scholarly journals Tuning the performance of a micrometer-sized Stirling engine through reservoir engineering

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Niloyendu Roy ◽  
Nathan Leroux ◽  
A. K. Sood ◽  
Rajesh Ganapathy
Keyword(s):  
Stirling Engine ◽  
Reservoir Engineering ◽  
Operating Speed ◽  
Noisy Environment ◽  
Heat Engines ◽  
Non Gaussian ◽  
Noise Statistics

AbstractColloidal heat engines are paradigmatic models to understand the conversion of heat into work in a noisy environment - a domain where biological and synthetic nano/micro machines function. While the operation of these engines across thermal baths is well-understood, how they function across baths with noise statistics that is non-Gaussian and also lacks memory, the simplest departure from the thermal case, remains unclear. Here we quantified the performance of a colloidal Stirling engine operating between an engineered memoryless non-Gaussian bath and a Gaussian one. In the quasistatic limit, the non-Gaussian engine functioned like a thermal one as predicted by theory. On increasing the operating speed, due to the nature of noise statistics, the onset of irreversibility for the non-Gaussian engine preceded its thermal counterpart and thus shifted the operating speed at which power is maximum. The performance of nano/micro machines can be tuned by altering only the nature of reservoir noise statistics.

scholarly journals Improved Process Monitoring Scheme Using Multi-Scale Independent Component Analysis

2021 ◽  
Author(s):  
K Ramakrishna Kini ◽  
Muddu Madakyaru
Keyword(s):  
Fault Detection ◽  
Independent Component Analysis ◽  
Component Analysis ◽  
Independent Component ◽  
Noisy Environment ◽  
Process Data ◽  
Multi Scale ◽  
Efficient Information ◽  
Non Gaussian

AbstractThe task of fault detection is crucial in modern chemical industries for improved product quality and process safety. In this regard, data-driven fault detection (FD) strategy based on independent component analysis (ICA) has gained attention since it improves monitoring by capturing non-gaussian features in the process data. However, presence of measurement noise in the process data degrades performance of the FD strategy since the noise masks important information. To enhance the monitoring under noisy environment, wavelet-based multi-scale filtering is integrated with the ICA model to yield a novel multi-scale Independent component analysis (MSICA) FD strategy. One of the challenges in multi-scale ICA modeling is to choose the optimum decomposition depth. A novel scheme based on ICA model parameter estimation at each depth is proposed in this paper to achieve this. The effectiveness of the proposed MSICA-based FD strategy is illustrated through three case studies, namely: dynamic multi-variate process, quadruple tank process and distillation column process. In each case study, the performance of the MSICA FD strategy is assessed for different noise levels by comparing it with the conventional FD strategies. The results indicate that the proposed MSICA FD strategy can enhance performance for higher levels of noise in the data since multi-scale wavelet-based filtering is able to de-noise and capture efficient information from noisy process data.

Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah
Keyword(s):  
High Efficiency ◽  
Combustion Engine ◽  
Renewable Energy Sources ◽  
Stirling Engine ◽  
Energy Sources ◽  
Heat Engines ◽  
Stirling Engines ◽  
Parabolic Dish ◽  
Mechanical Devices ◽  
And Control

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

Light Induced Changes in the Non-Gaussian Noise Statistics in Doped Hydrogenated Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
J. Fan ◽  
J. Kakalios
Keyword(s):  
Amorphous Silicon ◽  
Gaussian Noise ◽  
Hydrogenated Amorphous Silicon ◽  
Noise Power ◽  
Defect Creation ◽  
Non Gaussian ◽  
Noise Statistics ◽  
Induced Changes ◽  
Many Body Interactions ◽  
Hydrogenated Amorphous

The power spectrum of coplanar current fluctuations in n-type doped hydrogenated amorphous silicon (a-Si:H) has been measured before and after metastable defect creation by light soaking. The average magnitude and spectral slope of the 1/f noise are not affected by illumination, however significant changes in the higher order statistics are observed. Associated with the decrease of conductivity upon light soaking (the Staebler-Wronski effect), there is a decrease in the correlation of the noise power which characterize the non-Gaussian noise in the annealed state. These changes in the noise statistics are reversible by annealing. The light-induced changes in the non-Gaussian statistics provide experimental support for models of light induced defect creation which involve long-ranged and many body interactions.

