Strain-driven light polarization switching in deep ultraviolet nitride emitters

Residual strain plays a critical role in determining the crystalline quality of nitride epitaxial layers and in modifying their band structure; this often leads to several interesting physical phenomena. It is found, for example, that compressive strain in AlxGa1-xN layers grown on AlyGa1-yN (x<y) templates results in an anti-crossing of the valence bands at considerably much higher Al composition than expected. This happens even in the presence of large and negative crystal field splitting energy for AlxGa1-xN layers. A judicious magnitude of the compressive strain can support vertical light emission (out of the c-plane) from AlxGa1-xN quantum wells up to x\approx 0.80, which is desirable for the development of deep ultraviolet light-emitting diodes designed to operate below 250nm with transverse electric polarization characteristics

Use of Radiation Absorbing Materials for Clearing Snow in Mountainous Areas

A comparative study of melting of snow by spreading different materials such as charcoal power, boiler ash, saw dust and common salt etc. On its surface under exposure to natural solar radiation has been made. The observations were carried out at Gulmarg at a height of about 9,000 ft. above sea level in the months of January, February and March 1965. It was observed that with the help of boiler ash, the melting rate of snow was increased to about 4 in the half inches per day which is about twice the rate without boiler ash. This material therefore seems to be very much suited to snow clearing operations in the mountain terrain

Driven diffusive systems with mutually interactive Langmuir kinetics

We investigate the simple one-dimensional driven model, the totally asymmetric exclusion process, coupled to mutually interactive Langmuir kinetics. This model is motivated by recent studies on clustering of motor proteins on microtubules. In the proposed model, the attachment and detachment rates of a particle are modified depending upon the occupancy of neighbouring sites. We first obtain continuum mean-field equations and in certain limiting cases obtain analytic solutions. We show how mutual interactions increase (decrease) the effects of boundaries on the phase behavior of the model. We perform Monte Carlo simulations and demonstrate that our analytical approximations are in good agreement with the numerics over a wide range of model parameters. We present phase diagrams over a selective range of parameters.Comment: 9 pages, 8 Figure

Friction of Pneumatic Rubber Tyres on Sand

The paper describes an apparatus for determining the rolling friction of pneumatic rubber tyres on sandy surfaces at different loads for different inflation pressures. The coefficient of friction is dependent on the size and shape of the tyre. The results refer only to measurements at a very low speed. Tyres having a flat tread and low inflation pressure are preferred on sand

Thermodynamic equilibrium and its stability for Microcanonical systems described by the Sharma-Taneja-Mittal entropy

It is generally assumed that the thermodynamic stability of equilibrium state is reflected by the concavity of entropy. We inquire, in the microcanonical picture, on the validity of this statement for systems described by the bi-parametric entropy $S_{_{\kappa, r}}$ of Sharma-Taneja-Mittal. We analyze the ``composability'' rule for two statistically independent systems, A and B, described by the entropy $S_{_{\kappa, r}}$ with the same set of the deformed parameters. It is shown that, in spite of the concavity of the entropy, the ``composability'' rule modifies the thermodynamic stability conditions of the equilibrium state. Depending on the values assumed by the deformed parameters, when the relation $S_{_{\kappa, r}}({\rm A}\cup{\rm B})> S_{_{\kappa, r}}({\rm A})+S_{_{\kappa, r}}({\rm B})$ holds (super-additive systems), the concavity conditions does imply the thermodynamics stability. Otherwise, when the relation $S_{_{\kappa, r}}({\rm A}\cup{\rm B})<S_{_{\kappa, r}}({\rm A})+S_{_{\kappa, r}}({\rm B})$ holds (sub-additive systems), the concavity conditions does not imply the thermodynamical stability of the equilibrium state.Comment: 13 pages, two columns, 1 figure, RevTex4, version accepted on PR

Magneto-Seebeck effect in spin-valve with in-plane thermal gradient

We present measurements of magneto-Seebeck effect on a spin valve with in-plane thermal gradient. We measured open circuit voltage and short circuit current by applying a temperature gradient across a spin valve stack, where one of the ferromagnetic layers is pinned. We found a clear hysteresis in these two quantities as a function of magnetic field. From these measurements, the magneto-Seebeck effect was found to be 0.82%.Comment: 10 Pages, 7 figure

Impact of Salt Stress on Carbohydrate Metabolism in Cicer Arietinum L.

Cereals are used as an important food of Indian diet. They are an important source of carbohydrates and proteins, so they are essential to a predominant diet. Chickpea (Cicer arietinum L.) is one of the important crops of India, mainly grown for their seeds which contain 20.6% protein, 2.2% fat and 61.2% carbohydrate, ranking next to wheat and barley both in acreage and in the production of grain. The major portion of crop production is consumed by the people in many forms like Dal, Besan, Crushed or whole grain, boiled or roasted gram or in sweet preparation. It is also used as a protein-rich diet for horses, and other cattle in the forms of soaked grain. Keeping the above views several Cicer varieties will be screened for their salt tolerance behaviour. Salt tolerant and salt susceptible variety will be selected for further comparative studies to expect that the findings of the present investigation would not only help with a better understanding of the mechanism of salt tolerant behaviour of Cicer at the physiological and biochemical levels and also suggest possibilities of selecting a variety suitable for salt stress condition