High-speed texture measurement of pavements.
This study was conducted to validate high-speed texture measuring equipment for use in highway applications. The evaluation included two high-speed systems and a new static referencing device. Tests were conducted on 22 runway and taxiway test sections from the National Aeronautics and Space Administration's Wallops Flight Facility and 7 surfaces from Virginia's Smart Road. Texture estimates recorded with the high-speed (dynamic) equipment correlated extremely well with estimates made with static referencing methods. The system developed by International Cybernetics Corporation was very functional for most conventional highway surfaces. However, a better correlation may be achieved with the referencing methods by using a system (such as the MGPS surface system developed by the Federal Highway Administration) that produces the American Society for Testing and Materials' standard mean profile depth. Finally, an analysis conducted using the CTMeter (circular track meter, a laser-based but static system) demonstrated an important advantage of combining indices produced from high-definition surface profiles. By comparing the mean profile depth with the root mean square data for a particular surface, it is possible to characterize more fully the shapes that contribute to a pavement's macrotexture.
EVALUATION OF PAVEMENT FRICTION CHARACTERISTICS
This synthesis report will be of interest to pavement design, construction, management, and research engineers, highway safety officials, and others concerned with pavement friction characteristics. It describes the current state of the practice for evaluating pavement friction characteristics. Information for the synthesis was collected by surveying U.S., Canadian, and international transportation agencies, and by conducting a literature search to gather additional information. This report of the Transportation Research Board provides information on wet pavement friction characteristics of new and restored pavements. It includes information on the methods for measuring and reporting friction and texture, causes for friction changes over time, and on the related aspects of aggregate and mix design to provide adequate friction. A limited amount of information on the impact of economic and legal considerations is also included. In addition, considerations of noise and ride quality are discussed when compromise may be required. The International Friction Index (IFI) is included with information on the measuring and reporting of friction and texture.
Professional tensions in client-centered practice: using institutional ethnography to generate understanding and transformation.
For almost 20 years, occupational therapists have advocated client-centered practice. Yet client-centered practice is fraught with tensions that arise outside the practice of individual occupational therapists. This paper is guided by two questions: What produces professional tensions in client-centered practice? and What understanding and change might be generated using institutional ethnography? The sociological theory and method of institutional ethnography are described using data from an ongoing investigation of mental health services as a social institution. Illustrated are the research aim, research questions, and institutional analysis that distinguish institutional ethnography from conventional ethnography. Two professional tensions are associated with attempts to fulfill client-centered practice in mental health. One is that of working at cross-purposes with the prevailing hierarchical structure; the other tension is that of being celebrated yet subordinated in the medical and management hierarchies of health services. Although client-centered practice is difficult to do, the authors recommend institutional ethnography as a research approach to generate understanding and transformation of the context and practice of occupational therapy.