PW86–PW91 density functional calculation of vertical ionization potentials: Some implications for present‐day functionals

A total of 181 vertical ionization potentials (VIPs) of 41 molecules were calculated by density functional theory (DFT) employing the Perdew–Wang 1986 (PW86) exchange and Perdew–Wang 1991 (PW91) correlation functionals and using the aug‐cc‐pV5Z basis and experimental ground‐state geometries. The overall average absolute deviation (AAD) from experiment was found to be 0.55 eV and only 0.31 eV for linear molecules but 0.86 eV for nonplanar molecules. A number of VIPs were in error by over 2 eV. In particular, DFT performed most poorly when ionization was from an orbital with highly varying density gradients (which arise from the orbital's shape or compactness or through its density being distributed over a number of atoms). Indications are that many or all present‐day functionals suffer from the same failings. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 81: 34–52, 2001     

On the automorphisms of Paley's type II Hadamard matrix

In this paper we determine the automorphism group of Paley's type II Hadamard matrix.     

SENSITIVITY OF MONONUCLEAR CELLS TO UV RADIATION

Abstract—The viability of peripheral blood mononuclear cells, as measured by trypan blue dye exclusion, is decreased by exposure to UV radiation in vitro . The toxicity of the UV radiation is doseand wavelength-dependent; UVC is approximately 10 times more effective than UVB and 10⁵ times more effective than UVA.     

Rapid on-site radionuclide screening of aqueous waste streams using dip-stick technologies and liquid scintillation counting

Journal of Radioanalytical and Nuclear Chemistry - This paper describes an early-stage evaluation of a purpose-designed extraction/detection system that can be deployed by non-specialists either...     

Bio-deuterated cellulose thin films for enhanced contrast in neutron reflectometry

Novel molecularly smooth, flat and thin films of regenerated bio-deuterated cellulose were produced for enhanced contrast with adsorbed molecules in neutron reflectivity (NR) and for cellulose structure studies. The cellulose films were produced to study both the solid/air interface and the solid/liquid interface. Cellulose films with a wide range of scattering contrast were achieved by combining exchange of ¹H for deuterium on hydroxyl groups via water in the liquid phase and via biosynthesis of deuterated bacterial cellulose by Gluconacetobacter xylinus which can deuterate the hydrogens bonded to carbon atoms in cellulose. The deuterated cellulose combined with NR will help to provide new information on the interaction of various (bio)-macromolecules and cellulose. This includes quantifying and visualizing the density profile of polymers and biomolecules adsorbed onto cellulose surface. The potential of this material for IR studies of materials adsorbed to cellulose films is briefly discussed.     

Variations in the gross alpha and beta activity in surface waters at the Atomic Weapons Establishment Aldermaston (UK)

N,N,N′,N′-tetra-2-ethylhexyldiglycolamide (T2EHDGA) has been used for the preferential extraction of ⁹⁰Y from its mixture with ⁹⁰Sr from HNO₃ as well as HCl medium. The separation efficiencies have been found out under varying experimental conditions. The extracted species were determined from T2EHDGA concentration variation experiments carried out at 3 M nitric acid as well as HCl and were found out to be Y(X₃)₃·3(TEHDGA)_(o) for both the extraction systems, where X = NO₃ ⁻ and Cl⁻, respectively. Comparison of the T2EHDGA and TODGA based separation methods is also made. In order to avoid third phase formation, iso-decanol has been used as the modifier in all the studies. The modifier content was optimized to 30% for 4 M HCl and 20% for 6 M HNO₃ as the feed aqueous phases. Separation schemes were developed for the separation of carrier free ⁹⁰Y and the purity was checked by the half-life measurement method.     

Synthesis and photovoltaic performance of donor–acceptor polymers containing benzo[1,2‐b:4,5‐b′]dithiophene with thienyl substituents

Three alternating donor–acceptor copolymers have been synthesized by Stille coupling polymerization of 2,6‐(trimethyltin)?4,8‐bis(5‐dodecylthiophene‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene with 1,3‐dibromo‐5‐hexylthieno[3,4‐c]pyrrole‐4,6‐dione, 4,7‐dibromo‐1,3‐benzothiadiazole, and 5,7‐dibromo‐2,3‐didodecylthieno[3,4‐b]pyrazine, respectively. The synthesized polymers were tested in bulk heterojunction solar cells as blends with the acceptor [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM). The thienopyrroledione copolymer displayed a power conversion efficiency of 3.00% which was increased to 3.86% by application of the additive 1,8‐diiodooctane (DIO). Tapping mode atomic force microscopy analysis indicated that there was an increase in the phase separation between polymer and PCBM, leading to an improvement in the performance upon the addition of DIO. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2622–2630     

Circulating hemocytes from larvae of Melipona scutellaris (Hymenoptera,Apidae, Meliponini): Cell types and their role in phagocytosis

Infection in insects stimulates a complex defensive response. Recognition of pathogens may be accomplished by plasma or hemocyte proteins that bind specifically to bacterial or fungal polysaccharides. Several morphologically distinct hemocyte cell types cooperate in the immune response. Hemocytes attach to invading organisms and then isolate them by phagocytosis, by trapping them in hemocyte aggregates called nodules, or by forming an organized multicellular capsule around large parasites. In the current investigation the cellular in the hemolymph third instar larvae of M. scutellaris has been characterized by means of light microscopy analysis and phagocytosis assays were performed in vivo by injection of 0.5 μm fluorescence beads in order to identify the hemocyte types involved in phagocytosis. Four morphotypes of circulating hemocytes were found in 3rd instar larvae: prohemocytes, plasmatocytes, granulocytes and oenocytoids. The results presented plasmatocytes and granulocytes involved in phagocytic response of foreign particles in 3rd instar larvae of M. scutellaris.     

Robust estimation via minimum distance methods

Summary Given a fixed parametric family {P } it is desired to estimate. However, due to contaminations of various sorts, the data actually collected by the statistician follow a distribution that is close to, but possibly distinct from, theP 's. It is proved that, under these conditions and in an appropriate asymptotic framework, the minimum distance estimators of the Cramér-von Mises type are robust. Specification of a Cramér-von Mises weight functionH defines a notion of distance; each such choice ofH then delineates the kind of contamination possible, and leads to an estimator which defends optimally against it. When the theory is specialized to location models, various choices ofH lead to estimators asymptotically equivalent to such familiar ones as trimmed mean, median, Hodges-Lehmann estimator, and so forth. The framework developed herein provides some guidelines for choosing among the possible estimators, and suggests that the standard Cramér-von Mises estimator of location is probably as good a robust estimator as any.Supported by NSF grant MCS 75-10376