Abstract: An improved tooth profile for a roller chain sprocket enables noise reduction from impact and polygonal action during the meshing process. The profile of the engaging flank consists of three portions which are the seating, impact and distal portions all three of which are arcs with well-defined radii and arc centers. The profile of the disengaging flank is determined in accordance to a modified form of the JIS standard in which the sprocket pitch is smaller than the roller chain pitch. The impact point is located at the tangent point, thus permitting a gradual change of the roller velocity, thereby lessening the impact level and the effects of polygonal action.

Abstract: A valveless micropump includes a hollow pump chamber having a driving element coupled thereto, an inlet channel coupled to the hollow pump chamber, and an outlet channel coupled to the hollow pump chamber. The inlet channel, the hollow pump chamber, and the outlet channel define a fluid flow path through the inlet channel, the hollow pump chamber, and the outlet channel. At least one direction-sensitive element disposed in the flow path within one of the inlet and outlet channels and comprising a direction-sensitive element, is installed at an angle which produces a drag ratio greater than unity on fluid in the flow path. The driving element may comprise an electrostatic/piezoelectric member. Various embodiments of the valveless pump include one or more of the airfoil elements mounted in one, the other or both of the inlet and outlet channels, including embodiments in which one or more cascades of the airfoil elements are mounted in the inlet channel and the outlet channel.

Abstract: First and second electrically conductive rods are provided inside a shielded electromagnetic test chamber. These rods are energized to radiate electromagnetic energy inside the chamber. The rods are mounted inside the chamber at right angles to one another, the first rod is movable through the interior volume in a first direction perpendicular to its long axis, and the second rod is movable through the chamber in a second direction perpendicular both to its own long axis and to the first rod's direction of motion. Energy is supplied to the two rods in a way that enhances the uniformity of the electromagnetic field applied to a working volume inside the chamber as the two rods move through the chamber.

Abstract: An electrostatically operated, normally closed micromachined flow-through microvalve device comprises a stationary valve plate layer and a movable valve plate layer, the latter including an electrode plate such that it is deflectable by electrostatic forces under an applied voltage, and having a plurality of movable valve elements, each valve element moving with a degree of independence from the remaining valve elements. Application of a voltage results in deflection of the movable valve elements, the order of deflection depending on the relative magnitude of the electrostatic force experienced by the respective associated portion of the movable valve plate layer. This can be prescribed by the geometry of the device, and a preferred example provides a different separation between different portions of the movable valve plate layer and a further electrode plate in a device base plate layer.

Abstract: Lead-free solder alloys based on a Sn—Ag—Mg system are disclosed. The alloy compositions have a melting temperature close to 183° C. and a similar surface tension to that of Sn—Pb solder, and can thus be a readily substituted for conventional Sn—Pb solders. P may be added to the alloy compositions to reduce its tendency of oxidation.

Abstract: The invention can be used in a micropump for dispensing a pharmaceutical liquid, in an ink jet printer or similar devices, or in other applications for controlled pumping of a liquid through an opening in a barrier wall. A pair of electrodes is in electrical contact with a fluid confined behind a containing wall. Each electrode is connected to a source of different electrical potential. When current is conducted through the fluid between the electrodes, resistance heating in the fluid causes local boiling and thus the formation and expansion of a bubble within the fluid. The electrodes are disposed on either side of an opening in the wall, so that the bubble is formed on one side of the wall in close proximity to the opening. Fluid behavior is such that a fluid jet is formed when the bubble collapses in close proximity to the wall. This jet impacts the bubble in a direction toward the wall.

Abstract: The invention can be used in a micropump for dispensing a pharmaceutical liquid, in an ink jet printer or similar devices, or in other applications for controlled pumping of a liquid through an opening in a barrier wall. A pair of electrodes is in electrical contact with a fluid confined behind a containing wall. Each electrode is connected to a source of different electrical potential. When current is conducted through the fluid between the electrodes, resistance heating in the fluid causes local boiling and thus the formation and expansion of a bubble within the fluid. The electrodes are disposed on either side of an opening in the wall, so that the bubble is formed on one side of the wall in close proximity to the opening. Fluid behavior is such that a fluid jet is formed when the bubble collapses in close proximity to the wall. This jet impacts the bubble in a direction toward the wall.

