INVESTIGATION IN REDUCING EXHAUST EMISSIONS FROM TWO STROKE MOTORCYCLES

Test results of reducing two stroke motorcycle emissions with new type carburettors and electronic fuel injection systems are presented. Analyses and comparison between different systems are discussed. The adoption of electronically controlled injection and corresponding electronic control technique is an effective measure of prolonged vitality to improve emissions from two stroke motorcycles. Suggestions about the strategic steps of China′s motorcycle emission control are proposed.

Dynamic Response of Functional Virtual Prototyping of Motorcycle under Combined Excitations

This paper developed 3D product models of motorcycle and engine by UGNX as well as virtual prototyping by ADAMS program with road roughness generated by MATLAB. Under the straight-line running condition, the dynamic responses of motorcycle multibody system to both road and engine excitations were compared with those to only road excitation in terms of vertical acceleration response, amplitude frequency response and power spectral density. The comparisons of simulation data showed that the response due to flat road excitation was around 20 Hz, while that to the combined excitations was in a wide frequency band, of which the major components focused on 10 Hz, 15 Hz, 35 Hz ,70 Hz, 100 Hz and even higher frequencies, reflecting the characteristics of engine excitation based on its unbalanced inertia force and torque. It is concluded that the high fidelity virtual prototyping can simulate the dynamics of motorcycle product well in investigating the vibration and ride comfort performance.

Prevalence and risk factors of alcohol and substance abuse among motorcycle drivers in Fats province, Iran

Purpose： The aim of this present study is to investigate the prevalence of alcohol and substance abuse （ASA） and its relationship with other risky driving behaviors among motorcycle drivers. Methods： This is a cross sectional study which is performed at Shiraz city of Iran. Data from motorcycle drivers were collected using a standard questionnaire in eight major streets at different times of the day. The data includes consumption of alcohol and other substances two hours before driving and some of the risky behaviors during driving. Results： A total of 414 drivers with a mean ±SD age of （27.0 ±9.3） years participated in the study. Alcohol or substance consumptions two hours before driving was significantly associated with risky driving behaviors such as using mobile phone during driving, poor maneuvering, and driving over the speed limit （both p 〈 0.001 ）. It was also associated with carelessness about safety such as driving with technical defects （p 〈 0.001） and not wearing a crash helmet （p 0.008）. Conclusion： Screening for alcohol and substance consumption among motorcycle drivers is an efficient way to identify drivers that are at a greater risk for road traffic accidents.

Scapular fractures and concomitant injuries

Objective： The association of scapular fractures with other life-threatening injuries including blunt thoracic aortic injury is widely recognized. Few studies have investigated this presumed association. In this study, we investigated the incidence of significant associated injuries with scapular fracture and their outcomes. Methods： A retrospective study was conducted from 2005 to 2009 in a level I trauma center in Thailand. All blunt trauma patients were identified. Patients＇ demographics, injury mechanism, associated injuries, Injury Severity Score （ISS）, and survival outcomes were recorded. The manage- ment of associated injuries with scapular fracture was reviewed, and the risk factors for mortality were identified. Results： Among the 7 345 trauma patients admitted, scapular fractures occurred in 84 cases （1.1%）. The mean age was （37.98±15.21） years. Motorcycle crash was the most frequent mechanism of injury, occurring in 51 cases （60.7%）.Seventyour patients （88.1%） suffering from scapular fractures had associated injuries： 5 （6.0%） had significant chest injuries, but none of them had blunt thoracic aortic injury. Two patients （2.4%） with scapular fractures died. Factors determining the likelihood of mortality were： （1） ISS〉25 （LR=8.5, P〈0.05）; （2） significant associated chest injury （AIS〉3, LR=5.3, P〈0.05） and （3） significant associated abdominal injury （AIS〉3, LR=5.3, P〈0.05）. Conclusion： A blunt scapular fracture may not accompany a blunt thoracic aortic injury but it is strongly related to other injuries like chest injury, extremity injury, head injury, etc. If a scapular fracture is found with a high ISS score, high chest or abdomen AIS score, the patient would have a high risk of mortality.