Investigating Antimicrobial Characteristics/Advantages of Australian Wood Species for Use in Food Packaging - A Feasibility Study

The antimicrobial characteristics of Australian commercial timber species were studied using a direct screening method and two different microorganisms. The effectiveness of timber samples was compared with plastic and paper samples during an incubation period of 24 h at 37 °C. The initial data with E. coli and S. aureus showed no difference in performance between the plastic and paper samples and the softwood samples tested. Hardwood samples, however, showed an inhibition zone when tested with S. Aureus. The data showed similar trends of inhibition zones developed for sterilised and non-sterilised samples of spotted gum and shining gum species. The observed data showed promising antimicrobial characteristics for both veneer and solid samples of hardwood species. Further studies investigating the type of extractives, their role in antimicrobial characteristics and differences in the type of surface exposed to the microbial contamination from the point of view of timber’s anatomical properties are proposed

Investigating the effects of moisture ingress on the performance and service life of Australian mass timber panels-characterization outcomes

Composite timber systems made of timber and massive wood products used in construction are susceptible to moisture fluctuations during transport, construction, and post-construction. The wetting dynamics, both ingress and egress, of Australian timber species and mass panels exposed to Australian climate conditions have not been extensively explored. Understanding moisture movement in timber is crucial for predicting the design life of timber products and developing decay modelling protocols. An experimental testing has been conducted in detail to comprehend water movement and moisture gradients in massive wood-based composites. The testing results presented in this paper include the density, porosity, gas, and liquid permeability of three Australian timber species (radiata pine, southern pine and shining gum). The experiments have been designed to explore the hygroscopic properties of timber species in different directions, including face, edge and end and of CLT (2P and 3P) and LVL sections. The porosity values for the three tested species were 56% ± 5, 57% ± 3 and 42% ± 8 for radiata pine, southern pine and shining gum respectively. The experimental results presented in this paper showed that CLT samples made from radiata pine with edge gap (3P) had higher porosity and permeability values than solid radiata sample sections. The CLT 2P sections had lower porosity values than the solid radiata pine samples. The porosity values determined for LVL (made from pine) samples (51% ± 3) were slightly lower than southern pine samples tested. The outcomes of this project will facilitate the prediction of product response to moisture and enable the development of maintenance protocols and remedial solutions for the industry to minimize the potential impacts of moisture penetration in mass timber products in the future. © 2023 13th World Conference on Timber Engineering

A Review of Traceability Systems in the Timber Industry

Wood, as a most important renewable and sustainable material source, has been widely used in many fields and our daily life for thousands of years. It constructs a bridge between tradition and modernity. During the manufacturing process, new materials, new connections, and new adhesives, as well as better logistics, will influence the wooden products quality, manufacturing, and transfer efficiency. In conclusion, they will influence the whole wood industry. The cascade utilization of wood in different wooden unit size scales, including macro, micro, even nanoscale. It can also be combined with various polymer systems to obtain composites with incredible performances. The aim of this book is to present the conventional, present and future advanced functional wooden composites, from traditional wood timber, to currently popular wood-based panels, wood-bioenergy, wood-carbon stock, wood-biodiversity of nature value, including light-weight wooden materials, use of alternative fast-growing species/recycled wood, a new adapted process to hardwoods and softwood, and many others. In addition, the most recent research achievements of super wood products with different functionality using advanced and novel techniques in high added value fields will also be covered

Effect of Alternate Drying Techniques on Cross-Laminated Timber after Exposure to Free-Water Wetting

