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Journal articles on the topic 'Mean electrical Axis'
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Kuhn, Lisa, and Louise Rose. "ECG Interpretation Part 1: Understanding Mean Electrical Axis." Journal of Emergency Nursing 34, no. 6 (December 2008): 530–34. http://dx.doi.org/10.1016/j.jen.2008.01.007.
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BROJBĂ, Cristian. "Determination of the Mean Electrical Axis in Dogs and Cats (Mini-Review)." Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Veterinary Medicine 75, no. 1 (May 19, 2018): 137. http://dx.doi.org/10.15835/buasvmcn-vm:004717.
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In this study we set out to reveal the practical importance of the determination of the mean electrical axis (MEA) in dogs and cats. The Hexaxial Reference System is used for the determination of the cardiac electrical axis. We described 2 methods, that are used the most frequently and we confirmed that the movement of the mean electrical axis is useful in the diagnosis of cardiac diseases.
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Anderson, J., and S. E. DiCarlo. ""Virtual" experiment for understanding the electrocardiogram and the mean electrical axis." Advances in Physiology Education 23, no. 1 (June 2000): S1–17. http://dx.doi.org/10.1152/advances.2000.23.1.s1.
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Educators have placed an emphasis on the development of laboratory materials that supplement the traditional lecture format. The laboratory materials should encourage active learning, small group discussion, and problem-solving skills. To this end, we developed a virtual experiment designed to introduce students to the theory and application of the electrocardiogram (ECG) and the mean electrical axis (MEA). After reviewing background material, the students will analyze ECG recordings from two individuals who underwent a series of experimental procedures. The students are challenged to reduce and analyze the data, calculate and plot the MEA, and answer questions related to the theory and application of the ECG. In conducting the virtual experiment, students are introduced to inquiry-based learning through experimentation.
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CARNABUCI, Cristina, Rosalba TOGNETTI, Tommaso VEZZOSI, Federica MARCHESOTTI, Valentina PATATA, and Oriol DOMENECH. "Left shift of the ventricular mean electrical axis in healthy Doberman Pinschers." Journal of Veterinary Medical Science 81, no. 4 (2019): 620–25. http://dx.doi.org/10.1292/jvms.18-0699.
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da Costa, Cássia Fré, Nelson Samesima, and Carlos Alberto Pastore. "Cardiac Mean Electrical Axis in Thoroughbreds—Standardization by the Dubois Lead Positioning System." PLOS ONE 12, no. 1 (January 17, 2017): e0169619. http://dx.doi.org/10.1371/journal.pone.0169619.
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Cooper, R., J. J. McGrath, S. Dooley, and M. T. Kopetzky. "Chronic exposure to carbon monoxide at high altitude: Effects on mean electrical axis." Physiology & Behavior 46, no. 1 (July 1989): 75–79. http://dx.doi.org/10.1016/0031-9384(89)90325-9.
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Brestenský, J., S. Ševčík, and L. Rosenberg. "Mean Electromotive Force Due to Magnetoconvection in Rotating Horizontal Layer in Dependence on Boundary Conditions." Symposium - International Astronomical Union 157 (1993): 457–61. http://dx.doi.org/10.1017/s0074180900174625.
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The instability due to a vertical uniform temperature gradient is studied in a rapidly rotating horizontal layer of an electrically conducting fluid permeated by an azimuthal magnetic field linearly growing with the distance from the vertical axis of rotation. In addition to the boundary conditions used in So ward's study (1979), that is, force-free surface and perfect electrical and thermal conductivity outside, also other conditions more realistic for the Earth's core are considered, that is, rigid surface and electrically insulating walls. Using the concept of meanfield mlid mean electromotive and ponderomotive forces (E.M.F. and P.M.F.) are calculated and compared for various boundary conditions. The dependence of the E.M.F. and P.M.F. on the electromagnetic boundary conditions is strong (slight) if the boundaries are free (rigid).
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Sousa, Marlos G., Mariana C. H. Rondelli, Sheila S. S. Nogueira, and Roberta Carareto. "Influence of body position on the measurement of electrocardiographic waves in healthy dogs." Pesquisa Veterinária Brasileira 38, no. 2 (February 2018): 340–44. http://dx.doi.org/10.1590/1678-5150-pvb-5071.
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ABSTRACT: The agreement between the electrocardiographic waves measured from tracings recorded in right lateral recumbency and several other unusual body positions was assessed. Electrocardiograms were recorded in 160 healthy dogs in right lateral, left lateral, dorsal and sternal recumbencies, as well as in standing position. Considering the right lateral recordings as the gold standard, the lowest biases for the majority of ECG parameters were calculated from left lateral recordings, whereas the highest biases were documented from dorsal and standing positions. For the mean electrical axis, the dorsal recumbency produced the lowest bias, while the greatest one was identified in sternal position. An analysis of variance indicated differences when the means of P wave duration and amplitude, duration of QRS and QT, and mean electrical axis obtained in unusual positions were compared with right lateral. In conclusion, left lateral recumbency produced the most similar measurements as compared to right lateral, but the wide limits of agreement preclude the use and interpretation of these positions interchangeably.
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Fathi, M. B., and S. A. Jafari. "Dynamical mean field theory equations on nearly real frequency axis." Physica B: Condensed Matter 405, no. 6 (March 2010): 1658–61. http://dx.doi.org/10.1016/j.physb.2009.12.063.
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Sanyal, Sagar, Pradip Kumar Das, Probal Ranjan Ghosh, Kinsuk Das, Kezha V. Vupru, Chandan Rajkhowa, and Mohan Mondal. "Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains." Veterinary Medicine International 2010 (2010): 1–8. http://dx.doi.org/10.4061/2010/790310.
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A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains ( each). It was found that the respiration and heart rates were higher () in Manipur than other three strains. Amplitude () and duration of P wave and QRS complex differed () among the strains. Mizoram strain had the highest amplitude and duration of P wave and QRS complex. On the other hand, higher () amplitude and duration of T wave were recorded in Arunachalee and Mizoram strains. The mean electrical axis of QRS complex that were recorded for Arunachalee and Manipur strains were similar to that reported for other bovine species; whereas the electrical axis of QRS for Nagamese and Mizoram strains were more close to feline and caprine species, respectively. In conclusion, electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species.
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Lewis, Martyn, Jonathan Bouvard, Kevin Eatwell, and Geoff Culshaw. "Standardisation of electrocardiographic examination in corn snakes (Pantherophis guttatus)." Veterinary Record 186, no. 19 (March 22, 2020): e29-e29. http://dx.doi.org/10.1136/vr.105713.
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IntroductionCorn snakes are a very common pet reptile species, yet there is an absence of evidence-based literature standardising collection of ECG or detailing ECG deflection morphology in the normal animal. The authors describe a well-tolerated, reproducible technique and detail the cardiac cycle in terms of lead 2 equivalent waveforms and intervals.Animals29 adult corn snakes.Materials and methodsThis prospective study evaluated, under species-appropriate, standardised conditions, a technique for producing standard six-lead ECG tracings. Lead 2 equivalent cardiac cycles were described in detail and statistically analysed for sex, weight, length, heart rate and mean electrical axis.ResultsHigh-quality tracings demonstrated common ECG characteristics for this species, including no Q, S or SV waves, prolonged PR and RT intervals, rhythmic oscillation of the baseline, short TP segments, and a right displaced mean electrical axis. An influence of sex, weight or length on heart rate and mean electrical axis was not identified.ConclusionsTo the authors’ knowledge, this is the first study to describe a standardised technique for recording ECG in significant numbers of normal corn snakes. Ranges have been provided that may be of diagnostic value or form the basis for future development of reference intervals for this species.
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Giannazzo, Filippo, Corrado Bongiorno, Salvatore di Franco, Emanuele Rimini, and Vito Raineri. "Micro- and Nano-Scale Electrical Characterization of Epitaxial Graphene on Off-Axis 4H-SiC (0001)." Materials Science Forum 717-720 (May 2012): 637–40. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.637.
