Characterisation of nanoparticles resulting from different braking behaviours

Brake wear particulate matter (PM) may provoke cardiovascular effects. A system was developed to expose cells to airborne PM from brakes. Six car models were tested, each with full stop and normal deceleration. PM numbers, mass and surface, metals, and carbon compounds were measured. Full stop produced higher PM number and mass concentrations than normal deceleration (up to 10 million particles/cm3 in 0.2 m3 volume). 87% of the PM mass was in the fine (100 nm to 2.5 ìm) and 12% in the coarse (2.5 to 10 ìm) fraction, whereas 74% of the PM number was nanoscaled (ultrafine < 0.1 ìm) and 26% fine PM. Elemental concentrations were 2,364, 236, and 18 ìg/m3 of iron, copper and manganese, respectively, and 664 and 36 ìg/m3 of organic and elemental carbon. PM-release differed between cars and braking behaviour. Temperature and humidity were stable. In conclusion, the established system seems feasible for exposing cell cultures to brake wear PM. [Authors]

Analysis of emergency braking performance with particular consideration of temperature effects on brakes

During vehicle deceleration due to braking there is friction between the lining surface and the brake drum or disc. In this process the kinetic energy of vehicle is turned into thermal energy that raises temperature of the components. The heating of the brake system in the course of braking is a great problem, because besides damaging the system, it may also affect the wheel and tire, which can cause accidents. In search of the best configuration that considers the true conditions of use, without passing the safety limits, models and formulations are presented with respect to the brake system, considering different braking conditions and kinds of brakes. Some modeling was analyzed using well-known methods. The flat plate model considering energy conservation was applied to a bus, using for this a computer program. The vehicle is simulated to undergo an emergency braking, considering the change of temperature on the lining-drum. The results include deceleration, braking efficiency, wheel resistance, normal reaction on the tires and the coefficient of adhesion. Some of the results were compared with dynamometer tests made by FRAS-LE and others were compared with track tests made by Mercedes-Benz. The convergence between the results and the tests is sufficient to validate the mathematical model. The computer program makes it possible to simulate the brake system performance in the vehicle. It assists the designer during the development phase and reduces track tests.

The Ca2+-activated K+ channels play a braking role in locus coeruleus neurons during CO2 exposure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Driving and emergency braking may be impaired after tibiotalar joint arthrodesis: conclusions after a case series.

PURPOSE To assess whether reaction time (RT) and movement time (MT), as the two components of the total brake response time (TBRT) and brake force (BF) are different in patients with a foot joint arthrodesis in comparison to controls. METHODS The study was a comparative case series in a driving simulator under realistic driving conditions. Mobile patients without a walker, ≥6 months after surgery who were driving a car and had no neurological co-morbidity, knee or hip joint prosthesis were included in the study. The selection criteria resulted in 12 patients with right tibiotalar joint arthrodesis (TTJA) and 12 patients with another right foot joint arthrodesis (OFJA), who were compared to 17 individuals without any ankle-joint pathology. For TBRT, an empirical safe driving threshold of 700 ms was used. The outcome measures were RT, MT, TBRT, BF and McGuire score. RESULTS MT (p = 0.034) and TBRT (p = 0.026) were longer in TTJA patients in comparison with the controls. Also, more patients with TTJA than patients with OFJA and controls exceeded the safe driving threshold (p = 0.028). The outcomes in OFJA patients and in controls were comparable. The McGuire score was similar between the TTJA and OFJA patients (p = 0.26). CONCLUSIONS Significantly slower MT and TBRT, and significantly more patients exceeding the safe driving threshold, were observed after a tibiotalar-joint arthrodesis in comparison to the controls. Patients with OFJAs were not significantly different from the controls. Driving and emergency braking may be impaired after tibiotalar-joint arthrodesis.

Making Transport Safer: V2V-Based Automated Emergency Braking System

An important goal in the field of intelligent transportation systems (ITS) is to provide driving aids aimed at preventing accidents and reducing the number of traffic victims. The commonest traffic accidents in urban areas are due to sudden braking that demands a very fast response on the part of drivers. Attempts to solve this problem have motivated many ITS advances including the detection of the intention of surrounding cars using lasers, radars or cameras. However, this might not be enough to increase safety when there is a danger of collision. Vehicle to vehicle communications are needed to ensure that the other intentions of cars are also available. The article describes the development of a controller to perform an emergency stop via an electro-hydraulic braking system employed on dry asphalt. An original V2V communication scheme based on WiFi cards has been used for broadcasting positioning information to other vehicles. The reliability of the scheme has been theoretically analyzed to estimate its performance when the number of vehicles involved is much higher. This controller has been incorporated into the AUTOPIA program control for automatic cars. The system has been implemented in Citroën C3 Pluriel, and various tests were performed to evaluate its operation.

Sprint Medley Relay Team 1979, UM Men's Track, Set world record of 3:22 at Michigan Relays in Lansing, braking record set by U-M team in 1976

{L-R: Charles Crouther, Andrew Bruce, Ken Gardner, Tim Thomas]

Sprint Medley Relay Team 1979, UM Men's Track, Set world record of 3:22 at Michigan Relays in Lansing, braking record set by U-M team in 1976

[L-R: Charles Crouther, Andrew Bruce, Ken Gardner, Tim Thomas]

Computer simulation of the effect of cargo shifting on articulated vehicles performing braking and cornering maneuvers. Volume 1: executive summary. Final report.

Federal Highway Administration, Structures and Applied Mechanics Division, Washington, D.C.

Computer simulation of the effect of cargo shifting on articulated vehicles performing braking and cornering maneuvers. Volume 2: technical report. Final report.

Federal Highway Administration, Structures and Applied Mechanics Division, Washington, D.C.

Computer simulation of the effect of cargo shifting on articulated vehicles performing braking and cornering maneuvers. Volume 4: user's manual for TDVS/SLOSH. Final report.

Federal Highway Administration, Structures and Applied Mechanics Division, Washington, D.C.

Computer simulation of the effect of cargo shifting on articulated vehicles performing braking and cornering maneuvers. Volume 3: technical supplement. Final report.

Federal Highway Administration, Structures and Applied Mechanics Division, Washington, D.C.