Wood : From Natural Color Patterns Toward Naturally Altered Color Impressions

Natural wood colors occur within a wide range from almost white (e.g., white poplar), various yellowish, reddish, and brownish hues to almost black (e.g., ebony). The intrinsic color of wood is basically defined by its chemical composition. However, other factors such as specific anatomical formations or physical properties further affect the optical impression. Starting with the chemical composition of wood and anatomical basics, wood color and its modifications are discussed in this chapter. The classic method of coloring or re-coloring wood-based material surfaces is the application of a coating containing appropriate dyes or pigments. Different concepts for wood coating and coloration are presented. Another method used dyes for coloration of the wood structure. As alternative techniques, physical methods, for example, drying, steaming, ammoniation, bleaching, enzyme treatment, as well as treatment with electromagnetic irradiation (e.g., UV), are explained in this chapter

A comparison of relevant data and results from single pellet press research is Mission Impossible : A review

A global increase in the wood fuel pellet market requires knowledge of new biomasses pelleting abilities. As large-scale industrial tests of new materials are costly, tests in e.g., a single pellet press (SPP) are desirable. SPPs have many different configurations and it typically produces one pellet at a time and can give results of its pelletability. This review has surveyed the research that has been carried out of SPPs to ascertain the feasibility of comparing their obtained data and the results. The results show that it is almost impossible to compare the data and results of the various different SPP studies, e.g., some information from the data used was missing, resulting in that only 27 out of 70 papers were comparable. One solution could be the introduction of a common SPP testing method using a determined set of data that enables a reference pellet to be produced in every study.cited By 0</p

Recent human-induced atmospheric drying across Europe unprecedented in the last 400 years

International audienc

Atmospheric drying across Europe is unprecedented in a pre-industrial context

Vapour pressure deficit (VPD) represents the desiccation strength of the atmosphere, fundamentally impacting evapotranspiration, ecosystem functioning and vegetation productivity. Its spatial patterns and long-term changes under natural versus human-induced climate change are poorly understood but are essential for predicting its future ecological and socio-economic effects, e.g., on crop yield, bioclimatic comfort or wildfires. We combine regional reconstructions of pre-industrial summer VPD variability from a European tree-ring oxygen-isotope network with excellent climate sensitivity with observations and Earth System Model simulations. We demonstrate a recent human-induced intensification of atmospheric drying across Europe that exceeds natural variability specifically in the Alps and Pyrenees, but also in western, central and southern Europe. A less distinct increase occurs in Fennoscandia. This VPD increase may cause an enhanced risk of tree mortality, forest decline and yield reductionsevenin the temperate lowland regions of Europe, particularly when considering the extreme drought events in the recent years