Treesearch

In the present paper we focus on demonstrating the use of design optimization for the constitutive characterization of anisotropic material systems such as polymer matrix composites, with or without damage. All approaches are based on the availability of experimental data originating from mechatronic material testing systems that can expose specimens to multidimensional loading paths and can automate the acquisition of data representing the excitation and response behavior of the specimens involved. Material characterization is achieved by minimizing the difference between experimentally...

Although zebra mussels (Dreissena polymorpha) initially colonized shallow habitats within the North American Great Lakes, quagga mussels (Dreissena bugensis) are becoming dominant in both shallow- and deep-water habitats. Shell morphology differs among zebra, shallow quagga and deep quagga mussels but functional consequences of such differences are unknown. We examined effects of shell morphology on locomotion for the three morphotypes on hard (typical of shallow habitats) and soft (characteristic of deep habitats) sedimentary substrates. We quantified morphology using the polar moment of...

How do you measure the surface area of a threaded fastener? How much coating would you put on it? How thick of a coating? what about non-threaded fasteners?

Acoustic technologies have been well established as material evaluation tools in the past several decades, and their use has become widely accepted in the forest products industry for on-line quality control and products grading. Recent research developments on acoustic sensing technology offer further opportunities to evaluate standing trees and logs for general wood quality and intrinsic wood properties. Although the concept of using acoustic velocity as an effective measure of stiffness applies to both standing trees and felled logs, the method typically used to measure acoustic...

Previous research has proved the concept of acoustic wave propagation methods for evaluating wood quality of trees and logs during forest operations. As commercial acoustic equipment is implemented in field for various purposes, one has to consider the influence of operating temperature on acoustic velocity — a key parameter for wood property prediction. Our field study on acoustic monitoring of standing trees and logs over one-year cycle showed a significant change in acoustic velocity as seasonal temperature changed. The purpose of this study is to further investigate the effects of...

The single most difficult physical skill involved in wood identification is producing a smoothly prepared surface for observing anatomical features. This skill must be practiced patiently; it takes time to become proficient at this task. Producing a cleanly cut surface is also the only appreciably dangerous aspect of wood identification with a hand lens; the tools used to cut the wood are necessarily sharp, and injuries from minor cuts to major lacerations can result from carelessness, fatigue, or poor technique. Safety must always be the first priority, followed closely by the secondary...

The characters presented in this chapter represent the minimal set of terms and concepts necessary to build skill and proficiency in wood identification with a hand lens. This list is not exhaustive, nor is it in complete agreement with the characters used by other authors, in other references, or in traditional microscopic wood anatomy.

The key is written to guide you through the identification process in the most efficient and accurate way possible. It presents you with a numbered series of questions and asks you to answer them. The answers you provide will be based on your interpretations of the anatomical characters in your unknown specimen and will lead you to a new set of questions. Each time you answer a question and proceed to the next you are one step closer to making an identification. Eventually, the key will direct you to a species description page in Chapter 7 that will provide more detailed information about...

These pages are written to be the final step in the identification process; you will be directed to them by the key in Chapter 6. Each species or group of similar species in the same genus has its own set of pages. The information in the first page describes the characteristics of the wood covered in the manual. The page shows images of similar or confusable woods, and notes characteristics that differ between the wood in the manual and those other woods. Determine which character is present in the unknown, and use that information to confirm or deny the identification.

This manual has described the theory of identification (Chapter 1), the botanical basis of wood structure (Chapter 2), the use of a hand lens (Chapter 3), how to use cutting tools to prepare wood for observation with a lens (Chapter 4), and the characters used in hand lens wood identification (Chapter 5) before leading you through an identification key (Chapter 6) and species description pages (Chapter 7). I hope that by this point you have developed a greater understanding of the principles and practice of field wood identification. Having spent considerable time and effort learning the...