Variable-Tension-Cord Suspension/Vibration-Isolation System

A system for mechanical suspension and vibration isolation of a machine or instrument is based on the use of Kevlar (or equivalent aromatic polyamide) cord held in variable tension between the machine or instrument and a surrounding frame. The basic concept of such a tensioned-cord suspension system (including one in which the cords are made of aromatic polyamide fibers) is not new by itself; what is new here is the additional provision for adjusting the tension during operation to optimize vibration- isolation properties. In the original application for which this system was conceived, the objective is to suspend a reciprocating cryocooler aboard a space shuttle and to prevent both (1) transmission of launch vibrations to the cryocooler and (2) transmission of vibrations from the cryocooler to samples in a chamber cooled by the cryocooler. The basic mechanical principle of this system can also be expected to be applicable to a variety of other systems in which there are requirements for cord suspension and vibration isolation. The reciprocating cryocooler of the original application is a generally axisymmetric object, and the surrounding frame is a generally axisymmetric object with windows (see figure). Two cords are threaded into a spoke-like pattern between attachment rings on the cryocooler, holes in the cage, and cord-tension- adjusting assemblies. Initially, the cord tensions are adjusted to at least the level necessary to suspend the cryocooler against gravitation. Accelerometers for measuring vibrations are mounted (1) on the cold tip of the cryocooler and (2) adjacent to the cage, on a structure that supports the cage. During operation, a technician observes the accelerometer outputs on an oscilloscope while manually adjusting the cord tensions in an effort to minimize the amount of vibration transmitted to and/or from the cryocooler. A contemplated future version of the system would include a microprocessor-based control subsystem that would include cord-tension actuators. This control subsystem would continually adjust the cord tension in response to accelerometer feedback to optimize vibration-isolation properties as required for various operating conditions. The control system could also adjust cord tensions (including setting the two cords to different tensions) to suppress resonances. Other future enhancements could include optimizing the cord material, thickness, and braid; optimizing the spoke patterns; and adding longitudinal cords for applications in which longitudinal stiffness and vibration suppression are required

Superior Karst Management Through Superior Data Management: The Karst Information Portal

Effective stewardship of caves and karst areas requires access to and efficient analysis of a diverse range of information. Vital data are scattered throughout specialty mainstream journals, which even for a single project could include fields such as ecology, hydrogeology, contaminant transport, toxicology, engineering geology and law. Additionally, volumes of crucial information often lie in diffi­cult-to-find gray literature. Management recommendations and decisions should be based on assessments of state-of-the-art information, but fall short when im­portant patterns and relationships are overlooked. The Karst Information Portal (KIP) offers a solution to these problems. Con­ceived in 2005 and launched in June 2007, KIP grew as a partnership among the International Union of Speleology, National Cave and Karst Research Institute, University of New Mexico, and University of South Florida. Key features com­plete or in development include: federated searches of Web sites for more efficient and reliable location of key research papers and information; a searchable database of multidisciplinary karst information; a library of on-line karst papers, reports and theses; and a collaborative international on-line workspace to post and evaluate im­ages, maps, databases, and other published and unpublished information. Like other virtual research portals, KIP will continue to grow as existing and future partners contribute information by plugging Web sites and databases into the network. KIP will not duplicate existing databases but will more efficiently access and process them with superior tools. Additional partners can help fulfill KIP’s potential in revolutionizing cave and karst stewardship through advanced and collaborative integration of data and ideas

New modes of governance and the commodification of criminological knowledge

This article explores the influence of new modes of governance on the production of criminological knowledge. In doing so, it examines the rise of discourses on risk and critiques the ways in which academic environments are changing under new managerialist philosophies. The article further explores the increasing 'commodification of criminological knowledge' and analyses its effect on contemporary criminological scholarship. Finally, this article examines the contours of critical criminological scholarship and advocates for a criminology of resistance