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The electrical properties of epitaxial graphene (EG) grown on 8° off-axis 4H-SiC (0001) by annealing at 1600 °C in inert gas ambient (Ar) were studied. The sheet resistance of the EG layers (Rsh=740±50Ω/sq) and the specific contact resistance of Ni contacts to EG (ρc≈6x10-5Ωcm2) were evaluated on micrometer scale by measurements on transmission line model (TLM) structures. Si3N4was evaluated as a gate dielectric, showing excellent coverage to EG and a limited effect on its conductivity. The high n-type doping (~1013cm-2) of EG, as well as the field effect mobility (μ) dependence on n were determined using top gated field effect transistors (FETs) with Si3N4gate dielectric. Electron mean free path (lloc) and mobility (μloc) were also locally determined, on submicrometer scale, by scanning probe microscopy, showing a broad distribution of μlocvalues, with the most probable value very similar to macroscopic carrier mobility μ.
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Bisogni, Livio, Ramtin Mollaiyan, Matteo Pettinari, Paolo Neri, and Marco Gabiccini. "Automatic Calibration of a Two-Axis Rotary Table for 3D Scanning Purposes." Sensors 20, no. 24 (December 11, 2020): 7107. http://dx.doi.org/10.3390/s20247107.
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Rotary tables are often used to speed up the acquisition time during the 3D scanning of complex geometries. In order to avoid manual registration of the point clouds acquired with different orientations, automatic algorithms to compensate the rotation were developed. Alternatively, a proper calibration of the rotary axis with respect to the camera system is needed. Several methods are available in the literature, but they only consider a single-axis calibration. In this paper, a method for the simultaneous calibration of both axes of the table is proposed. A checkerboard is attached to the table, and several images with different poses are acquired. An optimization algorithm is then setup to determine the orientation and the locations of the two axes. A metric to assess the calibration quality was also defined by computing the average mean reprojection error. This metric is used to investigate the optimal number and distribution of the calibration poses, demonstrating that the optimum calibration results are achieved when a wider dispersion of the calibration poses is adopted.
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Kaga, Hisashi, Yoshiaki Kinemuchi, Koji Watari, Satoshi Tanaka, Atsushi Makiya, Zenji Kato, and Keizo Uematsu. "Fabrication of c-axis oriented higher manganese silicide by a high-magnetic-field and its thermoelectric properties." Journal of Materials Research 22, no. 10 (October 2007): 2917–23. http://dx.doi.org/10.1557/jmr.2007.0360.
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We report the preparation and thermoelectric properties of oriented higher manganese silicide (HMS) with a composition of MnSi1.73 bulk. The grain alignment and densification were achieved by rotating high magnetic field and spark plasma sintering (SPS) techniques, respectively. The easy magnetization axis of MnSi1.73 was found to be c-axis, and the applied magnetic field of 2 T was strong enough to rotate the powder with a mean grain size of 1 μm. The c-axis of grains was oriented when applying the magnetic field, and the degree of orientation was further increased after heat treatment. However, a secondary phase that was mono manganese silicide (MnSi) was observed as a result of oxidation on the surface of synthesized powder. The electrical conductivity of the c-axis oriented specimen along the ab-plane was about 40% larger than that for sample processed only by SPS, while the Seebeck coefficient of oriented and nonoriented specimens showed similar values regardless of existence of the second phase. Consequently, the power factor of the c-axis oriented specimen along the ab-plane was enhanced by about 35% compared to the nonoriented one. The proposed approach is found to be very effective not only in obtaining the oriented materials with nonductility but also in enhancing the thermoelectricity.
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Jomartov, A. A., S. U. Joldasbekov, and Yu M. Drakunov. "Dynamic synthesis of machine with slider-crank mechanism." Mechanical Sciences 6, no. 1 (April 2, 2015): 35–40. http://dx.doi.org/10.5194/ms-6-35-2015.
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Abstract. In this paper we consider the formulation and solution of the task of a dynamic synthesis machine with an asynchronous electric motor and a slider-crank mechanism. The constant parameters of the slider-crank mechanism (mass and moments of inertia and centers of gravity of links) and the parameters of the electrical motor are defined. The laws of motion of the machine and kinematic parameters of the mechanism are considered as given. We have developed the method of optimal dynamic synthesis of the machine, which consists of an asynchronous electric motor and a slider-crank mechanism. The criterion of optimization of the dynamic synthesis of a machine is the root mean square sum of the moments of driving forces, the forces of resistance and inertia forces which are reduced to the axis of rotation of the crank. The method of optimal dynamic synthesis of a machine can be used in the design of new and the improvement of known mechanisms and machines.
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Baranov, Pavel, Tamara Nesterenko, Evgenii Barbin, Aleksej Koleda, Shuji Tanaka, Takashiro Tsukamoto, Ivan Kulinich, Dmitry Zykov, and Alexander Shelupanov. "A novel multiple-axis MEMS gyroscope-accelerometer with decoupling frames." Sensor Review 39, no. 5 (September 16, 2019): 670–81. http://dx.doi.org/10.1108/sr-05-2018-0133.
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Purpose Technological capabilities of manufacturing microelectromechanical system (MEMS) gyroscopes are still insufficient if compared to manufacturing high-efficient gyroscopes and accelerometers. This creates weaknesses in their mechanical structure and restrictions in the measurement accuracy, stability and reliability of MEMS gyroscopes and accelerometers. This paper aims to develop a new architectural solutions for optimization of MEMS gyroscopes and accelerometers and propose a multi-axis MEMS inertial module combining the functions of gyroscope and accelerometer. Design/methodology/approach The finite element modeling (FEM) and the modal analysis in FEM are used for sensing, drive and control electrode capacitances of the multi-axis MEMS inertial module with the proposed new architecture. The description is given to its step-by-step process of manufacturing. Algorithms are developed to detect its angular rates and linear acceleration along three Cartesian axes. Findings Experimental results are obtained for eigenfrequencies and capacitances of sensing, drive and control electrodes for 50 manufactured prototypes of the silicon electromechanical sensor (SES). For 42 SES prototypes, a good match is observed between the calculated and simulated capacitance values of comb electrodes. Thus, the mean-square deviation is not over 20 per cent. The maximum difference between the calculated and simulated eigenfrequencies in the drive channel of 11 SES prototypes is not over 3 per cent. The same difference is detected for eigenfrequencies in the first sensing channel of 17 SES prototypes. Originality/value This study shows a way to design and optimize the structure and theoretical background for the development of the MEMS inertial module combining the functions of gyroscope and accelerometer. The obtained results will improve and expand the manufacturing technology of MEMS gyroscopes and accelerometers.
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Mohri, Satoshi, Kun-Lun He, Marc Dickstein, Yuval Mika, Juichiro Shimizu, Itzhak Shemer, Geng-Hua Yi, Jie Wang, Shlomo Ben-Haim, and Daniel Burkhoff. "Cardiac contractility modulation by electric currents applied during the refractory period." American Journal of Physiology-Heart and Circulatory Physiology 282, no. 5 (May 1, 2002): H1642—H1647. http://dx.doi.org/10.1152/ajpheart.00959.2001.
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Inotropic effects of electric currents applied during the refractory period have been reported in cardiac muscle in vitro using voltage-clamp techniques. We investigated how electric currents modulate cardiac contractility in normal canine hearts in vivo. Six dogs were instrumented to measure regional segment length, ventricular volume (sonomicrometry), and ventricular pressure. Cardiac contractility modulating (CCM) electric currents (biphasic square pulses, amplitude ±20 mA, total duration 30 ms) were delivered during the refractory period between pairs of electrodes placed on anterior and posterior walls. CCM significantly increased index of global contractility ( E es) from 5.9 ± 2.9 to 8.3 ± 4.6 mmHg/ml with anterior CCM, from 5.3 ± 1.8 to 8.9 ± 4.0 mmHg/ml with posterior CCM, and from 6.1 ± 2.6 to 11.0 ± 7.0 mmHg/ml with combined CCM ( P < 0.01, no significant change in volume axis intercept). End-systolic pressure-segment length relations showed contractility enhancement near CCM delivery sites, but not remotely. Relaxation was not influenced. CCM increased mean aortic pressure, but did not change peripheral resistance. Locally applied electrical currents enhanced global cardiac contractility via regional changes in myocardial contractility without impairing relaxation in situ.
