Particle-hole condensates of higher angular momentum in hexagonal systems

Hexagonal lattice systems (e.g. triangular, honeycomb, kagome) possess a multidimensional irreducible representation corresponding to $d_{x^2-y^2}$ and $d_{xy}$ symmetry. Consequently, various unconventional phases that combine these $d$-wave representations can occur, and in so doing may break time-reversal and spin rotation symmetries. We show that hexagonal lattice systems with extended repulsive interactions can exhibit instabilities in the particle-hole channel to phases with either $d_{x^2-y^2}+d_{xy}$ or $d+id$ symmetry. When lattice translational symmetry is preserved, the phase corresponds to nematic order in the spin-channel with broken time-reversal symmetry, known as the $\beta$ phase. On the other hand, lattice translation symmetry can be broken, resulting in various $d_{x^2-y^2}+d_{xy}$ density wave orders. In the weak-coupling limit, when the Fermi surface lies close to a van Hove singularity, instabilities of both types are obtained in a controlled fashion.Comment: 6 pages, 3 figures. Journal reference adde

Extension of Ruiz Criterion for Evaluation of 3-D Fretting Fatigue Damage Parameter

AbstractFretting fatigue is an important consideration in the design and optimization of mechanical systems and assemblies in the recent times. Empirical approaches, multi-axial fatigue considerations and fracture mechanics approaches are considered for assessing fretting fatigue damages at contact interfaces of assemblies. Ruiz criteria is an effective empirical approach for evaluation of Fretting Fatigue Damage Parameter (FFDP) and has been demonstrated in two dimensional fretting studies of a typical dovetail interface problem. The current paper considers the extension of Ruiz criterion for assessing fretting fatigue damage parameter for three dimensional problems. Two approaches viz. summation of FFDP computed independently along the two slip directions and combined maximum principal-shear stress approach have been proposed for the FFDP evaluation, considering three dimensional stress and slip components over contact interface. FFDP evaluation using maximum principal-shear stress approach is observed to be more appropriate for three dimensional problem

A model approach to groundwater quality of Anekal Taluk, Bangalore Urban district

Application of linear regression anal. is very much significant to construct the predictive model using the present groundwater quality data from which, helps to predict the futuristic quality of groundwater of particular area. Here, 1026 groundwater samples of 272 villages were collected and analyzed for 14 parameters for physico-​chem. and biol. quality of groundwater. Karl-​Pearson Correlation coeffs., r, were used and attempts were made to develop the linear regression equations (y = Ax + B) for significantly correlated parameters. The results of the linear model emphasizes a pos. and significant correlation among the water quality parameters

Testability Analysis of Synchronous Sequential Circuits Based On Structural Data

Bounds on test sequence length can be used as a testability measure. We give a procedure to compute the upper bound on test sequence length for an arbitrary sequential circuit. We prove that the bound is exact for a certain class of circuits. Three design rules are specified to yield circuits with lower test sequence bounds

Some developmental stages of Caranx kalla Cuv. & Val.

These fish, when disturbed, were found to take shelter under the bell of the medusae. Judging from their movements, however, it may be mentioned that they seem to be cautious while moving about inside the bell, probably to avoid the stinging cells of the medusae. It is weIl-known that several species of carangids gather around floating objects such as, pieces of wood, coconut shell, medusae, etc_ and the principle of lure-line fishing is basea on this peculiar habit of carangids

Note on the organic production in the inshore waters of the Gulf of Mannar

Although considerable data are available on the standing crop of plankton, practically no information is available on the daily production of organic matter in our waters and there fore investigations were started in 1957, with ' a view to measuring the magnitude of production of organic matter by the plankton alga and its fluctuations