New interdigital design for large area dye solar modules using a lead‐free glass frit sealing

A new interdigital design for large area dye solar modules is developed for an area of 30×30 cm². This design requires fewer holes in the glass substrate for electrolyte filling, than the conventional strip design. A complete manufacturing process of this module—ranging from screen printed layers to semi‐automated colouring and electrolyte filling—in a laboratory‐scale baseline is illustrated. As primary sealing method, a durable glass frit sealing is used. It is shown, that the lead (Pb) content present in many glass frit powders contaminates the catalytic platinum electrode during the sintering process, resulting in a lowering of the fill factor. A screen printable lead‐free glass frit paste is developed, which solves this problem. Long term stability tests are presented on 2·5 cm² dye solar cells, which have been completely sealed with glass frit. In consecutively performed accelerated ageing tests under 85°C in the dark (about 1400 h) and continuous illumination with visible light (1 sun, about 1700 h), a 2·5 cm² dye solar cell with an electrolyte based on propylmethylimidazolium iodide showed an overall degradation of less than 5% in conversion efficiency. In a subsequently performed thermal cycling test (−40°C to +85°C, 50 cycles) a 2·5 cm² dye solar cell with the same electrolyte composition also showed only a slight degradation of less than 5% in conversion efficiency. Copyright © 2006 John Wiley & Sons, Ltd.     

Elucidation of a polychlorinated bipyrrole structure using enantioselective GC

A hexachloro congener (Q1-hex) of the natural heptachloro-1'-methyl-1,2'-bipyrrole Q1 was recently observed as a byproduct of the Q1 synthesis. NMR investigation confirmed that Q1-hex has a proton on a carbon in beta-position to a nitrogen. Three isomers are possible that fulfill this prerequisite; unfortunately, however, the NMR data were not sufficient to distinguish among the three structural variants. Because only one isomer of Q1-hex is expected to be chiral, we utilized enantioselective gas chromatography and two chiral stationary phases to separate the atropisomers. Baseline separation of the Q1-hex atropisomers was obtained on 10% chemically bonded permethyl-beta-cyclodextrin. In the full-scan mode, it was found that Q1-hex was racemic and that both atropisomers had identical mass fragmentation patterns. Partial resolution of the Q1-hex atropisomers was obtained on 25% tert-butyldimethylsilylated beta-cyclodextrin diluted in PS086. In concert with previous NMR data, these enantioseparations prove that the structure of Q1-hex is 2,3,3',4',5,5'-hexachloro-1'-methyl-1,2'-bipyrrole (5). To our knowledge, this is the first gas chromatographic separation of atropisomers of an axially chiral 1,2'-bipyrrole derivative.     

An Integrated Framework for Implementing Quality of Network Concepts

This paper presents an integrated framework for describing and implementing quality of network (QoN) concepts. It focuses on identifying a systems engineering framework for better understanding how to specify and implement QoN concepts. We demonstrate, by means of several examples, that the quality of service interfaces between the end user and the underlying network are very important. Finally, we provide insights as to future development efforts needed to realize the goal of high quality networks.     

Computerized documentation for a rural nursing intervention project

Complex traits are generally taken to be under the influence of multiple genes, which may interact with each other to confer susceptibility to disease. Statistical methods in current use for localizing such genes essentially work under single-gene models, either implicitly or explicitly. In genomic screens for complex disease genes, some of the marker loci must be in tight linkage with disease susceptibility genes. We developed a general multi-locus approach to identify sets of such marker loci. Our approach focuses on affected sib pair data and employs a nonparametric pattern recognition technique using artificial neural networks. This technique analyzes all markers simultaneously in order to detect patterns of locus interactions. When applied to previously published sib pair data on type I diabetes, our approach finds the same genes as in the published report in addition to some new loci. For a specific two-locus model of inheritance, the power of our approach is higher than that of the currently used analysis standard.     

Effect of dissociation pulse circuit inductance on the CuCl laser

The performance of the double-pulsed CuCI laser is improved by a decrease in the inductance of the dissociation pulse circuit. Higher efficiency is obtained due to a larger ground state copper atom population and lower optimum dissociation energy.