WorldWideScience

Sample records for vibrationless rotary coupling

  1. Design of an Improved Type Rotary Inductive Coupling Structure for Rotatable Contactless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Lee Jia-You

    2015-01-01

    Full Text Available This paper is aimed at analyzing the rotary inductive coupling structure of contactless rotary transformer. The main feature of the proposed rotatable contactless power transfer system is which winding is coaxial-interlayered for improving the magnetic coupling capability. There is no ferrite core used in the secondary-side of the rotary inductive coupling structure, this helps to ease the exerted force that is stress by the secondary-side on spindle. In order to verify the feasibility of the proposed contactless power transfer system for rotary applications, an inductive powered rotary machinery and the control system have been integrated. The experimental results show that the maximum power transfer efficiency of the proposed rotary inductive coupling structure is about 94.8%. The maximum output power received in the load end is 1030 W with transmission efficiency of 88%.

  2. Thermal Behaviors and Lubrication Properties in Rotary Blade Coupling of Sports Utility Vehicles

    Science.gov (United States)

    Huang, Kuohsiu David; Tzeng, Sheng-Chung; Ma, Wei-Ping; Wu, Tai-Sheng

    This study attempts to improve the local high temperature distributions in rotary-blade-coupling (RBC), which is the source of motive power for sport-utility-vehicles (SUV). The experiment takes RBC with forced convection and circumferential ribs for the research on heat transfer enhancement. During rotation, RBC produces centrifugal fluid flow, convection phenomenon and temperature distributions that differ with rotational speed. Simultaneously, rotation enhances the turbulence intensity of the flow field, promoting heat transfer and destabilizing Taylor vortices. This instability influences the local heat transfer distribution and damages the machine parts because of overheating. To analyze the actual convection of the rotary flow field, the experiment testing section is designed based on the actual size of the RBC. In the experiment, the RBC is cooled via forced exterior oil supply, and ring-shaped turbulence ribs of three aspect ratios (AR=5/3, 2.5, and 10/3) are added to augment the heat transfer area, for discussing the axial temperature distributions at the top and bottom of the RBC. The experiment adopts major physical parameters within 2.856 × 105 ≤Ta≤2.031 × 106 and 0.053 ≤Re ≤1.054 to discuss the heat transfer effect in the interior rotary flow distribution groove of RBC in the four-wheel-drive (4WD) vehicle. Finally, based on the relevant experimental results, an empirical correlation is established for the reference of 4WD vehicle designers.

  3. Fluidized bed coupled rotary reactor for nanoparticles coating via atomic layer deposition.

    Science.gov (United States)

    Duan, Chen-Long; Liu, Xiao; Shan, Bin; Chen, Rong

    2015-07-01

    A fluidized bed coupled rotary reactor has been designed for coating on nanoparticles (NPs) via atomic layer deposition. It consists of five major parts: reaction chamber, dosing and fluidizing section, pumping section, rotary manipulator components, as well as a double-layer cartridge for the storage of particles. In the deposition procedure, continuous fluidization of particles enlarges and homogenizes the void fraction in the particle bed, while rotation enhances the gas-solid interactions to stabilize fluidization. The particle cartridge presented here enables both the fluidization and rotation acting on the particle bed, demonstrated by the analysis of pressure drop. Moreover, enlarged interstitials and intense gas-solid contact under sufficient fluidizing velocity and proper rotation speed facilitate the precursor delivery throughout the particle bed and consequently provide a fast coating process. The cartridge can ensure precursors flowing through the particle bed exclusively to achieve high utilization without static exposure operation. By optimizing superficial gas velocities and rotation speeds, minimum pulse time for complete coating has been shortened in experiment, and in situ mass spectrometry showed the precursor usage can reach 90%. Inductively coupled plasma-optical emission spectroscopy results suggested a saturated growth of nanoscale Al2O3 films on spherical SiO2 NPs. Finally, the uniformity and composition of the shells were characterized by high angle annular dark field-transmission electron microscopy and energy dispersive X-ray spectroscopy.

  4. Fluidized bed coupled rotary reactor for nanoparticles coating via atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Chen-Long; Liu, Xiao; Chen, Rong, E-mail: rongchen@mail.hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China); Shan, Bin, E-mail: rongchen@mail.hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China)

    2015-07-15

    A fluidized bed coupled rotary reactor has been designed for coating on nanoparticles (NPs) via atomic layer deposition. It consists of five major parts: reaction chamber, dosing and fluidizing section, pumping section, rotary manipulator components, as well as a double-layer cartridge for the storage of particles. In the deposition procedure, continuous fluidization of particles enlarges and homogenizes the void fraction in the particle bed, while rotation enhances the gas-solid interactions to stabilize fluidization. The particle cartridge presented here enables both the fluidization and rotation acting on the particle bed, demonstrated by the analysis of pressure drop. Moreover, enlarged interstitials and intense gas–solid contact under sufficient fluidizing velocity and proper rotation speed facilitate the precursor delivery throughout the particle bed and consequently provide a fast coating process. The cartridge can ensure precursors flowing through the particle bed exclusively to achieve high utilization without static exposure operation. By optimizing superficial gas velocities and rotation speeds, minimum pulse time for complete coating has been shortened in experiment, and in situ mass spectrometry showed the precursor usage can reach 90%. Inductively coupled plasma-optical emission spectroscopy results suggested a saturated growth of nanoscale Al{sub 2}O{sub 3} films on spherical SiO{sub 2} NPs. Finally, the uniformity and composition of the shells were characterized by high angle annular dark field-transmission electron microscopy and energy dispersive X-ray spectroscopy.

  5. Developments and Validations of Fully Coupled CFD and Practical Vortex Transport Method for High-Fidelity Wake Modeling in Fixed and Rotary Wing Applications

    Science.gov (United States)

    Anusonti-Inthra, Phuriwat

    2010-01-01

    A novel Computational Fluid Dynamics (CFD) coupling framework using a conventional Reynolds-Averaged Navier-Stokes (BANS) solver to resolve the near-body flow field and a Particle-based Vorticity Transport Method (PVTM) to predict the evolution of the far field wake is developed, refined, and evaluated for fixed and rotary wing cases. For the rotary wing case, the RANS/PVTM modules are loosely coupled to a Computational Structural Dynamics (CSD) module that provides blade motion and vehicle trim information. The PVTM module is refined by the addition of vortex diffusion, stretching, and reorientation models as well as an efficient memory model. Results from the coupled framework are compared with several experimental data sets (a fixed-wing wind tunnel test and a rotary-wing hover test).

  6. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio.

    Science.gov (United States)

    Anandakrishnan, Ramu; Zuckerman, Daniel M

    2017-01-01

    ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access and other possible mechanisms suggest that, when the ratio of protons transported per ATP hydrolyzed exceeds one, the one-at-a-time proton transport by the rotary mechanism is faster than other possible mechanisms across a wide range of driving conditions. When the ratio is one, there is no intrinsic difference in the free energy landscape between mechanisms, and therefore all mechanisms can exhibit the same kinetic performance. To our knowledge all known rotary pumps have an H+:ATP ratio greater than one, and all known alternating access ATP-driven proton pumps have a ratio of one. Our analysis suggests a possible explanation for this apparent relationship between coupling ratio and mechanism. When the conditions under which the pump must operate permit a coupling ratio greater than one, the rotary mechanism may have been selected for its kinetic advantage. On the other hand, when conditions require a coupling ratio of one or less, the alternating access mechanism may have been selected for other possible advantages resulting from its structural and functional simplicity.

  7. Design of a new separable rotary transformer

    Science.gov (United States)

    Gong, X. F.; Zhang, L.; Feng, E. J.

    2017-09-01

    A new-type separable rotary transformer which can be used in rotary steerable drilling is designed to deliver power efficiently from a stationary primary source to a rotary secondary load over a relatively large air gap via magnetic coupling. In this paper, E-type magnetic cores are reasonably distributed so that rotation of the rotary secondary has the least influence on reluctance of magnetic coupling. The influence of different winding layouts and connection modes on self-inductance and coupling coefficient is studied. By analysing the influence of the different geometrical shapes of cores on magnetic path, a design principle is proposed.

  8. Rotary Transformer

    Science.gov (United States)

    McLyman, Colonel Wm. T.

    1996-01-01

    None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.

  9. Rotary capacitor

    CERN Multimedia

    1971-01-01

    The rotating wheel of the rotary capacitor representing the most critical part of the new radio-frequency system of the synchro-cyclotron. The three rows of teeth on the circumference of the wheel pass between four rows of stator blades with a minimum clearance of 1 mm at a velocity of 1700 rev/min.

  10. Rotary ATPases

    Science.gov (United States)

    Stewart, Alastair G.; Sobti, Meghna; Harvey, Richard P.; Stock, Daniela

    2013-01-01

    Rotary ATPases are molecular rotary motors involved in biological energy conversion. They either synthesize or hydrolyze the universal biological energy carrier adenosine triphosphate. Recent work has elucidated the general architecture and subunit compositions of all three sub-types of rotary ATPases. Composite models of the intact F-, V- and A-type ATPases have been constructed by fitting high-resolution X-ray structures of individual subunits or sub-complexes into low-resolution electron densities of the intact enzymes derived from electron cryo-microscopy. Electron cryo-tomography has provided new insights into the supra-molecular arrangement of eukaryotic ATP synthases within mitochondria and mass-spectrometry has started to identify specifically bound lipids presumed to be essential for function. Taken together these molecular snapshots show that nano-scale rotary engines have much in common with basic design principles of man made machines from the function of individual “machine elements” to the requirement of the right “fuel” and “oil” for different types of motors. PMID:23369889

  11. ROTARY SWITCH

    Science.gov (United States)

    Watterberg, J.P.E.

    1960-03-15

    BS>A compact rotary-type switoh was designed wherein an insulating shell carries circumferentially spaced contacts exposed to its interior and also carries, on a re-entrant portion, resilient contact arms having contact portions aligned wth and biased toward the spaced contacts. A dielectric rotor with a movable wall between the contacts and contact arms has an aperture that may be turned into or out of registry with the contacts so as to establish or interrupt circuits.

  12. Rotary Release Mechanism With Fusible Link

    Science.gov (United States)

    Sevilla, Donald R.; Blomquist, Richard S.

    1996-01-01

    Rotary release mechanism includes fusible rotary link made of alloy that melts at relatively low temperature of 60 degrees C. When solid, link couples driving shaft to driven shaft. When necessary, link melted to temporarily decouple two shafts. Upon cooling below melting temperature link hardens, so it once again couples two shafts. Release mechanism extremely compact alternative to pyrotechnic release device. Basic concept applied to such other mechanisms as pin pullers, pin pushers, electrical-disconnection mechanisms, and clutches.

  13. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio

    OpenAIRE

    Anandakrishnan, Ramu; Zuckerman, Daniel M.

    2017-01-01

    ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access an...

  14. Generation of rotary vibrations in internal combustion engines with elastically coupled electric power systems; Erzeugung von verbrennungsmotorischen Drehschwingungen mit elastisch gekoppelten elektrischen Antrieben

    Energy Technology Data Exchange (ETDEWEB)

    Falkenstein, Jens Werner [Rostock Univ. (Germany). Inst. fuer Antriebstechnik und Mechatronik

    2004-07-01

    The design of motor car powertrains requires simulations as well as prototype tests. For the simulations, prototype parameters must be identified on test rigs, simulation results must be verified, and life tests must be carried out. This necessitates realistic and reproducible excitation of vibrations. Thee book describes the development and construction of a test rig which, with the aid of electric power systems, induces rotary vibrations like those which may occur in internal combustion engines due to gas forces and unbalanced mass forces. In combination with excess resonance, the test stand achieves high dynamics with average rotary momenta up to 600 Nm. The development process is documented, from test stand design with specially developed servo-engines to the control hardware to modelling, control element design, and commissioning. (orig.)

  15. Rotary filtration system

    Science.gov (United States)

    Herman, David T [Aiken, SC; Maxwell, David N [Aiken, SC

    2011-04-19

    A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

  16. Methods and apparatus for controlling rotary machines

    Science.gov (United States)

    Bagepalli, Bharat Sampathkumaran [Niskayuna, NY; Jansen, Patrick Lee [Scotia, NY; Barnes, Gary R [Delanson, NY; Fric, Thomas Frank [Greer, SC; Lyons, James Patrick Francis [Niskayuna, NY; Pierce, Kirk Gee [Simpsonville, SC; Holley, William Edwin [Greer, SC; Barbu, Corneliu [Guilderland, NY

    2009-09-01

    A control system for a rotary machine is provided. The rotary machine has at least one rotating member and at least one substantially stationary member positioned such that a clearance gap is defined between a portion of the rotating member and a portion of the substantially stationary member. The control system includes at least one clearance gap dimension measurement apparatus and at least one clearance gap adjustment assembly. The adjustment assembly is coupled in electronic data communication with the measurement apparatus. The control system is configured to process a clearance gap dimension signal and modulate the clearance gap dimension.

  17. Ultrasonic rotary-hammer drill

    Science.gov (United States)

    Bar-Cohen, Yoseph (Inventor); Badescu, Mircea (Inventor); Sherrit, Stewart (Inventor); Bao, Xiaoqi (Inventor); Kassab, Steve (Inventor)

    2010-01-01

    A mechanism for drilling or coring by a combination of sonic hammering and rotation. The drill includes a hammering section with a set of preload weights mounted atop a hammering actuator and an axial passage through the hammering section. In addition, a rotary section includes a motor coupled to a drive shaft that traverses the axial passage through the hammering section. A drill bit is coupled to the drive shaft for drilling by a combination of sonic hammering and rotation. The drill bit includes a fluted shaft leading to a distal crown cutter with teeth. The bit penetrates sampled media by repeated hammering action. In addition, the bit is rotated. As it rotates the fluted bit carries powdered cuttings helically upward along the side of the bit to the surface.

  18. Rotary Series Elastic Actuator

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Mehling, Joshua S. (Inventor); Parsons, Adam H. (Inventor); Griffith, Bryan Kristian (Inventor); Radford, Nicolaus A. (Inventor); Permenter, Frank Noble (Inventor); Davis, Donald R. (Inventor); Ambrose, Robert O. (Inventor); Junkin, Lucien Q. (Inventor)

    2013-01-01

    A rotary actuator assembly is provided for actuation of an upper arm assembly for a dexterous humanoid robot. The upper arm assembly for the humanoid robot includes a plurality of arm support frames each defining an axis. A plurality of rotary actuator assemblies are each mounted to one of the plurality of arm support frames about the respective axes. Each rotary actuator assembly includes a motor mounted about the respective axis, a gear drive rotatably connected to the motor, and a torsion spring. The torsion spring has a spring input that is rotatably connected to an output of the gear drive and a spring output that is connected to an output for the joint.

  19. Rotary mechanical latch

    Science.gov (United States)

    Spletzer, Barry L.; Martinez, Michael A.; Marron, Lisa C.

    2012-11-13

    A rotary mechanical latch for positive latching and unlatching of a rotary device with a latchable rotating assembly having a latching gear that can be driven to latched and unlatched states by a drive mechanism such as an electric motor. A cam arm affixed to the latching gear interfaces with leading and trailing latch cams affixed to a flange within the drive mechanism. The interaction of the cam arm with leading and trailing latch cams prevents rotation of the rotating assembly by external forces such as those due to vibration or tampering.

  20. Rotary drum separator system

    Science.gov (United States)

    Barone, Michael R. (Inventor); Murdoch, Karen (Inventor); Scull, Timothy D. (Inventor); Fort, James H. (Inventor)

    2009-01-01

    A rotary phase separator system generally includes a step-shaped rotary drum separator (RDS) and a motor assembly. The aspect ratio of the stepped drum minimizes power for both the accumulating and pumping functions. The accumulator section of the RDS has a relatively small diameter to minimize power losses within an axial length to define significant volume for accumulation. The pumping section of the RDS has a larger diameter to increase pumping head but has a shorter axial length to minimize power losses. The motor assembly drives the RDS at a low speed for separating and accumulating and a higher speed for pumping.

  1. Rotary jagas stipendiume

    Index Scriptorium Estoniae

    2009-01-01

    Pärnu Rotary klubi aastapäevapeol 11. mail Ammende villas anti stipendium viiele Pärnumaa noorele, teiste seas pälvis preemia Pärnu Ülejõe Gümnaasiumi muusikaõpetaja Fred Rõigas ja Pärnu Muusikakoolis trompetit õppiv Chris Sommer

  2. Rotary magnetic heat pump

    Science.gov (United States)

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  3. Rotary shaft sealing assembly

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  4. Rotary-wing aeroservoelastic problems

    Science.gov (United States)

    Friedmann, Peretz P.

    1992-01-01

    The state-of-the-art in the field of alleviating rotary-wing aeroservoelastic problems (by using active controls that modify the pitch of a helicopter rotor blade so as to alleviate dynamic effects) is assessed, and the more promising developments are identified. Special attention is given to the active control of aeromechanical and aeroelastic problems, such as the active control of ground resonance, active control of air resonance, and active control of blade aeroelastic instabilities; individual blade control; active control of vibration reduction using a conventional swashplate; and coupled rotor/fuselage vibration reduction using open-loop active control. Some results are presented for each of these topics, illustrating the efficiency of the techniques which have been developed.

  5. Micro rotary machine and methods for using same

    Science.gov (United States)

    Stalford, Harold L [Norman, OK

    2012-04-17

    A micro rotary machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft comprises a horizontal shaft and is operable to be rotated by the micro actuator. A micro tool is coupled to the micro shaft and is operable to perform work in response to motion of the micro shaft.

  6. Piezoelectric Rotary Tube Motor

    Science.gov (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  7. Rotary deformity in degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    1994-05-15

    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected.

  8. BIOMATERIALS FOR ROTARY BLOOD PUMPS

    NARCIS (Netherlands)

    VANOEVEREN, W

    Rotary blood pumps are used for cardiac assist and cardiopulmonary support since mechanical blood damage is less than with conventional roller pumps. The high shear rate in the rotary pump and the reduced anticoagulation of the patient during prolonged pumping enforces high demands on the

  9. The dynamic stator stalk of rotary ATPases

    Science.gov (United States)

    Stewart, Alastair G.; Lee, Lawrence K.; Donohoe, Mhairi; Chaston, Jessica J.; Stock, Daniela

    2012-01-01

    Rotary ATPases couple ATP hydrolysis/synthesis with proton translocation across biological membranes and so are central components of the biological energy conversion machinery. Their peripheral stalks are essential components that counteract torque generated by rotation of the central stalk during ATP synthesis or hydrolysis. Here we present a 2.25-Å resolution crystal structure of the peripheral stalk from Thermus thermophilus A-type ATPase/synthase. We identify bending and twisting motions inherent within the structure that accommodate and complement a radial wobbling of the ATPase headgroup as it progresses through its catalytic cycles, while still retaining azimuthal stiffness necessary to counteract rotation of the central stalk. The conformational freedom of the peripheral stalk is dictated by its unusual right-handed coiled-coil architecture, which is in principle conserved across all rotary ATPases. In context of the intact enzyme, the dynamics of the peripheral stalks provides a potential mechanism for cooperativity between distant parts of rotary ATPases. PMID:22353718

  10. Rotary shaft seal

    Science.gov (United States)

    Langebrake, C.O.

    1984-01-01

    The invention is a novel rotary shaft seal assembly which provides positive-contact sealing when the shaft is not rotated and which operates with its sealing surfaces separated by a film of compressed ambient gas whose width is independent of the speed of shaft rotation. In a preferred embodiment, the assembly includes a disc affixed to the shaft for rotation therewith. Axially movable, non-rotatable plates respectively supported by sealing bellows are positioned on either side of the disc to be in sealing engagement therewith. Each plate carries piezoelectric transucer elements which are electrically energized at startup to produce films of compressed ambient gas between the confronting surfaces of the plates and the disc. Following shutdown of the shaft, the transducer elements are de-energized. A control circuit responds to incipient rubbing between the plate and either disc by altering the electrical input to the transducer elements to eliminate rubbing.

  11. Development of a Piezoelectric Rotary Hammer Drill

    Science.gov (United States)

    Domm, Lukas N.

    2011-01-01

    The Piezoelectric Rotary Hammer Drill is designed to core through rock using a combination of rotation and high frequency hammering powered by a single piezoelectric actuator. It is designed as a low axial preload, low mass, and low power device for sample acquisition on future missions to extraterrestrial bodies. The purpose of this internship is to develop and test a prototype of the Piezoelectric Rotary Hammer Drill in order to verify the use of a horn with helical or angled cuts as a hammering and torque inducing mechanism. Through an iterative design process using models in ANSYS Finite Element software and a Mason's Equivalent Circuit model in MATLAB, a horn design was chosen for fabrication based on the predicted horn tip motion, electromechanical coupling, and neutral plane location. The design was then machined and a test bed assembled. The completed prototype has proven that a single piezoelectric actuator can be used to produce both rotation and hammering in a drill string through the use of a torque inducing horn. Final data results include bit rotation produced versus input power, and best drilling rate achieved with the prototype.

  12. 21 CFR 872.4840 - Rotary scaler.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rotary scaler. 872.4840 Section 872.4840 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4840 Rotary scaler. (a) Identification. A rotary scaler is an...

  13. Rotary condenser for SC2

    CERN Multimedia

    1975-01-01

    During 1975 the SC2 performance was improved among other things by redesigning some of the elements of the ROTCO (Annual Report 1975, p. 55). The photo shows an interior wiew of the housing of the rotary condenser and of the sixteen sets of shaped stator blades.

  14. Rotary reactor and use thereof

    NARCIS (Netherlands)

    Bakker Wridzer, J.W.; Kapteijn, F.; Moulijn, J.A.

    1998-01-01

    The invention relates to a rotary reactor consisting of a number of tubular reaction compartments (A), each provided with a first end and a second end, a ceramic first reactor end plate (B) in which said first ends are received, and a second end plate (B) in which said second ends are received,

  15. Cryo EM structure of intact rotary H+-ATPase/synthase from Thermus thermophilus.

    Science.gov (United States)

    Nakanishi, Atsuko; Kishikawa, Jun-Ichi; Tamakoshi, Masatada; Mitsuoka, Kaoru; Yokoyama, Ken

    2018-01-08

    Proton translocating rotary ATPases couple ATP hydrolysis/synthesis, which occurs in the soluble domain, with proton flow through the membrane domain via a rotation of the common central rotor complex against the surrounding peripheral stator apparatus. Here, we present a large data set of single particle cryo-electron micrograph images of the V/A type H+-rotary ATPase from the bacterium Thermus thermophilus, enabling the identification of three rotational states based on the orientation of the rotor subunit. Using masked refinement and classification with signal subtractions, we obtain homogeneous reconstructions for the whole complexes and soluble V1 domains. These reconstructions are of higher resolution than any EM map of intact rotary ATPase reported previously, providing a detailed molecular basis for how the rotary ATPase maintains structural integrity of the peripheral stator apparatus, and confirming the existence of a clear proton translocation path from both sides of the membrane.

  16. An Improved Rotary Interpolation Based on FPGA

    Directory of Open Access Journals (Sweden)

    Mingyu Gao

    2014-08-01

    Full Text Available This paper presents an improved rotary interpolation algorithm, which consists of a standard curve interpolation module and a rotary process module. Compared to the conventional rotary interpolation algorithms, the proposed rotary interpolation algorithm is simpler and more efficient. The proposed algorithm was realized on a FPGA with Verilog HDL language, and simulated by the ModelSim software, and finally verified on a two-axis CNC lathe, which uses rotary ellipse and rotary parabolic as an example. According to the theoretical analysis and practical process validation, the algorithm has the following advantages: firstly, less arithmetic items is conducive for interpolation operation; and secondly the computing time is only two clock cycles of the FPGA. Simulations and actual tests have proved that the high accuracy and efficiency of the algorithm, which shows that it is highly suited for real-time applications.

  17. The rotary subwoofer: a controllable infrasound source.

    Science.gov (United States)

    Park, Joseph; Garcés, Milton; Thigpen, Bruce

    2009-04-01

    The rotary subwoofer is a novel acoustic transducer capable of projecting infrasonic signals at high sound pressure levels. The projector produces higher acoustic particle velocities than conventional transducers which translate into higher radiated sound pressure levels. This paper characterizes measured performance of a rotary subwoofer and presents a model to predict sound pressure levels.

  18. Unidirectional rotary motion in achiral molecular motors

    NARCIS (Netherlands)

    Kistemaker, Jos C. M.; Stacko, Peter; Visser, Johan; Feringa, Ben L.

    2015-01-01

    Control of the direction of motion is an essential feature of biological rotary motors and results from the intrinsic chirality of the amino acids from which the motors are made. In synthetic autonomous light-driven rotary motors, point chirality is transferred to helical chirality, and this governs

  19. Rotary-atomizer electric power generator

    NARCIS (Netherlands)

    Nguyen, Trieu; Tran, Tuan; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.

    2015-01-01

    We report experimental and theoretical results on a ballistic energy-conversion method based on a rotary atomizer working with a droplet acceleration-deceleration cycle. In a rotary atomizer, liquid is fed onto the center of a rotating flat surface, where it spreads out under the action of the

  20. DEMES rotary joint: theories and applications

    Science.gov (United States)

    Wang, Shu; Hao, Zhaogang; Li, Mingyu; Huang, Bo; Sun, Lining; Zhao, Jianwen

    2017-04-01

    As a kind of dielectric elastomer actuators, dielectric elastomer minimum energy structure (DEMES) can realize large angular deformations by small voltage-induced strains, which make them an attractive candidate for use as biomimetic robotics. Considering the rotary joint is a basic and common component of many biomimetic robots, we have been fabricated rotary joint by DEMES and developed its performances in the past two years. In this paper, we have discussed the static analysis, dynamics analysis and some characteristics of the DEMES rotary joint. Based on theoretical analysis, some different applications of the DEMES rotary joint were presented, such as a flapping wing, a biomimetic fish and a two-legged walker. All of the robots are fabricated by DEMES rotary joint and can realize some basic biomimetic motions. Comparing with traditional rigid robot, the robot based on DEMES is soft and light, so it has advantage on the collision-resistant.

  1. Rotation of artificial rotor axles in rotary molecular motors.

    Science.gov (United States)

    Baba, Mihori; Iwamoto, Kousuke; Iino, Ryota; Ueno, Hiroshi; Hara, Mayu; Nakanishi, Atsuko; Kishikawa, Jun-Ichi; Noji, Hiroyuki; Yokoyama, Ken

    2016-10-04

    F 1 - and V 1 -ATPase are rotary molecular motors that convert chemical energy released upon ATP hydrolysis into torque to rotate a central rotor axle against the surrounding catalytic stator cylinder with high efficiency. How conformational change occurring in the stator is coupled to the rotary motion of the axle is the key unknown in the mechanism of rotary motors. Here, we generated chimeric motor proteins by inserting an exogenous rod protein, FliJ, into the stator ring of F 1 or of V 1 and tested the rotation properties of these chimeric motors. Both motors showed unidirectional and continuous rotation, despite no obvious homology in amino acid sequence between FliJ and the intrinsic rotor subunit of F 1 or V 1 These results showed that any residue-specific interactions between the stator and rotor are not a prerequisite for unidirectional rotation of both F 1 and V 1 The torque of chimeric motors estimated from viscous friction of the rotation probe against medium revealed that whereas the F 1 -FliJ chimera generates only 10% of WT F 1 , the V 1 -FliJ chimera generates torque comparable to that of V 1 with the native axle protein that is structurally more similar to FliJ than the native rotor of F 1 This suggests that the gross structural mismatch hinders smooth rotation of FliJ accompanied with the stator ring of F 1 .

  2. Robustness of the rotary catalysis mechanism of F1-ATPase.

    Science.gov (United States)

    Watanabe, Rikiya; Matsukage, Yuki; Yukawa, Ayako; Tabata, Kazuhito V; Noji, Hiroyuki

    2014-07-11

    F1-ATPase (F1) is the rotary motor protein fueled by ATP hydrolysis. Previous studies have suggested that three charged residues are indispensable for catalysis of F1 as follows: the P-loop lysine in the phosphate-binding loop, GXXXXGK(T/S); a glutamic acid that activates water molecules for nucleophilic attack on the γ-phosphate of ATP (general base); and an arginine directly contacting the γ-phosphate (arginine finger). These residues are well conserved among P-loop NTPases. In this study, we investigated the role of these charged residues in catalysis and torque generation by analyzing alanine-substituted mutants in the single-molecule rotation assay. Surprisingly, all mutants continuously drove rotary motion, even though the rotational velocity was at least 100,000 times slower than that of wild type. Thus, although these charged residues contribute to highly efficient catalysis, they are not indispensable to chemo-mechanical energy coupling, and the rotary catalysis mechanism of F1 is far more robust than previously thought. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Robustness of the Rotary Catalysis Mechanism of F1-ATPase*

    Science.gov (United States)

    Watanabe, Rikiya; Matsukage, Yuki; Yukawa, Ayako; Tabata, Kazuhito V.; Noji, Hiroyuki

    2014-01-01

    F1-ATPase (F1) is the rotary motor protein fueled by ATP hydrolysis. Previous studies have suggested that three charged residues are indispensable for catalysis of F1 as follows: the P-loop lysine in the phosphate-binding loop, GXXXXGK(T/S); a glutamic acid that activates water molecules for nucleophilic attack on the γ-phosphate of ATP (general base); and an arginine directly contacting the γ-phosphate (arginine finger). These residues are well conserved among P-loop NTPases. In this study, we investigated the role of these charged residues in catalysis and torque generation by analyzing alanine-substituted mutants in the single-molecule rotation assay. Surprisingly, all mutants continuously drove rotary motion, even though the rotational velocity was at least 100,000 times slower than that of wild type. Thus, although these charged residues contribute to highly efficient catalysis, they are not indispensable to chemo-mechanical energy coupling, and the rotary catalysis mechanism of F1 is far more robust than previously thought. PMID:24876384

  4. A dual resonant rectilinear-to-rotary oscillation converter for low frequency broadband electromagnetic energy harvesting

    Science.gov (United States)

    Deng, Wei; Wang, Ya

    2017-09-01

    This paper reports a dual resonant rectilinear-to-rotary oscillation converter (RROC) for low frequency broadband electromagnetic energy harvesting from ambient vibrations. An approximate theoretical model has been established to integrate the electromechanical coupling into a comprehensive electromagnetic-dynamic model of the dual resonant RROC. Numerical simulation has proved the nature of dual resonances by revealing that both the rectilinear resonance and the rotary resonance could be achieved when the stand-alone rectilinear oscillator (RLO) and the stand-alone rotary oscillator (RTO) were excited independently. Simulation on the magnetically coupled RROC has also shown that the rectilinear resonance and the rotary resonance could be obtained simultaneously in the low-frequency region (2-14 Hz) with well-defined restoring torque (M r ) and the initial rotation angle of the RLO (ψ). The magnetic interaction patterns between the rectilinear and the RTOs have been categorized based on aforementioned simulation results. Both simulation and experimental results have demonstrated broadband output attributing from the dual resonances. Experimental results have also indicated that the RROC could have wide bandwidth in a much lower frequency region (2-8 Hz) even without the rotary resonance as long as the system parameters are carefully tuned. Parameter analysis on different values of M r and ψ are experimentally carried out to provide a quantitative guidance of designing the RROC to achieve an optimal power density.

  5. System and method for cooling a superconducting rotary machine

    Science.gov (United States)

    Ackermann, Robert Adolf [Schenectady, NY; Laskaris, Evangelos Trifon [Schenectady, NY; Huang, Xianrui [Clifton Park, NY; Bray, James William [Niskayuna, NY

    2011-08-09

    A system for cooling a superconducting rotary machine includes a plurality of sealed siphon tubes disposed in balanced locations around a rotor adjacent to a superconducting coil. Each of the sealed siphon tubes includes a tubular body and a heat transfer medium disposed in the tubular body that undergoes a phase change during operation of the machine to extract heat from the superconducting coil. A siphon heat exchanger is thermally coupled to the siphon tubes for extracting heat from the siphon tubes during operation of the machine.

  6. Rotary Valve FY 2016 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Fitsos, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-07

    The fiscal year started with the Rotary Valve (RV) being reassembled after having crashed in June of 2015. The crash occurred when the RV inner surface contacted the housing. The cause of the crash was never confirmed. No particles were found in the 2.5 thousandths of an inch gap and the filters the helium gas passed through were all clean. There were marks on the bearings that looked like electrostatic discharge as shown below in Figure 1. These marks hadn’t been seen before and there were similar discharge marks on some of the ball bearings. Examples of this were found in a literature search of bearing failures. This leads to a possible cause due to this arcing affecting the rotational accuracy of the bearings driving the RV into the housing.

  7. Aerodynamic seals for rotary machine

    Science.gov (United States)

    Bidkar, Rahul Anil; Cirri, Massimiliano; Thatte, Azam Mihir; Williams, John Robert

    2016-02-09

    An aerodynamic seal assembly for a rotary machine includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having multiple labyrinth teeth therebetween facing the rotor. The sealing device segment also includes multiple flexures connected to the shoe plate and to a top interface element, wherein the multiple flexures are configured to allow the high pressure fluid to occupy a forward cavity and the low pressure fluid to occupy an aft cavity. Further, the sealing device segments include a secondary seal attached to the top interface element at one first end and positioned about the flexures and the shoe plate at one second end.

  8. Conceptual Study of Rotary-Wing Microrobotics

    National Research Council Canada - National Science Library

    Chabak, Kelson D

    2008-01-01

    This thesis presents a novel rotary-wing micro-electro-mechanical systems (MEMS) robot design. Two MEMS wing designs were designed, fabricated and tested including one that possesses features conducive to insect level aerodynamics...

  9. Unidirectional rotary motion in achiral molecular motors.

    Science.gov (United States)

    Kistemaker, Jos C M; Štacko, Peter; Visser, Johan; Feringa, Ben L

    2015-11-01

    Control of the direction of motion is an essential feature of biological rotary motors and results from the intrinsic chirality of the amino acids from which the motors are made. In synthetic autonomous light-driven rotary motors, point chirality is transferred to helical chirality, and this governs their unidirectional rotation. However, achieving directional rotary motion in an achiral molecular system in an autonomous fashion remains a fundamental challenge. Here, we report an achiral molecular motor in which the presence of a pseudo-asymmetric carbon atom proved to be sufficient for exclusive autonomous disrotary motion of two appended rotor moieties. Isomerization around the two double bonds enables both rotors to move in the same direction with respect to their surroundings--like wheels on an axle--demonstrating that autonomous unidirectional rotary motion can be achieved in a symmetric system.

  10. Rotary adsorbers for continuous bulk separations

    Science.gov (United States)

    Baker, Frederick S [Oak Ridge, TN

    2011-11-08

    A rotary adsorber for continuous bulk separations is disclosed. The rotary adsorber includes an adsorption zone in fluid communication with an influent adsorption fluid stream, and a desorption zone in fluid communication with a desorption fluid stream. The fluid streams may be gas streams or liquid streams. The rotary adsorber includes one or more adsorption blocks including adsorbent structure(s). The adsorbent structure adsorbs the target species that is to be separated from the influent fluid stream. The apparatus includes a rotary wheel for moving each adsorption block through the adsorption zone and the desorption zone. A desorption circuit passes an electrical current through the adsorbent structure in the desorption zone to desorb the species from the adsorbent structure. The adsorbent structure may include porous activated carbon fibers aligned with their longitudinal axis essentially parallel to the flow direction of the desorption fluid stream. The adsorbent structure may be an inherently electrically-conductive honeycomb structure.

  11. Rotary endodontics in primary teeth - A review.

    Science.gov (United States)

    George, Sageena; Anandaraj, S; Issac, Jyoti S; John, Sheen A; Harris, Anoop

    2016-01-01

    Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the "gold-standard" over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel-titanium (Ni-Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel-titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed.

  12. Broadband rotary joint for high-speed ultrahigh-resolution endoscopic OCT imaging at 800  nm.

    Science.gov (United States)

    Park, Hyeon-Cheol; Mavadia-Shukla, Jessica; Yuan, Wu; Alemohammad, Milad; Li, Xingde

    2017-12-01

    We report the development of a broadband rotary joint for high-speed ultrahigh-resolution endoscopic optical coherence tomography (OCT) imaging in the 800 nm spectral range. This rotary joint features a pair of achromatic doublets in order to achieve broadband operation for a 3 dB bandwidth over 150 nm. The measured one-way throughput of the rotary joint is greater than 80%, while the fluctuation of the double-pass coupling efficiency during 360 deg rotation is less than ±5% at a near video-rate speed of 20 revolutions/s (rps). The rotary joint is used in conjunction with a diffractive-optics-based endoscope and 800 nm spectral domain OCT system and achieved an ultrahigh axial resolution of ∼2.4  μm in air. The imaging performance is demonstrated by 3D circumferential imaging of a mouse colon in vivo.

  13. High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, Richard Clement [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2005-09-01

    This thesis describes the development of two high bandwidth short-stroke rotary fast tool servos and the hybrid rotary/linear electromagnetic actuator developed for one of them. Design insights, trade-o® methodologies, and analytical tools are developed for precision mechanical systems, power and signal electronic systems, control systems, normal-stress electromagnetic actuators, and the dynamics of the combined systems.

  14. Man-Made Rotary Nanomotors: A Review of Recent Development

    Science.gov (United States)

    Kim, Kwanoh; Guo, Jianhe; Liang, Z. X.; Zhu, F. Q.; Fan, D. L.

    2016-01-01

    The development rotary nanomotors is an essential step towards intelligent nanomachines and nanorobots. In this article, we review the concept, design, working mechanisms, and applications of the state-of-the-art rotary nanomotors made from synthetic nanoentities. The rotary nanomotors are categorized according to the energy sources employed to drive the rotary motion, including biochemical, optical, magnetic, and electric fields. The unique advantages and limitations for each type of rotary nanomachines are discussed. The advances of rotary nanomotors is pivotal for realizing dream nanomachines for myriad applications including microfluidics, biodiagnosis, nano-surgery, and biosubstance delivery. PMID:27152885

  15. Rotary motion driven by a direct current electric field

    OpenAIRE

    Takinoue, Masahiro; Atsumi, Yu; Yoshikawa, Kenichi

    2010-01-01

    We report the rotary motion of an aqueous microdroplet in an oil phase under a stationary direct current electric field. A droplet exhibits rotary motion under a suitable geometrical arrangement of positive and negative electrodes. Rotary motion appears above a certain critical electric potential and its frequency increases with an increase in the potential. A simple theoretical model is proposed to describe the occurrence of this rotary motion, together with an argument for the future expans...

  16. A bistable electromagnetically actuated rotary gate microvalve

    Science.gov (United States)

    Luharuka, Rajesh; Hesketh, Peter J.

    2008-03-01

    Two types of rotary gate microvalves are developed for flow modulation in microfluidic systems. These microvalves have been tested for an open flow rate of up to 100 sccm and operate under a differential pressure of 6 psig with flow modulation of up to 100. The microvalve consists of a suspended gate that rotates in the plane of the chip to regulate flow through the orifice. The gate is suspended by a novel fully compliant in-plane rotary bistable micromechanism (IPRBM) that advantageously constrains the gate in all degrees of freedom except for in-plane rotational motion. Multiple inlet/outlet orifices provide flexibility of operating the microvalve in three different flow configurations. The rotary gate microvalve is switched with an external electromagnetic actuator. The suspended gate is made of a soft magnetic material and its electromagnetic actuation is based on the operating principle of a variable-reluctance stepper motor.

  17. Rotary Percussive Auto-Gopher for Deep Drilling and Sampling

    Science.gov (United States)

    Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart

    2009-01-01

    The term "rotary percussive auto-gopher" denotes a proposed addition to a family of apparatuses, based on ultrasonic/ sonic drill corers (USDCs), that have been described in numerous previous NASA Tech Briefs articles. These apparatuses have been designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. In the case of the rotary percussive autogopher, the emphasis would be on developing an apparatus capable of penetrating to, and acquiring samples at, depths that could otherwise be reached only by use of much longer, heavier, conventional drilling-and-sampling apparatuses. To recapitulate from the prior articles about USDCs: A USDC can be characterized as a lightweight, low-power jackhammer in which a piezoelectrically driven actuator generates ultrasonic vibrations and is coupled to a tool bit through a free mass. The bouncing of the free mass between the actuator horn and the drill bit converts the actuator ultrasonic vibrations into sonic hammering of the drill bit. The combination of ultrasonic and sonic vibrations gives rise to a hammering action (and a resulting chiseling action at the tip of the tool bit) that is more effective for drilling than is the microhammering action of ultrasonic vibrations alone. The hammering and chiseling actions are so effective that the size of the axial force needed to make the tool bit advance into soil, rock, or another material of interest is much smaller than in ordinary rotary drilling, ordinary hammering, or ordinary steady pushing. The predecessor of the rotary percussive auto-gopher is an apparatus, now denoted an ultrasonic/sonic gopher and previously denoted an ultrasonic gopher, described in "Ultrasonic/ Sonic Mechanism for Drilling and Coring" (NPO-30291), NASA Tech Briefs Vol. 27, No. 9 (September 2003), page 65. The ultrasonic/sonic gopher is intended for use mainly in acquiring cores. The name of the apparatus reflects the fact that, like a

  18. 21 CFR 886.1665 - Ophthalmic rotary prism.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic rotary prism. 886.1665 Section 886.1665...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1665 Ophthalmic rotary prism. (a) Identification. An ophthalmic rotary prism is a device with various prismatic powers intended to be handheld and...

  19. Ka-band waveguide rotary joint

    KAUST Repository

    Yevdokymov, Anatoliy

    2013-04-11

    The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three circular choke grooves. Utilisation of three choke grooves allows larger operating clearance. Two prototypes of the rotary joint have been manufactured and experimentally studied. The observed loss is from 0.4 to 0.8 dB in 1.5 GHz band.

  20. Development of a novel rotary magnetic refrigerator

    DEFF Research Database (Denmark)

    Lozano, Jaime A.; Capovilla, Matheus S.; Trevizoli, Paulo V.

    2016-01-01

    with approximately 1.7 kg of gadolinium spheres (425-600 μm diameter) were placed in the magnetic gap. Two low-friction rotary valves were developed to synchronize the hydraulic and magnetic cycles. The valves were positioned at the hot end to avoid heat generation in the cold end. In this work, experimental results......A novel rotary magnetic refrigerator was designed and built at the Federal University of Santa Catarina (UFSC). The optimized magnetic circuit is a two-pole system in a rotor-stator configuration with high flux density regions of approximately 1 T. Eight pairs of stationary regenerator beds filled...

  1. Universal dynamic goniometer for rotary encoders

    Science.gov (United States)

    Smirnov, Nikolai V.; Latyev, Svjatoslav M.; Naumova, Anastasiia I.

    2017-06-01

    A novel dynamic goniometer for the accuracy of rotary encoders has been developed on the base of the method of comparison with the reference encoder. The set-up of the goniometer considers all constructive and informative characteristics of measured encoders. The novel goniometer construction uses the new compensating method of instrumental errors in automatic working process. The advantages of the dynamic goniometer in combination with an optical rotary encoder at the reduction of the measuring time and a simultaneous increase of the accuracy.

  2. Comparison between rotary and conventional flaring processes

    Science.gov (United States)

    Tamang, Subha; Bylya, Olga; Ward, Michael; Luo, Xichun; Halliday, Steven; Tuffs, Martin

    2017-10-01

    Rotary forming is one of the promising incremental processes. However, a wide industrial implementation of it strongly depends on the deep understanding of the mechanics of this process. This paper attempts to develop this understanding via a comparison of the rotary forming process with conventional flaring. Both the processes were simulated using commercial metal forming software QForm. The results of the simulation were validated by comparison with the experimental trials. The main focus was made on the triaxiality states taking place during forming, as it seems to be the main factor determining the success of the process.

  3. Optical Rotary Joint For Data Transfer

    Science.gov (United States)

    Becker, Fred J.

    1988-01-01

    Proposed joint increases bandwidth and reduces errors. Scheme for transferring digital data across rotary joint uses light instead of electrical signals. Optical joint offers greater bandwidth and operates at considerably lower error rate. Concept applied to transfer of highspeed data to rotating antennas or across joints of robots and manipulators in automated manufacturing.

  4. Precision Model for Microwave Rotary Vane Attenuator

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1979-01-01

    A model for a rotary vane attenuator is developed to describe the attenuator reflection and transmission coefficients in detail. All the parameters of the model can be measured in situ, i.e., without diassembling any part. The tranmission errors caused by internal reflections are calculated from...

  5. REACTIVATION OF FERRIC OXIDES IN ROTARY FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available The advantages of rotary furnaces, developed by specialists of GGTU named after P. O. Suhoj and UP «Tehnolit» for carrying out of ferric oxide recycling with regard to conditions of the Republic of Belarus, are described.

  6. Solid state lighting devices and methods with rotary cooling structures

    Science.gov (United States)

    Koplow, Jeffrey P.

    2017-03-21

    Solid state lighting devices and methods for heat dissipation with rotary cooling structures are described. An example solid state lighting device includes a solid state light source, a rotating heat transfer structure in thermal contact with the solid state light source, and a mounting assembly having a stationary portion. The mounting assembly may be rotatably coupled to the heat transfer structure such that at least a portion of the mounting assembly remains stationary while the heat transfer structure is rotating. Examples of methods for dissipating heat from electrical devices, such as solid state lighting sources are also described. Heat dissipation methods may include providing electrical power to a solid state light source mounted to and in thermal contact with a heat transfer structure, and rotating the heat transfer structure through a surrounding medium.

  7. Rotary Mode Core Sample System availability improvement

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, W.W.; Bennett, K.L.; Potter, J.D. [Westinghouse Hanford Co., Richland, WA (United States); Cross, B.T.; Burkes, J.M.; Rogers, A.C. [Southwest Research Institute (United States)

    1995-02-28

    The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2.

  8. GAS MOVEMENT IN ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of studies of gas movement and heat and mass transfer processes in the rotary tilting furnace (RTF at the heat treatment of disperse materials. The study was performed through computer modeling using software packages ANSYS CFX and Solid Works Flow Simulation. The results were used to design RTF with different capacity and application and helped to improve their technical and economic characteristics.

  9. INVESTIGATIONS ON OPERATION OF ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available Rotary tilting furnace (RTF is a new type of fuel furnaces, that provide the most efficient heating and recycling of polydisperse materials. The paper describes results of the investigations on thermal processes in the RTF, movement of materials and non-isothermal gas flow during kiln rotary process. The investigations have been carried out while using physical and computer simulations and under actual operating conditions applying the pilot plant. Results of the research have served as a basis for development of recommendations on the RTF calculations and designing and they have been also used for constructional design of a rotary tilting furnace for heating and melting of cast iron chips, reduction smelting of steel mill scale, melting of aluminum scrap, melting of lead from battery scrap. These furnaces have a high thermal efficiency (~50 %, technological flexibility, high productivity and profitability. Proven technical solutions for recycling of ferrous and non-ferrous metals develop the use of RTF in the foundry and metallurgical industry as the main technological unit for creation of cost-effective small-tonnage recycling of metal waste generated at the plants. The research results open prospects for organization of its own production for high-quality charging material in Belarus in lieu of imported primary metal. The proposed technology makes it possible to solve environmental challenge pertaining to liquidation of multi-tonnage heaps of metal-containing wastes.

  10. The Wankel rotary engine a history

    CERN Document Server

    Hege, John B

    2007-01-01

    "It stands apart from the crowd as the only history of the Wankel rotary engine that brings the story into the 21st Century"--SAH Journal; "this book continues to excel...terrific...technophiles will love this"--Hemmings Motor News; "excellent"--Hemmings Sports & Exotic Car; "a complete history...guaranteed to delight"--Old Cars Weekly; "definitive…a must-read"--Choice; "informative"--SciTech Book News; "goes a long way to explaining everything"--The Automobile. This complete and well-illustrated account traces the full history of the Wankel rotary engine and its use in various cars, motorcycles, snowmobiles and other applications. It clearly explains the working of the engine and the technical challenges it presented--the difficulty of designing effective and durable seals, early emissions troubles, high fuel consumption, and others. The work done by several companies to overcome these problems is described in detail, as are the economic and political troubles that nearly killed the rotary in the 19...

  11. Does intermittence in induced rotary movement have any explanatory significance?

    Science.gov (United States)

    Reinhardt-Rutland, A H

    1991-06-01

    Induced rotary movement has been reported to start and stop repeatedly during 1 min of observation. This has been taken as evidence for the involvement either of cyclorotational optokinetic nystagmus or of roll vection. Both assertions are dubious. Regarding cyclorotational optokinetic nystagmus, available evidence shows that it is too weak to be important in induced rotary movement. Also, induced rotary movement and cyclorotational optokinetic nystagmus are affected differently by the velocity of eliciting stimulation. Regarding roll vection, the conditions for its intermittence do not match those for induced rotary movement. Also, although aftereffects for induced rotary movement are negative, those for roll vection are positive and negative. Intermittence in induced rotary movement may be parsimoniously explained as characteristic of a weak effect.

  12. Analysis of Apex Seal Friction Power Loss in Rotary Engines

    Science.gov (United States)

    Handschuh, Robert F.; Owen, A. Karl

    2010-01-01

    An analysis of the frictional losses from the apex seals in a rotary engine was developed. The modeling was initiated with a kinematic analysis of the rotary engine. Next a modern internal combustion engine analysis code was altered for use in a rotary engine to allow the calculation of the internal combustion pressure as a function of rotor rotation. Finally the forces from the spring, inertial, and combustion pressure on the seal were combined to provide the frictional horsepower assessment.

  13. Numerical Analysis on Combustion Characteristic of Leaf Spring Rotary Engine

    OpenAIRE

    Yan Zhang; Zhengxing Zuo; Jinxiang Liu

    2015-01-01

    The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was used to illustrate the structure and principle of the engine. The aims are to (1) improve the understanding of combustion process, and (2) quantify the influence of rotational speed, excess air ratio, ...

  14. Tallinna Rotary klubi valis aasta politseiniku ja narkokoera

    Index Scriptorium Estoniae

    2006-01-01

    Tallinna Rotary klubi autasustas parima narkopolitseiniku preemiaga Lõuna politseiprefektuuri narkokuritegude talituse vaneminspektorit Jarek Pavlihhinit ning parima narkokoera tiitliga vene spanjelit Allrighti

  15. Material Research of Rotary Sealing Device for Combined Cutting System

    OpenAIRE

    Rui Zeng; Yong Zhang; Zhenrong Lin; Lulu Wang

    2017-01-01

    In order to solve the rotary sealing problem of rotary shaft in drum shearer combined cutting system, the material and structure of combined cutting system rotary sealing device needs to be selected and designed. In the paper, the rotary sealing structure of four grades in series was designed first, and then the material of NBR-40 and PTFE 4FT-4 under the separate static and dynamic sealing tests were carried out on the combined tooth-slip-ring sealing test-bed. The tests show that the NBR-40...

  16. Ultrasonic/Sonic Rotary-Hammer Drills

    Science.gov (United States)

    Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Kassab, Steve

    2010-01-01

    Ultrasonic/sonic rotary-hammer drill (USRoHD) is a recent addition to the collection of apparatuses based on ultrasonic/sonic drill corer (USDC). As described below, the USRoHD has several features, not present in a basic USDC, that increase efficiency and provide some redundancy against partial failure. USDCs and related apparatuses were conceived for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. They have been described in numerous previous NASA Tech Briefs articles. To recapitulate: A USDC can be characterized as a lightweight, lowpower, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. A basic USDC includes a piezoelectric stack, an ultrasonic transducer horn connected to the stack, a free mass ( free in the sense that it can bounce axially a short distance between hard stops on the horn and the bit), and a tool bit. The piezoelectric stack creates ultrasonic vibrations that are mechanically amplified by the horn. The bouncing of the free mass between the hard stops generates the sonic vibrations. The combination of ultrasonic and sonic vibrations gives rise to a hammering action (and a resulting chiseling action at the tip of the tool bit) that is more effective for drilling than is the microhammering action of ultrasonic vibrations alone. The hammering and chiseling actions are so effective that unlike in conventional twist drilling, little applied axial force is needed to make the apparatus advance into the material of interest. There are numerous potential applications for USDCs and related apparatuses in geological exploration on Earth and on remote planets. In early USDC experiments, it was observed that accumulation of cuttings in a drilled hole causes the rate of penetration of the USDC to decrease steeply with depth, and that the rate of penetration can be increased by removing the cuttings. The USRoHD concept provides for

  17. Multiscale molecular dynamics simulations of rotary motor proteins.

    Science.gov (United States)

    Ekimoto, Toru; Ikeguchi, Mitsunori

    2017-12-04

    Protein functions require specific structures frequently coupled with conformational changes. The scale of the structural dynamics of proteins spans from the atomic to the molecular level. Theoretically, all-atom molecular dynamics (MD) simulation is a powerful tool to investigate protein dynamics because the MD simulation is capable of capturing conformational changes obeying the intrinsically structural features. However, to study long-timescale dynamics, efficient sampling techniques and coarse-grained (CG) approaches coupled with all-atom MD simulations, termed multiscale MD simulations, are required to overcome the timescale limitation in all-atom MD simulations. Here, we review two examples of rotary motor proteins examined using free energy landscape (FEL) analysis and CG-MD simulations. In the FEL analysis, FEL is calculated as a function of reaction coordinates, and the long-timescale dynamics corresponding to conformational changes is described as transitions on the FEL surface. Another approach is the utilization of the CG model, in which the CG parameters are tuned using the fluctuation matching methodology with all-atom MD simulations. The long-timespan dynamics is then elucidated straightforwardly by using CG-MD simulations.

  18. Evolution of heat in dry rotary swaging

    Science.gov (United States)

    Herrmann, Marius; Liu, Yang; Schenck, Christian; Kuhfuss, Bernd; Ohlsen, Inken

    2017-10-01

    In dry metal forming processes, the heat dissipation is a critical issue. The cooling by the lubricant is missing. The different heat evolution affects the machine and the process and thus the final product. For the machine the thermal expansion is affected and needs to be considered. Also the tools can bear only a maximum heat load before they get damaged. Furthermore, the heat can influence the material properties like the flow stress if it exceeds a critical value. Furthermore, the process forces and the material flow are directly affected. In addition, heat modifies in combination with plastic strain the generated microstructure of the workpiece. If the heat is high enough even positive effects of cold forming like work hardening are drastically decreased. In summary, the heat evolution during lubricated and dry forming processes need to be investigated. The evolution of heat in rotary swaging was investigated with conventional tools and machine settings. This was realized by varying the feeding velocity for the lubricated forming of aluminum tubes (3.3206) and steel tubes (1.0308). Moreover, the steel tubes are also formed with conventional tools by dry rotary swaging. A temperature measurement was integrated inside the tubes during the rotary process. Thus, the heat evolution inside the tube during the process at two different positions was examined. Also the variation between inside the tubes and the surface of the tubes was investigated by measuring the temperature at the surface directly after the forming process. Comparisons between different measured heat evolutions represent the impact of lubrication, feed rate and material. Thus, the practicability and the challenge for dry forming processes are presented.

  19. Features of rotary pump diagnostics without dismantling

    Directory of Open Access Journals (Sweden)

    Sergeev K. О.

    2017-12-01

    Full Text Available In ship power plants, rotor pumps have become very popular providing the transfer of various viscous fluids: fuels, oils, etc. Like all ship's mechanisms, pumps need proper maintenance and monitoring of technical condition. The most expedient is maintenance and repair carried out according to the results of dismantling diagnosis. The methods of vibrodiagnostics are mostly widespread for the diagnosis of pumps. Vibrodiagnosis of rotary pumps has a number of features due to the nature and condition of pumped fluids. The norms of the Russian Maritime Register of Shipping are used for setting standards of vibration and diagnostics of the rotary pumps' technical condition. To clarify the features of vibration diagnostics of rotary pumps some measurements have been made on a special bench that simulates various modes of ship's pumps' operation: different pressure in the system and temperature of the pumped medium. As a result of measurements one-third octave and narrow-band vibration spectra of pumps have been obtained at various developed pressures and temperatures of the pumped fluid. The performed analysis has shown that the RMRS norms for diagnostics of ship rotary pumps have insufficient informative value inasmuch they do not take into account the dependence of the vibrational signal spectrum on the developed pressure and temperature of the pumped fluid. The nature of the received signals shows that the levels of a third-octave spectrum of the vibration velocity depend significantly on the temperature of the pumped fluids, this fact must be taken into account when applying the RMRS norms. The fluid temperature has a great influence on the nature of the narrow-band vibration acceleration spectrum in the area of medium frequencies, less influence – on the nature of the vibration velocity spectrum. The conclusions have been drawn about the advisability of using the narrow-band vibration spectra and the envelope spectra of the high

  20. Static Model of Cement Rotary Kiln

    Directory of Open Access Journals (Sweden)

    Omar D. Hernández-Arboleda

    2013-11-01

    Full Text Available In this paper, a static model of cement rotary kilns is proposed. The system model is obtained through polynomial series. The proposed model is contrasted with data of a real plant, where optimal results are obtained. Expected results are measured with respect to the clinker production and the combustible consumption is measured in relation with the consumption calorific. The expected result of the approach is the increase of the profitability of the factory through the decrease of the consumption of the combustible.

  1. Design Robust Controller for Rotary Kiln

    Directory of Open Access Journals (Sweden)

    Omar D. Hernández-Arboleda

    2013-11-01

    Full Text Available This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR, these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity applied to the entire model (controller-plant, obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system.

  2. Rotary Wing Deceleration Use on Titan

    Science.gov (United States)

    Young, Larry A.; Steiner, Ted J.

