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Journal articles on the topic 'Oscillating modulation of the pressure'

Author: Grafiati

Published: 30 May 2022

Last updated: 31 July 2025

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1

Staubli, Thomas, and Donald Rockwell. "Pressure fluctuations on an oscillating trailing edge." Journal of Fluid Mechanics 203 (June 1989): 307–46. http://dx.doi.org/10.1017/s0022112089001485.

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Turbulent boundary layers separating from a blunt trailing edge give rise to organized vortical structures in the downstream wake. The perturbation of this inherent flow-instability at f0 by controlled oscillations of the edge at fe produces corresponding, organized components of unsteady surface pressure along the edge. For edge excitation near the ‘natural’ vortex shedding frequency f0, the phase between the local pressure fluctuations and the edge displacement shows large changes for small changes in excitation frequency. Moreover, in this range of excitation, there is quenching (or attenua

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2

Marsh, Donald J., Olga V. Sosnovtseva, Alexey N. Pavlov, Kay-Pong Yip, and Niels-Henrik Holstein-Rathlou. "Frequency encoding in renal blood flow regulation." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 288, no. 5 (2005): R1160—R1167. http://dx.doi.org/10.1152/ajpregu.00540.2004.

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With a model of renal blood flow regulation, we examined consequences of tubuloglomerular feedback (TGF) coupling to the myogenic mechanism via voltage-gated Ca channels. The model reproduces the characteristic oscillations of the two mechanisms and predicts frequency and amplitude modulation of the myogenic oscillation by TGF. Analysis by wavelet transforms of single-nephron blood flow confirms that both amplitude and frequency of the myogenic oscillation are modulated by TGF. We developed a double-wavelet transform technique to estimate modulation frequency. Median value of the ratio of modu

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3

Мартынец, Татьяна Викторовна. "Experimental research of oscillating modulation of pressure in hydraulic brake drive." Eastern-European Journal of Enterprise Technologies 2, no. 10(56) (2012): 46–49. http://dx.doi.org/10.15587/1729-4061.2012.3893.

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4

Teixeira, Luis Augusto, Joane de Figueiredo Serpa Coutinho, and Daniel Boari Coelho. "Regulation of dynamic postural control to attend manual steadiness constraints." Journal of Neurophysiology 120, no. 2 (2018): 693–702. http://dx.doi.org/10.1152/jn.00941.2017.

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In daily living activities, performance of spatially accurate manual movements in upright stance depends on postural stability. In the present investigation, we aimed to evaluate the effect of the required manual steadiness (task constraint) on the regulation of dynamic postural control. A single group of young participants ( n = 20) were evaluated in the performance of a dual posturo-manual task of balancing on a platform oscillating in sinusoidal translations at 0.4-Hz (low) or 1-Hz (high) frequencies while stabilizing a cylinder on a handheld tray. Manual task constraint was manipulated by

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5

Han, Tian, Guanshi Wang, Changchun Dong, Xiaolin Jiang, Mingyuan Ren, and Zhu Zhang. "A Self-Oscillating Driving Circuit for Low-Q MEMS Vibratory Gyroscopes." Micromachines 14, no. 5 (2023): 1057. http://dx.doi.org/10.3390/mi14051057.

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This article establishes a circuit model with which to analyze the difficulty of auto-gain control driving for low-Q micromechanical gyroscopes at room temperature and normal pressure. It also proposes a driving circuit based on frequency modulation to eliminate the same-frequency coupling between the drive signal and displacement signal using a second harmonic demodulation circuit. The results of the simulation indicate that a closed-loop driving circuit system based on the frequency modulation principle can be established within 200 ms with a stable average frequency of 4504 Hz and a frequen

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6

Horsman, H. M., K. C. Peebles, and Y. C. Tzeng. "Interactions between breathing rate and low-frequency fluctuations in blood pressure and cardiac intervals." Journal of Applied Physiology 119, no. 7 (2015): 793–98. http://dx.doi.org/10.1152/japplphysiol.00525.2015.

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Evidence derived from spontaneous measures of cardiovagal baroreflex sensitivity (BRS) suggests that slow breathing at 6 breaths/min augments BRS. However, increases in BRS associated with slow breathing may simply reflect the frequency-dependent nature of the baroreflex rather than the modulation of baroreflex function by changes in breathing rate per se. To test this hypothesis we employed a crossover study design ( n = 14) wherein breathing rate and systolic arterial blood pressure (SAP) oscillation induced via the application of oscillating lower body negative pressure (OLBNP) were indepen

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7

Kalashnik, M. V., and S. N. Kulichkov. "On pressure perturbations caused by a moving heat source of the frontal type (hydrostatic mode)." Известия Российской академии наук. Физика атмосферы и океана 55, no. 5 (2019): 51–61. http://dx.doi.org/10.31857/s0002-351555551-61.

