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Sample records for seamless electro-mechanical vehicle

  1. Electro-Mechanical Actuators

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The electro-mechanical actuator, a new electronics technology, is an electronic system that provides the force needed to move valves that control the flow of propellant to the engine. It is proving to be advantageous for the main propulsion system plarned for a second generation reusable launch vehicle. Hydraulic actuators have been used successfully in rocket propulsion systems. However, they can leak when high pressure is exerted on such a fluid-filled hydraulic system. Also, hydraulic systems require significant maintenance and support equipment. The electro-mechanical actuator is proving to be low maintenance and the system weighs less than a hydraulic system. The electronic controller is a separate unit powering the actuator. Each actuator has its own control box. If a problem is detected, it can be replaced by simply removing one defective unit. The hydraulic systems must sustain significant hydraulic pressures in a rocket engine regardless of demand. The electro-mechanical actuator utilizes power only when needed. A goal of the Second Generation Reusable Launch Vehicle Program is to substantially improve safety and reliability while reducing the high cost of space travel. The electro-mechanical actuator was developed by the Propulsion Projects Office of the Second Generation Reusable Launch Vehicle Program at the Marshall Space Flight Center.

  2. Micro-electro-mechanical flapping wing technology for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Hall, Asha J.; Riddick, Jaret C.

    2012-04-01

    Army combat operations have placed a high premium on reconnaissance missions for Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs) (less than 15 cm in dimension and less than 20 g in mass). One approach for accomplishing this mission is to develop a biologically inspired flapping wing insect that can maneuver into confined areas and possess hovering capabilities. Analysis of insect flight indicates that in addition to the bending excitation (flapping), simultaneous excitation of the twisting degree-of-freedom (pitching) is required to manipulate the control surface adequately. Traditionally, bimorph piezoelectric PZT (Pb(Zr0.55Ti0.45)O3) actuators have been used in many applications to excite the bending degree-of-freedom. In laminated or layered structures, bend-twist coupling is governed by the existence of at least one anisotropic layer not aligned with the primary plate axes. By adding a layer of off-axis PZT segments to a PZT bimorph actuator, thereby producing a layered structure to be referred to as a functionally- modified bimorph, bend-twist coupling may be introduced to the flexural response of the layered PZT. Furthermore, by selectively charging off-axis layers in specific combinations with the bimorph, the response of the functionally-modified bimorph may be tailored yielding a biaxial actuator to actively control the flapping wing response. The present study presents an experimental investigation of both traditional bimorph and functionally-modified PZT bimorph designs intended for active bend-twist actuation of cm-scale flapping wing devices.

  3. Micro electro-mechanical heater

    DOEpatents

    Oh, Yunje; Asif, Syed Amanulla Syed; Cyrankowski, Edward; Warren, Oden Lee

    2016-04-19

    A sub-micron scale property testing apparatus including a test subject holder and heating assembly. The assembly includes a holder base configured to couple with a sub-micron mechanical testing instrument and electro-mechanical transducer assembly. The assembly further includes a test subject stage coupled with the holder base. The test subject stage is thermally isolated from the holder base. The test subject stage includes a stage subject surface configured to receive a test subject, and a stage plate bracing the stage subject surface. The stage plate is under the stage subject surface. The test subject stage further includes a heating element adjacent to the stage subject surface, the heating element is configured to generate heat at the stage subject surface.

  4. Advanced electro-mechanical micro-shutters for thermal infrared night vision imaging and targeting systems

    NASA Astrophysics Data System (ADS)

    Durfee, David; Johnson, Walter; McLeod, Scott

    2007-04-01

    Un-cooled microbolometer sensors used in modern infrared night vision systems such as driver vehicle enhancement (DVE) or thermal weapons sights (TWS) require a mechanical shutter. Although much consideration is given to the performance requirements of the sensor, supporting electronic components and imaging optics, the shutter technology required to survive in combat is typically the last consideration in the system design. Electro-mechanical shutters used in military IR applications must be reliable in temperature extremes from a low temperature of -40°C to a high temperature of +70°C. They must be extremely light weight while having the ability to withstand the high vibration and shock forces associated with systems mounted in military combat vehicles, weapon telescopic sights, or downed unmanned aerial vehicles (UAV). Electro-mechanical shutters must have minimal power consumption and contain circuitry integrated into the shutter to manage battery power while simultaneously adapting to changes in electrical component operating parameters caused by extreme temperature variations. The technology required to produce a miniature electro-mechanical shutter capable of fitting into a rifle scope with these capabilities requires innovations in mechanical design, material science, and electronics. This paper describes a new, miniature electro-mechanical shutter technology with integrated power management electronics designed for extreme service infra-red night vision systems.

  5. Micro electro mechanical system optical switching

    SciTech Connect

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

    2013-12-17

    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  6. 40 HP Electro-Mechanical Actuator

    NASA Technical Reports Server (NTRS)

    Fulmer, Chris

    1996-01-01

    This report summarizes the work performed on the 40 BP electro-mechanical actuator (EMA) system developed on NASA contract NAS3-25799 for the NASA National Launch System and Electrical Actuation (ELA) Technology Bridging Programs. The system was designed to demonstrate the capability of large, high power linear ELA's for applications such as Thrust Vector Control (TVC) on rocket engines. It consists of a motor controller, high frequency power source, drive electronics and a linear actuator. The power source is a 25kVA 20 kHz Mapham inverter. The drive electronics are based on the pulse population modulation concept and operate at a nominal frequency of 40 kHz. The induction motor is a specially designed high speed, low inertia motor capable of a 68 peak HP. The actuator was originally designed by MOOG Aerospace under an internal R & D program to meet Space Shuttle Main Engine (SSME) TVC requirements. The design was modified to meet this programs linear rate specification of 7.4 inches/second. The motor and driver were tested on a dynamometer at the Martin Marietta Space Systems facility. System frequency response and step response tests were conducted at the Marshall Space Flight Center facility. A complete description of the system and all test results can be found in the body of the report.

  7. Analysis method and principle of dual-mode electro-mechanical variable transmission program

    NASA Astrophysics Data System (ADS)

    Li, Hongcai; Yan, Qingdong; Xiang, Changle; Wang, Weida

    2012-05-01

    Automotive industry, as an important pillar of the national economy, has been rapidly developing in recent years. But proplems such as energy comsumption and environmental pollution are posed at the same time. Electro-mechanical variable transmission system is considered one of avilable workarounds. It is brought forward a kind of design methods of dual-mode electro-mechanical variable transmission system rotational speed characteristics and dual-mode drive diagrams. With the motor operating behavior of running in four quadrants and the speed characteristics of the simple internal and external meshing single planetary gear train, four kinds of dual-mode electro-mechanical transmission system scheme are designed. And the velocity, torque and power characteristics of one of the programs are analyzed. The magnitude of the electric split-flow power is an important factor which influences the system performance, so in the parameters matching design, it needs to reduce the power needs under the first mode of the motor. The motor, output rotational speed range and the position of the mode switching point have relationships with the characteristics design of the planetary gear set. The analysis method is to provide a reference for hybrid vehicles' design. As the involved rotational speed and torque relationships are the natural contact of every part of transmission system, a theory basis of system program and performance analysis is provided.

  8. A methodology for identification and control of electro-mechanical actuators

    PubMed Central

    Tutunji, Tarek A.; Saleem, Ashraf

    2015-01-01

    Mechatronic systems are fully-integrated engineering systems that are composed of mechanical, electronic, and computer control sub-systems. These integrated systems use electro-mechanical actuators to cause the required motion. Therefore, the design of appropriate controllers for these actuators are an essential step in mechatronic system design. In this paper, a three-stage methodology for real-time identification and control of electro-mechanical actuator plants is presented, tested, and validated. First, identification models are constructed from experimental data to approximate the plants’ response. Second, the identified model is used in a simulation environment for the purpose of designing a suitable controller. Finally, the designed controller is applied and tested on the real plant through Hardware-in-the-Loop (HIL) environment. The described three-stage methodology provides the following practical contributions: • Establishes an easy-to-follow methodology for controller design of electro-mechanical actuators. • Combines off-line and on-line controller design for practical performance. • Modifies the HIL concept by using physical plants with computer control (rather than virtual plants with physical controllers). Simulated and experimental results for two case studies, induction motor and vehicle drive system, are presented in order to validate the proposed methodology. These results showed that electromechanical actuators can be identified and controlled using an easy-to-duplicate and flexible procedure. PMID:26150992

  9. A methodology for identification and control of electro-mechanical actuators.

    PubMed

    Tutunji, Tarek A; Saleem, Ashraf

    2015-01-01

    Mechatronic systems are fully-integrated engineering systems that are composed of mechanical, electronic, and computer control sub-systems. These integrated systems use electro-mechanical actuators to cause the required motion. Therefore, the design of appropriate controllers for these actuators are an essential step in mechatronic system design. In this paper, a three-stage methodology for real-time identification and control of electro-mechanical actuator plants is presented, tested, and validated. First, identification models are constructed from experimental data to approximate the plants' response. Second, the identified model is used in a simulation environment for the purpose of designing a suitable controller. Finally, the designed controller is applied and tested on the real plant through Hardware-in-the-Loop (HIL) environment. The described three-stage methodology provides the following practical contributions: •Establishes an easy-to-follow methodology for controller design of electro-mechanical actuators.•Combines off-line and on-line controller design for practical performance.•Modifies the HIL concept by using physical plants with computer control (rather than virtual plants with physical controllers). Simulated and experimental results for two case studies, induction motor and vehicle drive system, are presented in order to validate the proposed methodology. These results showed that electromechanical actuators can be identified and controlled using an easy-to-duplicate and flexible procedure. PMID:26150992

  10. Integrated micro-electro-mechanical sensor development for inertial applications

    SciTech Connect

    Allen, J.J.; Kinney, R.D.; Sarsfield, J.

    1998-04-01

    Electronic sensing circuitry and micro electro mechanical sense elements can be integrated to produce inertial instruments for applications unheard of a few years ago. This paper will describe the Sandia M3EMS fabrication process, inertial instruments that have been fabricated, and the results of initial characterization tests of micro-machined accelerometers.

  11. Electro-mechanical sensing in freestanding monolayered gold nanoparticle membranes

    NASA Astrophysics Data System (ADS)

    Gauvin, M.; Grisolia, J.; Alnasser, T.; Viallet, B.; Xie, S.; Brugger, J.; Ressier, L.

    2016-06-01

    The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain-induced length variation of the interparticle junctions. This work thus evidences a new class of highly sensitive nano-electro-mechanical systems based on freestanding monolayered gold NP membranes.The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain

  12. A nonlinear generalized continuum approach for electro-mechanical coupling

    NASA Astrophysics Data System (ADS)

    Skatulla, S.; Arockiarajan, A.; Sansour, C.

    2008-07-01

    Electro-active polymers (EAP) are "smart materials" whose mechanical properties may be changed significantly by the application of electric field. Hence, these materials can serve as actuators in electro-mechanical systems, artificial muscles, etc. In this paper, we provide a generalized continuum framework basis for the characterization of the nonlinear electroelastic properties of these materials. This approach introduces new strain and stress measures which lead to the formulation of a corresponding generalized variational principle. The theory is then completed by Dirichlet boundary conditions for the displacement field and the electric potential and then derivatives normal to the boundary. The basic idea behind this generalized continuum framework is the consideration of a micro- and a macro-space which together span the generalized space. All quantities including the constitutive law for the electro-mechanically coupled nonlinear hyperelasticity are defined in the generalized space. Numerical examples are presented to demonstrate the numerical accuracy of the implemented formulation using the mesh free method.

  13. Portable electro-mechanically cooled high-resolution germanium detector

    NASA Astrophysics Data System (ADS)

    Neufeld, K. W.; Ruhter, W. D.

    1995-05-01

    We have integrated a small, highly-reliable, electro-mechanical cryo-cooler with a high-resolution germanium detector for portable/field applications. The system weighs 6.8 kg and requires 40 watts of power to operate once the detector is cooled to its operating temperature. The detector is a 500 mm(exp 2) by 20-mm thick low-energy configuration that gives a full-width at half maximum (FWHM) energy resolution of 523 eV at 122 keV, when cooled with liquid nitrogen. The energy resolution of the detector, when cooled with the electro-mechanical cooler, is 570 eV at 122 keV. We have field tested this system in measurements of plutonium and uranium for isotopic and enrichment information using the MGA and MGAU analysis programs without any noticeable effects on the results.

  14. Development of electro-mechanical actuator for TR-1A rocket

    NASA Astrophysics Data System (ADS)

    Mori, Hidehiko; Kochiyama, Jiro; Miwada, Makoto; Sato, Toshiaki; Fujiwara, Teruo; Watanabe, Yasushi; Ohtuka, Hirohito; Fujii, Hiroshi

    TR-1A, a microgravity experiment rocket of the National Space Development Agency of Japan (NASDA), is equiped with an attitude control system with four canards to make the summit of the trajectory high, lengthening the microgravity time period for the experiment and also to make dispersion of the splashdown area narrow for the convenience of the payload recovery. The canards are driven by electro-mechanical actuators. The canards and actuators are located in the interstage section, to be separated from the payload before the microgravity experiment is commenced. Lessons learned in various development tests using engineering and prototype models of the actuator were reflected in the design and fabrication of the flight model actuator. The first flight of TR-1A was conducted on September 16, 1991 at Tanegashima Space Center of NASDA with successful completion of planned microgravity experiments. The electro-mechanical actuators worked perfectly to control the rocket vehicle attitude as programmed throughout the time period of separation of the payload after liftoff.

  15. Micro Electro-Mechanical System (MEMS) Pressure Sensor for Footwear

    DOEpatents

    Kholwadwala, Deepesh K.; Rohrer, Brandon R.; Spletzer, Barry L.; Galambos, Paul C.; Wheeler, Jason W.; Hobart, Clinton G.; Givler, Richard C.

    2008-09-23

    Footwear comprises a sole and a plurality of sealed cavities contained within the sole. The sealed cavities can be incorporated as deformable containers within an elastic medium, comprising the sole. A plurality of micro electro-mechanical system (MEMS) pressure sensors are respectively contained within the sealed cavity plurality, and can be adapted to measure static and dynamic pressure within each of the sealed cavities. The pressure measurements can provide information relating to the contact pressure distribution between the sole of the footwear and the wearer's environment.

  16. Micro-electro-mechanically switchable near infrared complementary metamaterial absorber

    SciTech Connect

    Pitchappa, Prakash; Pei Ho, Chong; Kropelnicki, Piotr; Singh, Navab; Kwong, Dim-Lee; Lee, Chengkuo

    2014-05-19

    We experimentally demonstrate a micro-electro-mechanically switchable near infrared complementary metamaterial absorber by integrating the metamaterial layer to be the out of plane movable microactuator. The metamaterial layer is electrostatically actuated by applying voltage across the suspended complementary metamaterial layer and the stationary bottom metallic reflector. Thus, the effective spacing between the metamaterial layer and bottom metal reflector is varied as a function of applied voltage. With the reduction of effective spacing between the metamaterial and reflector layers, a strong spectral blue shift in the peak absorption wavelength can be achieved. With spacing change of 300 nm, the spectral shift of 0.7 μm in peak absorption wavelength was obtained for near infrared spectral region. The electro-optic switching performance of the device was characterized, and a striking switching contrast of 1500% was achieved at 2.1 μm. The reported micro-electro-mechanically tunable complementary metamaterial absorber device can potentially enable a wide range of high performance electro-optical devices, such as continuously tunable filters, modulators, and electro-optic switches that form the key components to facilitate future photonic circuit applications.

  17. Electro-Mechanical Systems for Extreme Space Environments

    NASA Technical Reports Server (NTRS)

    Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

    2011-01-01

    Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller

  18. Thermo-electro-mechanical instability of dielectric elastomers

    NASA Astrophysics Data System (ADS)

    Liu, Liwu; Liu, Yanju; Li, Bo; Yang, Kai; Li, Tiefeng; Leng, Jinsong

    2011-07-01

    We here propose a new method to analyze the thermo-electro-mechanical instability of dielectric elastomers. The equilibrium equations in this thermodynamic system at different temperatures are initially established. We then obtained the critical nominal electric field and the critical stretch under various mechanical and thermal loads, involving the effects of different stretch regimes on the system stability, i.e. the equal-biaxial stretch, the unequal-biaxial stretch and the thickness elongation. Finally, numerical results showed that as the temperature increases, the critical nominal electric field and the stretch of the dielectric elastomer are strengthened, which consequently stabilize the system. The results provide guidance to the design and synthesis of dielectric elastomer-based devices, especially for those operating at various temperatures.

  19. Gallium nitride-based micro-opto-electro-mechanical systems

    NASA Astrophysics Data System (ADS)

    Stonas, Andreas Robert

    Gallium Nitride and its associated alloys InGaN and AlGaN have many material properties that are highly desirable for micro-electro-mechanical systems (MEMS), and more specifically micro-opto-electro-mechanical systems (MOEMS). The group III-nitrides are tough, stiff, optically transparent, direct bandgap, chemically inert, highly piezoelectric, and capable of functioning at high temperatures. There is currently no other semiconductor system that possesses all of these properties. Taken together, these attributes make the nitrides prime candidates not only for creating new versions of existing device structures, but also for creating entirely unique devices which combine these properties in novel ways. Unfortunately, their chemical resiliency also makes the group III-nitrides extraordinarily difficult to shape into devices. In particular, until this research, no undercut etch technology existed that could controllably separate a selected part of a MEMS device from its sapphire or silicon carbide substrate. This has effectively prevented GaN-based MEMS from being developed. This dissertation describes how this fabrication obstacle was overcome by a novel etching geometry (bandgap-selective backside-illuminated photoelectochemical (BS-BIPEC) etching) and its resulting morphologies. Several gallium-nitride based MEMS devices were created, actuated, and modelled, including cantilevers and membranes. We describe in particular our pursuit of one of the many novel device elements that is possible only in this material system: a transducer that uses an externally applied strain to dynamically change the optical transition energy of a quantum well. While the device objective of a dynamically tunable quantum well was not achieved, we have demonstrated sufficient progress to believe that such a device will be possible soon. We have observed a shift (5.5meV) of quantum well transition energies in released structures, and we have created structures that can apply large biaxial

  20. Carbon-based nano-electro-mechanical systems

    NASA Astrophysics Data System (ADS)

    Kaul, A. B.; Khan, A. R.; Megerian, K. G.; Epp, L.; LeDuc, H. G.; Bagge, L.; Jennings, A. T.; Jang, D.; Greer, J. R.

    2010-04-01

    We provide an overview of our work where carbon-based nanostructures have been applied to twodimensional (2D) planar and three-dimensional (3D) vertically-oriented nano-electro-mechanical (NEM) switches. In the first configuration, laterally oriented single-walled nanotubes (SWNTs) synthesized using thermal chemical vapor deposition (CVD) were implemented for forming bridge-type 2D NEMS switches, where switching voltages were on the order of a few volts. In the second configuration, vertically oriented carbon nanofibers (CNFs) synthesized using plasma-enhanced (PE) CVD have been explored for their potential application in 3D NEMS. We have performed nanomechanical measurements on such vertically oriented tubes using nanoindentation to determine the mechanical properties of the CNFs. Electrostatic switching was demonstrated in the CNFs synthesized on refractory metallic nitride substrates, where a nanoprobe was used as the actuating electrode inside a scanning-electron-microscope. The switching voltages were determined to be in the tens of volts range and van der Waals interactions at these length scales appeared significant, suggesting such structures are promising for nonvolatile memory applications. A finite element model was also developed to determine a theoretical pull-in voltage which was compared to experimental results.

  1. Progress in understanding electro-mechanical signalling in the myometrium.

    PubMed

    Wray, S; Burdyga, T; Noble, D; Noble, K; Borysova, L; Arrowsmith, S

    2015-02-01

    In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity. PMID:25439280

  2. Carbon-Based Nano-Electro-Mechanical-Systems

    NASA Technical Reports Server (NTRS)

    Kaul, A. B.; Khan, A. R.; Megerian, K. G.; Epp, L.; LeDuc, G.; Bagge, L.; Jennings, A. T.; Jang, D.; Greer, J. R.

    2011-01-01

    We provide an overview of our work where carbon-based nanostructures have been applied to two-dimensional (2D) planar and three-dimensional (3D) vertically-oriented nano-electro-mechanical (NEM) switches. In the first configuration, laterally oriented single-walled nanotubes (SWNTs) synthesized using thermal chemical vapor deposition (CVD) were implemented for forming bridge-type 2D NEMS switches, where switching voltages were on the order of a few volts. In the second configuration, vertically oriented carbon nanofibers (CNFs) synthesized using plasma-enhanced (PE) CVD have been explored for their potential application in 3D NEMS. We have performed nanomechanical measurements on such vertically oriented tubes using nanoindentation to determine the mechanical properties of the CNFs. Electrostatic switching was demonstrated in the CNFs synthesized on refractory metallic nitride substrates, where a nanoprobe was used as the actuating electrode inside a scanning-electron-microscope. The switching voltages were determined to be in the tens of volts range and van der Waals interactions at these length scales appeared significant, suggesting such structures are promising for nonvolatile memory applications. A finite element model was also developed to determine a theoretical pull-in voltage which was compared to experimental results.

  3. Electro-Mechanical Actuator. DC Resonant Link Controller

    NASA Technical Reports Server (NTRS)

    Schreiner, Kenneth E.

    1996-01-01

    This report summarizes the work performed on the 68 HP electro-mechanical actuator (EMA) system developed on NASA contract for the Electrical Actuation (ELA) Technology Bridging Program. The system was designed to demonstrate the capability of large, high power linear ELAs for applications such as Thrust Vector Control (TVC) on rocket engines. It consists of a motor controller, drive electronics and a linear actuator capable of up to 32,00 lbs loading at 7.4 inches/second. The drive electronics are based on the Resonant DC link concept and operate at a nominal frequency of 55 kHz. The induction motor is a specially designed high speed, low inertia motor capable of a 68 peak HP. The actuator was originally designed by MOOG Aerospace under an internal R & D program to meet Space Shuttle Main Engine (SSME) TVC requirements. The design was modified to meet this programs linear rate specification of 7.4 inches/second. The motor and driver were tested on a dynamometer at the Martin Marietta Space Systems facility. System frequency response, step response and force-velocity tests were conducted at the MOOG Aerospace facility. A complete description of the system and all test results can be found in the body of the report.

  4. Controlling Micro ElectroMechanical Systems (MEMS) in Space

    NASA Astrophysics Data System (ADS)

    Farrar, D.; Schneider, W.; Osiander, R.; Champion, J. L.; Darrin, A. G.; Douglas, D.; Swanson, T. D.

    2003-01-01

    Small spacecraft, including micro and nanosats, as they are envisioned for future missions, will require an alternative means to achieve thermal control due to their small power and mass budgets. One of the proposed alternatives is Variable Emittance (Vari-E) Coatings for spacecraft radiators. Space Technology-5 (ST-5) is a technology demonstration mission through NASA Goddard Space Flight Center (GSFC) that will utilize Vari-E Coatings. This mission involves a constellation of three (3) satellites in a highly elliptical orbit with a perigee altitude of ~200 km and an apogee of ~38,000 km. Such an environment will expose the spacecraft to a wide swing in the thermal and radiation environment of the earth's atmosphere. There are three (3) different technologies associated with this mission. The three technologies are electrophoretic, electrochromic, and Micro ElectroMechanical Systems (MEMS). The ultimate goal is to make use of Vari-E coatings, in order to achieve various levels of thermal control. The focus of this paper is to highlight the Vari-E Coating MEMS instrument, with an emphasis on the Electronic Control Unit responsible for operating the MEMS device. The Test & Evaluation approach, along with the results, is specific for application on ST-5, yet the information provides a guideline for future experiments and/or thermal applications on the exterior structure of a spacecraft.

  5. Using Neural Networks in Decision Making for a Reconfigurable Electro Mechanical Actuator (EMA)

    NASA Technical Reports Server (NTRS)

    Latino, Carl D.

    2001-01-01

    The objectives of this project were to demonstrate applicability and advantages of a neural network approach for evaluating the performance of an electro-mechanical actuator (EMA). The EMA in question was intended for the X-37 Advanced Technology Vehicle. It will have redundant components for safety and reliability. The neural networks for this application are to monitor the operation of the redundant electronics that control the actuator in real time and decide on the operating configuration. The system we proposed consists of the actuator, sensors, control circuitry and dedicated (embedded) processors. The main purpose of the study was to develop suitable hardware and neural network capable of allowing real time reconfiguration decisions to be made. This approach was to be compared to other methods such as fuzzy logic and knowledge based systems considered for the same application. Over the course of the project a more general objective was the identification of the other neural network applications and the education of interested NASA personnel on the topic of Neural Networks.

  6. Graphene NanoElectroMechanical Resonators and Oscillators

    NASA Astrophysics Data System (ADS)

    Chen, Changyao

    Made of only one sheet of carbon atoms, graphene is the thinnest yet strongest material ever exist. Since its discovery in 2004, graphene has attracted tremendous research effort worldwide. Guaranteed by the superior electrical and excellent mechanical properties, graphene is the ideal building block for NanoElectroMechanical Systems (NEMS). In the first parts of the thesis, I will discuss the fabrications and measurements of typical graphene NEMS resonators, including doubly clamped and fully clamped graphene mechanical resonators. I have developed a electrical readout technique by using graphene as frequency mixer, demonstrated resonant frequencies in range from 30 to 200 MHz. Furthermore, I developed the advanced fabrications to achieve local gate structure, which led to the real-time resonant frequency detection under resonant channel transistor (RCT) scheme. Such real-time detection improve the measurement speed by 2 orders of magnitude compared to frequency mixing technique, and is critical for practical applications. Finally, I employed active balanced bridge technique in order to reduce overall electrical parasitics, and demonstrated pure capacitive transduction of graphene NEMS resonators. Characterizations of graphene NEMS resonators properties are followed, including resonant frequency and quality factor (Q) tuning with tension, mass and temperatures. A simple continuum mechanics model was constructed to understand the frequency tuning behavior, and it agrees with experimental data extremely well. In the following parts of the thesis, I will discuss the behavior of graphene mechanical resonators in applied magnetic field, i.e. in Quantum Hall (QH) regime. The couplings between mechanical motion and electronic band structure turned out to be a direct probe for thermodynamic quantities, i.e., chemical potential and compressibility. For a clean graphene resonators, with quality factors of 1 x 104, it underwent resonant frequency oscillations as applied

  7. Thermo-electro-mechanical postbuckling of piezoelectric FG-CNTRC beams with geometric imperfections

    NASA Astrophysics Data System (ADS)

    Wu, Helong; Kitipornchai, Sritawat; Yang, Jie

    2016-09-01

    This paper presents thermo-electro-mechanical postbuckling analysis of geometrically imperfect functionally graded carbon nanotube-reinforced composite (FG-CNTRC) hybrid beams that are integrated with surface-bonded piezoelectric actuators. The material properties of FG-CNTRCs are assumed to be temperature-dependent and graded in the thickness direction. By using a generic imperfection function, various possible imperfections with different shapes and locations in the beam are considered. The theoretical formulations are based on the first-order shear deformation beam theory with von-Kármán nonlinearity. A differential quadrature approximation based iteration process is employed to obtain the postbuckling equilibrium path of piezoelectric FG-CNTRC hybrid beams under thermo-electro-mechanical loading. Parametric studies are conducted to examine the effect of geometric imperfection, distribution pattern and volume fraction of carbon nanotubes, temperature rise, actuator voltage, beam geometry and boundary conditions on the thermo-electro-mechanical postbuckling behaviour. The results show that the thermo-electro-mechanical postbuckling is considerably affected by the imperfection mode, half-wave number, location and amplitude, as well as the temperature rise and boundary conditions. The effect of applied actuator voltage is much less pronounced but tends to be relatively more noticeable as the slenderness ratio increases.

  8. The Seamless Monument.

    ERIC Educational Resources Information Center

    Pucci, Barbara

    2002-01-01

    Presents an interview with Daniel Paley Ellison. Discusses how Ellison's time in Poland and Japan has influenced his approach to educating children about the nature of suffering and the necessity for empathy. Describes how his Seamless Monument Project uses historical conflict as a springboard to explore the roots of violence and the issues of…

  9. Electro-mechanical properties of hydrogel composites with micro- and nano-cellulose fillers

    NASA Astrophysics Data System (ADS)

    N, Mohamed Shahid U.; Deshpande, Abhijit P.; Lakshmana Rao, C.

