Unemployment and Shadow Economy in ASEAN Countries

Toan Khanh Pham TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.11

The purpose of this study is to investigate the relationship between unemployment and shadow economy for 7 selected ASEAN countries using panel data from 2000–2017. This study uses a sample of 7 ASEAN countries including Cambodia, Indonesia, Malaysia, the Philippines, Singapore, Thailand, and Vietnam covering the 2000–2017 period. The stationarity of the variables is determined by Pesaran panel unit-root tests. The Westerlund panel co-integration technique is used to examine the long-run relationship among the variables. In addition, dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS) methods are also employed. The DOLS and FMOLS results indicate that unemployment acts as an important driver for the increase in the shadow economy. In addition, the study results also reveal that GDP per capita has a negative impact on the shadow economy. Moreover, government expenditure, bank credit, and inflation are positively related to the shadow economy. The empirical results indicate that the size of the shadow economy is boosted by unemployment in the selected ASEAN economies. In addition, it is also evident that an increase of GDP per capita in the sample countries results in a lower shadow economy. Besides, government expenditure, bank credit, and inflation play a crucial role in the shadow economy.

Salmonella enteritis: A Rare Cause of Adult Intussusception

Toan Pham,Domenic La Paglia,Meron Pitcher 대한대장항문학회 2017 Annals of Coloproctolgy Vol.33 No.5

Intussusception is a relatively rare condition in the adult population and is commonly secondary to a malignant process. Eight to twenty percent of cases of adult intussusception are thought to be idiopathic. In children, infection has been proven to precipitate intussusception in the absence of any other cause. We present a rare case of intussusception in a healthy adult patient secondary to salmonella infection and discuss infection as a potential explanation for a proportion of the cases of adult intussusception that are thought to be idiopathic. We recommend testing for infective causes of intussusception in adults when more common causes, such as malignancy, have been excluded.

The Effect of Knowledge Sharing and Innovativeness on Organizational Performance: An Empirical Study in Vietnam

Toan Khanh Pham TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.8

The emerging competitive environment in today’s global marketplace is one where businesses no longer compete with each other as autonomous, individual firms. Global, economic, and technological development pressure forces organizations to continually enhance their performance through knowledge sharing and innovativeness. The purpose of this paper is to explore the moderating role of knowledge sharing and the mediating role of innovativeness in the relationship between transformational leadership and organizational performance. The data was collected from 389 employees in Vietnamese industrial enterprises through a questionnaire survey. The information was then analyzed by explanatory factor analysis (EFA) confirmatory factor analysis (CFA) as well as structural equation modeling (SEM). The results show that the mediating role of innovativeness and the moderating role of knowledge sharing in the relationship between transformational leadership and performance, are supported. Organizations may reap the benefits of an innovative workforce by selecting, nurturing transformational leaders. This study contributes to the field of human resources management, particularly leadership, by exploring the role of transformational leadership. Moreover, this is the first study to test the moderating role of knowledge sharing and the mediating role of innovativeness in the relationship between transformational leadership and the organizational performance.

Reliable operation of a nanogenerator under ultraviolet light <i>via</i> engineering piezoelectric potential

Pham, Thanh Toan,Lee, Keun Young,Lee, Ju-Hyuck,Kim, Kwon-Ho,Shin, Kyung-Sik,Gupta, Manoj K.,Kumar, Brijesh,Kim, Sang-Woo The Royal Society of Chemistry 2013 Energy & environmental science Vol.6 No.3

