Modified London model for the determination of λ and ζ in a high κ superconductor

We present a modified London model suggested by Brandt [1–3] which introduces a finite vortex core size appropriate for isotropic superconductors in which the average internal field is less than approximately (1/4)H _c2. TheSR lineshape resulting from this model possesses a distinctive shape due to the magnetic penetration depth and the vortex core diameter (approximately equal to twice the coherence length ). However, for a given lineshape, there is a large range of values of and which produce nearly the same lineshape. Lineshape smearing caused by disorder in the vortex lattice increases uncertainty in values for and . If well-determined values of either (T) or (T) are not available from another technique, both of them can be determined bySR measurements alone if runs in more than one applied field at the same temperature are fit with and as shared parameters. We also present our method of estimating the degree of disorder in the vortex lattice.     

Testing shelled corn for aflatoxin, Part I: estimation of variance components

The variability associated with testing lots of shelled corn for aflatoxin was investigated. Eighteen lots of shelled corn were tested for aflatoxin contamination. The total variance associated with testing shelled corn was estimated and partitioned into sampling, sample preparation, and analytical variances. All variances increased as aflatoxin concentration increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. Test results on a lot with 20 parts per billion aflatoxin using a 1.13 kg sample, a Romer mill, 50 g subsamples, and liquid chromatographic analysis showed that the total, sampling, sample preparation, and analytical variances were 274.9 (CV = 82.9%), 214.0 (CV = 73.1 %), 56.3 (CV = 37.5%), and 4.6 (CV = 10.7%), respectively. The percentage of the total variance for sampling, sample preparation, and analytical was 77.8, 20.5, and 1.7, respectively.     

Performance of sampling plans to determine aflatoxin in farmers' stock peanut lots by measuring aflatoxin in high-risk-grade components

Five 2 kg test samples were taken from each of 120 farmers' stock peanut lots contaminated with aflatoxin. Kernels from each 2 kg sample were divided into the following U.S. Department of Agriculture grade components: sound mature kernels plus sound splits (SMKSS), other kernels (OK), loose shelled kernels (LSK), and damaged kernels (DAM). The kernel mass (g), aflatoxin mass (ng), and aflatoxin concentration (ng of aflatoxin/g of peanuts) were measured for each of the 2400 component samples. The variabilities associated with measuring aflatoxin mass (ng) in OK + LSK + DAM, or A(OLD)ng, and in LSK + DAM, or A(LD)ng, and aflatoxin concentration (ng/g) in OK + LSK + DAM, or A(OLD)ng/g, and in LSK + DAM, or A(LD)ng/g, were determined. The variance associated with measuring aflatoxin in each of the 4 combinations of components increased with aflatoxin, and functional relationships were developed from regression analysis. The variability associated with estimating the lot concentration from each of the 4 combinations of components was also determined. The coefficients of variation (CV) associated with estimating the aflatoxin for a lot with aflatoxin at 100 ng/g were 90, 86, 94 and 96% for aflatoxin masses A(OLD)ng and A(LD)ng and aflatoxin concentrations A(OLD)ng/g and A(LD)ng/g, respectively. The performance of aflatoxin sampling plans using the combination of aflatoxin masses in OK + LD + DAM and LD + DAM components was evaluated with a 2 kg test sample and a 50 ng/g accept/reject limit.     

Local Photodynamic Therapy Reduces Tissue Hyperplasia in an Experimental Restenosis Model

Abstract— Local photodynamic therapy may have potential in preventing myointimal hyperplasia after angioplasty. In this study, the effect of photodynamic therapy was evaluated in an experimental model of restenosis. Standardized unidirectional arterial injury with a directional atherectomy catheter was performed in porcine arteries. Animals were randomly allocated to four groups: group 1, unidirectional injury only; group 2, injury followed by local delivery of photosensitizer; group 3, injury followed by local exposure to monochromatic light; and group 4, where injury was followed by local drug delivery of photosensitizer and subsequent exposure to light (photodynamic therapy). Seven, 14 or 21 days after treatment, all experimental vessels were excised, fixed and processed for histology. An inflammatory and myoproliferative response was observed after injury in vessels from groups 1, 2 and 3. In group 4, after injury followed by photodynamic therapy, the myoproliferative response was significantly reduced. Thus, in this study, tissue hyperplasia after unidirectional injury was effectively suppressed by photodynamic therapy.     

