5,153 research outputs found
Electric field measurements across the harang discontinuity
The Harang discontinuity, the area separating the positive and negative bay regions in the midnight sector of the auroral zone, is a focal point for changes in behavior of many phenomena. Through this region the electric field rotates through the west from a basically northward field in the positive bay region to a basically southward field in the negative bay region, appearing as a reversal in a single axis measurement; 32 of these reversals have been identified in the OGO-6 data from November and December, 1969. The discontinuity is dynamic in nature, moving southward and steepening its latitudinal profile as magnetic activity is increased. As activity decreases it relaxes poleward and spreads out in latitudinal width. It occurs over several hours of magnetic local time. The boundary in the electric field data is consistent with the reversal of ground magnetic disturbances from a positive to negative bay condition. The discontinuity is present in the electric field data both during substorms and during quiet times and appears to define a pattern on which other effects can occur
Electric fields in the ionosphere and magnetosphere
Electric field measuring techniques used in ionospheric and magnetospheric electrojet current studie
Challenges for the National Institute for Clinical Excellence
Rationing health care is inevitable, and NICE should inform NHS decision making. Adoption of new technologies by NHS clinicians should be informed by costs as well as effectiveness. The NHS needs better information from NICE on the equity implications of new and existing technologies. NICE appraisal should focus not only on service enhancement but also on withdrawal of existing ineffective or inefficient therapies. Giving NICE a real budget to fund its recommendations would encourage it to examine the effect of its decisions on the whole NHS
Isolated cold plasma regions: Observations and their relation to possible production mechanisms
Regions of enhanced cold plasma, isolated from the main plasmasphere along the Explorer 45 orbit on the equatorial plane, are reported using the sheath induced potentials seen by the electric field experiment. The occurrence of these regions has a strong correlation with negative enhancements of Dst, and their locations are primarily in the noon-dusk quadrant. The data support the concept that changes in large scale convection play a dominant role in the formation of these regions. Plasmatails that are predicted from enhancements of large scale convection electric fields in general define where these regions may be found. More localized processes are necessary to account for the exact configuration and structure seen in these regions and may eventually result in detachment from the main plasmasphere
The plasmapause revisited
Saturation of the dc double probe instrument on Explorer 45 was used to identify the plasmapause. A data base was developed to statistically study the average position of the plasmapause over 14.5 hours of magnetic local time under differing magnetic conditions. The afternoon-evening bulge in the L coordinate of the plasmapause versus local time was found centered between 20 and 21 hours MLT during magnetically quiet periods and shifted toward dusk as activity increased, but always post dusk. During quiet periods a bulge in the L coordinate near noon was also seen, which disappeared as activity increased. The average local time distribution plasmapause position during high magnetic activity was irregular in the afternoon region where large scale convection models predict the creation of plasmatails or detached plasma regions from increases in the solar wind induced convection. The results suggest that solar wind induced convection is partially shielded from the dayside. As the intensity of the convection is increased, it more effectively penetrates the dayside, which shifts the post dusk bulge nearer to dusk and eliminates the quiet-time bulge near noon
Impact of NICE guidance on laparoscopic surgery for inguinal hernias: analysis of interrupted time series
After the introduction of Bassini's procedure in the late 19th century, methods of repairing hernias changed little until the 1990s, when synthetic mesh and laparoscopic methods arrived. In contrast to the open mesh technique, laparoscopic surgery remains uncommon. In January 2001, the National Institute for Clinical Excellence (NICE) issued guidance that stated, "For repair of primary inguinal hernia, open [mesh] should be the preferred surgical procedure." We describe patterns of surgical repair of inguinal hernias and assess the impact of NICE's guidance
Preliminary results of measurements of sq currents and the equatorial electrojet near peru
Measurement of electric current, magnetic field, and electron density in ionosphere using Nike-Apache sounding rocket
What Are The Best Guidelines. For Dredging And Placement Of Dredged Materials?
During the~ next 25 years, more than 280 millicm cubic yards of sediment will be dredged from the Chesapeake Bay and its tributaries (Table 1). Altogether more than 800 million dollars will be spent to deepen ports and maintain shipping channels. About one-third of the maintenance dredgin~; will be done in ports and harbors where the sediment is contaminated by industrial wastes and sewage discharge. Because of long-continued disposal of dredged material, the region is losing its physical capacity to assimilate more material. Where then can these enormous loads be placed at acceptable costs? And what are the best guidelines for selecting placement sites to accomodate polluted material? What guidelines are needed for predicting the short and long-term impacts of dredging and disposal? These are! important management questions facing bay scientists, engineers, and managers who aim to protect priority resources and at the same time to accomodate shipping that requires deeper channels and efficient navigation.https://scholarworks.wm.edu/vimsbooks/1173/thumbnail.jp
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