Zealand Pine Research Articles

Crack initiation and propagation from a closing flaw with frictional contact in a natural quasi-brittle orthotropic solid

This work considers the frictional closing of a pre-existing flaw in a natural quasi-brittle orthotropic medium (wood) under compression. The effect of the flaw face friction at multiple orientations of the flaw, on the peak load-bearing capacity are investigated. The failure due to crack growth initiation from the periphery of the pre-existing flaw and its propagation was investigated experimentally and modelled numerically. The experimental investigation was carried out using New Zealand Pine wood with a pre-existing flaw under a quasi-static compression test. In the numerical investigation, an eXtended Finite Element Method (XFEM)-based cohesive zone model (CZM) is employed in the modelling of the local crack initiation and propagation. The onset of the crack initiation is modelled using a stress-based criterion and the progressive degradation due to crack propagation is traction-separation based damage evolution. The XFEM-based CZM captures the crack initiation and propagation consistent with the experimental results. The numerical results also show the influence of flaw face friction on the peak load bearing capacity as well as the local stress response.

A Study Protocol Investigating the Impact of the New Zealand Pine Bark Extract (Enzogenol®) on Sucrose Metabolism and Glycaemic Responses in Healthy Adults – A Randomised, Placebo-Controlled, Crossover Trial

A Study Protocol Investigating the Impact of the New Zealand Pine Bark Extract (Enzogenol®) on Sucrose Metabolism and Glycaemic Responses in Healthy Adults – A Randomised, Placebo-Controlled, Crossover Trial

AHP and GCA Combined Approach to Green Design Evaluation of Kindergarten Furniture

Kindergarten furniture is an important part of children’s furniture. However, in sharp contrast with the high level of concern about the color, shape, structure, and modularity of kindergarten furniture, the research on green design and green evaluation of kindergarten furniture has not been given due attention. Through understanding the concept and principles of green design, this paper presents an objective approach to evaluate the green design of kindergarten furniture. An evaluation method based on the analytic hierarchy process (AHP) integrating gray correlation analysis (GCA) for kindergarten furniture green design was proposed. By using the AHP to determine the green design elements of kindergarten furniture, five standard layer indicators were obtained in aspects of environmental friendliness of the materials, color, technological structure, size, and interestingness, as well as 11 criterion layer indicators: environmental friendliness of structural materials, environmental friendliness of adhesives, environmental friendliness of paint, stimulate creativity or enhance concentration, avoid the feelings of unsteadiness, structural stability, rounding the edges, comfortable to use, size adjustable, interesting decorative patterns, and modular. Afterward, GCA was used to evaluate the green design of five kindergarten furniture schemes and a comprehensive evaluation score was obtained. Taking the design scheme represented by five desk and chair sets in kindergarten as an example, the effectiveness of this method was verified, and the advantages and disadvantages of the five desk and chair sets were analyzed and compared. The results showed that the third desk and chair sets at kindergarten made of New Zealand pine ranks first in the comprehensive green evaluation indicators, followed by the fourth sets made of rubber and wood. After the green design evaluation, we studied the carbon footprint of five furniture products and analyzed their carbon emissions at the production stage, the packaging stage, the transportation stage, and the storage stage. The results show that the amount of carbon emission is generally consistent with the evaluation results of the green scheme, which verifies the effectiveness of the green design evaluation method. This study provides an effective and feasible reference for kindergarten furniture designers. Hence, a greener kindergarten furniture design is expected to improve the learning and living environment for kindergarten-age children.

