Your search resulted in 87 documents. Displaying 25 entries per page.
In vitro antifungal activity of chilli against wood degrading fungi
2006 - IRG/WP 06-10572
The efficacy of chilli juice and/or chilli extract oleoresin as antisapstain agents was evaluated against two common sapstain fungi, Sphaeropsis sapinea and Leptographium procerum. Possible synergy between chilli juice and Lactobacillus casei as antisapstain agents was also assessed.
Both the chilli juice and the oleoresin showed moderate antifungal activity. No growth of the test fungi was obse...
T Singh, C Chittenden, D Vesentini
The effect of chitosan on the growth and physiology of two wood inhabiting fungi
2006 - IRG/WP 06-10590
The effect of chitosan on the wood inhabiting fungi Sphaeropsis sapinea and Trichoderma harzianum was evaluated at cellular level. Increasing concentrations of chitosan caused an increase in the amount of peroxide in cultures of S. sapinea, which was accompanied by a simultaneous decrease in superoxide. The same effect was not observed in T. harzianum. The growth of both fungi was inhibited when h...
D Vesentini, T Singh
Quantification of methylene bis thiocyanate in wood and its effect on a sapstain fungus Ophiostoma floccosum
2006 - IRG/WP 06-10591
The mobility and concentrations of MBT at different depths of wood billets (200 mm long, 40 mm in diameter) were determined using NMR spectroscopy and ICP-ASE, and then correlated the effect of wood MBT concentrations on growth of O. floccosum in a bioassay using stereomicroscopy and confocal laser scanning microscopy (CLSM).
The 13C NMR spectra showed the presence or absence of MBT in wood but w...
T Singh
Effect of chitosan on the morphology and ultrastructure of two wood inhabiting fungi
2007 - IRG/WP 07-10606
An investigation was undertaken to compare the antifungal effects caused by chitosan against two selected wood degrading fungi Sphaeropsis sapinea and Trichoderma harzianum on their growth, morphological and ultra-structural characteristics, using differential interference microscopy, epifluorescence microscopy and transmission electron microscopy.
The effect of chitosan on fungal morphology was ...
T Singh, A P Singh, G Daniel
Efficacy of chitosan in combination with GRAS (Generally Recognised As Safe) compounds as a potential wood preservative
2007 - IRG/WP 07-30414
In vitro studies were undertaken to evaluate the synergy between chitosan and selected GRAS (Generally Recognised As Safe) compounds against two sapstain fungi Sphaeropsis sapinea and Leptographium procerum. Bioassays performed on nutrient medium suggested that some of the GRAS compounds tested including sodium benzoate, potassium sorbate and ascorbic acid had a synergistic effect when combined w...
C Chittenden, K Thämelt, T Singh
In vitro evaluation of an integrated approach using Trichoderma harzianum and chitosan for the control of sapstain
2008 - IRG/WP 08-10659
In vitro assays were undertaken to evaluate the control of two sapstain fungi, Leptographium procerum and Sphaeropsis sapinea by a combination of chitosan or chitosan oligomer (CODP-14) and a naturally mutated strain of Trichoderma harzianum. Spore germination and hyphal growth of the test fungi were assessed on media amended with chitosan or chitosan oligomer with and without T. harzianum using ...
C Chittenden, T Singh
Antifungal activity of essential oils against common wood degrading/decaying fungi
2008 - IRG/WP 08-30465
Despite the wide use of essential oils in pharmaceutical and food industry as antimicrobial agents, their use as wood preservatives has not been fully explored. In this study, 12 essential oils were screened in nutrient medium for their antifungal activity against 8 common mould, sapstain or decay fungi. Subsequently, one essential oil, eugenol was evaluated for decay resistance in an agar/wood ...
T Singh, C Chittenden
Discovering anti-fungal agents in New Zealand native plants for use in wood protection
2009 - IRG/WP 09-10692
Extracts from Hinau (Elaeocarpus dentatus) leaves were tested in the laboratory for antifungal activity. In addition, the anatomical structure of the leaf was also examined by a combination of light and scanning electron microscopy. Chemical characterisation of the extracts and investigation into potential use of its components for wood protection is underway. A combination of light microscopy (...
