A Southern Hemispheric influence on the North Atlantic through a shallow atmospheric circulation response

Previous research has discussed the importance of meridional migrations of the North Atlantic Subtropical High (NASH) on U.S. precipitation patterns, but the mechanisms that control these meridionial migrations are virtually unknown. We have observed that, under certain conditions, a southward migration of the NASH is associated with deep tropical incursions of cold surges from the winter hemisphere over South America. When upper tropospheric winds are westerly over Amazonia, cold surges originating from extratropical South America can penetrate deep into the tropics and increase geopotential height over a broad region span from equatorial South America, across the intra-American seas, and into the subtropics of the Northern Atlantic, with anomalies exceeding +1 standard deviation to at least 18°N. The anomalous geopotential and temperature gradients associated with the South American cold surge induces a shallow tropical meridional circulation. The latter in turn increases the lower tropospheric geopotential height over the tropical to subtropical North Atlantic, leading to the equatorward expansion of the NASH. This study uncovers the importance of shallow circulations in the cross-equatorial teleconnection.Geological Science

Sonography of fetal midgut herniation: normal size criteria and correlation with crown‐rump length

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135339/1/jum1993125251.pd

Tangential sulcal echoes. Potential pitfall in the diagnosis of parenchymal lesions on cranial sonography.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135242/1/jum1987612685.pd

An Experimental Study of Centrifugal Pump Impellers

This report summarizes about three years of experimental work on centrifugal pump impellers by the hydraulic machinery group of the Hydrodynamics Laboratory. Some of the work discussed herein has already been reported as individual investigations by this project. This report embodies these earlier results together with more complete and recent investigations of centrifugal pump impellers

Effect of the Volute on Performance of a Centrifugal-Pump Impeller

An experimental study of volute influence on radial flow-impeller performance was conducted by operating a single impeller with three different sets of volute vanes. In each case, over-all performance was measured and an internal-flow study within the volute was made. The results show that at their respective design flow rates the influence of the volutes is least and the deviation of performance from the free-impeller operation is small. At off-design flow rates there are major changes in the impeller performance resulting from the presence of the volutes. Large real fluid effects, coupled with a nonuniform velocity pattern at the impeller exit, result in a flow through the volute that does not resemble a potential flow. Even so, the fluid losses through the volute are comparatively small

An Experimental Study of Centrifugal-Pump Impellers

Experimental investigations were made on four two-dimensional impellers and on a well-designed commercial three-dimensional Francis impeller. The over-all performance of each of these impellers was measured and internal-energy loss and pressure-distribution data were also obtained for several impellers. The exit angle of the two-dimensional impellers was fixed and the inlet angle was systematically varied. However, the hydraulic characteristics of these impellers were all found to differ, the source of the variation being in the various loss distributions and hence internal flow patterns in the impellers. The two-dimensional and three-dimensional impeller-loss distributions were also different. The Francis-impeller performance agreed better with potential theory than that of the two-dimensional impellers, and it is included that the different loss distributions of the two types are responsible

Prenatal ultrasound detection of congenital gingival granular cell tumor.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135345/1/jum1991103185.pd

LANDING KINEMATICS, KINETICS AND EMG IN MALE AND FEMALE ATHLETES AND NON-ATHLETES: IMPLICATIONS FOR ACL INJURY RISK

Female athletes are more likely to sustain an ACL injury than male athletes. The purpose was to investigate variables that have been identified as ACL risk factors during a landing task to determine differences among male and female athletes and non-athletes (N = 100). Variables included knee angle at contact, maximum knee angle, time (contact to max angle), VGRF, and muscle activation. Male non-athletes bent the knees significantly more after contact than male athletes. Male athletes landed with significantly more force per body weight than male non-athletes or female athletes and male non-athletes landed with significantly more force than female non-athletes. No other significant differences were observed. The authors concluded that the high rate of ACL injury among female athletes cannot be explained by the landing strategy employed in a jump