11,699 research outputs found

    Study on the influence of bus suspension parameters on ride comfort

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    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

    Electroweak phase transition in the economical 3-3-1 model

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    We consider the EWPT in the economical 3-3-1 (E331) model. Our analysis shows that the EWPT in the model is a sequence of two first-order phase transitions, SU(3)→SU(2)SU(3) \rightarrow SU(2) at the TeV scale and SU(2)→U(1)SU(2) \rightarrow U(1) at the 100100 GeV scale. The EWPT SU(3)→SU(2)SU(3) \rightarrow SU(2) is triggered by the new bosons and the exotic quarks; its strength is about 1−131 - 13 if the mass ranges of these new particles are 102 GeV−103 GeV10^2 \,\mathrm{GeV} - 10^3 \,\mathrm{GeV}. The EWPT SU(2)→U(1)SU(2) \rightarrow U(1) is strengthened by only the new bosons; its strength is about 1−1.151 - 1.15 if the mass parts of H10H^0_1, H2±H^\pm_2 and Y±Y^\pm are in the ranges 10 GeV−102 GeV10 \,\mathrm{GeV} - 10^2 \,\mathrm{GeV}. The contributions of H10H^0_1 and H2±H^{\pm}_2 to the strengths of both EWPTs may make them sufficiently strong to provide large deviations from thermal equilibrium and B violation necessary for baryogenesis.Comment: 17 pages, 9 figure

    Copyright in Universities: An Exploratory Study from Vietnam

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    International law and the laws of most nations today acknowledge and safeguard the intellectual property rights of both organizations and individuals. This recognition serves to stimulate innovative and creative endeavors, facilitate the dissemination of scientific, technological, cultural, and artistic advancements, foster economic and societal development, and enhance the overall quality of life. Intellectual property assumes a critical role as a driving force behind innovation and creativity, fostering the growth of a nation's intellectual assets in terms of both quantity and value. This, in turn, contributes to bolstering creative capabilities and fostering a healthy competitive environment. Nevertheless, intellectual property rights violations are not uncommon, particularly in the context of higher education institutions in Vietnam. In this article, the authors employ qualitative research methods, following the "three-step test" outlined in the Berne Convention of 1971 for the protection of literary and artistic works, in conjunction with the stipulations of Vietnamese Intellectual Property Law. The results of this examination aid in the identification and location of infringements on the author's rights, such as inappropriate citation and plagiarism within university settings. Subsequently, the authors propose various solutions, which include legal adjustments, strategies for managing intellectual property, the establishment of cross-sectoral and inter-university networks, and the regulation of the responsibilities of scientific councils. These measures are intended to mitigate instances of intellectual property rights violations within Vietnamese universities in the present day. Keywords: Copyright, three-step test, intellectual property rights, infringement, universities… DOI: 10.7176/JLPG/137-02 Publication date:October 31st 202

    On a nonlinear heat equation associated with Dirichlet -- Robin conditions

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    This paper is devoted to the study of a nonlinear heat equation associated with Dirichlet-Robin conditions. At first, we use the Faedo -- Galerkin and the compactness method to prove existence and uniqueness results. Next, we consider the properties of solutions. We obtain that if the initial condition is bounded then so is the solution and we also get asymptotic behavior of solutions as. Finally, we give numerical resultsComment: 20 page

    Sizing and parametric optimization of a waste heat to power plant based on transcritical organic Rankine cycle

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    peer reviewedIn recent years, the transcritical (also called supercritical) organic Rankine cycle (Trans-ORC) has more and more aroused the attention for power generation from low-temperature heat source thanks to the better thermal matching between the heating and the cooling fluids of the high pressure heat transfer process. The absence of isothermal evaporation in transcritical ORC enables the heat source to be cooled down to a lower temperature despite an identical pinch point as in a comparable subcritical cycle. This leads to a greater utilization of the heat source. In other words, the transcritical cycle could produce more power with higher exergy efficiency compared to the subcritical one. This paper aims at sizing a transcritical ORC to recover energy from a cooling circuit of turbine exhaust gas and optimizing the operating conditions of the cycle from a thermoeconomic point of view. Indeed, several potential organic fluids, which satisfy the screening criteria (e.g. safety, environment, thermophysical properties and availability), will be used as working fluid to evaluate the performance and the specific investment capital (SIC) of the plant. The operating conditions (i.e. turbine inlet temperature and pressure, condensing temperature and heat sink outlet temperature) of the plant will also be optimized to find out the most suitable working fluid for the studied cycle

