The Rapid Geodetic Survey System (RGSS)

The Rapid Geodetic Survey System (RGSS) is a system employing a high-accuracy gimbaled inertial platform. It provides a cost-effective capability for accurate direct measurement of the change in position, elevation, gravity intensity and deflection of the vertical from an initial point. The RGSS is an adaptation of the production version of the U.S. Army Position and Azimuth Determining System (PADS). Several hardware and software enhancements to improve the performance of the system, primarily for gravity vector survey, have occurred over the last few years. The basic principles for the control of error in the survey measurements due to noise and systematic error are discussed below. Actual acceptance test results for the RGSS which indicate an inherent capability of the system to measure change in the deflection of the vertical to a few-tenths of an arcsecond over survey periods of one to two hours using careful survey techniques are also presented. Finally a simple method to extend the capability of the system for longer duration surveys is indicated

A Model Approach to the Electrochemical Cell: An Inquiry Activity

In an attempt to address some student misconceptions in electrochemistry, this guided-inquiry laboratory was devised to give students an opportunity to use a manipulative that simulates the particulatelevel activity within an electrochemical cell, in addition to using an actual electrochemical cell. Students are led through a review of expected prior knowledge relating to oxidation and reduction half-reactions. Then, the students examine the macroscopic level by constructing and using an electrochemical cell. Finally, students use the manipulative and make connections between the two levels through class discussion. The misconceptions involve the movement of electrons and ions through solution and the salt bridge, the resulting charges of the half-cells, and the charge sign given to the anode and cathode on electrochemical and electrolytic cells. Additionally, the activity covers oxidation and reduction reactions in electrochemical cells and provides practice drawing and labeling parts of an electrochemical cell. Results, pre- and post-testing and student comments, indicate that this laboratory facilitates students’ understanding of electrochemical cells

American Internal Medicine in the 21(st) Century: Can an Oslerian Generalism Survive?

American internal medicine suffers a confusion of identity as we enter the 21(st) century. The subspecialties prosper, although unevenly, and retain varying degrees of connection to their internal medicine roots. General internal medicine, identified with primary care since the 1970s, retains an affinity for its traditional consultant-generalist ideal even as primary care further displaces that ideal. We discuss the origins and importance of the consultant-generalist ideal of internal medicine as exemplified by Osler, and its continued appeal in spite of the predominant role played by clinical science and accompanying subspecialism in determining the academic leadership of American internal medicine since the 1920s. Organizing departmental clinical work along subspecialty lines diminished the importance of the consultant-generalist ideal in academic departments of medicine after 1950. General internists, when they joined the divisions of general internal medicine that appeared in departments of medicine in the 1970s, could sometimes emulate Osler in practicing a general medicine of complexity, but often found themselves in a more limited role doing primary care. As we enter the 21(st) century, managed care threatens what remains of the Oslerian ideal, both in departments of medicine and in clinical practice. Twenty-first century American internists will have to adjust their conditions of work should they continue to aspire to practice Oslerian internal medicine