Browsing by Subject "Acoustic"

Now showing 1 - 2 of 2
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    Assessing bat and bird fatality risk at wind farm sites using acoustic detectors
    (2014-08) Heist, Kevin W.
    Wind power is a promising and rapidly growing clean energy technology. Despite its environmentally friendly reputation, industrial wind energy generation can have serious impacts on wildlife. Bat and bird collision fatality rates have been alarmingly high at some wind farms. Proper siting of wind facilities may help minimize collision impacts; however, there is no reliable method for assessing risks prior to development. My goal was to develop a method for predicting fatality rates at prospective wind energy sites by monitoring acoustic activity of bats and birds. I monitored bat and bird activity using ultrasonic-acoustic detectors at 160 locations, in a variety of landscape settings to: 1) examine the utility of the detectors for monitoring bat and bird activity for pre-construction site assessment, 2) evaluate the ability of an automated bat call identification program to identify the species of recorded calls, 3) determine how pass rates relate to fatality rates, 4) examine how pass rates vary with respect to specific landscape features, 5) examine how activity differs before versus after a wind facility is built, and 6) investigate whether bat activity levels are elevated near turbines. Ground-based recording was found to be useful for studying near-ground bat activity patterns at multiple scales, but patterns of bird activity were apparent only at the coarsest geographic scale. The bat call identification program produced mixed results among species and regions. No relations between bat pass rates and fatality rates among wind farms were found. Large differences in bat and bird activity among geographic regions were found, with highest levels near Great Lakes coastlines. Also, bat and bird activity was elevated near edges of forested river corridors, relative to distances farther from the edge. Distance to water, distance to trees, and ecoregion were found to be good predictors of bat activity levels. Models of bird activity were of limited usefulness in explaining spatial variation in pass rates. Ground-based acoustic recorders were not found to be a good predictor of bat fatalities; however, they did reveal local and regional patterns that may be useful for siting wind energy facilities in low-impact areas.
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    Employees' satisfaction as influenced by acoustic and visual privacy in the open office environment
    (2014-08) Soules, Maureen Jeanette
    The purpose of this study was to examine the relationship between employees' acoustic and visual privacy issues and their perceived satisfaction in their open office work environments while in focus work mode. The study examined the Science Teaching Student Services Building at the University of Minnesota Minneapolis. The building houses instructional classrooms and administrative offices that service UMN students. The Sustainable Post-Occupancy Evaluation Survey was used to collect data on overall privacy conditions, acoustic and visual privacy conditions, and employees' perceived privacy conditions while in their primary workplace. Paired T-tests were used to analyze the relationships between privacy conditions and employees' perceptions of privacy. All hypotheses are supported indicating that the privacy variables are correlated to the employees' perception of satisfaction within the primary workplace.The findings are important because they can be used to inform business leaders, designers, educators and future research in the field of office design.