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The problem of perturbations of the surface pressure caused by a moving nonstationary frontal heat source (localized along one horizontal coordinate) is considered. Pressure disturbances are associated with internal gravity waves (IGWs). It is shown that when a source moves in a finite-height atmospheric layer (atmospheric waveguide) when a discrete set of vertical IGW modes is excited, there are three types of temporal variation of surface pressure at a fixed observation point. These types correspond respectively to the time signal with amplitude modulation, the signal with frequency modulate

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8

Lester, Rosemary A., and Brad H. Story. "Acoustic Characteristics of Simulated Respiratory-Induced Vocal Tremor." American Journal of Speech-Language Pathology 22, no. 2 (2013): 205–11. http://dx.doi.org/10.1044/1058-0360(2012/12-0043).

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Purpose The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor. Method Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F 0 ) for speech samples obtained by Farinella, Hixon, Hoit, Story, and Jones (2006) using a respiratory forced oscillation paradigm with 5 healthy adult males to simulate vocal tremor involving respiratory pressure modulation. The analyzed conditions were sustained productions of /a/ with amplitudes of applied pressure of 0, 1, 2

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9

Chen, C. K., L. Wang, J. T. Yang, and L. T. Chen. "Experimental and Computational Analysis of Periodic Flow Structure in Oscillatory Gas Flow Meters." Journal of Mechanics 22, no. 2 (2006): 137–44. http://dx.doi.org/10.1017/s1727719100004433.

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AbstractThe oscillatory characteristics and dynamic structure of periodic flow in an oscillatory gas flow meter were studied experimentally and numerically. The flow oscillations were triggered by the Coanda effect and an universal correlation between Strouhal number and Reynolds number, Str = 1.09 × 10−3 for ReHD >800, was deduced based on spectral analysis of the pressure fluctuations in the flow channel. Numerical simulation indicated that the evolution of the flow patterns was classified into stages of induction and sustainable periodic oscillation. The transformation between the two st

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10

Amador, Ana, Franz Goller, and Gabriel B. Mindlin. "Frequency Modulation During Song in a Suboscine Does Not Require Vocal Muscles." Journal of Neurophysiology 99, no. 5 (2008): 2383–89. http://dx.doi.org/10.1152/jn.01002.2007.

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The physiology of sound production in suboscines is poorly investigated. Suboscines are thought to develop song innately unlike the closely related oscines. Comparing phonatory mechanisms might therefore provide interesting insight into the evolution of vocal learning. Here we investigate sound production and control of sound frequency in the Great Kiskadee ( Pitangus sulfuratus) by recording air sac pressure and vocalizations during spontaneously generated song. In all the songs and calls recorded, the modulations of the fundamental frequency are highly correlated to air sac pressure. To test

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11

Grisk, Olaf, and Harald M. Stauss. "Frequency modulation of mesenteric and renal vascular resistance." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 282, no. 5 (2002): R1468—R1476. http://dx.doi.org/10.1152/ajpregu.00307.2001.

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The hypothesis was tested that low-frequency vasomotions in individual vascular beds are integrated by the cardiovascular system, such that new fluctuations at additional frequencies occur in arterial blood pressure. In anesthetized rats ( n = 8), the sympathetic splanchnic and renal nerves were simultaneously stimulated at combinations of frequencies ranging from 0.075 to 0.8 Hz. Blood pressure was recorded together with mesenteric and renal blood flow velocities. Dual nerve stimulation at low frequencies (<0.6 Hz) caused corresponding oscillations in vascular resistance and blood pressure

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12

Siu, K. L., B. Sung, W. A. Cupples, L. C. Moore, and K. H. Chon. "Detection of low-frequency oscillations in renal blood flow." American Journal of Physiology-Renal Physiology 297, no. 1 (2009): F155—F162. http://dx.doi.org/10.1152/ajprenal.00114.2009.

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Detection of the low-frequency (LF; ∼0.01 Hz) component of renal blood flow, which is theorized to reflect the action of a third renal autoregulatory mechanism, has been difficult due to its slow dynamics. In this work, we used three different experimental approaches to detect the presence of the LF component of renal autoregulation using normotensive and spontaneously hypertensive rats (SHR), both anesthetized and unanesthetized. The first experimental approach utilized a blood pressure forcing in the form of a chirp, an oscillating perturbation with linearly increasing frequency, to elicit r

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13

Thomas, Christian, Andrew P. Bassom, P. J. Blennerhassett, and Christopher Davies. "The linear stability of oscillatory Poiseuille flow in channels and pipes." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 467, no. 2133 (2011): 2643–62. http://dx.doi.org/10.1098/rspa.2010.0468.

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The linear stability of confined, periodic, parallel fluid flows is examined. The flow fields considered consist of a steady pressure gradient-driven velocity field combined with a purely oscillatory component generated by either an oscillatory pressure gradient or by harmonically oscillating bounding surfaces. Plane channel and circular pipe geometries are studied and all possible combinations of the steady and oscillatory flow components investigated. Neutral stability curves and critical conditions for instability are computed for a selection of steady–unsteady velocity ratios, channel half

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14

Auer, M. P., C. Gebauer, K. G. Mösl, C. Hirsch, and T. Sattelmayer. "Active Instability Control: Feedback of Combustion Instabilities on the Injection of Gaseous Fuel." Journal of Engineering for Gas Turbines and Power 127, no. 4 (2004): 748–54. http://dx.doi.org/10.1115/1.1924718.