C Rickard, T Singh, A Singh, R Newman
A rapid microscale assay for determining growth of wood inhabiting fungi against Lactobacillus metabolites
2009 - IRG/WP 09-20412
Lactobacillus sp. are well known for their ability to produce secondary metabolites with potent inhibitory activity against a wide range of bacterial species and there is increasing evidence to support their antifungal activity. These metabolites are often screened in laboratories using microscale 96-well plate optical density assays. The objective of this study was to develop an optical density a...
D O’Callahan, T Singh, I McDonald
Natural compounds: A review of their use for wood protection
2010 - IRG/WP 10-30545
A lot of research in the field of wood protection has focused on natural compounds but very few of these have been implemented by industry. This review is an attempt to bring together information from selected area of work:
- A brief review of the work done on natural products as organic biocides for wood protection.
- Table containing information on natural products, their use as organic biocid...
T Singh, A P Singh
Isolation and evaluation of Lactobacillus brevis from chilli waste for potential use as a wood preservative
2011 - IRG/WP 11-10749
Lactic acid bacteria were isolated from chilli waste and evaluated for their ability to arrest wood rotting basidiomycetes. In previous work a quick screening method using 96 well plates and measuring absorbance to determine fungal growth was developed specifically to investigate the efficacy of isolated bacteria against wood decay fungi. Using this method, one bacterium (isolate C11) was identif...
D O’Callahan, T Singh, I R McDonald
Characterisation and evaluation of various chitosan oligomers, and decay resistance
2011 - IRG/WP 11-30562
Chitosan, a polymer of D-glucosamine, is known for its antimicrobial activity. However, the physicochemical properties of chitosan depend upon three principal factors, i.e. source of raw material, molecular weight and degree of deacetylation. Here, we report synthesis and characterization of chitosan oligomers prepared by deaminative depolymerization of chitosan (s) obtained from Sigma Aldrich and...
I Hussain, C Chittenden, T Singh
Novel microscopic approaches to visualise chitosan within impregnated wood
2012 - IRG/WP 12-20485
Chitosan, a deacetylated product of an abundant naturally occurring biopolymer chitin, has been used in a range of applications, particularly in food and health areas, as an antimicrobial agent. In the work reported here Pinus radiata wood was impregnated with chitosan as an environmentally compatible organic biocide. It is important to understand micro-distribution of bioprotectants in impregnate...
A Singh, T Singh
Accelerated H3 above-ground decay testing
2013 - IRG/WP 13-20520
An above-ground H3 fungal field trial was installed at two sites in Australia and one in New Zealand, as well as in two Accelerated Field Simulators. The aim was to find a method that would shorten the time required for evaluating new preservatives and protection systems. One-quarter H3 retentions were installed, as first results suitable for registration occur when these reach 70% soundness. Twel...
L J Cookson, D Page, T Singh
The development of accelerated test systems to evaluate the durability of framing timber
2014 - IRG /WP 14-20547
Various accelerated decay resistance trials including small simulated wall units, samples exposed in enclosed tanks and ‘I’ samples in stacks have been explored and used to test the durability of treated and untreated radiata pine framing at Scion since 2001. These testing methods have been established to determine the effectiveness of commercial formulations in preventing decay in framing sub...
T Singh, D Page, J van der Waals
On-site remediation treatments for framing timber in leaky buildings
2014 - IRG/WP 14-20549
Weathertightness failures in New Zealand buildings due to the combined effects of cladding choices, design and construction faults and the use of untreated framing timber has led to the so called ‘leaky building syndrome’. The latest estimated cost of the leaky building crisis in New Zealand is about NZ$11 billion.
This research was conducted to provide a better understanding of the option...
T Singh, D Page, A Bennett
An update on durability of New Zealand grown timber
2015 - IRG/WP 15-10851
Classification and predication of in-service performances of naturally durable timber is much more difficult than preservative treated timber due to the variability of wood properties within and between trees of the same species and the variable nature of the hazard to which the timber will be exposed. A combination of field test and in-service testing has been used to classify the suitability of ...