    2015-09-01

    Stimuli responsive cross-linked hydrogels are of great interest for applications in diverse fields such as sensors and biomaterials. In this study, we investigate polymer composites filled with cellulose fillers. The celluloses used in making the composites were a microcrystalline cellulose of commercial grade and cellulose nano-whiskers obtained through acid hydrolysis of microcrystalline cellulose. The filler concentration was varied and corresponding physical, mechanical and electro-mechanical characterization was carried out. The electro-mechanical properties were determined using a quasi-static method. The fillers not only enhance the mechanical properties of the composite by providing better reinforcement but also provide a quantitative electric potential in the composite. The measurements reveal that the polymer composites prepared from two different cellulose fillers possess a quantitative electric potential which can be utilized in biomedical applications. It is argued that the mechanism behind the quantitative electric potential in the composites is due to streaming potentials arising due to electrical double layer formation.

  10. 41. View of electro/mechanical fiber optic system panel in transmitter ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. View of electro/mechanical fiber optic system panel in transmitter building no. 102. Images projected to screen (panel at upper left) are projected to back side of screen located in MWOC to display changing information. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  11. Nanomechanical and Electro-mechanical Characterization of Materials for Flexible Electrodes Applications

    NASA Astrophysics Data System (ADS)

    Peng, Cheng

    Flexible electronics attract research and commercial interests in last 2 decades for its flexibility, low cost, light weight and etc. To develop and improve the electro-mechanical properties of flexible electrodes is the most critical and important step. In this work, we have performed nanomechanical and electromechanical characterization of materials for flexible electrode applications, including metallic nanowires (NWs), indium tin oxide (ITO)-based and carbon nanotube (CNT)-based electrodes. First, we designed and developed four different testing platforms for nanomechanical and electro-mechanical characterization purpose. For the nano/sub-micro size samples, the micro mechanical devices can be used for uniaxial and bi-axial loading tests. For the macro size samples, the micro tester will be used for in situ monotonic tensile test, while the fatigue tester can be used for in situ cyclic tensile or bending testing purpose. Secondly, we have investigated mechanical behaviors of single crystalline Ni nanowires and single crystalline Cu nanowires under uni-axial tensile loading inside a scanning electron microscope (SEM) chamber. We demonstrated both size and strain-rate dependence on yield stress of single-crystalline Ni NWs with varying diameters (from 100 nm to 300 nm), and the molecular dynamics (MD) simulation helped to confirm and understand the experimental phenomena. Also, two different fracture modes, namely ductile and brittle-like fractures, were found in the same batch of Cu nanowire samples. Finally, we studied the electro-mechanical behaviors of flexible electrodes in macro scale. We reported a coherent study integrating in situ electro-mechanical experiments and mechanics modeling to decipher the failure mechanics of ITO-based and CNTbased electrodes under tension. It is believed that our combined experimental and simulation results provide some further insights into the important yet complicated deformation mechanisms for nanoscale metals and

  12. The deformable secondary mirror of VLT: final electro-mechanical and optical acceptance test results

    NASA Astrophysics Data System (ADS)

    Briguglio, Runa; Biasi, Roberto; Xompero, Marco; Riccardi, Armando; Andrighettoni, Mario; Pescoller, Dietrich; Angerer, Gerald; Gallieni, Daniele; Vernet, Elise; Kolb, Johann; Arsenault, Robin; Madec, Pierre-Yves

    2014-07-01

    The Deformable Secondary Mirror (DSM) for the VLT ended the stand-alone electro-mechanical and optical acceptance process, entering the test phase as part of the Adaptive Optics Facility (AOF) at the ESO Headquarter (Garching). The VLT-DSM currently represents the most advanced already-built large-format deformable mirror with its 1170 voice-coil actuators and its internal metrology based on co-located capacitive sensors to control the shape of the 1.12m-diameter 2mm-thick convex shell. The present paper reports the final results of the electro-mechanical and optical characterization of the DSM executed in a collaborative effort by the DSM manufacturing companies (Microgate s.r.l. and A.D.S. International s.r.l.), INAF-Osservatorio Astrofisico di Arcetri and ESO. The electro-mechanical acceptance tests have been performed in the company premises and their main purpose was the dynamical characterization of the internal control loop response and the calibration of the system data that are needed for its optimization. The optical acceptance tests have been performed at ESO (Garching) using the ASSIST optical test facility. The main purpose of the tests are the characterization of the optical shell flattening residuals, the corresponding calibration of flattening commands, the optical calibration of the capacitive sensors and the optical calibration of the mirror influence functions.

  13. Seamless/bonded niobium cavities

    NASA Astrophysics Data System (ADS)

    Singer, W.

    2006-07-01

    Technological aspects and performance of seamless cavities produced by hydroforming are presented. Problems related to the fabrication of seamless cavities from bulk niobium are mainly solved thanks to the progress of the last years. The highest achieved accelerating gradients are comparable for both seamless and welded versions (ca. 40 MV/m) Nevertheless further development of seamless cavities is desirable in order to avoid the careful preparation of parts for welding and get reliable statistic. Fabrication of NbCu clad cavities from bimetallic tubes is an interesting option that gives new opportunity to the seamless technique. On the one hand it allows reducing the niobium costs contribution; on the other hand it increases the thermal stability of the cavity. The highest accelerating gradient achieved on seamless NbCu clad single cell cavities (ca. 40 MV/m) is comparable to the one reached on bulk Nb cavities. Fabrication of multi-cell NbCu cavities by hydroforming was recently proven.

  14. Detection of Dynabeads using a micro-electro-mechanical-systems fluxgate sensor

    NASA Astrophysics Data System (ADS)

    Lei, Jian; Wang, Tao; Lei, Chong; Zhou, Yong

    2013-01-01

    This paper presents an approach to detect the presence of Dynabeads with a system based on a micro fluxgate sensor fabricated by micro-electro-mechanical systems technology. Due to the excellent performance of the micro fluxgate sensor, the detection system exhibited many advantages, such as lower minimum detectable limit, small weight, and low power consumption. Experimental results show that, applied an external magnetic field in a range of 430 μT to 600 μT, Dynabeads with a concentration as low as 0.1 μg/ml can be detected by this system. Moreover, the detection system could give an approximate quantitation to the magnetic beads.

  15. Characteristics of semiconductor bridge (SCB) plasma generated in a micro-electro-mechanical system (MEMS)

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Uk; Park, Chong-Ook; Park, Myung-Il; Kim, Sun-Hwan; Lee, Jung-Bok

    2002-12-01

    Plasma ignition method has been applied in various fields particularly to the rocket propulsion, pyrotechnics, explosives, and to the automotive air-bag system. Ignition method for those applications should be safe and also operate reliably in hostile environments such as; electromagnetic noise, drift voltage, electrostatic background and so on. In the present Letter, a semiconductor bridge (SCB) plasma ignition device was fabricated and its plasma characteristics including the propagation speed of the plasma, plasma size, and plasma temperature were investigated with the aid of the visualization of micro scale plasma (i.e., ⩽350 μm), which generated from a micro-electro-mechanical poly-silicon semiconductor bridge (SCB).

  16. A Method for Evaluating the Electro-Mechanical Characteristics of Piezoelectric Actuators during Motion

    PubMed Central

    Jin, Tao; Takita, Akihiro; Djamal, Mitra; Hou, Wenmei; Jia, Hongzhi; Fujii, Yusaku

    2012-01-01

    The electro-mechanical characteristics of piezoelectric actuators which have being driven are evaluated in this paper. The force generated by actuators is measured as an inertial force of a corner cub prism which is attached to the actuators. The Doppler frequency shift of a laser beam, due to the motion of actuator, is accurately measured by a heterodyne interferometer. Subsequently, the mechanical quantities, such as velocity, acceleration, force, power and displacement, are calculated from the Doppler frequency shift. With the measurement results of current and voltage of the actuator, the relationships between electrical and mechanical characteristics are evaluated.

  17. A High-order Eulerian-Lagrangian Finite Element Method for Coupled Electro-mechanical Systems

    NASA Astrophysics Data System (ADS)

    Brandstetter, Gerd

    The main focus of this work is on the development of a high-order Eulerian-Lagrangian finite element method for the simulation of electro-mechanical systems. The coupled problem is solved by a staggered scheme, where the mechanical motion is discretized by standard Lagrangian finite elements, and the electrical field is solved on a fixed Eulerian grid with embedded boundary conditions. Traditional Lagrangian-Lagrangian or arbitrary Lagrangian-Eulerian (ALE) methods encounter deficiencies, for example, when dealing with mesh distortion due to large deformations, or topology changes due to contacting bodies. The presented Eulerian-Lagrangian approach addresses these issues in a natural way. Within this context we develop a high-order immersed boundary discontinuous-Galerkin (IB-DG) method, which is shown to be necessary for (i) the accurate representation of the electrical gradient along nonlinear boundary features such as singular corners, and (ii) to achieve full convergence during the iterative global solution. We develop an implicit scheme based on the mid-point rule, as well as an explicit scheme based on the centered-difference method, with the incorporation of energy conserving, frictionless contact algorithms for an elastic-to-rigid-surface contact. The performance of the proposed method is assessed for several benchmark tests: the electro-static force vector around a singular corner, the quasi-static pull-in of an electro-mechanically actuated switch, the excitation of a carbon nanotube at resonance, and the cyclic impact simulation of a micro-electro-mechanical resonant-switch. We report improved accuracy for the high-order method as compared to low-order methods, and linear convergence in the iterative solution of the staggered scheme. Additionally, we investigate a Newton-Krylov shooting scheme in order to directly find cyclic steady states of electro-mechanical devices excited at resonance-- as opposed to a naive time-stepping from zero initial

  18. A process for the agile product realization of electro-mechanical devices

    SciTech Connect

    Forsythe, C.; Ashby, M.R.; Benavides, G.L.; Diegert, K.V.; Jones, R.E.; Longcope, D.B.; Parratt, S.W.

    1995-09-01

    This paper describes a product realization process developed and demonstrated at Sandia by the A-PRIMED (Agile Product Realization for Innovative Electro MEchanical Devices) project that integrates many of the key components of ``agile manufacturing`` into a complete, design-to-production process. Evidence indicates that the process has reduced the product realization cycle and assured product quality. Products included discriminators for a robotic quick change adapter and for an electronic defense system. These discriminators, built using A-PRIMED, met random vibration requirements and had life cycles that far surpass the performance obtained from earlier efforts.

  19. Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

    PubMed Central

    Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

    2016-01-01

    A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery. PMID:27193507

  20. Fabrication and electrical characterization of graphene formed chemically on nickel nano electro mechanical system (NEMS) switch.

    PubMed

    Choe, Byeong-In; Lee, Jung-Kyu; Lee, Bora; Kim, Kwanyong; Choi, Woo Young; Hong, Byung Hee; Lee, Jong-Ho

    2014-12-01

    In this work, we successfully fabricated a reliable nano-electro-mechanical system (NEMS) switch with graphene formed chemically on pre-patterned nickel (Ni) film movable beam. Its electrical characteristics were investigated in terms of current-voltage (I-V) and repetitive switching (on/off) properties. The graphene in the movable beam was selectively formed chemically only on the patterned Ni film. Graphene material may help overcome the stiction and reliability problems in nano-electro-mechanical devices. A study on graphene cantilever already has been reported by using only single or multi-layer of transferred graphene. However, the graphene selectively grown on Ni film has not been reported for NEMS switch. The graphene grown on Ni film by chemical vapor deposition method (CVD) were characterized by Raman spectroscopy. The fabricated lateral NEMS switch has w/l/t = 500 nm/20 μm/150 nm as a Ni dimension and an air-gap of -300 nm in lateral direction. The fabricated graphene movable beam formed chemically on Ni film shows reduced pull-in voltage and improved endurance (extended repetitive switching operations). PMID:25971076

  1. Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

    2016-05-01

    A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.

  2. A Diagnostic Approach for Electro-Mechanical Actuators in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Balaban, Edward; Saxena, Abhinav; Bansal, Prasun; Goebel, Kai Frank; Stoelting, Paul; Curran, Simon

    2009-01-01

    Electro-mechanical actuators (EMA) are finding increasing use in aerospace applications, especially with the trend towards all all-electric aircraft and spacecraft designs. However, electro-mechanical actuators still lack the knowledge base accumulated for other fielded actuator types, particularly with regard to fault detection and characterization. This paper presents a thorough analysis of some of the critical failure modes documented for EMAs and describes experiments conducted on detecting and isolating a subset of them. The list of failures has been prepared through an extensive Failure Modes and Criticality Analysis (FMECA) reference, literature review, and accessible industry experience. Methods for data acquisition and validation of algorithms on EMA test stands are described. A variety of condition indicators were developed that enabled detection, identification, and isolation among the various fault modes. A diagnostic algorithm based on an artificial neural network is shown to operate successfully using these condition indicators and furthermore, robustness of these diagnostic routines to sensor faults is demonstrated by showing their ability to distinguish between them and component failures. The paper concludes with a roadmap leading from this effort towards developing successful prognostic algorithms for electromechanical actuators.

  3. Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste

    SciTech Connect

    Panos G. Datskos; Michael J. Sepaniak; Nickolay Lavrik; Pampa Dutta; Mustafa Culha

    2005-12-28

    The main objective of this research program is to develop robust and reliable micro-electro-mechanical sensing systems, based on microcantilevers (MCs), that can operate in liquid environments with high levels of sensitivity and selectivity. The chemical responses of MCs result from analyte-induced differential stress at the cantilever surfaces. We aim to employ various surface nanostructuring strategies that enhance these stresses and hence the degree of static bending of the cantilevers. Receptor phases as self assembled monolayers (SAMs) and thin films are being synthesized and tested to provide selectivity. Selectivity is chemically enhanced by using different phases on individual MCs in arrays and by adding a spectroscopic component, surface enhanced Raman spectrometry (SERS), in hybrid approaches to sensing. Significant progress was made in tasks that were listed in the work plan for DOE EMSP project ''Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste''. Several project areas are listed below and discussed and referenced to our literature on the topics.

  4. An electro-mechanical periodic system with piezoelectric transducers and coupled circuitry: dynamic analysis and applications

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Tang, J.

    2010-04-01

    In this paper, we integrate piezoelectric transducers and coupled circuitry, which themselves form an electrical periodic system, onto a mechanical structure to form an electro-mechanical periodic system. The overall dynamics of the electro-mechanical system can thus be altered by tuning the electrical parameters. A transfer-matrix-based modeling technique is adopted in the dynamic analysis, where each element is represented by two state vectors at its both ends with a transfer matrix relating them. As the transfer matrix has the advantage on describing harmonic motions within the element, the global analysis can be facilitated given the repetitive nature of periodic systems. Numerical simulations are conducted to demonstrate the characteristics of wave propagation and attenuation in terms of propagation constants. Effects of each tunable parameter are also discussed through detailed parametric analysis. The proposed system can be tailored to various engineering needs. One example is adaptive vibration isolation with tunable effective frequency range. Another example is vibration energy harvesting through the piezoelectric transducers and circuitry.

  5. Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes.

    PubMed

    Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R

    2016-01-01

    A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery. PMID:27193507

  6. A process for the agile product realization of electro-mechanical devices

    SciTech Connect

    Forsythe, C.; Diegert, K.V.; Ashby, M.R.; Parratt, S.W.; Benavides, G.L.; Jones, R.E.; Longcope, D.B.

    1995-08-01

    This paper describes a product realization process developed at Sandia National Laboratories by the A-PRIMED project that integrates many of the key components of ``agile manufacturing`` into a complete, step-by-step, design-to-production process. For three separate product realization efforts, each geared to a different set of requirements, A-PRIMED demonstrated product realization of a custom device in less than a month. A-PRIMED used a discriminator (a precision electro-mechanical device) as the demonstration device, but the process is readily adaptable to other electro-mechanical products. The process begins with a qualified design parameter space. From that point, the product realization process encompasses all facets of requirements development, analysis and testing, design, manufacturing, robotic assembly and quality assurance, as well as product data management and concurrent engineering. In developing the product realization process, A-PRIMED employed an iterative approach whereby after each of three builds, the process was reviewed and refinements made on the basis of lessons learned. This paper describes the integration of project functions and product realization technologies, with references to reports detailing specific facets of the overall process. The process described herein represents the outcome of an empirically-based process development effort that on repeated iterations, was proven successful.

  7. The seamless computing environment

    SciTech Connect

    Sheehan, T.J.; Papadopoulos, P.M.; Alexander, R.

    1997-06-01

    Oak Ridge National Laboratory (ORNL), Sandia National Laboratories (SNL), and Pittsburgh Supercomputing Center (PSC) are in the midst of a project through which their supercomputers are linked via high speed networks. The goal of this project is to solve national security and scientific problems too large to run on a single machine. This project, as well as the desire to maximize the use of high performance computing systems, has provided the impetus to develop and implement software tools and infrastructure to automate the tasks associated with running codes on one or more heterogeneous machines from a geographically distributed pool. The ultimate goal of this effort is the Seamless Computing Environment (SCE). SCE is a production environment to which a user submits a job and receives results without having to worry about scheduling resources or even which resources the system uses. The compilation, data migration, scheduling, and execution will take place with minimal user intervention.

  8. Seamless tiled display system

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor); Kolosowsky, Aleksandra (Inventor)

    2006-01-01

    A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

  9. A boundary element method for detection of damages and self-diagnosis of transducers using electro-mechanical impedance

    NASA Astrophysics Data System (ADS)

    Zou, Fangxin; Aliabadi, M. H.

    2015-09-01

    In this paper, for the first time, a boundary element method (BEM) for modelling the electro-mechanical responses of three-dimensional structures is reported. Within an electro-mechanically coupled system, the host structure is formulated using the 3D dual boundary element method in order to be able to take into account the possible existence of cracks, and the piezoelectric transducers, which are the key to measuring electro-mechanical impedance (EMI), are modelled using a semi-analytical finite element approach. The analyses of the coupled system are performed in the frequency domain. The EMI signatures computed by the BEM developed in this work show excellent agreement with those obtained using the finite element method and from experiments. Using parametric studies, the potential of using EMI signatures for the detection of damages in structures and for the self-diagnosis of transducers is assessed.

  10. Effect of Microstructure on the Electro-Mechanical Behaviour of Cu Films on Polyimide

    NASA Astrophysics Data System (ADS)

    Berger, J.; Glushko, O.; Marx, V. M.; Kirchlechner, C.; Cordill, M. J.

    2016-05-01

    Metal films on polymer substrates are commonly used in flexible electronic devices and may be exposed to large deformations during application. For flexible electronics, the main requirement is to remain conductive while stretching and compressing. Therefore, the electro-mechanical behaviour of 200-nm-thick Cu films on polyimide with two different microstructures (as-deposited and annealed) were studied by executing in situ fragmentation experiments with x-ray diffraction, under an atomic force microscope, and with 4-point probe resistance measurements in order to correlate the plastic deformation with the electrical behaviour. The three in situ techniques clearly demonstrate different behaviours controlled by the microstructure. Interestingly, the as-deposited film with a bi-modal microstructure is more suited for flexible electronic applications than an annealed film with homogenous 1-µm-sized grains. The as-deposited film reaches a higher yield stress, with unchanged electrical conductivity, and does not show extensive surface deformation during straining.

  11. Multiple internal seal right micro-electro-mechanical system vacuum package

    NASA Technical Reports Server (NTRS)

    Hayworth, Ken J. (Inventor); Yee, Karl Y. (Inventor); Shcheglov, Kirill V. (Inventor); Bae, Youngsam (Inventor); Wiberg, Dean V. (Inventor); Challoner, A. Dorian (Inventor); Peay, Chris S. (Inventor)

    2007-01-01

    A Multiple Internal Seal Ring (MISR) Micro-Electro-Mechanical System (MEMS) vacuum package that hermetically seals MEMS devices using MISR. The method bonds a capping plate having metal seal rings to a base plate having metal seal rings by wafer bonding the capping plate wafer to the base plate wafer. Bulk electrodes may be used to provide conductive paths between the seal rings on the base plate and the capping plate. All seals are made using only metal-to-metal seal rings deposited on the polished surfaces of the base plate and capping plate wafers. However, multiple electrical feed-through metal traces are provided by fabricating via holes through the capping plate for electrical connection from the outside of the package through the via-holes to the inside of the package. Each metal seal ring serves the dual purposes of hermetic sealing and providing the electrical feed-through metal trace.

  12. Chemo-electro-mechanical modeling of pH-sensitive hydrogels

    NASA Astrophysics Data System (ADS)

    Wallmersperger, Thomas; Keller, Karsten; Kröplin, Bernd; Günther, Margarita; Gerlach, Gerald

    2011-04-01

    Hydrogels are viscoelastic active materials. They consist of a polymer network with bound charges and a liquid phase with mobile anions and cations. In water based solutions these gels show large swelling capabilities under the influence of different possible stimulation types, such as chemical, electrical or thermal stimulation. In the present work a coupled chemo-electro-mechanical formulation for polyelectrolyte gels using the Finite Element Method (FEM) is applied. In addition to the three given fields, the dissociation reactions of the bound charges in the gel are considered. Thus, we are able to model and simulate pH-stimulation and to give the different ion concentrations, the electric potential and the mechanical displacement. Depending on the initial conditions and the dissociation ratio, different kinds of stimulation cycles can be simulated. Concluding, the developed model is applicable for chemical stimulation and can model both, hydrogel actuators and sensors.

  13. An experimental evaluation of the fully coupled hysteretic electro-mechanical behaviour of piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Butcher, Mark; Davino, Daniele; Giustiniani, Alessandro; Masi, Alessandro

    2016-04-01

    Piezoelectrics are the most commonly used of the multifunctional smart materials in industrial applications, because of their relatively low cost and ease of use in electric and electronic oriented applications. Nevertheless, while datasheets usually give just small signal quasi-static parameters, their full potential can only be exploited only if a full characterization is available because the maximum stroke or the higher piezo coupling coefficients are available at different electro-mechanical biases, where often small signal analysis is not valid. In this paper a method to get the quasi-static fully coupled characterization is presented. The method is tested on a commercial piezo actuator but can be extended to similar devices.

  14. Multiple internal seal ring micro-electro-mechanical system vacuum packaging method

    NASA Technical Reports Server (NTRS)

    Hayworth, Ken J. (Inventor); Yee, Karl Y. (Inventor); Shcheglov, Kirill V. (Inventor); Bae, Youngsam (Inventor); Wiberg, Dean V. (Inventor); Challoner, A. Dorian (Inventor); Peay, Chris S. (Inventor)

    2008-01-01

    A Multiple Internal Seal Ring (MISR) Micro-Electro-Mechanical System (MEMS) vacuum packaging method that hermetically seals MEMS devices using MISR. The method bonds a capping plate having metal seal rings to a base plate having metal seal rings by wafer bonding the capping plate wafer to the base plate wafer. Bulk electrodes may be used to provide conductive paths between the seal rings on the base plate and the capping plate. All seals are made using only metal-to-metal seal rings deposited on the polished surfaces of the base plate and capping plate wafers. However, multiple electrical feed-through metal traces are provided by fabricating via holes through the capping plate for electrical connection from the outside of the package through the via-holes to the inside of the package. Each metal seal ring serves the dual purposes of hermetic sealing and providing the electrical feed-through metal trace.

  15. Effect of Microstructure on the Electro-Mechanical Behaviour of Cu Films on Polyimide

    NASA Astrophysics Data System (ADS)

    Berger, J.; Glushko, O.; Marx, V. M.; Kirchlechner, C.; Cordill, M. J.

    2016-06-01

    Metal films on polymer substrates are commonly used in flexible electronic devices and may be exposed to large deformations during application. For flexible electronics, the main requirement is to remain conductive while stretching and compressing. Therefore, the electro-mechanical behaviour of 200-nm-thick Cu films on polyimide with two different microstructures (as-deposited and annealed) were studied by executing in situ fragmentation experiments with x-ray diffraction, under an atomic force microscope, and with 4-point probe resistance measurements in order to correlate the plastic deformation with the electrical behaviour. The three in situ techniques clearly demonstrate different behaviours controlled by the microstructure. Interestingly, the as-deposited film with a bi-modal microstructure is more suited for flexible electronic applications than an annealed film with homogenous 1- µm-sized grains. The as-deposited film reaches a higher yield stress, with unchanged electrical conductivity, and does not show extensive surface deformation during straining.

  16. Application of Micro-Electro-Mechanical Sensors Contactless NDT of Concrete Structures

    PubMed Central

    Ham, Suyun; Popovics, John S.

    2015-01-01

    The utility of micro-electro-mechanical sensors (MEMS) for application in air-coupled (contactless or noncontact) sensing to concrete nondestructive testing (NDT) is studied in this paper. The fundamental operation and characteristics of MEMS are first described. Then application of MEMS sensors toward established concrete test methods, including vibration resonance, impact-echo, ultrasonic surface wave, and multi-channel analysis of surface waves (MASW), is demonstrated. In each test application, the performance of MEMS is compared with conventional contactless and contact sensing technology. Favorable performance of the MEMS sensors demonstrates the potential of the technology for applied contactless NDT efforts. Objective: To illustrate the utility of air-coupled MEMS sensors for concrete NDT, as compared with conventional sensor technology. PMID:25897497

  17. Thin broadband noise absorption through acoustic reactance control by electro-mechanical coupling without sensor.

    PubMed

    Zhang, Yumin; Chan, Yum-Ji; Huang, Lixi

    2014-05-01

    Broadband noise with profound low-frequency profile is prevalent and difficult to be controlled mechanically. This study demonstrates effective broadband sound absorption by reducing the mechanical reactance of a loudspeaker using a shunt circuit through electro-mechanical coupling, which induces reactance with different signs from that of loudspeaker. An RLC shunt circuit is connected to the moving coil to provide an electrically induced mechanical impedance which counters the cavity stiffness at low frequencies and reduces the system inertia above the resonance frequency. A sound absorption coefficient well above 0.5 is demonstrated across frequencies between 150 and 1200 Hz. The performance of the proposed device is superior to existing passive absorbers of the same depth (60 mm), which has lower frequency limits of around 300 Hz. A passive noise absorber is further proposed by paralleling a micro-perforated panel with shunted loudspeaker which shows potentials in absorbing band-limit impulse noise. PMID:24815257

  18. Micro-Electro-Mechanical-Systems-Based Micro-Ro-Boat Utilizing Steam as Propulsion Power

    NASA Astrophysics Data System (ADS)

    Choi, Ju Chan; Choi, Young Chan; Kyoo Lee, June; Kong, Seong Ho

    2012-06-01

    We report the design and fabrication of a micro-electro-mechanical-systems (MEMS)-based microactuator, that floats on the surface of water and is driven by steam. We named the actuator “micro-Ro-boat”, a compound word created from the words “robot” and “boat”. The MEMS-based micro-Ro-boat utilizes steam as the propulsion power, giving it a high speed and long lifetime. A hydrophobic surface has been utilized for the wing of the actuator to enhance the buoyancy. Instead of using gas or fuel, the proposed micro-Ro-boat utilizes steam form electrically heated water. The velocity of the micro-Ro-boat is in the range of 0.5-2 cm/s and the maximum loading capability for a device size of 10 ×10 mm2 is 0.4 g.

  19. Tuning of the electro-mechanical behavior of the cellular carbon nanotube structures with nanoparticle dispersions

    SciTech Connect

    Gowda, Prarthana; Misra, Abha; Ramamurty, Upadrasta

    2014-03-10

    The mechanical and electrical characteristics of cellular network of the carbon nanotubes (CNT) impregnated with metallic and nonmetallic nanoparticles were examined simultaneously by employing the nanoindentation technique. Experimental results show that the nanoparticle dispersion not only enhances the mechanical strength of the cellular CNT by two orders of magnitude but also imparts variable nonlinear electrical characteristics; the latter depends on the contact resistance between nanoparticles and CNT, which is shown to depend on the applied load while indentation. Impregnation with silver nanoparticles enhances the electrical conductance, the dispersion with copper oxide and zinc oxide nanoparticles reduces the conductance of CNT network. In all cases, a power law behavior with suppression in the differential conductivity at zero bias was noted, indicating electron tunneling through the channels formed at the CNT-nanoparticle interfaces. These results open avenues for designing cellular CNT foams with desired electro-mechanical properties and coupling.

