On symmetric commutator subgroups, braids, links and homotopy groups

In this paper, we investigate some applications of commutator subgroups to homotopy groups and geometric groups. In particular, we show that the intersection subgroups of some canonical subgroups in certain link groups modulo their symmetric commutator subgroups are isomorphic to the (higher) homotopy groups. This gives a connection between links and homotopy groups. Similar results hold for braid and surface groups.Comment: 24 pages, 1 figur

Considerations of some critical ejector problems

Some aspects of ejector design and application, including, three dimensional effects and cross flow effects are presented

Catalogers explore a new frontier: establishing a NEASC evidence center

This article describes how cataloging staff at the Roger Williams University Library established, managed, and planned to preserve an online NEASC Evidence Center for the University’s reaccreditation process. It highlights use of MARC and AACR2rev for effective organization of the Center’s records and the continuing importance of professional cataloging skills

The Future of Institutional Repositories at Small Academic Institutions: Analysis and Insights

Institutional repositories (IRs) established at universities and academic libraries over a decade ago, large and small, have encountered challenges along the way in keeping faith with their original objective: to collect, preserve, and disseminate the intellectual output of an institution in digital form. While all institutional repositories have experienced the same obstacles relating to a lack of faculty participation, those at small universities face unique challenges. This article examines causes of low faculty contribution to IR content growth, particularly at small academic institutions. It also offers a first-hand account of building and developing an institutional repository at a small university. The article concludes by suggesting how institutional repositories at small academic institutions can thrive by focusing on classroom teaching and student experiential learning, strategic priorities of their parent institutions

International Conference on Dublin Core and Metadata Application 2004

The International Conference on Dublin Core and Metadata Applications took place on October 11-14, 2004 in Shanghai, China. It was the fourth in a series of expanded Dublin Core conferences that included a conference, tutorials and workshops. Prior to the first in this series of conferences held in Tokyo in 2001, eight Dublin Core workshop series had been held in various North American and European countries starting in 1995. These workshops and conferences have provided a forum where researchers and practitioners can exchange new ideas and demonstrate the development of metadata standards and applications from practical aspects

Magnetization reversal in AFC media

In this paper, we report on a study of magnetization reversal processes in antiferromagnetically coupled media. We describe the reversal in terms of the reversible and irreversible susceptibility that has been measured for the CoCrPtB system of fixed-recording layer thickness and variable-stabilization layer thickness. We rind that very thin stabilization layers do not couple strongly to the recording layer, and that for Mrt greater than 0.11 memu/cm(2), some of the change in magnetization becomes irreversible

Design study of TDRS antenna gimbal system for LANDSAT-D

The conceptual design studies of a two axis antenna drive assembly for the TDRSS link communications subsystem for LANDSAT D are presented. The recommended antenna drive assembly is a simple and reliable design substantially similar to the antenna and solar array drives developed and space qualified for programs such as DSCS 2 and FltSatCom. The gimbal design tradeoff is presented, along with drive electronics

Jet-diffuser Ejector - Attached Nozzle Design

Attached primary nozzles were developed to replace the detached nozzles of jet-diffuser ejectors. Slotted primary nozzles located at the inlet lip and injecting fluid normal to the thrust axis, and rotating the fluid into the thrust direction using the Coanda Effect were investigated. Experiments indicated excessive skin friction or momentum cancellation due to impingement of opposing jets resulted in performance degradation. This indicated a desirability for location and orientation of the injection point at positions removed from the immediate vicinity of the inlet surface, and at an acute angle with respect to the thrust axis. Various nozzle designs were tested over a range of positions and orientations. The problems of aircraft integration of the ejector, and internal and external nozzle losses were also considered and a geometry for the attached nozzles was selected. The effect of leaks, protrusions, and asymmetries in the ejector surfaces was examined. The results indicated a relative insensitivity to all surface irregularities, except for large protrusions at the throat of the ejector