scholarly journals Underwater surveillance in non-Gaussian noisy environment

2020 ◽  
Vol 53 (1-2) ◽  
pp. 250-261
Author(s):  
B Omkar Lakshmi Jagan ◽  
S Koteswara Rao
Keyword(s):  
Kalman Filter ◽  
Lower Bound ◽  
Extended Kalman Filter ◽  
Gaussian Noise ◽  
Unscented Kalman Filter ◽  
Doppler Frequency ◽  
Gaussian Mixture ◽  
Noisy Environment ◽  
Sampled Measurements ◽  
Non Gaussian

The aim of this paper is to evaluate the performance of different filtering algorithms in the presence of non-Gaussian noise environment for tracking underwater targets, using Doppler frequency and bearing measurements. The tracking using Doppler frequency and bearing measurements is popularly known as Doppler-bearing tracking. Here the measurements, that is, bearings and Doppler frequency, are considered to be corrupted with two types of non-Gaussian noises namely shot noise and Gaussian mixture noise. The non-Gaussian noise sampled measurements are assumed to be obtained (a) randomly throughout the process and (b) repeatedly at some particular time samples. The efficiency of these filters with the increase in non-Gaussian noise samples is discussed in this paper. The performance of filters is compared with that of Cramer-Rao Lower Bound. Doppler-bearing extended Kalman filter and Doppler-bearing unscented Kalman filter are chosen for this work.

Multiplicative Noise and Non-Gaussianity: A Paradigm for Atmospheric Regimes?

2005 ◽  
Vol 62 (5) ◽  
pp. 1391-1409 ◽  
Author(s):  
Philip Sura ◽  
Matthew Newman ◽  
Cécile Penland ◽  
Prashant Sardeshmukh
Keyword(s):  
Large Scale ◽  
Multiplicative Noise ◽  
Probability Distributions ◽  
Joint Probability ◽  
Joint Probability Distribution ◽  
Stochastic Perturbations ◽  
The Past ◽  
State Dependent ◽  
Non Gaussian ◽  
Noise Statistics

Abstract Atmospheric circulation statistics are not strictly Gaussian. Small bumps and other deviations from Gaussian probability distributions are often interpreted as implying the existence of distinct and persistent nonlinear circulation regimes associated with higher-than-average levels of predictability. In this paper it is shown that such deviations from Gaussianity can, however, also result from linear stochastically perturbed dynamics with multiplicative noise statistics. Such systems can be associated with much lower levels of predictability. Multiplicative noise is often identified with state-dependent variations of stochastic feedbacks from unresolved system components, and may be treated as stochastic perturbations of system parameters. It is shown that including such perturbations in the damping of large-scale linear Rossby waves can lead to deviations from Gaussianity very similar to those observed in the joint probability distribution of the first two principal components (PCs) of weekly averaged 750-hPa streamfunction data for the past 52 winters. A closer examination of the Fokker–Planck probability budget in the plane spanned by these two PCs shows that the observed deviations from Gaussianity can be modeled with multiplicative noise, and are unlikely the results of slow nonlinear interactions of the two PCs. It is concluded that the observed non-Gaussian probability distributions do not necessarily imply the existence of persistent nonlinear circulation regimes, and are consistent with those expected for a linear system perturbed by multiplicative noise.

Non-Gaussian Noise Statistics in Undoped Hydrogenated Amorphous Silicon

1994 ◽  
Vol 336 ◽  
Author(s):  
G. M. Khera ◽  
J. Kakalios
Keyword(s):  
Gaussian Noise ◽  
Hydrogen Diffusion ◽  
Statistical Tests ◽  
Careful Consideration ◽  
Conductance Fluctuations ◽  
History Of ◽  
Non Gaussian ◽  
Noise Statistics ◽  
Hydrogenated Amorphous ◽  
Second Spectrum