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Modern low-emission premix combustion systems are often susceptible to combustion instabilities. Active instability control (AIC) systems are commonly used to attenuate these oscillations. For the control authority of AIC systems the effective amplitude and phase of the fuel modulation at the fuel outlet are as critical as the proper injection position. In typical cases the modulation of the fuel at the location of the actuator can be fundamentally different in amplitude and phase from the modulation of the fuel flow at the fuel outlet. In addition to the well-known effects stemming from the a

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15

Xu, Xiang, Chen Zhou, Run Shi, Binbin Ni, Zhengyu Zhao, and Yuannong Zhang. "Numerical study of the generation and propagation of ultralow-frequency waves by artificial ionospheric F region modulation at different latitudes." Annales Geophysicae 34, no. 9 (2016): 815–29. http://dx.doi.org/10.5194/angeo-34-815-2016.

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Abstract. Powerful high-frequency (HF) radio waves can be used to efficiently modify the upper-ionospheric plasmas of the F region. The pressure gradient induced by modulated electron heating at ultralow-frequency (ULF) drives a local oscillating diamagnetic ring current source perpendicular to the ambient magnetic field, which can act as an antenna radiating ULF waves. In this paper, utilizing the HF heating model and the model of ULF wave generation and propagation, we investigate the effects of both the background ionospheric profiles at different latitudes in the daytime and nighttime iono

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16

Broten, T. P., and J. E. Zehr. "Autonomic modulation of ultradian blood pressure and heart rate oscillations in dogs." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 256, no. 5 (1989): R1127—R1137. http://dx.doi.org/10.1152/ajpregu.1989.256.5.r1127.

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Autonomic receptor modulation of ultradian oscillations of blood pressure and heart rate was studied in telemetered free-running dogs. Data, analyzed for their harmonic content by fast Fourier transform (FFT) methods, indicated that ultradian and circadian oscillations of 22.9 +/- 2.5 and 10.5 +/- 0.9 (SD) mmHg, respectively, were present. The average principal frequency for the ultradian oscillations in 12 dogs was 0.760 +/- 0.11 cycles/h for arterial pressure and 0.808 +/- 0.10 for heart rate. Atropine had no effect on periodicity of either arterial pressure or heart rate. Metoprolol, a beta

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17

Schmidt, J. A., P. Borgstrom, and M. Intaglietta. "Neurogenic modulation of periodic hemodynamics in rabbit skeletal muscle." Journal of Applied Physiology 75, no. 3 (1993): 1216–21. http://dx.doi.org/10.1152/jappl.1993.75.3.1216.

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We characterized the effect of various forms of neural blockade and vasopressin infusion on regular slow-wave flux oscillation (RSWFO). RSWFO, measured with laser-Doppler flowmetry (LDF), was induced by local reduction of arterial pressure in the gastrocnemius muscle of 30 New Zealand White rabbits. At normal median femoral arterial mean pressure, LDF only showed irregular variations. With an intact innervation, RSWFO was maximal at a median femoral mean pressure of 30 mmHg (range 25–53), the median frequency was 1.7 cycles/min (range 1.0–3.0), and the maximum amplitude was 50% (range 19–119).

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18

Marsh, Donald J., Olga V. Sosnovtseva, Ki H. Chon, and Niels-Henrik Holstein-Rathlou. "Nonlinear interactions in renal blood flow regulation." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 288, no. 5 (2005): R1143—R1159. http://dx.doi.org/10.1152/ajpregu.00539.2004.

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We have developed a model of tubuloglomerular feedback (TGF) and the myogenic mechanism in afferent arterioles to understand how the two mechanisms are coupled. This paper presents the model. The tubular model predicts pressure, flow, and NaCl concentration as functions of time and tubular length in a compliant tubule that reabsorbs NaCl and water; boundary conditions are glomerular filtration rate (GFR), a nonlinear outflow resistance, and initial NaCl concentration. The glomerular model calculates GFR from a change in protein concentration using estimates of capillary hydrostatic pressure, t

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19

Badra, Leslie J., William H. Cooke, Jeffrey B. Hoag, et al. "Respiratory modulation of human autonomic rhythms." American Journal of Physiology-Heart and Circulatory Physiology 280, no. 6 (2001): H2674—H2688. http://dx.doi.org/10.1152/ajpheart.2001.280.6.h2674.

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We studied the influence of three types of breathing [spontaneous, frequency controlled (0.25 Hz), and hyperventilation with 100% oxygen] and apnea on R-R interval, photoplethysmographic arterial pressure, and muscle sympathetic rhythms in nine healthy young adults. We integrated fast Fourier transform power spectra over low (0.05–0.15 Hz) and respiratory (0.15–0.3 Hz) frequencies; estimated vagal baroreceptor-cardiac reflex gain at low frequencies with cross-spectral techniques; and used partial coherence analysis to remove the influence of breathing from the R-R interval, systolic pressure,

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20

Leung, C. G., and P. Mason. "Spectral analysis of arterial blood pressure and raphe magnus neuronal activity in anesthetized rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 271, no. 2 (1996): R483—R489. http://dx.doi.org/10.1152/ajpregu.1996.271.2.r483.