    2011-01-01

    Rotary wing decelerator (RWD) systems were compared against other methods of atmospheric deceleration and were determined to show significant potential for application to a system requiring controlled descent, low-velocity landing, and atmospheric research capability on Titan. Design space exploration and down-selection results in a system with a single rotor utilizing cyclic pitch control. Models were developed for selection of a RWD descent system for use on Titan and to determine the relationships between the key design parameters of such a system and the time of descent. The possibility of extracting power from the system during descent was also investigated.

  3. Rotary International and Career Education. Monographs on Career Education.

    Science.gov (United States)

    Hoyt, Kenneth B.

    Based on a series of mini-conferences, this monograph presents ideas and thoughts of members of the Rotary International organization on the concept of collaboration in career education. First, a brief description of Rotary International is provided. Next, several specific examples are given of ways in which local clubs are already involved in…

  4. Streaming current of a rotary atomizer for energy harvesting

    NARCIS (Netherlands)

    Nguyen, Trieu; de Boer, Hans L.; Tran, T.; van den Berg, Albert; Eijkel, Jan C.T.; Zengerle, R.

    2013-01-01

    We present the experimental results of an energy conversion system based on a rotary atomizer and the streaming current phenomenon. The advantage of using a rotary atomizer instead of a channel or membrane micropore as in conventional pressure-driven approached is that the centrifugal force exerted

  5. Rate acceleration of light-driven rotary molecular motors

    NARCIS (Netherlands)

    Pollard, Michael M.; Klok, Martin; Pijper, Dirk; Feringa, Ben L.

    2007-01-01

    One of the key challenges in taking light-driven unidirectional rotary motors from discovery to application is to increase the rate of rotation. Herein, we review our ongoing efforts to address this issue by meticulous improvement to the molecular design. To accelerate the rotary cycle, we have

  6. THE MOVEMENT AND MIXING OF DISPERSED MATERIALS IN ROTARY FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2017-01-01

    Full Text Available This article describes motion and heat and mass transfer in the layer of dispersed material in a rotary furnace. Presents the results of a comprehensive study of these processes, including pilot studies, computer modeling and simulation, which allow to optimize the design and process parameters of rotary furnaces.

  7. A thin membrane artificial muscle rotary motor

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain A.; Hale, Thom; Gisby, Todd; Inamura, Tokushu; McKay, Thomas; O' Brien, Benjamin; Walbran, Scott [University of Auckland, The Biomimetics Lab, Auckland Bioengineering Institute, Auckland (New Zealand); Calius, Emilio P. [Industrial Research Ltd., P.O. Box 2225, Auckland (New Zealand)

    2010-01-15

    Desirable rotary motor attributes for robotics include the ability to develop high torque in a low mass body and to generate peak power at low rotational speeds. Electro-active polymer artificial muscles offer promise as actuator elements for robotic motors. A promising artificial muscle technology for use as a driving mechanism for rotary motion is the dielectric elastomer actuator (DEA). We present a membrane DEA motor in which phased actuation of electroded sectors of the motor membrane impart orbital motion to a central drive that turns a rotor. The motor is inherently scalable, flexible, flat, silent in operation, amenable to deposition-based manufacturing approaches, and uses relatively inexpensive materials. As a membrane it can also form part of the skin of a robot. We have investigated the torque and power of stacked membrane layers. Specific power and torque ratios when calculated using active membrane mass only were 20.8 W/kg and 4.1 Nm/kg, respectively. These numbers compare favorably with a commercially available stepper motor. Multi-membrane fabrication substantially boosts torque and power and increases the active mass of membrane relative to supporting framework. Through finite element modeling, we show the mechanisms governing the maximum torque the device can generate and how the motor can be improved. (orig.)

  8. A thin membrane artificial muscle rotary motor

    Science.gov (United States)

    Anderson, Iain A.; Hale, Thom; Gisby, Todd; Inamura, Tokushu; McKay, Thomas; O'Brien, Benjamin; Walbran, Scott; Calius, Emilio P.

    2010-01-01

    Desirable rotary motor attributes for robotics include the ability to develop high torque in a low mass body and to generate peak power at low rotational speeds. Electro-active polymer artificial muscles offer promise as actuator elements for robotic motors. A promising artificial muscle technology for use as a driving mechanism for rotary motion is the dielectric elastomer actuator (DEA). We present a membrane DEA motor in which phased actuation of electroded sectors of the motor membrane impart orbital motion to a central drive that turns a rotor. The motor is inherently scalable, flexible, flat, silent in operation, amenable to deposition-based manufacturing approaches, and uses relatively inexpensive materials. As a membrane it can also form part of the skin of a robot. We have investigated the torque and power of stacked membrane layers. Specific power and torque ratios when calculated using active membrane mass only were 20.8 W/kg and 4.1 Nm/kg, respectively. These numbers compare favorably with a commercially available stepper motor. Multi-membrane fabrication substantially boosts torque and power and increases the active mass of membrane relative to supporting framework. Through finite element modeling, we show the mechanisms governing the maximum torque the device can generate and how the motor can be improved.

  9. Rotary radiators for reduced space powerplant temperatures

    Science.gov (United States)

    Elliott, D. G.

    If new radiator concepts can achieve radiator weights below 3 kg/sq m, nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction. Tube-and-fin or heat-pipe radiators weigh at least 5 kg/sq m because the tube walls must be thick enough to prevent or limit meteoroid punctures. However, radiators that require no meteoroid protection can be built using low-vapor-pressure liquids that can be exposed directly to space. One possible design for such a radiator is the 'rotary radiator' that uses centrifugal force to move the liquid across a thin radiating disk and uses surface tension to retain the liquid despite meteoroid punctures.

  10. Conceptual design of rotary magnetostrictive energy harvester

    Science.gov (United States)

    Park, Young-Woo; Kang, Han-Sam; Wereley, Norman M.

    2014-05-01

    This paper presents the conceptual design of a rotary magnetostrictive energy harvester (RMEH), which consists of one coil-wound Galfenol cantilever, with two PMs adhered onto the each end, and one permanent magnet (PM) array sandwiched between two wheels. Modeling and simulation are used to validate the concept. The proof-of-concept RMEH is fabricated by using the simulation results, and subjected to the experimental characterization. The experimental setup for the simulated characterization uses the motor-driven PM array to induce a forced vibration. It can be concluded that the theoretical prediction on the induced voltage agrees well with the experimental results and that induced voltage increases with rpm and with number of PMs. Future work includes optimization of RMEH performance via PM array configuration and development of prototype.

  11. Film riding seals for rotary machines

    Science.gov (United States)

    Bidkar, Rahul Anil; Sarawate, Neelesh Nandkumar; Wolfe, Christopher Edward; Ruggiero, Eric John; Raj Mohan, Vivek Raja

    2017-03-07

    A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having one or more labyrinth teeth therebetween facing the rotor. The sealing device includes a stator interface element having a groove or slot for allowing disposal of a spline seal for preventing segment leakages. The sealing device segment also includes multiple bellow springs or flexures connected to the shoe plate and to the stator interface element. Further, the sealing device segments include a secondary seal integrated with the stator interface element at one end and positioned about the multiple bellow springs or flexures and the shoe plate at the other end.

  12. Rotary seal with improved film distribution

    Science.gov (United States)

    Dietle, Lannie Laroy; Schroeder, John Erick

    2013-10-08

    The present invention is a generally circular rotary seal that establishes sealing between relatively rotatable machine components for lubricant retention and environmental exclusion, and incorporates seal geometry that interacts with the lubricant during relative rotation to distribute a lubricant film within the dynamic sealing interface. The features of a variable inlet size, a variable dynamic lip flank slope, and a reduction in the magnitude and circumferentially oriented portion of the lubricant side interfacial contact pressure zone at the narrowest part of the lip, individually or in combination thereof, serve to maximize interfacial lubrication in severe operating conditions, and also serve to minimize lubricant shear area, seal torque, seal volume, and wear, while ensuring retrofitability into the seal grooves of existing equipment.

  13. A rotary motor drives Flavobacterium gliding.

    Science.gov (United States)

    Shrivastava, Abhishek; Lele, Pushkar P; Berg, Howard C

    2015-02-02

    Cells of Flavobacterium johnsoniae, a rod-shaped bacterium devoid of pili or flagella, glide over glass at speeds of 2-4 μm/s [1]. Gliding is powered by a protonmotive force [2], but the machinery required for this motion is not known. Usually, cells move along straight paths, but sometimes they exhibit a reciprocal motion, attach near one pole and flip end over end, or rotate. This behavior is similar to that of a Cytophaga species described earlier [3]. Development of genetic tools for F. johnsoniae led to discovery of proteins involved in gliding [4]. These include the surface adhesin SprB that forms filaments about 160 nm long by 6 nm in diameter, which, when labeled with a fluorescent antibody [2] or a latex bead [5], are seen to move longitudinally down the length of a cell, occasionally shifting positions to the right or the left. Evidently, interaction of these filaments with a surface produces gliding. To learn more about the gliding motor, we sheared cells to reduce the number and size of SprB filaments and tethered cells to glass by adding anti-SprB antibody. Cells spun about fixed points, mostly counterclockwise, rotating at speeds of 1 Hz or more. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. However, we found that a gliding motor runs at constant speed rather than at constant torque. Now, there are three rotary motors powered by protonmotive force: the bacterial flagellar motor, the Fo ATP synthase, and the gliding motor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Rotary endodontics in primary teeth – A review

    Directory of Open Access Journals (Sweden)

    Sageena George

    2016-01-01

    Full Text Available Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel–titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed.

  15. Rotary klubi tuli rannarahvale appi / Anu Jürisson

    Index Scriptorium Estoniae

    Jürisson, Anu

    2005-01-01

    Tallinna Vanalinna Rotary klubi kinkis kolmele Rannametsa perele kümme tuhat krooni jaanuaritormi kahjustuste likvideerimiseks. Klubi presidendiks on Allan Martinson, nimekirjas ka Tõnis Palts, Toomas Hendrik Ilves, Rein Kilk, Hans H. Luik, Vahur Kraft jt.

  16. Material Research of Rotary Sealing Device for Combined Cutting System

    Directory of Open Access Journals (Sweden)

    Rui Zeng

    2017-01-01

    Full Text Available In order to solve the rotary sealing problem of rotary shaft in drum shearer combined cutting system, the material and structure of combined cutting system rotary sealing device needs to be selected and designed. In the paper, the rotary sealing structure of four grades in series was designed first, and then the material of NBR-40 and PTFE 4FT-4 under the separate static and dynamic sealing tests were carried out on the combined tooth-slip-ring sealing test-bed. The tests show that the NBR-40 O-Ring with PTFE 4FT-4 tooth-slip-ring has no low-pressure leakage problem and low leakage in the sealing progress, the sealing effect of which is the best.

  17. Precision goniometer equipped with a 22-bit absolute rotary encoder.

    Science.gov (United States)

    Xiaowei, Z; Ando, M; Jidong, W

    1998-05-01

    The calibration of a compact precision goniometer equipped with a 22-bit absolute rotary encoder is presented. The goniometer is a modified Huber 410 goniometer: the diffraction angles can be coarsely generated by a stepping-motor-driven worm gear and precisely interpolated by a piezoactuator-driven tangent arm. The angular accuracy of the precision rotary stage was evaluated with an autocollimator. It was shown that the deviation from circularity of the rolling bearing utilized in the precision rotary stage restricts the angular positioning accuracy of the goniometer, and results in an angular accuracy ten times larger than the angular resolution of 0.01 arcsec. The 22-bit encoder was calibrated by an incremental rotary encoder. It became evident that the accuracy of the absolute encoder is approximately 18 bit due to systematic errors.

  18. Axial squeeze strengthen effect on rotary magneto-rheological damper

    Science.gov (United States)

    Dong, Xiaomin; Duan, Chi; Yu, Jianqiang

    2017-05-01

    Pressure is an important factor to influence the performance of an magneto-rheological (MR) apparatus. The effect of the axial squeeze strengthen effect on rotary MR damper is investigated theoretically and experimentally in this study. First, a theoretical analysis in a microscopic view is proposed. It indicates that a concentrated increment of iron particle content in the working gap results in the effect. Then, a pressure-controlled rotary MR damper with the axial squeeze strengthen effect is designed, manufactured and tested. The results show that the axial squeeze strengthen effect on rotary MR damper is remarkable for the damper with lower particle content in MR fluids. In addition, there is an optimal pressure to obtain the maximum axial squeeze strengthen effect on the rotary MR damper.

  19. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    CERN Document Server

    Foust, D J

    2000-01-01

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

  20. Rotary endodontics in primary teeth – A review

    Science.gov (United States)

    George, Sageena; Anandaraj, S.; Issac, Jyoti S.; John, Sheen A.; Harris, Anoop

    2015-01-01

    Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel–titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed. PMID:26792964

  1. ROTARY FURNACES FOR THERMAL PROCESSING AND DRYING OF POLYDISPERSE MATERIALS

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2006-01-01

    Full Text Available It is shown that rotary furnaces and drying ovens are a perspective type of furnaces, allowing to solve a number of problems in conditions of flexible production and strong resources economy

  2. Design study of a high power rotary transformer

    Science.gov (United States)

    Weinberger, S. M.

    1982-01-01

    A design study was made on a rotary transformer for transferring electrical power across a rotating spacecraft interface. The analysis was performed for a 100 KW, 20 KHz unit having a ""pancake'' geometry. The rotary transformer had a radial (vertical) gap and consisted of 4-25 KW modules. It was assumed that the power conditioning comprised of a Schwarz resonant circuit with a 20 KHz switching frequency. The rotary transformer, mechanical and structural design, heat rejection system and drive mechanism which provide a complete power transfer device were examined. The rotary transformer losses, efficiency, weight and size were compared with an axial (axial symmetric) gap transformer having the same performance requirements and input characteristics which was designed as part of a previous program. The ""pancake'' geometry results in a heavier rotary transformer primarily because of inefficient use of the core material. It is shown that the radial gap rotary transformer is a feasible approach for the transfer of electrical power across a rotating interface and can be implemented using presently available technology.

  3. TESTING OF THE DUAL ROTARY FILTER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.; Fowley, M.; Stefanko, D.

    2011-08-29

    The Savannah River National Laboratory (SRNL) installed and tested two hydraulically connected SpinTek rotary microfilter (RMF) units to determine the behavior of a multiple filter system. Both units were successfully controlled by a control scheme written in DELTA-V architecture by Savannah River Remediation (SRR) Process Control Engineering personnel. The control system was tuned to provide satisfactory response to changing conditions during the operation of the multi-filter system. Stability was maintained through the startup and shutdown of one of the filter units while the second was still in operation. The installation configuration originally proposed by the Small Colum Ion Exchange (SCIX) project of independent filter and motor mountings may be susceptible to vibration. Significant stiffening of the filter and motor mounts was required to minimize the vibration. Alignment of the motor to the filter was a challenge in this test configuration. The deployment configuration must be easy to manipulate and allow for fine adjustment. An analysis of the vibration signature of the test system identified critical speeds. Whether it corresponds to the resonance frequency of a rotor radial vibration mode that was excited by rotor unbalance is uncertain based upon the measurements. A relative motion series should be completed on the filter with the final shaft configuration to determine if the resonances exist in the final filter design. The instrumentation selected for deployment, including the concentrate discharge control valve and flow meters, performed well. Automation of the valve control integrated well with the control scheme and when used in concert with the other control variables, allowed automated control of the dual RMF system. The one area of concern with the instrumentation was the condition resulting when the filtrate flow meter operated with less than three gpm. This low flow was at the lower range of performance for the flow meter. This should not be

  4. A Comparison of Apical Bacterial Extrusion in Manual, ProTaper Rotary, and One Shape Rotary Instrumentation Techniques.

    Science.gov (United States)

    Mittal, Rakesh; Singla, Meenu G; Garg, Ashima; Dhawan, Anu

    2015-12-01

    Apical extrusion of irrigants and debris is an inherent limitation associated with cleaning and shaping of root canals and has been studied extensively because of its clinical relevance as a cause of flare-ups. Many factors affect the amount of extruded intracanal materials. The purpose of this study was to assess the bacterial extrusion by using manual, multiple-file continuous rotary system (ProTaper) and single-file continuous rotary system (One Shape). Forty-two human mandibular premolars were inoculated with Enterococcus faecalis by using a bacterial extrusion model. The teeth were divided into 3 experimental groups (n = 12) and 1 control group (n = 6). The root canals of experimental groups were instrumented according to the manufacturers' instructions by using manual technique, ProTaper rotary system, or One Shape rotary system. Sterilized saline was used as an irrigant, and bacterial extrusion was quantified as colony-forming units/milliliter. The results obtained were statistically analyzed by using one-way analysis of variance for intergroup comparison and post hoc Tukey test for pair-wise comparison. The level for accepting statistical significance was set at P rotary extruded significantly more bacteria than One Shape rotary system (P < .05). The engine-driven nickel-titanium systems were associated with less apical extrusion. The instrument design may play a role in amount of extrusion. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Percussive Augmenter of Rotary Drills for Operating as a Rotary-Hammer Drill

    Science.gov (United States)

    Aldrich, Jack Barron (Inventor); Bar-Cohen, Yoseph (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Scott, James Samson (Inventor)

    2014-01-01

    A percussive augmenter bit includes a connection shaft for mounting the bit onto a rotary drill. In a first modality, an actuator percussively drives the bit, and an electric slip-ring provides power to the actuator while being rotated by the drill. Hammering action from the actuator and rotation from the drill are applied directly to material being drilled. In a second modality, a percussive augmenter includes an actuator that operates as a hammering mechanism that drives a free mass into the bit creating stress pulses that fracture material that is in contact with the bit.

  6. Chemically optimizing operational efficiency of molecular rotary motors.

    Science.gov (United States)

    Conyard, Jamie; Cnossen, Arjen; Browne, Wesley R; Feringa, Ben L; Meech, Stephen R

    2014-07-09

    Unidirectional molecular rotary motors that harness photoinduced cis-trans (E-Z) isomerization are promising tools for the conversion of light energy to mechanical motion in nanoscale molecular machines. Considerable progress has been made in optimizing the frequency of ground-state rotation, but less attention has been focused on excited-state processes. Here the excited-state dynamics of a molecular motor with electron donor and acceptor substituents located to modify the excited-state reaction coordinate, without altering its stereochemistry, are studied. The substituents are shown to modify the photochemical yield of the isomerization without altering the motor frequency. By combining 50 fs resolution time-resolved fluorescence with ultrafast transient absorption spectroscopy the underlying excited-state dynamics are characterized. The Franck-Condon excited state relaxes in a few hundred femtoseconds to populate a lower energy dark state by a pathway that utilizes a volume conserving structural change. This is assigned to pyramidalization at a carbon atom of the isomerizing bridging double bond. The structure and energy of the dark state thus reached are a function of the substituent, with electron-withdrawing groups yielding a lower energy longer lived dark state. The dark state is coupled to the Franck-Condon state and decays on a picosecond time scale via a coordinate that is sensitive to solvent friction, such as rotation about the bridging bond. Neither subpicosecond nor picosecond dynamics are sensitive to solvent polarity, suggesting that intramolecular charge transfer and solvation are not key driving forces for the rate of the reaction. Instead steric factors and medium friction determine the reaction pathway, with the sterically remote substitution primarily influencing the energetics. Thus, these data indicate a chemical method of optimizing the efficiency of operation of these molecular motors without modifying their overall rotational frequency.

  7. Reaction force of percussive corer, rotary-friction corer, and rotary-percussive corer

    Science.gov (United States)

    Chang, Zensheu; Sherrit, Stewart; Badescu, Mircea; Bao, Xiaoqi; Bar-Cohen, Yoseph; Backes, Paul

    2006-01-01

    Future NASA exploration missions will increasingly require sampling, in-situ analysis and possibly the return of material to Earth for laboratory analysis. To address these objective, effective and optimized drilling techniques are needed. This requires developing comprehensive tools to be able to determine analytically what takes place during the operation and what are the control parameters that can be enhanced. In this study, three types of coring techniques were studied and were identified as potential candidates for operation from a possible future Mars Sample Return (MSR) mission rover. These techniques include percussive, rotary-friction, and rotary-percussive coring. Theoretical models were developed to predict the dynamic reaction forces transmitted from these three types of corers to the robotic arms that hold them. The predicted reaction forces will then be used in a dynamic simulation environment to simulate a representative corer tool to obtain a best estimate of a tool that can be operated from a small rover. The predicted dynamic reaction forces will be presented in this paper.

  8. Sterilization of rotary NiTi instruments within endodontic sponges.

    Science.gov (United States)

    Chan, H W A; Tan, K H; Dashper, S G; Reynolds, E C; Parashos, P

    2015-08-17

    To determine whether the following can be sterilized by autoclaving - endodontic sponges, rotary nickel-titanium (NiTi) instruments within endodontic sponges, and rotary NiTi instruments with rubber stoppers. Sixty-four samples of eight different endodontic sponges (n = 512) were placed into brain heart infusion broth (BHI) for 72 h. An aliquot of this was then spread onto horse blood agar and cultured aerobically and anaerobically to test sterility at purchase. Bacterial suspensions of Enterococcus faecalis, Porphyromonas gingivalis and Geobacillus stearothermophilus in BHI were used to contaminate sterile sponges and rotary NiTi instruments (with and without rubber stoppers) inserted into sponges. The various samples were autoclaved and then cultured aerobically and anaerobically. Success of sterilization was measured qualitatively as no growth. The experiment was repeated with clinically used rotary NiTi instruments (n = 512). All experiments were conducted in quadruplicate. No sponges on purchase had microbial growth when anaerobically cultured but some did when aerobically cultured. All autoclaved sponges and instruments (within or without sponges, and with or without rubber stoppers) were associated with no microbial growth. All nonautoclaved positive control samples showed microbial growth. Autoclaving was effective in the sterilization of sponges and endodontic instruments. Endodontic sponges should be autoclaved before clinical use. For clinical efficiency and cost-effectiveness, rotary NiTi instruments can be sterilized in endodontic sponges without removal of rubber stoppers. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  9. Planar Rotary Piezoelectric Motor Using Ultrasonic Horns

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Geiyer, Daniel; Ostlund, Patrick N.; Allen, Phillip

    2011-01-01

    A motor involves a simple design that can be embedded into a plate structure by incorporating ultrasonic horn actuators into the plate. The piezoelectric material that is integrated into the horns is pre-stressed with flexures. Piezoelectric actuators are attractive for their ability to generate precision high strokes, torques, and forces while operating under relatively harsh conditions (temperatures at single-digit K to as high as 1,273 K). Electromagnetic motors (EM) typically have high rotational speed and low torque. In order to produce a useful torque, these motors are geared down to reduce the speed and increase the torque. This gearing adds mass and reduces the efficiency of the EM. Piezoelectric motors can be designed with high torques and lower speeds directly without the need for gears. Designs were developed for producing rotary motion based on the Barth concept of an ultrasonic horn driving a rotor. This idea was extended to a linear motor design by having the horns drive a slider. The unique feature of these motors is that they can be designed in a monolithic planar structure. The design is a unidirectional motor, which is driven by eight horn actuators, that rotates in the clockwise direction. There are two sets of flexures. The flexures around the piezoelectric material are pre-stress flexures and they pre-load the piezoelectric disks to maintain their being operated under compression when electric field is applied. The other set of flexures is a mounting flexure that attaches to the horn at the nodal point and can be designed to generate a normal force between the horn tip and the rotor so that to first order it operates independently and compensates for the wear between the horn and the rotor.

  10. Analysis of the dynamic characteristics of gas chamber in rotary hammer

    National Research Council Canada - National Science Library

    YAN, Shiwei; HUANG, Shangyu; ZOU, Fangli

    2016-01-01

    Rotary hammer is a high-frequency impact machine with a complicated gas chamber. The design parameters of the gas chamber are dominating to impact energy output and impact efficiency of a rotary hammer...

  11. Development of the RANCOR Rotary-Percussive Coring System for Mars Sample Return

    Science.gov (United States)

    Paulsen, Gale; Indyk, Stephen; Zacny, Kris

    2014-01-01

    A RANCOR drill was designed to fit a Mars Exploration Rover (MER) class vehicle. The low mass of 3 kg was achieved by using the same actuator for three functions: rotation, percussions, and core break-off. Initial testing of the drill exposed an unexpected behavior of an off-the-shelf sprag clutch used to couple and decouple rotary-percussive function from the core break off function. Failure of the sprag was due to the vibration induced during percussive drilling. The sprag clutch would back drive in conditions where it was expected to hold position. Although this did not affect the performance of the drill, it nevertheless reduced the quality of the cores produced. Ultimately, the sprag clutch was replaced with a custom ratchet system that allowed for some angular displacement without advancing in either direction. Replacing the sprag with the ratchet improved the collected core quality. Also, premature failure of a 300-series stainless steel percussion spring was observed. The 300-series percussion spring was ultimately replaced with a music wire spring based on performances of previously designed rotary-percussive drill systems.

  12. 16 CFR 1205.4 - Walk-behind rotary power mower protective shields.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Walk-behind rotary power mower protective... SAFETY ACT REGULATIONS SAFETY STANDARD FOR WALK-BEHIND POWER LAWN MOWERS The Standard § 1205.4 Walk-behind rotary power mower protective shields. (a) General requirements. Walk-behind rotary power mowers...

  13. 40 CFR 63.2263 - Initial compliance demonstration for a dry rotary dryer.

    Science.gov (United States)

    2010-07-01

    ... dry rotary dryer. 63.2263 Section 63.2263 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Initial Compliance Requirements § 63.2263 Initial compliance demonstration for a dry rotary dryer. If you operate a dry rotary dryer, you must demonstrate that your dryer processes furnish with an inlet moisture...

  14. Development of Laser Propelled ``Semi-Perpetual'' Rotary Machine

    Science.gov (United States)

    Gualini, M. M.; Khan, S. A.; Zulfiqar, K.

    2006-05-01

    This paper covers the initial work oriented to develop a semi-perpetual rotary machine propelled by laser ablation propulsion. The laser is equipped with a pulse repetition frequency tuned to the rotational frequency of the flying wheel. Purpose of this work is to establish the potentiality of a self-sustained closed system capable of generating kinetic rotary energy which can be exploited for traction of vehicles and production of electrical energy at very low cost. The work presented is in process of being patented.

  15. Analysis on design and performance of a solar rotary house

    Science.gov (United States)

    Fan, Xuhong; Zhang, Zhaochang; Yang, Fan; Cao, Lilin; Xu, Jing; Yuan, Mingyang

    2017-04-01

    A solar rotary house is designed, composed of rotating main structure, fixed cylinder, rotating drive system, solar photovoltaic system and so on, to achieve 360° rotation. Thus it can change the dark and humid situation of the traditional fixed house shade. Its bearing capacity, driving force and safety are analyzed. Rotary driving force and living energy are provided by solar photovoltaic system on roofs and walls. The Phonenics, Ecotect simulation analysis conclude that the rotating house indoor has better natural ventilation effect, more uniform lighting, better the sunshine time compared with traditional houses, becoming a green, energy-saving, comfortable building model.

  16. Surfzone Monitoring Using Rotary Wing Unmanned Aerial Vehicles

    OpenAIRE

    Brouwer, Ronald L.; De Schipper, Matthiew A.; Rynne, Patrick F.; Graham, Fiona J.; Reniers, J.H.M.; MacMahan, Jamie H.

    2015-01-01

    The article of record as published may be found at http://dx.doi.org/10.1175/JTECH-D-14-00122.1 This study investigates the potential of rotary wing unmanned aerial vehicles (UAVs) to monitor the surfzone. This paper shows that these UAVs are extremely flexible surveying platforms that can gather nearcontinuous moderate spatial resolution and high temporal resolution imagery from a fixed position high above a study site. The rotary wing UAVs used in this study can fly for ;12 min ...

  17. Analysis of angular heat conduction in rotary heat regenerators

    Energy Technology Data Exchange (ETDEWEB)

    Reis, M.C.; Sphaier, L.A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica. Lab. de Mecanica Teorica e Aplicada], Emails: lasphaier@mec.uff.br, marcelloreis@vm.uff.br

    2010-07-01

    Heat regenerators can be found in a considerable number of engineering applications, and are either used as pair of fixed matrices or as single rotary matrix. The thermal design of these devices is usually done considering models that rely on well-established simplifying assumptions. While most of these assumptions comprise reasonable considerations, some of them could lead to noticeable errors on some occasions. One such assumption is that there is no heat transfer between adjacent channels within the regenerator matrix. While this is quite reasonable for fixed-bed exchangers, this might not be a good choice for rotary exchangers on some occasions. Since rotary matrices can operate between two process streams presenting a large temperature difference between them, a large temperature gradient may develop within the plane normal to the flow direction, especially in the angular direction. This paper proposes a new model for simulating rotary heat regenerators, taking into account this previously unconsidered matrix heat conduction effect. A numerical solution of a test case with angular heat conduction is carried-out. With this solution, a parametric analysis is performed, showing how the effects that gradually increasing the angular heat conduction can affect the temperature distributions within the matrix and regenerator outlet. (author)

  18. Evaluation of surface characteristics of rotary nickel‑titanium ...

    African Journals Online (AJOL)

    2015-05-26

    May 26, 2015 ... stainless steel instruments.[1] NiTi instruments ... and converted back to an austenite structure by heating and cooling again. .... Effect of heat treatment on cyclic fatigue resistance, thermal behavior and microstructures of K3 NiTi rotary instruments. Acta Odontol Scand 2013;71:1656‑62. 7. Kim HC, Yum J, ...

  19. Mass transfer in rolling rotary kilns: a novel approach

    NARCIS (Netherlands)

    Heydenrych, M.D.; Greeff, P.; Heesink, Albertus B.M.; Versteeg, Geert

    2002-01-01

    A novel approach to modeling mass transfer in rotary kilns or rotating cylinders is explored. The movement of gas in the interparticle voids in the bed of the kiln is considered, where particles move concentrically with the geometry of the kiln and gas is entrained by these particles. The approach

  20. Equivalent Circuit Modeling of a Rotary Piezoelectric Motor

    DEFF Research Database (Denmark)

    El, Ghouti N.; Helbo, Jan

    2000-01-01

    In this paper, an enhanced equivalent circuit model of a rotary traveling wave piezoelectric ultrasonic motor "shinsei type USR60" is derived. The modeling is performed on the basis of an empirical approach combined with the electrical network method and some simplification assumptions about...

  1. Equivalent Circuit Modeling of a Rotary Piezoelectric Motor

    DEFF Research Database (Denmark)

    El, Ghouti N.; Helbo, Jan

    2000-01-01

    In this paper, an enhanced equivalent circuit model of a rotary traveling wave piezoelectric ultrasonic motor "shinsei type USR60" is derived. The modeling is performed on the basis of an empirical approach combined with the electrical network method and some simplification assumptions about the ...

  2. Chemically Optimizing Operational Efficiency of Molecular Rotary Motors

    NARCIS (Netherlands)

    Conyard, Jamie; Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Meech, Stephen R.

    2014-01-01

    Unidirectional molecular rotary motors that harness photoinduced cis-trans (E-Z) isomerization are promising tools for the conversion of light energy to mechanical motion in nanoscale molecular machines. Considerable progress has been made in optimizing the frequency of ground-state rotation, but

  3. Fixed atlantoaxial rotary deformity with bilateral facet dislocation

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, G.Y.; Clark, C.R.; Wroble, R.R.

    1985-03-01

    A 21-year-old patient with Down syndrome who developed rotary atlantoaxial dislocation of C1 and C2 following an upper respiratory infection is presented. Techniques for detection and quantification of this potentially serious dislocation using multidirectional tomography and computerized tomography are described.

  4. Rotary ATPases: models, machine elements and technical specifications.

    Science.gov (United States)

    Stewart, Alastair G; Sobti, Meghna; Harvey, Richard P; Stock, Daniela

    2013-01-01

    Rotary ATPases are molecular rotary motors involved in biological energy conversion. They either synthesize or hydrolyze the universal biological energy carrier adenosine triphosphate. Recent work has elucidated the general architecture and subunit compositions of all three sub-types of rotary ATPases. Composite models of the intact F-, V- and A-type ATPases have been constructed by fitting high-resolution X-ray structures of individual subunits or sub-complexes into low-resolution electron densities of the intact enzymes derived from electron cryo-microscopy. Electron cryo-tomography has provided new insights into the supra-molecular arrangement of eukaryotic ATP synthases within mitochondria and mass-spectrometry has started to identify specifically bound lipids presumed to be essential for function. Taken together these molecular snapshots show that nano-scale rotary engines have much in common with basic design principles of man made machines from the function of individual "machine elements" to the requirement of the right "fuel" and "oil" for different types of motors.

  5. Lignite chemical conversion in an indirect heat rotary kiln gasifier

    Directory of Open Access Journals (Sweden)

    Hatzilyberis Kostas S.

    2006-01-01

    Full Text Available The results on the gasification of Greek lignite using two indirect heat (allothermal pilot rotary kiln gasifiers are reported in the present work. The development of this new reactor-gasifier concept intended for solid fuels chemical conversion exploits data and experience gained from the following two pilot plants. The first unit A (about 100 kg/h raw lignite demonstrated the production of a medium heating value gas (12-13 MJ/Nm3 with quite high DAF (dry ash free coal conversions, in an indirect heat rotary gasifier under mild temperature and pressure conditions. The second unit B is a small pilot size unit (about 10 kg/h raw lignite comprises an electrically heated rotary kiln, is an operation flexible and exhibits effective phase mixing and enhanced heat transfer characteristics. Greek lignite pyrolysis and gasification data were produced from experiments performed with pilot plant B and the results are compared with those of a theoretical model. The model assumes a scheme of three consecutive-partly parallel processes (i. e. drying, pyrolysis, and gasification and predicts DAF lignite conversion and gas composition in relatively good agreement with the pertinent experimental data typical of the rotary kiln gasifier performance. Pilot plant B is currently being employed in lime-enhanced gasification studies aiming at the production of hydrogen enriched synthesis gas. Presented herein are two typical gas compositions obtain from lignite gasification runs in the presence or not of lime. .

  6. Solar Alpha Rotary Joint Anomaly: The Materials and Processes Perspective

    Science.gov (United States)

    Basta, Erin A.; Dasgupta, Rijib; Figert, John; Jerman, Greg; Wright, Clara; Petrakis, Dennis; Golden, Johnny L.

    2009-01-01

    This slide presentation reviews the anomaly discovered on the Solar Alpha Rotary Joint (SARJ). This anomaly was discovered when the SARJ mechanism produced anomalous telemetry and noticeable vibrations. Metallic debris was discovered throughout the vicinity of the mechanism. Samples were taken from the SARJ, and the findings of the analysis are discussed.

  7. Rotary Drill Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    Savilow, Bill

    This training outline for rotary drill operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  8. Light-Driven Rotary Molecular Motors on Gold Nanoparticles

    NARCIS (Netherlands)

    Pollard, Michael M.; ter Wiel, Matthijs K. J.; van Delden, Richard A.; Vicario, Javier; Koumura, Nagatoshi; van den Brom, Coenraad R.; Meetsma, Auke; Feringa, Ben L.

    2008-01-01

    We report the synthesis of unidirectional light-driven rotary molecular motors based oil chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of (1)H and (13)C NMR, UV/Vis and CD spectroscopy, we show that these motors

  9. Construction and evaluation of rotary solar dryer for fish drying ...

    African Journals Online (AJOL)

    Rotary solar dryer was developed and evaluated for fish drying. People preferred dried prawns in diet in off seasons. Dried prawns are in high demand in the market and hence Prawns (Kolambi) were selected as drying material. Time required for reducing the moisture content from 75 per cent to final moisture content 16 ...

  10. Experimental results for a novel rotary active magnetic regenerator

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Eriksen, Dan; Bahl, Christian

    2012-01-01

    in a solid refrigerant rather than the temperature change that occurs when a gas is compressed/expanded. This paper presents the general considerations for the design and construction of a high frequency rotary AMR device. Experimental results are presented at various cooling powers for a range of operating...

  11. TRANSIENT SUPPRESSION PACKAGING FOR REDUCED EMISSIONS FROM ROTARY KILN INCINERATORS

    Science.gov (United States)

    Experiments were performed on a 73 kW rotary kiln incinerator simulator to determine whether innovative waste packaging designs might reduce transient emissions of products of incomplete combustion due to batch charging of containerized liquid surrogate waste compounds bound on g...

  12. Apical extrusion of debris using reciprocating files and rotary ...

    African Journals Online (AJOL)

    Background: To compare the preparation time and amount of apically extruded debris after the preparation of root canals in extracted human teeth using the reciprocating files and rotary nickel.titanium systems. Procedure: Sixty extracted human mandibular premolars were used. The root canals were instrumented using ...

  13. Development of Motorized Oil Palm Fruit Rotary Digester | Asoiro ...

    African Journals Online (AJOL)

    A motorized oil palm fruit rotary digester comprising of a feed hopper, hammers, axle, screening plate, v-belt, 2hp electric motor, digesting chamber and frame was designed and developed using standard and locally sourced materials. The performance test analysis showed that its throughput capacity is 117.93kg/hr with a ...

  14. COMPUTER SIMULATION OF DISPERSED MATERIALS MOTION IN ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of computer simulation of dispersed materials motion in rotary furnaces with an inclined axis of rotation. Has been received new data on the dynamic layer work that enhances understanding of heat and mass transfer processes occurring in the layer. 

  15. A reversible, unidirectional molecular rotary motor driven by chemical energy

    NARCIS (Netherlands)

    Fletcher, SP; Dumur, F; Pollard, MM; Feringa, BL

    2005-01-01

    With the long-term goal of producing nanometer-scale machines, we describe here the unidirectional rotary motion of a synthetic molecular structure fueled by chemical conversions. The basis of the rotation is the movement,of a phenyl rotor relative to a naphthyl stator about a single bond axle. The

  16. Evaluation of surface characteristics of rotary nickel‑titanium ...

    African Journals Online (AJOL)

    Background: Instrument fracture is a serious concern in endodontic practice. Objective: The aim of this study was to investigate the surface quality of new and used rotary nickel‑titanium (NiTi) instruments manufactured by the traditional grinding process and twisting methods. Materials and Methods: Total 16 instruments of ...

  17. A rotary ultrasonic motor using bending vibration transducers.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

    2010-10-01

    A rotary ultrasonic motor using bending vibration transducers is proposed. In each transducer, two orthogonal bending vibrations are superimposed and an elliptical trajectory is generated at the driving foot. Typical output of the prototype is a no-load speed of 58 rpm and maximum torque of 9·5 Nm under an exciting voltage of 200 V(rms).

  18. Dynamic behavior of a rotating delaminated composite beam including rotary inertia and shear deformation effects

    Directory of Open Access Journals (Sweden)

    Ramazan-Ali Jafari-Talookolaei

    2015-09-01

    Full Text Available A finite element (FE model is developed to study the free vibration of a rotating laminated composite beam with a single delamination. The rotary inertia and shear deformation effects, as well as the bending–extension, bending–twist and extension–twist coupling terms are taken into account in the FE model. Comparison between the numerical results of the present model and the results published in the literature verifies the validity of the present model. Furthermore, the effects of various parameters, such as delamination size and location, fiber orientation, hub radius, material anisotropy and rotating speed, on the vibration of the beam are studied in detail. These results provide useful information in the study of the free vibration of rotating delaminated composite beams.

  19. Component Energy Efficiencies in a Novel Linear to Rotary Motion Inter-conversion Hydro-mechanism Running a Solar Tracker

    Directory of Open Access Journals (Sweden)

    Kant Eliab Kanyarusoke

    2018-01-01

    Full Text Available A new mechanism interconverting linear and rotary motion was investigated for energy transfers among its components. It employed a gear-rack set, a Hooke coupling and a specially designed bladder-valve system that regulated the motion. The purpose was to estimate individual component mechanical efficiencies as they existed in the prototype so that future reengineering of the mechanism could be properly targeted. Theoretical modelling of the mechanism was first done to obtain equations for efficiencies of the key components. Two-stage experimentation followed when running a solar tracker. The first stage produced data for inputting into the model to determine the efficiencies’ theoretical variation with the Hooke coupling shaft angle. The second one verified results of the Engineering Equation Solver (EES software solutions of the model. It was found that the energy transfer to focus on was that between the Hooke coupling and the output shaft because its efficiency was below 4%

  20. In vitro assessment of cutting efficiency and durability of zirconia removal diamond rotary instruments.

    Science.gov (United States)

    Kim, Joon-Soo; Bae, Ji-Hyeon; Yun, Mi-Jung; Huh, Jung-Bo

    2017-06-01

    Recently, zirconia removal diamond rotary instruments have become commercially available for efficient cutting of zirconia. However, research of cutting efficiency and the cutting characteristics of zirconia removal diamond rotary instruments is limited. The purpose of this in vitro study was to assess and compare the cutting efficiency, durability, and diamond rotary instrument wear pattern of zirconia diamond removal rotary instruments with those of conventional diamond rotary instruments. In addition, the surface characteristics of the cut zirconia were assessed. Block specimens of 3 mol% yttrium cation-doped tetragonal zirconia polycrystal were machined 10 times for 1 minute each using a high-speed handpiece with 6 types of diamond rotary instrument from 2 manufacturers at a constant force of 2 N (n=5). An electronic scale was used to measure the lost weight after each cut in order to evaluate the cutting efficiency. Field emission scanning electron microscopy was used to evaluate diamond rotary instrument wear patterns and machined zirconia block surface characteristics. Data were statistically analyzed using the Kruskal-Wallis test, followed by the Mann-Whitney U test (α=.05). Zirconia removal fine grit diamond rotary instruments showed cutting efficiency that was reduced compared with conventional fine grit diamond rotary instruments. Diamond grit fracture was the most dominant diamond rotary instrument wear pattern in all groups. All machined zirconia surfaces were primarily subjected to plastic deformation, which is evidence of ductile cutting. Zirconia blocks machined with zirconia removal fine grit diamond rotary instruments showed the least incidence of surface flaws. Although zirconia removal diamond rotary instruments did not show improved cutting efficiency compared with conventional diamond rotary instruments, the machined zirconia surface showed smoother furrows of plastic deformation and fewer surface flaws. Copyright © 2016 Editorial Council

  1. Ku Band Rotary Joint Design for SNG Vehicles

    Directory of Open Access Journals (Sweden)

    H. Torpi

    2015-12-01

    Full Text Available A wideband I-type rectangular waveguide rotary joint (RJ is designed, simulated and built. It has an excellent performance over the whole Ku Band (10.7-14.5 GHz where the return loss is less than -23 dB at its highest and the insertion loss is below 0.4 dB. The rotary joint is specifically designed for satellite news gathering (SNG vehicles providing elevation and azimuthal movement to the antenna and matching polarization when it is needed at the feed. It can also be used in other high power microwave applications,where rotation ability of the antenna is a must during the transmission such as radars.

  2. A rotary nano ion pump: a molecular dynamics study.

    Science.gov (United States)

    Lohrasebi, A; Feshanjerdi, M

    2012-09-01

    The dynamics of a rotary nano ion pump, inspired by the F (0) part of the F(0)F(1)-ATP synthase biomolecular motor, were investigated. This nanopump is composed of a rotor, which is constructed of two carbon nanotubes with benzene rings, and a stator, which is made of six graphene sheets. The molecular dynamics (MD) method was used to simulate the dynamics of the ion nanopump. When the rotor of the nanopump rotates mechanically, an ion gradient will be generated between the two sides of the nanopump. It is shown that the ion gradient generated by the nanopump is dependant on parameters such as the rotary frequency of the rotor, temperature and the amounts and locations of the positive and negative charges of the stator part of the nanopump. Also, an electrical potential difference is generated between the two sides of the pump as a result of its operation.

  3. SIMULATION ANALYSIS OF PREHEATER CHARGE TO THE ROTARY FURNACE

    Directory of Open Access Journals (Sweden)

    Jan Mikula

    2015-08-01

    Full Text Available Mathematical modeling of heat aggregates is one of the fundamental methods of the mathematical modelling research. A mathematical model based on the method of elementary balances was created for the thermal treatment of granular and lumpy materials. The adaptation of the selected aggregate model is based on prior knowledge and experiments. The paper presents an adaptation of the mathematical model for the magnesite processing rotary furnace using the mode of caustic and clinker production. A simulation of the charge preheater impact based on the thin layer principle is implemented into the model. The main advantages of using this type of preheater of rotary furnace are smaller dimensions for a large exchange surface and low pressure losses.

  4. Effect of rotational speed in rotary hammer forging process

    Directory of Open Access Journals (Sweden)

    Hamdy Muhammad M

    2015-01-01

    Full Text Available Rotary press forging (RPF has been used in the last century, but it produces many defects in the forgings. The author has invented the rotary hammer forging (RHF process to reduce such defects. RHF is a multi-axes compression process where the material is partially and incrementally deformed by the action of several repeated hammering blows, while the produced deformation region is swept through the whole area of the workpiece. The aim of the present work is to study the effects of rotational speed on the forgings produced by RPF and RHF to compare between the two processes. It has been found that as the rotational speed increases the mushroom effect is constant in RHF while it is greater and increases in RPF. As the rotational speed increases, the twist angle increases in both RHF and RPF, but it is bigger in RPF. These results demonstrate the benefits of using RHF instead of RPF.

  5. The Worringham and Beringer 'visual field' principle for rotary controls.

    Science.gov (United States)

    Hoffmann, Errol R; Chan, Alan H S

    2013-01-01

    Worringham and Beringer (1989, 1998) developed a very important principle relating compatibility of movement of horizontally moving translational controls to display movements when the operator's view of the display is in a plane different to that of the control. On the basis of past data of the current authors, it is shown that the visual field principle also applies to the operation of vertically moving translational controls and to rotary controls. These additions make the Worringham and Beringer principle the most powerful design principle available for situations where the operator is viewing a display that is not in the same plane as the control. High compatibility between control input and display output is of great importance in machine design. This paper demonstrates that, for cases where the display is not in the same plane as the control, the visual field principle is operational for vertically moving translational controls and rotary controls as well as for horizontally moving translational controls.

  6. A Diagnostic System for Speed-Varying Motor Rotary Faults

    Directory of Open Access Journals (Sweden)

    Chwan-Lu Tseng

    2014-01-01

    Full Text Available This study proposed an intelligent rotary fault diagnostic system for motors. A sensorless rotational speed detection method and an improved dynamic structural neural network are used. Moreover, to increase the convergence speed of training, a terminal attractor method and a hybrid discriminant analysis are also adopted. The proposed method can be employed to detect the rotary frequencies of motors with varying speeds and can enhance the discrimination of motor faults. To conduct the experiments, this study used wireless sensor nodes to transmit vibration data and employed MATLAB to write codes for functional modules, including the signal processing, sensorless rotational speed estimation, neural network, and stochastic process control chart. Additionally, Visual Basic software was used to create an integrated human-machine interface. The experimental results regarding the test of equipment faults indicated that the proposed novel diagnostic system can effectively estimate rotational speeds and provide superior ability of motor fault discrimination with fast training convergence.

  7. Torque controlled rotary-shear experiments reveal pseudotachilites formation-dynamics and precursor events

    Science.gov (United States)

    Tisato, Nicola; Cordonnier, Benoit; De Siena, Luca; Lavier, Luc; Di Toro, Giulio

    2017-04-01

    Except few cases, rotary shear tests, which are designed to study dynamic friction and strengthening/weakening mechanisms in seismogenic faults, are performed by imposing, to the specimens, a slipping velocity that is pre-defined. This approach has been adopted from engineering that typically, tests man-made objects that, when functioning, spin or slide at a pre-defined velocity under a pre-defined load. On the other hand, natural earthquakes are the effect of a rupture that nucleates, propagates and arrests in the subsurface. These three phases, and the consequent emerging fault slipping velocity, are controlled by the accumulated and released energy around the seismogenic fault before, during and after the earthquake. Thus, imposing the slipping velocity in laboratory experiments might not represent the best option to uncover many aspects of earthquake nucleation and fault slipping dynamics. Here we present some experiments performed with an innovative rotary shear apparatus that uses a clock-spring that when winded provides to the rotating sample a linearly increasing torque. Thus, the nucleation of simulated events occur spontaneously when the shear stress on the slipping surface overcomes the static friction times the normal load that is controlled by a deadweight. In addition, this method allows studying precursory seismic events resembling natural slow-slip earthquakes. We report some preliminary results for a transparent polymer that has melting point 340 K and allows observing the slipping surface (i.e., the contact between the two samples). By coupling: i) the rotary shear apparatus, ii) a video camera recording at 60 fps and a iii) laser pointer we observed the formation and evolution of a melt film that forms in the slipping surface after a phase of "dry" stick-slip. After each seismic event the melt layer solidify forming a pseudotachilite that partially welds the slipping surfaces. We also present the mechanical data that show rupture strengthening in

  8. Comparison of Two Canal Preparation Techniques Using Mtwo Rotary Instruments

    OpenAIRE

    Hamze, Faeze; Honardar, Kiamars; Nazarimoghadam, Kiumars

    2011-01-01

    INTRODUCTION Root canal preparation is an important process in endodontic therapy. Nickel-titanium (NiTi) rotary file system can be used in single length technique (simultaneous technique) without early coronal enlargement, as well as in crown-down method. The purpose of this in vitro study was to compare single length with crown-down methods’ shaping ability using Mtwo NiTi files. MATERIALS AND METHODS Fifteen acrylic-resin blocks containing simulated canals were divided into two experimenta...

  9. Rotary inverted pendulum: Trajectory tracking via nonlinear control techniques

    Czech Academy of Sciences Publication Activity Database

    Ramos-Velasco, Luis Enrique; Ruiz-León, J. J.; Čelikovský, Sergej

    2002-01-01

    Roč. 38, č. 2 (2002), s. 217-232 ISSN 0023-5954 R&D Projects: GA ČR GA102/02/0709 Grant - others:CONACYT(MX) 31844-A Institutional research plan: CEZ:AV0Z1075907 Keywords : nonlinear systems * rotary inverted pendulum * output regulation * sliding modes Subject RIV: BC - Control Systems Theory Impact factor: 0.341, year: 2002

  10. Piezoelectric Versus Conventional Rotary Techniques for Impacted Third Molar Extraction

    Science.gov (United States)

    Jiang, Qian; Qiu, Yating; Yang, Chi; Yang, Jingyun; Chen, Minjie; Zhang, Zhiyuan

    2015-01-01

    Abstract Impacted third molars are frequently encountered in clinical work. Surgical removal of impacted third molars is often required to prevent clinical symptoms. Traditional rotary cutting instruments are potentially injurious, and piezosurgery, as a new osteotomy technique, has been introduced in oral and maxillofacial surgery. No consistent conclusion has been reached regarding whether this new technique is associated with fewer or less severe postoperative sequelae after third molar extraction. The aim of this study was to compare piezosurgery with rotary osteotomy techniques, with regard to surgery time and the severity of postoperative sequelae, including pain, swelling, and trismus. We conducted a systematic literature search in the Cochrane Library, PubMed, Embase, and Google Scholar. The eligibility criteria of this study included the following: the patients were clearly diagnosed as having impacted mandibular third molars; the patients underwent piezosurgery osteotomy, and in the control group rotary osteotomy techniques, for removing impacted third molars; the outcomes of interest include surgery time, trismus, swelling or pain; the studies are randomized controlled trials. We used random-effects models to calculate the difference in the outcomes, and the corresponding 95% confidence interval. We calculated the weighted mean difference if the trials used the same measurement, and a standardized mean difference if otherwise. A total of seven studies met the eligibility criteria and were included in our analysis. Compared with rotary osteotomy, patients undergoing piezosurgery experienced longer surgery time (mean difference 4.13 minutes, 95% confidence interval 2.75–5.52, P trismus in the piezosurgery groups. The number of included randomized controlled trials and the sample size of each trial were relatively small, double blinding was not possible, and cost analysis was unavailable due to a lack of data. Our meta-analysis indicates that although

  11. A rotary piezoelectric actuator using longitudinal and bending hybrid transducer

    OpenAIRE

    Yingxiang Liu; Xiaohui Yang; Weishan Chen; Junkao Liu

    2012-01-01

    A rotary piezoelectric actuator using bolt-clamped type transducer with double driving feet is proposed in this study. The first-order longitudinal and fourth-order bending vibration modes are superimposed in the actuator to produce elliptical movements on the driving tips. Longitudinal PZT and bending PZT are clamped between the exponential shape horns and the flange by bolts. The vibration shape changes of the actuator are presented to give a clear explanation of its working principle. Seve...

  12. A Review of Heavy-Fueled Rotary Engine Combustion Technologies

    Science.gov (United States)

    2011-05-01

    Engine displacement and CR are determined with these measurements. Shih et al. (63) performed a numerical analysis of the unsteady multidimensional...combustion should be performed together with turbocharging as well as fuel injector and combustion chamber designs and fuel injection strategies. These...Vol. 98. 56. Meng, P. R.; Rice, W. J.; Schock, H. J.; Pringle, D. P. Preliminary Results on Performance Testing of a Turbocharged Rotary

  13. Rotary endodontics in primary teeth – A review

    OpenAIRE

    George, Sageena; Anandaraj, S.; Issac, Jyoti S.; John, Sheen A.; Harris, Anoop

    2015-01-01

    Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti) rotary files have been developed for use in pediatric endod...

  14. Development of a rotary instrumentation system, phase 2

    Science.gov (United States)

    Adler, A.; Skidmore, W.

    1982-01-01

    A rotary instrumentation system which consists of ruggedized miniature telemetry transmitters installed on the rotating shaft of a gas turbine engine to telemeter the outputs of sensors (strain gages, thermocouples, etc.) on rotating engine components was designed. A small prototype system, which demonstrates the capabilities of performing in the intended environment and demonstrates that the system is expandable to handle about 100 data channels was developed.

  15. Design and multi-physics optimization of rotary MRF brakes

    Science.gov (United States)

    Topcu, Okan; Taşcıoğlu, Yiğit; Konukseven, Erhan İlhan

    2018-03-01

    Particle swarm optimization (PSO) is a popular method to solve the optimization problems. However, calculations for each particle will be excessive when the number of particles and complexity of the problem increases. As a result, the execution speed will be too slow to achieve the optimized solution. Thus, this paper proposes an automated design and optimization method for rotary MRF brakes and similar multi-physics problems. A modified PSO algorithm is developed for solving multi-physics engineering optimization problems. The difference between the proposed method and the conventional PSO is to split up the original single population into several subpopulations according to the division of labor. The distribution of tasks and the transfer of information to the next party have been inspired by behaviors of a hunting party. Simulation results show that the proposed modified PSO algorithm can overcome the problem of heavy computational burden of multi-physics problems while improving the accuracy. Wire type, MR fluid type, magnetic core material, and ideal current inputs have been determined by the optimization process. To the best of the authors' knowledge, this multi-physics approach is novel for optimizing rotary MRF brakes and the developed PSO algorithm is capable of solving other multi-physics engineering optimization problems. The proposed method has showed both better performance compared to the conventional PSO and also has provided small, lightweight, high impedance rotary MRF brake designs.

  16. Micro-assembly of three-dimensional rotary MEMS mirrors

    Science.gov (United States)

    Wang, Lidai; Mills, James K.; Cleghorn, William L.

    2009-02-01

    We present a novel approach to construct three-dimensional rotary micro-mirrors, which are fundamental components to build 1×N or N×M optical switching systems. A rotary micro-mirror consists of two microparts: a rotary micro-motor and a micro-mirror. Both of the two microparts are fabricated with PolyMUMPs, a surface micromachining process. A sequential robotic microassembly process is developed to join the two microparts together to construct a threedimensional device. In order to achieve high positioning accuracy and a strong mechanical connection, the micro-mirror is joined to the micro-motor using an adhesive mechanical fastener. The mechanical fastener has self-alignment ability and provides a temporary joint between the two microparts. The adhesive bonding can create a strong permanent connection, which does not require extra supporting plates for the micro-mirror. A hybrid manipulation strategy, which includes pick-and-place and pushing-based manipulations, is utilized to manipulation the micro-mirror. The pick-andplace manipulation has the ability to globally position the micro-mirror in six degrees of freedom. The pushing-based manipulation can achieve high positioning accuracy. This microassembly approach has great flexibility and high accuracy; furthermore, it does not require extra supporting plates, which greatly simplifies the assembly process.

  17. Fatigue behavior of lubricated Ni-Ti endodontic rotary instruments

    Directory of Open Access Journals (Sweden)

    A. Brotzu

    2014-04-01

    Full Text Available The use of Ni-Ti alloys in the practice of endodontic comes from their important properties such as shape memory and superelasticity phenomena, good corrosion resistance and high compatibility with biological tissues. In the last twenty years a great variety of nickel-titanium rotary instruments, with various sections and taper, have been developed and marketed. Although they have many advantages and despite their increasing popularity, a major concern with the use of Ni-Ti rotary instruments is the possibility of unexpected failure in use due to several reasons: novice operator handling, presence manufacturing defects, fatigue etc. Recently, the use of an aqueous gel during experimental tests showed a longer duration of the instruments. The aim of the present work is to contribute to the study of the fracture behavior of these endodontic rotary instruments particularly assessing whether the use of the aqueous lubricant gel can extend their operative life stating its reasons. A finite element model (FEM has been developed to support the experimental results. The results were rather contradictory, also because the Perspex (Poly-methyl methacrylate, PMMA cannot simulate completely the dentin mechanical behavior; however the results highlight some interesting points which are discussed in the paper.

  18. Multi-Fuel Rotary Engine for General Aviation Aircraft

    Science.gov (United States)

    Jones, C.; Ellis, D. R.; Meng, P. R.

