Study on the influence of bus suspension parameters on ride comfort

This study proposes a three-dimensional vibration model of bus with 10 DOF (degree of freedom) based on Dragan Sekulić model to analyze the suspension parameters directly influenced ride comfort. The suspension parameters which include the stiffness and damping parameters are analyzed based on the weighted r.m.s. (root-mean-square) acceleration responses of the space of a driver, passenger in the middle part of the bus and passenger in the rear overhang according to ISO 2631-1:1997. The results show that both stiffness and damping parameters of vehicle suspension have important influences on ride comfort. Especially, the stiffness and damping values of vehicle suspension are within the value ranges (0.5k0 ≤ k ≤ 0.75 k0) and (0.5c0 ≤ c ≤ 0.75c0) to improve the ride comfort of driver and passengers

STEM Teaching Skills of Primary School Teachers: The Current Situation in Ho Chi Minh City, Vietnam

STEM education is an educational solution that prepares pupils for the future by connecting scientific knowledge with practical applications. This modern method of education is being widely applied in developing countries in order to maintain their scientific and technical standing and strengthen their competition in the global economy. In Vietnam, special attention has been paid to STEM education, as is demonstrated by the policies and guidelines of the Party and State. However, are the skills of the universal teaching staff, particularly in primary schools, sufficient to satisfy the demand for STEM education? A survey was carried out to analyze the current situation with regards the STEM teaching skills of primary school teachers in the district of Thu Duc, Ho Chi Minh City. By analyzing the survey results using SPSS, this article presents the current status of the STEM teaching skills of the primary school teachers in Thu Duc, Ho Chi Minh City, and suggests some solutions to improve and develop teachers’ STEM education skills, suitable for the teaching conditions in Ho Chi Minh City, Vietnam

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)

SMALL POWER ENGINE FUELED WITH BIOGAS

Joint Research on Environmental Science and Technology for the Eart

The influence of scalar unparticle on the production of multiple photons in the Randall- Sundrum model

The influence of scalar unparticle on the production of multiple photons in the Randall- Sundrum model at muon colliders with the center of mass energy $\sqrt{s} = 3 - 10$ TeV is evaluated in detail. The results indicate that the total cross-sections depend strongly on the polarization of the muon and antimuon beams, the collision energy $\sqrt{s}$, the scaling dimension $d_{U}$ of the unparticle operator $\mathcal{O}_{U}$ and the energy scale $\Lambda_{U}$. Numerical evaluation shows that the cross - sections for the production of four - photons at the final state are much larger than the associated production of two - photons with the unparticle under the same conditions.Comment: 13 figures, 1 table. arXiv admin note: text overlap with arXiv:1807.0045

Influence of damping coefficient into engine rubber mounting system on vehicle ride comfort

This study presents a method to improve vehicle ride comfort using additional damping coefficient values for an internal combustion engine (ICE) rubber mounting system. To analyze the effect of the adding damping coefficient values into the rubber mounting system on vehicle ride comfort, a full-vehicle vibration model with 10 degrees of freedom is established under the combination of road surface roughness and ICE excitations. The damping coefficient values are added into ICE rubber mounting system which are respectively analyzed and evaluated according to the international standard ISO 2631-1 (1997). The study results do not only evaluate the influence of the adding damping coefficients on vehicle ride comfort but also suggest the optimal design solution for ICE mounting system to improve vehicle ride comfort