Lowland technology international : the official journal of the International Association of Lowland Technology, Jun 1, 2006
This paper presents the development and application of a conjunctive water management model for l... more This paper presents the development and application of a conjunctive water management model for lowland catchments. The model incorporates a simulation model and a management model to simulate groundwater movement, ground consolidation and to search for the potential pumping amount of groundwater without violating physical and environmental constraints. The results reveal that groundwater levels in a coastal aquifer greatly vary in response to pumping. Consequently subsidence rapidly occurs throughout the area. The study also suggests that conjunctive water management can be used to improve water supply reliability, to reduce groundwater overdraft and land subsidence and to improve environmental conditions.
Physics And Chemistry Of The Earth, Parts A/b/c, Oct 1, 2019
The purpose of this study is to apply numerical modeling to assess the water quality in Cam and L... more The purpose of this study is to apply numerical modeling to assess the water quality in Cam and Lach Tray coastal estuaries. The wind re-analysis data from Weather Research and Forecasting (WRF) model were used to simulate wave and the hydrodynamic regimes with a definition of 14 km within the longitude range from 105 0 E to 120 0 E and latitude range from 5 0 to 22 0 in the study area. The calibration and validation results for the wind-wave, hydrodynamic regimes showed that the performance of 2D hydrodynamic model is extremely good with a Nash coefficient ranges from 0.89 to 0.92, an RMSE-observations standard deviation ratio (RSR) varies from 0.25 to 3.6 and a Percent bias (PBIAS) is from-4.2% to 0.2%. The calibrated 2D hydrodynamic model are combined with the Ecolab model to evaluate and simulate the spreading of water quality parameters (BOD, NH 4 + , and TSS). During the high tides, the tidal moves into the river, and therefore, the spread of water quality
A novel piston pin design is proposed for diesel engines having higher load capacity than current... more A novel piston pin design is proposed for diesel engines having higher load capacity than current pin designs. This shaped piston pin incorporates a stress-reducing profile with lubricant film thickness enhancing features on the surface. Three dimensional FEA models were built and are used to model the dynamic contact between the piston and connecting rod interfaces with a standard piston pin and the new piston pin design.
The dumping of dredge materials often raises concerns about the release of pollutants to the mari... more The dumping of dredge materials often raises concerns about the release of pollutants to the marine environment. Wind data from the Global Forecast System (GFS) model was used to simulate the wind-wave propagation from offshore in a two-dimensional (2D) model during September and October 2016. The calibration and validation of the 2D model showed a high conformity in both the phases and amplitude between the observed and simulated data. The 2D mud transport simulation results of three scenarios showed that the concentration of suspended material in the third scenario tested (scenario 3) was greater than 0.004 kg/m 3 in the low tide, spreading to a 9 km 2 area, and in the high tide, the concentration was 0.004 kg/m 3 in a 6 km 2 area. Finally, the results of 2D particle tracking (PT) showed changes in the seabed due to the concentration of dredged material, and its dump (approximately 180 days) increased from 0.08 m to 0.16 m in 2.85 ha. In scenario 3, the element block moved quite far-approximately 2.9 km-from the dredge position. Therefore, the simulation results were qualified, as the dredging position situated far from the sea is significantly affected by the direction and velocity of wave-wind in the dredging position.
The main objective of this paper is to forecast the integrated impacts of both climate change and... more The main objective of this paper is to forecast the integrated impacts of both climate change and land use changes on surface hydrology which is focused particularly on streamflow assessment under scenarios (A2, B1, and A1B) of climate change and land use change (2030, 2050, and 2080) in Nakdong basin by combination of both models as hydrology model (ArcSWAT) and land use change model (CA_Markov). The results indicated that the mean annual integrated impacts of climate change and land use change on streamflow in the future showed an increase tendency for all periods under scenarios A2, B1, and A1B. However, B1 scenario showed the highest of +3.97%, while A2 showed the lowest increase of +1.1%. However, the mean months of streamflow showed different changes that were forecasted large changes as an increase from +12 to +18% in months of Jan, Feb, Jul and Aug, while it showed a significant reduction from-9.0% to-19% in May and Oct for all periods under A2, B1, and A1B scenarios. Moreover, results were also to reveal that land use change and climate change both increased on the mean annual streamflow, but the impact of climate change was higher than that of land use change.
the molecular weight effects the diffusion of molecules in the interface of laminar flow form in ... more the molecular weight effects the diffusion of molecules in the interface of laminar flow form in a microfluidic channel. Two mixtures of PS with anisole and PEG were used to evaluate the molecular weight effect on the microfluidic separation. Also, the separation of a low molecular weight substance of anisole from the mixture with a high molecular weight substance of PS is proved experimentally. However, the separation of PEG from the mixture with PS remained difficulty. More information about diffusion in microfluidic channel and can be applied to polymer science and separation fields.
