79 research outputs found
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
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
An Assessment of Cough Medicine Dispensing Practice to Children Under Two Years Old in Pharmacies in Ho Chi Minh City Using Simulated-Patient Method
Over-the-counter (OTC) cough and cold medications (CCMs) have been used to treat the symptoms of upper respiratory infection in children for decades. The safety of CCMs in children has been questioned. The data on knowledge of pharmacists in supplying cough medicines for children under two years have been limited. This study aimed to evaluate the pharmacists’ dispensing decisions to manage the cough in children under two years old. A descriptive cross-sectional was carried out in 300 pharmacies in 15 districts in Ho Chi Minh City, Vietnam. The pharmacists were interviewed by a simulated patient. The results showed that, information that pharmacists actively asked the client about the patient and disease symptoms was limited. Most pharmacists did not provide adequate instructions and counsel about using drugs for clients. Only 22/300 (7.33%) of pharmacists appropriately provided cough medicines for children under 2 years old. The main reason of inappropriateness was the deficiency of knowledge about updated contraindication of N-acetylcysteine (93.17%). Pharmacists in pharmacies located in districts 3, 11 and Binh Thanh had higher rate of rational provision than those in other districts. A good and full understanding of the patient symptom helped the pharmacists supply cough medicines more reasonably. The limited caution of pharmacists and the low proportion of pharmacists updating contraindication of N-acetylcysteine should be considered as a warning sign in pharmacy practice in Ho Chi Minh City, Vietnam
A new species of the paper wasp genus Ropalidia Guérin-Méneville, plebeja group (Hymenoptera, Vespidae, Polistinae), from Vietnam
A new species, Ropalidia daklak Bui, Mai & Nguyen, sp. nov., belonging to the plebeja-group of the genus Ropalidia Guérin-Méneville, 1831 is described and figured based on females and males from Vietnam. The nest structure of the new species is described, and an updated key is provided to all known species of the group
Climate change scenarios for the study regions and their impacts on rice production with respect to droughts and salinity identified
Experimental modal analysis and optimal design of cab’s isolation system for a single drum vibratory roller
The purpose of this paper is to solve problems about cab’s low-frequency shaking in the direction of forward motion when vibratory roller operates. To solve this problem, a modal test for a single-drum vibratory roller is carried out by the Belgium LMS dynamic testing which is used to identify the model parameters and find out the natural frequency of the vehicle. A Finite Element Analysis (FEA) simulation is carried out to find out the reasons causing the cab’s low-frequency shaking. The model simulation results are found to be in good agreement with the experimental results. Finally, the design parameters of cab’s isolation system are optimized to reach the maximum value of the first-order natural frequency in order to avoid resonance vibration for cab at low frequency and reduce cab’s low-frequency shaking
Synthesis, crystal structure and Hirshfeld surface analysis of 4-[3-(4-hy-droxy-phen-yl)-4,5-di-hydro-1H-pyrazol-5-yl]-2-meth-oxy-phenol monohydrate.
In the title pyrazoline derivative, C16H16N2O3·H2O, the pyrazoline ring has an envelope conformation with the substituted sp 2 C atom on the flap. The pyrazoline ring makes angles of 86.73 (12) and 13.44 (12)° with the tris-ubstituted and disubstituted benzene rings, respectively. In the crystal structure, the mol-ecules are connected into chains running in the b-axis direction by O-H⋯N hydrogen bonding. Parallel chains inter-act through N-H⋯O hydrogen bonds and π-π stacking of the tris-ubstituted phenyl rings. The major contribution to the surface contacts are H⋯H contacts (44.3%) as concluded from a Hirshfeld surface analysis
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
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
Study on active tectonic faults using soil radon gas method in Viet Nam