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Recent evidence suggests that nociceptive modulatory cells in the nucleus raphe magnus (RM) and adjacent nucleus reticularis magnocellularis (NRMC) may participate in the modulation of autonomic processing. Therefore, spectral analyses were used to determine component frequencies common to both arterial blood pressure and the activity of RM/NRMC neurons in rats lightly anesthetized with isoflurane. These analyses detected powerful, extremely low frequency (period length: 6.4-18.5 min) oscillations in arterial blood pressure and in the activity of two classes of RM/NRMC neurons, ON and OFF cell

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21

Rossi, Denise Martineli, Hugo Celso Dutra de Souza, Débora Bevilaqua-Grossi, et al. "Impairment on Cardiovascular Autonomic Modulation in Women with Migraine." International Journal of Environmental Research and Public Health 20, no. 1 (2022): 763. http://dx.doi.org/10.3390/ijerph20010763.

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Autonomic dysfunction, such as reduced vagally mediated heart rate variability, has been suggested in headache patients but is still uncertain when considering primary headache disorders. This study aims to compare the heart rate and blood pressure variability and baroreflex sensitivity between women with migraine and controls. A migraine (n = 20) and a control group (n = 20) of age-matched women without headache were evaluated. Heart rate variability was analyzed through frequency-domain using spectral analysis presenting variance, low-frequency (LF; 0.04–0.15 Hz) and high-frequency (HF; 0.15

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22

Yoden, Shigeo, Vinay Kumar, Surendra Dhaka, and Matthew Hitchman. "Global monsoon systems and their modulation by the equatorial Quasi-Biennial Oscillation." MAUSAM 74, no. 2 (2023): 239–52. http://dx.doi.org/10.54302/mausam.v74i2.5948.

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Monthly-mean data of ERA-Interim reanalysis, precipitation, outgoing longwave radiation (OLR) and sea surface temperature(SST) are investigated for 40 years (1979-2018) to reveal the modulation of the global monsoon systems by the equatorial quasi-biennial oscillation (QBO), focusing only on the neutral El Niño-Southern Oscillation (ENSO) periods (in total 374 months). First, the climatology of the global monsoon systems is viewed with longitude-latitude plots of the precipitation, its proxies and lower tropospheric circulations for the annual mean and two solstice seasons, together with the c

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23

Brady, Ken M., R. Blaine Easley, Kathleen Kibler, et al. "Positive end-expiratory pressure oscillation facilitates brain vascular reactivity monitoring." Journal of Applied Physiology 113, no. 9 (2012): 1362–68. http://dx.doi.org/10.1152/japplphysiol.00853.2012.

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The pressure reactivity index (PRx) identifies optimal cerebral perfusion pressure after traumatic brain injury. We describe a method to improve PRx precision by induced variations in arterial blood pressure (ABP) using positive end-expiratory pressure (PEEP) modulation ( iPRx). Neonatal swine ( n = 10) were ventilated with static PEEP and then with PEEP oscillated between 5 and 10 cmH2O at a frequency of 1/min. PRx was recorded as a moving correlation coefficient between ABP and intracranial pressure (ICP) from spontaneous ABP activity (0.05-0.003 Hz) during static PEEP. iPRx was similarly re

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24

He, Shengping, and Huijun Wang. "Oscillating Relationship between the East Asian Winter Monsoon and ENSO." Journal of Climate 26, no. 24 (2013): 9819–38. http://dx.doi.org/10.1175/jcli-d-13-00174.1.

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Abstract This work investigates the interdecadal variations of the relationship between the El Niño–Southern Oscillation (ENSO) and the East Asian winter monsoon (EAWM), further explores possible mechanisms, and finally considers a recent switch in the ENSO–EAWM relationship. The 23-yr sliding correlation between the Niño-3.4 index and the EAWM index reveals an obvious low-frequency oscillation with a period of about 50 yr in the ENSO–EAWM relationship. Warm ENSO events during high-correlation periods are associated with an unusually weak East Asian trough, a positive phase of the North Pacifi

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Passino, C., P. Sleight, F. Valle, G. Spadacini, S. Leuzzi, and L. Bernardi. "Lack of peripheral modulation of cardiovascular central oscillatory autonomic activity during apnea in humans." American Journal of Physiology-Heart and Circulatory Physiology 272, no. 1 (1997): H123—H129. http://dx.doi.org/10.1152/ajpheart.1997.272.1.h123.

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Respiratory sinus arrhythmia (RSA) high-frequency oscillations (HF) and slow fluctuations in heart rate (LF) are thought to result from entrainment of a medullary oscillator, from the baroreflex, or from a combination of both central and baroreflex mechanisms. We sought to distinguish between the alternatives by examining with spectral analysis the behavior of heart rate (R-R interval) and blood pressure in 10 healthy subjects (mean age 27 +/- 1 yr) during apnea, altering the rate of preapnea entrainment stimuli by changing the frequency either of respiration (controlled at 0.1 or 0.25 Hz) or

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26

Mohan, Balasundaram, and Sathesh Mariappan. "Nonlinear characterization of azimuthal combustion instability exhibiting flame transient phenomena." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 5 (2023): 2625–32. http://dx.doi.org/10.3397/in_2022_0368.

