150 Years of India Post stamp was originally issued on 4 October 2004. The stamp is one among the set of four commemorative stamps, which marks the sesquicentennial year of the department of posts as it rededicates itself to the service of nation. On !st October 1854, India Post was born with a skeletal network of 701 post offices under the control of a Director General.
Madhubala stamp was originally issued on 18 March, 2008. The Department of Posts issued the commemorative stamp on Madhubala, one of the most enduring legends of Indian cinematic history.
Taj Mahal Stamp was issued on 16 December, 2004. The Department of Posts issued the commemorative postage stamp as the symbol of eternal love. It was printed by the Indian Security Press.
Bhagawadgeeta (the Divine Song of the Lord), stamp shows the traditional picture of Krishna and Arjuna on the battle field and a stanza 47 of chapter 2 of Bhagawadgeeta "Thy right id to work only, but never to its fruits". It was issued on August 25, 1978.
Vande Mataram stamp was originally issued on 30 December, 1976. Indian Posts and Telegraphs department issued a commemorative postage stamp, honouring National song and the first stanza of Vande Mataram is imprinted.
Republic of India, Inauguration Jan 26, 1950 stamp was originally issued on 26 January 1950. A new series of Postage stamps commemorating the inauguration of the republic of India was issued by the Indian Posts and Telegraphs department. A boy and a girl watching the procession of cavaliers carrying flags and blowing trumpets which herald India's attainment of full nationhood. This stamp was intended for Inland Postage.
This famous stamp was issued to commemorate India's historic tour of England in 1971. After losing only one match, India went on to win its first ever Test Series in a nail-biting finish. The stamp depicts a cricketer in characteristic poses of batting, bowling and wicket-keeping.
The Pride of India Collection is an official programme of Hallmark Group Limited issued under the Authority of India Post. It is the first Stamp Ingot Collection ever to be produced for India, and its release is strictly limited to 7500 editions worldwide. 25 stamps have been chosen to be preserved forever as engraved solid pure silver ingots, layered with pure 24-carat gold.
In 1778 the great exponent of the art of miniature painting, Nihal Chand, created the legendary face of the Kishangarh Radha, the quintessence of Indian womanhood and grace.
The stamp was issued to commemorate the 150th anniversary of the first World War of Independence in 2007. It shows the dramatic confrontation between zealous freedom fighters and the stolid ranks of hired Company infantry.
This thesis presents a theoretical study of linear and non-linear analyses of Rayleigh–Bénard–Marangoni/Rayleigh–Bénard electro convection in a micropolar fluid. The effects of non-uniform basic temperature gradient, suction–injection combination and gravity modulation have been studied in the presence of electric field. The effect of heat transfer in a micropolar fluid in the presence of electric field is also studied and results are presented graphically and discussed qualitatively. These problems assume greater importance in geophysics, astrophysics, oceanography, and engineering and in space situations with g-jitter connected with gravity stimulation study. Keeping in mind the importance and relevance of externally controlled internal convection in a micropolar liquid.
