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https://www.readbyqxmd.com/read/27910597/note-attenuation-motion-of-acoustically-levitated-spherical-rotor
#1
P Lü, Z Y Hong, J F Yin, N Yan, W Zhai, H P Wang
Here we observe the attenuation motion of spherical rotors levitated by near-field acoustic radiation force and analyze the factors that affect the duration time of free rotation. It is found that the rotating speed of freely rotating rotor decreases exponentially with respect to time. The time constant of exponential attenuation motion depends mainly on the levitation height, the mass of rotor, and the depth of concave ultrasound emitter. Large levitation height, large mass of rotor, and small depth of concave emitter are beneficial to increase the time constant and hence extend the duration time of free rotation...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910381/single-phase-driven-ultrasonic-motor-using-two-orthogonal-bending-modes-of-sandwiching-piezo-ceramic-plates
#2
Yuting Ma, Minkyu Choi, Kenji Uchino
A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27908049/fast-computation-of-time-dependent-acoustic-fields
#3
Michael Carley, Ghader Ghorbaniasl
A method for the fast evaluation of time-dependent acoustic fields from complex sources is presented. The technique is based on a fast integration method for the boundary integral arising in a Kirchhoff formulation and requires a small, and roughly constant, computation time to compute a transient signal, at the expense of a pre-processing stage. In the calculations in this paper, based on test cases for a single rotor, a counter-rotating open rotor, and a broadband volume source, it is found that transient field calculations require an order of magnitude less computational time for the field from an array of 16 384 sources, a computational advantage that increases with source number...
November 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27907997/control-of-oscillations-in-vibration-machines-start-up-and-passage-through-resonance
#4
A Fradkov, D Gorlatov, O Tomchina, D Tomchin
Control of oscillations in mechanical systems in the start-up and passage through resonance modes is studied. In both cases, the control algorithm is based on the speed-gradient method with energy-based goal functions. It is shown that for Hamiltonian 1-degree of freedom (DOF) systems, it is generically possible to move the system from any initial state to any final state by means of a controlling force of arbitrarily small intensity. Controlled passage through resonance is studied for a 5-DOF vibration machine taking friction into account...
November 2016: Chaos
https://www.readbyqxmd.com/read/27907144/a-new-efficient-method-for-detecting-phase-singularity-in-cardiac-fibrillation
#5
Young-Seon Lee, Jun-Seop Song, Minki Hwang, Byounghyun Lim, Boyoung Joung, Hui-Nam Pak
BACKGROUND: The point of phase singularity (PS) is considered to represent a spiral wave core or a rotor in cardiac fibrillation. Computational efficiency is important for detection of PS in clinical electrophysiology. We developed a novel algorithm for highly efficient and robust detection of PS. METHODS: In contrast to the conventional method, which calculates PS based on the line integral of the phase around a PS point equal to ±2π (the Iyer-Gray method), the proposed algorithm (the location-centric method) looks for the phase discontinuity point at which PS actually occurs...
2016: PloS One
https://www.readbyqxmd.com/read/27906655/methodology-considerations-in-phase-mapping-of-human-cardiac-arrhythmias
#6
Ramya Vijayakumar, Sunil K Vasireddi, Phillip S Cuculich, Mitchell N Faddis, Yoram Rudy
BACKGROUND: Phase analysis of cardiac arrhythmias, particularly atrial fibrillation, has gained interest because of the ability to detect organized stable drivers (rotors) and target them for therapy. However, the lack of methodology details in publications on the topic has resulted in ongoing debate over the phase mapping technique. By comparing phase maps and activation maps, we examined advantages and limitations of phase mapping. METHODS AND RESULTS: Seven subjects were enrolled...
November 2016: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/27901153/structure-activity-relationship-for-the-solid-state-emission-of-a-new-family-of-push-pull-%C3%AF-extended-chromophores
#7
Andrea Nitti, Francesca Villafiorita-Monteleone, Aurora Pacini, Chiara Botta, Tersilla Virgili, Alessandra Forni, Elena Cariati, Massimo Boiocchi, Dario Pasini
We report the design, synthesis, molecular optical properties, and solid state emissive behaviour of a series of novel compounds, which, similar to the archetypal AIE luminogen tetraphenylethene, are formed of a central olefin stator and decorated with either three or four rotors. These rotors, being either electron-rich substituted benzenes, or electron-withdrawing functional groups (esters, ketones, cyano groups) confer a "push-pull" character to the overall molecular structure. Building on both new and already published contributions, a comprehensive picture of the properties and the potential of these compounds is provided...