Determination of fracture toughness and traction–separation relation in Mode I/II of a natural quasi-brittle orthotropic composite using multi-specimen approach

The fracture behavior of quasi-brittle naturally occurring composites is characterized by the presence of fracture process zone (FPZ), which is attributed by crack bridging and micro-cracking in wood. The FPZ limits the use of existing standards for fracture toughness. Also, the repeated loading–unloading approach using single specimen is difficult due to crack face interference. Further, the crack growth monitoring is difficult since the crack tip may be buried inside FPZ. So far, the compliance based beam method (CBBM) has offered a reasonable solution to these challenges. However, the CBBM is not an absolutely independent approach as it uses elastic constant and compliance determined from other experiments. Naturally occurring materials, like wood, exhibits large variations in its properties. Therefore, the use of parameters from multiple other experiments decreases the confidence in measured fracture toughness. Considering this, the present work evaluates the fracture toughness attributed by critical energy release rate of New Zealand Pine wood. Firstly, the research method follows a stand-alone multi-specimen approach to evaluate fracture toughness without any requirement for crack growth monitoring. Secondly, it experimentally establishes the traction–separation relation for both Mode I and II. This work has a general applicability to other natural quasi-brittle orthotropic solids like bone.

Load-Bearing Capacities and Pseudo-Ductility of Carbon Fiber-Reinforced New Zealand Pine Timber Beams

Building construction contributes a significant portion to the global consumption of energy and greenhouse gas (GHG) emissions, and decarbonization has become one of the main targets. This has turned much attention to renewable materials, particularly timber construction. Wood is a natural composite, and it causes challenges in its natural state due to its mechanical properties and functionality, which has constrained its use in construction. Laminating wood sections into glue-laminated (glulam) and cross-laminated timber (CLT) components overcomes limitations in dimensions and inconsistencies in its properties. We went beyond these technologies and explored the potential of combining timber of the radiata pine species with synthetic fibers, aiming for hybrid natural–synthetic composite beams. This research illustrated various reinforcement mechanisms and analyzed their structural properties. The results from the experiments showed that carbon fiber-reinforced timber composites have up to 49% additional increase in load-bearing capacity compared to unreinforced beams. An identical amount of strain required less stress, and the composite portrayed a metal-like ductility property, a characteristic referred to as pseudo-ductility. It reduces the material consumption in beams through a more efficient use of materials, particularly around compression areas before tensile rupture. The resulting composites are sustainable yet structurally capable, contributing to the reduction in CO2 emissions in timber construction systems.

The Inhibitory Effects of New Zealand Pine Bark (Enzogenol®) on α-Amylase, α-Glucosidase, and Dipeptidyl Peptidase-4 (DPP-4) Enzymes.

The New Zealand pine bark extract (Enzogenol®) has previously been shown to elicit acute hypoglycaemic effects in humans. The present study investigated the underlying mechanisms of Enzogenol® in reducing postprandial glucose in humans. The potential inhibitory action of Enzogenol® against digestive enzymes: α-amylase and α-glucosidase, and dipeptidyl peptidase-4 (DPP-4) enzyme was determined. Enzogenol® demonstrated the ability to inhibit all three enzymes: α-amylase enzyme activity (IC50 3.98 ± 0.11 mg/mL), α-glucosidase enzyme activity (IC50 13.02 ± 0.28 μg/mL), and DPP-4 enzyme activity (IC50 2.51 ± 0.04 mg/mL). The present findings indicate the potential for Enzogenol® to improve postprandial glycaemia by delaying carbohydrate digestion via the inhibition of digestive enzymes (α-amylase and α-glucosidase), and enhancing the incretin effect via inhibiting the dipeptidyl-peptidase-4 enzyme. The inhibitory actions of Enzogenol® on enzymes should therefore be further validated in humans for its potential use in type 2 diabetes mellitus prevention and management.

A strong multilayered transparent wood with natural wood color and texture

This experiment aims to study the performance of multilayered transparent wood (MLTW) under the condition of partial delignification, including the effect of lamination structure between layers and delignification process on the properties of MLTW. New Zealand pine (Pinus radiata D.Don) and Basswood (Tilia) were selected. The acid method was used to remove part lignin for preparing wood templates with natural wood color and texture, and then the polymer impregnated wood templates. During the lamination process, three wood templates were laminated by parallel direction (MLTW∥) or perpendicular direction (MLTW⊥) to prepare for MLTW. Under macro- and microtest, it can be seen that the laminate structure has a certain impact on the mechanical properties and light transmittance of MLTW, and MLTW can effectively reduce the anisotropy of single-layer one with the same thickness. MLTW is suitable for home decoration and structure materials and has broad application prospects.

