Micro-deformation of flexible substrate for electronic devices during handling prior to lithography patterning

The dimensional stability of poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) foils during the handling and production process, is crucial for the quality of the final multilayer flexible electronic devices. The foil-on-carrier (FOC) - foil/adhesive/Si-wafer sandwich - is a handling method, which is currently used to temporary attach the foil to a Si-wafer carrier during the lithography processing. This handling method ensures good surface flatness of the foils during the processing. However this technique has two drawbacks: (1) it creates an in-plane micro-deformation of the PEN foil and (2) bending of FOC due to the lamination procedure and lithography processing. In this article the temperature dependence of in-plane foil deformation and bending of FOC was reported and the final curing step of lamination procedure was identified as the main source of in-plane deformation and bending. Finally the resultant stresses introduced to FOC by the curing step derived from the experimental measurements were compared to stress values calculated from the Stoney’s and Ohring’s equations.     

Fabrication of Transistors on Flexible Substrates: from Mass‐Printing to High‐Resolution Alternative Lithography Strategies

In this report, the development of conventional, mass‐printing strategies into high‐resolution, alternative patterning techniques is reviewed with the focus on large‐area patterning of flexible thin‐film transistors (TFTs) for display applications. In the first part, conventional and digital printing techniques are introduced and categorized as far as their development is relevant for this application area. The limitations of conventional printing guides the reader to the second part of the progress report: alternative‐lithographic patterning on low‐cost flexible foils for the fabrication of flexible TFTs. Soft and nanoimprint lithography‐based patterning techniques and their limitations are surveyed with respect to patterning on low‐cost flexible foils. These show a shift from fabricating simple microlense structures to more complicated, high‐resolution electronic devices. The development of alternative, low‐temperature processable materials and the introduction of high‐resolution patterning strategies will lead to the low‐cost, self‐aligned fabrication of flexible displays and solar cells from cheaper but better performing organic materials.     

Possibilities of using inhomogeneity in light energy distribution for estimating the degree of coherence of superposing waves

The paper presents a new method for determining the degree of coherence of superposing plane linearly polarized waves converging at the angle of 90°. The spatial modulation of polarization, which causes the spatial modulation of the averaged values of the Poynting vector, presets the modulation of the volume energy density. Such an inhomogeneous optical field can affect nano-sized particles randomly caught in this field. The paper shows that the maximum velocity of "trapping" the particles into the regions of maximum averaged values of the Poynting vector determines the degree of coherence of interacting waves.     

Stevia rebaudiana Bertoni – Überblick über die Forschung an einer verbotenen Pflanze und derer möglichen Einsätze

Stevia rebaudiana stammt aus dem Grenzgebiet zwischen Paraguay und Brasilien. Die F?higkeit dieser Pflanze, kalorienarme sü?schmeckende Glycoside in ihren Bl?ttern zu akkumulieren, macht sie für verschiedene Anwendungen in Form eines Zuckerersatzproduktes interessant. Obwohl die Pflanze und auch die Extrakte daraus seit Jahrhunderten von der einheimischen Bev?lkerung Lateinamerikas genutzt werden, sind S. rebaudiana und diese Extrakte (Stevioside) in der EU als Lebensmittelzusatz nicht zugelassen. Ein wichtiger Aspekt ist in diesem Zusammenhang die Gew?hrleistung einer bestimmten stofflichen Zusammensetzung dieses Naturproduktes. Um externe Faktoren, die suboptimales Wachstum von S. rebaudiana bewirken und ihren endogenen Stoffwechsel beeinflussen, ausschlie?en zu k?nnen, bietet sich die Sprosskultur im Bioreaktor an, zu der in diesem Beitrag n?here Erl?uterungen gegeben werden. Die Stevioside haben durch gute Wasserl?slichkeit und Kompatibilit?t mit verschiedenen organischen S?uren von Obst und Gemüse das Potenzial u. a. im Konditorei-Gewerbe und beim Herstellen von Getr?nken eingesetzt zu werden. Vor dem Einsatz sind aber toxikologische Fragen hinreichend zu prüfen.     

An adaptive learning algorithm for a wavelet neural network

Abstract: An optimal online learning algorithm of a wavelet neural network is proposed. The algorithm provides not only the tuning of synaptic weights in real time, but also the tuning of dilation and translation factors of daughter wavelets. The algorithm has both tracking and smoothing properties, so the wavelet networks trained with this algorithm can be efficiently used for prediction, filtering, compression and classification of various non-stationary noisy signals.     