This paper presents methods to determine the value of water resource inventory indicators for Vie... more This paper presents methods to determine the value of water resource inventory indicators for Vietnam including total rainfall, total surface water amount, surface water quality, groundwater reserve and quality, exploitation and use of surface water and underground water, wastewater discharge into water sources, and economic values of water resources for the cases of full data, lack of data and no data. The application of water inventory for the Ba river basin shows that the average total annual rainfall in the basin is 1823 mm; the total annual average volume of surface water at Cung Son station is 7,973.63 million m 3 , the total amount of exploitation used for the main water users (for hydropower) is 6,085.49 million m 3. These obtained results are based on observed data and thus they have high reliability and can be used for water resource planning for this river basin. The methods determining inventory indicators presented in this paper can be used consistently for water resources inventory in Vietnam.
Physics and Chemistry of the Earth, Parts A/B/C, 2019
The purpose of this study is to apply numerical modeling to assess the water quality in Cam and L... more The purpose of this study is to apply numerical modeling to assess the water quality in Cam and Lach Tray coastal estuaries. The wind re-analysis data from Weather Research and Forecasting (WRF) model were used to simulate wave and the hydrodynamic regimes with a definition of 14 km within the longitude range from 105 0 E to 120 0 E and latitude range from 5 0 to 22 0 in the study area. The calibration and validation results for the wind-wave, hydrodynamic regimes showed that the performance of 2D hydrodynamic model is extremely good with a Nash coefficient ranges from 0.89 to 0.92, an RMSE-observations standard deviation ratio (RSR) varies from 0.25 to 3.6 and a Percent bias (PBIAS) is from-4.2% to 0.2%. The calibrated 2D hydrodynamic model are combined with the Ecolab model to evaluate and simulate the spreading of water quality parameters (BOD, NH 4 + , and TSS). During the high tides, the tidal moves into the river, and therefore, the spread of water quality
In 2011, an oil spill occurred off Lach Huyen port in the Northeast of Vietnam, due to vessels co... more In 2011, an oil spill occurred off Lach Huyen port in the Northeast of Vietnam, due to vessels collision. The results of collision caused pollution on wide area and surrounding areas. This paper was used MIKE 21 SA model to simulate oil spill transport with five scenarios. The results of simulation showed that spill trajectory and slick area depend on analysis hydraulic regime, wind direction and wave in the study area. This paper presents the model application for simulation spill scenarios. It helps in selecting eco-sensitive regions for preparedness and planning suitable response strategies whenever spill incident occurred.
In this paper the numerical method for the shallow water equations is studied. The paper consists... more In this paper the numerical method for the shallow water equations is studied. The paper consists of 3 sections. In the section 1 the theoretical basis and software IMECI-L2DBREAK for simulation of the 2D dam-break or dyke-break flows is outlined. In the section 2 some results in verification of the IMECH_2DBREAK by the test cases proposed in the big European Hydraulics Laboratories are shown. In the last section some applications of IMECH_2DBREAK for the inundation problem in the Red river delta in the Northern of Vietnam are presented.
Journal of Construction Engineering and Management, 2003
Several representative environmental loads emitted from the life cycle of highways, which form on... more Several representative environmental loads emitted from the life cycle of highways, which form one of the major infrastructure sectors, were estimated. The life cycle of highways was divided into four stages-manufacturing of construction materials, construction, maintenance/repair, and the demolition/recycling stage. Energy consumption in each life cycle stage was quantified, and environmental load was estimated by applying the environmental emissions factor per each energy source. As a result, it is estimated that the most energy was consumed in the manufacturing stage of construction materials, with consumption of 1,525.8 tons of oil equivalent ͑TOE͒ per functional unit ͑1 km and four lanes of highway͒. Energy consumption in the maintenance and repair stage was also relatively high among the life cycle stages; the next highest consumption was for the construction and demolition stage. Through the whole life cycle of 20 years, 2,676.8 TOE of energy per functional unit was consumed, and this corresponds to SO 2 , NO x , and CO 2 emissions of 62.1 tons, 17.1 tons, and 2,438.5 T-C, respectively.
International Journal of Ecology & Development, 2016
Conserving groundwater resource requires the construction of a dam to increase the amount of wate... more Conserving groundwater resource requires the construction of a dam to increase the amount of water resources while also preventing seawater intrusion. In this paper, we simulate groundwater flow regime in a combination with a subsurface dam on an island designed to ensure a proper utilization of groundwater resources. The results of this study indicate that the construction of a subsurface dam has a possibility by means of which the availability of water resources can be increased and prevent seawater intrusion. The subsurface dam constructed in Phuket of Thailand would increase 2.5 m of groundwater heads and significantly increase 57.5% of groundwater yield without causing seawater intrusion.
