Treesearch

This paper is a review of published studies involving the use of ground penetrating radar (GPR) on wood structures. It also contains background information to help the reader understand how GPR functions. The use of GPR on wood structures began to grow in popularity at the turn of the millennium. GPR has many characteristics that make it attractive as an inspection tool for wood: it is faster than many acoustic and stress wave techniques; it does not require the use of a couplant; while it can also detect the presence of moisture. Moisture detection is of prime concern, and several...

Southern yellow pine (SYP) is one of the most used softwood species in the world. Most of this raw material come from fast-grown plantation trees. It is of interest to determine if SYP clear wood properties may have changed over the long term, in particular whether such properties may have declined. Herein, specific gravity (SG), ultimate compression strength parallel to grain (UCS||), and UCS perpendicular to grain (UCS⊥) from three samples were compared: Sample 1 tested in 2014; Sample 2 from molding and millwork producers tested in 2017–2019; and Sample 3 from a study conducted in the...

Sorption isotherm models are frequently used to understand the interactions of water with cellulosic materials. Many commonly used models, such as the Guggenheim-Anderson-de Boer, Hailwood-Horrobin, and Dent isotherm models, are based on idealized physical systems. In the scientific literature, these models are often used to predict properties of wood such as the monolayer capacity, which is a representation of the number of available sorption sites in the material. Reporting such properties assumes that an idealized system adequately represents actual wood-water interactions. These models...

In this work, water-soluble polymers were screened through solution casting and polyvinyl alcohol (PVA) and poly(2-ethyl-2-oxazoline) (PEOX) were found as reinforcement agents for cellulose nanofibril (CNF) films. Mechanical property increases of 99% in elastic modulus, 93% in the ultimate tensile strength (UTS) and 134% in the work of failure (WOF) were reported for TEMPO-oxidized cellulose nanofibrils (TOCNFs) with 0.44 mmol/g carboxylate groups and 15 wt% PVA. PEOX had a higher elastic modulus increase of 113%, yet lower UTS and WOF increases were found at 63% and 28%, respectively....

When discussing structural southern yellow pine lumber, questions frequently are asked regarding changes over time. This is a significant area of discussion given that structural lumber properties (i.e., design values) were changed around 2012. Climate change, forest management, genetics, processing, and others are listed among the many possible contributing factors. Of interest are these questions: (1) Are changes in bending properties permanent at some fundamental level, or are they somewhat dynamic and responsive to controllable factors? (2) To what degree have the basic southern pine...

The interrelationships among specific gravity (SG), modulus of elasticity (MOE), and strength (modulus of rupture, MOR) are largely the foundational basis for non-destructive evaluation and testing. Resource monitoring and commercial structural lumber production often rely upon such non-destructive evaluation to predict the bending and/or tension strength of individual members. These technologies require routine calibration. In addition, it is important to know the extent to which a given resource may change over time. To that end, this study investigated the relationship among SG, MOE,...

Indigenous communities in the Pacific West of North America have long depended on fire to steward their environments, and they are increasingly asserting the importance of cultural burning to achieve goals for ecological and social restoration. We synthesized literature regarding objectives and effects of cultural burning in this region within an ecosystem services framework. Much scholarly literature focuses on why various species harvested from burned areas were important historically, while tribes and recent research increasingly stress a wide range of ecological and cultural benefits...

Climate, a primary driver for fire activity, is important for fire management. Climate information is necessary for understanding and predicting fire regimes, seasonal and inter-annual variability, and future trends. Most wildfires are up to tens of kilometers in size, while global climate models usually have horizontal resolutions of hundreds of kilometers. Therefore, downscaling is required to provide high-resolution climate information for fire management applications. The climate and fire communities have made great strides in developing and applying climate downscaling techniques....

Wildfire predictions provide useful information for fire management planning and implementation. Temperature and precipitation have been used as the primary meteorological predictors for wildfires in China. This study is to improve the prediction skills of long-range (monthly, seasonal, and annual) wildfires in China by identifying other important meteorological predictors. Provincial data during 1999–2020 were used to calculate the correlations between fire properties (fire count and burned area) and meteorological variables of maximum temperature, precipitation, relative...

The fire plume height (smoke injection height) is an important parameter for calculating the transport and lifetime of smoke particles, which can significantly affect regional and global air quality and atmospheric radiation budget. To develop an observation-based global fire plume-rise data set, a modified one-dimensional plume-rise model was used with observation-based fire size and Maximum Fire Radiative Power (MFRP) data, which are derived from satellite fire hotspot measurements. The resulting data set captured well the observed plume height distribution derived from the Multiangle...