Characterization of the Mercury pulsed power x-ray source spectrum using multichannel density aerogel Cherenkov detectors.

The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO2 aerogels spanning an index of refraction (n = 1.02-1.07) corresponding to a 1.1-2.3 MeV x-ray energy threshold. The ACD/C was developed for pulsed power x-ray sources like Cygnus located at the Nevada National Site and Mercury located at the Naval Research Laboratory (NRL). Aerogels sit between the measurement capabilities of gas (>2 MeV) and solids such as fused silica (>0.3 MeV). The detector uses an aluminum converter to Compton scatter incoming x-rays and create relativistic electrons, which produce Cherenkov light in an aerogel or a fused silica medium. The ACD/C was fielded at the NRL when Mercury was tuned to produce up to 4.8 MeV endpoint bremsstrahlung. Despite a high radiation and electromagnetic interference background, the ACD/C was able to achieve high signal over noise across five aerogel densities and fused silica, including a signal to noise for a 1.1 MeV aerogel threshold. Previous experiments at Cygnus observed a signal that was comparable to the noise (1×) at the same threshold. The ACD/C observed time-resolved rise and fall times for different energy thresholds of the photon spectrum. Monte Carlo simulations of the ACD/C's aerogel response curves were folded with a simulation of Mercury's photon energy spectrum and agree within the error to the observed result.

Can alternative schools succeed where Benjamin Spock, Spiro Agnew, and B. F. Skinner have failed?

This study sought to determine whether student behavior was as great a problem in a sample of 18 California alternative high schools. As a result of on-site observations and interviews with students and teachers, the authors concluded that discipline rarely was a major concern in the alternative schools. General agreement existed among both students and teachers. Fourteen possible reasons to account for the basic finding were hypothesized. The reasons included small school size, flexible schedules, frequent informal interaction between students and teachers, and fewer rules.

Time allocation and research productivity among counseling faculty.

51 counseling and counseling psychology faculty reported their allocation of time to various work activities and the number of manuscripts accepted for publication in the previous year. There was no gender difference in productivity. Time spent on teaching and service were comparable for high and low producers, but high producers reported spending 7 more hours per week working and spent that additional time on research. High producers spent twice as much time on research while producing seven times as many publications, suggesting a more effective use of research time. High producers' suggestions for efficient management of time are presented.

Why don't girls misbehave more than boys in school?

Reviewing research on sex differences in school misbehavior and delinquency, the author speculates on six possible reasons why girls appear to misbehave less than boys despite the fact that girls are characterized by more personal problems during adolescence. Several reasons including the possibility that girls' misbehavior is inaccurately reported are rejected as insufficient to account for the discrepancy between boys' and girls' misbehavior. On the basis of existing evidence, the author concludes that a combination of personal characteristics (i.e., high need for affiliation and low aggressiveness) and external pressures (parental and teacher expectations and attitudes) function to inhibit misbehavior in girls. Some indications that the situation is changing are reported.