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This article characterizes the nonlinear features observed in an annular combustor exhibiting self-excited azimuthal thermoacoustic instability. The annular combustor consists of 12 burners with flames stabilized by bluff bodies protruding into the combustion chamber. This burner configuration closely resembles the flame stabilization geometry and flame shape in ramjet and afterburners configurations. As a first step, two different bluff bodies stabilize the flame: 1) circular and 2) conical and associated instability dynamics are characterized. The combustor exhibits intermittent oscillation

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27

Nomoto, T., T. Maruyama, S. Yamashita, H. Akutsu, and Y. Nakazawa. "Development of frequency tuning AC modulation method for high-pressure heat capacity measurements of molecules-based compounds." Modern Physics Letters B 34, no. 19n20 (2020): 2040062. http://dx.doi.org/10.1142/s021798492040062x.

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The automatic frequency tuning method in the high-pressure ac calorimetry system constructed to measure heat capacity for molecules-based compounds with CuBe[Formula: see text]+[Formula: see text]NiCrAl cramp-type pressure cell is reported. This development is performed for increasing resolution and temperature ranges of the heat capacity measurements under external pressure up to 2.0 GPa. The system can check the appropriate conditions by tracing frequency dependence of [Formula: see text] to determine the oscillation frequency at the center of the plateau region of this value. The experiment

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28

Cui, Lihua, Fei Ma, and Tengfei Cai. "Investigation of Pressure Oscillation and Cavitation Characteristics for Submerged Self-Resonating Waterjet." Applied Sciences 11, no. 15 (2021): 6972. http://dx.doi.org/10.3390/app11156972.

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The cavitation phenomenon of the self-resonating waterjet for the modulation of erosion characteristics is investigated in this paper. A three-dimensional computational fluid dynamics (CFD) model was developed to analyze the unsteady characteristics of the self-resonating jet. The numerical model employs the mixture two-phase model, coupling the realizable turbulence model and Schnerr–Sauer cavitation model. Collected data from experimental tests were used to validate the model. Results of numerical simulations and experimental data frequency bands obtained by the Fast Fourier transform (FFT)

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Warner, M. R., J. M. deTarnowsky, C. C. Whitson, and J. M. Loeb. "Beat-by-beat modulation of AV conduction. II. Autonomic neural mechanisms." American Journal of Physiology-Heart and Circulatory Physiology 251, no. 6 (1986): H1134—H1142. http://dx.doi.org/10.1152/ajpheart.1986.251.6.h1134.

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We examined the mechanism by which autonomic neural activity associated with respiration and blood pressure modulates atrioventricular (AV) conduction in conscious dogs. Mongrel dogs were anesthetized and instrumented under sterile conditions to record atrial and ventricular electrograms and blood pressure. In the conscious state, electrocardiogram (ECG), respiration, blood pressure, and electrograms were recorded continuously, and heart rate and AV interval were plotted graphically as a function of time. To delineate the role(s) of sympathetic and parasympathetic activity, AV conduction was s

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Wei, Ning, and Anita T. Layton. "Theoretical assessment of the Ca2+ oscillations in the afferent arteriole smooth muscle cell of the rat kidney." International Journal of Biomathematics 11, no. 03 (2018): 1850043. http://dx.doi.org/10.1142/s1793524518500432.

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The afferent arteriole (AA) of rat kidney exhibits the myogenic response, in which the vessel constricts in response to an elevation in blood pressure and dilates in response to a pressure reduction. Additionally, the AA exhibits spontaneous oscillations in vascular tone at physiological luminal pressures. These time-periodic oscillations stem from the dynamic exchange of Ca[Formula: see text] between the cytosol and the sarcoplasmic reticulum, coupled to the stimulation of Ca[Formula: see text]-activated potassium and chloride channels, and to the modulation of voltage-gated L-type Ca[Formula

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Barnett, William H., Elizaveta M. Latash, Robert A. Capps, Thomas E. Dick, Erica A. Wehrwein, and Yaroslav I. Molkov. "Traube–Hering waves are formed by interaction of respiratory sinus arrhythmia and pulse pressure modulation in healthy men." Journal of Applied Physiology 129, no. 5 (2020): 1193–202. http://dx.doi.org/10.1152/japplphysiol.00452.2020.

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Variability in blood pressure has become an important metric to consider as more is learned about the link between excessive blood pressure variability and adverse health outcomes. In this study using slow deep breathing in human subjects, we found that heart rate and pulse pressure variations have comparable effects on the amplitude of blood pressure waves, and it is the common action of the two that defines the phase relationship between respiration and blood pressure oscillations.

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Kahr, Matthias, Michael Stifter, Harald Steiner, et al. "Dual Resonator MEMS Magnetic Field Gradiometer." Sensors 19, no. 3 (2019): 493. http://dx.doi.org/10.3390/s19030493.

