Acoustical evaluation of the NASA Lewis 9 by 15 foot low speed wind tunnel

The test section of the NASA Lewis 9- by 15-Foot Low Speed Wind Tunnel was acoustically treated to allow the measurement of acoustic sources located within the tunnel test section under simulated free field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and to withstand tunnel airflow velocities up to 0.2 Mach. Evaluation tests with no tunnel airflow were conducted in the test section to assess the performance of the installed treatment. This performance would not be significantly affected by low speed airflow. Time delay spectrometry tests showed that interference ripples in the incident signal resulting from reflections occurring within the test section average from 1.7 dB to 3.2 dB wide over a 500 to 5150 Hz frequency range. Late reflections, from upstream and downstream of the test section, were found to be insignificant at the microphone measuring points. For acoustic sources with low directivity characteristics, decay with distance measurements in the test section showed that incident free field behavior can be measured on average with an accuracy of +/- 1.5 dB or better at source frequencies from 400 Hz to 10 kHz. The free field variations are typically much smaller with an omnidirectional source

Comparison between design and installed acoustic characteristics of NASA Lewis 9- by 15-foot low-speed wind tunnel acoustic treatment

The test section of the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel was acoustically treated to allow the measurement of sound under simulated free-field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and for withstanding the environmental conditions in the test section. In order to achieve the design requirements, a fibrous, bulk-absorber material was packed into removable panel sections. Each section was divided into two equal-depth layers packed with material to different bulk densities. The lower density was next to the facing of the treatment. The facing consisted of a perforated plate and screening material layered together. Sample tests for normal-incidence acoustic absorption were also conducted in an impedance tube to provide data to aid in the treatment design. Tests with no airflow, involving the measurement of the absorptive properties of the treatment installed in the 9- by 15-foot wind tunnel test section, combined the use of time-delay spectrometry with a previously established free-field measurement method. This new application of time-delay spectrometry enabled these free-field measurements to be made in nonanechoic conditions. The results showed that the installed acoustic treatment had absorption coefficients greater than 0.95 over the frequency range 250 Hz to 4 kHz. The measurements in the wind tunnel were in good agreement with both the analytical prediction and the impedance tube test data

The Role of New Testament Examples as Related to Biblical Authority

https://digitalcommons.acu.edu/crs_books/1607/thumbnail.jp

Comparison of Methods for Detecting Voles under Apple Trees

We conducted a study in 2 heavily infested orchards in the mid-Hudson Valley of New York to evaluate methods for detecting the presence of meadow voles (MV, Microtus pennsylvanicus) and pine voles (PV, M. pinetorum) under apple trees. We quantified several possible signs indicating the presence of voles in each of the 4 quadrants under the canopy of each tree, and then set and monitored traps until capture success in the orchard declined to zero. There was no evidence that the 4 quadrants differed with respect to any of the variables examined. The apple slice index (ASI) was the best indicator for both species. Detection improved significantly (P \u3c 0.05) when the ASI was used in conjunction with the number of runways (MV) or tunnels (PV) under the tree, although neither of the latter 2 signs was by itself a reliable indicator. The ASI and search for runways and tunnels should be conducted in at least 2 quadrants under each tree. The significance of these findings for managing voles in apple orchards is discussed

Core Ironclad

Core Ironclad is a core calculus that models the salient features of Ironclad C++, a library-augmented type-safe subset of C++. We give an overview of the language including its definition and key design points. We then prove type safety for the language and use that result to show that the pointer lifetime invariant, a key property of Ironclad C++, holds within the system

Bada Bang, Bada Boom: Dispersal of fall migrating cormorants to protect sportfish on Oneida Lake, New York

The interior population of double-crested cormorants (Phalacrocorax auritus) continues to increase. As a result, conflicts between human interests and cormorants have intensified. The impacts of nesting, roosting, and migrating cormorants include predation at aquaculture facilities, interspecific competition with rare species including common terns {Sterna hirundo), and impacts to private property. In addition, heightened public and scientific debate regarding cormorant impacts on sportfish has accelerated the need for effective, socially acceptable methods for managing local conflicts. In 1998 and 1999, USDA, APHIS, Wildlife Services; the New York State Department of Environmental Conservation; and USGS, New York Fish and Wildlife Research Cooperative collaborated on a pilot project to investigate prospective methods and strategies for reducing predation of yellow perch (Perca flavescens) and walleye (Stizostedion vitreum) by fall migrating cormorants on Oneida Lake, New York. The goal of the cooperative program was to reduce stopover time, thereby reducing predation on fish stocks by migrating cormorants. A lakewide integrated non-lethal harassment and roost management program was initiated to disperse local and migrating cormorants from September to October each year. A variety of methods were used to manage cormorants including: electronic guards, propane cannons, mylar tape, human effigies, pyrotechnics, and dispersing birds with a boat. Harassment was focused on birds loafing on the water as well as day and night roosting sites (8 day and 2 night roosts). A total of 52,840 cormorants was dispersed (in many cases individual birds were harassed multiple times) using 1,518 pyrotechnics and 649 staff hours on the lake during the 2 years of the program. Surveys documented a 61%-98% reduction of the cormorants population on Oneida Lake compared to mean counts during the same time period from 1995-1997. Estimated total annual fish consumption by cormorants was reduced by 30% in 1998. Some off-site impacts of the program were seen with increased flocks of cormorants documented on nearby lakes

Performance Score (T2D)-A New Perspective in the Assessment of Six-Minute Walking Tests in Pulmonary Rehabilitation

Because absolute changes in outcomes are difficult to interpret and the minimal clinically important difference (MCID) is not suitable to address this challenge, a novel method of classifying outcomes by relating changes to baseline values is warranted. We used the "performance score" (T2D), which reflects individual performance, enabling us to consider the functional status at the beginning of rehabilitation without dealing with the problems of mathematical coupling or regression effects, as encountered in ANCOVA. To illustrate the T2D, we retrospectively analyzed changes in the six-minute walking test (6MWT) in COPD patients undergoing outpatient pulmonary rehabilitation and compared the results with absolute differences related to a predetermined MCID. We evaluated a total of 575 COPD patients with a mean age of 61.4 ± 9.2 years. 6MWT improved significantly, with a mean change of 32.3 ± 71.2. A total of 105/311 participants who had reached the MCID were still classified as "below average" by the T2D. Conversely, 76/264 patients who had not reached the MCID were classified as "above average". This new performance measure accounts for the patient's current status and for changes over time, potentially representing a simple and user-friendly tool that can be used to quantify a patient's performance and response to rehabilitation

The Ursinus Weekly, November 10, 1952

Faculty show begins Chest drive, Nov. 15 • Pancoast, Miller debate merits of Ike and Adlai • Jones speaks to freshman class • Group production judged success • Death takes holiday in Curtain Club play • Frosh officers disclosed; Ronald Hutchinson, prexy • Seniors plan for show and dances • Workers net $40 for Campus Chest • Steward resigns • Cheerleaders to take over plans for future pep rallies • Pre-meds take tour • Former Ursinus student dies in automobile accident • Editorials: Was this fun?; Let\u27s go, Band • Noble sportsmen • Letters to the editor • Rushees sign fraternity bids • New patriotism will help Ike • Bears face Juniata in last home tilt • Bakermen lose to Haverford • Bakermen blast LaSalle in home soccer tilt, 2-0 • Temple drops Belles, 5-2 • Chess Club wins, ties • Messiah to be Dec. 11 • Lantern chooses selectionshttps://digitalcommons.ursinus.edu/weekly/1505/thumbnail.jp