Stability of E' centers induced by 4.7eV laser radiation in SiO2

The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed laser irradiation in dry fused silica was investigated by in situ optical absorption spectroscopy. The stability of the defects, conditioned by reaction with mobile hydrogen of radiolytic origin, is discussed and compared to results of similar experiments performed on wet fused silica. A portion of E' and hydrogen are most likely generated by laser-induced breaking of Si-H precursors, while an additional fraction of the paramagnetic centers arise from another formation mechanism. Both typologies of E' participate to the reaction with H_2 leading to the post-irradiation decay of the defects. This annealing process is slowed down on decreasing temperature and is frozen at T=200K, consistently with the diffusion properties of H_2 in silica.Comment: 12 pages, 3 figures, in press on J. Non cryst. solids (2007

MLA-L at Twenty

MLA-L, the electronic-mail distribution list for music librarians, is now twenty years old. Before the establishment of the list in 1989, professional communication among music librarians was paper based and slow. The growth of computer networks in the early 1980s led to the development of applications to promote group communication, including LISTSERV, an e-mail distribution application released in 1986. With the help of Mary Papakhian, a member of the information technology staff at Indiana University, Ralph Papakhian established MLA-L as the first distribution list on the university\u27s LISTSERV server. Growth of the list was rapid: by the end of 1995, there were over 1,000 subscribers, and since then the number has slowly increased to over 1,100. The topics of discussion on MLA-L cover all aspects of the profession, and the archives of messages posted to the list provide a rich resource for the study of the history of music librarianship

Digital Audio in the Library

An incomplete draft of a book intended to serve as a guide and reference for librarians who are responsible for implementing digital audio services in their libraries. The book is divided into two parts. Part 1, Digital Audio Technology, covers the fundamentals of recorded sound and digital audio, including a description of digital audio formats, how digital audio is delivered to the listener, and how digital audio is created. Part 2, Digital Audio in the Library, covers digitizing local collections, providing streaming audio reserves, and using digital audio to preserve analog recordings

Italy

Suggested Resources for the Penn Alumni Travel excursion in Italy. See the Library Guide for this bibliography here

Geology of the Ripogenus Lake Area, Maine

Guidebook for field trips in the Mount Katahdin Region, Maine: 58th annual meeting September 29, 30, October 1, 1966: Trip B

Periodical Use in a University Music Library: A Citation Study of Theses and Dissertations Submitted to the Indiana University School of Music from 1975-1980

In an effort to measure in-house use of music periodicals, a citation study based on bibliographies in theses and dissertations was conducted at the Indiana University Music Library. A total of 256 titles were cited, but only 30% were cited more than once. While the periodical literature cited by musicologists has a low rate of obsolescence, the periodicals cited by theorists and educators becomes obsolete at a rapid rate, making the rate of obsolescence for the field as a whole, fairly high, unlike other subject areas in the humanities

Geology of the Stratton Quadrangle, Maine

Guidebook for fifty-second annual meeting of the New England Intercollegiate Geological Conference field trips in West-Central Maine, October 8-9, 1960: Trip

Distant Music: Delivering Audio over the Internet

Advances in audio technology in the 1980s and 1990s made it possible for librarians to create digital copies of sound recordings and to provide off-site access to them through streaming-media servers. Because streaming technology could accommodate heavy use at odd hours from any location, librarians quickly applied the new digital audio technologies to curricular listening assignments, providing a parallel to the print e-reserves projects developed by academic libraries during the 1990s. The results of a survey of thirty-nine digital audio reserves projects offers information on streaming formats, streaming rates, access control, user interfaces, staffing, equipment, and costs

Vladimir Jurowski Studies Eugene Ormandy’s Changes to a Rachmaninoff Symphony

Report on the use of the Kislak Center\u27s Eugene Ormandy Collection of Scores by composer Vladimir Jurowski