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

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    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

    SEROTYPES, TOXINS AND ANTIBIOTIC RESISTANCE OF Escherichia coli (E.COLI) STRAINS ISOLATED FROM DIARRHEIC RABBITS IN PHU VANG, THUA THIEN HUE

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    This study was conducted to determine the prevalence of E. coli in rabbits, their biochemical and serological characteristics, common virulence genes, and antibiotic resistance. The diarrhea rabbit feces were collected from households and rabbit farms in Phu Vang - Thua Thien Hue with a total of 250 samples for testing. The results showed that rabbits age from 31 to 45 days old had the highest incidence of diarrhea disease caused by E.coli (92.0%) and the lowest infection rate was observed in rabbits over 60 days old with an infection rate of 30%. Further, the isolated E.coli strains tested biochemical characteristics showed 100% motile, positive for indole and methyl red, fermenting glucose and lactose. Simultaneously these strains were detected belong to 7 serotypes O103, O157, O158, O169, O44, O125, O153 and susceptible to cefuroxime (95.45%), akamicin (86.37%), streptomycin (81.82%), amoxicillin (81.82%), tetracycline (68.18%), colistin (68.18%), ampicillin (63.63%), gentamycin (59.10%) and levofloxacin (50.0%), whilst resistant to doxycycline (100%), sulfamethoxazole-bactrim (95.46%), and neomycin (86.37%). By using PCR assay for detection of virulence genes of the isolated E. coli strains, there were 7 strains carried virulence genes, of which 4/7 E. coli strains carried eaeA and tsh genes (57.14%), 2/7 strains carried stx2 gene (28.57%); 1/7 E. coli strains carried stx1 gene (14.28%) and the F4, F5 and F6 genes were not found in all serotypes in this study

    Editorial: Interrogating the design of smart, sustainable, and socially just urban spaces: A look at institutions, places, and values

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    The article is the Editorial on the Research Topic Interrogating the design of smart, sustainable, and socially just urban spaces: A look at institutions, places, and values, which explore the dynamics between the socio-technological processes – value-based design being foremost among them – through which urban space emerges and takes on meaning. Furthermore, they engage with the question of how institutional design principles shape citizen participation in these processes

    Potential Usage of Rice Husk Ash-Cement Based Soil in Subbase and Base Courses in Road Construction

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    This paper presents an experimental study of rice husk ash-cement-based soil for layers in roadway construction. Rice husk ash (RHA) used in this study is a by-product of rice milling. In this work, twelve proportion mixes were used in this work with varying quantities of RHA (0-30%) and Portland cement blended amounts of 4, 6, 8%. The specimens were prepared by the Proctor mould method, conditioned at room temperature, and tested in soaked and unsoaked conditions. Specified curing periods of 7, 14, 28 days were applied for all types of specimens. Some engineering tests were carried out such as proctor compaction, unconfined compressive strength, splitting tensile strength, and the stiffness of stabilized soil. Test results indicated a general decrease in the maximum dry density (MDD) and increased optimum moisture content (OMC) with an increase in RHA content. Adding cement and RHA significantly improved the geotechnical properties of stabilized soils, including compressive strength, splitting tensile strength, elastic modulus. In addition, the combination of 80% soil and 20% RHA and 6% cement can be used as the optimum proportion which satisfied the grade 3 of soils stabilized with inorganic adhesive substances, chemical agents, or reinforced soil for road construction, as indicated in the current Vietnamese standard
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