Interaction of Alpha Synuclein and Microtubule Organization Is Linked to Impaired Neuritic Integrity in Parkinson’s Patient-Derived Neuronal Cells

Parkinson’s disease (PD) is neuropathologically characterized by the loss of dopaminergic neurons and the deposition of aggregated alpha synuclein (aSyn). Mounting evidence suggests that neuritic degeneration precedes neuronal loss in PD. A possible underlying mechanism could be the interference of aSyn with microtubule organization in the neuritic development, as implied by several studies using cell-free model systems. In this study, we investigate the impact of aSyn on microtubule organization in aSyn overexpressing H4 neuroglioma cells and midbrain dopaminergic neuronal cells (mDANs) generated from PD patient-derived human induced pluripotent stem cells (hiPSCs) carrying an aSyn gene duplication (SNCA^Dupl). An unbiased mass spectrometric analysis reveals a preferential binding of aggregated aSyn conformers to a number of microtubule elements. We confirm the interaction of aSyn with beta tubulin III in H4 and hiPSC-derived mDAN cell model systems, and demonstrate a remarkable redistribution of tubulin isoforms from the soluble to insoluble fraction, accompanied by a significantly increased insoluble aSyn level. Concordantly, SNCA^Dupl mDANs show impaired neuritic phenotypes characterized by perturbations in neurite initiation and outgrowth. In summary, our findings suggest a mechanistic pathway, through which aSyn aggregation interferes with microtubule organization and induces neurite impairments.     

Model to predict the viscoelastic response of a semi-crystalline polymer under complex cyclic mechanical loading and unloading conditions

To predict the behaviour of a semi-crystalline polymer under complex cyclic mechanical loading and unloading conditions, a non-linear rheological model, previously developed to predict the viscoelastic behaviour under uniaxial monotonous loading and unloading conditions, was used as a starting point and generalised in three-dimensions (3D). The initial model was created on the assumption that the amorphous phase of the semi-crystalline polymer follows the particular reversible mechanism of viscoelastic deformations. This assumption allowed to model the mechanical behaviour of the semi-crystalline polymer under loading and unloading conditions without changing the parameters at the point when the loading was reversed. The parameters of the 3D generalised model under tension, torsion (shearing) and compression conditions were identified from the fitting of the respective uniaxial mechanical tests. It was demonstrated that the 3D model agreed with the experimental data obtained under complex proportional and non-proportional mechanical loading. It was also demonstrated that the model is able to reproduce more then one loop of the cyclic loading.     

Antioxidant efficacy of potato peels and sugar beet pulp extracts in vegetable oils protection

The antioxidant properties of potato peels and sugar beet pulp, in comparison with synthetic antioxidant, were investigated. The bioactive materials were extracted with methanol and examined for their antioxidant activity under accelerated oxidation conditions, using sunflower and soybean oils as oxidation substrates at different concentrations for 72 h at 70 °C. Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by p-anisidine value and stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. The order of oxidative stability was as follow: TBHQ > potato peels > BHT = sugar beet pulp > BHA. The predominant phenolic compounds identified by thin-layer chromatography in potato peels and sugar beet pulp were chlorogenic and gallic acids. The results of different antioxidant parameters demonstrated that potato peels and sugar beet pulp are potent sources of natural antioxidants that might be explored to prevent oxidation of vegetable oils.     

Effect of Fermentation on Antioxidant Properties of Red Cabbages

The influence of fermentation, natural and inoculated by two types of lactic acid bacteria (Lactobacillus plantarum ATCC 8014 and Lactobacillus acidophilus, NCFM), on antioxidant properties of red cabbages was determined and compared with those of their unfermented counterparts. Fermentation led to increased antioxidant activity, which was measured by using DPPH and TEAC method. Highest antioxidant activity was observed in red cabbages fermented with L. plantarum. The total content of phenolic compounds increased upon natural fermentation and was determined by the Folin–Ciocalteu method. Interestingly, in contrast to natural fermentation, for the red cabbages inoculated with L. plantarum and L. acidophilus, the total amount of phenolics increased slightly until day 7 of fermentation and gradually decreased for longer time of fermentation. Fermentation appears to decrease the level of total anthocyanins for all type of fermentation. Additionally, results of the HPLC analysis indicated the metabolism of phenolic compounds during the fermentation of red cabbages. Thus fermentation offers a tool to further increase the antioxidant potential of red cabbages.