An Analytic Study on Controlling Duffing Chaos in Amplitude Domain and in Frequency Domain

2005 ◽  
Author(s):  
Jie-Hua Peng ◽  
Jia-Shi Tang
Keyword(s):  
Frequency Domain ◽  
Chaotic Motion ◽  
Analytical Study ◽  
Duffing Oscillator ◽  
Small Region ◽  
Critical Ratio ◽  
Frequency Limit ◽  
Limited Region ◽  
Combined Action ◽  
Made In

An analytical study on the chaos control of Duffing oscillator both in amplitude domain and in frequency domain is made in this paper. By means of the combined action of harmonically parametrical perturbation and forcing perturbation and suitably adjusting the parameters of perturbations, the chaotic motion of Duffing oscillator can be effectively controlled in a small region in the parametric space. We find that, in the amplitude domain, the chaotic motion exists only in the region where the ratio of the amplitudes of the perturbations is large than critical ratio, and, in the frequency domain, the chaotic motion exists only in a limited region where the frequency of perturbation is lower than superior frequency limit and larger than inferior frequency limit. The inferior frequency limit and superior frequency limit of chaotic region are discovered and determined firstly. An analytical expression of the critical ration of the amplitudes of forcing and parametrical perturbations is established.

Studies on the Abundance, Distribution and Feeding Habits of some West African Mosquitos

1933 ◽  
Vol 24 (4) ◽  
pp. 493-510 ◽  
Author(s):  
J. A. Kerr
Keyword(s):  
Feeding Habits ◽  
Small Region ◽  
West African ◽  
Extensive Search ◽  
New Information ◽  
Tree Holes ◽  
Fallen Leaves ◽  
Almost All ◽  
Breeding Place ◽  
Made In

Almost all of the studies here reported were made in one small region, so that very little new information was secured on the ranges of the species of mosquitos under consideration.Our investigations regarding breeding-places were limited to a few species. Aëdes vittatus was found occasionally breeding in tree-holes in Ibadan. Aëdes irritans adults were taken at Ibadan, which is so far inland that this species must sometimes breed in places other than crab-holes at the edges of salt or brackish water. We did not, however, find the larvae of this species at Ibadan. The favourite breeding-place of Eretmopodites chrysogaster was found to be small collections of water in fallen leaves (especially those of cocoa trees) lying in moist and densely shaded places. Because of the abundance of Mansonia africana in places practically free from Pistia, we conclude that in the vicinity of Lagos it must breed abundantly on other plants. The long flight range of this species was taken into consideration in arriving at this conclusion. An extensive search failed, however, to reveal these plants. M. uniformis, also abundant in the vicinity of Lagos, does not breed there upon Pistia, but an extensive search failed to reveal its breeding-place.

Chaotic Motion in the Vicinity of Separatrix of a Parametrically Driven Duffing Oscillator With a Twin-Well Potential

2001 ◽  
Author(s):  
Albert C. J. Luo
Keyword(s):  
Chaotic Motion ◽  
Duffing Oscillator

Abstract The conditions for the (M:1) and (2M:1) resonances inside and outside of the separatrix of the parametrically driven Duffing oscillator are determined. The onset of such resonance in the vicinity of separatrix is investigated analytically and numerically. The results presented in this article can be applied to the post-buckled structures under parametric excitations.

The dispersion of matter in turbulent flow through a pipe

1954 ◽  
Vol 223 (1155) ◽  
pp. 446-468 ◽  
Keyword(s):  
Turbulent Flow ◽  
Capillary Tube ◽  
Resistance Coefficient ◽  
Mean Flow ◽  
Combined Action ◽  
Flow Through ◽  
The Mean ◽  
Coefficient Of Diffusion ◽  
Good Agreement ◽  
Made In