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Accurate knowledge of the spatial magnetic field distribution is necessary when measuring field gradients. Therefore, a MEMS magnetic field gradiometer is reported, consisting of two identical, but independent laterally oscillating masses on a single chip. The sensor is actuated by Lorentz force and read out by modulation of the light flux passing through stationary and moving arrays of the chip. This optical readout decouples the transducer from the electronic components. Both phase and intensity are recorded which reveals information about the uniformity of the magnetic field. The magnetic f

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Gunst, S. J., J. Q. Stropp, and J. Service. "Mechanical modulation of pressure-volume characteristics of contracted canine airways in vitro." Journal of Applied Physiology 68, no. 5 (1990): 2223–29. http://dx.doi.org/10.1152/jappl.1990.68.5.2223.

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In normal humans and dogs, the airways do not constrict to closure even when maximally stimulated. However, airway closure can be produced in isolated canine lobes and bronchial segments that are stimulated with maximal concentrations of bronchoconstrictors. These observations suggest that under normal conditions, physiological mechanisms to limit bronchoconstriction exist in vivo. In this investigation, we evaluated how mechanical factors that influence airway smooth muscle contractility contribute to the modulation of the pressure-volume characteristics of contracted canine intraparenchymal

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Zhukov, V. I., and D. M. Karfidov. "Plasma Distribution in a Column of a Low-Pressure Microwave Discharge Sustained by a Standing Surface Wave." Физика плазмы 49, no. 8 (2023): 779–88. http://dx.doi.org/10.31857/s0367292123600462.

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The structure of a low-pressure microwave discharge sustained by a standing surface electromagnetic wave (SEW) in a quartz tube filled with argon was studied. The standing wave was formed using a set of two flat metal mirrors, which formed an open SEW resonator. The plasma density profile and structure of the electromagnetic field of the SEW were studied in the pressure range from 0.25 to 10 Torr. The excitation of the standing wave allowed us to independently study the longitudinal Ez and transverse Er components of the SEW electric field vector. It was confirmed experimentally that the oscil

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35

Meijlink, Bram, Ines Beekers, Simone A. G. Langeveld, et al. "The OrganoPlate^® as vessel-on-a-chip model to investigate increased microbubble-mediated vascular permeability." Journal of the Acoustical Society of America 151, no. 4 (2022): A174. http://dx.doi.org/10.1121/10.0011016.

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The vessel wall is an important barrier modulating drug delivery to the underlying diseased tissue. Oscillating microbubbles can be used to locally enhance vascular permeability and sonoporate cells. As the mechanism is not fully understood, our aim was to grow 3D human vessels-on-a-chip in the OrganoPlate® 40 and use this model to investigate the effect of αvβ3 -targeted microbubble and different ultrasound pressures (2 MHz, 100–850 kPa peak negative pressure) and cycle lengths (10×10 or 10×1000 cycles) on vascular permeability and sonoporation. The vascular permeability of 122 microvessels i

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Le Ray, Didier, Frédéric Brocard, and Réjean Dubuc. "Muscarinic Modulation of the Trigemino-Reticular Pathway in Lampreys." Journal of Neurophysiology 92, no. 2 (2004): 926–38. http://dx.doi.org/10.1152/jn.01025.2003.

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In lampreys, reticulospinal neurons integrate sensory inputs to adapt their control onto the spinal locomotor networks. Whether and how sensory inputs to reticulospinal neurons are modulated remains to be determined. We showed recently that cholinergic inputs onto reticulospinal neurons play a key role in the initiation of locomotion elicited by stimulation of the mesencephalic locomotor region in semi intact lampreys. Here, we examined the possible role of muscarinic acetylcholine receptors in modulating trigeminal inputs to reticulospinal neurons. A local application of muscarinic agonists o

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Zhang, Qingxin, Hooman Homayouni, Byron D. Gates, Michael H. Eikerling, and Amir M. Niroumand. "Electrochemical Pressure Impedance Spectroscopy for Polymer Electrolyte Fuel Cells via Back-Pressure Control." Journal of The Electrochemical Society 169, no. 4 (2022): 044510. http://dx.doi.org/10.1149/1945-7111/ac6326.

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Electrochemical pressure impedance spectroscopy (EPIS) analyses the voltage response of a polymer electrolyte fuel cell (PEFC) as a function of an applied pressure signal in the frequency domain. EPIS is similar to electrochemical impedance spectroscopy (EIS) and its development was inspired by the diagnostic capabilities of the latter. The EPIS introduced in this work modulates the cathode pressure of a PEFC with a sinusoidal signal through the use of a back-pressure controller, and monitors the cell voltage while holding the cell at a constant current. A sinusoidal pressure wave propagates a

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Hood, Lon L., Malori A. Redman, Wes L. Johnson, and Thomas J. Galarneau. "Stratospheric Influences on the MJO-Induced Rossby Wave Train: Effects on Intraseasonal Climate." Journal of Climate 33, no. 1 (2020): 365–89. http://dx.doi.org/10.1175/jcli-d-18-0811.1.

