scholarly journals Perception by Palpation: Development and Testing of a Haptic Ferrogranular Jamming Surface

2021 ◽  
Vol 8 ◽  
Author(s):  
Sigurd Bjarne Rørvik ◽  
Marius Auflem ◽  
Henrikke Dybvik ◽  
Martin Steinert
Keyword(s):  
Permanent Magnets ◽  
Pneumatic System ◽  
Psychophysical Experiment ◽  
Training Device ◽  
Vacuum Level ◽  
Geometric Shapes ◽  
System A ◽  
Actual Shape

Tactile hands-only training is particularly important for medical palpation. Generally, equipment for palpation training is expensive, static, or provides too few study cases to practice on. We have therefore developed a novel haptic surface concept for palpation training, using ferrogranular jamming. The concept’s design consists of a tactile field spanning 260 x 160 mm, and uses ferromagnetic granules to alter shape, position, and hardness of palpable irregularities. Granules are enclosed in a compliant vacuum-sealed chamber connected to a pneumatic system. A variety of geometric shapes (output) can be obtained by manipulating and arranging granules with permanent magnets. The tactile hardness of the palpable output can be controlled by adjusting the chamber’s vacuum level. A psychophysical experiment (N = 28) investigated how people interact with the palpable surface and evaluated the proposed concept. Untrained participants characterized irregularities with different position, form, and hardness through palpation, and their performance was evaluated. A baseline (no irregularity) was compared to three irregularity conditions: two circular shapes with different hardness (Hard Lump and Soft Lump), and an Annulus shape. 100% of participants correctly identified an irregularity in the three irregularity conditions, whereas 78.6% correctly identified baseline. Overall agreement between participants was high (κ= 0.723). The Intersection over Union (IoU) for participants sketched outline over the actual shape was IoU Mdn = 79.3% for Soft Lump, IoU Mdn = 68.8% for Annulus, and IoU Mdn = 76.7% for Hard Lump. The distance from actual to drawn center was Mdn = 6.4 mm (Soft Lump), Mdn = 5.3 mm (Annulus), and Mdn = 7.4 mm (Hard Lump), which are small distances compared to the size of the field. The participants subjectively evaluated Soft Lump to be significantly softer than Hard Lump and Annulus. Moreover, 71% of participants thought they improved their palpation skills throughout the experiment. Together, these results show that the concept can render irregularities with different position, form, and hardness, and that users are able to locate and characterize these through palpation. Participants experienced an improvement in palpation skills throughout the experiment, which indicates the concepts feasibility as a palpation training device.

scholarly journals IMPROVEMENTS ON THE ELECTRIC DRIVE ELEVATOR PROTOTYPE. PART II OPERATING TESTS

2018 ◽  
Vol 18 (1) ◽  
pp. 49-54 ◽  
Author(s):  
M. Gaiceanu ◽  
S. Epure
Keyword(s):  
Power Factor ◽  
Electric Drive ◽  
Permanent Magnets ◽  
Power Converters ◽  
Power Converter ◽  
Unity Power Factor ◽  
System A ◽  
Three Phase ◽  
Industrial Solution ◽  
Adequate Power

Abstract The prototype of the electric elevator consists of grid power converter connected with three different loads through the adequate power converters [1]. The main objective of this paper is to develop the industrial solution of the regenerative elevator power system, a system containing DC machines, asynchronous three-phase and synchronous with permanent magnets motors. In this paper, only the improvements done on the three-phase power inverter connected to the induction motor will be described. The same improvements can be applied to the three-phase power inverter connected to the synchronous machine. The grid power converter assures the unity power factor operation. The resulted experimental results are shown.

scholarly journals A Pattern-Based Approach for Detecting Pneumatic Failures on Temporary Immersion Bioreactors

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 414 ◽  
Author(s):  
Octavio Loyola-González ◽  
Miguel Medina-Pérez ◽  
Dayton Hernández-Tamayo ◽  
Raúl Monroy ◽  
Jesús Carrasco-Ochoa ◽  
...  
Keyword(s):  
Production Cost ◽  
Biological Process ◽  
Feature Representation ◽  
Pneumatic System ◽  
Temporary Immersion Bioreactor ◽  
Temporary Immersion ◽  
System A ◽  
Contrast Pattern ◽  
Bioreactor System ◽  
Feature Values

Temporary Immersion Bioreactors (TIBs) are used for increasing plant quality and plant multiplication rates. These TIBs are actioned by mean of a pneumatic system. A failure in the pneumatic system could produce severe damages into the TIB. Consequently, the whole biological process would be aborted, increasing the production cost. Therefore, an important task is to detect failures on a temporary immersion bioreactor system. In this paper, we propose to approach this task using a contrast pattern based classifier. We show that our proposal, for detecting pneumatic failures in a TIB, outperforms other approaches reported in the literature. In addition, we introduce a feature representation based on the differences among feature values. Additionally, we collected a new pineapple micropropagation database for detecting four new types of pneumatic failures on TIBs. Finally, we provide an analysis of our experimental results together with experts in both biotechnology and pneumatic devices.