Lowland technology international : the official journal of the International Association of Lowland Technology, Jun 1, 2006
This paper presents the development and application of a conjunctive water management model for l... more This paper presents the development and application of a conjunctive water management model for lowland catchments. The model incorporates a simulation model and a management model to simulate groundwater movement, ground consolidation and to search for the potential pumping amount of groundwater without violating physical and environmental constraints. The results reveal that groundwater levels in a coastal aquifer greatly vary in response to pumping. Consequently subsidence rapidly occurs throughout the area. The study also suggests that conjunctive water management can be used to improve water supply reliability, to reduce groundwater overdraft and land subsidence and to improve environmental conditions.
Physics And Chemistry Of The Earth, Parts A/b/c, Oct 1, 2019
The purpose of this study is to apply numerical modeling to assess the water quality in Cam and L... more The purpose of this study is to apply numerical modeling to assess the water quality in Cam and Lach Tray coastal estuaries. The wind re-analysis data from Weather Research and Forecasting (WRF) model were used to simulate wave and the hydrodynamic regimes with a definition of 14 km within the longitude range from 105 0 E to 120 0 E and latitude range from 5 0 to 22 0 in the study area. The calibration and validation results for the wind-wave, hydrodynamic regimes showed that the performance of 2D hydrodynamic model is extremely good with a Nash coefficient ranges from 0.89 to 0.92, an RMSE-observations standard deviation ratio (RSR) varies from 0.25 to 3.6 and a Percent bias (PBIAS) is from-4.2% to 0.2%. The calibrated 2D hydrodynamic model are combined with the Ecolab model to evaluate and simulate the spreading of water quality parameters (BOD, NH 4 + , and TSS). During the high tides, the tidal moves into the river, and therefore, the spread of water quality
A novel piston pin design is proposed for diesel engines having higher load capacity than current... more A novel piston pin design is proposed for diesel engines having higher load capacity than current pin designs. This shaped piston pin incorporates a stress-reducing profile with lubricant film thickness enhancing features on the surface. Three dimensional FEA models were built and are used to model the dynamic contact between the piston and connecting rod interfaces with a standard piston pin and the new piston pin design.
The dumping of dredge materials often raises concerns about the release of pollutants to the mari... more The dumping of dredge materials often raises concerns about the release of pollutants to the marine environment. Wind data from the Global Forecast System (GFS) model was used to simulate the wind-wave propagation from offshore in a two-dimensional (2D) model during September and October 2016. The calibration and validation of the 2D model showed a high conformity in both the phases and amplitude between the observed and simulated data. The 2D mud transport simulation results of three scenarios showed that the concentration of suspended material in the third scenario tested (scenario 3) was greater than 0.004 kg/m 3 in the low tide, spreading to a 9 km 2 area, and in the high tide, the concentration was 0.004 kg/m 3 in a 6 km 2 area. Finally, the results of 2D particle tracking (PT) showed changes in the seabed due to the concentration of dredged material, and its dump (approximately 180 days) increased from 0.08 m to 0.16 m in 2.85 ha. In scenario 3, the element block moved quite far-approximately 2.9 km-from the dredge position. Therefore, the simulation results were qualified, as the dredging position situated far from the sea is significantly affected by the direction and velocity of wave-wind in the dredging position.
The main objective of this paper is to forecast the integrated impacts of both climate change and... more The main objective of this paper is to forecast the integrated impacts of both climate change and land use changes on surface hydrology which is focused particularly on streamflow assessment under scenarios (A2, B1, and A1B) of climate change and land use change (2030, 2050, and 2080) in Nakdong basin by combination of both models as hydrology model (ArcSWAT) and land use change model (CA_Markov). The results indicated that the mean annual integrated impacts of climate change and land use change on streamflow in the future showed an increase tendency for all periods under scenarios A2, B1, and A1B. However, B1 scenario showed the highest of +3.97%, while A2 showed the lowest increase of +1.1%. However, the mean months of streamflow showed different changes that were forecasted large changes as an increase from +12 to +18% in months of Jan, Feb, Jul and Aug, while it showed a significant reduction from-9.0% to-19% in May and Oct for all periods under A2, B1, and A1B scenarios. Moreover, results were also to reveal that land use change and climate change both increased on the mean annual streamflow, but the impact of climate change was higher than that of land use change.
the molecular weight effects the diffusion of molecules in the interface of laminar flow form in ... more the molecular weight effects the diffusion of molecules in the interface of laminar flow form in a microfluidic channel. Two mixtures of PS with anisole and PEG were used to evaluate the molecular weight effect on the microfluidic separation. Also, the separation of a low molecular weight substance of anisole from the mixture with a high molecular weight substance of PS is proved experimentally. However, the separation of PEG from the mixture with PS remained difficulty. More information about diffusion in microfluidic channel and can be applied to polymer science and separation fields.