  20. Recent trends in reinforcement corrosion assessment using piezo sensors via electro mechanical impedance technique

    NASA Astrophysics Data System (ADS)

    Visalakshi, Talakokula; Bhalla, Suresh; Gupta, Ashok; Bhattacharjee, Bishwajit

    2014-03-01

    Reinforced concrete (RC) is an economical, versatile and successful construction material as it can be moulded into a variety of shapes and finishes. In most cases, it is durable and strong, performing well throughout its service life. However, in some cases, it does not perform adequately due to various reasons, one of which is the corrosion of the embedded steel bars used as reinforcement. . Although the electro-mechanical impedance (EMI) technique is well established for damage detection and quantification of civil, mechanical and aerospace structures, only limited studies have been reported of its application for rebar corrosion detection in RC structures. This paper presents the recent trends in corrosion assessment based on the model derived from the equivalent structural parameters extracted from the impedance spectrum of concrete-rebar system using the lead zirconate titanate (PZT) sensors via EMI technique.

  1. Micro-electro-mechanically tunable metamaterial with enhanced electro-optic performance

    SciTech Connect

    Pitchappa, Prakash; Pei Ho, Chong; Lin, Yu-Sheng; Lee, Chengkuo; Kropelnicki, Piotr; Singh, Navab; Huang, Chia-Yi

    2014-04-14

    We experimentally demonstrate a micro-electro-mechanically tunable metamaterial with enhanced electro-optical performance by increasing the number of movable cantilevers in the symmetrical split ring resonator metamaterial unit cell. Simulations were carried out to understand the interaction of the incident terahertz radiation with out-of-plane deforming metamaterial resonator. In order to improve the overall device performance, the number of released cantilever in a unit cell was increased from one to two, and it was seen that the tunable range was doubled and the switching contrast improved by a factor of around five at 0.7 THz. This simple design approach can be adopted for a wide range of high performance electro-optical devices such as continuously tunable filters, modulators, and electro-optic switches to enable future photonic circuit applications.

  2. Diffusion Bonding of Silicon Carbide for a Micro-Electro-Mechanical Systems Lean Direct Injector

    NASA Technical Reports Server (NTRS)

    Halbig, Michael C.; Singh, Mrityunjay; Shpargel, Tarah P.; Kiser, James D.

    2006-01-01

    Robust approaches for joining silicon carbide (SiC) to silicon carbide sub-elements have been developed for a micro-electro-mechanical systems lean direct injector (MEMS LDI) application. The objective is to join SiC sub-elements to form a leak-free injector that has complex internal passages for the flow and mixing of fuel and air. Previous bonding technology relied upon silicate glass interlayers that were not uniform or leak free. In a newly developed joining approach, titanium foils and physically vapor deposited titanium coatings were used to form diffusion bonds between SiC materials during hot pressing. Microscopy results show the formation of well adhered diffusion bonds. Initial tests show that the bond strength is much higher than required for the component system. Benefits of the joining technology are fabrication of leak free joints with high temperature and mechanical capability.

  3. Effect of materials for micro-electro-mechanical systems on PCR yield.

    PubMed

    Potrich, Cristina; Lunelli, Lorenzo; Forti, Stefania; Vozzi, Diego; Pasquardini, Laura; Vanzetti, Lia; Panciatichi, Cristina; Anderle, Mariano; Pederzolli, Cecilia

    2010-05-01

    In this study we analyzed the surface properties of different silicon-based materials used for micro-electro-mechanical systems (MEMS) production, such as thermally grown silicon oxide, plasma-enhanced chemical vapor deposition (PECVD)-treated silicon oxide, reactive-ion etch (RIE)-treated silicon oxide, and Pyrex. Substrates were characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to define the surface chemical and morphological properties, and by fluorescence microscopy to directly assess the absorption of the different polymerase chain reaction (PCR) components. By using microchips fabricated with the same materials we investigated their compatibility with PCR reactions, exploiting the use of different enzymes and reagents or proper surface treatments. We established the best conditions for DNA amplification in silicon/Pyrex microdevices depending on the type of device and fabrication method used and the quality of reagents, rather than on the passivation treatment or increment in standard Taq polymerase concentration. PMID:19455320

  4. Electro-mechanical dysfunction in long QT syndrome: Role for arrhythmogenic risk prediction and modulation by sex and sex hormones.

    PubMed

    Lang, C N; Menza, M; Jochem, S; Franke, G; Perez Feliz, S; Brunner, M; Koren, G; Zehender, M; Bugger, H; Jung, B A; Foell, D; Bode, C; Odening, K E

    2016-01-01

    Long QT syndrome (LQTS) is a congenital arrhythmogenic channelopathy characterized by impaired cardiac repolarization. Increasing evidence supports the notion that LQTS is not purely an "electrical" disease but rather an "electro-mechanical" disease with regionally heterogeneously impaired electrical and mechanical cardiac function. In the first part, this article reviews current knowledge on electro-mechanical (dys)function in LQTS, clinical consequences of the observed electro-mechanical dysfunction, and potential underlying mechanisms. Since several novel imaging techniques - Strain Echocardiography (SE) and Magnetic Resonance Tissue Phase Mapping (TPM) - are applied in clinical and experimental settings to assess the (regional) mechanical function, advantages of these non-invasive techniques and their feasibility in the clinical routine are particularly highlighted. The second part provides novel insights into sex differences and sex hormone effects on electro-mechanical cardiac function in a transgenic LQT2 rabbit model. Here we demonstrate that female LQT2 rabbits exhibit a prolonged time to diastolic peak - as marker for contraction duration and early relaxation - compared to males. Chronic estradiol-treatment enhances these differences in time to diastolic peak even more and additionally increases the risk for ventricular arrhythmia. Importantly, time to diastolic peak is particularly prolonged in rabbits exhibiting ventricular arrhythmia - regardless of hormone treatment - contrasting with a lack of differences in QT duration between symptomatic and asymptomatic LQT2 rabbits. This indicates the potential added value of the assessment of mechanical dysfunction in future risk stratification of LQTS patients. PMID:26718598

  5. A SUGGESTED CURRICULUM GUIDE FOR ELECTRO-MECHANICAL TECHNOLOGY ORIENTED SPECIFICALLY TO THE COMPUTER AND BUSINESS MACHINE FIELDS. INTERIM REPORT.

    ERIC Educational Resources Information Center

    LESCARBEAU, ROLAND F.; AND OTHERS

    A SUGGESTED POST-SECONDARY CURRICULUM GUIDE FOR ELECTRO-MECHANICAL TECHNOLOGY ORIENTED SPECIFICALLY TO THE COMPUTER AND BUSINESS MACHINE FIELDS WAS DEVELOPED BY A GROUP OF COOPERATING INSTITUTIONS, NOW INCORPORATED AS TECHNICAL EDUCATION CONSORTIUM, INCORPORATED. SPECIFIC NEEDS OF THE COMPUTER AND BUSINESS MACHINE INDUSTRY WERE DETERMINED FROM…

  6. Revision of Electro-Mechanical Drafting Program to Include CAD/D (Computer-Aided Drafting/Design). Final Report.

    ERIC Educational Resources Information Center

    Snyder, Nancy V.

    North Seattle Community College decided to integrate computer-aided design/drafting (CAD/D) into its Electro-Mechanical Drafting Program. This choice necessitated a redefinition of the program through new curriculum and course development. To initiate the project, a new industrial advisory council was formed. Major electronic and recruiting firms…

  7. Low-power feedback-enhanced electro-mechanical impedance (FEMI) sensors

    NASA Astrophysics Data System (ADS)

    Jang, Ji Eun; Yue, C. Patrick

    2008-03-01

    Electro-mechanical impedance (EMI) method utilizing smart piezoelectric sensors has emerged as a promising technology for structural health monitoring in civil, mechanical and aerospace engineering. However, two major limiting factors have prevented field deployment of this method in real life. First, smart piezoelectric sensors, such as Lead Zirconate Titanate (PZT) patches, are highly sensitive to environmental changes such as temperature, humidity, and vibration. Secondly, bulky and expensive equipment is needed for performing impedance measurement. This paper proposes a feedback-enhanced electro-mechanical impedance (FEMI) technique for improving robustness against environmental variations and a design of a low-power EMI sensor with built-in measurement circuitries based on this new technique. The proposed FEMI technique employs a feedback scheme to amplify the peaking characteristics of the natural resonance frequencies in the EMI frequency response. The feedback loop includes a phase-locked loop (PLL) and a transimpedance amplifier (TIA). An analog EMI measurement circuit is developed to replace bulky EMI measurement instruments. To keep the power consumption low, the proposed system does not require any analog-to-digital conversion or DSP circuit blocks, but uses a simple analog mixer to multiply input and output waveforms of the PZT sensor, and then extract the EMI amplitude by passing the mixer output through a low-pass filter (LPF). The performance of the proposed FEMI sensor is verified by simulations using MATLAB. Simulated natural frequency peaks in the EMI spectrum are noticeably sharper with the feedback scheme than the one without feedback. As a result, the natural frequency shift due to any structural change can be more easily detected. To quantify the shift of these natural frequency peaks, the root mean square deviation (RMSD) of the difference between cases with and without damage is calculated. The simulation results show that the RMSD with

  8. Comb-drive micro-electro-mechanical systems oscillators for low temperature experiments.

    PubMed

    González, M; Zheng, P; Garcell, E; Lee, Y; Chan, H B

    2013-02-01

    We have designed and characterized micro-electro-mechanical systems (MEMS) for applications at low temperatures. The mechanical resonators were fabricated using a surface micromachining process. The devices consist of a pair of parallel plates with a well defined gap. The top plate can be actuated for shear motion relative to the bottom fixed plate through a set of comb-drive electrodes. Details on the operation and fabrication of the devices are discussed. The geometry was chosen to study the transport properties of the fluid entrained in the gap. An atomic force microscopy study was performed in order to characterize the surface. A full characterization of their resonance properties in air and at room temperature was conducted as a function of pressure, from 10 mTorr to 760 Torr, ranging from a highly rarefied gas to a hydrodynamic regime. We demonstrate the operation of our resonator at low temperatures immersed in superfluid (4)He and in the normal and superfluid states of (3)He down to 0.3 mK. These MEMS oscillators show potential for use in a wide range of low temperature experiments, in particular, to probe novel phenomena in quantum fluids. PMID:23464242

  9. A Noise Level Prediction Method Based on Electro-Mechanical Frequency Response Function for Capacitors

    PubMed Central

    Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

    2013-01-01

    The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective. PMID:24349105

  10. Temperature and time dependence of the electro-mechanical properties of flexible active fiber composites

    NASA Astrophysics Data System (ADS)

    Ben Atitallah, H.; Ounaies, Z.; Muliana, A.

    2016-04-01

    Active fiber composites (AFCs) are comprised of piezoelectric fibers embedded in a polymeric matrix. AFCs use interdigitated electrodes, which produce electric field lines parallel to the fiber direction, thus taking advantage of the larger d 33 piezoelectric coefficient. The polymer volume content of the AFCs is generally more than 50%; since polymers tend to have behaviors affected by their viscoelastic characteristics especially at elevated temperatures, it is necessary to understand the thermo-electro-mechanical behavior of AFCs at different loading rates. In this study, mechanical, electrical and electromechanical properties of AFCs were measured at different isothermal temperatures, namely 25 °C, 50 °C and 75 °C and at different loading rates. The measurements of all the properties of AFCs were done along the fiber direction. It was found that at higher temperatures, the modulus and tensile strength decreased for all strain rates and the strain at failure increased. The remnant polarization increased with decrease in frequency and increase in temperature; however, the coercive field decreased with temperature and was not affected by the frequency. Due to the viscoelastic behavior of the epoxy, the piezoelectric coefficient d 33 increased at higher temperature and lower frequency. It was also noted that this coefficient is dependent on the magnitude of the electric field.

  11. RF Micro-Electro-Mechanical Systems Capacitive Switches Using Ultra Thin Hafnium Oxide Dielectric

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Onodera, Kazumasa; Maeda, Ryutaro

    2006-01-01

    A π-type RF capacitive switch using about 45-nm-thick HfO2 dielectric layer was fabricated. High isolation performance was obtained in wide-band range when the switch was down-state. The isolation was better than -40 dB at the frequency range of 4-35 GHz. Particularly, the isolation was better than -50 dB in the frequency range of 8-12 GHz, i.e., X band. HfO2 showed excellent process compatibility with conventional microfabrication procedure. The 45-nm-thick HfO2 film was prepared using sputtering at room temperature so that it was feasible to be integrated into RF switch and other microwave circuits. The results of constant bias stressing showed that the ultra thin HfO2 had excellent reliability. The electric breakdown of HfO2 was observed, which had no apparent negative effects on the reliability of the dielectric. HfO2 dielectrics were attractive in the application of RF micro-electro-mechanical systems (MEMS) switch for new generation of low-loss high-linearity microwave circuits.

  12. Electro-Mechanical Simulation of a Large Aperture MOEMS Fabry-Perot Tunable Filter

    NASA Technical Reports Server (NTRS)

    Kuhn, Jonathan L.; Barclay, Richard B.; Greenhouse, Matthew A.; Mott, D. Brent; Satyapal, Shobita; Powers, Edward I. (Technical Monitor)

    2000-01-01

    We are developing a micro-machined electrostatically actuated Fabry-Perot tunable filter with a large clear aperture for application in high through-put wide-field imaging spectroscopy and lidar systems. In the first phase of this effort, we are developing key components based on coupled electro-mechanical simulations. In particular, the movable etalon plate design leverages high coating stresses to yield a flat surface in drum-head tension over a large diameter (12.5 mm). In this approach, the cylindrical silicon movable plate is back etched, resulting in an optically coated membrane that is suspended from a thick silicon support ring. Understanding the interaction between the support ring, suspended membrane, and coating is critical to developing surfaces that are flat to within stringent etalon requirements. In this work, we present the simulations used to develop the movable plate, spring suspension system, and electrostatic actuation mechanism. We also present results from tests of fabricated proof of concept components.

  13. Experimental Identification of Smartphones Using Fingerprints of Built-In Micro-Electro Mechanical Systems (MEMS).

    PubMed

    Baldini, Gianmarco; Steri, Gary; Dimc, Franc; Giuliani, Raimondo; Kamnik, Roman

    2016-01-01

    The correct identification of smartphones has various applications in the field of security or the fight against counterfeiting. As the level of sophistication in counterfeit electronics increases, detection procedures must become more accurate but also not destructive for the smartphone under testing. Some components of the smartphone are more likely to reveal their authenticity even without a physical inspection, since they are characterized by hardware fingerprints detectable by simply examining the data they provide. This is the case of MEMS (Micro Electro-Mechanical Systems) components like accelerometers and gyroscopes, where tiny differences and imprecisions in the manufacturing process determine unique patterns in the data output. In this paper, we present the experimental evaluation of the identification of smartphones through their built-in MEMS components. In our study, three different phones of the same model are subject to repeatable movements (composing a repeatable scenario) using an high precision robotic arm. The measurements from MEMS for each repeatable scenario are collected and analyzed. The identification algorithm is based on the extraction of the statistical features of the collected data for each scenario. The features are used in a support vector machine (SVM) classifier to identify the smartphone. The results of the evaluation are presented for different combinations of features and Inertial Measurement Unit (IMU) outputs, which show that detection accuracy of higher than 90% is achievable. PMID:27271630

  14. Mechatronic Scanning System with Integrated Micro Electro Mechanical System Position Sensors

    NASA Astrophysics Data System (ADS)

    Stavrov, Vladimir; Chakarov, Dimitar; Shulev, Assen; Tsveov, Mihail

    2016-06-01

    In this paper, a study of a mechatronic scanning system for application in the microbiology, microelectronics research, chemistry, etc. is presented. Integrated silicon micro electro mechanical system (MEMS) position sensor is used for monitoring the displacement of the scanning system. The utilized silicon MEMS sensors with sidewall embedded piezoresistors possess a number of key advantages such as high sensitivity, low noise and extremely low temperature dependence. Design of 2D scanning system with a travel range of 22 × 22 μm2 has been presented in present work. This system includes a Compliant Transmission Mechanism, (CTM) designed as a complex elastic mechanism, comprising four parallelograms. Computer aided desigh (CAD) model and finite element analysis (FEA) of the Compliant Transmission Mechanism mechanisms have been carried out. A prototype of the scanning system is fabricated, based on CAD model. An experimental set-up of an optical system and a correlation technique for digital image processing have been used for testing the scanning system prototype. Results of the experimental investigations of the prototyped scanning system are also presented.

  15. Experimental Identification of Smartphones Using Fingerprints of Built-In Micro-Electro Mechanical Systems (MEMS)

    PubMed Central

    Baldini, Gianmarco; Steri, Gary; Dimc, Franc; Giuliani, Raimondo; Kamnik, Roman

    2016-01-01

    The correct identification of smartphones has various applications in the field of security or the fight against counterfeiting. As the level of sophistication in counterfeit electronics increases, detection procedures must become more accurate but also not destructive for the smartphone under testing. Some components of the smartphone are more likely to reveal their authenticity even without a physical inspection, since they are characterized by hardware fingerprints detectable by simply examining the data they provide. This is the case of MEMS (Micro Electro-Mechanical Systems) components like accelerometers and gyroscopes, where tiny differences and imprecisions in the manufacturing process determine unique patterns in the data output. In this paper, we present the experimental evaluation of the identification of smartphones through their built-in MEMS components. In our study, three different phones of the same model are subject to repeatable movements (composing a repeatable scenario) using an high precision robotic arm. The measurements from MEMS for each repeatable scenario are collected and analyzed. The identification algorithm is based on the extraction of the statistical features of the collected data for each scenario. The features are used in a support vector machine (SVM) classifier to identify the smartphone. The results of the evaluation are presented for different combinations of features and Inertial Measurement Unit (IMU) outputs, which show that detection accuracy of higher than 90% is achievable. PMID:27271630

  16. Bond-slip detection of concrete-encased composite structure using electro-mechanical impedance technique

    NASA Astrophysics Data System (ADS)

    Liang, Yabin; Li, Dongsheng; Parvasi, Seyed Mohammad; Kong, Qingzhao; Lim, Ing; Song, Gangbing

    2016-09-01

    Concrete-encased composite structure is a type of structure that takes the advantages of both steel and concrete materials, showing improved strength, ductility, and fire resistance compared to traditional reinforced concrete structures. The interface between concrete and steel profiles governs the interaction between these two materials under loading, however, debonding damage between these two materials may lead to severe degradation of the load transferring capacity which will affect the structural performance significantly. In this paper, the electro-mechanical impedance (EMI) technique using piezoceramic transducers was experimentally investigated to detect the bond-slip occurrence of the concrete-encased composite structure. The root-mean-square deviation is used to quantify the variations of the impedance signatures due to the presence of the bond-slip damage. In order to verify the validity of the proposed method, finite element model analysis was performed to simulate the behavior of concrete-steel debonding based on a 3D finite element concrete-steel bond model. The computed impedance signatures from the numerical results are compared with the results obtained from the experimental study, and both the numerical and experimental studies verify the proposed EMI method to detect bond slip of a concrete-encased composite structure.

  17. Electro-mechanical modeling of the piezoresistive response of carbon nanotube polymer composites

    NASA Astrophysics Data System (ADS)

    Xu, S.; Rezvanian, O.; Zikry, M. A.

    2013-05-01

    A coupled electro-mechanical FE approach was developed to investigate the piezoresistive response of carbon nanotube polymer composites. Gauge factors (GFs) and resistance variations of CNT-polymer composite systems were obtained by coupling Maxwell equations to mechanical loads and deformations through initial piezoresistive coefficients of the CNTs, the epoxy, and the tunnel regions, for different arrangements, percolated paths, tunnel distances, and tensile, compressive, and bending loading conditions. A scaling relation between GFs and applied strains was obtained to understand how variations in loading conditions and CNT arrangements affect sensing capabilities and piezoresistive carbon nanotube polymer composite behavior. These variations in GFs were then used to understand how the coupled strains, stresses and current densities vary for aligned and percolated paths for the different loading conditions, CNT arrangements, and tunnel distances. For the percolated path under tensile loading conditions, elastic strains as high as 16% and electrical conductivities that were four orders in magnitude greater than the initial matrix conductivity were obtained. Results for the three loading conditions clearly demonstrate that electrical conductivity and sensing capabilities can be optimized as a function of percolation paths, tunneling distance, orientation, and loading conditions for piezoresistive applications with large elastic strains and conductivities.

  18. Softening and Hardening of a Micro-electro-mechanical systems (MEMS) Oscillator in a Nonlinear Regime

    NASA Astrophysics Data System (ADS)

    Johnson, Sarah; Edmonds, Terrence

    Micro-electro-mechanical systems or MEMS are used in a variety of today's technology and can be modeled using equations for nonlinear damped harmonic oscillators. Mathematical expressions have been formulated to determine resonance frequency shifts as a result of hardening and softening effects in MEMS devices. In this work we experimentally test the previous theoretical analysis of MEMS resonance frequency shifts in the nonlinear regime. Devices were put under low pressure at room temperature and swept through a range of frequencies with varying AC and DC excitation voltages to detect shifts in the resonant frequency. The MEMS device studied in this work exhibits a dominating spring softening effect due to the device's physical make-up. The softening effect becomes very dominant as the AC excitation is increased and the frequency shift of the resonance peak becomes quite significant at these larger excitations. Hardening effects are heavily dependent on mechanical factors that make up the MEMS devices. But they are not present in these MEMS devices. I will present our results along with the theoretical analysis of the Duffing oscillator model. This work was supported by NSF grant DMR-1461019 (REU) and DMR-1205891 (YL).

  19. Comparative study of chemo-electro-mechanical transport models for an electrically stimulated hydrogel

    NASA Astrophysics Data System (ADS)

    Elshaer, S. E.; Moussa, W. A.

    2014-07-01

    The main objective of this work is to introduce a new expression for the hydrogel’s hydration for use within the Poisson Nernst-Planck chemo electro mechanical (PNP CEM) transport models. This new contribution to the models support large deformation by considering the higher order terms in the Green-Lagrangian strain tensor. A detailed discussion of the CEM transport models using Poisson Nernst-Planck (PNP) and Poisson logarithmic Nernst-Planck (PLNP) equations for chemically and electrically stimulated hydrogels will be presented. The assumptions made to simplify both CEM transport models for electric field application in the order of 0.833 kV m-1 and a highly diluted electrolyte solution (97% is water) will be explained. This PNP CEM model has been verified accurately against experimental and numerical results. In addition, different definitions for normalizing the parameters are used to derive the dimensionless forms of both the PNP and PLNP CEM. Four models, PNP CEM, PLNP CEM, dimensionless PNP CEM and dimensionless PNLP CEM transport models were employed on an axially symmetric cylindrical hydrogel problem with an aspect ratio (diameter to thickness) of 175:3. The displacement and osmotic pressure obtained for the four models are compared against the variation of the number of elements for finite element analysis, simulation duration and solution rate when using the direct numerical solver.

  20. The potential of micro-electro-mechanical accelerometers in human vibration measurements

    NASA Astrophysics Data System (ADS)

    Tarabini, Marco; Saggin, Bortolino; Scaccabarozzi, Diego; Moschioni, Giovanni

    2012-01-01

    This paper evaluates the advantages and the drawbacks deriving from the use of MEMS (micro-electro-mechanical systems) accelerometers for hand-arm and whole-body vibration measurements. Metrological performances of different transducers were assessed through the identification of their frequency response function, linearity, floor noise and sensitivity to thermal and electromagnetic disturbances. Experimental results highlighted a standard instrumental uncertainty (including the nonlinearity) lower than 5% with the single frequency calibration procedure, such a value was reduced to 2%. The temperature effect was negligible and the electromagnetic disturbances sensitivity was comparable to that of the piezoelectric accelerometers. The compatibility of measurements obtained with MEMS accelerometers with those of piezoelectric-based measurement chains was verified for two specific applications. An example of direct transducer fixation on the skin for vibration transmissibility measurements is also presented. Thanks to the MEMS peculiarities - mainly small sizes and low cost - since novel approaches in the vibration monitoring could be pursued. For instance, it is possible to include by design MEMS accelerometers in any hand-held tool at the operator interface, or inside the seats structures of cars, tractors and trucks. This could be a viable solution to easily obtain repeatable exposure measurements and could also provide diagnostic signals for the tools or seats of functional monitoring.

  1. Broadband opto-electro-mechanical effective refractive index tuning on a chip.

    PubMed

    Pruessner, Marcel W; Park, Doweon; Stievater, Todd H; Kozak, Dmitry A; Rabinovich, William S

    2016-06-27

    Photonic integrated circuits have enabled progressively active functionality in compact devices with the potential for large-scale integration. To date the lowest loss photonic circuits are achieved with silica or silicon nitride-based platforms. However, these materials generally lack reconfigurability. In this work we present a platform for achieving active functionality in any dielectric waveguide via large-scale opto-electro-mechanical tuning of the effective refractive index (Δneff≈0.01-0.1) and phase (Δϕ>2π). A suspended microbridge weakly interacts with the evanescent field of a low-mode confinement waveguide to tune the effective refractive index and phase with minimal loss. Metal-coated bridges enable electrostatic actuation to displace the microbridge to dynamically tune nEFF. In a second implementation we place a non-metallized dielectric microbridge in a gradient electric field to achieve actuation and tuning. Both approaches are broadband, universally applicable to any waveguide, and pave the way for adding active functionality to many passive optical materials. PMID:27410554

  2. Hard quasiamorphous carbon -- A prospective construction material for micro-electro-mechanical systems

    SciTech Connect

    Dorfman, B.F. |; Asoka-Kumar, P.; Zhu, Q.; Pollak, F.H.; Wan, J.Z.

    1996-01-01

    A new form of sp{sup 3}/sp{sup 2} carbon has been fabricated which exhibits a large number of valuable properties. This material combines low density ({le} 1.65 g/cm{sup 3}), low stress ({le} 0.05 GPa), low thermal expansion(1.6 x 10{sup {minus}6} K{sup {minus}1}) with high hardness ({approximately} 30 GPa), modulus ({approximately} 200 GPa), cracking threshold ({ge} 3 N), fracture toughness ({ge} 10 MPa-m{sup 1/2}), long-term thermal stability ({ge} 450 C in air and {ge} 600 C without oxygen), extremely high thermal shock resistance, excellent interface and adhesion to silicon, metals, and ceramics and an absolute resistance to the silicon etching acids. Mot of its properties are actually constant up to 700 K. The material combines a basically amorphous structure with one-axis anisotropy and a graphite-like layered arrangement with a length scale of the modulation about 14 {angstrom}. The authors refer to this quasi-amorphous material as QUASAM. This paper describes QUASAM synthesis conditions, growth front planarity and material characterization with high-resolution x-ray diffraction, positron annihilation spectroscopy, atomic force microscopy and micro-Raman spectroscopy. In addition the mechanical and thermal examination of QUASAM and QUASAM/Si will be presented in terms of micro-electro-mechanical systems (MEMS) and the technology prospective requirements of MEMS.

  3. Genetic Algorithm for the Design of Electro-Mechanical Sigma Delta Modulator MEMS Sensors

    PubMed Central

    Wilcock, Reuben; Kraft, Michael

    2011-01-01

    This paper describes a novel design methodology using non-linear models for complex closed loop electro-mechanical sigma-delta modulators (EMΣΔM) that is based on genetic algorithms and statistical variation analysis. The proposed methodology is capable of quickly and efficiently designing high performance, high order, closed loop, near-optimal systems that are robust to sensor fabrication tolerances and electronic component variation. The use of full non-linear system models allows significant higher order non-ideal effects to be taken into account, improving accuracy and confidence in the results. To demonstrate the effectiveness of the approach, two design examples are presented including a 5th order low-pass EMΣΔM for a MEMS accelerometer, and a 6th order band-pass EMΣΔM for the sense mode of a MEMS gyroscope. Each example was designed using the system in less than one day, with very little manual intervention. The strength of the approach is verified by SNR performances of 109.2 dB and 92.4 dB for the low-pass and band-pass system respectively, coupled with excellent immunities to fabrication tolerances and parameter mismatch. PMID:22163691

  4. Electro-Mechanical Testing of Conductive Materials Used in Flexible Electronics

    NASA Astrophysics Data System (ADS)

    Cordill, Megan; Glushko, Oleksandr; Putz, Barbara

    2016-02-01

    The use of flexible electronics has increased in recent years. In order to have robust and long lasting flexible displays and sensors, the combined electro-mechanical behavior needs to be assessed. The most common method to determine electrical and mechanical behavior of conductive thin films used in flexible electronics is the fragmentation test, or uniaxial tensile straining of the film and substrate. When performed in situ fracture and deformation behavior can be determined. The use of in situ electrical resistance measurements can be informative about the crack onset strain of brittle layers, such as transparent conductors, or the stretchability of metal interconnects. The combination of in situ electrical measurements with in situ X-ray or confocal laser scanning microscopy can provide even more information about the failure mechanisms of the material systems. Lattice strains and stresses can be measured with X-rays, while cracking and buckle delaminations can be studied with confocal laser scanning microscopy. These new combinations of in situ methods will be discussed as well as methods to quantify interfacial properties of conductive thin films on polymer substrates. The combined techniques provide valuable correlated electrical and mechanical data needed to understand failure mechanisms in flexible devices.

