Role in preneoplast progression and transformation.

Various North American transportation agencies have implemented several preventative maintenance techniques to improve pavement performance and safety. The Region of York, located north east of Toronto, Ontario, has been resurfacing and remedying pavements with microsurfacing treatments to improve the pavement surface conditions. Often times these maintenance methods were selected because they seemed the most appropriate given a budget constraint however little was known if these treatments impacted road safety. The Region of York made their road and safety data accessible for the purpose of this research. Thus the focus of this thesis is to gain an understanding of how microsurfacing and resurfacing treatments impact road safety to help the Region of York and potentially other jurisdictions make more sound decisions when selecting pavement maintenance treatments. Road related fatalities account for 90 percent of transportation related deaths in Canada despite safety measures such as stronger safety laws and public awareness campaigns. There is a need for engineers to think outside of the box and look at other ways to improve road safety. Given the high costs to society for crashes it only seems logical that safety should be a part of a preventative maintenance decision making process. A fair amount of research has been done on the influence of pavement friction on traffic safety; however no studies were uncovered that examined how microsurfacing (a treatment designed to improve the frictional properties of pavement) affected safety. This study accomplishes five research objectives based on the needs of the Region of York and past experience: 1. Establishes that there is a statistically significant relationship between microsurfacing treatments and safety for specific traffic conditions using a before-after analysis 2. Determines that there is a statistically significant relationship between resurfacing and safety under specific traffic conditions using a before-after analysis 3. Illustrates the need and value added if there is better cohesion between road data and safety data 4. Demonstrate that safety has a role to play in pavement management, especially regarding preventative maintenance strategies and offers guidance on how to approach the integration using York Region as a case study 5. Develops a concept decision making framework that demonstrates how safety data should be considered in pavement maintenance decision making at both the network level applying life cycle costs and project level using decision making flowcharts. These tools while specific to York Region can be adopted in jurisdictions with similar characteristics The study concludes that microsurfacing and resurfacing safety effects are sensitive to the influence of treatment year data (which may be an anomaly period) and average annual daily traffic (AADT) per lane. The findings of this study have opened the door to additional research; integration of safety under the pavement umbrella seems logical and yet has barely been explored. Recommendations that have resulted from this work deal with data collected and how it is managed; analysis methodology and additional opportunities for further study; and finally how to optimize the application of the findings to best serve engineers that are involved in the maintenance decision making process. There is much potential for further research in the area of safety within a pavement management framework and the resultant studies will have a tremendous benefit to society.

Today, railroad companies transport many varieties of dangerous goods (DG). Train derailments, especially those involving DG, can be catastrophic in terms of loss of life and environmental damage. In North America, the transportation of DG is governed by regulations published by the Canadian and United State's governments. While the regulation is important in terms of providing overall guidelines, they do not address the problem of optimally positioning DG cars in terms of their potential for derailment and the associated risks. Currently, most rail yard operations do not consider the potential effect of the position of DG cars on the risk of derailment. This research is concerned with the problem of how to place DG cars in a train in the train assembly process so that the overall derailment risk can be minimized. The approach considers both the probability of railway cars derailing en route by position as well as the time associated with additional operations in the rail yard. This work has resulted in a useful decision support tool for assisting rail yard operation managers to achieve an optimum trade-off between derailment risk and operating costs in assembling trains. The merits of this new car placement model are illustrated through a case study of a real railway corridor that connects Barstow Yard in California to Corwith Yard in Chicago over 2100 miles and involves a range of track features. The case study demonstrates that the proposed risk minimization strategy could be implemented with minimal rail yard operation cost.

Safety is very important for our society. In contrast, it is hard to define what this term really means. Nevertheless, one area that is considered important for safety involves accident prevention. Many methods exist within this area which aims at preventing accidents from happening. One accident prevention method is called ‘The Safety Scanning Tool (SST)’. The study conducted in this thesis aimed at exploring whether the SST could improve the safety understanding of experts from the domain of aviation. The term ‘safety understanding’, as it is used in this thesis, refers to the understanding of central scientific concepts underlying safety. These concepts relate to the area of accident prevention and they were the results of a literature study on safety. Thus, the safety understanding was addressed on two levels of abstraction. The first general abstraction level concerned the basic assumptions for studying an organization’s safety culture relating to Schein’s (1992) framework cited by Guldenmund (2000). This relates to the area of accident prevention in a more general way. The second more specific abstraction level regarded 21 different safety issues important for accident prevention. These originated from the area of resilience engineering. Furthermore, this study was structured as a field experiment using a pre-post test and a within-group design.  In order to measure the different experts’ safety understanding, the data were gathered with the help of two surveys before and after the experts’ used the SST. The SST was applied to two groups of experts. In the first group, they were six people, and, in the second 16. The questions in the surveys were created with the help of the above mentioned literature study on safety. The results were analyzed with the help of the statistics program SPSS. In addition, the results were analyzed with the help of sources from academic literature. These were used in order to determine whether there was an improvement of the safety understanding or not. Based on the results from this study, it can be concluded that undergoing the SST caused several improvements of the experts’ safety understanding. These improvements were found in both groups of experts and on both abstraction levels of the safety understanding. However, one result relating to the basic assumption level in the second group of experts could be interpreted both as an improvement and as a decrease of the safety understanding. The results of this study indicate not only that the SST has the ability to detect safety problems in an early state, before they can develop to the outcome of an accident. It has also the ability to enhance its user’s safety understanding relating to factors important for accident prevention.

