A comparison of the capacity of ice hockey goaltender masks for the protection from puck impacts

Goaltenders in ice hockey are the only players that are on the ice for the entire game. Their position exposes them to impacts from collisions with other players, falls to the ice, and puck impacts. In competitive ice hockey leagues, head injuries resulting from puck impacts have been reported with some cases resulting in ending the player’s career. Considerable research has been conducted to assess the performance of hockey helmets; however, few have assessed the performance of goaltenders’ masks. The purpose of this study was to compare the capacity of four goaltenders’ masks for the protection from puck impact as measured by head acceleration and peak force. A Hybrid III headform was fitted with four different goaltender masks and impacted with a hockey puck in three locations at 25 m/s. The masks were found to vary in the level of protection they offered as the mask with the thickest liner resulted in lower forces than the thinnest mask for side impacts; however, the thinnest mask resulted in the lowest force for front impacts. Despite performance differences at specific locations, no one mask proved to be superior as peak acceleration and peak force values did not exceed the thresholds necessary for concussion.     

Making the News: Anarchist Counter-Public Relations on the World Wide Web

Traditionally, radical social movements faced a dilemma regarding media coverage: focus either on mass media, but lose control of their representation, or on alternative media, but fail to get their message to the broader public. The World Wide Web overcomes these problems, allowing movements to create their own media with mass distribution. However, it has two key weaknesses of its own: attracting audiences and mixing in- and out-group communication. In this paper, we show how the structure and content of the anarchist Web-based media work together to separate in- and out-group discourses. We then demonstrate how the anarchists attracted an audience to their Web media. The Black Bloc tactics at the Seattle protests against the World Trade Organization brought an increase in media attention, albeit negative. We examine how anarchists took advantage of the larger audience created by this bad publicity and mounted a counter-public relations campaign online. We argue that the Web alters the power relationship between mainstream and alternative media without displacing the need for mainstream coverage.     

Book reviews

Black, Edwin and Kerr, Harry P., American Issues Harcourt, Brace, and World, 750 Third Avenue, New York 17, New York. 1961, paper, $2.25.

Wrage, Ernest J. and Baskerville, Barnet, American Forum, Speeches on Historic Issues, 1788–1900. Harper and Brothers, 49 East 33rd Street, New York 16, New York. 1960.

Simmons, Harry, Executive Public Speaking Techniques. Chilton Company—Book Division, Philadelphia 39, Pennsylvania. 1959, $5.00.

Jones, E. Einston, A Guide to Effective Speech. Longmans, Green and Company, 119 West 40th Street, New York 18, New York. 1961, $3.75.

Smith, Joseph F. and Linn, James R., Skill in Reading Aloud. Harper and Brothers, 49 East 33rd Street, New York 16, New York. 1960, $5.75.     

Why Is This So Hard?: Ideologies of Endangerment,Passive Language Learning Approaches,and Ojibwe in the United States

This paper describes 3 language learning approaches common in many urban and rural Ojibwe communities, as well as the ideologies of endangerment that drive and sustain them. Drawing from collaborative language revitalization work with teachers, learners, and community leaders, we analyze some of the teaching and learning practices that lead to the common mismatch between language learner goals and expectations, on the one hand, and the outcomes of language learning, on the other. We outline how these 3 approaches to language learning relate to cultural identities and place-based notions of authenticity as well as to current findings in the field of second language acquisition. We then profile 2 speakers who have learned Ojibwe successfully as adults to illustrate how their success was possible largely because they were able to engage with the Ojibwe language in interactive ways that run counter to common language learning approaches. We suggest that for language revitalization efforts, and individual learners, to experience higher levels of success, greater attention needs to be paid to how ideologies of endangerment impact language learning approaches.     

Parallel generation of uniform fine droplets at hundreds of kilohertz in a flow-focusing module

Droplet-based microfluidic systems enable a variety of biomedical applications from point-of-care diagnostics with third world implications, to targeted therapeutics alongside medical ultrasound, to molecular screening and genetic testing. Though these systems maintain the key advantage of precise control of the size and composition of the droplet as compared to conventional methods of production, the low rates at which droplets are produced limits translation beyond the laboratory setting. As well, previous attempts to scale up shear-based microfluidic systems focused on increasing the volumetric throughput and formed large droplets, negating many practical applications of emulsions such as site-specific therapeutics. We present the operation of a parallel module with eight flow-focusing orifices in the dripping regime of droplet formation for the generation of uniform fine droplets at rates in the hundreds of kilohertz. Elevating the capillary number to access dripping, generation of monodisperse droplets of liquid perfluoropentane in the parallel module exceeded 3.69 × 10⁵ droplets per second, or 1.33 × 10⁹ droplets per hour, at a mean diameter of 9.8 μm. Our microfluidic method offers a novel means to amass uniform fine droplets in practical amounts, for instance, to satisfy clinical needs, with the potential for modification to form massive amounts of more complex droplets.     

Telecommunications and Cable

Ken Marsh's Independent Video (San Francisco: Straight Arrow Books, 1974—$7.95, paper)

Richard H. Davis and Allen E. Edwards' Television: A Therapeutic Tool for the Aged (Publication and Media Projects, Andrus Gerontology Center, University Park, Los Angeles, Calif. 90007—$2.25, paper)

Irving W. Larson (ed.) EIA Electronics Multimedia Handbook (Indianapolis: Howard W. Sams, 1975—price not known, paper)

Kendall Webster Sessions' 2nd Class FCC Encyclopedia (Blue Ridge Summit, Pa.: TAB Books, 1975—$10.95/7.95)

Mary Louise Hollowell (ed.) Cable Handbook: 1975-1976—A Guide to Cable and New Communications Technologies (Communications Press, 1346 Connecticutt Ave., N.W., Washington, D.C. 20036—$7.35, including postage, paper)

Gilbert Gillespie's Public Access Cable Television in the United States and Canada (New York: Praeger Special Studies, 1975—price not given, but likely around $12.00 or so)