Synthesen mit Nitrilen, 23. Mitt.

Zusammenfassung Die Bedingungen für die Kondensation von Benzil mit monomerem und dimerem Malonsäurenitril werden überprüft und für das 2-Benzoyl-2-phenyl-äthylen-1,1-dicarbonitril (2a) sowie das 2-Amino-4-benzoyl-4-phenyl-1,3-butadien-1,1,3-tricarbonitril (1a) die Strukturen sichergestellt. Unter dem Einfluß von wäßrigen Alkalien erleidet2a eine 1,2-Arylverschiebung und durch Cyclisierung entsteht das 2,5-Dioxo-4,4-diphenyl-pyrrolidin-3-carbonitril (7a).

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Syntheses with nitriles, XXIII.: Anionotropic 1,2-Shift of aryl groups in benzil-malononitrile condensation products

The condensation conditions of benzil with monomeric and dimeric malononitrile have been reinvestigated and the structures of 2-benzoyl-2-phenyl-ethylene-1.1-dicarbonitrile (2a) and 2-amino-4-benzoyl-4-phenyl-1.3-butadiene-1.1.3-tricarbonitrile (1a) elucidated. With aqueous alkali2 undergoes 1.2-arylmigration and cyclization yielding 2.5 dioxo-4.4-diphenyl-pyrrolidine-3-carbonitrile (7a).

     

Untersuchungen über die photometrische Bestimmung von Tantal mit Pyrogallol

The optimum conditions for the photometric determination of tantalum with pyrogallol in sulphuric acid solution at 405 nm have been elaborated. The method has been checked statistically.     

Decomposition and interval arithmetic applied to global minimization of polynomial and rational functions

A recent global optimization algorithm using decomposition (GOP), due to Floudas and Visweswaran, when specialized to the case of polynomial functions is shown to be equivalent to an interval arithmetic global optimization algorithm which applies natural extension to the cord-slope form of Taylor's expansion. Several more efficient variants using other forms of interval arithmetic are explored. Extensions to rational functions are presented. Comparative computational experiences are reported.     

Imaging electron trajectories in a laser-wakefield cavity using betatron X-ray radiation

We demonstrate that betatron x-ray radiation accurately provides direct imaging of electrons trajectories accelerated in laser wakefields. Experimental far field x-ray beam profiles reveal that electrons can follow similar transverse trajectories with typical excursions of 1.5 microm+/-0.5 microm in the plane of laser polarization and 0.7 microm+/-0.2 microm in the plane perpendicular.     

Altering the emission behavior with the turn of a thiophene ring: the photophysics of condensed ring systems of alternating benzenes and thiophenes

Six aromatic compounds with embedded thiophenes differing in the number of rings (2-5) and thiophene orientation along the long axis of the molecule (syn, anti) were investigated. Photophysical properties, steady-state absorption, fluorescence, phosphorescence, lifetimes, quantum yields, and a comprehensive time-resolved spectroscopic analysis (femtosecond and nanosecond transient absorption spectroscopy) have been studied as a function of molecular structure.     

Is-ClusterMPP: clustering algorithm through point processes and influence space towards high-dimensional data

Advances in Data Analysis and Classification - Clustering via marked point processes and influence space, Is-ClusterMPP, is a new unsupervised clustering algorithm through adaptive MCMC sampling of...     

Robust optimization of internal transports at a parcel sorting center operated by Deutsche Post World Net

Competitiveness in global markets requires the ongoing identification and full utilization of improvement potential. To cut costs by means of process optimization, logistics service providers need to focus on efficient planning — not only for external but also for internal transports. This contribution will demonstrate that significant reductions in internal transports at one of the Deutsche Post World Net’s main parcel sorting centers can be achieved by applying the robust solution of a modified three-dimensional linear assignment model.     

Naturalness and Theoretical Constraints on the Higgs Boson Mass

Arbitrary regularization dependent parameters in Quantum Field Theory are usually fixed on symmetry or phenomenology grounds. We verify that the quadratically divergent behavior responsible for the lack of naturalness in the Standard Model (SM) is intrinsically arbitrary and regularization dependent. While quadratic divergences are welcome for instance in effective models of low energy QCD, they pose a problem in the SM treated as an effective theory in the Higgs sector. Being the very existence of quadratic divergences a matter of debate, a plausible scenario is to search for a symmetry requirement that could fix the arbitrary coefficient of the leading quadratic behavior to the Higgs boson mass to zero. We show that this is possible employing consistency of scale symmetry breaking by quantum corrections. Besides eliminating a fine-tuning problem and restoring validity of perturbation theory, this requirement allows to construct bounds for the Higgs boson mass in terms of $\delta m^{2}/m^{2}_{H}$ (where m _H is the renormalized Higgs mass and δm ² is the 1-loop Higgs mass correction). Whereas $\delta m^{2}/m^{2}_{H}<1$ (perturbative regime) in this scenario allows the Higgs boson mass around the current accepted value, the inclusion of the quadratic divergence demands $\delta m^{2}/m^{2}_{H}$ arbitrarily large to reach that experimental value.     

Antistatic Epoxy Coatings With Carbon Nanotubes Obtained by Cationic Photopolymerization

Antistatic epoxy coatings are obtained, for the first time, by cationic UV curing of an epoxy resin in the presence of a very low content of carbon nanotubes (CNTs). It is shown that the addition of only 0.025 wt.‐% of CNTs into the resin is sufficient to obtain a composite suitable for applications that require electrostatic discharge. An extended percolative structure that forms a conductive CNT network is clearly evidenced within the polymeric matrix, notwithstanding the very small CNT content. The use of such UV‐cured epoxy material systems for antistatic coatings is quite realistic and promising.