Laboratory toxicity and large-scale commercial validation of the efficacy of ethanedinitrile, a potential alternative fumigant to methyl bromide, to disinfest New Zealand Pinus radiata export logs

We tested the efficacy of ethanedinitrile (EDN), a new fumigant considered as a potential methyl bromide (MB) replacement for the quarantine treatment of New Zealand pine, Pinus radiata D. Don, export logs. Firstly, toxicity trials were conducted in the laboratory with pine logs infested with the larvae, pupae, or adults of pine bark beetles, Hylurgus ligniperda and Hylastes ater, at 10 and 20 °C in 28-L chambers, to identify the most tolerant species and life stages. Then, logs infested with the most tolerant species and life stage were fumigated in 500-L laboratory chambers to determine whether the increase in the volume of the fumigated space and logs that will occur when scaling up from laboratory to commercial fumigations would affect EDN efficacy. Finally, confirmatory fumigation trials using commercial or semi-commercial sized log stacks, were conducted in a deforested commercial plantation area in Tokoroa, New Zealand, to demonstrate the efficacy of EDN in the field.Our results suggest EDN could be an effective alternative fumigant to MB for the phytosanitary treatment of logs exported from New Zealand. A phytosanitary fumigation schedule with EDN for P. radiata export logs that uses a concentration of 100 g/m3 for 20 h across a range of temperatures from 10 to 20 °C is recommended. Future efforts should focus on implementing the recommended schedule, under commercial practices, to provide quarantine security for export logs using EDN as a replacement for MB.

Study on the Properties of Partially Transparent Wood under Different Delignification Processes.

Two common tree species of Betula alnoides (Betula) and New Zealand pine (Pinups radiata D. Don) were selected as the raw materials to prepare for the partially transparent wood (TW) in this study. Although the sample is transparent in a broad sense, it has color and pattern, so it is not absolutely colorless and transparent, and is therefore called partially transparent. For ease of interpretation, the following “partially transparent wood” is referred to as “transparent wood (TW)”. The wood template (FW) was prepared by removing part of the lignin with the acid delignification method, and then the transparent wood was obtained by impregnating the wood template with a refractive-index-matched resin. The goal of this study is to achieve transparency of the wood (the light transmittance of the prepared transparent wood should be improved as much as possible) by exploring the partial delignification process of different tree species on the basis of retaining the aesthetics, texture and mechanical strength of the original wood. Therefore, in the process of removing partial lignin by the acid delignification method, the orthogonal test method was used to explore the better process conditions for the preparation of transparent wood. The tests of color difference, light transmittance, porosity, microstructure, chemical groups, mechanical strength were carried out on the wood templates and transparent wood under different experimental conditions. In addition, through the three major elements (lignin, cellulose, hemicellulose) test and orthogonal range analysis method, the influence of each process factor on the lignin removal of each tree species was obtained. It was finally obtained that the two tree species acquired the highest light transmittance at the experimental level 9 (process parameters: NaClO2 concentration 1 wt%, 90 °C, 1.5 h); and the transparent wood retained most of the color and texture of the original wood under partial delignification up to 4.84–11.07%, while the mechanical strength with 57.76% improved and light transmittance with 14.14% higher than these properties of the original wood at most. In addition, the wood template and resin have a good synergy effect from multifaceted analysis, which showed that this kind of transparent wood has the potential to become the functional decorative material.

An Acute, Placebo-Controlled, Single-Blind, Crossover, Dose-Response, Exploratory Study to Assess the Effects of New Zealand Pine Bark Extract (Enzogenol®) on Glycaemic Responses in Healthy Participants.