Cross-laminated timber (CLT) panels are commonly used in mass-timber multistorey constructions due to their prefabrication, construction flexibility, environmental credentials and weight-to-strength ratio advantages compared to competing building materials. However, the long-term durability and service life of these mass timber panels require further understanding of their performance when exposed to free water. Wetting and drying trials were conducted by exposing Radiata pine (Pinus radiata) CLT sections to either free water (pooling on a single surface) or submerged water (all directions exposed) saturation, followed by either ambient or fan drying. The panels exposed to water pooling only reached MC above the FSP up to 40 mm of the panel depth. For submerged panels, the MC reached values above the fibre saturation point (FSP) at depths of 30 to 40 mm penetration on both panel faces. When comparing the ambient and fan-drying panel sections over the same time period, a less uniform MC profile was observed for the ambient drying, whereas the fan-dried panels fell below the FSP faster and with a more consistent MC profile. A complementary study was conducted on a standalone 3.0 × 3.0 m CLT room, where the room was wetted during a simulated pipe burst event. The moisture monitoring of wall and floor panels during fan drying of the room showed that an MC reduction from an excess of 40% to below 20% could be reached in less than 96 h for the panels’ surface; however, the middle sections of the panels dried slower than the surface sections. The CLT structure fan drying required a longer drying time than the CLT sections tested due to the closed sections (overlaps and connected faces) and a lower rate of airflow. The study of drying CLT sections highlighted the product reaching and maintaining MC higher than FSP points and the need for further drying applied to minimise long-term decay development. Further study is recommended to investigate the effects of closed sections (connected faces) and the duration of drying needed for semi-finished and finished buildings

Effect of Alternate Drying Techniques on Cross-Laminated Timber after Exposure to Free-Water Wetting

Cross-laminated timber (CLT) panels are commonly used in mass-timber multistorey constructions due to their prefabrication, construction flexibility, environmental credentials and weight-to-strength ratio advantages compared to competing building materials. However, the long-term durability and service life of these mass timber panels require further understanding of their performance when exposed to free water. Wetting and drying trials were conducted by exposing Radiata pine (Pinus radiata) CLT sections to either free water (pooling on a single surface) or submerged water (all directions exposed) saturation, followed by either ambient or fan drying. The panels exposed to water pooling only reached MC above the FSP up to 40 mm of the panel depth. For submerged panels, the MC reached values above the fibre saturation point (FSP) at depths of 30 to 40 mm penetration on both panel faces. When comparing the ambient and fan-drying panel sections over the same time period, a less uniform MC profile was observed for the ambient drying, whereas the fan-dried panels fell below the FSP faster and with a more consistent MC profile. A complementary study was conducted on a standalone 3.0 × 3.0 m CLT room, where the room was wetted during a simulated pipe burst event. The moisture monitoring of wall and floor panels during fan drying of the room showed that an MC reduction from an excess of 40% to below 20% could be reached in less than 96 h for the panels’ surface; however, the middle sections of the panels dried slower than the surface sections. The CLT structure fan drying required a longer drying time than the CLT sections tested due to the closed sections (overlaps and connected faces) and a lower rate of airflow. The study of drying CLT sections highlighted the product reaching and maintaining MC higher than FSP points and the need for further drying applied to minimise long-term decay development. Further study is recommended to investigate the effects of closed sections (connected faces) and the duration of drying needed for semi-finished and finished buildings

Validating moisture-safe energy efficient CLT assemblies in hot and humid climates using experimental testing

Climate specific cross-laminated timber (CLT) construction detailing to manage moisture risks in subtropical and tropical regions of Australia is validated through experimental testing, statistical analysis, and computational hygrothermal modelling. Three projects in Australia are monitored: a CLT micro-unit built in a subtropical climate, a small CLT structure assembled inside a controlled double climatic chamber simulating a tropical environment, and an existing residential building located in a tropical climate. Several parameters are altered in the experiment design to understand the most reliable assemblies for CLT buildings in hot and humid climates that can sufficiently control the moisture risks. The findings suggest that the hygrothermal modelling guidance from ASHRAE 160 pertaining to construction unprotected from stormwater accurately represents CLT assemblies in hot and humid climates. The importance of adhering weather resistant membranes (WRB) to both the external face and edge grains of the CLT panels is revealed. In tropical climates, the positioning of internal insulation and WRB with increased vapour resistance are also shown to be beneficial, while ventilated cavities and drainage layers behind the cladding is critical for rain protection

