Assessing the Performance of Reconditioned Railroad Tapered-Roller Bearings Used in Freight Rail Service

The rail industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). Bearings that are removed from service are sent to specialized facilities where they undergo a reconditioning process before the bearings can be returned to rail service. The reconditioning process has been used for decades although there has been no previous study on the effectiveness of the reconditioning process on defective bearings that were removed from service. This persuaded the researchers from the University Transportation Center for Railway Safety (UTRCS) and the Transportation Technology Center Inc. (TTCI) to design an experimental study to assess the efficacy of the reconditioning process. The work in this thesis summarizes the results of the temperature and vibration signatures of twenty bearings. To assess the effectiveness of the reconditioning process, twelve of the twenty bearings were tested pre- and post-reconditioning process. The remaining eight bearings were tested post-reconditioning for a complete service life testing consisting of approximately 400,000 km (~250,000 mi) at the UTCRS testing facility

The relationship between vertical teaming in science and student achievement as reported in the academic excellence indicator system (AEIS) at selected public schools in Bexar County, Texas

The purpose of this study was to examine the relationship between vertical teaming in science and student achievement. This study compared student achievement of campuses implementing vertical teaming with schools that do not practice vertical teaming. In addition, this study explored the relationship between selected demographic variables and vertical teaming using Grade 5 Science TAKS results in the Academic Excellence Indicator System (AEIS). Campus demographic variables such as economically disadvantaged, minority students, English language learners, student mobility, and experienced teachers were researched. A call-out yielded 168 responses. With the exclusion of the 12 campuses, a total of 156 participating campuses from 18 traditional school districts remained. Campuses employing vertical teaming were self-identified on the basis of having implemented the process for two or more years. The gain in percent mastered for Science TAKS scores from 2004 to 2007 was used as the Science TAKS score variable. Results indicated that there was no significant difference in student achievement in science for campuses practicing vertical teaming and campuses that did not. The twoway ANOVA was used to measure the relationship between the independent variables (vertical teaming and campus demographic variables) on the dependent variable (student achievement on Science TAKS). The results suggested that campuses having low percentages of economically disadvantaged students statistically gained more on the Science TAKS than campuses that have high percentages of economically disadvantaged students irrespective of vertical teaming practices. In addition, campuses that have low percentages of minority students statistically gained more on the Science TAKS than campuses that have high percentages of minority students despite vertical teaming participation. Recommendations include districts, state, and federal agencies providing campuses with a high percent of economically disadvantaged students with more resources and more flexibility in using those resources. Recommendations for further study included a replication of the study that takes into account the degree of implementation of vertical teaming

Participatory land planning in the region of Madrid (Spain) : an integrative perspective

The landscape and institutional changes in the region of Madrid over the last three decades have shaped current decision-making process in the planning system. Madrid is characterised by the intensive use of land and a range of stakeholders related to the stratified administrative structure, which generates social & environmental conflicts. This research links different themes such as territorial planning and governance, using an integrative perspective to search for sustainable strategies. The appreciative systems approach, based on conceptual modelling, is used to understand the complex processes involved. The modelling process provides a valuable tool of simplifying the complexity. The development of the conceptual model is divided into two processes; the first model exercise is an abstraction of the decision-making process in land planning. Attributes of the planning and governance systems in Madrid are taken into account. Later, this conceptualization is complemented with quantitative data from the 1950's. This thesis harmonises the quantitative method with the discursive model to understand the complexity of the emergent conflicts in regional land planning and management. Notions such as collaborative planning, adaptive management and multilevel governance, which have recently become fashionable, provide the theoretical discussion. A stakeholder engagement exercise was carried out to encourage the participation of stakeholders in the policy-making process. This thesis suggests a set of future scenarios, alternative policy options, under a common framework of sustainability. The seven policy interventions are detailed in a booklet written in Spanish and English: "Tozvards sustainable land planning in the Autonomous Community of Madrid: Guidelines and Recommendations". A simulation model - decision support tool - was used to explore these scenarios and enhance stakeholder participation. This research was instrumental in helping stakeholders communities to adapt to emerging circumstances and changes in the regional planning process.EThOS - Electronic Theses Online ServiceTiGrESS project (EU-FPV) : ISBP -Integrative Systems: Boundary Problems- project (NEST-043199)GBUnited Kingdo