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Tasinaffo, Paulo M., and Atair Rios Neto. "Predictive control with mean derivative based neural euler integrator dynamic model." Sba: Controle & Automação Sociedade Brasileira de Automatica 18, no. 1 (March 2007): 94–105. http://dx.doi.org/10.1590/s0103-17592007000100007.
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Neural networks can be trained to get internal working models in dynamic systems control schemes. This has usually been done designing the neural network in the form of a discrete model with delayed inputs of the NARMA type (Non-linear Auto Regressive Moving Average). In recent works the use of the neural network inside the structure of ordinary differential equations (ODE) numerical integrators has also been considered to get dynamic systems discrete models. In this paper, an extension of this latter approach, where a feed forward neural network modeling mean derivatives is used in the structure of an Euler integrator, is presented and applied in a Nonlinear Predictive Control (NPC) scheme. The use of the neural network to approximate the mean derivative function, instead of the dynamic system ODE instantaneous derivative function, allows any specified accuracy to be attained in the modeling of dynamic systems with the use of a simple Euler integrator. This makes the predictive control implementation a simpler task, since it is only necessary to deal with the linear structure of a first order integrator in the calculations of control actions. To illustrate the effectiveness of the proposed approach, results of tests in a problem of orbit transfer between Earth and Mars and in a problem of three-axis attitude control of a rigid body satellite are presented.
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Bjurstrom, Johan, Gunilla Wingqvist, and Ilia Katardjiev. "Synthesis of textured thin piezoelectric AlN films with a nonzero C-axis mean tilt for the fabrication of shear mode resonators." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 53, no. 11 (November 2006): 2095–100. http://dx.doi.org/10.1109/tuffc.2006.149.
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Ancillao, Andrea, Maxim Vochten, Erwin Aertbeliën, Wilm Decré, and Joris De Schutter. "Estimating the Instantaneous Screw Axis and the Screw Axis Invariant Descriptor of Motion by Means of Inertial Sensors: An Experimental Study with a Mechanical Hinge Joint and Comparison to the Optoelectronic System." Sensors 20, no. 1 (December 20, 2019): 49. http://dx.doi.org/10.3390/s20010049.
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The motion of a rigid body can be represented by the instantaneous screw axis (ISA, also known as the helical axis). Recently, an invariant representation of motion based on the ISA, namely, the screw axis invariant descriptor (SAID), was proposed in the literature. The SAID consists of six scalar features that are independent from the coordinate system chosen to represent the motion. This method proved its usefulness in robotics; however, a high sensitivity to noise was observed. This paper aims to explore the performance of inertial sensors for the estimation of the ISA and the SAID for a simple experimental setup based on a hinge joint. The free swing motion of the mechanical hinge was concurrently recorded by a marker-based optoelectronic system (OS) and two magnetic inertial measurement units (MIMUs). The ISA estimated by the MIMU was more precise, while the OS was more accurate. The mean angular error was ≈2.2° for the OS and was ≈4.4° for the MIMU, while the mean standard deviation was ≈2.3° for the OS and was ≈0.2° for the MIMU. The SAID features based on angular velocity were better estimated by the MIMU, while the features based on translational velocity were better estimated by the OS. Therefore, a combination of both measurements systems is recommended to accurately estimate the complete SAID.
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Garcia Rodriguez, Luis Fernando, Julian Ernesto Jaramillo, and Jorge Luis Chacon Velasco. "Chicamocha canyon wind energy potential and VAWT airfoil selection through CFD modeling." Revista Facultad de Ingeniería Universidad de Antioquia, no. 94 (October 17, 2019): 56–66. http://dx.doi.org/10.17533/10.17533/udea.redin.20190512.
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The use of vertical axis wind turbines (VAWT) in Colombia could tackle the energy distribution difficulties as large parts of the territory are not connected to the electrical grid. The present research experimentally determines the wind resource available of a rural place known as Chicamocha’s canyon and selects the airfoil for a VAWT blade through CFD modeling. By using the mean wind speed of the location, the performance of the NACA0018 and DU06W200 airfoils is evaluated in terms of the lift and drag coefficients through a 2D CFD modeling using OpenFOAM and the “Spalart-Allmaras fv3” turbulence model. It is found feasible the use of wind energy at the location where the mean year density power is 485 [W/m2], and the DU06W200 airfoil is suggested for constructing the blades of a VAWT, as its aerodynamic efficiency (cl/cd) overcomes by 14% the commonly used NACA0018.
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Liang, Zhuoyue, Xin Guo, Bo Yang, and Ting Zhang. "Design and Characterization of a Novel Biaxial Bionic Hair Flow Sensor Based on Resonant Sensing." Sensors 20, no. 16 (August 11, 2020): 4483. http://dx.doi.org/10.3390/s20164483.
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This paper presents the design, theoretical analysis, simulation verification, fabrication and prototype characterization of a novel biaxial bionic hair flow sensor based on resonant sensing. Firstly, the device architecture, mainly consists of a polymer hair post, a silicon micro signal transducer and a glass substrate, is described, the theoretical simplified model is established and the mechanical sensitivity to air flow is deducted. Then, the structure simulations based on Ansys software are implemented to preliminarily verify the feasibility of the proposed sensor conception and optimize the structure parameters simultaneously. Subsequently, a closed-loop control scheme based on digital phase-locked loop and an amplitude demodulation algorithm of oscillatory flow velocity based on the least mean square method are proposed to transform and extract the air flow signal, and then verify it by circuit simulations based on SIMULINK. Finally, the fabricated prototype is illustrated and comprehensively tested. The tested prototype possesses an x-axis scale factor of 1.56 Hz/(m/s)2 and a y-axis scale factor of 1.81 Hz/(m/s)2 for the steady air flow and an x-axis detection threshold of 43.27 mm/s and a y-axis detection threshold of 41.85 mm/s for the oscillatory air flow.
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Sánchez, Santiago, Victor Hidalgo, Martin Velasco, Diana Puga, P. Amparo López-Jiménez, and Modesto Pérez Sánchez. "Parametric study of a horizontal axis wind turbine with similar characteristics to those of the Villonaco wind power plant." Journal of Applied Research in Technology & Engineering 2, no. 2 (July 16, 2021): 51. http://dx.doi.org/10.4995/jarte.2021.15056.
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<p class="JAREAbstract">The present paper focuses on the selection of parameters that maximize electrical energy production of a horizontal axis wind turbine using Python programming language. The study takes as reference turbines of Villonaco wind field in Ecuador. For this aim, the Blade Element Momentum (BEM) theory was implemented, to define rotor geometry and power curve. Furthermore, wind speeds were analyzed using the Weibull probability distribution and the most probable speed was 10.50 m/s. The results were compared with mean annual energy production of a Villonaco’s wind turbine to validate the model. Turbine height, rated wind speed and rotor radius were the selected parameters to determine the influence in generated energy. Individual increment in rotor radius and rated wind speed cause a significant increase in energy produced. While the increment in turbine’s height reduces energy generated by 0.88%.</p>
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Punchihewa, Niroshan G., Shigeaki Miyazaki, Etsuo Chosa, and Go Yamako. "Efficacy of Inertial Measurement Units in the Evaluation of Trunk and Hand Kinematics in Baseball Hitting." Sensors 20, no. 24 (December 20, 2020): 7331. http://dx.doi.org/10.3390/s20247331.
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Baseball hitting is a highly dynamic activity, and advanced methods are required to accurately obtain biomechanical data. Inertial measurement units (IMUs) can capture the motion of body segments at high sampling rates both indoor and outdoor. The bat rotates around the longitudinal axis of the body; thus, trunk motion plays a key role in baseball hitting. Segmental coordination is important in transferring power to a moving ball and, therefore, useful in evaluating swing kinematics. The current study aimed to investigate the validity and reliability of IMUs with a sampling rate of 1000 Hz attached on the pelvis, thorax, and hand in assessing trunk and hand motion during baseball hitting. Results obtained using the IMU and optical motion capture system (OMCS) were compared. Angular displacements of the trunk segments and spine joint had a root mean square error of <5°. The mean absolute error of the angular velocities was ≤5%. The intra-class correlation coefficient (>0.950) had excellent reliability for trunk kinematics along the longitudinal-axis. Hand velocities at peak and impact corresponded to the values determined using the OMCS. In conclusion, IMUs with high sampling rates are effective in evaluating trunk and hand movement coordination during hitting motion.
