In Situ Assessment of Structural Timber

In Situ Assessment of Structural Timber
Author: Bohumil Kasal
Publisher: Springer Science & Business Media
Total Pages: 140
Release: 2011-03-10
Genre: Technology & Engineering
ISBN: 9400705603

Wood is one of the most intriguing structural materials and the only one that is truly renewable. Along with stone, wood is the oldest structural material on the planet and has been extensively used throughout human history. Due to its aesthetical value and positive environmental impact, wood has experienced a renaissance in construction. As a biodegradable, hygroscopic, non-isotropic material, wood presents special challenges for a professional and requires through knowledge ranging from biology to continuum mechanics. This state-of-the-art report reflects the current knowledge in the area of in situ assessment of the physical and mechanical properties of wood structures. Nondestructive, semi-destructive and destructive methods are described in a systematic manner where technology, equipment and limitations are discussed. Some of the discussed methods are used in other materials such as masonry and concrete. Most of the methods, however, are specific to wood and special qualifications are required to understand and apply these methods effectively. Existing methods are constantly improved and new methods are being developed. This report includes methods that are used in practice or have shown significant promise and have a body of knowledge that supports statements made in this report. This is a useable tool for professionals, researchers, educators and students

Guide to Biomass comminution: material properties, machinery, principles of the process and fundamentals of process modelling

Guide to Biomass comminution: material properties, machinery, principles of the process and fundamentals of process modelling
Author: Lukasz Niedzwiecki
Publisher: diplom.de
Total Pages: 70
Release: 2013-07-01
Genre: Science
ISBN: 3863419383

This study aims to derive a qualitative model for energy requirements of the wood chipping process. A relationship is shown between energy requirements and properties of biomass, which is a quite variable material.The relationship between comminution machinery and energy which is necessary for the process is highlighted. The derivation of the model is focused on chipping, but it is generally possible to make it available for both different types of biomass (f. ex. agricultural residues)and different types of comminution machinery (f. ex. hammermills) by using different material properties adjusted to the machinery mechanics. The properties which are used in the derivation are meant to be easy to measure. Furthermore, the model is meant to be used as a base for a quantitative model that, thanks to measurements taken from real comminution machinery and thanks to using wood with known properties, could answer two important questions: - Would hypothetical changes in the desired size of output material increase the total system efficiency, taking into consideration the lowest efficiency of the combustion process (e.g., higher amounts of unburned fuel)? - Considering the energy used for the process, how can comminution as an operation in the biofuel supply chain be optimised? Answers for the above questions could highlight new possibilities in terms of further energy savings and a maximising of the energy efficiency of the bioenergy sector. Furthermore, the results could motivate optimized choices of comminution machinery for the biofuel supply chain as well as for other applications. Another important feature of this study is its unique holistic point of view that takes into consideration aspects from the fields of mechanics, material sciences and natural sciences to deliver the full picture to the reader.