Removal of inorganic nutrient and organic carbon from wastewater of Binh Dien market using the green alga Chlorella sp.

Traditional markets play a major role in socio-economics and constitutes a significant aspect of Vietnamese culture. However, wastewater streams discharged from the markets are generally characterized by a lot of inorganic nutrients and organic substances originated from fresh food processing units. They could lead to serious water contamination if discharged without proper treatment. This study applied microalgae Chlorella sp. for eliminating inorganic nutrients (NO3--N, NH4+-N and PO43--P) and organic carbon (Chemical oxygen demand-COD) from wastewater of the Binh Dien market. The removal efficiencies reached for NH4+-N > 86%, for NO3--N > 72%, and for PO43--P > 69%, respectively, at algal density of 49 x 104 cell mL-1, and for COD > 96% at algal density of 35 x 104 cell mL-1 after five cultivating days. The effluence satisfied the Vietnamese standard, column B, of the National technical regulation on industrial wastewater (QCVN 40:2011/BTNMT). The results demonstrated that the culture system composed of green algal Chlorella sp. could be a potential candidate for the removal of nutrients and organic carbon by a wastewater treatment process from the Binh Dien market

Modelling and Experimental Validation of a VNT Turbocharger for Improving Performances of a Marine Diesel Generator Engine

This paper presents modelling and experimental validation for improving the performances of a marine diesel generator engine. Based on the diesel engine theory, the laws of conservation of energy, and the principle of movement of flow through turbocharger nozzle, a mathematical model of a real turbocharged engine was built, concentrating on the mathematic model of flow through nozzles. This model is simulated by Matlab/Simulink program, the results of simulation showed the relationships between the engine and the turbocharger, the turbine and the compressor, and between the nozzles and the turbocharger. The experiments were carried out to validate this model, the errors between the simulation and measure were acceptable. The measure and simulation results also determined that at the low load conditions (≤50% load) engine performances can be improved by adjusting nozzle opening degree (from fully opening to 90% and 80% opening)

Application of Regional Ocean Modeling System for hydrodynamics in Binh Cang-Nha Trang Bay, Vietnam

Based on the data collected at the Cau Da station, the Regional Ocean Modeling System (ROMS) is applied for hydrodynamics (e.g. circulation and temperature-salinity) in Binh Cang - Nha Trang Bay, Vietnam. The results present the several cases of hydrodynamic regimes in the Bay during two mainly monsoon seasons (northeast and southwest monsoons). The clearly hydrodynamic regime occurs in the bay due to the impacts of rivers and monsoon conditions. These changes could be contributed to the hydrodynamic systems and water exchanges, that support basic scientific information for sustainable development of Binh Cang - Nha Trang bay

A long range, energy efficient internet of things based drought monitoring system

The climate change and global warning have been appeared as an emerging issue in recent decades. In which, the drought problem has been influenced on economics and life condition in Vietnam. In order to solve this problem, in this paper, we have designed and deployed a long range and energy efficient drought monitoring based on IoT (Internet of Things) for real time applications. After being tested in the real condition, the proposed system has proved its high dependability and effectiveness. The system is promising to become a potential candidate to solve the drought problem in Vietnam

Integrating susceptibility maps of multiple hazards and building exposure distribution: A case study of wildfires and floods for Quang Nam province, Vietnam

Natural hazards have serious impacts worldwide on society, economy and environment. In Vietnam, throughout the years, natural hazards have caused significant loss of lives as well as severe devastation to houses, crops, and transportation. This research presents a new approach for multi-hazard (floods and wildfires) exposure estimates using machine learning models, Google Earth Engine, and spatial analysis tools for a typical case study, Quang Nam province in Central Vietnam. A geospatial database is built for multiple hazard modelling, including an inventory of climate-related hazards (floods and wildfires), topography, geology, hydrology, climate features (temperature, rainfall, wind), land use, and building data for exposure assessment. The susceptibility of each hazard is first modelled and then integrated into a multi-hazard exposure matrix to demonstrate a hazard profiling approach for multi-hazard risk assessment. The results are explicitly illustrated for floods and wildfire hazards and the exposure of buildings. Susceptibility models using the random forest approach provide model accuracy of AUC = 0.882 and 0.884 for floods and wildfires, respectively. The flood and wildfire hazards are combined within a semi-quantitative matrix to assess the building exposure to different hazards. Digital multi-hazard exposure maps of floods and wildfires aid the identification of areas exposed to climate-related hazards and the potential impacts of hazards. This approach can be used to inform communities and regulatory authorities on where to develop and implement long-term adaptation solutions

Piezoelectric responses of PVDF-KBT electrospun nanocomposite fibres via nanoscale mapping

peer reviewedThe piezoelectric properties of polyvinylidene fluoride (PVDF) and K0·5Bi0·5TiO3 (KBT) electrospun composite nanofibers were studied in view of their application for Piezoelectric generator (PEG) devices. The orientation of the polar β-phase throughout the PVDF/KBT nanofibers was investigated at the nanoscale, revealing a maximum β-phase content of 67%. Remarkably enhanced piezoelectric responses were observed in the PVDF-KBT composite, supported by comprehensive analyses including local hysteresis loops piezoresponse mapping and advanced mapping AFM-based techniques. The PVDF/KBT nanofiber-based PEG demonstrated consistent performance, with an output voltage of 16 V, a current of 0.85 μA/cm2, and a power density of 13.6 μW/cm2 at 107 Ω, showcasing its potential as a sustainable energy solution with the ability to recharge portable electronic devices

Straw Management Adoption Capacity in Dong Thap Province

The study aimed to evaluate the straw management adoption capacity in Dong Thap province. Key informant interview (KII) with district-level DARD officials in Dong Thap province were conducted to determine the straw management adoption capacity in Winter-Spring, Summer-Autumn, and Autumn-Winter season

Straw Management Adoption Capacity in Long An Province

The study aims to evaluate the straw management adoption capacity in Long An province. Key informant interview (KII) with district-level DARD officials in Long An province were conducted to determine the straw management adoption capacity in Winter-Spring, Summer-Autumn, and Autumn-Winter season