642 research outputs found
Cyclic Undrained Behavior of an Undisturbed Gravel for Aseismic Design of a Bridge Foundation
For the aseismic design of a pier foundation constructed on a lightly cemented dense gravel deposit of a 3,910m-long suspension bridge, cyclic and monotonic undrained triaxial tests were performed on undisturbed specimens with a diameter of 30cm taken from the deposit under a sea depth of about 55m. Using the results of the cyclic undrained triaxial tests together with irregular cyclic stresses evaluated for the design earthquake motion by a dynamic FEM analysis, maximum strains in the gravel deposit were obtained by the cumulative damage concept. The strain values thus estimated indicated a sufficiently high degree of seismic stability of the foundation. Further, for the same initial mean Principal stress, the strength for monotonic undrained triaxial compression of isotropically consolidated specimens was found not greater than the strength against irregular cyclic undrained loading of the specimens anisotropically consolidated as in the field. This means that the former strength can be used as an approximated value of the latter
Ground data system for Space Flyer Unit (SFU)
The Space Flyer Unit (SFU) is an unmanned, multi-purpose, retrievable and reusable space platform. The first mission of SFU (SFU-1) will be launched by NASDA's H-2 launch vehicle in early 1995 and retrieved by NASA's Space Shuttle after several months in orbit. Two Japanese ground stations, several ground stations belonging to NASA, and a ground station in Chile will be used for tracking of SFU-1. The control center of SFU-1 is the Sagamihara Operations Center (SOC) of ISAS located in Sagamihara, Japan. This paper describes the tracking and data acquisition network for SFU-1, the configuration and design policy of the SFU operations control system, and data processing schemes used for mission operations of SFU
Volumetric Assessment of the Frontal Sinus in Female Adolescents and Its Relationship with Craniofacial Morphology and Orthodontic Treatment : A Pilot Study
The present study aimed to evaluate the correlation between frontal sinus morphology and craniofacial morphology, and to investigate the effects of orthodontic treatment on the development of the frontal sinus in female adolescents (mean age: 13.9 ± 1.3 years). In total, 53 patients were recruited and underwent cephalography and computed tomography before and after orthodontic treatment. Of these patients, most had a bilaterally symmetrical fan-shaped frontal sinus without any fusion. The average size and volume of the frontal sinus before orthodontic treatment were 45.8 ± 12.3 mm in breadth, 29.8 ± 7.3 mm in height, 22.7 ± 5.1 mm in depth, and 5151.6 ± 2711.4 mm2 in volume. Sinus volume in patients with skeletal Class III malocclusion tended to be larger than that in patients with skeletal Class I and II malocclusion. Upon comparison with the pretreatment measurements, the sizes and volumes of the frontal sinus were significantly larger following orthodontic treatment, regardless of the skeletal pattern; however, since these changes were small, the increases in the size and volume of the frontal sinus may have been caused by pubertal growth and not orthodontic treatment. The clinical relevance of the frontal sinus remains controversial
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