Long-term moisture absorption and thickness swelling behaviour of recycled thermoplastics reinforced with Pinus radiata sawdust

2008 ◽  
Vol 142 (2) ◽  
pp. 190-198 ◽  
Author(s):  
Kamal B. Adhikary ◽  
Shusheng Pang ◽  
Mark P. Staiger
2019 ◽  
Vol 38 (19-20) ◽  
pp. 923-937 ◽  
Author(s):  
Tanusree Bera ◽  
Niharika Mohanta ◽  
Ved Prakash ◽  
Subhrajit Pradhan ◽  
Samir K Acharya

2016 ◽  
Vol 69 ◽  
pp. 64-67
Author(s):  
K. Mellow ◽  
P. Chettri ◽  
S. Kabir ◽  
R.L. McDougal ◽  
M.P. Cox ◽  
...  

Trichoderma cf atroviride is an endophytic soil fungus which has been the target of much research due to its plant growth promoting effects and use as a biocontrol agent. For specific bioactive strains of this species to be used with longlived forest trees such as Pinus radiata they must persist over the long term in the host root system. To investigate the persistence of specific T cf atroviride strains in the roots of P radiata unique regions were identified in the genomes of strains that were more than 997 identical by using next generation sequencing. Based on these unique regions probebased strainspecific quantitative PCR assays were developed. The assays can be used to test strain persistence in nursery and forestgrown seedlings inoculated with mixtures of T cf atroviride strains as well as in laboratory experiments to determine the effect of these strains on plant metabolism and defence.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1829 ◽  
Author(s):  
Manuel Alejandro Pedreño-Rojas ◽  
María Jesús Morales-Conde ◽  
Paloma Rubio-de-Hita ◽  
Filomena Pérez-Gálvez

Large amounts of wood waste are generated each year in the world. In an attempt to identify a good recovery option for those residues, wood waste from construction and demolition works were used as raw materials in gypsum plasters. However, wood is a biodegradable material which implies that the products or materials that contain it are susceptible to suffering an important deterioration, due to exposure in certain environments. For that reason, the aim of this work was to simulate the effects that, in the long term, the atmospheric exposure of wood waste–gypsum composites would have. To do that, the plasters were subjected to 5, 10, and 15 wetting–drying cycles in a climatic chamber. In this study, the density, flexural and compressive strength, and ultrasonic velocity of these composites were determined by the influence of the aging process on their mechanical properties. Furthermore, in order to detect changes on their internal structure, scanning electron microscopy tests (SEM) were used. The results showed that they were suitable to be used as indoor coverings of buildings. However, a treatment to reduce the moisture absorption of the wood waste must be studied if mixtures with high percentages of wood shavings (WS20) are used in wet rooms.


2008 ◽  
Vol 19 (2) ◽  
pp. 85-100 ◽  
Author(s):  
Huiquan Bi ◽  
Jack Simpson ◽  
Robert Eldridge ◽  
Steve Sullivan ◽  
Rong-wei Li ◽  
...  

2008 ◽  
Vol 35 (6) ◽  
pp. 448 ◽  
Author(s):  
Lai Fern Ow ◽  
David Whitehead ◽  
Adrian S. Walcroft ◽  
Matthew H. Turnbull

Pinus radiata L. were grown in climate-controlled cabinets under three night/day temperature treatments, and transferred between treatments to mimic changes in growth temperature. The objective was to determine the extent to which dark respiration and photosynthesis in pre-existing and new needles acclimate to changes in growth temperatures. We also assessed whether needle nitrogen influenced the potential for photosynthetic and respiratory acclimation, and further assessed if short-term (instantaneous, measured over a few hours) respiratory responses are accurate predictors of long-term (acclimated, achieved in days–weeks) responses of respiration to changing temperature. Results show that respiration displayed considerable potential for acclimation. Cold and warm transfers resulted in some acclimation of respiration in pre-existing needles, but full acclimation was displayed only in new needles formed at the new growth temperature. Short-term respiratory responses were poor predictors of the long-term response of respiration due to acclimation. There was no evidence that photosynthesis in pre-existing or new needles acclimated to changes in growth temperature. N status of leaves had little impact on the extent of acclimation. Collectively, our results indicate that there is little likelihood that respiration would be significantly stimulated in this species as night temperatures increase over the range of 10–20°C, but that inclusion of temperature acclimation of respiration would in fact lead to a shift in the balance between photosynthesis and respiration in favour of carbon uptake.


Author(s):  
Quang Nguyen ◽  
Jordan C. Roberts ◽  
Jeffrey C. Suhling ◽  
Richard C. Jaeger ◽  
Pradeep Lall

In this work, an investigation has been performed on hygrothermally induced die stresses in flip chip assemblies caused by moisture absorption by the underfill encapsulant. Silicon test chips were first applied to perform a variety of measurements of moisture and thermally induced die stresses in flip chip on laminate assemblies. The sample die stresses were first measured after underfill encapsulation and cure, and then subsequently after long term storage (10 years) at room temperature and ambient humidity. The assemblies were then exposed to and 85 °C and 85% RH high humidity harsh environment for various durations, and the die stresses were evaluated as a function of the exposure time. Finally, reversibility tests were conducted to see whether the effects of moisture uptake were permanent. After long term storage, the experimental measurements showed that the normal stresses in the flip chip die relaxed significantly, while the shear stresses exhibited only small variations. In addition, the 85/85 hygrothermal exposure had strong effects, generating tensile die normal stress changes of up to 30 MPa in the flip chip assemblies. Thus, the initial compressive die normal stresses due to flip chip assembly were found to relax significantly during the moisture exposure. Upon fully redrying, it was observed that the moisture-induced stress changes were fully recovered. The results of the experimental measurements were subsequently correlated with predictions from finite element numerical simulations. When performing moisture diffusion modeling, the conventional method is to use a thermal analogy based on the similarity of governing equations of heat transfer and moisture diffusion. However, this method has some drawbacks including giving incorrect results when dealing with time- and temperature-dependent problems or discontinuities in the moisture concentrations at material boundaries. In this study, we have used a new feature in ANSYS v14 to perform coupled multi-physics simulations of the moisture diffusion process without the aforementioned limitations. The simulation results were found to show strong correlations with experimental measurements.


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