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Saputri, Aditya Dwi, Dini Kurnia Ikliptikawati, and Fedri Rell. "Perbandingan Pemberian Anestesi Kombinasi Ketamin-Xilazin dengan Anestesi Propofol Terhadap Gambaran Elektrokardiogram pada Kucing Domestik." Indonesia Medicus Veterinus 9, no. 4 (July 31, 2020): 488–501. http://dx.doi.org/10.19087/imv.2020.9.4.488.
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Anestesi merupakan kondisi yang dikendalikan dengan ketidaksadaran yang bersifat reversible. Tujuan penelitian ini adalah untuk mengetahui perbandingan pemberian anestesi ketamin-xilazin dengan anestesi propofol terhadap gambaran elektrokardiogram (EKG) pada kucing domestik. Sebanyak 15 ekor kucing domestik berumur 1.5-3 tahun dan sehat. Kucing dibagi kedalam tiga kelompok yaitu kelompok kontrol (KK), kelompok perlakuan I (KP1), dan kelompok perlakuan 2 (KP2). Anestesi propofol diberikan pada KP1, kombinasi ketamin-xilazin diberikan pada KP2, dan tanpa pemberian anestesi pada KK. Pengambilan data EKG yang meliputi heart rate, durasi P, durasi QRS, durasi T, interval PR, interval QT, Amplitudo P dan Amplitudo R, serta MEA (mean electrical axis) pada kelompok perlakuan diambil pada stadium III. Kelompok KP1 memiliki nilai parameter yang lebih mendekati nilai normal daripada KP2. Berdasarkan hasil penelitian ini disimpulkan bahwa penggunaan anestesi propofol lebih aman daripada anestesi kombinasi ketamin-xilazin terhadap gambaran EKG jantung.
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Fice, Jason B., Gunter P. Siegmund, and Jean-Sébastien Blouin. "Neck muscle biomechanics and neural control." Journal of Neurophysiology 120, no. 1 (July 1, 2018): 361–71. http://dx.doi.org/10.1152/jn.00512.2017.
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The mechanics, morphometry, and geometry of our joints, segments, and muscles are fundamental biomechanical properties intrinsic to human neural control. The goal of our study was to investigate whether the biomechanical actions of individual neck muscles predict their neural control. Specifically, we compared the moment direction and variability produced by electrical stimulation of a neck muscle (biomechanics) to the preferred activation direction and variability (neural control). Subjects sat upright with their head fixed to a six-axis load cell and their torso restrained. Indwelling wire electrodes were placed into the sternocleidomastoid (SCM), splenius capitis (SPL), and semispinalis capitis (SSC) muscles. The electrically stimulated direction was defined as the moment direction produced when a current (2–19 mA) was passed through each muscle’s electrodes. Preferred activation direction was defined as the vector sum of the spatial tuning curve built from root mean squared electromyogram when subjects produced isometric moments at 7.5% and 15% of their maximum voluntary contraction (MVC) in 26 three-dimensional directions. The spatial tuning curves at 15% MVC were well defined (unimodal, P < 0.05), and their preferred directions were 23°, 39°, and 21° different from their electrically stimulated directions for the SCM, SPL, and SSC, respectively ( P < 0.05). Intrasubject variability was smaller in electrically stimulated moment directions compared with voluntary preferred directions, and intrasubject variability decreased with increased activation levels. Our findings show that the neural control of neck muscles is not based solely on optimizing individual muscle biomechanics but, as activation increases, biomechanical constraints in part dictate the activation of synergistic neck muscles. NEW & NOTEWORTHY Biomechanics are an intrinsic part of human neural control. In this study, we found that the biomechanics of individual neck muscles cannot fully predict their neural control. Consequently, physiologically based computational neck muscle controllers cannot calculate muscle activation schemes based on the isolated biomechanics of muscles. Furthermore, by measuring biomechanics we showed that the intrasubject variability of the neural control was lower for electrical vs. voluntary activation of the neck muscles.
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Ashikaga, Hiroshi, Steven R. Mickelsen, Daniel B. Ennis, Ignacio Rodriguez, Peter Kellman, Han Wen, and Elliot R. McVeigh. "Electromechanical analysis of infarct border zone in chronic myocardial infarction." American Journal of Physiology-Heart and Circulatory Physiology 289, no. 3 (September 2005): H1099—H1105. http://dx.doi.org/10.1152/ajpheart.00423.2005.
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To test the hypothesis that alterations in electrical activation sequence contribute to depressed systolic function in the infarct border zone, we examined the anatomic correlation of abnormal electromechanics and infarct geometry in the canine post-myocardial infarction (MI) heart, using a high-resolution MR-based cardiac electromechanical mapping technique. Three to eight weeks after an MI was created in six dogs, a 247-electrode epicardial sock was placed over the ventricular epicardium under thoracotomy. MI location and geometry were evaluated with delayed hyperenhancement MRI. Three-dimensional systolic strains in epicardial and endocardial layers were measured in five short-axis slices with motion-tracking MRI (displacement encoding with stimulated echoes). Epicardial electrical activation was determined from sock recordings immediately before and after the MR scans. The electrodes and MR images were spatially registered to create a total of 160 nodes per heart that contained mechanical, transmural infarct extent, and electrical data. The average depth of the infarct was 55% (SD 11), and the infarct covered 28% (SD 6) of the left ventricular mass. Significantly delayed activation (>mean + 2SD) was observed within the infarct zone. The strain map showed abnormal mechanics, including abnormal stretch and loss of the transmural gradient of radial, circumferential, and longitudinal strains, in the region extending far beyond the infarct zone. We conclude that the border zone is characterized by abnormal mechanics directly coupled with normal electrical depolarization. This indicates that impaired function in the border zone is not contributed by electrical factors but results from mechanical interaction between ischemic and normal myocardium.
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Ratchagar, Nirmala, and R. Kumar. "Effect of couple stress and magnetic field on the unsteady convective diffusion in blood flow." World Journal of Engineering 11, no. 4 (August 1, 2014): 403–12. http://dx.doi.org/10.1260/1708-5284.11.4.403.
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The effect of magnetic field on unsteady convective diffusion in a couple stress fluid (blood) is studied using a time dependent dispersion model. This model is used to calculate the mean concentration distribution of a solute, bounded by the porous layer and is expressed as a function of dimensionless axial distance and time. The magnetic field, arising as a body couple in the governing equations is shown to increase the axis dispersion coefficient. This is useful to the control of haemolysis caused by artificial organs implanted or extracorporeal. Dispersion coefficient and mean concentration are computed for different values of Hartmann number (M), Couple Stress Parameter (a) and Porous Parameter (σ).
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Zhang, Xiaoyue, and Wan Xiao. "A Fuzzy Tuned and Second Estimator of the Optimal Quaternion Complementary Filter for Human Motion Measurement with Inertial and Magnetic Sensors." Sensors 18, no. 10 (October 18, 2018): 3517. http://dx.doi.org/10.3390/s18103517.
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To accurately measure human motion at high-speed, we proposed a simple structure complementary filter, named the Fuzzy Tuned and Second EStimator of the Optimal Quaternion Complementary Filter (FTECF). The FTECF is applicable to inertial and magnetic sensors, which include tri-axis gyroscopes, tri-axis accelerometers, and tri-axis magnetometers. More specifically, the proposed method incorporates three parts, the input quaternion, the reference quaternion, and the fuzzy logic algorithm. At first, the input quaternion was calculated with gyroscopes. Then, the reference quaternion was calculated by applying the Second EStimator of the Optimal Quaternion (ESOQ-2) algorithm on accelerometers and magnetometers. In addition, we added compensation for accelerometers in the ESOQ-2 algorithm so as to eliminate the effects of limb motion acceleration in high-speed human motion measurements. Finally, the fuzzy logic was utilized to calculate the fusion factor for a complementary filter, so as to adaptively fuse the input quaternion with the reference quaternion. Additionally, the overall algorithm design is more simplified than traditional methods. Confirmed by the experiments, using a commercial inertial and magnetic sensors unit and an optical motion capture system, the efficiency of the proposed method was more improved than two well-known methods. The root mean square error (RMSE) of the FTECF was less than 2.2° and the maximum error was less than 5.4°.