Whole-body vibration is an important problem facing operators of off-road vehicles. Research has shown that operators exposed to low-frequency whole-body vibration can experience temporary and even permanent injuries. One solution to this problem is to develop an active seat capable of canceling the vibrations felt by the operator. Several passive, semi-active, active, and fully active seats have been designed and built to address this problem. Furthermore, controllers have been developed to optimize the seat performance. Vibration cancellation seating systems seem to be a promising and practical way to reduce the effects of whole-body vibration. To extend developments in this area, a Hyper-Active seat has been designed and built at the Georgia Institute of Technology. The seat utilizes a 3 Revolute-Prismatic-Revolute (RPR) parallel manipulator design which allows for the independent control of the vertical, horizontal and pitch angle directions. The seat is powered using three hydraulic actuators which are controlled using MATLAB's Simulink, xPC Target, and Real-Time Workshop. Controllers were developed to control the position of the seat, as well as cancel unwanted vibration. To test the performance of the Hyper-Active seat, the system identification of the seat was undertaken using open-loop forcing functions. The seat was evaluated in each degree of freedom to understand the potential of the seat to cancel harmful vibration. In addition to reducing harmful vibrations, the seat can double as a safety seat to reduce injuries during a frontal collision. If the front edge of the seat bottom can be raised very quickly, then the forward motion of the passenger can be reduced during a crash. An optimal method for performing this motion is developed.

China Steel Corporation (CSC) has introduced OHSAS 18001 system since 2000, and has acquired good performance and credits, but it seems hard to get further progress in performance. One of the major reasons is that industrial safety awareness does not take root in every employer¡¦s mind. So it is important to make an all-purpose safety concept environment. In 2011, Safety-Caring program was put into action plant widely to build safety culture. This study focuses on the effect of safety management by promoting safety caring activities in steel-making plant. It hopefully improves the safety performance through verification of practical experiment according to theoretical analysis. The study processes and conclusion are as followings: 1. Two rounds of questionnaires were issued; the first one was done about one year later of safety caring project started, this questionnaire was to understand the effect of safety caring program in steel plant. The second one was to evaluate the key factors of success to run safety caring program, and the later questionnaire was issued about five months later following the first one. 2. The culture of CSC is based on the kindheartedness and humanity priority. So safety caring program is suitable to build an all-purpose safety culture in CSC. 3. The results from the two rounds of questionnaires show the highly approval of safety caring program. The successive safety education, the promise of the authority, the proclamation of the labor union and steel plant, and the safety knowledge sharing consistently promoted, therefore, the safety performance is getting higher. 4. The major factors of running safety program are: active safety caring, the promise of the authority, personal safety knowledge, the proclamation and the support of the labor union, and the notification performance of steel-making plant. The factor of the promise of the authority is the most outstanding. On the other hand, the following factors are not so obvious, such as: safety management system, safety feeling, service leading, commanding leading, rewards and punishments, working pressure, and income satisfaction. 5. The more the safety caring is done, the more approval of safety program, and the more willingness to obey the safety rules. It is evident that keeping the promotion of safety activities can lower the industrial accidents.

Increased consumption combined with increasing risk to foodborne illnesses makes it necessary to identify potential sources of contamination in the food chain and apply intervention processes that prevent/minimize the risk of contamination. The current study investigated the effect of the decontamination treatments with chlorine and lactic acid on the survival of Salmonella on the rind and stem scar portions of inoculated mangoes. The presence of the pathogen in the treatment water, internalization and the effect of the treatments on the quality of the fruit were also determined. For scar (hydrothermal), a 3.0 log reduction was obtained for control and additional reductions of approximately 2.2 and 1.3 log cycles were obtained with lactic acid and chlorine respectively. Data indicates reduction in pathogen population in cooling for all the treatments except two (Control – increase of 0.3 logs, LA-LA – increase of 0.3 logs). A 0.5 log reduction was obtained for the control (initial - 4.4 log10 CFU/10 cm2) and additional reductions of approximately 1.7 and 1.3 log cycles were obtained for treatments with lactic acid and chlorine respectively during hydrothermal treatment on the rind. For cooling, lactic acid and chlorine gave an overall reduction of approximately 1.3 and 1.4 logs respectively compared to control. Although Salmonella was not detected in the core stem tissue by direct plating method for most of the samples, it was detected after the enrichment method. The pathogen was detected on the rind, stem scar and the stem tissue for most of the samples for as long as 12 days. Salmonella was detected in treatment water with and without sanitizers after dipping mangoes. Lactic acid was found to be more effective in reducing pathogen population compared to chlorine in all the treatment combinations; however, the sensory aspects (color and texture) of the fruit were compromised.