Carrier ampholyte-free solution isoelectric focusing as a prefractionation method for the proteomic analysis of complex protein mixtures

The field of proteomics requires methods that offer high sensitivity and wide dynamic range. One of the strategies used to improve the dynamic range is sample prefractionation, such as microsolution isoelectric focusing (IEF). We have modified a commercial solution IEF instrument, the Rotofor, to prefractionate protein mixtures by carrier ampholyte-free solution IEF. The focusing chamber of the Rotofor was divided into several compartments by polyacrylamide membranes with imbedded Immobiline mixtures of specific pH values. When an electric field is applied, each protein migrates to the compartment confined by membranes with pH values flanking its isoelectric point. The approach was demonstrated for the focusing of myoglobin into a predicted compartment, as well as the separation of a complex soluble yeast protein mixture into several distinct fractions. The proteins were dissolved in water or 30% isopropanol. The method is applicable to both gel-based and solution-phase protein identification methods, without the need for further sample preparation.     

A density functional study of the glycine molecule: Comparison with post-Hartree–Fock calculations and experiment

The potential energy surface of un-ionized glycine has been explored with density functional theory. The performance of several nonlocal functionals has been evaluated and the results are presented in the context of available experimental information and post-Hartree–Fock quantum chemical results. The zero-point and thermal vibrational energies along with vibrational entropies play a very important role in determining the relative stability of glycine conformers; the realization of this has led to some revision and reinterpretation of the experimental results. Uncertainties in the vibrational contributions to the energy differences of several tenths of a kilocalorie/mole remain. The uncertainty in the vibrational free energy is even larger, about 1 kcal/mol. In the final analysis, we suggest that the best estimate of the electronic energy difference between the two lowest glycine conformers should be revised downward from 1.4 to 1.0 kcal/mol. Thirteen stationary points on the potential energy surface have been localized. For the majority of these, there is close agreement among various nonlocal density functionals and the post-Hartree–Fock methods. However, the second conformer (IIn), which has a strong hydrogen bond between the hydroxyl hydrogen and the nitrogen of the amine group, presents a distinct challenge. The relative energy of this conformer is extremely sensitive to the basis set, the level of correlation, or the functional used. The widely used BP86, PP86, and BP91 nonlocal functionals overestimate the strength of the hydrogen bond and predict that this conformer is the lowest energy structure. This contradicts both experiment and high-level post-Hartree–Fock studies. The adiabatic connection method (ACM) and the BLYP functional yield the correct order. The ACM method, in particular, gives energies which are in reasonable agreement with MP2, although these are somewhat low as compared with experiment. Based on this study, ACM should perform well for this type of bioorganic application, with typical errors of a few tenths of a kilocalorie/mole and only rarely exceeding 0.5 kcal/mol. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 : 1609–1631, 1997     

A fourth‐order method for numerical integration of age‐ and size‐structured population models

In many applications of age‐ and size‐structured population models, there is an interest in obtaining good approximations of total population numbers rather than of their densities. Therefore, it is reasonable in such cases to solve numerically not the PDE model equations themselves, but rather their integral equivalents. For this purpose quadrature formulae are used in place of the integrals. Because quadratures can be designed with any order of accuracy, one can obtain numerical approximations of the solutions with very fast convergence. In this article, we present a general framework and a specific example of a fourth‐order method based on composite Newton‐Cotes quadratures for a size‐structured population model. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009     

Transformation behavior of Ni-Mn-Ga/Si(100) thin film composites with different film thicknesses

A series of Ni_51.4Mn_28.3Ga_20.3/Si(100) thin film composites with different film thicknesses varying from 0.1 to 5 μm have been prepared by magnetron sputtering and subsequently annealed. X-ray powder diffraction patterns of the films show the features associated with the lattice-modulated martensitic phase and/or cubic austenite at room temperature. 220-fiber texture was confirmed by the X-rays measurements made at 150 °C. While the Curie temperature is almost film thickness independent, the martensitic transformation temperature shows a strong descended dependence in the submicron range. The substrate curvature measurements demonstrate that the forward and reverse martensitic transformation in the films is accompanied by the reversible relaxation and accumulation of residual stress, originally created by the thermal treatment due to the difference in thermal expansion of the film and substrate. The values of residual stresses measured by both substrate curvature and X-rays diffraction methods at constant temperatures are found to be dependent on the film thickness. This behavior appears in correlation with the thickness dependence of the transformation temperature.