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Szyszka-Sommerfeld, Liliana, Teresa Matthews-Brzozowska, Beata Kawala, Marcin Mikulewicz, Monika Machoy, Włodzimierz Więckiewicz, and Krzysztof Woźniak. "Electromyographic Analysis of Masticatory Muscles in Cleft Lip and Palate Children with Pain-Related Temporomandibular Disorders." Pain Research and Management 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/4182843.
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Aim. The aim of this study was to assess the electrical activity of temporalis and masseter muscles in children with cleft lip and palate (CLP) and pain-related temporomandibular disorders (TMD-P). Methods. The sample consisted of 31 CLP patients with a TMD-P (mean age 9.5 ± 1.8 years) and 32 CLP subjects with no TMD (mean age 9.2 ± 1.7 years). The children were assessed for the presence of temporomandibular disorders (TMD) using Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD). Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) in the mandibular rest position and during maximum voluntary contraction (MVC). Results. The rest activity of the temporalis and masseter muscles was significantly higher in TMD-P group compared with non-TMD children. A significant decrease in temporalis muscle activity during MVC was observed in TMD-P patients. There was a significant increase in the Asymmetry Index for temporalis and masseter muscle rest activity in the TMD-P group. Conclusion. Cleft children diagnosed with TMD-P have altered masticatory muscle activity, and this can affect their muscle function.
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Raoof, M. "Free bending fatique of axially pre-loaded spiral strands." Journal of Strain Analysis for Engineering Design 27, no. 3 (July 1, 1992): 127–36. http://dx.doi.org/10.1243/03093247v273127.
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The response of a large diameter and a multi-layered spiral strand to an applied moment is considered in some detail for a given mean axial load. Carefully conducted large-scale experiments have cast some light on an interesting phenomenon observed in previously reported bending fatigue experiments The first wire to fail was invariably the wire which entered the socket on the bending neutral axis rather than the wires in the ‘extreme fibre’ positions, as might usually be expected. Using a series of electrical resistance strain gauges placed on the individual wires at the mouth of the socket, the previously reported theoretical predictions that interwire slippage is greatest at the neutral axis (in terms of simple beam bending theory), and least at the extreme fibre positions, have been confirmed. In line with the theoretical predictions reported elsewhere, the test results show that, in general, the onset of deviations from no-slip interlayer shear interaction occurs at rather small levels of bending movements near the socket. Based on the theoretical and experimental findings, which identify interlayer fretting as the primary cause of wire fractures, a newly developed parameter capable of predicting spiral strand free bending fatigue life has been proposed. Unlike the traditional extreme fibre maximum direct stress approaches, the proposed parameter takes the interwire/interlayer fretting phenomenon into account.
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Marković, V. Lj, S. N. Stamenković, and S. R. Gocić. "Empirical and semiempirical models of the formative time delay in nitrogen." Canadian Journal of Physics 86, no. 7 (July 1, 2008): 947–51. http://dx.doi.org/10.1139/p08-028.
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The formative time dependence on working voltages tf(U) in nitrogen is determined: (1) from the Laue diagrams, by taking the values where the linear approximation of the electrical breakdown time delay (td) intersects the time axis, (2) from histograms, by taking the minimum values of the delay times for the formative time, and (3) from a difference tf = [Formula: see text] – [Formula: see text] ≈ [Formula: see text] – σ (td), where standard deviation σ,(td) is approximately equal to the mean of the statistical time delay [Formula: see text]. The breakdown time delay measurements are supported by oscilloscopic measurements of the voltage drop and the current rise time during inception of the discharge. Several simple models were applied to describe the experimental formative time dependence on working voltages tf,(U) and a good agreement with experimental data was found.PACS Nos.: 51.50.+v, 52.80.–s
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Prasad, Mattipally, Tata N. Rao, P. S. R. Prasad, and D. Suresh Babu. "Preparation of Bulk Graphene Nanoplatelets by Spark Plasma Sintering — Electrical and Thermal Properties." International Journal of Nanoscience 15, no. 05n06 (October 2016): 1660003. http://dx.doi.org/10.1142/s0219581x16600036.
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Consolidation of graphene nanoplatelets (GNPs) by spark plasma sintering (SPS) to study the feasibility of its structure retention at extreme temperature and pressure conditions. Structural characterization of the GNP powder and pellet were carried out by Micro-Raman, SEM, and TEM. HT-XRD. A.C. and D.C. conductivity of GNP pellet is carried out at room temperature. GNPs survived its structure in the SPS processing at an extreme temperature of 1850[Formula: see text]C and uni-axial pressure 60[Formula: see text]MPa, vacuum at [Formula: see text] Torr. Our study shows the potential for GNPs to be successfully used as a reinforcing in ceramic matrix composites using SPS. The diffraction has been accurately calibrated to waterfall the shift in 2[Formula: see text] values at elevated temperatures. The corrected lattice parameter data have been used to estimate the instantaneous and mean thermal expansion coefficients as a function of temperature. The lattice parameters “[Formula: see text]” and “[Formula: see text]” for powder and pellet GNP is found to be 0.2456(1)[Formula: see text]nm and 0.6700(2)[Formula: see text]nm, respectively. The thermal expansivity of GNP powder and pellet along “[Formula: see text]”- and “[Formula: see text]”-axis are found to be [Formula: see text][Formula: see text]K[Formula: see text], [Formula: see text][Formula: see text]K[Formula: see text] and [Formula: see text][Formula: see text]K[Formula: see text], [Formula: see text][Formula: see text]K[Formula: see text], respectively. Electrical conductivity of GNP pellet is found to be 5700[Formula: see text]S/m.
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Wittmann, Frieder, Olivier Lambercy, and Roger Gassert. "Magnetometer-Based Drift Correction During Rest in IMU Arm Motion Tracking." Sensors 19, no. 6 (March 15, 2019): 1312. http://dx.doi.org/10.3390/s19061312.
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Real-time motion capture of the human arm in the home environment has many usecases, such as video game and therapy applications. The required tracking can be based onoff-the-shelf Inertial Measurement Units (IMUs) with integrated three-axis accelerometers, gyroscopes,and magnetometers. However, this usually requires a homogeneous magnetic field to correctfor orientation drift, which is often not available inside buildings. In this paper, RPMC (RestPose Magnetometer-based drift Correction), a novel method that is robust to long term drift inenvironments with inhomogeneous magnetic fields, is presented. The sensor orientation is estimatedby integrating the angular velocity measured by the gyroscope and correcting drift around the pitchand roll axes with the acceleration information. This commonly leads to short term drift aroundthe gravitational axis. Here, during the calibration phase, the local magnetic field direction for eachsensor, and its orientation relative to the inertial frame, are recorded in a rest pose. It is assumed thatarm movements in free space are exhausting and require regular rest. A set of rules is used to detectwhen the user has returned to the rest pose, to then correct for the drift that has occurred with themagnetometer. Optical validations demonstrated accurate (root mean square error RMS = 6.1), lowlatency (61 ms) tracking of the user’s wrist orientation, in real time, for a full hour of arm movements.The reduction in error relative to three alternative methods implemented for comparison was between82.5% and 90.7% for the same movement and environment. Therefore, the proposed arm trackingmethod allows for the correction of orientation drift in an inhomogeneous magnetic field by exploitingthe user’s need for frequent rest.
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Krasuski, Kamil, and Janusz Ćwiklak. "Aircraft positioning using DGNSS technique for GPS and GLONASS data." Sensor Review 40, no. 5 (August 31, 2020): 559–75. http://dx.doi.org/10.1108/sr-12-2018-0327.
