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The fundamental issue driving educational reform is the redistribution of power. School principals not only use their power to influence the behavior of teachers and students, but they are also affected by using power. This paper presents findings of a study that examined the relationship between principal self-efficacy and the principal's use of various power bases. Phase 1 involved a survey of 121 elementary, middle, and secondary principals in a large metropolitan school district in a western state. In phase 2, 25 principals from the first phase completed a self-efficacy questionnaire, and a random sample of their teachers completed a survey that described their principals' use of power. Findings confirmed the research hypothesis that efficacy was positively related to expert and referent power and negatively related to legitimate, coercive, and reward power. Specifically: (1) principals with higher self-efficacy are more likely to use internally-based power when carrying out their instructional leadership role; (2) as principal experience increases, so too does the likelihood that principals will use externally-based power; and (3) the longer principals spend in one assignment, the more likely they are to use externally-based power. Five tables are included. Contains 34 references. (LMI)

This paper was presented as part of a symposium that dealt with several systematic research efforts that employed a specific methodology--the Structural Properties Questionnaire (SPQ)--as a measure of organizational structure in schools. The "subjects" in this study, 17 students in a class on organizational behavior, representing 14 different schools in 5 Utah school districts, were given instruction in structural analysis and were asked to describe their work organization in specific structural terms. The SPQ was administered to the teaching faculty in each of the subject's schools. Comparison of school descriptions provided by the class participants and by the SPQ revealed that, while there was some ability to recognize relative differences among specific factors, course participants were not consistently able to estimate structural levels. In general the class participants were poor judges of the state of structural affairs in their school organization. The results of this study would seem to suggest that administrators, left to their own means, are likely to misread the state of school organizational structure. It follows, then, that any design decisions that follow will be misguided. (Author/MLF)

Detonator output directed into both ambient air and polymethylmethacrylate (PMMA) windows is simultaneously investigated using ultra-high speed, time-resolved imaging and photonic Doppler velocimetry (PDV) measurements. In air, one-dimensional measurements of detonator cup position are made from time-resolved image sequences and compared to time-integrated velocity curves obtained from the PDV data. The results demonstrate good agreement that validates using the two methods concurrently to measure the motion of the detonator free-surface. In PMMA windows, instantaneous shock velocities are calculated from 1-D time-resolved measurements of shock position and known velocity-Hugoniot data are utilized to map the shock velocity calculations to corresponding values of mass velocity and shock pressure. Simultaneous PDV data describing the motion of the detonator cup/PMMA interface are used to determine the mass velocity and pressure at the interface, and to compare to the mass and shock pressures calculated from the imaging data. Experimental results are in good agreement with empirical detonation- and shock-interaction calculations, as well as 1-D numerical simulations. [ABSTRACT FROM AUTHOR]

A sub-microsecond, time-resolved micro-particle-image velocimetry (PIV) system is developed to investigate the output of explosive detonators. Detonator output is directed into a transparent solid that serves as a dynamic witness plate and instantaneous shock and material velocities are measured in a two-dimensional plane cutting through the shock wave as it propagates through the solid. For the case of unloaded initiators (e.g. exploding bridge wires, exploding foil initiators, etc.) the witness plate serves as a surrogate for the explosive material that would normally be detonated. The velocity-field measurements quantify the velocity of the shocked material and visualize the geometry of the shocked region. Furthermore, the time-evolution of the velocity-field can be measured at intervals as small as 10 ns using the PIV system. Current experimental results of unloaded exploding bridge wire output in polydimethylsiloxane (PDMS) witness plates demonstrate 20 MHz velocity-field sampling just 300 ns after initiation of the wire. [ABSTRACT FROM AUTHOR]