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Results 411-420 of 691 (Search time: 0.001 seconds).
  • Authors: Luan, Luong Chu;  Advisor: -;  Co-Author: - (2022)

    Terpenoids represent the largest group of secondary metabolites with variable structures and functions. Terpenoids are well known for their beneficial application in human life, such as pharmaceutical products, vitamins, hormones, anticancer drugs, cosmetics, flavors and fragrances, foods, agriculture, and biofuels. Recently, engineering microbial cells have been provided with a sustainable approach to produce terpenoids with high yields. Noticeably, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) system has emerged as one of the most efficient genome-editing technologies to engineer microorganisms for improving terpenoid production. In this review, we summarize the application of the CRISPR-Cas system for the production of terpenoids in micro...

  • Authors: Anh D. Phan;  Advisor: -;  Co-Author: - (2022)

    This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature (Tg) are calculated at different temperatures and vitrification criteria. Molecular dynamics is significantly slowed down near rough solid surfaces, and the dynamics at location far from the interfaces is sped up. In thick films, the mobility gradient normalized by the bulk value obeys the double-exponential form since interference effects between two surfaces are weak. Reducing the film thickness induces a strong dynamic coupling between two surfaces and flattens the relaxation gradient. The normalized gra...

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

    Currently, gaming is the world's favorite form of entertainment. Various studies have shown how games impact players' perceptions and behaviors, prompting opportunities for purposes beyond entertainment. This study uses Animal Crossing: New Horizons (ACNH)—a real-time life-simulation game—as a unique case study of how video games can affect humans' environmental perceptions. A dataset of 584 observations from a survey of ACNH players and the Hamiltonian MCMC technique have enabled us to explore the relationship between in-game behaviors and perceptions. Here we show a probabilistic trend towards exploiting the in-game environment despite players' perceptions, suggesting that the simplification of commercial game design may overlook opportunities to engage and educate players in pro-...

  • Authors: Nguyễn, Ngọc Việt;  Advisor: -;  Co-Author: - (2022)

    Phát hiện các tế bào ung thư tuần hoàn (CTCs) đã nổi lên như một giải pháp hấp dẫn trong nhận diện sớm ung thư. Thông thường, các tế bào CTCs, cũng như các tế bào ung thư khác có kích thước lớn hơn các tế bào bình thường. Nghiên cứu này trình bày các khảo sát số của một kênh vi lưu liên tục kết hợp phương pháp bất điện di (DEP) trong việc phân tách CTCs. Các điều kiện thích hợp của điện trường kích thích và lưu lượng dòng chảy trong vi kênh đã được áp dụng để cách ly hiệu quả các tế bào CTCs khỏi các tế bào bình thường trong mẫu máu. Hiệu suất của quá trình phân tách CTCs được đánh giá thông qua quan sát các quỹ đạo dịch chuyển tế bào. Một số thiết kế vi kênh cũng được xem xét để tìm kiếm cấu hình tối ưu. Các kết quả đã chứng tỏ rằng, các tế bào CTCs có thể phân tách khỏi các tế bào...

  • Authors: Tien-Thinh Le; Panagiotis G. Asteris; Minas E. Lemonis;  Advisor: -;  Co-Author: - (2021)

    This work aims to develop a novel and practical equation for predicting the axial load of rectangular concrete-filled steel tubular (CFST) columns based on soft computing techniques. More precisely, a dataset containing 880 experimental tests was first collected from the available literature for the development of an artificial neural network (ANN) model. An optimization strategy was conducted to obtain a final set of ANN’s architecture as well as its weight and bias parameters. The performance of the developed ANN was then compared to current codes (AS, EN, AIJ, ACI, AISC, LRFD, and DBJ) and existing empirical equations. The accuracy of the present model was found superior to the results obtained by others when predicting the axial load of rectangular CFST columns. For practical ap...

  • Authors: Tran, Dinh Cuong; Anh, D. Phan;  Advisor: -;  Co-Author: - (2022)

    Vacancies are prevalent point defects in crystals, but their thermal responses are elusive. Herein, we formulate a simple theoretical model to shed light on the vacancy evolution during heating. Vibrational excitations are thoroughly investigated via moment recurrence techniques in quantum statistical mechanics. On that basis, we carry out numerical analyses for Ag, Cu, and Ni with the Sutton–Chen many-body potential. Our results reveal that the well-known Arrhenius law is insufficient to describe the proliferation of vacancies. Specifically, anharmonic effects lead to a strong nonlinearity in the Gibbs energy of vacancy formation. Our physical picture is well supported by previous simulations and experiments

  • Authors: Vu, Le Huy; Le, Thi Huyen Linh; Nguyen, Dinh Dzung;  Advisor: -;  Co-Author: - (2021)

    Parallel robots are being applied popular in industry. They usually have many closed-loop kinematic structures, therefore their movement equations have the form of redundant coordinates and are complex. In most cases, parameters of dynamic model of the parallel robots required to be known exactly for control problem using the control laws such as PD, PID, CTC. This study is going to see in which the conditions of the Rostock Delta parallel robot should be used well with the PD control law. The movement equations of Rostock Delta robot in the form of differential equation system with redundant generalized coordinates is used to establish the PD control law. The stableness of the control law is also proved. Tracking control of a specific Rostock Delta robot is then simulated to see wh...

  • Authors: Minh-Hoang Nguyen;  Advisor: -;  Co-Author: - (2021)

    Urban humans and biodiversity-related concepts are interacting with each other in many negative and positive ways. The biodiversity provides a wide array of provision and cultural-ecological services to urban residents, but it is being overexploited to the point of crisis. The crisis is largely driven by the expanding illegal wildlife trade in developing countries with a high urbanization rate and biodiversity level like Vietnam. While supply-side measures are ineffective in reducing biodiversity loss, researchers have suggested demand-side measures as supplements, such as social marketing campaigns and law enforcement in urban areas. Moreover, urban residents are also potential visitors to urban public parks and national parks, which helps generate finance for biodiversity preserva...

  • Authors: Nguyen Thanh Vinh; Tran Van Dang; Bui Thi Hang; Anh-Tuan Le; Nguyen Tri Tuan; Le Khanh Vinh; Nguyen Van Quy;  Advisor: -;  Co-Author: - (2021)

    The sensing material plays a very important role in determining the sensing properties of a gas sensor. In order to synthesise the sensing material, the precursors have a large effect on the properties of the sensing material. In this study, three types of γ-Fe2O3 nanoparticles were prepared with different ferric ion concentrations of [Fe3+] and [Fe2+] as precursors, by a typical facile chemical precipitation process and a following annealing treatment. A mass-type gas sensor was fabricated by using a quartz crystal microbalance (QCM) coated with various γ-Fe2O3 nanoparticles. The morphology, crystallisation, and gas adsorption characteristics of the γ-Fe2O3 nanoparticles were investigated. The effect of ferric ion concentrations of [Fe3+] and [Fe2+] on sensing properties is discuss...