A practical use of experimentally observed changes in air pressure near conductor with electric current

2021 ◽  
Author(s):  
N.N. Usmanov ◽  
D.L. Stolyarov ◽  
I.R. Prudnikov ◽  
V.Y. Ivanov ◽  
A.M. Saletsky
Keyword(s):  
Electric Current ◽  
Current Pulse ◽  
Electric Circuit ◽  
Pressure Change ◽  
Air Pressure ◽  
Elastic Membrane ◽  
Environmental Pressure ◽  
Current Pulses ◽  
One To One ◽  
Pressure Changes

The possibility of practical application of the results of investigations of air environmental pressure changes in the vicinity of a conductor in which electric current flows is shown. The one-to-one match of environmental pressure changes to alterations of electric current can be applied under transfer of a regulated movement to mobile parts of micro and nanodevices. In accordance with the trends in the development of fields science and industry that require precision accuracy, the modes of small controlled movements of working parts are of greatest interest. When the same current pulses are fed into electric circuit of the described device, the rapid alterations of the pressure are well repeated. The correspondence is observed in a wide range of electric current amplitude and pressure values. The observed peculiarities of the pressure change were used for a regulated shift of the miniaturized holder. In the experiments, when the current in the conductor was altered, the air pressure in the pipe changed resulting in the motion of membrane and the holder that was fixed on it. Small shifts were monitored in microscope. For a convenience to watch the movements of the holder, a glass plate with a defect was placed beneath the holder. Upon a start of a current pulse, the pressure in the working pipe volume increased and by the action onto the elastic membrane caused the movement of the holder fixed on the membrane. When the pulse started, the holder rapidly reached a maximal value of the shift. After reaching the maximal value of the shift, the position of the holder remained almost unchangeable. After turning off the current pulse the holder went back to its original position. The controlled motion of the holder shown in the paper is in the range from less than 2 up to 200 microns. At lower values of pulse current amplitudes, the movement of the holder is less. The consistency of the results was determined solely by the parameters of the electric current pulse. The movements less than 1 micron became possible by applying small values of the current amplitudes. The experiment was carried out in which a plastic cylinder with the inner diameter c.a. 8 mm was attached to the tap of the glass pipe. The teflon piston was installed inside the cylinder, with the ability of free movement inside this cylinder. When a series of current pulses were supplied to the electric circuit from a signals generator, the piston made fast reciprocating motions, which could be easily watched visually. The results of the performed investigations suggest the possibility of widespread use of the effect of the fast pressure change of air environment near the conductor upon current alteration for solving scientific and technical problems. It is possible to create new devices, among others for nanotechnologies, which have great advantages in comparison with existing ones. One can obviously predict application for the creation of micro- and nano-instruments what has a great importance up to date. The simplicity of making such instruments lets us consider that the effect of one-to-one match of the pressure change to the electric current alterations in the working camera is prospective.

Effect of electric current pulse type on springback, microstructure, texture, and mechanical properties during V-bending of AA2024 aluminum alloy

2020 ◽  
pp. 1-36
Author(s):  
Nafiseh Mohammadtabar ◽  
Mohammad Bakhshi-jooybari ◽  
Hamid Gorji ◽  
Roohollah Jamaati ◽  
Jerzy A. Szpunar
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electric Current ◽  
Current Pulse ◽  
Fiber Texture ◽  
Electric Current Pulse ◽  
Electric Pulses ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Pulse Type

