The Change of Ultrasonic Transmission Velocity by Wood Decay

This study investigated the effect of phenol-formaldehyde (PF) resin treatment on the weathering stability and biological durability of birch plywood. Silver birch (Betula pendula) veneers were vacuum-pressure impregnated with four different PF resins with average molecular weights (Mw) of 292 (resin A), 528 (resin B), 703 (resin C), and 884 g/mol (resin D). The aging properties of PF resin modified birch plywood were analyzed using artificial weathering with ultraviolet (UV) light, UV and water spray, and weathering under outdoor conditions. The same combinations of PF-treated plywood specimens were then tested in soil-bed tests to determine their resistance against soft-rot wood decay. It was not possible to compare weathering processes under artificial conditions to processes under outdoor conditions. However, the weathering stability of birch plywood treated with PF resins A, B, and C, scored better than plywood treated with commercial resin D (regardless of solid content concentration [%]). Results from unsterile soil bed tests showed improvements in resistance to soft-rot wood decay compared to untreated plywood and solid wood. Mass loss [%] was lowest for birch plywood specimens treated with resin of highest solid content concentration (resin D, 20%). Provisional durability ratings delivered durability class (DC) ratings of 2–3, considerably improved over untreated solid wood and untreated birch plywood (DC 5).

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Evaluation of Moisture and Decay Models for a New Design Framework for Decay Prediction of Wood

Forests ◽

10.3390/f12060721 ◽

2021 ◽

Vol 12 (6) ◽

pp. 721

Author(s):

Jonas Niklewski ◽

Philip Bester van Niekerk ◽

Christian Brischke ◽

Eva Frühwald Hansson

Keyword(s):

Service Life ◽

Wood Decay ◽

Element Model ◽

Digital Design ◽

Design Guideline ◽

Digital Performance ◽

Detail Design ◽

Non Linear ◽

Service Life Design ◽

Life Design

Performance-based, service-life design of wood has been the focus of much research in recent decades. Previous works have been synthesized in various factorized design frameworks presented in the form of technical reports. Factorization does not consider the non-linear dependency between decay-influencing effects, such as between detail design and climate variables. The CLICKdesign project is a joint European effort targeting digital, performance-based specification for service-life design (SLD) of wood. This study evaluates the feasibility of using a semi-empirical moisture model (SMM) as a basis for a digital SLD framework. The performance of the SMM is assessed by comparison against a finite element model (FEM). In addition, two different wood decay models (a logistic, LM, and simplified logistic model (SLM)) are compared. While discrepancies between the SMM and FEM were detected particularly at high wood moisture content, the overall performance of the SMM was deemed sufficient for the application. The main source of uncertainty instead stems from the choice of wood decay model. Based on the results, a new method based on pre-calculated time series, empirical equations, and interpolation is proposed for predicting the service life of wood. The method is fast and simple yet able to deal with non-linear effects between weather variables and the design of details. As such, it can easily be implemented as part of a digital design guideline to provide decision support for architects and engineers, with less uncertainty than existing factorized guidelines.

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Degradation of shear performance of screwed joints caused by wood decay

Journal of Wood Science ◽

10.1186/s10086-020-01889-w ◽

2020 ◽

Vol 66 (1) ◽

Cited By ~ 1

Author(s):

Rintaro Ueda ◽

Kei Sawata ◽

Ryuya Takanashi ◽

Yoshihisa Sasaki ◽

Takanobu Sasaki

Keyword(s):

Wood Decay ◽

Shear Performance

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Characterization of the decay process of Scots pine caused by Coniophora puteana using NMR and MRI

Holzforschung ◽

10.1515/hf-2019-0246 ◽

2020 ◽

Vol 74 (11) ◽

pp. 1021-1032 ◽

Cited By ~ 2

Author(s):

Sami Hiltunen ◽

Arttu Mankinen ◽

Muhammad Asadullah Javed ◽

Susanna Ahola ◽

Martti Venäläinen ◽

...

Keyword(s):

Magnetic Resonance ◽

Scots Pine ◽

Structural Changes ◽

Free Water ◽

Wood Decay ◽

Active Regions ◽

Dry Mass ◽

Decay Process ◽

Coniophora Puteana ◽

Magnetic Resonance Imaging Mri

AbstractWood decay is an economically significant process, as it is one of the major causes of wood deterioration in buildings. In this study, the decay process of Scots pine (Pinus sylvestris) samples caused by cellar fungus (Coniophora puteana) was followed by nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) methods. Altogether, 30 wood sample pieces were exposed to fungus for 10 weeks. Based on the decrease of the dry mass, the samples were categorized into three classes: decomposed (mass decrease 50–70%), slightly decomposed (10–50%), and nondecomposed (<10%). MRI made it possible to identify the active regions of fungus inside the wood samples based on the signal of free water brought by the fungus and arisen from the decomposition of wood carbohydrates. MRI implies that free water is not only created by the decay process, but fungal hyphae also transports a significant amount of water into the sample. Two-dimensional 1H T1-T2 relaxation correlation NMR measurements provided detailed information about the changes in the microstructure of wood due to fungal decomposition. Overall, this study paves the way for noninvasive NMR and MRI detection of fungal decay at early stages as well as the related structural changes.