An acute, placebo-controlled, single-blind, crossover, dose-response, exploratory study was designed to investigate the hypoglycaemic effects of New Zealand pine bark extract (Enzogenol®). Twenty-five healthy participants categorised into having a monophasic or complex (biphasic or triphasic) glucose curve shape at the control visit consumed a placebo and Enzogenol® (50 and 400 mg) on three separate occasions before an oral glucose tolerance test (OGTT). In the monophasic group, 50 and 400 mg of Enzogenol® significantly reduced the mean glucose incremental area under the curve (iAUC) compared to control 241.3 ± 20.2 vs. 335.4 ± 34.0 mmol/L·min, p = 0.034 and 249.3 ± 25.4 vs. 353.6 ± 31.5 mmol/L·min, p = 0.012, respectively. The 400 mg dose further reduced the percentage increment of postprandial glucose (%PG) 31.4% ± 7.9% vs. 47.5% ± 8.6%, p = 0.010, glucose peak 7.9 ± 0.3 vs. 8.9 ± 0.3 mmol/L, p = 0.025 and 2h-OGTT postprandial glucose (2hPG) 6.1 ± 0.3 vs. 6.7 ± 0.3 mmol/L, p = 0.027. Glucose iAUC was not significantly different in the complex group, except for reductions in %PG 28.7% ± 8.2% vs. 43.4% ± 5.9%, p = 0.012 after 50 mg dose and 27.7% ± 5.4% vs. 47.3% ± 7.2%, p = 0.025 after 400 mg dose. The results suggest that Enzogenol® may have hypoglycaemic effects in healthy participants, especially those exhibiting monophasic shapes.

A study on the fire extinguishing characteristics of deep-seated fires using the scale model experiment

NFPA 18 is used as a standard for the performance evaluation of wetting agents used in fire fighting. The performance evaluation of the wetting agent involves three tests: a wood crib fire test, a deep-seated fire test, and a wood fiberboard penetration test. In this study, a scale model experimental device, which can evaluate both extinguishing performance and penetration performance at once, was prepared to evaluate the performance of a wetting agent in various types of porous materials. Then, this result was compared with the results of an NFPA 18 test to validate the result of the novel test. Three types of commercial fire-fighting solutions and water were used as extinguishing agents in the experiment. The experimental materials used in this performance evaluation were wood crib which is used in the existing class A fire test and wood flour from New Zealand pine trees which has 75% of the domestic market share in wood cribs. The discrimination of the study result used in this study to determine penetration and extinguishing performances was found to be equivalent to the results of the NFPA18 test. Moreover, the study established the validity of the scale model that could check on both penetration and extinguishing performance, permitting a more economical and efficient performance evaluation of wetting agents.

Effect of MonaVie Balanceœ on stress levels and mood state in moderately stressed subjects (647.22)

BACKGROUND: A variety of medicinal plants are used traditionally to reduce anxiety and induce relaxation. Modern herbal supplements, including Magnolia bark (Magnolia officinalis), Tongkat ali (Eurycoma longifolia), and Ashwagandha (Withania somnifera) have been shown to reduce both cortisol exposure and the perception of stress/anxiety, while improving weight loss in subjects with stress‐related eating. OBJECTIVE: We conducted a pilot study in 20 moderately stressed subjects to assess changes in psychological mood state following dietary supplementation for 4 weeks with a combination product (MonaVie BalanceTM) intended to reduce stress and improve well‐being. The product contains a blend of Magnolia bark, Phellodendron bark, Tongkat ali root, Ashwagandha leaf, Amla fruit, and New Zealand pine bark. METHODS: The 65‐question Profile of Mood States (POMS) survey and an abbreviated stress/vigor index were administered before and after 4 weeks of supplementation. RESULTS: Following 4 weeks of supplementation, improved scores were found for chronic stress index (‐23%), well‐being index (+23%), and psychological vigor (+70%). CONCLUSION: These preliminary results suggest that supplementation with MonaVie Balance reduces perceived stress while improving a variety of mood state parameters, suggesting an effective natural approach to the detrimental health effects of chronic stress.

