scholarly journals Brownian ratchets: How stronger thermal noise can reduce diffusion

2017 ◽  
Vol 27 (2) ◽  
pp. 023111 ◽  
Author(s):  
Jakub Spiechowicz ◽  
Marcin Kostur ◽  
Jerzy Łuczka
Keyword(s):  
Thermal Noise ◽  
Brownian Ratchets

Brownian Ratchets: Transport Controlled by Thermal Noise

1998 ◽  
Vol 80 (7) ◽  
pp. 1377-1380 ◽  
Author(s):  
J. Kula ◽  
T. Czernik ◽  
J. Łuczka
Keyword(s):  
Thermal Noise ◽  
Brownian Ratchets

Ultra-spatially resolved synchrotron powered FT-IR microspectroscopy of individual cells of biological material

1995 ◽  
Vol 53 ◽  
pp. 884-885
Author(s):  
David L. Wetzel ◽  
John A. Reffner ◽  
Gwyn P. Williams
Keyword(s):  
Thermal Noise ◽  
Spot Size ◽  
Acquisition Time ◽  
Thermal Source ◽  
Signal To Noise ◽  
Spatially Resolved ◽  
Good Spatial Resolution ◽  
Small Spot ◽  
Ft Ir ◽  
Ir Microspectroscopy

Synchrotron radiation is 100 to 1000 times brighter than a thermal source such as a globar. It is not accompanied with thermal noise and it is highly directional and nondivergent. For these reasons, it is well suited for ultra-spatially resolved FT-IR microspectroscopy. In efforts to attain good spatial resolution in FT-IR microspectroscopy with a thermal source, a considerable fraction of the infrared beam focused onto the specimen is lost when projected remote apertures are used to achieve a small spot size. This is the case because of divergence in the beam from that source. Also the brightness is limited and it is necessary to compromise on the signal-to-noise or to expect a long acquisition time from coadding many scans. A synchrotron powered FT-IR Microspectrometer does not suffer from this effect. Since most of the unaperatured beam’s energy makes it through even a 12 × 12 μm aperture, that is a starting place for aperture dimension reduction.

EFFECT OF CELLULAR MEMBRANE RESISTIVITY INHOMOGENEITY ON THE THERMAL NOISE-LIMIT

2015 ◽  
Vol 11 (3) ◽  
pp. 3171-3183
Author(s):  
Gyula Vincze
Keyword(s):  
Field Strength ◽  
Thermal Noise ◽  
Cellular Membrane ◽  
Thermal Limit ◽  
Low Frequencies ◽  
Membrane Resistivity ◽  
Noise Limit ◽  
The Asymmetry ◽  
Characteristic Field

Our objective is to generalize the Weaver-Astumian (WA) and Kaune (KA) models of thermal noise limit to the case ofcellular membrane resistivity asymmetry. The asymmetry of resistivity causes different effects in the two models. In the KAmodel, asymmetry decreases the characteristic field strength of the thermal limit over and increases it below the breakingfrequency (10  m), while asymmetry decreases the spectral field strength of the thermal noise limit at all frequencies.We show that asymmetry does not change the character of the models, showing the absence of thermal noise limit at highand low frequencies in WA and KA models, respectively.

scholarly journals Thermal Noise Decoupling of Micro-Newton Thrust Measured in a Torsion Balance

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1357
Author(s):  
Linxiao Cong ◽  
Jianchao Mu ◽  
Qian Liu ◽  
Hao Wang ◽  
Linlin Wang ◽  
...  
Keyword(s):  
Thermal Noise ◽  
Rotation Axis ◽  
Electrostatic Force ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
Torsion Balance ◽  
Positive Temperature ◽  
Thermal Drift ◽  
Low Thrust ◽  
Z Domain

The space gravitational wave detection and drag free control requires the micro-thruster to have ultra-low thrust noise within 0.1 mHz–0.1 Hz, which brings a great challenge to calibration on the ground because it is impossible to shield any spurious couplings due to the asymmetry of torsion balance. Most thrusters dissipate heat during the test, making the rotation axis tilt and components undergo thermal drift, which is hysteretic and asymmetric for micro-Newton thrust measurement. With reference to LISA’s research and coming up with ideas inspired from proportional-integral-derivative (PID) control and multi-timescale (MTS), this paper proposes to expand the state space of temperature to be applied on the thrust prediction based on fine tree regression (FTR) and to subtract the thermal noise filtered by transfer function fitted with z-domain vector fitting (ZDVF). The results show that thrust variation of diurnal asymmetry in temperature is decoupled from 24 μN/Hz1/2 to 4.9 μN/Hz1/2 at 0.11 mHz. Additionally, 1 μN square wave modulation of electrostatic force is extracted from the ambiguous thermal drift background of positive temperature coefficient (PTC) heater. The PID-FTR validation is performed with experimental data in thermal noise decoupling, which can guide the design of thermal control and be extended to other physical quantities for noise decoupling.

Thermal noise in contact atomic force microscopy

2021 ◽  
Vol 129 (23) ◽  
pp. 234303
Author(s):  
Chengfu Ma ◽  
Chenggang Zhou ◽  
Jinlan Peng ◽  
Yuhang Chen ◽  
Walter Arnold ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Thermal Noise ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Nano-Kelvin Thermometry and Temperature Control: Beyond the Thermal Noise Limit

2014 ◽  
Vol 112 (16) ◽  
Author(s):  
Wenle Weng ◽  
James D. Anstie ◽  
Thomas M. Stace ◽  
Geoff Campbell ◽  
Fred N. Baynes ◽  
...  
Keyword(s):  
Temperature Control ◽  
Thermal Noise ◽  
Noise Limit

scholarly journals Analysis of noise temperature sensitivity for the design of a broadband thermal noise primary standard

Metrologia ◽  
2012 ◽  
Vol 49 (4) ◽  
pp. 538-551 ◽  
Author(s):  
Alejandro Díaz-Morcillo ◽  
Antonio Lozano-Guerrero ◽  
Jaime Fornet-Ruiz ◽  
Juan Monzó-Cabrera
Keyword(s):  
Temperature Sensitivity ◽  
Thermal Noise ◽  
Primary Standard ◽  
Noise Temperature
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