Research on Management Accounting of Fixed Assets at Vinacomin, Vietnam

The research was conducted to find out about the current situation of management accounting for fixed assets at enterprises of Vietnam National Coal and Mineral Industries Holding Corporation (Vinacomin), Vietnam. Data was collected through interviews with directors, chief accountants, fixed-asset accountants, heads of other departments in the surveyed enterprises, auditors, experts in accounting and auditing field. Analytical procedures are employed in this research. The results indicate that the management and use of fixed assets in enterprises of Vinacomin are still inefficient; applying the improper depreciation methods for each type of fixed assets; most enterprises have not yet developed and analyzed the system of indicators to assess investment situation, technical status and efficiency of using fixed assets. Keywords: Management accounting, fixed assets, efficient use, Vinacomin. DOI: 10.7176/JRDM/61-04 Publication date: November 30th 201

Integrated Exploitation of Rainwater and Groundwater: A Strategy for Water Self-Sufficiency in Ca Mau Province of the Mekong Delta

Groundwater sources have been exploited excessively for numerous purposes worldwide, leading to increasingly severe depletion. However, the replenishment of groundwater sources has not usually been a focus in economically and socially underdeveloped countries and regions. In coastal provinces of the Vietnamese Mekong Delta (VMD), rural areas are facing difficulties in accessing fresh water due to shortages from the water supply plant and excessive use of groundwater, highlighting an urgent need for sustainable development solutions. Our study first conducted interviews with 200 households in Ca Mau Province of the VMD to identify the current situation and the challenges and obstacles of rainwater harvesting and to find sustainable and proactive solutions. We then analyzed daily rainfall data from 10 meteorological stations to construct four scenarios of the water balance method: (i) potential rainwater harvesting based on existing roof area; (ii) optimal scale of storage tank and catchments for different levels of water usage; (iii) tank scale utilizing rainwater entirely during the rainy season and basic needs during the dry season; and (iv) integrated water supply between rain and groundwater. The results showed that using rainwater entirely for domestic water supply requires large storage tank capacities, making these scenarios difficult to achieve in the near future. Our research introduces a novel integrated water supply approach to storing rain and groundwater that has demonstrated high effectiveness and sustainability. With existing tank capacities (0.8 m3 per person), rainwater could only meet over 48% (14 m3 per year) of the water demand while requiring 14.8 m3 of additional groundwater extraction. With a tank capacity of 2.4 m3 per person, ensuring rainwater harvesting meets basic demand, harvested rainwater could satisfy 64% of the demand, with artificial groundwater supplementation exceeding 1.79 times the required extraction, while excess rainwater discharge into the environment would be minimal. Our research results not only provide potential solutions for rainwater and groundwater collection to supplement sustainable domestic water sources for Ca Mau but also serve as an example for similar regions globally

Insights into Molten Salts Induced Structural Defects in Graphitic Carbon Nitrides for Piezo-Photocatalysis with Multiple H2O2 Production Channels

Recently, the production of hydrogen peroxide (H2O2) from water (H2O) and oxygen (O2) in the presence of graphitic carbon nitrides (g-C3N4) via a piezo-photocatalytic process has considerably ignited global interest in achieving sustainability. To fabricate porous g-C3N4, soft templates are frequently employed, leading to structural modifications originating from heteroatoms. However, many recent reports have ignored the roles of trace quantity of heteroatoms. Hence, to understand the impacts of the mentioned factors, we fabricated g-C3N4 containing oxygen and halogen atoms in the structures for piezo-photosynthesis of H2O2. Based on our analyzed results, oxygen atoms might be inserted into g-C3N4 in-plane structures, while halogen atoms tend to become intercalated between g-C3N4 layers. Furthermore, the presence of ammonium molten salts during the synthesis alters the concentration of mono and cluster vacancies of carbon and nitrogen in the materials. These defective contributions would meaningfully accelerate catalytic performance by providing trapping states. From the mechanistic view, different reduction and oxidation channels would play a pivotal role in generating H2O2. Thus, this study highlights the importance of modulating in-plane and out-of-plane structures of g-C3N4, benefiting catalytic properties under simultaneous irradiation

Promoted Hydrogen Peroxide Production from Pure Water on g-C3N4 with Nitrogen Defects Constructed through Solvent-Precursor Interactions: Exploring A Complex Story in Piezo-Photocatalysis

Hydrogen peroxide (H2O2) production via oxygen (O2) reduction reaction (ORR) in pure water (H2O) through graphitic carbon nitrides (g-C3N4)-based piezo-photocatalysts is an exciting approach in many current studies. However, the low Lewis-acid properties of g-C3N4 limited the catalytic performance because of the low O2 adsorption efficacy. To overcome this challenge, we utilized the interaction of g-C3N4 precursors with various solvents to synthesize g-C3N4, possessing multiple nitrogen-vacant species via thermal shocking polymerization. Our results suggest that the lack of nitrogen in g-C3N4 and the incident introduction of oxygen-functional groups enhance the Lewis acid-base interactions and polarize the g-C3N4 lattices, leading to the enormous enhancement, roughly 7 times from the optimal samples compared to pristine g-C3N4 in pure water via piezo-photocatalysis. Meanwhile, we also observed the correlation between the charge separation kinetic and the crystalline degree of the synthesized materials, which can elucidate how the nitrogen defects impacted the catalytic outcomes. Furthermore, the catalytic mechanisms were thoroughly studied, with the formation of H2O2 proceeding via radical and water oxidation pathways, in which the roles of light and ultrasound were carefully investigated. Thus, our findings not only reinforce the potential view of metal-free photocatalysts, accelerating the understanding of g-C3N4 working principles to generate H2O2 based on the oxygen reduction and water oxidation reactions, but also propose a facile one-step way for fabricating highly efficient and scalable photocatalysts to produce H2O2 without using sacrificial agents, pushing the practical application of in-situ solar H2O2 toward real-world scenarios