<P>It is essential to stabilize and enhance the power output performance of piezoelectric nanogenerators (NGs) in order to use them as a sustainable power source for wireless sensors, microelectronics, and optoelectronic devices. Here, we report a facile route to stabilize and maximize the output performance of a zinc oxide (ZnO) nanorod (NR)-based NG in the presence of ultraviolet (UV) light by reducing the piezoelectric potential screening effect caused by the free electrons in the ZnO NRs <I>via</I> surface passivation. We experimentally and theoretically investigated the piezoelectric potential drop in the ZnO NR-based NG due to the piezoelectric potential screening effect. A simple thermal annealing treatment was applied to the pristine ZnO NRs in air atmosphere to stabilize the output performance of the NG even in the presence of UV light. The piezoelectric output voltage from the surface-passivated NG was approximately 25 times higher than that from the NG with no passivation under UV light illumination.</P> <P>Graphic Abstract</P><P>A facile route to stabilize and maximize the output performance of a ZnO nanorod-based piezoelectric nanogenerator in the presence of ultraviolet light by reducing the piezoelectric potential screening effect caused by the free electrons in the nanorods is reported. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2ee23980a'> </P>

Treatment efficiency of a combination of alternative technologies in removing pollutants from pesticide containing wastewater

Toan Van Pham,Vinh Mai Phuoc,Dung Van Nguyen,Jiro Koyama 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.6

Pesticide containing wastewater is concerned due to their toxicity to human health and the environment, and therefore, is attracted much attention by public communities and scientists. This type of wastewater can be treated by conventional treatment methods including physical, chemical, biological methods and so on. Unfortunately, the efficiency of these methods are mostly undesired as expectation because they cannot completely remove toxic organic pollutants from wastewater. In this study, an experiment on laboratory scale model of cold plasma technology, a well-known water treatment method in recent decades, was performed to assess its efficiency on removing pesticide fenobucarb from the wastewater. Furthermore, another experiment on laboratory scale model of the cold plasma combined with coagulation/flocculation and ion exchange process was implemented to assess the efficiency of these combination and each process as well on treatment of pesticide containing wastewater. Experimental results demonstrated that the model of technologies combined was high effective in removing organic pollutants from wastewater. However, the specific efficiency of cold plasma technology in treating wastewater was low. Treatment time, energy supply and wastewater characteristics are the factors which are necessary to be further studied for cold plasma technology application.

Treatment efficiency of a combination of alternative technologies in removing pollutants from pesticide containing wastewater

Toan Van Pham,Vinh Mai Phuoc,Dung Van Nguyen,Jiro Koyama 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.6

Pesticide containing wastewater is concerned due to their toxicity to human health and the environment, and therefore, is attracted much attention by public communities and scientists. This type of wastewater can be treated by conventional treatment methods including physical, chemical, biological methods and so on. Unfortunately, the efficiency of these methods are mostly undesired as expectation because they cannot completely remove toxic organic pollutants from wastewater. In this study, an experiment on laboratory scale model of cold plasma technology, a well-known water treatment method in recent decades, was performed to assess its efficiency on removing pesticide fenobucarb from the wastewater. Furthermore, another experiment on laboratory scale model of the cold plasma combined with coagulation/flocculation and ion exchange process was implemented to assess the efficiency of these combination and each process as well on treatment of pesticide containing wastewater. Experimental results demonstrated that the model of technologies combined was high effective in removing organic pollutants from wastewater. However, the specific efficiency of cold plasma technology in treating wastewater was low. Treatment time, energy supply and wastewater characteristics are the factors which are necessary to be further studied for cold plasma technology application.

Critical Factors Affecting Masks Purchasing Intention of Consumers During COVID-19 Pandemic: An Empirical Study in Vietnam

Toan Khanh Pham TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

An effective measure to prevent the spread of COVID-19 is wearing masks in public places. This solution is highly recommended in many countries all over the world. The objective of this study is to identify the antecedents of citizens’ intention to purchase masks during the COVID-19 pandemic. Based on the theory of planned behavior (TPB), the current study analyzes attitudes toward mask-purchasing, subjective norms, and perceived behavioral control, to assess their impact on intention to purchase masks. In total, six variables are examined: attitude toward mask-wearing, subjective norms, perceived behavioral control, perceived severity, perceived susceptibility, and the intention to wear masks. Data are collected from 243 respondents in Ho Chi Minh City, Vietnam. They were processed through by factor analysis and multiple regressions. The results report that all three factors positively affect citizens’ intention to buy masks in the following ascending order: Attitude toward mask-purchasing, subjective norms, and perceived behavioral control. Our study is the first research that applies TPB to investigate citizens’ intention to purchase masks to during the COVID-19 pandemic. Moreover, this study provides guidelines to the Vietnamese public managers to combat COVID-19 through the purchase of masks. Shopkeepers would be well advised to observe the intentions of consumers toward masks.