November 30, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27901146/comparative-experimental-and-theoretical-study-of-the-rotational-excitation-of-co-by-collision-with-ortho-and-para-d2-molecules
#8
T Stoecklin, A Faure, P Jankowski, S Chefdeville, A Bergeat, C Naulin, S B Morales, M Costes
A joint crossed beam and quantum mechanical investigation of the rotationally inelastic collisions of CO with ortho- and para-D2 molecules is reported. A new 4D potential energy surface (PES) averaged over the ground vibrational states of D2 and CO is used to calculate the rovibrational bound states of the ortho-D2-CO complexes. Close coupling calculations are then performed in the rigid rotor approximation for ortho- and para-D2 colliding with CO for the experimentally investigated transition of CO (j = 0 → 1) and for collision energies ranging from 0...
November 30, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27896356/vapochromic-features-of-new-luminogens-based-on-julolidine-containing-styrene-copolymers
#9
Giuseppe Iasilli, Fabio Martini, Pierpaolo Minei, Giacomo Ruggeri, Andrea Pucci
We report on vapochromic films suitable for detecting volatile organic compounds (VOCs), based on new polystyrene copolymers containing julolidine fluorescent molecular rotors (JCAEM). Poly(styrene-co-hydroxyethylmethacrylate) copolymers functionalized with cyanovinyl-julolidine moieties of different compositions were prepared, (P(STY-co-JCAEM)(m) with m = 0.06-0.61). The sensing performance of the spin-coated copolymer films demonstrated significant vapochromism when exposed to VOCs characterized by high vapour pressure and a favourable interaction with the polymer matrix, such as Et2O and CH2Cl2...
November 29, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27890740/rotor-mapping-and-ablation-spinning-out-of-control
#10
EDITORIAL
Lucas V A Boersma
No abstract text is available yet for this article.
November 23, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/27886051/a-laminar-flow-based-microfluidic-tesla-pump-via-lithography-enabled-3d-printing
#11
Mohammed-Baker Habhab, Tania Ismail, Joe Fujiou Lo
Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions...
November 23, 2016: Sensors
https://www.readbyqxmd.com/read/27882557/laboratory-scale-milling-of-whole-durum-flour-quality-effect-of-mill-configuration-and-seed-conditioning
#12
Lingzhu Deng, Frank A Manthey
BACKGROUND: Research was conducted to develop a laboratory milling procedure to make whole-durum flour. An ultra-centrifugal mill was evaluated by determining the effect of mill configuration and seed conditioning on particle size distribution and quality of whole-wheat flour. RESULTS: Particle size of whole-wheat flour decreased as screen aperture decreased from 1,000 to 250 µm; as rotor speed increased from 6,000 to 18,000 rpm; and as seed conditioning moisture content decreased from 150 to 90 g kg(-1) ...
November 23, 2016: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/27870970/panoramic-characterization-of-endocardial-left-atrial-activation-during-human-persistent-af-insights-from-non-contact-mapping
#13
Geoffrey Lee, Alex J A McLellan, Ross J Hunter, Matthew J Lovell, Malcolm Finlay, Waqas Ullah, Mehul B Dhinoja, Simon Sporton, Mark J Earley, Richard J Schilling
BACKGROUND: The relative importance of focal drivers, multiple wavelets, rotors and endocardial-epicardial circuits in the maintenance of persistent AF remains unclear. Our objective was to characterize AF wavefront (WF) dynamics during persistent AF. METHODS: The Ensite 3000 (St Jude Medical) non-contact mapping system was used to map the LA of 15 patients with persistent AF. Wavefronts were classified into planar WFs, rotors or focal WFs. For each new WF the site of origin, the unipolar electrogram, and propagation patterns were determined...
November 9, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27865110/specifically-and-wash-free-labeling-of-snap-tag-fused-proteins-with-a-hybrid-sensor-to-monitor-local-micro-viscosity
#14
Chao Wang, Xinbo Song, Lingcheng Chen, Yi Xiao
Viscosity, as one of the major factors of intracellular microenvironment, influences the function of proteins. To detect local micro-viscosity of a protein, it is a precondition to apply a viscosity sensor for specifically target to proteins. However, all the reported small-molecule probes are just suitable for sensing/imaging of macro-viscosity in biological fluids of entire cells or organelles. To this end, we developed a hybrid sensor BDP-V BG by connecting a viscosity-sensitive boron-dipyrromethene (BODIPY) molecular rotor (BDP-V) to O(6)-benzylguanine (BG) for specific detection of local micro-viscosity of SNAP-tag fused proteins...