Becoming Digital: Enacting Digital Transformation in Construction Projects

Digital transformation is often conceptualised as an accomplished event; however, conceptualising it as something that organisations accomplish does not capture the features of the change process. In this study, we analyse digital transformation at the inter-organisational level (i.e. construction projects context) and conceptualise it as a dynamic change process that people enact. More specifically, we investigate the implementation of building information modelling (BIM) in construction projects, adopting a practice-based approach to explore the change process and how BIM is institutionalised in practice. We propose a preliminary conceptual model of the institutionalisation of BIM as a structuration process. Based on ethnographic data, our findings revealed two main characteristics of the process of institutionalising BIM in projects, i.e. path dependency and contingency upon institutional fields. Through our findings, we offer insights into both the literature and practice on how digital transformation in project-based contexts occurs in practice

An Analysis of the Efficacy of Wayside Hot-Box Detector Data

Wayside hot-box detectors (HBDs) are devices that are currently used to monitor bearing, axle, and brake temperatures as a way of assessing railcar component health and to indicate any possible overheating or abnormal operating conditions. Conventional hot-box detectors are set to alarm whenever a bearing is operating at a temperature that is 94.4°C (170°F) above ambient, or when there is a 52.8°C (95°F) temperature difference between two bearings that share an axle. These detectors are placed adjacent to the railway and utilize an infrared sensor in order to obtain temperature measurements. Bearings that trigger HBDs or display temperature trending behavior are removed from service for disassembly and inspection. Upon teardown, bearings that do not exhibit any discernible defects are labeled as “non-verified”. The latter may be due to the many factors that can affect the measurement of HBDs such as location of the infrared sensor and the class of the bearing among other environmental factors. A field test was performed along a route that is more than 483 km (300 mi) of track containing 21 wayside hot-box detectors. Two freight cars, one fully-loaded and one empty, and one instrumentation car pulled by a locomotive were used in this field test. A total of 16 bearings (14 Class F and 2 Class K) were instrumented with K-type bayonet thermocouples to provide continuous temperature measurement. The data collected from this field test were used to perform a systematic study in which the HBD IR sensor data were compared directly to the onboard thermocouple data. The analyses determined that, in general, HBDs tend to overestimate Class K bearing temperatures more frequently than Class F bearing temperatures. Additionally, the temperatures of some bearings were underestimated by as much as 47°C (85°F). Furthermore, the HBD data exhibited some false trending events that were not seen in temperature histories recorded by the bayonet thermocouples. The findings from the field test suggest that HBDs may inaccurately report bearing temperatures, which may contribute to the increased percentage of non-verified bearing removals. To further investigate the accuracy of the wayside detection systems, a dynamic test rig was designed and fabricated by the University Transportation Center for Railway Safety (UTCRS) research team at the University of Texas Rio Grande Valley (UTRGV). A mobile infrared sensor was developed and installed on the dynamic tester in order to mimic the measurement behavior of a HBD. The infrared temperature measurements were compared to contact thermocouple and bayonet temperature measurements taken on the bearing cup surface. The laboratory-acquired data were compared to actual field test data, and the analysis reveals that the trends are in close agreement. The large majority of temperature measurements taken using the IR sensor have been underestimated with a similar distribution to that of the data collected by the HBDs in field service

An investigation into wayside hot-box detector efficacy and optimization

Wayside hot-box detectors (HBDs) are devices used to assess the health of railcar components including bearings, axles, and brakes by monitoring their temperatures. HBDs use infrared (IR) sensors to record the temperatures of railroad bearings. Bearings that trigger an alarm or exhibit warm trending are removed and sent for inspection. In many cases, no discernable defects were found in the flagged bearings. Motivated by this finding, an investigation was conducted which included performing a controlled field test as well as exhaustive laboratory testing utilizing an HBD simulator. Data acquired from field and laboratory testing was used to evaluate the accuracy and efficacy of wayside HBDs. The results suggest that the scanning location on the bearing cup significantly affects the temperature measurement. Different calibrations for the field- and laboratory-acquired data were also explored. An optimized calibration technique along with proper IR sensor alignment can markedly improve the accuracy of HBD measurements