Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 2005. / Includes bibliographical references.

Thesis (M.S.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (Sept. 18, 2006). Thesis advisor: Jack F. Wasserman. Vita. Includes bibliographical references.

Thesis (M. S.)--Texas A&M University, 2005. / "Major Subject: Safety Engineering" Title from author supplied metadata (automated record created on Apr. 27, 2007.) Vita. Abstract. Includes bibliographical references.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

Division of Policy Research and Analysis, National Science Foundation under Grant no. OEP 76-00284

Bibliography: leaves 101-104. Explores risk assessment of dams, a fundamental approach for dam safety measurement, providing a base on which all safety assessment and any appropriate regulation should be developed. Includes an overview of the relevant literature; an example of the application of this method by the South Australia Water Corporation; and it is also applied to the Wadi Al Jizzi Recharge Dam in the Sultanate of Oman. Conclusions and recommendations are presented on the applicability of risk assessment of dams method in the Sultanate of Oman.

A study was made of the hazard presented by, and the risks associated with, the road and rail transport of conventional explosives. Its purpose was firstly to review the transport environments associated with the hazardous goods and in particular conventional accident and carriage of explosives. Secondly, to identify and assess those stimuli present in transport and accident environments which are liable to cause accidental initiation of explosives. Thirdly, to identify explosion consequence models suitable for the assessment of injury and damage suffered by roadside and rail-side populations as a result of explosion. Finally, to apply and develop a risk assessment methodology capable of identifying, quantifying, evaluating and monitoring individual and societal risks. The study formulates a basic methodology for the assessment of transient hazards and more specifically, a methodology suitable for quantitative risk assessment of the road and rail transport of conventional commercial and military explosives.

Doctor of Philosophy / Department of Civil Engineering / Sunanda Dissanayake / Setting an appropriate speed limit is necessary to provide safe and efficient traffic operation for all road users. It must also be acceptable to the public and enforceable by police. Lower-than-required speed limits may make the majority of drivers non-compliant, whereas higher speed limits may increase the number of crashes together with related injuries and fatalities. In 2011, the speed limit on a number of freeway segments in the state of Kansas increased from 70 to 75 miles per hour. The objective of this study is to evaluate the safety effects of freeway sections affected by speed limit change in Kansas. Sections where the speed limit changed from 70 mph to 75 mph and other comparable sections where the speed limit remained at 70 mph without any change, were identified. Details of the crashes by severity level for three years before (2008-2010) and three years after (2012-2014) the speed limit change were collected using the state crash database. In order to get a general understanding, characteristics of crashes such as night time versus daytime, number of trucks involved, weather conditions, driver’s gender, and such were considered. Furthermore, several crash contributory causes were also investigated before and after the speed limit changes. In order to evaluate the safety situation, three methods were utilized: 1) Empirical Bayes (EB) observational before-and-after studies, 2) before-and-after method with comparison group, and 3) cross-sectional method using the Negative Binomial (NB) regression model. The evaluation was conducted to see if the speed limit change has caused an increase in total crashes or fatal and injury crashes. In regard to speed analysis, the t-test was applied to see whether significant increases in the 85th percentile speed were observed between before-and-after conditions. Since the sample size was large, the Kolmogorov-Smirnov (K-S) test was also conducted to see if there was any difference between two sets of speed data distributions in the before period compared to the after period. By performing the EB before-and-after study, it was seen that total crashes increased by 16 percent, while using the before-and-after method with the comparison group showed around 27 percent increase in total crashes. Total crash increases were statistically significant according to the EB method, and the before-and-after method with the comparison group. On the other hand, fatal and injury crashes increased by 35 percent based on the before-and-after with the comparison group after the speed limit change. This increase was statistically significant, but the EB method results indicated no increase for fatal and injury crashes when the speed limit was raised to 75 mph. Further, cross-sectional study results showed the speed limit increase had a greatly significant effect on total crashes, an increase of 25 percent; and it was also significant for fatal and injury crashes with those increasing by 62 percent, which is the highest amount of increase compared to the EB method and the before-and-after method with the comparison group. The t-test results showed a five mph increase in the speed limit caused statistically significant increase in 85th percentile speed for the sections affected by speed limit change. However, there was also an increase for the sections without a speed limit change, but this was due to large sample sizes of speed data in the before-and-after period. The K-S test results also depicted the speed distribution of treated sites during the after period was different than the before period. Considering night time crashes versus daytime crashes also showed that there was 1 percent statistically significant increase in the night time crashes compared to daytime crashes after the speed limit increase. There were also more trucks involved in crashes after the speed limit increase. Further, the percentage of adverse weather crashes also decreased by 6 percent for treated sites and 18 percent for non-treated sites. Overall, understanding these results will help with future speed limit adjustments on freeways.