This paper presents methods to determine the value of water resource inventory indicators for Vie... more This paper presents methods to determine the value of water resource inventory indicators for Vietnam including total rainfall, total surface water amount, surface water quality, groundwater reserve and quality, exploitation and use of surface water and underground water, wastewater discharge into water sources, and economic values of water resources for the cases of full data, lack of data and no data. The application of water inventory for the Ba river basin shows that the average total annual rainfall in the basin is 1823 mm; the total annual average volume of surface water at Cung Son station is 7,973.63 million m 3 , the total amount of exploitation used for the main water users (for hydropower) is 6,085.49 million m 3. These obtained results are based on observed data and thus they have high reliability and can be used for water resource planning for this river basin. The methods determining inventory indicators presented in this paper can be used consistently for water resources inventory in Vietnam.
Physics and Chemistry of the Earth, Parts A/B/C, 2019
The purpose of this study is to apply numerical modeling to assess the water quality in Cam and L... more The purpose of this study is to apply numerical modeling to assess the water quality in Cam and Lach Tray coastal estuaries. The wind re-analysis data from Weather Research and Forecasting (WRF) model were used to simulate wave and the hydrodynamic regimes with a definition of 14 km within the longitude range from 105 0 E to 120 0 E and latitude range from 5 0 to 22 0 in the study area. The calibration and validation results for the wind-wave, hydrodynamic regimes showed that the performance of 2D hydrodynamic model is extremely good with a Nash coefficient ranges from 0.89 to 0.92, an RMSE-observations standard deviation ratio (RSR) varies from 0.25 to 3.6 and a Percent bias (PBIAS) is from-4.2% to 0.2%. The calibrated 2D hydrodynamic model are combined with the Ecolab model to evaluate and simulate the spreading of water quality parameters (BOD, NH 4 + , and TSS). During the high tides, the tidal moves into the river, and therefore, the spread of water quality
In 2011, an oil spill occurred off Lach Huyen port in the Northeast of Vietnam, due to vessels co... more In 2011, an oil spill occurred off Lach Huyen port in the Northeast of Vietnam, due to vessels collision. The results of collision caused pollution on wide area and surrounding areas. This paper was used MIKE 21 SA model to simulate oil spill transport with five scenarios. The results of simulation showed that spill trajectory and slick area depend on analysis hydraulic regime, wind direction and wave in the study area. This paper presents the model application for simulation spill scenarios. It helps in selecting eco-sensitive regions for preparedness and planning suitable response strategies whenever spill incident occurred.
In this paper the numerical method for the shallow water equations is studied. The paper consists... more In this paper the numerical method for the shallow water equations is studied. The paper consists of 3 sections. In the section 1 the theoretical basis and software IMECI-L2DBREAK for simulation of the 2D dam-break or dyke-break flows is outlined. In the section 2 some results in verification of the IMECH_2DBREAK by the test cases proposed in the big European Hydraulics Laboratories are shown. In the last section some applications of IMECH_2DBREAK for the inundation problem in the Red river delta in the Northern of Vietnam are presented.
Journal of Construction Engineering and Management, 2003
Several representative environmental loads emitted from the life cycle of highways, which form on... more Several representative environmental loads emitted from the life cycle of highways, which form one of the major infrastructure sectors, were estimated. The life cycle of highways was divided into four stages-manufacturing of construction materials, construction, maintenance/repair, and the demolition/recycling stage. Energy consumption in each life cycle stage was quantified, and environmental load was estimated by applying the environmental emissions factor per each energy source. As a result, it is estimated that the most energy was consumed in the manufacturing stage of construction materials, with consumption of 1,525.8 tons of oil equivalent ͑TOE͒ per functional unit ͑1 km and four lanes of highway͒. Energy consumption in the maintenance and repair stage was also relatively high among the life cycle stages; the next highest consumption was for the construction and demolition stage. Through the whole life cycle of 20 years, 2,676.8 TOE of energy per functional unit was consumed, and this corresponds to SO 2 , NO x , and CO 2 emissions of 62.1 tons, 17.1 tons, and 2,438.5 T-C, respectively.
International Journal of Ecology & Development, 2016
Conserving groundwater resource requires the construction of a dam to increase the amount of wate... more Conserving groundwater resource requires the construction of a dam to increase the amount of water resources while also preventing seawater intrusion. In this paper, we simulate groundwater flow regime in a combination with a subsurface dam on an island designed to ensure a proper utilization of groundwater resources. The results of this study indicate that the construction of a subsurface dam has a possibility by means of which the availability of water resources can be increased and prevent seawater intrusion. The subsurface dam constructed in Phuket of Thailand would increase 2.5 m of groundwater heads and significantly increase 57.5% of groundwater yield without causing seawater intrusion.
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