    1983-01-01

    Design studies, conducted for NASA, of Advanced Multi-fuel General Aviation and Commuter Aircraft Rotary Stratified Charge Engines are summarized. Conceptual design studies of an advanced engine sized to provide 186/250 shaft KW/HP under cruise conditions at 7620/25,000 m/ft. altitude were performed. Relevant engine development background covering both prior and recent engine test results of the direct injected unthrottled rotary engine technology, including the capability to interchangeably operate on gasoline, diesel fuel, kerosene, or aviation jet fuel, are presented and related to growth predictions. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 30 to 35% fuel economy improvement for the Rotary-engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

  19. Numerical Investigations of an Optimized Airfoil with a Rotary Cylinder

    Science.gov (United States)

    Gada, Komal; Rahai, Hamid

    2015-11-01

    Numerical Investigations of an optimized thin airfoil with a rotary cylinder as a control device for reducing separation and improving lift to drag ratio have been performed. Our previous investigations have used geometrical optimization for development of an optimized airfoil with increased torque for applications in a vertical axis wind turbine. The improved performance was due to contributions of lift to torque at low angles of attack. The current investigations have been focused on using the optimized airfoil for micro-uav applications with an active flow control device, a rotary cylinder, to further control flow separation, especially during wind gust conditions. The airfoil has a chord length of 19.66 cm and a width of 25 cm with 0.254 cm thickness. Previous investigations have shown flow separation at approximately 85% chord length at moderate angles of attack. Thus the rotary cylinder with a 0.254 cm diameter was placed slightly downstream of the location of flow separation. The free stream mean velocity was 10 m/sec. and investigations have been performed at different cylinder's rotations with corresponding tangential velocities higher than, equal to and less than the free stream velocity. Results have shown more than 10% improvement in lift to drag ratio when the tangential velocity is near the free stream mean velocity. Graduate Assistant, Center for Energy and Environmental Research and Services (CEERS), College of Engineering, California State University, Long Beach.

  20. Design analysis of rotary turret of poucher machine

    Directory of Open Access Journals (Sweden)

    Jigar G. Patel

    2016-09-01

    Full Text Available This paper present design analysis of rotary turret plate of 5 kg capacity for food product packaging machine. The turret plate has been designed considering two different criteria, first one is inertia force approach with only self-weight of turret plate and second is with mass of pouches. A 3-dimenssional CAD model of rotary turret assembly has been prepared in using solid modelling packages CRE-O. The finite element analysis (FEA of turret plate has been carried out using analysis software ANSYS 15.0. Consideration of inertia force is one of the criteria to analyze the performance and behaviour of component in working condition. The rotational velocity is applied at the central axis of turret and friction less support is applied on inner surface, where shaft is being attached. Also, pressure is applied on the same surface to incorporate the shrink fit condition of the assembly of turret plate with shaft. The boundary conditions as fixed support have been considered at the different sixteen faces, where bolts have been attached. The obtained simulation results for induced stress, deformation and strain depict that the modified design of rotary turret plate is well within the allowable stress limits of considered material. And, further optimization can be performed for topological and strength based more efficient design of turret plate.

  1. Numerical Analysis on Combustion Characteristic of Leaf Spring Rotary Engine

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2015-08-01

    Full Text Available The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was used to illustrate the structure and principle of the engine. The aims are to (1 improve the understanding of combustion process, and (2 quantify the influence of rotational speed, excess air ratio, initial pressure and temperature on combustion characteristics. The chamber space changed with crankshaft rotation. Due to the complexity of chamber volume, an equivalent modeling method was presented to simulate the chamber space variation. The numerical simulations were performed by solving the incompressible, multiphase Unsteady Reynolds-Averaged Navier–Stokes Equations via the commercial code FLUENT using a transport equation-based combustion model; a realizable  turbulence model and finite-rate/eddy-dissipation model were used to account for the effect of local factors on the combustion characteristics.

  2. Vibration analysis of rotary cement kiln using finite element method

    Directory of Open Access Journals (Sweden)

    Basri Hasan

    2017-01-01

    Full Text Available In this research, the implementation of shell of kiln problem has been discussed. The results are analysed in detail in this research for fatigue life for the shell of a kiln. In this work, the shell of the kiln has been modelled by Solid Works. This simulation showed how the most relevant aspects of the developed work presented in this paper can contribute to the state-of-the-art of the analysis of fatigue life of rotary cement kiln technique with innovative ideas and strategies. It also reviews that the obtained results achieve the proposed objectives. Based on the FEA the transfer matrices and overall transfer equation are developed to calculate natural frequencies, and response overall motion equation is established for response analysis. Due to the dimensionality of the problem addressed, the research specification has to set limits to the applicability of the research by selecting only mechanical load problems in rotary cement kiln tasks and goal-seeking to predict the fatigue life simulation investigated. From the simulation, model and boundary conditions are defined. Crack growth behaviour in the rotary kiln was predicted.

  3. Testing and Development of a Percussive Augmenter for Rotary Drills

    Science.gov (United States)

    Donnelly, Christopher; Bar-Cohen, Yoseph; Chang, Zensheu; Badescu, Mircea; Sherrit, Stewart

    2011-01-01

    Hammering drills are effective in fracturing the drilled medium while rotary drills remove cuttings. The combination provides a highly effective penetration mechanism. Piezoelectric actuators were integrated into an adapter to produce ultrasonic percussion; augmenting rotary drilling. The drill is capable of operating at low power, low applied force and, with proper tuning, low noise. These characteristics are of great interest for future NASA missions and the construction/remodeling industry. The developed augmenter connects a commercially available drill and bit and was tested to demonstrate its capability. Input power to the drill was read using a multimeter and the augmenter received a separate input voltage. The drive frequency of the piezoelectric actuator was controlled by a hill climb algorithm that optimizes and records average power usage to operate the drill at resonating frequency. Testing the rotary drill and augmenter across a range of combinations with total power constant at 160 Watts has shown results in concrete and limestone samples that are as good as or better than the commercial drill. The drill rate was increased 1.5 to over 10 times when compared to rotation alone.

  4. A novel redundant INS based on triple rotary inertial measurement units

    Science.gov (United States)

    Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

    2016-10-01

    Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h-1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h-1, which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required.

  5. 16 CFR 1205.6 - Warning label for reel-type and rotary power mowers.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Warning label for reel-type and rotary power... label for reel-type and rotary power mowers. (a) General. Walk-behind power lawn mowers shall be labeled... size relation to each other and to the label as shown in Fig. 7. EC03OC91.016 (b) Rotary mowers. Walk...

  6. Leaching from waste incineration bottom ashes treated in a rotary kiln

    DEFF Research Database (Denmark)

    Hyks, Jiri; Nesterov, Igor; Mogensen, Erhardt

    2011-01-01

    Leaching from municipal solid waste incineration bottom ash treated in a rotary kiln was quantified using a combination of lab-scale leaching experiments and geochemical modelling. Thermal treatment in the rotary kiln had no significant effect on the leaching of Al, Ba, Ca, Mg, Si, Sr, Zn, sulfate...... the thermal treatment. Overall, rotary kiln thermal treatment of bottom ashes can be recommended to reduce the leaching of Cu, Pb, Cl and DOC; however, increased leaching of Cr and Mo should be expected....

  7. Rotary electrical contact device and method for providing current to and/or from a rotating member

    Science.gov (United States)

    Koplow, Jeffrey P

    2013-11-19

    Examples of rotary electrical connectors include a first pair and a second pair of opposing sheaves coupled together by intersecting first shaft connecting the first pair of opposing sheaves and a second shaft connecting the second pair of opposing sheaves, and at least partially electrically conductive belt disposed about respective perimeters of the first pair and second pair of opposing sheaves and adapted to remain in contact with at least a portion of the respective perimeters of the sheaves during motion of said sheaves. In example devices, one of the plurality of sheaves may remain stationary during operation of the device while the remaining sheaves rotate and/or orbit around a center axis of the stationary sheave, the device being configured to couple current between a stationary power source and a rotating member through the electrically conductive belt.

  8. A comparison of canal preparations by Mtwo and RaCe rotary files using full sequence versus one rotary file techniques; a cone-beam computed tomography analysis

    Directory of Open Access Journals (Sweden)

    Mohsen Aminsobhani

    2014-01-01

    Full Text Available Objectives: Using one rotary file can result in a faster canal preparation. This can be done with several file systems and endodontic motors. In the present study, a newly single file technique (one rotary file technique with available rotary file systems is introduced. The aim of the present study was to evaluate centering ability and remaining dentin thickness of 2 rotary nickel-titanium systems (Mtwo versus RaCe and instrumentation techniques (conventional versus one rotary file by cone-beam computed tomography. Materials and Methods: A total of 76 mandibular molar teeth were selected and divided to 4 groups (n = 19 teeth with 57 canals. The teeth were mounted in resin and pre-instrumentation scans were prepared by Cone Beam Computed Tomography (CBCT. The canals instrumented with Mtwo and RaCe rotary files either in conventional or one rotary file technique (ORF. After cleaning and shaping of distal and mesial canals, post instrumentation scans were performed by CBCT in the same position as pre instrumentation scans. Centering ability and remaining dentin thickness were evaluated by Planmeca Romexis viewer. The data were analyzed with analysis of variance and post hoc t test (P 0.05. However, in a few cross-sections, conventional technique and/or RaCe showed higher centering ability. One rotary file technique with either RaCe or Mtwo was significantly faster than conventional technique (P = 0.02. There was no significant difference among groups regarding file fracture. Mesiolingual canals showed more transportation compared with mesiobuccal and distal canals. Conclusions: Both of the instrumentation systems and techniques produced canal preparations with adequate centering ratio. One rotary file technique prepared canal significantly faster than conventional technique.

  9. Numerical simulation of the influence factors for rotary kiln in temperature field and stress field and the structure optimization

    National Research Council Canada - National Science Library

    Li, Gongfa; Liu, Ze; Jiang, Guozhang; Liu, Honghai; Xiong, Hegen

    2015-01-01

    .... The rotary kiln is one of the most representatives of the furnace equipment; higher requirements of the rotary kiln are put forward in response to the call of the national energy saving and emission reduction...

  10. Nickel-titanium rotary instrument fracture: a clinical practice assessment.

    Science.gov (United States)

    Di Fiore, P M; Genov, K A; Komaroff, E; Li, Y; Lin, L

    2006-09-01

    To prospectively determine the incidence of nickel-titanium rotary instrument fracture in an endodontic clinical practice setting. Eleven second year endodontic residents, using four nickel-titanium rotary instrument systems (ProFile, ProTaper, GTRotary and K3Endo) according to the recommendations of the manufacturers, instrumented 3181 canals in 1403 teeth of 1235 patients, in a dental school post-graduate endodontic clinic, in 1 year. The incidence of instrument fracture was determined based on the number of instruments used. When fracture occurred, data were collected concerning the type, size, taper and prior use of the fractured instruments, the length and location of the fragment within the root canal and the curvature of the canal. The overall incidence of instrument fracture was 0.39%. The incidence of fracture for ProFile, ProTaper, GTRotary and K3Endo files was 0.28%, 0.41%, 0.39% and 0.52%, respectively. There was no statistically significant difference between instrument systems. The percentage of teeth in which instruments fractured was 1.9% (0.28% for anterior teeth, 1.56% for pre-molars and 2.74% for molars). A total of 26 instruments fractured, of which 23 had tapers of 0.06 or greater. Most of the fragments were located in the apical third of the root canal, and both the median and mode amongst the fragment lengths were 2 mm. The low incidence of nickel-titanium rotary instrument fracture supports the continued use of these instruments in root canal treatment.

  11. SIMULATION OF OLIVE PITS PYROLYSIS IN A ROTARY KILN PLANT

    Directory of Open Access Journals (Sweden)

    Giacobbe Braccio

    2011-01-01

    Full Text Available This work deals with the simulation of an olive pits fed rotary kiln pyrolysis plant installed in Southern Italy. The pyrolysis process was simulated by commercial software CHEMCAD. The main component of the plant, the pyrolyzer, was modelled by a Plug Flow Reactor in accordance to the kinetic laws. Products distribution and the temperature profile was calculated along reactor's axis. Simulation results have been found to fit well the experimental data of pyrolysis. Moreover, sensitivity analyses were executed to investigate the effect of biomass moisture on the pyrolysis process.

  12. Performance analysis of a rotary active magnetic refrigerator

    DEFF Research Database (Denmark)

    Lozano, Jaime; Engelbrecht, Kurt; Bahl, Christian R.H.

    2013-01-01

    Performance results for a novel rotary active magnetic regenerator (AMR) and detailed numerical model of it are presented. The experimental device consists of 24 regenerators packed with gadolinium (Gd) spheres rotating inside a four-pole permanent magnet with magnetic field of 1.24T. A parametric......-equivalent cooling power (ExQ), and the overall second law efficiency, η2nd. Losses mapping indicated that friction and thermal leakage to the ambient are the most important contributors to the reduction of the system performance. Based on modeling results, improvements on the flow distributor design and reduction...

  13. Active magnetic regenerator refrigeration with rotary multi-bed technology

    DEFF Research Database (Denmark)

    Eriksen, Dan

    revealed a necessary trade off between the amount of magnetocaloric material and an insulating air gap in the magnetized volume provided by the Halbach-like cylindrical permanent magnet system, when designing for high efficiency rather than maximum cooling power. The central part of the magnet system...... experiments with the new prototype revealed strong impacts on COP and cooling power by minor adjustments of the individual valves controlling the flow in each bed. This effect, inherent to rotary multibed AMRs, is ad- dressed with a numerical modeling approach and confirmed experimentally with the new...

  14. A rotary electromagnetic microgenerator for energy harvesting from human motions

    Directory of Open Access Journals (Sweden)

    Mehdi Niroomand

    2016-08-01

    Full Text Available In this paper, a rotary electromagnetic microgenerator is analyzed, designed and built. This microgenerator can convert human motions to electrical energy. The small size and use of a pendulum mechanism without gear are two main characteristics of the designed microgenerator. The generator can detect small vibrations and produce electrical energy. The performance of this microgenerator is evaluated by being installed peak-to-peak during normal walking. Also, the maximum harvested electrical energy during normal walking is around 416.6 μW. This power is sufficient for many applications.

  15. Rotary Ultrasonic Machining of Poly-Crystalline Cubic Boron Nitride

    Directory of Open Access Journals (Sweden)

    Kuruc Marcel

    2014-12-01

    Full Text Available Poly-crystalline cubic boron nitride (PCBN is one of the hardest material. Generally, so hard materials could not be machined by conventional machining methods. Therefore, for this purpose, advanced machining methods have been designed. Rotary ultrasonic machining (RUM is included among them. RUM is based on abrasive removing mechanism of ultrasonic vibrating diamond particles, which are bonded on active part of rotating tool. It is suitable especially for machining hard and brittle materials (such as glass and ceramics. This contribution investigates this advanced machining method during machining of PCBN.

  16. Pengendalian Modul Rotary Handling Station Bebasis Sequential Function Chart (Sfc)

    OpenAIRE

    Budiantoro, Deli; Halim, Agus; G, Soeharsono

    2014-01-01

    The system used in this day and age has made progress in its operations. In industry itself many use automated systems that only require a small operator to run a tool because it saves time, and safety is guaranteed. In this time the tool discussed Handling Station Rotary pneumatic system uses motion to move this tool. So that the tool can be moved according to plan also required the "brains" to run this tool. Where the brain is a Program Logic Controller (PLC) to save a program that has been...

  17. ROPEC - ROtary PErcussive Coring Drill for Mars Sample Return

    Science.gov (United States)

    Chu, Philip; Spring, Justin; Zacny, Kris

    2014-01-01

    The ROtary Percussive Coring Drill is a light weight, flight-like, five-actuator drilling system prototype designed to acquire core material from rock targets for the purposes of Mars Sample Return. In addition to producing rock cores for sample caching, the ROPEC drill can be integrated with a number of end effectors to perform functions such as rock surface abrasion, dust and debris removal, powder and regolith acquisition, and viewing of potential cores prior to caching. The ROPEC drill and its suite of end effectors have been demonstrated with a five degree of freedom Robotic Arm mounted to a mobility system with a prototype sample cache and bit storage station.

  18. Modeling emulsification processes in rotary-disk mixers

    Science.gov (United States)

    Laponov, S. V.; Shulaev, N. S.; Ivanov, S. P.; Bondar’, K. E.; Suleimanov, D. F.

    2017-10-01

    This article presents the experimental studies results of emulsification processes in liquid-liquid systems in rotary-disk mixers, allowing regulating the distribution of dispersed particles by changing the process conditions and the ratio of the dispersed phase. It is shown that with the increase of mixer’s revolutions per minute (RPM), both the size of dispersed particles and the deviation of dispersed particles sizes from the average decrease. The increase of the dispersed particles part results in the increase of particles average sizes at the current energy consumption. Discovered relationships can be used in the design of industrial equipment and laboratory research.

  19. NASA Subsonic Rotary Wing Project - Structures and Materials Discipline

    Science.gov (United States)

    Halbig, Michael C.; Johnson, Susan M.

    2008-01-01

    The Structures & Materials Discipline within the NASA Subsonic Rotary Wing Project is focused on developing rotorcraft technologies. The technologies being developed are within the task areas of: 5.1.1 Life Prediction Methods for Engine Structures & Components 5.1.2 Erosion Resistant Coatings for Improved Turbine Blade Life 5.2.1 Crashworthiness 5.2.2 Methods for Prediction of Fatigue Damage & Self Healing 5.3.1 Propulsion High Temperature Materials 5.3.2 Lightweight Structures and Noise Integration The presentation will discuss rotorcraft specific technical challenges and needs as well as details of the work being conducted in the six task areas.

  20. 16 CFR 1205.5 - Walk-behind rotary power mower controls.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Walk-behind rotary power mower controls... ACT REGULATIONS SAFETY STANDARD FOR WALK-BEHIND POWER LAWN MOWERS The Standard § 1205.5 Walk-behind rotary power mower controls. (a) Blade control systems—(1) Requirements for blade control. A walk-behind...

  1. 33 CFR 100.914 - Trenton Rotary Roar on the River, Trenton, MI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Trenton Rotary Roar on the River, Trenton, MI. 100.914 Section 100.914 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.914 Trenton Rotary Roar on...

  2. Reversing the direction in a light-driven rotary molecular motor

    NARCIS (Netherlands)

    Ruangsupapichat, Nopporn; Pollard, Michael M.; Harutyunyan, Syuzanna R.; Feringa, Ben L.

    2011-01-01

    Biological rotary motors can alter their mechanical function by changing the direction of rotary motion. Achieving a similar reversal of direction of rotation in artificial molecular motors presents a fundamental stereochemical challenge: how to change from clockwise to anticlockwise motion without

  3. Design and experimental tests of a rotary active magnetic regenerator prototype

    DEFF Research Database (Denmark)

    Eriksen, Dan; Engelbrecht, Kurt; Bahl, Christian

    2015-01-01

    A rotary active magnetic regenerator (AMR) prototype with efficiency and compact design as focus points has been designed and built. The main objective is to demonstrate improved efficiency for rotary devices by reducing heat leaks from the environment and parasitic mechanical work losses while...

  4. Math modeling and computer mechanization for real time simulation of rotary-wing aircraft

    Science.gov (United States)

    Howe, R. M.

    1979-01-01

    Mathematical modeling and computer mechanization for real time simulation of rotary wing aircraft is discussed. Error analysis in the digital simulation of dynamic systems, such as rotary wing aircraft is described. The method for digital simulation of nonlinearities with discontinuities, such as exist in typical flight control systems and rotor blade hinges, is discussed.

  5. 76 FR 62301 - Safety Zone; Rotary Club of Fort Lauderdale New River Raft Race, New River, Fort Lauderdale, FL

    Science.gov (United States)

    2011-10-07

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Rotary Club of Fort Lauderdale New River... Esplanade Park to the Henry Kinney Tunnel, in Fort Lauderdale, Florida during the Rotary Club of Fort... (NPRM) entitled Safety Zone; Rotary Club of Fort Lauderdale New River Raft Race, New River, Fort...

  6. Choice reaction time to visual motion during prolonged rotary motion in airline pilots

    Science.gov (United States)

    Stewart, J. D.; Clark, B.

    1975-01-01

    Thirteen airline pilots were studied to determine the effect of preceding rotary accelerations on the choice reaction time to the horizontal acceleration of a vertical line on a cathode-ray tube. On each trial, one of three levels of rotary and visual acceleration was presented with the rotary stimulus preceding the visual by one of seven periods. The two accelerations were always equal and were presented in the same or opposite directions. The reaction time was found to increase with increases in the time the rotary acceleration preceded the visual acceleration, and to decrease with increased levels of visual and rotary acceleration. The reaction time was found to be shorter when the accelerations were in the same direction than when they were in opposite directions. These results suggest that these findings are a special case of a general effect that the authors have termed 'gyrovisual modulation'.

  7. Influence of oscillating and rotary cutting instruments with electric and turbine handpieces on tooth preparation surfaces.

    Science.gov (United States)

    Geminiani, Alessandro; Abdel-Azim, Tamer; Ercoli, Carlo; Feng, Changyong; Meirelles, Luiz; Massironi, Domenico

    2014-07-01

    Rotary and nonrotary cutting instruments are used to produce specific characteristics on the axial and marginal surfaces of teeth being prepared for fixed restorations. Oscillating instruments have been suggested for tooth preparation, but no comparative surface roughness data are available. To compare the surface roughness of simulated tooth preparations produced by oscillating instruments versus rotary cutting instruments with turbine and electric handpieces. Different grit rotary cutting instruments were used to prepare Macor specimens (n=36) with 2 handpieces. The surface roughness obtained with rotary cutting instruments was compared with that produced by oscillating cutting instruments. The instruments used were as follows: coarse, then fine-grit rotary cutting instruments with a turbine (group CFT) or an electric handpiece (group CFE); coarse, then medium-grit rotary cutting instruments with a turbine (group CMT) or an electric handpiece (group CME); coarse-grit rotary cutting instruments with a turbine handpiece and oscillating instruments at a low-power (group CSL) or high-power setting (group CSH). A custom testing apparatus was used to test all instruments. The average roughness was measured for each specimen with a 3-dimensional optical surface profiler and compared with 1-way ANOVA and the Tukey honestly significant difference post hoc test for multiple comparisons (α=.05). Oscillating cutting instruments produced surface roughness values similar to those produced by similar grit rotary cutting instruments with a turbine handpiece. The electric handpiece produced smoother surfaces than the turbine regardless of rotary cutting instrument grit. Rotary cutting instruments with electric handpieces produced the smoothest surface, whereas the same instruments used with a turbine and oscillating instruments achieved similar surface roughness. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights

  8. ROTARY DAY AT THE UNITED NATIONS OFFICE IN GENEVA

    CERN Multimedia

    Staff Association

    2017-01-01

    We have been informed about the Rotary day at the United Nations office in Geneva. Join us on November 10th & 11th, 2017 at the United Nations office Avenue de la Paix 8-14 1211 Geneva, Switzerland   PEACE: MAKING A DIFFERENCE! Conflict and violence displace millions of people each year. Half of those killed in conflict are children, and 90 percent are civilians. We, Rotarians, refuse conflict as a way of life. But how can we contribute to Peace? And what about you? Are you keen on meeting exceptional individuals and exchanging ideas to move forward? Would you like to network and collaborate with Rotarians, Government Representatives, International Civil Servants, Representatives of Nongovernmental Organizations and Liberal Professions, Businessmen/women, and Students to make a difference in Peace? In November 2017, come to Geneva, get involved, and formulate recommendations to the international community. Together, we’ll celebrate Rotary&a...

  9. A Novel Rotary Piezoelectric Motor Using First Bending Hybrid Transducers

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    2015-08-01

    Full Text Available We report a novel rotary piezoelectric motor using bending transducers in this work. Three transducers are used to drive a disk-shaped rotor together by the elliptical movements of their driving tips; these motions are produced by the hybrid of two first bending vibration modes. The proposed piezoelectric transducer has a simple structure as it only contains an aluminum alloy beam and four pieces of PZT plates. Symmetrical structure is the only necessary condition in the design process as it will ensure the resonance frequencies of the two orthogonal first bending modes are equal. Transducers with first bending resonance frequency of about 53 kHz were fabricated and assembled into a rotary motor. The proposed motor exhibits good performance on speed and torque control. Under a working frequency of 53.2 kHz, the maximum no-load speed and the maximum torque of the prototype are tested to be 53.3 rpm and of 27 mN·m.

  10. Optimal Power Flow Control by Rotary Power Flow Controller

    Directory of Open Access Journals (Sweden)

    KAZEMI, A.

    2011-05-01

    Full Text Available This paper presents a new power flow model for rotary power flow controller (RPFC. RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST and two conventional (series and shunt transformers. Structurally, an RPST consists of two windings (stator and rotor windings. The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.

  11. Micro- and macrostructural characterization of polyvinylpirrolidone rotary-spun fibers.

    Science.gov (United States)

    Sebe, István; Kállai-Szabó, Barnabás; Kovács, Krisztián Norbert; Szabadi, Enikő; Zelkó, Romána

    2015-01-01

    The application of high-speed rotary spinning can offer a useful mean for either preparation of fibrous intermediate for conventional dosage forms or drug delivery systems. Polyvinylpyrrolidone (PVP) and poly(vinylpyrrolidone-vinylacetate) (PVP VA) micro- and nanofibers of different polymer concentrations and solvent ratios were prepared with a high-speed rotary spinning technique. In order to study the influence of parameters that enable successful fiber production from polymeric viscous solutions, a complex micro- and macrostructural screening method was implemented. The obtained fiber mats were subjected to detailed morphological analysis using scanning electron microscope (SEM), and rheological measurements while the microstructural changes of fiber samples, based on the free volume changes, was analyzed by positron annihilation lifetime spectroscopy (PALS) and compared with their mechanical characteristics. The plasticizing effect of water tracked by ortho-positronium lifetime changes in relation to the mechanical properties of fibers. A concentration range of polyvinylpyrrolidone solutions was defined for the preparation of fibers of optimum fiber morphology and mechanical properties. The method enabled fiber formulation of advantageous functionality-related properties for further formulation of solid dosage forms.

  12. Rotary and radial forcing effects on center-of-mass locomotion dynamics.

    Science.gov (United States)

    Shen, Z H; Larson, P L; Seipel, J E

    2014-09-01

    Rotary and radial forcing are two common actuation methods for legged robots. However, these two orthogonal methods of center-of-mass (CoM) forcing have not been compared as potentially alternative strategies of actuation. In this paper, we compare the CoM stability and energetics of running with rotary and radial actuation through the simulation of two models: the rotary-forced spring-loaded inverted pendulum (rotary-forced-SLIP), and the radially-forced-SLIP. We model both radial and rotary actuation in the simplest way, applying them as a constant force during the stance portion of the gait. A simple application of constant rotary forcing throughout stance is capable of producing fully-asymptotically stable motion; however, a similarly constant application of radial forcing throughout the stance is not capable of producing stable solutions. We then allow both the applied rotary and radial forcing functions to turn on or off based on the occurrence of the mid-stance event, which breaks the symmetry of actuation during stance towards a net forward propulsion. We find that both a rotary force applied in the first half of stance and a radial force applied in the second half of stance, are capable of stabilizing running. Interestingly, these two forcing methods improve the motion stability in different ways. Rotary forcing first reduces then greatly increases the size of the stable parameter region when gradually increased. Radial forcing expands the stable parameter region, but only in a moderate way. Also, it is found that parameter region stabilized by rotary and radial forcing are largely complementary. Overall, rotary forcing can better stabilize running for both constant and event-based forcing functions that were attempted. This indicates that rotary forcing has an inherent capability of stabilizing running, even when minimal time-or-event-or-state feedback is present. Radial forcing, however, tends to be more energy efficient when compared to rotary forcing

  13. Modeling of a rotary motor driven by an anisotropic piezoelectric composite laminate.

    Science.gov (United States)

    Zhu, M L; Lee, S R; Zhang, T Y; Tong, P

    2000-01-01

    This paper proposes an analytical model of a rotary motor driven by an anisotropic piezoelectric composite laminate. The driving element of the motor is a three-layer laminated plate. A piezoelectric layer is sandwiched between two anti-symmetric composite laminae. Because of the material anisotropy and the anti-symmetric configuration, torsional vibration can be induced through the inplane strain actuated by the piezoelectric layer. The advantages of the motor are its magnetic field immunity, simple structure, easy maintenance, low cost, and good low-speed performance. In this paper, the motor is considered to be a coupled dynamic system. The analytical model includes the longitudinal and torsional vibrations of the laminate and the rotating motion of the rotor under action of contact forces. The analytical model can predict the overall characteristics of the motor, including the modal frequency and the response of motion of the laminate, the rotating speed of the rotor, the input power, the output power, and the efficiency of the motor. The effects of the initial compressive force, the applied voltage, the moment of rotor inertia, and the frictional coefficient of the contact interface on the characteristics of the motor are simulated and discussed. A selection of the numerical results from the analytical model is confirmed by experimental data.

  14. RMs1: qualification results of the rotary miniature Stirling cryocooler at Thales Cryogenics

    Science.gov (United States)

    Martin, Jean-Yves; Seguineau, Cédric; Van-Acker, Sébastien; Sacau, Mikel; Le Bordays, Julien; Etchanchu, Thierry; Vasse, Christophe; Abadie, Christian; Laplagne, Gilles; Benschop, Tonny

    2017-05-01

    The trend for miniaturized Integrated Dewar and Cooler Assemblies (IDCA) has been confirmed over the past few years with several mentions of a new generation of IR detector working at High Operating Temperature (HOT). This key technology enables the use of cryocooler with reduced needs of cryogenics power. As a consequence, miniaturized IDCA are the combination of a HOT IR detector coupled with a low-size, low-weight and low-power (SWaP) cryocooler. Thales Cryogenics has developed his own line of SWaP products. Qualification results on linear solution where shown last year. The current paper focuses on the latest results obtained on RMs1 prototypes, the new rotary SWaP cryocooler from Thales Cryogenics. Cryogenic performances and induced vibrations are presented. In a second part, progress is discussed on compactness and weight on one side, and on power consumption on the other side. It shows how the trade-off made between weight and power consumption could lead to an optimized solution at system level. At least, an update is made on the qualification status.

  15. Survey of tracking systems and rotary joints for coolant piping. Final report, August 15, 1978-August 14, 1978. [Includes patents

    Energy Technology Data Exchange (ETDEWEB)

    Furaus, J P; Gruchalla, M E; Sower, G D

    1980-01-01

    Problems were surveyed and evaluated with respect to solar tracking mechanisms and rotary joints for coolant piping. An analytical development of celestial mechanics, one- and two-axis tracking configurations and the effect of tracking accuracy versus collector efficiency are reported. Daily operational requirements and tracking modes were defined and evaluated. A literature and patent search on solar tracking technology was performed. Tracking system and control system performance specifications were determined. Alternative conceptual tracking approaches were defined and a cost and performance evaluation of a mechanical tracking concept was performed. Fluid coupling service specifications were determined. The cost and performance of several types of actuators and error detectors were evaluated with respect to solar tracking mechanisms.

  16. Prototype and test of a novel rotary magnetorheological damper based on helical flow

    Science.gov (United States)

    Yu, Jianqiang; Dong, Xiaomin; Wang, Wen

    2016-02-01

    To increase the output damping torque of a rotary magnetorheological (MR) damper with limited geometrical space, a novel rotary MR damper based on helical flow is proposed. A new working mode, helical flow mode, is discussed and applied to enlarge the flow path of MR fluids. The helical flow can improve the performance of the rotary damper by enlarging the length of the active region. Based on the idea, a rotary MR damper is designed. The rotary MR damper contains a spiral piston, dual-coil core, a rotating cylinder and a stator cylinder. Based on the Bingham model, the output damping torque of the damper is analytically derived. The finite element method (FEM) is applied to calculate the magnetic field of the active region. The multi-objective optimal design method is adopted to obtain the optimal geometric parameters. A prototype is fabricated based on the optimal results. To validate the proposed rotary MR damper, two types of experiments including the low rotation speed and the high rotation speed are investigated. The results show that the proposed rotary MR damper has high torque density and compact structure. The helical flow mode can increase the output damping torque with limited space.

  17. A Survey on Nickel Titanium Rotary Instruments and their Usage Techniques by Endodontists in India

    Science.gov (United States)

    Saraf, Prahlad A; Penukonda, Raghavendra; Vanaki, Sneha S; Kamatagi, Laxmikant

    2017-01-01

    Introduction The preference and usage of nickel titanium rotary instruments varies from individual to individual based on their technique, experience with the rotary systems and the clinical situation. Very limited information is available to explain the adoption of changing concepts with respect to nickel titanium rotary instruments pertaining to the endodontists in India. Aim The aim of this study was to conduct a questionnaire survey to acquire the knowledge concerning different NiTi rotary instruments and their usage techniques by endodontists in India. Materials and Methods A Survey questionnaire was designed which consisted of 32 questions regarding designation, demographics, experience with rotary instruments, usage of different file systems, usage techniques, frequency of reuse, occurrence of file fracture, reasons and their management was distributed by hand in the national postgraduate convention and also disseminated via electronic medium to 400 and 600 endodontists respectively. Information was collected from each individual to gain insight into the experiences and beliefs of endodontists concerning the new endodontic technology of rotary NiTi instrumentation based on their clinical experience with the rotary systems. The questions were designed to ascertain the problems, patterns of use and to identify areas of perceived or potential concern regarding the rotary instruments and the data acquired was statistically evaluated using Fisher’s-exact test and the Chi-Square test. Results Overall 63.8% (638) endodontists responded. ProTaper was one of the most commonly used file system followed by M two and ProTaper Next. There was a significant co relation between the years of experience and the file re use frequency, preparation technique, file separation, management of file separation. Conclusion A large number of Endodontists prefer to reuse the rotary NiTi instruments. As there was an increase in the experience, the incidence of file separation reduced

  18. A Survey on Nickel Titanium Rotary Instruments and their Usage Techniques by Endodontists in India.

    Science.gov (United States)

    Patil, Thimmanagowda N; Saraf, Prahlad A; Penukonda, Raghavendra; Vanaki, Sneha S; Kamatagi, Laxmikant

    2017-05-01

    The preference and usage of nickel titanium rotary instruments varies from individual to individual based on their technique, experience with the rotary systems and the clinical situation. Very limited information is available to explain the adoption of changing concepts with respect to nickel titanium rotary instruments pertaining to the endodontists in India. The aim of this study was to conduct a questionnaire survey to acquire the knowledge concerning different NiTi rotary instruments and their usage techniques by endodontists in India. A Survey questionnaire was designed which consisted of 32 questions regarding designation, demographics, experience with rotary instruments, usage of different file systems, usage techniques, frequency of reuse, occurrence of file fracture, reasons and their management was distributed by hand in the national postgraduate convention and also disseminated via electronic medium to 400 and 600 endodontists respectively. Information was collected from each individual to gain insight into the experiences and beliefs of endodontists concerning the new endodontic technology of rotary NiTi instrumentation based on their clinical experience with the rotary systems. The questions were designed to ascertain the problems, patterns of use and to identify areas of perceived or potential concern regarding the rotary instruments and the data acquired was statistically evaluated using Fisher's-exact test and the Chi-Square test. Overall 63.8% (638) endodontists responded. ProTaper was one of the most commonly used file system followed by M two and ProTaper Next. There was a significant co relation between the years of experience and the file re use frequency, preparation technique, file separation, management of file separation. A large number of Endodontists prefer to reuse the rotary NiTi instruments. As there was an increase in the experience, the incidence of file separation reduced with increasing number of re use frequency and with

  19. Experimental determination of pure rotary stability derivatives using curved and rolling flow wind tunnel

    Science.gov (United States)

    Lutze, F. H.

    1980-01-01

    The technique of using a curved and rolling flow wind tunnel to extract pure rotary stability derivatives is presented. Descriptions of the curved flow and the rolling flow test sections of the Virginia Tech Stability Wind Tunnel are given including methods for obtaining the proper velocity profiles and correcting the data acquired. Results of testing current fighter configurations in this facility are presented with particular attention given to comparing pure rotary derivatives with combined rotary and unsteady derivatives obtained by standard oscillation tests. Also the effect of curved and rolling flow on lateral static stability derivatives is examined.

  20. MEMS ultrasonic probe rotary scanning imaging system for medical endoscope

    Science.gov (United States)

    Chen, Xiaodong; Wen, Shijie; Yu, Daoyin

    2006-11-01

    Medical ultrasonic endoscope is the combination of electronic endoscope and ultrasonic sensor technology. Ultrasonic endoscope sends the ultrasonic probe into coelom through the biopsy channel of an electronic endoscope and rotates it by a micro motor, acquiring fault histology features of digestive organs. Compared with external ultrasonic detection, the system reduces the distance between the transducer and the organ, diminishing the effects on imaging of fats and body cavity gas. On the basis of ultrasonic imaging system, this paper implements a pulse echo imaging system. We describe the ultrasonic probe, emission circuit, receiving circuit and protective circuit in detail. With the demodulation circuit, we get the amplitude of echo which indicates the objects. And to achieve the rotary scan, we design a synchronous control circuit and a data transfer circuit basing on the USB2.0 interface. Finally we get a grey image with 256 grey levels after coordinate conversion.

  1. Kinematic Parameters Of Rotary Transmission With Hydraulic Cylinders

    Directory of Open Access Journals (Sweden)

    Blaschuk Mikhail

    2017-01-01

    Full Text Available The issue of designing drives, which provide low frequency (max. 1 rotation per minute rotation with a big moment (min 1 MN m of large technical bodies utilized in restricted spaces, is a complex and contradictory one. The drives of geokhod propeller, rotor actuators of tunneling machines with overload protection, as well as actuators of other machinery meeting aforementioned requirements are examples of such machines. The paper considers mathematical model developed by the authors which determines the relation of design factors of transmission tooled with hydraulic cylinders to kinematic parameters of output element movement. The paper also provides description of methods to determine pumping unit efficiency for rotary transmission tooled with hydraulic cylinders.

  2. A study of particle motion in rotary dryer

    Directory of Open Access Journals (Sweden)

    M. H. Lisboa

    2007-09-01

    Full Text Available The purpose of this work was to study the performance of a rotary dryer in relation to number of flights. In this work an equationing was proposed to calculate the area used by the solids in two-segment flights of with any angle between the segments. From this area, the flight holdup and the length of fall of the particles were calculated for different angle positions and the results obtained were compared to experimental values. The results show an increase in dryer efficiency with the increase in number of flights up to a limit value, for ideal operational conditions. The experimental data on average residence time were compared to results obtained by calculations using equations proposed in the literature. The equation proposed for predicting flight holdup and length of fall of particles generated very accurate estimations.

  3. Combustion of large solid fuels in cement rotary kilns

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma

    The cement industry has a significant interest in replacing fossil fuels with alternative fuels in order to minimize production costs and reduce CO2 emissions. These new alternative fuels are in particular solid fuels such as refuse derived fuel (RDF), tire-derived fuel (TDF), meat and bone meal...... fuels will be mixed into the cement raw materials, which is likely to affect process stability and clinker quality, as described above. The mixing of fuels and raw materials was studied experimentally in a pilot-scale rotary drum and was found to be a fast process, reaching steady state within few drum...... revolutions. Thus, heat transfer by conduction from the cement raw materials to the fuel particles is a major heat transfer mechanism rather than convection or radiation from the freeboard gas above the material bed. Consequently, the temperature of the cement raw materials becomes a factor of great...

  4. Synthetic aggregates from combustion ashes using an innovative rotary kiln.

    Science.gov (United States)

    Wainwright, P J; Cresswell, D J

    2001-01-01

    This paper describes the use of a number of different combustion ashes to manufacture synthetic aggregates using an innovative rotary 'Trefoil' kiln. Three types of combustion ash were used, namely: incinerated sewage sludge ash (ISSA); municipal solid waste incinerator bottom ash (MSWIBA-- referred to here as BA); and pulverised fuel ash (Pfa). The fine waste ash fractions listed above were combined with a binder to create a plastic mix that was capable of being formed into 'green pellets'. These pellets were then fired in a Trefoil kiln to sinter the ashes into hard fused aggregates that were then tested for use as a replacement for the natural coarse aggregate in concrete. Results up to 28 days showed that these synthetic aggregates were capable of producing concretes with compressive strengths ranging from 33 to 51 MPa, equivalent to between 73 and 112% of that of the control concrete made with natural aggregates.

  5. Low torque hydrodynamic lip geometry for rotary seals

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.

    2015-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  6. Rotary Valve & Beamline Highlights for Fiscal Year 2017

    Energy Technology Data Exchange (ETDEWEB)

    Fitsos, P [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-21

    This Fiscal Year (FY) work was divided between continued testing and characterization work of the Rotary Valve (RV) and mechanical engineering support for the beamline hardware stands. This configuration is more like the final setup with the accelerator firing deuterons down the evacuated beamline toward the RV for interaction with the deuterium and neutron production. The beamline cells were part of an experiment to reduce the impact that RV gas would have on the beamline vacuum. This work will be reported separately from this report. Previous testing had been with the beamline at atmospheric pressure and now the goal was to get test results of the RV with it connected to a beamline that’s running at some level of vacuum.

  7. Computational fluid dynamics analysis of sponge iron rotary kiln

    Directory of Open Access Journals (Sweden)

    Gajendra Kumar Gaurav

    2017-03-01

    Full Text Available 2D CFD model of rotary kiln of sponge iron process is developed to study the effects of angle of inclination, number of rotation and mass flow rate of iron ore on output parameters. Based on grid independent test for temperature profile optimum mesh size is selected. The result shows that optimum angle of inclination, number of rotation and flow rate of iron ore are found as 2.7 degree, 4.8 rpm and 10 kg/s, respectively. At these optimum conditions the % metallization is predicted as 89.5%, which is 3.24% less in comparison to the existing system. The temperature profiles of gas and bed are also found within acceptable temperature limits. The results are compared well with the published work as well as industrial data.

  8. Rotary forcespun styrofoam fibers as a soilless growing medium

    Science.gov (United States)

    Fauzi, Ahmad; Edikresnha, Dhewa; Munir, Muhammad Miftahul; Khairurrijal

    2016-04-01

    To make styrofoam fibers from used styrofoam, rotary forcespinning technique was used because it offers high production rate and affordable production cost. The used styrofoam was dissolved in acetone to obtain styrofoam solution as a precursor of syrofoam fibers. Since the technique utilizes centrifugal force, the precursor was thrown out and its phase changed to be solid following acetone solvent evaporation. Long, clean and light styrofoam fibers were then produced. To determine if the styrofoam fibers is a good soilless growing medium, physico-chemical properties including pH and electrical conductivity, bulk density, water retention and wettability were measured. Rockwool, which is the most popular soilless growing medium and easily obtained from local farm suppliers, was selected as a benchmark to evaluate the styrofoam fibers.

  9. Pemodelan dan Simulasi Pengeringan Jagung Pipilan dalam Pengering Rotari Tumpukan

    Directory of Open Access Journals (Sweden)

    Leopold O. Nelwan

    2008-08-01

    Full Text Available A mathematical model of shelled corn drying has been developed in order to simulate the distribution of drying air temperature and humidity as well as the grain moisture content in a rotary bed dryer. The model was based on heat and mass balance of cylindrical packed bed of grain with airflow passing through the bed. Whenever the air relative humidity is higher than the equilibrium moisture content, it is assumed the condensation process will be occurred. Finite difference method with Euler scheme was used to perform the computation. The result showed that the model developed can predict the distribution ofgrain temperature and moisture content. The simulation conducted showed that there would be a wide variation ofmoisture content and temperature if mixing was not applied during the drying process. Mixing was significantly reduced the moisture content variation until a maximum of 0.8% w.b.

  10. Aerodynamic Characteristics of Two Rotary Wing UAV Designs

    Science.gov (United States)

    Jones, Henry E.; Wong, Oliver D.; Noonan, Kevin W.; Reis, Deane G.; Malovrh, Brendon D.

    2006-01-01

    This paper presents the results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of a parametric study of fixed system lift and drag coefficient response to changes in configuration and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect both the character and magnitude of the response. The affect of scaled stores on body drag is observed to be dependent on body shape.

  11. Percussive Augmenter of Rotary Drills (PARoD)

    Science.gov (United States)

    Badescu, Mircea; Hasenoehrl, Jennifer; Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Chang, Zensheu; Ostlund, Patrick; Aldrich, Jack

    2013-01-01

    Increasingly, NASA exploration mission objectives include sample acquisition tasks for in-situ analysis or for potential sample return to Earth. To address the requirements for samplers that could be operated at the conditions of the various bodies in the solar system, a piezoelectric actuated percussive sampling device was developed that requires low preload (as low as 10 N) which is important for operation at low gravity. This device can be made as light as 400 g, can be operated using low average power, and can drill rocks as hard as basalt. Significant improvement of the penetration rate was achieved by augmenting the hammering action by rotation and use of a fluted bit to provide effective cuttings removal. Generally, hammering is effective in fracturing drilled media while rotation of fluted bits is effective in cuttings removal. To benefit from these two actions, a novel configuration of a percussive mechanism was developed to produce an augmenter of rotary drills. The device was called Percussive Augmenter of Rotary Drills (PARoD). A breadboard PARoD was developed with a 6.4 mm (0.25 in) diameter bit and was demonstrated to increase the drilling rate of rotation alone by 1.5 to over 10 times. The test results of this configuration were published in a previous publication. Further, a larger PARoD breadboard with a 50.8 mm (2.0 in) diameter bit was developed and tested. This paper presents the design, analysis and test results of the large diameter bit percussive augmenter.

  12. Ameerika Rotary klubi toetab Maarja küla miljoni krooniga / Kristel Rõss

    Index Scriptorium Estoniae

    Rõss, Kristel, 1967-

    2003-01-01

    Taevaskotta Haavassaarde rajatav Maarja küla oli nädalavahetusel eriliselt rahvarohke, sest puuetega noorte kodu ligi miljoni krooniga toetada lubanud Rotary klubi liikmed Atlantast istutasid Eestimaa mulda tammepuid

  13. Rotary klubi premeeris Politsei- ja Piirivalveameti töötajaid

    Index Scriptorium Estoniae

    2012-01-01

    Tallinna Rotary klubi noorte politseinike ning parima koerajuhi ja teenistuskoera preemia võitnutest: Raili Pärn, Marit Abram, Valur Pajumäe koeraga Golttvizen Hof Dixon, Hendri Lilbok ja Martin Torim

  14. Operating experiences with rotary air-to-air heat exchangers: hospitals, schools, nursing homes, swimming pools

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, R.J.

    1976-01-01

    Systems utilizing rotary air-to-air heat exchangers are discussed. Basic considerations of use (fresh air requirements, system configurations, cost considerations), typical system layout/design considerations, and operating observations by engineers, staff and maintenance personnel are described.

  15. Novel Highly Efficient Compact Rotary-Hammering Planetary Sampler Actuated by a Single Piezoelectric Actuator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We had two objectives in this task: 1. Develop effective single low-mass, low-power piezoelectric drive that can actuate rotary-hammer samplers through walls. 2....

  16. Lightweight Low Force Rotary Percussive Coring Tool for Planetary Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Alliance Spacesystems, LLC produced a rotary percussive drill designed for space use under a NASA-funded Mars Instrument Development Program (MIDP) project ? the...

  17. Clinical Efficiency of Three Caries Removal Systems: Rotary Excavation, Carisolv, and Papacarie.

    Science.gov (United States)

    Hegde, Sapna; Kakti, Ateet; Bolar, Dinesh Rao; Bhaskar, Shubha Arehalli

    2016-01-01

    The removal of dentinal caries using the rotary method of excavation is most often associated with pain and anxiety in children. Chemo-mechanical caries removal may eliminate some of the drawbacks of the rotary technique and improve patient comfort. The purpose of this study was to compare the efficiency of the rotary, Carisolv, and Papacarie methods for caries removal in primary teeth, length of time needed, influence on child behavior, pain perception, and treatment preference of the child. This controlled, split-mouth study with a cross-over design compared three caries removal methods in the primary molars of 50 five- to 12-year-old children. The rotary method was the most efficient and least time-consuming (Pperception, however, was highest with this method (Pcaries removal may be a promising alternative treatment procedure, particularly for anxious young patients.

  18. Kedo-S Paediatric Rotary Files for Root Canal Preparation in Primary Teeth – Case Report

    Science.gov (United States)

    2017-01-01

    Nickel-Titanium (Ni-Ti) instrument are widely used for root canal preparation in permanent tooth compared to primary teeth. Hand instrumentation technique remains the conventional method for root canal preparation in primary teeth. The time taken for root canal preparation with the conventional method is more resulting in patients and clinicians fatigue. Recently Ni-Ti rotary files designed for permanent tooth has been used for root canal preparation in primary teeth. Using rotary instruments for primary tooth pulpectomies resulted in better and predictable root canal filling. This article presents case reports of pulpectomy treatment performed using Kedo-S an exclusive paediatric Ni-Ti rotary files. The advantages and disadvantages in use of Ni-Ti rotary files in primary teeth are discussed in this article. PMID:28511532

  19. Comparison between rotary and manual techniques on duration of instrumentation and obturation times in primary teeth.

    Science.gov (United States)

    Ochoa-Romero, Tania; Mendez-Gonzalez, Veronica; Flores-Reyes, Hector; Pozos-Guillen, Amaury J

    2011-01-01

    The aim of this study was to compare the duration of instrumentation and obturation times and quality of root canal filling between rotary and manual instrumentation techniques in primary teeth. A randomized, controlled clinical trial was performed that included deciduous teeth with pulp necrotic. Forty necrotic teeth were included; 20 were instrumented with a rotary technique (experimental group) and 20 with a manual technique (control group). The time taken for instrumentation and for obturation were recorded in minutes, and the quality of the root canal filling was recorded as optimal, under-filled, or overfilled. The use of the rotary technique diminished the time of instrumentation to 63% and time of obturation to 68%, and it improved the quality of the root canalfilling. The use of rotary instruments in the pulpectomy of primary molars represents a promising technique; the time is significantly reduced.

  20. Rotary and linear molecular motors driven by pulses of a chemical fuel.

    Science.gov (United States)

    Erbas-Cakmak, Sundus; Fielden, Stephen D P; Karaca, Ulvi; Leigh, David A; McTernan, Charlie T; Tetlow, Daniel J; Wilson, Miriam R

    2017-10-20

    Many biomolecular motors catalyze the hydrolysis of chemical fuels, such as adenosine triphosphate, and use the energy released to direct motion through information ratchet mechanisms. Here we describe chemically-driven artificial rotary and linear molecular motors that operate through a fundamentally different type of mechanism. The directional rotation of [2]- and [3]catenane rotary molecular motors and the transport of substrates away from equilibrium by a linear molecular pump are induced by acid-base oscillations. The changes simultaneously switch the binding site affinities and the labilities of barriers on the track, creating an energy ratchet. The linear and rotary molecular motors are driven by aliquots of a chemical fuel, trichloroacetic acid. A single fuel pulse generates 360° unidirectional rotation of up to 87% of crown ethers in a [2]catenane rotary motor. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  1. Mixing large and small particles in a pilot scale rotary kiln

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma; Aniol, Rasmus Wochnik; Larsen, Morten Boberg

    2011-01-01

    The mixing of solid alternative fuel particles in cement raw materials was studied experimentally by visual observation in a pilot scale rotary kiln. Fuel particles were placed on top of the raw material bed prior to the experiment. The percentage of particles visible above the bed as a function...... of time was evaluated with the bed predominantly in the rolling bed mode. Experiments were conducted to investigate the effects of fuel particle size and shape, fuel particle density, rotary kiln fill degree and rotational speed. Large fuel particles and low-density fuel particles appeared more on top.......Results can be up-scaled to industrial conditions in cement rotary kilns and show that even relatively large fuel particles will predominantly be covered by raw material after less than 30s in the rotary kiln. This affects the heating and combustion mechanisms for the fuel particles....

  2. Oscillating Electric Field Measures the Rotation Rate in a Native Rotary Enzyme.

    Science.gov (United States)

    Ferencz, Csilla-Maria; Petrovszki, Pál; Dér, András; Sebők-Nagy, Krisztina; Kóta, Zoltán; Páli, Tibor

    2017-03-27

    Rotary enzymes are complex, highly challenging biomolecular machines whose biochemical working mechanism involves intersubunit rotation. The true intrinsic rate of rotation of any rotary enzyme is not known in a native, unmodified state. Here we use the effect of an oscillating electric (AC) field on the biochemical activity of a rotary enzyme, the vacuolar proton-ATPase (V-ATPase), to directly measure its mean rate of rotation in its native membrane environment, without any genetic, chemical or mechanical modification of the enzyme, for the first time. The results suggest that a transmembrane AC field is able to synchronise the steps of ion-pumping in individual enzymes via a hold-and-release mechanism, which opens up the possibility of biotechnological exploitation. Our approach is likely to work for other transmembrane ion-transporting assemblies, not only rotary enzymes, to determine intrinsic in situ rates of ion pumping.

  3. Kedo-S Paediatric Rotary Files for Root Canal Preparation in Primary Teeth - Case Report.

    Science.gov (United States)

    Jeevanandan, Ganesh

    2017-03-01

    Nickel-Titanium (Ni-Ti) instrument are widely used for root canal preparation in permanent tooth compared to primary teeth. Hand instrumentation technique remains the conventional method for root canal preparation in primary teeth. The time taken for root canal preparation with the conventional method is more resulting in patients and clinicians fatigue. Recently Ni-Ti rotary files designed for permanent tooth has been used for root canal preparation in primary teeth. Using rotary instruments for primary tooth pulpectomies resulted in better and predictable root canal filling. This article presents case reports of pulpectomy treatment performed using Kedo-S an exclusive paediatric Ni-Ti rotary files. The advantages and disadvantages in use of Ni-Ti rotary files in primary teeth are discussed in this article.

  4. Ultrafast dynamics in the power stroke of a molecular rotary motor

    NARCIS (Netherlands)

    Conyard, Jamie; Addison, Kiri; Heisler, Ismael A.; Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Meech, Stephen R.

    Light-driven molecular motors convert light into mechanical energy through excited-state reactions. Unidirectional rotary molecular motors based on chiral overcrowded alkenes operate through consecutive photochemical and thermal steps. The thermal (helix inverting) step has been optimized

  5. Adverse events during rotary-wing transport of mechanically ventilated patients: a retrospective cohort study

    OpenAIRE

    Seymour, Christopher W.; Kahn, Jeremy M.; Schwab, C. William; Fuchs, Barry D.

    2008-01-01

    Introduction Patients triaged to tertiary care centers frequently undergo rotary-wing transport and may be exposed to additional risk for adverse events. The incidence of physiologic adverse events and their predisposing factors in mechanically ventilated patients undergoing aeromedical transport are unknown. Methods We performed a retrospective review of flight records of all interfacility, rotary-wing transports to a tertiary care, university hospital during 2001 to 2003. All patients recei...

  6. MATHEMATICAL MODEL FOR THE STUDY AND DESIGN OF A ROTARY-VANE GAS REFRIGERATION MACHINE

    OpenAIRE

    V.V. Trandafilov; M.G. Khmelniuk; O. Y.Yakovleva

    2016-01-01

    This paper presents a mathematical model of calculating the main parameters the operating cycle, rotary-vane gas refrigerating machine that affect installation, machine control and working processes occurring in it at the specified criteria. A procedure and a graphical method for the rotary-vane gas refrigerating machine (RVGRM) are proposed. A parametric study of the main geometric variables and temperature variables on the thermal behavior of the system is analyzed. The model considers poly...

  7. Kedo-S Paediatric Rotary Files for Root Canal Preparation in Primary Teeth – Case Report

    OpenAIRE

    Jeevanandan, Ganesh

    2017-01-01

    Nickel-Titanium (Ni-Ti) instrument are widely used for root canal preparation in permanent tooth compared to primary teeth. Hand instrumentation technique remains the conventional method for root canal preparation in primary teeth. The time taken for root canal preparation with the conventional method is more resulting in patients and clinicians fatigue. Recently Ni-Ti rotary files designed for permanent tooth has been used for root canal preparation in primary teeth. Using rotary instruments...

  8. Dynamic Modeling and Analysis of the Large-Scale Rotary Machine with Multi-Supporting

    Directory of Open Access Journals (Sweden)

    Xuejun Li

    2011-01-01

    Full Text Available The large-scale rotary machine with multi-supporting, such as rotary kiln and rope laying machine, is the key equipment in the architectural, chemistry, and agriculture industries. The body, rollers, wheels, and bearings constitute a chain multibody system. Axis line deflection is a vital parameter to determine mechanics state of rotary machine, thus body axial vibration needs to be studied for dynamic monitoring and adjusting of rotary machine. By using the Riccati transfer matrix method, the body system of rotary machine is divided into many subsystems composed of three elements, namely, rigid disk, elastic shaft, and linear spring. Multiple wheel-bearing structures are simplified as springs. The transfer matrices of the body system and overall transfer equation are developed, as well as the response overall motion equation. Taken a rotary kiln as an instance, natural frequencies, modal shape, and response vibration with certain exciting axis line deflection are obtained by numerical computing. The body vibration modal curves illustrate the cause of dynamical errors in the common axis line measurement methods. The displacement response can be used for further measurement dynamical error analysis and compensation. The response overall motion equation could be applied to predict the body motion under abnormal mechanics condition, and provide theory guidance for machine failure diagnosis.

  9. Performance improvement of air source heat pump by using gas-injected rotary compressor

    Science.gov (United States)

    Wang, B. L.; Liu, X. R.; Ding, Y. C.; Shi, W. X.

    2017-08-01

    Rotary compressor is most widely used in small capacity refrigeration and heat pump systems. For the air source heat pump, the heating capacity and the COP will be obviously degraded when it is utilized in low temperature ambient. Gas injection is an effective method to enhance its performance under those situations, which has been well applied in air source heat pump with scroll compressor. However, the development of the gas injection technology in rotary compressor is relatively slow due to limited performance improvement. In this research, the essential reason constraining the improvement of the gas injection on the rotary compressor and its heat pump system is identified. Two new injection structures for rotary compressors has been put forward to overcome the drawback of traditional injection structures. Based on a verified numerical model, the thermodynamic performance of air source heat pumps with the new gas-injected rotary compressor are investigated. The results indicate that, compared to the air source heat pump with the traditional gas injected rotary compressor, the new injection structures both can enhance heating capacity and COP of the air source heat pump obviously.

