MEMs

Self-Lubrication of Hot YSZ-Ag-Mo Nanocomposite Coatings

An experimental study has been performed to learn about the physical and chemical mechanisms of self-lubrication of coatings that comprise nanostructured composites of yttria-stabilized zirconia (YSZ), silver, and molybdenum. These and other YSZ-based nanocomposite coatings have received increasing attention in recent years because they offer a combination of hardness, toughness, resistance to wear, and low-friction C properties that make them attractive for reducing wear and friction and increasing the lifetimes of hot, sliding components of mechanical systems. In addition to the excellent mechanical and thermal stability of the basic YSZ ceramic material, the nanocomposite structures of these coatings, consisting of combinations of amorphous and crystalline phases, provide a “chameleon” surface adaptation, in which different phases turn into lubricants in response to different test environments, contact loads, sliding speeds, and temperatures. Moreover, proper sizing of nanocrystalline grains can restrict crack sizes and create large volumes of grain boundaries, thereby increasing the toughness and contact-load-bearing capabilities of these coatings.

Posted in: Briefs, Materials, Lubricants, Coatings Colorants and Finishes, Composite materials, Nanomaterials, Wear
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Hybrid Three-Axis Vibration Reducers

Hybrid (passive/active) devices have been developed to reduce the magnitudes of possibly threedimensional vibrations coupled from vibrating equipment on platforms to bases that support the platforms. These hybrid devices are three-axis generalizations of singleaxis hybrid vibration reducers developed and reported previously. Each hybrid device includes rubber passive vibration-isolator pads, piezoelectric actuators, optional piezoelectric force sensors, and accelerometers. Each device operates in conjunction with a computer and control-and-actuation circuitry, which process accelerometer readings using feedforward and/or feedback control laws to excite the piezoelectric actuators with signals having amplitudes and phases chosen to minimize acceleration of the base.

Posted in: Briefs, Mechanical Components, Vibration
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Some Advances in Reducing Drag and Suppressing Convection

Theoretical and computational research has yielded some advances in the art of designing active feedforward and feedback controllers to suppress thermal convection and reduce drag (by suppressing turbulence) in boundary-layer flows. The advances include (1) improved means for designing reduced-order (and, hence, computationally more efficient) controllers and (2) discovery of a previously unknown phenomenon that could be exploited for feedforward control to reduce drag.

Posted in: Briefs, Mechanical Components, Electronic control systems, Drag
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Autonomous Vehicles Would Learn by Mimicking Human Drivers

A program initiated by the Defense Advanced Research Projects Agency (DARPA) and now also pursued by other agencies called “Learning Applied to Ground Robots” (LAGR), is developing control algorithms that would enable a robotic land vehicle, robotic underwater crawler, or other similar autonomous mobile robot to traverse terrain safely. Among the algorithms needed are navigation algorithms for finding and then following a safe path across terrain from a starting or current position to a destination.

Posted in: Briefs, Information Technology, Vehicle drivers, Robotics, Autonomous vehicles
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Advances in Algorithms for CFD and Finite-Element Simulation

A program of research and development has resulted in some advances in algorithms for computational fluid dynamics (CFD), finite-element simulation of solid objects undergoing large deformations, and some related topics. The main advances are summarized as follows:

Posted in: Briefs, Information Technology, Computational fluid dynamics, Finite element analysis
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Shape-Based Recognition of 3D Objects in 2D Images

An object-recognition algorithm analyzes data from two-dimensional (2D) images to locate and identify possibly complexly shaped three-dimensional (3D) objects in possibly highly cluttered scenes depicted in the images. More specifically, the algorithm implements a relatively simple, effective, and fast process for recognizing 2D objects that may be partly occluded and that have shapes that can be modeled by use of sets of line segments (see figure). Because the algorithm tolerates a fair amount of perspective distortion, it is also applicable to 3D objects represented by sets of viewpoint- dependent 2D models.

Posted in: Briefs, Information Technology, Mathematical models, Imaging
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Development Packages for M-Modules and PMCs

MEN Micro, Inc. (Ambler, PA) introduced the Universal Submodule (USM) development packages for M-Modules and PMCs that turn specialized I/O requirements into a series of standard products. The product implements a board’s desired functionality through one or more IP cores in an FPGA, augmenting the flexibility of M-Modules and PMCs with individual functionality. The same USM may be used on M-Modules, PMC modules, XMCs, and conduction- cooled PMC modules. Operating temperature is -40 to 85°C.

Posted in: Products, Products, Electronics & Computers
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Analog Output Boards

United Electronics Industries (UEI, Canton, MA) has released the DNA-AO-308 series of analog output boards for PowerDNA DAQ Cubes. Each board has eight analog output channels with maximum update rates to 100 kHz per channel (800 kHz per board).

Posted in: Products, Products, Electronics & Computers
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Single-Board Computers

Aitech Defense Systems, Inc. (Chatsworth, CA) has expanded the C900 series of rugged 3U CompactPCI (cPCI) single-board computers (SBCs) with the C903, available in air- or conduction-cooled models; both conform to PICMG 2.0 R3.0 and ANSI/VITA 30.1-1991 specifications, respectively.

Posted in: Products, Products, Electronics & Computers
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Dual-Slot Controller

Linear Technology Corp. (Milpitas, CA) offers the LTC4242, a narrow, dual-slot PCI Express Hot Swap™ controller for mid-range networking or storage servers and embedded applications. The device simplifies the application by eliminating complex software interfaces, and allows for independently controlling the main supplies (12 V and 3.3 V) and the auxiliary (3.3 V AUX) supply on two slots.

Posted in: Products, Products, Electronics & Computers
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