Explosion suppression system design has relied historically on the validity of Hartmann apparatus explosibility test data, and on interpolation from available suppression system test data. This research has identified improved methods of explosion hazard assessment and suppression system efficacy assessment, from a study of explosion propagation, suppressant action, and discharge of suppressors. The controversy over the validity of Hartmann dust explosibility data was resolved. It was found that the ignition methodology was responsible for the uncertainly of Hartmann data. A 43dm[3] spherical explosion test apparatus was developed which provided more useful explosibility data. The influence of turbulence on explosion hazards was recognised and an empirical measure of turbulence level was defined. Systematic trials with suppressed and unsuppressed explosions were undertaken in a 1m[3] apparatus. The results of these trials provided the foundation for the development of a mathematical model of explosion suppression. A 6.2m[3] explosion test facility was set up in alignment with the requirements of a proposed International Standard. Explosion and explosion suppression trials in this apparatus substantiated the model. Certain artefacts were identified in 6.2m[3] quiescent gas explosions. An interactive computer program based on the model for explosion suppression was tested and proved. The work has culminated in the establishment of a large scale explosion test facility in the UK. The effectiveness of three suppressants, Halon 1011, water, and mono-ammonium phosphate powder, against both gas and dust explosions was established experimentally . The influence of suppression system detection pressure and explosion suppressor discharge characteristics on the resultant suppression system effectiveness was determined experimentally. A computer model of explosion suppression has emerged which provides an improved level of confidence in adjudging the performance of explosion suppression measures. Areas for further work include larger scale explosion and explosion suppression trials and a study of artefacts identified with large volume quiescent gas explosions.

A small percentage of wheelchair users are unable to transfer from their wheelchair to a vehicle during transportation. Reasons for an occupant to remain in the wheelchair during transport may be the inability to safely transfer to a vehicle seat, the occupant's requirement of a specialist postural management wheelchair seating system or reliance on life support equipment attached to the wheelchair. The Rehabilitation Engineering Unit at Rookwood Hospital deal with people who require either a specialist postural support wheelchair seating system, life support equipment or both. To cater for such equipment the wheelchairs have to be modified to some degree and sometimes completely custom made. In performing modifications to the wheelchairs the Rehabilitation Engineering Unit take on the manufactures responsibilities, one of which is to ensure that the wheelchair is safe for use in transport. Standard crash tests for production wheelchairs are destructive so are impractical to use for bespoke wheelchair designs meaning that the Clinical Engineers at the Hospital have to rely on their best engineering judgement as to whether a wheelchair design is crash worthy or not. It was proposed that by using computer crash simulation techniques an informed judgement of the crashworthiness of the bespoke wheelchair designs could be attained. A series of computer models of occupied wheelchairs were created and validated against physical crash data performed on surrogate wheelchairs. These validated wheelchair computer models were then used to examine a series of different crash scenarios that provided the Clinical Engineers at Rookwood hospital with an informed process for virtually assessing the crashworthiness of their wheelchair designs. The validation results showed that the wheelchair crashworthiness could feasibly be predicted by computer simulation. This thesis concluded that attaching equipment to the wheelchair can increase both its horizontal displacement and the forces on the tiedowns securing the wheelchair to the vehicle chassis. Skewed impact simulations also highlighted the poor lateral restraint ability of the 4-point webbing tie-down system and also the importance of sufficient lateral support on the wheelchair for occupant protection.