  10. Comparison of two canal preparation techniques using mtwo rotary instruments.

    Science.gov (United States)

    Hamze, Faeze; Honardar, Kiamars; Nazarimoghadam, Kiumars

    2011-01-01

    Root canal preparation is an important process in endodontic therapy. Nickel-titanium (NiTi) rotary file system can be used in single length technique (simultaneous technique) without early coronal enlargement, as well as in crown-down method. The purpose of this in vitro study was to compare single length with crown-down methods' shaping ability using Mtwo NiTi files. Fifteen acrylic-resin blocks containing simulated canals were divided into two experimental groups. In group A, single length technique was used and in group B root canals were prepared by crown-down technique. Pre- and post-preparation canals were photographed in a standardized manner and were superimposed. The inner and outer walls of canal curvature were evaluated at three points (apical, middle and coronal) to determine the greatest change. The data was statistically analyzed using the Student t-test by Statistical Analysis System (SAS) software. Statistical analysis revealed that in group B, dentine was equally removed within the canal coronal to the curvature, whereas in group A, the inner wall was predominantly removed (Plength method and crown-down technique using Mtwo for preparation of apical and middle portion of canal curvature.

  11. Plastic deformation history in infeed rotary swaging process

    Science.gov (United States)

    Liu, Yang; Herrmann, Marius; Schenck, Christian; Kuhfuss, Bernd

    2017-10-01

    In bulk forming processes, the net shape of a final product is achieved by plastic deformation as the material flows from the initial shape to the final shape of the workpiece. The material flow during the process is an important issue for its relationship with forging force, heat generation, microstructure transformation and energy consumption. Hence, the final properties of the product are directly influenced. Former researches showed that the material flow in the rotary swaging process is affected by different processing parameters like die angle, feeding velocity and friction condition. Thus, a profound knowledge of detailed material flow during the process is essential for a better understanding of the process. By using FEM, the material flow was investigated by the history of the plastic strain (PEEQ) development. In this study a 2D-axisymmetric model was built by using ABAQUS explicit. Both aluminum alloy (3.3206) and steel (1.0308) are studied with different feeding velocities and coefficients of friction. To achieve the development of PEEQ in different areas, the workpiece was divided into radial layers. The PEEQ history of each layer was tracked during the quasi-static forming process. Based on that, the plastic strain rate (PSR) was calculated and examined in a single stroke of the process. In that way, the material flow in different layers is presented and the material flow on the surface differs from that in the center, just the first 1/4 radial area from the surface is sensitive to different friction conditions.

  12. Treatment of oily wastes using high-shear rotary ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B.E.; Viadero, R. Jr.; Young, J. [West Virginia Univ., Morgantown, WV (United States). Dept. of Civil and Environmental Engineering; Lin, W. [North Dakota State Univ., Fargo, ND (United States). Dept. of Civil Engineering

    1997-12-01

    The high-shear rotary ultrafiltration (UF) system uses membrane rotation to provide the turbulence required to minimize concentration polarization and flux decline. The high-shear UF system was effective in concentrating oily wastes from about 5% to as high as 65%. The decoupling of turbulence promotion from feed pressurization/recirculation by rotating the membrane was the primary reason for the improvement in performance over that observed with conventional UF systems. Transitional and gel layer oil concentrations (20% and 50--59%, respectively) were higher than values reported in the literature. Permeate flux was dependent on the temperature and rotational speed. Flux increased by about 45% when the temperature was increased from 43 to 60 C. A larger decrease in waste viscosity, over that predicted for water alone, and increased oil droplet diffusivity were hypothesized as reasons for the stronger than expected flux-temperature relationship. The flux-rotational speed ({omega}) relationship was described by J = f({omega}){sup 0.90}; however, the gel layer exhibited stability with increasing {omega}. The ceramic membrane was superior to the polymeric membrane in regards to permeate flux and quality as well as cleaning and durability.

  13. Gas phase dispersion in a small rotary kiln

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B.B.

    1981-07-01

    A study was made of nonideal flow of gas in a rotary kiln reactor. A rotating tube 0.165 m in diameter by 2.17 m long, with internal lifting flights, was operated at room temperature. Rotational speeds from 2.0 to 7.0 rpm, air flow rates from 0.351 to 4.178 m/sup 3//h, and solid contents of 0.0, 5.1, and 15.3% of tube volume were studied. Residence time distribution of the gas was measured by means of the pulse injection technique using a helium tracer. A model was developed based on dispersive flow that exchanges with a deadwater region. Two parameters, a dispersion number describing bulk gas flow and an interchange factor describing exchange between the flow region and the gas trapped in the solids bed, were sufficient to correlate the data, but these parameters are sensitive to experimental error. The model is applicable to analysis of other flow systems, such as packed beds.

  14. A rotary piezoelectric actuator using longitudinal and bending hybrid transducer

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    2012-12-01

    Full Text Available A rotary piezoelectric actuator using bolt-clamped type transducer with double driving feet is proposed in this study. The first-order longitudinal and fourth-order bending vibration modes are superimposed in the actuator to produce elliptical movements on the driving tips. Longitudinal PZT and bending PZT are clamped between the exponential shape horns and the flange by bolts. The vibration shape changes of the actuator are presented to give a clear explanation of its working principle. Several structural parameters of the exponential shape horn are selected and adjusted to accomplish the tuning process of the longitudinal and bending resonance frequencies. The input impedance and vibration characteristics are calculated by using FEM method; the gained results verify the feasibility of the proposed actuator. After the fabrication of a prototype, its vibration characteristics are measured by using a scanning laser Doppler vibrometer; the tested results are in good agreement with the FEM calculated results. The mechanical output performance experiments state that the prototype achieves a maximum speed of 129 r/min and a maximum torque of 1.5 Nm.

  15. A rotary piezoelectric actuator using longitudinal and bending hybrid transducer

    Science.gov (United States)

    Liu, Yingxiang; Yang, Xiaohui; Chen, Weishan; Liu, Junkao

    2012-12-01

    A rotary piezoelectric actuator using bolt-clamped type transducer with double driving feet is proposed in this study. The first-order longitudinal and fourth-order bending vibration modes are superimposed in the actuator to produce elliptical movements on the driving tips. Longitudinal PZT and bending PZT are clamped between the exponential shape horns and the flange by bolts. The vibration shape changes of the actuator are presented to give a clear explanation of its working principle. Several structural parameters of the exponential shape horn are selected and adjusted to accomplish the tuning process of the longitudinal and bending resonance frequencies. The input impedance and vibration characteristics are calculated by using FEM method; the gained results verify the feasibility of the proposed actuator. After the fabrication of a prototype, its vibration characteristics are measured by using a scanning laser Doppler vibrometer; the tested results are in good agreement with the FEM calculated results. The mechanical output performance experiments state that the prototype achieves a maximum speed of 129 r/min and a maximum torque of 1.5 Nm.

  16. High-Resolution Rotational Spectroscopy of a Molecular Rotary Motor

    Science.gov (United States)

    Domingos, Sergio R.; Cnossen, Arjen; Perez, Cristobal; Buma, Wybren Jan; Browne, Wesley R.; Feringa, Ben L.; Schnell, Melanie

    2017-06-01

    To develop synthetic molecular motors and machinery that can mimic their biological counterparts has become a stimulating quest in modern synthetic chemistry. Gas phase studies of these simpler synthetic model systems provide the necessary isolated conditions that facilitate the elucidation of their structural intricacies. We report the first high-resolution rotational study of a synthetic molecular rotary motor based on chiral overcrowded alkenes using chirp-pulsed Fourier transform microwave spectroscopy. Rotational constants and quartic centrifugal distortion constants were determined based on a fit using more than two hundred rotational transitions spanning 5≤J≤21 in the 2-4 GHz frequency range. Despite the lack of polar groups, the rotor's asymmetry produces strong a- and b-type rotational transitions arising from a single predominant conformer. Evidence for fragmentation of the rotor allows for unambiguous identification of the isolated rotor components. The experimental spectroscopic parameters of the rotor are compared and discussed against current high-level ab initio and density functional theory methods. Vicario et al. Chem. Commun., 5910-5912 (2005) Brown et al. Rev. Sci. Instrum., 79, 053103 (2008)

  17. Rotary ultrasonic bone drilling: Improved pullout strength and reduced damage.

    Science.gov (United States)

    Gupta, Vishal; Pandey, Pulak M; Silberschmidt, Vadim V

    2017-03-01

    Bone drilling is one of the most common operations used to repair fractured parts of bones. During a bone drilling process, microcracks are generated on the inner surface of the drilled holes that can detrimentally affect osteosynthesis and healing. This study focuses on the investigation of microcracks and pullout strength of cortical-bone screws in drilled holes. It compares conventional surgical bone drilling (CSBD) with rotary ultrasonic bone drilling (RUBD), a novel approach employing ultrasonic vibration with a diamond-coated hollow tool. Both techniques were used to drill holes in porcine bones in an in-vitro study. Scanning electron microscopy was used to observe microcracks and surface morphology. The results obtained showed a significant decrease in the number and dimensions of microcracks generated on the inner surface of drilled holes with the RUBD process in comparison to CSBD. It was also observed that a higher rotational speed and a lower feed rate resulted in lower damage, i.e. fewer microcracks. Biomechanical axial pullout strength of a cortical bone screw inserted into a hole drilled with RUBD was found to be much higher (55-385%) than that for CSBD. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  18. Reliable suction detection for patients with rotary blood pumps.

    Science.gov (United States)

    Mason, David G; Hilton, Andrew K; Salamonsen, Robert F

    2008-01-01

    All rotary blood pumps (RBPs) are prone to the harmful effects of ventricular collapse or "suction events" because of over-pumping, because they are inherently preload insensitive devices, yet RBP controllers do not comprise a clinically reliable suction detector. We therefore investigated the clinical performance of seven expertly selected time domain indices of suction based on the observed positive spike induced in the RBP impeller speed waveform. Using expert panel classifications, a balanced set of 404 five-second speed snapshots of normal and suction events was created from the impeller speed 25 Hz data in 12 VentrAssist implant patients. Initially, suction index threshold levels were set differently for each patient, giving best sensitivity 95% and specificity 99%. However, analysis of paired combinations of suction indices with fixed thresholds identified one pair giving an acceptable sensitivity of 99.5% and specificity 97.5%; the low number of high speed data samples relative to the speed snapshot mean and maximum OR the largest increase in successive speed maxima. The additional precondition of RBP speed amplitude exceeding a low threshold level allows its more general application to patients with low cardiac contractility. This gives a suction detector with high clinical utility; requiring three index threshold settings only.

  19. Rotary ultrasonic machining of CFRP: A comparison with grinding.

    Science.gov (United States)

    Ning, F D; Cong, W L; Pei, Z J; Treadwell, C

    2016-03-01

    Carbon fiber reinforced plastic (CFRP) composites have been intensively used in various industries due to their superior properties. In aircraft and aerospace industry, a large number of holes are required to be drilled into CFRP components at final stage for aircraft assembling. There are two major types of methods for hole making of CFRP composites in industry, twist drilling and its derived multi-points machining methods, and grinding and its related methods. The first type of methods are commonly used in hole making of CFRP composites. However, in recent years, rotary ultrasonic machining (RUM), a hybrid machining process combining ultrasonic machining and grinding, has also been successfully used in drilling of CFRP composites. It has been shown that RUM is superior to twist drilling in many aspects. However, there are no reported investigations on comparisons between RUM and grinding in drilling of CFRP. In this paper, these two drilling methods are compared in five aspects, including cutting force, torque, surface roughness, hole diameter, and material removal rate. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The development of rotary drum dryer for palm fruit sterilization

    Science.gov (United States)

    Hanifarianty, S.; Legwiriyakul, A.; Alimalbari, A.; Nuntadusit, C.; Theppaya, T.; Wae-Hayee, M.

    2018-01-01

    The aim of this research was to design and develop a rotary drum dryer for palm fruit sterilization. In this article, the results of the effect of ventilation hole number on the reduction of moisture content in palm fruit were presented. The experimental set up was a drum dryer which has 57.5 cm in a diameter and 90 cm in a length (the size was similar to 200-littre steel drum container). A driving gear and a gear motor rotated the drum dryer. The ventilation hole were drilled on the lateral side of the drum. The diameter of ventilation hole was 10 mm, and the number of ventilation hole were 18, 36 and 72 hole (each side was 9, 18 and 36 hole, respectively). In the experiment, the palm fruit was dried by using LPG to burn and heat the bottom of the drum. The flow rate of LPG was controlled to keep the temperature inside the drum steadily at 120°C.

  1. Lightweight Low Force Rotary Percussive Coring Tool for Planetary Applications

    Science.gov (United States)

    Hironaka, Ross; Stanley, Scott

    2010-01-01

    A prototype low-force rotary-percussive rock coring tool for use in acquiring samples for geological surveys in future planetary missions was developed. The coring tool could eventually enable a lightweight robotic system to operate from a relatively small (less than 200 kg) mobile or fixed platform to acquire and cache Mars or other planetary rock samples for eventual return to Earth for analysis. To gain insight needed to design an integrated coring tool, the coring ability of commercially available coring bits was evaluated for effectiveness of varying key parameters: weight-on-bit, rotation speed, percussive rate and force. Trade studies were performed for different methods of breaking a core at its base and for retaining the core in a sleeve to facilitate sample transfer. This led to a custom coring tool design which incorporated coring, core breakage, core retention, and core extraction functions. The coring tool was tested on several types of rock and demonstrated the overall feasibility of this approach for robotic rock sample acquisition.

  2. An Improved Linearization Circuit Used for Optical Rotary Encoders

    Science.gov (United States)

    Jovanović, Jelena; Denić, Dragan; Jovanović, Uglješa

    2017-10-01

    Optical rotary encoders generate nonlinear sine and cosine signals in response to a change of angular position that is being measured. Due to the nonlinear shape of encoder output signals, encoder sensitivity to very small changes of angular position is low, causing a poor measurement accuracy level. To improve the optical encoder sensitivity and to increase its accuracy, an improved linearization circuit based on pseudo-linear signal generation and its further linearization with the two-stage piecewise linear analog-to-digital converter is presented in this paper. The proposed linearization circuit is composed of a mixed-signal circuit, which generates analog pseudo-linear signal and determines the first four bits of the final digital result, and the two-stage piecewise linear analog-to-digital converter, which performs simultaneous linearization and digitalization of the pseudo-linear signal. As a result, the maximal value of the absolute measurement error equals to 3.77168·10-5 [rad] (0.00216°) over the full measurement range of 2π [rad].

  3. Low power consumption mini rotary actuator with SMA wires

    Science.gov (United States)

    Manfredi, Luigi; Huan, Yu; Cuschieri, Alfred

    2017-11-01

    Shape memory alloys (SMAs) are smart materials widely used as actuators for their high power to weight ratio despite their well-known low energy efficiency and limited mechanical bandwidth. For robotic applications, SMAs exhibit limitations due to high power consumption and limited stroke, varying from 4% to 7% of the total length. Hysteresis, during the contraction and extension cycle, requires a complex control algorithm. On the positive side, the small size and low weight are eminently suited for the design of mini actuators for robotic platforms. This paper describes the design and construction of a light weight and low power consuming mini rotary actuator with on-board contact-less position and force sensors. The design is specifically intended to reduce (i) energy consumption, (ii) dimensions of the sensory system, and (iii) provide a simple control without any need for SMA characterisation. The torque produced is controlled by on-board force sensors. Experiments were performed to investigate the energy consumption and performance (step and sinusoidal angle profiles with a frequency varying from 0.5 to 10 Hz and maximal amplitude of {15}\\circ ). We describe a transient capacitor effect related to the SMA wires during the sinusoidal profile when the active SMA wire is powered and the antagonist one switched-off, resulting in a transient current time varying from 300 to 400 ms.

  4. Physics and Histologic Evaluation of Rotary, Ultrasonic, and Sonic Instruments.

    Science.gov (United States)

    Ruga, Emanuele; Amerio, Ettore; Carbone, Vincenzo; Volante, Marco; Gandolfo, Sergio

    2017-10-01

    Rotary instruments (RIs) are the most commonly used to perform osteotomies in many fields of medicine. Owing to a new interest in performing a minimally invasive surgery, over last fifteen years new devices have been used in oral surgery such as ultrasonic instruments (UIs) and, lately, sonic instruments (SIs). Nowadays, bone preservation and regeneration are paramount in many clinical situations and, consequently, it is crucial to rely upon instruments, which cause the least tissue damage during the surgery. Concerning SIs, there is still few information about workload to be applied and related temperature increases; furthermore, there are no comparative in-vivo studies, which analyze the thermal and mechanical effects on bone. Thus, SIs have been compared with UIs and RIs in terms of heat generation, operating time, accuracy, and tissue damage. Decalcification and sectioning procedure resulted in no significant differences between the applied instruments in terms of bone damage. RIs resulted more efficient than UIs (P < 0.001), but demonstrated low accuracy (NRS 4.9), whereas SIs (P = 0.005) required more time to perform the osteotomy. The maximum temperature increase occurred in the ultrasonic group. Even though SI were the slowest, they have proved to be the most accurate (NRS 8.4) in comparison with UI (NRS 7.6) and RI (NRS 4.9). Within the limit of this study, sonic instruments could be considered a safe alternative to ultrasonic instruments.

  5. A novel rotary pulsatile flow pump for cardiopulmonary bypass.

    Science.gov (United States)

    Teman, Nicholas R; Mazur, Daniel E; Toomasian, John; Jahangir, Emilia; Alghanem, Fares; Goudie, Marcus; Rojas-Peña, Alvaro; Haft, Jonathan W

    2014-01-01

    It has been suggested that pulsatile blood flow is superior to continuous flow (CF) in cardiopulmonary bypass (CPB). However, adoption of pulsatile flow (PF) technology has been limited because of practicality and complexity of creating a consistent physiologic pulse. A pediatric pulsatile rotary ventricular pump (PRVP) was designed to address this problem. We evaluated the PRVP in an animal model and determined its ability to generate PF during CPB. The PRVP (modified peristaltic pump, with tapering of the outlet of the pump chamber) was tested in four piglets (10-12 kg). Cannulation was performed with right atrial and aortic cannulae, and pressure sensors were inserted into the femoral arteries. Pressure curves were obtained at different levels of flow and compared with both the animal's baseline physiologic function and a CF roller pump. Pressure and flow waveforms demonstrated significant pulsatility in the PRVP setup compared with CF at all tested conditions. Measurement of hemodynamic energy data, including the percentage pulsatile energy and the surplus hydraulic energy, also revealed a significant increase in pulsatility with the PRVP (p < 0.001). The PRVP creates physiologically significant PF, similar to the pulsatility of a native heart, and has the potential to be easily implemented in pediatric CPB.

  6. Resolving Two Dimensional Angular Velocity within a Rotary Tumbler

    Science.gov (United States)

    Helminiak, Nathaniel; Helminiak, David; Cariapa, Vikram; Borg, John

    2015-11-01

    In this study, a horizontally oriented cylindrical tumbler, filled at variable depth with cylindrical media, was rotated at various constant speeds. A monoplane layer of media was photographed with a high-speed camera and images were post processed with Particle Tracking Velocimetry (PTV) algorithms in order to resolve both the translational and rotational flow fields. Although the translational velocity fields have been well characterized, contemporary resources enabled the ability to expand upon and refine data regarding rotational characteristics of particles within a rotary tumbler. The results indicate that particles rotate according to intermittent no-slip interactions between the particles and solid body rotation. Particles within the bed, not confined to solid body rotation, exhibited behavior indicative of gearing between particles; each reacting to the tangential component of contact forming rotation chains. Furthermore, it was observed that solid body interactions corresponded to areas of confined motion, as areas of high interaction dissuaded no-slip rotation, while areas of developing flow tended towards no-slip rotation. Special thanks to: NASA Wisconsin Space Grant Consortium Program as well as Marquette University OPUS College of Engineering.

  7. Squeeze-Film Air Damping of a Five-Axis Electrostatic Bearing for Rotary Micromotors.

    Science.gov (United States)

    Wang, Shunyue; Han, Fengtian; Sun, Boqian; Li, Haixia

    2017-05-13

    Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeeze-film air damping results of an electrostatic bearing for use in a rotary high-speed micromotor. It is shown that the boundary condition to solve the three-dimensional Reynolds equation, which governs the squeeze-film damping in the air gap between the rotor and its surrounding stator sealed in a three-layer evacuated cavity, behaves with strong cross-axis coupling characteristics. To accurately characterize the damping effect, a set of multiphysics finite-element simulations are performed by computing both the rotor velocity and the distribution of the viscous damping force acting on the rotor. The damping characteristics varying with several key structure parameters are simulated and discussed to optimize the device structure for desirable rotor dynamics. An electrical measurement method is also proposed and applied to validate the numerical results of the damping coefficients experimentally. Given that the frequency response of the electric bearing is critically dependent on the damping coefficients at atmospheric pressure, a solution to the air-film damping measurement problem is presented by taking approximate curve fitting of multi-axis experimental frequency responses. The measured squeeze-film damping coefficients for the five-axis electric bearing agrees well with the numerical solutions. This indicates that numerical multiphysics simulation is an effective method to accurately examine the air-film damping effect for complex device geometry and arbitrary boundary condition. The accurate damping coefficients obtained by FEM simulation will greatly simplify the design

  8. Performance characterization of Watson Ahumada motion detector using random dot rotary motion stimuli.

    Directory of Open Access Journals (Sweden)

    Siddharth Jain

    Full Text Available The performance of Watson & Ahumada's model of human visual motion sensing is compared against human psychophysical performance. The stimulus consists of random dots undergoing rotary motion, displayed in a circular annulus. The model matches psychophysical observer performance with respect to most parameters. It is able to replicate some key psychophysical findings such as invariance of observer performance to dot density in the display, and decrease of observer performance with frame duration of the display.Associated with the concept of rotary motion is the notion of a center about which rotation occurs. One might think that for accurate estimation of rotary motion in the display, this center must be accurately known. A simple vector analysis reveals that this need not be the case. Numerical simulations confirm this result, and may explain the position invariance of MST(d cells. Position invariance is the experimental finding that rotary motion sensitive cells are insensitive to where in their receptive field rotation occurs.When all the dots in the display are randomly drawn from a uniform distribution, illusory rotary motion is perceived. This case was investigated by Rose & Blake previously, who termed the illusory rotary motion the omega effect. Two important experimental findings are reported concerning this effect. First, although the display of random dots evokes perception of rotary motion, the direction of motion perceived does not depend on what dot pattern is shown. Second, the time interval between spontaneous flips in perceived direction is lognormally distributed (mode approximately 2 s. These findings suggest the omega effect fits in the category of a typical bistable illusion, and therefore the processes that give rise to this illusion may be the same processes that underlie much of other bistable phenomenon.

  9. Rotary Balance Wind Tunnel Testing for the FASER Flight Research Aircraft

    Science.gov (United States)

    Denham, Casey; Owens, D. Bruce

    2016-01-01

    Flight dynamics research was conducted to collect and analyze rotary balance wind tunnel test data in order to improve the aerodynamic simulation and modeling of a low-cost small unmanned aircraft called FASER (Free-flying Aircraft for Sub-scale Experimental Research). The impetus for using FASER was to provide risk and cost reduction for flight testing of more expensive aircraft and assist in the improvement of wind tunnel and flight test techniques, and control laws. The FASER research aircraft has the benefit of allowing wind tunnel and flight tests to be conducted on the same model, improving correlation between wind tunnel, flight, and simulation data. Prior wind tunnel tests include a static force and moment test, including power effects, and a roll and yaw damping forced oscillation test. Rotary balance testing allows for the calculation of aircraft rotary derivatives and the prediction of steady-state spins. The rotary balance wind tunnel test was conducted in the NASA Langley Research Center (LaRC) 20-Foot Vertical Spin Tunnel (VST). Rotary balance testing includes runs for a set of given angular rotation rates at a range of angles of attack and sideslip angles in order to fully characterize the aircraft rotary dynamics. Tests were performed at angles of attack from 0 to 50 degrees, sideslip angles of -5 to 10 degrees, and non-dimensional spin rates from -0.5 to 0.5. The effects of pro-spin elevator and rudder deflection and pro- and anti-spin elevator, rudder, and aileron deflection were examined. The data are presented to illustrate the functional dependence of the forces and moments on angle of attack, sideslip angle, and angular rate for the rotary contributions to the forces and moments. Further investigation is necessary to fully characterize the control effectors. The data were also used with a steady state spin prediction tool that did not predict an equilibrium spin mode.

  10. A seat suspension with a rotary magnetorheological damper for heavy duty vehicles

    Science.gov (United States)

    Sun, S. S.; Ning, D. H.; Yang, J.; Du, H.; Zhang, S. W.; Li, W. H.

    2016-10-01

    This paper presents the development of an innovative seat suspension working with a rotary magnetorheological (MR) fluid damper. Compared with a conventional linear MR damper, the well-designed rotary MR damper possesses several advantages such as usage reduction of magnetorheological fluid, low sealing requirements and lower costs. This research starts with the introduction of the seat suspension structure and the damper design, followed by the property test of the seat suspension using an MTS machine. The field-dependent property, amplitude-dependent performance, and the frequency-dependent performance of the new seat suspension are measured and evaluated. This research puts emphasis on the evaluation of the vibration reduction capability of the rotary MR damper by using both simulation and experimental methods. Fuzzy logic is chosen to control the rotary MR damper in real time and two different input signals are considered as vibration excitations. The experimental results show that the rotary MR damper under fuzzy logic control is effective in reducing the vibrations.

  11. Magnetic hardening of Fe{sub 50}Co{sub 50} by rotary swaging

    Energy Technology Data Exchange (ETDEWEB)

    Gröb, T., E-mail: t.groeb@phm.tu-darmstadt.de [Division Physical Metallurgy, Alarich-Weiß-Str. 2, 64287 Darmstadt (Germany); Wießner, L. [Institute for Production Engineering and Forming Machines, Otto-Berndt-Str. 2, 64287 Darmstadt (Germany); Bruder, E. [Division Physical Metallurgy, Alarich-Weiß-Str. 2, 64287 Darmstadt (Germany); Faske, T.; Donner, W. [Divison Structure Research, Alarich-Weiß-Str. 2, 64287 Darmstadt (Germany); Groche, P. [Institute for Production Engineering and Forming Machines, Otto-Berndt-Str. 2, 64287 Darmstadt (Germany); Müller, C. [Division Physical Metallurgy, Alarich-Weiß-Str. 2, 64287 Darmstadt (Germany)

    2017-04-15

    Fe{sub 50}Co{sub 50} was subjected to incremental forming by rotary swaging with the aim of tailoring the coercivity by changing the microstructure. The challenging part of a deformation of Fe{sub 50}Co{sub 50} is an ordering phase present at room temperature, leading to low formability. To increase the formability of the alloy the presence of the ordering phase was supressed by two different concepts. The first concept consists of a heat treatment above the phase transition followed by rapid cooling and deformation at room temperature. The second concept was rotary swaging at temperatures above the phase transition temperature. A comparison in terms of resulting microstructure and magnetic properties shows that both concepts have a potential for tailoring the coercivity of Fe{sub 50}Co{sub 50}. - Highlights: • Magnetic hardening of Fe{sub 50}Co{sub 50} was achieved by rotary swaging with two different concepts. • The influences of the microstructural changes during the rotary swaging process have been linked to magnetic hardening. • Increase in coercivity for Fe{sub 50}Co{sub 50} by rotary swaging at elevated temperature is limited by the dynamic restoration. • Coercivity of Fe{sub 50}Co{sub 50} can be tailored by the induced plastic strain.

  12. Biobased High-Performance Rotary Micromotors for Individually Reconfigurable Micromachine Arrays and Microfluidic Applications.

    Science.gov (United States)

    Kim, Kwanoh; Liang, Zexi; Liu, Minliang; Fan, Donglei Emma

    2017-02-22

    In this work, we report an innovative type of rotary biomicromachines by using diatom frustules as integrated active components, including the assembling, operation, and performance characterization. We further investigate and demonstrate unique applications of the biomicromachines in achieving individually reconfigurable micromachine arrays and microfluidic mixing. Diatom frustules are porous cell walls of diatoms made of silica. We assembled rotary micromachines consisting of diatom frustules serving as rotors and patterned magnets serving as bearings in electric fields. Ordered arrays of micromotors can be integrated and rotated with controlled orientation and a speed up to ∼3000 rpm, one of the highest rotational speeds in biomaterial-based rotary micromachines. Moreover, by exploiting the distinct electromechanical properties of diatom frustules and metallic nanowires, we realized the first reconfigurable rotary micro/nanomachine arrays with controllability in individual motors. Finally, the diatom micromachines are successfully integrated in microfluidic channels and operated as mixers. This work demonstrated the high-performance rotary micromachines by using bioinspired diatom frustules and their applications, which are essential for low-cost bio-microelectromechanical system/nanoelectromechanical system (bio-MEMS/NEMS) devices and relevant to microfluidics.

  13. An experimental study of the putative mechanism of a synthetic autonomous rotary DNA nanomotor.

    Science.gov (United States)

    Dunn, K E; Leake, M C; Wollman, A J M; Trefzer, M A; Johnson, S; Tyrrell, A M

    2017-03-01

    DNA has been used to construct a wide variety of nanoscale molecular devices. Inspiration for such synthetic molecular machines is frequently drawn from protein motors, which are naturally occurring and ubiquitous. However, despite the fact that rotary motors such as ATP synthase and the bacterial flagellar motor play extremely important roles in nature, very few rotary devices have been constructed using DNA. This paper describes an experimental study of the putative mechanism of a rotary DNA nanomotor, which is based on strand displacement, the phenomenon that powers many synthetic linear DNA motors. Unlike other examples of rotary DNA machines, the device described here is designed to be capable of autonomous operation after it is triggered. The experimental results are consistent with operation of the motor as expected, and future work on an enhanced motor design may allow rotation to be observed at the single-molecule level. The rotary motor concept presented here has potential applications in molecular processing, DNA computing, biosensing and photonics.

  14. Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

    Science.gov (United States)

    Kleinheyer, Matthias; Timms, Daniel L; Tansley, Geoffrey D; Nestler, Frank; Greatrex, Nicholas A; Frazier, O Howard; Cohn, William E

    2016-09-01

    Unlike the earlier reciprocating volume displacement-type pumps, rotary blood pumps (RBPs) typically operate at a constant rotational speed and produce continuous outflow. When RBP technology is used in constructing a total artificial heart (TAH), the pressure waveform that the TAH produces is flat, without the rise and fall associated with a normal arterial pulse. Several studies have suggested that pulseless circulation may impair microcirculatory perfusion and the autoregulatory response and may contribute to adverse events such as gastrointestinal bleeding, arteriovenous malformations, and pump thrombosis. It may therefore be beneficial to attempt to reproduce pulsatile output, similar to that generated by the native heart, by rapidly modulating the speed of an RBP impeller. The choice of an appropriate speed profile and control strategy to generate physiologic waveforms while minimizing power consumption and blood trauma becomes a challenge. In this study, pump operation modes with six different speed profiles using the BiVACOR TAH were evaluated in vitro. These modes were compared with respect to: hemodynamic pulsatility, which was quantified as surplus hemodynamic energy (SHE); maximum rate of change of pressure (dP/dt); pulse power index; and motor power consumption as a function of pulse pressure. The results showed that the evaluated variables underwent different trends in response to changes in the speed profile shape. The findings indicated a possible trade-off between SHE levels and flow rate pulsatility related to the relative systolic duration in the speed profile. Furthermore, none of the evaluated measures was sufficient to fully characterize hemodynamic pulsatility. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  15. A Comparative Study of Shaping Ability of four Rotary Systems.

    Science.gov (United States)

    Rubio, Jorge; Zarzosa, José Ignacio; Pallarés, Antonio

    2015-12-01

    This study compared the cutting area, instrumentation time, root canal anatomy preservation and non-instrumented areas obtained by F360(®), Mtwo(®), RaCe(®) and Hyflex(®) files with ISO size 35. 120 teeth with a single straight root and root canal were divided into 4 groups. Working length was calculated by using X-rays. The teeth were sectioned with a handpiece and a diamond disc, and the sections were observed with Nikon SMZ-2T stereoscopic microscope and an Intralux 4000-1 light source. The groups were adjusted with a preoperative analysis with AutoCAD. The teeth were reconstructed by a #10 K-File and epoxy glue. Each group was instrumented with one of the four file systems. The instrumentation time was calculated with a 1/100 second chronometer. The area of the thirds and root canal anatomy preservation were analyzed with AutoCAD 2013 and the non-instrumented areas with AutoCAD 2013 and SMZ-2T stereoscopic microscope. The statistical analysis was made with Levene's Test, ANOVA, Bonferroni Test and Pearson´s Chi-square. Equal variances were shown by Levene's Test (P > 0.05). ANOVA (P > 0.05) showed the absence of significant differences. There were significant differences in the instrumentation time (P 0.05). The 4 different rotary systems produced similar cutting area, root canal anatomy preservation and non-instrumented areas. Regarding instrumentation time, F360(®) was the fastest system statistically.

  16. Modeling shear-induced CHO cell damage in a rotary positive displacement pump.

    Science.gov (United States)

    Kamaraju, Hari; Wetzel, Kenneth; Kelly, William J

    2010-01-01

    Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross-flow filtration. In this research, CHO cells grown in 20-L bioreactors were fed to a rotary lobe pump in both single pass and recycle experiments were conducted at different RPMs and "slip" conditions. The results indicate that the slip flow rate more severely impacts the viability of the CHO cells than the pump RPM. A novel mathematical modeling approach is presented that predicts shear rates in all of the positive displacement pump's slip regions, and then predicts cell death vs. operating conditions. This model accounts for the complex flow situation that results from changes to RPM, backpressure and pump geometry (i.e., clearances). Copyright © 2010 American Institute of Chemical Engineers (AIChE).

  17. TRANSITION PHENOMENON INVESTIGATION BETWEEN DIFFERENT FLOW REGIMES IN A ROTARY DRUM

    Directory of Open Access Journals (Sweden)

    D. A. Santos

    Full Text Available Abstract Rotary drums can show different granular flow regimes each one with its own specific flow behavior, which increase the complexity in their study. The way particles move inside the rotary drum is directly related to the mass and energy transfer rates, and consequently to the process performance. Thus, an experimental investigation regarding the transition between different flow regimes inside a rotary drum was carried out in the present work. To the best of our knowledge, the hysteresis phenomenon was observed for the first time in the transition between cataracting-centrifuging regimes, which was shown to be dependent on the physical properties of the particles such as sphericity, density and particle-wall friction coefficient. A new expression for the centrifuging critical rotation speed was proposed in this work.

  18. Solvent effects on the thermal isomerization of a rotary molecular motor.

    Science.gov (United States)

    Lubbe, Anouk S; Kistemaker, Jos C M; Smits, Esther J; Feringa, Ben L

    2016-09-29

    As molecular machines move to exciting applications in various environments, the study of medium effects becomes increasingly relevant. It is difficult to predict how, for example, the large apolar structure of a light-driven rotary molecular motor is affected by a biological setting or surface proximity, while for future nanotechnology precise fine tuning and full understanding of the isomerization process are of the utmost importance. Previous investigations into solvent effects have mainly focused on the relatively large solvent-solute interaction of hydrogen bonding or polarization induced by the isomerization process. We present a detailed study of a key step in the rotary process i.e. the thermal helix inversion of a completely apolar rotary molecular motor in 50 different solvents and solvent mixtures. Due to the relative inertness of this probe, we are able to study the influence of subtle solvent-solvent interactions upon the rate of rotation. Statistical analysis reveals which solvent parameters govern the isomerization process.

  19. A rotary drum dryer for palm sterilization: preliminary study of flow and heat transfer using CFD

    Science.gov (United States)

    Hanifarianty, S.; Legwiriyakul, A.; Alimalbari, A.; Nuntadusit, C.; Theppaya, T.; Wae-Hayee, M.

    2018-01-01

    Preliminary study in this article, the flow and the heat transfer of rotary drum dryer were simulated by using Computational Fluid Dynamics (CFD). A 3D modelling of rotary drum dryer including ambient air was created by considering transient simulation. The temperature distributions on rotary drum dryer surfaces of experimental setup during heating detected by using infrared camera were given to be boundary conditions of modelling. The average temperature at the surface of the drum lids was 80°C, and the average temperature on the heated surface of the drum was 130°C. The results showed that the internal temperature of air in drum modelling was increased relating on time dependent. The final air temperature inside the drum modelling was similar to the measurement results.

  20. Research on surface temperature compensation of rotary kiln based on inverse exponential model

    Science.gov (United States)

    Dai, Shaosheng; Yu, Liangbing; Zhang, Xiaoxiao; Cheng, Yajun; Chen, Yamei

    2018-01-01

    Aiming at large measurement error of the kiln head in the process of measuring the temperature of the rotary kiln surface, this paper presents a high-precision temperature compensation algorithm for rotary kiln surface based on the inverse exponential model. The algorithm is implemented as follows: First of all, this paper chooses a series of points on the surface of the rotary kiln as monitoring points and calculates the difference between the actual temperature of the monitoring points and the temperature measured by infrared scanning thermometer (IST); Then a relation curve is plotted between the temperature differences and measuring distances; Finally the nonlinear model of inverse exponential function is established according to the curve trend. The experimental results show that the algorithm can obviously reduce the error of temperature measurement, and compared to the traditional method, the proposed method reduces the error of temperature measurement from 1.26% to 0.14%.

  1. Scanning electron microscopy comparison of the cleaning efficacy of a root canal system by Nd:YAG laser and rotary instruments.

    Science.gov (United States)

    Samiei, Mohammad; Pakdel, Seyyed Mahdi Vahid; Rikhtegaran, Sahand; Shakoei, Sahar; Ebrahimpour, Delaram; Taghavi, Pedram

    2014-08-01

    This study evaluated the cleaning efficacy of a root canal system by Nd:YAG laser and rotary instruments. Sixty single-rooted human teeth were divided into four experimental groups (n=15). In the first group the teeth were prepared with a step-back technique using conventional K-files. In the second and third groups, tooth preparation was carried out using Nd:YAG laser and rotary NiTi instruments, respectively. Teeth in the fourth group were prepared by combined laser and rotary methods. The smear layer remaining on canal walls was then assessed by scanning electron microscopy in the coronal, middle, and apical portions. The comparison of smear layer removal efficacy between groups was carried out by Kruskal-Wallis and Mann-Whitney U tests. The mean grades of smear layer removal in rotary-laser, rotary, laser and step-back techniques were 1.34 ± 0.18, 2.2 ± 0.28, 1.91 ± 0.25, and 2.42 ± 0.19, respectively. On the whole, differences between rotary-laser and rotary groups, step-back, and the three other techniques (rotary, laser, and rotary-laser) were significant at p=0.034. Based on the findings of this study, the cleaning efficacy of rotary, laser, and rotary-laser techniques were better than the step-back technique and the combined laser and rotary technique was the most efficient method.

  2. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    2015-01-01

    We study possible motivations for co-entreprenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes...... with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse – most commonly the female – has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female...

  3. Accidental separation and lodgment of rotary endodontic file into the dentist's thumb.

    Science.gov (United States)

    Karnik, Rohit; Shetty, Subraj; Desai, Rajiv S; Shetty, Karthick

    2016-01-01

    Separation of the endodontic instrument within the root canal system and sharp injuries to the dentist is not an uncommon event in endodontic practice. Although root canal instruments can fracture at any stage of endodontic treatment, its fracture within the dentist's hand is a very rare event. An unusual case of accidental separation and lodgment of rotary endodontic file in the dentist's thumb is presented along with its management. A 33-year-old dentist reported with an accidental lodgment of rotary endodontic file into his thumb. The fractured instrument was removed successfully by a surgeon. The present case describes a rare event of occupational risk in endodontic practice.

  4. Nonlinear Motion Control of a Rotary Wing Vehicle Powered by Four Rotors

    Directory of Open Access Journals (Sweden)

    S. Araujo–Estrada

    2009-10-01

    Full Text Available This paper presents a solution to the motion control problem for a rotary wing vehicle powered by four rotors. It is considered that the rotary wing vehicle performs an indoor low speed flight mission so that aerodynamic effects are not taken into account. The proposed controller is based on a combination of the well–known backstepping nonlinear control design technique and bounded controllers. It is shown that the resulting closed—loop dynamics evolves inside a set where singularities are avoided. Numerical simulations show the performance of the proposed controller.

  5. Choice-reaction time to visual motion with varied levels of simultaneous rotary motion

    Science.gov (United States)

    Clark, B.; Stewart, J. D.

    1974-01-01

    Twelve airline pilots were studied to determine the effects of whole-body rotation on choice-reaction time to the horizontal motion of a line on a cathode-ray tube. On each trial, one of five levels of visual acceleration and five corresponding proportions of rotary acceleration were presented simultaneously. Reaction time to the visual motion decreased with increasing levels of visual motion and increased with increasing proportions of rotary acceleration. The results conflict with general theories of facilitation during double stimulation but are consistent with neural-clock model of sensory interaction in choice-reaction time.

  6. 3D finite elements method (FEM Analysis of basic process parameters in rotary piercing mill

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2012-10-01

    Full Text Available In this paper 3D FEM analysis of process parameters and its infl uence in rotary piercing mill is presented. The FEM analyze of the rotary piercing process was made under the conditions of 3D state of strain with taking into consideration the thermal phenomena. The calculations were made with application of different rolls’ skew angles and different plug designs. In the result, progression of shapes, temperature and distributions of stress and strain were characterized. The numerical results of calculations were compared with results of stand test with use of 100Cr6 steel. The comparisons of numerical and experimental tests confirm good agreement between obtained results.

  7. Carbon Fiber Reinforced Carbon Composites Rotary Valves for Internal Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    Carbon fiber reinforced carbon composite rotary, sleeve, and disc valves for internal combustion engines and the like are disclosed. The valves are formed from knitted or braided or warp-locked carbon fiber shapes. Also disclosed are valves fabricated from woven carbon fibers and from molded carbon matrix material. The valves of the present invention with their very low coefficient of thermal expansion and excellent thermal and self-lubrication properties, do not present the sealing and lubrication problems that have prevented rotary, sleeve, and disc valves from operating efficiently and reliably in the past. Also disclosed are a sealing tang to further improve sealing capabilities and anti-oxidation treatments.

  8. Carbon Fiber Reinforced Carbon Composite Rotary Valve for an Internal Combustion Engine

    Science.gov (United States)

    Northam, G.Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    2000-01-01

    Carbon fiber reinforced carbon composite rotary sleeve, and disc valves for internal combustion engines and the like are disclosed. The valves are formed from knitted or braided or wrap-locked carbon fiber shapes. Also disclosed are valves fabricated from woven carbon fibers and from molded carbon matrix material. The valves of the present invention with their very low coefficient of thermal expansion and excellent thermal and self-lubrication properties do not present the sealing and lubrication problems that have prevented rotary sleeve and disc valves from operating efficiently and reliably in the past. Also disclosed are a sealing tang to further improve sealing capabilities and anti-oxidation treatments.

  9. SO2 Release as a Consequence of Alternative Fuel Combustion in Cement Rotary Kiln Inlets

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter

    2015-01-01

    The combustion of alternative fuels in direct contact with the bed material of the rotary kiln may cause local reducing conditions and, subsequently, decomposition of sulfates from cement raw materials, increasing the SO2 concentration in the gas phase. The decomposition of sulfates increases......-temperature rotary drum, focusing on the influence of the fuel particle size and volatile content. The SO2 release increased with a decreasing fuel particle size and with an increasing fuel volatile content. Furthermore, CO, H2, and CH4, which are the main reducing gases released during fuel devolatilization, were...

  10. Long-term Impact of Rotary Method of Soil Mechanical Treatment on Soil Properties

    Directory of Open Access Journals (Sweden)

    Valeriy P. Kalinichenko

    2012-10-01

    Full Text Available The imitating approach to the technique and technology of soil cultivation excels the influence of natural factors of soil formation and leads to the anthropogenic biosphere degradation. The article fundamentally justifies the rotary soil cultivation in terms of genesis of soil. This method provides the formation of a new layer in the soil depth, which intensifies the geological and biological processes, influences the overlying soil layers, increases the biological productivity of the soil and stability of its mechanical system for a long term. Technical solutions of rotary devices for soil cultivation are considered and long-term results of their practical application are presented.

  11. Wear-Reducing Technologies for Rotary Compressors Using CO2 Refrigerant

    Science.gov (United States)

    Nakao, Hideto; Maeyama, Hideaki; Hattori, Naotaka; Takayama, Tomoo

    We have developed a CO2 heat pump water heater compressor with a single-stage rotary mechanism for the first time in the world. Because the rotary compressor has a simple mechanism, it has become the mainstream for air conditioning compressors using R410A. The two-stage rotary and scroll compressors using CO2 have been put into practical use, however the single-stage rotary compressor had not been put to practical use, because the operating pressure of CO2 is more than three times as high as R410A refrigerants. We have applied a processing the DLC-Si (diamond-like-carbon-silicon) to the vane. It is the film of the DLC containing the silicon with a method of the plasma C.V.D. (chemical vapor deposit). The DLC-Si coated vane is hardly worn-out, only the surface roughness is smoothed. This paper describes the relationship between the silicon concentration in the DLC-Si film and their characteristics. Especially the adhesion strength is secured and the internal fracture is prevented by optimizing of the silicon concentration. In applying DLC-Si for practical use of the vane, we controlled the silicon concentration and secured high adhesion strength of the film. We were able to achieve an excellent level of wear durability.

  12. A Method For Producing Hollow Shafts By Rotary Compression Using A Specially Designed Forging Machine

    Directory of Open Access Journals (Sweden)

    Tomczak J.

    2015-09-01

    Full Text Available The paper presents a new method for manufacturing hollow shafts, where tubes are used as billet. First, the design of a specially designed forging machine for rotary compression is described. The machine is then numerically tested with regard to its strength, and the effect of elastic strains of the roll system on the quality of produced parts is determined. The machine’s strength is calculated by the finite element method using the NX Nastran program. Technological capabilities of the machine are determined, too. Next, the results of the modeling of the rotary compression process for a hollow stepped shafts by the finite element method are given. The process for manufacturing hollow shafts was modeled using the Simufact.Forming simulation program. The FEM results are then verified experimentally in the designed forging machine for rotary compression. The experimental results confirm that axisymmetric hollow shafts can be produced by the rotary compression method. It is also confirmed that numerical methods are suitable for investigating both machine design and metal forming processes.

  13. Analysis of kinematic, kinetic and electromyographic patterns during root canal preparation with rotary and manual instruments

    Directory of Open Access Journals (Sweden)

    Braulio Pasternak-Júnior

    2012-02-01

    Full Text Available OBJECTIVE: This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG. MATERIAL AND METHODS: The operators prepared one canal with RaCe rotary instruments and another with Flexo-files. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radialis, extensor carpi radialis, brachioradialis, biceps brachii, triceps brachii, middle deltoid, and upper trapezius were recorded. The joint torques of the shoulder, elbow and wrist were calculated using inverse dynamics. In the kinematic analysis, angular movements of the wrist and elbow were classified as low risk factors for work-related musculoskeletal disorders. With respect to the shoulder, the classification was medium-risk. RESULTS: There was no significant difference revealed by the kinetic reports. The EMG results showed that for the middle deltoid and upper trapezius the rotary instrumentation elicited higher values. The flexor carpi radialis and extensor carpi radialis, as well as the brachioradialis showed a higher value with the manual method. CONCLUSION: The muscular recruitment for accomplishment of articular movements for root canal preparation with either the rotary or manual techniques is distinct. Nevertheless, the rotary instrument presented less difficulty in the generation of the joint torque in each articulation, thus, presenting a greater uniformity of joint torques.

  14. Torsional Properties of Proprietary Heat Treated Nickel Titanium Rotary Instruments versus Conventional Nickel Titanium

    Science.gov (United States)

    2016-06-30

    rotational degrees (o) at separation were measured with a custom-built torsiometer instrument (Sabri Dental Enterprises, Inc, Downers Grove, IL) in...Torsional Properties of Proprietary Heat-Treated Nickel-Titanium Rotary Instruments versus Conventional Nickel-Titanium Principle Author...investigations at the USAF Dental Evaluation & Consultation Services (DECS) Laboratory. Responsible for calculating and analyzing all data collected during

  15. Miniaturized Rotary Actuators Using Shape Memory Alloy for Insect-Type MEMS Microrobot

    Directory of Open Access Journals (Sweden)

    Ken Saito

    2016-03-01

    Full Text Available Although several types of locomotive microrobots have been developed, most of them have difficulty locomoting on uneven surfaces. Thus, we have been focused on microrobots that can locomote using step patterns. We are studying insect-type microrobot systems. The locomotion of the microrobot is generated by rotational movements of the shape memory alloy-type rotary actuator. In addition, we have constructed artificial neural networks by using analog integrated circuit (IC technology. The artificial neural networks can output the driving waveform without using software programs. The shape memory alloy-type rotary actuator and the artificial neural networks are constructed with silicon wafers; they can be integrated by using micro-electromechanical system (MEMS technology. As a result, the MEMS microrobot system can locomote using step patterns. The insect-type MEMS microrobot system is 0.079 g in weight and less than 5.0 mm in size, and its locomotion speed is 2 mm/min. The locomotion speed is slow because the heat of the shape memory alloy conducts to the mechanical parts of the MEMS microrobot. In this paper, we discuss a new rotary actuator compared with the previous model and show the continuous rotation of the proposed rotary actuator.

  16. A combined infrared/heat pump drying technology applied to a rotary dryer

    National Research Council Canada - National Science Library

    K. PÄÄKKÖNEN

    2008-01-01

    .... The purpose of this work was to develop a small-scale dryer for herbs and vegetables. A prototype rotary dryer combining infrared radiation with a so-called heat pump drying method was applied in drying experiments for several herbs and vegetables...

  17. A reduced fidelity model for the rotary chemical looping combustion reactor

    KAUST Repository

    Iloeje, Chukwunwike O.

    2017-01-11

    The rotary chemical looping combustion reactor has great potential for efficient integration with CO capture-enabled energy conversion systems. In earlier studies, we described a one-dimensional rotary reactor model, and used it to demonstrate the feasibility of continuous reactor operation. Though this detailed model provides a high resolution representation of the rotary reactor performance, it is too computationally expensive for studies that require multiple model evaluations. Specifically, it is not ideal for system-level studies where the reactor is a single component in an energy conversion system. In this study, we present a reduced fidelity model (RFM) of the rotary reactor that reduces computational cost and determines an optimal combination of variables that satisfy reactor design requirements. Simulation results for copper, nickel and iron-based oxygen carriers show a four-order of magnitude reduction in simulation time, and reasonable prediction accuracy. Deviations from the detailed reference model predictions range from 3% to 20%, depending on oxygen carrier type and operating conditions. This study also demonstrates how the reduced model can be modified to deal with both optimization and design oriented problems. A parametric study using the reduced model is then applied to analyze the sensitivity of the optimal reactor design to changes in selected operating and kinetic parameters. These studies show that temperature and activation energy have a greater impact on optimal geometry than parameters like pressure or feed fuel fraction for the selected oxygen carrier materials.

  18. Design and implementation of a novel rotary micropositioning system driven by linear voice coil motor

    Science.gov (United States)

    Xu, Qingsong

    2013-05-01

    Limited-angle rotary micropositioning stages are required in precision engineering applications where an ultrahigh-precision rotational motion within a restricted range is needed. This paper presents the design, fabrication, and control of a compliant rotary micropositioning stage dedicated to the said applications. To tackle the challenge of achieving both a large rotational range and a compact size, a new idea of multi-stage compound radial flexure is proposed. A compact rotary stage is devised to deliver an over 10° rotational range while possessing a negligible magnitude of center shift. The stage is driven by a linear voice coil motor and its output motion is measured by laser displacement sensors. Analytical models are derived to facilitate the parametric design, which is validated by conducting finite element analysis. The actuation and sensing issues are addressed to guarantee the stage performance. A prototype is fabricated and a proportional-integral-derivative control is implemented to achieve a precise positioning. Experimental results demonstrate a resolution of 2 μrad over 10° rotational range as well as a low level of center shift of the rotary micropositioning system.

  19. Apical extrusion of Enterococcus faecalis using three different rotary instrumentation techniques: an in vitro study.

    Science.gov (United States)

    Taneja, Sonali; Kumari, Manju; Barua, Madhumita; Dudeja, Chetna; Malik, Meeta

    2015-01-01

    To compare the apical extrusion of Enterococcus faecalis after instrumentation with three different Ni-Ti rotary instruments- An in vitro study. In vitro study Methods and Material: Forty freshly extracted mandibular premolars were mounted in bacteria collection apparatus and root canals were contaminated with a suspension of Enterococcus faecalis. The contaminated teeth were divided into 4 groups of 10 teeth each according to rotary system used for instrumentation: Group1: Hyflex files, Group 2: GTX files, Group 3: Protaper files and Group 4: control group (no instrumentation). Bacteria extruded after preparations were collected into vials and microbiological samples were incubated in BHI broth for 24 hrs. The colony forming units were determined for each sample. Statistical analysis was done using one way ANOVA followed by post hoc independent " t" test. GTX files extruded least amount of bacteria followed by Hyflex files. Maximum extrusion of E. faecalis was seen in rotary Protaper group. Least amount of extrusion was seen with GTX files followed by Hyflex files and then rotary Protaper system.

  20. Comparison of two contemporary rotary systems in a pre-clinical student course setting.

    Science.gov (United States)

    Marending, M; Biel, P; Attin, T; Zehnder, M

    2016-06-01

    To assess two contemporary rotary instrumenting systems subjectively and objectively in a pre-clinical student course setting. Undergraduate dental students (n = 44) prepared mesiolingual canals of 3D-printed mandibular molar replicas (RepliDens, Zurich, Switzerland). The HyFlex and BioRace rotary systems, both previously unknown to the students, were used according to the manufacturers' guidelines after a short theoretical introduction. For comparison, a first-generation rotary system (ProFile .04), which the students knew from their previous education, was then used in a third RepliDens. Questionnaires were issued to note subjective experiences immediately after instrumentation. Objectively, time to instrument to size 40, .04 taper and shaping outcomes were analysed. Categorical data were compared using chi-square and Fisher's exact tests, numerical data according to goodness of fit to the normal distribution, P HyFlex counterpart, whilst they found better controllability with the HyFlex (P HyFlex (and the ProFile) systems compared to BioRace (P HyFlex and BioRace had perceived and quantifiable strengths and weaknesses. Both systems were equally liked by the students and preferred over the ProFile first-generation rotary system. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  1. Modal analysis and modeling of a frictionless electrostatic rotary stepper micromotor

    NARCIS (Netherlands)

    Stranczl, M.; Sarajlic, Edin; Krijnen, Gijsbertus J.M.; Fujita, H.; Gijs, M.A.M.; Yamahata, C.

    2011-01-01

    We present the design, modeling and characterization of a 3-phase electrostatic rotary stepper micromotor. The proposed motor is a monolithic device fabricated using silicon-on-insulator (SOI) technology. The rotor is suspended with a frictionless flexural pivot bearing and reaches an unprecedented

  2. Effect of Particle Size Distribution on Ammonium Sulphate Dried in a Rotary Dryer

    Directory of Open Access Journals (Sweden)

    Susianto Susianto

    2010-08-01

    Full Text Available The aim of this work is to study theoretically, by mathematical model development, the effect of particle size distribution on the performance of rotary dryer to dry ammonium sulphate fertilizer assuming plug flow with axial dispersion pattern (PFDA model for solid particle flow. The mathematical model development was carried out by combining the drying processes model with particle size distribution model. Particle size distribution models used are Rosin-Rommler model and Gamma distribution model. For simplicity, the model of drying processes of solid particles in the rotary dryer was developed by assuming of uniform air conditions (temperature and humidity along the rotary dryer as in the entry conditions. The resulting differential equations were solved analytically under Matlab 6.1 facility.Since this model, solid hold up, and axial dispersion number were obtained from empirical correlations in the literatures. The drying rate of ammonium sulphate fertilizer in rotary dryer was estimated using isothermal diffusion model with effective diffusivity of moisture in the particle obtained from previous study [2]. Using Gamma function distribution, this research showed that for the value of the coefficient of variance (CV less than 0.5, particle size distribution does not have significant effect on dryer performance. For the value of CV greater than 0.5, the dryer performance increase (or outlet solid moisture content decrease with increasing the value of CV. The application of Rosin-Rammler model gives lower prediction of outlet solid moisture content compared to the application of Gamma function model.

  3. Investigation of the process rotary turning by multi-faceted cutters

    Science.gov (United States)

    Indakov, N. S.; Binchurov, A. S.; Gordeev, Y. I.; Yasinski, V. B.; Kiselyov, D. I.; Lepeshev, A. A.

    2017-10-01

    Effect of geometrical and technological parameters of method rotary turning by multifaceted cutters (RTMC) on the quality of machining was investigated. Using the numerical, analytical and experimental methods the effect of cutting conditions on roughness was determed. The resulting semiempirical dependences allow to appoint the cutting conditions with predict roughness parameters Ra, Rz, R max.

  4. MECHANISMS GOVERNING TRANSIENTS FROM THE BATCH INCINERATION OF LIQUID WASTES IN ROTARY KILNS

    Science.gov (United States)

    When "containerized" liquid wastes, bound on sorbents. are introduced into a rotary kiln in a batch mode, transient phenomena in-volving heat transfer into, and waste mass transfer out of, the sorbent can oromote the raoid release of waste vaoor into the kiln environment. This ra...