  5. Micromachining of an SU-8 flapping-wing flying micro-electro-mechanical system

    NASA Astrophysics Data System (ADS)

    Dargent, T.; Bao, X. Q.; Grondel, S.; Brun, G. Le; Paquet, J. B.; Soyer, C.; Cattan, E.

    2009-08-01

    This paper presents a feasibility step in the development of an ultra-small biomimetic flying machine. Advanced engineering technologies available for applications such as the micro-electro-mechanical system (MEMS) technologies are used. To achieve this goal, a flapping-wing flying MEMS concept and design inspired from insects is first described. Actuators and an actuation way for the control over the wing kinematics are proposed. The initial concepts are subsequently analyzed and presented using multi-body and finite element models. An overview of SU-8 photoresist structures and their functions in the future micro-robot insect is then presented. Consequently, micromachining enables the implementation of a flying MEMS. It is also demonstrated that the structure can be made at insect sizes and actuated at low power inputs. Moreover, the flapping frequency obtained is within the flapping frequency range of wings of many common insects of millimetric dimensions. Such prototypes are of interest as tools to artificially recreate and study insect flight with characteristics, similar to those of insects, that are able to produce lift and hover. Finally, if a micro-battery, wireless receivers, microcontrollers, sensors and actuators can all be fitted onto chips only a few millimeters square, with a mass in the order of milligrams, then we believe that an insect-size flying MEMS can be realized. All these requirements can now be achieved due to advanced engineering methods.

  6. Use of the electro-mechanical impedance method for the assessment of dental implant stability

    NASA Astrophysics Data System (ADS)

    Rizzo, Piervincenzo; Boemio, Giovanni; de Nardo, Luigi

    2011-04-01

    The robustness and reliability of the Electro-Mechanical Impedance (EMI) method to assess dental prostheses stability is presented. The study aim at addressing an increasing need in the biomedical area where robust, reliable, and non-invasive methods to assess the bone-interface of dental and orthopedic implants are increasingly demanded for clinical diagnosis and direct prognosis. In this study two different dental screws were entrenched in polyurethane foams and immersed in a solution of nitric acid to allow material degradation, inversely simulating a bone-healing process. This process was monitored by bonding a Piezoceramic Transducer (PZT) to the implant and measuring the admittance of the PZT over time. To simulate healing, a second set of experiments was conducted. It consisted of placing four dental screws inside a joint compound specimen and observing the setting of the fresh compound allocated in the alveolus containing each implant. In all cases it was found that the PZT's conductance and the statistical features associated with the analysis of the admittance signatures were sensitive to the degradation or the setting process.

  7. A noise level prediction method based on electro-mechanical frequency response function for capacitors.

    PubMed

    Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

    2013-01-01

    The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective. PMID:24349105

  8. System and method of active vibration control for an electro-mechanically cooled device

    DOEpatents

    Lavietes, Anthony D.; Mauger, Joseph; Anderson, Eric H.

    2000-01-01

    A system and method of active vibration control of an electro-mechanically cooled device is disclosed. A cryogenic cooling system is located within an environment. The cooling system is characterized by a vibration transfer function, which requires vibration transfer function coefficients. A vibration controller generates the vibration transfer function coefficients in response to various triggering events. The environments may differ by mounting apparatus, by proximity to vibration generating devices, or by temperature. The triggering event may be powering on the cooling system, reaching an operating temperature, or a reset action. A counterbalance responds to a drive signal generated by the vibration controller, based on the vibration signal and the vibration transfer function, which adjusts vibrations. The method first places a cryogenic cooling system within a first environment and then generates a first set of vibration transfer function coefficients, for a vibration transfer function of the cooling system. Next, the cryogenic cooling system is placed within a second environment and a second set of vibration transfer function coefficients are generated. Then, a counterbalance is driven, based on the vibration transfer function, to reduce vibrations received by a vibration sensitive element.

  9. Wireless biomedical signal monitoring device on wheelchair using noncontact electro-mechanical film sensor.

    PubMed

    Kim, Jong-Myoung; Hong, Joo-Hyun; Cho, Myeong-Chan; Cha, Eun-Jong; Lee, Tae-Soo

    2007-01-01

    The present study purposed to measure the BCG (Ballistocardiogram) of subjects on a wheelchair using a noncontact electro-mechanical film sensor (EMFi sensor) and detect the respiratory rate from BCG in real-time while the subjects are moving. In order to measure wirelessly the BCG of subjects moving on a wheelchair, we made a seat-type noncontact EMFi sensor and developed a transmitter and a receiver using Zigbee wireless RF communication technology. The sensor is embedded with a 3-axis accelerometer to remove the noise of wheelchair vibration from BCG signal. Signal obtained from each sensor goes through the A/D converter and is recorded in the SD (Secure Digital) card in PDA (Personal Digital Assistance) with a receiving part. We also developed a PC (Personal Computer) data analysis program, analyzed data recorded in the SD card using the program, and presented the results in graph. Lastly, this study demonstrated that a warning message can be sent from PDA to the remote server via a CDMA (Code Division Multiple Access) network in case the person on wheelchair falls in emergency. Our experiment was carried out with healthy male and female adults in their 20s who volunteered to help this research. The results of analyzing collected data will show that the respiratory rate can be measured in real-time on a moving wheelchair. PMID:18002021

  10. Analysis of the "Push-pull" Capacitance Bridge Circuit for Comb-Drive Micro-electro-mechanical Oscillators

    NASA Astrophysics Data System (ADS)

    Zheng, P.; Jiang, W. G.; Barquist, C. S.; Lee, Y.; Chan, H. B.

    2016-05-01

    We have developed an improved actuation/detection scheme for a comb-drive micro-electro-mechanical oscillator as a probe to study quantum fluids. This symmetric scheme has many advantages over the asymmetric scheme used previously. In this report, we provide a full description and analysis of the method so that researchers interested can readily implement the method in their experiments involving similar devices.

  11. Superharmonic resonances in a two-dimensional non-linear photonic-crystal nano-electro-mechanical oscillator

    NASA Astrophysics Data System (ADS)

    Chowdhury, A.; Yeo, I.; Tsvirkun, V.; Raineri, F.; Beaudoin, G.; Sagnes, I.; Raj, R.; Robert-Philip, I.; Braive, R.

    2016-04-01

    We investigate the non-linear mechanical dynamics of a nano-optomechanical mirror formed by a suspended membrane pierced by a photonic crystal. By applying to the mirror a periodic electrostatic force induced by interdigitated electrodes integrated below the membrane, we evidence superharmonic resonances of our nano-electro-mechanical system; the constant phase shift of the oscillator across the resonance tongues is observed on the onset of principal harmonic and subharmonic excitation regimes.

  12. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOEpatents

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  13. Robust design optimization with an uncertain model of a nonlinear vibro-impact electro-mechanical system

    NASA Astrophysics Data System (ADS)

    Lima, Roberta; Soize, Christian; Sampaio, Rubens

    2015-06-01

    In this paper, the robust design with an uncertain model of a vibro-impact electro-mechanical system is done. The electro-mechanical system is composed of a cart, whose motion is excited by a DC motor (motor with continuous current), and an embarked hammer into this cart. The hammer is connected to the cart by a nonlinear spring component and by a linear damper, so that a relative motion exists between them. A linear flexible barrier, placed outside of the cart, constrains the hammer movements. Due to the relative movement between the hammer and the barrier, impacts can occur between these two elements. The developed model of the system takes into account the influence of the DC motor in the dynamic behavior of the system. Some system parameters are uncertain, such as the stiffness and the damping coefficients of the flexible barrier. The objective of the paper is to perform an optimization of this electro-mechanical system with respect to design parameters (spring component, and barrier g) in order to maximize the impact power under the constraint that the electric power consumed by the DC motor is lower than a maximum value. This optimization is formulated in the framework of robust design due to the presence of uncertainties in the model. The set of nonlinear equations are presented, and an adapted time domain solver is developed. The stochastic nonlinear constrained design optimization problem is solved for different levels of uncertainties, and also for the deterministic case.

  14. Bioenzymatic detection of troponin C using micro-opto-electro-mechanical systems.

    PubMed

    Amritsar, Jeetender; Stiharu, Ion; Packirisamy, Muthukumaran

    2006-01-01

    Diagnosis and monitoring of critical diseases such as acute myocardial infarction (AMI) require a quantitative analysis of biological molecules. A high-throughput identification of these biological molecules can be generated by using micro-electro-mechanical systems (MEMS) structures like simple cantilever beams, which respond to the intermolecular forces resulting from binding these molecules. Biochemical markers like troponin C are considered the primary markers for myocardial injury and have generated considerable interest. A 26-residue lytic membrane protein of bee venom melittin (ME) is chosen to interact with rabbit skeletal muscle troponin C (TnC) on the surface of the cantilever beams. An optical beam deflection method is employed to identify the enzymatic reaction on the surface of the cantilever due to these proteins. Identification of these proteins is also done using fluorescence spectroscopy (FS) to compliment the optical monitored deflection method. A second set of proteins like horse radish peroxide (HRP) and hydrogen peroxide (H2O2) are applied to atomic force microscopy (AFM) cantilever beams to study their behavior under the enzymatic reactions of proteins. Identification of these proteins is done using Fourier transform infrared spectroscopy (FTIR). An analytical model of the cantilever beam is developed, and its mode shapes are studied by employing orthogonal polynomials in the classic Rayleigh-Ritz method. The surface stress caused by the enzymatic reaction of the proteins that leads to pure bending on the top surface of the cantilever is evaluated. The information provided by the experimental and analytical modeling reported in this work will be useful in the development of a portable biosensor for the detection of AMI. PMID:16674185

  15. Design and development of microswitches for micro-electro-mechanical relay matrices

    NASA Astrophysics Data System (ADS)

    Phipps, Mark W.

    1995-06-01

    Many different micro-electro-mechanical (MEM) switches were designed in the Multi-User MEM's Processes (MUMP's) and deep x-ray lithography and electroforming (LIGA) processes. The switches were composed of actuators that operated based upon either electrostatic forces or thermal forces. A thermally activated beam flexure actuator that operated based upon differential heating was used extensively. This actuator, which was fabricated in the MUMP's process, was able to deflect up to 12 microns with a total input power of less than 25 mW. The thermal resistance, which was needed to model this actuator, was determined from a material constant, 1.9 +/- 0.08 m(exp 1.5) C/W for the POLY1 layer in MUMP's and 7.4 +/- 0.88 m(exp 1.5) C/W for the POLY2 layer in MUMP's, which was extracted from 1020 actuator test cases. A switch using a hinge mechanism that allowed metal-to-metal contacts to be formed was also developed in the MUMP's process. The contact resistance of these devices was determined to be 9.91 +/- 6.22 kohms. An electrostatically deformable microbridge structure (2 microns thick, 40 microns wide, 332 microns long, and with a capacitive gap of 2 microns) was also employed as a switch. A voltage of 53.3 volts applied between the microbridge and two drive electrodes was able to force the center of the microbridge to touch a sense electrode. The observed contact resistance for this connection was 300 +/- 89.7 ohms.

  16. Bioenzymatic detection of troponin C using micro-opto-electro-mechanical systems

    NASA Astrophysics Data System (ADS)

    Jeetender, Amritsar; Stiharu, Ion G.; Muthukumaran, Packirisamy

    2006-03-01

    Diagnosis and monitoring of critical diseases such as acute myocardial infarction (AMI) require a quantitative analysis of biological molecules. A high-throughput identification of these biological molecules can be generated by using micro-electro-mechanical systems (MEMS) structures like simple cantilever beams, which respond to the intermolecular forces resulting from binding these molecules. Biochemical markers like troponin C are considered the primary markers for myocardial injury and have generated considerable interest. A 26-residue lytic membrane protein of bee venom melittin (ME) is chosen to interact with rabbit skeletal muscle troponin C (TnC) on the surface of the cantilever beams. An optical beam deflection method is employed to identify the enzymatic reaction on the surface of the cantilever due to these proteins. Identification of these proteins is also done using fluorescence spectroscopy (FS) to compliment the optical monitored deflection method. A second set of proteins like horse raddish peroxide (HRP) and hydrogen peroxide (H2O2) are applied to atomic force microscopy (AFM) cantilever beams to study their behavior under the enzymatic reactions of proteins. Identification of these proteins is done using Fourier transform infrared spectroscopy (FTIR). An analytical model of the cantilever beam is developed, and its mode shapes are studied by employing orthogonal polynomials in the classic Rayleigh-Ritz method. The surface stress caused by the enzymatic reaction of the proteins that leads to pure bending on the top surface of the cantilever is evaluated. The information provided by the experimental and analytical modeling reported in this work will be useful in the development of a portable biosensor for the detection of AMI.

  17. MEMS (Micro-Electro-Mechanical Systems) for Automotive and Consumer Electronics

    NASA Astrophysics Data System (ADS)

    Marek, Jiri; Gómez, Udo-Martin

    MEMS sensors gained over the last two decades an impressive width of applications: (a) ESP: A car is skidding and stabilizes itself without driver intervention (b) Free-fall detection: A laptop falls to the floor and protects the hard drive by parking the read/write drive head automatically before impact. (c) Airbag: An airbag fires before the driver/occupant involved in an impending automotive crash impacts the steering wheel, thereby significantly reducing physical injury risk. MEMS sensors are sensing the environmental conditions and are giving input to electronic control systems. These crucial MEMS sensors are making system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible. Important prerequisites for the success of sensors are their size, functionality, power consumption, and costs. This technical progress in sensor development is realized by micro-machining. The development of these processes was the breakthrough to industrial mass-production for micro-electro-mechanical systems (MEMS). Besides leading-edge micromechanical processes, innovative and robust ASIC designs, thorough simulations of the electrical and mechanical behaviour, a deep understanding of the interactions (mainly over temperature and lifetime) of the package and the mechanical structures are needed. This was achieved over the last 20 years by intense and successful development activities combined with the experience of volume production of billions of sensors. This chapter gives an overview of current MEMS technology, its applications and the market share. The MEMS processes are described, and the challenges of MEMS, compared to standard IC fabrication, are discussed. The evolution of MEMS requirements is presented, and a short survey of MEMS applications is shown. Concepts of newest inertial sensors for ESP-systems are given with an emphasis on the design concepts of the sensing element and the evaluation circuit for achieving

  18. Osmotic regulation of seamless tube growth.

    PubMed

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S

    2013-02-01

    Most organs are composed of tubes of differing cellular architectures, including intracellular 'seamless' tubes. Two studies examining the morphogenesis of the seamless tubes formed by the excretory canal cell in Caenorhabditis elegans reveal a previously unappreciated role for osmoregulation of tubulogenesis: hyperosmotic shock recruits canalicular vesicles to the lumenal membrane to promote seamless tube growth. PMID:23377027

  19. Parametric resonance voltage response of electrostatically actuated Micro-Electro-Mechanical Systems cantilever resonators

    NASA Astrophysics Data System (ADS)

    Caruntu, Dumitru I.; Martinez, Israel; W. Knecht, Martin

    2016-02-01

    This paper investigates the parametric resonance voltage response of nonlinear parametrically actuated Micro-Electro-Mechanical Systems (MEMS) cantilever resonators. A soft AC voltage of frequency near natural frequency is applied between the resonator and a parallel ground plate. This produces an electrostatic force that leads the structure into parametric resonance. The model consists of an Euler-Bernoulli thin cantilever under the actuation of electrostatic force to include fringe effect, and damping force. Two methods of investigation are used, namely the Method of Multiple Scales (MMS) and Reduced Order Model (ROM) method. ROM convergence of the voltage response and the limitation of MMS to small to moderate amplitudes with respect to the gap (gap-amplitudes) are reported. MMS predicts accurately both Hopf supercritical and supercritical bifurcation voltages. However, MMS overestimates the large gap-amplitudes of the resonator, and. misses completely or overestimates the saddle-node bifurcation occurring at large gap-amplitudes. ROM produces valid results for small and/or large gap-amplitudes for a sufficient number of terms (vibration modes). As the voltage is swept up at constant frequency, the resonator maintains zero amplitude until reaches the subcritical Hopf bifurcation voltage where it loses stability and jumps up to large gap-amplitudes, next the gap-amplitude decreases until it reaches the supercritical Hopf bifurcation point, and after that the gap-amplitude remains zero, for the voltage range considered in this work. As the voltage is swept down at constant frequency, the zero gap-amplitude of the resonator starts increasing continuously after reaching the supercritical Hopf bifurcation voltage until it reaches the saddle-node bifurcation voltage when a sudden jump to zero gap-amplitude occurs. Effects of frequency, damping and fringe parameters on the voltage response show that (1) the supercritical Hopf bifurcation is shifted to lower voltage

  20. Understanding the quasi-static thermo-electro-mechanical response of piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Ganley, Jeffrey Mark

    2007-12-01

    Piezoelectricity describes the behavior of a class of materials which exhibit a relationship between mechanical strain and electrical field. Piezoelectric materials can be crystals (e.g. quartz), ceramic (e.g. lead-zirconate-titanate---PZT---the primary focus of the present research), or polymers (e.g. polyvinylidine-fluoride - PVDF). Piezopolymers and piezoceramics offer a significant improvement in piezoelectric properties over naturally occurring piezoelectrics like quartz. In the last five years, research in piezoelectrics has begun to change focus from the more traditional sensor/actuator applications to utilizing piezoelectric materials in energy harvesting applications. The present research will explore the very low frequency response of piezoelectrics, including several energy harvesting applications, as well as the interactions between thermal, mechanical and electrical energy in a thermally driven piezoelectric energy generation system. In Chapter 1, the history of piezoelectric research and development is given, along with an overview of piezoelectricity for those readers who are not familiar with the topic. In Chapter 2, current investigations in piezoelectric energy harvesting research are summarized. The present research, namely understanding the quasi-static thermo-electro-mechanical response of piezoelectric materials is also summarized. In addition, two applications: thermal management in a satellite and energy harvesting from a vibrating highway bridge are detailed as motivators for the present research. Chapter 3 gives a summary of the relevant piezoelectric theory. In addition, electrical circuit theory and thermodynamic heat capacity/heat energy considerations required to complete the present research are given. Chapter 4 provides a summary of the experimental testing completed during the course of the present research. Significant testing, including determination of the PZT/Aluminum substrate sample time constants, thermal calibration testing

  1. Development of high resolution eddy current imaging using an electro-mechanical sensor

    NASA Astrophysics Data System (ADS)

    Cherry, M. R.; Sathish, S.; Welter, J.; Reibel, R.; Blodgett, M. P.

    2012-05-01

    Typical eddy current probes are based on measuring the impedance change of a coil excited by an AC current when the coil is placed above a conductive sample. These types of probes are limited in spatial resolution to the dimensions of the coil, and coil diameter is limited by operating frequency. Because of this, the highest resolution available with these probes is on the order of 100 um. While detecting the impedance change of the probe has limited special resolution, various methods of detecting the change in magnetic field in and around the coil have been shown to improve the resolution of a standard coil. These methods have improved the resolution in eddy current imaging to 25 nm. To date, the resolutions achievable by modern eddy current technology have failed to encompass the 100nm - 100 um range, which would be ideal for microstructure characterization of conductive materials. In this paper, a new probe, called the electro-mechanical eddy current sensor (EMECS), is presented that is based on the electromechanical design to fill this resolution gap. The new probe is designed and developed with a sharpened magnetic tip attached to the membrane of an electret microphone. The magnet is actuated by an external coil with a low current AC voltage. The motion of the magnet produces eddy currents in a conductive sample, which then result in a damping force on the magnet. The results of the experimental measurements demonstrate that this probe has spatial resolution that is much higher compared with the measurements using the external excitation coil only. The role of competing eddy currents produced by the motion of the magnet and the excitation coil in the material are examined with numerical analysis and the effects of the eddy currents from the excitation coil are shown to be negligible. A governing equation for the probe is presented that treats the magnet as a magnetic dipole and uses the eddy current forces as a damping term in the equation of motion for the

  2. Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

    NASA Astrophysics Data System (ADS)

    Wallace, Brian D.

    A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

  3. Design and fabrication of a flexible MEMS-based electro-mechanical sensor array for breast cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Pandya, Hardik J.; Park, Kihan; Desai, Jaydev P.

    2015-07-01

    The use of flexible micro-electro-mechanical systems (MEMS)-based devices provides a unique opportunity in bio-medical robotics such as the characterization of normal and malignant tissues. This paper reports on the design and development of a flexible MEMS-based sensor array integrating mechanical and electrical sensors on the same platform to enable the study of the change in electro-mechanical properties of benign and cancerous breast tissues. In this work, we present the analysis of the electrical characterization of the tissue specimens and also demonstrate the feasibility of using the sensor for the mechanical characterization of tissue specimens. Eight strain gauges acting as mechanical sensors were fabricated using poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) conducting polymer on poly(dimethylsiloxane) (PDMS) as the substrate material. Eight electrical sensors were fabricated using SU-8 pillars on gold (Au) pads which were patterned on the strain gauges separated by a thin insulator (SiO2 1.0 μm). These pillars were coated with gold to make them conducting. The electro-mechanical sensors are integrated on the same substrate. The sensor array covers a 180 μm  ×  180 μm area and the size of the complete device is 20 mm in diameter. The diameter of each breast tissue core used in the present study was 1 mm and the thickness was 8 μm. The region of interest was 200 μm  ×  200 μm. A microindentation technique was used to characterize the mechanical properties of the breast tissues. The sensor is integrated with conducting SU-8 pillars to study the electrical property of the tissue. Through electro-mechanical characterization studies using this MEMS-based sensor, we were able to measure the accuracy of the fabricated device and ascertain the difference between benign and cancers breast tissue specimens.

  4. Seamless multiresolution isosurfaces using wavelets

    SciTech Connect

    Udeshi, T.; Hudson, R.; Papka, M. E.

    2000-04-11

    Data sets that are being produced by today's simulations, such as the ones generated by DOE's ASCI program, are too large for real-time exploration and visualization. Therefore, new methods of visualizing these data sets need to be investigated. The authors present a method that combines isosurface representations of different resolutions into a seamless solution, virtually free of cracks and overlaps. The solution combines existing isosurface generation algorithms and wavelet theory to produce a real-time solution to multiple-resolution isosurfaces.

  5. Seamless Resource-Adaptive Navigation

    NASA Astrophysics Data System (ADS)

    Schwartz, Tim; Stahl, Christoph; Baus, Jörg; Wahlster, Wolfgang

    Research in the project RENA (REsource-Adapative NAvigation) together with DFKI GmbH, BMW Research and Technology AG, and Eyeled GmbH has been concerned with the conceptual and methodological foundations and the design of a resource-adaptive platform for seamless outdoor and indoor navigation that can serve as a basis for product development by the companies in the RENA consortium. Future in-car assistance systems will have a user interface, which adapts to the driveŕs current exposure caused by the actual traffic situation.

  6. Micro-optical design of a three-dimensional microlens scanner for vertically integrated micro-opto-electro-mechanical systems.

    PubMed

    Baranski, Maciej; Bargiel, Sylwester; Passilly, Nicolas; Gorecki, Christophe; Jia, Chenping; Frömel, Jörg; Wiemer, Maik

    2015-08-01

    This paper presents the optical design of a miniature 3D scanning system, which is fully compatible with the vertical integration technology of micro-opto-electro-mechanical systems (MOEMS). The constraints related to this integration strategy are considered, resulting in a simple three-element micro-optical setup based on an afocal scanning microlens doublet and a focusing microlens, which is tolerant to axial position inaccuracy. The 3D scanning is achieved by axial and lateral displacement of microlenses of the scanning doublet, realized by micro-electro-mechanical systems microactuators (the transmission scanning approach). Optical scanning performance of the system is determined analytically by use of the extended ray transfer matrix method, leading to two different optical configurations, relying either on a ball lens or plano-convex microlenses. The presented system is aimed to be a core component of miniature MOEMS-based optical devices, which require a 3D optical scanning function, e.g., miniature imaging systems (confocal or optical coherence microscopes) or optical tweezers. PMID:26368111

  7. Microcontroller Based Proportional Derivative Plus Conditional Integral Controller for Electro-Mechanical Dual Acting Pulley Continuously Variable Transmission Ratio Control

    NASA Astrophysics Data System (ADS)

    Budianto, A.; Tawi, K. B.; Hussein, M.; Supriyo, B.; Ariyono, S.; Che Kob, M. S.; Ezlamy Zulkifli, Mohd; K, Khairuldean A.; Daraoh, Aishah

    2012-09-01

    Electro-Mechanical Dual Acting Pulley (EMDAP) Continuously Variable Transmission (CVT) is a transmission utilized by electro-mechanical actuated system. It has a potential to reduce energy consumption because it only needs power during changing CVT ratio and no power is needed to maintain CVT ratio due to self lock mechanism design. This paper proposed simple proportional derivative plus conditional integral (PDCI) controller to control EMDAP CVT ratio which can be simply implemented on a microcontroller. This proposed controller used Astrom-Hagglund method and Ziegler-Nichols formula to tune PDCI gain. The Proportional Derivative controller is directly activated from the start but Integral controller is only activated when the error value reaches error value setting point. Simulation using Matlab/Simulink software was conducted to evaluate PDCI system performance. The simulation results showed PDCI controller has ability to perform maximum overshoot 0.1%, 0.001 steady state error and 0.5s settling time. For clamping condition, settling time is about 11.46s during changing ratio from 2.0 to 0.7, while for release condition, settling time is about 8.33s during changing ratio from 0.7 to 2.0.

  8. Chaos control of the micro-electro-mechanical resonator by using adaptive dynamic surface technology with extended state observer

    NASA Astrophysics Data System (ADS)

    Luo, Shaohua; Sun, Quanping; Cheng, Wei

    2016-04-01

    This paper addresses chaos control of the micro-electro- mechanical resonator by using adaptive dynamic surface technology with extended state observer. To reveal the mechanism of the micro- electro-mechanical resonator, the phase diagrams and corresponding time histories are given to research the nonlinear dynamics and chaotic behavior, and Homoclinic and heteroclinic chaos which relate closely with the appearance of chaos are presented based on the potential function. To eliminate the effect of chaos, an adaptive dynamic surface control scheme with extended state observer is designed to convert random motion into regular motion without precise system model parameters and measured variables. Putting tracking differentiator into chaos controller solves the `explosion of complexity' of backstepping and poor precision of the first-order filters. Meanwhile, to obtain high performance, a neural network with adaptive law is employed to approximate unknown nonlinear function in the process of controller design. The boundedness of all the signals of the closed-loop system is proved in theoretical analysis. Finally, numerical simulations are executed and extensive results illustrate effectiveness and robustness of the proposed scheme.

  9. COMPUTATIONAL CHALLENGES IN BUILDING MULTI-SCALE AND MULTI-PHYSICS MODELS OF CARDIAC ELECTRO-MECHANICS

    PubMed Central

    Plank, G; Prassl, AJ; Augustin, C

    2014-01-01

    Despite the evident multiphysics nature of the heart – it is an electrically controlled mechanical pump – most modeling studies considered electrophysiology and mechanics in isolation. In no small part, this is due to the formidable modeling challenges involved in building strongly coupled anatomically accurate and biophyically detailed multi-scale multi-physics models of cardiac electro-mechanics. Among the main challenges are the selection of model components and their adjustments to achieve integration into a consistent organ-scale model, dealing with technical difficulties such as the exchange of data between electro-physiological and mechanical model, particularly when using different spatio-temporal grids for discretization, and, finally, the implementation of advanced numerical techniques to deal with the substantial computational. In this study we report on progress made in developing a novel modeling framework suited to tackle these challenges. PMID:24043050

  10. An integrated electro-mechanical model of motor-gear units—Applications to tooth fault detection by electric measurements

    NASA Astrophysics Data System (ADS)

    Feki, N.; Clerc, G.; Velex, Ph.

