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Effects of particle size on minimum ignition temperature of dust layers and dust clouds of selected wood dusts

100%

Jaskolkowski W., Ptak S., Laskowski A., Zakrzewska G.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 86

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Comparative studies of ipe (Tabebuia spp.) wood photodegradation cause by treatment with outdoor and indoor UV-A light irradation

80%

Zborowska M., Stachowiak-Wencek A., Waliszewska B., Pradzynski W.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 88

Comparative studies of ipe (Tabebuia spp.) wood photodegradation cause by treatment with outdoor and indoor UV-A light irradiation. A study on photodegradation of ipe (Tabebuia spp.) wood by UV A light has been carried out. Two types of lamps were used in the tests, i.e. a UVA-340 lamp with a wavelength of 290 - 400 nm, emitting light resembling natural light, an a UVA-351 lamp with a wavelength of 300 - 400 nm, imitating light found indoors penetrating through window panes. Colour of the samples was measured using a Datacolour 600 spectrophotometer prior and after 1,5, 10, 25, 50 and 100-hour irradiation. Characterization of investigated material included determination of its chemical components. Despite the fact that ipe wood contains high concentrations of components playing an important role in the photodegradation process (e.g. 37.2% lignin) the detected changes are minor and do not exceed 1 point. The change in colour (∆E) for ipe wood surface was mainly caused by changes in the chromatic coordinate (b*) and the lightness coordinate (L*). Greater changes occurred under the influence of a UV-340 lamp emitting the type of light resembling that found outdoors.

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Comparative studies of ipe (Tabebuia spp.) wood photodegradation caused by treatment with acid and alkaline buffers

80%

Zborowska M., Stachowiak-Wencek A., Waliszewska B., Pradzynski W.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 88

Comparative studies of ipe (Tabebuia spp.) wood photodegradation caused by treatment with acid and alkaline buffers. A study on photodegradation of ipe wood using xenon lamp and UV lamp light has been carried out. Colour of the samples was measured using a Datacolour 600 spectrophotometer prior to their soaking in acid and alkaline buffers, after soaking and successively after 1, 5, 10, 25, 50 and 100-hour irradiation. It was concluded that the treatment with acid and alkaline buffers causes opposite changes of the investigated colour coordinates. Samples after treatment with the acid buffer were lighter and yellower in colour, but less red, while after treatment with the alkaline buffer they were darker and redder, bur less yellow. Generally treatment with the alkaline buffer caused more significant changes of ipe wood in comparison to treatment with the acid buffer. Samples treated with the acid buffer were more prone to changes of colour (∆E*) due to light irradiation in comparison to the samples treated with the alkaline buffer. More significant changes of colour were observed in the case of UV irradiation in comparison to irradiation cause by xenon lamp light.

Ograniczanie wyników

3 Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

2 Pradzynski W.

2 Stachowiak-Wencek A.

2 Waliszewska B.

2 Zborowska M.

1 Jaskolkowski W.

1 Laskowski A.

1 Ptak S.

1 Zakrzewska G.

3 2014

Effects of particle size on minimum ignition temperature of dust layers and dust clouds of selected wood dusts

Comparative studies of ipe (Tabebuia spp.) wood photodegradation cause by treatment with outdoor and indoor UV-A light irradation

Comparative studies of ipe (Tabebuia spp.) wood photodegradation caused by treatment with acid and alkaline buffers