Comparison of several wood smoke markers and source apportionment methods for wood burning particulate mass

Residential wood combustion has only recently been recognized as a major contributor to air pollution in Switzerland and in other European countries. A source apportionment method using the aethalometer light absorption parameters was applied to five winter campaigns at three sites in Switzerland: a village with high wood combustion activity in winter, an urban background site and a highway site. The particulate mass from traffic (PMtraffic) and wood burning (PMwb) emissions obtained with this model compared fairly well with results from the 14C source apportionment method. PMwb from the model was also compared to well known wood smoke markers such as anhydrosugars (levoglucosan and mannosan) and fine mode potassium, as well as to a marker recently suggested from the Aerodyne aerosol mass spectrometer (mass fragment m/z 60). Additionally the anhydrosugars were compared to the 14C results and were shown to be comparable to literature values from wood burning emission studies using different types of wood (hardwood, softwood). The levoglucosan to PMwb ratios varied much more strongly between the different campaigns (4–13%) compared to mannosan to PMwb with a range of 1–1.5%. Possible uncertainty aspects for the various methods and markers are discussed.

Otium et negotium. Reading processes and their cultural backgrounds in early Italian and German humanism

Reading and reading habits have radically changed in the digital age. Readers are no longer physically bound to textual objects and libraries, they deal with texts by copying, altering, and annotating them, and they mix established textual forms with other semiotic systems such as pictograms, icons and images. These circumstances also provoke a renewed research interest in the history of reading. In this talk, I will concentrate on reading processes as to how they were enacted and practised in early Italian and German humanism. I will start with some paradigmatic scenes described in Petrarch’s letters (among others the famous visit of the Mont Ventoux, where Petrarch, after having enjoyed a spectacular panorama, withdraws into the contemplative reading of St-Augustine). The transmission of Petrarch’s writings in humanist circles of Southern Germany (e.g. with the Schedel and Gossembrot families in Nurnberg, Augsburg and Strasburg) will then lead to specific reading practices documented in manuscripts that once belonged to coherent libraries and are nowadays spread all over Europe. In the case of the former tradesman and mayor Sigismund Gossembrot, complex habits of textual annotating and cross-referencing can be observed. The dichotomy of the Latin terms otium (‘rest’ and ‘leisure’) and negotium (‘activity’, but also ‘practice’, ‘negotiation’, ‘circulation of social energy’ in the sense of New Historicism) will be used as an ideal-type outline to describe the occurring processes of reading.

Otium et negotium. Reading processes and their cultural backgrounds in early Italian and German humanism

Reading and reading habits have radically changed in the digital age. Readers are no longer physically bound to textual objects and libraries, they deal with texts by copying, altering, and annotating them, and they mix established textual forms with other semiotic systems such as pictograms, icons and images. These circumstances also provoke a renewed research interest in the history of reading. In this talk, I will concentrate on reading processes as to how they were enacted and practised in early Italian and German humanism. I will start with some paradigmatic scenes described in Petrarch’s letters (among others the famous visit of the Mont Ventoux, where Petrarch, after having enjoyed a spectacular panorama, withdraws into the contemplative reading of St-Augustine). The transmission of Petrarch’s writings in humanist circles of Southern Germany (e.g. with the Schedel and Gossembrot families in Nurnberg, Augsburg and Strasburg) will then lead to specific reading practices documented in manuscripts that once belonged to coherent libraries and are nowadays spread all over Europe. In the case of the former tradesman and mayor Sigismund Gossembrot, complex habits of textual annotating and cross-referencing can be observed. The dichotomy of the Latin terms otium (‘rest’ and ‘leisure’) and negotium (‘activity’, but also ‘practice’, ‘negotiation’, ‘circulation of social energy’ in the sense of New Historicism) will be used as an ideal-type outline to describe the occurring processes of reading.

Long-distance spore dispersal in wood-inhabiting Basidiomycetes

Eight species of wood-inhabiting basidiomycetes (Laurilia sulcata, Peniophora aurantiaca, Resinicium bicolor, Scytinostroma galactinum, Terana caerulea, Trichaptum abietinum, T. biforme and T. fuscoviolaceum) were used in a spore-trapping test to evaluate their individual ability for long-distance spore dispersal. Petri dishes with single spore mycelia were used as baits. In the experiment, carried out at the Botanical Institute in Göteborg, spores from the air were regularly captured. Surprisingly, spores were captured from species whose nearest known natural occurrence was located quite far from Göteborg. The closest population of Peniophora aurantiaca is about 1000 km south of Göteborg. The results from this experiment support the hypothesis that fungal spores are widely and efficiently dispersed. Such a broad and extensive dispersal ability is of vital importance, especially for wood-inhabiting species which are highly dependent on a substrate which is onlv temporarily available.

Study of Basic Wood Decay Mechanisms and Their Biotechnological Applications

The overall objective of this thesis was to gain further understanding of the non-enzymatic mechanisms involved in brown-rot wood decay, especially the role of pH, oxalic acid, and low molecular catecholate compounds on the dissolution and reduction of iron, and the formation of reactive oxygen species. Another focus of this study will be the potential application of a biomimetic free radical generating system inspired from fungi wood decay process, especially the non-enzymatic mechanism. The possible pathways of iron uptake and iron redox cycling in non-enzymatic brown-rot decay were investigated in this study. UV-Vis spectroscopy and HPLC were employed to study the kinetics and pathways of the interaction between iron and model catecholate compounds under different pH and chelator/iron molar ratio conditions. Iron chelation and reduction during early non-enzymatic wood decay processes have been studied in this thesis. The results indicate that the effects of the chelator/iron ratio, the pH, and other reaction parameters on the hydroxyl radical generation in a Fenton type system can be determined using ESR spin-trapping techniques. Data also support the hypothesis that superoxide radicals are involved in chelator-mediated Fenton processes. The mechanisms involved in free radical activation of Thermal Mechanical Pulp fibers were investigated. The activation of TMP fibers was evaluated by ESR measurement of free phenoxy radical generation on solid fibers. The results indicate that low molecular weight chelators can improve Fenton reactions, thus in turn stimulating the free radical activation of TMP fibers. A mediated Fenton system was evaluated for decolorization of several types of dyes. The result shows that the Fenton system mediated by a catecholate-type chelator effectively reduced the color of a diluted solution of synthetic dyes after 90 minutes of treatment at room temperature. The results show that compared to a neat Fenton process, the mediated Fenton decolorization process increased the production, and therefore the effective longevity, of hydroxyl radical species to increase the decolorization efficiency.

Église Saint-Julien-le-Pauvre. Un Pilier d'une Colonne de la Nef, considéré comme un Chef-d'oeuvre de Sculpture

Signatur des Originals: S 36/F08028

Église Saint-Julien-le-Pauvre. Un pilier d'une Colonne de la Nef considéré comme un chef-d'oeuvre de sculpture, Paris

Signatur des Originals: S 36/F08031

Ma... Wood, Rollenbild, Kniestück

Signatur des Originals: S 36/F10299

Henry Joseph Wood, Brustbild

Signatur des Originals: S 36/F11937

Olga Wood, Kniestück

Signatur des Originals: S 36/F11938

Olga Wood, Brustbild

Signatur des Originals: S 36/F11939