Possible f-wave superconductivity in Sr2_2RuO4_4?

Until recently it has been believed that the superconductivity in Sr$_2$RuO$_4$ is described by p-wave pairing. However, both the recent specific heat and the magnetic penetration depth measurements on the purest single crystals of Sr$_2$RuO$_4$ appear to be explained more consistently in terms of f-wave superconductivity. In order to further this hypothesis, we study theoretically the thermodynamics and thermal conductivity of f-wave superconductors in a planar magnetic field. We find the simple expressions for these quantities when $H \ll H_{c2}$ and $T \ll T_{c}$, which should be readily accessible experimentally.Comment: 6 pages, 2 figure

IPASS TECHNICAL MANUAL

Research Methods/ Statistical Methods,

Effects of Dissipation on Quantum Phase Slippage in Charge Density Wave Systems

We study the effect of the dissipation on the quantum phase slippage via the creation of ``vortex ring'' in charge density wave (CDW) systems. The dissipation is assumed to come from the interaction with the normal electron near and inside of the vortex core. We describe the CDW by extracted macroscopic degrees of freedom, that is, the CDW phase and the radius of the ``vortex ring'', assume the ohmic dissipation, and investigate the effect in the context of semiclassical approximation. The obtained results are discussed in comparison with experiments. It turns out that the effect of such a dissipation can be neglected in experiments.Comment: 9 pages (revtex), 2 figures, using epsf.st

TRACKING THE GOVERNMENT SECTOR IN A NATURAL RESOURCE-BASED ECONOMY

In this paper, we describe the modeling of a resource-dependent economy, namely, Southeast Alaska, in monitoring the impact of federal, state and local government taxing and spending activities on the region. An important part of the modeling effort is construction of a readily accessible regional database for estimating critical economic relationships and variables that provide a baseline forecast series for the region. The Alaska Interactive Policy Analysis Simulation System (IPASS) makes use of the database in assessing the economic impacts of alternative resource management policies on state and local governments. IPASS is a computer-based, user-interactive economic forecasting and simulation system. The basic system is divided into eight modules: investment; final demand; production; regional export; population; labor force; employment; and primary inputs with government being the ninth module. It provides the quantitative framework for measuring and monitoring changes in regional economic activity and, also, for differentiating among the causal factors accounting for these changes. The individual modules form the IPASS shell that makes possible assessment of the effects of specific government activity on each industry and sector in the region's economy and, in turn, the effects of specific industry activity on each level and function of government.Community/Rural/Urban Development, Public Economics,

Theory of the critical current in two-band superconductors with application to MgB2

Using a Green's function formulation of the superfluid current j_s, where a momentum q_s is applied to the Cooper pair, we have calculated j_s as a function of q_s, temperature, and impurity scattering for a two-band superconductor. We consider both renormalized BCS and full strong-coupling Eliashberg theory. There are two peaks in the current as a function of q_s due to the two energy scales for the gaps and this can give rise to non-standard behavior for the critical current. The critical current j_c, which is given as the maximum in j_s, can exhibit a kink as a function of temperature as the maximum is transferred from one peak to other. Other temperature variations are also possible and the universal BCS behavior is violated. The details depend on the material parameters of the system, such as the amount of coupling between the bands, the gap anisotropy, the Fermi velocities, and the density of states of each band. The Ginzburg-Landau relation between j_c, the penetration depth lambda_L and thermodynamic critical field H_c, is modified. Using Eliashberg theory with the electron-phonon spectral densities given from bandstructure calculations, we have applied our calculations for j_s and j_c to the case of MgB2 and find agreement with experiment.Comment: 13 pages, 7 figures, submitted to PR

Relative Efficiency by Farm Size and the Green Revolution in Pakistan

Using the "unit output price" profit function, the study analyses the relative efficiency of (a) old versus new seeds, and (b) large versus small farms in the production of new varieties of wheat and rice in the Indus Basin of Pakistan. It is found that whereas farm .size has no effect on efficiency, high-yielding seeds are more efficient than seeds of old varieties. The study also finds that labour demand elasticities with respect to both land and capital are rather low

Cystatins as calpain inhibitors: Engineered chicken cystatin- and stefin B-kininogen domain 2 hybrids support a cystatin-like mode of interaction with the catalytic subunit of μ-calpain

Within the cystatin superfamily, only kininogen domain 2 (KD2) is able to inhibit μ- and m-calpain. In an attempt to elucidate the structural requirements of cystatins for calpain inhibition, we constructed recombinant hybrids of human stefin B (an intracellular family 1 cystatin) with KD2 and Delta L110 deletion mutants of chicken cystatin-KD2 hybrids. Substitution of the N-terminal contact region of stefin B by the corresponding KD2 sequence resulted in a calpain inhibitor of K-i = 188 nM. Deletion of L110, which forms a beta -bulge in family 1 and 2 cystatins but is lacking in KD2, improved inhibition of mu -calpain 4- to 8-fold. All engineered cystatins were temporary inhibitors of calpain due to slow substrate-like cleavage of a single peptide bond corresponding to Gly9-Ala10 in chicken cystatin. Biomolecular interaction analysis revealed that, unlike calpastatin, the cystatin-type inhibitors do not bind to the calmodulin-like domain of the small subunit of calpain, and their interaction with the mu -calpain heterodimer is completely prevented by a synthetic peptide comprising subdomain B of calpastatin domain 1. Based on these results we propose that (i) cystatin-type calpain inhibitors interact with the active site of the catalytic domain of calpain in a similar cystatin-like mode as with papain and (ii) the potential for calpain inhibition is due to specific subsites within the papain-binding regions of the general cystatin fold

How We Market Our Livestock- the Trends

Reports from the public stockyards and from the federally inspected points of slaughter give a partial but somewhat incomplete picture of livestock marketing in Iowa. In addition, we need lo understand how the patterns of marketing livestock have developed and changed

Novel vortex lattice transition in d-wave superconductors

We study the vortex state in a magnetic field parallel to the $c$ axis in the framework of the extended Ginzburg Landau equation. We find the vortex acquires a fourfold modulation proportional to $\cos(4\phi)$ where $\phi$ is the angle ${\bf r}$ makes with the $a$-axis. This term gives rise to an attractive interaction between two vortices when they are aligned parallel to $(1,1,0)$ or $(1,-1,0)$. We predict the first order vortex lattice transition at $B=H_{cr}\sim \kappa^{-1} H_{c2}(t)$ from triangular into the square lattice tilted by $45^\circ$ from the $a$ axis. This gives the critical field $H_{cr}$ a few Tesla for YBCO and Bi2212 monocrystals at low temperatures ($T\leq 10 K$).Comment: 6 pages, 4 figure