Abstract The present work focused on the effect of the electric current pulse type on the springback, microstructure, texture, and mechanical properties during the V-bending process of AA2024 aluminum alloy. In order to investigate this effect, three different forming conditions including conventional V-bending and electrically assisted V-bending with square and sinusoidal pulses were considered. The results indicated that the amount of springback significantly decreased from 45.5° (for the sample formed via conventional V-bending) to 24° by applying the sinusoidal pulse. Microstructural observations revealed lower stored energy in the samples formed by electric current pulses which resulted in larger grain size compared to the samples formed without electric pulses. In addition, the result showed that the intensity of the (111)||BLD (bend line direction) fiber texture reduced after applying electric current pulses whereas it was very strong in the sample formed without electric pulses. It was suggested that the electric current pulses led to change the slip plane of the dislocations from {111} to {110} through cross slip. The applying electric current pulses decrease the ultimate tensile strength (UTS) from 471.1 MPa (for the conventional tensile test) to 448.0 and 426.7 MPa for the square and sinusoidal pulses, respectively. On the other hand, the electric pulses improved the formability of the AA2024 alloy owing to the activation of more slip systems, inhibition of dislocation pinning, the promotion of dislocation movement, and the acceleration of restoration mechanisms.

scholarly journals Daily behaviour of Hungarian Grey Cattle under range grazing conditions

2013 ◽  
pp. 45-48
Author(s):  
András Halász ◽  
Géza Nagy
Keyword(s):  
Cost Effective ◽  
Water Source ◽  
Pressure Change ◽  
Air Pressure ◽  
Air Masses ◽  
Behavioural Characteristics ◽  
Cattle Herds ◽  
Cost Efficient ◽  
Pressure Changes ◽  
Daily Distance

Cattle behaviour on rangeland depends on external factors, such as grass allowance and quality, temperature, net solar radiation, distance from water-source, wind speed and direction, air pressure changes and the applied breeding technology. Our research is based on previous empirical observations and modern methods to analyze the behaviour of the Hungarian Grey Cattle. Today it is crucial to use cost-effective solutions in modern beef cattle farming therefore we introduce a cost-efficient method to study and follow cattle herds. We are studying relation between traveled daily distance and air pressure. The various weather fronts influence behavioural characteristics and traveled daily distance. According to our hypothesis, the pressure-change and the wind direction has significant effect on cattle activity on pasture. As the different air masses alter the barometric conditions and unbalance the neuroendocrine system, indirectly cause relaxed or agitated behaviour

Atmospheric pressure compared to rainfall as landslide triggering factors along a hillslope

2021 ◽  
Author(s):  
Lucas Pelascini ◽  
Philippe Steer ◽  
Laurent Longuevergne
Keyword(s):  
Slope Stability ◽  
Pore Pressure ◽  
Water Table ◽  
Atmospheric Pressure ◽  
Pressure Change ◽  
Unconfined Aquifer ◽  
Air Pressure ◽  
Water Infiltration ◽  
Landslide Occurrence ◽  
Pressure Changes

<p>Landslides are one of the sources of natural hazards that cause damages and losses but also shapes the landscape. A better understanding the factors triggering or pre-conditioning landslide occurrence is therefore critical for risk assessment, with implications for hillslope erosion and landscape dynamics Triggering of catastrophic landslides is generally associated with events such as earthquakes or intense rainfalls. In Taiwan, a minimum of 22,705 landslides were reported during the typhoon Morakot in 2009 (Lin et al., 2011). Landslides triggered during storms are generally associated to the intensity and cumulated amount of rainfall, as water infiltration destabilize slopes (Iverson, 2000). However, a correlation has also been reported between slope stability and the change in atmospheric pressure (Schulz, 2009). Indeed, a change in air-pressure can lead in a readjustment in pore pressure, and cause fluid movements normal to the surface. The aim of this study is to characterize the effect of atmospheric pressure changes and define its specific contribution on slope stability when combined with rainfall</p><p>A 2-dimensional analytical model has been developed based on diffusion equations to describe the destabilization induced by water infiltration and atmospheric pressure changes induced by typhoons. As both mechanisms are function of pore pressure, and especially groundwater pore pressure, the water table within a finite-length hillslope is modelled using Townley’s (1995) analytical expression of water flow in a unconfined aquifer. The hillslope itself is a simple tilted half-space with a water divide at the top and a river at the toe forcing the water table to the surface. Slope stability is inferred through a safety factor computed using the coulomb criterion. Both rainfall infiltration and air pressure modify pore pressure through a diffusion process. While rainfall increases water table height and induce large increases in pore pressure within days or hours, , we show that atmospheric-induced pore pressure change is instantaneous and can occur even if the hillslope is fully saturated.</p><p>The model allows to separate the hillslope response into two regimes, upslope or downslope, where the destabilization is mainly linked to rainfall or to atmospheric pressure change, respectively.  Our results suggest that landslide occurring during storms in the downstream part of the hillslope are likely candidate for being triggered by atmospheric pressure change, in particular if the storm occurs with a humid initial condition. We show that the effect of atmospheric pressure changes is not negligible. On contrary, it is crucial to define the amplitude, timing and geometry of the hillslope instability, especially when combined to rainfall.</p>