Developing risk hypotheses and selecting species for assessing non-target impacts of GM trees with novel traits: The case of altered-lignin pine trees

A procedure is presented for developing environmental risk hypotheses associated with the deployment of forest trees genetically modified to have altered wood properties and for selecting non-target species to test these hypotheses. Altered-lignin Pinus radiata trees intended for use in New Zealand are used as a hypothetical case study to illustrate our approach. Firstly, environmental management goals (such as wood production, flood control or preservation of biodiversity) were identified and linked to the forest attributes they require. Necessary conditions for each attribute were listed and appropriate assessment endpoints for them developed. For example, biological control of pests may be one condition necessary for a forest to have healthy trees, and the diversity and abundance of natural enemy species in the forest could be an appropriate assessment endpoint for measuring this condition. A conceptual model describing the relationships between an altered-lignin GM pine tree and potentially affected invertebrates and micro-organisms in a plantation forest was used to develop a set of risk hypotheses describing how the GM trees might affect each assessment endpoint. Because purified lignin does not represent the properties it imparts to wood, maximum hazard dose tests with non-target organisms, as are used to inform toxin risk assessment, cannot be conducted. Alternative experiments, based on current knowledge of the responses of organisms to lignin, must be designed. A screening method was adapted and applied to a database of invertebrate species known to inhabit New Zealand pine forests to identify and prioritize non-target invertebrate species that could be used as experimental subjects for examining these hypotheses. The screening model and its application are presented, along with a set of recommendations for pre-release tests with GM pines and potentially affected invertebrates and micro-organisms.

Association of Entomopathogenic Fungi with Exotic Bark Beetles in New Zealand Pine Plantations

Hylastes ater and Hylurgus ligniperda are introduced pests of re-established Pinus radiata in New Zealand. Both species breed under the bark of stumps in recently harvested areas. Adult maturation feeding on pine seedlings planted in adjacent areas can significantly impact seedling growth, and in severe cases seedlings will die. Entomopathogenic fungi are important natural mortality factors in bark beetle populations, and Beauveria spp. are predominant. Here, we report on the isolation of other fungal species from H. ater in New Zealand. Based on morphological characteristics and sequencing data, two species, Metarhizium flavoviride var. pemphigi and Hirsutella guignardii, were recovered from H. ater. Both are new records for New Zealand and appear to be the first records of these species from bark beetles worldwide.

Colonization and use of pine wood versus native wood in New Zealand plantation forest streams: implications for riparian management

Abstract Riparian management is becomingly increasingly recognized as an important tool for reducing harvesting impacts on plantation forest streams. To provide information for a riparian management decision support system, this study investigated effects of riparian tree type (plantation Pinus radiata D. Don versus four native species) on the development of epixylic biofilms, and colonization and feeding by invertebrates on wood at two contrasting stream sites in the central North Island, New Zealand. Electron micrographs revealed a diverse microflora colonizing all wood types, which generally had similar ergosterol concentrations, microbial activity and algal biomass after 1–2 years immersion. Wood type (pine versus native) did not have a significant effect on densities of total invertebrates or dominant taxa. Percentage abundance of some dominant invertebrate groups differed between wood species, apparently in relation to surface complexity, but overall physical habitat differences appeared to override any effects of wood type on community composition. The mass of fine particulate material produced by larvae of the conoesucid caddis fly, Pycnocentria funerea McLachlan, differed significantly among wood species, but this was not related to whether the wood was from native trees or plantation pine. Overall, the results indicate that local variations in habitat heterogeneity and differences in wood surface texture were more important than wood type in influencing epixylic biofilm development, and utilization by invertebrates. Alien pine wood generally provided habitat conditions and trophic resources during initial decomposition that were within the range of variation of native wood species expected to colonize riparian planting set‐backs in northern New Zealand pine forests. Copyright © 2004 John Wiley & Sons, Ltd.

