This paper investigates vehicle dynamic response for the increasingly common manoeuvre over single speed bumps, which is a non-trivial complex motion. One major aim of the study is to investigate the effect of the anti-roll bar upon vehicle body dynamics, while negotiating such traffic calming features. Numerical predictions are made with an intermediate vehicle model, whose results conform well to the actual vehicle tests. These results seem to suggest that events caused by truncated speed bumps can have implications for design of anti-roll bars from a ride comfort viewpoint, over and above the usual requirements dictated by safe vehicle handling.
The paper presents a six-degree-of-freedom (6-DOF) multi-body vehicle model, including realistic representation of suspension kinematics. The suspension system comprises anti-squat and anti-dive element. The vehicle model is employed to study the effect of these features upon combined bounce and pitch plane dynamics of the vehicle, when subjected to bump riding events. The investigations are concerned with a real vehicle and the numerical predictions show reasonable agreement with measurements obtained on an instrumented vehicle under the same manoeurves
A 59-year-old man with a background of chronic obstructive pulmonary disease was diagnosed with a large mixed laryngopyocele that was successfully drained and marsupialized endoscopically using suction diathermy without requiring tracheostomy. Because of the rareness of the case, we performed a systematic review. Of 61 papers published between 1952 and 2015, we reviewed 23 cases written in English that described the number of cases, surgical approaches, resort to tracheostomy, complications, and outcomes. Four cases of laryngopyoceles were managed endoscopically using a cold instrument, microdebrider, or laser. Eighteen cases were operated on via an external approach, and 1 case applied both approaches. One of 4 endoscopic and 10 of 18 external approaches involved tracheostomy. Management using suction diathermy for excision and marsupialization of a laryngopyocele has never been reported and can be recommended as a feasible method due to its widespread availability. In the presence of a large laryngopyocele impeding the airway, tracheostomy may be averted in a controlled setting.
Despite the several benefits of modifying bitumen with polymer; it is increasingly becoming difficult to ignore concerns about its high energy consumption and fume emissions during asphalt production. Previous studies found on natural rubber (NR) modified binders applied it as a hot mix asphalt (HMA), however in recent years there has been increasing interest in warm mix asphalt. This research explores the possibility of applying NR in warm mix asphalt (WMA) by comparing the physical properties of cup lump rubber modified bitumen with and without warm mix additive. Four percentages (2.5%, 5.0%, 7.5% and 10%) of Cup lump rubber (CLR) was used to modify 60/70 penetration grade bitumen, while three percentages (0.3%, 0.4%, and 0.5%) of Evotherm chemical was added to produce warm cup lump modified bitumen (WCMB). Storage stability, penetration, softening point, viscosity, ductility, and elastic recovery tests were conducted to determine the effect of CLR and Evotherm. The results show that storage stability and viscosity of the cup lump modified bitumen heavily depends on the CLR content. While a positive correlation exists between the increase in binder stiffness with increasing mixing and compaction temperatures. The addition of 0.5% Evotherm reduces the viscosity by 14%. Contrary to expectations, CLR was found to reduce the ductility of the bitumen while the presence of Evotherm in the blend increases the softening point. The use of warm NR modified bitumen in road construction is expected to lower the asphalt production temperature, carbon emission and cost without compromising the performance of the mix.
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