MODELING OF FLOW AND PARTICLE DYNAMICS HUMAN RESPIRATORY SYSTEM USING FLUID DYNAMICS

The aim of this research is to study numerically the flow characteristics and particle transport within a human respiratory system, including the human nasal cavity and the bifurcation. Various flow rates and particle sizes are main parameters varied in order to analyze the effects on particle movements and deposition on the human respiratory system. There are three main systems considered in this research: flow around a blockage in a channel, flow in the Final particle deposition with Stokes number, St = 0.12 for inlet flow rates of: (a) 30 L/min; (b) 60 L/min in human nasal cavity, and flow in the double bifurcation. Computational Fluid Dynamics (CFD) is used to solve gas-particle flow equations using a commercial software, FLUENT. Flow around a blockage in a channel was performed to gain confidence in the CFD model that has recirculation zone behind the block. The unsteady vortices flow around this blockage is investigated for Reynolds numbers, Re = 150, 300, 600, 900, and 1200 and Stokes numbers, St = 0.01, 0.1, 0.5, 1.0 and 2.0 by solving momentum and particle model equations. A detailed airflow structures such as vortices, flow distribution are obtained. It was found that the particle distribution depends on vortical structures and Stokes number. A model of real human nasal cavity is reconstructed from computerized tomography (CT) scans. The flow structure is validated with experimental data for flowrates of 7.5 L/min (Re = 1500) and 15 L/min (Re = 3000). The total particle deposition in nasal cavity is also validated with experimental data using inertial parameter. Then the model is further investigated the effect of turbulence on particle deposition with flowrates of 20, 30 and 40 L/min. Deposition was found to increase with Stoke number for the same Reynolds number. vii Three-dimensional double bifurcations with coplanar configurations are employed to investigate the flow. Results of laminar flow (Re = 500, Re = 1036, and Re = 2000) are used to compare with experimental and numerical solution for validation. The model is further used to investigate the turbulent flow and particle deposition for heavy breathing with flowrates of 30 L/min (Re = 7300) and 60 L/min (Re = 14600). It was found that the deposition efficiency is dependent on Reynolds number and Stokes numbers. This research outcome will guide to improve the injection particle drugs to human lungs and to develop nasal mask to protect the lungs from hazardous particles

SYNTHESIS OF BIODIESEL FROM VARIOUS SOURCES OF PLANT OILS

"The use of vegetable oils for engine fuels may seem insignificant today. But such oils may become in the course of time as important as the petroleum and coal tar products of the present time" (RudolfDiesel, 1912). Nowadays, environment has been affected seriously by the industrialization. Many effects such as green house effect, undegradable materials are slowlycausing harmful to environmentand human lives. Every country suggestof using biodiesel due to its degradability, safety with environment and also many advanced properties compared with mineral-based fluids. The main resources for synthesis ofbio-based diesel are various and we decided to choose palm kernel oil, jatropha curcus oil and canola curcas oil as the base oils, and also sodium hydroxide and potassium hydroxide as main catalysts. The aim of this research is to study the advance of the bio-based diesel and also the kinetics of reactions and characteristics ofdiesel produced from different bio-based oil feed stocks

Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy

The Fermi transition (\Delta L=\Delta S=0 and \Delta T=1) between the nuclear isobaric analog states (IAS), induced by the charge-exchange (p,n) or (3He,t) reaction, can be considered as "elastic" scattering of proton or 3He by the isovector term of the optical potential (OP) that flips the projectile isospin. The accurately measured (p,n) or (3He,t) scattering cross-section to the IAS can be used, therefore, to probe the isospin dependence of the proton or 3He optical potential. Within the folding model, the isovector part of the OP is determined exclusively by the neutron-proton difference in the nuclear densities and the isospin dependence of the effective nucleon-nucleon (NN) interaction. Because the isovector coupling explicitly links the isovector part of the proton or 3He optical potential to the cross section of the charge-exchange (p,n) or (3He,t) scattering to the IAS, the isospin dependence of the effective (in-medium) NN interaction can be well tested in the folding model analysis of these charge-exchange reactions. On the other hand, the same isospin- and density dependent NN interaction can also be used in a Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear matter energy and its asymmetry part (the nuclear symmetry energy). As a result, the fine-tuning of the isospin dependence of the effective NN interaction against the measured (p,n) or (3He,t) cross sections should allow us to make some realistic prediction of the nuclear symmetry energy and its density dependence.Comment: Accepted for publication in European Physical Journal A - "Hadrons and Nuclei

