Measurement methodology for greenhouse gas emissions from storage of forest chips–A review

Abstract Research on greenhouse gas emission related to solid biofuels has focused mainly on the emissions from end use and the production chain. GHG emissions from the storage of forest chips have not received much attention in recent literature. In order for EU emission reduction targets to be fully understood, emissions from solid biofuel storage needs to be better described. Usually emissions from chip piles have been modelled using studies from organic waste composting but these two materials can differ appreciably; for example the C/N-ratio and moisture content. Herein, previous studies on greenhouse gas emissions from forest chips piles during storage are reviewed. The objective is t…

Using Wave Propagation Simulations and Convolutional Neural Networks to Retrieve Thin Film Thickness from Hyperspectral Images

Ill-posed inversion problems are one of the major challenges when there is a need to combine measurements with the theory and numerical model. In this study, we demonstrate the use of wave propagation simulations to train a convolutional neural network (CNN) for retrieving sub-wavelength thickness profiles of thin film coatings from hyperspectral images. The simulations are produced by solving numerically one-dimensional wave equation with a method based on Discrete Exterior Calculus (DEC). This approach provides a powerful tool to produce large sets of training data for the neural network. CNN was verified by simulated verification sets and measured reflectance spectra, both of which showe…

Kestävän bioenergiatulevaisuuden rakentaminen : Osa 3, Keski-Suomen bioenergiakoulutuksen kehittäminen bioenergiakoulutuksen resurssit

From wood pellets to wood chips, risks of degradation and emissions from the storage of woody biomass – A short review

Abstract The compounds in stored woody biomass degrade as a result of chemical and/or biological processes during storage. These processes produce gaseous emissions. Recent studies concerning gaseous emissions from wood pellet storages are reviewed herein. The applicability of the results from pellet research to wood chips is discussed. Thorough scientific understanding on the storage phenomena of wood chips is extremely important as the threat of climate change and the need to reduce greenhouse gas emissions have led to an increased need to large scale wood chip storage to ensure supply. Typically the gases produced from stored woody biomasses are carbon monoxide (CO), carbon dioxide (CO 2…