ABSTRACTMeasurements of coplanar conductance fluctuations in undoped a-Si:H are described. Statistical tests show that the 1/f noise is non-Gaussian and has a power-law frequency dependent second spectrum, as observed in n-type a-Si:H. By careful consideration of the thermal history of the sample, the noise statistics are found to be different above and below the equilibration temperature, which has been associated with hydrogen diffusion. These results suggest that the non-Gaussian noise in a-Si:H is influenced by the motion of bonded hydrogen and is not significantly dependent upon doping.

scholarly journals Noise resistance territorial intensity-based optical flow using inverse confidential technique on bilateral function

2021 ◽  
Vol 10 (6) ◽  
pp. 3240-3248
Author(s):  
Darun Kesrarat ◽  
Vorapoj Patanavijit
Keyword(s):  
Optical Flow ◽  
Motion Vector ◽  
Image Sequences ◽  
Error Vector Magnitude ◽  
Noisy Environment ◽  
Noise Resistance ◽  
Accuracy Rate ◽  
Optical Flow Method ◽  
Non Gaussian ◽  
Vector Magnitude

This paper presents the use of the inverse confidential technique on bilateral function with the territorial intensity-based optical flow to prove the effectiveness in noise resistance environment. In general, the image’s motion vector is coded by the technique called optical flow where the sequences of the image are used to determine the motion vector. But, the accuracy rate of the motion vector is reduced when the source of image sequences is interfered by noises. This work proved that the inverse confidential technique on bilateral function can increase the percentage of accuracy in the motion vector determination by the territorial intensity-based optical flow under the noisy environment. We performed the testing with several kinds of non-Gaussian noises at several patterns of standard image sequences by analyzing the result of the motion vector in a form of the error vector magnitude (EVM) and compared it with several noise resistance techniques in territorial intensity-based optical flow method.

scholarly journals Experimental evaluation of piston motion modification to improve the thermodynamic power output of a low temperature gamma Stirling engine

2021 ◽  
Vol 313 ◽  
pp. 04002
Author(s):  
Michael Nicol-Seto ◽  
David Nobes
Keyword(s):  
Low Temperature ◽  
Power Output ◽  
Stirling Engine ◽  
Maximum Power ◽  
Piston Motion ◽  
Heat Engines ◽  
Stirling Engines ◽  
Thermodynamic Performance ◽  
Engine Power ◽  
The Ideal

Stirling engines are a variety of heat engines which are capable of using heat from various sources including low temperature renewables. This work examines performance of a lab scale low temperature gamma type Stirling engine with a drive train modified with oval elliptical gears. The gears were added to dwell the engine piston motion to attempt to improve the thermodynamic performance of the engine by better replicating the ideal Stirling cycle. A variety of dwelling piston configurations were tested on both the displacer and power piston. It was observed that that the piston dwelling had the anticipated effect of changing the engine indicator diagrams to more closely resemble the ideal cycle, however there were no substantial improvements to maximum engine power. It was observed that dwelling the displacer piston caused substantial reductions to engine running speeds and resulted in maximum power being reduced. In the case of power piston dwelling the indicator diagram was enlarged and there were slight increases to maximum power production. Overall the added complexity of dwelled piston motion systems is not likely an advantageous method of increasing the power output of low temperature difference Stirling engines.

scholarly journals On Illustrating Carnot’s General Proposition by Means of Reversible Stirling Engines

2020 ◽  
Author(s):  
C Naaktgeboren ◽  
Klunger Arthur Éster Beck ◽  
Jean-Marc Stephane Lafay
Keyword(s):  
Second Law Of Thermodynamics ◽  
Stirling Engine ◽  
Working Fluid ◽  
Second Law ◽  
Working Fluids ◽  
Heat Engines ◽  
General Proposition ◽  
Stirling Engines ◽  
Fluid Properties

Carnot’s general proposition, also referred to as one of Carnot’s principles, states that the work producing potential of heat—harvested by reversible heat engines—is independent on the working fluid and on engine internal details, being only a function of the temperatures of the reservoirs with which the engine exchanges heat. This concept, usually presented to ME students in the context of the second law of thermodynamics, is usually proven by contradiction, using second law concepts and abstractions, without concrete examples, even though Carnot’s proposition mentions concrete things such as working fluids and engine internal details. This work proposes to document the usage of reversible Stirling engine models that take the engine arrangement and fluid properties into account towards illustrating the validity of Carnot’s general proposition.

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