On Whitney type inequalities for local anisotropic polynomial approximation

We prove a multivariate Whitney type theorem for the local anisotropic polynomial approximation in $L_p(Q)$ with $1\leq p\leq \infty$. Here $Q$ is a $d$-parallelepiped in \RR^d with sides parallel to the coordinate axes. We consider the error of best approximation of a function $f$ by algebraic polynomials of fixed degree at most $r_i - 1$ in variable $x_i,\ i=1,...,d$, and relate it to a so-called total mixed modulus of smoothness appropriate to characterizing the convergence rate of the approximation error. This theorem is derived from a Johnen type theorem on equivalence between a certain K-functional and the total mixed modulus of smoothness which is proved in the present paper.Comment: 12 pages; the proofs of Theorems 1.2 and 2.2 and Lemma 3.1 are revised; typos are corrected; Acknowledgments are added; the results are unchange

Heavy flavor in heavy-ion collisions at RHIC and RHIC II

In the initial years of operation, experiments at the Relativistic Heavy Ion Collider (RHIC) have identified a new form of matter formed in nuclei-nuclei collisions at energy densities more than 100 times that of a cold atomic nucleus. Measurements and comparison with relativistic hydrodynamic models indicate that the matter thermalizes in an unexpectedly short time, has an energy density at least 15 times larger than needed for color deconfinement, has a temperature about twice the critical temperature predicted by lattice QCD, and appears to exhibit collective motion with ideal hydrodynamic properties - a "perfect liquid" that appears to flow with a near-zero viscosity to entropy ratio - lower than any previously observed fluid and perhaps close to a universal lower bound. However, a fundamental understanding of the medium seen in heavy-ion collisions at RHIC does not yet exist. The most important scientific challenge for the field in the next decade is the quantitative exploration of the new state of nuclear matter. That will require new data that will, in turn, require enhanced capabilities of the RHIC detectors and accelerator. In this report we discuss the scientific opportunities for an upgraded RHIC facility - RHIC II - in conjunction with improved capabilities of the two large RHIC detectors, PHENIX and STAR. We focus solely on heavy flavor probes. Their production rates are calculable using the well-established techniques of perturbative QCD and their sizable interactions with the hot QCD medium provide unique and sensitive measurements of its crucial properties making them one of the key diagnostic tools available to us.Comment: 96 pages, 53 figures. Accepted for publication in Physics Reports. Fixed typo in Fig. 15 captio

Enhanced carrier scattering rates in dilute magnetic semiconductors with correlated impurities

In III-V dilute magnetic semiconductors (DMSs) such as Ga$_{1-x}$Mn$_x$As, the impurity positions tend to be correlated, which can drastically affect the electronic transport properties of these materials. Within the memory function formalism we have derived a general expression for the current relaxation kernel in spin and charge disordered media and have calculated spin and charge scattering rates in the weak-disorder limit. Using a simple model for magnetic impurity clustering, we find a significant enhancement of the charge scattering. The enhancement is sensitive to cluster parameters and may be controllable through post-growth annealing.Comment: 4 pages, 3 figure

Effect of Alternative Wheat and Feed Grain Prices on Optimum Farm Plans and Income in Central South Dakota: Aurora, Brule, Charles Mix, Gregory and Jerauld Counties

The purpose of this report is to present some results of a cooperative research project between the South Dakota Agricultural Experiment Station and the Farm Production Economics Division, Economic Research Service, U. S. Department of Agriculture. This research contributes to a larger project-GP-5, Economic Problems in the Production and Marketing of Great Plains Wheat. The general objectives of the research undertaken in South Dakota were: ( 1) To provide economic data needed by farmers to make profitable adjustments in their farming systems and production practices and (2) To develop a research background for evaluating Government farm programs under varying assumptions

Effect of Alternative Wheat and Feed Grain Prices on Optimum Farm Plans and Income: Beadle, Clark, Codington, Day, Marshall and Roberts Counties

The purpose of this report is to present some results of a cooperative research project between the South Dakota Agricultural Experiment Station and the Farm Production Economics Division, Economic Research Service, U. S. Department of Agriculture. This research contributes to a larger project-GP-5, Economic Problems in the Production and Marketing of Great Plains Wheat. The general objectives of the research undertaken in South Dakota were: (1) to provide economic data needed by farmers to make profitable adjustments in their farming systems and production practices and (2) to develop a research background for evaluating government farm programs under varying assumptions

Effect of Alternative Wheat and Feed Grain Prices on Optimum Farm Plans and Income in Central South Dakota: Buffalo, Hand and Hyde Counties

The purpose of this report is to present some results of a cooperative research project between the South Dakota Agricultural Experiment Station and the Farm Production Economics Division, Economic Research Service, U. S. Department of Agriculture. This research contributes to a larger project-GP-5, Economic Problems in the Production and Marketing of Great Plains Wheat. The general objectives of the research undertaken in South Dakota were (1) To provide economic data needed by farmers to make profitable adjustments in their farming systems and production practices and (2) To develop a research background for evaluating Government farm programs under varying assumptions

Effect of Alternative Wheat and Feed Grain Prices on Optimum Farm Plans and Income in Cetnral South Dakota: Brown and Spink Counties

The purpose of this report is to present some results of a cooperative research project between the South Dakota Agricultural Experiment Station and the Farm Production Economics Division, Economic Research Service, U. S. Department of Agriculture. This research contributes· to a larger project-GP-5, Economic Problems in the Production and Marketing of Great Plains Wheat. The general objectives of the research undertaken in South Dakota were: (1) to provide economic data needed by farmers to make profitable adjustments in their farming systems and production practices and (2) to develop a research background for evaluating government farm programs under varying assumptions