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1.
PLoS One ; 19(5): e0303491, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38768167

RESUMO

In the digital age, firms should continually innovate and adapt to remain competitive and enhance performance. Innovation and adaptation require firms to take a holistic approach to their corporate structuring to ensure efficiency and effectiveness to stay competitive. This study examines how corporate restructuring impacts firm performance in Vietnam. We then investigate the moderating role of digital transformation in the corporate restructuring-firm performance nexus. We use content analysis, with a focus on particular terms, including "digitalization," "big data," "cloud computing," "blockchain," and "information technology" for 11 years, from 2011 to 2021. The frequency index from these keywords is developed to proxy the digital transformation for the Vietnamese listed firms. A final sample includes 118 Vietnamese listed firms with sufficient data for the analysis using the generalized method of moments (GMM) approach. The results indicate that corporate restructuring, including financial, portfolio, and operational restructuring, has a negative effect on firm performance in Vietnam. Digital transformation also negatively affects firm performance. However, corporate restructuring implemented in conjunction with digital transformation improves the performance of Vietnamese listed firms. These findings largely remain unchanged across various robustness analyses.


Assuntos
Comércio , Vietnã , Humanos , Tecnologia da Informação
2.
PLoS One ; 17(5): e0267328, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35544549

RESUMO

Understanding the determinants of the shadow economy plays a vital role in formulating policies for economic growth and development, particularly for the Southeast Asian countries-a new economic force for a global economy. The key drivers of a shadow economy, such as institutional quality, taxation, government expenditure, are widely examined. However, the effect of national intellectual capital, which affects macroeconomic indicators, on the shadow economy has largely been ignored in the existing literature. Our paper examines this critical link and its causality relationship for eight Southeast Asian countries from 2000 to 2017. This paper uses the dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS), which allow cross-sectional dependence and slope homogeneity in panel data analysis. Empirical findings from this paper indicate that national intellectual capital impacts negatively and significantly the shadow economy size. This finding implies that enhancing national intellectual capital reduces the shadow economy size. These two forces lead to enhanced economic growth. Our Granger causality tests confirm a bi-directional relationship between national intellectual capital and the shadow economy. As a result, policies targeted to reduce the shadow economy size can now include the accumulation of national intellectual capital, particularly for Southeast Asian Countries.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Estudos Transversais , Políticas , Impostos
3.
J Environ Sci (China) ; 69: 52-60, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29941269

RESUMO

The effects of C/N ratio of a nitrate-containing wastewater on nitrate removal performed by autohydrogenotrophic bacteria as well as on the morphological parameters of floc such as floc morphology, floc number distribution, mean particle size (MPS), aspect ratio and transparency were examined in this study. The results showed that the nitrate reduction rate increased with increasing C/N ratio from 0.5 to 10 and that the nitrogen removal of up to 95% was found at the C/N ratios of higher than 5 (between 0.5-10). Besides, high C/N ratio values reflected a corresponding high nitrite accumulation after 12-hr operation, and a fast decreasing rate of nitrite in the rest of operational time. The final pH values increased with the C/N ratio increasing from 0.5 to 2.5, but decreased with the C/N ratio increasing from 2.5 to 10. There were no significant changes in floc morphology with the MPSs ranging from 35 to 40µm. Small and medium-sized flocs were dominant in the sludge suspension, and the number of flocs increased with the increasing C/N ratios. Furthermore, the highest apparent frequency of 10% was observed at aspect ratios of 0.5 and 0.6, while the transparency of flocs changed from 0.1 to 0.7.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Carbono/análise , Nitratos , Nitrogênio/análise , Águas Residuárias/estatística & dados numéricos
4.
J Environ Sci (China) ; 63: 50-57, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29406116

RESUMO

In recent years there has been an increasing interest in the use of autohydrogenotrophic bacteria to treat nitrate from wastewater. However, our knowledge about the characteristics of extracellular polymeric substances (EPS) releasing by these activities is not yet very advanced. This study aimed to investigate the change in EPS compositions under various pH values and hydrogen flow rates, taking into consideration nitrogen removal. Results showed that pH7.5 and a hydrogen flow rate of 90mL/min were the optimal operating conditions, resulting in 100% nitrogen removal after 6hr of operation. Soluble and bound polysaccharides decreased, while bound proteins increased with increasing pH. Polysaccharides increased with increasing hydrogen flow rate. No significant change of bound proteins was observed at various hydrogen flow rates.


Assuntos
Polissacarídeos Bacterianos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Bactérias , Hidrogênio/química , Concentração de Íons de Hidrogênio , Nitratos/química
5.
Electrophoresis ; 36(13): 1485-92, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25785901

RESUMO

Dielectrophoresis (DEP) has been applied widely in bacterial manipulation such as separating, concentrating, and focusing. Previous studies primarily focused on the collective effects of DEP force on the bacterial population. However, the influence of DEP force on the swimming of a single bacterium had not been investigated. In this study, we present a model to analyze the effect of DEP force on a swimming helically flagellated bacterium, particularly on its swimming direction and velocity. We consider a simple DEP force that acts along the X-direction, and its strength as well as direction varies with the X- and Y-positions. Resistive force theory is employed to compute the hydrodynamic force on the bacterium's flagellar bundle, and the effects of both DEP force and rotational diffusion on the swimming of the bacterium are simultaneously taken into consideration using the Fokker-Planck equation. We show the mechanism of how DEP force alters the orientation and velocity of the bacterium. In most cases, the DEP force dominantly influences the orientation of the swimming bacterium; however, when the DEP force strongly varies along the Y-direction, the rotational diffusion is also responsible for determining the bacterium's reorientation. More interestingly, the variance of DEP force along the Y-direction causes the bacterium to experience a translational velocity perpendicular to its primary axis, and this phenomenon could be utilized to focus the bacteria. Finally, we show the feasibility of applying our findings to achieve bacterial focusing.


Assuntos
Bactérias/efeitos da radiação , Movimento Celular/efeitos da radiação , Eletroforese/métodos , Eletricidade
6.
Bioresour Technol ; 166: 389-94, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24929810

RESUMO

Membrane fouling precludes the widespread application of membrane filtration system from treating wastewater and drinking water, and occurs even under sub-critical flux operations. Hence the characteristics and behavior of membrane foulants should be thoroughly investigated, so as to find ways to reduce membrane fouling in membrane bioreactors. The purpose of this study is to compare the membrane fouling potential at different sub-critical flux operations and for different hydrophobic/hydrophilic membranes, and to investigate the vertical distribution of membrane foulants in a cake layer. Results showed that higher fouling propensity which occurred under 80% of critical flux of hydrophilic membrane was associated with the soluble fraction of proteins and polysaccharides, compared with 60% of critical flux. The cell-bound components were dominant under hydrophobic membrane operation. The highest concentration of proteins and polysaccharides was found between 40% and 80% of the depth of the cake layer.


Assuntos
Incrustação Biológica , Reatores Biológicos , Purificação da Água/métodos , Membranas Artificiais , Águas Residuárias/química
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