Investigations of reticulated porous alumina foam ceramics based on different coating techniques with the aid of μCT and statistical characteristics

Alumina foam ceramic filters were prepared due to the “replica technique”. The parameters of the two coating steps were varied to find the optimal processing route to prepare ceramic foam filters with a good homogeneous distribution of the strut thickness. Different additives for the slurry for the impregnation (first coating) step were investigated with the aid of rheological measurements. For the second coating step spraying as well as centrifuging techniques with different processing parameters were studied. The sintered foam structure (strut diameter, pore size and porosity) was characterized with the aid of CT-images and described with an image analysis software and statistical tools.     

Phase separation in a thermotropic copolyester via spinodal decomposition

Summary Novel experimental evidence is presented for the phase heterogeneity of a thermotropic copolyester containing 50 % of p-hydroxybenzdic acid (HB). Characteristic phase morphologies accompanying spinodal decomposition in polymer blends can be detected. Fractionation and a NMR-analysis demonstrate that the copolyester contains two constituents which differ in their HB-contents.     

High precision processing of flexible P3HT/PCBM modules with geometric fill factor over 95%

Flexible OPV modules, based on P3HT:PCBM as absorber layer, were manufactured with a power conversion efficiency over 3% and for a total area of 3500 mm² consisting of 14 in series interconnected cells. The modules utilize the excellent mechanical and the outstanding optical properties of sputtered transparent ITO-Metal-ITO (IMI) electrodes deposited on the PET foil on the one hand, and the combination of large area slot-die coating with high resolution ultrafast laser patterning on the other hand. The manufacturing of modules with outstanding performance was found to be reproducible. The right combination of innovative electrodes and smart roll-to-roll compatible processing technologies demonstrates a viable path towards high efficient industrial module technology.     

Indirect competitive enzyme-linked immunosorbent assay for the detection of native and heat-denatured bovine β-lactoglobulin in ewes' and goats' milk cheese

An indirect competitive enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of native and heat-denatured bovineβ-lactoglobulin (hd-β-lg) in goats' and ewes' milk cheese. Polyclonal antibodies raised in chicken against hd-β-lg were purified by immunadsorption chromatography on native bovine, ovine and caprineβ-lactoglobulins conjugated to CNBr-activated Sepharose. Although lactoglobulins from ewe, goat and cow have very similar amino acid sequences, crossreactivity was eliminated completely by this procedure. A commercially available goat-anti-chicken alkaline phosphatase conjugate was used as a secondary antibody to detect the anti-hd-β-lg antibodies bound to immobilized hd-β-lg. The detection limit of the assay was 100 ng/ml bovine native lg or hd-β-lg or 0.1–0.2% of cows' milk equivalent in cheese. Within a method validation study of the European Union, the ELISA test was successfully applied for the detection of native and heat-denatured bovine whey proteins in ewes' and goats' milk cheeses.     

Wide bandgap Cu(In,Ga)Se2 solar cells with improved energy conversion efficiency

We report on improvements to the energy conversion efficiency of wide bandgap (E_g > 1.2 eV) solar cells on the basis of CuIn_1−xGa_xSe₂. Historically, attaining high efficiency (>16%) from these types of compound semiconductor thin films has been difficult. Nevertheless, by using (a) the alkaline‐containing high‐temperature EtaMax glass substrates from Schott AG, (b) elevated substrate temperatures of 600–650 °C, and (c) high vacuum evaporation from elemental sources following National Renewable Energy Laboratory's three‐stage process, we have been able to improve the performance of wider bandgap solar cells with 1.2 < E_g < 1.45 eV. The current density–voltage (J–V) data we present includes efficiencies >18% for absorber bandgaps of ~1.30 eV and efficiencies of ~16% for bandgaps up to ~1.45 eV. In comparing J–V parameters in similar materials, we establish gains in the open‐circuit voltage and, to a lesser degree, the fill factor value, as the reason for the improved performance. The higher voltages seen in these wide gap materials grown at high substrate temperatures are due to reduced recombination. We establish the existence of random and discrete grains within the CIGS absorbers that yield limited or no generation/collection of minority carriers. We also show that interfacial recombination is the main mechanism limiting additional enhancements to open‐circuit voltage and therefore performance. Solar cell results, absorber materials characterization, and experimental details and discussion are presented. Copyright © 2012 John Wiley & Sons, Ltd.     

Massenspektroskopie von Thiogibberelllnen

Mass Spectroscopy of Thiogibberellins . The results of the positive ion (electron impact, desorption electron impact, low voltage electron impact, positive ion desorption chemical ionization, — EI, DEI, LEI, PIDCI), as well as negative ion (electron attachment — EA) mass spectra of 4 different types of thio gibberellins 6–9 are compared, and the fragmentation pathways are discussed.     

Folgeprodukte halogenierter Aldehyde. XV. Derivate der Aryl-(3,3,3-trichlor-2-hydroxy-propyl)-ketone

Derivatives of Halogenated Aldehydes. XV. Derivatives of Aryl 3,3,3-trichloro-2-hydroxy-propyl Ketones From aryl 3,3,3-trichloro-2-hydroxy-propyl ketones 1a – e , the oximes 6a – e , phenylhydrazones 5a – e , aryl 2,3,3,3-tetrachloro-propyl ketones 3b – d and aryl 3,3,3-trichloropropen(1)-yl ketones 2a – e are prepared. The phenylhydrazones 5a , b form the substituted Δ³-1,2,4-triazolines 4a , b by treatment with thiocyanic acid.