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Purpose The purpose of this paper is to present the problem of implementation of the differential global navigation satellite system (DGNSS) differential technique for aircraft accuracy positioning. The paper particularly focuses on identification and an analysis of the accuracy of aircraft positioning for the DGNSS measuring technique. Design/methodology/approach The investigation uses the DGNSS method of positioning, which is based on using the model of single code differences for global navigation satellite system (GNSS) observations. In the research experiment, the authors used single-frequency code observations in the global positioning system (GPS)/global navigation satellite system (GLONASS) system from the on-board receiver Topcon HiperPro and the reference station REF1 (reference station for the airport military EPDE in Deblin in south-eastern Poland). The geodetic Topcon HiperPro receiver was installed in Cessna 172 plane in the aviation test. The paper presents the new methodology in the DGNSS solution in air navigation. The aircraft position was estimated using a “weighted mean” scheme for differential global positioning system and differential global navigation satellite system solution, respectively. The final resultant position of aircraft was compared with precise real-time kinematic – on the fly solution. Findings In the investigations it was specified that the average accuracy of positioning the aircraft Cessna 172 in the geocentric coordinates XYZ equals approximately: +0.03 ÷ +0.33 m along the x-axis, −0.02 ÷ +0.14 m along the y-axis and approximately +0.02 ÷ −0.15 m along the z-axis. Moreover, the root mean square errors determining the measure of the accuracy of positioning of the Cessna 172 for the DGNSS differential technique in the geocentric coordinates XYZ, are below 1.2 m. Research limitations/implications In research, the data from GNSS onboard receiver and also GNSS reference receiver are needed. In addition, the pseudo-range corrections from the base stations were applied in the observation model of the DGNSS solution. Practical implications The presented research method can be used in a ground based augmentation system (GBAS) augmentation system, whereas the GBAS system is still not applied in Polish aviation. Social implications The paper is destined for people who work in the area of aviation and air transport. Originality/value The study presents the DGNSS differential technique as a precise method for recovery of aircraft position in civil aviation and this method can be also used in the positioning of aircraft based on GPS and GLONASS code observations.
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Shwetha, S. V., and L. Dharmanna. "A Literature Survey on Early Detection of Malignant Tumor Through Computerized Technique." Journal of Computational and Theoretical Nanoscience 17, no. 9 (July 1, 2020): 3873–77. http://dx.doi.org/10.1166/jctn.2020.8977.
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Computer based initial stage classification and detection of breast cancer tumor must be taken as one of the most important parameter to detect cancer in order to assist radiologist. In this paper an overview of current development of computer based detection system has been reviewed. The abnormalities identification and classification based on texture feature and shape of tumor, statistically diagnostic parameters (mean, mode, standard deviation, median etc.), Entropy based, Elliptical Normalized Circumference (ENC), C-means, K-means, Watershed Transformation, Ratio of Perimeter:Area (P :A), Ratio of major axis:minor axis (L:S) and Content Based Image Retrieval (CBIR) have been presented. In this paper the accuracy of the result obtained by various techniques such as texture based classification (80%), statistical parameters based classification (70%), shape based classification (86%), CBIR based classification (60%), etc. are presented. The various imaging techniques and dedicated databases publicly available for the cancer research work have been listed, discussed and reported in this paper.
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Uscategui, Ricardo A. R., Vívian T. Almeida, Aline E. Kawanami, Wilmer A. Z. Restan, Felipe F. P. C. Barros, Marcus A. R. Feliciano, Márcia R. F. Machado, and Wilter R. R. Vicentte. "Electrocardiographic exam in female spotted pacas (Cuniculus paca)." Pesquisa Veterinária Brasileira 36, no. 6 (June 2016): 559–63. http://dx.doi.org/10.1590/s0100-736x2016000600016.
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Abstract: Considering the limited physiological information available on neotropical rodents and the importance of this information for pathophysiological and conservation studies of these species, the aim of this study was to evaluate the cardiac electric physiology of healthy captivity spotted pacas (Cuniculus paca) under chemical restraint, due to wild nature of these animals. Eleven adult female pacas were evaluated by blood count and biochemical dosage to rule out any associate disease. Each animal was evaluated in three periods every 15 days. After chemical restraint with intramuscular midazolam 0.5mg/kg and ketamine 25mg/kg, animals were subjected to a computerized electrocardiogram, where bipolar (DI, DII and DIII) and augmented unipolar leads (aVR, aVL, aVF) were obtained. Descriptive statistics were calculated for each parameter and built the confidence interval (CI) at significance level of 95%. The electrocardiographic examination was performed without difficult. ECG tracing in DII represents a QRS complex with positive polarity, preceded by a P wave of the same polarity and proceeded by T wave of variable polarity. Heart rate mean was 150±17 bpm, and cardiac electrical axis 33.4±21.9°. All animals showed sinusal rhythm. The ECG recording technique associated with chemical restraint was well tolerated, allowing quick acquisition of reliable ECG tracings with high repeatability, which produced sufficient results to determine the heart rhythm and suggest measures of ECG complexes duration and amplitude.
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CHEN, C. W., C. H. TSENG, C. Y. HSU, C. P. CHOU, and K. H. HOU. "GROWTH OF AZO FILMS ON BUFFER LAYERS BY RF MAGNETRON SPUTTERING." Modern Physics Letters B 24, no. 31 (December 20, 2010): 3033–40. http://dx.doi.org/10.1142/s0217984910025097.
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Al 2 O 3-doped zinc oxide (in AZO, the Al 2 O 3 contents are approximately 2 wt.%) films have been grown by radio frequency (RF) magnetron sputtering at room temperature under varied sputtering pressures ranging from 3.5–15 mTorr. The electrical resistivity of AZO films is about 2.22×10-3 Ωcm (sheet resistance ~ 89 Ω/square for a thickness ~ 250 nm), and the visible range transmittance is about 80% at the argon sputtering pressure of 15 mTorr and a RF power of 100 W. This study analyzes the structural, morphological, electrical and optical properties of AZO thin films grown on soda-lime glass substrate with 2, 5, and 10 nm thick Al buffer layers (and SiO 2 buffer). For the films deposited on the 2 nm thick Al buffer layer, we obtained a c-axis-oriented AZO/ Al thin film on glass with the XRD full-width at half maximum (FWHM) of 0.31 and root mean square (RMS) surface roughness of about 3.22 nm. The lowest resistivity of 9.46×10-4 Ωcm (sheet resistance ~ 37.87 Ω/square for a thickness ~ 250 nm) and a high transmittance (80%) were obtained by applying a 2 nm thick Al buffer layer. In contrast, the resistivity was slightly increased by applying the SiO 2 buffer layer.
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Spencer, Nick J., Grant W. Hennig, and Terence K. Smith. "Electrical rhythmicity and spread of action potentials in longitudinal muscle of guinea pig distal colon." American Journal of Physiology-Gastrointestinal and Liver Physiology 282, no. 5 (May 1, 2002): G904—G917. http://dx.doi.org/10.1152/ajpgi.00345.2001.
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Using simultaneous intracellular recordings, we have characterized 1) electrical activity in the longitudinal muscle (LM) of isolated segments of guinea pig distal colon free to contract spontaneously and 2) extent of propagation of spontaneous action potentials around the circumference of the colon. In all animals, rhythmical spontaneous depolarizations (SDs) were recorded that are usually associated with the generation of action potentials. Recordings from pairs of LM cells, separated by 100 μm in the circumferential axis, revealed that each action potential was phase locked at the two electrodes (mean propagation velocity: 3 mm/s). However, at an increased electrode separation distance of 1 mm circumferentially, action potentials and SDs became increasingly uncoordinated at the two recording sites. No SDs or action potentials ever propagated from one circumferential edge to the other (i.e., 13 mm apart). When LM strips were separated from the myenteric plexus and circular muscle, rhythmically firing SDs and action potentials were still recorded. Atropine (1 μM) or tetrodotoxin (1 μM) either reduced the frequency of SDs or temporily abolished activity, whereas nifedipine (1 μM) always abolished SDs and action potentials. Kit-positive interstitial cells of Cajal were present at the level of the myenteric plexus and circular and longitudinal muscle. In summary, SDs and action potentials in LM propagate over discrete localized zones, usually <1 mm around the circumference of the colon. Furthermore, in contrast to the classic slow wave, rhythmic depolarizations in LM appear to be generated by an intrinsic property of the smooth muscle itself and are critically dependent on opening of L-type Ca2+ channels.
