Direction Cosines Of Principal Axes Research Articles

Bone Surface Mapping Method

Bone shape is an important factor to determine the bone's structural function. For the asymmetrically shaped and anisotropically distributed bone in vivo, a surface mapping method is proposed on the bases of its geometric transformation invariance and its uniqueness of the principal axes of inertia. Using spiral CT scanning, we can make precise measurements to bone in vivo. The coordinate transformations lead to the principal axes of inertia, with which the prime meridian and the contour can be set. Methods such as tomographic reconstruction and boundary development are employed so that the surface of bone in vivo can be mapped. Experimental results show that the surface mapping method can reflect the shape features and help study the surface changes of bone in vivo. This method can be applied to research into the surface characteristics and changes of organ, tissue or cell whenever its digitalized surface is obtained.

ESR and ENDOR of Gamma-Irradiated AgNO3

Two paramagnetic species produced in AgNO 3 by gamma-irradiation at room temperature were identified to O 3 - and NO 2 , and direction cosines of principal axes of these centers with respect to the crystal axes were determined. From these results, it was confirmed that both O 3 - and NO 2 were trapped with definite directions in the NO 3 - vacancies and their radical planes were nearly the same as those of NO 3 - ions, but the definite directions of these two radicals are different from each other. Moreover, super hyperfine interactions of O 3 - with neighboring Ag nuclei were studied by ENDOR.