This thesis deals with the study of Rayleigh-Bénard-convection in a Newtonian fluid and micropolar fluid by replacing the classical Fourier law by non-classical Maxwell-Cattaneo heat flux law. The effects of second sound, non-uniform basic temperature gradients, suctioninjection-combination, temperature modulation and gravity modulation in
presence of external constraints like magnetic field and rotation are studied. The problems investigated in this thesis throw light on externally controlled convection in Newtonian and micropolar fluids in the presence of Maxwell-Cattaneo law. The problems investigated in this thesis deal with practical problems with very large heat fluxes and/or short time duration. With this motivation, we investigate in this thesis five problems and their summary is given below. (i) Effects of Coriolis force and non-uniform basic temperature gradients on the onset of Rayleigh-Bénard-Chandrasekhar convection with Maxwell-Cattaneo law The effect of non-uniform temperature gradient on RayleighBénard-Chandrasekhar convection in a rotating Newtonian fluid with
Maxwell-Cattaneo law is studied using the Galerkin technique. The eigenvalues is obtained for free-free, rigid-free and rigid-rigid velocity boundary combinations with isothermal and adiabatic boundaries. A linear stability analysis is performed. The influence of various parameters on the onset of convection has been analyzed. One linear and fiveix non-linear temperature profiles are considered and their comparative influence on onset is discussed. It is found that the results are noteworthy
at short times and the critical eigenvalues are less than the classical ones. It is shown that the system having magnetic field will delay in the onset of instability. In general, it is observed that step function and inverted parabolic temperature profile are the most destabilizing and stabilizing profiles. The range of values of the parameters of the problem for which oscillatory convection in the case of free-free isothermal boundary exists is also discussed. (ii) The effect of temperature modulation on the onset of RayleighBénard-Chandrasekhar convection using Maxwell-Cattaneo law The effect of imposed time-periodic boundary temperature (ITBT, also called temperature modulation) and magnetic field at the onset of Rayleigh-Bénard convection is investigated by making a linear analysis. The classical Fourier heat law is replaced by the non-classical MaxwellCattaneo law. The venezian approach is adopted in arriving at the critical Rayleigh number and wave number for small amplitude of ITBT. Three
cases of oscillating temperature field are examined: (a) symmetric, so that the wall temperatures are modulated in-phase, (b) asymmetric, corresponding to out-of-phase modulation and (c) only the lower wall is modulated. The temperature modulation is shown to give rise to sub-critical motion. The shift in the critical Rayleigh number is calculated
as a function of frequency and it is found that it is possible to advance or delay the onset of convection by time modulation of the wall temperatures. It is shown that the system is more stable when the boundary temperatures are modulated out of phase.x
(iii) The effect of gravity modulation on the onset of RayleighBénard-Chandrasekhar convection using Maxwell-Cattaneo law The effect of gravity modulation and magnetic field at the onset of Rayleigh-Bénard-Chandrasekhar convection is investigated by making a regular perturbation technique. The stability of the horizontal fluid layer heated from below is examined by assuming time-periodic body acceleration called g-jitter, which normally occurs in satellites and in vehicles connected with microgravity simulation studies. The venezian
approach is adopted in arriving at the critical Rayleigh number and wave number for small amplitude of gravity modulation. The shift in the critical Rayleigh number is calculated as a function of frequency of modulation. It is observed that gravity modulation leads to delayed convection. (iv) The effect of suction-injection-combination (SIC) on the onset of Rayleigh-Bénard-Chandrasekhar convection in a micropolar fluid with Maxwell-Cattaneo law The effect of suction-injection-combination (SIC) on the onset of Rayleigh-Bénard-Chandrasekhar convection in a micropolar fluid with Maxwell-Cattaneo law is studied using the Galerkin technique. The eigenvalue is obtained for free-free, rigid-free and rigid-rigid velocity boundary combinations with isothermal and adiabatic on the spinvanishing boundaries. A linear stability analysis is performed. The influence of various micropolar fluid parameters on the onset of convection has been analyzed. It is found that the effect of Prandtl number on the stability of the system is dependent on the SIC beingxi pro-gravity or anti-gravity. A similar Pe-sensitivity is found in respect of the critical wave number. The problem suggests an elegant method of external control of internal convection. (v) The effect of non-uniform temperature gradients on RayleighBénard-Chandrasekhar convection in a micropolar fluid with
Maxwell-Cattaneo law The effect of non-uniform temperature gradient on RayleighBénard-Chandrasekhar convection in a micropolar fluid with MaxwellCattaneo law is studied using the Galerkin technique. The eigenvalue is obtained for free-free, rigid-free and rigid-rigid velocity boundary combinations with isothermal and adiabatic on the spin-vanishing boundaries. A linear stability analysis is performed. The influence of various micropolar fluid parameters on the onset of convection has been
analyzed. Six different non-uniform temperature profiles are considered their comparative influence on onset is discussed. It is observed that the micropolar fluid layer heated from below is more stable compared to the classical Newtonian fluid layer.
