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Article
Publication date: 26 September 2019

Van Luc Nguyen, Tomohiro Degawa, Tomomi Uchiyama and Kotaro Takamure

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.

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 12
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 11 July 2019

Van Luc Nguyen, Tomohiro Degawa and Tomomi Uchiyama

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

Abstract

Purpose

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

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 11 February 2019

Van Luc Nguyen, Tomohiro Degawa and Tomomi Uchiyama

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

Abstract

Purpose

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

Design/methodology/approach

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-LL) approach. The approach is composed of a vortex-in-cell method for the liquid phase and a Lagrangian description of the gas phase.

Findings

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-LL approach to analyze the vortex structure of the flow and supply physical details of bubble dynamics were demonstrated in this investigation.

Originality/value

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

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

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Book part
Publication date: 21 September 2017

Ngoc Lan Thi Dang

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

Abstract

Purpose

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

Methodology/approach

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

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.

Research limitations

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.

Originality/value

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.

Details

Discourses on Gender and Sexual Inequality
Type: Book
ISBN: 978-1-78743-197-3

Keywords

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Book part
Publication date: 18 January 2014

Hai-Anh Dang

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

Out of the Shadows: The Global Intensification of Supplementary Education
Type: Book
ISBN: 978-1-78190-816-7

Keywords

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Article
Publication date: 17 May 2021

Le Dang Lang, Abhishek Behl, Nguyen Trung Dong, Yama Temouri and Nguyen Hong Thu

Coronavirus disease 2019 (COVID-19) has seriously affected the global economy. How agribusinessmen are overcoming this crisis is being noticed in emerging markets. Using…

Abstract

Purpose

Coronavirus disease 2019 (COVID-19) has seriously affected the global economy. How agribusinessmen are overcoming this crisis is being noticed in emerging markets. Using social capital to diversify agribusiness for getting more customers is a useful solution for the growth of agribusiness. However, there is a lack of evidence on the aggregate measurement scale of social capital and the influence of behavioral goals on the intention toward agribusiness diversification. Therefore, this study aims to develop an integrated measurement of social capital and investigate its effect on agribusiness diversification intention using the expanded theory of planned behavior (TPB).

Design/methodology/approach

A mixed-methods approach is used, including four in-depth interviews, three focus group discussions and two surveys. Structural equation modeling is applied to a sample of 484 respondents to test the proposed hypotheses.

Findings

The study shows the role of social capital in influencing the intention to diversify agribusiness under the premises of the resource-based view (RBV). The scale of social capital is also developed, which is the first integrated measurement of this asset. The findings contribute significantly to the existing knowledge of social capital, the TPB and diversifying agribusiness.

Originality/value

This is the first study to explore the comprehensive effect of the facets of social capital on behavioral intention through behavioral goals and determinants of the TPB under the premises of the RBV. The findings will help emerging economies, for example, Vietnam, where most farmers are family business owners or microscaled entrepreneurs in agriculture.

Details

Journal of Intellectual Capital, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1469-1930

Keywords

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Article
Publication date: 8 June 2021

Le Dang Lang, Abhishek Behl, Nguyen Trung Dong, Nguyen Hong Thu and Prem Prakash Dewani

The COVID-19 pandemic has badly affected the global economy. The use of social capital as a resource to diversify agribusiness to get more customers and improve the…

Abstract

Purpose

The COVID-19 pandemic has badly affected the global economy. The use of social capital as a resource to diversify agribusiness to get more customers and improve the agricultural supply chain is a considerable issue to explore. This study aims to develop a comprehensive measurement of social capital and examine its effect on the intention to diversify agribusiness. From a supply chain perspective, it uses theory of planned behavior (TPB) and resource-based view (RBV).

Design/methodology/approach

The study uses a mixed-methods approach. In-depth interviews, focus group discussions and surveys are used. Structural equation modeling on a sample of 465 respondents in Vietnam was employed to examine the hypothesized relationships.

Findings

An integrative measurement scale of social capital from an agricultural supply chain perspective is suggested. The study also shows significant causal relationships amongst social capital, motives, TPB's determinants and the intention to diversify agribusinesses in light of supply chain perspectives.

Originality/value

The study offers a significant contribution to the existing body of knowledge in the literature on social capital, motives, TPB, RBV and supply chain perspectives. The study was executed in Vietnam, where most farmers are smallholders, family business owners or micro-scale entrepreneurs in agriculture.