scholarly journals Numerical Modeling and Experimental Verification for High-Speed Forming of Al5052 with Single Current Pulse

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1311
Author(s):  
Hyeong-Gyu Park ◽  
Beom-Soo Kang ◽  
Jeong Kim
Keyword(s):  
Mechanical Behavior ◽  
Thermal Effect ◽  
Electric Current ◽  
Current Pulse ◽  
High Speed ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Electric Current Pulse ◽  
Current Pulses ◽  
Electric Current Pulses

Application of electric current pulses during plastic deformation changes the mechanical behavior owing to the electro-plastic effect. The effect of electric current pulses on the Al5052 alloy is investigated in this study. In order to demonstrate the advantages of passing electric current pulses through a metal sheet during the forming process, a uniaxial tensile test with an electric current pulse was carried out using a self-designed device; this device can apply a 2-kA electric current pulse to the specimen for a short period (>100ms). The electric current increases the temperature of the specimen due to Joule heating. It is, therefore, necessary to decouple the thermal effect from the overall behavior to understand only the contribution of electric current in the mechanical behavior. Firstly, an electro-thermo-mechanical finite element study of an electrically assisted uniaxial tensile test of Al5052 alloy is performed to isolate the thermal effect. The simulated results yielded the thermal effect due to the electric current. By comparing the experimental and simulated results, the contribution of electric current is decoupled from that of thermal effect. The electric current-dependent material model is implemented into the commercial FEM code LS-DYNA using user-defined material(UMAT) subroutine. The electric current-dependent material model was used to simulate the electro-mechanical finite element analysis of the high-speed forming of an aluminum sheet with electric current pulse. Simulation results were compared with experimental results at several applied electric currents to evaluate the accuracy of the UMAT. The present work can be utilized to develop simpler constitutive models for the mechanical behavior of metals subjected to a pulsed electric current.

Heart Rate Signal Decomposition

2000 ◽  
Vol 39 (02) ◽  
pp. 200-203
Author(s):  
H. Mizuta ◽  
K. Yana
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressure Change ◽  
Normal Subjects ◽  
Signal Decomposition ◽  
Large Individual ◽  
Heart Rate Fluctuations ◽  
Type Pattern ◽  
Signal Cancellation ◽  
Pressure Changes

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.

scholarly journals Research on HAR-Based Floor Positioning

2021 ◽  
Vol 10 (7) ◽  
pp. 437
Author(s):  
Hongxia Qi ◽  
Yunjia Wang ◽  
Jingxue Bi ◽  
Hongji Cao ◽  
Shenglei Xu
Keyword(s):  
Barometric Pressure ◽  
Air Pressure ◽  
Location Based Services ◽  
Sensor Data ◽  
Reference Station ◽  
Position Change ◽  
Radio Signals ◽  
Positioning Method ◽  
Pressure Changes

