A5088002777- Rock Mechanics and Modeling
- Geomechanics and Mining Engineering
- Geotechnical and Geomechanical Engineering
- Geological and Geochemical Analysis
- Geoscience and Mining Technology
- Air Quality and Health Impacts
- Atmospheric chemistry and aerosols
- Geochemistry and Geologic Mapping
- earthquake and tectonic studies
- Landslides and related hazards
- High-pressure geophysics and materials
- Geological and Geophysical Studies
- Mining Techniques and Economics
- Air Quality Monitoring and Forecasting
- Coal Properties and Utilization
- Tunneling and Rock Mechanics
- Advanced Battery Technologies Research
- Mining and Gasification Technologies
- Electric and Hybrid Vehicle Technologies
- Grouting, Rheology, and Soil Mechanics
- Geotechnical Engineering and Underground Structures
- Safety and Risk Management
- Mercury impact and mitigation studies
- Geotechnical and construction materials studies
- Fluoride Effects and Removal
Hanoi University of Mining and Geology
1995-2024
The University of Queensland
2002-2024
UNSW Sydney
2016-2019
Ho Chi Minh City University of Science
2015
Vietnam National University Ho Chi Minh City
2015
Lawrence Berkeley National Laboratory
2009-2011
University of California, Berkeley
2009-2011
Aerodyne Research
2010
Massachusetts Institute of Technology
2010
The competition between the addition of polar, oxygen-containing functional groups (functionalization) and cleavage C–C bonds (fragmentation) has a governing influence on change in volatility organic species upon atmospheric oxidation, hence loading tropospheric aerosol. However relative importance these two channels is generally poorly constrained for oxidized organics. Here we determine fragmentation–functionalization branching ratios organics spanning range oxidation levels, using...
The heterogeneous oxidation of pure erythritol (C4H10O4) and levoglucosan (C6H10O5) particles was studied in order to evaluate the effects atmospheric aging on mass chemical composition organic aerosol. In contrast what is generally observed for reduced organics, substantial volatilization both systems. However, ratio decrease particle concentration parent species about three times higher than levoglucosan, indicating that details structure (such as carbon number, cyclic moieties,...
Particle Swarm Optimization (PSO) is an effective tool for solving nonlinear, non-convex optimization problems, offering a quick and efficient way to identify rational asset allocations. In PSO, each particle represents specific allocation moves within the search space optimize defined criteria. Particles update their positions based on personal experience (individual best) collective of swarm (global best), gradually converging toward optimal solution. Research applying PSO demonstrates...
Here we report a new method for measuring the heterogeneous chemistry of sub-micron organic aerosol particles using continuous flow stirred tank reactor. This approach is designed to quantify real time kinetics, relative rate method, under conditions low oxidant concentration and long reaction times that more closely mimic atmosphere than used in typical tube A general analytical expression, which couples with dynamics chamber developed applied oxidation squalane by hydroxyl radicals (OH)...
The Hai Van granitoid complex constitutes an important part of the Indosinian batholith northern Kontum massif in central Vietnam. is a key region for understanding palaeo-Tethyan accretionary history and crustal evolution Indochina terrane. In this study, zircon U–Pb ages geochemical data on are reported to shed more light these geological processes. Zircon isotopic analyses six representative samples by LA-ICP-MS technique show that granitoids from crystallized between 242 224 Ma,...
The reaction of Cl atoms, in the presence Cl2 and O2, with sub-micron squalane particles is used as a model system to explore how surface hydrogen abstraction reactions initiate chain that rapidly transform chemical composition an organic particle. heterogeneous measured photochemical flow tube reactor which chlorine atoms are produced by photolysis at 365 nm. By monitoring reaction, using vacuum ultraviolet photoionization aerosol mass spectrometer, effective reactive uptake coefficient...
It is important to maintain confidence in the risk and benefit balance of major caries-preventive programs using fluoride. The ongoing debate about potential effects early-life exposures fluoride on cognitive neurodevelopment requires high-quality scientific evidence. This study aimed investigate exposure assessed with Wechsler Adult Intelligence Scale 4th edition (WAIS-IV) an Australian population-based sample. sample was selected from National Child Oral Health Study (NCOHS) 2012-2014....
Neoproterozoic rocks in the Phan Si Pan Zone, NW Vietnam are considered to be remnant of ancient continental crust. They recorded evolution Gondwana supercontinent. A combined study U-Pb geochronology and Sr-Nd-Hf isotopic geochemistry has been carried out for granites Zone. Zircon LA-ICP-MS data yield crystallization ages ranging from 758.0 ± 5.0 762.0 8.1 Ma. The have variable (87Sr/86Sr)i ratios 0.7029 0.708 a wide range εNd(t) values (−2.02 0.04) zircon εHf(t) (−5.1 0.0). All these...
The first caving of top coal and the weighting roof strata in Longwall Top Coal Caving (LTCC) mining were analyzed a parametric study by using discontinuum modeling technique with plastic rock material. analysis demonstrated that an increase value cover depth decreases stability main strata, while impact horizontal stress on is not consistent under different magnitudes. confirmed immediate strength, elastic modulus, bedding spacing improves before its caving, whereas thickness, depth,...
Southeast Asia plays a key role in the evolution of eastern Tethys, which is characterized by accretion and amalgamation numerous terranes since early Paleozoic. In present study, an Paleozoic granitoid sequence from Kontum massif central Indochina block was investigated to reveal accretionary orogenesis Tethys. Early granitoids include diorites granites. Ordovician (485–473 Ma) Ben Giang show high Mg#, Cr Ni contents, negative Nb-Ta positive Pb anomalies as well zircon ɛHf(t) values (+6.2...
Discrete fractures may exist in thick coal seam and significantly impact the top stability Longwall Top Coal Caving method (LTCC) both ahead of shield support (top fall) behind caving). The such conditions is not well understood literature has been studied from either fall or caving behaviour. In this paper, a discontinuum-based numerical program used to study longwall when discrete vary characteristics (i.e., orientation, density, stiffness, strength, intersecting fractures). demonstrates...
Reliable estimation of coal and rock mechanical properties at field scale is a prerequisite for numerical modelling behaviours associated with longwall extraction. This paper describes systematic approach from data collection, laboratory testing to mass derivation simulation extraction, taking two panels Quang Ninh coalfield in Vietnam example. The are verified through comparison published the field, indicating close agreements. A simple model further developed demonstrate proper use...
When extracting coal seams in Vietnam underground mines, pillars are often left unmined for the protection of retained roadways longwall mining method. During operations, placed where high-stress concentrations occur abutment pressure zone adjacent panels, especially when under hard-to-cave main roof conditions. The instability loading may cause roadway to collapse, threatening safe operation a mine. This paper presents detailed numerical investigation effect pillar width on stability...
Longwall is the widely used mining method in word and Vietnam due to high production level of safety. To maintain as scheduled, stability a longwall face great importance, especially at areas adjacent gateroads where ground pressure strongly concentrated. This paper presents study on faces under medium hard-to-cave roofs. By using theoretical field measurement methods, authors conclude that such geological conditions, increases decreases cyclically. At site, fluctuates range 20÷26 MPa,...