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Martínez, Aaron, Rüdiger Jahnel, Michael Buchecker, Cory Snyder, Richard Brunauer, and Thomas Stöggl. "Development of an Automatic Alpine Skiing Turn Detection Algorithm Based on a Simple Sensor Setup." Sensors 19, no. 4 (February 21, 2019): 902. http://dx.doi.org/10.3390/s19040902.
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In order to gain insight into skiing performance, it is necessary to determine the point where each turn begins. Recent developments in sensor technology have made it possible to develop simpler automatic turn detection methodologies, however they are not feasible for regular use. The aim of this study was to develop a sensor set up and an algorithm to precisely detect turns during alpine ski, which is feasible for a daily use. An IMU was attached to the posterior upper cuff of each ski boot. Turn movements were reproduced on a ski-ergometer at different turn durations and slopes. Algorithms were developed to analyze vertical, medio-lateral, anterior-posterior axes, and resultant accelerometer and gyroscope signals. Raw signals, and signals filtered with 3, 6, 9, and 12 Hz cut-offs were used to identify turn switch points. Video recordings were assessed to establish a reference turn-switch and precision (mean bias = 5.2, LoA = 51.4 ms). Precision was adjusted based on reference and the best signals were selected. The z-axis and resultant gyroscope signals, filtered at 3Hz are the most precise signals (0.056 and 0.063 s, respectively) to automatically detect turn switches during alpine skiing using this simple system.
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Suzuki, N., C. L. Prosser, and W. DeVos. "Waxing and waning of slow waves in intestinal musculature." American Journal of Physiology-Gastrointestinal and Liver Physiology 250, no. 1 (January 1, 1986): G28—G34. http://dx.doi.org/10.1152/ajpgi.1986.250.1.g28.
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Electrical slow waves from cat or rabbit small intestine show more variability when recorded in vivo than in vitro. One pattern of variation is waxing and waning of amplitude, or "spindling," during which two rhythms of slightly different frequency come in and out of phase. Fourier power analyses of slow waves during spindles show two frequency peaks of slow waves differing by 0.4-5.0 waves/min and corresponding to measured spindle durations of 12-150 s. Spindles can be induced in vitro in rabbit intestine by K depolarization of approximately 15 mV. Histograms of intracellular recordings of slow nonspindling waves show variation of 0.5-1.0 s on either side of a mean slow wave duration. Spindles are abolished by treatments that reduce electrical coupling between cells, e.g., hypertonic sucrose or lowered pH, but changes in calcium do not alter spindles. Simultaneous recordings by two electrodes in the longitudinal axis show synchrony of spindles at 2- to 3-mm but not at 5-mm separation and synchrony circumferentially to the opposite side of a segment. Contractions, both in vivo and in vitro, correspond with electrical spindles in amplitude. Spindle durations were significantly shorter in vivo than in vitro, indicating a significantly greater difference in vivo in the competing frequencies at the point of recording (P less than 0.01). Three conditions favoring waxing and waning are slight depolarization, variation in slow wave frequency at a point, and electrotonic coupling between muscle fibers. Spindles provide for rhythms of contractions of a 1- to 2-min period.
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Marlinski, Vladimir, and Robert A. McCrea. "Self-Motion Signals in Vestibular Nuclei Neurons Projecting to the Thalamus in the Alert Squirrel Monkey." Journal of Neurophysiology 101, no. 4 (April 2009): 1730–41. http://dx.doi.org/10.1152/jn.90904.2008.
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Sixty vestibular nuclei neurons antidromically activated by electrical stimulation of the ventroposterior thalamus were recorded in two alert squirrel monkeys. The majority of these neurons were monosynaptically activated by vestibular nerve electrical stimulation. Forty-seven neurons responded to animal rotations around the earth-vertical axis; 16 of them also responded to translations in the horizontal plane. The mean sensitivity to 0.5-Hz rotations of 80°/s velocity was 0.40 ± 0.31 spikes·s−1·deg−1·s−1. Rotational responses were in phase with stimulus velocity. Sensitivities to 0.5-Hz translations of 0.1 g acceleration varied from 92.2 to 359 spikes·s−1· g−1 and response phases varied from 10.1° lead to −98° lag. The firing behavior in 28 neurons was studied during rotation of the whole animal, of the trunk, and voluntary and involuntary rotations of the head. Two classes of vestibulothalamic neurons were distinguished. One class of neurons generated signals related to movement of the head that were similar either when the head and trunk move together or when the head moves on the stationary trunk. A fraction of these neurons fired during involuntary head movements only. A second class of neurons generated signals related to movement of the trunk. They responded when the trunk moved alone or simultaneously with the head, but did not respond to head rotations while the trunk was stationary.
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Constable, P. D., K. W. Hinchcliff, J. Olson, and R. L. Hamlin. "Athletic heart syndrome in dogs competing in a long-distance sled race." Journal of Applied Physiology 76, no. 1 (January 1, 1994): 433–38. http://dx.doi.org/10.1152/jappl.1994.76.1.433.
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The cardiac effects of endurance training were evaluated by cardiac auscultation and electrocardiographic examination of 48 heavily trained sled dogs (3,000–5,000 km of training), 18 lightly trained sled dogs (300–800 km of training), 19 untrained sled dogs, and 14 mongrel dogs. A grade I-II/VI early- to midsystolic cardiac murmur was auscultated with increasing frequency as training level increased. The QRS duration (66.1 +/- 7.4 ms) and QT interval (236 +/- 20 ms) were significantly (P < 0.05) longer in heavily trained sled dogs than in mongrel dogs (QRS, 60.6 +/- 4.6; QT, 219 +/- 11 ms). A long QT interval (> 250 ms) was observed in 8 (16.7%) heavily trained dogs but not in the other groups. A significant rightward shift in the mean electrical axis of ventricular depolarization in the frontal plane was observed in heavily trained sled dogs. The auscultatory and electrocardiographic findings in heavily trained sled dogs were remarkably similar to those reported in elite human endurance athletes, suggesting that endurance-trained sled dogs provide a naturally occurring model for the athletic heart syndrome.
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Hara, Yutaka, Yoshifumi Jodai, Tomoyuki Okinaga, and Masaru Furukawa. "Numerical Analysis of the Dynamic Interaction between Two Closely Spaced Vertical-Axis Wind Turbines." Energies 14, no. 8 (April 19, 2021): 2286. http://dx.doi.org/10.3390/en14082286.
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To investigate the optimum layouts of small vertical-axis wind turbines, a two-dimensional analysis of dynamic fluid body interaction is performed via computational fluid dynamics for a rotor pair in various configurations. The rotational speed of each turbine rotor (diameter: D = 50 mm) varies based on the equation of motion. First, the dependence of rotor performance on the gap distance (gap) between two rotors is investigated. For parallel layouts, counter-down (CD) layouts with blades moving downwind in the gap region yield a higher mean power than counter-up (CU) layouts with blades moving upwind in the gap region. CD layouts with gap/D = 0.5–1.0 yield a maximum average power that is 23% higher than that of an isolated single rotor. Assuming isotropic bidirectional wind speed, co-rotating (CO) layouts with the same rotational direction are superior to the combination of CD and CU layouts regardless of the gap distance. For tandem layouts, the inverse-rotation (IR) configuration shows an earlier wake recovery than the CO configuration. For 16-wind-direction layouts, both the IR and CO configurations indicate similar power distribution at gap/D = 2.0. For the first time, this study demonstrates the phase synchronization of two rotors via numerical simulation.
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Gözde, Haluk, and Semih Ozden. "Adaptive True Proportional Navigation Guidance Based On Heuristic Optimization Algorithms." Defence Science Journal 71, no. 2 (March 10, 2021): 271–81. http://dx.doi.org/10.14429/dsj.71.16218.
