852 research outputs found
Non-Equilibrium Surface Tension of the Vapour-Liquid Interface of Active Lennard-Jones Particles
We study a three-dimensional system of self-propelled Brownian particles
interacting via the Lennard-Jones potential. Using Brownian Dynamics
simulations in an elongated simulation box, we investigate the steady states of
vapour-liquid phase coexistence of active Lennard-Jones particles with planar
interfaces. We measure the normal and tangential components of the pressure
tensor along the direction perpendicular to the interface and verify mechanical
equilibrium of the two coexisting phases. In addition, we determine the
non-equilibrium interfacial tension by integrating the difference of the normal
and tangential component of the pressure tensor, and show that the surface
tension as a function of strength of particle attractions is well-fitted by
simple power laws. Finally, we measure the interfacial stiffness using
capillary wave theory and the equipartition theorem, and find a simple linear
relation between surface tension and interfacial stiffness with a
proportionality constant characterized by an effective temperature.Comment: 12 pages, 5 figures (Corrected typos and References
Forecasting minimum temperature during winter and maximum temperature during summer at Delhi
A knowledge of minimum temperature during winter and maximum temperature during summer is a very useful for individuals, as well as for organisations whose workers and machines have to operate in the open, e.g. the armed forces, railways, roadways, tourism, etc. Accurate forecasts of minimum temperature during winter help in the prediction of cold-wave conditions and those of maximum temperature during summer help in the prediction of heat-wave conditions over northern India. Models for forecasting the minimum temperature during December and the maximum temperature during May at Delhi have been developed using surface and upper-air meteorological data from 1984-89. The results of testing the models on independent data from recent years (1994-95) are presented. The results are encouraging and more than 80% of the forecasts are correct within ±2°C. Possible reasons for large deviations are also investigated
N1-benzenesulfonyl-2-pyrazoline hybrids in neurological disorders
A novel series of 1,3,5-trisubstituted-2-pyrazolines (5a-5t) was prepared via Claisen Schmidt condensation, followed by heterocyclization with hydrazine hydrate, substitution of N1 hydrogen of 2-pyrazoline nucleus with 4-chlorobenzenesulfonylchloride, applying conventional and green chemistry approaches. Among the two, microwave assisted organic synthesis (MAOS) emerged as a better synthetic tool in terms of faster reaction rate and high yield. Various physicochemical and spectral studies were conducted to characterize the synthesized derivatives including- IR, Mass, 1H-NMR, 13C-NMR and elemental analysis. During pharmacological evaluation, compound 5b showed excellent anti-anxiety activity and compound 5k exhibited the best antidepressant effect at the tested doses, 50 and 100 mg/kg b.w., being comparable to diazepam and imipramine, respectively. The docking experiments confirmed the probable mechanism of neuropharmacological action, showing excellent affinity towards MAO-A target protein, which was also evidenced from some of the key interactions with binding site residues Ala68, Tyr69 and Phe352. Furthermore, complimentary in silico pharmacokinetic recital without any potential risk of neurotoxicity (as evaluated by rotarod and actophotometer tests), or carcinogenicity, mutagenicity, reproductive toxicity, acute toxicity and irritancy (as predicted by LAZAR and OSIRIS programs) signified their probable use in depression and anxiety disorders
Forecasting of thunderstorms in the pre-monsoon season at Delhi
Accurate prediction of thunderstorms during the pre-monsoon season (April-June) in India is essential for human activities such as construction, aviation and agriculture. Two objective forecasting methods are developed using data from May and June for 1985-89. The developed methods are tested with independent data sets of the recent years, namely May and June for the years 1994 and 1995. The first method is based on a graphical technique. Fifteen different types of stability index are used in combinations of different pairs. It is found that Showalter index versus Totals total index and Jefferson's modified index versus George index can cluster cases of occurrence of thunderstorms mixed with a few cases of non-occurrence along a zone. The zones are demarcated and further sub-zones are created for clarity. The probability of occurrence/non-occurrence of thunderstorms in each sub-zone is then calculated. The second approach uses a multiple regression method to predict the occurrence/nonoccurrence of thunderstorms. A total of 274 potential predictors are subjected to stepwise screening and nine significant predictors are selected to formulate a multiple regression equation that gives the forecast in probabilistic terms. Out of the two methods tested, it is found that the multiple regression method gives consistently better results with developmental as well as independent data sets; it is a potential method for operational use
2-Pyrazoline derivatives in neuropharmacology
A novel series of 1,3,5-trisubstituted-2-pyrazoline derivatives (PFC-1 to PFC-16) were synthesized
in a three step reaction using conventional and microwave assisted green chemistry approach. The
synthesized derivatives were characterized and their chemical structures were established by
various physicochemical methods such as IR, Mass, 1H-NMR, 13C-NMR and elemental analysis. The
synthesized compounds were tested for their neurophar- macological potential. The compounds
exhibited significant antidepressant and anti-anxiety activities against var- ious behavioral in
vivo models. Compounds PFC-3 and PFC-12 were found to be the most active derivatives in the series.
The 2-pyrazoline analogs, having 2-hydroxyphenyl and anthracen-9-yl substitution at 3rd position
while 4-benzyloxyphenyl and 4-methylphenyl substitution at 5th position, were decisive in eliciting
good antidepressant and anxiolytic properties, respectively. The docking experiments revealed that
the synthesized derivatives were potential inhibitors of MAO-A protein, which plays a central role
in managing depression and anxiety disorders. The most potent derivatives were found to be involved
in some key interactions with Tyr407, Tyr444, Phe352 and Ala68 amino acid residues at the binding
site of MAO-A protein. All the synthesized derivatives successfully passed the pharmacokinetic
barriers of absorption, distribution, metabolism and elimination as predicted using in silico
techniques without showing any substantial indication of acute and neurotoxicity. This was further
confirmed in the laboratory by performing acute toxicity studies as per OECD guidelines
Noise resistant audio-visual verification via structural constraints
We propose a piecewise linear classifier for use as the decision stage in a two-modal verification system, comprised of a face expert and a speech expert. The classifier utilizes a fixed decision boundary that has been specifically designed to account for the effects of noisy audio conditions. Experimental results show that, in clean conditions, the proposed classifier is outperformed by a traditional weighted summation decision stage (using both fixed and adaptive weights); however, in high noise conditions the classifier obtains better performance than the fixed approach and has similar performance as the adaptive approach, with the advantage of having a fixed (non-adaptive) structure
Texts in school
One of the many forms of illiteracy that we encounter
around us is the lack of perception about processes
of social change. Matching this is a ‘block’ against
acknowledging the validity of the life of people who are
‘different’ -who are the ‘other’. Whether as social activists,as bureaucrats, as experts, or as consultants engaged in monitoring and reviewing programs, we expect the ultimate transformations as a result of the effort we are engaged in. We do not recognize that these efforts are merely elements in a larger process
Polynomial Features for Robust Face Authentication
In this paper we introduce the DCT-mod2 facial feature extraction technique which utilizes polynomial coefficients derived from 2-D DCT coefficients of spatially neighbouring blocks. We evaluate its robustness and performance against three popular feature sets for use in an identity verification system subject to illumination changes. Results on the multi-session VidTIMIT database suggest that the proposed feature set is the most robust, followed by (in order of robustness and performance): 2-D Gabor wavelets, 2-D DCT coefficients and PCA (eigenface) derived features. Moreover, compared to Gabor wavelets, the DCT-mod2 feature set is over 80 times quicker to compute
- …