Details

The International Journal of Logistics Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0957-4093

Keywords

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Article
Publication date: 1 October 2005

Georgios I. Zekos

Globalisation is generally defined as the “denationalisation of clusters of political, economic, and social activities” that destabilize the ability of the sovereign State…

Abstract

Globalisation is generally defined as the “denationalisation of clusters of political, economic, and social activities” that destabilize the ability of the sovereign State to control activities on its territory, due to the rising need to find solutions for universal problems, like the pollution of the environment, on an international level. Globalisation is a complex, forceful legal and social process that take place within an integrated whole with out regard to geographical boundaries. Globalisation thus differs from international activities, which arise between and among States, and it differs from multinational activities that occur in more than one nation‐State. This does not mean that countries are not involved in the sociolegal dynamics that those transboundary process trigger. In a sense, the movements triggered by global processes promote greater economic interdependence among countries. Globalisation can be traced back to the depression preceding World War II and globalisation at that time included spreading of the capitalist economic system as a means of getting access to extended markets. The first step was to create sufficient export surplus to maintain full employment in the capitalist world and secondly establishing a globalized economy where the planet would be united in peace and wealth. The idea of interdependence among quite separate and distinct countries is a very important part of talks on globalisation and a significant side of today’s global political economy.

Details

Managerial Law, vol. 47 no. 5
Type: Research Article
ISSN: 0309-0558

Keywords

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Article
Publication date: 17 March 2020

Huy Van Nguyen, Lee Diane and David Newsome

This paper aims to explore the Kinh and ethnic stakeholders’ participation and collaboration in tourism planning in Sapa, Vietnam.

Abstract

Purpose

This paper aims to explore the Kinh and ethnic stakeholders’ participation and collaboration in tourism planning in Sapa, Vietnam.

Design/methodology/approach

The primary data collection involved semi-structured interviews with 33 key tourism stakeholders, and data were analyzed using qualitative content analysis.

Findings

The findings reveal that in terms of participation and collaboration in tourism planning, there is little difference between the Kinh and ethnic groups. Tourism planning is viewed as a top-down approach, and both groups at the community level have very limited participation in tourism planning activities. However, at the on-site management level, there are opposing views between high (Kinh) and low (ethnic) management levels about participation in tourism planning. Both groups recognize the need for interdependence regarding collaboration in tourism planning. They also share similar aspects in regard to facilitating and hindering their participation in tourism planning.

Research limitations/implications

The limitations of this study include the use of a qualitative method, which limited the number of respondents. Future research could benefit from the application of quantitative research methods to include a greater number of local tourism stakeholders.

Practical implications

This study contributes to a better understanding of tourism planning in the Vietnamese context and has some practical implications for destination management and policymaking.

Originality/value

This is the first study to investigate the perspectives of Kinh and ethnic groups in term of participation and collaboration in tourism planning in the Vietnamese context.

Details

International Journal of Culture, Tourism and Hospitality Research, vol. 14 no. 4
Type: Research Article
ISSN: 1750-6182

Keywords

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Article
Publication date: 30 November 2020

Padmi Nagirikandalage, Ben Binsardi, Kaouther Kooli and Anh Ngoc Pham

The purpose of this study is to investigate the resistance in management accounting practices (MAPs) in a developing economy in the manufacturing and service sectors in Vietnam.

Abstract

Purpose

The purpose of this study is to investigate the resistance in management accounting practices (MAPs) in a developing economy in the manufacturing and service sectors in Vietnam.

Design/methodology/approach

Data collection was carried out using survey questionnaires in Vietnamese language. The questionnaires were distributed to selected respondents from the manufacturing and service organisations in Vietnam. Textual structuralism was used to analyse different categories of data, i.e. survey questionnaires, photos and qualitative texts obtained from the literature.

Findings

The findings indicate that the usage of MAPs is more prevalent in the manufacturing sector than in the service sector. In addition, various traditional and contemporary MAPs are being used concurrently in Vietnam, which challenges the classical twofold dichotomy between mere socialism and mere neoliberalism.

Research limitations/implications

The textual and photographic structuralism is used in this study to analyse primary data (geography and society and time) in a static setting. Hence, it does not analyse the research phenomena in a dynamic equilibrium setting to view the development of the research phenomena over time. Further research could expand data collection to include longitudinal and dynamic settings.

Practical implications

MAPs can be implemented in economic systems ranging from command to capitalist systems. Although most countries in the world follow a mixed economic system, specific MAPs could be designed for a transitional economic system such as that of Vietnam. This affects both theorists and practitioners in Vietnam applying sustainable MAPs to boost a country's competitiveness during transition.

Originality/value

This study expands understanding of the conformity of MAPs in relation to economic systems under the Communist Party of Vietnam (CPV) – the ruling party of the Socialist Republic of Vietnam. Understanding the differences in the way these MAPs are utilised constitutes an essential area of the accounting discipline to advance MAPs in Vietnamese enterprises and progress theoretical development of sustainable MAPs.

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