Factors affecting job satsifaction and turnover among public school superintendents in Iowa and Minnesota

The purpose of this study was to examine the factors of job satisfaction among school superintendents and the relationships between satisfaction and turnover. One hundred eighty-one superintendents in Iowa and Minnesota who had spent less than three years or more than fifteen years as chief administrator in their current district responded to a three-page questionnaire. The survey instrument consisted of personal-experiential variables, task variables, and the Job Descriptive Index and was designed to measure job satisfaction and rate of turnover;Group t tests were used to establish significant differences between the two groups of superintendents, and the findings were compared to Chand\u27s 1982 study. Pearson r correlations established relationships between level of overall satisfaction and all other variables in the instrument. Multiple regression correlation determined the capacity of job satisfaction in predicting turnover;Analysis of the data results in these findings: (1) Length of service made significant contributions to job satisfaction in the areas of community attitude, work hours per week, paper work, safety, co-workers, and pay. (2) Length of service does not affect the level of overall job satisfaction among superintendents. (3) Three-fourths of the superintendents would choose the superintendency as a career again. (4) Superintendents in Iowa and Minnesota are more highly satisfied than those involved in the national study. (5) Job satisfaction does not predict turnover

Electron Optics

Contains research objectives and summary of research on one research project.Joint Services Electronics Program (Contract DAAB07-75-C-1346

Long term constraints on the global marine carbonate system

As a result of the interaction between biological cycles and the abyssal circulation, the modem North Pacific Ocean bas a lower degree of calcite saturation (Ω) and a shallower carbonate compensation depth (and lysocline) than does the North Atlantic…

Searching for Dark Clumps with Gravitational-Wave Detectors

Dark compact objects ("clumps") transiting the Solar System exert accelerations on the test masses (TM) in a gravitational-wave (GW) detector. We reexamine the detectability of these clump transits in a variety of current and future GW detectors, operating over a broad range of frequencies. TM accelerations induced by clump transits through the inner Solar System have frequency content around $f \sim \mu$Hz. Some of us [arXiv:2112.11431] recently proposed a GW detection concept with $\mu$Hz sensitivity, based on asteroid-to-asteroid ranging. From the detailed sensitivity projection for this concept, we find both analytically and in simulation that purely gravitational clump-matter interactions would yield one detectable transit every $\sim 20$ yrs, if clumps with mass $m_{\text{cl}} \sim 10^{14} \text{kg}$ saturate the dark-matter (DM) density. Other (proposed) GW detectors using local TMs and operating in higher frequency bands are sensitive to smaller clump masses and have smaller rates of discoverable signals. We also consider the case of clumps endowed with an additional attractive long-range clump-matter fifth force significantly stronger than gravity (but evading known fifth-force constraints). For the $\mu$Hz detector concept, we use simulations to show that, for example, a clump-matter fifth-force $\sim 10^3$ times stronger than gravity with a range of $\sim\text{AU}$ would boost the rate of detectable transits to a few per year for clumps in the mass range $10^{11} \text{kg} \lesssim m_{\text{cl}} \lesssim 10^{14} \text{kg}$, even if they are a $\sim 1$% sub-component of the DM. The ability of $\mu$Hz GW detectors to probe asteroid-mass-scale dark objects that may otherwise be undetectable bolsters the science case for their development.Comment: 22 pages, 4 figures. Published versio

Electron Optics

Contains reports on two research projects.Joint Services Electronics Program (Contract DAAB07-75-C-1346

Infrared Surface Brightness Fluctuations of the Coma Elliptical NGC 4874 and the Value of the Hubble Constant

We have used the Keck I Telescope to measure K-band surface brightness fluctuations (SBFs) of NGC 4874, the dominant elliptical galaxy in the Coma cluster. We use deep HST WFPC2 optical imaging to account for the contamination due to faint globular clusters and improved analysis techniques to derive measurements of the SBF apparent magnitude. Using a new SBF calibration which accounts for the dependence of K-band SBFs on the integrated color of the stellar population, we measure a distance modulus of 34.99+/-0.21 mag (100+/-10 Mpc) for the Coma cluster. The resulting value of the Hubble constant is 71+/-8 km/s/Mpc, not including any systematic error in the HST Cepheid distance scale.Comment: ApJ Letters, in press. Uses emulateapj5.st