    2012-05-01

    Fault diagnosis in geared transmissions is traditionally based on vibration monitoring but, in a number of cases, sensor implementation and signal transfer from rotary to stationary parts can cause problems. This paper presents an original integrated electro-mechanical model aimed at testing the possibility and the interest of tooth fault detection based on electric measurements on the motor stator. The motor is simulated using Kron's transformation while the mechanical transmission is accounted for by a lumped parameter model. Tooth defects are assimilated to distributions of initial separations between the mating flanks whose positions and shapes are controlled. A unique non-linear parametrically excited differential system is obtained, which provides direct access to both the electrical and mechanical variables. A number of results are presented, which illustrate the possibility of tooth fault detection by stator current measurements with regard to the position and dimensions of the defect.

  11. Out-of-plane nano-electro-mechanical tuning of the Fano resonance in photonic crystal split-beam nanocavity

    NASA Astrophysics Data System (ADS)

    Lin, Tong; Zhang, Xingwang; Zou, Yongchao; Chau, Fook Siong; Deng, Jie; Zhou, Guangya

    2015-10-01

    We propose and experimentally demonstrate the use of Fano resonance as a means to improve the Quality factor of photonic crystal split-beam nanocavities. The Fano resonance is triggered by the interference between the second-order quasi-transverse electric resonant mode and the leaky high-order quasi-transverse electric propagation mode of the optimized photonic crystal split-beam nanocavity. Compared with a similar photonic crystal split-beam nanocavity without asymmetric Fano lineshape, the Q-factor is increased up to 3-fold: from 1.99 ×104 to 5.95 ×104 . Additionally, out-of-plane tuning of the Fano resonance is investigated by means of a Nano-Electro-Mechanical Systems based actuator. The maximum centre wavelength shift of the Fano resonance reached 116.69 pm, which is more than 4.5 times the original quasi-Full Width at Half Magnitude.

  12. Bias Dependence of Gallium Nitride Micro-Electro-Mechanical Systems Actuation Using a Two-Dimensional Electron Gas

    NASA Astrophysics Data System (ADS)

    Amar, Achraf Ben; Faucher, Marc; Grimbert, Bertrand; Cordier, Yvon; Fran\\{c}ois, Marc; Tilmant, Pascal; Werquin, Matthieu; Zhang, Victor; Ducatteau, Damien; Gaquière, Christophe; Buchaillot, Lionel; Théron, Didier

    2012-06-01

    The piezoelectric actuation of a micro-electro-mechanical system (MEMS) resonator based on an AlGaN/GaN heterostructure is studied under various bias conditions. Using an actuator electrode that is also a transistor gate, we correlate the mechanical behaviour to the two-dimensional electron gas (2DEG) presence. The measured amplitude of the actuated resonator is maximum at moderate negative biases and drops near the pinch-off voltage in concordance with the 2DEG becoming depleted. Below the pinch-off voltage, residual actuation is still present, which is attributed to a more complex electric field pattern supported by quantitative modelling. The results confirm that epitaxial AlGaN barriers are fully adapted to the piezoelectric actuation of MEMS.

  13. An electro-mechanically coupled model for the dynamic behavior of a dielectric electro-active polymer actuator

    NASA Astrophysics Data System (ADS)

    Hodgins, M.; Rizzello, G.; Naso, D.; York, A.; Seelecke, S.

    2014-10-01

    Dielectric electro-active polymer (DEAP) technology holds promise for enabling lightweight, energy efficient, and scalable actuators. The circular DEAP actuator configuration (also known as cone or diaphragm actuator) in particular shows potential in applications such as pumps, valves, micro-positioners and loudspeakers. For a quantitative prediction of the actuator behavior as well as for design optimization tasks, material models which can reproduce the coupled electromechanical behavior inherent to these actuators are necessary. This paper presents a non-linear viscoelastic model based on an electro-mechanical Ogden free energy expression for the DEAP. The DEAP model is coupled with a spring/mass system to study the dynamic performance of such a representative system from static behavior to 50 Hz. The system is identified and validated by several different experiments.

  14. An Investigation into the Response of a Micro Electro Mechanical Compound Pivot Mirror Using Finite Element Modeling

    SciTech Connect

    GASS, FAWN R.; DOHNER, JEFFREY L.

    2002-01-01

    This report is a presentation of modeling and simulation work for analyzing three designs of Micro Electro Mechanical (MEM) Compound Pivot Mirrors (CPM). These CPMs were made at Sandia National Laboratories using the SUMMiT{trademark} process. At 75 volts and above, initial experimental analysis of fabricated mirrors showed tilt angles of up to 7.5 degrees for one design, and 5 degrees for the other two. Nevertheless, geometric design models predicted higher tilt angles. Therefore, a detailed study was conducted to explain why lower tilt angles occurred and if design modifications could be made to produce higher tilt angles at lower voltages. This study showed that the spring stiffnesses of the CPMs were too great to allow for desired levels of rotation at lower levels of voltage. To produce these lower stiffnesses, a redesign is needed.

  15. Micro-electro-mechanical systems/near-infrared validation of different sampling modes and sample sets coupled with multiple models.

    PubMed

    Wu, Zhisheng; Shi, Xinyuan; Wan, Guang; Xu, Manfei; Zhan, Xueyan; Qiao, Yanjiang

    2015-01-01

    The aim of the present study was to demonstrate the reliability of micro-electro-mechanical systems/near-infrared technology by investigating analytical models of two modes of sampling (integrating sphere and fiber optic probe modes) and different sample sets. Baicalin in Yinhuang tablets was used as an example, and the experimental procedure included the optimization of spectral pretreatments, selection of wavelength regions using interval partial least squares, moving window partial least squares, and validation of the method using an accuracy profile. The results demonstrated that models that use the integrating sphere mode are better than those that use fiber optic probe modes. Spectra that use fiber optic probe modes tend to be more susceptible to interference information because the intensity of the incident light on a fiber optic probe mode is significantly weaker than that on an integrating sphere mode. According to the test set validation result of the method parameters, such as accuracy, precision, risk, and linearity, the selection of variables was found to make no significant difference to the performance of the full spectral model. The performance of the models whose sample sets ranged widely in concentration (i.e., 1-4 %) was found to be better than that of models whose samples had relatively narrow ranges (i.e., 1-2 %). The establishment and validation of this method can be used to clarify the analytical guideline in Chinese herbal medicine about two sampling modes and different sample sets in the micro-electro-mechanical systems/near-infrared technique. PMID:25626144

  16. A seamless ubiquitous telehealthcare tunnel.

    PubMed

    Cheng, Po-Hsun; Lin, Bor-Shing; Yu, Chu; Hu, Shun-Hsiang; Chen, Sao-Jie

    2013-08-01

    Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP) is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields. PMID:23917812

  17. A Seamless Ubiquitous Telehealthcare Tunnel

    PubMed Central

    Cheng, Po-Hsun; Lin, Bor-Shing; Yu, Chu; Hu, Shun-Hsiang; Chen, Sao-Jie

    2013-01-01

    Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP) is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields. PMID:23917812

  18. EXPERIMENTATION IN THE DEVELOPMENT OF MORE EFFECTIVE METHODS OF TEACHING FOREIGN LANGUAGES BY MAKING EXTENSIVE USE OF ELECTRO-MECHANICAL AIDS.

    ERIC Educational Resources Information Center

    LEWIS, EARL N.

    AN EXPERIMENT WAS DESIGNED TO TEST THE HYPOTHESIS THAT PROPER USE OF ELECTRO-MECHANICAL AIDS CAN RELIEVE THE TEACHER OF A GREAT DEAL OF THE ROUTINE WORK OF TEACHING FOREIGN LANGUAGES. HE WOULD THUS BE ALLOWED TO EXTEND HIMSELF EITHER QUANTITATIVELY OR QUALITATIVELY IN HIS WORK. THIS EXPERIMENT USES THE QUALITATIVE APPROACH. THREE GROUPS OF…

  19. Smart materials fabrication and materials for micro-electro-mechanical systems; Symposium Proceedings, San Francisco, CA, Apr. 28-30, 1992

    NASA Technical Reports Server (NTRS)

    Jardine, A. Peter (Editor); Johnson, George C. (Editor); Crowson, Andrew (Editor); Allen, Mark (Editor)

    1992-01-01

    A conference on the rapidly developing fields of `smart materials' and micro-electro-mechanical systems produced papers in the areas of fabrication and characterization of ferroelectric thin films; polycrystalline silicon; optical, chemical, and biological sensors; thin film shape memory alloys; materials characterization; and alternative materials and applications.

  20. Evaluation of performance of portable respiratory monitoring system based on micro-electro-mechanical-system for respiratory gated radiotherapy

    NASA Astrophysics Data System (ADS)

    Moon, Sun Young; Sung, Jiwon; Yoon, Myonggeun; Chung, Mijoo; Chung, Weon Kuu; Kim, Dong Wook

    2015-08-01

    In respiratory-gated radiotherapy of patients with lung or liver cancer, the patient's respiratory pattern and repeatability are important factors affecting therapy accuracy; it has been reported that these factors can be controlled if patients undergo respiration training. As such, this study evaluates the feasibility of micro-electro-mechanical-system (MEMS) in radiotherapy by investigating the effect of radiation on a miniature portable respiratory monitoring system based on the MEMS system, which is currently under development. Using a patient respiration simulation phantom, the time-acceleration graph measured by a normal sensor according to the phantom's respiratory movement before irradiation and the change in this graph with accumulated dose were compared using the baseline slope and the change in amplitude and period of the sine wave. The results showed that with a 400Gy accumulated dose in the sensor, a baseline shift occurred and both the amplitude and period changed. As a result, if the MEMS is applied in respiratory-gated radiotherapy, the sensor should be replaced after use with roughly 6-10 patients so as to ensure continued therapy accuracy, based on the characteristics of the sensor itself. In the future, a more diverse range of sensors should be similarly evaluated.

  1. Utilizing micro-electro-mechanical systems (MEMS) micro-shutter designs for adaptive coded aperture imaging (ACAI) technologies

    NASA Astrophysics Data System (ADS)

    Ledet, Mary M.; Starman, LaVern A.; Coutu, Ronald A., Jr.; Rogers, Stanley

    2009-08-01

    Coded aperture imaging (CAI) has been used in both the astronomical and medical communities for years due to its ability to image light at short wavelengths and thus replacing conventional lenses. Where CAI is limited, adaptive coded aperture imaging (ACAI) can recover what is lost. The use of photonic micro-electro-mechanical-systems (MEMS) for creating adaptive coded apertures has been gaining momentum since 2007. Successful implementation of micro-shutter technologies would potentially enable the use of adaptive coded aperture imaging and non-imaging systems in current and future military surveillance and intelligence programs. In this effort, a prototype of MEMS microshutters has been designed and fabricated onto a 3 mm x 3 mm square of silicon substrate using the PolyMUMPSTM process. This prototype is a line-drivable array using thin flaps of polysilicon to cover and uncover an 8 x 8 array of 20 μm apertures. A characterization of the micro-shutters to include mechanical, electrical and optical properties is provided. This prototype, its actuation scheme, and other designs for individual microshutters have been modeled and studied for feasibility purposes. In addition, microshutters fabricated from an Al-Au alloy on a quartz wafer were optically tested and characterized with a 632 nm HeNe laser.

  2. Development of High Precision Metal Micro-Electro-Mechanical-Systems Column for Portable Surface Acoustic Wave Gas Chromatograph

    NASA Astrophysics Data System (ADS)

    Iwaya, Takamitsu; Akao, Shingo; Sakamoto, Toshihiro; Tsuji, Toshihiro; Nakaso, Noritaka; Yamanaka, Kazushi

    2012-07-01

    In the field of environmental measurement and security, a portable gas chromatograph (GC) is required for the on-site analysis of multiple hazardous gases. Although the gas separation column has been downsized using micro-electro-mechanical-systems (MEMS) technology, an MEMS column made of silicon and glass still does not have sufficient robustness and a sufficiently low fabrication cost for a portable GC. In this study, we fabricated a robust and inexpensive high-precision metal MEMS column by combining diffusion-bonded etched stainless-steel plates with alignment evaluation using acoustic microscopy. The separation performance was evaluated using a desktop GC with a flame ionization detector and we achieved the high separation performance comparable to the best silicon MEMS column fabricated using a dynamic coating method. As an application, we fabricated a palm-size surface acoustic wave (SAW) GC combining this column with a ball SAW sensor and succeeded in separating and detecting a mixture of volatile organic compounds.

  3. In situ characterization of vertically oriented carbon nanofibers for three-dimensional nano-electro-mechanical device applications.

    PubMed

    Kaul, Anupama B; Megerian, Krikor G; Jennings, Andrew T; Greer, Julia R

    2010-08-01

    We have performed mechanical and electrical characterization of individual as-grown, vertically oriented carbon nanofibers (CNFs) using in situ techniques, where such high-aspect-ratio, nanoscale structures are of interest for three-dimensional (3D) electronics, in particular 3D nano-electro-mechanical-systems (NEMS). Nanoindentation and uniaxial compression tests conducted in an in situ nanomechanical instrument, SEMentor, suggest that the CNFs undergo severe bending prior to fracture, which always occurs close to the bottom rather than at the substrate-tube interface, suggesting that the CNFs are well adhered to the substrate. This is also consistent with bending tests on individual tubes which indicated that bending angles as large as approximately 70 degrees could be accommodated elastically. In situ electrical transport measurements revealed that the CNFs grown on refractory metallic nitride buffer layers were conducting via the sidewalls, whereas those synthesized directly on Si were electrically unsuitable for low-voltage dc NEMS applications. Electrostatic actuation was also demonstrated with a nanoprobe in close proximity to a single CNF and suggests that such structures are attractive for nonvolatile memory applications. Since the magnitude of the actuation voltage is intimately dictated by the physical characteristics of the CNFs, such as diameter and length, we also addressed the ability to tune these parameters, to some extent, by adjusting the plasma-enhanced chemical vapor deposition growth parameters with this bottom-up synthesis approach. PMID:20622301

  4. In-Plane Resonant Nano-Electro-Mechanical Sensors: A Comprehensive Study on Design, Fabrication and Characterization Challenges

    PubMed Central

    Hassani, Faezeh Arab; Tsuchiya, Yoshishige; Mizuta, Hiroshi

    2013-01-01

    The newly proposed in-plane resonant nano-electro-mechanical (IP R-NEM) sensor, that includes a doubly clamped suspended beam and two side electrodes, achieved a mass sensitivity of less than zepto g/Hz based on analytical and numerical analyses. The high frequency characterization and numerical/analytical studies of the fabricated sensor show that the high vacuum measurement environment will ease the resonance detection using the capacitance detection technique if only the thermoelsatic damping plays a dominant role for the total quality factor of the sensor. The usage of the intrinsic junction-less field-effect-transistor (JL FET) for the resonance detection of the sensor provides a more practical detection method for this sensor. As the second proposed sensor, the introduction of the monolithically integrated in-plane MOSFET with the suspended beam provides another solution for the ease of resonance frequency detection with similar operation to the junction-less transistor in the IP R-NEM sensor. The challenging fabrication technology for the in-plane resonant suspended gate field-effect-transistor (IP RSG-FET) sensor results in some post processing and simulation steps to fully explore and improve the direct current (DC) characteristics of the sensor for the consequent high frequency measurement. The results of modeling and characterization in this research provide a realistic guideline for these potential ultra-sensitive NEM sensors. PMID:23881137

  5. Wear of the Charité® lumbar intervertebral disc replacement investigated using an electro-mechanical spine simulator

    PubMed Central

    Moghadas, Parshia; Shepherd, Duncan ET; Hukins, David WL

    2015-01-01

    The Charité® lumbar intervertebral disc replacement was subjected to wear testing in an electro-mechanical spine simulator. Sinusoidally varying compression (0.6–2 kN, frequency 2 Hz), rotation (±2°, frequency 1 Hz), flexion–extension (6° to −3°, frequency 1 Hz) and lateral bending (±2°, frequency 1 Hz) were applied out of phase to specimens immersed in diluted calf serum at 37 °C. The mass of the ultra-high-molecular weight polyethylene component of the device was measured at intervals of 0.5, 1, 2, 3, 4 and 5 million cycles; its volume was also measured by micro-computed tomography. Total mass and volume losses were 60.3 ± 4.6 mg (mean ± standard deviation) and 64.6 ± 6.0 mm3. Corresponding wear rates were 12.0 ± 1.4 mg per million cycles and 12.8 ± 1.2 mm3 per million cycles; the rate of loss of volume corresponds to a mass loss of 11.9 ± 1.1 mg per million cycles, that is, the two sets of measurements of wear agree closely. Wear rates also agree closely with measurements made in another laboratory using the same protocol but using a conventional mechanical spine simulator. PMID:25834002

  6. An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

    PubMed

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-01-01

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation. PMID:25985165

  7. An Adaptive Compensation Algorithm for Temperature Drift of Micro-Electro-Mechanical Systems Gyroscopes Using a Strong Tracking Kalman Filter

    PubMed Central

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-01-01

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to −2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation. PMID:25985165

  8. Damage Detection Based on Power Dissipation Measured with PZT Sensors through the Combination of Electro-Mechanical Impedances and Guided Waves

    PubMed Central

    Sevillano, Enrique; Sun, Rui; Perera, Ricardo

    2016-01-01

    The use of piezoelectric ceramic transducers (such as Lead-Zirconate-Titanate—PZT) has become more and more widespread for Structural Health Monitoring (SHM) applications. Among all the techniques that are based on this smart sensing solution, guided waves and electro-mechanical impedance techniques have found wider acceptance, and so more studies and experimental works can be found containing these applications. However, even though these two techniques can be considered as complementary to each other, little work can be found focused on the combination of them in order to define a new and integrated damage detection procedure. In this work, this combination of techniques has been studied by proposing a new integrated damage indicator based on Electro-Mechanical Power Dissipation (EMPD). The applicability of this proposed technique has been tested through different experimental tests, with both lab-scale and real-scale structures. PMID:27164104

  9. Damage Detection Based on Power Dissipation Measured with PZT Sensors through the Combination of Electro-Mechanical Impedances and Guided Waves.

    PubMed

    Sevillano, Enrique; Sun, Rui; Perera, Ricardo

    2016-01-01

    The use of piezoelectric ceramic transducers (such as Lead-Zirconate-Titanate-PZT) has become more and more widespread for Structural Health Monitoring (SHM) applications. Among all the techniques that are based on this smart sensing solution, guided waves and electro-mechanical impedance techniques have found wider acceptance, and so more studies and experimental works can be found containing these applications. However, even though these two techniques can be considered as complementary to each other, little work can be found focused on the combination of them in order to define a new and integrated damage detection procedure. In this work, this combination of techniques has been studied by proposing a new integrated damage indicator based on Electro-Mechanical Power Dissipation (EMPD). The applicability of this proposed technique has been tested through different experimental tests, with both lab-scale and real-scale structures. PMID:27164104

  10. High temperature measurement set-up for the electro-mechanical characterization of robust thin film systems

    NASA Astrophysics Data System (ADS)

    Fricke, S.; Friedberger, A.; Seidel, H.; Schmid, U.

    2014-01-01

    Due to economic and environmental requirements there is a strong need both to increase the efficiency and to monitor the actual status of gas turbines, rocket engines and deep drilling systems. For these applications, micromachined pressure sensors based on a robust substrate material (e.g. sapphire) as well as strain gauges made of platinum for long-term stable operation are regarded as most promising to withstand harsh environments such as high temperature levels, aggressive media and/or high pressure loads. For pre-evaluation purposes, a novel, custom-built measurement set-up is presented allowing the determination of electro-mechanical thin film properties up to 850 °C. Key components of the measurement set-up are the one-sided clamped beam made of Al2O3 ceramics which is deflected by a quartz rod and a high precision encoder-controlled dc motor to drive the quartz rod. The specific arrangement of the infrared halogen heaters in combination with the gold coated quartz half shells ensures a high degree of temperature homogeneity along the beam axis. When exposed to tensile as well as compressive load conditions, the corresponding gauge factor values of 1 µm thick platinum thin films show a good comparison at room temperature and in the temperature range from 600 up to 850 °C where the effects originating from grain boundaries or from the film surfaces are negligible. Between 150 and 600 °C, however, a strong deviation in the gauge factor determination depending on the mechanical load condition is observed, which is attributed to the gliding of adjacent grains.

  11. Electro-mechanical characterization of MgB2 wires for the Superconducting Link Project at CERN

    NASA Astrophysics Data System (ADS)

    Konstantopoulou, K.; Ballarino, A.; Gharib, A.; Stimac, A.; Garcia Gonzalez, M.; Perez Fontenla, A. T.; Sugano, M.

    2016-08-01

    In previous years, the R & D program between CERN and Columbus Superconductors SpA led to the development of several configurations of MgB2 wires. The aim was to achieve excellent superconducting properties in high-current MgB2 cables for the HL-LHC upgrade. In addition to good electrical performance, the superconductor shall have good mechanical strength in view of the stresses during operation (Lorenz forces and thermal contraction) and handling (tension and bending) during cabling and installation at room temperature. Thus, the study of the mechanical properties of MgB2 wires is crucial for the cable design and its functional use. In the present work we report on the electro-mechanical characterization of ex situ processed composite MgB2 wires. Tensile tests (critical current versus strain) were carried out at 4.2 K and in a 3 T external field by means of a purpose-built bespoke device to determine the irreversible strain limit of the wire. The minimum bending radius of the wire was calculated taking into account the dependence of the critical current with the strain and it was then used to obtain the minimum twist pitch of MgB2 wires in the cable. Strands extracted from cables having different configurations were tested to quantify the critical current degradation. The Young’s modulus of the composite wire was measured at room temperature. Finally, all measured mechanical parameters will be used to optimize an 18-strand MgB2 cable configuration.

  12. On-Chip Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing.

    PubMed

    Erfan, Mazen; Sabry, Yasser M; Sakr, Mohammad; Mortada, Bassem; Medhat, Mostafa; Khalil, Diaa

    2016-05-01

    In this work, we study the detection of acetylene (C2H2), carbon dioxide (CO2) and water vapor (H2O) gases in the near-infrared (NIR) range using an on-chip silicon micro-electro-mechanical system (MEMS) Fourier transform infrared (FT-IR) spectrometer in the wavelength range 1300-2500 nm (4000-7692 cm(-1)). The spectrometer core engine is a scanning Michelson interferometer micro-fabricated using a deep-etching technology producing self-aligned components. The light is free-space propagating in-plane with respect to the silicon chip substrate. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator corresponding to about 30 cm(-1) resolution. Multi-mode optical fibers are used to connect light between the wideband light source, the interferometer, the 10 cm gas cell, and the optical detector. A wide dynamic range of gas concentration down to 2000 parts per million (ppm) in only 10 cm length gas cell is demonstrated. Extending the wavelength range to the mid-infrared (MIR) range up to 4200 nm (2380 cm(-1)) is also experimentally demonstrated, for the first time, using a bulk micro-machined on-chip MEMS FT-IR spectrometer. The obtained results open the door for an on-chip optical gas sensor for many applications including environmental sensing and industrial process control in the NIR/MIR spectral ranges. PMID:27044847

  13. Sensing of damage and substrate stress in concrete using electro-mechanical impedance measurements of bonded PZT patches

    NASA Astrophysics Data System (ADS)

    Narayanan, Arun; Subramaniam, Kolluru V. L.

    2016-09-01

    The influence of stress and induced damage in concrete on the electro-mechanical (EM) impedance response of bonded PZT patches is evaluated for applied compressive loading. Full field displacements obtained from digital image correlation are used to evaluate the level of stress-induced damage in concrete. Stress in the substrate produces an imposed strain on the PZT. A change in the imposed strain produces a rightward frequency shift and an increase in the amplitude of the resonant peak in the EM conductance spectrum of the PZT. An increase in the substrate compliance produces a decrease in the resonant frequency and an increase in the amplitude of the resonant peak. Changes in the resonant peak in the conductance spectrum induced by increasing substrate stress are of a significant magnitude when compared with the changes induced by damage. In the early stages of damage associated with distributed microcracking, the counteracting influences of increasing level of damage and increasing stress on the resonant peak result in no shift in frequency for measurements under applied load. There is however an increase in the amplitude of the resonance peak. When the applied stress is removed, there is a net decrease in frequency resulting from damage in the form of distributed microcracks. Measures of changes in the resonant peak based on root mean square deviation (RMSD), do not show any observable change when measurements are performed under applied loading. There is a consistent increase in RMSD values and frequency shift with increasing damage when the applied stress is removed. The centroidal measure of the normalized frequency spectrum reflects changes in substrate stress. At higher applied stress levels, there is a nonlinear increase in damage, leading to localization and cracking. The influence of damage is dominant in this region and significant changes are obtained in the RMSD values in both loaded and unloaded conditions.

  14. Electro-Mechanical Curriculum.

    ERIC Educational Resources Information Center

    EASTCONN Regional Educational Services Center, North Windham, CT.

    This electromechanical technician curriculum covers the following general areas: (1) basic soldering; (2) reading diagrams and following schematics; and (3) repairing circuitry and mechanics common to major appliances, vending machines, amusement equipment, and small office machines. The manual includes the following sections: (1) course…

  15. Mobile Seamless Technology Enhanced CSL Oral Communication

    ERIC Educational Resources Information Center

    Lan, Yu-Ju; Lin, Yen-Ting

    2016-01-01

    The current study aimed at investigating how mobile seamless technology can be used to enhance the pragmatic competence of learners of Chinese as a second language (CSL). 34 overseas CSL learners participated in this study. They were randomly assigned into two groups: the classroom group, executing language tasks in fake contexts in a traditional…

  16. Seamless Navigation Using Various Sensors: AN Overview of the Seamless Navigation Campaign

    NASA Astrophysics Data System (ADS)

    Nakagawa, M.; Yamada, Y.; Namie, H.; Ebinuma, T.; Kubo, N.; Kawaguchi, T.; Yoshida, M.; Yasuda, A.

    2012-07-01

    Seamless positioning techniques in indoor and outdoor environments are necessary for obtaining sensor locations. However, no definitive indoor-outdoor navigation system simultaneously provides high accuracy, high availability and low installation cost. Furthermore, crowded indoor-outdoor navigation systems consisting of multiple techniques will destructively interfere with each other, but an exclusive navigation environment will have difficulty providing stable location services for users. This anticipated issue needs to be investigated with experimental data and simulation results. However, experiments that are deliberately overcrowded with disparate location systems are rare. Therefore, the initial focus in our research was the construction of a test environment for indoor-outdoor seamless navigation experiments. Based on "Standards and Recommended Practices" (SARPs), we focused on accuracy, availability, continuity and integrity to verify the effects of seamless navigation under a combination of as many disparate systems and sensors as possible. We then conducted data acquisition and data analysis in seamless navigation through four integrated experiments. Based on the results of our experiments, we summarize some observations about seamless navigation using multiple navigation systems, and offer examples of the representative issues in our research. We also suggest some directions in indoor-outdoor navigation environment construction for seamless positioning using disparate systems and sensors.