  5. Effects of spray adjuvants on spray droplet size from a rotary atomizer

    Science.gov (United States)

    Rotary atomizers are used in a number of aerial applications, such as forest pest spraying and mosquito control sprays. These types of atomizers have a rotating cage at speeds of 2,000 to 10,000 rpm through which a spray is emitted and atomized. Many applicators routinely add spray adjuvants to ch...

  6. Rotary Instrument or Piezoelectric for the Removal of Third Molars: a Meta-Analysis.

    Science.gov (United States)

    Magesty, Rafael Alvim; Galvão, Endi Lanza; de Castro Martins, Carolina; Dos Santos, Cássio Roberto Rocha; Falci, Saulo Gabriel Moreira

    2017-03-01

    The aim of this systematic review and meta-analysis was to compare, in the lower third molar surgery, the osteotomy techniques with rotary instruments and piezoelectric motors. An electronic search was conducted using the following databases: Pubmed, Web of Science, and the Cochrane Oral Health Group Trials Register. Inclusion criteria were: studies in humans, randomized or nonrandomized, comparing the extraction of third molars that required osteotomy and/or odontosection with rotary instrument and osteotomy and/or odontosection with piezoelectric motor assistance. The analysis and inclusion of articles was performed by two reviewers independently. An evaluation of the quality of articles and data extraction was carried out. From a total of nine hundred seventy four (974) trials, eleven articles were included in the qualitative analysis, and seven were included in the quantitative analysis. Rotary instruments were faster than the piezoelectric surgery (95 % CI 0.34 to 1.16). The piezoelectric surgery showed better results when compared with roatry instruments when trismus was assessed in 2 (95 % CI 0.65 to 1.69), 3 (95 % CI 0.63 to 1.67) and 5 (95 % CI 0.03 to 2.26) days after surgery. Seven days after surgery, there were no differences between the techniques (95 % CI (-0.022) to (-1.49)). The piezoelectric surgery was effective in reducing pain, swelling and trismus in third molar surgery, but the same requires greater surgical time than the rotary instruments.

  7. Experimental Study of Drag Resistance using a Laboratory Scale Rotary Set-Up

    DEFF Research Database (Denmark)

    Erik Weinell, Claus; Olsen, Kenneth N.; Christoffersen, Martin W.

    2003-01-01

    This work covers an experimental study of the drag resistance of different painted surfaces and simulated large-scale irregularities, viz. dry spraying, weld seams, barnacle fouling and paint remains. A laboratory scale rotary set-up was used to determine the drag resistance, and the surface...

  8. A novel optical rotary encoder with eccentricity self-detection ability

    Science.gov (United States)

    Li, Xuan; Ye, Guoyong; Liu, Hongzhong; Ban, Yaowen; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2017-11-01

    Eccentricity error is the main error source of optical rotary encoders. Real-time detection and compensation of the eccentricity error is an effective way of improving the accuracy of rotary optical encoders. In this paper, a novel rotary optical encoder is presented to realize eccentricity self-detection. The proposed encoder adopts a spider-web-patterned scale grating as a measuring standard which is scanned by a dual-head scanning unit. Two scanning heads of the dual-head scanning unit, which are arranged orthogonally, have the function of scanning the periodic pattern of the scale grating along the angular and radial directions, respectively. By this means, synchronous measurement of angular and radial displacements of the scale grating is realized. This paper gives the details of the operating principle of the rotary optical encoder, developing and testing work of a prototype. The eccentricity self-detection result agrees well with the result measured by an optical microscope. The experimental result preliminarily proves the feasibility and effectiveness of the proposed optical encoder.

  9. Solvent effects on the thermal isomerization of a rotary molecular motor

    NARCIS (Netherlands)

    Lubbe, Anouk S.; Kistemaker, Jos C. M.; Smits, Esther J.; Feringa, Ben L.

    2016-01-01

    As molecular machines move to exciting applications in various environments, the study of medium effects becomes increasingly relevant. It is difficult to predict how, for example, the large apolar structure of a light-driven rotary molecular motor is affected by a biological setting or surface

  10. A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.

    Science.gov (United States)

    Mokhtari, Negar; Shirazi, Alireza-Sarraf; Ebrahimi, Masoumeh

    2017-11-01

    Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests (Protary files (P=0.000). Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words:Rotary technique, conventional technique, pulpectomy, primary teeth.

  11. Experimental Test of a New Precision Model for Microwave Rotary Vane Attenuators

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom; Guldbrandsen, Birthe; Warner, Frank L.

    1983-01-01

    Detailed measurements of scattering parameters have been made on a precision rotary vane attenuator (RVA) with high-resolution, direct angular readout. The aim of the measurements has been to test if the RVA can be used as a primary standard of attenuation by taking advantage of a precision model...

  12. Failure Analysis in Space: International Space Station (ISS) Starboard Solar Alpha Rotary Joint (SARJ) Debris Analysis

    Science.gov (United States)

    Long, V. S.; Wright, M. C.; McDanels, S. J.; Lubas, D.; Tucker, B.; Marciniak, P. J.

    2010-01-01

    This slide presentation reviews the debris analysis of the Starboard Solar Alpha Rotary Joint (SARJ), a mechanism that is designed to keep the solar arrays facing the sun. The goal of this was to identify the failure mechanism based on surface morphology and to determine the source of debris through elemental and particle analysis.

  13. How to manage MTTF larger than 30,000hr on rotary cryocoolers

    Science.gov (United States)

    Cauquil, Jean-Marc; Seguineau, Cédric; Martin, Jean-Yves; Van-Acker, Sébastien; Benschop, Tonny

    2017-05-01

    The cooled IR detectors are used in a wide range of applications. Most of the time, the cryocoolers are one of the components dimensioning the lifetime of the system. Indeed, Stirling coolers are mechanical systems where wear occurs on millimetric mechanisms. The exponential law classically used in electronics for Mean Time to Failure (MTTF) calculation cannot be directly used for mechanical devices. With new applications for thermal sensor like border surveillance, an increasing reliability has become mandatory for rotary cooler. The current needs are above several tens of thousands of continuous hour of cooling. Thales Cryogenics made specific development on that topic, for both linear and rotary applications. The time needed for validating changes in processes through suited experimental design is hardly affordable by following a robust and rigorous standard scientific approach. The targeted Mean Time to Failure (MTTF) led us to adopt an innovative approach to keep development phases in line with expected time to market. This innovative approach is today widespread on all of Thales Cryogenics rotary products and results in a proven increase of MTTF for RM2, RM3 and recently RM1. This paper will then focused on the current MTTF figures measured on RM1, RM2 and RM3. After explaining the limit of a conventional approach, the paper will then describe the current method. At last, the authors will explain how these principles are taken into account for the new SWaP rotary cooler of Thales Cryogénie SAS.

  14. ISS Solar Array Alpha Rotary Joint (SARJ) Bearing Failure and Recovery: Technical and Project Management Lessons Learned

    Science.gov (United States)

    DellaCorte, Christopher; Krantz, Timothy L.; Dube, Michael J.

    2011-01-01

    The photovoltaic solar panels on the International Space Station (ISS) track the Sun through continuous rotating motion enabled by large bearings on the main truss called solar array alpha rotary joints (SARJs). In late 2007, shortly after installation, the starboard SARJ had become hard to turn and had to be shut down after exceeding drive current safety limits. The port SARJ, of the same design, had been working well for over 2 years. An exhaustive failure investigation ensued that included multiple extravehicular activities to collect information and samples for engineering forensics, detailed structural and thermal analyses, and a careful review of the build records. The ultimate root cause was determined to be kinematic design vulnerability coupled with inadequate lubrication, and manufacturing flaws; this was corroborated through ground tests, metallurgical studies, and modeling. A highly successful recovery plan was developed and implemented that included replacing worn and damaged components in orbit and applying space-compatible grease to improve lubrication. Beyond the technical aspects, however, lie several key programmatic lessons learned. These lessons, such as running ground tests to intentional failure to experimentally verify failure modes, are reviewed and discussed so they can be applied to future projects to avoid such problems.

  15. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    2015-01-01

    a labor market position for (female) spouses with limited alternative opportunities. This decision has positive effects: the financial benefits for each of the spouses, and especially the fe-male, are larger in co-entrepreneurial firms, both during the life of the business and post-dissolution. This also......We study motivations for and outcomes of couples starting up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010, while comparing them to a set of comparable firms and couples. The main motivation for joint entrepreneurship is to create...

  16. Comparative Study of Piezoelectric and Rotary Osteotomy Technique for Third Molar Impaction.

    Science.gov (United States)

    Basheer, Sulphi A; Govind, R Jay; Daniel, Augustine; Sam, George; Adarsh, V J; Rao, Akshatha

    2017-01-01

    Bone removal is necessary for extracting the third molars that are erupted, partially erupted, and/or impacted in bone. Hence, it is necessary to choose a surgical method or instruments that conform to anatomic landmarks and are based on physiological principles. Many authors have reported injuries to the adjacent tooth, especially the distal part of periodontium after removal of second molar. Hence, the present study was undertaken to assess and compare the surgical and postsurgi-cal outcomes of third molar removal using piezoelectric surgery and rotary bur. A total of 30 healthy adult individuals who were in need of prophylactic removal of impacted man-dibular third molar tooth with ideal condition were included for the study. Individuals were divided randomly into study groups of 15 each, so that the difficulty of surgery will be the same in both the groups. Group I - piezoelectric osteotomy technique and group II - rotary osteotomy technique. The rotary device consists of a hand piece and a rotary speed ranging around 35,000 rpm was used. The piezoelectric device consists of a hand piece, and a frequency of 25 to 29 kHz with a microvibration of 60 to 200 mm/sec was used with a boosted working mode. Data were analyzed using unpaired t-test and qualitative data were analyzed using Fischer's exact test. The average age of the study subjects in the piezo-surgery group and rotary group was 28.40 ± 2.69 and 30.06 ± 3.15 years respectively. The time taken for removal of impacted tooth by rotary bur was less than that by piezoelectric device, which was significant statistically (p piezoelectric group as compared with rotary bur until the 7th postoperative day. The piezosurgery method reduces postoperative pain, trismus, and swelling. Also, it may play an important role in increasing bone density within the extraction socket and decreasing the amount of bone loss of adjacent tooth in the distal aspect. In clinical practice, piezosurgery plays an important role because

  17. Evaluation of the efficacy of rotary vs. hand files in root canal preparation of primary teeth in vitro using CBCT.

    Science.gov (United States)

    Musale, P K; Mujawar, S A V

    2014-04-01

    This in vitro study aimed to evaluate the efficacy of rotary ProFile, ProTaper, Hero Shaper and K-files in shaping ability, cleaning efficacy, preparation time and instrument distortion in primary molars. Sixty extracted primary mandibular second molars were divided into four equal groups: Group I K-file, Group II ProFile, Group III ProTaper file and Group IV Hero Shaper file. The shaping ability was determined by comparing pre- and post-instrumentation CBCT scans and data analysed with SPSS program using the Chi-square test. Cleaning efficacy was evaluated by the degree of India ink removal from the canal walls under stereomicroscopy. Instrumentation times were calculated for each tooth and instrument distortion was visually checked and duly noted. The cleaning efficacy and instrumentation time were determined using ANOVA with Tukey's correction. Instrument distortion was analysed using Chi-square test. The canal taper was significantly more conical for rotary files as compared to K-files with Chi-square test (p rotary files with average scores (Groups II- 0.68, III- 0.48 and IV- 0.58) was significantly better than K-files (Group I- 0.93) (p rotary files (Groups II 8.9, III 5.6, and IV 8.1 min) (p rotary files were distorted. Rotary files prepared more conical canals in primary teeth than manual instruments. Reduced preparation time with rotary files enhances patient cooperation especially in young children.

  18. Rotor hover performance and system design of an efficient coaxial rotary wing micro air vehicle

    Science.gov (United States)

    Bohorquez, Felipe

    2007-12-01

    Rotary-wing Micro air vehicles (MAVs) due to their unique hovering and low-speed flight capabilities are specially suited for missions that require operation in constrained spaces. Size restrictions force MAVs to operate in a low Reynolds number aerodynamic regime where viscous effects are dominant. This results in poor aerodynamic performance of conventional airfoils and rotor configurations. This dissertation explores the design issues that affect the hover performance of small-scale rotors and the implementation of a working coaxial MAV prototype. A computerized hover test stand was used for the systematic testing of single and coaxial small-scale rotors. Thin circular arcs were chosen for blade manufacturing because of their good aerodynamic characteristics at low Reynolds numbers, and simplified parameterization. Influence of airfoil geometry on single rotor hover performance was studied on untwisted rectangular blades. Non rectangular blades were used to study coupled airfoil and blade parameters. Tip tapered geometries were manufactured by removing material from baseline rectangular blades producing a coupling between blade planform, twist distribution, and spanwise airfoil shape. Performance gains were obtained by introducing large negative twist angles over short radial distances at the blade tips. A parametric study of the blade geometries resulted in maximum figures of merit of 0.65. Coaxial rotor performance at torque equilibrium was explored for different trims and operating conditions. It was found that the upper rotor was marginally affected by the lower one at spacings larger than 35% of the rotor radius, and that it produced about 60% of the total thrust. Experiments showed that power loading was maximized when higher collectives were used at the lower rotor, resulting in sizable differences in rotational speed between rotors. The CFD solver INS2d was used for a two-dimensional parametric aerodynamic study of circular arc airfoils. Lift, drag, and

  19. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse - most commonly the female - has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female......We study possible motivations for co-entrepenurial couples to start up a joint firm, us-ing a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes......, are larger in co-entrepreneurial firms, both during the life of the business and post-dissolution. The start-up of co-entrepreneurial firms seems therefore a sound in-vestment in the human capital of both spouses as well as in the reduction of income inequality in the household. We find no evidence of non...

  20. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse – most commonly the female – has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female......We study possible motivations for co-entrepenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and postdissolution private and financial outcomes......, are larger in co-entrepreneurial firms, both during the life of the business and post-dissolution. The start-up of co-entrepreneurial firms seems therefore a sound investment in the human capital of both spouses as well as in the reduction of income inequality in the household. We find no evidence of non...

  1. Design of a rotary for an uncontrolled multi-leg intersection in Chennai, India

    Science.gov (United States)

    Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam

    2017-11-01

    One way to control the traffic at busy intersections is to construct a roundabout or rotary intersection, which is a special type of at-grade intersection, where all converging vehicles are forced to move round a central island in clock-wise direction. The present study aims to design a rotary for an uncontrolled multi leg intersection located in Royapetah in Chennai, India. The intersection has five approach roads with two-way traffic in all the approach roads and there is no signal or traffic police to control the traffic at present and hence experiences traffic chaos during peak hours. In order to design the rotary, it is essential to have the information on traffic volumes coming from the approach roads. For this, a video data collection was carried out for a duration of eight hours from 7.30 am to 11.30 am and from 2.30 pm to 6.30 pm on a typical working day using a handycam from the terrace of an apartment building located near the intersection. During data extraction stage, each 5 min. traffic volume was extracted for all the five classes of vehicles considered and were converted to passenger car units (PCU). The analysis of traffic data showed that during peak hour from 4.45 pm to 5.45 pm, the proportion of weaving traffic, i.e., ratio of sum of crossing streams to the total traffic on the weaving section was found to be 0.81. According to Indian road congress (IRC) guidelines, this proportion can take any value between 0.4 and 1 and in the present study, the calculated value is found to be within the prescribed range. Using the calculated values of average entry width of the rotary and width & length of weaving section, the practical capacity of the rotary was found to be 3020 PCUs which is well above the observed traffic volume of 2665 PCUs.

  2. Performance and efficiency evaluation and heat release study of a direct-injection stratified-charge rotary engine

    Science.gov (United States)

    Nguyen, H. L.; Addy, H. E.; Bond, T. H.; Lee, C. M.; Chun, K. S.

    1987-01-01

    A computer simulation which models engine performance of the Direct Injection Stratified Charge (DISC) rotary engines was used to study the effect of variations in engine design and operating parameters on engine performance and efficiency of an Outboard Marine Corporation (OMC) experimental rotary combustion engine. Engine pressure data were used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine data were compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the rotary engine using advanced heat engine concepts such as faster combustion, reduced leakage, and turbocharging is also presented.

  3. Assessment of Apical Extrusion of Debris during Endodontic Retreatment with 3 Rotary Nickel-Titanium Retreatment Systems and Hand Files

    Directory of Open Access Journals (Sweden)

    Gkampesi S.

    2016-03-01

    Full Text Available Aim: to evaluate the amount of debris extruded apically as well as the time needed for removal of root canal filling material using ProTaper, MTwo, REndo NiTi rotary retreatment systems and hand files.

  4. Comparative study of apically extruded debris using one manual and two rotary instrumentation techniques for endodontic retreatment

    Directory of Open Access Journals (Sweden)

    Alper Kustarci

    2012-03-01

    Conclusion: All retreatment techniques produced extruded debris during endodontic retreatment; however, both rotary NiTi systems were associated with less apical extrusion than manual instrumentation with Hedström files.

  5. [Analysis of interappointment flare-ups after root canal preparation with Mtwo NiTi rotary system].

    Science.gov (United States)

    Han, Jun-li; He, Hong; Zhu, Ya-qin

    2011-08-01

    To study the interappointment flare-ups after root canal preparation with Mtwo NiTi rotary system and explore the influence factors. Ninty-seven pulp cases caused by caries or invisible cracks which consisted of 37 males and 60 females,16 to 62 years old were selected and divided into 2 groups randomly. One group was treated with Mtwo NiTi rotary system while the other was treated with K file, the interappointment flare-ups after root canal preparation was compared between the 2 groups. The data were subjected to Mann-Whitney U test and X(2) test with SPSS13.0 software package. Less flare-ups occurred in the group of root canal preparation with NiTi rotary system, the difference was statistically significant (P=0.027). Root canal preparation with Mtwo NiTi rotary system could decrease the flare-ups after root canal therapy.

  6. Stress Analysis of Rotary Vibration of Rigid Friction Pile and Stress General Solution of Central Symmetry Plane Elastic Problem

    OpenAIRE

    Fu-yao Zhao; Er-xiang Song; Jun Yang

    2015-01-01

    The rotary vibration of rigid friction pile can be seen approximately as a central symmetry plane problem in elasticity. The stress general solution of central symmetry plane problem in elasticity can be constructed by technique such as the Laurent expansion of the volume force. This solution has some decoupling, generalized, and convergent properties, and it can be used in stress analysis of the rotary vibration of pile. The analysis results show that the maximum value of displacement will n...

  7. Comparison of Cleaning Efficacy and Instrumentation Time in Primary Molars: Mtwo Rotary Instruments vs. Hand K-Files

    OpenAIRE

    Ramezanali, Fatemeh; Afkhami, Farzaneh; Soleimani, Ali; Kharrazifard, Mohammad Javad; Rafiee, Farshid

    2015-01-01

    Introduction: Pulpectomy is the preferred treatment for restorable primary teeth with symptomatic irreversible pulpitis or periradicular lesion. Considering the rather new application of rotary files for pulpectomy of primary teeth, the aim of this study was to compare the cleaning efficacy and instrumentation time of hand K-files and Mtwo rotary system for preparation of human primary molars. Methods and Materials: This experimental study was conducted on 100 extracted primary maxillary and ...

  8. Comparative Evaluation of Cleaning Efficacy using Four Novel Nickel-titanium Rotary Instruments: An in vitro Scanning Electron Microscope Study.

    Science.gov (United States)

    Kar, Prem P; Khasnis, Sandhya A; Kidiyoor, Krisnamurthy H

    2017-12-01

    The aim of the study was to compare the cleaning efficacy (debris and smear layer removal) of two multifile rotary systems (MTwo and Silk) and two single-file rotary systems (F6 Skytaper and NeoNiTi). Eighty mesial canals of mandibular first molars were cleaned and shaped using four nickel-titanium (NiTi) rotary instruments to size # 25 and 3% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA). Samples were randomly divided into four equal groups (n = 20) according to instrumentation: Group I, Mtwo; group II, Silk; group III, F6 Skytaper; group IV, NeoNiTi. Samples were split longitudinally and examined under scanning electron microscope (SEM) for debris and smear layer removal in coronal, middle, and apical thirds of each root canal. F6 skytaper and Mtwo groups showed significantly higher debris removal than Silk and NeoNiTi groups in apical third of root canal as well as when compared with NeoNiTi group in middle third. F6 Skytaper group showed significantly higher debris and smear layer removal than Silk group in coronal third. There was statistically significant difference among all thirds of root canal in terms of debris removal in Silk and NeoNiTi groups. There was statistically significant difference among all thirds of root canal in F6 Skytaper and NeoNiTi groups in terms of smear layer removal. F6 Skytaper single-file rotary instrumentation showed the maximum cleaning efficacy followed by Mtwo multifile rotary instrumentation in all thirds of root canal. F6 Skytaper rotary instrument is most efficient followed by Mtwo rotary instrument among all rotary instruments.

  9. Design, development and evaluation of a precision air bearing rotary table with large diameter through-hole

    Energy Technology Data Exchange (ETDEWEB)

    Accatino, Mark R. [Univ. of California, Davis, CA (United States)

    1991-11-01

    A large diameter precision air bearing rotary table with a 16.0 inch diameter through-hole was designed, fabricated and tested in the course of this research. The rotary table will be used in conjunction with a specialized, computer controlled precision inspection machine being designed for the Department of Energy`s (DOE) Nuclear Weapons Complex (NWC). The design process included a complete engineering analysis to predict the final performance of the rotary table, and to ensure that the rotary table meets the required accuracy of 4.0 microinches of total radial (3.5 microinches average radial) and 4.0 microinches total axial (3.5 microinches average axial) errors. The engineering analysis included structural deformation, thermal sensitivity and dynamic analyses using finite element methods in some cases, as well as other analytic solutions. Comparisons are made between predicted and tested values, which are listed in the rotary table error budget. The rotary table performed as predicted with measured axial and radial stiffnesses of 1.1 x 106 lbf/inch and 2.9 x 106 lbf/inch, respectively, as well as average radial, axial and tilt errors of 2.5 microinches, 1.5 microinches, and less than 0.05 arcseconds, respectively.

  10. Understanding of Low Reynolds Number Aerodynamics and Micro Rotary-Wing Air Vehicles

    Science.gov (United States)

    Winslow, Justin Michael

    The goal of the present research is to understand aerodynamics at low Reynolds numbers and synthesize rules towards the development of hovering micro rotary-wing air vehicles (MRAVs). This entailed the rigorous study of airfoil characteristics at low Reynolds numbers through available experimental results as well as the use of an unsteady Reynolds-Averaged Navier-Stokes solver. A systematic, experimental, variation of parameters approach with physical rotors was carried out to design and develop a micro air vehicle-scale rotor which maximizes the hover Figure of Merit. The insights gained in low Reynolds number aerodynamics have been utilized in the systematic design of a high endurance micro-quadrotor. Based on available characteristics, the physical relations governing electric propulsion system and structural weights have been derived towards a sizing methodology for small-scale rotary-wing vehicles.

  11. Development, characterization and testing of tungsten doped DLC coatings for dry rotary swaging

    Directory of Open Access Journals (Sweden)

    Hasselbruch Henning

    2015-01-01

    Full Text Available The extensive use of lubricant during rotary swaging is particularly required for a good surface finish of the work piece and the reduction of tool wear. Abandonment of lubricant would improve the ecological process-balance and could also accelerate for further work piece refinements. Also cleaning of the manufactured components becomes obsolete. Thus, a dry machining is highly innovative, consequently new strategies to substitute the lubricant functions become necessary. To encounter the changed tribological conditions due to dry rotary swaging, low friction, tungsten doped, hard DLC coatings and structured surfaces are the most promising approaches. In this work the development of hard coating by means of reactive magnetron sputtering is presented, a promising layer variant is deposited on a set of tools and then tested and investigated in real use.

  12. A quantitative analysis of rotary, ultrasonic and manual techniques to treat proximally flattened root canals

    Directory of Open Access Journals (Sweden)

    Fabiana Soares Grecca

    2007-04-01

    Full Text Available OBJECTIVE: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i K3 and ProTaper rotary systems; (ii ultrasonic crown-down technique; and (iii progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus non-instrumented area on which dye remained. RESULTS: No statistically significant difference was found between the instrumentation techniques studied (p<0.05. CONCLUSION: The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye.

  13. On the impact of rolling direction and tool orientation angle in Rotary Peen Forming

    Science.gov (United States)

    Gottschalk, M.; Hirt, G.

    2016-10-01

    Shot Peen Forming processes are suitable to produce surface curvatures that are commonly required for aircraft fuselage as well as structural components. The so called Rotary Peen Forming is an alternative process for manufacturing sheet metals with slight curvature. The forming tool consists of impactors which are connected flexibly to a rotating hub and thus moving on a circular trajectory. An industrial robot guides the Rotary Peen Forming tools. As a result, the machine design is more compact compared to traditional Shot Peen Forming. In the present work, the impact of both, the tool orientation angle and the rolling direction, on the curvature of aluminum AA5083 samples is examined. By means of a point laser measurement, the set-up enables a distance control to adjust a determined indentation depth. It can be shown, that the highest curvature is achieved when the tool is orientated parallel and when the rolling direction of the sheet metal is transversal to the curvature plane.

  14. Unidirectional rotary motion in a liquid crystalline environment: Color tuning by a molecular motor

    Science.gov (United States)

    van Delden, Richard A.; Koumura, Nagatoshi; Harada, Noboyuki; Feringa, Ben L.

    2002-01-01

    Life could not exist without motion induced by a variety of molecular motors. The construction of artificial motors by chemical synthesis, which can power motions that lead to macroscopic detectable effects in a system, is a major endeavor in contemporary science. To move toward this goal, a host–guest system, composed of a nematic liquid crystal film doped with a chiral light-driven molecular motor, is assembled. Irradiation of the film results in unidirectional rotary motion of the molecular motor, which induces a motion of the mesogenic molecules leading to a molecular reorganization and, as a consequence, a change in the color of the film. In this way, by control of the rotary motion at the molecular level, color tuning over the entire visible spectrum is achieved. These findings demonstrate that a molecular motor can exert a visually observable macroscopic change in a material. PMID:11929969

  15. Devolatilization and Combustion of Tire Rubber and Pine Wood in a Pilot Scale Rotary Kiln

    DEFF Research Database (Denmark)

    Nielsen, Anders R.; Larsen, Morten B.; Glarborg, Peter

    2012-01-01

    of industrial waste. In this study, devolatilization and combustion of large particles of tire rubber and pine wood with equivalent diameters of 10 mm to 26 mm are investigated in a pilot scale rotary kiln able to simulate the process conditions present in the material inlet end of cement rotary kilns....... Investigated temperatures varied from 700 to 1000 °C, and oxygen concentrations varied from 5% v/v O2 to 21% v/v O2. The devolatilization time of tire rubber and pine wood were found to mainly depend on temperature and particle size and were within 40 to 170 s. Rate limiting parameters for char oxidation...... of tire rubber and pine wood were found to be bulk oxygen concentration, mass transfer rate of oxygen, raw material fill degree, raw material characteristics, and temperature. Kiln rotational speed only had a minor effect on the char oxidation when the raw material bed was in a rolling motion. Initial...

  16. TESTING OF A FULL-SCALE ROTARY MICROFILTER FOR THE ENHANCED PROCESS FOR RADIONUCLIDES REMOVAL

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D; David Stefanko, D; Michael Poirier, M; Samuel Fink, S

    2009-01-01

    Savannah River National Laboratory (SRNL) researchers are investigating and developing a rotary microfilter for solid-liquid separation applications in the Department of Energy (DOE) complex. One application involves use in the Enhanced Processes for Radionuclide Removal (EPRR) at the Savannah River Site (SRS). To assess this application, the authors performed rotary filter testing with a full-scale, 25-disk unit manufactured by SpinTek Filtration with 0.5 micron filter media manufactured by Pall Corporation. The filter includes proprietary enhancements by SRNL. The most recent enhancement is replacement of the filter's main shaft seal with a John Crane Type 28LD gas-cooled seal. The feed material was SRS Tank 8F simulated sludge blended with monosodium titanate (MST). Testing examined total insoluble solids concentrations of 0.06 wt % (126 hours of testing) and 5 wt % (82 hours of testing). The following are conclusions from this testing.

  17. Treatment of gingival hyperpigmentation with rotary abrasive, scalpel, and laser techniques: A case series

    Science.gov (United States)

    Murthy, M Bhanu; Kaur, Jasjit; Das, Rupali

    2012-01-01

    Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin, due to which the gums may appear black, but the principles, techniques, and management of the problems associated with gingival melanin pigmentation are still not fully established. Depigmentation procedures such as scalpel surgery, gingivectomy with free gingival autografting, electrosurgery, cryosurgery, chemical agents such as 90% phenol and 95% alcohol, abrasion with diamond bur, Nd: YAG laser, semiconductor diode laser, and CO2 laser have been employed for removal of melanin hyper pigmentation. The following case series describes three different surgical depigmentation techniques: scalpel surgery, abrasion with rotary abrasive, and a diode laser. Better results of depigmentation were achieved with diode laser than conventional scalpel and with rotary abrasion with respect to esthetics. The results point out that lasers are an effective and a safe means to removal of hyperpigmentation from the gingiva. Healing was uneventful and no repigmentation occurred. PMID:23493062

  18. Neural Network modeling of forward and inverse behavior of rotary MR damper

    DEFF Research Database (Denmark)

    Bhowmik, Subrata; Høgsberg, Jan Becker; Weber, Felix

    2010-01-01

    Magneto-rheological (MR) dampers have received considerable attention within the last decades, mainly because of their design simplicity, low power requirements, large force range and robustness. The most common models to describe the dynamic MR damper behavior are the Bouc-Wen model, the Lu...... of nonlinear problems. The present paper concerns the nonparametric neural network modeling of the dynamic behavior of a rotary MR damper. A rotary type MR damper consists of a rotating disk which is enclosed in a metallic housing filled with the MR fluid which is operated in shear mode. The dissipative torque...... produced is transformed into a translational force through the crank shaft mechanism. A feed-forward back propagation neural network is used to model both the forward and the inverse dynamics of the MR damper. The forward model output is the estimated force and therefore can be used later as observer...

  19. Theoretical Model for Predicting Moisture Ratio during Drying of Spherical Particles in a Rotary Dryer

    Directory of Open Access Journals (Sweden)

    F. T. Ademiluyi

    2013-01-01

    Full Text Available A mathematical model was developed for predicting the drying kinetics of spherical particles in a rotary dryer. Drying experiments were carried out by drying fermented ground cassava particles in a bench scale rotary dryer at inlet air temperatures of 115–230°C, air velocities of 0.83 m/s–1.55 m/s, feed mass of 50–500 g, drum drive speed of 8 rpm, and feed drive speed of 100 rpm to validate the model. The data obtained from the experiments were used to calculate the experimental moisture ratio which compared well with the theoretical moisture ratio calculated from the newly developed Abowei-Ademiluyi model. The comparisons and correlations of the results indicate that validation and performance of the established model are rather reasonable.

  20. Treatment of gingival hyperpigmentation with rotary abrasive, scalpel, and laser techniques: A case series.

    Science.gov (United States)

    Murthy, M Bhanu; Kaur, Jasjit; Das, Rupali

    2012-10-01

    Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin, due to which the gums may appear black, but the principles, techniques, and management of the problems associated with gingival melanin pigmentation are still not fully established. Depigmentation procedures such as scalpel surgery, gingivectomy with free gingival autografting, electrosurgery, cryosurgery, chemical agents such as 90% phenol and 95% alcohol, abrasion with diamond bur, Nd: YAG laser, semiconductor diode laser, and CO2 laser have been employed for removal of melanin hyper pigmentation. The following case series describes three different surgical depigmentation techniques: scalpel surgery, abrasion with rotary abrasive, and a diode laser. Better results of depigmentation were achieved with diode laser than conventional scalpel and with rotary abrasion with respect to esthetics. The results point out that lasers are an effective and a safe means to removal of hyperpigmentation from the gingiva. Healing was uneventful and no repigmentation occurred.

  1. Development of a space qualified high reliability rotary actuator. Volume 1: Technical report

    Science.gov (United States)

    Presley, R. W.; Read, R. G.; Sikora, N. L.

    1972-01-01

    A space-qualified, high reliability, 150 ft-lb rated torque rotary acutator based on the Bendix Dynavector drive concept was developed. This drive is an integrated variable reluctance orbit motor-epicyclic transmission actuator. The performance goals were based on future control moment gyro torquer applications and represent a significant advancement in the torque-to-weight ratio, backlash, inertia and response characteristics of electric rotary drives. The program accomplishments have been in two areas: (1) the development of two high ratio (818:1) actuator configurations (breadboard and flightweight), and (2) the invention of a reliable proximity switch sensor system for self-commutation without use of optical or electrical brush techniques.

  2. Rotary moving bed for CO.sub.2 separation and use of same

    Science.gov (United States)

    Elliott, Jeannine Elizabeth; Copeland, Robert James; McCall, Patrick P.

    2017-01-10

    A rotary moving bed and process for separating a carbon dioxide from a gas stream is disclosed. The rotary moving bed can have a rotational assembly rotating on a vertical axis, and a plurality of sorbent cells positioned horizontally to the axis of rotation that fills a vertical space in the moving bed, where the sorbent cells adsorb the carbon dioxide by concentration swing adsorption and adsorptive displacement. The sorbent can be regenerated and the carbon dioxide recaptured by desorbing the carbon dioxide from the sorbent using concentration swing adsorption and desorptive displacement with steam. The gas flows in the system flow in a direction horizontal to the axis of rotation and in a direction opposite the rotational movement of the sorbent cells.

  3. Research on Power Calculation Method of High Speed Rotary Device under Wind Loads Crystals

    Science.gov (United States)

    Ji, M. S.; Xue, Y.; Wu, N.

    2017-10-01

    The wind load has a great influence on the power of large rotary devices working outdoors. In the power calculation formula of the rotary devices, the static air pressure is often used as the wind resistance of the whole device. But in fact, the rotating device bears the dynamic wind pressure during the rotation. This method of calculation will lead to large deviation. Based on this, this paper emphatically studied the dynamic wind load of the rotating device under rotation, and gave a more accurate formula for the calculation of the rotating power. This formula solves the problem of power calculation of the rotating device in high speed rotation. It can be widely used in all kinds of rotating devices.

  4. Haptic Addition to a Visual Menu Selection Interface Controlled by an In-Vehicle Rotary Device

    OpenAIRE

    Camilla Grane; Peter Bengtsson

    2012-01-01

    Today, several vehicles are equipped with a visual display combined with a haptic rotary device for handling in-vehicle information system tasks while driving. This experimental study investigates whether a haptic addition to a visual interface interferes with or supports secondary task performance and whether haptic information could be used without taking eyes off road. Four interfaces were compared during simulated driving: visual only, partly corresponding visual-haptic, fully correspondi...

  5. A Method For Producing Hollow Shafts By Rotary Compression Using A Specially Designed Forging Machine

    OpenAIRE

    Tomczak J.; Bulzak T.; Pater Z.

    2015-01-01

    The paper presents a new method for manufacturing hollow shafts, where tubes are used as billet. First, the design of a specially designed forging machine for rotary compression is described. The machine is then numerically tested with regard to its strength, and the effect of elastic strains of the roll system on the quality of produced parts is determined. The machine’s strength is calculated by the finite element method using the NX Nastran program. Technological capabilities of the machin...

  6. Welding of AA1050 aluminum with AISI 304 stainless steel by rotary friction welding process

    OpenAIRE

    Chen Ying An; Francisco Piorino Neto; Eder Paduan Alves

    2010-01-01

    Abstract: The purpose of this work was to assess the development of solid state joints of dissimilar material AA1050 aluminum and AISI 304 stainless steel, which can be used in pipes of tanks of liquid propellants and other components of the Satellite Launch Vehicle. The joints were obtained by rotary friction welding process (RFW), which combines the heat generated from friction between two surfaces and plastic deformation. Tests were conducted with different welding process parameters. The ...

  7. Joint Service Aircrew Mask (JSAM) Rotary Wing (RW): MPU-5 Noise Attenuation Performance

    Science.gov (United States)

    2016-06-09

    specifications and exceeded the attenuation performance of the helmets alone. 1.0 INTRODUCTION The noise environment in the cockpit of... cockpit and to provide satisfactory voice communications. The HGU-56/P and HGU-84/P were rotary wing aircrew helmet systems manufactured by Gentex...hood/hoodring subassembly, (2) face plate subassembly and (3) supply subassembly. The hood assembly and face plate assembly are shown in Figure 2

  8. Unbalance Identification of Speed-Variant Rotary Machinery without Phase Angle Measurement

    OpenAIRE

    Cong Yue; Xingmin Ren; Yongfeng Yang; Wangqun Deng

    2015-01-01

    As rotary mechanical structure becomes more complicated, difficulty arises in receiving prime correction mass and optimum balancing plane efficiently. An innovative modal balancing process for estimating the residual unbalance from different equilibrium plane of complex flexible rotor system is presented. The method is based on a numerical approach with modal ratio among measurement points (MRMP) coefficient and triple phase method (TPM). The veracity of calculation result is verified by an a...

  9. Slimming down: Small rotary steerable systems broaden directional market. Are shallow gas wells next?

    Energy Technology Data Exchange (ETDEWEB)

    Roche, P.

    2003-12-01

    Drilling an offshore well in an environmentally sensitive area just off the southern coast of England is described. Instead of building an artificial island, BP decided to use a new technology and drill the well from shore. The technique is known as extended-reach drilling; one of the wells in the field had a measured total depth of 37,001 feet, more than eleven kilometres. The technology that made this well possible is known as rotary steerable drilling. The technology is expensive, but the field has an estimated 447 million barrels of recoverable oil, and very prolific individual wells, hence economically justifiable. The technology is most suited to expensive offshore wells, but developers of rotary steerable systems -- Schlumberger Oilfield Services and Precision Drilling Corporation -- believe that the slim-hole tools they are developing have broadened the market to include smaller operators drilling less-costly onshore wells. Experts predict that the system eventually could be economic even on shallow-gas wells in Western Canada. The two service companies have steerable systems that drill six-inch boreholes, and Schlumberger is currently working on a system to drill four and a half inch holes. The smaller diameter rotary steerable systems have a great future in draining smaller oil pools that would not be economical if pools had to linked with conventional eight and a half inch boreholes. The prime example is Shell Exploration and Production of Britain, a drilling contractor that has been successfully using slim-hole systems in its North Sea operations to drill wells that would not otherwise get drilled. Although the rotary steerable business currently is concentrated in southwestern England, slim-hole systems have also been used in other mature fields in the Gulf of Mexico, Norway and even the Middle East and the Far East.

  10. Machining of Some Difficult-to-Cut Materials with Rotary Cutting Tools

    OpenAIRE

    Stjernstoft, Tero

    2004-01-01

    Automobile and aero industries have an increasing interestin materials with improved mechanical properties. However, manyof these new materials are classified as difficult-to-cut withconventional tools. It is obvious that tools, cutting processesand cutting models has to be devel-oped parallel to materialsscience. In this thesis rotary cutting tools are tested as analternative toexpensive diamond or cubic bore nitridetools. Metal matrix composites mostly consist of a light metalalloy (such as...

  11. An analysis of the relationship of flight hours and naval rotary wing aviation mishaps

    Science.gov (United States)

    2017-03-01

    due to the physiological nature of human circadian rhythm and reduced situational awareness from a lack of natural lighting. Overwater flight lacks...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release. Distribution is unlimited. AN ANALYSIS OF...COVERED Master’s thesis 4. TITLE AND SUBTITLE AN ANALYSIS OF THE RELATIONSHIP OF FLIGHT HOURS AND NAVAL ROTARY WING AVIATION MISHAPS 5. FUNDING

  12. Performance of Rotary Cutter Type Breaking Machine for Breakingand Deshelling Cocoa Roasted Beans

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2005-12-01

    Full Text Available Conversion of cocoa beans to chocolate product is, therefore, one of the promising alternatives to increase the value added of dried cocoa beans. On the other hand, the development of chocolate industry requires an appropriate technology that is not available yet for small or medium scale of business. Breaking and deshelling cocoa roasted beans is one important steps in cocoa processing to ascertain good chocolate quality. The aim of this research is to study performance of rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Indonesian Coffee and Cocoa Research Institute has designed and tested a rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Breaker unit has rotated by ½ HP power, single phase, 110/220 V and 1440 rpm. Transmission system that use for rotating breaker unit is pulley and single V belt. Centrifugal blower as separator unit between cotyledon and shell has specification 0.5 m 3 /min air flow, 780 Pa, 370 W, and 220 V. Field tests showed that the optimum capacity of the machine was 268 kg/h with 500 rpm speed of rotary cutter, 2,8 m/s separator air flow, and power require was 833 W. Percentage product in outlet 1 and 2 were 94.5% and 5.5%. Particle distribution from outlet 1 was 92% as cotyledon, 8% as shell in cotyledon and on outlet 2 was 97% as shell, 3% as cotyledon in shell. Key words:cocoa, breaking, rotary cutter, quality.

  13. Performance of Rotary Cutter Type Breaking Machine for Breakingand Deshelling Cocoa Roasted Beans

    OpenAIRE

    Sukrisno Widyotomo; Sri Mulato; Edi Suharyanto

    2005-01-01

    Conversion of cocoa beans to chocolate product is, therefore, one of the promising alternatives to increase the value added of dried cocoa beans. On the other hand, the development of chocolate industry requires an appropriate technology that is not available yet for small or medium scale of business. Breaking and deshelling cocoa roasted beans is one important steps in cocoa processing to ascertain good chocolate quality. The aim of this research is to study performance of rotary cutter type...

  14. Turbulence measurements in an axial rotary blood pump with laser Doppler velocimetry.

    Science.gov (United States)

    Schüle, Chan Y; Affeld, Klaus; Kossatz, Max; Paschereit, Christian O; Kertzscher, Ulrich

    2017-04-18

    The implantation of rotary blood pumps as ventricular assist devices (VADs) has become a viable therapy for quite a number of patients with end-stage heart failure. However, these rotary blood pumps cause adverse events that are related to blood trauma. It is currently believed that turbulence in the pump flow plays a significant role. But turbulence has not been measured to date because there is no optical access to the flow space in rotary blood pumps because of their opaque casings. This difficulty is overcome with a scaled-up model of the HeartMate II (HM II) rotary blood pump with a transparent acrylic housing. A 2-component laser Doppler velocimetry (LDV) system was used for the measurement of time resolved velocity profiles and velocity spectra upstream and downstream of the rotor blades. Observing similarity laws, the speed and pump head were adjusted to correspond closely to the design point of the original pump - 10,600 rpm speed and 80 mmHg pressure head. A model fluid consisting of a water-glycerol mixture was used. The measured velocity spectra were scalable by the Kolmogorov length and the Kolmogorov length was estimated to be between 14 and 24 µm at original scale, thus being about 1.5 to 3 times the size of a red blood cell. It can be concluded that turbulence is indeed present in the investigated blood pump and that it can be described by Kolmogorov's theory of turbulence. The size of the smallest vortices compares well to the turbulence length scales as found in prosthetic heart valves, for example.

  15. Root Canal Cleaning Efficacy of Rotary and Hand Files Instrumentation in Primary Molars

    Science.gov (United States)

    Nazari Moghaddam, Kiumars; Mehran, Majid; Farajian Zadeh, Hamideh

    2009-01-01

    INTRODUCTION: Pulpectomy of primary teeth is commonly carried out with hand files and broaches; a tricky and time consuming procedure. The purpose of this in vitro study was to compare the cleaning efficacy and time taken for instrumentation of deciduous molars using hand K-files and Flex Master rotary system. MATERIALS AND METHODS: In this study, 68 canals of 23 extracted primary molars with at least two third intact roots and 7-12 mm length were selected. After preparing an access cavity, K-file size #15 was introduced into the root canal and India ink was injected with an insulin syringe. Sixty samples were randomly divided in to experimental groups in group I (n=30), root canals were prepared with hand K-files; in group II (n=30), rotary Flex Master files were used for instrumentation, and in group III 8 remained samples were considered as negative controls. After clearing and root sectioning, the removal of India ink from cervical, middle, and apical thirds was scored. Data was analyzed using student's T-test and Mann-Whitney U test. RESULTS: There was no significant difference between experimental groups cleaning efficacy at the cervical, middle and apical root canal thirds. Only the coronal third scored higher in the hand instrumented group (P<0.001). Instrumentation with Flex Master rotary files was significantly less time consuming (P<0.001). CONCLUSION: Although there was no difference in cleanliness efficacy at the apical and middle thirds, the coronal third was more effectively cleaned with hand files. Predictably, time efficiency was a significant advantage with rotary technique. PMID:23940486

  16. Internal combustion engine with rotary valve assembly having variable intake valve timing

    Science.gov (United States)

    Hansen, Craig N.; Cross, Paul C.

    1995-01-01

    An internal combustion engine has rotary valves associated with movable shutters operable to vary the closing of intake air/fuel port sections to obtain peak volumetric efficiency over the entire range of speed of the engine. The shutters are moved automatically by a control mechanism that is responsive to the RPM of the engine. A foot-operated lever associated with the control mechanism is also used to move the shutters between their open and closed positions.

  17. [The influence of rotary manipulation on the internal pressure of cervical nucleus pulposus].

    Science.gov (United States)

    Sun, Shu-chun; Zhang, Jun; Wang, Li-heng; Zhao, Yi-jun; Liu, Xiu-qin; Zhang, Chun; Yu, Dong; Wang, De-long; Wu, Zhen; Chen, Zhao-hui; Zhao, Zhong-min; Han, Lei

    2010-01-01

    To measure the pressure changes inside the cervical nucleus pulposus in fresh human cervical specimen by imitating different rotary manipulations. The load of 100 N was applied for 5 second on the six fresh male cervical samples by using material test system, which imitated the human head weigh and the strength of cervical extensor muscle. After that, traction, rotation and pulling on the samples were performed in different sequence under the force of 150, 200, 300 N respectively. Three states were included in adding the load state A: samples were loaded with traction and then rotation to the biggest angle, pulling backward for 15 degrees; state B: samples were loaded with rotary stress to the biggest angle and then loaded with traction, pulling backward for 15 degrees; state C: samples were loaded simultaneously with traction and rotary stress to the biggest angle, pulling backward for 15 degrees. The internal pressure of cervical nucleus pulposus at segment of C(3,4), C(4,5), C(5,6), and C7 was measurred by micro-pressure sensors for state A, B, C and for the imitation of head weight and the strength of cervical extensor muscle. The pressure inside the cervical nucleus pulposus at segments C(5,6), C(6,7) was higher than that at segments C(3,4) and C(4,5) (P 0.05). There was a transitional pressure raise inside all cervical nucleus pulposus when pulling added after different sepuence traction and rotary strength was applied, however, the internal pressure of state A was significantly higher than that of state B or C (P manipulation in order to increase its safety.

  18. Pulmonary Valve Opening With Two Rotary Left Ventricular Assist Devices for Biventricular Support.

    Science.gov (United States)

    Wu, Eric L; Nestler, Frank; Kleinheyer, Matthias; Stevens, Michael C; Pauls, Jo P; Fraser, John F; Gregory, Shaun D

    2018-01-01

    Right ventricular failure is a common complication associated with rotary left ventricular assist device (LVAD) support. Currently, there is no clinically approved long-term rotary right ventricular assist device (RVAD). Instead, clinicians have implanted a second rotary LVAD as RVAD in biventricular support. To prevent pulmonary hypertension, the RVAD must be operated by either reducing pump speed or banding the outflow graft. These modes differ in hydraulic performance, which may affect the pulmonary valve opening (PVO) and subsequently cause fusion, valvular insufficiency, and thrombus formation. This study aimed to compare PVO with the RVAD operated at reduced speed or with a banded outflow graft. Baseline conditions of systemic normal, hypo, and hypertension with severe biventricular failure were simulated in a mock circulation loop. Biventricular support was provided with two rotary VentrAssist LVADs with cardiac output restored to 5 L/min in banded outflow and reduced speed conditions, and systemic and pulmonary vascular resistances (PVR) were manipulated to determine the range of conditions that allowed PVO without causing left ventricular suction. Finally, RVAD sine wave speed modulation (±550 rpm) strategies (co- and counter-pulsation) were implemented to observe the effect on PVO. For each condition, outflow banding had higher PVR (97 ± 20 dyne/s/cm5 higher) for when the pulmonary valve closed compared to reduced speed. In addition, counter-pulsation demonstrated greater PVO than co-pulsation and constant speed. For the purpose of reducing the risks of pulmonary valve insufficiency, fusion, and thrombotic event, this study recommends a RVAD with a steeper H-Q gradient by banding and further exploration of RVAD speed modulation. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  19. NASA Subsonic Rotary Wing Project-Multidisciplinary Analysis and Technology Development: Overview

    Science.gov (United States)

    Yamauchi, Gloria K.

    2009-01-01

    This slide presentation reviews the objectives of the Multidisciplinary Analysis and Technology Development (MDATD) in the Subsonic Rotary Wing project. The objectives are to integrate technologies and analyses to enable advanced rotorcraft and provide a roadmap to guide Level 1 and 2 research. The MDATD objectives will be met by conducting assessments of advanced technology benefits, developing new or enhanced design tools, and integrating Level 2 discipline technologies to develop and enable system-level analyses and demonstrations.

  20. Effect of rotary instrument associated with different irrigation techniques on removing calcium hydroxide dressing.

    Science.gov (United States)

    Faria, Gisele; Viola, Kennia Scapin; Kuga, Milton Carlos; Garcia, Arturo Javier Aranda; Daher, Vanessa Bossolani; De Pasquali Leonardo, Mário Francisco; Tanomaru-Filho, Mário

    2014-08-01

    Calcium hydroxide [Ca(OH)2 ] residues in root canals may compromise sealing of filling and endodontic treatment success. The aim of this study was to compare the efficacy of using rotary instrument associated with EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation (CNI), in Ca(OH)2 removal from root canal, by means of scanning electron microscopy (SEM) images. Sixty-six human canines were prepared with the Protaper system up to F5 and filled with Ca(OH)2 . After 7 days, Ca(OH)2 was removed with rotary instrument F5 associated with the irrigation techniques used in each group (n = 15): GI (CNI), GII (EndoVac), GIII (EndoActivator) and GIV (PUI). In all groups 15 mL of 2.5% NaOCl and 3 mL of 17% EDTA were used for Ca(OH)2 removal. The Ca(OH)2 residues was evaluated by SEM in the middle and apical third using a system of scores. The results were analyzed by the Kruskal-Wallis and Dunn tests (α = 0.05). None of the techniques completely removed the Ca(OH)2 from root canals. There was no difference between EndoActivator, EndoVac and PUI (P > 0.05), but the three techniques removed more Ca(OH)2 than the CNI (P rotary instrument combined with EndoActivator, EndoVac, and PUI was shown to be more efficient than the rotary instrument combined with the CNI in removing Ca(OH)2 from the root canal. © 2014 Wiley Periodicals, Inc.

  1. Comparison of the Halving of Tablets Prepared with Eccentric and Rotary Tablet Presses

    OpenAIRE

    Sovány, T.; Kása Jr., P.; Pintye-Hódi, K.

    2009-01-01

    The aim of this study was to compare the densification of powder mixtures on eccentric and rotary tablet presses and to establish relationships with the halving properties of the resulting scored tablets. This is an important problem because the recent guidelines of EU require verification of the equal masses of tablet halves. The models of Walker, Heckel, and Kawakita were used to describe the powder densification on the two machines. The calculated parameters revealed that the shorter compr...

  2. Demonstration of a rotary separator for two-phase brine and steam flows. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cerini, D.J.

    1978-01-01

    The application of a two-phase rotary separator for geothermal energy conversion was demonstrated. Laboratory tests were conducted with clean water and steam at Biphase Energy Systems, Inc., Santa Monica, California. Field tests were conducted at the Union Oil Co., Tow No. 1 wellsite near Brawley, California. The system tested consisted of the major components of a total flow rotary separator/turbine conversion system. A nozzle converted the brine wellhead enthalpy to two-phase flow kinetic by impinging the nozzle flow tangentially on the inside of the separator. The flow was therefore subjected to the high centrifugal force field in the separator. This caused the liquid phase to collect as a film on the separator drum with very little energy loss. The steam was allowed to flow radially inward to the central steam discharge. Potable water was obtained by condensing the steam exhaust. The brine collection system converted the liquid film kinetic energy to static pressure head. The system was operated for 116 hours in a high salinity environment (115,000 ppM TDS). The system operated properly with no adverse effects from solids precipitation or scale buildup. The rotary separator produced separate flows of pure liquid and steam of greater than 99.5% quality.

  3. Manual and rotary instrumentation ability to reduce Enterococcus faecalis associated with photodynamic therapy in deciduous molars.

    Science.gov (United States)

    Pinheiro, Sérgio Luiz; Silva, Josianne Neres da; Gonçalves, Rafael Orro; Villalpando, Karina Teixeira

    2014-01-01

    This aim of this study was to assess the ability of manual or rotary instrumentation associated with photodynamic therapy (PDT) to reduce Enterococcus faecalis using three combinations of light/photosensitizers: toluidine blue O/laser, fuchsin/halogen light and fuchsin/LED. Twenty deciduous molars were selected and contaminated with Enterococcus faecalis (McFarland 0.5 scale). Working length determination was performed by visual method. The teeth were randomly divided into two groups: G1 (n=10): manual instrumentation (Kerr-type files) and G2 (n=10): rotary instrumentation (ProTaper system). The bacteria were collected three times using sterile paper cones compatible with the anatomic diameter of the root canal for 30 s before and after instrumentation and after PDT. The samples were diluted in peptone water, seeded on blood agar plates and incubated in an oven at 37 °C for colony-forming units counting. The decrease of E. faecalis counts after instrumentation and after PDT was compared using the Wilcoxon test, t-test and Kruskal Wallis test. A significant reduction of E. faecalis occurred after manual and rotary instrumentation and after PDT using the three combinations of light/photosensitizer (pfaecalis. Fuchsin with halogen light or LED irradiation and toluidine blue O with laser irradiation can be used to reduce E. faecalis in root canals of primary molars. PDT can be used as an adjuvant to conventional endodontic treatment.

  4. Degradation of aldrin and endosulfan in rotary drum and windrow composting.

    Science.gov (United States)

    Ali, Muntjeer; Gani, Khalid M; Kazmi, Absar A; Ahmed, Naseem

    2016-01-01

    Removal efficiencies, kinetics and degradation pathways of aldrin, endosulfan α and endosulfan β in vegetable waste were evaluated during rotary drum and conventional windrow composting. The highest percentage removal of aldrin, endosulfan α and endosulfan β in rotary drum composting was 86.8, 83.3 and 85.3% respectively, whereas in windrow composting, it was 66.6%, 77.7% and 67.2% respectively. The rate constant of degradation of aldrin, endosulfan α and endosulfan β during rotary drum composting ranged from 0.410-0.778, 0.057-0.076 and 0.009-0.061 day(-1) respectively. The pathways of degradation of these pesticides in composting process were proposed. Metabolites dieldrin and 1 hydroxychlorodene formed during composting of aldrin in the vegetable waste indicated the occurrence of epoxidation reaction and oxidation of bridge carbon of aldrin containing the methylene group. Formation of chloroendic acid and chloroendic anhydride during composting of endosulfan containing vegetable waste support the occurrence of endosulfan sulfate and dehydration reaction respectively.

  5. Design and Performance Evaluation of a Rotary Magnetorheological Damper for Unmanned Vehicle Suspension Systems

    Science.gov (United States)

    Lee, Jae-Hoon; Han, Changwan; Ahn, Dongsu; Lee, Jin Kyoo; Park, Sang-Hu; Park, Seonghun

    2013-01-01

    We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers. PMID:23533366

  6. Choice reaction time to movement of eccentric visual targets during concurrent rotary acceleration

    Science.gov (United States)

    Hamerman, J. A.

    1979-01-01

    This study investigates the influence of concurrent rotary acceleration on choice reaction time (RT) to a small, accelerating visual cursor on a cathode-ray tube. Subjects sat in an enclosed rotating device at the center of rotation and observed a 3-mm dot accelerating at different rates across a cathode-ray tube. The dot was viewed at various eccentricities under conditions of visual stimulation alone and with concurrent rotary acceleration. Subjects responded to both vertical and horizontal dot movements. There was a significant inverse relationship between choice RT and level of dot acceleration (p less than .001), and a significant direct relationship between choice RT and eccentricity (p less than .001). There was no significant difference between choice RT to vertical or horizontal dot motion (p greater than .25), and choice RT was not significantly affected by concurrent rotary acceleration (p greater than .10). The results are discussed in terms of the effects of vestibular stimulation on choice RT to visual motion.

  7. Intraoperative discomfort associated with the use of a rotary or reciprocating system: a prospective randomized clinical

    Directory of Open Access Journals (Sweden)

    Aline Cristine Gomes

    2017-05-01

    Full Text Available Objectives The aim of this randomized, controlled, prospective clinical study was to evaluate patients' intraoperative discomfort during root canal preparations in which either multi-file rotary (Mtwo or single-file reciprocating (Reciproc systems were used. Materials and Methods Fifty-five adult patients, aged between 25 and 69 years old, with irreversible pulpitis or pulp necrosis participated in this study. Either the mesiobuccal or the distobuccal canals for maxillary molars and either the mesiobuccal or the mesiolingual canals for mandibular molars were randomly chosen to be instrumented with Mtwo multi-file rotary or Reciproc single-file reciprocating systems. Immediately after each canal instrumentation under anesthesia, patient discomfort was assessed using a 1 - 10 visual analog scale (VAS, ranging from ‘least possible discomfort’ (1 to ‘greatest possible discomfort’ (10. The Wilcoxon signed-rank test was used to determine significant differences at p< 0.05. Results Little intraoperative discomfort was found in all cases. No statistically significant differences in intraoperative discomfort between the 2 systems were found (p = 0.660. Conclusions Root canal preparation with multi-file rotary or single-file reciprocating systems had similar and minimal effects on patients' intraoperative discomfort.