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AbstractThe tropical Madden–Julian oscillation (MJO) excites a northward propagating Rossby wave train that largely determines the extratropical surface weather consequences of the MJO. Previous work has demonstrated a significant influence of the tropospheric El Niño–Southern Oscillation (ENSO) on the characteristics of this wave train. Here, composite analyses of ERA-Interim sea level pressure (SLP) and surface air temperature (SAT) data during the extended northern winter season are performed to investigate the additional role of stratospheric forcings [the quasi-biennial oscillation (QBO)

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Wu, X. Z., Y. R. Shou, Z. B. Guo, et al. "Effects of electron heating and surface rippling on Rayleigh–Taylor instability in radiation pressure acceleration." Matter and Radiation at Extremes 8, no. 3 (2023): 036902. http://dx.doi.org/10.1063/5.0130513.

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The acceleration of ultrathin targets driven by intense laser pulses induces Rayleigh–Taylor-like instability. Apart from laser and target configurations, we find that electron heating and surface rippling, effects inherent to the interaction process, have an important role in instability evolution and growth. By employing a simple analytical model and two-dimensional particle-in-cell simulations, we show that the onset of electron heating in the early stage of the acceleration suppresses the growth of small-scale modes, but it has little influence on the growth of large-scale modes, which thu

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Warner, M. R., and J. M. Loeb. "Beat-by-beat modulation of AV conduction. I. Heart rate and respiratory influences." American Journal of Physiology-Heart and Circulatory Physiology 251, no. 6 (1986): H1126—H1133. http://dx.doi.org/10.1152/ajpheart.1986.251.6.h1126.

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We examined the integration of heart rate and neural influences at the atrioventricular (AV) node in conscious dogs. Animals were anesthetized and, under sterile conditions, instrumented to chronically record atrial and ventricular electrograms and blood pressure. In the conscious state, electrocardiogram (ECG), respiration, blood pressure, and electrograms were recorded on a beat-by-beat basis, and heart rate and AV interval were plotted graphically as a function of time. Resting animals exhibited both respiratory sinus arrhythmia and marked oscillations in AV conduction time associated with

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Schilden, Thomas, and Wolfgang Schröder. "Inclined slow acoustic waves incident to stagnation point probes in supersonic flow." Journal of Fluid Mechanics 866 (March 13, 2019): 567–97. http://dx.doi.org/10.1017/jfm.2019.121.

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Tunnel noise in supersonic testing facilities is known to be a decisive factor in boundary layer transition experiments. It defines initial conditions for the growth of modal instabilities by the receptivity mechanism. That is, to interpret experimental results, the determination of tunnel noise is of crucial importance. It is common to use stagnation point probes equipped with pressure transducers in supersonic flows, but since tunnel noise undergoes modulation during the measurement, the probes must be calibrated. The predominant component of tunnel noise is caused by the nozzle boundary lay

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Arregui, Guillermo, Martín F. Colombano, Jeremie Maire, et al. "Injection locking in an optomechanical coherent phonon source." Nanophotonics 10, no. 4 (2021): 1319–27. http://dx.doi.org/10.1515/nanoph-2020-0592.

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Abstract Spontaneous locking of the phase of a coherent phonon source to an external reference is demonstrated in a deeply sideband-unresolved optomechanical system. The high-amplitude mechanical oscillations are driven by the anharmonic modulation of the radiation pressure force that result from an absorption-mediated free-carrier/temperature limit cycle, i.e., self-pulsing. Synchronization is observed when the pump laser driving the mechanical oscillator to a self-sustained state is modulated by a radiofrequency tone. We employ a pump-probe phonon detection scheme based on an independent opt

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Kilifarska, Natalya, Antonia Mokreva, and Tsvetelina Velichkova. "North Atlantic Oscillation and Variations of Geomagnetic Field." Proceedings of the Bulgarian Academy of Sciences 75, no. 11 (2022): 1628–37. http://dx.doi.org/10.7546/crabs.2022.11.10.

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The North Atlantic Oscillation is one of the most influential climatic modes in the Northern Hemisphere. However, the mechanism(s) standing behind its wide spectra of variations is still unknown despite its numerous investigations. This paper presents evidence for a synchronization between secular variations of geomagnetic field intensity and NAO long-term variability. Analysis of the connectivity between geomagnetic secular variations and the sea-level pressure – point by point, in a grid with resolution 10 [deg] in latitude and longitude – reveals that the strength of their relation is uneve

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Stenkamp, Kerstin, J. Matias Palva, Marylka Uusisaari, et al. "Enhanced Temporal Stability of Cholinergic Hippocampal Gamma Oscillations Following Respiratory Alkalosis In Vitro." Journal of Neurophysiology 85, no. 5 (2001): 2063–69. http://dx.doi.org/10.1152/jn.2001.85.5.2063.

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The decrease in brain CO2 partial pressure (pCO2) that takes place both during voluntary and during pathological hyperventilation is known to induce gross alterations in cortical functions that lead to subjective sensations and altered states of consciousness. The mechanisms that mediate the effects of the decrease in pCO2 at the neuronal network level are largely unexplored. In the present work, the modulation of gamma oscillations by hypocapnia was studied in rat hippocampal slices. Field potential oscillations were induced by the cholinergic agonist carbachol under an N-methyl-D-aspartate (

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Delgado, Esmeralda Sofia Costa, Carlos Marques-Neves, Maria Isabel Sousa Rocha, José Paulo Pacheco Sales-Luís, and Luís Filipe Silva-Carvalho. "Modulation of Vasomotive Activity in Rabbit External Ophthalmic Artery by Neuropeptides." Journal of Ophthalmology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/498565.