  17. Crack growth phenomena in micro-machined single crystal silicon and design implications for micro electro mechanical systems (MEMS)

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Alissa Mirella

    The creation of micron-sized mechanisms using semiconductor processing technology is known collectively as MEMS, or Micro Electro Mechanical Systems. Many MEMS devices, such as accelerometers and switches, have mechanical structures fabricated from single crystal silicon, a brittle material. The reliability and longevity of these devices depends on minimizing the probability of fracture, and therefore requires a thorough understanding of crack growth phenomena in silicon. In this study, a special micro-machined fracture specimen, the compression-loaded double cantilever beam, was developed to study fracture phenomena in single crystal silicon on a size scale relevant to MEMS. The decreasing stress intensity geometry of this sample provided stable, controllable crack propagation in test sections as thin as 100 mum. Several common MEMS fabrication methods (plasma and chemical etch) were used to achieve a range of surface finishes. A 650 A thick titanium crack gage was used to directly measure crack extension as a function of time using the potential drop technique. High speed (100 MHz) data acquisition techniques were employed to capture fracture events on the sub-microsecond time scale. The stability of the sample design and the micron-scale resolution of the crack gage facilitated investigation into the existence of a stress corrosion effect in silicon. No evidence of sub-critical crack growth due to exposure to humid air was found in carefully controlled tests lasting up to 24 hours. Rapid crack propagation velocities (>1 km/s) during quasi-static loading were recorded using high speed data acquisition techniques. Unique evidence was found of reflected stress waves causing multiple, momentary arrests during rapid fracture events. These measurements, along with atomic force microscope scans of the fracture surfaces, offer new insight into the kinetics of the fracture process in silicon. Over 100 micro-machined samples were fractured in this research. Weibull

  18. High resolution lithography-compatible micro-electro-discharge machining of bulk metal foils for micro-electro-mechanical systems

    NASA Astrophysics Data System (ADS)

    Richardson, Mark Thomas

    The application of batch mode micro-electro-discharge machining (microEDM) to the fabrication of micro-electro-mechanical systems has opened the door to lithographically compatible precision machining of all bulk metals. High volume applications in biomedical, communications, and consumer electronics devices are enabled by this technology. This dissertation explores the capabilities, limitations, and further improvement of high density batch mode microEDM. There are four parts to this effort described below. A machining resolution study of high density features in stainless steel identifies the design space. Lithographically fabricated copper tools with single cross, parallel line, and circle/square array features of 5--100microm width and 5--75microm spacing were used. The observed discharge gap varies with shape, spacing, and feature location from 3.8--8microm. As tool feature density is increased, debris accumulation effects begin to dominate, eventually degrading both tool and workpiece. Two new techniques for mitigating this debris build-up are separately investigated. The first is a silicon passivation coating which suppresses spurious discharges triggered from the sidewalls of the machining tool. By this method, for high density batch machining, mean tool wear rate decreases from a typical rate of about 34% to 1.7% and machining non-uniformity reduces from 4.9microm to 1.1microm across the workpiece. The second involves a two-step machining process that enhances the hydraulic removal of machining debris and therefore throughput. Wireless RF signals are inherently emitted by the micro-discharge process. This thesis describes the first reported wireless detection of debris accumulation during microEDM, enabling direct monitoring of machining quality in real time with 5dBm signal drop. The first wireless detection of the interface between two stacked metals during microEDM is also reported giving a 10dBm signal change. The technique enables direct monitoring of

  19. 49 CFR 180.212 - Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cylinders and seamless UN pressure receptacles. 180.212 Section 180.212 Transportation Other Regulations... seamless UN pressure receptacles. (a) General requirements for repair of DOT 3-series cylinders and UN pressure receptacles. (1) No person may repair a DOT 3-series cylinder or a seamless UN pressure...

  20. 49 CFR 180.212 - Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... cylinders and seamless UN pressure receptacles. 180.212 Section 180.212 Transportation Other Regulations... cylinders and seamless UN pressure receptacles. (a) General requirements for repair of DOT 3-series cylinders and UN pressure receptacles. (1) No person may repair a DOT 3-series cylinder or a seamless...

  1. QUENCH STUDIES AND PREHEATING ANALYSIS OF SEAMLESS

    SciTech Connect

    Palczewski, Ari; Geng, Rongli; Eremeev, Grigory

    2013-09-01

    One of the alternative manufacturing technologies for SRF cavities is hydroforming from seamless tubes. Although this technology has produced cavities with gradient and Q-values comparable to standard EBW/EP cavities, a few questions remain. One of these questions is whether the quench mechanism in hydroformed cavities is the same as in standard electron beam welded cavities. Towards this effort Jefferson Lab performed quench studies on 2 9 cell seamless hydroformed cavities. These cavities include DESY's - Z163 and Z164 nine-cell cavities hydroformed at DESY. Initial Rf test results Z163 were published in SRF2011. In this report we will present post JLAB surface re-treatment quench studies for each cavity. The data will include OST and T-mapping quench localization as well as quench location preheating analysis comparing them to the observations in standard electron beam welded cavities.

  2. Effects of Persistent Atrial Fibrillation-Induced Electrical Remodeling on Atrial Electro-Mechanics – Insights from a 3D Model of the Human Atria

    PubMed Central

    Adeniran, Ismail; MacIver, David H.; Garratt, Clifford J.; Ye, Jianqiao; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Aims Atrial stunning, a loss of atrial mechanical contraction, can occur following a successful cardioversion. It is hypothesized that persistent atrial fibrillation-induced electrical remodeling (AFER) on atrial electrophysiology may be responsible for such impaired atrial mechanics. This simulation study aimed to investigate the effects of AFER on atrial electro-mechanics. Methods and Results A 3D electromechanical model of the human atria was developed to investigate the effects of AFER on atrial electro-mechanics. Simulations were carried out in 3 conditions for 4 states: (i) the control condition, representing the normal tissue (state 1) and the tissue 2–3 months after cardioversion (state 2) when the atrial tissue recovers its electrophysiological properties after completion of reverse electrophysiological remodelling; (ii) AFER-SR condition for AF-remodeled tissue with normal sinus rhythm (SR) (state 3); and (iii) AFER-AF condition for AF-remodeled tissue with re-entrant excitation waves (state 4). Our results indicate that at the cellular level, AFER (states 3 & 4) abbreviated action potentials and reduced the Ca2+ content in the sarcoplasmic reticulum, resulting in a reduced amplitude of the intracellular Ca2+ transient leading to decreased cell active force and cell shortening as compared to the control condition (states 1 & 2). Consequently at the whole organ level, atrial contraction in AFER-SR condition (state 3) was dramatically reduced. In the AFER-AF condition (state 4) atrial contraction was almost abolished. Conclusions This study provides novel insights into understanding atrial electro-mechanics illustrating that AFER impairs atrial contraction due to reduced intracellular Ca2+ transients. PMID:26606047

  3. Torsional Stability of Aluminum Alloy Seamless Tubing

    NASA Technical Reports Server (NTRS)

    Moore, R L; Paul, D A

    1939-01-01

    Torsion tests were made on 51ST aluminum-alloy seamless tubes having diameter-to-thickness ratios of from 77 to 139 and length-to-diameter ratios of from 1 to 60. The torsional strengths developed in the tubes which failed elastically (all tubes having lengths greater than 2 to 6 times the diameter) were in most cases within 10 percent of the value indicated by the theories of Donnel, Timoshenko, and Sturm, assuming a condition of simply supported ends.

  4. Impact Damage Detection in Composite Plates using a Self-diagnostic Electro-Mechanical Impedance-based Structural Health Monitoring System

    NASA Astrophysics Data System (ADS)

    Sharif-Khodaei, Z.; Ghajari, M.; Aliabadi, M. H.

    2015-03-01

    In this work, application of the electro-mechanical impedance (EMI) method in structural health monitoring as a damage detection technique has been investigated. A damage metric based on the real and imaginary parts of the impedance measures is introduced. Numerical and experimental tests are carried out to investigate the applicability of the method for various types of damage, such as debonding between the transducers and the plate, faulty sensors and impact damage in composite plates. The effect of several parameters, such as environmental effects, frequency sweep, severity of damage, location of damage, etc., on the damage metric has been reported.

  5. The magnetic properties of seamless steel pipe

    NASA Astrophysics Data System (ADS)

    Willcock, S. N. M.; Tanner, B. K.; Mundell, P. A.

    1987-03-01

    The magnetic and metallurgical properties of seamless pipe steel have been investigated as a function of position around the pipe circumference. No changes in magnetic properties were found to be associated with the four cycle spiral variations in pipe wall thickness introduced during forging. A weaker single cycle thickness variation was accompanied by a change both in magnetic properties and pearlite fraction. The coercive field predicted from an empirical relationship between grain size and ferrite and pearlite fractions was found to be in excellent agreement with that measured experimentally.

  6. Electro-mechanical properties of REBCO coated conductors from various industrial manufacturers at 77 K, self-field and 4.2 K, 19 T

    NASA Astrophysics Data System (ADS)

    Barth, C.; Mondonico, G.; Senatore, C.

    2015-04-01

    Rare-Earth-barium-copper-oxide tapes are now available from several industrial manufacturers and are very promising conductors in high field applications. Due to diverging materials and deposition processes, these manufacturers’ tapes can be expected to differ in their electro-mechanical and mechanical properties. For magnets designers, these are together with the conductors’ in-field critical current performance of the highest importance in choosing a suitable conductor. In this work, the strain and stress dependence of the current carrying capabilities as well as the stress and strain correlation are investigated for commercial coated conductors from Bruker HTS, Fujikura, SuNAM, SuperOx and SuperPower at 77 K, self-field and 4.2 K, 19 T.

  7. Multi-physics simulation and fabrication of a compact 128 × 128 micro-electro-mechanical system Fabry-Perot cavity tunable filter array for infrared hyperspectral imager.

    PubMed

    Meng, Qinghua; Chen, Sihai; Lai, Jianjun; Huang, Ying; Sun, Zhenjun

    2015-08-01

    This paper demonstrates the design and fabrication of a 128×128 micro-electro-mechanical systems Fabry-Perot (F-P) cavity filter array, which can be applied for the hyperspectral imager. To obtain better mechanical performance of the filters, F-P cavity supporting structures are analyzed by multi-physics finite element modeling. The simulation results indicate that Z-arm is the key component of the structure. The F-P cavity array with Z-arm structures was also fabricated. The experimental results show excellent parallelism of the bridge deck, which agree with the simulation results. A conclusion is drawn that Z-arm supporting structures are important to hyperspectral imaging system, which can achieve a large tuning range and high fill factor compared to straight arm structures. The filter arrays have the potential to replace the traditional dispersive element. PMID:26368101

  8. Electro-Mechanical Manipulator for Use in the Remote Equipment Decontamination Cell at the Defense Waste Processing Facility, Savannah River Site - 12454

    SciTech Connect

    Lambrecht, Bill; Dixon, Joe; Neuville, John R.

    2012-07-01

    One of the legacies of the cold war is millions of liters of radioactive waste. One of the locations where this waste is stored is at the Savannah River Site (SRS) in South Carolina. A major effort to clean up this waste is on-going at the defense waste processing facility (DWPF) at SRS. A piece of this effort is decontamination of the equipment used in the DWPF to process the waste. The remote equipment decontamination cell (REDC) in the DWPF uses electro-mechanical manipulators (EMM) arms manufactured and supplied by PaR Systems to decontaminate DWPF process equipment. The decontamination fluid creates a highly corrosive environment. After 25 years of operational use the original EMM arms are aging and need replacement. To support continued operation of the DWPF, two direct replacement EMM arms were delivered to the REDC in the summer of 2011. (authors)

  9. In situ electro-mechanical experiments and mechanics modeling of tensile cracking in indium tin oxide thin films on polyimide substrates

    NASA Astrophysics Data System (ADS)

    Peng, Cheng; Jia, Zheng; Bianculli, Dan; Li, Teng; Lou, Jun

    2011-05-01

    Indium tin oxide (ITO) thin films supported by polymer substrates have been widely used as transparent electrodes/interconnects in flexible electronics. Understanding the electro-mechanical behaviors of such material system is crucial for reliable operation of flexible devices under large deformation. In this paper, we performed in situ mechanical and electrical tests of ITO thin films with two different thicknesses (200 and 80 nm) deposited on polyimide substrates inside a scanning electron microscope. The crack initiation and propagation, crack density evolution and the corresponding electrical resistance variation were systematically investigated. It was found that cracks initiated at a higher tensile strain level and saturated with a higher density in thinner ITO films. Integrated with a coherently formulated mechanics model, the cohesive toughness and fracture strength of ITO thin films and the ITO/polyimide interfacial toughness were quantitatively determined. The experimentally observed thickness dependence of the saturated crack density in ITO thin films was also quantitatively verified by the model.

  10. Biological application of micro-electro mechanical systems microelectrode array sensors for direct measurement of phosphate in the enhanced biological phosphorous removal process.

    PubMed

    Lee, Woo Hyoung; Lee, Jin-Hwan; Bishop, Paul L; Papautsky, Ian

    2009-08-01

    The determination of phosphate has been of great importance in the fields of clinical, environmental, and horticultural analysis for over three decades. New cobalt-based micro-electro mechanical systems (MEMS) microelectrode array (MEA) sensors for direct measurement of phosphate in small environmental samples, such as microbial aggregates, has been introduced and applied here for in situ measurement of phosphate within activated sludge flocs in the enhanced biological phosphorus removal process. The MEMS technologies offer the advantages of accurate fabrication methods, reduced complexity of the fabrication process, mass production, low cost, and increased reliability. Well-defined phosphate profiles across the flocs were observed under anaerobic conditions, during which, phosphate was released from the flocs, using the MEMS MEA sensor. The microprofiles were compared with the microprofiles measured using conventional phosphate microelectrodes. The developed MEMS MEA sensors were useful tools for the in situ measurement of phosphate in small aggregates. PMID:19774851

  11. Performance of 3-cell Seamless Niobium cavities

    SciTech Connect

    Kneisel, Peter K.; Ciovati, Gianluigi; Jelezov, I.; Singer, W.; Singer, X.

    2009-11-01

    In the last several months we have surface treated and cryogenically tested three TESLA-type 3-cell cavities, which had been manufactured at DESY as seamless assemblies by hydroforming. The cavities were completed at JLab with beam tube/flange assemblies. All three cavities performed very well after they had been post-purified with titanium at 1250C for 3 hrs. The cavities, two of which consisted of an end cell and 2 center cells and one was a center cell assembly, achieved gradients of Eacc = 32 MV/m, 34 MV/m and 35 MV/m without quenches. The performance was limited by the appearance of the “Q-drop” in the absence of field emission. This contribution reports about the various measurements undertaken with these cavities.

  12. Seamless stitching of tile scan microscope images.

    PubMed

    Legesse, F B; Chernavskaia, O; Heuke, S; Bocklitz, T; Meyer, T; Popp, J; Heintzmann, R

    2015-06-01

    For diagnostic purposes, optical imaging techniques need to obtain high-resolution images of extended biological specimens in reasonable time. The field of view of an objective lens, however, is often smaller than the sample size. To image the whole sample, laser scanning microscopes acquire tile scans that are stitched into larger mosaics. The appearance of such image mosaics is affected by visible edge artefacts that arise from various optical aberrations which manifest in grey level jumps across tile boundaries. In this contribution, a technique for stitching tiles into a seamless mosaic is presented. The stitching algorithm operates by equilibrating neighbouring edges and forcing the brightness at corners to a common value. The corrected image mosaics appear to be free from stitching artefacts and are, therefore, suited for further image analysis procedures. The contribution presents a novel method to seamlessly stitch tiles captured by a laser scanning microscope into a large mosaic. The motivation for the work is the failure of currently existing methods for stitching nonlinear, multimodal images captured by our microscopic setups. Our method eliminates the visible edge artefacts that appear between neighbouring tiles by taking into account the overall illumination differences among tiles in such mosaics. The algorithm first corrects the nonuniform brightness that exists within each of the tiles. It then compensates for grey level differences across tile boundaries by equilibrating neighbouring edges and forcing the brightness at the corners to a common value. After these artefacts have been removed further image analysis procedures can be applied on the microscopic images. Even though the solution presented here is tailored for the aforementioned specific case, it could be easily adapted to other contexts where image tiles are assembled into mosaics such as in astronomical or satellite photos. PMID:25787148

  13. 49 CFR 180.212 - Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles. 180.212 Section 180.212 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED)...

  14. 49 CFR 180.212 - Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... cylinders and seamless UN pressure receptacles. 180.212 Section 180.212 Transportation Other Regulations..., Maintenance and Use of Cylinders § 180.212 Repair of seamless DOT 3-series specification cylinders and... prescribed in § 180.215. (b) Repairs not requiring prior approval. Approval is not required for the...

  15. 49 CFR 180.212 - Repair of seamless DOT 3-series specification cylinders and seamless UN pressure receptacles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cylinders and seamless UN pressure receptacles. 180.212 Section 180.212 Transportation Other Regulations..., Maintenance and Use of Cylinders § 180.212 Repair of seamless DOT 3-series specification cylinders and... prescribed in § 180.215. (b) Repairs not requiring prior approval. Approval is not required for the...

  16. THE PREPARATION OF CURRICULUM MATERIALS AND THE DEVELOPMENT OF TEACHERS FOR AN EXPERIMENTAL APPLICATION OF THE CLUSTER CONCEPT OF VOCATIONAL EDUCATION AT THE SECONDARY SCHOOL LEVEL. VOLUME IV, INSTRUCTIONAL PLANS FOR THE ELECTRO-MECHANICAL CLUSTER.

    ERIC Educational Resources Information Center

    MALEY, DONALD

    DESIGNED FOR USE WITH 11TH AND 12TH GRADE STUDENTS, THIS CURRICULUM GUIDE FOR THE OCCUPATIONAL CLUSTER IN ELECTRO-MECHANICAL INSTALLATION AND REPAIR WAS DEVELOPED BY PARTICIPATING TEACHERS FROM RESULTS OF THE RESEARCH PROCEDURES DESCRIBED IN VOLUME I (VT 004 162). THE COURSE DESCRIPTIONS, NEED FOR THE COURSE, COURSE OBJECTIVES, PROCEDURES, AND…

  17. Seamless cross-scale modeling with SCHISM

    NASA Astrophysics Data System (ADS)

    Zhang, Yinglong J.; Ye, Fei; Stanev, Emil V.; Grashorn, Sebastian

    2016-06-01

    We present a new 3D unstructured-grid model (SCHISM) which is an upgrade from an existing model (SELFE). The new advection scheme for the momentum equation includes an iterative smoother to reduce excess mass produced by higher-order kriging method, and a new viscosity formulation is shown to work robustly for generic unstructured grids and effectively filter out spurious modes without introducing excessive dissipation. A new higher-order implicit advection scheme for transport (TVD2) is proposed to effectively handle a wide range of Courant numbers as commonly found in typical cross-scale applications. The addition of quadrangular elements into the model, together with a recently proposed, highly flexible vertical grid system (Zhang et al., A new vertical coordinate system for a 3D unstructured-grid model. Ocean Model. 85, 2015), leads to model polymorphism that unifies 1D/2DH/2DV/3D cells in a single model grid. Results from several test cases demonstrate the model's good performance in the eddying regime, which presents greater challenges for unstructured-grid models and represents the last missing link for our cross-scale model. The model can thus be used to simulate cross-scale processes in a seamless fashion (i.e. from deep ocean into shallow depths).

  18. Nearly Seamless Vacuum-Insulated Boxes

    NASA Technical Reports Server (NTRS)

    Stepanian, Christopher J.; Ou, Danny; Hu, Xiangjun

    2010-01-01

    A design concept, and a fabrication process that would implement the design concept, have been proposed for nearly seamless vacuum-insulated boxes that could be the main structural components of a variety of controlled-temperature containers, including common household refrigerators and insulating containers for shipping foods. In a typical case, a vacuum-insulated box would be shaped like a rectangular parallelepiped conventional refrigerator box having five fully closed sides and a hinged door on the sixth side. Although it is possible to construct the five-closed-side portion of the box as an assembly of five unitary vacuum-insulated panels, it is not desirable to do so because the relatively high thermal conductances of the seams between the panels would contribute significant amounts of heat leakage, relative to the leakage through the panels themselves. In contrast, the proposal would make it possible to reduce heat leakage by constructing the five-closed-side portion of the box plus the stationary portion (if any) of the sixth side as a single, seamless unit; the only remaining seam would be the edge seal around the door. The basic cross-sectional configuration of each side of a vacuum-insulated box according to the proposal would be that of a conventional vacuum-insulated panel: a low-density, porous core material filling a partially evacuated space between face sheets. However, neither the face sheets nor the core would be conventional. The face sheets would be opposite sides of a vacuum bag. The core material would be a flexible polymer-modified silica aerogel of the type described in Silica/Polymer and Silica/Polymer/Fiber Composite Aero - gels (MSC-23736) in this issue of NASA Tech Briefs. As noted in that article, the stiffness of this core material against compression is greater than that of prior aerogels. This is an important advantage because it translates to greater retention of thickness and, hence, of insulation performance when pressure is

  19. Functional Micro-Dispensers based on Micro-Electro-Mechanical-Systems (MEMS) integrated with fabrics as functional materials to protect humans from mosquito feeding.

    PubMed

    Bernier, Ulrich R; Gurman, Pablo; Clark, Gary G; Elman, Noel

    2015-12-28

    Functional Micro-Dispensers (FMDs) based on Micro-Electro-Mechanical-Systems (MEMS) were designed to deliver spatial repellents that reduce the ability of mosquitoes to feed on humans. FMDs were integrated with fabrics as functional materials for protection against mosquito bites. The use of MEMS devices provides an unprecedented control over the release kinetics by means of integration with electronics for selective and timely activation of each device to perform controlled release of pesticides in air. In addition, because MEMS manufacturing techniques evolved from the microelectronic industry, FMDs can be mass produced at very low cost. Trials using FMDs that contained transfluthrin improved protection against mosquito feeding in human subjects above that of permethrin-treated uniform fabric worn on the arm of the volunteer. The overall reduction in feeding was approximately 90% compared to the untreated fabric control, and about 50% reduction compared to the permethrin-treated fabric control. The devices were efficacious over course of 32 days. FMDs have the potential for a simple and cost-effective implementation for mass adoption as wearable devices integrated in fabrics as active functional materials. PMID:26415856

  20. Inverted electro-mechanical behaviour induced by the irreversible domain configuration transformation in (K,Na)NbO3-based ceramics

    PubMed Central

    Huan, Yu; Wang, Xiaohui; Koruza, Jurij; Wang, Ke; Webber, Kyle G.; Hao, Yanan; Li, Longtu

    2016-01-01

    Miniaturization of domains to the nanometer scale has been previously reported in many piezoelectrics with two-phase coexistence. Despite the observation of nanoscale domain configuration near the polymorphic phase transition (PPT) regionin virgin (K0.5Na0.5)NbO3 (KNN) based ceramics, it remains unclear how this domain state responds to external loads and influences the macroscopic electro-mechanical properties. To this end, the electric-field-induced and stress-induced strain curves of KNN-based ceramics over a wide compositional range across PPT were characterized. It was found that the coercive field of the virgin samples was highest in PPT region, which was related to the inhibited domain wall motion due to the presence of nanodomains. However, the coercive field was found to be the lowest in the PPT region after electrical poling. This was related to the irreversible transformation of the nanodomains into micron-sized domains during the poling process. With the similar micron-sized domain configuration for all poled ceramics, the domains in the PPT region move more easily due to the additional polarization vectors. The results demonstrate that the poling process can give rise to the irreversible domain configuration transformation and then account for the inverted macroscopic piezoelectricity in the PPT region of KNN-based ceramics. PMID:26915972

  1. In-situ Iberian pig carcass classification using a micro-electro-mechanical system (MEMS)-based near infrared (NIR) spectrometer.

    PubMed

    Zamora-Rojas, E; Pérez-Marín, D; De Pedro-Sanz, E; Guerrero-Ginel, J E; Garrido-Varo, A

    2012-03-01

    Iberian pig (IP) products are gourmet foods highly appreciated at international markets, reaching high prices, because of its exquisite flavors. At present, there aren't practical and affordable analytical methods which can authenticate every single piece put on the market. This paper reports on the performance of a handheld micro-electro-mechanical system (MEMS)-based spectrometer (1600-2400nm) for authentication-classification of individual IP carcasses into different commercial categories. Performance (accuracy and instrumental design) of the instrument was compared with that of high-resolution NIRS monochromators (400-2500nm). A total of 300 carcasses of IPs raised under different feeding regimes ("Acorn", "Recebo" and "Feed") were analyzed in three modes (intact fat in the carcass, skin-free subcutaneous fat samples and melted fat samples). The best classification results for the MEMS instrument were: 93.9% "Acorn" carcasses correctly classified, 96.4% "Feed" and 60.6% "Recebo", respectively. Evaluation of model performance confirmed the suitability of the handheld device for individual, fast, non-destructive, low-cost analysis of IP carcasses on the slaughterhouse line. PMID:22075264

  2. Seamless Handovers in Cobra Teardrop Satellite Arrays

    NASA Astrophysics Data System (ADS)

    Draim, John E.; Cefola, Paul J.; Ernandes, Kenneth J.

    2007-06-01

    Satellite systems provide the most efficient and possibly the only means of achieving two-way global communications with mobile systems (ships, aircraft, and vehicular traffic). To date, such systems have used only circular orbits, either GEO or LEO. Medium altitude elliptical constellations, on the other hand, can provide an efficient and affordable alternative to these architectures. Users also benefit from their very high average and minimum elevation angles, resulting in minimum signal attenuation. Cobra Teardrop is unique in that it employs time synchronized 8-h left- and right-leaning elliptical orbits giving mid-latitude observers the illusion of viewing a single satellite continuously orbiting almost directly overhead! In reality, observers see six different satellites per day, for 4 h each (while in their active duty cycles). By design, Teardrop satellites are physically in very close proximity at the handover points. This favorable geometry can be utilized to achieve a seamless handover from one satellite to the other (not requiring any electronic buffering). Handover is accomplished at the precise instant that the total path lengths from the transmitting station through both satellites to the receiving station are exactly equal. In these improved Cobra Teardrop arrays, an order of magnitude increase in global communications capacity (equivalent GEO slots) can be realized over earlier Basic Cobra systems. For decades into the future, these new orbital systems could satisfy a widely expanding range of commercial, government, and military high data rate communication requirements. These would include, but not be limited to, satellite cellular, air traffic control, meteorological, and combat net radio systems. With these arrays, a much larger number of system operators could be supported, without mutual electronic interference, than would ever be possible with circular orbits.

  3. Development of a GPS Seamless Archive

    NASA Astrophysics Data System (ADS)

    Scharber, M.; Bock, Y.; Gilmore, B.

    2003-12-01

    The Scripps Orbit and Permanent Array Center (SOPAC) has completed development of software for UNAVCO's GPS Seamless Archive Center (GSAC). The GSAC is a collection of GPS data archives and their operating agencies that have agreed to exchange information about their individual data holdings. GSAC allows a user to locate GPS data and metadata from these different archives through a single interface; hence GSAC is an operating virtual observatory for continuous and "campaign" GPS data. Data providers collect or generate data and then supply the data to data wholesalers. Data wholesalers collect and archive data and metadata, from one or more data providers. GSAC currently has 7 U.S.-based data wholesalers (NASA's CDDIS, UC Berkeley's NCEDC, NGS, CWU's PANGA archive, SCEC, SOPAC, and UNAVCO). Together these archives hold over 2 million GPS data (RINEX) files collected for over 10,000 monuments, including a nearly complete set of data collected between 1986 and 2003 for the global network and western North America, and a significant quantity of data collected by U.S. scientists in other tectonically active regions. Data retailers collect information from the wholesalers in a well-defined manner and run a service for clients to access the information. Currently there are two GSAC retailers (SOPAC and UNAVCO). The GSAC software suite includes a Web-based interactive client (GSAC Wizard) to locate data, a command-line client to locate and download data, and a retailer service that uses a macro language to pass commands to a server using the http url. The command-line client uses the retailer service to communicate with the retailer server. SOPAC has also modified its map interface to work with GSAC so that GPS data can be located using a spatial context, and maintains a GSAC Home Page (http://gsac.ucsd.edu). In this abstract, we highlight achievements and lessons learned from our development of the current system, but focus on a possible next generation GSAC that will

  4. A chemo-electro-mechanical model for simulation of responsive deformation of glucose-sensitive hydrogels with the effect of enzyme catalysis

    NASA Astrophysics Data System (ADS)

    Li, Hua; Luo, Rongmo; Birgersson, Erik; Lam, Khin Yong

    2009-02-01

    A multi-effect-coupling glucose-stimulus (MECglu) model is developed and solved numerically for the swelling behavior of soft smart hydrogels responding to changes in the environmental glucose concentration. The model considers the effect of the glucose oxidation reaction catalyzed by enzymes including glucose oxidase and catalase. It is composed of the Nernst-Planck equation for the mobile species in the solvent, the Poisson equation for the electric potential, and a nonlinear mechanical equation for the large deformations of the hydrogel that arise due to the conversion of chemical energy to mechanical. Based on the theory of the chemo-electro-mechanical-coupled fields, the formulation of the fixed charge groups bound onto the cross-linked polymer network is associated with the change of the ambient solution pH. The MECglu model is validated by comparison between the steady-state computation and experimental equilibrium swelling curves, and good agreement is obtained. A parameter study is then conducted by steady-state simulations to ascertain the impact of various solvent parameters on the responsive swelling behavior of the hydrogel. One key parameter is the glucose concentration, which is varied within the range of practical physiological glucose concentrations from 0 to 16.5 mM (300 mg/ml) to support the design and optimization of an insulin delivery system based on a glucose-sensitive hydrogel with immobilized glucose oxidase and catalase. The influence of oxygen and glucose concentrations in the solvent is then further studied for the distributive profiles of reacting and diffusive species concentrations, the electric potential, the displacement, as well as the swelling ratio of the glucose-sensitive hydrogel.