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Growth inhibition of wood-decay fungi by lignin-related aromatic compounds

European Journal of Wood and Wood Products ◽

10.1007/s00107-021-01689-z ◽

2021 ◽

Author(s):

Cédric Cabral Almada ◽

Mathilde Montibus ◽

Frédérique Ham-Pichavant ◽

Sandra Tapin-Lingua ◽

Gilles Labat ◽

...

Keyword(s):

Growth Inhibition ◽

Aromatic Compounds ◽

Wood Decay ◽

Decay Fungi ◽

Wood Decay Fungi

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An Italian Research Culture Collection of Wood Decay Fungi

Diversity ◽

10.3390/d12020058 ◽

2020 ◽

Vol 12 (2) ◽

pp. 58 ◽

Cited By ~ 3

Author(s):

Carolina Elena Girometta ◽

Annarosa Bernicchia ◽

Rebecca Michela Baiguera ◽

Francesco Bracco ◽

Simone Buratti ◽

...

Keyword(s):

Central Italy ◽

Wood Decay ◽

Mediterranean Area ◽

Culture Collection ◽

White Rot ◽

Temperate Climate ◽

Research Culture ◽

Decay Fungi ◽

Mn Peroxidase ◽

The Mediterranean

One of the main aims of the University of Pavia mycology laboratory was to collect wood decay fungal (WDF) strains in order to deepen taxonomic studies, species distribution, officinal properties or to investigate potential applications such as biocomposite material production based on fungi. The Italian Alps, Apennines and wood plains were investigated to collect Basidiomycota basidiomata from living or dead trees. The purpose of this study was to investigate the wood decay strains of the Mediterranean area, selecting sampling sites in North and Central Italy, including forests near the Ligurian and Adriatic seas, or near the Lombardy lakes. The isolation of mycelia in pure culture was performed according to the current methodology and the identity of the strains was confirmed by molecular analyses. The strains are maintained in the Research Culture Collection MicUNIPV of Pavia University (Italy). Among the 500 WDF strains in the collection, the most interesting isolates from the Mediterranean area are: Dichomitus squalens (basidioma collected from Pinus pinea), Hericium erinaceus (medicinal mushroom), Inocutis tamaricis (white-rot agent on Tamarix trees), Perenniporia meridionalis (wood degrader through Mn peroxidase) and P. ochroleuca. In addition, strains of species related to the Mediterranean climate (e.g., Fomitiporia mediterranea and Cellulariella warnieri) were obtained from sites with a continental-temperate climate.

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Detecting Heterobasidion irregulare in Minnesota and Assessment of Indigenous Fungi on Pines

Forests ◽

10.3390/f12010057 ◽

2021 ◽

Vol 12 (1) ◽

pp. 57

Author(s):

Eric Otto ◽

Benjamin Held ◽

Samuel Redford ◽

Robert A. Blanchette

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Wood Decay ◽

Positive Control ◽

Red Pine ◽

Pcr Assay ◽

Nested Polymerase Chain Reaction ◽

Decay Fungi ◽

Field Surveys ◽

Heterobasidion Irregulare

Heterobasidion irregulare is one of the most problematic forest pathogens in the northern hemisphere, but has only been found relatively recently in the north central United States. Discovered in Wisconsin in 1993, but probably established sometime before that, it quickly spread throughout the state. In November 2014, it was found in southeastern Minnesota. Field surveys were then conducted throughout Minnesota with the focus in the southeast near the initial discovery. To find additional infection sites, surveys were conducted with accompanying aerial imagery of red pine (Pinus resinosa Aiton) stands that were previously thinned. Samples were collected from selected sites with dead and dying trees as well as samples from stumps in recently thinned pine stands. These samples were processed first with a nested polymerase chain reaction (PCR) protocol, which was replaced by a real-time PCR assay after its development. No samples tested positive for H. irregulare using these methods and no cultures from isolations were obtained outside the original infection area. Other indigenous fungi were also identified. The majority were wood decay fungi in the Basidiomycota. A spore collection study was also conducted after field surveys. Automated rotary arm spore collectors were used and assayed with an ITS TaqMan real-time PCR assay. Collectors were placed strategically in different areas of Minnesota. A positive control was used in an infected red pine plantation in Wisconsin and this location had the highest number of spores trapped, with 63,776 over a week period. Spores of H. irregulare were detected at several sites in Minnesota, with the highest spore total observed in traps at 413 over a week period. All other locations sampled also had some spores collected except Itasca State Park located in northwestern Minnesota. The weekly deposition of spores ranged from 0 to 1.26 m−2 h−1. Low spore levels occurring in Minnesota indicate that some spores are present, but they are currently being detected in amounts that may not be sufficient for colonization to be successful.

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