This paper presents the results of soil radon gas measurement in three areas, including Thac Ba and Song Tranh 2 hydropower plants, and the planned locations of the nuclear power plants Ninh Thuan 12 using solid-state nuclear track detectors (SSNTD) with the aim of clarifying the activity of tectonic faults in these areas. The activity of tectonic faults was assessed through radon activity index KRn (the ratio between anomaly and threshold), which was divided into 5 levels as follows ultra-high (KRn 10), high (10≥KRn 5), high (5≥KRn 3), medium (3≥KRn 2) and low (KRn≤2). Soil radon gas measurement results showed that in the radon gas concentrations in the Thac Ba hydropower plant area ranged from 72 Bq/m3 to 273.133 Bq/m3 and maximum radon activity index KRn reached 9.75 (high level). High KRn indexes show Chay River fault active in recent time and the sub-meridian distribution of Rn anomalies suggested a right-slip motion of the fault. Rn concentrations in the Ninh Thuan 12 areas ranged from 6 Bq/m3 to 52.627 Bq/m3, however, the KRn indexes were mostly low (KRn≤3) and the highest value was only 3.42, suggesting that expression of activity of the tectonic faults in this region is not clear, even no expression of fault activity. In the Song Tranh 2 hydropower plant and adjacent areas, radon concentrations ranged from 29 Bq/m3 to 77.729 Bq/m3 and maximum KRn index was 20.16 (ultra-high level). The faults having clearer activity expression are Hung Nhuong - Ta Vy, Song Tra Bong and some high order faults, especially the northwest - southeast segments of these faults or their intersections with the northwest - southeast faults. In addition, the high values KRn in the mentioned intersections can be evidenced for the activeness of northwest - southeast faults at the present time. The studies on active faults using soil radon gas method were performed in areas with very different geological and structural features, but the results are well consistent with the results of previous investigations obtained by other methods. It confirmed the effectiveness and capability of soil radon gas geochemistry applying to study active tectonic faults.ReferencesAl-Hilal M., Al-Ali A., 2010. The role of soil gas radon survey in exploring unknown subsurface faults at Afamia B dam, Syria. Radiat. Meas, 45, 219-224.Amponsah, P., Banoeng-Yakubo, B., Andam, A., Asiedu, D., 2008. Soil radon concentration along fault systems in parts of south eastern Ghana. J. Afr. Earth Sci. 51, 39-48.Asumadu-Sakyi A.B., Fletcher J.J., Oppon O.C., Qua- shie F.K., Wordson D.A., Adjei C.A., Amartey E.O., Darko E.O. and Amponsah P., 2011. Preliminary Studies on Geological Fault Location Using Solid State Nuclear Track Detection. Research Journal of Environmental and Earth Sciences, 3(1), 24-31.Baubron, J.-C., Rigo, A., Toutain, J.-P., 2002. Soil gas profiles as a tool to characterize active tectonic are- as: the Jaut Pass example (Pyrenees, France). Earth Planet. Sci. Lett, 196, 69-81.Burton, M., Neri, M., Condarelli, D., 2004. High spatial resolution radon measurements reveal hidden active faults on Mt. Etna. Geophys. Res. Lett, 31, L07618.Ciotoli, G., Etiope, G., Guerra, M. Lombardi, S., 1999. The detection of concealed faults in the Ofan- to basin using the correlation between soil gas fracture surveys. Tectonophysics, 299(3-4), 321-332.Ciotoli, G., Lombardi, S. Annunziatellis, A., 2007. Geostatistical analysis of soil gas data in a high seismic intermontane basin: Fucino Plain, central Italy. J. Geophys. Res., 112, B05407, doi:10.1029/2005JB004044.Font, L., Baixeras, C., Moreno, V., Bach, J., 2008. Soil radon levels across the Amer fault. Radiat. Meas, 43, 319-323.Geological and Mineral Resources Map of Viet Nam on 1:200,000, 2005. Published by Department of Geology and Minerals of Viet Nam, Ha Noi, Lists: Yen Bai (F-48-XXI), Tuyen Quang (F-48-XXII), Quang Ngai (D-49-VIIVIII), Hoi An (D-49-I), Da Lat - Cam Ranh (C-49-III).Ghosh D., Deb A. and Sengupta R., 2009. Anomalous radon emission as precursor of earthquake. J. Appl. Geophys., 69, 67-81.González-Díez, A., Soto, J., Gómez-Arozamena, J., Bonachea, J., Martínez-Díaz, J.J., Cuesta, J.A.,Olague, I., Remondo, J., Fernández Maroto, G., Díaz de Terán, J.R., 2009. Identification of latent faults using a radon test. Geomorphology, 110,11‐19.Haerudin N, Wahyudi, Munadi S., Suryanto W., 2013. A Soil Gas Radon Survey to Determine Fault at Southern Part of Rajabasa Geothermal Field, Lampung Indonesia. International Journal of Engineering Technology IJET-IJENS, 13(1), 75-81.Hauksson E., 1981. Radon content of groundwater as an earthquake precursor: evaluation of worldwide data and physical basis. J. Geophys. Res., 86, 9397-9410.Ioannides, K., Papachristodoulou, C., Stamoulis, K., Ka- ramanis, D., Pavlides, S., Chatzipetros, A., Karakala, E., 2003. Soil gas radon: a tool for exploring active fault zones. Appl. Radiat. Isot, 59, 205-213.Israel H. and Bjornsson S., 1967. Radon (Rn-222) and thoron (Rn-220) in soil air over faults. Z. Geophys, 33, 48-64.Kemski, J., Siehl, A., Stegemann, R., Valdivia- Manchego, M., 2001. Mapping the geogenic radon potential in Germany. Sci. Total Environ, 272, 217-230.King