Floor positioning is an important aspect of indoor positioning technology, which is closely related to location-based services (LBSs). Currently, floor positioning technologies are mainly based on radio signals and barometric pressure. The former are impacted by the multipath effect, rely on infrastructure support, and are limited by different spatial structures. For the latter, the air pressure changes with the temperature and humidity, the deployment cost of the reference station is high, and different terminal models need to be calibrated in advance. In view of these issues, here, we propose a novel floor positioning method based on human activity recognition (HAR), using smartphone built-in sensor data to classify pedestrian activities. We obtain the degree of the floor change according to the activity category of every step and determine whether the pedestrian completes floor switching through condition and threshold analysis. Then, we combine the previous floor or the high-precision initial floor with the floor change degree to calculate the pedestrians’ real-time floor position. A multi-floor office building was chosen as the experimental site and verified through the process of alternating multiple types of activities. The results show that the pedestrian floor position change recognition and location accuracy of this method were as high as 100%, and that this method has good robustness and high universality. It is more stable than methods based on wireless signals. Compared with one existing HAR-based method and air pressure, the method in this paper allows pedestrians to undertake long-term static or round-trip activities during the process of going up and down the stairs. In addition, the proposed method has good fault tolerance for the misjudgment of pedestrian actions.

Refinement of inclusions in molten steel by electric current pulse

2015 ◽  
Vol 31 (13) ◽  
pp. 1555-1559 ◽  
Author(s):  
W. B. Dai ◽  
J. K. Yu ◽  
C. M. Du ◽  
L. Zhang ◽  
X. L. Wang
Keyword(s):  
Electric Current ◽  
Current Pulse ◽  
Molten Steel ◽  
Electric Current Pulse

Electric Current Pulse Welding of Titanium with 18-10 Stainless Steel

2009 ◽  
Vol 83-86 ◽  
pp. 1251-1253 ◽  
Author(s):  
E.G. Grigoryev ◽  
V.N. Bazanov
Keyword(s):  
Stainless Steel ◽  
Electric Current ◽  
Current Pulse ◽  
Contact Zone ◽  
Welded Joints ◽  
High Speed ◽  
Welded Joint ◽  
Electric Current Pulse ◽  
Pulse Effect ◽  
Different Thickness

The purpose of the work was to determine the capabilities of the pulse effect of electric current and pressure to produce welded joints of various component parts of different thickness from 18-10 stainless steel and titanium. Application of electric current pulses on the surfaces of contacting metallic conductors leads to considerable changes in the surface structure. Depending on the initial state of the surfaces and parameters of the pulse effect this can result in melting without formation of joints, formation of a strong welded joint with characteristics no worse than those of welded metals, and in destruction of the contact zone. A combination of a short electric pulse with simultaneous application of mechanical pressure in the weld zone causes high-speed deformation of the contact zone. The process of joint formation itself does not cause any appreciable diffusion during welding. The greatest energy emission and the maximal heating occur on the contacting surfaces being welded with the passage of an electric current pulse through the welding zone. Simultaneously with intensive heating, and due to applied pressure, high-speed deformation of materials takes place and a strong welded joint is formed. Optimal parameters for the welding of titanium and 18-10 stainless steel have been determined on the basis of the tests conducted. Investigations into the welding of titanium and 18-10 stainless steel have shown that application of a short electric current pulse and pressure produces stronger welded joints composed of both similar and different metals of considerably different thickness.

Study of Toynbee Phenomenon by Combined Intranasopharyngeal and Tympanometric Measurements

1988 ◽  
Vol 97 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Yehuda Finkelstein ◽  
Yuval Zohar ◽  
Yoav P. Talmi ◽  
Nelu Laurian
Keyword(s):  
Middle Ear ◽  
Negative Pressure ◽  
Pressure Change ◽  
Positive Pressure ◽  
New Information ◽  
Pressure Changes ◽  
Rapid Pressure

The Toynbee maneuver, swallowing when the nose is obstructed, leads in most cases to pressure changes in one or both middle ears, resulting in a sensation of fullness. Since first described, many varying and contradictory comments have been reported in the literature concerning the type and amount of pressure changes both in the nasopharynx and in the middle ear. In our study, the pressure changes were determined by catheters placed into the nasopharynx and repeated tympanometric measurements. New information concerning the rapid pressure variations in the nasopharynx and middle ear during deglutition with an obstructed nose was obtained. Typical individual nasopharyngeal pressure change patterns were recorded, ranging from a maximal positive pressure of + 450 to a negative pressure as low as −320 mm H2O.

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