This paper provides a review on the use of acoustics to measure stiffness of standing trees, stems, and logs. An outline is given of the properties of wood and how these are related to stiffness and acoustic velocity throughout the tree. Factors are described that influence the speed of sound in wood, including the different types of acoustic waves which propagate in tree stems and lumber. Acoustic tools and techniques that have been used to measure the stiffness of wood are reviewed. The reasons for a systematic difference between direct and acoustic measurements of stiffness for standing trees, and methods for correction, are discussed. Other techniques, which have been used in addition to acoustics to try to improve stiffness measurements, are also briefly described. Also reviewed are studies which have used acoustic tools to investigate factors that influence the stiffness of trees. These factors include different silvicultural practices, geographic and environmental conditions, and genetics.

The Southern Alps Experiment is being mounted to study the influence of New Zealand's Southern Alps on local weather and climate. This paper describes these alpine influences and outlines proposed field and modeling experiments. Experiment goals include understanding and quantifying factors that govern the intensity and spatial distribution of heavy rainfall, the west to east distribution of precipitation across the mountains, and the intensity of lee wind storms and warming. Linked research will explore the use of deterministic rainfall models to predict river flows from mountain watersheds.

Since Vindeby in 1991, more than 100 projects have been installed in Europe, and will need decommissioning one day. Despite the increasing number of projects reaching this phase, decommissioning is still an area that has received relatively little attention. This paper considers the practicalities and economic implications of recycling offshore wind components as part of an end of life strategy. There is no existing source that gathers together materials data for currently operational wind turbines in Europe relevant to recycling. Since this information is necessary for any economic analysis of component recycling, such a dataset was generated. The results illustrate the specific wind turbine materials suitable for recycling, expressed in percentage values of the wind turbine's total mass. An economic analysis is then performed to study how recovering these materials and selling them as scrap metal can impact the decommissioning costs. As concluding remarks, recycling offshore wind components could pay for nearly 20% of the total wind farm decommissioning costs if monopile foundations are considered. Furthermore, the volatility of scrap prices is such that this could even help define when it would be best to decommission an offshore wind farm. COVER LETTERThank you very much for considering our article. It has a lot of effort with diverse expertise from people with different backgrounds. It is a topic that is currently receiving a lot of attention and causing concerns, and is the first outcome of a wider research we are producing.We are proud of submitting it to Energy Policy as we consider this journal is ideal for generating the corresponding concerns and in consequence, enable a transition to a potential improvement and make this end of life stage, more sustainable. Cover LetterTitle page HIGHLIGHTS  Uncertainties in end of life strategies of offshore wind projects make decisions complex and challenging  An inevitable decommissioning era is arriving which must adequate to project's characteristics  Recycling should be included as a target and taken into consideration since the planning  An appropriate recycling could pay part of the decommissioning costs while making the process more sustainable  The volatility of scrap value can help determine when it is best to decommission *Highlights Response to Reviewers1 ABSTRACT Since Vindeby in 1991, more than 100 projects have been installed in Europe, and will need decommissioning one day. Despite the increasing number of projects reaching this phase, decommissioning is still an area that has received relatively little attention.This paper considers the practicalities and economic implications of recycling offshore wind components as part of an end of life strategy. There is no existing source that gathers together materials data for currently operational wind turbines in Europe relevant to recycling. Since this information is necessary for any economic analysis of component recycling, such a dataset was generated.The results illustrate the specific wind turbine...

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