Cominco fertilizer trials - 1972

Non-Peer Reviewe

Managing Change: The Role of Documentation and Condition Survey at Mesa Verde National Park

The approximately 600 cliff dwellings in Mesa Verde National Park in Colorado represent the apex of architectural sophistication of the Northern San Juan Ancestral Puebloan culture. The cliff dwellings, the final product of 600 years of cultural development on the Mesa Verde, were built between A.D. 1200 and 1300, and were abandoned shortly thereafter. The spectacular setting and the well-preserved state of these masonry structures and their surface finishes resulted in Mesa Verde\u27s being the first nomination by the U.S. government to the World Cultural Heritage Sites List. Moreover, descendants of these ancient peoples, the Pueblo Indians of Arizona and New Mexico, continue to venerate these sites, representing a cultural continuity unique for North America. Excavation and preservation have been continuous since Mesa Verde became one of the first national parks in 1906. The structures interpreted to the public have been preserved over the years with a minimum of repair and replacement, resulting in a cultural resource of great integrity and authenticity. A phased conservation program to develop coordinated methods for the survey, analysis, stabilization, and interpretation of the masonry and prehistoric surface finishes in the alcovate (cliff-dwelling) sites of Mesa Verde National Park has been in progress since 1994 by the Architectural Conservation Laboratory of the University of Pennsylvania. The program has included a comprehensive method of study, including archival research, technical analysis, and characterization of the architectural materials; detailed field and digital recording of existing conditions, including environmental monitoring; and the design, testing, and execution of a treatment and protection program specifically focused on the in situ stabilization of plain and painted architectural surface finishes. Though case-study oriented, this article addresses in detail the theoretical and technical aspects of condition survey and recording as an important vehicle for material and site diagnostics, which must precede remedial and preventive interventions. Detailed information is provided on the use of current digital technology for condition survey

Rocket studies of X-rays from the nonflaring sun Final report

Rocket measurements on high energy tail of quiescent solar X ray spectru

Edge Contours

The accuracy with which a computer vision system is able to identify objects in an image is heavily dependent upon the accuracy of the low level processes that identify which points lie on the edges of an object. In order to remove noise and fine texture from an image, it is usually smoothed before edge detection is performed. This smoothing causes edges to be displaced from their actual location in the image. Knowledge about the changes that occur with different degrees of smoothing (scales) and the physical conditions that cause these changes is essential to proper interpretation of the results obtained. In this work the amount of delocalization and the magnitude of the response to the Normalized Gradient of Gaussian operator are analyzed as a function of σ, the standard deviation of the Gaussian. As a result of this analysis it was determined that edge points could be characterized as to slope, contrast, and proximity to other edges. The analysis is also used to define the size that the neighborhood of an edge point must be in order to assure its containing the delocalized edge point at another scale when σ is known. Given this theoretical background, an algorithm was developed to obtain sequential lists of edge points. This used multiple scales in order to achieve the superior localization and detection of weak edges possible with smaller scales combined with the noise suppression of the larger scales. The edge contours obtained with this method are significantly better than those achieved with a single scale. A second algorithm was developed to allow sets of edge contour points to be represented as active contours so that interaction with a higher level process is possible. This higher level process could do such things as determine where corners or discontinuities could appear. The algorithm developed here allows hard constraints and represents a significant improvement in speed over previous algorithms allowing hard constraints, being linear rather than cubic

Design investigations on some welded mild steel plate girders

The thesis gives details of a series of design investigations carried out on mild steel, welded, plate girders, having a constant I section and supported laterally and torsionally only at the ends of the span. The main aim is to establish a General Method for expediting the design calculations for obtaining the optimum cross sectional dimensions of such a girder, essentially in accordance with the regulations as laid down in the British Standard Specification (B.S.449, while observing some rules for efficient or economical design. Here Minimum Weight Design has been chosen as the criterion of efficiency, though the methods devised can readily be extended or adapted to deal with other criteria. The moment of resistance, as reduced by lateral buckling, is deemed to be the significant factor in each design, though the various other effects are considered as well. A review of the problem is given, and an empirical investigation is then carried out to obtain the sectional dimensions of girders at Minimum Weight, spanning 100 feet, and resisting various moments. This work is then extended to a wider application by means of a theoretical analysis, and a General Method is obtained. Suggestions are made as to how this Method may be applied, viz: by the construction of charts and tables or by the writing of an all embracing computer programme to give automatic design. Various additional effects are described and finally an outline is given as to how this work can be extended to deal with more complicated practical girders