Treesearch

Increasing environmental regulations have limited the use of certain broad spectrum synthetic pesticides as wood preservatives creating a need for more environmentally benign wood preservative systems. Biocidal compounds from natural products have been proposed as alternatives to commercial wood preservatives, but field data from long term performance testing is lacking. To investigate long term performance of wood extractives, stakes and blocks of southern pine (SP) and cottonwood (CW) were treated with heartwood extractives of four durable wood species commonly used in Pakistan. Treated...

Cementitious materials cover a very broad area of industries/products (buildings, streets and highways, water and waste management, and many others; see Fig. 20.1). Annual production of cements is on the order of 4 billion metric tons [2]. In general these industries want stronger, cheaper, more durable concrete, with faster setting times, faster rates of strength gain, and there is growing interest in advancing sustainability [3]. To achieve these improvements in properties, there are a wide range of additives such as supplementary cementitious materials (SCMs) [4], chemical admixtures...

Composition of the southern pine forest is now predominated by two species, loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.), owing to fire suppression activities, natural regeneration on abandoned agricultural lands, and extensive planting. Comparison of the wood and bark physical properties of these pines is of interest in terms of the yields of usable biomass and, for the bark, its ecological functionality on a living tree. Trees from a species comparison study were used to generate wood and bark property data, on a whole-tree basis, and for stem disks collected...

Economic analysis was conducted on the feasibility of operating a small-sized (500kW/hour) gasification power plant producing heat and electricity in a rural town surrounded by forests in the Republic of Korea. Cost factors that were considered over the plant’s 20-year life included wood procurement, a wood grab loader, a chipper, a chip dryer, a gasifier, a generator, land and building, wages, and office management. All the cost factors were calculated based on the 2016 market values for logs, information from machine manufacturers, and a literature review. Revenues were estimated from...

This literature review aims to provide a systematic analysis of studies on the financial aspects of producing torrefied biomass and torrefied pellets. There are substantial differences in the specific technologies, operating conditions, scale of the demonstration, and properties of biomass feedstock. There is a lack of reports that consider the entire supply chain, which is required for an understanding of the high-cost steps. To obtain a robust view of the torrefaction processes’ financial prospects the authors have used both peer-reviewed and non-peer-reviewed papers that allowed the...

ITS2+trnH-psbA was the best combination of DNA barcode to resolve the Dalbergia wood species studied. We demonstrate the feasibility of building a DNA barcode reference database using xylarium wood specimens.

Hardwoods are a class of tree that holds multiple types of extractives, some of which have their own specialized biological activity. Characterizing these compounds in greater depth can help virologists understand how natural chemicals are able to resist infection, leading to pharmaceutical uses. Hardwoods are known to contain high concentrations of different phenolic compounds which exhibit anti-microbial properties. Liquid-liquid fractionation was used to separate extracts with the same polar characteristics in different solvents. GC/MS spectra showed Black Locust, Catalpa, & Honey...

Softwoods, more specifically Cedars, are a set of tree species known to have extractive components with many different biological activities. Research has shown that certain compounds in Cedars are able to resist various forms of attack (microbial, fungal, insect, etc.). Juniperus virginiana (Eastern Red Cedar, Cupressus/Chamacyparis nootkatensis (Alaskan Yellow Cedar, & Thuja plicata (Western Red Cedar) are commonly studied. Eastern Red is ranked highest above Western Red and Alaskan Yellow in durability, which is a measure of the wood’s resistance to attack. Cedars in particular often...

Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when produced exist as aqueous suspensions at very low concentrations. Analysis of these suspensions by Raman spectroscopy is especially rewarding in that the CNs can be analyzed in the native hydrated state without special considerat...

ASHRAE Standard 160, Criteria for Moisture-Control Design Analysis in Buildings, was published in 2009. The standard sets criteria for moisture design loads, hygrothermal analysis methods, and satisfactory moisture performance of the building envelope. One of the evaluation criteria specifies conditions necessary to avoid mold growth. The current standard requires that the 30-day running average relative humidity at the material surface be less than 80 % when the 30-day running average surface temperature is between 5°C (41°F) and 40°C (104°F). This criterion was intended to strike a...