The dispersion of soluble matter introduced into a slow stream of solvent in a capillary tube can be described by means of a virtual coefficient of diffusion (Taylor 1953 a ) which represents the combined action of variation of velocity over the cross-section of the tube and molecluar diffusion in a radial direction. The analogous problem of dispersion in turbulent flow can be solved in the same way. In that case the virtual coefficient of diffusion K is found to be 10∙1 av * or K = 7∙14 aU √ γ . Here a is the radius of the pipe, U is the mean flow velocity, γ is the resistance coefficient and v * ‘friction velocity’. Experiments are described in which brine was injected into a straight 3/8 in. pipe and the conductivity recorded at a point downstream. The theoretical prediction was verified with both smooth and very rough pipes. A small amount of curvature was found to increase the dispersion greatly. When a fluid is forced into a pipe already full of another fluid with which it can mix, the interface spreads through a length S as it passes down the pipe. When the interface has moved through a distance X , theory leads to the formula S 2 = 437 aX ( v * / U ). Good agreement is found when this prediction is compared with experiments made in long pipe lines in America.

Turbulent Wakes in Pressure Gradients

1963 ◽  
Vol 30 (4) ◽  
pp. 518-524 ◽  
Author(s):  
P. G. Hill ◽  
U. W. Schaub ◽  
Y. Senoo
Keyword(s):  
Eddy Viscosity ◽  
Analytical Study ◽  
Positive Pressure ◽  
Stream Velocity ◽  
Moderate Pressure ◽  
Pressure Gradients ◽  
Momentum Integral ◽  
Theoretical Considerations ◽  
Acceptable Agreement ◽  
Made In

The application of moderate pressure gradients can exercise a large influence on the decay of wakes produced by obstructions in a flow field. In fact, a positive pressure gradient may arrest completely the decay process and cause the relative wake size to grow rapidly. This phenomenon could exist in any diffusing passage whose entrance flow has a wake-type distortion. Such a nonuniformity, due to a blade or a strut or other cause of stagnation-pressure variation in the stream, could lead to diffuser stall, as has been demonstrated experimentally. An analytical study of the problem has been made on the basis of measurements made in the M.I.T. Gas Turbine Laboratory. Theoretical considerations have led to a very convenient calculation formula which shows quite acceptable agreement with experimental data. The methods employ momentum integral equations and an “eddy viscosity” which is uniform across the wake and proportional to the product of the local free-stream velocity and the momentum thickness.

AN ANALYTICAL STUDY OF CHROMOSOME BEHAVIOR IN A WHEAT HAPLOID

1955 ◽  
Vol 33 (1) ◽  
pp. 11-30 ◽  
Author(s):  
Clayton Person
Keyword(s):  
Triticum Aestivum ◽  
Inverse Relationship ◽  
Analytical Study ◽  
Triticum Aestivum L ◽  
Chromosome Movement ◽  
Chromosome Behavior ◽  
Polar Groups ◽  
End To End ◽  
Made In

Bivalents, univalents, end-to-end and side-by-side associations, also chromosome distributions to the poles were associatively recorded for each of approximately 2000 meta-anaphase cells of a haploid Triticum aestivum L. It was demonstrated that the distribution of the univalents to the polar groups was not random. An inverse relationship between side-by-side association and bivalent frequencies was also demonstrated, and this formed the first in a series of analytical steps which led to a description of chromosome movement in the haploid. The validity of certain assumptions concerning chromosome behavior was tested using the χ2 method; for others, confirmatory observations were made in monosomic cells.

Reduction of Noise at the Design Stage: A Case Study of a Lightly Loaded Assembly

1969 ◽  
Vol 184 (1) ◽  
pp. 593-614 ◽  
Author(s):  
M. A. Satter ◽  
B. Downs ◽  
G. R. Wray
Keyword(s):  
Analytical Study ◽  
Design Stage ◽  
Acoustic Absorption ◽  
Noise Generation ◽  
Noise Emission ◽  
Design Changes ◽  
Damping Materials ◽  
Lower Noise ◽  
Made In

An experimental and analytical study is made of the noise emission from the drawroll assembly of a textile draw-twisting machine. As an alternative to resorting to acoustic absorption techniques or the use of expensive high damping materials, investigations are made into the basic method of noise generation in the assembly. This leads to the incorporation of small design changes and the significantly lower noise emission thereby achieved is compared with the original emission. Aimed at the machine designer, the presentation is made in a straightforward, non-mathematical fashion.