Cardioprotective Effects of Coenzyme Q10 Supplementation on Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background: We assessed the potential efficacy of Coenzyme Q10 (CoQ10) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Methods: Seventy STEMI patients who presented ≤12 hours after the onset of symptoms and were scheduled for PPCI were randomly assigned to the standard treatments plus CoQ10 or placebo. In the intervention group, CoQ10, as an oral capsule at a dose of 400 mg, was loaded immediately before PPCI and continued at 200 mg twice daily for 28 days. The control group received a matching placebo, similarly. The study endpoints were the proportion of patients with complete myocardial reperfusion, defined as thrombolysis in myocardial infarction (TIMI) flow and myocardial blush grade (MBG) 3 at the end of PPCI, the proportion of patients with complete ST-segment elevation resolution (≥70%) assessed 60 minutes after PPCI, the plasma levels of creatine kinase myocardial band isoenzyme (CK-MB) and troponin I (TnI) at 12, 24, 48, and 72 hours after PPCI, and left ventricular ejection fraction (LVEF) at day 28. Results: The study groups were comparable regarding baseline clinical and procedural characteristics. The proportion of patients with TIMI flow grade 3, MBG 3, and complete ST resolution after completion of PPCI was similar between the groups. Whereas at all-time points after PPCI (12, 24, 48, and 72 hours), the plasma levels of CK-MB and TnI were significantly lower in the CoQ10 group than in the control group. Further, at day 28, CoQ10-treated patients exhibited better LVEF than placebo-treated patients, and the proportion of patients with LVEF less than 50% was lower in the intervention group than in the control group. Conclusion: Our study provided evidence that CoQ10 supplementation might reduce myocardial ischemia-reperfusion injury after PPCI and help to preserve left ventricular function. However, further studies are required to validate these results

Mechanical behaviours of pumpkin peel under compression test

Mechanical damages such as bruising, collision and impact during food processing stages diminish quality and quantity of productions as well as efficiency of operations. Studying mechanical characteristics of food materials will help to enhance current industrial practices. Mechanical properties of fruits and vegetables describe how these materials behave under loading in real industrial operations. Optimizing and designing more efficient equipments require accurate and precise information of tissue behaviours. FE modelling of food industrial processes is an effective method of studying interrelation of variables during mechanical operation. In this study, empirical investigation has been done on mechanical properties of pumpkin peel. The test was a part of FE modelling and simulation of mechanical peeling stage of tough skinned vegetables. The compression test has been conducted on Jap variety of pumpkin. Additionally, stress strain curve, bio-yield and toughness of pumpkin skin have been calculated. The required energy for reaching bio-yield point was 493.75, 507.71 and 451.71 N.mm for 1.25, 10 and 20 mm/min loading speed respectively. Average value of force in bio-yield point for pumpkin peel was 310 N

Study of tissue damage during mechanical peeling of tough skinned vegetables

Peeling is an essential phase of post harvesting and processing industry; however the undesirable losses and waste rate that occur during peeling stage are always the main concern of food processing sector. There are three methods of peeling fruits and vegetables including mechanical, chemical and thermal, depending on the class and type of fruit. By comparison, the mechanical method is the most preferred; this method keeps edible portions of produce fresh and creates less damage. Obviously reducing material losses and increasing the quality of the process has a direct effect on the whole efficiency of food processing industry which needs more study on technological aspects of this industrial segment. In order to enhance the effectiveness of food industrial practices it is essential to have a clear understanding of material properties and behaviour of tissues under industrial processes. This paper presents the scheme of research that seeks to examine tissue damage of tough skinned vegetables under mechanical peeling process by developing a novel FE model of the process using explicit dynamic finite element analysis approach. In the proposed study a nonlinear model which will be capable of simulating the peeling process specifically, will be developed. It is expected that unavailable information such as cutting force, maximum shearing force, shear strength, tensile strength and rupture stress will be quantified using the new FEA model. The outcomes will be used to optimize and improve the current mechanical peeling methods of this class of vegetables and thereby enhance the overall effectiveness of processing operations. Presented paper aims to review available literature and previous works have been done in this area of research and identify current gap in modelling and simulation of food processes