Verklebung von wachsimprägnierter Buche unter Variation der Klebesysteme und Durchführung einer Plasmabehandlung

Beech wood was impregnated with two hot melting waxes. Contact angle measurement followed to determine hydrophobizing of such treated wood. Tensile shear tests were carried out to test the adhesion properties with three different glues under varying environmental conditions. Furthermore, wax impregnated beech was subjected to plasma treatment prior to glueing. The results demonstrate that wood treated with polar paraffin shows lower adhesion properties compared to montan wax. Therefore, montan wax was investigated more intensely. Beech impregnated with such wax can be used for constructive building elements in the interior sector. D3 Glues for non-constructive applications were realized by using PVAc and phenol-resorcinol resin under permanent influence of humidity. Plasma treatment improves this quality to obtain D4 glue. Back-drying of the water stored specimens proves the suitability of isocyanate glue and also that of PVAc after plasma treatment for 120 s.     

Emissions from the Polish power industry

Poland is a country where power and heat energy production is based on conventional fuel combustion, above all hard coal and lignite. In power plants and combined heat and power plants, fossil fuel combustion results in emitting to the atmosphere first of all SO₂, NO_x, CO, particulate matter, greenhouse gases for instance N₂O and CO₂. For many years the Polish power industry has tried to reduce the emission of air contaminants to the atmosphere. The reduction is feasible on account of various methods of emission reduction, which have been advanced and applied for many years.

The paper presents conventional fuels used in the Polish professional power industry, as well as the principal emission types occurring there for the last 10 years and the undertaken reduction measures.     

Life satisfaction and self-reported problems after spinal cord injury: Measurement of underlying dimensions.

Objective: Evaluate the utility of the current 7-scale structure of the Life Situation Questionnaire—Revised (LSQ–R) using confirmatory factor analysis (CFA) and explore the factor structure of each set of items. Design: Adults (N = 1,543) with traumatic spinal cord injury (SCI) were administered the 20 satisfaction and 30 problems items from the LSQ–R. Results: CFA suggests that the existing 7-scale structure across the 50 items was within the acceptable range (root-mean-square error of approximation [RMSEA] = 0.078), although it fell just outside of this range for women. Factor analysis revealed 3 satisfaction factors and 6 problems factors. The overall fit of the problems items (RMSEA = 0.070) was superior to that of the satisfaction items (RMSEA = 0.80). RMSEA fell just outside of the acceptable range for Whites and men on the satisfaction scales. All scales had acceptable internal consistency. Conclusion: Results suggest the original scoring of the LSQ–R remains viable, although individual results should be reviewed for special population. Factor analysis of subsets of items allows satisfaction and problems items to be used independently, depending on the study purpose. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The dominance of arginine-containing peptides in MALDI-derived tryptic mass fingerprints of proteins.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful tool for mass finger-printing of peptide mixtures obtained after enzymatic ingel digestion of proteins separated by two-dimensional electrophoresis (2-DE). In the course of a proteome analysis of mycobacteria using mass spectrometric identification, it was found that 94% of the most intense MALDI-MS peaks denote peptides bearing arginine at the C-terminal end. The effect was demonstrated to be equally prominent using an equimolar mixture of the synthetic peptides known to be present in the tryptic digest of the mycobacterial 35 kDa antigen ("synthetic mass map"). In addition, several binary mixtures of synthetic peptides differing exclusively at the C terminus (Arg or Lys) were examined to rationalize the higher sensitivity toward arginine-containing peptides. The extent of the effect described depends on the matrix used and may facilitate a more reliable assignment of mass fingerprint data to protein sequences in databases.     

Emulsion-based fluorosensors for potassium featuring improved stability and signal change

A novel kind of potassium optode is presented which is based on the use of lipophilic droplets containing valinomycin and entrapped in a structured hydrogel. A positively charged solvatochromic dye located near the surface of the droplets responds to the valinomycin-assisted extraction of potassium from the sample by dramatic decrease of fluorescence intensity. The dynamic range is from 5 to 100 mM potassium, with negligible cross sensitivity to ionic strength. Cross sensitivity to pH is negligible too in the pH range from 6.5 to 7.3. The effect of interfering lipophilic anions is discussed. Response times within the dynamic range are less than 3 min on going from low to high potassium ion concentrations but about 10 min in the reverse direction. Response is fully reversible with only small drifts in baseline. The measurement uncertainty of determining 5 mM potassium is better than 0.2 mM.     

A theory of crack nucleation in high strain fatigue

From previous observations of the surfaces of metals cycled in high strain fatigue, the mechanism of crack nucleation is considered a plastic instability phenomenon. A model for crack nucleation based on this conclusion is now developed quantitatively and a simple relationship between the number of cycles to nucleate a crack and the applied, plastic, strain range thus predicted. Since the model is valid for any material capable of plastic deformation, plasticine has been cycled in reversed bending to test its prediction. Cracks were observed to form in the plasticine by puckering of the surface at stress concentrations, in direct confirmation of the model. Moreover, the crack nucleation measurements on the plasticine and data on metals, taken from the literature, are considered to be in reasonable agreement with the prediction of the model.

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Zusammenfassung Ausgelrend von früheren Experimenten an Metalloberflächen, die starken Ermüdungs-verformungen unterworfen wurden, wird die Art der Rissentstehung als ein plastisches Instabilitätsphänomen betrachtet. Ein darauf aufbauendes Modell für die Rissentstehung wird quantitativ entwickelt and eine einfache Beziehung zwischen der Anzahl der zur Rissentstehung führenden Ermüdungsvorgänge and dem angewandten Verformungsbereich angegeben. Da das Modell auf jedes plastisch verformbare Material anwendbar ist, wurde seine Gültigkeit an Plastilin getestet, das periodischen Biegungen unterworfen wurde. Es wurden Risse im Plastilin beobachtet, die sich, entsprechend dem Modell, durch Faltenbildung der Oberfläche bei Stellen erhöhter Spannung ausbildeten. Ausserdern lässt sich feststellen, dass sowohl die Messergebnisse über Rissentstehung an Plastilin als auch die, der Literatur entnommenen, Messergebnisse an Metallen in brauchbarer Übereinstimmung mit den Aussagen des Modells stehen.

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Résumé A partir d'observations précédentes faites sur la surface des métaux soumis à la fatigue oligocyclique, on a déduit que le mécanisme de formation de la fissure relevait d'un phénomène d'instabilité plastique.Sur la base de cette conclusion, on développe à présent quantitativement un modèle de formation de la fissure, ce qui permet de prédire use relation simple entte le sombre de cycles nécessaires pour amorcer une fissure et l'écart de déformation plastique appliquée par cycle.Le modèle étant appliquable à tout materiau susceptible de déformation plastiques, on a soumis à flexion alternée de la plasticise afin d'en vérifier les prédictions.On a observé que, pour ce matériau, les fissures prenaient naissance par un processus de plissement de la surface aux endroits de concentration de tension, ce qui confirme directement le modèle proposé. En outre, les mesures de formation des fissures dans la plasticise ont été comparées aux données existantes dans la littérature, et qui se refèrent aux métaux.Cette comparaison prêche en faveur d'une concommitence raisonnable des observations expérimentales et des prédictions du modèle.