Frequency compensation for a class of DAE's arising in electrical circuits

Structured perturbations of regular pencils of the form , are considered which model the addition of a capacitance c in an electrical circuit in order to improve the frequency response. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Coupled cluster response theory in parameter subspaces

We introduce a response function formalism that enables smaller number of parameters than that defined in standard coupled cluster response theory. This is essential in the development of reduced scaling methods. The formalism is general and it applies to all parameterizations at all levels of the coupled cluster hierarchy. We show that to achieve physically reasonable results the parameterization must fulfill certain criteria. The linear response functions are derived and discussed in the context of optimized virtual orbitals and Cholesky decomposition of the cluster amplitudes. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Methodology for determination of 89Sr and 90Sr in radiological emergency: I. Scenario dependent evaluation of potentially interfering radionuclides

Early determination of ⁸⁹Sr and ⁹⁰Sr in radiological emergency is hampered by the presence of interfering short-lived fission products. In this study, three commonly used radioanalytical strategies for ⁸⁹Sr and ⁹⁰Sr were evaluated theoretically considering their suitability in a nuclear explosion scenario. The methods were evaluated with respect to the need for decay time of interfering short-lived strontium and yttrium isotopes, and reduction of other known interfering nuclides prior to measurement. The strategy shown to be most successful included initial separation of strontium and determination of ⁸⁹Sr, followed by an yttrium separation and counting of ⁹⁰Y. ⁸⁹Sr and ⁹⁰Sr could be determined about 5 and 9 days after a nuclear explosion, respectively.     

8-METHOXYPSORALEN DNA INTERSTRAND CROSS-LINKING OF THE RIBOSOMAL RNA GENES IN Tetrahymena thermophila. DISTRIBUTION, REPAIR AND EFFECT ON rRNA SYNTHESIS

Abstract— The distribution and repair of 8-methoxypsoralen-DNA interstrand cross-links in the ribosomal RNA gencs (rDNA) in Tetrahymena thermophila have been studied in vivo by Southern blot analysis. It is found that the cross-links at a density of ≤ 1/2 × 10⁴ base pairs (bp) are distributed equally between three domains (terminal spacer, transcribed region and central spacer) as defined by restriction enzyme analysis ( Bam HI and Cla I). It is furthermore shown that a dosage resulting in approximately one cross-link per rDNA molecule (21 kbp, two genes) is suficient to block KNA synthesis. Finally, it is shown that the cross-links in the rDNA molecules are repaired at equal rate in all three domains within 24 h and that RNA synthesis is partly restored during this repair period. The majority of the cells also go through one to two cell divisions in this period but do not survive.     

A fully extended tetrapeptide consisting of natural amino acids

FGFG is the first example of a non-protected peptide consisting of natural amino acids that adopt a fully extended conformation in the crystalline state.     

Measuring Luttinger liquid correlations from charge fluctuations in a nanoscale structure

We suggest an experiment to study Luttinger liquid behavior in a one-dimensional nanostructure, avoiding the usual complications associated with transport measurements. The proposed setup consists of a quantum box, biased by a gate voltage, and side coupled to a quantum wire by a point contact. Close to the degeneracy points of the Coulomb blockaded box, and in the presence of a magnetic field sufficiently strong to spin polarize the electrons, the setup can be described as a Luttinger liquid interacting with an effective Kondo impurity. Using exact nonperturbative techniques, we predict that the differential capacitance of the box will exhibit distinctive Luttinger liquid scaling with temperature and gate voltage.     

Steric effects are not the cause of the rate difference in hydrolysis of stereoisomeric glycosides

[structure: see text] A long-lived and plausible explanation as to why glycosides with axial substituents are more reactive than those with equatorial substituents was given in 1955 by Edward based on sterical hindrance being relieved in the transition state. Using model compounds 5, 6, 8, and 10, we here show conclusively that sterical hindrance is not the controlling factor in glycoside hydrolysis.