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The PN-guidance (Proportional Guidance) still continues to be improved, because it is the simplest, cheapest and most reliable algorithm. One of the most important techniques to improve PN-guidance is to adapt the navigation constant depending on time. In this study, first, the entire adaptation methods for PN-guidance are classified, then the adaptation process is online achieved by using heuristic optimization during guiding the missile. The novelty of this study is that the heuristic optimization approach is used at the first time to update the navigation constant of PN-guidance. It is considered that having short program code, fast convergence speed and just simple algebraic computations without derivative are vital advantages of heuristic algorithms using into missile systems. In this scope, an Adaptive True-PN (ATPN) guidance algorithm is designed by optimizing navigation constants varying according to the target behavior. The results show that while the acceleration gap of the pitch axis decreases 21.8%, the acceleration gap of yaw axis reduces 39.68%. These reductions mean that while the missile guided by ATPN is maneuvering, it is exposed to less acceleration and less strain.
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Zawadzki, Tadeusz. "Passive electrical properties of Lupinus angustifolius L. stem TV. The core-conductor theory parametres: space constant λ and time constant τ." Acta Societatis Botanicorum Poloniae 48, no. 3 (2015): 453–64. http://dx.doi.org/10.5586/asbp.1979.036.
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On the basis of the core-conductor theory and the method described by Hodgkin and Rushton (1946) for the axon, the space constant K and the time constant T have been determined for the stem of <i>Lupinus</i>. Electrotonic potentials were recorded in the extrapolar region in the vicinity of the cathode along the longitudinal axis of the stem. Extracellular recording electrodes were applied. It was found that the steady-state distribution of potential along the stem surface is of exponential character. The calculated space constant K has a value of 2.0 to 2.4 mm (average 2.1 mm) and is almost identical with the X values for nerves and muscles (mean 1.5-2.0 mm). The values of the time constants ("half-time") of electrotonic potentials increase linearly with the distance from the cathode. The time constant τ calculated on this basis is on the average 5.2 sec and as compared with τ for nerves and muscles is 103 times higher. The phenomena observed in the <i>Lupinus</i> stem fulfill the equations of the core-conductor theory (Appendix). Their character is identical to that of the phenomena noted in nerves or muscles. It is probable that they occur on the membrane of excitable cells of the stem. The results here presented are a, convincing argument indicating that in higher plants an excitable system may exist, subjected to the same laws as that in animal organisms.
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Cartón-Llorente, Antonio, Felipe García-Pinillos, Jorge Royo-Borruel, Alberto Rubio-Peirotén, Diego Jaén-Carrillo, and Luis E. Roche-Seruendo. "Estimating Functional Threshold Power in Endurance Running from Shorter Time Trials Using a 6-Axis Inertial Measurement Sensor." Sensors 21, no. 2 (January 15, 2021): 582. http://dx.doi.org/10.3390/s21020582.
Full textAbstract:
Wearable technology has allowed for the real-time assessment of mechanical work employed in several sporting activities. Through novel power metrics, Functional Threshold Power have shown a reliable indicator of training intensities. This study aims to determine the relationship between mean power output (MPO) values obtained during three submaximal running time trials (i.e., 10 min, 20 min, and 30 min) and the functional threshold power (FTP). Twenty-two recreationally trained male endurance runners completed four submaximal running time trials of 10, 20, 30, and 60 min, trying to cover the longest possible distance on a motorized treadmill. Absolute MPO (W), normalized MPO (W/kg) and standard deviation (SD) were calculated for each time trial with a power meter device attached to the shoelaces. All simplified FTP trials analyzed (i.e., FTP10, FTP20, and FTP30) showed a significant association with the calculated FTP (p < 0.001) for both MPO and normalized MPO, whereas stronger correlations were found with longer time trials. Individual correction factors (ICF% = FTP60/FTPn) of ~90% for FTP10, ~94% for FTP20, and ~96% for FTP30 were obtained. The present study procures important practical applications for coaches and athletes as it provides a more accurate estimation of FTP in endurance running through less fatiguing, reproducible tests.
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Esposito, Daniele, Sergio Savino, Chiara Cosenza, Emilio Andreozzi, Gaetano Dario Gargiulo, Caitlin Polley, Giuseppe Cesarelli, Giovanni D’Addio, and Paolo Bifulco. "Evaluation of Grip Force and Energy Efficiency of the “Federica” Hand." Machines 9, no. 2 (January 27, 2021): 25. http://dx.doi.org/10.3390/machines9020025.
Full textAbstract:
The actual grip force provided by a hand prosthesis is an important parameter to evaluate its efficiency. To this end, a split cylindrical handlebar embedding a single-axis load cell was designed, 3D printed and assembled. Various measurements were made to evaluate the performances of the “Federica” hand, a simple low-cost hand prosthesis. The handlebar was placed at different angular positions with respect to the hand palm, and the experimental data were processed to estimate the overall grip force. In addition, piezoresistive force sensors were applied on selected phalanxes of the prosthesis, in order to map the distribution of the grasping forces between them. The electrical current supplied to the single servomotor that actuates all the five fingers, was monitored to estimate the force exerted on the main actuator tendon, while tendon displacement was evaluated by a rotary potentiometer fixed to the servomotor shaft. The force transfer ratio of the whole system was about 12.85 %, and the mean dissipated energy for a complete cycle of closing-opening was 106.80 Nmm, resulting lower than that of many commercial prostheses. The mean grip force of the “Federica” hand was 8.80 N, that is enough to support the user in many actions of daily life, also considering the adaptive wrapping capability of the prosthesis. On average, the middle phalanges exerted the greatest grip force (2.65 N) on the handlebar, while the distal phalanges a force of 1.66 N.
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Jia, Jidong, Minglu Zhang, Xizhe Zang, He Zhang, and Jie Zhao. "Dynamic Parameter Identification for a Manipulator with Joint Torque Sensors Based on an Improved Experimental Design." Sensors 19, no. 10 (May 15, 2019): 2248. http://dx.doi.org/10.3390/s19102248.
Full textAbstract:
As the foundation of model control, robot dynamics is crucial. However, a robot is a complex multi-input–multi-output system. System noise seriously affects parameter identification results, thereby inevitably requiring us to conduct signal processing to extract useful signals from chaotic noise. In this research, the dynamic parameters were identified on the basis of the proposed multi-criteria embedded optimization design method, to obtain the optimal excitation signal and then use maximum likelihood estimation for parameter identification. Considering the movement coupling characteristics of the multi-axis, experiments were based on a two degrees-of-freedom manipulator with joint torque sensors. Simulation and experimental results showed that the proposed method can reasonably resolve the problem of mutual opposition within a single criterion and improve the identification robustness in comparison with other optimization criteria. The mean relative standard deviation was 0.04 and 0.3 lower in the identified parameters than in F1 and F3, respectively, thus signifying that noise is effectively alleviated. In addition, validation experimental curves were close to the estimation model, and the average of root mean square (RMS) is 0.038, thereby confirming the accuracy of the proposed method.
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Li, Yung-Hui, Wenny Ramadha Putri, Muhammad Saqlain Aslam, and Ching-Chun Chang. "Robust Iris Segmentation Algorithm in Non-Cooperative Environments Using Interleaved Residual U-Net." Sensors 21, no. 4 (February 18, 2021): 1434. http://dx.doi.org/10.3390/s21041434.
Full textAbstract:
Iris segmentation plays an important and significant role in the iris recognition system. The prerequisite for accurate iris recognition is the correctness of iris segmentation. However, the efficiency and robustness of traditional iris segmentation methods are severely challenged in a non-cooperative environment because of unfavorable factors, for instance, occlusion, blur, low resolution, off-axis, motion, and specular reflections. All of the above factors seriously reduce the accuracy of iris segmentation. In this paper, we present a novel iris segmentation algorithm that localizes the outer and inner boundaries of the iris image. We propose a neural network model called “Interleaved Residual U-Net” (IRUNet) for semantic segmentation and iris mask synthesis. The K-means clustering is applied to select saliency points set in order to recover the outer boundary of the iris, whereas the inner border is recovered by selecting another set of saliency points on the inner side of the mask. Experimental results demonstrate that the proposed iris segmentation algorithm can achieve the mean IOU value of 98.9% and 97.7% for inner and outer boundary estimation, respectively, which outperforms the existing approaches on the challenging CASIA-Iris-Thousand database.