le; Anh-Phuong Luong; Quan-Hoang Vuong;  Co-Author: - (2021)

    Purpose The current review aims to examine the growth trajectory, most influential documents, intellectual and conceptual structure of the literature regarding gender issues in family business research. Design/methodology/approach The bibliometric analysis was performed using 224 documents from 1991 to 2020 extracted from the Web of Science database. Findings The review finds that this field's knowledge grew exponentially during the last three decades, mainly after 2003 and the last several years. Based on the co-citation analysis, three major research lines are identified: “Women's challenges and opportunities in the family business”, “Gender diversity in the family business corporate board”, and “Gender and family SMEs management.” The temporal co-word analysis reveals th...

  • Authors: Orfanoudaki, Maria;  Advisor: Hartmann, Anja; Alilou, Mostafa; Mehic, Naida; Kwiatkowski, Marcel; Jöhrer, Karin; Nguyen, Ngoc Hieu; Hensel, Andreas; Greil, Richard; Ganzera, Markus;  Co-Author: - (2021)

    The class of demosponges is the biggest and most diverse of all described sponge species and it is reported to produce a plethora of chemically different metabolites with interesting biological activities. The focus of the present study was to investigate the chemical composition of two Mediterranean demosponges, targeting their brominated compounds and prenylated hydroquinones, compounds with interesting cytotoxic and anti-microbial properties. In order to gain a deeper insight into the chemical diversity of their metabolites and their activities, 20 pure secondary metabolites including new natural products were isolated from two different species (Aplysina aerophoba and Spongia sp.) using various chromatographic techniques. Their structures were confirmed by NMR and HRMS, revealin...

  • Authors: Vuong, Quan-Hoang;  Advisor: La, Viet-Phuong; Ho, Manh-Toan; Pham, Thanh-Hang; Vuong, Thu-Trang; Vuong, Ha-My; Nguyen, Minh-Hoang;  Co-Author: - (2021)

    Science, technology, engineering, and mathematics (STEM) education has become a critical factor in promoting sustainable development. Meanwhile, book reading is still an essential method for cognitive development and knowledge acquisition. In developing countries where STEM teaching and learning resources are limited, book reading is an important educational tool to promote STEM. Nevertheless, public data sets about STEM education and book reading behaviors in emerging countries are scarce. This article, therefore, aims to present a data set of 4,966 secondary school students from a school-based data collection in Vietnam. The data set comprises of five major categories: 1) students' personal information (including STEM performance), 2) family-related information, 3) book reading pr...

  • Authors: Le, Tien-Thinh;  Advisor: Le, Minh Vuong;  Co-Author: - (2021)

    This paper investigates the nanoscale effect on the effective bulk modulus of nanoparticle-reinforced polymer. An interface-based model is introduced in this work to study the nanoscale effects on the effective properties of heterogeneous materials. That interface model is able to capture discontinuity of mechanical fields across the surface between the nanoparticle and matrix. A generalized self-consistent scheme is then employed to determine the effective bulk modulus. It has been seen from the results that, in a certain range of limits, the influence of nanoscale effects on effective properties of heterogeneous materials is significant and needs to be taken into account. In particular, when the nanoparticle radius is smaller than 10 nm, the value of effective bulk modulus signifi...

  • Authors: Jaime A Teixeira da Silva;  Advisor: Quan-Hoang Vuong;  Co-Author: - (2021)

    One of the aspects of post-publication peer review that is difficult for reputable journals or publishers to accept is that it may reveal flaws in their oft-claimed resilient peer review and efficient editorial management. Prospective authors are frequently sold a brand-associated image of a fail-safe process, rigorous editorial handling, and stringent peer review. Yet, in reality, a sector of the published literature that has passed through claimed rigorous screening may still be flawed and contain errors, while some of the peer-reviewed literature is the product of fraud or misconduct. Even top-ranked journals, in terms of journal-based metrics such as the Clarivate Analytics’ journal impact factor, or those that are indexed or hosted on platforms like PubMed, Scopus or Web of Sci...

  • Authors: Le, Tien-Thinh;  Advisor: Nguyen, Van-Hai; Le, Minh Vuong;  Co-Author: - (2021)

    This paper is devoted to the development of a deep learning- (DL-) based model to detect crack fractures on concrete surfaces. The developed model for the classification of images was based on a DL Convolutional Neural Network (CNN). To train and validate the CNN model, a database containing 40,000 images of concrete surfaces (with and without cracks) was collected from the available literature. Several conditions on the concrete surfaces were taken into account such as illumination and surface finish (i.e., exposed, plastering, and paint). Various error measurement criteria such as accuracy, precision, recall, specificity, and F1-score were employed for accessing the quality of the developed model. Results showed that for the training dataset (50% of the database), the precision, r...