  8. Design and performance evaluation of a rotary magnetorheological damper for unmanned vehicle suspension systems.

    Science.gov (United States)

    Lee, Jae-Hoon; Han, Changwan; Ahn, Dongsu; Lee, Jin Kyoo; Park, Sang-Hu; Park, Seonghun

    2013-01-01

    We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers.

  9. Design and Performance Evaluation of a Rotary Magnetorheological Damper for Unmanned Vehicle Suspension Systems

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Lee

    2013-01-01

    Full Text Available We designed and validated a rotary magnetorheological (MR damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD, and a high magnetic field intensity (MFI for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers.

  10. Common evolutionary origin for the rotor domain of rotary ATPases and flagellar protein export apparatus.

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kishikawa

    Full Text Available The V1- and F1- rotary ATPases contain a rotor that rotates against a catalytic A3B3 or α3β3 stator. The rotor F(1-γ or V1-DF is composed of both anti-parallel coiled coil and globular-loop parts. The bacterial flagellar type III export apparatus contains a V1/F1-like ATPase ring structure composed of FliI6 homo-hexamer and FliJ which adopts an anti-parallel coiled coil structure without the globular-loop part. Here we report that FliJ of Salmonella enterica serovar Typhimurium shows a rotor like function in Thermus thermophilus A3B3 based on both biochemical and structural analysis. Single molecular analysis indicates that an anti-parallel coiled-coil structure protein (FliJ structure protein functions as a rotor in A3B3. A rotary ATPase possessing an F1-γ-like protein generated by fusion of the D and F subunits of V1 rotates, suggesting F(1-γ could be the result of a fusion of the genes encoding two separate rotor subunits. Together with sequence comparison among the globular part proteins, the data strongly suggest that the rotor domains of the rotary ATPases and the flagellar export apparatus share a common evolutionary origin.

  11. Application of Adaptive Starling-Like Controller to Total Artificial Heart Using Dual Rotary Blood Pumps.

    Science.gov (United States)

    Ng, Boon C; Smith, Peter A; Nestler, Frank; Timms, Daniel; Cohn, William E; Lim, Einly

    2017-03-01

    The successful clinical applicability of rotary left ventricular assist devices (LVADs) has led to research interest in devising a total artificial heart (TAH) using two rotary blood pumps (RBPs). The major challenge when using two separately controlled LVADs for TAH support is the difficulty in maintaining the balance between pulmonary and systemic blood flows. In this study, a starling-like controller (SLC) hybridized with an adaptive mechanism was developed for a dual rotary LVAD TAH. The incorporation of the adaptive mechanism was intended not only to minimize the risk of pulmonary congestion and atrial suction but also to match cardiac demand. A comparative assessment was performed between the proposed adaptive starling-like controller (A-SLC) and a conventional SLC as well as a constant speed controller. The performance of all controllers was evaluated by subjecting them to three simulated scenarios [rest, exercise, head up tilt (HUT)] using a mock circulation loop. The overall results showed that A-SLC was superior in matching pump flow to cardiac demand without causing hemodynamic instabilities. In contrast, improper flow regulation by the SLC resulted in pulmonary congestion during exercise. From resting supine to HUT, overpumping of the RBPs at fixed speed (FS) caused atrial suction, whereas implementation of SLC resulted in insufficient flow. The comparative study signified the potential of the proposed A-SLC for future TAH implementation particularly among outpatients, who are susceptible to variety of clinical scenarios.

  12. Metallurgical characterization of a new nickel-titanium wire for rotary endodontic instruments.

    Science.gov (United States)

    Alapati, Satish B; Brantley, William A; Iijima, Masahiro; Clark, William A T; Kovarik, Libor; Buie, Caesar; Liu, Jie; Ben Johnson, William

    2009-11-01

    A novel thermomechanical processing procedure has been developed that yields a superelastic (SE) nickel-titanium (NiTi) wire (M-Wire) that laboratory testing shows has improved mechanical properties compared with conventional SE austenitic NiTi wires used for manufacture of rotary instruments. The objective of this study was to determine the origin of the improved mechanical properties. Specimens from 2 batches of M-Wire prepared under different processing conditions and from 1 batch of standard-processed SE wire for rotary instruments were examined by scanning transmission electron microscopy, temperature-modulated differential scanning calorimetry, micro-x-ray diffraction, and scanning electron microscopy with x-ray energy-dispersive spectrometric analyses. The processing for M-Wire yields a microstructure containing martensite, that the proportions of NiTi phases depend on processing conditions, and that the microstructure exhibits pronounced evidence of alloy strengthening. The presence of Ti(2)Ni precipitates in both microstructures indicates that M-Wire and the conventional SE wire for rotary instruments are titanium-rich.

  13. An in vitro assessment of the physical properties of novel Hyflex nickel-titanium rotary instruments.

    Science.gov (United States)

    Peters, O A; Gluskin, A K; Weiss, R A; Han, J T

    2012-11-01

    To determine several properties including torsional and fatigue limits, as well as torque during canal preparation, of Hyflex, a rotary instrument manufactured from so-called controlled memory nickel-titanium alloy. The instruments were tested in vitro using a special torque bench that permits both stationary torque tests according to ISO3630-1 and fatigue limit determination, as well as measurement of torque (in Ncm) and apical force (in N) during canal preparation. Fatigue limit (in numbers of cycles to failure) was determined in a 90°, 5 mm radius block-and-rod assembly. Simulated canals in plastic blocks were prepared using both a manufacturer-recommended single-length technique as well as a generic crown-down approach. anova with Bonferroni post hoc procedures was used for statistical analysis. Torque at failure ranged from 0.47 to 1.38 Ncm, with significant differences between instrument sizes (P Hyflex rotary instruments are bendable and flexible and have similar torsional resistance compared to instruments made of conventional NiTi. Fatigue resistance is much higher, and torque during preparation is less, compared to other rotary instruments tested previously under similar conditions. © 2012 International Endodontic Journal.

  14. Rotary triboelectric nanogenerator based on a hybridized mechanism for harvesting wind energy.

    Science.gov (United States)

    Xie, Yannan; Wang, Sihong; Lin, Long; Jing, Qingshen; Lin, Zong-Hong; Niu, Simiao; Wu, Zhengyun; Wang, Zhong Lin

    2013-08-27

    Harvesting mechanical energy is becoming increasingly important for its availability and abundance in our living environment. Triboelectric nanogenerator (TENG) is a simple, cost-effective, and highly efficient approach for generating electricity from mechanical energies in a wide range of forms. Here, we developed a TENG designed for harvesting tiny-scale wind energy available in our normal living environment using conventional materials. The energy harvester is based on a rotary driven mechanical deformation of multiple plate-based TENGs. The operation mechanism is a hybridization of the contact-sliding-separation-contact processes by using the triboelectrification and electrostatic induction effects. With the introduction of polymer nanowires on surfaces, the rotary TENG delivers an open-circuit voltage of 250 V and a short-circuit current of 0.25 mA, corresponding to a maximum power density of ~39 W/m(2) at a wind speed of ~15 m/s, which is capable of directly driving hundreds of electronic devices such as commercial light-emitting diodes (LEDs), or rapidly charging capacitors. The rotary TENG was also applied as a self-powered sensor for measuring wind speed. This work represents a significant progress in the practical application of the TENG and its great potential in the future wind power technology. This technology can also be extended for harvesting energy from ocean current, making nanotechnology reaching our daily life a possibility in the near future.

  15. Numerical study on cavitation inception in the rotary valve of the hydraulic power steering system

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Gwang Nyeon; Cho, Myung Hwan; Yoo, Jung Yul [Seoul National Univ., Seoul (Korea, Republic of); Park, Sun Hong [MANDO Corporation, Seoul (Korea, Republic of)

    2009-07-01

    The rotary valve directs the power steering oil to either side of a power piston and relieves the driver of the effort to turn the wheel, when a driver begins to operate the vehicle. It is well known that the hiss noise occurring at that moment is caused mainly by cavitation of the oil inside the rotary valve. In this paper, two types of rotary valve (round and straight type) have been analyzed numerically using three-dimensional cavitation model embedded in the commercial code, FLUENT v6.2 and the results have been compared with the measured hiss noise level in a semi-anechoic chamber. The volume of the oil vapor generated from cavitation was larger in Round type valve which has a convex shape of the sleeve grooves than in Straight type valve which has a rectangular shape of the sleeve grooves. The hiss noise level of Round type valve was higher than that of Straight type valve as well. These results mean that the hiss noise can be reduced by the change of the shape of the grooves.

  16. Postoperative Pain After Root Canal Preparation with Hand and Rotary Files in Primary Molar Teeth.

    Science.gov (United States)

    Topçuoğlu, Gamze; Topçuoğlu, Hüseyin Sinan; Delikan, Ebru; Aydınbelge, Mustafa; Dogan, Salih

    2017-05-15

    The purpose of this study was to evaluate the intensity and duration of postoperative pain after root canal preparation of primary maxillary molar teeth using two preparation techniques. A total of 110 patients requiring pulpectomy for asymptomatic primary molar teeth with non-vital pulps were included in the study. The patients were randomly assigned to two groups of 55 patients each, according to the canal preparation method used. In Group one, teeth were prepared up to size 35 with hand files. In Group two, teeth were prepared up to size 35 with Revo-S rotary instruments. Following canal preparation, teeth were obturated with zinc-oxide eugenol paste and then permanently restored. The presence of postoperative pain was assessed after six, 12, 24, 48, and 72 hours and after one week, using a four-point pain-intensity scale. Except for those assessed after 72 hours and one week, patients who had their teeth prepared with hand files reported more intense postoperative pain than those who had their teeth prepared with Revo-S rotary files (Ppulpectomy in primary maxillary molar teeth compared to the rotary system.

  17. Movement kinematics and cyclic fatigue of NiTi rotary instruments: a systematic review.

    Science.gov (United States)

    Ferreira, F; Adeodato, C; Barbosa, I; Aboud, L; Scelza, P; Zaccaro Scelza, M

    2017-02-01

    The aim of this review was to provide a detailed analysis of the literature concerning the correlation between different movement kinematics and the cyclic fatigue resistance of NiTi rotary endodontic instruments. From June 2014 to August 2015, four independent reviewers comprehensively and systematically searched the Medline (PubMed), EMBASE, Web of Science, Scopus and Google Scholar databases for works published since January 2005, using the following search terms: endodontics; nickel-titanium rotary files; continuous rotation; reciprocating motion; cyclic fatigue. In addition to the electronic searches, manual searches were performed to include articles listed in the reference sections of high-impact published articles that were not indexed in the databases. Laboratory studies in English language were considered for this review. The electronic and manual searches resulted in identification of 75 articles. Based on the inclusion criteria, 32 articles were selected for analysis of full-text copies. Specific analysis was then made of 20 articles that described the effects of reciprocating and continuous movements on cyclic fatigue of the instruments. A wide range of testing conditions and methodologies have been used to compare the cyclic fatigue resistance of rotary endodontic instruments. Most studies report that reciprocating motion improves the fatigue resistance of endodontic instruments, compared to continuous rotation, independent of other variables such as the speed of rotation, the angle or radius of curvature of simulated canals, geometry and taper, or the surface characteristics of the NiTi instruments. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  18. Quantitative evaluation of apical extrusion of intracanal bacteria using rotary ProTaper, K3XF, twisted and hand K-file system: An ex vivo study

    Directory of Open Access Journals (Sweden)

    Priyanka Ghogre

    2015-01-01

    Conclusions: Both the rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen. K3XF file system showed least bacterial extrusion amongst all instrumentation groups.

  19. The coupled chemomechanics of the F(1)-ATPase molecular motor.

    Science.gov (United States)

    Xu, Lizhong

    2008-11-01

    The enzyme F(1)-ATPase is a rotary nanomotor in which the central gamma subunit rotates inside the cavity made of alpha(3)beta(3) subunits. The experiments showed that the rotation proceeds in steps of 120 degrees and each 120 degrees step consists of 80 degrees and 40 degrees substeps. Here the Author proposes a stochastic wave mechanics of the F(1)-ATPase motor and combines it with the structure-based kinetics of the F(1)-ATPase to form a chemomechanic coupled model. The model can reproduce quantitatively and explain the experimental observations about the F(1) motor. Using the model, several rate-limited situations about gamma subunit rotation are proposed, the effects of the friction and the load on the substeps are investigated and the chemomechanic coupled time during ATP hydrolysis cycle is determined.

  20. Modeling the Mixing of Components in a Rotary Kiln While Burning Municipal Waste to Ensure Rational Use of Energy

    Directory of Open Access Journals (Sweden)

    Krot O.P.

    2017-08-01

    Full Text Available In Ukraine municipal waste is collected and delivered to a landfill. Municipal waste can be used as fuel to generate additional heat and electricity. The primary advantages of incineration are that waste volumes are reduced by an estimated, and the need for land and landfill space is greatly reduced. The plant has been designed by North–East Scientific Center using a thermocatalytic waste gas purification system with highly efficient dioxins reduction and heat energy recovery system. The technology of waste neutralization includes: a rotary kiln, an afterburner chamber, a new catalytic technologies for the treatment, a heat exchanger for heating combustion air, supply of alkali solution into the gas-escape channel, a carbon fiber adsorption filter. The organization of the right process of waste mixing in the rotary kiln allows increasing the efficiency of combustion, to equalize the combustion temperatures of the components of the waste and the completeness of the burning out of hazardous substances, which reduces the risk of their getting into the ash. The goal of the research is to build an analytical mathematical model of mixing of components in a rotary kiln. The model is based on the mathematical apparatus of Markov chains. The model allows to determine the concentration of the key component in any elementary volume of material circulating in the rotary kiln at any time and to calculate the statistical characteristics of the homogeneity of the mixture. The model will be used to research new designs of the equipment with rotary kilns.

  1. Comparative evaluation of apically extruded debris during root canal preparation using ProTaper™, Hyflex™ and Waveone™ rotary systems.

    Science.gov (United States)

    Surakanti, Jayaprada Reddy; Venkata, Ravi Chandra Polavarapu; Vemisetty, Hari Kumar; Dandolu, Ram Kiran; Jaya, Nagendra Krishna Muppalla; Thota, Shirisha

    2014-03-01

    Extrusion of any debris during endodontic treatment may potentially cause post-operative complications such as flare-ups. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems. In this study, 60 human mandibular first premolars were randomly assigned to 3 groups (n = 20 teeth/group). The root canals were instrumented according to the manufacturers' instructions using the Reciprocating single-file system WaveOne™ (Dentsply Maillefer, Ballaigues, Switzerland) and full-sequence rotary Hyflex CM™ (Coltene Whaledent, Allstetten, Switzerland) and ProTaper™ (Dentsply Maillefer, Ballaigues, Switzerland) instruments. The canals were then irrigated using bidistilled water. The debris that was extruded apically was collected in preweighed eppendorf tubes and assessed with an electronic balance and compared. The debris extrusion was compared and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. The WaveOne™ and ProTaper™ rotary instruments produced significantly more debris compared with Hyflex CM™ rotary instruments (P < 0.05). Under the conditions of this study, all systems that were used resulted in extrusion of apical debris. Full-sequence rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems.

  2. In Vitro Comparison of Instrumentation Time and Cleaning Capacity between Rotary and Manual Preparation Techniques in Primary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Z. Bahrololoomi

    2007-06-01

    Full Text Available Objective: The aim of this study was to evaluate and compare the cleaning ability and instrumentation time of manual and rotary methods used for preparation of primary an-terior teeth.Materials and Methods: Forty-four primary anterior teeth were used in this experi-mental study. Access cavities were prepared and India ink was injected into the canals. The samples were divided into three groups according to the instrument and preparation technique. In group I the root canals were manually instrumented with K-files. Rotary Flexmaster instruments were used for canal preparation in Group II, and the samples in Group III (control were not instrumented. After canal preparation, the teeth were cleared with methyl salicilate and the removal of India ink was measured in the cervical, middle and apical thirds. The incidence of file breakage and instrumentation time was recorded in the three study groups. Statistical analysis was performed using Mann-Whitney and t-tests.Results: There was no significant difference in cleaning capacity between the two tech-niques, but a significant difference was found between the experimental and control groups. Working time was significantly shorter when using the rotary system. No file fracture was observed during the study period.Conclusion: Regarding the shorter working time for rotary instrumentation and the similar cleaning ability of the two techniques, the application of the rotary system is suggested for preparation of decidious root canals during pulpectomy.

  3. Cone Beam Computed Tomography Evaluation of Hand Nickel-Titanium K-Files and Rotary System in Primary Teeth.

    Science.gov (United States)

    Radhika, Etta; Reddy, E Rajendra; Rani, S Thabitha; Kumar, Labishetty Vinay; Manjula, M; Mohan, Tulluru Ajay

    2017-07-15

    The purpose of this study was to compare canal transportation, centering ability, and removed dentin thickness (RDT) using hand nickel-titanium (NiTi) K-flex files and rotary systems in primary molars and using cone beam computed tomography (CBCT). This study was conducted on 20 primary maxillary and 20 primary mandibular molars, which were randomly divided into two groups to be instrumented with hand NiTi K-flex files and a rotary system. Pre- and post-instrumentation slices were taken at three predetermined levels using CBCT to evaluate all the parameters by using Digital Imaging Communications in Medicine (DICOM) software. The results were statistically evaluated. Rotary instruments caused significantly less canal transportation and showed more centering ability than hand NiTi instruments at all levels and in all directions, except at the cervical level in the mesiodistal direction, where the hand group showed significantly superior results. The hand NiTi K-flex files removed significantly more dentin than rotary instrumentation at all levels and in all directions, except at the apical level in the buccodistal direction, where no significant difference between the two groups was observed. Rotary files showed less canal transportation, more conservation of tooth structure, and superior centering ability compared to hand nickel-titanium K-flex files.

  4. Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals.

    Science.gov (United States)

    Martinho, Frederico C; Freitas, Lilian F; Nascimento, Gustavo G; Fernandes, Aleteia M; Leite, Fabio R M; Gomes, Ana P M; Camões, Izabel C G

    2015-07-01

    This clinical study was conducted to compare the effectiveness of single-file reciprocating systems and rotary systems in removing endotoxins and cultivable bacteria in endodontic retreatment. Thirty endodontically treated teeth with post-treatment apical periodontitis were selected. The specimens were divided into three groups according to the system used: WaveOne (n = 10), Reciproc instrument (n = 10), and ProTaper Universal Retreatment system (n = 10). Samples were collected before and after chemomechanical preparation. The irrigation was performed by using 2.5% sodium hypochlorite. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial colony-forming unit counts. At baseline, endotoxins and cultivable bacteria were recovered from 100% of the root canal samples in a median value of 5.84 EU/mL and 4.98 × 10(3) CFU/mL, respectively. After CMP, no differences were found in the median percentage values of endotoxin reduction achieved with reciprocating systems-WaveOne [94.11%] and Reciproc [93.29%] and with rotary systems-ProTaper [94.98%] (P > 0.05). Both single-file reciprocating systems [WaveOne (98.27%) and Reciproc (99.54%)] and rotary system [ProTaper (98.73%)] were effective in reducing bacterial load (P > 0.05). Moreover, no differences were found among the systems tested. The Reciproc and WaveOne reciprocating systems were as effective as the ProTaper system for removal of endotoxins and bacteria in endodontic retreatment. All systems tested were effective to remove cultivable bacteria and endotoxin in endodontic retreatment. As no differences among systems were observed, it is possible to suggest that clinicians should choose the preferred technique to perform endodontic.

  5. Variable speed rotary compressor and adjustable speed drive efficiencies measured in the laboratory

    Science.gov (United States)

    Miller, W. A.

    Two state-of-the-art variable-speed rotary compressors, of nominal one ton cooling capacity, were instrumented and tested in the laboratory. Both compressors were identical except for their respective variable-speed drive systems (i.e., motor and inverter). One compressor had an inverter driven induction motor (IDIM) drive, and the other had a permanent magnet electronically commutated motor drive (PM-ECM). The laboratory study evaluated the compressor's efficiency under representative variable-speed conditions. Testing was conducted as a function of compressor drive frequency and of refrigerant condensing and evaporating conditions. Saturated refrigerant conditions, inlet superheat, and subcooling were controlled using a secondary refrigerant calorimeter. Spectrum analysis was conducted on the current input to one phase of the three-phase drive systems to measure motor speed and characterize harmonic content of the inverters. An optimal volt per Hz ratio was determined at 120-, 90-, 60-, and 30-Hz drive frequencies and at different load conditions for the rotary with induction motor as driven by a PWM inverter and also by a motor generator set (ideal induction motor drive). Variation of voltage input to the compressor had the largest effect at the lowest drive frequency (30Hz). A 5 percent variation about the optimal voltage at 30 Hz frequency caused a roughly 5 percent drop in compressor isentropic efficiency. Calorimeter data were used to develop modulating compressor and drive system performance maps. Performances of the two compressors were compared and the rotary with PM-ECM drive showed better efficiency trends at 30-Hz drive frequency. Above the 30-Hz drive frequency no clear advantage was observed for the PM-ECM vs the IDIM, possibly due to oversizing of the PM-ECM inverter.

  6. THE DEVELOPMENT OF INNOVATIVE DESIGN OF THE CONICAL ROTARY- AND FILM APPARATUS

    Directory of Open Access Journals (Sweden)

    S. Altayuly

    2015-01-01

    Full Text Available Summary. A new design of the conical rotary- and film apparatus for carrying out the process of dripping phosphatidic emulsion of vegetable oils, which are used in the oil industry and other industries that use the evaporation of moisture from the high-heat-labile concentrates. As a result of experimental studies we achieved the following. The conical rotary film apparatus perforated inner cavity of the rotor is divided into a supply and distribution of the original product and vapor removal zone with a barrier that hosts spheroconical insert shapes with reverse bend the conical portion, the top of which is directed towards the delivery of the original product. In the area of supply and distribution of starting material the perforations of the rotor have a slit shape. In the cavity of the rotor curved blades are mounted whose generators have the form of the curve. This curve is obtained by approximation of the polyline. The nozzle for inputting of starting mate-rial having tangentially formed holes on both ends is rotatably mounted in the central part of the conical body along its axis, one end of which is placed in the interior of the perforated rotor in the feeding zone and the distribution of the starting material, and the other one is placed in the chamber for a starting material, which is connected in series with the heater and the feeding pump for starting material. Scientific novelty of the innovative design of the device is to reduce the amplitude of the oscillation of the film rotary apparatus by re-ducing friction of particles suspension on the rotor blades, causing higher dynamic loads, ensure even distribution of starting material on the inner surface of the housing, as well as reduction of energy consumption.

  7. Autonomous Mower vs. Rotary Mower: Effects on Turf Quality and Weed Control in Tall Fescue Lawn

    Directory of Open Access Journals (Sweden)

    Michel Pirchio

    2018-02-01

    Full Text Available Autonomous mowers are battery-powered machines designed for lawn mowing that require very low human labour. Autonomous mowers can increase turf quality and reduce local noise and pollution compared with gasoline-powered rotary mowers. However, very little is known about the effects of autonomous mowing on encroaching weeds. The aim of this research was to compare the effects of an autonomous mower and an ordinary gasoline-powered mower on weed development in an artificially infested tall fescue (Festuca arundinacea Schreb. turf with different nitrogen (N rates. A three-way factor experimental design with three replications was adopted. Factor A consisted of three N rates (0, 75, and 150 kg ha−1, factor B consisted of two mowing systems (autonomous mower vs. walk-behind gasoline rotary mower equipped for mulching, and factor C which consisted of four different transplanted weed species: (a Bellis perennis L., (b Trifolium repens L.; (c Trifolium subterraneum L.; and (d Lotus corniculatus L. Of these, B. perennis is a rosette-type plant, while the other three species are creeping-type plants. The interaction between mowing system and transplanted weed species showed that the four transplanted weed species were larger when mowed by the autonomous mower than by the rotary mower. The autonomous mower yielded larger weeds probably because the constant mowing height caused the creeping weed species to grow sideways, since the turfgrass offered no competition for light. N fertilization increased turf quality and mowing quality, and also reduced spontaneous weed infestation. Autonomous mowing increased turf quality, mowing quality, but also the percentage of spontaneous weed cover.

  8. Integrated Status and Effectiveness Monitoring Program - Entiat River Snorkel Surveys and Rotary Screw Trap, 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Nelle, R.D.

    2008-01-01

    The USFWS Mid-Columbia River Fishery Resource Office conducted snorkel surveys at 24 sites during the summer and fall periods of 2006 survey periods as part of the Integrated Status and Effectiveness Monitoring Program in the Entiat River. A total of 37,938 fish from 15 species/genera and an unknown category were enumerated. Chinook salmon were the overall most common fish observed and comprised 15% of fish enumerated followed by rainbow trout (10%) and mountain whitefish (7%). Day surveys were conducted during the summer period 2007 (August), while night surveys were conducted during the fall 2007 (October) surveys. The USFWS Mid-Columbia River Fishery Resource Office (MCFRO) operated two rotary screw traps on the Entiat River as part of the Integrated Status and Effectiveness Monitoring Program (ISEMP) program from August through November of 2007. Along with the smolt traps, juvenile emigrants were also captured at remote locations throughout the Entiat watershed and its major tributary, the Mad River. A total of 999 wild Oncorhynchus mykiss and 5,107 wild run O. tshawytscha were PIT tagged during the study period. Rotary screw trap efficiencies averaged 22.3% for juvenile O. tshawytscha and 9.0% for juvenile O. mykiss. Rotary screw traps operated 7 days a week and remote capture operations were conducted when flow and temperature regimes permitted. This is third annual progress report to Bonneville Power Administration for the snorkel surveys conducted in the Entiat River as related to long-term effectiveness monitoring of restoration programs in this watershed. The objective of this study is to monitor the fish habitat utilization of planned in-stream restoration efforts in the Entiat River by conducting pre- and post-construction snorkel surveys at selected treatment and control sites.

  9. Microbiological assessment of root canals following use of rotary and manual instruments in primary molars.

    Science.gov (United States)

    Subramaniam, Priya; Tabrez, T A; Babu, K L Girish

    2013-01-01

    To assess the microflora of root canals in primary molars following use of rotary NiTi files and conventional hand NiTi and stainless steel files. This randomized clinical trial consisted of a total of 60 first and second primary molars requiring root canal treatment, who were selected from children aged 5-9 years. Based on type of root canal instrumentation, the teeth were randomly assigned to three groups of twenty teeth each; Group A: Rotary NiTi files, Group B: Hand NiTi files and Group C: Hand stainless steel files. Following administration of local anesthesia, isolation with rubber dam was carried out. For the purpose of instrumentation and sampling, the palatal canal of maxillary molars and the distal canal of mandibular molars were selected. Prior to sampling, the orifices of other canals in these teeth were sealed, so as to prevent any contamination. Instrumentation was carried out in each group using respective instruments along with intermittent saline irrigation. Root canal samples were obtained both before and after instrumentation, using sterile absorbent paper points and transferred to a sterile vial with transport fluid. Serial dilutions were prepared and cultured on suitable agar media. Both aerobic and anaerobic microbial counts were made. Data obtained was subjected to statistical analysis using Wilcoxon signed rank test and one-way Analysis of variance. In all three groups, there was a significant reduction in both aerobic and anaerobic mean microbial count following root canal instrumentation. (p < 0.001). Rotary NiTi files were as efficient as conventional hand instruments in significantly reducing the root canal microflora.

  10. Principle and experimental verification of novel dual driving face rotary ultrasonic motor

    Science.gov (United States)

    Lu, Xiaolong; Hu, Junhui; Yang, Lin; Zhao, Chunsheng

    2013-09-01

    Existing rotary ultrasonic motors operating in extreme environments cannot meet the requirements of good environmental adaptability and compact structure at same time, and existing ultrasonic motors with Langevin transducers show better environmental adaptability, but size of these motors are usually big due to the radial arrangement of the Langevin transducers. A novel dual driving face rotary ultrasonic motor is proposed, and its working principle is experimentally verified. The working principle of the novel ultrasonic motor is firstly proposed. The 5th in-plane flexural vibration travelling wave, excited by the Langevin transducers around the stator ring, is used to drive the rotors. Then the finite element method is used in the determination of dimensions of the prototype motor, and the confirmation of its working principle. After that, a laser Doppler vibrometer system is used for measuring the resonance frequency and vibration amplitude of the stator. At last, output characteristics of the prototype motor are measured, environmental adaptability is tested and performance for driving a metal ball is also investigated. At room temperature and 200 V(zero to peak) driving voltage, the motor’s no-load speed is 80 r/min, the stalling torque is 0.35 N·m and the maximum output power is 0.85 W. The response time of this motor is 0.96 ms at the room temperature, and it decreases or increases little in cold environment. A metal ball driven by the motor can rotate at 210 r/min with the driving voltage 300 V(zero to peak). Results indicate that the prototype motor has a large output torque and good environmental adaptability. A rotary ultrasonic motor owning compact structure and good environmental adaptability is proposed, and lays the foundations of ultrasonic motors’ applications in extreme environments.

  11. Comparing Rotary Bend Wire Fatigue Test Methods at Different Test Speeds

    Science.gov (United States)

    Weaver, Jason D.; Gutierrez, Erick J.

    2015-12-01

    Given its relatively simple setup and ability to produce results quickly, rotary bend fatigue testing is becoming commonplace in the medical device industry and is the subject of a new standard test method ASTM E2948-14. Although some research has been conducted to determine if results differ for different rotary bend fatigue test setups or test speeds, these parameters have not been extensively studied together. In this work, we investigate the effects of these two parameters on the fatigue life of three commonly used medical device alloys (ASTM F2063 nitinol, ASTM F138 stainless steel, and ASTM F1058 cobalt chromium). Results with three different rotary bend fatigue test setups revealed no difference in fatigue life among those setups. Increasing test speed, however, between 100 and 35,000 RPM led to an increased fatigue life for all three alloys studied (average number of cycles to fracture increased between 2.0 and 5.1 times between slowest and fastest test speed). Supplemental uniaxial tension tests of stainless steel wire at varying strain rates showed a strain rate dependence in the mechanical response which could in part explain the increased fatigue life at faster test speeds. How exactly strain rate dependence might affect the fatigue properties of different alloys at different alternating strain values requires further study. Given the difference in loading rates between benchtop fatigue tests and in vivo deformations, the potential for strain rate dependence should be considered when designing durability tests for medical devices and in extrapolating results of those tests to in vivo performance.

  12. Evidence for Reduced Fatigue Resistance of Contemporary Rotary Instruments Exposed to Body Temperature.

    Science.gov (United States)

    de Vasconcelos, Rafaela Andrade; Murphy, Sarah; Carvalho, Claudio Antonio Talge; Govindjee, Rajiv G; Govindjee, Sanjay; Peters, Ove A

    2016-05-01

    The purpose of this study was to evaluate the effect of 2 different temperatures (20°C and 37°C) on the cyclic fatigue life of rotary instruments and correlate the results with martensitic transformation temperatures. Contemporary nickel-titanium rotary instruments (n = 20 each and tip size #25, including Hyflex CM [Coltene, Cuyahoga Falls, OH], TRUShape [Dentsply Tulsa Dental Specialties, Tulsa, OK], Vortex Blue [Dentsply Tulsa Dental Specialties], and ProTaper Universal [Dentsply Tulsa Dental Specialties]) were tested for cyclic fatigue at room temperature (20°C ± 1°C) and at body temperature (37°C ± 1°C). Instruments were rotated until fracture occurred in a simulated canal with an angle curvature of about 60° and a radius curvature of 3 mm; the center of the curvature was 4.5 mm from the instrument tip. The number of cycles to fracture was measured. Phase transformation temperatures for 2 instruments of each brand were analyzed by differential scanning calorimetry. Data were analyzed using the t test and 1-way analysis of variance with the significance level set at 0.05. For the tested size and at 20°C, Hyflex CM showed the highest resistance to fracture; no significant difference was found between TRUShape and Vortex Blue, whereas ProTaper Universal showed the lowest resistance to fracture. At 37°C, resistance to fatigue fracture was significantly reduced, up to 85%, for the tested instruments (P Hyflex CM and Vortex Blue had similar and higher fatigue resistance compared with TRUShape and ProTaper Universal. Under the conditions of this study, using a novel testing design, immersion in water at simulated body temperature was associated with a marked decrease in the fatigue life of all rotary instruments tested. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Cleaning Effectiveness of Three NiTi Rotary Instruments: A Focus on Biomaterial Properties

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2015-02-01

    Full Text Available Nickel-titanium (NiTi instruments are commonly used for shaping the root canal system in endodontic practice. They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered root canal form with a reduced tendency to canal transportation and instrument fracture. HyFlex CM instruments are new NiTi rotary instruments with shape memory produced by an innovative methodology (patent pending that uses a complex heating and cooling treatment that controls the material’s memory. The aim of the present study was to compare the cleaning efficacy of two conventional (Mtwo, Revo-S Ni-Ti rotary instruments with HyFlex CM. 30 single-rooted freshly extracted teeth were divided into three groups. Root canals were shaped with three NiTi instruments (Mtwo, Revo-S and HyFlex CM using 5.25% NaOCl and 17% EDTA solutions. Specimens were fractured longitudinally and prepared for SEM analysis at standard magnification of 1000×. The presence/absence of debris smear layer and the presence/absence of smear layer at coronal, middle, and apical third of each canal were evaluated using a 5-step scale for scores. Numeric data were analyzed using Kruskall-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P < 0.05. This study revealed significant differences among the various groups. Despite some minor differences, all instruments removed smear layer and debris produced during instrumentation. HyFlex CM seem to be not so effective in promoting cleanliness of root canal walls and in removing smear layer from dentine if compared to Mtwo and Revo-S.

  14. Cleaning Effectiveness of Three NiTi Rotary Instruments: A Focus on Biomaterial Properties.

    Science.gov (United States)

    Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Beltrami, Riccardo; Bianchi, Stefano

    2015-02-16

    Nickel-titanium (NiTi) instruments are commonly used for shaping the root canal system in endodontic practice. They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered root canal form with a reduced tendency to canal transportation and instrument fracture. HyFlex CM instruments are new NiTi rotary instruments with shape memory produced by an innovative methodology (patent pending) that uses a complex heating and cooling treatment that controls the material's memory. The aim of the present study was to compare the cleaning efficacy of two conventional (Mtwo, Revo-S) Ni-Ti rotary instruments with HyFlex CM. 30 single-rooted freshly extracted teeth were divided into three groups. Root canals were shaped with three NiTi instruments (Mtwo, Revo-S and HyFlex CM) using 5.25% NaOCl and 17% EDTA solutions. Specimens were fractured longitudinally and prepared for SEM analysis at standard magnification of 1000×. The presence/absence of debris smear layer and the presence/absence of smear layer at coronal, middle, and apical third of each canal were evaluated using a 5-step scale for scores. Numeric data were analyzed using Kruskall-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P HyFlex CM seem to be not so effective in promoting cleanliness of root canal walls and in removing smear layer from dentine if compared to Mtwo and Revo-S.

  15. Comparative Evaluation of the Efficiency of Manual and Rotary Gutta-percha Removal Techniques.

    Science.gov (United States)

    Colaco, Ashwini S; Pai, Vivekananda A R

    2015-11-01

    This study aimed to evaluate the efficiency of 2 manual and 2 rotary gutta-percha (GP) removal techniques in terms of both the total operating time and GP remnants left in the canal. GP was removed with manual techniques using H-files and xylene (H + X) and H-files and System B (H + SB) (SybronEndo, Orange, CA) and with rotary techniques using the ProTaper Univeral Retreatment (PTUR) (Dentsply Maillefer, Ballaigues, Switzerland) and D-RaCe Retreatment (D-RR) (FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems. The total operating time was evaluated as the time taken to reach the working length and completely remove GP until no radiopaque remnants were observed in the final radiograph. Any GP remnants left in the canal were evaluated in terms of percentage in the whole canal. Rotary techniques were significantly faster and left lesser GP remnants than manual techniques (P techniques, the D-RR system was significantly faster than the PTUR system (P .05). In manual techniques, H + X was significantly faster and left lesser GP remnants than H + SB (P techniques were more efficient than manual techniques in GP removal. Overall, the D-RaCe Retreatment system was most efficient, whereas manual use of H-files with System B was least efficient. However, because all the techniques showed GP remnants in the canal and radiographs failed to show these remnants, additional measures would be required to ensure complete GP removal and check for cleaner canals during endodontic retreatment. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Computed tomography evaluation of rotary systems on the root canal transportation and centering ability

    Energy Technology Data Exchange (ETDEWEB)

    Pagliosa, Andre; Raucci-Neto, Walter; Silva-Souza, Yara Teresinha Correa; Alfredo, Edson, E-mail: ysousa@unaerp.br [Universidade de Ribeirao Preto (UNAERP), SP (Brazil). Fac. de Odontologia; Sousa-Neto, Manoel Damiao; Versiani, Marco Aurelio [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Fac. de Odoentologia

    2015-03-01

    The endodontic preparation of curved and narrow root canals is challenging, with a tendency for the prepared canal to deviate away from its natural axis. The aim of this study was to evaluate, by cone-beam computed tomography, the transportation and centering ability of curved mesiobuccal canals in maxillary molars after biomechanical preparation with different nickel-titanium (NiTi) rotary systems. Forty teeth with angles of curvature ranging from 20° to 40° and radii between 5.0 mm and 10.0 mm were selected and assigned into four groups (n = 10), according to the biomechanical preparative system used: Hero 642 (HR), Liberator (LB), ProTaper (PT), and Twisted File (TF). The specimens were inserted into an acrylic device and scanned with computed tomography prior to, and following, instrumentation at 3, 6 and 9 mm from the root apex. The canal degree of transportation and centering ability were calculated and analyzed using one-way ANOVA and Tukey’s tests (α = 0.05). The results demonstrated no significant difference (p > 0.05) in shaping ability among the rotary systems. The mean canal transportation was: -0.049 ± 0.083 mm (HR); -0.004 ± 0.044 mm (LB); -0.003 ± 0.064 mm (PT); -0.021 ± 0.064 mm (TF). The mean canal centering ability was: -0.093 ± 0.147 mm (HR); -0.001 ± 0.100 mm (LB); -0.002 ± 0.134 mm (PT); -0.033 ± 0.133 mm (TF). Also, there was no significant difference among the root segments (p > 0.05). It was concluded that the Hero 642, Liberator, ProTaper, and Twisted File rotary systems could be safely used in curved canal instrumentation, resulting in satisfactory preservation of the original canal shape. (author)

  17. Comparative Evaluation of Stress developed on Rotary Retreatment Instruments during Retrieval of Gutta-percha.

    Science.gov (United States)

    Sihivahanan, Dhanasekaran; Reddy, T Vinay Kumar; Thomas, Anchu Rachel; Senthilnathan, Natarajan; Sivakumar, Murali; Shivanna, Sushmita

    2017-06-01

    The aim of the study is to compare the maximum stress distribution on the rotary retreatment instruments within the root canal at cervical, middle, and the apical one-third during retreatment of gutta-percha. A human mandibular premolar was scanned, and three-dimensional geometry of the root was reconstructed using finite element analysis (FEA) software package (ANSYS). The basic model was kept unchanged; tooth models were created using the same dimensions and divided into two groups as follows: Group I: ProTaper Universal retreatment system and group II: Mtwo rotary retreatment system. The stress distribution on the surface and within the retreatment files was analyzed numerically in the FEA package (ANSYS). The FEA analysis revealed that the retreatment instruments received the greatest stress in the cervical third, followed by the apical third and the middle third. The stress generated on the ProTaper Universal retreatment system was less when compared with the Mtwo retreatment files. The study concludes that the retreatment instruments undergo higher stress in the cervical third region, and further in vivo and in vitro studies are necessary to evaluate the relationship between instrument designs, stress distribution, residual stresses after use, and the torsional fracture of the retreatment instrument. The stress developed on the rotary retreatment instruments during retrieval of gutta-percha makes the instrument to get separated. There is no instrument system, i.e., suitable for all clinical situations and it is important to understand how the structural characteristics could influence the magnitude of stresses on the instrument to prevent its fracture in use.

  18. Heat balance of the rotary kiln for the limestone burning and its analysis

    Directory of Open Access Journals (Sweden)

    Ігор Альбертович Ленцов

    2015-03-01

    Full Text Available Comparative analysis of the known methods of calculation of material and heat balances of the rotary kilns with heat exchangers for limestone burning has been done. It is shown that the methods of calculations, proposed by the authors, have restrictions and inaccuracies, associated with both the assumptions made by authors for their conditions and the design of the units. Based on the made analysis the main provisions of the generalized method of calculation of the material and heat balances, that best describes the process of limestone burning in the rotary kiln with heat exchangers, have been developed. As can be seen it is impossible to perform analytical calculation of material and heat balances of the existing rotary kiln without balance test results. Thus, in the material balance calculation, besides of the content of carbonates, hydrated moisture and impurities in the feedstock, the influence of the physical humidity, which may vary depending on season and storage conditions, should be taken into account. The amount and chemical composition of burnt dust carried away from the kiln, may differ significantly from the literature data. The value of the cold air inflow can reach 15% of the total amount of air entering the kiln, it has a significant impact on fuel consumption for lime burning. When calculating the heat balance needs to know the actual temperature of the heated air and burnt lime, temperature and flue gas composition at the outlet of the heater, the temperature of the flue dust. Determining of the heat loss to the environment through the kiln body is not possible without measuring the temperature of its surface. The accuracy of determining the heat transfer coefficient, depending on the temperature of the surface of the kiln can also have a significant impact on the calculation results

  19. Control of Regime of Unified Interphase Power Controller by the Use of Rotary Transformer

    Directory of Open Access Journals (Sweden)

    Kalinin L.P.

    2015-12-01

    Full Text Available Interphase Power Controller (IPC has some properties of the source of the current. The use of these technical devices in electrical networks, in addition to optimization of the flow distribution, contributes to limiting of short-circuit currents and limits the level of distribution of electromechanical transients between energy systems. The increase of IPC controllability allows assigning some control function upon them and ensuring a more favorable operation of the energy system generators. We have studied a variant of such a device, which is controlled by a rotary phase-shifting transformer using the asynchronous electric machines with locked phase-wound rotor.

  20. Residual Stress Examination In Surface Layers Turned By Auto-Rotary Tool

    Science.gov (United States)

    Struharňanský, Jozef; Stančeková, Dana; Martikáň, Anton; Varga, Daniel; Kuždál, Viktor; Rákoci, Jozef

    2015-12-01

    In this article, unconventional kinematics of turning is examined with the aim on influence of cutting parameters on surface layers residual stress. The auto-rotary cutting tool prototype for turning was developed, designed and constructed at the University of Zilina. The tool is made of high speed steel. Residual stress examination of material 100Cr6 was performed by non-destructive measuring method of X-ray diffraction. This method is able to determine normal and shear stress conditions without damaging the examined sample.

  1. Design and High Power Measurements of a 3 GHz Rotary Joint for Medical Applications

    CERN Document Server

    Degiovanni, Alberto; Garlasche, Marco; Giner-Navarro, Jorge; Magagnin, Paolo; Mcmonagle, Gerard; Syratchev, Igor; Wuensch, Walter

    2016-01-01

    The TUrning LInac for Protontherapy (TULIP) project requires the transport of RF power from modulator/klystron systems at rest on the floor to the linac structures mounted on a rotating gantry, via a waveguide system that can operate over a range of angles of rotation. A waveguide rotary joint capable of transporting RF power at 3 GHz and up to 20 MW has been designed and built in collaboration between TERA Foundation, CERN Beams and CERN Engineering Departments. A high-power test of the prototype has been performed at the CLIC Test Facility (CTF3), at CERN. The design and the results of the tests are reported in this article.

  2. Braking of a Light-Driven Molecular Rotary Motor by Chemical Stimuli.

    Science.gov (United States)

    van Leeuwen, Thomas; Danowski, Wojciech; Pizzolato, Stefano F; Štacko, Peter; Wezenberg, Sander J; Feringa, Ben L

    2018-01-02

    Artificial molecular motors hold great promise for application in responsive functional materials as well as to control the properties of biohybrid systems. Herein a strategy is reported to modulate the rotation of light-driven molecular motors. That is, the rotary speed of a molecular motor, functionalized with a biphenol moiety, could be decreased in situ by non-covalent substrate binding, as was established by 1 H NMR and UV/Vis spectroscopy. These findings constitute an important step in the development of multi-responsive molecular machinery. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Chemomechanical Excavation is More Time-consuming Than Rotary, but not Necessarily Hand Excavation.

    Science.gov (United States)

    Schwendicke, Falk

    2015-12-01

    Systematic review and meta-analysis of randomized clinical trials on chemomechanical caries removal. Hamama, H., et al.Oper Dent 2015;40(4):E167-178. Falk Schwendicke, DDS, PhD PURPOSE/QUESTION: How valid were the methodologies of studies on chemomechnical caries removal, and is chemomechanical caries removal more time-consuming than conventional hand or rotary excavation? Information not available Systematic review with meta-analysis of data Level 3: Other evidence Grade C (no patient-centered/relevant outcomes). Copyright © 2015 Elsevier Inc. All rights reserved.

  4. A BAPTA employing rotary transformers, stepper motors and ceramic ball bearings

    Science.gov (United States)

    Auer, W.

    1981-01-01

    The utilization of rotary transformers as an alternative to slip rings for the power transfer from solar panels to a satellite's main body could be advantageous, especially if an ac bus system is taken into consideration. Different approaches with main emphasis on the electromagnetic design were investigated and showed efficiencies of up to 99% with a 3 kW power capability. A solidly preloaded pair of ball bearings with ceramic balls assures proper transformer air gaps and acceptable torque changes over temperature and temperature gradients. The bearing and power transfer assembly is driven by a direct drive stepper motor with inherent redundancy properties and needs no caging mechanism.

  5. Improvement of the Rotary Dryers of Wet Pelletized Oil-Furnace Carbon Blacks

    Directory of Open Access Journals (Sweden)

    Zečević, M

    2010-05-01

    Full Text Available Due to the demand for higher production capacity and natural-gas energy savings, improvements were made to the rotary dryers in the drying process of wet pelletized oil-furnace carbon blacks. Since the rotary dryers were originally designed for drying semi-wet pelletized oil-furnace carbon blacks, they did not entirely satisfy optimal conditions for drying wet pelletized oil-furnace carbon blacks. Figure 1 shows the drying principle with key dimensions. The energy for drying the wet pelletized oil-furnace carbon blacks was provided by natural gas combustion in an open-furnace system with an uncontrolled feed of combustion air. Improvements on the rotary dryers were carried out by adjusting the excess oxygen in the gases passing through the butterfly valve on the dryer exhaust stack. By regulating the butterfly valve on the dryer exhaust stack, and applying the prescribed operations for drying wet pelletized oil furnace carbon blacks, the excess oxygen in the tail gases was adjusted in the range of φ = 3.0 % and 5.0 %, depending on the type of oil-furnace carbon blacks. Suggested also is installation of a direct-reverse automatic butterfly valve on the dryer exhaust stack to automatically determine the volume fraction of oxygen in the tail gas, and the volume flow rate of natural gas for combustion. The results the improvements carried out are shown in Tables 3 to 5. Table 2 shows the thermal calculations for the hood of the rotary dryer. Preheating of the process water in the temperature range of 70 °C and 80 °C is also recommended using the net heat from the oil-furnace process for wet pelletization. The results of preheating the process water are shown in Table 1. Depending on the type of oil-furnace carbon black, the aforementioned improvements resulted in natural gas energy savings ranging from 25 % to 35 % in relation to the average natural gas requirement in the drying process, and thus a reduction in carbon emissions of up to 40

  6. Non-invasive assessment of thromboembolism in rotary blood pumps: case study

    Science.gov (United States)

    Gawlikowski, Maciej; Kustosz, Roman; Głowacki, Maciej; Pydziński, Paweł; Kubacki, Krzysztof; Zakliczyński, Michał; Copik, Izabela; Pacholewicz, Jerzy

    2017-08-01

    Thromboembolic complications are one of the major problems in mechanical heart support of patients suffering from critical heart failure. The goal of the study was to present and discuss methodology of non-invasive assessment of embolization in rotary blood pumps. The study was carried out based on power consumption trend analysis as well as spectral analysis of acoustic signal produced by the pump during its operation. It has been demonstrated that the trend of power rising and presence of 3rd harmonic in acoustic spectrum corresponds to the clinical symptoms of pump embolization.

  7. Residual magnetic field in rotary machines; Campo magnetico residual en maquinas rotatorias

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez V, Esteban A; Apanco R, Marcelino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-07-01

    The residual magnetism is a phenomenon in which the magnetic dipoles of a substance are oriented in a certain degree. On the other hand, when internal forces exist capable of aligning elementary magnetic dipoles of a material, a permanent magnet is obtained. Just as in a conductor or in a material, in the elements of a rotary electrical machine magnetic fields can be induced that produce a residual magnetism or magnetization. In the rotary electrical machines, the magnetization phenomenon causes serious problems, such as the generation of induced currents that propitiate the mechanical wear in bearings, collars, trunnions and inclusive in the shaft, by effects known as pitting, frosting and spark tracks, as well as erroneous readings in vibration and temperature sensors, that in some cases can cause the shut down of the machine. In this article are presented the general concepts on the residual magnetism in rotary electrical machines, the causes that originate it and the problems that arises, as well as the demagnetization of the components that have residual magnetic field. The results obtained by the area of Electrical Equipment of the Instituto de Investigaciones Electricas are revised, during the execution of activities related to the measurement and elimination of the residual magnetic field in rotary electrical machines. [Spanish] El magnetismo residual es un fenomeno en el que los dipolos magneticos de una sustancia se encuentran orientados en un grado determinado. Por otro lado, cuando existen fuerzas internas capaces de alinear los dipolos magneticos elementales de un material, se tiene un iman permanente. Al igual que en un conductor o un material, en los elementos de una maquina electrica rotatoria se pueden inducir campos magneticos que producen un magnetismo residual o magnetizacion. En las maquinas electricas rotatorias, el fenomeno de magnetizacion causa graves problemas, como la generacion de corrientes inducidas que propician el desgaste mecanico

  8. MRT letter: full-tilt electron tomography with a piezo-actuated rotary drive.

    Science.gov (United States)

    Xu, X J; Lockwood, A; Guan, W; Gay, R; Saghi, Z; Wang, J J; Peng, Y; Inkson, B J; Möbus, G

    2008-11-01

    Piezoelectric nanoactuation, which is rapidly becoming established as state-of-the-art positioning control in transmission electron microscopy (TEM), is extended here to include a rotational degree of freedom. A piezoelectric goniometer with both translational and rotary drive action has been designed with high level of miniaturization to fit into a standard TEM specimen holder shaft without compromising any of the performance of the default TEM goniometer and without any modifications to the TEM. Enhanced functionality of such a goniometer-in-goniometer is outlined and experimental results for electron tomography of nanostructures over a full tilt range of views, without any missing angles, are demonstrated.

  9. Multiple autoclave cycles affect the surface of rotary nickel-titanium files: an atomic force microscopy study.

    Science.gov (United States)

    Valois, Caroline R A; Silva, Luciano P; Azevedo, Ricardo B

    2008-07-01

    The purpose of this study was to evaluate the surface of rotary nickel-titanium (Ni-Ti) files after multiple autoclave cycles. Two different types of rotary Ni-Ti (Greater Taper and ProFile) were attached to a glass base. After 1, 5, and 10 autoclave cycles the files were positioned in the atomic force microscope. The analyses were performed on 15 different points. The same files were used as control before any autoclave cycle. The following vertical topographic parameters were measured: arithmetic mean roughness, maximum height, and root mean square. The differences were tested by analysis of variance with Tukey test. All topographic parameters were higher for both Greater Taper and ProFile after 10 cycles compared with the control (P autoclave cycles increase the depth of surface irregularities located on rotary Ni-Ti files.

  10. Forming of Hollow Shaft Forging From Titanium Alloy Ti6Al4V by Means of Rotary Compression

    Directory of Open Access Journals (Sweden)

    Tomczak J.

    2015-04-01

    Full Text Available This paper presents chosen results of theoretical-experimental works concerning forming of hollow shafts forgings from titanium alloys, which are applied in aviation industry. At the first stage of conducted analysis, the forging forming process was modeled by means of finite element method. Calculations were made using software Simufact Forming. On the basis of performed simulations optimal parameters of rotary compression process were determined. Next, experimental tests of forging forming in laboratory conditions were made. For the research needs, a forging aggregate, designed by the Authors, was used. Conducted research works confirmed the possibility of metal forming (by means of rotary compression of hollow shafts from hard workable titanium alloys. Numerous advantages of rotary compression process, make it attractive both for low series production (aircraft industry and for mass production (automotive industry.

  11. Production of activated charcoal beads or green moldnings useful in stationary or fluidized bed uses rotary stirrer(s) for mixing carbonaceous powder with binder

    DEFF Research Database (Denmark)

    2000-01-01

    In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s).......In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s)....

  12. An in-vitro comparison of canal debridement efficiency between three systems of Rotary, Reciprocal and Vertical

    Directory of Open Access Journals (Sweden)

    Sheykhrezaee MS.

    2004-08-01

    Full Text Available Statement of Problem: Total removal of tissues and remnant microorganisms as well as canal shaping are the essential objectives of endodontic therapy. A successful endodontic treatment is obtained through Shilder’s principals, however; complete observation of this technique using stainless steel files manually is problematic and time-consuming. Modern technology, in order to eliminate such problems, has presented new facilities such as Nickel-Titanium (NiTi files and engine driven instruments. Purpose: The aim of this in-vitro study was to compare the canal debridement efficiency of three engine driven instruments: Rotary, Reciprocal and Vertical. Materials and Methods: In this experimental study, 60 mesial roots of human first and second mandibular molars were divided into three groups randomly. In each sample, one canal was considered as case, the other one as control. Files used in Reciprocal and vertical groups were of handy Ni-Ti type and in rotary group, rotary Ni-Ti files were used. After debridement, the roots were sectioned at 3mm and 5mm from anatomic apex, stained and examined under light microscope. Comparison criteria between case and control groups were based on residual debris and predentin and the level of root canal preparation and shaping after debridement. Data were subjected to kruskal-Wallis non-parametric test. Results: There was no significant difference between the efficiency of debridement at 3mm and 5mm sections between all groups. But difference in time consumption was significant ranked from the shortest to the longest as rotary, reciprocal and vertical. Conclusion: The efficiency of debridement between the three automated instruments was approximately equal, however; the instrumentation time was different between three groups. Rotary system was the fastest one, as compared with reciprocal (second and vertical (last. It may be concluded that rotary system has a superiority over the other two groups in conventional

  13. Performance of A Horizontal Cylinder Type Rotary Dryer for Drying Process ofOrganic Compost from Solid Waste Cocoa Pod

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2008-07-01

    Full Text Available Cocoa pod husk is the bigest component of cocoa pod, about 70% of total ht of mature pod, and to potentially used as organic compost source. Poten tial solid waste of cocoa pod husk from a cocoa processing centre is about 15— 22 m3/ha/year. A cocoa plantation needs about 20—30 ton/ha/year of organic matters. One of important steps in compos processing technology of cocoa pod solid waste is drying process. Organic compost with 20% moisture content is more easy in handling, application, storage and distribution. Indonesian Coffee and Cocoa Research Institute has designed and tested a horizontal cylinder type rotary dryer for drying process of organic compos from solid waste cocoa pod with kerosene burner as energy sources. The objective of this research is to study performance of a horizontal cylinder type rotary dryer using kerosene burner as energy source for drying process of organic compost from solid waste cocoa pod. The material used was solid waste cocoa pod with 70—75% moisture content (wet basis, 70% size particle larger than 4.76 mm, and 30% size particle less than 4.76 mm, 690—695 kg/m3 bulk density. Drying process temperatures treatment were 60OC, 80OC, and 100OC, and cylinder rotary speed treatments were 7 rpm, 10 rpm, dan 16 rpm. The results showed that dryer had capacity about 102—150 kg/h depend on drying temperature and cylinder rotary speed. Optimum operation condition at 100OC drying temperature, and 10 rpm cylinder rotary speed with drying time to reach final moisture content of 20% was 1,6 h, capacity 136,14 kg/ h, bulk density 410 kg/m3, porocity 45,15%, kerosene consumption as energy source was 2,57 l/h, and drying efficiency 68,34%. Key words : cocoa, drying, rotary dryer, compost, waste

  14. In vitro comparison of the cutting efficiency and temperature production of ten different rotary cutting instruments. Part II: electric handpiece and comparison with turbine.

