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Interaction analysis of a pregnant female uterus and fetus in a vehicle passing a speed bump
, Article Journal of Biomechanics ; Volume 118 , March , 2021 ; 00219290 (ISSN) ; Ahmadian, M. T ; Mohammadi, H ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Pregnant vehicle occupants experience relatively large acceleration when the vehicle passes a speed-bump. In this paper, the effect of such sudden acceleration on a pregnant uterus is investigated. A biomechanical model representing the fundamental dynamic behaviors of a pregnant uterus has been developed. The model relates to the 32nd week of gestation when the fetus is in head-down, occipito-anterior position. Considering the drag and squeeze effects of the amniotic fluid, we derive a comprehensive differential equation that represents the interaction of the uterus and fetus. Solving the governing equation, we obtain the system response to different speed-bump excitations. Using the fetal...
A comparison of light-duty vehicles' high emitters fractions obtained from an emission remote sensing campaign and emission inspection program for policy recommendation
, Article Environmental Pollution ; Volume 286 , 2021 ; 02697491 (ISSN) ; Safavi, S. R ; Hosseini, V ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Urban transportation is one of the leading causes of air pollution in big cities. In-use emissions of vehicles are higher than the emission control certification levels. The current study uses a roadside remote sensing emission monitoring campaign to investigate (a) fraction of high emitters in the light-duty vehicle (LDV) fleet and their contributions to the total emissions, (b) emission inspection (I/M) programs' effectiveness, and (c) alternate fuel (natural gas) encouragement policy. LDVs consist of passenger or freight transport vehicles with four wheels equivalent to classes M1 and N1 of European union vehicle classifications. The motivation is to assess the current emission inspection...