Movable electrode-type ER actuators (proposal of linear-type and rotary-type METERA)
By employing ER fluids as working fluids in fluid power systems, a direct interface can be realized between electric signals and fluid power without the need for mechanical moving parts like spools in control valves. In the paper, first, hydraulic actuators with ER fluids and with movable electrodes (METERA: movable electrode-type ER actuator) are proposed, which are classified into a linear type (L-METERA) and a rotary-type (R-METERA). Secondly, a design method of L-METERA is described and a small sized L-METERA is fabricated, whose size is 40 mm/spl times/18 mm/spl times/16 mm. Thirdly, a design method of R-METERA is described and a small sized R-METERA is fabricated, whose size is /spl phi/67 mm/spl times/53 mm. Principles of METERA are confirmed with the fabricated METERA.
Electrorheological Properties of Suspensions of Inorganic Shell/Organic Core Composite Particles
Abstract Composite particles consisting of a polymer core and inorganic shell are formed by suspension polymerization. The electrorheological (ER) behavior of the suspensions is studied in relation to surface conditions. When the composite particles are subjected to jet-stream agitation, the ER effects are strikingly enhanced. Although the inorganic shell on the polymer particles is responsible for the ER effect, the impurities which were derived from the polymerization reaction must be removed from the surfaces. The suspensions are nonconducting, even though the polymer cores are coated with conducting particles. In composite particles, the thin layer of polymer prevents direct contact of inorganic particles which are arranged in layers on the polymer core. Since the density of composite particles is comparable to that of oil, the suspensions have long-term stability against sedimentation.
Key Considerations for an Economic and Legal Framework Facilitating Medical Travel
Medical travel has the capacity to counter increasing costs of health care by creating new markets and increased revenue for health services, potentially benefiting local populations, economies, and health-care systems. This paper is part of a broad, comprehensive project aimed at developing a global health access policy (GHAP). It presents key issues to consider in terms of ensuring economic viability, sustainability, and limiting risk to the many stakeholders involved in the rapidly expanding industry of medical travel. The noted economic and legal barriers to medical travel are based on a synthesis of themes found in an extensive review of the available literature. Economic considerations, when setting up a GHAP, include a dynamic approach to pricing that is fair to the local population. Legal considerations include the implementation of international quality standards and the protection of the rights of those traveling as well as those of local populations in recipient countries. By taking into account these opportunities, the GHAP will more adequately address existing gaps in the economic and legal regulation of medical travel.