    Science.gov (United States)

    Ercoli, Carlo; Rotella, Mario; Funkenbusch, Paul D; Russell, Scott; Feng, Changyong

    2009-05-01

    The cutting behavior of dental rotary cutting instruments is influenced by the handpiece used. While the turbine handpiece has been extensively tested in previous studies, limited published information exists on the use of rotary cutting instruments with the electric handpiece system and on possible interactions between rotary cutting instruments and handpiece type. The purpose of this study was to examine the cutting performance of a wide selection of rotary cutting instruments tested with the electric handpiece and compare the results with those of the air-turbine handpiece (Part I), identifying possible interactions between handpiece type and rotary cutting instruments. Ten groups of rotary cutting instruments (n=30) designed for tooth preparation were selected: 9 diamond (7 multi-use, 2 disposable) and 1 carbide. Macor blocks (n=75) were used as a substrate, and 4 cuts were made on each specimen, using a new rotary cutting instrument each time, for a total of 300 cuts. The cuts were performed with an electric handpiece (Intramatic Lux K200), with the same methods used in the Part I study. To qualitatively evaluate the rotary cutting instrument surface characteristics, 1 specimen from each group was examined 3 times with a scanning electron microscope (SEM): before use, then after use, but before being cleaned and sterilized, and finally, after ultrasonic cleaning. To compare rotary cutting instrument performance between the turbine and electric handpieces, the data were analyzed using 2-way ANOVA to study the main effects of the group of rotary cutting instruments, handpieces, and their interaction. For analysis of the significant main effect, 1-way ANOVA and Tukey's Studentized Range test were used (alpha=.05). Compared to the baseline temperature, all rotary cutting instruments showed a reduction of the temperature in the simulated pulp chamber when tested with the electric handpiece. The Great White Ultra (carbide bur) showed the highest rate of advancement

  15. Effect of Air Cleaning Technologies in Conjunction With the Use of Rotary Heat Exchangers in Residential Buildings

    DEFF Research Database (Denmark)

    Afshari, Alireza; Bergsøe, Niels Christian; Ekberg, Lars

    2013-01-01

    This study is part of a research project concerning the possibilities of applying efficient air cleaning technologies using rotary heat exchanger in residential buildings. The purpose of this project was to identify and adapt new air-cleaning technologies for implementation in HVAC systems...... with rotary air-to-air heat exchangers. For this purpose, a mechanical filter with low pressure drop and a 4 cm thick activated carbon filter were selected for testing in a laboratory environment. The measurements included testing of the filters, separately and combined, in a ductwork to study the efficiency...

  16. Redesign Alat Las Gesek Rotari Dengan Pendekatan Fault Tree Analysis (FTA) Dan Design for Manufacture and Assembly (DFMA)

    OpenAIRE

    ', Ricky '; ', Yohanes '; Badri, Muftil '

    2016-01-01

    The FTA is a method to identify the failure of system. Whilst, the DFMA is a method to determine how to design of product, which is purposed to increases the quality of product and make easily the product assembly process. The rotary friction welding is one of type of friction welding, that principle is both of surfaces by friction which one end is fixed and then provides axial pressure to against another the rotating surface until both surface forge together. The Rotary friction welding mach...

  17. Motions of the running horse and cheetah revisited: fundamental mechanics of the transverse and rotary gallop.

    Science.gov (United States)

    Bertram, John E A; Gutmann, Anne

    2009-06-06

    Mammals use two distinct gallops referred to as the transverse (where landing and take-off are contralateral) and rotary (where landing and take-off are ipsilateral). These two gallops are used by a variety of mammals, but the transverse gallop is epitomized by the horse and the rotary gallop by the cheetah. In this paper, we argue that the fundamental difference between these gaits is determined by which set of limbs, fore or hind, initiates the transition of the centre of mass from a downward-forward to upward-forward trajectory that occurs between the main ballistic (non-contact) portions of the stride when the animal makes contact with the ground. The impulse-mediated directional transition is a key feature of locomotion on limbs and is one of the major sources of momentum and kinetic energy loss, and a main reason why active work must be added to maintain speed in locomotion. Our analysis shows that the equine gallop transition is initiated by a hindlimb contact and occurs in a manner in some ways analogous to the skipping of a stone on a water surface. By contrast, the cheetah gallop transition is initiated by a forelimb contact, and the mechanics appear to have much in common with the human bipedal run. Many mammals use both types of gallop, and the transition strategies that we describe form points on a continuum linked even to functionally symmetrical running gaits such as the tölt and amble.

  18. Effects of turning frequency on compost stability and some chemical characteristics in a rotary drum composter.

    Science.gov (United States)

    Kalamdhad, Ajay S; Kazmi, A A

    2009-03-01

    Effect of turning frequency on quality, namely some chemical characteristics (temperature, moisture content, pH, electrical conductivity, total organic matter, nitrogen dynamics, phosphorus and trace elements) and stability of compost (biochemical oxygen demand, chemical oxygen demand, rate of oxygen consumption and carbon dioxide evolution) in a rotary drum were studied. Composting was stimulated by three turns of rotary drum at different time intervals i.e. at the gap of 6h (Run A), 12h (Run B), 18 h (Run C) and 24h (Run D) for 15 d. It was observed that Run D (24h turning frequency) caused longer thermophilic phase (4d) with a higher rise at temperature 58 degrees C; consequently, peak of maximum temperature was shifted along with the increase of turning frequency. Around 23% of available carbon in Run D was utilized by micro-organisms and contained lower final electrical conductivity (1.32 dS m(-1)) possibly causing lesser phytotoxicity effects on the growth of plants. The percentage increase in total nitrogen and total phosphorus (organic and inorganic) in Run D was found to be 45% and 37% as compared to 7% and 17%, 6% and 32% and 18% and 30% in Run A, B, and C, respectively, indicating higher mineralization. The final values of respiration rates (CO(2) evolution and oxygen uptake rate) for Run D was found to be the lowest, nevertheless, other runs also provided relatively stable compost.

  19. The Rotary Zone Thermal Cycler: A Low-Power System Enabling Automated Rapid PCR

    Science.gov (United States)

    Bartsch, Michael S.; Renzi, Ronald F.; Van de Vreugde, James L.; Kim, Hanyoup; Knight, Daniel L.; Sinha, Anupama; Branda, Steven S.; Patel, Kamlesh D.

    2015-01-01

    Advances in molecular biology, microfluidics, and laboratory automation continue to expand the accessibility and applicability of these methods beyond the confines of conventional, centralized laboratory facilities and into point of use roles in clinical, military, forensic, and field-deployed applications. As a result, there is a growing need to adapt the unit operations of molecular biology (e.g., aliquoting, centrifuging, mixing, and thermal cycling) to compact, portable, low-power, and automation-ready formats. Here we present one such adaptation, the rotary zone thermal cycler (RZTC), a novel wheel-based device capable of cycling up to four different fixed-temperature blocks into contact with a stationary 4-microliter capillary-bound sample to realize 1-3 second transitions with steady state heater power of less than 10 W. We demonstrate the utility of the RZTC for DNA amplification as part of a highly integrated rotary zone PCR (rzPCR) system that uses low-volume valves and syringe-based fluid handling to automate sample loading and unloading, thermal cycling, and between-run cleaning functionalities in a compact, modular form factor. In addition to characterizing the performance of the RZTC and the efficacy of different online cleaning protocols, we present preliminary results for rapid single-plex PCR, multiplex short tandem repeat (STR) amplification, and second strand cDNA synthesis. PMID:25826708

  20. The degradation of lining of rotary furnaces in the production of zinc oxide

    Directory of Open Access Journals (Sweden)

    Natália Luptáková

    2014-06-01

    Full Text Available This paper is closely connected with the complex problem of degradation relating to the refractories of rotary furnace linings in the production of zinc oxide. Zinc oxide can be produced by variety of ways, but the most common method of production which is used in Europe is indirect, i.e. pyrolytic combustion of zinc. This method is also called "French process" of manufacturing ZnO. But this mentioned method of preparation leads to the creation of the enormous amount of zinc slag including chemical complexes of elements Fe, Zn and Al. The mechanism of degradation of the lining leads to slag rests and it is closely connected with the mutual interaction of the aggressive agents with the components of the lining. This process creates a new undesired surface layer which increased the overall thickness of zinc slag. Stuck slag has the influence on rapid degradation of the linings and moreover it also decreases the production quality of ZnO. Analysis results introduced in this paper are significant information for minimizing of degradation of rotary furnaces.  

  1. Optimization and testing of a continuous rotary motor based on shape memory wires and overrunning clutches

    Science.gov (United States)

    Scirè Mammano, Giovanni; Dragoni, Eugenio

    2015-04-01

    A relatively unexplored but extremely attractive field for the application of the shape memory technology is the area of rotary actuators, especially for generating continuous rotations. This paper deals with a novel design of a rotary motor based on SMA wires and overrunning clutches which features high output torque and boundless angular stroke in a compact package. The concept uses a long SMA wire wound round a low-friction cylindrical drum upon which the wire can contract and extend with minimum effort and limited space demand. Fitted to the output shaft by means of an overrunning clutch the output shaft rotates unidirectionally despite the sequence of contractions-elongation cycles of the wire. Following a design procedure developed in a former paper, a six-stage miniature prototype is built and tested showing excellent performance in terms of torque, speed and power density. Characteristic performances of the motor are as follows: size envelope = 48×22×30 mm3; maximum torque = 20 Nmm; specific torque = 6.31×10-4 Nmm/mm3; rotation per module = 15 deg; continuous speed (unloaded) = 4 rpm.

  2. The Effect of Wear on the Performance of a Rotary Lip Seal.

    Science.gov (United States)

    Guo, Fei; Jia, Xiaohong; Longke, Wang; Salant, Richard F; Wang, Yuming

    2014-10-01

    Theoretical analysis, combined with experimental verification, is used to study the effect of wear on the performance of a rotary lip seal as characterized by the pumping rate and friction torque. The performance of a rotary lip seal is determined by the sealing lip surface microscopic characteristics and contact characteristics at the sealing zone. The variation of the contact characteristics with wear has been established based on the variation of the sealing lip profiles measured by using a trilinear coordinate measuring instrument. The impression method is used to copy the lip surface microtopography at different wear times and then an optical interferometer is used to measure the impression surface microtopography to obtain the variation of roughness with wear. The variations of the roughness, contact characteristics, and approximate contact temperature with wear are inserted into a mixed lubrication model to obtain the variations of the pumping rate and friction torque. A comparison of the simulated results with those from experimental measurement verifies the validity of the theoretical analysis.

  3. Development of High Speed Inverter Rotary Compressor for the Air-conditioning System

    Science.gov (United States)

    Kang, Seoung-Min; Yang, Eun-soo; Shin, Jin-Ung; Park, Joon-Hong; Lee, Se-Dong; Ha, Jong-Hun; Son, Young-Boo; Lee, Byeong-Chul

    2015-08-01

    In order to meet the various operating loads of an air-conditioning system, an inverter compressor with a wide operational range is necessary. One of the ways to achieve a wide operation range is to drive a small capacity compressor at high speed. Moreover, it is possible to maximize the efficiency in part-load operation condition close to actual operating conditions and to reduce the cost by compact design of a small capacity compressor. In addition, the shortage of maximum capacity, due to the small rated capacity, is covered through high speed operation. However, in general, if the compressor operates at high speed, problems occurs such as reduced efficiency due to friction, increased noise, increased amount of oil discharge and decreased durability of the main components. In order to solve these problems the following have been investigated: optimized dimension parameters of the compression chamber, enhanced shaft design and the structure for the reduction of oil discharge and noise at high speed operation. Finally the high speed inverter rotary compressor with high efficiency and more compact size has been developed as compared with the conventional rotary compressor.

  4. Ultra-durable rotary micromotors assembled from nanoentities by electric fields.

    Science.gov (United States)

    Guo, Jianhe; Kim, Kwanoh; Lei, Kin Wai; Fan, D L

    2015-07-14

    Recently, we reported an innovative type of micromotors consisting of nanowires as rotors and patterned Au/Ni/Cr nanodisks as bearings. The dimensions of micromotors were less than 1 μm, and could continuously rotate for 15 hours over 240 000 cycles. To understand the limitation of their lifetime, we systematically investigated the rotation dynamics by analytical modeling and determined the time-dependent torques and forces involved in the rotation. From the forces and torques, the extent of wear of micromotors was successfully derived, which agreed well with the experimental characterization. The results also proved that the frictional force linearly increases with the loading in such rotary nanodevices operating in suspension, consistent with the prediction of the non-adhesive multi-asperity friction theory. With these understandings, we enhanced the design of micromotors and achieved an operation lifetime of 80 hours and over 1.1 million total rotation cycles. This research, shedding new light on the frictional mechanism of recently reported nanowire micromotors with demonstration of the most durable rotary nanomechanical devices of similar dimensions to the best of our knowledge, can be inspiring for innovative design of future nanomechanical devices with ultra-long lifetime for practical applications.

  5. Evaluation of surface characteristics of rotary nickel-titanium instruments produced by different manufacturing methods.

    Science.gov (United States)

    Inan, U; Gurel, M

    2017-02-01

    Instrument fracture is a serious concern in endodontic practice. The aim of this study was to investigate the surface quality of new and used rotary nickel-titanium (NiTi) instruments manufactured by the traditional grinding process and twisting methods. Total 16 instruments of two rotary NiTi systems were used in this study. Eight Twisted Files (TF) (SybronEndo, Orange, CA, USA) and 8 Mtwo (VDW, Munich, Germany) instruments were evaluated. New and used of 4 experimental groups were evaluated using an atomic force microscopy (AFM). New and used instruments were analyzed on 3 points along a 3 mm. section at the tip of the instrument. Quantitative measurements according to the topographical deviations were recorded. The data were statistically analyzed with paired samples t-test and independent samples t-test. Mean root mean square (RMS) values for new and used TF 25.06 files were 10.70 ± 2.80 nm and 21.58 ± 6.42 nm, respectively, and the difference between them was statistically significant (P instruments produced by twisting method (TF 25.06) had better surface quality than the instruments produced by traditional grinding process (Mtwo 25.06 files).

  6. Effect of parameter variations on the hemodynamic response under rotary blood pump assistance.

    Science.gov (United States)

    Lim, Einly; Dokos, Socrates; Salamonsen, Robert F; Rosenfeldt, Franklin L; Ayre, Peter J; Lovell, Nigel H

    2012-05-01

    Numerical models, able to simulate the response of the human cardiovascular system (CVS) in the presence of an implantable rotary blood pump (IRBP), have been widely used as a predictive tool to investigate the interaction between the CVS and the IRBP under various operating conditions. The present study investigates the effect of alterations in the model parameter values, that is, cardiac contractility, systemic vascular resistance, and total blood volume on the efficiency of rotary pump assistance, using an optimized dynamic heart-pump interaction model previously developed in our laboratory based on animal experimental measurements obtained from five canines. The effect of mean pump speed and the circulatory perturbations on left and right ventricular pressure volume loops, mean aortic pressure, mean cardiac output, pump assistance ratio, and pump flow pulsatility from both the greyhound experiments and model simulations are demonstrated. Furthermore, the applicability of some of the previously proposed control parameters, that is, pulsatility index (PI), gradient of PI with respect to pump speed, pump differential pressure, and aortic pressure are discussed based on our observations from experimental and simulation results. It was found that previously proposed control strategies were not able to perform well under highly varying circulatory conditions. Among these, control algorithms which rely on the left ventricular filling pressure appear to be the most robust as they emulate the Frank-Starling mechanism of the heart. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  7. Impact Dynamics of a Percussive System Based on Rotary-Percussive Ultrasonic Drill

    Directory of Open Access Journals (Sweden)

    Yinchao Wang

    2017-01-01

    Full Text Available This paper presents an impact dynamic analysis of a percussive system based on rotary-percussive ultrasonic drill (RPUD. The RPUD employs vibrations on two sides of one single piezoelectric stack to achieve rotary-percussive motion, which improves drilling efficiency. The RPUD’s percussive system is composed of a percussive horn, a free mass, and a drill tool. The percussive horn enlarges longitudinal vibration from piezoelectric stack and delivers the vibration to the drill tool through the free mass, which forms the percussive motion. Based on the theory of conservation of momentum and Newton’s impact law, collision process of the percussive system under no-load condition is analyzed to establish the collision model between the percussive horn, the free mass, and the drill tool. The collision model shows that free mass transfers high-frequency small-amplitude vibration of percussive horn into low-frequency large-amplitude vibration of drill tool through impact. As an important parameter of free mass, the greater the weight of the free mass, the higher the kinetic energy obtained by drill tool after collision. High-speed camera system and drilling experiments are employed to validate the inference results of collision model by using a prototype of the RPUD.

  8. Oscillometric measurement of arterial pulse pressure for patients supported by a rotary blood pump.

    Science.gov (United States)

    Yu, Yih-Choung; Peterson, Anna

    2015-01-01

    A computer model has been developed to evaluate the accuracy of an oscillometric method to measure the arterial pulse pressure from a patient with a rotary ventricular assist device (VAD). This computer model consists of three major components: the cardiovascular system, the HeartMate II VAD, and the operation of an automated cuff. Simulation was performed to mimic failure, recovery, and normal cardiac functions of a patient, supported by the HeartMate II VAD at different levels from minimum to maximum. The oscillating cuff pressure, simulating the air pressure of a deflecting cuff, was obtained from simulation under different conditions to test the accuracy of an oscillometric algorithm in determining the arterial pulse pressure. The algorithm was able to detect the systolic and diastolic arterial pressure with the error within ±2 mmHg in most cases, except the cases when ventricular suction, induced by the VAD, occurred. The results from this study suggested that the oscillometric algorithm is capable to accurately detect the arterial pulse pressure for a rotary VAD patient if the algorithm is properly tuned.

  9. Research on application of photoelectric rotary encoder in space optical remote sensor

    Science.gov (United States)

    Zheng, Jun; Qi, Shao-fan; Wang, Yuan-yuan; Zhang, Zhan-dong

    2016-11-01

    For space optical remote sensor, especially wide swath detecting sensor, the focusing control system for the focal plane should be well designed to obtain the best image quality. The crucial part of this system is the measuring instrument. For previous implements, the potentiometer, which is essentially a voltage divider, is usually introduced to conduct the position in feedback closed-loop control process system. However, the performances of both electro-mechanical and digital potentiometers is limited in accuracy, temperature coefficients, and scale range. To have a better performance of focal plane moving detection, this article presents a new measuring implement with photoelectric rotary encoder, which consists of the photoelectric conversion system and the signal process system. In this novel focusing control system, the photoelectric conversion system is fixed on main axis, which can transform the angle information into a certain analog signal. Through the signal process system, after analog-to-digital converting and data format processing of the certain analog signal, the focusing control system can receive the digital precision angle position which can be used to deduct the current moving position of the focal plane. For utilization of space optical remote sensor in aerospace areas, the reliability design of photoelectric rotary encoder system should be considered with highest priority. As mentioned above, this photoelectric digital precision angle measurement device is well designed for this real-time control and dynamic measurement system, because its characters of high resolution, high accuracy, long endurance, and easy to maintain.

  10. Numerical Calculation of Total Radial Forces and Rotary Moments From the Cylinders Surface

    Science.gov (United States)

    Panichkin, A. V.; Varepo, L. G.

    2017-06-01

    The determining of the acting moments of force when the cylinder is characterized by roughness after the deformation of contacting surfaces of the rotating cylinders and the substrate while interacting with incompressible viscous liquid is still one of the main problems in printing. The numerical calculation of the radial forces and rotary moments with integral formulas for deforming surfaces was carried out with regard to the discrete grid at the grid points of the upper and lower cylinders surfaces and their deformation speeds. The paper considers the results of the numerical modeling for the quantitative assessment of rotary moments of radial forces from the cylinders surfaces, occurring during the transfer of incompressible viscous liquid on the substrate between two rotating cylinders. The definition of dynamic forces (radial and tangential force, moment of force) in the discrete form on the example of one computational cell is presented. It is noted, that the consideration of boundary deformation results in the decrease of the calculated dynamic values by 3-5 times as well as to the reducing of the ink bleeding near the boundaries of the printing surface.

  11. [Transurethral enucleation plus pneumo-cystostomy rotary cut for large benign prostatic hyperplasia].

    Science.gov (United States)

    Dong, Yan-Xin; Wu, Yang; Zeng, Rui; Yang, Jun-Chang; Gao, Xiao-Kang; Zhu, Ming-De; Huo, Shuang-Jin; Li, Dong; Niguti

    2014-06-01

    To investigate the feasibility, effectiveness and practicability of transurethral enucleation plus pneumocystostomy rotary cut (TUE + PCRC) for large benign prostatic hyperplasia (BPH). We performed TUE + PCRC for 26 BPH patients aged 62 - 85 years with the prostate volume of 80 - 165 ml. We conducted transurethral enucleation of the hyperplastic prostate glands and pushed them into the bladder, followed by bladder puncture for pneumo-cystostomy rotary cut. All the surgical procedures were successfully accomplished, with the mean surgical time of 41 (32 - 54) minutes and intraoperative blood loss < 60 ml in all the cases. Twenty-three of the patients were followed up for 2 - 8 months, which revealed no stricture of the urethra or any other severe complications. Compared with the preoperative baseline, significant improvement was achieved in the IPSS (6.5 +/- 2.2 vs 26.2 +/- 2.4), QOL (1.4 +/- 0.9 vs 4.6 +/- 1.2) and Qmax ([5.8 +/- 1.0 ] vs [19.6 +/- 2.8] ml/s) of the patients after surgery (P < 0.01). TUE + PCRC, with its advantages of short operation time and less severe complications, is a safe and effective approach to the management of large BPH.

  12. The study of heat penetration of kimchi soup on stationary and rotary retorts.

    Science.gov (United States)

    Cho, Won-Il; Park, Eun-Ji; Cheon, Hee Soon; Chung, Myong-Soo

    2015-03-01

    The aim of this study was to determine the heat-penetration characteristics using stationary and rotary retorts to manufacture Kimchi soup. Both heat-penetration tests and computer simulation based on mathematical modeling were performed. The sterility was measured at five different positions in the pouch. The results revealed only a small deviation of F 0 among the different positions, and the rate of heat transfer was increased by rotation of the retort. The thermal processing of retort-pouched Kimchi soup was analyzed mathematically using a finite-element model, and optimum models for predicting the time course of the temperature and F 0 were developed. The mathematical models could accurately predict the actual heat penetration of retort-pouched Kimchi soup. The average deviation of the temperature between the experimental and mathematical predicted model was 2.46% (R(2)=0.975). The changes in nodal temperature and F 0 caused by microbial inactivation in the finite-element model predicted using the NISA program were very similar to that of the experimental data of for the retorted Kimchi soup during sterilization with rotary retorts. The correlation coefficient between the simulation using the NISA program and the experimental data was very high, at 99%.

  13. Design of a rotary reactor for chemical-looping combustion. Part 1: Fundamentals and design methodology

    KAUST Repository

    Zhao, Zhenlong

    2014-04-01

    Chemical-looping combustion (CLC) is a novel and promising option for several applications including carbon capture (CC), fuel reforming, H 2 generation, etc. Previous studies demonstrated the feasibility of performing CLC in a novel rotary design with micro-channel structures. In the reactor, a solid wheel rotates between the fuel and air streams at the reactor inlet, and depleted air and product streams at exit. The rotary wheel consists of a large number of micro-channels with oxygen carriers (OC) coated on the inner surface of the channel walls. In the CC application, the OC oxidizes the fuel while the channel is in the fuel zone to generate undiluted CO2, and is regenerated while the channel is in the air zone. In this two-part series, the effect of the reactor design parameters is evaluated and its performance with different OCs is compared. In Part 1, the design objectives and criteria are specified and the key parameters controlling the reactor performance are identified. The fundamental effects of the OC characteristics, the design parameters, and the operating conditions are studied. The design procedures are presented on the basis of the relative importance of each parameter, enabling a systematic methodology of selecting the design parameters and the operating conditions with different OCs. Part 2 presents the application of the methodology to the designs with the three commonly used OCs, i.e., nickel, copper, and iron, and compares the simulated performances of the designs. © 2013 Elsevier Ltd. All rights reserved.

  14. MATHEMATICAL MODEL FOR THE STUDY AND DESIGN OF A ROTARY-VANE GAS REFRIGERATION MACHINE

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-08-01

    Full Text Available This paper presents a mathematical model of calculating the main parameters the operating cycle, rotary-vane gas refrigerating machine that affect installation, machine control and working processes occurring in it at the specified criteria. A procedure and a graphical method for the rotary-vane gas refrigerating machine (RVGRM are proposed. A parametric study of the main geometric variables and temperature variables on the thermal behavior of the system is analyzed. The model considers polytrope index for the compression and expansion in the chamber. Graphs of the pressure and temperature in the chamber of the angle of rotation of the output shaft are received. The possibility of inclusion in the cycle regenerative heat exchanger is appreciated. The change of the coefficient of performance machine after turning the cycle regenerative heat exchanger is analyzed. It is shown that the installation of a regenerator RVGRM cycle results in increased COP more than 30%. The simulation results show that the proposed model can be used to design and optimize gas refrigerator Stirling.

  15. Robust unidirectional rotation in three-tooth Brownian rotary ratchet systems

    Science.gov (United States)

    Tutu, Hiroki; Nagata, Soichiro

    2013-02-01

    We apply a simple Brownian ratchet model to an artificial molecular rotary system mounted in a biological membrane, in which the rotor always maintains unidirectional rotation in response to a linearly polarized weak ac field. Because the rotor and stator compose a ratchet system, we describe the motion of the rotor tip with the Langevin equation for a particle in a two-dimensional three-tooth ratchet potential of threefold symmetry. Unidirectional rotation can be induced under the field and optimized by stochastic resonance, wherein the mean angular momentum (MAM) of the rotor exhibits a bell-shaped curve for the noise strength. We obtain analytical expressions for the MAM and power loss from the corresponding Fokker-Planck equation, via a Markov transition model for coarse-grained states (six-state model). The MAM expression reveals a significant effect depending on the chirality of the ratchet potential: in achiral cases, the MAM approximately vanishes with respect to the polarization angle ϕ of the field; in chiral cases, the MAM does not crucially depend on ϕ, but depends on the direction of the ratchet; i.e., the parity of the unidirectional rotation is inherent in the ratchet structure. This feature is useful for artificial rotary systems to maintain robust unidirectional rotation independent of the mounting condition.

  16. A combined infrared/heat pump drying technology applied to a rotary dryer

    Directory of Open Access Journals (Sweden)

    K. PÄÄKKÖNEN

    2008-12-01

    Full Text Available The short drying time and low product temperature makes it suitable for drying such heat-sensitive materials as herbs and vegetables. The purpose of this work was to develop a small-scale dryer for herbs and vegetables. A prototype rotary dryer combining infrared radiation with a so-called heat pump drying method was applied in drying experiments for several herbs and vegetables. The drying experiments were performed under actual crop production conditions. The drying curves for leaves of birch (Betula spp., rosebay willowherb (Epilobium angustifolium and dandelion (Taraxacum spp. as well as slices of red beet (Beta vulgaris and carrot (Daucus carota are presented. During the drying operation, temperature and humidity of the drying air were recorded, as well as the energy consumed in drying. The quality parameters measured were water content, colour and rehydration ratio. In the present rotary dryer design, intermittent irradiation and mixing of the product enable to avoid overheating, which is particularly important for maintaining product quality. In this dryer design the drying drum slowly rotates and simultaneously mixes the product. The infrared heaters are attached to a panel, allowing the product to receive infrared radiation periodically.

  17. Gasification of Greek lignite in an indirect heat (allothermal) rotary kiln gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Androutsopoulos, G.P.; Hatzilyberis, K.S.; Theofilou, N.A.; Agalianos, D.S.; Chronis, C.G.; Kapassakalis, V.N.; Karsakos, A.G.; Katsaros, A.N.; Stamatakis, C.P.; Zissis, C.L. [National Technical University of Athens, Athens (Greece). Dept. of Chemical Engineering

    2003-09-01

    This work reports the performance results of a pilot-size lignite gasification plant. The feed material was Greek lignite (Megalopolis), currently being employed for electricity generation in pulverized lignite-fired thermoelectric stations. Low energy conversion efficiency, low station availability, and environmental issues call for developing improved processes, e.g., an IGCC (Integrated Gasification Combined Cycle). An indirect heat (allothermal) rotary kiln was selected as the lignite gasification reactor for developing an overall gasification process of improved efficiency. Week long gasification runs, at near atmospheric pressure and maximum temperature in the range 900-950{sup o}C, validated high DAF lignite conversions, i.e., 90-95%, and the production of a medium heating value synthesis gas (i.e., 11-13 MJ/Nm{sup 3} dry basis), despite the use of air for burning recycled product gas for process heating. Gas composition is equivalent to that of autothermal gasifiers (e.g., Lurgi, Winkler, Koppers-Totzek), which operate on oxygen, under pressure and strict moisture and particle size specifications. Similarly, the kiln gas is comparable to that of an allothermal, high-pressure, fluidized bed gasifier running with a high rank coal feed. The data indicate satisfactory gasification efficiency and a good thermal efficiency that should be improved further through heat integration of a scaled-up process based on an indirect heat rotary kiln gasifier.

  18. The Concept, Design and Performance of a Novel Rotary Kiln Type Air-Staged Biomass Gasifier

    Directory of Open Access Journals (Sweden)

    Huiyuan Shi

    2016-01-01

    Full Text Available Tar formation is the main bottleneck for biomass gasification technology. A novel rotary kiln type biomass gasification process was proposed. The concept design was based on air staging and process separation. This concept was demonstrated on a pilot scale rotary kiln reactor under ambient pressure and autothermic conditions. The pilot scale gasifier was divided into three different reaction regions, which were oxidative degradation, partial oxidation and char gasification. A series of tests was conducted to investigate the effect of key parameters. The results indicate that under optimum operating conditions, a fuel gas with high heat value of about 5500 kJ/Nm3 and gas production rate of 2.32 Nm3/kg could be produced. Tar concentration in the fuel gas could be reduced to 108 mg/Nm3 (at the gasifier outlet and 38 mg/Nm3 (after gas conditioning. The cold gas efficiency and carbon conversion rate reached 75% and 78%, respectively. The performance of this gasification system shows considerable potential for implementation in distributed electricity and heat supply projects.

  19. Research and design of portable photoelectric rotary table data-acquisition and analysis system

    Science.gov (United States)

    Yang, Dawei; Yang, Xiufang; Han, Junfeng; Yan, Xiaoxu

    2015-02-01

    Photoelectric rotary table as the main test tracking measurement platform, widely use in shooting range and aerospace fields. In the range of photoelectric tracking measurement system, in order to meet the photoelectric testing instruments and equipment of laboratory and field application demand, research and design the portable photoelectric rotary table data acquisition and analysis system, and introduces the FPGA device based on Xilinx company Virtex-4 series and its peripheral module of the system hardware design, and the software design of host computer in VC++ 6.0 programming platform and MFC package based on class libraries. The data acquisition and analysis system for data acquisition, display and storage, commission control, analysis, laboratory wave playback, transmission and fault diagnosis, and other functions into an organic whole, has the advantages of small volume, can be embedded, high speed, portable, simple operation, etc. By photoelectric tracking turntable as experimental object, carries on the system software and hardware alignment, the experimental results show that the system can realize the data acquisition, analysis and processing of photoelectric tracking equipment and control of turntable debugging good, and measurement results are accurate, reliable and good maintainability and extensibility. The research design for advancing the photoelectric tracking measurement equipment debugging for diagnosis and condition monitoring and fault analysis as well as the standardization and normalization of the interface and improve the maintainability of equipment is of great significance, and has certain innovative and practical value.

  20. The rotary zone thermal cycler: a low-power system enabling automated rapid PCR.

    Directory of Open Access Journals (Sweden)

    Michael S Bartsch

    Full Text Available Advances in molecular biology, microfluidics, and laboratory automation continue to expand the accessibility and applicability of these methods beyond the confines of conventional, centralized laboratory facilities and into point of use roles in clinical, military, forensic, and field-deployed applications. As a result, there is a growing need to adapt the unit operations of molecular biology (e.g., aliquoting, centrifuging, mixing, and thermal cycling to compact, portable, low-power, and automation-ready formats. Here we present one such adaptation, the rotary zone thermal cycler (RZTC, a novel wheel-based device capable of cycling up to four different fixed-temperature blocks into contact with a stationary 4-microliter capillary-bound sample to realize 1-3 second transitions with steady state heater power of less than 10 W. We demonstrate the utility of the RZTC for DNA amplification as part of a highly integrated rotary zone PCR (rzPCR system that uses low-volume valves and syringe-based fluid handling to automate sample loading and unloading, thermal cycling, and between-run cleaning functionalities in a compact, modular form factor. In addition to characterizing the performance of the RZTC and the efficacy of different online cleaning protocols, we present preliminary results for rapid single-plex PCR, multiplex short tandem repeat (STR amplification, and second strand cDNA synthesis.

  1. Comparison of retreatment ability of full-sequence reciprocating instrumentation and 360° rotary instrumentation.

    Science.gov (United States)

    Capar, Ismail Davut; Gok, Tuba; Orhan, Ezgi

    2015-12-01

    The purpose of the present study was to investigate the amount of root canal filling material after root canal filling removal with 360° rotary instrumentation or reciprocating motion with the same file sequence. Root canals of the 36 mandibular premolars were shaped with ProTaper Universal instruments up to size F2 and filled with corresponding single gutta-percha cone and sealer. The teeth were assigned to two retreatment groups (n = 18): group 1 360° rotational motion and group 2 reciprocating motion of ATR Tecnika motors (1310° clockwise and 578° counterclockwise). Retreatment procedure was performed with ProTaper Universal retreatment files with a sequence of D1-3 and ProTaper Universal F3 instruments. Total time required to remove filling material were recorded. Remaining filling material was examined under stereomicroscope at ×8 magnification. The data were analysed statistically using the Mann-Whitney U test, and testing was performed at 95 % confidence level (p  0.05) in terms of remaining filling material. The total time required for retreatment was shorter in 360° rotational motion group compared to reciprocating motion group (p < 0.05). Both continuous rotation and reciprocating motion showed similar effectiveness in terms of root canal filling material removal. Using ProTaper Universal retreatment instruments with reciprocating motion of ATR motor and conventional rotary motion have similar efficacy in root canal filling removal.

  2. Mechanical and Metallurgical Properties of Various Nickel-Titanium Rotary Instruments.

    Science.gov (United States)

    Shim, Kyu-Sang; Oh, Soram; Kum, KeeYeon; Kim, Yu-Chan; Jee, Kwang-Koo; Chang, Seok Woo

    2017-01-01

    The aim of this study was to investigate the effect of thermomechanical treatment on mechanical and metallurgical properties of nickel-titanium (NiTi) rotary instruments. Eight kinds of NiTi rotary instruments with sizes of ISO #25 were selected: ProFile, K3, and One Shape for the conventional alloy; ProTaper NEXT, Reciproc, and WaveOne for the M-wire alloy; HyFlex CM for the controlled memory- (CM-) wire; and TF for the R-phase alloy. Torsional fracture and cyclic fatigue fracture tests were performed. Products underwent a differential scanning calorimetry (DSC) analysis. The CM-wire and R-phase groups had the lowest elastic modulus, followed by the M-wire group. The maximum torque of the M-wire instrument was comparable to that of a conventional instrument, while those of the CM-wire and R-phase instruments were lower. The angular displacement at failure (ADF) for the CM-wire and R-phase instruments was higher than that of conventional instruments, and ADF of the M-wire instruments was lower. The cyclic fatigue resistance of the thermomechanically treated NiTi instruments was higher. DSC plots revealed that NiTi instruments made with the conventional alloy were primarily composed of austenite at room temperature; stable martensite and R-phase were found in thermomechanically treated instruments.

  3. F/A-18 forebody vortex control. Volume 2: Rotary-balance tests

    Science.gov (United States)

    Kramer, Brian R.; Suarez, Carlos J.; Malcolm, Gerald N.; Ayers, Bert F.

    1994-01-01

    A rotary-balance wind tunnel test was conducted on a six percent model of the F/A-18 at the NASA Ames 7 X 10-Foot Low Speed Wind Tunnel. The data reduction was specially written for the test in National Instruments' LabVIEW. The data acquisition, reduction and analysis was performed with a Macintosh computer. The primary objective of the test was to evaluate the effectiveness of several forebody vortex control configurations in a rotary flow field. The devices that were found to be the most effective during the static tests (Volume 1) were investigated and included both mechanical and pneumatic configurations. The mechanical systems evaluated were small, single and dual, rotating nose tip strakes and a vertical nose strake. The jet blowing configuration used nozzles canted inboard 60 degrees. A two segment tangential slot was also evaluated. The different techniques were evaluated at angles of attack of 30 degrees, 45 degrees, 51 degrees, and 60 degrees. Sideslip and Reynolds number were varied for some of the configurations. All of the techniques proved to be effective in the rotating flow field. The vertical nose strake had the largest 'envelope' of effectiveness. Forebody vortex control provides large, robust yawing moments at medium to high angles of attack, even during combat maneuvers such as loaded roll.

  4. CFD SIMULATION FOR DEMILITARIZATION OF RDX IN A ROTARY KILN BY THERMAL DECOMPOSITION

    Directory of Open Access Journals (Sweden)

    SI H. LEE

    2017-06-01

    Full Text Available Demilitarization requires the recovery and disposal of obsolete ammunition and explosives. Since open burning/detonation of hazardous waste has caused serious environmental and safety problems, thermal decomposition has emerged as one of the most feasible methods. RDX is widely used as a military explosive due to its high melting temperature and detonation power. In this work, the feasible conditions under which explosives can be safely incinerated have been investigated via a rotary kiln simulation. To solve this problem, phase change along with the reactions of RDX has been incisively analyzed. A global reaction mechanism consisting of condensed phase and gas phase reactions are used in Computational Fluid Dynamics simulation. User Defined Functions in FLUENT is utilized in this study to inculcate the reactions and phase change into the simulation. The results divulge the effect of temperature and the varying amounts of gas produced in the rotary kiln during the thermal decomposition of RDX. The result leads to the prospect of demilitarizing waste explosives to avoid the possibility of detonation.

  5. Analysis of Horizontal Accuracy for Large Scale Rural Mapping Using Rotary Wing UAV Image

    Science.gov (United States)

    Hidayat, Husnul; Muljo Sukojo, Bangun

    2017-12-01

    In order to fulfil the need of large scale map for rural mapping, Indonesian government is now looking for alternatives of geospatial data sources. With newly developed technology, nowadays rotary wing UAV can be used to acquire very high resolution aerial imagery quickly with low cost. This research assesses the horizontal accuracy of rural mapping in 1:2000 scale using orthophoto derived from rotary wing UAV image data. The test site of this research is Kebonwaris village, Pandaan, East Java which has an area of approximately 167 hectares. Image data was taken with approximately 80% overlap each other and processed using Structure from Motion approach. Twelve GCPs coordinates were measured using differential GPS observations for georeferencing purpose. For accuracy assessment, 22 test points were established and their coordinates were measured using static differential GPS observations. The results show that the mean absolute horizontal errors are 0.071 m and 0.142 m for easting and northing respectively and the Root Mean Square Errors are 0.088 m and 0.169 m for easting and northing respectively. These RMSE values represents horizontal RMSE 0.190 m. According to Peraturan Kepala BIG No. 15 Tahun 2014, this RMSE value represents the 0.289 m horizontal accuracy based on CE90 criterion. Therefore, with this level of accuracy the UAV image data can be used to make a class 1 base map in 1:2500 scale or class 2 base map in 1:1000 scale.

  6. Synthesis of galaxite by plasma fusion & its application in refractory for cement rotary kiln

    Directory of Open Access Journals (Sweden)

    L.N. Padhi

    2017-06-01

    Full Text Available In India, chromite is used for making magnesia chrome bricks due to its low modulus of elasticity. But the use of magnesia chrome bricks in the sintering zone of cement rotary kilns causes environmental pollution due to the formation of Cr+6 compounds. In order to meet the above challenges and to satisfy the operational demands due to use of alternative fuels, now-a-days, galaxite spinel is being used in place of chromite as a chrome free material. Galaxite is not available in nature and electro fusion is the main process by virtue of which it is industrially manufactured. However, the main drawback of electro-fusion process is both time and energy consumption. In such a backdrop, the present work has been carried out which describes the synthesis of galaxite by plasma fusion process and also the characterization of its refractory properties for application in cement rotary kilns. This alternative process is absolutely new, faster in approach and also economically viable. The developed magnesia galaxite brick shows higher performance rate and is also economically cost effective as compared to the conventional magnesia chrome and magnesia galaxite bricks, presently available in the market.

  7. Auto-Gopher: A Wireline Deep Sampler Driven by Piezoelectric Percussive Actuator and EM Rotary Motor

    Science.gov (United States)

    Badescu, Mircea; Ressa, Aaron; Jae Lee, Hyeong; Bar-Cohen, Yoseph; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

    2013-01-01

    The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.

  8. The Study of Heat Penetration of Kimchi Soup on Stationary and Rotary Retorts

    Science.gov (United States)

    Cho, Won-Il; Park, Eun-Ji; Cheon, Hee Soon; Chung, Myong-Soo

    2015-01-01

    The aim of this study was to determine the heat-penetration characteristics using stationary and rotary retorts to manufacture Kimchi soup. Both heat-penetration tests and computer simulation based on mathematical modeling were performed. The sterility was measured at five different positions in the pouch. The results revealed only a small deviation of F0 among the different positions, and the rate of heat transfer was increased by rotation of the retort. The thermal processing of retort-pouched Kimchi soup was analyzed mathematically using a finite-element model, and optimum models for predicting the time course of the temperature and F0 were developed. The mathematical models could accurately predict the actual heat penetration of retort-pouched Kimchi soup. The average deviation of the temperature between the experimental and mathematical predicted model was 2.46% (R2=0.975). The changes in nodal temperature and F0 caused by microbial inactivation in the finite-element model predicted using the NISA program were very similar to that of the experimental data of for the retorted Kimchi soup during sterilization with rotary retorts. The correlation coefficient between the simulation using the NISA program and the experimental data was very high, at 99%. PMID:25866751

  9. Biophysical comparison of ATP synthesis mechanisms shows a kinetic advantage for the rotary process

    Science.gov (United States)

    Anandakrishnan, Ramu; Zhang, Zining; Donovan-Maiye, Rory; Zuckerman, Daniel M.

    2016-01-01

    The ATP synthase (F-ATPase) is a highly complex rotary machine that synthesizes ATP, powered by a proton electrochemical gradient. Why did evolution select such an elaborate mechanism over arguably simpler alternating-access processes that can be reversed to perform ATP synthesis? We studied a systematic enumeration of alternative mechanisms, using numerical and theoretical means. When the alternative models are optimized subject to fundamental thermodynamic constraints, they fail to match the kinetic ability of the rotary mechanism over a wide range of conditions, particularly under low-energy conditions. We used a physically interpretable, closed-form solution for the steady-state rate for an arbitrary chemical cycle, which clarifies kinetic effects of complex free-energy landscapes. Our analysis also yields insights into the debated “kinetic equivalence” of ATP synthesis driven by transmembrane pH and potential difference. Overall, our study suggests that the complexity of the F-ATPase may have resulted from positive selection for its kinetic advantage. PMID:27647911

  10. Parameter-optimized model of cardiovascular-rotary blood pump interactions.

    Science.gov (United States)

    Lim, Einly; Dokos, Socrates; Cloherty, Shaun L; Salamonsen, Robert F; Mason, David G; Reizes, John A; Lovell, Nigel H

    2010-02-01

    A lumped parameter model of human cardiovascular-implantable rotary blood pump (iRBP) interaction has been developed based on experimental data recorded in two healthy pigs with the iRBP in situ. The model includes descriptions of the left and right heart, direct ventricular interaction through the septum and pericardium, the systemic and pulmonary circulations, as well as the iRBP. A subset of parameters was optimized in a least squares sense to faithfully reproduce the experimental measurements (pressures, flows and pump variables). Our fitted model compares favorably with our experimental measurements at a range of pump operating points. Furthermore, we have also suggested the importance of various model features, such as the curvilinearity of the end systolic pressure-volume relationship, the Starling resistance, the suction resistance, the effect of respiration, as well as the influence of the pump inflow and outflow cannulae. Alterations of model parameters were done to investigate the circulatory response to rotary blood pump assistance under heart failure conditions. The present model provides a valuable tool for experiment designs, as well as a platform to aid in the development and evaluation of robust physiological pump control algorithms.

  11. Mechanical and Metallurgical Properties of Various Nickel-Titanium Rotary Instruments

    Directory of Open Access Journals (Sweden)

    Kyu-Sang Shim

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of thermomechanical treatment on mechanical and metallurgical properties of nickel-titanium (NiTi rotary instruments. Eight kinds of NiTi rotary instruments with sizes of ISO #25 were selected: ProFile, K3, and One Shape for the conventional alloy; ProTaper NEXT, Reciproc, and WaveOne for the M-wire alloy; HyFlex CM for the controlled memory- (CM- wire; and TF for the R-phase alloy. Torsional fracture and cyclic fatigue fracture tests were performed. Products underwent a differential scanning calorimetry (DSC analysis. The CM-wire and R-phase groups had the lowest elastic modulus, followed by the M-wire group. The maximum torque of the M-wire instrument was comparable to that of a conventional instrument, while those of the CM-wire and R-phase instruments were lower. The angular displacement at failure (ADF for the CM-wire and R-phase instruments was higher than that of conventional instruments, and ADF of the M-wire instruments was lower. The cyclic fatigue resistance of the thermomechanically treated NiTi instruments was higher. DSC plots revealed that NiTi instruments made with the conventional alloy were primarily composed of austenite at room temperature; stable martensite and R-phase were found in thermomechanically treated instruments.

  12. A mechanical energy harvested magnetorheological damper with linear-rotary motion converter

    Science.gov (United States)

    Chu, Ki Sum; Zou, Li; Liao, Wei-Hsin

    2016-04-01

    Magnetorheological (MR) dampers are promising to substitute traditional oil dampers because of adaptive properties of MR fluids. During vibration, significant energy is wasted due to the energy dissipation in the damper. Meanwhile, for conventional MR damping systems, extra power supply is needed. In this paper, a new energy harvester is designed in an MR damper that integrates controllable damping and energy harvesting functions into one device. The energy harvesting part of this MR damper has a unique mechanism converting linear motion to rotary motion that would be more stable and cost effective when compared to other mechanical transmissions. A Maxon motor is used as a power generator to convert the mechanical energy into electrical energy to supply power for the MR damping system. Compared to conventional approaches, there are several advantages in such an integrated device, including weight reduction, ease in installation with less maintenance. A mechanical energy harvested MR damper with linear-rotary motion converter and motion rectifier is designed, fabricated, and tested. Experimental studies on controllable damping force and harvested energy are performed with different transmissions. This energy harvesting MR damper would be suitable to vehicle suspensions, civil structures, and smart prostheses.

  13. Influence of the relative rotational speed on component features in micro rotary swaging

    Directory of Open Access Journals (Sweden)

    Ishkina Svetlana

    2015-01-01

    Full Text Available Micro rotary swaging is a cold forming process for production of micro components with determined geometry and surface. It is also possible to change the microstructure of wires and hence the material properties. Swaging dies revolve around the work piece with an overlaid radial oscillation. Newly developed tools (Flat Surface Dies, FSD feature plain surfaces and do not represent the geometry of the formed part as in conventional swaging. Using these tools allows for producing wires with triangle geometry (cross section as well as a circular shape. To test the influence of FSD on material properties by micro swaging a new method is investigated: the variation of the relative speed between the specimen and dies in infeed rotary swaging. During this specific process copper (C11000 and steel (304 Alloy wires with diameter d0 = 1 mm are formed. It is noticed that the mechanical characteristics such as ductility and strength differ from the characteristics after conventional swaging. Moreover this approach enables new possibilities to influence the geometry and the surface quality of wires. The impact of the relative speed on the processed wire features is described in this paper.

  14. Development of a three-dimensional CFD model for rotary lime kilns

    Energy Technology Data Exchange (ETDEWEB)

    Lixin Tao; Blom, Roger (FS Dynamics Sweden AB, Goeteborg (Sweden)); Nordgren, Daniel (Innventia, Stockholm (Sweden))

    2010-11-15

    In the calcium loop of the recovery cycle in a Kraft process of pulp and paper production, rotary lime kilns are used to convert the lime mud, mainly CaCO3, back to quick lime, CaO, for re-use in the causticizing process. The lime kilns are one of the major energy consumption devices for paper and pulp industry. Because of the rising oil price and new emission limits, the pulp mills have been forced to look for alternative fuels for their lime kilns. One interesting alternative to oil, often easily available at pulp mills, is biofuels such as sawdust and bark. However the practical kiln operation often encounters some difficulties because of the uncertainties around the biofuel impact on the lime kiln performance. A deeper understanding of the flame characteristics is required when shifting from oil to biofuels. Fortunately recent advances in modern Computational Fluid Dynamics, CFD, have provided the possibility to study and predict the detailed flame characteristics regarding the lime kiln performance. In this project a three-dimensional CFD model for rotary lime kilns has been developed. To simulate a rotary lime kiln the developed CFD model integrates the three essential sub-models, i.e. the freeboard hot flow model, the lime bed model and the rotating refractory wall model and it is developed based on the modern CFD package: FLUENT which is commercially available on the market. The numerical simulations using the developed CFD model have been performed for three selected kiln operations fired with three different fuel mixtures. The predicted results from the CFD modelling are presented and discussed in order to compare the impacts on the kiln performance due to the different firing conditions. During the development, the lime kiln at the Soedra Cell Moensteraas mill has been used as reference kiln. To validate the CFD model, in-plant measurements were carried out in the Moensteraas lime kiln during an experiment campaign. The results obtained from the

  15. PROTOTIPE ALAT PENGEKSTRAK PATI SAGU TIPE MIXER ROTARY BLADE BERTENAGA MOTOR BAKAR Prototype of Mixer Rotary Blade of Sago Starch Extractor Powered by Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Darma Darma

    2012-05-01

    Full Text Available Papua and West Papua Province have a large potential of sago. Approximately 994,000 hectares, mostly natural sago forest was existed in this area. Sago starch has long been an important source of nutrition troughout Papua. Product of sago palm is not only starch as source of carbohydrate for food stuff, but also for basic material of industries such as paper, plywood, hardboard, and food indutries. Traditional methods are used for starch extraction in almost all part of Papu, which is not efficient and production capacity is very low. The effort to increase sago starch production could be carry out by introducing mechanical equipment (traditional to mechanized processing. The objective of this research was to design mixer rotary blade of sago starch extraction powered by internal combustion engine. The result was prototype of mechanical sago starch extractor. The prototype has high performance with extraction capacity 160 kg of disintegrated pith per hour or equal to 33 kg of wet starch per hour, extractable starch more than 99 % while starch losses in hampas less lhan 1 %. Hopefully, application of this machine to the sago farmer will transform agricultural system from subsistence to commercial. It means that increasing of economic income. In conclusion, technically and economically this prototype was feasible. ABSTRAK Provinsi Papua dan Papua Barat memiliki potensi sagu yang sangat besar. Sekitar 994.000 hektar yang sebagian besar merupakan hutan sagu alam terdapat di kedua provinsi ini. Pati sagu telah lama digunakan sebagai sumber nutrisi bagi penduduk asli papua. Pati sagu tidak hanya digunakan sebagai sumber karbohidrat, namun juga digunakan seba- gai bahan dasar industri kertas, plywood, hardbord, dan pangan. Pengolahan sagu secara tradisional yang dilakukan oleh masyarakat tidak efisien dan kapasitas produksinya sangat rendah. Peningkatan produksi dapat dilakukan dengan mengintroduksi peralatan pengolahan mekanis untuk merubah metode

  16. Application of fiber Bragg grating sensors in monitoring fatigue failure of NiTi rotary endodontic instruments

    Science.gov (United States)

    Liu, C. Y.; Shin, C. S.

    2012-04-01

    NiTi endodontic rotary instruments subjected to alternating tension and compression stress in root canals may fracture without prior warning. Once broken, extracting the fractured part from the canal is a difficult job and is annoying to both the patient and the dentist. Warning of an imminent fracture during clinical use will be a great help to avoid medical and legal complications. A monitoring system employing Fiber Bragg Grating (FBG) sensors has been attempted. The reason of using FBG is its small size which is very promising in integrating with the handpiece of the endodontic equipment. When cracking developed in an rotary instrument, we expect the natural vibration frequency of the instrument changes. If we can pick up the stress wave transmitted through the structural components of the rotary instruments, we may be able to detect the occurrence of a crack. In the current work, we found that we can successfully locate the operation period in the time domain by picking up and analyzing the sound wave using FBG. Furthermore, by employing Fast Fourier Transform (FFT) on the signal, we can reveal the energy variation and the frequency shifting phenomenon in specific section of frequency domain. For some characteristic frequencies, it was found that the energy and frequency varied in a well-defined pattern during the period of crack growth. It is hoped that with these information, the fatigue failure of rotary instruments can be closely monitored to avoid/alleviate the occurrence of unexpected fracture during clinical use.

  17. Integration of a zero dead-volume PDMS rotary switch valve in a miniaturised (bio)electroanalytical system

    DEFF Research Database (Denmark)

    Godino, Neus; del Campo, Francisco Javier; Munoz, Francesc Xavier

    2010-01-01

    This work features the design, fabrication and characterisation of a miniaturised electroanalytical lab on a chip that allows the performance of a complete bioassay, from the capture of magnetic particles through their functionalisation and sample incubation to the detection of electroactive reac......-based electrochemical bioassays, the concept of its rotary microreactor can be applied more broadly....

  18. Design Review Report for formal review of safety class features of exhauster system for rotary mode core sampling

    Energy Technology Data Exchange (ETDEWEB)

    JANICEK, G.P.

    2000-06-08

    Report documenting Formal Design Review conducted on portable exhausters used to support rotary mode core sampling of Hanford underground radioactive waste tanks with focus on Safety Class design features and control requirements for flammable gas environment operation and air discharge permitting compliance.

  19. Comparison of Single Visit Post Endodontic Pain Using Mtwo Rotary and Hand K-File Instruments: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Mohamad Kashefinejad

    2016-08-01

    Full Text Available Objectives: Pain is an unpleasant outcome of endodontic treatment that can be unbearable to patients. Instrumentation techniques may affect the frequency and intensity of post-endodontic pain. This study aimed to compare single visit post endodontic pain using Mtwo (NiTi rotary and hand K-file instruments.Materials and Methods: In this randomized controlled trial, 60 teeth with symptomatic irreversible pulpitis in 53 patients were selected and randomly assigned into two groups of 30 teeth. In group A, the root canals were prepared with Mtwo (NiTi rotary instruments. In group B, the root canals were prepared with hand K-file instruments. Pain assessment was implemented using visual analog scale (VAS at four, eight, 12 and 24 hours after treatment. The acquired data were analyzed using chi-square, Mann-Whitney U and Student’s t-test (P<0.05.Results: Patients treated with rotary instruments experienced significantly less post-endodontic pain than those treated with hand instruments (P<0.001.Conclusion: The use of Mtwo (NiTi rotary instruments in root canal preparation contributed to lower incidence of postoperative pain than hand K-files.

  20. Discussion of the results of the boundary-layer tests of an airfoil fitted with a rotary cylinder

    Science.gov (United States)

    Wolff, E B; Koning, C

    1927-01-01

    The results of the velocity measurements in the boundary layer described in NACA-TM 411 are here discussed in greater detail. The measurements made were of the velocity distribution in the vicinity of an airfoil model fitted with a rotary cylinder and were undertaken for the purpose of obtaining a closer insight into the phenomena observed in experimenting with this model.

  1. Effectiveness of Rotary Endodontic Instruments on Smear Layer Removal in Root Canals of Primary Teeth: A Scanning Electron Microscopy Study.

    Science.gov (United States)

    Subramaniam, Priya; Girish Babu, K L; Tabrez, T A

    2016-01-01

    The present SEM study was undertaken to evaluate the effect of root canal instrumentation using both manual and rotary files in the root canals of primary anterior teeth. Thirty freshly extracted primary maxillary incisors were divided into 3 groups of 10 teeth each. In Group I, root canals were instrumented with rotary NiTi files; in Group II, the root canals were instrumented using manual NiTi K files and; in Group III, manual instrumentation was done with stainless steel K files. Longitudinal sections were prepared and processed for observation under SEM at the coronal, middle and apical thirds. Scoring of smear layer was done according to Hulsmann and the data obtained was subjected to statistical analysis. Rotary files cleaned the coronal and middle thirds of root canals more effectively. Statistically there was no significant difference between the groups. Lowest score of 2.6 in the apical third of root canals was seen with hand NiTi files. Rotary instrumentation was as effective as manual instrumentation in removal of smear layer in the root canals of primary anterior teeth.

  2. Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 1: Reactor Design and Model Development

    KAUST Repository

    Zhao, Zhenlong

    2013-01-17

    Chemical-looping combustion (CLC) is a novel and promising technology for power generation with inherent CO2 capture. Currently, almost all of the research has been focused on developing CLC-based interconnected fluidized-bed reactors. In this two-part series, a new rotary reactor concept for gas-fueled CLC is proposed and analyzed. In part 1, the detailed configuration of the rotary reactor is described. In the reactor, a solid wheel rotates between the fuel and air streams at the reactor inlet and exit. Two purging sectors are used to avoid the mixing between the fuel stream and the air stream. The rotary wheel consists of a large number of channels with copper oxide coated on the inner surface of the channels. The support material is boron nitride, which has high specific heat and thermal conductivity. Gas flows through the reactor at elevated pressure, and it is heated to a high temperature by fuel combustion. Typical design parameters for a thermal capacity of 1 MW have been proposed, and a simplified model is developed to predict the performances of the reactor. The potential drawbacks of the rotary reactor are also discussed. © 2012 American Chemical Society.

  3. Mixing by rotary jet heads: Indications of the benefits of head rotation under turbulent and transitional flow conditions

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Vognsen, Marie; Nienow, Alfred W.

    2008-01-01

    Mixing times were obtained by the iodine-thiosulphate decolorization technique using rotary jet heads (RJH) for mixing in a Perspex tank with an inner diameter of 0.75 m and an aspect ratio of 2.5 using both water (turbulent flow) and shear-thinning, carboxymethyl cellulose (CMC) solutions (turbu...

  4. Production of rotary jet spun ultrathin fibers of poly-butylene adipate-co-terephthalate (PBAT) filled with nanocomposites

    Science.gov (United States)

    Andrade, P. O.; Santo, A. M. E.; Costa, M. M.; Lobo, A. O.