MODELING OF FLOW AND PARTICLE DYNAMICS HUMAN RESPIRATORY SYSTEM USING FLUID DYNAMICS

The aim of this research is to study numerically the flow characteristics and particle transport within a human respiratory system, including the human nasal cavity and the bifurcation. Various flow rates and particle sizes are main parameters varied in order to analyze the effects on particle movements and deposition on the human respiratory system. There are three main systems considered in this research: flow around a blockage in a channel, flow in the Final particle deposition with Stokes number, St = 0.12 for inlet flow rates of: (a) 30 L/min; (b) 60 L/min in human nasal cavity, and flow in the double bifurcation. Computational Fluid Dynamics (CFD) is used to solve gas-particle flow equations using a commercial software, FLUENT. Flow around a blockage in a channel was performed to gain confidence in the CFD model that has recirculation zone behind the block. The unsteady vortices flow around this blockage is investigated for Reynolds numbers, Re = 150, 300, 600, 900, and 1200 and Stokes numbers, St = 0.01, 0.1, 0.5, 1.0 and 2.0 by solving momentum and particle model equations. A detailed airflow structures such as vortices, flow distribution are obtained. It was found that the particle distribution depends on vortical structures and Stokes number. A model of real human nasal cavity is reconstructed from computerized tomography (CT) scans. The flow structure is validated with experimental data for flowrates of 7.5 L/min (Re = 1500) and 15 L/min (Re = 3000). The total particle deposition in nasal cavity is also validated with experimental data using inertial parameter. Then the model is further investigated the effect of turbulence on particle deposition with flowrates of 20, 30 and 40 L/min. Deposition was found to increase with Stoke number for the same Reynolds number. vii Three-dimensional double bifurcations with coplanar configurations are employed to investigate the flow. Results of laminar flow (Re = 500, Re = 1036, and Re = 2000) are used to compare with experimental and numerical solution for validation. The model is further used to investigate the turbulent flow and particle deposition for heavy breathing with flowrates of 30 L/min (Re = 7300) and 60 L/min (Re = 14600). It was found that the deposition efficiency is dependent on Reynolds number and Stokes numbers. This research outcome will guide to improve the injection particle drugs to human lungs and to develop nasal mask to protect the lungs from hazardous particles

The Multiple Effects of Child Health Insurance in Vietnam

This paper estimates multiple effects of tremendous expansion in health insurance coverage for children on medical services utilizations for both children and parents by focusing on Free Care for Children Under Six, a child health insurance program that provides free access to health care practices for children under 6 in Vietnam. Using a regression discontinuity design, the paper finds that child health insurance has considerable positive effects on children’s health care uses whereas it reduces parental health care utilization for some outcomes. In particular, child health health insurance increases the probabilities of public inpatient visit and private outpatient visit by 22.3% and 33% respectively while it rises the frequencies of public inpatient visits and private outpatient visits by 0.32 times and 2.24 times respectively. In contrast, child health insurance reduces a mother’s probabilities of public inpatient visit and public outpatient visit by 32.6% and 27% respectively, number of public inpatient visits by 0.41 times. Also, paternal impacts of child health insurance consists of a 23.2% reduction in the probability of private outpatient visit and a 1.01 time decrease in the frequency of private outpatient visits. The paper significantly provides a more insightful understanding of various impacts of a health policy on health care utilization from developing countries

Intergenerational mobility of earnings and income among sons and daughters in Vietnam

This paper empirically examines intergenerational economic mobility in Vietnam. The two-sample two-stage least squares estimation is employed to achieve the research objective using two primary samples of father-son pairs and father-daughter pairs from Vietnam Household Living Standards Survey of 2012, and one secondary sample from Vietnam Living Standards Survey of 1997-1998. The baseline intergenerational elasticity estimates show that Vietnam occupies the intermediate degrees of intergenerational mobility of earnings and income for both sons and daughters. In particular, a rise of 10% in fathers’ individual earnings is on average associated with an increase of 3.61% and 3.94% for sons’ individual earnings and individual income, respectively. The corresponding figures for daughters’ individual earnings and individual income are 2.84% and 3.33%, respectively. This paper also provides evidence on the average degree of inequality of opportunity in Vietnam during its transition from a central planning economy to a market-oriented system