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The purpose of this study is to design numerical simulations of bubbly flow around a cylinder to better understand the characteristics of flow around a rigid obstacle.

The bubbly flow around a circular cylinder was numerically simulated using a semi-Lagrangian–Lagrangian method composed of a vortex-in-cell method for the liquid phase and a Lagrangian description of the gas phase. Additionally, a penalization method was applied to account for the cylinder inside the flow. The slip condition of the bubbles on the cylinder’s surface was enforced, and the outflow conditions were applied to the liquid flow at the far field.

The simulation clarified the characteristics of a bubbly flow around a circular cylinder. The bubbles were shown to move around and separate from both sides of the cylinder, because of entrainment by the liquid shear layers. Once the bubbly flow fully developed, the bubbles distributed into groups and were dispersed downstream of the cylinder. A three-dimensional vortex structure of various scales was also shown to form downstream, whereas a quasi-stable two-dimensional vortex structure was observed upstream. Overall, the proposed method captured the characteristics of a bubbly flow around a cylinder well.

A semi-Lagrangian–Lagrangian approach was applied to simulate a bubbly flow around a circular cylinder. The simulations provided the detail features of these flow phenomena.

This paper aims to provide discussions of a numerical method for bubbly flows and the interaction between a vortex ring and a bubble plume.

Small bubbles are released into quiescent water from a cylinder tip. They rise under the buoyant force, forming a plume. A vortex ring is launched vertically upward into the bubble plume. The interactions between the vortex ring and the bubble plume are numerically simulated using a semi-Lagrangian–Lagrangian approach composed of a vortex-in-cell method for the fluid phase and a Lagrangian description of the gas phase.

A vortex ring can transport the bubbles surrounding it over a distance significantly depending on the correlative initial position between the bubbles and the core center. The motion of some bubbles is nearly periodic and gradually extinguishes with time. These bubble trajectories are similar to two-dimensional-helix shapes. The vortex is fragmented into multiple regions with high values of Q, the second invariant of velocity gradient tensor, settling at these regional centers. The entrained bubbles excite a growth rate of the vortex ring's azimuthal instability with a formation of the second- and third-harmonic oscillations of modes of 16 and 24, respectively.

A semi-Lagrangian–Lagrangian approach is applied to simulate the interactions between a vortex ring and a bubble plume. The simulations provide the detail features of the interactions.

This study aims to provide discussions of the numerical method and the bubbly flow characteristics of an annular bubble plume.

The bubbles, released from the annulus located at the bottom of the domain, rise owing to buoyant force. These released bubbles have diameters of 0.15–0.25 mm and satisfy the bubble flow rate of 4.1 mm³/s. The evolution of the three-dimensional annular bubble plume is numerically simulated using the semi-Lagrangian–Lagrangian (semi-L–L) approach. The approach is composed of a vortex-in-cell method for the liquid phase and a Lagrangian description of the gas phase.

First, a new phenomenon of fluid dynamics was discovered. The bubbly flow enters a transition state with the meandering motion of the bubble plume after the early stable stage. A vortex structure in the form of vortex rings is formed because of the inhomogeneous bubble distribution and the fluid-surface effects. The vortex structure of the flow deforms as three-dimensionality appears in the flow before the flow fully develops. Second, the superior abilities of the semi-L–L approach to analyze the vortex structure of the flow and supply physical details of bubble dynamics were demonstrated in this investigation.

The semi-L–L approach is applied to the simulation of the gas–liquid two-phase flows.

One Commune One Product (OCOP) program, a rural economic development program in Vietnam, aims to empower local communities for sustainable social and economic welfare development, protect the environment and preserve tradition. This study aims to employ this program associated with tourism to support small family businesses in rural areas cost-effectively.

This study used the geographic location mapping method to design tourist routes that connect tourism resources with OCOP producers. A stakeholder approach was employed to identify suggested practical works that need to be implemented while developing this tourism initiative.

Four rural districts of Bac Giang Province, a northern province in Vietnam known as the place of various indigenous people live and traditional craft villages. Many cultural and historical tourist sites have been chosen as sample areas for this study. By using Google map, based on the Bac Giang Tourist Map and a list of recognized OCOP products in Bac Giang Province, main tourist sites (16 locations) and small family businesses (known as cooperatives and households) that have OCOP products (17 places) in the four districts have been identified. Four notable tourist routes have been formed to propose four thematic tours (two 1-day tours and two 2 days-1 night homestay tours). Suggestions for related stakeholders to ensure the sustainability of this initiative are provided.

This study is supposed to be a model of promoting small family businesses through OCOP programs and tourism activities in a sustainable way in Vietnam. The outcome of this study is in line with the stakeholder theory emphasizing the systematic connection of various stakeholders such as employees, suppliers, local communities, government agencies and others towards complex business sustainability. The results of the study cannot conclude the small family businesses in Vietnam because it adopts geographic location mapping alone. Moreover, this study focused on OCOP programs only. Future research can use other methods of primary data collection, especially from tourists' perspectives. Data triangulation can be done to explore and verify the tourist routes that have been formed according to the four thematic tours proposed. Future research could also compare hotels managed by family businesses with non-family businesses.

This study is supposed to be a model of promoting small family businesses through OCOP programs and tourism activities in a sustainable way in Vietnam.