Abstract: A foldable obstacle system is provided on a hydraulic lifting body to alleviate cloud cavitation and so to reduce noise and surface erosion that might otherwise result from unsteady sheet cavitation and a re-entrant jet produced thereby. The system includes one or more foldable obstacle devices or plates, each of which is movable between a closed position at the surface of the body and an open position away from the body. When a re-entrant jet occurs, the jet acts to lift the plates and rotate them into the open position in which they block the re-entrant jet so as to reduce or prevent cloud cavitation. When cavitation does not occur, the normal fluid flow over the body acts to close and keep closed the obstacle devices or plates so that they do not interfere with the normal fluid flow.

Abstract: The invention relates to an IC chip-planning system and method to provide automatic creation and optimisation of chip-level design plan alternatives that can meet user-specific target chip area/design density, chip shape/aspect ratio, delay/timing closure, and/or congestion/routability objectives at each level of the design—architectural, RTL, gate, structural and physical levels. By combining global searching and local searching, a multi-objective optimisation process and a single-objective optimisation process, the invention can greatly reduce searching and optimisation time. Flexible system structure allows for generation of the optimised chip-planning solutions via an open optimisation train, a small optimisation loop, and/or a large optimisation loop.

Abstract: First and second electrically conductive rods are provided inside a shielded electromagnetic test chamber. These rods are energized to radiate electromagnetic energy inside the chamber. The rods are mounted inside the chamber at right angles to one another, the first rod is movable through the interior volume in a first direction perpendicular to its long axis, and the second rod is movable through the chamber in a second direction perpendicular both to its own long axis and to the first rod's direction of motion. Energy is supplied to the two rods in a way that enhances the uniformity of the electromagnetic field applied to a working volume inside the chamber as the two rods move through the chamber.

Abstract: A valveless micropump includes a hollow pump chamber having a driving element coupled thereto, an inlet channel coupled to the hollow pump chamber, and an outlet channel coupled to the hollow pump chamber. The inlet channel, the hollow pump chamber, and the outlet channel define a fluid flow path through the inlet channel, the hollow pump chamber, and the outlet channel. At least one direction-sensitive element disposed in the flow path within one of the inlet and outlet channels and comprising a direction-sensitive element, is installed at an angle which produces a drag ratio greater than unity on fluid in the flow path. The driving element may comprise an electrostatic/piezoelectric member. Various embodiments of the valveless pump include one or more of the airfoil elements mounted in one, the other or both of the inlet and outlet channels, including embodiments in which one or more cascades of the airfoil elements are mounted in the inlet channel and the outlet channel.

Abstract: A chip planning method, tool and system for generating a population of gene strings representing floor plans for an integrated circuit, executing crossover on the strings to generate crossover child strings, executing mutation on the strings to generate mutated child strings, applying peristalsis operators to the strings to generate peristalsis child strings, and evaluating the child strings for inclusion in the population. The operators are peristalsis operators based on a speckle model. Dynamic control of migration rates and ranking is also executed, together with controlled race migration and immigration. Dynamic ratio control and optimisation of interconnecting area and pin assignment are also executed.

Abstract: This invention relates to an electrostatically operated, normally closed micromachined flow-through microvalve device.

Abstract: A micro-dimensional sensor measures the shear force, both in magnitude and direction, at the surface of a solid boundary as a fluid flows over that boundary. The sensor is a micro-mechanical capacitor-transducer system that includes a micro-dimensioned floating upper plate above a fixed lower plate supported on a substrate. The floating upper plate is mounted and held over the substrate by a number of zig-zap form supporting arms. The flow passing over the upper plate displaces the upper plate in a downstream direction, which results in a measurable change of the capacitance in the capacitor-transducer system. The direction and magnitude of the shear forces can then be obtained from the measured capacitance through specially designed circuitry.

Abstract: A computationally time and space efficient data structure and method and system for using the same for surface rendering. The basis for the new data structure lies in organizing a volume data set for surface rendering into a new format where the cells needed for the surface rendering can be searched and displayed more efficiently. Given a threshold t specified by the user, the present data structure is able to efficiently identify all surface cells saving valuable processing time by providing three unique beneficial characteristics. First, given a threshold t, it can directly provide all S-cells without having to check most of the 1-cells and 0-cells such that no time is wasted on visiting the intermediate nodes. Second, it facilitates significant savings in memory space where the data structure only requires N.sup.3 pointers for data storage saving memory space for all intermediate nodes, i.e. O(N.sup.3) pairs of (Min, Max).