C.Y., 1978. Radon emanation on San Andreas fault. Nature, 271, 516-519.King, C.Y., King, B.S., Evans, W.C., 1996. Spatial radon anomalies on active faults in California. Appl. Geochem, 11, 497-510.Laskar I., Phukon P., Goswami A.K., Chetry G. and Roy U.C., 2011. A possible link between radon anomaly and earthquake. Geochemical Journal, 45, 439-446.Lombardi, S., Voltattorni, N., 2010. Rn, He and CO2 soil gas geochemistry for the study of active and inactive faults. Appl. Geochem, 25, 1206-1220.Moussa M.M., Arabi A-G. M. E., 2003. Soil radon survey for tracing active fault: a case study along Qena- Safaga road, East Desert, Egypt. Radiat. Meas, 37,211-216.Papastefanou C., 2010. Variation of radon flux along active fault zones in association with earthquake occurrence. Radiat. Meas, 45, 943-951.Nguyen Dang Tuc, 2000. Kinematic characteristics of the Red River - Chay River fault zone in Cenozoic. Journal of Sciences of the Earth, 22, 174-180 (in Vietnamese).Nguyen Van Pho, Nguyen Trong Yem, 1996. Gas geochemical approach in study of the activity of Red River fault system. Journal of Geology, Ha Noi, series A, 236, 9-10.Nguyen Van Pho, Hoang Tuyet Nga, 1996. Some results of the micro geodynamic maping in Thac Ba area by using of nuclear track detector method. In Geology - Resources, Sci. and Tech. Publishing house, Ha Noi, , 187-191.Nguyen Van Pho, Hoang Thi Tuyet Nga, Doan Thi Thu Tra, 1999. Study on the stability of Thac Ba hy- drpopower dam by using nuclear track detector method. Journal of Geology, Ha Noi, Series B, 13-14, 270-271.Nguyen Van Pho, Hoang Thi Tuyet Nga, Nguyen Trung Minh, Doan Thi Thu Tra, Vu Manh Long, Le Thanh Chung, Nguyen Dinh Xuyen, Pham An Cuong, 2004. Results of radon continuous measurements in soil gas at the North-Western area. Journal of Sciences of the Earth, 26, 653-656 ( in Vietnamese).Nguyen Trong Yem, 1996. Regimes of tectonic stress field during Cenozoi in Vietnam. Journal of Geology, Ha Noi, series A, 236, 1-6.Reimann C., Filzmoser P., Garrett R.G., 2005. Background and threshold: critical comparison of methods of determination. Science of the Total Environment, 346, 1-3, 1-16.Richon P., Klinger Y., Tapponnier P., Li C.X., Van Der Woerd J., Perrier F., 2010. Measuring radon flux across active faults: Relevance of excavating and possibility of satellite. Radiation Measurements, 45, 211-218.Riggio A., and Santulin M., 2015. Earthquake forecasting: a review of radon as seismic precursor. Bollettino di Geofisica Teorica ed Applicata, 56(2), 95-114.Seminsky K.Zh., Demberel S., 2013. The first estimations of soil-radon activity near faults in Central Mongolia. Radiation Measurements, 49, 19-34.Swakón, J., Kozak, K., Paszkowski, M., Gradzinski, R., Loskiewicz, J., Mazur, J., Janik, M., Bogacz, J.,Horwacik, T., Olko, P., 2004. Radon concentration in soil gas around local disjunctive tectonic zones in the Krakow area. J. Environ. Radioact, 78, 137-149.Tanner, A.B., 1980. Radon migration in the ground: A supplementary review, in Gesell, T.F., and Lowder, W.M., eds., Natural Radiation Environment III: U.S. Dept. Energy Rept. CONF-780422, 1, 5-56.Toutain J.P., Baubron J.C., 1999. Gas geochemistry and seismotectonics: a review. Tectonophysics 304, 1-27.Tran Trong Hue, 1996. First results of research present geodynamics by soil gas radon method. In Geology - Resource, Ha Noi, 1, 179-185.Tran Trong Hue, 1999. Characteristics of radon radioactive gas in Song Ma fault zone. Journal of Sciences of the Earth, 123-128.Tung S., Leung J. K. C., Jiao J. J., Wiegand J., Wartenberg W., 2013. Assessment of soil radon potential in Hong Kong, China, using a 10-point evaluation system. Environmental Earth Sciences, 68(3), 679-689.Tran Van Duong, Tran Trong Hue, 1996. Some results of the investigation active faults in the South Central Viet Nam by radon method. Journal of Science of the Earth, 18, 276-288.Tran Van Tri, Vu Khuc et al., 2009. Geology and earth resources of Viet Nam. Publishing House for Science and Technology, Ha Noi, 645.Utkin V.I., Yurkov A.K., 2010. Radon as a tracer of tectonic movements. Russian Geology and Geophysics, 51, 220-227.Wakita H., Nakamura Y., Notsu K., Noguchi M. and Asada T., 1980. Radon anomaly: a possible precursor of the 1978 Izu-Oshimakinkai earthquake. Sci., 207, 882-883.Walia V., Mahajan S., Kumar A., Singh S., Singh Bajwa B., Dhar S., Yang T.F., 2008. Fault delineation study using soil gas method in the Dharamsala area, NW Himalayas, India . Radiat. Meas, 43, 337-342.Wang X., Li Y., Du J., Zhou X., 2014. Correlations be- tween radon in soil gas and the activity of seismo- genic faults in the Tangshan area, North China. Ra- diation Measurements, 60, 8-14
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