The Use of Multi-beam Sonars to Image Bubbly Ship Wakes

During the past five years, researchers at Penn State University (PSU) have used upward-looking multi-beam (MB) sonar to image the bubbly wakes of surface ships. In 2000, a 19-beam, 5° beam width, 120° sector, 250 kHz MB sonar integrated into an autonomous vehicle was used to obtain a first-of-a-kind look at the three-dimensional variability of bubbles in a large ship wake. In 2001 we acquired a Reson 8101 MB sonar, which operates at 240 kHz and features 101-1.5º beams spanning a 150º sector. In July 2002, the Reson sonar was deployed looking upward from a 1.4 m diameter buoy moored at 29.5 m depth in 550 m of water using three anchor lines. A fiber optic cable connected the sonar to a support ship 500 m away. Images of the wake of a small research vessel provided new information about the persistence of bubble clouds in the ocean. An important goal is to use the MB sonar to estimate wake bubble distributions, as has been done with single beam sonar. Here we show that multipath interference and strong, specular reflections from the sea surface adversely affect the use of MB sonars to unambiguously estimate wake bubble distributio

Composers' Forum Student Works, February 3, 1987

This is the concert program of the Composers' Forum Student Works performance on Tuesday, February 3, 1987 at 12:30 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Lagu Laut by Arthur Levering, Scordatura for 40 open strings and 154 harmonies by Daniel Kastner, Wu-Ti by Shih-Hui Chen, and Five Preludes for solo piano by Michalis Lapidakis. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Aplikasi Persediaan Stok Barang Di CV. Surya Fajar Cemerlang

The business process in a company must have transactions, both sales and purchase transactions. Similarly, what happened in CV. Surya Fajar Cemerlang is engaged in trading building materials and electronic equipment. In processing transactions, administrative staff are responsible for recording each transaction in the book sales and purchases. However, data errors often occur due to poorly filed data. One way to overcome this problem is to use a stock inventory application. This application can process incoming goods and items that come out, so they can find out the amount of stock and can make a report on goods transactions. Making this application uses the waterfall methodology, Visual Basic .NET programming language and MySQL database. The application of processing incoming and outgoing goods is expected to help the company overcome the chaos of data archiving so that transactions are smoother and run well

Perma/Culture: Imagining Alternatives in an Age of Crisis by Molly Wallace and David Carruthers

Review of Molly Wallace and David Carruthers\u27 Perma/Culture: Imagining Alternatives in an Age of Crisis

Letter from a Connecticut Supporter to Geraldine Ferraro

Letter from a Connecticut supporter to Geraldine Ferraro. Includes data entry sheet.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_connecticut/1049/thumbnail.jp