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DYNAMICAL AND STATISTICAL ASPECTS OF GRAVITATIONAL CLUSTERING IN THE UNIVERSE
SAHNI V. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1
We apply topological measures of clustering such as percolation and genus curves (PC & GC) and shape statistics to a set of scale free N-body simulations of large scale structure. Both genus and percolation curves evolve with time reflecting growth of non-Gaussianity in the N-body density field. The amplitude of the genus curve decreases with epoch due to non-linear mode coupling, the decrease being more noticeable for spectra with small scale power. Plotted against the filling factor GC shows very little evolution - a surprising result, since the percolation curve shows significant evolution for the same data. Our results indicate that both PC and GC could be used to discriminate between rival models of structure formation and the analysis of CMB maps. Using shape sensitive statistics we find that there is a strong tendency for objects in our simulations to be filament-like, the degree of filamentarity increasing with epoch.
KAPIL CHOPRA,V. SAHNI,R. S. MISHRA 대한설비공학회 2014 International Journal Of Air-Conditioning and Refr Vol.22 No.1
In this paper, comparative thermodynamic analysis of system-1 (multiple evaporators and compressorswith individual expansion valves) and system-2 (multiple evaporators and compressorswith multiple expansion valves) has been presented which is based on energy and exergy principles. The comparison of systems-1 and -2 using ecofriendly R410A, R290, R1234YF, R502,R404A, R152A and R134A refrigerants was done in terms of COP (energetic effciency), exergeticeffciency and system defect. Numerical model has been developed for systems-1 and -2 for ¯ndingout irreversibility and it was observed that system-2 is better system in comparison with system-1for selected refrigerants. It was also found that R152a shows better performances than otherconsidered refrigerants for both systems.
Kumari Sweeti,Tewari V. K.,Kumar Sanjeev,Sahni Ramesh K. 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.4
Purpose An electromyography (EMG) study was conducted during push and pull operations to evaluate the muscle fatigue of agricultural farm workers. Methods Twelve medically fit agricultural workers were selected for evaluation of muscular activity during push–pull operations, with the help of a laboratory setup, which was developed based on the ergonomic criteria of the uniform force application. The most used muscle during push and pull operation (middle deltoid MD, triceps brachii TR, brachioradialis BR, and biceps brachii BI) was selected for an EMG study. The uniform force or load (50, 100, 150, and 200 N) was applied during the experiment. Results The most activated or used muscles during the pushing and pulling operation were TR and BR, respectively. The activity of the middle deltoid and triceps brachii muscles was more during the pushing than the pulling task. Conclusion Root mean square (RMS) values for EMG activity were found to increase with increasing load in all the selected muscles, indicating that muscular loads were affected by the external load. A load of 200 N was found difficult to operate compared to other selected loads for push–pull operation for all the subjects. The TR muscle gets more fatigued during pushing because it is responsible for elbow extension, which is a primary movement in pushing. The BR muscle gets more fatigued because it is more activated during pull force application.