3 resultados para Wire-rope transportation.

em Bucknell University Digital Commons - Pensilvania - USA


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Transportation has contributed to climate change and will most likely be impacted by changes in sea level, temperature, precipitation, and wind, for example. As the risk of climate change impacts become more imminent, pressure for adaptation within transportation agencies to address these impacts continues to rise. The most logical strategy is to integrate consideration of adaptation projects into the long-range transportation planning (LRTP) process. To do this, tools and experience are needed to assist transportation agencies. The Climate Change Adaptation Tool for Transportation (CCATT) is a step-by-step method to evaluate climate change scenarios and impacts, inventory at-risk existing and proposed infrastructure, and assess mitigation practices to identify supporting adaptation efforts. This paper focuses on the application of CCATT to the Mid-Atlantic region using a case study on the Wilmington Area Planning Council (WILMAPCO), the Metropolitan Planning Organization for northern Delaware. The results of the application and case study demonstrate the importance of climate change adaptation practices in long-range transportation planning. DOI: 10.1061/(ASCE)TE.1943-5436.0000515. (C) 2013 American Society of Civil Engineers.

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More than 250,000 hip fractures occur annually in the United States and the most common fracture location is the femoral neck, the weakest region of the femur. Hip fixation surgery is conducted to repair hip fractures by using a Kirschner (K-) wire as a temporary guide for permanent bone screws. Variation has been observed in the force required to extract the K-wire from the femoral head during surgery. It is hypothesized that a relationship exists between the K-wire pullout force and the bone quality at the site of extraction. Currently, bone mineral density (BMD) is used as a predictor for bone quality and strength. However, BMD characterizes the entire skeletal system and does not account for localized bone quality and factors such as lifestyle, nutrition, and drug use. A patient’s BMD may not accurately describe the quality of bone at the site of fracture. This study aims to investigate a correlation between the force required to extract a K-wire from femoral head specimens and the quality of bone. A procedure to measure K-wire pullout force was developed and tested with pig femoral head specimens. The procedure was implemented on 8 human osteoarthritic femoral head specimens and the average pullout force for each ranged from 563.32 ± 240.38 N to 1041.01 ± 346.84 N. The data exhibited significant variation within and between each specimen and no statistically significant relationships were determined between pullout force and patient age, weight, height, BMI, inorganic to organic matter ratio, and BMD. A new testing fixture was designed and manufactured to merge the clinical and research environments by enabling the physician to extract the K-wire from each bone specimen himself. The new device allows the physician to gather tactile feedback on the relative ease of extraction while load history is recorded similar to the previous procedure for data acquisition. Future work will include testing human bones with the new device to further investigate correlations for predicting bone quality.

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Transportation corridors in megaregions present a unique challenge for planners because of the high concentration of development, complex interjurisdictional issues, and history of independent development of core urban centers. The concept of resilience, as applied to megaregions, can be used to understand better the performance of these corridors. Resiliency is the ability to recover from or adjust easily to change. Resiliency performance measures can be expanded on for application to megaregions throughout the United States. When applied to transportation corridors in megaregions and represented by performance measures such as redundancy, continuity, connectivity, and travel time reliability, the concept of resiliency captures the spatial and temporal relationships between the attributes of a corridor, a network, and neighboring facilities over time at the regional and local levels. This paper focuses on the development of performance measurements for evaluating corridor resiliency as well as a plan for implementing analysis methods at the jurisdictional level. The transportation corridor between Boston, Massachusetts, and Washington, D.C., is used as a case study to represent the applicability of these measures to megaregions throughout the country.