Computing maximum willingness to pay with Faustmann's formula: some special situations from New Zealand

Faustmann's theory of discounted cash flow analysis, developed using perpetually recurring before-tax cash flows facilitates the determination of the maximum willingness to pay (WTP) (i.e. economic) value of bare forestland and immature timber. He describes three valuation approaches: (1) compounding costs; (2) compounding/discounting annuities; and (3) discounting future cash flows. If non-recurring costs (or benefits) are incurred in any rotation or if the current stand is non-optimal with respect to future rotations, the discounting of future cash flows is the preferred approach. When after-tax cash flows are considered, four categories of tax treatment must be addressed: (1) immediately deductible expenditures; (2) capitalized expenditures which are deducted against future harvest revenue; (3) capitalized expenditures which are depreciated or amortized; and (4) non-deductible expenditures. Apart from the second case, either compounding costs or discounting future cash flows can be used to value a stand. However, discounting cash flows is the preferred approach when expenditures are capitalized and deducted against future harvest revenues. Illustrations of the consequences of the four categories of tax treatment are shown with respect to New Zealand pine plantations. Extension to the tax policies of other countries is straightforward.

Asthma and other respiratory symptoms in New Zealand pine processing sawmill workers.

To study respiratory symptoms in pine sawmill workers. A respiratory health questionnaire was administered to 772 pine sawmill workers and the association between symptoms and job-title-based exposure was studied. Asthma in exposed workers (18%, n = 704) was more common than in the general population (12.1%, n = 592; adjusted OR (95% CI): 1.6 (1.1-2.3)). Asthma was also more common in the low exposure group (15.6%, n = 294) and high exposure groups (high exposure to 'green dust'; 20.4%, n = 212 and high exposure to 'dry dust'; 18.8%, n = 198) than in the non-exposed workers (9.2%, n = 65). Adjusted odds ratios were 1.9 (0.7-4.9), 2.7 (0.9-7.6), and 2.1 (0.8-5.7), respectively. Adjusted odds ratios for symptoms of cough were 2.7 (1.2-6.5) for the low, 5.2 (2.1-13.0) for the high 'green dust' and 3.3 (1.4-7.9) for the high 'dry dust' exposure groups. Moreover, eye and nose irritations were significantly more prevalent in the high and low exposure groups. Working in pine sawmilling is associated with an increased prevalence of asthma and cough symptoms and eye and nose irritation.

Measuring woody debris in the small streams of New Zealand's pine plantations

To assess the impact of harvesting on woody debris volumes in streams, a method was required with sufficient precision to provide meaningful evaluation and comparison of pre‐ and post‐harvest levels of woody debris. Before harvest, woody debris volumes were measured in 24 first‐ to third‐order stream sites in New Zealand's mature pine plantations (22–34 years of age). An adaptation of the Van Wagner line intersect method was used to measure the small woody debris 1–9 cm in diameter (SWD). All large woody debris ≥10 cm in diameter (LWD) was measured for diameter and length. Woody debris volumes in the stream channel ranged from 2 to 345 m3ha‐1, averaging 112 m3 ha‐1 (±34, 95% confidence interval (CI)). Woody debris surface areas averaged 2883 m2 ha‐1 (±688), range 220–6769 m2 ha‐1. Most of the woody debris volume (87%) was composed of LWD. Sixty‐seven percent of the woody debris volume was located above the stream, the remainder was lying in‐stream or on the floodplain. Woody debris volumes in streams of mature pine plantations in New Zealand were similar to woody debris volumes in streams of temperate native forests in New Zealand and North America. These sites will be remeasured after harvest to identify any changes in woody debris characteristics.

Kraft Pulping of New Zealand Wood Species

Five New Zealand pine and three beech (Nothofagus) species were examined for kraft pulping, Each species of the pines and beeches was easily pulped and gave pulps in good yields and brightness. However, the red and hard beeches which contained large amount of extractives gave lower yields and brightness compared to the pulps from the same species of smaller diameter which contained lower extractive contents.The pine kraft pulps had similar bursting strength and tensile strength to those of Japanese pine, but had slightly lower tear strength.All strength properties of the pulps from the New Zealand beech species were in the lower grade than the Japanese mixed hard wood pulp.