scholarly journals Dynamic Vibration Absorber with Negative Stiffness for Rotor System

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Hongliang Yao ◽  
Zidong Chen ◽  
Bangchun Wen
Keyword(s):  
Permanent Magnets ◽  
Vibration Suppression ◽  
Rotor System ◽  
Negative Stiffness ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Suppression Effect ◽  
System A ◽  
Control Frequency ◽  
Nonlinear Dynamic Characteristics

To suppress the vibration of a rotor system, a vibration absorber combining negative stiffness with positive stiffness together is proposed in this paper. Firstly, the negative stiffness producing mechanism using ring type permanent magnets is presented and the characteristics of the negative stiffness are analyzed. Then, the structure of the absorber is proposed; the principles and nonlinear dynamic characteristics of the absorber-rotor system are studied numerically. Finally, experiments are carried out to verify the numerical conclusions. The results show that the proposed vibration absorber is effective to suppress the vibration of the rotor system, the nonlinearity of the negatives stiffness affects the vibration suppression effect little, and the negative stiffness can broaden the effective vibration control frequency range of the absorber.

A facility for charged photoparticle experiments

1969 ◽  
Vol 47 (6) ◽  
pp. 611-615 ◽  
Author(s):  
N. K. Keller ◽  
J. K. P. Lee ◽  
D. B. McConnell
Keyword(s):  
Charged Particle ◽  
Permanent Magnets ◽  
Experimental Arrangement ◽  
Low Background ◽  
System A ◽  
Scattering Chamber

A low-background experimental arrangement for (γ, charged particle) reactions is described. Studies on the nature and sources of the background indicated that best results could be obtained through complete shielding, a paraffin lining in the scattering chamber, and the use of permanent magnets for electron sweeping. To demonstrate the capability of the system, a photoproton spectrum at 90° is presented for the 16O(γ, p)15N reaction.

A representation of the SmCoZrCuFe quinary system: a tool for optimisation of permanent magnets

1997 ◽  
Vol 262-263 ◽  
pp. 129-133 ◽  
Author(s):  
A. Lefèvre ◽  
L. Cataldo ◽  
M.Th. Cohen-Adad ◽  
B.F. Mentzen
Keyword(s):  
Permanent Magnets ◽  
System A ◽  
Quinary System

Development and Use of a Stereoscopic System in Stereometry Training

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Penyo Lebamovski ◽  
◽  
◽  
Keyword(s):  
Training System ◽  
Control Points ◽  
Training Module ◽  
Geometric Shapes ◽  
System A ◽  
The Matrix ◽  
Stereoscopic System ◽  
Quadratic Bézier Curve ◽  
Testing Module ◽  
Stereoscopic Visualization

This article briefly presents how the StereoMV mathematical software is designed and used. It consists of five modules: interface, stereoscopic visualization, stereometry, training module and knowledge testing module. The stereoscopic system is research-oriented and designed for the presented modules. The purpose of the system is to allow students to control, observe and manipulate geometric shapes in space. StereoMV is part of a dissertation on the following topic: “Stereoscopic Training System”. A new boundary method, created by the author of the system, is used to generate geometric shapes. This method takes part in the generation of a circle by means of a quadratic Bézier curve using three control points. The use of the matrix calculus, which plays a role in the generation of geometric shapes and the performance of transformations, is of particular importance in the development of the system.

scholarly journals Frequency Enhancement of Oil Whip and Oil Whirl in a Ferrofluid–Lubricated Hydrodynamic Bearing–Rotor System by Magnetic Field with Permanent Magnets

2018 ◽  
Vol 8 (9) ◽  
pp. 1687
Author(s):  
Liao-Yong Luo ◽  
Yi-Hua Fan ◽  
Jyh-Haw Tang ◽  
Ting-Yu Chen ◽  
Nai-Rong Zhong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
Journal Bearing ◽  
Rotor System ◽  
Hydrodynamic Bearing ◽  
System A ◽  
Oil Whip ◽  
Oil Whirl ◽  
Hydrodynamic Journal Bearing ◽  
Whirl Speed

The article describes the effect of a magnetic field applied to a ferrofluid–lubricated hydrodynamic journal bearing–rotor system. A rotor with a single journal bearing in one end was built to be the test rig. The experimental results showed that 3 to 8 permanent magnets, arranged by different methods, can all increase the instability threshold of the oil bearing. Especially, the magnetic field formed by eight magnets has the optimal effect. The whirl speed and the whip speed can be increased from 3024 rpm to 4480 rpm, and from 3184 rpm to 5268 rpm.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

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