What is a design? How should we classify them?

Design theory crosses the boundary between mathematics and statistics, and includes a wide range of disparate types of design. In this paper we present a classification scheme which aims to include as many important types as possible, based on a balance among concept, representation and use.     

The effects of O deficiency on the electronic structure of rutile TiO2

Ab initio density functional calculations (plane wave GGA, CASTEP) were performed to determine the effect of O deficiency on the electronic structure of rutile, TiO₂. O deficiency was introduced through either the removal of O or the insertion of interstitial Ti atoms. At physically realistic concentrations of O vacancies in the rutile lattice (i.e. 25% and less) O deficiency results in the population of the bottom of the conduction band, the location of the Ti 3d orbitals in the pure structure, increasingly with increasing vacancy concentration. We propose that this could be confused with the formation and population of gap states especially where O vacancies occur in isolated positions in the lattice. In contrast, Ti interstitials introduce a defect state into the energy gap, without an overall reduction in the size of the energy gap. O vacancies result in a spin polarized solution, whereas Ti interstitials do not.     

Reflection spectroscopy in microstructured light scattering materials

Summary A theoretical model is derived that describes the influence of lateral light diffusion in a scattering medium on the absorptivity of an absorber spot on top of the substrate. The model uses the lateral resolved reflectivity under point irradiation that has been analyzed experimentally with a scanning-micro-laser-reflectometer. The model allows quantification of the absorptivity by one single equation that contains only the mean radial diffusion length of light and the spot area. Experiment and theory are applied to typical substrates for thin layer chromatography (alumina, silica, cellulose). The diffusion lengths in these substrates are given and the absorptivities of the spots are calculated as a function of the spot area.     

Investigation of multiwavelength clock recovery based on heterodyne beats of sideband-filtered signal

We investigate a new parallel all-optical clock recovery scheme based on heterodyne beats of an optical sideband-filtered signal. The oscillating clock signal is recovered when the filtered sideband is combined with a stable local oscillator. The filtering is performed with an optical resonator, which by nature provides possibility for multiwavelength operation. The local oscillator could be realized by a multiwavelength laser, whose emission wavelengths are injection seeded with carrier wavelengths of the input data. The output signal of such a configuration benefits from a reduced bit-pattern effect and a stable offset level. The sideband filtering is demonstrated for 23 simultaneous channels at 100 GHz DWDM grid, each hosting a data stream of 10 Gbit/s.     

An example of a two-sided Wilcoxon signed rank test which is not unbiased

Although the theory of rank tests is rather complete in the one-sided case, it was not even known in 1959, whether the Wilcoxon two-sample test and other similar tests are unbiased against the two-sided alternatives (Lehmann (1959,Testing Statistical Hypotheses, p. 240, Wiley, New York)). A partial answer to this question was given by Sugiura in 1965, who found, that the test named above may be biased (Sugiura (1965,Ann. Inst. Statist. Math.,17, 261–263)). According to Lehmann (1986,Testing Statistical Hypotheses, 2nd ed., pp. 322–324, Wiley, New York) it seems to be still open, whether the same is true for the WILCOXON one-sample test, which is also known as WILCOXON signed rank test. This will be shown in the present paper.     

Common luminescence intensity fluctuations of single particle and single molecules in non-conducing matrices

Optical spectroscopy in combination with wide field or confocal optical microscopy enables the investigation of single quantum objects such as organic molecules, II/VI semiconductor quantum dots and silicon nanocrystals. They all have fluctuations of luminescence intensities on time scales longer than μs in common. A comparison reveals that despite the large differences of the nature of the respective quantum objects, the intensity fluctuations are related to a slow ionisation process followed by a trapping of the photoejected charge in the non-conducing environment. Detailed aspects of the dynamics are controlled by the dielectric properties of the matrix.     

Algebras of Random Operators Associated to Delone Dynamical Systems

We carry out a careful study of operator algebras associated with Delone dynamical systems. A von Neumann algebra is defined using noncommutative integration theory. Features of these algebras and the operators they contain are discussed. We restrict our attention to a certain C ^*-subalgebra to discuss a Shubin trace formula.     

Correction: Phytol-based novel adjuvants in vaccine formulation: 1. assessment of safety and efficacy during stimulation of humoral and cell-mediated immune responses

This is a correction article.     

Memory effects in gas chromatographic detection with a microwave-induced plasma

Capillary gas chromatography coupled to microwave-inducedplasma detection furnishes sensitivity adequate for trace analysis when the signal is monitored at a carbon emission line. Work performed with one of these systems at high electronic gain for the carbon signal has revealed solvent band widths in excess of four minutes; these impeded quantification of peaks eluting after the solvent. This report discusses two phenomena which could be related to the unexpected intensity of this solvent response: photomultiplier tube saturation and carbon deposits in the quartz plasma discharge tube.