“The world needs science, science needs women” is the message given by UNESCO in the program for the development of women in science” (UNESCO, 2017). In Vietnam, women’s participation and achievements in scientific research is considered a great and important resource for industrialization and modernization. Even so, are there gender differences in scientific achievement in the social science research institutes in Vietnam? What factors influence the scientific achievement of female social researchers? The answers will be based on data from a 2017 survey with a sample of 756 researchers, of which 77.6% were female. The survey was conducted by the Vietnam Academy of Social Sciences, a leading, ministry-level national center for the social sciences in Vietnam. This chapter analyzed the scientific achievements of researchers through their position as principal investigators of research projects and their publications, and factors that may impact this. Bivariate and multivariate analyses of factors that may affect the scientific achievement of researchers found that gender differences in academic achievement in the social sciences in Vietnam was still prevalent. Female researchers’ scientific achievements were lower than those of their male counterparts. The contribution to science of Vietnamese female researchers was limited by many different factors; the most important were the academic rank of the researchers and gender stereotype that considered housework the responsibility of women.

This chapter provides information on the development of Vietnamese education under the influence of global forces based on the analysis of relevant education research and policies using Wolhuter’s frameworks. In the process of coming up with ways to develop education in the face of different influences of globalization, besides having reactions with patterns commonly found in countries around the world, Vietnam also has responses that reflect its own political, sociocultural and economic characteristics. The state still plays a controlling role in education at all levels and many culture-related features that have existed throughout the country’s history have hardly changed, namely aspects related to teachers, learners and teaching and learning methods. To sustain its education in the globalized era, Vietnam must make more efforts in various aspects such as the link between education and employment, the logic of education objectives, the feasibility and appropriateness of curricula, quality of education, especially of higher education and equality in education for underprivileged groups.

This chapter explores the influences of Vietnamese culture coupled with national policies on gender equality on academic women’s advancement into senior leadership positions.

In-depth interviews with 20 mid-level women leaders and five top-level leaders were conducted at four different higher education institutions in the Mekong Delta (MD) in southern Vietnam. In addition, document analysis and participant observations contributed to the overall analysis, which allowed for the cross-check of data from multiple sources to investigate the participants’ understanding, perception, conceptualization, and interpretation of their experiences of advancing in their careers.

Findings show that there is a large gap between the policies and gender practices. Gender equality does not exist in reality, regardless of tremendous efforts from the Vietnamese government and policy makers to ensure it in all spheres of life. Additionally, patriarchal hierarchy remains dominant in the institutional administrative system, and Vietnamese Confucian ideology continues to confine and adversely affect both men’s and women’s perceptions of women’s social roles, status, and forms of social participation. Nevertheless, academic women still develop professionally and find their own ways to advance to a few key leadership positions at their institutions.

The sample of this study is limited to academic women in the MD in Vietnam. Future research should include more women and universities and colleges, from not only the southern part but also other regions of Vietnam. Further, international and comparative studies should be conducted to see differences in experiences of academic women from several Southeast Asian countries as they move up their career ladder.

Because there have not been any empirical studies about women and leadership in academia in the MD, this study serves as a resource and foundation for improving gender policies and practices as well as future research on this topic and gender issues of colleges and universities in Vietnam.

Building on my earlier work (Dang, 2007, 2008), this chapter provides an updated review of the private tutoring phenomenon in Vietnam including the reasons, scale, intensity, form, cost, and legality of these classes. In particular, this chapter offers a comparative analysis of the trends in private tutoring between 1998 and 2006 using all available data.

This chapter analyzes data from different sources, including (i) the 2006 Vietnam Household Living Standards Measurement Survey (VHLSS), (ii) the 1997–1998 Vietnam Living Standards Measurement Survey (VLSS), (iii) the 2008 Vietnam Household Testing Survey (VHTS), and (iv) local press in Vietnam. Quantitative methods are used.

Several (micro-)correlates are examined that are found to be strongly correlated with student attendance at tutoring, including household income, household heads’ education and residence areas, student current grade level, ethnicity, and household sizes. In particular, I focus on the last three variables that received little attention in the previous literature on the determinants of tutoring.

This chapter provides an updated and systematic review of the private tutoring phenomenon in Vietnam. Findings are highly relevant to the ongoing debates on private tutoring among all stakeholders in Vietnam, as well as policymakers/researchers in other countries. Suggestions are proposed on current gaps in the literature for future research.

The purpose of this study is to review the role of knowledge-sharing and its association with the Theory of Planned Behavior (TPB). TPB is the most used theory in understanding knowledge-sharing behavior in many contexts.

Based on the bibliometric approach, this study extracted and analyzed 229 journal articles on the Web of Science. In addition, two analyses (bibliographic coupling and co-word) were performed to provide science mapping in presenting the knowledge structure on the present and future research direction on knowledge-sharing and TPB.

The findings of this study suggest that two stand-out clusters are determinants and antecedents of knowledge-sharing behavior based on TPB and the role of the virtual platform and social media in facilitating knowledge-sharing among users.

This study will benefit researchers and scholars in studying individual behavioral traits underpinning TPB in achieving organizational excellence.

This study extends the findings of the previous review because of their limitations on methods. This study confirms the determinants of knowledge-sharing intention and behavior. However, this study suggests integrating TPB with other theories to provide more insights into knowledge-sharing behavior and use online and technology-based platforms to facilitate knowledge-sharing behavior.