Ultrasound investigation of the fetal cerebral ventricles

Peer Reviewe

Limits of the energy-momentum tensor in general relativity

A limiting diagram for the Segre classification of the energy-momentum tensor is obtained and discussed in connection with a Penrose specialization diagram for the Segre types. A generalization of the coordinate-free approach to limits of Paiva et al. to include non-vacuum space-times is made. Geroch's work on limits of space-times is also extended. The same argument also justifies part of the procedure for classification of a given spacetime using Cartan scalars.Comment: LaTeX, 21 page

General Relativistic Gravity Gradiometry

Gravity gradiometry within the framework of the general theory of relativity involves the measurement of the elements of the relativistic tidal matrix, which is theoretically obtained via the projection of the spacetime curvature tensor upon the nonrotating orthonormal tetrad frame of a geodesic observer. The behavior of the measured components of the curvature tensor under Lorentz boosts is briefly described in connection with the existence of certain special tidal directions. Relativistic gravity gradiometry in the exterior gravitational field of a rotating mass is discussed and a gravitomagnetic beat effect along an inclined spherical geodesic orbit is elucidated.Comment: 18 pages, invited contribution to appear in "Relativistic Geodesy: Foundations and Applications", D. Puetzfeld et al. (eds.), 2018; v2: matches version published in: D. Puetzfeld and C. L\"ammerzahl (eds.) "Relativistic Geodesy" (Springer, Cham, 2019), pp. 143-15

CT and ultrasound in abscess detection at specific anatomic sites: A study of 198 patients

Records of 902 patients with possible abdominal abscess were reviewed and of these 198 had abscesses on at least one occasion imaged either with ultrasound (US) or computed tomography (CT). There were 235 episodes of either one or simultaneous multiple abscesses. Sensitivities of CT and US were analyzed according to anatomic site. The nature of errors made was tabulated. CT was significantly more sensitive than US for the detection of abdominal abscess. Causes of CT and US error in abscess detection are discussed, and recommendations regarding choice of exam and means of improving performance are made.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26859/1/0000424.pd

Theory and application of the classification of second order symmetric tensors in Einstein's general theory of relativity

SIGLEAvailable from British Library Document Supply Centre- DSC:D36847/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo