Untersuchungen zur Verteilung des Klebstoffes im Bereich der Leimfuge mittels Neutronenradiographie und Mikroskopie

Zusammenfassung: Mittels mikroskopischer Betrachtung von angefärbten Dünnschnitten, Rasterelektronenmikroskopie sowie Neutronenradiographie wurde vergleichend das Eindringverhalten von Harnstoff-Formaldehydharz, Dispersionsklebstoff (PVA) und Polyurethan untersucht. Es konnten deutliche Unterschiede im Eindringverhalten der Klebstoffe nachgewiesen werden. Bei Harnstoffharz trat unter den gewählten Verklebungsbedingungen ein stärkeres Eindringen des Klebstoffes in das Holz auf. Mittels Neutronenradiographie konnte eine Quantifizierung der Leimverteilung erzielt werden. Mit dieser Methode gelang es, das Eindringen des Leimes sichtbar zu machen, und Leimfuge und Holz zu trennen. Es sind deutliche Unterschiede im Bereich Frühholz-Spätholz erkennba

CBR in Dependency-based Machine Translation

A case based reasoning approach is introduced as a learning technique in the domain of machine translation of natural language. In our approach syntactical and semantic features are part of the cases in the case-base. To implement this, dependency analysers of sentences in the source and target languages are used. The case-base is filled with a learning mechanism that uses a parallel corpus of sentences with their translations. This case-base is used to make new translations

Bacteria Hunt: A multimodal, multiparadigm BCI game

Brain-Computer Interfaces (BCIs) allow users to control applications by brain activity. Among their possible applications for non-disabled people, games are promising candidates. BCIs can enrich game play by the mental and affective state information they contain. During the eNTERFACE’09 workshop we developed the Bacteria Hunt game which can be played by keyboard and BCI, using SSVEP and relative alpha power. We conducted experiments in order to investigate what difference positive vs. negative neurofeedback would have on subjects’ relaxation states and how well the different BCI paradigms can be used together. We observed no significant difference in mean alpha band power, thus relaxation, and in user experience between the games applying positive and negative feedback. We also found that alpha power before SSVEP stimulation was significantly higher than alpha power during SSVEP stimulation indicating that there is some interference between the two BCI paradigms

Bayesian graphical models for regression on multiple data sets with different variables

Routinely collected administrative data sets, such as national registers, aim to collect information on a limited number of variables for the whole population. In contrast, survey and cohort studies contain more detailed data from a sample of the population. This paper describes Bayesian graphical models for fitting a common regression model to a combination of data sets with different sets of covariates. The methods are applied to a study of low birth weight and air pollution in England and Wales using a combination of register, survey, and small-area aggregate data. We discuss issues such as multiple imputation of confounding variables missing in one data set, survey selection bias, and appropriate propagation of information between model components. From the register data, there appears to be an association between low birth weight and environmental exposure to NO2, but after adjusting for confounding by ethnicity and maternal smoking by combining the register and survey data under our models, we find there is no significant association. However, NO2 was associated with a small but significant reduction in birth weight, modeled as a continuous variable

Water vapour diffusion through historically relevant glutin-based wood adhesives with sorption measurements and neutron radiography

In this work, the sorption and moisture diffusion behaviour of historically relevant glutin-based adhesives (i.e. bone glue, hide glue, fish glue) is characterized. The adhesive's sorption isotherms were assessed on thin film samples revealing fundamental differences between the glutin-based adhesives and the synthetic reference adhesive (polyurethane). Furthermore, the water vapour diffusion parallel to the fibre was examined by means of neutron imaging on bonded two-layer samples of Norway spruce wood. In contrast to previous studies using neutron imaging, a new evaluation approach is presented, which allows for nonzero initial moisture conditions and takes into account and compensates for the geometry changes in the sample caused by swelling and shrinkage, thus allowing for a characterization of the diffusion behaviour within the glue line. The diffusion coefficients determined with neutron imaging were interpreted in terms of a theoretical model which takes into account the glue line microstructure. Although the diffusion coefficients were on average larger values for the glutin-based adhesives compared to the reference polyurethane adhesive, the significant variation observed in the sorption measurement is not reflected. This can partially be ascribed to excessive penetration of the adhesives into the wood substrate in fibre direction, which impedes a continuous adhesive layer. Furthermore, deformation and densification of the wood structure was assessed in the vicinity of the adhesive joint. This effect can be ascribed to the surface roughness, which results in very high local stresses leading to buckling and deformation of the tracheids. This situation is similar to that found for adhesive joints in or close to the fibre direction such as finger or butt joints

Combined neutron and x-ray tomography—a versatile and non-destructive tool in planetary geosciences

With several upcoming sample return missions, such as the Mars Sample Return Campaign, non-destructive methods will be key to maximizing their scientific output. In this study, we demonstrate that the combination of neutron and X-ray tomography provides an important tool for the characterization of such valuable samples. These methods allow quantitative analyses of internal sample features and also provide a guide for further destructive analyses with little to no sample treatment, which maintains sample integrity, including minimizing the risk of potential contamination. Here, we present and review the results from four case studies of terrestrial impactites and meteorites along with their analytical setup. Using combined X-ray and neutron tomography, a Ni-Fe silicide spherule, that is, projectile material, was located within a Libyan Desert Glass sample and the distribution of hydrous phases was pinpointed in selected impactite samples from the Chicxulub IODP-ICDP Expedition 364 drill core and the Luizi impact structure, as well as in the Miller Range 03346 Martian meteorite

A systems approach for discovering linoleic acid derivatives that potentially mediate pain and itch

Chronic pain and itch are common hypersensitivity syndromes that are affected by endogenous mediators. We applied a systems-based, translational approach to predict, discover, and characterize mediators of pain and itch that are regulated by diet and inflammation. Profiling of tissue-specific precursor abundance and biosynthetic gene expression predicted that inflamed skin would be abundant in four previously unknown 11-hydroxy-epoxy- or 11-keto-epoxy-octadecenoate linoleic acid derivatives and four previously identified 9- or 13-hydroxy-epoxy- or 9- or 13-keto-epoxy-octadecenoate linoleic acid derivatives. All of these mediators were confirmed to be abundant in rat and human skin by mass spectrometry. However, only the two 11-hydroxy-epoxy-octadecenoates sensitized rat dorsal root ganglion neurons to release more calcitonin gene-related peptide (CGRP), which is involved in pain transmission, in response to low pH (which mimics an inflammatory state) or capsaicin (which activates ion channels involved in nociception). The two 11-hydroxy-epoxy-octadecenoates share a 3-hydroxy-Z-pentenyl-E-epoxide moiety, thus suggesting that this substructure could mediate nociceptor sensitization. In rats, intradermal hind paw injection of 11-hydroxy-12,13-trans-epoxy-(9Z)-octadecenoate elicited C-fiber-mediated sensitivity to thermal pain. In a randomized trial testing adjunctive strategies to manage refractory chronic headaches, reducing the dietary intake of linoleic acid was associated with decreases in plasma 11-hydroxy-12,13-trans-epoxy-(9Z)-octadecenoate, which correlated with clinical pain reduction. Human psoriatic skin had 30-fold higher 9-keto-12,13-trans-epoxy-(10E)-octadecenoate compared to control skin, and intradermal injection of this compound induced itch-related scratching behavior in mice. Collectively, these findings define a family of endogenous mediators with potential roles in pain and itch