Dirk Lukowsky

5 Questions 19 Answers 0 Followers

Questions related from Dirk Lukowsky

Which substance causes the reddish heartwood of pine, larch and douglas fir?

Condensed tannins, stilbenes, flavonoids - which one of these (or other) substances causes the almost same color of the heartwood of pines, larch and Douglas fir? Most researchers seem to...

04 March 2017 1,890 3 View

Staining the heartwood of Pinus sylvestris - which reaction takes place?

Fast blue B salt, Fast red B Salt and benzidine/NaNO2 all stain the heartwood of Pinus sylvestris dark red. What is the mechanism behind this reaction? What is the target molecule for the...

04 March 2017 8,799 1 View

What is the frequency of occurrence of Hylotrupes bajulus?

Despite of its economic importance little seems to be known about the development of the frequency of Hylotrupes bajulus (European House borer, house longhorn beetle, old house borer). In the...

14 February 2016 4,503 8 View

Why is heartwood of Pinus sylvestris not completely water saturated after 140 years under water?

Piles from the harbor of Hamburg show complete water saturation in the bacterial degraded sapwood but only 50% water saturation in the sound heartwood (mc 90% to 110% - heartwood does not sink in...

18 January 2016 7,083 4 View

Is there a scientific name and description for these structures of failing adhesives?

When joints open while the adhesive is still rather liquid, structures like shown in the pictures can be detected. These structure are very helpful in failure analysis as the prove the rather low...

18 January 2016 1,768 2 View