  5. Electro-Mechanical Coaxial Valve

    NASA Technical Reports Server (NTRS)

    Patterson, Paul R (Inventor)

    2004-01-01

    Coaxial valves usually contain only one moving part. It has not been easy, then, to provide for electric motor actuation. Many actuators being proposed involve designs which lead to bulky packages. The key facing those improving coaxial valves is the provision of suitable linear actuation. The valve herein indudes a valve housing with a flow channel there-through. Arranged in the flow channel is a closing body. In alignment with the closing body is a ball screw actuator which includes a ball nut and a cylindrical screw. The ball nut sounds a threaded portion of the cylindrical screw. The cylindrical screw is provided with a passageway there-through through which fluid flows. The cylindrical screw is disposed in the flow channel to become a control tube adapted to move toward and away from the valve seat. To rotate the ball nut an actuating drive is employed driven by a stepper motor.

  6. Effects of alloying and local order in AuNi contacts for Ohmic radio frequency micro electro mechanical systems switches via multi-scale simulation

    NASA Astrophysics Data System (ADS)

    Gaddy, Benjamin E.; Kingon, Angus I.; Irving, Douglas L.

    2013-05-01

    Ohmic RF-MEMS switches hold much promise for low power wireless communication, but long-term degradation currently plagues their reliable use. Failure in these devices occurs at the contact and is complicated by the fact that the same asperities that bear the mechanical load are also important to the flow of electrical current needed for signal processing. Materials selection holds the key to overcoming the barriers that prevent widespread use. Current efforts in materials selection have been based on the material's (or alloy's) ability to resist oxidation as well as its room-temperature properties, such as hardness and electrical conductivity. No ideal solution has yet been found via this route. This may be due, in part, to the fact that the in-use changes to the local environment of the asperity are not included in the selection criteria. For example, Joule heating would be expected to raise the local temperature of the asperity and impose a non-equilibrium thermal gradient in the same region expected to respond to mechanical actuation. We propose that these conditions should be considered in the selection process, as they would be expected to alter mechanical, electrical, and chemical mechanisms in the vicinity of the surface. To this end, we simulate the actuation of an Ohmic radio frequency micro electro mechanical systems switch by using a multi-scale method to model a current-carrying asperity in contact with a polycrystalline substrate. Our method couples continuum solutions of electrical and thermal transport equations to an underlying molecular dynamics simulation. We present simulations of gold-nickel asperities and substrates in order to evaluate the influence of alloying and local order on the early stages of contact actuation. The room temperature response of these materials is compared to the response of the material when a voltage is applied. Au-Ni interactions are accounted for through modification of the existing Zhou embedded atom method

  7. Condition and residual life assessment of seamless steam pipe bends

    SciTech Connect

    Dufour, L.B.

    1995-12-01

    The majority of steam pipe bends in Dutch power plants are seamless. Reliable assessment of the condition of seamless bends after {approximately}100,000 hours of operation and beyond is a very complex and sometime frustrating procedure. Complex because external pipe forces can influence the damage and/or strain distribution in the bend. Besides, metallurgical, wall thickness and ovality variations are present anyhow, making the damage distribution in fact unknown. In accordance with a Dutch authority rule, a seamless bend is tested using a magnetic particles and investigated metallurgically with the aid of five surface replicas. Sometime more replicas are investigated and wall thickness and diameter measurements are performed as well. Occasionally, strain measurements are executed by applying capacitive strain gauges and the speckle correlation technique. In rare cases samples are taken from the first bend near the boiler outlet in order to perform isostress creep tests, allowing the determination of the condition and the residual life of other bends in the pipe systems. Based on years of experience the authors have learned that there is no single method or technique capable of assessing the condition and residual life of seamless steam pipe bends. Some experiences will be highlighted, together with recent developments in the field of quantified creep (void) damage--in order to determine inspection intervals--and the field of the speckle correlation technique.

  8. Undergraduate Certificate in Leadership Studies: An Opportunity for Seamless Learning

    ERIC Educational Resources Information Center

    Guthrie, Kathy L.; Bovio, Becka

    2014-01-01

    In working to develop undergraduate student leadership capacity, Florida State University created the Undergraduate Certificate in Leadership Studies. This program, grounded in leadership theory and framed by a seamless learning model, has been influential in development of student leadership perceptions and capacity. This article addresses the…

  9. Seamless contiguity method for parallel segmentation of remote sensing image

    NASA Astrophysics Data System (ADS)

    Wang, Geng; Wang, Guanghui; Yu, Mei; Cui, Chengling

    2015-12-01

    Seamless contiguity is the key technology for parallel segmentation of remote sensing data with large quantities. It can be effectively integrate fragments of the parallel processing into reasonable results for subsequent processes. There are numerous methods reported in the literature for seamless contiguity, such as establishing buffer, area boundary merging and data sewing. et. We proposed a new method which was also based on building buffers. The seamless contiguity processes we adopt are based on the principle: ensuring the accuracy of the boundary, ensuring the correctness of topology. Firstly, block number is computed based on data processing ability, unlike establishing buffer on both sides of block line, buffer is established just on the right side and underside of the line. Each block of data is segmented respectively and then gets the segmentation objects and their label value. Secondly, choose one block(called master block) and do stitching on the adjacent blocks(called slave block), process the rest of the block in sequence. Through the above processing, topological relationship and boundaries of master block are guaranteed. Thirdly, if the master block polygons boundaries intersect with buffer boundary and the slave blocks polygons boundaries intersect with block line, we adopt certain rules to merge and trade-offs them. Fourthly, check the topology and boundary in the buffer area. Finally, a set of experiments were conducted and prove the feasibility of this method. This novel seamless contiguity algorithm provides an applicable and practical solution for efficient segmentation of massive remote sensing image.

  10. Visual alignment technology for seamless steel pipe linearity measurement

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Xue, Ting; Zhu, Jigui; Ye, Shenghua

    2006-06-01

    Linearity measurement is the key problem in seamless steel pipe industry. For the modern industry of seamless steel pipe production, the traditional method cannot meet the needs of on-line and real-time measurement performance. Recently, visual inspection has developed rapidly and has the advantages of high speed, high precision, non-contact, automation and high manoeuvrability. So a novel approach to on-line and real-time linearity measurement of seamless steel pipe based on visual alignment technology is presented in this paper. Firstly the theory of visual alignment measuring is introduced. And then an on-line and real-time linearity measuring system, which consists of multistructured light sensor for seamless steel pipe factory of Tianjin, is invented with the technology of visual alignment. And key technologies for a visual alignment, such as the optimum design of high precision light-structured sensor, coordinates integration of multisensor, the mathematical model of visual measurement, and algorithm for ellipse center computations with high precision are studied in detail. Measurement results show that the measuring system is reasonable and can measure not only the linearity but also the coaxiality of large-scale parts.

  11. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3BN seamless nickel cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.39 Specification 3BN seamless nickel cylinders. (a) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water...

  12. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  13. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  14. 49 CFR 178.46 - Specification 3AL seamless aluminum cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3AL seamless aluminum cylinders. 178... FOR PACKAGINGS Specifications for Cylinders § 178.46 Specification 3AL seamless aluminum cylinders. (a) Size and service pressure. A DOT 3AL cylinder is a seamless aluminum cylinder with a maximum...

  15. 49 CFR 178.42 - Specification 3E seamless steel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3E seamless steel cylinders. 178.42... PACKAGINGS Specifications for Cylinders § 178.42 Specification 3E seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3E cylinder is a seamless steel cylinder with an outside diameter...

  16. 49 CFR 178.42 - Specification 3E seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3E seamless steel cylinders. 178.42... PACKAGINGS Specifications for Cylinders § 178.42 Specification 3E seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3E cylinder is a seamless steel cylinder with an outside diameter...

  17. 49 CFR 178.42 - Specification 3E seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3E seamless steel cylinders. 178.42... PACKAGINGS Specifications for Cylinders § 178.42 Specification 3E seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3E cylinder is a seamless steel cylinder with an outside diameter...

  18. 49 CFR 178.42 - Specification 3E seamless steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3E seamless steel cylinders. 178.42... PACKAGINGS Specifications for Cylinders § 178.42 Specification 3E seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3E cylinder is a seamless steel cylinder with an outside diameter...

  19. 49 CFR 178.42 - Specification 3E seamless steel cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 3E seamless steel cylinders. 178.42... FOR PACKAGINGS Specifications for Cylinders § 178.42 Specification 3E seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3E cylinder is a seamless steel cylinder with an...

  20. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  1. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  2. 49 CFR 179.500 - Specification DOT-107A * * * * seamless steel tank car tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification DOT-107A * * * * seamless steel tank...) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500 Specification DOT-107A * * * * seamless steel tank car tanks....

  3. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  4. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3AA and 3AAX seamless steel...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.37 Specification 3AA and 3AAX seamless steel... conform to the following: (1) A DOT-3AA cylinder is a seamless steel cylinder with a water...

  5. 49 CFR 178.44 - Specification 3HT seamless steel cylinders for aircraft use.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3HT seamless steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.44 Specification 3HT seamless steel cylinders for aircraft use. (a) Type, size and service pressure. A DOT 3HT cylinder is a seamless steel...

  6. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3AA and 3AAX seamless steel...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.37 Specification 3AA and 3AAX seamless steel... conform to the following: (1) A DOT-3AA cylinder is a seamless steel cylinder with a water...

  7. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  8. 49 CFR 179.500 - Specification DOT-107A * * * * seamless steel tank car tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification DOT-107A * * * * seamless steel tank...) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500 Specification DOT-107A * * * * seamless steel tank car tanks....

  9. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3B seamless steel cylinders. 178.38... PACKAGINGS Specifications for Cylinders § 178.38 Specification 3B seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3B cylinder is seamless steel cylinder with a water capacity (nominal)...

  10. 49 CFR 179.500 - Specification DOT-107A * * * * seamless steel tank car tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification DOT-107A * * * * seamless steel tank...) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500 Specification DOT-107A * * * * seamless steel tank car tanks....

  11. 49 CFR 178.44 - Specification 3HT seamless steel cylinders for aircraft use.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3HT seamless steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.44 Specification 3HT seamless steel cylinders for aircraft use. (a) Type, size and service pressure. A DOT 3HT cylinder is a seamless steel...

  12. 49 CFR 178.44 - Specification 3HT seamless steel cylinders for aircraft use.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 3HT seamless steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.44 Specification 3HT seamless steel cylinders for aircraft use. (a) Type, size and service pressure. A DOT 3HT cylinder is a seamless steel...

  13. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3AA and 3AAX seamless steel...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.37 Specification 3AA and 3AAX seamless steel... conform to the following: (1) A DOT-3AA cylinder is a seamless steel cylinder with a water...

  14. 49 CFR 179.500 - Specification DOT-107A * * * * seamless steel tank car tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification DOT-107A * * * * seamless steel tank...) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500 Specification DOT-107A * * * * seamless steel tank car tanks....

  15. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3B seamless steel cylinders. 178.38... PACKAGINGS Specifications for Cylinders § 178.38 Specification 3B seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3B cylinder is seamless steel cylinder with a water capacity (nominal)...

  16. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  17. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3A and 3AX seamless steel cylinders... FOR PACKAGINGS Specifications for Cylinders § 178.36 Specification 3A and 3AX seamless steel cylinders... conform to the following: (1) A DOT-3A cylinder is a seamless steel cylinder with a water...

  18. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3B seamless steel cylinders. 178.38... PACKAGINGS Specifications for Cylinders § 178.38 Specification 3B seamless steel cylinders. (a) Type, size, and service pressure. A DOT 3B cylinder is seamless steel cylinder with a water capacity (nominal)...

  19. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  20. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3T seamless steel cylinder. 178.45... PACKAGINGS Specifications for Cylinders § 178.45 Specification 3T seamless steel cylinder. (a) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water capacity...

  1. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 3AA and 3AAX seamless steel...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.37 Specification 3AA and 3AAX seamless steel... conform to the following: (1) A DOT-3AA cylinder is a seamless steel cylinder with a water...

  2. 49 CFR 178.44 - Specification 3HT seamless steel cylinders for aircraft use.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 3HT seamless steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.44 Specification 3HT seamless steel cylinders for aircraft use. (a) Type, size and service pressure. A DOT 3HT cylinder is a seamless steel...

  3. 76 FR 18251 - Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan Andromania

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... the imports of small and large diameter carbon and alloy seamless standard, line, and pressure pipe... of large diameter carbon and alloy seamless standard, line, and pressure pipe from Romania (65 FR... investigations: Small diameter carbon and alloy seamless standard, line, and pressure pipe and large...

  4. On-Chip High-Resolution Beam Scanner Based on Bragg Reflector Slow-Light Waveguide Amplifier and Tunable Micro-Electro-Mechanical System Vertical Cavity Surface Emitting Laser

    NASA Astrophysics Data System (ADS)

    Nakahama, Masanori; Gu, Xiaodong; Shimada, Toshikazu; Koyama, Fumio

    2012-04-01

    We propose a monolithic beam scanner consisting of a Bragg reflector slow-light waveguide amplifier and a tunable micro-electro-mechanical vertical cavity surface emitting laser. Continuous beam steering of over 30° and a narrow divergence angle of below 0.1° are predicted, which gives us a number of resolution points over 300. In addition, the modeling on saturation characteristics of a slow light amplifier shows a possibility of the maximum output power of over 10 mW.

  5. Design, fabrication and characterization of high-stroke high-aspect ratio micro electro mechanical systems deformable mirrors for adaptive optics

    NASA Astrophysics Data System (ADS)

    Fernandez Rocha, Bautista

    Adaptive optic (AO) systems for next generation of extremely large telescopes (30--50 meter diameter primary mirrors) require high-stroke (10 microns), high-order (100x100) deformable mirrors at lower-cost than current technology. The required specifications are achievable with Micro Electro Mechanical Systems (MEMS) devices fabricated with high-aspect ratio processing techniques. This dissertation will review simulation results compared with displacement measurements of actuators utilizing a white-light interferometer. It will also review different actuator designs, materials and post-processing procedures fabricated in three different high-aspect ratio processes, Microfabrica's Electrochemical Fabrication (EFAB(TM)), HT-Micro's Precision Fabrication Technology (HTPF(TM)), and Innovative Micro Technologies (IMT) fabrication process. These manufacturing processes allow high-precision multilayer fabrication and their sacrificial layer thicknesses can be specified by the designer, rather than by constraints of the fabrication process. Various types of high-stroke gold actuators for AO consisting of folded springs with rectangular and circular membranes as well as X-beam actuators supported diagonally by beams were designed, simulated, fabricated, and tested individually and as part of a continuous facesheet DM system. The design, modeling and simulation of these actuators are compared to experimental measurements of their pull-in voltages, which characterizes their stiffness and maximum stroke. Vertical parallel plate ganged actuators fabricated with the EFAB(TM) process have a calculated pull-in voltage of 95V for a 600mum size device. In contrast, the pull-in voltages for the comb-drive actuators ranged from 55V for the large actuator, to 203V for the smallest actuator. Simulations and interferometer scans of actuator designs fabricated with HT-Micro's Precision Fabrication (HTPF(TM)) two wafer bonded process with different spring supports have shown the ability of

  6. Monitoring of slope-instabilities and deformations with Micro-Electro-Mechanical-Systems (MEMS) in wireless ad-hoc Sensor Networks

    NASA Astrophysics Data System (ADS)

    Arnhardt, C.; Fernández-Steeger, T. M.; Azzam, R.

    2009-04-01

    In most mountainous regions, landslides represent a major threat to human life, properties and infrastructures. Nowadays existing landslide monitoring systems are often characterized by high efforts in terms of purchase, installation, maintenance, manpower and material. In addition (or because of this) only small areas or selective points of the endangered zone can be observed by the system. Therefore the improvement of existing and the development of new monitoring and warning systems are of high relevance. The joint project "Sensor based Landslide Early Warning Systems" (SLEWS) deals with the development of a prototypic Alarm- and Early Warning system (EWS) for different types of landslides using low-cost micro-sensors (MEMS) integrated in a wireless sensor network (WSN). Modern so called Ad-Hoc, Multi-Hop wireless sensor networks (WSN) are characterized by a self organizing and self-healing capacity of the system (autonomous systems). The network consists of numerous individual and own energy-supply operating sensor nodes, that can send data packages from their measuring devices (here: MEMS) over other nodes (Multi-Hop) to a collection point (gateway). The gateway provides the interface to central processing and data retrieval units (PC, Laptop or server) outside the network. In order to detect and monitor the different landslide processes (like fall, topple, spreading or sliding) 3D MEMS capacitive sensors made from single silicon crystals and glass were chosen to measure acceleration, tilting and altitude changes. Based on the so called MEMS (Micro-Electro-Mechanical Systems) technology, the sensors combine very small mechanical and electronic units, sensing elements and transducers on a small microchip. The mass production of such type of sensors allows low cost applications in different areas (like automobile industries, medicine, and automation technology). Apart from the small and so space saving size and the low costs another advantage is the energy

  7. Seamless Ligation Cloning Extract (SLiCE) cloning method.

    PubMed

    Zhang, Yongwei; Werling, Uwe; Edelmann, Winfried

    2014-01-01

    SLiCE (Seamless Ligation Cloning Extract) is a novel cloning method that utilizes easy to generate bacterial cell extracts to assemble multiple DNA fragments into recombinant DNA molecules in a single in vitro recombination reaction. SLiCE overcomes the sequence limitations of traditional cloning methods, facilitates seamless cloning by recombining short end homologies (15-52 bp) with or without flanking heterologous sequences and provides an effective strategy for directional subcloning of DNA fragments from bacterial artificial chromosomes or other sources. SLiCE is highly cost-effective and demonstrates the versatility as a number of standard laboratory bacterial strains can serve as sources for SLiCE extract. We established a DH10B-derived E. coli strain expressing an optimized λ prophage Red recombination system, termed PPY, which facilitates SLiCE with very high efficiencies. PMID:24395368

  8. Seamless Synthetic Aperture Radar Archive for Interferometry Analysis

    NASA Astrophysics Data System (ADS)

    Baker, S.; Baru, C.; Bryson, G.; Buechler, B.; Crosby, C.; Fielding, E.; Meertens, C.; Nicoll, J.; Youn, C.

    2014-11-01

    The NASA Advancing Collaborative Connections for Earth System Science (ACCESS) seamless synthetic aperture radar (SAR) archive (SSARA) project is a collaboration between UNAVCO, the Alaska Satellite Facility (ASF), the Jet Propulsion Laboratory (JPL), and OpenTopography at the San Diego Supercomputer Center (SDSC) to design and implement a seamless distributed access system for SAR data and derived interferometric SAR (InSAR) data products. A unified application programming interface (API) has been created to search the SAR archives at ASF and UNAVCO, 30 and 90-m SRTM DEM data available through OpenTopography, and tropospheric data from the NASA OSCAR project at JPL. The federated query service provides users a single access point to search for SAR granules, InSAR pairs, and corresponding DEM and tropospheric data products from the four archives, as well as the ability to search and download pre-processed InSAR products from ASF and UNAVCO.

  9. Reconciling vertical datum for seamless hydrographic data integration

    NASA Astrophysics Data System (ADS)

    Zhang, Lihua; Zhu, Qing; Bao, Jingyang; Liu, Yanchun

    2005-10-01

    A reconciling vertical datum is fundamental for the seamless integration of multi-source hydrographic data. Based on the analyses of the current vertical datums used for hydrograph, this paper presents a new scheme to create a reconciling vertical datum. To resolve the problem of integrating geospatial data referred to different vertical surfaces, an ellipsoidal datum is adopted as a universal master reference surface; A (quasi) hydroid is defined and the method which determine the quasi hydroid is then introduced; The quasi geoid and hydroid are adopted as client datums. On the basis of the determination between the master datum and the client datums, the data derived from different datums can be aggregated seamlessly and discretionarily. Two methods which can transform depth data from one vertical datum to another when quickly aggregating hydrographic data are suggested, one is identical transformation parameters based on hierarchical grid, and the other is interpolation based on position.

  10. Seamless Synthetic Aperture Radar Archive for Interferometry Analysis

    NASA Astrophysics Data System (ADS)

    Baker, S.; Meertens, C. M.; Phillips, D. A.; Crosby, C.; Fielding, E. J.; Nicoll, J.; Bryson, G.; Buechler, B.; Baru, C.

    2012-12-01

    The NASA Advancing Collaborative Connections for Earth System Science (ACCESS) Seamless Synthetic Aperture Radar (SAR) Archive (SSARA) project is a 2-year collaboration between UNAVCO/WInSAR, the Alaska Satellite Facility (ASF), the Jet Propulsion Laboratory (JPL), and the San Diego Supercomputer Center (SDSC) to design and implement a seamless distributed access system for SAR data and derived data products (i.e. terrain corrected interferograms). A seamless SAR archive increases the accessibility and the utility of SAR science data to solid Earth and cryospheric science researchers. Building on the established webs services and APIs at UNAVCO and ASF, the SSARA project will provide simple web services tools to seamlessly and effectively exchange and share space- and airborne SAR metadata, archived SAR data, and on-demand derived products between the distributed archives and individual users. Development of standard formats for data products and new QC/QA definitions will be implemented to streamline data usage and enable advanced query capabilities. The new ACCESS-developed tools will help overcome the obstacles of heterogeneous archive access protocols and data formats, data provider access policy constraints, and will also enable interoperability with key information technology development systems such as the NASA/JPL QuakeSim and ARIA projects, which provide higher level resources for geodetic data processing, data assimilation and modeling, and integrative analysis for scientific research and hazards applications. The SSARA project will significantly enhance mature IT capabilities at ASF's NASA-supported DAAC, the GEO Supersites archive, supported operationally by UNAVCO, and UNAVCO's WInSAR and EarthScope SAR archives that are supported by NASA, NSF, and the USGS in close collaboration with ESA/ESRIN.

  11. A seamless ubiquitous emergency medical service for crisis situations.

    PubMed

    Lin, Bor-Shing

    2016-04-01

    In crisis situations, a seamless ubiquitous communication is necessary to provide emergency medical service to save people's lives. An excellent prehospital emergency medicine provides immediate medical care to increase the survival rate of patients. On their way to the hospital, ambulance personnel must transmit real-time and uninterrupted patient information to the hospital to apprise the physician of the situation and provide options to the ambulance personnel. In emergency and crisis situations, many communication channels can be unserviceable because of damage to equipment or loss of power. Thus, data transmission over wireless communication to achieve uninterrupted network services is a major obstacle. This study proposes a mobile middleware for cognitive radio (CR) for improving the wireless communication link. CRs can sense their operating environment and optimize the spectrum usage so that the mobile middleware can integrate the existing wireless communication systems with a seamless communication service in heterogeneous network environments. Eventually, the proposed seamless mobile communication middleware was ported into an embedded system, which is compatible with the actual network environment without the need for changing the original system architecture. PMID:26796352

  12. Private Graphs - Access Rights on Graphs for Seamless Navigation

    NASA Astrophysics Data System (ADS)

    Dorner, W.; Hau, F.; Pagany, R.

    2016-06-01

    After the success of GNSS (Global Navigational Satellite Systems) and navigation services for public streets, indoor seems to be the next big development in navigational services, relying on RTLS - Real Time Locating Services (e.g. WIFI) and allowing seamless navigation. In contrast to navigation and routing services on public streets, seamless navigation will cause an additional challenge: how to make routing data accessible to defined users or restrict access rights for defined areas or only to parts of the graph to a defined user group? The paper will present case studies and data from literature, where seamless and especially indoor navigation solutions are presented (hospitals, industrial complexes, building sites), but the problem of restricted access rights was only touched from a real world, but not a technical perspective. The analysis of case studies will show, that the objective of navigation and the different target groups for navigation solutions will demand well defined access rights and require solutions, how to make only parts of a graph to a user or application available to solve a navigational task. The paper will therefore introduce the concept of private graphs, which is defined as a graph for navigational purposes covering the street, road or floor network of an area behind a public street and suggest different approaches how to make graph data for navigational purposes available considering access rights and data protection, privacy and security issues as well.

  13. 77 FR 50465 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... carbon and alloy seamless standard, line and pressure pipe (small diameter seamless pipe) from Romania.\\1... Order: Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania... Corporation (the petitioner) alleged that AMTP made sales of small diameter seamless pipe from Romania...

  14. 78 FR 41369 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... on certain small diameter carbon and alloy seamless standard, line and pressure pipe (small diameter... diameter seamless pipe. The small diameter seamless pipe subject to the order is currently classifiable... small diameter seamless pipe from Romania entered, or withdrawn from warehouse, for......

  15. Monitoring of slope-instabilities and deformations with Micro-Electro-Mechanical-Systems (MEMS) in wireless ad-hoc Sensor Networks

    NASA Astrophysics Data System (ADS)

    Arnhardt, C.; Fernández-Steeger, T. M.; Azzam, R.

    2009-04-01

    In most mountainous regions, landslides represent a major threat to human life, properties and infrastructures. Nowadays existing landslide monitoring systems are often characterized by high efforts in terms of purchase, installation, maintenance, manpower and material. In addition (or because of this) only small areas or selective points of the endangered zone can be observed by the system. Therefore the improvement of existing and the development of new monitoring and warning systems are of high relevance. The joint project "Sensor based Landslide Early Warning Systems" (SLEWS) deals with the development of a prototypic Alarm- and Early Warning system (EWS) for different types of landslides using low-cost micro-sensors (MEMS) integrated in a wireless sensor network (WSN). Modern so called Ad-Hoc, Multi-Hop wireless sensor networks (WSN) are characterized by a self organizing and self-healing capacity of the system (autonomous systems). The network consists of numerous individual and own energy-supply operating sensor nodes, that can send data packages from their measuring devices (here: MEMS) over other nodes (Multi-Hop) to a collection point (gateway). The gateway provides the interface to central processing and data retrieval units (PC, Laptop or server) outside the network. In order to detect and monitor the different landslide processes (like fall, topple, spreading or sliding) 3D MEMS capacitive sensors made from single silicon crystals and glass were chosen to measure acceleration, tilting and altitude changes. Based on the so called MEMS (Micro-Electro-Mechanical Systems) technology, the sensors combine very small mechanical and electronic units, sensing elements and transducers on a small microchip. The mass production of such type of sensors allows low cost applications in different areas (like automobile industries, medicine, and automation technology). Apart from the small and so space saving size and the low costs another advantage is the energy

  16. Resonant mode controllers for launch vehicle applications

    NASA Technical Reports Server (NTRS)

    Schreiner, Ken E.; Roth, Mary Ellen

    1992-01-01

    Electro-mechanical actuator (EMA) systems are currently being investigated for the National Launch System (NLS) as a replacement for hydraulic actuators due to the large amount of manpower and support hardware required to maintain the hydraulic systems. EMA systems in weight sensitive applications, such as launch vehicles, have been limited to around 5 hp due to system size, controller efficiency, thermal management, and battery size. Presented here are design and test data for an EMA system that competes favorably in weight and is superior in maintainability to the hydraulic system. An EMA system uses dc power provided by a high energy density bipolar lithium thionyl chloride battery, with power conversion performed by low loss resonant topologies, and a high efficiency induction motor controlled with a high performance field oriented controller to drive a linear actuator.

  17. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    Frederick, D. K.; Lashmet, P. K.; Moyer, W. R.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

    1973-01-01

    The following tasks related to the design, construction, and evaluation of a mobile planetary vehicle for unmanned exploration of Mars are discussed: (1) design and construction of a 0.5 scale dynamic vehicle; (2) mathematical modeling of vehicle dynamics; (3) experimental 0.4 scale vehicle dynamics measurements and interpretation; (4) vehicle electro-mechanical control systems; (5) remote control systems; (6) collapsibility and deployment concepts and hardware; (7) design, construction and evaluation of a wheel with increased lateral stiffness, (8) system design optimization; (9) design of an on-board computer; (10) design and construction of a laser range finder; (11) measurement of reflectivity of terrain surfaces; (12) obstacle perception by edge detection; (13) terrain modeling based on gradients; (14) laser scan systems; (15) path selection system simulation and evaluation; (16) gas chromatograph system concepts; (17) experimental chromatograph separation measurements and chromatograph model improvement and evaluation.