November 10, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27862796/proton-gated-photoisomerization-of-amino-substituted-dibenzofulvene-rotors
#15
Udaya Jayasundara, HyunJong Kim, Krishna Sahteli, Joseph I Cline, Thomas W Bell
Derivatives of 9-(2,2,2-triphenylethylidene)-fluorene (TEF) undergo E/Z photoisomerization and are candidates for light-powered molecular actuators and switches. The 2-substituted derivatives bearing an amino group (ATEF) or a dimethylamino group (DTEF) are weakly photoactive in the absence of acids, but protonation increases photoisomerization quantum yields by factors of 30-60. Such compounds may be useful for incorporation into pH-switchable photoactive devices.
November 14, 2016: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/27832001/scaling-the-low-shear-pulsatile-torvad-for-pediatric-heart-failure
#16
Jeffrey R Gohean, Erik R Larson, Brian H Hsi, Mark Kurusz, Richard W Smalling, Raul G Longoria
This article provides an overview of the design challenges associated with scaling the low-shear pulsatile TORVAD ventricular assist device (VAD) for treating pediatric heart failure. A cardiovascular system model was used to determine that a 15 ml stroke volume device with a maximum flow rate of 4 L/min can provide full support to pediatric patients with body surface areas between 0.6 to 1.5 m2. Low shear stress in the blood is preserved as the device is scaled down and remains at least two orders of magnitude less than continuous flow VADs...
November 9, 2016: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/27828272/ir-radiation-characteristics-and-operating-range-research-for-a-quad-rotor-unmanned-aircraft-vehicle
#17
Mali Gong, Rui Guo, Sifeng He, Wei Wang
The security threats caused by multi-rotor unmanned aircraft vehicles (UAVs) are serious, especially in public places. To detect and control multi-rotor UAVs, knowledge of IR characteristics is necessary. The IR characteristics of a typical commercial quad-rotor UAV are investigated in this paper through thermal imaging with an IR camera. Combining the 3D geometry and IR images of the UAV, a 3D IR characteristics model is established so that the radiant power from different views can be obtained. An estimation of operating range to detect the UAV is calculated theoretically using signal-to-noise ratio as the criterion...
November 1, 2016: Applied Optics
https://www.readbyqxmd.com/read/27827349/a-nanoengine-governor-based-on-the-end-interfacial-effect
#18
Jiao Shi, Kun Cai, Qing-Hua Qin
A conceptual design is presented for a nanoengine governor based on the end interfacial effect of two rotary nanotubes. The governor contains a thermal-driven rotary nanomotor made from double-walled carbon nanotubes (DWCNTs) and a coaxially laid out rotary nanotube near one end of the nanomotor rotor. The rotation of the rotor in the nanomotor can be controlled by two features. One is the stator (the outer tube of DWCNTs) which has some end atoms with inward radial deviation (IRD) on the stator. The other is the relative rotation of the neighboring rotary tube of the rotor...
November 9, 2016: Nanotechnology
https://www.readbyqxmd.com/read/27826248/slow-conduction-in-the-border-zones-of-patchy-fibrosis-stabilizes-the-drivers-for-atrial-fibrillation-insights-from-multi-scale-human-atrial-modeling
#19
Ross Morgan, Michael A Colman, Henry Chubb, Gunnar Seemann, Oleg V Aslanidi
Introduction: The genesis of atrial fibrillation (AF) and success of AF ablation therapy have been strongly linked with atrial fibrosis. Increasing evidence suggests that patient-specific distributions of fibrosis may determine the locations of electrical drivers (rotors) sustaining AF, but the underlying mechanisms are incompletely understood. This study aims to elucidate a missing mechanistic link between patient-specific fibrosis distributions and AF drivers. Methods: 3D atrial models integrated human atrial geometry, rule-based fiber orientation, region-specific electrophysiology, and AF-induced ionic remodeling...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27826130/focal-impulse-and-rotor-modulation-acute-procedural-observations-and-extended-clinical-follow-up
#20
Jonathan S Steinberg, Yash Shah, Advay Bhatt, Tina Sichrovsky, Aysha Arshad, Emily Hansinger, Dan Musat
BACKGROUND: Focal impulse and rotor modulation (FIRM) was based on the premise that atrial fibrillation (AF) is sustained by rotors which are sufficiently stable to be eliminated by targeted ablation. Early experience reported high success as compared to conventional strategies. OBJECTIVE: To report on a single-center experience with extended follow-up using FIRM in a variety of AF pts. METHODS: All FIRM-guided ablation procedures were included...
November 5, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
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