    2017-07-01

    Composite fibers of bioabsorbable poly-butylene adipate-co-terephthalate (PBAT) reinforced with superhydrophilic carbon nanotubes and hydroxyapatite nanocrystals were obtained by rotary jet spinning technique (RJS). The fibers were morphologically and biologically analyzed and found of potential use as scaffold for hard tissue engineering.

  5. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A VENTURI/PACKED COLUMN SCRUBBER - VOLUME II: APPENDICES

    Science.gov (United States)

    A 5-week series of pilot-scale incineration tests, employing a synthetic waste feed, was performed at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with a venturi scrubber/p...

  6. Post endodontic pain following single-visit root canal preparation with rotary vs reciprocating instruments: a meta-analysis of randomized clinical trials.

    Science.gov (United States)

    Hou, Xiao-Mei; Su, Zheng; Hou, Ben-Xiang

    2017-05-25

    In endodontic therapy, continuous rotary instrumentation reduced debris compared to reciprocal instrumentation, which might affect the incidence of post-endodontic pain (PP). The aim of our study was to assess whether PP incidence and levels were influenced by the choice of rotary or reciprocal instruments. In this meta-analysis the Pubmed and EM databases were searched for prospective clinical randomized trials published before April 20, 2016, using combinations of the keywords: root canal preparation/instrumentation/treatment/therapy; post-operative/endodontic pain; reciprocal and rotary instruments. Three studies were included, involving a total of 1,317 patients, 659 treated with reciprocating instruments and 658 treated with rotary instruments. PP was reported in 139 patients in the reciprocating group and 172 in the rotary group. The PP incidence odds ratio was 1.27 with 95% confidence interval (CI) (0.25, 6.52) favoring rotary instruments. The mild, moderate and severe PP levels odds ratios were 0.31 (0.11, 0.84), 2.24 (0.66, 7.59) and 11.71 (0.63, 218.15), respectively. No evidence of publication bias was found. Rotary instrument choice in endodontic therapy is associated with a lower incidence of PP than reciprocating instruments, while reciprocating instruments are associated with less mild PP incidence.

  7. Prospective case controlled clinical study of post-endodontic pain after rotary root canal preparation performed by a single operator.

    Science.gov (United States)

    Arias, Ana; de la Macorra, José C; Azabal, Magdalena; Hidalgo, Juan J; Peters, Ove A

    2015-03-01

    The aim of this study was to assess the influence of the shaping technique on incidence, intensity, duration and type of postoperative pain (PP). Root canal treatments were carried out with rotary instrumentation (n=80) during a single-visit, and data about pre-treatment conditions were collected. Patients were given a questionnaire to record the presence or absence of post-endodontic pain, its duration and level of discomfort. A matching patient (same pre-treatment conditions but manual instrumentation) was randomly selected from a pool (n = 374) and assigned to the control group. A total of 44 pairs of patients matched completely and were included in the study. Incidence (yes/no) of PP was assessed using Chi-square tests, intensity (mild, moderate, severe) with trend tests and duration (days) with Mann-Whitney U tests. A significantly greater proportion of the patients in the control group reported pain than did patients in the rotary shaping group (p < 0.05). However, pain duration was shorter (p = 0.008) in the control group. Differences in level of discomfort were not statistically significant. The results of this prospective in vivo study suggest that a higher incidence of PP should be expected after manual root canal preparation. However a second major finding of the study is that when present, PP after a rotary canal preparation is expected to last longer. There has been an increase in the use of rotary techniques among dentists in recent years. The present study analyses the differences in the incidence and characteristics of postoperative pain that should be expected after rotary canal preparation compared to traditional manual methods that had not been reported yet. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Fiber-matrix integrity, micromorphology and flexural strength of glass fiber posts: Evaluation of the impact of rotary instruments.

    Science.gov (United States)

    Pereira, Gabriel Kalil Rocha; Lançanova, Mateus; Wandscher, Vinicius Felipe; Kaizer, Osvaldo Bazzan; Limberger, Inácio; Özcan, Mutlu; Valandro, Luiz Felipe

    2015-08-01

    Several rotary instruments have been daily employed on clinic to promote cut aiming to adjust the length of fiber posts to the radicular conduct, but there is no information on the literature about the effects of the different rotary instruments and its impact on the micromorphology of surface and mechanical properties of the glass fiber post. This study aimed the impact of rotary instruments upon fiber-matrix integrity, micromorphology and flexural-strength of glass-fiber posts (GFP). GFP (N=110) were divided into 5 groups: Ctrl: as-received posts, DBc: coarse diamond-bur, DBff: extra-fine diamond-bur, CB: carbide-bur, DD: diamond-disc. Cutting procedures were performed under abundant irrigation. Posts exposed to rotary instruments were then subjected to 2-point inclined loading test (compression 45°) (n=10/group) and 3-point flexural-strength test (n=10/group). Fiber-matrix integrity and micromorphology at the cut surface were analyzed using a SEM (n=2/group). Cutting procedures did not significantly affect the 2-point (51.7±4.3-56.7±5.1 MPa) (p=0.0233) and 3-point flexural-strength (671.5±35.3-709.1±33.1 MPa) (p=0.0968) of the posts (One-way ANOVA and Tukey׳s test). Fiber detachment was observed only at the end point of the cut at the margins of the post. Cut surfaces of the CB group were smoother than those of the other groups. After 3-point flexural strength test, fiber-matrix separation was evident at the tensile side of the post. Rotary instruments tested with simultaneous water-cooling did not affect the resistance of the tested fiber posts but caused disintegration of the fibers from the matrix at the end of the cut, located at the margins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. A rotary drum screen with internal screw flights for Eri silkworm pupae

    Directory of Open Access Journals (Sweden)

    Kanjanawanishkul Kiattisin

    2015-01-01

    Full Text Available Eri silkworm pupae (Samia ricini are very interesting creatures since they can be developed as a sustainable high protein food source for human beings and animals, and their cocoons can be used for silk production. At present, Thai silk is very famous for its special qualities, whereas the requirement of pupae as food grows increasingly, in particular, canned pupae with seasoning favors. Like other food products, size uniformity is required. Therefore, in this paper, a rotary drum screen with internal screw flights was designed and constructed for separating Eri silkworm pupae into two groups with different sizes. The experiments were conducted to evaluate its effectiveness. The results show that the optimal angular speed of the screen was 20 rpm and the screw pitch value was 10 cm. These parameters resulted in the accuracy percentage of pupa screening of 94.3% and the working capacity of 8.6 kg/h.

  10. Bacterial cellulose production by Gluconacetobacter sp. PKY5 in a rotary biofilm contactor.

    Science.gov (United States)

    Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

    2007-04-01

    A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

  11. Numerical Modelling and Damage Assessment of Rotary Wing Aircraft Cabin Door Using Continuum Damage Mechanics Model

    Science.gov (United States)

    Boyina, Gangadhara Rao T.; Rayavarapu, Vijaya Kumar; V. V., Subba Rao

    2017-02-01

    The prediction of ultimate strength remains the main challenge in the simulation of the mechanical response of composite structures. This paper examines continuum damage model to predict the strength and size effects for deformation and failure response of polymer composite laminates when subjected to complex state of stress. The paper also considers how the overall results of the exercise can be applied in design applications. The continuum damage model is described and the resulting prediction of size effects are compared against the standard benchmark solutions. The stress analysis for strength prediction of rotary wing aircraft cabin door is carried out. The goal of this study is to extend the proposed continuum damage model such that it can be accurately predict the failure around stress concentration regions. The finite element-based continuum damage mechanics model can be applied to the structures and components of arbitrary configurations where analytical solutions could not be developed.

  12. Assessment of Root Canal Enlargement Using Mtwo and BioRace Rotary Files

    Directory of Open Access Journals (Sweden)

    Enzo Cumbo

    2015-01-01

    Full Text Available Objective. To evaluate root canal enlargement following mechanical shaping using 2 nickel titanium rotary systems. Material and Methods. Forty single-rooted teeth were immersed in resin and sectioned perpendicular to the long axis at 4, 8, and 12 mm from the apex. Digital capture of sections was performed before and after canal instrumentation using Mtwo and BioRace instruments. The area increase of endodontic space was calculated by subtraction. Results. The use of both instruments has allowed the removal of great amounts of dentin from the canal walls, even when the endodontic morphology is characterized by awkwardness to reach recesses. Conclusions. Both procedures seem to be valid and no differences were found between Mtwo and BioRaCe considering the amount of dentin removed at different distances from the apex.

  13. State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach.

    Science.gov (United States)

    Yu, Jue; Zhuang, Jian; Yu, Dehong

    2015-01-01

    This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Effect of Relative Velocity Between Rough Surfaces: Hydrodynamic Lubrication of Rotary Lip Seal

    Science.gov (United States)

    Lahjouji, I.; Gadari, M. El; Fahime, B. El; Radouani, M.

    2017-05-01

    Since the sixties, most of numerical studies that model the rotary lip seal lubrication have been restricted by assuming that one of the two opposing surfaces is smooth: either the lip or the shaft. This hypothesis, although it is verified only for a shaft roughness ten times smaller than that of the seal, is the best solution to avoid the transient term "∂h/∂t" in the deterministic approach. Thus, the subject of the present study is twofold. The first part validates the current hydrodynamic model with the international literature by assuming the asperities on the lip and shaft as a two-dimensional cosine function. In the second part the Reynolds equation for rough surfaces with relative motion is solved. The numerical results show that the relative motion between rough surfaces impacts significantly the load support and the leakage rate, but affects slightly the friction torque.

  15. Irreversibility analysis of magneto-hydrodynamic nanofluid flow injected through a rotary disk

    Directory of Open Access Journals (Sweden)

    Rashidi Mohammad Mehdi

    2015-01-01

    Full Text Available The non-linear Navier-Stokes equations governed on the nanofluid flow injected through a rotary porous disk in the presence of an external uniform vertical magnetic field can be changed to a system of non-linear partial differential equations by applying similar parameter. In this study, partial differential equations are analytically solved by the modified differential transform method, Pade differential transformation method to obtain self-similar functions of motion and temperature. A very good agreement is observed between the obtained results of Pade differential transformation method and those of previously published ones. Then it has become possible to do a comprehensive parametric analysis on the entropy generation in this case to demonstrate the effects of physical flow parameters such as magnetic interaction parameter, injection parameter, nanoparticle volume fraction, dimensionless temperature difference, rotational Brinkman number and the type of nanofluid on the problem.

  16. Vibration Energy Harvesting on Vehicle Suspension Using Rotary and Linear Electromagnetic Generator

    Directory of Open Access Journals (Sweden)

    Arif Indro Sultoni

    2013-04-01

    Full Text Available In this paper, we discuss comparation of vehicle vibration energy harvesting between rotary and linear electromagnetic generator. We construct the two model of energy harvester mechanism and then analyze both of energy absorbtion and vehicle comfortability. Furthermore, we analyze both of energy absorbtion and vehicle comfortability. Vehicle is modeled as quarter car. Rotarty generator harvests 2.5 x 10-4 Watt. The other hand, linear generator has viscous characteristic and capable to generates 90 Watts with 12 Volt power supply for 0.03 m amplitude of bumpy road input. Linear generator reduces oscillation with 1.2 sec settling time. It is more comfort than the angular which has 3 sec in settling time. With unnevenees road input, mean power of this generator is 64 Watt.

  17. Application of a self-compensation mechanism to a rotary-laser scanning measurement system

    Science.gov (United States)

    Guo, Siyang; Lin, Jiarui; Ren, Yongjie; Shi, Shendong; Zhu, Jigui

    2017-11-01

    In harsh environmental conditions, the relative orientations of transmitters of rotary-laser scanning measuring systems are easily influenced by low-frequency vibrations or creep deformation of the support structure. A self-compensation method that counters this problem is presented. This method is based on an improved workshop Measurement Positioning System (wMPS) with inclinometer-combined transmitters. A calibration method for the spatial rotation between the transmitter and inclinometer with an auxiliary horizontal reference frame is presented. It is shown that the calibration accuracy can be improved by a mechanical adjustment using a special bubble level. The orientation-compensation algorithm of the transmitters is described in detail. The feasibility of this compensation mechanism is validated by Monte Carlo simulations and experiments. The mechanism mainly provides a two-degrees-of-freedom attitude compensation.

  18. Microstructure Evolution of Ni-Based ODS Superalloy Powders During Horizontal Rotary Ball Milling

    Directory of Open Access Journals (Sweden)

    Lee H.-E.

    2017-06-01

    Full Text Available Microstructure evolution of Ni-based oxide dispersion-strengthened alloy powders with milling time is investigated. The elemental powders having a nominal composition of Ni-15Cr-4.5Al-4W-2.5Ti-2Mo-2Ta-0.15Zr-1.1Y2O3 in wt % were ball-milled by using horizontal rotary ball milling with the change of milling velocity. Microstructure observation revealed that large aggregates were formed in the early stages of ball milling, and further milling to 5 h decreased particle size. The average crystalline size, estimated by the peak broadening of XRD, decreased from 28 nm to 15 nm with increasing milling time from 1 h to 5 h. SEM and EPMA analysis showed that the main elements of Ni and Cr were homogeneously distributed inside the powders after ball milling of 5 h.

  19. Cold Snapshot of a Molecular Rotary Motor Captured by High‐Resolution Rotational Spectroscopy

    Science.gov (United States)

    Domingos, Sérgio R.; Cnossen, Arjen; Buma, Wybren J.; Browne, Wesley R.; Feringa, Ben L.

    2017-01-01

    Abstract We present the first high‐resolution rotational spectrum of an artificial molecular rotary motor. By combining chirped‐pulse Fourier transform microwave spectroscopy and supersonic expansions, we captured the vibronic ground‐state conformation of a second‐generation motor based on chiral, overcrowded alkenes. The rotational constants were accurately determined by fitting more than 200 rotational transitions in the 2–4 GHz frequency range. Evidence for dissociation products allowed for the unambiguous identification and characterization of the isolated motor components. Experiment and complementary quantum‐chemical calculations provide accurate geometrical parameters for the C27H20 molecular motor, the largest molecule investigated by high‐resolution microwave spectroscopy to date. PMID:28556402

  20. A novel rotary reactor configuration for simultaneous production of hydrogen and carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Pinilla, J.L.; Utrilla, R.; Lazaro, M.J.; Suelves, I.; Moliner, R. [Instituto de Carboquimica CSIC, Miguel Luesma 4, 50018 Zaragoza (Spain); Palacios, J.M. [Instituto de Catalisis y Petroleoquimica CSIC, Cantoblanco, Marie Curie 2, 28049-Madrid (Spain)

    2009-10-15

    A novel reactor configuration, a rotary bed reactor (RBR), was used to study at large scale production the Catalytic Decomposition of Methane (CDM) into hydrogen and carbon nanofibers using a nickel-copper catalyst. The results were compared to those obtained in a fluidized bed reactor (FBR) under the same operating conditions. Tests carried out in the RBR provided higher hydrogen yields and more sustainable catalyst performance in comparison to the FBR. Additionally, the effect of the rotation speed and reaction temperature on the performance in the RBR of the nickel-copper catalyst was studied. The textural and structural properties of the carbon nanofibers produced were also studied by means of N{sub 2} adsorption, SEM and XRD, and compared to those obtained in the FBR set-up under the same operating conditions. (author)

  1. Experimental calibration of forward and inverse neural networks for rotary type magnetorheological damper

    DEFF Research Database (Denmark)

    Bhowmik, Subrata; Weber, Felix; Høgsberg, Jan Becker

    2013-01-01

    This paper presents a systematic design and training procedure for the feed-forward backpropagation neural network (NN) modeling of both forward and inverse behavior of a rotary magnetorheological (MR) damper based on experimental data. For the forward damper model, with damper force as output...... an optimization procedure demonstrates accurate training of the NN architecture with only current and velocity as input states. For the inverse damper model, with current as output, the absolute value of velocity and force are used as input states to avoid negative current spikes when tracking a desired damper...... force. The forward and inverse damper models are trained and validated experimentally, combining a limited number of harmonic displacement records, and constant and half-sinusoidal current records. In general the validation shows accurate results for both forward and inverse damper models, where...

  2. Mathematical modelling of a thin layer drying of apricots in a solar energized rotary dryer

    Energy Technology Data Exchange (ETDEWEB)

    Akpinar, E.K.; Yildiz, C. [Firat Univ., Elazig (Turkey). Dept. of Mechanical Engineering; Sarsilmaz, C. [Firat Univ., Elazig (Turkey). Dept. of Mechanical Education

    2004-07-01

    In this paper we present a mathematical modelling of a thin layer forced solar drying of apricots. An indirect forced convection solar dryer consisting of a solar heater and a rotary column cylindrical drying (RCCD) cabinet was used in the experiments. Air heated by the solar air heater was forced through the apricots by an electrical fan. Moreover, the natural sun drying experiments were conducted for the comparison at the same time. Fourteen different thin layer mathematical drying models were compared according to their coefficients of determination (r,{chi}{sup 2}, RMSE) to estimate solar drying curves. The effects of the drying air temperature, velocity and the rotation speed of column on the drying model constants and coefficients were predicted by multiple regressions using a linear type model. (Author)

  3. Standard guide for conducting wear tests using a rotary platform, double-head abraser

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This guide covers and is intended to assist in establishing procedures for conducting wear tests of rigid or flexible materials utilizing the rotary platform, double-head abraser (RPDH). 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 Exception—English units are used when determining coating thickness. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Study on the marine ejector refrigeration-rotary desiccant air-conditioning system

    Science.gov (United States)

    Zheng, C. Y.; Zheng, G. J.; Yu, W. S.; Chen, W.

    2017-08-01

    A newly developed ejector refrigeration-rotary desiccant air-conditioning (ERRD A/C) system is proposed to recover ship waste heat as far as possible. Its configuration is built firstly, then its advantages are analyzed, after that, with the help of psychrometric chart, some important parameters such as power consumption, steam consumption and COP of ERRD A/C system are calculated theoretically under design conditions of a real marine A/C, and comparative analysis with conventional A/C is deployed. The results show that the power consumption of ERRD A/C system is only 32.87% of conventional A/C, which meant that ERRD A/C system has potential to make full use of ship waste heat to realize energy saving and environmental protection when using green refrigerant such as water.

  5. Application of a Fault Detection and Isolation System on a Rotary Machine

    Directory of Open Access Journals (Sweden)

    Silvia M. Zanoli

    2013-01-01

    Full Text Available The paper illustrates the design and the implementation of a Fault Detection and Isolation (FDI system to a rotary machine like a multishaft centrifugal compressor. A model-free approach, that is, the Principal Component Analysis (PCA, has been employed to solve the fault detection issue. For the fault isolation purpose structured residuals have been adopted while an adaptive threshold has been designed in order to detect and to isolate the faults. To prove the goodness of the proposed FDI system, historical data of a nitrogen centrifugal compressor employed in a refinery plant are considered. Tests results show that detection and isolation of single as well as multiple faults are successfully achieved.

  6. Haptic Addition to a Visual Menu Selection Interface Controlled by an In-Vehicle Rotary Device

    Directory of Open Access Journals (Sweden)

    Camilla Grane

    2012-01-01

    Full Text Available Today, several vehicles are equipped with a visual display combined with a haptic rotary device for handling in-vehicle information system tasks while driving. This experimental study investigates whether a haptic addition to a visual interface interferes with or supports secondary task performance and whether haptic information could be used without taking eyes off road. Four interfaces were compared during simulated driving: visual only, partly corresponding visual-haptic, fully corresponding visual-haptic, and haptic only. Secondary task performance and subjective mental workload were measured. Additionally, the participants were interviewed. It was found that some haptic support improved performance. However, when more haptic information was used, the results diverged in terms of task completion time and interface comprehension. Some participants did not sense all haptics provided, some did not comprehend the correspondence between the haptic and visual interfaces, and some did. Interestingly, the participants managed to complete the tasks when using haptic-only information.

  7. Ideal Thermodynamic Cycle Analysis for the Meletis-Georgiou Vane Rotary Engine Concept

    Directory of Open Access Journals (Sweden)

    Demos P. Georgiou

    2010-01-01

    Full Text Available The Meletis-Georgiou is a patented Vane Rotary Engine concept that incorporates separate compression-expansion chambers and a modified Otto (or Miller cycle, characterized by (Exhaust Gas Recirculation at elevated pressures. This is implemented by transferring part of the expansion chamber volume into the compression one through the coordinated action of two vane diaphragms. This results into a very high gas temperature at the end of the compression, something that permits autoignition under all conditions for a Homogeneous Compression Ignition (HCCI version of the engine. The relevant parametric analysis of the ideal cycle shows that the new cycle gives ideal thermal efficiencies of the order of 60% to 70% under conditions corresponding to homogeneous compression engines but at reduced pressures when compared against the corresponding Miller cycle.

  8. Method and apparatus for maximizing throughput of indirectly heated rotary kilns

    Science.gov (United States)

    Coates, Ralph L; Smoot, Douglas L.; Hatfield, Kent E

    2016-06-21

    An apparatus and method for achieving improved throughput capacity of indirectly heated rotary kilns used to produce pyrolysis products such as shale oils or coal oils that are susceptible to decomposition by high kiln wall temperatures is disclosed. High throughput is achieved by firing the kiln such that optimum wall temperatures are maintained beginning at the point where the materials enter the heating section of the kiln and extending to the point where the materials leave the heated section. Multiple high velocity burners are arranged such that combustion products directly impact on the area of the kiln wall covered internally by the solid material being heated. Firing rates for the burners are controlled to maintain optimum wall temperatures.

  9. Risk reduction measures for the development of biomass rotary kiln gasification

    Energy Technology Data Exchange (ETDEWEB)

    Howson, J.H.; Casnello, K.

    2002-07-01

    This report summarises the results of a project aiming to reduce the risks associated with the design and operation of a rotary kiln for gasifying biomass. The work was carried out at the CPL Flimby Plant with the objectives of examining gas yields from wood gasification and the impact of steam and gas on the process, as well as developing a mathematical model for the prediction of the performance of the feedstock under different gasifier conditions. The modifications to plant to convert it to a biomass gasification plant prior to the trials are described, and the use of the mathematical model to predict the gas yields and composition from the wood feedstock and calculate the heating requirements are discussed.

  10. Rotary bending fatigue properties of Inconel 718 alloys by ultrasonic nanocrystal surface modification technique

    Directory of Open Access Journals (Sweden)

    Jun-Hyong Kim

    2015-08-01

    Full Text Available This study investigates the influence of ultrasonic nanocrystal surface modification (UNSM technique on fatigue properties of SAE AMS 5662 (solution treatment of Inconel 718 alloys. The fatigue properties of the specimens were investigated using a rotary bending fatigue tester. Results revealed that the UNSM-treated specimens showed longer fatigue life in comparison with those of the untreated specimens. The improvement in fatigue life of the UNSM-treated specimens is attributed mainly to the induced compressive residual stress, increased hardness, reduced roughness and refined grains at the top surface. Fractured surfaces were analysed using a scanning electron microscopy (SEM in order to give insight into the effectiveness of UNSM technique on fracture mechanisms and fatigue life.

  11. Increasing the lining life of rotary kilns in firing of magnesite

    Energy Technology Data Exchange (ETDEWEB)

    Simonov, K.V.; Bocharov, L.D.; Koptelov, V.N.; Ravochkin, S.I.; Nazmutdinov, R.S.

    1988-09-01

    The intensity of wear of chrome-magnesite and magnesite-chromite parts in the sintering zones of rotary kilns is determined by the formation on the kiln lining of a protective layer. In the normal method of firing of magnesite without additions a thin layer of periclase-forsterite and periclase-monticellite with high porosity and low strength is formed. Such a layer cannot reliably protect the kiln lining from wear. A more resistant protective coating is formed on the lining with the addition of siderite. Investigation of the grains of sintered siderite under the microscope showed that they consist of finely dispersed magnesioferrite and magnetite, possess magnetizability, and in polished specimens are transparent and strongly fissured. The formation of the protective layer on the sintering zone lining with the addition of siderite makes it possible to increase the kiln lining life by 20-30% and to increase the output of magnesite powders without loss of quality.

  12. Development of a plastic rotary heat exchanger for room-based ventilation in existing apartments

    DEFF Research Database (Denmark)

    Smith, Kevin Michael; Svendsen, Svend

    2015-01-01

    for single-room ventilation based on thermal design theory. Performance is predicted from correlations of dimensionless groups for regenerative heat exchangers, and this guides the selection of a polycarbonate honeycomb with small circular channels. Experiments quantify flows and determine temperature......The existing building stock will likely undergo widespread energy renovations to meet future emissions targets. Single-room ventilation may enable the process due to its simple installation, low fan power, and potential for local heat recovery. A short plastic rotary heat exchanger is developed...... efficiencies at several ventilation rates while accounting for heat gains from motors and air leakage. The measured and modelled temperature efficiencies show adequate agreement and exceed 80% for a balanced nominal ventilation rate of 28m3/h. This result meets the development criteria but cannot validate...

  13. Motor Bourn Magnetic Noise Filtering for Magnetometers in Micro-Rotary Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Nathan J. UNWIN

    2015-10-01

    Full Text Available Avionics systems of micro aerial vehicles (MAV pose unique problems in system design, sensor signal handling and control. This is evident in micro-rotary aircraft as their whole body rotates with the sensors of the flight control. The precise calculation of attitude and heading from magnetometer readings is complex due to the body rotation. It is made even more difficult by noise induced in the geomagnetic signal by fluctuating magnetic field of the closely positioned motors. Filtering that noise is challenging since the rotation speed of motors and the vehicle can be very close. This paper presents analysis of motor induced noise, based on experimental data of brushless micro motors. A novel time domain filter is proposed, designed, implemented in FPGA hardware, tested and compared to other filters. This filter provides good performance even when the rotational rate of the motor and vehicle are close and traditional frequency domain filters would perform poorly.

  14. Preliminary study on rotary ultrasonic machining of CFRP/Ti stacks.

    Science.gov (United States)

    Cong, W L; Pei, Z J; Treadwell, C

    2014-08-01

    Reported drilling methods for CFRP/Ti stacks include twist drilling, end milling, core grinding, and their derived methods. The literature does not have any report on drilling of CFRP/Ti stacks using rotary ultrasonic machining (RUM). This paper, for the first time, reports a study on drilling of CFRP/Ti stacks using RUM. It also compares results on drilling of CFRP/Ti stacks using RUM with reported results on drilling of CFRP/Ti stacks using other methods. When drilling CFRP/Ti stacks using RUM, cutting force, torque, and CFRP surface roughness were lower, hole size variation was smaller, CFRP groove depth was smaller, tool life was longer, and there was no obvious Ti exit burr and CFRP entrance delamination. Ti surface roughness when drilling of CFRP/Ti stacks using RUM was about the same as those when using other methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Investigations on the critical feed rate guaranteeing the effectiveness of rotary ultrasonic machining.

    Science.gov (United States)

    Wang, Jianjian; Feng, Pingfa; Zhang, Jianfu; Cai, Wanchong; Shen, Hao

    2017-02-01

    Rotary ultrasonic machining (RUM) is a well-known and efficient method for manufacturing holes in brittle materials. RUM is characterized by improved material removal rates, reduced cutting forces and reduced edge chipping sizes at the hole exit. The aim of this study is to investigate the critical feed rate to guarantee the effectiveness of RUM. Experimental results on quartz glass and sapphire specimens show that when the feed rate exceeds a critical value, the cutting force increases abruptly, accompanied by a significant decrease of ultrasonic amplitude. An analytical model for the prediction of critical feed rates is presented, based on indentation fracture mechanic and the theory of impact of vibrating systems. This model establishes the theoretical relationships between the critical feed rate, idling resonant ultrasonic amplitude and spindle speed. The results predicted by the analytical model were in good agreement with the experimental results. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. INITIAL ASSESSMENT OF SURFACE PRESSURE CHARACTERISTICS OF TWO ROTARY WING UAV DESIGNS

    Science.gov (United States)

    Jones, Henry E.; Wong, Oliver D.; Watkins, A. Neal; Noonan, Kevin W.; Reis, Deane G.; Malovrh, Brendon D.; Ingram, Joanne L.

    2006-01-01

    This paper presents results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of fixed system pressure coefficient response to changes in configuration attitude and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect the magnitude of the response. Pressure coefficients were measured using both conventional pressure taps and via pressure sensitive paint. Comparisons between the two methods are presented and demonstrate that the pressure sensitive paint is a promising method; however, further work on the technique is required.

  17. Launching automated rotary parking system: Towards traffic congestion free Dhaka city

    Science.gov (United States)

    Islam, Mohummad Shariful; Tithi, Afshana Morshed; Hossain, Farzad; Shetu, Rifat Sultana; Amin, S. M. Abdullah Al; Chowdhury, Shakia Zannatul Ferdous

    2017-12-01

    Bangladesh is the most densely populated city in the whole world, which is visible more in the capital city Dhaka. People have to suffer and valuable times are being wasted for this chronic quandary. Lack of proper planning of the city, different speed vehicles on the same road, over population, inadequate road space, unplanned stoppage or parking etc. are responsible for causing the traffic congestion in Dhaka City. Among those insufficient/unplanned parking system is one of the main reasons for causing traffic congestion. The automated rotary car parking system is the best and suitable because of its less utilization of space compared to other systems. It is a friendly parking system due to the non-utilization of noise/pollution related mechanism. The aim of this paper is to develop an automated car parking system with a minimum cost for reducing congestion in Dhaka city.

  18. Analysis of Surface and Subsurface Damage Morphology in Rotary Ultrasonic Machining of BK7 Glass

    Science.gov (United States)

    Hong-xiang, Wang; Chu, Wang; Jun-liang, Liu; Shi, Gao; Wen-Jie, Zhai

    2017-11-01

    This paper investigates the formation process of surface/subsurface damage in the rotary ultrasonic machining of BK7 glass. The results show that during the milling using the end face of the tool, the cutting depth and the residual height between the abrasive grains constantly change with the high-frequency vibration, generating lots of cracks on both sides of the scratches. The high-frequency vibration accelerates the chips falling from the surface, so that the chips and thermal damage are reduced, causing the grinding surface quality better. A plastic deformation area is formed during the grinding, due to the non-uniform cutting force on the material surface, and the residual stress is produced in the deformation area, inducing the median/lateral cracks.

  19. Method and apparatus for maximizing throughput of indirectly heated rotary kilns

    Science.gov (United States)

    Coates, Ralph L; Smoot, L. Douglas; Hatfield, Kent E

    2012-10-30

    An apparatus and method for achieving improved throughput capacity of indirectly heated rotary kilns used to produce pyrolysis products such as shale oils or coal oils that are susceptible to decomposition by high kiln wall temperatures is disclosed. High throughput is achieved by firing the kiln such that optimum wall temperatures are maintained beginning at the point where the materials enter the heating section of the kiln and extending to the point where the materials leave the heated section. Multiple high velocity burners are arranged such that combustion products directly impact on the area of the kiln wall covered internally by the solid material being heated. Firing rates for the burners are controlled to maintain optimum wall temperatures.

  20. Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill

    Science.gov (United States)

    Sherrit, Stewart (Inventor); Bao, Xiaoqi (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor)

    2014-01-01

    A Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill includes a horn actuator having high power piezoelectric materials and a flexure pre-stress to increase the actuators effectiveness. The drill is a low mass, low power, compact coring drill measuring 20-cm high by 7-cm diameter and having a total weight of 2 kg including drive electronics. Using an average power of 50-Watts, the drill basalt is expected to cut basalt at a rate of 0.2 cm/min down to depth of 10-cm and create cuttings and an intact core. The drill is expected to operate under different environments including Martian ambient (6 Torr and down to -50 degree C), and liquid nitrogen temperatures (77 K) and low pressure (<<1 Torr) to simulate lunar polar and Europa conditions. Materials expected to be sampled include Kaolinite, Saddleback Basalt, Limestone, Volcanic Breccia, Siltstone, ice, permafrost and layered rocks with different hardness.

  1. Composting domestic sewage sludge with natural zeolites in a rotary drum reactor.

    Science.gov (United States)

    Villaseñor, J; Rodríguez, L; Fernández, F J

    2011-01-01

    This work aimed the influence of zeolites addition on a sludge-straw composting process using a pilot-scale rotary drum reactor. The type and concentration of three commercial natural zeolites were considered: a mordenite and two clinoptilolites (Klinolith and Zeocat). Mordenite caused the greatest carbon removal (58%), while the clinoptilolites halved losses of ammonium. All zeolites removed 100% of Ni, Cr, Pb, and significant amounts (more than 60%) of Cu, Zn and Hg. Zeocat displayed the greatest retention of ammonium and metals, and retention efficiencies increased as Zeocat concentration increased. The addition of 10% Zeocat produced compost compliant with Spanish regulations. Zeolites were separated from the final compost, and leaching studies suggested that zeolites leachates contained very low metals concentrations (zeolites could be separated from the compost prior to application. The different options have been discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Design of Rotary Atomizer Using Characteristics of Thin Film Flow on Solid Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Park, Boo Seong; Kim, Bo Hung [Univ. of Ulsan, Ulsan (Korea, Republic of)

    2013-12-15

    A disc-type rotary atomizer affords advantages such as superior paint transfer efficiency, uniformity of paint pattern and particle size, and less consumption of compressed air compared to a spray-gun-type atomizer. Furthermore, it can be applied to all types of painting materials, and it is suitable for large-scale processes such as car painting. The painting quality, which is closely related to the atomizer performance, is determined by the uniformity and droplet size in accordance with the design of the bell disc surface. This study establishes the basics of how to design a surface by modeling the operating bell disc's RPM, diameter, surface angle, and film thickness considering dye characteristics such as the viscosity, density, and surface affinity.

  3. New Concepts and Perspectives on Micro-Rotorcraft and Small Autonomous Rotary-Wing Vehicles

    Science.gov (United States)

    Young, Larry A.; Aiken, E. W.; Johnson, J. L.; Demblewski, R.; Andrews, J.; Aiken, Irwin W. (Technical Monitor)

    2001-01-01

    A key part of the strategic vision for rotorcraft research as identified by senior technologists within the Army/NASA Rotorcraft Division at NASA Ames Research Center is the development and use of small autonomous rotorcraft. Small autonomous rotorcraft are defined for the purposes of this paper to be a class of vehicles that range in size from rotary-wing micro air vehicles (MAVs) to larger, more conventionally sized, rotorcraft uninhabited aerial vehicles (UAVs) - i.e. vehicle gross weights ranging from hundreds of grams to thousands of kilograms. The development of small autonomous rotorcraft represents both a technology challenge and a potential new vehicle class that will have substantial societal impact for: national security, personal transport, planetary science, and public service.

  4. Continuous Production of IF-WS2 Nanoparticles by a Rotary Process

    Directory of Open Access Journals (Sweden)

    Fang Xu

    2014-06-01

    Full Text Available This manuscript demonstrates the design, modification and initial investigation of a rotary furnace for the manufacturing of inorganic fullerene WS2 nanoparticles. Different preparation methods starting with various precursors have been investigated, of which the gas-solid reaction starting with WO3 nanoparticles was the most efficient technique. Furthermore, the influence of temperature, reaction time, and reaction gases etc. on the synthesis of inorganic fullerene WS2 nanomaterials was investigated, and these parameters were optimised based on combined characterisations using XRD, SEM and TEM. In addition, the furnace was further modified to include a baffled tube, a continuous gas-blow feeding system, and a collection system, in order to improve the batch yield and realise continuous production. This technique has improved the production from less than 1 g/batch in a traditional tube furnace to a few tens of g/batch, and could be easily scaled up to industry level production.

  5. [Preparation of crocin from gardenia yellow pigment by slow rotary countercurrent chromatography].

    Science.gov (United States)

    Jiang, Zhiguo; Chen, Wenxue; Liu, Sixin; Du, Qizhen

    2011-03-01

    A method was established for the preparation of crocin from gardenia yellow pigment by slow rotary countercurrent chromatography (SRCCC). A two-phase solvent system consisting of methyl tert-butyl ether, n-butanol, acetonitrile and water (2 : 2. 5 : 1 : 5, v/v/v/v) was used. The upper phase was used as the stationary phase, and the lower phase as the mobile phase. By SRCCC elution, 2.47 g of crocin with a purity of 96.8% was obtained from 5 g of gardenia yellow pigment at a flow rate of 5 mL/min and a rotation speed of 50 r/min. The results indicated that SRCCC is a powerful technique for the purification of crocin from gardenia yellow pigment with high preparative capacity, high safety and high efficiency in resolution, and it is possible to prepare crocin at industrial level by SRCCC.

  6. Interrogation of fibre Bragg gratings through a fibre optic rotary joint on a geotechnical centrifuge

    Science.gov (United States)

    Correia, Ricardo; James, Stephen W.; Marshall, Alec; Heron, Charles; Korposh, Sergiy

    2016-05-01

    The monitoring of an array of fibre Bragg gratings (FBGs) strain sensors was performed through a single channel, single mode fibre optic rotary joint (FORJ) mounted on a geotechnical centrifuge. The array of three FBGs was attached to an aluminum plate that was anchored at the ends and placed on the model platform of the centrifuge. Acceleration forces of up to 50g were applied and the reflection signal of the monitored FBGs recorded dynamically using a 2.5kHz FBG interrogator placed outside the centrifuge. The use of a FORJ allowed the monitoring of the FBGs without submitting the FBG interrogator to the high g-forces experienced in the centrifuge.

  7. The control of drilling vibrations: A coupled PDE-ODE modeling approach

    Directory of Open Access Journals (Sweden)

    Saldivar Belem

    2016-06-01

    Full Text Available The main purpose of this contribution is the control of both torsional and axial vibrations occurring along a rotary oilwell drilling system. The model considered consists of a wave equation coupled to an ordinary differential equation (ODE through a nonlinear function describing the rock-bit interaction. We propose a systematic method to design feedback controllers guaranteeing ultimate boundedness of the system trajectories and leading consequently to the suppression of harmful dynamics. The proposal of a Lyapunov-Krasovskii functional provides stability conditions stated in terms of the solution of a set of linear and bilinear matrix inequalities (LMIs, BMIs. Numerical simulations illustrate the efficiency of the obtained control laws.

  8. Auto-Gopher: a wire-line rotary-hammer ultrasonic drill

    Science.gov (United States)

    Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Bar-Cohen, Yoseph; Chen, Beck

    2011-04-01

    Developing technologies that would enable NASA to sample rock, soil, and ice by coring, drilling or abrading at a significant depth is of great importance for a large number of in-situ exploration missions as well as for earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for records of past and present life on the planet, as well as the search of water and other resources. A deep corer, called Auto-Gopher, is currently being developed as a joint effort of the JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher is a wire-line rotary- hammer drill that combines rock breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) that has been developed as an adaptable tool for many of drilling and coring applications. The USDC uses an intermediate free-flying mass to transform the high frequency vibrations of the horn tip into a sonic hammering of a drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher. The lessons learned from testing the ice gopher were implemented into the design of the Auto-Gopher by inducing a rotary motion onto the fluted coring bit. A wire-line version of such a system would allow penetration of significant depth without a large increase in mass. A laboratory version of the corer was developed in the NDEAA lab to determine the design and drive parameters of the integrated system. The design configuration lab version of the design and fabrication and preliminary testing results are presented in this paper.

  9. Auto-Gopher-II: an autonomous wireline rotary-hammer ultrasonic drill

    Science.gov (United States)

    Badescu, Mircea; Lee, Hyeong Jae; Sherrit, Stewart; Bao, Xiaoqi; Bar-Cohen, Yoseph; Jackson, Shannon; Chesin, Jacob; Zacny, Kris; Paulsen, Gale L.; Mellerowicz, Bolek; Kim, Daniel

    2017-04-01

    Developing technologies that would enable future NASA exploration missions to penetrate deeper into the subsurface of planetary bodies for sample collection is of great importance. Performing these tasks while using minimal mass/volume systems and with low energy consumption is another set of requirements imposed on such technologies. A deep drill, called Auto-Gopher II, is currently being developed as a joint effort between JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher II is a wireline rotary-hammer drill that combines formation breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted auger bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed as an adaptable tool for many drilling and coring applications. The USDC uses an intermediate free-flying mass to transform high frequency vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher and then integrated into a rotary hammer device to develop the Auto-Gopher-I. The lessons learned from these developments are being integrated into the development of the Auto- Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics. Subsystems of the wireline drill are being developed in parallel at JPL and Honeybee Robotics Ltd. This paper presents the development efforts of the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.

  10. Continuous pyrolysis of biomass feedstocks in rotary kiln convertors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Henry, Jr, H. H.; Kimzey, J. R.; Turpin, J. L.; MacCallum, R. N.

    1979-08-30

    The biomass research program at the University of Arkansas has developed three experimental projects or tasks for the attainment of its objectives. They are: (1) utilization of the existing full scale convertor for testing and data acquisition at Jonesboro, Arkansas; (2) development of a scale model rotary pyrolytic convertor (bench scale research kiln); and (3) development of analytical laboratory services for the analysis of feedstocks and products, and for basic pyrolytic process studies. The project at Jonesboro, Arkansas, which aimed at testing the Angelo convertor concept through heat and material balances over the available range of operations, could not completely achieve this objective because of the severe mechanical and structural deficiencies in the full scale convertor. A limited number of data have been taken in spite of the deficiencies of the machine. The scale model rotary kiln has been the most successful of the three projects. The kiln has been completed as planned and successfully operated with a number of feedstock materials. Good qualitative data have been obtained on conversion rate capacities, charcoal yields, and off gas combustion product temperatures. In all, about one hundred test runs were made in the scale model kiln. About 90% of the results expected were attained. The laboratory services project was designed to provide analytical testing for the other two projects and to do basic studies in biomass material conversion processes. The project delivered the testing services, but was severely restricted in the area of basic studies because of the failure of the main instrument, the gas chromatograph, to operate successfully. In all it is estimated that this project attained about 80% of its expected goals.

  11. Auto-Gopher: A Wire-Line Rotary-Hammer Ultrasonic Drill

    Science.gov (United States)

    Badescu, Mircea; Sherrit, Stewart; Bao, Xiaogi; Bar-Cohen, Yoseph; Chen, Beck

    2011-01-01

    Developing technologies that would enable NASA to sample rock, soil, and ice by coring, drilling or abrading at a significant depth is of great importance for a large number of in-situ exploration missions as well as for earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for records of past and present life on the planet, as well as, the search for water and other resources. A deep corer, called Auto-Gopher, is currently being developed as a joint effort of the JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher is a wire-line rotary-hammer drill that combines rock breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) that has been developed as an adaptable tool for many of drilling and coring applications. The USDC uses an intermediate free-flying mass to transform the high frequency vibrations of the horn tip into a sonic hammering of a drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher. The lessons learned from testing the ice gopher were implemented into the design of the Auto-Gopher by inducing a rotary motion onto the fluted coring bit. A wire-line version of such a system would allow penetration of significant depth without a large increase in mass. A laboratory version of the corer was developed in the NDEAA lab to determine the design and drive parameters of the integrated system. The design configuration lab version of the design and fabrication and preliminary testing results are presented in this paper

  12. Does the Reciproc file remove root canal bacteria and endotoxins as effectively as multifile rotary systems?

    Science.gov (United States)

    Marinho, A C S; Martinho, F C; Gonçalves, L M; Rabang, H R C; Gomes, B P F A

    2015-06-01

    To evaluate the effectiveness of Reciproc for the removal of cultivable bacteria and endotoxins from root canals in comparison with multifile rotary systems. The root canals of forty human single-rooted mandibular pre-molars were contaminated with an Escherichia coli suspension for 21 days and randomly assigned to four groups according to the instrumentation system: GI - Reciproc (VDW); GII - Mtwo (VDW); GIII - ProTaper Universal (Dentsply Maillefer); and GIV -FKG Race(™) (FKG Dentaire) (n = 10 per group). Bacterial and endotoxin samples were taken with a sterile/apyrogenic paper point before (s1) and after instrumentation (s2). Culture techniques determined the colony-forming units (CFU) and the Limulus Amebocyte Lysate assay was used for endotoxin quantification. Results were submitted to paired t-test and anova. At s1, bacteria and endotoxins were recovered in 100% of the root canals investigated (40/40). After instrumentation, all systems were associated with a highly significant reduction of the bacterial load and endotoxin levels, respectively: GI - Reciproc (99.34% and 91.69%); GII - Mtwo (99.86% and 83.11%); GIII - ProTaper (99.93% and 78.56%) and GIV - FKG Race(™) (99.99% and 82.52%) (P endotoxin removal (P > 0.01). The reciprocating single file, Reciproc, was as effective as the multifile rotary systems for the removal of bacteria and endotoxins from root canals. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  13. Torsion and bending properties of shape memory and superelastic nickel-titanium rotary instruments.

    Science.gov (United States)

    Ninan, Elizabeth; Berzins, David W

    2013-01-01

    Recently introduced into the market are shape memory nickel-titanium (NiTi) rotary files. The objective of this study was to investigate the torsion and bending properties of shape memory files (CM Wire, HyFlex CM, and Phoenix Flex) and compare them with conventional (ProFile ISO and K3) and M-Wire (GT Series X and ProFile Vortex) NiTi files. Sizes 20, 30, and 40 (n = 12/size/taper) of 0.02 taper CM Wire, Phoenix Flex, K3, and ProFile ISO and 0.04 taper HyFlex CM, ProFile ISO, GT Series X, and Vortex were tested in torsion and bending per ISO 3630-1 guidelines by using a torsiometer. All data were statistically analyzed by analysis of variance and the Tukey-Kramer test (P = .05) to determine any significant differences between the files. Significant interactions were present among factors of size and file. Variability in maximum torque values was noted among the shape memory files brands, sometimes exhibiting the greatest or least torque depending on brand, size, and taper. In general, the shape memory files showed a high angle of rotation before fracture but were not statistically different from some of the other files. However, the shape memory files were more flexible, as evidenced by significantly lower bending moments (P < .008). Shape memory files show greater flexibility compared with several other NiTi rotary file brands. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Evaluation of apical transportation and centring ability of five thermally treated NiTi rotary systems.

    Science.gov (United States)

    Pinheiro, S R; Alcalde, M P; Vivacqua-Gomes, N; Bramante, C M; Vivan, R R; Duarte, M A H; Vasconcelos, B C

    2017-11-27

    To evaluate apical transportation and centring ability during root canal preparation in mesial root canals of mandibular molars associated with ProTaper Gold (PTG), ProDesign S (PDS), Hyflex CM (HCM), Hyflex EDM and ProDesign Logic (PDL). Sixty mandibular first molars with two separate canals in the mesial root were selected after root anatomy pairing by microcomputed tomography (microCT). The teeth were randomly divided into five groups (n = 24); the root canal volume was calculated to ensure sample homogeneity. All the root canals were prepared up to size 25 in accordance with the instructions of each rotary system manufacturer. After root canal preparation, the teeth were scanned by microCT to analyse apical transportation, root canal centralization and the pre- and post-preparation root canal volume at the apical and cervical levels. Kruskal-Wallis and Dunn tests were used for comparisons amongst groups for transportation values. For volume changes, the parametric ANOVA and Tukey's tests were used RESULTS: There were no significant differences in apical transportation amongst the rotary systems (P > 0.05). All the systems created apical transportation; values ranging from 0.031 mm (PDL) to 0.072 mm (PTG), and enlargements between 39% (HCM) and 91.1% (PDS) were observed. In relative to cervical transportation, significant differences were observed amongst the systems (P Hyflex CM and Prodesign Logic systems were associated with more centred preparations. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  15. Impact of heat treatments on the fatigue resistance of different rotary nickel-titanium instruments.

    Science.gov (United States)

    Braga, Lígia Carolina Moreira; Faria Silva, Ana Cristina; Buono, Vicente Tadeu Lopes; de Azevedo Bahia, Maria Guiomar

    2014-09-01

    The aim of this study was to assess the influence of M-Wire (Dentsply Tulsa Dental Specialties, Tulsa, OK) and controlled memory technologies on the fatigue resistance of rotary nickel-titanium (NiTi) files by comparing files made using these 2 technologies with conventional NiTi files. Files with a similar cross-sectional design and diameter were chosen for the study: new 30/.06 files of the EndoWave (EW; J. Morita Corp, Osaka, Japan), HyFlex (HF; Coltene/Whaledent, Inc, Cuyahoga Falls, OH), ProFile Vortex (PV; Dentsply Tulsa Dental Specialties, Tulsa, OK), and Typhoon (TYP; Clinician's Choice Dental Products, New Milford, CT) systems together with ProTaper Universal F2 instruments (PTU F2; Dentsply Maillefer, Ballaigues, Switzerland). The compositions and transformation temperatures of the instruments were analyzed using x-ray energy-dispersive spectroscopy and differential scanning calorimetry, whereas the mean file diameter values at 3 mm from the tip (D3) were measured using image analysis software. The average number of cycles to failure was determined using a fatigue test device. X-ray energy-dispersive spectroscopy analysis showed that, on average, all the instruments exhibited the same chemical composition, namely, 51% Ni-49% Ti. The PV, TYP, and HF files exhibited increased transformation temperatures. The PTU F2, PV, and TYP files had similar D3 values, which were less than those of the EW and HF files. The average number of cycles to failure values were 150% higher for the TYP files compared with the PV files and 390% higher for the HF files compared with the EW files. M-Wire and controlled memory technologies increase the fatigue resistance of rotary NiTi files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Grating exchange system of independent mirror supported by floating rotary stage

    Science.gov (United States)

    Zhang, Jianhuan; Tao, Jin; Liu, Yan; Nan, Yan

    2015-10-01

    The performance of The Grating Exchange System can satisfy the Thirty Meter Telescope - TMT for astronomical observation WFOS index requirements and satisfy the requirement of accuracy in the grating exchange. It is used to install in the MOBIE and a key device of MOBIE. The Wide Field Optical Spectrograph (WFOS) is one of the three first-light observing capabilities selected by the TMT Science Advisory Committee. The Multi-Object Broadband Imaging Echellette (MOBIE) instrument design concept has been developed to address the WFOS requirements as described in the TMT Science-Based Requirements Document (SRD). The Grating Exchange System uses a new type of separate movement way of three grating devices and a mirror device. Three grating devices with a mirror are able to achieve independence movement. This kind of grating exchange system can effectively solve the problem that the volume of the grating change system is too large and that the installed space of MOBIE instruments is too limit. This system adopts the good stability, high precision of rotary stage - a kind of using air bearing (Air bearing is famous for its ultra-high precision, and can meet the optical accuracy requirement) and rotation positioning feedback gauge turntable to support grating device. And with a kind of device which can carry greater weight bracket fixed on the MOBIE instrument, with two sets of servo motor control rotary stage and the mirror device respectively. And we use the control program to realize the need of exercising of the grating device and the mirror device. Using the stress strain analysis software--SolidWorks for stress and strain analysis of this structure. And then checking the structure of the rationality and feasibility. And prove that this system can realize the positioning precision under different working conditions can meet the requirements of imaging optical grating diffraction efficiency and error by the calculation and optical performance analysis.

  17. Geometric analysis of root canals prepared by four rotary NiTi shaping systems.

    Science.gov (United States)

    Hashem, Ahmed Abdel Rahman; Ghoneim, Angie Galal; Lutfy, Reem Ahmed; Foda, Manar Yehia; Omar, Gihan Abdel Fatah

    2012-07-01

    A great number of nickel-titanium (NiTi) rotary systems with noncutting tips, different cross-sections, superior resistance to torsional fracture, varying tapers, and manufacturing method have been introduced to the market. The purpose of this study was to evaluate and compare the effect of 4 rotary NiTi preparation systems, Revo-S (RS; Micro-Mega, Besancon Cedex, France), Twisted file (TF; SybronEndo, Amersfoort, The Netherlands), ProFile GT Series X (GTX; Dentsply, Tulsa Dental Specialties, Tulsa, OK), and ProTaper (PT; Dentsply Maillefer, Ballaigues, Switzerland), on volumetric changes and transportation of curved root canals. Forty mesiobuccal canals of mandibular molars with an angle of curvature ranging from 25° to 40° were divided according to the instrument used in canal preparation into 4 groups of 10 samples each: group RS, group TF, group GTX, and group PT. Canals were scanned using an i-CAT CBCT scanner (Imaging Science International, Hatfield, PA) before and after preparation to evaluate the volumetric changes. Root canal transportation and centering ratio were evaluated at 1.3, 2.6, 5.2, and 7.8 mm from the apex. The significance level was set at P ≤ .05. The PT system removed a significantly higher amount of dentin than the other systems (P = .025). At the 1.3-mm level, there was no significant difference in canal transportation and centering ratio among the groups. However, at the other levels, TF maintained the original canal curvature recording significantly the least degree of canal transportation as well as the highest mean centering ratio. The TF system showed superior shaping ability in curved canals. Revo-S and GTX were better than ProTaper regarding both canal transportation and centering ability. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Morphometric analysis of shank-to-flute ratio in rotary nickel-titanium files.

    Science.gov (United States)

    Biz, M T; Figueiredo, J A P

    2004-06-01

    To evaluate the shank-to-flute ratio in rotary nickel-titanium (Ni-Ti) instruments. The cutting portion of 15 size 30 Ni-Ti rotary instruments, ProFile.04, ProFile.06, Pow R.02, Pow R.04 and Quantec series 2000, were examined. The handles of the instruments were fixed to a bench and supported by a removable resin base. The cutting portion was then manually abraded with abrasive strips along one aspect of their length. All instruments were fixed in a stub that permitted the adaptation and inspection of six instruments at the same time. A scanning electron microscope (SEM; Phillips model XL 20; Eindhmoven, the Netherlands) at x60 magnification was used to collect cross-sectional measurements of the shank and the flutes at the first, third and fifth flutes from the tip. The software autocad 2000 was used to measure these areas. The shank percentage value was, on average, equal to or greater than the flute percentage value at the sites analyzed. A regular and proportional pattern of increase of shank and flute measurements, as well as the ratio between them, was preserved. There was no significant difference between instruments and between flute sites on the same instrument (P > 0.05). However, the Quantec instruments had a flute area twice the flute area of the other instruments. The instruments had a shank percentage measurement value equal to or greater than the flute percentage value; the cross-sectional shank-to-flute ratio was preserved. The instruments had similar shank areas, but the flute area of the Quantec instruments was twice their shank area; i.e. the design of the Quantec files provides longitudinal reinforcement by means of a gain in flute area.

  19. In vitro investigation of the cleaning efficacy, shaping ability, preparation time and file deformation of continuous rotary, reciprocating rotary and manual instrumentations in primary molars.

    Science.gov (United States)

    Ramazani, Nahid; Mohammadi, Abbas; Amirabadi, Foroogh; Ramazani, Mohsen; Ehsani, Farzane

    2016-01-01

    Background. Efficient canal preparation is the key to successful root canal treatment. This study aimed to assess the cleaning and shaping ability, preparation time and file deformation of rotary, reciprocating and manual instrumentation in canal preparation of primary molars. Methods. The mesiobuccal canals of 64 extracted primary mandibular second molars were injected with India ink. The samples were randomly divided into one control and three experimental groups. Experimental groups were instrumented with K-file, Mtwo in continuous rotation and Reciproc in reciprocating motion, respectively. The control group received no treatment. The files were discarded after four applications. Shaping ability was evaluated using CBCT. After clearing, ink removal was scored. Preparation time and file fracture or deformation was also recorded. Data were analyzed with SPSS 19 using chi-squared, Fisher's exact test, Kruskal-Wallis and post hoc tests at a significance level of 0.05. Results. Considering cleanliness, at coronal third Reciproc was better than K-file (P < 0.001), but not more effective than Mtwo (P = 0.080). Furthermore, Mtwo leaved the canal cleaner than K-file (P = 0.001). In the middle third, only Reciproc exhibited better cleaning efficacy than K-file (P = 0.005). In the apical third, no difference was detected between the groups (P = 0.794). Regarding shaping ability, no differences were found between Reciproc and Mtwo (P = 1.00). Meanwhile, both displayed better shaping efficacy than K-file (P < 0.05). Between each two groups, there were differences in preparation time (P < 0.05), with Reciproc being the fastest. No file failure occurred. Conclusion. Fast and sufficient cleaning and shaping could be achieved with Mtwo and especially with Reciproc.

  20. In vitro investigation of the cleaning efficacy, shaping ability, preparation time and file deformation of continuous rotary, reciprocating rotary and manual instrumentations in primary molars

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2016-03-01

    Full Text Available Background. Efficient canal preparation is the key to successful root canal treatment. This study aimed to assess the cleaning and shaping ability, preparation time and file deformation of rotary, reciprocating and manual instrumentation in canal preparation of primary molars. Methods. The mesiobuccal canals of 64 extracted primary mandibular second molars were injected with India ink. The samples were randomly divided into one control and three experimental groups. Experimental groups were instrumented with K-file, Mtwo in continuous rotation and Reciproc in reciprocating motion, respectively. The control group received no treatment. The files were discarded after four applications. Shaping ability was evaluated using CBCT. After clearing, ink removal was scored. Preparation time and file fracture or deformation was also recorded. Data were analyzed with SPSS 19 using chi-squared, Fisher’s exact test, Kruskal-Wallis and post hoc tests at a significance level of 0.05. Results. Considering cleanliness, at coronal third Reciproc was better than K-file (P < 0.001, but not more effective than Mtwo (P = 0.080. Furthermore, Mtwo leaved the canal cleaner than K-file (P = 0.001. In the middle third, only Reciproc exhibited better cleaning efficacy than K-file (P = 0.005. In the apical third, no difference was detected between the groups (P = 0.794. Regarding shaping ability, no differences were found between Reciproc and Mtwo (P = 1.00. Meanwhile, both displayed better shaping efficacy than K-file (P < 0.05. Between each two groups, there were differences in preparation time (P < 0.05, with Reciproc being the fastest. No file failure occurred. Conclusion. Fast and sufficient cleaning and shaping could be achieved with Mtwo and especially with Reciproc.