D Page, T Singh
Remedial treatment of difficult to access timber in buildings
2015 - IRG/WP 15-40691
The quest to understand remedial treatment for timber framing begun following the ‘leaky building crisis’ in New Zealand which came to prominence in 2000. Several in-situ remedial treatment products are used in New Zealand. However, effectiveness of these treatments is still unclear particularly in situations where not all faces of the timber can be assessed. This research was conducted to det...
T Singh, I Simpson, D Page
Global survey on durability variation – on the effect of the reference species
2016 - IRG/WP 16-20573
Climate change due to anthropogenic emissions is the largest environmental challenge of our time. Forest-based value chains play an important role in reducing the accumulation of CO2 in the atmosphere. Maximizing the use of wood to tackle climate change requires improved understanding of the service life of timber products. This information can best be obtained from field testing and while there i...
R Stirling, G Alfredsen, C Brischke, I De Windt, L P Francis, E Frühwald Hansson, M Humar, J Jermer, M Klamer, M Kutnik, P Laks, I Le Bayon, S Metsä-Kortelainen, L Meyer-Veltrup, P I Morris, J Norton, T Singh, J Van Acker, J Van den Bulcke, T M Venås, H Viitanen, A H H Wong
CCA Treated Wood, Will It Last 100 Years?
2016 - IRG/WP 16-20575
Copper, chrome and arsenate (CCA) treated wood has a very successful history of use in New Zealand, for at least 60 years. In many parts of the world, CCA has been used for timber treatment since the mid-1930s. In this report, data are presented on the performance of CCA treated pine stakes and poles. Results from ground contact durability tests at Scion and other overseas test performance data su...
T Singh, D Page
The durability of manufactured structural building materials
2016 - IRG/WP 16-40718
The projected market potential for Engineered Wood Products such as CLT (cross laminated timber) is very positive however, potential prolonged rain leakage or moisture exposure during construction and in-service could pose considerable concern for its durability and reputation. This research was conducted to assess the decay resistance of CLT and OSB (oriented strand board) in an accelerated trial...
T Singh, D Page
Redwood Durability in NZ – Can pure culture laboratory tests predict outdoor service life
2017 - IRG/WP 17-20610
Coast Redwood (Sequoia sempervirens) is an alternative species in New Zealand to the large scale Pinus radiata plantations. Redwood is classified as moderately durable but its durability is extremely variable. In order to reduce this variability in future stock, understanding growth conditions, clone, and tree age effects are important however this involves many samples and is not suitable for ass...
D O’Callahan, C Chittenden, J van der Waals, D Meason, T Singh
Commercialisation of DMDHEU Modified Wood in Australasia
2017 - IRG/WP 17-40772
While there is an increasing volume of data for the impregnation and curing of timber using dimethylol dihydroxyethyleneurea (DMDHEU) on species such as Scots Pine, Beech, Slash Pine and Spotted gum, there is limited information available on the impact of the modification process on the performance of Pinus radiata (referred to hence forth as Radiata pine). The variability within material and spec...
B R Derham, T Singh, H Militz
A summary of history and use of timber bridges in New Zealand
2017 - IRG/WP 17-40801
Wooden bridges have been an important part of road and rail networks in New Zealand. While wooden structures have largely been replaced by concrete and steel on major arteries they still have a place where lightweight, easily assembled structures are needed. These timber bridges may also be a cheaper alternative to other materials in roads which carry relatively low traffic loads. In the last ten ...
D Page, T Singh
Above-ground testing methods – review of Rotorua, New Zealand test site results after ten years
2018 - RG/WP 18-20642
A series of seven different types of above ground durability tests were initially conducted over four years to determine which type of tests would give the fastest, most consistent results. Five types of test; ground proximity, two types of decking, flat panels and double layer, were reassessed after ten years. Exposure conditions varied between tests with ground proximity producing close to groun...
D Page, T Singh