Analysis of precipitation and dissolution in overaged 7xxx aluminium alloys using DSC

To improve the understanding of the relation between composition, precipitation and the balance of strength and electrical conductivity (as a measure of the stress-corrosion resistance), a number of Al Zn Mg Cu Zr aluminium alloy plates with different Zn, Mg and Cu contents were produced and studied by Differential Scanning Calorimetry (DSC). It is shown that detailed analysis of the DSC data produces valuable information on the optimal Mg, Zn and Cu contents

A new "polarized version" of the Casimir Effect is measurable

We argue that the exactly computable, angle dependent, Casimir force between parallel plates with different directions of conductivity can be measured.Comment: One Figure, 11 page

Doubly diagonally dominant matrices

AbstractWe consider the class of doubly diagonally dominant matrices (A = [aij] ϵ Cn, n, ∥aii||ajj∥ ⩾ ∑k ≠ i |aik|∑k ⩞ j|ajk|, i ≠ j) and its subclasses. We give necessary and sufficient conditions in terms of the directed graph for an irreducibly doubly diagonally dominant matrix to be a singular matrix or to be an H-matrix. As in the case of diagonal dominance, we show that the Schur complements of doubly diagonally dominant matrices inherit this property. Moreover, we describe when a Schur complement of a strictly doubly diagonally dominant matrix is strictly diagonally dominant

Depairing field, onset temperature and the nature of the transition in cuprates

The depairing (upper critical) field $H_{c2}$ in hole-doped cuprates has been inferred from magnetization curves $M$-$H$ measured by torque magnetometry in fields $H$ up to 45 T. We discuss the implications of the results for the pair binding energy, the Nernst onset temperature, fluctuations and the nature of the Meissner transition at $T_c$.Comment: 4 pages, 5 figs., proc. M2S-HTSC-VIII, Dresden 2006, Physica (in press

SUSY-QCD Effect on Top-Charm Associated Production at Linear Collider

We evaluate the contribution of SUSY-QCD to top-charm associated production at next generation linear colliders. Our results show that the production cross section of the process $e^+e^-\to t\bar c{or}\bar t c$ could be as large as 0.1 fb, which is larger than the prediction of the SM by a factor of $10^8$.Comment: version to appear in PR

Saturation Physics of Threshold Heat-Flux Reduction

The saturation physics of ion-temperature-gradient-driven turbulence is examined in relation to the temperature-gradient variation of the heat flux, which can exhibit an upshift of the critical gradient for significant flux relative to the linear instability threshold. Gyrokinetic measurements of saturation properties and spectral energy transfer, which will be defined in Sec. II, are presented, indicating that the physics of saturation is fundamentally unchanged on either side of the upshifted gradient. To analyze heat transport below and above the upshifted critical gradient, a fluid model for toroidal ion-temperature-gradient turbulence is modified to include the kinetic instability threshold. The model and the heat flux are rendered in the eigenmode decomposition to track the dominant mode-coupling channel of zonal-flow-catalyzed transfer to a conjugate stable mode. Given linear and nonlinear symmetries, the stable mode level and the cross-correlation of the unstable and stable mode amplitudes are related to the unstable mode level via linear physics. The heat flux can then be written in terms of the unstable-mode level, which through a nonlinear balance depends on the eigenmode-dependent coupling coefficients and the triplet correlation time of the dominant coupled modes. Resonance in these quantities leads to suppressed heat flux above the linear threshold, with a nonlinear upshift of the critical gradient set by the resonance broadening of a finite perpendicular wavenumber and collisionality.</p

Cost-effectiveness of rotavirus immunization in vietnam: Exploring impacts of herd immunity and patterns of breastfeedingof

OBJECTIVES: : Rotavirus is the most common cause of severe diarrhoea worldwide. This study was designed to evaluate the cost-effectiveness of rotavirus immunization in Vietnam taking into account herd immunity and patterns of breastfeeding. The affordability of implementing universal rotavirus immunization was assessed based on both GAVI-subsidized and market vaccine prices for the next 5 years from the perspective of the Vietnamese health care system. METHODS: An age-structured birth cohort model for Vietnam was developed to compare two strategies of no vaccination and universal rotavirus vaccination in 2011. A lifetime time horizon was used with monthly time cycles for those under one year and annually thereafter. The analysis was performed under three breastfeeding scenarios: 1) 100% exclusive breastfeeding for children under 6 months; 2) 100% partial breastfeeding, and 3) 100% no breastfeeding. Herd immunity was explored in all scenarios. Monte Carlo simulations were used to examine the acceptability and affordability of the immunization strategy. RESULTS: Rotavirus immunization would effectively reduce severe cases of rotavirus during the first 5 years of life. Herd immunity makes rotavirus vaccination a cost-saving strategy under the GAVI-subsidized vaccine price in the case of partial breastfeeding and a cost-effective strategy in all breastfeeding scenarios under the market vaccine price. Affordability results showed that at the GAVI-subsidized vaccine price, rotavirus vaccination is affordable. CONCLUSIONS: This is the first study in developing countries considering herd immunity under rotavirus vaccination. If the indirect effect were considered, vaccination would become a cost-saving strategy. Given the high mortality rate of diarrhea in children under-five-years of age, our findings show rotavirus immunization to be an effective and “must-do” prevention strategy. Vaccination, however, only becomes affordable if Vietnam receives GAVI's financial support. In the next five years, Vietnam will need financial support from international organizations to implement rotavirus vaccination

Bound states of Θ+\Theta^+ in nuclei

We study the binding energy and the width of the $\Theta^+$ in nuclei, associated to the $K N$ and $K \pi N$ components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind the $\Theta^+$ in nuclei. Pauli blocking and binding effects on the $K N$ decay reduce considerably the $\Theta^+$ decay width in nuclei and medium effects associated to the $K \pi N$ component also lead to a very small width, as a consequence of which one finds separation between the bound levels considerably larger than the width of the states.Comment: Presentation in the 10th International Baryon Conference BARYON0