The growth of vehicle travel in the United States has accelerated wear on the interstate highway system leading to frequent pavement repair and rehabilitation projects. The presence of work zones not only causes traffic congestion and backup but also increases the crash risk. Therefore, the FHWA (Federal Highway Administration) has allotted a significant amount of funds to improve work zone traffic safety and operations. This thesis compares truck and automobile crash characteristics in work zones with those of non-work zones and thus identifies engineering countermeasures to improve work zone truck safety. The researcher used a contingency analysis approach in this study. First, he categorized the North Carolina crash data using different variables. Once categorized, the Breslow-Day test is used to compare the odds of truck and automobile crashes between work zones and non-work zones. Overall, the researcher did not find a significant difference between odds of truck and automobile crashes compared to previous studies. The researcher believes that the difference in results between the present study and the previous studies could either be due to differences in the approach used or better truck management techniques employed by the North Carolina DOT (Department of Transportation). The researcher also identified that the maintenance projects performed during the day had a significantly higher odds of truck crashes relative to that of automobiles in work zones compared to control sections when workers were present, either with a lane closure or without a lane closure. The researcher believes that the results from the day maintenance projects and its subcategories are the key findings of this study. Therefore, these key findings are used to identify the possible reasons and countermeasures for any disproportionate change in truck to automobile crashes. The identified list of countermeasures includes the use of law enforcement, a smart work zone system, a dynamic late merge system, CMS (Changeable Message Signs), speed display signs, and a CB (Citizen Band) Wizard. These countermeasures were checked for cost effectiveness using a benefit cost (B/C) analysis. The researcher found that law enforcement, smart work zones with costs lower than or equal to half a million dollars, CMS, speed display signs, and the CB Wizard have B/C ratios greater than one and seem to be worthwhile for deployment in work zones. Smart work zones with significantly higher costs of 2.5 million dollars, for example, could be deployed using a more detailed analysis of work zone characteristics. Finally, dynamic late merge system could be used if the site conditions indicate a crash reduction potential of at least 10 – 15 percent.

In accordance with the federally mandated Highway Safety Improvement Program (HSIP), every state is required to “develop and implement, on a continuous basis, a highway safety improvement program which has the overall objective of reducing the number and severity of crashes and decreasing the potential for crashes on all highways” (FHWA, 1979). The federal government via the HSIP provides a significant amount of funding that allows every state to improve the safety of their highway network. With such large amounts of federal funds involved, it becomes essential that state transportation agencies take appropriate measures to utilize these funds in the most cost effective manner. As part of this program, the Texas Department of Transportation (TxDOT) uses a formula known as the “Safety Improvement Index” (SII) for identification, ranking and selection of eligible projects. The SII is in essence used to rank potential projects by giving priority to projects that have a higher benefit-cost (B/C) ratio. Since the SII has not been updated within the last two decades, there is a need to determine whether the current formulation needs to be revised or updated. This concern has been reported in the literature. The objective of this thesis is to evaluate the SII in its current functional form and its usefulness to rank and prioritize projects for safety improvement. The evaluation procedure proposed in this thesis uses sensitivity analyses to study the effects of different input variables on the SII. The sensitivity analysis is performed with respect to five critical variables chosen on the basis of a literature review. The five variables studied are the Interest Rate, Removal of PDO Crashes, Crash Reduction Factors, Crash Rates, and Crash – Flow Relationship. The focus of the evaluation is to compare the ranking of projects with respect to changes in the value of these input variables. The ranking are evaluated using various statistical methods, such as the Spearman Rank Order Correlation Test and Kendall’s Tau Test. The results of the analysis indicated that, although changes in the value of input variables affect the SII output, the ranking of projects is usually not affected, with the exception of the crash reduction factor variable. Hence, the same projects will be selected for safety improvement, even if different values are used in the SII. Therefore, it is recommended that the current formulation of the SII and the value of input variables used in the formula be retained by TxDOT for prioritizing safety improvement projects. However, it is suggested to examine the accuracy and uncertainty associated with reduction factors, since in some cases they were found to affect the ranking of projects.

Intersections are the most complex locations in a traffic system and are likely to have a higher crash count than any other location in the system. Intersection safety is related to traffic operations, such as traffic signal and approaching volume. The objective of this study is to determine the contributing factor for left-turn crashes at signalized intersections by a statistical modeling process and to develop crash prediction models. Potential contributing factors representing the characteristic of a left-turn operation were identified and considered for inclusion in crash prediction models. HCS (Highway Capacity Software) 2000 was utilized for computing some traffic indicators such as volume to capacity ratio for potential inclusion in the models. Three years of crash data were collected in the College Station area. The Signal timing and Volume data were obtained from public works in College Station. The volume data was sorted into three time periods and signal timing data were obtained for three different time periods: AM, noon, and PM. The division of time periods results from timing plans being changed for different periods. Relationship between crash count and each factor was explored to identify whether the factor has the potential to influence the crash count. Afterwards, the prediction models were developed using the negative binomial structure because of many zero samples. Akaike Information Criteria was used for selecting the model having the best fit. Wald tables provided that variables have significance in affecting the left-turn crash count. Left-turn type, sequence, volume, control delay, and post speed limit were identified as significant factors impacting left-turn crash count at a signalized intersection.