  18. Fusion Based Seamless Mosaic for Remote Sensing Images

    NASA Astrophysics Data System (ADS)

    Lu, Ting; Li, Shutao; Fu, Wei

    2014-11-01

    A fusion based seamless mosaic method for stitching remote sensing images is introduced in this paper. The proposed method focuses on one major problem in the process of mosaic: how to generate visually pleasant stitching result in the cases of misalignment, global and local intensity differences between images. First, two partially overlapped images are decomposed into high-frequency components and low-frequency components with Gaussian low-pass filter. Second, by considering the information characteristics contained in both separated components, different mosaic schemes are designed to accomplish stitching process accordingly. For the low-frequency components consisting of coarse shape and illumination information, two-dimension weighted blending rule is utilized to achieve smoothing transition. For the high-frequency components including rich details, an improved seam searching strategy based on dynamic programming is introduced. With the obtained stitching seam guiding the stitching process, visible structural break can be avoided. Finally, the mosaic result is produced by linearly composing both stitching results of different components together. Experimental results demonstrate the effectiveness of the proposed method in generating seamless mosaic results without introducing any unexpected blurring or artifacts.

  19. Natural and seamless image composition with color control.

    PubMed

    Yang, Wenxian; Zheng, Jianmin; Cai, Jianfei; Rahardja, Susanto; Chen, Chang Wen

    2009-11-01

    While the state-of-the-art image composition algorithms subtly handle the object boundary to achieve seamless image copy-and-paste, it is observed that they are unable to preserve the color fidelity of the source object, often require quite an amount of user interactions, and often fail to achieve realism when there exists salient discrepancy between the background textures in the source and destination images. These observations motivate our research towards color controlled natural and seamless image composition with least user interactions. In particular, based on the Poisson image editing framework, we first propose a variational model that considers both the gradient constraint and the color fidelity. The proposed model allows users to control the coloring effect caused by gradient domain fusion. Second, to have less user interactions, we propose a distance-enhanced random walks algorithm, through which we avoid the necessity of accurate image segmentation while still able to highlight the foreground object. Third, we propose a multiresolution framework to perform image compositions at different subbands so as to separate the texture and color components to simultaneously achieve smooth texture transition and desired color control. The experimental results demonstrate that our proposed framework achieves better and more realistic results for images with salient background color or texture differences, while providing comparable results as the state-of-the-art algorithms for images without the need of preserving the object color fidelity and without significant background texture discrepancy. PMID:19596637

  20. Summary of STARNet: Seamless Transitions and (Re)admissions Network.

    PubMed

    Auger, Katherine A; Simon, Tamara D; Cooperberg, David; Gay, James; Kuo, Dennis Z; Saysana, Michele; Stille, Christopher J; Fisher, Erin Stucky; Wallace, Sowdhamini; Berry, Jay; Coghlin, Daniel; Jhaveri, Vishu; Kairys, Steven; Logsdon, Tina; Shaikh, Ulfat; Srivastava, Rajendu; Starmer, Amy J; Wilkins, Victoria; Shen, Mark W

    2015-01-01

    The Seamless Transitions and (Re)admissions Network (STARNet) met in December 2012 to synthesize ongoing hospital-to-home transition work, discuss goals, and develop a plan to centralize transition information in the future. STARNet participants consisted of experts in the field of pediatric hospital medicine quality improvement and research, and included physicians and key stakeholders from hospital groups, private payers, as well as representatives from current transition collaboratives. In this report, we (1) review the current knowledge regarding hospital-to-home transitions; (2) outline the challenges of measuring and reducing readmissions; and (3) highlight research gaps and list potential measures for transition quality. STARNet met with the support of the American Academy of Pediatrics' Quality Improvement Innovation Networks and the Section on Hospital Medicine. PMID:25489017

  1. Summary of STARNet: Seamless Transitions and (Re)admissions Network

    PubMed Central

    Simon, Tamara D.; Cooperberg, David; Gay, James; Kuo, Dennis Z.; Saysana, Michele; Stille, Christopher J.; Fisher, Erin Stucky; Wallace, Sowdhamini; Berry, Jay; Coghlin, Daniel; Jhaveri, Vishu; Kairys, Steven; Logsdon, Tina; Shaikh, Ulfat; Srivastava, Rajendu; Starmer, Amy J.; Wilkins, Victoria; Shen, Mark W.

    2015-01-01

    The Seamless Transitions and (Re)admissions Network (STARNet) met in December 2012 to synthesize ongoing hospital-to-home transition work, discuss goals, and develop a plan to centralize transition information in the future. STARNet participants consisted of experts in the field of pediatric hospital medicine quality improvement and research, and included physicians and key stakeholders from hospital groups, private payers, as well as representatives from current transition collaboratives. In this report, we (1) review the current knowledge regarding hospital-to-home transitions; (2) outline the challenges of measuring and reducing readmissions; and (3) highlight research gaps and list potential measures for transition quality. STARNet met with the support of the American Academy of Pediatrics’ Quality Improvement Innovation Networks and the Section on Hospital Medicine. PMID:25489017

  2. Supporting Seamless Mobility for P2P Live Streaming

    PubMed Central

    Kim, Eunsam; Kim, Sangjin; Lee, Choonhwa

    2014-01-01

    With advent of various mobile devices with powerful networking and computing capabilities, the users' demand to enjoy live video streaming services such as IPTV with mobile devices has been increasing rapidly. However, it is challenging to get over the degradation of service quality due to data loss caused by the handover. Although many handover schemes were proposed at protocol layers below the application layer, they inherently suffer from data loss while the network is being disconnected during the handover. We therefore propose an efficient application-layer handover scheme to support seamless mobility for P2P live streaming. By simulation experiments, we show that the P2P live streaming system with our proposed handover scheme can improve the playback continuity significantly compared to that without our scheme. PMID:24977171

  3. Water Intercalation for Seamless, Electrically Insulating, and Thermally Transparent Interfaces.

    PubMed

    Wang, Yanlei; Xu, Zhiping

    2016-01-27

    The interface between functional nanostructures and host substrates is of pivotal importance in the design of their nanoelectronic applications because it conveys energy and information between the device and environment. We report here an interface-engineering approach to establish a seamless, electrically insulating, while thermally transparent interface between graphene and metal substrates by introducing water intercalation. Molecular dynamics simulations and first-principles calculations are performed to demonstrate this concept of design, showing that the presence of the interfacial water layer helps to unfold wrinkles formed in the graphene membrane, insulate the electronic coupling between graphene and the substrate, and elevate the interfacial thermal conductance. The findings here lay the ground for a new class of nanoelectronic setups through interface engineering, which could lead to significant improvement in the performance of nanodevices, such as the field-effect transistors. PMID:26720217

  4. Method and apparatus for providing a seamless tiled display

    NASA Technical Reports Server (NTRS)

    Johnson, Michael J. (Inventor); Dubin, Matthew B. (Inventor)

    2002-01-01

    A display for producing a seamless composite image from at least two discrete images. The display includes one or more projectors for projecting each of the discrete images separately onto a screen such that at least one of the discrete images overlaps at least one other of the discrete images by more than 25 percent. The amount of overlap that is required to reduce the seams of the composite image to an acceptable level over a predetermined viewing angle depends on a number of factors including the field-of-view and aperture size of the projectors, the screen gain profile, etc. For rear-projection screens and some front projection screens, an overlap of more than 25 percent is acceptable.

  5. Supporting seamless mobility for P2P live streaming.

    PubMed

    Kim, Eunsam; Kim, Sangjin; Lee, Choonhwa

    2014-01-01

    With advent of various mobile devices with powerful networking and computing capabilities, the users' demand to enjoy live video streaming services such as IPTV with mobile devices has been increasing rapidly. However, it is challenging to get over the degradation of service quality due to data loss caused by the handover. Although many handover schemes were proposed at protocol layers below the application layer, they inherently suffer from data loss while the network is being disconnected during the handover. We therefore propose an efficient application-layer handover scheme to support seamless mobility for P2P live streaming. By simulation experiments, we show that the P2P live streaming system with our proposed handover scheme can improve the playback continuity significantly compared to that without our scheme. PMID:24977171

  6. Developing a Seamless Science Education Program (K-Graduate School)

    NASA Astrophysics Data System (ADS)

    Hyde, Truell; Smith, Bernard; Matthews, Lorin; Carmona-Reyes, Jorge

    The production of STEM personnel has declined precipitously over the past several decades. This is threatening not only the international economy but also the world's access to space. It is imperative that scientists within the current space physics community develop programs at the K-12 level able to spark an interest in science while providing an understanding that a career in science can be rewarding both professionally and financially. Ideally such programs should mesh seamlessly with current university undergraduate and graduate programs, easing the student's transition from one to the other. This goal is the primary driver behind CASPER's current outreach program. CASPER programs supporting this paradigm will be discussed along with related funding opportunities such as the Department of Education GearUp Program and the NSF REU and RET programs.

  7. A New Seamless Transfer Control Strategy of the Microgrid

    PubMed Central

    Zhang, Zhaoyun; Chen, Wei; Zhang, Zhe

    2014-01-01

    A microgrid may operate under two typical modes; the seamless transfer control of the microgrid is very important. The mode conversion controller is installed in microgrid and the control logic of master power is optimized for microgrid mode conversion. In the proposed scheme, master power is very important. The master-power is under the PQ control when microgrid is under grid-connected. And it is under V/F control when the microgrid is under islanding. The microgrid mode controller is used to solve the planned conversion. Three types of conversion are simulated in this paper. The simulation results show the correctness and validity of the mode control scheme. Finally, the implementation and application of the operation and control device are described. PMID:24967431

  8. 75 FR 71146 - Seamless Refined Copper Pipe and Tube From China and Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... publishing the notice in the Federal Register of June 11, 2010 (75 FR 33330). The hearing was held in... COMMISSION Seamless Refined Copper Pipe and Tube From China and Mexico Determinations On the basis of the... seamless refined copper pipe and tube (``SRC pipe and tube'') from China and Mexico provided for...

  9. 77 FR 54926 - Certain Seamless Carbon and Alloy Steel; Standard, Line, and Pressure Pipe From Germany

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... FR 19711) and determined on July 6, 2012, that it would conduct an expedited review (77 FR 42763... COMMISSION Certain Seamless Carbon and Alloy Steel; Standard, Line, and Pressure Pipe From Germany... U.S.C. 1675(c)), that revocation of the antidumping duty order on certain seamless carbon and...

  10. 75 FR 69125 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-10

    ..., and by publishing the notice in the Federal Register on May 11, 2010 (75 FR 26273). The hearing was... COMMISSION Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China Determination... States is threatened with material injury by reason of imports from China of certain seamless carbon...

  11. Federated query services provided by the Seamless SAR Archive project

    NASA Astrophysics Data System (ADS)

    Baker, S.; Bryson, G.; Buechler, B.; Meertens, C. M.; Crosby, C. J.; Fielding, E. J.; Nicoll, J.; Youn, C.; Baru, C.

    2013-12-01

    The NASA Advancing Collaborative Connections for Earth System Science (ACCESS) seamless synthetic aperture radar (SAR) archive (SSARA) project is a 2-year collaboration between UNAVCO, the Alaska Satellite Facility (ASF), the Jet Propulsion Laboratory (JPL), and OpenTopography at the San Diego Supercomputer Center (SDSC) to design and implement a seamless distributed access system for SAR data and derived data products (i.e. interferograms). A major milestone for the first year of the SSARA project was a unified application programming interface (API) for SAR data search and results at ASF and UNAVCO (WInSAR and EarthScope data archives) through the use of simple web services. A federated query service was developed using the unified APIs, providing users a single search interface for both archives (http://www.unavco.org/ws/brokered/ssara/sar/search). A command line client that utilizes this new service is provided as an open source utility for the community on GitHub (https://github.com/bakerunavco/SSARA). Further API development and enhancements added more InSAR specific keywords and quality control parameters (Doppler centroid, faraday rotation, InSAR stack size, and perpendicular baselines). To facilitate InSAR processing, the federated query service incorporated URLs for DEM (from OpenTopography) and tropospheric corrections (from the JPL OSCAR service) in addition to the URLs for SAR data. This federated query service will provide relevant QC metadata for selecting pairs of SAR data for InSAR processing and all the URLs necessary for interferogram generation. Interest from the international community has prompted an effort to incorporate other SAR data archives (the ESA Virtual Archive 4 and the DLR TerraSAR-X_SSC Geohazard Supersites and Natural Laboratories collections) into the federated query service which provide data for researchers outside the US and North America.

  12. Toward seamless weather-climate and environmental prediction

    NASA Astrophysics Data System (ADS)

    Brunet, Gilbert

    2016-04-01

    Over the last decade or so, predicting the weather, climate and atmospheric composition has emerged as one of the most important areas of scientific endeavor. This is partly because the remarkable increase in skill of current weather forecasts has made society more and more dependent on them day to day for a whole range of decision making. And it is partly because climate change is now widely accepted and the realization is growing rapidly that it will affect every person in the world profoundly, either directly or indirectly. One of the important endeavors of our societies is to remain at the cutting-edge of modelling and predicting the evolution of the fully coupled environmental system: atmosphere (weather and composition), oceans, land surface (physical and biological), and cryosphere. This effort will provide an increasingly accurate and reliable service across all the socio-economic sectors that are vulnerable to the effects of adverse weather and climatic conditions, whether now or in the future. This emerging challenge was at the center of the World Weather Open Science Conference (Montreal, 2014).The outcomes of the conference are described in the World Meteorological Organization (WMO) book: Seamless Prediction of the Earth System: from Minutes to Months, (G. Brunet, S. Jones, P. Ruti Eds., WMO-No. 1156, 2015). It is freely available on line at the WMO website. We will discuss some of the outcomes of the conference for the WMO World Weather Research Programme (WWRP) and Global Atmospheric Watch (GAW) long term goals and provide examples of seamless modelling and prediction across a range of timescales at convective and sub-kilometer scales for regional coupled forecasting applications at Environment and Climate Change Canada (ECCC).

  13. Whacked and Rab35 polarize dynein-motor-complex-dependent seamless tube growth.

    PubMed

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S

    2012-04-01

    Seamless tubes form intracellularly without cell-cell or autocellular junctions. Such tubes have been described across phyla, but remain mysterious despite their simple architecture. In Drosophila, seamless tubes are found within tracheal terminal cells, which have dozens of branched protrusions extending hundreds of micrometres. We find that mutations in multiple components of the dynein motor complex block seamless tube growth, raising the possibility that the lumenal membrane forms through minus-end-directed transport of apical membrane components along microtubules. Growth of seamless tubes is polarized along the proximodistal axis by Rab35 and its apical membrane-localized GAP, Whacked. Strikingly, loss of whacked (or constitutive activation of Rab35) leads to tube overgrowth at terminal cell branch tips, whereas overexpression of Whacked (or dominant-negative Rab35) causes formation of ectopic tubes surrounding the terminal cell nucleus. Thus, vesicle trafficking has key roles in making and shaping seamless tubes. PMID:22407366

  14. Method of converting an existing vehicle powertrain to a hybrid powertrain system

    DOEpatents

    Reed, Jr., Richard G.; Boberg, Evan S.; Lawrie, Robert E.; Castaing, Francois J.

    2001-12-25

    A method of converting an existing vehicle powertrain including a manual transmission to a hybrid powertrain system with an automated powertrain transmission. The first step in the method of attaching a gear train housing to a housing of said manual transmission, said gear train housing receiving as end of drive shaft of said transmission and rotatably supporting a gear train assembly. Secondly, mounting an electric motor/generator to said gear train housing and attaching a motor/generator drive shaft of said electric motor/generator to said gear train assembly. Lastly, connecting an electro-mechanical clutch actuator to a friction clutch mechanism of said manual transmission.

  15. What Seams Do We Remove in Mobile-Assisted Seamless Learning? A Critical Review of the Literature

    ERIC Educational Resources Information Center

    Wong, Lung-Hsiang; Looi, Chee-Kit

    2011-01-01

    Seamless learning refers to the seamless integration of the learning experiences across various dimensions including formal and informal learning contexts, individual and social learning, and physical world and cyberspace. Inspired by the exposition by Chan et al. (2006) on the seamless learning model supported by the setting of one or more mobile…

  16. 77 FR 56809 - Certain Small Diameter Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... Diameter Seamless Carbon and Alloy Steel Standard, Line and Pressure Pipe From Germany, 60 FR 39704 (August...\\ \\3\\ See Certain Small Diameter Seamless Carbon and Alloy Standard, Line, and Pressure Pipe From... International Trade Administration Certain Small Diameter Seamless Carbon and Alloy Steel Standard, Line,...

  17. 77 FR 67336 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ... order on certain small diameter carbon and alloy seamless standard, line and pressure pipe from Romania... diameter carbon and alloy seamless standard, line and pressure pipe from Romania. See Certain Small... Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania, 65 FR 48963 (August...

  18. 78 FR 63164 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... antidumping duty order on certain small diameter carbon and alloy seamless standard, line and pressure pipe... small diameter carbon and alloy seamless standard, line and pressure pipe from Romania.\\1\\ We invited... (the Act). \\1\\ See Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure...

  19. 76 FR 62762 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Japan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... Pipe From Japan; Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From... alloy seamless standard, line and pressure pipe (``large diameter pipe'') from Japan and certain small diameter carbon and alloy seamless standard, line and pressure pipe (``small diameter pipe'')......

  20. Seamless tube shape is constrained by endocytosis-dependent regulation of active Moesin.

    PubMed

    Schottenfeld-Roames, Jodi; Rosa, Jeffrey B; Ghabrial, Amin S

    2014-08-01

    Most tubes have seams (intercellular or autocellular junctions that seal membranes together into a tube), but "seamless" tubes also exist. In Drosophila, stellate-shaped tracheal terminal cells make seamless tubes, with single branches running through each of dozens of cellular extensions. We find that mutations in braided impair terminal cell branching and cause formation of seamless tube cysts. We show that braided encodes Syntaxin7 and that cysts also form in cells deficient for other genes required either for membrane scission (shibire) or for early endosome formation (Rab5, Vps45, and Rabenosyn-5). These data define a requirement for early endocytosis in shaping seamless tube lumens. Importantly, apical proteins Crumbs and phospho-Moesin accumulate to aberrantly high levels in braided terminal cells. Overexpression of either Crumbs or phosphomimetic Moesin induced lumenal cysts and decreased terminal branching. Conversely, the braided seamless tube cyst phenotype was suppressed by mutations in crumbs or Moesin. Indeed, mutations in Moesin dominantly suppressed seamless tube cyst formation and restored terminal branching. We propose that early endocytosis maintains normal steady-state levels of Crumbs, which recruits apical phosphorylated (active) Moe, which in turn regulates seamless tube shape through modulation of cortical actin filaments. PMID:25065756

  1. Estimation after subpopulation selection in adaptive seamless trials.

    PubMed

    Kimani, Peter K; Todd, Susan; Stallard, Nigel

    2015-08-15

    During the development of new therapies, it is not uncommon to test whether a new treatment works better than the existing treatment for all patients who suffer from a condition (full population) or for a subset of the full population (subpopulation). One approach that may be used for this objective is to have two separate trials, where in the first trial, data are collected to determine if the new treatment benefits the full population or the subpopulation. The second trial is a confirmatory trial to test the new treatment in the population selected in the first trial. In this paper, we consider the more efficient two-stage adaptive seamless designs (ASDs), where in stage 1, data are collected to select the population to test in stage 2. In stage 2, additional data are collected to perform confirmatory analysis for the selected population. Unlike the approach that uses two separate trials, for ASDs, stage 1 data are also used in the confirmatory analysis. Although ASDs are efficient, using stage 1 data both for selection and confirmatory analysis introduces selection bias and consequently statistical challenges in making inference. We will focus on point estimation for such trials. In this paper, we describe the extent of bias for estimators that ignore multiple hypotheses and selecting the population that is most likely to give positive trial results based on observed stage 1 data. We then derive conditionally unbiased estimators and examine their mean squared errors for different scenarios. PMID:25903293

  2. Seamless Insertion of Pulmonary Nodules in Chest CT Images.

    PubMed

    Pezeshk, Aria; Sahiner, Berkman; Zeng, Rongping; Wunderlich, Adam; Chen, Weijie; Petrick, Nicholas

    2015-12-01

    The availability of large medical image datasets is critical in many applications, such as training and testing of computer-aided diagnosis systems, evaluation of segmentation algorithms, and conducting perceptual studies. However, collection of data and establishment of ground truth for medical images are both costly and difficult. To address this problem, we are developing an image blending tool that allows users to modify or supplement existing datasets by seamlessly inserting a lesion extracted from a source image into a target image. In this study, we focus on the application of this tool to pulmonary nodules in chest CT exams. We minimize the impact of user skill on the perceived quality of the composite image by limiting user involvement to two simple steps: the user first draws a casual boundary around a nodule in the source, and, then, selects the center of desired insertion area in the target. We demonstrate the performance of our system on clinical samples, and report the results of a reader study evaluating the realism of inserted nodules compared to clinical nodules. We further evaluate our image blending techniques using phantoms simulated under different noise levels and reconstruction filters. Specifically, we compute the area under the ROC curve of the Hotelling observer (HO) and noise power spectrum of regions of interest enclosing native and inserted nodules, and compare the detectability, noise texture, and noise magnitude of inserted and native nodules. Our results indicate the viability of our approach for insertion of pulmonary nodules in clinical CT images. PMID:26080378

  3. Seamless insertion of real pulmonary nodules in chest CT exams

    NASA Astrophysics Data System (ADS)

    Pezeshk, Aria; Sahiner, Berkman; Zeng, Rongping; Wunderlich, Adam; Chen, Weijie; Petrick, Nicholas

    2014-03-01

    The availability of large medical image datasets is critical in many applications such as training and testing of computer aided diagnosis (CAD) systems, evaluation of segmentation algorithms, and conducting perceptual studies. However, collection of large repositories of clinical images is hindered by the high cost and difficulties associated with both the accumulation of data and establishment of the ground truth. To address this problem, we are developing an image blending tool that allows users to modify or supplement existing datasets by seamlessly inserting a real lesion extracted from a source image into a different location on a target image. In this study we focus on the application of this tool to pulmonary nodules in chest CT exams. We minimize the impact of user skill on the perceived quality of the blended image by limiting user involvement to two simple steps: the user first draws a casual boundary around the nodule of interest in the source, and then selects the center of desired insertion area in the target. We demonstrate examples of the performance of the proposed system on samples taken from the Lung Image Database Consortium (LIDC) dataset, and compare the noise power spectrum (NPS) of blended nodules versus that of native nodules in simulated phantoms.

  4. Characterizing seamless ligation cloning extract for synthetic biological applications.

    PubMed

    Messerschmidt, Katrin; Hochrein, Lena; Dehm, Daniel; Schulz, Karina; Mueller-Roeber, Bernd

    2016-09-15

    Synthetic biology aims at designing and engineering organisms. The engineering process typically requires the establishment of suitable DNA constructs generated through fusion of multiple protein coding and regulatory sequences. Conventional cloning techniques, including those involving restriction enzymes and ligases, are often of limited scope, in particular when many DNA fragments must be joined or scar-free fusions are mandatory. Overlap-based-cloning methods have the potential to overcome such limitations. One such method uses seamless ligation cloning extract (SLiCE) prepared from Escherichia coli cells for straightforward and efficient in vitro fusion of DNA fragments. Here, we systematically characterized extracts prepared from the unmodified E. coli strain DH10B for SLiCE-mediated cloning and determined DNA sequence-associated parameters that affect cloning efficiency. Our data revealed the virtual absence of length restrictions for vector backbone (up to 13.5 kbp) and insert (90 bp to 1.6 kbp). Furthermore, differences in GC content in homology regions are easily tolerated and the deletion of unwanted vector sequences concomitant with targeted fragment insertion is straightforward. Thus, SLiCE represents a highly versatile DNA fusion method suitable for cloning projects in virtually all molecular and synthetic biology projects. PMID:27311554

  5. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Type, size and service pressure. A DOT 3BN cylinder is a seamless nickel cylinder with a water capacity... ends may be flattened to within one inch of each end of the reduced section. (iii) When size...

  6. Method and apparatus for an optical function generator for seamless tiled displays

    NASA Technical Reports Server (NTRS)

    Johnson, Michael (Inventor); Chen, Chung-Jen (Inventor)

    2004-01-01

    Producing seamless tiled images from multiple displays includes measuring a luminance profile of each of the displays, computing a desired luminance profile for each of the displays, and determining a spatial gradient profile of each of the displays based on the measured luminance profile and the computed desired luminance profile. The determined spatial gradient profile is applied to a spatial filter to be inserted into each of the displays to produce the seamless tiled display image.

  7. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    NASA Technical Reports Server (NTRS)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  8. Hatch: Moving towards seamless database protocols for ecological data

    NASA Astrophysics Data System (ADS)

    Fremier, A. K.; Blair, C.; Smith, S.; Weigel, D.; Newsom, M. A.

    2013-12-01

    Data collection and ecological processes do not occur at similar scales. Monitoring our environment, therefore, requires research approaches that integrate data across spatial and temporal scales. Despite the enormous amount of data being collected annually, many government agencies are only now beginning to build coordinated data management systems. With efficient data flows and coded analysis tools, researchers will be better prepared to quickly answer key ecological questions across datasets. In this project, we designed an online platform for seamless data management, called Hatch. Our aim is to improve database protocols and data access to allow timely analysis of existing data, across time and space. Hatch is being developed for ecological monitoring of stream ecosystems in the Methow River basin in Washington State; however, the platform is general enough for managing multiple forms of database types. Hatch currently applies both a schema and schema-less database structure to link data collection events. It applies data standards developed and accepted across the Columbia River Basin. Initial data capture is driven by data needs for a mechanism-based model of ecosystem processes (namely periphyton production). Input data files, both past and current flows, are validated and stored along with metadata. Data search tools are being designed in accordance with data sharing agreements with appropriate security. The goal of Hatch is to defragment the analysis workspace by integrating data capture, search and analysis. Hatch helps researchers capture, search and analyze data in an online, flexible platform while conforming to project a specific schema. With less fragmented database protocols, scientists will be better prepared to efficiently answer scientific questions at relevant ecological scales.

  9. Megacities, air quality and climate: Seamless prediction approach

    NASA Astrophysics Data System (ADS)

    Baklanov, Alexander; Molina, Luisa T.; Gauss, Michael

    2016-04-01

    The rapid urbanization and growing number of megacities and urban complexes requires new types of research and services that make best use of science and available technology. With an increasing number of humans now living in urban sprawls, there are urgent needs of examining what the rising number of megacities means for air pollution, local climate and the effects these changes have on global climate. Such integrated studies and services should assist cities in facing hazards such as storm surge, flooding, heat waves, and air pollution episodes, especially in changing climates. While important advances have been made, new interdisciplinary research studies are needed to increase our understanding of the interactions between emissions, air quality, and regional and global climates. Studies need to address both basic and applied research and bridge the spatial and temporal scales connecting local emissions and air pollution and local weather, global atmospheric chemistry and climate. This paper reviews the current status of studies of the complex interactions between climate, air quality and megacities, and identifies the main gaps in our current knowledge as well as further research needs in this important field of research. Highlights • Climate, air quality and megacities interactions: gaps in knowledge, research needs. • Urban hazards: pollution episodes, storm surge, flooding, heat waves, public health. • Global climate change affects megacities' climate, environment and comfort. • Growing urbanization requires integrated weather, environment and climate monitoring systems. • New generation of multi-scale models and seamless integrated urban services are needed. Reference Baklanov, A., L.T. Molina, M. Gauss (2016) Megacities, air quality and climate. Atmospheric Environment, 126: 235-249. doi:10.1016/j.atmosenv.2015.11.059

  10. Rejection of seamless pipe noise in magnetic flux leakage data obtained from gas pipeline inspection

    NASA Astrophysics Data System (ADS)

    Afzal, Muhammad; Udpa, Satish; Udpa, Lalita; Lord, William

    2000-05-01

    Natural gas is traditionally transmitted from production facilities to customer locations through a vast pipeline network. A major segment of this network employs seamless pipes. This is especially true for smaller diameter transmission and distribution lines. Manufacturing process associated with the production of seamless pipes contribute to a helical variation in the pipe along the axis. The deformation introduces an artifact in the data obtained from MFL inspection of these pipelines. This seamless pipe noise is usually correlated with signals generated by defects and other elements (joints, tees, etc.) in pipelines, and can therefore, mask their indications in MFL data. This warrants the need for methods to improve signal-to-noise ratio (SNR) in MFL data from seamless pipes. This paper presents a technique for detecting signals in MFL data from seamless pipes. The approach processes the data in various steps. First, a wavelet based denoising technique is applied to reduce the noise due to instrumentation and other sources. An adaptive filtering approach is then applied to reject seamless noise in the data. Since the inspection of pipelines typically generates vast amounts of data, it is imperative that the algorithm be computationally efficient. The processing method has to be robust in that it should be data independent. The approach described in this paper meet these criteria. Results from application of the approach to data from field tests are presented.