Impact of Servant Leadership on Public Service Motivation of Civil Servants: Empirical Evidence from Vietnam

Toan Khanh Pham TRAN,Truc Trung TRUONG 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4

Servant leadership has been noticeable in the last decade in the leadership literature on account its focus on serving others first. The target of servant leadership is not the organization, but rather the followers and their development and also the ability to motivate others to become servant leaders. Serving leadership has been recognized as a leadership philosophy that addresses ethical concerns, which is linked to ethical leadership. This study aims to investigate the relationship between dimensions of servant leadership and public service motivation of civil servants. Data were collected from civil servants working in public organizations at district level in Ho Chi Minh City of Vietnam through survey forms. The research hypotheses are tested by factor analysis and regression. The results report that 7 dimensions of servant leadership positively affect public service motivation in the following ascending order: Empowerment, standing back, forgiveness, humility, integrity, accountability, and courage. On the other hand stewardship has an insignificant impact on the role of leading and supervising. Our study contributes to the existing literature on servant leadership as well as public service motivation by throwing light onto a so-far neglected transitional country like Vietnam. Thereby, this study proposes a number of implications for the leaders to improve leadership style to enhance public service motivation of civil servants.

How Social Capital Mediates the Impact of Job Crafting on Job Performance: Evidence from Vietnamese Industrial Enterprises

Toan Khanh Pham TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.7

Job crafting refers to changes that individuals make in their work to achieve their preferences and needs. Contingent on the social exchange theory, the aim of this study is to explore the relationship between job crafting and job performance. In addition, the study examines the mediating effect of social capital in the relationship between job crafting and job performance. The data was collected from 387 employees in Vietnamese industrial enterprises through a questionnaire survey using both qualitative and quantitative methods. The information was then analyzed by explanatory factor analysis (EFA) confirmatory factor analysis (CFA) as well as structural equation modeling (SEM). The results show that all three dimensions of job crating positively affect job performance and that social capital plays a mediating role in that relationship. This study contributes to the field of human resources management, particularly job crafting, by examining different dimensions of job crafting that impacts job performance. Moreover, this is the first study to test the mediating role of social capital on the relationship between job crafting and job performance. These insights may help the organizational managers to encourage beneficial job crafting.

A review of anaerobic digestion systems for biodegradable waste: Configurations, operating parameters, and current trends

Dinh Pham Van,Takeshi Fujiwara,Bach Leu Tho,Pham Phu Song Toan,Giang Hoang Minh 대한환경공학회 2020 Environmental Engineering Research Vol.25 No.1

With benefits to the human health, environment, economy, and energy, anaerobic digestion (AD) systems have attracted remarkable attention within the scientific community. Anaerobic digestion system is created from (bio)reactors to perform a series of bi-metabolism steps including hydrolysis/acidogenesis, acetogenesis, and methanogenesis. By considering the physical separation of the digestion steps above, AD systems can be classified into single-stage (all digestion steps in one reactor) and multi-stage (digestion steps in various reactors). Operation of the AD systems does not only depend on the type of digestion system but also relies on the interaction among growth factors (temperature, pH, and nutrients), the type of reactor, and operating parameters (retention time, organic loading rate). However, these interactions were often reviewed inadequately for the single-stage digestion systems. Therefore, this paper aims to provide a comprehensive review of both single-stage and multi-stage systems as well as the influence of the growth factors, operating conditions, and the type of reactor on them. From those points, the advantages, disadvantages, and application range of each system are well understood.