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Purpose. To investigate the vasomotive activity upon the external ophthalmic artery of vasointestinal peptide (VIP) and neuropeptide Y (NPY) using a previously developed model.Methods. Isolated rabbit eyes (n=12) were perfusedin situwith tyrode through the external ophthalmic artery. Effects of intra-arterial injections of NPY 200 μg/ml (Group A;n=6) and VIP 200 μg/ml (Group B;n=6) on the recorded pressure were obtained. For statistical analysis, Student's pairedt-test and Fast Fourier Transform were used.Results. Spontaneous oscillations were observed before any drug administration in the 12

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Pokharel, Prashanta, and Michael Patrick Sama. "The Effect of Nozzle Body Volume on Pressure Dynamics in a PWM Sprayer System." Journal of the ASABE 65, no. 6 (2022): 1355–63. http://dx.doi.org/10.13031/ja.15301.

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HighlightsThe variability in damping ratio between different sized nozzle tips was reduced with an increase in nozzle body volume, indicating that the previous works using pressure-sensing manifolds in PWM systems may have underestimated the nozzle pressure fluctuations.Pressure sensors installed at the nozzle body and the manifolds tested exhibited a different damping ratio, suggesting a slight change in sensor location might yield different measurements of transient pressure characteristics.A minimally invasive instrumented pressure sensor at the nozzle body is needed to accurately measure n

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Morris, K. F., S. C. Nuding, L. S. Segers, et al. "Respiratory and Mayer wave-related discharge patterns of raphé and pontine neurons change with vagotomy." Journal of Applied Physiology 109, no. 1 (2010): 189–202. http://dx.doi.org/10.1152/japplphysiol.01324.2009.

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Previous models have attributed changes in respiratory modulation of pontine neurons after vagotomy to a loss of pulmonary stretch receptor “gating” of an efference copy of inspiratory drive. Recently, our group confirmed that pontine neurons change firing patterns and become more respiratory modulated after vagotomy, although average peak and mean firing rates of the sample did not increase (Dick et al., J Physiol 586: 4265–4282, 2008). Because raphé neurons are also elements of the brain stem respiratory network, we tested the hypotheses that after vagotomy raphé neurons have increased respi

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Choi, Suk Min, and Christian Bach. "Experimental Investigation of PWM Throttling in a 50-Newton-Class HTP Monopropellant Thruster: Analysis of Pressure Surges and Oscillations." Aerospace 12, no. 5 (2025): 418. https://doi.org/10.3390/aerospace12050418.

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High-test peroxide (HTP) monopropellant thrusters are being considered for spacecraft lander missions due to their simplicity and reduced toxicity compared to traditional propellants. Pulse-Width Modulation (PWM) throttling is a key technique for precise thrust control in such systems. However, PWM throttling can lead to pressure surges and oscillations in the propellant feed system, potentially compromising system reliability. This study investigates the influence of PWM parameters, specifically duty cycle and frequency, on pressure surges and oscillations in a 50-newton-class HTP monopropell

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Minerick, Adrienne Robyn, Hsueh-Chia Chang, Todd M. Hoagland, and Kenneth R. Olson. "Dynamic synchronization analysis of venous pressure-driven cardiac output in rainbow trout." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 285, no. 4 (2003): R889—R896. http://dx.doi.org/10.1152/ajpregu.00228.2003.

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Measurement of venous function in vivo is inherently difficult. In this study, we used the Hilbert transform to examine the dynamic relationships between venous pressure and cardiac output (CO) in rainbow trout whose blood volume was continuously increased and decreased by ramp infusion and withdrawal (I/W). The dorsal aorta and ductus Cuvier were cannulated percutaneously and connected to pressure transducers; a flow probe was placed around the ventral aorta. Whole blood from a donor was then I/W via the dorsal aortic cannula at a rate of 10% of the estimated blood volume per minute, and the

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Ge, Jingwen, Xiaojing Jia, and Hao Ma. "Pacific Decadal Oscillation Modulation on the Relationship between Moderate El Niño-Southern Oscillation and East Asian Winter Temperature." Atmosphere 15, no. 2 (2024): 228. http://dx.doi.org/10.3390/atmos15020228.

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Based on observation data from 1958 to 2020, the current study explores the interdecadal modulation effects on moderate El Niño-Southern Oscillation (ENSO) episodes and East Asian (EA) winter surface air temperature (SAT) through the Pacific Decadal Oscillation (PDO). Strong and moderate ENSO episodes are classified by their amplitudes. The current work investigates the influence of moderate ENSO episodes on the EA winter SAT, especially moderate La Niña episodes, which show a close relationship with the EA winter SAT. To explore the PDO modulation effect on the influence of ENSO episodes, the

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