Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Literature reports have indicated that application of sonic pressure waves enhances the rate of impregnation of preservatives in wood. However, these studies have been limited and inconclusive. The technique or process is not in commercial use. In this study a laboratory scale treating cylinder connected to a mechanical sonic wave generator was used to measure the rate of impregnation of water in ponderosa pine at pressures of 0.28, 0.55 and 0.69 MPa and Douglas-fir at pressures of 0.55 and 0.69 MPa at a frequency of 30 Hz. Results were compared with those obtained at the same conditions of static hydraulic pressure. Statistical analysis showed that sonic treatments were at least as effective as, but not consistently superior to, hydraulic pressure treatments in the case of ponderosa pine. Statistical analysis of the results from Douglas-fir treatment showed that sonic treatment was superior than hydraulic treatment. / Graduation date: 1995

Typescript (photocopy). / Digitized by Kansas Correctional Industries

This research tested the effect of unique combinations of interface coding and presentation techniques for the redesign of the AN/SLQ-32(V) Display Control Console (DCC). The DCC provides Navy operators with bearing and threat information for radar emitters. The task of emitter identification was used to test potential redesigns. There is no research to substantiate the current or possible redesign solutions. Thus, Experiment 1 tested potential design modifications for the DCC. The factorial combination of the following comparisons yielded eight possible design solutions: color versus monochrome coding, polar (bearing only) versus range (bearing and range) presentation, and geometric symbols versus icons. Each design was tested in three conditions of emitter density: low, medium, and high. Researchers have evaluated color and symbology with consideration to emitter display systems, but without considering how range information and emitter density effect performance. Results indicate that range information improves performance by 60%. The addition of color and the new icons also significantly improves performance (17% and 15%, respectively) as compared to the current DCC configuration (Polar, Geometric, and Monochrome). Performance was measured by time to complete a task, errors, and subjective workload. Experiment 2 considered redesign solutions not restricted to the existing hardware or software. Although discussed frequently in the interface literature, performance differences between direct-manipulation and command-key interfaces have not been validated. In this study, two interfaces were constructed to take advantage of direct manipulation and command-key interaction (DMI and CKI, respectively) styles while adding a computer-aided emitter library management system, an on-screen oscilloscope, a polygon display of emitter parameters, range information, icons, increased usage of color, and other design changes. Results indicate no differences between the CKI and DMI for the time required to perform the task or for subjective workload. Although both interfaces were designed to take advantage of their respective features, operators did not perform faster with the CKI than with the DMI. However, operators did have significantly fewer errors with the DMI than with the CKI. When compared to the existing DCC and the Range/Color/Iconic design, operators using the CKI and DMI: (1) processed twice as many emitters, (2) reduced one type of error by 50% (CKI) or 67% (DMI), (3) reduced a second type of error to zero, (4) decreased subjective workload by over 50%, and (5) maintained a higher level of performance regardless of emitter density. / Ph. D.