scholarly journals PHARMACEUTICO-ANALYTICAL STUDY OF CHAUSATHPRAHARI PIPPALI CHURNA

2021 ◽  
pp. 25-32
Author(s):  
Rajendra Barfa ◽  
Vijay Shreebharti ◽  
Amit Mishra ◽  
Dimpal Sharma ◽  
Amit Kumar Sharma ◽  
...  
Keyword(s):  
Present Article ◽  
Analytical Study ◽  
Herbal Remedy ◽  
Pharmacological Action ◽  
World Market ◽  
Safety And Efficacy ◽  
Pharmaceutical Technology ◽  
The World ◽  
Digestive Disorders ◽  
Made In

Ayurvedic pharmaceutics is one of the fastest growing sectors in the world market. Globalization expects pharmaceutical standardization. Competition in pharma industry expects good quality products which have documentation regarding safety and efficacy issues. Ancient heritage blended with current updated pharmaceutical technology helps in better appreciation. Chausath Prahari Pippali Churna is a classical Ayurvedic formualtion mentioned in Ayurvedsarasamghraha a renowned text of Ayurveda, which is useful in Vata and Kapha diseases. It has potent herbal remedy for both respiratory and digestive disorders. It is prepared by Bhavana with Phanta (hot infusion) of Badipippali to Chhotipippalichurna upto 64 Prahar (192hrs) to make it more strong and efficient formulation. The attempt is made in the present article to assess its pharmacological action and analytical aspect while processing the drug – Chausath Prahari Pippali Churna (CPP).

scholarly journals The Greening of the warehousing industry in Ontario : an analytical study of the extent of present day environmental sustainability programs

2021 ◽  
Author(s):  
Anna Patricia Wycher
Keyword(s):  
Environmental Sustainability ◽  
Business Strategy ◽  
Analytical Study ◽  
Third Party ◽  
Third Party Logistics ◽  
Current State ◽  
State Of Practice ◽  
Available Information ◽  
Future Work ◽  
Made In

The purpose of the paper is to explore the extent to which the Ontario warehousing industry has embraced environmental sustainability within its business strategy. This will provide a needed baseline on the current state of practice in the Province. This could also lay the foundation for future work in Ontario, particularly with respect to where improvements can be made. Data was collected through a review of Leonard’s Guide, a content analysis of publicly available information, and a survey of warehousing companies in Ontario. Multiple methods of collecting data were utilized for triangulation and to protect against the possibility not enough data would be available by one alone. The findings indicate that there have been some inroads made in implementing environmental sustainability programs within the warehousing industry of Ontario, but there is still room for improvement. The findings also indicate that third-party logistics (3PL) are more likely than warehousing/distribution companies to implement environmental sustainability programs, as are companies which had their trade areas beyond the borders of Canada.

scholarly journals U-6 An analytical study of Ibn-e-Hazam’s Confrontation on the Suspicions Ahadith about Sadd-ul-Zarai

2020 ◽  
Vol 4 (1) ◽  
pp. 81-90
Author(s):  
Fakharud Din ◽  
Muhammad Imran
Keyword(s):  
Analytical Study ◽  
Point Of View ◽  
Counter Narrative ◽  
The World ◽  
Made In

It is only the comprehension of Islamic in the legislation in the world that it encompasses the change, evolution or developments being made in different areas of life to accommodate the changes   inegislation or to address the changes, Islamic jurists laid down different principles of fiqah.one of these principle is sad u-zaraey which is known as the “prohibition of evasive legal devices”. As difference in opinion is also existing in all the areas of life, similarly difference of opinions is existing among the Islamic jurists in describing this principle as well. One of the jurists who are possessing the counter narrative of sad u-zaraey is ibn e hazam. In this article research has been made in order to elaborate the ibn e hazam,s point of view about sadd u zaraey and also the vice versa opinion of other jusrists. It is also discussed with example that how the principle of sad u-zaraey is important in Islamic legislation.

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